Bug Summary

File:src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaInit.cpp
Warning:line 3913, column 7
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 SemaInit.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/SemaInit.cpp

/usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaInit.cpp

→
1//===--- SemaInit.cpp - Semantic Analysis for Initializers ----------------===//
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 initializers.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/AST/ASTContext.h"
14#include "clang/AST/DeclObjC.h"
15#include "clang/AST/ExprCXX.h"
16#include "clang/AST/ExprObjC.h"
17#include "clang/AST/ExprOpenMP.h"
18#include "clang/AST/TypeLoc.h"
19#include "clang/Basic/CharInfo.h"
20#include "clang/Basic/SourceManager.h"
21#include "clang/Basic/TargetInfo.h"
22#include "clang/Sema/Designator.h"
23#include "clang/Sema/Initialization.h"
24#include "clang/Sema/Lookup.h"
25#include "clang/Sema/SemaInternal.h"
26#include "llvm/ADT/APInt.h"
27#include "llvm/ADT/PointerIntPair.h"
28#include "llvm/ADT/SmallString.h"
29#include "llvm/Support/ErrorHandling.h"
30#include "llvm/Support/raw_ostream.h"
31
32using namespace clang;
33
34//===----------------------------------------------------------------------===//
35// Sema Initialization Checking
36//===----------------------------------------------------------------------===//
37
38/// Check whether T is compatible with a wide character type (wchar_t,
39/// char16_t or char32_t).
40static bool IsWideCharCompatible(QualType T, ASTContext &Context) {
41 if (Context.typesAreCompatible(Context.getWideCharType(), T))
42 return true;
43 if (Context.getLangOpts().CPlusPlus || Context.getLangOpts().C11) {
44 return Context.typesAreCompatible(Context.Char16Ty, T) ||
45 Context.typesAreCompatible(Context.Char32Ty, T);
46 }
47 return false;
48}
49
50enum StringInitFailureKind {
51 SIF_None,
52 SIF_NarrowStringIntoWideChar,
53 SIF_WideStringIntoChar,
54 SIF_IncompatWideStringIntoWideChar,
55 SIF_UTF8StringIntoPlainChar,
56 SIF_PlainStringIntoUTF8Char,
57 SIF_Other
58};
59
60/// Check whether the array of type AT can be initialized by the Init
61/// expression by means of string initialization. Returns SIF_None if so,
62/// otherwise returns a StringInitFailureKind that describes why the
63/// initialization would not work.
64static StringInitFailureKind IsStringInit(Expr *Init, const ArrayType *AT,
65 ASTContext &Context) {
66 if (!isa<ConstantArrayType>(AT) && !isa<IncompleteArrayType>(AT))
67 return SIF_Other;
68
69 // See if this is a string literal or @encode.
70 Init = Init->IgnoreParens();
71
72 // Handle @encode, which is a narrow string.
73 if (isa<ObjCEncodeExpr>(Init) && AT->getElementType()->isCharType())
74 return SIF_None;
75
76 // Otherwise we can only handle string literals.
77 StringLiteral *SL = dyn_cast<StringLiteral>(Init);
78 if (!SL)
79 return SIF_Other;
80
81 const QualType ElemTy =
82 Context.getCanonicalType(AT->getElementType()).getUnqualifiedType();
83
84 switch (SL->getKind()) {
85 case StringLiteral::UTF8:
86 // char8_t array can be initialized with a UTF-8 string.
87 if (ElemTy->isChar8Type())
88 return SIF_None;
89 LLVM_FALLTHROUGH[[gnu::fallthrough]];
90 case StringLiteral::Ascii:
91 // char array can be initialized with a narrow string.
92 // Only allow char x[] = "foo"; not char x[] = L"foo";
93 if (ElemTy->isCharType())
94 return (SL->getKind() == StringLiteral::UTF8 &&
95 Context.getLangOpts().Char8)
96 ? SIF_UTF8StringIntoPlainChar
97 : SIF_None;
98 if (ElemTy->isChar8Type())
99 return SIF_PlainStringIntoUTF8Char;
100 if (IsWideCharCompatible(ElemTy, Context))
101 return SIF_NarrowStringIntoWideChar;
102 return SIF_Other;
103 // C99 6.7.8p15 (with correction from DR343), or C11 6.7.9p15:
104 // "An array with element type compatible with a qualified or unqualified
105 // version of wchar_t, char16_t, or char32_t may be initialized by a wide
106 // string literal with the corresponding encoding prefix (L, u, or U,
107 // respectively), optionally enclosed in braces.
108 case StringLiteral::UTF16:
109 if (Context.typesAreCompatible(Context.Char16Ty, ElemTy))
110 return SIF_None;
111 if (ElemTy->isCharType() || ElemTy->isChar8Type())
112 return SIF_WideStringIntoChar;
113 if (IsWideCharCompatible(ElemTy, Context))
114 return SIF_IncompatWideStringIntoWideChar;
115 return SIF_Other;
116 case StringLiteral::UTF32:
117 if (Context.typesAreCompatible(Context.Char32Ty, ElemTy))
118 return SIF_None;
119 if (ElemTy->isCharType() || ElemTy->isChar8Type())
120 return SIF_WideStringIntoChar;
121 if (IsWideCharCompatible(ElemTy, Context))
122 return SIF_IncompatWideStringIntoWideChar;
123 return SIF_Other;
124 case StringLiteral::Wide:
125 if (Context.typesAreCompatible(Context.getWideCharType(), ElemTy))
126 return SIF_None;
127 if (ElemTy->isCharType() || ElemTy->isChar8Type())
128 return SIF_WideStringIntoChar;
129 if (IsWideCharCompatible(ElemTy, Context))
130 return SIF_IncompatWideStringIntoWideChar;
131 return SIF_Other;
132 }
133
134 llvm_unreachable("missed a StringLiteral kind?")__builtin_unreachable();
135}
136
137static StringInitFailureKind IsStringInit(Expr *init, QualType declType,
138 ASTContext &Context) {
139 const ArrayType *arrayType = Context.getAsArrayType(declType);
140 if (!arrayType)
141 return SIF_Other;
142 return IsStringInit(init, arrayType, Context);
143}
144
145bool Sema::IsStringInit(Expr *Init, const ArrayType *AT) {
146 return ::IsStringInit(Init, AT, Context) == SIF_None;
147}
148
149/// Update the type of a string literal, including any surrounding parentheses,
150/// to match the type of the object which it is initializing.
151static void updateStringLiteralType(Expr *E, QualType Ty) {
152 while (true) {
153 E->setType(Ty);
154 E->setValueKind(VK_PRValue);
155 if (isa<StringLiteral>(E) || isa<ObjCEncodeExpr>(E)) {
156 break;
157 } else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
158 E = PE->getSubExpr();
159 } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
160 assert(UO->getOpcode() == UO_Extension)((void)0);
161 E = UO->getSubExpr();
162 } else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) {
163 E = GSE->getResultExpr();
164 } else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(E)) {
165 E = CE->getChosenSubExpr();
166 } else {
167 llvm_unreachable("unexpected expr in string literal init")__builtin_unreachable();
168 }
169 }
170}
171
172/// Fix a compound literal initializing an array so it's correctly marked
173/// as an rvalue.
174static void updateGNUCompoundLiteralRValue(Expr *E) {
175 while (true) {
176 E->setValueKind(VK_PRValue);
177 if (isa<CompoundLiteralExpr>(E)) {
178 break;
179 } else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
180 E = PE->getSubExpr();
181 } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
182 assert(UO->getOpcode() == UO_Extension)((void)0);
183 E = UO->getSubExpr();
184 } else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) {
185 E = GSE->getResultExpr();
186 } else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(E)) {
187 E = CE->getChosenSubExpr();
188 } else {
189 llvm_unreachable("unexpected expr in array compound literal init")__builtin_unreachable();
190 }
191 }
192}
193
194static void CheckStringInit(Expr *Str, QualType &DeclT, const ArrayType *AT,
195 Sema &S) {
196 // Get the length of the string as parsed.
197 auto *ConstantArrayTy =
198 cast<ConstantArrayType>(Str->getType()->getAsArrayTypeUnsafe());
199 uint64_t StrLength = ConstantArrayTy->getSize().getZExtValue();
200
201 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) {
202 // C99 6.7.8p14. We have an array of character type with unknown size
203 // being initialized to a string literal.
204 llvm::APInt ConstVal(32, StrLength);
205 // Return a new array type (C99 6.7.8p22).
206 DeclT = S.Context.getConstantArrayType(IAT->getElementType(),
207 ConstVal, nullptr,
208 ArrayType::Normal, 0);
209 updateStringLiteralType(Str, DeclT);
210 return;
211 }
212
213 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT);
214
215 // We have an array of character type with known size. However,
216 // the size may be smaller or larger than the string we are initializing.
217 // FIXME: Avoid truncation for 64-bit length strings.
218 if (S.getLangOpts().CPlusPlus) {
219 if (StringLiteral *SL = dyn_cast<StringLiteral>(Str->IgnoreParens())) {
220 // For Pascal strings it's OK to strip off the terminating null character,
221 // so the example below is valid:
222 //
223 // unsigned char a[2] = "\pa";
224 if (SL->isPascal())
225 StrLength--;
226 }
227
228 // [dcl.init.string]p2
229 if (StrLength > CAT->getSize().getZExtValue())
230 S.Diag(Str->getBeginLoc(),
231 diag::err_initializer_string_for_char_array_too_long)
232 << Str->getSourceRange();
233 } else {
234 // C99 6.7.8p14.
235 if (StrLength-1 > CAT->getSize().getZExtValue())
236 S.Diag(Str->getBeginLoc(),
237 diag::ext_initializer_string_for_char_array_too_long)
238 << Str->getSourceRange();
239 }
240
241 // Set the type to the actual size that we are initializing. If we have
242 // something like:
243 // char x[1] = "foo";
244 // then this will set the string literal's type to char[1].
245 updateStringLiteralType(Str, DeclT);
246}
247
248//===----------------------------------------------------------------------===//
249// Semantic checking for initializer lists.
250//===----------------------------------------------------------------------===//
251
252namespace {
253
254/// Semantic checking for initializer lists.
255///
256/// The InitListChecker class contains a set of routines that each
257/// handle the initialization of a certain kind of entity, e.g.,
258/// arrays, vectors, struct/union types, scalars, etc. The
259/// InitListChecker itself performs a recursive walk of the subobject
260/// structure of the type to be initialized, while stepping through
261/// the initializer list one element at a time. The IList and Index
262/// parameters to each of the Check* routines contain the active
263/// (syntactic) initializer list and the index into that initializer
264/// list that represents the current initializer. Each routine is
265/// responsible for moving that Index forward as it consumes elements.
266///
267/// Each Check* routine also has a StructuredList/StructuredIndex
268/// arguments, which contains the current "structured" (semantic)
269/// initializer list and the index into that initializer list where we
270/// are copying initializers as we map them over to the semantic
271/// list. Once we have completed our recursive walk of the subobject
272/// structure, we will have constructed a full semantic initializer
273/// list.
274///
275/// C99 designators cause changes in the initializer list traversal,
276/// because they make the initialization "jump" into a specific
277/// subobject and then continue the initialization from that
278/// point. CheckDesignatedInitializer() recursively steps into the
279/// designated subobject and manages backing out the recursion to
280/// initialize the subobjects after the one designated.
281///
282/// If an initializer list contains any designators, we build a placeholder
283/// structured list even in 'verify only' mode, so that we can track which
284/// elements need 'empty' initializtion.
285class InitListChecker {
286 Sema &SemaRef;
287 bool hadError = false;
288 bool VerifyOnly; // No diagnostics.
289 bool TreatUnavailableAsInvalid; // Used only in VerifyOnly mode.
290 bool InOverloadResolution;
291 InitListExpr *FullyStructuredList = nullptr;
292 NoInitExpr *DummyExpr = nullptr;
293
294 NoInitExpr *getDummyInit() {
295 if (!DummyExpr)
296 DummyExpr = new (SemaRef.Context) NoInitExpr(SemaRef.Context.VoidTy);
297 return DummyExpr;
298 }
299
300 void CheckImplicitInitList(const InitializedEntity &Entity,
301 InitListExpr *ParentIList, QualType T,
302 unsigned &Index, InitListExpr *StructuredList,
303 unsigned &StructuredIndex);
304 void CheckExplicitInitList(const InitializedEntity &Entity,
305 InitListExpr *IList, QualType &T,
306 InitListExpr *StructuredList,
307 bool TopLevelObject = false);
308 void CheckListElementTypes(const InitializedEntity &Entity,
309 InitListExpr *IList, QualType &DeclType,
310 bool SubobjectIsDesignatorContext,
311 unsigned &Index,
312 InitListExpr *StructuredList,
313 unsigned &StructuredIndex,
314 bool TopLevelObject = false);
315 void CheckSubElementType(const InitializedEntity &Entity,
316 InitListExpr *IList, QualType ElemType,
317 unsigned &Index,
318 InitListExpr *StructuredList,
319 unsigned &StructuredIndex,
320 bool DirectlyDesignated = false);
321 void CheckComplexType(const InitializedEntity &Entity,
322 InitListExpr *IList, QualType DeclType,
323 unsigned &Index,
324 InitListExpr *StructuredList,
325 unsigned &StructuredIndex);
326 void CheckScalarType(const InitializedEntity &Entity,
327 InitListExpr *IList, QualType DeclType,
328 unsigned &Index,
329 InitListExpr *StructuredList,
330 unsigned &StructuredIndex);
331 void CheckReferenceType(const InitializedEntity &Entity,
332 InitListExpr *IList, QualType DeclType,
333 unsigned &Index,
334 InitListExpr *StructuredList,
335 unsigned &StructuredIndex);
336 void CheckVectorType(const InitializedEntity &Entity,
337 InitListExpr *IList, QualType DeclType, unsigned &Index,
338 InitListExpr *StructuredList,
339 unsigned &StructuredIndex);
340 void CheckStructUnionTypes(const InitializedEntity &Entity,
341 InitListExpr *IList, QualType DeclType,
342 CXXRecordDecl::base_class_range Bases,
343 RecordDecl::field_iterator Field,
344 bool SubobjectIsDesignatorContext, unsigned &Index,
345 InitListExpr *StructuredList,
346 unsigned &StructuredIndex,
347 bool TopLevelObject = false);
348 void CheckArrayType(const InitializedEntity &Entity,
349 InitListExpr *IList, QualType &DeclType,
350 llvm::APSInt elementIndex,
351 bool SubobjectIsDesignatorContext, unsigned &Index,
352 InitListExpr *StructuredList,
353 unsigned &StructuredIndex);
354 bool CheckDesignatedInitializer(const InitializedEntity &Entity,
355 InitListExpr *IList, DesignatedInitExpr *DIE,
356 unsigned DesigIdx,
357 QualType &CurrentObjectType,
358 RecordDecl::field_iterator *NextField,
359 llvm::APSInt *NextElementIndex,
360 unsigned &Index,
361 InitListExpr *StructuredList,
362 unsigned &StructuredIndex,
363 bool FinishSubobjectInit,
364 bool TopLevelObject);
365 InitListExpr *getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
366 QualType CurrentObjectType,
367 InitListExpr *StructuredList,
368 unsigned StructuredIndex,
369 SourceRange InitRange,
370 bool IsFullyOverwritten = false);
371 void UpdateStructuredListElement(InitListExpr *StructuredList,
372 unsigned &StructuredIndex,
373 Expr *expr);
374 InitListExpr *createInitListExpr(QualType CurrentObjectType,
375 SourceRange InitRange,
376 unsigned ExpectedNumInits);
377 int numArrayElements(QualType DeclType);
378 int numStructUnionElements(QualType DeclType);
379
380 ExprResult PerformEmptyInit(SourceLocation Loc,
381 const InitializedEntity &Entity);
382
383 /// Diagnose that OldInit (or part thereof) has been overridden by NewInit.
384 void diagnoseInitOverride(Expr *OldInit, SourceRange NewInitRange,
385 bool FullyOverwritten = true) {
386 // Overriding an initializer via a designator is valid with C99 designated
387 // initializers, but ill-formed with C++20 designated initializers.
388 unsigned DiagID = SemaRef.getLangOpts().CPlusPlus
389 ? diag::ext_initializer_overrides
390 : diag::warn_initializer_overrides;
391
392 if (InOverloadResolution && SemaRef.getLangOpts().CPlusPlus) {
393 // In overload resolution, we have to strictly enforce the rules, and so
394 // don't allow any overriding of prior initializers. This matters for a
395 // case such as:
396 //
397 // union U { int a, b; };
398 // struct S { int a, b; };
399 // void f(U), f(S);
400 //
401 // Here, f({.a = 1, .b = 2}) is required to call the struct overload. For
402 // consistency, we disallow all overriding of prior initializers in
403 // overload resolution, not only overriding of union members.
404 hadError = true;
405 } else if (OldInit->getType().isDestructedType() && !FullyOverwritten) {
406 // If we'll be keeping around the old initializer but overwriting part of
407 // the object it initialized, and that object is not trivially
408 // destructible, this can leak. Don't allow that, not even as an
409 // extension.
410 //
411 // FIXME: It might be reasonable to allow this in cases where the part of
412 // the initializer that we're overriding has trivial destruction.
413 DiagID = diag::err_initializer_overrides_destructed;
414 } else if (!OldInit->getSourceRange().isValid()) {
415 // We need to check on source range validity because the previous
416 // initializer does not have to be an explicit initializer. e.g.,
417 //
418 // struct P { int a, b; };
419 // struct PP { struct P p } l = { { .a = 2 }, .p.b = 3 };
420 //
421 // There is an overwrite taking place because the first braced initializer
422 // list "{ .a = 2 }" already provides value for .p.b (which is zero).
423 //
424 // Such overwrites are harmless, so we don't diagnose them. (Note that in
425 // C++, this cannot be reached unless we've already seen and diagnosed a
426 // different conformance issue, such as a mixture of designated and
427 // non-designated initializers or a multi-level designator.)
428 return;
429 }
430
431 if (!VerifyOnly) {
432 SemaRef.Diag(NewInitRange.getBegin(), DiagID)
433 << NewInitRange << FullyOverwritten << OldInit->getType();
434 SemaRef.Diag(OldInit->getBeginLoc(), diag::note_previous_initializer)
435 << (OldInit->HasSideEffects(SemaRef.Context) && FullyOverwritten)
436 << OldInit->getSourceRange();
437 }
438 }
439
440 // Explanation on the "FillWithNoInit" mode:
441 //
442 // Assume we have the following definitions (Case#1):
443 // struct P { char x[6][6]; } xp = { .x[1] = "bar" };
444 // struct PP { struct P lp; } l = { .lp = xp, .lp.x[1][2] = 'f' };
445 //
446 // l.lp.x[1][0..1] should not be filled with implicit initializers because the
447 // "base" initializer "xp" will provide values for them; l.lp.x[1] will be "baf".
448 //
449 // But if we have (Case#2):
450 // struct PP l = { .lp = xp, .lp.x[1] = { [2] = 'f' } };
451 //
452 // l.lp.x[1][0..1] are implicitly initialized and do not use values from the
453 // "base" initializer; l.lp.x[1] will be "\0\0f\0\0\0".
454 //
455 // To distinguish Case#1 from Case#2, and also to avoid leaving many "holes"
456 // in the InitListExpr, the "holes" in Case#1 are filled not with empty
457 // initializers but with special "NoInitExpr" place holders, which tells the
458 // CodeGen not to generate any initializers for these parts.
459 void FillInEmptyInitForBase(unsigned Init, const CXXBaseSpecifier &Base,
460 const InitializedEntity &ParentEntity,
461 InitListExpr *ILE, bool &RequiresSecondPass,
462 bool FillWithNoInit);
463 void FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
464 const InitializedEntity &ParentEntity,
465 InitListExpr *ILE, bool &RequiresSecondPass,
466 bool FillWithNoInit = false);
467 void FillInEmptyInitializations(const InitializedEntity &Entity,
468 InitListExpr *ILE, bool &RequiresSecondPass,
469 InitListExpr *OuterILE, unsigned OuterIndex,
470 bool FillWithNoInit = false);
471 bool CheckFlexibleArrayInit(const InitializedEntity &Entity,
472 Expr *InitExpr, FieldDecl *Field,
473 bool TopLevelObject);
474 void CheckEmptyInitializable(const InitializedEntity &Entity,
475 SourceLocation Loc);
476
477public:
478 InitListChecker(Sema &S, const InitializedEntity &Entity, InitListExpr *IL,
479 QualType &T, bool VerifyOnly, bool TreatUnavailableAsInvalid,
480 bool InOverloadResolution = false);
481 bool HadError() { return hadError; }
482
483 // Retrieves the fully-structured initializer list used for
484 // semantic analysis and code generation.
485 InitListExpr *getFullyStructuredList() const { return FullyStructuredList; }
486};
487
488} // end anonymous namespace
489
490ExprResult InitListChecker::PerformEmptyInit(SourceLocation Loc,
491 const InitializedEntity &Entity) {
492 InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc,
493 true);
494 MultiExprArg SubInit;
495 Expr *InitExpr;
496 InitListExpr DummyInitList(SemaRef.Context, Loc, None, Loc);
497
498 // C++ [dcl.init.aggr]p7:
499 // If there are fewer initializer-clauses in the list than there are
500 // members in the aggregate, then each member not explicitly initialized
501 // ...
502 bool EmptyInitList = SemaRef.getLangOpts().CPlusPlus11 &&
503 Entity.getType()->getBaseElementTypeUnsafe()->isRecordType();
504 if (EmptyInitList) {
505 // C++1y / DR1070:
506 // shall be initialized [...] from an empty initializer list.
507 //
508 // We apply the resolution of this DR to C++11 but not C++98, since C++98
509 // does not have useful semantics for initialization from an init list.
510 // We treat this as copy-initialization, because aggregate initialization
511 // always performs copy-initialization on its elements.
512 //
513 // Only do this if we're initializing a class type, to avoid filling in
514 // the initializer list where possible.
515 InitExpr = VerifyOnly ? &DummyInitList : new (SemaRef.Context)
516 InitListExpr(SemaRef.Context, Loc, None, Loc);
517 InitExpr->setType(SemaRef.Context.VoidTy);
518 SubInit = InitExpr;
519 Kind = InitializationKind::CreateCopy(Loc, Loc);
520 } else {
521 // C++03:
522 // shall be value-initialized.
523 }
524
525 InitializationSequence InitSeq(SemaRef, Entity, Kind, SubInit);
526 // libstdc++4.6 marks the vector default constructor as explicit in
527 // _GLIBCXX_DEBUG mode, so recover using the C++03 logic in that case.
528 // stlport does so too. Look for std::__debug for libstdc++, and for
529 // std:: for stlport. This is effectively a compiler-side implementation of
530 // LWG2193.
531 if (!InitSeq && EmptyInitList && InitSeq.getFailureKind() ==
532 InitializationSequence::FK_ExplicitConstructor) {
533 OverloadCandidateSet::iterator Best;
534 OverloadingResult O =
535 InitSeq.getFailedCandidateSet()
536 .BestViableFunction(SemaRef, Kind.getLocation(), Best);
537 (void)O;
538 assert(O == OR_Success && "Inconsistent overload resolution")((void)0);
539 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
540 CXXRecordDecl *R = CtorDecl->getParent();
541
542 if (CtorDecl->getMinRequiredArguments() == 0 &&
543 CtorDecl->isExplicit() && R->getDeclName() &&
544 SemaRef.SourceMgr.isInSystemHeader(CtorDecl->getLocation())) {
545 bool IsInStd = false;
546 for (NamespaceDecl *ND = dyn_cast<NamespaceDecl>(R->getDeclContext());
547 ND && !IsInStd; ND = dyn_cast<NamespaceDecl>(ND->getParent())) {
548 if (SemaRef.getStdNamespace()->InEnclosingNamespaceSetOf(ND))
549 IsInStd = true;
550 }
551
552 if (IsInStd && llvm::StringSwitch<bool>(R->getName())
553 .Cases("basic_string", "deque", "forward_list", true)
554 .Cases("list", "map", "multimap", "multiset", true)
555 .Cases("priority_queue", "queue", "set", "stack", true)
556 .Cases("unordered_map", "unordered_set", "vector", true)
557 .Default(false)) {
558 InitSeq.InitializeFrom(
559 SemaRef, Entity,
560 InitializationKind::CreateValue(Loc, Loc, Loc, true),
561 MultiExprArg(), /*TopLevelOfInitList=*/false,
562 TreatUnavailableAsInvalid);
563 // Emit a warning for this. System header warnings aren't shown
564 // by default, but people working on system headers should see it.
565 if (!VerifyOnly) {
566 SemaRef.Diag(CtorDecl->getLocation(),
567 diag::warn_invalid_initializer_from_system_header);
568 if (Entity.getKind() == InitializedEntity::EK_Member)
569 SemaRef.Diag(Entity.getDecl()->getLocation(),
570 diag::note_used_in_initialization_here);
571 else if (Entity.getKind() == InitializedEntity::EK_ArrayElement)
572 SemaRef.Diag(Loc, diag::note_used_in_initialization_here);
573 }
574 }
575 }
576 }
577 if (!InitSeq) {
578 if (!VerifyOnly) {
579 InitSeq.Diagnose(SemaRef, Entity, Kind, SubInit);
580 if (Entity.getKind() == InitializedEntity::EK_Member)
581 SemaRef.Diag(Entity.getDecl()->getLocation(),
582 diag::note_in_omitted_aggregate_initializer)
583 << /*field*/1 << Entity.getDecl();
584 else if (Entity.getKind() == InitializedEntity::EK_ArrayElement) {
585 bool IsTrailingArrayNewMember =
586 Entity.getParent() &&
587 Entity.getParent()->isVariableLengthArrayNew();
588 SemaRef.Diag(Loc, diag::note_in_omitted_aggregate_initializer)
589 << (IsTrailingArrayNewMember ? 2 : /*array element*/0)
590 << Entity.getElementIndex();
591 }
592 }
593 hadError = true;
594 return ExprError();
595 }
596
597 return VerifyOnly ? ExprResult()
598 : InitSeq.Perform(SemaRef, Entity, Kind, SubInit);
599}
600
601void InitListChecker::CheckEmptyInitializable(const InitializedEntity &Entity,
602 SourceLocation Loc) {
603 // If we're building a fully-structured list, we'll check this at the end
604 // once we know which elements are actually initialized. Otherwise, we know
605 // that there are no designators so we can just check now.
606 if (FullyStructuredList)
607 return;
608 PerformEmptyInit(Loc, Entity);
609}
610
611void InitListChecker::FillInEmptyInitForBase(
612 unsigned Init, const CXXBaseSpecifier &Base,
613 const InitializedEntity &ParentEntity, InitListExpr *ILE,
614 bool &RequiresSecondPass, bool FillWithNoInit) {
615 InitializedEntity BaseEntity = InitializedEntity::InitializeBase(
616 SemaRef.Context, &Base, false, &ParentEntity);
617
618 if (Init >= ILE->getNumInits() || !ILE->getInit(Init)) {
619 ExprResult BaseInit = FillWithNoInit
620 ? new (SemaRef.Context) NoInitExpr(Base.getType())
621 : PerformEmptyInit(ILE->getEndLoc(), BaseEntity);
622 if (BaseInit.isInvalid()) {
623 hadError = true;
624 return;
625 }
626
627 if (!VerifyOnly) {
628 assert(Init < ILE->getNumInits() && "should have been expanded")((void)0);
629 ILE->setInit(Init, BaseInit.getAs<Expr>());
630 }
631 } else if (InitListExpr *InnerILE =
632 dyn_cast<InitListExpr>(ILE->getInit(Init))) {
633 FillInEmptyInitializations(BaseEntity, InnerILE, RequiresSecondPass,
634 ILE, Init, FillWithNoInit);
635 } else if (DesignatedInitUpdateExpr *InnerDIUE =
636 dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init))) {
637 FillInEmptyInitializations(BaseEntity, InnerDIUE->getUpdater(),
638 RequiresSecondPass, ILE, Init,
639 /*FillWithNoInit =*/true);
640 }
641}
642
643void InitListChecker::FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
644 const InitializedEntity &ParentEntity,
645 InitListExpr *ILE,
646 bool &RequiresSecondPass,
647 bool FillWithNoInit) {
648 SourceLocation Loc = ILE->getEndLoc();
649 unsigned NumInits = ILE->getNumInits();
650 InitializedEntity MemberEntity
651 = InitializedEntity::InitializeMember(Field, &ParentEntity);
652
653 if (Init >= NumInits || !ILE->getInit(Init)) {
654 if (const RecordType *RType = ILE->getType()->getAs<RecordType>())
655 if (!RType->getDecl()->isUnion())
656 assert((Init < NumInits || VerifyOnly) &&((void)0)
657 "This ILE should have been expanded")((void)0);
658
659 if (FillWithNoInit) {
660 assert(!VerifyOnly && "should not fill with no-init in verify-only mode")((void)0);
661 Expr *Filler = new (SemaRef.Context) NoInitExpr(Field->getType());
662 if (Init < NumInits)
663 ILE->setInit(Init, Filler);
664 else
665 ILE->updateInit(SemaRef.Context, Init, Filler);
666 return;
667 }
668 // C++1y [dcl.init.aggr]p7:
669 // If there are fewer initializer-clauses in the list than there are
670 // members in the aggregate, then each member not explicitly initialized
671 // shall be initialized from its brace-or-equal-initializer [...]
672 if (Field->hasInClassInitializer()) {
673 if (VerifyOnly)
674 return;
675
676 ExprResult DIE = SemaRef.BuildCXXDefaultInitExpr(Loc, Field);
677 if (DIE.isInvalid()) {
678 hadError = true;
679 return;
680 }
681 SemaRef.checkInitializerLifetime(MemberEntity, DIE.get());
682 if (Init < NumInits)
683 ILE->setInit(Init, DIE.get());
684 else {
685 ILE->updateInit(SemaRef.Context, Init, DIE.get());
686 RequiresSecondPass = true;
687 }
688 return;
689 }
690
691 if (Field->getType()->isReferenceType()) {
692 if (!VerifyOnly) {
693 // C++ [dcl.init.aggr]p9:
694 // If an incomplete or empty initializer-list leaves a
695 // member of reference type uninitialized, the program is
696 // ill-formed.
697 SemaRef.Diag(Loc, diag::err_init_reference_member_uninitialized)
698 << Field->getType()
699 << ILE->getSyntacticForm()->getSourceRange();
700 SemaRef.Diag(Field->getLocation(),
701 diag::note_uninit_reference_member);
702 }
703 hadError = true;
704 return;
705 }
706
707 ExprResult MemberInit = PerformEmptyInit(Loc, MemberEntity);
708 if (MemberInit.isInvalid()) {
709 hadError = true;
710 return;
711 }
712
713 if (hadError || VerifyOnly) {
714 // Do nothing
715 } else if (Init < NumInits) {
716 ILE->setInit(Init, MemberInit.getAs<Expr>());
717 } else if (!isa<ImplicitValueInitExpr>(MemberInit.get())) {
718 // Empty initialization requires a constructor call, so
719 // extend the initializer list to include the constructor
720 // call and make a note that we'll need to take another pass
721 // through the initializer list.
722 ILE->updateInit(SemaRef.Context, Init, MemberInit.getAs<Expr>());
723 RequiresSecondPass = true;
724 }
725 } else if (InitListExpr *InnerILE
726 = dyn_cast<InitListExpr>(ILE->getInit(Init))) {
727 FillInEmptyInitializations(MemberEntity, InnerILE,
728 RequiresSecondPass, ILE, Init, FillWithNoInit);
729 } else if (DesignatedInitUpdateExpr *InnerDIUE =
730 dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init))) {
731 FillInEmptyInitializations(MemberEntity, InnerDIUE->getUpdater(),
732 RequiresSecondPass, ILE, Init,
733 /*FillWithNoInit =*/true);
734 }
735}
736
737/// Recursively replaces NULL values within the given initializer list
738/// with expressions that perform value-initialization of the
739/// appropriate type, and finish off the InitListExpr formation.
740void
741InitListChecker::FillInEmptyInitializations(const InitializedEntity &Entity,
742 InitListExpr *ILE,
743 bool &RequiresSecondPass,
744 InitListExpr *OuterILE,
745 unsigned OuterIndex,
746 bool FillWithNoInit) {
747 assert((ILE->getType() != SemaRef.Context.VoidTy) &&((void)0)
748 "Should not have void type")((void)0);
749
750 // We don't need to do any checks when just filling NoInitExprs; that can't
751 // fail.
752 if (FillWithNoInit && VerifyOnly)
753 return;
754
755 // If this is a nested initializer list, we might have changed its contents
756 // (and therefore some of its properties, such as instantiation-dependence)
757 // while filling it in. Inform the outer initializer list so that its state
758 // can be updated to match.
759 // FIXME: We should fully build the inner initializers before constructing
760 // the outer InitListExpr instead of mutating AST nodes after they have
761 // been used as subexpressions of other nodes.
762 struct UpdateOuterILEWithUpdatedInit {
763 InitListExpr *Outer;
764 unsigned OuterIndex;
765 ~UpdateOuterILEWithUpdatedInit() {
766 if (Outer)
767 Outer->setInit(OuterIndex, Outer->getInit(OuterIndex));
768 }
769 } UpdateOuterRAII = {OuterILE, OuterIndex};
770
771 // A transparent ILE is not performing aggregate initialization and should
772 // not be filled in.
773 if (ILE->isTransparent())
774 return;
775
776 if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) {
777 const RecordDecl *RDecl = RType->getDecl();
778 if (RDecl->isUnion() && ILE->getInitializedFieldInUnion())
779 FillInEmptyInitForField(0, ILE->getInitializedFieldInUnion(),
780 Entity, ILE, RequiresSecondPass, FillWithNoInit);
781 else if (RDecl->isUnion() && isa<CXXRecordDecl>(RDecl) &&
782 cast<CXXRecordDecl>(RDecl)->hasInClassInitializer()) {
783 for (auto *Field : RDecl->fields()) {
784 if (Field->hasInClassInitializer()) {
785 FillInEmptyInitForField(0, Field, Entity, ILE, RequiresSecondPass,
786 FillWithNoInit);
787 break;
788 }
789 }
790 } else {
791 // The fields beyond ILE->getNumInits() are default initialized, so in
792 // order to leave them uninitialized, the ILE is expanded and the extra
793 // fields are then filled with NoInitExpr.
794 unsigned NumElems = numStructUnionElements(ILE->getType());
795 if (RDecl->hasFlexibleArrayMember())
796 ++NumElems;
797 if (!VerifyOnly && ILE->getNumInits() < NumElems)
798 ILE->resizeInits(SemaRef.Context, NumElems);
799
800 unsigned Init = 0;
801
802 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RDecl)) {
803 for (auto &Base : CXXRD->bases()) {
804 if (hadError)
805 return;
806
807 FillInEmptyInitForBase(Init, Base, Entity, ILE, RequiresSecondPass,
808 FillWithNoInit);
809 ++Init;
810 }
811 }
812
813 for (auto *Field : RDecl->fields()) {
814 if (Field->isUnnamedBitfield())
815 continue;
816
817 if (hadError)
818 return;
819
820 FillInEmptyInitForField(Init, Field, Entity, ILE, RequiresSecondPass,
821 FillWithNoInit);
822 if (hadError)
823 return;
824
825 ++Init;
826
827 // Only look at the first initialization of a union.
828 if (RDecl->isUnion())
829 break;
830 }
831 }
832
833 return;
834 }
835
836 QualType ElementType;
837
838 InitializedEntity ElementEntity = Entity;
839 unsigned NumInits = ILE->getNumInits();
840 unsigned NumElements = NumInits;
841 if (const ArrayType *AType = SemaRef.Context.getAsArrayType(ILE->getType())) {
842 ElementType = AType->getElementType();
843 if (const auto *CAType = dyn_cast<ConstantArrayType>(AType))
844 NumElements = CAType->getSize().getZExtValue();
845 // For an array new with an unknown bound, ask for one additional element
846 // in order to populate the array filler.
847 if (Entity.isVariableLengthArrayNew())
848 ++NumElements;
849 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context,
850 0, Entity);
851 } else if (const VectorType *VType = ILE->getType()->getAs<VectorType>()) {
852 ElementType = VType->getElementType();
853 NumElements = VType->getNumElements();
854 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context,
855 0, Entity);
856 } else
857 ElementType = ILE->getType();
858
859 bool SkipEmptyInitChecks = false;
860 for (unsigned Init = 0; Init != NumElements; ++Init) {
861 if (hadError)
862 return;
863
864 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement ||
865 ElementEntity.getKind() == InitializedEntity::EK_VectorElement)
866 ElementEntity.setElementIndex(Init);
867
868 if (Init >= NumInits && (ILE->hasArrayFiller() || SkipEmptyInitChecks))
869 return;
870
871 Expr *InitExpr = (Init < NumInits ? ILE->getInit(Init) : nullptr);
872 if (!InitExpr && Init < NumInits && ILE->hasArrayFiller())
873 ILE->setInit(Init, ILE->getArrayFiller());
874 else if (!InitExpr && !ILE->hasArrayFiller()) {
875 // In VerifyOnly mode, there's no point performing empty initialization
876 // more than once.
877 if (SkipEmptyInitChecks)
878 continue;
879
880 Expr *Filler = nullptr;
881
882 if (FillWithNoInit)
883 Filler = new (SemaRef.Context) NoInitExpr(ElementType);
884 else {
885 ExprResult ElementInit =
886 PerformEmptyInit(ILE->getEndLoc(), ElementEntity);
887 if (ElementInit.isInvalid()) {
888 hadError = true;
889 return;
890 }
891
892 Filler = ElementInit.getAs<Expr>();
893 }
894
895 if (hadError) {
896 // Do nothing
897 } else if (VerifyOnly) {
898 SkipEmptyInitChecks = true;
899 } else if (Init < NumInits) {
900 // For arrays, just set the expression used for value-initialization
901 // of the "holes" in the array.
902 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement)
903 ILE->setArrayFiller(Filler);
904 else
905 ILE->setInit(Init, Filler);
906 } else {
907 // For arrays, just set the expression used for value-initialization
908 // of the rest of elements and exit.
909 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement) {
910 ILE->setArrayFiller(Filler);
911 return;
912 }
913
914 if (!isa<ImplicitValueInitExpr>(Filler) && !isa<NoInitExpr>(Filler)) {
915 // Empty initialization requires a constructor call, so
916 // extend the initializer list to include the constructor
917 // call and make a note that we'll need to take another pass
918 // through the initializer list.
919 ILE->updateInit(SemaRef.Context, Init, Filler);
920 RequiresSecondPass = true;
921 }
922 }
923 } else if (InitListExpr *InnerILE
924 = dyn_cast_or_null<InitListExpr>(InitExpr)) {
925 FillInEmptyInitializations(ElementEntity, InnerILE, RequiresSecondPass,
926 ILE, Init, FillWithNoInit);
927 } else if (DesignatedInitUpdateExpr *InnerDIUE =
928 dyn_cast_or_null<DesignatedInitUpdateExpr>(InitExpr)) {
929 FillInEmptyInitializations(ElementEntity, InnerDIUE->getUpdater(),
930 RequiresSecondPass, ILE, Init,
931 /*FillWithNoInit =*/true);
932 }
933 }
934}
935
936static bool hasAnyDesignatedInits(const InitListExpr *IL) {
937 for (const Stmt *Init : *IL)
938 if (Init && isa<DesignatedInitExpr>(Init))
939 return true;
940 return false;
941}
942
943InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity,
944 InitListExpr *IL, QualType &T, bool VerifyOnly,
945 bool TreatUnavailableAsInvalid,
946 bool InOverloadResolution)
947 : SemaRef(S), VerifyOnly(VerifyOnly),
948 TreatUnavailableAsInvalid(TreatUnavailableAsInvalid),
949 InOverloadResolution(InOverloadResolution) {
950 if (!VerifyOnly || hasAnyDesignatedInits(IL)) {
951 FullyStructuredList =
952 createInitListExpr(T, IL->getSourceRange(), IL->getNumInits());
953
954 // FIXME: Check that IL isn't already the semantic form of some other
955 // InitListExpr. If it is, we'd create a broken AST.
956 if (!VerifyOnly)
957 FullyStructuredList->setSyntacticForm(IL);
958 }
959
960 CheckExplicitInitList(Entity, IL, T, FullyStructuredList,
961 /*TopLevelObject=*/true);
962
963 if (!hadError && FullyStructuredList) {
964 bool RequiresSecondPass = false;
965 FillInEmptyInitializations(Entity, FullyStructuredList, RequiresSecondPass,
966 /*OuterILE=*/nullptr, /*OuterIndex=*/0);
967 if (RequiresSecondPass && !hadError)
968 FillInEmptyInitializations(Entity, FullyStructuredList,
969 RequiresSecondPass, nullptr, 0);
970 }
971 if (hadError && FullyStructuredList)
972 FullyStructuredList->markError();
973}
974
975int InitListChecker::numArrayElements(QualType DeclType) {
976 // FIXME: use a proper constant
977 int maxElements = 0x7FFFFFFF;
978 if (const ConstantArrayType *CAT =
979 SemaRef.Context.getAsConstantArrayType(DeclType)) {
980 maxElements = static_cast<int>(CAT->getSize().getZExtValue());
981 }
982 return maxElements;
983}
984
985int InitListChecker::numStructUnionElements(QualType DeclType) {
986 RecordDecl *structDecl = DeclType->castAs<RecordType>()->getDecl();
987 int InitializableMembers = 0;
988 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(structDecl))
989 InitializableMembers += CXXRD->getNumBases();
990 for (const auto *Field : structDecl->fields())
991 if (!Field->isUnnamedBitfield())
992 ++InitializableMembers;
993
994 if (structDecl->isUnion())
995 return std::min(InitializableMembers, 1);
996 return InitializableMembers - structDecl->hasFlexibleArrayMember();
997}
998
999/// Determine whether Entity is an entity for which it is idiomatic to elide
1000/// the braces in aggregate initialization.
1001static bool isIdiomaticBraceElisionEntity(const InitializedEntity &Entity) {
1002 // Recursive initialization of the one and only field within an aggregate
1003 // class is considered idiomatic. This case arises in particular for
1004 // initialization of std::array, where the C++ standard suggests the idiom of
1005 //
1006 // std::array<T, N> arr = {1, 2, 3};
1007 //
1008 // (where std::array is an aggregate struct containing a single array field.
1009
1010 if (!Entity.getParent())
1011 return false;
1012
1013 // Allows elide brace initialization for aggregates with empty base.
1014 if (Entity.getKind() == InitializedEntity::EK_Base) {
1015 auto *ParentRD =
1016 Entity.getParent()->getType()->castAs<RecordType>()->getDecl();
1017 CXXRecordDecl *CXXRD = cast<CXXRecordDecl>(ParentRD);
1018 return CXXRD->getNumBases() == 1 && CXXRD->field_empty();
1019 }
1020
1021 // Allow brace elision if the only subobject is a field.
1022 if (Entity.getKind() == InitializedEntity::EK_Member) {
1023 auto *ParentRD =
1024 Entity.getParent()->getType()->castAs<RecordType>()->getDecl();
1025 if (CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(ParentRD)) {
1026 if (CXXRD->getNumBases()) {
1027 return false;
1028 }
1029 }
1030 auto FieldIt = ParentRD->field_begin();
1031 assert(FieldIt != ParentRD->field_end() &&((void)0)
1032 "no fields but have initializer for member?")((void)0);
1033 return ++FieldIt == ParentRD->field_end();
1034 }
1035
1036 return false;
1037}
1038
1039/// Check whether the range of the initializer \p ParentIList from element
1040/// \p Index onwards can be used to initialize an object of type \p T. Update
1041/// \p Index to indicate how many elements of the list were consumed.
1042///
1043/// This also fills in \p StructuredList, from element \p StructuredIndex
1044/// onwards, with the fully-braced, desugared form of the initialization.
1045void InitListChecker::CheckImplicitInitList(const InitializedEntity &Entity,
1046 InitListExpr *ParentIList,
1047 QualType T, unsigned &Index,
1048 InitListExpr *StructuredList,
1049 unsigned &StructuredIndex) {
1050 int maxElements = 0;
1051
1052 if (T->isArrayType())
1053 maxElements = numArrayElements(T);
1054 else if (T->isRecordType())
1055 maxElements = numStructUnionElements(T);
1056 else if (T->isVectorType())
1057 maxElements = T->castAs<VectorType>()->getNumElements();
1058 else
1059 llvm_unreachable("CheckImplicitInitList(): Illegal type")__builtin_unreachable();
1060
1061 if (maxElements == 0) {
1062 if (!VerifyOnly)
1063 SemaRef.Diag(ParentIList->getInit(Index)->getBeginLoc(),
1064 diag::err_implicit_empty_initializer);
1065 ++Index;
1066 hadError = true;
1067 return;
1068 }
1069
1070 // Build a structured initializer list corresponding to this subobject.
1071 InitListExpr *StructuredSubobjectInitList = getStructuredSubobjectInit(
1072 ParentIList, Index, T, StructuredList, StructuredIndex,
1073 SourceRange(ParentIList->getInit(Index)->getBeginLoc(),
1074 ParentIList->getSourceRange().getEnd()));
1075 unsigned StructuredSubobjectInitIndex = 0;
1076
1077 // Check the element types and build the structural subobject.
1078 unsigned StartIndex = Index;
1079 CheckListElementTypes(Entity, ParentIList, T,
1080 /*SubobjectIsDesignatorContext=*/false, Index,
1081 StructuredSubobjectInitList,
1082 StructuredSubobjectInitIndex);
1083
1084 if (StructuredSubobjectInitList) {
1085 StructuredSubobjectInitList->setType(T);
1086
1087 unsigned EndIndex = (Index == StartIndex? StartIndex : Index - 1);
1088 // Update the structured sub-object initializer so that it's ending
1089 // range corresponds with the end of the last initializer it used.
1090 if (EndIndex < ParentIList->getNumInits() &&
1091 ParentIList->getInit(EndIndex)) {
1092 SourceLocation EndLoc
1093 = ParentIList->getInit(EndIndex)->getSourceRange().getEnd();
1094 StructuredSubobjectInitList->setRBraceLoc(EndLoc);
1095 }
1096
1097 // Complain about missing braces.
1098 if (!VerifyOnly && (T->isArrayType() || T->isRecordType()) &&
1099 !ParentIList->isIdiomaticZeroInitializer(SemaRef.getLangOpts()) &&
1100 !isIdiomaticBraceElisionEntity(Entity)) {
1101 SemaRef.Diag(StructuredSubobjectInitList->getBeginLoc(),
1102 diag::warn_missing_braces)
1103 << StructuredSubobjectInitList->getSourceRange()
1104 << FixItHint::CreateInsertion(
1105 StructuredSubobjectInitList->getBeginLoc(), "{")
1106 << FixItHint::CreateInsertion(
1107 SemaRef.getLocForEndOfToken(
1108 StructuredSubobjectInitList->getEndLoc()),
1109 "}");
1110 }
1111
1112 // Warn if this type won't be an aggregate in future versions of C++.
1113 auto *CXXRD = T->getAsCXXRecordDecl();
1114 if (!VerifyOnly && CXXRD && CXXRD->hasUserDeclaredConstructor()) {
1115 SemaRef.Diag(StructuredSubobjectInitList->getBeginLoc(),
1116 diag::warn_cxx20_compat_aggregate_init_with_ctors)
1117 << StructuredSubobjectInitList->getSourceRange() << T;
1118 }
1119 }
1120}
1121
1122/// Warn that \p Entity was of scalar type and was initialized by a
1123/// single-element braced initializer list.
1124static void warnBracedScalarInit(Sema &S, const InitializedEntity &Entity,
1125 SourceRange Braces) {
1126 // Don't warn during template instantiation. If the initialization was
1127 // non-dependent, we warned during the initial parse; otherwise, the
1128 // type might not be scalar in some uses of the template.
1129 if (S.inTemplateInstantiation())
1130 return;
1131
1132 unsigned DiagID = 0;
1133
1134 switch (Entity.getKind()) {
1135 case InitializedEntity::EK_VectorElement:
1136 case InitializedEntity::EK_ComplexElement:
1137 case InitializedEntity::EK_ArrayElement:
1138 case InitializedEntity::EK_Parameter:
1139 case InitializedEntity::EK_Parameter_CF_Audited:
1140 case InitializedEntity::EK_TemplateParameter:
1141 case InitializedEntity::EK_Result:
1142 // Extra braces here are suspicious.
1143 DiagID = diag::warn_braces_around_init;
1144 break;
1145
1146 case InitializedEntity::EK_Member:
1147 // Warn on aggregate initialization but not on ctor init list or
1148 // default member initializer.
1149 if (Entity.getParent())
1150 DiagID = diag::warn_braces_around_init;
1151 break;
1152
1153 case InitializedEntity::EK_Variable:
1154 case InitializedEntity::EK_LambdaCapture:
1155 // No warning, might be direct-list-initialization.
1156 // FIXME: Should we warn for copy-list-initialization in these cases?
1157 break;
1158
1159 case InitializedEntity::EK_New:
1160 case InitializedEntity::EK_Temporary:
1161 case InitializedEntity::EK_CompoundLiteralInit:
1162 // No warning, braces are part of the syntax of the underlying construct.
1163 break;
1164
1165 case InitializedEntity::EK_RelatedResult:
1166 // No warning, we already warned when initializing the result.
1167 break;
1168
1169 case InitializedEntity::EK_Exception:
1170 case InitializedEntity::EK_Base:
1171 case InitializedEntity::EK_Delegating:
1172 case InitializedEntity::EK_BlockElement:
1173 case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
1174 case InitializedEntity::EK_Binding:
1175 case InitializedEntity::EK_StmtExprResult:
1176 llvm_unreachable("unexpected braced scalar init")__builtin_unreachable();
1177 }
1178
1179 if (DiagID) {
1180 S.Diag(Braces.getBegin(), DiagID)
1181 << Entity.getType()->isSizelessBuiltinType() << Braces
1182 << FixItHint::CreateRemoval(Braces.getBegin())
1183 << FixItHint::CreateRemoval(Braces.getEnd());
1184 }
1185}
1186
1187/// Check whether the initializer \p IList (that was written with explicit
1188/// braces) can be used to initialize an object of type \p T.
1189///
1190/// This also fills in \p StructuredList with the fully-braced, desugared
1191/// form of the initialization.
1192void InitListChecker::CheckExplicitInitList(const InitializedEntity &Entity,
1193 InitListExpr *IList, QualType &T,
1194 InitListExpr *StructuredList,
1195 bool TopLevelObject) {
1196 unsigned Index = 0, StructuredIndex = 0;
1197 CheckListElementTypes(Entity, IList, T, /*SubobjectIsDesignatorContext=*/true,
1198 Index, StructuredList, StructuredIndex, TopLevelObject);
1199 if (StructuredList) {
1200 QualType ExprTy = T;
1201 if (!ExprTy->isArrayType())
1202 ExprTy = ExprTy.getNonLValueExprType(SemaRef.Context);
1203 if (!VerifyOnly)
1204 IList->setType(ExprTy);
1205 StructuredList->setType(ExprTy);
1206 }
1207 if (hadError)
1208 return;
1209
1210 // Don't complain for incomplete types, since we'll get an error elsewhere.
1211 if (Index < IList->getNumInits() && !T->isIncompleteType()) {
1212 // We have leftover initializers
1213 bool ExtraInitsIsError = SemaRef.getLangOpts().CPlusPlus ||
1214 (SemaRef.getLangOpts().OpenCL && T->isVectorType());
1215 hadError = ExtraInitsIsError;
1216 if (VerifyOnly) {
1217 return;
1218 } else if (StructuredIndex == 1 &&
1219 IsStringInit(StructuredList->getInit(0), T, SemaRef.Context) ==
1220 SIF_None) {
1221 unsigned DK =
1222 ExtraInitsIsError
1223 ? diag::err_excess_initializers_in_char_array_initializer
1224 : diag::ext_excess_initializers_in_char_array_initializer;
1225 SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
1226 << IList->getInit(Index)->getSourceRange();
1227 } else if (T->isSizelessBuiltinType()) {
1228 unsigned DK = ExtraInitsIsError
1229 ? diag::err_excess_initializers_for_sizeless_type
1230 : diag::ext_excess_initializers_for_sizeless_type;
1231 SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
1232 << T << IList->getInit(Index)->getSourceRange();
1233 } else {
1234 int initKind = T->isArrayType() ? 0 :
1235 T->isVectorType() ? 1 :
1236 T->isScalarType() ? 2 :
1237 T->isUnionType() ? 3 :
1238 4;
1239
1240 unsigned DK = ExtraInitsIsError ? diag::err_excess_initializers
1241 : diag::ext_excess_initializers;
1242 SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
1243 << initKind << IList->getInit(Index)->getSourceRange();
1244 }
1245 }
1246
1247 if (!VerifyOnly) {
1248 if (T->isScalarType() && IList->getNumInits() == 1 &&
1249 !isa<InitListExpr>(IList->getInit(0)))
1250 warnBracedScalarInit(SemaRef, Entity, IList->getSourceRange());
1251
1252 // Warn if this is a class type that won't be an aggregate in future
1253 // versions of C++.
1254 auto *CXXRD = T->getAsCXXRecordDecl();
1255 if (CXXRD && CXXRD->hasUserDeclaredConstructor()) {
1256 // Don't warn if there's an equivalent default constructor that would be
1257 // used instead.
1258 bool HasEquivCtor = false;
1259 if (IList->getNumInits() == 0) {
1260 auto *CD = SemaRef.LookupDefaultConstructor(CXXRD);
1261 HasEquivCtor = CD && !CD->isDeleted();
1262 }
1263
1264 if (!HasEquivCtor) {
1265 SemaRef.Diag(IList->getBeginLoc(),
1266 diag::warn_cxx20_compat_aggregate_init_with_ctors)
1267 << IList->getSourceRange() << T;
1268 }
1269 }
1270 }
1271}
1272
1273void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity,
1274 InitListExpr *IList,
1275 QualType &DeclType,
1276 bool SubobjectIsDesignatorContext,
1277 unsigned &Index,
1278 InitListExpr *StructuredList,
1279 unsigned &StructuredIndex,
1280 bool TopLevelObject) {
1281 if (DeclType->isAnyComplexType() && SubobjectIsDesignatorContext) {
1282 // Explicitly braced initializer for complex type can be real+imaginary
1283 // parts.
1284 CheckComplexType(Entity, IList, DeclType, Index,
1285 StructuredList, StructuredIndex);
1286 } else if (DeclType->isScalarType()) {
1287 CheckScalarType(Entity, IList, DeclType, Index,
1288 StructuredList, StructuredIndex);
1289 } else if (DeclType->isVectorType()) {
1290 CheckVectorType(Entity, IList, DeclType, Index,
1291 StructuredList, StructuredIndex);
1292 } else if (DeclType->isRecordType()) {
1293 assert(DeclType->isAggregateType() &&((void)0)
1294 "non-aggregate records should be handed in CheckSubElementType")((void)0);
1295 RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
1296 auto Bases =
1297 CXXRecordDecl::base_class_range(CXXRecordDecl::base_class_iterator(),
1298 CXXRecordDecl::base_class_iterator());
1299 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
1300 Bases = CXXRD->bases();
1301 CheckStructUnionTypes(Entity, IList, DeclType, Bases, RD->field_begin(),
1302 SubobjectIsDesignatorContext, Index, StructuredList,
1303 StructuredIndex, TopLevelObject);
1304 } else if (DeclType->isArrayType()) {
1305 llvm::APSInt Zero(
1306 SemaRef.Context.getTypeSize(SemaRef.Context.getSizeType()),
1307 false);
1308 CheckArrayType(Entity, IList, DeclType, Zero,
1309 SubobjectIsDesignatorContext, Index,
1310 StructuredList, StructuredIndex);
1311 } else if (DeclType->isVoidType() || DeclType->isFunctionType()) {
1312 // This type is invalid, issue a diagnostic.
1313 ++Index;
1314 if (!VerifyOnly)
1315 SemaRef.Diag(IList->getBeginLoc(), diag::err_illegal_initializer_type)
1316 << DeclType;
1317 hadError = true;
1318 } else if (DeclType->isReferenceType()) {
1319 CheckReferenceType(Entity, IList, DeclType, Index,
1320 StructuredList, StructuredIndex);
1321 } else if (DeclType->isObjCObjectType()) {
1322 if (!VerifyOnly)
1323 SemaRef.Diag(IList->getBeginLoc(), diag::err_init_objc_class) << DeclType;
1324 hadError = true;
1325 } else if (DeclType->isOCLIntelSubgroupAVCType() ||
1326 DeclType->isSizelessBuiltinType()) {
1327 // Checks for scalar type are sufficient for these types too.
1328 CheckScalarType(Entity, IList, DeclType, Index, StructuredList,
1329 StructuredIndex);
1330 } else {
1331 if (!VerifyOnly)
1332 SemaRef.Diag(IList->getBeginLoc(), diag::err_illegal_initializer_type)
1333 << DeclType;
1334 hadError = true;
1335 }
1336}
1337
1338void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
1339 InitListExpr *IList,
1340 QualType ElemType,
1341 unsigned &Index,
1342 InitListExpr *StructuredList,
1343 unsigned &StructuredIndex,
1344 bool DirectlyDesignated) {
1345 Expr *expr = IList->getInit(Index);
1346
1347 if (ElemType->isReferenceType())
1348 return CheckReferenceType(Entity, IList, ElemType, Index,
1349 StructuredList, StructuredIndex);
1350
1351 if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) {
1352 if (SubInitList->getNumInits() == 1 &&
1353 IsStringInit(SubInitList->getInit(0), ElemType, SemaRef.Context) ==
1354 SIF_None) {
1355 // FIXME: It would be more faithful and no less correct to include an
1356 // InitListExpr in the semantic form of the initializer list in this case.
1357 expr = SubInitList->getInit(0);
1358 }
1359 // Nested aggregate initialization and C++ initialization are handled later.
1360 } else if (isa<ImplicitValueInitExpr>(expr)) {
1361 // This happens during template instantiation when we see an InitListExpr
1362 // that we've already checked once.
1363 assert(SemaRef.Context.hasSameType(expr->getType(), ElemType) &&((void)0)
1364 "found implicit initialization for the wrong type")((void)0);
1365 UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
1366 ++Index;
1367 return;
1368 }
1369
1370 if (SemaRef.getLangOpts().CPlusPlus || isa<InitListExpr>(expr)) {
1371 // C++ [dcl.init.aggr]p2:
1372 // Each member is copy-initialized from the corresponding
1373 // initializer-clause.
1374
1375 // FIXME: Better EqualLoc?
1376 InitializationKind Kind =
1377 InitializationKind::CreateCopy(expr->getBeginLoc(), SourceLocation());
1378
1379 // Vector elements can be initialized from other vectors in which case
1380 // we need initialization entity with a type of a vector (and not a vector
1381 // element!) initializing multiple vector elements.
1382 auto TmpEntity =
1383 (ElemType->isExtVectorType() && !Entity.getType()->isExtVectorType())
1384 ? InitializedEntity::InitializeTemporary(ElemType)
1385 : Entity;
1386
1387 InitializationSequence Seq(SemaRef, TmpEntity, Kind, expr,
1388 /*TopLevelOfInitList*/ true);
1389
1390 // C++14 [dcl.init.aggr]p13:
1391 // If the assignment-expression can initialize a member, the member is
1392 // initialized. Otherwise [...] brace elision is assumed
1393 //
1394 // Brace elision is never performed if the element is not an
1395 // assignment-expression.
1396 if (Seq || isa<InitListExpr>(expr)) {
1397 if (!VerifyOnly) {
1398 ExprResult Result = Seq.Perform(SemaRef, TmpEntity, Kind, expr);
1399 if (Result.isInvalid())
1400 hadError = true;
1401
1402 UpdateStructuredListElement(StructuredList, StructuredIndex,
1403 Result.getAs<Expr>());
1404 } else if (!Seq) {
1405 hadError = true;
1406 } else if (StructuredList) {
1407 UpdateStructuredListElement(StructuredList, StructuredIndex,
1408 getDummyInit());
1409 }
1410 ++Index;
1411 return;
1412 }
1413
1414 // Fall through for subaggregate initialization
1415 } else if (ElemType->isScalarType() || ElemType->isAtomicType()) {
1416 // FIXME: Need to handle atomic aggregate types with implicit init lists.
