Bug Summary

File:clang/lib/Sema/SemaDecl.cpp
Warning:line 14309, column 29
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SemaDecl.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 -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -fhalf-no-semantic-interposition -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -fno-split-dwarf-inlining -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-13/lib/clang/13.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema -I /build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/include -I /build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/build-llvm/include -I /build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-13/lib/clang/13.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/build-llvm/tools/clang/lib/Sema -fdebug-prefix-map=/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2021-02-23-121308-24221-1 -x c++ /build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp
1//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements semantic analysis for declarations.
10//
11//===----------------------------------------------------------------------===//
12
13#include "TypeLocBuilder.h"
14#include "clang/AST/ASTConsumer.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/ASTLambda.h"
17#include "clang/AST/CXXInheritance.h"
18#include "clang/AST/CharUnits.h"
19#include "clang/AST/CommentDiagnostic.h"
20#include "clang/AST/DeclCXX.h"
21#include "clang/AST/DeclObjC.h"
22#include "clang/AST/DeclTemplate.h"
23#include "clang/AST/EvaluatedExprVisitor.h"
24#include "clang/AST/Expr.h"
25#include "clang/AST/ExprCXX.h"
26#include "clang/AST/NonTrivialTypeVisitor.h"
27#include "clang/AST/StmtCXX.h"
28#include "clang/Basic/Builtins.h"
29#include "clang/Basic/PartialDiagnostic.h"
30#include "clang/Basic/SourceManager.h"
31#include "clang/Basic/TargetInfo.h"
32#include "clang/Lex/HeaderSearch.h" // TODO: Sema shouldn't depend on Lex
33#include "clang/Lex/Lexer.h" // TODO: Extract static functions to fix layering.
34#include "clang/Lex/ModuleLoader.h" // TODO: Sema shouldn't depend on Lex
35#include "clang/Lex/Preprocessor.h" // Included for isCodeCompletionEnabled()
36#include "clang/Sema/CXXFieldCollector.h"
37#include "clang/Sema/DeclSpec.h"
38#include "clang/Sema/DelayedDiagnostic.h"
39#include "clang/Sema/Initialization.h"
40#include "clang/Sema/Lookup.h"
41#include "clang/Sema/ParsedTemplate.h"
42#include "clang/Sema/Scope.h"
43#include "clang/Sema/ScopeInfo.h"
44#include "clang/Sema/SemaInternal.h"
45#include "clang/Sema/Template.h"
46#include "llvm/ADT/SmallString.h"
47#include "llvm/ADT/Triple.h"
48#include <algorithm>
49#include <cstring>
50#include <functional>
51#include <unordered_map>
52
53using namespace clang;
54using namespace sema;
55
56Sema::DeclGroupPtrTy Sema::ConvertDeclToDeclGroup(Decl *Ptr, Decl *OwnedType) {
57 if (OwnedType) {
58 Decl *Group[2] = { OwnedType, Ptr };
59 return DeclGroupPtrTy::make(DeclGroupRef::Create(Context, Group, 2));
60 }
61
62 return DeclGroupPtrTy::make(DeclGroupRef(Ptr));
63}
64
65namespace {
66
67class TypeNameValidatorCCC final : public CorrectionCandidateCallback {
68 public:
69 TypeNameValidatorCCC(bool AllowInvalid, bool WantClass = false,
70 bool AllowTemplates = false,
71 bool AllowNonTemplates = true)
72 : AllowInvalidDecl(AllowInvalid), WantClassName(WantClass),
73 AllowTemplates(AllowTemplates), AllowNonTemplates(AllowNonTemplates) {
74 WantExpressionKeywords = false;
75 WantCXXNamedCasts = false;
76 WantRemainingKeywords = false;
77 }
78
79 bool ValidateCandidate(const TypoCorrection &candidate) override {
80 if (NamedDecl *ND = candidate.getCorrectionDecl()) {
81 if (!AllowInvalidDecl && ND->isInvalidDecl())
82 return false;
83
84 if (getAsTypeTemplateDecl(ND))
85 return AllowTemplates;
86
87 bool IsType = isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND);
88 if (!IsType)
89 return false;
90
91 if (AllowNonTemplates)
92 return true;
93
94 // An injected-class-name of a class template (specialization) is valid
95 // as a template or as a non-template.
96 if (AllowTemplates) {
97 auto *RD = dyn_cast<CXXRecordDecl>(ND);
98 if (!RD || !RD->isInjectedClassName())
99 return false;
100 RD = cast<CXXRecordDecl>(RD->getDeclContext());
101 return RD->getDescribedClassTemplate() ||
102 isa<ClassTemplateSpecializationDecl>(RD);
103 }
104
105 return false;
106 }
107
108 return !WantClassName && candidate.isKeyword();
109 }
110
111 std::unique_ptr<CorrectionCandidateCallback> clone() override {
112 return std::make_unique<TypeNameValidatorCCC>(*this);
113 }
114
115 private:
116 bool AllowInvalidDecl;
117 bool WantClassName;
118 bool AllowTemplates;
119 bool AllowNonTemplates;
120};
121
122} // end anonymous namespace
123
124/// Determine whether the token kind starts a simple-type-specifier.
125bool Sema::isSimpleTypeSpecifier(tok::TokenKind Kind) const {
126 switch (Kind) {
127 // FIXME: Take into account the current language when deciding whether a
128 // token kind is a valid type specifier
129 case tok::kw_short:
130 case tok::kw_long:
131 case tok::kw___int64:
132 case tok::kw___int128:
133 case tok::kw_signed:
134 case tok::kw_unsigned:
135 case tok::kw_void:
136 case tok::kw_char:
137 case tok::kw_int:
138 case tok::kw_half:
139 case tok::kw_float:
140 case tok::kw_double:
141 case tok::kw___bf16:
142 case tok::kw__Float16:
143 case tok::kw___float128:
144 case tok::kw_wchar_t:
145 case tok::kw_bool:
146 case tok::kw___underlying_type:
147 case tok::kw___auto_type:
148 return true;
149
150 case tok::annot_typename:
151 case tok::kw_char16_t:
152 case tok::kw_char32_t:
153 case tok::kw_typeof:
154 case tok::annot_decltype:
155 case tok::kw_decltype:
156 return getLangOpts().CPlusPlus;
157
158 case tok::kw_char8_t:
159 return getLangOpts().Char8;
160
161 default:
162 break;
163 }
164
165 return false;
166}
167
168namespace {
169enum class UnqualifiedTypeNameLookupResult {
170 NotFound,
171 FoundNonType,
172 FoundType
173};
174} // end anonymous namespace
175
176/// Tries to perform unqualified lookup of the type decls in bases for
177/// dependent class.
178/// \return \a NotFound if no any decls is found, \a FoundNotType if found not a
179/// type decl, \a FoundType if only type decls are found.
180static UnqualifiedTypeNameLookupResult
181lookupUnqualifiedTypeNameInBase(Sema &S, const IdentifierInfo &II,
182 SourceLocation NameLoc,
183 const CXXRecordDecl *RD) {
184 if (!RD->hasDefinition())
185 return UnqualifiedTypeNameLookupResult::NotFound;
186 // Look for type decls in base classes.
187 UnqualifiedTypeNameLookupResult FoundTypeDecl =
188 UnqualifiedTypeNameLookupResult::NotFound;
189 for (const auto &Base : RD->bases()) {
190 const CXXRecordDecl *BaseRD = nullptr;
191 if (auto *BaseTT = Base.getType()->getAs<TagType>())
192 BaseRD = BaseTT->getAsCXXRecordDecl();
193 else if (auto *TST = Base.getType()->getAs<TemplateSpecializationType>()) {
194 // Look for type decls in dependent base classes that have known primary
195 // templates.
196 if (!TST || !TST->isDependentType())
197 continue;
198 auto *TD = TST->getTemplateName().getAsTemplateDecl();
199 if (!TD)
200 continue;
201 if (auto *BasePrimaryTemplate =
202 dyn_cast_or_null<CXXRecordDecl>(TD->getTemplatedDecl())) {
203 if (BasePrimaryTemplate->getCanonicalDecl() != RD->getCanonicalDecl())
204 BaseRD = BasePrimaryTemplate;
205 else if (auto *CTD = dyn_cast<ClassTemplateDecl>(TD)) {
206 if (const ClassTemplatePartialSpecializationDecl *PS =
207 CTD->findPartialSpecialization(Base.getType()))
208 if (PS->getCanonicalDecl() != RD->getCanonicalDecl())
209 BaseRD = PS;
210 }
211 }
212 }
213 if (BaseRD) {
214 for (NamedDecl *ND : BaseRD->lookup(&II)) {
215 if (!isa<TypeDecl>(ND))
216 return UnqualifiedTypeNameLookupResult::FoundNonType;
217 FoundTypeDecl = UnqualifiedTypeNameLookupResult::FoundType;
218 }
219 if (FoundTypeDecl == UnqualifiedTypeNameLookupResult::NotFound) {
220 switch (lookupUnqualifiedTypeNameInBase(S, II, NameLoc, BaseRD)) {
221 case UnqualifiedTypeNameLookupResult::FoundNonType:
222 return UnqualifiedTypeNameLookupResult::FoundNonType;
223 case UnqualifiedTypeNameLookupResult::FoundType:
224 FoundTypeDecl = UnqualifiedTypeNameLookupResult::FoundType;
225 break;
226 case UnqualifiedTypeNameLookupResult::NotFound:
227 break;
228 }
229 }
230 }
231 }
232
233 return FoundTypeDecl;
234}
235
236static ParsedType recoverFromTypeInKnownDependentBase(Sema &S,
237 const IdentifierInfo &II,
238 SourceLocation NameLoc) {
239 // Lookup in the parent class template context, if any.
240 const CXXRecordDecl *RD = nullptr;
241 UnqualifiedTypeNameLookupResult FoundTypeDecl =
242 UnqualifiedTypeNameLookupResult::NotFound;
243 for (DeclContext *DC = S.CurContext;
244 DC && FoundTypeDecl == UnqualifiedTypeNameLookupResult::NotFound;
245 DC = DC->getParent()) {
246 // Look for type decls in dependent base classes that have known primary
247 // templates.
248 RD = dyn_cast<CXXRecordDecl>(DC);
249 if (RD && RD->getDescribedClassTemplate())
250 FoundTypeDecl = lookupUnqualifiedTypeNameInBase(S, II, NameLoc, RD);
251 }
252 if (FoundTypeDecl != UnqualifiedTypeNameLookupResult::FoundType)
253 return nullptr;
254
255 // We found some types in dependent base classes. Recover as if the user
256 // wrote 'typename MyClass::II' instead of 'II'. We'll fully resolve the
257 // lookup during template instantiation.
258 S.Diag(NameLoc, diag::ext_found_in_dependent_base) << &II;
259
260 ASTContext &Context = S.Context;
261 auto *NNS = NestedNameSpecifier::Create(Context, nullptr, false,
262 cast<Type>(Context.getRecordType(RD)));
263 QualType T = Context.getDependentNameType(ETK_Typename, NNS, &II);
264
265 CXXScopeSpec SS;
266 SS.MakeTrivial(Context, NNS, SourceRange(NameLoc));
267
268 TypeLocBuilder Builder;
269 DependentNameTypeLoc DepTL = Builder.push<DependentNameTypeLoc>(T);
270 DepTL.setNameLoc(NameLoc);
271 DepTL.setElaboratedKeywordLoc(SourceLocation());
272 DepTL.setQualifierLoc(SS.getWithLocInContext(Context));
273 return S.CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
274}
275
276/// If the identifier refers to a type name within this scope,
277/// return the declaration of that type.
278///
279/// This routine performs ordinary name lookup of the identifier II
280/// within the given scope, with optional C++ scope specifier SS, to
281/// determine whether the name refers to a type. If so, returns an
282/// opaque pointer (actually a QualType) corresponding to that
283/// type. Otherwise, returns NULL.
284ParsedType Sema::getTypeName(const IdentifierInfo &II, SourceLocation NameLoc,
285 Scope *S, CXXScopeSpec *SS,
286 bool isClassName, bool HasTrailingDot,
287 ParsedType ObjectTypePtr,
288 bool IsCtorOrDtorName,
289 bool WantNontrivialTypeSourceInfo,
290 bool IsClassTemplateDeductionContext,
291 IdentifierInfo **CorrectedII) {
292 // FIXME: Consider allowing this outside C++1z mode as an extension.
293 bool AllowDeducedTemplate = IsClassTemplateDeductionContext &&
294 getLangOpts().CPlusPlus17 && !IsCtorOrDtorName &&
295 !isClassName && !HasTrailingDot;
296
297 // Determine where we will perform name lookup.
298 DeclContext *LookupCtx = nullptr;
299 if (ObjectTypePtr) {
300 QualType ObjectType = ObjectTypePtr.get();
301 if (ObjectType->isRecordType())
302 LookupCtx = computeDeclContext(ObjectType);
303 } else if (SS && SS->isNotEmpty()) {
304 LookupCtx = computeDeclContext(*SS, false);
305
306 if (!LookupCtx) {
307 if (isDependentScopeSpecifier(*SS)) {
308 // C++ [temp.res]p3:
309 // A qualified-id that refers to a type and in which the
310 // nested-name-specifier depends on a template-parameter (14.6.2)
311 // shall be prefixed by the keyword typename to indicate that the
312 // qualified-id denotes a type, forming an
313 // elaborated-type-specifier (7.1.5.3).
314 //
315 // We therefore do not perform any name lookup if the result would
316 // refer to a member of an unknown specialization.
317 if (!isClassName && !IsCtorOrDtorName)
318 return nullptr;
319
320 // We know from the grammar that this name refers to a type,
321 // so build a dependent node to describe the type.
322 if (WantNontrivialTypeSourceInfo)
323 return ActOnTypenameType(S, SourceLocation(), *SS, II, NameLoc).get();
324
325 NestedNameSpecifierLoc QualifierLoc = SS->getWithLocInContext(Context);
326 QualType T = CheckTypenameType(ETK_None, SourceLocation(), QualifierLoc,
327 II, NameLoc);
328 return ParsedType::make(T);
329 }
330
331 return nullptr;
332 }
333
334 if (!LookupCtx->isDependentContext() &&
335 RequireCompleteDeclContext(*SS, LookupCtx))
336 return nullptr;
337 }
338
339 // FIXME: LookupNestedNameSpecifierName isn't the right kind of
340 // lookup for class-names.
341 LookupNameKind Kind = isClassName ? LookupNestedNameSpecifierName :
342 LookupOrdinaryName;
343 LookupResult Result(*this, &II, NameLoc, Kind);
344 if (LookupCtx) {
345 // Perform "qualified" name lookup into the declaration context we
346 // computed, which is either the type of the base of a member access
347 // expression or the declaration context associated with a prior
348 // nested-name-specifier.
349 LookupQualifiedName(Result, LookupCtx);
350
351 if (ObjectTypePtr && Result.empty()) {
352 // C++ [basic.lookup.classref]p3:
353 // If the unqualified-id is ~type-name, the type-name is looked up
354 // in the context of the entire postfix-expression. If the type T of
355 // the object expression is of a class type C, the type-name is also
356 // looked up in the scope of class C. At least one of the lookups shall
357 // find a name that refers to (possibly cv-qualified) T.
358 LookupName(Result, S);
359 }
360 } else {
361 // Perform unqualified name lookup.
362 LookupName(Result, S);
363
364 // For unqualified lookup in a class template in MSVC mode, look into
365 // dependent base classes where the primary class template is known.
366 if (Result.empty() && getLangOpts().MSVCCompat && (!SS || SS->isEmpty())) {
367 if (ParsedType TypeInBase =
368 recoverFromTypeInKnownDependentBase(*this, II, NameLoc))
369 return TypeInBase;
370 }
371 }
372
373 NamedDecl *IIDecl = nullptr;
374 switch (Result.getResultKind()) {
375 case LookupResult::NotFound:
376 case LookupResult::NotFoundInCurrentInstantiation:
377 if (CorrectedII) {
378 TypeNameValidatorCCC CCC(/*AllowInvalid=*/true, isClassName,
379 AllowDeducedTemplate);
380 TypoCorrection Correction = CorrectTypo(Result.getLookupNameInfo(), Kind,
381 S, SS, CCC, CTK_ErrorRecovery);
382 IdentifierInfo *NewII = Correction.getCorrectionAsIdentifierInfo();
383 TemplateTy Template;
384 bool MemberOfUnknownSpecialization;
385 UnqualifiedId TemplateName;
386 TemplateName.setIdentifier(NewII, NameLoc);
387 NestedNameSpecifier *NNS = Correction.getCorrectionSpecifier();
388 CXXScopeSpec NewSS, *NewSSPtr = SS;
389 if (SS && NNS) {
390 NewSS.MakeTrivial(Context, NNS, SourceRange(NameLoc));
391 NewSSPtr = &NewSS;
392 }
393 if (Correction && (NNS || NewII != &II) &&
394 // Ignore a correction to a template type as the to-be-corrected
395 // identifier is not a template (typo correction for template names
396 // is handled elsewhere).
397 !(getLangOpts().CPlusPlus && NewSSPtr &&
398 isTemplateName(S, *NewSSPtr, false, TemplateName, nullptr, false,
399 Template, MemberOfUnknownSpecialization))) {
400 ParsedType Ty = getTypeName(*NewII, NameLoc, S, NewSSPtr,
401 isClassName, HasTrailingDot, ObjectTypePtr,
402 IsCtorOrDtorName,
403 WantNontrivialTypeSourceInfo,
404 IsClassTemplateDeductionContext);
405 if (Ty) {
406 diagnoseTypo(Correction,
407 PDiag(diag::err_unknown_type_or_class_name_suggest)
408 << Result.getLookupName() << isClassName);
409 if (SS && NNS)
410 SS->MakeTrivial(Context, NNS, SourceRange(NameLoc));
411 *CorrectedII = NewII;
412 return Ty;
413 }
414 }
415 }
416 // If typo correction failed or was not performed, fall through
417 LLVM_FALLTHROUGH[[gnu::fallthrough]];
418 case LookupResult::FoundOverloaded:
419 case LookupResult::FoundUnresolvedValue:
420 Result.suppressDiagnostics();
421 return nullptr;
422
423 case LookupResult::Ambiguous:
424 // Recover from type-hiding ambiguities by hiding the type. We'll
425 // do the lookup again when looking for an object, and we can
426 // diagnose the error then. If we don't do this, then the error
427 // about hiding the type will be immediately followed by an error
428 // that only makes sense if the identifier was treated like a type.
