Bug Summary

File:src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaExprMember.cpp
Warning:line 375, column 12
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 SemaExprMember.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/SemaExprMember.cpp
1//===--- SemaExprMember.cpp - Semantic Analysis for Expressions -----------===//
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 member access expressions.
10//
11//===----------------------------------------------------------------------===//
12#include "clang/Sema/Overload.h"
13#include "clang/AST/ASTLambda.h"
14#include "clang/AST/DeclCXX.h"
15#include "clang/AST/DeclObjC.h"
16#include "clang/AST/DeclTemplate.h"
17#include "clang/AST/ExprCXX.h"
18#include "clang/AST/ExprObjC.h"
19#include "clang/Lex/Preprocessor.h"
20#include "clang/Sema/Lookup.h"
21#include "clang/Sema/Scope.h"
22#include "clang/Sema/ScopeInfo.h"
23#include "clang/Sema/SemaInternal.h"
24
25using namespace clang;
26using namespace sema;
27
28typedef llvm::SmallPtrSet<const CXXRecordDecl*, 4> BaseSet;
29
30/// Determines if the given class is provably not derived from all of
31/// the prospective base classes.
32static bool isProvablyNotDerivedFrom(Sema &SemaRef, CXXRecordDecl *Record,
33 const BaseSet &Bases) {
34 auto BaseIsNotInSet = [&Bases](const CXXRecordDecl *Base) {
35 return !Bases.count(Base->getCanonicalDecl());
36 };
37 return BaseIsNotInSet(Record) && Record->forallBases(BaseIsNotInSet);
38}
39
40enum IMAKind {
41 /// The reference is definitely not an instance member access.
42 IMA_Static,
43
44 /// The reference may be an implicit instance member access.
45 IMA_Mixed,
46
47 /// The reference may be to an instance member, but it might be invalid if
48 /// so, because the context is not an instance method.
49 IMA_Mixed_StaticContext,
50
51 /// The reference may be to an instance member, but it is invalid if
52 /// so, because the context is from an unrelated class.
53 IMA_Mixed_Unrelated,
54
55 /// The reference is definitely an implicit instance member access.
56 IMA_Instance,
57
58 /// The reference may be to an unresolved using declaration.
59 IMA_Unresolved,
60
61 /// The reference is a contextually-permitted abstract member reference.
62 IMA_Abstract,
63
64 /// The reference may be to an unresolved using declaration and the
65 /// context is not an instance method.
66 IMA_Unresolved_StaticContext,
67
68 // The reference refers to a field which is not a member of the containing
69 // class, which is allowed because we're in C++11 mode and the context is
70 // unevaluated.
71 IMA_Field_Uneval_Context,
72
73 /// All possible referrents are instance members and the current
74 /// context is not an instance method.
75 IMA_Error_StaticContext,
76
77 /// All possible referrents are instance members of an unrelated
78 /// class.
79 IMA_Error_Unrelated
80};
81
82/// The given lookup names class member(s) and is not being used for
83/// an address-of-member expression. Classify the type of access
84/// according to whether it's possible that this reference names an
85/// instance member. This is best-effort in dependent contexts; it is okay to
86/// conservatively answer "yes", in which case some errors will simply
87/// not be caught until template-instantiation.
88static IMAKind ClassifyImplicitMemberAccess(Sema &SemaRef,
89 const LookupResult &R) {
90 assert(!R.empty() && (*R.begin())->isCXXClassMember())((void)0);
91
92 DeclContext *DC = SemaRef.getFunctionLevelDeclContext();
93
94 bool isStaticContext = SemaRef.CXXThisTypeOverride.isNull() &&
95 (!isa<CXXMethodDecl>(DC) || cast<CXXMethodDecl>(DC)->isStatic());
96
97 if (R.isUnresolvableResult())
98 return isStaticContext ? IMA_Unresolved_StaticContext : IMA_Unresolved;
99
100 // Collect all the declaring classes of instance members we find.
101 bool hasNonInstance = false;
102 bool isField = false;
103 BaseSet Classes;
104 for (NamedDecl *D : R) {
105 // Look through any using decls.
106 D = D->getUnderlyingDecl();
107
108 if (D->isCXXInstanceMember()) {
109 isField |= isa<FieldDecl>(D) || isa<MSPropertyDecl>(D) ||
110 isa<IndirectFieldDecl>(D);
111
112 CXXRecordDecl *R = cast<CXXRecordDecl>(D->getDeclContext());
113 Classes.insert(R->getCanonicalDecl());
114 } else
115 hasNonInstance = true;
116 }
117
118 // If we didn't find any instance members, it can't be an implicit
119 // member reference.
120 if (Classes.empty())
121 return IMA_Static;
122
123 // C++11 [expr.prim.general]p12:
124 // An id-expression that denotes a non-static data member or non-static
125 // member function of a class can only be used:
126 // (...)
127 // - if that id-expression denotes a non-static data member and it
128 // appears in an unevaluated operand.
129 //
130 // This rule is specific to C++11. However, we also permit this form
131 // in unevaluated inline assembly operands, like the operand to a SIZE.
132 IMAKind AbstractInstanceResult = IMA_Static; // happens to be 'false'
133 assert(!AbstractInstanceResult)((void)0);
134 switch (SemaRef.ExprEvalContexts.back().Context) {
135 case Sema::ExpressionEvaluationContext::Unevaluated:
136 case Sema::ExpressionEvaluationContext::UnevaluatedList:
137 if (isField && SemaRef.getLangOpts().CPlusPlus11)
138 AbstractInstanceResult = IMA_Field_Uneval_Context;
139 break;
140
141 case Sema::ExpressionEvaluationContext::UnevaluatedAbstract:
142 AbstractInstanceResult = IMA_Abstract;
143 break;
144
145 case Sema::ExpressionEvaluationContext::DiscardedStatement:
146 case Sema::ExpressionEvaluationContext::ConstantEvaluated:
147 case Sema::ExpressionEvaluationContext::PotentiallyEvaluated:
148 case Sema::ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed:
149 break;
150 }
151
152 // If the current context is not an instance method, it can't be
153 // an implicit member reference.
154 if (isStaticContext) {
155 if (hasNonInstance)
156 return IMA_Mixed_StaticContext;
157
158 return AbstractInstanceResult ? AbstractInstanceResult
159 : IMA_Error_StaticContext;
160 }
161
162 CXXRecordDecl *contextClass;
163 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(DC))
164 contextClass = MD->getParent()->getCanonicalDecl();
165 else
166 contextClass = cast<CXXRecordDecl>(DC);
167
168 // [class.mfct.non-static]p3:
169 // ...is used in the body of a non-static member function of class X,
170 // if name lookup (3.4.1) resolves the name in the id-expression to a
171 // non-static non-type member of some class C [...]
172 // ...if C is not X or a base class of X, the class member access expression
173 // is ill-formed.
174 if (R.getNamingClass() &&
175 contextClass->getCanonicalDecl() !=
176 R.getNamingClass()->getCanonicalDecl()) {
177 // If the naming class is not the current context, this was a qualified
178 // member name lookup, and it's sufficient to check that we have the naming
179 // class as a base class.
180 Classes.clear();
181 Classes.insert(R.getNamingClass()->getCanonicalDecl());
182 }
183
184 // If we can prove that the current context is unrelated to all the
185 // declaring classes, it can't be an implicit member reference (in
186 // which case it's an error if any of those members are selected).
187 if (isProvablyNotDerivedFrom(SemaRef, contextClass, Classes))
188 return hasNonInstance ? IMA_Mixed_Unrelated :
189 AbstractInstanceResult ? AbstractInstanceResult :
190 IMA_Error_Unrelated;
191
192 return (hasNonInstance ? IMA_Mixed : IMA_Instance);
193}
194
195/// Diagnose a reference to a field with no object available.
196static void diagnoseInstanceReference(Sema &SemaRef,
197 const CXXScopeSpec &SS,
198 NamedDecl *Rep,
199 const DeclarationNameInfo &nameInfo) {
200 SourceLocation Loc = nameInfo.getLoc();
201 SourceRange Range(Loc);
202 if (SS.isSet()) Range.setBegin(SS.getRange().getBegin());
203
204 // Look through using shadow decls and aliases.
205 Rep = Rep->getUnderlyingDecl();
206
207 DeclContext *FunctionLevelDC = SemaRef.getFunctionLevelDeclContext();
208 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FunctionLevelDC);
209 CXXRecordDecl *ContextClass = Method ? Method->getParent() : nullptr;
210 CXXRecordDecl *RepClass = dyn_cast<CXXRecordDecl>(Rep->getDeclContext());
211
212 bool InStaticMethod = Method && Method->isStatic();
213 bool IsField = isa<FieldDecl>(Rep) || isa<IndirectFieldDecl>(Rep);
214
215 if (IsField && InStaticMethod)
216 // "invalid use of member 'x' in static member function"
217 SemaRef.Diag(Loc, diag::err_invalid_member_use_in_static_method)
218 << Range << nameInfo.getName();
219 else if (ContextClass && RepClass && SS.isEmpty() && !InStaticMethod &&
220 !RepClass->Equals(ContextClass) && RepClass->Encloses(ContextClass))
221 // Unqualified lookup in a non-static member function found a member of an
222 // enclosing class.
223 SemaRef.Diag(Loc, diag::err_nested_non_static_member_use)
224 << IsField << RepClass << nameInfo.getName() << ContextClass << Range;
225 else if (IsField)
226 SemaRef.Diag(Loc, diag::err_invalid_non_static_member_use)
227 << nameInfo.getName() << Range;
228 else
229 SemaRef.Diag(Loc, diag::err_member_call_without_object)
230 << Range;
231}
232
233/// Builds an expression which might be an implicit member expression.
234ExprResult Sema::BuildPossibleImplicitMemberExpr(
235 const CXXScopeSpec &SS, SourceLocation TemplateKWLoc, LookupResult &R,
236 const TemplateArgumentListInfo *TemplateArgs, const Scope *S,
237 UnresolvedLookupExpr *AsULE) {
238 switch (ClassifyImplicitMemberAccess(*this, R)) {
239 case IMA_Instance:
240 return BuildImplicitMemberExpr(SS, TemplateKWLoc, R, TemplateArgs, true, S);
241
242 case IMA_Mixed:
243 case IMA_Mixed_Unrelated:
244 case IMA_Unresolved:
245 return BuildImplicitMemberExpr(SS, TemplateKWLoc, R, TemplateArgs, false,
246 S);
247
248 case IMA_Field_Uneval_Context:
249 Diag(R.getNameLoc(), diag::warn_cxx98_compat_non_static_member_use)
250 << R.getLookupNameInfo().getName();
251 LLVM_FALLTHROUGH[[gnu::fallthrough]];
252 case IMA_Static:
253 case IMA_Abstract:
254 case IMA_Mixed_StaticContext:
255 case IMA_Unresolved_StaticContext:
256 if (TemplateArgs || TemplateKWLoc.isValid())
257 return BuildTemplateIdExpr(SS, TemplateKWLoc, R, false, TemplateArgs);
258 return AsULE ? AsULE : BuildDeclarationNameExpr(SS, R, false);
259
260 case IMA_Error_StaticContext:
261 case IMA_Error_Unrelated:
262 diagnoseInstanceReference(*this, SS, R.getRepresentativeDecl(),
263 R.getLookupNameInfo());
264 return ExprError();
265 }
266
267 llvm_unreachable("unexpected instance member access kind")__builtin_unreachable();
268}
269
270/// Determine whether input char is from rgba component set.