1417 return CheckScalarType(Entity, IList, ElemType, Index,
1418 StructuredList, StructuredIndex);
1419 } else if (const ArrayType *arrayType =
1420 SemaRef.Context.getAsArrayType(ElemType)) {
1421 // arrayType can be incomplete if we're initializing a flexible
1422 // array member. There's nothing we can do with the completed
1423 // type here, though.
1424
1425 if (IsStringInit(expr, arrayType, SemaRef.Context) == SIF_None) {
1426 // FIXME: Should we do this checking in verify-only mode?
1427 if (!VerifyOnly)
1428 CheckStringInit(expr, ElemType, arrayType, SemaRef);
1429 if (StructuredList)
1430 UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
1431 ++Index;
1432 return;
1433 }
1434
1435 // Fall through for subaggregate initialization.
1436
1437 } else {
1438 assert((ElemType->isRecordType() || ElemType->isVectorType() ||((void)0)
1439 ElemType->isOpenCLSpecificType()) && "Unexpected type")((void)0);
1440
1441 // C99 6.7.8p13:
1442 //
1443 // The initializer for a structure or union object that has
1444 // automatic storage duration shall be either an initializer
1445 // list as described below, or a single expression that has
1446 // compatible structure or union type. In the latter case, the
1447 // initial value of the object, including unnamed members, is
1448 // that of the expression.
1449 ExprResult ExprRes = expr;
1450 if (SemaRef.CheckSingleAssignmentConstraints(
1451 ElemType, ExprRes, !VerifyOnly) != Sema::Incompatible) {
1452 if (ExprRes.isInvalid())
1453 hadError = true;
1454 else {
1455 ExprRes = SemaRef.DefaultFunctionArrayLvalueConversion(ExprRes.get());
1456 if (ExprRes.isInvalid())
1457 hadError = true;
1458 }
1459 UpdateStructuredListElement(StructuredList, StructuredIndex,
1460 ExprRes.getAs<Expr>());
1461 ++Index;
1462 return;
1463 }
1464 ExprRes.get();
1465 // Fall through for subaggregate initialization
1466 }
1467
1468 // C++ [dcl.init.aggr]p12:
1469 //
1470 // [...] Otherwise, if the member is itself a non-empty
1471 // subaggregate, brace elision is assumed and the initializer is
1472 // considered for the initialization of the first member of
1473 // the subaggregate.
1474 // OpenCL vector initializer is handled elsewhere.
1475 if ((!SemaRef.getLangOpts().OpenCL && ElemType->isVectorType()) ||
1476 ElemType->isAggregateType()) {
1477 CheckImplicitInitList(Entity, IList, ElemType, Index, StructuredList,
1478 StructuredIndex);
1479 ++StructuredIndex;
1480
1481 // In C++20, brace elision is not permitted for a designated initializer.
1482 if (DirectlyDesignated && SemaRef.getLangOpts().CPlusPlus && !hadError) {
1483 if (InOverloadResolution)
1484 hadError = true;
1485 if (!VerifyOnly) {
1486 SemaRef.Diag(expr->getBeginLoc(),
1487 diag::ext_designated_init_brace_elision)
1488 << expr->getSourceRange()
1489 << FixItHint::CreateInsertion(expr->getBeginLoc(), "{")
1490 << FixItHint::CreateInsertion(
1491 SemaRef.getLocForEndOfToken(expr->getEndLoc()), "}");
1492 }
1493 }
1494 } else {
1495 if (!VerifyOnly) {
1496 // We cannot initialize this element, so let PerformCopyInitialization
1497 // produce the appropriate diagnostic. We already checked that this
1498 // initialization will fail.
1499 ExprResult Copy =
1500 SemaRef.PerformCopyInitialization(Entity, SourceLocation(), expr,
1501 /*TopLevelOfInitList=*/true);
1502 (void)Copy;
1503 assert(Copy.isInvalid() &&((void)0)
1504 "expected non-aggregate initialization to fail")((void)0);
1505 }
1506 hadError = true;
1507 ++Index;
1508 ++StructuredIndex;
1509 }
1510}
1511
1512void InitListChecker::CheckComplexType(const InitializedEntity &Entity,
1513 InitListExpr *IList, QualType DeclType,
1514 unsigned &Index,
1515 InitListExpr *StructuredList,
1516 unsigned &StructuredIndex) {
1517 assert(Index == 0 && "Index in explicit init list must be zero")((void)0);
1518
1519 // As an extension, clang supports complex initializers, which initialize
1520 // a complex number component-wise. When an explicit initializer list for
1521 // a complex number contains two two initializers, this extension kicks in:
1522 // it exepcts the initializer list to contain two elements convertible to
1523 // the element type of the complex type. The first element initializes
1524 // the real part, and the second element intitializes the imaginary part.
1525
1526 if (IList->getNumInits() != 2)
1527 return CheckScalarType(Entity, IList, DeclType, Index, StructuredList,
1528 StructuredIndex);
1529
1530 // This is an extension in C. (The builtin _Complex type does not exist
1531 // in the C++ standard.)
1532 if (!SemaRef.getLangOpts().CPlusPlus && !VerifyOnly)
1533 SemaRef.Diag(IList->getBeginLoc(), diag::ext_complex_component_init)
1534 << IList->getSourceRange();
1535
1536 // Initialize the complex number.
1537 QualType elementType = DeclType->castAs<ComplexType>()->getElementType();
1538 InitializedEntity ElementEntity =
1539 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
1540
1541 for (unsigned i = 0; i < 2; ++i) {
1542 ElementEntity.setElementIndex(Index);
1543 CheckSubElementType(ElementEntity, IList, elementType, Index,
1544 StructuredList, StructuredIndex);
1545 }
1546}
1547
1548void InitListChecker::CheckScalarType(const InitializedEntity &Entity,
1549 InitListExpr *IList, QualType DeclType,
1550 unsigned &Index,
1551 InitListExpr *StructuredList,
1552 unsigned &StructuredIndex) {
1553 if (Index >= IList->getNumInits()) {
1554 if (!VerifyOnly) {
1555 if (DeclType->isSizelessBuiltinType())
1556 SemaRef.Diag(IList->getBeginLoc(),
1557 SemaRef.getLangOpts().CPlusPlus11
1558 ? diag::warn_cxx98_compat_empty_sizeless_initializer
1559 : diag::err_empty_sizeless_initializer)
1560 << DeclType << IList->getSourceRange();
1561 else
1562 SemaRef.Diag(IList->getBeginLoc(),
1563 SemaRef.getLangOpts().CPlusPlus11
1564 ? diag::warn_cxx98_compat_empty_scalar_initializer
1565 : diag::err_empty_scalar_initializer)
1566 << IList->getSourceRange();
1567 }
1568 hadError = !SemaRef.getLangOpts().CPlusPlus11;
1569 ++Index;
1570 ++StructuredIndex;
1571 return;
1572 }
1573
1574 Expr *expr = IList->getInit(Index);
1575 if (InitListExpr *SubIList = dyn_cast<InitListExpr>(expr)) {
1576 // FIXME: This is invalid, and accepting it causes overload resolution
1577 // to pick the wrong overload in some corner cases.
1578 if (!VerifyOnly)
1579 SemaRef.Diag(SubIList->getBeginLoc(), diag::ext_many_braces_around_init)
1580 << DeclType->isSizelessBuiltinType() << SubIList->getSourceRange();
1581
1582 CheckScalarType(Entity, SubIList, DeclType, Index, StructuredList,
1583 StructuredIndex);
1584 return;
1585 } else if (isa<DesignatedInitExpr>(expr)) {
1586 if (!VerifyOnly)
1587 SemaRef.Diag(expr->getBeginLoc(),
1588 diag::err_designator_for_scalar_or_sizeless_init)
1589 << DeclType->isSizelessBuiltinType() << DeclType
1590 << expr->getSourceRange();
1591 hadError = true;
1592 ++Index;
1593 ++StructuredIndex;
1594 return;
1595 }
1596
1597 ExprResult Result;
1598 if (VerifyOnly) {
1599 if (SemaRef.CanPerformCopyInitialization(Entity, expr))
1600 Result = getDummyInit();
1601 else
1602 Result = ExprError();
1603 } else {
1604 Result =
1605 SemaRef.PerformCopyInitialization(Entity, expr->getBeginLoc(), expr,
1606 /*TopLevelOfInitList=*/true);
1607 }
1608
1609 Expr *ResultExpr = nullptr;
1610
1611 if (Result.isInvalid())
1612 hadError = true; // types weren't compatible.
1613 else {
1614 ResultExpr = Result.getAs<Expr>();
1615
1616 if (ResultExpr != expr && !VerifyOnly) {
1617 // The type was promoted, update initializer list.
1618 // FIXME: Why are we updating the syntactic init list?
1619 IList->setInit(Index, ResultExpr);
1620 }
1621 }
1622 UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
1623 ++Index;
1624}
1625
1626void InitListChecker::CheckReferenceType(const InitializedEntity &Entity,
1627 InitListExpr *IList, QualType DeclType,
1628 unsigned &Index,
1629 InitListExpr *StructuredList,
1630 unsigned &StructuredIndex) {
1631 if (Index >= IList->getNumInits()) {
1632 // FIXME: It would be wonderful if we could point at the actual member. In
1633 // general, it would be useful to pass location information down the stack,
1634 // so that we know the location (or decl) of the "current object" being
1635 // initialized.
1636 if (!VerifyOnly)
1637 SemaRef.Diag(IList->getBeginLoc(),
1638 diag::err_init_reference_member_uninitialized)
1639 << DeclType << IList->getSourceRange();
1640 hadError = true;
1641 ++Index;
1642 ++StructuredIndex;
1643 return;
1644 }
1645
1646 Expr *expr = IList->getInit(Index);
1647 if (isa<InitListExpr>(expr) && !SemaRef.getLangOpts().CPlusPlus11) {
1648 if (!VerifyOnly)
1649 SemaRef.Diag(IList->getBeginLoc(), diag::err_init_non_aggr_init_list)
1650 << DeclType << IList->getSourceRange();
1651 hadError = true;
1652 ++Index;
1653 ++StructuredIndex;
1654 return;
1655 }
1656
1657 ExprResult Result;
1658 if (VerifyOnly) {
1659 if (SemaRef.CanPerformCopyInitialization(Entity,expr))
1660 Result = getDummyInit();
1661 else
1662 Result = ExprError();
1663 } else {
1664 Result =
1665 SemaRef.PerformCopyInitialization(Entity, expr->getBeginLoc(), expr,
1666 /*TopLevelOfInitList=*/true);
1667 }
1668
1669 if (Result.isInvalid())
1670 hadError = true;
1671
1672 expr = Result.getAs<Expr>();
1673 // FIXME: Why are we updating the syntactic init list?
1674 if (!VerifyOnly && expr)
1675 IList->setInit(Index, expr);
1676
1677 UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
1678 ++Index;
1679}
1680
1681void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
1682 InitListExpr *IList, QualType DeclType,
1683 unsigned &Index,
1684 InitListExpr *StructuredList,
1685 unsigned &StructuredIndex) {
1686 const VectorType *VT = DeclType->castAs<VectorType>();
1687 unsigned maxElements = VT->getNumElements();
1688 unsigned numEltsInit = 0;
1689 QualType elementType = VT->getElementType();
1690
1691 if (Index >= IList->getNumInits()) {
1692 // Make sure the element type can be value-initialized.
1693 CheckEmptyInitializable(
1694 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity),
1695 IList->getEndLoc());
1696 return;
1697 }
1698
1699 if (!SemaRef.getLangOpts().OpenCL) {
1700 // If the initializing element is a vector, try to copy-initialize
1701 // instead of breaking it apart (which is doomed to failure anyway).
1702 Expr *Init = IList->getInit(Index);
1703 if (!isa<InitListExpr>(Init) && Init->getType()->isVectorType()) {
1704 ExprResult Result;
1705 if (VerifyOnly) {
1706 if (SemaRef.CanPerformCopyInitialization(Entity, Init))
1707 Result = getDummyInit();
1708 else
1709 Result = ExprError();
1710 } else {
1711 Result =
1712 SemaRef.PerformCopyInitialization(Entity, Init->getBeginLoc(), Init,
1713 /*TopLevelOfInitList=*/true);
1714 }
1715
1716 Expr *ResultExpr = nullptr;
1717 if (Result.isInvalid())
1718 hadError = true; // types weren't compatible.
1719 else {
1720 ResultExpr = Result.getAs<Expr>();
1721
1722 if (ResultExpr != Init && !VerifyOnly) {
1723 // The type was promoted, update initializer list.
1724 // FIXME: Why are we updating the syntactic init list?
1725 IList->setInit(Index, ResultExpr);
1726 }
1727 }
1728 UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
1729 ++Index;
1730 return;
1731 }
1732
1733 InitializedEntity ElementEntity =
1734 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
1735
1736 for (unsigned i = 0; i < maxElements; ++i, ++numEltsInit) {
1737 // Don't attempt to go past the end of the init list
1738 if (Index >= IList->getNumInits()) {
1739 CheckEmptyInitializable(ElementEntity, IList->getEndLoc());
1740 break;
1741 }
1742
1743 ElementEntity.setElementIndex(Index);
1744 CheckSubElementType(ElementEntity, IList, elementType, Index,
1745 StructuredList, StructuredIndex);
1746 }
1747
1748 if (VerifyOnly)
1749 return;
1750
1751 bool isBigEndian = SemaRef.Context.getTargetInfo().isBigEndian();
1752 const VectorType *T = Entity.getType()->castAs<VectorType>();
1753 if (isBigEndian && (T->getVectorKind() == VectorType::NeonVector ||
1754 T->getVectorKind() == VectorType::NeonPolyVector)) {
1755 // The ability to use vector initializer lists is a GNU vector extension
1756 // and is unrelated to the NEON intrinsics in arm_neon.h. On little
1757 // endian machines it works fine, however on big endian machines it
1758 // exhibits surprising behaviour:
1759 //
1760 // uint32x2_t x = {42, 64};
1761 // return vget_lane_u32(x, 0); // Will return 64.
1762 //
1763 // Because of this, explicitly call out that it is non-portable.
1764 //
1765 SemaRef.Diag(IList->getBeginLoc(),
1766 diag::warn_neon_vector_initializer_non_portable);
1767
1768 const char *typeCode;
1769 unsigned typeSize = SemaRef.Context.getTypeSize(elementType);
1770
1771 if (elementType->isFloatingType())
1772 typeCode = "f";
1773 else if (elementType->isSignedIntegerType())
1774 typeCode = "s";
1775 else if (elementType->isUnsignedIntegerType())
1776 typeCode = "u";
1777 else
1778 llvm_unreachable("Invalid element type!")__builtin_unreachable();
1779
1780 SemaRef.Diag(IList->getBeginLoc(),
1781 SemaRef.Context.getTypeSize(VT) > 64
1782 ? diag::note_neon_vector_initializer_non_portable_q
1783 : diag::note_neon_vector_initializer_non_portable)
1784 << typeCode << typeSize;
1785 }
1786
1787 return;
1788 }
1789
1790 InitializedEntity ElementEntity =
1791 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
1792
1793 // OpenCL initializers allows vectors to be constructed from vectors.
1794 for (unsigned i = 0; i < maxElements; ++i) {
1795 // Don't attempt to go past the end of the init list
1796 if (Index >= IList->getNumInits())
1797 break;
1798
1799 ElementEntity.setElementIndex(Index);
1800
1801 QualType IType = IList->getInit(Index)->getType();
1802 if (!IType->isVectorType()) {
1803 CheckSubElementType(ElementEntity, IList, elementType, Index,
1804 StructuredList, StructuredIndex);
1805 ++numEltsInit;
1806 } else {
1807 QualType VecType;
1808 const VectorType *IVT = IType->castAs<VectorType>();
1809 unsigned numIElts = IVT->getNumElements();
1810
1811 if (IType->isExtVectorType())
1812 VecType = SemaRef.Context.getExtVectorType(elementType, numIElts);
1813 else
1814 VecType = SemaRef.Context.getVectorType(elementType, numIElts,
1815 IVT->getVectorKind());
1816 CheckSubElementType(ElementEntity, IList, VecType, Index,
1817 StructuredList, StructuredIndex);
1818 numEltsInit += numIElts;
1819 }
1820 }
1821
1822 // OpenCL requires all elements to be initialized.
1823 if (numEltsInit != maxElements) {
1824 if (!VerifyOnly)
1825 SemaRef.Diag(IList->getBeginLoc(),
1826 diag::err_vector_incorrect_num_initializers)
1827 << (numEltsInit < maxElements) << maxElements << numEltsInit;
1828 hadError = true;
1829 }
1830}
1831
1832/// Check if the type of a class element has an accessible destructor, and marks
1833/// it referenced. Returns true if we shouldn't form a reference to the
1834/// destructor.
1835///
1836/// Aggregate initialization requires a class element's destructor be
1837/// accessible per 11.6.1 [dcl.init.aggr]:
1838///
1839/// The destructor for each element of class type is potentially invoked
1840/// (15.4 [class.dtor]) from the context where the aggregate initialization
1841/// occurs.
1842static bool checkDestructorReference(QualType ElementType, SourceLocation Loc,
1843 Sema &SemaRef) {
1844 auto *CXXRD = ElementType->getAsCXXRecordDecl();
1845 if (!CXXRD)
1846 return false;
1847
1848 CXXDestructorDecl *Destructor = SemaRef.LookupDestructor(CXXRD);
1849 SemaRef.CheckDestructorAccess(Loc, Destructor,
1850 SemaRef.PDiag(diag::err_access_dtor_temp)
1851 << ElementType);
1852 SemaRef.MarkFunctionReferenced(Loc, Destructor);
1853 return SemaRef.DiagnoseUseOfDecl(Destructor, Loc);
1854}
1855
1856void InitListChecker::CheckArrayType(const InitializedEntity &Entity,
1857 InitListExpr *IList, QualType &DeclType,
1858 llvm::APSInt elementIndex,
1859 bool SubobjectIsDesignatorContext,
1860 unsigned &Index,
1861 InitListExpr *StructuredList,
1862 unsigned &StructuredIndex) {
1863 const ArrayType *arrayType = SemaRef.Context.getAsArrayType(DeclType);
1864
1865 if (!VerifyOnly) {
1866 if (checkDestructorReference(arrayType->getElementType(),
1867 IList->getEndLoc(), SemaRef)) {
1868 hadError = true;
1869 return;
1870 }
1871 }
1872
1873 // Check for the special-case of initializing an array with a string.
1874 if (Index < IList->getNumInits()) {
1875 if (IsStringInit(IList->getInit(Index), arrayType, SemaRef.Context) ==
1876 SIF_None) {
1877 // We place the string literal directly into the resulting
1878 // initializer list. This is the only place where the structure
1879 // of the structured initializer list doesn't match exactly,
1880 // because doing so would involve allocating one character
1881 // constant for each string.
1882 // FIXME: Should we do these checks in verify-only mode too?
1883 if (!VerifyOnly)
1884 CheckStringInit(IList->getInit(Index), DeclType, arrayType, SemaRef);
1885 if (StructuredList) {
1886 UpdateStructuredListElement(StructuredList, StructuredIndex,
1887 IList->getInit(Index));
1888 StructuredList->resizeInits(SemaRef.Context, StructuredIndex);
1889 }
1890 ++Index;
1891 return;
1892 }
1893 }
1894 if (const VariableArrayType *VAT = dyn_cast<VariableArrayType>(arrayType)) {
1895 // Check for VLAs; in standard C it would be possible to check this
1896 // earlier, but I don't know where clang accepts VLAs (gcc accepts
1897 // them in all sorts of strange places).
1898 if (!VerifyOnly)
1899 SemaRef.Diag(VAT->getSizeExpr()->getBeginLoc(),
1900 diag::err_variable_object_no_init)
1901 << VAT->getSizeExpr()->getSourceRange();
1902 hadError = true;
1903 ++Index;
1904 ++StructuredIndex;
1905 return;
1906 }
1907
1908 // We might know the maximum number of elements in advance.
1909 llvm::APSInt maxElements(elementIndex.getBitWidth(),
1910 elementIndex.isUnsigned());
1911 bool maxElementsKnown = false;
1912 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(arrayType)) {
1913 maxElements = CAT->getSize();
1914 elementIndex = elementIndex.extOrTrunc(maxElements.getBitWidth());
1915 elementIndex.setIsUnsigned(maxElements.isUnsigned());
1916 maxElementsKnown = true;
1917 }
1918
1919 QualType elementType = arrayType->getElementType();
1920 while (Index < IList->getNumInits()) {
1921 Expr *Init = IList->getInit(Index);
1922 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
1923 // If we're not the subobject that matches up with the '{' for
1924 // the designator, we shouldn't be handling the
1925 // designator. Return immediately.
1926 if (!SubobjectIsDesignatorContext)
1927 return;
1928
1929 // Handle this designated initializer. elementIndex will be
1930 // updated to be the next array element we'll initialize.
1931 if (CheckDesignatedInitializer(Entity, IList, DIE, 0,
1932 DeclType, nullptr, &elementIndex, Index,
1933 StructuredList, StructuredIndex, true,
1934 false)) {
1935 hadError = true;
1936 continue;
1937 }
1938
1939 if (elementIndex.getBitWidth() > maxElements.getBitWidth())
1940 maxElements = maxElements.extend(elementIndex.getBitWidth());
1941 else if (elementIndex.getBitWidth() < maxElements.getBitWidth())
1942 elementIndex = elementIndex.extend(maxElements.getBitWidth());
1943 elementIndex.setIsUnsigned(maxElements.isUnsigned());
1944
1945 // If the array is of incomplete type, keep track of the number of
1946 // elements in the initializer.
1947 if (!maxElementsKnown && elementIndex > maxElements)
1948 maxElements = elementIndex;
1949
1950 continue;
1951 }
1952
1953 // If we know the maximum number of elements, and we've already
1954 // hit it, stop consuming elements in the initializer list.
1955 if (maxElementsKnown && elementIndex == maxElements)
1956 break;
1957
1958 InitializedEntity ElementEntity =
1959 InitializedEntity::InitializeElement(SemaRef.Context, StructuredIndex,
1960 Entity);
1961 // Check this element.
1962 CheckSubElementType(ElementEntity, IList, elementType, Index,
1963 StructuredList, StructuredIndex);
1964 ++elementIndex;
1965
1966 // If the array is of incomplete type, keep track of the number of
1967 // elements in the initializer.
1968 if (!maxElementsKnown && elementIndex > maxElements)
1969 maxElements = elementIndex;
1970 }
1971 if (!hadError && DeclType->isIncompleteArrayType() && !VerifyOnly) {
1972 // If this is an incomplete array type, the actual type needs to
1973 // be calculated here.
1974 llvm::APSInt Zero(maxElements.getBitWidth(), maxElements.isUnsigned());
1975 if (maxElements == Zero && !Entity.isVariableLengthArrayNew()) {
1976 // Sizing an array implicitly to zero is not allowed by ISO C,
1977 // but is supported by GNU.
1978 SemaRef.Diag(IList->getBeginLoc(), diag::ext_typecheck_zero_array_size);
1979 }
1980
1981 DeclType = SemaRef.Context.getConstantArrayType(
1982 elementType, maxElements, nullptr, ArrayType::Normal, 0);
1983 }
1984 if (!hadError) {
1985 // If there are any members of the array that get value-initialized, check
1986 // that is possible. That happens if we know the bound and don't have
1987 // enough elements, or if we're performing an array new with an unknown
1988 // bound.
1989 if ((maxElementsKnown && elementIndex < maxElements) ||
1990 Entity.isVariableLengthArrayNew())
1991 CheckEmptyInitializable(
1992 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity),
1993 IList->getEndLoc());
1994 }
1995}
1996
1997bool InitListChecker::CheckFlexibleArrayInit(const InitializedEntity &Entity,
1998 Expr *InitExpr,
1999 FieldDecl *Field,
2000 bool TopLevelObject) {
2001 // Handle GNU flexible array initializers.
2002 unsigned FlexArrayDiag;
2003 if (isa<InitListExpr>(InitExpr) &&
2004 cast<InitListExpr>(InitExpr)->getNumInits() == 0) {
2005 // Empty flexible array init always allowed as an extension
2006 FlexArrayDiag = diag::ext_flexible_array_init;
2007 } else if (SemaRef.getLangOpts().CPlusPlus) {
2008 // Disallow flexible array init in C++; it is not required for gcc
2009 // compatibility, and it needs work to IRGen correctly in general.
2010 FlexArrayDiag = diag::err_flexible_array_init;
2011 } else if (!TopLevelObject) {
2012 // Disallow flexible array init on non-top-level object
2013 FlexArrayDiag = diag::err_flexible_array_init;
2014 } else if (Entity.getKind() != InitializedEntity::EK_Variable) {
2015 // Disallow flexible array init on anything which is not a variable.
2016 FlexArrayDiag = diag::err_flexible_array_init;
2017 } else if (cast<VarDecl>(Entity.getDecl())->hasLocalStorage()) {
2018 // Disallow flexible array init on local variables.
2019 FlexArrayDiag = diag::err_flexible_array_init;
2020 } else {
2021 // Allow other cases.
2022 FlexArrayDiag = diag::ext_flexible_array_init;
2023 }
2024
2025 if (!VerifyOnly) {
2026 SemaRef.Diag(InitExpr->getBeginLoc(), FlexArrayDiag)
2027 << InitExpr->getBeginLoc();
2028 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
2029 << Field;
2030 }
2031
2032 return FlexArrayDiag != diag::ext_flexible_array_init;
2033}
2034
2035void InitListChecker::CheckStructUnionTypes(
2036 const InitializedEntity &Entity, InitListExpr *IList, QualType DeclType,
2037 CXXRecordDecl::base_class_range Bases, RecordDecl::field_iterator Field,
2038 bool SubobjectIsDesignatorContext, unsigned &Index,
2039 InitListExpr *StructuredList, unsigned &StructuredIndex,
2040 bool TopLevelObject) {
2041 RecordDecl *structDecl = DeclType->castAs<RecordType>()->getDecl();
2042
2043 // If the record is invalid, some of it's members are invalid. To avoid
2044 // confusion, we forgo checking the intializer for the entire record.
2045 if (structDecl->isInvalidDecl()) {
2046 // Assume it was supposed to consume a single initializer.
2047 ++Index;
2048 hadError = true;
2049 return;
2050 }
2051
2052 if (DeclType->isUnionType() && IList->getNumInits() == 0) {
2053 RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
2054
2055 if (!VerifyOnly)
2056 for (FieldDecl *FD : RD->fields()) {
2057 QualType ET = SemaRef.Context.getBaseElementType(FD->getType());
2058 if (checkDestructorReference(ET, IList->getEndLoc(), SemaRef)) {
2059 hadError = true;
2060 return;
2061 }
2062 }
2063
2064 // If there's a default initializer, use it.
2065 if (isa<CXXRecordDecl>(RD) &&
2066 cast<CXXRecordDecl>(RD)->hasInClassInitializer()) {
2067 if (!StructuredList)
2068 return;
2069 for (RecordDecl::field_iterator FieldEnd = RD->field_end();
2070 Field != FieldEnd; ++Field) {
2071 if (Field->hasInClassInitializer()) {
2072 StructuredList->setInitializedFieldInUnion(*Field);
2073 // FIXME: Actually build a CXXDefaultInitExpr?
2074 return;
2075 }
2076 }
2077 }
2078
2079 // Value-initialize the first member of the union that isn't an unnamed
2080 // bitfield.
2081 for (RecordDecl::field_iterator FieldEnd = RD->field_end();
2082 Field != FieldEnd; ++Field) {
2083 if (!Field->isUnnamedBitfield()) {
2084 CheckEmptyInitializable(
2085 InitializedEntity::InitializeMember(*Field, &Entity),
2086 IList->getEndLoc());
2087 if (StructuredList)
2088 StructuredList->setInitializedFieldInUnion(*Field);
2089 break;
2090 }
2091 }
2092 return;
2093 }
2094
2095 bool InitializedSomething = false;
2096
2097 // If we have any base classes, they are initialized prior to the fields.
2098 for (auto &Base : Bases) {
2099 Expr *Init = Index < IList->getNumInits() ? IList->getInit(Index) : nullptr;
2100
2101 // Designated inits always initialize fields, so if we see one, all
2102 // remaining base classes have no explicit initializer.
2103 if (Init && isa<DesignatedInitExpr>(Init))
2104 Init = nullptr;
2105
2106 SourceLocation InitLoc = Init ? Init->getBeginLoc() : IList->getEndLoc();
2107 InitializedEntity BaseEntity = InitializedEntity::InitializeBase(
2108 SemaRef.Context, &Base, false, &Entity);
2109 if (Init) {
2110 CheckSubElementType(BaseEntity, IList, Base.getType(), Index,
2111 StructuredList, StructuredIndex);
2112 InitializedSomething = true;
2113 } else {
2114 CheckEmptyInitializable(BaseEntity, InitLoc);
2115 }
2116
2117 if (!VerifyOnly)
2118 if (checkDestructorReference(Base.getType(), InitLoc, SemaRef)) {
2119 hadError = true;
2120 return;
2121 }
2122 }
2123
2124 // If structDecl is a forward declaration, this loop won't do
2125 // anything except look at designated initializers; That's okay,
2126 // because an error should get printed out elsewhere. It might be
2127 // worthwhile to skip over the rest of the initializer, though.
2128 RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
2129 RecordDecl::field_iterator FieldEnd = RD->field_end();
2130 bool CheckForMissingFields =
2131 !IList->isIdiomaticZeroInitializer(SemaRef.getLangOpts());
2132 bool HasDesignatedInit = false;
2133
2134 while (Index < IList->getNumInits()) {
2135 Expr *Init = IList->getInit(Index);
2136 SourceLocation InitLoc = Init->getBeginLoc();
2137
2138 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
2139 // If we're not the subobject that matches up with the '{' for
2140 // the designator, we shouldn't be handling the
2141 // designator. Return immediately.
2142 if (!SubobjectIsDesignatorContext)
2143 return;
2144
2145 HasDesignatedInit = true;
2146
2147 // Handle this designated initializer. Field will be updated to
2148 // the next field that we'll be initializing.
2149 if (CheckDesignatedInitializer(Entity, IList, DIE, 0,
2150 DeclType, &Field, nullptr, Index,
2151 StructuredList, StructuredIndex,
2152 true, TopLevelObject))
2153 hadError = true;
2154 else if (!VerifyOnly) {
2155 // Find the field named by the designated initializer.
2156 RecordDecl::field_iterator F = RD->field_begin();
2157 while (std::next(F) != Field)
2158 ++F;
2159 QualType ET = SemaRef.Context.getBaseElementType(F->getType());
2160 if (checkDestructorReference(ET, InitLoc, SemaRef)) {
2161 hadError = true;
2162 return;
2163 }
2164 }
2165
2166 InitializedSomething = true;
2167
2168 // Disable check for missing fields when designators are used.
2169 // This matches gcc behaviour.
2170 CheckForMissingFields = false;
2171 continue;
2172 }
2173
2174 if (Field == FieldEnd) {
2175 // We've run out of fields. We're done.
2176 break;
2177 }
2178
2179 // We've already initialized a member of a union. We're done.
2180 if (InitializedSomething && DeclType->isUnionType())
2181 break;
2182
2183 // If we've hit the flexible array member at the end, we're done.
2184 if (Field->getType()->isIncompleteArrayType())
2185 break;
2186
2187 if (Field->isUnnamedBitfield()) {
2188 // Don't initialize unnamed bitfields, e.g. "int : 20;"
2189 ++Field;
2190 continue;
2191 }
2192
2193 // Make sure we can use this declaration.
2194 bool InvalidUse;
2195 if (VerifyOnly)
2196 InvalidUse = !SemaRef.CanUseDecl(*Field, TreatUnavailableAsInvalid);
2197 else
2198 InvalidUse = SemaRef.DiagnoseUseOfDecl(
2199 *Field, IList->getInit(Index)->getBeginLoc());
2200 if (InvalidUse) {
2201 ++Index;
2202 ++Field;
2203 hadError = true;
2204 continue;
2205 }
2206
2207 if (!VerifyOnly) {
2208 QualType ET = SemaRef.Context.getBaseElementType(Field->getType());
2209 if (checkDestructorReference(ET, InitLoc, SemaRef)) {
2210 hadError = true;
2211 return;
2212 }
2213 }
2214
2215 InitializedEntity MemberEntity =
2216 InitializedEntity::InitializeMember(*Field, &Entity);
2217 CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
2218 StructuredList, StructuredIndex);
2219 InitializedSomething = true;
2220
2221 if (DeclType->isUnionType() && StructuredList) {
2222 // Initialize the first field within the union.
2223 StructuredList->setInitializedFieldInUnion(*Field);
2224 }
2225
2226 ++Field;
2227 }
2228
2229 // Emit warnings for missing struct field initializers.
2230 if (!VerifyOnly && InitializedSomething && CheckForMissingFields &&
2231 Field != FieldEnd && !Field->getType()->isIncompleteArrayType() &&
2232 !DeclType->isUnionType()) {
2233 // It is possible we have one or more unnamed bitfields remaining.
2234 // Find first (if any) named field and emit warning.
2235 for (RecordDecl::field_iterator it = Field, end = RD->field_end();
2236 it != end; ++it) {
2237 if (!it->isUnnamedBitfield() && !it->hasInClassInitializer()) {
2238 SemaRef.Diag(IList->getSourceRange().getEnd(),
2239 diag::warn_missing_field_initializers) << *it;
2240 break;
2241 }
2242 }
2243 }
2244
2245 // Check that any remaining fields can be value-initialized if we're not
2246 // building a structured list. (If we are, we'll check this later.)
2247 if (!StructuredList && Field != FieldEnd && !DeclType->isUnionType() &&
2248 !Field->getType()->isIncompleteArrayType()) {
2249 for (; Field != FieldEnd && !hadError; ++Field) {
2250 if (!Field->isUnnamedBitfield() && !Field->hasInClassInitializer())
2251 CheckEmptyInitializable(
2252 InitializedEntity::InitializeMember(*Field, &Entity),
2253 IList->getEndLoc());
2254 }
2255 }
2256
2257 // Check that the types of the remaining fields have accessible destructors.
2258 if (!VerifyOnly) {
2259 // If the initializer expression has a designated initializer, check the
2260 // elements for which a designated initializer is not provided too.
2261 RecordDecl::field_iterator I = HasDesignatedInit ? RD->field_begin()
2262 : Field;
2263 for (RecordDecl::field_iterator E = RD->field_end(); I != E; ++I) {
2264 QualType ET = SemaRef.Context.getBaseElementType(I->getType());
2265 if (checkDestructorReference(ET, IList->getEndLoc(), SemaRef)) {
2266 hadError = true;
2267 return;
2268 }
2269 }
2270 }
2271
2272 if (Field == FieldEnd || !Field->getType()->isIncompleteArrayType() ||
2273 Index >= IList->getNumInits())
2274 return;
2275
2276 if (CheckFlexibleArrayInit(Entity, IList->getInit(Index), *Field,
2277 TopLevelObject)) {
2278 hadError = true;
2279 ++Index;
2280 return;
2281 }
2282
2283 InitializedEntity MemberEntity =
2284 InitializedEntity::InitializeMember(*Field, &Entity);
2285
2286 if (isa<InitListExpr>(IList->getInit(Index)))
2287 CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
2288 StructuredList, StructuredIndex);
2289 else
2290 CheckImplicitInitList(MemberEntity, IList, Field->getType(), Index,
2291 StructuredList, StructuredIndex);
2292}
2293
2294/// Expand a field designator that refers to a member of an
2295/// anonymous struct or union into a series of field designators that
2296/// refers to the field within the appropriate subobject.
2297///
2298static void ExpandAnonymousFieldDesignator(Sema &SemaRef,
2299 DesignatedInitExpr *DIE,
2300 unsigned DesigIdx,
2301 IndirectFieldDecl *IndirectField) {
2302 typedef DesignatedInitExpr::Designator Designator;
2303
2304 // Build the replacement designators.
2305 SmallVector<Designator, 4> Replacements;
2306 for (IndirectFieldDecl::chain_iterator PI = IndirectField->chain_begin(),
2307 PE = IndirectField->chain_end(); PI != PE; ++PI) {
2308 if (PI + 1 == PE)
2309 Replacements.push_back(Designator((IdentifierInfo *)nullptr,
2310 DIE->getDesignator(DesigIdx)->getDotLoc(),
2311 DIE->getDesignator(DesigIdx)->getFieldLoc()));
2312 else
2313 Replacements.push_back(Designator((IdentifierInfo *)nullptr,
2314 SourceLocation(), SourceLocation()));
2315 assert(isa<FieldDecl>(*PI))((void)0);
2316 Replacements.back().setField(cast<FieldDecl>(*PI));
2317 }
2318
2319 // Expand the current designator into the set of replacement
2320 // designators, so we have a full subobject path down to where the
2321 // member of the anonymous struct/union is actually stored.
2322 DIE->ExpandDesignator(SemaRef.Context, DesigIdx, &Replacements[0],
2323 &Replacements[0] + Replacements.size());
2324}
2325
2326static DesignatedInitExpr *CloneDesignatedInitExpr(Sema &SemaRef,
2327 DesignatedInitExpr *DIE) {
2328 unsigned NumIndexExprs = DIE->getNumSubExprs() - 1;
2329 SmallVector<Expr*, 4> IndexExprs(NumIndexExprs);
2330 for (unsigned I = 0; I < NumIndexExprs; ++I)
2331 IndexExprs[I] = DIE->getSubExpr(I + 1);
2332 return DesignatedInitExpr::Create(SemaRef.Context, DIE->designators(),
2333 IndexExprs,
2334 DIE->getEqualOrColonLoc(),
2335 DIE->usesGNUSyntax(), DIE->getInit());
2336}
2337
2338namespace {
2339
2340// Callback to only accept typo corrections that are for field members of
2341// the given struct or union.
2342class FieldInitializerValidatorCCC final : public CorrectionCandidateCallback {
2343 public:
2344 explicit FieldInitializerValidatorCCC(RecordDecl *RD)
2345 : Record(RD) {}
2346
2347 bool ValidateCandidate(const TypoCorrection &candidate) override {
2348 FieldDecl *FD = candidate.getCorrectionDeclAs<FieldDecl>();
2349 return FD && FD->getDeclContext()->getRedeclContext()->Equals(Record);
2350 }
2351
2352 std::unique_ptr<CorrectionCandidateCallback> clone() override {
2353 return std::make_unique<FieldInitializerValidatorCCC>(*this);
2354 }
2355
2356 private:
2357 RecordDecl *Record;
2358};
2359
2360} // end anonymous namespace
2361
2362/// Check the well-formedness of a C99 designated initializer.
2363///
2364/// Determines whether the designated initializer @p DIE, which
2365/// resides at the given @p Index within the initializer list @p
2366/// IList, is well-formed for a current object of type @p DeclType
2367/// (C99 6.7.8). The actual subobject that this designator refers to
2368/// within the current subobject is returned in either
2369/// @p NextField or @p NextElementIndex (whichever is appropriate).
2370///
2371/// @param IList The initializer list in which this designated
2372/// initializer occurs.
2373///
2374/// @param DIE The designated initializer expression.
2375///
2376/// @param DesigIdx The index of the current designator.
2377///
2378/// @param CurrentObjectType The type of the "current object" (C99 6.7.8p17),
2379/// into which the designation in @p DIE should refer.
2380///
2381/// @param NextField If non-NULL and the first designator in @p DIE is
2382/// a field, this will be set to the field declaration corresponding
2383/// to the field named by the designator. On input, this is expected to be
2384/// the next field that would be initialized in the absence of designation,
2385/// if the complete object being initialized is a struct.
2386///
2387/// @param NextElementIndex If non-NULL and the first designator in @p
2388/// DIE is an array designator or GNU array-range designator, this
2389/// will be set to the last index initialized by this designator.
2390///
2391/// @param Index Index into @p IList where the designated initializer
2392/// @p DIE occurs.
2393///
2394/// @param StructuredList The initializer list expression that
2395/// describes all of the subobject initializers in the order they'll
2396/// actually be initialized.
2397///
2398/// @returns true if there was an error, false otherwise.
2399bool
2400InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
2401 InitListExpr *IList,
2402 DesignatedInitExpr *DIE,
2403 unsigned DesigIdx,
2404 QualType &CurrentObjectType,
2405 RecordDecl::field_iterator *NextField,
2406 llvm::APSInt *NextElementIndex,
2407 unsigned &Index,
2408 InitListExpr *StructuredList,
2409 unsigned &StructuredIndex,
2410 bool FinishSubobjectInit,
2411 bool TopLevelObject) {
2412 if (DesigIdx == DIE->size()) {
2413 // C++20 designated initialization can result in direct-list-initialization
2414 // of the designated subobject. This is the only way that we can end up
2415 // performing direct initialization as part of aggregate initialization, so
2416 // it needs special handling.
2417 if (DIE->isDirectInit()) {
2418 Expr *Init = DIE->getInit();
2419 assert(isa<InitListExpr>(Init) &&((void)0)
2420 "designator result in direct non-list initialization?")((void)0);
2421 InitializationKind Kind = InitializationKind::CreateDirectList(
2422 DIE->getBeginLoc(), Init->getBeginLoc(), Init->getEndLoc());
2423 InitializationSequence Seq(SemaRef, Entity, Kind, Init,
2424 /*TopLevelOfInitList*/ true);
2425 if (StructuredList) {
2426 ExprResult Result = VerifyOnly
2427 ? getDummyInit()
2428 : Seq.Perform(SemaRef, Entity, Kind, Init);
2429 UpdateStructuredListElement(StructuredList, StructuredIndex,
2430 Result.get());
2431 }
2432 ++Index;
2433 return !Seq;
2434 }
2435
2436 // Check the actual initialization for the designated object type.
2437 bool prevHadError = hadError;
2438
2439 // Temporarily remove the designator expression from the
2440 // initializer list that the child calls see, so that we don't try
2441 // to re-process the designator.
2442 unsigned OldIndex = Index;
2443 IList->setInit(OldIndex, DIE->getInit());
2444
2445 CheckSubElementType(Entity, IList, CurrentObjectType, Index, StructuredList,
2446 StructuredIndex, /*DirectlyDesignated=*/true);
2447
2448 // Restore the designated initializer expression in the syntactic
2449 // form of the initializer list.
2450 if (IList->getInit(OldIndex) != DIE->getInit())
2451 DIE->setInit(IList->getInit(OldIndex));
2452 IList->setInit(OldIndex, DIE);
2453
2454 return hadError && !prevHadError;
2455 }
2456
2457 DesignatedInitExpr::Designator *D = DIE->getDesignator(DesigIdx);
2458 bool IsFirstDesignator = (DesigIdx == 0);
2459 if (IsFirstDesignator ? FullyStructuredList : StructuredList) {
2460 // Determine the structural initializer list that corresponds to the
2461 // current subobject.
2462 if (IsFirstDesignator)
2463 StructuredList = FullyStructuredList;
2464 else {
2465 Expr *ExistingInit = StructuredIndex < StructuredList->getNumInits() ?
2466 StructuredList->getInit(StructuredIndex) : nullptr;
2467 if (!ExistingInit && StructuredList->hasArrayFiller())
2468 ExistingInit = StructuredList->getArrayFiller();
2469
2470 if (!ExistingInit)
2471 StructuredList = getStructuredSubobjectInit(
2472 IList, Index, CurrentObjectType, StructuredList, StructuredIndex,
2473 SourceRange(D->getBeginLoc(), DIE->getEndLoc()));
2474 else if (InitListExpr *Result = dyn_cast<InitListExpr>(ExistingInit))
2475 StructuredList = Result;
2476 else {
2477 // We are creating an initializer list that initializes the
2478 // subobjects of the current object, but there was already an
2479 // initialization that completely initialized the current
2480 // subobject, e.g., by a compound literal:
2481 //
2482 // struct X { int a, b; };
2483 // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 };
2484 //
2485 // Here, xs[0].a == 1 and xs[0].b == 3, since the second,
2486 // designated initializer re-initializes only its current object
2487 // subobject [0].b.
2488 diagnoseInitOverride(ExistingInit,
2489 SourceRange(D->getBeginLoc(), DIE->getEndLoc()),
2490 /*FullyOverwritten=*/false);
2491
2492 if (!VerifyOnly) {
2493 if (DesignatedInitUpdateExpr *E =
2494 dyn_cast<DesignatedInitUpdateExpr>(ExistingInit))
2495 StructuredList = E->getUpdater();
2496 else {
2497 DesignatedInitUpdateExpr *DIUE = new (SemaRef.Context)
2498 DesignatedInitUpdateExpr(SemaRef.Context, D->getBeginLoc(),
2499 ExistingInit, DIE->getEndLoc());
2500 StructuredList->updateInit(SemaRef.Context, StructuredIndex, DIUE);
2501 StructuredList = DIUE->getUpdater();
2502 }
2503 } else {
2504 // We don't need to track the structured representation of a
2505 // designated init update of an already-fully-initialized object in
2506 // verify-only mode. The only reason we would need the structure is
2507 // to determine where the uninitialized "holes" are, and in this
2508 // case, we know there aren't any and we can't introduce any.
2509 StructuredList = nullptr;
2510 }
2511 }
2512 }
2513 }
2514
2515 if (D->isFieldDesignator()) {
2516 // C99 6.7.8p7:
2517 //
2518 // If a designator has the form
2519 //
2520 // . identifier
2521 //
2522 // then the current object (defined below) shall have
2523 // structure or union type and the identifier shall be the
2524 // name of a member of that type.
2525 const RecordType *RT = CurrentObjectType->getAs<RecordType>();
2526 if (!RT) {
2527 SourceLocation Loc = D->getDotLoc();
2528 if (Loc.isInvalid())
2529 Loc = D->getFieldLoc();
2530 if (!VerifyOnly)
2531 SemaRef.Diag(Loc, diag::err_field_designator_non_aggr)
2532 << SemaRef.getLangOpts().CPlusPlus << CurrentObjectType;
2533 ++Index;
2534 return true;
2535 }
2536
2537 FieldDecl *KnownField = D->getField();
2538 if (!KnownField) {
2539 IdentifierInfo *FieldName = D->getFieldName();
2540 DeclContext::lookup_result Lookup = RT->getDecl()->lookup(FieldName);
2541 for (NamedDecl *ND : Lookup) {
2542 if (auto *FD = dyn_cast<FieldDecl>(ND)) {
2543 KnownField = FD;
2544 break;
2545 }
2546 if (auto *IFD = dyn_cast<IndirectFieldDecl>(ND)) {
2547 // In verify mode, don't modify the original.
2548 if (VerifyOnly)
2549 DIE = CloneDesignatedInitExpr(SemaRef, DIE);
2550 ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, IFD);
2551 D = DIE->getDesignator(DesigIdx);
2552 KnownField = cast<FieldDecl>(*IFD->chain_begin());
2553 break;
2554 }
2555 }
2556 if (!KnownField) {
2557 if (VerifyOnly) {
2558 ++Index;
2559 return true; // No typo correction when just trying this out.
2560 }
2561
2562 // Name lookup found something, but it wasn't a field.
2563 if (!Lookup.empty()) {
2564 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_nonfield)
2565 << FieldName;
2566 SemaRef.Diag(Lookup.front()->getLocation(),
2567 diag::note_field_designator_found);
2568 ++Index;
2569 return true;
2570 }
2571
2572 // Name lookup didn't find anything.
2573 // Determine whether this was a typo for another field name.
2574 FieldInitializerValidatorCCC CCC(RT->getDecl());
2575 if (TypoCorrection Corrected = SemaRef.CorrectTypo(
2576 DeclarationNameInfo(FieldName, D->getFieldLoc()),
2577 Sema::LookupMemberName, /*Scope=*/nullptr, /*SS=*/nullptr, CCC,
2578 Sema::CTK_ErrorRecovery, RT->getDecl())) {
2579 SemaRef.diagnoseTypo(
2580 Corrected,
2581 SemaRef.PDiag(diag::err_field_designator_unknown_suggest)
2582 << FieldName << CurrentObjectType);
2583 KnownField = Corrected.getCorrectionDeclAs<FieldDecl>();
2584 hadError = true;
2585 } else {
2586 // Typo correction didn't find anything.
2587 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown)
2588 << FieldName << CurrentObjectType;
2589 ++Index;
2590 return true;
2591 }
2592 }
2593 }
2594
2595 unsigned NumBases = 0;
2596 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
2597 NumBases = CXXRD->getNumBases();
2598
2599 unsigned FieldIndex = NumBases;
2600
2601 for (auto *FI : RT->getDecl()->fields()) {
2602 if (FI->isUnnamedBitfield())
2603 continue;
2604 if (declaresSameEntity(KnownField, FI)) {
2605 KnownField = FI;
2606 break;
2607 }
2608 ++FieldIndex;
2609 }
2610
2611 RecordDecl::field_iterator Field =
2612 RecordDecl::field_iterator(DeclContext::decl_iterator(KnownField));
2613
2614 // All of the fields of a union are located at the same place in
2615 // the initializer list.
2616 if (RT->getDecl()->isUnion()) {
2617 FieldIndex = 0;
2618 if (StructuredList) {
2619 FieldDecl *CurrentField = StructuredList->getInitializedFieldInUnion();
2620 if (CurrentField && !declaresSameEntity(CurrentField, *Field)) {
2621 assert(StructuredList->getNumInits() == 1((void)0)
2622 && "A union should never have more than one initializer!")((void)0);
2623
2624 Expr *ExistingInit = StructuredList->getInit(0);
2625 if (ExistingInit) {
2626 // We're about to throw away an initializer, emit warning.
2627 diagnoseInitOverride(
2628 ExistingInit, SourceRange(D->getBeginLoc(), DIE->getEndLoc()));
2629 }
2630
2631 // remove existing initializer
2632 StructuredList->resizeInits(SemaRef.Context, 0);
2633 StructuredList->setInitializedFieldInUnion(nullptr);
2634 }
2635
2636 StructuredList->setInitializedFieldInUnion(*Field);
2637 }
2638 }
2639
2640 // Make sure we can use this declaration.
2641 bool InvalidUse;
2642 if (VerifyOnly)
2643 InvalidUse = !SemaRef.CanUseDecl(*Field, TreatUnavailableAsInvalid);
2644 else
2645 InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field, D->getFieldLoc());
2646 if (InvalidUse) {
2647 ++Index;
2648 return true;
2649 }
2650
2651 // C++20 [dcl.init.list]p3:
2652 // The ordered identifiers in the designators of the designated-
2653 // initializer-list shall form a subsequence of the ordered identifiers
2654 // in the direct non-static data members of T.
2655 //
2656 // Note that this is not a condition on forming the aggregate
2657 // initialization, only on actually performing initialization,
2658 // so it is not checked in VerifyOnly mode.
2659 //
2660 // FIXME: This is the only reordering diagnostic we produce, and it only
2661 // catches cases where we have a top-level field designator that jumps
2662 // backwards. This is the only such case that is reachable in an
2663 // otherwise-valid C++20 program, so is the only case that's required for
2664 // conformance, but for consistency, we should diagnose all the other
2665 // cases where a designator takes us backwards too.
2666 if (IsFirstDesignator && !VerifyOnly && SemaRef.getLangOpts().CPlusPlus &&
2667 NextField &&
2668 (*NextField == RT->getDecl()->field_end() ||
2669 (*NextField)->getFieldIndex() > Field->getFieldIndex() + 1)) {
2670 // Find the field that we just initialized.
2671 FieldDecl *PrevField = nullptr;
2672 for (auto FI = RT->getDecl()->field_begin();
2673 FI != RT->getDecl()->field_end(); ++FI) {
2674 if (FI->isUnnamedBitfield())
2675 continue;
2676 if (*NextField != RT->getDecl()->field_end() &&
2677 declaresSameEntity(*FI, **NextField))
2678 break;
2679 PrevField = *FI;
2680 }
2681
2682 if (PrevField &&
2683 PrevField->getFieldIndex() > KnownField->getFieldIndex()) {
2684 SemaRef.Diag(DIE->getBeginLoc(), diag::ext_designated_init_reordered)
2685 << KnownField << PrevField << DIE->getSourceRange();
2686
2687 unsigned OldIndex = NumBases + PrevField->getFieldIndex();
2688 if (StructuredList && OldIndex <= StructuredList->getNumInits()) {
2689 if (Expr *PrevInit = StructuredList->getInit(OldIndex)) {
2690 SemaRef.Diag(PrevInit->getBeginLoc(),
2691 diag::note_previous_field_init)
2692 << PrevField << PrevInit->getSourceRange();
2693 }
2694 }
2695 }
2696 }
2697
2698
2699 // Update the designator with the field declaration.
2700 if (!VerifyOnly)
2701 D->setField(*Field);
2702
2703 // Make sure that our non-designated initializer list has space
2704 // for a subobject corresponding to this field.
2705 if (StructuredList && FieldIndex >= StructuredList->getNumInits())
2706 StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1);
2707
2708 // This designator names a flexible array member.
2709 if (Field->getType()->isIncompleteArrayType()) {
2710 bool Invalid = false;
2711 if ((DesigIdx + 1) != DIE->size()) {
2712 // We can't designate an object within the flexible array
2713 // member (because GCC doesn't allow it).
2714 if (!VerifyOnly) {
2715 DesignatedInitExpr::Designator *NextD
2716 = DIE->getDesignator(DesigIdx + 1);
2717 SemaRef.Diag(NextD->getBeginLoc(),
2718 diag::err_designator_into_flexible_array_member)
2719 << SourceRange(NextD->getBeginLoc(), DIE->getEndLoc());
2720 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
2721 << *Field;
2722 }
2723 Invalid = true;
2724 }
2725
2726 if (!hadError && !isa<InitListExpr>(DIE->getInit()) &&
2727 !isa<StringLiteral>(DIE->getInit())) {
2728 // The initializer is not an initializer list.
2729 if (!VerifyOnly) {
2730 SemaRef.Diag(DIE->getInit()->getBeginLoc(),
2731 diag::err_flexible_array_init_needs_braces)
2732 << DIE->getInit()->getSourceRange();
2733 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
2734 << *Field;
2735 }
2736 Invalid = true;
2737 }
2738
2739 // Check GNU flexible array initializer.
2740 if (!Invalid && CheckFlexibleArrayInit(Entity, DIE->getInit(), *Field,
2741 TopLevelObject))
2742 Invalid = true;
2743
2744 if (Invalid) {
2745 ++Index;
2746 return true;
2747 }
2748
2749 // Initialize the array.
2750 bool prevHadError = hadError;
2751 unsigned newStructuredIndex = FieldIndex;
2752 unsigned OldIndex = Index;
2753 IList->setInit(Index, DIE->getInit());
2754
2755 InitializedEntity MemberEntity =
2756 InitializedEntity::InitializeMember(*Field, &Entity);
2757 CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
2758 StructuredList, newStructuredIndex);
2759
2760 IList->setInit(OldIndex, DIE);
2761 if (hadError && !prevHadError) {
2762 ++Field;
2763 ++FieldIndex;
2764 if (NextField)
2765 *NextField = Field;
2766 StructuredIndex = FieldIndex;
2767 return true;
2768 }
2769 } else {
2770 // Recurse to check later designated subobjects.
2771 QualType FieldType = Field->getType();
2772 unsigned newStructuredIndex = FieldIndex;
2773
2774 InitializedEntity MemberEntity =
2775 InitializedEntity::InitializeMember(*Field, &Entity);
2776 if (CheckDesignatedInitializer(MemberEntity, IList, DIE, DesigIdx + 1,
2777 FieldType, nullptr, nullptr, Index,
2778 StructuredList, newStructuredIndex,
2779 FinishSubobjectInit, false))
2780 return true;
2781 }
2782
2783 // Find the position of the next field to be initialized in this
2784 // subobject.
2785 ++Field;
2786 ++FieldIndex;
2787
2788 // If this the first designator, our caller will continue checking
2789 // the rest of this struct/class/union subobject.
2790 if (IsFirstDesignator) {
2791 if (NextField)
2792 *NextField = Field;
2793 StructuredIndex = FieldIndex;
2794 return false;
2795 }
2796
2797 if (!FinishSubobjectInit)
2798 return false;
2799
2800 // We've already initialized something in the union; we're done.
2801 if (RT->getDecl()->isUnion())
2802 return hadError;
2803
2804 // Check the remaining fields within this class/struct/union subobject.
2805 bool prevHadError = hadError;
2806
2807 auto NoBases =
2808 CXXRecordDecl::base_class_range(CXXRecordDecl::base_class_iterator(),
2809 CXXRecordDecl::base_class_iterator());
2810 CheckStructUnionTypes(Entity, IList, CurrentObjectType, NoBases, Field,
2811 false, Index, StructuredList, FieldIndex);
2812 return hadError && !prevHadError;
2813 }
2814
2815 // C99 6.7.8p6:
2816 //
2817 // If a designator has the form
2818 //
2819 // [ constant-expression ]
2820 //
2821 // then the current object (defined below) shall have array
2822 // type and the expression shall be an integer constant
2823 // expression. If the array is of unknown size, any
2824 // nonnegative value is valid.
2825 //
2826 // Additionally, cope with the GNU extension that permits
2827 // designators of the form
2828 //
2829 // [ constant-expression ... constant-expression ]
2830 const ArrayType *AT = SemaRef.Context.getAsArrayType(CurrentObjectType);
2831 if (!AT) {
2832 if (!VerifyOnly)
2833 SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array)
2834 << CurrentObjectType;
2835 ++Index;
2836 return true;
2837 }
2838
2839 Expr *IndexExpr = nullptr;
2840 llvm::APSInt DesignatedStartIndex, DesignatedEndIndex;
2841 if (D->isArrayDesignator()) {
2842 IndexExpr = DIE->getArrayIndex(*D);
2843 DesignatedStartIndex = IndexExpr->EvaluateKnownConstInt(SemaRef.Context);
2844 DesignatedEndIndex = DesignatedStartIndex;
2845 } else {
2846 assert(D->isArrayRangeDesignator() && "Need array-range designator")((void)0);
2847
2848 DesignatedStartIndex =
2849 DIE->getArrayRangeStart(*D)->EvaluateKnownConstInt(SemaRef.Context);
2850 DesignatedEndIndex =
2851 DIE->getArrayRangeEnd(*D)->EvaluateKnownConstInt(SemaRef.Context);
2852 IndexExpr = DIE->getArrayRangeEnd(*D);
2853
2854 // Codegen can't handle evaluating array range designators that have side
2855 // effects, because we replicate the AST value for each initialized element.
2856 // As such, set the sawArrayRangeDesignator() bit if we initialize multiple
2857 // elements with something that has a side effect, so codegen can emit an
2858 // "error unsupported" error instead of miscompiling the app.
2859 if (DesignatedStartIndex.getZExtValue()!=DesignatedEndIndex.getZExtValue()&&
2860 DIE->getInit()->HasSideEffects(SemaRef.Context) && !VerifyOnly)
2861 FullyStructuredList->sawArrayRangeDesignator();
2862 }
2863
2864 if (isa<ConstantArrayType>(AT)) {
2865 llvm::APSInt MaxElements(cast<ConstantArrayType>(AT)->getSize(), false);
2866 DesignatedStartIndex
2867 = DesignatedStartIndex.extOrTrunc(MaxElements.getBitWidth());
2868 DesignatedStartIndex.setIsUnsigned(MaxElements.isUnsigned());
2869 DesignatedEndIndex
2870 = DesignatedEndIndex.extOrTrunc(MaxElements.getBitWidth());
2871 DesignatedEndIndex.setIsUnsigned(MaxElements.isUnsigned());
2872 if (DesignatedEndIndex >= MaxElements) {
2873 if (!VerifyOnly)
2874 SemaRef.Diag(IndexExpr->getBeginLoc(),
2875 diag::err_array_designator_too_large)
2876 << toString(DesignatedEndIndex, 10) << toString(MaxElements, 10)
2877 << IndexExpr->getSourceRange();
2878 ++Index;
2879 return true;
2880 }
2881 } else {
2882 unsigned DesignatedIndexBitWidth =
2883 ConstantArrayType::getMaxSizeBits(SemaRef.Context);
2884 DesignatedStartIndex =
2885 DesignatedStartIndex.extOrTrunc(DesignatedIndexBitWidth);
2886 DesignatedEndIndex =
2887 DesignatedEndIndex.extOrTrunc(DesignatedIndexBitWidth);
2888 DesignatedStartIndex.setIsUnsigned(true);
2889 DesignatedEndIndex.setIsUnsigned(true);
2890 }
2891
2892 bool IsStringLiteralInitUpdate =
2893 StructuredList && StructuredList->isStringLiteralInit();
2894 if (IsStringLiteralInitUpdate && VerifyOnly) {
2895 // We're just verifying an update to a string literal init. We don't need
2896 // to split the string up into individual characters to do that.
