Bug Summary

File:src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaDeclCXX.cpp
Warning:line 4005, column 8
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SemaDeclCXX.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model static -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/gnu/usr.bin/clang/libclangSema/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/gnu/usr.bin/clang/libclangSema/obj/../include/clang/Sema -I /usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/include -I /usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/llvm/include -I /usr/src/gnu/usr.bin/clang/libclangSema/../include -I /usr/src/gnu/usr.bin/clang/libclangSema/obj -I /usr/src/gnu/usr.bin/clang/libclangSema/obj/../include -D NDEBUG -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D LLVM_PREFIX="/usr" -internal-isystem /usr/include/c++/v1 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/usr/src/gnu/usr.bin/clang/libclangSema/obj -ferror-limit 19 -fvisibility-inlines-hidden -fwrapv -stack-protector 2 -fno-rtti -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c++ /usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaDeclCXX.cpp
1//===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements semantic analysis for C++ declarations.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/AST/ASTConsumer.h"
14#include "clang/AST/ASTContext.h"
15#include "clang/AST/ASTLambda.h"
16#include "clang/AST/ASTMutationListener.h"
17#include "clang/AST/CXXInheritance.h"
18#include "clang/AST/CharUnits.h"
19#include "clang/AST/ComparisonCategories.h"
20#include "clang/AST/EvaluatedExprVisitor.h"
21#include "clang/AST/ExprCXX.h"
22#include "clang/AST/RecordLayout.h"
23#include "clang/AST/RecursiveASTVisitor.h"
24#include "clang/AST/StmtVisitor.h"
25#include "clang/AST/TypeLoc.h"
26#include "clang/AST/TypeOrdering.h"
27#include "clang/Basic/AttributeCommonInfo.h"
28#include "clang/Basic/PartialDiagnostic.h"
29#include "clang/Basic/TargetInfo.h"
30#include "clang/Lex/LiteralSupport.h"
31#include "clang/Lex/Preprocessor.h"
32#include "clang/Sema/CXXFieldCollector.h"
33#include "clang/Sema/DeclSpec.h"
34#include "clang/Sema/Initialization.h"
35#include "clang/Sema/Lookup.h"
36#include "clang/Sema/ParsedTemplate.h"
37#include "clang/Sema/Scope.h"
38#include "clang/Sema/ScopeInfo.h"
39#include "clang/Sema/SemaInternal.h"
40#include "clang/Sema/Template.h"
41#include "llvm/ADT/ScopeExit.h"
42#include "llvm/ADT/SmallString.h"
43#include "llvm/ADT/STLExtras.h"
44#include "llvm/ADT/StringExtras.h"
45#include <map>
46#include <set>
47
48using namespace clang;
49
50//===----------------------------------------------------------------------===//
51// CheckDefaultArgumentVisitor
52//===----------------------------------------------------------------------===//
53
54namespace {
55/// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
56/// the default argument of a parameter to determine whether it
57/// contains any ill-formed subexpressions. For example, this will
58/// diagnose the use of local variables or parameters within the
59/// default argument expression.
60class CheckDefaultArgumentVisitor
61 : public ConstStmtVisitor<CheckDefaultArgumentVisitor, bool> {
62 Sema &S;
63 const Expr *DefaultArg;
64
65public:
66 CheckDefaultArgumentVisitor(Sema &S, const Expr *DefaultArg)
67 : S(S), DefaultArg(DefaultArg) {}
68
69 bool VisitExpr(const Expr *Node);
70 bool VisitDeclRefExpr(const DeclRefExpr *DRE);
71 bool VisitCXXThisExpr(const CXXThisExpr *ThisE);
72 bool VisitLambdaExpr(const LambdaExpr *Lambda);
73 bool VisitPseudoObjectExpr(const PseudoObjectExpr *POE);
74};
75
76/// VisitExpr - Visit all of the children of this expression.
77bool CheckDefaultArgumentVisitor::VisitExpr(const Expr *Node) {
78 bool IsInvalid = false;
79 for (const Stmt *SubStmt : Node->children())
80 IsInvalid |= Visit(SubStmt);
81 return IsInvalid;
82}
83
84/// VisitDeclRefExpr - Visit a reference to a declaration, to
85/// determine whether this declaration can be used in the default
86/// argument expression.
87bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(const DeclRefExpr *DRE) {
88 const NamedDecl *Decl = DRE->getDecl();
89 if (const auto *Param = dyn_cast<ParmVarDecl>(Decl)) {
90 // C++ [dcl.fct.default]p9:
91 // [...] parameters of a function shall not be used in default
92 // argument expressions, even if they are not evaluated. [...]
93 //
94 // C++17 [dcl.fct.default]p9 (by CWG 2082):
95 // [...] A parameter shall not appear as a potentially-evaluated
96 // expression in a default argument. [...]
97 //
98 if (DRE->isNonOdrUse() != NOUR_Unevaluated)
99 return S.Diag(DRE->getBeginLoc(),
100 diag::err_param_default_argument_references_param)
101 << Param->getDeclName() << DefaultArg->getSourceRange();
102 } else if (const auto *VDecl = dyn_cast<VarDecl>(Decl)) {
103 // C++ [dcl.fct.default]p7:
104 // Local variables shall not be used in default argument
105 // expressions.
106 //
107 // C++17 [dcl.fct.default]p7 (by CWG 2082):
108 // A local variable shall not appear as a potentially-evaluated
109 // expression in a default argument.
110 //
111 // C++20 [dcl.fct.default]p7 (DR as part of P0588R1, see also CWG 2346):
112 // Note: A local variable cannot be odr-used (6.3) in a default argument.
113 //
114 if (VDecl->isLocalVarDecl() && !DRE->isNonOdrUse())
115 return S.Diag(DRE->getBeginLoc(),
116 diag::err_param_default_argument_references_local)
117 << VDecl->getDeclName() << DefaultArg->getSourceRange();
118 }
119
120 return false;
121}
122
123/// VisitCXXThisExpr - Visit a C++ "this" expression.
124bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(const CXXThisExpr *ThisE) {
125 // C++ [dcl.fct.default]p8:
126 // The keyword this shall not be used in a default argument of a
127 // member function.
128 return S.Diag(ThisE->getBeginLoc(),
129 diag::err_param_default_argument_references_this)
130 << ThisE->getSourceRange();
131}
132
133bool CheckDefaultArgumentVisitor::VisitPseudoObjectExpr(
134 const PseudoObjectExpr *POE) {
135 bool Invalid = false;
136 for (const Expr *E : POE->semantics()) {
137 // Look through bindings.
138 if (const auto *OVE = dyn_cast<OpaqueValueExpr>(E)) {
139 E = OVE->getSourceExpr();
140 assert(E && "pseudo-object binding without source expression?")((void)0);
141 }
142
143 Invalid |= Visit(E);
144 }
145 return Invalid;
146}
147
148bool CheckDefaultArgumentVisitor::VisitLambdaExpr(const LambdaExpr *Lambda) {
149 // C++11 [expr.lambda.prim]p13:
150 // A lambda-expression appearing in a default argument shall not
151 // implicitly or explicitly capture any entity.
152 if (Lambda->capture_begin() == Lambda->capture_end())
153 return false;
154
155 return S.Diag(Lambda->getBeginLoc(), diag::err_lambda_capture_default_arg);
156}
157} // namespace
158
159void
160Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc,
161 const CXXMethodDecl *Method) {
162 // If we have an MSAny spec already, don't bother.
163 if (!Method || ComputedEST == EST_MSAny)
164 return;
165
166 const FunctionProtoType *Proto
167 = Method->getType()->getAs<FunctionProtoType>();
168 Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
169 if (!Proto)
170 return;
171
172 ExceptionSpecificationType EST = Proto->getExceptionSpecType();
173
174 // If we have a throw-all spec at this point, ignore the function.
175 if (ComputedEST == EST_None)
176 return;
177
178 if (EST == EST_None && Method->hasAttr<NoThrowAttr>())
179 EST = EST_BasicNoexcept;
180
181 switch (EST) {
182 case EST_Unparsed:
183 case EST_Uninstantiated:
184 case EST_Unevaluated:
185 llvm_unreachable("should not see unresolved exception specs here")__builtin_unreachable();
186
187 // If this function can throw any exceptions, make a note of that.
188 case EST_MSAny:
189 case EST_None:
190 // FIXME: Whichever we see last of MSAny and None determines our result.
191 // We should make a consistent, order-independent choice here.
192 ClearExceptions();
193 ComputedEST = EST;
194 return;
195 case EST_NoexceptFalse:
196 ClearExceptions();
197 ComputedEST = EST_None;
198 return;
199 // FIXME: If the call to this decl is using any of its default arguments, we
200 // need to search them for potentially-throwing calls.
201 // If this function has a basic noexcept, it doesn't affect the outcome.
202 case EST_BasicNoexcept:
203 case EST_NoexceptTrue:
204 case EST_NoThrow:
205 return;
206 // If we're still at noexcept(true) and there's a throw() callee,
207 // change to that specification.
208 case EST_DynamicNone:
209 if (ComputedEST == EST_BasicNoexcept)
210 ComputedEST = EST_DynamicNone;
211 return;
212 case EST_DependentNoexcept:
213 llvm_unreachable(__builtin_unreachable()
214 "should not generate implicit declarations for dependent cases")__builtin_unreachable();
215 case EST_Dynamic:
216 break;
217 }
218 assert(EST == EST_Dynamic && "EST case not considered earlier.")((void)0);
219 assert(ComputedEST != EST_None &&((void)0)
220 "Shouldn't collect exceptions when throw-all is guaranteed.")((void)0);
221 ComputedEST = EST_Dynamic;
222 // Record the exceptions in this function's exception specification.
223 for (const auto &E : Proto->exceptions())
224 if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second)
225 Exceptions.push_back(E);
226}
227
228void Sema::ImplicitExceptionSpecification::CalledStmt(Stmt *S) {
229 if (!S || ComputedEST == EST_MSAny)
230 return;
231
232 // FIXME:
233 //
234 // C++0x [except.spec]p14:
235 // [An] implicit exception-specification specifies the type-id T if and
236 // only if T is allowed by the exception-specification of a function directly
237 // invoked by f's implicit definition; f shall allow all exceptions if any
238 // function it directly invokes allows all exceptions, and f shall allow no
239 // exceptions if every function it directly invokes allows no exceptions.
240 //
241 // Note in particular that if an implicit exception-specification is generated
242 // for a function containing a throw-expression, that specification can still
243 // be noexcept(true).
244 //
245 // Note also that 'directly invoked' is not defined in the standard, and there
246 // is no indication that we should only consider potentially-evaluated calls.
247 //
248 // Ultimately we should implement the intent of the standard: the exception
249 // specification should be the set of exceptions which can be thrown by the
250 // implicit definition. For now, we assume that any non-nothrow expression can
251 // throw any exception.
252
253 if (Self->canThrow(S))
254 ComputedEST = EST_None;
255}
256
257ExprResult Sema::ConvertParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
258 SourceLocation EqualLoc) {
259 if (RequireCompleteType(Param->getLocation(), Param->getType(),
260 diag::err_typecheck_decl_incomplete_type))
261 return true;
262
263 // C++ [dcl.fct.default]p5
264 // A default argument expression is implicitly converted (clause
265 // 4) to the parameter type. The default argument expression has
266 // the same semantic constraints as the initializer expression in
267 // a declaration of a variable of the parameter type, using the
268 // copy-initialization semantics (8.5).
269 InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
270 Param);
271 InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
272 EqualLoc);
273 InitializationSequence InitSeq(*this, Entity, Kind, Arg);
274 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg);
275 if (Result.isInvalid())
276 return true;
277 Arg = Result.getAs<Expr>();
278
279 CheckCompletedExpr(Arg, EqualLoc);
280 Arg = MaybeCreateExprWithCleanups(Arg);
281
282 return Arg;
283}
284
285void Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
286 SourceLocation EqualLoc) {
287 // Add the default argument to the parameter
288 Param->setDefaultArg(Arg);
289
290 // We have already instantiated this parameter; provide each of the
291 // instantiations with the uninstantiated default argument.
292 UnparsedDefaultArgInstantiationsMap::iterator InstPos
293 = UnparsedDefaultArgInstantiations.find(Param);
294 if (InstPos != UnparsedDefaultArgInstantiations.end()) {
295 for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
296 InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
297
298 // We're done tracking this parameter's instantiations.
299 UnparsedDefaultArgInstantiations.erase(InstPos);
300 }
301}
302
303/// ActOnParamDefaultArgument - Check whether the default argument
304/// provided for a function parameter is well-formed. If so, attach it
305/// to the parameter declaration.
306void
307Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc,
308 Expr *DefaultArg) {
309 if (!param || !DefaultArg)
310 return;
311
312 ParmVarDecl *Param = cast<ParmVarDecl>(param);
313 UnparsedDefaultArgLocs.erase(Param);
314
315 auto Fail = [&] {
316 Param->setInvalidDecl();
317 Param->setDefaultArg(new (Context) OpaqueValueExpr(
318 EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue));
319 };
320
321 // Default arguments are only permitted in C++
322 if (!getLangOpts().CPlusPlus) {
323 Diag(EqualLoc, diag::err_param_default_argument)
324 << DefaultArg->getSourceRange();
325 return Fail();
326 }
327
328 // Check for unexpanded parameter packs.
329 if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
330 return Fail();
331 }
332
333 // C++11 [dcl.fct.default]p3
334 // A default argument expression [...] shall not be specified for a
335 // parameter pack.
336 if (Param->isParameterPack()) {
337 Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack)
338 << DefaultArg->getSourceRange();
339 // Recover by discarding the default argument.
340 Param->setDefaultArg(nullptr);
341 return;
342 }
343
344 ExprResult Result = ConvertParamDefaultArgument(Param, DefaultArg, EqualLoc);
345 if (Result.isInvalid())
346 return Fail();
347
348 DefaultArg = Result.getAs<Expr>();
349
350 // Check that the default argument is well-formed
351 CheckDefaultArgumentVisitor DefaultArgChecker(*this, DefaultArg);
352 if (DefaultArgChecker.Visit(DefaultArg))
353 return Fail();
354
355 SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
356}
357
358/// ActOnParamUnparsedDefaultArgument - We've seen a default
359/// argument for a function parameter, but we can't parse it yet
360/// because we're inside a class definition. Note that this default
361/// argument will be parsed later.
362void Sema::ActOnParamUnparsedDefaultArgument(Decl *param,
363 SourceLocation EqualLoc,
364 SourceLocation ArgLoc) {
365 if (!param)
366 return;
367
368 ParmVarDecl *Param = cast<ParmVarDecl>(param);
369 Param->setUnparsedDefaultArg();
370 UnparsedDefaultArgLocs[Param] = ArgLoc;
371}
372
373/// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
374/// the default argument for the parameter param failed.
375void Sema::ActOnParamDefaultArgumentError(Decl *param,
376 SourceLocation EqualLoc) {
377 if (!param)
378 return;
379
380 ParmVarDecl *Param = cast<ParmVarDecl>(param);
381 Param->setInvalidDecl();
382 UnparsedDefaultArgLocs.erase(Param);
383 Param->setDefaultArg(new (Context) OpaqueValueExpr(
384 EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue));
385}
386
387/// CheckExtraCXXDefaultArguments - Check for any extra default
388/// arguments in the declarator, which is not a function declaration
389/// or definition and therefore is not permitted to have default
390/// arguments. This routine should be invoked for every declarator
391/// that is not a function declaration or definition.
392void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
393 // C++ [dcl.fct.default]p3
394 // A default argument expression shall be specified only in the
395 // parameter-declaration-clause of a function declaration or in a
396 // template-parameter (14.1). It shall not be specified for a
397 // parameter pack. If it is specified in a
398 // parameter-declaration-clause, it shall not occur within a
399 // declarator or abstract-declarator of a parameter-declaration.
400 bool MightBeFunction = D.isFunctionDeclarationContext();
401 for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
402 DeclaratorChunk &chunk = D.getTypeObject(i);
403 if (chunk.Kind == DeclaratorChunk::Function) {
404 if (MightBeFunction) {
405 // This is a function declaration. It can have default arguments, but
406 // keep looking in case its return type is a function type with default
407 // arguments.
408 MightBeFunction = false;
409 continue;
410 }
411 for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e;
412 ++argIdx) {
413 ParmVarDecl *Param = cast<ParmVarDecl>(chunk.Fun.Params[argIdx].Param);
414 if (Param->hasUnparsedDefaultArg()) {
415 std::unique_ptr<CachedTokens> Toks =
416 std::move(chunk.Fun.Params[argIdx].DefaultArgTokens);
417 SourceRange SR;
418 if (Toks->size() > 1)
419 SR = SourceRange((*Toks)[1].getLocation(),
420 Toks->back().getLocation());
421 else
422 SR = UnparsedDefaultArgLocs[Param];
423 Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
424 << SR;
425 } else if (Param->getDefaultArg()) {
426 Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
427 << Param->getDefaultArg()->getSourceRange();
428 Param->setDefaultArg(nullptr);
429 }
430 }
431 } else if (chunk.Kind != DeclaratorChunk::Paren) {
432 MightBeFunction = false;
433 }
434 }
435}
436
437static bool functionDeclHasDefaultArgument(const FunctionDecl *FD) {
438 return std::any_of(FD->param_begin(), FD->param_end(), [](ParmVarDecl *P) {
439 return P->hasDefaultArg() && !P->hasInheritedDefaultArg();
440 });
441}
442
443/// MergeCXXFunctionDecl - Merge two declarations of the same C++
444/// function, once we already know that they have the same
445/// type. Subroutine of MergeFunctionDecl. Returns true if there was an
446/// error, false otherwise.
447bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old,
448 Scope *S) {
449 bool Invalid = false;
450
451 // The declaration context corresponding to the scope is the semantic
452 // parent, unless this is a local function declaration, in which case
453 // it is that surrounding function.
454 DeclContext *ScopeDC = New->isLocalExternDecl()
455 ? New->getLexicalDeclContext()
456 : New->getDeclContext();
457
458 // Find the previous declaration for the purpose of default arguments.
459 FunctionDecl *PrevForDefaultArgs = Old;
460 for (/**/; PrevForDefaultArgs;
461 // Don't bother looking back past the latest decl if this is a local
462 // extern declaration; nothing else could work.
463 PrevForDefaultArgs = New->isLocalExternDecl()
464 ? nullptr
465 : PrevForDefaultArgs->getPreviousDecl()) {
466 // Ignore hidden declarations.
467 if (!LookupResult::isVisible(*this, PrevForDefaultArgs))
468 continue;
469
470 if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) &&
471 !New->isCXXClassMember()) {
472 // Ignore default arguments of old decl if they are not in
473 // the same scope and this is not an out-of-line definition of
474 // a member function.
475 continue;
476 }
477
478 if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) {
479 // If only one of these is a local function declaration, then they are
480 // declared in different scopes, even though isDeclInScope may think
481 // they're in the same scope. (If both are local, the scope check is
482 // sufficient, and if neither is local, then they are in the same scope.)
483 continue;
484 }
485
486 // We found the right previous declaration.
487 break;
488 }
489
490 // C++ [dcl.fct.default]p4:
491 // For non-template functions, default arguments can be added in
492 // later declarations of a function in the same
493 // scope. Declarations in different scopes have completely
494 // distinct sets of default arguments. That is, declarations in
495 // inner scopes do not acquire default arguments from
496 // declarations in outer scopes, and vice versa. In a given
497 // function declaration, all parameters subsequent to a
498 // parameter with a default argument shall have default
499 // arguments supplied in this or previous declarations. A
500 // default argument shall not be redefined by a later
501 // declaration (not even to the same value).
502 //
503 // C++ [dcl.fct.default]p6:
504 // Except for member functions of class templates, the default arguments
505 // in a member function definition that appears outside of the class
506 // definition are added to the set of default arguments provided by the
507 // member function declaration in the class definition.
508 for (unsigned p = 0, NumParams = PrevForDefaultArgs
509 ? PrevForDefaultArgs->getNumParams()
510 : 0;
511 p < NumParams; ++p) {
512 ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p);
513 ParmVarDecl *NewParam = New->getParamDecl(p);
514
515 bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false;
516 bool NewParamHasDfl = NewParam->hasDefaultArg();
517
518 if (OldParamHasDfl && NewParamHasDfl) {
519 unsigned DiagDefaultParamID =
520 diag::err_param_default_argument_redefinition;
521
522 // MSVC accepts that default parameters be redefined for member functions
523 // of template class. The new default parameter's value is ignored.
524 Invalid = true;
525 if (getLangOpts().MicrosoftExt) {
526 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(New);
527 if (MD && MD->getParent()->getDescribedClassTemplate()) {
528 // Merge the old default argument into the new parameter.
529 NewParam->setHasInheritedDefaultArg();
530 if (OldParam->hasUninstantiatedDefaultArg())
531 NewParam->setUninstantiatedDefaultArg(
532 OldParam->getUninstantiatedDefaultArg());
533 else
534 NewParam->setDefaultArg(OldParam->getInit());
535 DiagDefaultParamID = diag::ext_param_default_argument_redefinition;
536 Invalid = false;
537 }
538 }
539
540 // FIXME: If we knew where the '=' was, we could easily provide a fix-it
541 // hint here. Alternatively, we could walk the type-source information
542 // for NewParam to find the last source location in the type... but it
543 // isn't worth the effort right now. This is the kind of test case that
544 // is hard to get right:
545 // int f(int);
546 // void g(int (*fp)(int) = f);
547 // void g(int (*fp)(int) = &f);
548 Diag(NewParam->getLocation(), DiagDefaultParamID)
549 << NewParam->getDefaultArgRange();
550
551 // Look for the function declaration where the default argument was
552 // actually written, which may be a declaration prior to Old.
553 for (auto Older = PrevForDefaultArgs;
554 OldParam->hasInheritedDefaultArg(); /**/) {
555 Older = Older->getPreviousDecl();
556 OldParam = Older->getParamDecl(p);
557 }
558
559 Diag(OldParam->getLocation(), diag::note_previous_definition)
560 << OldParam->getDefaultArgRange();
561 } else if (OldParamHasDfl) {
562 // Merge the old default argument into the new parameter unless the new
563 // function is a friend declaration in a template class. In the latter
564 // case the default arguments will be inherited when the friend
565 // declaration will be instantiated.
566 if (New->getFriendObjectKind() == Decl::FOK_None ||
567 !New->getLexicalDeclContext()->isDependentContext()) {
568 // It's important to use getInit() here; getDefaultArg()
569 // strips off any top-level ExprWithCleanups.
570 NewParam->setHasInheritedDefaultArg();
571 if (OldParam->hasUnparsedDefaultArg())
572 NewParam->setUnparsedDefaultArg();
573 else if (OldParam->hasUninstantiatedDefaultArg())
574 NewParam->setUninstantiatedDefaultArg(
575 OldParam->getUninstantiatedDefaultArg());
576 else
577 NewParam->setDefaultArg(OldParam->getInit());
578 }
579 } else if (NewParamHasDfl) {
580 if (New->getDescribedFunctionTemplate()) {
581 // Paragraph 4, quoted above, only applies to non-template functions.
582 Diag(NewParam->getLocation(),
583 diag::err_param_default_argument_template_redecl)
584 << NewParam->getDefaultArgRange();
585 Diag(PrevForDefaultArgs->getLocation(),
586 diag::note_template_prev_declaration)
587 << false;
588 } else if (New->getTemplateSpecializationKind()
589 != TSK_ImplicitInstantiation &&
590 New->getTemplateSpecializationKind() != TSK_Undeclared) {
591 // C++ [temp.expr.spec]p21:
592 // Default function arguments shall not be specified in a declaration
593 // or a definition for one of the following explicit specializations:
594 // - the explicit specialization of a function template;
595 // - the explicit specialization of a member function template;
596 // - the explicit specialization of a member function of a class
597 // template where the class template specialization to which the
598 // member function specialization belongs is implicitly
599 // instantiated.
600 Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
601 << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
602 << New->getDeclName()
603 << NewParam->getDefaultArgRange();
604 } else if (New->getDeclContext()->isDependentContext()) {
605 // C++ [dcl.fct.default]p6 (DR217):
606 // Default arguments for a member function of a class template shall
607 // be specified on the initial declaration of the member function
608 // within the class template.
609 //
610 // Reading the tea leaves a bit in DR217 and its reference to DR205
611 // leads me to the conclusion that one cannot add default function
612 // arguments for an out-of-line definition of a member function of a
613 // dependent type.
614 int WhichKind = 2;
615 if (CXXRecordDecl *Record
616 = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
617 if (Record->getDescribedClassTemplate())
618 WhichKind = 0;
619 else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
620 WhichKind = 1;
621 else
622 WhichKind = 2;
623 }
624
625 Diag(NewParam->getLocation(),
626 diag::err_param_default_argument_member_template_redecl)
627 << WhichKind
628 << NewParam->getDefaultArgRange();
629 }
630 }
631 }
632
633 // DR1344: If a default argument is added outside a class definition and that
634 // default argument makes the function a special member function, the program
635 // is ill-formed. This can only happen for constructors.
636 if (isa<CXXConstructorDecl>(New) &&
637 New->getMinRequiredArguments() < Old->getMinRequiredArguments()) {
638 CXXSpecialMember NewSM = getSpecialMember(cast<CXXMethodDecl>(New)),
639 OldSM = getSpecialMember(cast<CXXMethodDecl>(Old));
640 if (NewSM != OldSM) {
641 ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments());
642 assert(NewParam->hasDefaultArg())((void)0);
643 Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special)
644 << NewParam->getDefaultArgRange() << NewSM;
645 Diag(Old->getLocation(), diag::note_previous_declaration);
646 }
647 }
648
649 const FunctionDecl *Def;
650 // C++11 [dcl.constexpr]p1: If any declaration of a function or function
651 // template has a constexpr specifier then all its declarations shall
652 // contain the constexpr specifier.
653 if (New->getConstexprKind() != Old->getConstexprKind()) {
654 Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
655 << New << static_cast<int>(New->getConstexprKind())
656 << static_cast<int>(Old->getConstexprKind());
657 Diag(Old->getLocation(), diag::note_previous_declaration);
658 Invalid = true;
659 } else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() &&
660 Old->isDefined(Def) &&
661 // If a friend function is inlined but does not have 'inline'
662 // specifier, it is a definition. Do not report attribute conflict
663 // in this case, redefinition will be diagnosed later.
664 (New->isInlineSpecified() ||
665 New->getFriendObjectKind() == Decl::FOK_None)) {
666 // C++11 [dcl.fcn.spec]p4:
667 // If the definition of a function appears in a translation unit before its
668 // first declaration as inline, the program is ill-formed.
669 Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
670 Diag(Def->getLocation(), diag::note_previous_definition);
671 Invalid = true;
672 }
673
674 // C++17 [temp.deduct.guide]p3:
675 // Two deduction guide declarations in the same translation unit
676 // for the same class template shall not have equivalent
677 // parameter-declaration-clauses.
678 if (isa<CXXDeductionGuideDecl>(New) &&
679 !New->isFunctionTemplateSpecialization() && isVisible(Old)) {
680 Diag(New->getLocation(), diag::err_deduction_guide_redeclared);
681 Diag(Old->getLocation(), diag::note_previous_declaration);
682 }
683
684 // C++11 [dcl.fct.default]p4: If a friend declaration specifies a default
685 // argument expression, that declaration shall be a definition and shall be
686 // the only declaration of the function or function template in the
687 // translation unit.
688 if (Old->getFriendObjectKind() == Decl::FOK_Undeclared &&
689 functionDeclHasDefaultArgument(Old)) {
690 Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
691 Diag(Old->getLocation(), diag::note_previous_declaration);
692 Invalid = true;
693 }
694
695 // C++11 [temp.friend]p4 (DR329):
696 // When a function is defined in a friend function declaration in a class
697 // template, the function is instantiated when the function is odr-used.
698 // The same restrictions on multiple declarations and definitions that
699 // apply to non-template function declarations and definitions also apply
700 // to these implicit definitions.
701 const FunctionDecl *OldDefinition = nullptr;
702 if (New->isThisDeclarationInstantiatedFromAFriendDefinition() &&
703 Old->isDefined(OldDefinition, true))
704 CheckForFunctionRedefinition(New, OldDefinition);
705
706 return Invalid;
707}
708
709NamedDecl *
710Sema::ActOnDecompositionDeclarator(Scope *S, Declarator &D,
711 MultiTemplateParamsArg TemplateParamLists) {
712 assert(D.isDecompositionDeclarator())((void)0);
713 const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator();
714
715 // The syntax only allows a decomposition declarator as a simple-declaration,
716 // a for-range-declaration, or a condition in Clang, but we parse it in more
717 // cases than that.
718 if (!D.mayHaveDecompositionDeclarator()) {
719 Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
720 << Decomp.getSourceRange();
721 return nullptr;
722 }
723
724 if (!TemplateParamLists.empty()) {
725 // FIXME: There's no rule against this, but there are also no rules that
726 // would actually make it usable, so we reject it for now.
727 Diag(TemplateParamLists.front()->getTemplateLoc(),
728 diag::err_decomp_decl_template);
729 return nullptr;
730 }
731
732 Diag(Decomp.getLSquareLoc(),
733 !getLangOpts().CPlusPlus17
734 ? diag::ext_decomp_decl
735 : D.getContext() == DeclaratorContext::Condition
736 ? diag::ext_decomp_decl_cond
737 : diag::warn_cxx14_compat_decomp_decl)
738 << Decomp.getSourceRange();
739
740 // The semantic context is always just the current context.
741 DeclContext *const DC = CurContext;
742
743 // C++17 [dcl.dcl]/8:
744 // The decl-specifier-seq shall contain only the type-specifier auto
745 // and cv-qualifiers.
746 // C++2a [dcl.dcl]/8:
747 // If decl-specifier-seq contains any decl-specifier other than static,
748 // thread_local, auto, or cv-qualifiers, the program is ill-formed.
749 auto &DS = D.getDeclSpec();
750 {
751 SmallVector<StringRef, 8> BadSpecifiers;
752 SmallVector<SourceLocation, 8> BadSpecifierLocs;
753 SmallVector<StringRef, 8> CPlusPlus20Specifiers;
754 SmallVector<SourceLocation, 8> CPlusPlus20SpecifierLocs;
755 if (auto SCS = DS.getStorageClassSpec()) {
756 if (SCS == DeclSpec::SCS_static) {
757 CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(SCS));
758 CPlusPlus20SpecifierLocs.push_back(DS.getStorageClassSpecLoc());
759 } else {
760 BadSpecifiers.push_back(DeclSpec::getSpecifierName(SCS));
761 BadSpecifierLocs.push_back(DS.getStorageClassSpecLoc());
762 }
763 }
764 if (auto TSCS = DS.getThreadStorageClassSpec()) {
765 CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(TSCS));
766 CPlusPlus20SpecifierLocs.push_back(DS.getThreadStorageClassSpecLoc());
767 }
768 if (DS.hasConstexprSpecifier()) {
769 BadSpecifiers.push_back(
770 DeclSpec::getSpecifierName(DS.getConstexprSpecifier()));
771 BadSpecifierLocs.push_back(DS.getConstexprSpecLoc());
772 }
773 if (DS.isInlineSpecified()) {
774 BadSpecifiers.push_back("inline");
775 BadSpecifierLocs.push_back(DS.getInlineSpecLoc());
776 }
777 if (!BadSpecifiers.empty()) {
778 auto &&Err = Diag(BadSpecifierLocs.front(), diag::err_decomp_decl_spec);
779 Err << (int)BadSpecifiers.size()
780 << llvm::join(BadSpecifiers.begin(), BadSpecifiers.end(), " ");
781 // Don't add FixItHints to remove the specifiers; we do still respect
782 // them when building the underlying variable.
783 for (auto Loc : BadSpecifierLocs)
784 Err << SourceRange(Loc, Loc);
785 } else if (!CPlusPlus20Specifiers.empty()) {
786 auto &&Warn = Diag(CPlusPlus20SpecifierLocs.front(),
787 getLangOpts().CPlusPlus20
788 ? diag::warn_cxx17_compat_decomp_decl_spec
789 : diag::ext_decomp_decl_spec);
790 Warn << (int)CPlusPlus20Specifiers.size()
791 << llvm::join(CPlusPlus20Specifiers.begin(),
792 CPlusPlus20Specifiers.end(), " ");
793 for (auto Loc : CPlusPlus20SpecifierLocs)
794 Warn << SourceRange(Loc, Loc);
795 }
796 // We can't recover from it being declared as a typedef.
797 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
798 return nullptr;
799 }
800
801 // C++2a [dcl.struct.bind]p1:
802 // A cv that includes volatile is deprecated
803 if ((DS.getTypeQualifiers() & DeclSpec::TQ_volatile) &&
804 getLangOpts().CPlusPlus20)
805 Diag(DS.getVolatileSpecLoc(),
806 diag::warn_deprecated_volatile_structured_binding);
807
808 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
809 QualType R = TInfo->getType();
810
811 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
812 UPPC_DeclarationType))
813 D.setInvalidType();
814
815 // The syntax only allows a single ref-qualifier prior to the decomposition
816 // declarator. No other declarator chunks are permitted. Also check the type
817 // specifier here.
818 if (DS.getTypeSpecType() != DeclSpec::TST_auto ||
819 D.hasGroupingParens() || D.getNumTypeObjects() > 1 ||
820 (D.getNumTypeObjects() == 1 &&
821 D.getTypeObject(0).Kind != DeclaratorChunk::Reference)) {
822 Diag(Decomp.getLSquareLoc(),
823 (D.hasGroupingParens() ||
824 (D.getNumTypeObjects() &&
825 D.getTypeObject(0).Kind == DeclaratorChunk::Paren))
826 ? diag::err_decomp_decl_parens
827 : diag::err_decomp_decl_type)
828 << R;
829
830 // In most cases, there's no actual problem with an explicitly-specified
831 // type, but a function type won't work here, and ActOnVariableDeclarator
832 // shouldn't be called for such a type.
833 if (R->isFunctionType())
834 D.setInvalidType();
835 }
836
837 // Build the BindingDecls.
838 SmallVector<BindingDecl*, 8> Bindings;
839
840 // Build the BindingDecls.
841 for (auto &B : D.getDecompositionDeclarator().bindings()) {
842 // Check for name conflicts.
843 DeclarationNameInfo NameInfo(B.Name, B.NameLoc);
844 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
845 ForVisibleRedeclaration);
846 LookupName(Previous, S,
847 /*CreateBuiltins*/DC->getRedeclContext()->isTranslationUnit());
848
849 // It's not permitted to shadow a template parameter name.
850 if (Previous.isSingleResult() &&
851 Previous.getFoundDecl()->isTemplateParameter()) {
852 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
853 Previous.getFoundDecl());
854 Previous.clear();
855 }
856
857 auto *BD = BindingDecl::Create(Context, DC, B.NameLoc, B.Name);
858
859 // Find the shadowed declaration before filtering for scope.
860 NamedDecl *ShadowedDecl = D.getCXXScopeSpec().isEmpty()
861 ? getShadowedDeclaration(BD, Previous)
862 : nullptr;
863
864 bool ConsiderLinkage = DC->isFunctionOrMethod() &&
865 DS.getStorageClassSpec() == DeclSpec::SCS_extern;
866 FilterLookupForScope(Previous, DC, S, ConsiderLinkage,
867 /*AllowInlineNamespace*/false);
868
869 if (!Previous.empty()) {
870 auto *Old = Previous.getRepresentativeDecl();
871 Diag(B.NameLoc, diag::err_redefinition) << B.Name;
872 Diag(Old->getLocation(), diag::note_previous_definition);
873 } else if (ShadowedDecl && !D.isRedeclaration()) {
874 CheckShadow(BD, ShadowedDecl, Previous);
875 }
876 PushOnScopeChains(BD, S, true);
877 Bindings.push_back(BD);
878 ParsingInitForAutoVars.insert(BD);
879 }
880
881 // There are no prior lookup results for the variable itself, because it
882 // is unnamed.
883 DeclarationNameInfo NameInfo((IdentifierInfo *)nullptr,
884 Decomp.getLSquareLoc());
885 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
886 ForVisibleRedeclaration);
887
888 // Build the variable that holds the non-decomposed object.
889 bool AddToScope = true;
890 NamedDecl *New =
891 ActOnVariableDeclarator(S, D, DC, TInfo, Previous,
892 MultiTemplateParamsArg(), AddToScope, Bindings);
893 if (AddToScope) {
894 S->AddDecl(New);
895 CurContext->addHiddenDecl(New);
896 }
897
898 if (isInOpenMPDeclareTargetContext())
899 checkDeclIsAllowedInOpenMPTarget(nullptr, New);
900
901 return New;
902}
903
904static bool checkSimpleDecomposition(
905 Sema &S, ArrayRef<BindingDecl *> Bindings, ValueDecl *Src,
906 QualType DecompType, const llvm::APSInt &NumElems, QualType ElemType,
907 llvm::function_ref<ExprResult(SourceLocation, Expr *, unsigned)> GetInit) {
908 if ((int64_t)Bindings.size() != NumElems) {
909 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
910 << DecompType << (unsigned)Bindings.size()
911 << (unsigned)NumElems.getLimitedValue(UINT_MAX(2147483647 *2U +1U))
912 << toString(NumElems, 10) << (NumElems < Bindings.size());
913 return true;
914 }
915
916 unsigned I = 0;
917 for (auto *B : Bindings) {
918 SourceLocation Loc = B->getLocation();
919 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
920 if (E.isInvalid())
921 return true;
922 E = GetInit(Loc, E.get(), I++);
923 if (E.isInvalid())
924 return true;
925 B->setBinding(ElemType, E.get());
926 }
927
928 return false;
929}
930
931static bool checkArrayLikeDecomposition(Sema &S,
932 ArrayRef<BindingDecl *> Bindings,
933 ValueDecl *Src, QualType DecompType,
934 const llvm::APSInt &NumElems,
935 QualType ElemType) {
936 return checkSimpleDecomposition(
937 S, Bindings, Src, DecompType, NumElems, ElemType,
938 [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
939 ExprResult E = S.ActOnIntegerConstant(Loc, I);
940 if (E.isInvalid())
941 return ExprError();
942 return S.CreateBuiltinArraySubscriptExpr(Base, Loc, E.get(), Loc);
943 });
944}
945
946static bool checkArrayDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
947 ValueDecl *Src, QualType DecompType,
948 const ConstantArrayType *CAT) {
949 return checkArrayLikeDecomposition(S, Bindings, Src, DecompType,
950 llvm::APSInt(CAT->getSize()),
951 CAT->getElementType());
952}
953
954static bool checkVectorDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
955 ValueDecl *Src, QualType DecompType,
956 const VectorType *VT) {
957 return checkArrayLikeDecomposition(
958 S, Bindings, Src, DecompType, llvm::APSInt::get(VT->getNumElements()),
959 S.Context.getQualifiedType(VT->getElementType(),
960 DecompType.getQualifiers()));
961}
962
963static bool checkComplexDecomposition(Sema &S,
964 ArrayRef<BindingDecl *> Bindings,
965 ValueDecl *Src, QualType DecompType,
966 const ComplexType *CT) {
967 return checkSimpleDecomposition(
968 S, Bindings, Src, DecompType, llvm::APSInt::get(2),
969 S.Context.getQualifiedType(CT->getElementType(),
970 DecompType.getQualifiers()),
971 [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
972 return S.CreateBuiltinUnaryOp(Loc, I ? UO_Imag : UO_Real, Base);
973 });
974}
975
976static std::string printTemplateArgs(const PrintingPolicy &PrintingPolicy,
977 TemplateArgumentListInfo &Args,
978 const TemplateParameterList *Params) {
979 SmallString<128> SS;
980 llvm::raw_svector_ostream OS(SS);
981 bool First = true;
982 unsigned I = 0;
983 for (auto &Arg : Args.arguments()) {
984 if (!First)
985 OS << ", ";
986 Arg.getArgument().print(
987 PrintingPolicy, OS,
988 TemplateParameterList::shouldIncludeTypeForArgument(Params, I));
989 First = false;
990 I++;
991 }
992 return std::string(OS.str());
993}
994
995static bool lookupStdTypeTraitMember(Sema &S, LookupResult &TraitMemberLookup,
996 SourceLocation Loc, StringRef Trait,
997 TemplateArgumentListInfo &Args,
998 unsigned DiagID) {
999 auto DiagnoseMissing = [&] {
1000 if (DiagID)
1001 S.Diag(Loc, DiagID) << printTemplateArgs(S.Context.getPrintingPolicy(),
1002 Args, /*Params*/ nullptr);
1003 return true;
1004 };
1005
1006 // FIXME: Factor out duplication with lookupPromiseType in SemaCoroutine.
1007 NamespaceDecl *Std = S.getStdNamespace();
1008 if (!Std)
1009 return DiagnoseMissing();
1010
1011 // Look up the trait itself, within namespace std. We can diagnose various
1012 // problems with this lookup even if we've been asked to not diagnose a
1013 // missing specialization, because this can only fail if the user has been
1014 // declaring their own names in namespace std or we don't support the
1015 // standard library implementation in use.
1016 LookupResult Result(S, &S.PP.getIdentifierTable().get(Trait),
1017 Loc, Sema::LookupOrdinaryName);
1018 if (!S.LookupQualifiedName(Result, Std))
1019 return DiagnoseMissing();
1020 if (Result.isAmbiguous())
1021 return true;
1022
1023 ClassTemplateDecl *TraitTD = Result.getAsSingle<ClassTemplateDecl>();
1024 if (!TraitTD) {
1025 Result.suppressDiagnostics();
1026 NamedDecl *Found = *Result.begin();
1027 S.Diag(Loc, diag::err_std_type_trait_not_class_template) << Trait;
1028 S.Diag(Found->getLocation(), diag::note_declared_at);
1029 return true;
1030 }
1031
1032 // Build the template-id.
1033 QualType TraitTy = S.CheckTemplateIdType(TemplateName(TraitTD), Loc, Args);
1034 if (TraitTy.isNull())
1035 return true;
1036 if (!S.isCompleteType(Loc, TraitTy)) {
1037 if (DiagID)
1038 S.RequireCompleteType(
1039 Loc, TraitTy, DiagID,
1040 printTemplateArgs(S.Context.getPrintingPolicy(), Args,
1041 TraitTD->getTemplateParameters()));
1042 return true;
1043 }
1044
1045 CXXRecordDecl *RD = TraitTy->getAsCXXRecordDecl();
1046 assert(RD && "specialization of class template is not a class?")((void)0);
1047
1048 // Look up the member of the trait type.
1049 S.LookupQualifiedName(TraitMemberLookup, RD);
1050 return TraitMemberLookup.isAmbiguous();
1051}
1052
1053static TemplateArgumentLoc
1054getTrivialIntegralTemplateArgument(Sema &S, SourceLocation Loc, QualType T,
1055 uint64_t I) {
1056 TemplateArgument Arg(S.Context, S.Context.MakeIntValue(I, T), T);
1057 return S.getTrivialTemplateArgumentLoc(Arg, T, Loc);
1058}
1059
1060static TemplateArgumentLoc
1061getTrivialTypeTemplateArgument(Sema &S, SourceLocation Loc, QualType T) {
1062 return S.getTrivialTemplateArgumentLoc(TemplateArgument(T), QualType(), Loc);
1063}
1064
1065namespace { enum class IsTupleLike { TupleLike, NotTupleLike, Error }; }
1066
1067static IsTupleLike isTupleLike(Sema &S, SourceLocation Loc, QualType T,
1068 llvm::APSInt &Size) {
1069 EnterExpressionEvaluationContext ContextRAII(
1070 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
1071
1072 DeclarationName Value = S.PP.getIdentifierInfo("value");
1073 LookupResult R(S, Value, Loc, Sema::LookupOrdinaryName);
1074
1075 // Form template argument list for tuple_size<T>.
1076 TemplateArgumentListInfo Args(Loc, Loc);
1077 Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));
1078
1079 // If there's no tuple_size specialization or the lookup of 'value' is empty,
1080 // it's not tuple-like.
1081 if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/ 0) ||
1082 R.empty())
1083 return IsTupleLike::NotTupleLike;
1084
1085 // If we get this far, we've committed to the tuple interpretation, but
1086 // we can still fail if there actually isn't a usable ::value.
1087
1088 struct ICEDiagnoser : Sema::VerifyICEDiagnoser {
1089 LookupResult &R;
1090 TemplateArgumentListInfo &Args;
1091 ICEDiagnoser(LookupResult &R, TemplateArgumentListInfo &Args)
1092 : R(R), Args(Args) {}
1093 Sema::SemaDiagnosticBuilder diagnoseNotICE(Sema &S,
1094 SourceLocation Loc) override {
1095 return S.Diag(Loc, diag::err_decomp_decl_std_tuple_size_not_constant)
1096 << printTemplateArgs(S.Context.getPrintingPolicy(), Args,
1097 /*Params*/ nullptr);
1098 }
1099 } Diagnoser(R, Args);
1100
1101 ExprResult E =
1102 S.BuildDeclarationNameExpr(CXXScopeSpec(), R, /*NeedsADL*/false);
1103 if (E.isInvalid())
1104 return IsTupleLike::Error;
1105
1106 E = S.VerifyIntegerConstantExpression(E.get(), &Size, Diagnoser);
1107 if (E.isInvalid())
1108 return IsTupleLike::Error;
1109
1110 return IsTupleLike::TupleLike;
1111}
1112
1113/// \return std::tuple_element<I, T>::type.
1114static QualType getTupleLikeElementType(Sema &S, SourceLocation Loc,
1115 unsigned I, QualType T) {
1116 // Form template argument list for tuple_element<I, T>.
1117 TemplateArgumentListInfo Args(Loc, Loc);
1118 Args.addArgument(
1119 getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
1120 Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));
1121
1122 DeclarationName TypeDN = S.PP.getIdentifierInfo("type");
1123 LookupResult R(S, TypeDN, Loc, Sema::LookupOrdinaryName);
1124 if (lookupStdTypeTraitMember(
1125 S, R, Loc, "tuple_element", Args,
1126 diag::err_decomp_decl_std_tuple_element_not_specialized))
1127 return QualType();
1128
1129 auto *TD = R.getAsSingle<TypeDecl>();
1130 if (!TD) {
1131 R.suppressDiagnostics();
1132 S.Diag(Loc, diag::err_decomp_decl_std_tuple_element_not_specialized)
1133 << printTemplateArgs(S.Context.getPrintingPolicy(), Args,
1134 /*Params*/ nullptr);
1135 if (!R.empty())
1136 S.Diag(R.getRepresentativeDecl()->getLocation(), diag::note_declared_at);
1137 return QualType();
1138 }
1139
1140 return S.Context.getTypeDeclType(TD);
1141}
1142
1143namespace {
1144struct InitializingBinding {
1145 Sema &S;
1146 InitializingBinding(Sema &S, BindingDecl *BD) : S(S) {
1147 Sema::CodeSynthesisContext Ctx;
1148 Ctx.Kind = Sema::CodeSynthesisContext::InitializingStructuredBinding;
1149 Ctx.PointOfInstantiation = BD->getLocation();
1150 Ctx.Entity = BD;
1151 S.pushCodeSynthesisContext(Ctx);
1152 }
1153 ~InitializingBinding() {
1154 S.popCodeSynthesisContext();
1155 }
1156};
1157}
1158
1159static bool checkTupleLikeDecomposition(Sema &S,
1160 ArrayRef<BindingDecl *> Bindings,
1161 VarDecl *Src, QualType DecompType,
1162 const llvm::APSInt &TupleSize) {
1163 if ((int64_t)Bindings.size() != TupleSize) {
1164 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1165 << DecompType << (unsigned)Bindings.size()
1166 << (unsigned)TupleSize.getLimitedValue(UINT_MAX(2147483647 *2U +1U))
1167 << toString(TupleSize, 10) << (TupleSize < Bindings.size());
1168 return true;
1169 }
1170
1171 if (Bindings.empty())
1172 return false;
1173
1174 DeclarationName GetDN = S.PP.getIdentifierInfo("get");
1175
1176 // [dcl.decomp]p3:
1177 // The unqualified-id get is looked up in the scope of E by class member
1178 // access lookup ...
1179 LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName);
1180 bool UseMemberGet = false;
1181 if (S.isCompleteType(Src->getLocation(), DecompType)) {
1182 if (auto *RD = DecompType->getAsCXXRecordDecl())
1183 S.LookupQualifiedName(MemberGet, RD);
1184 if (MemberGet.isAmbiguous())
1185 return true;
1186 // ... and if that finds at least one declaration that is a function
1187 // template whose first template parameter is a non-type parameter ...
1188 for (NamedDecl *D : MemberGet) {
1189 if (FunctionTemplateDecl *FTD =
1190 dyn_cast<FunctionTemplateDecl>(D->getUnderlyingDecl())) {
1191 TemplateParameterList *TPL = FTD->getTemplateParameters();
1192 if (TPL->size() != 0 &&
1193 isa<NonTypeTemplateParmDecl>(TPL->getParam(0))) {
1194 // ... the initializer is e.get<i>().
1195 UseMemberGet = true;
1196 break;
1197 }
1198 }
1199 }
1200 }
1201
1202 unsigned I = 0;
1203 for (auto *B : Bindings) {
1204 InitializingBinding InitContext(S, B);
1205 SourceLocation Loc = B->getLocation();
1206
1207 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1208 if (E.isInvalid())
1209 return true;
1210
1211 // e is an lvalue if the type of the entity is an lvalue reference and
1212 // an xvalue otherwise
1213 if (!Src->getType()->isLValueReferenceType())
1214 E = ImplicitCastExpr::Create(S.Context, E.get()->getType(), CK_NoOp,
1215 E.get(), nullptr, VK_XValue,
1216 FPOptionsOverride());
1217
1218 TemplateArgumentListInfo Args(Loc, Loc);
1219 Args.addArgument(
1220 getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
1221
1222 if (UseMemberGet) {
1223 // if [lookup of member get] finds at least one declaration, the
1224 // initializer is e.get<i-1>().
1225 E = S.BuildMemberReferenceExpr(E.get(), DecompType, Loc, false,
1226 CXXScopeSpec(), SourceLocation(), nullptr,
1227 MemberGet, &Args, nullptr);
1228 if (E.isInvalid())
1229 return true;
1230
1231 E = S.BuildCallExpr(nullptr, E.get(), Loc, None, Loc);
1232 } else {
1233 // Otherwise, the initializer is get<i-1>(e), where get is looked up
1234 // in the associated namespaces.
1235 Expr *Get = UnresolvedLookupExpr::Create(
1236 S.Context, nullptr, NestedNameSpecifierLoc(), SourceLocation(),
1237 DeclarationNameInfo(GetDN, Loc), /*RequiresADL*/true, &Args,
1238 UnresolvedSetIterator(), UnresolvedSetIterator());
1239
1240 Expr *Arg = E.get();
1241 E = S.BuildCallExpr(nullptr, Get, Loc, Arg, Loc);
1242 }
1243 if (E.isInvalid())
1244 return true;
1245 Expr *Init = E.get();
1246
1247 // Given the type T designated by std::tuple_element<i - 1, E>::type,
1248 QualType T = getTupleLikeElementType(S, Loc, I, DecompType);
1249 if (T.isNull())
1250 return true;
1251
1252 // each vi is a variable of type "reference to T" initialized with the
1253 // initializer, where the reference is an lvalue reference if the
1254 // initializer is an lvalue and an rvalue reference otherwise
1255 QualType RefType =
1256 S.BuildReferenceType(T, E.get()->isLValue(), Loc, B->getDeclName());
1257 if (RefType.isNull())
1258 return true;
1259 auto *RefVD = VarDecl::Create(
1260 S.Context, Src->getDeclContext(), Loc, Loc,
1261 B->getDeclName().getAsIdentifierInfo(), RefType,
1262 S.Context.getTrivialTypeSourceInfo(T, Loc), Src->getStorageClass());
1263 RefVD->setLexicalDeclContext(Src->getLexicalDeclContext());
1264 RefVD->setTSCSpec(Src->getTSCSpec());
1265 RefVD->setImplicit();
1266 if (Src->isInlineSpecified())
1267 RefVD->setInlineSpecified();
1268 RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);
1269
1270 InitializedEntity Entity = InitializedEntity::InitializeBinding(RefVD);
1271 InitializationKind Kind = InitializationKind::CreateCopy(Loc, Loc);
1272 InitializationSequence Seq(S, Entity, Kind, Init);
1273 E = Seq.Perform(S, Entity, Kind, Init);
1274 if (E.isInvalid())
1275 return true;
1276 E = S.ActOnFinishFullExpr(E.get(), Loc, /*DiscardedValue*/ false);
1277 if (E.isInvalid())
1278 return true;
1279 RefVD->setInit(E.get());
1280 S.CheckCompleteVariableDeclaration(RefVD);
1281
1282 E = S.BuildDeclarationNameExpr(CXXScopeSpec(),
1283 DeclarationNameInfo(B->getDeclName(), Loc),
1284 RefVD);
1285 if (E.isInvalid())
1286 return true;
1287
1288 B->setBinding(T, E.get());
1289 I++;
1290 }
1291
1292 return false;
1293}
1294
1295/// Find the base class to decompose in a built-in decomposition of a class type.
1296/// This base class search is, unfortunately, not quite like any other that we
1297/// perform anywhere else in C++.
1298static DeclAccessPair findDecomposableBaseClass(Sema &S, SourceLocation Loc,
1299 const CXXRecordDecl *RD,
1300 CXXCastPath &BasePath) {
1301 auto BaseHasFields = [](const CXXBaseSpecifier *Specifier,
1302 CXXBasePath &Path) {
1303 return Specifier->getType()->getAsCXXRecordDecl()->hasDirectFields();
1304 };
1305
1306 const CXXRecordDecl *ClassWithFields = nullptr;
1307 AccessSpecifier AS = AS_public;
1308 if (RD->hasDirectFields())
1309 // [dcl.decomp]p4:
1310 // Otherwise, all of E's non-static data members shall be public direct
1311 // members of E ...
1312 ClassWithFields = RD;
1313 else {
1314 // ... or of ...
1315 CXXBasePaths Paths;
1316 Paths.setOrigin(const_cast<CXXRecordDecl*>(RD));
1317 if (!RD->lookupInBases(BaseHasFields, Paths)) {
1318 // If no classes have fields, just decompose RD itself. (This will work
1319 // if and only if zero bindings were provided.)
1320 return DeclAccessPair::make(const_cast<CXXRecordDecl*>(RD), AS_public);
1321 }
1322
1323 CXXBasePath *BestPath = nullptr;
1324 for (auto &P : Paths) {
1325 if (!BestPath)
1326 BestPath = &P;
1327 else if (!S.Context.hasSameType(P.back().Base->getType(),
1328 BestPath->back().Base->getType())) {
1329 // ... the same ...
1330 S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1331 << false << RD << BestPath->back().Base->getType()
1332 << P.back().Base->getType();
1333 return DeclAccessPair();
1334 } else if (P.Access < BestPath->Access) {
1335 BestPath = &P;
1336 }
1337 }
1338
1339 // ... unambiguous ...
1340 QualType BaseType = BestPath->back().Base->getType();
1341 if (Paths.isAmbiguous(S.Context.getCanonicalType(BaseType))) {
1342 S.Diag(Loc, diag::err_decomp_decl_ambiguous_base)
1343 << RD << BaseType << S.getAmbiguousPathsDisplayString(Paths);
1344 return DeclAccessPair();
1345 }
1346
1347 // ... [accessible, implied by other rules] base class of E.
1348 S.CheckBaseClassAccess(Loc, BaseType, S.Context.getRecordType(RD),
1349 *BestPath, diag::err_decomp_decl_inaccessible_base);
1350 AS = BestPath->Access;
1351
1352 ClassWithFields = BaseType->getAsCXXRecordDecl();
1353 S.BuildBasePathArray(Paths, BasePath);
1354 }
1355
1356 // The above search did not check whether the selected class itself has base
1357 // classes with fields, so check that now.
1358 CXXBasePaths Paths;
1359 if (ClassWithFields->lookupInBases(BaseHasFields, Paths)) {
1360 S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1361 << (ClassWithFields == RD) << RD << ClassWithFields
1362 << Paths.front().back().Base->getType();
1363 return DeclAccessPair();
1364 }
1365
1366 return DeclAccessPair::make(const_cast<CXXRecordDecl*>(ClassWithFields), AS);
1367}
1368
1369static bool checkMemberDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
1370 ValueDecl *Src, QualType DecompType,
1371 const CXXRecordDecl *OrigRD) {
1372 if (S.RequireCompleteType(Src->getLocation(), DecompType,
1373 diag::err_incomplete_type))
1374 return true;
1375
1376 CXXCastPath BasePath;
1377 DeclAccessPair BasePair =
1378 findDecomposableBaseClass(S, Src->getLocation(), OrigRD, BasePath);
1379 const CXXRecordDecl *RD = cast_or_null<CXXRecordDecl>(BasePair.getDecl());
1380 if (!RD)
1381 return true;
1382 QualType BaseType = S.Context.getQualifiedType(S.Context.getRecordType(RD),
1383 DecompType.getQualifiers());
1384
1385 auto DiagnoseBadNumberOfBindings = [&]() -> bool {
1386 unsigned NumFields =
1387 std::count_if(RD->field_begin(), RD->field_end(),
1388 [](FieldDecl *FD) { return !FD->isUnnamedBitfield(); });
1389 assert(Bindings.size() != NumFields)((void)0);
1390 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1391 << DecompType << (unsigned)Bindings.size() << NumFields << NumFields
1392 << (NumFields < Bindings.size());
1393 return true;
1394 };
1395
1396 // all of E's non-static data members shall be [...] well-formed
1397 // when named as e.name in the context of the structured binding,
1398 // E shall not have an anonymous union member, ...
1399 unsigned I = 0;
1400 for (auto *FD : RD->fields()) {
1401 if (FD->isUnnamedBitfield())
1402 continue;
1403
1404 // All the non-static data members are required to be nameable, so they
1405 // must all have names.
1406 if (!FD->getDeclName()) {
1407 if (RD->isLambda()) {
1408 S.Diag(Src->getLocation(), diag::err_decomp_decl_lambda);
1409 S.Diag(RD->getLocation(), diag::note_lambda_decl);
1410 return true;
1411 }
1412
1413 if (FD->isAnonymousStructOrUnion()) {
1414 S.Diag(Src->getLocation(), diag::err_decomp_decl_anon_union_member)
1415 << DecompType << FD->getType()->isUnionType();
1416 S.Diag(FD->getLocation(), diag::note_declared_at);
1417 return true;
1418 }
1419
1420 // FIXME: Are there any other ways we could have an anonymous member?
1421 }
1422
1423 // We have a real field to bind.
1424 if (I >= Bindings.size())
1425 return DiagnoseBadNumberOfBindings();
1426 auto *B = Bindings[I++];
1427 SourceLocation Loc = B->getLocation();
1428
1429 // The field must be accessible in the context of the structured binding.
1430 // We already checked that the base class is accessible.
1431 // FIXME: Add 'const' to AccessedEntity's classes so we can remove the
1432 // const_cast here.
1433 S.CheckStructuredBindingMemberAccess(
1434 Loc, const_cast<CXXRecordDecl *>(OrigRD),
1435 DeclAccessPair::make(FD, CXXRecordDecl::MergeAccess(
1436 BasePair.getAccess(), FD->getAccess())));
1437
1438 // Initialize the binding to Src.FD.
1439 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1440 if (E.isInvalid())
1441 return true;
1442 E = S.ImpCastExprToType(E.get(), BaseType, CK_UncheckedDerivedToBase,
1443 VK_LValue, &BasePath);
1444 if (E.isInvalid())
1445 return true;
1446 E = S.BuildFieldReferenceExpr(E.get(), /*IsArrow*/ false, Loc,
1447 CXXScopeSpec(), FD,
1448 DeclAccessPair::make(FD, FD->getAccess()),
1449 DeclarationNameInfo(FD->getDeclName(), Loc));
1450 if (E.isInvalid())
1451 return true;
1452
1453 // If the type of the member is T, the referenced type is cv T, where cv is
1454 // the cv-qualification of the decomposition expression.
1455 //
1456 // FIXME: We resolve a defect here: if the field is mutable, we do not add
1457 // 'const' to the type of the field.
1458 Qualifiers Q = DecompType.getQualifiers();
1459 if (FD->isMutable())
1460 Q.removeConst();
1461 B->setBinding(S.BuildQualifiedType(FD->getType(), Loc, Q), E.get());
1462 }
1463
1464 if (I != Bindings.size())
1465 return DiagnoseBadNumberOfBindings();
1466
1467 return false;
1468}
1469
1470void Sema::CheckCompleteDecompositionDeclaration(DecompositionDecl *DD) {
1471 QualType DecompType = DD->getType();
1472
1473 // If the type of the decomposition is dependent, then so is the type of
1474 // each binding.
1475 if (DecompType->isDependentType()) {
1476 for (auto *B : DD->bindings())
1477 B->setType(Context.DependentTy);
1478 return;
1479 }
1480
1481 DecompType = DecompType.getNonReferenceType();
1482 ArrayRef<BindingDecl*> Bindings = DD->bindings();
1483
1484 // C++1z [dcl.decomp]/2:
1485 // If E is an array type [...]
1486 // As an extension, we also support decomposition of built-in complex and
1487 // vector types.
1488 if (auto *CAT = Context.getAsConstantArrayType(DecompType)) {
1489 if (checkArrayDecomposition(*this, Bindings, DD, DecompType, CAT))
1490 DD->setInvalidDecl();
1491 return;
1492 }
1493 if (auto *VT = DecompType->getAs<VectorType>()) {
1494 if (checkVectorDecomposition(*this, Bindings, DD, DecompType, VT))
1495 DD->setInvalidDecl();
1496 return;
1497 }
1498 if (auto *CT = DecompType->getAs<ComplexType>()) {
1499 if (checkComplexDecomposition(*this, Bindings, DD, DecompType, CT))
1500 DD->setInvalidDecl();
1501 return;
1502 }
1503
1504 // C++1z [dcl.decomp]/3:
1505 // if the expression std::tuple_size<E>::value is a well-formed integral
1506 // constant expression, [...]
1507 llvm::APSInt TupleSize(32);
1508 switch (isTupleLike(*this, DD->getLocation(), DecompType, TupleSize)) {
1509 case IsTupleLike::Error:
1510 DD->setInvalidDecl();
1511 return;
1512
1513 case IsTupleLike::TupleLike:
1514 if (checkTupleLikeDecomposition(*this, Bindings, DD, DecompType, TupleSize))
1515 DD->setInvalidDecl();
1516 return;
1517
1518 case IsTupleLike::NotTupleLike:
1519 break;
1520 }
1521
1522 // C++1z [dcl.dcl]/8:
1523 // [E shall be of array or non-union class type]
1524 CXXRecordDecl *RD = DecompType->getAsCXXRecordDecl();
1525 if (!RD || RD->isUnion()) {
1526 Diag(DD->getLocation(), diag::err_decomp_decl_unbindable_type)
1527 << DD << !RD << DecompType;
1528 DD->setInvalidDecl();
1529 return;
1530 }
1531
1532 // C++1z [dcl.decomp]/4:
1533 // all of E's non-static data members shall be [...] direct members of
1534 // E or of the same unambiguous public base class of E, ...
1535 if (checkMemberDecomposition(*this, Bindings, DD, DecompType, RD))
1536 DD->setInvalidDecl();
1537}
1538
1539/// Merge the exception specifications of two variable declarations.
1540///
1541/// This is called when there's a redeclaration of a VarDecl. The function
1542/// checks if the redeclaration might have an exception specification and
1543/// validates compatibility and merges the specs if necessary.
1544void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) {
1545 // Shortcut if exceptions are disabled.
1546 if (!getLangOpts().CXXExceptions)
1547 return;
1548
1549 assert(Context.hasSameType(New->getType(), Old->getType()) &&((void)0)
1550 "Should only be called if types are otherwise the same.")((void)0);
1551
1552 QualType NewType = New->getType();
1553 QualType OldType = Old->getType();
1554
1555 // We're only interested in pointers and references to functions, as well
1556 // as pointers to member functions.
1557 if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
1558 NewType = R->getPointeeType();
1559 OldType = OldType->castAs<ReferenceType>()->getPointeeType();
1560 } else if (const PointerType *P = NewType->getAs<PointerType>()) {
1561 NewType = P->getPointeeType();
1562 OldType = OldType->castAs<PointerType>()->getPointeeType();
1563 } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
1564 NewType = M->getPointeeType();
1565 OldType = OldType->castAs<MemberPointerType>()->getPointeeType();
1566 }
1567
1568 if (!NewType->isFunctionProtoType())
1569 return;
1570
1571 // There's lots of special cases for functions. For function pointers, system
1572 // libraries are hopefully not as broken so that we don't need these
1573 // workarounds.
1574 if (CheckEquivalentExceptionSpec(
1575 OldType->getAs<FunctionProtoType>(), Old->getLocation(),
1576 NewType->getAs<FunctionProtoType>(), New->getLocation())) {
1577 New->setInvalidDecl();
1578 }
1579}
1580
1581/// CheckCXXDefaultArguments - Verify that the default arguments for a
1582/// function declaration are well-formed according to C++
1583/// [dcl.fct.default].
1584void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
1585 unsigned NumParams = FD->getNumParams();
1586 unsigned ParamIdx = 0;
1587
1588 // This checking doesn't make sense for explicit specializations; their
1589 // default arguments are determined by the declaration we're specializing,
1590 // not by FD.
1591 if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
1592 return;
1593 if (auto *FTD = FD->getDescribedFunctionTemplate())
1594 if (FTD->isMemberSpecialization())
1595 return;
1596
1597 // Find first parameter with a default argument
1598 for (; ParamIdx < NumParams; ++ParamIdx) {
1599 ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
1600 if (Param->hasDefaultArg())
1601 break;
1602 }
1603
1604 // C++20 [dcl.fct.default]p4:
1605 // In a given function declaration, each parameter subsequent to a parameter
1606 // with a default argument shall have a default argument supplied in this or
1607 // a previous declaration, unless the parameter was expanded from a
1608 // parameter pack, or shall be a function parameter pack.
1609 for (; ParamIdx < NumParams; ++ParamIdx) {
1610 ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
1611 if (!Param->hasDefaultArg() && !Param->isParameterPack() &&
1612 !(CurrentInstantiationScope &&
1613 CurrentInstantiationScope->isLocalPackExpansion(Param))) {
1614 if (Param->isInvalidDecl())
1615 /* We already complained about this parameter. */;
1616 else if (Param->getIdentifier())
1617 Diag(Param->getLocation(),
1618 diag::err_param_default_argument_missing_name)
1619 << Param->getIdentifier();
1620 else
1621 Diag(Param->getLocation(),
1622 diag::err_param_default_argument_missing);
1623 }
1624 }
1625}
1626
1627/// Check that the given type is a literal type. Issue a diagnostic if not,
1628/// if Kind is Diagnose.
1629/// \return \c true if a problem has been found (and optionally diagnosed).
1630template <typename... Ts>
1631static bool CheckLiteralType(Sema &SemaRef, Sema::CheckConstexprKind Kind,
1632 SourceLocation Loc, QualType T, unsigned DiagID,
1633 Ts &&...DiagArgs) {
1634 if (T->isDependentType())
1635 return false;
1636
1637 switch (Kind) {
1638 case Sema::CheckConstexprKind::Diagnose:
1639 return SemaRef.RequireLiteralType(Loc, T, DiagID,
1640 std::forward<Ts>(DiagArgs)...);
1641
1642 case Sema::CheckConstexprKind::CheckValid:
1643 return !T->isLiteralType(SemaRef.Context);
1644 }
1645
1646 llvm_unreachable("unknown CheckConstexprKind")__builtin_unreachable();
1647}
1648
1649/// Determine whether a destructor cannot be constexpr due to
1650static bool CheckConstexprDestructorSubobjects(Sema &SemaRef,
1651 const CXXDestructorDecl *DD,
1652 Sema::CheckConstexprKind Kind) {
1653 auto Check = [&](SourceLocation Loc, QualType T, const FieldDecl *FD) {
1654 const CXXRecordDecl *RD =
1655 T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
1656 if (!RD || RD->hasConstexprDestructor())
1657 return true;
1658
1659 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1660 SemaRef.Diag(DD->getLocation(), diag::err_constexpr_dtor_subobject)
1661 << static_cast<int>(DD->getConstexprKind()) << !FD
1662 << (FD ? FD->getDeclName() : DeclarationName()) << T;
1663 SemaRef.Diag(Loc, diag::note_constexpr_dtor_subobject)
1664 << !FD << (FD ? FD->getDeclName() : DeclarationName()) << T;
1665 }
1666 return false;
1667 };
1668
1669 const CXXRecordDecl *RD = DD->getParent();
1670 for (const CXXBaseSpecifier &B : RD->bases())
1671 if (!Check(B.getBaseTypeLoc(), B.getType(), nullptr))
1672 return false;
1673 for (const FieldDecl *FD : RD->fields())
1674 if (!Check(FD->getLocation(), FD->getType(), FD))
1675 return false;
1676 return true;
1677}
1678
1679/// Check whether a function's parameter types are all literal types. If so,
1680/// return true. If not, produce a suitable diagnostic and return false.
1681static bool CheckConstexprParameterTypes(Sema &SemaRef,
1682 const FunctionDecl *FD,
1683 Sema::CheckConstexprKind Kind) {
1684 unsigned ArgIndex = 0;
1685 const auto *FT = FD->getType()->castAs<FunctionProtoType>();
1686 for (FunctionProtoType::param_type_iterator i = FT->param_type_begin(),
1687 e = FT->param_type_end();
1688 i != e; ++i, ++ArgIndex) {
1689 const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
1690 SourceLocation ParamLoc = PD->getLocation();
1691 if (CheckLiteralType(SemaRef, Kind, ParamLoc, *i,
1692 diag::err_constexpr_non_literal_param, ArgIndex + 1,
1693 PD->getSourceRange(), isa<CXXConstructorDecl>(FD),
1694 FD->isConsteval()))
1695 return false;
1696 }
1697 return true;
1698}
1699
1700/// Check whether a function's return type is a literal type. If so, return
1701/// true. If not, produce a suitable diagnostic and return false.
1702static bool CheckConstexprReturnType(Sema &SemaRef, const FunctionDecl *FD,
1703 Sema::CheckConstexprKind Kind) {
1704 if (CheckLiteralType(SemaRef, Kind, FD->getLocation(), FD->getReturnType(),
1705 diag::err_constexpr_non_literal_return,
1706 FD->isConsteval()))
1707 return false;
1708 return true;
1709}
1710
1711/// Get diagnostic %select index for tag kind for
1712/// record diagnostic message.
1713/// WARNING: Indexes apply to particular diagnostics only!
1714///
1715/// \returns diagnostic %select index.
1716static unsigned getRecordDiagFromTagKind(TagTypeKind Tag) {
1717 switch (Tag) {
1718 case TTK_Struct: return 0;
1719 case TTK_Interface: return 1;
1720 case TTK_Class: return 2;
1721 default: llvm_unreachable("Invalid tag kind for record diagnostic!")__builtin_unreachable();
1722 }
1723}
1724
1725static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
1726 Stmt *Body,
1727 Sema::CheckConstexprKind Kind);
1728
1729// Check whether a function declaration satisfies the requirements of a
1730// constexpr function definition or a constexpr constructor definition. If so,
1731// return true. If not, produce appropriate diagnostics (unless asked not to by
1732// Kind) and return false.
1733//
1734// This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
1735bool Sema::CheckConstexprFunctionDefinition(const FunctionDecl *NewFD,
1736 CheckConstexprKind Kind) {
1737 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
1738 if (MD && MD->isInstance()) {
1739 // C++11 [dcl.constexpr]p4:
1740 // The definition of a constexpr constructor shall satisfy the following
1741 // constraints:
1742 // - the class shall not have any virtual base classes;
1743 //
1744 // FIXME: This only applies to constructors and destructors, not arbitrary
1745 // member functions.
1746 const CXXRecordDecl *RD = MD->getParent();
1747 if (RD->getNumVBases()) {
1748 if (Kind == CheckConstexprKind::CheckValid)
1749 return false;
1750
1751 Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
1752 << isa<CXXConstructorDecl>(NewFD)
1753 << getRecordDiagFromTagKind(RD->getTagKind()) << RD->getNumVBases();
1754 for (const auto &I : RD->vbases())
1755 Diag(I.getBeginLoc(), diag::note_constexpr_virtual_base_here)
1756 << I.getSourceRange();
1757 return false;
1758 }
1759 }
1760
1761 if (!isa<CXXConstructorDecl>(NewFD)) {
1762 // C++11 [dcl.constexpr]p3:
1763 // The definition of a constexpr function shall satisfy the following
1764 // constraints:
1765 // - it shall not be virtual; (removed in C++20)
1766 const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
1767 if (Method && Method->isVirtual()) {
1768 if (getLangOpts().CPlusPlus20) {
1769 if (Kind == CheckConstexprKind::Diagnose)
1770 Diag(Method->getLocation(), diag::warn_cxx17_compat_constexpr_virtual);
1771 } else {
1772 if (Kind == CheckConstexprKind::CheckValid)
1773 return false;
1774
1775 Method = Method->getCanonicalDecl();
1776 Diag(Method->getLocation(), diag::err_constexpr_virtual);
1777
1778 // If it's not obvious why this function is virtual, find an overridden
1779 // function which uses the 'virtual' keyword.
1780 const CXXMethodDecl *WrittenVirtual = Method;
1781 while (!WrittenVirtual->isVirtualAsWritten())
1782 WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
1783 if (WrittenVirtual != Method)
1784 Diag(WrittenVirtual->getLocation(),
1785 diag::note_overridden_virtual_function);
1786 return false;
1787 }
1788 }
1789
1790 // - its return type shall be a literal type;
1791 if (!CheckConstexprReturnType(*this, NewFD, Kind))
1792 return false;
1793 }
1794
1795 if (auto *Dtor = dyn_cast<CXXDestructorDecl>(NewFD)) {
1796 // A destructor can be constexpr only if the defaulted destructor could be;
1797 // we don't need to check the members and bases if we already know they all
1798 // have constexpr destructors.
1799 if (!Dtor->getParent()->defaultedDestructorIsConstexpr()) {
1800 if (Kind == CheckConstexprKind::CheckValid)
1801 return false;
1802 if (!CheckConstexprDestructorSubobjects(*this, Dtor, Kind))
1803 return false;
1804 }
1805 }
1806
1807 // - each of its parameter types shall be a literal type;
1808 if (!CheckConstexprParameterTypes(*this, NewFD, Kind))
1809 return false;
1810
1811 Stmt *Body = NewFD->getBody();
1812 assert(Body &&((void)0)
1813 "CheckConstexprFunctionDefinition called on function with no body")((void)0);
1814 return CheckConstexprFunctionBody(*this, NewFD, Body, Kind);
1815}
1816
1817/// Check the given declaration statement is legal within a constexpr function
1818/// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3.
1819///
1820/// \return true if the body is OK (maybe only as an extension), false if we
1821/// have diagnosed a problem.
1822static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
1823 DeclStmt *DS, SourceLocation &Cxx1yLoc,
1824 Sema::CheckConstexprKind Kind) {
1825 // C++11 [dcl.constexpr]p3 and p4:
1826 // The definition of a constexpr function(p3) or constructor(p4) [...] shall
1827 // contain only
1828 for (const auto *DclIt : DS->decls()) {
1829 switch (DclIt->getKind()) {
1830 case Decl::StaticAssert:
1831 case Decl::Using:
1832 case Decl::UsingShadow:
1833 case Decl::UsingDirective:
1834 case Decl::UnresolvedUsingTypename:
1835 case Decl::UnresolvedUsingValue:
1836 case Decl::UsingEnum:
1837 // - static_assert-declarations
1838 // - using-declarations,
1839 // - using-directives,
1840 // - using-enum-declaration
1841 continue;
1842
1843 case Decl::Typedef:
1844 case Decl::TypeAlias: {
1845 // - typedef declarations and alias-declarations that do not define
1846 // classes or enumerations,
1847 const auto *TN = cast<TypedefNameDecl>(DclIt);
1848 if (TN->getUnderlyingType()->isVariablyModifiedType()) {
1849 // Don't allow variably-modified types in constexpr functions.
1850 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1851 TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
1852 SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
1853 << TL.getSourceRange() << TL.getType()
1854 << isa<CXXConstructorDecl>(Dcl);
1855 }
1856 return false;
1857 }
1858 continue;
1859 }
1860
1861 case Decl::Enum:
1862 case Decl::CXXRecord:
1863 // C++1y allows types to be defined, not just declared.
1864 if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition()) {
1865 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1866 SemaRef.Diag(DS->getBeginLoc(),
1867 SemaRef.getLangOpts().CPlusPlus14
1868 ? diag::warn_cxx11_compat_constexpr_type_definition
1869 : diag::ext_constexpr_type_definition)
1870 << isa<CXXConstructorDecl>(Dcl);
1871 } else if (!SemaRef.getLangOpts().CPlusPlus14) {
1872 return false;
1873 }
1874 }
1875 continue;
1876
1877 case Decl::EnumConstant:
1878 case Decl::IndirectField:
1879 case Decl::ParmVar:
1880 // These can only appear with other declarations which are banned in
1881 // C++11 and permitted in C++1y, so ignore them.
1882 continue;
1883
1884 case Decl::Var:
1885 case Decl::Decomposition: {
1886 // C++1y [dcl.constexpr]p3 allows anything except:
1887 // a definition of a variable of non-literal type or of static or
1888 // thread storage duration or [before C++2a] for which no
1889 // initialization is performed.
1890 const auto *VD = cast<VarDecl>(DclIt);
1891 if (VD->isThisDeclarationADefinition()) {
1892 if (VD->isStaticLocal()) {
1893 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1894 SemaRef.Diag(VD->getLocation(),
1895 diag::err_constexpr_local_var_static)
1896 << isa<CXXConstructorDecl>(Dcl)
1897 << (VD->getTLSKind() == VarDecl::TLS_Dynamic);
1898 }
1899 return false;
1900 }
1901 if (CheckLiteralType(SemaRef, Kind, VD->getLocation(), VD->getType(),
1902 diag::err_constexpr_local_var_non_literal_type,
1903 isa<CXXConstructorDecl>(Dcl)))
1904 return false;
1905 if (!VD->getType()->isDependentType() &&
1906 !VD->hasInit() && !VD->isCXXForRangeDecl()) {
1907 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1908 SemaRef.Diag(
1909 VD->getLocation(),
1910 SemaRef.getLangOpts().CPlusPlus20
1911 ? diag::warn_cxx17_compat_constexpr_local_var_no_init
1912 : diag::ext_constexpr_local_var_no_init)
1913 << isa<CXXConstructorDecl>(Dcl);
1914 } else if (!SemaRef.getLangOpts().CPlusPlus20) {
1915 return false;
1916 }
1917 continue;
1918 }
1919 }
1920 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1921 SemaRef.Diag(VD->getLocation(),
1922 SemaRef.getLangOpts().CPlusPlus14
1923 ? diag::warn_cxx11_compat_constexpr_local_var
1924 : diag::ext_constexpr_local_var)
1925 << isa<CXXConstructorDecl>(Dcl);
1926 } else if (!SemaRef.getLangOpts().CPlusPlus14) {
1927 return false;
1928 }
1929 continue;
1930 }
1931
1932 case Decl::NamespaceAlias:
1933 case Decl::Function:
1934 // These are disallowed in C++11 and permitted in C++1y. Allow them
1935 // everywhere as an extension.
1936 if (!Cxx1yLoc.isValid())
1937 Cxx1yLoc = DS->getBeginLoc();
1938 continue;
1939
1940 default:
1941 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1942 SemaRef.Diag(DS->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
1943 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
1944 }
1945 return false;
1946 }
1947 }
1948
1949 return true;
1950}
1951
1952/// Check that the given field is initialized within a constexpr constructor.
1953///
1954/// \param Dcl The constexpr constructor being checked.
1955/// \param Field The field being checked. This may be a member of an anonymous
1956/// struct or union nested within the class being checked.
1957/// \param Inits All declarations, including anonymous struct/union members and
1958/// indirect members, for which any initialization was provided.
1959/// \param Diagnosed Whether we've emitted the error message yet. Used to attach
1960/// multiple notes for different members to the same error.
1961/// \param Kind Whether we're diagnosing a constructor as written or determining
1962/// whether the formal requirements are satisfied.
1963/// \return \c false if we're checking for validity and the constructor does
1964/// not satisfy the requirements on a constexpr constructor.
1965static bool CheckConstexprCtorInitializer(Sema &SemaRef,
1966 const FunctionDecl *Dcl,
1967 FieldDecl *Field,
1968 llvm::SmallSet<Decl*, 16> &Inits,
1969 bool &Diagnosed,
1970 Sema::CheckConstexprKind Kind) {
1971 // In C++20 onwards, there's nothing to check for validity.
1972 if (Kind == Sema::CheckConstexprKind::CheckValid &&
1973 SemaRef.getLangOpts().CPlusPlus20)
1974 return true;
1975
1976 if (Field->isInvalidDecl())
1977 return true;
1978
1979 if (Field->isUnnamedBitfield())
1980 return true;
1981
1982 // Anonymous unions with no variant members and empty anonymous structs do not
1983 // need to be explicitly initialized. FIXME: Anonymous structs that contain no
1984 // indirect fields don't need initializing.
1985 if (Field->isAnonymousStructOrUnion() &&
1986 (Field->getType()->isUnionType()
1987 ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers()
1988 : Field->getType()->getAsCXXRecordDecl()->isEmpty()))
1989 return true;
1990
1991 if (!Inits.count(Field)) {
1992 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1993 if (!Diagnosed) {
1994 SemaRef.Diag(Dcl->getLocation(),
1995 SemaRef.getLangOpts().CPlusPlus20
1996 ? diag::warn_cxx17_compat_constexpr_ctor_missing_init
1997 : diag::ext_constexpr_ctor_missing_init);
1998 Diagnosed = true;
1999 }
2000 SemaRef.Diag(Field->getLocation(),
2001 diag::note_constexpr_ctor_missing_init);
2002 } else if (!SemaRef.getLangOpts().CPlusPlus20) {
2003 return false;
2004 }
2005 } else if (Field->isAnonymousStructOrUnion()) {
2006 const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
2007 for (auto *I : RD->fields())
2008 // If an anonymous union contains an anonymous struct of which any member
2009 // is initialized, all members must be initialized.
2010 if (!RD->isUnion() || Inits.count(I))
2011 if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
2012 Kind))
2013 return false;
2014 }
2015 return true;
2016}
2017
2018/// Check the provided statement is allowed in a constexpr function
2019/// definition.
2020static bool
2021CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S,
2022 SmallVectorImpl<SourceLocation> &ReturnStmts,
2023 SourceLocation &Cxx1yLoc, SourceLocation &Cxx2aLoc,
2024 Sema::CheckConstexprKind Kind) {
2025 // - its function-body shall be [...] a compound-statement that contains only
2026 switch (S->getStmtClass()) {
2027 case Stmt::NullStmtClass:
2028 // - null statements,
2029 return true;
2030
2031 case Stmt::DeclStmtClass:
2032 // - static_assert-declarations
2033 // - using-declarations,
2034 // - using-directives,
2035 // - typedef declarations and alias-declarations that do not define
2036 // classes or enumerations,
2037 if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc, Kind))
2038 return false;
2039 return true;
2040
2041 case Stmt::ReturnStmtClass:
2042 // - and exactly one return statement;
2043 if (isa<CXXConstructorDecl>(Dcl)) {
2044 // C++1y allows return statements in constexpr constructors.
2045 if (!Cxx1yLoc.isValid())
2046 Cxx1yLoc = S->getBeginLoc();
2047 return true;
2048 }
2049
2050 ReturnStmts.push_back(S->getBeginLoc());
2051 return true;
2052
2053 case Stmt::CompoundStmtClass: {
2054 // C++1y allows compound-statements.
2055 if (!Cxx1yLoc.isValid())
2056 Cxx1yLoc = S->getBeginLoc();
2057
2058 CompoundStmt *CompStmt = cast<CompoundStmt>(S);
2059 for (auto *BodyIt : CompStmt->body()) {
2060 if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
2061 Cxx1yLoc, Cxx2aLoc, Kind))
2062 return false;
2063 }
2064 return true;
2065 }
2066
2067 case Stmt::AttributedStmtClass:
2068 if (!Cxx1yLoc.isValid())
2069 Cxx1yLoc = S->getBeginLoc();
2070 return true;
2071
2072 case Stmt::IfStmtClass: {
2073 // C++1y allows if-statements.
2074 if (!Cxx1yLoc.isValid())
2075 Cxx1yLoc = S->getBeginLoc();
2076
2077 IfStmt *If = cast<IfStmt>(S);
2078 if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts,
2079 Cxx1yLoc, Cxx2aLoc, Kind))
2080 return false;
2081 if (If->getElse() &&
2082 !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts,
2083 Cxx1yLoc, Cxx2aLoc, Kind))
2084 return false;
2085 return true;
2086 }
2087
2088 case Stmt::WhileStmtClass:
2089 case Stmt::DoStmtClass:
2090 case Stmt::ForStmtClass:
2091 case Stmt::CXXForRangeStmtClass:
2092 case Stmt::ContinueStmtClass:
2093 // C++1y allows all of these. We don't allow them as extensions in C++11,
2094 // because they don't make sense without variable mutation.
2095 if (!SemaRef.getLangOpts().CPlusPlus14)
2096 break;
2097 if (!Cxx1yLoc.isValid())
2098 Cxx1yLoc = S->getBeginLoc();
2099 for (Stmt *SubStmt : S->children())
2100 if (SubStmt &&
2101 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2102 Cxx1yLoc, Cxx2aLoc, Kind))
2103 return false;
2104 return true;
2105
2106 case Stmt::SwitchStmtClass:
2107 case Stmt::CaseStmtClass:
2108 case Stmt::DefaultStmtClass:
2109 case Stmt::BreakStmtClass:
2110 // C++1y allows switch-statements, and since they don't need variable
2111 // mutation, we can reasonably allow them in C++11 as an extension.
2112 if (!Cxx1yLoc.isValid())
2113 Cxx1yLoc = S->getBeginLoc();
2114 for (Stmt *SubStmt : S->children())
2115 if (SubStmt &&
2116 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2117 Cxx1yLoc, Cxx2aLoc, Kind))
2118 return false;
2119 return true;
2120
2121 case Stmt::GCCAsmStmtClass:
2122 case Stmt::MSAsmStmtClass:
2123 // C++2a allows inline assembly statements.
2124 case Stmt::CXXTryStmtClass:
2125 if (Cxx2aLoc.isInvalid())
2126 Cxx2aLoc = S->getBeginLoc();
2127 for (Stmt *SubStmt : S->children()) {
2128 if (SubStmt &&
2129 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2130 Cxx1yLoc, Cxx2aLoc, Kind))
2131 return false;
2132 }
2133 return true;
2134
2135 case Stmt::CXXCatchStmtClass:
2136 // Do not bother checking the language mode (already covered by the
2137 // try block check).
2138 if (!CheckConstexprFunctionStmt(SemaRef, Dcl,
2139 cast<CXXCatchStmt>(S)->getHandlerBlock(),
2140 ReturnStmts, Cxx1yLoc, Cxx2aLoc, Kind))
2141 return false;
2142 return true;
2143
2144 default:
2145 if (!isa<Expr>(S))
2146 break;
2147
2148 // C++1y allows expression-statements.
2149 if (!Cxx1yLoc.isValid())
2150 Cxx1yLoc = S->getBeginLoc();
2151 return true;
2152 }
2153
2154 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2155 SemaRef.Diag(S->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
2156 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
2157 }
2158 return false;
2159}
2160
2161/// Check the body for the given constexpr function declaration only contains
2162/// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
2163///
2164/// \return true if the body is OK, false if we have found or diagnosed a
2165/// problem.
2166static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
2167 Stmt *Body,
2168 Sema::CheckConstexprKind Kind) {
2169 SmallVector<SourceLocation, 4> ReturnStmts;
2170
2171 if (isa<CXXTryStmt>(Body)) {
2172 // C++11 [dcl.constexpr]p3:
2173 // The definition of a constexpr function shall satisfy the following
2174 // constraints: [...]
2175 // - its function-body shall be = delete, = default, or a
2176 // compound-statement
2177 //
2178 // C++11 [dcl.constexpr]p4:
2179 // In the definition of a constexpr constructor, [...]
2180 // - its function-body shall not be a function-try-block;
2181 //
2182 // This restriction is lifted in C++2a, as long as inner statements also
2183 // apply the general constexpr rules.
2184 switch (Kind) {
2185 case Sema::CheckConstexprKind::CheckValid:
2186 if (!SemaRef.getLangOpts().CPlusPlus20)
2187 return false;
2188 break;
2189
2190 case Sema::CheckConstexprKind::Diagnose:
2191 SemaRef.Diag(Body->getBeginLoc(),
2192 !SemaRef.getLangOpts().CPlusPlus20
2193 ? diag::ext_constexpr_function_try_block_cxx20
2194 : diag::warn_cxx17_compat_constexpr_function_try_block)
2195 << isa<CXXConstructorDecl>(Dcl);
2196 break;
2197 }
2198 }
2199
2200 // - its function-body shall be [...] a compound-statement that contains only
2201 // [... list of cases ...]
2202 //
2203 // Note that walking the children here is enough to properly check for
2204 // CompoundStmt and CXXTryStmt body.
2205 SourceLocation Cxx1yLoc, Cxx2aLoc;
2206 for (Stmt *SubStmt : Body->children()) {
2207 if (SubStmt &&
2208 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2209 Cxx1yLoc, Cxx2aLoc, Kind))
2210 return false;
2211 }
2212
2213 if (Kind == Sema::CheckConstexprKind::CheckValid) {
2214 // If this is only valid as an extension, report that we don't satisfy the
2215 // constraints of the current language.
2216 if ((Cxx2aLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus20) ||
2217 (Cxx1yLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus17))
2218 return false;
2219 } else if (Cxx2aLoc.isValid()) {
2220 SemaRef.Diag(Cxx2aLoc,
2221 SemaRef.getLangOpts().CPlusPlus20
2222 ? diag::warn_cxx17_compat_constexpr_body_invalid_stmt
2223 : diag::ext_constexpr_body_invalid_stmt_cxx20)
2224 << isa<CXXConstructorDecl>(Dcl);
2225 } else if (Cxx1yLoc.isValid()) {
2226 SemaRef.Diag(Cxx1yLoc,
2227 SemaRef.getLangOpts().CPlusPlus14
2228 ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt
2229 : diag::ext_constexpr_body_invalid_stmt)
2230 << isa<CXXConstructorDecl>(Dcl);
2231 }
2232
2233 if (const CXXConstructorDecl *Constructor
2234 = dyn_cast<CXXConstructorDecl>(Dcl)) {
2235 const CXXRecordDecl *RD = Constructor->getParent();
2236 // DR1359:
2237 // - every non-variant non-static data member and base class sub-object
2238 // shall be initialized;
2239 // DR1460:
2240 // - if the class is a union having variant members, exactly one of them
2241 // shall be initialized;
2242 if (RD->isUnion()) {
2243 if (Constructor->getNumCtorInitializers() == 0 &&
2244 RD->hasVariantMembers()) {
2245 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2246 SemaRef.Diag(
2247 Dcl->getLocation(),
2248 SemaRef.getLangOpts().CPlusPlus20
2249 ? diag::warn_cxx17_compat_constexpr_union_ctor_no_init
2250 : diag::ext_constexpr_union_ctor_no_init);
2251 } else if (!SemaRef.getLangOpts().CPlusPlus20) {
2252 return false;
2253 }
2254 }
2255 } else if (!Constructor->isDependentContext() &&
2256 !Constructor->isDelegatingConstructor()) {
2257 assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases")((void)0);
2258
2259 // Skip detailed checking if we have enough initializers, and we would
2260 // allow at most one initializer per member.
2261 bool AnyAnonStructUnionMembers = false;
2262 unsigned Fields = 0;
2263 for (CXXRecordDecl::field_iterator I = RD->field_begin(),
2264 E = RD->field_end(); I != E; ++I, ++Fields) {
2265 if (I->isAnonymousStructOrUnion()) {
2266 AnyAnonStructUnionMembers = true;
2267 break;
2268 }
2269 }
2270 // DR1460:
2271 // - if the class is a union-like class, but is not a union, for each of
2272 // its anonymous union members having variant members, exactly one of
2273 // them shall be initialized;
2274 if (AnyAnonStructUnionMembers ||
2275 Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
2276 // Check initialization of non-static data members. Base classes are
2277 // always initialized so do not need to be checked. Dependent bases
2278 // might not have initializers in the member initializer list.
2279 llvm::SmallSet<Decl*, 16> Inits;
2280 for (const auto *I: Constructor->inits()) {
2281 if (FieldDecl *FD = I->getMember())
2282 Inits.insert(FD);
2283 else if (IndirectFieldDecl *ID = I->getIndirectMember())
2284 Inits.insert(ID->chain_begin(), ID->chain_end());
2285 }
2286
2287 bool Diagnosed = false;
2288 for (auto *I : RD->fields())
2289 if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
2290 Kind))
2291 return false;
2292 }
2293 }
2294 } else {
2295 if (ReturnStmts.empty()) {
2296 // C++1y doesn't require constexpr functions to contain a 'return'
2297 // statement. We still do, unless the return type might be void, because
2298 // otherwise if there's no return statement, the function cannot
2299 // be used in a core constant expression.