271static bool
272IsRGBA(char c) {
273 switch (c) {
274 case 'r':
275 case 'g':
276 case 'b':
277 case 'a':
278 return true;
279 default:
280 return false;
281 }
282}
283
284// OpenCL v1.1, s6.1.7
285// The component swizzle length must be in accordance with the acceptable
286// vector sizes.
287static bool IsValidOpenCLComponentSwizzleLength(unsigned len)
288{
289 return (len >= 1 && len <= 4) || len == 8 || len == 16;
290}
291
292/// Check an ext-vector component access expression.
293///
294/// VK should be set in advance to the value kind of the base
295/// expression.
296static QualType
297CheckExtVectorComponent(Sema &S, QualType baseType, ExprValueKind &VK,
298 SourceLocation OpLoc, const IdentifierInfo *CompName,
299 SourceLocation CompLoc) {
300 // FIXME: Share logic with ExtVectorElementExpr::containsDuplicateElements,
301 // see FIXME there.
302 //
303 // FIXME: This logic can be greatly simplified by splitting it along
304 // halving/not halving and reworking the component checking.
305 const ExtVectorType *vecType = baseType->getAs<ExtVectorType>();
16
Assuming the object is not a 'ExtVectorType'
17
'vecType' initialized to a null pointer value
306
307 // The vector accessor can't exceed the number of elements.
308 const char *compStr = CompName->getNameStart();
309
310 // This flag determines whether or not the component is one of the four
311 // special names that indicate a subset of exactly half the elements are
312 // to be selected.
313 bool HalvingSwizzle = false;
314
315 // This flag determines whether or not CompName has an 's' char prefix,
316 // indicating that it is a string of hex values to be used as vector indices.
317 bool HexSwizzle = (*compStr == 's' || *compStr == 'S') && compStr[1];
18
Assuming the condition is false
19
Assuming the condition is false
318
319 bool HasRepeated = false;
320 bool HasIndex[16] = {};
321
322 int Idx;
323
324 // Check that we've found one of the special components, or that the component
325 // names must come from the same set.
326 if (!strcmp(compStr, "hi") || !strcmp(compStr, "lo") ||
20
Assuming the condition is false
21
Assuming the condition is false
24
Taking false branch
327 !strcmp(compStr, "even") || !strcmp(compStr, "odd")) {
22
Assuming the condition is false
23
Assuming the condition is false
328 HalvingSwizzle = true;
329 } else if (!HexSwizzle
24.1
'HexSwizzle' is false
&&
25
Taking false branch
330 (Idx = vecType->getPointAccessorIdx(*compStr)) != -1) {
331 bool HasRGBA = IsRGBA(*compStr);
332 do {
333 // Ensure that xyzw and rgba components don't intermingle.
334 if (HasRGBA != IsRGBA(*compStr))
335 break;
336 if (HasIndex[Idx]) HasRepeated = true;
337 HasIndex[Idx] = true;
338 compStr++;
339 } while (*compStr && (Idx = vecType->getPointAccessorIdx(*compStr)) != -1);
340
341 // Emit a warning if an rgba selector is used earlier than OpenCL C 3.0.
342 if (HasRGBA || (*compStr && IsRGBA(*compStr))) {
343 if (S.getLangOpts().OpenCL && S.getLangOpts().OpenCLVersion < 300) {
344 const char *DiagBegin = HasRGBA ? CompName->getNameStart() : compStr;
345 S.Diag(OpLoc, diag::ext_opencl_ext_vector_type_rgba_selector)
346 << StringRef(DiagBegin, 1) << SourceRange(CompLoc);
347 }
348 }
349 } else {
350 if (HexSwizzle
25.1
'HexSwizzle' is false
) compStr++;
26
Taking false branch
351 while ((Idx = vecType->getNumericAccessorIdx(*compStr)) != -1) {
27
Loop condition is true. Entering loop body
29
Loop condition is false. Execution continues on line 358
352 if (HasIndex[Idx]) HasRepeated = true;
28
Taking false branch
353 HasIndex[Idx] = true;
354 compStr++;
355 }
356 }
357
358 if (!HalvingSwizzle
29.1
'HalvingSwizzle' is false
&& *compStr) {
30
Assuming the condition is false
31
Taking false branch
359 // We didn't get to the end of the string. This means the component names
360 // didn't come from the same set *or* we encountered an illegal name.
361 S.Diag(OpLoc, diag::err_ext_vector_component_name_illegal)
362 << StringRef(compStr, 1) << SourceRange(CompLoc);
363 return QualType();
364 }
365
366 // Ensure no component accessor exceeds the width of the vector type it
367 // operates on.
368 if (!HalvingSwizzle
31.1
'HalvingSwizzle' is false
) {
32
Taking true branch
369 compStr = CompName->getNameStart();
370
371 if (HexSwizzle
32.1
'HexSwizzle' is false
)
33
Taking false branch
372 compStr++;
373
374 while (*compStr) {
34
Loop condition is true. Entering loop body
375 if (!vecType->isAccessorWithinNumElements(*compStr++, HexSwizzle)) {
35
Called C++ object pointer is null
376 S.Diag(OpLoc, diag::err_ext_vector_component_exceeds_length)
377 << baseType << SourceRange(CompLoc);
378 return QualType();
379 }
380 }
381 }
382
383 // OpenCL mode requires swizzle length to be in accordance with accepted
384 // sizes. Clang however supports arbitrary lengths for other languages.
385 if (S.getLangOpts().OpenCL && !HalvingSwizzle) {
386 unsigned SwizzleLength = CompName->getLength();
387
388 if (HexSwizzle)
389 SwizzleLength--;
390
391 if (IsValidOpenCLComponentSwizzleLength(SwizzleLength) == false) {
392 S.Diag(OpLoc, diag::err_opencl_ext_vector_component_invalid_length)
393 << SwizzleLength << SourceRange(CompLoc);
394 return QualType();
395 }
396 }
397
398 // The component accessor looks fine - now we need to compute the actual type.
399 // The vector type is implied by the component accessor. For example,
400 // vec4.b is a float, vec4.xy is a vec2, vec4.rgb is a vec3, etc.
401 // vec4.s0 is a float, vec4.s23 is a vec3, etc.
402 // vec4.hi, vec4.lo, vec4.e, and vec4.o all return vec2.
403 unsigned CompSize = HalvingSwizzle ? (vecType->getNumElements() + 1) / 2
404 : CompName->getLength();
405 if (HexSwizzle)
406 CompSize--;
407
408 if (CompSize == 1)
409 return vecType->getElementType();
410
411 if (HasRepeated)
412 VK = VK_PRValue;
413
414 QualType VT = S.Context.getExtVectorType(vecType->getElementType(), CompSize);
415 // Now look up the TypeDefDecl from the vector type. Without this,
416 // diagostics look bad. We want extended vector types to appear built-in.
417 for (Sema::ExtVectorDeclsType::iterator
418 I = S.ExtVectorDecls.begin(S.getExternalSource()),
419 E = S.ExtVectorDecls.end();
420 I != E; ++I) {
421 if ((*I)->getUnderlyingType() == VT)
422 return S.Context.getTypedefType(*I);
423 }
424
425 return VT; // should never get here (a typedef type should always be found).
426}
427
428static Decl *FindGetterSetterNameDeclFromProtocolList(const ObjCProtocolDecl*PDecl,
429 IdentifierInfo *Member,
430 const Selector &Sel,
431 ASTContext &Context) {
432 if (Member)
433 if (ObjCPropertyDecl *PD = PDecl->FindPropertyDeclaration(
434 Member, ObjCPropertyQueryKind::OBJC_PR_query_instance))
435 return PD;
436 if (ObjCMethodDecl *OMD = PDecl->getInstanceMethod(Sel))
437 return OMD;
438
439 for (const auto *I : PDecl->protocols()) {
440 if (Decl *D = FindGetterSetterNameDeclFromProtocolList(I, Member, Sel,
441 Context))
442 return D;
443 }
444 return nullptr;
445}
446
447static Decl *FindGetterSetterNameDecl(const ObjCObjectPointerType *QIdTy,
448 IdentifierInfo *Member,
449 const Selector &Sel,
450 ASTContext &Context) {
451 // Check protocols on qualified interfaces.
452 Decl *GDecl = nullptr;
453 for (const auto *I : QIdTy->quals()) {
454 if (Member)
455 if (ObjCPropertyDecl *PD = I->FindPropertyDeclaration(
456 Member, ObjCPropertyQueryKind::OBJC_PR_query_instance)) {
457 GDecl = PD;
458 break;
459 }
460 // Also must look for a getter or setter name which uses property syntax.
461 if (ObjCMethodDecl *OMD = I->getInstanceMethod(Sel)) {
462 GDecl = OMD;
463 break;
464 }
465 }
466 if (!GDecl) {
467 for (const auto *I : QIdTy->quals()) {
468 // Search in the protocol-qualifier list of current protocol.
469 GDecl = FindGetterSetterNameDeclFromProtocolList(I, Member, Sel, Context);
470 if (GDecl)
471 return GDecl;
472 }
473 }
474 return GDecl;
475}
476
477ExprResult
478Sema::ActOnDependentMemberExpr(Expr *BaseExpr, QualType BaseType,
479 bool IsArrow, SourceLocation OpLoc,
480 const CXXScopeSpec &SS,
481 SourceLocation TemplateKWLoc,
482 NamedDecl *FirstQualifierInScope,
483 const DeclarationNameInfo &NameInfo,
484 const TemplateArgumentListInfo *TemplateArgs) {
485 // Even in dependent contexts, try to diagnose base expressions with
486 // obviously wrong types, e.g.:
487 //
488 // T* t;
489 // t.f;
490 //
491 // In Obj-C++, however, the above expression is valid, since it could be
492 // accessing the 'f' property if T is an Obj-C interface. The extra check
493 // allows this, while still reporting an error if T is a struct pointer.