2897 StructuredList = nullptr;
2898 } else if (IsStringLiteralInitUpdate) {
2899 // We're modifying a string literal init; we have to decompose the string
2900 // so we can modify the individual characters.
2901 ASTContext &Context = SemaRef.Context;
2902 Expr *SubExpr = StructuredList->getInit(0)->IgnoreParens();
2903
2904 // Compute the character type
2905 QualType CharTy = AT->getElementType();
2906
2907 // Compute the type of the integer literals.
2908 QualType PromotedCharTy = CharTy;
2909 if (CharTy->isPromotableIntegerType())
2910 PromotedCharTy = Context.getPromotedIntegerType(CharTy);
2911 unsigned PromotedCharTyWidth = Context.getTypeSize(PromotedCharTy);
2912
2913 if (StringLiteral *SL = dyn_cast<StringLiteral>(SubExpr)) {
2914 // Get the length of the string.
2915 uint64_t StrLen = SL->getLength();
2916 if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen))
2917 StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue();
2918 StructuredList->resizeInits(Context, StrLen);
2919
2920 // Build a literal for each character in the string, and put them into
2921 // the init list.
2922 for (unsigned i = 0, e = StrLen; i != e; ++i) {
2923 llvm::APInt CodeUnit(PromotedCharTyWidth, SL->getCodeUnit(i));
2924 Expr *Init = new (Context) IntegerLiteral(
2925 Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc());
2926 if (CharTy != PromotedCharTy)
2927 Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast,
2928 Init, nullptr, VK_PRValue,
2929 FPOptionsOverride());
2930 StructuredList->updateInit(Context, i, Init);
2931 }
2932 } else {
2933 ObjCEncodeExpr *E = cast<ObjCEncodeExpr>(SubExpr);
2934 std::string Str;
2935 Context.getObjCEncodingForType(E->getEncodedType(), Str);
2936
2937 // Get the length of the string.
2938 uint64_t StrLen = Str.size();
2939 if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen))
2940 StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue();
2941 StructuredList->resizeInits(Context, StrLen);
2942
2943 // Build a literal for each character in the string, and put them into
2944 // the init list.
2945 for (unsigned i = 0, e = StrLen; i != e; ++i) {
2946 llvm::APInt CodeUnit(PromotedCharTyWidth, Str[i]);
2947 Expr *Init = new (Context) IntegerLiteral(
2948 Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc());
2949 if (CharTy != PromotedCharTy)
2950 Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast,
2951 Init, nullptr, VK_PRValue,
2952 FPOptionsOverride());
2953 StructuredList->updateInit(Context, i, Init);
2954 }
2955 }
2956 }
2957
2958 // Make sure that our non-designated initializer list has space
2959 // for a subobject corresponding to this array element.
2960 if (StructuredList &&
2961 DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits())
2962 StructuredList->resizeInits(SemaRef.Context,
2963 DesignatedEndIndex.getZExtValue() + 1);
2964
2965 // Repeatedly perform subobject initializations in the range
2966 // [DesignatedStartIndex, DesignatedEndIndex].
2967
2968 // Move to the next designator
2969 unsigned ElementIndex = DesignatedStartIndex.getZExtValue();
2970 unsigned OldIndex = Index;
2971
2972 InitializedEntity ElementEntity =
2973 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
2974
2975 while (DesignatedStartIndex <= DesignatedEndIndex) {
2976 // Recurse to check later designated subobjects.
2977 QualType ElementType = AT->getElementType();
2978 Index = OldIndex;
2979
2980 ElementEntity.setElementIndex(ElementIndex);
2981 if (CheckDesignatedInitializer(
2982 ElementEntity, IList, DIE, DesigIdx + 1, ElementType, nullptr,
2983 nullptr, Index, StructuredList, ElementIndex,
2984 FinishSubobjectInit && (DesignatedStartIndex == DesignatedEndIndex),
2985 false))
2986 return true;
2987
2988 // Move to the next index in the array that we'll be initializing.
2989 ++DesignatedStartIndex;
2990 ElementIndex = DesignatedStartIndex.getZExtValue();
2991 }
2992
2993 // If this the first designator, our caller will continue checking
2994 // the rest of this array subobject.
2995 if (IsFirstDesignator) {
2996 if (NextElementIndex)
2997 *NextElementIndex = DesignatedStartIndex;
2998 StructuredIndex = ElementIndex;
2999 return false;
3000 }
3001
3002 if (!FinishSubobjectInit)
3003 return false;
3004
3005 // Check the remaining elements within this array subobject.
3006 bool prevHadError = hadError;
3007 CheckArrayType(Entity, IList, CurrentObjectType, DesignatedStartIndex,
3008 /*SubobjectIsDesignatorContext=*/false, Index,
3009 StructuredList, ElementIndex);
3010 return hadError && !prevHadError;
3011}
3012
3013// Get the structured initializer list for a subobject of type
3014// @p CurrentObjectType.
3015InitListExpr *
3016InitListChecker::getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
3017 QualType CurrentObjectType,
3018 InitListExpr *StructuredList,
3019 unsigned StructuredIndex,
3020 SourceRange InitRange,
3021 bool IsFullyOverwritten) {
3022 if (!StructuredList)
3023 return nullptr;
3024
3025 Expr *ExistingInit = nullptr;
3026 if (StructuredIndex < StructuredList->getNumInits())
3027 ExistingInit = StructuredList->getInit(StructuredIndex);
3028
3029 if (InitListExpr *Result = dyn_cast_or_null<InitListExpr>(ExistingInit))
3030 // There might have already been initializers for subobjects of the current
3031 // object, but a subsequent initializer list will overwrite the entirety
3032 // of the current object. (See DR 253 and C99 6.7.8p21). e.g.,
3033 //
3034 // struct P { char x[6]; };
3035 // struct P l = { .x[2] = 'x', .x = { [0] = 'f' } };
3036 //
3037 // The first designated initializer is ignored, and l.x is just "f".
3038 if (!IsFullyOverwritten)
3039 return Result;
3040
3041 if (ExistingInit) {
3042 // We are creating an initializer list that initializes the
3043 // subobjects of the current object, but there was already an
3044 // initialization that completely initialized the current
3045 // subobject:
3046 //
3047 // struct X { int a, b; };
3048 // struct X xs[] = { [0] = { 1, 2 }, [0].b = 3 };
3049 //
3050 // Here, xs[0].a == 1 and xs[0].b == 3, since the second,
3051 // designated initializer overwrites the [0].b initializer
3052 // from the prior initialization.
3053 //
3054 // When the existing initializer is an expression rather than an
3055 // initializer list, we cannot decompose and update it in this way.
3056 // For example:
3057 //
3058 // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 };
3059 //
3060 // This case is handled by CheckDesignatedInitializer.
3061 diagnoseInitOverride(ExistingInit, InitRange);
3062 }
3063
3064 unsigned ExpectedNumInits = 0;
3065 if (Index < IList->getNumInits()) {
3066 if (auto *Init = dyn_cast_or_null<InitListExpr>(IList->getInit(Index)))
3067 ExpectedNumInits = Init->getNumInits();
3068 else
3069 ExpectedNumInits = IList->getNumInits() - Index;
3070 }
3071
3072 InitListExpr *Result =
3073 createInitListExpr(CurrentObjectType, InitRange, ExpectedNumInits);
3074
3075 // Link this new initializer list into the structured initializer
3076 // lists.
3077 StructuredList->updateInit(SemaRef.Context, StructuredIndex, Result);
3078 return Result;
3079}
3080
3081InitListExpr *
3082InitListChecker::createInitListExpr(QualType CurrentObjectType,
3083 SourceRange InitRange,
3084 unsigned ExpectedNumInits) {
3085 InitListExpr *Result
3086 = new (SemaRef.Context) InitListExpr(SemaRef.Context,
3087 InitRange.getBegin(), None,
3088 InitRange.getEnd());
3089
3090 QualType ResultType = CurrentObjectType;
3091 if (!ResultType->isArrayType())
3092 ResultType = ResultType.getNonLValueExprType(SemaRef.Context);
3093 Result->setType(ResultType);
3094
3095 // Pre-allocate storage for the structured initializer list.
3096 unsigned NumElements = 0;
3097
3098 if (const ArrayType *AType
3099 = SemaRef.Context.getAsArrayType(CurrentObjectType)) {
3100 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) {
3101 NumElements = CAType->getSize().getZExtValue();
3102 // Simple heuristic so that we don't allocate a very large
3103 // initializer with many empty entries at the end.
3104 if (NumElements > ExpectedNumInits)
3105 NumElements = 0;
3106 }
3107 } else if (const VectorType *VType = CurrentObjectType->getAs<VectorType>()) {
3108 NumElements = VType->getNumElements();
3109 } else if (CurrentObjectType->isRecordType()) {
3110 NumElements = numStructUnionElements(CurrentObjectType);
3111 }
3112
3113 Result->reserveInits(SemaRef.Context, NumElements);
3114
3115 return Result;
3116}
3117
3118/// Update the initializer at index @p StructuredIndex within the
3119/// structured initializer list to the value @p expr.
3120void InitListChecker::UpdateStructuredListElement(InitListExpr *StructuredList,
3121 unsigned &StructuredIndex,
3122 Expr *expr) {
3123 // No structured initializer list to update
3124 if (!StructuredList)
3125 return;
3126
3127 if (Expr *PrevInit = StructuredList->updateInit(SemaRef.Context,
3128 StructuredIndex, expr)) {
3129 // This initializer overwrites a previous initializer.
3130 // No need to diagnose when `expr` is nullptr because a more relevant
3131 // diagnostic has already been issued and this diagnostic is potentially
3132 // noise.
3133 if (expr)
3134 diagnoseInitOverride(PrevInit, expr->getSourceRange());
3135 }
3136
3137 ++StructuredIndex;
3138}
3139
3140/// Determine whether we can perform aggregate initialization for the purposes
3141/// of overload resolution.
3142bool Sema::CanPerformAggregateInitializationForOverloadResolution(
3143 const InitializedEntity &Entity, InitListExpr *From) {
3144 QualType Type = Entity.getType();
3145 InitListChecker Check(*this, Entity, From, Type, /*VerifyOnly=*/true,
3146 /*TreatUnavailableAsInvalid=*/false,
3147 /*InOverloadResolution=*/true);
3148 return !Check.HadError();
3149}
3150
3151/// Check that the given Index expression is a valid array designator
3152/// value. This is essentially just a wrapper around
3153/// VerifyIntegerConstantExpression that also checks for negative values
3154/// and produces a reasonable diagnostic if there is a
3155/// failure. Returns the index expression, possibly with an implicit cast
3156/// added, on success. If everything went okay, Value will receive the
3157/// value of the constant expression.
3158static ExprResult
3159CheckArrayDesignatorExpr(Sema &S, Expr *Index, llvm::APSInt &Value) {
3160 SourceLocation Loc = Index->getBeginLoc();
3161
3162 // Make sure this is an integer constant expression.
3163 ExprResult Result =
3164 S.VerifyIntegerConstantExpression(Index, &Value, Sema::AllowFold);
3165 if (Result.isInvalid())
3166 return Result;
3167
3168 if (Value.isSigned() && Value.isNegative())
3169 return S.Diag(Loc, diag::err_array_designator_negative)
3170 << toString(Value, 10) << Index->getSourceRange();
3171
3172 Value.setIsUnsigned(true);
3173 return Result;
3174}
3175
3176ExprResult Sema::ActOnDesignatedInitializer(Designation &Desig,
3177 SourceLocation EqualOrColonLoc,
3178 bool GNUSyntax,
3179 ExprResult Init) {
3180 typedef DesignatedInitExpr::Designator ASTDesignator;
3181
3182 bool Invalid = false;
3183 SmallVector<ASTDesignator, 32> Designators;
3184 SmallVector<Expr *, 32> InitExpressions;
3185
3186 // Build designators and check array designator expressions.
3187 for (unsigned Idx = 0; Idx < Desig.getNumDesignators(); ++Idx) {
3188 const Designator &D = Desig.getDesignator(Idx);
3189 switch (D.getKind()) {
3190 case Designator::FieldDesignator:
3191 Designators.push_back(ASTDesignator(D.getField(), D.getDotLoc(),
3192 D.getFieldLoc()));
3193 break;
3194
3195 case Designator::ArrayDesignator: {
3196 Expr *Index = static_cast<Expr *>(D.getArrayIndex());
3197 llvm::APSInt IndexValue;
3198 if (!Index->isTypeDependent() && !Index->isValueDependent())
3199 Index = CheckArrayDesignatorExpr(*this, Index, IndexValue).get();
3200 if (!Index)
3201 Invalid = true;
3202 else {
3203 Designators.push_back(ASTDesignator(InitExpressions.size(),
3204 D.getLBracketLoc(),
3205 D.getRBracketLoc()));
3206 InitExpressions.push_back(Index);
3207 }
3208 break;
3209 }
3210
3211 case Designator::ArrayRangeDesignator: {
3212 Expr *StartIndex = static_cast<Expr *>(D.getArrayRangeStart());
3213 Expr *EndIndex = static_cast<Expr *>(D.getArrayRangeEnd());
3214 llvm::APSInt StartValue;
3215 llvm::APSInt EndValue;
3216 bool StartDependent = StartIndex->isTypeDependent() ||
3217 StartIndex->isValueDependent();
3218 bool EndDependent = EndIndex->isTypeDependent() ||
3219 EndIndex->isValueDependent();
3220 if (!StartDependent)
3221 StartIndex =
3222 CheckArrayDesignatorExpr(*this, StartIndex, StartValue).get();
3223 if (!EndDependent)
3224 EndIndex = CheckArrayDesignatorExpr(*this, EndIndex, EndValue).get();
3225
3226 if (!StartIndex || !EndIndex)
3227 Invalid = true;
3228 else {
3229 // Make sure we're comparing values with the same bit width.
3230 if (StartDependent || EndDependent) {
3231 // Nothing to compute.
3232 } else if (StartValue.getBitWidth() > EndValue.getBitWidth())
3233 EndValue = EndValue.extend(StartValue.getBitWidth());
3234 else if (StartValue.getBitWidth() < EndValue.getBitWidth())
3235 StartValue = StartValue.extend(EndValue.getBitWidth());
3236
3237 if (!StartDependent && !EndDependent && EndValue < StartValue) {
3238 Diag(D.getEllipsisLoc(), diag::err_array_designator_empty_range)
3239 << toString(StartValue, 10) << toString(EndValue, 10)
3240 << StartIndex->getSourceRange() << EndIndex->getSourceRange();
3241 Invalid = true;
3242 } else {
3243 Designators.push_back(ASTDesignator(InitExpressions.size(),
3244 D.getLBracketLoc(),
3245 D.getEllipsisLoc(),
3246 D.getRBracketLoc()));
3247 InitExpressions.push_back(StartIndex);
3248 InitExpressions.push_back(EndIndex);
3249 }
3250 }
3251 break;
3252 }
3253 }
3254 }
3255
3256 if (Invalid || Init.isInvalid())
3257 return ExprError();
3258
3259 // Clear out the expressions within the designation.
3260 Desig.ClearExprs(*this);
3261
3262 return DesignatedInitExpr::Create(Context, Designators, InitExpressions,
3263 EqualOrColonLoc, GNUSyntax,
3264 Init.getAs<Expr>());
3265}
3266
3267//===----------------------------------------------------------------------===//
3268// Initialization entity
3269//===----------------------------------------------------------------------===//
3270
3271InitializedEntity::InitializedEntity(ASTContext &Context, unsigned Index,
3272 const InitializedEntity &Parent)
3273 : Parent(&Parent), Index(Index)
3274{
3275 if (const ArrayType *AT = Context.getAsArrayType(Parent.getType())) {
3276 Kind = EK_ArrayElement;
3277 Type = AT->getElementType();
3278 } else if (const VectorType *VT = Parent.getType()->getAs<VectorType>()) {
3279 Kind = EK_VectorElement;
3280 Type = VT->getElementType();
3281 } else {
3282 const ComplexType *CT = Parent.getType()->getAs<ComplexType>();
3283 assert(CT && "Unexpected type")((void)0);
3284 Kind = EK_ComplexElement;
3285 Type = CT->getElementType();
3286 }
3287}
3288
3289InitializedEntity
3290InitializedEntity::InitializeBase(ASTContext &Context,
3291 const CXXBaseSpecifier *Base,
3292 bool IsInheritedVirtualBase,
3293 const InitializedEntity *Parent) {
3294 InitializedEntity Result;
3295 Result.Kind = EK_Base;
3296 Result.Parent = Parent;
3297 Result.Base = {Base, IsInheritedVirtualBase};
3298 Result.Type = Base->getType();
3299 return Result;
3300}
3301
3302DeclarationName InitializedEntity::getName() const {
3303 switch (getKind()) {
3304 case EK_Parameter:
3305 case EK_Parameter_CF_Audited: {
3306 ParmVarDecl *D = Parameter.getPointer();
3307 return (D ? D->getDeclName() : DeclarationName());
3308 }
3309
3310 case EK_Variable:
3311 case EK_Member:
3312 case EK_Binding:
3313 case EK_TemplateParameter:
3314 return Variable.VariableOrMember->getDeclName();
3315
3316 case EK_LambdaCapture:
3317 return DeclarationName(Capture.VarID);
3318
3319 case EK_Result:
3320 case EK_StmtExprResult:
3321 case EK_Exception:
3322 case EK_New:
3323 case EK_Temporary:
3324 case EK_Base:
3325 case EK_Delegating:
3326 case EK_ArrayElement:
3327 case EK_VectorElement:
3328 case EK_ComplexElement:
3329 case EK_BlockElement:
3330 case EK_LambdaToBlockConversionBlockElement:
3331 case EK_CompoundLiteralInit:
3332 case EK_RelatedResult:
3333 return DeclarationName();
3334 }
3335
3336 llvm_unreachable("Invalid EntityKind!")__builtin_unreachable();
3337}
3338
3339ValueDecl *InitializedEntity::getDecl() const {
3340 switch (getKind()) {
3341 case EK_Variable:
3342 case EK_Member:
3343 case EK_Binding:
3344 case EK_TemplateParameter:
3345 return Variable.VariableOrMember;
3346
3347 case EK_Parameter:
3348 case EK_Parameter_CF_Audited:
3349 return Parameter.getPointer();
3350
3351 case EK_Result:
3352 case EK_StmtExprResult:
3353 case EK_Exception:
3354 case EK_New:
3355 case EK_Temporary:
3356 case EK_Base:
3357 case EK_Delegating:
3358 case EK_ArrayElement:
3359 case EK_VectorElement:
3360 case EK_ComplexElement:
3361 case EK_BlockElement:
3362 case EK_LambdaToBlockConversionBlockElement:
3363 case EK_LambdaCapture:
3364 case EK_CompoundLiteralInit:
3365 case EK_RelatedResult:
3366 return nullptr;
3367 }
3368
3369 llvm_unreachable("Invalid EntityKind!")__builtin_unreachable();
3370}
3371
3372bool InitializedEntity::allowsNRVO() const {
3373 switch (getKind()) {
3374 case EK_Result:
3375 case EK_Exception:
3376 return LocAndNRVO.NRVO;
3377
3378 case EK_StmtExprResult:
3379 case EK_Variable:
3380 case EK_Parameter:
3381 case EK_Parameter_CF_Audited:
3382 case EK_TemplateParameter:
3383 case EK_Member:
3384 case EK_Binding:
3385 case EK_New:
3386 case EK_Temporary:
3387 case EK_CompoundLiteralInit:
3388 case EK_Base:
3389 case EK_Delegating:
3390 case EK_ArrayElement:
3391 case EK_VectorElement:
3392 case EK_ComplexElement:
3393 case EK_BlockElement:
3394 case EK_LambdaToBlockConversionBlockElement:
3395 case EK_LambdaCapture:
3396 case EK_RelatedResult:
3397 break;
3398 }
3399
3400 return false;
3401}
3402
3403unsigned InitializedEntity::dumpImpl(raw_ostream &OS) const {
3404 assert(getParent() != this)((void)0);
3405 unsigned Depth = getParent() ? getParent()->dumpImpl(OS) : 0;
3406 for (unsigned I = 0; I != Depth; ++I)
3407 OS << "`-";
3408
3409 switch (getKind()) {
3410 case EK_Variable: OS << "Variable"; break;
3411 case EK_Parameter: OS << "Parameter"; break;
3412 case EK_Parameter_CF_Audited: OS << "CF audited function Parameter";
3413 break;
3414 case EK_TemplateParameter: OS << "TemplateParameter"; break;
3415 case EK_Result: OS << "Result"; break;
3416 case EK_StmtExprResult: OS << "StmtExprResult"; break;
3417 case EK_Exception: OS << "Exception"; break;
3418 case EK_Member: OS << "Member"; break;
3419 case EK_Binding: OS << "Binding"; break;
3420 case EK_New: OS << "New"; break;
3421 case EK_Temporary: OS << "Temporary"; break;
3422 case EK_CompoundLiteralInit: OS << "CompoundLiteral";break;
3423 case EK_RelatedResult: OS << "RelatedResult"; break;
3424 case EK_Base: OS << "Base"; break;
3425 case EK_Delegating: OS << "Delegating"; break;
3426 case EK_ArrayElement: OS << "ArrayElement " << Index; break;
3427 case EK_VectorElement: OS << "VectorElement " << Index; break;
3428 case EK_ComplexElement: OS << "ComplexElement " << Index; break;
3429 case EK_BlockElement: OS << "Block"; break;
3430 case EK_LambdaToBlockConversionBlockElement:
3431 OS << "Block (lambda)";
3432 break;
3433 case EK_LambdaCapture:
3434 OS << "LambdaCapture ";
3435 OS << DeclarationName(Capture.VarID);
3436 break;
3437 }
3438
3439 if (auto *D = getDecl()) {
3440 OS << " ";
3441 D->printQualifiedName(OS);
3442 }
3443
3444 OS << " '" << getType().getAsString() << "'\n";
3445
3446 return Depth + 1;
3447}
3448
3449LLVM_DUMP_METHOD__attribute__((noinline)) void InitializedEntity::dump() const {
3450 dumpImpl(llvm::errs());
3451}
3452
3453//===----------------------------------------------------------------------===//
3454// Initialization sequence
3455//===----------------------------------------------------------------------===//
3456
3457void InitializationSequence::Step::Destroy() {
3458 switch (Kind) {
3459 case SK_ResolveAddressOfOverloadedFunction:
3460 case SK_CastDerivedToBasePRValue:
3461 case SK_CastDerivedToBaseXValue:
3462 case SK_CastDerivedToBaseLValue:
3463 case SK_BindReference:
3464 case SK_BindReferenceToTemporary:
3465 case SK_FinalCopy:
3466 case SK_ExtraneousCopyToTemporary:
3467 case SK_UserConversion:
3468 case SK_QualificationConversionPRValue:
3469 case SK_QualificationConversionXValue:
3470 case SK_QualificationConversionLValue:
3471 case SK_FunctionReferenceConversion:
3472 case SK_AtomicConversion:
3473 case SK_ListInitialization:
3474 case SK_UnwrapInitList:
3475 case SK_RewrapInitList:
3476 case SK_ConstructorInitialization:
3477 case SK_ConstructorInitializationFromList:
3478 case SK_ZeroInitialization:
3479 case SK_CAssignment:
3480 case SK_StringInit:
3481 case SK_ObjCObjectConversion:
3482 case SK_ArrayLoopIndex:
3483 case SK_ArrayLoopInit:
3484 case SK_ArrayInit:
3485 case SK_GNUArrayInit:
3486 case SK_ParenthesizedArrayInit:
3487 case SK_PassByIndirectCopyRestore:
3488 case SK_PassByIndirectRestore:
3489 case SK_ProduceObjCObject:
3490 case SK_StdInitializerList:
3491 case SK_StdInitializerListConstructorCall:
3492 case SK_OCLSamplerInit:
3493 case SK_OCLZeroOpaqueType:
3494 break;
3495
3496 case SK_ConversionSequence:
3497 case SK_ConversionSequenceNoNarrowing:
3498 delete ICS;
3499 }
3500}
3501
3502bool InitializationSequence::isDirectReferenceBinding() const {
3503 // There can be some lvalue adjustments after the SK_BindReference step.
3504 for (auto I = Steps.rbegin(); I != Steps.rend(); ++I) {
3505 if (I->Kind == SK_BindReference)
3506 return true;
3507 if (I->Kind == SK_BindReferenceToTemporary)
3508 return false;
3509 }
3510 return false;
3511}
3512
3513bool InitializationSequence::isAmbiguous() const {
3514 if (!Failed())
3515 return false;
3516
3517 switch (getFailureKind()) {
3518 case FK_TooManyInitsForReference:
3519 case FK_ParenthesizedListInitForReference:
3520 case FK_ArrayNeedsInitList:
3521 case FK_ArrayNeedsInitListOrStringLiteral:
3522 case FK_ArrayNeedsInitListOrWideStringLiteral:
3523 case FK_NarrowStringIntoWideCharArray:
3524 case FK_WideStringIntoCharArray:
3525 case FK_IncompatWideStringIntoWideChar:
3526 case FK_PlainStringIntoUTF8Char:
3527 case FK_UTF8StringIntoPlainChar:
3528 case FK_AddressOfOverloadFailed: // FIXME: Could do better
3529 case FK_NonConstLValueReferenceBindingToTemporary:
3530 case FK_NonConstLValueReferenceBindingToBitfield:
3531 case FK_NonConstLValueReferenceBindingToVectorElement:
3532 case FK_NonConstLValueReferenceBindingToMatrixElement:
3533 case FK_NonConstLValueReferenceBindingToUnrelated:
3534 case FK_RValueReferenceBindingToLValue:
3535 case FK_ReferenceAddrspaceMismatchTemporary:
3536 case FK_ReferenceInitDropsQualifiers:
3537 case FK_ReferenceInitFailed:
3538 case FK_ConversionFailed:
3539 case FK_ConversionFromPropertyFailed:
3540 case FK_TooManyInitsForScalar:
3541 case FK_ParenthesizedListInitForScalar:
3542 case FK_ReferenceBindingToInitList:
3543 case FK_InitListBadDestinationType:
3544 case FK_DefaultInitOfConst:
3545 case FK_Incomplete:
3546 case FK_ArrayTypeMismatch:
3547 case FK_NonConstantArrayInit:
3548 case FK_ListInitializationFailed:
3549 case FK_VariableLengthArrayHasInitializer:
3550 case FK_PlaceholderType:
3551 case FK_ExplicitConstructor:
3552 case FK_AddressOfUnaddressableFunction:
3553 return false;
3554
3555 case FK_ReferenceInitOverloadFailed:
3556 case FK_UserConversionOverloadFailed:
3557 case FK_ConstructorOverloadFailed:
3558 case FK_ListConstructorOverloadFailed:
3559 return FailedOverloadResult == OR_Ambiguous;
3560 }
3561
3562 llvm_unreachable("Invalid EntityKind!")__builtin_unreachable();
3563}
3564
3565bool InitializationSequence::isConstructorInitialization() const {
3566 return !Steps.empty() && Steps.back().Kind == SK_ConstructorInitialization;
3567}
3568
3569void
3570InitializationSequence
3571::AddAddressOverloadResolutionStep(FunctionDecl *Function,
3572 DeclAccessPair Found,
3573 bool HadMultipleCandidates) {
3574 Step S;
3575 S.Kind = SK_ResolveAddressOfOverloadedFunction;
3576 S.Type = Function->getType();
3577 S.Function.HadMultipleCandidates = HadMultipleCandidates;
3578 S.Function.Function = Function;
3579 S.Function.FoundDecl = Found;
3580 Steps.push_back(S);
3581}
3582
3583void InitializationSequence::AddDerivedToBaseCastStep(QualType BaseType,
3584 ExprValueKind VK) {
3585 Step S;
3586 switch (VK) {
3587 case VK_PRValue:
3588 S.Kind = SK_CastDerivedToBasePRValue;
3589 break;
3590 case VK_XValue: S.Kind = SK_CastDerivedToBaseXValue; break;
3591 case VK_LValue: S.Kind = SK_CastDerivedToBaseLValue; break;
3592 }
3593 S.Type = BaseType;
3594 Steps.push_back(S);
3595}
3596
3597void InitializationSequence::AddReferenceBindingStep(QualType T,
3598 bool BindingTemporary) {
3599 Step S;
3600 S.Kind = BindingTemporary? SK_BindReferenceToTemporary : SK_BindReference;
3601 S.Type = T;
3602 Steps.push_back(S);
3603}
3604
3605void InitializationSequence::AddFinalCopy(QualType T) {
3606 Step S;
3607 S.Kind = SK_FinalCopy;
3608 S.Type = T;
3609 Steps.push_back(S);
3610}
3611
3612void InitializationSequence::AddExtraneousCopyToTemporary(QualType T) {
3613 Step S;
3614 S.Kind = SK_ExtraneousCopyToTemporary;
3615 S.Type = T;
3616 Steps.push_back(S);
3617}
3618
3619void
3620InitializationSequence::AddUserConversionStep(FunctionDecl *Function,
3621 DeclAccessPair FoundDecl,
3622 QualType T,
3623 bool HadMultipleCandidates) {
3624 Step S;
3625 S.Kind = SK_UserConversion;
3626 S.Type = T;
3627 S.Function.HadMultipleCandidates = HadMultipleCandidates;
3628 S.Function.Function = Function;
3629 S.Function.FoundDecl = FoundDecl;
3630 Steps.push_back(S);
3631}
3632
3633void InitializationSequence::AddQualificationConversionStep(QualType Ty,
3634 ExprValueKind VK) {
3635 Step S;
3636 S.Kind = SK_QualificationConversionPRValue; // work around a gcc warning
3637 switch (VK) {
3638 case VK_PRValue:
3639 S.Kind = SK_QualificationConversionPRValue;
3640 break;
3641 case VK_XValue:
3642 S.Kind = SK_QualificationConversionXValue;
3643 break;
3644 case VK_LValue:
3645 S.Kind = SK_QualificationConversionLValue;
3646 break;
3647 }
3648 S.Type = Ty;
3649 Steps.push_back(S);
3650}
3651
3652void InitializationSequence::AddFunctionReferenceConversionStep(QualType Ty) {
3653 Step S;
3654 S.Kind = SK_FunctionReferenceConversion;
3655 S.Type = Ty;
3656 Steps.push_back(S);
3657}
3658
3659void InitializationSequence::AddAtomicConversionStep(QualType Ty) {
3660 Step S;
3661 S.Kind = SK_AtomicConversion;
3662 S.Type = Ty;
3663 Steps.push_back(S);
3664}
3665
3666void InitializationSequence::AddConversionSequenceStep(
3667 const ImplicitConversionSequence &ICS, QualType T,
3668 bool TopLevelOfInitList) {
3669 Step S;
3670 S.Kind = TopLevelOfInitList ? SK_ConversionSequenceNoNarrowing
3671 : SK_ConversionSequence;
3672 S.Type = T;
3673 S.ICS = new ImplicitConversionSequence(ICS);
3674 Steps.push_back(S);
3675}
3676
3677void InitializationSequence::AddListInitializationStep(QualType T) {
3678 Step S;
3679 S.Kind = SK_ListInitialization;
3680 S.Type = T;
3681 Steps.push_back(S);
3682}
3683
3684void InitializationSequence::AddConstructorInitializationStep(
3685 DeclAccessPair FoundDecl, CXXConstructorDecl *Constructor, QualType T,
3686 bool HadMultipleCandidates, bool FromInitList, bool AsInitList) {
3687 Step S;
3688 S.Kind = FromInitList ? AsInitList ? SK_StdInitializerListConstructorCall
3689 : SK_ConstructorInitializationFromList
3690 : SK_ConstructorInitialization;
3691 S.Type = T;
3692 S.Function.HadMultipleCandidates = HadMultipleCandidates;
3693 S.Function.Function = Constructor;
3694 S.Function.FoundDecl = FoundDecl;
3695 Steps.push_back(S);
3696}
3697
3698void InitializationSequence::AddZeroInitializationStep(QualType T) {
3699 Step S;
3700 S.Kind = SK_ZeroInitialization;
3701 S.Type = T;
3702 Steps.push_back(S);
3703}
3704
3705void InitializationSequence::AddCAssignmentStep(QualType T) {
3706 Step S;
3707 S.Kind = SK_CAssignment;
3708 S.Type = T;
3709 Steps.push_back(S);
3710}
3711
3712void InitializationSequence::AddStringInitStep(QualType T) {
3713 Step S;
3714 S.Kind = SK_StringInit;
3715 S.Type = T;
3716 Steps.push_back(S);
3717}
3718
3719void InitializationSequence::AddObjCObjectConversionStep(QualType T) {
3720 Step S;
3721 S.Kind = SK_ObjCObjectConversion;
3722 S.Type = T;
3723 Steps.push_back(S);
3724}
3725
3726void InitializationSequence::AddArrayInitStep(QualType T, bool IsGNUExtension) {
3727 Step S;
3728 S.Kind = IsGNUExtension ? SK_GNUArrayInit : SK_ArrayInit;
3729 S.Type = T;
3730 Steps.push_back(S);
3731}
3732
3733void InitializationSequence::AddArrayInitLoopStep(QualType T, QualType EltT) {
3734 Step S;
3735 S.Kind = SK_ArrayLoopIndex;
3736 S.Type = EltT;
3737 Steps.insert(Steps.begin(), S);
3738
3739 S.Kind = SK_ArrayLoopInit;
3740 S.Type = T;
3741 Steps.push_back(S);
3742}
3743
3744void InitializationSequence::AddParenthesizedArrayInitStep(QualType T) {
3745 Step S;
3746 S.Kind = SK_ParenthesizedArrayInit;
3747 S.Type = T;
3748 Steps.push_back(S);
3749}
3750
3751void InitializationSequence::AddPassByIndirectCopyRestoreStep(QualType type,
3752 bool shouldCopy) {
3753 Step s;
3754 s.Kind = (shouldCopy ? SK_PassByIndirectCopyRestore
3755 : SK_PassByIndirectRestore);
3756 s.Type = type;
3757 Steps.push_back(s);
3758}
3759
3760void InitializationSequence::AddProduceObjCObjectStep(QualType T) {
3761 Step S;
3762 S.Kind = SK_ProduceObjCObject;
3763 S.Type = T;
3764 Steps.push_back(S);
3765}
3766
3767void InitializationSequence::AddStdInitializerListConstructionStep(QualType T) {
3768 Step S;
3769 S.Kind = SK_StdInitializerList;
3770 S.Type = T;
3771 Steps.push_back(S);
3772}
3773
3774void InitializationSequence::AddOCLSamplerInitStep(QualType T) {
3775 Step S;
3776 S.Kind = SK_OCLSamplerInit;
3777 S.Type = T;
3778 Steps.push_back(S);
3779}
3780
3781void InitializationSequence::AddOCLZeroOpaqueTypeStep(QualType T) {
3782 Step S;
3783 S.Kind = SK_OCLZeroOpaqueType;
3784 S.Type = T;
3785 Steps.push_back(S);
3786}
3787
3788void InitializationSequence::RewrapReferenceInitList(QualType T,
3789 InitListExpr *Syntactic) {
3790 assert(Syntactic->getNumInits() == 1 &&((void)0)
3791 "Can only rewrap trivial init lists.")((void)0);
3792 Step S;
3793 S.Kind = SK_UnwrapInitList;
3794 S.Type = Syntactic->getInit(0)->getType();
3795 Steps.insert(Steps.begin(), S);
3796
3797 S.Kind = SK_RewrapInitList;
3798 S.Type = T;
3799 S.WrappingSyntacticList = Syntactic;
3800 Steps.push_back(S);
3801}
3802
3803void InitializationSequence::SetOverloadFailure(FailureKind Failure,
3804 OverloadingResult Result) {
3805 setSequenceKind(FailedSequence);
3806 this->Failure = Failure;
3807 this->FailedOverloadResult = Result;
3808}
3809
3810//===----------------------------------------------------------------------===//
3811// Attempt initialization
3812//===----------------------------------------------------------------------===//
3813
3814/// Tries to add a zero initializer. Returns true if that worked.
3815static bool
3816maybeRecoverWithZeroInitialization(Sema &S, InitializationSequence &Sequence,
3817 const InitializedEntity &Entity) {
3818 if (Entity.getKind() != InitializedEntity::EK_Variable)
3819 return false;
3820
3821 VarDecl *VD = cast<VarDecl>(Entity.getDecl());
3822 if (VD->getInit() || VD->getEndLoc().isMacroID())
3823 return false;
3824
3825 QualType VariableTy = VD->getType().getCanonicalType();
3826 SourceLocation Loc = S.getLocForEndOfToken(VD->getEndLoc());
3827 std::string Init = S.getFixItZeroInitializerForType(VariableTy, Loc);
3828 if (!Init.empty()) {
3829 Sequence.AddZeroInitializationStep(Entity.getType());
3830 Sequence.SetZeroInitializationFixit(Init, Loc);
3831 return true;
3832 }
3833 return false;
3834}
3835
3836static void MaybeProduceObjCObject(Sema &S,
3837 InitializationSequence &Sequence,
3838 const InitializedEntity &Entity) {
3839 if (!S.getLangOpts().ObjCAutoRefCount) return;
3840
3841 /// When initializing a parameter, produce the value if it's marked
3842 /// __attribute__((ns_consumed)).
3843 if (Entity.isParameterKind()) {
3844 if (!Entity.isParameterConsumed())
3845 return;
3846
3847 assert(Entity.getType()->isObjCRetainableType() &&((void)0)
3848 "consuming an object of unretainable type?")((void)0);
3849 Sequence.AddProduceObjCObjectStep(Entity.getType());
3850
3851 /// When initializing a return value, if the return type is a
3852 /// retainable type, then returns need to immediately retain the
3853 /// object. If an autorelease is required, it will be done at the
3854 /// last instant.
3855 } else if (Entity.getKind() == InitializedEntity::EK_Result ||
3856 Entity.getKind() == InitializedEntity::EK_StmtExprResult) {
3857 if (!Entity.getType()->isObjCRetainableType())
3858 return;
3859
3860 Sequence.AddProduceObjCObjectStep(Entity.getType());
3861 }
3862}
3863
3864static void TryListInitialization(Sema &S,
3865 const InitializedEntity &Entity,
3866 const InitializationKind &Kind,
3867 InitListExpr *InitList,
3868 InitializationSequence &Sequence,
3869 bool TreatUnavailableAsInvalid);
3870
3871/// When initializing from init list via constructor, handle
3872/// initialization of an object of type std::initializer_list<T>.
3873///
3874/// \return true if we have handled initialization of an object of type
3875/// std::initializer_list<T>, false otherwise.
3876static bool TryInitializerListConstruction(Sema &S,
3877 InitListExpr *List,
3878 QualType DestType,
3879 InitializationSequence &Sequence,
3880 bool TreatUnavailableAsInvalid) {
3881 QualType E;
3882 if (!S.isStdInitializerList(DestType, &E))
3883 return false;
3884
3885 if (!S.isCompleteType(List->getExprLoc(), E)) {
3886 Sequence.setIncompleteTypeFailure(E);
3887 return true;
3888 }
3889
3890 // Try initializing a temporary array from the init list.
3891 QualType ArrayType = S.Context.getConstantArrayType(
3892 E.withConst(),
3893 llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
3894 List->getNumInits()),
3895 nullptr, clang::ArrayType::Normal, 0);
3896 InitializedEntity HiddenArray =
3897 InitializedEntity::InitializeTemporary(ArrayType);
3898 InitializationKind Kind = InitializationKind::CreateDirectList(
3899 List->getExprLoc(), List->getBeginLoc(), List->getEndLoc());
3900 TryListInitialization(S, HiddenArray, Kind, List, Sequence,
3901 TreatUnavailableAsInvalid);
3902 if (Sequence)
3903 Sequence.AddStdInitializerListConstructionStep(DestType);
3904 return true;
3905}
3906
3907/// Determine if the constructor has the signature of a copy or move
3908/// constructor for the type T of the class in which it was found. That is,
3909/// determine if its first parameter is of type T or reference to (possibly
3910/// cv-qualified) T.
3911static bool hasCopyOrMoveCtorParam(ASTContext &Ctx,
3912 const ConstructorInfo &Info) {
3913 if (Info.Constructor->getNumParams() == 0)
38
←
Called C++ object pointer is null
3914 return false;
3915
3916 QualType ParmT =
3917 Info.Constructor->getParamDecl(0)->getType().getNonReferenceType();
3918 QualType ClassT =
3919 Ctx.getRecordType(cast<CXXRecordDecl>(Info.FoundDecl->getDeclContext()));
3920
3921 return Ctx.hasSameUnqualifiedType(ParmT, ClassT);
3922}
3923
3924static OverloadingResult
3925ResolveConstructorOverload(Sema &S, SourceLocation DeclLoc,
3926 MultiExprArg Args,
3927 OverloadCandidateSet &CandidateSet,
3928 QualType DestType,
3929 DeclContext::lookup_result Ctors,
3930 OverloadCandidateSet::iterator &Best,
3931 bool CopyInitializing, bool AllowExplicit,
3932 bool OnlyListConstructors, bool IsListInit,
3933 bool SecondStepOfCopyInit = false) {
3934 CandidateSet.clear(OverloadCandidateSet::CSK_InitByConstructor);
3935 CandidateSet.setDestAS(DestType.getQualifiers().getAddressSpace());
3936
3937 for (NamedDecl *D : Ctors) {
3938 auto Info = getConstructorInfo(D);
3939 if (!Info.Constructor || Info.Constructor->isInvalidDecl())
3940 continue;
3941
3942 if (OnlyListConstructors && !S.isInitListConstructor(Info.Constructor))
3943 continue;
3944
3945 // C++11 [over.best.ics]p4:
3946 // ... and the constructor or user-defined conversion function is a
3947 // candidate by
3948 // - 13.3.1.3, when the argument is the temporary in the second step
3949 // of a class copy-initialization, or
3950 // - 13.3.1.4, 13.3.1.5, or 13.3.1.6 (in all cases), [not handled here]
3951 // - the second phase of 13.3.1.7 when the initializer list has exactly
3952 // one element that is itself an initializer list, and the target is
3953 // the first parameter of a constructor of class X, and the conversion
3954 // is to X or reference to (possibly cv-qualified X),
3955 // user-defined conversion sequences are not considered.
3956 bool SuppressUserConversions =
3957 SecondStepOfCopyInit ||
3958 (IsListInit && Args.size() == 1 && isa<InitListExpr>(Args[0]) &&
3959 hasCopyOrMoveCtorParam(S.Context, Info));
3960
3961 if (Info.ConstructorTmpl)
3962 S.AddTemplateOverloadCandidate(
3963 Info.ConstructorTmpl, Info.FoundDecl,
3964 /*ExplicitArgs*/ nullptr, Args, CandidateSet, SuppressUserConversions,
3965 /*PartialOverloading=*/false, AllowExplicit);
3966 else {
3967 // C++ [over.match.copy]p1:
3968 // - When initializing a temporary to be bound to the first parameter
3969 // of a constructor [for type T] that takes a reference to possibly
3970 // cv-qualified T as its first argument, called with a single
3971 // argument in the context of direct-initialization, explicit
3972 // conversion functions are also considered.
3973 // FIXME: What if a constructor template instantiates to such a signature?
3974 bool AllowExplicitConv = AllowExplicit && !CopyInitializing &&
3975 Args.size() == 1 &&
3976 hasCopyOrMoveCtorParam(S.Context, Info);
3977 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, Args,
3978 CandidateSet, SuppressUserConversions,
3979 /*PartialOverloading=*/false, AllowExplicit,
3980 AllowExplicitConv);
3981 }
3982 }
3983
3984 // FIXME: Work around a bug in C++17 guaranteed copy elision.
3985 //
3986 // When initializing an object of class type T by constructor
3987 // ([over.match.ctor]) or by list-initialization ([over.match.list])
3988 // from a single expression of class type U, conversion functions of
3989 // U that convert to the non-reference type cv T are candidates.
3990 // Explicit conversion functions are only candidates during
3991 // direct-initialization.
3992 //
3993 // Note: SecondStepOfCopyInit is only ever true in this case when
3994 // evaluating whether to produce a C++98 compatibility warning.
3995 if (S.getLangOpts().CPlusPlus17 && Args.size() == 1 &&
3996 !SecondStepOfCopyInit) {
3997 Expr *Initializer = Args[0];
3998 auto *SourceRD = Initializer->getType()->getAsCXXRecordDecl();
3999 if (SourceRD && S.isCompleteType(DeclLoc, Initializer->getType())) {
4000 const auto &Conversions = SourceRD->getVisibleConversionFunctions();
4001 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4002 NamedDecl *D = *I;
4003 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4004 D = D->getUnderlyingDecl();
4005
4006 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
4007 CXXConversionDecl *Conv;
4008 if (ConvTemplate)
4009 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4010 else
4011 Conv = cast<CXXConversionDecl>(D);
4012
4013 if (ConvTemplate)
4014 S.AddTemplateConversionCandidate(
4015 ConvTemplate, I.getPair(), ActingDC, Initializer, DestType,
4016 CandidateSet, AllowExplicit, AllowExplicit,
4017 /*AllowResultConversion*/ false);
4018 else
4019 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Initializer,
4020 DestType, CandidateSet, AllowExplicit,
4021 AllowExplicit,
4022 /*AllowResultConversion*/ false);
4023 }
4024 }
4025 }
4026
4027 // Perform overload resolution and return the result.
4028 return CandidateSet.BestViableFunction(S, DeclLoc, Best);
4029}
4030
4031/// Attempt initialization by constructor (C++ [dcl.init]), which
4032/// enumerates the constructors of the initialized entity and performs overload
4033/// resolution to select the best.
4034/// \param DestType The destination class type.
4035/// \param DestArrayType The destination type, which is either DestType or
4036/// a (possibly multidimensional) array of DestType.
4037/// \param IsListInit Is this list-initialization?
4038/// \param IsInitListCopy Is this non-list-initialization resulting from a
4039/// list-initialization from {x} where x is the same
4040/// type as the entity?
4041static void TryConstructorInitialization(Sema &S,
4042 const InitializedEntity &Entity,
4043 const InitializationKind &Kind,
4044 MultiExprArg Args, QualType DestType,
4045 QualType DestArrayType,
4046 InitializationSequence &Sequence,
4047 bool IsListInit = false,
4048 bool IsInitListCopy = false) {
4049 assert(((!IsListInit && !IsInitListCopy) ||((void)0)
4050 (Args.size() == 1 && isa<InitListExpr>(Args[0]))) &&((void)0)
4051 "IsListInit/IsInitListCopy must come with a single initializer list "((void)0)
4052 "argument.")((void)0);
4053 InitListExpr *ILE =
4054 (IsListInit || IsInitListCopy) ? cast<InitListExpr>(Args[0]) : nullptr;
4055 MultiExprArg UnwrappedArgs =
4056 ILE ? MultiExprArg(ILE->getInits(), ILE->getNumInits()) : Args;
4057
4058 // The type we're constructing needs to be complete.
4059 if (!S.isCompleteType(Kind.getLocation(), DestType)) {
4060 Sequence.setIncompleteTypeFailure(DestType);
4061 return;
4062 }
4063
4064 // C++17 [dcl.init]p17:
4065 // - If the initializer expression is a prvalue and the cv-unqualified
4066 // version of the source type is the same class as the class of the
4067 // destination, the initializer expression is used to initialize the
4068 // destination object.
4069 // Per DR (no number yet), this does not apply when initializing a base
4070 // class or delegating to another constructor from a mem-initializer.
4071 // ObjC++: Lambda captured by the block in the lambda to block conversion
4072 // should avoid copy elision.
4073 if (S.getLangOpts().CPlusPlus17 &&
4074 Entity.getKind() != InitializedEntity::EK_Base &&
4075 Entity.getKind() != InitializedEntity::EK_Delegating &&
4076 Entity.getKind() !=
4077 InitializedEntity::EK_LambdaToBlockConversionBlockElement &&
4078 UnwrappedArgs.size() == 1 && UnwrappedArgs[0]->isPRValue() &&
4079 S.Context.hasSameUnqualifiedType(UnwrappedArgs[0]->getType(), DestType)) {
4080 // Convert qualifications if necessary.
4081 Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
4082 if (ILE)
4083 Sequence.RewrapReferenceInitList(DestType, ILE);
4084 return;
4085 }
4086
4087 const RecordType *DestRecordType = DestType->getAs<RecordType>();
4088 assert(DestRecordType && "Constructor initialization requires record type")((void)0);
4089 CXXRecordDecl *DestRecordDecl
4090 = cast<CXXRecordDecl>(DestRecordType->getDecl());
4091
4092 // Build the candidate set directly in the initialization sequence
4093 // structure, so that it will persist if we fail.
4094 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
4095
4096 // Determine whether we are allowed to call explicit constructors or
4097 // explicit conversion operators.
4098 bool AllowExplicit = Kind.AllowExplicit() || IsListInit;
4099 bool CopyInitialization = Kind.getKind() == InitializationKind::IK_Copy;
4100
4101 // - Otherwise, if T is a class type, constructors are considered. The
4102 // applicable constructors are enumerated, and the best one is chosen
4103 // through overload resolution.
4104 DeclContext::lookup_result Ctors = S.LookupConstructors(DestRecordDecl);
4105
4106 OverloadingResult Result = OR_No_Viable_Function;
4107 OverloadCandidateSet::iterator Best;
4108 bool AsInitializerList = false;
4109
4110 // C++11 [over.match.list]p1, per DR1467:
4111 // When objects of non-aggregate type T are list-initialized, such that
4112 // 8.5.4 [dcl.init.list] specifies that overload resolution is performed
4113 // according to the rules in this section, overload resolution selects
4114 // the constructor in two phases:
4115 //
4116 // - Initially, the candidate functions are the initializer-list
4117 // constructors of the class T and the argument list consists of the
4118 // initializer list as a single argument.
4119 if (IsListInit) {
4120 AsInitializerList = true;
4121
4122 // If the initializer list has no elements and T has a default constructor,
4123 // the first phase is omitted.
4124 if (!(UnwrappedArgs.empty() && S.LookupDefaultConstructor(DestRecordDecl)))
4125 Result = ResolveConstructorOverload(S, Kind.getLocation(), Args,
4126 CandidateSet, DestType, Ctors, Best,
4127 CopyInitialization, AllowExplicit,
4128 /*OnlyListConstructors=*/true,
4129 IsListInit);
4130 }
4131
4132 // C++11 [over.match.list]p1:
4133 // - If no viable initializer-list constructor is found, overload resolution
4134 // is performed again, where the candidate functions are all the
4135 // constructors of the class T and the argument list consists of the
4136 // elements of the initializer list.
4137 if (Result == OR_No_Viable_Function) {
4138 AsInitializerList = false;
4139 Result = ResolveConstructorOverload(S, Kind.getLocation(), UnwrappedArgs,
4140 CandidateSet, DestType, Ctors, Best,
4141 CopyInitialization, AllowExplicit,
4142 /*OnlyListConstructors=*/false,
4143 IsListInit);
4144 }
4145 if (Result) {
4146 Sequence.SetOverloadFailure(
4147 IsListInit ? InitializationSequence::FK_ListConstructorOverloadFailed
4148 : InitializationSequence::FK_ConstructorOverloadFailed,
4149 Result);
4150
4151 if (Result != OR_Deleted)
4152 return;
4153 }
4154
4155 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4156
4157 // In C++17, ResolveConstructorOverload can select a conversion function
4158 // instead of a constructor.
4159 if (auto *CD = dyn_cast<CXXConversionDecl>(Best->Function)) {
4160 // Add the user-defined conversion step that calls the conversion function.
4161 QualType ConvType = CD->getConversionType();
4162 assert(S.Context.hasSameUnqualifiedType(ConvType, DestType) &&((void)0)
4163 "should not have selected this conversion function")((void)0);
4164 Sequence.AddUserConversionStep(CD, Best->FoundDecl, ConvType,
4165 HadMultipleCandidates);
4166 if (!S.Context.hasSameType(ConvType, DestType))
4167 Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
4168 if (IsListInit)
4169 Sequence.RewrapReferenceInitList(Entity.getType(), ILE);
4170 return;
4171 }
4172
4173 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
4174 if (Result != OR_Deleted) {
4175 // C++11 [dcl.init]p6:
4176 // If a program calls for the default initialization of an object
4177 // of a const-qualified type T, T shall be a class type with a
4178 // user-provided default constructor.
4179 // C++ core issue 253 proposal:
4180 // If the implicit default constructor initializes all subobjects, no
4181 // initializer should be required.
4182 // The 253 proposal is for example needed to process libstdc++ headers
4183 // in 5.x.
4184 if (Kind.getKind() == InitializationKind::IK_Default &&
4185 Entity.getType().isConstQualified()) {
4186 if (!CtorDecl->getParent()->allowConstDefaultInit()) {
4187 if (!maybeRecoverWithZeroInitialization(S, Sequence, Entity))
4188 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst);
4189 return;
4190 }
4191 }
4192
4193 // C++11 [over.match.list]p1:
4194 // In copy-list-initialization, if an explicit constructor is chosen, the
4195 // initializer is ill-formed.
4196 if (IsListInit && !Kind.AllowExplicit() && CtorDecl->isExplicit()) {
4197 Sequence.SetFailed(InitializationSequence::FK_ExplicitConstructor);
4198 return;
4199 }
4200 }
4201
4202 // [class.copy.elision]p3:
4203 // In some copy-initialization contexts, a two-stage overload resolution
4204 // is performed.
4205 // If the first overload resolution selects a deleted function, we also
4206 // need the initialization sequence to decide whether to perform the second
4207 // overload resolution.
4208 // For deleted functions in other contexts, there is no need to get the
4209 // initialization sequence.
4210 if (Result == OR_Deleted && Kind.getKind() != InitializationKind::IK_Copy)
4211 return;
4212
4213 // Add the constructor initialization step. Any cv-qualification conversion is
4214 // subsumed by the initialization.
4215 Sequence.AddConstructorInitializationStep(
4216 Best->FoundDecl, CtorDecl, DestArrayType, HadMultipleCandidates,
4217 IsListInit | IsInitListCopy, AsInitializerList);
4218}
4219
4220static bool
4221ResolveOverloadedFunctionForReferenceBinding(Sema &S,
4222 Expr *Initializer,
4223 QualType &SourceType,
4224 QualType &UnqualifiedSourceType,
4225 QualType UnqualifiedTargetType,
4226 InitializationSequence &Sequence) {
4227 if (S.Context.getCanonicalType(UnqualifiedSourceType) ==
4228 S.Context.OverloadTy) {
4229 DeclAccessPair Found;
4230 bool HadMultipleCandidates = false;
4231 if (FunctionDecl *Fn
4232 = S.ResolveAddressOfOverloadedFunction(Initializer,
4233 UnqualifiedTargetType,
4234 false, Found,
4235 &HadMultipleCandidates)) {
4236 Sequence.AddAddressOverloadResolutionStep(Fn, Found,
4237 HadMultipleCandidates);
4238 SourceType = Fn->getType();
4239 UnqualifiedSourceType = SourceType.getUnqualifiedType();
4240 } else if (!UnqualifiedTargetType->isRecordType()) {
4241 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
4242 return true;
4243 }
4244 }
4245 return false;
4246}
4247
4248static void TryReferenceInitializationCore(Sema &S,
4249 const InitializedEntity &Entity,
4250 const InitializationKind &Kind,
4251 Expr *Initializer,
4252 QualType cv1T1, QualType T1,
4253 Qualifiers T1Quals,
4254 QualType cv2T2, QualType T2,
4255 Qualifiers T2Quals,
4256 InitializationSequence &Sequence);
4257
4258static void TryValueInitialization(Sema &S,
4259 const InitializedEntity &Entity,
4260 const InitializationKind &Kind,
4261 InitializationSequence &Sequence,
4262 InitListExpr *InitList = nullptr);
4263
4264/// Attempt list initialization of a reference.
4265static void TryReferenceListInitialization(Sema &S,
4266 const InitializedEntity &Entity,
4267 const InitializationKind &Kind,
4268 InitListExpr *InitList,
4269 InitializationSequence &Sequence,
4270 bool TreatUnavailableAsInvalid) {
4271 // First, catch C++03 where this isn't possible.
4272 if (!S.getLangOpts().CPlusPlus11) {
4273 Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList);
4274 return;
4275 }
4276 // Can't reference initialize a compound literal.
4277 if (Entity.getKind() == InitializedEntity::EK_CompoundLiteralInit) {
4278 Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList);
4279 return;
4280 }
4281
4282 QualType DestType = Entity.getType();
4283 QualType cv1T1 = DestType->castAs<ReferenceType>()->getPointeeType();
4284 Qualifiers T1Quals;
4285 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals);
4286
4287 // Reference initialization via an initializer list works thus:
4288 // If the initializer list consists of a single element that is
4289 // reference-related to the referenced type, bind directly to that element
4290 // (possibly creating temporaries).
4291 // Otherwise, initialize a temporary with the initializer list and
4292 // bind to that.
4293 if (InitList->getNumInits() == 1) {
4294 Expr *Initializer = InitList->getInit(0);
4295 QualType cv2T2 = S.getCompletedType(Initializer);
4296 Qualifiers T2Quals;
4297 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals);
4298
4299 // If this fails, creating a temporary wouldn't work either.
4300 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2,
4301 T1, Sequence))
4302 return;
4303
4304 SourceLocation DeclLoc = Initializer->getBeginLoc();
4305 Sema::ReferenceCompareResult RefRelationship
4306 = S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2);
4307 if (RefRelationship >= Sema::Ref_Related) {
4308 // Try to bind the reference here.
4309 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1,
4310 T1Quals, cv2T2, T2, T2Quals, Sequence);
4311 if (Sequence)
4312 Sequence.RewrapReferenceInitList(cv1T1, InitList);
4313 return;
4314 }
4315
4316 // Update the initializer if we've resolved an overloaded function.
4317 if (Sequence.step_begin() != Sequence.step_end())
4318 Sequence.RewrapReferenceInitList(cv1T1, InitList);
4319 }
4320 // Perform address space compatibility check.
4321 QualType cv1T1IgnoreAS = cv1T1;
4322 if (T1Quals.hasAddressSpace()) {
4323 Qualifiers T2Quals;
4324 (void)S.Context.getUnqualifiedArrayType(InitList->getType(), T2Quals);
4325 if (!T1Quals.isAddressSpaceSupersetOf(T2Quals)) {
4326 Sequence.SetFailed(
4327 InitializationSequence::FK_ReferenceInitDropsQualifiers);
4328 return;
4329 }
4330 // Ignore address space of reference type at this point and perform address
4331 // space conversion after the reference binding step.
4332 cv1T1IgnoreAS =
4333 S.Context.getQualifiedType(T1, T1Quals.withoutAddressSpace());
4334 }
4335 // Not reference-related. Create a temporary and bind to that.
4336 InitializedEntity TempEntity =
4337 InitializedEntity::InitializeTemporary(cv1T1IgnoreAS);
4338
4339 TryListInitialization(S, TempEntity, Kind, InitList, Sequence,
4340 TreatUnavailableAsInvalid);
4341 if (Sequence) {
4342 if (DestType->isRValueReferenceType() ||
4343 (T1Quals.hasConst() && !T1Quals.hasVolatile())) {
4344 Sequence.AddReferenceBindingStep(cv1T1IgnoreAS,
4345 /*BindingTemporary=*/true);
4346 if (T1Quals.hasAddressSpace())
4347 Sequence.AddQualificationConversionStep(
4348 cv1T1, DestType->isRValueReferenceType() ? VK_XValue : VK_LValue);
4349 } else
4350 Sequence.SetFailed(
4351 InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary);
4352 }
4353}
4354
4355/// Attempt list initialization (C++0x [dcl.init.list])
4356static void TryListInitialization(Sema &S,
4357 const InitializedEntity &Entity,
4358 const InitializationKind &Kind,
4359 InitListExpr *InitList,
4360 InitializationSequence &Sequence,
4361 bool TreatUnavailableAsInvalid) {
4362 QualType DestType = Entity.getType();
4363
4364 // C++ doesn't allow scalar initialization with more than one argument.
4365 // But C99 complex numbers are scalars and it makes sense there.