2300 bool OK = SemaRef.getLangOpts().CPlusPlus14 &&
2301 (Dcl->getReturnType()->isVoidType() ||
2302 Dcl->getReturnType()->isDependentType());
2303 switch (Kind) {
2304 case Sema::CheckConstexprKind::Diagnose:
2305 SemaRef.Diag(Dcl->getLocation(),
2306 OK ? diag::warn_cxx11_compat_constexpr_body_no_return
2307 : diag::err_constexpr_body_no_return)
2308 << Dcl->isConsteval();
2309 if (!OK)
2310 return false;
2311 break;
2312
2313 case Sema::CheckConstexprKind::CheckValid:
2314 // The formal requirements don't include this rule in C++14, even
2315 // though the "must be able to produce a constant expression" rules
2316 // still imply it in some cases.
2317 if (!SemaRef.getLangOpts().CPlusPlus14)
2318 return false;
2319 break;
2320 }
2321 } else if (ReturnStmts.size() > 1) {
2322 switch (Kind) {
2323 case Sema::CheckConstexprKind::Diagnose:
2324 SemaRef.Diag(
2325 ReturnStmts.back(),
2326 SemaRef.getLangOpts().CPlusPlus14
2327 ? diag::warn_cxx11_compat_constexpr_body_multiple_return
2328 : diag::ext_constexpr_body_multiple_return);
2329 for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
2330 SemaRef.Diag(ReturnStmts[I],
2331 diag::note_constexpr_body_previous_return);
2332 break;
2333
2334 case Sema::CheckConstexprKind::CheckValid:
2335 if (!SemaRef.getLangOpts().CPlusPlus14)
2336 return false;
2337 break;
2338 }
2339 }
2340 }
2341
2342 // C++11 [dcl.constexpr]p5:
2343 // if no function argument values exist such that the function invocation
2344 // substitution would produce a constant expression, the program is
2345 // ill-formed; no diagnostic required.
2346 // C++11 [dcl.constexpr]p3:
2347 // - every constructor call and implicit conversion used in initializing the
2348 // return value shall be one of those allowed in a constant expression.
2349 // C++11 [dcl.constexpr]p4:
2350 // - every constructor involved in initializing non-static data members and
2351 // base class sub-objects shall be a constexpr constructor.
2352 //
2353 // Note that this rule is distinct from the "requirements for a constexpr
2354 // function", so is not checked in CheckValid mode.
2355 SmallVector<PartialDiagnosticAt, 8> Diags;
2356 if (Kind == Sema::CheckConstexprKind::Diagnose &&
2357 !Expr::isPotentialConstantExpr(Dcl, Diags)) {
2358 SemaRef.Diag(Dcl->getLocation(),
2359 diag::ext_constexpr_function_never_constant_expr)
2360 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
2361 for (size_t I = 0, N = Diags.size(); I != N; ++I)
2362 SemaRef.Diag(Diags[I].first, Diags[I].second);
2363 // Don't return false here: we allow this for compatibility in
2364 // system headers.
2365 }
2366
2367 return true;
2368}
2369
2370/// Get the class that is directly named by the current context. This is the
2371/// class for which an unqualified-id in this scope could name a constructor
2372/// or destructor.
2373///
2374/// If the scope specifier denotes a class, this will be that class.
2375/// If the scope specifier is empty, this will be the class whose
2376/// member-specification we are currently within. Otherwise, there
2377/// is no such class.
2378CXXRecordDecl *Sema::getCurrentClass(Scope *, const CXXScopeSpec *SS) {
2379 assert(getLangOpts().CPlusPlus && "No class names in C!")((void)0);
2380
2381 if (SS && SS->isInvalid())
2382 return nullptr;
2383
2384 if (SS && SS->isNotEmpty()) {
2385 DeclContext *DC = computeDeclContext(*SS, true);
2386 return dyn_cast_or_null<CXXRecordDecl>(DC);
2387 }
2388
2389 return dyn_cast_or_null<CXXRecordDecl>(CurContext);
2390}
2391
2392/// isCurrentClassName - Determine whether the identifier II is the
2393/// name of the class type currently being defined. In the case of
2394/// nested classes, this will only return true if II is the name of
2395/// the innermost class.
2396bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *S,
2397 const CXXScopeSpec *SS) {
2398 CXXRecordDecl *CurDecl = getCurrentClass(S, SS);
2399 return CurDecl && &II == CurDecl->getIdentifier();
2400}
2401
2402/// Determine whether the identifier II is a typo for the name of
2403/// the class type currently being defined. If so, update it to the identifier
2404/// that should have been used.
2405bool Sema::isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS) {
2406 assert(getLangOpts().CPlusPlus && "No class names in C!")((void)0);
2407
2408 if (!getLangOpts().SpellChecking)
2409 return false;
2410
2411 CXXRecordDecl *CurDecl;
2412 if (SS && SS->isSet() && !SS->isInvalid()) {
2413 DeclContext *DC = computeDeclContext(*SS, true);
2414 CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
2415 } else
2416 CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
2417
2418 if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() &&
2419 3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName())
2420 < II->getLength()) {
2421 II = CurDecl->getIdentifier();
2422 return true;
2423 }
2424
2425 return false;
2426}
2427
2428/// Determine whether the given class is a base class of the given
2429/// class, including looking at dependent bases.
2430static bool findCircularInheritance(const CXXRecordDecl *Class,
2431 const CXXRecordDecl *Current) {
2432 SmallVector<const CXXRecordDecl*, 8> Queue;
2433
2434 Class = Class->getCanonicalDecl();
2435 while (true) {
2436 for (const auto &I : Current->bases()) {
2437 CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl();
2438 if (!Base)
2439 continue;
2440
2441 Base = Base->getDefinition();
2442 if (!Base)
2443 continue;
2444
2445 if (Base->getCanonicalDecl() == Class)
2446 return true;
2447
2448 Queue.push_back(Base);
2449 }
2450
2451 if (Queue.empty())
2452 return false;
2453
2454 Current = Queue.pop_back_val();
2455 }
2456
2457 return false;
2458}
2459
2460/// Check the validity of a C++ base class specifier.
2461///
2462/// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
2463/// and returns NULL otherwise.
2464CXXBaseSpecifier *
2465Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
2466 SourceRange SpecifierRange,
2467 bool Virtual, AccessSpecifier Access,
2468 TypeSourceInfo *TInfo,
2469 SourceLocation EllipsisLoc) {
2470 QualType BaseType = TInfo->getType();
2471 if (BaseType->containsErrors()) {
2472 // Already emitted a diagnostic when parsing the error type.
2473 return nullptr;
2474 }
2475 // C++ [class.union]p1:
2476 // A union shall not have base classes.
2477 if (Class->isUnion()) {
2478 Diag(Class->getLocation(), diag::err_base_clause_on_union)
2479 << SpecifierRange;
2480 return nullptr;
2481 }
2482
2483 if (EllipsisLoc.isValid() &&
2484 !TInfo->getType()->containsUnexpandedParameterPack()) {
2485 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
2486 << TInfo->getTypeLoc().getSourceRange();
2487 EllipsisLoc = SourceLocation();
2488 }
2489
2490 SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
2491
2492 if (BaseType->isDependentType()) {
2493 // Make sure that we don't have circular inheritance among our dependent
2494 // bases. For non-dependent bases, the check for completeness below handles
2495 // this.
2496 if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) {
2497 if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() ||
2498 ((BaseDecl = BaseDecl->getDefinition()) &&
2499 findCircularInheritance(Class, BaseDecl))) {
2500 Diag(BaseLoc, diag::err_circular_inheritance)
2501 << BaseType << Context.getTypeDeclType(Class);
2502
2503 if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl())
2504 Diag(BaseDecl->getLocation(), diag::note_previous_decl)
2505 << BaseType;
2506
2507 return nullptr;
2508 }
2509 }
2510
2511 // Make sure that we don't make an ill-formed AST where the type of the
2512 // Class is non-dependent and its attached base class specifier is an
2513 // dependent type, which violates invariants in many clang code paths (e.g.
2514 // constexpr evaluator). If this case happens (in errory-recovery mode), we
2515 // explicitly mark the Class decl invalid. The diagnostic was already
2516 // emitted.
2517 if (!Class->getTypeForDecl()->isDependentType())
2518 Class->setInvalidDecl();
2519 return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2520 Class->getTagKind() == TTK_Class,
2521 Access, TInfo, EllipsisLoc);
2522 }
2523
2524 // Base specifiers must be record types.
2525 if (!BaseType->isRecordType()) {
2526 Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
2527 return nullptr;
2528 }
2529
2530 // C++ [class.union]p1:
2531 // A union shall not be used as a base class.
2532 if (BaseType->isUnionType()) {
2533 Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
2534 return nullptr;
2535 }
2536
2537 // For the MS ABI, propagate DLL attributes to base class templates.
2538 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
2539 if (Attr *ClassAttr = getDLLAttr(Class)) {
2540 if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
2541 BaseType->getAsCXXRecordDecl())) {
2542 propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate,
2543 BaseLoc);
2544 }
2545 }
2546 }
2547
2548 // C++ [class.derived]p2:
2549 // The class-name in a base-specifier shall not be an incompletely
2550 // defined class.
2551 if (RequireCompleteType(BaseLoc, BaseType,
2552 diag::err_incomplete_base_class, SpecifierRange)) {
2553 Class->setInvalidDecl();
2554 return nullptr;
2555 }
2556
2557 // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
2558 RecordDecl *BaseDecl = BaseType->castAs<RecordType>()->getDecl();
2559 assert(BaseDecl && "Record type has no declaration")((void)0);
2560 BaseDecl = BaseDecl->getDefinition();
2561 assert(BaseDecl && "Base type is not incomplete, but has no definition")((void)0);
2562 CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
2563 assert(CXXBaseDecl && "Base type is not a C++ type")((void)0);
2564
2565 // Microsoft docs say:
2566 // "If a base-class has a code_seg attribute, derived classes must have the
2567 // same attribute."
2568 const auto *BaseCSA = CXXBaseDecl->getAttr<CodeSegAttr>();
2569 const auto *DerivedCSA = Class->getAttr<CodeSegAttr>();
2570 if ((DerivedCSA || BaseCSA) &&
2571 (!BaseCSA || !DerivedCSA || BaseCSA->getName() != DerivedCSA->getName())) {
2572 Diag(Class->getLocation(), diag::err_mismatched_code_seg_base);
2573 Diag(CXXBaseDecl->getLocation(), diag::note_base_class_specified_here)
2574 << CXXBaseDecl;
2575 return nullptr;
2576 }
2577
2578 // A class which contains a flexible array member is not suitable for use as a
2579 // base class:
2580 // - If the layout determines that a base comes before another base,
2581 // the flexible array member would index into the subsequent base.
2582 // - If the layout determines that base comes before the derived class,
2583 // the flexible array member would index into the derived class.
2584 if (CXXBaseDecl->hasFlexibleArrayMember()) {
2585 Diag(BaseLoc, diag::err_base_class_has_flexible_array_member)
2586 << CXXBaseDecl->getDeclName();
2587 return nullptr;
2588 }
2589
2590 // C++ [class]p3:
2591 // If a class is marked final and it appears as a base-type-specifier in
2592 // base-clause, the program is ill-formed.
2593 if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
2594 Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
2595 << CXXBaseDecl->getDeclName()
2596 << FA->isSpelledAsSealed();
2597 Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at)
2598 << CXXBaseDecl->getDeclName() << FA->getRange();
2599 return nullptr;
2600 }
2601
2602 if (BaseDecl->isInvalidDecl())
2603 Class->setInvalidDecl();
2604
2605 // Create the base specifier.
2606 return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2607 Class->getTagKind() == TTK_Class,
2608 Access, TInfo, EllipsisLoc);
2609}
2610
2611/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
2612/// one entry in the base class list of a class specifier, for
2613/// example:
2614/// class foo : public bar, virtual private baz {
2615/// 'public bar' and 'virtual private baz' are each base-specifiers.
2616BaseResult
2617Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
2618 ParsedAttributes &Attributes,
2619 bool Virtual, AccessSpecifier Access,
2620 ParsedType basetype, SourceLocation BaseLoc,
2621 SourceLocation EllipsisLoc) {
2622 if (!classdecl)
2623 return true;
2624
2625 AdjustDeclIfTemplate(classdecl);
2626 CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
2627 if (!Class)
2628 return true;
2629
2630 // We haven't yet attached the base specifiers.
2631 Class->setIsParsingBaseSpecifiers();
2632
2633 // We do not support any C++11 attributes on base-specifiers yet.
2634 // Diagnose any attributes we see.
2635 for (const ParsedAttr &AL : Attributes) {
2636 if (AL.isInvalid() || AL.getKind() == ParsedAttr::IgnoredAttribute)
2637 continue;
2638 Diag(AL.getLoc(), AL.getKind() == ParsedAttr::UnknownAttribute
2639 ? (unsigned)diag::warn_unknown_attribute_ignored
2640 : (unsigned)diag::err_base_specifier_attribute)
2641 << AL << AL.getRange();
2642 }
2643
2644 TypeSourceInfo *TInfo = nullptr;
2645 GetTypeFromParser(basetype, &TInfo);
2646
2647 if (EllipsisLoc.isInvalid() &&
2648 DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
2649 UPPC_BaseType))
2650 return true;
2651
2652 if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
2653 Virtual, Access, TInfo,
2654 EllipsisLoc))
2655 return BaseSpec;
2656 else
2657 Class->setInvalidDecl();
2658
2659 return true;
2660}
2661
2662/// Use small set to collect indirect bases. As this is only used
2663/// locally, there's no need to abstract the small size parameter.
2664typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet;
2665
2666/// Recursively add the bases of Type. Don't add Type itself.
2667static void
2668NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set,
2669 const QualType &Type)
2670{
2671 // Even though the incoming type is a base, it might not be
2672 // a class -- it could be a template parm, for instance.
2673 if (auto Rec = Type->getAs<RecordType>()) {
2674 auto Decl = Rec->getAsCXXRecordDecl();
2675
2676 // Iterate over its bases.
2677 for (const auto &BaseSpec : Decl->bases()) {
2678 QualType Base = Context.getCanonicalType(BaseSpec.getType())
2679 .getUnqualifiedType();
2680 if (Set.insert(Base).second)
2681 // If we've not already seen it, recurse.
2682 NoteIndirectBases(Context, Set, Base);
2683 }
2684 }
2685}
2686
2687/// Performs the actual work of attaching the given base class
2688/// specifiers to a C++ class.
2689bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class,
2690 MutableArrayRef<CXXBaseSpecifier *> Bases) {
2691 if (Bases.empty())
2692 return false;
2693
2694 // Used to keep track of which base types we have already seen, so
2695 // that we can properly diagnose redundant direct base types. Note
2696 // that the key is always the unqualified canonical type of the base
2697 // class.
2698 std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
2699
2700 // Used to track indirect bases so we can see if a direct base is
2701 // ambiguous.
2702 IndirectBaseSet IndirectBaseTypes;
2703
2704 // Copy non-redundant base specifiers into permanent storage.
2705 unsigned NumGoodBases = 0;
2706 bool Invalid = false;
2707 for (unsigned idx = 0; idx < Bases.size(); ++idx) {
2708 QualType NewBaseType
2709 = Context.getCanonicalType(Bases[idx]->getType());
2710 NewBaseType = NewBaseType.getLocalUnqualifiedType();
2711
2712 CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
2713 if (KnownBase) {
2714 // C++ [class.mi]p3:
2715 // A class shall not be specified as a direct base class of a
2716 // derived class more than once.
2717 Diag(Bases[idx]->getBeginLoc(), diag::err_duplicate_base_class)
2718 << KnownBase->getType() << Bases[idx]->getSourceRange();
2719
2720 // Delete the duplicate base class specifier; we're going to
2721 // overwrite its pointer later.
2722 Context.Deallocate(Bases[idx]);
2723
2724 Invalid = true;
2725 } else {
2726 // Okay, add this new base class.
2727 KnownBase = Bases[idx];
2728 Bases[NumGoodBases++] = Bases[idx];
2729
2730 // Note this base's direct & indirect bases, if there could be ambiguity.
2731 if (Bases.size() > 1)
2732 NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType);
2733
2734 if (const RecordType *Record = NewBaseType->getAs<RecordType>()) {
2735 const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
2736 if (Class->isInterface() &&
2737 (!RD->isInterfaceLike() ||
2738 KnownBase->getAccessSpecifier() != AS_public)) {
2739 // The Microsoft extension __interface does not permit bases that
2740 // are not themselves public interfaces.
2741 Diag(KnownBase->getBeginLoc(), diag::err_invalid_base_in_interface)
2742 << getRecordDiagFromTagKind(RD->getTagKind()) << RD
2743 << RD->getSourceRange();
2744 Invalid = true;
2745 }
2746 if (RD->hasAttr<WeakAttr>())
2747 Class->addAttr(WeakAttr::CreateImplicit(Context));
2748 }
2749 }
2750 }
2751
2752 // Attach the remaining base class specifiers to the derived class.
2753 Class->setBases(Bases.data(), NumGoodBases);
2754
2755 // Check that the only base classes that are duplicate are virtual.
2756 for (unsigned idx = 0; idx < NumGoodBases; ++idx) {
2757 // Check whether this direct base is inaccessible due to ambiguity.
2758 QualType BaseType = Bases[idx]->getType();
2759
2760 // Skip all dependent types in templates being used as base specifiers.
2761 // Checks below assume that the base specifier is a CXXRecord.
2762 if (BaseType->isDependentType())
2763 continue;
2764
2765 CanQualType CanonicalBase = Context.getCanonicalType(BaseType)
2766 .getUnqualifiedType();
2767
2768 if (IndirectBaseTypes.count(CanonicalBase)) {
2769 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2770 /*DetectVirtual=*/true);
2771 bool found
2772 = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths);
2773 assert(found)((void)0);
2774 (void)found;
2775
2776 if (Paths.isAmbiguous(CanonicalBase))
2777 Diag(Bases[idx]->getBeginLoc(), diag::warn_inaccessible_base_class)
2778 << BaseType << getAmbiguousPathsDisplayString(Paths)
2779 << Bases[idx]->getSourceRange();
2780 else
2781 assert(Bases[idx]->isVirtual())((void)0);
2782 }
2783
2784 // Delete the base class specifier, since its data has been copied
2785 // into the CXXRecordDecl.
2786 Context.Deallocate(Bases[idx]);
2787 }
2788
2789 return Invalid;
2790}
2791
2792/// ActOnBaseSpecifiers - Attach the given base specifiers to the
2793/// class, after checking whether there are any duplicate base
2794/// classes.
2795void Sema::ActOnBaseSpecifiers(Decl *ClassDecl,
2796 MutableArrayRef<CXXBaseSpecifier *> Bases) {
2797 if (!ClassDecl || Bases.empty())
2798 return;
2799
2800 AdjustDeclIfTemplate(ClassDecl);
2801 AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases);
2802}
2803
2804/// Determine whether the type \p Derived is a C++ class that is
2805/// derived from the type \p Base.
2806bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base) {
2807 if (!getLangOpts().CPlusPlus)
2808 return false;
2809
2810 CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2811 if (!DerivedRD)
2812 return false;
2813
2814 CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2815 if (!BaseRD)
2816 return false;
2817
2818 // If either the base or the derived type is invalid, don't try to
2819 // check whether one is derived from the other.
2820 if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
2821 return false;
2822
2823 // FIXME: In a modules build, do we need the entire path to be visible for us
2824 // to be able to use the inheritance relationship?
2825 if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2826 return false;
2827
2828 return DerivedRD->isDerivedFrom(BaseRD);
2829}
2830
2831/// Determine whether the type \p Derived is a C++ class that is
2832/// derived from the type \p Base.
2833bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base,
2834 CXXBasePaths &Paths) {
2835 if (!getLangOpts().CPlusPlus)
2836 return false;
2837
2838 CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2839 if (!DerivedRD)
2840 return false;
2841
2842 CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2843 if (!BaseRD)
2844 return false;
2845
2846 if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2847 return false;
2848
2849 return DerivedRD->isDerivedFrom(BaseRD, Paths);
2850}
2851
2852static void BuildBasePathArray(const CXXBasePath &Path,
2853 CXXCastPath &BasePathArray) {
2854 // We first go backward and check if we have a virtual base.
2855 // FIXME: It would be better if CXXBasePath had the base specifier for
2856 // the nearest virtual base.
2857 unsigned Start = 0;
2858 for (unsigned I = Path.size(); I != 0; --I) {
2859 if (Path[I - 1].Base->isVirtual()) {
2860 Start = I - 1;
2861 break;
2862 }
2863 }
2864
2865 // Now add all bases.
2866 for (unsigned I = Start, E = Path.size(); I != E; ++I)
2867 BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
2868}
2869
2870
2871void Sema::BuildBasePathArray(const CXXBasePaths &Paths,
2872 CXXCastPath &BasePathArray) {
2873 assert(BasePathArray.empty() && "Base path array must be empty!")((void)0);
2874 assert(Paths.isRecordingPaths() && "Must record paths!")((void)0);
2875 return ::BuildBasePathArray(Paths.front(), BasePathArray);
2876}
2877/// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
2878/// conversion (where Derived and Base are class types) is
2879/// well-formed, meaning that the conversion is unambiguous (and
2880/// that all of the base classes are accessible). Returns true
2881/// and emits a diagnostic if the code is ill-formed, returns false
2882/// otherwise. Loc is the location where this routine should point to
2883/// if there is an error, and Range is the source range to highlight
2884/// if there is an error.
2885///
2886/// If either InaccessibleBaseID or AmbiguousBaseConvID are 0, then the
2887/// diagnostic for the respective type of error will be suppressed, but the
2888/// check for ill-formed code will still be performed.
2889bool
2890Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
2891 unsigned InaccessibleBaseID,
2892 unsigned AmbiguousBaseConvID,
2893 SourceLocation Loc, SourceRange Range,
2894 DeclarationName Name,
2895 CXXCastPath *BasePath,
2896 bool IgnoreAccess) {
2897 // First, determine whether the path from Derived to Base is
2898 // ambiguous. This is slightly more expensive than checking whether
2899 // the Derived to Base conversion exists, because here we need to
2900 // explore multiple paths to determine if there is an ambiguity.
2901 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2902 /*DetectVirtual=*/false);
2903 bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2904 if (!DerivationOkay)
2905 return true;
2906
2907 const CXXBasePath *Path = nullptr;
2908 if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType()))
2909 Path = &Paths.front();
2910
2911 // For MSVC compatibility, check if Derived directly inherits from Base. Clang
2912 // warns about this hierarchy under -Winaccessible-base, but MSVC allows the
2913 // user to access such bases.
2914 if (!Path && getLangOpts().MSVCCompat) {
2915 for (const CXXBasePath &PossiblePath : Paths) {
2916 if (PossiblePath.size() == 1) {
2917 Path = &PossiblePath;
2918 if (AmbiguousBaseConvID)
2919 Diag(Loc, diag::ext_ms_ambiguous_direct_base)
2920 << Base << Derived << Range;
2921 break;
2922 }
2923 }
2924 }
2925
2926 if (Path) {
2927 if (!IgnoreAccess) {
2928 // Check that the base class can be accessed.
2929 switch (
2930 CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) {
2931 case AR_inaccessible:
2932 return true;
2933 case AR_accessible:
2934 case AR_dependent:
2935 case AR_delayed:
2936 break;
2937 }
2938 }
2939
2940 // Build a base path if necessary.
2941 if (BasePath)
2942 ::BuildBasePathArray(*Path, *BasePath);
2943 return false;
2944 }
2945
2946 if (AmbiguousBaseConvID) {
2947 // We know that the derived-to-base conversion is ambiguous, and
2948 // we're going to produce a diagnostic. Perform the derived-to-base
2949 // search just one more time to compute all of the possible paths so
2950 // that we can print them out. This is more expensive than any of
2951 // the previous derived-to-base checks we've done, but at this point
2952 // performance isn't as much of an issue.
2953 Paths.clear();
2954 Paths.setRecordingPaths(true);
2955 bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2956 assert(StillOkay && "Can only be used with a derived-to-base conversion")((void)0);
2957 (void)StillOkay;
2958
2959 // Build up a textual representation of the ambiguous paths, e.g.,
2960 // D -> B -> A, that will be used to illustrate the ambiguous
2961 // conversions in the diagnostic. We only print one of the paths
2962 // to each base class subobject.
2963 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2964
2965 Diag(Loc, AmbiguousBaseConvID)
2966 << Derived << Base << PathDisplayStr << Range << Name;
2967 }
2968 return true;
2969}
2970
2971bool
2972Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
2973 SourceLocation Loc, SourceRange Range,
2974 CXXCastPath *BasePath,
2975 bool IgnoreAccess) {
2976 return CheckDerivedToBaseConversion(
2977 Derived, Base, diag::err_upcast_to_inaccessible_base,
2978 diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(),
2979 BasePath, IgnoreAccess);
2980}
2981
2982
2983/// Builds a string representing ambiguous paths from a
2984/// specific derived class to different subobjects of the same base
2985/// class.
2986///
2987/// This function builds a string that can be used in error messages
2988/// to show the different paths that one can take through the
2989/// inheritance hierarchy to go from the derived class to different
2990/// subobjects of a base class. The result looks something like this:
2991/// @code
2992/// struct D -> struct B -> struct A
2993/// struct D -> struct C -> struct A
2994/// @endcode
2995std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
2996 std::string PathDisplayStr;
2997 std::set<unsigned> DisplayedPaths;
2998 for (CXXBasePaths::paths_iterator Path = Paths.begin();
2999 Path != Paths.end(); ++Path) {
3000 if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
3001 // We haven't displayed a path to this particular base
3002 // class subobject yet.
3003 PathDisplayStr += "\n ";
3004 PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
3005 for (CXXBasePath::const_iterator Element = Path->begin();
3006 Element != Path->end(); ++Element)
3007 PathDisplayStr += " -> " + Element->Base->getType().getAsString();
3008 }
3009 }
3010
3011 return PathDisplayStr;
3012}
3013
3014//===----------------------------------------------------------------------===//
3015// C++ class member Handling
3016//===----------------------------------------------------------------------===//
3017
3018/// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
3019bool Sema::ActOnAccessSpecifier(AccessSpecifier Access, SourceLocation ASLoc,
3020 SourceLocation ColonLoc,
3021 const ParsedAttributesView &Attrs) {
3022 assert(Access != AS_none && "Invalid kind for syntactic access specifier!")((void)0);
3023 AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
3024 ASLoc, ColonLoc);
3025 CurContext->addHiddenDecl(ASDecl);
3026 return ProcessAccessDeclAttributeList(ASDecl, Attrs);
3027}
3028
3029/// CheckOverrideControl - Check C++11 override control semantics.
3030void Sema::CheckOverrideControl(NamedDecl *D) {
3031 if (D->isInvalidDecl())
3032 return;
3033
3034 // We only care about "override" and "final" declarations.
3035 if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>())
3036 return;
3037
3038 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
3039
3040 // We can't check dependent instance methods.
3041 if (MD && MD->isInstance() &&
3042 (MD->getParent()->hasAnyDependentBases() ||
3043 MD->getType()->isDependentType()))
3044 return;
3045
3046 if (MD && !MD->isVirtual()) {
3047 // If we have a non-virtual method, check if if hides a virtual method.
3048 // (In that case, it's most likely the method has the wrong type.)
3049 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
3050 FindHiddenVirtualMethods(MD, OverloadedMethods);
3051
3052 if (!OverloadedMethods.empty()) {
3053 if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
3054 Diag(OA->getLocation(),
3055 diag::override_keyword_hides_virtual_member_function)
3056 << "override" << (OverloadedMethods.size() > 1);
3057 } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
3058 Diag(FA->getLocation(),
3059 diag::override_keyword_hides_virtual_member_function)
3060 << (FA->isSpelledAsSealed() ? "sealed" : "final")
3061 << (OverloadedMethods.size() > 1);
3062 }
3063 NoteHiddenVirtualMethods(MD, OverloadedMethods);
3064 MD->setInvalidDecl();
3065 return;
3066 }
3067 // Fall through into the general case diagnostic.
3068 // FIXME: We might want to attempt typo correction here.
3069 }
3070
3071 if (!MD || !MD->isVirtual()) {
3072 if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
3073 Diag(OA->getLocation(),
3074 diag::override_keyword_only_allowed_on_virtual_member_functions)
3075 << "override" << FixItHint::CreateRemoval(OA->getLocation());
3076 D->dropAttr<OverrideAttr>();
3077 }
3078 if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
3079 Diag(FA->getLocation(),
3080 diag::override_keyword_only_allowed_on_virtual_member_functions)
3081 << (FA->isSpelledAsSealed() ? "sealed" : "final")
3082 << FixItHint::CreateRemoval(FA->getLocation());
3083 D->dropAttr<FinalAttr>();
3084 }
3085 return;
3086 }
3087
3088 // C++11 [class.virtual]p5:
3089 // If a function is marked with the virt-specifier override and
3090 // does not override a member function of a base class, the program is
3091 // ill-formed.
3092 bool HasOverriddenMethods = MD->size_overridden_methods() != 0;
3093 if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
3094 Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
3095 << MD->getDeclName();
3096}
3097
3098void Sema::DiagnoseAbsenceOfOverrideControl(NamedDecl *D, bool Inconsistent) {
3099 if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>())
3100 return;
3101 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
3102 if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>())
3103 return;
3104
3105 SourceLocation Loc = MD->getLocation();
3106 SourceLocation SpellingLoc = Loc;
3107 if (getSourceManager().isMacroArgExpansion(Loc))
3108 SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).getBegin();
3109 SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc);
3110 if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc))
3111 return;
3112
3113 if (MD->size_overridden_methods() > 0) {
3114 auto EmitDiag = [&](unsigned DiagInconsistent, unsigned DiagSuggest) {
3115 unsigned DiagID =
3116 Inconsistent && !Diags.isIgnored(DiagInconsistent, MD->getLocation())
3117 ? DiagInconsistent
3118 : DiagSuggest;
3119 Diag(MD->getLocation(), DiagID) << MD->getDeclName();
3120 const CXXMethodDecl *OMD = *MD->begin_overridden_methods();
3121 Diag(OMD->getLocation(), diag::note_overridden_virtual_function);
3122 };
3123 if (isa<CXXDestructorDecl>(MD))
3124 EmitDiag(
3125 diag::warn_inconsistent_destructor_marked_not_override_overriding,
3126 diag::warn_suggest_destructor_marked_not_override_overriding);
3127 else
3128 EmitDiag(diag::warn_inconsistent_function_marked_not_override_overriding,
3129 diag::warn_suggest_function_marked_not_override_overriding);
3130 }
3131}
3132
3133/// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
3134/// function overrides a virtual member function marked 'final', according to
3135/// C++11 [class.virtual]p4.
3136bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
3137 const CXXMethodDecl *Old) {
3138 FinalAttr *FA = Old->getAttr<FinalAttr>();
3139 if (!FA)
3140 return false;
3141
3142 Diag(New->getLocation(), diag::err_final_function_overridden)
3143 << New->getDeclName()
3144 << FA->isSpelledAsSealed();
3145 Diag(Old->getLocation(), diag::note_overridden_virtual_function);
3146 return true;
3147}
3148
3149static bool InitializationHasSideEffects(const FieldDecl &FD) {
3150 const Type *T = FD.getType()->getBaseElementTypeUnsafe();
3151 // FIXME: Destruction of ObjC lifetime types has side-effects.
3152 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3153 return !RD->isCompleteDefinition() ||
3154 !RD->hasTrivialDefaultConstructor() ||
3155 !RD->hasTrivialDestructor();
3156 return false;
3157}
3158
3159static const ParsedAttr *getMSPropertyAttr(const ParsedAttributesView &list) {
3160 ParsedAttributesView::const_iterator Itr =
3161 llvm::find_if(list, [](const ParsedAttr &AL) {
3162 return AL.isDeclspecPropertyAttribute();
3163 });
3164 if (Itr != list.end())
3165 return &*Itr;
3166 return nullptr;
3167}
3168
3169// Check if there is a field shadowing.
3170void Sema::CheckShadowInheritedFields(const SourceLocation &Loc,
3171 DeclarationName FieldName,
3172 const CXXRecordDecl *RD,
3173 bool DeclIsField) {
3174 if (Diags.isIgnored(diag::warn_shadow_field, Loc))
3175 return;
3176
3177 // To record a shadowed field in a base
3178 std::map<CXXRecordDecl*, NamedDecl*> Bases;
3179 auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier,
3180 CXXBasePath &Path) {
3181 const auto Base = Specifier->getType()->getAsCXXRecordDecl();
3182 // Record an ambiguous path directly
3183 if (Bases.find(Base) != Bases.end())
3184 return true;
3185 for (const auto Field : Base->lookup(FieldName)) {
3186 if ((isa<FieldDecl>(Field) || isa<IndirectFieldDecl>(Field)) &&
3187 Field->getAccess() != AS_private) {
3188 assert(Field->getAccess() != AS_none)((void)0);
3189 assert(Bases.find(Base) == Bases.end())((void)0);
3190 Bases[Base] = Field;
3191 return true;
3192 }
3193 }
3194 return false;
3195 };
3196
3197 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3198 /*DetectVirtual=*/true);
3199 if (!RD->lookupInBases(FieldShadowed, Paths))
3200 return;
3201
3202 for (const auto &P : Paths) {
3203 auto Base = P.back().Base->getType()->getAsCXXRecordDecl();
3204 auto It = Bases.find(Base);
3205 // Skip duplicated bases
3206 if (It == Bases.end())
3207 continue;
3208 auto BaseField = It->second;
3209 assert(BaseField->getAccess() != AS_private)((void)0);
3210 if (AS_none !=
3211 CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) {
3212 Diag(Loc, diag::warn_shadow_field)
3213 << FieldName << RD << Base << DeclIsField;
3214 Diag(BaseField->getLocation(), diag::note_shadow_field);
3215 Bases.erase(It);
3216 }
3217 }
3218}
3219
3220/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
3221/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
3222/// bitfield width if there is one, 'InitExpr' specifies the initializer if
3223/// one has been parsed, and 'InitStyle' is set if an in-class initializer is
3224/// present (but parsing it has been deferred).
3225NamedDecl *
3226Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
3227 MultiTemplateParamsArg TemplateParameterLists,
3228 Expr *BW, const VirtSpecifiers &VS,
3229 InClassInitStyle InitStyle) {
3230 const DeclSpec &DS = D.getDeclSpec();
3231 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
3232 DeclarationName Name = NameInfo.getName();
3233 SourceLocation Loc = NameInfo.getLoc();
3234
3235 // For anonymous bitfields, the location should point to the type.
3236 if (Loc.isInvalid())
3237 Loc = D.getBeginLoc();
3238
3239 Expr *BitWidth = static_cast<Expr*>(BW);
3240
3241 assert(isa<CXXRecordDecl>(CurContext))((void)0);
3242 assert(!DS.isFriendSpecified())((void)0);
3243
3244 bool isFunc = D.isDeclarationOfFunction();
3245 const ParsedAttr *MSPropertyAttr =
3246 getMSPropertyAttr(D.getDeclSpec().getAttributes());
3247
3248 if (cast<CXXRecordDecl>(CurContext)->isInterface()) {
3249 // The Microsoft extension __interface only permits public member functions
3250 // and prohibits constructors, destructors, operators, non-public member
3251 // functions, static methods and data members.
3252 unsigned InvalidDecl;
3253 bool ShowDeclName = true;
3254 if (!isFunc &&
3255 (DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr))
3256 InvalidDecl = 0;
3257 else if (!isFunc)
3258 InvalidDecl = 1;
3259 else if (AS != AS_public)
3260 InvalidDecl = 2;
3261 else if (DS.getStorageClassSpec() == DeclSpec::SCS_static)
3262 InvalidDecl = 3;
3263 else switch (Name.getNameKind()) {
3264 case DeclarationName::CXXConstructorName:
3265 InvalidDecl = 4;
3266 ShowDeclName = false;
3267 break;
3268
3269 case DeclarationName::CXXDestructorName:
3270 InvalidDecl = 5;
3271 ShowDeclName = false;
3272 break;
3273
3274 case DeclarationName::CXXOperatorName:
3275 case DeclarationName::CXXConversionFunctionName:
3276 InvalidDecl = 6;
3277 break;
3278
3279 default:
3280 InvalidDecl = 0;
3281 break;
3282 }
3283
3284 if (InvalidDecl) {
3285 if (ShowDeclName)
3286 Diag(Loc, diag::err_invalid_member_in_interface)
3287 << (InvalidDecl-1) << Name;
3288 else
3289 Diag(Loc, diag::err_invalid_member_in_interface)
3290 << (InvalidDecl-1) << "";
3291 return nullptr;
3292 }
3293 }
3294
3295 // C++ 9.2p6: A member shall not be declared to have automatic storage
3296 // duration (auto, register) or with the extern storage-class-specifier.
3297 // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
3298 // data members and cannot be applied to names declared const or static,
3299 // and cannot be applied to reference members.
3300 switch (DS.getStorageClassSpec()) {
3301 case DeclSpec::SCS_unspecified:
3302 case DeclSpec::SCS_typedef:
3303 case DeclSpec::SCS_static:
3304 break;
3305 case DeclSpec::SCS_mutable:
3306 if (isFunc) {
3307 Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
3308
3309 // FIXME: It would be nicer if the keyword was ignored only for this
3310 // declarator. Otherwise we could get follow-up errors.
3311 D.getMutableDeclSpec().ClearStorageClassSpecs();
3312 }
3313 break;
3314 default:
3315 Diag(DS.getStorageClassSpecLoc(),
3316 diag::err_storageclass_invalid_for_member);
3317 D.getMutableDeclSpec().ClearStorageClassSpecs();
3318 break;
3319 }
3320
3321 bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
3322 DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
3323 !isFunc);
3324
3325 if (DS.hasConstexprSpecifier() && isInstField) {
3326 SemaDiagnosticBuilder B =
3327 Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member);
3328 SourceLocation ConstexprLoc = DS.getConstexprSpecLoc();
3329 if (InitStyle == ICIS_NoInit) {
3330 B << 0 << 0;
3331 if (D.getDeclSpec().getTypeQualifiers() & DeclSpec::TQ_const)
3332 B << FixItHint::CreateRemoval(ConstexprLoc);
3333 else {
3334 B << FixItHint::CreateReplacement(ConstexprLoc, "const");
3335 D.getMutableDeclSpec().ClearConstexprSpec();
3336 const char *PrevSpec;
3337 unsigned DiagID;
3338 bool Failed = D.getMutableDeclSpec().SetTypeQual(
3339 DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts());
3340 (void)Failed;
3341 assert(!Failed && "Making a constexpr member const shouldn't fail")((void)0);
3342 }
3343 } else {
3344 B << 1;
3345 const char *PrevSpec;
3346 unsigned DiagID;
3347 if (D.getMutableDeclSpec().SetStorageClassSpec(
3348 *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID,
3349 Context.getPrintingPolicy())) {
3350 assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable &&((void)0)
3351 "This is the only DeclSpec that should fail to be applied")((void)0);
3352 B << 1;
3353 } else {
3354 B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static ");
3355 isInstField = false;
3356 }
3357 }
3358 }
3359
3360 NamedDecl *Member;
3361 if (isInstField) {
3362 CXXScopeSpec &SS = D.getCXXScopeSpec();
3363
3364 // Data members must have identifiers for names.
3365 if (!Name.isIdentifier()) {
3366 Diag(Loc, diag::err_bad_variable_name)
3367 << Name;
3368 return nullptr;
3369 }
3370
3371 IdentifierInfo *II = Name.getAsIdentifierInfo();
3372
3373 // Member field could not be with "template" keyword.
3374 // So TemplateParameterLists should be empty in this case.
3375 if (TemplateParameterLists.size()) {
3376 TemplateParameterList* TemplateParams = TemplateParameterLists[0];
3377 if (TemplateParams->size()) {
3378 // There is no such thing as a member field template.
3379 Diag(D.getIdentifierLoc(), diag::err_template_member)
3380 << II
3381 << SourceRange(TemplateParams->getTemplateLoc(),
3382 TemplateParams->getRAngleLoc());
3383 } else {
3384 // There is an extraneous 'template<>' for this member.
3385 Diag(TemplateParams->getTemplateLoc(),
3386 diag::err_template_member_noparams)
3387 << II
3388 << SourceRange(TemplateParams->getTemplateLoc(),
3389 TemplateParams->getRAngleLoc());
3390 }
3391 return nullptr;
3392 }
3393
3394 if (SS.isSet() && !SS.isInvalid()) {
3395 // The user provided a superfluous scope specifier inside a class
3396 // definition:
3397 //
3398 // class X {
3399 // int X::member;
3400 // };
3401 if (DeclContext *DC = computeDeclContext(SS, false))
3402 diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(),
3403 D.getName().getKind() ==
3404 UnqualifiedIdKind::IK_TemplateId);
3405 else
3406 Diag(D.getIdentifierLoc(), diag::err_member_qualification)
3407 << Name << SS.getRange();
3408
3409 SS.clear();
3410 }
3411
3412 if (MSPropertyAttr) {
3413 Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3414 BitWidth, InitStyle, AS, *MSPropertyAttr);
3415 if (!Member)
3416 return nullptr;
3417 isInstField = false;
3418 } else {
3419 Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3420 BitWidth, InitStyle, AS);
3421 if (!Member)
3422 return nullptr;
3423 }
3424
3425 CheckShadowInheritedFields(Loc, Name, cast<CXXRecordDecl>(CurContext));
3426 } else {
3427 Member = HandleDeclarator(S, D, TemplateParameterLists);
3428 if (!Member)
3429 return nullptr;
3430
3431 // Non-instance-fields can't have a bitfield.
3432 if (BitWidth) {
3433 if (Member->isInvalidDecl()) {
3434 // don't emit another diagnostic.
3435 } else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) {
3436 // C++ 9.6p3: A bit-field shall not be a static member.
3437 // "static member 'A' cannot be a bit-field"
3438 Diag(Loc, diag::err_static_not_bitfield)
3439 << Name << BitWidth->getSourceRange();
3440 } else if (isa<TypedefDecl>(Member)) {
3441 // "typedef member 'x' cannot be a bit-field"
3442 Diag(Loc, diag::err_typedef_not_bitfield)
3443 << Name << BitWidth->getSourceRange();
3444 } else {
3445 // A function typedef ("typedef int f(); f a;").
3446 // C++ 9.6p3: A bit-field shall have integral or enumeration type.
3447 Diag(Loc, diag::err_not_integral_type_bitfield)
3448 << Name << cast<ValueDecl>(Member)->getType()
3449 << BitWidth->getSourceRange();
3450 }
3451
3452 BitWidth = nullptr;
3453 Member->setInvalidDecl();
3454 }
3455
3456 NamedDecl *NonTemplateMember = Member;
3457 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
3458 NonTemplateMember = FunTmpl->getTemplatedDecl();
3459 else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member))
3460 NonTemplateMember = VarTmpl->getTemplatedDecl();
3461
3462 Member->setAccess(AS);
3463
3464 // If we have declared a member function template or static data member
3465 // template, set the access of the templated declaration as well.
3466 if (NonTemplateMember != Member)
3467 NonTemplateMember->setAccess(AS);
3468
3469 // C++ [temp.deduct.guide]p3:
3470 // A deduction guide [...] for a member class template [shall be
3471 // declared] with the same access [as the template].
3472 if (auto *DG = dyn_cast<CXXDeductionGuideDecl>(NonTemplateMember)) {
3473 auto *TD = DG->getDeducedTemplate();
3474 // Access specifiers are only meaningful if both the template and the
3475 // deduction guide are from the same scope.
3476 if (AS != TD->getAccess() &&
3477 TD->getDeclContext()->getRedeclContext()->Equals(
3478 DG->getDeclContext()->getRedeclContext())) {
3479 Diag(DG->getBeginLoc(), diag::err_deduction_guide_wrong_access);
3480 Diag(TD->getBeginLoc(), diag::note_deduction_guide_template_access)
3481 << TD->getAccess();
3482 const AccessSpecDecl *LastAccessSpec = nullptr;
3483 for (const auto *D : cast<CXXRecordDecl>(CurContext)->decls()) {
3484 if (const auto *AccessSpec = dyn_cast<AccessSpecDecl>(D))
3485 LastAccessSpec = AccessSpec;
3486 }
3487 assert(LastAccessSpec && "differing access with no access specifier")((void)0);
3488 Diag(LastAccessSpec->getBeginLoc(), diag::note_deduction_guide_access)
3489 << AS;
3490 }
3491 }
3492 }
3493
3494 if (VS.isOverrideSpecified())
3495 Member->addAttr(OverrideAttr::Create(Context, VS.getOverrideLoc(),
3496 AttributeCommonInfo::AS_Keyword));
3497 if (VS.isFinalSpecified())
3498 Member->addAttr(FinalAttr::Create(
3499 Context, VS.getFinalLoc(), AttributeCommonInfo::AS_Keyword,
3500 static_cast<FinalAttr::Spelling>(VS.isFinalSpelledSealed())));
3501
3502 if (VS.getLastLocation().isValid()) {
3503 // Update the end location of a method that has a virt-specifiers.
3504 if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
3505 MD->setRangeEnd(VS.getLastLocation());
3506 }
3507
3508 CheckOverrideControl(Member);
3509
3510 assert((Name || isInstField) && "No identifier for non-field ?")((void)0);
3511
3512 if (isInstField) {
3513 FieldDecl *FD = cast<FieldDecl>(Member);
3514 FieldCollector->Add(FD);
3515
3516 if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) {
3517 // Remember all explicit private FieldDecls that have a name, no side
3518 // effects and are not part of a dependent type declaration.
3519 if (!FD->isImplicit() && FD->getDeclName() &&
3520 FD->getAccess() == AS_private &&
3521 !FD->hasAttr<UnusedAttr>() &&
3522 !FD->getParent()->isDependentContext() &&
3523 !InitializationHasSideEffects(*FD))
3524 UnusedPrivateFields.insert(FD);
3525 }
3526 }
3527
3528 return Member;
3529}
3530
3531namespace {
3532 class UninitializedFieldVisitor
3533 : public EvaluatedExprVisitor<UninitializedFieldVisitor> {
3534 Sema &S;
3535 // List of Decls to generate a warning on. Also remove Decls that become
3536 // initialized.
3537 llvm::SmallPtrSetImpl<ValueDecl*> &Decls;
3538 // List of base classes of the record. Classes are removed after their
3539 // initializers.
3540 llvm::SmallPtrSetImpl<QualType> &BaseClasses;
3541 // Vector of decls to be removed from the Decl set prior to visiting the
3542 // nodes. These Decls may have been initialized in the prior initializer.
3543 llvm::SmallVector<ValueDecl*, 4> DeclsToRemove;
3544 // If non-null, add a note to the warning pointing back to the constructor.
3545 const CXXConstructorDecl *Constructor;
3546 // Variables to hold state when processing an initializer list. When
3547 // InitList is true, special case initialization of FieldDecls matching
3548 // InitListFieldDecl.
3549 bool InitList;
3550 FieldDecl *InitListFieldDecl;
3551 llvm::SmallVector<unsigned, 4> InitFieldIndex;
3552
3553 public:
3554 typedef EvaluatedExprVisitor<UninitializedFieldVisitor> Inherited;
3555 UninitializedFieldVisitor(Sema &S,
3556 llvm::SmallPtrSetImpl<ValueDecl*> &Decls,
3557 llvm::SmallPtrSetImpl<QualType> &BaseClasses)
3558 : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses),
3559 Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {}
3560
3561 // Returns true if the use of ME is not an uninitialized use.
3562 bool IsInitListMemberExprInitialized(MemberExpr *ME,
3563 bool CheckReferenceOnly) {
3564 llvm::SmallVector<FieldDecl*, 4> Fields;
3565 bool ReferenceField = false;
3566 while (ME) {
3567 FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
3568 if (!FD)
3569 return false;
3570 Fields.push_back(FD);
3571 if (FD->getType()->isReferenceType())
3572 ReferenceField = true;
3573 ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts());
3574 }
3575
3576 // Binding a reference to an uninitialized field is not an
3577 // uninitialized use.
3578 if (CheckReferenceOnly && !ReferenceField)
3579 return true;
3580
3581 llvm::SmallVector<unsigned, 4> UsedFieldIndex;
3582 // Discard the first field since it is the field decl that is being
3583 // initialized.
3584 for (auto I = Fields.rbegin() + 1, E = Fields.rend(); I != E; ++I) {
3585 UsedFieldIndex.push_back((*I)->getFieldIndex());
3586 }
3587
3588 for (auto UsedIter = UsedFieldIndex.begin(),
3589 UsedEnd = UsedFieldIndex.end(),
3590 OrigIter = InitFieldIndex.begin(),
3591 OrigEnd = InitFieldIndex.end();
3592 UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
3593 if (*UsedIter < *OrigIter)
3594 return true;
3595 if (*UsedIter > *OrigIter)
3596 break;
3597 }
3598
3599 return false;
3600 }
3601
3602 void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
3603 bool AddressOf) {
3604 if (isa<EnumConstantDecl>(ME->getMemberDecl()))
3605 return;
3606
3607 // FieldME is the inner-most MemberExpr that is not an anonymous struct
3608 // or union.
3609 MemberExpr *FieldME = ME;
3610
3611 bool AllPODFields = FieldME->getType().isPODType(S.Context);
3612
3613 Expr *Base = ME;
3614 while (MemberExpr *SubME =
3615 dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) {
3616
3617 if (isa<VarDecl>(SubME->getMemberDecl()))
3618 return;
3619
3620 if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
3621 if (!FD->isAnonymousStructOrUnion())
3622 FieldME = SubME;
3623
3624 if (!FieldME->getType().isPODType(S.Context))
3625 AllPODFields = false;
3626
3627 Base = SubME->getBase();
3628 }
3629
3630 if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts())) {
3631 Visit(Base);
3632 return;
3633 }
3634
3635 if (AddressOf && AllPODFields)
3636 return;
3637
3638 ValueDecl* FoundVD = FieldME->getMemberDecl();
3639
3640 if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
3641 while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {
3642 BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr());
3643 }
3644
3645 if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) {
3646 QualType T = BaseCast->getType();
3647 if (T->isPointerType() &&
3648 BaseClasses.count(T->getPointeeType())) {
3649 S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit)
3650 << T->getPointeeType() << FoundVD;
3651 }
3652 }
3653 }
3654
3655 if (!Decls.count(FoundVD))
3656 return;
3657
3658 const bool IsReference = FoundVD->getType()->isReferenceType();
3659
3660 if (InitList && !AddressOf && FoundVD == InitListFieldDecl) {
3661 // Special checking for initializer lists.
3662 if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) {
3663 return;
3664 }
3665 } else {
3666 // Prevent double warnings on use of unbounded references.
3667 if (CheckReferenceOnly && !IsReference)
3668 return;
3669 }
3670
3671 unsigned diag = IsReference
3672 ? diag::warn_reference_field_is_uninit
3673 : diag::warn_field_is_uninit;
3674 S.Diag(FieldME->getExprLoc(), diag) << FoundVD;
3675 if (Constructor)
3676 S.Diag(Constructor->getLocation(),
3677 diag::note_uninit_in_this_constructor)
3678 << (Constructor->isDefaultConstructor() && Constructor->isImplicit());
3679
3680 }
3681
3682 void HandleValue(Expr *E, bool AddressOf) {
3683 E = E->IgnoreParens();
3684
3685 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
3686 HandleMemberExpr(ME, false /*CheckReferenceOnly*/,
3687 AddressOf /*AddressOf*/);
3688 return;
3689 }
3690
3691 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
3692 Visit(CO->getCond());
3693 HandleValue(CO->getTrueExpr(), AddressOf);
3694 HandleValue(CO->getFalseExpr(), AddressOf);
3695 return;
3696 }
3697
3698 if (BinaryConditionalOperator *BCO =
3699 dyn_cast<BinaryConditionalOperator>(E)) {
3700 Visit(BCO->getCond());
3701 HandleValue(BCO->getFalseExpr(), AddressOf);
3702 return;
3703 }
3704
3705 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
3706 HandleValue(OVE->getSourceExpr(), AddressOf);
3707 return;
3708 }
3709
3710 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
3711 switch (BO->getOpcode()) {
3712 default:
3713 break;
3714 case(BO_PtrMemD):
3715 case(BO_PtrMemI):
3716 HandleValue(BO->getLHS(), AddressOf);
3717 Visit(BO->getRHS());
3718 return;
3719 case(BO_Comma):
3720 Visit(BO->getLHS());
3721 HandleValue(BO->getRHS(), AddressOf);
3722 return;
3723 }
3724 }
3725
3726 Visit(E);
3727 }
3728
3729 void CheckInitListExpr(InitListExpr *ILE) {
3730 InitFieldIndex.push_back(0);
3731 for (auto Child : ILE->children()) {
3732 if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) {
3733 CheckInitListExpr(SubList);
3734 } else {
3735 Visit(Child);
3736 }
3737 ++InitFieldIndex.back();
3738 }
3739 InitFieldIndex.pop_back();
3740 }
3741
3742 void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor,
3743 FieldDecl *Field, const Type *BaseClass) {
3744 // Remove Decls that may have been initialized in the previous
3745 // initializer.
3746 for (ValueDecl* VD : DeclsToRemove)
3747 Decls.erase(VD);
3748 DeclsToRemove.clear();
3749
3750 Constructor = FieldConstructor;
3751 InitListExpr *ILE = dyn_cast<InitListExpr>(E);
3752
3753 if (ILE && Field) {
3754 InitList = true;
3755 InitListFieldDecl = Field;
3756 InitFieldIndex.clear();
3757 CheckInitListExpr(ILE);
3758 } else {
3759 InitList = false;
3760 Visit(E);
3761 }
3762
3763 if (Field)
3764 Decls.erase(Field);
3765 if (BaseClass)
3766 BaseClasses.erase(BaseClass->getCanonicalTypeInternal());
3767 }
3768
3769 void VisitMemberExpr(MemberExpr *ME) {
3770 // All uses of unbounded reference fields will warn.
3771 HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/);
3772 }
3773
3774 void VisitImplicitCastExpr(ImplicitCastExpr *E) {
3775 if (E->getCastKind() == CK_LValueToRValue) {
3776 HandleValue(E->getSubExpr(), false /*AddressOf*/);
3777 return;
3778 }
3779
3780 Inherited::VisitImplicitCastExpr(E);
3781 }
3782
3783 void VisitCXXConstructExpr(CXXConstructExpr *E) {
3784 if (E->getConstructor()->isCopyConstructor()) {
3785 Expr *ArgExpr = E->getArg(0);
3786 if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
3787 if (ILE->getNumInits() == 1)
3788 ArgExpr = ILE->getInit(0);
3789 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
3790 if (ICE->getCastKind() == CK_NoOp)
3791 ArgExpr = ICE->getSubExpr();
3792 HandleValue(ArgExpr, false /*AddressOf*/);
3793 return;
3794 }
3795 Inherited::VisitCXXConstructExpr(E);
3796 }
3797
3798 void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
3799 Expr *Callee = E->getCallee();
3800 if (isa<MemberExpr>(Callee)) {
3801 HandleValue(Callee, false /*AddressOf*/);
3802 for (auto Arg : E->arguments())
3803 Visit(Arg);
3804 return;
3805 }
3806
3807 Inherited::VisitCXXMemberCallExpr(E);
3808 }
3809
3810 void VisitCallExpr(CallExpr *E) {
3811 // Treat std::move as a use.
3812 if (E->isCallToStdMove()) {
3813 HandleValue(E->getArg(0), /*AddressOf=*/false);
3814 return;
3815 }
3816
3817 Inherited::VisitCallExpr(E);
3818 }
3819
3820 void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
3821 Expr *Callee = E->getCallee();
3822
3823 if (isa<UnresolvedLookupExpr>(Callee))
3824 return Inherited::VisitCXXOperatorCallExpr(E);
3825
3826 Visit(Callee);
3827 for (auto Arg : E->arguments())
3828 HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/);
3829 }
3830
3831 void VisitBinaryOperator(BinaryOperator *E) {
3832 // If a field assignment is detected, remove the field from the
3833 // uninitiailized field set.
3834 if (E->getOpcode() == BO_Assign)
3835 if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS()))
3836 if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3837 if (!FD->getType()->isReferenceType())
3838 DeclsToRemove.push_back(FD);
3839
3840 if (E->isCompoundAssignmentOp()) {
3841 HandleValue(E->getLHS(), false /*AddressOf*/);
3842 Visit(E->getRHS());
3843 return;
3844 }
3845
3846 Inherited::VisitBinaryOperator(E);
3847 }
3848
3849 void VisitUnaryOperator(UnaryOperator *E) {
3850 if (E->isIncrementDecrementOp()) {
3851 HandleValue(E->getSubExpr(), false /*AddressOf*/);
3852 return;
3853 }
3854 if (E->getOpcode() == UO_AddrOf) {
3855 if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) {
3856 HandleValue(ME->getBase(), true /*AddressOf*/);
3857 return;
3858 }
3859 }
3860
3861 Inherited::VisitUnaryOperator(E);
3862 }
3863 };
3864
3865 // Diagnose value-uses of fields to initialize themselves, e.g.
3866 // foo(foo)
3867 // where foo is not also a parameter to the constructor.
3868 // Also diagnose across field uninitialized use such as
3869 // x(y), y(x)
3870 // TODO: implement -Wuninitialized and fold this into that framework.
3871 static void DiagnoseUninitializedFields(
3872 Sema &SemaRef, const CXXConstructorDecl *Constructor) {
3873
3874 if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit,
3875 Constructor->getLocation())) {
3876 return;
3877 }
3878
3879 if (Constructor->isInvalidDecl())
3880 return;
3881
3882 const CXXRecordDecl *RD = Constructor->getParent();
3883
3884 if (RD->isDependentContext())
3885 return;
3886
3887 // Holds fields that are uninitialized.
3888 llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;
3889
3890 // At the beginning, all fields are uninitialized.
3891 for (auto *I : RD->decls()) {
3892 if (auto *FD = dyn_cast<FieldDecl>(I)) {
3893 UninitializedFields.insert(FD);
3894 } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) {
3895 UninitializedFields.insert(IFD->getAnonField());
3896 }
3897 }
3898
3899 llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses;
3900 for (auto I : RD->bases())
3901 UninitializedBaseClasses.insert(I.getType().getCanonicalType());
3902
3903 if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3904 return;
3905
3906 UninitializedFieldVisitor UninitializedChecker(SemaRef,
3907 UninitializedFields,
3908 UninitializedBaseClasses);
3909
3910 for (const auto *FieldInit : Constructor->inits()) {
3911 if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3912 break;
3913
3914 Expr *InitExpr = FieldInit->getInit();
3915 if (!InitExpr)
3916 continue;
3917
3918 if (CXXDefaultInitExpr *Default =
3919 dyn_cast<CXXDefaultInitExpr>(InitExpr)) {
3920 InitExpr = Default->getExpr();
3921 if (!InitExpr)
3922 continue;
3923 // In class initializers will point to the constructor.
3924 UninitializedChecker.CheckInitializer(InitExpr, Constructor,
3925 FieldInit->getAnyMember(),
3926 FieldInit->getBaseClass());
3927 } else {
3928 UninitializedChecker.CheckInitializer(InitExpr, nullptr,
3929 FieldInit->getAnyMember(),
3930 FieldInit->getBaseClass());
3931 }
3932 }
3933 }
3934} // namespace
3935
3936/// Enter a new C++ default initializer scope. After calling this, the
3937/// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if
3938/// parsing or instantiating the initializer failed.
3939void Sema::ActOnStartCXXInClassMemberInitializer() {
3940 // Create a synthetic function scope to represent the call to the constructor
3941 // that notionally surrounds a use of this initializer.
3942 PushFunctionScope();
3943}
3944
3945void Sema::ActOnStartTrailingRequiresClause(Scope *S, Declarator &D) {
3946 if (!D.isFunctionDeclarator())
3947 return;
3948 auto &FTI = D.getFunctionTypeInfo();
3949 if (!FTI.Params)
3950 return;
3951 for (auto &Param : ArrayRef<DeclaratorChunk::ParamInfo>(FTI.Params,
3952 FTI.NumParams)) {
3953 auto *ParamDecl = cast<NamedDecl>(Param.Param);
3954 if (ParamDecl->getDeclName())
3955 PushOnScopeChains(ParamDecl, S, /*AddToContext=*/false);
3956 }
3957}
3958
3959ExprResult Sema::ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr) {
3960 return ActOnRequiresClause(ConstraintExpr);
3961}
3962
3963ExprResult Sema::ActOnRequiresClause(ExprResult ConstraintExpr) {
3964 if (ConstraintExpr.isInvalid())
3965 return ExprError();
3966
3967 ConstraintExpr = CorrectDelayedTyposInExpr(ConstraintExpr);
3968 if (ConstraintExpr.isInvalid())
3969 return ExprError();
3970
3971 if (DiagnoseUnexpandedParameterPack(ConstraintExpr.get(),
3972 UPPC_RequiresClause))
3973 return ExprError();
3974
3975 return ConstraintExpr;
3976}
3977
3978/// This is invoked after parsing an in-class initializer for a
3979/// non-static C++ class member, and after instantiating an in-class initializer
3980/// in a class template. Such actions are deferred until the class is complete.
3981void Sema::ActOnFinishCXXInClassMemberInitializer(Decl *D,
3982 SourceLocation InitLoc,
3983 Expr *InitExpr) {
3984 // Pop the notional constructor scope we created earlier.
3985 PopFunctionScopeInfo(nullptr, D);
3986
3987 FieldDecl *FD = dyn_cast<FieldDecl>(D);
1
Assuming 'D' is not a 'FieldDecl'
2
'FD' initialized to a null pointer value
3988 assert((isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) &&((void)0)
3989 "must set init style when field is created")((void)0);
3990
3991 if (!InitExpr) {
3
Assuming 'InitExpr' is non-null
4
Taking false branch
3992 D->setInvalidDecl();
3993 if (FD)
3994 FD->removeInClassInitializer();
3995 return;
3996 }
3997
3998 if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
5
Assuming the condition is false
6
Taking false branch
3999 FD->setInvalidDecl();
4000 FD->removeInClassInitializer();
4001 return;
4002 }
4003
4004 ExprResult Init = InitExpr;
4005 if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
7
Called C++ object pointer is null
4006 InitializedEntity Entity =
4007 InitializedEntity::InitializeMemberFromDefaultMemberInitializer(FD);
4008 InitializationKind Kind =
4009 FD->getInClassInitStyle() == ICIS_ListInit
4010 ? InitializationKind::CreateDirectList(InitExpr->getBeginLoc(),
4011 InitExpr->getBeginLoc(),
4012 InitExpr->getEndLoc())
4013 : InitializationKind::CreateCopy(InitExpr->getBeginLoc(), InitLoc);
4014 InitializationSequence Seq(*this, Entity, Kind, InitExpr);
4015 Init = Seq.Perform(*this, Entity, Kind, InitExpr);
4016 if (Init.isInvalid()) {
4017 FD->setInvalidDecl();
4018 return;
4019 }
4020 }
4021
4022 // C++11 [class.base.init]p7:
4023 // The initialization of each base and member constitutes a
4024 // full-expression.
4025 Init = ActOnFinishFullExpr(Init.get(), InitLoc, /*DiscardedValue*/ false);
4026 if (Init.isInvalid()) {
4027 FD->setInvalidDecl();
4028 return;
4029 }
4030
4031 InitExpr = Init.get();
4032
4033 FD->setInClassInitializer(InitExpr);
4034}
4035
4036/// Find the direct and/or virtual base specifiers that
4037/// correspond to the given base type, for use in base initialization
4038/// within a constructor.
4039static bool FindBaseInitializer(Sema &SemaRef,
4040 CXXRecordDecl *ClassDecl,
4041 QualType BaseType,
4042 const CXXBaseSpecifier *&DirectBaseSpec,
4043 const CXXBaseSpecifier *&VirtualBaseSpec) {
4044 // First, check for a direct base class.
4045 DirectBaseSpec = nullptr;
4046 for (const auto &Base : ClassDecl->bases()) {
4047 if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) {
4048 // We found a direct base of this type. That's what we're
4049 // initializing.
4050 DirectBaseSpec = &Base;
4051 break;
4052 }
4053 }
4054
4055 // Check for a virtual base class.
4056 // FIXME: We might be able to short-circuit this if we know in advance that
4057 // there are no virtual bases.
4058 VirtualBaseSpec = nullptr;
4059 if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
4060 // We haven't found a base yet; search the class hierarchy for a
4061 // virtual base class.
4062 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
4063 /*DetectVirtual=*/false);
4064 if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
4065 SemaRef.Context.getTypeDeclType(ClassDecl),
4066 BaseType, Paths)) {
4067 for (CXXBasePaths::paths_iterator Path = Paths.begin();
4068 Path != Paths.end(); ++Path) {
4069 if (Path->back().Base->isVirtual()) {
4070 VirtualBaseSpec = Path->back().Base;
4071 break;
4072 }
4073 }
4074 }
4075 }
4076
4077 return DirectBaseSpec || VirtualBaseSpec;
4078}
4079
4080/// Handle a C++ member initializer using braced-init-list syntax.
4081MemInitResult
4082Sema::ActOnMemInitializer(Decl *ConstructorD,
4083 Scope *S,
4084 CXXScopeSpec &SS,
4085 IdentifierInfo *MemberOrBase,
4086 ParsedType TemplateTypeTy,
4087 const DeclSpec &DS,
4088 SourceLocation IdLoc,
4089 Expr *InitList,
4090 SourceLocation EllipsisLoc) {
4091 return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
4092 DS, IdLoc, InitList,
4093 EllipsisLoc);
4094}
4095
4096/// Handle a C++ member initializer using parentheses syntax.
4097MemInitResult
4098Sema::ActOnMemInitializer(Decl *ConstructorD,
4099 Scope *S,
4100 CXXScopeSpec &SS,
4101 IdentifierInfo *MemberOrBase,
4102 ParsedType TemplateTypeTy,
4103 const DeclSpec &DS,
4104 SourceLocation IdLoc,
4105 SourceLocation LParenLoc,
4106 ArrayRef<Expr *> Args,
4107 SourceLocation RParenLoc,
4108 SourceLocation EllipsisLoc) {
4109 Expr *List = ParenListExpr::Create(Context, LParenLoc, Args, RParenLoc);
4110 return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
4111 DS, IdLoc, List, EllipsisLoc);
4112}
4113
4114namespace {
4115
4116// Callback to only accept typo corrections that can be a valid C++ member
4117// intializer: either a non-static field member or a base class.
4118class MemInitializerValidatorCCC final : public CorrectionCandidateCallback {
4119public:
4120 explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
4121 : ClassDecl(ClassDecl) {}
4122
4123 bool ValidateCandidate(const TypoCorrection &candidate) override {
4124 if (NamedDecl *ND = candidate.getCorrectionDecl()) {
4125 if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
4126 return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
4127 return isa<TypeDecl>(ND);
4128 }
4129 return false;
4130 }
4131
4132 std::unique_ptr<CorrectionCandidateCallback> clone() override {
4133 return std::make_unique<MemInitializerValidatorCCC>(*this);
4134 }
4135
4136private:
4137 CXXRecordDecl *ClassDecl;
4138};
4139
4140}
4141
4142ValueDecl *Sema::tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl,
4143 CXXScopeSpec &SS,
4144 ParsedType TemplateTypeTy,
4145 IdentifierInfo *MemberOrBase) {
4146 if (SS.getScopeRep() || TemplateTypeTy)
4147 return nullptr;
4148 for (auto *D : ClassDecl->lookup(MemberOrBase))
4149 if (isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D))
4150 return cast<ValueDecl>(D);
4151 return nullptr;
4152}
4153
4154/// Handle a C++ member initializer.
4155MemInitResult
4156Sema::BuildMemInitializer(Decl *ConstructorD,
4157 Scope *S,
4158 CXXScopeSpec &SS,
4159 IdentifierInfo *MemberOrBase,
4160 ParsedType TemplateTypeTy,
4161 const DeclSpec &DS,
4162 SourceLocation IdLoc,
4163 Expr *Init,
4164 SourceLocation EllipsisLoc) {
4165 ExprResult Res = CorrectDelayedTyposInExpr(Init);
4166 if (!Res.isUsable())
4167 return true;
4168 Init = Res.get();
4169
4170 if (!ConstructorD)
4171 return true;
4172
4173 AdjustDeclIfTemplate(ConstructorD);
4174
4175 CXXConstructorDecl *Constructor
4176 = dyn_cast<CXXConstructorDecl>(ConstructorD);
4177 if (!Constructor) {
4178 // The user wrote a constructor initializer on a function that is
4179 // not a C++ constructor. Ignore the error for now, because we may
4180 // have more member initializers coming; we'll diagnose it just
4181 // once in ActOnMemInitializers.
4182 return true;
4183 }
4184
4185 CXXRecordDecl *ClassDecl = Constructor->getParent();
4186
4187 // C++ [class.base.init]p2:
4188 // Names in a mem-initializer-id are looked up in the scope of the
4189 // constructor's class and, if not found in that scope, are looked
4190 // up in the scope containing the constructor's definition.
4191 // [Note: if the constructor's class contains a member with the
4192 // same name as a direct or virtual base class of the class, a
4193 // mem-initializer-id naming the member or base class and composed
4194 // of a single identifier refers to the class member. A
4195 // mem-initializer-id for the hidden base class may be specified
4196 // using a qualified name. ]
4197
4198 // Look for a member, first.
4199 if (ValueDecl *Member = tryLookupCtorInitMemberDecl(
4200 ClassDecl, SS, TemplateTypeTy, MemberOrBase)) {
4201 if (EllipsisLoc.isValid())
4202 Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
4203 << MemberOrBase
4204 << SourceRange(IdLoc, Init->getSourceRange().getEnd());
4205
4206 return BuildMemberInitializer(Member, Init, IdLoc);
4207 }
4208 // It didn't name a member, so see if it names a class.
4209 QualType BaseType;
4210 TypeSourceInfo *TInfo = nullptr;
4211
4212 if (TemplateTypeTy) {
4213 BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
4214 if (BaseType.isNull())
4215 return true;
4216 } else if (DS.getTypeSpecType() == TST_decltype) {
4217 BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
4218 } else if (DS.getTypeSpecType() == TST_decltype_auto) {
4219 Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
4220 return true;
4221 } else {
4222 LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
4223 LookupParsedName(R, S, &SS);
4224
4225 TypeDecl *TyD = R.getAsSingle<TypeDecl>();
4226 if (!TyD) {
4227 if (R.isAmbiguous()) return true;
4228
4229 // We don't want access-control diagnostics here.
4230 R.suppressDiagnostics();
4231
4232 if (SS.isSet() && isDependentScopeSpecifier(SS)) {
4233 bool NotUnknownSpecialization = false;
4234 DeclContext *DC = computeDeclContext(SS, false);
4235 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
4236 NotUnknownSpecialization = !Record->hasAnyDependentBases();
4237
4238 if (!NotUnknownSpecialization) {
4239 // When the scope specifier can refer to a member of an unknown
4240 // specialization, we take it as a type name.
4241 BaseType = CheckTypenameType(ETK_None, SourceLocation(),
4242 SS.getWithLocInContext(Context),
4243 *MemberOrBase, IdLoc);
4244 if (BaseType.isNull())
4245 return true;
4246
4247 TInfo = Context.CreateTypeSourceInfo(BaseType);
4248 DependentNameTypeLoc TL =
4249 TInfo->getTypeLoc().castAs<DependentNameTypeLoc>();
4250 if (!TL.isNull()) {
4251 TL.setNameLoc(IdLoc);
4252 TL.setElaboratedKeywordLoc(SourceLocation());
4253 TL.setQualifierLoc(SS.getWithLocInContext(Context));
4254 }
4255
4256 R.clear();
4257 R.setLookupName(MemberOrBase);
4258 }
4259 }
4260
4261 // If no results were found, try to correct typos.
4262 TypoCorrection Corr;
4263 MemInitializerValidatorCCC CCC(ClassDecl);
4264 if (R.empty() && BaseType.isNull() &&
4265 (Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
4266 CCC, CTK_ErrorRecovery, ClassDecl))) {
4267 if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
4268 // We have found a non-static data member with a similar
4269 // name to what was typed; complain and initialize that
4270 // member.
4271 diagnoseTypo(Corr,
4272 PDiag(diag::err_mem_init_not_member_or_class_suggest)
4273 << MemberOrBase << true);
4274 return BuildMemberInitializer(Member, Init, IdLoc);
4275 } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
4276 const CXXBaseSpecifier *DirectBaseSpec;
4277 const CXXBaseSpecifier *VirtualBaseSpec;
4278 if (FindBaseInitializer(*this, ClassDecl,
4279 Context.getTypeDeclType(Type),
4280 DirectBaseSpec, VirtualBaseSpec)) {
4281 // We have found a direct or virtual base class with a
4282 // similar name to what was typed; complain and initialize
4283 // that base class.
4284 diagnoseTypo(Corr,
4285 PDiag(diag::err_mem_init_not_member_or_class_suggest)
4286 << MemberOrBase << false,
4287 PDiag() /*Suppress note, we provide our own.*/);
4288
4289 const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec
4290 : VirtualBaseSpec;
4291 Diag(BaseSpec->getBeginLoc(), diag::note_base_class_specified_here)
4292 << BaseSpec->getType() << BaseSpec->getSourceRange();
4293
4294 TyD = Type;
4295 }
4296 }
4297 }
4298
4299 if (!TyD && BaseType.isNull()) {
4300 Diag(IdLoc, diag::err_mem_init_not_member_or_class)
4301 << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
4302 return true;
4303 }
4304 }
4305
4306 if (BaseType.isNull()) {
4307 BaseType = Context.getTypeDeclType(TyD);
4308 MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false);
4309 if (SS.isSet()) {
4310 BaseType = Context.getElaboratedType(ETK_None, SS.getScopeRep(),
4311 BaseType);
4312 TInfo = Context.CreateTypeSourceInfo(BaseType);
4313 ElaboratedTypeLoc TL = TInfo->getTypeLoc().castAs<ElaboratedTypeLoc>();
4314 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
4315 TL.setElaboratedKeywordLoc(SourceLocation());
4316 TL.setQualifierLoc(SS.getWithLocInContext(Context));
4317 }
4318 }
4319 }
4320
4321 if (!TInfo)
4322 TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
4323
4324 return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
4325}
4326
4327MemInitResult
4328Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
4329 SourceLocation IdLoc) {
4330 FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
4331 IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
4332 assert((DirectMember || IndirectMember) &&((void)0)
4333 "Member must be a FieldDecl or IndirectFieldDecl")((void)0);
4334
4335 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4336 return true;
4337
4338 if (Member->isInvalidDecl())
4339 return true;
4340
4341 MultiExprArg Args;
4342 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4343 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4344 } else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
4345 Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
4346 } else {
4347 // Template instantiation doesn't reconstruct ParenListExprs for us.
4348 Args = Init;
4349 }
4350
4351 SourceRange InitRange = Init->getSourceRange();
4352
4353 if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
4354 // Can't check initialization for a member of dependent type or when
4355 // any of the arguments are type-dependent expressions.
4356 DiscardCleanupsInEvaluationContext();
4357 } else {
4358 bool InitList = false;
4359 if (isa<InitListExpr>(Init)) {
4360 InitList = true;
4361 Args = Init;
4362 }
4363
4364 // Initialize the member.
4365 InitializedEntity MemberEntity =
4366 DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr)
4367 : InitializedEntity::InitializeMember(IndirectMember,
4368 nullptr);
4369 InitializationKind Kind =
4370 InitList ? InitializationKind::CreateDirectList(
4371 IdLoc, Init->getBeginLoc(), Init->getEndLoc())
4372 : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
4373 InitRange.getEnd());
4374
4375 InitializationSequence InitSeq(*this, MemberEntity, Kind, Args);
4376 ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args,
4377 nullptr);
4378 if (MemberInit.isInvalid())
4379 return true;
4380
4381 // C++11 [class.base.init]p7:
4382 // The initialization of each base and member constitutes a
4383 // full-expression.
4384 MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin(),
4385 /*DiscardedValue*/ false);
4386 if (MemberInit.isInvalid())
4387 return true;
4388
4389 Init = MemberInit.get();
4390 }
4391
4392 if (DirectMember) {
4393 return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
4394 InitRange.getBegin(), Init,
4395 InitRange.getEnd());
4396 } else {
4397 return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
4398 InitRange.getBegin(), Init,
4399 InitRange.getEnd());
4400 }
4401}
4402
4403MemInitResult
4404Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
4405 CXXRecordDecl *ClassDecl) {
4406 SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
4407 if (!LangOpts.CPlusPlus11)
4408 return Diag(NameLoc, diag::err_delegating_ctor)
4409 << TInfo->getTypeLoc().getLocalSourceRange();
4410 Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
4411
4412 bool InitList = true;
4413 MultiExprArg Args = Init;
4414 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4415 InitList = false;
4416 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4417 }
4418
4419 SourceRange InitRange = Init->getSourceRange();
4420 // Initialize the object.
4421 InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
4422 QualType(ClassDecl->getTypeForDecl(), 0));
4423 InitializationKind Kind =
4424 InitList ? InitializationKind::CreateDirectList(
4425 NameLoc, Init->getBeginLoc(), Init->getEndLoc())
4426 : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
4427 InitRange.getEnd());
4428 InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args);
4429 ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
4430 Args, nullptr);
4431 if (DelegationInit.isInvalid())
4432 return true;
4433
4434 assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() &&((void)0)
4435 "Delegating constructor with no target?")((void)0);
4436
4437 // C++11 [class.base.init]p7:
4438 // The initialization of each base and member constitutes a
4439 // full-expression.
4440 DelegationInit = ActOnFinishFullExpr(
4441 DelegationInit.get(), InitRange.getBegin(), /*DiscardedValue*/ false);
4442 if (DelegationInit.isInvalid())
4443 return true;
4444
4445 // If we are in a dependent context, template instantiation will
4446 // perform this type-checking again. Just save the arguments that we
4447 // received in a ParenListExpr.
4448 // FIXME: This isn't quite ideal, since our ASTs don't capture all
4449 // of the information that we have about the base
4450 // initializer. However, deconstructing the ASTs is a dicey process,
4451 // and this approach is far more likely to get the corner cases right.
4452 if (CurContext->isDependentContext())
4453 DelegationInit = Init;
4454
4455 return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
4456 DelegationInit.getAs<Expr>(),
4457 InitRange.getEnd());
4458}
4459
4460MemInitResult
4461Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
4462 Expr *Init, CXXRecordDecl *ClassDecl,
4463 SourceLocation EllipsisLoc) {
4464 SourceLocation BaseLoc
4465 = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();
4466
4467 if (!BaseType->isDependentType() && !BaseType->isRecordType())
4468 return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
4469 << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4470
4471 // C++ [class.base.init]p2:
4472 // [...] Unless the mem-initializer-id names a nonstatic data
4473 // member of the constructor's class or a direct or virtual base
4474 // of that class, the mem-initializer is ill-formed. A
4475 // mem-initializer-list can initialize a base class using any
4476 // name that denotes that base class type.
4477 bool Dependent = BaseType->isDependentType() || Init->isTypeDependent();
4478
4479 SourceRange InitRange = Init->getSourceRange();
4480 if (EllipsisLoc.isValid()) {
4481 // This is a pack expansion.
4482 if (!BaseType->containsUnexpandedParameterPack()) {
4483 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
4484 << SourceRange(BaseLoc, InitRange.getEnd());
4485
4486 EllipsisLoc = SourceLocation();
4487 }
4488 } else {
4489 // Check for any unexpanded parameter packs.
4490 if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
4491 return true;
4492
4493 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4494 return true;
4495 }
4496
4497 // Check for direct and virtual base classes.
4498 const CXXBaseSpecifier *DirectBaseSpec = nullptr;
4499 const CXXBaseSpecifier *VirtualBaseSpec = nullptr;
4500 if (!Dependent) {
4501 if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
4502 BaseType))
4503 return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
4504
4505 FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
4506 VirtualBaseSpec);
4507
4508 // C++ [base.class.init]p2:
4509 // Unless the mem-initializer-id names a nonstatic data member of the
4510 // constructor's class or a direct or virtual base of that class, the
4511 // mem-initializer is ill-formed.
4512 if (!DirectBaseSpec && !VirtualBaseSpec) {
4513 // If the class has any dependent bases, then it's possible that
4514 // one of those types will resolve to the same type as
4515 // BaseType. Therefore, just treat this as a dependent base
4516 // class initialization. FIXME: Should we try to check the
4517 // initialization anyway? It seems odd.
4518 if (ClassDecl->hasAnyDependentBases())
4519 Dependent = true;
4520 else
4521 return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
4522 << BaseType << Context.getTypeDeclType(ClassDecl)
4523 << BaseTInfo->getTypeLoc().getLocalSourceRange();
4524 }
4525 }
4526
4527 if (Dependent) {
4528 DiscardCleanupsInEvaluationContext();
4529
4530 return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4531 /*IsVirtual=*/false,
4532 InitRange.getBegin(), Init,
4533 InitRange.getEnd(), EllipsisLoc);
4534 }
4535
4536 // C++ [base.class.init]p2:
4537 // If a mem-initializer-id is ambiguous because it designates both
4538 // a direct non-virtual base class and an inherited virtual base
4539 // class, the mem-initializer is ill-formed.
4540 if (DirectBaseSpec && VirtualBaseSpec)
4541 return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
4542 << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4543
4544 const CXXBaseSpecifier *BaseSpec = DirectBaseSpec;
4545 if (!BaseSpec)
4546 BaseSpec = VirtualBaseSpec;
4547
4548 // Initialize the base.
4549 bool InitList = true;
4550 MultiExprArg Args = Init;
4551 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4552 InitList = false;
4553 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4554 }
4555
4556 InitializedEntity BaseEntity =
4557 InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
4558 InitializationKind Kind =
4559 InitList ? InitializationKind::CreateDirectList(BaseLoc)
4560 : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
4561 InitRange.getEnd());
4562 InitializationSequence InitSeq(*this, BaseEntity, Kind, Args);
4563 ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr);
4564 if (BaseInit.isInvalid())
4565 return true;
4566
4567 // C++11 [class.base.init]p7:
4568 // The initialization of each base and member constitutes a
4569 // full-expression.
4570 BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin(),
4571 /*DiscardedValue*/ false);
4572 if (BaseInit.isInvalid())
4573 return true;
4574
4575 // If we are in a dependent context, template instantiation will
4576 // perform this type-checking again. Just save the arguments that we
4577 // received in a ParenListExpr.
4578 // FIXME: This isn't quite ideal, since our ASTs don't capture all
4579 // of the information that we have about the base
4580 // initializer. However, deconstructing the ASTs is a dicey process,
4581 // and this approach is far more likely to get the corner cases right.
4582 if (CurContext->isDependentContext())
4583 BaseInit = Init;
4584
4585 return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4586 BaseSpec->isVirtual(),
4587 InitRange.getBegin(),
4588 BaseInit.getAs<Expr>(),
4589 InitRange.getEnd(), EllipsisLoc);
4590}
4591
4592// Create a static_cast\<T&&>(expr).
4593static Expr *CastForMoving(Sema &SemaRef, Expr *E, QualType T = QualType()) {
4594 if (T.isNull()) T = E->getType();
4595 QualType TargetType = SemaRef.BuildReferenceType(
4596 T, /*SpelledAsLValue*/false, SourceLocation(), DeclarationName());
4597 SourceLocation ExprLoc = E->getBeginLoc();
4598 TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
4599 TargetType, ExprLoc);
4600
4601 return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
4602 SourceRange(ExprLoc, ExprLoc),
4603 E->getSourceRange()).get();
4604}
4605
4606/// ImplicitInitializerKind - How an implicit base or member initializer should
4607/// initialize its base or member.
4608enum ImplicitInitializerKind {
4609 IIK_Default,
4610 IIK_Copy,
4611 IIK_Move,
4612 IIK_Inherit
4613};
4614
4615static bool
4616BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
4617 ImplicitInitializerKind ImplicitInitKind,
4618 CXXBaseSpecifier *BaseSpec,
4619 bool IsInheritedVirtualBase,
4620 CXXCtorInitializer *&CXXBaseInit) {
4621 InitializedEntity InitEntity
4622 = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
4623 IsInheritedVirtualBase);
4624
4625 ExprResult BaseInit;
4626
4627 switch (ImplicitInitKind) {
4628 case IIK_Inherit:
4629 case IIK_Default: {
4630 InitializationKind InitKind
4631 = InitializationKind::CreateDefault(Constructor->getLocation());
4632 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4633 BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4634 break;
4635 }
4636
4637 case IIK_Move:
4638 case IIK_Copy: {
4639 bool Moving = ImplicitInitKind == IIK_Move;
4640 ParmVarDecl *Param = Constructor->getParamDecl(0);
4641 QualType ParamType = Param->getType().getNonReferenceType();
4642
4643 Expr *CopyCtorArg =
4644 DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
4645 SourceLocation(), Param, false,
4646 Constructor->getLocation(), ParamType,
4647 VK_LValue, nullptr);
4648
4649 SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
4650
4651 // Cast to the base class to avoid ambiguities.
4652 QualType ArgTy =
4653 SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
4654 ParamType.getQualifiers());
4655
4656 if (Moving) {
4657 CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
4658 }
4659
4660 CXXCastPath BasePath;
4661 BasePath.push_back(BaseSpec);
4662 CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
4663 CK_UncheckedDerivedToBase,
4664 Moving ? VK_XValue : VK_LValue,
4665 &BasePath).get();
4666
4667 InitializationKind InitKind
4668 = InitializationKind::CreateDirect(Constructor->getLocation(),
4669 SourceLocation(), SourceLocation());
4670 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg);
4671 BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg);
4672 break;
4673 }
4674 }
4675
4676 BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
4677 if (BaseInit.isInvalid())
4678 return true;
4679
4680 CXXBaseInit =
4681 new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4682 SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
4683 SourceLocation()),
4684 BaseSpec->isVirtual(),
4685 SourceLocation(),
4686 BaseInit.getAs<Expr>(),
4687 SourceLocation(),
4688 SourceLocation());
4689
4690 return false;
4691}
4692
4693static bool RefersToRValueRef(Expr *MemRef) {
4694 ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
4695 return Referenced->getType()->isRValueReferenceType();
4696}
4697
4698static bool
4699BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
4700 ImplicitInitializerKind ImplicitInitKind,
4701 FieldDecl *Field, IndirectFieldDecl *Indirect,
4702 CXXCtorInitializer *&CXXMemberInit) {
4703 if (Field->isInvalidDecl())
4704 return true;
4705
4706 SourceLocation Loc = Constructor->getLocation();
4707
4708 if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
4709 bool Moving = ImplicitInitKind == IIK_Move;
4710 ParmVarDecl *Param = Constructor->getParamDecl(0);
4711 QualType ParamType = Param->getType().getNonReferenceType();
4712
4713 // Suppress copying zero-width bitfields.
4714 if (Field->isZeroLengthBitField(SemaRef.Context))
4715 return false;
4716
4717 Expr *MemberExprBase =
4718 DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
4719 SourceLocation(), Param, false,
4720 Loc, ParamType, VK_LValue, nullptr);
4721
4722 SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));
4723
4724 if (Moving) {
4725 MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
4726 }
4727
4728 // Build a reference to this field within the parameter.
4729 CXXScopeSpec SS;
4730 LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
4731 Sema::LookupMemberName);
4732 MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
4733 : cast<ValueDecl>(Field), AS_public);
4734 MemberLookup.resolveKind();
4735 ExprResult CtorArg
4736 = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
4737 ParamType, Loc,
4738 /*IsArrow=*/false,
4739 SS,
4740 /*TemplateKWLoc=*/SourceLocation(),
4741 /*FirstQualifierInScope=*/nullptr,
4742 MemberLookup,
4743 /*TemplateArgs=*/nullptr,
4744 /*S*/nullptr);
4745 if (CtorArg.isInvalid())
4746 return true;
4747
4748 // C++11 [class.copy]p15:
4749 // - if a member m has rvalue reference type T&&, it is direct-initialized
4750 // with static_cast<T&&>(x.m);
4751 if (RefersToRValueRef(CtorArg.get())) {
4752 CtorArg = CastForMoving(SemaRef, CtorArg.get());
4753 }
4754
4755 InitializedEntity Entity =
4756 Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4757 /*Implicit*/ true)
4758 : InitializedEntity::InitializeMember(Field, nullptr,
4759 /*Implicit*/ true);
4760
4761 // Direct-initialize to use the copy constructor.
4762 InitializationKind InitKind =
4763 InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation());
4764
4765 Expr *CtorArgE = CtorArg.getAs<Expr>();
4766 InitializationSequence InitSeq(SemaRef, Entity, InitKind, CtorArgE);
4767 ExprResult MemberInit =
4768 InitSeq.Perform(SemaRef, Entity, InitKind, MultiExprArg(&CtorArgE, 1));
4769 MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4770 if (MemberInit.isInvalid())
4771 return true;
4772
4773 if (Indirect)
4774 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4775 SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4776 else
4777 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4778 SemaRef.Context, Field, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4779 return false;
4780 }
4781
4782 assert((ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) &&((void)0)
4783 "Unhandled implicit init kind!")((void)0);
4784
4785 QualType FieldBaseElementType =
4786 SemaRef.Context.getBaseElementType(Field->getType());
4787
4788 if (FieldBaseElementType->isRecordType()) {
4789 InitializedEntity InitEntity =
4790 Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4791 /*Implicit*/ true)
4792 : InitializedEntity::InitializeMember(Field, nullptr,
4793 /*Implicit*/ true);
4794 InitializationKind InitKind =
4795 InitializationKind::CreateDefault(Loc);
4796
4797 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4798 ExprResult MemberInit =
4799 InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4800
4801 MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4802 if (MemberInit.isInvalid())
4803 return true;
4804
4805 if (Indirect)
4806 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4807 Indirect, Loc,
4808 Loc,
4809 MemberInit.get(),
4810 Loc);
4811 else
4812 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4813 Field, Loc, Loc,
4814 MemberInit.get(),
4815 Loc);
4816 return false;
4817 }
4818
4819 if (!Field->getParent()->isUnion()) {
4820 if (FieldBaseElementType->isReferenceType()) {
4821 SemaRef.Diag(Constructor->getLocation(),
4822 diag::err_uninitialized_member_in_ctor)
4823 << (int)Constructor->isImplicit()
4824 << SemaRef.Context.getTagDeclType(Constructor->getParent())
4825 << 0 << Field->getDeclName();
4826 SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4827 return true;
4828 }
4829
4830 if (FieldBaseElementType.isConstQualified()) {
4831 SemaRef.Diag(Constructor->getLocation(),
4832 diag::err_uninitialized_member_in_ctor)
4833 << (int)Constructor->isImplicit()
4834 << SemaRef.Context.getTagDeclType(Constructor->getParent())
4835 << 1 << Field->getDeclName();
4836 SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4837 return true;
4838 }
4839 }
4840
4841 if (FieldBaseElementType.hasNonTrivialObjCLifetime()) {
4842 // ARC and Weak:
4843 // Default-initialize Objective-C pointers to NULL.
4844 CXXMemberInit
4845 = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
4846 Loc, Loc,
4847 new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
4848 Loc);
4849 return false;
4850 }
4851
4852 // Nothing to initialize.
4853 CXXMemberInit = nullptr;
4854 return false;
4855}
4856
4857namespace {
4858struct BaseAndFieldInfo {
4859 Sema &S;
4860 CXXConstructorDecl *Ctor;
4861 bool AnyErrorsInInits;
4862 ImplicitInitializerKind IIK;
4863 llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
4864 SmallVector<CXXCtorInitializer*, 8> AllToInit;
4865 llvm::DenseMap<TagDecl*, FieldDecl*> ActiveUnionMember;
4866
4867 BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
4868 : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
4869 bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
4870 if (Ctor->getInheritedConstructor())
4871 IIK = IIK_Inherit;
4872 else if (Generated && Ctor->isCopyConstructor())
4873 IIK = IIK_Copy;
4874 else if (Generated && Ctor->isMoveConstructor())
4875 IIK = IIK_Move;
4876 else
4877 IIK = IIK_Default;
4878 }
4879
4880 bool isImplicitCopyOrMove() const {
4881 switch (IIK) {
4882 case IIK_Copy:
4883 case IIK_Move:
4884 return true;
4885
4886 case IIK_Default:
4887 case IIK_Inherit:
4888 return false;
4889 }
4890
4891 llvm_unreachable("Invalid ImplicitInitializerKind!")__builtin_unreachable();
4892 }
4893
4894 bool addFieldInitializer(CXXCtorInitializer *Init) {
4895 AllToInit.push_back(Init);
4896
4897 // Check whether this initializer makes the field "used".
4898 if (Init->getInit()->HasSideEffects(S.Context))
4899 S.UnusedPrivateFields.remove(Init->getAnyMember());
4900
4901 return false;
4902 }
4903
4904 bool isInactiveUnionMember(FieldDecl *Field) {
4905 RecordDecl *Record = Field->getParent();
4906 if (!Record->isUnion())
4907 return false;
4908
4909 if (FieldDecl *Active =
4910 ActiveUnionMember.lookup(Record->getCanonicalDecl()))
4911 return Active != Field->getCanonicalDecl();
4912
4913 // In an implicit copy or move constructor, ignore any in-class initializer.
4914 if (isImplicitCopyOrMove())
4915 return true;
4916
4917 // If there's no explicit initialization, the field is active only if it
4918 // has an in-class initializer...