494 if (!IsArrow) {
495 const PointerType *PT = BaseType->getAs<PointerType>();
496 if (PT && (!getLangOpts().ObjC ||
497 PT->getPointeeType()->isRecordType())) {
498 assert(BaseExpr && "cannot happen with implicit member accesses")((void)0);
499 Diag(OpLoc, diag::err_typecheck_member_reference_struct_union)
500 << BaseType << BaseExpr->getSourceRange() << NameInfo.getSourceRange();
501 return ExprError();
502 }
503 }
504
505 assert(BaseType->isDependentType() ||((void)0)
506 NameInfo.getName().isDependentName() ||((void)0)
507 isDependentScopeSpecifier(SS))((void)0);
508
509 // Get the type being accessed in BaseType. If this is an arrow, the BaseExpr
510 // must have pointer type, and the accessed type is the pointee.
511 return CXXDependentScopeMemberExpr::Create(
512 Context, BaseExpr, BaseType, IsArrow, OpLoc,
513 SS.getWithLocInContext(Context), TemplateKWLoc, FirstQualifierInScope,
514 NameInfo, TemplateArgs);
515}
516
517/// We know that the given qualified member reference points only to
518/// declarations which do not belong to the static type of the base
519/// expression. Diagnose the problem.
520static void DiagnoseQualifiedMemberReference(Sema &SemaRef,
521 Expr *BaseExpr,
522 QualType BaseType,
523 const CXXScopeSpec &SS,
524 NamedDecl *rep,
525 const DeclarationNameInfo &nameInfo) {
526 // If this is an implicit member access, use a different set of
527 // diagnostics.
528 if (!BaseExpr)
529 return diagnoseInstanceReference(SemaRef, SS, rep, nameInfo);
530
531 SemaRef.Diag(nameInfo.getLoc(), diag::err_qualified_member_of_unrelated)
532 << SS.getRange() << rep << BaseType;
533}
534
535// Check whether the declarations we found through a nested-name
536// specifier in a member expression are actually members of the base
537// type. The restriction here is:
538//
539// C++ [expr.ref]p2:
540// ... In these cases, the id-expression shall name a
541// member of the class or of one of its base classes.
542//
543// So it's perfectly legitimate for the nested-name specifier to name
544// an unrelated class, and for us to find an overload set including
545// decls from classes which are not superclasses, as long as the decl
546// we actually pick through overload resolution is from a superclass.
547bool Sema::CheckQualifiedMemberReference(Expr *BaseExpr,
548 QualType BaseType,
549 const CXXScopeSpec &SS,
550 const LookupResult &R) {
551 CXXRecordDecl *BaseRecord =
552 cast_or_null<CXXRecordDecl>(computeDeclContext(BaseType));
553 if (!BaseRecord) {
554 // We can't check this yet because the base type is still
555 // dependent.
556 assert(BaseType->isDependentType())((void)0);
557 return false;
558 }
559
560 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
561 // If this is an implicit member reference and we find a
562 // non-instance member, it's not an error.
563 if (!BaseExpr && !(*I)->isCXXInstanceMember())
564 return false;
565
566 // Note that we use the DC of the decl, not the underlying decl.
567 DeclContext *DC = (*I)->getDeclContext();
568 while (DC->isTransparentContext())
569 DC = DC->getParent();
570
571 if (!DC->isRecord())
572 continue;
573
574 CXXRecordDecl *MemberRecord = cast<CXXRecordDecl>(DC)->getCanonicalDecl();
575 if (BaseRecord->getCanonicalDecl() == MemberRecord ||
576 !BaseRecord->isProvablyNotDerivedFrom(MemberRecord))
577 return false;
578 }
579
580 DiagnoseQualifiedMemberReference(*this, BaseExpr, BaseType, SS,
581 R.getRepresentativeDecl(),
582 R.getLookupNameInfo());
583 return true;
584}
585
586namespace {
587
588// Callback to only accept typo corrections that are either a ValueDecl or a
589// FunctionTemplateDecl and are declared in the current record or, for a C++
590// classes, one of its base classes.
591class RecordMemberExprValidatorCCC final : public CorrectionCandidateCallback {
592public:
593 explicit RecordMemberExprValidatorCCC(const RecordType *RTy)
594 : Record(RTy->getDecl()) {
595 // Don't add bare keywords to the consumer since they will always fail
596 // validation by virtue of not being associated with any decls.
597 WantTypeSpecifiers = false;
598 WantExpressionKeywords = false;
599 WantCXXNamedCasts = false;
600 WantFunctionLikeCasts = false;
601 WantRemainingKeywords = false;
602 }
603
604 bool ValidateCandidate(const TypoCorrection &candidate) override {
605 NamedDecl *ND = candidate.getCorrectionDecl();
606 // Don't accept candidates that cannot be member functions, constants,
607 // variables, or templates.
608 if (!ND || !(isa<ValueDecl>(ND) || isa<FunctionTemplateDecl>(ND)))
609 return false;
610
611 // Accept candidates that occur in the current record.
612 if (Record->containsDecl(ND))
613 return true;
614
615 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Record)) {
616 // Accept candidates that occur in any of the current class' base classes.
617 for (const auto &BS : RD->bases()) {
618 if (const RecordType *BSTy =
619 dyn_cast_or_null<RecordType>(BS.getType().getTypePtrOrNull())) {
620 if (BSTy->getDecl()->containsDecl(ND))
621 return true;
622 }
623 }
624 }
625
626 return false;
627 }
628
629 std::unique_ptr<CorrectionCandidateCallback> clone() override {
630 return std::make_unique<RecordMemberExprValidatorCCC>(*this);
631 }
632
633private:
634 const RecordDecl *const Record;
635};
636
637}
638
639static bool LookupMemberExprInRecord(Sema &SemaRef, LookupResult &R,
640 Expr *BaseExpr,
641 const RecordType *RTy,
642 SourceLocation OpLoc, bool IsArrow,
643 CXXScopeSpec &SS, bool HasTemplateArgs,
644 SourceLocation TemplateKWLoc,
645 TypoExpr *&TE) {
646 SourceRange BaseRange = BaseExpr ? BaseExpr->getSourceRange() : SourceRange();
647 RecordDecl *RDecl = RTy->getDecl();
648 if (!SemaRef.isThisOutsideMemberFunctionBody(QualType(RTy, 0)) &&
649 SemaRef.RequireCompleteType(OpLoc, QualType(RTy, 0),
650 diag::err_typecheck_incomplete_tag,
651 BaseRange))
652 return true;
653
654 if (HasTemplateArgs || TemplateKWLoc.isValid()) {
655 // LookupTemplateName doesn't expect these both to exist simultaneously.
656 QualType ObjectType = SS.isSet() ? QualType() : QualType(RTy, 0);
657
658 bool MOUS;
659 return SemaRef.LookupTemplateName(R, nullptr, SS, ObjectType, false, MOUS,
660 TemplateKWLoc);
661 }
662
663 DeclContext *DC = RDecl;
664 if (SS.isSet()) {
665 // If the member name was a qualified-id, look into the
666 // nested-name-specifier.
667 DC = SemaRef.computeDeclContext(SS, false);
668
669 if (SemaRef.RequireCompleteDeclContext(SS, DC)) {
670 SemaRef.Diag(SS.getRange().getEnd(), diag::err_typecheck_incomplete_tag)
671 << SS.getRange() << DC;
672 return true;
673 }
674
675 assert(DC && "Cannot handle non-computable dependent contexts in lookup")((void)0);
676
677 if (!isa<TypeDecl>(DC)) {
678 SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_nonclass)
679 << DC << SS.getRange();
680 return true;
681 }
682 }
683
684 // The record definition is complete, now look up the member.
685 SemaRef.LookupQualifiedName(R, DC, SS);
686
687 if (!R.empty())
688 return false;
689
690 DeclarationName Typo = R.getLookupName();
691 SourceLocation TypoLoc = R.getNameLoc();
692
693 struct QueryState {
694 Sema &SemaRef;
695 DeclarationNameInfo NameInfo;
696 Sema::LookupNameKind LookupKind;
697 Sema::RedeclarationKind Redecl;
698 };
699 QueryState Q = {R.getSema(), R.getLookupNameInfo(), R.getLookupKind(),
700 R.redeclarationKind()};
701 RecordMemberExprValidatorCCC CCC(RTy);
702 TE = SemaRef.CorrectTypoDelayed(
703 R.getLookupNameInfo(), R.getLookupKind(), nullptr, &SS, CCC,
704 [=, &SemaRef](const TypoCorrection &TC) {
705 if (TC) {
706 assert(!TC.isKeyword() &&((void)0)
707 "Got a keyword as a correction for a member!")((void)0);
708 bool DroppedSpecifier =
709 TC.WillReplaceSpecifier() &&
710 Typo.getAsString() == TC.getAsString(SemaRef.getLangOpts());
711 SemaRef.diagnoseTypo(TC, SemaRef.PDiag(diag::err_no_member_suggest)
712 << Typo << DC << DroppedSpecifier
713 << SS.getRange());
714 } else {
715 SemaRef.Diag(TypoLoc, diag::err_no_member) << Typo << DC << BaseRange;
716 }
717 },
718 [=](Sema &SemaRef, TypoExpr *TE, TypoCorrection TC) mutable {
719 LookupResult R(Q.SemaRef, Q.NameInfo, Q.LookupKind, Q.Redecl);
720 R.clear(); // Ensure there's no decls lingering in the shared state.
721 R.suppressDiagnostics();
722 R.setLookupName(TC.getCorrection());
723 for (NamedDecl *ND : TC)
724 R.addDecl(ND);
725 R.resolveKind();
726 return SemaRef.BuildMemberReferenceExpr(
727 BaseExpr, BaseExpr->getType(), OpLoc, IsArrow, SS, SourceLocation(),
728 nullptr, R, nullptr, nullptr);
729 },
730 Sema::CTK_ErrorRecovery, DC);
731
732 return false;
733}
734
735static ExprResult LookupMemberExpr(Sema &S, LookupResult &R,
736 ExprResult &BaseExpr, bool &IsArrow,
737 SourceLocation OpLoc, CXXScopeSpec &SS,
738 Decl *ObjCImpDecl, bool HasTemplateArgs,
739 SourceLocation TemplateKWLoc);
740
741ExprResult
742Sema::BuildMemberReferenceExpr(Expr *Base, QualType BaseType,
743 SourceLocation OpLoc, bool IsArrow,
744 CXXScopeSpec &SS,
745 SourceLocation TemplateKWLoc,
746 NamedDecl *FirstQualifierInScope,
747 const DeclarationNameInfo &NameInfo,
748 const TemplateArgumentListInfo *TemplateArgs,
749 const Scope *S,
750 ActOnMemberAccessExtraArgs *ExtraArgs) {
751 if (BaseType->isDependentType() ||
752 (SS.isSet() && isDependentScopeSpecifier(SS)))
753 return ActOnDependentMemberExpr(Base, BaseType,
754 IsArrow, OpLoc,
755 SS, TemplateKWLoc, FirstQualifierInScope,
756 NameInfo, TemplateArgs);
757
758 LookupResult R(*this, NameInfo, LookupMemberName);
759
760 // Implicit member accesses.