4366 if (S.getLangOpts().CPlusPlus && DestType->isScalarType() &&
4367 !DestType->isAnyComplexType() && InitList->getNumInits() > 1) {
4368 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForScalar);
4369 return;
4370 }
4371 if (DestType->isReferenceType()) {
4372 TryReferenceListInitialization(S, Entity, Kind, InitList, Sequence,
4373 TreatUnavailableAsInvalid);
4374 return;
4375 }
4376
4377 if (DestType->isRecordType() &&
4378 !S.isCompleteType(InitList->getBeginLoc(), DestType)) {
4379 Sequence.setIncompleteTypeFailure(DestType);
4380 return;
4381 }
4382
4383 // C++11 [dcl.init.list]p3, per DR1467:
4384 // - If T is a class type and the initializer list has a single element of
4385 // type cv U, where U is T or a class derived from T, the object is
4386 // initialized from that element (by copy-initialization for
4387 // copy-list-initialization, or by direct-initialization for
4388 // direct-list-initialization).
4389 // - Otherwise, if T is a character array and the initializer list has a
4390 // single element that is an appropriately-typed string literal
4391 // (8.5.2 [dcl.init.string]), initialization is performed as described
4392 // in that section.
4393 // - Otherwise, if T is an aggregate, [...] (continue below).
4394 if (S.getLangOpts().CPlusPlus11 && InitList->getNumInits() == 1) {
4395 if (DestType->isRecordType()) {
4396 QualType InitType = InitList->getInit(0)->getType();
4397 if (S.Context.hasSameUnqualifiedType(InitType, DestType) ||
4398 S.IsDerivedFrom(InitList->getBeginLoc(), InitType, DestType)) {
4399 Expr *InitListAsExpr = InitList;
4400 TryConstructorInitialization(S, Entity, Kind, InitListAsExpr, DestType,
4401 DestType, Sequence,
4402 /*InitListSyntax*/false,
4403 /*IsInitListCopy*/true);
4404 return;
4405 }
4406 }
4407 if (const ArrayType *DestAT = S.Context.getAsArrayType(DestType)) {
4408 Expr *SubInit[1] = {InitList->getInit(0)};
4409 if (!isa<VariableArrayType>(DestAT) &&
4410 IsStringInit(SubInit[0], DestAT, S.Context) == SIF_None) {
4411 InitializationKind SubKind =
4412 Kind.getKind() == InitializationKind::IK_DirectList
4413 ? InitializationKind::CreateDirect(Kind.getLocation(),
4414 InitList->getLBraceLoc(),
4415 InitList->getRBraceLoc())
4416 : Kind;
4417 Sequence.InitializeFrom(S, Entity, SubKind, SubInit,
4418 /*TopLevelOfInitList*/ true,
4419 TreatUnavailableAsInvalid);
4420
4421 // TryStringLiteralInitialization() (in InitializeFrom()) will fail if
4422 // the element is not an appropriately-typed string literal, in which
4423 // case we should proceed as in C++11 (below).
4424 if (Sequence) {
4425 Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
4426 return;
4427 }
4428 }
4429 }
4430 }
4431
4432 // C++11 [dcl.init.list]p3:
4433 // - If T is an aggregate, aggregate initialization is performed.
4434 if ((DestType->isRecordType() && !DestType->isAggregateType()) ||
4435 (S.getLangOpts().CPlusPlus11 &&
4436 S.isStdInitializerList(DestType, nullptr))) {
4437 if (S.getLangOpts().CPlusPlus11) {
4438 // - Otherwise, if the initializer list has no elements and T is a
4439 // class type with a default constructor, the object is
4440 // value-initialized.
4441 if (InitList->getNumInits() == 0) {
4442 CXXRecordDecl *RD = DestType->getAsCXXRecordDecl();
4443 if (S.LookupDefaultConstructor(RD)) {
4444 TryValueInitialization(S, Entity, Kind, Sequence, InitList);
4445 return;
4446 }
4447 }
4448
4449 // - Otherwise, if T is a specialization of std::initializer_list<E>,
4450 // an initializer_list object constructed [...]
4451 if (TryInitializerListConstruction(S, InitList, DestType, Sequence,
4452 TreatUnavailableAsInvalid))
4453 return;
4454
4455 // - Otherwise, if T is a class type, constructors are considered.
4456 Expr *InitListAsExpr = InitList;
4457 TryConstructorInitialization(S, Entity, Kind, InitListAsExpr, DestType,
4458 DestType, Sequence, /*InitListSyntax*/true);
4459 } else
4460 Sequence.SetFailed(InitializationSequence::FK_InitListBadDestinationType);
4461 return;
4462 }
4463
4464 if (S.getLangOpts().CPlusPlus && !DestType->isAggregateType() &&
4465 InitList->getNumInits() == 1) {
4466 Expr *E = InitList->getInit(0);
4467
4468 // - Otherwise, if T is an enumeration with a fixed underlying type,
4469 // the initializer-list has a single element v, and the initialization
4470 // is direct-list-initialization, the object is initialized with the
4471 // value T(v); if a narrowing conversion is required to convert v to
4472 // the underlying type of T, the program is ill-formed.
4473 auto *ET = DestType->getAs<EnumType>();
4474 if (S.getLangOpts().CPlusPlus17 &&
4475 Kind.getKind() == InitializationKind::IK_DirectList &&
4476 ET && ET->getDecl()->isFixed() &&
4477 !S.Context.hasSameUnqualifiedType(E->getType(), DestType) &&
4478 (E->getType()->isIntegralOrEnumerationType() ||
4479 E->getType()->isFloatingType())) {
4480 // There are two ways that T(v) can work when T is an enumeration type.
4481 // If there is either an implicit conversion sequence from v to T or
4482 // a conversion function that can convert from v to T, then we use that.
4483 // Otherwise, if v is of integral, enumeration, or floating-point type,
4484 // it is converted to the enumeration type via its underlying type.
4485 // There is no overlap possible between these two cases (except when the
4486 // source value is already of the destination type), and the first
4487 // case is handled by the general case for single-element lists below.
4488 ImplicitConversionSequence ICS;
4489 ICS.setStandard();
4490 ICS.Standard.setAsIdentityConversion();
4491 if (!E->isPRValue())
4492 ICS.Standard.First = ICK_Lvalue_To_Rvalue;
4493 // If E is of a floating-point type, then the conversion is ill-formed
4494 // due to narrowing, but go through the motions in order to produce the
4495 // right diagnostic.
4496 ICS.Standard.Second = E->getType()->isFloatingType()
4497 ? ICK_Floating_Integral
4498 : ICK_Integral_Conversion;
4499 ICS.Standard.setFromType(E->getType());
4500 ICS.Standard.setToType(0, E->getType());
4501 ICS.Standard.setToType(1, DestType);
4502 ICS.Standard.setToType(2, DestType);
4503 Sequence.AddConversionSequenceStep(ICS, ICS.Standard.getToType(2),
4504 /*TopLevelOfInitList*/true);
4505 Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
4506 return;
4507 }
4508
4509 // - Otherwise, if the initializer list has a single element of type E
4510 // [...references are handled above...], the object or reference is
4511 // initialized from that element (by copy-initialization for
4512 // copy-list-initialization, or by direct-initialization for
4513 // direct-list-initialization); if a narrowing conversion is required
4514 // to convert the element to T, the program is ill-formed.
4515 //
4516 // Per core-24034, this is direct-initialization if we were performing
4517 // direct-list-initialization and copy-initialization otherwise.
4518 // We can't use InitListChecker for this, because it always performs
4519 // copy-initialization. This only matters if we might use an 'explicit'
4520 // conversion operator, or for the special case conversion of nullptr_t to
4521 // bool, so we only need to handle those cases.
4522 //
4523 // FIXME: Why not do this in all cases?
4524 Expr *Init = InitList->getInit(0);
4525 if (Init->getType()->isRecordType() ||
4526 (Init->getType()->isNullPtrType() && DestType->isBooleanType())) {
4527 InitializationKind SubKind =
4528 Kind.getKind() == InitializationKind::IK_DirectList
4529 ? InitializationKind::CreateDirect(Kind.getLocation(),
4530 InitList->getLBraceLoc(),
4531 InitList->getRBraceLoc())
4532 : Kind;
4533 Expr *SubInit[1] = { Init };
4534 Sequence.InitializeFrom(S, Entity, SubKind, SubInit,
4535 /*TopLevelOfInitList*/true,
4536 TreatUnavailableAsInvalid);
4537 if (Sequence)
4538 Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
4539 return;
4540 }
4541 }
4542
4543 InitListChecker CheckInitList(S, Entity, InitList,
4544 DestType, /*VerifyOnly=*/true, TreatUnavailableAsInvalid);
4545 if (CheckInitList.HadError()) {
4546 Sequence.SetFailed(InitializationSequence::FK_ListInitializationFailed);
4547 return;
4548 }
4549
4550 // Add the list initialization step with the built init list.
4551 Sequence.AddListInitializationStep(DestType);
4552}
4553
4554/// Try a reference initialization that involves calling a conversion
4555/// function.
4556static OverloadingResult TryRefInitWithConversionFunction(
4557 Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind,
4558 Expr *Initializer, bool AllowRValues, bool IsLValueRef,
4559 InitializationSequence &Sequence) {
4560 QualType DestType = Entity.getType();
4561 QualType cv1T1 = DestType->castAs<ReferenceType>()->getPointeeType();
4562 QualType T1 = cv1T1.getUnqualifiedType();
4563 QualType cv2T2 = Initializer->getType();
4564 QualType T2 = cv2T2.getUnqualifiedType();
4565
4566 assert(!S.CompareReferenceRelationship(Initializer->getBeginLoc(), T1, T2) &&((void)0)
4567 "Must have incompatible references when binding via conversion")((void)0);
4568
4569 // Build the candidate set directly in the initialization sequence
4570 // structure, so that it will persist if we fail.
4571 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
4572 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
4573
4574 // Determine whether we are allowed to call explicit conversion operators.
4575 // Note that none of [over.match.copy], [over.match.conv], nor
4576 // [over.match.ref] permit an explicit constructor to be chosen when
4577 // initializing a reference, not even for direct-initialization.
4578 bool AllowExplicitCtors = false;
4579 bool AllowExplicitConvs = Kind.allowExplicitConversionFunctionsInRefBinding();
4580
4581 const RecordType *T1RecordType = nullptr;
4582 if (AllowRValues && (T1RecordType = T1->getAs<RecordType>()) &&
4583 S.isCompleteType(Kind.getLocation(), T1)) {
4584 // The type we're converting to is a class type. Enumerate its constructors
4585 // to see if there is a suitable conversion.
4586 CXXRecordDecl *T1RecordDecl = cast<CXXRecordDecl>(T1RecordType->getDecl());
4587
4588 for (NamedDecl *D : S.LookupConstructors(T1RecordDecl)) {
4589 auto Info = getConstructorInfo(D);
4590 if (!Info.Constructor)
4591 continue;
4592
4593 if (!Info.Constructor->isInvalidDecl() &&
4594 Info.Constructor->isConvertingConstructor(/*AllowExplicit*/true)) {
4595 if (Info.ConstructorTmpl)
4596 S.AddTemplateOverloadCandidate(
4597 Info.ConstructorTmpl, Info.FoundDecl,
4598 /*ExplicitArgs*/ nullptr, Initializer, CandidateSet,
4599 /*SuppressUserConversions=*/true,
4600 /*PartialOverloading*/ false, AllowExplicitCtors);
4601 else
4602 S.AddOverloadCandidate(
4603 Info.Constructor, Info.FoundDecl, Initializer, CandidateSet,
4604 /*SuppressUserConversions=*/true,
4605 /*PartialOverloading*/ false, AllowExplicitCtors);
4606 }
4607 }
4608 }
4609 if (T1RecordType && T1RecordType->getDecl()->isInvalidDecl())
4610 return OR_No_Viable_Function;
4611
4612 const RecordType *T2RecordType = nullptr;
4613 if ((T2RecordType = T2->getAs<RecordType>()) &&
4614 S.isCompleteType(Kind.getLocation(), T2)) {
4615 // The type we're converting from is a class type, enumerate its conversion
4616 // functions.
4617 CXXRecordDecl *T2RecordDecl = cast<CXXRecordDecl>(T2RecordType->getDecl());
4618
4619 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4620 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4621 NamedDecl *D = *I;
4622 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4623 if (isa<UsingShadowDecl>(D))
4624 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4625
4626 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
4627 CXXConversionDecl *Conv;
4628 if (ConvTemplate)
4629 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4630 else
4631 Conv = cast<CXXConversionDecl>(D);
4632
4633 // If the conversion function doesn't return a reference type,
4634 // it can't be considered for this conversion unless we're allowed to
4635 // consider rvalues.
4636 // FIXME: Do we need to make sure that we only consider conversion
4637 // candidates with reference-compatible results? That might be needed to
4638 // break recursion.
4639 if ((AllowRValues ||
4640 Conv->getConversionType()->isLValueReferenceType())) {
4641 if (ConvTemplate)
4642 S.AddTemplateConversionCandidate(
4643 ConvTemplate, I.getPair(), ActingDC, Initializer, DestType,
4644 CandidateSet,
4645 /*AllowObjCConversionOnExplicit=*/false, AllowExplicitConvs);
4646 else
4647 S.AddConversionCandidate(
4648 Conv, I.getPair(), ActingDC, Initializer, DestType, CandidateSet,
4649 /*AllowObjCConversionOnExplicit=*/false, AllowExplicitConvs);
4650 }
4651 }
4652 }
4653 if (T2RecordType && T2RecordType->getDecl()->isInvalidDecl())
4654 return OR_No_Viable_Function;
4655
4656 SourceLocation DeclLoc = Initializer->getBeginLoc();
4657
4658 // Perform overload resolution. If it fails, return the failed result.
4659 OverloadCandidateSet::iterator Best;
4660 if (OverloadingResult Result
4661 = CandidateSet.BestViableFunction(S, DeclLoc, Best))
4662 return Result;
4663
4664 FunctionDecl *Function = Best->Function;
4665 // This is the overload that will be used for this initialization step if we
4666 // use this initialization. Mark it as referenced.
4667 Function->setReferenced();
4668
4669 // Compute the returned type and value kind of the conversion.
4670 QualType cv3T3;
4671 if (isa<CXXConversionDecl>(Function))
4672 cv3T3 = Function->getReturnType();
4673 else
4674 cv3T3 = T1;
4675
4676 ExprValueKind VK = VK_PRValue;
4677 if (cv3T3->isLValueReferenceType())
4678 VK = VK_LValue;
4679 else if (const auto *RRef = cv3T3->getAs<RValueReferenceType>())
4680 VK = RRef->getPointeeType()->isFunctionType() ? VK_LValue : VK_XValue;
4681 cv3T3 = cv3T3.getNonLValueExprType(S.Context);
4682
4683 // Add the user-defined conversion step.
4684 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4685 Sequence.AddUserConversionStep(Function, Best->FoundDecl, cv3T3,
4686 HadMultipleCandidates);
4687
4688 // Determine whether we'll need to perform derived-to-base adjustments or
4689 // other conversions.
4690 Sema::ReferenceConversions RefConv;
4691 Sema::ReferenceCompareResult NewRefRelationship =
4692 S.CompareReferenceRelationship(DeclLoc, T1, cv3T3, &RefConv);
4693
4694 // Add the final conversion sequence, if necessary.
4695 if (NewRefRelationship == Sema::Ref_Incompatible) {
4696 assert(!isa<CXXConstructorDecl>(Function) &&((void)0)
4697 "should not have conversion after constructor")((void)0);
4698
4699 ImplicitConversionSequence ICS;
4700 ICS.setStandard();
4701 ICS.Standard = Best->FinalConversion;
4702 Sequence.AddConversionSequenceStep(ICS, ICS.Standard.getToType(2));
4703
4704 // Every implicit conversion results in a prvalue, except for a glvalue
4705 // derived-to-base conversion, which we handle below.
4706 cv3T3 = ICS.Standard.getToType(2);
4707 VK = VK_PRValue;
4708 }
4709
4710 // If the converted initializer is a prvalue, its type T4 is adjusted to
4711 // type "cv1 T4" and the temporary materialization conversion is applied.
4712 //
4713 // We adjust the cv-qualifications to match the reference regardless of
4714 // whether we have a prvalue so that the AST records the change. In this
4715 // case, T4 is "cv3 T3".
4716 QualType cv1T4 = S.Context.getQualifiedType(cv3T3, cv1T1.getQualifiers());
4717 if (cv1T4.getQualifiers() != cv3T3.getQualifiers())
4718 Sequence.AddQualificationConversionStep(cv1T4, VK);
4719 Sequence.AddReferenceBindingStep(cv1T4, VK == VK_PRValue);
4720 VK = IsLValueRef ? VK_LValue : VK_XValue;
4721
4722 if (RefConv & Sema::ReferenceConversions::DerivedToBase)
4723 Sequence.AddDerivedToBaseCastStep(cv1T1, VK);
4724 else if (RefConv & Sema::ReferenceConversions::ObjC)
4725 Sequence.AddObjCObjectConversionStep(cv1T1);
4726 else if (RefConv & Sema::ReferenceConversions::Function)
4727 Sequence.AddFunctionReferenceConversionStep(cv1T1);
4728 else if (RefConv & Sema::ReferenceConversions::Qualification) {
4729 if (!S.Context.hasSameType(cv1T4, cv1T1))
4730 Sequence.AddQualificationConversionStep(cv1T1, VK);
4731 }
4732
4733 return OR_Success;
4734}
4735
4736static void CheckCXX98CompatAccessibleCopy(Sema &S,
4737 const InitializedEntity &Entity,
4738 Expr *CurInitExpr);
4739
4740/// Attempt reference initialization (C++0x [dcl.init.ref])
4741static void TryReferenceInitialization(Sema &S,
4742 const InitializedEntity &Entity,
4743 const InitializationKind &Kind,
4744 Expr *Initializer,
4745 InitializationSequence &Sequence) {
4746 QualType DestType = Entity.getType();
4747 QualType cv1T1 = DestType->castAs<ReferenceType>()->getPointeeType();
4748 Qualifiers T1Quals;
4749 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals);
4750 QualType cv2T2 = S.getCompletedType(Initializer);
4751 Qualifiers T2Quals;
4752 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals);
4753
4754 // If the initializer is the address of an overloaded function, try
4755 // to resolve the overloaded function. If all goes well, T2 is the
4756 // type of the resulting function.
4757 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2,
4758 T1, Sequence))
4759 return;
4760
4761 // Delegate everything else to a subfunction.
4762 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1,
4763 T1Quals, cv2T2, T2, T2Quals, Sequence);
4764}
4765
4766/// Determine whether an expression is a non-referenceable glvalue (one to
4767/// which a reference can never bind). Attempting to bind a reference to
4768/// such a glvalue will always create a temporary.
4769static bool isNonReferenceableGLValue(Expr *E) {
4770 return E->refersToBitField() || E->refersToVectorElement() ||
4771 E->refersToMatrixElement();
4772}
4773
4774/// Reference initialization without resolving overloaded functions.
4775///
4776/// We also can get here in C if we call a builtin which is declared as
4777/// a function with a parameter of reference type (such as __builtin_va_end()).
4778static void TryReferenceInitializationCore(Sema &S,
4779 const InitializedEntity &Entity,
4780 const InitializationKind &Kind,
4781 Expr *Initializer,
4782 QualType cv1T1, QualType T1,
4783 Qualifiers T1Quals,
4784 QualType cv2T2, QualType T2,
4785 Qualifiers T2Quals,
4786 InitializationSequence &Sequence) {
4787 QualType DestType = Entity.getType();
4788 SourceLocation DeclLoc = Initializer->getBeginLoc();
4789
4790 // Compute some basic properties of the types and the initializer.
4791 bool isLValueRef = DestType->isLValueReferenceType();
4792 bool isRValueRef = !isLValueRef;
4793 Expr::Classification InitCategory = Initializer->Classify(S.Context);
4794
4795 Sema::ReferenceConversions RefConv;
4796 Sema::ReferenceCompareResult RefRelationship =
4797 S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, &RefConv);
4798
4799 // C++0x [dcl.init.ref]p5:
4800 // A reference to type "cv1 T1" is initialized by an expression of type
4801 // "cv2 T2" as follows:
4802 //
4803 // - If the reference is an lvalue reference and the initializer
4804 // expression
4805 // Note the analogous bullet points for rvalue refs to functions. Because
4806 // there are no function rvalues in C++, rvalue refs to functions are treated
4807 // like lvalue refs.
4808 OverloadingResult ConvOvlResult = OR_Success;
4809 bool T1Function = T1->isFunctionType();
4810 if (isLValueRef || T1Function) {
4811 if (InitCategory.isLValue() && !isNonReferenceableGLValue(Initializer) &&
4812 (RefRelationship == Sema::Ref_Compatible ||
4813 (Kind.isCStyleOrFunctionalCast() &&
4814 RefRelationship == Sema::Ref_Related))) {
4815 // - is an lvalue (but is not a bit-field), and "cv1 T1" is
4816 // reference-compatible with "cv2 T2," or
4817 if (RefConv & (Sema::ReferenceConversions::DerivedToBase |
4818 Sema::ReferenceConversions::ObjC)) {
4819 // If we're converting the pointee, add any qualifiers first;
4820 // these qualifiers must all be top-level, so just convert to "cv1 T2".
4821 if (RefConv & (Sema::ReferenceConversions::Qualification))
4822 Sequence.AddQualificationConversionStep(
4823 S.Context.getQualifiedType(T2, T1Quals),
4824 Initializer->getValueKind());
4825 if (RefConv & Sema::ReferenceConversions::DerivedToBase)
4826 Sequence.AddDerivedToBaseCastStep(cv1T1, VK_LValue);
4827 else
4828 Sequence.AddObjCObjectConversionStep(cv1T1);
4829 } else if (RefConv & Sema::ReferenceConversions::Qualification) {
4830 // Perform a (possibly multi-level) qualification conversion.
4831 Sequence.AddQualificationConversionStep(cv1T1,
4832 Initializer->getValueKind());
4833 } else if (RefConv & Sema::ReferenceConversions::Function) {
4834 Sequence.AddFunctionReferenceConversionStep(cv1T1);
4835 }
4836
4837 // We only create a temporary here when binding a reference to a
4838 // bit-field or vector element. Those cases are't supposed to be
4839 // handled by this bullet, but the outcome is the same either way.
4840 Sequence.AddReferenceBindingStep(cv1T1, false);
4841 return;
4842 }
4843
4844 // - has a class type (i.e., T2 is a class type), where T1 is not
4845 // reference-related to T2, and can be implicitly converted to an
4846 // lvalue of type "cv3 T3," where "cv1 T1" is reference-compatible
4847 // with "cv3 T3" (this conversion is selected by enumerating the
4848 // applicable conversion functions (13.3.1.6) and choosing the best
4849 // one through overload resolution (13.3)),
4850 // If we have an rvalue ref to function type here, the rhs must be
4851 // an rvalue. DR1287 removed the "implicitly" here.
4852 if (RefRelationship == Sema::Ref_Incompatible && T2->isRecordType() &&
4853 (isLValueRef || InitCategory.isRValue())) {
4854 if (S.getLangOpts().CPlusPlus) {
4855 // Try conversion functions only for C++.
4856 ConvOvlResult = TryRefInitWithConversionFunction(
4857 S, Entity, Kind, Initializer, /*AllowRValues*/ isRValueRef,
4858 /*IsLValueRef*/ isLValueRef, Sequence);
4859 if (ConvOvlResult == OR_Success)
4860 return;
4861 if (ConvOvlResult != OR_No_Viable_Function)
4862 Sequence.SetOverloadFailure(
4863 InitializationSequence::FK_ReferenceInitOverloadFailed,
4864 ConvOvlResult);
4865 } else {
4866 ConvOvlResult = OR_No_Viable_Function;
4867 }
4868 }
4869 }
4870
4871 // - Otherwise, the reference shall be an lvalue reference to a
4872 // non-volatile const type (i.e., cv1 shall be const), or the reference
4873 // shall be an rvalue reference.
4874 // For address spaces, we interpret this to mean that an addr space
4875 // of a reference "cv1 T1" is a superset of addr space of "cv2 T2".
4876 if (isLValueRef && !(T1Quals.hasConst() && !T1Quals.hasVolatile() &&
4877 T1Quals.isAddressSpaceSupersetOf(T2Quals))) {
4878 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy)
4879 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
4880 else if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
4881 Sequence.SetOverloadFailure(
4882 InitializationSequence::FK_ReferenceInitOverloadFailed,
4883 ConvOvlResult);
4884 else if (!InitCategory.isLValue())
4885 Sequence.SetFailed(
4886 T1Quals.isAddressSpaceSupersetOf(T2Quals)
4887 ? InitializationSequence::
4888 FK_NonConstLValueReferenceBindingToTemporary
4889 : InitializationSequence::FK_ReferenceInitDropsQualifiers);
4890 else {
4891 InitializationSequence::FailureKind FK;
4892 switch (RefRelationship) {
4893 case Sema::Ref_Compatible:
4894 if (Initializer->refersToBitField())
4895 FK = InitializationSequence::
4896 FK_NonConstLValueReferenceBindingToBitfield;
4897 else if (Initializer->refersToVectorElement())
4898 FK = InitializationSequence::
4899 FK_NonConstLValueReferenceBindingToVectorElement;
4900 else if (Initializer->refersToMatrixElement())
4901 FK = InitializationSequence::
4902 FK_NonConstLValueReferenceBindingToMatrixElement;
4903 else
4904 llvm_unreachable("unexpected kind of compatible initializer")__builtin_unreachable();
4905 break;
4906 case Sema::Ref_Related:
4907 FK = InitializationSequence::FK_ReferenceInitDropsQualifiers;
4908 break;
4909 case Sema::Ref_Incompatible:
4910 FK = InitializationSequence::
4911 FK_NonConstLValueReferenceBindingToUnrelated;
4912 break;
4913 }
4914 Sequence.SetFailed(FK);
4915 }
4916 return;
4917 }
4918
4919 // - If the initializer expression
4920 // - is an
4921 // [<=14] xvalue (but not a bit-field), class prvalue, array prvalue, or
4922 // [1z] rvalue (but not a bit-field) or
4923 // function lvalue and "cv1 T1" is reference-compatible with "cv2 T2"
4924 //
4925 // Note: functions are handled above and below rather than here...
4926 if (!T1Function &&
4927 (RefRelationship == Sema::Ref_Compatible ||
4928 (Kind.isCStyleOrFunctionalCast() &&
4929 RefRelationship == Sema::Ref_Related)) &&
4930 ((InitCategory.isXValue() && !isNonReferenceableGLValue(Initializer)) ||
4931 (InitCategory.isPRValue() &&
4932 (S.getLangOpts().CPlusPlus17 || T2->isRecordType() ||
4933 T2->isArrayType())))) {
4934 ExprValueKind ValueKind = InitCategory.isXValue() ? VK_XValue : VK_PRValue;
4935 if (InitCategory.isPRValue() && T2->isRecordType()) {
4936 // The corresponding bullet in C++03 [dcl.init.ref]p5 gives the
4937 // compiler the freedom to perform a copy here or bind to the
4938 // object, while C++0x requires that we bind directly to the
4939 // object. Hence, we always bind to the object without making an
4940 // extra copy. However, in C++03 requires that we check for the
4941 // presence of a suitable copy constructor:
4942 //
4943 // The constructor that would be used to make the copy shall
4944 // be callable whether or not the copy is actually done.
4945 if (!S.getLangOpts().CPlusPlus11 && !S.getLangOpts().MicrosoftExt)
4946 Sequence.AddExtraneousCopyToTemporary(cv2T2);
4947 else if (S.getLangOpts().CPlusPlus11)
4948 CheckCXX98CompatAccessibleCopy(S, Entity, Initializer);
4949 }
4950
4951 // C++1z [dcl.init.ref]/5.2.1.2:
4952 // If the converted initializer is a prvalue, its type T4 is adjusted
4953 // to type "cv1 T4" and the temporary materialization conversion is
4954 // applied.
4955 // Postpone address space conversions to after the temporary materialization
4956 // conversion to allow creating temporaries in the alloca address space.
4957 auto T1QualsIgnoreAS = T1Quals;
4958 auto T2QualsIgnoreAS = T2Quals;
4959 if (T1Quals.getAddressSpace() != T2Quals.getAddressSpace()) {
4960 T1QualsIgnoreAS.removeAddressSpace();
4961 T2QualsIgnoreAS.removeAddressSpace();
4962 }
4963 QualType cv1T4 = S.Context.getQualifiedType(cv2T2, T1QualsIgnoreAS);
4964 if (T1QualsIgnoreAS != T2QualsIgnoreAS)
4965 Sequence.AddQualificationConversionStep(cv1T4, ValueKind);
4966 Sequence.AddReferenceBindingStep(cv1T4, ValueKind == VK_PRValue);
4967 ValueKind = isLValueRef ? VK_LValue : VK_XValue;
4968 // Add addr space conversion if required.
4969 if (T1Quals.getAddressSpace() != T2Quals.getAddressSpace()) {
4970 auto T4Quals = cv1T4.getQualifiers();
4971 T4Quals.addAddressSpace(T1Quals.getAddressSpace());
4972 QualType cv1T4WithAS = S.Context.getQualifiedType(T2, T4Quals);
4973 Sequence.AddQualificationConversionStep(cv1T4WithAS, ValueKind);
4974 cv1T4 = cv1T4WithAS;
4975 }
4976
4977 // In any case, the reference is bound to the resulting glvalue (or to
4978 // an appropriate base class subobject).
4979 if (RefConv & Sema::ReferenceConversions::DerivedToBase)
4980 Sequence.AddDerivedToBaseCastStep(cv1T1, ValueKind);
4981 else if (RefConv & Sema::ReferenceConversions::ObjC)
4982 Sequence.AddObjCObjectConversionStep(cv1T1);
4983 else if (RefConv & Sema::ReferenceConversions::Qualification) {
4984 if (!S.Context.hasSameType(cv1T4, cv1T1))
4985 Sequence.AddQualificationConversionStep(cv1T1, ValueKind);
4986 }
4987 return;
4988 }
4989
4990 // - has a class type (i.e., T2 is a class type), where T1 is not
4991 // reference-related to T2, and can be implicitly converted to an
4992 // xvalue, class prvalue, or function lvalue of type "cv3 T3",
4993 // where "cv1 T1" is reference-compatible with "cv3 T3",
4994 //
4995 // DR1287 removes the "implicitly" here.
4996 if (T2->isRecordType()) {
4997 if (RefRelationship == Sema::Ref_Incompatible) {
4998 ConvOvlResult = TryRefInitWithConversionFunction(
4999 S, Entity, Kind, Initializer, /*AllowRValues*/ true,
5000 /*IsLValueRef*/ isLValueRef, Sequence);
5001 if (ConvOvlResult)
5002 Sequence.SetOverloadFailure(
5003 InitializationSequence::FK_ReferenceInitOverloadFailed,
5004 ConvOvlResult);
5005
5006 return;
5007 }
5008
5009 if (RefRelationship == Sema::Ref_Compatible &&
5010 isRValueRef && InitCategory.isLValue()) {
5011 Sequence.SetFailed(
5012 InitializationSequence::FK_RValueReferenceBindingToLValue);
5013 return;
5014 }
5015
5016 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
5017 return;
5018 }
5019
5020 // - Otherwise, a temporary of type "cv1 T1" is created and initialized
5021 // from the initializer expression using the rules for a non-reference
5022 // copy-initialization (8.5). The reference is then bound to the
5023 // temporary. [...]
5024
5025 // Ignore address space of reference type at this point and perform address
5026 // space conversion after the reference binding step.
5027 QualType cv1T1IgnoreAS =
5028 T1Quals.hasAddressSpace()
5029 ? S.Context.getQualifiedType(T1, T1Quals.withoutAddressSpace())
5030 : cv1T1;
5031
5032 InitializedEntity TempEntity =
5033 InitializedEntity::InitializeTemporary(cv1T1IgnoreAS);
5034
5035 // FIXME: Why do we use an implicit conversion here rather than trying
5036 // copy-initialization?
5037 ImplicitConversionSequence ICS
5038 = S.TryImplicitConversion(Initializer, TempEntity.getType(),
5039 /*SuppressUserConversions=*/false,
5040 Sema::AllowedExplicit::None,
5041 /*FIXME:InOverloadResolution=*/false,
5042 /*CStyle=*/Kind.isCStyleOrFunctionalCast(),
5043 /*AllowObjCWritebackConversion=*/false);
5044
5045 if (ICS.isBad()) {
5046 // FIXME: Use the conversion function set stored in ICS to turn
5047 // this into an overloading ambiguity diagnostic. However, we need
5048 // to keep that set as an OverloadCandidateSet rather than as some
5049 // other kind of set.
5050 if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
5051 Sequence.SetOverloadFailure(
5052 InitializationSequence::FK_ReferenceInitOverloadFailed,
5053 ConvOvlResult);
5054 else if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy)
5055 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
5056 else
5057 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitFailed);
5058 return;
5059 } else {
5060 Sequence.AddConversionSequenceStep(ICS, TempEntity.getType());
5061 }
5062
5063 // [...] If T1 is reference-related to T2, cv1 must be the
5064 // same cv-qualification as, or greater cv-qualification
5065 // than, cv2; otherwise, the program is ill-formed.
5066 unsigned T1CVRQuals = T1Quals.getCVRQualifiers();
5067 unsigned T2CVRQuals = T2Quals.getCVRQualifiers();
5068 if (RefRelationship == Sema::Ref_Related &&
5069 ((T1CVRQuals | T2CVRQuals) != T1CVRQuals ||
5070 !T1Quals.isAddressSpaceSupersetOf(T2Quals))) {
5071 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
5072 return;
5073 }
5074
5075 // [...] If T1 is reference-related to T2 and the reference is an rvalue
5076 // reference, the initializer expression shall not be an lvalue.
5077 if (RefRelationship >= Sema::Ref_Related && !isLValueRef &&
5078 InitCategory.isLValue()) {
5079 Sequence.SetFailed(
5080 InitializationSequence::FK_RValueReferenceBindingToLValue);
5081 return;
5082 }
5083
5084 Sequence.AddReferenceBindingStep(cv1T1IgnoreAS, /*BindingTemporary=*/true);
5085
5086 if (T1Quals.hasAddressSpace()) {
5087 if (!Qualifiers::isAddressSpaceSupersetOf(T1Quals.getAddressSpace(),
5088 LangAS::Default)) {
5089 Sequence.SetFailed(
5090 InitializationSequence::FK_ReferenceAddrspaceMismatchTemporary);
5091 return;
5092 }
5093 Sequence.AddQualificationConversionStep(cv1T1, isLValueRef ? VK_LValue
5094 : VK_XValue);
5095 }
5096}
5097
5098/// Attempt character array initialization from a string literal
5099/// (C++ [dcl.init.string], C99 6.7.8).
5100static void TryStringLiteralInitialization(Sema &S,
5101 const InitializedEntity &Entity,
5102 const InitializationKind &Kind,
5103 Expr *Initializer,
5104 InitializationSequence &Sequence) {
5105 Sequence.AddStringInitStep(Entity.getType());
5106}
5107
5108/// Attempt value initialization (C++ [dcl.init]p7).
5109static void TryValueInitialization(Sema &S,
5110 const InitializedEntity &Entity,
5111 const InitializationKind &Kind,
5112 InitializationSequence &Sequence,
5113 InitListExpr *InitList) {
5114 assert((!InitList || InitList->getNumInits() == 0) &&((void)0)
5115 "Shouldn't use value-init for non-empty init lists")((void)0);
5116
5117 // C++98 [dcl.init]p5, C++11 [dcl.init]p7:
5118 //
5119 // To value-initialize an object of type T means:
5120 QualType T = Entity.getType();
5121
5122 // -- if T is an array type, then each element is value-initialized;
5123 T = S.Context.getBaseElementType(T);
5124
5125 if (const RecordType *RT = T->getAs<RecordType>()) {
5126 if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
5127 bool NeedZeroInitialization = true;
5128 // C++98:
5129 // -- if T is a class type (clause 9) with a user-declared constructor
5130 // (12.1), then the default constructor for T is called (and the
5131 // initialization is ill-formed if T has no accessible default
5132 // constructor);
5133 // C++11:
5134 // -- if T is a class type (clause 9) with either no default constructor
5135 // (12.1 [class.ctor]) or a default constructor that is user-provided
5136 // or deleted, then the object is default-initialized;
5137 //
5138 // Note that the C++11 rule is the same as the C++98 rule if there are no
5139 // defaulted or deleted constructors, so we just use it unconditionally.
5140 CXXConstructorDecl *CD = S.LookupDefaultConstructor(ClassDecl);
5141 if (!CD || !CD->getCanonicalDecl()->isDefaulted() || CD->isDeleted())
5142 NeedZeroInitialization = false;
5143
5144 // -- if T is a (possibly cv-qualified) non-union class type without a
5145 // user-provided or deleted default constructor, then the object is
5146 // zero-initialized and, if T has a non-trivial default constructor,
5147 // default-initialized;
5148 // The 'non-union' here was removed by DR1502. The 'non-trivial default
5149 // constructor' part was removed by DR1507.
5150 if (NeedZeroInitialization)
5151 Sequence.AddZeroInitializationStep(Entity.getType());
5152
5153 // C++03:
5154 // -- if T is a non-union class type without a user-declared constructor,
5155 // then every non-static data member and base class component of T is
5156 // value-initialized;
5157 // [...] A program that calls for [...] value-initialization of an
5158 // entity of reference type is ill-formed.
5159 //
5160 // C++11 doesn't need this handling, because value-initialization does not
5161 // occur recursively there, and the implicit default constructor is
5162 // defined as deleted in the problematic cases.
5163 if (!S.getLangOpts().CPlusPlus11 &&
5164 ClassDecl->hasUninitializedReferenceMember()) {
5165 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForReference);
5166 return;
5167 }
5168
5169 // If this is list-value-initialization, pass the empty init list on when
5170 // building the constructor call. This affects the semantics of a few
5171 // things (such as whether an explicit default constructor can be called).
5172 Expr *InitListAsExpr = InitList;
5173 MultiExprArg Args(&InitListAsExpr, InitList ? 1 : 0);
5174 bool InitListSyntax = InitList;
5175
5176 // FIXME: Instead of creating a CXXConstructExpr of array type here,
5177 // wrap a class-typed CXXConstructExpr in an ArrayInitLoopExpr.
5178 return TryConstructorInitialization(
5179 S, Entity, Kind, Args, T, Entity.getType(), Sequence, InitListSyntax);
5180 }
5181 }
5182
5183 Sequence.AddZeroInitializationStep(Entity.getType());
5184}
5185
5186/// Attempt default initialization (C++ [dcl.init]p6).
5187static void TryDefaultInitialization(Sema &S,
5188 const InitializedEntity &Entity,
5189 const InitializationKind &Kind,
5190 InitializationSequence &Sequence) {
5191 assert(Kind.getKind() == InitializationKind::IK_Default)((void)0);
5192
5193 // C++ [dcl.init]p6:
5194 // To default-initialize an object of type T means:
5195 // - if T is an array type, each element is default-initialized;
5196 QualType DestType = S.Context.getBaseElementType(Entity.getType());
5197
5198 // - if T is a (possibly cv-qualified) class type (Clause 9), the default
5199 // constructor for T is called (and the initialization is ill-formed if
5200 // T has no accessible default constructor);
5201 if (DestType->isRecordType() && S.getLangOpts().CPlusPlus) {
5202 TryConstructorInitialization(S, Entity, Kind, None, DestType,
5203 Entity.getType(), Sequence);
5204 return;
5205 }
5206
5207 // - otherwise, no initialization is performed.
5208
5209 // If a program calls for the default initialization of an object of
5210 // a const-qualified type T, T shall be a class type with a user-provided
5211 // default constructor.
5212 if (DestType.isConstQualified() && S.getLangOpts().CPlusPlus) {
5213 if (!maybeRecoverWithZeroInitialization(S, Sequence, Entity))
5214 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst);
5215 return;
5216 }
5217
5218 // If the destination type has a lifetime property, zero-initialize it.
5219 if (DestType.getQualifiers().hasObjCLifetime()) {
5220 Sequence.AddZeroInitializationStep(Entity.getType());
5221 return;
5222 }
5223}
5224
5225/// Attempt a user-defined conversion between two types (C++ [dcl.init]),
5226/// which enumerates all conversion functions and performs overload resolution
5227/// to select the best.
5228static void TryUserDefinedConversion(Sema &S,
5229 QualType DestType,
5230 const InitializationKind &Kind,
5231 Expr *Initializer,
5232 InitializationSequence &Sequence,
5233 bool TopLevelOfInitList) {
5234 assert(!DestType->isReferenceType() && "References are handled elsewhere")((void)0);
5235 QualType SourceType = Initializer->getType();
5236 assert((DestType->isRecordType() || SourceType->isRecordType()) &&((void)0)
5237 "Must have a class type to perform a user-defined conversion")((void)0);
5238
5239 // Build the candidate set directly in the initialization sequence
5240 // structure, so that it will persist if we fail.
5241 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
5242 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
5243 CandidateSet.setDestAS(DestType.getQualifiers().getAddressSpace());
5244
5245 // Determine whether we are allowed to call explicit constructors or
5246 // explicit conversion operators.
5247 bool AllowExplicit = Kind.AllowExplicit();
5248
5249 if (const RecordType *DestRecordType = DestType->getAs<RecordType>()) {
5250 // The type we're converting to is a class type. Enumerate its constructors
5251 // to see if there is a suitable conversion.
5252 CXXRecordDecl *DestRecordDecl
5253 = cast<CXXRecordDecl>(DestRecordType->getDecl());
5254
5255 // Try to complete the type we're converting to.
5256 if (S.isCompleteType(Kind.getLocation(), DestType)) {
5257 for (NamedDecl *D : S.LookupConstructors(DestRecordDecl)) {
5258 auto Info = getConstructorInfo(D);
5259 if (!Info.Constructor)
5260 continue;
5261
5262 if (!Info.Constructor->isInvalidDecl() &&
5263 Info.Constructor->isConvertingConstructor(/*AllowExplicit*/true)) {
5264 if (Info.ConstructorTmpl)
5265 S.AddTemplateOverloadCandidate(
5266 Info.ConstructorTmpl, Info.FoundDecl,
5267 /*ExplicitArgs*/ nullptr, Initializer, CandidateSet,
5268 /*SuppressUserConversions=*/true,
5269 /*PartialOverloading*/ false, AllowExplicit);
5270 else
5271 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
5272 Initializer, CandidateSet,
5273 /*SuppressUserConversions=*/true,
5274 /*PartialOverloading*/ false, AllowExplicit);
5275 }
5276 }
5277 }
5278 }
5279
5280 SourceLocation DeclLoc = Initializer->getBeginLoc();
5281
5282 if (const RecordType *SourceRecordType = SourceType->getAs<RecordType>()) {
5283 // The type we're converting from is a class type, enumerate its conversion
5284 // functions.
5285
5286 // We can only enumerate the conversion functions for a complete type; if
5287 // the type isn't complete, simply skip this step.
5288 if (S.isCompleteType(DeclLoc, SourceType)) {
5289 CXXRecordDecl *SourceRecordDecl
5290 = cast<CXXRecordDecl>(SourceRecordType->getDecl());
5291
5292 const auto &Conversions =
5293 SourceRecordDecl->getVisibleConversionFunctions();
5294 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
5295 NamedDecl *D = *I;
5296 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
5297 if (isa<UsingShadowDecl>(D))
5298 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5299
5300 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
5301 CXXConversionDecl *Conv;
5302 if (ConvTemplate)
5303 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5304 else
5305 Conv = cast<CXXConversionDecl>(D);
5306
5307 if (ConvTemplate)
5308 S.AddTemplateConversionCandidate(
5309 ConvTemplate, I.getPair(), ActingDC, Initializer, DestType,
5310 CandidateSet, AllowExplicit, AllowExplicit);
5311 else
5312 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Initializer,
5313 DestType, CandidateSet, AllowExplicit,
5314 AllowExplicit);
5315 }
5316 }
5317 }
5318
5319 // Perform overload resolution. If it fails, return the failed result.
5320 OverloadCandidateSet::iterator Best;
5321 if (OverloadingResult Result
5322 = CandidateSet.BestViableFunction(S, DeclLoc, Best)) {
5323 Sequence.SetOverloadFailure(
5324 InitializationSequence::FK_UserConversionOverloadFailed, Result);
5325
5326 // [class.copy.elision]p3:
5327 // In some copy-initialization contexts, a two-stage overload resolution
5328 // is performed.
5329 // If the first overload resolution selects a deleted function, we also
5330 // need the initialization sequence to decide whether to perform the second
5331 // overload resolution.
5332 if (!(Result == OR_Deleted &&
5333 Kind.getKind() == InitializationKind::IK_Copy))
5334 return;
5335 }
5336
5337 FunctionDecl *Function = Best->Function;
5338 Function->setReferenced();
5339 bool HadMultipleCandidates = (CandidateSet.size() > 1);
5340
5341 if (isa<CXXConstructorDecl>(Function)) {
5342 // Add the user-defined conversion step. Any cv-qualification conversion is
5343 // subsumed by the initialization. Per DR5, the created temporary is of the
5344 // cv-unqualified type of the destination.
5345 Sequence.AddUserConversionStep(Function, Best->FoundDecl,
5346 DestType.getUnqualifiedType(),
5347 HadMultipleCandidates);
5348
5349 // C++14 and before:
5350 // - if the function is a constructor, the call initializes a temporary
5351 // of the cv-unqualified version of the destination type. The [...]
5352 // temporary [...] is then used to direct-initialize, according to the
5353 // rules above, the object that is the destination of the
5354 // copy-initialization.
5355 // Note that this just performs a simple object copy from the temporary.
5356 //
5357 // C++17:
5358 // - if the function is a constructor, the call is a prvalue of the
5359 // cv-unqualified version of the destination type whose return object
5360 // is initialized by the constructor. The call is used to
5361 // direct-initialize, according to the rules above, the object that
5362 // is the destination of the copy-initialization.
5363 // Therefore we need to do nothing further.
5364 //
5365 // FIXME: Mark this copy as extraneous.
5366 if (!S.getLangOpts().CPlusPlus17)
5367 Sequence.AddFinalCopy(DestType);
5368 else if (DestType.hasQualifiers())
5369 Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
5370 return;
5371 }
5372
5373 // Add the user-defined conversion step that calls the conversion function.
5374 QualType ConvType = Function->getCallResultType();
5375 Sequence.AddUserConversionStep(Function, Best->FoundDecl, ConvType,
5376 HadMultipleCandidates);
5377
5378 if (ConvType->getAs<RecordType>()) {
5379 // The call is used to direct-initialize [...] the object that is the
5380 // destination of the copy-initialization.
5381 //
5382 // In C++17, this does not call a constructor if we enter /17.6.1:
5383 // - If the initializer expression is a prvalue and the cv-unqualified
5384 // version of the source type is the same as the class of the
5385 // destination [... do not make an extra copy]
5386 //
5387 // FIXME: Mark this copy as extraneous.
5388 if (!S.getLangOpts().CPlusPlus17 ||
5389 Function->getReturnType()->isReferenceType() ||
5390 !S.Context.hasSameUnqualifiedType(ConvType, DestType))
5391 Sequence.AddFinalCopy(DestType);
5392 else if (!S.Context.hasSameType(ConvType, DestType))
5393 Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
5394 return;
5395 }
5396
5397 // If the conversion following the call to the conversion function
5398 // is interesting, add it as a separate step.
5399 if (Best->FinalConversion.First || Best->FinalConversion.Second ||
5400 Best->FinalConversion.Third) {
5401 ImplicitConversionSequence ICS;
5402 ICS.setStandard();
5403 ICS.Standard = Best->FinalConversion;
5404 Sequence.AddConversionSequenceStep(ICS, DestType, TopLevelOfInitList);
5405 }
5406}
5407
5408/// An egregious hack for compatibility with libstdc++-4.2: in <tr1/hashtable>,
5409/// a function with a pointer return type contains a 'return false;' statement.
5410/// In C++11, 'false' is not a null pointer, so this breaks the build of any
5411/// code using that header.
5412///
5413/// Work around this by treating 'return false;' as zero-initializing the result
5414/// if it's used in a pointer-returning function in a system header.
5415static bool isLibstdcxxPointerReturnFalseHack(Sema &S,
5416 const InitializedEntity &Entity,
5417 const Expr *Init) {
5418 return S.getLangOpts().CPlusPlus11 &&
5419 Entity.getKind() == InitializedEntity::EK_Result &&
5420 Entity.getType()->isPointerType() &&
5421 isa<CXXBoolLiteralExpr>(Init) &&
5422 !cast<CXXBoolLiteralExpr>(Init)->getValue() &&
5423 S.getSourceManager().isInSystemHeader(Init->getExprLoc());
5424}
5425
5426/// The non-zero enum values here are indexes into diagnostic alternatives.
5427enum InvalidICRKind { IIK_okay, IIK_nonlocal, IIK_nonscalar };
5428
5429/// Determines whether this expression is an acceptable ICR source.
5430static InvalidICRKind isInvalidICRSource(ASTContext &C, Expr *e,
5431 bool isAddressOf, bool &isWeakAccess) {
5432 // Skip parens.
5433 e = e->IgnoreParens();
5434
5435 // Skip address-of nodes.
5436 if (UnaryOperator *op = dyn_cast<UnaryOperator>(e)) {
5437 if (op->getOpcode() == UO_AddrOf)
5438 return isInvalidICRSource(C, op->getSubExpr(), /*addressof*/ true,
5439 isWeakAccess);
5440
5441 // Skip certain casts.
5442 } else if (CastExpr *ce = dyn_cast<CastExpr>(e)) {
5443 switch (ce->getCastKind()) {
5444 case CK_Dependent:
5445 case CK_BitCast:
5446 case CK_LValueBitCast:
5447 case CK_NoOp:
5448 return isInvalidICRSource(C, ce->getSubExpr(), isAddressOf, isWeakAccess);
5449
5450 case CK_ArrayToPointerDecay:
5451 return IIK_nonscalar;
5452
5453 case CK_NullToPointer:
5454 return IIK_okay;
5455
5456 default:
5457 break;
5458 }
5459
5460 // If we have a declaration reference, it had better be a local variable.
5461 } else if (isa<DeclRefExpr>(e)) {
5462 // set isWeakAccess to true, to mean that there will be an implicit
5463 // load which requires a cleanup.
5464 if (e->getType().getObjCLifetime() == Qualifiers::OCL_Weak)
5465 isWeakAccess = true;
5466
5467 if (!isAddressOf) return IIK_nonlocal;
5468
5469 VarDecl *var = dyn_cast<VarDecl>(cast<DeclRefExpr>(e)->getDecl());
5470 if (!var) return IIK_nonlocal;
5471
5472 return (var->hasLocalStorage() ? IIK_okay : IIK_nonlocal);
5473
5474 // If we have a conditional operator, check both sides.
5475 } else if (ConditionalOperator *cond = dyn_cast<ConditionalOperator>(e)) {
5476 if (InvalidICRKind iik = isInvalidICRSource(C, cond->getLHS(), isAddressOf,
5477 isWeakAccess))
5478 return iik;
5479
5480 return isInvalidICRSource(C, cond->getRHS(), isAddressOf, isWeakAccess);
5481
5482 // These are never scalar.
5483 } else if (isa<ArraySubscriptExpr>(e)) {
5484 return IIK_nonscalar;
5485
5486 // Otherwise, it needs to be a null pointer constant.
5487 } else {
5488 return (e->isNullPointerConstant(C, Expr::NPC_ValueDependentIsNull)
5489 ? IIK_okay : IIK_nonlocal);
5490 }
5491
5492 return IIK_nonlocal;
5493}
5494
5495/// Check whether the given expression is a valid operand for an
5496/// indirect copy/restore.
5497static void checkIndirectCopyRestoreSource(Sema &S, Expr *src) {
5498 assert(src->isPRValue())((void)0);
5499 bool isWeakAccess = false;
5500 InvalidICRKind iik = isInvalidICRSource(S.Context, src, false, isWeakAccess);
5501 // If isWeakAccess to true, there will be an implicit
5502 // load which requires a cleanup.
5503 if (S.getLangOpts().ObjCAutoRefCount && isWeakAccess)
5504 S.Cleanup.setExprNeedsCleanups(true);
5505
5506 if (iik == IIK_okay) return;
5507
5508 S.Diag(src->getExprLoc(), diag::err_arc_nonlocal_writeback)
5509 << ((unsigned) iik - 1) // shift index into diagnostic explanations
5510 << src->getSourceRange();
5511}
5512
5513/// Determine whether we have compatible array types for the
5514/// purposes of GNU by-copy array initialization.
5515static bool hasCompatibleArrayTypes(ASTContext &Context, const ArrayType *Dest,
5516 const ArrayType *Source) {
5517 // If the source and destination array types are equivalent, we're
5518 // done.
5519 if (Context.hasSameType(QualType(Dest, 0), QualType(Source, 0)))
5520 return true;
5521
5522 // Make sure that the element types are the same.
5523 if (!Context.hasSameType(Dest->getElementType(), Source->getElementType()))
5524 return false;
5525
5526 // The only mismatch we allow is when the destination is an
5527 // incomplete array type and the source is a constant array type.
5528 return Source->isConstantArrayType() && Dest->isIncompleteArrayType();
5529}
5530
5531static bool tryObjCWritebackConversion(Sema &S,
5532 InitializationSequence &Sequence,
5533 const InitializedEntity &Entity,
5534 Expr *Initializer) {
5535 bool ArrayDecay = false;
5536 QualType ArgType = Initializer->getType();
5537 QualType ArgPointee;
5538 if (const ArrayType *ArgArrayType = S.Context.getAsArrayType(ArgType)) {
5539 ArrayDecay = true;
5540 ArgPointee = ArgArrayType->getElementType();
5541 ArgType = S.Context.getPointerType(ArgPointee);
5542 }
5543
5544 // Handle write-back conversion.
5545 QualType ConvertedArgType;
5546 if (!S.isObjCWritebackConversion(ArgType, Entity.getType(),
5547 ConvertedArgType))
5548 return false;
5549
5550 // We should copy unless we're passing to an argument explicitly
5551 // marked 'out'.
5552 bool ShouldCopy = true;
5553 if (ParmVarDecl *param = cast_or_null<ParmVarDecl>(Entity.getDecl()))
5554 ShouldCopy = (param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out);
5555
5556 // Do we need an lvalue conversion?
5557 if (ArrayDecay || Initializer->isGLValue()) {
5558 ImplicitConversionSequence ICS;
5559 ICS.setStandard();
5560 ICS.Standard.setAsIdentityConversion();
5561
5562 QualType ResultType;
5563 if (ArrayDecay) {
5564 ICS.Standard.First = ICK_Array_To_Pointer;
5565 ResultType = S.Context.getPointerType(ArgPointee);
5566 } else {
5567 ICS.Standard.First = ICK_Lvalue_To_Rvalue;
5568 ResultType = Initializer->getType().getNonLValueExprType(S.Context);
5569 }
5570
5571 Sequence.AddConversionSequenceStep(ICS, ResultType);
5572 }
5573
5574 Sequence.AddPassByIndirectCopyRestoreStep(Entity.getType(), ShouldCopy);
5575 return true;
5576}
5577
5578static bool TryOCLSamplerInitialization(Sema &S,
5579 InitializationSequence &Sequence,
5580 QualType DestType,
5581 Expr *Initializer) {
5582 if (!S.getLangOpts().OpenCL || !DestType->isSamplerT() ||
5583 (!Initializer->isIntegerConstantExpr(S.Context) &&
5584 !Initializer->getType()->isSamplerT()))
5585 return false;
5586
5587 Sequence.AddOCLSamplerInitStep(DestType);
5588 return true;
5589}
5590
5591static bool IsZeroInitializer(Expr *Initializer, Sema &S) {
5592 return Initializer->isIntegerConstantExpr(S.getASTContext()) &&
5593 (Initializer->EvaluateKnownConstInt(S.getASTContext()) == 0);
5594}
5595
5596static bool TryOCLZeroOpaqueTypeInitialization(Sema &S,
5597 InitializationSequence &Sequence,
5598 QualType DestType,
5599 Expr *Initializer) {
5600 if (!S.getLangOpts().OpenCL)
5601 return false;
5602
5603 //
5604 // OpenCL 1.2 spec, s6.12.10
5605 //
5606 // The event argument can also be used to associate the
5607 // async_work_group_copy with a previous async copy allowing
5608 // an event to be shared by multiple async copies; otherwise
5609 // event should be zero.
5610 //
5611 if (DestType->isEventT() || DestType->isQueueT()) {
5612 if (!IsZeroInitializer(Initializer, S))
5613 return false;
5614
5615 Sequence.AddOCLZeroOpaqueTypeStep(DestType);
5616 return true;
5617 }
5618
5619 // We should allow zero initialization for all types defined in the
5620 // cl_intel_device_side_avc_motion_estimation extension, except
5621 // intel_sub_group_avc_mce_payload_t and intel_sub_group_avc_mce_result_t.
5622 if (S.getOpenCLOptions().isAvailableOption(
5623 "cl_intel_device_side_avc_motion_estimation", S.getLangOpts()) &&
5624 DestType->isOCLIntelSubgroupAVCType()) {
5625 if (DestType->isOCLIntelSubgroupAVCMcePayloadType() ||
5626 DestType->isOCLIntelSubgroupAVCMceResultType())
5627 return false;
5628 if (!IsZeroInitializer(Initializer, S))
5629 return false;
5630
5631 Sequence.AddOCLZeroOpaqueTypeStep(DestType);
5632 return true;
5633 }
5634
5635 return false;
5636}
5637
5638InitializationSequence::InitializationSequence(
5639 Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind,
5640 MultiExprArg Args, bool TopLevelOfInitList, bool TreatUnavailableAsInvalid)
5641 : FailedOverloadResult(OR_Success),
5642 FailedCandidateSet(Kind.getLocation(), OverloadCandidateSet::CSK_Normal) {
5643 InitializeFrom(S, Entity, Kind, Args, TopLevelOfInitList,
5644 TreatUnavailableAsInvalid);
5645}
5646
5647/// Tries to get a FunctionDecl out of `E`. If it succeeds and we can take the
5648/// address of that function, this returns true. Otherwise, it returns false.
5649static bool isExprAnUnaddressableFunction(Sema &S, const Expr *E) {
5650 auto *DRE = dyn_cast<DeclRefExpr>(E);
5651 if (!DRE || !isa<FunctionDecl>(DRE->getDecl()))
5652 return false;
5653
5654 return !S.checkAddressOfFunctionIsAvailable(
5655 cast<FunctionDecl>(DRE->getDecl()));
5656}
5657
5658/// Determine whether we can perform an elementwise array copy for this kind
5659/// of entity.
5660static bool canPerformArrayCopy(const InitializedEntity &Entity) {
5661 switch (Entity.getKind()) {
5662 case InitializedEntity::EK_LambdaCapture:
5663 // C++ [expr.prim.lambda]p24:
5664 // For array members, the array elements are direct-initialized in
5665 // increasing subscript order.
5666 return true;
5667
5668 case InitializedEntity::EK_Variable:
5669 // C++ [dcl.decomp]p1:
5670 // [...] each element is copy-initialized or direct-initialized from the
5671 // corresponding element of the assignment-expression [...]
5672 return isa<DecompositionDecl>(Entity.getDecl());
5673
5674 case InitializedEntity::EK_Member:
5675 // C++ [class.copy.ctor]p14:
5676 // - if the member is an array, each element is direct-initialized with
5677 // the corresponding subobject of x
5678 return Entity.isImplicitMemberInitializer();
5679
5680 case InitializedEntity::EK_ArrayElement:
5681 // All the above cases are intended to apply recursively, even though none
5682 // of them actually say that.
5683 if (auto *E = Entity.getParent())
5684 return canPerformArrayCopy(*E);
5685 break;
5686
5687 default:
5688 break;
5689 }
5690
5691 return false;
5692}
5693
5694void InitializationSequence::InitializeFrom(Sema &S,
5695 const InitializedEntity &Entity,
5696 const InitializationKind &Kind,
5697 MultiExprArg Args,
5698 bool TopLevelOfInitList,
5699 bool TreatUnavailableAsInvalid) {
5700 ASTContext &Context = S.Context;
5701
5702 // Eliminate non-overload placeholder types in the arguments. We
5703 // need to do this before checking whether types are dependent
5704 // because lowering a pseudo-object expression might well give us
5705 // something of dependent type.