4919 if (Field->hasInClassInitializer())
4920 return false;
4921 // ... or it's an anonymous struct or union whose class has an in-class
4922 // initializer.
4923 if (!Field->isAnonymousStructOrUnion())
4924 return true;
4925 CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl();
4926 return !FieldRD->hasInClassInitializer();
4927 }
4928
4929 /// Determine whether the given field is, or is within, a union member
4930 /// that is inactive (because there was an initializer given for a different
4931 /// member of the union, or because the union was not initialized at all).
4932 bool isWithinInactiveUnionMember(FieldDecl *Field,
4933 IndirectFieldDecl *Indirect) {
4934 if (!Indirect)
4935 return isInactiveUnionMember(Field);
4936
4937 for (auto *C : Indirect->chain()) {
4938 FieldDecl *Field = dyn_cast<FieldDecl>(C);
4939 if (Field && isInactiveUnionMember(Field))
4940 return true;
4941 }
4942 return false;
4943 }
4944};
4945}
4946
4947/// Determine whether the given type is an incomplete or zero-lenfgth
4948/// array type.
4949static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) {
4950 if (T->isIncompleteArrayType())
4951 return true;
4952
4953 while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
4954 if (!ArrayT->getSize())
4955 return true;
4956
4957 T = ArrayT->getElementType();
4958 }
4959
4960 return false;
4961}
4962
4963static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
4964 FieldDecl *Field,
4965 IndirectFieldDecl *Indirect = nullptr) {
4966 if (Field->isInvalidDecl())
4967 return false;
4968
4969 // Overwhelmingly common case: we have a direct initializer for this field.
4970 if (CXXCtorInitializer *Init =
4971 Info.AllBaseFields.lookup(Field->getCanonicalDecl()))
4972 return Info.addFieldInitializer(Init);
4973
4974 // C++11 [class.base.init]p8:
4975 // if the entity is a non-static data member that has a
4976 // brace-or-equal-initializer and either
4977 // -- the constructor's class is a union and no other variant member of that
4978 // union is designated by a mem-initializer-id or
4979 // -- the constructor's class is not a union, and, if the entity is a member
4980 // of an anonymous union, no other member of that union is designated by
4981 // a mem-initializer-id,
4982 // the entity is initialized as specified in [dcl.init].
4983 //
4984 // We also apply the same rules to handle anonymous structs within anonymous
4985 // unions.
4986 if (Info.isWithinInactiveUnionMember(Field, Indirect))
4987 return false;
4988
4989 if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
4990 ExprResult DIE =
4991 SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field);
4992 if (DIE.isInvalid())
4993 return true;
4994
4995 auto Entity = InitializedEntity::InitializeMember(Field, nullptr, true);
4996 SemaRef.checkInitializerLifetime(Entity, DIE.get());
4997
4998 CXXCtorInitializer *Init;
4999 if (Indirect)
5000 Init = new (SemaRef.Context)
5001 CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(),
5002 SourceLocation(), DIE.get(), SourceLocation());
5003 else
5004 Init = new (SemaRef.Context)
5005 CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(),
5006 SourceLocation(), DIE.get(), SourceLocation());
5007 return Info.addFieldInitializer(Init);
5008 }
5009
5010 // Don't initialize incomplete or zero-length arrays.
5011 if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
5012 return false;
5013
5014 // Don't try to build an implicit initializer if there were semantic
5015 // errors in any of the initializers (and therefore we might be
5016 // missing some that the user actually wrote).
5017 if (Info.AnyErrorsInInits)
5018 return false;
5019
5020 CXXCtorInitializer *Init = nullptr;
5021 if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
5022 Indirect, Init))
5023 return true;
5024
5025 if (!Init)
5026 return false;
5027
5028 return Info.addFieldInitializer(Init);
5029}
5030
5031bool
5032Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor,
5033 CXXCtorInitializer *Initializer) {
5034 assert(Initializer->isDelegatingInitializer())((void)0);
5035 Constructor->setNumCtorInitializers(1);
5036 CXXCtorInitializer **initializer =
5037 new (Context) CXXCtorInitializer*[1];
5038 memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
5039 Constructor->setCtorInitializers(initializer);
5040
5041 if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
5042 MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
5043 DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
5044 }
5045
5046 DelegatingCtorDecls.push_back(Constructor);
5047
5048 DiagnoseUninitializedFields(*this, Constructor);
5049
5050 return false;
5051}
5052
5053bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
5054 ArrayRef<CXXCtorInitializer *> Initializers) {
5055 if (Constructor->isDependentContext()) {
5056 // Just store the initializers as written, they will be checked during
5057 // instantiation.
5058 if (!Initializers.empty()) {
5059 Constructor->setNumCtorInitializers(Initializers.size());
5060 CXXCtorInitializer **baseOrMemberInitializers =
5061 new (Context) CXXCtorInitializer*[Initializers.size()];
5062 memcpy(baseOrMemberInitializers, Initializers.data(),
5063 Initializers.size() * sizeof(CXXCtorInitializer*));
5064 Constructor->setCtorInitializers(baseOrMemberInitializers);
5065 }
5066
5067 // Let template instantiation know whether we had errors.
5068 if (AnyErrors)
5069 Constructor->setInvalidDecl();
5070
5071 return false;
5072 }
5073
5074 BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
5075
5076 // We need to build the initializer AST according to order of construction
5077 // and not what user specified in the Initializers list.
5078 CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
5079 if (!ClassDecl)
5080 return true;
5081
5082 bool HadError = false;
5083
5084 for (unsigned i = 0; i < Initializers.size(); i++) {
5085 CXXCtorInitializer *Member = Initializers[i];
5086
5087 if (Member->isBaseInitializer())
5088 Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
5089 else {
5090 Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member;
5091
5092 if (IndirectFieldDecl *F = Member->getIndirectMember()) {
5093 for (auto *C : F->chain()) {
5094 FieldDecl *FD = dyn_cast<FieldDecl>(C);
5095 if (FD && FD->getParent()->isUnion())
5096 Info.ActiveUnionMember.insert(std::make_pair(
5097 FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
5098 }
5099 } else if (FieldDecl *FD = Member->getMember()) {
5100 if (FD->getParent()->isUnion())
5101 Info.ActiveUnionMember.insert(std::make_pair(
5102 FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
5103 }
5104 }
5105 }
5106
5107 // Keep track of the direct virtual bases.
5108 llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
5109 for (auto &I : ClassDecl->bases()) {
5110 if (I.isVirtual())
5111 DirectVBases.insert(&I);
5112 }
5113
5114 // Push virtual bases before others.
5115 for (auto &VBase : ClassDecl->vbases()) {
5116 if (CXXCtorInitializer *Value
5117 = Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) {
5118 // [class.base.init]p7, per DR257:
5119 // A mem-initializer where the mem-initializer-id names a virtual base
5120 // class is ignored during execution of a constructor of any class that
5121 // is not the most derived class.
5122 if (ClassDecl->isAbstract()) {
5123 // FIXME: Provide a fixit to remove the base specifier. This requires
5124 // tracking the location of the associated comma for a base specifier.
5125 Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored)
5126 << VBase.getType() << ClassDecl;
5127 DiagnoseAbstractType(ClassDecl);
5128 }
5129
5130 Info.AllToInit.push_back(Value);
5131 } else if (!AnyErrors && !ClassDecl->isAbstract()) {
5132 // [class.base.init]p8, per DR257:
5133 // If a given [...] base class is not named by a mem-initializer-id
5134 // [...] and the entity is not a virtual base class of an abstract
5135 // class, then [...] the entity is default-initialized.
5136 bool IsInheritedVirtualBase = !DirectVBases.count(&VBase);
5137 CXXCtorInitializer *CXXBaseInit;
5138 if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
5139 &VBase, IsInheritedVirtualBase,
5140 CXXBaseInit)) {
5141 HadError = true;
5142 continue;
5143 }
5144
5145 Info.AllToInit.push_back(CXXBaseInit);
5146 }
5147 }
5148
5149 // Non-virtual bases.
5150 for (auto &Base : ClassDecl->bases()) {
5151 // Virtuals are in the virtual base list and already constructed.
5152 if (Base.isVirtual())
5153 continue;
5154
5155 if (CXXCtorInitializer *Value
5156 = Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) {
5157 Info.AllToInit.push_back(Value);
5158 } else if (!AnyErrors) {
5159 CXXCtorInitializer *CXXBaseInit;
5160 if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
5161 &Base, /*IsInheritedVirtualBase=*/false,
5162 CXXBaseInit)) {
5163 HadError = true;
5164 continue;
5165 }
5166
5167 Info.AllToInit.push_back(CXXBaseInit);
5168 }
5169 }
5170
5171 // Fields.
5172 for (auto *Mem : ClassDecl->decls()) {
5173 if (auto *F = dyn_cast<FieldDecl>(Mem)) {
5174 // C++ [class.bit]p2:
5175 // A declaration for a bit-field that omits the identifier declares an
5176 // unnamed bit-field. Unnamed bit-fields are not members and cannot be
5177 // initialized.
5178 if (F->isUnnamedBitfield())
5179 continue;
5180
5181 // If we're not generating the implicit copy/move constructor, then we'll
5182 // handle anonymous struct/union fields based on their individual
5183 // indirect fields.
5184 if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove())
5185 continue;
5186
5187 if (CollectFieldInitializer(*this, Info, F))
5188 HadError = true;
5189 continue;
5190 }
5191
5192 // Beyond this point, we only consider default initialization.
5193 if (Info.isImplicitCopyOrMove())
5194 continue;
5195
5196 if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) {
5197 if (F->getType()->isIncompleteArrayType()) {
5198 assert(ClassDecl->hasFlexibleArrayMember() &&((void)0)
5199 "Incomplete array type is not valid")((void)0);
5200 continue;
5201 }
5202
5203 // Initialize each field of an anonymous struct individually.
5204 if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
5205 HadError = true;
5206
5207 continue;
5208 }
5209 }
5210
5211 unsigned NumInitializers = Info.AllToInit.size();
5212 if (NumInitializers > 0) {
5213 Constructor->setNumCtorInitializers(NumInitializers);
5214 CXXCtorInitializer **baseOrMemberInitializers =
5215 new (Context) CXXCtorInitializer*[NumInitializers];
5216 memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
5217 NumInitializers * sizeof(CXXCtorInitializer*));
5218 Constructor->setCtorInitializers(baseOrMemberInitializers);
5219
5220 // Constructors implicitly reference the base and member
5221 // destructors.
5222 MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
5223 Constructor->getParent());
5224 }
5225
5226 return HadError;
5227}
5228
5229static void PopulateKeysForFields(FieldDecl *Field, SmallVectorImpl<const void*> &IdealInits) {
5230 if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
5231 const RecordDecl *RD = RT->getDecl();
5232 if (RD->isAnonymousStructOrUnion()) {
5233 for (auto *Field : RD->fields())
5234 PopulateKeysForFields(Field, IdealInits);
5235 return;
5236 }
5237 }
5238 IdealInits.push_back(Field->getCanonicalDecl());
5239}
5240
5241static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
5242 return Context.getCanonicalType(BaseType).getTypePtr();
5243}
5244
5245static const void *GetKeyForMember(ASTContext &Context,
5246 CXXCtorInitializer *Member) {
5247 if (!Member->isAnyMemberInitializer())
5248 return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
5249
5250 return Member->getAnyMember()->getCanonicalDecl();
5251}
5252
5253static void AddInitializerToDiag(const Sema::SemaDiagnosticBuilder &Diag,
5254 const CXXCtorInitializer *Previous,
5255 const CXXCtorInitializer *Current) {
5256 if (Previous->isAnyMemberInitializer())
5257 Diag << 0 << Previous->getAnyMember();
5258 else
5259 Diag << 1 << Previous->getTypeSourceInfo()->getType();
5260
5261 if (Current->isAnyMemberInitializer())
5262 Diag << 0 << Current->getAnyMember();
5263 else
5264 Diag << 1 << Current->getTypeSourceInfo()->getType();
5265}
5266
5267static void DiagnoseBaseOrMemInitializerOrder(
5268 Sema &SemaRef, const CXXConstructorDecl *Constructor,
5269 ArrayRef<CXXCtorInitializer *> Inits) {
5270 if (Constructor->getDeclContext()->isDependentContext())
5271 return;
5272
5273 // Don't check initializers order unless the warning is enabled at the
5274 // location of at least one initializer.
5275 bool ShouldCheckOrder = false;
5276 for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
5277 CXXCtorInitializer *Init = Inits[InitIndex];
5278 if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order,
5279 Init->getSourceLocation())) {
5280 ShouldCheckOrder = true;
5281 break;
5282 }
5283 }
5284 if (!ShouldCheckOrder)
5285 return;
5286
5287 // Build the list of bases and members in the order that they'll
5288 // actually be initialized. The explicit initializers should be in
5289 // this same order but may be missing things.
5290 SmallVector<const void*, 32> IdealInitKeys;
5291
5292 const CXXRecordDecl *ClassDecl = Constructor->getParent();
5293
5294 // 1. Virtual bases.
5295 for (const auto &VBase : ClassDecl->vbases())
5296 IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType()));
5297
5298 // 2. Non-virtual bases.
5299 for (const auto &Base : ClassDecl->bases()) {
5300 if (Base.isVirtual())
5301 continue;
5302 IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType()));
5303 }
5304
5305 // 3. Direct fields.
5306 for (auto *Field : ClassDecl->fields()) {
5307 if (Field->isUnnamedBitfield())
5308 continue;
5309
5310 PopulateKeysForFields(Field, IdealInitKeys);
5311 }
5312
5313 unsigned NumIdealInits = IdealInitKeys.size();
5314 unsigned IdealIndex = 0;
5315
5316 // Track initializers that are in an incorrect order for either a warning or
5317 // note if multiple ones occur.
5318 SmallVector<unsigned> WarnIndexes;
5319 // Correlates the index of an initializer in the init-list to the index of
5320 // the field/base in the class.
5321 SmallVector<std::pair<unsigned, unsigned>, 32> CorrelatedInitOrder;
5322
5323 for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
5324 const void *InitKey = GetKeyForMember(SemaRef.Context, Inits[InitIndex]);
5325
5326 // Scan forward to try to find this initializer in the idealized
5327 // initializers list.
5328 for (; IdealIndex != NumIdealInits; ++IdealIndex)
5329 if (InitKey == IdealInitKeys[IdealIndex])
5330 break;
5331
5332 // If we didn't find this initializer, it must be because we
5333 // scanned past it on a previous iteration. That can only
5334 // happen if we're out of order; emit a warning.
5335 if (IdealIndex == NumIdealInits && InitIndex) {
5336 WarnIndexes.push_back(InitIndex);
5337
5338 // Move back to the initializer's location in the ideal list.
5339 for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
5340 if (InitKey == IdealInitKeys[IdealIndex])
5341 break;
5342
5343 assert(IdealIndex < NumIdealInits &&((void)0)
5344 "initializer not found in initializer list")((void)0);
5345 }
5346 CorrelatedInitOrder.emplace_back(IdealIndex, InitIndex);
5347 }
5348
5349 if (WarnIndexes.empty())
5350 return;
5351
5352 // Sort based on the ideal order, first in the pair.
5353 llvm::sort(CorrelatedInitOrder,
5354 [](auto &LHS, auto &RHS) { return LHS.first < RHS.first; });
5355
5356 // Introduce a new scope as SemaDiagnosticBuilder needs to be destroyed to
5357 // emit the diagnostic before we can try adding notes.
5358 {
5359 Sema::SemaDiagnosticBuilder D = SemaRef.Diag(
5360 Inits[WarnIndexes.front() - 1]->getSourceLocation(),
5361 WarnIndexes.size() == 1 ? diag::warn_initializer_out_of_order
5362 : diag::warn_some_initializers_out_of_order);
5363
5364 for (unsigned I = 0; I < CorrelatedInitOrder.size(); ++I) {
5365 if (CorrelatedInitOrder[I].second == I)
5366 continue;
5367 // Ideally we would be using InsertFromRange here, but clang doesn't
5368 // appear to handle InsertFromRange correctly when the source range is
5369 // modified by another fix-it.
5370 D << FixItHint::CreateReplacement(
5371 Inits[I]->getSourceRange(),
5372 Lexer::getSourceText(
5373 CharSourceRange::getTokenRange(
5374 Inits[CorrelatedInitOrder[I].second]->getSourceRange()),
5375 SemaRef.getSourceManager(), SemaRef.getLangOpts()));
5376 }
5377
5378 // If there is only 1 item out of order, the warning expects the name and
5379 // type of each being added to it.
5380 if (WarnIndexes.size() == 1) {
5381 AddInitializerToDiag(D, Inits[WarnIndexes.front() - 1],
5382 Inits[WarnIndexes.front()]);
5383 return;
5384 }
5385 }
5386 // More than 1 item to warn, create notes letting the user know which ones
5387 // are bad.
5388 for (unsigned WarnIndex : WarnIndexes) {
5389 const clang::CXXCtorInitializer *PrevInit = Inits[WarnIndex - 1];
5390 auto D = SemaRef.Diag(PrevInit->getSourceLocation(),
5391 diag::note_initializer_out_of_order);
5392 AddInitializerToDiag(D, PrevInit, Inits[WarnIndex]);
5393 D << PrevInit->getSourceRange();
5394 }
5395}
5396
5397namespace {
5398bool CheckRedundantInit(Sema &S,
5399 CXXCtorInitializer *Init,
5400 CXXCtorInitializer *&PrevInit) {
5401 if (!PrevInit) {
5402 PrevInit = Init;
5403 return false;
5404 }
5405
5406 if (FieldDecl *Field = Init->getAnyMember())
5407 S.Diag(Init->getSourceLocation(),
5408 diag::err_multiple_mem_initialization)
5409 << Field->getDeclName()
5410 << Init->getSourceRange();
5411 else {
5412 const Type *BaseClass = Init->getBaseClass();
5413 assert(BaseClass && "neither field nor base")((void)0);
5414 S.Diag(Init->getSourceLocation(),
5415 diag::err_multiple_base_initialization)
5416 << QualType(BaseClass, 0)
5417 << Init->getSourceRange();
5418 }
5419 S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
5420 << 0 << PrevInit->getSourceRange();
5421
5422 return true;
5423}
5424
5425typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
5426typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
5427
5428bool CheckRedundantUnionInit(Sema &S,
5429 CXXCtorInitializer *Init,
5430 RedundantUnionMap &Unions) {
5431 FieldDecl *Field = Init->getAnyMember();
5432 RecordDecl *Parent = Field->getParent();
5433 NamedDecl *Child = Field;
5434
5435 while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
5436 if (Parent->isUnion()) {
5437 UnionEntry &En = Unions[Parent];
5438 if (En.first && En.first != Child) {
5439 S.Diag(Init->getSourceLocation(),
5440 diag::err_multiple_mem_union_initialization)
5441 << Field->getDeclName()
5442 << Init->getSourceRange();
5443 S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
5444 << 0 << En.second->getSourceRange();
5445 return true;
5446 }
5447 if (!En.first) {
5448 En.first = Child;
5449 En.second = Init;
5450 }
5451 if (!Parent->isAnonymousStructOrUnion())
5452 return false;
5453 }
5454
5455 Child = Parent;
5456 Parent = cast<RecordDecl>(Parent->getDeclContext());
5457 }
5458
5459 return false;
5460}
5461} // namespace
5462
5463/// ActOnMemInitializers - Handle the member initializers for a constructor.
5464void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
5465 SourceLocation ColonLoc,
5466 ArrayRef<CXXCtorInitializer*> MemInits,
5467 bool AnyErrors) {
5468 if (!ConstructorDecl)
5469 return;
5470
5471 AdjustDeclIfTemplate(ConstructorDecl);
5472
5473 CXXConstructorDecl *Constructor
5474 = dyn_cast<CXXConstructorDecl>(ConstructorDecl);
5475
5476 if (!Constructor) {
5477 Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
5478 return;
5479 }
5480
5481 // Mapping for the duplicate initializers check.
5482 // For member initializers, this is keyed with a FieldDecl*.
5483 // For base initializers, this is keyed with a Type*.
5484 llvm::DenseMap<const void *, CXXCtorInitializer *> Members;
5485
5486 // Mapping for the inconsistent anonymous-union initializers check.
5487 RedundantUnionMap MemberUnions;
5488
5489 bool HadError = false;
5490 for (unsigned i = 0; i < MemInits.size(); i++) {
5491 CXXCtorInitializer *Init = MemInits[i];
5492
5493 // Set the source order index.
5494 Init->setSourceOrder(i);
5495
5496 if (Init->isAnyMemberInitializer()) {
5497 const void *Key = GetKeyForMember(Context, Init);
5498 if (CheckRedundantInit(*this, Init, Members[Key]) ||
5499 CheckRedundantUnionInit(*this, Init, MemberUnions))
5500 HadError = true;
5501 } else if (Init->isBaseInitializer()) {
5502 const void *Key = GetKeyForMember(Context, Init);
5503 if (CheckRedundantInit(*this, Init, Members[Key]))
5504 HadError = true;
5505 } else {
5506 assert(Init->isDelegatingInitializer())((void)0);
5507 // This must be the only initializer
5508 if (MemInits.size() != 1) {
5509 Diag(Init->getSourceLocation(),
5510 diag::err_delegating_initializer_alone)
5511 << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange();
5512 // We will treat this as being the only initializer.
5513 }
5514 SetDelegatingInitializer(Constructor, MemInits[i]);
5515 // Return immediately as the initializer is set.
5516 return;
5517 }
5518 }
5519
5520 if (HadError)
5521 return;
5522
5523 DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits);
5524
5525 SetCtorInitializers(Constructor, AnyErrors, MemInits);
5526
5527 DiagnoseUninitializedFields(*this, Constructor);
5528}
5529
5530void
5531Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,
5532 CXXRecordDecl *ClassDecl) {
5533 // Ignore dependent contexts. Also ignore unions, since their members never
5534 // have destructors implicitly called.
5535 if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
5536 return;
5537
5538 // FIXME: all the access-control diagnostics are positioned on the
5539 // field/base declaration. That's probably good; that said, the
5540 // user might reasonably want to know why the destructor is being
5541 // emitted, and we currently don't say.
5542
5543 // Non-static data members.
5544 for (auto *Field : ClassDecl->fields()) {
5545 if (Field->isInvalidDecl())
5546 continue;
5547
5548 // Don't destroy incomplete or zero-length arrays.
5549 if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
5550 continue;
5551
5552 QualType FieldType = Context.getBaseElementType(Field->getType());
5553
5554 const RecordType* RT = FieldType->getAs<RecordType>();
5555 if (!RT)
5556 continue;
5557
5558 CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5559 if (FieldClassDecl->isInvalidDecl())
5560 continue;
5561 if (FieldClassDecl->hasIrrelevantDestructor())
5562 continue;
5563 // The destructor for an implicit anonymous union member is never invoked.
5564 if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
5565 continue;
5566
5567 CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
5568 assert(Dtor && "No dtor found for FieldClassDecl!")((void)0);
5569 CheckDestructorAccess(Field->getLocation(), Dtor,
5570 PDiag(diag::err_access_dtor_field)
5571 << Field->getDeclName()
5572 << FieldType);
5573
5574 MarkFunctionReferenced(Location, Dtor);
5575 DiagnoseUseOfDecl(Dtor, Location);
5576 }
5577
5578 // We only potentially invoke the destructors of potentially constructed
5579 // subobjects.
5580 bool VisitVirtualBases = !ClassDecl->isAbstract();
5581
5582 // If the destructor exists and has already been marked used in the MS ABI,
5583 // then virtual base destructors have already been checked and marked used.
5584 // Skip checking them again to avoid duplicate diagnostics.
5585 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
5586 CXXDestructorDecl *Dtor = ClassDecl->getDestructor();
5587 if (Dtor && Dtor->isUsed())
5588 VisitVirtualBases = false;
5589 }
5590
5591 llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
5592
5593 // Bases.
5594 for (const auto &Base : ClassDecl->bases()) {
5595 const RecordType *RT = Base.getType()->getAs<RecordType>();
5596 if (!RT)
5597 continue;
5598
5599 // Remember direct virtual bases.
5600 if (Base.isVirtual()) {
5601 if (!VisitVirtualBases)
5602 continue;
5603 DirectVirtualBases.insert(RT);
5604 }
5605
5606 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5607 // If our base class is invalid, we probably can't get its dtor anyway.
5608 if (BaseClassDecl->isInvalidDecl())
5609 continue;
5610 if (BaseClassDecl->hasIrrelevantDestructor())
5611 continue;
5612
5613 CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5614 assert(Dtor && "No dtor found for BaseClassDecl!")((void)0);
5615
5616 // FIXME: caret should be on the start of the class name
5617 CheckDestructorAccess(Base.getBeginLoc(), Dtor,
5618 PDiag(diag::err_access_dtor_base)
5619 << Base.getType() << Base.getSourceRange(),
5620 Context.getTypeDeclType(ClassDecl));
5621
5622 MarkFunctionReferenced(Location, Dtor);
5623 DiagnoseUseOfDecl(Dtor, Location);
5624 }
5625
5626 if (VisitVirtualBases)
5627 MarkVirtualBaseDestructorsReferenced(Location, ClassDecl,
5628 &DirectVirtualBases);
5629}
5630
5631void Sema::MarkVirtualBaseDestructorsReferenced(
5632 SourceLocation Location, CXXRecordDecl *ClassDecl,
5633 llvm::SmallPtrSetImpl<const RecordType *> *DirectVirtualBases) {
5634 // Virtual bases.
5635 for (const auto &VBase : ClassDecl->vbases()) {
5636 // Bases are always records in a well-formed non-dependent class.
5637 const RecordType *RT = VBase.getType()->castAs<RecordType>();
5638
5639 // Ignore already visited direct virtual bases.
5640 if (DirectVirtualBases && DirectVirtualBases->count(RT))
5641 continue;
5642
5643 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5644 // If our base class is invalid, we probably can't get its dtor anyway.
5645 if (BaseClassDecl->isInvalidDecl())
5646 continue;
5647 if (BaseClassDecl->hasIrrelevantDestructor())
5648 continue;
5649
5650 CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5651 assert(Dtor && "No dtor found for BaseClassDecl!")((void)0);
5652 if (CheckDestructorAccess(
5653 ClassDecl->getLocation(), Dtor,
5654 PDiag(diag::err_access_dtor_vbase)
5655 << Context.getTypeDeclType(ClassDecl) << VBase.getType(),
5656 Context.getTypeDeclType(ClassDecl)) ==
5657 AR_accessible) {
5658 CheckDerivedToBaseConversion(
5659 Context.getTypeDeclType(ClassDecl), VBase.getType(),
5660 diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(),
5661 SourceRange(), DeclarationName(), nullptr);
5662 }
5663
5664 MarkFunctionReferenced(Location, Dtor);
5665 DiagnoseUseOfDecl(Dtor, Location);
5666 }
5667}
5668
5669void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
5670 if (!CDtorDecl)
5671 return;
5672
5673 if (CXXConstructorDecl *Constructor
5674 = dyn_cast<CXXConstructorDecl>(CDtorDecl)) {
5675 SetCtorInitializers(Constructor, /*AnyErrors=*/false);
5676 DiagnoseUninitializedFields(*this, Constructor);
5677 }
5678}
5679
5680bool Sema::isAbstractType(SourceLocation Loc, QualType T) {
5681 if (!getLangOpts().CPlusPlus)
5682 return false;
5683
5684 const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl();
5685 if (!RD)
5686 return false;
5687
5688 // FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a
5689 // class template specialization here, but doing so breaks a lot of code.
5690
5691 // We can't answer whether something is abstract until it has a
5692 // definition. If it's currently being defined, we'll walk back
5693 // over all the declarations when we have a full definition.
5694 const CXXRecordDecl *Def = RD->getDefinition();
5695 if (!Def || Def->isBeingDefined())
5696 return false;
5697
5698 return RD->isAbstract();
5699}
5700
5701bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
5702 TypeDiagnoser &Diagnoser) {
5703 if (!isAbstractType(Loc, T))
5704 return false;
5705
5706 T = Context.getBaseElementType(T);
5707 Diagnoser.diagnose(*this, Loc, T);
5708 DiagnoseAbstractType(T->getAsCXXRecordDecl());
5709 return true;
5710}
5711
5712void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) {
5713 // Check if we've already emitted the list of pure virtual functions
5714 // for this class.
5715 if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
5716 return;
5717
5718 // If the diagnostic is suppressed, don't emit the notes. We're only
5719 // going to emit them once, so try to attach them to a diagnostic we're
5720 // actually going to show.
5721 if (Diags.isLastDiagnosticIgnored())
5722 return;
5723
5724 CXXFinalOverriderMap FinalOverriders;
5725 RD->getFinalOverriders(FinalOverriders);
5726
5727 // Keep a set of seen pure methods so we won't diagnose the same method
5728 // more than once.
5729 llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
5730
5731 for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
5732 MEnd = FinalOverriders.end();
5733 M != MEnd;
5734 ++M) {
5735 for (OverridingMethods::iterator SO = M->second.begin(),
5736 SOEnd = M->second.end();
5737 SO != SOEnd; ++SO) {
5738 // C++ [class.abstract]p4:
5739 // A class is abstract if it contains or inherits at least one
5740 // pure virtual function for which the final overrider is pure
5741 // virtual.
5742
5743 //
5744 if (SO->second.size() != 1)
5745 continue;
5746
5747 if (!SO->second.front().Method->isPure())
5748 continue;
5749
5750 if (!SeenPureMethods.insert(SO->second.front().Method).second)
5751 continue;
5752
5753 Diag(SO->second.front().Method->getLocation(),
5754 diag::note_pure_virtual_function)
5755 << SO->second.front().Method->getDeclName() << RD->getDeclName();
5756 }
5757 }
5758
5759 if (!PureVirtualClassDiagSet)
5760 PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
5761 PureVirtualClassDiagSet->insert(RD);
5762}
5763
5764namespace {
5765struct AbstractUsageInfo {
5766 Sema &S;
5767 CXXRecordDecl *Record;
5768 CanQualType AbstractType;
5769 bool Invalid;
5770
5771 AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
5772 : S(S), Record(Record),
5773 AbstractType(S.Context.getCanonicalType(
5774 S.Context.getTypeDeclType(Record))),
5775 Invalid(false) {}
5776
5777 void DiagnoseAbstractType() {
5778 if (Invalid) return;
5779 S.DiagnoseAbstractType(Record);
5780 Invalid = true;
5781 }
5782
5783 void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
5784};
5785
5786struct CheckAbstractUsage {
5787 AbstractUsageInfo &Info;
5788 const NamedDecl *Ctx;
5789
5790 CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
5791 : Info(Info), Ctx(Ctx) {}
5792
5793 void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5794 switch (TL.getTypeLocClass()) {
5795#define ABSTRACT_TYPELOC(CLASS, PARENT)
5796#define TYPELOC(CLASS, PARENT) \
5797 case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break;
5798#include "clang/AST/TypeLocNodes.def"
5799 }
5800 }
5801
5802 void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5803 Visit(TL.getReturnLoc(), Sema::AbstractReturnType);
5804 for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) {
5805 if (!TL.getParam(I))
5806 continue;
5807
5808 TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo();
5809 if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
5810 }
5811 }
5812
5813 void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5814 Visit(TL.getElementLoc(), Sema::AbstractArrayType);
5815 }
5816
5817 void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5818 // Visit the type parameters from a permissive context.
5819 for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
5820 TemplateArgumentLoc TAL = TL.getArgLoc(I);
5821 if (TAL.getArgument().getKind() == TemplateArgument::Type)
5822 if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
5823 Visit(TSI->getTypeLoc(), Sema::AbstractNone);
5824 // TODO: other template argument types?
5825 }
5826 }
5827
5828 // Visit pointee types from a permissive context.
5829#define CheckPolymorphic(Type)void Check(Type TL, Sema::AbstractDiagSelID Sel) { Visit(TL.getNextTypeLoc
(), Sema::AbstractNone); }
\
5830 void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
5831 Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
5832 }
5833 CheckPolymorphic(PointerTypeLoc)void Check(PointerTypeLoc TL, Sema::AbstractDiagSelID Sel) { Visit
(TL.getNextTypeLoc(), Sema::AbstractNone); }
5834 CheckPolymorphic(ReferenceTypeLoc)void Check(ReferenceTypeLoc TL, Sema::AbstractDiagSelID Sel) {
Visit(TL.getNextTypeLoc(), Sema::AbstractNone); }
5835 CheckPolymorphic(MemberPointerTypeLoc)void Check(MemberPointerTypeLoc TL, Sema::AbstractDiagSelID Sel
) { Visit(TL.getNextTypeLoc(), Sema::AbstractNone); }
5836 CheckPolymorphic(BlockPointerTypeLoc)void Check(BlockPointerTypeLoc TL, Sema::AbstractDiagSelID Sel
) { Visit(TL.getNextTypeLoc(), Sema::AbstractNone); }
5837 CheckPolymorphic(AtomicTypeLoc)void Check(AtomicTypeLoc TL, Sema::AbstractDiagSelID Sel) { Visit
(TL.getNextTypeLoc(), Sema::AbstractNone); }
5838
5839 /// Handle all the types we haven't given a more specific
5840 /// implementation for above.
5841 void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5842 // Every other kind of type that we haven't called out already
5843 // that has an inner type is either (1) sugar or (2) contains that
5844 // inner type in some way as a subobject.
5845 if (TypeLoc Next = TL.getNextTypeLoc())
5846 return Visit(Next, Sel);
5847
5848 // If there's no inner type and we're in a permissive context,
5849 // don't diagnose.
5850 if (Sel == Sema::AbstractNone) return;
5851
5852 // Check whether the type matches the abstract type.
5853 QualType T = TL.getType();
5854 if (T->isArrayType()) {
5855 Sel = Sema::AbstractArrayType;
5856 T = Info.S.Context.getBaseElementType(T);
5857 }
5858 CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType();
5859 if (CT != Info.AbstractType) return;
5860
5861 // It matched; do some magic.
5862 if (Sel == Sema::AbstractArrayType) {
5863 Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
5864 << T << TL.getSourceRange();
5865 } else {
5866 Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
5867 << Sel << T << TL.getSourceRange();
5868 }
5869 Info.DiagnoseAbstractType();
5870 }
5871};
5872
5873void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
5874 Sema::AbstractDiagSelID Sel) {
5875 CheckAbstractUsage(*this, D).Visit(TL, Sel);
5876}
5877
5878}
5879
5880/// Check for invalid uses of an abstract type in a method declaration.
5881static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5882 CXXMethodDecl *MD) {
5883 // No need to do the check on definitions, which require that
5884 // the return/param types be complete.
5885 if (MD->doesThisDeclarationHaveABody())
5886 return;
5887
5888 // For safety's sake, just ignore it if we don't have type source
5889 // information. This should never happen for non-implicit methods,
5890 // but...
5891 if (TypeSourceInfo *TSI = MD->getTypeSourceInfo())
5892 Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone);
5893}
5894
5895/// Check for invalid uses of an abstract type within a class definition.
5896static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5897 CXXRecordDecl *RD) {
5898 for (auto *D : RD->decls()) {
5899 if (D->isImplicit()) continue;
5900
5901 // Methods and method templates.
5902 if (isa<CXXMethodDecl>(D)) {
5903 CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D));
5904 } else if (isa<FunctionTemplateDecl>(D)) {
5905 FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl();
5906 CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD));
5907
5908 // Fields and static variables.
5909 } else if (isa<FieldDecl>(D)) {
5910 FieldDecl *FD = cast<FieldDecl>(D);
5911 if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
5912 Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
5913 } else if (isa<VarDecl>(D)) {
5914 VarDecl *VD = cast<VarDecl>(D);
5915 if (TypeSourceInfo *TSI = VD->getTypeSourceInfo())
5916 Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType);
5917
5918 // Nested classes and class templates.
5919 } else if (isa<CXXRecordDecl>(D)) {
5920 CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D));
5921 } else if (isa<ClassTemplateDecl>(D)) {
5922 CheckAbstractClassUsage(Info,
5923 cast<ClassTemplateDecl>(D)->getTemplatedDecl());
5924 }
5925 }
5926}
5927
5928static void ReferenceDllExportedMembers(Sema &S, CXXRecordDecl *Class) {
5929 Attr *ClassAttr = getDLLAttr(Class);
5930 if (!ClassAttr)
5931 return;
5932
5933 assert(ClassAttr->getKind() == attr::DLLExport)((void)0);
5934
5935 TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();
5936
5937 if (TSK == TSK_ExplicitInstantiationDeclaration)
5938 // Don't go any further if this is just an explicit instantiation
5939 // declaration.
5940 return;
5941
5942 // Add a context note to explain how we got to any diagnostics produced below.
5943 struct MarkingClassDllexported {
5944 Sema &S;
5945 MarkingClassDllexported(Sema &S, CXXRecordDecl *Class,
5946 SourceLocation AttrLoc)
5947 : S(S) {
5948 Sema::CodeSynthesisContext Ctx;
5949 Ctx.Kind = Sema::CodeSynthesisContext::MarkingClassDllexported;
5950 Ctx.PointOfInstantiation = AttrLoc;
5951 Ctx.Entity = Class;
5952 S.pushCodeSynthesisContext(Ctx);
5953 }
5954 ~MarkingClassDllexported() {
5955 S.popCodeSynthesisContext();
5956 }
5957 } MarkingDllexportedContext(S, Class, ClassAttr->getLocation());
5958
5959 if (S.Context.getTargetInfo().getTriple().isWindowsGNUEnvironment())
5960 S.MarkVTableUsed(Class->getLocation(), Class, true);
5961
5962 for (Decl *Member : Class->decls()) {
5963 // Defined static variables that are members of an exported base
5964 // class must be marked export too.
5965 auto *VD = dyn_cast<VarDecl>(Member);
5966 if (VD && Member->getAttr<DLLExportAttr>() &&
5967 VD->getStorageClass() == SC_Static &&
5968 TSK == TSK_ImplicitInstantiation)
5969 S.MarkVariableReferenced(VD->getLocation(), VD);
5970
5971 auto *MD = dyn_cast<CXXMethodDecl>(Member);
5972 if (!MD)
5973 continue;
5974
5975 if (Member->getAttr<DLLExportAttr>()) {
5976 if (MD->isUserProvided()) {
5977 // Instantiate non-default class member functions ...
5978
5979 // .. except for certain kinds of template specializations.
5980 if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited())
5981 continue;
5982
5983 S.MarkFunctionReferenced(Class->getLocation(), MD);
5984
5985 // The function will be passed to the consumer when its definition is
5986 // encountered.
5987 } else if (MD->isExplicitlyDefaulted()) {
5988 // Synthesize and instantiate explicitly defaulted methods.
5989 S.MarkFunctionReferenced(Class->getLocation(), MD);
5990
5991 if (TSK != TSK_ExplicitInstantiationDefinition) {
5992 // Except for explicit instantiation defs, we will not see the
5993 // definition again later, so pass it to the consumer now.
5994 S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD));
5995 }
5996 } else if (!MD->isTrivial() ||
5997 MD->isCopyAssignmentOperator() ||
5998 MD->isMoveAssignmentOperator()) {
5999 // Synthesize and instantiate non-trivial implicit methods, and the copy
6000 // and move assignment operators. The latter are exported even if they
6001 // are trivial, because the address of an operator can be taken and
6002 // should compare equal across libraries.
6003 S.MarkFunctionReferenced(Class->getLocation(), MD);
6004
6005 // There is no later point when we will see the definition of this
6006 // function, so pass it to the consumer now.
6007 S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD));
6008 }
6009 }
6010 }
6011}
6012
6013static void checkForMultipleExportedDefaultConstructors(Sema &S,
6014 CXXRecordDecl *Class) {
6015 // Only the MS ABI has default constructor closures, so we don't need to do
6016 // this semantic checking anywhere else.
6017 if (!S.Context.getTargetInfo().getCXXABI().isMicrosoft())
6018 return;
6019
6020 CXXConstructorDecl *LastExportedDefaultCtor = nullptr;
6021 for (Decl *Member : Class->decls()) {
6022 // Look for exported default constructors.
6023 auto *CD = dyn_cast<CXXConstructorDecl>(Member);
6024 if (!CD || !CD->isDefaultConstructor())
6025 continue;
6026 auto *Attr = CD->getAttr<DLLExportAttr>();
6027 if (!Attr)
6028 continue;
6029
6030 // If the class is non-dependent, mark the default arguments as ODR-used so
6031 // that we can properly codegen the constructor closure.
6032 if (!Class->isDependentContext()) {
6033 for (ParmVarDecl *PD : CD->parameters()) {
6034 (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), CD, PD);
6035 S.DiscardCleanupsInEvaluationContext();
6036 }
6037 }
6038
6039 if (LastExportedDefaultCtor) {
6040 S.Diag(LastExportedDefaultCtor->getLocation(),
6041 diag::err_attribute_dll_ambiguous_default_ctor)
6042 << Class;
6043 S.Diag(CD->getLocation(), diag::note_entity_declared_at)
6044 << CD->getDeclName();
6045 return;
6046 }
6047 LastExportedDefaultCtor = CD;
6048 }
6049}
6050
6051static void checkCUDADeviceBuiltinSurfaceClassTemplate(Sema &S,
6052 CXXRecordDecl *Class) {
6053 bool ErrorReported = false;
6054 auto reportIllegalClassTemplate = [&ErrorReported](Sema &S,
6055 ClassTemplateDecl *TD) {
6056 if (ErrorReported)
6057 return;
6058 S.Diag(TD->getLocation(),
6059 diag::err_cuda_device_builtin_surftex_cls_template)
6060 << /*surface*/ 0 << TD;
6061 ErrorReported = true;
6062 };
6063
6064 ClassTemplateDecl *TD = Class->getDescribedClassTemplate();
6065 if (!TD) {
6066 auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(Class);
6067 if (!SD) {
6068 S.Diag(Class->getLocation(),
6069 diag::err_cuda_device_builtin_surftex_ref_decl)
6070 << /*surface*/ 0 << Class;
6071 S.Diag(Class->getLocation(),
6072 diag::note_cuda_device_builtin_surftex_should_be_template_class)
6073 << Class;
6074 return;
6075 }
6076 TD = SD->getSpecializedTemplate();
6077 }
6078
6079 TemplateParameterList *Params = TD->getTemplateParameters();
6080 unsigned N = Params->size();
6081
6082 if (N != 2) {
6083 reportIllegalClassTemplate(S, TD);
6084 S.Diag(TD->getLocation(),
6085 diag::note_cuda_device_builtin_surftex_cls_should_have_n_args)
6086 << TD << 2;
6087 }
6088 if (N > 0 && !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
6089 reportIllegalClassTemplate(S, TD);
6090 S.Diag(TD->getLocation(),
6091 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
6092 << TD << /*1st*/ 0 << /*type*/ 0;
6093 }
6094 if (N > 1) {
6095 auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(1));
6096 if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) {
6097 reportIllegalClassTemplate(S, TD);
6098 S.Diag(TD->getLocation(),
6099 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
6100 << TD << /*2nd*/ 1 << /*integer*/ 1;
6101 }
6102 }
6103}
6104
6105static void checkCUDADeviceBuiltinTextureClassTemplate(Sema &S,
6106 CXXRecordDecl *Class) {
6107 bool ErrorReported = false;
6108 auto reportIllegalClassTemplate = [&ErrorReported](Sema &S,
6109 ClassTemplateDecl *TD) {
6110 if (ErrorReported)
6111 return;
6112 S.Diag(TD->getLocation(),
6113 diag::err_cuda_device_builtin_surftex_cls_template)
6114 << /*texture*/ 1 << TD;
6115 ErrorReported = true;
6116 };
6117
6118 ClassTemplateDecl *TD = Class->getDescribedClassTemplate();
6119 if (!TD) {
6120 auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(Class);
6121 if (!SD) {
6122 S.Diag(Class->getLocation(),
6123 diag::err_cuda_device_builtin_surftex_ref_decl)
6124 << /*texture*/ 1 << Class;
6125 S.Diag(Class->getLocation(),
6126 diag::note_cuda_device_builtin_surftex_should_be_template_class)
6127 << Class;
6128 return;
6129 }
6130 TD = SD->getSpecializedTemplate();
6131 }
6132
6133 TemplateParameterList *Params = TD->getTemplateParameters();
6134 unsigned N = Params->size();
6135
6136 if (N != 3) {
6137 reportIllegalClassTemplate(S, TD);
6138 S.Diag(TD->getLocation(),
6139 diag::note_cuda_device_builtin_surftex_cls_should_have_n_args)
6140 << TD << 3;
6141 }
6142 if (N > 0 && !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
6143 reportIllegalClassTemplate(S, TD);
6144 S.Diag(TD->getLocation(),
6145 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
6146 << TD << /*1st*/ 0 << /*type*/ 0;
6147 }
6148 if (N > 1) {
6149 auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(1));
6150 if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) {
6151 reportIllegalClassTemplate(S, TD);
6152 S.Diag(TD->getLocation(),
6153 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
6154 << TD << /*2nd*/ 1 << /*integer*/ 1;
6155 }
6156 }
6157 if (N > 2) {
6158 auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(2));
6159 if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) {
6160 reportIllegalClassTemplate(S, TD);
6161 S.Diag(TD->getLocation(),
6162 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg)
6163 << TD << /*3rd*/ 2 << /*integer*/ 1;
6164 }
6165 }
6166}
6167
6168void Sema::checkClassLevelCodeSegAttribute(CXXRecordDecl *Class) {
6169 // Mark any compiler-generated routines with the implicit code_seg attribute.
6170 for (auto *Method : Class->methods()) {
6171 if (Method->isUserProvided())
6172 continue;
6173 if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
6174 Method->addAttr(A);
6175 }
6176}
6177
6178/// Check class-level dllimport/dllexport attribute.
6179void Sema::checkClassLevelDLLAttribute(CXXRecordDecl *Class) {
6180 Attr *ClassAttr = getDLLAttr(Class);
6181
6182 // MSVC inherits DLL attributes to partial class template specializations.
6183 if (Context.getTargetInfo().shouldDLLImportComdatSymbols() && !ClassAttr) {
6184 if (auto *Spec = dyn_cast<ClassTemplatePartialSpecializationDecl>(Class)) {
6185 if (Attr *TemplateAttr =
6186 getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) {
6187 auto *A = cast<InheritableAttr>(TemplateAttr->clone(getASTContext()));
6188 A->setInherited(true);
6189 ClassAttr = A;
6190 }
6191 }
6192 }
6193
6194 if (!ClassAttr)
6195 return;
6196
6197 if (!Class->isExternallyVisible()) {
6198 Diag(Class->getLocation(), diag::err_attribute_dll_not_extern)
6199 << Class << ClassAttr;
6200 return;
6201 }
6202
6203 if (Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
6204 !ClassAttr->isInherited()) {
6205 // Diagnose dll attributes on members of class with dll attribute.
6206 for (Decl *Member : Class->decls()) {
6207 if (!isa<VarDecl>(Member) && !isa<CXXMethodDecl>(Member))
6208 continue;
6209 InheritableAttr *MemberAttr = getDLLAttr(Member);
6210 if (!MemberAttr || MemberAttr->isInherited() || Member->isInvalidDecl())
6211 continue;
6212
6213 Diag(MemberAttr->getLocation(),
6214 diag::err_attribute_dll_member_of_dll_class)
6215 << MemberAttr << ClassAttr;
6216 Diag(ClassAttr->getLocation(), diag::note_previous_attribute);
6217 Member->setInvalidDecl();
6218 }
6219 }
6220
6221 if (Class->getDescribedClassTemplate())
6222 // Don't inherit dll attribute until the template is instantiated.
6223 return;
6224
6225 // The class is either imported or exported.
6226 const bool ClassExported = ClassAttr->getKind() == attr::DLLExport;
6227
6228 // Check if this was a dllimport attribute propagated from a derived class to
6229 // a base class template specialization. We don't apply these attributes to
6230 // static data members.
6231 const bool PropagatedImport =
6232 !ClassExported &&
6233 cast<DLLImportAttr>(ClassAttr)->wasPropagatedToBaseTemplate();
6234
6235 TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();
6236
6237 // Ignore explicit dllexport on explicit class template instantiation
6238 // declarations, except in MinGW mode.
6239 if (ClassExported && !ClassAttr->isInherited() &&
6240 TSK == TSK_ExplicitInstantiationDeclaration &&
6241 !Context.getTargetInfo().getTriple().isWindowsGNUEnvironment()) {
6242 Class->dropAttr<DLLExportAttr>();
6243 return;
6244 }
6245
6246 // Force declaration of implicit members so they can inherit the attribute.
6247 ForceDeclarationOfImplicitMembers(Class);
6248
6249 // FIXME: MSVC's docs say all bases must be exportable, but this doesn't
6250 // seem to be true in practice?
6251
6252 for (Decl *Member : Class->decls()) {
6253 VarDecl *VD = dyn_cast<VarDecl>(Member);
6254 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
6255
6256 // Only methods and static fields inherit the attributes.
6257 if (!VD && !MD)
6258 continue;
6259
6260 if (MD) {
6261 // Don't process deleted methods.
6262 if (MD->isDeleted())
6263 continue;
6264
6265 if (MD->isInlined()) {
6266 // MinGW does not import or export inline methods. But do it for
6267 // template instantiations.
6268 if (!Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
6269 TSK != TSK_ExplicitInstantiationDeclaration &&
6270 TSK != TSK_ExplicitInstantiationDefinition)
6271 continue;
6272
6273 // MSVC versions before 2015 don't export the move assignment operators
6274 // and move constructor, so don't attempt to import/export them if
6275 // we have a definition.
6276 auto *Ctor = dyn_cast<CXXConstructorDecl>(MD);
6277 if ((MD->isMoveAssignmentOperator() ||
6278 (Ctor && Ctor->isMoveConstructor())) &&
6279 !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015))
6280 continue;
6281
6282 // MSVC2015 doesn't export trivial defaulted x-tor but copy assign
6283 // operator is exported anyway.
6284 if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
6285 (Ctor || isa<CXXDestructorDecl>(MD)) && MD->isTrivial())
6286 continue;
6287 }
6288 }
6289
6290 // Don't apply dllimport attributes to static data members of class template
6291 // instantiations when the attribute is propagated from a derived class.
6292 if (VD && PropagatedImport)
6293 continue;
6294
6295 if (!cast<NamedDecl>(Member)->isExternallyVisible())
6296 continue;
6297
6298 if (!getDLLAttr(Member)) {
6299 InheritableAttr *NewAttr = nullptr;
6300
6301 // Do not export/import inline function when -fno-dllexport-inlines is
6302 // passed. But add attribute for later local static var check.
6303 if (!getLangOpts().DllExportInlines && MD && MD->isInlined() &&
6304 TSK != TSK_ExplicitInstantiationDeclaration &&
6305 TSK != TSK_ExplicitInstantiationDefinition) {
6306 if (ClassExported) {
6307 NewAttr = ::new (getASTContext())
6308 DLLExportStaticLocalAttr(getASTContext(), *ClassAttr);
6309 } else {
6310 NewAttr = ::new (getASTContext())
6311 DLLImportStaticLocalAttr(getASTContext(), *ClassAttr);
6312 }
6313 } else {
6314 NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
6315 }
6316
6317 NewAttr->setInherited(true);
6318 Member->addAttr(NewAttr);
6319
6320 if (MD) {
6321 // Propagate DLLAttr to friend re-declarations of MD that have already
6322 // been constructed.
6323 for (FunctionDecl *FD = MD->getMostRecentDecl(); FD;
6324 FD = FD->getPreviousDecl()) {
6325 if (FD->getFriendObjectKind() == Decl::FOK_None)
6326 continue;
6327 assert(!getDLLAttr(FD) &&((void)0)
6328 "friend re-decl should not already have a DLLAttr")((void)0);
6329 NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
6330 NewAttr->setInherited(true);
6331 FD->addAttr(NewAttr);
6332 }
6333 }
6334 }
6335 }
6336
6337 if (ClassExported)
6338 DelayedDllExportClasses.push_back(Class);
6339}
6340
6341/// Perform propagation of DLL attributes from a derived class to a
6342/// templated base class for MS compatibility.
6343void Sema::propagateDLLAttrToBaseClassTemplate(
6344 CXXRecordDecl *Class, Attr *ClassAttr,
6345 ClassTemplateSpecializationDecl *BaseTemplateSpec, SourceLocation BaseLoc) {
6346 if (getDLLAttr(
6347 BaseTemplateSpec->getSpecializedTemplate()->getTemplatedDecl())) {
6348 // If the base class template has a DLL attribute, don't try to change it.
6349 return;
6350 }
6351
6352 auto TSK = BaseTemplateSpec->getSpecializationKind();
6353 if (!getDLLAttr(BaseTemplateSpec) &&
6354 (TSK == TSK_Undeclared || TSK == TSK_ExplicitInstantiationDeclaration ||
6355 TSK == TSK_ImplicitInstantiation)) {
6356 // The template hasn't been instantiated yet (or it has, but only as an
6357 // explicit instantiation declaration or implicit instantiation, which means
6358 // we haven't codegenned any members yet), so propagate the attribute.
6359 auto *NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
6360 NewAttr->setInherited(true);
6361 BaseTemplateSpec->addAttr(NewAttr);
6362
6363 // If this was an import, mark that we propagated it from a derived class to
6364 // a base class template specialization.
6365 if (auto *ImportAttr = dyn_cast<DLLImportAttr>(NewAttr))
6366 ImportAttr->setPropagatedToBaseTemplate();
6367
6368 // If the template is already instantiated, checkDLLAttributeRedeclaration()
6369 // needs to be run again to work see the new attribute. Otherwise this will
6370 // get run whenever the template is instantiated.
6371 if (TSK != TSK_Undeclared)
6372 checkClassLevelDLLAttribute(BaseTemplateSpec);
6373
6374 return;
6375 }
6376
6377 if (getDLLAttr(BaseTemplateSpec)) {
6378 // The template has already been specialized or instantiated with an
6379 // attribute, explicitly or through propagation. We should not try to change
6380 // it.
6381 return;
6382 }
6383
6384 // The template was previously instantiated or explicitly specialized without
6385 // a dll attribute, It's too late for us to add an attribute, so warn that
6386 // this is unsupported.
6387 Diag(BaseLoc, diag::warn_attribute_dll_instantiated_base_class)
6388 << BaseTemplateSpec->isExplicitSpecialization();
6389 Diag(ClassAttr->getLocation(), diag::note_attribute);
6390 if (BaseTemplateSpec->isExplicitSpecialization()) {
6391 Diag(BaseTemplateSpec->getLocation(),
6392 diag::note_template_class_explicit_specialization_was_here)
6393 << BaseTemplateSpec;
6394 } else {
6395 Diag(BaseTemplateSpec->getPointOfInstantiation(),
6396 diag::note_template_class_instantiation_was_here)
6397 << BaseTemplateSpec;
6398 }
6399}
6400
6401/// Determine the kind of defaulting that would be done for a given function.
6402///
6403/// If the function is both a default constructor and a copy / move constructor
6404/// (due to having a default argument for the first parameter), this picks
6405/// CXXDefaultConstructor.
6406///
6407/// FIXME: Check that case is properly handled by all callers.
6408Sema::DefaultedFunctionKind
6409Sema::getDefaultedFunctionKind(const FunctionDecl *FD) {
6410 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
6411 if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(FD)) {
6412 if (Ctor->isDefaultConstructor())
6413 return Sema::CXXDefaultConstructor;
6414
6415 if (Ctor->isCopyConstructor())
6416 return Sema::CXXCopyConstructor;
6417
6418 if (Ctor->isMoveConstructor())
6419 return Sema::CXXMoveConstructor;
6420 }
6421
6422 if (MD->isCopyAssignmentOperator())
6423 return Sema::CXXCopyAssignment;
6424
6425 if (MD->isMoveAssignmentOperator())
6426 return Sema::CXXMoveAssignment;
6427
6428 if (isa<CXXDestructorDecl>(FD))
6429 return Sema::CXXDestructor;
6430 }
6431
6432 switch (FD->getDeclName().getCXXOverloadedOperator()) {
6433 case OO_EqualEqual:
6434 return DefaultedComparisonKind::Equal;
6435
6436 case OO_ExclaimEqual:
6437 return DefaultedComparisonKind::NotEqual;
6438
6439 case OO_Spaceship:
6440 // No point allowing this if <=> doesn't exist in the current language mode.
6441 if (!getLangOpts().CPlusPlus20)
6442 break;
6443 return DefaultedComparisonKind::ThreeWay;
6444
6445 case OO_Less:
6446 case OO_LessEqual:
6447 case OO_Greater:
6448 case OO_GreaterEqual:
6449 // No point allowing this if <=> doesn't exist in the current language mode.
6450 if (!getLangOpts().CPlusPlus20)
6451 break;
6452 return DefaultedComparisonKind::Relational;
6453
6454 default:
6455 break;
6456 }
6457
6458 // Not defaultable.
6459 return DefaultedFunctionKind();
6460}
6461
6462static void DefineDefaultedFunction(Sema &S, FunctionDecl *FD,
6463 SourceLocation DefaultLoc) {
6464 Sema::DefaultedFunctionKind DFK = S.getDefaultedFunctionKind(FD);
6465 if (DFK.isComparison())
6466 return S.DefineDefaultedComparison(DefaultLoc, FD, DFK.asComparison());
6467
6468 switch (DFK.asSpecialMember()) {
6469 case Sema::CXXDefaultConstructor:
6470 S.DefineImplicitDefaultConstructor(DefaultLoc,
6471 cast<CXXConstructorDecl>(FD));
6472 break;
6473 case Sema::CXXCopyConstructor:
6474 S.DefineImplicitCopyConstructor(DefaultLoc, cast<CXXConstructorDecl>(FD));
6475 break;
6476 case Sema::CXXCopyAssignment:
6477 S.DefineImplicitCopyAssignment(DefaultLoc, cast<CXXMethodDecl>(FD));
6478 break;
6479 case Sema::CXXDestructor:
6480 S.DefineImplicitDestructor(DefaultLoc, cast<CXXDestructorDecl>(FD));
6481 break;
6482 case Sema::CXXMoveConstructor:
6483 S.DefineImplicitMoveConstructor(DefaultLoc, cast<CXXConstructorDecl>(FD));
6484 break;
6485 case Sema::CXXMoveAssignment:
6486 S.DefineImplicitMoveAssignment(DefaultLoc, cast<CXXMethodDecl>(FD));
6487 break;
6488 case Sema::CXXInvalid:
6489 llvm_unreachable("Invalid special member.")__builtin_unreachable();
6490 }
6491}
6492
6493/// Determine whether a type is permitted to be passed or returned in
6494/// registers, per C++ [class.temporary]p3.
6495static bool canPassInRegisters(Sema &S, CXXRecordDecl *D,
6496 TargetInfo::CallingConvKind CCK) {
6497 if (D->isDependentType() || D->isInvalidDecl())
6498 return false;
6499
6500 // Clang <= 4 used the pre-C++11 rule, which ignores move operations.
6501 // The PS4 platform ABI follows the behavior of Clang 3.2.
6502 if (CCK == TargetInfo::CCK_ClangABI4OrPS4)
6503 return !D->hasNonTrivialDestructorForCall() &&
6504 !D->hasNonTrivialCopyConstructorForCall();
6505
6506 if (CCK == TargetInfo::CCK_MicrosoftWin64) {
6507 bool CopyCtorIsTrivial = false, CopyCtorIsTrivialForCall = false;
6508 bool DtorIsTrivialForCall = false;
6509
6510 // If a class has at least one non-deleted, trivial copy constructor, it
6511 // is passed according to the C ABI. Otherwise, it is passed indirectly.
6512 //
6513 // Note: This permits classes with non-trivial copy or move ctors to be
6514 // passed in registers, so long as they *also* have a trivial copy ctor,
6515 // which is non-conforming.
6516 if (D->needsImplicitCopyConstructor()) {
6517 if (!D->defaultedCopyConstructorIsDeleted()) {
6518 if (D->hasTrivialCopyConstructor())
6519 CopyCtorIsTrivial = true;
6520 if (D->hasTrivialCopyConstructorForCall())
6521 CopyCtorIsTrivialForCall = true;
6522 }
6523 } else {
6524 for (const CXXConstructorDecl *CD : D->ctors()) {
6525 if (CD->isCopyConstructor() && !CD->isDeleted()) {
6526 if (CD->isTrivial())
6527 CopyCtorIsTrivial = true;
6528 if (CD->isTrivialForCall())
6529 CopyCtorIsTrivialForCall = true;
6530 }
6531 }
6532 }
6533
6534 if (D->needsImplicitDestructor()) {
6535 if (!D->defaultedDestructorIsDeleted() &&
6536 D->hasTrivialDestructorForCall())
6537 DtorIsTrivialForCall = true;
6538 } else if (const auto *DD = D->getDestructor()) {
6539 if (!DD->isDeleted() && DD->isTrivialForCall())
6540 DtorIsTrivialForCall = true;
6541 }
6542
6543 // If the copy ctor and dtor are both trivial-for-calls, pass direct.
6544 if (CopyCtorIsTrivialForCall && DtorIsTrivialForCall)
6545 return true;
6546
6547 // If a class has a destructor, we'd really like to pass it indirectly
6548 // because it allows us to elide copies. Unfortunately, MSVC makes that
6549 // impossible for small types, which it will pass in a single register or
6550 // stack slot. Most objects with dtors are large-ish, so handle that early.
6551 // We can't call out all large objects as being indirect because there are
6552 // multiple x64 calling conventions and the C++ ABI code shouldn't dictate
6553 // how we pass large POD types.
6554
6555 // Note: This permits small classes with nontrivial destructors to be
6556 // passed in registers, which is non-conforming.
6557 bool isAArch64 = S.Context.getTargetInfo().getTriple().isAArch64();
6558 uint64_t TypeSize = isAArch64 ? 128 : 64;
6559
6560 if (CopyCtorIsTrivial &&
6561 S.getASTContext().getTypeSize(D->getTypeForDecl()) <= TypeSize)
6562 return true;
6563 return false;
6564 }
6565
6566 // Per C++ [class.temporary]p3, the relevant condition is:
6567 // each copy constructor, move constructor, and destructor of X is
6568 // either trivial or deleted, and X has at least one non-deleted copy
6569 // or move constructor
6570 bool HasNonDeletedCopyOrMove = false;
6571
6572 if (D->needsImplicitCopyConstructor() &&
6573 !D->defaultedCopyConstructorIsDeleted()) {
6574 if (!D->hasTrivialCopyConstructorForCall())
6575 return false;
6576 HasNonDeletedCopyOrMove = true;
6577 }
6578
6579 if (S.getLangOpts().CPlusPlus11 && D->needsImplicitMoveConstructor() &&
6580 !D->defaultedMoveConstructorIsDeleted()) {
6581 if (!D->hasTrivialMoveConstructorForCall())
6582 return false;
6583 HasNonDeletedCopyOrMove = true;
6584 }
6585
6586 if (D->needsImplicitDestructor() && !D->defaultedDestructorIsDeleted() &&
6587 !D->hasTrivialDestructorForCall())
6588 return false;
6589
6590 for (const CXXMethodDecl *MD : D->methods()) {
6591 if (MD->isDeleted())
6592 continue;
6593
6594 auto *CD = dyn_cast<CXXConstructorDecl>(MD);
6595 if (CD && CD->isCopyOrMoveConstructor())
6596 HasNonDeletedCopyOrMove = true;
6597 else if (!isa<CXXDestructorDecl>(MD))
6598 continue;
6599
6600 if (!MD->isTrivialForCall())
6601 return false;
6602 }
6603
6604 return HasNonDeletedCopyOrMove;
6605}
6606
6607/// Report an error regarding overriding, along with any relevant
6608/// overridden methods.
6609///
6610/// \param DiagID the primary error to report.
6611/// \param MD the overriding method.
6612static bool
6613ReportOverrides(Sema &S, unsigned DiagID, const CXXMethodDecl *MD,
6614 llvm::function_ref<bool(const CXXMethodDecl *)> Report) {
6615 bool IssuedDiagnostic = false;
6616 for (const CXXMethodDecl *O : MD->overridden_methods()) {
6617 if (Report(O)) {
6618 if (!IssuedDiagnostic) {
6619 S.Diag(MD->getLocation(), DiagID) << MD->getDeclName();
6620 IssuedDiagnostic = true;
6621 }
6622 S.Diag(O->getLocation(), diag::note_overridden_virtual_function);
6623 }
6624 }
6625 return IssuedDiagnostic;
6626}
6627
6628/// Perform semantic checks on a class definition that has been
6629/// completing, introducing implicitly-declared members, checking for
6630/// abstract types, etc.
6631///
6632/// \param S The scope in which the class was parsed. Null if we didn't just
6633/// parse a class definition.
6634/// \param Record The completed class.
6635void Sema::CheckCompletedCXXClass(Scope *S, CXXRecordDecl *Record) {
6636 if (!Record)
6637 return;
6638
6639 if (Record->isAbstract() && !Record->isInvalidDecl()) {
6640 AbstractUsageInfo Info(*this, Record);
6641 CheckAbstractClassUsage(Info, Record);
6642 }
6643
6644 // If this is not an aggregate type and has no user-declared constructor,
6645 // complain about any non-static data members of reference or const scalar
6646 // type, since they will never get initializers.
6647 if (!Record->isInvalidDecl() && !Record->isDependentType() &&
6648 !Record->isAggregate() && !Record->hasUserDeclaredConstructor() &&
6649 !Record->isLambda()) {
6650 bool Complained = false;
6651 for (const auto *F : Record->fields()) {
6652 if (F->hasInClassInitializer() || F->isUnnamedBitfield())
6653 continue;
6654
6655 if (F->getType()->isReferenceType() ||
6656 (F->getType().isConstQualified() && F->getType()->isScalarType())) {
6657 if (!Complained) {
6658 Diag(Record->getLocation(), diag::warn_no_constructor_for_refconst)
6659 << Record->getTagKind() << Record;
6660 Complained = true;
6661 }
6662
6663 Diag(F->getLocation(), diag::note_refconst_member_not_initialized)
6664 << F->getType()->isReferenceType()
6665 << F->getDeclName();
6666 }
6667 }
6668 }
6669
6670 if (Record->getIdentifier()) {
6671 // C++ [class.mem]p13:
6672 // If T is the name of a class, then each of the following shall have a
6673 // name different from T:
6674 // - every member of every anonymous union that is a member of class T.
6675 //
6676 // C++ [class.mem]p14:
6677 // In addition, if class T has a user-declared constructor (12.1), every
6678 // non-static data member of class T shall have a name different from T.
6679 DeclContext::lookup_result R = Record->lookup(Record->getDeclName());
6680 for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E;
6681 ++I) {
6682 NamedDecl *D = (*I)->getUnderlyingDecl();
6683 if (((isa<FieldDecl>(D) || isa<UnresolvedUsingValueDecl>(D)) &&
6684 Record->hasUserDeclaredConstructor()) ||
6685 isa<IndirectFieldDecl>(D)) {
6686 Diag((*I)->getLocation(), diag::err_member_name_of_class)
6687 << D->getDeclName();
6688 break;
6689 }
6690 }
6691 }
6692
6693 // Warn if the class has virtual methods but non-virtual public destructor.
6694 if (Record->isPolymorphic() && !Record->isDependentType()) {
6695 CXXDestructorDecl *dtor = Record->getDestructor();
6696 if ((!dtor || (!dtor->isVirtual() && dtor->getAccess() == AS_public)) &&
6697 !Record->hasAttr<FinalAttr>())
6698 Diag(dtor ? dtor->getLocation() : Record->getLocation(),
6699 diag::warn_non_virtual_dtor) << Context.getRecordType(Record);
6700 }
6701
6702 if (Record->isAbstract()) {
6703 if (FinalAttr *FA = Record->getAttr<FinalAttr>()) {
6704 Diag(Record->getLocation(), diag::warn_abstract_final_class)
6705 << FA->isSpelledAsSealed();
6706 DiagnoseAbstractType(Record);
6707 }
6708 }
6709
6710 // Warn if the class has a final destructor but is not itself marked final.
6711 if (!Record->hasAttr<FinalAttr>()) {
6712 if (const CXXDestructorDecl *dtor = Record->getDestructor()) {
6713 if (const FinalAttr *FA = dtor->getAttr<FinalAttr>()) {
6714 Diag(FA->getLocation(), diag::warn_final_dtor_non_final_class)
6715 << FA->isSpelledAsSealed()
6716 << FixItHint::CreateInsertion(
6717 getLocForEndOfToken(Record->getLocation()),
6718 (FA->isSpelledAsSealed() ? " sealed" : " final"));
6719 Diag(Record->getLocation(),
6720 diag::note_final_dtor_non_final_class_silence)
6721 << Context.getRecordType(Record) << FA->isSpelledAsSealed();
6722 }
6723 }
6724 }
6725
6726 // See if trivial_abi has to be dropped.
6727 if (Record->hasAttr<TrivialABIAttr>())
6728 checkIllFormedTrivialABIStruct(*Record);
6729
6730 // Set HasTrivialSpecialMemberForCall if the record has attribute
6731 // "trivial_abi".
6732 bool HasTrivialABI = Record->hasAttr<TrivialABIAttr>();
6733
6734 if (HasTrivialABI)
6735 Record->setHasTrivialSpecialMemberForCall();
6736
6737 // Explicitly-defaulted secondary comparison functions (!=, <, <=, >, >=).
6738 // We check these last because they can depend on the properties of the
6739 // primary comparison functions (==, <=>).
6740 llvm::SmallVector<FunctionDecl*, 5> DefaultedSecondaryComparisons;
6741
6742 // Perform checks that can't be done until we know all the properties of a
6743 // member function (whether it's defaulted, deleted, virtual, overriding,
6744 // ...).
6745 auto CheckCompletedMemberFunction = [&](CXXMethodDecl *MD) {
6746 // A static function cannot override anything.
6747 if (MD->getStorageClass() == SC_Static) {
6748 if (ReportOverrides(*this, diag::err_static_overrides_virtual, MD,
6749 [](const CXXMethodDecl *) { return true; }))
6750 return;
6751 }
6752
6753 // A deleted function cannot override a non-deleted function and vice
6754 // versa.
6755 if (ReportOverrides(*this,
6756 MD->isDeleted() ? diag::err_deleted_override
6757 : diag::err_non_deleted_override,
6758 MD, [&](const CXXMethodDecl *V) {
6759 return MD->isDeleted() != V->isDeleted();
6760 })) {
6761 if (MD->isDefaulted() && MD->isDeleted())
6762 // Explain why this defaulted function was deleted.
6763 DiagnoseDeletedDefaultedFunction(MD);
6764 return;
6765 }
6766
6767 // A consteval function cannot override a non-consteval function and vice
6768 // versa.
6769 if (ReportOverrides(*this,
6770 MD->isConsteval() ? diag::err_consteval_override
6771 : diag::err_non_consteval_override,
6772 MD, [&](const CXXMethodDecl *V) {
6773 return MD->isConsteval() != V->isConsteval();
6774 })) {
6775 if (MD->isDefaulted() && MD->isDeleted())
6776 // Explain why this defaulted function was deleted.
6777 DiagnoseDeletedDefaultedFunction(MD);
6778 return;
6779 }
6780 };
6781
6782 auto CheckForDefaultedFunction = [&](FunctionDecl *FD) -> bool {
6783 if (!FD || FD->isInvalidDecl() || !FD->isExplicitlyDefaulted())
6784 return false;
6785
6786 DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD);
6787 if (DFK.asComparison() == DefaultedComparisonKind::NotEqual ||
6788 DFK.asComparison() == DefaultedComparisonKind::Relational) {
6789 DefaultedSecondaryComparisons.push_back(FD);
6790 return true;
6791 }
6792
6793 CheckExplicitlyDefaultedFunction(S, FD);
6794 return false;
6795 };
6796
6797 auto CompleteMemberFunction = [&](CXXMethodDecl *M) {
6798 // Check whether the explicitly-defaulted members are valid.
6799 bool Incomplete = CheckForDefaultedFunction(M);
6800
6801 // Skip the rest of the checks for a member of a dependent class.
6802 if (Record->isDependentType())
6803 return;
6804
6805 // For an explicitly defaulted or deleted special member, we defer
6806 // determining triviality until the class is complete. That time is now!
6807 CXXSpecialMember CSM = getSpecialMember(M);
6808 if (!M->isImplicit() && !M->isUserProvided()) {
6809 if (CSM != CXXInvalid) {
6810 M->setTrivial(SpecialMemberIsTrivial(M, CSM));
6811 // Inform the class that we've finished declaring this member.
6812 Record->finishedDefaultedOrDeletedMember(M);
6813 M->setTrivialForCall(
6814 HasTrivialABI ||
6815 SpecialMemberIsTrivial(M, CSM, TAH_ConsiderTrivialABI));
6816 Record->setTrivialForCallFlags(M);
6817 }
6818 }
6819
6820 // Set triviality for the purpose of calls if this is a user-provided
6821 // copy/move constructor or destructor.
6822 if ((CSM == CXXCopyConstructor || CSM == CXXMoveConstructor ||
6823 CSM == CXXDestructor) && M->isUserProvided()) {
6824 M->setTrivialForCall(HasTrivialABI);
6825 Record->setTrivialForCallFlags(M);
6826 }
6827
6828 if (!M->isInvalidDecl() && M->isExplicitlyDefaulted() &&
6829 M->hasAttr<DLLExportAttr>()) {
6830 if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
6831 M->isTrivial() &&
6832 (CSM == CXXDefaultConstructor || CSM == CXXCopyConstructor ||
6833 CSM == CXXDestructor))
6834 M->dropAttr<DLLExportAttr>();
6835
6836 if (M->hasAttr<DLLExportAttr>()) {
6837 // Define after any fields with in-class initializers have been parsed.
6838 DelayedDllExportMemberFunctions.push_back(M);
6839 }
6840 }
6841
6842 // Define defaulted constexpr virtual functions that override a base class
6843 // function right away.
6844 // FIXME: We can defer doing this until the vtable is marked as used.
6845 if (M->isDefaulted() && M->isConstexpr() && M->size_overridden_methods())
6846 DefineDefaultedFunction(*this, M, M->getLocation());
6847
6848 if (!Incomplete)
6849 CheckCompletedMemberFunction(M);
6850 };
6851
6852 // Check the destructor before any other member function. We need to
6853 // determine whether it's trivial in order to determine whether the claas
6854 // type is a literal type, which is a prerequisite for determining whether
6855 // other special member functions are valid and whether they're implicitly
6856 // 'constexpr'.
6857 if (CXXDestructorDecl *Dtor = Record->getDestructor())
6858 CompleteMemberFunction(Dtor);
6859
6860 bool HasMethodWithOverrideControl = false,
6861 HasOverridingMethodWithoutOverrideControl = false;
6862 for (auto *D : Record->decls()) {
6863 if (auto *M = dyn_cast<CXXMethodDecl>(D)) {
6864 // FIXME: We could do this check for dependent types with non-dependent
6865 // bases.
6866 if (!Record->isDependentType()) {
6867 // See if a method overloads virtual methods in a base
6868 // class without overriding any.
6869 if (!M->isStatic())
6870 DiagnoseHiddenVirtualMethods(M);
6871 if (M->hasAttr<OverrideAttr>())
6872 HasMethodWithOverrideControl = true;
6873 else if (M->size_overridden_methods() > 0)
6874 HasOverridingMethodWithoutOverrideControl = true;
6875 }
6876
6877 if (!isa<CXXDestructorDecl>(M))
6878 CompleteMemberFunction(M);
6879 } else if (auto *F = dyn_cast<FriendDecl>(D)) {
6880 CheckForDefaultedFunction(
6881 dyn_cast_or_null<FunctionDecl>(F->getFriendDecl()));
6882 }
6883 }
6884
6885 if (HasOverridingMethodWithoutOverrideControl) {
6886 bool HasInconsistentOverrideControl = HasMethodWithOverrideControl;
6887 for (auto *M : Record->methods())
6888 DiagnoseAbsenceOfOverrideControl(M, HasInconsistentOverrideControl);
6889 }
6890
6891 // Check the defaulted secondary comparisons after any other member functions.
6892 for (FunctionDecl *FD : DefaultedSecondaryComparisons) {
6893 CheckExplicitlyDefaultedFunction(S, FD);
6894
6895 // If this is a member function, we deferred checking it until now.
6896 if (auto *MD = dyn_cast<CXXMethodDecl>(FD))
6897 CheckCompletedMemberFunction(MD);
6898 }
6899
6900 // ms_struct is a request to use the same ABI rules as MSVC. Check
6901 // whether this class uses any C++ features that are implemented
6902 // completely differently in MSVC, and if so, emit a diagnostic.
6903 // That diagnostic defaults to an error, but we allow projects to
6904 // map it down to a warning (or ignore it). It's a fairly common
6905 // practice among users of the ms_struct pragma to mass-annotate
6906 // headers, sweeping up a bunch of types that the project doesn't
6907 // really rely on MSVC-compatible layout for. We must therefore
6908 // support "ms_struct except for C++ stuff" as a secondary ABI.
6909 // Don't emit this diagnostic if the feature was enabled as a
6910 // language option (as opposed to via a pragma or attribute), as
6911 // the option -mms-bitfields otherwise essentially makes it impossible
6912 // to build C++ code, unless this diagnostic is turned off.
6913 if (Record->isMsStruct(Context) && !Context.getLangOpts().MSBitfields &&
6914 (Record->isPolymorphic() || Record->getNumBases())) {
6915 Diag(Record->getLocation(), diag::warn_cxx_ms_struct);
6916 }
6917
6918 checkClassLevelDLLAttribute(Record);
6919 checkClassLevelCodeSegAttribute(Record);
6920
6921 bool ClangABICompat4 =
6922 Context.getLangOpts().getClangABICompat() <= LangOptions::ClangABI::Ver4;
6923 TargetInfo::CallingConvKind CCK =
6924 Context.getTargetInfo().getCallingConvKind(ClangABICompat4);
6925 bool CanPass = canPassInRegisters(*this, Record, CCK);
6926
6927 // Do not change ArgPassingRestrictions if it has already been set to
6928 // APK_CanNeverPassInRegs.
6929 if (Record->getArgPassingRestrictions() != RecordDecl::APK_CanNeverPassInRegs)
6930 Record->setArgPassingRestrictions(CanPass
6931 ? RecordDecl::APK_CanPassInRegs
6932 : RecordDecl::APK_CannotPassInRegs);
6933
6934 // If canPassInRegisters returns true despite the record having a non-trivial
6935 // destructor, the record is destructed in the callee. This happens only when
6936 // the record or one of its subobjects has a field annotated with trivial_abi
6937 // or a field qualified with ObjC __strong/__weak.
6938 if (Context.getTargetInfo().getCXXABI().areArgsDestroyedLeftToRightInCallee())
6939 Record->setParamDestroyedInCallee(true);
6940 else if (Record->hasNonTrivialDestructor())
6941 Record->setParamDestroyedInCallee(CanPass);
6942
6943 if (getLangOpts().ForceEmitVTables) {
6944 // If we want to emit all the vtables, we need to mark it as used. This
6945 // is especially required for cases like vtable assumption loads.
6946 MarkVTableUsed(Record->getInnerLocStart(), Record);
6947 }
6948
6949 if (getLangOpts().CUDA) {
6950 if (Record->hasAttr<CUDADeviceBuiltinSurfaceTypeAttr>())
6951 checkCUDADeviceBuiltinSurfaceClassTemplate(*this, Record);
6952 else if (Record->hasAttr<CUDADeviceBuiltinTextureTypeAttr>())
6953 checkCUDADeviceBuiltinTextureClassTemplate(*this, Record);
6954 }
6955}
6956
6957/// Look up the special member function that would be called by a special
6958/// member function for a subobject of class type.
6959///
6960/// \param Class The class type of the subobject.
6961/// \param CSM The kind of special member function.
6962/// \param FieldQuals If the subobject is a field, its cv-qualifiers.
6963/// \param ConstRHS True if this is a copy operation with a const object
6964/// on its RHS, that is, if the argument to the outer special member
6965/// function is 'const' and this is not a field marked 'mutable'.
6966static Sema::SpecialMemberOverloadResult lookupCallFromSpecialMember(
6967 Sema &S, CXXRecordDecl *Class, Sema::CXXSpecialMember CSM,
6968 unsigned FieldQuals, bool ConstRHS) {
6969 unsigned LHSQuals = 0;
6970 if (CSM == Sema::CXXCopyAssignment || CSM == Sema::CXXMoveAssignment)
6971 LHSQuals = FieldQuals;
6972
6973 unsigned RHSQuals = FieldQuals;
6974 if (CSM == Sema::CXXDefaultConstructor || CSM == Sema::CXXDestructor)
6975 RHSQuals = 0;
6976 else if (ConstRHS)
6977 RHSQuals |= Qualifiers::Const;
6978
6979 return S.LookupSpecialMember(Class, CSM,
6980 RHSQuals & Qualifiers::Const,
6981 RHSQuals & Qualifiers::Volatile,
6982 false,
6983 LHSQuals & Qualifiers::Const,
6984 LHSQuals & Qualifiers::Volatile);
6985}
6986
6987class Sema::InheritedConstructorInfo {
6988 Sema &S;
6989 SourceLocation UseLoc;
6990
6991 /// A mapping from the base classes through which the constructor was
6992 /// inherited to the using shadow declaration in that base class (or a null
6993 /// pointer if the constructor was declared in that base class).
6994 llvm::DenseMap<CXXRecordDecl *, ConstructorUsingShadowDecl *>
6995 InheritedFromBases;
6996
6997public:
6998 InheritedConstructorInfo(Sema &S, SourceLocation UseLoc,
6999 ConstructorUsingShadowDecl *Shadow)
7000 : S(S), UseLoc(UseLoc) {
7001 bool DiagnosedMultipleConstructedBases = false;
7002 CXXRecordDecl *ConstructedBase = nullptr;
7003 BaseUsingDecl *ConstructedBaseIntroducer = nullptr;
7004
7005 // Find the set of such base class subobjects and check that there's a
7006 // unique constructed subobject.
7007 for (auto *D : Shadow->redecls()) {
7008 auto *DShadow = cast<ConstructorUsingShadowDecl>(D);
7009 auto *DNominatedBase = DShadow->getNominatedBaseClass();
7010 auto *DConstructedBase = DShadow->getConstructedBaseClass();
7011
7012 InheritedFromBases.insert(
7013 std::make_pair(DNominatedBase->getCanonicalDecl(),
7014 DShadow->getNominatedBaseClassShadowDecl()));
7015 if (DShadow->constructsVirtualBase())
7016 InheritedFromBases.insert(
7017 std::make_pair(DConstructedBase->getCanonicalDecl(),
7018 DShadow->getConstructedBaseClassShadowDecl()));
7019 else
7020 assert(DNominatedBase == DConstructedBase)((void)0);
7021
7022 // [class.inhctor.init]p2:
7023 // If the constructor was inherited from multiple base class subobjects
7024 // of type B, the program is ill-formed.
7025 if (!ConstructedBase) {
7026 ConstructedBase = DConstructedBase;
7027 ConstructedBaseIntroducer = D->getIntroducer();
7028 } else if (ConstructedBase != DConstructedBase &&
7029 !Shadow->isInvalidDecl()) {
7030 if (!DiagnosedMultipleConstructedBases) {
7031 S.Diag(UseLoc, diag::err_ambiguous_inherited_constructor)
7032 << Shadow->getTargetDecl();
7033 S.Diag(ConstructedBaseIntroducer->getLocation(),
7034 diag::note_ambiguous_inherited_constructor_using)
7035 << ConstructedBase;
7036 DiagnosedMultipleConstructedBases = true;
7037 }
7038 S.Diag(D->getIntroducer()->getLocation(),
7039 diag::note_ambiguous_inherited_constructor_using)
7040 << DConstructedBase;
7041 }
7042 }
7043
7044 if (DiagnosedMultipleConstructedBases)
7045 Shadow->setInvalidDecl();
7046 }
7047
7048 /// Find the constructor to use for inherited construction of a base class,
7049 /// and whether that base class constructor inherits the constructor from a
7050 /// virtual base class (in which case it won't actually invoke it).
7051 std::pair<CXXConstructorDecl *, bool>
7052 findConstructorForBase(CXXRecordDecl *Base, CXXConstructorDecl *Ctor) const {
7053 auto It = InheritedFromBases.find(Base->getCanonicalDecl());
7054 if (It == InheritedFromBases.end())
7055 return std::make_pair(nullptr, false);
7056
7057 // This is an intermediary class.
7058 if (It->second)
7059 return std::make_pair(
7060 S.findInheritingConstructor(UseLoc, Ctor, It->second),
7061 It->second->constructsVirtualBase());
7062
7063 // This is the base class from which the constructor was inherited.
7064 return std::make_pair(Ctor, false);
7065 }
7066};
7067
7068/// Is the special member function which would be selected to perform the
7069/// specified operation on the specified class type a constexpr constructor?
7070static bool
7071specialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl,
7072 Sema::CXXSpecialMember CSM, unsigned Quals,
7073 bool ConstRHS,
7074 CXXConstructorDecl *InheritedCtor = nullptr,
7075 Sema::InheritedConstructorInfo *Inherited = nullptr) {
7076 // If we're inheriting a constructor, see if we need to call it for this base
7077 // class.
7078 if (InheritedCtor) {
7079 assert(CSM == Sema::CXXDefaultConstructor)((void)0);
7080 auto BaseCtor =
7081 Inherited->findConstructorForBase(ClassDecl, InheritedCtor).first;
7082 if (BaseCtor)
7083 return BaseCtor->isConstexpr();
7084 }
7085
7086 if (CSM == Sema::CXXDefaultConstructor)
7087 return ClassDecl->hasConstexprDefaultConstructor();
7088 if (CSM == Sema::CXXDestructor)
7089 return ClassDecl->hasConstexprDestructor();
7090
7091 Sema::SpecialMemberOverloadResult SMOR =
7092 lookupCallFromSpecialMember(S, ClassDecl, CSM, Quals, ConstRHS);
7093 if (!SMOR.getMethod())
7094 // A constructor we wouldn't select can't be "involved in initializing"
7095 // anything.
7096 return true;
7097 return SMOR.getMethod()->isConstexpr();
7098}
7099
7100/// Determine whether the specified special member function would be constexpr
7101/// if it were implicitly defined.
7102static bool defaultedSpecialMemberIsConstexpr(
7103 Sema &S, CXXRecordDecl *ClassDecl, Sema::CXXSpecialMember CSM,
7104 bool ConstArg, CXXConstructorDecl *InheritedCtor = nullptr,
7105 Sema::InheritedConstructorInfo *Inherited = nullptr) {
7106 if (!S.getLangOpts().CPlusPlus11)
7107 return false;
7108
7109 // C++11 [dcl.constexpr]p4:
7110 // In the definition of a constexpr constructor [...]
7111 bool Ctor = true;
7112 switch (CSM) {
7113 case Sema::CXXDefaultConstructor:
7114 if (Inherited)
7115 break;
7116 // Since default constructor lookup is essentially trivial (and cannot
7117 // involve, for instance, template instantiation), we compute whether a
7118 // defaulted default constructor is constexpr directly within CXXRecordDecl.
7119 //
7120 // This is important for performance; we need to know whether the default
7121 // constructor is constexpr to determine whether the type is a literal type.
7122 return ClassDecl->defaultedDefaultConstructorIsConstexpr();
7123
7124 case Sema::CXXCopyConstructor:
7125 case Sema::CXXMoveConstructor:
7126 // For copy or move constructors, we need to perform overload resolution.
7127 break;
7128
7129 case Sema::CXXCopyAssignment:
7130 case Sema::CXXMoveAssignment:
7131 if (!S.getLangOpts().CPlusPlus14)
7132 return false;
7133 // In C++1y, we need to perform overload resolution.
7134 Ctor = false;
7135 break;
7136
7137 case Sema::CXXDestructor:
7138 return ClassDecl->defaultedDestructorIsConstexpr();
7139
7140 case Sema::CXXInvalid:
7141 return false;
7142 }
7143
7144 // -- if the class is a non-empty union, or for each non-empty anonymous
7145 // union member of a non-union class, exactly one non-static data member
7146 // shall be initialized; [DR1359]
7147 //
7148 // If we squint, this is guaranteed, since exactly one non-static data member
7149 // will be initialized (if the constructor isn't deleted), we just don't know
7150 // which one.
7151 if (Ctor && ClassDecl->isUnion())
7152 return CSM == Sema::CXXDefaultConstructor
7153 ? ClassDecl->hasInClassInitializer() ||
7154 !ClassDecl->hasVariantMembers()
7155 : true;
7156
7157 // -- the class shall not have any virtual base classes;
7158 if (Ctor && ClassDecl->getNumVBases())
7159 return false;
7160
7161 // C++1y [class.copy]p26:
7162 // -- [the class] is a literal type, and
7163 if (!Ctor && !ClassDecl->isLiteral())
7164 return false;
7165
7166 // -- every constructor involved in initializing [...] base class
7167 // sub-objects shall be a constexpr constructor;
7168 // -- the assignment operator selected to copy/move each direct base
7169 // class is a constexpr function, and
7170 for (const auto &B : ClassDecl->bases()) {
7171 const RecordType *BaseType = B.getType()->getAs<RecordType>();
7172 if (!BaseType) continue;
7173
7174 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
7175 if (!specialMemberIsConstexpr(S, BaseClassDecl, CSM, 0, ConstArg,
7176 InheritedCtor, Inherited))
7177 return false;
7178 }
7179
7180 // -- every constructor involved in initializing non-static data members
7181 // [...] shall be a constexpr constructor;
7182 // -- every non-static data member and base class sub-object shall be
7183 // initialized
7184 // -- for each non-static data member of X that is of class type (or array
7185 // thereof), the assignment operator selected to copy/move that member is
7186 // a constexpr function
7187 for (const auto *F : ClassDecl->fields()) {
7188 if (F->isInvalidDecl())
7189 continue;
7190 if (CSM == Sema::CXXDefaultConstructor && F->hasInClassInitializer())
7191 continue;
7192 QualType BaseType = S.Context.getBaseElementType(F->getType());
7193 if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) {
7194 CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
7195 if (!specialMemberIsConstexpr(S, FieldRecDecl, CSM,
7196 BaseType.getCVRQualifiers(),
7197 ConstArg && !F->isMutable()))
7198 return false;
7199 } else if (CSM == Sema::CXXDefaultConstructor) {
7200 return false;
7201 }
7202 }
7203
7204 // All OK, it's constexpr!
7205 return true;
7206}
7207
7208namespace {
7209/// RAII object to register a defaulted function as having its exception
7210/// specification computed.
7211struct ComputingExceptionSpec {
7212 Sema &S;
7213
7214 ComputingExceptionSpec(Sema &S, FunctionDecl *FD, SourceLocation Loc)
7215 : S(S) {
7216 Sema::CodeSynthesisContext Ctx;
7217 Ctx.Kind = Sema::CodeSynthesisContext::ExceptionSpecEvaluation;
7218 Ctx.PointOfInstantiation = Loc;
7219 Ctx.Entity = FD;
7220 S.pushCodeSynthesisContext(Ctx);
7221 }
7222 ~ComputingExceptionSpec() {
7223 S.popCodeSynthesisContext();
7224 }
7225};
7226}
7227
7228static Sema::ImplicitExceptionSpecification
7229ComputeDefaultedSpecialMemberExceptionSpec(
7230 Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
7231 Sema::InheritedConstructorInfo *ICI);
7232
7233static Sema::ImplicitExceptionSpecification
7234ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc,
7235 FunctionDecl *FD,
7236 Sema::DefaultedComparisonKind DCK);
7237
7238static Sema::ImplicitExceptionSpecification
7239computeImplicitExceptionSpec(Sema &S, SourceLocation Loc, FunctionDecl *FD) {
7240 auto DFK = S.getDefaultedFunctionKind(FD);
7241 if (DFK.isSpecialMember())
7242 return ComputeDefaultedSpecialMemberExceptionSpec(
7243 S, Loc, cast<CXXMethodDecl>(FD), DFK.asSpecialMember(), nullptr);
7244 if (DFK.isComparison())
7245 return ComputeDefaultedComparisonExceptionSpec(S, Loc, FD,
7246 DFK.asComparison());
7247
7248 auto *CD = cast<CXXConstructorDecl>(FD);
7249 assert(CD->getInheritedConstructor() &&((void)0)
7250 "only defaulted functions and inherited constructors have implicit "((void)0)
7251 "exception specs")((void)0);
7252 Sema::InheritedConstructorInfo ICI(
7253 S, Loc, CD->getInheritedConstructor().getShadowDecl());
7254 return ComputeDefaultedSpecialMemberExceptionSpec(
7255 S, Loc, CD, Sema::CXXDefaultConstructor, &ICI);
7256}
7257
7258static FunctionProtoType::ExtProtoInfo getImplicitMethodEPI(Sema &S,
7259 CXXMethodDecl *MD) {
7260 FunctionProtoType::ExtProtoInfo EPI;
7261
7262 // Build an exception specification pointing back at this member.
7263 EPI.ExceptionSpec.Type = EST_Unevaluated;
7264 EPI.ExceptionSpec.SourceDecl = MD;
7265
7266 // Set the calling convention to the default for C++ instance methods.
7267 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(
7268 S.Context.getDefaultCallingConvention(/*IsVariadic=*/false,
7269 /*IsCXXMethod=*/true));
7270 return EPI;
7271}
7272
7273void Sema::EvaluateImplicitExceptionSpec(SourceLocation Loc, FunctionDecl *FD) {
7274 const FunctionProtoType *FPT = FD->getType()->castAs<FunctionProtoType>();
7275 if (FPT->getExceptionSpecType() != EST_Unevaluated)
7276 return;
7277
7278 // Evaluate the exception specification.