761 if (!Base) {
762 TypoExpr *TE = nullptr;
763 QualType RecordTy = BaseType;
764 if (IsArrow) RecordTy = RecordTy->castAs<PointerType>()->getPointeeType();
765 if (LookupMemberExprInRecord(
766 *this, R, nullptr, RecordTy->getAs<RecordType>(), OpLoc, IsArrow,
767 SS, TemplateArgs != nullptr, TemplateKWLoc, TE))
768 return ExprError();
769 if (TE)
770 return TE;
771
772 // Explicit member accesses.
773 } else {
774 ExprResult BaseResult = Base;
775 ExprResult Result =
776 LookupMemberExpr(*this, R, BaseResult, IsArrow, OpLoc, SS,
777 ExtraArgs ? ExtraArgs->ObjCImpDecl : nullptr,
778 TemplateArgs != nullptr, TemplateKWLoc);
779
780 if (BaseResult.isInvalid())
781 return ExprError();
782 Base = BaseResult.get();
783
784 if (Result.isInvalid())
785 return ExprError();
786
787 if (Result.get())
788 return Result;
789
790 // LookupMemberExpr can modify Base, and thus change BaseType
791 BaseType = Base->getType();
792 }
793
794 return BuildMemberReferenceExpr(Base, BaseType,
795 OpLoc, IsArrow, SS, TemplateKWLoc,
796 FirstQualifierInScope, R, TemplateArgs, S,
797 false, ExtraArgs);
798}
799
800ExprResult
801Sema::BuildAnonymousStructUnionMemberReference(const CXXScopeSpec &SS,
802 SourceLocation loc,
803 IndirectFieldDecl *indirectField,
804 DeclAccessPair foundDecl,
805 Expr *baseObjectExpr,
806 SourceLocation opLoc) {
807 // First, build the expression that refers to the base object.
808
809 // Case 1: the base of the indirect field is not a field.
810 VarDecl *baseVariable = indirectField->getVarDecl();
811 CXXScopeSpec EmptySS;
812 if (baseVariable) {
813 assert(baseVariable->getType()->isRecordType())((void)0);
814
815 // In principle we could have a member access expression that
816 // accesses an anonymous struct/union that's a static member of
817 // the base object's class. However, under the current standard,
818 // static data members cannot be anonymous structs or unions.
819 // Supporting this is as easy as building a MemberExpr here.
820 assert(!baseObjectExpr && "anonymous struct/union is static data member?")((void)0);
821
822 DeclarationNameInfo baseNameInfo(DeclarationName(), loc);
823
824 ExprResult result
825 = BuildDeclarationNameExpr(EmptySS, baseNameInfo, baseVariable);
826 if (result.isInvalid()) return ExprError();
827
828 baseObjectExpr = result.get();
829 }
830
831 assert((baseVariable || baseObjectExpr) &&((void)0)
832 "referencing anonymous struct/union without a base variable or "((void)0)
833 "expression")((void)0);
834
835 // Build the implicit member references to the field of the
836 // anonymous struct/union.
837 Expr *result = baseObjectExpr;
838 IndirectFieldDecl::chain_iterator
839 FI = indirectField->chain_begin(), FEnd = indirectField->chain_end();
840
841 // Case 2: the base of the indirect field is a field and the user
842 // wrote a member expression.
843 if (!baseVariable) {
844 FieldDecl *field = cast<FieldDecl>(*FI);
845
846 bool baseObjectIsPointer = baseObjectExpr->getType()->isPointerType();
847
848 // Make a nameInfo that properly uses the anonymous name.
849 DeclarationNameInfo memberNameInfo(field->getDeclName(), loc);
850
851 // Build the first member access in the chain with full information.
852 result =
853 BuildFieldReferenceExpr(result, baseObjectIsPointer, SourceLocation(),
854 SS, field, foundDecl, memberNameInfo)
855 .get();
856 if (!result)
857 return ExprError();
858 }
859
860 // In all cases, we should now skip the first declaration in the chain.
861 ++FI;
862
863 while (FI != FEnd) {
864 FieldDecl *field = cast<FieldDecl>(*FI++);
865
866 // FIXME: these are somewhat meaningless
867 DeclarationNameInfo memberNameInfo(field->getDeclName(), loc);
868 DeclAccessPair fakeFoundDecl =
869 DeclAccessPair::make(field, field->getAccess());
870
871 result =
872 BuildFieldReferenceExpr(result, /*isarrow*/ false, SourceLocation(),
873 (FI == FEnd ? SS : EmptySS), field,
874 fakeFoundDecl, memberNameInfo)
875 .get();
876 }
877
878 return result;
879}
880
881static ExprResult
882BuildMSPropertyRefExpr(Sema &S, Expr *BaseExpr, bool IsArrow,
883 const CXXScopeSpec &SS,
884 MSPropertyDecl *PD,
885 const DeclarationNameInfo &NameInfo) {
886 // Property names are always simple identifiers and therefore never
887 // require any interesting additional storage.
888 return new (S.Context) MSPropertyRefExpr(BaseExpr, PD, IsArrow,
889 S.Context.PseudoObjectTy, VK_LValue,
890 SS.getWithLocInContext(S.Context),
891 NameInfo.getLoc());
892}
893
894MemberExpr *Sema::BuildMemberExpr(
895 Expr *Base, bool IsArrow, SourceLocation OpLoc, const CXXScopeSpec *SS,
896 SourceLocation TemplateKWLoc, ValueDecl *Member, DeclAccessPair FoundDecl,
897 bool HadMultipleCandidates, const DeclarationNameInfo &MemberNameInfo,
898 QualType Ty, ExprValueKind VK, ExprObjectKind OK,
899 const TemplateArgumentListInfo *TemplateArgs) {
900 NestedNameSpecifierLoc NNS =
901 SS ? SS->getWithLocInContext(Context) : NestedNameSpecifierLoc();
902 return BuildMemberExpr(Base, IsArrow, OpLoc, NNS, TemplateKWLoc, Member,
903 FoundDecl, HadMultipleCandidates, MemberNameInfo, Ty,
904 VK, OK, TemplateArgs);
905}
906
907MemberExpr *Sema::BuildMemberExpr(
908 Expr *Base, bool IsArrow, SourceLocation OpLoc, NestedNameSpecifierLoc NNS,
909 SourceLocation TemplateKWLoc, ValueDecl *Member, DeclAccessPair FoundDecl,
910 bool HadMultipleCandidates, const DeclarationNameInfo &MemberNameInfo,
911 QualType Ty, ExprValueKind VK, ExprObjectKind OK,
912 const TemplateArgumentListInfo *TemplateArgs) {
913 assert((!IsArrow || Base->isPRValue()) &&((void)0)
914 "-> base must be a pointer prvalue")((void)0);
915 MemberExpr *E =
916 MemberExpr::Create(Context, Base, IsArrow, OpLoc, NNS, TemplateKWLoc,
917 Member, FoundDecl, MemberNameInfo, TemplateArgs, Ty,
918 VK, OK, getNonOdrUseReasonInCurrentContext(Member));
919 E->setHadMultipleCandidates(HadMultipleCandidates);
920 MarkMemberReferenced(E);
921
922 // C++ [except.spec]p17:
923 // An exception-specification is considered to be needed when:
924 // - in an expression the function is the unique lookup result or the
925 // selected member of a set of overloaded functions
926 if (auto *FPT = Ty->getAs<FunctionProtoType>()) {
927 if (isUnresolvedExceptionSpec(FPT->getExceptionSpecType())) {
928 if (auto *NewFPT = ResolveExceptionSpec(MemberNameInfo.getLoc(), FPT))
929 E->setType(Context.getQualifiedType(NewFPT, Ty.getQualifiers()));
930 }
931 }
932
933 return E;
934}
935
936/// Determine if the given scope is within a function-try-block handler.
937static bool IsInFnTryBlockHandler(const Scope *S) {
938 // Walk the scope stack until finding a FnTryCatchScope, or leave the
939 // function scope. If a FnTryCatchScope is found, check whether the TryScope
940 // flag is set. If it is not, it's a function-try-block handler.
941 for (; S != S->getFnParent(); S = S->getParent()) {
942 if (S->getFlags() & Scope::FnTryCatchScope)
943 return (S->getFlags() & Scope::TryScope) != Scope::TryScope;
944 }
945 return false;
946}
947
948ExprResult
949Sema::BuildMemberReferenceExpr(Expr *BaseExpr, QualType BaseExprType,
950 SourceLocation OpLoc, bool IsArrow,
951 const CXXScopeSpec &SS,
952 SourceLocation TemplateKWLoc,
953 NamedDecl *FirstQualifierInScope,
954 LookupResult &R,
955 const TemplateArgumentListInfo *TemplateArgs,
956 const Scope *S,
957 bool SuppressQualifierCheck,
958 ActOnMemberAccessExtraArgs *ExtraArgs) {
959 QualType BaseType = BaseExprType;
960 if (IsArrow) {
961 assert(BaseType->isPointerType())((void)0);
962 BaseType = BaseType->castAs<PointerType>()->getPointeeType();
963 }
964 R.setBaseObjectType(BaseType);
965
966 // C++1z [expr.ref]p2:
967 // For the first option (dot) the first expression shall be a glvalue [...]
968 if (!IsArrow && BaseExpr && BaseExpr->isPRValue()) {
969 ExprResult Converted = TemporaryMaterializationConversion(BaseExpr);
970 if (Converted.isInvalid())
971 return ExprError();
972 BaseExpr = Converted.get();
973 }
974
975 const DeclarationNameInfo &MemberNameInfo = R.getLookupNameInfo();
976 DeclarationName MemberName = MemberNameInfo.getName();
977 SourceLocation MemberLoc = MemberNameInfo.getLoc();
978
979 if (R.isAmbiguous())
980 return ExprError();
981
982 // [except.handle]p10: Referring to any non-static member or base class of an
983 // object in the handler for a function-try-block of a constructor or
984 // destructor for that object results in undefined behavior.
985 const auto *FD = getCurFunctionDecl();
986 if (S && BaseExpr && FD &&
987 (isa<CXXDestructorDecl>(FD) || isa<CXXConstructorDecl>(FD)) &&
988 isa<CXXThisExpr>(BaseExpr->IgnoreImpCasts()) &&
989 IsInFnTryBlockHandler(S))
990 Diag(MemberLoc, diag::warn_cdtor_function_try_handler_mem_expr)
991 << isa<CXXDestructorDecl>(FD);
992
993 if (R.empty()) {
994 // Rederive where we looked up.