429 if (Result.getAmbiguityKind() == LookupResult::AmbiguousTagHiding) {
430 Result.suppressDiagnostics();
431 return nullptr;
432 }
433
434 // Look to see if we have a type anywhere in the list of results.
435 for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end();
436 Res != ResEnd; ++Res) {
437 if (isa<TypeDecl>(*Res) || isa<ObjCInterfaceDecl>(*Res) ||
438 (AllowDeducedTemplate && getAsTypeTemplateDecl(*Res))) {
439 if (!IIDecl || (*Res)->getLocation() < IIDecl->getLocation())
440 IIDecl = *Res;
441 }
442 }
443
444 if (!IIDecl) {
445 // None of the entities we found is a type, so there is no way
446 // to even assume that the result is a type. In this case, don't
447 // complain about the ambiguity. The parser will either try to
448 // perform this lookup again (e.g., as an object name), which
449 // will produce the ambiguity, or will complain that it expected
450 // a type name.
451 Result.suppressDiagnostics();
452 return nullptr;
453 }
454
455 // We found a type within the ambiguous lookup; diagnose the
456 // ambiguity and then return that type. This might be the right
457 // answer, or it might not be, but it suppresses any attempt to
458 // perform the name lookup again.
459 break;
460
461 case LookupResult::Found:
462 IIDecl = Result.getFoundDecl();
463 break;
464 }
465
466 assert(IIDecl && "Didn't find decl")((IIDecl && "Didn't find decl") ? static_cast<void
> (0) : __assert_fail ("IIDecl && \"Didn't find decl\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 466, __PRETTY_FUNCTION__))
;
467
468 QualType T;
469 if (TypeDecl *TD = dyn_cast<TypeDecl>(IIDecl)) {
470 // C++ [class.qual]p2: A lookup that would find the injected-class-name
471 // instead names the constructors of the class, except when naming a class.
472 // This is ill-formed when we're not actually forming a ctor or dtor name.
473 auto *LookupRD = dyn_cast_or_null<CXXRecordDecl>(LookupCtx);
474 auto *FoundRD = dyn_cast<CXXRecordDecl>(TD);
475 if (!isClassName && !IsCtorOrDtorName && LookupRD && FoundRD &&
476 FoundRD->isInjectedClassName() &&
477 declaresSameEntity(LookupRD, cast<Decl>(FoundRD->getParent())))
478 Diag(NameLoc, diag::err_out_of_line_qualified_id_type_names_constructor)
479 << &II << /*Type*/1;
480
481 DiagnoseUseOfDecl(IIDecl, NameLoc);
482
483 T = Context.getTypeDeclType(TD);
484 MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false);
485 } else if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(IIDecl)) {
486 (void)DiagnoseUseOfDecl(IDecl, NameLoc);
487 if (!HasTrailingDot)
488 T = Context.getObjCInterfaceType(IDecl);
489 } else if (AllowDeducedTemplate) {
490 if (auto *TD = getAsTypeTemplateDecl(IIDecl))
491 T = Context.getDeducedTemplateSpecializationType(TemplateName(TD),
492 QualType(), false);
493 }
494
495 if (T.isNull()) {
496 // If it's not plausibly a type, suppress diagnostics.
497 Result.suppressDiagnostics();
498 return nullptr;
499 }
500
501 // NOTE: avoid constructing an ElaboratedType(Loc) if this is a
502 // constructor or destructor name (in such a case, the scope specifier
503 // will be attached to the enclosing Expr or Decl node).
504 if (SS && SS->isNotEmpty() && !IsCtorOrDtorName &&
505 !isa<ObjCInterfaceDecl>(IIDecl)) {
506 if (WantNontrivialTypeSourceInfo) {
507 // Construct a type with type-source information.
508 TypeLocBuilder Builder;
509 Builder.pushTypeSpec(T).setNameLoc(NameLoc);
510
511 T = getElaboratedType(ETK_None, *SS, T);
512 ElaboratedTypeLoc ElabTL = Builder.push<ElaboratedTypeLoc>(T);
513 ElabTL.setElaboratedKeywordLoc(SourceLocation());
514 ElabTL.setQualifierLoc(SS->getWithLocInContext(Context));
515 return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
516 } else {
517 T = getElaboratedType(ETK_None, *SS, T);
518 }
519 }
520
521 return ParsedType::make(T);
522}
523
524// Builds a fake NNS for the given decl context.
525static NestedNameSpecifier *
526synthesizeCurrentNestedNameSpecifier(ASTContext &Context, DeclContext *DC) {
527 for (;; DC = DC->getLookupParent()) {
528 DC = DC->getPrimaryContext();
529 auto *ND = dyn_cast<NamespaceDecl>(DC);
530 if (ND && !ND->isInline() && !ND->isAnonymousNamespace())
531 return NestedNameSpecifier::Create(Context, nullptr, ND);
532 else if (auto *RD = dyn_cast<CXXRecordDecl>(DC))
533 return NestedNameSpecifier::Create(Context, nullptr, RD->isTemplateDecl(),
534 RD->getTypeForDecl());
535 else if (isa<TranslationUnitDecl>(DC))
536 return NestedNameSpecifier::GlobalSpecifier(Context);
537 }
538 llvm_unreachable("something isn't in TU scope?")::llvm::llvm_unreachable_internal("something isn't in TU scope?"
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 538)
;
539}
540
541/// Find the parent class with dependent bases of the innermost enclosing method
542/// context. Do not look for enclosing CXXRecordDecls directly, or we will end
543/// up allowing unqualified dependent type names at class-level, which MSVC
544/// correctly rejects.
545static const CXXRecordDecl *
546findRecordWithDependentBasesOfEnclosingMethod(const DeclContext *DC) {
547 for (; DC && DC->isDependentContext(); DC = DC->getLookupParent()) {
548 DC = DC->getPrimaryContext();
549 if (const auto *MD = dyn_cast<CXXMethodDecl>(DC))
550 if (MD->getParent()->hasAnyDependentBases())
551 return MD->getParent();
552 }
553 return nullptr;
554}
555
556ParsedType Sema::ActOnMSVCUnknownTypeName(const IdentifierInfo &II,
557 SourceLocation NameLoc,
558 bool IsTemplateTypeArg) {
559 assert(getLangOpts().MSVCCompat && "shouldn't be called in non-MSVC mode")((getLangOpts().MSVCCompat && "shouldn't be called in non-MSVC mode"
) ? static_cast<void> (0) : __assert_fail ("getLangOpts().MSVCCompat && \"shouldn't be called in non-MSVC mode\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 559, __PRETTY_FUNCTION__))
;
560
561 NestedNameSpecifier *NNS = nullptr;
562 if (IsTemplateTypeArg && getCurScope()->isTemplateParamScope()) {
563 // If we weren't able to parse a default template argument, delay lookup
564 // until instantiation time by making a non-dependent DependentTypeName. We
565 // pretend we saw a NestedNameSpecifier referring to the current scope, and
566 // lookup is retried.
567 // FIXME: This hurts our diagnostic quality, since we get errors like "no
568 // type named 'Foo' in 'current_namespace'" when the user didn't write any
569 // name specifiers.
570 NNS = synthesizeCurrentNestedNameSpecifier(Context, CurContext);
571 Diag(NameLoc, diag::ext_ms_delayed_template_argument) << &II;
572 } else if (const CXXRecordDecl *RD =
573 findRecordWithDependentBasesOfEnclosingMethod(CurContext)) {
574 // Build a DependentNameType that will perform lookup into RD at
575 // instantiation time.
576 NNS = NestedNameSpecifier::Create(Context, nullptr, RD->isTemplateDecl(),
577 RD->getTypeForDecl());
578
579 // Diagnose that this identifier was undeclared, and retry the lookup during
580 // template instantiation.
581 Diag(NameLoc, diag::ext_undeclared_unqual_id_with_dependent_base) << &II
582 << RD;
583 } else {
584 // This is not a situation that we should recover from.
585 return ParsedType();
586 }
587
588 QualType T = Context.getDependentNameType(ETK_None, NNS, &II);
589
590 // Build type location information. We synthesized the qualifier, so we have
591 // to build a fake NestedNameSpecifierLoc.
592 NestedNameSpecifierLocBuilder NNSLocBuilder;
593 NNSLocBuilder.MakeTrivial(Context, NNS, SourceRange(NameLoc));
594 NestedNameSpecifierLoc QualifierLoc = NNSLocBuilder.getWithLocInContext(Context);
595
596 TypeLocBuilder Builder;
597 DependentNameTypeLoc DepTL = Builder.push<DependentNameTypeLoc>(T);
598 DepTL.setNameLoc(NameLoc);
599 DepTL.setElaboratedKeywordLoc(SourceLocation());
600 DepTL.setQualifierLoc(QualifierLoc);
601 return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
602}
603
604/// isTagName() - This method is called *for error recovery purposes only*
605/// to determine if the specified name is a valid tag name ("struct foo"). If
606/// so, this returns the TST for the tag corresponding to it (TST_enum,
607/// TST_union, TST_struct, TST_interface, TST_class). This is used to diagnose
608/// cases in C where the user forgot to specify the tag.
609DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) {
610 // Do a tag name lookup in this scope.
611 LookupResult R(*this, &II, SourceLocation(), LookupTagName);
612 LookupName(R, S, false);
613 R.suppressDiagnostics();
614 if (R.getResultKind() == LookupResult::Found)
615 if (const TagDecl *TD = R.getAsSingle<TagDecl>()) {
616 switch (TD->getTagKind()) {
617 case TTK_Struct: return DeclSpec::TST_struct;
618 case TTK_Interface: return DeclSpec::TST_interface;
619 case TTK_Union: return DeclSpec::TST_union;
620 case TTK_Class: return DeclSpec::TST_class;
621 case TTK_Enum: return DeclSpec::TST_enum;
622 }
623 }
624
625 return DeclSpec::TST_unspecified;
626}
627
628/// isMicrosoftMissingTypename - In Microsoft mode, within class scope,
629/// if a CXXScopeSpec's type is equal to the type of one of the base classes
630/// then downgrade the missing typename error to a warning.
631/// This is needed for MSVC compatibility; Example:
632/// @code
633/// template<class T> class A {
634/// public:
635/// typedef int TYPE;
636/// };
637/// template<class T> class B : public A<T> {
638/// public:
639/// A<T>::TYPE a; // no typename required because A<T> is a base class.
640/// };
641/// @endcode
642bool Sema::isMicrosoftMissingTypename(const CXXScopeSpec *SS, Scope *S) {
643 if (CurContext->isRecord()) {
644 if (SS->getScopeRep()->getKind() == NestedNameSpecifier::Super)
645 return true;
646
647 const Type *Ty = SS->getScopeRep()->getAsType();
648
649 CXXRecordDecl *RD = cast<CXXRecordDecl>(CurContext);
650 for (const auto &Base : RD->bases())
651 if (Ty && Context.hasSameUnqualifiedType(QualType(Ty, 1), Base.getType()))
652 return true;
653 return S->isFunctionPrototypeScope();
654 }
655 return CurContext->isFunctionOrMethod() || S->isFunctionPrototypeScope();
656}
657
658void Sema::DiagnoseUnknownTypeName(IdentifierInfo *&II,
659 SourceLocation IILoc,
660 Scope *S,
661 CXXScopeSpec *SS,
662 ParsedType &SuggestedType,
663 bool IsTemplateName) {
664 // Don't report typename errors for editor placeholders.
665 if (II->isEditorPlaceholder())
666 return;
667 // We don't have anything to suggest (yet).
668 SuggestedType = nullptr;
669
670 // There may have been a typo in the name of the type. Look up typo
671 // results, in case we have something that we can suggest.
672 TypeNameValidatorCCC CCC(/*AllowInvalid=*/false, /*WantClass=*/false,
673 /*AllowTemplates=*/IsTemplateName,
674 /*AllowNonTemplates=*/!IsTemplateName);
675 if (TypoCorrection Corrected =
676 CorrectTypo(DeclarationNameInfo(II, IILoc), LookupOrdinaryName, S, SS,
677 CCC, CTK_ErrorRecovery)) {
678 // FIXME: Support error recovery for the template-name case.
679 bool CanRecover = !IsTemplateName;
680 if (Corrected.isKeyword()) {
681 // We corrected to a keyword.
682 diagnoseTypo(Corrected,
683 PDiag(IsTemplateName ? diag::err_no_template_suggest
684 : diag::err_unknown_typename_suggest)
685 << II);
686 II = Corrected.getCorrectionAsIdentifierInfo();
687 } else {
688 // We found a similarly-named type or interface; suggest that.
689 if (!SS || !SS->isSet()) {
690 diagnoseTypo(Corrected,
691 PDiag(IsTemplateName ? diag::err_no_template_suggest
692 : diag::err_unknown_typename_suggest)
693 << II, CanRecover);
694 } else if (DeclContext *DC = computeDeclContext(*SS, false)) {
695 std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
696 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
697 II->getName().equals(CorrectedStr);
698 diagnoseTypo(Corrected,
699 PDiag(IsTemplateName
700 ? diag::err_no_member_template_suggest
701 : diag::err_unknown_nested_typename_suggest)
702 << II << DC << DroppedSpecifier << SS->getRange(),
703 CanRecover);
704 } else {
705 llvm_unreachable("could not have corrected a typo here")::llvm::llvm_unreachable_internal("could not have corrected a typo here"
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 705)
;
706 }
707
708 if (!CanRecover)
709 return;
710
711 CXXScopeSpec tmpSS;
712 if (Corrected.getCorrectionSpecifier())
713 tmpSS.MakeTrivial(Context, Corrected.getCorrectionSpecifier(),
714 SourceRange(IILoc));
715 // FIXME: Support class template argument deduction here.
716 SuggestedType =
717 getTypeName(*Corrected.getCorrectionAsIdentifierInfo(), IILoc, S,
718 tmpSS.isSet() ? &tmpSS : SS, false, false, nullptr,
719 /*IsCtorOrDtorName=*/false,
720 /*WantNontrivialTypeSourceInfo=*/true);
721 }
722 return;
723 }
724
725 if (getLangOpts().CPlusPlus && !IsTemplateName) {
726 // See if II is a class template that the user forgot to pass arguments to.
727 UnqualifiedId Name;
728 Name.setIdentifier(II, IILoc);
729 CXXScopeSpec EmptySS;
730 TemplateTy TemplateResult;
731 bool MemberOfUnknownSpecialization;
732 if (isTemplateName(S, SS ? *SS : EmptySS, /*hasTemplateKeyword=*/false,
733 Name, nullptr, true, TemplateResult,
734 MemberOfUnknownSpecialization) == TNK_Type_template) {
735 diagnoseMissingTemplateArguments(TemplateResult.get(), IILoc);
736 return;
737 }
738 }
739
740 // FIXME: Should we move the logic that tries to recover from a missing tag
741 // (struct, union, enum) from Parser::ParseImplicitInt here, instead?
742
743 if (!SS || (!SS->isSet() && !SS->isInvalid()))
744 Diag(IILoc, IsTemplateName ? diag::err_no_template
745 : diag::err_unknown_typename)
746 << II;
747 else if (DeclContext *DC = computeDeclContext(*SS, false))
748 Diag(IILoc, IsTemplateName ? diag::err_no_member_template
749 : diag::err_typename_nested_not_found)
750 << II << DC << SS->getRange();
751 else if (SS->isValid() && SS->getScopeRep()->containsErrors()) {
752 SuggestedType =
753 ActOnTypenameType(S, SourceLocation(), *SS, *II, IILoc).get();
754 } else if (isDependentScopeSpecifier(*SS)) {
755 unsigned DiagID = diag::err_typename_missing;
756 if (getLangOpts().MSVCCompat && isMicrosoftMissingTypename(SS, S))
757 DiagID = diag::ext_typename_missing;
758
759 Diag(SS->getRange().getBegin(), DiagID)
760 << SS->getScopeRep() << II->getName()
761 << SourceRange(SS->getRange().getBegin(), IILoc)
762 << FixItHint::CreateInsertion(SS->getRange().getBegin(), "typename ");
763 SuggestedType = ActOnTypenameType(S, SourceLocation(),
764 *SS, *II, IILoc).get();
765 } else {
766 assert(SS && SS->isInvalid() &&((SS && SS->isInvalid() && "Invalid scope specifier has already been diagnosed"
) ? static_cast<void> (0) : __assert_fail ("SS && SS->isInvalid() && \"Invalid scope specifier has already been diagnosed\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 767, __PRETTY_FUNCTION__))
767 "Invalid scope specifier has already been diagnosed")((SS && SS->isInvalid() && "Invalid scope specifier has already been diagnosed"
) ? static_cast<void> (0) : __assert_fail ("SS && SS->isInvalid() && \"Invalid scope specifier has already been diagnosed\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 767, __PRETTY_FUNCTION__))
;
768 }
769}
770
771/// Determine whether the given result set contains either a type name
772/// or
773static bool isResultTypeOrTemplate(LookupResult &R, const Token &NextToken) {
774 bool CheckTemplate = R.getSema().getLangOpts().CPlusPlus &&
775 NextToken.is(tok::less);
776
777 for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; ++I) {
778 if (isa<TypeDecl>(*I) || isa<ObjCInterfaceDecl>(*I))
779 return true;
780
781 if (CheckTemplate && isa<TemplateDecl>(*I))
782 return true;
783 }
784
785 return false;
786}
787
788static bool isTagTypeWithMissingTag(Sema &SemaRef, LookupResult &Result,
789 Scope *S, CXXScopeSpec &SS,
790 IdentifierInfo *&Name,
791 SourceLocation NameLoc) {
792 LookupResult R(SemaRef, Name, NameLoc, Sema::LookupTagName);
793 SemaRef.LookupParsedName(R, S, &SS);
794 if (TagDecl *Tag = R.getAsSingle<TagDecl>()) {
795 StringRef FixItTagName;
796 switch (Tag->getTagKind()) {
797 case TTK_Class:
798 FixItTagName = "class ";
799 break;
800
801 case TTK_Enum:
802 FixItTagName = "enum ";
803 break;
804
805 case TTK_Struct:
806 FixItTagName = "struct ";
807 break;
808
809 case TTK_Interface:
810 FixItTagName = "__interface ";
811 break;
812
813 case TTK_Union:
814 FixItTagName = "union ";
815 break;
816 }
817
818 StringRef TagName = FixItTagName.drop_back();
819 SemaRef.Diag(NameLoc, diag::err_use_of_tag_name_without_tag)
820 << Name << TagName << SemaRef.getLangOpts().CPlusPlus
821 << FixItHint::CreateInsertion(NameLoc, FixItTagName);
822
823 for (LookupResult::iterator I = Result.begin(), IEnd = Result.end();
824 I != IEnd; ++I)
825 SemaRef.Diag((*I)->getLocation(), diag::note_decl_hiding_tag_type)
826 << Name << TagName;
827
828 // Replace lookup results with just the tag decl.