7279 auto IES = computeImplicitExceptionSpec(*this, Loc, FD);
7280 auto ESI = IES.getExceptionSpec();
7281
7282 // Update the type of the special member to use it.
7283 UpdateExceptionSpec(FD, ESI);
7284}
7285
7286void Sema::CheckExplicitlyDefaultedFunction(Scope *S, FunctionDecl *FD) {
7287 assert(FD->isExplicitlyDefaulted() && "not explicitly-defaulted")((void)0);
7288
7289 DefaultedFunctionKind DefKind = getDefaultedFunctionKind(FD);
7290 if (!DefKind) {
7291 assert(FD->getDeclContext()->isDependentContext())((void)0);
7292 return;
7293 }
7294
7295 if (DefKind.isComparison())
7296 UnusedPrivateFields.clear();
7297
7298 if (DefKind.isSpecialMember()
7299 ? CheckExplicitlyDefaultedSpecialMember(cast<CXXMethodDecl>(FD),
7300 DefKind.asSpecialMember())
7301 : CheckExplicitlyDefaultedComparison(S, FD, DefKind.asComparison()))
7302 FD->setInvalidDecl();
7303}
7304
7305bool Sema::CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD,
7306 CXXSpecialMember CSM) {
7307 CXXRecordDecl *RD = MD->getParent();
7308
7309 assert(MD->isExplicitlyDefaulted() && CSM != CXXInvalid &&((void)0)
7310 "not an explicitly-defaulted special member")((void)0);
7311
7312 // Defer all checking for special members of a dependent type.
7313 if (RD->isDependentType())
7314 return false;
7315
7316 // Whether this was the first-declared instance of the constructor.
7317 // This affects whether we implicitly add an exception spec and constexpr.
7318 bool First = MD == MD->getCanonicalDecl();
7319
7320 bool HadError = false;
7321
7322 // C++11 [dcl.fct.def.default]p1:
7323 // A function that is explicitly defaulted shall
7324 // -- be a special member function [...] (checked elsewhere),
7325 // -- have the same type (except for ref-qualifiers, and except that a
7326 // copy operation can take a non-const reference) as an implicit
7327 // declaration, and
7328 // -- not have default arguments.
7329 // C++2a changes the second bullet to instead delete the function if it's
7330 // defaulted on its first declaration, unless it's "an assignment operator,
7331 // and its return type differs or its parameter type is not a reference".
7332 bool DeleteOnTypeMismatch = getLangOpts().CPlusPlus20 && First;
7333 bool ShouldDeleteForTypeMismatch = false;
7334 unsigned ExpectedParams = 1;
7335 if (CSM == CXXDefaultConstructor || CSM == CXXDestructor)
7336 ExpectedParams = 0;
7337 if (MD->getNumParams() != ExpectedParams) {
7338 // This checks for default arguments: a copy or move constructor with a
7339 // default argument is classified as a default constructor, and assignment
7340 // operations and destructors can't have default arguments.
7341 Diag(MD->getLocation(), diag::err_defaulted_special_member_params)
7342 << CSM << MD->getSourceRange();
7343 HadError = true;
7344 } else if (MD->isVariadic()) {
7345 if (DeleteOnTypeMismatch)
7346 ShouldDeleteForTypeMismatch = true;
7347 else {
7348 Diag(MD->getLocation(), diag::err_defaulted_special_member_variadic)
7349 << CSM << MD->getSourceRange();
7350 HadError = true;
7351 }
7352 }
7353
7354 const FunctionProtoType *Type = MD->getType()->getAs<FunctionProtoType>();
7355
7356 bool CanHaveConstParam = false;
7357 if (CSM == CXXCopyConstructor)
7358 CanHaveConstParam = RD->implicitCopyConstructorHasConstParam();
7359 else if (CSM == CXXCopyAssignment)
7360 CanHaveConstParam = RD->implicitCopyAssignmentHasConstParam();
7361
7362 QualType ReturnType = Context.VoidTy;
7363 if (CSM == CXXCopyAssignment || CSM == CXXMoveAssignment) {
7364 // Check for return type matching.
7365 ReturnType = Type->getReturnType();
7366
7367 QualType DeclType = Context.getTypeDeclType(RD);
7368 DeclType = Context.getAddrSpaceQualType(DeclType, MD->getMethodQualifiers().getAddressSpace());
7369 QualType ExpectedReturnType = Context.getLValueReferenceType(DeclType);
7370
7371 if (!Context.hasSameType(ReturnType, ExpectedReturnType)) {
7372 Diag(MD->getLocation(), diag::err_defaulted_special_member_return_type)
7373 << (CSM == CXXMoveAssignment) << ExpectedReturnType;
7374 HadError = true;
7375 }
7376
7377 // A defaulted special member cannot have cv-qualifiers.
7378 if (Type->getMethodQuals().hasConst() || Type->getMethodQuals().hasVolatile()) {
7379 if (DeleteOnTypeMismatch)
7380 ShouldDeleteForTypeMismatch = true;
7381 else {
7382 Diag(MD->getLocation(), diag::err_defaulted_special_member_quals)
7383 << (CSM == CXXMoveAssignment) << getLangOpts().CPlusPlus14;
7384 HadError = true;
7385 }
7386 }
7387 }
7388
7389 // Check for parameter type matching.
7390 QualType ArgType = ExpectedParams ? Type->getParamType(0) : QualType();
7391 bool HasConstParam = false;
7392 if (ExpectedParams && ArgType->isReferenceType()) {
7393 // Argument must be reference to possibly-const T.
7394 QualType ReferentType = ArgType->getPointeeType();
7395 HasConstParam = ReferentType.isConstQualified();
7396
7397 if (ReferentType.isVolatileQualified()) {
7398 if (DeleteOnTypeMismatch)
7399 ShouldDeleteForTypeMismatch = true;
7400 else {
7401 Diag(MD->getLocation(),
7402 diag::err_defaulted_special_member_volatile_param) << CSM;
7403 HadError = true;
7404 }
7405 }
7406
7407 if (HasConstParam && !CanHaveConstParam) {
7408 if (DeleteOnTypeMismatch)
7409 ShouldDeleteForTypeMismatch = true;
7410 else if (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment) {
7411 Diag(MD->getLocation(),
7412 diag::err_defaulted_special_member_copy_const_param)
7413 << (CSM == CXXCopyAssignment);
7414 // FIXME: Explain why this special member can't be const.
7415 HadError = true;
7416 } else {
7417 Diag(MD->getLocation(),
7418 diag::err_defaulted_special_member_move_const_param)
7419 << (CSM == CXXMoveAssignment);
7420 HadError = true;
7421 }
7422 }
7423 } else if (ExpectedParams) {
7424 // A copy assignment operator can take its argument by value, but a
7425 // defaulted one cannot.
7426 assert(CSM == CXXCopyAssignment && "unexpected non-ref argument")((void)0);
7427 Diag(MD->getLocation(), diag::err_defaulted_copy_assign_not_ref);
7428 HadError = true;
7429 }
7430
7431 // C++11 [dcl.fct.def.default]p2:
7432 // An explicitly-defaulted function may be declared constexpr only if it
7433 // would have been implicitly declared as constexpr,
7434 // Do not apply this rule to members of class templates, since core issue 1358
7435 // makes such functions always instantiate to constexpr functions. For
7436 // functions which cannot be constexpr (for non-constructors in C++11 and for
7437 // destructors in C++14 and C++17), this is checked elsewhere.
7438 //
7439 // FIXME: This should not apply if the member is deleted.
7440 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, RD, CSM,
7441 HasConstParam);
7442 if ((getLangOpts().CPlusPlus20 ||
7443 (getLangOpts().CPlusPlus14 ? !isa<CXXDestructorDecl>(MD)
7444 : isa<CXXConstructorDecl>(MD))) &&
7445 MD->isConstexpr() && !Constexpr &&
7446 MD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) {
7447 Diag(MD->getBeginLoc(), MD->isConsteval()
7448 ? diag::err_incorrect_defaulted_consteval
7449 : diag::err_incorrect_defaulted_constexpr)
7450 << CSM;
7451 // FIXME: Explain why the special member can't be constexpr.
7452 HadError = true;
7453 }
7454
7455 if (First) {
7456 // C++2a [dcl.fct.def.default]p3:
7457 // If a function is explicitly defaulted on its first declaration, it is
7458 // implicitly considered to be constexpr if the implicit declaration
7459 // would be.
7460 MD->setConstexprKind(Constexpr ? (MD->isConsteval()
7461 ? ConstexprSpecKind::Consteval
7462 : ConstexprSpecKind::Constexpr)
7463 : ConstexprSpecKind::Unspecified);
7464
7465 if (!Type->hasExceptionSpec()) {
7466 // C++2a [except.spec]p3:
7467 // If a declaration of a function does not have a noexcept-specifier
7468 // [and] is defaulted on its first declaration, [...] the exception
7469 // specification is as specified below
7470 FunctionProtoType::ExtProtoInfo EPI = Type->getExtProtoInfo();
7471 EPI.ExceptionSpec.Type = EST_Unevaluated;
7472 EPI.ExceptionSpec.SourceDecl = MD;
7473 MD->setType(Context.getFunctionType(ReturnType,
7474 llvm::makeArrayRef(&ArgType,
7475 ExpectedParams),
7476 EPI));
7477 }
7478 }
7479
7480 if (ShouldDeleteForTypeMismatch || ShouldDeleteSpecialMember(MD, CSM)) {
7481 if (First) {
7482 SetDeclDeleted(MD, MD->getLocation());
7483 if (!inTemplateInstantiation() && !HadError) {
7484 Diag(MD->getLocation(), diag::warn_defaulted_method_deleted) << CSM;
7485 if (ShouldDeleteForTypeMismatch) {
7486 Diag(MD->getLocation(), diag::note_deleted_type_mismatch) << CSM;
7487 } else {
7488 ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true);
7489 }
7490 }
7491 if (ShouldDeleteForTypeMismatch && !HadError) {
7492 Diag(MD->getLocation(),
7493 diag::warn_cxx17_compat_defaulted_method_type_mismatch) << CSM;
7494 }
7495 } else {
7496 // C++11 [dcl.fct.def.default]p4:
7497 // [For a] user-provided explicitly-defaulted function [...] if such a
7498 // function is implicitly defined as deleted, the program is ill-formed.
7499 Diag(MD->getLocation(), diag::err_out_of_line_default_deletes) << CSM;
7500 assert(!ShouldDeleteForTypeMismatch && "deleted non-first decl")((void)0);
7501 ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true);
7502 HadError = true;
7503 }
7504 }
7505
7506 return HadError;
7507}
7508
7509namespace {
7510/// Helper class for building and checking a defaulted comparison.
7511///
7512/// Defaulted functions are built in two phases:
7513///
7514/// * First, the set of operations that the function will perform are
7515/// identified, and some of them are checked. If any of the checked
7516/// operations is invalid in certain ways, the comparison function is
7517/// defined as deleted and no body is built.
7518/// * Then, if the function is not defined as deleted, the body is built.
7519///
7520/// This is accomplished by performing two visitation steps over the eventual
7521/// body of the function.
7522template<typename Derived, typename ResultList, typename Result,
7523 typename Subobject>
7524class DefaultedComparisonVisitor {
7525public:
7526 using DefaultedComparisonKind = Sema::DefaultedComparisonKind;
7527
7528 DefaultedComparisonVisitor(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
7529 DefaultedComparisonKind DCK)
7530 : S(S), RD(RD), FD(FD), DCK(DCK) {
7531 if (auto *Info = FD->getDefaultedFunctionInfo()) {
7532 // FIXME: Change CreateOverloadedBinOp to take an ArrayRef instead of an
7533 // UnresolvedSet to avoid this copy.
7534 Fns.assign(Info->getUnqualifiedLookups().begin(),
7535 Info->getUnqualifiedLookups().end());
7536 }
7537 }
7538
7539 ResultList visit() {
7540 // The type of an lvalue naming a parameter of this function.
7541 QualType ParamLvalType =
7542 FD->getParamDecl(0)->getType().getNonReferenceType();
7543
7544 ResultList Results;
7545
7546 switch (DCK) {
7547 case DefaultedComparisonKind::None:
7548 llvm_unreachable("not a defaulted comparison")__builtin_unreachable();
7549
7550 case DefaultedComparisonKind::Equal:
7551 case DefaultedComparisonKind::ThreeWay:
7552 getDerived().visitSubobjects(Results, RD, ParamLvalType.getQualifiers());
7553 return Results;
7554
7555 case DefaultedComparisonKind::NotEqual:
7556 case DefaultedComparisonKind::Relational:
7557 Results.add(getDerived().visitExpandedSubobject(
7558 ParamLvalType, getDerived().getCompleteObject()));
7559 return Results;
7560 }
7561 llvm_unreachable("")__builtin_unreachable();
7562 }
7563
7564protected:
7565 Derived &getDerived() { return static_cast<Derived&>(*this); }
7566
7567 /// Visit the expanded list of subobjects of the given type, as specified in
7568 /// C++2a [class.compare.default].
7569 ///
7570 /// \return \c true if the ResultList object said we're done, \c false if not.
7571 bool visitSubobjects(ResultList &Results, CXXRecordDecl *Record,
7572 Qualifiers Quals) {
7573 // C++2a [class.compare.default]p4:
7574 // The direct base class subobjects of C
7575 for (CXXBaseSpecifier &Base : Record->bases())
7576 if (Results.add(getDerived().visitSubobject(
7577 S.Context.getQualifiedType(Base.getType(), Quals),
7578 getDerived().getBase(&Base))))
7579 return true;
7580
7581 // followed by the non-static data members of C
7582 for (FieldDecl *Field : Record->fields()) {
7583 // Recursively expand anonymous structs.
7584 if (Field->isAnonymousStructOrUnion()) {
7585 if (visitSubobjects(Results, Field->getType()->getAsCXXRecordDecl(),
7586 Quals))
7587 return true;
7588 continue;
7589 }
7590
7591 // Figure out the type of an lvalue denoting this field.
7592 Qualifiers FieldQuals = Quals;
7593 if (Field->isMutable())
7594 FieldQuals.removeConst();
7595 QualType FieldType =
7596 S.Context.getQualifiedType(Field->getType(), FieldQuals);
7597
7598 if (Results.add(getDerived().visitSubobject(
7599 FieldType, getDerived().getField(Field))))
7600 return true;
7601 }
7602
7603 // form a list of subobjects.
7604 return false;
7605 }
7606
7607 Result visitSubobject(QualType Type, Subobject Subobj) {
7608 // In that list, any subobject of array type is recursively expanded
7609 const ArrayType *AT = S.Context.getAsArrayType(Type);
7610 if (auto *CAT = dyn_cast_or_null<ConstantArrayType>(AT))
7611 return getDerived().visitSubobjectArray(CAT->getElementType(),
7612 CAT->getSize(), Subobj);
7613 return getDerived().visitExpandedSubobject(Type, Subobj);
7614 }
7615
7616 Result visitSubobjectArray(QualType Type, const llvm::APInt &Size,
7617 Subobject Subobj) {
7618 return getDerived().visitSubobject(Type, Subobj);
7619 }
7620
7621protected:
7622 Sema &S;
7623 CXXRecordDecl *RD;
7624 FunctionDecl *FD;
7625 DefaultedComparisonKind DCK;
7626 UnresolvedSet<16> Fns;
7627};
7628
7629/// Information about a defaulted comparison, as determined by
7630/// DefaultedComparisonAnalyzer.
7631struct DefaultedComparisonInfo {
7632 bool Deleted = false;
7633 bool Constexpr = true;
7634 ComparisonCategoryType Category = ComparisonCategoryType::StrongOrdering;
7635
7636 static DefaultedComparisonInfo deleted() {
7637 DefaultedComparisonInfo Deleted;
7638 Deleted.Deleted = true;
7639 return Deleted;
7640 }
7641
7642 bool add(const DefaultedComparisonInfo &R) {
7643 Deleted |= R.Deleted;
7644 Constexpr &= R.Constexpr;
7645 Category = commonComparisonType(Category, R.Category);
7646 return Deleted;
7647 }
7648};
7649
7650/// An element in the expanded list of subobjects of a defaulted comparison, as
7651/// specified in C++2a [class.compare.default]p4.
7652struct DefaultedComparisonSubobject {
7653 enum { CompleteObject, Member, Base } Kind;
7654 NamedDecl *Decl;
7655 SourceLocation Loc;
7656};
7657
7658/// A visitor over the notional body of a defaulted comparison that determines
7659/// whether that body would be deleted or constexpr.
7660class DefaultedComparisonAnalyzer
7661 : public DefaultedComparisonVisitor<DefaultedComparisonAnalyzer,
7662 DefaultedComparisonInfo,
7663 DefaultedComparisonInfo,
7664 DefaultedComparisonSubobject> {
7665public:
7666 enum DiagnosticKind { NoDiagnostics, ExplainDeleted, ExplainConstexpr };
7667
7668private:
7669 DiagnosticKind Diagnose;
7670
7671public:
7672 using Base = DefaultedComparisonVisitor;
7673 using Result = DefaultedComparisonInfo;
7674 using Subobject = DefaultedComparisonSubobject;
7675
7676 friend Base;
7677
7678 DefaultedComparisonAnalyzer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
7679 DefaultedComparisonKind DCK,
7680 DiagnosticKind Diagnose = NoDiagnostics)
7681 : Base(S, RD, FD, DCK), Diagnose(Diagnose) {}
7682
7683 Result visit() {
7684 if ((DCK == DefaultedComparisonKind::Equal ||
7685 DCK == DefaultedComparisonKind::ThreeWay) &&
7686 RD->hasVariantMembers()) {
7687 // C++2a [class.compare.default]p2 [P2002R0]:
7688 // A defaulted comparison operator function for class C is defined as
7689 // deleted if [...] C has variant members.
7690 if (Diagnose == ExplainDeleted) {
7691 S.Diag(FD->getLocation(), diag::note_defaulted_comparison_union)
7692 << FD << RD->isUnion() << RD;
7693 }
7694 return Result::deleted();
7695 }
7696
7697 return Base::visit();
7698 }
7699
7700private:
7701 Subobject getCompleteObject() {
7702 return Subobject{Subobject::CompleteObject, RD, FD->getLocation()};
7703 }
7704
7705 Subobject getBase(CXXBaseSpecifier *Base) {
7706 return Subobject{Subobject::Base, Base->getType()->getAsCXXRecordDecl(),
7707 Base->getBaseTypeLoc()};
7708 }
7709
7710 Subobject getField(FieldDecl *Field) {
7711 return Subobject{Subobject::Member, Field, Field->getLocation()};
7712 }
7713
7714 Result visitExpandedSubobject(QualType Type, Subobject Subobj) {
7715 // C++2a [class.compare.default]p2 [P2002R0]:
7716 // A defaulted <=> or == operator function for class C is defined as
7717 // deleted if any non-static data member of C is of reference type
7718 if (Type->isReferenceType()) {
7719 if (Diagnose == ExplainDeleted) {
7720 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_reference_member)
7721 << FD << RD;
7722 }
7723 return Result::deleted();
7724 }
7725
7726 // [...] Let xi be an lvalue denoting the ith element [...]
7727 OpaqueValueExpr Xi(FD->getLocation(), Type, VK_LValue);
7728 Expr *Args[] = {&Xi, &Xi};
7729
7730 // All operators start by trying to apply that same operator recursively.
7731 OverloadedOperatorKind OO = FD->getOverloadedOperator();
7732 assert(OO != OO_None && "not an overloaded operator!")((void)0);
7733 return visitBinaryOperator(OO, Args, Subobj);
7734 }
7735
7736 Result
7737 visitBinaryOperator(OverloadedOperatorKind OO, ArrayRef<Expr *> Args,
7738 Subobject Subobj,
7739 OverloadCandidateSet *SpaceshipCandidates = nullptr) {
7740 // Note that there is no need to consider rewritten candidates here if
7741 // we've already found there is no viable 'operator<=>' candidate (and are
7742 // considering synthesizing a '<=>' from '==' and '<').
7743 OverloadCandidateSet CandidateSet(
7744 FD->getLocation(), OverloadCandidateSet::CSK_Operator,
7745 OverloadCandidateSet::OperatorRewriteInfo(
7746 OO, /*AllowRewrittenCandidates=*/!SpaceshipCandidates));
7747
7748 /// C++2a [class.compare.default]p1 [P2002R0]:
7749 /// [...] the defaulted function itself is never a candidate for overload
7750 /// resolution [...]
7751 CandidateSet.exclude(FD);
7752
7753 if (Args[0]->getType()->isOverloadableType())
7754 S.LookupOverloadedBinOp(CandidateSet, OO, Fns, Args);
7755 else
7756 // FIXME: We determine whether this is a valid expression by checking to
7757 // see if there's a viable builtin operator candidate for it. That isn't
7758 // really what the rules ask us to do, but should give the right results.
7759 S.AddBuiltinOperatorCandidates(OO, FD->getLocation(), Args, CandidateSet);
7760
7761 Result R;
7762
7763 OverloadCandidateSet::iterator Best;
7764 switch (CandidateSet.BestViableFunction(S, FD->getLocation(), Best)) {
7765 case OR_Success: {
7766 // C++2a [class.compare.secondary]p2 [P2002R0]:
7767 // The operator function [...] is defined as deleted if [...] the
7768 // candidate selected by overload resolution is not a rewritten
7769 // candidate.
7770 if ((DCK == DefaultedComparisonKind::NotEqual ||
7771 DCK == DefaultedComparisonKind::Relational) &&
7772 !Best->RewriteKind) {
7773 if (Diagnose == ExplainDeleted) {
7774 S.Diag(Best->Function->getLocation(),
7775 diag::note_defaulted_comparison_not_rewritten_callee)
7776 << FD;
7777 }
7778 return Result::deleted();
7779 }
7780
7781 // Throughout C++2a [class.compare]: if overload resolution does not
7782 // result in a usable function, the candidate function is defined as
7783 // deleted. This requires that we selected an accessible function.
7784 //
7785 // Note that this only considers the access of the function when named
7786 // within the type of the subobject, and not the access path for any
7787 // derived-to-base conversion.
7788 CXXRecordDecl *ArgClass = Args[0]->getType()->getAsCXXRecordDecl();
7789 if (ArgClass && Best->FoundDecl.getDecl() &&
7790 Best->FoundDecl.getDecl()->isCXXClassMember()) {
7791 QualType ObjectType = Subobj.Kind == Subobject::Member
7792 ? Args[0]->getType()
7793 : S.Context.getRecordType(RD);
7794 if (!S.isMemberAccessibleForDeletion(
7795 ArgClass, Best->FoundDecl, ObjectType, Subobj.Loc,
7796 Diagnose == ExplainDeleted
7797 ? S.PDiag(diag::note_defaulted_comparison_inaccessible)
7798 << FD << Subobj.Kind << Subobj.Decl
7799 : S.PDiag()))
7800 return Result::deleted();
7801 }
7802
7803 bool NeedsDeducing =
7804 OO == OO_Spaceship && FD->getReturnType()->isUndeducedAutoType();
7805
7806 if (FunctionDecl *BestFD = Best->Function) {
7807 // C++2a [class.compare.default]p3 [P2002R0]:
7808 // A defaulted comparison function is constexpr-compatible if
7809 // [...] no overlod resolution performed [...] results in a
7810 // non-constexpr function.
7811 assert(!BestFD->isDeleted() && "wrong overload resolution result")((void)0);
7812 // If it's not constexpr, explain why not.
7813 if (Diagnose == ExplainConstexpr && !BestFD->isConstexpr()) {
7814 if (Subobj.Kind != Subobject::CompleteObject)
7815 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_not_constexpr)
7816 << Subobj.Kind << Subobj.Decl;
7817 S.Diag(BestFD->getLocation(),
7818 diag::note_defaulted_comparison_not_constexpr_here);
7819 // Bail out after explaining; we don't want any more notes.
7820 return Result::deleted();
7821 }
7822 R.Constexpr &= BestFD->isConstexpr();
7823
7824 if (NeedsDeducing) {
7825 // If any callee has an undeduced return type, deduce it now.
7826 // FIXME: It's not clear how a failure here should be handled. For
7827 // now, we produce an eager diagnostic, because that is forward
7828 // compatible with most (all?) other reasonable options.
7829 if (BestFD->getReturnType()->isUndeducedType() &&
7830 S.DeduceReturnType(BestFD, FD->getLocation(),
7831 /*Diagnose=*/false)) {
7832 // Don't produce a duplicate error when asked to explain why the
7833 // comparison is deleted: we diagnosed that when initially checking
7834 // the defaulted operator.
7835 if (Diagnose == NoDiagnostics) {
7836 S.Diag(
7837 FD->getLocation(),
7838 diag::err_defaulted_comparison_cannot_deduce_undeduced_auto)
7839 << Subobj.Kind << Subobj.Decl;
7840 S.Diag(
7841 Subobj.Loc,
7842 diag::note_defaulted_comparison_cannot_deduce_undeduced_auto)
7843 << Subobj.Kind << Subobj.Decl;
7844 S.Diag(BestFD->getLocation(),
7845 diag::note_defaulted_comparison_cannot_deduce_callee)
7846 << Subobj.Kind << Subobj.Decl;
7847 }
7848 return Result::deleted();
7849 }
7850 auto *Info = S.Context.CompCategories.lookupInfoForType(
7851 BestFD->getCallResultType());
7852 if (!Info) {
7853 if (Diagnose == ExplainDeleted) {
7854 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_cannot_deduce)
7855 << Subobj.Kind << Subobj.Decl
7856 << BestFD->getCallResultType().withoutLocalFastQualifiers();
7857 S.Diag(BestFD->getLocation(),
7858 diag::note_defaulted_comparison_cannot_deduce_callee)
7859 << Subobj.Kind << Subobj.Decl;
7860 }
7861 return Result::deleted();
7862 }
7863 R.Category = Info->Kind;
7864 }
7865 } else {
7866 QualType T = Best->BuiltinParamTypes[0];
7867 assert(T == Best->BuiltinParamTypes[1] &&((void)0)
7868 "builtin comparison for different types?")((void)0);
7869 assert(Best->BuiltinParamTypes[2].isNull() &&((void)0)
7870 "invalid builtin comparison")((void)0);
7871
7872 if (NeedsDeducing) {
7873 Optional<ComparisonCategoryType> Cat =
7874 getComparisonCategoryForBuiltinCmp(T);
7875 assert(Cat && "no category for builtin comparison?")((void)0);
7876 R.Category = *Cat;
7877 }
7878 }
7879
7880 // Note that we might be rewriting to a different operator. That call is
7881 // not considered until we come to actually build the comparison function.
7882 break;
7883 }
7884
7885 case OR_Ambiguous:
7886 if (Diagnose == ExplainDeleted) {
7887 unsigned Kind = 0;
7888 if (FD->getOverloadedOperator() == OO_Spaceship && OO != OO_Spaceship)
7889 Kind = OO == OO_EqualEqual ? 1 : 2;
7890 CandidateSet.NoteCandidates(
7891 PartialDiagnosticAt(
7892 Subobj.Loc, S.PDiag(diag::note_defaulted_comparison_ambiguous)
7893 << FD << Kind << Subobj.Kind << Subobj.Decl),
7894 S, OCD_AmbiguousCandidates, Args);
7895 }
7896 R = Result::deleted();
7897 break;
7898
7899 case OR_Deleted:
7900 if (Diagnose == ExplainDeleted) {
7901 if ((DCK == DefaultedComparisonKind::NotEqual ||
7902 DCK == DefaultedComparisonKind::Relational) &&
7903 !Best->RewriteKind) {
7904 S.Diag(Best->Function->getLocation(),
7905 diag::note_defaulted_comparison_not_rewritten_callee)
7906 << FD;
7907 } else {
7908 S.Diag(Subobj.Loc,
7909 diag::note_defaulted_comparison_calls_deleted)
7910 << FD << Subobj.Kind << Subobj.Decl;
7911 S.NoteDeletedFunction(Best->Function);
7912 }
7913 }
7914 R = Result::deleted();
7915 break;
7916
7917 case OR_No_Viable_Function:
7918 // If there's no usable candidate, we're done unless we can rewrite a
7919 // '<=>' in terms of '==' and '<'.
7920 if (OO == OO_Spaceship &&
7921 S.Context.CompCategories.lookupInfoForType(FD->getReturnType())) {
7922 // For any kind of comparison category return type, we need a usable
7923 // '==' and a usable '<'.
7924 if (!R.add(visitBinaryOperator(OO_EqualEqual, Args, Subobj,
7925 &CandidateSet)))
7926 R.add(visitBinaryOperator(OO_Less, Args, Subobj, &CandidateSet));
7927 break;
7928 }
7929
7930 if (Diagnose == ExplainDeleted) {
7931 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_no_viable_function)
7932 << FD << Subobj.Kind << Subobj.Decl;
7933
7934 // For a three-way comparison, list both the candidates for the
7935 // original operator and the candidates for the synthesized operator.
7936 if (SpaceshipCandidates) {
7937 SpaceshipCandidates->NoteCandidates(
7938 S, Args,
7939 SpaceshipCandidates->CompleteCandidates(S, OCD_AllCandidates,
7940 Args, FD->getLocation()));
7941 S.Diag(Subobj.Loc,
7942 diag::note_defaulted_comparison_no_viable_function_synthesized)
7943 << (OO == OO_EqualEqual ? 0 : 1);
7944 }
7945
7946 CandidateSet.NoteCandidates(
7947 S, Args,
7948 CandidateSet.CompleteCandidates(S, OCD_AllCandidates, Args,
7949 FD->getLocation()));
7950 }
7951 R = Result::deleted();
7952 break;
7953 }
7954
7955 return R;
7956 }
7957};
7958
7959/// A list of statements.
7960struct StmtListResult {
7961 bool IsInvalid = false;
7962 llvm::SmallVector<Stmt*, 16> Stmts;
7963
7964 bool add(const StmtResult &S) {
7965 IsInvalid |= S.isInvalid();
7966 if (IsInvalid)
7967 return true;
7968 Stmts.push_back(S.get());
7969 return false;
7970 }
7971};
7972
7973/// A visitor over the notional body of a defaulted comparison that synthesizes
7974/// the actual body.
7975class DefaultedComparisonSynthesizer
7976 : public DefaultedComparisonVisitor<DefaultedComparisonSynthesizer,
7977 StmtListResult, StmtResult,
7978 std::pair<ExprResult, ExprResult>> {
7979 SourceLocation Loc;
7980 unsigned ArrayDepth = 0;
7981
7982public:
7983 using Base = DefaultedComparisonVisitor;
7984 using ExprPair = std::pair<ExprResult, ExprResult>;
7985
7986 friend Base;
7987
7988 DefaultedComparisonSynthesizer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
7989 DefaultedComparisonKind DCK,
7990 SourceLocation BodyLoc)
7991 : Base(S, RD, FD, DCK), Loc(BodyLoc) {}
7992
7993 /// Build a suitable function body for this defaulted comparison operator.
7994 StmtResult build() {
7995 Sema::CompoundScopeRAII CompoundScope(S);
7996
7997 StmtListResult Stmts = visit();
7998 if (Stmts.IsInvalid)
7999 return StmtError();
8000
8001 ExprResult RetVal;
8002 switch (DCK) {
8003 case DefaultedComparisonKind::None:
8004 llvm_unreachable("not a defaulted comparison")__builtin_unreachable();
8005
8006 case DefaultedComparisonKind::Equal: {
8007 // C++2a [class.eq]p3:
8008 // [...] compar[e] the corresponding elements [...] until the first
8009 // index i where xi == yi yields [...] false. If no such index exists,
8010 // V is true. Otherwise, V is false.
8011 //
8012 // Join the comparisons with '&&'s and return the result. Use a right
8013 // fold (traversing the conditions right-to-left), because that
8014 // short-circuits more naturally.
8015 auto OldStmts = std::move(Stmts.Stmts);
8016 Stmts.Stmts.clear();
8017 ExprResult CmpSoFar;
8018 // Finish a particular comparison chain.
8019 auto FinishCmp = [&] {
8020 if (Expr *Prior = CmpSoFar.get()) {
8021 // Convert the last expression to 'return ...;'
8022 if (RetVal.isUnset() && Stmts.Stmts.empty())
8023 RetVal = CmpSoFar;
8024 // Convert any prior comparison to 'if (!(...)) return false;'
8025 else if (Stmts.add(buildIfNotCondReturnFalse(Prior)))
8026 return true;
8027 CmpSoFar = ExprResult();
8028 }
8029 return false;
8030 };
8031 for (Stmt *EAsStmt : llvm::reverse(OldStmts)) {
8032 Expr *E = dyn_cast<Expr>(EAsStmt);
8033 if (!E) {
8034 // Found an array comparison.
8035 if (FinishCmp() || Stmts.add(EAsStmt))
8036 return StmtError();
8037 continue;
8038 }
8039
8040 if (CmpSoFar.isUnset()) {
8041 CmpSoFar = E;
8042 continue;
8043 }
8044 CmpSoFar = S.CreateBuiltinBinOp(Loc, BO_LAnd, E, CmpSoFar.get());
8045 if (CmpSoFar.isInvalid())
8046 return StmtError();
8047 }
8048 if (FinishCmp())
8049 return StmtError();
8050 std::reverse(Stmts.Stmts.begin(), Stmts.Stmts.end());
8051 // If no such index exists, V is true.
8052 if (RetVal.isUnset())
8053 RetVal = S.ActOnCXXBoolLiteral(Loc, tok::kw_true);
8054 break;
8055 }
8056
8057 case DefaultedComparisonKind::ThreeWay: {
8058 // Per C++2a [class.spaceship]p3, as a fallback add:
8059 // return static_cast<R>(std::strong_ordering::equal);
8060 QualType StrongOrdering = S.CheckComparisonCategoryType(
8061 ComparisonCategoryType::StrongOrdering, Loc,
8062 Sema::ComparisonCategoryUsage::DefaultedOperator);
8063 if (StrongOrdering.isNull())
8064 return StmtError();
8065 VarDecl *EqualVD = S.Context.CompCategories.getInfoForType(StrongOrdering)
8066 .getValueInfo(ComparisonCategoryResult::Equal)
8067 ->VD;
8068 RetVal = getDecl(EqualVD);
8069 if (RetVal.isInvalid())
8070 return StmtError();
8071 RetVal = buildStaticCastToR(RetVal.get());
8072 break;
8073 }
8074
8075 case DefaultedComparisonKind::NotEqual:
8076 case DefaultedComparisonKind::Relational:
8077 RetVal = cast<Expr>(Stmts.Stmts.pop_back_val());
8078 break;
8079 }
8080
8081 // Build the final return statement.
8082 if (RetVal.isInvalid())
8083 return StmtError();
8084 StmtResult ReturnStmt = S.BuildReturnStmt(Loc, RetVal.get());
8085 if (ReturnStmt.isInvalid())
8086 return StmtError();
8087 Stmts.Stmts.push_back(ReturnStmt.get());
8088
8089 return S.ActOnCompoundStmt(Loc, Loc, Stmts.Stmts, /*IsStmtExpr=*/false);
8090 }
8091
8092private:
8093 ExprResult getDecl(ValueDecl *VD) {
8094 return S.BuildDeclarationNameExpr(
8095 CXXScopeSpec(), DeclarationNameInfo(VD->getDeclName(), Loc), VD);
8096 }
8097
8098 ExprResult getParam(unsigned I) {
8099 ParmVarDecl *PD = FD->getParamDecl(I);
8100 return getDecl(PD);
8101 }
8102
8103 ExprPair getCompleteObject() {
8104 unsigned Param = 0;
8105 ExprResult LHS;
8106 if (isa<CXXMethodDecl>(FD)) {
8107 // LHS is '*this'.
8108 LHS = S.ActOnCXXThis(Loc);
8109 if (!LHS.isInvalid())
8110 LHS = S.CreateBuiltinUnaryOp(Loc, UO_Deref, LHS.get());
8111 } else {
8112 LHS = getParam(Param++);
8113 }
8114 ExprResult RHS = getParam(Param++);
8115 assert(Param == FD->getNumParams())((void)0);
8116 return {LHS, RHS};
8117 }
8118
8119 ExprPair getBase(CXXBaseSpecifier *Base) {
8120 ExprPair Obj = getCompleteObject();
8121 if (Obj.first.isInvalid() || Obj.second.isInvalid())
8122 return {ExprError(), ExprError()};
8123 CXXCastPath Path = {Base};
8124 return {S.ImpCastExprToType(Obj.first.get(), Base->getType(),
8125 CK_DerivedToBase, VK_LValue, &Path),
8126 S.ImpCastExprToType(Obj.second.get(), Base->getType(),
8127 CK_DerivedToBase, VK_LValue, &Path)};
8128 }
8129
8130 ExprPair getField(FieldDecl *Field) {
8131 ExprPair Obj = getCompleteObject();
8132 if (Obj.first.isInvalid() || Obj.second.isInvalid())
8133 return {ExprError(), ExprError()};
8134
8135 DeclAccessPair Found = DeclAccessPair::make(Field, Field->getAccess());
8136 DeclarationNameInfo NameInfo(Field->getDeclName(), Loc);
8137 return {S.BuildFieldReferenceExpr(Obj.first.get(), /*IsArrow=*/false, Loc,
8138 CXXScopeSpec(), Field, Found, NameInfo),
8139 S.BuildFieldReferenceExpr(Obj.second.get(), /*IsArrow=*/false, Loc,
8140 CXXScopeSpec(), Field, Found, NameInfo)};
8141 }
8142
8143 // FIXME: When expanding a subobject, register a note in the code synthesis
8144 // stack to say which subobject we're comparing.
8145
8146 StmtResult buildIfNotCondReturnFalse(ExprResult Cond) {
8147 if (Cond.isInvalid())
8148 return StmtError();
8149
8150 ExprResult NotCond = S.CreateBuiltinUnaryOp(Loc, UO_LNot, Cond.get());
8151 if (NotCond.isInvalid())
8152 return StmtError();
8153
8154 ExprResult False = S.ActOnCXXBoolLiteral(Loc, tok::kw_false);
8155 assert(!False.isInvalid() && "should never fail")((void)0);
8156 StmtResult ReturnFalse = S.BuildReturnStmt(Loc, False.get());
8157 if (ReturnFalse.isInvalid())
8158 return StmtError();
8159
8160 return S.ActOnIfStmt(Loc, false, Loc, nullptr,
8161 S.ActOnCondition(nullptr, Loc, NotCond.get(),
8162 Sema::ConditionKind::Boolean),
8163 Loc, ReturnFalse.get(), SourceLocation(), nullptr);
8164 }
8165
8166 StmtResult visitSubobjectArray(QualType Type, llvm::APInt Size,
8167 ExprPair Subobj) {
8168 QualType SizeType = S.Context.getSizeType();
8169 Size = Size.zextOrTrunc(S.Context.getTypeSize(SizeType));
8170
8171 // Build 'size_t i$n = 0'.
8172 IdentifierInfo *IterationVarName = nullptr;
8173 {
8174 SmallString<8> Str;
8175 llvm::raw_svector_ostream OS(Str);
8176 OS << "i" << ArrayDepth;
8177 IterationVarName = &S.Context.Idents.get(OS.str());
8178 }
8179 VarDecl *IterationVar = VarDecl::Create(
8180 S.Context, S.CurContext, Loc, Loc, IterationVarName, SizeType,
8181 S.Context.getTrivialTypeSourceInfo(SizeType, Loc), SC_None);
8182 llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
8183 IterationVar->setInit(
8184 IntegerLiteral::Create(S.Context, Zero, SizeType, Loc));
8185 Stmt *Init = new (S.Context) DeclStmt(DeclGroupRef(IterationVar), Loc, Loc);
8186
8187 auto IterRef = [&] {
8188 ExprResult Ref = S.BuildDeclarationNameExpr(
8189 CXXScopeSpec(), DeclarationNameInfo(IterationVarName, Loc),
8190 IterationVar);
8191 assert(!Ref.isInvalid() && "can't reference our own variable?")((void)0);
8192 return Ref.get();
8193 };
8194
8195 // Build 'i$n != Size'.
8196 ExprResult Cond = S.CreateBuiltinBinOp(
8197 Loc, BO_NE, IterRef(),
8198 IntegerLiteral::Create(S.Context, Size, SizeType, Loc));
8199 assert(!Cond.isInvalid() && "should never fail")((void)0);
8200
8201 // Build '++i$n'.
8202 ExprResult Inc = S.CreateBuiltinUnaryOp(Loc, UO_PreInc, IterRef());
8203 assert(!Inc.isInvalid() && "should never fail")((void)0);
8204
8205 // Build 'a[i$n]' and 'b[i$n]'.
8206 auto Index = [&](ExprResult E) {
8207 if (E.isInvalid())
8208 return ExprError();
8209 return S.CreateBuiltinArraySubscriptExpr(E.get(), Loc, IterRef(), Loc);
8210 };
8211 Subobj.first = Index(Subobj.first);
8212 Subobj.second = Index(Subobj.second);
8213
8214 // Compare the array elements.
8215 ++ArrayDepth;
8216 StmtResult Substmt = visitSubobject(Type, Subobj);
8217 --ArrayDepth;
8218
8219 if (Substmt.isInvalid())
8220 return StmtError();
8221
8222 // For the inner level of an 'operator==', build 'if (!cmp) return false;'.
8223 // For outer levels or for an 'operator<=>' we already have a suitable
8224 // statement that returns as necessary.
8225 if (Expr *ElemCmp = dyn_cast<Expr>(Substmt.get())) {
8226 assert(DCK == DefaultedComparisonKind::Equal &&((void)0)
8227 "should have non-expression statement")((void)0);
8228 Substmt = buildIfNotCondReturnFalse(ElemCmp);
8229 if (Substmt.isInvalid())
8230 return StmtError();
8231 }
8232
8233 // Build 'for (...) ...'
8234 return S.ActOnForStmt(Loc, Loc, Init,
8235 S.ActOnCondition(nullptr, Loc, Cond.get(),
8236 Sema::ConditionKind::Boolean),
8237 S.MakeFullDiscardedValueExpr(Inc.get()), Loc,
8238 Substmt.get());
8239 }
8240
8241 StmtResult visitExpandedSubobject(QualType Type, ExprPair Obj) {
8242 if (Obj.first.isInvalid() || Obj.second.isInvalid())
8243 return StmtError();
8244
8245 OverloadedOperatorKind OO = FD->getOverloadedOperator();
8246 BinaryOperatorKind Opc = BinaryOperator::getOverloadedOpcode(OO);
8247 ExprResult Op;
8248 if (Type->isOverloadableType())
8249 Op = S.CreateOverloadedBinOp(Loc, Opc, Fns, Obj.first.get(),
8250 Obj.second.get(), /*PerformADL=*/true,
8251 /*AllowRewrittenCandidates=*/true, FD);
8252 else
8253 Op = S.CreateBuiltinBinOp(Loc, Opc, Obj.first.get(), Obj.second.get());
8254 if (Op.isInvalid())
8255 return StmtError();
8256
8257 switch (DCK) {
8258 case DefaultedComparisonKind::None:
8259 llvm_unreachable("not a defaulted comparison")__builtin_unreachable();
8260
8261 case DefaultedComparisonKind::Equal:
8262 // Per C++2a [class.eq]p2, each comparison is individually contextually
8263 // converted to bool.
8264 Op = S.PerformContextuallyConvertToBool(Op.get());
8265 if (Op.isInvalid())
8266 return StmtError();
8267 return Op.get();
8268
8269 case DefaultedComparisonKind::ThreeWay: {
8270 // Per C++2a [class.spaceship]p3, form:
8271 // if (R cmp = static_cast<R>(op); cmp != 0)
8272 // return cmp;
8273 QualType R = FD->getReturnType();
8274 Op = buildStaticCastToR(Op.get());
8275 if (Op.isInvalid())
8276 return StmtError();
8277
8278 // R cmp = ...;
8279 IdentifierInfo *Name = &S.Context.Idents.get("cmp");
8280 VarDecl *VD =
8281 VarDecl::Create(S.Context, S.CurContext, Loc, Loc, Name, R,
8282 S.Context.getTrivialTypeSourceInfo(R, Loc), SC_None);
8283 S.AddInitializerToDecl(VD, Op.get(), /*DirectInit=*/false);
8284 Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(VD), Loc, Loc);
8285
8286 // cmp != 0
8287 ExprResult VDRef = getDecl(VD);
8288 if (VDRef.isInvalid())
8289 return StmtError();
8290 llvm::APInt ZeroVal(S.Context.getIntWidth(S.Context.IntTy), 0);
8291 Expr *Zero =
8292 IntegerLiteral::Create(S.Context, ZeroVal, S.Context.IntTy, Loc);
8293 ExprResult Comp;
8294 if (VDRef.get()->getType()->isOverloadableType())
8295 Comp = S.CreateOverloadedBinOp(Loc, BO_NE, Fns, VDRef.get(), Zero, true,
8296 true, FD);
8297 else
8298 Comp = S.CreateBuiltinBinOp(Loc, BO_NE, VDRef.get(), Zero);
8299 if (Comp.isInvalid())
8300 return StmtError();
8301 Sema::ConditionResult Cond = S.ActOnCondition(
8302 nullptr, Loc, Comp.get(), Sema::ConditionKind::Boolean);
8303 if (Cond.isInvalid())
8304 return StmtError();
8305
8306 // return cmp;
8307 VDRef = getDecl(VD);
8308 if (VDRef.isInvalid())
8309 return StmtError();
8310 StmtResult ReturnStmt = S.BuildReturnStmt(Loc, VDRef.get());
8311 if (ReturnStmt.isInvalid())
8312 return StmtError();
8313
8314 // if (...)
8315 return S.ActOnIfStmt(Loc, /*IsConstexpr=*/false, Loc, InitStmt, Cond, Loc,
8316 ReturnStmt.get(),
8317 /*ElseLoc=*/SourceLocation(), /*Else=*/nullptr);
8318 }
8319
8320 case DefaultedComparisonKind::NotEqual:
8321 case DefaultedComparisonKind::Relational:
8322 // C++2a [class.compare.secondary]p2:
8323 // Otherwise, the operator function yields x @ y.
8324 return Op.get();
8325 }
8326 llvm_unreachable("")__builtin_unreachable();
8327 }
8328
8329 /// Build "static_cast<R>(E)".
8330 ExprResult buildStaticCastToR(Expr *E) {
8331 QualType R = FD->getReturnType();
8332 assert(!R->isUndeducedType() && "type should have been deduced already")((void)0);
8333
8334 // Don't bother forming a no-op cast in the common case.
8335 if (E->isPRValue() && S.Context.hasSameType(E->getType(), R))
8336 return E;
8337 return S.BuildCXXNamedCast(Loc, tok::kw_static_cast,
8338 S.Context.getTrivialTypeSourceInfo(R, Loc), E,
8339 SourceRange(Loc, Loc), SourceRange(Loc, Loc));
8340 }
8341};
8342}
8343
8344/// Perform the unqualified lookups that might be needed to form a defaulted
8345/// comparison function for the given operator.
8346static void lookupOperatorsForDefaultedComparison(Sema &Self, Scope *S,
8347 UnresolvedSetImpl &Operators,
8348 OverloadedOperatorKind Op) {
8349 auto Lookup = [&](OverloadedOperatorKind OO) {
8350 Self.LookupOverloadedOperatorName(OO, S, Operators);
8351 };
8352
8353 // Every defaulted operator looks up itself.
8354 Lookup(Op);
8355 // ... and the rewritten form of itself, if any.
8356 if (OverloadedOperatorKind ExtraOp = getRewrittenOverloadedOperator(Op))
8357 Lookup(ExtraOp);
8358
8359 // For 'operator<=>', we also form a 'cmp != 0' expression, and might
8360 // synthesize a three-way comparison from '<' and '=='. In a dependent
8361 // context, we also need to look up '==' in case we implicitly declare a
8362 // defaulted 'operator=='.
8363 if (Op == OO_Spaceship) {
8364 Lookup(OO_ExclaimEqual);
8365 Lookup(OO_Less);
8366 Lookup(OO_EqualEqual);
8367 }
8368}
8369
8370bool Sema::CheckExplicitlyDefaultedComparison(Scope *S, FunctionDecl *FD,
8371 DefaultedComparisonKind DCK) {
8372 assert(DCK != DefaultedComparisonKind::None && "not a defaulted comparison")((void)0);
8373
8374 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(FD->getLexicalDeclContext());
8375 assert(RD && "defaulted comparison is not defaulted in a class")((void)0);
8376
8377 // Perform any unqualified lookups we're going to need to default this
8378 // function.
8379 if (S) {
8380 UnresolvedSet<32> Operators;
8381 lookupOperatorsForDefaultedComparison(*this, S, Operators,
8382 FD->getOverloadedOperator());
8383 FD->setDefaultedFunctionInfo(FunctionDecl::DefaultedFunctionInfo::Create(
8384 Context, Operators.pairs()));
8385 }
8386
8387 // C++2a [class.compare.default]p1:
8388 // A defaulted comparison operator function for some class C shall be a
8389 // non-template function declared in the member-specification of C that is
8390 // -- a non-static const member of C having one parameter of type
8391 // const C&, or
8392 // -- a friend of C having two parameters of type const C& or two
8393 // parameters of type C.
8394 QualType ExpectedParmType1 = Context.getRecordType(RD);
8395 QualType ExpectedParmType2 =
8396 Context.getLValueReferenceType(ExpectedParmType1.withConst());
8397 if (isa<CXXMethodDecl>(FD))
8398 ExpectedParmType1 = ExpectedParmType2;
8399 for (const ParmVarDecl *Param : FD->parameters()) {
8400 if (!Param->getType()->isDependentType() &&
8401 !Context.hasSameType(Param->getType(), ExpectedParmType1) &&
8402 !Context.hasSameType(Param->getType(), ExpectedParmType2)) {
8403 // Don't diagnose an implicit 'operator=='; we will have diagnosed the
8404 // corresponding defaulted 'operator<=>' already.
8405 if (!FD->isImplicit()) {
8406 Diag(FD->getLocation(), diag::err_defaulted_comparison_param)
8407 << (int)DCK << Param->getType() << ExpectedParmType1
8408 << !isa<CXXMethodDecl>(FD)
8409 << ExpectedParmType2 << Param->getSourceRange();
8410 }
8411 return true;
8412 }
8413 }
8414 if (FD->getNumParams() == 2 &&
8415 !Context.hasSameType(FD->getParamDecl(0)->getType(),
8416 FD->getParamDecl(1)->getType())) {
8417 if (!FD->isImplicit()) {
8418 Diag(FD->getLocation(), diag::err_defaulted_comparison_param_mismatch)
8419 << (int)DCK
8420 << FD->getParamDecl(0)->getType()
8421 << FD->getParamDecl(0)->getSourceRange()
8422 << FD->getParamDecl(1)->getType()
8423 << FD->getParamDecl(1)->getSourceRange();
8424 }
8425 return true;
8426 }
8427
8428 // ... non-static const member ...
8429 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
8430 assert(!MD->isStatic() && "comparison function cannot be a static member")((void)0);
8431 if (!MD->isConst()) {
8432 SourceLocation InsertLoc;
8433 if (FunctionTypeLoc Loc = MD->getFunctionTypeLoc())
8434 InsertLoc = getLocForEndOfToken(Loc.getRParenLoc());
8435 // Don't diagnose an implicit 'operator=='; we will have diagnosed the
8436 // corresponding defaulted 'operator<=>' already.
8437 if (!MD->isImplicit()) {
8438 Diag(MD->getLocation(), diag::err_defaulted_comparison_non_const)
8439 << (int)DCK << FixItHint::CreateInsertion(InsertLoc, " const");
8440 }
8441
8442 // Add the 'const' to the type to recover.
8443 const auto *FPT = MD->getType()->castAs<FunctionProtoType>();
8444 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
8445 EPI.TypeQuals.addConst();
8446 MD->setType(Context.getFunctionType(FPT->getReturnType(),
8447 FPT->getParamTypes(), EPI));
8448 }
8449 } else {
8450 // A non-member function declared in a class must be a friend.
8451 assert(FD->getFriendObjectKind() && "expected a friend declaration")((void)0);
8452 }
8453
8454 // C++2a [class.eq]p1, [class.rel]p1:
8455 // A [defaulted comparison other than <=>] shall have a declared return
8456 // type bool.
8457 if (DCK != DefaultedComparisonKind::ThreeWay &&
8458 !FD->getDeclaredReturnType()->isDependentType() &&
8459 !Context.hasSameType(FD->getDeclaredReturnType(), Context.BoolTy)) {
8460 Diag(FD->getLocation(), diag::err_defaulted_comparison_return_type_not_bool)
8461 << (int)DCK << FD->getDeclaredReturnType() << Context.BoolTy
8462 << FD->getReturnTypeSourceRange();
8463 return true;
8464 }
8465 // C++2a [class.spaceship]p2 [P2002R0]:
8466 // Let R be the declared return type [...]. If R is auto, [...]. Otherwise,
8467 // R shall not contain a placeholder type.
8468 if (DCK == DefaultedComparisonKind::ThreeWay &&
8469 FD->getDeclaredReturnType()->getContainedDeducedType() &&
8470 !Context.hasSameType(FD->getDeclaredReturnType(),
8471 Context.getAutoDeductType())) {
8472 Diag(FD->getLocation(),
8473 diag::err_defaulted_comparison_deduced_return_type_not_auto)
8474 << (int)DCK << FD->getDeclaredReturnType() << Context.AutoDeductTy
8475 << FD->getReturnTypeSourceRange();
8476 return true;
8477 }
8478
8479 // For a defaulted function in a dependent class, defer all remaining checks
8480 // until instantiation.
8481 if (RD->isDependentType())
8482 return false;
8483
8484 // Determine whether the function should be defined as deleted.
8485 DefaultedComparisonInfo Info =
8486 DefaultedComparisonAnalyzer(*this, RD, FD, DCK).visit();
8487
8488 bool First = FD == FD->getCanonicalDecl();
8489
8490 // If we want to delete the function, then do so; there's nothing else to
8491 // check in that case.
8492 if (Info.Deleted) {
8493 if (!First) {
8494 // C++11 [dcl.fct.def.default]p4:
8495 // [For a] user-provided explicitly-defaulted function [...] if such a
8496 // function is implicitly defined as deleted, the program is ill-formed.
8497 //
8498 // This is really just a consequence of the general rule that you can
8499 // only delete a function on its first declaration.
8500 Diag(FD->getLocation(), diag::err_non_first_default_compare_deletes)
8501 << FD->isImplicit() << (int)DCK;
8502 DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
8503 DefaultedComparisonAnalyzer::ExplainDeleted)
8504 .visit();
8505 return true;
8506 }
8507
8508 SetDeclDeleted(FD, FD->getLocation());
8509 if (!inTemplateInstantiation() && !FD->isImplicit()) {
8510 Diag(FD->getLocation(), diag::warn_defaulted_comparison_deleted)
8511 << (int)DCK;
8512 DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
8513 DefaultedComparisonAnalyzer::ExplainDeleted)
8514 .visit();
8515 }
8516 return false;
8517 }
8518
8519 // C++2a [class.spaceship]p2:
8520 // The return type is deduced as the common comparison type of R0, R1, ...
8521 if (DCK == DefaultedComparisonKind::ThreeWay &&
8522 FD->getDeclaredReturnType()->isUndeducedAutoType()) {
8523 SourceLocation RetLoc = FD->getReturnTypeSourceRange().getBegin();
8524 if (RetLoc.isInvalid())
8525 RetLoc = FD->getBeginLoc();
8526 // FIXME: Should we really care whether we have the complete type and the
8527 // 'enumerator' constants here? A forward declaration seems sufficient.
8528 QualType Cat = CheckComparisonCategoryType(
8529 Info.Category, RetLoc, ComparisonCategoryUsage::DefaultedOperator);
8530 if (Cat.isNull())
8531 return true;
8532 Context.adjustDeducedFunctionResultType(
8533 FD, SubstAutoType(FD->getDeclaredReturnType(), Cat));
8534 }
8535
8536 // C++2a [dcl.fct.def.default]p3 [P2002R0]:
8537 // An explicitly-defaulted function that is not defined as deleted may be
8538 // declared constexpr or consteval only if it is constexpr-compatible.
8539 // C++2a [class.compare.default]p3 [P2002R0]:
8540 // A defaulted comparison function is constexpr-compatible if it satisfies
8541 // the requirements for a constexpr function [...]
8542 // The only relevant requirements are that the parameter and return types are
8543 // literal types. The remaining conditions are checked by the analyzer.
8544 if (FD->isConstexpr()) {
8545 if (CheckConstexprReturnType(*this, FD, CheckConstexprKind::Diagnose) &&
8546 CheckConstexprParameterTypes(*this, FD, CheckConstexprKind::Diagnose) &&
8547 !Info.Constexpr) {
8548 Diag(FD->getBeginLoc(),
8549 diag::err_incorrect_defaulted_comparison_constexpr)
8550 << FD->isImplicit() << (int)DCK << FD->isConsteval();
8551 DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
8552 DefaultedComparisonAnalyzer::ExplainConstexpr)
8553 .visit();
8554 }
8555 }
8556
8557 // C++2a [dcl.fct.def.default]p3 [P2002R0]:
8558 // If a constexpr-compatible function is explicitly defaulted on its first
8559 // declaration, it is implicitly considered to be constexpr.
8560 // FIXME: Only applying this to the first declaration seems problematic, as
8561 // simple reorderings can affect the meaning of the program.
8562 if (First && !FD->isConstexpr() && Info.Constexpr)
8563 FD->setConstexprKind(ConstexprSpecKind::Constexpr);
8564
8565 // C++2a [except.spec]p3:
8566 // If a declaration of a function does not have a noexcept-specifier
8567 // [and] is defaulted on its first declaration, [...] the exception
8568 // specification is as specified below
8569 if (FD->getExceptionSpecType() == EST_None) {
8570 auto *FPT = FD->getType()->castAs<FunctionProtoType>();
8571 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
8572 EPI.ExceptionSpec.Type = EST_Unevaluated;
8573 EPI.ExceptionSpec.SourceDecl = FD;
8574 FD->setType(Context.getFunctionType(FPT->getReturnType(),
8575 FPT->getParamTypes(), EPI));
8576 }
8577
8578 return false;
8579}
8580
8581void Sema::DeclareImplicitEqualityComparison(CXXRecordDecl *RD,
8582 FunctionDecl *Spaceship) {
8583 Sema::CodeSynthesisContext Ctx;
8584 Ctx.Kind = Sema::CodeSynthesisContext::DeclaringImplicitEqualityComparison;
8585 Ctx.PointOfInstantiation = Spaceship->getEndLoc();
8586 Ctx.Entity = Spaceship;
8587 pushCodeSynthesisContext(Ctx);
8588
8589 if (FunctionDecl *EqualEqual = SubstSpaceshipAsEqualEqual(RD, Spaceship))
8590 EqualEqual->setImplicit();
8591
8592 popCodeSynthesisContext();
8593}
8594
8595void Sema::DefineDefaultedComparison(SourceLocation UseLoc, FunctionDecl *FD,
8596 DefaultedComparisonKind DCK) {
8597 assert(FD->isDefaulted() && !FD->isDeleted() &&((void)0)
8598 !FD->doesThisDeclarationHaveABody())((void)0);
8599 if (FD->willHaveBody() || FD->isInvalidDecl())
8600 return;
8601
8602 SynthesizedFunctionScope Scope(*this, FD);
8603
8604 // Add a context note for diagnostics produced after this point.
8605 Scope.addContextNote(UseLoc);
8606
8607 {
8608 // Build and set up the function body.
8609 CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getLexicalParent());
8610 SourceLocation BodyLoc =
8611 FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation();
8612 StmtResult Body =
8613 DefaultedComparisonSynthesizer(*this, RD, FD, DCK, BodyLoc).build();
8614 if (Body.isInvalid()) {
8615 FD->setInvalidDecl();
8616 return;
8617 }
8618 FD->setBody(Body.get());
8619 FD->markUsed(Context);
8620 }
8621
8622 // The exception specification is needed because we are defining the
8623 // function. Note that this will reuse the body we just built.
8624 ResolveExceptionSpec(UseLoc, FD->getType()->castAs<FunctionProtoType>());
8625
8626 if (ASTMutationListener *L = getASTMutationListener())
8627 L->CompletedImplicitDefinition(FD);
8628}
8629
8630static Sema::ImplicitExceptionSpecification
8631ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc,
8632 FunctionDecl *FD,
8633 Sema::DefaultedComparisonKind DCK) {
8634 ComputingExceptionSpec CES(S, FD, Loc);
8635 Sema::ImplicitExceptionSpecification ExceptSpec(S);
8636
8637 if (FD->isInvalidDecl())
8638 return ExceptSpec;
8639
8640 // The common case is that we just defined the comparison function. In that
8641 // case, just look at whether the body can throw.
8642 if (FD->hasBody()) {
8643 ExceptSpec.CalledStmt(FD->getBody());
8644 } else {
8645 // Otherwise, build a body so we can check it. This should ideally only
8646 // happen when we're not actually marking the function referenced. (This is
8647 // only really important for efficiency: we don't want to build and throw
8648 // away bodies for comparison functions more than we strictly need to.)
8649
8650 // Pretend to synthesize the function body in an unevaluated context.
8651 // Note that we can't actually just go ahead and define the function here:
8652 // we are not permitted to mark its callees as referenced.
8653 Sema::SynthesizedFunctionScope Scope(S, FD);
8654 EnterExpressionEvaluationContext Context(
8655 S, Sema::ExpressionEvaluationContext::Unevaluated);
8656
8657 CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getLexicalParent());
8658 SourceLocation BodyLoc =
8659 FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation();
8660 StmtResult Body =
8661 DefaultedComparisonSynthesizer(S, RD, FD, DCK, BodyLoc).build();
8662 if (!Body.isInvalid())
8663 ExceptSpec.CalledStmt(Body.get());
8664
8665 // FIXME: Can we hold onto this body and just transform it to potentially
8666 // evaluated when we're asked to define the function rather than rebuilding
8667 // it? Either that, or we should only build the bits of the body that we
8668 // need (the expressions, not the statements).
8669 }
8670
8671 return ExceptSpec;
8672}
8673
8674void Sema::CheckDelayedMemberExceptionSpecs() {
8675 decltype(DelayedOverridingExceptionSpecChecks) Overriding;
8676 decltype(DelayedEquivalentExceptionSpecChecks) Equivalent;
8677
8678 std::swap(Overriding, DelayedOverridingExceptionSpecChecks);
8679 std::swap(Equivalent, DelayedEquivalentExceptionSpecChecks);
8680
8681 // Perform any deferred checking of exception specifications for virtual
8682 // destructors.
8683 for (auto &Check : Overriding)
8684 CheckOverridingFunctionExceptionSpec(Check.first, Check.second);
8685
8686 // Perform any deferred checking of exception specifications for befriended
8687 // special members.
8688 for (auto &Check : Equivalent)
8689 CheckEquivalentExceptionSpec(Check.second, Check.first);
8690}
8691
8692namespace {
8693/// CRTP base class for visiting operations performed by a special member
8694/// function (or inherited constructor).
8695template<typename Derived>
8696struct SpecialMemberVisitor {
8697 Sema &S;
8698 CXXMethodDecl *MD;
8699 Sema::CXXSpecialMember CSM;
8700 Sema::InheritedConstructorInfo *ICI;
8701
8702 // Properties of the special member, computed for convenience.
8703 bool IsConstructor = false, IsAssignment = false, ConstArg = false;
8704
8705 SpecialMemberVisitor(Sema &S, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
8706 Sema::InheritedConstructorInfo *ICI)
8707 : S(S), MD(MD), CSM(CSM), ICI(ICI) {
8708 switch (CSM) {
8709 case Sema::CXXDefaultConstructor:
8710 case Sema::CXXCopyConstructor:
8711 case Sema::CXXMoveConstructor:
8712 IsConstructor = true;
8713 break;
8714 case Sema::CXXCopyAssignment:
8715 case Sema::CXXMoveAssignment:
8716 IsAssignment = true;
8717 break;
8718 case Sema::CXXDestructor:
8719 break;
8720 case Sema::CXXInvalid:
8721 llvm_unreachable("invalid special member kind")__builtin_unreachable();
8722 }
8723
8724 if (MD->getNumParams()) {
8725 if (const ReferenceType *RT =
8726 MD->getParamDecl(0)->getType()->getAs<ReferenceType>())
8727 ConstArg = RT->getPointeeType().isConstQualified();
8728 }
8729 }
8730
8731 Derived &getDerived() { return static_cast<Derived&>(*this); }
8732
8733 /// Is this a "move" special member?
8734 bool isMove() const {
8735 return CSM == Sema::CXXMoveConstructor || CSM == Sema::CXXMoveAssignment;
8736 }
8737
8738 /// Look up the corresponding special member in the given class.
8739 Sema::SpecialMemberOverloadResult lookupIn(CXXRecordDecl *Class,
8740 unsigned Quals, bool IsMutable) {
8741 return lookupCallFromSpecialMember(S, Class, CSM, Quals,
8742 ConstArg && !IsMutable);
8743 }
8744
8745 /// Look up the constructor for the specified base class to see if it's
8746 /// overridden due to this being an inherited constructor.
8747 Sema::SpecialMemberOverloadResult lookupInheritedCtor(CXXRecordDecl *Class) {
8748 if (!ICI)
8749 return {};
8750 assert(CSM == Sema::CXXDefaultConstructor)((void)0);
8751 auto *BaseCtor =
8752 cast<CXXConstructorDecl>(MD)->getInheritedConstructor().getConstructor();
8753 if (auto *MD = ICI->findConstructorForBase(Class, BaseCtor).first)
8754 return MD;
8755 return {};
8756 }
8757
8758 /// A base or member subobject.
8759 typedef llvm::PointerUnion<CXXBaseSpecifier*, FieldDecl*> Subobject;
8760
8761 /// Get the location to use for a subobject in diagnostics.
8762 static SourceLocation getSubobjectLoc(Subobject Subobj) {
8763 // FIXME: For an indirect virtual base, the direct base leading to
8764 // the indirect virtual base would be a more useful choice.
8765 if (auto *B = Subobj.dyn_cast<CXXBaseSpecifier*>())
8766 return B->getBaseTypeLoc();
8767 else
8768 return Subobj.get<FieldDecl*>()->getLocation();
8769 }
8770
8771 enum BasesToVisit {
8772 /// Visit all non-virtual (direct) bases.
8773 VisitNonVirtualBases,
8774 /// Visit all direct bases, virtual or not.
8775 VisitDirectBases,
8776 /// Visit all non-virtual bases, and all virtual bases if the class
8777 /// is not abstract.
8778 VisitPotentiallyConstructedBases,
8779 /// Visit all direct or virtual bases.
8780 VisitAllBases
8781 };
8782
8783 // Visit the bases and members of the class.
8784 bool visit(BasesToVisit Bases) {
8785 CXXRecordDecl *RD = MD->getParent();
8786
8787 if (Bases == VisitPotentiallyConstructedBases)
8788 Bases = RD->isAbstract() ? VisitNonVirtualBases : VisitAllBases;
8789
8790 for (auto &B : RD->bases())
8791 if ((Bases == VisitDirectBases || !B.isVirtual()) &&
8792 getDerived().visitBase(&B))
8793 return true;
8794
8795 if (Bases == VisitAllBases)
8796 for (auto &B : RD->vbases())
8797 if (getDerived().visitBase(&B))
8798 return true;
8799
8800 for (auto *F : RD->fields())
8801 if (!F->isInvalidDecl() && !F->isUnnamedBitfield() &&
8802 getDerived().visitField(F))
8803 return true;
8804
8805 return false;
8806 }
8807};
8808}
8809
8810namespace {
8811struct SpecialMemberDeletionInfo
8812 : SpecialMemberVisitor<SpecialMemberDeletionInfo> {
8813 bool Diagnose;
8814
8815 SourceLocation Loc;
8816
8817 bool AllFieldsAreConst;
8818
8819 SpecialMemberDeletionInfo(Sema &S, CXXMethodDecl *MD,
8820 Sema::CXXSpecialMember CSM,
8821 Sema::InheritedConstructorInfo *ICI, bool Diagnose)
8822 : SpecialMemberVisitor(S, MD, CSM, ICI), Diagnose(Diagnose),
8823 Loc(MD->getLocation()), AllFieldsAreConst(true) {}
8824
8825 bool inUnion() const { return MD->getParent()->isUnion(); }
8826
8827 Sema::CXXSpecialMember getEffectiveCSM() {
8828 return ICI ? Sema::CXXInvalid : CSM;
8829 }
8830
8831 bool shouldDeleteForVariantObjCPtrMember(FieldDecl *FD, QualType FieldType);
8832
8833 bool visitBase(CXXBaseSpecifier *Base) { return shouldDeleteForBase(Base); }
8834 bool visitField(FieldDecl *Field) { return shouldDeleteForField(Field); }
8835
8836 bool shouldDeleteForBase(CXXBaseSpecifier *Base);
8837 bool shouldDeleteForField(FieldDecl *FD);
8838 bool shouldDeleteForAllConstMembers();
8839
8840 bool shouldDeleteForClassSubobject(CXXRecordDecl *Class, Subobject Subobj,
8841 unsigned Quals);
8842 bool shouldDeleteForSubobjectCall(Subobject Subobj,
8843 Sema::SpecialMemberOverloadResult SMOR,
8844 bool IsDtorCallInCtor);
8845
8846 bool isAccessible(Subobject Subobj, CXXMethodDecl *D);
8847};
8848}
8849
8850/// Is the given special member inaccessible when used on the given
8851/// sub-object.
8852bool SpecialMemberDeletionInfo::isAccessible(Subobject Subobj,
8853 CXXMethodDecl *target) {
8854 /// If we're operating on a base class, the object type is the
8855 /// type of this special member.
8856 QualType objectTy;
8857 AccessSpecifier access = target->getAccess();
8858 if (CXXBaseSpecifier *base = Subobj.dyn_cast<CXXBaseSpecifier*>()) {
8859 objectTy = S.Context.getTypeDeclType(MD->getParent());
8860 access = CXXRecordDecl::MergeAccess(base->getAccessSpecifier(), access);
8861
8862 // If we're operating on a field, the object type is the type of the field.
8863 } else {
8864 objectTy = S.Context.getTypeDeclType(target->getParent());
8865 }
8866
8867 return S.isMemberAccessibleForDeletion(
8868 target->getParent(), DeclAccessPair::make(target, access), objectTy);
8869}
8870
8871/// Check whether we should delete a special member due to the implicit
8872/// definition containing a call to a special member of a subobject.
8873bool SpecialMemberDeletionInfo::shouldDeleteForSubobjectCall(
8874 Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR,
8875 bool IsDtorCallInCtor) {
8876 CXXMethodDecl *Decl = SMOR.getMethod();
8877 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
8878
8879 int DiagKind = -1;
8880
8881 if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::NoMemberOrDeleted)
8882 DiagKind = !Decl ? 0 : 1;
8883 else if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
8884 DiagKind = 2;
8885 else if (!isAccessible(Subobj, Decl))
8886 DiagKind = 3;
8887 else if (!IsDtorCallInCtor && Field && Field->getParent()->isUnion() &&
8888 !Decl->isTrivial()) {
8889 // A member of a union must have a trivial corresponding special member.
8890 // As a weird special case, a destructor call from a union's constructor
8891 // must be accessible and non-deleted, but need not be trivial. Such a
8892 // destructor is never actually called, but is semantically checked as
8893 // if it were.
8894 DiagKind = 4;
8895 }
8896
8897 if (DiagKind == -1)
8898 return false;
8899
8900 if (Diagnose) {
8901 if (Field) {
8902 S.Diag(Field->getLocation(),
8903 diag::note_deleted_special_member_class_subobject)
8904 << getEffectiveCSM() << MD->getParent() << /*IsField*/true
8905 << Field << DiagKind << IsDtorCallInCtor << /*IsObjCPtr*/false;
8906 } else {
8907 CXXBaseSpecifier *Base = Subobj.get<CXXBaseSpecifier*>();
8908 S.Diag(Base->getBeginLoc(),
8909 diag::note_deleted_special_member_class_subobject)
8910 << getEffectiveCSM() << MD->getParent() << /*IsField*/ false
8911 << Base->getType() << DiagKind << IsDtorCallInCtor
8912 << /*IsObjCPtr*/false;
8913 }
8914
8915 if (DiagKind == 1)
8916 S.NoteDeletedFunction(Decl);
8917 // FIXME: Explain inaccessibility if DiagKind == 3.
8918 }
8919
8920 return true;
8921}
8922
8923/// Check whether we should delete a special member function due to having a
8924/// direct or virtual base class or non-static data member of class type M.
8925bool SpecialMemberDeletionInfo::shouldDeleteForClassSubobject(
8926 CXXRecordDecl *Class, Subobject Subobj, unsigned Quals) {
8927 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
8928 bool IsMutable = Field && Field->isMutable();
8929
8930 // C++11 [class.ctor]p5:
8931 // -- any direct or virtual base class, or non-static data member with no
8932 // brace-or-equal-initializer, has class type M (or array thereof) and
8933 // either M has no default constructor or overload resolution as applied
8934 // to M's default constructor results in an ambiguity or in a function
8935 // that is deleted or inaccessible
8936 // C++11 [class.copy]p11, C++11 [class.copy]p23:
8937 // -- a direct or virtual base class B that cannot be copied/moved because
8938 // overload resolution, as applied to B's corresponding special member,
8939 // results in an ambiguity or a function that is deleted or inaccessible
8940 // from the defaulted special member
8941 // C++11 [class.dtor]p5:
8942 // -- any direct or virtual base class [...] has a type with a destructor
8943 // that is deleted or inaccessible
8944 if (!(CSM == Sema::CXXDefaultConstructor &&
8945 Field && Field->hasInClassInitializer()) &&
8946 shouldDeleteForSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable),
8947 false))
8948 return true;
8949
8950 // C++11 [class.ctor]p5, C++11 [class.copy]p11:
8951 // -- any direct or virtual base class or non-static data member has a
8952 // type with a destructor that is deleted or inaccessible
8953 if (IsConstructor) {
8954 Sema::SpecialMemberOverloadResult SMOR =
8955 S.LookupSpecialMember(Class, Sema::CXXDestructor,
8956 false, false, false, false, false);
8957 if (shouldDeleteForSubobjectCall(Subobj, SMOR, true))
8958 return true;
8959 }
8960
8961 return false;
8962}
8963
8964bool SpecialMemberDeletionInfo::shouldDeleteForVariantObjCPtrMember(
8965 FieldDecl *FD, QualType FieldType) {
8966 // The defaulted special functions are defined as deleted if this is a variant
8967 // member with a non-trivial ownership type, e.g., ObjC __strong or __weak
8968 // type under ARC.
8969 if (!FieldType.hasNonTrivialObjCLifetime())
8970 return false;
8971
8972 // Don't make the defaulted default constructor defined as deleted if the
8973 // member has an in-class initializer.
8974 if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer())
8975 return false;
8976
8977 if (Diagnose) {
8978 auto *ParentClass = cast<CXXRecordDecl>(FD->getParent());
8979 S.Diag(FD->getLocation(),
8980 diag::note_deleted_special_member_class_subobject)
8981 << getEffectiveCSM() << ParentClass << /*IsField*/true
8982 << FD << 4 << /*IsDtorCallInCtor*/false << /*IsObjCPtr*/true;
8983 }
8984
8985 return true;
8986}
8987
8988/// Check whether we should delete a special member function due to the class
8989/// having a particular direct or virtual base class.
8990bool SpecialMemberDeletionInfo::shouldDeleteForBase(CXXBaseSpecifier *Base) {
8991 CXXRecordDecl *BaseClass = Base->getType()->getAsCXXRecordDecl();
8992 // If program is correct, BaseClass cannot be null, but if it is, the error
8993 // must be reported elsewhere.
8994 if (!BaseClass)
8995 return false;
8996 // If we have an inheriting constructor, check whether we're calling an
8997 // inherited constructor instead of a default constructor.
8998 Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass);
8999 if (auto *BaseCtor = SMOR.getMethod()) {
9000 // Note that we do not check access along this path; other than that,
9001 // this is the same as shouldDeleteForSubobjectCall(Base, BaseCtor, false);
9002 // FIXME: Check that the base has a usable destructor! Sink this into
9003 // shouldDeleteForClassSubobject.
9004 if (BaseCtor->isDeleted() && Diagnose) {
9005 S.Diag(Base->getBeginLoc(),
9006 diag::note_deleted_special_member_class_subobject)
9007 << getEffectiveCSM() << MD->getParent() << /*IsField*/ false
9008 << Base->getType() << /*Deleted*/ 1 << /*IsDtorCallInCtor*/ false
9009 << /*IsObjCPtr*/false;
9010 S.NoteDeletedFunction(BaseCtor);
9011 }
9012 return BaseCtor->isDeleted();
9013 }
9014 return shouldDeleteForClassSubobject(BaseClass, Base, 0);
9015}
9016
9017/// Check whether we should delete a special member function due to the class
9018/// having a particular non-static data member.
9019bool SpecialMemberDeletionInfo::shouldDeleteForField(FieldDecl *FD) {
9020 QualType FieldType = S.Context.getBaseElementType(FD->getType());
9021 CXXRecordDecl *FieldRecord = FieldType->getAsCXXRecordDecl();
9022
9023 if (inUnion() && shouldDeleteForVariantObjCPtrMember(FD, FieldType))
9024 return true;
9025
9026 if (CSM == Sema::CXXDefaultConstructor) {
9027 // For a default constructor, all references must be initialized in-class
9028 // and, if a union, it must have a non-const member.
9029 if (FieldType->isReferenceType() && !FD->hasInClassInitializer()) {
9030 if (Diagnose)
9031 S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
9032 << !!ICI << MD->getParent() << FD << FieldType << /*Reference*/0;
9033 return true;
9034 }
9035 // C++11 [class.ctor]p5: any non-variant non-static data member of
9036 // const-qualified type (or array thereof) with no
9037 // brace-or-equal-initializer does not have a user-provided default
9038 // constructor.
9039 if (!inUnion() && FieldType.isConstQualified() &&
9040 !FD->hasInClassInitializer() &&
9041 (!FieldRecord || !FieldRecord->hasUserProvidedDefaultConstructor())) {
9042 if (Diagnose)
9043 S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
9044 << !!ICI << MD->getParent() << FD << FD->getType() << /*Const*/1;
9045 return true;
9046 }
9047
9048 if (inUnion() && !FieldType.isConstQualified())
9049 AllFieldsAreConst = false;
9050 } else if (CSM == Sema::CXXCopyConstructor) {
9051 // For a copy constructor, data members must not be of rvalue reference
9052 // type.
9053 if (FieldType->isRValueReferenceType()) {
9054 if (Diagnose)
9055 S.Diag(FD->getLocation(), diag::note_deleted_copy_ctor_rvalue_reference)
9056 << MD->getParent() << FD << FieldType;
9057 return true;
9058 }
9059 } else if (IsAssignment) {
9060 // For an assignment operator, data members must not be of reference type.
9061 if (FieldType->isReferenceType()) {
9062 if (Diagnose)
9063 S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
9064 << isMove() << MD->getParent() << FD << FieldType << /*Reference*/0;
9065 return true;
9066 }
9067 if (!FieldRecord && FieldType.isConstQualified()) {
9068 // C++11 [class.copy]p23:
9069 // -- a non-static data member of const non-class type (or array thereof)
9070 if (Diagnose)
9071 S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
9072 << isMove() << MD->getParent() << FD << FD->getType() << /*Const*/1;
9073 return true;
9074 }
9075 }
9076
9077 if (FieldRecord) {
9078 // Some additional restrictions exist on the variant members.
9079 if (!inUnion() && FieldRecord->isUnion() &&
9080 FieldRecord->isAnonymousStructOrUnion()) {
9081 bool AllVariantFieldsAreConst = true;
9082
9083 // FIXME: Handle anonymous unions declared within anonymous unions.
9084 for (auto *UI : FieldRecord->fields()) {
9085 QualType UnionFieldType = S.Context.getBaseElementType(UI->getType());
9086
9087 if (shouldDeleteForVariantObjCPtrMember(&*UI, UnionFieldType))
9088 return true;
9089
9090 if (!UnionFieldType.isConstQualified())
9091 AllVariantFieldsAreConst = false;
9092
9093 CXXRecordDecl *UnionFieldRecord = UnionFieldType->getAsCXXRecordDecl();
9094 if (UnionFieldRecord &&
9095 shouldDeleteForClassSubobject(UnionFieldRecord, UI,
9096 UnionFieldType.getCVRQualifiers()))
9097 return true;
9098 }
9099
9100 // At least one member in each anonymous union must be non-const
9101 if (CSM == Sema::CXXDefaultConstructor && AllVariantFieldsAreConst &&
9102 !FieldRecord->field_empty()) {
9103 if (Diagnose)
9104 S.Diag(FieldRecord->getLocation(),
9105 diag::note_deleted_default_ctor_all_const)
9106 << !!ICI << MD->getParent() << /*anonymous union*/1;
9107 return true;
9108 }
9109
9110 // Don't check the implicit member of the anonymous union type.
9111 // This is technically non-conformant, but sanity demands it.
9112 return false;
9113 }
9114
9115 if (shouldDeleteForClassSubobject(FieldRecord, FD,
9116 FieldType.getCVRQualifiers()))
9117 return true;
9118 }
9119
9120 return false;
9121}
9122
9123/// C++11 [class.ctor] p5:
9124/// A defaulted default constructor for a class X is defined as deleted if
9125/// X is a union and all of its variant members are of const-qualified type.
9126bool SpecialMemberDeletionInfo::shouldDeleteForAllConstMembers() {
9127 // This is a silly definition, because it gives an empty union a deleted
9128 // default constructor. Don't do that.
9129 if (CSM == Sema::CXXDefaultConstructor && inUnion() && AllFieldsAreConst) {
9130 bool AnyFields = false;
9131 for (auto *F : MD->getParent()->fields())
9132 if ((AnyFields = !F->isUnnamedBitfield()))
9133 break;
9134 if (!AnyFields)
9135 return false;
9136 if (Diagnose)
9137 S.Diag(MD->getParent()->getLocation(),
9138 diag::note_deleted_default_ctor_all_const)
9139 << !!ICI << MD->getParent() << /*not anonymous union*/0;
9140 return true;
9141 }
9142 return false;
9143}
9144
9145/// Determine whether a defaulted special member function should be defined as
9146/// deleted, as specified in C++11 [class.ctor]p5, C++11 [class.copy]p11,
9147/// C++11 [class.copy]p23, and C++11 [class.dtor]p5.
9148bool Sema::ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM,
9149 InheritedConstructorInfo *ICI,
9150 bool Diagnose) {
9151 if (MD->isInvalidDecl())
9152 return false;
9153 CXXRecordDecl *RD = MD->getParent();
9154 assert(!RD->isDependentType() && "do deletion after instantiation")((void)0);
9155 if (!LangOpts.CPlusPlus11 || RD->isInvalidDecl())
9156 return false;
9157
9158 // C++11 [expr.lambda.prim]p19:
9159 // The closure type associated with a lambda-expression has a
9160 // deleted (8.4.3) default constructor and a deleted copy
9161 // assignment operator.
9162 // C++2a adds back these operators if the lambda has no lambda-capture.
9163 if (RD->isLambda() && !RD->lambdaIsDefaultConstructibleAndAssignable() &&
9164 (CSM == CXXDefaultConstructor || CSM == CXXCopyAssignment)) {
9165 if (Diagnose)
9166 Diag(RD->getLocation(), diag::note_lambda_decl);
9167 return true;
9168 }
9169
9170 // For an anonymous struct or union, the copy and assignment special members
9171 // will never be used, so skip the check. For an anonymous union declared at
9172 // namespace scope, the constructor and destructor are used.
9173 if (CSM != CXXDefaultConstructor && CSM != CXXDestructor &&
9174 RD->isAnonymousStructOrUnion())
9175 return false;
9176
9177 // C++11 [class.copy]p7, p18:
9178 // If the class definition declares a move constructor or move assignment
9179 // operator, an implicitly declared copy constructor or copy assignment
9180 // operator is defined as deleted.
9181 if (MD->isImplicit() &&
9182 (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment)) {
9183 CXXMethodDecl *UserDeclaredMove = nullptr;
9184
9185 // In Microsoft mode up to MSVC 2013, a user-declared move only causes the
9186 // deletion of the corresponding copy operation, not both copy operations.
9187 // MSVC 2015 has adopted the standards conforming behavior.
9188 bool DeletesOnlyMatchingCopy =
9189 getLangOpts().MSVCCompat &&
9190 !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015);
9191
9192 if (RD->hasUserDeclaredMoveConstructor() &&
9193 (!DeletesOnlyMatchingCopy || CSM == CXXCopyConstructor)) {
9194 if (!Diagnose) return true;
9195
9196 // Find any user-declared move constructor.
9197 for (auto *I : RD->ctors()) {
9198 if (I->isMoveConstructor()) {
9199 UserDeclaredMove = I;
9200 break;
9201 }
9202 }
9203 assert(UserDeclaredMove)((void)0);
9204 } else if (RD->hasUserDeclaredMoveAssignment() &&
9205 (!DeletesOnlyMatchingCopy || CSM == CXXCopyAssignment)) {
9206 if (!Diagnose) return true;
9207
9208 // Find any user-declared move assignment operator.
9209 for (auto *I : RD->methods()) {
9210 if (I->isMoveAssignmentOperator()) {
9211 UserDeclaredMove = I;
9212 break;
9213 }
9214 }
9215 assert(UserDeclaredMove)((void)0);
9216 }
9217
9218 if (UserDeclaredMove) {
9219 Diag(UserDeclaredMove->getLocation(),
9220 diag::note_deleted_copy_user_declared_move)
9221 << (CSM == CXXCopyAssignment) << RD
9222 << UserDeclaredMove->isMoveAssignmentOperator();
9223 return true;
9224 }
9225 }
9226
9227 // Do access control from the special member function
9228 ContextRAII MethodContext(*this, MD);
9229
9230 // C++11 [class.dtor]p5:
9231 // -- for a virtual destructor, lookup of the non-array deallocation function
9232 // results in an ambiguity or in a function that is deleted or inaccessible
9233 if (CSM == CXXDestructor && MD->isVirtual()) {
9234 FunctionDecl *OperatorDelete = nullptr;
9235 DeclarationName Name =
9236 Context.DeclarationNames.getCXXOperatorName(OO_Delete);
9237 if (FindDeallocationFunction(MD->getLocation(), MD->getParent(), Name,
9238 OperatorDelete, /*Diagnose*/false)) {
9239 if (Diagnose)
9240 Diag(RD->getLocation(), diag::note_deleted_dtor_no_operator_delete);
9241 return true;
9242 }
9243 }
9244
9245 SpecialMemberDeletionInfo SMI(*this, MD, CSM, ICI, Diagnose);
9246
9247 // Per DR1611, do not consider virtual bases of constructors of abstract
9248 // classes, since we are not going to construct them.
9249 // Per DR1658, do not consider virtual bases of destructors of abstract
9250 // classes either.
9251 // Per DR2180, for assignment operators we only assign (and thus only
9252 // consider) direct bases.
9253 if (SMI.visit(SMI.IsAssignment ? SMI.VisitDirectBases
9254 : SMI.VisitPotentiallyConstructedBases))
9255 return true;
9256
9257 if (SMI.shouldDeleteForAllConstMembers())
9258 return true;
9259
9260 if (getLangOpts().CUDA) {
9261 // We should delete the special member in CUDA mode if target inference
9262 // failed.
9263 // For inherited constructors (non-null ICI), CSM may be passed so that MD
9264 // is treated as certain special member, which may not reflect what special
9265 // member MD really is. However inferCUDATargetForImplicitSpecialMember
9266 // expects CSM to match MD, therefore recalculate CSM.
9267 assert(ICI || CSM == getSpecialMember(MD))((void)0);
9268 auto RealCSM = CSM;
9269 if (ICI)
9270 RealCSM = getSpecialMember(MD);
9271
9272 return inferCUDATargetForImplicitSpecialMember(RD, RealCSM, MD,
9273 SMI.ConstArg, Diagnose);
9274 }
9275
9276 return false;
9277}
9278
9279void Sema::DiagnoseDeletedDefaultedFunction(FunctionDecl *FD) {
9280 DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD);
9281 assert(DFK && "not a defaultable function")((void)0);
9282 assert(FD->isDefaulted() && FD->isDeleted() && "not defaulted and deleted")((void)0);
9283
9284 if (DFK.isSpecialMember()) {
9285 ShouldDeleteSpecialMember(cast<CXXMethodDecl>(FD), DFK.asSpecialMember(),
9286 nullptr, /*Diagnose=*/true);
9287 } else {
9288 DefaultedComparisonAnalyzer(
9289 *this, cast<CXXRecordDecl>(FD->getLexicalDeclContext()), FD,
9290 DFK.asComparison(), DefaultedComparisonAnalyzer::ExplainDeleted)
9291 .visit();
9292 }
9293}
9294
9295/// Perform lookup for a special member of the specified kind, and determine
9296/// whether it is trivial. If the triviality can be determined without the
9297/// lookup, skip it. This is intended for use when determining whether a
9298/// special member of a containing object is trivial, and thus does not ever
9299/// perform overload resolution for default constructors.
9300///
9301/// If \p Selected is not \c NULL, \c *Selected will be filled in with the
9302/// member that was most likely to be intended to be trivial, if any.
9303///
9304/// If \p ForCall is true, look at CXXRecord::HasTrivialSpecialMembersForCall to
9305/// determine whether the special member is trivial.
9306static bool findTrivialSpecialMember(Sema &S, CXXRecordDecl *RD,
9307 Sema::CXXSpecialMember CSM, unsigned Quals,
9308 bool ConstRHS,
9309 Sema::TrivialABIHandling TAH,
9310 CXXMethodDecl **Selected) {
9311 if (Selected)
9312 *Selected = nullptr;
9313
9314 switch (CSM) {
9315 case Sema::CXXInvalid:
9316 llvm_unreachable("not a special member")__builtin_unreachable();
9317
9318 case Sema::CXXDefaultConstructor:
9319 // C++11 [class.ctor]p5:
9320 // A default constructor is trivial if:
9321 // - all the [direct subobjects] have trivial default constructors
9322 //
9323 // Note, no overload resolution is performed in this case.
9324 if (RD->hasTrivialDefaultConstructor())
9325 return true;
9326
9327 if (Selected) {
9328 // If there's a default constructor which could have been trivial, dig it
9329 // out. Otherwise, if there's any user-provided default constructor, point
9330 // to that as an example of why there's not a trivial one.
9331 CXXConstructorDecl *DefCtor = nullptr;
9332 if (RD->needsImplicitDefaultConstructor())
9333 S.DeclareImplicitDefaultConstructor(RD);
9334 for (auto *CI : RD->ctors()) {
9335 if (!CI->isDefaultConstructor())
9336 continue;
9337 DefCtor = CI;
9338 if (!DefCtor->isUserProvided())
9339 break;
9340 }
9341
9342 *Selected = DefCtor;
9343 }
9344
9345 return false;
9346
9347 case Sema::CXXDestructor:
9348 // C++11 [class.dtor]p5:
9349 // A destructor is trivial if:
9350 // - all the direct [subobjects] have trivial destructors
9351 if (RD->hasTrivialDestructor() ||
9352 (TAH == Sema::TAH_ConsiderTrivialABI &&
9353 RD->hasTrivialDestructorForCall()))
9354 return true;
9355
9356 if (Selected) {
9357 if (RD->needsImplicitDestructor())
9358 S.DeclareImplicitDestructor(RD);
9359 *Selected = RD->getDestructor();
9360 }
9361
9362 return false;
9363
9364 case Sema::CXXCopyConstructor:
9365 // C++11 [class.copy]p12:
9366 // A copy constructor is trivial if:
9367 // - the constructor selected to copy each direct [subobject] is trivial
9368 if (RD->hasTrivialCopyConstructor() ||
9369 (TAH == Sema::TAH_ConsiderTrivialABI &&
9370 RD->hasTrivialCopyConstructorForCall())) {
9371 if (Quals == Qualifiers::Const)
9372 // We must either select the trivial copy constructor or reach an
9373 // ambiguity; no need to actually perform overload resolution.
9374 return true;
9375 } else if (!Selected) {
9376 return false;
9377 }
9378 // In C++98, we are not supposed to perform overload resolution here, but we
9379 // treat that as a language defect, as suggested on cxx-abi-dev, to treat
9380 // cases like B as having a non-trivial copy constructor:
9381 // struct A { template<typename T> A(T&); };
9382 // struct B { mutable A a; };
9383 goto NeedOverloadResolution;
9384
9385 case Sema::CXXCopyAssignment:
9386 // C++11 [class.copy]p25:
9387 // A copy assignment operator is trivial if:
9388 // - the assignment operator selected to copy each direct [subobject] is
9389 // trivial
9390 if (RD->hasTrivialCopyAssignment()) {
9391 if (Quals == Qualifiers::Const)
9392 return true;
9393 } else if (!Selected) {
9394 return false;
9395 }
9396 // In C++98, we are not supposed to perform overload resolution here, but we
9397 // treat that as a language defect.
9398 goto NeedOverloadResolution;
9399
9400 case Sema::CXXMoveConstructor:
9401 case Sema::CXXMoveAssignment:
9402 NeedOverloadResolution:
9403 Sema::SpecialMemberOverloadResult SMOR =
9404 lookupCallFromSpecialMember(S, RD, CSM, Quals, ConstRHS);
9405
9406 // The standard doesn't describe how to behave if the lookup is ambiguous.