995 DeclContext *DC = (SS.isSet()
996 ? computeDeclContext(SS, false)
997 : BaseType->castAs<RecordType>()->getDecl());
998
999 if (ExtraArgs) {
1000 ExprResult RetryExpr;
1001 if (!IsArrow && BaseExpr) {
1002 SFINAETrap Trap(*this, true);
1003 ParsedType ObjectType;
1004 bool MayBePseudoDestructor = false;
1005 RetryExpr = ActOnStartCXXMemberReference(getCurScope(), BaseExpr,
1006 OpLoc, tok::arrow, ObjectType,
1007 MayBePseudoDestructor);
1008 if (RetryExpr.isUsable() && !Trap.hasErrorOccurred()) {
1009 CXXScopeSpec TempSS(SS);
1010 RetryExpr = ActOnMemberAccessExpr(
1011 ExtraArgs->S, RetryExpr.get(), OpLoc, tok::arrow, TempSS,
1012 TemplateKWLoc, ExtraArgs->Id, ExtraArgs->ObjCImpDecl);
1013 }
1014 if (Trap.hasErrorOccurred())
1015 RetryExpr = ExprError();
1016 }
1017 if (RetryExpr.isUsable()) {
1018 Diag(OpLoc, diag::err_no_member_overloaded_arrow)
1019 << MemberName << DC << FixItHint::CreateReplacement(OpLoc, "->");
1020 return RetryExpr;
1021 }
1022 }
1023
1024 Diag(R.getNameLoc(), diag::err_no_member)
1025 << MemberName << DC
1026 << (BaseExpr ? BaseExpr->getSourceRange() : SourceRange());
1027 return ExprError();
1028 }
1029
1030 // Diagnose lookups that find only declarations from a non-base
1031 // type. This is possible for either qualified lookups (which may
1032 // have been qualified with an unrelated type) or implicit member
1033 // expressions (which were found with unqualified lookup and thus
1034 // may have come from an enclosing scope). Note that it's okay for
1035 // lookup to find declarations from a non-base type as long as those
1036 // aren't the ones picked by overload resolution.
1037 if ((SS.isSet() || !BaseExpr ||
1038 (isa<CXXThisExpr>(BaseExpr) &&
1039 cast<CXXThisExpr>(BaseExpr)->isImplicit())) &&
1040 !SuppressQualifierCheck &&
1041 CheckQualifiedMemberReference(BaseExpr, BaseType, SS, R))
1042 return ExprError();
1043
1044 // Construct an unresolved result if we in fact got an unresolved
1045 // result.
1046 if (R.isOverloadedResult() || R.isUnresolvableResult()) {
1047 // Suppress any lookup-related diagnostics; we'll do these when we
1048 // pick a member.
1049 R.suppressDiagnostics();
1050
1051 UnresolvedMemberExpr *MemExpr
1052 = UnresolvedMemberExpr::Create(Context, R.isUnresolvableResult(),
1053 BaseExpr, BaseExprType,
1054 IsArrow, OpLoc,
1055 SS.getWithLocInContext(Context),
1056 TemplateKWLoc, MemberNameInfo,
1057 TemplateArgs, R.begin(), R.end());
1058
1059 return MemExpr;
1060 }
1061
1062 assert(R.isSingleResult())((void)0);
1063 DeclAccessPair FoundDecl = R.begin().getPair();
1064 NamedDecl *MemberDecl = R.getFoundDecl();
1065
1066 // FIXME: diagnose the presence of template arguments now.
1067
1068 // If the decl being referenced had an error, return an error for this
1069 // sub-expr without emitting another error, in order to avoid cascading
1070 // error cases.
1071 if (MemberDecl->isInvalidDecl())
1072 return ExprError();
1073
1074 // Handle the implicit-member-access case.
1075 if (!BaseExpr) {
1076 // If this is not an instance member, convert to a non-member access.
1077 if (!MemberDecl->isCXXInstanceMember()) {
1078 // We might have a variable template specialization (or maybe one day a
1079 // member concept-id).
1080 if (TemplateArgs || TemplateKWLoc.isValid())
1081 return BuildTemplateIdExpr(SS, TemplateKWLoc, R, /*ADL*/false, TemplateArgs);
1082
1083 return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), MemberDecl,
1084 FoundDecl, TemplateArgs);
1085 }
1086 SourceLocation Loc = R.getNameLoc();
1087 if (SS.getRange().isValid())
1088 Loc = SS.getRange().getBegin();
1089 BaseExpr = BuildCXXThisExpr(Loc, BaseExprType, /*IsImplicit=*/true);
1090 }
1091
1092 // Check the use of this member.
1093 if (DiagnoseUseOfDecl(MemberDecl, MemberLoc))
1094 return ExprError();
1095
1096 if (FieldDecl *FD = dyn_cast<FieldDecl>(MemberDecl))
1097 return BuildFieldReferenceExpr(BaseExpr, IsArrow, OpLoc, SS, FD, FoundDecl,
1098 MemberNameInfo);
1099
1100 if (MSPropertyDecl *PD = dyn_cast<MSPropertyDecl>(MemberDecl))
1101 return BuildMSPropertyRefExpr(*this, BaseExpr, IsArrow, SS, PD,
1102 MemberNameInfo);
1103
1104 if (IndirectFieldDecl *FD = dyn_cast<IndirectFieldDecl>(MemberDecl))
1105 // We may have found a field within an anonymous union or struct
1106 // (C++ [class.union]).
1107 return BuildAnonymousStructUnionMemberReference(SS, MemberLoc, FD,
1108 FoundDecl, BaseExpr,
1109 OpLoc);
1110
1111 if (VarDecl *Var = dyn_cast<VarDecl>(MemberDecl)) {
1112 return BuildMemberExpr(BaseExpr, IsArrow, OpLoc, &SS, TemplateKWLoc, Var,
1113 FoundDecl, /*HadMultipleCandidates=*/false,
1114 MemberNameInfo, Var->getType().getNonReferenceType(),
1115 VK_LValue, OK_Ordinary);
1116 }
1117
1118 if (CXXMethodDecl *MemberFn = dyn_cast<CXXMethodDecl>(MemberDecl)) {
1119 ExprValueKind valueKind;
1120 QualType type;
1121 if (MemberFn->isInstance()) {
1122 valueKind = VK_PRValue;
1123 type = Context.BoundMemberTy;
1124 } else {
1125 valueKind = VK_LValue;
1126 type = MemberFn->getType();
1127 }
1128
1129 return BuildMemberExpr(BaseExpr, IsArrow, OpLoc, &SS, TemplateKWLoc,
1130 MemberFn, FoundDecl, /*HadMultipleCandidates=*/false,
1131 MemberNameInfo, type, valueKind, OK_Ordinary);
1132 }
1133 assert(!isa<FunctionDecl>(MemberDecl) && "member function not C++ method?")((void)0);
1134
1135 if (EnumConstantDecl *Enum = dyn_cast<EnumConstantDecl>(MemberDecl)) {
1136 return BuildMemberExpr(BaseExpr, IsArrow, OpLoc, &SS, TemplateKWLoc, Enum,
1137 FoundDecl, /*HadMultipleCandidates=*/false,
1138 MemberNameInfo, Enum->getType(), VK_PRValue,
1139 OK_Ordinary);
1140 }
1141
1142 if (VarTemplateDecl *VarTempl = dyn_cast<VarTemplateDecl>(MemberDecl)) {
1143 if (!TemplateArgs) {
1144 diagnoseMissingTemplateArguments(TemplateName(VarTempl), MemberLoc);
1145 return ExprError();
1146 }
1147
1148 DeclResult VDecl = CheckVarTemplateId(VarTempl, TemplateKWLoc,
1149 MemberNameInfo.getLoc(), *TemplateArgs);
1150 if (VDecl.isInvalid())
1151 return ExprError();
1152
1153 // Non-dependent member, but dependent template arguments.
1154 if (!VDecl.get())
1155 return ActOnDependentMemberExpr(
1156 BaseExpr, BaseExpr->getType(), IsArrow, OpLoc, SS, TemplateKWLoc,
1157 FirstQualifierInScope, MemberNameInfo, TemplateArgs);
1158
1159 VarDecl *Var = cast<VarDecl>(VDecl.get());
1160 if (!Var->getTemplateSpecializationKind())
1161 Var->setTemplateSpecializationKind(TSK_ImplicitInstantiation, MemberLoc);
1162
1163 return BuildMemberExpr(
1164 BaseExpr, IsArrow, OpLoc, &SS, TemplateKWLoc, Var, FoundDecl,
1165 /*HadMultipleCandidates=*/false, MemberNameInfo,
1166 Var->getType().getNonReferenceType(), VK_LValue, OK_Ordinary);
1167 }
1168
1169 // We found something that we didn't expect. Complain.
1170 if (isa<TypeDecl>(MemberDecl))
1171 Diag(MemberLoc, diag::err_typecheck_member_reference_type)
1172 << MemberName << BaseType << int(IsArrow);
1173 else
1174 Diag(MemberLoc, diag::err_typecheck_member_reference_unknown)
1175 << MemberName << BaseType << int(IsArrow);
1176
1177 Diag(MemberDecl->getLocation(), diag::note_member_declared_here)
1178 << MemberName;
1179 R.suppressDiagnostics();
1180 return ExprError();
1181}
1182
1183/// Given that normal member access failed on the given expression,
1184/// and given that the expression's type involves builtin-id or
1185/// builtin-Class, decide whether substituting in the redefinition
1186/// types would be profitable. The redefinition type is whatever
1187/// this translation unit tried to typedef to id/Class; we store
1188/// it to the side and then re-use it in places like this.
1189static bool ShouldTryAgainWithRedefinitionType(Sema &S, ExprResult &base) {
1190 const ObjCObjectPointerType *opty
1191 = base.get()->getType()->getAs<ObjCObjectPointerType>();
1192 if (!opty) return false;
1193
1194 const ObjCObjectType *ty = opty->getObjectType();
1195
1196 QualType redef;
1197 if (ty->isObjCId()) {
1198 redef = S.Context.getObjCIdRedefinitionType();
1199 } else if (ty->isObjCClass()) {
1200 redef = S.Context.getObjCClassRedefinitionType();
1201 } else {
1202 return false;
1203 }
1204
1205 // Do the substitution as long as the redefinition type isn't just a
1206 // possibly-qualified pointer to builtin-id or builtin-Class again.
1207 opty = redef->getAs<ObjCObjectPointerType>();
1208 if (opty && !opty->getObjectType()->getInterface())
1209 return false;
1210
1211 base = S.ImpCastExprToType(base.get(), redef, CK_BitCast);
1212 return true;
1213}
1214
1215static bool isRecordType(QualType T) {
1216 return T->isRecordType();
1217}
1218static bool isPointerToRecordType(QualType T) {
1219 if (const PointerType *PT = T->getAs<PointerType>())
1220 return PT->getPointeeType()->isRecordType();
1221 return false;
1222}
1223
1224/// Perform conversions on the LHS of a member access expression.