829 Result.clear(Sema::LookupTagName);
830 SemaRef.LookupParsedName(Result, S, &SS);
831 return true;
832 }
833
834 return false;
835}
836
837/// Build a ParsedType for a simple-type-specifier with a nested-name-specifier.
838static ParsedType buildNestedType(Sema &S, CXXScopeSpec &SS,
839 QualType T, SourceLocation NameLoc) {
840 ASTContext &Context = S.Context;
841
842 TypeLocBuilder Builder;
843 Builder.pushTypeSpec(T).setNameLoc(NameLoc);
844
845 T = S.getElaboratedType(ETK_None, SS, T);
846 ElaboratedTypeLoc ElabTL = Builder.push<ElaboratedTypeLoc>(T);
847 ElabTL.setElaboratedKeywordLoc(SourceLocation());
848 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
849 return S.CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
850}
851
852Sema::NameClassification Sema::ClassifyName(Scope *S, CXXScopeSpec &SS,
853 IdentifierInfo *&Name,
854 SourceLocation NameLoc,
855 const Token &NextToken,
856 CorrectionCandidateCallback *CCC) {
857 DeclarationNameInfo NameInfo(Name, NameLoc);
858 ObjCMethodDecl *CurMethod = getCurMethodDecl();
859
860 assert(NextToken.isNot(tok::coloncolon) &&((NextToken.isNot(tok::coloncolon) && "parse nested name specifiers before calling ClassifyName"
) ? static_cast<void> (0) : __assert_fail ("NextToken.isNot(tok::coloncolon) && \"parse nested name specifiers before calling ClassifyName\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 861, __PRETTY_FUNCTION__))
861 "parse nested name specifiers before calling ClassifyName")((NextToken.isNot(tok::coloncolon) && "parse nested name specifiers before calling ClassifyName"
) ? static_cast<void> (0) : __assert_fail ("NextToken.isNot(tok::coloncolon) && \"parse nested name specifiers before calling ClassifyName\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 861, __PRETTY_FUNCTION__))
;
862 if (getLangOpts().CPlusPlus && SS.isSet() &&
863 isCurrentClassName(*Name, S, &SS)) {
864 // Per [class.qual]p2, this names the constructors of SS, not the
865 // injected-class-name. We don't have a classification for that.
866 // There's not much point caching this result, since the parser
867 // will reject it later.
868 return NameClassification::Unknown();
869 }
870
871 LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
872 LookupParsedName(Result, S, &SS, !CurMethod);
873
874 if (SS.isInvalid())
875 return NameClassification::Error();
876
877 // For unqualified lookup in a class template in MSVC mode, look into
878 // dependent base classes where the primary class template is known.
879 if (Result.empty() && SS.isEmpty() && getLangOpts().MSVCCompat) {
880 if (ParsedType TypeInBase =
881 recoverFromTypeInKnownDependentBase(*this, *Name, NameLoc))
882 return TypeInBase;
883 }
884
885 // Perform lookup for Objective-C instance variables (including automatically
886 // synthesized instance variables), if we're in an Objective-C method.
887 // FIXME: This lookup really, really needs to be folded in to the normal
888 // unqualified lookup mechanism.
889 if (SS.isEmpty() && CurMethod && !isResultTypeOrTemplate(Result, NextToken)) {
890 DeclResult Ivar = LookupIvarInObjCMethod(Result, S, Name);
891 if (Ivar.isInvalid())
892 return NameClassification::Error();
893 if (Ivar.isUsable())
894 return NameClassification::NonType(cast<NamedDecl>(Ivar.get()));
895
896 // We defer builtin creation until after ivar lookup inside ObjC methods.
897 if (Result.empty())
898 LookupBuiltin(Result);
899 }
900
901 bool SecondTry = false;
902 bool IsFilteredTemplateName = false;
903
904Corrected:
905 switch (Result.getResultKind()) {
906 case LookupResult::NotFound:
907 // If an unqualified-id is followed by a '(', then we have a function
908 // call.
909 if (SS.isEmpty() && NextToken.is(tok::l_paren)) {
910 // In C++, this is an ADL-only call.
911 // FIXME: Reference?
912 if (getLangOpts().CPlusPlus)
913 return NameClassification::UndeclaredNonType();
914
915 // C90 6.3.2.2:
916 // If the expression that precedes the parenthesized argument list in a
917 // function call consists solely of an identifier, and if no
918 // declaration is visible for this identifier, the identifier is
919 // implicitly declared exactly as if, in the innermost block containing
920 // the function call, the declaration
921 //
922 // extern int identifier ();
923 //
924 // appeared.
925 //
926 // We also allow this in C99 as an extension.
927 if (NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *Name, S))
928 return NameClassification::NonType(D);
929 }
930
931 if (getLangOpts().CPlusPlus20 && SS.isEmpty() && NextToken.is(tok::less)) {
932 // In C++20 onwards, this could be an ADL-only call to a function
933 // template, and we're required to assume that this is a template name.
934 //
935 // FIXME: Find a way to still do typo correction in this case.
936 TemplateName Template =
937 Context.getAssumedTemplateName(NameInfo.getName());
938 return NameClassification::UndeclaredTemplate(Template);
939 }
940
941 // In C, we first see whether there is a tag type by the same name, in
942 // which case it's likely that the user just forgot to write "enum",
943 // "struct", or "union".
944 if (!getLangOpts().CPlusPlus && !SecondTry &&
945 isTagTypeWithMissingTag(*this, Result, S, SS, Name, NameLoc)) {
946 break;
947 }
948
949 // Perform typo correction to determine if there is another name that is
950 // close to this name.
951 if (!SecondTry && CCC) {
952 SecondTry = true;
953 if (TypoCorrection Corrected =
954 CorrectTypo(Result.getLookupNameInfo(), Result.getLookupKind(), S,
955 &SS, *CCC, CTK_ErrorRecovery)) {
956 unsigned UnqualifiedDiag = diag::err_undeclared_var_use_suggest;
957 unsigned QualifiedDiag = diag::err_no_member_suggest;
958
959 NamedDecl *FirstDecl = Corrected.getFoundDecl();
960 NamedDecl *UnderlyingFirstDecl = Corrected.getCorrectionDecl();
961 if (getLangOpts().CPlusPlus && NextToken.is(tok::less) &&
962 UnderlyingFirstDecl && isa<TemplateDecl>(UnderlyingFirstDecl)) {
963 UnqualifiedDiag = diag::err_no_template_suggest;
964 QualifiedDiag = diag::err_no_member_template_suggest;
965 } else if (UnderlyingFirstDecl &&
966 (isa<TypeDecl>(UnderlyingFirstDecl) ||
967 isa<ObjCInterfaceDecl>(UnderlyingFirstDecl) ||
968 isa<ObjCCompatibleAliasDecl>(UnderlyingFirstDecl))) {
969 UnqualifiedDiag = diag::err_unknown_typename_suggest;
970 QualifiedDiag = diag::err_unknown_nested_typename_suggest;
971 }
972
973 if (SS.isEmpty()) {
974 diagnoseTypo(Corrected, PDiag(UnqualifiedDiag) << Name);
975 } else {// FIXME: is this even reachable? Test it.
976 std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
977 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
978 Name->getName().equals(CorrectedStr);
979 diagnoseTypo(Corrected, PDiag(QualifiedDiag)
980 << Name << computeDeclContext(SS, false)
981 << DroppedSpecifier << SS.getRange());
982 }
983
984 // Update the name, so that the caller has the new name.
985 Name = Corrected.getCorrectionAsIdentifierInfo();
986
987 // Typo correction corrected to a keyword.
988 if (Corrected.isKeyword())
989 return Name;
990
991 // Also update the LookupResult...
992 // FIXME: This should probably go away at some point
993 Result.clear();
994 Result.setLookupName(Corrected.getCorrection());
995 if (FirstDecl)
996 Result.addDecl(FirstDecl);
997
998 // If we found an Objective-C instance variable, let
999 // LookupInObjCMethod build the appropriate expression to
1000 // reference the ivar.
1001 // FIXME: This is a gross hack.
1002 if (ObjCIvarDecl *Ivar = Result.getAsSingle<ObjCIvarDecl>()) {
1003 DeclResult R =
1004 LookupIvarInObjCMethod(Result, S, Ivar->getIdentifier());
1005 if (R.isInvalid())
1006 return NameClassification::Error();
1007 if (R.isUsable())
1008 return NameClassification::NonType(Ivar);
1009 }
1010
1011 goto Corrected;
1012 }
1013 }
1014
1015 // We failed to correct; just fall through and let the parser deal with it.
1016 Result.suppressDiagnostics();
1017 return NameClassification::Unknown();
1018
1019 case LookupResult::NotFoundInCurrentInstantiation: {
1020 // We performed name lookup into the current instantiation, and there were
1021 // dependent bases, so we treat this result the same way as any other
1022 // dependent nested-name-specifier.
1023
1024 // C++ [temp.res]p2:
1025 // A name used in a template declaration or definition and that is
1026 // dependent on a template-parameter is assumed not to name a type
1027 // unless the applicable name lookup finds a type name or the name is
1028 // qualified by the keyword typename.
1029 //
1030 // FIXME: If the next token is '<', we might want to ask the parser to
1031 // perform some heroics to see if we actually have a
1032 // template-argument-list, which would indicate a missing 'template'
1033 // keyword here.
1034 return NameClassification::DependentNonType();
1035 }
1036
1037 case LookupResult::Found:
1038 case LookupResult::FoundOverloaded:
1039 case LookupResult::FoundUnresolvedValue:
1040 break;
1041
1042 case LookupResult::Ambiguous:
1043 if (getLangOpts().CPlusPlus && NextToken.is(tok::less) &&
1044 hasAnyAcceptableTemplateNames(Result, /*AllowFunctionTemplates=*/true,
1045 /*AllowDependent=*/false)) {
1046 // C++ [temp.local]p3:
1047 // A lookup that finds an injected-class-name (10.2) can result in an
1048 // ambiguity in certain cases (for example, if it is found in more than
1049 // one base class). If all of the injected-class-names that are found
1050 // refer to specializations of the same class template, and if the name
1051 // is followed by a template-argument-list, the reference refers to the
1052 // class template itself and not a specialization thereof, and is not
1053 // ambiguous.
1054 //
1055 // This filtering can make an ambiguous result into an unambiguous one,
1056 // so try again after filtering out template names.
1057 FilterAcceptableTemplateNames(Result);
1058 if (!Result.isAmbiguous()) {
1059 IsFilteredTemplateName = true;
1060 break;
1061 }
1062 }
1063
1064 // Diagnose the ambiguity and return an error.
1065 return NameClassification::Error();
1066 }
1067
1068 if (getLangOpts().CPlusPlus && NextToken.is(tok::less) &&
1069 (IsFilteredTemplateName ||
1070 hasAnyAcceptableTemplateNames(
1071 Result, /*AllowFunctionTemplates=*/true,
1072 /*AllowDependent=*/false,
1073 /*AllowNonTemplateFunctions*/ SS.isEmpty() &&
1074 getLangOpts().CPlusPlus20))) {
1075 // C++ [temp.names]p3:
1076 // After name lookup (3.4) finds that a name is a template-name or that
1077 // an operator-function-id or a literal- operator-id refers to a set of
1078 // overloaded functions any member of which is a function template if
1079 // this is followed by a <, the < is always taken as the delimiter of a
1080 // template-argument-list and never as the less-than operator.
1081 // C++2a [temp.names]p2:
1082 // A name is also considered to refer to a template if it is an
1083 // unqualified-id followed by a < and name lookup finds either one
1084 // or more functions or finds nothing.
1085 if (!IsFilteredTemplateName)
1086 FilterAcceptableTemplateNames(Result);
1087
1088 bool IsFunctionTemplate;
1089 bool IsVarTemplate;
1090 TemplateName Template;
1091 if (Result.end() - Result.begin() > 1) {
1092 IsFunctionTemplate = true;
1093 Template = Context.getOverloadedTemplateName(Result.begin(),
1094 Result.end());
1095 } else if (!Result.empty()) {
1096 auto *TD = cast<TemplateDecl>(getAsTemplateNameDecl(
1097 *Result.begin(), /*AllowFunctionTemplates=*/true,
1098 /*AllowDependent=*/false));
1099 IsFunctionTemplate = isa<FunctionTemplateDecl>(TD);
1100 IsVarTemplate = isa<VarTemplateDecl>(TD);
1101
1102 if (SS.isNotEmpty())
1103 Template =
1104 Context.getQualifiedTemplateName(SS.getScopeRep(),
1105 /*TemplateKeyword=*/false, TD);
1106 else
1107 Template = TemplateName(TD);
1108 } else {
1109 // All results were non-template functions. This is a function template
1110 // name.
1111 IsFunctionTemplate = true;
1112 Template = Context.getAssumedTemplateName(NameInfo.getName());
1113 }
1114
1115 if (IsFunctionTemplate) {
1116 // Function templates always go through overload resolution, at which
1117 // point we'll perform the various checks (e.g., accessibility) we need
1118 // to based on which function we selected.
1119 Result.suppressDiagnostics();
1120
1121 return NameClassification::FunctionTemplate(Template);
1122 }
1123
1124 return IsVarTemplate ? NameClassification::VarTemplate(Template)
1125 : NameClassification::TypeTemplate(Template);
1126 }
1127
1128 NamedDecl *FirstDecl = (*Result.begin())->getUnderlyingDecl();
1129 if (TypeDecl *Type = dyn_cast<TypeDecl>(FirstDecl)) {
1130 DiagnoseUseOfDecl(Type, NameLoc);
1131 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
1132 QualType T = Context.getTypeDeclType(Type);
1133 if (SS.isNotEmpty())
1134 return buildNestedType(*this, SS, T, NameLoc);
1135 return ParsedType::make(T);
1136 }
1137
1138 ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(FirstDecl);
1139 if (!Class) {
1140 // FIXME: It's unfortunate that we don't have a Type node for handling this.
1141 if (ObjCCompatibleAliasDecl *Alias =
1142 dyn_cast<ObjCCompatibleAliasDecl>(FirstDecl))
1143 Class = Alias->getClassInterface();
1144 }
1145
1146 if (Class) {
1147 DiagnoseUseOfDecl(Class, NameLoc);
1148
1149 if (NextToken.is(tok::period)) {
1150 // Interface. <something> is parsed as a property reference expression.
1151 // Just return "unknown" as a fall-through for now.
1152 Result.suppressDiagnostics();
1153 return NameClassification::Unknown();
1154 }
1155
1156 QualType T = Context.getObjCInterfaceType(Class);
1157 return ParsedType::make(T);
1158 }
1159
1160 if (isa<ConceptDecl>(FirstDecl))
1161 return NameClassification::Concept(
1162 TemplateName(cast<TemplateDecl>(FirstDecl)));
1163
1164 // We can have a type template here if we're classifying a template argument.
1165 if (isa<TemplateDecl>(FirstDecl) && !isa<FunctionTemplateDecl>(FirstDecl) &&
1166 !isa<VarTemplateDecl>(FirstDecl))
1167 return NameClassification::TypeTemplate(
1168 TemplateName(cast<TemplateDecl>(FirstDecl)));
1169
1170 // Check for a tag type hidden by a non-type decl in a few cases where it
1171 // seems likely a type is wanted instead of the non-type that was found.
1172 bool NextIsOp = NextToken.isOneOf(tok::amp, tok::star);
1173 if ((NextToken.is(tok::identifier) ||
1174 (NextIsOp &&
1175 FirstDecl->getUnderlyingDecl()->isFunctionOrFunctionTemplate())) &&
1176 isTagTypeWithMissingTag(*this, Result, S, SS, Name, NameLoc)) {
1177 TypeDecl *Type = Result.getAsSingle<TypeDecl>();
1178 DiagnoseUseOfDecl(Type, NameLoc);
1179 QualType T = Context.getTypeDeclType(Type);
1180 if (SS.isNotEmpty())
1181 return buildNestedType(*this, SS, T, NameLoc);
1182 return ParsedType::make(T);
1183 }
1184
1185 // If we already know which single declaration is referenced, just annotate
1186 // that declaration directly. Defer resolving even non-overloaded class
1187 // member accesses, as we need to defer certain access checks until we know
1188 // the context.