9407 // We treat it as not making the member non-trivial, just like the standard
9408 // mandates for the default constructor. This should rarely matter, because
9409 // the member will also be deleted.
9410 if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
9411 return true;
9412
9413 if (!SMOR.getMethod()) {
9414 assert(SMOR.getKind() ==((void)0)
9415 Sema::SpecialMemberOverloadResult::NoMemberOrDeleted)((void)0);
9416 return false;
9417 }
9418
9419 // We deliberately don't check if we found a deleted special member. We're
9420 // not supposed to!
9421 if (Selected)
9422 *Selected = SMOR.getMethod();
9423
9424 if (TAH == Sema::TAH_ConsiderTrivialABI &&
9425 (CSM == Sema::CXXCopyConstructor || CSM == Sema::CXXMoveConstructor))
9426 return SMOR.getMethod()->isTrivialForCall();
9427 return SMOR.getMethod()->isTrivial();
9428 }
9429
9430 llvm_unreachable("unknown special method kind")__builtin_unreachable();
9431}
9432
9433static CXXConstructorDecl *findUserDeclaredCtor(CXXRecordDecl *RD) {
9434 for (auto *CI : RD->ctors())
9435 if (!CI->isImplicit())
9436 return CI;
9437
9438 // Look for constructor templates.
9439 typedef CXXRecordDecl::specific_decl_iterator<FunctionTemplateDecl> tmpl_iter;
9440 for (tmpl_iter TI(RD->decls_begin()), TE(RD->decls_end()); TI != TE; ++TI) {
9441 if (CXXConstructorDecl *CD =
9442 dyn_cast<CXXConstructorDecl>(TI->getTemplatedDecl()))
9443 return CD;
9444 }
9445
9446 return nullptr;
9447}
9448
9449/// The kind of subobject we are checking for triviality. The values of this
9450/// enumeration are used in diagnostics.
9451enum TrivialSubobjectKind {
9452 /// The subobject is a base class.
9453 TSK_BaseClass,
9454 /// The subobject is a non-static data member.
9455 TSK_Field,
9456 /// The object is actually the complete object.
9457 TSK_CompleteObject
9458};
9459
9460/// Check whether the special member selected for a given type would be trivial.
9461static bool checkTrivialSubobjectCall(Sema &S, SourceLocation SubobjLoc,
9462 QualType SubType, bool ConstRHS,
9463 Sema::CXXSpecialMember CSM,
9464 TrivialSubobjectKind Kind,
9465 Sema::TrivialABIHandling TAH, bool Diagnose) {
9466 CXXRecordDecl *SubRD = SubType->getAsCXXRecordDecl();
9467 if (!SubRD)
9468 return true;
9469
9470 CXXMethodDecl *Selected;
9471 if (findTrivialSpecialMember(S, SubRD, CSM, SubType.getCVRQualifiers(),
9472 ConstRHS, TAH, Diagnose ? &Selected : nullptr))
9473 return true;
9474
9475 if (Diagnose) {
9476 if (ConstRHS)
9477 SubType.addConst();
9478
9479 if (!Selected && CSM == Sema::CXXDefaultConstructor) {
9480 S.Diag(SubobjLoc, diag::note_nontrivial_no_def_ctor)
9481 << Kind << SubType.getUnqualifiedType();
9482 if (CXXConstructorDecl *CD = findUserDeclaredCtor(SubRD))
9483 S.Diag(CD->getLocation(), diag::note_user_declared_ctor);
9484 } else if (!Selected)
9485 S.Diag(SubobjLoc, diag::note_nontrivial_no_copy)
9486 << Kind << SubType.getUnqualifiedType() << CSM << SubType;
9487 else if (Selected->isUserProvided()) {
9488 if (Kind == TSK_CompleteObject)
9489 S.Diag(Selected->getLocation(), diag::note_nontrivial_user_provided)
9490 << Kind << SubType.getUnqualifiedType() << CSM;
9491 else {
9492 S.Diag(SubobjLoc, diag::note_nontrivial_user_provided)
9493 << Kind << SubType.getUnqualifiedType() << CSM;
9494 S.Diag(Selected->getLocation(), diag::note_declared_at);
9495 }
9496 } else {
9497 if (Kind != TSK_CompleteObject)
9498 S.Diag(SubobjLoc, diag::note_nontrivial_subobject)
9499 << Kind << SubType.getUnqualifiedType() << CSM;
9500
9501 // Explain why the defaulted or deleted special member isn't trivial.
9502 S.SpecialMemberIsTrivial(Selected, CSM, Sema::TAH_IgnoreTrivialABI,
9503 Diagnose);
9504 }
9505 }
9506
9507 return false;
9508}
9509
9510/// Check whether the members of a class type allow a special member to be
9511/// trivial.
9512static bool checkTrivialClassMembers(Sema &S, CXXRecordDecl *RD,
9513 Sema::CXXSpecialMember CSM,
9514 bool ConstArg,
9515 Sema::TrivialABIHandling TAH,
9516 bool Diagnose) {
9517 for (const auto *FI : RD->fields()) {
9518 if (FI->isInvalidDecl() || FI->isUnnamedBitfield())
9519 continue;
9520
9521 QualType FieldType = S.Context.getBaseElementType(FI->getType());
9522
9523 // Pretend anonymous struct or union members are members of this class.
9524 if (FI->isAnonymousStructOrUnion()) {
9525 if (!checkTrivialClassMembers(S, FieldType->getAsCXXRecordDecl(),
9526 CSM, ConstArg, TAH, Diagnose))
9527 return false;
9528 continue;
9529 }
9530
9531 // C++11 [class.ctor]p5:
9532 // A default constructor is trivial if [...]
9533 // -- no non-static data member of its class has a
9534 // brace-or-equal-initializer
9535 if (CSM == Sema::CXXDefaultConstructor && FI->hasInClassInitializer()) {
9536 if (Diagnose)
9537 S.Diag(FI->getLocation(), diag::note_nontrivial_default_member_init)
9538 << FI;
9539 return false;
9540 }
9541
9542 // Objective C ARC 4.3.5:
9543 // [...] nontrivally ownership-qualified types are [...] not trivially
9544 // default constructible, copy constructible, move constructible, copy
9545 // assignable, move assignable, or destructible [...]
9546 if (FieldType.hasNonTrivialObjCLifetime()) {
9547 if (Diagnose)
9548 S.Diag(FI->getLocation(), diag::note_nontrivial_objc_ownership)
9549 << RD << FieldType.getObjCLifetime();
9550 return false;
9551 }
9552
9553 bool ConstRHS = ConstArg && !FI->isMutable();
9554 if (!checkTrivialSubobjectCall(S, FI->getLocation(), FieldType, ConstRHS,
9555 CSM, TSK_Field, TAH, Diagnose))
9556 return false;
9557 }
9558
9559 return true;
9560}
9561
9562/// Diagnose why the specified class does not have a trivial special member of
9563/// the given kind.
9564void Sema::DiagnoseNontrivial(const CXXRecordDecl *RD, CXXSpecialMember CSM) {
9565 QualType Ty = Context.getRecordType(RD);
9566
9567 bool ConstArg = (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment);
9568 checkTrivialSubobjectCall(*this, RD->getLocation(), Ty, ConstArg, CSM,
9569 TSK_CompleteObject, TAH_IgnoreTrivialABI,
9570 /*Diagnose*/true);
9571}
9572
9573/// Determine whether a defaulted or deleted special member function is trivial,
9574/// as specified in C++11 [class.ctor]p5, C++11 [class.copy]p12,
9575/// C++11 [class.copy]p25, and C++11 [class.dtor]p5.
9576bool Sema::SpecialMemberIsTrivial(CXXMethodDecl *MD, CXXSpecialMember CSM,
9577 TrivialABIHandling TAH, bool Diagnose) {
9578 assert(!MD->isUserProvided() && CSM != CXXInvalid && "not special enough")((void)0);
9579
9580 CXXRecordDecl *RD = MD->getParent();
9581
9582 bool ConstArg = false;
9583
9584 // C++11 [class.copy]p12, p25: [DR1593]
9585 // A [special member] is trivial if [...] its parameter-type-list is
9586 // equivalent to the parameter-type-list of an implicit declaration [...]
9587 switch (CSM) {
9588 case CXXDefaultConstructor:
9589 case CXXDestructor:
9590 // Trivial default constructors and destructors cannot have parameters.
9591 break;
9592
9593 case CXXCopyConstructor:
9594 case CXXCopyAssignment: {
9595 // Trivial copy operations always have const, non-volatile parameter types.
9596 ConstArg = true;
9597 const ParmVarDecl *Param0 = MD->getParamDecl(0);
9598 const ReferenceType *RT = Param0->getType()->getAs<ReferenceType>();
9599 if (!RT || RT->getPointeeType().getCVRQualifiers() != Qualifiers::Const) {
9600 if (Diagnose)
9601 Diag(Param0->getLocation(), diag::note_nontrivial_param_type)
9602 << Param0->getSourceRange() << Param0->getType()
9603 << Context.getLValueReferenceType(
9604 Context.getRecordType(RD).withConst());
9605 return false;
9606 }
9607 break;
9608 }
9609
9610 case CXXMoveConstructor:
9611 case CXXMoveAssignment: {
9612 // Trivial move operations always have non-cv-qualified parameters.
9613 const ParmVarDecl *Param0 = MD->getParamDecl(0);
9614 const RValueReferenceType *RT =
9615 Param0->getType()->getAs<RValueReferenceType>();
9616 if (!RT || RT->getPointeeType().getCVRQualifiers()) {
9617 if (Diagnose)
9618 Diag(Param0->getLocation(), diag::note_nontrivial_param_type)
9619 << Param0->getSourceRange() << Param0->getType()
9620 << Context.getRValueReferenceType(Context.getRecordType(RD));
9621 return false;
9622 }
9623 break;
9624 }
9625
9626 case CXXInvalid:
9627 llvm_unreachable("not a special member")__builtin_unreachable();
9628 }
9629
9630 if (MD->getMinRequiredArguments() < MD->getNumParams()) {
9631 if (Diagnose)
9632 Diag(MD->getParamDecl(MD->getMinRequiredArguments())->getLocation(),
9633 diag::note_nontrivial_default_arg)
9634 << MD->getParamDecl(MD->getMinRequiredArguments())->getSourceRange();
9635 return false;
9636 }
9637 if (MD->isVariadic()) {
9638 if (Diagnose)
9639 Diag(MD->getLocation(), diag::note_nontrivial_variadic);
9640 return false;
9641 }
9642
9643 // C++11 [class.ctor]p5, C++11 [class.dtor]p5:
9644 // A copy/move [constructor or assignment operator] is trivial if
9645 // -- the [member] selected to copy/move each direct base class subobject
9646 // is trivial
9647 //
9648 // C++11 [class.copy]p12, C++11 [class.copy]p25:
9649 // A [default constructor or destructor] is trivial if
9650 // -- all the direct base classes have trivial [default constructors or
9651 // destructors]
9652 for (const auto &BI : RD->bases())
9653 if (!checkTrivialSubobjectCall(*this, BI.getBeginLoc(), BI.getType(),
9654 ConstArg, CSM, TSK_BaseClass, TAH, Diagnose))
9655 return false;
9656
9657 // C++11 [class.ctor]p5, C++11 [class.dtor]p5:
9658 // A copy/move [constructor or assignment operator] for a class X is
9659 // trivial if
9660 // -- for each non-static data member of X that is of class type (or array
9661 // thereof), the constructor selected to copy/move that member is
9662 // trivial
9663 //
9664 // C++11 [class.copy]p12, C++11 [class.copy]p25:
9665 // A [default constructor or destructor] is trivial if
9666 // -- for all of the non-static data members of its class that are of class
9667 // type (or array thereof), each such class has a trivial [default
9668 // constructor or destructor]
9669 if (!checkTrivialClassMembers(*this, RD, CSM, ConstArg, TAH, Diagnose))
9670 return false;
9671
9672 // C++11 [class.dtor]p5:
9673 // A destructor is trivial if [...]
9674 // -- the destructor is not virtual
9675 if (CSM == CXXDestructor && MD->isVirtual()) {
9676 if (Diagnose)
9677 Diag(MD->getLocation(), diag::note_nontrivial_virtual_dtor) << RD;
9678 return false;
9679 }
9680
9681 // C++11 [class.ctor]p5, C++11 [class.copy]p12, C++11 [class.copy]p25:
9682 // A [special member] for class X is trivial if [...]
9683 // -- class X has no virtual functions and no virtual base classes
9684 if (CSM != CXXDestructor && MD->getParent()->isDynamicClass()) {
9685 if (!Diagnose)
9686 return false;
9687
9688 if (RD->getNumVBases()) {
9689 // Check for virtual bases. We already know that the corresponding
9690 // member in all bases is trivial, so vbases must all be direct.
9691 CXXBaseSpecifier &BS = *RD->vbases_begin();
9692 assert(BS.isVirtual())((void)0);
9693 Diag(BS.getBeginLoc(), diag::note_nontrivial_has_virtual) << RD << 1;
9694 return false;
9695 }
9696
9697 // Must have a virtual method.
9698 for (const auto *MI : RD->methods()) {
9699 if (MI->isVirtual()) {
9700 SourceLocation MLoc = MI->getBeginLoc();
9701 Diag(MLoc, diag::note_nontrivial_has_virtual) << RD << 0;
9702 return false;
9703 }
9704 }
9705
9706 llvm_unreachable("dynamic class with no vbases and no virtual functions")__builtin_unreachable();
9707 }
9708
9709 // Looks like it's trivial!
9710 return true;
9711}
9712
9713namespace {
9714struct FindHiddenVirtualMethod {
9715 Sema *S;
9716 CXXMethodDecl *Method;
9717 llvm::SmallPtrSet<const CXXMethodDecl *, 8> OverridenAndUsingBaseMethods;
9718 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
9719
9720private:
9721 /// Check whether any most overridden method from MD in Methods
9722 static bool CheckMostOverridenMethods(
9723 const CXXMethodDecl *MD,
9724 const llvm::SmallPtrSetImpl<const CXXMethodDecl *> &Methods) {
9725 if (MD->size_overridden_methods() == 0)
9726 return Methods.count(MD->getCanonicalDecl());
9727 for (const CXXMethodDecl *O : MD->overridden_methods())
9728 if (CheckMostOverridenMethods(O, Methods))
9729 return true;
9730 return false;
9731 }
9732
9733public:
9734 /// Member lookup function that determines whether a given C++
9735 /// method overloads virtual methods in a base class without overriding any,
9736 /// to be used with CXXRecordDecl::lookupInBases().
9737 bool operator()(const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
9738 RecordDecl *BaseRecord =
9739 Specifier->getType()->castAs<RecordType>()->getDecl();
9740
9741 DeclarationName Name = Method->getDeclName();
9742 assert(Name.getNameKind() == DeclarationName::Identifier)((void)0);
9743
9744 bool foundSameNameMethod = false;
9745 SmallVector<CXXMethodDecl *, 8> overloadedMethods;
9746 for (Path.Decls = BaseRecord->lookup(Name).begin();
9747 Path.Decls != DeclContext::lookup_iterator(); ++Path.Decls) {
9748 NamedDecl *D = *Path.Decls;
9749 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
9750 MD = MD->getCanonicalDecl();
9751 foundSameNameMethod = true;
9752 // Interested only in hidden virtual methods.
9753 if (!MD->isVirtual())
9754 continue;
9755 // If the method we are checking overrides a method from its base
9756 // don't warn about the other overloaded methods. Clang deviates from
9757 // GCC by only diagnosing overloads of inherited virtual functions that
9758 // do not override any other virtual functions in the base. GCC's
9759 // -Woverloaded-virtual diagnoses any derived function hiding a virtual
9760 // function from a base class. These cases may be better served by a
9761 // warning (not specific to virtual functions) on call sites when the
9762 // call would select a different function from the base class, were it
9763 // visible.
9764 // See FIXME in test/SemaCXX/warn-overload-virtual.cpp for an example.
9765 if (!S->IsOverload(Method, MD, false))
9766 return true;
9767 // Collect the overload only if its hidden.
9768 if (!CheckMostOverridenMethods(MD, OverridenAndUsingBaseMethods))
9769 overloadedMethods.push_back(MD);
9770 }
9771 }
9772
9773 if (foundSameNameMethod)
9774 OverloadedMethods.append(overloadedMethods.begin(),
9775 overloadedMethods.end());
9776 return foundSameNameMethod;
9777 }
9778};
9779} // end anonymous namespace
9780
9781/// Add the most overriden methods from MD to Methods
9782static void AddMostOverridenMethods(const CXXMethodDecl *MD,
9783 llvm::SmallPtrSetImpl<const CXXMethodDecl *>& Methods) {
9784 if (MD->size_overridden_methods() == 0)
9785 Methods.insert(MD->getCanonicalDecl());
9786 else
9787 for (const CXXMethodDecl *O : MD->overridden_methods())
9788 AddMostOverridenMethods(O, Methods);
9789}
9790
9791/// Check if a method overloads virtual methods in a base class without
9792/// overriding any.
9793void Sema::FindHiddenVirtualMethods(CXXMethodDecl *MD,
9794 SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) {
9795 if (!MD->getDeclName().isIdentifier())
9796 return;
9797
9798 CXXBasePaths Paths(/*FindAmbiguities=*/true, // true to look in all bases.
9799 /*bool RecordPaths=*/false,
9800 /*bool DetectVirtual=*/false);
9801 FindHiddenVirtualMethod FHVM;
9802 FHVM.Method = MD;
9803 FHVM.S = this;
9804
9805 // Keep the base methods that were overridden or introduced in the subclass
9806 // by 'using' in a set. A base method not in this set is hidden.
9807 CXXRecordDecl *DC = MD->getParent();
9808 DeclContext::lookup_result R = DC->lookup(MD->getDeclName());
9809 for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; ++I) {
9810 NamedDecl *ND = *I;
9811 if (UsingShadowDecl *shad = dyn_cast<UsingShadowDecl>(*I))
9812 ND = shad->getTargetDecl();
9813 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
9814 AddMostOverridenMethods(MD, FHVM.OverridenAndUsingBaseMethods);
9815 }
9816
9817 if (DC->lookupInBases(FHVM, Paths))
9818 OverloadedMethods = FHVM.OverloadedMethods;
9819}
9820
9821void Sema::NoteHiddenVirtualMethods(CXXMethodDecl *MD,
9822 SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) {
9823 for (unsigned i = 0, e = OverloadedMethods.size(); i != e; ++i) {
9824 CXXMethodDecl *overloadedMD = OverloadedMethods[i];
9825 PartialDiagnostic PD = PDiag(
9826 diag::note_hidden_overloaded_virtual_declared_here) << overloadedMD;
9827 HandleFunctionTypeMismatch(PD, MD->getType(), overloadedMD->getType());
9828 Diag(overloadedMD->getLocation(), PD);
9829 }
9830}
9831
9832/// Diagnose methods which overload virtual methods in a base class
9833/// without overriding any.
9834void Sema::DiagnoseHiddenVirtualMethods(CXXMethodDecl *MD) {
9835 if (MD->isInvalidDecl())
9836 return;
9837
9838 if (Diags.isIgnored(diag::warn_overloaded_virtual, MD->getLocation()))
9839 return;
9840
9841 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
9842 FindHiddenVirtualMethods(MD, OverloadedMethods);
9843 if (!OverloadedMethods.empty()) {
9844 Diag(MD->getLocation(), diag::warn_overloaded_virtual)
9845 << MD << (OverloadedMethods.size() > 1);
9846
9847 NoteHiddenVirtualMethods(MD, OverloadedMethods);
9848 }
9849}
9850
9851void Sema::checkIllFormedTrivialABIStruct(CXXRecordDecl &RD) {
9852 auto PrintDiagAndRemoveAttr = [&](unsigned N) {
9853 // No diagnostics if this is a template instantiation.
9854 if (!isTemplateInstantiation(RD.getTemplateSpecializationKind())) {
9855 Diag(RD.getAttr<TrivialABIAttr>()->getLocation(),
9856 diag::ext_cannot_use_trivial_abi) << &RD;
9857 Diag(RD.getAttr<TrivialABIAttr>()->getLocation(),
9858 diag::note_cannot_use_trivial_abi_reason) << &RD << N;
9859 }
9860 RD.dropAttr<TrivialABIAttr>();
9861 };
9862
9863 // Ill-formed if the copy and move constructors are deleted.
9864 auto HasNonDeletedCopyOrMoveConstructor = [&]() {
9865 // If the type is dependent, then assume it might have
9866 // implicit copy or move ctor because we won't know yet at this point.
9867 if (RD.isDependentType())
9868 return true;
9869 if (RD.needsImplicitCopyConstructor() &&
9870 !RD.defaultedCopyConstructorIsDeleted())
9871 return true;
9872 if (RD.needsImplicitMoveConstructor() &&
9873 !RD.defaultedMoveConstructorIsDeleted())
9874 return true;
9875 for (const CXXConstructorDecl *CD : RD.ctors())
9876 if (CD->isCopyOrMoveConstructor() && !CD->isDeleted())
9877 return true;
9878 return false;
9879 };
9880
9881 if (!HasNonDeletedCopyOrMoveConstructor()) {
9882 PrintDiagAndRemoveAttr(0);
9883 return;
9884 }
9885
9886 // Ill-formed if the struct has virtual functions.
9887 if (RD.isPolymorphic()) {
9888 PrintDiagAndRemoveAttr(1);
9889 return;
9890 }
9891
9892 for (const auto &B : RD.bases()) {
9893 // Ill-formed if the base class is non-trivial for the purpose of calls or a
9894 // virtual base.
9895 if (!B.getType()->isDependentType() &&
9896 !B.getType()->getAsCXXRecordDecl()->canPassInRegisters()) {
9897 PrintDiagAndRemoveAttr(2);
9898 return;
9899 }
9900
9901 if (B.isVirtual()) {
9902 PrintDiagAndRemoveAttr(3);
9903 return;
9904 }
9905 }
9906
9907 for (const auto *FD : RD.fields()) {
9908 // Ill-formed if the field is an ObjectiveC pointer or of a type that is
9909 // non-trivial for the purpose of calls.
9910 QualType FT = FD->getType();
9911 if (FT.getObjCLifetime() == Qualifiers::OCL_Weak) {
9912 PrintDiagAndRemoveAttr(4);
9913 return;
9914 }
9915
9916 if (const auto *RT = FT->getBaseElementTypeUnsafe()->getAs<RecordType>())
9917 if (!RT->isDependentType() &&
9918 !cast<CXXRecordDecl>(RT->getDecl())->canPassInRegisters()) {
9919 PrintDiagAndRemoveAttr(5);
9920 return;
9921 }
9922 }
9923}
9924
9925void Sema::ActOnFinishCXXMemberSpecification(
9926 Scope *S, SourceLocation RLoc, Decl *TagDecl, SourceLocation LBrac,
9927 SourceLocation RBrac, const ParsedAttributesView &AttrList) {
9928 if (!TagDecl)
9929 return;
9930
9931 AdjustDeclIfTemplate(TagDecl);
9932
9933 for (const ParsedAttr &AL : AttrList) {
9934 if (AL.getKind() != ParsedAttr::AT_Visibility)
9935 continue;
9936 AL.setInvalid();
9937 Diag(AL.getLoc(), diag::warn_attribute_after_definition_ignored) << AL;
9938 }
9939
9940 ActOnFields(S, RLoc, TagDecl, llvm::makeArrayRef(
9941 // strict aliasing violation!
9942 reinterpret_cast<Decl**>(FieldCollector->getCurFields()),
9943 FieldCollector->getCurNumFields()), LBrac, RBrac, AttrList);
9944
9945 CheckCompletedCXXClass(S, cast<CXXRecordDecl>(TagDecl));
9946}
9947
9948/// Find the equality comparison functions that should be implicitly declared
9949/// in a given class definition, per C++2a [class.compare.default]p3.
9950static void findImplicitlyDeclaredEqualityComparisons(
9951 ASTContext &Ctx, CXXRecordDecl *RD,
9952 llvm::SmallVectorImpl<FunctionDecl *> &Spaceships) {
9953 DeclarationName EqEq = Ctx.DeclarationNames.getCXXOperatorName(OO_EqualEqual);
9954 if (!RD->lookup(EqEq).empty())
9955 // Member operator== explicitly declared: no implicit operator==s.
9956 return;
9957
9958 // Traverse friends looking for an '==' or a '<=>'.
9959 for (FriendDecl *Friend : RD->friends()) {
9960 FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(Friend->getFriendDecl());
9961 if (!FD) continue;
9962
9963 if (FD->getOverloadedOperator() == OO_EqualEqual) {
9964 // Friend operator== explicitly declared: no implicit operator==s.
9965 Spaceships.clear();
9966 return;
9967 }
9968
9969 if (FD->getOverloadedOperator() == OO_Spaceship &&
9970 FD->isExplicitlyDefaulted())
9971 Spaceships.push_back(FD);
9972 }
9973
9974 // Look for members named 'operator<=>'.
9975 DeclarationName Cmp = Ctx.DeclarationNames.getCXXOperatorName(OO_Spaceship);
9976 for (NamedDecl *ND : RD->lookup(Cmp)) {
9977 // Note that we could find a non-function here (either a function template
9978 // or a using-declaration). Neither case results in an implicit
9979 // 'operator=='.
9980 if (auto *FD = dyn_cast<FunctionDecl>(ND))
9981 if (FD->isExplicitlyDefaulted())
9982 Spaceships.push_back(FD);
9983 }
9984}
9985
9986/// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared
9987/// special functions, such as the default constructor, copy
9988/// constructor, or destructor, to the given C++ class (C++
9989/// [special]p1). This routine can only be executed just before the
9990/// definition of the class is complete.
9991void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
9992 // Don't add implicit special members to templated classes.
9993 // FIXME: This means unqualified lookups for 'operator=' within a class
9994 // template don't work properly.
9995 if (!ClassDecl->isDependentType()) {
9996 if (ClassDecl->needsImplicitDefaultConstructor()) {
9997 ++getASTContext().NumImplicitDefaultConstructors;
9998
9999 if (ClassDecl->hasInheritedConstructor())
10000 DeclareImplicitDefaultConstructor(ClassDecl);
10001 }
10002
10003 if (ClassDecl->needsImplicitCopyConstructor()) {
10004 ++getASTContext().NumImplicitCopyConstructors;
10005
10006 // If the properties or semantics of the copy constructor couldn't be
10007 // determined while the class was being declared, force a declaration
10008 // of it now.
10009 if (ClassDecl->needsOverloadResolutionForCopyConstructor() ||
10010 ClassDecl->hasInheritedConstructor())
10011 DeclareImplicitCopyConstructor(ClassDecl);
10012 // For the MS ABI we need to know whether the copy ctor is deleted. A
10013 // prerequisite for deleting the implicit copy ctor is that the class has
10014 // a move ctor or move assignment that is either user-declared or whose
10015 // semantics are inherited from a subobject. FIXME: We should provide a
10016 // more direct way for CodeGen to ask whether the constructor was deleted.
10017 else if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
10018 (ClassDecl->hasUserDeclaredMoveConstructor() ||
10019 ClassDecl->needsOverloadResolutionForMoveConstructor() ||
10020 ClassDecl->hasUserDeclaredMoveAssignment() ||
10021 ClassDecl->needsOverloadResolutionForMoveAssignment()))
10022 DeclareImplicitCopyConstructor(ClassDecl);
10023 }
10024
10025 if (getLangOpts().CPlusPlus11 &&
10026 ClassDecl->needsImplicitMoveConstructor()) {
10027 ++getASTContext().NumImplicitMoveConstructors;
10028
10029 if (ClassDecl->needsOverloadResolutionForMoveConstructor() ||
10030 ClassDecl->hasInheritedConstructor())
10031 DeclareImplicitMoveConstructor(ClassDecl);
10032 }
10033
10034 if (ClassDecl->needsImplicitCopyAssignment()) {
10035 ++getASTContext().NumImplicitCopyAssignmentOperators;
10036
10037 // If we have a dynamic class, then the copy assignment operator may be
10038 // virtual, so we have to declare it immediately. This ensures that, e.g.,
10039 // it shows up in the right place in the vtable and that we diagnose
10040 // problems with the implicit exception specification.
10041 if (ClassDecl->isDynamicClass() ||
10042 ClassDecl->needsOverloadResolutionForCopyAssignment() ||
10043 ClassDecl->hasInheritedAssignment())
10044 DeclareImplicitCopyAssignment(ClassDecl);
10045 }
10046
10047 if (getLangOpts().CPlusPlus11 && ClassDecl->needsImplicitMoveAssignment()) {
10048 ++getASTContext().NumImplicitMoveAssignmentOperators;
10049
10050 // Likewise for the move assignment operator.
10051 if (ClassDecl->isDynamicClass() ||
10052 ClassDecl->needsOverloadResolutionForMoveAssignment() ||
10053 ClassDecl->hasInheritedAssignment())
10054 DeclareImplicitMoveAssignment(ClassDecl);
10055 }
10056
10057 if (ClassDecl->needsImplicitDestructor()) {
10058 ++getASTContext().NumImplicitDestructors;
10059
10060 // If we have a dynamic class, then the destructor may be virtual, so we
10061 // have to declare the destructor immediately. This ensures that, e.g., it
10062 // shows up in the right place in the vtable and that we diagnose problems
10063 // with the implicit exception specification.
10064 if (ClassDecl->isDynamicClass() ||
10065 ClassDecl->needsOverloadResolutionForDestructor())
10066 DeclareImplicitDestructor(ClassDecl);
10067 }
10068 }
10069
10070 // C++2a [class.compare.default]p3:
10071 // If the member-specification does not explicitly declare any member or
10072 // friend named operator==, an == operator function is declared implicitly
10073 // for each defaulted three-way comparison operator function defined in
10074 // the member-specification
10075 // FIXME: Consider doing this lazily.
10076 // We do this during the initial parse for a class template, not during
10077 // instantiation, so that we can handle unqualified lookups for 'operator=='
10078 // when parsing the template.
10079 if (getLangOpts().CPlusPlus20 && !inTemplateInstantiation()) {
10080 llvm::SmallVector<FunctionDecl *, 4> DefaultedSpaceships;
10081 findImplicitlyDeclaredEqualityComparisons(Context, ClassDecl,
10082 DefaultedSpaceships);
10083 for (auto *FD : DefaultedSpaceships)
10084 DeclareImplicitEqualityComparison(ClassDecl, FD);
10085 }
10086}
10087
10088unsigned
10089Sema::ActOnReenterTemplateScope(Decl *D,
10090 llvm::function_ref<Scope *()> EnterScope) {
10091 if (!D)
10092 return 0;
10093 AdjustDeclIfTemplate(D);
10094
10095 // In order to get name lookup right, reenter template scopes in order from
10096 // outermost to innermost.
10097 SmallVector<TemplateParameterList *, 4> ParameterLists;
10098 DeclContext *LookupDC = dyn_cast<DeclContext>(D);
10099
10100 if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
10101 for (unsigned i = 0; i < DD->getNumTemplateParameterLists(); ++i)
10102 ParameterLists.push_back(DD->getTemplateParameterList(i));
10103
10104 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
10105 if (FunctionTemplateDecl *FTD = FD->getDescribedFunctionTemplate())
10106 ParameterLists.push_back(FTD->getTemplateParameters());
10107 } else if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
10108 LookupDC = VD->getDeclContext();
10109
10110 if (VarTemplateDecl *VTD = VD->getDescribedVarTemplate())
10111 ParameterLists.push_back(VTD->getTemplateParameters());
10112 else if (auto *PSD = dyn_cast<VarTemplatePartialSpecializationDecl>(D))
10113 ParameterLists.push_back(PSD->getTemplateParameters());
10114 }
10115 } else if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
10116 for (unsigned i = 0; i < TD->getNumTemplateParameterLists(); ++i)
10117 ParameterLists.push_back(TD->getTemplateParameterList(i));
10118
10119 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) {
10120 if (ClassTemplateDecl *CTD = RD->getDescribedClassTemplate())
10121 ParameterLists.push_back(CTD->getTemplateParameters());
10122 else if (auto *PSD = dyn_cast<ClassTemplatePartialSpecializationDecl>(D))
10123 ParameterLists.push_back(PSD->getTemplateParameters());
10124 }
10125 }
10126 // FIXME: Alias declarations and concepts.
10127
10128 unsigned Count = 0;
10129 Scope *InnermostTemplateScope = nullptr;
10130 for (TemplateParameterList *Params : ParameterLists) {
10131 // Ignore explicit specializations; they don't contribute to the template
10132 // depth.
10133 if (Params->size() == 0)
10134 continue;
10135
10136 InnermostTemplateScope = EnterScope();
10137 for (NamedDecl *Param : *Params) {
10138 if (Param->getDeclName()) {
10139 InnermostTemplateScope->AddDecl(Param);
10140 IdResolver.AddDecl(Param);
10141 }
10142 }
10143 ++Count;
10144 }
10145
10146 // Associate the new template scopes with the corresponding entities.
10147 if (InnermostTemplateScope) {
10148 assert(LookupDC && "no enclosing DeclContext for template lookup")((void)0);
10149 EnterTemplatedContext(InnermostTemplateScope, LookupDC);
10150 }
10151
10152 return Count;
10153}
10154
10155void Sema::ActOnStartDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
10156 if (!RecordD) return;
10157 AdjustDeclIfTemplate(RecordD);
10158 CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordD);
10159 PushDeclContext(S, Record);
10160}
10161
10162void Sema::ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
10163 if (!RecordD) return;
10164 PopDeclContext();
10165}
10166
10167/// This is used to implement the constant expression evaluation part of the
10168/// attribute enable_if extension. There is nothing in standard C++ which would
10169/// require reentering parameters.
10170void Sema::ActOnReenterCXXMethodParameter(Scope *S, ParmVarDecl *Param) {
10171 if (!Param)
10172 return;
10173
10174 S->AddDecl(Param);
10175 if (Param->getDeclName())
10176 IdResolver.AddDecl(Param);
10177}
10178
10179/// ActOnStartDelayedCXXMethodDeclaration - We have completed
10180/// parsing a top-level (non-nested) C++ class, and we are now
10181/// parsing those parts of the given Method declaration that could
10182/// not be parsed earlier (C++ [class.mem]p2), such as default
10183/// arguments. This action should enter the scope of the given
10184/// Method declaration as if we had just parsed the qualified method
10185/// name. However, it should not bring the parameters into scope;
10186/// that will be performed by ActOnDelayedCXXMethodParameter.
10187void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
10188}
10189
10190/// ActOnDelayedCXXMethodParameter - We've already started a delayed
10191/// C++ method declaration. We're (re-)introducing the given
10192/// function parameter into scope for use in parsing later parts of
10193/// the method declaration. For example, we could see an
10194/// ActOnParamDefaultArgument event for this parameter.
10195void Sema::ActOnDelayedCXXMethodParameter(Scope *S, Decl *ParamD) {
10196 if (!ParamD)
10197 return;
10198
10199 ParmVarDecl *Param = cast<ParmVarDecl>(ParamD);
10200
10201 S->AddDecl(Param);
10202 if (Param->getDeclName())
10203 IdResolver.AddDecl(Param);
10204}
10205
10206/// ActOnFinishDelayedCXXMethodDeclaration - We have finished
10207/// processing the delayed method declaration for Method. The method
10208/// declaration is now considered finished. There may be a separate
10209/// ActOnStartOfFunctionDef action later (not necessarily
10210/// immediately!) for this method, if it was also defined inside the
10211/// class body.
10212void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
10213 if (!MethodD)
10214 return;
10215
10216 AdjustDeclIfTemplate(MethodD);
10217
10218 FunctionDecl *Method = cast<FunctionDecl>(MethodD);
10219
10220 // Now that we have our default arguments, check the constructor
10221 // again. It could produce additional diagnostics or affect whether
10222 // the class has implicitly-declared destructors, among other
10223 // things.
10224 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method))
10225 CheckConstructor(Constructor);
10226
10227 // Check the default arguments, which we may have added.
10228 if (!Method->isInvalidDecl())
10229 CheckCXXDefaultArguments(Method);
10230}
10231
10232// Emit the given diagnostic for each non-address-space qualifier.
10233// Common part of CheckConstructorDeclarator and CheckDestructorDeclarator.
10234static void checkMethodTypeQualifiers(Sema &S, Declarator &D, unsigned DiagID) {
10235 const DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
10236 if (FTI.hasMethodTypeQualifiers() && !D.isInvalidType()) {
10237 bool DiagOccured = false;
10238 FTI.MethodQualifiers->forEachQualifier(
10239 [DiagID, &S, &DiagOccured](DeclSpec::TQ, StringRef QualName,
10240 SourceLocation SL) {
10241 // This diagnostic should be emitted on any qualifier except an addr
10242 // space qualifier. However, forEachQualifier currently doesn't visit
10243 // addr space qualifiers, so there's no way to write this condition
10244 // right now; we just diagnose on everything.
10245 S.Diag(SL, DiagID) << QualName << SourceRange(SL);
10246 DiagOccured = true;
10247 });
10248 if (DiagOccured)
10249 D.setInvalidType();
10250 }
10251}
10252
10253/// CheckConstructorDeclarator - Called by ActOnDeclarator to check
10254/// the well-formedness of the constructor declarator @p D with type @p
10255/// R. If there are any errors in the declarator, this routine will
10256/// emit diagnostics and set the invalid bit to true. In any case, the type
10257/// will be updated to reflect a well-formed type for the constructor and
10258/// returned.
10259QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R,
10260 StorageClass &SC) {
10261 bool isVirtual = D.getDeclSpec().isVirtualSpecified();
10262
10263 // C++ [class.ctor]p3:
10264 // A constructor shall not be virtual (10.3) or static (9.4). A
10265 // constructor can be invoked for a const, volatile or const
10266 // volatile object. A constructor shall not be declared const,
10267 // volatile, or const volatile (9.3.2).
10268 if (isVirtual) {
10269 if (!D.isInvalidType())
10270 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
10271 << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc())
10272 << SourceRange(D.getIdentifierLoc());
10273 D.setInvalidType();
10274 }
10275 if (SC == SC_Static) {
10276 if (!D.isInvalidType())
10277 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
10278 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
10279 << SourceRange(D.getIdentifierLoc());
10280 D.setInvalidType();
10281 SC = SC_None;
10282 }
10283
10284 if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) {
10285 diagnoseIgnoredQualifiers(
10286 diag::err_constructor_return_type, TypeQuals, SourceLocation(),
10287 D.getDeclSpec().getConstSpecLoc(), D.getDeclSpec().getVolatileSpecLoc(),
10288 D.getDeclSpec().getRestrictSpecLoc(),
10289 D.getDeclSpec().getAtomicSpecLoc());
10290 D.setInvalidType();
10291 }
10292
10293 checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_constructor);
10294
10295 // C++0x [class.ctor]p4:
10296 // A constructor shall not be declared with a ref-qualifier.
10297 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
10298 if (FTI.hasRefQualifier()) {
10299 Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_constructor)
10300 << FTI.RefQualifierIsLValueRef
10301 << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
10302 D.setInvalidType();
10303 }
10304
10305 // Rebuild the function type "R" without any type qualifiers (in
10306 // case any of the errors above fired) and with "void" as the
10307 // return type, since constructors don't have return types.
10308 const FunctionProtoType *Proto = R->castAs<FunctionProtoType>();
10309 if (Proto->getReturnType() == Context.VoidTy && !D.isInvalidType())
10310 return R;
10311
10312 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
10313 EPI.TypeQuals = Qualifiers();
10314 EPI.RefQualifier = RQ_None;
10315
10316 return Context.getFunctionType(Context.VoidTy, Proto->getParamTypes(), EPI);
10317}
10318
10319/// CheckConstructor - Checks a fully-formed constructor for
10320/// well-formedness, issuing any diagnostics required. Returns true if
10321/// the constructor declarator is invalid.
10322void Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
10323 CXXRecordDecl *ClassDecl
10324 = dyn_cast<CXXRecordDecl>(Constructor->getDeclContext());
10325 if (!ClassDecl)
10326 return Constructor->setInvalidDecl();
10327
10328 // C++ [class.copy]p3:
10329 // A declaration of a constructor for a class X is ill-formed if
10330 // its first parameter is of type (optionally cv-qualified) X and
10331 // either there are no other parameters or else all other
10332 // parameters have default arguments.
10333 if (!Constructor->isInvalidDecl() &&
10334 Constructor->hasOneParamOrDefaultArgs() &&
10335 Constructor->getTemplateSpecializationKind() !=
10336 TSK_ImplicitInstantiation) {
10337 QualType ParamType = Constructor->getParamDecl(0)->getType();
10338 QualType ClassTy = Context.getTagDeclType(ClassDecl);
10339 if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) {
10340 SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation();
10341 const char *ConstRef
10342 = Constructor->getParamDecl(0)->getIdentifier() ? "const &"
10343 : " const &";
10344 Diag(ParamLoc, diag::err_constructor_byvalue_arg)
10345 << FixItHint::CreateInsertion(ParamLoc, ConstRef);
10346
10347 // FIXME: Rather that making the constructor invalid, we should endeavor
10348 // to fix the type.
10349 Constructor->setInvalidDecl();
10350 }
10351 }
10352}
10353
10354/// CheckDestructor - Checks a fully-formed destructor definition for
10355/// well-formedness, issuing any diagnostics required. Returns true
10356/// on error.
10357bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
10358 CXXRecordDecl *RD = Destructor->getParent();
10359
10360 if (!Destructor->getOperatorDelete() && Destructor->isVirtual()) {
10361 SourceLocation Loc;
10362
10363 if (!Destructor->isImplicit())
10364 Loc = Destructor->getLocation();
10365 else
10366 Loc = RD->getLocation();
10367
10368 // If we have a virtual destructor, look up the deallocation function
10369 if (FunctionDecl *OperatorDelete =
10370 FindDeallocationFunctionForDestructor(Loc, RD)) {
10371 Expr *ThisArg = nullptr;
10372
10373 // If the notional 'delete this' expression requires a non-trivial
10374 // conversion from 'this' to the type of a destroying operator delete's
10375 // first parameter, perform that conversion now.
10376 if (OperatorDelete->isDestroyingOperatorDelete()) {
10377 QualType ParamType = OperatorDelete->getParamDecl(0)->getType();
10378 if (!declaresSameEntity(ParamType->getAsCXXRecordDecl(), RD)) {
10379 // C++ [class.dtor]p13:
10380 // ... as if for the expression 'delete this' appearing in a
10381 // non-virtual destructor of the destructor's class.
10382 ContextRAII SwitchContext(*this, Destructor);
10383 ExprResult This =
10384 ActOnCXXThis(OperatorDelete->getParamDecl(0)->getLocation());
10385 assert(!This.isInvalid() && "couldn't form 'this' expr in dtor?")((void)0);
10386 This = PerformImplicitConversion(This.get(), ParamType, AA_Passing);
10387 if (This.isInvalid()) {
10388 // FIXME: Register this as a context note so that it comes out
10389 // in the right order.
10390 Diag(Loc, diag::note_implicit_delete_this_in_destructor_here);
10391 return true;
10392 }
10393 ThisArg = This.get();
10394 }
10395 }
10396
10397 DiagnoseUseOfDecl(OperatorDelete, Loc);
10398 MarkFunctionReferenced(Loc, OperatorDelete);
10399 Destructor->setOperatorDelete(OperatorDelete, ThisArg);
10400 }
10401 }
10402
10403 return false;
10404}
10405
10406/// CheckDestructorDeclarator - Called by ActOnDeclarator to check
10407/// the well-formednes of the destructor declarator @p D with type @p
10408/// R. If there are any errors in the declarator, this routine will
10409/// emit diagnostics and set the declarator to invalid. Even if this happens,
10410/// will be updated to reflect a well-formed type for the destructor and
10411/// returned.
10412QualType Sema::CheckDestructorDeclarator(Declarator &D, QualType R,
10413 StorageClass& SC) {
10414 // C++ [class.dtor]p1:
10415 // [...] A typedef-name that names a class is a class-name
10416 // (7.1.3); however, a typedef-name that names a class shall not
10417 // be used as the identifier in the declarator for a destructor
10418 // declaration.
10419 QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName);
10420 if (const TypedefType *TT = DeclaratorType->getAs<TypedefType>())
10421 Diag(D.getIdentifierLoc(), diag::ext_destructor_typedef_name)
10422 << DeclaratorType << isa<TypeAliasDecl>(TT->getDecl());
10423 else if (const TemplateSpecializationType *TST =
10424 DeclaratorType->getAs<TemplateSpecializationType>())
10425 if (TST->isTypeAlias())
10426 Diag(D.getIdentifierLoc(), diag::ext_destructor_typedef_name)
10427 << DeclaratorType << 1;
10428
10429 // C++ [class.dtor]p2:
10430 // A destructor is used to destroy objects of its class type. A
10431 // destructor takes no parameters, and no return type can be
10432 // specified for it (not even void). The address of a destructor
10433 // shall not be taken. A destructor shall not be static. A
10434 // destructor can be invoked for a const, volatile or const
10435 // volatile object. A destructor shall not be declared const,
10436 // volatile or const volatile (9.3.2).
10437 if (SC == SC_Static) {
10438 if (!D.isInvalidType())
10439 Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be)
10440 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
10441 << SourceRange(D.getIdentifierLoc())
10442 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
10443
10444 SC = SC_None;
10445 }
10446 if (!D.isInvalidType()) {
10447 // Destructors don't have return types, but the parser will
10448 // happily parse something like:
10449 //
10450 // class X {
10451 // float ~X();
10452 // };
10453 //
10454 // The return type will be eliminated later.
10455 if (D.getDeclSpec().hasTypeSpecifier())
10456 Diag(D.getIdentifierLoc(), diag::err_destructor_return_type)
10457 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
10458 << SourceRange(D.getIdentifierLoc());
10459 else if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) {
10460 diagnoseIgnoredQualifiers(diag::err_destructor_return_type, TypeQuals,
10461 SourceLocation(),
10462 D.getDeclSpec().getConstSpecLoc(),
10463 D.getDeclSpec().getVolatileSpecLoc(),
10464 D.getDeclSpec().getRestrictSpecLoc(),
10465 D.getDeclSpec().getAtomicSpecLoc());
10466 D.setInvalidType();
10467 }
10468 }
10469
10470 checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_destructor);
10471
10472 // C++0x [class.dtor]p2:
10473 // A destructor shall not be declared with a ref-qualifier.
10474 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
10475 if (FTI.hasRefQualifier()) {
10476 Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_destructor)
10477 << FTI.RefQualifierIsLValueRef
10478 << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
10479 D.setInvalidType();
10480 }
10481
10482 // Make sure we don't have any parameters.
10483 if (FTIHasNonVoidParameters(FTI)) {
10484 Diag(D.getIdentifierLoc(), diag::err_destructor_with_params);
10485
10486 // Delete the parameters.
10487 FTI.freeParams();
10488 D.setInvalidType();
10489 }
10490
10491 // Make sure the destructor isn't variadic.
10492 if (FTI.isVariadic) {
10493 Diag(D.getIdentifierLoc(), diag::err_destructor_variadic);
10494 D.setInvalidType();
10495 }
10496
10497 // Rebuild the function type "R" without any type qualifiers or
10498 // parameters (in case any of the errors above fired) and with
10499 // "void" as the return type, since destructors don't have return
10500 // types.
10501 if (!D.isInvalidType())
10502 return R;
10503
10504 const FunctionProtoType *Proto = R->castAs<FunctionProtoType>();
10505 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
10506 EPI.Variadic = false;
10507 EPI.TypeQuals = Qualifiers();
10508 EPI.RefQualifier = RQ_None;
10509 return Context.getFunctionType(Context.VoidTy, None, EPI);
10510}
10511
10512static void extendLeft(SourceRange &R, SourceRange Before) {
10513 if (Before.isInvalid())
10514 return;
10515 R.setBegin(Before.getBegin());
10516 if (R.getEnd().isInvalid())
10517 R.setEnd(Before.getEnd());
10518}
10519
10520static void extendRight(SourceRange &R, SourceRange After) {
10521 if (After.isInvalid())
10522 return;
10523 if (R.getBegin().isInvalid())
10524 R.setBegin(After.getBegin());
10525 R.setEnd(After.getEnd());
10526}
10527
10528/// CheckConversionDeclarator - Called by ActOnDeclarator to check the
10529/// well-formednes of the conversion function declarator @p D with
10530/// type @p R. If there are any errors in the declarator, this routine
10531/// will emit diagnostics and return true. Otherwise, it will return
10532/// false. Either way, the type @p R will be updated to reflect a
10533/// well-formed type for the conversion operator.
10534void Sema::CheckConversionDeclarator(Declarator &D, QualType &R,
10535 StorageClass& SC) {
10536 // C++ [class.conv.fct]p1:
10537 // Neither parameter types nor return type can be specified. The
10538 // type of a conversion function (8.3.5) is "function taking no
10539 // parameter returning conversion-type-id."
10540 if (SC == SC_Static) {
10541 if (!D.isInvalidType())
10542 Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member)
10543 << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
10544 << D.getName().getSourceRange();
10545 D.setInvalidType();
10546 SC = SC_None;
10547 }
10548
10549 TypeSourceInfo *ConvTSI = nullptr;
10550 QualType ConvType =
10551 GetTypeFromParser(D.getName().ConversionFunctionId, &ConvTSI);
10552
10553 const DeclSpec &DS = D.getDeclSpec();
10554 if (DS.hasTypeSpecifier() && !D.isInvalidType()) {
10555 // Conversion functions don't have return types, but the parser will
10556 // happily parse something like:
10557 //
10558 // class X {
10559 // float operator bool();
10560 // };
10561 //
10562 // The return type will be changed later anyway.
10563 Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type)
10564 << SourceRange(DS.getTypeSpecTypeLoc())
10565 << SourceRange(D.getIdentifierLoc());
10566 D.setInvalidType();
10567 } else if (DS.getTypeQualifiers() && !D.isInvalidType()) {
10568 // It's also plausible that the user writes type qualifiers in the wrong
10569 // place, such as:
10570 // struct S { const operator int(); };
10571 // FIXME: we could provide a fixit to move the qualifiers onto the
10572 // conversion type.
10573 Diag(D.getIdentifierLoc(), diag::err_conv_function_with_complex_decl)
10574 << SourceRange(D.getIdentifierLoc()) << 0;
10575 D.setInvalidType();
10576 }
10577
10578 const auto *Proto = R->castAs<FunctionProtoType>();
10579
10580 // Make sure we don't have any parameters.
10581 if (Proto->getNumParams() > 0) {
10582 Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params);
10583
10584 // Delete the parameters.
10585 D.getFunctionTypeInfo().freeParams();
10586 D.setInvalidType();
10587 } else if (Proto->isVariadic()) {
10588 Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic);
10589 D.setInvalidType();
10590 }
10591
10592 // Diagnose "&operator bool()" and other such nonsense. This
10593 // is actually a gcc extension which we don't support.
10594 if (Proto->getReturnType() != ConvType) {
10595 bool NeedsTypedef = false;
10596 SourceRange Before, After;
10597
10598 // Walk the chunks and extract information on them for our diagnostic.
10599 bool PastFunctionChunk = false;
10600 for (auto &Chunk : D.type_objects()) {
10601 switch (Chunk.Kind) {
10602 case DeclaratorChunk::Function:
10603 if (!PastFunctionChunk) {
10604 if (Chunk.Fun.HasTrailingReturnType) {
10605 TypeSourceInfo *TRT = nullptr;
10606 GetTypeFromParser(Chunk.Fun.getTrailingReturnType(), &TRT);
10607 if (TRT) extendRight(After, TRT->getTypeLoc().getSourceRange());
10608 }
10609 PastFunctionChunk = true;
10610 break;
10611 }
10612 LLVM_FALLTHROUGH[[gnu::fallthrough]];
10613 case DeclaratorChunk::Array:
10614 NeedsTypedef = true;
10615 extendRight(After, Chunk.getSourceRange());
10616 break;
10617
10618 case DeclaratorChunk::Pointer:
10619 case DeclaratorChunk::BlockPointer:
10620 case DeclaratorChunk::Reference:
10621 case DeclaratorChunk::MemberPointer:
10622 case DeclaratorChunk::Pipe:
10623 extendLeft(Before, Chunk.getSourceRange());
10624 break;
10625
10626 case DeclaratorChunk::Paren:
10627 extendLeft(Before, Chunk.Loc);
10628 extendRight(After, Chunk.EndLoc);
10629 break;
10630 }
10631 }
10632
10633 SourceLocation Loc = Before.isValid() ? Before.getBegin() :
10634 After.isValid() ? After.getBegin() :
10635 D.getIdentifierLoc();
10636 auto &&DB = Diag(Loc, diag::err_conv_function_with_complex_decl);
10637 DB << Before << After;
10638
10639 if (!NeedsTypedef) {
10640 DB << /*don't need a typedef*/0;
10641
10642 // If we can provide a correct fix-it hint, do so.
10643 if (After.isInvalid() && ConvTSI) {
10644 SourceLocation InsertLoc =
10645 getLocForEndOfToken(ConvTSI->getTypeLoc().getEndLoc());
10646 DB << FixItHint::CreateInsertion(InsertLoc, " ")
10647 << FixItHint::CreateInsertionFromRange(
10648 InsertLoc, CharSourceRange::getTokenRange(Before))
10649 << FixItHint::CreateRemoval(Before);
10650 }
10651 } else if (!Proto->getReturnType()->isDependentType()) {
10652 DB << /*typedef*/1 << Proto->getReturnType();
10653 } else if (getLangOpts().CPlusPlus11) {
10654 DB << /*alias template*/2 << Proto->getReturnType();
10655 } else {
10656 DB << /*might not be fixable*/3;
10657 }
10658
10659 // Recover by incorporating the other type chunks into the result type.
10660 // Note, this does *not* change the name of the function. This is compatible
10661 // with the GCC extension:
10662 // struct S { &operator int(); } s;
10663 // int &r = s.operator int(); // ok in GCC
10664 // S::operator int&() {} // error in GCC, function name is 'operator int'.
10665 ConvType = Proto->getReturnType();
10666 }
10667
10668 // C++ [class.conv.fct]p4:
10669 // The conversion-type-id shall not represent a function type nor
10670 // an array type.
10671 if (ConvType->isArrayType()) {
10672 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array);
10673 ConvType = Context.getPointerType(ConvType);
10674 D.setInvalidType();
10675 } else if (ConvType->isFunctionType()) {
10676 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function);
10677 ConvType = Context.getPointerType(ConvType);
10678 D.setInvalidType();
10679 }
10680
10681 // Rebuild the function type "R" without any parameters (in case any
10682 // of the errors above fired) and with the conversion type as the
10683 // return type.
10684 if (D.isInvalidType())
10685 R = Context.getFunctionType(ConvType, None, Proto->getExtProtoInfo());
10686
10687 // C++0x explicit conversion operators.
10688 if (DS.hasExplicitSpecifier() && !getLangOpts().CPlusPlus20)
10689 Diag(DS.getExplicitSpecLoc(),
10690 getLangOpts().CPlusPlus11
10691 ? diag::warn_cxx98_compat_explicit_conversion_functions
10692 : diag::ext_explicit_conversion_functions)
10693 << SourceRange(DS.getExplicitSpecRange());
10694}
10695
10696/// ActOnConversionDeclarator - Called by ActOnDeclarator to complete
10697/// the declaration of the given C++ conversion function. This routine
10698/// is responsible for recording the conversion function in the C++
10699/// class, if possible.
10700Decl *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
10701 assert(Conversion && "Expected to receive a conversion function declaration")((void)0);
10702
10703 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext());
10704
10705 // Make sure we aren't redeclaring the conversion function.
10706 QualType ConvType = Context.getCanonicalType(Conversion->getConversionType());
10707 // C++ [class.conv.fct]p1:
10708 // [...] A conversion function is never used to convert a
10709 // (possibly cv-qualified) object to the (possibly cv-qualified)
10710 // same object type (or a reference to it), to a (possibly
10711 // cv-qualified) base class of that type (or a reference to it),
10712 // or to (possibly cv-qualified) void.
10713 QualType ClassType
10714 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
10715 if (const ReferenceType *ConvTypeRef = ConvType->getAs<ReferenceType>())
10716 ConvType = ConvTypeRef->getPointeeType();
10717 if (Conversion->getTemplateSpecializationKind() != TSK_Undeclared &&
10718 Conversion->getTemplateSpecializationKind() != TSK_ExplicitSpecialization)
10719 /* Suppress diagnostics for instantiations. */;
10720 else if (Conversion->size_overridden_methods() != 0)
10721 /* Suppress diagnostics for overriding virtual function in a base class. */;
10722 else if (ConvType->isRecordType()) {
10723 ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType();
10724 if (ConvType == ClassType)
10725 Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
10726 << ClassType;
10727 else if (IsDerivedFrom(Conversion->getLocation(), ClassType, ConvType))
10728 Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
10729 << ClassType << ConvType;
10730 } else if (ConvType->isVoidType()) {
10731 Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used)
10732 << ClassType << ConvType;
10733 }
10734
10735 if (FunctionTemplateDecl *ConversionTemplate
10736 = Conversion->getDescribedFunctionTemplate())
10737 return ConversionTemplate;
10738
10739 return Conversion;
10740}
10741
10742namespace {
10743/// Utility class to accumulate and print a diagnostic listing the invalid
10744/// specifier(s) on a declaration.
10745struct BadSpecifierDiagnoser {
10746 BadSpecifierDiagnoser(Sema &S, SourceLocation Loc, unsigned DiagID)
10747 : S(S), Diagnostic(S.Diag(Loc, DiagID)) {}
10748 ~BadSpecifierDiagnoser() {
10749 Diagnostic << Specifiers;
10750 }
10751
10752 template<typename T> void check(SourceLocation SpecLoc, T Spec) {
10753 return check(SpecLoc, DeclSpec::getSpecifierName(Spec));
10754 }
10755 void check(SourceLocation SpecLoc, DeclSpec::TST Spec) {
10756 return check(SpecLoc,
10757 DeclSpec::getSpecifierName(Spec, S.getPrintingPolicy()));
10758 }
10759 void check(SourceLocation SpecLoc, const char *Spec) {
10760 if (SpecLoc.isInvalid()) return;
10761 Diagnostic << SourceRange(SpecLoc, SpecLoc);
10762 if (!Specifiers.empty()) Specifiers += " ";
10763 Specifiers += Spec;
10764 }
10765
10766 Sema &S;
10767 Sema::SemaDiagnosticBuilder Diagnostic;
10768 std::string Specifiers;
10769};
10770}
10771
10772/// Check the validity of a declarator that we parsed for a deduction-guide.
10773/// These aren't actually declarators in the grammar, so we need to check that
10774/// the user didn't specify any pieces that are not part of the deduction-guide
10775/// grammar.
10776void Sema::CheckDeductionGuideDeclarator(Declarator &D, QualType &R,
10777 StorageClass &SC) {
10778 TemplateName GuidedTemplate = D.getName().TemplateName.get().get();
10779 TemplateDecl *GuidedTemplateDecl = GuidedTemplate.getAsTemplateDecl();
10780 assert(GuidedTemplateDecl && "missing template decl for deduction guide")((void)0);
10781
10782 // C++ [temp.deduct.guide]p3:
10783 // A deduction-gide shall be declared in the same scope as the
10784 // corresponding class template.
10785 if (!CurContext->getRedeclContext()->Equals(
10786 GuidedTemplateDecl->getDeclContext()->getRedeclContext())) {
10787 Diag(D.getIdentifierLoc(), diag::err_deduction_guide_wrong_scope)
10788 << GuidedTemplateDecl;
10789 Diag(GuidedTemplateDecl->getLocation(), diag::note_template_decl_here);
10790 }
10791
10792 auto &DS = D.getMutableDeclSpec();
10793 // We leave 'friend' and 'virtual' to be rejected in the normal way.
10794 if (DS.hasTypeSpecifier() || DS.getTypeQualifiers() ||
10795 DS.getStorageClassSpecLoc().isValid() || DS.isInlineSpecified() ||
10796 DS.isNoreturnSpecified() || DS.hasConstexprSpecifier()) {
10797 BadSpecifierDiagnoser Diagnoser(
10798 *this, D.getIdentifierLoc(),
10799 diag::err_deduction_guide_invalid_specifier);
10800
10801 Diagnoser.check(DS.getStorageClassSpecLoc(), DS.getStorageClassSpec());
10802 DS.ClearStorageClassSpecs();
10803 SC = SC_None;
10804
10805 // 'explicit' is permitted.
10806 Diagnoser.check(DS.getInlineSpecLoc(), "inline");
10807 Diagnoser.check(DS.getNoreturnSpecLoc(), "_Noreturn");
10808 Diagnoser.check(DS.getConstexprSpecLoc(), "constexpr");
10809 DS.ClearConstexprSpec();
10810
10811 Diagnoser.check(DS.getConstSpecLoc(), "const");
10812 Diagnoser.check(DS.getRestrictSpecLoc(), "__restrict");
10813 Diagnoser.check(DS.getVolatileSpecLoc(), "volatile");
10814 Diagnoser.check(DS.getAtomicSpecLoc(), "_Atomic");
10815 Diagnoser.check(DS.getUnalignedSpecLoc(), "__unaligned");
10816 DS.ClearTypeQualifiers();
10817
10818 Diagnoser.check(DS.getTypeSpecComplexLoc(), DS.getTypeSpecComplex());
10819 Diagnoser.check(DS.getTypeSpecSignLoc(), DS.getTypeSpecSign());
10820 Diagnoser.check(DS.getTypeSpecWidthLoc(), DS.getTypeSpecWidth());
10821 Diagnoser.check(DS.getTypeSpecTypeLoc(), DS.getTypeSpecType());
10822 DS.ClearTypeSpecType();
10823 }
10824
10825 if (D.isInvalidType())
10826 return;
10827
10828 // Check the declarator is simple enough.
10829 bool FoundFunction = false;
10830 for (const DeclaratorChunk &Chunk : llvm::reverse(D.type_objects())) {
10831 if (Chunk.Kind == DeclaratorChunk::Paren)
10832 continue;
10833 if (Chunk.Kind != DeclaratorChunk::Function || FoundFunction) {
10834 Diag(D.getDeclSpec().getBeginLoc(),
10835 diag::err_deduction_guide_with_complex_decl)
10836 << D.getSourceRange();
10837 break;
10838 }
10839 if (!Chunk.Fun.hasTrailingReturnType()) {
10840 Diag(D.getName().getBeginLoc(),
10841 diag::err_deduction_guide_no_trailing_return_type);
10842 break;
10843 }
10844
10845 // Check that the return type is written as a specialization of
10846 // the template specified as the deduction-guide's name.
10847 ParsedType TrailingReturnType = Chunk.Fun.getTrailingReturnType();
10848 TypeSourceInfo *TSI = nullptr;
10849 QualType RetTy = GetTypeFromParser(TrailingReturnType, &TSI);
10850 assert(TSI && "deduction guide has valid type but invalid return type?")((void)0);
10851 bool AcceptableReturnType = false;
10852 bool MightInstantiateToSpecialization = false;
10853 if (auto RetTST =
10854 TSI->getTypeLoc().getAs<TemplateSpecializationTypeLoc>()) {
10855 TemplateName SpecifiedName = RetTST.getTypePtr()->getTemplateName();
10856 bool TemplateMatches =
10857 Context.hasSameTemplateName(SpecifiedName, GuidedTemplate);
10858 if (SpecifiedName.getKind() == TemplateName::Template && TemplateMatches)
10859 AcceptableReturnType = true;
10860 else {
10861 // This could still instantiate to the right type, unless we know it
10862 // names the wrong class template.
10863 auto *TD = SpecifiedName.getAsTemplateDecl();
10864 MightInstantiateToSpecialization = !(TD && isa<ClassTemplateDecl>(TD) &&
10865 !TemplateMatches);
10866 }
10867 } else if (!RetTy.hasQualifiers() && RetTy->isDependentType()) {
10868 MightInstantiateToSpecialization = true;
10869 }
10870
10871 if (!AcceptableReturnType) {
10872 Diag(TSI->getTypeLoc().getBeginLoc(),
10873 diag::err_deduction_guide_bad_trailing_return_type)
10874 << GuidedTemplate << TSI->getType()
10875 << MightInstantiateToSpecialization
10876 << TSI->getTypeLoc().getSourceRange();
10877 }
10878
10879 // Keep going to check that we don't have any inner declarator pieces (we
10880 // could still have a function returning a pointer to a function).
10881 FoundFunction = true;
10882 }
10883
10884 if (D.isFunctionDefinition())
10885 Diag(D.getIdentifierLoc(), diag::err_deduction_guide_defines_function);
10886}
10887
10888//===----------------------------------------------------------------------===//
10889// Namespace Handling
10890//===----------------------------------------------------------------------===//
10891
10892/// Diagnose a mismatch in 'inline' qualifiers when a namespace is
10893/// reopened.
10894static void DiagnoseNamespaceInlineMismatch(Sema &S, SourceLocation KeywordLoc,
10895 SourceLocation Loc,
10896 IdentifierInfo *II, bool *IsInline,
10897 NamespaceDecl *PrevNS) {
10898 assert(*IsInline != PrevNS->isInline())((void)0);
10899
10900 if (PrevNS->isInline())
10901 // The user probably just forgot the 'inline', so suggest that it
10902 // be added back.
10903 S.Diag(Loc, diag::warn_inline_namespace_reopened_noninline)
10904 << FixItHint::CreateInsertion(KeywordLoc, "inline ");
10905 else
10906 S.Diag(Loc, diag::err_inline_namespace_mismatch);
10907
10908 S.Diag(PrevNS->getLocation(), diag::note_previous_definition);
10909 *IsInline = PrevNS->isInline();
10910}
10911
10912/// ActOnStartNamespaceDef - This is called at the start of a namespace
10913/// definition.
10914Decl *Sema::ActOnStartNamespaceDef(
10915 Scope *NamespcScope, SourceLocation InlineLoc, SourceLocation NamespaceLoc,
10916 SourceLocation IdentLoc, IdentifierInfo *II, SourceLocation LBrace,
10917 const ParsedAttributesView &AttrList, UsingDirectiveDecl *&UD) {
10918 SourceLocation StartLoc = InlineLoc.isValid() ? InlineLoc : NamespaceLoc;
10919 // For anonymous namespace, take the location of the left brace.
10920 SourceLocation Loc = II ? IdentLoc : LBrace;
10921 bool IsInline = InlineLoc.isValid();
10922 bool IsInvalid = false;
10923 bool IsStd = false;
10924 bool AddToKnown = false;
10925 Scope *DeclRegionScope = NamespcScope->getParent();
10926
10927 NamespaceDecl *PrevNS = nullptr;
10928 if (II) {
10929 // C++ [namespace.def]p2:
10930 // The identifier in an original-namespace-definition shall not
10931 // have been previously defined in the declarative region in
10932 // which the original-namespace-definition appears. The
10933 // identifier in an original-namespace-definition is the name of
10934 // the namespace. Subsequently in that declarative region, it is
10935 // treated as an original-namespace-name.
10936 //
10937 // Since namespace names are unique in their scope, and we don't
10938 // look through using directives, just look for any ordinary names
10939 // as if by qualified name lookup.
10940 LookupResult R(*this, II, IdentLoc, LookupOrdinaryName,
10941 ForExternalRedeclaration);
10942 LookupQualifiedName(R, CurContext->getRedeclContext());
10943 NamedDecl *PrevDecl =
10944 R.isSingleResult() ? R.getRepresentativeDecl() : nullptr;
10945 PrevNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl);
10946
10947 if (PrevNS) {
10948 // This is an extended namespace definition.
10949 if (IsInline != PrevNS->isInline())
10950 DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, Loc, II,
10951 &IsInline, PrevNS);
10952 } else if (PrevDecl) {
10953 // This is an invalid name redefinition.
10954 Diag(Loc, diag::err_redefinition_different_kind)
10955 << II;
10956 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
10957 IsInvalid = true;
10958 // Continue on to push Namespc as current DeclContext and return it.
10959 } else if (II->isStr("std") &&
10960 CurContext->getRedeclContext()->isTranslationUnit()) {
10961 // This is the first "real" definition of the namespace "std", so update
10962 // our cache of the "std" namespace to point at this definition.
10963 PrevNS = getStdNamespace();
10964 IsStd = true;
10965 AddToKnown = !IsInline;
10966 } else {
10967 // We've seen this namespace for the first time.
10968 AddToKnown = !IsInline;
10969 }
10970 } else {
10971 // Anonymous namespaces.
10972
10973 // Determine whether the parent already has an anonymous namespace.
10974 DeclContext *Parent = CurContext->getRedeclContext();
10975 if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
10976 PrevNS = TU->getAnonymousNamespace();
10977 } else {
10978 NamespaceDecl *ND = cast<NamespaceDecl>(Parent);
10979 PrevNS = ND->getAnonymousNamespace();
10980 }
10981
10982 if (PrevNS && IsInline != PrevNS->isInline())
10983 DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, NamespaceLoc, II,
10984 &IsInline, PrevNS);
10985 }
10986
10987 NamespaceDecl *Namespc = NamespaceDecl::Create(Context, CurContext, IsInline,
10988 StartLoc, Loc, II, PrevNS);
10989 if (IsInvalid)
10990 Namespc->setInvalidDecl();
10991
10992 ProcessDeclAttributeList(DeclRegionScope, Namespc, AttrList);
10993 AddPragmaAttributes(DeclRegionScope, Namespc);
10994
10995 // FIXME: Should we be merging attributes?
10996 if (const VisibilityAttr *Attr = Namespc->getAttr<VisibilityAttr>())
10997 PushNamespaceVisibilityAttr(Attr, Loc);
10998
10999 if (IsStd)
11000 StdNamespace = Namespc;
11001 if (AddToKnown)
11002 KnownNamespaces[Namespc] = false;
11003
11004 if (II) {
11005 PushOnScopeChains(Namespc, DeclRegionScope);
11006 } else {
11007 // Link the anonymous namespace into its parent.
11008 DeclContext *Parent = CurContext->getRedeclContext();
11009 if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
11010 TU->setAnonymousNamespace(Namespc);
11011 } else {
11012 cast<NamespaceDecl>(Parent)->setAnonymousNamespace(Namespc);
11013 }
11014
11015 CurContext->addDecl(Namespc);
11016
11017 // C++ [namespace.unnamed]p1. An unnamed-namespace-definition
11018 // behaves as if it were replaced by
11019 // namespace unique { /* empty body */ }
11020 // using namespace unique;
11021 // namespace unique { namespace-body }
11022 // where all occurrences of 'unique' in a translation unit are
11023 // replaced by the same identifier and this identifier differs
11024 // from all other identifiers in the entire program.
11025
11026 // We just create the namespace with an empty name and then add an
11027 // implicit using declaration, just like the standard suggests.
11028 //
11029 // CodeGen enforces the "universally unique" aspect by giving all
11030 // declarations semantically contained within an anonymous
11031 // namespace internal linkage.
11032
11033 if (!PrevNS) {
11034 UD = UsingDirectiveDecl::Create(Context, Parent,
11035 /* 'using' */ LBrace,
11036 /* 'namespace' */ SourceLocation(),
11037 /* qualifier */ NestedNameSpecifierLoc(),
11038 /* identifier */ SourceLocation(),
11039 Namespc,
11040 /* Ancestor */ Parent);
11041 UD->setImplicit();
11042 Parent->addDecl(UD);
11043 }
11044 }
11045
11046 ActOnDocumentableDecl(Namespc);
11047
11048 // Although we could have an invalid decl (i.e. the namespace name is a
11049 // redefinition), push it as current DeclContext and try to continue parsing.
11050 // FIXME: We should be able to push Namespc here, so that the each DeclContext
11051 // for the namespace has the declarations that showed up in that particular
11052 // namespace definition.
11053 PushDeclContext(NamespcScope, Namespc);
11054 return Namespc;
11055}
11056
11057/// getNamespaceDecl - Returns the namespace a decl represents. If the decl
11058/// is a namespace alias, returns the namespace it points to.
11059static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) {
11060 if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D))
11061 return AD->getNamespace();
11062 return dyn_cast_or_null<NamespaceDecl>(D);
11063}
11064
11065/// ActOnFinishNamespaceDef - This callback is called after a namespace is
11066/// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef.
11067void Sema::ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace) {
11068 NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl);
11069 assert(Namespc && "Invalid parameter, expected NamespaceDecl")((void)0);
11070 Namespc->setRBraceLoc(RBrace);
11071 PopDeclContext();
11072 if (Namespc->hasAttr<VisibilityAttr>())
11073 PopPragmaVisibility(true, RBrace);
11074 // If this namespace contains an export-declaration, export it now.
11075 if (DeferredExportedNamespaces.erase(Namespc))
11076 Dcl->setModuleOwnershipKind(Decl::ModuleOwnershipKind::VisibleWhenImported);
11077}
11078
11079CXXRecordDecl *Sema::getStdBadAlloc() const {
11080 return cast_or_null<CXXRecordDecl>(
11081 StdBadAlloc.get(Context.getExternalSource()));
11082}
11083
11084EnumDecl *Sema::getStdAlignValT() const {
11085 return cast_or_null<EnumDecl>(StdAlignValT.get(Context.getExternalSource()));
11086}
11087
11088NamespaceDecl *Sema::getStdNamespace() const {
11089 return cast_or_null<NamespaceDecl>(
11090 StdNamespace.get(Context.getExternalSource()));
11091}
11092
11093NamespaceDecl *Sema::lookupStdExperimentalNamespace() {
11094 if (!StdExperimentalNamespaceCache) {
11095 if (auto Std = getStdNamespace()) {
11096 LookupResult Result(*this, &PP.getIdentifierTable().get("experimental"),
11097 SourceLocation(), LookupNamespaceName);
11098 if (!LookupQualifiedName(Result, Std) ||
11099 !(StdExperimentalNamespaceCache =
11100 Result.getAsSingle<NamespaceDecl>()))
11101 Result.suppressDiagnostics();
11102 }
11103 }
11104 return StdExperimentalNamespaceCache;
11105}
11106
11107namespace {
11108
11109enum UnsupportedSTLSelect {
11110 USS_InvalidMember,
11111 USS_MissingMember,
11112 USS_NonTrivial,
11113 USS_Other
11114};
11115
11116struct InvalidSTLDiagnoser {
11117 Sema &S;
11118 SourceLocation Loc;
11119 QualType TyForDiags;
11120
11121 QualType operator()(UnsupportedSTLSelect Sel = USS_Other, StringRef Name = "",
11122 const VarDecl *VD = nullptr) {
11123 {
11124 auto D = S.Diag(Loc, diag::err_std_compare_type_not_supported)
11125 << TyForDiags << ((int)Sel);
11126 if (Sel == USS_InvalidMember || Sel == USS_MissingMember) {
11127 assert(!Name.empty())((void)0);
11128 D << Name;
11129 }
11130 }
11131 if (Sel == USS_InvalidMember) {
11132 S.Diag(VD->getLocation(), diag::note_var_declared_here)
11133 << VD << VD->getSourceRange();
11134 }
11135 return QualType();
11136 }
11137};
11138} // namespace
11139
11140QualType Sema::CheckComparisonCategoryType(ComparisonCategoryType Kind,
11141 SourceLocation Loc,
11142 ComparisonCategoryUsage Usage) {
11143 assert(getLangOpts().CPlusPlus &&((void)0)
11144 "Looking for comparison category type outside of C++.")((void)0);
11145
11146 // Use an elaborated type for diagnostics which has a name containing the
11147 // prepended 'std' namespace but not any inline namespace names.
11148 auto TyForDiags = [&](ComparisonCategoryInfo *Info) {
11149 auto *NNS =
11150 NestedNameSpecifier::Create(Context, nullptr, getStdNamespace());
11151 return Context.getElaboratedType(ETK_None, NNS, Info->getType());
11152 };
11153
11154 // Check if we've already successfully checked the comparison category type
11155 // before. If so, skip checking it again.
11156 ComparisonCategoryInfo *Info = Context.CompCategories.lookupInfo(Kind);
11157 if (Info && FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)]) {
11158 // The only thing we need to check is that the type has a reachable
11159 // definition in the current context.
11160 if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type))
11161 return QualType();
11162
11163 return Info->getType();
11164 }
11165
11166 // If lookup failed
11167 if (!Info) {
11168 std::string NameForDiags = "std::";
11169 NameForDiags += ComparisonCategories::getCategoryString(Kind);
11170 Diag(Loc, diag::err_implied_comparison_category_type_not_found)
11171 << NameForDiags << (int)Usage;
11172 return QualType();
11173 }
11174
11175 assert(Info->Kind == Kind)((void)0);
11176 assert(Info->Record)((void)0);
11177
11178 // Update the Record decl in case we encountered a forward declaration on our
11179 // first pass. FIXME: This is a bit of a hack.
11180 if (Info->Record->hasDefinition())
11181 Info->Record = Info->Record->getDefinition();
11182
11183 if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type))
11184 return QualType();
11185
11186 InvalidSTLDiagnoser UnsupportedSTLError{*this, Loc, TyForDiags(Info)};
11187
11188 if (!Info->Record->isTriviallyCopyable())
11189 return UnsupportedSTLError(USS_NonTrivial);
11190
11191 for (const CXXBaseSpecifier &BaseSpec : Info->Record->bases()) {
11192 CXXRecordDecl *Base = BaseSpec.getType()->getAsCXXRecordDecl();
11193 // Tolerate empty base classes.
11194 if (Base->isEmpty())
11195 continue;
11196 // Reject STL implementations which have at least one non-empty base.
11197 return UnsupportedSTLError();
11198 }
11199
11200 // Check that the STL has implemented the types using a single integer field.
11201 // This expectation allows better codegen for builtin operators. We require:
11202 // (1) The class has exactly one field.
11203 // (2) The field is an integral or enumeration type.
11204 auto FIt = Info->Record->field_begin(), FEnd = Info->Record->field_end();
11205 if (std::distance(FIt, FEnd) != 1 ||
11206 !FIt->getType()->isIntegralOrEnumerationType()) {
11207 return UnsupportedSTLError();
11208 }
11209
11210 // Build each of the require values and store them in Info.
11211 for (ComparisonCategoryResult CCR :
11212 ComparisonCategories::getPossibleResultsForType(Kind)) {
11213 StringRef MemName = ComparisonCategories::getResultString(CCR);
11214 ComparisonCategoryInfo::ValueInfo *ValInfo = Info->lookupValueInfo(CCR);
11215
11216 if (!ValInfo)
11217 return UnsupportedSTLError(USS_MissingMember, MemName);
11218
11219 VarDecl *VD = ValInfo->VD;
11220 assert(VD && "should not be null!")((void)0);
11221
11222 // Attempt to diagnose reasons why the STL definition of this type
11223 // might be foobar, including it failing to be a constant expression.
11224 // TODO Handle more ways the lookup or result can be invalid.
11225 if (!VD->isStaticDataMember() ||
11226 !VD->isUsableInConstantExpressions(Context))
11227 return UnsupportedSTLError(USS_InvalidMember, MemName, VD);
11228
11229 // Attempt to evaluate the var decl as a constant expression and extract
11230 // the value of its first field as a ICE. If this fails, the STL
11231 // implementation is not supported.
11232 if (!ValInfo->hasValidIntValue())
11233 return UnsupportedSTLError();
11234
11235 MarkVariableReferenced(Loc, VD);
11236 }
11237
11238 // We've successfully built the required types and expressions. Update
11239 // the cache and return the newly cached value.
11240 FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)] = true;
11241 return Info->getType();
11242}
11243
11244/// Retrieve the special "std" namespace, which may require us to
11245/// implicitly define the namespace.
11246NamespaceDecl *Sema::getOrCreateStdNamespace() {
11247 if (!StdNamespace) {
11248 // The "std" namespace has not yet been defined, so build one implicitly.
11249 StdNamespace = NamespaceDecl::Create(Context,
11250 Context.getTranslationUnitDecl(),
11251 /*Inline=*/false,
11252 SourceLocation(), SourceLocation(),
11253 &PP.getIdentifierTable().get("std"),
11254 /*PrevDecl=*/nullptr);
11255 getStdNamespace()->setImplicit(true);
11256 }
11257
11258 return getStdNamespace();
11259}
11260
11261bool Sema::isStdInitializerList(QualType Ty, QualType *Element) {
11262 assert(getLangOpts().CPlusPlus &&((void)0)
11263 "Looking for std::initializer_list outside of C++.")((void)0);
11264
11265 // We're looking for implicit instantiations of
11266 // template <typename E> class std::initializer_list.
11267
11268 if (!StdNamespace) // If we haven't seen namespace std yet, this can't be it.
11269 return false;
11270
11271 ClassTemplateDecl *Template = nullptr;
11272 const TemplateArgument *Arguments = nullptr;
11273
11274 if (const RecordType *RT = Ty->getAs<RecordType>()) {
11275
11276 ClassTemplateSpecializationDecl *Specialization =
11277 dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl());
11278 if (!Specialization)
11279 return false;
11280
11281 Template = Specialization->getSpecializedTemplate();
11282 Arguments = Specialization->getTemplateArgs().data();
11283 } else if (const TemplateSpecializationType *TST =
11284 Ty->getAs<TemplateSpecializationType>()) {
11285 Template = dyn_cast_or_null<ClassTemplateDecl>(
11286 TST->getTemplateName().getAsTemplateDecl());
11287 Arguments = TST->getArgs();
11288 }
11289 if (!Template)
11290 return false;
11291
11292 if (!StdInitializerList) {
11293 // Haven't recognized std::initializer_list yet, maybe this is it.
11294 CXXRecordDecl *TemplateClass = Template->getTemplatedDecl();
11295 if (TemplateClass->getIdentifier() !=
11296 &PP.getIdentifierTable().get("initializer_list") ||
11297 !getStdNamespace()->InEnclosingNamespaceSetOf(
11298 TemplateClass->getDeclContext()))
11299 return false;
11300 // This is a template called std::initializer_list, but is it the right
11301 // template?
11302 TemplateParameterList *Params = Template->getTemplateParameters();
11303 if (Params->getMinRequiredArguments() != 1)
11304 return false;
11305 if (!isa<TemplateTypeParmDecl>(Params->getParam(0)))
11306 return false;
11307
11308 // It's the right template.
11309 StdInitializerList = Template;
11310 }
11311
11312 if (Template->getCanonicalDecl() != StdInitializerList->getCanonicalDecl())
11313 return false;
11314
11315 // This is an instance of std::initializer_list. Find the argument type.
11316 if (Element)
11317 *Element = Arguments[0].getAsType();
11318 return true;
11319}
11320
11321static ClassTemplateDecl *LookupStdInitializerList(Sema &S, SourceLocation Loc){
11322 NamespaceDecl *Std = S.getStdNamespace();
11323 if (!Std) {
11324 S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
11325 return nullptr;
11326 }
11327
11328 LookupResult Result(S, &S.PP.getIdentifierTable().get("initializer_list"),
11329 Loc, Sema::LookupOrdinaryName);
11330 if (!S.LookupQualifiedName(Result, Std)) {
11331 S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
11332 return nullptr;
11333 }
11334 ClassTemplateDecl *Template = Result.getAsSingle<ClassTemplateDecl>();
11335 if (!Template) {
11336 Result.suppressDiagnostics();
11337 // We found something weird. Complain about the first thing we found.
11338 NamedDecl *Found = *Result.begin();
11339 S.Diag(Found->getLocation(), diag::err_malformed_std_initializer_list);
11340 return nullptr;
11341 }
11342
11343 // We found some template called std::initializer_list. Now verify that it's
11344 // correct.
11345 TemplateParameterList *Params = Template->getTemplateParameters();
11346 if (Params->getMinRequiredArguments() != 1 ||
11347 !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
11348 S.Diag(Template->getLocation(), diag::err_malformed_std_initializer_list);
11349 return nullptr;
11350 }
11351
11352 return Template;
11353}
11354
11355QualType Sema::BuildStdInitializerList(QualType Element, SourceLocation Loc) {
11356 if (!StdInitializerList) {
11357 StdInitializerList = LookupStdInitializerList(*this, Loc);
11358 if (!StdInitializerList)
11359 return QualType();
11360 }
11361
11362 TemplateArgumentListInfo Args(Loc, Loc);
11363 Args.addArgument(TemplateArgumentLoc(TemplateArgument(Element),
11364 Context.getTrivialTypeSourceInfo(Element,
11365 Loc)));
11366 return Context.getCanonicalType(
11367 CheckTemplateIdType(TemplateName(StdInitializerList), Loc, Args));
11368}
11369
11370bool Sema::isInitListConstructor(const FunctionDecl *Ctor) {
11371 // C++ [dcl.init.list]p2:
11372 // A constructor is an initializer-list constructor if its first parameter
11373 // is of type std::initializer_list<E> or reference to possibly cv-qualified
11374 // std::initializer_list<E> for some type E, and either there are no other
11375 // parameters or else all other parameters have default arguments.
11376 if (!Ctor->hasOneParamOrDefaultArgs())
11377 return false;
11378
11379 QualType ArgType = Ctor->getParamDecl(0)->getType();
11380 if (const ReferenceType *RT = ArgType->getAs<ReferenceType>())
11381 ArgType = RT->getPointeeType().getUnqualifiedType();
11382
11383 return isStdInitializerList(ArgType, nullptr);
11384}
11385
11386/// Determine whether a using statement is in a context where it will be
11387/// apply in all contexts.
11388static bool IsUsingDirectiveInToplevelContext(DeclContext *CurContext) {
11389 switch (CurContext->getDeclKind()) {
11390 case Decl::TranslationUnit:
11391 return true;
11392 case Decl::LinkageSpec:
11393 return IsUsingDirectiveInToplevelContext(CurContext->getParent());
11394 default:
11395 return false;
11396 }
11397}
11398
11399namespace {
11400
11401// Callback to only accept typo corrections that are namespaces.
11402class NamespaceValidatorCCC final : public CorrectionCandidateCallback {
11403public:
11404 bool ValidateCandidate(const TypoCorrection &candidate) override {
11405 if (NamedDecl *ND = candidate.getCorrectionDecl())
11406 return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND);
11407 return false;
11408 }
11409
11410 std::unique_ptr<CorrectionCandidateCallback> clone() override {
11411 return std::make_unique<NamespaceValidatorCCC>(*this);
11412 }
11413};
11414
11415}
11416
11417static bool TryNamespaceTypoCorrection(Sema &S, LookupResult &R, Scope *Sc,
11418 CXXScopeSpec &SS,
11419 SourceLocation IdentLoc,
11420 IdentifierInfo *Ident) {
11421 R.clear();
11422 NamespaceValidatorCCC CCC{};
11423 if (TypoCorrection Corrected =
11424 S.CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), Sc, &SS, CCC,
11425 Sema::CTK_ErrorRecovery)) {
11426 if (DeclContext *DC = S.computeDeclContext(SS, false)) {
11427 std::string CorrectedStr(Corrected.getAsString(S.getLangOpts()));
11428 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
11429 Ident->getName().equals(CorrectedStr);
11430 S.diagnoseTypo(Corrected,
11431 S.PDiag(diag::err_using_directive_member_suggest)
11432 << Ident << DC << DroppedSpecifier << SS.getRange(),
11433 S.PDiag(diag::note_namespace_defined_here));
11434 } else {
11435 S.diagnoseTypo(Corrected,
11436 S.PDiag(diag::err_using_directive_suggest) << Ident,
11437 S.PDiag(diag::note_namespace_defined_here));
11438 }
11439 R.addDecl(Corrected.getFoundDecl());
11440 return true;
11441 }
11442 return false;
11443}
11444
11445Decl *Sema::ActOnUsingDirective(Scope *S, SourceLocation UsingLoc,
11446 SourceLocation NamespcLoc, CXXScopeSpec &SS,
11447 SourceLocation IdentLoc,
11448 IdentifierInfo *NamespcName,
11449 const ParsedAttributesView &AttrList) {
11450 assert(!SS.isInvalid() && "Invalid CXXScopeSpec.")((void)0);
11451 assert(NamespcName && "Invalid NamespcName.")((void)0);
11452 assert(IdentLoc.isValid() && "Invalid NamespceName location.")((void)0);
11453
11454 // This can only happen along a recovery path.
11455 while (S->isTemplateParamScope())
11456 S = S->getParent();
11457 assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.")((void)0);
11458
11459 UsingDirectiveDecl *UDir = nullptr;
11460 NestedNameSpecifier *Qualifier = nullptr;
11461 if (SS.isSet())
11462 Qualifier = SS.getScopeRep();
11463
11464 // Lookup namespace name.
11465 LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName);
11466 LookupParsedName(R, S, &SS);
11467 if (R.isAmbiguous())
11468 return nullptr;
11469
11470 if (R.empty()) {
11471 R.clear();
11472 // Allow "using namespace std;" or "using namespace ::std;" even if
11473 // "std" hasn't been defined yet, for GCC compatibility.
11474 if ((!Qualifier || Qualifier->getKind() == NestedNameSpecifier::Global) &&
11475 NamespcName->isStr("std")) {
11476 Diag(IdentLoc, diag::ext_using_undefined_std);
11477 R.addDecl(getOrCreateStdNamespace());
11478 R.resolveKind();
11479 }
11480 // Otherwise, attempt typo correction.
11481 else TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, NamespcName);
11482 }
11483
11484 if (!R.empty()) {
11485 NamedDecl *Named = R.getRepresentativeDecl();
11486 NamespaceDecl *NS = R.getAsSingle<NamespaceDecl>();
11487 assert(NS && "expected namespace decl")((void)0);
11488
11489 // The use of a nested name specifier may trigger deprecation warnings.
11490 DiagnoseUseOfDecl(Named, IdentLoc);
11491
11492 // C++ [namespace.udir]p1:
11493 // A using-directive specifies that the names in the nominated
11494 // namespace can be used in the scope in which the
11495 // using-directive appears after the using-directive. During
11496 // unqualified name lookup (3.4.1), the names appear as if they
11497 // were declared in the nearest enclosing namespace which
11498 // contains both the using-directive and the nominated
11499 // namespace. [Note: in this context, "contains" means "contains
11500 // directly or indirectly". ]
11501
11502 // Find enclosing context containing both using-directive and
11503 // nominated namespace.
11504 DeclContext *CommonAncestor = NS;
11505 while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
11506 CommonAncestor = CommonAncestor->getParent();
11507
11508 UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc,
11509 SS.getWithLocInContext(Context),
11510 IdentLoc, Named, CommonAncestor);
11511
11512 if (IsUsingDirectiveInToplevelContext(CurContext) &&
11513 !SourceMgr.isInMainFile(SourceMgr.getExpansionLoc(IdentLoc))) {
11514 Diag(IdentLoc, diag::warn_using_directive_in_header);
11515 }
11516
11517 PushUsingDirective(S, UDir);
11518 } else {
11519 Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
11520 }
11521
11522 if (UDir)
11523 ProcessDeclAttributeList(S, UDir, AttrList);
11524
11525 return UDir;
11526}
11527
11528void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) {
11529 // If the scope has an associated entity and the using directive is at
11530 // namespace or translation unit scope, add the UsingDirectiveDecl into
11531 // its lookup structure so qualified name lookup can find it.
11532 DeclContext *Ctx = S->getEntity();
11533 if (Ctx && !Ctx->isFunctionOrMethod())
11534 Ctx->addDecl(UDir);
11535 else
11536 // Otherwise, it is at block scope. The using-directives will affect lookup
11537 // only to the end of the scope.
11538 S->PushUsingDirective(UDir);
11539}
11540
11541Decl *Sema::ActOnUsingDeclaration(Scope *S, AccessSpecifier AS,
11542 SourceLocation UsingLoc,
11543 SourceLocation TypenameLoc, CXXScopeSpec &SS,
11544 UnqualifiedId &Name,
11545 SourceLocation EllipsisLoc,
11546 const ParsedAttributesView &AttrList) {
11547 assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.")((void)0);
11548
11549 if (SS.isEmpty()) {
11550 Diag(Name.getBeginLoc(), diag::err_using_requires_qualname);
11551 return nullptr;
11552 }
11553
11554 switch (Name.getKind()) {
11555 case UnqualifiedIdKind::IK_ImplicitSelfParam:
11556 case UnqualifiedIdKind::IK_Identifier:
11557 case UnqualifiedIdKind::IK_OperatorFunctionId:
11558 case UnqualifiedIdKind::IK_LiteralOperatorId:
11559 case UnqualifiedIdKind::IK_ConversionFunctionId:
11560 break;
11561
11562 case UnqualifiedIdKind::IK_ConstructorName:
11563 case UnqualifiedIdKind::IK_ConstructorTemplateId:
11564 // C++11 inheriting constructors.
11565 Diag(Name.getBeginLoc(),
11566 getLangOpts().CPlusPlus11
11567 ? diag::warn_cxx98_compat_using_decl_constructor
11568 : diag::err_using_decl_constructor)
11569 << SS.getRange();
11570
11571 if (getLangOpts().CPlusPlus11) break;
11572
11573 return nullptr;
11574
11575 case UnqualifiedIdKind::IK_DestructorName:
11576 Diag(Name.getBeginLoc(), diag::err_using_decl_destructor) << SS.getRange();
11577 return nullptr;
11578
11579 case UnqualifiedIdKind::IK_TemplateId:
11580 Diag(Name.getBeginLoc(), diag::err_using_decl_template_id)
11581 << SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc);
11582 return nullptr;
11583
11584 case UnqualifiedIdKind::IK_DeductionGuideName:
11585 llvm_unreachable("cannot parse qualified deduction guide name")__builtin_unreachable();
11586 }
11587
11588 DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);
11589 DeclarationName TargetName = TargetNameInfo.getName();
11590 if (!TargetName)
11591 return nullptr;
11592
11593 // Warn about access declarations.