5706 for (unsigned I = 0, E = Args.size(); I != E; ++I)
5707 if (Args[I]->getType()->isNonOverloadPlaceholderType()) {
5708 // FIXME: should we be doing this here?
5709 ExprResult result = S.CheckPlaceholderExpr(Args[I]);
5710 if (result.isInvalid()) {
5711 SetFailed(FK_PlaceholderType);
5712 return;
5713 }
5714 Args[I] = result.get();
5715 }
5716
5717 // C++0x [dcl.init]p16:
5718 // The semantics of initializers are as follows. The destination type is
5719 // the type of the object or reference being initialized and the source
5720 // type is the type of the initializer expression. The source type is not
5721 // defined when the initializer is a braced-init-list or when it is a
5722 // parenthesized list of expressions.
5723 QualType DestType = Entity.getType();
5724
5725 if (DestType->isDependentType() ||
5726 Expr::hasAnyTypeDependentArguments(Args)) {
5727 SequenceKind = DependentSequence;
5728 return;
5729 }
5730
5731 // Almost everything is a normal sequence.
5732 setSequenceKind(NormalSequence);
5733
5734 QualType SourceType;
5735 Expr *Initializer = nullptr;
5736 if (Args.size() == 1) {
5737 Initializer = Args[0];
5738 if (S.getLangOpts().ObjC) {
5739 if (S.CheckObjCBridgeRelatedConversions(Initializer->getBeginLoc(),
5740 DestType, Initializer->getType(),
5741 Initializer) ||
5742 S.CheckConversionToObjCLiteral(DestType, Initializer))
5743 Args[0] = Initializer;
5744 }
5745 if (!isa<InitListExpr>(Initializer))
5746 SourceType = Initializer->getType();
5747 }
5748
5749 // - If the initializer is a (non-parenthesized) braced-init-list, the
5750 // object is list-initialized (8.5.4).
5751 if (Kind.getKind() != InitializationKind::IK_Direct) {
5752 if (InitListExpr *InitList = dyn_cast_or_null<InitListExpr>(Initializer)) {
5753 TryListInitialization(S, Entity, Kind, InitList, *this,
5754 TreatUnavailableAsInvalid);
5755 return;
5756 }
5757 }
5758
5759 // - If the destination type is a reference type, see 8.5.3.
5760 if (DestType->isReferenceType()) {
5761 // C++0x [dcl.init.ref]p1:
5762 // A variable declared to be a T& or T&&, that is, "reference to type T"
5763 // (8.3.2), shall be initialized by an object, or function, of type T or
5764 // by an object that can be converted into a T.
5765 // (Therefore, multiple arguments are not permitted.)
5766 if (Args.size() != 1)
5767 SetFailed(FK_TooManyInitsForReference);
5768 // C++17 [dcl.init.ref]p5:
5769 // A reference [...] is initialized by an expression [...] as follows:
5770 // If the initializer is not an expression, presumably we should reject,
5771 // but the standard fails to actually say so.
5772 else if (isa<InitListExpr>(Args[0]))
5773 SetFailed(FK_ParenthesizedListInitForReference);
5774 else
5775 TryReferenceInitialization(S, Entity, Kind, Args[0], *this);
5776 return;
5777 }
5778
5779 // - If the initializer is (), the object is value-initialized.
5780 if (Kind.getKind() == InitializationKind::IK_Value ||
5781 (Kind.getKind() == InitializationKind::IK_Direct && Args.empty())) {
5782 TryValueInitialization(S, Entity, Kind, *this);
5783 return;
5784 }
5785
5786 // Handle default initialization.
5787 if (Kind.getKind() == InitializationKind::IK_Default) {
5788 TryDefaultInitialization(S, Entity, Kind, *this);
5789 return;
5790 }
5791
5792 // - If the destination type is an array of characters, an array of
5793 // char16_t, an array of char32_t, or an array of wchar_t, and the
5794 // initializer is a string literal, see 8.5.2.
5795 // - Otherwise, if the destination type is an array, the program is
5796 // ill-formed.
5797 if (const ArrayType *DestAT = Context.getAsArrayType(DestType)) {
5798 if (Initializer && isa<VariableArrayType>(DestAT)) {
5799 SetFailed(FK_VariableLengthArrayHasInitializer);
5800 return;
5801 }
5802
5803 if (Initializer) {
5804 switch (IsStringInit(Initializer, DestAT, Context)) {
5805 case SIF_None:
5806 TryStringLiteralInitialization(S, Entity, Kind, Initializer, *this);
5807 return;
5808 case SIF_NarrowStringIntoWideChar:
5809 SetFailed(FK_NarrowStringIntoWideCharArray);
5810 return;
5811 case SIF_WideStringIntoChar:
5812 SetFailed(FK_WideStringIntoCharArray);
5813 return;
5814 case SIF_IncompatWideStringIntoWideChar:
5815 SetFailed(FK_IncompatWideStringIntoWideChar);
5816 return;
5817 case SIF_PlainStringIntoUTF8Char:
5818 SetFailed(FK_PlainStringIntoUTF8Char);
5819 return;
5820 case SIF_UTF8StringIntoPlainChar:
5821 SetFailed(FK_UTF8StringIntoPlainChar);
5822 return;
5823 case SIF_Other:
5824 break;
5825 }
5826 }
5827
5828 // Some kinds of initialization permit an array to be initialized from
5829 // another array of the same type, and perform elementwise initialization.
5830 if (Initializer && isa<ConstantArrayType>(DestAT) &&
5831 S.Context.hasSameUnqualifiedType(Initializer->getType(),
5832 Entity.getType()) &&
5833 canPerformArrayCopy(Entity)) {
5834 // If source is a prvalue, use it directly.
5835 if (Initializer->isPRValue()) {
5836 AddArrayInitStep(DestType, /*IsGNUExtension*/false);
5837 return;
5838 }
5839
5840 // Emit element-at-a-time copy loop.
5841 InitializedEntity Element =
5842 InitializedEntity::InitializeElement(S.Context, 0, Entity);
5843 QualType InitEltT =
5844 Context.getAsArrayType(Initializer->getType())->getElementType();
5845 OpaqueValueExpr OVE(Initializer->getExprLoc(), InitEltT,
5846 Initializer->getValueKind(),
5847 Initializer->getObjectKind());
5848 Expr *OVEAsExpr = &OVE;
5849 InitializeFrom(S, Element, Kind, OVEAsExpr, TopLevelOfInitList,
5850 TreatUnavailableAsInvalid);
5851 if (!Failed())
5852 AddArrayInitLoopStep(Entity.getType(), InitEltT);
5853 return;
5854 }
5855
5856 // Note: as an GNU C extension, we allow initialization of an
5857 // array from a compound literal that creates an array of the same
5858 // type, so long as the initializer has no side effects.
5859 if (!S.getLangOpts().CPlusPlus && Initializer &&
5860 isa<CompoundLiteralExpr>(Initializer->IgnoreParens()) &&
5861 Initializer->getType()->isArrayType()) {
5862 const ArrayType *SourceAT
5863 = Context.getAsArrayType(Initializer->getType());
5864 if (!hasCompatibleArrayTypes(S.Context, DestAT, SourceAT))
5865 SetFailed(FK_ArrayTypeMismatch);
5866 else if (Initializer->HasSideEffects(S.Context))
5867 SetFailed(FK_NonConstantArrayInit);
5868 else {
5869 AddArrayInitStep(DestType, /*IsGNUExtension*/true);
5870 }
5871 }
5872 // Note: as a GNU C++ extension, we allow list-initialization of a
5873 // class member of array type from a parenthesized initializer list.
5874 else if (S.getLangOpts().CPlusPlus &&
5875 Entity.getKind() == InitializedEntity::EK_Member &&
5876 Initializer && isa<InitListExpr>(Initializer)) {
5877 TryListInitialization(S, Entity, Kind, cast<InitListExpr>(Initializer),
5878 *this, TreatUnavailableAsInvalid);
5879 AddParenthesizedArrayInitStep(DestType);
5880 } else if (DestAT->getElementType()->isCharType())
5881 SetFailed(FK_ArrayNeedsInitListOrStringLiteral);
5882 else if (IsWideCharCompatible(DestAT->getElementType(), Context))
5883 SetFailed(FK_ArrayNeedsInitListOrWideStringLiteral);
5884 else
5885 SetFailed(FK_ArrayNeedsInitList);
5886
5887 return;
5888 }
5889
5890 // Determine whether we should consider writeback conversions for
5891 // Objective-C ARC.
5892 bool allowObjCWritebackConversion = S.getLangOpts().ObjCAutoRefCount &&
5893 Entity.isParameterKind();
5894
5895 if (TryOCLSamplerInitialization(S, *this, DestType, Initializer))
5896 return;
5897
5898 // We're at the end of the line for C: it's either a write-back conversion
5899 // or it's a C assignment. There's no need to check anything else.
5900 if (!S.getLangOpts().CPlusPlus) {
5901 // If allowed, check whether this is an Objective-C writeback conversion.
5902 if (allowObjCWritebackConversion &&
5903 tryObjCWritebackConversion(S, *this, Entity, Initializer)) {
5904 return;
5905 }
5906
5907 if (TryOCLZeroOpaqueTypeInitialization(S, *this, DestType, Initializer))
5908 return;
5909
5910 // Handle initialization in C
5911 AddCAssignmentStep(DestType);
5912 MaybeProduceObjCObject(S, *this, Entity);
5913 return;
5914 }
5915
5916 assert(S.getLangOpts().CPlusPlus)((void)0);
5917
5918 // - If the destination type is a (possibly cv-qualified) class type:
5919 if (DestType->isRecordType()) {
5920 // - If the initialization is direct-initialization, or if it is
5921 // copy-initialization where the cv-unqualified version of the
5922 // source type is the same class as, or a derived class of, the
5923 // class of the destination, constructors are considered. [...]
5924 if (Kind.getKind() == InitializationKind::IK_Direct ||
5925 (Kind.getKind() == InitializationKind::IK_Copy &&
5926 (Context.hasSameUnqualifiedType(SourceType, DestType) ||
5927 S.IsDerivedFrom(Initializer->getBeginLoc(), SourceType, DestType))))
5928 TryConstructorInitialization(S, Entity, Kind, Args,
5929 DestType, DestType, *this);
5930 // - Otherwise (i.e., for the remaining copy-initialization cases),
5931 // user-defined conversion sequences that can convert from the source
5932 // type to the destination type or (when a conversion function is
5933 // used) to a derived class thereof are enumerated as described in
5934 // 13.3.1.4, and the best one is chosen through overload resolution
5935 // (13.3).
5936 else
5937 TryUserDefinedConversion(S, DestType, Kind, Initializer, *this,
5938 TopLevelOfInitList);
5939 return;
5940 }
5941
5942 assert(Args.size() >= 1 && "Zero-argument case handled above")((void)0);
5943
5944 // The remaining cases all need a source type.
5945 if (Args.size() > 1) {
5946 SetFailed(FK_TooManyInitsForScalar);
5947 return;
5948 } else if (isa<InitListExpr>(Args[0])) {
5949 SetFailed(FK_ParenthesizedListInitForScalar);
5950 return;
5951 }
5952
5953 // - Otherwise, if the source type is a (possibly cv-qualified) class
5954 // type, conversion functions are considered.
5955 if (!SourceType.isNull() && SourceType->isRecordType()) {
5956 // For a conversion to _Atomic(T) from either T or a class type derived
5957 // from T, initialize the T object then convert to _Atomic type.
5958 bool NeedAtomicConversion = false;
5959 if (const AtomicType *Atomic = DestType->getAs<AtomicType>()) {
5960 if (Context.hasSameUnqualifiedType(SourceType, Atomic->getValueType()) ||
5961 S.IsDerivedFrom(Initializer->getBeginLoc(), SourceType,
5962 Atomic->getValueType())) {
5963 DestType = Atomic->getValueType();
5964 NeedAtomicConversion = true;
5965 }
5966 }
5967
5968 TryUserDefinedConversion(S, DestType, Kind, Initializer, *this,
5969 TopLevelOfInitList);
5970 MaybeProduceObjCObject(S, *this, Entity);
5971 if (!Failed() && NeedAtomicConversion)
5972 AddAtomicConversionStep(Entity.getType());
5973 return;
5974 }
5975
5976 // - Otherwise, if the initialization is direct-initialization, the source
5977 // type is std::nullptr_t, and the destination type is bool, the initial
5978 // value of the object being initialized is false.
5979 if (!SourceType.isNull() && SourceType->isNullPtrType() &&
5980 DestType->isBooleanType() &&
5981 Kind.getKind() == InitializationKind::IK_Direct) {
5982 AddConversionSequenceStep(
5983 ImplicitConversionSequence::getNullptrToBool(SourceType, DestType,
5984 Initializer->isGLValue()),
5985 DestType);
5986 return;
5987 }
5988
5989 // - Otherwise, the initial value of the object being initialized is the
5990 // (possibly converted) value of the initializer expression. Standard
5991 // conversions (Clause 4) will be used, if necessary, to convert the
5992 // initializer expression to the cv-unqualified version of the
5993 // destination type; no user-defined conversions are considered.
5994
5995 ImplicitConversionSequence ICS
5996 = S.TryImplicitConversion(Initializer, DestType,
5997 /*SuppressUserConversions*/true,
5998 Sema::AllowedExplicit::None,
5999 /*InOverloadResolution*/ false,
6000 /*CStyle=*/Kind.isCStyleOrFunctionalCast(),
6001 allowObjCWritebackConversion);
6002
6003 if (ICS.isStandard() &&
6004 ICS.Standard.Second == ICK_Writeback_Conversion) {
6005 // Objective-C ARC writeback conversion.
6006
6007 // We should copy unless we're passing to an argument explicitly
6008 // marked 'out'.
6009 bool ShouldCopy = true;
6010 if (ParmVarDecl *Param = cast_or_null<ParmVarDecl>(Entity.getDecl()))
6011 ShouldCopy = (Param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out);
6012
6013 // If there was an lvalue adjustment, add it as a separate conversion.
6014 if (ICS.Standard.First == ICK_Array_To_Pointer ||
6015 ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
6016 ImplicitConversionSequence LvalueICS;
6017 LvalueICS.setStandard();
6018 LvalueICS.Standard.setAsIdentityConversion();
6019 LvalueICS.Standard.setAllToTypes(ICS.Standard.getToType(0));
6020 LvalueICS.Standard.First = ICS.Standard.First;
6021 AddConversionSequenceStep(LvalueICS, ICS.Standard.getToType(0));
6022 }
6023
6024 AddPassByIndirectCopyRestoreStep(DestType, ShouldCopy);
6025 } else if (ICS.isBad()) {
6026 DeclAccessPair dap;
6027 if (isLibstdcxxPointerReturnFalseHack(S, Entity, Initializer)) {
6028 AddZeroInitializationStep(Entity.getType());
6029 } else if (Initializer->getType() == Context.OverloadTy &&
6030 !S.ResolveAddressOfOverloadedFunction(Initializer, DestType,
6031 false, dap))
6032 SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
6033 else if (Initializer->getType()->isFunctionType() &&
6034 isExprAnUnaddressableFunction(S, Initializer))
6035 SetFailed(InitializationSequence::FK_AddressOfUnaddressableFunction);
6036 else
6037 SetFailed(InitializationSequence::FK_ConversionFailed);
6038 } else {
6039 AddConversionSequenceStep(ICS, DestType, TopLevelOfInitList);
6040
6041 MaybeProduceObjCObject(S, *this, Entity);
6042 }
6043}
6044
6045InitializationSequence::~InitializationSequence() {
6046 for (auto &S : Steps)
6047 S.Destroy();
6048}
6049
6050//===----------------------------------------------------------------------===//
6051// Perform initialization
6052//===----------------------------------------------------------------------===//
6053static Sema::AssignmentAction
6054getAssignmentAction(const InitializedEntity &Entity, bool Diagnose = false) {
6055 switch(Entity.getKind()) {
6056 case InitializedEntity::EK_Variable:
6057 case InitializedEntity::EK_New:
6058 case InitializedEntity::EK_Exception:
6059 case InitializedEntity::EK_Base:
6060 case InitializedEntity::EK_Delegating:
6061 return Sema::AA_Initializing;
6062
6063 case InitializedEntity::EK_Parameter:
6064 if (Entity.getDecl() &&
6065 isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext()))
6066 return Sema::AA_Sending;
6067
6068 return Sema::AA_Passing;
6069
6070 case InitializedEntity::EK_Parameter_CF_Audited:
6071 if (Entity.getDecl() &&
6072 isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext()))
6073 return Sema::AA_Sending;
6074
6075 return !Diagnose ? Sema::AA_Passing : Sema::AA_Passing_CFAudited;
6076
6077 case InitializedEntity::EK_Result:
6078 case InitializedEntity::EK_StmtExprResult: // FIXME: Not quite right.
6079 return Sema::AA_Returning;
6080
6081 case InitializedEntity::EK_Temporary:
6082 case InitializedEntity::EK_RelatedResult:
6083 // FIXME: Can we tell apart casting vs. converting?
6084 return Sema::AA_Casting;
6085
6086 case InitializedEntity::EK_TemplateParameter:
6087 // This is really initialization, but refer to it as conversion for
6088 // consistency with CheckConvertedConstantExpression.
6089 return Sema::AA_Converting;
6090
6091 case InitializedEntity::EK_Member:
6092 case InitializedEntity::EK_Binding:
6093 case InitializedEntity::EK_ArrayElement:
6094 case InitializedEntity::EK_VectorElement:
6095 case InitializedEntity::EK_ComplexElement:
6096 case InitializedEntity::EK_BlockElement:
6097 case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
6098 case InitializedEntity::EK_LambdaCapture:
6099 case InitializedEntity::EK_CompoundLiteralInit:
6100 return Sema::AA_Initializing;
6101 }
6102
6103 llvm_unreachable("Invalid EntityKind!")__builtin_unreachable();
6104}
6105
6106/// Whether we should bind a created object as a temporary when
6107/// initializing the given entity.
6108static bool shouldBindAsTemporary(const InitializedEntity &Entity) {
6109 switch (Entity.getKind()) {
6110 case InitializedEntity::EK_ArrayElement:
6111 case InitializedEntity::EK_Member:
6112 case InitializedEntity::EK_Result:
6113 case InitializedEntity::EK_StmtExprResult:
6114 case InitializedEntity::EK_New:
6115 case InitializedEntity::EK_Variable:
6116 case InitializedEntity::EK_Base:
6117 case InitializedEntity::EK_Delegating:
6118 case InitializedEntity::EK_VectorElement:
6119 case InitializedEntity::EK_ComplexElement:
6120 case InitializedEntity::EK_Exception:
6121 case InitializedEntity::EK_BlockElement:
6122 case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
6123 case InitializedEntity::EK_LambdaCapture:
6124 case InitializedEntity::EK_CompoundLiteralInit:
6125 case InitializedEntity::EK_TemplateParameter:
6126 return false;
6127
6128 case InitializedEntity::EK_Parameter:
6129 case InitializedEntity::EK_Parameter_CF_Audited:
6130 case InitializedEntity::EK_Temporary:
6131 case InitializedEntity::EK_RelatedResult:
6132 case InitializedEntity::EK_Binding:
6133 return true;
6134 }
6135
6136 llvm_unreachable("missed an InitializedEntity kind?")__builtin_unreachable();
6137}
6138
6139/// Whether the given entity, when initialized with an object
6140/// created for that initialization, requires destruction.
6141static bool shouldDestroyEntity(const InitializedEntity &Entity) {
6142 switch (Entity.getKind()) {
6143 case InitializedEntity::EK_Result:
6144 case InitializedEntity::EK_StmtExprResult:
6145 case InitializedEntity::EK_New:
6146 case InitializedEntity::EK_Base:
6147 case InitializedEntity::EK_Delegating:
6148 case InitializedEntity::EK_VectorElement:
6149 case InitializedEntity::EK_ComplexElement:
6150 case InitializedEntity::EK_BlockElement:
6151 case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
6152 case InitializedEntity::EK_LambdaCapture:
6153 return false;
6154
6155 case InitializedEntity::EK_Member:
6156 case InitializedEntity::EK_Binding:
6157 case InitializedEntity::EK_Variable:
6158 case InitializedEntity::EK_Parameter:
6159 case InitializedEntity::EK_Parameter_CF_Audited:
6160 case InitializedEntity::EK_TemplateParameter:
6161 case InitializedEntity::EK_Temporary:
6162 case InitializedEntity::EK_ArrayElement:
6163 case InitializedEntity::EK_Exception:
6164 case InitializedEntity::EK_CompoundLiteralInit:
6165 case InitializedEntity::EK_RelatedResult:
6166 return true;
6167 }
6168
6169 llvm_unreachable("missed an InitializedEntity kind?")__builtin_unreachable();
6170}
6171
6172/// Get the location at which initialization diagnostics should appear.
6173static SourceLocation getInitializationLoc(const InitializedEntity &Entity,
6174 Expr *Initializer) {
6175 switch (Entity.getKind()) {
6176 case InitializedEntity::EK_Result:
6177 case InitializedEntity::EK_StmtExprResult:
6178 return Entity.getReturnLoc();
6179
6180 case InitializedEntity::EK_Exception:
6181 return Entity.getThrowLoc();
6182
6183 case InitializedEntity::EK_Variable:
6184 case InitializedEntity::EK_Binding:
6185 return Entity.getDecl()->getLocation();
6186
6187 case InitializedEntity::EK_LambdaCapture:
6188 return Entity.getCaptureLoc();
6189
6190 case InitializedEntity::EK_ArrayElement:
6191 case InitializedEntity::EK_Member:
6192 case InitializedEntity::EK_Parameter:
6193 case InitializedEntity::EK_Parameter_CF_Audited:
6194 case InitializedEntity::EK_TemplateParameter:
6195 case InitializedEntity::EK_Temporary:
6196 case InitializedEntity::EK_New:
6197 case InitializedEntity::EK_Base:
6198 case InitializedEntity::EK_Delegating:
6199 case InitializedEntity::EK_VectorElement:
6200 case InitializedEntity::EK_ComplexElement:
6201 case InitializedEntity::EK_BlockElement:
6202 case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
6203 case InitializedEntity::EK_CompoundLiteralInit:
6204 case InitializedEntity::EK_RelatedResult:
6205 return Initializer->getBeginLoc();
6206 }
6207 llvm_unreachable("missed an InitializedEntity kind?")__builtin_unreachable();
6208}
6209
6210/// Make a (potentially elidable) temporary copy of the object
6211/// provided by the given initializer by calling the appropriate copy
6212/// constructor.
6213///
6214/// \param S The Sema object used for type-checking.
6215///
6216/// \param T The type of the temporary object, which must either be
6217/// the type of the initializer expression or a superclass thereof.
6218///
6219/// \param Entity The entity being initialized.
6220///
6221/// \param CurInit The initializer expression.
6222///
6223/// \param IsExtraneousCopy Whether this is an "extraneous" copy that
6224/// is permitted in C++03 (but not C++0x) when binding a reference to
6225/// an rvalue.
6226///
6227/// \returns An expression that copies the initializer expression into
6228/// a temporary object, or an error expression if a copy could not be
6229/// created.
6230static ExprResult CopyObject(Sema &S,
6231 QualType T,
6232 const InitializedEntity &Entity,
6233 ExprResult CurInit,
6234 bool IsExtraneousCopy) {
6235 if (CurInit.isInvalid())
6236 return CurInit;
6237 // Determine which class type we're copying to.
6238 Expr *CurInitExpr = (Expr *)CurInit.get();
6239 CXXRecordDecl *Class = nullptr;
6240 if (const RecordType *Record = T->getAs<RecordType>())
6241 Class = cast<CXXRecordDecl>(Record->getDecl());
6242 if (!Class)
6243 return CurInit;
6244
6245 SourceLocation Loc = getInitializationLoc(Entity, CurInit.get());
6246
6247 // Make sure that the type we are copying is complete.
6248 if (S.RequireCompleteType(Loc, T, diag::err_temp_copy_incomplete))
6249 return CurInit;
6250
6251 // Perform overload resolution using the class's constructors. Per
6252 // C++11 [dcl.init]p16, second bullet for class types, this initialization
6253 // is direct-initialization.
6254 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
6255 DeclContext::lookup_result Ctors = S.LookupConstructors(Class);
6256
6257 OverloadCandidateSet::iterator Best;
6258 switch (ResolveConstructorOverload(
6259 S, Loc, CurInitExpr, CandidateSet, T, Ctors, Best,
6260 /*CopyInitializing=*/false, /*AllowExplicit=*/true,
6261 /*OnlyListConstructors=*/false, /*IsListInit=*/false,
6262 /*SecondStepOfCopyInit=*/true)) {
6263 case OR_Success:
6264 break;
6265
6266 case OR_No_Viable_Function:
6267 CandidateSet.NoteCandidates(
6268 PartialDiagnosticAt(
6269 Loc, S.PDiag(IsExtraneousCopy && !S.isSFINAEContext()
6270 ? diag::ext_rvalue_to_reference_temp_copy_no_viable
6271 : diag::err_temp_copy_no_viable)
6272 << (int)Entity.getKind() << CurInitExpr->getType()
6273 << CurInitExpr->getSourceRange()),
6274 S, OCD_AllCandidates, CurInitExpr);
6275 if (!IsExtraneousCopy || S.isSFINAEContext())
6276 return ExprError();
6277 return CurInit;
6278
6279 case OR_Ambiguous:
6280 CandidateSet.NoteCandidates(
6281 PartialDiagnosticAt(Loc, S.PDiag(diag::err_temp_copy_ambiguous)
6282 << (int)Entity.getKind()
6283 << CurInitExpr->getType()
6284 << CurInitExpr->getSourceRange()),
6285 S, OCD_AmbiguousCandidates, CurInitExpr);
6286 return ExprError();
6287
6288 case OR_Deleted:
6289 S.Diag(Loc, diag::err_temp_copy_deleted)
6290 << (int)Entity.getKind() << CurInitExpr->getType()
6291 << CurInitExpr->getSourceRange();
6292 S.NoteDeletedFunction(Best->Function);
6293 return ExprError();
6294 }
6295
6296 bool HadMultipleCandidates = CandidateSet.size() > 1;
6297
6298 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
6299 SmallVector<Expr*, 8> ConstructorArgs;
6300 CurInit.get(); // Ownership transferred into MultiExprArg, below.
6301
6302 S.CheckConstructorAccess(Loc, Constructor, Best->FoundDecl, Entity,
6303 IsExtraneousCopy);
6304
6305 if (IsExtraneousCopy) {
6306 // If this is a totally extraneous copy for C++03 reference
6307 // binding purposes, just return the original initialization
6308 // expression. We don't generate an (elided) copy operation here
6309 // because doing so would require us to pass down a flag to avoid
6310 // infinite recursion, where each step adds another extraneous,
6311 // elidable copy.
6312
6313 // Instantiate the default arguments of any extra parameters in
6314 // the selected copy constructor, as if we were going to create a
6315 // proper call to the copy constructor.
6316 for (unsigned I = 1, N = Constructor->getNumParams(); I != N; ++I) {
6317 ParmVarDecl *Parm = Constructor->getParamDecl(I);
6318 if (S.RequireCompleteType(Loc, Parm->getType(),
6319 diag::err_call_incomplete_argument))
6320 break;
6321
6322 // Build the default argument expression; we don't actually care
6323 // if this succeeds or not, because this routine will complain
6324 // if there was a problem.
6325 S.BuildCXXDefaultArgExpr(Loc, Constructor, Parm);
6326 }
6327
6328 return CurInitExpr;
6329 }
6330
6331 // Determine the arguments required to actually perform the
6332 // constructor call (we might have derived-to-base conversions, or
6333 // the copy constructor may have default arguments).
6334 if (S.CompleteConstructorCall(Constructor, T, CurInitExpr, Loc,
6335 ConstructorArgs))
6336 return ExprError();
6337
6338 // C++0x [class.copy]p32:
6339 // When certain criteria are met, an implementation is allowed to
6340 // omit the copy/move construction of a class object, even if the
6341 // copy/move constructor and/or destructor for the object have
6342 // side effects. [...]
6343 // - when a temporary class object that has not been bound to a
6344 // reference (12.2) would be copied/moved to a class object
6345 // with the same cv-unqualified type, the copy/move operation
6346 // can be omitted by constructing the temporary object
6347 // directly into the target of the omitted copy/move
6348 //
6349 // Note that the other three bullets are handled elsewhere. Copy
6350 // elision for return statements and throw expressions are handled as part
6351 // of constructor initialization, while copy elision for exception handlers
6352 // is handled by the run-time.
6353 //
6354 // FIXME: If the function parameter is not the same type as the temporary, we
6355 // should still be able to elide the copy, but we don't have a way to
6356 // represent in the AST how much should be elided in this case.
6357 bool Elidable =
6358 CurInitExpr->isTemporaryObject(S.Context, Class) &&
6359 S.Context.hasSameUnqualifiedType(
6360 Best->Function->getParamDecl(0)->getType().getNonReferenceType(),
6361 CurInitExpr->getType());
6362
6363 // Actually perform the constructor call.
6364 CurInit = S.BuildCXXConstructExpr(Loc, T, Best->FoundDecl, Constructor,
6365 Elidable,
6366 ConstructorArgs,
6367 HadMultipleCandidates,
6368 /*ListInit*/ false,
6369 /*StdInitListInit*/ false,
6370 /*ZeroInit*/ false,
6371 CXXConstructExpr::CK_Complete,
6372 SourceRange());
6373
6374 // If we're supposed to bind temporaries, do so.
6375 if (!CurInit.isInvalid() && shouldBindAsTemporary(Entity))
6376 CurInit = S.MaybeBindToTemporary(CurInit.getAs<Expr>());
6377 return CurInit;
6378}
6379
6380/// Check whether elidable copy construction for binding a reference to
6381/// a temporary would have succeeded if we were building in C++98 mode, for
6382/// -Wc++98-compat.
6383static void CheckCXX98CompatAccessibleCopy(Sema &S,
6384 const InitializedEntity &Entity,
6385 Expr *CurInitExpr) {
6386 assert(S.getLangOpts().CPlusPlus11)((void)0);
6387
6388 const RecordType *Record = CurInitExpr->getType()->getAs<RecordType>();
6389 if (!Record)
6390 return;
6391
6392 SourceLocation Loc = getInitializationLoc(Entity, CurInitExpr);
6393 if (S.Diags.isIgnored(diag::warn_cxx98_compat_temp_copy, Loc))
6394 return;
6395
6396 // Find constructors which would have been considered.
6397 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
6398 DeclContext::lookup_result Ctors =
6399 S.LookupConstructors(cast<CXXRecordDecl>(Record->getDecl()));
6400
6401 // Perform overload resolution.
6402 OverloadCandidateSet::iterator Best;
6403 OverloadingResult OR = ResolveConstructorOverload(
6404 S, Loc, CurInitExpr, CandidateSet, CurInitExpr->getType(), Ctors, Best,
6405 /*CopyInitializing=*/false, /*AllowExplicit=*/true,
6406 /*OnlyListConstructors=*/false, /*IsListInit=*/false,
6407 /*SecondStepOfCopyInit=*/true);
6408
6409 PartialDiagnostic Diag = S.PDiag(diag::warn_cxx98_compat_temp_copy)
6410 << OR << (int)Entity.getKind() << CurInitExpr->getType()
6411 << CurInitExpr->getSourceRange();
6412
6413 switch (OR) {
6414 case OR_Success:
6415 S.CheckConstructorAccess(Loc, cast<CXXConstructorDecl>(Best->Function),
6416 Best->FoundDecl, Entity, Diag);
6417 // FIXME: Check default arguments as far as that's possible.
6418 break;
6419
6420 case OR_No_Viable_Function:
6421 CandidateSet.NoteCandidates(PartialDiagnosticAt(Loc, Diag), S,
6422 OCD_AllCandidates, CurInitExpr);
6423 break;
6424
6425 case OR_Ambiguous:
6426 CandidateSet.NoteCandidates(PartialDiagnosticAt(Loc, Diag), S,
6427 OCD_AmbiguousCandidates, CurInitExpr);
6428 break;
6429
6430 case OR_Deleted:
6431 S.Diag(Loc, Diag);
6432 S.NoteDeletedFunction(Best->Function);
6433 break;
6434 }
6435}
6436
6437void InitializationSequence::PrintInitLocationNote(Sema &S,
6438 const InitializedEntity &Entity) {
6439 if (Entity.isParamOrTemplateParamKind() && Entity.getDecl()) {
6440 if (Entity.getDecl()->getLocation().isInvalid())
6441 return;
6442
6443 if (Entity.getDecl()->getDeclName())
6444 S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_named_here)
6445 << Entity.getDecl()->getDeclName();
6446 else
6447 S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_here);
6448 }
6449 else if (Entity.getKind() == InitializedEntity::EK_RelatedResult &&
6450 Entity.getMethodDecl())
6451 S.Diag(Entity.getMethodDecl()->getLocation(),
6452 diag::note_method_return_type_change)
6453 << Entity.getMethodDecl()->getDeclName();
6454}
6455
6456/// Returns true if the parameters describe a constructor initialization of
6457/// an explicit temporary object, e.g. "Point(x, y)".
6458static bool isExplicitTemporary(const InitializedEntity &Entity,
6459 const InitializationKind &Kind,
6460 unsigned NumArgs) {
6461 switch (Entity.getKind()) {
6462 case InitializedEntity::EK_Temporary:
6463 case InitializedEntity::EK_CompoundLiteralInit:
6464 case InitializedEntity::EK_RelatedResult:
6465 break;
6466 default:
6467 return false;
6468 }
6469
6470 switch (Kind.getKind()) {
6471 case InitializationKind::IK_DirectList:
6472 return true;
6473 // FIXME: Hack to work around cast weirdness.
6474 case InitializationKind::IK_Direct:
6475 case InitializationKind::IK_Value:
6476 return NumArgs != 1;
6477 default:
6478 return false;
6479 }
6480}
6481
6482static ExprResult
6483PerformConstructorInitialization(Sema &S,
6484 const InitializedEntity &Entity,
6485 const InitializationKind &Kind,
6486 MultiExprArg Args,
6487 const InitializationSequence::Step& Step,
6488 bool &ConstructorInitRequiresZeroInit,
6489 bool IsListInitialization,
6490 bool IsStdInitListInitialization,
6491 SourceLocation LBraceLoc,
6492 SourceLocation RBraceLoc) {
6493 unsigned NumArgs = Args.size();
6494 CXXConstructorDecl *Constructor
6495 = cast<CXXConstructorDecl>(Step.Function.Function);
25
←
Field 'Function' is a 'CXXConstructorDecl'
→
6496 bool HadMultipleCandidates = Step.Function.HadMultipleCandidates;
6497
6498 // Build a call to the selected constructor.
6499 SmallVector<Expr*, 8> ConstructorArgs;
6500 SourceLocation Loc = (Kind.isCopyInit() && Kind.getEqualLoc().isValid())
6501 ? Kind.getEqualLoc()
6502 : Kind.getLocation();
6503
6504 if (Kind.getKind() == InitializationKind::IK_Default) {
26
←
Assuming the condition is false
→
27
←
Taking false branch
→
6505 // Force even a trivial, implicit default constructor to be
6506 // semantically checked. We do this explicitly because we don't build
6507 // the definition for completely trivial constructors.
6508 assert(Constructor->getParent() && "No parent class for constructor.")((void)0);
6509 if (Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&
6510 Constructor->isTrivial() && !Constructor->isUsed(false)) {
6511 S.runWithSufficientStackSpace(Loc, [&] {
6512 S.DefineImplicitDefaultConstructor(Loc, Constructor);
6513 });
6514 }
6515 }
6516
6517 ExprResult CurInit((Expr *)nullptr);
6518
6519 // C++ [over.match.copy]p1:
6520 // - When initializing a temporary to be bound to the first parameter
6521 // of a constructor that takes a reference to possibly cv-qualified
6522 // T as its first argument, called with a single argument in the
6523 // context of direct-initialization, explicit conversion functions
6524 // are also considered.
6525 bool AllowExplicitConv =
6526 Kind.AllowExplicit() && !Kind.isCopyInit() && Args.size() == 1 &&
28
←
Assuming the condition is true
→
6527 hasCopyOrMoveCtorParam(S.Context,
37
←
Calling 'hasCopyOrMoveCtorParam'
→
6528 getConstructorInfo(Step.Function.FoundDecl));
29
←
Calling 'getConstructorInfo'
→
36
←
Returning from 'getConstructorInfo'
→
6529
6530 // Determine the arguments required to actually perform the constructor
6531 // call.
6532 if (S.CompleteConstructorCall(Constructor, Step.Type, Args, Loc,
6533 ConstructorArgs, AllowExplicitConv,
6534 IsListInitialization))
6535 return ExprError();
6536
6537 if (isExplicitTemporary(Entity, Kind, NumArgs)) {
6538 // An explicitly-constructed temporary, e.g., X(1, 2).
6539 if (S.DiagnoseUseOfDecl(Constructor, Loc))
6540 return ExprError();
6541
6542 TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo();
6543 if (!TSInfo)
6544 TSInfo = S.Context.getTrivialTypeSourceInfo(Entity.getType(), Loc);
6545 SourceRange ParenOrBraceRange =
6546 (Kind.getKind() == InitializationKind::IK_DirectList)
6547 ? SourceRange(LBraceLoc, RBraceLoc)
6548 : Kind.getParenOrBraceRange();
6549
6550 CXXConstructorDecl *CalleeDecl = Constructor;
6551 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(
6552 Step.Function.FoundDecl.getDecl())) {
6553 CalleeDecl = S.findInheritingConstructor(Loc, Constructor, Shadow);
6554 if (S.DiagnoseUseOfDecl(CalleeDecl, Loc))
6555 return ExprError();
6556 }
6557 S.MarkFunctionReferenced(Loc, CalleeDecl);
6558
6559 CurInit = S.CheckForImmediateInvocation(
6560 CXXTemporaryObjectExpr::Create(
6561 S.Context, CalleeDecl,
6562 Entity.getType().getNonLValueExprType(S.Context), TSInfo,
6563 ConstructorArgs, ParenOrBraceRange, HadMultipleCandidates,
6564 IsListInitialization, IsStdInitListInitialization,
6565 ConstructorInitRequiresZeroInit),
6566 CalleeDecl);
6567 } else {
6568 CXXConstructExpr::ConstructionKind ConstructKind =
6569 CXXConstructExpr::CK_Complete;
6570
6571 if (Entity.getKind() == InitializedEntity::EK_Base) {
6572 ConstructKind = Entity.getBaseSpecifier()->isVirtual() ?
6573 CXXConstructExpr::CK_VirtualBase :
6574 CXXConstructExpr::CK_NonVirtualBase;
6575 } else if (Entity.getKind() == InitializedEntity::EK_Delegating) {
6576 ConstructKind = CXXConstructExpr::CK_Delegating;
6577 }
6578
6579 // Only get the parenthesis or brace range if it is a list initialization or
6580 // direct construction.
6581 SourceRange ParenOrBraceRange;
6582 if (IsListInitialization)
6583 ParenOrBraceRange = SourceRange(LBraceLoc, RBraceLoc);
6584 else if (Kind.getKind() == InitializationKind::IK_Direct)
6585 ParenOrBraceRange = Kind.getParenOrBraceRange();
6586
6587 // If the entity allows NRVO, mark the construction as elidable
6588 // unconditionally.
6589 if (Entity.allowsNRVO())
6590 CurInit = S.BuildCXXConstructExpr(Loc, Step.Type,
6591 Step.Function.FoundDecl,
6592 Constructor, /*Elidable=*/true,
6593 ConstructorArgs,
6594 HadMultipleCandidates,
6595 IsListInitialization,
6596 IsStdInitListInitialization,
6597 ConstructorInitRequiresZeroInit,
6598 ConstructKind,
6599 ParenOrBraceRange);
6600 else
6601 CurInit = S.BuildCXXConstructExpr(Loc, Step.Type,
6602 Step.Function.FoundDecl,
6603 Constructor,
6604 ConstructorArgs,
6605 HadMultipleCandidates,
6606 IsListInitialization,
6607 IsStdInitListInitialization,
6608 ConstructorInitRequiresZeroInit,
6609 ConstructKind,
6610 ParenOrBraceRange);
6611 }
6612 if (CurInit.isInvalid())
6613 return ExprError();
6614
6615 // Only check access if all of that succeeded.
6616 S.CheckConstructorAccess(Loc, Constructor, Step.Function.FoundDecl, Entity);
6617 if (S.DiagnoseUseOfDecl(Step.Function.FoundDecl, Loc))
6618 return ExprError();
6619
6620 if (const ArrayType *AT = S.Context.getAsArrayType(Entity.getType()))
6621 if (checkDestructorReference(S.Context.getBaseElementType(AT), Loc, S))
6622 return ExprError();
6623
6624 if (shouldBindAsTemporary(Entity))
6625 CurInit = S.MaybeBindToTemporary(CurInit.get());
6626
6627 return CurInit;
6628}
6629
6630namespace {
6631enum LifetimeKind {
6632 /// The lifetime of a temporary bound to this entity ends at the end of the
6633 /// full-expression, and that's (probably) fine.
6634 LK_FullExpression,
6635
6636 /// The lifetime of a temporary bound to this entity is extended to the
6637 /// lifeitme of the entity itself.
6638 LK_Extended,
6639
6640 /// The lifetime of a temporary bound to this entity probably ends too soon,
6641 /// because the entity is allocated in a new-expression.
6642 LK_New,
6643
6644 /// The lifetime of a temporary bound to this entity ends too soon, because
6645 /// the entity is a return object.
6646 LK_Return,
6647
6648 /// The lifetime of a temporary bound to this entity ends too soon, because
6649 /// the entity is the result of a statement expression.
6650 LK_StmtExprResult,
6651
6652 /// This is a mem-initializer: if it would extend a temporary (other than via
6653 /// a default member initializer), the program is ill-formed.
6654 LK_MemInitializer,
6655};
6656using LifetimeResult =
6657 llvm::PointerIntPair<const InitializedEntity *, 3, LifetimeKind>;
6658}
6659
6660/// Determine the declaration which an initialized entity ultimately refers to,
6661/// for the purpose of lifetime-extending a temporary bound to a reference in
6662/// the initialization of \p Entity.
6663static LifetimeResult getEntityLifetime(
6664 const InitializedEntity *Entity,
6665 const InitializedEntity *InitField = nullptr) {
6666 // C++11 [class.temporary]p5:
6667 switch (Entity->getKind()) {
6668 case InitializedEntity::EK_Variable:
6669 // The temporary [...] persists for the lifetime of the reference
6670 return {Entity, LK_Extended};
6671
6672 case InitializedEntity::EK_Member:
6673 // For subobjects, we look at the complete object.
6674 if (Entity->getParent())
6675 return getEntityLifetime(Entity->getParent(), Entity);
6676
6677 // except:
6678 // C++17 [class.base.init]p8:
6679 // A temporary expression bound to a reference member in a
6680 // mem-initializer is ill-formed.
6681 // C++17 [class.base.init]p11:
6682 // A temporary expression bound to a reference member from a
6683 // default member initializer is ill-formed.
6684 //
6685 // The context of p11 and its example suggest that it's only the use of a
6686 // default member initializer from a constructor that makes the program
6687 // ill-formed, not its mere existence, and that it can even be used by
6688 // aggregate initialization.
6689 return {Entity, Entity->isDefaultMemberInitializer() ? LK_Extended
6690 : LK_MemInitializer};
6691
6692 case InitializedEntity::EK_Binding:
6693 // Per [dcl.decomp]p3, the binding is treated as a variable of reference
6694 // type.
6695 return {Entity, LK_Extended};
6696
6697 case InitializedEntity::EK_Parameter:
6698 case InitializedEntity::EK_Parameter_CF_Audited:
6699 // -- A temporary bound to a reference parameter in a function call
6700 // persists until the completion of the full-expression containing
6701 // the call.
6702 return {nullptr, LK_FullExpression};
6703
6704 case InitializedEntity::EK_TemplateParameter:
6705 // FIXME: This will always be ill-formed; should we eagerly diagnose it here?
6706 return {nullptr, LK_FullExpression};
6707
6708 case InitializedEntity::EK_Result:
6709 // -- The lifetime of a temporary bound to the returned value in a
6710 // function return statement is not extended; the temporary is
6711 // destroyed at the end of the full-expression in the return statement.
6712 return {nullptr, LK_Return};
6713
6714 case InitializedEntity::EK_StmtExprResult:
6715 // FIXME: Should we lifetime-extend through the result of a statement
6716 // expression?
6717 return {nullptr, LK_StmtExprResult};
6718
6719 case InitializedEntity::EK_New:
6720 // -- A temporary bound to a reference in a new-initializer persists
6721 // until the completion of the full-expression containing the
6722 // new-initializer.
6723 return {nullptr, LK_New};
6724
6725 case InitializedEntity::EK_Temporary:
6726 case InitializedEntity::EK_CompoundLiteralInit:
6727 case InitializedEntity::EK_RelatedResult:
6728 // We don't yet know the storage duration of the surrounding temporary.
6729 // Assume it's got full-expression duration for now, it will patch up our
6730 // storage duration if that's not correct.
6731 return {nullptr, LK_FullExpression};
6732
6733 case InitializedEntity::EK_ArrayElement:
6734 // For subobjects, we look at the complete object.
6735 return getEntityLifetime(Entity->getParent(), InitField);
6736
6737 case InitializedEntity::EK_Base:
6738 // For subobjects, we look at the complete object.
6739 if (Entity->getParent())
6740 return getEntityLifetime(Entity->getParent(), InitField);
6741 return {InitField, LK_MemInitializer};
6742
6743 case InitializedEntity::EK_Delegating:
6744 // We can reach this case for aggregate initialization in a constructor:
6745 // struct A { int &&r; };
6746 // struct B : A { B() : A{0} {} };
6747 // In this case, use the outermost field decl as the context.
6748 return {InitField, LK_MemInitializer};
6749
6750 case InitializedEntity::EK_BlockElement:
6751 case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
6752 case InitializedEntity::EK_LambdaCapture:
6753 case InitializedEntity::EK_VectorElement:
6754 case InitializedEntity::EK_ComplexElement:
6755 return {nullptr, LK_FullExpression};
6756
6757 case InitializedEntity::EK_Exception:
6758 // FIXME: Can we diagnose lifetime problems with exceptions?
6759 return {nullptr, LK_FullExpression};
6760 }
6761 llvm_unreachable("unknown entity kind")__builtin_unreachable();
6762}
6763
6764namespace {
6765enum ReferenceKind {
6766 /// Lifetime would be extended by a reference binding to a temporary.
6767 RK_ReferenceBinding,
6768 /// Lifetime would be extended by a std::initializer_list object binding to
6769 /// its backing array.
6770 RK_StdInitializerList,
6771};
6772
6773/// A temporary or local variable. This will be one of:
6774/// * A MaterializeTemporaryExpr.
6775/// * A DeclRefExpr whose declaration is a local.
6776/// * An AddrLabelExpr.
6777/// * A BlockExpr for a block with captures.
6778using Local = Expr*;
6779
6780/// Expressions we stepped over when looking for the local state. Any steps
6781/// that would inhibit lifetime extension or take us out of subexpressions of
6782/// the initializer are included.
6783struct IndirectLocalPathEntry {
6784 enum EntryKind {
6785 DefaultInit,
6786 AddressOf,
6787 VarInit,
6788 LValToRVal,
6789 LifetimeBoundCall,
6790 TemporaryCopy,
6791 LambdaCaptureInit,
6792 GslReferenceInit,
6793 GslPointerInit
6794 } Kind;
6795 Expr *E;
6796 union {
6797 const Decl *D = nullptr;
6798 const LambdaCapture *Capture;
6799 };
6800 IndirectLocalPathEntry() {}
6801 IndirectLocalPathEntry(EntryKind K, Expr *E) : Kind(K), E(E) {}
6802 IndirectLocalPathEntry(EntryKind K, Expr *E, const Decl *D)
6803 : Kind(K), E(E), D(D) {}
6804 IndirectLocalPathEntry(EntryKind K, Expr *E, const LambdaCapture *Capture)
6805 : Kind(K), E(E), Capture(Capture) {}
6806};
6807
6808using IndirectLocalPath = llvm::SmallVectorImpl<IndirectLocalPathEntry>;
6809
6810struct RevertToOldSizeRAII {
6811 IndirectLocalPath &Path;
6812 unsigned OldSize = Path.size();
6813 RevertToOldSizeRAII(IndirectLocalPath &Path) : Path(Path) {}
6814 ~RevertToOldSizeRAII() { Path.resize(OldSize); }
6815};
6816
6817using LocalVisitor = llvm::function_ref<bool(IndirectLocalPath &Path, Local L,
6818 ReferenceKind RK)>;
6819}
6820
6821static bool isVarOnPath(IndirectLocalPath &Path, VarDecl *VD) {
6822 for (auto E : Path)
6823 if (E.Kind == IndirectLocalPathEntry::VarInit && E.D == VD)
6824 return true;
6825 return false;
6826}
6827
6828static bool pathContainsInit(IndirectLocalPath &Path) {
6829 return llvm::any_of(Path, [=](IndirectLocalPathEntry E) {
6830 return E.Kind == IndirectLocalPathEntry::DefaultInit ||
6831 E.Kind == IndirectLocalPathEntry::VarInit;
6832 });
6833}
6834
6835static void visitLocalsRetainedByInitializer(IndirectLocalPath &Path,
6836 Expr *Init, LocalVisitor Visit,
6837 bool RevisitSubinits,
6838 bool EnableLifetimeWarnings);
6839
6840static void visitLocalsRetainedByReferenceBinding(IndirectLocalPath &Path,
6841 Expr *Init, ReferenceKind RK,
6842 LocalVisitor Visit,
6843 bool EnableLifetimeWarnings);
6844
6845template <typename T> static bool isRecordWithAttr(QualType Type) {
6846 if (auto *RD = Type->getAsCXXRecordDecl())
6847 return RD->hasAttr<T>();
6848 return false;
6849}
6850
6851// Decl::isInStdNamespace will return false for iterators in some STL
6852// implementations due to them being defined in a namespace outside of the std
6853// namespace.
6854static bool isInStlNamespace(const Decl *D) {
6855 const DeclContext *DC = D->getDeclContext();
6856 if (!DC)
6857 return false;
6858 if (const auto *ND = dyn_cast<NamespaceDecl>(DC))
6859 if (const IdentifierInfo *II = ND->getIdentifier()) {
6860 StringRef Name = II->getName();
6861 if (Name.size() >= 2 && Name.front() == '_' &&
6862 (Name[1] == '_' || isUppercase(Name[1])))
6863 return true;
6864 }
6865
6866 return DC->isStdNamespace();
6867}
6868
6869static bool shouldTrackImplicitObjectArg(const CXXMethodDecl *Callee) {
6870 if (auto *Conv = dyn_cast_or_null<CXXConversionDecl>(Callee))
6871 if (isRecordWithAttr<PointerAttr>(Conv->getConversionType()))
6872 return true;
6873 if (!isInStlNamespace(Callee->getParent()))
6874 return false;
6875 if (!isRecordWithAttr<PointerAttr>(Callee->getThisObjectType()) &&
6876 !isRecordWithAttr<OwnerAttr>(Callee->getThisObjectType()))
6877 return false;
6878 if (Callee->getReturnType()->isPointerType() ||
6879 isRecordWithAttr<PointerAttr>(Callee->getReturnType())) {
6880 if (!Callee->getIdentifier())
6881 return false;
6882 return llvm::StringSwitch<bool>(Callee->getName())
6883 .Cases("begin", "rbegin", "cbegin", "crbegin", true)
6884 .Cases("end", "rend", "cend", "crend", true)
6885 .Cases("c_str", "data", "get", true)
6886 // Map and set types.
6887 .Cases("find", "equal_range", "lower_bound", "upper_bound", true)
6888 .Default(false);
6889 } else if (Callee->getReturnType()->isReferenceType()) {
6890 if (!Callee->getIdentifier()) {
6891 auto OO = Callee->getOverloadedOperator();
6892 return OO == OverloadedOperatorKind::OO_Subscript ||
6893 OO == OverloadedOperatorKind::OO_Star;
6894 }
6895 return llvm::StringSwitch<bool>(Callee->getName())
6896 .Cases("front", "back", "at", "top", "value", true)
6897 .Default(false);
6898 }
6899 return false;
6900}
6901
6902static bool shouldTrackFirstArgument(const FunctionDecl *FD) {
6903 if (!FD->getIdentifier() || FD->getNumParams() != 1)
6904 return false;
6905 const auto *RD = FD->getParamDecl(0)->getType()->getPointeeCXXRecordDecl();
6906 if (!FD->isInStdNamespace() || !RD || !RD->isInStdNamespace())
6907 return false;
6908 if (!isRecordWithAttr<PointerAttr>(QualType(RD->getTypeForDecl(), 0)) &&
6909 !isRecordWithAttr<OwnerAttr>(QualType(RD->getTypeForDecl(), 0)))
6910 return false;
6911 if (FD->getReturnType()->isPointerType() ||
6912 isRecordWithAttr<PointerAttr>(FD->getReturnType())) {
6913 return llvm::StringSwitch<bool>(FD->getName())
6914 .Cases("begin", "rbegin", "cbegin", "crbegin", true)
6915 .Cases("end", "rend", "cend", "crend", true)
6916 .Case("data", true)
6917 .Default(false);
6918 } else if (FD->getReturnType()->isReferenceType()) {
6919 return llvm::StringSwitch<bool>(FD->getName())
6920 .Cases("get", "any_cast", true)
6921 .Default(false);
6922 }
6923 return false;
6924}
6925
6926static void handleGslAnnotatedTypes(IndirectLocalPath &Path, Expr *Call,
6927 LocalVisitor Visit) {
6928 auto VisitPointerArg = [&](const Decl *D, Expr *Arg, bool Value) {
6929 // We are not interested in the temporary base objects of gsl Pointers:
6930 // Temp().ptr; // Here ptr might not dangle.
6931 if (isa<MemberExpr>(Arg->IgnoreImpCasts()))
6932 return;
6933 // Once we initialized a value with a reference, it can no longer dangle.
6934 if (!Value) {
6935 for (auto It = Path.rbegin(), End = Path.rend(); It != End; ++It) {
6936 if (It->Kind == IndirectLocalPathEntry::GslReferenceInit)
6937 continue;
6938 if (It->Kind == IndirectLocalPathEntry::GslPointerInit)
6939 return;
6940 break;
6941 }
6942 }
6943 Path.push_back({Value ? IndirectLocalPathEntry::GslPointerInit
6944 : IndirectLocalPathEntry::GslReferenceInit,
6945 Arg, D});
6946 if (Arg->isGLValue())
6947 visitLocalsRetainedByReferenceBinding(Path, Arg, RK_ReferenceBinding,
6948 Visit,
6949 /*EnableLifetimeWarnings=*/true);
6950 else
6951 visitLocalsRetainedByInitializer(Path, Arg, Visit, true,
6952 /*EnableLifetimeWarnings=*/true);
6953 Path.pop_back();
6954 };
6955
6956 if (auto *MCE = dyn_cast<CXXMemberCallExpr>(Call)) {
6957 const auto *MD = cast_or_null<CXXMethodDecl>(MCE->getDirectCallee());
6958 if (MD && shouldTrackImplicitObjectArg(MD))
6959 VisitPointerArg(MD, MCE->getImplicitObjectArgument(),
6960 !MD->getReturnType()->isReferenceType());
6961 return;
6962 } else if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(Call)) {
6963 FunctionDecl *Callee = OCE->getDirectCallee();
6964 if (Callee && Callee->isCXXInstanceMember() &&
6965 shouldTrackImplicitObjectArg(cast<CXXMethodDecl>(Callee)))
6966 VisitPointerArg(Callee, OCE->getArg(0),
6967 !Callee->getReturnType()->isReferenceType());
6968 return;
6969 } else if (auto *CE = dyn_cast<CallExpr>(Call)) {
6970 FunctionDecl *Callee = CE->getDirectCallee();
6971 if (Callee && shouldTrackFirstArgument(Callee))
6972 VisitPointerArg(Callee, CE->getArg(0),
6973 !Callee->getReturnType()->isReferenceType());
6974 return;
6975 }
6976
6977 if (auto *CCE = dyn_cast<CXXConstructExpr>(Call)) {
6978 const auto *Ctor = CCE->getConstructor();
6979 const CXXRecordDecl *RD = Ctor->getParent();
6980 if (CCE->getNumArgs() > 0 && RD->hasAttr<PointerAttr>())
6981 VisitPointerArg(Ctor->getParamDecl(0), CCE->getArgs()[0], true);
6982 }
6983}
6984
6985static bool implicitObjectParamIsLifetimeBound(const FunctionDecl *FD) {
6986 const TypeSourceInfo *TSI = FD->getTypeSourceInfo();
6987 if (!TSI)
6988 return false;
6989 // Don't declare this variable in the second operand of the for-statement;
6990 // GCC miscompiles that by ending its lifetime before evaluating the
6991 // third operand. See gcc.gnu.org/PR86769.
6992 AttributedTypeLoc ATL;
6993 for (TypeLoc TL = TSI->getTypeLoc();
6994 (ATL = TL.getAsAdjusted<AttributedTypeLoc>());
6995 TL = ATL.getModifiedLoc()) {
6996 if (ATL.getAttrAs<LifetimeBoundAttr>())
6997 return true;
6998 }
6999
7000 // Assume that all assignment operators with a "normal" return type return
7001 // *this, that is, an lvalue reference that is the same type as the implicit
7002 // object parameter (or the LHS for a non-member operator$=).
7003 OverloadedOperatorKind OO = FD->getDeclName().getCXXOverloadedOperator();
7004 if (OO == OO_Equal || isCompoundAssignmentOperator(OO)) {
7005 QualType RetT = FD->getReturnType();
7006 if (RetT->isLValueReferenceType()) {
7007 ASTContext &Ctx = FD->getASTContext();
7008 QualType LHST;
7009 auto *MD = dyn_cast<CXXMethodDecl>(FD);
7010 if (MD && MD->isCXXInstanceMember())
7011 LHST = Ctx.getLValueReferenceType(MD->getThisObjectType());
7012 else
7013 LHST = MD->getParamDecl(0)->getType();
7014 if (Ctx.hasSameType(RetT, LHST))
7015 return true;
7016 }
7017 }
7018
7019 return false;
7020}
7021
7022static void visitLifetimeBoundArguments(IndirectLocalPath &Path, Expr *Call,
7023 LocalVisitor Visit) {
7024 const FunctionDecl *Callee;
7025 ArrayRef<Expr*> Args;
7026
7027 if (auto *CE = dyn_cast<CallExpr>(Call)) {
7028 Callee = CE->getDirectCallee();
7029 Args = llvm::makeArrayRef(CE->getArgs(), CE->getNumArgs());
7030 } else {
7031 auto *CCE = cast<CXXConstructExpr>(Call);
7032 Callee = CCE->getConstructor();
7033 Args = llvm::makeArrayRef(CCE->getArgs(), CCE->getNumArgs());
7034 }
7035 if (!Callee)
7036 return;
7037
7038 Expr *ObjectArg = nullptr;
7039 if (isa<CXXOperatorCallExpr>(Call) && Callee->isCXXInstanceMember()) {
7040 ObjectArg = Args[0];
7041 Args = Args.slice(1);
7042 } else if (auto *MCE = dyn_cast<CXXMemberCallExpr>(Call)) {
7043 ObjectArg = MCE->getImplicitObjectArgument();
7044 }
7045
7046 auto VisitLifetimeBoundArg = [&](const Decl *D, Expr *Arg) {
7047 Path.push_back({IndirectLocalPathEntry::LifetimeBoundCall, Arg, D});
7048 if (Arg->isGLValue())
7049 visitLocalsRetainedByReferenceBinding(Path, Arg, RK_ReferenceBinding,
7050 Visit,
7051 /*EnableLifetimeWarnings=*/false);
7052 else
7053 visitLocalsRetainedByInitializer(Path, Arg, Visit, true,
7054 /*EnableLifetimeWarnings=*/false);
7055 Path.pop_back();
7056 };
7057
7058 if (ObjectArg && implicitObjectParamIsLifetimeBound(Callee))
7059 VisitLifetimeBoundArg(Callee, ObjectArg);
7060
7061 for (unsigned I = 0,
7062 N = std::min<unsigned>(Callee->getNumParams(), Args.size());
7063 I != N; ++I) {
7064 if (Callee->getParamDecl(I)->hasAttr<LifetimeBoundAttr>())
7065 VisitLifetimeBoundArg(Callee->getParamDecl(I), Args[I]);
7066 }
7067}
7068
7069/// Visit the locals that would be reachable through a reference bound to the
7070/// glvalue expression \c Init.