1189 bool ADL = UseArgumentDependentLookup(SS, Result, NextToken.is(tok::l_paren));
1190 if (Result.isSingleResult() && !ADL && !FirstDecl->isCXXClassMember())
1191 return NameClassification::NonType(Result.getRepresentativeDecl());
1192
1193 // Otherwise, this is an overload set that we will need to resolve later.
1194 Result.suppressDiagnostics();
1195 return NameClassification::OverloadSet(UnresolvedLookupExpr::Create(
1196 Context, Result.getNamingClass(), SS.getWithLocInContext(Context),
1197 Result.getLookupNameInfo(), ADL, Result.isOverloadedResult(),
1198 Result.begin(), Result.end()));
1199}
1200
1201ExprResult
1202Sema::ActOnNameClassifiedAsUndeclaredNonType(IdentifierInfo *Name,
1203 SourceLocation NameLoc) {
1204 assert(getLangOpts().CPlusPlus && "ADL-only call in C?")((getLangOpts().CPlusPlus && "ADL-only call in C?") ?
static_cast<void> (0) : __assert_fail ("getLangOpts().CPlusPlus && \"ADL-only call in C?\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1204, __PRETTY_FUNCTION__))
;
1205 CXXScopeSpec SS;
1206 LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
1207 return BuildDeclarationNameExpr(SS, Result, /*ADL=*/true);
1208}
1209
1210ExprResult
1211Sema::ActOnNameClassifiedAsDependentNonType(const CXXScopeSpec &SS,
1212 IdentifierInfo *Name,
1213 SourceLocation NameLoc,
1214 bool IsAddressOfOperand) {
1215 DeclarationNameInfo NameInfo(Name, NameLoc);
1216 return ActOnDependentIdExpression(SS, /*TemplateKWLoc=*/SourceLocation(),
1217 NameInfo, IsAddressOfOperand,
1218 /*TemplateArgs=*/nullptr);
1219}
1220
1221ExprResult Sema::ActOnNameClassifiedAsNonType(Scope *S, const CXXScopeSpec &SS,
1222 NamedDecl *Found,
1223 SourceLocation NameLoc,
1224 const Token &NextToken) {
1225 if (getCurMethodDecl() && SS.isEmpty())
1226 if (auto *Ivar = dyn_cast<ObjCIvarDecl>(Found->getUnderlyingDecl()))
1227 return BuildIvarRefExpr(S, NameLoc, Ivar);
1228
1229 // Reconstruct the lookup result.
1230 LookupResult Result(*this, Found->getDeclName(), NameLoc, LookupOrdinaryName);
1231 Result.addDecl(Found);
1232 Result.resolveKind();
1233
1234 bool ADL = UseArgumentDependentLookup(SS, Result, NextToken.is(tok::l_paren));
1235 return BuildDeclarationNameExpr(SS, Result, ADL);
1236}
1237
1238ExprResult Sema::ActOnNameClassifiedAsOverloadSet(Scope *S, Expr *E) {
1239 // For an implicit class member access, transform the result into a member
1240 // access expression if necessary.
1241 auto *ULE = cast<UnresolvedLookupExpr>(E);
1242 if ((*ULE->decls_begin())->isCXXClassMember()) {
1243 CXXScopeSpec SS;
1244 SS.Adopt(ULE->getQualifierLoc());
1245
1246 // Reconstruct the lookup result.
1247 LookupResult Result(*this, ULE->getName(), ULE->getNameLoc(),
1248 LookupOrdinaryName);
1249 Result.setNamingClass(ULE->getNamingClass());
1250 for (auto I = ULE->decls_begin(), E = ULE->decls_end(); I != E; ++I)
1251 Result.addDecl(*I, I.getAccess());
1252 Result.resolveKind();
1253 return BuildPossibleImplicitMemberExpr(SS, SourceLocation(), Result,
1254 nullptr, S);
1255 }
1256
1257 // Otherwise, this is already in the form we needed, and no further checks
1258 // are necessary.
1259 return ULE;
1260}
1261
1262Sema::TemplateNameKindForDiagnostics
1263Sema::getTemplateNameKindForDiagnostics(TemplateName Name) {
1264 auto *TD = Name.getAsTemplateDecl();
1265 if (!TD)
1266 return TemplateNameKindForDiagnostics::DependentTemplate;
1267 if (isa<ClassTemplateDecl>(TD))
1268 return TemplateNameKindForDiagnostics::ClassTemplate;
1269 if (isa<FunctionTemplateDecl>(TD))
1270 return TemplateNameKindForDiagnostics::FunctionTemplate;
1271 if (isa<VarTemplateDecl>(TD))
1272 return TemplateNameKindForDiagnostics::VarTemplate;
1273 if (isa<TypeAliasTemplateDecl>(TD))
1274 return TemplateNameKindForDiagnostics::AliasTemplate;
1275 if (isa<TemplateTemplateParmDecl>(TD))
1276 return TemplateNameKindForDiagnostics::TemplateTemplateParam;
1277 if (isa<ConceptDecl>(TD))
1278 return TemplateNameKindForDiagnostics::Concept;
1279 return TemplateNameKindForDiagnostics::DependentTemplate;
1280}
1281
1282void Sema::PushDeclContext(Scope *S, DeclContext *DC) {
1283 assert(DC->getLexicalParent() == CurContext &&((DC->getLexicalParent() == CurContext && "The next DeclContext should be lexically contained in the current one."
) ? static_cast<void> (0) : __assert_fail ("DC->getLexicalParent() == CurContext && \"The next DeclContext should be lexically contained in the current one.\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1284, __PRETTY_FUNCTION__))
1284 "The next DeclContext should be lexically contained in the current one.")((DC->getLexicalParent() == CurContext && "The next DeclContext should be lexically contained in the current one."
) ? static_cast<void> (0) : __assert_fail ("DC->getLexicalParent() == CurContext && \"The next DeclContext should be lexically contained in the current one.\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1284, __PRETTY_FUNCTION__))
;
1285 CurContext = DC;
1286 S->setEntity(DC);
1287}
1288
1289void Sema::PopDeclContext() {
1290 assert(CurContext && "DeclContext imbalance!")((CurContext && "DeclContext imbalance!") ? static_cast
<void> (0) : __assert_fail ("CurContext && \"DeclContext imbalance!\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1290, __PRETTY_FUNCTION__))
;
1291
1292 CurContext = CurContext->getLexicalParent();
1293 assert(CurContext && "Popped translation unit!")((CurContext && "Popped translation unit!") ? static_cast
<void> (0) : __assert_fail ("CurContext && \"Popped translation unit!\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1293, __PRETTY_FUNCTION__))
;
1294}
1295
1296Sema::SkippedDefinitionContext Sema::ActOnTagStartSkippedDefinition(Scope *S,
1297 Decl *D) {
1298 // Unlike PushDeclContext, the context to which we return is not necessarily
1299 // the containing DC of TD, because the new context will be some pre-existing
1300 // TagDecl definition instead of a fresh one.
1301 auto Result = static_cast<SkippedDefinitionContext>(CurContext);
1302 CurContext = cast<TagDecl>(D)->getDefinition();
1303 assert(CurContext && "skipping definition of undefined tag")((CurContext && "skipping definition of undefined tag"
) ? static_cast<void> (0) : __assert_fail ("CurContext && \"skipping definition of undefined tag\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1303, __PRETTY_FUNCTION__))
;
1304 // Start lookups from the parent of the current context; we don't want to look
1305 // into the pre-existing complete definition.
1306 S->setEntity(CurContext->getLookupParent());
1307 return Result;
1308}
1309
1310void Sema::ActOnTagFinishSkippedDefinition(SkippedDefinitionContext Context) {
1311 CurContext = static_cast<decltype(CurContext)>(Context);
1312}
1313
1314/// EnterDeclaratorContext - Used when we must lookup names in the context
1315/// of a declarator's nested name specifier.
1316///
1317void Sema::EnterDeclaratorContext(Scope *S, DeclContext *DC) {
1318 // C++0x [basic.lookup.unqual]p13:
1319 // A name used in the definition of a static data member of class
1320 // X (after the qualified-id of the static member) is looked up as
1321 // if the name was used in a member function of X.
1322 // C++0x [basic.lookup.unqual]p14:
1323 // If a variable member of a namespace is defined outside of the
1324 // scope of its namespace then any name used in the definition of
1325 // the variable member (after the declarator-id) is looked up as
1326 // if the definition of the variable member occurred in its
1327 // namespace.
1328 // Both of these imply that we should push a scope whose context
1329 // is the semantic context of the declaration. We can't use
1330 // PushDeclContext here because that context is not necessarily
1331 // lexically contained in the current context. Fortunately,
1332 // the containing scope should have the appropriate information.
1333
1334 assert(!S->getEntity() && "scope already has entity")((!S->getEntity() && "scope already has entity") ?
static_cast<void> (0) : __assert_fail ("!S->getEntity() && \"scope already has entity\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1334, __PRETTY_FUNCTION__))
;
1335
1336#ifndef NDEBUG
1337 Scope *Ancestor = S->getParent();
1338 while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent();
1339 assert(Ancestor->getEntity() == CurContext && "ancestor context mismatch")((Ancestor->getEntity() == CurContext && "ancestor context mismatch"
) ? static_cast<void> (0) : __assert_fail ("Ancestor->getEntity() == CurContext && \"ancestor context mismatch\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1339, __PRETTY_FUNCTION__))
;
1340#endif
1341
1342 CurContext = DC;
1343 S->setEntity(DC);
1344
1345 if (S->getParent()->isTemplateParamScope()) {
1346 // Also set the corresponding entities for all immediately-enclosing
1347 // template parameter scopes.
1348 EnterTemplatedContext(S->getParent(), DC);
1349 }
1350}
1351
1352void Sema::ExitDeclaratorContext(Scope *S) {
1353 assert(S->getEntity() == CurContext && "Context imbalance!")((S->getEntity() == CurContext && "Context imbalance!"
) ? static_cast<void> (0) : __assert_fail ("S->getEntity() == CurContext && \"Context imbalance!\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1353, __PRETTY_FUNCTION__))
;
1354
1355 // Switch back to the lexical context. The safety of this is
1356 // enforced by an assert in EnterDeclaratorContext.
1357 Scope *Ancestor = S->getParent();
1358 while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent();
1359 CurContext = Ancestor->getEntity();
1360
1361 // We don't need to do anything with the scope, which is going to
1362 // disappear.
1363}
1364
1365void Sema::EnterTemplatedContext(Scope *S, DeclContext *DC) {
1366 assert(S->isTemplateParamScope() &&((S->isTemplateParamScope() && "expected to be initializing a template parameter scope"
) ? static_cast<void> (0) : __assert_fail ("S->isTemplateParamScope() && \"expected to be initializing a template parameter scope\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1367, __PRETTY_FUNCTION__))
1367 "expected to be initializing a template parameter scope")((S->isTemplateParamScope() && "expected to be initializing a template parameter scope"
) ? static_cast<void> (0) : __assert_fail ("S->isTemplateParamScope() && \"expected to be initializing a template parameter scope\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1367, __PRETTY_FUNCTION__))
;
1368
1369 // C++20 [temp.local]p7:
1370 // In the definition of a member of a class template that appears outside
1371 // of the class template definition, the name of a member of the class
1372 // template hides the name of a template-parameter of any enclosing class
1373 // templates (but not a template-parameter of the member if the member is a
1374 // class or function template).
1375 // C++20 [temp.local]p9:
1376 // In the definition of a class template or in the definition of a member
1377 // of such a template that appears outside of the template definition, for
1378 // each non-dependent base class (13.8.2.1), if the name of the base class
1379 // or the name of a member of the base class is the same as the name of a
1380 // template-parameter, the base class name or member name hides the
1381 // template-parameter name (6.4.10).
1382 //
1383 // This means that a template parameter scope should be searched immediately
1384 // after searching the DeclContext for which it is a template parameter
1385 // scope. For example, for
1386 // template<typename T> template<typename U> template<typename V>
1387 // void N::A<T>::B<U>::f(...)
1388 // we search V then B<U> (and base classes) then U then A<T> (and base
1389 // classes) then T then N then ::.
1390 unsigned ScopeDepth = getTemplateDepth(S);
1391 for (; S && S->isTemplateParamScope(); S = S->getParent(), --ScopeDepth) {
1392 DeclContext *SearchDCAfterScope = DC;
1393 for (; DC; DC = DC->getLookupParent()) {
1394 if (const TemplateParameterList *TPL =
1395 cast<Decl>(DC)->getDescribedTemplateParams()) {
1396 unsigned DCDepth = TPL->getDepth() + 1;
1397 if (DCDepth > ScopeDepth)
1398 continue;
1399 if (ScopeDepth == DCDepth)
1400 SearchDCAfterScope = DC = DC->getLookupParent();
1401 break;
1402 }
1403 }
1404 S->setLookupEntity(SearchDCAfterScope);
1405 }
1406}
1407
1408void Sema::ActOnReenterFunctionContext(Scope* S, Decl *D) {
1409 // We assume that the caller has already called
1410 // ActOnReenterTemplateScope so getTemplatedDecl() works.
1411 FunctionDecl *FD = D->getAsFunction();
1412 if (!FD)
1413 return;
1414
1415 // Same implementation as PushDeclContext, but enters the context
1416 // from the lexical parent, rather than the top-level class.
1417 assert(CurContext == FD->getLexicalParent() &&((CurContext == FD->getLexicalParent() && "The next DeclContext should be lexically contained in the current one."
) ? static_cast<void> (0) : __assert_fail ("CurContext == FD->getLexicalParent() && \"The next DeclContext should be lexically contained in the current one.\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1418, __PRETTY_FUNCTION__))
1418 "The next DeclContext should be lexically contained in the current one.")((CurContext == FD->getLexicalParent() && "The next DeclContext should be lexically contained in the current one."
) ? static_cast<void> (0) : __assert_fail ("CurContext == FD->getLexicalParent() && \"The next DeclContext should be lexically contained in the current one.\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1418, __PRETTY_FUNCTION__))
;
1419 CurContext = FD;
1420 S->setEntity(CurContext);
1421
1422 for (unsigned P = 0, NumParams = FD->getNumParams(); P < NumParams; ++P) {
1423 ParmVarDecl *Param = FD->getParamDecl(P);
1424 // If the parameter has an identifier, then add it to the scope
1425 if (Param->getIdentifier()) {
1426 S->AddDecl(Param);
1427 IdResolver.AddDecl(Param);
1428 }
1429 }
1430}
1431
1432void Sema::ActOnExitFunctionContext() {
1433 // Same implementation as PopDeclContext, but returns to the lexical parent,
1434 // rather than the top-level class.
1435 assert(CurContext && "DeclContext imbalance!")((CurContext && "DeclContext imbalance!") ? static_cast
<void> (0) : __assert_fail ("CurContext && \"DeclContext imbalance!\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1435, __PRETTY_FUNCTION__))
;
1436 CurContext = CurContext->getLexicalParent();
1437 assert(CurContext && "Popped translation unit!")((CurContext && "Popped translation unit!") ? static_cast
<void> (0) : __assert_fail ("CurContext && \"Popped translation unit!\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1437, __PRETTY_FUNCTION__))
;
1438}
1439
1440/// Determine whether we allow overloading of the function
1441/// PrevDecl with another declaration.
1442///
1443/// This routine determines whether overloading is possible, not
1444/// whether some new function is actually an overload. It will return
1445/// true in C++ (where we can always provide overloads) or, as an
1446/// extension, in C when the previous function is already an
1447/// overloaded function declaration or has the "overloadable"
1448/// attribute.
1449static bool AllowOverloadingOfFunction(LookupResult &Previous,
1450 ASTContext &Context,
1451 const FunctionDecl *New) {
1452 if (Context.getLangOpts().CPlusPlus)
1453 return true;
1454
1455 if (Previous.getResultKind() == LookupResult::FoundOverloaded)
1456 return true;
1457
1458 return Previous.getResultKind() == LookupResult::Found &&
1459 (Previous.getFoundDecl()->hasAttr<OverloadableAttr>() ||
1460 New->hasAttr<OverloadableAttr>());
1461}
1462
1463/// Add this decl to the scope shadowed decl chains.
1464void Sema::PushOnScopeChains(NamedDecl *D, Scope *S, bool AddToContext) {
1465 // Move up the scope chain until we find the nearest enclosing
1466 // non-transparent context. The declaration will be introduced into this
1467 // scope.
1468 while (S->getEntity() && S->getEntity()->isTransparentContext())
1469 S = S->getParent();
1470
1471 // Add scoped declarations into their context, so that they can be
1472 // found later. Declarations without a context won't be inserted
1473 // into any context.
1474 if (AddToContext)
1475 CurContext->addDecl(D);
1476
1477 // Out-of-line definitions shouldn't be pushed into scope in C++, unless they
1478 // are function-local declarations.
1479 if (getLangOpts().CPlusPlus && D->isOutOfLine() && !S->getFnParent())
1480 return;
1481
1482 // Template instantiations should also not be pushed into scope.
1483 if (isa<FunctionDecl>(D) &&
1484 cast<FunctionDecl>(D)->isFunctionTemplateSpecialization())
1485 return;
1486
1487 // If this replaces anything in the current scope,
1488 IdentifierResolver::iterator I = IdResolver.begin(D->getDeclName()),
1489 IEnd = IdResolver.end();
1490 for (; I != IEnd; ++I) {
1491 if (S->isDeclScope(*I) && D->declarationReplaces(*I)) {
1492 S->RemoveDecl(*I);
1493 IdResolver.RemoveDecl(*I);
1494
1495 // Should only need to replace one decl.
1496 break;
1497 }
1498 }
1499
1500 S->AddDecl(D);
1501
1502 if (isa<LabelDecl>(D) && !cast<LabelDecl>(D)->isGnuLocal()) {
1503 // Implicitly-generated labels may end up getting generated in an order that
1504 // isn't strictly lexical, which breaks name lookup. Be careful to insert
1505 // the label at the appropriate place in the identifier chain.