11594 if (UsingLoc.isInvalid()) {
11595 Diag(Name.getBeginLoc(), getLangOpts().CPlusPlus11
11596 ? diag::err_access_decl
11597 : diag::warn_access_decl_deprecated)
11598 << FixItHint::CreateInsertion(SS.getRange().getBegin(), "using ");
11599 }
11600
11601 if (EllipsisLoc.isInvalid()) {
11602 if (DiagnoseUnexpandedParameterPack(SS, UPPC_UsingDeclaration) ||
11603 DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC_UsingDeclaration))
11604 return nullptr;
11605 } else {
11606 if (!SS.getScopeRep()->containsUnexpandedParameterPack() &&
11607 !TargetNameInfo.containsUnexpandedParameterPack()) {
11608 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
11609 << SourceRange(SS.getBeginLoc(), TargetNameInfo.getEndLoc());
11610 EllipsisLoc = SourceLocation();
11611 }
11612 }
11613
11614 NamedDecl *UD =
11615 BuildUsingDeclaration(S, AS, UsingLoc, TypenameLoc.isValid(), TypenameLoc,
11616 SS, TargetNameInfo, EllipsisLoc, AttrList,
11617 /*IsInstantiation*/ false,
11618 AttrList.hasAttribute(ParsedAttr::AT_UsingIfExists));
11619 if (UD)
11620 PushOnScopeChains(UD, S, /*AddToContext*/ false);
11621
11622 return UD;
11623}
11624
11625Decl *Sema::ActOnUsingEnumDeclaration(Scope *S, AccessSpecifier AS,
11626 SourceLocation UsingLoc,
11627 SourceLocation EnumLoc,
11628 const DeclSpec &DS) {
11629 switch (DS.getTypeSpecType()) {
11630 case DeclSpec::TST_error:
11631 // This will already have been diagnosed
11632 return nullptr;
11633
11634 case DeclSpec::TST_enum:
11635 break;
11636
11637 case DeclSpec::TST_typename:
11638 Diag(DS.getTypeSpecTypeLoc(), diag::err_using_enum_is_dependent);
11639 return nullptr;
11640
11641 default:
11642 llvm_unreachable("unexpected DeclSpec type")__builtin_unreachable();
11643 }
11644
11645 // As with enum-decls, we ignore attributes for now.
11646 auto *Enum = cast<EnumDecl>(DS.getRepAsDecl());
11647 if (auto *Def = Enum->getDefinition())
11648 Enum = Def;
11649
11650 auto *UD = BuildUsingEnumDeclaration(S, AS, UsingLoc, EnumLoc,
11651 DS.getTypeSpecTypeNameLoc(), Enum);
11652 if (UD)
11653 PushOnScopeChains(UD, S, /*AddToContext*/ false);
11654
11655 return UD;
11656}
11657
11658/// Determine whether a using declaration considers the given
11659/// declarations as "equivalent", e.g., if they are redeclarations of
11660/// the same entity or are both typedefs of the same type.
11661static bool
11662IsEquivalentForUsingDecl(ASTContext &Context, NamedDecl *D1, NamedDecl *D2) {
11663 if (D1->getCanonicalDecl() == D2->getCanonicalDecl())
11664 return true;
11665
11666 if (TypedefNameDecl *TD1 = dyn_cast<TypedefNameDecl>(D1))
11667 if (TypedefNameDecl *TD2 = dyn_cast<TypedefNameDecl>(D2))
11668 return Context.hasSameType(TD1->getUnderlyingType(),
11669 TD2->getUnderlyingType());
11670
11671 // Two using_if_exists using-declarations are equivalent if both are
11672 // unresolved.
11673 if (isa<UnresolvedUsingIfExistsDecl>(D1) &&
11674 isa<UnresolvedUsingIfExistsDecl>(D2))
11675 return true;
11676
11677 return false;
11678}
11679
11680
11681/// Determines whether to create a using shadow decl for a particular
11682/// decl, given the set of decls existing prior to this using lookup.
11683bool Sema::CheckUsingShadowDecl(BaseUsingDecl *BUD, NamedDecl *Orig,
11684 const LookupResult &Previous,
11685 UsingShadowDecl *&PrevShadow) {
11686 // Diagnose finding a decl which is not from a base class of the
11687 // current class. We do this now because there are cases where this
11688 // function will silently decide not to build a shadow decl, which
11689 // will pre-empt further diagnostics.
11690 //
11691 // We don't need to do this in C++11 because we do the check once on
11692 // the qualifier.
11693 //
11694 // FIXME: diagnose the following if we care enough:
11695 // struct A { int foo; };
11696 // struct B : A { using A::foo; };
11697 // template <class T> struct C : A {};
11698 // template <class T> struct D : C<T> { using B::foo; } // <---
11699 // This is invalid (during instantiation) in C++03 because B::foo
11700 // resolves to the using decl in B, which is not a base class of D<T>.
11701 // We can't diagnose it immediately because C<T> is an unknown
11702 // specialization. The UsingShadowDecl in D<T> then points directly
11703 // to A::foo, which will look well-formed when we instantiate.
11704 // The right solution is to not collapse the shadow-decl chain.
11705 if (!getLangOpts().CPlusPlus11 && CurContext->isRecord())
11706 if (auto *Using = dyn_cast<UsingDecl>(BUD)) {
11707 DeclContext *OrigDC = Orig->getDeclContext();
11708
11709 // Handle enums and anonymous structs.
11710 if (isa<EnumDecl>(OrigDC))
11711 OrigDC = OrigDC->getParent();
11712 CXXRecordDecl *OrigRec = cast<CXXRecordDecl>(OrigDC);
11713 while (OrigRec->isAnonymousStructOrUnion())
11714 OrigRec = cast<CXXRecordDecl>(OrigRec->getDeclContext());
11715
11716 if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(OrigRec)) {
11717 if (OrigDC == CurContext) {
11718 Diag(Using->getLocation(),
11719 diag::err_using_decl_nested_name_specifier_is_current_class)
11720 << Using->getQualifierLoc().getSourceRange();
11721 Diag(Orig->getLocation(), diag::note_using_decl_target);
11722 Using->setInvalidDecl();
11723 return true;
11724 }
11725
11726 Diag(Using->getQualifierLoc().getBeginLoc(),
11727 diag::err_using_decl_nested_name_specifier_is_not_base_class)
11728 << Using->getQualifier() << cast<CXXRecordDecl>(CurContext)
11729 << Using->getQualifierLoc().getSourceRange();
11730 Diag(Orig->getLocation(), diag::note_using_decl_target);
11731 Using->setInvalidDecl();
11732 return true;
11733 }
11734 }
11735
11736 if (Previous.empty()) return false;
11737
11738 NamedDecl *Target = Orig;
11739 if (isa<UsingShadowDecl>(Target))
11740 Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
11741
11742 // If the target happens to be one of the previous declarations, we
11743 // don't have a conflict.
11744 //
11745 // FIXME: but we might be increasing its access, in which case we
11746 // should redeclare it.
11747 NamedDecl *NonTag = nullptr, *Tag = nullptr;
11748 bool FoundEquivalentDecl = false;
11749 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
11750 I != E; ++I) {
11751 NamedDecl *D = (*I)->getUnderlyingDecl();
11752 // We can have UsingDecls in our Previous results because we use the same
11753 // LookupResult for checking whether the UsingDecl itself is a valid
11754 // redeclaration.
11755 if (isa<UsingDecl>(D) || isa<UsingPackDecl>(D) || isa<UsingEnumDecl>(D))
11756 continue;
11757
11758 if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
11759 // C++ [class.mem]p19:
11760 // If T is the name of a class, then [every named member other than
11761 // a non-static data member] shall have a name different from T
11762 if (RD->isInjectedClassName() && !isa<FieldDecl>(Target) &&
11763 !isa<IndirectFieldDecl>(Target) &&
11764 !isa<UnresolvedUsingValueDecl>(Target) &&
11765 DiagnoseClassNameShadow(
11766 CurContext,
11767 DeclarationNameInfo(BUD->getDeclName(), BUD->getLocation())))
11768 return true;
11769 }
11770
11771 if (IsEquivalentForUsingDecl(Context, D, Target)) {
11772 if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(*I))
11773 PrevShadow = Shadow;
11774 FoundEquivalentDecl = true;
11775 } else if (isEquivalentInternalLinkageDeclaration(D, Target)) {
11776 // We don't conflict with an existing using shadow decl of an equivalent
11777 // declaration, but we're not a redeclaration of it.
11778 FoundEquivalentDecl = true;
11779 }
11780
11781 if (isVisible(D))
11782 (isa<TagDecl>(D) ? Tag : NonTag) = D;
11783 }
11784
11785 if (FoundEquivalentDecl)
11786 return false;
11787
11788 // Always emit a diagnostic for a mismatch between an unresolved
11789 // using_if_exists and a resolved using declaration in either direction.
11790 if (isa<UnresolvedUsingIfExistsDecl>(Target) !=
11791 (isa_and_nonnull<UnresolvedUsingIfExistsDecl>(NonTag))) {
11792 if (!NonTag && !Tag)
11793 return false;
11794 Diag(BUD->getLocation(), diag::err_using_decl_conflict);
11795 Diag(Target->getLocation(), diag::note_using_decl_target);
11796 Diag((NonTag ? NonTag : Tag)->getLocation(),
11797 diag::note_using_decl_conflict);
11798 BUD->setInvalidDecl();
11799 return true;
11800 }
11801
11802 if (FunctionDecl *FD = Target->getAsFunction()) {
11803 NamedDecl *OldDecl = nullptr;
11804 switch (CheckOverload(nullptr, FD, Previous, OldDecl,
11805 /*IsForUsingDecl*/ true)) {
11806 case Ovl_Overload:
11807 return false;
11808
11809 case Ovl_NonFunction:
11810 Diag(BUD->getLocation(), diag::err_using_decl_conflict);
11811 break;
11812
11813 // We found a decl with the exact signature.
11814 case Ovl_Match:
11815 // If we're in a record, we want to hide the target, so we
11816 // return true (without a diagnostic) to tell the caller not to
11817 // build a shadow decl.
11818 if (CurContext->isRecord())
11819 return true;
11820
11821 // If we're not in a record, this is an error.
11822 Diag(BUD->getLocation(), diag::err_using_decl_conflict);
11823 break;
11824 }
11825
11826 Diag(Target->getLocation(), diag::note_using_decl_target);
11827 Diag(OldDecl->getLocation(), diag::note_using_decl_conflict);
11828 BUD->setInvalidDecl();
11829 return true;
11830 }
11831
11832 // Target is not a function.
11833
11834 if (isa<TagDecl>(Target)) {
11835 // No conflict between a tag and a non-tag.
11836 if (!Tag) return false;
11837
11838 Diag(BUD->getLocation(), diag::err_using_decl_conflict);
11839 Diag(Target->getLocation(), diag::note_using_decl_target);
11840 Diag(Tag->getLocation(), diag::note_using_decl_conflict);
11841 BUD->setInvalidDecl();
11842 return true;
11843 }
11844
11845 // No conflict between a tag and a non-tag.
11846 if (!NonTag) return false;
11847
11848 Diag(BUD->getLocation(), diag::err_using_decl_conflict);
11849 Diag(Target->getLocation(), diag::note_using_decl_target);
11850 Diag(NonTag->getLocation(), diag::note_using_decl_conflict);
11851 BUD->setInvalidDecl();
11852 return true;
11853}
11854
11855/// Determine whether a direct base class is a virtual base class.
11856static bool isVirtualDirectBase(CXXRecordDecl *Derived, CXXRecordDecl *Base) {
11857 if (!Derived->getNumVBases())
11858 return false;
11859 for (auto &B : Derived->bases())
11860 if (B.getType()->getAsCXXRecordDecl() == Base)
11861 return B.isVirtual();
11862 llvm_unreachable("not a direct base class")__builtin_unreachable();
11863}
11864
11865/// Builds a shadow declaration corresponding to a 'using' declaration.
11866UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S, BaseUsingDecl *BUD,
11867 NamedDecl *Orig,
11868 UsingShadowDecl *PrevDecl) {
11869 // If we resolved to another shadow declaration, just coalesce them.
11870 NamedDecl *Target = Orig;
11871 if (isa<UsingShadowDecl>(Target)) {
11872 Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
11873 assert(!isa<UsingShadowDecl>(Target) && "nested shadow declaration")((void)0);
11874 }
11875
11876 NamedDecl *NonTemplateTarget = Target;
11877 if (auto *TargetTD = dyn_cast<TemplateDecl>(Target))
11878 NonTemplateTarget = TargetTD->getTemplatedDecl();
11879
11880 UsingShadowDecl *Shadow;
11881 if (NonTemplateTarget && isa<CXXConstructorDecl>(NonTemplateTarget)) {
11882 UsingDecl *Using = cast<UsingDecl>(BUD);
11883 bool IsVirtualBase =
11884 isVirtualDirectBase(cast<CXXRecordDecl>(CurContext),
11885 Using->getQualifier()->getAsRecordDecl());
11886 Shadow = ConstructorUsingShadowDecl::Create(
11887 Context, CurContext, Using->getLocation(), Using, Orig, IsVirtualBase);
11888 } else {
11889 Shadow = UsingShadowDecl::Create(Context, CurContext, BUD->getLocation(),
11890 Target->getDeclName(), BUD, Target);
11891 }
11892 BUD->addShadowDecl(Shadow);
11893
11894 Shadow->setAccess(BUD->getAccess());
11895 if (Orig->isInvalidDecl() || BUD->isInvalidDecl())
11896 Shadow->setInvalidDecl();
11897
11898 Shadow->setPreviousDecl(PrevDecl);
11899
11900 if (S)
11901 PushOnScopeChains(Shadow, S);
11902 else
11903 CurContext->addDecl(Shadow);
11904
11905
11906 return Shadow;
11907}
11908
11909/// Hides a using shadow declaration. This is required by the current
11910/// using-decl implementation when a resolvable using declaration in a
11911/// class is followed by a declaration which would hide or override
11912/// one or more of the using decl's targets; for example:
11913///
11914/// struct Base { void foo(int); };
11915/// struct Derived : Base {
11916/// using Base::foo;
11917/// void foo(int);
11918/// };
11919///
11920/// The governing language is C++03 [namespace.udecl]p12:
11921///
11922/// When a using-declaration brings names from a base class into a
11923/// derived class scope, member functions in the derived class
11924/// override and/or hide member functions with the same name and
11925/// parameter types in a base class (rather than conflicting).
11926///
11927/// There are two ways to implement this:
11928/// (1) optimistically create shadow decls when they're not hidden
11929/// by existing declarations, or
11930/// (2) don't create any shadow decls (or at least don't make them
11931/// visible) until we've fully parsed/instantiated the class.
11932/// The problem with (1) is that we might have to retroactively remove
11933/// a shadow decl, which requires several O(n) operations because the
11934/// decl structures are (very reasonably) not designed for removal.
11935/// (2) avoids this but is very fiddly and phase-dependent.
11936void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) {
11937 if (Shadow->getDeclName().getNameKind() ==
11938 DeclarationName::CXXConversionFunctionName)
11939 cast<CXXRecordDecl>(Shadow->getDeclContext())->removeConversion(Shadow);
11940
11941 // Remove it from the DeclContext...
11942 Shadow->getDeclContext()->removeDecl(Shadow);
11943
11944 // ...and the scope, if applicable...
11945 if (S) {
11946 S->RemoveDecl(Shadow);
11947 IdResolver.RemoveDecl(Shadow);
11948 }
11949
11950 // ...and the using decl.
11951 Shadow->getIntroducer()->removeShadowDecl(Shadow);
11952
11953 // TODO: complain somehow if Shadow was used. It shouldn't
11954 // be possible for this to happen, because...?
11955}
11956
11957/// Find the base specifier for a base class with the given type.
11958static CXXBaseSpecifier *findDirectBaseWithType(CXXRecordDecl *Derived,
11959 QualType DesiredBase,
11960 bool &AnyDependentBases) {
11961 // Check whether the named type is a direct base class.
11962 CanQualType CanonicalDesiredBase = DesiredBase->getCanonicalTypeUnqualified()
11963 .getUnqualifiedType();
11964 for (auto &Base : Derived->bases()) {
11965 CanQualType BaseType = Base.getType()->getCanonicalTypeUnqualified();
11966 if (CanonicalDesiredBase == BaseType)
11967 return &Base;
11968 if (BaseType->isDependentType())
11969 AnyDependentBases = true;
11970 }
11971 return nullptr;
11972}
11973
11974namespace {
11975class UsingValidatorCCC final : public CorrectionCandidateCallback {
11976public:
11977 UsingValidatorCCC(bool HasTypenameKeyword, bool IsInstantiation,
11978 NestedNameSpecifier *NNS, CXXRecordDecl *RequireMemberOf)
11979 : HasTypenameKeyword(HasTypenameKeyword),
11980 IsInstantiation(IsInstantiation), OldNNS(NNS),
11981 RequireMemberOf(RequireMemberOf) {}
11982
11983 bool ValidateCandidate(const TypoCorrection &Candidate) override {
11984 NamedDecl *ND = Candidate.getCorrectionDecl();
11985
11986 // Keywords are not valid here.
11987 if (!ND || isa<NamespaceDecl>(ND))
11988 return false;
11989
11990 // Completely unqualified names are invalid for a 'using' declaration.
11991 if (Candidate.WillReplaceSpecifier() && !Candidate.getCorrectionSpecifier())
11992 return false;
11993
11994 // FIXME: Don't correct to a name that CheckUsingDeclRedeclaration would
11995 // reject.
11996
11997 if (RequireMemberOf) {
11998 auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND);
11999 if (FoundRecord && FoundRecord->isInjectedClassName()) {
12000 // No-one ever wants a using-declaration to name an injected-class-name
12001 // of a base class, unless they're declaring an inheriting constructor.
12002 ASTContext &Ctx = ND->getASTContext();
12003 if (!Ctx.getLangOpts().CPlusPlus11)
12004 return false;
12005 QualType FoundType = Ctx.getRecordType(FoundRecord);
12006
12007 // Check that the injected-class-name is named as a member of its own
12008 // type; we don't want to suggest 'using Derived::Base;', since that
12009 // means something else.
12010 NestedNameSpecifier *Specifier =
12011 Candidate.WillReplaceSpecifier()
12012 ? Candidate.getCorrectionSpecifier()
12013 : OldNNS;
12014 if (!Specifier->getAsType() ||
12015 !Ctx.hasSameType(QualType(Specifier->getAsType(), 0), FoundType))
12016 return false;
12017
12018 // Check that this inheriting constructor declaration actually names a
12019 // direct base class of the current class.
12020 bool AnyDependentBases = false;
12021 if (!findDirectBaseWithType(RequireMemberOf,
12022 Ctx.getRecordType(FoundRecord),
12023 AnyDependentBases) &&
12024 !AnyDependentBases)
12025 return false;
12026 } else {
12027 auto *RD = dyn_cast<CXXRecordDecl>(ND->getDeclContext());
12028 if (!RD || RequireMemberOf->isProvablyNotDerivedFrom(RD))
12029 return false;
12030
12031 // FIXME: Check that the base class member is accessible?
12032 }
12033 } else {
12034 auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND);
12035 if (FoundRecord && FoundRecord->isInjectedClassName())
12036 return false;
12037 }
12038
12039 if (isa<TypeDecl>(ND))
12040 return HasTypenameKeyword || !IsInstantiation;
12041
12042 return !HasTypenameKeyword;
12043 }
12044
12045 std::unique_ptr<CorrectionCandidateCallback> clone() override {
12046 return std::make_unique<UsingValidatorCCC>(*this);
12047 }
12048
12049private:
12050 bool HasTypenameKeyword;
12051 bool IsInstantiation;
12052 NestedNameSpecifier *OldNNS;
12053 CXXRecordDecl *RequireMemberOf;
12054};
12055} // end anonymous namespace
12056
12057/// Remove decls we can't actually see from a lookup being used to declare
12058/// shadow using decls.
12059///
12060/// \param S - The scope of the potential shadow decl
12061/// \param Previous - The lookup of a potential shadow decl's name.
12062void Sema::FilterUsingLookup(Scope *S, LookupResult &Previous) {
12063 // It is really dumb that we have to do this.
12064 LookupResult::Filter F = Previous.makeFilter();
12065 while (F.hasNext()) {
12066 NamedDecl *D = F.next();
12067 if (!isDeclInScope(D, CurContext, S))
12068 F.erase();
12069 // If we found a local extern declaration that's not ordinarily visible,
12070 // and this declaration is being added to a non-block scope, ignore it.
12071 // We're only checking for scope conflicts here, not also for violations
12072 // of the linkage rules.
12073 else if (!CurContext->isFunctionOrMethod() && D->isLocalExternDecl() &&
12074 !(D->getIdentifierNamespace() & Decl::IDNS_Ordinary))
12075 F.erase();
12076 }
12077 F.done();
12078}
12079
12080/// Builds a using declaration.
12081///
12082/// \param IsInstantiation - Whether this call arises from an
12083/// instantiation of an unresolved using declaration. We treat
12084/// the lookup differently for these declarations.
12085NamedDecl *Sema::BuildUsingDeclaration(
12086 Scope *S, AccessSpecifier AS, SourceLocation UsingLoc,
12087 bool HasTypenameKeyword, SourceLocation TypenameLoc, CXXScopeSpec &SS,
12088 DeclarationNameInfo NameInfo, SourceLocation EllipsisLoc,
12089 const ParsedAttributesView &AttrList, bool IsInstantiation,
12090 bool IsUsingIfExists) {
12091 assert(!SS.isInvalid() && "Invalid CXXScopeSpec.")((void)0);
12092 SourceLocation IdentLoc = NameInfo.getLoc();
12093 assert(IdentLoc.isValid() && "Invalid TargetName location.")((void)0);
12094
12095 // FIXME: We ignore attributes for now.
12096
12097 // For an inheriting constructor declaration, the name of the using
12098 // declaration is the name of a constructor in this class, not in the
12099 // base class.
12100 DeclarationNameInfo UsingName = NameInfo;
12101 if (UsingName.getName().getNameKind() == DeclarationName::CXXConstructorName)
12102 if (auto *RD = dyn_cast<CXXRecordDecl>(CurContext))
12103 UsingName.setName(Context.DeclarationNames.getCXXConstructorName(
12104 Context.getCanonicalType(Context.getRecordType(RD))));
12105
12106 // Do the redeclaration lookup in the current scope.
12107 LookupResult Previous(*this, UsingName, LookupUsingDeclName,
12108 ForVisibleRedeclaration);
12109 Previous.setHideTags(false);
12110 if (S) {
12111 LookupName(Previous, S);
12112
12113 FilterUsingLookup(S, Previous);
12114 } else {
12115 assert(IsInstantiation && "no scope in non-instantiation")((void)0);
12116 if (CurContext->isRecord())
12117 LookupQualifiedName(Previous, CurContext);
12118 else {
12119 // No redeclaration check is needed here; in non-member contexts we
12120 // diagnosed all possible conflicts with other using-declarations when
12121 // building the template:
12122 //
12123 // For a dependent non-type using declaration, the only valid case is
12124 // if we instantiate to a single enumerator. We check for conflicts
12125 // between shadow declarations we introduce, and we check in the template
12126 // definition for conflicts between a non-type using declaration and any
12127 // other declaration, which together covers all cases.
12128 //
12129 // A dependent typename using declaration will never successfully
12130 // instantiate, since it will always name a class member, so we reject
12131 // that in the template definition.
12132 }
12133 }
12134
12135 // Check for invalid redeclarations.
12136 if (CheckUsingDeclRedeclaration(UsingLoc, HasTypenameKeyword,
12137 SS, IdentLoc, Previous))
12138 return nullptr;
12139
12140 // 'using_if_exists' doesn't make sense on an inherited constructor.
12141 if (IsUsingIfExists && UsingName.getName().getNameKind() ==
12142 DeclarationName::CXXConstructorName) {
12143 Diag(UsingLoc, diag::err_using_if_exists_on_ctor);
12144 return nullptr;
12145 }
12146
12147 DeclContext *LookupContext = computeDeclContext(SS);
12148 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
12149 if (!LookupContext || EllipsisLoc.isValid()) {
12150 NamedDecl *D;
12151 // Dependent scope, or an unexpanded pack
12152 if (!LookupContext && CheckUsingDeclQualifier(UsingLoc, HasTypenameKeyword,
12153 SS, NameInfo, IdentLoc))
12154 return nullptr;
12155
12156 if (HasTypenameKeyword) {
12157 // FIXME: not all declaration name kinds are legal here
12158 D = UnresolvedUsingTypenameDecl::Create(Context, CurContext,
12159 UsingLoc, TypenameLoc,
12160 QualifierLoc,
12161 IdentLoc, NameInfo.getName(),
12162 EllipsisLoc);
12163 } else {
12164 D = UnresolvedUsingValueDecl::Create(Context, CurContext, UsingLoc,
12165 QualifierLoc, NameInfo, EllipsisLoc);
12166 }
12167 D->setAccess(AS);
12168 CurContext->addDecl(D);
12169 ProcessDeclAttributeList(S, D, AttrList);
12170 return D;
12171 }
12172
12173 auto Build = [&](bool Invalid) {
12174 UsingDecl *UD =
12175 UsingDecl::Create(Context, CurContext, UsingLoc, QualifierLoc,
12176 UsingName, HasTypenameKeyword);
12177 UD->setAccess(AS);
12178 CurContext->addDecl(UD);
12179 ProcessDeclAttributeList(S, UD, AttrList);
12180 UD->setInvalidDecl(Invalid);
12181 return UD;
12182 };
12183 auto BuildInvalid = [&]{ return Build(true); };
12184 auto BuildValid = [&]{ return Build(false); };
12185
12186 if (RequireCompleteDeclContext(SS, LookupContext))
12187 return BuildInvalid();
12188
12189 // Look up the target name.
12190 LookupResult R(*this, NameInfo, LookupOrdinaryName);
12191
12192 // Unlike most lookups, we don't always want to hide tag
12193 // declarations: tag names are visible through the using declaration
12194 // even if hidden by ordinary names, *except* in a dependent context
12195 // where it's important for the sanity of two-phase lookup.
12196 if (!IsInstantiation)
12197 R.setHideTags(false);
12198
12199 // For the purposes of this lookup, we have a base object type
12200 // equal to that of the current context.
12201 if (CurContext->isRecord()) {
12202 R.setBaseObjectType(
12203 Context.getTypeDeclType(cast<CXXRecordDecl>(CurContext)));
12204 }
12205
12206 LookupQualifiedName(R, LookupContext);
12207
12208 // Validate the context, now we have a lookup
12209 if (CheckUsingDeclQualifier(UsingLoc, HasTypenameKeyword, SS, NameInfo,
12210 IdentLoc, &R))
12211 return nullptr;
12212
12213 if (R.empty() && IsUsingIfExists)
12214 R.addDecl(UnresolvedUsingIfExistsDecl::Create(Context, CurContext, UsingLoc,
12215 UsingName.getName()),
12216 AS_public);
12217
12218 // Try to correct typos if possible. If constructor name lookup finds no
12219 // results, that means the named class has no explicit constructors, and we
12220 // suppressed declaring implicit ones (probably because it's dependent or
12221 // invalid).
12222 if (R.empty() &&
12223 NameInfo.getName().getNameKind() != DeclarationName::CXXConstructorName) {
12224 // HACK 2017-01-08: Work around an issue with libstdc++'s detection of
12225 // ::gets. Sometimes it believes that glibc provides a ::gets in cases where
12226 // it does not. The issue was fixed in libstdc++ 6.3 (2016-12-21) and later.
12227 auto *II = NameInfo.getName().getAsIdentifierInfo();
12228 if (getLangOpts().CPlusPlus14 && II && II->isStr("gets") &&
12229 CurContext->isStdNamespace() &&
12230 isa<TranslationUnitDecl>(LookupContext) &&
12231 getSourceManager().isInSystemHeader(UsingLoc))
12232 return nullptr;
12233 UsingValidatorCCC CCC(HasTypenameKeyword, IsInstantiation, SS.getScopeRep(),
12234 dyn_cast<CXXRecordDecl>(CurContext));
12235 if (TypoCorrection Corrected =
12236 CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS, CCC,
12237 CTK_ErrorRecovery)) {
12238 // We reject candidates where DroppedSpecifier == true, hence the
12239 // literal '0' below.
12240 diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest)
12241 << NameInfo.getName() << LookupContext << 0
12242 << SS.getRange());
12243
12244 // If we picked a correction with no attached Decl we can't do anything
12245 // useful with it, bail out.
12246 NamedDecl *ND = Corrected.getCorrectionDecl();
12247 if (!ND)
12248 return BuildInvalid();
12249
12250 // If we corrected to an inheriting constructor, handle it as one.
12251 auto *RD = dyn_cast<CXXRecordDecl>(ND);
12252 if (RD && RD->isInjectedClassName()) {
12253 // The parent of the injected class name is the class itself.
12254 RD = cast<CXXRecordDecl>(RD->getParent());
12255
12256 // Fix up the information we'll use to build the using declaration.
12257 if (Corrected.WillReplaceSpecifier()) {
12258 NestedNameSpecifierLocBuilder Builder;
12259 Builder.MakeTrivial(Context, Corrected.getCorrectionSpecifier(),
12260 QualifierLoc.getSourceRange());
12261 QualifierLoc = Builder.getWithLocInContext(Context);
12262 }
12263
12264 // In this case, the name we introduce is the name of a derived class
12265 // constructor.
12266 auto *CurClass = cast<CXXRecordDecl>(CurContext);
12267 UsingName.setName(Context.DeclarationNames.getCXXConstructorName(
12268 Context.getCanonicalType(Context.getRecordType(CurClass))));
12269 UsingName.setNamedTypeInfo(nullptr);
12270 for (auto *Ctor : LookupConstructors(RD))
12271 R.addDecl(Ctor);
12272 R.resolveKind();
12273 } else {
12274 // FIXME: Pick up all the declarations if we found an overloaded
12275 // function.
12276 UsingName.setName(ND->getDeclName());
12277 R.addDecl(ND);
12278 }
12279 } else {
12280 Diag(IdentLoc, diag::err_no_member)
12281 << NameInfo.getName() << LookupContext << SS.getRange();
12282 return BuildInvalid();
12283 }
12284 }
12285
12286 if (R.isAmbiguous())
12287 return BuildInvalid();
12288
12289 if (HasTypenameKeyword) {
12290 // If we asked for a typename and got a non-type decl, error out.
12291 if (!R.getAsSingle<TypeDecl>() &&
12292 !R.getAsSingle<UnresolvedUsingIfExistsDecl>()) {
12293 Diag(IdentLoc, diag::err_using_typename_non_type);
12294 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
12295 Diag((*I)->getUnderlyingDecl()->getLocation(),
12296 diag::note_using_decl_target);
12297 return BuildInvalid();
12298 }
12299 } else {
12300 // If we asked for a non-typename and we got a type, error out,
12301 // but only if this is an instantiation of an unresolved using
12302 // decl. Otherwise just silently find the type name.
12303 if (IsInstantiation && R.getAsSingle<TypeDecl>()) {
12304 Diag(IdentLoc, diag::err_using_dependent_value_is_type);
12305 Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target);
12306 return BuildInvalid();
12307 }
12308 }
12309
12310 // C++14 [namespace.udecl]p6:
12311 // A using-declaration shall not name a namespace.
12312 if (R.getAsSingle<NamespaceDecl>()) {
12313 Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace)
12314 << SS.getRange();
12315 return BuildInvalid();
12316 }
12317
12318 UsingDecl *UD = BuildValid();
12319
12320 // Some additional rules apply to inheriting constructors.
12321 if (UsingName.getName().getNameKind() ==
12322 DeclarationName::CXXConstructorName) {
12323 // Suppress access diagnostics; the access check is instead performed at the
12324 // point of use for an inheriting constructor.
12325 R.suppressDiagnostics();
12326 if (CheckInheritingConstructorUsingDecl(UD))
12327 return UD;
12328 }
12329
12330 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
12331 UsingShadowDecl *PrevDecl = nullptr;
12332 if (!CheckUsingShadowDecl(UD, *I, Previous, PrevDecl))
12333 BuildUsingShadowDecl(S, UD, *I, PrevDecl);
12334 }
12335
12336 return UD;
12337}
12338
12339NamedDecl *Sema::BuildUsingEnumDeclaration(Scope *S, AccessSpecifier AS,
12340 SourceLocation UsingLoc,
12341 SourceLocation EnumLoc,
12342 SourceLocation NameLoc,
12343 EnumDecl *ED) {
12344 bool Invalid = false;
12345
12346 if (CurContext->getRedeclContext()->isRecord()) {
12347 /// In class scope, check if this is a duplicate, for better a diagnostic.
12348 DeclarationNameInfo UsingEnumName(ED->getDeclName(), NameLoc);
12349 LookupResult Previous(*this, UsingEnumName, LookupUsingDeclName,
12350 ForVisibleRedeclaration);
12351
12352 LookupName(Previous, S);
12353
12354 for (NamedDecl *D : Previous)
12355 if (UsingEnumDecl *UED = dyn_cast<UsingEnumDecl>(D))
12356 if (UED->getEnumDecl() == ED) {
12357 Diag(UsingLoc, diag::err_using_enum_decl_redeclaration)
12358 << SourceRange(EnumLoc, NameLoc);
12359 Diag(D->getLocation(), diag::note_using_enum_decl) << 1;
12360 Invalid = true;
12361 break;
12362 }
12363 }
12364
12365 if (RequireCompleteEnumDecl(ED, NameLoc))
12366 Invalid = true;
12367
12368 UsingEnumDecl *UD = UsingEnumDecl::Create(Context, CurContext, UsingLoc,
12369 EnumLoc, NameLoc, ED);
12370 UD->setAccess(AS);
12371 CurContext->addDecl(UD);
12372
12373 if (Invalid) {
12374 UD->setInvalidDecl();
12375 return UD;
12376 }
12377
12378 // Create the shadow decls for each enumerator
12379 for (EnumConstantDecl *EC : ED->enumerators()) {
12380 UsingShadowDecl *PrevDecl = nullptr;
12381 DeclarationNameInfo DNI(EC->getDeclName(), EC->getLocation());
12382 LookupResult Previous(*this, DNI, LookupOrdinaryName,
12383 ForVisibleRedeclaration);
12384 LookupName(Previous, S);
12385 FilterUsingLookup(S, Previous);
12386
12387 if (!CheckUsingShadowDecl(UD, EC, Previous, PrevDecl))
12388 BuildUsingShadowDecl(S, UD, EC, PrevDecl);
12389 }
12390
12391 return UD;
12392}
12393
12394NamedDecl *Sema::BuildUsingPackDecl(NamedDecl *InstantiatedFrom,
12395 ArrayRef<NamedDecl *> Expansions) {
12396 assert(isa<UnresolvedUsingValueDecl>(InstantiatedFrom) ||((void)0)
12397 isa<UnresolvedUsingTypenameDecl>(InstantiatedFrom) ||((void)0)
12398 isa<UsingPackDecl>(InstantiatedFrom))((void)0);
12399
12400 auto *UPD =
12401 UsingPackDecl::Create(Context, CurContext, InstantiatedFrom, Expansions);
12402 UPD->setAccess(InstantiatedFrom->getAccess());
12403 CurContext->addDecl(UPD);
12404 return UPD;
12405}
12406
12407/// Additional checks for a using declaration referring to a constructor name.
12408bool Sema::CheckInheritingConstructorUsingDecl(UsingDecl *UD) {
12409 assert(!UD->hasTypename() && "expecting a constructor name")((void)0);
12410
12411 const Type *SourceType = UD->getQualifier()->getAsType();
12412 assert(SourceType &&((void)0)
12413 "Using decl naming constructor doesn't have type in scope spec.")((void)0);
12414 CXXRecordDecl *TargetClass = cast<CXXRecordDecl>(CurContext);
12415
12416 // Check whether the named type is a direct base class.
12417 bool AnyDependentBases = false;
12418 auto *Base = findDirectBaseWithType(TargetClass, QualType(SourceType, 0),
12419 AnyDependentBases);
12420 if (!Base && !AnyDependentBases) {
12421 Diag(UD->getUsingLoc(),
12422 diag::err_using_decl_constructor_not_in_direct_base)
12423 << UD->getNameInfo().getSourceRange()
12424 << QualType(SourceType, 0) << TargetClass;
12425 UD->setInvalidDecl();
12426 return true;
12427 }
12428
12429 if (Base)
12430 Base->setInheritConstructors();
12431
12432 return false;
12433}
12434
12435/// Checks that the given using declaration is not an invalid
12436/// redeclaration. Note that this is checking only for the using decl
12437/// itself, not for any ill-formedness among the UsingShadowDecls.
12438bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
12439 bool HasTypenameKeyword,
12440 const CXXScopeSpec &SS,
12441 SourceLocation NameLoc,
12442 const LookupResult &Prev) {
12443 NestedNameSpecifier *Qual = SS.getScopeRep();
12444
12445 // C++03 [namespace.udecl]p8:
12446 // C++0x [namespace.udecl]p10:
12447 // A using-declaration is a declaration and can therefore be used
12448 // repeatedly where (and only where) multiple declarations are
12449 // allowed.
12450 //
12451 // That's in non-member contexts.
12452 if (!CurContext->getRedeclContext()->isRecord()) {
12453 // A dependent qualifier outside a class can only ever resolve to an
12454 // enumeration type. Therefore it conflicts with any other non-type
12455 // declaration in the same scope.
12456 // FIXME: How should we check for dependent type-type conflicts at block
12457 // scope?
12458 if (Qual->isDependent() && !HasTypenameKeyword) {
12459 for (auto *D : Prev) {
12460 if (!isa<TypeDecl>(D) && !isa<UsingDecl>(D) && !isa<UsingPackDecl>(D)) {
12461 bool OldCouldBeEnumerator =
12462 isa<UnresolvedUsingValueDecl>(D) || isa<EnumConstantDecl>(D);
12463 Diag(NameLoc,
12464 OldCouldBeEnumerator ? diag::err_redefinition
12465 : diag::err_redefinition_different_kind)
12466 << Prev.getLookupName();
12467 Diag(D->getLocation(), diag::note_previous_definition);
12468 return true;
12469 }
12470 }
12471 }
12472 return false;
12473 }
12474
12475 const NestedNameSpecifier *CNNS =
12476 Context.getCanonicalNestedNameSpecifier(Qual);
12477 for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) {
12478 NamedDecl *D = *I;
12479
12480 bool DTypename;
12481 NestedNameSpecifier *DQual;
12482 if (UsingDecl *UD = dyn_cast<UsingDecl>(D)) {
12483 DTypename = UD->hasTypename();
12484 DQual = UD->getQualifier();
12485 } else if (UnresolvedUsingValueDecl *UD
12486 = dyn_cast<UnresolvedUsingValueDecl>(D)) {
12487 DTypename = false;
12488 DQual = UD->getQualifier();
12489 } else if (UnresolvedUsingTypenameDecl *UD
12490 = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
12491 DTypename = true;
12492 DQual = UD->getQualifier();
12493 } else continue;
12494
12495 // using decls differ if one says 'typename' and the other doesn't.
12496 // FIXME: non-dependent using decls?
12497 if (HasTypenameKeyword != DTypename) continue;
12498
12499 // using decls differ if they name different scopes (but note that
12500 // template instantiation can cause this check to trigger when it
12501 // didn't before instantiation).
12502 if (CNNS != Context.getCanonicalNestedNameSpecifier(DQual))
12503 continue;
12504
12505 Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange();
12506 Diag(D->getLocation(), diag::note_using_decl) << 1;
12507 return true;
12508 }
12509
12510 return false;
12511}
12512
12513/// Checks that the given nested-name qualifier used in a using decl
12514/// in the current context is appropriately related to the current
12515/// scope. If an error is found, diagnoses it and returns true.
12516/// R is nullptr, if the caller has not (yet) done a lookup, otherwise it's the
12517/// result of that lookup. UD is likewise nullptr, except when we have an
12518/// already-populated UsingDecl whose shadow decls contain the same information
12519/// (i.e. we're instantiating a UsingDecl with non-dependent scope).
12520bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc, bool HasTypename,
12521 const CXXScopeSpec &SS,
12522 const DeclarationNameInfo &NameInfo,
12523 SourceLocation NameLoc,
12524 const LookupResult *R, const UsingDecl *UD) {
12525 DeclContext *NamedContext = computeDeclContext(SS);
12526 assert(bool(NamedContext) == (R || UD) && !(R && UD) &&((void)0)
12527 "resolvable context must have exactly one set of decls")((void)0);
12528
12529 // C++ 20 permits using an enumerator that does not have a class-hierarchy
12530 // relationship.
12531 bool Cxx20Enumerator = false;
12532 if (NamedContext) {
12533 EnumConstantDecl *EC = nullptr;
12534 if (R)
12535 EC = R->getAsSingle<EnumConstantDecl>();
12536 else if (UD && UD->shadow_size() == 1)
12537 EC = dyn_cast<EnumConstantDecl>(UD->shadow_begin()->getTargetDecl());
12538 if (EC)
12539 Cxx20Enumerator = getLangOpts().CPlusPlus20;
12540
12541 if (auto *ED = dyn_cast<EnumDecl>(NamedContext)) {
12542 // C++14 [namespace.udecl]p7:
12543 // A using-declaration shall not name a scoped enumerator.
12544 // C++20 p1099 permits enumerators.
12545 if (EC && R && ED->isScoped())
12546 Diag(SS.getBeginLoc(),
12547 getLangOpts().CPlusPlus20
12548 ? diag::warn_cxx17_compat_using_decl_scoped_enumerator
12549 : diag::ext_using_decl_scoped_enumerator)
12550 << SS.getRange();
12551
12552 // We want to consider the scope of the enumerator
12553 NamedContext = ED->getDeclContext();
12554 }
12555 }
12556
12557 if (!CurContext->isRecord()) {
12558 // C++03 [namespace.udecl]p3:
12559 // C++0x [namespace.udecl]p8:
12560 // A using-declaration for a class member shall be a member-declaration.
12561 // C++20 [namespace.udecl]p7
12562 // ... other than an enumerator ...
12563
12564 // If we weren't able to compute a valid scope, it might validly be a
12565 // dependent class or enumeration scope. If we have a 'typename' keyword,
12566 // the scope must resolve to a class type.
12567 if (NamedContext ? !NamedContext->getRedeclContext()->isRecord()
12568 : !HasTypename)
12569 return false; // OK
12570
12571 Diag(NameLoc,
12572 Cxx20Enumerator
12573 ? diag::warn_cxx17_compat_using_decl_class_member_enumerator
12574 : diag::err_using_decl_can_not_refer_to_class_member)
12575 << SS.getRange();
12576
12577 if (Cxx20Enumerator)
12578 return false; // OK
12579
12580 auto *RD = NamedContext
12581 ? cast<CXXRecordDecl>(NamedContext->getRedeclContext())
12582 : nullptr;
12583 if (RD && !RequireCompleteDeclContext(const_cast<CXXScopeSpec &>(SS), RD)) {
12584 // See if there's a helpful fixit
12585
12586 if (!R) {
12587 // We will have already diagnosed the problem on the template
12588 // definition, Maybe we should do so again?
12589 } else if (R->getAsSingle<TypeDecl>()) {
12590 if (getLangOpts().CPlusPlus11) {
12591 // Convert 'using X::Y;' to 'using Y = X::Y;'.
12592 Diag(SS.getBeginLoc(), diag::note_using_decl_class_member_workaround)
12593 << 0 // alias declaration
12594 << FixItHint::CreateInsertion(SS.getBeginLoc(),
12595 NameInfo.getName().getAsString() +
12596 " = ");
12597 } else {
12598 // Convert 'using X::Y;' to 'typedef X::Y Y;'.
12599 SourceLocation InsertLoc = getLocForEndOfToken(NameInfo.getEndLoc());
12600 Diag(InsertLoc, diag::note_using_decl_class_member_workaround)
12601 << 1 // typedef declaration
12602 << FixItHint::CreateReplacement(UsingLoc, "typedef")
12603 << FixItHint::CreateInsertion(
12604 InsertLoc, " " + NameInfo.getName().getAsString());
12605 }
12606 } else if (R->getAsSingle<VarDecl>()) {
12607 // Don't provide a fixit outside C++11 mode; we don't want to suggest
12608 // repeating the type of the static data member here.
12609 FixItHint FixIt;
12610 if (getLangOpts().CPlusPlus11) {
12611 // Convert 'using X::Y;' to 'auto &Y = X::Y;'.
12612 FixIt = FixItHint::CreateReplacement(
12613 UsingLoc, "auto &" + NameInfo.getName().getAsString() + " = ");
12614 }
12615
12616 Diag(UsingLoc, diag::note_using_decl_class_member_workaround)
12617 << 2 // reference declaration
12618 << FixIt;
12619 } else if (R->getAsSingle<EnumConstantDecl>()) {
12620 // Don't provide a fixit outside C++11 mode; we don't want to suggest
12621 // repeating the type of the enumeration here, and we can't do so if
12622 // the type is anonymous.
12623 FixItHint FixIt;
12624 if (getLangOpts().CPlusPlus11) {
12625 // Convert 'using X::Y;' to 'auto &Y = X::Y;'.
12626 FixIt = FixItHint::CreateReplacement(
12627 UsingLoc,
12628 "constexpr auto " + NameInfo.getName().getAsString() + " = ");
12629 }
12630
12631 Diag(UsingLoc, diag::note_using_decl_class_member_workaround)
12632 << (getLangOpts().CPlusPlus11 ? 4 : 3) // const[expr] variable
12633 << FixIt;
12634 }
12635 }
12636
12637 return true; // Fail
12638 }
12639
12640 // If the named context is dependent, we can't decide much.
12641 if (!NamedContext) {
12642 // FIXME: in C++0x, we can diagnose if we can prove that the
12643 // nested-name-specifier does not refer to a base class, which is
12644 // still possible in some cases.
12645
12646 // Otherwise we have to conservatively report that things might be
12647 // okay.
12648 return false;
12649 }
12650
12651 // The current scope is a record.
12652 if (!NamedContext->isRecord()) {
12653 // Ideally this would point at the last name in the specifier,
12654 // but we don't have that level of source info.
12655 Diag(SS.getBeginLoc(),
12656 Cxx20Enumerator
12657 ? diag::warn_cxx17_compat_using_decl_non_member_enumerator
12658 : diag::err_using_decl_nested_name_specifier_is_not_class)
12659 << SS.getScopeRep() << SS.getRange();
12660
12661 if (Cxx20Enumerator)
12662 return false; // OK
12663
12664 return true;
12665 }
12666
12667 if (!NamedContext->isDependentContext() &&
12668 RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), NamedContext))
12669 return true;
12670
12671 if (getLangOpts().CPlusPlus11) {
12672 // C++11 [namespace.udecl]p3:
12673 // In a using-declaration used as a member-declaration, the
12674 // nested-name-specifier shall name a base class of the class
12675 // being defined.
12676
12677 if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(
12678 cast<CXXRecordDecl>(NamedContext))) {
12679
12680 if (Cxx20Enumerator) {
12681 Diag(NameLoc, diag::warn_cxx17_compat_using_decl_non_member_enumerator)
12682 << SS.getRange();
12683 return false;
12684 }
12685
12686 if (CurContext == NamedContext) {
12687 Diag(SS.getBeginLoc(),
12688 diag::err_using_decl_nested_name_specifier_is_current_class)
12689 << SS.getRange();
12690 return !getLangOpts().CPlusPlus20;
12691 }
12692
12693 if (!cast<CXXRecordDecl>(NamedContext)->isInvalidDecl()) {
12694 Diag(SS.getBeginLoc(),
12695 diag::err_using_decl_nested_name_specifier_is_not_base_class)
12696 << SS.getScopeRep() << cast<CXXRecordDecl>(CurContext)
12697 << SS.getRange();
12698 }
12699 return true;
12700 }
12701
12702 return false;
12703 }
12704
12705 // C++03 [namespace.udecl]p4:
12706 // A using-declaration used as a member-declaration shall refer
12707 // to a member of a base class of the class being defined [etc.].
12708
12709 // Salient point: SS doesn't have to name a base class as long as
12710 // lookup only finds members from base classes. Therefore we can
12711 // diagnose here only if we can prove that that can't happen,
12712 // i.e. if the class hierarchies provably don't intersect.
12713
12714 // TODO: it would be nice if "definitely valid" results were cached
12715 // in the UsingDecl and UsingShadowDecl so that these checks didn't
12716 // need to be repeated.
12717
12718 llvm::SmallPtrSet<const CXXRecordDecl *, 4> Bases;
12719 auto Collect = [&Bases](const CXXRecordDecl *Base) {
12720 Bases.insert(Base);
12721 return true;
12722 };
12723
12724 // Collect all bases. Return false if we find a dependent base.
12725 if (!cast<CXXRecordDecl>(CurContext)->forallBases(Collect))
12726 return false;
12727
12728 // Returns true if the base is dependent or is one of the accumulated base
12729 // classes.
12730 auto IsNotBase = [&Bases](const CXXRecordDecl *Base) {
12731 return !Bases.count(Base);
12732 };
12733
12734 // Return false if the class has a dependent base or if it or one
12735 // of its bases is present in the base set of the current context.
12736 if (Bases.count(cast<CXXRecordDecl>(NamedContext)) ||
12737 !cast<CXXRecordDecl>(NamedContext)->forallBases(IsNotBase))
12738 return false;
12739
12740 Diag(SS.getRange().getBegin(),
12741 diag::err_using_decl_nested_name_specifier_is_not_base_class)
12742 << SS.getScopeRep()
12743 << cast<CXXRecordDecl>(CurContext)
12744 << SS.getRange();
12745
12746 return true;
12747}
12748
12749Decl *Sema::ActOnAliasDeclaration(Scope *S, AccessSpecifier AS,
12750 MultiTemplateParamsArg TemplateParamLists,
12751 SourceLocation UsingLoc, UnqualifiedId &Name,
12752 const ParsedAttributesView &AttrList,
12753 TypeResult Type, Decl *DeclFromDeclSpec) {
12754 // Skip up to the relevant declaration scope.
12755 while (S->isTemplateParamScope())
12756 S = S->getParent();
12757 assert((S->getFlags() & Scope::DeclScope) &&((void)0)
12758 "got alias-declaration outside of declaration scope")((void)0);
12759
12760 if (Type.isInvalid())
12761 return nullptr;
12762
12763 bool Invalid = false;
12764 DeclarationNameInfo NameInfo = GetNameFromUnqualifiedId(Name);
12765 TypeSourceInfo *TInfo = nullptr;
12766 GetTypeFromParser(Type.get(), &TInfo);
12767
12768 if (DiagnoseClassNameShadow(CurContext, NameInfo))
12769 return nullptr;
12770
12771 if (DiagnoseUnexpandedParameterPack(Name.StartLocation, TInfo,
12772 UPPC_DeclarationType)) {
12773 Invalid = true;
12774 TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
12775 TInfo->getTypeLoc().getBeginLoc());
12776 }
12777
12778 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
12779 TemplateParamLists.size()
12780 ? forRedeclarationInCurContext()
12781 : ForVisibleRedeclaration);
12782 LookupName(Previous, S);
12783
12784 // Warn about shadowing the name of a template parameter.
12785 if (Previous.isSingleResult() &&
12786 Previous.getFoundDecl()->isTemplateParameter()) {
12787 DiagnoseTemplateParameterShadow(Name.StartLocation,Previous.getFoundDecl());
12788 Previous.clear();
12789 }
12790
12791 assert(Name.Kind == UnqualifiedIdKind::IK_Identifier &&((void)0)
12792 "name in alias declaration must be an identifier")((void)0);
12793 TypeAliasDecl *NewTD = TypeAliasDecl::Create(Context, CurContext, UsingLoc,
12794 Name.StartLocation,
12795 Name.Identifier, TInfo);
12796
12797 NewTD->setAccess(AS);
12798
12799 if (Invalid)
12800 NewTD->setInvalidDecl();
12801
12802 ProcessDeclAttributeList(S, NewTD, AttrList);
12803 AddPragmaAttributes(S, NewTD);
12804
12805 CheckTypedefForVariablyModifiedType(S, NewTD);
12806 Invalid |= NewTD->isInvalidDecl();
12807
12808 bool Redeclaration = false;
12809
12810 NamedDecl *NewND;
12811 if (TemplateParamLists.size()) {
12812 TypeAliasTemplateDecl *OldDecl = nullptr;
12813 TemplateParameterList *OldTemplateParams = nullptr;
12814
12815 if (TemplateParamLists.size() != 1) {
12816 Diag(UsingLoc, diag::err_alias_template_extra_headers)
12817 << SourceRange(TemplateParamLists[1]->getTemplateLoc(),
12818 TemplateParamLists[TemplateParamLists.size()-1]->getRAngleLoc());
12819 }
12820 TemplateParameterList *TemplateParams = TemplateParamLists[0];
12821
12822 // Check that we can declare a template here.
12823 if (CheckTemplateDeclScope(S, TemplateParams))
12824 return nullptr;
12825
12826 // Only consider previous declarations in the same scope.
12827 FilterLookupForScope(Previous, CurContext, S, /*ConsiderLinkage*/false,
12828 /*ExplicitInstantiationOrSpecialization*/false);
12829 if (!Previous.empty()) {
12830 Redeclaration = true;
12831
12832 OldDecl = Previous.getAsSingle<TypeAliasTemplateDecl>();
12833 if (!OldDecl && !Invalid) {
12834 Diag(UsingLoc, diag::err_redefinition_different_kind)
12835 << Name.Identifier;
12836
12837 NamedDecl *OldD = Previous.getRepresentativeDecl();
12838 if (OldD->getLocation().isValid())
12839 Diag(OldD->getLocation(), diag::note_previous_definition);
12840
12841 Invalid = true;
12842 }
12843
12844 if (!Invalid && OldDecl && !OldDecl->isInvalidDecl()) {
12845 if (TemplateParameterListsAreEqual(TemplateParams,
12846 OldDecl->getTemplateParameters(),
12847 /*Complain=*/true,
12848 TPL_TemplateMatch))
12849 OldTemplateParams =
12850 OldDecl->getMostRecentDecl()->getTemplateParameters();
12851 else
12852 Invalid = true;
12853
12854 TypeAliasDecl *OldTD = OldDecl->getTemplatedDecl();
12855 if (!Invalid &&
12856 !Context.hasSameType(OldTD->getUnderlyingType(),
12857 NewTD->getUnderlyingType())) {
12858 // FIXME: The C++0x standard does not clearly say this is ill-formed,
12859 // but we can't reasonably accept it.
12860 Diag(NewTD->getLocation(), diag::err_redefinition_different_typedef)
12861 << 2 << NewTD->getUnderlyingType() << OldTD->getUnderlyingType();
12862 if (OldTD->getLocation().isValid())
12863 Diag(OldTD->getLocation(), diag::note_previous_definition);
12864 Invalid = true;
12865 }
12866 }
12867 }
12868
12869 // Merge any previous default template arguments into our parameters,
12870 // and check the parameter list.
12871 if (CheckTemplateParameterList(TemplateParams, OldTemplateParams,
12872 TPC_TypeAliasTemplate))
12873 return nullptr;
12874
12875 TypeAliasTemplateDecl *NewDecl =
12876 TypeAliasTemplateDecl::Create(Context, CurContext, UsingLoc,
12877 Name.Identifier, TemplateParams,
12878 NewTD);
12879 NewTD->setDescribedAliasTemplate(NewDecl);
12880
12881 NewDecl->setAccess(AS);
12882
12883 if (Invalid)
12884 NewDecl->setInvalidDecl();
12885 else if (OldDecl) {
12886 NewDecl->setPreviousDecl(OldDecl);
12887 CheckRedeclarationModuleOwnership(NewDecl, OldDecl);
12888 }
12889
12890 NewND = NewDecl;
12891 } else {
12892 if (auto *TD = dyn_cast_or_null<TagDecl>(DeclFromDeclSpec)) {
12893 setTagNameForLinkagePurposes(TD, NewTD);
12894 handleTagNumbering(TD, S);
12895 }
12896 ActOnTypedefNameDecl(S, CurContext, NewTD, Previous, Redeclaration);
12897 NewND = NewTD;
12898 }
12899
12900 PushOnScopeChains(NewND, S);
12901 ActOnDocumentableDecl(NewND);
12902 return NewND;
12903}
12904
12905Decl *Sema::ActOnNamespaceAliasDef(Scope *S, SourceLocation NamespaceLoc,
12906 SourceLocation AliasLoc,
12907 IdentifierInfo *Alias, CXXScopeSpec &SS,
12908 SourceLocation IdentLoc,
12909 IdentifierInfo *Ident) {
12910
12911 // Lookup the namespace name.
12912 LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName);
12913 LookupParsedName(R, S, &SS);
12914
12915 if (R.isAmbiguous())
12916 return nullptr;
12917
12918 if (R.empty()) {
12919 if (!TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, Ident)) {
12920 Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
12921 return nullptr;
12922 }
12923 }
12924 assert(!R.isAmbiguous() && !R.empty())((void)0);
12925 NamedDecl *ND = R.getRepresentativeDecl();
12926
12927 // Check if we have a previous declaration with the same name.
12928 LookupResult PrevR(*this, Alias, AliasLoc, LookupOrdinaryName,
12929 ForVisibleRedeclaration);
12930 LookupName(PrevR, S);
12931
12932 // Check we're not shadowing a template parameter.
12933 if (PrevR.isSingleResult() && PrevR.getFoundDecl()->isTemplateParameter()) {
12934 DiagnoseTemplateParameterShadow(AliasLoc, PrevR.getFoundDecl());
12935 PrevR.clear();
12936 }
12937
12938 // Filter out any other lookup result from an enclosing scope.
12939 FilterLookupForScope(PrevR, CurContext, S, /*ConsiderLinkage*/false,
12940 /*AllowInlineNamespace*/false);
12941
12942 // Find the previous declaration and check that we can redeclare it.
12943 NamespaceAliasDecl *Prev = nullptr;
12944 if (PrevR.isSingleResult()) {
12945 NamedDecl *PrevDecl = PrevR.getRepresentativeDecl();
12946 if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
12947 // We already have an alias with the same name that points to the same
12948 // namespace; check that it matches.
12949 if (AD->getNamespace()->Equals(getNamespaceDecl(ND))) {
12950 Prev = AD;
12951 } else if (isVisible(PrevDecl)) {
12952 Diag(AliasLoc, diag::err_redefinition_different_namespace_alias)
12953 << Alias;
12954 Diag(AD->getLocation(), diag::note_previous_namespace_alias)
12955 << AD->getNamespace();
12956 return nullptr;
12957 }
12958 } else if (isVisible(PrevDecl)) {
12959 unsigned DiagID = isa<NamespaceDecl>(PrevDecl->getUnderlyingDecl())
12960 ? diag::err_redefinition
12961 : diag::err_redefinition_different_kind;
12962 Diag(AliasLoc, DiagID) << Alias;
12963 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
12964 return nullptr;
12965 }
12966 }
12967
12968 // The use of a nested name specifier may trigger deprecation warnings.
12969 DiagnoseUseOfDecl(ND, IdentLoc);
12970
12971 NamespaceAliasDecl *AliasDecl =
12972 NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc,
12973 Alias, SS.getWithLocInContext(Context),
12974 IdentLoc, ND);
12975 if (Prev)
12976 AliasDecl->setPreviousDecl(Prev);
12977
12978 PushOnScopeChains(AliasDecl, S);
12979 return AliasDecl;
12980}
12981
12982namespace {
12983struct SpecialMemberExceptionSpecInfo
12984 : SpecialMemberVisitor<SpecialMemberExceptionSpecInfo> {
12985 SourceLocation Loc;
12986 Sema::ImplicitExceptionSpecification ExceptSpec;
12987
12988 SpecialMemberExceptionSpecInfo(Sema &S, CXXMethodDecl *MD,
12989 Sema::CXXSpecialMember CSM,
12990 Sema::InheritedConstructorInfo *ICI,
12991 SourceLocation Loc)
12992 : SpecialMemberVisitor(S, MD, CSM, ICI), Loc(Loc), ExceptSpec(S) {}
12993
12994 bool visitBase(CXXBaseSpecifier *Base);
12995 bool visitField(FieldDecl *FD);
12996
12997 void visitClassSubobject(CXXRecordDecl *Class, Subobject Subobj,
12998 unsigned Quals);
12999
13000 void visitSubobjectCall(Subobject Subobj,
13001 Sema::SpecialMemberOverloadResult SMOR);
13002};
13003}
13004
13005bool SpecialMemberExceptionSpecInfo::visitBase(CXXBaseSpecifier *Base) {
13006 auto *RT = Base->getType()->getAs<RecordType>();
13007 if (!RT)
13008 return false;
13009
13010 auto *BaseClass = cast<CXXRecordDecl>(RT->getDecl());
13011 Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass);
13012 if (auto *BaseCtor = SMOR.getMethod()) {
13013 visitSubobjectCall(Base, BaseCtor);
13014 return false;
13015 }
13016
13017 visitClassSubobject(BaseClass, Base, 0);
13018 return false;
13019}
13020
13021bool SpecialMemberExceptionSpecInfo::visitField(FieldDecl *FD) {
13022 if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer()) {
13023 Expr *E = FD->getInClassInitializer();
13024 if (!E)
13025 // FIXME: It's a little wasteful to build and throw away a
13026 // CXXDefaultInitExpr here.
13027 // FIXME: We should have a single context note pointing at Loc, and
13028 // this location should be MD->getLocation() instead, since that's
13029 // the location where we actually use the default init expression.
13030 E = S.BuildCXXDefaultInitExpr(Loc, FD).get();
13031 if (E)
13032 ExceptSpec.CalledExpr(E);
13033 } else if (auto *RT = S.Context.getBaseElementType(FD->getType())
13034 ->getAs<RecordType>()) {
13035 visitClassSubobject(cast<CXXRecordDecl>(RT->getDecl()), FD,
13036 FD->getType().getCVRQualifiers());
13037 }
13038 return false;
13039}
13040
13041void SpecialMemberExceptionSpecInfo::visitClassSubobject(CXXRecordDecl *Class,
13042 Subobject Subobj,
13043 unsigned Quals) {
13044 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
13045 bool IsMutable = Field && Field->isMutable();
13046 visitSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable));
13047}
13048
13049void SpecialMemberExceptionSpecInfo::visitSubobjectCall(
13050 Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR) {
13051 // Note, if lookup fails, it doesn't matter what exception specification we
13052 // choose because the special member will be deleted.
13053 if (CXXMethodDecl *MD = SMOR.getMethod())
13054 ExceptSpec.CalledDecl(getSubobjectLoc(Subobj), MD);
13055}
13056
13057bool Sema::tryResolveExplicitSpecifier(ExplicitSpecifier &ExplicitSpec) {
13058 llvm::APSInt Result;
13059 ExprResult Converted = CheckConvertedConstantExpression(
13060 ExplicitSpec.getExpr(), Context.BoolTy, Result, CCEK_ExplicitBool);
13061 ExplicitSpec.setExpr(Converted.get());
13062 if (Converted.isUsable() && !Converted.get()->isValueDependent()) {
13063 ExplicitSpec.setKind(Result.getBoolValue()
13064 ? ExplicitSpecKind::ResolvedTrue
13065 : ExplicitSpecKind::ResolvedFalse);
13066 return true;
13067 }
13068 ExplicitSpec.setKind(ExplicitSpecKind::Unresolved);
13069 return false;
13070}
13071
13072ExplicitSpecifier Sema::ActOnExplicitBoolSpecifier(Expr *ExplicitExpr) {
13073 ExplicitSpecifier ES(ExplicitExpr, ExplicitSpecKind::Unresolved);
13074 if (!ExplicitExpr->isTypeDependent())
13075 tryResolveExplicitSpecifier(ES);
13076 return ES;
13077}
13078
13079static Sema::ImplicitExceptionSpecification
13080ComputeDefaultedSpecialMemberExceptionSpec(
13081 Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
13082 Sema::InheritedConstructorInfo *ICI) {
13083 ComputingExceptionSpec CES(S, MD, Loc);
13084
13085 CXXRecordDecl *ClassDecl = MD->getParent();
13086
13087 // C++ [except.spec]p14:
13088 // An implicitly declared special member function (Clause 12) shall have an
13089 // exception-specification. [...]
13090 SpecialMemberExceptionSpecInfo Info(S, MD, CSM, ICI, MD->getLocation());
13091 if (ClassDecl->isInvalidDecl())
13092 return Info.ExceptSpec;
13093
13094 // FIXME: If this diagnostic fires, we're probably missing a check for
13095 // attempting to resolve an exception specification before it's known
13096 // at a higher level.
13097 if (S.RequireCompleteType(MD->getLocation(),
13098 S.Context.getRecordType(ClassDecl),
13099 diag::err_exception_spec_incomplete_type))
13100 return Info.ExceptSpec;
13101
13102 // C++1z [except.spec]p7:
13103 // [Look for exceptions thrown by] a constructor selected [...] to
13104 // initialize a potentially constructed subobject,
13105 // C++1z [except.spec]p8:
13106 // The exception specification for an implicitly-declared destructor, or a
13107 // destructor without a noexcept-specifier, is potentially-throwing if and
13108 // only if any of the destructors for any of its potentially constructed
13109 // subojects is potentially throwing.
13110 // FIXME: We respect the first rule but ignore the "potentially constructed"
13111 // in the second rule to resolve a core issue (no number yet) that would have
13112 // us reject:
13113 // struct A { virtual void f() = 0; virtual ~A() noexcept(false) = 0; };
13114 // struct B : A {};
13115 // struct C : B { void f(); };
13116 // ... due to giving B::~B() a non-throwing exception specification.
13117 Info.visit(Info.IsConstructor ? Info.VisitPotentiallyConstructedBases
13118 : Info.VisitAllBases);
13119
13120 return Info.ExceptSpec;
13121}
13122
13123namespace {
13124/// RAII object to register a special member as being currently declared.
13125struct DeclaringSpecialMember {
13126 Sema &S;
13127 Sema::SpecialMemberDecl D;
13128 Sema::ContextRAII SavedContext;
13129 bool WasAlreadyBeingDeclared;
13130
13131 DeclaringSpecialMember(Sema &S, CXXRecordDecl *RD, Sema::CXXSpecialMember CSM)
13132 : S(S), D(RD, CSM), SavedContext(S, RD) {
13133 WasAlreadyBeingDeclared = !S.SpecialMembersBeingDeclared.insert(D).second;
13134 if (WasAlreadyBeingDeclared)
13135 // This almost never happens, but if it does, ensure that our cache
13136 // doesn't contain a stale result.
13137 S.SpecialMemberCache.clear();
13138 else {
13139 // Register a note to be produced if we encounter an error while
13140 // declaring the special member.
13141 Sema::CodeSynthesisContext Ctx;
13142 Ctx.Kind = Sema::CodeSynthesisContext::DeclaringSpecialMember;
13143 // FIXME: We don't have a location to use here. Using the class's
13144 // location maintains the fiction that we declare all special members
13145 // with the class, but (1) it's not clear that lying about that helps our
13146 // users understand what's going on, and (2) there may be outer contexts
13147 // on the stack (some of which are relevant) and printing them exposes
13148 // our lies.
13149 Ctx.PointOfInstantiation = RD->getLocation();
13150 Ctx.Entity = RD;
13151 Ctx.SpecialMember = CSM;
13152 S.pushCodeSynthesisContext(Ctx);
13153 }
13154 }
13155 ~DeclaringSpecialMember() {
13156 if (!WasAlreadyBeingDeclared) {
13157 S.SpecialMembersBeingDeclared.erase(D);
13158 S.popCodeSynthesisContext();
13159 }
13160 }
13161
13162 /// Are we already trying to declare this special member?
13163 bool isAlreadyBeingDeclared() const {
13164 return WasAlreadyBeingDeclared;
13165 }
13166};
13167}
13168
13169void Sema::CheckImplicitSpecialMemberDeclaration(Scope *S, FunctionDecl *FD) {
13170 // Look up any existing declarations, but don't trigger declaration of all
13171 // implicit special members with this name.
13172 DeclarationName Name = FD->getDeclName();
13173 LookupResult R(*this, Name, SourceLocation(), LookupOrdinaryName,
13174 ForExternalRedeclaration);
13175 for (auto *D : FD->getParent()->lookup(Name))
13176 if (auto *Acceptable = R.getAcceptableDecl(D))
13177 R.addDecl(Acceptable);
13178 R.resolveKind();
13179 R.suppressDiagnostics();
13180
13181 CheckFunctionDeclaration(S, FD, R, /*IsMemberSpecialization*/false);
13182}
13183
13184void Sema::setupImplicitSpecialMemberType(CXXMethodDecl *SpecialMem,
13185 QualType ResultTy,
13186 ArrayRef<QualType> Args) {
13187 // Build an exception specification pointing back at this constructor.
13188 FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, SpecialMem);
13189
13190 LangAS AS = getDefaultCXXMethodAddrSpace();
13191 if (AS != LangAS::Default) {
13192 EPI.TypeQuals.addAddressSpace(AS);
13193 }
13194
13195 auto QT = Context.getFunctionType(ResultTy, Args, EPI);
13196 SpecialMem->setType(QT);
13197
13198 // During template instantiation of implicit special member functions we need
13199 // a reliable TypeSourceInfo for the function prototype in order to allow
13200 // functions to be substituted.
13201 if (inTemplateInstantiation() &&
13202 cast<CXXRecordDecl>(SpecialMem->getParent())->isLambda()) {
13203 TypeSourceInfo *TSI =
13204 Context.getTrivialTypeSourceInfo(SpecialMem->getType());
13205 SpecialMem->setTypeSourceInfo(TSI);
13206 }
13207}
13208
13209CXXConstructorDecl *Sema::DeclareImplicitDefaultConstructor(
13210 CXXRecordDecl *ClassDecl) {
13211 // C++ [class.ctor]p5:
13212 // A default constructor for a class X is a constructor of class X
13213 // that can be called without an argument. If there is no
13214 // user-declared constructor for class X, a default constructor is
13215 // implicitly declared. An implicitly-declared default constructor
13216 // is an inline public member of its class.
13217 assert(ClassDecl->needsImplicitDefaultConstructor() &&((void)0)
13218 "Should not build implicit default constructor!")((void)0);
13219
13220 DeclaringSpecialMember DSM(*this, ClassDecl, CXXDefaultConstructor);
13221 if (DSM.isAlreadyBeingDeclared())
13222 return nullptr;
13223
13224 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
13225 CXXDefaultConstructor,
13226 false);
13227
13228 // Create the actual constructor declaration.
13229 CanQualType ClassType
13230 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
13231 SourceLocation ClassLoc = ClassDecl->getLocation();
13232 DeclarationName Name
13233 = Context.DeclarationNames.getCXXConstructorName(ClassType);
13234 DeclarationNameInfo NameInfo(Name, ClassLoc);
13235 CXXConstructorDecl *DefaultCon = CXXConstructorDecl::Create(
13236 Context, ClassDecl, ClassLoc, NameInfo, /*Type*/ QualType(),
13237 /*TInfo=*/nullptr, ExplicitSpecifier(),
13238 /*isInline=*/true, /*isImplicitlyDeclared=*/true,
13239 Constexpr ? ConstexprSpecKind::Constexpr
13240 : ConstexprSpecKind::Unspecified);
13241 DefaultCon->setAccess(AS_public);
13242 DefaultCon->setDefaulted();
13243
13244 if (getLangOpts().CUDA) {
13245 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDefaultConstructor,
13246 DefaultCon,
13247 /* ConstRHS */ false,
13248 /* Diagnose */ false);
13249 }
13250
13251 setupImplicitSpecialMemberType(DefaultCon, Context.VoidTy, None);
13252
13253 // We don't need to use SpecialMemberIsTrivial here; triviality for default
13254 // constructors is easy to compute.
13255 DefaultCon->setTrivial(ClassDecl->hasTrivialDefaultConstructor());
13256
13257 // Note that we have declared this constructor.
13258 ++getASTContext().NumImplicitDefaultConstructorsDeclared;
13259
13260 Scope *S = getScopeForContext(ClassDecl);
13261 CheckImplicitSpecialMemberDeclaration(S, DefaultCon);
13262
13263 if (ShouldDeleteSpecialMember(DefaultCon, CXXDefaultConstructor))
13264 SetDeclDeleted(DefaultCon, ClassLoc);
13265
13266 if (S)
13267 PushOnScopeChains(DefaultCon, S, false);
13268 ClassDecl->addDecl(DefaultCon);
13269
13270 return DefaultCon;
13271}
13272
13273void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
13274 CXXConstructorDecl *Constructor) {
13275 assert((Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&((void)0)
13276 !Constructor->doesThisDeclarationHaveABody() &&((void)0)
13277 !Constructor->isDeleted()) &&((void)0)
13278 "DefineImplicitDefaultConstructor - call it for implicit default ctor")((void)0);
13279 if (Constructor->willHaveBody() || Constructor->isInvalidDecl())
13280 return;
13281
13282 CXXRecordDecl *ClassDecl = Constructor->getParent();
13283 assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor")((void)0);
13284
13285 SynthesizedFunctionScope Scope(*this, Constructor);
13286
13287 // The exception specification is needed because we are defining the
13288 // function.
13289 ResolveExceptionSpec(CurrentLocation,
13290 Constructor->getType()->castAs<FunctionProtoType>());
13291 MarkVTableUsed(CurrentLocation, ClassDecl);
13292
13293 // Add a context note for diagnostics produced after this point.
13294 Scope.addContextNote(CurrentLocation);
13295
13296 if (SetCtorInitializers(Constructor, /*AnyErrors=*/false)) {
13297 Constructor->setInvalidDecl();
13298 return;
13299 }
13300
13301 SourceLocation Loc = Constructor->getEndLoc().isValid()
13302 ? Constructor->getEndLoc()
13303 : Constructor->getLocation();
13304 Constructor->setBody(new (Context) CompoundStmt(Loc));
13305 Constructor->markUsed(Context);
13306
13307 if (ASTMutationListener *L = getASTMutationListener()) {
13308 L->CompletedImplicitDefinition(Constructor);
13309 }
13310
13311 DiagnoseUninitializedFields(*this, Constructor);
13312}
13313
13314void Sema::ActOnFinishDelayedMemberInitializers(Decl *D) {
13315 // Perform any delayed checks on exception specifications.
13316 CheckDelayedMemberExceptionSpecs();
13317}
13318
13319/// Find or create the fake constructor we synthesize to model constructing an
13320/// object of a derived class via a constructor of a base class.
13321CXXConstructorDecl *
13322Sema::findInheritingConstructor(SourceLocation Loc,
13323 CXXConstructorDecl *BaseCtor,
13324 ConstructorUsingShadowDecl *Shadow) {
13325 CXXRecordDecl *Derived = Shadow->getParent();
13326 SourceLocation UsingLoc = Shadow->getLocation();
13327
13328 // FIXME: Add a new kind of DeclarationName for an inherited constructor.
13329 // For now we use the name of the base class constructor as a member of the
13330 // derived class to indicate a (fake) inherited constructor name.
13331 DeclarationName Name = BaseCtor->getDeclName();
13332
13333 // Check to see if we already have a fake constructor for this inherited
13334 // constructor call.
13335 for (NamedDecl *Ctor : Derived->lookup(Name))
13336 if (declaresSameEntity(cast<CXXConstructorDecl>(Ctor)
13337 ->getInheritedConstructor()
13338 .getConstructor(),
13339 BaseCtor))
13340 return cast<CXXConstructorDecl>(Ctor);
13341
13342 DeclarationNameInfo NameInfo(Name, UsingLoc);
13343 TypeSourceInfo *TInfo =
13344 Context.getTrivialTypeSourceInfo(BaseCtor->getType(), UsingLoc);
13345 FunctionProtoTypeLoc ProtoLoc =
13346 TInfo->getTypeLoc().IgnoreParens().castAs<FunctionProtoTypeLoc>();
13347
13348 // Check the inherited constructor is valid and find the list of base classes
13349 // from which it was inherited.
13350 InheritedConstructorInfo ICI(*this, Loc, Shadow);
13351
13352 bool Constexpr =
13353 BaseCtor->isConstexpr() &&
13354 defaultedSpecialMemberIsConstexpr(*this, Derived, CXXDefaultConstructor,
13355 false, BaseCtor, &ICI);
13356
13357 CXXConstructorDecl *DerivedCtor = CXXConstructorDecl::Create(
13358 Context, Derived, UsingLoc, NameInfo, TInfo->getType(), TInfo,
13359 BaseCtor->getExplicitSpecifier(), /*isInline=*/true,
13360 /*isImplicitlyDeclared=*/true,
13361 Constexpr ? BaseCtor->getConstexprKind() : ConstexprSpecKind::Unspecified,
13362 InheritedConstructor(Shadow, BaseCtor),
13363 BaseCtor->getTrailingRequiresClause());
13364 if (Shadow->isInvalidDecl())
13365 DerivedCtor->setInvalidDecl();
13366
13367 // Build an unevaluated exception specification for this fake constructor.
13368 const FunctionProtoType *FPT = TInfo->getType()->castAs<FunctionProtoType>();
13369 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
13370 EPI.ExceptionSpec.Type = EST_Unevaluated;
13371 EPI.ExceptionSpec.SourceDecl = DerivedCtor;
13372 DerivedCtor->setType(Context.getFunctionType(FPT->getReturnType(),
13373 FPT->getParamTypes(), EPI));
13374
13375 // Build the parameter declarations.
13376 SmallVector<ParmVarDecl *, 16> ParamDecls;
13377 for (unsigned I = 0, N = FPT->getNumParams(); I != N; ++I) {
13378 TypeSourceInfo *TInfo =
13379 Context.getTrivialTypeSourceInfo(FPT->getParamType(I), UsingLoc);
13380 ParmVarDecl *PD = ParmVarDecl::Create(
13381 Context, DerivedCtor, UsingLoc, UsingLoc, /*IdentifierInfo=*/nullptr,
13382 FPT->getParamType(I), TInfo, SC_None, /*DefArg=*/nullptr);
13383 PD->setScopeInfo(0, I);
13384 PD->setImplicit();
13385 // Ensure attributes are propagated onto parameters (this matters for
13386 // format, pass_object_size, ...).
13387 mergeDeclAttributes(PD, BaseCtor->getParamDecl(I));
13388 ParamDecls.push_back(PD);
13389 ProtoLoc.setParam(I, PD);
13390 }
13391
13392 // Set up the new constructor.
13393 assert(!BaseCtor->isDeleted() && "should not use deleted constructor")((void)0);
13394 DerivedCtor->setAccess(BaseCtor->getAccess());
13395 DerivedCtor->setParams(ParamDecls);
13396 Derived->addDecl(DerivedCtor);
13397
13398 if (ShouldDeleteSpecialMember(DerivedCtor, CXXDefaultConstructor, &ICI))
13399 SetDeclDeleted(DerivedCtor, UsingLoc);
13400
13401 return DerivedCtor;
13402}
13403
13404void Sema::NoteDeletedInheritingConstructor(CXXConstructorDecl *Ctor) {
13405 InheritedConstructorInfo ICI(*this, Ctor->getLocation(),
13406 Ctor->getInheritedConstructor().getShadowDecl());
13407 ShouldDeleteSpecialMember(Ctor, CXXDefaultConstructor, &ICI,
13408 /*Diagnose*/true);
13409}
13410
13411void Sema::DefineInheritingConstructor(SourceLocation CurrentLocation,
13412 CXXConstructorDecl *Constructor) {
13413 CXXRecordDecl *ClassDecl = Constructor->getParent();
13414 assert(Constructor->getInheritedConstructor() &&((void)0)
13415 !Constructor->doesThisDeclarationHaveABody() &&((void)0)
13416 !Constructor->isDeleted())((void)0);
13417 if (Constructor->willHaveBody() || Constructor->isInvalidDecl())
13418 return;
13419
13420 // Initializations are performed "as if by a defaulted default constructor",
13421 // so enter the appropriate scope.
13422 SynthesizedFunctionScope Scope(*this, Constructor);
13423
13424 // The exception specification is needed because we are defining the
13425 // function.
13426 ResolveExceptionSpec(CurrentLocation,
13427 Constructor->getType()->castAs<FunctionProtoType>());
13428 MarkVTableUsed(CurrentLocation, ClassDecl);
13429
13430 // Add a context note for diagnostics produced after this point.
13431 Scope.addContextNote(CurrentLocation);
13432
13433 ConstructorUsingShadowDecl *Shadow =
13434 Constructor->getInheritedConstructor().getShadowDecl();
13435 CXXConstructorDecl *InheritedCtor =
13436 Constructor->getInheritedConstructor().getConstructor();
13437
13438 // [class.inhctor.init]p1:
13439 // initialization proceeds as if a defaulted default constructor is used to
13440 // initialize the D object and each base class subobject from which the
13441 // constructor was inherited
13442
13443 InheritedConstructorInfo ICI(*this, CurrentLocation, Shadow);
13444 CXXRecordDecl *RD = Shadow->getParent();
13445 SourceLocation InitLoc = Shadow->getLocation();
13446
13447 // Build explicit initializers for all base classes from which the
13448 // constructor was inherited.
13449 SmallVector<CXXCtorInitializer*, 8> Inits;
13450 for (bool VBase : {false, true}) {
13451 for (CXXBaseSpecifier &B : VBase ? RD->vbases() : RD->bases()) {
13452 if (B.isVirtual() != VBase)
13453 continue;
13454
13455 auto *BaseRD = B.getType()->getAsCXXRecordDecl();
13456 if (!BaseRD)
13457 continue;
13458
13459 auto BaseCtor = ICI.findConstructorForBase(BaseRD, InheritedCtor);
13460 if (!BaseCtor.first)
13461 continue;
13462
13463 MarkFunctionReferenced(CurrentLocation, BaseCtor.first);
13464 ExprResult Init = new (Context) CXXInheritedCtorInitExpr(
13465 InitLoc, B.getType(), BaseCtor.first, VBase, BaseCtor.second);
13466
13467 auto *TInfo = Context.getTrivialTypeSourceInfo(B.getType(), InitLoc);
13468 Inits.push_back(new (Context) CXXCtorInitializer(
13469 Context, TInfo, VBase, InitLoc, Init.get(), InitLoc,
13470 SourceLocation()));
13471 }
13472 }
13473
13474 // We now proceed as if for a defaulted default constructor, with the relevant
13475 // initializers replaced.
13476
13477 if (SetCtorInitializers(Constructor, /*AnyErrors*/false, Inits)) {
13478 Constructor->setInvalidDecl();
13479 return;
13480 }
13481
13482 Constructor->setBody(new (Context) CompoundStmt(InitLoc));
13483 Constructor->markUsed(Context);
13484
13485 if (ASTMutationListener *L = getASTMutationListener()) {
13486 L->CompletedImplicitDefinition(Constructor);
13487 }
13488
13489 DiagnoseUninitializedFields(*this, Constructor);
13490}
13491
13492CXXDestructorDecl *Sema::DeclareImplicitDestructor(CXXRecordDecl *ClassDecl) {
13493 // C++ [class.dtor]p2:
13494 // If a class has no user-declared destructor, a destructor is
13495 // declared implicitly. An implicitly-declared destructor is an
13496 // inline public member of its class.
13497 assert(ClassDecl->needsImplicitDestructor())((void)0);
13498
13499 DeclaringSpecialMember DSM(*this, ClassDecl, CXXDestructor);
13500 if (DSM.isAlreadyBeingDeclared())
13501 return nullptr;
13502
13503 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
13504 CXXDestructor,
13505 false);
13506
13507 // Create the actual destructor declaration.
13508 CanQualType ClassType
13509 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
13510 SourceLocation ClassLoc = ClassDecl->getLocation();
13511 DeclarationName Name
13512 = Context.DeclarationNames.getCXXDestructorName(ClassType);
13513 DeclarationNameInfo NameInfo(Name, ClassLoc);
13514 CXXDestructorDecl *Destructor =
13515 CXXDestructorDecl::Create(Context, ClassDecl, ClassLoc, NameInfo,
13516 QualType(), nullptr, /*isInline=*/true,
13517 /*isImplicitlyDeclared=*/true,
13518 Constexpr ? ConstexprSpecKind::Constexpr
13519 : ConstexprSpecKind::Unspecified);
13520 Destructor->setAccess(AS_public);
13521 Destructor->setDefaulted();
13522
13523 if (getLangOpts().CUDA) {
13524 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDestructor,
13525 Destructor,
13526 /* ConstRHS */ false,
13527 /* Diagnose */ false);
13528 }
13529
13530 setupImplicitSpecialMemberType(Destructor, Context.VoidTy, None);
13531
13532 // We don't need to use SpecialMemberIsTrivial here; triviality for
13533 // destructors is easy to compute.
13534 Destructor->setTrivial(ClassDecl->hasTrivialDestructor());
13535 Destructor->setTrivialForCall(ClassDecl->hasAttr<TrivialABIAttr>() ||
13536 ClassDecl->hasTrivialDestructorForCall());
13537
13538 // Note that we have declared this destructor.
13539 ++getASTContext().NumImplicitDestructorsDeclared;
13540
13541 Scope *S = getScopeForContext(ClassDecl);
13542 CheckImplicitSpecialMemberDeclaration(S, Destructor);
13543
13544 // We can't check whether an implicit destructor is deleted before we complete
13545 // the definition of the class, because its validity depends on the alignment
13546 // of the class. We'll check this from ActOnFields once the class is complete.
13547 if (ClassDecl->isCompleteDefinition() &&
13548 ShouldDeleteSpecialMember(Destructor, CXXDestructor))
13549 SetDeclDeleted(Destructor, ClassLoc);
13550
13551 // Introduce this destructor into its scope.
13552 if (S)
13553 PushOnScopeChains(Destructor, S, false);
13554 ClassDecl->addDecl(Destructor);
13555
13556 return Destructor;
13557}
13558
13559void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation,
13560 CXXDestructorDecl *Destructor) {
13561 assert((Destructor->isDefaulted() &&((void)0)
13562 !Destructor->doesThisDeclarationHaveABody() &&((void)0)
13563 !Destructor->isDeleted()) &&((void)0)
13564 "DefineImplicitDestructor - call it for implicit default dtor")((void)0);
13565 if (Destructor->willHaveBody() || Destructor->isInvalidDecl())
13566 return;
13567
13568 CXXRecordDecl *ClassDecl = Destructor->getParent();
13569 assert(ClassDecl && "DefineImplicitDestructor - invalid destructor")((void)0);
13570
13571 SynthesizedFunctionScope Scope(*this, Destructor);
13572
13573 // The exception specification is needed because we are defining the
13574 // function.
13575 ResolveExceptionSpec(CurrentLocation,
13576 Destructor->getType()->castAs<FunctionProtoType>());
13577 MarkVTableUsed(CurrentLocation, ClassDecl);
13578
13579 // Add a context note for diagnostics produced after this point.
13580 Scope.addContextNote(CurrentLocation);
13581
13582 MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(),
13583 Destructor->getParent());
13584
13585 if (CheckDestructor(Destructor)) {
13586 Destructor->setInvalidDecl();
13587 return;
13588 }
13589
13590 SourceLocation Loc = Destructor->getEndLoc().isValid()
13591 ? Destructor->getEndLoc()
13592 : Destructor->getLocation();
13593 Destructor->setBody(new (Context) CompoundStmt(Loc));
13594 Destructor->markUsed(Context);
13595
13596 if (ASTMutationListener *L = getASTMutationListener()) {
13597 L->CompletedImplicitDefinition(Destructor);
13598 }
13599}
13600
13601void Sema::CheckCompleteDestructorVariant(SourceLocation CurrentLocation,
13602 CXXDestructorDecl *Destructor) {
13603 if (Destructor->isInvalidDecl())
13604 return;
13605
13606 CXXRecordDecl *ClassDecl = Destructor->getParent();
13607 assert(Context.getTargetInfo().getCXXABI().isMicrosoft() &&((void)0)
13608 "implicit complete dtors unneeded outside MS ABI")((void)0);
13609 assert(ClassDecl->getNumVBases() > 0 &&((void)0)
13610 "complete dtor only exists for classes with vbases")((void)0);
13611
13612 SynthesizedFunctionScope Scope(*this, Destructor);
13613
13614 // Add a context note for diagnostics produced after this point.
13615 Scope.addContextNote(CurrentLocation);
13616
13617 MarkVirtualBaseDestructorsReferenced(Destructor->getLocation(), ClassDecl);
13618}
13619
13620/// Perform any semantic analysis which needs to be delayed until all
13621/// pending class member declarations have been parsed.
13622void Sema::ActOnFinishCXXMemberDecls() {
13623 // If the context is an invalid C++ class, just suppress these checks.
13624 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(CurContext)) {
13625 if (Record->isInvalidDecl()) {
13626 DelayedOverridingExceptionSpecChecks.clear();
13627 DelayedEquivalentExceptionSpecChecks.clear();
13628 return;
13629 }
13630 checkForMultipleExportedDefaultConstructors(*this, Record);
13631 }
13632}
13633
13634void Sema::ActOnFinishCXXNonNestedClass() {
13635 referenceDLLExportedClassMethods();
13636
13637 if (!DelayedDllExportMemberFunctions.empty()) {
13638 SmallVector<CXXMethodDecl*, 4> WorkList;
13639 std::swap(DelayedDllExportMemberFunctions, WorkList);
13640 for (CXXMethodDecl *M : WorkList) {
13641 DefineDefaultedFunction(*this, M, M->getLocation());
13642
13643 // Pass the method to the consumer to get emitted. This is not necessary
13644 // for explicit instantiation definitions, as they will get emitted
13645 // anyway.
13646 if (M->getParent()->getTemplateSpecializationKind() !=
13647 TSK_ExplicitInstantiationDefinition)
13648 ActOnFinishInlineFunctionDef(M);
13649 }
13650 }
13651}
13652
13653void Sema::referenceDLLExportedClassMethods() {
13654 if (!DelayedDllExportClasses.empty()) {
13655 // Calling ReferenceDllExportedMembers might cause the current function to
13656 // be called again, so use a local copy of DelayedDllExportClasses.
13657 SmallVector<CXXRecordDecl *, 4> WorkList;
13658 std::swap(DelayedDllExportClasses, WorkList);
13659 for (CXXRecordDecl *Class : WorkList)
13660 ReferenceDllExportedMembers(*this, Class);
13661 }
13662}
13663
13664void Sema::AdjustDestructorExceptionSpec(CXXDestructorDecl *Destructor) {
13665 assert(getLangOpts().CPlusPlus11 &&((void)0)
13666 "adjusting dtor exception specs was introduced in c++11")((void)0);
13667
13668 if (Destructor->isDependentContext())
13669 return;
13670
13671 // C++11 [class.dtor]p3:
13672 // A declaration of a destructor that does not have an exception-
13673 // specification is implicitly considered to have the same exception-
13674 // specification as an implicit declaration.
13675 const auto *DtorType = Destructor->getType()->castAs<FunctionProtoType>();
13676 if (DtorType->hasExceptionSpec())
13677 return;
13678
13679 // Replace the destructor's type, building off the existing one. Fortunately,
13680 // the only thing of interest in the destructor type is its extended info.
13681 // The return and arguments are fixed.
13682 FunctionProtoType::ExtProtoInfo EPI = DtorType->getExtProtoInfo();
13683 EPI.ExceptionSpec.Type = EST_Unevaluated;
13684 EPI.ExceptionSpec.SourceDecl = Destructor;
13685 Destructor->setType(Context.getFunctionType(Context.VoidTy, None, EPI));
13686
13687 // FIXME: If the destructor has a body that could throw, and the newly created
13688 // spec doesn't allow exceptions, we should emit a warning, because this
13689 // change in behavior can break conforming C++03 programs at runtime.
13690 // However, we don't have a body or an exception specification yet, so it
13691 // needs to be done somewhere else.
13692}
13693
13694namespace {
13695/// An abstract base class for all helper classes used in building the
13696// copy/move operators. These classes serve as factory functions and help us
13697// avoid using the same Expr* in the AST twice.