1225ExprResult
1226Sema::PerformMemberExprBaseConversion(Expr *Base, bool IsArrow) {
1227 if (IsArrow && !Base->getType()->isFunctionType())
1228 return DefaultFunctionArrayLvalueConversion(Base);
1229
1230 return CheckPlaceholderExpr(Base);
1231}
1232
1233/// Look up the given member of the given non-type-dependent
1234/// expression. This can return in one of two ways:
1235/// * If it returns a sentinel null-but-valid result, the caller will
1236/// assume that lookup was performed and the results written into
1237/// the provided structure. It will take over from there.
1238/// * Otherwise, the returned expression will be produced in place of
1239/// an ordinary member expression.
1240///
1241/// The ObjCImpDecl bit is a gross hack that will need to be properly
1242/// fixed for ObjC++.
1243static ExprResult LookupMemberExpr(Sema &S, LookupResult &R,
1244 ExprResult &BaseExpr, bool &IsArrow,
1245 SourceLocation OpLoc, CXXScopeSpec &SS,
1246 Decl *ObjCImpDecl, bool HasTemplateArgs,
1247 SourceLocation TemplateKWLoc) {
1248 assert(BaseExpr.get() && "no base expression")((void)0);
1249
1250 // Perform default conversions.
1251 BaseExpr = S.PerformMemberExprBaseConversion(BaseExpr.get(), IsArrow);
1252 if (BaseExpr.isInvalid())
1
Assuming the condition is false
2
Taking false branch
1253 return ExprError();
1254
1255 QualType BaseType = BaseExpr.get()->getType();
1256 assert(!BaseType->isDependentType())((void)0);
1257
1258 DeclarationName MemberName = R.getLookupName();
1259 SourceLocation MemberLoc = R.getNameLoc();
1260
1261 // For later type-checking purposes, turn arrow accesses into dot
1262 // accesses. The only access type we support that doesn't follow
1263 // the C equivalence "a->b === (*a).b" is ObjC property accesses,
1264 // and those never use arrows, so this is unaffected.
1265 if (IsArrow
2.1
'IsArrow' is false
) {
3
Taking false branch
1266 if (const PointerType *Ptr = BaseType->getAs<PointerType>())
1267 BaseType = Ptr->getPointeeType();
1268 else if (const ObjCObjectPointerType *Ptr
1269 = BaseType->getAs<ObjCObjectPointerType>())
1270 BaseType = Ptr->getPointeeType();
1271 else if (BaseType->isRecordType()) {
1272 // Recover from arrow accesses to records, e.g.:
1273 // struct MyRecord foo;
1274 // foo->bar
1275 // This is actually well-formed in C++ if MyRecord has an
1276 // overloaded operator->, but that should have been dealt with
1277 // by now--or a diagnostic message already issued if a problem
1278 // was encountered while looking for the overloaded operator->.
1279 if (!S.getLangOpts().CPlusPlus) {
1280 S.Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
1281 << BaseType << int(IsArrow) << BaseExpr.get()->getSourceRange()
1282 << FixItHint::CreateReplacement(OpLoc, ".");
1283 }
1284 IsArrow = false;
1285 } else if (BaseType->isFunctionType()) {
1286 goto fail;
1287 } else {
1288 S.Diag(MemberLoc, diag::err_typecheck_member_reference_arrow)
1289 << BaseType << BaseExpr.get()->getSourceRange();
1290 return ExprError();
1291 }
1292 }
1293
1294 // Handle field access to simple records.
1295 if (const RecordType *RTy
4.1
'RTy' is null
= BaseType->getAs<RecordType>()) {
4
Assuming the object is not a 'RecordType'
5
Taking false branch
1296 TypoExpr *TE = nullptr;
1297 if (LookupMemberExprInRecord(S, R, BaseExpr.get(), RTy, OpLoc, IsArrow, SS,
1298 HasTemplateArgs, TemplateKWLoc, TE))
1299 return ExprError();
1300
1301 // Returning valid-but-null is how we indicate to the caller that
1302 // the lookup result was filled in. If typo correction was attempted and
1303 // failed, the lookup result will have been cleared--that combined with the
1304 // valid-but-null ExprResult will trigger the appropriate diagnostics.
1305 return ExprResult(TE);
1306 }
1307
1308 // Handle ivar access to Objective-C objects.
1309 if (const ObjCObjectType *OTy
6.1
'OTy' is null
= BaseType->getAs<ObjCObjectType>()) {
6
Assuming the object is not a 'ObjCObjectType'
7
Taking false branch
1310 if (!SS.isEmpty() && !SS.isInvalid()) {
1311 S.Diag(SS.getRange().getBegin(), diag::err_qualified_objc_access)
1312 << 1 << SS.getScopeRep()
1313 << FixItHint::CreateRemoval(SS.getRange());
1314 SS.clear();
1315 }
1316
1317 IdentifierInfo *Member = MemberName.getAsIdentifierInfo();
1318
1319 // There are three cases for the base type:
1320 // - builtin id (qualified or unqualified)
1321 // - builtin Class (qualified or unqualified)
1322 // - an interface
1323 ObjCInterfaceDecl *IDecl = OTy->getInterface();
1324 if (!IDecl) {
1325 if (S.getLangOpts().ObjCAutoRefCount &&
1326 (OTy->isObjCId() || OTy->isObjCClass()))
1327 goto fail;
1328 // There's an implicit 'isa' ivar on all objects.
1329 // But we only actually find it this way on objects of type 'id',
1330 // apparently.
1331 if (OTy->isObjCId() && Member->isStr("isa"))
1332 return new (S.Context) ObjCIsaExpr(BaseExpr.get(), IsArrow, MemberLoc,
1333 OpLoc, S.Context.getObjCClassType());
1334 if (ShouldTryAgainWithRedefinitionType(S, BaseExpr))
1335 return LookupMemberExpr(S, R, BaseExpr, IsArrow, OpLoc, SS,
1336 ObjCImpDecl, HasTemplateArgs, TemplateKWLoc);
1337 goto fail;
1338 }
1339
1340 if (S.RequireCompleteType(OpLoc, BaseType,
1341 diag::err_typecheck_incomplete_tag,
1342 BaseExpr.get()))
1343 return ExprError();
1344
1345 ObjCInterfaceDecl *ClassDeclared = nullptr;
1346 ObjCIvarDecl *IV = IDecl->lookupInstanceVariable(Member, ClassDeclared);
1347
1348 if (!IV) {
1349 // Attempt to correct for typos in ivar names.
1350 DeclFilterCCC<ObjCIvarDecl> Validator{};
1351 Validator.IsObjCIvarLookup = IsArrow;
1352 if (TypoCorrection Corrected = S.CorrectTypo(
1353 R.getLookupNameInfo(), Sema::LookupMemberName, nullptr, nullptr,
1354 Validator, Sema::CTK_ErrorRecovery, IDecl)) {
1355 IV = Corrected.getCorrectionDeclAs<ObjCIvarDecl>();
1356 S.diagnoseTypo(
1357 Corrected,
1358 S.PDiag(diag::err_typecheck_member_reference_ivar_suggest)
1359 << IDecl->getDeclName() << MemberName);
1360
1361 // Figure out the class that declares the ivar.
1362 assert(!ClassDeclared)((void)0);
1363
1364 Decl *D = cast<Decl>(IV->getDeclContext());
1365 if (auto *Category = dyn_cast<ObjCCategoryDecl>(D))
1366 D = Category->getClassInterface();
1367
1368 if (auto *Implementation = dyn_cast<ObjCImplementationDecl>(D))
1369 ClassDeclared = Implementation->getClassInterface();
1370 else if (auto *Interface = dyn_cast<ObjCInterfaceDecl>(D))
1371 ClassDeclared = Interface;
1372
1373 assert(ClassDeclared && "cannot query interface")((void)0);
1374 } else {
1375 if (IsArrow &&
1376 IDecl->FindPropertyDeclaration(
1377 Member, ObjCPropertyQueryKind::OBJC_PR_query_instance)) {
1378 S.Diag(MemberLoc, diag::err_property_found_suggest)
1379 << Member << BaseExpr.get()->getType()
1380 << FixItHint::CreateReplacement(OpLoc, ".");
1381 return ExprError();
1382 }
1383
1384 S.Diag(MemberLoc, diag::err_typecheck_member_reference_ivar)
1385 << IDecl->getDeclName() << MemberName
1386 << BaseExpr.get()->getSourceRange();
1387 return ExprError();
1388 }
1389 }
1390
1391 assert(ClassDeclared)((void)0);
1392
1393 // If the decl being referenced had an error, return an error for this
1394 // sub-expr without emitting another error, in order to avoid cascading
1395 // error cases.
1396 if (IV->isInvalidDecl())
1397 return ExprError();
1398
1399 // Check whether we can reference this field.
1400 if (S.DiagnoseUseOfDecl(IV, MemberLoc))
1401 return ExprError();
1402 if (IV->getAccessControl() != ObjCIvarDecl::Public &&
1403 IV->getAccessControl() != ObjCIvarDecl::Package) {
1404 ObjCInterfaceDecl *ClassOfMethodDecl = nullptr;
1405 if (ObjCMethodDecl *MD = S.getCurMethodDecl())
1406 ClassOfMethodDecl = MD->getClassInterface();
1407 else if (ObjCImpDecl && S.getCurFunctionDecl()) {
1408 // Case of a c-function declared inside an objc implementation.
1409 // FIXME: For a c-style function nested inside an objc implementation
1410 // class, there is no implementation context available, so we pass
1411 // down the context as argument to this routine. Ideally, this context
1412 // need be passed down in the AST node and somehow calculated from the
1413 // AST for a function decl.