1506 for (I = IdResolver.begin(D->getDeclName()); I != IEnd; ++I) {
1507 DeclContext *IDC = (*I)->getLexicalDeclContext()->getRedeclContext();
1508 if (IDC == CurContext) {
1509 if (!S->isDeclScope(*I))
1510 continue;
1511 } else if (IDC->Encloses(CurContext))
1512 break;
1513 }
1514
1515 IdResolver.InsertDeclAfter(I, D);
1516 } else {
1517 IdResolver.AddDecl(D);
1518 }
1519}
1520
1521bool Sema::isDeclInScope(NamedDecl *D, DeclContext *Ctx, Scope *S,
1522 bool AllowInlineNamespace) {
1523 return IdResolver.isDeclInScope(D, Ctx, S, AllowInlineNamespace);
1524}
1525
1526Scope *Sema::getScopeForDeclContext(Scope *S, DeclContext *DC) {
1527 DeclContext *TargetDC = DC->getPrimaryContext();
1528 do {
1529 if (DeclContext *ScopeDC = S->getEntity())
1530 if (ScopeDC->getPrimaryContext() == TargetDC)
1531 return S;
1532 } while ((S = S->getParent()));
1533
1534 return nullptr;
1535}
1536
1537static bool isOutOfScopePreviousDeclaration(NamedDecl *,
1538 DeclContext*,
1539 ASTContext&);
1540
1541/// Filters out lookup results that don't fall within the given scope
1542/// as determined by isDeclInScope.
1543void Sema::FilterLookupForScope(LookupResult &R, DeclContext *Ctx, Scope *S,
1544 bool ConsiderLinkage,
1545 bool AllowInlineNamespace) {
1546 LookupResult::Filter F = R.makeFilter();
1547 while (F.hasNext()) {
1548 NamedDecl *D = F.next();
1549
1550 if (isDeclInScope(D, Ctx, S, AllowInlineNamespace))
1551 continue;
1552
1553 if (ConsiderLinkage && isOutOfScopePreviousDeclaration(D, Ctx, Context))
1554 continue;
1555
1556 F.erase();
1557 }
1558
1559 F.done();
1560}
1561
1562/// We've determined that \p New is a redeclaration of \p Old. Check that they
1563/// have compatible owning modules.
1564bool Sema::CheckRedeclarationModuleOwnership(NamedDecl *New, NamedDecl *Old) {
1565 // FIXME: The Modules TS is not clear about how friend declarations are
1566 // to be treated. It's not meaningful to have different owning modules for
1567 // linkage in redeclarations of the same entity, so for now allow the
1568 // redeclaration and change the owning modules to match.
1569 if (New->getFriendObjectKind() &&
1570 Old->getOwningModuleForLinkage() != New->getOwningModuleForLinkage()) {
1571 New->setLocalOwningModule(Old->getOwningModule());
1572 makeMergedDefinitionVisible(New);
1573 return false;
1574 }
1575
1576 Module *NewM = New->getOwningModule();
1577 Module *OldM = Old->getOwningModule();
1578
1579 if (NewM && NewM->Kind == Module::PrivateModuleFragment)
1580 NewM = NewM->Parent;
1581 if (OldM && OldM->Kind == Module::PrivateModuleFragment)
1582 OldM = OldM->Parent;
1583
1584 if (NewM == OldM)
1585 return false;
1586
1587 bool NewIsModuleInterface = NewM && NewM->isModulePurview();
1588 bool OldIsModuleInterface = OldM && OldM->isModulePurview();
1589 if (NewIsModuleInterface || OldIsModuleInterface) {
1590 // C++ Modules TS [basic.def.odr] 6.2/6.7 [sic]:
1591 // if a declaration of D [...] appears in the purview of a module, all
1592 // other such declarations shall appear in the purview of the same module
1593 Diag(New->getLocation(), diag::err_mismatched_owning_module)
1594 << New
1595 << NewIsModuleInterface
1596 << (NewIsModuleInterface ? NewM->getFullModuleName() : "")
1597 << OldIsModuleInterface
1598 << (OldIsModuleInterface ? OldM->getFullModuleName() : "");
1599 Diag(Old->getLocation(), diag::note_previous_declaration);
1600 New->setInvalidDecl();
1601 return true;
1602 }
1603
1604 return false;
1605}
1606
1607static bool isUsingDecl(NamedDecl *D) {
1608 return isa<UsingShadowDecl>(D) ||
1609 isa<UnresolvedUsingTypenameDecl>(D) ||
1610 isa<UnresolvedUsingValueDecl>(D);
1611}
1612
1613/// Removes using shadow declarations from the lookup results.
1614static void RemoveUsingDecls(LookupResult &R) {
1615 LookupResult::Filter F = R.makeFilter();
1616 while (F.hasNext())
1617 if (isUsingDecl(F.next()))
1618 F.erase();
1619
1620 F.done();
1621}
1622
1623/// Check for this common pattern:
1624/// @code
1625/// class S {
1626/// S(const S&); // DO NOT IMPLEMENT
1627/// void operator=(const S&); // DO NOT IMPLEMENT
1628/// };
1629/// @endcode
1630static bool IsDisallowedCopyOrAssign(const CXXMethodDecl *D) {
1631 // FIXME: Should check for private access too but access is set after we get
1632 // the decl here.
1633 if (D->doesThisDeclarationHaveABody())
1634 return false;
1635
1636 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D))
1637 return CD->isCopyConstructor();
1638 return D->isCopyAssignmentOperator();
1639}
1640
1641// We need this to handle
1642//
1643// typedef struct {
1644// void *foo() { return 0; }
1645// } A;
1646//
1647// When we see foo we don't know if after the typedef we will get 'A' or '*A'
1648// for example. If 'A', foo will have external linkage. If we have '*A',
1649// foo will have no linkage. Since we can't know until we get to the end
1650// of the typedef, this function finds out if D might have non-external linkage.
1651// Callers should verify at the end of the TU if it D has external linkage or
1652// not.
1653bool Sema::mightHaveNonExternalLinkage(const DeclaratorDecl *D) {
1654 const DeclContext *DC = D->getDeclContext();
1655 while (!DC->isTranslationUnit()) {
1656 if (const RecordDecl *RD = dyn_cast<RecordDecl>(DC)){
1657 if (!RD->hasNameForLinkage())
1658 return true;
1659 }
1660 DC = DC->getParent();
1661 }
1662
1663 return !D->isExternallyVisible();
1664}
1665
1666// FIXME: This needs to be refactored; some other isInMainFile users want
1667// these semantics.
1668static bool isMainFileLoc(const Sema &S, SourceLocation Loc) {
1669 if (S.TUKind != TU_Complete)
1670 return false;
1671 return S.SourceMgr.isInMainFile(Loc);
1672}
1673
1674bool Sema::ShouldWarnIfUnusedFileScopedDecl(const DeclaratorDecl *D) const {
1675 assert(D)((D) ? static_cast<void> (0) : __assert_fail ("D", "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1675, __PRETTY_FUNCTION__))
;
1676
1677 if (D->isInvalidDecl() || D->isUsed() || D->hasAttr<UnusedAttr>())
1678 return false;
1679
1680 // Ignore all entities declared within templates, and out-of-line definitions
1681 // of members of class templates.
1682 if (D->getDeclContext()->isDependentContext() ||
1683 D->getLexicalDeclContext()->isDependentContext())
1684 return false;
1685
1686 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
1687 if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
1688 return false;
1689 // A non-out-of-line declaration of a member specialization was implicitly
1690 // instantiated; it's the out-of-line declaration that we're interested in.
1691 if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
1692 FD->getMemberSpecializationInfo() && !FD->isOutOfLine())
1693 return false;
1694
1695 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
1696 if (MD->isVirtual() || IsDisallowedCopyOrAssign(MD))
1697 return false;
1698 } else {
1699 // 'static inline' functions are defined in headers; don't warn.
1700 if (FD->isInlined() && !isMainFileLoc(*this, FD->getLocation()))
1701 return false;
1702 }
1703
1704 if (FD->doesThisDeclarationHaveABody() &&
1705 Context.DeclMustBeEmitted(FD))
1706 return false;
1707 } else if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
1708 // Constants and utility variables are defined in headers with internal
1709 // linkage; don't warn. (Unlike functions, there isn't a convenient marker
1710 // like "inline".)
1711 if (!isMainFileLoc(*this, VD->getLocation()))
1712 return false;
1713
1714 if (Context.DeclMustBeEmitted(VD))
1715 return false;
1716
1717 if (VD->isStaticDataMember() &&
1718 VD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
1719 return false;
1720 if (VD->isStaticDataMember() &&
1721 VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
1722 VD->getMemberSpecializationInfo() && !VD->isOutOfLine())
1723 return false;
1724
1725 if (VD->isInline() && !isMainFileLoc(*this, VD->getLocation()))
1726 return false;
1727 } else {
1728 return false;
1729 }
1730
1731 // Only warn for unused decls internal to the translation unit.
1732 // FIXME: This seems like a bogus check; it suppresses -Wunused-function
1733 // for inline functions defined in the main source file, for instance.
1734 return mightHaveNonExternalLinkage(D);
1735}
1736
1737void Sema::MarkUnusedFileScopedDecl(const DeclaratorDecl *D) {
1738 if (!D)
1739 return;
1740
1741 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
1742 const FunctionDecl *First = FD->getFirstDecl();
1743 if (FD != First && ShouldWarnIfUnusedFileScopedDecl(First))
1744 return; // First should already be in the vector.
1745 }
1746
1747 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
1748 const VarDecl *First = VD->getFirstDecl();
1749 if (VD != First && ShouldWarnIfUnusedFileScopedDecl(First))
1750 return; // First should already be in the vector.
1751 }
1752
1753 if (ShouldWarnIfUnusedFileScopedDecl(D))
1754 UnusedFileScopedDecls.push_back(D);
1755}
1756
1757static bool ShouldDiagnoseUnusedDecl(const NamedDecl *D) {
1758 if (D->isInvalidDecl())
1759 return false;
1760
1761 if (auto *DD = dyn_cast<DecompositionDecl>(D)) {
1762 // For a decomposition declaration, warn if none of the bindings are
1763 // referenced, instead of if the variable itself is referenced (which
1764 // it is, by the bindings' expressions).
1765 for (auto *BD : DD->bindings())
1766 if (BD->isReferenced())
1767 return false;
1768 } else if (!D->getDeclName()) {
1769 return false;
1770 } else if (D->isReferenced() || D->isUsed()) {
1771 return false;
1772 }
1773
1774 if (D->hasAttr<UnusedAttr>() || D->hasAttr<ObjCPreciseLifetimeAttr>())
1775 return false;
1776
1777 if (isa<LabelDecl>(D))
1778 return true;
1779
1780 // Except for labels, we only care about unused decls that are local to
1781 // functions.
1782 bool WithinFunction = D->getDeclContext()->isFunctionOrMethod();
1783 if (const auto *R = dyn_cast<CXXRecordDecl>(D->getDeclContext()))
1784 // For dependent types, the diagnostic is deferred.
1785 WithinFunction =
1786 WithinFunction || (R->isLocalClass() && !R->isDependentType());
1787 if (!WithinFunction)
1788 return false;
1789
1790 if (isa<TypedefNameDecl>(D))
1791 return true;
1792
1793 // White-list anything that isn't a local variable.
1794 if (!isa<VarDecl>(D) || isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D))
1795 return false;
1796
1797 // Types of valid local variables should be complete, so this should succeed.
1798 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
1799
1800 // White-list anything with an __attribute__((unused)) type.
1801 const auto *Ty = VD->getType().getTypePtr();
1802
1803 // Only look at the outermost level of typedef.
1804 if (const TypedefType *TT = Ty->getAs<TypedefType>()) {
1805 if (TT->getDecl()->hasAttr<UnusedAttr>())
1806 return false;
1807 }
1808
1809 // If we failed to complete the type for some reason, or if the type is
1810 // dependent, don't diagnose the variable.
1811 if (Ty->isIncompleteType() || Ty->isDependentType())
1812 return false;
1813
1814 // Look at the element type to ensure that the warning behaviour is
1815 // consistent for both scalars and arrays.
1816 Ty = Ty->getBaseElementTypeUnsafe();
1817
1818 if (const TagType *TT = Ty->getAs<TagType>()) {
1819 const TagDecl *Tag = TT->getDecl();
1820 if (Tag->hasAttr<UnusedAttr>())
1821 return false;
1822
1823 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Tag)) {
1824 if (!RD->hasTrivialDestructor() && !RD->hasAttr<WarnUnusedAttr>())
1825 return false;
1826
1827 if (const Expr *Init = VD->getInit()) {
1828 if (const ExprWithCleanups *Cleanups =
1829 dyn_cast<ExprWithCleanups>(Init))
1830 Init = Cleanups->getSubExpr();
1831 const CXXConstructExpr *Construct =
1832 dyn_cast<CXXConstructExpr>(Init);
1833 if (Construct && !Construct->isElidable()) {
1834 CXXConstructorDecl *CD = Construct->getConstructor();
1835 if (!CD->isTrivial() && !RD->hasAttr<WarnUnusedAttr>() &&
1836 (VD->getInit()->isValueDependent() || !VD->evaluateValue()))
1837 return false;
1838 }
1839
1840 // Suppress the warning if we don't know how this is constructed, and
1841 // it could possibly be non-trivial constructor.
1842 if (Init->isTypeDependent())
1843 for (const CXXConstructorDecl *Ctor : RD->ctors())
1844 if (!Ctor->isTrivial())
1845 return false;
1846 }
1847 }
1848 }
1849
1850 // TODO: __attribute__((unused)) templates?
1851 }
1852
1853 return true;
1854}
1855
1856static void GenerateFixForUnusedDecl(const NamedDecl *D, ASTContext &Ctx,
1857 FixItHint &Hint) {
1858 if (isa<LabelDecl>(D)) {
1859 SourceLocation AfterColon = Lexer::findLocationAfterToken(
1860 D->getEndLoc(), tok::colon, Ctx.getSourceManager(), Ctx.getLangOpts(),
1861 true);
1862 if (AfterColon.isInvalid())
1863 return;
1864 Hint = FixItHint::CreateRemoval(
1865 CharSourceRange::getCharRange(D->getBeginLoc(), AfterColon));
1866 }
1867}
1868
1869void Sema::DiagnoseUnusedNestedTypedefs(const RecordDecl *D) {
1870 if (D->getTypeForDecl()->isDependentType())
1871 return;
1872
1873 for (auto *TmpD : D->decls()) {
1874 if (const auto *T = dyn_cast<TypedefNameDecl>(TmpD))
1875 DiagnoseUnusedDecl(T);
1876 else if(const auto *R = dyn_cast<RecordDecl>(TmpD))
1877 DiagnoseUnusedNestedTypedefs(R);
1878 }
1879}
1880
1881/// DiagnoseUnusedDecl - Emit warnings about declarations that are not used
1882/// unless they are marked attr(unused).
1883void Sema::DiagnoseUnusedDecl(const NamedDecl *D) {
1884 if (!ShouldDiagnoseUnusedDecl(D))
1885 return;
1886
1887 if (auto *TD = dyn_cast<TypedefNameDecl>(D)) {
1888 // typedefs can be referenced later on, so the diagnostics are emitted
1889 // at end-of-translation-unit.
1890 UnusedLocalTypedefNameCandidates.insert(TD);
1891 return;
1892 }
1893
1894 FixItHint Hint;
1895 GenerateFixForUnusedDecl(D, Context, Hint);
1896
1897 unsigned DiagID;
1898 if (isa<VarDecl>(D) && cast<VarDecl>(D)->isExceptionVariable())
1899 DiagID = diag::warn_unused_exception_param;
1900 else if (isa<LabelDecl>(D))
1901 DiagID = diag::warn_unused_label;
1902 else
1903 DiagID = diag::warn_unused_variable;
1904
1905 Diag(D->getLocation(), DiagID) << D << Hint;
1906}
1907
1908static void CheckPoppedLabel(LabelDecl *L, Sema &S) {
1909 // Verify that we have no forward references left. If so, there was a goto
1910 // or address of a label taken, but no definition of it. Label fwd
1911 // definitions are indicated with a null substmt which is also not a resolved
1912 // MS inline assembly label name.
1913 bool Diagnose = false;
1914 if (L->isMSAsmLabel())
1915 Diagnose = !L->isResolvedMSAsmLabel();
1916 else
1917 Diagnose = L->getStmt() == nullptr;
1918 if (Diagnose)
1919 S.Diag(L->getLocation(), diag::err_undeclared_label_use) << L;
1920}
1921
1922void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) {
1923 S->mergeNRVOIntoParent();
1924
1925 if (S->decl_empty()) return;
1926 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) &&(((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope
)) && "Scope shouldn't contain decls!") ? static_cast
<void> (0) : __assert_fail ("(S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && \"Scope shouldn't contain decls!\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1927, __PRETTY_FUNCTION__))
1927 "Scope shouldn't contain decls!")(((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope
)) && "Scope shouldn't contain decls!") ? static_cast
<void> (0) : __assert_fail ("(S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && \"Scope shouldn't contain decls!\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1927, __PRETTY_FUNCTION__))
;
1928
1929 for (auto *TmpD : S->decls()) {
1930 assert(TmpD && "This decl didn't get pushed??")((TmpD && "This decl didn't get pushed??") ? static_cast
<void> (0) : __assert_fail ("TmpD && \"This decl didn't get pushed??\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1930, __PRETTY_FUNCTION__))
;
1931
1932 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?")((isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?"
) ? static_cast<void> (0) : __assert_fail ("isa<NamedDecl>(TmpD) && \"Decl isn't NamedDecl?\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 1932, __PRETTY_FUNCTION__))
;
1933 NamedDecl *D = cast<NamedDecl>(TmpD);
1934
1935 // Diagnose unused variables in this scope.