13698class ExprBuilder {
13699 ExprBuilder(const ExprBuilder&) = delete;
13700 ExprBuilder &operator=(const ExprBuilder&) = delete;
13701
13702protected:
13703 static Expr *assertNotNull(Expr *E) {
13704 assert(E && "Expression construction must not fail.")((void)0);
13705 return E;
13706 }
13707
13708public:
13709 ExprBuilder() {}
13710 virtual ~ExprBuilder() {}
13711
13712 virtual Expr *build(Sema &S, SourceLocation Loc) const = 0;
13713};
13714
13715class RefBuilder: public ExprBuilder {
13716 VarDecl *Var;
13717 QualType VarType;
13718
13719public:
13720 Expr *build(Sema &S, SourceLocation Loc) const override {
13721 return assertNotNull(S.BuildDeclRefExpr(Var, VarType, VK_LValue, Loc));
13722 }
13723
13724 RefBuilder(VarDecl *Var, QualType VarType)
13725 : Var(Var), VarType(VarType) {}
13726};
13727
13728class ThisBuilder: public ExprBuilder {
13729public:
13730 Expr *build(Sema &S, SourceLocation Loc) const override {
13731 return assertNotNull(S.ActOnCXXThis(Loc).getAs<Expr>());
13732 }
13733};
13734
13735class CastBuilder: public ExprBuilder {
13736 const ExprBuilder &Builder;
13737 QualType Type;
13738 ExprValueKind Kind;
13739 const CXXCastPath &Path;
13740
13741public:
13742 Expr *build(Sema &S, SourceLocation Loc) const override {
13743 return assertNotNull(S.ImpCastExprToType(Builder.build(S, Loc), Type,
13744 CK_UncheckedDerivedToBase, Kind,
13745 &Path).get());
13746 }
13747
13748 CastBuilder(const ExprBuilder &Builder, QualType Type, ExprValueKind Kind,
13749 const CXXCastPath &Path)
13750 : Builder(Builder), Type(Type), Kind(Kind), Path(Path) {}
13751};
13752
13753class DerefBuilder: public ExprBuilder {
13754 const ExprBuilder &Builder;
13755
13756public:
13757 Expr *build(Sema &S, SourceLocation Loc) const override {
13758 return assertNotNull(
13759 S.CreateBuiltinUnaryOp(Loc, UO_Deref, Builder.build(S, Loc)).get());
13760 }
13761
13762 DerefBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
13763};
13764
13765class MemberBuilder: public ExprBuilder {
13766 const ExprBuilder &Builder;
13767 QualType Type;
13768 CXXScopeSpec SS;
13769 bool IsArrow;
13770 LookupResult &MemberLookup;
13771
13772public:
13773 Expr *build(Sema &S, SourceLocation Loc) const override {
13774 return assertNotNull(S.BuildMemberReferenceExpr(
13775 Builder.build(S, Loc), Type, Loc, IsArrow, SS, SourceLocation(),
13776 nullptr, MemberLookup, nullptr, nullptr).get());
13777 }
13778
13779 MemberBuilder(const ExprBuilder &Builder, QualType Type, bool IsArrow,
13780 LookupResult &MemberLookup)
13781 : Builder(Builder), Type(Type), IsArrow(IsArrow),
13782 MemberLookup(MemberLookup) {}
13783};
13784
13785class MoveCastBuilder: public ExprBuilder {
13786 const ExprBuilder &Builder;
13787
13788public:
13789 Expr *build(Sema &S, SourceLocation Loc) const override {
13790 return assertNotNull(CastForMoving(S, Builder.build(S, Loc)));
13791 }
13792
13793 MoveCastBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
13794};
13795
13796class LvalueConvBuilder: public ExprBuilder {
13797 const ExprBuilder &Builder;
13798
13799public:
13800 Expr *build(Sema &S, SourceLocation Loc) const override {
13801 return assertNotNull(
13802 S.DefaultLvalueConversion(Builder.build(S, Loc)).get());
13803 }
13804
13805 LvalueConvBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
13806};
13807
13808class SubscriptBuilder: public ExprBuilder {
13809 const ExprBuilder &Base;
13810 const ExprBuilder &Index;
13811
13812public:
13813 Expr *build(Sema &S, SourceLocation Loc) const override {
13814 return assertNotNull(S.CreateBuiltinArraySubscriptExpr(
13815 Base.build(S, Loc), Loc, Index.build(S, Loc), Loc).get());
13816 }
13817
13818 SubscriptBuilder(const ExprBuilder &Base, const ExprBuilder &Index)
13819 : Base(Base), Index(Index) {}
13820};
13821
13822} // end anonymous namespace
13823
13824/// When generating a defaulted copy or move assignment operator, if a field
13825/// should be copied with __builtin_memcpy rather than via explicit assignments,
13826/// do so. This optimization only applies for arrays of scalars, and for arrays
13827/// of class type where the selected copy/move-assignment operator is trivial.
13828static StmtResult
13829buildMemcpyForAssignmentOp(Sema &S, SourceLocation Loc, QualType T,
13830 const ExprBuilder &ToB, const ExprBuilder &FromB) {
13831 // Compute the size of the memory buffer to be copied.
13832 QualType SizeType = S.Context.getSizeType();
13833 llvm::APInt Size(S.Context.getTypeSize(SizeType),
13834 S.Context.getTypeSizeInChars(T).getQuantity());
13835
13836 // Take the address of the field references for "from" and "to". We
13837 // directly construct UnaryOperators here because semantic analysis
13838 // does not permit us to take the address of an xvalue.
13839 Expr *From = FromB.build(S, Loc);
13840 From = UnaryOperator::Create(
13841 S.Context, From, UO_AddrOf, S.Context.getPointerType(From->getType()),
13842 VK_PRValue, OK_Ordinary, Loc, false, S.CurFPFeatureOverrides());
13843 Expr *To = ToB.build(S, Loc);
13844 To = UnaryOperator::Create(
13845 S.Context, To, UO_AddrOf, S.Context.getPointerType(To->getType()),
13846 VK_PRValue, OK_Ordinary, Loc, false, S.CurFPFeatureOverrides());
13847
13848 const Type *E = T->getBaseElementTypeUnsafe();
13849 bool NeedsCollectableMemCpy =
13850 E->isRecordType() &&
13851 E->castAs<RecordType>()->getDecl()->hasObjectMember();
13852
13853 // Create a reference to the __builtin_objc_memmove_collectable function
13854 StringRef MemCpyName = NeedsCollectableMemCpy ?
13855 "__builtin_objc_memmove_collectable" :
13856 "__builtin_memcpy";
13857 LookupResult R(S, &S.Context.Idents.get(MemCpyName), Loc,
13858 Sema::LookupOrdinaryName);
13859 S.LookupName(R, S.TUScope, true);
13860
13861 FunctionDecl *MemCpy = R.getAsSingle<FunctionDecl>();
13862 if (!MemCpy)
13863 // Something went horribly wrong earlier, and we will have complained
13864 // about it.
13865 return StmtError();
13866
13867 ExprResult MemCpyRef = S.BuildDeclRefExpr(MemCpy, S.Context.BuiltinFnTy,
13868 VK_PRValue, Loc, nullptr);
13869 assert(MemCpyRef.isUsable() && "Builtin reference cannot fail")((void)0);
13870
13871 Expr *CallArgs[] = {
13872 To, From, IntegerLiteral::Create(S.Context, Size, SizeType, Loc)
13873 };
13874 ExprResult Call = S.BuildCallExpr(/*Scope=*/nullptr, MemCpyRef.get(),
13875 Loc, CallArgs, Loc);
13876
13877 assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!")((void)0);
13878 return Call.getAs<Stmt>();
13879}
13880
13881/// Builds a statement that copies/moves the given entity from \p From to
13882/// \c To.
13883///
13884/// This routine is used to copy/move the members of a class with an
13885/// implicitly-declared copy/move assignment operator. When the entities being
13886/// copied are arrays, this routine builds for loops to copy them.
13887///
13888/// \param S The Sema object used for type-checking.
13889///
13890/// \param Loc The location where the implicit copy/move is being generated.
13891///
13892/// \param T The type of the expressions being copied/moved. Both expressions
13893/// must have this type.
13894///
13895/// \param To The expression we are copying/moving to.
13896///
13897/// \param From The expression we are copying/moving from.
13898///
13899/// \param CopyingBaseSubobject Whether we're copying/moving a base subobject.
13900/// Otherwise, it's a non-static member subobject.
13901///
13902/// \param Copying Whether we're copying or moving.
13903///
13904/// \param Depth Internal parameter recording the depth of the recursion.
13905///
13906/// \returns A statement or a loop that copies the expressions, or StmtResult(0)
13907/// if a memcpy should be used instead.
13908static StmtResult
13909buildSingleCopyAssignRecursively(Sema &S, SourceLocation Loc, QualType T,
13910 const ExprBuilder &To, const ExprBuilder &From,
13911 bool CopyingBaseSubobject, bool Copying,
13912 unsigned Depth = 0) {
13913 // C++11 [class.copy]p28:
13914 // Each subobject is assigned in the manner appropriate to its type:
13915 //
13916 // - if the subobject is of class type, as if by a call to operator= with
13917 // the subobject as the object expression and the corresponding
13918 // subobject of x as a single function argument (as if by explicit
13919 // qualification; that is, ignoring any possible virtual overriding
13920 // functions in more derived classes);
13921 //
13922 // C++03 [class.copy]p13:
13923 // - if the subobject is of class type, the copy assignment operator for
13924 // the class is used (as if by explicit qualification; that is,
13925 // ignoring any possible virtual overriding functions in more derived
13926 // classes);
13927 if (const RecordType *RecordTy = T->getAs<RecordType>()) {
13928 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
13929
13930 // Look for operator=.
13931 DeclarationName Name
13932 = S.Context.DeclarationNames.getCXXOperatorName(OO_Equal);
13933 LookupResult OpLookup(S, Name, Loc, Sema::LookupOrdinaryName);
13934 S.LookupQualifiedName(OpLookup, ClassDecl, false);
13935
13936 // Prior to C++11, filter out any result that isn't a copy/move-assignment
13937 // operator.
13938 if (!S.getLangOpts().CPlusPlus11) {
13939 LookupResult::Filter F = OpLookup.makeFilter();
13940 while (F.hasNext()) {
13941 NamedDecl *D = F.next();
13942 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
13943 if (Method->isCopyAssignmentOperator() ||
13944 (!Copying && Method->isMoveAssignmentOperator()))
13945 continue;
13946
13947 F.erase();
13948 }
13949 F.done();
13950 }
13951
13952 // Suppress the protected check (C++ [class.protected]) for each of the
13953 // assignment operators we found. This strange dance is required when
13954 // we're assigning via a base classes's copy-assignment operator. To
13955 // ensure that we're getting the right base class subobject (without
13956 // ambiguities), we need to cast "this" to that subobject type; to
13957 // ensure that we don't go through the virtual call mechanism, we need
13958 // to qualify the operator= name with the base class (see below). However,
13959 // this means that if the base class has a protected copy assignment
13960 // operator, the protected member access check will fail. So, we
13961 // rewrite "protected" access to "public" access in this case, since we
13962 // know by construction that we're calling from a derived class.
13963 if (CopyingBaseSubobject) {
13964 for (LookupResult::iterator L = OpLookup.begin(), LEnd = OpLookup.end();
13965 L != LEnd; ++L) {
13966 if (L.getAccess() == AS_protected)
13967 L.setAccess(AS_public);
13968 }
13969 }
13970
13971 // Create the nested-name-specifier that will be used to qualify the
13972 // reference to operator=; this is required to suppress the virtual
13973 // call mechanism.
13974 CXXScopeSpec SS;
13975 const Type *CanonicalT = S.Context.getCanonicalType(T.getTypePtr());
13976 SS.MakeTrivial(S.Context,
13977 NestedNameSpecifier::Create(S.Context, nullptr, false,
13978 CanonicalT),
13979 Loc);
13980
13981 // Create the reference to operator=.
13982 ExprResult OpEqualRef
13983 = S.BuildMemberReferenceExpr(To.build(S, Loc), T, Loc, /*IsArrow=*/false,
13984 SS, /*TemplateKWLoc=*/SourceLocation(),
13985 /*FirstQualifierInScope=*/nullptr,
13986 OpLookup,
13987 /*TemplateArgs=*/nullptr, /*S*/nullptr,
13988 /*SuppressQualifierCheck=*/true);
13989 if (OpEqualRef.isInvalid())
13990 return StmtError();
13991
13992 // Build the call to the assignment operator.
13993
13994 Expr *FromInst = From.build(S, Loc);
13995 ExprResult Call = S.BuildCallToMemberFunction(/*Scope=*/nullptr,
13996 OpEqualRef.getAs<Expr>(),
13997 Loc, FromInst, Loc);
13998 if (Call.isInvalid())
13999 return StmtError();
14000
14001 // If we built a call to a trivial 'operator=' while copying an array,
14002 // bail out. We'll replace the whole shebang with a memcpy.
14003 CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(Call.get());
14004 if (CE && CE->getMethodDecl()->isTrivial() && Depth)
14005 return StmtResult((Stmt*)nullptr);
14006
14007 // Convert to an expression-statement, and clean up any produced
14008 // temporaries.
14009 return S.ActOnExprStmt(Call);
14010 }
14011
14012 // - if the subobject is of scalar type, the built-in assignment
14013 // operator is used.
14014 const ConstantArrayType *ArrayTy = S.Context.getAsConstantArrayType(T);
14015 if (!ArrayTy) {
14016 ExprResult Assignment = S.CreateBuiltinBinOp(
14017 Loc, BO_Assign, To.build(S, Loc), From.build(S, Loc));
14018 if (Assignment.isInvalid())
14019 return StmtError();
14020 return S.ActOnExprStmt(Assignment);
14021 }
14022
14023 // - if the subobject is an array, each element is assigned, in the
14024 // manner appropriate to the element type;
14025
14026 // Construct a loop over the array bounds, e.g.,
14027 //
14028 // for (__SIZE_TYPE__ i0 = 0; i0 != array-size; ++i0)
14029 //
14030 // that will copy each of the array elements.
14031 QualType SizeType = S.Context.getSizeType();
14032
14033 // Create the iteration variable.
14034 IdentifierInfo *IterationVarName = nullptr;
14035 {
14036 SmallString<8> Str;
14037 llvm::raw_svector_ostream OS(Str);
14038 OS << "__i" << Depth;
14039 IterationVarName = &S.Context.Idents.get(OS.str());
14040 }
14041 VarDecl *IterationVar = VarDecl::Create(S.Context, S.CurContext, Loc, Loc,
14042 IterationVarName, SizeType,
14043 S.Context.getTrivialTypeSourceInfo(SizeType, Loc),
14044 SC_None);
14045
14046 // Initialize the iteration variable to zero.
14047 llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
14048 IterationVar->setInit(IntegerLiteral::Create(S.Context, Zero, SizeType, Loc));
14049
14050 // Creates a reference to the iteration variable.
14051 RefBuilder IterationVarRef(IterationVar, SizeType);
14052 LvalueConvBuilder IterationVarRefRVal(IterationVarRef);
14053
14054 // Create the DeclStmt that holds the iteration variable.
14055 Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(IterationVar),Loc,Loc);
14056
14057 // Subscript the "from" and "to" expressions with the iteration variable.
14058 SubscriptBuilder FromIndexCopy(From, IterationVarRefRVal);
14059 MoveCastBuilder FromIndexMove(FromIndexCopy);
14060 const ExprBuilder *FromIndex;
14061 if (Copying)
14062 FromIndex = &FromIndexCopy;
14063 else
14064 FromIndex = &FromIndexMove;
14065
14066 SubscriptBuilder ToIndex(To, IterationVarRefRVal);
14067
14068 // Build the copy/move for an individual element of the array.
14069 StmtResult Copy =
14070 buildSingleCopyAssignRecursively(S, Loc, ArrayTy->getElementType(),
14071 ToIndex, *FromIndex, CopyingBaseSubobject,
14072 Copying, Depth + 1);
14073 // Bail out if copying fails or if we determined that we should use memcpy.
14074 if (Copy.isInvalid() || !Copy.get())
14075 return Copy;
14076
14077 // Create the comparison against the array bound.
14078 llvm::APInt Upper
14079 = ArrayTy->getSize().zextOrTrunc(S.Context.getTypeSize(SizeType));
14080 Expr *Comparison = BinaryOperator::Create(
14081 S.Context, IterationVarRefRVal.build(S, Loc),
14082 IntegerLiteral::Create(S.Context, Upper, SizeType, Loc), BO_NE,
14083 S.Context.BoolTy, VK_PRValue, OK_Ordinary, Loc,
14084 S.CurFPFeatureOverrides());
14085
14086 // Create the pre-increment of the iteration variable. We can determine
14087 // whether the increment will overflow based on the value of the array
14088 // bound.
14089 Expr *Increment = UnaryOperator::Create(
14090 S.Context, IterationVarRef.build(S, Loc), UO_PreInc, SizeType, VK_LValue,
14091 OK_Ordinary, Loc, Upper.isMaxValue(), S.CurFPFeatureOverrides());
14092
14093 // Construct the loop that copies all elements of this array.
14094 return S.ActOnForStmt(
14095 Loc, Loc, InitStmt,
14096 S.ActOnCondition(nullptr, Loc, Comparison, Sema::ConditionKind::Boolean),
14097 S.MakeFullDiscardedValueExpr(Increment), Loc, Copy.get());
14098}
14099
14100static StmtResult
14101buildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
14102 const ExprBuilder &To, const ExprBuilder &From,
14103 bool CopyingBaseSubobject, bool Copying) {
14104 // Maybe we should use a memcpy?
14105 if (T->isArrayType() && !T.isConstQualified() && !T.isVolatileQualified() &&
14106 T.isTriviallyCopyableType(S.Context))
14107 return buildMemcpyForAssignmentOp(S, Loc, T, To, From);
14108
14109 StmtResult Result(buildSingleCopyAssignRecursively(S, Loc, T, To, From,
14110 CopyingBaseSubobject,
14111 Copying, 0));
14112
14113 // If we ended up picking a trivial assignment operator for an array of a
14114 // non-trivially-copyable class type, just emit a memcpy.
14115 if (!Result.isInvalid() && !Result.get())
14116 return buildMemcpyForAssignmentOp(S, Loc, T, To, From);
14117
14118 return Result;
14119}
14120
14121CXXMethodDecl *Sema::DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl) {
14122 // Note: The following rules are largely analoguous to the copy
14123 // constructor rules. Note that virtual bases are not taken into account
14124 // for determining the argument type of the operator. Note also that
14125 // operators taking an object instead of a reference are allowed.
14126 assert(ClassDecl->needsImplicitCopyAssignment())((void)0);
14127
14128 DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyAssignment);
14129 if (DSM.isAlreadyBeingDeclared())
14130 return nullptr;
14131
14132 QualType ArgType = Context.getTypeDeclType(ClassDecl);
14133 LangAS AS = getDefaultCXXMethodAddrSpace();
14134 if (AS != LangAS::Default)
14135 ArgType = Context.getAddrSpaceQualType(ArgType, AS);
14136 QualType RetType = Context.getLValueReferenceType(ArgType);
14137 bool Const = ClassDecl->implicitCopyAssignmentHasConstParam();
14138 if (Const)
14139 ArgType = ArgType.withConst();
14140
14141 ArgType = Context.getLValueReferenceType(ArgType);
14142
14143 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
14144 CXXCopyAssignment,
14145 Const);
14146
14147 // An implicitly-declared copy assignment operator is an inline public
14148 // member of its class.
14149 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
14150 SourceLocation ClassLoc = ClassDecl->getLocation();
14151 DeclarationNameInfo NameInfo(Name, ClassLoc);
14152 CXXMethodDecl *CopyAssignment = CXXMethodDecl::Create(
14153 Context, ClassDecl, ClassLoc, NameInfo, QualType(),
14154 /*TInfo=*/nullptr, /*StorageClass=*/SC_None,
14155 /*isInline=*/true,
14156 Constexpr ? ConstexprSpecKind::Constexpr : ConstexprSpecKind::Unspecified,
14157 SourceLocation());
14158 CopyAssignment->setAccess(AS_public);
14159 CopyAssignment->setDefaulted();
14160 CopyAssignment->setImplicit();
14161
14162 if (getLangOpts().CUDA) {
14163 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyAssignment,
14164 CopyAssignment,
14165 /* ConstRHS */ Const,
14166 /* Diagnose */ false);
14167 }
14168
14169 setupImplicitSpecialMemberType(CopyAssignment, RetType, ArgType);
14170
14171 // Add the parameter to the operator.
14172 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment,
14173 ClassLoc, ClassLoc,
14174 /*Id=*/nullptr, ArgType,
14175 /*TInfo=*/nullptr, SC_None,
14176 nullptr);
14177 CopyAssignment->setParams(FromParam);
14178
14179 CopyAssignment->setTrivial(
14180 ClassDecl->needsOverloadResolutionForCopyAssignment()
14181 ? SpecialMemberIsTrivial(CopyAssignment, CXXCopyAssignment)
14182 : ClassDecl->hasTrivialCopyAssignment());
14183
14184 // Note that we have added this copy-assignment operator.
14185 ++getASTContext().NumImplicitCopyAssignmentOperatorsDeclared;
14186
14187 Scope *S = getScopeForContext(ClassDecl);
14188 CheckImplicitSpecialMemberDeclaration(S, CopyAssignment);
14189
14190 if (ShouldDeleteSpecialMember(CopyAssignment, CXXCopyAssignment)) {
14191 ClassDecl->setImplicitCopyAssignmentIsDeleted();
14192 SetDeclDeleted(CopyAssignment, ClassLoc);
14193 }
14194
14195 if (S)
14196 PushOnScopeChains(CopyAssignment, S, false);
14197 ClassDecl->addDecl(CopyAssignment);
14198
14199 return CopyAssignment;
14200}
14201
14202/// Diagnose an implicit copy operation for a class which is odr-used, but
14203/// which is deprecated because the class has a user-declared copy constructor,
14204/// copy assignment operator, or destructor.
14205static void diagnoseDeprecatedCopyOperation(Sema &S, CXXMethodDecl *CopyOp) {
14206 assert(CopyOp->isImplicit())((void)0);
14207
14208 CXXRecordDecl *RD = CopyOp->getParent();
14209 CXXMethodDecl *UserDeclaredOperation = nullptr;
14210
14211 // In Microsoft mode, assignment operations don't affect constructors and
14212 // vice versa.
14213 if (RD->hasUserDeclaredDestructor()) {
14214 UserDeclaredOperation = RD->getDestructor();
14215 } else if (!isa<CXXConstructorDecl>(CopyOp) &&
14216 RD->hasUserDeclaredCopyConstructor() &&
14217 !S.getLangOpts().MSVCCompat) {
14218 // Find any user-declared copy constructor.
14219 for (auto *I : RD->ctors()) {
14220 if (I->isCopyConstructor()) {
14221 UserDeclaredOperation = I;
14222 break;
14223 }
14224 }
14225 assert(UserDeclaredOperation)((void)0);
14226 } else if (isa<CXXConstructorDecl>(CopyOp) &&
14227 RD->hasUserDeclaredCopyAssignment() &&
14228 !S.getLangOpts().MSVCCompat) {
14229 // Find any user-declared move assignment operator.
14230 for (auto *I : RD->methods()) {
14231 if (I->isCopyAssignmentOperator()) {
14232 UserDeclaredOperation = I;
14233 break;
14234 }
14235 }
14236 assert(UserDeclaredOperation)((void)0);
14237 }
14238
14239 if (UserDeclaredOperation) {
14240 bool UDOIsUserProvided = UserDeclaredOperation->isUserProvided();
14241 bool UDOIsDestructor = isa<CXXDestructorDecl>(UserDeclaredOperation);
14242 bool IsCopyAssignment = !isa<CXXConstructorDecl>(CopyOp);
14243 unsigned DiagID =
14244 (UDOIsUserProvided && UDOIsDestructor)
14245 ? diag::warn_deprecated_copy_with_user_provided_dtor
14246 : (UDOIsUserProvided && !UDOIsDestructor)
14247 ? diag::warn_deprecated_copy_with_user_provided_copy
14248 : (!UDOIsUserProvided && UDOIsDestructor)
14249 ? diag::warn_deprecated_copy_with_dtor
14250 : diag::warn_deprecated_copy;
14251 S.Diag(UserDeclaredOperation->getLocation(), DiagID)
14252 << RD << IsCopyAssignment;
14253 }
14254}
14255
14256void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
14257 CXXMethodDecl *CopyAssignOperator) {
14258 assert((CopyAssignOperator->isDefaulted() &&((void)0)
14259 CopyAssignOperator->isOverloadedOperator() &&((void)0)
14260 CopyAssignOperator->getOverloadedOperator() == OO_Equal &&((void)0)
14261 !CopyAssignOperator->doesThisDeclarationHaveABody() &&((void)0)
14262 !CopyAssignOperator->isDeleted()) &&((void)0)
14263 "DefineImplicitCopyAssignment called for wrong function")((void)0);
14264 if (CopyAssignOperator->willHaveBody() || CopyAssignOperator->isInvalidDecl())
14265 return;
14266
14267 CXXRecordDecl *ClassDecl = CopyAssignOperator->getParent();
14268 if (ClassDecl->isInvalidDecl()) {
14269 CopyAssignOperator->setInvalidDecl();
14270 return;
14271 }
14272
14273 SynthesizedFunctionScope Scope(*this, CopyAssignOperator);
14274
14275 // The exception specification is needed because we are defining the
14276 // function.
14277 ResolveExceptionSpec(CurrentLocation,
14278 CopyAssignOperator->getType()->castAs<FunctionProtoType>());
14279
14280 // Add a context note for diagnostics produced after this point.
14281 Scope.addContextNote(CurrentLocation);
14282
14283 // C++11 [class.copy]p18:
14284 // The [definition of an implicitly declared copy assignment operator] is
14285 // deprecated if the class has a user-declared copy constructor or a
14286 // user-declared destructor.
14287 if (getLangOpts().CPlusPlus11 && CopyAssignOperator->isImplicit())
14288 diagnoseDeprecatedCopyOperation(*this, CopyAssignOperator);
14289
14290 // C++0x [class.copy]p30:
14291 // The implicitly-defined or explicitly-defaulted copy assignment operator
14292 // for a non-union class X performs memberwise copy assignment of its
14293 // subobjects. The direct base classes of X are assigned first, in the
14294 // order of their declaration in the base-specifier-list, and then the
14295 // immediate non-static data members of X are assigned, in the order in
14296 // which they were declared in the class definition.
14297
14298 // The statements that form the synthesized function body.
14299 SmallVector<Stmt*, 8> Statements;
14300
14301 // The parameter for the "other" object, which we are copying from.
14302 ParmVarDecl *Other = CopyAssignOperator->getParamDecl(0);
14303 Qualifiers OtherQuals = Other->getType().getQualifiers();
14304 QualType OtherRefType = Other->getType();
14305 if (const LValueReferenceType *OtherRef
14306 = OtherRefType->getAs<LValueReferenceType>()) {
14307 OtherRefType = OtherRef->getPointeeType();
14308 OtherQuals = OtherRefType.getQualifiers();
14309 }
14310
14311 // Our location for everything implicitly-generated.
14312 SourceLocation Loc = CopyAssignOperator->getEndLoc().isValid()
14313 ? CopyAssignOperator->getEndLoc()
14314 : CopyAssignOperator->getLocation();
14315
14316 // Builds a DeclRefExpr for the "other" object.
14317 RefBuilder OtherRef(Other, OtherRefType);
14318
14319 // Builds the "this" pointer.
14320 ThisBuilder This;
14321
14322 // Assign base classes.
14323 bool Invalid = false;
14324 for (auto &Base : ClassDecl->bases()) {
14325 // Form the assignment:
14326 // static_cast<Base*>(this)->Base::operator=(static_cast<Base&>(other));
14327 QualType BaseType = Base.getType().getUnqualifiedType();
14328 if (!BaseType->isRecordType()) {
14329 Invalid = true;
14330 continue;
14331 }
14332
14333 CXXCastPath BasePath;
14334 BasePath.push_back(&Base);
14335
14336 // Construct the "from" expression, which is an implicit cast to the
14337 // appropriately-qualified base type.
14338 CastBuilder From(OtherRef, Context.getQualifiedType(BaseType, OtherQuals),
14339 VK_LValue, BasePath);
14340
14341 // Dereference "this".
14342 DerefBuilder DerefThis(This);
14343 CastBuilder To(DerefThis,
14344 Context.getQualifiedType(
14345 BaseType, CopyAssignOperator->getMethodQualifiers()),
14346 VK_LValue, BasePath);
14347
14348 // Build the copy.
14349 StmtResult Copy = buildSingleCopyAssign(*this, Loc, BaseType,
14350 To, From,
14351 /*CopyingBaseSubobject=*/true,
14352 /*Copying=*/true);
14353 if (Copy.isInvalid()) {
14354 CopyAssignOperator->setInvalidDecl();
14355 return;
14356 }
14357
14358 // Success! Record the copy.
14359 Statements.push_back(Copy.getAs<Expr>());
14360 }
14361
14362 // Assign non-static members.
14363 for (auto *Field : ClassDecl->fields()) {
14364 // FIXME: We should form some kind of AST representation for the implied
14365 // memcpy in a union copy operation.
14366 if (Field->isUnnamedBitfield() || Field->getParent()->isUnion())
14367 continue;
14368
14369 if (Field->isInvalidDecl()) {
14370 Invalid = true;
14371 continue;
14372 }
14373
14374 // Check for members of reference type; we can't copy those.
14375 if (Field->getType()->isReferenceType()) {
14376 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
14377 << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
14378 Diag(Field->getLocation(), diag::note_declared_at);
14379 Invalid = true;
14380 continue;
14381 }
14382
14383 // Check for members of const-qualified, non-class type.
14384 QualType BaseType = Context.getBaseElementType(Field->getType());
14385 if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
14386 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
14387 << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
14388 Diag(Field->getLocation(), diag::note_declared_at);
14389 Invalid = true;
14390 continue;
14391 }
14392
14393 // Suppress assigning zero-width bitfields.
14394 if (Field->isZeroLengthBitField(Context))
14395 continue;
14396
14397 QualType FieldType = Field->getType().getNonReferenceType();
14398 if (FieldType->isIncompleteArrayType()) {
14399 assert(ClassDecl->hasFlexibleArrayMember() &&((void)0)
14400 "Incomplete array type is not valid")((void)0);
14401 continue;
14402 }
14403
14404 // Build references to the field in the object we're copying from and to.
14405 CXXScopeSpec SS; // Intentionally empty
14406 LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
14407 LookupMemberName);
14408 MemberLookup.addDecl(Field);
14409 MemberLookup.resolveKind();
14410
14411 MemberBuilder From(OtherRef, OtherRefType, /*IsArrow=*/false, MemberLookup);
14412
14413 MemberBuilder To(This, getCurrentThisType(), /*IsArrow=*/true, MemberLookup);
14414
14415 // Build the copy of this field.
14416 StmtResult Copy = buildSingleCopyAssign(*this, Loc, FieldType,
14417 To, From,
14418 /*CopyingBaseSubobject=*/false,
14419 /*Copying=*/true);
14420 if (Copy.isInvalid()) {
14421 CopyAssignOperator->setInvalidDecl();
14422 return;
14423 }
14424
14425 // Success! Record the copy.
14426 Statements.push_back(Copy.getAs<Stmt>());
14427 }
14428
14429 if (!Invalid) {
14430 // Add a "return *this;"
14431 ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc));
14432
14433 StmtResult Return = BuildReturnStmt(Loc, ThisObj.get());
14434 if (Return.isInvalid())
14435 Invalid = true;
14436 else
14437 Statements.push_back(Return.getAs<Stmt>());
14438 }
14439
14440 if (Invalid) {
14441 CopyAssignOperator->setInvalidDecl();
14442 return;
14443 }
14444
14445 StmtResult Body;
14446 {
14447 CompoundScopeRAII CompoundScope(*this);
14448 Body = ActOnCompoundStmt(Loc, Loc, Statements,
14449 /*isStmtExpr=*/false);
14450 assert(!Body.isInvalid() && "Compound statement creation cannot fail")((void)0);
14451 }
14452 CopyAssignOperator->setBody(Body.getAs<Stmt>());
14453 CopyAssignOperator->markUsed(Context);
14454
14455 if (ASTMutationListener *L = getASTMutationListener()) {
14456 L->CompletedImplicitDefinition(CopyAssignOperator);
14457 }
14458}
14459
14460CXXMethodDecl *Sema::DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl) {
14461 assert(ClassDecl->needsImplicitMoveAssignment())((void)0);
14462
14463 DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveAssignment);
14464 if (DSM.isAlreadyBeingDeclared())
14465 return nullptr;
14466
14467 // Note: The following rules are largely analoguous to the move
14468 // constructor rules.
14469
14470 QualType ArgType = Context.getTypeDeclType(ClassDecl);
14471 LangAS AS = getDefaultCXXMethodAddrSpace();
14472 if (AS != LangAS::Default)
14473 ArgType = Context.getAddrSpaceQualType(ArgType, AS);
14474 QualType RetType = Context.getLValueReferenceType(ArgType);
14475 ArgType = Context.getRValueReferenceType(ArgType);
14476
14477 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
14478 CXXMoveAssignment,
14479 false);
14480
14481 // An implicitly-declared move assignment operator is an inline public
14482 // member of its class.
14483 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
14484 SourceLocation ClassLoc = ClassDecl->getLocation();
14485 DeclarationNameInfo NameInfo(Name, ClassLoc);
14486 CXXMethodDecl *MoveAssignment = CXXMethodDecl::Create(
14487 Context, ClassDecl, ClassLoc, NameInfo, QualType(),
14488 /*TInfo=*/nullptr, /*StorageClass=*/SC_None,
14489 /*isInline=*/true,
14490 Constexpr ? ConstexprSpecKind::Constexpr : ConstexprSpecKind::Unspecified,
14491 SourceLocation());
14492 MoveAssignment->setAccess(AS_public);
14493 MoveAssignment->setDefaulted();
14494 MoveAssignment->setImplicit();
14495
14496 if (getLangOpts().CUDA) {
14497 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveAssignment,
14498 MoveAssignment,
14499 /* ConstRHS */ false,
14500 /* Diagnose */ false);
14501 }
14502
14503 setupImplicitSpecialMemberType(MoveAssignment, RetType, ArgType);
14504
14505 // Add the parameter to the operator.
14506 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveAssignment,
14507 ClassLoc, ClassLoc,
14508 /*Id=*/nullptr, ArgType,
14509 /*TInfo=*/nullptr, SC_None,
14510 nullptr);
14511 MoveAssignment->setParams(FromParam);
14512
14513 MoveAssignment->setTrivial(
14514 ClassDecl->needsOverloadResolutionForMoveAssignment()
14515 ? SpecialMemberIsTrivial(MoveAssignment, CXXMoveAssignment)
14516 : ClassDecl->hasTrivialMoveAssignment());
14517
14518 // Note that we have added this copy-assignment operator.
14519 ++getASTContext().NumImplicitMoveAssignmentOperatorsDeclared;
14520
14521 Scope *S = getScopeForContext(ClassDecl);
14522 CheckImplicitSpecialMemberDeclaration(S, MoveAssignment);
14523
14524 if (ShouldDeleteSpecialMember(MoveAssignment, CXXMoveAssignment)) {
14525 ClassDecl->setImplicitMoveAssignmentIsDeleted();
14526 SetDeclDeleted(MoveAssignment, ClassLoc);
14527 }
14528
14529 if (S)
14530 PushOnScopeChains(MoveAssignment, S, false);
14531 ClassDecl->addDecl(MoveAssignment);
14532
14533 return MoveAssignment;
14534}
14535
14536/// Check if we're implicitly defining a move assignment operator for a class
14537/// with virtual bases. Such a move assignment might move-assign the virtual
14538/// base multiple times.
14539static void checkMoveAssignmentForRepeatedMove(Sema &S, CXXRecordDecl *Class,
14540 SourceLocation CurrentLocation) {
14541 assert(!Class->isDependentContext() && "should not define dependent move")((void)0);
14542
14543 // Only a virtual base could get implicitly move-assigned multiple times.
14544 // Only a non-trivial move assignment can observe this. We only want to
14545 // diagnose if we implicitly define an assignment operator that assigns
14546 // two base classes, both of which move-assign the same virtual base.
14547 if (Class->getNumVBases() == 0 || Class->hasTrivialMoveAssignment() ||
14548 Class->getNumBases() < 2)
14549 return;
14550
14551 llvm::SmallVector<CXXBaseSpecifier *, 16> Worklist;
14552 typedef llvm::DenseMap<CXXRecordDecl*, CXXBaseSpecifier*> VBaseMap;
14553 VBaseMap VBases;
14554
14555 for (auto &BI : Class->bases()) {
14556 Worklist.push_back(&BI);
14557 while (!Worklist.empty()) {
14558 CXXBaseSpecifier *BaseSpec = Worklist.pop_back_val();
14559 CXXRecordDecl *Base = BaseSpec->getType()->getAsCXXRecordDecl();
14560
14561 // If the base has no non-trivial move assignment operators,
14562 // we don't care about moves from it.
14563 if (!Base->hasNonTrivialMoveAssignment())
14564 continue;
14565
14566 // If there's nothing virtual here, skip it.
14567 if (!BaseSpec->isVirtual() && !Base->getNumVBases())
14568 continue;
14569
14570 // If we're not actually going to call a move assignment for this base,
14571 // or the selected move assignment is trivial, skip it.
14572 Sema::SpecialMemberOverloadResult SMOR =
14573 S.LookupSpecialMember(Base, Sema::CXXMoveAssignment,
14574 /*ConstArg*/false, /*VolatileArg*/false,
14575 /*RValueThis*/true, /*ConstThis*/false,
14576 /*VolatileThis*/false);
14577 if (!SMOR.getMethod() || SMOR.getMethod()->isTrivial() ||
14578 !SMOR.getMethod()->isMoveAssignmentOperator())
14579 continue;
14580
14581 if (BaseSpec->isVirtual()) {
14582 // We're going to move-assign this virtual base, and its move
14583 // assignment operator is not trivial. If this can happen for
14584 // multiple distinct direct bases of Class, diagnose it. (If it
14585 // only happens in one base, we'll diagnose it when synthesizing
14586 // that base class's move assignment operator.)
14587 CXXBaseSpecifier *&Existing =
14588 VBases.insert(std::make_pair(Base->getCanonicalDecl(), &BI))
14589 .first->second;
14590 if (Existing && Existing != &BI) {
14591 S.Diag(CurrentLocation, diag::warn_vbase_moved_multiple_times)
14592 << Class << Base;
14593 S.Diag(Existing->getBeginLoc(), diag::note_vbase_moved_here)
14594 << (Base->getCanonicalDecl() ==
14595 Existing->getType()->getAsCXXRecordDecl()->getCanonicalDecl())
14596 << Base << Existing->getType() << Existing->getSourceRange();
14597 S.Diag(BI.getBeginLoc(), diag::note_vbase_moved_here)
14598 << (Base->getCanonicalDecl() ==
14599 BI.getType()->getAsCXXRecordDecl()->getCanonicalDecl())
14600 << Base << BI.getType() << BaseSpec->getSourceRange();
14601
14602 // Only diagnose each vbase once.
14603 Existing = nullptr;
14604 }
14605 } else {
14606 // Only walk over bases that have defaulted move assignment operators.
14607 // We assume that any user-provided move assignment operator handles
14608 // the multiple-moves-of-vbase case itself somehow.
14609 if (!SMOR.getMethod()->isDefaulted())
14610 continue;
14611
14612 // We're going to move the base classes of Base. Add them to the list.
14613 for (auto &BI : Base->bases())
14614 Worklist.push_back(&BI);
14615 }
14616 }
14617 }
14618}
14619
14620void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
14621 CXXMethodDecl *MoveAssignOperator) {
14622 assert((MoveAssignOperator->isDefaulted() &&((void)0)
14623 MoveAssignOperator->isOverloadedOperator() &&((void)0)
14624 MoveAssignOperator->getOverloadedOperator() == OO_Equal &&((void)0)
14625 !MoveAssignOperator->doesThisDeclarationHaveABody() &&((void)0)
14626 !MoveAssignOperator->isDeleted()) &&((void)0)
14627 "DefineImplicitMoveAssignment called for wrong function")((void)0);
14628 if (MoveAssignOperator->willHaveBody() || MoveAssignOperator->isInvalidDecl())
14629 return;
14630
14631 CXXRecordDecl *ClassDecl = MoveAssignOperator->getParent();
14632 if (ClassDecl->isInvalidDecl()) {
14633 MoveAssignOperator->setInvalidDecl();
14634 return;
14635 }
14636
14637 // C++0x [class.copy]p28:
14638 // The implicitly-defined or move assignment operator for a non-union class
14639 // X performs memberwise move assignment of its subobjects. The direct base
14640 // classes of X are assigned first, in the order of their declaration in the
14641 // base-specifier-list, and then the immediate non-static data members of X
14642 // are assigned, in the order in which they were declared in the class
14643 // definition.
14644
14645 // Issue a warning if our implicit move assignment operator will move
14646 // from a virtual base more than once.
14647 checkMoveAssignmentForRepeatedMove(*this, ClassDecl, CurrentLocation);
14648
14649 SynthesizedFunctionScope Scope(*this, MoveAssignOperator);
14650
14651 // The exception specification is needed because we are defining the
14652 // function.
14653 ResolveExceptionSpec(CurrentLocation,
14654 MoveAssignOperator->getType()->castAs<FunctionProtoType>());
14655
14656 // Add a context note for diagnostics produced after this point.
14657 Scope.addContextNote(CurrentLocation);
14658
14659 // The statements that form the synthesized function body.
14660 SmallVector<Stmt*, 8> Statements;
14661
14662 // The parameter for the "other" object, which we are move from.
14663 ParmVarDecl *Other = MoveAssignOperator->getParamDecl(0);
14664 QualType OtherRefType =
14665 Other->getType()->castAs<RValueReferenceType>()->getPointeeType();
14666
14667 // Our location for everything implicitly-generated.
14668 SourceLocation Loc = MoveAssignOperator->getEndLoc().isValid()
14669 ? MoveAssignOperator->getEndLoc()
14670 : MoveAssignOperator->getLocation();
14671
14672 // Builds a reference to the "other" object.
14673 RefBuilder OtherRef(Other, OtherRefType);
14674 // Cast to rvalue.
14675 MoveCastBuilder MoveOther(OtherRef);
14676
14677 // Builds the "this" pointer.
14678 ThisBuilder This;
14679
14680 // Assign base classes.
14681 bool Invalid = false;
14682 for (auto &Base : ClassDecl->bases()) {
14683 // C++11 [class.copy]p28:
14684 // It is unspecified whether subobjects representing virtual base classes
14685 // are assigned more than once by the implicitly-defined copy assignment
14686 // operator.
14687 // FIXME: Do not assign to a vbase that will be assigned by some other base
14688 // class. For a move-assignment, this can result in the vbase being moved
14689 // multiple times.
14690
14691 // Form the assignment:
14692 // static_cast<Base*>(this)->Base::operator=(static_cast<Base&&>(other));
14693 QualType BaseType = Base.getType().getUnqualifiedType();
14694 if (!BaseType->isRecordType()) {
14695 Invalid = true;
14696 continue;
14697 }
14698
14699 CXXCastPath BasePath;
14700 BasePath.push_back(&Base);
14701
14702 // Construct the "from" expression, which is an implicit cast to the
14703 // appropriately-qualified base type.
14704 CastBuilder From(OtherRef, BaseType, VK_XValue, BasePath);
14705
14706 // Dereference "this".
14707 DerefBuilder DerefThis(This);
14708
14709 // Implicitly cast "this" to the appropriately-qualified base type.
14710 CastBuilder To(DerefThis,
14711 Context.getQualifiedType(
14712 BaseType, MoveAssignOperator->getMethodQualifiers()),
14713 VK_LValue, BasePath);
14714
14715 // Build the move.
14716 StmtResult Move = buildSingleCopyAssign(*this, Loc, BaseType,
14717 To, From,
14718 /*CopyingBaseSubobject=*/true,
14719 /*Copying=*/false);
14720 if (Move.isInvalid()) {
14721 MoveAssignOperator->setInvalidDecl();
14722 return;
14723 }
14724
14725 // Success! Record the move.
14726 Statements.push_back(Move.getAs<Expr>());
14727 }
14728
14729 // Assign non-static members.
14730 for (auto *Field : ClassDecl->fields()) {
14731 // FIXME: We should form some kind of AST representation for the implied
14732 // memcpy in a union copy operation.
14733 if (Field->isUnnamedBitfield() || Field->getParent()->isUnion())
14734 continue;
14735
14736 if (Field->isInvalidDecl()) {
14737 Invalid = true;
14738 continue;
14739 }
14740
14741 // Check for members of reference type; we can't move those.
14742 if (Field->getType()->isReferenceType()) {
14743 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
14744 << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
14745 Diag(Field->getLocation(), diag::note_declared_at);
14746 Invalid = true;
14747 continue;
14748 }
14749
14750 // Check for members of const-qualified, non-class type.
14751 QualType BaseType = Context.getBaseElementType(Field->getType());
14752 if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
14753 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
14754 << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
14755 Diag(Field->getLocation(), diag::note_declared_at);
14756 Invalid = true;
14757 continue;
14758 }
14759
14760 // Suppress assigning zero-width bitfields.
14761 if (Field->isZeroLengthBitField(Context))
14762 continue;
14763
14764 QualType FieldType = Field->getType().getNonReferenceType();
14765 if (FieldType->isIncompleteArrayType()) {
14766 assert(ClassDecl->hasFlexibleArrayMember() &&((void)0)
14767 "Incomplete array type is not valid")((void)0);
14768 continue;
14769 }
14770
14771 // Build references to the field in the object we're copying from and to.
14772 LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
14773 LookupMemberName);
14774 MemberLookup.addDecl(Field);
14775 MemberLookup.resolveKind();
14776 MemberBuilder From(MoveOther, OtherRefType,
14777 /*IsArrow=*/false, MemberLookup);
14778 MemberBuilder To(This, getCurrentThisType(),
14779 /*IsArrow=*/true, MemberLookup);
14780
14781 assert(!From.build(*this, Loc)->isLValue() && // could be xvalue or prvalue((void)0)
14782 "Member reference with rvalue base must be rvalue except for reference "((void)0)
14783 "members, which aren't allowed for move assignment.")((void)0);
14784
14785 // Build the move of this field.
14786 StmtResult Move = buildSingleCopyAssign(*this, Loc, FieldType,
14787 To, From,
14788 /*CopyingBaseSubobject=*/false,
14789 /*Copying=*/false);
14790 if (Move.isInvalid()) {
14791 MoveAssignOperator->setInvalidDecl();
14792 return;
14793 }
14794
14795 // Success! Record the copy.
14796 Statements.push_back(Move.getAs<Stmt>());
14797 }
14798
14799 if (!Invalid) {
14800 // Add a "return *this;"
14801 ExprResult ThisObj =
14802 CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc));
14803
14804 StmtResult Return = BuildReturnStmt(Loc, ThisObj.get());
14805 if (Return.isInvalid())
14806 Invalid = true;
14807 else
14808 Statements.push_back(Return.getAs<Stmt>());
14809 }
14810
14811 if (Invalid) {
14812 MoveAssignOperator->setInvalidDecl();
14813 return;
14814 }
14815
14816 StmtResult Body;
14817 {
14818 CompoundScopeRAII CompoundScope(*this);
14819 Body = ActOnCompoundStmt(Loc, Loc, Statements,
14820 /*isStmtExpr=*/false);
14821 assert(!Body.isInvalid() && "Compound statement creation cannot fail")((void)0);
14822 }
14823 MoveAssignOperator->setBody(Body.getAs<Stmt>());
14824 MoveAssignOperator->markUsed(Context);
14825
14826 if (ASTMutationListener *L = getASTMutationListener()) {
14827 L->CompletedImplicitDefinition(MoveAssignOperator);
14828 }
14829}
14830
14831CXXConstructorDecl *Sema::DeclareImplicitCopyConstructor(
14832 CXXRecordDecl *ClassDecl) {
14833 // C++ [class.copy]p4:
14834 // If the class definition does not explicitly declare a copy
14835 // constructor, one is declared implicitly.
14836 assert(ClassDecl->needsImplicitCopyConstructor())((void)0);
14837
14838 DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyConstructor);
14839 if (DSM.isAlreadyBeingDeclared())
14840 return nullptr;
14841
14842 QualType ClassType = Context.getTypeDeclType(ClassDecl);
14843 QualType ArgType = ClassType;
14844 bool Const = ClassDecl->implicitCopyConstructorHasConstParam();
14845 if (Const)
14846 ArgType = ArgType.withConst();
14847
14848 LangAS AS = getDefaultCXXMethodAddrSpace();
14849 if (AS != LangAS::Default)
14850 ArgType = Context.getAddrSpaceQualType(ArgType, AS);
14851
14852 ArgType = Context.getLValueReferenceType(ArgType);
14853
14854 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
14855 CXXCopyConstructor,
14856 Const);
14857
14858 DeclarationName Name
14859 = Context.DeclarationNames.getCXXConstructorName(
14860 Context.getCanonicalType(ClassType));
14861 SourceLocation ClassLoc = ClassDecl->getLocation();
14862 DeclarationNameInfo NameInfo(Name, ClassLoc);
14863
14864 // An implicitly-declared copy constructor is an inline public
14865 // member of its class.
14866 CXXConstructorDecl *CopyConstructor = CXXConstructorDecl::Create(
14867 Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr,
14868 ExplicitSpecifier(),
14869 /*isInline=*/true,
14870 /*isImplicitlyDeclared=*/true,
14871 Constexpr ? ConstexprSpecKind::Constexpr
14872 : ConstexprSpecKind::Unspecified);
14873 CopyConstructor->setAccess(AS_public);
14874 CopyConstructor->setDefaulted();
14875
14876 if (getLangOpts().CUDA) {
14877 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyConstructor,
14878 CopyConstructor,
14879 /* ConstRHS */ Const,
14880 /* Diagnose */ false);
14881 }
14882
14883 setupImplicitSpecialMemberType(CopyConstructor, Context.VoidTy, ArgType);
14884
14885 // During template instantiation of special member functions we need a
14886 // reliable TypeSourceInfo for the parameter types in order to allow functions
14887 // to be substituted.
14888 TypeSourceInfo *TSI = nullptr;
14889 if (inTemplateInstantiation() && ClassDecl->isLambda())
14890 TSI = Context.getTrivialTypeSourceInfo(ArgType);
14891
14892 // Add the parameter to the constructor.
14893 ParmVarDecl *FromParam =
14894 ParmVarDecl::Create(Context, CopyConstructor, ClassLoc, ClassLoc,
14895 /*IdentifierInfo=*/nullptr, ArgType,
14896 /*TInfo=*/TSI, SC_None, nullptr);
14897 CopyConstructor->setParams(FromParam);
14898
14899 CopyConstructor->setTrivial(
14900 ClassDecl->needsOverloadResolutionForCopyConstructor()
14901 ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor)
14902 : ClassDecl->hasTrivialCopyConstructor());
14903
14904 CopyConstructor->setTrivialForCall(
14905 ClassDecl->hasAttr<TrivialABIAttr>() ||
14906 (ClassDecl->needsOverloadResolutionForCopyConstructor()
14907 ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor,
14908 TAH_ConsiderTrivialABI)
14909 : ClassDecl->hasTrivialCopyConstructorForCall()));
14910
14911 // Note that we have declared this constructor.
14912 ++getASTContext().NumImplicitCopyConstructorsDeclared;
14913
14914 Scope *S = getScopeForContext(ClassDecl);
14915 CheckImplicitSpecialMemberDeclaration(S, CopyConstructor);
14916
14917 if (ShouldDeleteSpecialMember(CopyConstructor, CXXCopyConstructor)) {
14918 ClassDecl->setImplicitCopyConstructorIsDeleted();
14919 SetDeclDeleted(CopyConstructor, ClassLoc);
14920 }
14921
14922 if (S)
14923 PushOnScopeChains(CopyConstructor, S, false);
14924 ClassDecl->addDecl(CopyConstructor);
14925
14926 return CopyConstructor;
14927}
14928
14929void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
14930 CXXConstructorDecl *CopyConstructor) {
14931 assert((CopyConstructor->isDefaulted() &&((void)0)
14932 CopyConstructor->isCopyConstructor() &&((void)0)
14933 !CopyConstructor->doesThisDeclarationHaveABody() &&((void)0)
14934 !CopyConstructor->isDeleted()) &&((void)0)
14935 "DefineImplicitCopyConstructor - call it for implicit copy ctor")((void)0);
14936 if (CopyConstructor->willHaveBody() || CopyConstructor->isInvalidDecl())
14937 return;
14938
14939 CXXRecordDecl *ClassDecl = CopyConstructor->getParent();
14940 assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor")((void)0);
14941
14942 SynthesizedFunctionScope Scope(*this, CopyConstructor);
14943
14944 // The exception specification is needed because we are defining the
14945 // function.
14946 ResolveExceptionSpec(CurrentLocation,
14947 CopyConstructor->getType()->castAs<FunctionProtoType>());
14948 MarkVTableUsed(CurrentLocation, ClassDecl);
14949
14950 // Add a context note for diagnostics produced after this point.
14951 Scope.addContextNote(CurrentLocation);
14952
14953 // C++11 [class.copy]p7:
14954 // The [definition of an implicitly declared copy constructor] is
14955 // deprecated if the class has a user-declared copy assignment operator
14956 // or a user-declared destructor.
14957 if (getLangOpts().CPlusPlus11 && CopyConstructor->isImplicit())
14958 diagnoseDeprecatedCopyOperation(*this, CopyConstructor);
14959
14960 if (SetCtorInitializers(CopyConstructor, /*AnyErrors=*/false)) {
14961 CopyConstructor->setInvalidDecl();
14962 } else {
14963 SourceLocation Loc = CopyConstructor->getEndLoc().isValid()
14964 ? CopyConstructor->getEndLoc()
14965 : CopyConstructor->getLocation();
14966 Sema::CompoundScopeRAII CompoundScope(*this);
14967 CopyConstructor->setBody(
14968 ActOnCompoundStmt(Loc, Loc, None, /*isStmtExpr=*/false).getAs<Stmt>());
14969 CopyConstructor->markUsed(Context);
14970 }
14971
14972 if (ASTMutationListener *L = getASTMutationListener()) {
14973 L->CompletedImplicitDefinition(CopyConstructor);
14974 }
14975}
14976
14977CXXConstructorDecl *Sema::DeclareImplicitMoveConstructor(
14978 CXXRecordDecl *ClassDecl) {
14979 assert(ClassDecl->needsImplicitMoveConstructor())((void)0);
14980
14981 DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveConstructor);
14982 if (DSM.isAlreadyBeingDeclared())
14983 return nullptr;
14984
14985 QualType ClassType = Context.getTypeDeclType(ClassDecl);
14986
14987 QualType ArgType = ClassType;
14988 LangAS AS = getDefaultCXXMethodAddrSpace();
14989 if (AS != LangAS::Default)
14990 ArgType = Context.getAddrSpaceQualType(ClassType, AS);
14991 ArgType = Context.getRValueReferenceType(ArgType);
14992
14993 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
14994 CXXMoveConstructor,
14995 false);
14996
14997 DeclarationName Name
14998 = Context.DeclarationNames.getCXXConstructorName(
14999 Context.getCanonicalType(ClassType));
15000 SourceLocation ClassLoc = ClassDecl->getLocation();
15001 DeclarationNameInfo NameInfo(Name, ClassLoc);
15002
15003 // C++11 [class.copy]p11:
15004 // An implicitly-declared copy/move constructor is an inline public
15005 // member of its class.
15006 CXXConstructorDecl *MoveConstructor = CXXConstructorDecl::Create(
15007 Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr,
15008 ExplicitSpecifier(),
15009 /*isInline=*/true,
15010 /*isImplicitlyDeclared=*/true,
15011 Constexpr ? ConstexprSpecKind::Constexpr
15012 : ConstexprSpecKind::Unspecified);
15013 MoveConstructor->setAccess(AS_public);
15014 MoveConstructor->setDefaulted();
15015
15016 if (getLangOpts().CUDA) {
15017 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveConstructor,
15018 MoveConstructor,
15019 /* ConstRHS */ false,
15020 /* Diagnose */ false);
15021 }
15022
15023 setupImplicitSpecialMemberType(MoveConstructor, Context.VoidTy, ArgType);
15024
15025 // Add the parameter to the constructor.
15026 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveConstructor,
15027 ClassLoc, ClassLoc,
15028 /*IdentifierInfo=*/nullptr,
15029 ArgType, /*TInfo=*/nullptr,
15030 SC_None, nullptr);
15031 MoveConstructor->setParams(FromParam);
15032
15033 MoveConstructor->setTrivial(
15034 ClassDecl->needsOverloadResolutionForMoveConstructor()
15035 ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor)
15036 : ClassDecl->hasTrivialMoveConstructor());
15037
15038 MoveConstructor->setTrivialForCall(
15039 ClassDecl->hasAttr<TrivialABIAttr>() ||
15040 (ClassDecl->needsOverloadResolutionForMoveConstructor()
15041 ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor,
15042 TAH_ConsiderTrivialABI)
15043 : ClassDecl->hasTrivialMoveConstructorForCall()));
15044
15045 // Note that we have declared this constructor.
15046 ++getASTContext().NumImplicitMoveConstructorsDeclared;
15047
15048 Scope *S = getScopeForContext(ClassDecl);
15049 CheckImplicitSpecialMemberDeclaration(S, MoveConstructor);
15050
15051 if (ShouldDeleteSpecialMember(MoveConstructor, CXXMoveConstructor)) {
15052 ClassDecl->setImplicitMoveConstructorIsDeleted();
15053 SetDeclDeleted(MoveConstructor, ClassLoc);
15054 }
15055
15056 if (S)
15057 PushOnScopeChains(MoveConstructor, S, false);
15058 ClassDecl->addDecl(MoveConstructor);
15059
15060 return MoveConstructor;
15061}
15062
15063void Sema::DefineImplicitMoveConstructor(SourceLocation CurrentLocation,
15064 CXXConstructorDecl *MoveConstructor) {
15065 assert((MoveConstructor->isDefaulted() &&((void)0)
15066 MoveConstructor->isMoveConstructor() &&((void)0)
15067 !MoveConstructor->doesThisDeclarationHaveABody() &&((void)0)
15068 !MoveConstructor->isDeleted()) &&((void)0)
15069 "DefineImplicitMoveConstructor - call it for implicit move ctor")((void)0);
15070 if (MoveConstructor->willHaveBody() || MoveConstructor->isInvalidDecl())
15071 return;
15072
15073 CXXRecordDecl *ClassDecl = MoveConstructor->getParent();
15074 assert(ClassDecl && "DefineImplicitMoveConstructor - invalid constructor")((void)0);
15075
15076 SynthesizedFunctionScope Scope(*this, MoveConstructor);
15077
15078 // The exception specification is needed because we are defining the
15079 // function.
15080 ResolveExceptionSpec(CurrentLocation,
15081 MoveConstructor->getType()->castAs<FunctionProtoType>());
15082 MarkVTableUsed(CurrentLocation, ClassDecl);
15083
15084 // Add a context note for diagnostics produced after this point.
15085 Scope.addContextNote(CurrentLocation);
15086
15087 if (SetCtorInitializers(MoveConstructor, /*AnyErrors=*/false)) {
15088 MoveConstructor->setInvalidDecl();
15089 } else {
15090 SourceLocation Loc = MoveConstructor->getEndLoc().isValid()
15091 ? MoveConstructor->getEndLoc()
15092 : MoveConstructor->getLocation();
15093 Sema::CompoundScopeRAII CompoundScope(*this);
15094 MoveConstructor->setBody(ActOnCompoundStmt(
15095 Loc, Loc, None, /*isStmtExpr=*/ false).getAs<Stmt>());
15096 MoveConstructor->markUsed(Context);
15097 }
15098
15099 if (ASTMutationListener *L = getASTMutationListener()) {
15100 L->CompletedImplicitDefinition(MoveConstructor);
15101 }
15102}
15103
15104bool Sema::isImplicitlyDeleted(FunctionDecl *FD) {
15105 return FD->isDeleted() && FD->isDefaulted() && isa<CXXMethodDecl>(FD);
15106}
15107
15108void Sema::DefineImplicitLambdaToFunctionPointerConversion(
15109 SourceLocation CurrentLocation,
15110 CXXConversionDecl *Conv) {
15111 SynthesizedFunctionScope Scope(*this, Conv);
15112 assert(!Conv->getReturnType()->isUndeducedType())((void)0);
15113
15114 QualType ConvRT = Conv->getType()->castAs<FunctionType>()->getReturnType();
15115 CallingConv CC =
15116 ConvRT->getPointeeType()->castAs<FunctionType>()->getCallConv();
15117
15118 CXXRecordDecl *Lambda = Conv->getParent();
15119 FunctionDecl *CallOp = Lambda->getLambdaCallOperator();
15120 FunctionDecl *Invoker = Lambda->getLambdaStaticInvoker(CC);
15121
15122 if (auto *TemplateArgs = Conv->getTemplateSpecializationArgs()) {
15123 CallOp = InstantiateFunctionDeclaration(
15124 CallOp->getDescribedFunctionTemplate(), TemplateArgs, CurrentLocation);
15125 if (!CallOp)
15126 return;
15127
15128 Invoker = InstantiateFunctionDeclaration(
15129 Invoker->getDescribedFunctionTemplate(), TemplateArgs, CurrentLocation);
15130 if (!Invoker)
15131 return;
15132 }
15133
15134 if (CallOp->isInvalidDecl())
15135 return;
15136
15137 // Mark the call operator referenced (and add to pending instantiations
15138 // if necessary).
15139 // For both the conversion and static-invoker template specializations
15140 // we construct their body's in this function, so no need to add them
15141 // to the PendingInstantiations.
15142 MarkFunctionReferenced(CurrentLocation, CallOp);
15143
15144 // Fill in the __invoke function with a dummy implementation. IR generation
15145 // will fill in the actual details. Update its type in case it contained
15146 // an 'auto'.
15147 Invoker->markUsed(Context);
15148 Invoker->setReferenced();
15149 Invoker->setType(Conv->getReturnType()->getPointeeType());
15150 Invoker->setBody(new (Context) CompoundStmt(Conv->getLocation()));
15151
15152 // Construct the body of the conversion function { return __invoke; }.
15153 Expr *FunctionRef = BuildDeclRefExpr(Invoker, Invoker->getType(),
15154 VK_LValue, Conv->getLocation());
15155 assert(FunctionRef && "Can't refer to __invoke function?")((void)0);
15156 Stmt *Return = BuildReturnStmt(Conv->getLocation(), FunctionRef).get();
15157 Conv->setBody(CompoundStmt::Create(Context, Return, Conv->getLocation(),
15158 Conv->getLocation()));
15159 Conv->markUsed(Context);
15160 Conv->setReferenced();
15161
15162 if (ASTMutationListener *L = getASTMutationListener()) {
15163 L->CompletedImplicitDefinition(Conv);
15164 L->CompletedImplicitDefinition(Invoker);
15165 }
15166}
15167
15168
15169
15170void Sema::DefineImplicitLambdaToBlockPointerConversion(
15171 SourceLocation CurrentLocation,
15172 CXXConversionDecl *Conv)
15173{
15174 assert(!Conv->getParent()->isGenericLambda())((void)0);
15175
15176 SynthesizedFunctionScope Scope(*this, Conv);
15177
15178 // Copy-initialize the lambda object as needed to capture it.
15179 Expr *This = ActOnCXXThis(CurrentLocation).get();
15180 Expr *DerefThis =CreateBuiltinUnaryOp(CurrentLocation, UO_Deref, This).get();
15181
15182 ExprResult BuildBlock = BuildBlockForLambdaConversion(CurrentLocation,
15183 Conv->getLocation(),
15184 Conv, DerefThis);
15185
15186 // If we're not under ARC, make sure we still get the _Block_copy/autorelease
15187 // behavior. Note that only the general conversion function does this
15188 // (since it's unusable otherwise); in the case where we inline the
15189 // block literal, it has block literal lifetime semantics.
15190 if (!BuildBlock.isInvalid() && !getLangOpts().ObjCAutoRefCount)
15191 BuildBlock = ImplicitCastExpr::Create(
15192 Context, BuildBlock.get()->getType(), CK_CopyAndAutoreleaseBlockObject,
15193 BuildBlock.get(), nullptr, VK_PRValue, FPOptionsOverride());
15194
15195 if (BuildBlock.isInvalid()) {
15196 Diag(CurrentLocation, diag::note_lambda_to_block_conv);
15197 Conv->setInvalidDecl();
15198 return;
15199 }
15200
15201 // Create the return statement that returns the block from the conversion
15202 // function.
15203 StmtResult Return = BuildReturnStmt(Conv->getLocation(), BuildBlock.get());
15204 if (Return.isInvalid()) {
15205 Diag(CurrentLocation, diag::note_lambda_to_block_conv);
15206 Conv->setInvalidDecl();
15207 return;
15208 }
15209
15210 // Set the body of the conversion function.
15211 Stmt *ReturnS = Return.get();
15212 Conv->setBody(CompoundStmt::Create(Context, ReturnS, Conv->getLocation(),
15213 Conv->getLocation()));
15214 Conv->markUsed(Context);
15215
15216 // We're done; notify the mutation listener, if any.
15217 if (ASTMutationListener *L = getASTMutationListener()) {
15218 L->CompletedImplicitDefinition(Conv);
15219 }
15220}
15221
15222/// Determine whether the given list arguments contains exactly one
15223/// "real" (non-default) argument.
15224static bool hasOneRealArgument(MultiExprArg Args) {
15225 switch (Args.size()) {
15226 case 0:
15227 return false;
15228
15229 default:
15230 if (!Args[1]->isDefaultArgument())
15231 return false;
15232
15233 LLVM_FALLTHROUGH[[gnu::fallthrough]];
15234 case 1:
15235 return !Args[0]->isDefaultArgument();
15236 }
15237
15238 return false;
15239}
15240
15241ExprResult
15242Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
15243 NamedDecl *FoundDecl,
15244 CXXConstructorDecl *Constructor,
15245 MultiExprArg ExprArgs,
15246 bool HadMultipleCandidates,
15247 bool IsListInitialization,
15248 bool IsStdInitListInitialization,
15249 bool RequiresZeroInit,
15250 unsigned ConstructKind,
15251 SourceRange ParenRange) {
15252 bool Elidable = false;
15253
15254 // C++0x [class.copy]p34:
15255 // When certain criteria are met, an implementation is allowed to
15256 // omit the copy/move construction of a class object, even if the
15257 // copy/move constructor and/or destructor for the object have
15258 // side effects. [...]
15259 // - when a temporary class object that has not been bound to a
15260 // reference (12.2) would be copied/moved to a class object
15261 // with the same cv-unqualified type, the copy/move operation
15262 // can be omitted by constructing the temporary object
15263 // directly into the target of the omitted copy/move
15264 if (ConstructKind == CXXConstructExpr::CK_Complete && Constructor &&
15265 // FIXME: Converting constructors should also be accepted.
15266 // But to fix this, the logic that digs down into a CXXConstructExpr
15267 // to find the source object needs to handle it.
15268 // Right now it assumes the source object is passed directly as the
15269 // first argument.
15270 Constructor->isCopyOrMoveConstructor() && hasOneRealArgument(ExprArgs)) {
15271 Expr *SubExpr = ExprArgs[0];
15272 // FIXME: Per above, this is also incorrect if we want to accept
15273 // converting constructors, as isTemporaryObject will
15274 // reject temporaries with different type from the
15275 // CXXRecord itself.
15276 Elidable = SubExpr->isTemporaryObject(
15277 Context, cast<CXXRecordDecl>(FoundDecl->getDeclContext()));
15278 }
15279
15280 return BuildCXXConstructExpr(ConstructLoc, DeclInitType,
15281 FoundDecl, Constructor,
15282 Elidable, ExprArgs, HadMultipleCandidates,
15283 IsListInitialization,
15284 IsStdInitListInitialization, RequiresZeroInit,
15285 ConstructKind, ParenRange);
15286}
15287
15288ExprResult
15289Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
15290 NamedDecl *FoundDecl,
15291 CXXConstructorDecl *Constructor,
15292 bool Elidable,
15293 MultiExprArg ExprArgs,
15294 bool HadMultipleCandidates,
15295 bool IsListInitialization,
15296 bool IsStdInitListInitialization,
15297 bool RequiresZeroInit,
15298 unsigned ConstructKind,
15299 SourceRange ParenRange) {
15300 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl)) {
15301 Constructor = findInheritingConstructor(ConstructLoc, Constructor, Shadow);
15302 if (DiagnoseUseOfDecl(Constructor, ConstructLoc))
15303 return ExprError();
15304 }
15305
15306 return BuildCXXConstructExpr(
15307 ConstructLoc, DeclInitType, Constructor, Elidable, ExprArgs,
15308 HadMultipleCandidates, IsListInitialization, IsStdInitListInitialization,
15309 RequiresZeroInit, ConstructKind, ParenRange);
15310}
15311
15312/// BuildCXXConstructExpr - Creates a complete call to a constructor,
15313/// including handling of its default argument expressions.
15314ExprResult
15315Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
15316 CXXConstructorDecl *Constructor,
15317 bool Elidable,
15318 MultiExprArg ExprArgs,
15319 bool HadMultipleCandidates,
15320 bool IsListInitialization,
15321 bool IsStdInitListInitialization,
15322 bool RequiresZeroInit,
15323 unsigned ConstructKind,
15324 SourceRange ParenRange) {
15325 assert(declaresSameEntity(((void)0)
15326 Constructor->getParent(),((void)0)
15327 DeclInitType->getBaseElementTypeUnsafe()->getAsCXXRecordDecl()) &&((void)0)
15328 "given constructor for wrong type")((void)0);
15329 MarkFunctionReferenced(ConstructLoc, Constructor);
15330 if (getLangOpts().CUDA && !CheckCUDACall(ConstructLoc, Constructor))
15331 return ExprError();
15332 if (getLangOpts().SYCLIsDevice &&
15333 !checkSYCLDeviceFunction(ConstructLoc, Constructor))
15334 return ExprError();
15335
15336 return CheckForImmediateInvocation(
15337 CXXConstructExpr::Create(
15338 Context, DeclInitType, ConstructLoc, Constructor, Elidable, ExprArgs,
15339 HadMultipleCandidates, IsListInitialization,
15340 IsStdInitListInitialization, RequiresZeroInit,
15341 static_cast<CXXConstructExpr::ConstructionKind>(ConstructKind),
15342 ParenRange),
15343 Constructor);
15344}
15345
15346ExprResult Sema::BuildCXXDefaultInitExpr(SourceLocation Loc, FieldDecl *Field) {
15347 assert(Field->hasInClassInitializer())((void)0);
15348
15349 // If we already have the in-class initializer nothing needs to be done.
15350 if (Field->getInClassInitializer())
15351 return CXXDefaultInitExpr::Create(Context, Loc, Field, CurContext);
15352
15353 // If we might have already tried and failed to instantiate, don't try again.
15354 if (Field->isInvalidDecl())
15355 return ExprError();
15356
15357 // Maybe we haven't instantiated the in-class initializer. Go check the
15358 // pattern FieldDecl to see if it has one.
15359 CXXRecordDecl *ParentRD = cast<CXXRecordDecl>(Field->getParent());
15360
15361 if (isTemplateInstantiation(ParentRD->getTemplateSpecializationKind())) {
15362 CXXRecordDecl *ClassPattern = ParentRD->getTemplateInstantiationPattern();
15363 DeclContext::lookup_result Lookup =
15364 ClassPattern->lookup(Field->getDeclName());
15365
15366 FieldDecl *Pattern = nullptr;
15367 for (auto L : Lookup) {
15368 if (isa<FieldDecl>(L)) {
15369 Pattern = cast<FieldDecl>(L);
15370 break;
15371 }
15372 }
15373 assert(Pattern && "We must have set the Pattern!")((void)0);
15374
15375 if (!Pattern->hasInClassInitializer() ||
15376 InstantiateInClassInitializer(Loc, Field, Pattern,
15377 getTemplateInstantiationArgs(Field))) {
15378 // Don't diagnose this again.
15379 Field->setInvalidDecl();
15380 return ExprError();
15381 }
15382 return CXXDefaultInitExpr::Create(Context, Loc, Field, CurContext);
15383 }
15384
15385 // DR1351:
15386 // If the brace-or-equal-initializer of a non-static data member
15387 // invokes a defaulted default constructor of its class or of an
15388 // enclosing class in a potentially evaluated subexpression, the
15389 // program is ill-formed.
15390 //
15391 // This resolution is unworkable: the exception specification of the
15392 // default constructor can be needed in an unevaluated context, in
15393 // particular, in the operand of a noexcept-expression, and we can be
15394 // unable to compute an exception specification for an enclosed class.
15395 //
15396 // Any attempt to resolve the exception specification of a defaulted default
15397 // constructor before the initializer is lexically complete will ultimately
15398 // come here at which point we can diagnose it.
15399 RecordDecl *OutermostClass = ParentRD->getOuterLexicalRecordContext();
15400 Diag(Loc, diag::err_default_member_initializer_not_yet_parsed)
15401 << OutermostClass << Field;
15402 Diag(Field->getEndLoc(),
15403 diag::note_default_member_initializer_not_yet_parsed);
15404 // Recover by marking the field invalid, unless we're in a SFINAE context.
15405 if (!isSFINAEContext())
15406 Field->setInvalidDecl();
15407 return ExprError();
15408}
15409
15410void Sema::FinalizeVarWithDestructor(VarDecl *VD, const RecordType *Record) {
15411 if (VD->isInvalidDecl()) return;
15412 // If initializing the variable failed, don't also diagnose problems with
15413 // the desctructor, they're likely related.
15414 if (VD->getInit() && VD->getInit()->containsErrors())
15415 return;
15416
15417 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Record->getDecl());
15418 if (ClassDecl->isInvalidDecl()) return;
15419 if (ClassDecl->hasIrrelevantDestructor()) return;
15420 if (ClassDecl->isDependentContext()) return;
15421
15422 if (VD->isNoDestroy(getASTContext()))
15423 return;
15424
15425 CXXDestructorDecl *Destructor = LookupDestructor(ClassDecl);
15426
15427 // If this is an array, we'll require the destructor during initialization, so
15428 // we can skip over this. We still want to emit exit-time destructor warnings
15429 // though.
15430 if (!VD->getType()->isArrayType()) {
15431 MarkFunctionReferenced(VD->getLocation(), Destructor);
15432 CheckDestructorAccess(VD->getLocation(), Destructor,
15433 PDiag(diag::err_access_dtor_var)
15434 << VD->getDeclName() << VD->getType());
15435 DiagnoseUseOfDecl(Destructor, VD->getLocation());
15436 }
15437
15438 if (Destructor->isTrivial()) return;
15439
15440 // If the destructor is constexpr, check whether the variable has constant
15441 // destruction now.
15442 if (Destructor->isConstexpr()) {
15443 bool HasConstantInit = false;
15444 if (VD->getInit() && !VD->getInit()->isValueDependent())
15445 HasConstantInit = VD->evaluateValue();
15446 SmallVector<PartialDiagnosticAt, 8> Notes;
15447 if (!VD->evaluateDestruction(Notes) && VD->isConstexpr() &&
15448 HasConstantInit) {
15449 Diag(VD->getLocation(),
15450 diag::err_constexpr_var_requires_const_destruction) << VD;
15451 for (unsigned I = 0, N = Notes.size(); I != N; ++I)
15452 Diag(Notes[I].first, Notes[I].second);
15453 }
15454 }
15455
15456 if (!VD->hasGlobalStorage()) return;
15457
15458 // Emit warning for non-trivial dtor in global scope (a real global,
15459 // class-static, function-static).
15460 Diag(VD->getLocation(), diag::warn_exit_time_destructor);
15461
15462 // TODO: this should be re-enabled for static locals by !CXAAtExit
15463 if (!VD->isStaticLocal())
15464 Diag(VD->getLocation(), diag::warn_global_destructor);
15465}
15466
15467/// Given a constructor and the set of arguments provided for the
15468/// constructor, convert the arguments and add any required default arguments
15469/// to form a proper call to this constructor.
15470///
15471/// \returns true if an error occurred, false otherwise.
15472bool Sema::CompleteConstructorCall(CXXConstructorDecl *Constructor,
15473 QualType DeclInitType, MultiExprArg ArgsPtr,
15474 SourceLocation Loc,
15475 SmallVectorImpl<Expr *> &ConvertedArgs,
15476 bool AllowExplicit,
15477 bool IsListInitialization) {
15478 // FIXME: This duplicates a lot of code from Sema::ConvertArgumentsForCall.
15479 unsigned NumArgs = ArgsPtr.size();
15480 Expr **Args = ArgsPtr.data();
15481
15482 const auto *Proto = Constructor->getType()->castAs<FunctionProtoType>();
15483 unsigned NumParams = Proto->getNumParams();
15484
15485 // If too few arguments are available, we'll fill in the rest with defaults.
15486 if (NumArgs < NumParams)
15487 ConvertedArgs.reserve(NumParams);
15488 else
15489 ConvertedArgs.reserve(NumArgs);
15490
15491 VariadicCallType CallType =
15492 Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
15493 SmallVector<Expr *, 8> AllArgs;
15494 bool Invalid = GatherArgumentsForCall(Loc, Constructor,
15495 Proto, 0,
15496 llvm::makeArrayRef(Args, NumArgs),
15497 AllArgs,
15498 CallType, AllowExplicit,
15499 IsListInitialization);
15500 ConvertedArgs.append(AllArgs.begin(), AllArgs.end());
15501
15502 DiagnoseSentinelCalls(Constructor, Loc, AllArgs);
15503
15504 CheckConstructorCall(Constructor, DeclInitType,
15505 llvm::makeArrayRef(AllArgs.data(), AllArgs.size()),
15506 Proto, Loc);
15507
15508 return Invalid;
15509}
15510
15511static inline bool
15512CheckOperatorNewDeleteDeclarationScope(Sema &SemaRef,
15513 const FunctionDecl *FnDecl) {
15514 const DeclContext *DC = FnDecl->getDeclContext()->getRedeclContext();
15515 if (isa<NamespaceDecl>(DC)) {
15516 return SemaRef.Diag(FnDecl->getLocation(),
15517 diag::err_operator_new_delete_declared_in_namespace)
15518 << FnDecl->getDeclName();
15519 }
15520
15521 if (isa<TranslationUnitDecl>(DC) &&
15522 FnDecl->getStorageClass() == SC_Static) {
15523 return SemaRef.Diag(FnDecl->getLocation(),
15524 diag::err_operator_new_delete_declared_static)
15525 << FnDecl->getDeclName();
15526 }
15527
15528 return false;
15529}
15530
15531static CanQualType RemoveAddressSpaceFromPtr(Sema &SemaRef,
15532 const PointerType *PtrTy) {
15533 auto &Ctx = SemaRef.Context;
15534 Qualifiers PtrQuals = PtrTy->getPointeeType().getQualifiers();
15535 PtrQuals.removeAddressSpace();
15536 return Ctx.getPointerType(Ctx.getCanonicalType(Ctx.getQualifiedType(
15537 PtrTy->getPointeeType().getUnqualifiedType(), PtrQuals)));
15538}
15539
15540static inline bool
15541CheckOperatorNewDeleteTypes(Sema &SemaRef, const FunctionDecl *FnDecl,
15542 CanQualType ExpectedResultType,
15543 CanQualType ExpectedFirstParamType,
15544 unsigned DependentParamTypeDiag,
15545 unsigned InvalidParamTypeDiag) {
15546 QualType ResultType =
15547 FnDecl->getType()->castAs<FunctionType>()->getReturnType();
15548
15549 if (SemaRef.getLangOpts().OpenCLCPlusPlus) {
15550 // The operator is valid on any address space for OpenCL.
15551 // Drop address space from actual and expected result types.
15552 if (const auto *PtrTy = ResultType->getAs<PointerType>())
15553 ResultType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy);
15554
15555 if (auto ExpectedPtrTy = ExpectedResultType->getAs<PointerType>())
15556 ExpectedResultType = RemoveAddressSpaceFromPtr(SemaRef, ExpectedPtrTy);
15557 }
15558
15559 // Check that the result type is what we expect.
15560 if (SemaRef.Context.getCanonicalType(ResultType) != ExpectedResultType) {
15561 // Reject even if the type is dependent; an operator delete function is
15562 // required to have a non-dependent result type.
15563 return SemaRef.Diag(
15564 FnDecl->getLocation(),
15565 ResultType->isDependentType()
15566 ? diag::err_operator_new_delete_dependent_result_type
15567 : diag::err_operator_new_delete_invalid_result_type)
15568 << FnDecl->getDeclName() << ExpectedResultType;
15569 }
15570
15571 // A function template must have at least 2 parameters.
15572 if (FnDecl->getDescribedFunctionTemplate() && FnDecl->getNumParams() < 2)
15573 return SemaRef.Diag(FnDecl->getLocation(),
15574 diag::err_operator_new_delete_template_too_few_parameters)
15575 << FnDecl->getDeclName();
15576
15577 // The function decl must have at least 1 parameter.
15578 if (FnDecl->getNumParams() == 0)
15579 return SemaRef.Diag(FnDecl->getLocation(),
15580 diag::err_operator_new_delete_too_few_parameters)
15581 << FnDecl->getDeclName();
15582
15583 QualType FirstParamType = FnDecl->getParamDecl(0)->getType();
15584 if (SemaRef.getLangOpts().OpenCLCPlusPlus) {
15585 // The operator is valid on any address space for OpenCL.
15586 // Drop address space from actual and expected first parameter types.
15587 if (const auto *PtrTy =
15588 FnDecl->getParamDecl(0)->getType()->getAs<PointerType>())
15589 FirstParamType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy);
15590
15591 if (auto ExpectedPtrTy = ExpectedFirstParamType->getAs<PointerType>())
15592 ExpectedFirstParamType =
15593 RemoveAddressSpaceFromPtr(SemaRef, ExpectedPtrTy);
15594 }
15595
15596 // Check that the first parameter type is what we expect.
15597 if (SemaRef.Context.getCanonicalType(FirstParamType).getUnqualifiedType() !=
15598 ExpectedFirstParamType) {
15599 // The first parameter type is not allowed to be dependent. As a tentative
15600 // DR resolution, we allow a dependent parameter type if it is the right
15601 // type anyway, to allow destroying operator delete in class templates.
15602 return SemaRef.Diag(FnDecl->getLocation(), FirstParamType->isDependentType()
15603 ? DependentParamTypeDiag
15604 : InvalidParamTypeDiag)
15605 << FnDecl->getDeclName() << ExpectedFirstParamType;
15606 }
15607
15608 return false;
15609}
15610
15611static bool
15612CheckOperatorNewDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
15613 // C++ [basic.stc.dynamic.allocation]p1:
15614 // A program is ill-formed if an allocation function is declared in a
15615 // namespace scope other than global scope or declared static in global
15616 // scope.
15617 if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
15618 return true;
15619
15620 CanQualType SizeTy =
15621 SemaRef.Context.getCanonicalType(SemaRef.Context.getSizeType());
15622
15623 // C++ [basic.stc.dynamic.allocation]p1:
15624 // The return type shall be void*. The first parameter shall have type
15625 // std::size_t.
15626 if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidPtrTy,
15627 SizeTy,
15628 diag::err_operator_new_dependent_param_type,
15629 diag::err_operator_new_param_type))
15630 return true;
15631
15632 // C++ [basic.stc.dynamic.allocation]p1:
15633 // The first parameter shall not have an associated default argument.
15634 if (FnDecl->getParamDecl(0)->hasDefaultArg())
15635 return SemaRef.Diag(FnDecl->getLocation(),
15636 diag::err_operator_new_default_arg)
15637 << FnDecl->getDeclName() << FnDecl->getParamDecl(0)->getDefaultArgRange();
15638
15639 return false;
15640}
15641
15642static bool
15643CheckOperatorDeleteDeclaration(Sema &SemaRef, FunctionDecl *FnDecl) {
15644 // C++ [basic.stc.dynamic.deallocation]p1:
15645 // A program is ill-formed if deallocation functions are declared in a
15646 // namespace scope other than global scope or declared static in global
15647 // scope.
15648 if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
15649 return true;
15650
15651 auto *MD = dyn_cast<CXXMethodDecl>(FnDecl);
15652
15653 // C++ P0722:
15654 // Within a class C, the first parameter of a destroying operator delete
15655 // shall be of type C *. The first parameter of any other deallocation
15656 // function shall be of type void *.
15657 CanQualType ExpectedFirstParamType =
15658 MD && MD->isDestroyingOperatorDelete()
15659 ? SemaRef.Context.getCanonicalType(SemaRef.Context.getPointerType(
15660 SemaRef.Context.getRecordType(MD->getParent())))
15661 : SemaRef.Context.VoidPtrTy;
15662
15663 // C++ [basic.stc.dynamic.deallocation]p2:
15664 // Each deallocation function shall return void
15665 if (CheckOperatorNewDeleteTypes(
15666 SemaRef, FnDecl, SemaRef.Context.VoidTy, ExpectedFirstParamType,
15667 diag::err_operator_delete_dependent_param_type,
15668 diag::err_operator_delete_param_type))
15669 return true;
15670
15671 // C++ P0722:
15672 // A destroying operator delete shall be a usual deallocation function.
15673 if (MD && !MD->getParent()->isDependentContext() &&
15674 MD->isDestroyingOperatorDelete() &&
15675 !SemaRef.isUsualDeallocationFunction(MD)) {
15676 SemaRef.Diag(MD->getLocation(),
15677 diag::err_destroying_operator_delete_not_usual);
15678 return true;
15679 }
15680
15681 return false;
15682}
15683
15684/// CheckOverloadedOperatorDeclaration - Check whether the declaration
15685/// of this overloaded operator is well-formed. If so, returns false;
15686/// otherwise, emits appropriate diagnostics and returns true.
15687bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
15688 assert(FnDecl && FnDecl->isOverloadedOperator() &&((void)0)
15689 "Expected an overloaded operator declaration")((void)0);
15690
15691 OverloadedOperatorKind Op = FnDecl->getOverloadedOperator();
15692
15693 // C++ [over.oper]p5:
15694 // The allocation and deallocation functions, operator new,
15695 // operator new[], operator delete and operator delete[], are
15696 // described completely in 3.7.3. The attributes and restrictions
15697 // found in the rest of this subclause do not apply to them unless
15698 // explicitly stated in 3.7.3.
15699 if (Op == OO_Delete || Op == OO_Array_Delete)
15700 return CheckOperatorDeleteDeclaration(*this, FnDecl);
15701
15702 if (Op == OO_New || Op == OO_Array_New)
15703 return CheckOperatorNewDeclaration(*this, FnDecl);
15704
15705 // C++ [over.oper]p6:
15706 // An operator function shall either be a non-static member
15707 // function or be a non-member function and have at least one
15708 // parameter whose type is a class, a reference to a class, an
15709 // enumeration, or a reference to an enumeration.
15710 if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) {
15711 if (MethodDecl->isStatic())
15712 return Diag(FnDecl->getLocation(),
15713 diag::err_operator_overload_static) << FnDecl->getDeclName();
15714 } else {
15715 bool ClassOrEnumParam = false;
15716 for (auto Param : FnDecl->parameters()) {
15717 QualType ParamType = Param->getType().getNonReferenceType();
15718 if (ParamType->isDependentType() || ParamType->isRecordType() ||
15719 ParamType->isEnumeralType()) {
15720 ClassOrEnumParam = true;
15721 break;
15722 }
15723 }
15724
15725 if (!ClassOrEnumParam)
15726 return Diag(FnDecl->getLocation(),
15727 diag::err_operator_overload_needs_class_or_enum)
15728 << FnDecl->getDeclName();
15729 }
15730
15731 // C++ [over.oper]p8:
15732 // An operator function cannot have default arguments (8.3.6),
15733 // except where explicitly stated below.
15734 //
15735 // Only the function-call operator allows default arguments
15736 // (C++ [over.call]p1).
15737 if (Op != OO_Call) {
15738 for (auto Param : FnDecl->parameters()) {
15739 if (Param->hasDefaultArg())
15740 return Diag(Param->getLocation(),
15741 diag::err_operator_overload_default_arg)
15742 << FnDecl->getDeclName() << Param->getDefaultArgRange();
15743 }
15744 }
15745
15746 static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = {
15747 { false, false, false }
15748#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
15749 , { Unary, Binary, MemberOnly }
15750#include "clang/Basic/OperatorKinds.def"
15751 };
15752
15753 bool CanBeUnaryOperator = OperatorUses[Op][0];
15754 bool CanBeBinaryOperator = OperatorUses[Op][1];
15755 bool MustBeMemberOperator = OperatorUses[Op][2];
15756
15757 // C++ [over.oper]p8:
15758 // [...] Operator functions cannot have more or fewer parameters
15759 // than the number required for the corresponding operator, as
15760 // described in the rest of this subclause.
15761 unsigned NumParams = FnDecl->getNumParams()
15762 + (isa<CXXMethodDecl>(FnDecl)? 1 : 0);
15763 if (Op != OO_Call &&
15764 ((NumParams == 1 && !CanBeUnaryOperator) ||
15765 (NumParams == 2 && !CanBeBinaryOperator) ||
15766 (NumParams < 1) || (NumParams > 2))) {
15767 // We have the wrong number of parameters.
15768 unsigned ErrorKind;
15769 if (CanBeUnaryOperator && CanBeBinaryOperator) {
15770 ErrorKind = 2; // 2 -> unary or binary.
15771 } else if (CanBeUnaryOperator) {
15772 ErrorKind = 0; // 0 -> unary
15773 } else {
15774 assert(CanBeBinaryOperator &&((void)0)
15775 "All non-call overloaded operators are unary or binary!")((void)0);
15776 ErrorKind = 1; // 1 -> binary
15777 }
15778
15779 return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be)
15780 << FnDecl->getDeclName() << NumParams << ErrorKind;
15781 }
15782
15783 // Overloaded operators other than operator() cannot be variadic.
15784 if (Op != OO_Call &&
15785 FnDecl->getType()->castAs<FunctionProtoType>()->isVariadic()) {
15786 return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic)
15787 << FnDecl->getDeclName();
15788 }
15789
15790 // Some operators must be non-static member functions.
15791 if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) {
15792 return Diag(FnDecl->getLocation(),
15793 diag::err_operator_overload_must_be_member)
15794 << FnDecl->getDeclName();
15795 }
15796
15797 // C++ [over.inc]p1:
15798 // The user-defined function called operator++ implements the
15799 // prefix and postfix ++ operator. If this function is a member
15800 // function with no parameters, or a non-member function with one
15801 // parameter of class or enumeration type, it defines the prefix
15802 // increment operator ++ for objects of that type. If the function
15803 // is a member function with one parameter (which shall be of type
15804 // int) or a non-member function with two parameters (the second
15805 // of which shall be of type int), it defines the postfix
15806 // increment operator ++ for objects of that type.
15807 if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) {
15808 ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1);
15809 QualType ParamType = LastParam->getType();
15810
15811 if (!ParamType->isSpecificBuiltinType(BuiltinType::Int) &&
15812 !ParamType->isDependentType())
15813 return Diag(LastParam->getLocation(),
15814 diag::err_operator_overload_post_incdec_must_be_int)
15815 << LastParam->getType() << (Op == OO_MinusMinus);
15816 }
15817
15818 return false;
15819}
15820
15821static bool
15822checkLiteralOperatorTemplateParameterList(Sema &SemaRef,
15823 FunctionTemplateDecl *TpDecl) {
15824 TemplateParameterList *TemplateParams = TpDecl->getTemplateParameters();
15825
15826 // Must have one or two template parameters.
15827 if (TemplateParams->size() == 1) {
15828 NonTypeTemplateParmDecl *PmDecl =
15829 dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(0));
15830
15831 // The template parameter must be a char parameter pack.
15832 if (PmDecl && PmDecl->isTemplateParameterPack() &&
15833 SemaRef.Context.hasSameType(PmDecl->getType(), SemaRef.Context.CharTy))
15834 return false;
15835
15836 // C++20 [over.literal]p5:
15837 // A string literal operator template is a literal operator template
15838 // whose template-parameter-list comprises a single non-type
15839 // template-parameter of class type.
15840 //
15841 // As a DR resolution, we also allow placeholders for deduced class
15842 // template specializations.
15843 if (SemaRef.getLangOpts().CPlusPlus20 &&
15844 !PmDecl->isTemplateParameterPack() &&
15845 (PmDecl->getType()->isRecordType() ||
15846 PmDecl->getType()->getAs<DeducedTemplateSpecializationType>()))
15847 return false;
15848 } else if (TemplateParams->size() == 2) {
15849 TemplateTypeParmDecl *PmType =
15850 dyn_cast<TemplateTypeParmDecl>(TemplateParams->getParam(0));
15851 NonTypeTemplateParmDecl *PmArgs =
15852 dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(1));
15853
15854 // The second template parameter must be a parameter pack with the
15855 // first template parameter as its type.
15856 if (PmType && PmArgs && !PmType->isTemplateParameterPack() &&
15857 PmArgs->isTemplateParameterPack()) {
15858 const TemplateTypeParmType *TArgs =
15859 PmArgs->getType()->getAs<TemplateTypeParmType>();
15860 if (TArgs && TArgs->getDepth() == PmType->getDepth() &&
15861 TArgs->getIndex() == PmType->getIndex()) {
15862 if (!SemaRef.inTemplateInstantiation())
15863 SemaRef.Diag(TpDecl->getLocation(),
15864 diag::ext_string_literal_operator_template);
15865 return false;
15866 }
15867 }
15868 }
15869
15870 SemaRef.Diag(TpDecl->getTemplateParameters()->getSourceRange().getBegin(),
15871 diag::err_literal_operator_template)
15872 << TpDecl->getTemplateParameters()->getSourceRange();
15873 return true;
15874}
15875
15876/// CheckLiteralOperatorDeclaration - Check whether the declaration
15877/// of this literal operator function is well-formed. If so, returns
15878/// false; otherwise, emits appropriate diagnostics and returns true.
15879bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) {
15880 if (isa<CXXMethodDecl>(FnDecl)) {
15881 Diag(FnDecl->getLocation(), diag::err_literal_operator_outside_namespace)
15882 << FnDecl->getDeclName();
15883 return true;
15884 }
15885
15886 if (FnDecl->isExternC()) {
15887 Diag(FnDecl->getLocation(), diag::err_literal_operator_extern_c);
15888 if (const LinkageSpecDecl *LSD =
15889 FnDecl->getDeclContext()->getExternCContext())
15890 Diag(LSD->getExternLoc(), diag::note_extern_c_begins_here);
15891 return true;
15892 }
15893
15894 // This might be the definition of a literal operator template.