1414 if (ObjCImplementationDecl *IMPD =
1415 dyn_cast<ObjCImplementationDecl>(ObjCImpDecl))
1416 ClassOfMethodDecl = IMPD->getClassInterface();
1417 else if (ObjCCategoryImplDecl* CatImplClass =
1418 dyn_cast<ObjCCategoryImplDecl>(ObjCImpDecl))
1419 ClassOfMethodDecl = CatImplClass->getClassInterface();
1420 }
1421 if (!S.getLangOpts().DebuggerSupport) {
1422 if (IV->getAccessControl() == ObjCIvarDecl::Private) {
1423 if (!declaresSameEntity(ClassDeclared, IDecl) ||
1424 !declaresSameEntity(ClassOfMethodDecl, ClassDeclared))
1425 S.Diag(MemberLoc, diag::err_private_ivar_access)
1426 << IV->getDeclName();
1427 } else if (!IDecl->isSuperClassOf(ClassOfMethodDecl))
1428 // @protected
1429 S.Diag(MemberLoc, diag::err_protected_ivar_access)
1430 << IV->getDeclName();
1431 }
1432 }
1433 bool warn = true;
1434 if (S.getLangOpts().ObjCWeak) {
1435 Expr *BaseExp = BaseExpr.get()->IgnoreParenImpCasts();
1436 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(BaseExp))
1437 if (UO->getOpcode() == UO_Deref)
1438 BaseExp = UO->getSubExpr()->IgnoreParenCasts();
1439
1440 if (DeclRefExpr *DE = dyn_cast<DeclRefExpr>(BaseExp))
1441 if (DE->getType().getObjCLifetime() == Qualifiers::OCL_Weak) {
1442 S.Diag(DE->getLocation(), diag::err_arc_weak_ivar_access);
1443 warn = false;
1444 }
1445 }
1446 if (warn) {
1447 if (ObjCMethodDecl *MD = S.getCurMethodDecl()) {
1448 ObjCMethodFamily MF = MD->getMethodFamily();
1449 warn = (MF != OMF_init && MF != OMF_dealloc &&
1450 MF != OMF_finalize &&
1451 !S.IvarBacksCurrentMethodAccessor(IDecl, MD, IV));
1452 }
1453 if (warn)
1454 S.Diag(MemberLoc, diag::warn_direct_ivar_access) << IV->getDeclName();
1455 }
1456
1457 ObjCIvarRefExpr *Result = new (S.Context) ObjCIvarRefExpr(
1458 IV, IV->getUsageType(BaseType), MemberLoc, OpLoc, BaseExpr.get(),
1459 IsArrow);
1460
1461 if (IV->getType().getObjCLifetime() == Qualifiers::OCL_Weak) {
1462 if (!S.isUnevaluatedContext() &&
1463 !S.Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, MemberLoc))
1464 S.getCurFunction()->recordUseOfWeak(Result);
1465 }
1466
1467 return Result;
1468 }
1469
1470 // Objective-C property access.
1471 const ObjCObjectPointerType *OPT;
1472 if (!IsArrow
7.1
'IsArrow' is false
&& (OPT = BaseType->getAs<ObjCObjectPointerType>())) {
8
Assuming the object is not a 'ObjCObjectPointerType'
9
Assuming 'OPT' is null
10
Taking false branch
1473 if (!SS.isEmpty() && !SS.isInvalid()) {
1474 S.Diag(SS.getRange().getBegin(), diag::err_qualified_objc_access)
1475 << 0 << SS.getScopeRep() << FixItHint::CreateRemoval(SS.getRange());
1476 SS.clear();
1477 }
1478
1479 // This actually uses the base as an r-value.
1480 BaseExpr = S.DefaultLvalueConversion(BaseExpr.get());
1481 if (BaseExpr.isInvalid())
1482 return ExprError();
1483
1484 assert(S.Context.hasSameUnqualifiedType(BaseType,((void)0)
1485 BaseExpr.get()->getType()))((void)0);
1486
1487 IdentifierInfo *Member = MemberName.getAsIdentifierInfo();
1488
1489 const ObjCObjectType *OT = OPT->getObjectType();
1490
1491 // id, with and without qualifiers.
1492 if (OT->isObjCId()) {
1493 // Check protocols on qualified interfaces.
1494 Selector Sel = S.PP.getSelectorTable().getNullarySelector(Member);
1495 if (Decl *PMDecl =
1496 FindGetterSetterNameDecl(OPT, Member, Sel, S.Context)) {
1497 if (ObjCPropertyDecl *PD = dyn_cast<ObjCPropertyDecl>(PMDecl)) {
1498 // Check the use of this declaration
1499 if (S.DiagnoseUseOfDecl(PD, MemberLoc))
1500 return ExprError();
1501
1502 return new (S.Context)
1503 ObjCPropertyRefExpr(PD, S.Context.PseudoObjectTy, VK_LValue,
1504 OK_ObjCProperty, MemberLoc, BaseExpr.get());
1505 }
1506
1507 if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(PMDecl)) {
1508 Selector SetterSel =
1509 SelectorTable::constructSetterSelector(S.PP.getIdentifierTable(),
1510 S.PP.getSelectorTable(),
1511 Member);
1512 ObjCMethodDecl *SMD = nullptr;
1513 if (Decl *SDecl = FindGetterSetterNameDecl(OPT,
1514 /*Property id*/ nullptr,
1515 SetterSel, S.Context))
1516 SMD = dyn_cast<ObjCMethodDecl>(SDecl);
1517
1518 return new (S.Context)
1519 ObjCPropertyRefExpr(OMD, SMD, S.Context.PseudoObjectTy, VK_LValue,
1520 OK_ObjCProperty, MemberLoc, BaseExpr.get());
1521 }
1522 }
1523 // Use of id.member can only be for a property reference. Do not
1524 // use the 'id' redefinition in this case.
1525 if (IsArrow && ShouldTryAgainWithRedefinitionType(S, BaseExpr))
1526 return LookupMemberExpr(S, R, BaseExpr, IsArrow, OpLoc, SS,
1527 ObjCImpDecl, HasTemplateArgs, TemplateKWLoc);
1528
1529 return ExprError(S.Diag(MemberLoc, diag::err_property_not_found)
1530 << MemberName << BaseType);
1531 }
1532
1533 // 'Class', unqualified only.
1534 if (OT->isObjCClass()) {
1535 // Only works in a method declaration (??!).
1536 ObjCMethodDecl *MD = S.getCurMethodDecl();
1537 if (!MD) {
1538 if (ShouldTryAgainWithRedefinitionType(S, BaseExpr))
1539 return LookupMemberExpr(S, R, BaseExpr, IsArrow, OpLoc, SS,
1540 ObjCImpDecl, HasTemplateArgs, TemplateKWLoc);
1541
1542 goto fail;
1543 }
1544
1545 // Also must look for a getter name which uses property syntax.
1546 Selector Sel = S.PP.getSelectorTable().getNullarySelector(Member);
1547 ObjCInterfaceDecl *IFace = MD->getClassInterface();
1548 if (!IFace)
1549 goto fail;
1550
1551 ObjCMethodDecl *Getter;
1552 if ((Getter = IFace->lookupClassMethod(Sel))) {
1553 // Check the use of this method.
1554 if (S.DiagnoseUseOfDecl(Getter, MemberLoc))
1555 return ExprError();
1556 } else
1557 Getter = IFace->lookupPrivateMethod(Sel, false);
1558 // If we found a getter then this may be a valid dot-reference, we
1559 // will look for the matching setter, in case it is needed.
1560 Selector SetterSel =
1561 SelectorTable::constructSetterSelector(S.PP.getIdentifierTable(),
1562 S.PP.getSelectorTable(),
1563 Member);
1564 ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel);
1565 if (!Setter) {
1566 // If this reference is in an @implementation, also check for 'private'
1567 // methods.
1568 Setter = IFace->lookupPrivateMethod(SetterSel, false);
1569 }
1570
1571 if (Setter && S.DiagnoseUseOfDecl(Setter, MemberLoc))
1572 return ExprError();
1573
1574 if (Getter || Setter) {
1575 return new (S.Context) ObjCPropertyRefExpr(
1576 Getter, Setter, S.Context.PseudoObjectTy, VK_LValue,
1577 OK_ObjCProperty, MemberLoc, BaseExpr.get());
1578 }
1579
1580 if (ShouldTryAgainWithRedefinitionType(S, BaseExpr))
1581 return LookupMemberExpr(S, R, BaseExpr, IsArrow, OpLoc, SS,
1582 ObjCImpDecl, HasTemplateArgs, TemplateKWLoc);
1583
1584 return ExprError(S.Diag(MemberLoc, diag::err_property_not_found)
1585 << MemberName << BaseType);
1586 }
1587
1588 // Normal property access.
1589 return S.HandleExprPropertyRefExpr(OPT, BaseExpr.get(), OpLoc, MemberName,
1590 MemberLoc, SourceLocation(), QualType(),
1591 false);
1592 }
1593
1594 // Handle 'field access' to vectors, such as 'V.xx'.
1595 if (BaseType->isExtVectorType()) {
11
Taking true branch
1596 // FIXME: this expr should store IsArrow.
1597 IdentifierInfo *Member = MemberName.getAsIdentifierInfo();
1598 ExprValueKind VK;
1599 if (IsArrow
11.1
'IsArrow' is false
)
12
Taking false branch
1600 VK = VK_LValue;
1601 else {
1602 if (PseudoObjectExpr *POE
13.1
'POE' is non-null
= dyn_cast<PseudoObjectExpr>(BaseExpr.get()))
13
Assuming the object is a 'PseudoObjectExpr'
14
Taking true branch
1603 VK = POE->getSyntacticForm()->getValueKind();
1604 else
1605 VK = BaseExpr.get()->getValueKind();
1606 }
1607
1608 QualType ret = CheckExtVectorComponent(S, BaseType, VK, OpLoc,
15
Calling 'CheckExtVectorComponent'
1609 Member, MemberLoc);
1610 if (ret.isNull())
1611 return ExprError();
1612 Qualifiers BaseQ =
1613 S.Context.getCanonicalType(BaseExpr.get()->getType()).getQualifiers();
1614 ret = S.Context.getQualifiedType(ret, BaseQ);
1615
1616 return new (S.Context)
1617 ExtVectorElementExpr(ret, VK, BaseExpr.get(), *Member, MemberLoc);
1618 }
1619
1620 // Adjust builtin-sel to the appropriate redefinition type if that's
1621 // not just a pointer to builtin-sel again.
1622 if (IsArrow && BaseType->isSpecificBuiltinType(BuiltinType::ObjCSel) &&
1623 !S.Context.getObjCSelRedefinitionType()->isObjCSelType()) {
1624 BaseExpr = S.ImpCastExprToType(
1625 BaseExpr.get(), S.Context.getObjCSelRedefinitionType(), CK_BitCast);
1626 return LookupMemberExpr(S, R, BaseExpr, IsArrow, OpLoc, SS,
1627 ObjCImpDecl, HasTemplateArgs, TemplateKWLoc);
1628 }
1629
1630 // Failure cases.
1631 fail:
1632
1633 // Recover from dot accesses to pointers, e.g.:
1634 // type *foo;
1635 // foo.bar
1636 // This is actually well-formed in two cases:
1637 // - 'type' is an Objective C type
1638 // - 'bar' is a pseudo-destructor name which happens to refer to
1639 // the appropriate pointer type
1640 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
1641 if (!IsArrow && Ptr->getPointeeType()->isRecordType() &&
1642 MemberName.getNameKind() != DeclarationName::CXXDestructorName) {
1643 S.Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
1644 << BaseType << int(IsArrow) << BaseExpr.get()->getSourceRange()
1645 << FixItHint::CreateReplacement(OpLoc, "->");
1646
1647 // Recurse as an -> access.
1648 IsArrow = true;
1649 return LookupMemberExpr(S, R, BaseExpr, IsArrow, OpLoc, SS,
1650 ObjCImpDecl, HasTemplateArgs, TemplateKWLoc);
1651 }
1652 }
1653
1654 // If the user is trying to apply -> or . to a function name, it's probably
1655 // because they forgot parentheses to call that function.