1936 if (!S->hasUnrecoverableErrorOccurred()) {
1937 DiagnoseUnusedDecl(D);
1938 if (const auto *RD = dyn_cast<RecordDecl>(D))
1939 DiagnoseUnusedNestedTypedefs(RD);
1940 }
1941
1942 if (!D->getDeclName()) continue;
1943
1944 // If this was a forward reference to a label, verify it was defined.
1945 if (LabelDecl *LD = dyn_cast<LabelDecl>(D))
1946 CheckPoppedLabel(LD, *this);
1947
1948 // Remove this name from our lexical scope, and warn on it if we haven't
1949 // already.
1950 IdResolver.RemoveDecl(D);
1951 auto ShadowI = ShadowingDecls.find(D);
1952 if (ShadowI != ShadowingDecls.end()) {
1953 if (const auto *FD = dyn_cast<FieldDecl>(ShadowI->second)) {
1954 Diag(D->getLocation(), diag::warn_ctor_parm_shadows_field)
1955 << D << FD << FD->getParent();
1956 Diag(FD->getLocation(), diag::note_previous_declaration);
1957 }
1958 ShadowingDecls.erase(ShadowI);
1959 }
1960 }
1961}
1962
1963/// Look for an Objective-C class in the translation unit.
1964///
1965/// \param Id The name of the Objective-C class we're looking for. If
1966/// typo-correction fixes this name, the Id will be updated
1967/// to the fixed name.
1968///
1969/// \param IdLoc The location of the name in the translation unit.
1970///
1971/// \param DoTypoCorrection If true, this routine will attempt typo correction
1972/// if there is no class with the given name.
1973///
1974/// \returns The declaration of the named Objective-C class, or NULL if the
1975/// class could not be found.
1976ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *&Id,
1977 SourceLocation IdLoc,
1978 bool DoTypoCorrection) {
1979 // The third "scope" argument is 0 since we aren't enabling lazy built-in
1980 // creation from this context.
1981 NamedDecl *IDecl = LookupSingleName(TUScope, Id, IdLoc, LookupOrdinaryName);
1982
1983 if (!IDecl && DoTypoCorrection) {
1984 // Perform typo correction at the given location, but only if we
1985 // find an Objective-C class name.
1986 DeclFilterCCC<ObjCInterfaceDecl> CCC{};
1987 if (TypoCorrection C =
1988 CorrectTypo(DeclarationNameInfo(Id, IdLoc), LookupOrdinaryName,
1989 TUScope, nullptr, CCC, CTK_ErrorRecovery)) {
1990 diagnoseTypo(C, PDiag(diag::err_undef_interface_suggest) << Id);
1991 IDecl = C.getCorrectionDeclAs<ObjCInterfaceDecl>();
1992 Id = IDecl->getIdentifier();
1993 }
1994 }
1995 ObjCInterfaceDecl *Def = dyn_cast_or_null<ObjCInterfaceDecl>(IDecl);
1996 // This routine must always return a class definition, if any.
1997 if (Def && Def->getDefinition())
1998 Def = Def->getDefinition();
1999 return Def;
2000}
2001
2002/// getNonFieldDeclScope - Retrieves the innermost scope, starting
2003/// from S, where a non-field would be declared. This routine copes
2004/// with the difference between C and C++ scoping rules in structs and
2005/// unions. For example, the following code is well-formed in C but
2006/// ill-formed in C++:
2007/// @code
2008/// struct S6 {
2009/// enum { BAR } e;
2010/// };
2011///
2012/// void test_S6() {
2013/// struct S6 a;
2014/// a.e = BAR;
2015/// }
2016/// @endcode
2017/// For the declaration of BAR, this routine will return a different
2018/// scope. The scope S will be the scope of the unnamed enumeration
2019/// within S6. In C++, this routine will return the scope associated
2020/// with S6, because the enumeration's scope is a transparent
2021/// context but structures can contain non-field names. In C, this
2022/// routine will return the translation unit scope, since the
2023/// enumeration's scope is a transparent context and structures cannot
2024/// contain non-field names.
2025Scope *Sema::getNonFieldDeclScope(Scope *S) {
2026 while (((S->getFlags() & Scope::DeclScope) == 0) ||
2027 (S->getEntity() && S->getEntity()->isTransparentContext()) ||
2028 (S->isClassScope() && !getLangOpts().CPlusPlus))
2029 S = S->getParent();
2030 return S;
2031}
2032
2033static StringRef getHeaderName(Builtin::Context &BuiltinInfo, unsigned ID,
2034 ASTContext::GetBuiltinTypeError Error) {
2035 switch (Error) {
2036 case ASTContext::GE_None:
2037 return "";
2038 case ASTContext::GE_Missing_type:
2039 return BuiltinInfo.getHeaderName(ID);
2040 case ASTContext::GE_Missing_stdio:
2041 return "stdio.h";
2042 case ASTContext::GE_Missing_setjmp:
2043 return "setjmp.h";
2044 case ASTContext::GE_Missing_ucontext:
2045 return "ucontext.h";
2046 }
2047 llvm_unreachable("unhandled error kind")::llvm::llvm_unreachable_internal("unhandled error kind", "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 2047)
;
2048}
2049
2050FunctionDecl *Sema::CreateBuiltin(IdentifierInfo *II, QualType Type,
2051 unsigned ID, SourceLocation Loc) {
2052 DeclContext *Parent = Context.getTranslationUnitDecl();
2053
2054 if (getLangOpts().CPlusPlus) {
2055 LinkageSpecDecl *CLinkageDecl = LinkageSpecDecl::Create(
2056 Context, Parent, Loc, Loc, LinkageSpecDecl::lang_c, false);
2057 CLinkageDecl->setImplicit();
2058 Parent->addDecl(CLinkageDecl);
2059 Parent = CLinkageDecl;
2060 }
2061
2062 FunctionDecl *New = FunctionDecl::Create(Context, Parent, Loc, Loc, II, Type,
2063 /*TInfo=*/nullptr, SC_Extern, false,
2064 Type->isFunctionProtoType());
2065 New->setImplicit();
2066 New->addAttr(BuiltinAttr::CreateImplicit(Context, ID));
2067
2068 // Create Decl objects for each parameter, adding them to the
2069 // FunctionDecl.
2070 if (const FunctionProtoType *FT = dyn_cast<FunctionProtoType>(Type)) {
2071 SmallVector<ParmVarDecl *, 16> Params;
2072 for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
2073 ParmVarDecl *parm = ParmVarDecl::Create(
2074 Context, New, SourceLocation(), SourceLocation(), nullptr,
2075 FT->getParamType(i), /*TInfo=*/nullptr, SC_None, nullptr);
2076 parm->setScopeInfo(0, i);
2077 Params.push_back(parm);
2078 }
2079 New->setParams(Params);
2080 }
2081
2082 AddKnownFunctionAttributes(New);
2083 return New;
2084}
2085
2086/// LazilyCreateBuiltin - The specified Builtin-ID was first used at
2087/// file scope. lazily create a decl for it. ForRedeclaration is true
2088/// if we're creating this built-in in anticipation of redeclaring the
2089/// built-in.
2090NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID,
2091 Scope *S, bool ForRedeclaration,
2092 SourceLocation Loc) {
2093 LookupNecessaryTypesForBuiltin(S, ID);
2094
2095 ASTContext::GetBuiltinTypeError Error;
2096 QualType R = Context.GetBuiltinType(ID, Error);
2097 if (Error) {
2098 if (!ForRedeclaration)
2099 return nullptr;
2100
2101 // If we have a builtin without an associated type we should not emit a
2102 // warning when we were not able to find a type for it.
2103 if (Error == ASTContext::GE_Missing_type ||
2104 Context.BuiltinInfo.allowTypeMismatch(ID))
2105 return nullptr;
2106
2107 // If we could not find a type for setjmp it is because the jmp_buf type was
2108 // not defined prior to the setjmp declaration.
2109 if (Error == ASTContext::GE_Missing_setjmp) {
2110 Diag(Loc, diag::warn_implicit_decl_no_jmp_buf)
2111 << Context.BuiltinInfo.getName(ID);
2112 return nullptr;
2113 }
2114
2115 // Generally, we emit a warning that the declaration requires the
2116 // appropriate header.
2117 Diag(Loc, diag::warn_implicit_decl_requires_sysheader)
2118 << getHeaderName(Context.BuiltinInfo, ID, Error)
2119 << Context.BuiltinInfo.getName(ID);
2120 return nullptr;
2121 }
2122
2123 if (!ForRedeclaration &&
2124 (Context.BuiltinInfo.isPredefinedLibFunction(ID) ||
2125 Context.BuiltinInfo.isHeaderDependentFunction(ID))) {
2126 Diag(Loc, diag::ext_implicit_lib_function_decl)
2127 << Context.BuiltinInfo.getName(ID) << R;
2128 if (const char *Header = Context.BuiltinInfo.getHeaderName(ID))
2129 Diag(Loc, diag::note_include_header_or_declare)
2130 << Header << Context.BuiltinInfo.getName(ID);
2131 }
2132
2133 if (R.isNull())
2134 return nullptr;
2135
2136 FunctionDecl *New = CreateBuiltin(II, R, ID, Loc);
2137 RegisterLocallyScopedExternCDecl(New, S);
2138
2139 // TUScope is the translation-unit scope to insert this function into.
2140 // FIXME: This is hideous. We need to teach PushOnScopeChains to
2141 // relate Scopes to DeclContexts, and probably eliminate CurContext
2142 // entirely, but we're not there yet.
2143 DeclContext *SavedContext = CurContext;
2144 CurContext = New->getDeclContext();
2145 PushOnScopeChains(New, TUScope);
2146 CurContext = SavedContext;
2147 return New;
2148}
2149
2150/// Typedef declarations don't have linkage, but they still denote the same
2151/// entity if their types are the same.
2152/// FIXME: This is notionally doing the same thing as ASTReaderDecl's
2153/// isSameEntity.
2154static void filterNonConflictingPreviousTypedefDecls(Sema &S,
2155 TypedefNameDecl *Decl,
2156 LookupResult &Previous) {
2157 // This is only interesting when modules are enabled.
2158 if (!S.getLangOpts().Modules && !S.getLangOpts().ModulesLocalVisibility)
2159 return;
2160
2161 // Empty sets are uninteresting.
2162 if (Previous.empty())
2163 return;
2164
2165 LookupResult::Filter Filter = Previous.makeFilter();
2166 while (Filter.hasNext()) {
2167 NamedDecl *Old = Filter.next();
2168
2169 // Non-hidden declarations are never ignored.
2170 if (S.isVisible(Old))
2171 continue;
2172
2173 // Declarations of the same entity are not ignored, even if they have
2174 // different linkages.
2175 if (auto *OldTD = dyn_cast<TypedefNameDecl>(Old)) {
2176 if (S.Context.hasSameType(OldTD->getUnderlyingType(),
2177 Decl->getUnderlyingType()))
2178 continue;
2179
2180 // If both declarations give a tag declaration a typedef name for linkage
2181 // purposes, then they declare the same entity.
2182 if (OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true) &&
2183 Decl->getAnonDeclWithTypedefName())
2184 continue;
2185 }
2186
2187 Filter.erase();
2188 }
2189
2190 Filter.done();
2191}
2192
2193bool Sema::isIncompatibleTypedef(TypeDecl *Old, TypedefNameDecl *New) {
2194 QualType OldType;
2195 if (TypedefNameDecl *OldTypedef = dyn_cast<TypedefNameDecl>(Old))
2196 OldType = OldTypedef->getUnderlyingType();
2197 else
2198 OldType = Context.getTypeDeclType(Old);
2199 QualType NewType = New->getUnderlyingType();
2200
2201 if (NewType->isVariablyModifiedType()) {
2202 // Must not redefine a typedef with a variably-modified type.
2203 int Kind = isa<TypeAliasDecl>(Old) ? 1 : 0;
2204 Diag(New->getLocation(), diag::err_redefinition_variably_modified_typedef)
2205 << Kind << NewType;
2206 if (Old->getLocation().isValid())
2207 notePreviousDefinition(Old, New->getLocation());
2208 New->setInvalidDecl();
2209 return true;
2210 }
2211
2212 if (OldType != NewType &&
2213 !OldType->isDependentType() &&
2214 !NewType->isDependentType() &&
2215 !Context.hasSameType(OldType, NewType)) {
2216 int Kind = isa<TypeAliasDecl>(Old) ? 1 : 0;
2217 Diag(New->getLocation(), diag::err_redefinition_different_typedef)
2218 << Kind << NewType << OldType;
2219 if (Old->getLocation().isValid())
2220 notePreviousDefinition(Old, New->getLocation());
2221 New->setInvalidDecl();
2222 return true;
2223 }
2224 return false;
2225}
2226
2227/// MergeTypedefNameDecl - We just parsed a typedef 'New' which has the
2228/// same name and scope as a previous declaration 'Old'. Figure out
2229/// how to resolve this situation, merging decls or emitting
2230/// diagnostics as appropriate. If there was an error, set New to be invalid.
2231///
2232void Sema::MergeTypedefNameDecl(Scope *S, TypedefNameDecl *New,
2233 LookupResult &OldDecls) {
2234 // If the new decl is known invalid already, don't bother doing any
2235 // merging checks.
2236 if (New->isInvalidDecl()) return;
2237
2238 // Allow multiple definitions for ObjC built-in typedefs.
2239 // FIXME: Verify the underlying types are equivalent!
2240 if (getLangOpts().ObjC) {
2241 const IdentifierInfo *TypeID = New->getIdentifier();
2242 switch (TypeID->getLength()) {
2243 default: break;
2244 case 2:
2245 {
2246 if (!TypeID->isStr("id"))
2247 break;
2248 QualType T = New->getUnderlyingType();
2249 if (!T->isPointerType())
2250 break;
2251 if (!T->isVoidPointerType()) {
2252 QualType PT = T->castAs<PointerType>()->getPointeeType();
2253 if (!PT->isStructureType())
2254 break;
2255 }
2256 Context.setObjCIdRedefinitionType(T);
2257 // Install the built-in type for 'id', ignoring the current definition.
2258 New->setTypeForDecl(Context.getObjCIdType().getTypePtr());
2259 return;
2260 }
2261 case 5:
2262 if (!TypeID->isStr("Class"))
2263 break;
2264 Context.setObjCClassRedefinitionType(New->getUnderlyingType());
2265 // Install the built-in type for 'Class', ignoring the current definition.
2266 New->setTypeForDecl(Context.getObjCClassType().getTypePtr());
2267 return;
2268 case 3:
2269 if (!TypeID->isStr("SEL"))
2270 break;
2271 Context.setObjCSelRedefinitionType(New->getUnderlyingType());
2272 // Install the built-in type for 'SEL', ignoring the current definition.
2273 New->setTypeForDecl(Context.getObjCSelType().getTypePtr());
2274 return;
2275 }
2276 // Fall through - the typedef name was not a builtin type.
2277 }
2278
2279 // Verify the old decl was also a type.
2280 TypeDecl *Old = OldDecls.getAsSingle<TypeDecl>();
2281 if (!Old) {
2282 Diag(New->getLocation(), diag::err_redefinition_different_kind)
2283 << New->getDeclName();
2284
2285 NamedDecl *OldD = OldDecls.getRepresentativeDecl();
2286 if (OldD->getLocation().isValid())
2287 notePreviousDefinition(OldD, New->getLocation());
2288
2289 return New->setInvalidDecl();
2290 }
2291
2292 // If the old declaration is invalid, just give up here.
2293 if (Old->isInvalidDecl())
2294 return New->setInvalidDecl();
2295
2296 if (auto *OldTD = dyn_cast<TypedefNameDecl>(Old)) {
2297 auto *OldTag = OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true);
2298 auto *NewTag = New->getAnonDeclWithTypedefName();
2299 NamedDecl *Hidden = nullptr;
2300 if (OldTag && NewTag &&
2301 OldTag->getCanonicalDecl() != NewTag->getCanonicalDecl() &&
2302 !hasVisibleDefinition(OldTag, &Hidden)) {
2303 // There is a definition of this tag, but it is not visible. Use it
2304 // instead of our tag.
2305 New->setTypeForDecl(OldTD->getTypeForDecl());
2306 if (OldTD->isModed())
2307 New->setModedTypeSourceInfo(OldTD->getTypeSourceInfo(),
2308 OldTD->getUnderlyingType());
2309 else
2310 New->setTypeSourceInfo(OldTD->getTypeSourceInfo());
2311
2312 // Make the old tag definition visible.
2313 makeMergedDefinitionVisible(Hidden);
2314
2315 // If this was an unscoped enumeration, yank all of its enumerators
2316 // out of the scope.
2317 if (isa<EnumDecl>(NewTag)) {
2318 Scope *EnumScope = getNonFieldDeclScope(S);
2319 for (auto *D : NewTag->decls()) {
2320 auto *ED = cast<EnumConstantDecl>(D);
2321 assert(EnumScope->isDeclScope(ED))((EnumScope->isDeclScope(ED)) ? static_cast<void> (0
) : __assert_fail ("EnumScope->isDeclScope(ED)", "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 2321, __PRETTY_FUNCTION__))
;
2322 EnumScope->RemoveDecl(ED);
2323 IdResolver.RemoveDecl(ED);
2324 ED->getLexicalDeclContext()->removeDecl(ED);
2325 }
2326 }
2327 }
2328 }
2329
2330 // If the typedef types are not identical, reject them in all languages and
2331 // with any extensions enabled.
2332 if (isIncompatibleTypedef(Old, New))
2333 return;
2334
2335 // The types match. Link up the redeclaration chain and merge attributes if
2336 // the old declaration was a typedef.