7071static void visitLocalsRetainedByReferenceBinding(IndirectLocalPath &Path,
7072 Expr *Init, ReferenceKind RK,
7073 LocalVisitor Visit,
7074 bool EnableLifetimeWarnings) {
7075 RevertToOldSizeRAII RAII(Path);
7076
7077 // Walk past any constructs which we can lifetime-extend across.
7078 Expr *Old;
7079 do {
7080 Old = Init;
7081
7082 if (auto *FE = dyn_cast<FullExpr>(Init))
7083 Init = FE->getSubExpr();
7084
7085 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
7086 // If this is just redundant braces around an initializer, step over it.
7087 if (ILE->isTransparent())
7088 Init = ILE->getInit(0);
7089 }
7090
7091 // Step over any subobject adjustments; we may have a materialized
7092 // temporary inside them.
7093 Init = const_cast<Expr *>(Init->skipRValueSubobjectAdjustments());
7094
7095 // Per current approach for DR1376, look through casts to reference type
7096 // when performing lifetime extension.
7097 if (CastExpr *CE = dyn_cast<CastExpr>(Init))
7098 if (CE->getSubExpr()->isGLValue())
7099 Init = CE->getSubExpr();
7100
7101 // Per the current approach for DR1299, look through array element access
7102 // on array glvalues when performing lifetime extension.
7103 if (auto *ASE = dyn_cast<ArraySubscriptExpr>(Init)) {
7104 Init = ASE->getBase();
7105 auto *ICE = dyn_cast<ImplicitCastExpr>(Init);
7106 if (ICE && ICE->getCastKind() == CK_ArrayToPointerDecay)
7107 Init = ICE->getSubExpr();
7108 else
7109 // We can't lifetime extend through this but we might still find some
7110 // retained temporaries.
7111 return visitLocalsRetainedByInitializer(Path, Init, Visit, true,
7112 EnableLifetimeWarnings);
7113 }
7114
7115 // Step into CXXDefaultInitExprs so we can diagnose cases where a
7116 // constructor inherits one as an implicit mem-initializer.
7117 if (auto *DIE = dyn_cast<CXXDefaultInitExpr>(Init)) {
7118 Path.push_back(
7119 {IndirectLocalPathEntry::DefaultInit, DIE, DIE->getField()});
7120 Init = DIE->getExpr();
7121 }
7122 } while (Init != Old);
7123
7124 if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(Init)) {
7125 if (Visit(Path, Local(MTE), RK))
7126 visitLocalsRetainedByInitializer(Path, MTE->getSubExpr(), Visit, true,
7127 EnableLifetimeWarnings);
7128 }
7129
7130 if (isa<CallExpr>(Init)) {
7131 if (EnableLifetimeWarnings)
7132 handleGslAnnotatedTypes(Path, Init, Visit);
7133 return visitLifetimeBoundArguments(Path, Init, Visit);
7134 }
7135
7136 switch (Init->getStmtClass()) {
7137 case Stmt::DeclRefExprClass: {
7138 // If we find the name of a local non-reference parameter, we could have a
7139 // lifetime problem.
7140 auto *DRE = cast<DeclRefExpr>(Init);
7141 auto *VD = dyn_cast<VarDecl>(DRE->getDecl());
7142 if (VD && VD->hasLocalStorage() &&
7143 !DRE->refersToEnclosingVariableOrCapture()) {
7144 if (!VD->getType()->isReferenceType()) {
7145 Visit(Path, Local(DRE), RK);
7146 } else if (isa<ParmVarDecl>(DRE->getDecl())) {
7147 // The lifetime of a reference parameter is unknown; assume it's OK
7148 // for now.
7149 break;
7150 } else if (VD->getInit() && !isVarOnPath(Path, VD)) {
7151 Path.push_back({IndirectLocalPathEntry::VarInit, DRE, VD});
7152 visitLocalsRetainedByReferenceBinding(Path, VD->getInit(),
7153 RK_ReferenceBinding, Visit,
7154 EnableLifetimeWarnings);
7155 }
7156 }
7157 break;
7158 }
7159
7160 case Stmt::UnaryOperatorClass: {
7161 // The only unary operator that make sense to handle here
7162 // is Deref. All others don't resolve to a "name." This includes
7163 // handling all sorts of rvalues passed to a unary operator.
7164 const UnaryOperator *U = cast<UnaryOperator>(Init);
7165 if (U->getOpcode() == UO_Deref)
7166 visitLocalsRetainedByInitializer(Path, U->getSubExpr(), Visit, true,
7167 EnableLifetimeWarnings);
7168 break;
7169 }
7170
7171 case Stmt::OMPArraySectionExprClass: {
7172 visitLocalsRetainedByInitializer(Path,
7173 cast<OMPArraySectionExpr>(Init)->getBase(),
7174 Visit, true, EnableLifetimeWarnings);
7175 break;
7176 }
7177
7178 case Stmt::ConditionalOperatorClass:
7179 case Stmt::BinaryConditionalOperatorClass: {
7180 auto *C = cast<AbstractConditionalOperator>(Init);
7181 if (!C->getTrueExpr()->getType()->isVoidType())
7182 visitLocalsRetainedByReferenceBinding(Path, C->getTrueExpr(), RK, Visit,
7183 EnableLifetimeWarnings);
7184 if (!C->getFalseExpr()->getType()->isVoidType())
7185 visitLocalsRetainedByReferenceBinding(Path, C->getFalseExpr(), RK, Visit,
7186 EnableLifetimeWarnings);
7187 break;
7188 }
7189
7190 // FIXME: Visit the left-hand side of an -> or ->*.
7191
7192 default:
7193 break;
7194 }
7195}
7196
7197/// Visit the locals that would be reachable through an object initialized by
7198/// the prvalue expression \c Init.
7199static void visitLocalsRetainedByInitializer(IndirectLocalPath &Path,
7200 Expr *Init, LocalVisitor Visit,
7201 bool RevisitSubinits,
7202 bool EnableLifetimeWarnings) {
7203 RevertToOldSizeRAII RAII(Path);
7204
7205 Expr *Old;
7206 do {
7207 Old = Init;
7208
7209 // Step into CXXDefaultInitExprs so we can diagnose cases where a
7210 // constructor inherits one as an implicit mem-initializer.
7211 if (auto *DIE = dyn_cast<CXXDefaultInitExpr>(Init)) {
7212 Path.push_back({IndirectLocalPathEntry::DefaultInit, DIE, DIE->getField()});
7213 Init = DIE->getExpr();
7214 }
7215
7216 if (auto *FE = dyn_cast<FullExpr>(Init))
7217 Init = FE->getSubExpr();
7218
7219 // Dig out the expression which constructs the extended temporary.
7220 Init = const_cast<Expr *>(Init->skipRValueSubobjectAdjustments());
7221
7222 if (CXXBindTemporaryExpr *BTE = dyn_cast<CXXBindTemporaryExpr>(Init))
7223 Init = BTE->getSubExpr();
7224
7225 Init = Init->IgnoreParens();
7226
7227 // Step over value-preserving rvalue casts.
7228 if (auto *CE = dyn_cast<CastExpr>(Init)) {
7229 switch (CE->getCastKind()) {
7230 case CK_LValueToRValue:
7231 // If we can match the lvalue to a const object, we can look at its
7232 // initializer.
7233 Path.push_back({IndirectLocalPathEntry::LValToRVal, CE});
7234 return visitLocalsRetainedByReferenceBinding(
7235 Path, Init, RK_ReferenceBinding,
7236 [&](IndirectLocalPath &Path, Local L, ReferenceKind RK) -> bool {
7237 if (auto *DRE = dyn_cast<DeclRefExpr>(L)) {
7238 auto *VD = dyn_cast<VarDecl>(DRE->getDecl());
7239 if (VD && VD->getType().isConstQualified() && VD->getInit() &&
7240 !isVarOnPath(Path, VD)) {
7241 Path.push_back({IndirectLocalPathEntry::VarInit, DRE, VD});
7242 visitLocalsRetainedByInitializer(Path, VD->getInit(), Visit, true,
7243 EnableLifetimeWarnings);
7244 }
7245 } else if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(L)) {
7246 if (MTE->getType().isConstQualified())
7247 visitLocalsRetainedByInitializer(Path, MTE->getSubExpr(), Visit,
7248 true, EnableLifetimeWarnings);
7249 }
7250 return false;
7251 }, EnableLifetimeWarnings);
7252
7253 // We assume that objects can be retained by pointers cast to integers,
7254 // but not if the integer is cast to floating-point type or to _Complex.
7255 // We assume that casts to 'bool' do not preserve enough information to
7256 // retain a local object.
7257 case CK_NoOp:
7258 case CK_BitCast:
7259 case CK_BaseToDerived:
7260 case CK_DerivedToBase:
7261 case CK_UncheckedDerivedToBase:
7262 case CK_Dynamic:
7263 case CK_ToUnion:
7264 case CK_UserDefinedConversion:
7265 case CK_ConstructorConversion:
7266 case CK_IntegralToPointer:
7267 case CK_PointerToIntegral:
7268 case CK_VectorSplat:
7269 case CK_IntegralCast:
7270 case CK_CPointerToObjCPointerCast:
7271 case CK_BlockPointerToObjCPointerCast:
7272 case CK_AnyPointerToBlockPointerCast:
7273 case CK_AddressSpaceConversion:
7274 break;
7275
7276 case CK_ArrayToPointerDecay:
7277 // Model array-to-pointer decay as taking the address of the array
7278 // lvalue.
7279 Path.push_back({IndirectLocalPathEntry::AddressOf, CE});
7280 return visitLocalsRetainedByReferenceBinding(Path, CE->getSubExpr(),
7281 RK_ReferenceBinding, Visit,
7282 EnableLifetimeWarnings);
7283
7284 default:
7285 return;
7286 }
7287
7288 Init = CE->getSubExpr();
7289 }
7290 } while (Old != Init);
7291
7292 // C++17 [dcl.init.list]p6:
7293 // initializing an initializer_list object from the array extends the
7294 // lifetime of the array exactly like binding a reference to a temporary.
7295 if (auto *ILE = dyn_cast<CXXStdInitializerListExpr>(Init))
7296 return visitLocalsRetainedByReferenceBinding(Path, ILE->getSubExpr(),
7297 RK_StdInitializerList, Visit,
7298 EnableLifetimeWarnings);
7299
7300 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
7301 // We already visited the elements of this initializer list while
7302 // performing the initialization. Don't visit them again unless we've
7303 // changed the lifetime of the initialized entity.
7304 if (!RevisitSubinits)
7305 return;
7306
7307 if (ILE->isTransparent())
7308 return visitLocalsRetainedByInitializer(Path, ILE->getInit(0), Visit,
7309 RevisitSubinits,
7310 EnableLifetimeWarnings);
7311
7312 if (ILE->getType()->isArrayType()) {
7313 for (unsigned I = 0, N = ILE->getNumInits(); I != N; ++I)
7314 visitLocalsRetainedByInitializer(Path, ILE->getInit(I), Visit,
7315 RevisitSubinits,
7316 EnableLifetimeWarnings);
7317 return;
7318 }
7319
7320 if (CXXRecordDecl *RD = ILE->getType()->getAsCXXRecordDecl()) {
7321 assert(RD->isAggregate() && "aggregate init on non-aggregate")((void)0);
7322
7323 // If we lifetime-extend a braced initializer which is initializing an
7324 // aggregate, and that aggregate contains reference members which are
7325 // bound to temporaries, those temporaries are also lifetime-extended.
7326 if (RD->isUnion() && ILE->getInitializedFieldInUnion() &&
7327 ILE->getInitializedFieldInUnion()->getType()->isReferenceType())
7328 visitLocalsRetainedByReferenceBinding(Path, ILE->getInit(0),
7329 RK_ReferenceBinding, Visit,
7330 EnableLifetimeWarnings);
7331 else {
7332 unsigned Index = 0;
7333 for (; Index < RD->getNumBases() && Index < ILE->getNumInits(); ++Index)
7334 visitLocalsRetainedByInitializer(Path, ILE->getInit(Index), Visit,
7335 RevisitSubinits,
7336 EnableLifetimeWarnings);
7337 for (const auto *I : RD->fields()) {
7338 if (Index >= ILE->getNumInits())
7339 break;
7340 if (I->isUnnamedBitfield())
7341 continue;
7342 Expr *SubInit = ILE->getInit(Index);
7343 if (I->getType()->isReferenceType())
7344 visitLocalsRetainedByReferenceBinding(Path, SubInit,
7345 RK_ReferenceBinding, Visit,
7346 EnableLifetimeWarnings);
7347 else
7348 // This might be either aggregate-initialization of a member or
7349 // initialization of a std::initializer_list object. Regardless,
7350 // we should recursively lifetime-extend that initializer.
7351 visitLocalsRetainedByInitializer(Path, SubInit, Visit,
7352 RevisitSubinits,
7353 EnableLifetimeWarnings);
7354 ++Index;
7355 }
7356 }
7357 }
7358 return;
7359 }
7360
7361 // The lifetime of an init-capture is that of the closure object constructed
7362 // by a lambda-expression.
7363 if (auto *LE = dyn_cast<LambdaExpr>(Init)) {
7364 LambdaExpr::capture_iterator CapI = LE->capture_begin();
7365 for (Expr *E : LE->capture_inits()) {
7366 assert(CapI != LE->capture_end())((void)0);
7367 const LambdaCapture &Cap = *CapI++;
7368 if (!E)
7369 continue;
7370 if (Cap.capturesVariable())
7371 Path.push_back({IndirectLocalPathEntry::LambdaCaptureInit, E, &Cap});
7372 if (E->isGLValue())
7373 visitLocalsRetainedByReferenceBinding(Path, E, RK_ReferenceBinding,
7374 Visit, EnableLifetimeWarnings);
7375 else
7376 visitLocalsRetainedByInitializer(Path, E, Visit, true,
7377 EnableLifetimeWarnings);
7378 if (Cap.capturesVariable())
7379 Path.pop_back();
7380 }
7381 }
7382
7383 // Assume that a copy or move from a temporary references the same objects
7384 // that the temporary does.
7385 if (auto *CCE = dyn_cast<CXXConstructExpr>(Init)) {
7386 if (CCE->getConstructor()->isCopyOrMoveConstructor()) {
7387 if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(CCE->getArg(0))) {
7388 Expr *Arg = MTE->getSubExpr();
7389 Path.push_back({IndirectLocalPathEntry::TemporaryCopy, Arg,
7390 CCE->getConstructor()});
7391 visitLocalsRetainedByInitializer(Path, Arg, Visit, true,
7392 /*EnableLifetimeWarnings*/false);
7393 Path.pop_back();
7394 }
7395 }
7396 }
7397
7398 if (isa<CallExpr>(Init) || isa<CXXConstructExpr>(Init)) {
7399 if (EnableLifetimeWarnings)
7400 handleGslAnnotatedTypes(Path, Init, Visit);
7401 return visitLifetimeBoundArguments(Path, Init, Visit);
7402 }
7403
7404 switch (Init->getStmtClass()) {
7405 case Stmt::UnaryOperatorClass: {
7406 auto *UO = cast<UnaryOperator>(Init);
7407 // If the initializer is the address of a local, we could have a lifetime
7408 // problem.
7409 if (UO->getOpcode() == UO_AddrOf) {
7410 // If this is &rvalue, then it's ill-formed and we have already diagnosed
7411 // it. Don't produce a redundant warning about the lifetime of the
7412 // temporary.
7413 if (isa<MaterializeTemporaryExpr>(UO->getSubExpr()))
7414 return;
7415
7416 Path.push_back({IndirectLocalPathEntry::AddressOf, UO});
7417 visitLocalsRetainedByReferenceBinding(Path, UO->getSubExpr(),
7418 RK_ReferenceBinding, Visit,
7419 EnableLifetimeWarnings);
7420 }
7421 break;
7422 }
7423
7424 case Stmt::BinaryOperatorClass: {
7425 // Handle pointer arithmetic.
7426 auto *BO = cast<BinaryOperator>(Init);
7427 BinaryOperatorKind BOK = BO->getOpcode();
7428 if (!BO->getType()->isPointerType() || (BOK != BO_Add && BOK != BO_Sub))
7429 break;
7430
7431 if (BO->getLHS()->getType()->isPointerType())
7432 visitLocalsRetainedByInitializer(Path, BO->getLHS(), Visit, true,
7433 EnableLifetimeWarnings);
7434 else if (BO->getRHS()->getType()->isPointerType())
7435 visitLocalsRetainedByInitializer(Path, BO->getRHS(), Visit, true,
7436 EnableLifetimeWarnings);
7437 break;
7438 }
7439
7440 case Stmt::ConditionalOperatorClass:
7441 case Stmt::BinaryConditionalOperatorClass: {
7442 auto *C = cast<AbstractConditionalOperator>(Init);
7443 // In C++, we can have a throw-expression operand, which has 'void' type
7444 // and isn't interesting from a lifetime perspective.
7445 if (!C->getTrueExpr()->getType()->isVoidType())
7446 visitLocalsRetainedByInitializer(Path, C->getTrueExpr(), Visit, true,
7447 EnableLifetimeWarnings);
7448 if (!C->getFalseExpr()->getType()->isVoidType())
7449 visitLocalsRetainedByInitializer(Path, C->getFalseExpr(), Visit, true,
7450 EnableLifetimeWarnings);
7451 break;
7452 }
7453
7454 case Stmt::BlockExprClass:
7455 if (cast<BlockExpr>(Init)->getBlockDecl()->hasCaptures()) {
7456 // This is a local block, whose lifetime is that of the function.
7457 Visit(Path, Local(cast<BlockExpr>(Init)), RK_ReferenceBinding);
7458 }
7459 break;
7460
7461 case Stmt::AddrLabelExprClass:
7462 // We want to warn if the address of a label would escape the function.
7463 Visit(Path, Local(cast<AddrLabelExpr>(Init)), RK_ReferenceBinding);
7464 break;
7465
7466 default:
7467 break;
7468 }
7469}
7470
7471/// Whether a path to an object supports lifetime extension.
7472enum PathLifetimeKind {
7473 /// Lifetime-extend along this path.
7474 Extend,
7475 /// We should lifetime-extend, but we don't because (due to technical
7476 /// limitations) we can't. This happens for default member initializers,
7477 /// which we don't clone for every use, so we don't have a unique
7478 /// MaterializeTemporaryExpr to update.
7479 ShouldExtend,
7480 /// Do not lifetime extend along this path.
7481 NoExtend
7482};
7483
7484/// Determine whether this is an indirect path to a temporary that we are
7485/// supposed to lifetime-extend along.
7486static PathLifetimeKind
7487shouldLifetimeExtendThroughPath(const IndirectLocalPath &Path) {
7488 PathLifetimeKind Kind = PathLifetimeKind::Extend;
7489 for (auto Elem : Path) {
7490 if (Elem.Kind == IndirectLocalPathEntry::DefaultInit)
7491 Kind = PathLifetimeKind::ShouldExtend;
7492 else if (Elem.Kind != IndirectLocalPathEntry::LambdaCaptureInit)
7493 return PathLifetimeKind::NoExtend;
7494 }
7495 return Kind;
7496}
7497
7498/// Find the range for the first interesting entry in the path at or after I.
7499static SourceRange nextPathEntryRange(const IndirectLocalPath &Path, unsigned I,
7500 Expr *E) {
7501 for (unsigned N = Path.size(); I != N; ++I) {
7502 switch (Path[I].Kind) {
7503 case IndirectLocalPathEntry::AddressOf:
7504 case IndirectLocalPathEntry::LValToRVal:
7505 case IndirectLocalPathEntry::LifetimeBoundCall:
7506 case IndirectLocalPathEntry::TemporaryCopy:
7507 case IndirectLocalPathEntry::GslReferenceInit:
7508 case IndirectLocalPathEntry::GslPointerInit:
7509 // These exist primarily to mark the path as not permitting or
7510 // supporting lifetime extension.
7511 break;
7512
7513 case IndirectLocalPathEntry::VarInit:
7514 if (cast<VarDecl>(Path[I].D)->isImplicit())
7515 return SourceRange();
7516 LLVM_FALLTHROUGH[[gnu::fallthrough]];
7517 case IndirectLocalPathEntry::DefaultInit:
7518 return Path[I].E->getSourceRange();
7519
7520 case IndirectLocalPathEntry::LambdaCaptureInit:
7521 if (!Path[I].Capture->capturesVariable())
7522 continue;
7523 return Path[I].E->getSourceRange();
7524 }
7525 }
7526 return E->getSourceRange();
7527}
7528
7529static bool pathOnlyInitializesGslPointer(IndirectLocalPath &Path) {
7530 for (auto It = Path.rbegin(), End = Path.rend(); It != End; ++It) {
7531 if (It->Kind == IndirectLocalPathEntry::VarInit)
7532 continue;
7533 if (It->Kind == IndirectLocalPathEntry::AddressOf)
7534 continue;
7535 if (It->Kind == IndirectLocalPathEntry::LifetimeBoundCall)
7536 continue;
7537 return It->Kind == IndirectLocalPathEntry::GslPointerInit ||
7538 It->Kind == IndirectLocalPathEntry::GslReferenceInit;
7539 }
7540 return false;
7541}
7542
7543void Sema::checkInitializerLifetime(const InitializedEntity &Entity,
7544 Expr *Init) {
7545 LifetimeResult LR = getEntityLifetime(&Entity);
7546 LifetimeKind LK = LR.getInt();
7547 const InitializedEntity *ExtendingEntity = LR.getPointer();
7548
7549 // If this entity doesn't have an interesting lifetime, don't bother looking
7550 // for temporaries within its initializer.
7551 if (LK == LK_FullExpression)
7552 return;
7553
7554 auto TemporaryVisitor = [&](IndirectLocalPath &Path, Local L,
7555 ReferenceKind RK) -> bool {
7556 SourceRange DiagRange = nextPathEntryRange(Path, 0, L);
7557 SourceLocation DiagLoc = DiagRange.getBegin();
7558
7559 auto *MTE = dyn_cast<MaterializeTemporaryExpr>(L);
7560
7561 bool IsGslPtrInitWithGslTempOwner = false;
7562 bool IsLocalGslOwner = false;
7563 if (pathOnlyInitializesGslPointer(Path)) {
7564 if (isa<DeclRefExpr>(L)) {
7565 // We do not want to follow the references when returning a pointer originating
7566 // from a local owner to avoid the following false positive:
7567 // int &p = *localUniquePtr;
7568 // someContainer.add(std::move(localUniquePtr));
7569 // return p;
7570 IsLocalGslOwner = isRecordWithAttr<OwnerAttr>(L->getType());
7571 if (pathContainsInit(Path) || !IsLocalGslOwner)
7572 return false;
7573 } else {
7574 IsGslPtrInitWithGslTempOwner = MTE && !MTE->getExtendingDecl() &&
7575 isRecordWithAttr<OwnerAttr>(MTE->getType());
7576 // Skipping a chain of initializing gsl::Pointer annotated objects.
7577 // We are looking only for the final source to find out if it was
7578 // a local or temporary owner or the address of a local variable/param.
7579 if (!IsGslPtrInitWithGslTempOwner)
7580 return true;
7581 }
7582 }
7583
7584 switch (LK) {
7585 case LK_FullExpression:
7586 llvm_unreachable("already handled this")__builtin_unreachable();
7587
7588 case LK_Extended: {
7589 if (!MTE) {
7590 // The initialized entity has lifetime beyond the full-expression,
7591 // and the local entity does too, so don't warn.
7592 //
7593 // FIXME: We should consider warning if a static / thread storage
7594 // duration variable retains an automatic storage duration local.
7595 return false;
7596 }
7597
7598 if (IsGslPtrInitWithGslTempOwner && DiagLoc.isValid()) {
7599 Diag(DiagLoc, diag::warn_dangling_lifetime_pointer) << DiagRange;
7600 return false;
7601 }
7602
7603 switch (shouldLifetimeExtendThroughPath(Path)) {
7604 case PathLifetimeKind::Extend:
7605 // Update the storage duration of the materialized temporary.
7606 // FIXME: Rebuild the expression instead of mutating it.
7607 MTE->setExtendingDecl(ExtendingEntity->getDecl(),
7608 ExtendingEntity->allocateManglingNumber());
7609 // Also visit the temporaries lifetime-extended by this initializer.
7610 return true;
7611
7612 case PathLifetimeKind::ShouldExtend:
7613 // We're supposed to lifetime-extend the temporary along this path (per
7614 // the resolution of DR1815), but we don't support that yet.
7615 //
7616 // FIXME: Properly handle this situation. Perhaps the easiest approach
7617 // would be to clone the initializer expression on each use that would
7618 // lifetime extend its temporaries.
7619 Diag(DiagLoc, diag::warn_unsupported_lifetime_extension)
7620 << RK << DiagRange;
7621 break;
7622
7623 case PathLifetimeKind::NoExtend:
7624 // If the path goes through the initialization of a variable or field,
7625 // it can't possibly reach a temporary created in this full-expression.
7626 // We will have already diagnosed any problems with the initializer.
7627 if (pathContainsInit(Path))
7628 return false;
7629
7630 Diag(DiagLoc, diag::warn_dangling_variable)
7631 << RK << !Entity.getParent()
7632 << ExtendingEntity->getDecl()->isImplicit()
7633 << ExtendingEntity->getDecl() << Init->isGLValue() << DiagRange;
7634 break;
7635 }
7636 break;
7637 }
7638
7639 case LK_MemInitializer: {
7640 if (isa<MaterializeTemporaryExpr>(L)) {
7641 // Under C++ DR1696, if a mem-initializer (or a default member
7642 // initializer used by the absence of one) would lifetime-extend a
7643 // temporary, the program is ill-formed.
7644 if (auto *ExtendingDecl =
7645 ExtendingEntity ? ExtendingEntity->getDecl() : nullptr) {
7646 if (IsGslPtrInitWithGslTempOwner) {
7647 Diag(DiagLoc, diag::warn_dangling_lifetime_pointer_member)
7648 << ExtendingDecl << DiagRange;
7649 Diag(ExtendingDecl->getLocation(),
7650 diag::note_ref_or_ptr_member_declared_here)
7651 << true;
7652 return false;
7653 }
7654 bool IsSubobjectMember = ExtendingEntity != &Entity;
7655 Diag(DiagLoc, shouldLifetimeExtendThroughPath(Path) !=
7656 PathLifetimeKind::NoExtend
7657 ? diag::err_dangling_member
7658 : diag::warn_dangling_member)
7659 << ExtendingDecl << IsSubobjectMember << RK << DiagRange;
7660 // Don't bother adding a note pointing to the field if we're inside
7661 // its default member initializer; our primary diagnostic points to
7662 // the same place in that case.
7663 if (Path.empty() ||
7664 Path.back().Kind != IndirectLocalPathEntry::DefaultInit) {
7665 Diag(ExtendingDecl->getLocation(),
7666 diag::note_lifetime_extending_member_declared_here)
7667 << RK << IsSubobjectMember;
7668 }
7669 } else {
7670 // We have a mem-initializer but no particular field within it; this
7671 // is either a base class or a delegating initializer directly
7672 // initializing the base-class from something that doesn't live long
7673 // enough.
7674 //
7675 // FIXME: Warn on this.
7676 return false;
7677 }
7678 } else {
7679 // Paths via a default initializer can only occur during error recovery
7680 // (there's no other way that a default initializer can refer to a
7681 // local). Don't produce a bogus warning on those cases.
7682 if (pathContainsInit(Path))
7683 return false;
7684
7685 // Suppress false positives for code like the one below:
7686 // Ctor(unique_ptr<T> up) : member(*up), member2(move(up)) {}
7687 if (IsLocalGslOwner && pathOnlyInitializesGslPointer(Path))
7688 return false;
7689
7690 auto *DRE = dyn_cast<DeclRefExpr>(L);
7691 auto *VD = DRE ? dyn_cast<VarDecl>(DRE->getDecl()) : nullptr;
7692 if (!VD) {
7693 // A member was initialized to a local block.
7694 // FIXME: Warn on this.
7695 return false;
7696 }
7697
7698 if (auto *Member =
7699 ExtendingEntity ? ExtendingEntity->getDecl() : nullptr) {
7700 bool IsPointer = !Member->getType()->isReferenceType();
7701 Diag(DiagLoc, IsPointer ? diag::warn_init_ptr_member_to_parameter_addr
7702 : diag::warn_bind_ref_member_to_parameter)
7703 << Member << VD << isa<ParmVarDecl>(VD) << DiagRange;
7704 Diag(Member->getLocation(),
7705 diag::note_ref_or_ptr_member_declared_here)
7706 << (unsigned)IsPointer;
7707 }
7708 }
7709 break;
7710 }
7711
7712 case LK_New:
7713 if (isa<MaterializeTemporaryExpr>(L)) {
7714 if (IsGslPtrInitWithGslTempOwner)
7715 Diag(DiagLoc, diag::warn_dangling_lifetime_pointer) << DiagRange;
7716 else
7717 Diag(DiagLoc, RK == RK_ReferenceBinding
7718 ? diag::warn_new_dangling_reference
7719 : diag::warn_new_dangling_initializer_list)
7720 << !Entity.getParent() << DiagRange;
7721 } else {
7722 // We can't determine if the allocation outlives the local declaration.
7723 return false;
7724 }
7725 break;
7726
7727 case LK_Return:
7728 case LK_StmtExprResult:
7729 if (auto *DRE = dyn_cast<DeclRefExpr>(L)) {
7730 // We can't determine if the local variable outlives the statement
7731 // expression.
7732 if (LK == LK_StmtExprResult)
7733 return false;
7734 Diag(DiagLoc, diag::warn_ret_stack_addr_ref)
7735 << Entity.getType()->isReferenceType() << DRE->getDecl()
7736 << isa<ParmVarDecl>(DRE->getDecl()) << DiagRange;
7737 } else if (isa<BlockExpr>(L)) {
7738 Diag(DiagLoc, diag::err_ret_local_block) << DiagRange;
7739 } else if (isa<AddrLabelExpr>(L)) {
7740 // Don't warn when returning a label from a statement expression.
7741 // Leaving the scope doesn't end its lifetime.
7742 if (LK == LK_StmtExprResult)
7743 return false;
7744 Diag(DiagLoc, diag::warn_ret_addr_label) << DiagRange;
7745 } else {
7746 Diag(DiagLoc, diag::warn_ret_local_temp_addr_ref)
7747 << Entity.getType()->isReferenceType() << DiagRange;
7748 }
7749 break;
7750 }
7751
7752 for (unsigned I = 0; I != Path.size(); ++I) {
7753 auto Elem = Path[I];
7754
7755 switch (Elem.Kind) {
7756 case IndirectLocalPathEntry::AddressOf:
7757 case IndirectLocalPathEntry::LValToRVal:
7758 // These exist primarily to mark the path as not permitting or
7759 // supporting lifetime extension.
7760 break;
7761
7762 case IndirectLocalPathEntry::LifetimeBoundCall:
7763 case IndirectLocalPathEntry::TemporaryCopy:
7764 case IndirectLocalPathEntry::GslPointerInit:
7765 case IndirectLocalPathEntry::GslReferenceInit:
7766 // FIXME: Consider adding a note for these.
7767 break;
7768
7769 case IndirectLocalPathEntry::DefaultInit: {
7770 auto *FD = cast<FieldDecl>(Elem.D);
7771 Diag(FD->getLocation(), diag::note_init_with_default_member_initalizer)
7772 << FD << nextPathEntryRange(Path, I + 1, L);
7773 break;
7774 }
7775
7776 case IndirectLocalPathEntry::VarInit: {
7777 const VarDecl *VD = cast<VarDecl>(Elem.D);
7778 Diag(VD->getLocation(), diag::note_local_var_initializer)
7779 << VD->getType()->isReferenceType()
7780 << VD->isImplicit() << VD->getDeclName()
7781 << nextPathEntryRange(Path, I + 1, L);
7782 break;
7783 }
7784
7785 case IndirectLocalPathEntry::LambdaCaptureInit:
7786 if (!Elem.Capture->capturesVariable())
7787 break;
7788 // FIXME: We can't easily tell apart an init-capture from a nested
7789 // capture of an init-capture.
7790 const VarDecl *VD = Elem.Capture->getCapturedVar();
7791 Diag(Elem.Capture->getLocation(), diag::note_lambda_capture_initializer)
7792 << VD << VD->isInitCapture() << Elem.Capture->isExplicit()
7793 << (Elem.Capture->getCaptureKind() == LCK_ByRef) << VD
7794 << nextPathEntryRange(Path, I + 1, L);
7795 break;
7796 }
7797 }
7798
7799 // We didn't lifetime-extend, so don't go any further; we don't need more
7800 // warnings or errors on inner temporaries within this one's initializer.
7801 return false;
7802 };
7803
7804 bool EnableLifetimeWarnings = !getDiagnostics().isIgnored(
7805 diag::warn_dangling_lifetime_pointer, SourceLocation());
7806 llvm::SmallVector<IndirectLocalPathEntry, 8> Path;
7807 if (Init->isGLValue())
7808 visitLocalsRetainedByReferenceBinding(Path, Init, RK_ReferenceBinding,
7809 TemporaryVisitor,
7810 EnableLifetimeWarnings);
7811 else
7812 visitLocalsRetainedByInitializer(Path, Init, TemporaryVisitor, false,
7813 EnableLifetimeWarnings);
7814}
7815
7816static void DiagnoseNarrowingInInitList(Sema &S,
7817 const ImplicitConversionSequence &ICS,
7818 QualType PreNarrowingType,
7819 QualType EntityType,
7820 const Expr *PostInit);
7821
7822/// Provide warnings when std::move is used on construction.
7823static void CheckMoveOnConstruction(Sema &S, const Expr *InitExpr,
7824 bool IsReturnStmt) {
7825 if (!InitExpr)
7826 return;
7827
7828 if (S.inTemplateInstantiation())
7829 return;
7830
7831 QualType DestType = InitExpr->getType();
7832 if (!DestType->isRecordType())
7833 return;
7834
7835 unsigned DiagID = 0;
7836 if (IsReturnStmt) {
7837 const CXXConstructExpr *CCE =
7838 dyn_cast<CXXConstructExpr>(InitExpr->IgnoreParens());
7839 if (!CCE || CCE->getNumArgs() != 1)
7840 return;
7841
7842 if (!CCE->getConstructor()->isCopyOrMoveConstructor())
7843 return;
7844
7845 InitExpr = CCE->getArg(0)->IgnoreImpCasts();
7846 }
7847
7848 // Find the std::move call and get the argument.
7849 const CallExpr *CE = dyn_cast<CallExpr>(InitExpr->IgnoreParens());
7850 if (!CE || !CE->isCallToStdMove())
7851 return;
7852
7853 const Expr *Arg = CE->getArg(0)->IgnoreImplicit();
7854
7855 if (IsReturnStmt) {
7856 const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg->IgnoreParenImpCasts());
7857 if (!DRE || DRE->refersToEnclosingVariableOrCapture())
7858 return;
7859
7860 const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl());
7861 if (!VD || !VD->hasLocalStorage())
7862 return;
7863
7864 // __block variables are not moved implicitly.
7865 if (VD->hasAttr<BlocksAttr>())
7866 return;
7867
7868 QualType SourceType = VD->getType();
7869 if (!SourceType->isRecordType())
7870 return;
7871
7872 if (!S.Context.hasSameUnqualifiedType(DestType, SourceType)) {
7873 return;
7874 }
7875
7876 // If we're returning a function parameter, copy elision
7877 // is not possible.
7878 if (isa<ParmVarDecl>(VD))
7879 DiagID = diag::warn_redundant_move_on_return;
7880 else
7881 DiagID = diag::warn_pessimizing_move_on_return;
7882 } else {
7883 DiagID = diag::warn_pessimizing_move_on_initialization;
7884 const Expr *ArgStripped = Arg->IgnoreImplicit()->IgnoreParens();
7885 if (!ArgStripped->isPRValue() || !ArgStripped->getType()->isRecordType())
7886 return;
7887 }
7888
7889 S.Diag(CE->getBeginLoc(), DiagID);
7890
7891 // Get all the locations for a fix-it. Don't emit the fix-it if any location
7892 // is within a macro.
7893 SourceLocation CallBegin = CE->getCallee()->getBeginLoc();
7894 if (CallBegin.isMacroID())
7895 return;
7896 SourceLocation RParen = CE->getRParenLoc();
7897 if (RParen.isMacroID())
7898 return;
7899 SourceLocation LParen;
7900 SourceLocation ArgLoc = Arg->getBeginLoc();
7901
7902 // Special testing for the argument location. Since the fix-it needs the
7903 // location right before the argument, the argument location can be in a
7904 // macro only if it is at the beginning of the macro.
7905 while (ArgLoc.isMacroID() &&
7906 S.getSourceManager().isAtStartOfImmediateMacroExpansion(ArgLoc)) {
7907 ArgLoc = S.getSourceManager().getImmediateExpansionRange(ArgLoc).getBegin();
7908 }
7909
7910 if (LParen.isMacroID())
7911 return;
7912
7913 LParen = ArgLoc.getLocWithOffset(-1);
7914
7915 S.Diag(CE->getBeginLoc(), diag::note_remove_move)
7916 << FixItHint::CreateRemoval(SourceRange(CallBegin, LParen))
7917 << FixItHint::CreateRemoval(SourceRange(RParen, RParen));
7918}
7919
7920static void CheckForNullPointerDereference(Sema &S, const Expr *E) {
7921 // Check to see if we are dereferencing a null pointer. If so, this is
7922 // undefined behavior, so warn about it. This only handles the pattern
7923 // "*null", which is a very syntactic check.
7924 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E->IgnoreParenCasts()))
7925 if (UO->getOpcode() == UO_Deref &&
7926 UO->getSubExpr()->IgnoreParenCasts()->
7927 isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull)) {
7928 S.DiagRuntimeBehavior(UO->getOperatorLoc(), UO,
7929 S.PDiag(diag::warn_binding_null_to_reference)
7930 << UO->getSubExpr()->getSourceRange());
7931 }
7932}
7933
7934MaterializeTemporaryExpr *
7935Sema::CreateMaterializeTemporaryExpr(QualType T, Expr *Temporary,
7936 bool BoundToLvalueReference) {
7937 auto MTE = new (Context)
7938 MaterializeTemporaryExpr(T, Temporary, BoundToLvalueReference);
7939
7940 // Order an ExprWithCleanups for lifetime marks.
7941 //
7942 // TODO: It'll be good to have a single place to check the access of the
7943 // destructor and generate ExprWithCleanups for various uses. Currently these
7944 // are done in both CreateMaterializeTemporaryExpr and MaybeBindToTemporary,
7945 // but there may be a chance to merge them.
7946 Cleanup.setExprNeedsCleanups(false);
7947 return MTE;
7948}
7949
7950ExprResult Sema::TemporaryMaterializationConversion(Expr *E) {
7951 // In C++98, we don't want to implicitly create an xvalue.
7952 // FIXME: This means that AST consumers need to deal with "prvalues" that
7953 // denote materialized temporaries. Maybe we should add another ValueKind
7954 // for "xvalue pretending to be a prvalue" for C++98 support.
7955 if (!E->isPRValue() || !getLangOpts().CPlusPlus11)
7956 return E;
7957
7958 // C++1z [conv.rval]/1: T shall be a complete type.
7959 // FIXME: Does this ever matter (can we form a prvalue of incomplete type)?
7960 // If so, we should check for a non-abstract class type here too.
7961 QualType T = E->getType();
7962 if (RequireCompleteType(E->getExprLoc(), T, diag::err_incomplete_type))
7963 return ExprError();
7964
7965 return CreateMaterializeTemporaryExpr(E->getType(), E, false);
7966}
7967
7968ExprResult Sema::PerformQualificationConversion(Expr *E, QualType Ty,
7969 ExprValueKind VK,
7970 CheckedConversionKind CCK) {
7971
7972 CastKind CK = CK_NoOp;
7973
7974 if (VK == VK_PRValue) {
7975 auto PointeeTy = Ty->getPointeeType();
7976 auto ExprPointeeTy = E->getType()->getPointeeType();
7977 if (!PointeeTy.isNull() &&
7978 PointeeTy.getAddressSpace() != ExprPointeeTy.getAddressSpace())
7979 CK = CK_AddressSpaceConversion;
7980 } else if (Ty.getAddressSpace() != E->getType().getAddressSpace()) {
7981 CK = CK_AddressSpaceConversion;
7982 }
7983
7984 return ImpCastExprToType(E, Ty, CK, VK, /*BasePath=*/nullptr, CCK);
7985}
7986
7987ExprResult InitializationSequence::Perform(Sema &S,
7988 const InitializedEntity &Entity,
7989 const InitializationKind &Kind,
7990 MultiExprArg Args,
7991 QualType *ResultType) {
7992 if (Failed()) {
1
Taking false branch
→
7993 Diagnose(S, Entity, Kind, Args);
7994 return ExprError();
7995 }
7996 if (!ZeroInitializationFixit.empty()) {
2
←
Assuming the condition is false
→
3
←
Taking false branch
→
7997 unsigned DiagID = diag::err_default_init_const;
7998 if (Decl *D = Entity.getDecl())
7999 if (S.getLangOpts().MSVCCompat && D->hasAttr<SelectAnyAttr>())
8000 DiagID = diag::ext_default_init_const;
8001
8002 // The initialization would have succeeded with this fixit. Since the fixit
8003 // is on the error, we need to build a valid AST in this case, so this isn't
8004 // handled in the Failed() branch above.
8005 QualType DestType = Entity.getType();
8006 S.Diag(Kind.getLocation(), DiagID)
8007 << DestType << (bool)DestType->getAs<RecordType>()
8008 << FixItHint::CreateInsertion(ZeroInitializationFixitLoc,
8009 ZeroInitializationFixit);
8010 }
8011
8012 if (getKind() == DependentSequence) {
4
←
Assuming the condition is false
→
5
←
Taking false branch
→
8013 // If the declaration is a non-dependent, incomplete array type
8014 // that has an initializer, then its type will be completed once
8015 // the initializer is instantiated.
8016 if (ResultType && !Entity.getType()->isDependentType() &&
8017 Args.size() == 1) {
8018 QualType DeclType = Entity.getType();
8019 if (const IncompleteArrayType *ArrayT
8020 = S.Context.getAsIncompleteArrayType(DeclType)) {
8021 // FIXME: We don't currently have the ability to accurately
8022 // compute the length of an initializer list without
8023 // performing full type-checking of the initializer list
8024 // (since we have to determine where braces are implicitly
8025 // introduced and such). So, we fall back to making the array
8026 // type a dependently-sized array type with no specified
8027 // bound.
8028 if (isa<InitListExpr>((Expr *)Args[0])) {
8029 SourceRange Brackets;
8030
8031 // Scavange the location of the brackets from the entity, if we can.
8032 if (auto *DD = dyn_cast_or_null<DeclaratorDecl>(Entity.getDecl())) {
8033 if (TypeSourceInfo *TInfo = DD->getTypeSourceInfo()) {
8034 TypeLoc TL = TInfo->getTypeLoc();
8035 if (IncompleteArrayTypeLoc ArrayLoc =
8036 TL.getAs<IncompleteArrayTypeLoc>())
8037 Brackets = ArrayLoc.getBracketsRange();
8038 }
8039 }
8040
8041 *ResultType
8042 = S.Context.getDependentSizedArrayType(ArrayT->getElementType(),
8043 /*NumElts=*/nullptr,
8044 ArrayT->getSizeModifier(),
8045 ArrayT->getIndexTypeCVRQualifiers(),
8046 Brackets);
8047 }
8048
8049 }
8050 }
8051 if (Kind.getKind() == InitializationKind::IK_Direct &&
8052 !Kind.isExplicitCast()) {
8053 // Rebuild the ParenListExpr.
8054 SourceRange ParenRange = Kind.getParenOrBraceRange();
8055 return S.ActOnParenListExpr(ParenRange.getBegin(), ParenRange.getEnd(),
8056 Args);
8057 }
8058 assert(Kind.getKind() == InitializationKind::IK_Copy ||((void)0)
8059 Kind.isExplicitCast() ||((void)0)
8060 Kind.getKind() == InitializationKind::IK_DirectList)((void)0);
8061 return ExprResult(Args[0]);
8062 }
8063
8064 // No steps means no initialization.
8065 if (Steps.empty())
6
←
Taking false branch
→
8066 return ExprResult((Expr *)nullptr);
8067
8068 if (S.getLangOpts().CPlusPlus11 && Entity.getType()->isReferenceType() &&
7
←
Assuming field 'CPlusPlus11' is 0
→
8
←
Taking false branch
→
8069 Args.size() == 1 && isa<InitListExpr>(Args[0]) &&
8070 !Entity.isParamOrTemplateParamKind()) {
8071 // Produce a C++98 compatibility warning if we are initializing a reference
8072 // from an initializer list. For parameters, we produce a better warning
8073 // elsewhere.
8074 Expr *Init = Args[0];
8075 S.Diag(Init->getBeginLoc(), diag::warn_cxx98_compat_reference_list_init)
8076 << Init->getSourceRange();
8077 }
8078
8079 // OpenCL v2.0 s6.13.11.1. atomic variables can be initialized in global scope
8080 QualType ETy = Entity.getType();
8081 bool HasGlobalAS = ETy.hasAddressSpace() &&
9
←
Assuming the condition is false
→
8082 ETy.getAddressSpace() == LangAS::opencl_global;
8083
8084 if (S.getLangOpts().OpenCLVersion >= 200 &&
10
←
Assuming field 'OpenCLVersion' is < 200
→
8085 ETy->isAtomicType() && !HasGlobalAS &&
8086 Entity.getKind() == InitializedEntity::EK_Variable && Args.size() > 0) {
8087 S.Diag(Args[0]->getBeginLoc(), diag::err_opencl_atomic_init)
8088 << 1
8089 << SourceRange(Entity.getDecl()->getBeginLoc(), Args[0]->getEndLoc());
8090 return ExprError();
8091 }
8092
8093 QualType DestType = Entity.getType().getNonReferenceType();
8094 // FIXME: Ugly hack around the fact that Entity.getType() is not
8095 // the same as Entity.getDecl()->getType() in cases involving type merging,
8096 // and we want latter when it makes sense.
8097 if (ResultType)
11
←
Assuming 'ResultType' is null
→
12
←
Taking false branch
→
8098 *ResultType = Entity.getDecl() ? Entity.getDecl()->getType() :
8099 Entity.getType();
8100
8101 ExprResult CurInit((Expr *)nullptr);
8102 SmallVector<Expr*, 4> ArrayLoopCommonExprs;
8103
8104 // For initialization steps that start with a single initializer,
8105 // grab the only argument out the Args and place it into the "current"
8106 // initializer.
8107 switch (Steps.front().Kind) {
13
←
Control jumps to 'case SK_ConstructorInitialization:' at line 8147
→
8108 case SK_ResolveAddressOfOverloadedFunction:
8109 case SK_CastDerivedToBasePRValue:
8110 case SK_CastDerivedToBaseXValue:
8111 case SK_CastDerivedToBaseLValue:
8112 case SK_BindReference:
8113 case SK_BindReferenceToTemporary:
8114 case SK_FinalCopy:
8115 case SK_ExtraneousCopyToTemporary:
8116 case SK_UserConversion:
8117 case SK_QualificationConversionLValue:
8118 case SK_QualificationConversionXValue:
8119 case SK_QualificationConversionPRValue:
8120 case SK_FunctionReferenceConversion:
8121 case SK_AtomicConversion:
8122 case SK_ConversionSequence:
8123 case SK_ConversionSequenceNoNarrowing:
8124 case SK_ListInitialization:
8125 case SK_UnwrapInitList:
8126 case SK_RewrapInitList:
8127 case SK_CAssignment:
8128 case SK_StringInit:
8129 case SK_ObjCObjectConversion:
8130 case SK_ArrayLoopIndex:
8131 case SK_ArrayLoopInit:
8132 case SK_ArrayInit:
8133 case SK_GNUArrayInit:
8134 case SK_ParenthesizedArrayInit:
8135 case SK_PassByIndirectCopyRestore:
8136 case SK_PassByIndirectRestore:
8137 case SK_ProduceObjCObject:
8138 case SK_StdInitializerList:
8139 case SK_OCLSamplerInit:
8140 case SK_OCLZeroOpaqueType: {
8141 assert(Args.size() == 1)((void)0);
8142 CurInit = Args[0];
8143 if (!CurInit.get()) return ExprError();
8144 break;
8145 }
8146
8147 case SK_ConstructorInitialization:
8148 case SK_ConstructorInitializationFromList:
8149 case SK_StdInitializerListConstructorCall:
8150 case SK_ZeroInitialization:
8151 break;
14
←
 Execution continues on line 8158
→
8152 }
8153
8154 // Promote from an unevaluated context to an unevaluated list context in
8155 // C++11 list-initialization; we need to instantiate entities usable in
8156 // constant expressions here in order to perform narrowing checks =(
8157 EnterExpressionEvaluationContext Evaluated(
8158 S, EnterExpressionEvaluationContext::InitList,
8159 CurInit.get() && isa<InitListExpr>(CurInit.get()));
8160
8161 // C++ [class.abstract]p2:
8162 // no objects of an abstract class can be created except as subobjects
8163 // of a class derived from it
8164 auto checkAbstractType = [&](QualType T) -> bool {
8165 if (Entity.getKind() == InitializedEntity::EK_Base ||
8166 Entity.getKind() == InitializedEntity::EK_Delegating)
8167 return false;
8168 return S.RequireNonAbstractType(Kind.getLocation(), T,
8169 diag::err_allocation_of_abstract_type);
8170 };
8171
8172 // Walk through the computed steps for the initialization sequence,
8173 // performing the specified conversions along the way.
8174 bool ConstructorInitRequiresZeroInit = false;
8175 for (step_iterator Step = step_begin(), StepEnd = step_end();
16
←
Loop condition is true. Entering loop body
→
8176 Step != StepEnd; ++Step) {
15
←
Assuming 'Step' is not equal to 'StepEnd'
→
8177 if (CurInit.isInvalid())
17
←
Taking false branch
→
8178 return ExprError();
8179
8180 QualType SourceType = CurInit.get() ? CurInit.get()->getType() : QualType();
18
←
'?' condition is false
→
8181
8182 switch (Step->Kind) {
19
←
Control jumps to 'case SK_ConstructorInitializationFromList:' at line 8491
→
8183 case SK_ResolveAddressOfOverloadedFunction:
8184 // Overload resolution determined which function invoke; update the
8185 // initializer to reflect that choice.
8186 S.CheckAddressOfMemberAccess(CurInit.get(), Step->Function.FoundDecl);
8187 if (S.DiagnoseUseOfDecl(Step->Function.FoundDecl, Kind.getLocation()))
8188 return ExprError();
8189 CurInit = S.FixOverloadedFunctionReference(CurInit,
8190 Step->Function.FoundDecl,
8191 Step->Function.Function);
8192 break;
8193
8194 case SK_CastDerivedToBasePRValue:
8195 case SK_CastDerivedToBaseXValue:
8196 case SK_CastDerivedToBaseLValue: {
8197 // We have a derived-to-base cast that produces either an rvalue or an
8198 // lvalue. Perform that cast.
8199
8200 CXXCastPath BasePath;
8201
8202 // Casts to inaccessible base classes are allowed with C-style casts.
8203 bool IgnoreBaseAccess = Kind.isCStyleOrFunctionalCast();
8204 if (S.CheckDerivedToBaseConversion(
8205 SourceType, Step->Type, CurInit.get()->getBeginLoc(),
8206 CurInit.get()->getSourceRange(), &BasePath, IgnoreBaseAccess))
8207 return ExprError();
8208
8209 ExprValueKind VK =
8210 Step->Kind == SK_CastDerivedToBaseLValue
8211 ? VK_LValue
8212 : (Step->Kind == SK_CastDerivedToBaseXValue ? VK_XValue
8213 : VK_PRValue);
8214 CurInit = ImplicitCastExpr::Create(S.Context, Step->Type,
8215 CK_DerivedToBase, CurInit.get(),
8216 &BasePath, VK, FPOptionsOverride());
8217 break;
8218 }
8219
8220 case SK_BindReference:
8221 // Reference binding does not have any corresponding ASTs.
8222
8223 // Check exception specifications
8224 if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType))
8225 return ExprError();
8226
8227 // We don't check for e.g. function pointers here, since address
8228 // availability checks should only occur when the function first decays
8229 // into a pointer or reference.
8230 if (CurInit.get()->getType()->isFunctionProtoType()) {
8231 if (auto *DRE = dyn_cast<DeclRefExpr>(CurInit.get()->IgnoreParens())) {
8232 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
8233 if (!S.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
8234 DRE->getBeginLoc()))
8235 return ExprError();
8236 }
8237 }
8238 }
8239
8240 CheckForNullPointerDereference(S, CurInit.get());
8241 break;
8242
8243 case SK_BindReferenceToTemporary: {
8244 // Make sure the "temporary" is actually an rvalue.
8245 assert(CurInit.get()->isPRValue() && "not a temporary")((void)0);
8246
8247 // Check exception specifications
8248 if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType))
8249 return ExprError();
8250
8251 QualType MTETy = Step->Type;
8252
8253 // When this is an incomplete array type (such as when this is
8254 // initializing an array of unknown bounds from an init list), use THAT
8255 // type instead so that we propogate the array bounds.
8256 if (MTETy->isIncompleteArrayType() &&
8257 !CurInit.get()->getType()->isIncompleteArrayType() &&
8258 S.Context.hasSameType(
8259 MTETy->getPointeeOrArrayElementType(),
8260 CurInit.get()->getType()->getPointeeOrArrayElementType()))
8261 MTETy = CurInit.get()->getType();
8262
8263 // Materialize the temporary into memory.
8264 MaterializeTemporaryExpr *MTE = S.CreateMaterializeTemporaryExpr(
8265 MTETy, CurInit.get(), Entity.getType()->isLValueReferenceType());
8266 CurInit = MTE;
8267
8268 // If we're extending this temporary to automatic storage duration -- we
8269 // need to register its cleanup during the full-expression's cleanups.
8270 if (MTE->getStorageDuration() == SD_Automatic &&
8271 MTE->getType().isDestructedType())
8272 S.Cleanup.setExprNeedsCleanups(true);
8273 break;
8274 }
8275
8276 case SK_FinalCopy:
8277 if (checkAbstractType(Step->Type))
8278 return ExprError();
8279
8280 // If the overall initialization is initializing a temporary, we already
8281 // bound our argument if it was necessary to do so. If not (if we're
8282 // ultimately initializing a non-temporary), our argument needs to be
8283 // bound since it's initializing a function parameter.
8284 // FIXME: This is a mess. Rationalize temporary destruction.
8285 if (!shouldBindAsTemporary(Entity))
8286 CurInit = S.MaybeBindToTemporary(CurInit.get());
8287 CurInit = CopyObject(S, Step->Type, Entity, CurInit,
8288 /*IsExtraneousCopy=*/false);
8289 break;
8290
8291 case SK_ExtraneousCopyToTemporary:
8292 CurInit = CopyObject(S, Step->Type, Entity, CurInit,
8293 /*IsExtraneousCopy=*/true);
8294 break;
8295
8296 case SK_UserConversion: {
8297 // We have a user-defined conversion that invokes either a constructor
8298 // or a conversion function.
8299 CastKind CastKind;
8300 FunctionDecl *Fn = Step->Function.Function;
8301 DeclAccessPair FoundFn = Step->Function.FoundDecl;
8302 bool HadMultipleCandidates = Step->Function.HadMultipleCandidates;
8303 bool CreatedObject = false;
8304 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Fn)) {
8305 // Build a call to the selected constructor.
8306 SmallVector<Expr*, 8> ConstructorArgs;
8307 SourceLocation Loc = CurInit.get()->getBeginLoc();
8308
8309 // Determine the arguments required to actually perform the constructor
8310 // call.
8311 Expr *Arg = CurInit.get();
8312 if (S.CompleteConstructorCall(Constructor, Step->Type,
8313 MultiExprArg(&Arg, 1), Loc,
8314 ConstructorArgs))
8315 return ExprError();
8316
8317 // Build an expression that constructs a temporary.
8318 CurInit = S.BuildCXXConstructExpr(Loc, Step->Type,
8319 FoundFn, Constructor,
8320 ConstructorArgs,
8321 HadMultipleCandidates,
8322 /*ListInit*/ false,
8323 /*StdInitListInit*/ false,
8324 /*ZeroInit*/ false,
8325 CXXConstructExpr::CK_Complete,
8326 SourceRange());
8327 if (CurInit.isInvalid())
8328 return ExprError();
8329
8330 S.CheckConstructorAccess(Kind.getLocation(), Constructor, FoundFn,
8331 Entity);
8332 if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation()))
8333 return ExprError();
8334
8335 CastKind = CK_ConstructorConversion;
8336 CreatedObject = true;
8337 } else {
8338 // Build a call to the conversion function.
8339 CXXConversionDecl *Conversion = cast<CXXConversionDecl>(Fn);
8340 S.CheckMemberOperatorAccess(Kind.getLocation(), CurInit.get(), nullptr,
8341 FoundFn);
8342 if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation()))
8343 return ExprError();
8344
8345 CurInit = S.BuildCXXMemberCallExpr(CurInit.get(), FoundFn, Conversion,
8346 HadMultipleCandidates);
8347 if (CurInit.isInvalid())
8348 return ExprError();
8349
8350 CastKind = CK_UserDefinedConversion;
8351 CreatedObject = Conversion->getReturnType()->isRecordType();
8352 }
8353
8354 if (CreatedObject && checkAbstractType(CurInit.get()->getType()))
8355 return ExprError();
8356
8357 CurInit = ImplicitCastExpr::Create(
8358 S.Context, CurInit.get()->getType(), CastKind, CurInit.get(), nullptr,
8359 CurInit.get()->getValueKind(), S.CurFPFeatureOverrides());
8360
8361 if (shouldBindAsTemporary(Entity))
8362 // The overall entity is temporary, so this expression should be
8363 // destroyed at the end of its full-expression.
8364 CurInit = S.MaybeBindToTemporary(CurInit.getAs<Expr>());
8365 else if (CreatedObject && shouldDestroyEntity(Entity)) {
8366 // The object outlasts the full-expression, but we need to prepare for
8367 // a destructor being run on it.
8368 // FIXME: It makes no sense to do this here. This should happen
8369 // regardless of how we initialized the entity.
8370 QualType T = CurInit.get()->getType();
8371 if (const RecordType *Record = T->getAs<RecordType>()) {
8372 CXXDestructorDecl *Destructor
8373 = S.LookupDestructor(cast<CXXRecordDecl>(Record->getDecl()));
8374 S.CheckDestructorAccess(CurInit.get()->getBeginLoc(), Destructor,
8375 S.PDiag(diag::err_access_dtor_temp) << T);
8376 S.MarkFunctionReferenced(CurInit.get()->getBeginLoc(), Destructor);
8377 if (S.DiagnoseUseOfDecl(Destructor, CurInit.get()->getBeginLoc()))
8378 return ExprError();
8379 }
8380 }
8381 break;
8382 }
8383
8384 case SK_QualificationConversionLValue:
8385 case SK_QualificationConversionXValue:
8386 case SK_QualificationConversionPRValue: {
8387 // Perform a qualification conversion; these can never go wrong.