15895 FunctionTemplateDecl *TpDecl = FnDecl->getDescribedFunctionTemplate();
15896
15897 // This might be a specialization of a literal operator template.
15898 if (!TpDecl)
15899 TpDecl = FnDecl->getPrimaryTemplate();
15900
15901 // template <char...> type operator "" name() and
15902 // template <class T, T...> type operator "" name() are the only valid
15903 // template signatures, and the only valid signatures with no parameters.
15904 //
15905 // C++20 also allows template <SomeClass T> type operator "" name().
15906 if (TpDecl) {
15907 if (FnDecl->param_size() != 0) {
15908 Diag(FnDecl->getLocation(),
15909 diag::err_literal_operator_template_with_params);
15910 return true;
15911 }
15912
15913 if (checkLiteralOperatorTemplateParameterList(*this, TpDecl))
15914 return true;
15915
15916 } else if (FnDecl->param_size() == 1) {
15917 const ParmVarDecl *Param = FnDecl->getParamDecl(0);
15918
15919 QualType ParamType = Param->getType().getUnqualifiedType();
15920
15921 // Only unsigned long long int, long double, any character type, and const
15922 // char * are allowed as the only parameters.
15923 if (ParamType->isSpecificBuiltinType(BuiltinType::ULongLong) ||
15924 ParamType->isSpecificBuiltinType(BuiltinType::LongDouble) ||
15925 Context.hasSameType(ParamType, Context.CharTy) ||
15926 Context.hasSameType(ParamType, Context.WideCharTy) ||
15927 Context.hasSameType(ParamType, Context.Char8Ty) ||
15928 Context.hasSameType(ParamType, Context.Char16Ty) ||
15929 Context.hasSameType(ParamType, Context.Char32Ty)) {
15930 } else if (const PointerType *Ptr = ParamType->getAs<PointerType>()) {
15931 QualType InnerType = Ptr->getPointeeType();
15932
15933 // Pointer parameter must be a const char *.
15934 if (!(Context.hasSameType(InnerType.getUnqualifiedType(),
15935 Context.CharTy) &&
15936 InnerType.isConstQualified() && !InnerType.isVolatileQualified())) {
15937 Diag(Param->getSourceRange().getBegin(),
15938 diag::err_literal_operator_param)
15939 << ParamType << "'const char *'" << Param->getSourceRange();
15940 return true;
15941 }
15942
15943 } else if (ParamType->isRealFloatingType()) {
15944 Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param)
15945 << ParamType << Context.LongDoubleTy << Param->getSourceRange();
15946 return true;
15947
15948 } else if (ParamType->isIntegerType()) {
15949 Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param)
15950 << ParamType << Context.UnsignedLongLongTy << Param->getSourceRange();
15951 return true;
15952
15953 } else {
15954 Diag(Param->getSourceRange().getBegin(),
15955 diag::err_literal_operator_invalid_param)
15956 << ParamType << Param->getSourceRange();
15957 return true;
15958 }
15959
15960 } else if (FnDecl->param_size() == 2) {
15961 FunctionDecl::param_iterator Param = FnDecl->param_begin();
15962
15963 // First, verify that the first parameter is correct.
15964
15965 QualType FirstParamType = (*Param)->getType().getUnqualifiedType();
15966
15967 // Two parameter function must have a pointer to const as a
15968 // first parameter; let's strip those qualifiers.
15969 const PointerType *PT = FirstParamType->getAs<PointerType>();
15970
15971 if (!PT) {
15972 Diag((*Param)->getSourceRange().getBegin(),
15973 diag::err_literal_operator_param)
15974 << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
15975 return true;
15976 }
15977
15978 QualType PointeeType = PT->getPointeeType();
15979 // First parameter must be const
15980 if (!PointeeType.isConstQualified() || PointeeType.isVolatileQualified()) {
15981 Diag((*Param)->getSourceRange().getBegin(),
15982 diag::err_literal_operator_param)
15983 << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
15984 return true;
15985 }
15986
15987 QualType InnerType = PointeeType.getUnqualifiedType();
15988 // Only const char *, const wchar_t*, const char8_t*, const char16_t*, and
15989 // const char32_t* are allowed as the first parameter to a two-parameter
15990 // function
15991 if (!(Context.hasSameType(InnerType, Context.CharTy) ||
15992 Context.hasSameType(InnerType, Context.WideCharTy) ||
15993 Context.hasSameType(InnerType, Context.Char8Ty) ||
15994 Context.hasSameType(InnerType, Context.Char16Ty) ||
15995 Context.hasSameType(InnerType, Context.Char32Ty))) {
15996 Diag((*Param)->getSourceRange().getBegin(),
15997 diag::err_literal_operator_param)
15998 << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
15999 return true;
16000 }
16001
16002 // Move on to the second and final parameter.
16003 ++Param;
16004
16005 // The second parameter must be a std::size_t.
16006 QualType SecondParamType = (*Param)->getType().getUnqualifiedType();
16007 if (!Context.hasSameType(SecondParamType, Context.getSizeType())) {
16008 Diag((*Param)->getSourceRange().getBegin(),
16009 diag::err_literal_operator_param)
16010 << SecondParamType << Context.getSizeType()
16011 << (*Param)->getSourceRange();
16012 return true;
16013 }
16014 } else {
16015 Diag(FnDecl->getLocation(), diag::err_literal_operator_bad_param_count);
16016 return true;
16017 }
16018
16019 // Parameters are good.
16020
16021 // A parameter-declaration-clause containing a default argument is not
16022 // equivalent to any of the permitted forms.
16023 for (auto Param : FnDecl->parameters()) {
16024 if (Param->hasDefaultArg()) {
16025 Diag(Param->getDefaultArgRange().getBegin(),
16026 diag::err_literal_operator_default_argument)
16027 << Param->getDefaultArgRange();
16028 break;
16029 }
16030 }
16031
16032 StringRef LiteralName
16033 = FnDecl->getDeclName().getCXXLiteralIdentifier()->getName();
16034 if (LiteralName[0] != '_' &&
16035 !getSourceManager().isInSystemHeader(FnDecl->getLocation())) {
16036 // C++11 [usrlit.suffix]p1:
16037 // Literal suffix identifiers that do not start with an underscore
16038 // are reserved for future standardization.
16039 Diag(FnDecl->getLocation(), diag::warn_user_literal_reserved)
16040 << StringLiteralParser::isValidUDSuffix(getLangOpts(), LiteralName);
16041 }
16042
16043 return false;
16044}
16045
16046/// ActOnStartLinkageSpecification - Parsed the beginning of a C++
16047/// linkage specification, including the language and (if present)
16048/// the '{'. ExternLoc is the location of the 'extern', Lang is the
16049/// language string literal. LBraceLoc, if valid, provides the location of
16050/// the '{' brace. Otherwise, this linkage specification does not
16051/// have any braces.
16052Decl *Sema::ActOnStartLinkageSpecification(Scope *S, SourceLocation ExternLoc,
16053 Expr *LangStr,
16054 SourceLocation LBraceLoc) {
16055 StringLiteral *Lit = cast<StringLiteral>(LangStr);
16056 if (!Lit->isAscii()) {
16057 Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_not_ascii)
16058 << LangStr->getSourceRange();
16059 return nullptr;
16060 }
16061
16062 StringRef Lang = Lit->getString();
16063 LinkageSpecDecl::LanguageIDs Language;
16064 if (Lang == "C")
16065 Language = LinkageSpecDecl::lang_c;
16066 else if (Lang == "C++")
16067 Language = LinkageSpecDecl::lang_cxx;
16068 else {
16069 Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_unknown)
16070 << LangStr->getSourceRange();
16071 return nullptr;
16072 }
16073
16074 // FIXME: Add all the various semantics of linkage specifications
16075
16076 LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext, ExternLoc,
16077 LangStr->getExprLoc(), Language,
16078 LBraceLoc.isValid());
16079 CurContext->addDecl(D);
16080 PushDeclContext(S, D);
16081 return D;
16082}
16083
16084/// ActOnFinishLinkageSpecification - Complete the definition of
16085/// the C++ linkage specification LinkageSpec. If RBraceLoc is
16086/// valid, it's the position of the closing '}' brace in a linkage
16087/// specification that uses braces.
16088Decl *Sema::ActOnFinishLinkageSpecification(Scope *S,
16089 Decl *LinkageSpec,
16090 SourceLocation RBraceLoc) {
16091 if (RBraceLoc.isValid()) {
16092 LinkageSpecDecl* LSDecl = cast<LinkageSpecDecl>(LinkageSpec);
16093 LSDecl->setRBraceLoc(RBraceLoc);
16094 }
16095 PopDeclContext();
16096 return LinkageSpec;
16097}
16098
16099Decl *Sema::ActOnEmptyDeclaration(Scope *S,
16100 const ParsedAttributesView &AttrList,
16101 SourceLocation SemiLoc) {
16102 Decl *ED = EmptyDecl::Create(Context, CurContext, SemiLoc);
16103 // Attribute declarations appertain to empty declaration so we handle
16104 // them here.
16105 ProcessDeclAttributeList(S, ED, AttrList);
16106
16107 CurContext->addDecl(ED);
16108 return ED;
16109}
16110
16111/// Perform semantic analysis for the variable declaration that
16112/// occurs within a C++ catch clause, returning the newly-created
16113/// variable.
16114VarDecl *Sema::BuildExceptionDeclaration(Scope *S,
16115 TypeSourceInfo *TInfo,
16116 SourceLocation StartLoc,
16117 SourceLocation Loc,
16118 IdentifierInfo *Name) {
16119 bool Invalid = false;
16120 QualType ExDeclType = TInfo->getType();
16121
16122 // Arrays and functions decay.
16123 if (ExDeclType->isArrayType())
16124 ExDeclType = Context.getArrayDecayedType(ExDeclType);
16125 else if (ExDeclType->isFunctionType())
16126 ExDeclType = Context.getPointerType(ExDeclType);
16127
16128 // C++ 15.3p1: The exception-declaration shall not denote an incomplete type.
16129 // The exception-declaration shall not denote a pointer or reference to an
16130 // incomplete type, other than [cv] void*.
16131 // N2844 forbids rvalue references.
16132 if (!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) {
16133 Diag(Loc, diag::err_catch_rvalue_ref);
16134 Invalid = true;
16135 }
16136
16137 if (ExDeclType->isVariablyModifiedType()) {
16138 Diag(Loc, diag::err_catch_variably_modified) << ExDeclType;
16139 Invalid = true;
16140 }
16141
16142 QualType BaseType = ExDeclType;
16143 int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference
16144 unsigned DK = diag::err_catch_incomplete;
16145 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
16146 BaseType = Ptr->getPointeeType();
16147 Mode = 1;
16148 DK = diag::err_catch_incomplete_ptr;
16149 } else if (const ReferenceType *Ref = BaseType->getAs<ReferenceType>()) {
16150 // For the purpose of error recovery, we treat rvalue refs like lvalue refs.
16151 BaseType = Ref->getPointeeType();
16152 Mode = 2;
16153 DK = diag::err_catch_incomplete_ref;
16154 }
16155 if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) &&
16156 !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK))
16157 Invalid = true;
16158
16159 if (!Invalid && Mode != 1 && BaseType->isSizelessType()) {
16160 Diag(Loc, diag::err_catch_sizeless) << (Mode == 2 ? 1 : 0) << BaseType;
16161 Invalid = true;
16162 }
16163
16164 if (!Invalid && !ExDeclType->isDependentType() &&
16165 RequireNonAbstractType(Loc, ExDeclType,
16166 diag::err_abstract_type_in_decl,
16167 AbstractVariableType))
16168 Invalid = true;
16169
16170 // Only the non-fragile NeXT runtime currently supports C++ catches
16171 // of ObjC types, and no runtime supports catching ObjC types by value.
16172 if (!Invalid && getLangOpts().ObjC) {
16173 QualType T = ExDeclType;
16174 if (const ReferenceType *RT = T->getAs<ReferenceType>())
16175 T = RT->getPointeeType();
16176
16177 if (T->isObjCObjectType()) {
16178 Diag(Loc, diag::err_objc_object_catch);
16179 Invalid = true;
16180 } else if (T->isObjCObjectPointerType()) {
16181 // FIXME: should this be a test for macosx-fragile specifically?
16182 if (getLangOpts().ObjCRuntime.isFragile())
16183 Diag(Loc, diag::warn_objc_pointer_cxx_catch_fragile);
16184 }
16185 }
16186
16187 VarDecl *ExDecl = VarDecl::Create(Context, CurContext, StartLoc, Loc, Name,
16188 ExDeclType, TInfo, SC_None);
16189 ExDecl->setExceptionVariable(true);
16190
16191 // In ARC, infer 'retaining' for variables of retainable type.
16192 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(ExDecl))
16193 Invalid = true;
16194
16195 if (!Invalid && !ExDeclType->isDependentType()) {
16196 if (const RecordType *recordType = ExDeclType->getAs<RecordType>()) {
16197 // Insulate this from anything else we might currently be parsing.
16198 EnterExpressionEvaluationContext scope(
16199 *this, ExpressionEvaluationContext::PotentiallyEvaluated);
16200
16201 // C++ [except.handle]p16:
16202 // The object declared in an exception-declaration or, if the
16203 // exception-declaration does not specify a name, a temporary (12.2) is
16204 // copy-initialized (8.5) from the exception object. [...]
16205 // The object is destroyed when the handler exits, after the destruction
16206 // of any automatic objects initialized within the handler.
16207 //
16208 // We just pretend to initialize the object with itself, then make sure
16209 // it can be destroyed later.
16210 QualType initType = Context.getExceptionObjectType(ExDeclType);
16211
16212 InitializedEntity entity =
16213 InitializedEntity::InitializeVariable(ExDecl);
16214 InitializationKind initKind =
16215 InitializationKind::CreateCopy(Loc, SourceLocation());
16216
16217 Expr *opaqueValue =
16218 new (Context) OpaqueValueExpr(Loc, initType, VK_LValue, OK_Ordinary);
16219 InitializationSequence sequence(*this, entity, initKind, opaqueValue);
16220 ExprResult result = sequence.Perform(*this, entity, initKind, opaqueValue);
16221 if (result.isInvalid())
16222 Invalid = true;
16223 else {
16224 // If the constructor used was non-trivial, set this as the
16225 // "initializer".
16226 CXXConstructExpr *construct = result.getAs<CXXConstructExpr>();
16227 if (!construct->getConstructor()->isTrivial()) {
16228 Expr *init = MaybeCreateExprWithCleanups(construct);
16229 ExDecl->setInit(init);
16230 }
16231
16232 // And make sure it's destructable.
16233 FinalizeVarWithDestructor(ExDecl, recordType);
16234 }
16235 }
16236 }
16237
16238 if (Invalid)
16239 ExDecl->setInvalidDecl();
16240
16241 return ExDecl;
16242}
16243
16244/// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch
16245/// handler.
16246Decl *Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) {
16247 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
16248 bool Invalid = D.isInvalidType();
16249
16250 // Check for unexpanded parameter packs.
16251 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
16252 UPPC_ExceptionType)) {
16253 TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
16254 D.getIdentifierLoc());
16255 Invalid = true;
16256 }
16257
16258 IdentifierInfo *II = D.getIdentifier();
16259 if (NamedDecl *PrevDecl = LookupSingleName(S, II, D.getIdentifierLoc(),
16260 LookupOrdinaryName,
16261 ForVisibleRedeclaration)) {
16262 // The scope should be freshly made just for us. There is just no way
16263 // it contains any previous declaration, except for function parameters in
16264 // a function-try-block's catch statement.
16265 assert(!S->isDeclScope(PrevDecl))((void)0);
16266 if (isDeclInScope(PrevDecl, CurContext, S)) {
16267 Diag(D.getIdentifierLoc(), diag::err_redefinition)
16268 << D.getIdentifier();
16269 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
16270 Invalid = true;
16271 } else if (PrevDecl->isTemplateParameter())
16272 // Maybe we will complain about the shadowed template parameter.
16273 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
16274 }
16275
16276 if (D.getCXXScopeSpec().isSet() && !Invalid) {
16277 Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator)
16278 << D.getCXXScopeSpec().getRange();
16279 Invalid = true;
16280 }
16281
16282 VarDecl *ExDecl = BuildExceptionDeclaration(
16283 S, TInfo, D.getBeginLoc(), D.getIdentifierLoc(), D.getIdentifier());
16284 if (Invalid)
16285 ExDecl->setInvalidDecl();
16286
16287 // Add the exception declaration into this scope.
16288 if (II)
16289 PushOnScopeChains(ExDecl, S);
16290 else
16291 CurContext->addDecl(ExDecl);
16292
16293 ProcessDeclAttributes(S, ExDecl, D);
16294 return ExDecl;
16295}
16296
16297Decl *Sema::ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,
16298 Expr *AssertExpr,
16299 Expr *AssertMessageExpr,
16300 SourceLocation RParenLoc) {
16301 StringLiteral *AssertMessage =
16302 AssertMessageExpr ? cast<StringLiteral>(AssertMessageExpr) : nullptr;
16303
16304 if (DiagnoseUnexpandedParameterPack(AssertExpr, UPPC_StaticAssertExpression))
16305 return nullptr;
16306
16307 return BuildStaticAssertDeclaration(StaticAssertLoc, AssertExpr,
16308 AssertMessage, RParenLoc, false);
16309}
16310
16311Decl *Sema::BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc,
16312 Expr *AssertExpr,
16313 StringLiteral *AssertMessage,
16314 SourceLocation RParenLoc,
16315 bool Failed) {
16316 assert(AssertExpr != nullptr && "Expected non-null condition")((void)0);
16317 if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent() &&
16318 !Failed) {
16319 // In a static_assert-declaration, the constant-expression shall be a
16320 // constant expression that can be contextually converted to bool.
16321 ExprResult Converted = PerformContextuallyConvertToBool(AssertExpr);
16322 if (Converted.isInvalid())
16323 Failed = true;
16324
16325 ExprResult FullAssertExpr =
16326 ActOnFinishFullExpr(Converted.get(), StaticAssertLoc,
16327 /*DiscardedValue*/ false,
16328 /*IsConstexpr*/ true);
16329 if (FullAssertExpr.isInvalid())
16330 Failed = true;
16331 else
16332 AssertExpr = FullAssertExpr.get();
16333
16334 llvm::APSInt Cond;
16335 if (!Failed && VerifyIntegerConstantExpression(
16336 AssertExpr, &Cond,
16337 diag::err_static_assert_expression_is_not_constant)
16338 .isInvalid())
16339 Failed = true;
16340
16341 if (!Failed && !Cond) {
16342 SmallString<256> MsgBuffer;
16343 llvm::raw_svector_ostream Msg(MsgBuffer);
16344 if (AssertMessage)
16345 AssertMessage->printPretty(Msg, nullptr, getPrintingPolicy());
16346
16347 Expr *InnerCond = nullptr;
16348 std::string InnerCondDescription;
16349 std::tie(InnerCond, InnerCondDescription) =
16350 findFailedBooleanCondition(Converted.get());
16351 if (InnerCond && isa<ConceptSpecializationExpr>(InnerCond)) {
16352 // Drill down into concept specialization expressions to see why they
16353 // weren't satisfied.
16354 Diag(StaticAssertLoc, diag::err_static_assert_failed)
16355 << !AssertMessage << Msg.str() << AssertExpr->getSourceRange();
16356 ConstraintSatisfaction Satisfaction;
16357 if (!CheckConstraintSatisfaction(InnerCond, Satisfaction))
16358 DiagnoseUnsatisfiedConstraint(Satisfaction);
16359 } else if (InnerCond && !isa<CXXBoolLiteralExpr>(InnerCond)
16360 && !isa<IntegerLiteral>(InnerCond)) {
16361 Diag(StaticAssertLoc, diag::err_static_assert_requirement_failed)
16362 << InnerCondDescription << !AssertMessage
16363 << Msg.str() << InnerCond->getSourceRange();
16364 } else {
16365 Diag(StaticAssertLoc, diag::err_static_assert_failed)
16366 << !AssertMessage << Msg.str() << AssertExpr->getSourceRange();
16367 }
16368 Failed = true;
16369 }
16370 } else {
16371 ExprResult FullAssertExpr = ActOnFinishFullExpr(AssertExpr, StaticAssertLoc,
16372 /*DiscardedValue*/false,
16373 /*IsConstexpr*/true);
16374 if (FullAssertExpr.isInvalid())
16375 Failed = true;
16376 else
16377 AssertExpr = FullAssertExpr.get();
16378 }
16379
16380 Decl *Decl = StaticAssertDecl::Create(Context, CurContext, StaticAssertLoc,
16381 AssertExpr, AssertMessage, RParenLoc,
16382 Failed);
16383
16384 CurContext->addDecl(Decl);
16385 return Decl;
16386}
16387
16388/// Perform semantic analysis of the given friend type declaration.
16389///
16390/// \returns A friend declaration that.
16391FriendDecl *Sema::CheckFriendTypeDecl(SourceLocation LocStart,
16392 SourceLocation FriendLoc,
16393 TypeSourceInfo *TSInfo) {
16394 assert(TSInfo && "NULL TypeSourceInfo for friend type declaration")((void)0);
16395
16396 QualType T = TSInfo->getType();
16397 SourceRange TypeRange = TSInfo->getTypeLoc().getLocalSourceRange();
16398
16399 // C++03 [class.friend]p2:
16400 // An elaborated-type-specifier shall be used in a friend declaration
16401 // for a class.*
16402 //
16403 // * The class-key of the elaborated-type-specifier is required.
16404 if (!CodeSynthesisContexts.empty()) {
16405 // Do not complain about the form of friend template types during any kind
16406 // of code synthesis. For template instantiation, we will have complained
16407 // when the template was defined.
16408 } else {
16409 if (!T->isElaboratedTypeSpecifier()) {
16410 // If we evaluated the type to a record type, suggest putting
16411 // a tag in front.
16412 if (const RecordType *RT = T->getAs<RecordType>()) {
16413 RecordDecl *RD = RT->getDecl();
16414
16415 SmallString<16> InsertionText(" ");
16416 InsertionText += RD->getKindName();
16417
16418 Diag(TypeRange.getBegin(),
16419 getLangOpts().CPlusPlus11 ?
16420 diag::warn_cxx98_compat_unelaborated_friend_type :
16421 diag::ext_unelaborated_friend_type)
16422 << (unsigned) RD->getTagKind()
16423 << T
16424 << FixItHint::CreateInsertion(getLocForEndOfToken(FriendLoc),
16425 InsertionText);
16426 } else {
16427 Diag(FriendLoc,
16428 getLangOpts().CPlusPlus11 ?
16429 diag::warn_cxx98_compat_nonclass_type_friend :
16430 diag::ext_nonclass_type_friend)
16431 << T
16432 << TypeRange;
16433 }
16434 } else if (T->getAs<EnumType>()) {
16435 Diag(FriendLoc,
16436 getLangOpts().CPlusPlus11 ?
16437 diag::warn_cxx98_compat_enum_friend :
16438 diag::ext_enum_friend)
16439 << T
16440 << TypeRange;
16441 }
16442
16443 // C++11 [class.friend]p3:
16444 // A friend declaration that does not declare a function shall have one
16445 // of the following forms:
16446 // friend elaborated-type-specifier ;
16447 // friend simple-type-specifier ;
16448 // friend typename-specifier ;
16449 if (getLangOpts().CPlusPlus11 && LocStart != FriendLoc)
16450 Diag(FriendLoc, diag::err_friend_not_first_in_declaration) << T;
16451 }
16452
16453 // If the type specifier in a friend declaration designates a (possibly
16454 // cv-qualified) class type, that class is declared as a friend; otherwise,
16455 // the friend declaration is ignored.
16456 return FriendDecl::Create(Context, CurContext,
16457 TSInfo->getTypeLoc().getBeginLoc(), TSInfo,
16458 FriendLoc);
16459}
16460
16461/// Handle a friend tag declaration where the scope specifier was
16462/// templated.
16463Decl *Sema::ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
16464 unsigned TagSpec, SourceLocation TagLoc,
16465 CXXScopeSpec &SS, IdentifierInfo *Name,
16466 SourceLocation NameLoc,
16467 const ParsedAttributesView &Attr,
16468 MultiTemplateParamsArg TempParamLists) {
16469 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
16470
16471 bool IsMemberSpecialization = false;
16472 bool Invalid = false;
16473
16474 if (TemplateParameterList *TemplateParams =
16475 MatchTemplateParametersToScopeSpecifier(
16476 TagLoc, NameLoc, SS, nullptr, TempParamLists, /*friend*/ true,
16477 IsMemberSpecialization, Invalid)) {
16478 if (TemplateParams->size() > 0) {
16479 // This is a declaration of a class template.
16480 if (Invalid)
16481 return nullptr;
16482
16483 return CheckClassTemplate(S, TagSpec, TUK_Friend, TagLoc, SS, Name,
16484 NameLoc, Attr, TemplateParams, AS_public,
16485 /*ModulePrivateLoc=*/SourceLocation(),
16486 FriendLoc, TempParamLists.size() - 1,
16487 TempParamLists.data()).get();
16488 } else {
16489 // The "template<>" header is extraneous.
16490 Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams)
16491 << TypeWithKeyword::getTagTypeKindName(Kind) << Name;
16492 IsMemberSpecialization = true;
16493 }
16494 }
16495
16496 if (Invalid) return nullptr;
16497
16498 bool isAllExplicitSpecializations = true;
16499 for (unsigned I = TempParamLists.size(); I-- > 0; ) {
16500 if (TempParamLists[I]->size()) {
16501 isAllExplicitSpecializations = false;
16502 break;
16503 }
16504 }
16505
16506 // FIXME: don't ignore attributes.
16507
16508 // If it's explicit specializations all the way down, just forget
16509 // about the template header and build an appropriate non-templated
16510 // friend. TODO: for source fidelity, remember the headers.
16511 if (isAllExplicitSpecializations) {
16512 if (SS.isEmpty()) {
16513 bool Owned = false;
16514 bool IsDependent = false;
16515 return ActOnTag(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc,
16516 Attr, AS_public,
16517 /*ModulePrivateLoc=*/SourceLocation(),
16518 MultiTemplateParamsArg(), Owned, IsDependent,
16519 /*ScopedEnumKWLoc=*/SourceLocation(),
16520 /*ScopedEnumUsesClassTag=*/false,
16521 /*UnderlyingType=*/TypeResult(),
16522 /*IsTypeSpecifier=*/false,
16523 /*IsTemplateParamOrArg=*/false);
16524 }
16525
16526 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
16527 ElaboratedTypeKeyword Keyword
16528 = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
16529 QualType T = CheckTypenameType(Keyword, TagLoc, QualifierLoc,
16530 *Name, NameLoc);
16531 if (T.isNull())
16532 return nullptr;
16533
16534 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
16535 if (isa<DependentNameType>(T)) {
16536 DependentNameTypeLoc TL =
16537 TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
16538 TL.setElaboratedKeywordLoc(TagLoc);
16539 TL.setQualifierLoc(QualifierLoc);
16540 TL.setNameLoc(NameLoc);
16541 } else {
16542 ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>();
16543 TL.setElaboratedKeywordLoc(TagLoc);
16544 TL.setQualifierLoc(QualifierLoc);
16545 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(NameLoc);
16546 }
16547
16548 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
16549 TSI, FriendLoc, TempParamLists);
16550 Friend->setAccess(AS_public);
16551 CurContext->addDecl(Friend);
16552 return Friend;
16553 }
16554
16555 assert(SS.isNotEmpty() && "valid templated tag with no SS and no direct?")((void)0);
16556
16557
16558
16559 // Handle the case of a templated-scope friend class. e.g.
16560 // template <class T> class A<T>::B;
16561 // FIXME: we don't support these right now.
16562 Diag(NameLoc, diag::warn_template_qualified_friend_unsupported)
16563 << SS.getScopeRep() << SS.getRange() << cast<CXXRecordDecl>(CurContext);
16564 ElaboratedTypeKeyword ETK = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
16565 QualType T = Context.getDependentNameType(ETK, SS.getScopeRep(), Name);
16566 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
16567 DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
16568 TL.setElaboratedKeywordLoc(TagLoc);
16569 TL.setQualifierLoc(SS.getWithLocInContext(Context));
16570 TL.setNameLoc(NameLoc);
16571
16572 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
16573 TSI, FriendLoc, TempParamLists);
16574 Friend->setAccess(AS_public);
16575 Friend->setUnsupportedFriend(true);
16576 CurContext->addDecl(Friend);
16577 return Friend;
16578}
16579
16580/// Handle a friend type declaration. This works in tandem with
16581/// ActOnTag.
16582///
16583/// Notes on friend class templates:
16584///
16585/// We generally treat friend class declarations as if they were
16586/// declaring a class. So, for example, the elaborated type specifier
16587/// in a friend declaration is required to obey the restrictions of a
16588/// class-head (i.e. no typedefs in the scope chain), template
16589/// parameters are required to match up with simple template-ids, &c.
16590/// However, unlike when declaring a template specialization, it's
16591/// okay to refer to a template specialization without an empty
16592/// template parameter declaration, e.g.
16593/// friend class A<T>::B<unsigned>;
16594/// We permit this as a special case; if there are any template
16595/// parameters present at all, require proper matching, i.e.
16596/// template <> template \<class T> friend class A<int>::B;
16597Decl *Sema::ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS,
16598 MultiTemplateParamsArg TempParams) {
16599 SourceLocation Loc = DS.getBeginLoc();
16600
16601 assert(DS.isFriendSpecified())((void)0);
16602 assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified)((void)0);
16603
16604 // C++ [class.friend]p3:
16605 // A friend declaration that does not declare a function shall have one of
16606 // the following forms:
16607 // friend elaborated-type-specifier ;
16608 // friend simple-type-specifier ;
16609 // friend typename-specifier ;
16610 //
16611 // Any declaration with a type qualifier does not have that form. (It's
16612 // legal to specify a qualified type as a friend, you just can't write the
16613 // keywords.)
16614 if (DS.getTypeQualifiers()) {
16615 if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
16616 Diag(DS.getConstSpecLoc(), diag::err_friend_decl_spec) << "const";
16617 if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
16618 Diag(DS.getVolatileSpecLoc(), diag::err_friend_decl_spec) << "volatile";
16619 if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
16620 Diag(DS.getRestrictSpecLoc(), diag::err_friend_decl_spec) << "restrict";
16621 if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
16622 Diag(DS.getAtomicSpecLoc(), diag::err_friend_decl_spec) << "_Atomic";
16623 if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
16624 Diag(DS.getUnalignedSpecLoc(), diag::err_friend_decl_spec) << "__unaligned";
16625 }
16626
16627 // Try to convert the decl specifier to a type. This works for
16628 // friend templates because ActOnTag never produces a ClassTemplateDecl
16629 // for a TUK_Friend.
16630 Declarator TheDeclarator(DS, DeclaratorContext::Member);
16631 TypeSourceInfo *TSI = GetTypeForDeclarator(TheDeclarator, S);
16632 QualType T = TSI->getType();
16633 if (TheDeclarator.isInvalidType())
16634 return nullptr;
16635
16636 if (DiagnoseUnexpandedParameterPack(Loc, TSI, UPPC_FriendDeclaration))
16637 return nullptr;
16638
16639 // This is definitely an error in C++98. It's probably meant to
16640 // be forbidden in C++0x, too, but the specification is just
16641 // poorly written.
16642 //
16643 // The problem is with declarations like the following:
16644 // template <T> friend A<T>::foo;
16645 // where deciding whether a class C is a friend or not now hinges
16646 // on whether there exists an instantiation of A that causes
16647 // 'foo' to equal C. There are restrictions on class-heads
16648 // (which we declare (by fiat) elaborated friend declarations to
16649 // be) that makes this tractable.
16650 //
16651 // FIXME: handle "template <> friend class A<T>;", which
16652 // is possibly well-formed? Who even knows?
16653 if (TempParams.size() && !T->isElaboratedTypeSpecifier()) {
16654 Diag(Loc, diag::err_tagless_friend_type_template)
16655 << DS.getSourceRange();
16656 return nullptr;
16657 }
16658
16659 // C++98 [class.friend]p1: A friend of a class is a function
16660 // or class that is not a member of the class . . .
16661 // This is fixed in DR77, which just barely didn't make the C++03
16662 // deadline. It's also a very silly restriction that seriously
16663 // affects inner classes and which nobody else seems to implement;
16664 // thus we never diagnose it, not even in -pedantic.
16665 //
16666 // But note that we could warn about it: it's always useless to
16667 // friend one of your own members (it's not, however, worthless to
16668 // friend a member of an arbitrary specialization of your template).
16669
16670 Decl *D;
16671 if (!TempParams.empty())
16672 D = FriendTemplateDecl::Create(Context, CurContext, Loc,
16673 TempParams,
16674 TSI,
16675 DS.getFriendSpecLoc());
16676 else
16677 D = CheckFriendTypeDecl(Loc, DS.getFriendSpecLoc(), TSI);
16678
16679 if (!D)
16680 return nullptr;
16681
16682 D->setAccess(AS_public);
16683 CurContext->addDecl(D);
16684
16685 return D;
16686}
16687
16688NamedDecl *Sema::ActOnFriendFunctionDecl(Scope *S, Declarator &D,
16689 MultiTemplateParamsArg TemplateParams) {
16690 const DeclSpec &DS = D.getDeclSpec();
16691
16692 assert(DS.isFriendSpecified())((void)0);
16693 assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified)((void)0);
16694
16695 SourceLocation Loc = D.getIdentifierLoc();
16696 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
16697
16698 // C++ [class.friend]p1
16699 // A friend of a class is a function or class....
16700 // Note that this sees through typedefs, which is intended.
16701 // It *doesn't* see through dependent types, which is correct
16702 // according to [temp.arg.type]p3:
16703 // If a declaration acquires a function type through a
16704 // type dependent on a template-parameter and this causes
16705 // a declaration that does not use the syntactic form of a
16706 // function declarator to have a function type, the program
16707 // is ill-formed.
16708 if (!TInfo->getType()->isFunctionType()) {
16709 Diag(Loc, diag::err_unexpected_friend);
16710
16711 // It might be worthwhile to try to recover by creating an
16712 // appropriate declaration.
16713 return nullptr;
16714 }
16715
16716 // C++ [namespace.memdef]p3
16717 // - If a friend declaration in a non-local class first declares a
16718 // class or function, the friend class or function is a member
16719 // of the innermost enclosing namespace.
16720 // - The name of the friend is not found by simple name lookup
16721 // until a matching declaration is provided in that namespace
16722 // scope (either before or after the class declaration granting
16723 // friendship).
16724 // - If a friend function is called, its name may be found by the
16725 // name lookup that considers functions from namespaces and
16726 // classes associated with the types of the function arguments.
16727 // - When looking for a prior declaration of a class or a function
16728 // declared as a friend, scopes outside the innermost enclosing
16729 // namespace scope are not considered.
16730
16731 CXXScopeSpec &SS = D.getCXXScopeSpec();
16732 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
16733 assert(NameInfo.getName())((void)0);
16734
16735 // Check for unexpanded parameter packs.
16736 if (DiagnoseUnexpandedParameterPack(Loc, TInfo, UPPC_FriendDeclaration) ||
16737 DiagnoseUnexpandedParameterPack(NameInfo, UPPC_FriendDeclaration) ||
16738 DiagnoseUnexpandedParameterPack(SS, UPPC_FriendDeclaration))
16739 return nullptr;
16740
16741 // The context we found the declaration in, or in which we should
16742 // create the declaration.
16743 DeclContext *DC;
16744 Scope *DCScope = S;
16745 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
16746 ForExternalRedeclaration);
16747
16748 // There are five cases here.
16749 // - There's no scope specifier and we're in a local class. Only look
16750 // for functions declared in the immediately-enclosing block scope.
16751 // We recover from invalid scope qualifiers as if they just weren't there.
16752 FunctionDecl *FunctionContainingLocalClass = nullptr;
16753 if ((SS.isInvalid() || !SS.isSet()) &&
16754 (FunctionContainingLocalClass =
16755 cast<CXXRecordDecl>(CurContext)->isLocalClass())) {
16756 // C++11 [class.friend]p11:
16757 // If a friend declaration appears in a local class and the name
16758 // specified is an unqualified name, a prior declaration is
16759 // looked up without considering scopes that are outside the
16760 // innermost enclosing non-class scope. For a friend function
16761 // declaration, if there is no prior declaration, the program is
16762 // ill-formed.
16763
16764 // Find the innermost enclosing non-class scope. This is the block
16765 // scope containing the local class definition (or for a nested class,
16766 // the outer local class).
16767 DCScope = S->getFnParent();
16768
16769 // Look up the function name in the scope.
16770 Previous.clear(LookupLocalFriendName);
16771 LookupName(Previous, S, /*AllowBuiltinCreation*/false);
16772
16773 if (!Previous.empty()) {
16774 // All possible previous declarations must have the same context:
16775 // either they were declared at block scope or they are members of
16776 // one of the enclosing local classes.
16777 DC = Previous.getRepresentativeDecl()->getDeclContext();
16778 } else {
16779 // This is ill-formed, but provide the context that we would have
16780 // declared the function in, if we were permitted to, for error recovery.
16781 DC = FunctionContainingLocalClass;
16782 }
16783 adjustContextForLocalExternDecl(DC);
16784
16785 // C++ [class.friend]p6:
16786 // A function can be defined in a friend declaration of a class if and
16787 // only if the class is a non-local class (9.8), the function name is
16788 // unqualified, and the function has namespace scope.
16789 if (D.isFunctionDefinition()) {
16790 Diag(NameInfo.getBeginLoc(), diag::err_friend_def_in_local_class);
16791 }
16792
16793 // - There's no scope specifier, in which case we just go to the
16794 // appropriate scope and look for a function or function template
16795 // there as appropriate.
16796 } else if (SS.isInvalid() || !SS.isSet()) {
16797 // C++11 [namespace.memdef]p3:
16798 // If the name in a friend declaration is neither qualified nor
16799 // a template-id and the declaration is a function or an
16800 // elaborated-type-specifier, the lookup to determine whether
16801 // the entity has been previously declared shall not consider
16802 // any scopes outside the innermost enclosing namespace.
16803 bool isTemplateId =
16804 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId;
16805
16806 // Find the appropriate context according to the above.
16807 DC = CurContext;
16808
16809 // Skip class contexts. If someone can cite chapter and verse
16810 // for this behavior, that would be nice --- it's what GCC and
16811 // EDG do, and it seems like a reasonable intent, but the spec
16812 // really only says that checks for unqualified existing
16813 // declarations should stop at the nearest enclosing namespace,
16814 // not that they should only consider the nearest enclosing
16815 // namespace.
16816 while (DC->isRecord())
16817 DC = DC->getParent();
16818
16819 DeclContext *LookupDC = DC;
16820 while (LookupDC->isTransparentContext())
16821 LookupDC = LookupDC->getParent();
16822
16823 while (true) {
16824 LookupQualifiedName(Previous, LookupDC);
16825
16826 if (!Previous.empty()) {
16827 DC = LookupDC;
16828 break;
16829 }
16830
16831 if (isTemplateId) {
16832 if (isa<TranslationUnitDecl>(LookupDC)) break;
16833 } else {
16834 if (LookupDC->isFileContext()) break;
16835 }
16836 LookupDC = LookupDC->getParent();
16837 }
16838
16839 DCScope = getScopeForDeclContext(S, DC);
16840
16841 // - There's a non-dependent scope specifier, in which case we
16842 // compute it and do a previous lookup there for a function
16843 // or function template.
16844 } else if (!SS.getScopeRep()->isDependent()) {
16845 DC = computeDeclContext(SS);
16846 if (!DC) return nullptr;
16847
16848 if (RequireCompleteDeclContext(SS, DC)) return nullptr;
16849
16850 LookupQualifiedName(Previous, DC);
16851
16852 // C++ [class.friend]p1: A friend of a class is a function or
16853 // class that is not a member of the class . . .
16854 if (DC->Equals(CurContext))
16855 Diag(DS.getFriendSpecLoc(),
16856 getLangOpts().CPlusPlus11 ?
16857 diag::warn_cxx98_compat_friend_is_member :
16858 diag::err_friend_is_member);
16859
16860 if (D.isFunctionDefinition()) {
16861 // C++ [class.friend]p6:
16862 // A function can be defined in a friend declaration of a class if and
16863 // only if the class is a non-local class (9.8), the function name is
16864 // unqualified, and the function has namespace scope.
16865 //
16866 // FIXME: We should only do this if the scope specifier names the
16867 // innermost enclosing namespace; otherwise the fixit changes the
16868 // meaning of the code.
16869 SemaDiagnosticBuilder DB
16870 = Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def);
16871
16872 DB << SS.getScopeRep();
16873 if (DC->isFileContext())
16874 DB << FixItHint::CreateRemoval(SS.getRange());
16875 SS.clear();
16876 }
16877
16878 // - There's a scope specifier that does not match any template
16879 // parameter lists, in which case we use some arbitrary context,
16880 // create a method or method template, and wait for instantiation.
16881 // - There's a scope specifier that does match some template
16882 // parameter lists, which we don't handle right now.
16883 } else {
16884 if (D.isFunctionDefinition()) {
16885 // C++ [class.friend]p6:
16886 // A function can be defined in a friend declaration of a class if and
16887 // only if the class is a non-local class (9.8), the function name is
16888 // unqualified, and the function has namespace scope.
16889 Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def)
16890 << SS.getScopeRep();
16891 }
16892
16893 DC = CurContext;
16894 assert(isa<CXXRecordDecl>(DC) && "friend declaration not in class?")((void)0);
16895 }
16896
16897 if (!DC->isRecord()) {
16898 int DiagArg = -1;
16899 switch (D.getName().getKind()) {
16900 case UnqualifiedIdKind::IK_ConstructorTemplateId:
16901 case UnqualifiedIdKind::IK_ConstructorName:
16902 DiagArg = 0;
16903 break;
16904 case UnqualifiedIdKind::IK_DestructorName:
16905 DiagArg = 1;
16906 break;
16907 case UnqualifiedIdKind::IK_ConversionFunctionId:
16908 DiagArg = 2;
16909 break;
16910 case UnqualifiedIdKind::IK_DeductionGuideName:
16911 DiagArg = 3;
16912 break;
16913 case UnqualifiedIdKind::IK_Identifier:
16914 case UnqualifiedIdKind::IK_ImplicitSelfParam:
16915 case UnqualifiedIdKind::IK_LiteralOperatorId:
16916 case UnqualifiedIdKind::IK_OperatorFunctionId:
16917 case UnqualifiedIdKind::IK_TemplateId:
16918 break;
16919 }
16920 // This implies that it has to be an operator or function.
16921 if (DiagArg >= 0) {
16922 Diag(Loc, diag::err_introducing_special_friend) << DiagArg;
16923 return nullptr;
16924 }
16925 }
16926
16927 // FIXME: This is an egregious hack to cope with cases where the scope stack
16928 // does not contain the declaration context, i.e., in an out-of-line
16929 // definition of a class.
16930 Scope FakeDCScope(S, Scope::DeclScope, Diags);
16931 if (!DCScope) {
16932 FakeDCScope.setEntity(DC);
16933 DCScope = &FakeDCScope;
16934 }
16935
16936 bool AddToScope = true;
16937 NamedDecl *ND = ActOnFunctionDeclarator(DCScope, D, DC, TInfo, Previous,
16938 TemplateParams, AddToScope);
16939 if (!ND) return nullptr;
16940
16941 assert(ND->getLexicalDeclContext() == CurContext)((void)0);
16942
16943 // If we performed typo correction, we might have added a scope specifier
16944 // and changed the decl context.
16945 DC = ND->getDeclContext();
16946
16947 // Add the function declaration to the appropriate lookup tables,
16948 // adjusting the redeclarations list as necessary. We don't
16949 // want to do this yet if the friending class is dependent.
16950 //
16951 // Also update the scope-based lookup if the target context's
16952 // lookup context is in lexical scope.
16953 if (!CurContext->isDependentContext()) {
16954 DC = DC->getRedeclContext();
16955 DC->makeDeclVisibleInContext(ND);
16956 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
16957 PushOnScopeChains(ND, EnclosingScope, /*AddToContext=*/ false);
16958 }
16959
16960 FriendDecl *FrD = FriendDecl::Create(Context, CurContext,
16961 D.getIdentifierLoc(), ND,
16962 DS.getFriendSpecLoc());
16963 FrD->setAccess(AS_public);
16964 CurContext->addDecl(FrD);
16965
16966 if (ND->isInvalidDecl()) {
16967 FrD->setInvalidDecl();
16968 } else {
16969 if (DC->isRecord()) CheckFriendAccess(ND);
16970
16971 FunctionDecl *FD;
16972 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
16973 FD = FTD->getTemplatedDecl();
16974 else
16975 FD = cast<FunctionDecl>(ND);
16976
16977 // C++11 [dcl.fct.default]p4: If a friend declaration specifies a
16978 // default argument expression, that declaration shall be a definition
16979 // and shall be the only declaration of the function or function
16980 // template in the translation unit.
16981 if (functionDeclHasDefaultArgument(FD)) {
16982 // We can't look at FD->getPreviousDecl() because it may not have been set
16983 // if we're in a dependent context. If the function is known to be a
16984 // redeclaration, we will have narrowed Previous down to the right decl.
16985 if (D.isRedeclaration()) {
16986 Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
16987 Diag(Previous.getRepresentativeDecl()->getLocation(),
16988 diag::note_previous_declaration);
16989 } else if (!D.isFunctionDefinition())
16990 Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_must_be_def);
16991 }
16992
16993 // Mark templated-scope function declarations as unsupported.
16994 if (FD->getNumTemplateParameterLists() && SS.isValid()) {
16995 Diag(FD->getLocation(), diag::warn_template_qualified_friend_unsupported)
16996 << SS.getScopeRep() << SS.getRange()
16997 << cast<CXXRecordDecl>(CurContext);
16998 FrD->setUnsupportedFriend(true);
16999 }
17000 }
17001
17002 warnOnReservedIdentifier(ND);
17003
17004 return ND;
17005}
17006
17007void Sema::SetDeclDeleted(Decl *Dcl, SourceLocation DelLoc) {
17008 AdjustDeclIfTemplate(Dcl);
17009
17010 FunctionDecl *Fn = dyn_cast_or_null<FunctionDecl>(Dcl);
17011 if (!Fn) {
17012 Diag(DelLoc, diag::err_deleted_non_function);
17013 return;
17014 }
17015
17016 // Deleted function does not have a body.
17017 Fn->setWillHaveBody(false);
17018
17019 if (const FunctionDecl *Prev = Fn->getPreviousDecl()) {
17020 // Don't consider the implicit declaration we generate for explicit
17021 // specializations. FIXME: Do not generate these implicit declarations.
17022 if ((Prev->getTemplateSpecializationKind() != TSK_ExplicitSpecialization ||
17023 Prev->getPreviousDecl()) &&
17024 !Prev->isDefined()) {
17025 Diag(DelLoc, diag::err_deleted_decl_not_first);
17026 Diag(Prev->getLocation().isInvalid() ? DelLoc : Prev->getLocation(),
17027 Prev->isImplicit() ? diag::note_previous_implicit_declaration
17028 : diag::note_previous_declaration);
17029 // We can't recover from this; the declaration might have already
17030 // been used.
17031 Fn->setInvalidDecl();
17032 return;
17033 }
17034
17035 // To maintain the invariant that functions are only deleted on their first
17036 // declaration, mark the implicitly-instantiated declaration of the
17037 // explicitly-specialized function as deleted instead of marking the
17038 // instantiated redeclaration.
17039 Fn = Fn->getCanonicalDecl();
17040 }
17041
17042 // dllimport/dllexport cannot be deleted.
17043 if (const InheritableAttr *DLLAttr = getDLLAttr(Fn)) {
17044 Diag(Fn->getLocation(), diag::err_attribute_dll_deleted) << DLLAttr;
17045 Fn->setInvalidDecl();
17046 }
17047
17048 // C++11 [basic.start.main]p3:
17049 // A program that defines main as deleted [...] is ill-formed.
17050 if (Fn->isMain())
17051 Diag(DelLoc, diag::err_deleted_main);
17052
17053 // C++11 [dcl.fct.def.delete]p4:
17054 // A deleted function is implicitly inline.
17055 Fn->setImplicitlyInline();
17056 Fn->setDeletedAsWritten();
17057}
17058
17059void Sema::SetDeclDefaulted(Decl *Dcl, SourceLocation DefaultLoc) {
17060 if (!Dcl || Dcl->isInvalidDecl())
17061 return;
17062
17063 auto *FD = dyn_cast<FunctionDecl>(Dcl);
17064 if (!FD) {
17065 if (auto *FTD = dyn_cast<FunctionTemplateDecl>(Dcl)) {
17066 if (getDefaultedFunctionKind(FTD->getTemplatedDecl()).isComparison()) {
17067 Diag(DefaultLoc, diag::err_defaulted_comparison_template);
17068 return;
17069 }
17070 }
17071
17072 Diag(DefaultLoc, diag::err_default_special_members)
17073 << getLangOpts().CPlusPlus20;
17074 return;
17075 }
17076
17077 // Reject if this can't possibly be a defaultable function.
17078 DefaultedFunctionKind DefKind = getDefaultedFunctionKind(FD);
17079 if (!DefKind &&
17080 // A dependent function that doesn't locally look defaultable can
17081 // still instantiate to a defaultable function if it's a constructor
17082 // or assignment operator.
17083 (!FD->isDependentContext() ||
17084 (!isa<CXXConstructorDecl>(FD) &&
17085 FD->getDeclName().getCXXOverloadedOperator() != OO_Equal))) {
17086 Diag(DefaultLoc, diag::err_default_special_members)
17087 << getLangOpts().CPlusPlus20;
17088 return;
17089 }
17090
17091 if (DefKind.isComparison() &&
17092 !isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
17093 Diag(FD->getLocation(), diag::err_defaulted_comparison_out_of_class)
17094 << (int)DefKind.asComparison();
17095 return;
17096 }
17097
17098 // Issue compatibility warning. We already warned if the operator is
17099 // 'operator<=>' when parsing the '<=>' token.
17100 if (DefKind.isComparison() &&
17101 DefKind.asComparison() != DefaultedComparisonKind::ThreeWay) {
17102 Diag(DefaultLoc, getLangOpts().CPlusPlus20
17103 ? diag::warn_cxx17_compat_defaulted_comparison
17104 : diag::ext_defaulted_comparison);
17105 }
17106
17107 FD->setDefaulted();
17108 FD->setExplicitlyDefaulted();
17109
17110 // Defer checking functions that are defaulted in a dependent context.
17111 if (FD->isDependentContext())
17112 return;
17113
17114 // Unset that we will have a body for this function. We might not,
17115 // if it turns out to be trivial, and we don't need this marking now
17116 // that we've marked it as defaulted.
17117 FD->setWillHaveBody(false);
17118
17119 // If this definition appears within the record, do the checking when
17120 // the record is complete. This is always the case for a defaulted
17121 // comparison.
17122 if (DefKind.isComparison())
17123 return;
17124 auto *MD = cast<CXXMethodDecl>(FD);
17125
17126 const FunctionDecl *Primary = FD;
17127 if (const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
17128 // Ask the template instantiation pattern that actually had the
17129 // '= default' on it.
17130 Primary = Pattern;
17131
17132 // If the method was defaulted on its first declaration, we will have
17133 // already performed the checking in CheckCompletedCXXClass. Such a
17134 // declaration doesn't trigger an implicit definition.
17135 if (Primary->getCanonicalDecl()->isDefaulted())
17136 return;
17137
17138 // FIXME: Once we support defining comparisons out of class, check for a
17139 // defaulted comparison here.
17140 if (CheckExplicitlyDefaultedSpecialMember(MD, DefKind.asSpecialMember()))
17141 MD->setInvalidDecl();
17142 else
17143 DefineDefaultedFunction(*this, MD, DefaultLoc);
17144}
17145
17146static void SearchForReturnInStmt(Sema &Self, Stmt *S) {
17147 for (Stmt *SubStmt : S->children()) {
17148 if (!SubStmt)
17149 continue;
17150 if (isa<ReturnStmt>(SubStmt))
17151 Self.Diag(SubStmt->getBeginLoc(),
17152 diag::err_return_in_constructor_handler);
17153 if (!isa<Expr>(SubStmt))
17154 SearchForReturnInStmt(Self, SubStmt);
17155 }
17156}
17157
17158void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) {
17159 for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) {
17160 CXXCatchStmt *Handler = TryBlock->getHandler(I);
17161 SearchForReturnInStmt(*this, Handler);
17162 }
17163}
17164
17165bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
17166 const CXXMethodDecl *Old) {
17167 const auto *NewFT = New->getType()->castAs<FunctionProtoType>();
17168 const auto *OldFT = Old->getType()->castAs<FunctionProtoType>();
17169
17170 if (OldFT->hasExtParameterInfos()) {
17171 for (unsigned I = 0, E = OldFT->getNumParams(); I != E; ++I)
17172 // A parameter of the overriding method should be annotated with noescape
17173 // if the corresponding parameter of the overridden method is annotated.
17174 if (OldFT->getExtParameterInfo(I).isNoEscape() &&
17175 !NewFT->getExtParameterInfo(I).isNoEscape()) {
17176 Diag(New->getParamDecl(I)->getLocation(),
17177 diag::warn_overriding_method_missing_noescape);
17178 Diag(Old->getParamDecl(I)->getLocation(),
17179 diag::note_overridden_marked_noescape);
17180 }
17181 }
17182
17183 // Virtual overrides must have the same code_seg.
17184 const auto *OldCSA = Old->getAttr<CodeSegAttr>();
17185 const auto *NewCSA = New->getAttr<CodeSegAttr>();
17186 if ((NewCSA || OldCSA) &&
17187 (!OldCSA || !NewCSA || NewCSA->getName() != OldCSA->getName())) {
17188 Diag(New->getLocation(), diag::err_mismatched_code_seg_override);
17189 Diag(Old->getLocation(), diag::note_previous_declaration);
17190 return true;
17191 }
17192
17193 CallingConv NewCC = NewFT->getCallConv(), OldCC = OldFT->getCallConv();
17194
17195 // If the calling conventions match, everything is fine
17196 if (NewCC == OldCC)
17197 return false;
17198
17199 // If the calling conventions mismatch because the new function is static,
17200 // suppress the calling convention mismatch error; the error about static
17201 // function override (err_static_overrides_virtual from
17202 // Sema::CheckFunctionDeclaration) is more clear.
17203 if (New->getStorageClass() == SC_Static)
17204 return false;
17205
17206 Diag(New->getLocation(),
17207 diag::err_conflicting_overriding_cc_attributes)
17208 << New->getDeclName() << New->getType() << Old->getType();
17209 Diag(Old->getLocation(), diag::note_overridden_virtual_function);
17210 return true;
17211}
17212
17213bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
17214 const CXXMethodDecl *Old) {
17215 QualType NewTy = New->getType()->castAs<FunctionType>()->getReturnType();
17216 QualType OldTy = Old->getType()->castAs<FunctionType>()->getReturnType();
17217
17218 if (Context.hasSameType(NewTy, OldTy) ||
17219 NewTy->isDependentType() || OldTy->isDependentType())
17220 return false;
17221
17222 // Check if the return types are covariant
17223 QualType NewClassTy, OldClassTy;
17224
17225 /// Both types must be pointers or references to classes.
17226 if (const PointerType *NewPT = NewTy->getAs<PointerType>()) {
17227 if (const PointerType *OldPT = OldTy->getAs<PointerType>()) {
17228 NewClassTy = NewPT->getPointeeType();
17229 OldClassTy = OldPT->getPointeeType();
17230 }
17231 } else if (const ReferenceType *NewRT = NewTy->getAs<ReferenceType>()) {
17232 if (const ReferenceType *OldRT = OldTy->getAs<ReferenceType>()) {
17233 if (NewRT->getTypeClass() == OldRT->getTypeClass()) {
17234 NewClassTy = NewRT->getPointeeType();
17235 OldClassTy = OldRT->getPointeeType();
17236 }
17237 }
17238 }
17239
17240 // The return types aren't either both pointers or references to a class type.
17241 if (NewClassTy.isNull()) {
17242 Diag(New->getLocation(),
17243 diag::err_different_return_type_for_overriding_virtual_function)
17244 << New->getDeclName() << NewTy << OldTy
17245 << New->getReturnTypeSourceRange();
17246 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
17247 << Old->getReturnTypeSourceRange();
17248
17249 return true;
17250 }
17251
17252 if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) {
17253 // C++14 [class.virtual]p8:
17254 // If the class type in the covariant return type of D::f differs from
17255 // that of B::f, the class type in the return type of D::f shall be
17256 // complete at the point of declaration of D::f or shall be the class
17257 // type D.
17258 if (const RecordType *RT = NewClassTy->getAs<RecordType>()) {
17259 if (!RT->isBeingDefined() &&
17260 RequireCompleteType(New->getLocation(), NewClassTy,
17261 diag::err_covariant_return_incomplete,
17262 New->getDeclName()))
17263 return true;
17264 }
17265
17266 // Check if the new class derives from the old class.
17267 if (!IsDerivedFrom(New->getLocation(), NewClassTy, OldClassTy)) {
17268 Diag(New->getLocation(), diag::err_covariant_return_not_derived)
17269 << New->getDeclName() << NewTy << OldTy
17270 << New->getReturnTypeSourceRange();
17271 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
17272 << Old->getReturnTypeSourceRange();
17273 return true;
17274 }
17275
17276 // Check if we the conversion from derived to base is valid.
17277 if (CheckDerivedToBaseConversion(
17278 NewClassTy, OldClassTy,
17279 diag::err_covariant_return_inaccessible_base,
17280 diag::err_covariant_return_ambiguous_derived_to_base_conv,
17281 New->getLocation(), New->getReturnTypeSourceRange(),
17282 New->getDeclName(), nullptr)) {
17283 // FIXME: this note won't trigger for delayed access control
17284 // diagnostics, and it's impossible to get an undelayed error
17285 // here from access control during the original parse because
17286 // the ParsingDeclSpec/ParsingDeclarator are still in scope.
17287 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
17288 << Old->getReturnTypeSourceRange();
17289 return true;
17290 }
17291 }
17292
17293 // The qualifiers of the return types must be the same.
17294 if (NewTy.getLocalCVRQualifiers() != OldTy.getLocalCVRQualifiers()) {
17295 Diag(New->getLocation(),
17296 diag::err_covariant_return_type_different_qualifications)
17297 << New->getDeclName() << NewTy << OldTy
17298 << New->getReturnTypeSourceRange();
17299 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
17300 << Old->getReturnTypeSourceRange();
17301 return true;
17302 }
17303
17304
17305 // The new class type must have the same or less qualifiers as the old type.
17306 if (NewClassTy.isMoreQualifiedThan(OldClassTy)) {
17307 Diag(New->getLocation(),
17308 diag::err_covariant_return_type_class_type_more_qualified)
17309 << New->getDeclName() << NewTy << OldTy
17310 << New->getReturnTypeSourceRange();
17311 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
17312 << Old->getReturnTypeSourceRange();
17313 return true;
17314 }
17315
17316 return false;
17317}
17318
17319/// Mark the given method pure.
17320///
17321/// \param Method the method to be marked pure.
17322///
17323/// \param InitRange the source range that covers the "0" initializer.
17324bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) {
17325 SourceLocation EndLoc = InitRange.getEnd();
17326 if (EndLoc.isValid())
17327 Method->setRangeEnd(EndLoc);
17328
17329 if (Method->isVirtual() || Method->getParent()->isDependentContext()) {
17330 Method->setPure();
17331 return false;
17332 }
17333
17334 if (!Method->isInvalidDecl())
17335 Diag(Method->getLocation(), diag::err_non_virtual_pure)
17336 << Method->getDeclName() << InitRange;
17337 return true;
17338}
17339
17340void Sema::ActOnPureSpecifier(Decl *D, SourceLocation ZeroLoc) {
17341 if (D->getFriendObjectKind())
17342 Diag(D->getLocation(), diag::err_pure_friend);
17343 else if (auto *M = dyn_cast<CXXMethodDecl>(D))
17344 CheckPureMethod(M, ZeroLoc);
17345 else
17346 Diag(D->getLocation(), diag::err_illegal_initializer);
17347}
17348
17349/// Determine whether the given declaration is a global variable or
17350/// static data member.
17351static bool isNonlocalVariable(const Decl *D) {
17352 if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(D))
17353 return Var->hasGlobalStorage();
17354
17355 return false;
17356}
17357
17358/// Invoked when we are about to parse an initializer for the declaration
17359/// 'Dcl'.
17360///
17361/// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
17362/// static data member of class X, names should be looked up in the scope of
17363/// class X. If the declaration had a scope specifier, a scope will have
17364/// been created and passed in for this purpose. Otherwise, S will be null.
17365void Sema::ActOnCXXEnterDeclInitializer(Scope *S, Decl *D) {
17366 // If there is no declaration, there was an error parsing it.
17367 if (!D || D->isInvalidDecl())
17368 return;
17369
17370 // We will always have a nested name specifier here, but this declaration
17371 // might not be out of line if the specifier names the current namespace:
17372 // extern int n;
17373 // int ::n = 0;
17374 if (S && D->isOutOfLine())
17375 EnterDeclaratorContext(S, D->getDeclContext());
17376
17377 // If we are parsing the initializer for a static data member, push a
17378 // new expression evaluation context that is associated with this static
17379 // data member.
17380 if (isNonlocalVariable(D))
17381 PushExpressionEvaluationContext(
17382 ExpressionEvaluationContext::PotentiallyEvaluated, D);
17383}
17384
17385/// Invoked after we are finished parsing an initializer for the declaration D.
17386void Sema::ActOnCXXExitDeclInitializer(Scope *S, Decl *D) {
17387 // If there is no declaration, there was an error parsing it.
17388 if (!D || D->isInvalidDecl())
17389 return;
17390
17391 if (isNonlocalVariable(D))
17392 PopExpressionEvaluationContext();
17393
17394 if (S && D->isOutOfLine())
17395 ExitDeclaratorContext(S);
17396}
17397
17398/// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a
17399/// C++ if/switch/while/for statement.
17400/// e.g: "if (int x = f()) {...}"
17401DeclResult Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) {
17402 // C++ 6.4p2:
17403 // The declarator shall not specify a function or an array.
17404 // The type-specifier-seq shall not contain typedef and shall not declare a
17405 // new class or enumeration.
17406 assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&((void)0)
17407 "Parser allowed 'typedef' as storage class of condition decl.")((void)0);
17408
17409 Decl *Dcl = ActOnDeclarator(S, D);
17410 if (!Dcl)
17411 return true;
17412
17413 if (isa<FunctionDecl>(Dcl)) { // The declarator shall not specify a function.
17414 Diag(Dcl->getLocation(), diag::err_invalid_use_of_function_type)
17415 << D.getSourceRange();
17416 return true;
17417 }
17418
17419 return Dcl;
17420}
17421
17422void Sema::LoadExternalVTableUses() {
17423 if (!ExternalSource)
17424 return;
17425
17426 SmallVector<ExternalVTableUse, 4> VTables;
17427 ExternalSource->ReadUsedVTables(VTables);
17428 SmallVector<VTableUse, 4> NewUses;
17429 for (unsigned I = 0, N = VTables.size(); I != N; ++I) {
17430 llvm::DenseMap<CXXRecordDecl *, bool>::iterator Pos
17431 = VTablesUsed.find(VTables[I].Record);
17432 // Even if a definition wasn't required before, it may be required now.
17433 if (Pos != VTablesUsed.end()) {
17434 if (!Pos->second && VTables[I].DefinitionRequired)
17435 Pos->second = true;
17436 continue;
17437 }
17438
17439 VTablesUsed[VTables[I].Record] = VTables[I].DefinitionRequired;
17440 NewUses.push_back(VTableUse(VTables[I].Record, VTables[I].Location));
17441 }
17442
17443 VTableUses.insert(VTableUses.begin(), NewUses.begin(), NewUses.end());
17444}
17445
17446void Sema::MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
17447 bool DefinitionRequired) {
17448 // Ignore any vtable uses in unevaluated operands or for classes that do
17449 // not have a vtable.
17450 if (!Class->isDynamicClass() || Class->isDependentContext() ||
17451 CurContext->isDependentContext() || isUnevaluatedContext())
17452 return;
17453 // Do not mark as used if compiling for the device outside of the target
17454 // region.
17455 if (TUKind != TU_Prefix && LangOpts.OpenMP && LangOpts.OpenMPIsDevice &&
17456 !isInOpenMPDeclareTargetContext() &&
17457 !isInOpenMPTargetExecutionDirective()) {
17458 if (!DefinitionRequired)
17459 MarkVirtualMembersReferenced(Loc, Class);
17460 return;
17461 }
17462
17463 // Try to insert this class into the map.
17464 LoadExternalVTableUses();
17465 Class = Class->getCanonicalDecl();
17466 std::pair<llvm::DenseMap<CXXRecordDecl *, bool>::iterator, bool>
17467 Pos = VTablesUsed.insert(std::make_pair(Class, DefinitionRequired));
17468 if (!Pos.second) {
17469 // If we already had an entry, check to see if we are promoting this vtable
17470 // to require a definition. If so, we need to reappend to the VTableUses
17471 // list, since we may have already processed the first entry.
17472 if (DefinitionRequired && !Pos.first->second) {
17473 Pos.first->second = true;
17474 } else {
17475 // Otherwise, we can early exit.
17476 return;
17477 }
17478 } else {
17479 // The Microsoft ABI requires that we perform the destructor body
17480 // checks (i.e. operator delete() lookup) when the vtable is marked used, as
17481 // the deleting destructor is emitted with the vtable, not with the
17482 // destructor definition as in the Itanium ABI.
17483 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
17484 CXXDestructorDecl *DD = Class->getDestructor();
17485 if (DD && DD->isVirtual() && !DD->isDeleted()) {
17486 if (Class->hasUserDeclaredDestructor() && !DD->isDefined()) {
17487 // If this is an out-of-line declaration, marking it referenced will
17488 // not do anything. Manually call CheckDestructor to look up operator
17489 // delete().
17490 ContextRAII SavedContext(*this, DD);
17491 CheckDestructor(DD);
17492 } else {
17493 MarkFunctionReferenced(Loc, Class->getDestructor());
17494 }
17495 }
17496 }
17497 }
17498
17499 // Local classes need to have their virtual members marked
17500 // immediately. For all other classes, we mark their virtual members
17501 // at the end of the translation unit.
17502 if (Class->isLocalClass())
17503 MarkVirtualMembersReferenced(Loc, Class);
17504 else
17505 VTableUses.push_back(std::make_pair(Class, Loc));
17506}
17507
17508bool Sema::DefineUsedVTables() {
17509 LoadExternalVTableUses();
17510 if (VTableUses.empty())
17511 return false;
17512
17513 // Note: The VTableUses vector could grow as a result of marking
17514 // the members of a class as "used", so we check the size each
17515 // time through the loop and prefer indices (which are stable) to
17516 // iterators (which are not).
17517 bool DefinedAnything = false;
17518 for (unsigned I = 0; I != VTableUses.size(); ++I) {
17519 CXXRecordDecl *Class = VTableUses[I].first->getDefinition();
17520 if (!Class)
17521 continue;
17522 TemplateSpecializationKind ClassTSK =
17523 Class->getTemplateSpecializationKind();
17524
17525 SourceLocation Loc = VTableUses[I].second;
17526
17527 bool DefineVTable = true;
17528
17529 // If this class has a key function, but that key function is
17530 // defined in another translation unit, we don't need to emit the
17531 // vtable even though we're using it.
17532 const CXXMethodDecl *KeyFunction = Context.getCurrentKeyFunction(Class);
17533 if (KeyFunction && !KeyFunction->hasBody()) {
17534 // The key function is in another translation unit.
17535 DefineVTable = false;
17536 TemplateSpecializationKind TSK =
17537 KeyFunction->getTemplateSpecializationKind();
17538 assert(TSK != TSK_ExplicitInstantiationDefinition &&((void)0)
17539 TSK != TSK_ImplicitInstantiation &&((void)0)
17540 "Instantiations don't have key functions")((void)0);
17541 (void)TSK;
17542 } else if (!KeyFunction) {
17543 // If we have a class with no key function that is the subject
17544 // of an explicit instantiation declaration, suppress the
17545 // vtable; it will live with the explicit instantiation
17546 // definition.
17547 bool IsExplicitInstantiationDeclaration =
17548 ClassTSK == TSK_ExplicitInstantiationDeclaration;
17549 for (auto R : Class->redecls()) {
17550 TemplateSpecializationKind TSK
17551 = cast<CXXRecordDecl>(R)->getTemplateSpecializationKind();
17552 if (TSK == TSK_ExplicitInstantiationDeclaration)
17553 IsExplicitInstantiationDeclaration = true;
17554 else if (TSK == TSK_ExplicitInstantiationDefinition) {
17555 IsExplicitInstantiationDeclaration = false;
17556 break;
17557 }
17558 }
17559
17560 if (IsExplicitInstantiationDeclaration)
17561 DefineVTable = false;
17562 }
17563
17564 // The exception specifications for all virtual members may be needed even
17565 // if we are not providing an authoritative form of the vtable in this TU.
17566 // We may choose to emit it available_externally anyway.
17567 if (!DefineVTable) {
17568 MarkVirtualMemberExceptionSpecsNeeded(Loc, Class);
17569 continue;
17570 }
17571
17572 // Mark all of the virtual members of this class as referenced, so
17573 // that we can build a vtable. Then, tell the AST consumer that a
17574 // vtable for this class is required.
17575 DefinedAnything = true;
17576 MarkVirtualMembersReferenced(Loc, Class);
17577 CXXRecordDecl *Canonical = Class->getCanonicalDecl();
17578 if (VTablesUsed[Canonical])
17579 Consumer.HandleVTable(Class);
17580
17581 // Warn if we're emitting a weak vtable. The vtable will be weak if there is
17582 // no key function or the key function is inlined. Don't warn in C++ ABIs
17583 // that lack key functions, since the user won't be able to make one.
17584 if (Context.getTargetInfo().getCXXABI().hasKeyFunctions() &&
17585 Class->isExternallyVisible() && ClassTSK != TSK_ImplicitInstantiation) {
17586 const FunctionDecl *KeyFunctionDef = nullptr;
17587 if (!KeyFunction || (KeyFunction->hasBody(KeyFunctionDef) &&
17588 KeyFunctionDef->isInlined())) {
17589 Diag(Class->getLocation(),
17590 ClassTSK == TSK_ExplicitInstantiationDefinition
17591 ? diag::warn_weak_template_vtable
17592 : diag::warn_weak_vtable)
17593 << Class;
17594 }
17595 }
17596 }
17597 VTableUses.clear();
17598
17599 return DefinedAnything;
17600}
17601
17602void Sema::MarkVirtualMemberExceptionSpecsNeeded(SourceLocation Loc,
17603 const CXXRecordDecl *RD) {
17604 for (const auto *I : RD->methods())
17605 if (I->isVirtual() && !I->isPure())
17606 ResolveExceptionSpec(Loc, I->getType()->castAs<FunctionProtoType>());
17607}
17608
17609void Sema::MarkVirtualMembersReferenced(SourceLocation Loc,
17610 const CXXRecordDecl *RD,
17611 bool ConstexprOnly) {
17612 // Mark all functions which will appear in RD's vtable as used.
17613 CXXFinalOverriderMap FinalOverriders;
17614 RD->getFinalOverriders(FinalOverriders);
17615 for (CXXFinalOverriderMap::const_iterator I = FinalOverriders.begin(),
17616 E = FinalOverriders.end();
17617 I != E; ++I) {
17618 for (OverridingMethods::const_iterator OI = I->second.begin(),
17619 OE = I->second.end();
17620 OI != OE; ++OI) {
17621 assert(OI->second.size() > 0 && "no final overrider")((void)0);
17622 CXXMethodDecl *Overrider = OI->second.front().Method;
17623
17624 // C++ [basic.def.odr]p2:
17625 // [...] A virtual member function is used if it is not pure. [...]
17626 if (!Overrider->isPure() && (!ConstexprOnly || Overrider->isConstexpr()))
17627 MarkFunctionReferenced(Loc, Overrider);
17628 }
17629 }
17630
17631 // Only classes that have virtual bases need a VTT.
17632 if (RD->getNumVBases() == 0)
17633 return;
17634
17635 for (const auto &I : RD->bases()) {
17636 const auto *Base =
17637 cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
17638 if (Base->getNumVBases() == 0)
17639 continue;
17640 MarkVirtualMembersReferenced(Loc, Base);
17641 }
17642}
17643
17644/// SetIvarInitializers - This routine builds initialization ASTs for the
17645/// Objective-C implementation whose ivars need be initialized.
17646void Sema::SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation) {
17647 if (!getLangOpts().CPlusPlus)
17648 return;
17649 if (ObjCInterfaceDecl *OID = ObjCImplementation->getClassInterface()) {
17650 SmallVector<ObjCIvarDecl*, 8> ivars;
17651 CollectIvarsToConstructOrDestruct(OID, ivars);
17652 if (ivars.empty())
17653 return;
17654 SmallVector<CXXCtorInitializer*, 32> AllToInit;
17655 for (unsigned i = 0; i < ivars.size(); i++) {
17656 FieldDecl *Field = ivars[i];
17657 if (Field->isInvalidDecl())
17658 continue;
17659
17660 CXXCtorInitializer *Member;
17661 InitializedEntity InitEntity = InitializedEntity::InitializeMember(Field);
17662 InitializationKind InitKind =
17663 InitializationKind::CreateDefault(ObjCImplementation->getLocation());
17664
17665 InitializationSequence InitSeq(*this, InitEntity, InitKind, None);
17666 ExprResult MemberInit =
17667 InitSeq.Perform(*this, InitEntity, InitKind, None);
17668 MemberInit = MaybeCreateExprWithCleanups(MemberInit);
17669 // Note, MemberInit could actually come back empty if no initialization
17670 // is required (e.g., because it would call a trivial default constructor)
17671 if (!MemberInit.get() || MemberInit.isInvalid())
17672 continue;
17673
17674 Member =
17675 new (Context) CXXCtorInitializer(Context, Field, SourceLocation(),
17676 SourceLocation(),
17677 MemberInit.getAs<Expr>(),
17678 SourceLocation());
17679 AllToInit.push_back(Member);
17680
17681 // Be sure that the destructor is accessible and is marked as referenced.
17682 if (const RecordType *RecordTy =
17683 Context.getBaseElementType(Field->getType())
17684 ->getAs<RecordType>()) {
17685 CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
17686 if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
17687 MarkFunctionReferenced(Field->getLocation(), Destructor);
17688 CheckDestructorAccess(Field->getLocation(), Destructor,
17689 PDiag(diag::err_access_dtor_ivar)
17690 << Context.getBaseElementType(Field->getType()));
17691 }
17692 }
17693 }
17694 ObjCImplementation->setIvarInitializers(Context,
17695 AllToInit.data(), AllToInit.size());
17696 }
17697}
17698
17699static
17700void DelegatingCycleHelper(CXXConstructorDecl* Ctor,
17701 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Valid,
17702 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Invalid,
17703 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Current,
17704 Sema &S) {
17705 if (Ctor->isInvalidDecl())
17706 return;
17707
17708 CXXConstructorDecl *Target = Ctor->getTargetConstructor();
17709
17710 // Target may not be determinable yet, for instance if this is a dependent
17711 // call in an uninstantiated template.
17712 if (Target) {
17713 const FunctionDecl *FNTarget = nullptr;
17714 (void)Target->hasBody(FNTarget);
17715 Target = const_cast<CXXConstructorDecl*>(
17716 cast_or_null<CXXConstructorDecl>(FNTarget));
17717 }
17718
17719 CXXConstructorDecl *Canonical = Ctor->getCanonicalDecl(),
17720 // Avoid dereferencing a null pointer here.
17721 *TCanonical = Target? Target->getCanonicalDecl() : nullptr;
17722
17723 if (!Current.insert(Canonical).second)
17724 return;
17725
17726 // We know that beyond here, we aren't chaining into a cycle.
17727 if (!Target || !Target->isDelegatingConstructor() ||
17728 Target->isInvalidDecl() || Valid.count(TCanonical)) {
17729 Valid.insert(Current.begin(), Current.end());
17730 Current.clear();
17731 // We've hit a cycle.
17732 } else if (TCanonical == Canonical || Invalid.count(TCanonical) ||
17733 Current.count(TCanonical)) {
17734 // If we haven't diagnosed this cycle yet, do so now.
17735 if (!Invalid.count(TCanonical)) {
17736 S.Diag((*Ctor->init_begin())->getSourceLocation(),
17737 diag::warn_delegating_ctor_cycle)
17738 << Ctor;
17739
17740 // Don't add a note for a function delegating directly to itself.
17741 if (TCanonical != Canonical)
17742 S.Diag(Target->getLocation(), diag::note_it_delegates_to);
17743
17744 CXXConstructorDecl *C = Target;
17745 while (C->getCanonicalDecl() != Canonical) {
17746 const FunctionDecl *FNTarget = nullptr;
17747 (void)C->getTargetConstructor()->hasBody(FNTarget);
17748 assert(FNTarget && "Ctor cycle through bodiless function")((void)0);
17749
17750 C = const_cast<CXXConstructorDecl*>(
17751 cast<CXXConstructorDecl>(FNTarget));
17752 S.Diag(C->getLocation(), diag::note_which_delegates_to);
17753 }
17754 }
17755
17756 Invalid.insert(Current.begin(), Current.end());
17757 Current.clear();
17758 } else {
17759 DelegatingCycleHelper(Target, Valid, Invalid, Current, S);
17760 }
17761}
17762
17763
17764void Sema::CheckDelegatingCtorCycles() {
17765 llvm::SmallPtrSet<CXXConstructorDecl*, 4> Valid, Invalid, Current;
17766
17767 for (DelegatingCtorDeclsType::iterator
17768 I = DelegatingCtorDecls.begin(ExternalSource),
17769 E = DelegatingCtorDecls.end();
17770 I != E; ++I)
17771 DelegatingCycleHelper(*I, Valid, Invalid, Current, *this);
17772
17773 for (auto CI = Invalid.begin(), CE = Invalid.end(); CI != CE; ++CI)
17774 (*CI)->setInvalidDecl();
17775}
17776
17777namespace {
17778 /// AST visitor that finds references to the 'this' expression.
17779 class FindCXXThisExpr : public RecursiveASTVisitor<FindCXXThisExpr> {
17780 Sema &S;
17781
17782 public:
17783 explicit FindCXXThisExpr(Sema &S) : S(S) { }
17784
17785 bool VisitCXXThisExpr(CXXThisExpr *E) {
17786 S.Diag(E->getLocation(), diag::err_this_static_member_func)
17787 << E->isImplicit();
17788 return false;
17789 }
17790 };
17791}
17792
17793bool Sema::checkThisInStaticMemberFunctionType(CXXMethodDecl *Method) {
17794 TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
17795 if (!TSInfo)
17796 return false;
17797
17798 TypeLoc TL = TSInfo->getTypeLoc();
17799 FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>();
17800 if (!ProtoTL)
17801 return false;
17802
17803 // C++11 [expr.prim.general]p3:
17804 // [The expression this] shall not appear before the optional
17805 // cv-qualifier-seq and it shall not appear within the declaration of a
17806 // static member function (although its type and value category are defined
17807 // within a static member function as they are within a non-static member
17808 // function). [ Note: this is because declaration matching does not occur
17809 // until the complete declarator is known. - end note ]
17810 const FunctionProtoType *Proto = ProtoTL.getTypePtr();
17811 FindCXXThisExpr Finder(*this);
17812
17813 // If the return type came after the cv-qualifier-seq, check it now.
17814 if (Proto->hasTrailingReturn() &&
17815 !Finder.TraverseTypeLoc(ProtoTL.getReturnLoc()))
17816 return true;
17817
17818 // Check the exception specification.
17819 if (checkThisInStaticMemberFunctionExceptionSpec(Method))
17820 return true;
17821
17822 // Check the trailing requires clause
17823 if (Expr *E = Method->getTrailingRequiresClause())
17824 if (!Finder.TraverseStmt(E))
17825 return true;
17826
17827 return checkThisInStaticMemberFunctionAttributes(Method);
17828}
17829
17830bool Sema::checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method) {
17831 TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
17832 if (!TSInfo)
17833 return false;
17834
17835 TypeLoc TL = TSInfo->getTypeLoc();
17836 FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>();
17837 if (!ProtoTL)
17838 return false;
17839
17840 const FunctionProtoType *Proto = ProtoTL.getTypePtr();
17841 FindCXXThisExpr Finder(*this);
17842
17843 switch (Proto->getExceptionSpecType()) {
17844 case EST_Unparsed:
17845 case EST_Uninstantiated:
17846 case EST_Unevaluated:
17847 case EST_BasicNoexcept:
17848 case EST_NoThrow:
17849 case EST_DynamicNone:
17850 case EST_MSAny:
17851 case EST_None:
17852 break;
17853
17854 case EST_DependentNoexcept:
17855 case EST_NoexceptFalse:
17856 case EST_NoexceptTrue:
17857 if (!Finder.TraverseStmt(Proto->getNoexceptExpr()))
17858 return true;
17859 LLVM_FALLTHROUGH[[gnu::fallthrough]];
17860
17861 case EST_Dynamic:
17862 for (const auto &E : Proto->exceptions()) {
17863 if (!Finder.TraverseType(E))
17864 return true;
17865 }
17866 break;
17867 }
17868
17869 return false;
17870}
17871
17872bool Sema::checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method) {
17873 FindCXXThisExpr Finder(*this);
17874
17875 // Check attributes.
17876 for (const auto *A : Method->attrs()) {
17877 // FIXME: This should be emitted by tblgen.
17878 Expr *Arg = nullptr;
17879 ArrayRef<Expr *> Args;
17880 if (const auto *G = dyn_cast<GuardedByAttr>(A))
17881 Arg = G->getArg();
17882 else if (const auto *G = dyn_cast<PtGuardedByAttr>(A))
17883 Arg = G->getArg();
17884 else if (const auto *AA = dyn_cast<AcquiredAfterAttr>(A))
17885 Args = llvm::makeArrayRef(AA->args_begin(), AA->args_size());
17886 else if (const auto *AB = dyn_cast<AcquiredBeforeAttr>(A))
17887 Args = llvm::makeArrayRef(AB->args_begin(), AB->args_size());
17888 else if (const auto *ETLF = dyn_cast<ExclusiveTrylockFunctionAttr>(A)) {
17889 Arg = ETLF->getSuccessValue();
17890 Args = llvm::makeArrayRef(ETLF->args_begin(), ETLF->args_size());
17891 } else if (const auto *STLF = dyn_cast<SharedTrylockFunctionAttr>(A)) {
17892 Arg = STLF->getSuccessValue();
17893 Args = llvm::makeArrayRef(STLF->args_begin(), STLF->args_size());
17894 } else if (const auto *LR = dyn_cast<LockReturnedAttr>(A))
17895 Arg = LR->getArg();
17896 else if (const auto *LE = dyn_cast<LocksExcludedAttr>(A))
17897 Args = llvm::makeArrayRef(LE->args_begin(), LE->args_size());
17898 else if (const auto *RC = dyn_cast<RequiresCapabilityAttr>(A))
17899 Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size());
17900 else if (const auto *AC = dyn_cast<AcquireCapabilityAttr>(A))
17901 Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size());
17902 else if (const auto *AC = dyn_cast<TryAcquireCapabilityAttr>(A))
17903 Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size());
17904 else if (const auto *RC = dyn_cast<ReleaseCapabilityAttr>(A))
17905 Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size());
17906
17907 if (Arg && !Finder.TraverseStmt(Arg))
17908 return true;
17909
17910 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
17911 if (!Finder.TraverseStmt(Args[I]))
17912 return true;
17913 }
17914 }
17915
17916 return false;
17917}
17918
17919void Sema::checkExceptionSpecification(
17920 bool IsTopLevel, ExceptionSpecificationType EST,
17921 ArrayRef<ParsedType> DynamicExceptions,
17922 ArrayRef<SourceRange> DynamicExceptionRanges, Expr *NoexceptExpr,
17923 SmallVectorImpl<QualType> &Exceptions,
17924 FunctionProtoType::ExceptionSpecInfo &ESI) {
17925 Exceptions.clear();
17926 ESI.Type = EST;
17927 if (EST == EST_Dynamic) {
17928 Exceptions.reserve(DynamicExceptions.size());
17929 for (unsigned ei = 0, ee = DynamicExceptions.size(); ei != ee; ++ei) {
17930 // FIXME: Preserve type source info.
17931 QualType ET = GetTypeFromParser(DynamicExceptions[ei]);
17932
17933 if (IsTopLevel) {
17934 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
17935 collectUnexpandedParameterPacks(ET, Unexpanded);
17936 if (!Unexpanded.empty()) {
17937 DiagnoseUnexpandedParameterPacks(
17938 DynamicExceptionRanges[ei].getBegin(), UPPC_ExceptionType,
17939 Unexpanded);
17940 continue;
17941 }
17942 }
17943
17944 // Check that the type is valid for an exception spec, and
17945 // drop it if not.
17946 if (!CheckSpecifiedExceptionType(ET, DynamicExceptionRanges[ei]))
17947 Exceptions.push_back(ET);
17948 }
17949 ESI.Exceptions = Exceptions;
17950 return;
17951 }
17952
17953 if (isComputedNoexcept(EST)) {
17954 assert((NoexceptExpr->isTypeDependent() ||((void)0)
17955 NoexceptExpr->getType()->getCanonicalTypeUnqualified() ==((void)0)
17956 Context.BoolTy) &&((void)0)
17957 "Parser should have made sure that the expression is boolean")((void)0);
17958 if (IsTopLevel && DiagnoseUnexpandedParameterPack(NoexceptExpr)) {
17959 ESI.Type = EST_BasicNoexcept;
17960 return;
17961 }
17962
17963 ESI.NoexceptExpr = NoexceptExpr;
17964 return;
17965 }
17966}
17967
17968void Sema::actOnDelayedExceptionSpecification(Decl *MethodD,
17969 ExceptionSpecificationType EST,
17970 SourceRange SpecificationRange,
17971 ArrayRef<ParsedType> DynamicExceptions,
17972 ArrayRef<SourceRange> DynamicExceptionRanges,
17973 Expr *NoexceptExpr) {
17974 if (!MethodD)
17975 return;
17976
17977 // Dig out the method we're referring to.
17978 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(MethodD))
17979 MethodD = FunTmpl->getTemplatedDecl();
17980
17981 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(MethodD);
17982 if (!Method)
17983 return;
17984
17985 // Check the exception specification.
17986 llvm::SmallVector<QualType, 4> Exceptions;
17987 FunctionProtoType::ExceptionSpecInfo ESI;
17988 checkExceptionSpecification(/*IsTopLevel*/true, EST, DynamicExceptions,
17989 DynamicExceptionRanges, NoexceptExpr, Exceptions,
17990 ESI);
17991
17992 // Update the exception specification on the function type.
17993 Context.adjustExceptionSpec(Method, ESI, /*AsWritten*/true);
17994
17995 if (Method->isStatic())
17996 checkThisInStaticMemberFunctionExceptionSpec(Method);
17997
17998 if (Method->isVirtual()) {
17999 // Check overrides, which we previously had to delay.
18000 for (const CXXMethodDecl *O : Method->overridden_methods())
18001 CheckOverridingFunctionExceptionSpec(Method, O);
18002 }
18003}
18004
18005/// HandleMSProperty - Analyze a __delcspec(property) field of a C++ class.
18006///
18007MSPropertyDecl *Sema::HandleMSProperty(Scope *S, RecordDecl *Record,
18008 SourceLocation DeclStart, Declarator &D,
18009 Expr *BitWidth,
18010 InClassInitStyle InitStyle,
18011 AccessSpecifier AS,
18012 const ParsedAttr &MSPropertyAttr) {
18013 IdentifierInfo *II = D.getIdentifier();
18014 if (!II) {
18015 Diag(DeclStart, diag::err_anonymous_property);
18016 return nullptr;
18017 }
18018 SourceLocation Loc = D.getIdentifierLoc();
18019
18020 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
18021 QualType T = TInfo->getType();
18022 if (getLangOpts().CPlusPlus) {
18023 CheckExtraCXXDefaultArguments(D);
18024
18025 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
18026 UPPC_DataMemberType)) {
18027 D.setInvalidType();
18028 T = Context.IntTy;
18029 TInfo = Context.getTrivialTypeSourceInfo(T, Loc);
18030 }
18031 }
18032
18033 DiagnoseFunctionSpecifiers(D.getDeclSpec());
18034
18035 if (D.getDeclSpec().isInlineSpecified())
18036 Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
18037 << getLangOpts().CPlusPlus17;
18038 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
18039 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
18040 diag::err_invalid_thread)
18041 << DeclSpec::getSpecifierName(TSCS);
18042
18043 // Check to see if this name was declared as a member previously
18044 NamedDecl *PrevDecl = nullptr;
18045 LookupResult Previous(*this, II, Loc, LookupMemberName,
18046 ForVisibleRedeclaration);
18047 LookupName(Previous, S);
18048 switch (Previous.getResultKind()) {
18049 case LookupResult::Found:
18050 case LookupResult::FoundUnresolvedValue:
18051 PrevDecl = Previous.getAsSingle<NamedDecl>();
18052 break;
18053
18054 case LookupResult::FoundOverloaded:
18055 PrevDecl = Previous.getRepresentativeDecl();
18056 break;
18057
18058 case LookupResult::NotFound:
18059 case LookupResult::NotFoundInCurrentInstantiation:
18060 case LookupResult::Ambiguous:
18061 break;
18062 }
18063
18064 if (PrevDecl && PrevDecl->isTemplateParameter()) {
18065 // Maybe we will complain about the shadowed template parameter.
18066 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
18067 // Just pretend that we didn't see the previous declaration.
18068 PrevDecl = nullptr;
18069 }
18070
18071 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S))
18072 PrevDecl = nullptr;
18073
18074 SourceLocation TSSL = D.getBeginLoc();
18075 MSPropertyDecl *NewPD =
18076 MSPropertyDecl::Create(Context, Record, Loc, II, T, TInfo, TSSL,
18077 MSPropertyAttr.getPropertyDataGetter(),
18078 MSPropertyAttr.getPropertyDataSetter());
18079 ProcessDeclAttributes(TUScope, NewPD, D);
18080 NewPD->setAccess(AS);
18081
18082 if (NewPD->isInvalidDecl())
18083 Record->setInvalidDecl();
18084
18085 if (D.getDeclSpec().isModulePrivateSpecified())
18086 NewPD->setModulePrivate();
18087
18088 if (NewPD->isInvalidDecl() && PrevDecl) {
18089 // Don't introduce NewFD into scope; there's already something
18090 // with the same name in the same scope.
18091 } else if (II) {
18092 PushOnScopeChains(NewPD, S);
18093 } else
18094 Record->addDecl(NewPD);
18095
18096 return NewPD;
18097}
18098
18099void Sema::ActOnStartFunctionDeclarationDeclarator(
18100 Declarator &Declarator, unsigned TemplateParameterDepth) {
18101 auto &Info = InventedParameterInfos.emplace_back();
18102 TemplateParameterList *ExplicitParams = nullptr;
18103 ArrayRef<TemplateParameterList *> ExplicitLists =
18104 Declarator.getTemplateParameterLists();
18105 if (!ExplicitLists.empty()) {
18106 bool IsMemberSpecialization, IsInvalid;
18107 ExplicitParams = MatchTemplateParametersToScopeSpecifier(
18108 Declarator.getBeginLoc(), Declarator.getIdentifierLoc(),
18109 Declarator.getCXXScopeSpec(), /*TemplateId=*/nullptr,
18110 ExplicitLists, /*IsFriend=*/false, IsMemberSpecialization, IsInvalid,
18111 /*SuppressDiagnostic=*/true);
18112 }
18113 if (ExplicitParams) {
18114 Info.AutoTemplateParameterDepth = ExplicitParams->getDepth();
18115 for (NamedDecl *Param : *ExplicitParams)
18116 Info.TemplateParams.push_back(Param);
18117 Info.NumExplicitTemplateParams = ExplicitParams->size();
18118 } else {
18119 Info.AutoTemplateParameterDepth = TemplateParameterDepth;
18120 Info.NumExplicitTemplateParams = 0;
18121 }
18122}
18123
18124void Sema::ActOnFinishFunctionDeclarationDeclarator(Declarator &Declarator) {
18125 auto &FSI = InventedParameterInfos.back();
18126 if (FSI.TemplateParams.size() > FSI.NumExplicitTemplateParams) {
18127 if (FSI.NumExplicitTemplateParams != 0) {
18128 TemplateParameterList *ExplicitParams =
18129 Declarator.getTemplateParameterLists().back();
18130 Declarator.setInventedTemplateParameterList(
18131 TemplateParameterList::Create(
18132 Context, ExplicitParams->getTemplateLoc(),
18133 ExplicitParams->getLAngleLoc(), FSI.TemplateParams,
18134 ExplicitParams->getRAngleLoc(),
18135 ExplicitParams->getRequiresClause()));
18136 } else {
18137 Declarator.setInventedTemplateParameterList(
18138 TemplateParameterList::Create(
18139 Context, SourceLocation(), SourceLocation(), FSI.TemplateParams,
18140 SourceLocation(), /*RequiresClause=*/nullptr));
18141 }
18142 }
18143 InventedParameterInfos.pop_back();
18144}