2337 if (TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Old)) {
2338 New->setPreviousDecl(Typedef);
2339 mergeDeclAttributes(New, Old);
2340 }
2341
2342 if (getLangOpts().MicrosoftExt)
2343 return;
2344
2345 if (getLangOpts().CPlusPlus) {
2346 // C++ [dcl.typedef]p2:
2347 // In a given non-class scope, a typedef specifier can be used to
2348 // redefine the name of any type declared in that scope to refer
2349 // to the type to which it already refers.
2350 if (!isa<CXXRecordDecl>(CurContext))
2351 return;
2352
2353 // C++0x [dcl.typedef]p4:
2354 // In a given class scope, a typedef specifier can be used to redefine
2355 // any class-name declared in that scope that is not also a typedef-name
2356 // to refer to the type to which it already refers.
2357 //
2358 // This wording came in via DR424, which was a correction to the
2359 // wording in DR56, which accidentally banned code like:
2360 //
2361 // struct S {
2362 // typedef struct A { } A;
2363 // };
2364 //
2365 // in the C++03 standard. We implement the C++0x semantics, which
2366 // allow the above but disallow
2367 //
2368 // struct S {
2369 // typedef int I;
2370 // typedef int I;
2371 // };
2372 //
2373 // since that was the intent of DR56.
2374 if (!isa<TypedefNameDecl>(Old))
2375 return;
2376
2377 Diag(New->getLocation(), diag::err_redefinition)
2378 << New->getDeclName();
2379 notePreviousDefinition(Old, New->getLocation());
2380 return New->setInvalidDecl();
2381 }
2382
2383 // Modules always permit redefinition of typedefs, as does C11.
2384 if (getLangOpts().Modules || getLangOpts().C11)
2385 return;
2386
2387 // If we have a redefinition of a typedef in C, emit a warning. This warning
2388 // is normally mapped to an error, but can be controlled with
2389 // -Wtypedef-redefinition. If either the original or the redefinition is
2390 // in a system header, don't emit this for compatibility with GCC.
2391 if (getDiagnostics().getSuppressSystemWarnings() &&
2392 // Some standard types are defined implicitly in Clang (e.g. OpenCL).
2393 (Old->isImplicit() ||
2394 Context.getSourceManager().isInSystemHeader(Old->getLocation()) ||
2395 Context.getSourceManager().isInSystemHeader(New->getLocation())))
2396 return;
2397
2398 Diag(New->getLocation(), diag::ext_redefinition_of_typedef)
2399 << New->getDeclName();
2400 notePreviousDefinition(Old, New->getLocation());
2401}
2402
2403/// DeclhasAttr - returns true if decl Declaration already has the target
2404/// attribute.
2405static bool DeclHasAttr(const Decl *D, const Attr *A) {
2406 const OwnershipAttr *OA = dyn_cast<OwnershipAttr>(A);
2407 const AnnotateAttr *Ann = dyn_cast<AnnotateAttr>(A);
2408 for (const auto *i : D->attrs())
2409 if (i->getKind() == A->getKind()) {
2410 if (Ann) {
2411 if (Ann->getAnnotation() == cast<AnnotateAttr>(i)->getAnnotation())
2412 return true;
2413 continue;
2414 }
2415 // FIXME: Don't hardcode this check
2416 if (OA && isa<OwnershipAttr>(i))
2417 return OA->getOwnKind() == cast<OwnershipAttr>(i)->getOwnKind();
2418 return true;
2419 }
2420
2421 return false;
2422}
2423
2424static bool isAttributeTargetADefinition(Decl *D) {
2425 if (VarDecl *VD = dyn_cast<VarDecl>(D))
2426 return VD->isThisDeclarationADefinition();
2427 if (TagDecl *TD = dyn_cast<TagDecl>(D))
2428 return TD->isCompleteDefinition() || TD->isBeingDefined();
2429 return true;
2430}
2431
2432/// Merge alignment attributes from \p Old to \p New, taking into account the
2433/// special semantics of C11's _Alignas specifier and C++11's alignas attribute.
2434///
2435/// \return \c true if any attributes were added to \p New.
2436static bool mergeAlignedAttrs(Sema &S, NamedDecl *New, Decl *Old) {
2437 // Look for alignas attributes on Old, and pick out whichever attribute
2438 // specifies the strictest alignment requirement.
2439 AlignedAttr *OldAlignasAttr = nullptr;
2440 AlignedAttr *OldStrictestAlignAttr = nullptr;
2441 unsigned OldAlign = 0;
2442 for (auto *I : Old->specific_attrs<AlignedAttr>()) {
2443 // FIXME: We have no way of representing inherited dependent alignments
2444 // in a case like:
2445 // template<int A, int B> struct alignas(A) X;
2446 // template<int A, int B> struct alignas(B) X {};
2447 // For now, we just ignore any alignas attributes which are not on the
2448 // definition in such a case.
2449 if (I->isAlignmentDependent())
2450 return false;
2451
2452 if (I->isAlignas())
2453 OldAlignasAttr = I;
2454
2455 unsigned Align = I->getAlignment(S.Context);
2456 if (Align > OldAlign) {
2457 OldAlign = Align;
2458 OldStrictestAlignAttr = I;
2459 }
2460 }
2461
2462 // Look for alignas attributes on New.
2463 AlignedAttr *NewAlignasAttr = nullptr;
2464 unsigned NewAlign = 0;
2465 for (auto *I : New->specific_attrs<AlignedAttr>()) {
2466 if (I->isAlignmentDependent())
2467 return false;
2468
2469 if (I->isAlignas())
2470 NewAlignasAttr = I;
2471
2472 unsigned Align = I->getAlignment(S.Context);
2473 if (Align > NewAlign)
2474 NewAlign = Align;
2475 }
2476
2477 if (OldAlignasAttr && NewAlignasAttr && OldAlign != NewAlign) {
2478 // Both declarations have 'alignas' attributes. We require them to match.
2479 // C++11 [dcl.align]p6 and C11 6.7.5/7 both come close to saying this, but
2480 // fall short. (If two declarations both have alignas, they must both match
2481 // every definition, and so must match each other if there is a definition.)
2482
2483 // If either declaration only contains 'alignas(0)' specifiers, then it
2484 // specifies the natural alignment for the type.
2485 if (OldAlign == 0 || NewAlign == 0) {
2486 QualType Ty;
2487 if (ValueDecl *VD = dyn_cast<ValueDecl>(New))
2488 Ty = VD->getType();
2489 else
2490 Ty = S.Context.getTagDeclType(cast<TagDecl>(New));
2491
2492 if (OldAlign == 0)
2493 OldAlign = S.Context.getTypeAlign(Ty);
2494 if (NewAlign == 0)
2495 NewAlign = S.Context.getTypeAlign(Ty);
2496 }
2497
2498 if (OldAlign != NewAlign) {
2499 S.Diag(NewAlignasAttr->getLocation(), diag::err_alignas_mismatch)
2500 << (unsigned)S.Context.toCharUnitsFromBits(OldAlign).getQuantity()
2501 << (unsigned)S.Context.toCharUnitsFromBits(NewAlign).getQuantity();
2502 S.Diag(OldAlignasAttr->getLocation(), diag::note_previous_declaration);
2503 }
2504 }
2505
2506 if (OldAlignasAttr && !NewAlignasAttr && isAttributeTargetADefinition(New)) {
2507 // C++11 [dcl.align]p6:
2508 // if any declaration of an entity has an alignment-specifier,
2509 // every defining declaration of that entity shall specify an
2510 // equivalent alignment.
2511 // C11 6.7.5/7:
2512 // If the definition of an object does not have an alignment
2513 // specifier, any other declaration of that object shall also
2514 // have no alignment specifier.
2515 S.Diag(New->getLocation(), diag::err_alignas_missing_on_definition)
2516 << OldAlignasAttr;
2517 S.Diag(OldAlignasAttr->getLocation(), diag::note_alignas_on_declaration)
2518 << OldAlignasAttr;
2519 }
2520
2521 bool AnyAdded = false;
2522
2523 // Ensure we have an attribute representing the strictest alignment.
2524 if (OldAlign > NewAlign) {
2525 AlignedAttr *Clone = OldStrictestAlignAttr->clone(S.Context);
2526 Clone->setInherited(true);
2527 New->addAttr(Clone);
2528 AnyAdded = true;
2529 }
2530
2531 // Ensure we have an alignas attribute if the old declaration had one.
2532 if (OldAlignasAttr && !NewAlignasAttr &&
2533 !(AnyAdded && OldStrictestAlignAttr->isAlignas())) {
2534 AlignedAttr *Clone = OldAlignasAttr->clone(S.Context);
2535 Clone->setInherited(true);
2536 New->addAttr(Clone);
2537 AnyAdded = true;
2538 }
2539
2540 return AnyAdded;
2541}
2542
2543static bool mergeDeclAttribute(Sema &S, NamedDecl *D,
2544 const InheritableAttr *Attr,
2545 Sema::AvailabilityMergeKind AMK) {
2546 // This function copies an attribute Attr from a previous declaration to the
2547 // new declaration D if the new declaration doesn't itself have that attribute
2548 // yet or if that attribute allows duplicates.
2549 // If you're adding a new attribute that requires logic different from
2550 // "use explicit attribute on decl if present, else use attribute from
2551 // previous decl", for example if the attribute needs to be consistent
2552 // between redeclarations, you need to call a custom merge function here.
2553 InheritableAttr *NewAttr = nullptr;
2554 if (const auto *AA = dyn_cast<AvailabilityAttr>(Attr))
2555 NewAttr = S.mergeAvailabilityAttr(
2556 D, *AA, AA->getPlatform(), AA->isImplicit(), AA->getIntroduced(),
2557 AA->getDeprecated(), AA->getObsoleted(), AA->getUnavailable(),
2558 AA->getMessage(), AA->getStrict(), AA->getReplacement(), AMK,
2559 AA->getPriority());
2560 else if (const auto *VA = dyn_cast<VisibilityAttr>(Attr))
2561 NewAttr = S.mergeVisibilityAttr(D, *VA, VA->getVisibility());
2562 else if (const auto *VA = dyn_cast<TypeVisibilityAttr>(Attr))
2563 NewAttr = S.mergeTypeVisibilityAttr(D, *VA, VA->getVisibility());
2564 else if (const auto *ImportA = dyn_cast<DLLImportAttr>(Attr))
2565 NewAttr = S.mergeDLLImportAttr(D, *ImportA);
2566 else if (const auto *ExportA = dyn_cast<DLLExportAttr>(Attr))
2567 NewAttr = S.mergeDLLExportAttr(D, *ExportA);
2568 else if (const auto *FA = dyn_cast<FormatAttr>(Attr))
2569 NewAttr = S.mergeFormatAttr(D, *FA, FA->getType(), FA->getFormatIdx(),
2570 FA->getFirstArg());
2571 else if (const auto *SA = dyn_cast<SectionAttr>(Attr))
2572 NewAttr = S.mergeSectionAttr(D, *SA, SA->getName());
2573 else if (const auto *CSA = dyn_cast<CodeSegAttr>(Attr))
2574 NewAttr = S.mergeCodeSegAttr(D, *CSA, CSA->getName());
2575 else if (const auto *IA = dyn_cast<MSInheritanceAttr>(Attr))
2576 NewAttr = S.mergeMSInheritanceAttr(D, *IA, IA->getBestCase(),
2577 IA->getInheritanceModel());
2578 else if (const auto *AA = dyn_cast<AlwaysInlineAttr>(Attr))
2579 NewAttr = S.mergeAlwaysInlineAttr(D, *AA,
2580 &S.Context.Idents.get(AA->getSpelling()));
2581 else if (S.getLangOpts().CUDA && isa<FunctionDecl>(D) &&
2582 (isa<CUDAHostAttr>(Attr) || isa<CUDADeviceAttr>(Attr) ||
2583 isa<CUDAGlobalAttr>(Attr))) {
2584 // CUDA target attributes are part of function signature for
2585 // overloading purposes and must not be merged.
2586 return false;
2587 } else if (const auto *MA = dyn_cast<MinSizeAttr>(Attr))
2588 NewAttr = S.mergeMinSizeAttr(D, *MA);
2589 else if (const auto *SNA = dyn_cast<SwiftNameAttr>(Attr))
2590 NewAttr = S.mergeSwiftNameAttr(D, *SNA, SNA->getName());
2591 else if (const auto *OA = dyn_cast<OptimizeNoneAttr>(Attr))
2592 NewAttr = S.mergeOptimizeNoneAttr(D, *OA);
2593 else if (const auto *InternalLinkageA = dyn_cast<InternalLinkageAttr>(Attr))
2594 NewAttr = S.mergeInternalLinkageAttr(D, *InternalLinkageA);
2595 else if (const auto *CommonA = dyn_cast<CommonAttr>(Attr))
2596 NewAttr = S.mergeCommonAttr(D, *CommonA);
2597 else if (isa<AlignedAttr>(Attr))
2598 // AlignedAttrs are handled separately, because we need to handle all
2599 // such attributes on a declaration at the same time.
2600 NewAttr = nullptr;
2601 else if ((isa<DeprecatedAttr>(Attr) || isa<UnavailableAttr>(Attr)) &&
2602 (AMK == Sema::AMK_Override ||
2603 AMK == Sema::AMK_ProtocolImplementation))
2604 NewAttr = nullptr;
2605 else if (const auto *UA = dyn_cast<UuidAttr>(Attr))
2606 NewAttr = S.mergeUuidAttr(D, *UA, UA->getGuid(), UA->getGuidDecl());
2607 else if (const auto *SLHA = dyn_cast<SpeculativeLoadHardeningAttr>(Attr))
2608 NewAttr = S.mergeSpeculativeLoadHardeningAttr(D, *SLHA);
2609 else if (const auto *SLHA = dyn_cast<NoSpeculativeLoadHardeningAttr>(Attr))
2610 NewAttr = S.mergeNoSpeculativeLoadHardeningAttr(D, *SLHA);
2611 else if (const auto *IMA = dyn_cast<WebAssemblyImportModuleAttr>(Attr))
2612 NewAttr = S.mergeImportModuleAttr(D, *IMA);
2613 else if (const auto *INA = dyn_cast<WebAssemblyImportNameAttr>(Attr))
2614 NewAttr = S.mergeImportNameAttr(D, *INA);
2615 else if (const auto *TCBA = dyn_cast<EnforceTCBAttr>(Attr))
2616 NewAttr = S.mergeEnforceTCBAttr(D, *TCBA);
2617 else if (const auto *TCBLA = dyn_cast<EnforceTCBLeafAttr>(Attr))
2618 NewAttr = S.mergeEnforceTCBLeafAttr(D, *TCBLA);
2619 else if (Attr->shouldInheritEvenIfAlreadyPresent() || !DeclHasAttr(D, Attr))
2620 NewAttr = cast<InheritableAttr>(Attr->clone(S.Context));
2621
2622 if (NewAttr) {
2623 NewAttr->setInherited(true);
2624 D->addAttr(NewAttr);
2625 if (isa<MSInheritanceAttr>(NewAttr))
2626 S.Consumer.AssignInheritanceModel(cast<CXXRecordDecl>(D));
2627 return true;
2628 }
2629
2630 return false;
2631}
2632
2633static const NamedDecl *getDefinition(const Decl *D) {
2634 if (const TagDecl *TD = dyn_cast<TagDecl>(D))
2635 return TD->getDefinition();
2636 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
2637 const VarDecl *Def = VD->getDefinition();
2638 if (Def)
2639 return Def;
2640 return VD->getActingDefinition();
2641 }
2642 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
2643 const FunctionDecl *Def = nullptr;
2644 if (FD->isDefined(Def, true))
2645 return Def;
2646 }
2647 return nullptr;
2648}
2649
2650static bool hasAttribute(const Decl *D, attr::Kind Kind) {
2651 for (const auto *Attribute : D->attrs())
2652 if (Attribute->getKind() == Kind)
2653 return true;
2654 return false;
2655}
2656
2657/// checkNewAttributesAfterDef - If we already have a definition, check that
2658/// there are no new attributes in this declaration.
2659static void checkNewAttributesAfterDef(Sema &S, Decl *New, const Decl *Old) {
2660 if (!New->hasAttrs())
2661 return;
2662
2663 const NamedDecl *Def = getDefinition(Old);
2664 if (!Def || Def == New)
2665 return;
2666
2667 AttrVec &NewAttributes = New->getAttrs();
2668 for (unsigned I = 0, E = NewAttributes.size(); I != E;) {
2669 const Attr *NewAttribute = NewAttributes[I];
2670
2671 if (isa<AliasAttr>(NewAttribute) || isa<IFuncAttr>(NewAttribute)) {
2672 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(New)) {
2673 Sema::SkipBodyInfo SkipBody;
2674 S.CheckForFunctionRedefinition(FD, cast<FunctionDecl>(Def), &SkipBody);
2675
2676 // If we're skipping this definition, drop the "alias" attribute.
2677 if (SkipBody.ShouldSkip) {
2678 NewAttributes.erase(NewAttributes.begin() + I);
2679 --E;
2680 continue;
2681 }
2682 } else {
2683 VarDecl *VD = cast<VarDecl>(New);
2684 unsigned Diag = cast<VarDecl>(Def)->isThisDeclarationADefinition() ==
2685 VarDecl::TentativeDefinition
2686 ? diag::err_alias_after_tentative
2687 : diag::err_redefinition;
2688 S.Diag(VD->getLocation(), Diag) << VD->getDeclName();
2689 if (Diag == diag::err_redefinition)
2690 S.notePreviousDefinition(Def, VD->getLocation());
2691 else
2692 S.Diag(Def->getLocation(), diag::note_previous_definition);
2693 VD->setInvalidDecl();
2694 }
2695 ++I;
2696 continue;
2697 }
2698
2699 if (const VarDecl *VD = dyn_cast<VarDecl>(Def)) {
2700 // Tentative definitions are only interesting for the alias check above.
2701 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) {
2702 ++I;
2703 continue;
2704 }
2705 }
2706
2707 if (hasAttribute(Def, NewAttribute->getKind())) {
2708 ++I;
2709 continue; // regular attr merging will take care of validating this.