8388 ExprValueKind VK =
8389 Step->Kind == SK_QualificationConversionLValue
8390 ? VK_LValue
8391 : (Step->Kind == SK_QualificationConversionXValue ? VK_XValue
8392 : VK_PRValue);
8393 CurInit = S.PerformQualificationConversion(CurInit.get(), Step->Type, VK);
8394 break;
8395 }
8396
8397 case SK_FunctionReferenceConversion:
8398 assert(CurInit.get()->isLValue() &&((void)0)
8399 "function reference should be lvalue")((void)0);
8400 CurInit =
8401 S.ImpCastExprToType(CurInit.get(), Step->Type, CK_NoOp, VK_LValue);
8402 break;
8403
8404 case SK_AtomicConversion: {
8405 assert(CurInit.get()->isPRValue() && "cannot convert glvalue to atomic")((void)0);
8406 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
8407 CK_NonAtomicToAtomic, VK_PRValue);
8408 break;
8409 }
8410
8411 case SK_ConversionSequence:
8412 case SK_ConversionSequenceNoNarrowing: {
8413 if (const auto *FromPtrType =
8414 CurInit.get()->getType()->getAs<PointerType>()) {
8415 if (const auto *ToPtrType = Step->Type->getAs<PointerType>()) {
8416 if (FromPtrType->getPointeeType()->hasAttr(attr::NoDeref) &&
8417 !ToPtrType->getPointeeType()->hasAttr(attr::NoDeref)) {
8418 // Do not check static casts here because they are checked earlier
8419 // in Sema::ActOnCXXNamedCast()
8420 if (!Kind.isStaticCast()) {
8421 S.Diag(CurInit.get()->getExprLoc(),
8422 diag::warn_noderef_to_dereferenceable_pointer)
8423 << CurInit.get()->getSourceRange();
8424 }
8425 }
8426 }
8427 }
8428
8429 Sema::CheckedConversionKind CCK
8430 = Kind.isCStyleCast()? Sema::CCK_CStyleCast
8431 : Kind.isFunctionalCast()? Sema::CCK_FunctionalCast
8432 : Kind.isExplicitCast()? Sema::CCK_OtherCast
8433 : Sema::CCK_ImplicitConversion;
8434 ExprResult CurInitExprRes =
8435 S.PerformImplicitConversion(CurInit.get(), Step->Type, *Step->ICS,
8436 getAssignmentAction(Entity), CCK);
8437 if (CurInitExprRes.isInvalid())
8438 return ExprError();
8439
8440 S.DiscardMisalignedMemberAddress(Step->Type.getTypePtr(), CurInit.get());
8441
8442 CurInit = CurInitExprRes;
8443
8444 if (Step->Kind == SK_ConversionSequenceNoNarrowing &&
8445 S.getLangOpts().CPlusPlus)
8446 DiagnoseNarrowingInInitList(S, *Step->ICS, SourceType, Entity.getType(),
8447 CurInit.get());
8448
8449 break;
8450 }
8451
8452 case SK_ListInitialization: {
8453 if (checkAbstractType(Step->Type))
8454 return ExprError();
8455
8456 InitListExpr *InitList = cast<InitListExpr>(CurInit.get());
8457 // If we're not initializing the top-level entity, we need to create an
8458 // InitializeTemporary entity for our target type.
8459 QualType Ty = Step->Type;
8460 bool IsTemporary = !S.Context.hasSameType(Entity.getType(), Ty);
8461 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(Ty);
8462 InitializedEntity InitEntity = IsTemporary ? TempEntity : Entity;
8463 InitListChecker PerformInitList(S, InitEntity,
8464 InitList, Ty, /*VerifyOnly=*/false,
8465 /*TreatUnavailableAsInvalid=*/false);
8466 if (PerformInitList.HadError())
8467 return ExprError();
8468
8469 // Hack: We must update *ResultType if available in order to set the
8470 // bounds of arrays, e.g. in 'int ar[] = {1, 2, 3};'.
8471 // Worst case: 'const int (&arref)[] = {1, 2, 3};'.
8472 if (ResultType &&
8473 ResultType->getNonReferenceType()->isIncompleteArrayType()) {
8474 if ((*ResultType)->isRValueReferenceType())
8475 Ty = S.Context.getRValueReferenceType(Ty);
8476 else if ((*ResultType)->isLValueReferenceType())
8477 Ty = S.Context.getLValueReferenceType(Ty,
8478 (*ResultType)->castAs<LValueReferenceType>()->isSpelledAsLValue());
8479 *ResultType = Ty;
8480 }
8481
8482 InitListExpr *StructuredInitList =
8483 PerformInitList.getFullyStructuredList();
8484 CurInit.get();
8485 CurInit = shouldBindAsTemporary(InitEntity)
8486 ? S.MaybeBindToTemporary(StructuredInitList)
8487 : StructuredInitList;
8488 break;
8489 }
8490
8491 case SK_ConstructorInitializationFromList: {
8492 if (checkAbstractType(Step->Type))
20
←
Assuming the condition is false
→
21
←
Taking false branch
→
8493 return ExprError();
8494
8495 // When an initializer list is passed for a parameter of type "reference
8496 // to object", we don't get an EK_Temporary entity, but instead an
8497 // EK_Parameter entity with reference type.
8498 // FIXME: This is a hack. What we really should do is create a user
8499 // conversion step for this case, but this makes it considerably more
8500 // complicated. For now, this will do.
8501 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(
8502 Entity.getType().getNonReferenceType());
8503 bool UseTemporary = Entity.getType()->isReferenceType();
8504 assert(Args.size() == 1 && "expected a single argument for list init")((void)0);
8505 InitListExpr *InitList = cast<InitListExpr>(Args[0]);
22
←
The object is a 'InitListExpr'
→
8506 S.Diag(InitList->getExprLoc(), diag::warn_cxx98_compat_ctor_list_init)
8507 << InitList->getSourceRange();
8508 MultiExprArg Arg(InitList->getInits(), InitList->getNumInits());
8509 CurInit = PerformConstructorInitialization(S, UseTemporary
22.1
'UseTemporary' is false
22.1
'UseTemporary' is false
 ? TempEntity :
23
←
'?' condition is false
→
24
←
Calling 'PerformConstructorInitialization'
→
8510 Entity,
8511 Kind, Arg, *Step,
8512 ConstructorInitRequiresZeroInit,
8513 /*IsListInitialization*/true,
8514 /*IsStdInitListInit*/false,
8515 InitList->getLBraceLoc(),
8516 InitList->getRBraceLoc());
8517 break;
8518 }
8519
8520 case SK_UnwrapInitList:
8521 CurInit = cast<InitListExpr>(CurInit.get())->getInit(0);
8522 break;
8523
8524 case SK_RewrapInitList: {
8525 Expr *E = CurInit.get();
8526 InitListExpr *Syntactic = Step->WrappingSyntacticList;
8527 InitListExpr *ILE = new (S.Context) InitListExpr(S.Context,
8528 Syntactic->getLBraceLoc(), E, Syntactic->getRBraceLoc());
8529 ILE->setSyntacticForm(Syntactic);
8530 ILE->setType(E->getType());
8531 ILE->setValueKind(E->getValueKind());
8532 CurInit = ILE;
8533 break;
8534 }
8535
8536 case SK_ConstructorInitialization:
8537 case SK_StdInitializerListConstructorCall: {
8538 if (checkAbstractType(Step->Type))
8539 return ExprError();
8540
8541 // When an initializer list is passed for a parameter of type "reference
8542 // to object", we don't get an EK_Temporary entity, but instead an
8543 // EK_Parameter entity with reference type.
8544 // FIXME: This is a hack. What we really should do is create a user
8545 // conversion step for this case, but this makes it considerably more
8546 // complicated. For now, this will do.
8547 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(
8548 Entity.getType().getNonReferenceType());
8549 bool UseTemporary = Entity.getType()->isReferenceType();
8550 bool IsStdInitListInit =
8551 Step->Kind == SK_StdInitializerListConstructorCall;
8552 Expr *Source = CurInit.get();
8553 SourceRange Range = Kind.hasParenOrBraceRange()
8554 ? Kind.getParenOrBraceRange()
8555 : SourceRange();
8556 CurInit = PerformConstructorInitialization(
8557 S, UseTemporary ? TempEntity : Entity, Kind,
8558 Source ? MultiExprArg(Source) : Args, *Step,
8559 ConstructorInitRequiresZeroInit,
8560 /*IsListInitialization*/ IsStdInitListInit,
8561 /*IsStdInitListInitialization*/ IsStdInitListInit,
8562 /*LBraceLoc*/ Range.getBegin(),
8563 /*RBraceLoc*/ Range.getEnd());
8564 break;
8565 }
8566
8567 case SK_ZeroInitialization: {
8568 step_iterator NextStep = Step;
8569 ++NextStep;
8570 if (NextStep != StepEnd &&
8571 (NextStep->Kind == SK_ConstructorInitialization ||
8572 NextStep->Kind == SK_ConstructorInitializationFromList)) {
8573 // The need for zero-initialization is recorded directly into
8574 // the call to the object's constructor within the next step.
8575 ConstructorInitRequiresZeroInit = true;
8576 } else if (Kind.getKind() == InitializationKind::IK_Value &&
8577 S.getLangOpts().CPlusPlus &&
8578 !Kind.isImplicitValueInit()) {
8579 TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo();
8580 if (!TSInfo)
8581 TSInfo = S.Context.getTrivialTypeSourceInfo(Step->Type,
8582 Kind.getRange().getBegin());
8583
8584 CurInit = new (S.Context) CXXScalarValueInitExpr(
8585 Entity.getType().getNonLValueExprType(S.Context), TSInfo,
8586 Kind.getRange().getEnd());
8587 } else {
8588 CurInit = new (S.Context) ImplicitValueInitExpr(Step->Type);
8589 }
8590 break;
8591 }
8592
8593 case SK_CAssignment: {
8594 QualType SourceType = CurInit.get()->getType();
8595
8596 // Save off the initial CurInit in case we need to emit a diagnostic
8597 ExprResult InitialCurInit = CurInit;
8598 ExprResult Result = CurInit;
8599 Sema::AssignConvertType ConvTy =
8600 S.CheckSingleAssignmentConstraints(Step->Type, Result, true,
8601 Entity.getKind() == InitializedEntity::EK_Parameter_CF_Audited);
8602 if (Result.isInvalid())
8603 return ExprError();
8604 CurInit = Result;
8605
8606 // If this is a call, allow conversion to a transparent union.
8607 ExprResult CurInitExprRes = CurInit;
8608 if (ConvTy != Sema::Compatible &&
8609 Entity.isParameterKind() &&
8610 S.CheckTransparentUnionArgumentConstraints(Step->Type, CurInitExprRes)
8611 == Sema::Compatible)
8612 ConvTy = Sema::Compatible;
8613 if (CurInitExprRes.isInvalid())
8614 return ExprError();
8615 CurInit = CurInitExprRes;
8616
8617 bool Complained;
8618 if (S.DiagnoseAssignmentResult(ConvTy, Kind.getLocation(),
8619 Step->Type, SourceType,
8620 InitialCurInit.get(),
8621 getAssignmentAction(Entity, true),
8622 &Complained)) {
8623 PrintInitLocationNote(S, Entity);
8624 return ExprError();
8625 } else if (Complained)
8626 PrintInitLocationNote(S, Entity);
8627 break;
8628 }
8629
8630 case SK_StringInit: {
8631 QualType Ty = Step->Type;
8632 bool UpdateType = ResultType && Entity.getType()->isIncompleteArrayType();
8633 CheckStringInit(CurInit.get(), UpdateType ? *ResultType : Ty,
8634 S.Context.getAsArrayType(Ty), S);
8635 break;
8636 }
8637
8638 case SK_ObjCObjectConversion:
8639 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
8640 CK_ObjCObjectLValueCast,
8641 CurInit.get()->getValueKind());
8642 break;
8643
8644 case SK_ArrayLoopIndex: {
8645 Expr *Cur = CurInit.get();
8646 Expr *BaseExpr = new (S.Context)
8647 OpaqueValueExpr(Cur->getExprLoc(), Cur->getType(),
8648 Cur->getValueKind(), Cur->getObjectKind(), Cur);
8649 Expr *IndexExpr =
8650 new (S.Context) ArrayInitIndexExpr(S.Context.getSizeType());
8651 CurInit = S.CreateBuiltinArraySubscriptExpr(
8652 BaseExpr, Kind.getLocation(), IndexExpr, Kind.getLocation());
8653 ArrayLoopCommonExprs.push_back(BaseExpr);
8654 break;
8655 }
8656
8657 case SK_ArrayLoopInit: {
8658 assert(!ArrayLoopCommonExprs.empty() &&((void)0)
8659 "mismatched SK_ArrayLoopIndex and SK_ArrayLoopInit")((void)0);
8660 Expr *Common = ArrayLoopCommonExprs.pop_back_val();
8661 CurInit = new (S.Context) ArrayInitLoopExpr(Step->Type, Common,
8662 CurInit.get());
8663 break;
8664 }
8665
8666 case SK_GNUArrayInit:
8667 // Okay: we checked everything before creating this step. Note that
8668 // this is a GNU extension.
8669 S.Diag(Kind.getLocation(), diag::ext_array_init_copy)
8670 << Step->Type << CurInit.get()->getType()
8671 << CurInit.get()->getSourceRange();
8672 updateGNUCompoundLiteralRValue(CurInit.get());
8673 LLVM_FALLTHROUGH[[gnu::fallthrough]];
8674 case SK_ArrayInit:
8675 // If the destination type is an incomplete array type, update the
8676 // type accordingly.
8677 if (ResultType) {
8678 if (const IncompleteArrayType *IncompleteDest
8679 = S.Context.getAsIncompleteArrayType(Step->Type)) {
8680 if (const ConstantArrayType *ConstantSource
8681 = S.Context.getAsConstantArrayType(CurInit.get()->getType())) {
8682 *ResultType = S.Context.getConstantArrayType(
8683 IncompleteDest->getElementType(),
8684 ConstantSource->getSize(),
8685 ConstantSource->getSizeExpr(),
8686 ArrayType::Normal, 0);
8687 }
8688 }
8689 }
8690 break;
8691
8692 case SK_ParenthesizedArrayInit:
8693 // Okay: we checked everything before creating this step. Note that
8694 // this is a GNU extension.
8695 S.Diag(Kind.getLocation(), diag::ext_array_init_parens)
8696 << CurInit.get()->getSourceRange();
8697 break;
8698
8699 case SK_PassByIndirectCopyRestore:
8700 case SK_PassByIndirectRestore:
8701 checkIndirectCopyRestoreSource(S, CurInit.get());
8702 CurInit = new (S.Context) ObjCIndirectCopyRestoreExpr(
8703 CurInit.get(), Step->Type,
8704 Step->Kind == SK_PassByIndirectCopyRestore);
8705 break;
8706
8707 case SK_ProduceObjCObject:
8708 CurInit = ImplicitCastExpr::Create(
8709 S.Context, Step->Type, CK_ARCProduceObject, CurInit.get(), nullptr,
8710 VK_PRValue, FPOptionsOverride());
8711 break;
8712
8713 case SK_StdInitializerList: {
8714 S.Diag(CurInit.get()->getExprLoc(),
8715 diag::warn_cxx98_compat_initializer_list_init)
8716 << CurInit.get()->getSourceRange();
8717
8718 // Materialize the temporary into memory.
8719 MaterializeTemporaryExpr *MTE = S.CreateMaterializeTemporaryExpr(
8720 CurInit.get()->getType(), CurInit.get(),
8721 /*BoundToLvalueReference=*/false);
8722
8723 // Wrap it in a construction of a std::initializer_list<T>.
8724 CurInit = new (S.Context) CXXStdInitializerListExpr(Step->Type, MTE);
8725
8726 // Bind the result, in case the library has given initializer_list a
8727 // non-trivial destructor.
8728 if (shouldBindAsTemporary(Entity))
8729 CurInit = S.MaybeBindToTemporary(CurInit.get());
8730 break;
8731 }
8732
8733 case SK_OCLSamplerInit: {
8734 // Sampler initialization have 5 cases:
8735 // 1. function argument passing
8736 // 1a. argument is a file-scope variable
8737 // 1b. argument is a function-scope variable
8738 // 1c. argument is one of caller function's parameters
8739 // 2. variable initialization
8740 // 2a. initializing a file-scope variable
8741 // 2b. initializing a function-scope variable
8742 //
8743 // For file-scope variables, since they cannot be initialized by function
8744 // call of __translate_sampler_initializer in LLVM IR, their references
8745 // need to be replaced by a cast from their literal initializers to
8746 // sampler type. Since sampler variables can only be used in function
8747 // calls as arguments, we only need to replace them when handling the
8748 // argument passing.
8749 assert(Step->Type->isSamplerT() &&((void)0)
8750 "Sampler initialization on non-sampler type.")((void)0);
8751 Expr *Init = CurInit.get()->IgnoreParens();
8752 QualType SourceType = Init->getType();
8753 // Case 1
8754 if (Entity.isParameterKind()) {
8755 if (!SourceType->isSamplerT() && !SourceType->isIntegerType()) {
8756 S.Diag(Kind.getLocation(), diag::err_sampler_argument_required)
8757 << SourceType;
8758 break;
8759 } else if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Init)) {
8760 auto Var = cast<VarDecl>(DRE->getDecl());
8761 // Case 1b and 1c
8762 // No cast from integer to sampler is needed.
8763 if (!Var->hasGlobalStorage()) {
8764 CurInit = ImplicitCastExpr::Create(
8765 S.Context, Step->Type, CK_LValueToRValue, Init,
8766 /*BasePath=*/nullptr, VK_PRValue, FPOptionsOverride());
8767 break;
8768 }
8769 // Case 1a
8770 // For function call with a file-scope sampler variable as argument,
8771 // get the integer literal.
8772 // Do not diagnose if the file-scope variable does not have initializer
8773 // since this has already been diagnosed when parsing the variable
8774 // declaration.
8775 if (!Var->getInit() || !isa<ImplicitCastExpr>(Var->getInit()))
8776 break;
8777 Init = cast<ImplicitCastExpr>(const_cast<Expr*>(
8778 Var->getInit()))->getSubExpr();
8779 SourceType = Init->getType();
8780 }
8781 } else {
8782 // Case 2
8783 // Check initializer is 32 bit integer constant.
8784 // If the initializer is taken from global variable, do not diagnose since
8785 // this has already been done when parsing the variable declaration.
8786 if (!Init->isConstantInitializer(S.Context, false))
8787 break;
8788
8789 if (!SourceType->isIntegerType() ||
8790 32 != S.Context.getIntWidth(SourceType)) {
8791 S.Diag(Kind.getLocation(), diag::err_sampler_initializer_not_integer)
8792 << SourceType;
8793 break;
8794 }
8795
8796 Expr::EvalResult EVResult;
8797 Init->EvaluateAsInt(EVResult, S.Context);
8798 llvm::APSInt Result = EVResult.Val.getInt();
8799 const uint64_t SamplerValue = Result.getLimitedValue();
8800 // 32-bit value of sampler's initializer is interpreted as
8801 // bit-field with the following structure:
8802 // |unspecified|Filter|Addressing Mode| Normalized Coords|
8803 // |31 6|5 4|3 1| 0|
8804 // This structure corresponds to enum values of sampler properties
8805 // defined in SPIR spec v1.2 and also opencl-c.h
8806 unsigned AddressingMode = (0x0E & SamplerValue) >> 1;
8807 unsigned FilterMode = (0x30 & SamplerValue) >> 4;
8808 if (FilterMode != 1 && FilterMode != 2 &&
8809 !S.getOpenCLOptions().isAvailableOption(
8810 "cl_intel_device_side_avc_motion_estimation", S.getLangOpts()))
8811 S.Diag(Kind.getLocation(),
8812 diag::warn_sampler_initializer_invalid_bits)
8813 << "Filter Mode";
8814 if (AddressingMode > 4)
8815 S.Diag(Kind.getLocation(),
8816 diag::warn_sampler_initializer_invalid_bits)
8817 << "Addressing Mode";
8818 }
8819
8820 // Cases 1a, 2a and 2b
8821 // Insert cast from integer to sampler.
8822 CurInit = S.ImpCastExprToType(Init, S.Context.OCLSamplerTy,
8823 CK_IntToOCLSampler);
8824 break;
8825 }
8826 case SK_OCLZeroOpaqueType: {
8827 assert((Step->Type->isEventT() || Step->Type->isQueueT() ||((void)0)
8828 Step->Type->isOCLIntelSubgroupAVCType()) &&((void)0)
8829 "Wrong type for initialization of OpenCL opaque type.")((void)0);
8830
8831 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
8832 CK_ZeroToOCLOpaqueType,
8833 CurInit.get()->getValueKind());
8834 break;
8835 }
8836 }
8837 }
8838
8839 // Check whether the initializer has a shorter lifetime than the initialized
8840 // entity, and if not, either lifetime-extend or warn as appropriate.
8841 if (auto *Init = CurInit.get())
8842 S.checkInitializerLifetime(Entity, Init);
8843
8844 // Diagnose non-fatal problems with the completed initialization.
8845 if (Entity.getKind() == InitializedEntity::EK_Member &&
8846 cast<FieldDecl>(Entity.getDecl())->isBitField())
8847 S.CheckBitFieldInitialization(Kind.getLocation(),
8848 cast<FieldDecl>(Entity.getDecl()),
8849 CurInit.get());
8850
8851 // Check for std::move on construction.
8852 if (const Expr *E = CurInit.get()) {
8853 CheckMoveOnConstruction(S, E,
8854 Entity.getKind() == InitializedEntity::EK_Result);
8855 }
8856
8857 return CurInit;
8858}
8859
8860/// Somewhere within T there is an uninitialized reference subobject.
8861/// Dig it out and diagnose it.
8862static bool DiagnoseUninitializedReference(Sema &S, SourceLocation Loc,
8863 QualType T) {
8864 if (T->isReferenceType()) {
8865 S.Diag(Loc, diag::err_reference_without_init)
8866 << T.getNonReferenceType();
8867 return true;
8868 }
8869
8870 CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
8871 if (!RD || !RD->hasUninitializedReferenceMember())
8872 return false;
8873
8874 for (const auto *FI : RD->fields()) {
8875 if (FI->isUnnamedBitfield())
8876 continue;
8877
8878 if (DiagnoseUninitializedReference(S, FI->getLocation(), FI->getType())) {
8879 S.Diag(Loc, diag::note_value_initialization_here) << RD;
8880 return true;
8881 }
8882 }
8883
8884 for (const auto &BI : RD->bases()) {
8885 if (DiagnoseUninitializedReference(S, BI.getBeginLoc(), BI.getType())) {
8886 S.Diag(Loc, diag::note_value_initialization_here) << RD;
8887 return true;
8888 }
8889 }
8890
8891 return false;
8892}
8893
8894
8895//===----------------------------------------------------------------------===//
8896// Diagnose initialization failures
8897//===----------------------------------------------------------------------===//
8898
8899/// Emit notes associated with an initialization that failed due to a
8900/// "simple" conversion failure.
8901static void emitBadConversionNotes(Sema &S, const InitializedEntity &entity,
8902 Expr *op) {
8903 QualType destType = entity.getType();
8904 if (destType.getNonReferenceType()->isObjCObjectPointerType() &&
8905 op->getType()->isObjCObjectPointerType()) {
8906
8907 // Emit a possible note about the conversion failing because the
8908 // operand is a message send with a related result type.
8909 S.EmitRelatedResultTypeNote(op);
8910
8911 // Emit a possible note about a return failing because we're
8912 // expecting a related result type.
8913 if (entity.getKind() == InitializedEntity::EK_Result)
8914 S.EmitRelatedResultTypeNoteForReturn(destType);
8915 }
8916 QualType fromType = op->getType();
8917 auto *fromDecl = fromType.getTypePtr()->getPointeeCXXRecordDecl();
8918 auto *destDecl = destType.getTypePtr()->getPointeeCXXRecordDecl();
8919 if (fromDecl && destDecl && fromDecl->getDeclKind() == Decl::CXXRecord &&
8920 destDecl->getDeclKind() == Decl::CXXRecord &&
8921 !fromDecl->isInvalidDecl() && !destDecl->isInvalidDecl() &&
8922 !fromDecl->hasDefinition())
8923 S.Diag(fromDecl->getLocation(), diag::note_forward_class_conversion)
8924 << S.getASTContext().getTagDeclType(fromDecl)
8925 << S.getASTContext().getTagDeclType(destDecl);
8926}
8927
8928static void diagnoseListInit(Sema &S, const InitializedEntity &Entity,
8929 InitListExpr *InitList) {
8930 QualType DestType = Entity.getType();
8931
8932 QualType E;
8933 if (S.getLangOpts().CPlusPlus11 && S.isStdInitializerList(DestType, &E)) {
8934 QualType ArrayType = S.Context.getConstantArrayType(
8935 E.withConst(),
8936 llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
8937 InitList->getNumInits()),
8938 nullptr, clang::ArrayType::Normal, 0);
8939 InitializedEntity HiddenArray =
8940 InitializedEntity::InitializeTemporary(ArrayType);
8941 return diagnoseListInit(S, HiddenArray, InitList);
8942 }
8943
8944 if (DestType->isReferenceType()) {
8945 // A list-initialization failure for a reference means that we tried to
8946 // create a temporary of the inner type (per [dcl.init.list]p3.6) and the
8947 // inner initialization failed.
8948 QualType T = DestType->castAs<ReferenceType>()->getPointeeType();
8949 diagnoseListInit(S, InitializedEntity::InitializeTemporary(T), InitList);
8950 SourceLocation Loc = InitList->getBeginLoc();
8951 if (auto *D = Entity.getDecl())
8952 Loc = D->getLocation();
8953 S.Diag(Loc, diag::note_in_reference_temporary_list_initializer) << T;
8954 return;
8955 }
8956
8957 InitListChecker DiagnoseInitList(S, Entity, InitList, DestType,
8958 /*VerifyOnly=*/false,
8959 /*TreatUnavailableAsInvalid=*/false);
8960 assert(DiagnoseInitList.HadError() &&((void)0)
8961 "Inconsistent init list check result.")((void)0);
8962}
8963
8964bool InitializationSequence::Diagnose(Sema &S,
8965 const InitializedEntity &Entity,
8966 const InitializationKind &Kind,
8967 ArrayRef<Expr *> Args) {
8968 if (!Failed())
8969 return false;
8970
8971 // When we want to diagnose only one element of a braced-init-list,
8972 // we need to factor it out.
8973 Expr *OnlyArg;
8974 if (Args.size() == 1) {
8975 auto *List = dyn_cast<InitListExpr>(Args[0]);
8976 if (List && List->getNumInits() == 1)
8977 OnlyArg = List->getInit(0);
8978 else
8979 OnlyArg = Args[0];
8980 }
8981 else
8982 OnlyArg = nullptr;
8983
8984 QualType DestType = Entity.getType();
8985 switch (Failure) {
8986 case FK_TooManyInitsForReference:
8987 // FIXME: Customize for the initialized entity?
8988 if (Args.empty()) {
8989 // Dig out the reference subobject which is uninitialized and diagnose it.
8990 // If this is value-initialization, this could be nested some way within
8991 // the target type.
8992 assert(Kind.getKind() == InitializationKind::IK_Value ||((void)0)
8993 DestType->isReferenceType())((void)0);
8994 bool Diagnosed =
8995 DiagnoseUninitializedReference(S, Kind.getLocation(), DestType);
8996 assert(Diagnosed && "couldn't find uninitialized reference to diagnose")((void)0);
8997 (void)Diagnosed;
8998 } else // FIXME: diagnostic below could be better!
8999 S.Diag(Kind.getLocation(), diag::err_reference_has_multiple_inits)
9000 << SourceRange(Args.front()->getBeginLoc(), Args.back()->getEndLoc());
9001 break;
9002 case FK_ParenthesizedListInitForReference:
9003 S.Diag(Kind.getLocation(), diag::err_list_init_in_parens)
9004 << 1 << Entity.getType() << Args[0]->getSourceRange();
9005 break;
9006
9007 case FK_ArrayNeedsInitList:
9008 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 0;
9009 break;
9010 case FK_ArrayNeedsInitListOrStringLiteral:
9011 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 1;
9012 break;
9013 case FK_ArrayNeedsInitListOrWideStringLiteral:
9014 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 2;
9015 break;
9016 case FK_NarrowStringIntoWideCharArray:
9017 S.Diag(Kind.getLocation(), diag::err_array_init_narrow_string_into_wchar);
9018 break;
9019 case FK_WideStringIntoCharArray:
9020 S.Diag(Kind.getLocation(), diag::err_array_init_wide_string_into_char);
9021 break;
9022 case FK_IncompatWideStringIntoWideChar:
9023 S.Diag(Kind.getLocation(),
9024 diag::err_array_init_incompat_wide_string_into_wchar);
9025 break;
9026 case FK_PlainStringIntoUTF8Char:
9027 S.Diag(Kind.getLocation(),
9028 diag::err_array_init_plain_string_into_char8_t);
9029 S.Diag(Args.front()->getBeginLoc(),
9030 diag::note_array_init_plain_string_into_char8_t)
9031 << FixItHint::CreateInsertion(Args.front()->getBeginLoc(), "u8");
9032 break;
9033 case FK_UTF8StringIntoPlainChar:
9034 S.Diag(Kind.getLocation(),
9035 diag::err_array_init_utf8_string_into_char)
9036 << S.getLangOpts().CPlusPlus20;
9037 break;
9038 case FK_ArrayTypeMismatch:
9039 case FK_NonConstantArrayInit:
9040 S.Diag(Kind.getLocation(),
9041 (Failure == FK_ArrayTypeMismatch
9042 ? diag::err_array_init_different_type
9043 : diag::err_array_init_non_constant_array))
9044 << DestType.getNonReferenceType()
9045 << OnlyArg->getType()
9046 << Args[0]->getSourceRange();
9047 break;
9048
9049 case FK_VariableLengthArrayHasInitializer:
9050 S.Diag(Kind.getLocation(), diag::err_variable_object_no_init)
9051 << Args[0]->getSourceRange();
9052 break;
9053
9054 case FK_AddressOfOverloadFailed: {
9055 DeclAccessPair Found;
9056 S.ResolveAddressOfOverloadedFunction(OnlyArg,
9057 DestType.getNonReferenceType(),
9058 true,
9059 Found);
9060 break;
9061 }
9062
9063 case FK_AddressOfUnaddressableFunction: {
9064 auto *FD = cast<FunctionDecl>(cast<DeclRefExpr>(OnlyArg)->getDecl());
9065 S.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
9066 OnlyArg->getBeginLoc());
9067 break;
9068 }
9069
9070 case FK_ReferenceInitOverloadFailed:
9071 case FK_UserConversionOverloadFailed:
9072 switch (FailedOverloadResult) {
9073 case OR_Ambiguous:
9074
9075 FailedCandidateSet.NoteCandidates(
9076 PartialDiagnosticAt(
9077 Kind.getLocation(),
9078 Failure == FK_UserConversionOverloadFailed
9079 ? (S.PDiag(diag::err_typecheck_ambiguous_condition)
9080 << OnlyArg->getType() << DestType
9081 << Args[0]->getSourceRange())
9082 : (S.PDiag(diag::err_ref_init_ambiguous)
9083 << DestType << OnlyArg->getType()
9084 << Args[0]->getSourceRange())),
9085 S, OCD_AmbiguousCandidates, Args);
9086 break;
9087
9088 case OR_No_Viable_Function: {
9089 auto Cands = FailedCandidateSet.CompleteCandidates(S, OCD_AllCandidates, Args);
9090 if (!S.RequireCompleteType(Kind.getLocation(),
9091 DestType.getNonReferenceType(),
9092 diag::err_typecheck_nonviable_condition_incomplete,
9093 OnlyArg->getType(), Args[0]->getSourceRange()))
9094 S.Diag(Kind.getLocation(), diag::err_typecheck_nonviable_condition)
9095 << (Entity.getKind() == InitializedEntity::EK_Result)
9096 << OnlyArg->getType() << Args[0]->getSourceRange()
9097 << DestType.getNonReferenceType();
9098
9099 FailedCandidateSet.NoteCandidates(S, Args, Cands);
9100 break;
9101 }
9102 case OR_Deleted: {
9103 S.Diag(Kind.getLocation(), diag::err_typecheck_deleted_function)
9104 << OnlyArg->getType() << DestType.getNonReferenceType()
9105 << Args[0]->getSourceRange();
9106 OverloadCandidateSet::iterator Best;
9107 OverloadingResult Ovl
9108 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best);
9109 if (Ovl == OR_Deleted) {
9110 S.NoteDeletedFunction(Best->Function);
9111 } else {
9112 llvm_unreachable("Inconsistent overload resolution?")__builtin_unreachable();
9113 }
9114 break;
9115 }
9116
9117 case OR_Success:
9118 llvm_unreachable("Conversion did not fail!")__builtin_unreachable();
9119 }
9120 break;
9121
9122 case FK_NonConstLValueReferenceBindingToTemporary:
9123 if (isa<InitListExpr>(Args[0])) {
9124 S.Diag(Kind.getLocation(),
9125 diag::err_lvalue_reference_bind_to_initlist)
9126 << DestType.getNonReferenceType().isVolatileQualified()
9127 << DestType.getNonReferenceType()
9128 << Args[0]->getSourceRange();
9129 break;
9130 }
9131 LLVM_FALLTHROUGH[[gnu::fallthrough]];
9132
9133 case FK_NonConstLValueReferenceBindingToUnrelated:
9134 S.Diag(Kind.getLocation(),
9135 Failure == FK_NonConstLValueReferenceBindingToTemporary
9136 ? diag::err_lvalue_reference_bind_to_temporary
9137 : diag::err_lvalue_reference_bind_to_unrelated)
9138 << DestType.getNonReferenceType().isVolatileQualified()
9139 << DestType.getNonReferenceType()
9140 << OnlyArg->getType()
9141 << Args[0]->getSourceRange();
9142 break;
9143
9144 case FK_NonConstLValueReferenceBindingToBitfield: {
9145 // We don't necessarily have an unambiguous source bit-field.
9146 FieldDecl *BitField = Args[0]->getSourceBitField();
9147 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_bitfield)
9148 << DestType.isVolatileQualified()
9149 << (BitField ? BitField->getDeclName() : DeclarationName())
9150 << (BitField != nullptr)
9151 << Args[0]->getSourceRange();
9152 if (BitField)
9153 S.Diag(BitField->getLocation(), diag::note_bitfield_decl);
9154 break;
9155 }
9156
9157 case FK_NonConstLValueReferenceBindingToVectorElement:
9158 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_vector_element)
9159 << DestType.isVolatileQualified()
9160 << Args[0]->getSourceRange();
9161 break;
9162
9163 case FK_NonConstLValueReferenceBindingToMatrixElement:
9164 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_matrix_element)
9165 << DestType.isVolatileQualified() << Args[0]->getSourceRange();
9166 break;
9167
9168 case FK_RValueReferenceBindingToLValue:
9169 S.Diag(Kind.getLocation(), diag::err_lvalue_to_rvalue_ref)
9170 << DestType.getNonReferenceType() << OnlyArg->getType()
9171 << Args[0]->getSourceRange();
9172 break;
9173
9174 case FK_ReferenceAddrspaceMismatchTemporary:
9175 S.Diag(Kind.getLocation(), diag::err_reference_bind_temporary_addrspace)
9176 << DestType << Args[0]->getSourceRange();
9177 break;
9178
9179 case FK_ReferenceInitDropsQualifiers: {
9180 QualType SourceType = OnlyArg->getType();
9181 QualType NonRefType = DestType.getNonReferenceType();
9182 Qualifiers DroppedQualifiers =
9183 SourceType.getQualifiers() - NonRefType.getQualifiers();
9184
9185 if (!NonRefType.getQualifiers().isAddressSpaceSupersetOf(
9186 SourceType.getQualifiers()))
9187 S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
9188 << NonRefType << SourceType << 1 /*addr space*/
9189 << Args[0]->getSourceRange();
9190 else if (DroppedQualifiers.hasQualifiers())
9191 S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
9192 << NonRefType << SourceType << 0 /*cv quals*/
9193 << Qualifiers::fromCVRMask(DroppedQualifiers.getCVRQualifiers())
9194 << DroppedQualifiers.getCVRQualifiers() << Args[0]->getSourceRange();
9195 else
9196 // FIXME: Consider decomposing the type and explaining which qualifiers
9197 // were dropped where, or on which level a 'const' is missing, etc.
9198 S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
9199 << NonRefType << SourceType << 2 /*incompatible quals*/
9200 << Args[0]->getSourceRange();
9201 break;
9202 }
9203
9204 case FK_ReferenceInitFailed:
9205 S.Diag(Kind.getLocation(), diag::err_reference_bind_failed)
9206 << DestType.getNonReferenceType()
9207 << DestType.getNonReferenceType()->isIncompleteType()
9208 << OnlyArg->isLValue()
9209 << OnlyArg->getType()
9210 << Args[0]->getSourceRange();
9211 emitBadConversionNotes(S, Entity, Args[0]);
9212 break;
9213
9214 case FK_ConversionFailed: {
9215 QualType FromType = OnlyArg->getType();
9216 PartialDiagnostic PDiag = S.PDiag(diag::err_init_conversion_failed)
9217 << (int)Entity.getKind()
9218 << DestType
9219 << OnlyArg->isLValue()
9220 << FromType
9221 << Args[0]->getSourceRange();
9222 S.HandleFunctionTypeMismatch(PDiag, FromType, DestType);
9223 S.Diag(Kind.getLocation(), PDiag);
9224 emitBadConversionNotes(S, Entity, Args[0]);
9225 break;
9226 }
9227
9228 case FK_ConversionFromPropertyFailed:
9229 // No-op. This error has already been reported.
9230 break;
9231
9232 case FK_TooManyInitsForScalar: {
9233 SourceRange R;
9234
9235 auto *InitList = dyn_cast<InitListExpr>(Args[0]);
9236 if (InitList && InitList->getNumInits() >= 1) {
9237 R = SourceRange(InitList->getInit(0)->getEndLoc(), InitList->getEndLoc());
9238 } else {
9239 assert(Args.size() > 1 && "Expected multiple initializers!")((void)0);
9240 R = SourceRange(Args.front()->getEndLoc(), Args.back()->getEndLoc());
9241 }
9242
9243 R.setBegin(S.getLocForEndOfToken(R.getBegin()));
9244 if (Kind.isCStyleOrFunctionalCast())
9245 S.Diag(Kind.getLocation(), diag::err_builtin_func_cast_more_than_one_arg)
9246 << R;
9247 else
9248 S.Diag(Kind.getLocation(), diag::err_excess_initializers)
9249 << /*scalar=*/2 << R;
9250 break;
9251 }
9252
9253 case FK_ParenthesizedListInitForScalar:
9254 S.Diag(Kind.getLocation(), diag::err_list_init_in_parens)
9255 << 0 << Entity.getType() << Args[0]->getSourceRange();
9256 break;
9257
9258 case FK_ReferenceBindingToInitList:
9259 S.Diag(Kind.getLocation(), diag::err_reference_bind_init_list)
9260 << DestType.getNonReferenceType() << Args[0]->getSourceRange();
9261 break;
9262
9263 case FK_InitListBadDestinationType:
9264 S.Diag(Kind.getLocation(), diag::err_init_list_bad_dest_type)
9265 << (DestType->isRecordType()) << DestType << Args[0]->getSourceRange();
9266 break;
9267
9268 case FK_ListConstructorOverloadFailed:
9269 case FK_ConstructorOverloadFailed: {
9270 SourceRange ArgsRange;
9271 if (Args.size())
9272 ArgsRange =
9273 SourceRange(Args.front()->getBeginLoc(), Args.back()->getEndLoc());
9274
9275 if (Failure == FK_ListConstructorOverloadFailed) {
9276 assert(Args.size() == 1 &&((void)0)
9277 "List construction from other than 1 argument.")((void)0);
9278 InitListExpr *InitList = cast<InitListExpr>(Args[0]);
9279 Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
9280 }
9281
9282 // FIXME: Using "DestType" for the entity we're printing is probably
9283 // bad.
9284 switch (FailedOverloadResult) {
9285 case OR_Ambiguous:
9286 FailedCandidateSet.NoteCandidates(
9287 PartialDiagnosticAt(Kind.getLocation(),
9288 S.PDiag(diag::err_ovl_ambiguous_init)
9289 << DestType << ArgsRange),
9290 S, OCD_AmbiguousCandidates, Args);
9291 break;
9292
9293 case OR_No_Viable_Function:
9294 if (Kind.getKind() == InitializationKind::IK_Default &&
9295 (Entity.getKind() == InitializedEntity::EK_Base ||
9296 Entity.getKind() == InitializedEntity::EK_Member) &&
9297 isa<CXXConstructorDecl>(S.CurContext)) {
9298 // This is implicit default initialization of a member or
9299 // base within a constructor. If no viable function was
9300 // found, notify the user that they need to explicitly
9301 // initialize this base/member.
9302 CXXConstructorDecl *Constructor
9303 = cast<CXXConstructorDecl>(S.CurContext);
9304 const CXXRecordDecl *InheritedFrom = nullptr;
9305 if (auto Inherited = Constructor->getInheritedConstructor())
9306 InheritedFrom = Inherited.getShadowDecl()->getNominatedBaseClass();
9307 if (Entity.getKind() == InitializedEntity::EK_Base) {
9308 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor)
9309 << (InheritedFrom ? 2 : Constructor->isImplicit() ? 1 : 0)
9310 << S.Context.getTypeDeclType(Constructor->getParent())
9311 << /*base=*/0
9312 << Entity.getType()
9313 << InheritedFrom;
9314
9315 RecordDecl *BaseDecl
9316 = Entity.getBaseSpecifier()->getType()->castAs<RecordType>()
9317 ->getDecl();
9318 S.Diag(BaseDecl->getLocation(), diag::note_previous_decl)
9319 << S.Context.getTagDeclType(BaseDecl);
9320 } else {
9321 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor)
9322 << (InheritedFrom ? 2 : Constructor->isImplicit() ? 1 : 0)
9323 << S.Context.getTypeDeclType(Constructor->getParent())
9324 << /*member=*/1
9325 << Entity.getName()
9326 << InheritedFrom;
9327 S.Diag(Entity.getDecl()->getLocation(),
9328 diag::note_member_declared_at);
9329
9330 if (const RecordType *Record
9331 = Entity.getType()->getAs<RecordType>())
9332 S.Diag(Record->getDecl()->getLocation(),
9333 diag::note_previous_decl)
9334 << S.Context.getTagDeclType(Record->getDecl());
9335 }
9336 break;
9337 }
9338
9339 FailedCandidateSet.NoteCandidates(
9340 PartialDiagnosticAt(
9341 Kind.getLocation(),
9342 S.PDiag(diag::err_ovl_no_viable_function_in_init)
9343 << DestType << ArgsRange),
9344 S, OCD_AllCandidates, Args);
9345 break;
9346
9347 case OR_Deleted: {
9348 OverloadCandidateSet::iterator Best;
9349 OverloadingResult Ovl
9350 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best);
9351 if (Ovl != OR_Deleted) {
9352 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init)
9353 << DestType << ArgsRange;
9354 llvm_unreachable("Inconsistent overload resolution?")__builtin_unreachable();
9355 break;
9356 }
9357
9358 // If this is a defaulted or implicitly-declared function, then
9359 // it was implicitly deleted. Make it clear that the deletion was
9360 // implicit.
9361 if (S.isImplicitlyDeleted(Best->Function))
9362 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_special_init)
9363 << S.getSpecialMember(cast<CXXMethodDecl>(Best->Function))
9364 << DestType << ArgsRange;
9365 else
9366 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init)
9367 << DestType << ArgsRange;
9368
9369 S.NoteDeletedFunction(Best->Function);
9370 break;
9371 }
9372
9373 case OR_Success:
9374 llvm_unreachable("Conversion did not fail!")__builtin_unreachable();
9375 }
9376 }
9377 break;
9378
9379 case FK_DefaultInitOfConst:
9380 if (Entity.getKind() == InitializedEntity::EK_Member &&
9381 isa<CXXConstructorDecl>(S.CurContext)) {
9382 // This is implicit default-initialization of a const member in
9383 // a constructor. Complain that it needs to be explicitly
9384 // initialized.
9385 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(S.CurContext);
9386 S.Diag(Kind.getLocation(), diag::err_uninitialized_member_in_ctor)
9387 << (Constructor->getInheritedConstructor() ? 2 :
9388 Constructor->isImplicit() ? 1 : 0)
9389 << S.Context.getTypeDeclType(Constructor->getParent())
9390 << /*const=*/1
9391 << Entity.getName();
9392 S.Diag(Entity.getDecl()->getLocation(), diag::note_previous_decl)
9393 << Entity.getName();
9394 } else {
9395 S.Diag(Kind.getLocation(), diag::err_default_init_const)
9396 << DestType << (bool)DestType->getAs<RecordType>();
9397 }
9398 break;
9399
9400 case FK_Incomplete:
9401 S.RequireCompleteType(Kind.getLocation(), FailedIncompleteType,
9402 diag::err_init_incomplete_type);
9403 break;
9404
9405 case FK_ListInitializationFailed: {
9406 // Run the init list checker again to emit diagnostics.
9407 InitListExpr *InitList = cast<InitListExpr>(Args[0]);
9408 diagnoseListInit(S, Entity, InitList);
9409 break;
9410 }
9411
9412 case FK_PlaceholderType: {
9413 // FIXME: Already diagnosed!
9414 break;
9415 }
9416
9417 case FK_ExplicitConstructor: {
9418 S.Diag(Kind.getLocation(), diag::err_selected_explicit_constructor)
9419 << Args[0]->getSourceRange();
9420 OverloadCandidateSet::iterator Best;
9421 OverloadingResult Ovl
9422 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best);
9423 (void)Ovl;
9424 assert(Ovl == OR_Success && "Inconsistent overload resolution")((void)0);
9425 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
9426 S.Diag(CtorDecl->getLocation(),
9427 diag::note_explicit_ctor_deduction_guide_here) << false;
9428 break;
9429 }
9430 }
9431
9432 PrintInitLocationNote(S, Entity);
9433 return true;
9434}
9435
9436void InitializationSequence::dump(raw_ostream &OS) const {
9437 switch (SequenceKind) {
9438 case FailedSequence: {
9439 OS << "Failed sequence: ";
9440 switch (Failure) {
9441 case FK_TooManyInitsForReference:
9442 OS << "too many initializers for reference";
9443 break;
9444
9445 case FK_ParenthesizedListInitForReference:
9446 OS << "parenthesized list init for reference";
9447 break;
9448
9449 case FK_ArrayNeedsInitList:
9450 OS << "array requires initializer list";
9451 break;
9452
9453 case FK_AddressOfUnaddressableFunction:
9454 OS << "address of unaddressable function was taken";
9455 break;
9456
9457 case FK_ArrayNeedsInitListOrStringLiteral:
9458 OS << "array requires initializer list or string literal";
9459 break;
9460
9461 case FK_ArrayNeedsInitListOrWideStringLiteral:
9462 OS << "array requires initializer list or wide string literal";
9463 break;
9464
9465 case FK_NarrowStringIntoWideCharArray:
9466 OS << "narrow string into wide char array";
9467 break;
9468
9469 case FK_WideStringIntoCharArray:
9470 OS << "wide string into char array";
9471 break;
9472
9473 case FK_IncompatWideStringIntoWideChar:
9474 OS << "incompatible wide string into wide char array";
9475 break;
9476
9477 case FK_PlainStringIntoUTF8Char:
9478 OS << "plain string literal into char8_t array";
9479 break;
9480
9481 case FK_UTF8StringIntoPlainChar:
9482 OS << "u8 string literal into char array";
9483 break;
9484
9485 case FK_ArrayTypeMismatch:
9486 OS << "array type mismatch";
9487 break;
9488
9489 case FK_NonConstantArrayInit:
9490 OS << "non-constant array initializer";
9491 break;
9492
9493 case FK_AddressOfOverloadFailed:
9494 OS << "address of overloaded function failed";
9495 break;
9496
9497 case FK_ReferenceInitOverloadFailed:
9498 OS << "overload resolution for reference initialization failed";
9499 break;
9500
9501 case FK_NonConstLValueReferenceBindingToTemporary:
9502 OS << "non-const lvalue reference bound to temporary";
9503 break;
9504
9505 case FK_NonConstLValueReferenceBindingToBitfield:
9506 OS << "non-const lvalue reference bound to bit-field";
9507 break;
9508
9509 case FK_NonConstLValueReferenceBindingToVectorElement:
9510 OS << "non-const lvalue reference bound to vector element";
9511 break;
9512
9513 case FK_NonConstLValueReferenceBindingToMatrixElement:
9514 OS << "non-const lvalue reference bound to matrix element";
9515 break;
9516
9517 case FK_NonConstLValueReferenceBindingToUnrelated:
9518 OS << "non-const lvalue reference bound to unrelated type";
9519 break;
9520
9521 case FK_RValueReferenceBindingToLValue:
9522 OS << "rvalue reference bound to an lvalue";
9523 break;
9524
9525 case FK_ReferenceInitDropsQualifiers:
9526 OS << "reference initialization drops qualifiers";
9527 break;
9528
9529 case FK_ReferenceAddrspaceMismatchTemporary:
9530 OS << "reference with mismatching address space bound to temporary";
9531 break;
9532
9533 case FK_ReferenceInitFailed:
9534 OS << "reference initialization failed";
9535 break;
9536
9537 case FK_ConversionFailed:
9538 OS << "conversion failed";
9539 break;
9540
9541 case FK_ConversionFromPropertyFailed:
9542 OS << "conversion from property failed";
9543 break;
9544
9545 case FK_TooManyInitsForScalar:
9546 OS << "too many initializers for scalar";
9547 break;
9548
9549 case FK_ParenthesizedListInitForScalar:
9550 OS << "parenthesized list init for reference";
9551 break;
9552
9553 case FK_ReferenceBindingToInitList:
9554 OS << "referencing binding to initializer list";
9555 break;
9556
9557 case FK_InitListBadDestinationType:
9558 OS << "initializer list for non-aggregate, non-scalar type";
9559 break;
9560
9561 case FK_UserConversionOverloadFailed:
9562 OS << "overloading failed for user-defined conversion";
9563 break;
9564
9565 case FK_ConstructorOverloadFailed:
9566 OS << "constructor overloading failed";
9567 break;
9568
9569 case FK_DefaultInitOfConst:
9570 OS << "default initialization of a const variable";
9571 break;
9572
9573 case FK_Incomplete:
9574 OS << "initialization of incomplete type";
9575 break;
9576
9577 case FK_ListInitializationFailed:
9578 OS << "list initialization checker failure";
9579 break;
9580
9581 case FK_VariableLengthArrayHasInitializer:
9582 OS << "variable length array has an initializer";
9583 break;
9584
9585 case FK_PlaceholderType:
9586 OS << "initializer expression isn't contextually valid";
9587 break;
9588
9589 case FK_ListConstructorOverloadFailed:
9590 OS << "list constructor overloading failed";
9591 break;
9592
9593 case FK_ExplicitConstructor:
9594 OS << "list copy initialization chose explicit constructor";
9595 break;
9596 }
9597 OS << '\n';
9598 return;
9599 }
9600
9601 case DependentSequence:
9602 OS << "Dependent sequence\n";
9603 return;
9604
9605 case NormalSequence:
9606 OS << "Normal sequence: ";
9607 break;
9608 }
9609
9610 for (step_iterator S = step_begin(), SEnd = step_end(); S != SEnd; ++S) {
9611 if (S != step_begin()) {
9612 OS << " -> ";
9613 }
9614
9615 switch (S->Kind) {
9616 case SK_ResolveAddressOfOverloadedFunction:
9617 OS << "resolve address of overloaded function";
9618 break;
9619
9620 case SK_CastDerivedToBasePRValue:
9621 OS << "derived-to-base (prvalue)";
9622 break;
9623
9624 case SK_CastDerivedToBaseXValue:
9625 OS << "derived-to-base (xvalue)";
9626 break;
9627
9628 case SK_CastDerivedToBaseLValue:
9629 OS << "derived-to-base (lvalue)";
9630 break;
9631
9632 case SK_BindReference:
9633 OS << "bind reference to lvalue";
9634 break;
9635
9636 case SK_BindReferenceToTemporary:
9637 OS << "bind reference to a temporary";
9638 break;
9639
9640 case SK_FinalCopy:
9641 OS << "final copy in class direct-initialization";
9642 break;
9643
9644 case SK_ExtraneousCopyToTemporary:
9645 OS << "extraneous C++03 copy to temporary";
9646 break;
9647
9648 case SK_UserConversion:
9649 OS << "user-defined conversion via " << *S->Function.Function;
9650 break;
9651
9652 case SK_QualificationConversionPRValue:
9653 OS << "qualification conversion (prvalue)";
9654 break;
9655
9656 case SK_QualificationConversionXValue:
9657 OS << "qualification conversion (xvalue)";
9658 break;
9659
9660 case SK_QualificationConversionLValue:
9661 OS << "qualification conversion (lvalue)";
9662 break;
9663
9664 case SK_FunctionReferenceConversion:
9665 OS << "function reference conversion";
9666 break;
9667
9668 case SK_AtomicConversion:
9669 OS << "non-atomic-to-atomic conversion";
9670 break;
9671
9672 case SK_ConversionSequence:
9673 OS << "implicit conversion sequence (";
9674 S->ICS->dump(); // FIXME: use OS
9675 OS << ")";
9676 break;
9677
9678 case SK_ConversionSequenceNoNarrowing:
9679 OS << "implicit conversion sequence with narrowing prohibited (";
9680 S->ICS->dump(); // FIXME: use OS
9681 OS << ")";
9682 break;
9683
9684 case SK_ListInitialization:
9685 OS << "list aggregate initialization";
9686 break;
9687
9688 case SK_UnwrapInitList:
9689 OS << "unwrap reference initializer list";
9690 break;
9691
9692 case SK_RewrapInitList:
9693 OS << "rewrap reference initializer list";
9694 break;
9695
9696 case SK_ConstructorInitialization:
9697 OS << "constructor initialization";
9698 break;
9699
9700 case SK_ConstructorInitializationFromList:
9701 OS << "list initialization via constructor";
9702 break;
9703
9704 case SK_ZeroInitialization:
9705 OS << "zero initialization";
9706 break;
9707
9708 case SK_CAssignment:
9709 OS << "C assignment";
9710 break;
9711
9712 case SK_StringInit:
9713 OS << "string initialization";
9714 break;
9715
9716 case SK_ObjCObjectConversion:
9717 OS << "Objective-C object conversion";
9718 break;
9719
9720 case SK_ArrayLoopIndex:
9721 OS << "indexing for array initialization loop";
9722 break;
9723
9724 case SK_ArrayLoopInit:
9725 OS << "array initialization loop";
9726 break;
9727
9728 case SK_ArrayInit:
9729 OS << "array initialization";
9730 break;
9731
9732 case SK_GNUArrayInit:
9733 OS << "array initialization (GNU extension)";
9734 break;
9735
9736 case SK_ParenthesizedArrayInit:
9737 OS << "parenthesized array initialization";
9738 break;
9739
9740 case SK_PassByIndirectCopyRestore:
9741 OS << "pass by indirect copy and restore";
9742 break;
9743
9744 case SK_PassByIndirectRestore:
9745 OS << "pass by indirect restore";
9746 break;
9747
9748 case SK_ProduceObjCObject:
9749 OS << "Objective-C object retension";
9750 break;
9751
9752 case SK_StdInitializerList:
9753 OS << "std::initializer_list from initializer list";
9754 break;
9755
9756 case SK_StdInitializerListConstructorCall:
9757 OS << "list initialization from std::initializer_list";
9758 break;
9759
9760 case SK_OCLSamplerInit:
9761 OS << "OpenCL sampler_t from integer constant";
9762 break;
9763
9764 case SK_OCLZeroOpaqueType:
9765 OS << "OpenCL opaque type from zero";
9766 break;
9767 }
9768
9769 OS << " [" << S->Type.getAsString() << ']';
9770 }
9771
9772 OS << '\n';
9773}
9774
9775void InitializationSequence::dump() const {
9776 dump(llvm::errs());
9777}
9778
9779static bool NarrowingErrs(const LangOptions &L) {
9780 return L.CPlusPlus11 &&
9781 (!L.MicrosoftExt || L.isCompatibleWithMSVC(LangOptions::MSVC2015));
9782}
9783
9784static void DiagnoseNarrowingInInitList(Sema &S,
9785 const ImplicitConversionSequence &ICS,
9786 QualType PreNarrowingType,
9787 QualType EntityType,
9788 const Expr *PostInit) {
9789 const StandardConversionSequence *SCS = nullptr;
9790 switch (ICS.getKind()) {
9791 case ImplicitConversionSequence::StandardConversion:
9792 SCS = &ICS.Standard;
9793 break;
9794 case ImplicitConversionSequence::UserDefinedConversion:
9795 SCS = &ICS.UserDefined.After;
9796 break;
9797 case ImplicitConversionSequence::AmbiguousConversion:
9798 case ImplicitConversionSequence::EllipsisConversion:
9799 case ImplicitConversionSequence::BadConversion:
9800 return;
9801 }
9802
9803 // C++11 [dcl.init.list]p7: Check whether this is a narrowing conversion.
9804 APValue ConstantValue;
9805 QualType ConstantType;
9806 switch (SCS->getNarrowingKind(S.Context, PostInit, ConstantValue,
9807 ConstantType)) {
9808 case NK_Not_Narrowing:
9809 case NK_Dependent_Narrowing:
9810 // No narrowing occurred.
9811 return;
9812
9813 case NK_Type_Narrowing:
9814 // This was a floating-to-integer conversion, which is always considered a
9815 // narrowing conversion even if the value is a constant and can be
9816 // represented exactly as an integer.
9817 S.Diag(PostInit->getBeginLoc(), NarrowingErrs(S.getLangOpts())
9818 ? diag::ext_init_list_type_narrowing
9819 : diag::warn_init_list_type_narrowing)
9820 << PostInit->getSourceRange()
9821 << PreNarrowingType.getLocalUnqualifiedType()
9822 << EntityType.getLocalUnqualifiedType();
9823 break;
9824
9825 case NK_Constant_Narrowing:
9826 // A constant value was narrowed.
9827 S.Diag(PostInit->getBeginLoc(),
9828 NarrowingErrs(S.getLangOpts())
9829 ? diag::ext_init_list_constant_narrowing
9830 : diag::warn_init_list_constant_narrowing)
9831 << PostInit->getSourceRange()
9832 << ConstantValue.getAsString(S.getASTContext(), ConstantType)
9833 << EntityType.getLocalUnqualifiedType();
9834 break;
9835
9836 case NK_Variable_Narrowing:
9837 // A variable's value may have been narrowed.
9838 S.Diag(PostInit->getBeginLoc(),
9839 NarrowingErrs(S.getLangOpts())
9840 ? diag::ext_init_list_variable_narrowing
9841 : diag::warn_init_list_variable_narrowing)
9842 << PostInit->getSourceRange()
9843 << PreNarrowingType.getLocalUnqualifiedType()
9844 << EntityType.getLocalUnqualifiedType();
9845 break;
9846 }
9847
9848 SmallString<128> StaticCast;
9849 llvm::raw_svector_ostream OS(StaticCast);
9850 OS << "static_cast<";
9851 if (const TypedefType *TT = EntityType->getAs<TypedefType>()) {
9852 // It's important to use the typedef's name if there is one so that the
9853 // fixit doesn't break code using types like int64_t.
9854 //
9855 // FIXME: This will break if the typedef requires qualification. But
9856 // getQualifiedNameAsString() includes non-machine-parsable components.
9857 OS << *TT->getDecl();
9858 } else if (const BuiltinType *BT = EntityType->getAs<BuiltinType>())
9859 OS << BT->getName(S.getLangOpts());
9860 else {
9861 // Oops, we didn't find the actual type of the variable. Don't emit a fixit
9862 // with a broken cast.
9863 return;
9864 }
9865 OS << ">(";
9866 S.Diag(PostInit->getBeginLoc(), diag::note_init_list_narrowing_silence)
9867 << PostInit->getSourceRange()
9868 << FixItHint::CreateInsertion(PostInit->getBeginLoc(), OS.str())
9869 << FixItHint::CreateInsertion(
9870 S.getLocForEndOfToken(PostInit->getEndLoc()), ")");
9871}
9872
9873//===----------------------------------------------------------------------===//
9874// Initialization helper functions
9875//===----------------------------------------------------------------------===//
9876bool
9877Sema::CanPerformCopyInitialization(const InitializedEntity &Entity,
9878 ExprResult Init) {
9879 if (Init.isInvalid())
9880 return false;
9881
9882 Expr *InitE = Init.get();
9883 assert(InitE && "No initialization expression")((void)0);
9884
9885 InitializationKind Kind =
9886 InitializationKind::CreateCopy(InitE->getBeginLoc(), SourceLocation());
9887 InitializationSequence Seq(*this, Entity, Kind, InitE);
9888 return !Seq.Failed();
9889}
9890
9891ExprResult
9892Sema::PerformCopyInitialization(const InitializedEntity &Entity,
9893 SourceLocation EqualLoc,
9894 ExprResult Init,
9895 bool TopLevelOfInitList,
9896 bool AllowExplicit) {
9897 if (Init.isInvalid())
9898 return ExprError();
9899
9900 Expr *InitE = Init.get();
9901 assert(InitE && "No initialization expression?")((void)0);
9902
9903 if (EqualLoc.isInvalid())
9904 EqualLoc = InitE->getBeginLoc();
9905
9906 InitializationKind Kind = InitializationKind::CreateCopy(
9907 InitE->getBeginLoc(), EqualLoc, AllowExplicit);
9908 InitializationSequence Seq(*this, Entity, Kind, InitE, TopLevelOfInitList);
9909
9910 // Prevent infinite recursion when performing parameter copy-initialization.