1656 if (S.tryToRecoverWithCall(
1657 BaseExpr, S.PDiag(diag::err_member_reference_needs_call),
1658 /*complain*/ false,
1659 IsArrow ? &isPointerToRecordType : &isRecordType)) {
1660 if (BaseExpr.isInvalid())
1661 return ExprError();
1662 BaseExpr = S.DefaultFunctionArrayConversion(BaseExpr.get());
1663 return LookupMemberExpr(S, R, BaseExpr, IsArrow, OpLoc, SS,
1664 ObjCImpDecl, HasTemplateArgs, TemplateKWLoc);
1665 }
1666
1667 S.Diag(OpLoc, diag::err_typecheck_member_reference_struct_union)
1668 << BaseType << BaseExpr.get()->getSourceRange() << MemberLoc;
1669
1670 return ExprError();
1671}
1672
1673/// The main callback when the parser finds something like
1674/// expression . [nested-name-specifier] identifier
1675/// expression -> [nested-name-specifier] identifier
1676/// where 'identifier' encompasses a fairly broad spectrum of
1677/// possibilities, including destructor and operator references.
1678///
1679/// \param OpKind either tok::arrow or tok::period
1680/// \param ObjCImpDecl the current Objective-C \@implementation
1681/// decl; this is an ugly hack around the fact that Objective-C
1682/// \@implementations aren't properly put in the context chain
1683ExprResult Sema::ActOnMemberAccessExpr(Scope *S, Expr *Base,
1684 SourceLocation OpLoc,
1685 tok::TokenKind OpKind,
1686 CXXScopeSpec &SS,
1687 SourceLocation TemplateKWLoc,
1688 UnqualifiedId &Id,
1689 Decl *ObjCImpDecl) {
1690 if (SS.isSet() && SS.isInvalid())
1691 return ExprError();
1692
1693 // Warn about the explicit constructor calls Microsoft extension.
1694 if (getLangOpts().MicrosoftExt &&
1695 Id.getKind() == UnqualifiedIdKind::IK_ConstructorName)
1696 Diag(Id.getSourceRange().getBegin(),
1697 diag::ext_ms_explicit_constructor_call);
1698
1699 TemplateArgumentListInfo TemplateArgsBuffer;
1700
1701 // Decompose the name into its component parts.
1702 DeclarationNameInfo NameInfo;
1703 const TemplateArgumentListInfo *TemplateArgs;
1704 DecomposeUnqualifiedId(Id, TemplateArgsBuffer,
1705 NameInfo, TemplateArgs);
1706
1707 DeclarationName Name = NameInfo.getName();
1708 bool IsArrow = (OpKind == tok::arrow);
1709
1710 NamedDecl *FirstQualifierInScope
1711 = (!SS.isSet() ? nullptr : FindFirstQualifierInScope(S, SS.getScopeRep()));
1712
1713 // This is a postfix expression, so get rid of ParenListExprs.
1714 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base);
1715 if (Result.isInvalid()) return ExprError();
1716 Base = Result.get();
1717
1718 if (Base->getType()->isDependentType() || Name.isDependentName() ||
1719 isDependentScopeSpecifier(SS)) {
1720 return ActOnDependentMemberExpr(Base, Base->getType(), IsArrow, OpLoc, SS,
1721 TemplateKWLoc, FirstQualifierInScope,
1722 NameInfo, TemplateArgs);
1723 }
1724
1725 ActOnMemberAccessExtraArgs ExtraArgs = {S, Id, ObjCImpDecl};
1726 ExprResult Res = BuildMemberReferenceExpr(
1727 Base, Base->getType(), OpLoc, IsArrow, SS, TemplateKWLoc,
1728 FirstQualifierInScope, NameInfo, TemplateArgs, S, &ExtraArgs);
1729
1730 if (!Res.isInvalid() && isa<MemberExpr>(Res.get()))
1731 CheckMemberAccessOfNoDeref(cast<MemberExpr>(Res.get()));
1732
1733 return Res;
1734}
1735
1736void Sema::CheckMemberAccessOfNoDeref(const MemberExpr *E) {
1737 if (isUnevaluatedContext())
1738 return;
1739
1740 QualType ResultTy = E->getType();
1741
1742 // Member accesses have four cases:
1743 // 1: non-array member via "->": dereferences
1744 // 2: non-array member via ".": nothing interesting happens
1745 // 3: array member access via "->": nothing interesting happens
1746 // (this returns an array lvalue and does not actually dereference memory)
1747 // 4: array member access via ".": *adds* a layer of indirection
1748 if (ResultTy->isArrayType()) {
1749 if (!E->isArrow()) {
1750 // This might be something like:
1751 // (*structPtr).arrayMember
1752 // which behaves roughly like:
1753 // &(*structPtr).pointerMember
1754 // in that the apparent dereference in the base expression does not
1755 // actually happen.
1756 CheckAddressOfNoDeref(E->getBase());
1757 }
1758 } else if (E->isArrow()) {
1759 if (const auto *Ptr = dyn_cast<PointerType>(
1760 E->getBase()->getType().getDesugaredType(Context))) {
1761 if (Ptr->getPointeeType()->hasAttr(attr::NoDeref))
1762 ExprEvalContexts.back().PossibleDerefs.insert(E);
1763 }
1764 }
1765}
1766
1767ExprResult
1768Sema::BuildFieldReferenceExpr(Expr *BaseExpr, bool IsArrow,
1769 SourceLocation OpLoc, const CXXScopeSpec &SS,
1770 FieldDecl *Field, DeclAccessPair FoundDecl,
1771 const DeclarationNameInfo &MemberNameInfo) {
1772 // x.a is an l-value if 'a' has a reference type. Otherwise:
1773 // x.a is an l-value/x-value/pr-value if the base is (and note
1774 // that *x is always an l-value), except that if the base isn't
1775 // an ordinary object then we must have an rvalue.
1776 ExprValueKind VK = VK_LValue;
1777 ExprObjectKind OK = OK_Ordinary;
1778 if (!IsArrow) {
1779 if (BaseExpr->getObjectKind() == OK_Ordinary)
1780 VK = BaseExpr->getValueKind();
1781 else
1782 VK = VK_PRValue;
1783 }
1784 if (VK != VK_PRValue && Field->isBitField())
1785 OK = OK_BitField;
1786
1787 // Figure out the type of the member; see C99 6.5.2.3p3, C++ [expr.ref]
1788 QualType MemberType = Field->getType();
1789 if (const ReferenceType *Ref = MemberType->getAs<ReferenceType>()) {
1790 MemberType = Ref->getPointeeType();
1791 VK = VK_LValue;
1792 } else {
1793 QualType BaseType = BaseExpr->getType();
1794 if (IsArrow) BaseType = BaseType->castAs<PointerType>()->getPointeeType();
1795
1796 Qualifiers BaseQuals = BaseType.getQualifiers();
1797
1798 // GC attributes are never picked up by members.
1799 BaseQuals.removeObjCGCAttr();
1800
1801 // CVR attributes from the base are picked up by members,
1802 // except that 'mutable' members don't pick up 'const'.
1803 if (Field->isMutable()) BaseQuals.removeConst();
1804
1805 Qualifiers MemberQuals =
1806 Context.getCanonicalType(MemberType).getQualifiers();
1807
1808 assert(!MemberQuals.hasAddressSpace())((void)0);
1809
1810 Qualifiers Combined = BaseQuals + MemberQuals;
1811 if (Combined != MemberQuals)
1812 MemberType = Context.getQualifiedType(MemberType, Combined);
1813
1814 // Pick up NoDeref from the base in case we end up using AddrOf on the
1815 // result. E.g. the expression
1816 // &someNoDerefPtr->pointerMember
1817 // should be a noderef pointer again.
1818 if (BaseType->hasAttr(attr::NoDeref))
1819 MemberType =
1820 Context.getAttributedType(attr::NoDeref, MemberType, MemberType);
1821 }
1822
1823 auto *CurMethod = dyn_cast<CXXMethodDecl>(CurContext);
1824 if (!(CurMethod && CurMethod->isDefaulted()))
1825 UnusedPrivateFields.remove(Field);
1826
1827 ExprResult Base = PerformObjectMemberConversion(BaseExpr, SS.getScopeRep(),
1828 FoundDecl, Field);
1829 if (Base.isInvalid())
1830 return ExprError();
1831
1832 // Build a reference to a private copy for non-static data members in
1833 // non-static member functions, privatized by OpenMP constructs.
1834 if (getLangOpts().OpenMP && IsArrow &&
1835 !CurContext->isDependentContext() &&
1836 isa<CXXThisExpr>(Base.get()->IgnoreParenImpCasts())) {
1837 if (auto *PrivateCopy = isOpenMPCapturedDecl(Field)) {
1838 return getOpenMPCapturedExpr(PrivateCopy, VK, OK,
1839 MemberNameInfo.getLoc());
1840 }
1841 }
1842
1843 return BuildMemberExpr(Base.get(), IsArrow, OpLoc, &SS,
1844 /*TemplateKWLoc=*/SourceLocation(), Field, FoundDecl,
1845 /*HadMultipleCandidates=*/false, MemberNameInfo,
1846 MemberType, VK, OK);
1847}
1848
1849/// Builds an implicit member access expression. The current context
1850/// is known to be an instance method, and the given unqualified lookup
1851/// set is known to contain only instance members, at least one of which
1852/// is from an appropriate type.
1853ExprResult
1854Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS,
1855 SourceLocation TemplateKWLoc,
1856 LookupResult &R,
1857 const TemplateArgumentListInfo *TemplateArgs,
1858 bool IsKnownInstance, const Scope *S) {
1859 assert(!R.empty() && !R.isAmbiguous())((void)0);
1860
1861 SourceLocation loc = R.getNameLoc();
1862
1863 // If this is known to be an instance access, go ahead and build an
1864 // implicit 'this' expression now.
1865 QualType ThisTy = getCurrentThisType();
1866 assert(!ThisTy.isNull() && "didn't correctly pre-flight capture of 'this'")((void)0);
1867
1868 Expr *baseExpr = nullptr; // null signifies implicit access
1869 if (IsKnownInstance) {
1870 SourceLocation Loc = R.getNameLoc();
1871 if (SS.getRange().isValid())
1872 Loc = SS.getRange().getBegin();
1873 baseExpr = BuildCXXThisExpr(loc, ThisTy, /*IsImplicit=*/true);
1874 }
1875
1876 return BuildMemberReferenceExpr(baseExpr, ThisTy,
1877 /*OpLoc*/ SourceLocation(),
1878 /*IsArrow*/ true,
1879 SS, TemplateKWLoc,
1880 /*FirstQualifierInScope*/ nullptr,
1881 R, TemplateArgs, S);
1882}