9911 const bool ShouldTrackCopy =
9912 Entity.isParameterKind() && Seq.isConstructorInitialization();
9913 if (ShouldTrackCopy) {
9914 if (llvm::find(CurrentParameterCopyTypes, Entity.getType()) !=
9915 CurrentParameterCopyTypes.end()) {
9916 Seq.SetOverloadFailure(
9917 InitializationSequence::FK_ConstructorOverloadFailed,
9918 OR_No_Viable_Function);
9919
9920 // Try to give a meaningful diagnostic note for the problematic
9921 // constructor.
9922 const auto LastStep = Seq.step_end() - 1;
9923 assert(LastStep->Kind ==((void)0)
9924 InitializationSequence::SK_ConstructorInitialization)((void)0);
9925 const FunctionDecl *Function = LastStep->Function.Function;
9926 auto Candidate =
9927 llvm::find_if(Seq.getFailedCandidateSet(),
9928 [Function](const OverloadCandidate &Candidate) -> bool {
9929 return Candidate.Viable &&
9930 Candidate.Function == Function &&
9931 Candidate.Conversions.size() > 0;
9932 });
9933 if (Candidate != Seq.getFailedCandidateSet().end() &&
9934 Function->getNumParams() > 0) {
9935 Candidate->Viable = false;
9936 Candidate->FailureKind = ovl_fail_bad_conversion;
9937 Candidate->Conversions[0].setBad(BadConversionSequence::no_conversion,
9938 InitE,
9939 Function->getParamDecl(0)->getType());
9940 }
9941 }
9942 CurrentParameterCopyTypes.push_back(Entity.getType());
9943 }
9944
9945 ExprResult Result = Seq.Perform(*this, Entity, Kind, InitE);
9946
9947 if (ShouldTrackCopy)
9948 CurrentParameterCopyTypes.pop_back();
9949
9950 return Result;
9951}
9952
9953/// Determine whether RD is, or is derived from, a specialization of CTD.
9954static bool isOrIsDerivedFromSpecializationOf(CXXRecordDecl *RD,
9955 ClassTemplateDecl *CTD) {
9956 auto NotSpecialization = [&] (const CXXRecordDecl *Candidate) {
9957 auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(Candidate);
9958 return !CTSD || !declaresSameEntity(CTSD->getSpecializedTemplate(), CTD);
9959 };
9960 return !(NotSpecialization(RD) && RD->forallBases(NotSpecialization));
9961}
9962
9963QualType Sema::DeduceTemplateSpecializationFromInitializer(
9964 TypeSourceInfo *TSInfo, const InitializedEntity &Entity,
9965 const InitializationKind &Kind, MultiExprArg Inits) {
9966 auto *DeducedTST = dyn_cast<DeducedTemplateSpecializationType>(
9967 TSInfo->getType()->getContainedDeducedType());
9968 assert(DeducedTST && "not a deduced template specialization type")((void)0);
9969
9970 auto TemplateName = DeducedTST->getTemplateName();
9971 if (TemplateName.isDependent())
9972 return SubstAutoType(TSInfo->getType(), Context.DependentTy);
9973
9974 // We can only perform deduction for class templates.
9975 auto *Template =
9976 dyn_cast_or_null<ClassTemplateDecl>(TemplateName.getAsTemplateDecl());
9977 if (!Template) {
9978 Diag(Kind.getLocation(),
9979 diag::err_deduced_non_class_template_specialization_type)
9980 << (int)getTemplateNameKindForDiagnostics(TemplateName) << TemplateName;
9981 if (auto *TD = TemplateName.getAsTemplateDecl())
9982 Diag(TD->getLocation(), diag::note_template_decl_here);
9983 return QualType();
9984 }
9985
9986 // Can't deduce from dependent arguments.
9987 if (Expr::hasAnyTypeDependentArguments(Inits)) {
9988 Diag(TSInfo->getTypeLoc().getBeginLoc(),
9989 diag::warn_cxx14_compat_class_template_argument_deduction)
9990 << TSInfo->getTypeLoc().getSourceRange() << 0;
9991 return SubstAutoType(TSInfo->getType(), Context.DependentTy);
9992 }
9993
9994 // FIXME: Perform "exact type" matching first, per CWG discussion?
9995 // Or implement this via an implied 'T(T) -> T' deduction guide?
9996
9997 // FIXME: Do we need/want a std::initializer_list<T> special case?
9998
9999 // Look up deduction guides, including those synthesized from constructors.
10000 //
10001 // C++1z [over.match.class.deduct]p1:
10002 // A set of functions and function templates is formed comprising:
10003 // - For each constructor of the class template designated by the
10004 // template-name, a function template [...]
10005 // - For each deduction-guide, a function or function template [...]
10006 DeclarationNameInfo NameInfo(
10007 Context.DeclarationNames.getCXXDeductionGuideName(Template),
10008 TSInfo->getTypeLoc().getEndLoc());
10009 LookupResult Guides(*this, NameInfo, LookupOrdinaryName);
10010 LookupQualifiedName(Guides, Template->getDeclContext());
10011
10012 // FIXME: Do not diagnose inaccessible deduction guides. The standard isn't
10013 // clear on this, but they're not found by name so access does not apply.
10014 Guides.suppressDiagnostics();
10015
10016 // Figure out if this is list-initialization.
10017 InitListExpr *ListInit =
10018 (Inits.size() == 1 && Kind.getKind() != InitializationKind::IK_Direct)
10019 ? dyn_cast<InitListExpr>(Inits[0])
10020 : nullptr;
10021
10022 // C++1z [over.match.class.deduct]p1:
10023 // Initialization and overload resolution are performed as described in
10024 // [dcl.init] and [over.match.ctor], [over.match.copy], or [over.match.list]
10025 // (as appropriate for the type of initialization performed) for an object
10026 // of a hypothetical class type, where the selected functions and function
10027 // templates are considered to be the constructors of that class type
10028 //
10029 // Since we know we're initializing a class type of a type unrelated to that
10030 // of the initializer, this reduces to something fairly reasonable.
10031 OverloadCandidateSet Candidates(Kind.getLocation(),
10032 OverloadCandidateSet::CSK_Normal);
10033 OverloadCandidateSet::iterator Best;
10034
10035 bool HasAnyDeductionGuide = false;
10036 bool AllowExplicit = !Kind.isCopyInit() || ListInit;
10037
10038 auto tryToResolveOverload =
10039 [&](bool OnlyListConstructors) -> OverloadingResult {
10040 Candidates.clear(OverloadCandidateSet::CSK_Normal);
10041 HasAnyDeductionGuide = false;
10042
10043 for (auto I = Guides.begin(), E = Guides.end(); I != E; ++I) {
10044 NamedDecl *D = (*I)->getUnderlyingDecl();
10045 if (D->isInvalidDecl())
10046 continue;
10047
10048 auto *TD = dyn_cast<FunctionTemplateDecl>(D);
10049 auto *GD = dyn_cast_or_null<CXXDeductionGuideDecl>(
10050 TD ? TD->getTemplatedDecl() : dyn_cast<FunctionDecl>(D));
10051 if (!GD)
10052 continue;
10053
10054 if (!GD->isImplicit())
10055 HasAnyDeductionGuide = true;
10056
10057 // C++ [over.match.ctor]p1: (non-list copy-initialization from non-class)
10058 // For copy-initialization, the candidate functions are all the
10059 // converting constructors (12.3.1) of that class.
10060 // C++ [over.match.copy]p1: (non-list copy-initialization from class)
10061 // The converting constructors of T are candidate functions.
10062 if (!AllowExplicit) {
10063 // Overload resolution checks whether the deduction guide is declared
10064 // explicit for us.
10065
10066 // When looking for a converting constructor, deduction guides that
10067 // could never be called with one argument are not interesting to
10068 // check or note.
10069 if (GD->getMinRequiredArguments() > 1 ||
10070 (GD->getNumParams() == 0 && !GD->isVariadic()))
10071 continue;
10072 }
10073
10074 // C++ [over.match.list]p1.1: (first phase list initialization)
10075 // Initially, the candidate functions are the initializer-list
10076 // constructors of the class T
10077 if (OnlyListConstructors && !isInitListConstructor(GD))
10078 continue;
10079
10080 // C++ [over.match.list]p1.2: (second phase list initialization)
10081 // the candidate functions are all the constructors of the class T
10082 // C++ [over.match.ctor]p1: (all other cases)
10083 // the candidate functions are all the constructors of the class of
10084 // the object being initialized
10085
10086 // C++ [over.best.ics]p4:
10087 // When [...] the constructor [...] is a candidate by
10088 // - [over.match.copy] (in all cases)
10089 // FIXME: The "second phase of [over.match.list] case can also
10090 // theoretically happen here, but it's not clear whether we can
10091 // ever have a parameter of the right type.
10092 bool SuppressUserConversions = Kind.isCopyInit();
10093
10094 if (TD)
10095 AddTemplateOverloadCandidate(TD, I.getPair(), /*ExplicitArgs*/ nullptr,
10096 Inits, Candidates, SuppressUserConversions,
10097 /*PartialOverloading*/ false,
10098 AllowExplicit);
10099 else
10100 AddOverloadCandidate(GD, I.getPair(), Inits, Candidates,
10101 SuppressUserConversions,
10102 /*PartialOverloading*/ false, AllowExplicit);
10103 }
10104 return Candidates.BestViableFunction(*this, Kind.getLocation(), Best);
10105 };
10106
10107 OverloadingResult Result = OR_No_Viable_Function;
10108
10109 // C++11 [over.match.list]p1, per DR1467: for list-initialization, first
10110 // try initializer-list constructors.
10111 if (ListInit) {
10112 bool TryListConstructors = true;
10113
10114 // Try list constructors unless the list is empty and the class has one or
10115 // more default constructors, in which case those constructors win.
10116 if (!ListInit->getNumInits()) {
10117 for (NamedDecl *D : Guides) {
10118 auto *FD = dyn_cast<FunctionDecl>(D->getUnderlyingDecl());
10119 if (FD && FD->getMinRequiredArguments() == 0) {
10120 TryListConstructors = false;
10121 break;
10122 }
10123 }
10124 } else if (ListInit->getNumInits() == 1) {
10125 // C++ [over.match.class.deduct]:
10126 // As an exception, the first phase in [over.match.list] (considering
10127 // initializer-list constructors) is omitted if the initializer list
10128 // consists of a single expression of type cv U, where U is a
10129 // specialization of C or a class derived from a specialization of C.
10130 Expr *E = ListInit->getInit(0);
10131 auto *RD = E->getType()->getAsCXXRecordDecl();
10132 if (!isa<InitListExpr>(E) && RD &&
10133 isCompleteType(Kind.getLocation(), E->getType()) &&
10134 isOrIsDerivedFromSpecializationOf(RD, Template))
10135 TryListConstructors = false;
10136 }
10137
10138 if (TryListConstructors)
10139 Result = tryToResolveOverload(/*OnlyListConstructor*/true);
10140 // Then unwrap the initializer list and try again considering all
10141 // constructors.
10142 Inits = MultiExprArg(ListInit->getInits(), ListInit->getNumInits());
10143 }
10144
10145 // If list-initialization fails, or if we're doing any other kind of
10146 // initialization, we (eventually) consider constructors.
10147 if (Result == OR_No_Viable_Function)
10148 Result = tryToResolveOverload(/*OnlyListConstructor*/false);
10149
10150 switch (Result) {
10151 case OR_Ambiguous:
10152 // FIXME: For list-initialization candidates, it'd usually be better to
10153 // list why they were not viable when given the initializer list itself as
10154 // an argument.
10155 Candidates.NoteCandidates(
10156 PartialDiagnosticAt(
10157 Kind.getLocation(),
10158 PDiag(diag::err_deduced_class_template_ctor_ambiguous)
10159 << TemplateName),
10160 *this, OCD_AmbiguousCandidates, Inits);
10161 return QualType();
10162
10163 case OR_No_Viable_Function: {
10164 CXXRecordDecl *Primary =
10165 cast<ClassTemplateDecl>(Template)->getTemplatedDecl();
10166 bool Complete =
10167 isCompleteType(Kind.getLocation(), Context.getTypeDeclType(Primary));
10168 Candidates.NoteCandidates(
10169 PartialDiagnosticAt(
10170 Kind.getLocation(),
10171 PDiag(Complete ? diag::err_deduced_class_template_ctor_no_viable
10172 : diag::err_deduced_class_template_incomplete)
10173 << TemplateName << !Guides.empty()),
10174 *this, OCD_AllCandidates, Inits);
10175 return QualType();
10176 }
10177
10178 case OR_Deleted: {
10179 Diag(Kind.getLocation(), diag::err_deduced_class_template_deleted)
10180 << TemplateName;
10181 NoteDeletedFunction(Best->Function);
10182 return QualType();
10183 }
10184
10185 case OR_Success:
10186 // C++ [over.match.list]p1:
10187 // In copy-list-initialization, if an explicit constructor is chosen, the
10188 // initialization is ill-formed.
10189 if (Kind.isCopyInit() && ListInit &&
10190 cast<CXXDeductionGuideDecl>(Best->Function)->isExplicit()) {
10191 bool IsDeductionGuide = !Best->Function->isImplicit();
10192 Diag(Kind.getLocation(), diag::err_deduced_class_template_explicit)
10193 << TemplateName << IsDeductionGuide;
10194 Diag(Best->Function->getLocation(),
10195 diag::note_explicit_ctor_deduction_guide_here)
10196 << IsDeductionGuide;
10197 return QualType();
10198 }
10199
10200 // Make sure we didn't select an unusable deduction guide, and mark it
10201 // as referenced.
10202 DiagnoseUseOfDecl(Best->Function, Kind.getLocation());
10203 MarkFunctionReferenced(Kind.getLocation(), Best->Function);
10204 break;
10205 }
10206
10207 // C++ [dcl.type.class.deduct]p1:
10208 // The placeholder is replaced by the return type of the function selected
10209 // by overload resolution for class template deduction.
10210 QualType DeducedType =
10211 SubstAutoType(TSInfo->getType(), Best->Function->getReturnType());
10212 Diag(TSInfo->getTypeLoc().getBeginLoc(),
10213 diag::warn_cxx14_compat_class_template_argument_deduction)
10214 << TSInfo->getTypeLoc().getSourceRange() << 1 << DeducedType;
10215
10216 // Warn if CTAD was used on a type that does not have any user-defined
10217 // deduction guides.
10218 if (!HasAnyDeductionGuide) {
10219 Diag(TSInfo->getTypeLoc().getBeginLoc(),
10220 diag::warn_ctad_maybe_unsupported)
10221 << TemplateName;
10222 Diag(Template->getLocation(), diag::note_suppress_ctad_maybe_unsupported);
10223 }
10224
10225 return DeducedType;
10226}
←

/usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/include/clang/Sema/Overload.h

1//===- Overload.h - C++ Overloading -----------------------------*- C++ -*-===//
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 defines the data structures and types used in C++
10// overload resolution.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_SEMA_OVERLOAD_H
15#define LLVM_CLANG_SEMA_OVERLOAD_H
16
17#include "clang/AST/Decl.h"
18#include "clang/AST/DeclAccessPair.h"
19#include "clang/AST/DeclBase.h"
20#include "clang/AST/DeclCXX.h"
21#include "clang/AST/DeclTemplate.h"
22#include "clang/AST/Expr.h"
23#include "clang/AST/Type.h"
24#include "clang/Basic/LLVM.h"
25#include "clang/Basic/SourceLocation.h"
26#include "clang/Sema/SemaFixItUtils.h"
27#include "clang/Sema/TemplateDeduction.h"
28#include "llvm/ADT/ArrayRef.h"
29#include "llvm/ADT/None.h"
30#include "llvm/ADT/STLExtras.h"
31#include "llvm/ADT/SmallPtrSet.h"
32#include "llvm/ADT/SmallVector.h"
33#include "llvm/ADT/StringRef.h"
34#include "llvm/Support/AlignOf.h"
35#include "llvm/Support/Allocator.h"
36#include "llvm/Support/Casting.h"
37#include "llvm/Support/ErrorHandling.h"
38#include <cassert>
39#include <cstddef>
40#include <cstdint>
41#include <utility>
42
43namespace clang {
44
45class APValue;
46class ASTContext;
47class Sema;
48
49 /// OverloadingResult - Capture the result of performing overload
50 /// resolution.
51 enum OverloadingResult {
52 /// Overload resolution succeeded.
53 OR_Success,
54
55 /// No viable function found.
56 OR_No_Viable_Function,
57
58 /// Ambiguous candidates found.
59 OR_Ambiguous,
60
61 /// Succeeded, but refers to a deleted function.
62 OR_Deleted
63 };
64
65 enum OverloadCandidateDisplayKind {
66 /// Requests that all candidates be shown. Viable candidates will
67 /// be printed first.
68 OCD_AllCandidates,
69
70 /// Requests that only viable candidates be shown.
71 OCD_ViableCandidates,
72
73 /// Requests that only tied-for-best candidates be shown.
74 OCD_AmbiguousCandidates
75 };
76
77 /// The parameter ordering that will be used for the candidate. This is
78 /// used to represent C++20 binary operator rewrites that reverse the order
79 /// of the arguments. If the parameter ordering is Reversed, the Args list is
80 /// reversed (but obviously the ParamDecls for the function are not).
81 ///
82 /// After forming an OverloadCandidate with reversed parameters, the list
83 /// of conversions will (as always) be indexed by argument, so will be
84 /// in reverse parameter order.
85 enum class OverloadCandidateParamOrder : char { Normal, Reversed };
86
87 /// The kinds of rewrite we perform on overload candidates. Note that the
88 /// values here are chosen to serve as both bitflags and as a rank (lower
89 /// values are preferred by overload resolution).
90 enum OverloadCandidateRewriteKind : unsigned {
91 /// Candidate is not a rewritten candidate.
92 CRK_None = 0x0,
93
94 /// Candidate is a rewritten candidate with a different operator name.
95 CRK_DifferentOperator = 0x1,
96
97 /// Candidate is a rewritten candidate with a reversed order of parameters.
98 CRK_Reversed = 0x2,
99 };
100
101 /// ImplicitConversionKind - The kind of implicit conversion used to
102 /// convert an argument to a parameter's type. The enumerator values
103 /// match with the table titled 'Conversions' in [over.ics.scs] and are listed
104 /// such that better conversion kinds have smaller values.
105 enum ImplicitConversionKind {
106 /// Identity conversion (no conversion)
107 ICK_Identity = 0,
108
109 /// Lvalue-to-rvalue conversion (C++ [conv.lval])
110 ICK_Lvalue_To_Rvalue,
111
112 /// Array-to-pointer conversion (C++ [conv.array])
113 ICK_Array_To_Pointer,
114
115 /// Function-to-pointer (C++ [conv.array])
116 ICK_Function_To_Pointer,
117
118 /// Function pointer conversion (C++17 [conv.fctptr])
119 ICK_Function_Conversion,
120
121 /// Qualification conversions (C++ [conv.qual])
122 ICK_Qualification,
123
124 /// Integral promotions (C++ [conv.prom])
125 ICK_Integral_Promotion,
126
127 /// Floating point promotions (C++ [conv.fpprom])
128 ICK_Floating_Promotion,
129
130 /// Complex promotions (Clang extension)
131 ICK_Complex_Promotion,
132
133 /// Integral conversions (C++ [conv.integral])
134 ICK_Integral_Conversion,
135
136 /// Floating point conversions (C++ [conv.double]
137 ICK_Floating_Conversion,
138
139 /// Complex conversions (C99 6.3.1.6)
140 ICK_Complex_Conversion,
141
142 /// Floating-integral conversions (C++ [conv.fpint])
143 ICK_Floating_Integral,
144
145 /// Pointer conversions (C++ [conv.ptr])
146 ICK_Pointer_Conversion,
147
148 /// Pointer-to-member conversions (C++ [conv.mem])
149 ICK_Pointer_Member,
150
151 /// Boolean conversions (C++ [conv.bool])
152 ICK_Boolean_Conversion,
153
154 /// Conversions between compatible types in C99
155 ICK_Compatible_Conversion,
156
157 /// Derived-to-base (C++ [over.best.ics])
158 ICK_Derived_To_Base,
159
160 /// Vector conversions
161 ICK_Vector_Conversion,
162
163 /// Arm SVE Vector conversions
164 ICK_SVE_Vector_Conversion,
165
166 /// A vector splat from an arithmetic type
167 ICK_Vector_Splat,
168
169 /// Complex-real conversions (C99 6.3.1.7)
170 ICK_Complex_Real,
171
172 /// Block Pointer conversions
173 ICK_Block_Pointer_Conversion,
174
175 /// Transparent Union Conversions
176 ICK_TransparentUnionConversion,
177
178 /// Objective-C ARC writeback conversion
179 ICK_Writeback_Conversion,
180
181 /// Zero constant to event (OpenCL1.2 6.12.10)
182 ICK_Zero_Event_Conversion,
183
184 /// Zero constant to queue
185 ICK_Zero_Queue_Conversion,
186
187 /// Conversions allowed in C, but not C++
188 ICK_C_Only_Conversion,
189
190 /// C-only conversion between pointers with incompatible types
191 ICK_Incompatible_Pointer_Conversion,
192
193 /// The number of conversion kinds
194 ICK_Num_Conversion_Kinds,
195 };
196
197 /// ImplicitConversionRank - The rank of an implicit conversion
198 /// kind. The enumerator values match with Table 9 of (C++
199 /// 13.3.3.1.1) and are listed such that better conversion ranks
200 /// have smaller values.
201 enum ImplicitConversionRank {
202 /// Exact Match
203 ICR_Exact_Match = 0,
204
205 /// Promotion
206 ICR_Promotion,
207
208 /// Conversion
209 ICR_Conversion,
210
211 /// OpenCL Scalar Widening
212 ICR_OCL_Scalar_Widening,
213
214 /// Complex <-> Real conversion
215 ICR_Complex_Real_Conversion,
216
217 /// ObjC ARC writeback conversion
218 ICR_Writeback_Conversion,
219
220 /// Conversion only allowed in the C standard (e.g. void* to char*).
221 ICR_C_Conversion,
222
223 /// Conversion not allowed by the C standard, but that we accept as an
224 /// extension anyway.
225 ICR_C_Conversion_Extension
226 };
227
228 ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind);
229
230 /// NarrowingKind - The kind of narrowing conversion being performed by a
231 /// standard conversion sequence according to C++11 [dcl.init.list]p7.
232 enum NarrowingKind {
233 /// Not a narrowing conversion.
234 NK_Not_Narrowing,
235
236 /// A narrowing conversion by virtue of the source and destination types.
237 NK_Type_Narrowing,
238
239 /// A narrowing conversion, because a constant expression got narrowed.
240 NK_Constant_Narrowing,
241
242 /// A narrowing conversion, because a non-constant-expression variable might
243 /// have got narrowed.
244 NK_Variable_Narrowing,
245
246 /// Cannot tell whether this is a narrowing conversion because the
247 /// expression is value-dependent.
248 NK_Dependent_Narrowing,
249 };
250
251 /// StandardConversionSequence - represents a standard conversion
252 /// sequence (C++ 13.3.3.1.1). A standard conversion sequence
253 /// contains between zero and three conversions. If a particular
254 /// conversion is not needed, it will be set to the identity conversion
255 /// (ICK_Identity). Note that the three conversions are
256 /// specified as separate members (rather than in an array) so that
257 /// we can keep the size of a standard conversion sequence to a
258 /// single word.
259 class StandardConversionSequence {
260 public:
261 /// First -- The first conversion can be an lvalue-to-rvalue
262 /// conversion, array-to-pointer conversion, or
263 /// function-to-pointer conversion.
264 ImplicitConversionKind First : 8;
265
266 /// Second - The second conversion can be an integral promotion,
267 /// floating point promotion, integral conversion, floating point
268 /// conversion, floating-integral conversion, pointer conversion,
269 /// pointer-to-member conversion, or boolean conversion.
270 ImplicitConversionKind Second : 8;
271
272 /// Third - The third conversion can be a qualification conversion
273 /// or a function conversion.
274 ImplicitConversionKind Third : 8;
275
276 /// Whether this is the deprecated conversion of a
277 /// string literal to a pointer to non-const character data
278 /// (C++ 4.2p2).
279 unsigned DeprecatedStringLiteralToCharPtr : 1;
280
281 /// Whether the qualification conversion involves a change in the
282 /// Objective-C lifetime (for automatic reference counting).
283 unsigned QualificationIncludesObjCLifetime : 1;
284
285 /// IncompatibleObjC - Whether this is an Objective-C conversion
286 /// that we should warn about (if we actually use it).
287 unsigned IncompatibleObjC : 1;
288
289 /// ReferenceBinding - True when this is a reference binding
290 /// (C++ [over.ics.ref]).
291 unsigned ReferenceBinding : 1;
292
293 /// DirectBinding - True when this is a reference binding that is a
294 /// direct binding (C++ [dcl.init.ref]).
295 unsigned DirectBinding : 1;
296
297 /// Whether this is an lvalue reference binding (otherwise, it's
298 /// an rvalue reference binding).
299 unsigned IsLvalueReference : 1;
300
301 /// Whether we're binding to a function lvalue.
302 unsigned BindsToFunctionLvalue : 1;
303
304 /// Whether we're binding to an rvalue.
305 unsigned BindsToRvalue : 1;
306
307 /// Whether this binds an implicit object argument to a
308 /// non-static member function without a ref-qualifier.
309 unsigned BindsImplicitObjectArgumentWithoutRefQualifier : 1;
310
311 /// Whether this binds a reference to an object with a different
312 /// Objective-C lifetime qualifier.
313 unsigned ObjCLifetimeConversionBinding : 1;
314
315 /// FromType - The type that this conversion is converting
316 /// from. This is an opaque pointer that can be translated into a
317 /// QualType.
318 void *FromTypePtr;
319
320 /// ToType - The types that this conversion is converting to in
321 /// each step. This is an opaque pointer that can be translated
322 /// into a QualType.
323 void *ToTypePtrs[3];
324
325 /// CopyConstructor - The copy constructor that is used to perform
326 /// this conversion, when the conversion is actually just the
327 /// initialization of an object via copy constructor. Such
328 /// conversions are either identity conversions or derived-to-base
329 /// conversions.
330 CXXConstructorDecl *CopyConstructor;
331 DeclAccessPair FoundCopyConstructor;
332
333 void setFromType(QualType T) { FromTypePtr = T.getAsOpaquePtr(); }
334
335 void setToType(unsigned Idx, QualType T) {
336 assert(Idx < 3 && "To type index is out of range")((void)0);
337 ToTypePtrs[Idx] = T.getAsOpaquePtr();
338 }
339
340 void setAllToTypes(QualType T) {
341 ToTypePtrs[0] = T.getAsOpaquePtr();
342 ToTypePtrs[1] = ToTypePtrs[0];
343 ToTypePtrs[2] = ToTypePtrs[0];
344 }
345
346 QualType getFromType() const {
347 return QualType::getFromOpaquePtr(FromTypePtr);
348 }
349
350 QualType getToType(unsigned Idx) const {
351 assert(Idx < 3 && "To type index is out of range")((void)0);
352 return QualType::getFromOpaquePtr(ToTypePtrs[Idx]);
353 }
354
355 void setAsIdentityConversion();
356
357 bool isIdentityConversion() const {
358 return Second == ICK_Identity && Third == ICK_Identity;
359 }
360
361 ImplicitConversionRank getRank() const;
362 NarrowingKind
363 getNarrowingKind(ASTContext &Context, const Expr *Converted,
364 APValue &ConstantValue, QualType &ConstantType,
365 bool IgnoreFloatToIntegralConversion = false) const;
366 bool isPointerConversionToBool() const;
367 bool isPointerConversionToVoidPointer(ASTContext& Context) const;
368 void dump() const;
369 };
370
371 /// UserDefinedConversionSequence - Represents a user-defined
372 /// conversion sequence (C++ 13.3.3.1.2).
373 struct UserDefinedConversionSequence {
374 /// Represents the standard conversion that occurs before
375 /// the actual user-defined conversion.
376 ///
377 /// C++11 13.3.3.1.2p1:
378 /// If the user-defined conversion is specified by a constructor
379 /// (12.3.1), the initial standard conversion sequence converts
380 /// the source type to the type required by the argument of the
381 /// constructor. If the user-defined conversion is specified by
382 /// a conversion function (12.3.2), the initial standard
383 /// conversion sequence converts the source type to the implicit
384 /// object parameter of the conversion function.
385 StandardConversionSequence Before;
386
387 /// EllipsisConversion - When this is true, it means user-defined
388 /// conversion sequence starts with a ... (ellipsis) conversion, instead of
389 /// a standard conversion. In this case, 'Before' field must be ignored.
390 // FIXME. I much rather put this as the first field. But there seems to be
391 // a gcc code gen. bug which causes a crash in a test. Putting it here seems
392 // to work around the crash.
393 bool EllipsisConversion : 1;
394
395 /// HadMultipleCandidates - When this is true, it means that the
396 /// conversion function was resolved from an overloaded set having
397 /// size greater than 1.
398 bool HadMultipleCandidates : 1;
399
400 /// After - Represents the standard conversion that occurs after
401 /// the actual user-defined conversion.
402 StandardConversionSequence After;
403
404 /// ConversionFunction - The function that will perform the
405 /// user-defined conversion. Null if the conversion is an
406 /// aggregate initialization from an initializer list.
407 FunctionDecl* ConversionFunction;
408
409 /// The declaration that we found via name lookup, which might be
410 /// the same as \c ConversionFunction or it might be a using declaration
411 /// that refers to \c ConversionFunction.
412 DeclAccessPair FoundConversionFunction;
413
414 void dump() const;
415 };
416
417 /// Represents an ambiguous user-defined conversion sequence.
418 struct AmbiguousConversionSequence {
419 using ConversionSet =
420 SmallVector<std::pair<NamedDecl *, FunctionDecl *>, 4>;
421
422 void *FromTypePtr;
423 void *ToTypePtr;
424 char Buffer[sizeof(ConversionSet)];
425
426 QualType getFromType() const {
427 return QualType::getFromOpaquePtr(FromTypePtr);
428 }
429
430 QualType getToType() const {
431 return QualType::getFromOpaquePtr(ToTypePtr);
432 }
433
434 void setFromType(QualType T) { FromTypePtr = T.getAsOpaquePtr(); }
435 void setToType(QualType T) { ToTypePtr = T.getAsOpaquePtr(); }
436
437 ConversionSet &conversions() {
438 return *reinterpret_cast<ConversionSet*>(Buffer);
439 }
440
441 const ConversionSet &conversions() const {
442 return *reinterpret_cast<const ConversionSet*>(Buffer);
443 }
444
445 void addConversion(NamedDecl *Found, FunctionDecl *D) {
446 conversions().push_back(std::make_pair(Found, D));
447 }
448
449 using iterator = ConversionSet::iterator;
450
451 iterator begin() { return conversions().begin(); }
452 iterator end() { return conversions().end(); }
453
454 using const_iterator = ConversionSet::const_iterator;
455
456 const_iterator begin() const { return conversions().begin(); }
457 const_iterator end() const { return conversions().end(); }
458
459 void construct();
460 void destruct();
461 void copyFrom(const AmbiguousConversionSequence &);
462 };
463
464 /// BadConversionSequence - Records information about an invalid
465 /// conversion sequence.
466 struct BadConversionSequence {
467 enum FailureKind {
468 no_conversion,
469 unrelated_class,
470 bad_qualifiers,
471 lvalue_ref_to_rvalue,
472 rvalue_ref_to_lvalue
473 };
474
475 // This can be null, e.g. for implicit object arguments.
476 Expr *FromExpr;
477
478 FailureKind Kind;
479
480 private:
481 // The type we're converting from (an opaque QualType).
482 void *FromTy;
483
484 // The type we're converting to (an opaque QualType).
485 void *ToTy;
486
487 public:
488 void init(FailureKind K, Expr *From, QualType To) {
489 init(K, From->getType(), To);
490 FromExpr = From;
491 }
492
493 void init(FailureKind K, QualType From, QualType To) {
494 Kind = K;
495 FromExpr = nullptr;
496 setFromType(From);
497 setToType(To);
498 }
499
500 QualType getFromType() const { return QualType::getFromOpaquePtr(FromTy); }
501 QualType getToType() const { return QualType::getFromOpaquePtr(ToTy); }
502
503 void setFromExpr(Expr *E) {
504 FromExpr = E;
505 setFromType(E->getType());
506 }
507
508 void setFromType(QualType T) { FromTy = T.getAsOpaquePtr(); }
509 void setToType(QualType T) { ToTy = T.getAsOpaquePtr(); }
510 };
511
512 /// ImplicitConversionSequence - Represents an implicit conversion
513 /// sequence, which may be a standard conversion sequence
514 /// (C++ 13.3.3.1.1), user-defined conversion sequence (C++ 13.3.3.1.2),
515 /// or an ellipsis conversion sequence (C++ 13.3.3.1.3).
516 class ImplicitConversionSequence {
517 public:
518 /// Kind - The kind of implicit conversion sequence. BadConversion
519 /// specifies that there is no conversion from the source type to
520 /// the target type. AmbiguousConversion represents the unique
521 /// ambiguous conversion (C++0x [over.best.ics]p10).
522 enum Kind {
523 StandardConversion = 0,
524 UserDefinedConversion,
525 AmbiguousConversion,
526 EllipsisConversion,
527 BadConversion
528 };
529
530 private:
531 enum {
532 Uninitialized = BadConversion + 1
533 };
534
535 /// ConversionKind - The kind of implicit conversion sequence.
536 unsigned ConversionKind : 30;
537
538 /// Whether the target is really a std::initializer_list, and the
539 /// sequence only represents the worst element conversion.
540 unsigned StdInitializerListElement : 1;
541
542 void setKind(Kind K) {
543 destruct();
544 ConversionKind = K;
545 }
546
547 void destruct() {
548 if (ConversionKind == AmbiguousConversion) Ambiguous.destruct();
549 }
550
551 public:
552 union {
553 /// When ConversionKind == StandardConversion, provides the
554 /// details of the standard conversion sequence.
555 StandardConversionSequence Standard;
556
557 /// When ConversionKind == UserDefinedConversion, provides the
558 /// details of the user-defined conversion sequence.
559 UserDefinedConversionSequence UserDefined;
560
561 /// When ConversionKind == AmbiguousConversion, provides the
562 /// details of the ambiguous conversion.
563 AmbiguousConversionSequence Ambiguous;
564
565 /// When ConversionKind == BadConversion, provides the details
566 /// of the bad conversion.
567 BadConversionSequence Bad;
568 };
569
570 ImplicitConversionSequence()
571 : ConversionKind(Uninitialized), StdInitializerListElement(false) {
572 Standard.setAsIdentityConversion();
573 }
574
575 ImplicitConversionSequence(const ImplicitConversionSequence &Other)
576 : ConversionKind(Other.ConversionKind),
577 StdInitializerListElement(Other.StdInitializerListElement) {
578 switch (ConversionKind) {
579 case Uninitialized: break;
580 case StandardConversion: Standard = Other.Standard; break;
581 case UserDefinedConversion: UserDefined = Other.UserDefined; break;
582 case AmbiguousConversion: Ambiguous.copyFrom(Other.Ambiguous); break;
583 case EllipsisConversion: break;
584 case BadConversion: Bad = Other.Bad; break;
585 }
586 }
587
588 ImplicitConversionSequence &
589 operator=(const ImplicitConversionSequence &Other) {
590 destruct();
591 new (this) ImplicitConversionSequence(Other);
592 return *this;
593 }
594
595 ~ImplicitConversionSequence() {
596 destruct();
597 }
598
599 Kind getKind() const {
600 assert(isInitialized() && "querying uninitialized conversion")((void)0);
601 return Kind(ConversionKind);
602 }
603
604 /// Return a ranking of the implicit conversion sequence
605 /// kind, where smaller ranks represent better conversion
606 /// sequences.
607 ///
608 /// In particular, this routine gives user-defined conversion
609 /// sequences and ambiguous conversion sequences the same rank,
610 /// per C++ [over.best.ics]p10.
611 unsigned getKindRank() const {
612 switch (getKind()) {
613 case StandardConversion:
614 return 0;
615
616 case UserDefinedConversion:
617 case AmbiguousConversion:
618 return 1;
619
620 case EllipsisConversion:
621 return 2;
622
623 case BadConversion:
624 return 3;
625 }
626
627 llvm_unreachable("Invalid ImplicitConversionSequence::Kind!")__builtin_unreachable();
628 }
629
630 bool isBad() const { return getKind() == BadConversion; }
631 bool isStandard() const { return getKind() == StandardConversion; }
632 bool isEllipsis() const { return getKind() == EllipsisConversion; }
633 bool isAmbiguous() const { return getKind() == AmbiguousConversion; }
634 bool isUserDefined() const { return getKind() == UserDefinedConversion; }
635 bool isFailure() const { return isBad() || isAmbiguous(); }
636
637 /// Determines whether this conversion sequence has been
638 /// initialized. Most operations should never need to query
639 /// uninitialized conversions and should assert as above.
640 bool isInitialized() const { return ConversionKind != Uninitialized; }
641
642 /// Sets this sequence as a bad conversion for an explicit argument.
643 void setBad(BadConversionSequence::FailureKind Failure,
644 Expr *FromExpr, QualType ToType) {
645 setKind(BadConversion);
646 Bad.init(Failure, FromExpr, ToType);
647 }
648
649 /// Sets this sequence as a bad conversion for an implicit argument.
650 void setBad(BadConversionSequence::FailureKind Failure,
651 QualType FromType, QualType ToType) {
652 setKind(BadConversion);
653 Bad.init(Failure, FromType, ToType);
654 }
655
656 void setStandard() { setKind(StandardConversion); }
657 void setEllipsis() { setKind(EllipsisConversion); }
658 void setUserDefined() { setKind(UserDefinedConversion); }
659
660 void setAmbiguous() {
661 if (ConversionKind == AmbiguousConversion) return;
662 ConversionKind = AmbiguousConversion;
663 Ambiguous.construct();
664 }
665
666 void setAsIdentityConversion(QualType T) {
667 setStandard();
668 Standard.setAsIdentityConversion();
669 Standard.setFromType(T);
670 Standard.setAllToTypes(T);
671 }
672
673 /// Whether the target is really a std::initializer_list, and the
674 /// sequence only represents the worst element conversion.
675 bool isStdInitializerListElement() const {
676 return StdInitializerListElement;
677 }
678
679 void setStdInitializerListElement(bool V = true) {
680 StdInitializerListElement = V;
681 }
682
683 /// Form an "implicit" conversion sequence from nullptr_t to bool, for a
684 /// direct-initialization of a bool object from nullptr_t.
685 static ImplicitConversionSequence getNullptrToBool(QualType SourceType,
686 QualType DestType,
687 bool NeedLValToRVal) {
688 ImplicitConversionSequence ICS;
689 ICS.setStandard();
690 ICS.Standard.setAsIdentityConversion();
691 ICS.Standard.setFromType(SourceType);
692 if (NeedLValToRVal)
693 ICS.Standard.First = ICK_Lvalue_To_Rvalue;
694 ICS.Standard.setToType(0, SourceType);
695 ICS.Standard.Second = ICK_Boolean_Conversion;
696 ICS.Standard.setToType(1, DestType);
697 ICS.Standard.setToType(2, DestType);
698 return ICS;
699 }
700
701 // The result of a comparison between implicit conversion
702 // sequences. Use Sema::CompareImplicitConversionSequences to
703 // actually perform the comparison.
704 enum CompareKind {
705 Better = -1,
706 Indistinguishable = 0,
707 Worse = 1
708 };
709
710 void DiagnoseAmbiguousConversion(Sema &S,
711 SourceLocation CaretLoc,
712 const PartialDiagnostic &PDiag) const;
713
714 void dump() const;
715 };
716
717 enum OverloadFailureKind {
718 ovl_fail_too_many_arguments,
719 ovl_fail_too_few_arguments,
720 ovl_fail_bad_conversion,
721 ovl_fail_bad_deduction,
722
723 /// This conversion candidate was not considered because it
724 /// duplicates the work of a trivial or derived-to-base
725 /// conversion.
726 ovl_fail_trivial_conversion,
727
728 /// This conversion candidate was not considered because it is
729 /// an illegal instantiation of a constructor temploid: it is
730 /// callable with one argument, we only have one argument, and
731 /// its first parameter type is exactly the type of the class.
732 ///
733 /// Defining such a constructor directly is illegal, and
734 /// template-argument deduction is supposed to ignore such
735 /// instantiations, but we can still get one with the right
736 /// kind of implicit instantiation.
737 ovl_fail_illegal_constructor,
738
739 /// This conversion candidate is not viable because its result
740 /// type is not implicitly convertible to the desired type.
741 ovl_fail_bad_final_conversion,
742
743 /// This conversion function template specialization candidate is not
744 /// viable because the final conversion was not an exact match.
745 ovl_fail_final_conversion_not_exact,
746
747 /// (CUDA) This candidate was not viable because the callee
748 /// was not accessible from the caller's target (i.e. host->device,
749 /// global->host, device->host).
750 ovl_fail_bad_target,
751
752 /// This candidate function was not viable because an enable_if
753 /// attribute disabled it.
754 ovl_fail_enable_if,
755
756 /// This candidate constructor or conversion function is explicit but
757 /// the context doesn't permit explicit functions.
758 ovl_fail_explicit,
759
760 /// This candidate was not viable because its address could not be taken.
761 ovl_fail_addr_not_available,
762
763 /// This inherited constructor is not viable because it would slice the
764 /// argument.
765 ovl_fail_inhctor_slice,
766
767 /// This candidate was not viable because it is a non-default multiversioned
768 /// function.
769 ovl_non_default_multiversion_function,
770
771 /// This constructor/conversion candidate fail due to an address space
772 /// mismatch between the object being constructed and the overload
773 /// candidate.
774 ovl_fail_object_addrspace_mismatch,
775
776 /// This candidate was not viable because its associated constraints were
777 /// not satisfied.
778 ovl_fail_constraints_not_satisfied,
779 };
780
781 /// A list of implicit conversion sequences for the arguments of an
782 /// OverloadCandidate.
783 using ConversionSequenceList =
784 llvm::MutableArrayRef<ImplicitConversionSequence>;
785
786 /// OverloadCandidate - A single candidate in an overload set (C++ 13.3).
787 struct OverloadCandidate {
788 /// Function - The actual function that this candidate
789 /// represents. When NULL, this is a built-in candidate
790 /// (C++ [over.oper]) or a surrogate for a conversion to a
791 /// function pointer or reference (C++ [over.call.object]).
792 FunctionDecl *Function;
793
794 /// FoundDecl - The original declaration that was looked up /
795 /// invented / otherwise found, together with its access.
796 /// Might be a UsingShadowDecl or a FunctionTemplateDecl.
797 DeclAccessPair FoundDecl;
798
799 /// BuiltinParamTypes - Provides the parameter types of a built-in overload
800 /// candidate. Only valid when Function is NULL.
801 QualType BuiltinParamTypes[3];
802
803 /// Surrogate - The conversion function for which this candidate
804 /// is a surrogate, but only if IsSurrogate is true.
805 CXXConversionDecl *Surrogate;
806
807 /// The conversion sequences used to convert the function arguments
808 /// to the function parameters. Note that these are indexed by argument,
809 /// so may not match the parameter order of Function.
810 ConversionSequenceList Conversions;
811
812 /// The FixIt hints which can be used to fix the Bad candidate.
813 ConversionFixItGenerator Fix;
814
815 /// Viable - True to indicate that this overload candidate is viable.
816 bool Viable : 1;
817
818 /// Whether this candidate is the best viable function, or tied for being
819 /// the best viable function.
820 ///
821 /// For an ambiguous overload resolution, indicates whether this candidate
822 /// was part of the ambiguity kernel: the minimal non-empty set of viable
823 /// candidates such that all elements of the ambiguity kernel are better
824 /// than all viable candidates not in the ambiguity kernel.
825 bool Best : 1;
826
827 /// IsSurrogate - True to indicate that this candidate is a
828 /// surrogate for a conversion to a function pointer or reference
829 /// (C++ [over.call.object]).
830 bool IsSurrogate : 1;
831
832 /// IgnoreObjectArgument - True to indicate that the first
833 /// argument's conversion, which for this function represents the
834 /// implicit object argument, should be ignored. This will be true
835 /// when the candidate is a static member function (where the
836 /// implicit object argument is just a placeholder) or a
837 /// non-static member function when the call doesn't have an
838 /// object argument.
839 bool IgnoreObjectArgument : 1;
840
841 /// True if the candidate was found using ADL.
842 CallExpr::ADLCallKind IsADLCandidate : 1;
843
844 /// Whether this is a rewritten candidate, and if so, of what kind?
845 unsigned RewriteKind : 2;
846
847 /// FailureKind - The reason why this candidate is not viable.
848 /// Actually an OverloadFailureKind.
849 unsigned char FailureKind;
850
851 /// The number of call arguments that were explicitly provided,
852 /// to be used while performing partial ordering of function templates.
853 unsigned ExplicitCallArguments;
854
855 union {
856 DeductionFailureInfo DeductionFailure;
857
858 /// FinalConversion - For a conversion function (where Function is
859 /// a CXXConversionDecl), the standard conversion that occurs
860 /// after the call to the overload candidate to convert the result
861 /// of calling the conversion function to the required type.
862 StandardConversionSequence FinalConversion;
863 };
864
865 /// Get RewriteKind value in OverloadCandidateRewriteKind type (This
866 /// function is to workaround the spurious GCC bitfield enum warning)
867 OverloadCandidateRewriteKind getRewriteKind() const {
868 return static_cast<OverloadCandidateRewriteKind>(RewriteKind);
869 }
870
871 bool isReversed() const { return getRewriteKind() & CRK_Reversed; }
872
873 /// hasAmbiguousConversion - Returns whether this overload
874 /// candidate requires an ambiguous conversion or not.
875 bool hasAmbiguousConversion() const {
876 for (auto &C : Conversions) {
877 if (!C.isInitialized()) return false;
878 if (C.isAmbiguous()) return true;
879 }
880 return false;
881 }
882
883 bool TryToFixBadConversion(unsigned Idx, Sema &S) {
884 bool CanFix = Fix.tryToFixConversion(
885 Conversions[Idx].Bad.FromExpr,
886 Conversions[Idx].Bad.getFromType(),
887 Conversions[Idx].Bad.getToType(), S);
888
889 // If at least one conversion fails, the candidate cannot be fixed.
890 if (!CanFix)
891 Fix.clear();
892
893 return CanFix;
894 }
895
896 unsigned getNumParams() const {
897 if (IsSurrogate) {
898 QualType STy = Surrogate->getConversionType();
899 while (STy->isPointerType() || STy->isReferenceType())
900 STy = STy->getPointeeType();
901 return STy->castAs<FunctionProtoType>()->getNumParams();
902 }
903 if (Function)
904 return Function->getNumParams();
905 return ExplicitCallArguments;
906 }
907
908 private:
909 friend class OverloadCandidateSet;
910 OverloadCandidate()
911 : IsSurrogate(false), IsADLCandidate(CallExpr::NotADL), RewriteKind(CRK_None) {}
912 };
913
914 /// OverloadCandidateSet - A set of overload candidates, used in C++
915 /// overload resolution (C++ 13.3).
916 class OverloadCandidateSet {
917 public:
918 enum CandidateSetKind {
919 /// Normal lookup.
920 CSK_Normal,
921
922 /// C++ [over.match.oper]:
923 /// Lookup of operator function candidates in a call using operator
924 /// syntax. Candidates that have no parameters of class type will be
925 /// skipped unless there is a parameter of (reference to) enum type and
926 /// the corresponding argument is of the same enum type.
927 CSK_Operator,
928
929 /// C++ [over.match.copy]:
930 /// Copy-initialization of an object of class type by user-defined
931 /// conversion.
932 CSK_InitByUserDefinedConversion,
933
934 /// C++ [over.match.ctor], [over.match.list]
935 /// Initialization of an object of class type by constructor,
936 /// using either a parenthesized or braced list of arguments.
937 CSK_InitByConstructor,
938 };
939
940 /// Information about operator rewrites to consider when adding operator
941 /// functions to a candidate set.
942 struct OperatorRewriteInfo {
943 OperatorRewriteInfo()
944 : OriginalOperator(OO_None), AllowRewrittenCandidates(false) {}
945 OperatorRewriteInfo(OverloadedOperatorKind Op, bool AllowRewritten)
946 : OriginalOperator(Op), AllowRewrittenCandidates(AllowRewritten) {}
947
948 /// The original operator as written in the source.
949 OverloadedOperatorKind OriginalOperator;
950 /// Whether we should include rewritten candidates in the overload set.
951 bool AllowRewrittenCandidates;
952
953 /// Would use of this function result in a rewrite using a different
954 /// operator?
955 bool isRewrittenOperator(const FunctionDecl *FD) {
956 return OriginalOperator &&
957 FD->getDeclName().getCXXOverloadedOperator() != OriginalOperator;
958 }
959
960 bool isAcceptableCandidate(const FunctionDecl *FD) {
961 if (!OriginalOperator)
962 return true;
963
964 // For an overloaded operator, we can have candidates with a different
965 // name in our unqualified lookup set. Make sure we only consider the
966 // ones we're supposed to.
967 OverloadedOperatorKind OO =
968 FD->getDeclName().getCXXOverloadedOperator();
969 return OO && (OO == OriginalOperator ||
970 (AllowRewrittenCandidates &&
971 OO == getRewrittenOverloadedOperator(OriginalOperator)));
972 }
973
974 /// Determine the kind of rewrite that should be performed for this
975 /// candidate.
976 OverloadCandidateRewriteKind
977 getRewriteKind(const FunctionDecl *FD, OverloadCandidateParamOrder PO) {
978 OverloadCandidateRewriteKind CRK = CRK_None;
979 if (isRewrittenOperator(FD))
980 CRK = OverloadCandidateRewriteKind(CRK | CRK_DifferentOperator);
981 if (PO == OverloadCandidateParamOrder::Reversed)
982 CRK = OverloadCandidateRewriteKind(CRK | CRK_Reversed);
983 return CRK;
984 }
985
986 /// Determines whether this operator could be implemented by a function
987 /// with reversed parameter order.
988 bool isReversible() {
989 return AllowRewrittenCandidates && OriginalOperator &&
990 (getRewrittenOverloadedOperator(OriginalOperator) != OO_None ||
991 shouldAddReversed(OriginalOperator));
992 }
993
994 /// Determine whether we should consider looking for and adding reversed
995 /// candidates for operator Op.
996 bool shouldAddReversed(OverloadedOperatorKind Op);
997
998 /// Determine whether we should add a rewritten candidate for \p FD with
999 /// reversed parameter order.
1000 bool shouldAddReversed(ASTContext &Ctx, const FunctionDecl *FD);
1001 };
1002
1003 private:
1004 SmallVector<OverloadCandidate, 16> Candidates;
1005 llvm::SmallPtrSet<uintptr_t, 16> Functions;
1006
1007 // Allocator for ConversionSequenceLists. We store the first few of these
1008 // inline to avoid allocation for small sets.
1009 llvm::BumpPtrAllocator SlabAllocator;
1010
1011 SourceLocation Loc;
1012 CandidateSetKind Kind;
1013 OperatorRewriteInfo RewriteInfo;
1014
1015 constexpr static unsigned NumInlineBytes =
1016 24 * sizeof(ImplicitConversionSequence);
1017 unsigned NumInlineBytesUsed = 0;
1018 alignas(void *) char InlineSpace[NumInlineBytes];
1019
1020 // Address space of the object being constructed.
1021 LangAS DestAS = LangAS::Default;
1022
1023 /// If we have space, allocates from inline storage. Otherwise, allocates
1024 /// from the slab allocator.
1025 /// FIXME: It would probably be nice to have a SmallBumpPtrAllocator
1026 /// instead.
1027 /// FIXME: Now that this only allocates ImplicitConversionSequences, do we
1028 /// want to un-generalize this?
1029 template <typename T>
1030 T *slabAllocate(unsigned N) {
1031 // It's simpler if this doesn't need to consider alignment.
1032 static_assert(alignof(T) == alignof(void *),
1033 "Only works for pointer-aligned types.");
1034 static_assert(std::is_trivial<T>::value ||
1035 std::is_same<ImplicitConversionSequence, T>::value,
1036 "Add destruction logic to OverloadCandidateSet::clear().");
1037
1038 unsigned NBytes = sizeof(T) * N;
1039 if (NBytes > NumInlineBytes - NumInlineBytesUsed)
1040 return SlabAllocator.Allocate<T>(N);
1041 char *FreeSpaceStart = InlineSpace + NumInlineBytesUsed;
1042 assert(uintptr_t(FreeSpaceStart) % alignof(void *) == 0 &&((void)0)
1043 "Misaligned storage!")((void)0);
1044
1045 NumInlineBytesUsed += NBytes;
1046 return reinterpret_cast<T *>(FreeSpaceStart);
1047 }
1048
1049 void destroyCandidates();
1050
1051 public:
1052 OverloadCandidateSet(SourceLocation Loc, CandidateSetKind CSK,
1053 OperatorRewriteInfo RewriteInfo = {})
1054 : Loc(Loc), Kind(CSK), RewriteInfo(RewriteInfo) {}
1055 OverloadCandidateSet(const OverloadCandidateSet &) = delete;
1056 OverloadCandidateSet &operator=(const OverloadCandidateSet &) = delete;
1057 ~OverloadCandidateSet() { destroyCandidates(); }
1058
1059 SourceLocation getLocation() const { return Loc; }
1060 CandidateSetKind getKind() const { return Kind; }
1061 OperatorRewriteInfo getRewriteInfo() const { return RewriteInfo; }
1062
1063 /// Whether diagnostics should be deferred.
1064 bool shouldDeferDiags(Sema &S, ArrayRef<Expr *> Args, SourceLocation OpLoc);
1065
1066 /// Determine when this overload candidate will be new to the
1067 /// overload set.
1068 bool isNewCandidate(Decl *F, OverloadCandidateParamOrder PO =
1069 OverloadCandidateParamOrder::Normal) {
1070 uintptr_t Key = reinterpret_cast<uintptr_t>(F->getCanonicalDecl());
1071 Key |= static_cast<uintptr_t>(PO);
1072 return Functions.insert(Key).second;
1073 }
1074
1075 /// Exclude a function from being considered by overload resolution.
1076 void exclude(Decl *F) {
1077 isNewCandidate(F, OverloadCandidateParamOrder::Normal);
1078 isNewCandidate(F, OverloadCandidateParamOrder::Reversed);
1079 }
1080
1081 /// Clear out all of the candidates.
1082 void clear(CandidateSetKind CSK);
1083
1084 using iterator = SmallVectorImpl<OverloadCandidate>::iterator;
1085
1086 iterator begin() { return Candidates.begin(); }
1087 iterator end() { return Candidates.end(); }
1088
1089 size_t size() const { return Candidates.size(); }
1090 bool empty() const { return Candidates.empty(); }
1091
1092 /// Allocate storage for conversion sequences for NumConversions
1093 /// conversions.
1094 ConversionSequenceList
1095 allocateConversionSequences(unsigned NumConversions) {
1096 ImplicitConversionSequence *Conversions =
1097 slabAllocate<ImplicitConversionSequence>(NumConversions);
1098
1099 // Construct the new objects.
1100 for (unsigned I = 0; I != NumConversions; ++I)
1101 new (&Conversions[I]) ImplicitConversionSequence();
1102
1103 return ConversionSequenceList(Conversions, NumConversions);
1104 }
1105
1106 /// Add a new candidate with NumConversions conversion sequence slots
1107 /// to the overload set.
1108 OverloadCandidate &addCandidate(unsigned NumConversions = 0,
1109 ConversionSequenceList Conversions = None) {
1110 assert((Conversions.empty() || Conversions.size() == NumConversions) &&((void)0)
1111 "preallocated conversion sequence has wrong length")((void)0);
1112
1113 Candidates.push_back(OverloadCandidate());
1114 OverloadCandidate &C = Candidates.back();
1115 C.Conversions = Conversions.empty()
1116 ? allocateConversionSequences(NumConversions)
1117 : Conversions;
1118 return C;
1119 }
1120
1121 /// Find the best viable function on this overload set, if it exists.
1122 OverloadingResult BestViableFunction(Sema &S, SourceLocation Loc,
1123 OverloadCandidateSet::iterator& Best);
1124
1125 SmallVector<OverloadCandidate *, 32> CompleteCandidates(
1126 Sema &S, OverloadCandidateDisplayKind OCD, ArrayRef<Expr *> Args,
1127 SourceLocation OpLoc = SourceLocation(),
1128 llvm::function_ref<bool(OverloadCandidate &)> Filter =
1129 [](OverloadCandidate &) { return true; });
1130
1131 void NoteCandidates(
1132 PartialDiagnosticAt PA, Sema &S, OverloadCandidateDisplayKind OCD,
1133 ArrayRef<Expr *> Args, StringRef Opc = "",
1134 SourceLocation Loc = SourceLocation(),
1135 llvm::function_ref<bool(OverloadCandidate &)> Filter =
1136 [](OverloadCandidate &) { return true; });
1137
1138 void NoteCandidates(Sema &S, ArrayRef<Expr *> Args,
1139 ArrayRef<OverloadCandidate *> Cands,
1140 StringRef Opc = "",
1141 SourceLocation OpLoc = SourceLocation());
1142
1143 LangAS getDestAS() { return DestAS; }
1144
1145 void setDestAS(LangAS AS) {
1146 assert((Kind == CSK_InitByConstructor ||((void)0)
1147 Kind == CSK_InitByUserDefinedConversion) &&((void)0)
1148 "can't set the destination address space when not constructing an "((void)0)
1149 "object")((void)0);
1150 DestAS = AS;
1151 }
1152
1153 };
1154
1155 bool isBetterOverloadCandidate(Sema &S,
1156 const OverloadCandidate &Cand1,
1157 const OverloadCandidate &Cand2,
1158 SourceLocation Loc,
1159 OverloadCandidateSet::CandidateSetKind Kind);
1160
1161 struct ConstructorInfo {
1162 DeclAccessPair FoundDecl;
1163 CXXConstructorDecl *Constructor;
1164 FunctionTemplateDecl *ConstructorTmpl;
1165
1166 explicit operator bool() const { return Constructor; }
1167 };
1168
1169 // FIXME: Add an AddOverloadCandidate / AddTemplateOverloadCandidate overload
1170 // that takes one of these.
1171 inline ConstructorInfo getConstructorInfo(NamedDecl *ND) {
1172 if (isa<UsingDecl>(ND))
30
←
Assuming 'ND' is not a 'UsingDecl'
→
31
←
Taking false branch
→
1173 return ConstructorInfo{};
1174
1175 // For constructors, the access check is performed against the underlying
1176 // declaration, not the found declaration.
1177 auto *D = ND->getUnderlyingDecl();
1178 ConstructorInfo Info = {DeclAccessPair::make(ND, D->getAccess()), nullptr,
1179 nullptr};
1180 Info.ConstructorTmpl = dyn_cast<FunctionTemplateDecl>(D);
32
←
Assuming 'D' is not a 'FunctionTemplateDecl'
→
1181 if (Info.ConstructorTmpl
32.1
Field 'ConstructorTmpl' is null
32.1
Field 'ConstructorTmpl' is null
)
33
←
Taking false branch
→
1182 D = Info.ConstructorTmpl->getTemplatedDecl();
1183 Info.Constructor = dyn_cast<CXXConstructorDecl>(D);
34
←
Assuming 'D' is not a 'CXXConstructorDecl'
→
1184 return Info;
35
←
Null pointer value stored to field 'Constructor'
→
1185 }
1186
1187} // namespace clang
1188
1189#endif // LLVM_CLANG_SEMA_OVERLOAD_H