2710 }
2711
2712 if (isa<C11NoReturnAttr>(NewAttribute)) {
2713 // C's _Noreturn is allowed to be added to a function after it is defined.
2714 ++I;
2715 continue;
2716 } else if (isa<UuidAttr>(NewAttribute)) {
2717 // msvc will allow a subsequent definition to add an uuid to a class
2718 ++I;
2719 continue;
2720 } else if (const AlignedAttr *AA = dyn_cast<AlignedAttr>(NewAttribute)) {
2721 if (AA->isAlignas()) {
2722 // C++11 [dcl.align]p6:
2723 // if any declaration of an entity has an alignment-specifier,
2724 // every defining declaration of that entity shall specify an
2725 // equivalent alignment.
2726 // C11 6.7.5/7:
2727 // If the definition of an object does not have an alignment
2728 // specifier, any other declaration of that object shall also
2729 // have no alignment specifier.
2730 S.Diag(Def->getLocation(), diag::err_alignas_missing_on_definition)
2731 << AA;
2732 S.Diag(NewAttribute->getLocation(), diag::note_alignas_on_declaration)
2733 << AA;
2734 NewAttributes.erase(NewAttributes.begin() + I);
2735 --E;
2736 continue;
2737 }
2738 } else if (isa<LoaderUninitializedAttr>(NewAttribute)) {
2739 // If there is a C definition followed by a redeclaration with this
2740 // attribute then there are two different definitions. In C++, prefer the
2741 // standard diagnostics.
2742 if (!S.getLangOpts().CPlusPlus) {
2743 S.Diag(NewAttribute->getLocation(),
2744 diag::err_loader_uninitialized_redeclaration);
2745 S.Diag(Def->getLocation(), diag::note_previous_definition);
2746 NewAttributes.erase(NewAttributes.begin() + I);
2747 --E;
2748 continue;
2749 }
2750 } else if (isa<SelectAnyAttr>(NewAttribute) &&
2751 cast<VarDecl>(New)->isInline() &&
2752 !cast<VarDecl>(New)->isInlineSpecified()) {
2753 // Don't warn about applying selectany to implicitly inline variables.
2754 // Older compilers and language modes would require the use of selectany
2755 // to make such variables inline, and it would have no effect if we
2756 // honored it.
2757 ++I;
2758 continue;
2759 } else if (isa<OMPDeclareVariantAttr>(NewAttribute)) {
2760 // We allow to add OMP[Begin]DeclareVariantAttr to be added to
2761 // declarations after defintions.
2762 ++I;
2763 continue;
2764 }
2765
2766 S.Diag(NewAttribute->getLocation(),
2767 diag::warn_attribute_precede_definition);
2768 S.Diag(Def->getLocation(), diag::note_previous_definition);
2769 NewAttributes.erase(NewAttributes.begin() + I);
2770 --E;
2771 }
2772}
2773
2774static void diagnoseMissingConstinit(Sema &S, const VarDecl *InitDecl,
2775 const ConstInitAttr *CIAttr,
2776 bool AttrBeforeInit) {
2777 SourceLocation InsertLoc = InitDecl->getInnerLocStart();
2778
2779 // Figure out a good way to write this specifier on the old declaration.
2780 // FIXME: We should just use the spelling of CIAttr, but we don't preserve
2781 // enough of the attribute list spelling information to extract that without
2782 // heroics.
2783 std::string SuitableSpelling;
2784 if (S.getLangOpts().CPlusPlus20)
2785 SuitableSpelling = std::string(
2786 S.PP.getLastMacroWithSpelling(InsertLoc, {tok::kw_constinit}));
2787 if (SuitableSpelling.empty() && S.getLangOpts().CPlusPlus11)
2788 SuitableSpelling = std::string(S.PP.getLastMacroWithSpelling(
2789 InsertLoc, {tok::l_square, tok::l_square,
2790 S.PP.getIdentifierInfo("clang"), tok::coloncolon,
2791 S.PP.getIdentifierInfo("require_constant_initialization"),
2792 tok::r_square, tok::r_square}));
2793 if (SuitableSpelling.empty())
2794 SuitableSpelling = std::string(S.PP.getLastMacroWithSpelling(
2795 InsertLoc, {tok::kw___attribute, tok::l_paren, tok::r_paren,
2796 S.PP.getIdentifierInfo("require_constant_initialization"),
2797 tok::r_paren, tok::r_paren}));
2798 if (SuitableSpelling.empty() && S.getLangOpts().CPlusPlus20)
2799 SuitableSpelling = "constinit";
2800 if (SuitableSpelling.empty() && S.getLangOpts().CPlusPlus11)
2801 SuitableSpelling = "[[clang::require_constant_initialization]]";
2802 if (SuitableSpelling.empty())
2803 SuitableSpelling = "__attribute__((require_constant_initialization))";
2804 SuitableSpelling += " ";
2805
2806 if (AttrBeforeInit) {
2807 // extern constinit int a;
2808 // int a = 0; // error (missing 'constinit'), accepted as extension
2809 assert(CIAttr->isConstinit() && "should not diagnose this for attribute")((CIAttr->isConstinit() && "should not diagnose this for attribute"
) ? static_cast<void> (0) : __assert_fail ("CIAttr->isConstinit() && \"should not diagnose this for attribute\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 2809, __PRETTY_FUNCTION__))
;
2810 S.Diag(InitDecl->getLocation(), diag::ext_constinit_missing)
2811 << InitDecl << FixItHint::CreateInsertion(InsertLoc, SuitableSpelling);
2812 S.Diag(CIAttr->getLocation(), diag::note_constinit_specified_here);
2813 } else {
2814 // int a = 0;
2815 // constinit extern int a; // error (missing 'constinit')
2816 S.Diag(CIAttr->getLocation(),
2817 CIAttr->isConstinit() ? diag::err_constinit_added_too_late
2818 : diag::warn_require_const_init_added_too_late)
2819 << FixItHint::CreateRemoval(SourceRange(CIAttr->getLocation()));
2820 S.Diag(InitDecl->getLocation(), diag::note_constinit_missing_here)
2821 << CIAttr->isConstinit()
2822 << FixItHint::CreateInsertion(InsertLoc, SuitableSpelling);
2823 }
2824}
2825
2826/// mergeDeclAttributes - Copy attributes from the Old decl to the New one.
2827void Sema::mergeDeclAttributes(NamedDecl *New, Decl *Old,
2828 AvailabilityMergeKind AMK) {
2829 if (UsedAttr *OldAttr = Old->getMostRecentDecl()->getAttr<UsedAttr>()) {
2830 UsedAttr *NewAttr = OldAttr->clone(Context);
2831 NewAttr->setInherited(true);
2832 New->addAttr(NewAttr);
2833 }
2834
2835 if (!Old->hasAttrs() && !New->hasAttrs())
2836 return;
2837
2838 // [dcl.constinit]p1:
2839 // If the [constinit] specifier is applied to any declaration of a
2840 // variable, it shall be applied to the initializing declaration.
2841 const auto *OldConstInit = Old->getAttr<ConstInitAttr>();
2842 const auto *NewConstInit = New->getAttr<ConstInitAttr>();
2843 if (bool(OldConstInit) != bool(NewConstInit)) {
2844 const auto *OldVD = cast<VarDecl>(Old);
2845 auto *NewVD = cast<VarDecl>(New);
2846
2847 // Find the initializing declaration. Note that we might not have linked
2848 // the new declaration into the redeclaration chain yet.
2849 const VarDecl *InitDecl = OldVD->getInitializingDeclaration();
2850 if (!InitDecl &&
2851 (NewVD->hasInit() || NewVD->isThisDeclarationADefinition()))
2852 InitDecl = NewVD;
2853
2854 if (InitDecl == NewVD) {
2855 // This is the initializing declaration. If it would inherit 'constinit',
2856 // that's ill-formed. (Note that we do not apply this to the attribute
2857 // form).
2858 if (OldConstInit && OldConstInit->isConstinit())
2859 diagnoseMissingConstinit(*this, NewVD, OldConstInit,
2860 /*AttrBeforeInit=*/true);
2861 } else if (NewConstInit) {
2862 // This is the first time we've been told that this declaration should
2863 // have a constant initializer. If we already saw the initializing
2864 // declaration, this is too late.
2865 if (InitDecl && InitDecl != NewVD) {
2866 diagnoseMissingConstinit(*this, InitDecl, NewConstInit,
2867 /*AttrBeforeInit=*/false);
2868 NewVD->dropAttr<ConstInitAttr>();
2869 }
2870 }
2871 }
2872
2873 // Attributes declared post-definition are currently ignored.
2874 checkNewAttributesAfterDef(*this, New, Old);
2875
2876 if (AsmLabelAttr *NewA = New->getAttr<AsmLabelAttr>()) {
2877 if (AsmLabelAttr *OldA = Old->getAttr<AsmLabelAttr>()) {
2878 if (!OldA->isEquivalent(NewA)) {
2879 // This redeclaration changes __asm__ label.
2880 Diag(New->getLocation(), diag::err_different_asm_label);
2881 Diag(OldA->getLocation(), diag::note_previous_declaration);
2882 }
2883 } else if (Old->isUsed()) {
2884 // This redeclaration adds an __asm__ label to a declaration that has
2885 // already been ODR-used.
2886 Diag(New->getLocation(), diag::err_late_asm_label_name)
2887 << isa<FunctionDecl>(Old) << New->getAttr<AsmLabelAttr>()->getRange();
2888 }
2889 }
2890
2891 // Re-declaration cannot add abi_tag's.
2892 if (const auto *NewAbiTagAttr = New->getAttr<AbiTagAttr>()) {
2893 if (const auto *OldAbiTagAttr = Old->getAttr<AbiTagAttr>()) {
2894 for (const auto &NewTag : NewAbiTagAttr->tags()) {
2895 if (std::find(OldAbiTagAttr->tags_begin(), OldAbiTagAttr->tags_end(),
2896 NewTag) == OldAbiTagAttr->tags_end()) {
2897 Diag(NewAbiTagAttr->getLocation(),
2898 diag::err_new_abi_tag_on_redeclaration)
2899 << NewTag;
2900 Diag(OldAbiTagAttr->getLocation(), diag::note_previous_declaration);
2901 }
2902 }
2903 } else {
2904 Diag(NewAbiTagAttr->getLocation(), diag::err_abi_tag_on_redeclaration);
2905 Diag(Old->getLocation(), diag::note_previous_declaration);
2906 }
2907 }
2908
2909 // This redeclaration adds a section attribute.
2910 if (New->hasAttr<SectionAttr>() && !Old->hasAttr<SectionAttr>()) {
2911 if (auto *VD = dyn_cast<VarDecl>(New)) {
2912 if (VD->isThisDeclarationADefinition() == VarDecl::DeclarationOnly) {
2913 Diag(New->getLocation(), diag::warn_attribute_section_on_redeclaration);
2914 Diag(Old->getLocation(), diag::note_previous_declaration);
2915 }
2916 }
2917 }
2918
2919 // Redeclaration adds code-seg attribute.
2920 const auto *NewCSA = New->getAttr<CodeSegAttr>();
2921 if (NewCSA && !Old->hasAttr<CodeSegAttr>() &&
2922 !NewCSA->isImplicit() && isa<CXXMethodDecl>(New)) {
2923 Diag(New->getLocation(), diag::warn_mismatched_section)
2924 << 0 /*codeseg*/;
2925 Diag(Old->getLocation(), diag::note_previous_declaration);
2926 }
2927
2928 if (!Old->hasAttrs())
2929 return;
2930
2931 bool foundAny = New->hasAttrs();
2932
2933 // Ensure that any moving of objects within the allocated map is done before
2934 // we process them.
2935 if (!foundAny) New->setAttrs(AttrVec());
2936
2937 for (auto *I : Old->specific_attrs<InheritableAttr>()) {
2938 // Ignore deprecated/unavailable/availability attributes if requested.
2939 AvailabilityMergeKind LocalAMK = AMK_None;
2940 if (isa<DeprecatedAttr>(I) ||
2941 isa<UnavailableAttr>(I) ||
2942 isa<AvailabilityAttr>(I)) {
2943 switch (AMK) {
2944 case AMK_None:
2945 continue;
2946
2947 case AMK_Redeclaration:
2948 case AMK_Override:
2949 case AMK_ProtocolImplementation:
2950 LocalAMK = AMK;
2951 break;
2952 }
2953 }
2954
2955 // Already handled.
2956 if (isa<UsedAttr>(I))
2957 continue;
2958
2959 if (mergeDeclAttribute(*this, New, I, LocalAMK))
2960 foundAny = true;
2961 }
2962
2963 if (mergeAlignedAttrs(*this, New, Old))
2964 foundAny = true;
2965
2966 if (!foundAny) New->dropAttrs();
2967}
2968
2969/// mergeParamDeclAttributes - Copy attributes from the old parameter
2970/// to the new one.
2971static void mergeParamDeclAttributes(ParmVarDecl *newDecl,
2972 const ParmVarDecl *oldDecl,
2973 Sema &S) {
2974 // C++11 [dcl.attr.depend]p2:
2975 // The first declaration of a function shall specify the
2976 // carries_dependency attribute for its declarator-id if any declaration
2977 // of the function specifies the carries_dependency attribute.
2978 const CarriesDependencyAttr *CDA = newDecl->getAttr<CarriesDependencyAttr>();
2979 if (CDA && !oldDecl->hasAttr<CarriesDependencyAttr>()) {
2980 S.Diag(CDA->getLocation(),
2981 diag::err_carries_dependency_missing_on_first_decl) << 1/*Param*/;
2982 // Find the first declaration of the parameter.
2983 // FIXME: Should we build redeclaration chains for function parameters?
2984 const FunctionDecl *FirstFD =
2985 cast<FunctionDecl>(oldDecl->getDeclContext())->getFirstDecl();
2986 const ParmVarDecl *FirstVD =
2987 FirstFD->getParamDecl(oldDecl->getFunctionScopeIndex());
2988 S.Diag(FirstVD->getLocation(),
2989 diag::note_carries_dependency_missing_first_decl) << 1/*Param*/;
2990 }
2991
2992 if (!oldDecl->hasAttrs())
2993 return;
2994
2995 bool foundAny = newDecl->hasAttrs();
2996
2997 // Ensure that any moving of objects within the allocated map is
2998 // done before we process them.
2999 if (!foundAny) newDecl->setAttrs(AttrVec());
3000
3001 for (const auto *I : oldDecl->specific_attrs<InheritableParamAttr>()) {
3002 if (!DeclHasAttr(newDecl, I)) {
3003 InheritableAttr *newAttr =
3004 cast<InheritableParamAttr>(I->clone(S.Context));
3005 newAttr->setInherited(true);
3006 newDecl->addAttr(newAttr);
3007 foundAny = true;
3008 }
3009 }
3010
3011 if (!foundAny) newDecl->dropAttrs();
3012}
3013
3014static void mergeParamDeclTypes(ParmVarDecl *NewParam,
3015 const ParmVarDecl *OldParam,
3016 Sema &S) {
3017 if (auto Oldnullability = OldParam->getType()->getNullability(S.Context)) {
3018 if (auto Newnullability = NewParam->getType()->getNullability(S.Context)) {
3019 if (*Oldnullability != *Newnullability) {
3020 S.Diag(NewParam->getLocation(), diag::warn_mismatched_nullability_attr)
3021 << DiagNullabilityKind(
3022 *Newnullability,
3023 ((NewParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
3024 != 0))
3025 << DiagNullabilityKind(
3026 *Oldnullability,
3027 ((OldParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
3028 != 0));
3029 S.Diag(OldParam->getLocation(), diag::note_previous_declaration);
3030 }
3031 } else {
3032 QualType NewT = NewParam->getType();
3033 NewT = S.Context.getAttributedType(
3034 AttributedType::getNullabilityAttrKind(*Oldnullability),
3035 NewT, NewT);
3036 NewParam->setType(NewT);
3037 }
3038 }
3039}
3040
3041namespace {
3042
3043/// Used in MergeFunctionDecl to keep track of function parameters in
3044/// C.
3045struct GNUCompatibleParamWarning {
3046 ParmVarDecl *OldParm;
3047 ParmVarDecl *NewParm;
3048 QualType PromotedType;
3049};
3050
3051} // end anonymous namespace
3052
3053// Determine whether the previous declaration was a definition, implicit
3054// declaration, or a declaration.
3055template <typename T>
3056static std::pair<diag::kind, SourceLocation>
3057getNoteDiagForInvalidRedeclaration(const T *Old, const T *New) {
3058 diag::kind PrevDiag;
3059 SourceLocation OldLocation = Old->getLocation();
3060 if (Old->isThisDeclarationADefinition())
3061 PrevDiag = diag::note_previous_definition;
3062 else if (Old->isImplicit()) {
3063 PrevDiag = diag::note_previous_implicit_declaration;
3064 if (OldLocation.isInvalid())
3065 OldLocation = New->getLocation();
3066 } else
3067 PrevDiag = diag::note_previous_declaration;
3068 return std::make_pair(PrevDiag, OldLocation);
3069}
3070
3071/// canRedefineFunction - checks if a function can be redefined. Currently,
3072/// only extern inline functions can be redefined, and even then only in
3073/// GNU89 mode.
3074static bool canRedefineFunction(const FunctionDecl *FD,
3075 const LangOptions& LangOpts) {
3076 return ((FD->hasAttr<GNUInlineAttr>() || LangOpts.GNUInline) &&
3077 !LangOpts.CPlusPlus &&
3078 FD->isInlineSpecified() &&
3079 FD->getStorageClass() == SC_Extern);
3080}
3081
3082const AttributedType *Sema::getCallingConvAttributedType(QualType T) const {
3083 const AttributedType *AT = T->getAs<AttributedType>();
3084 while (AT && !AT->isCallingConv())
3085 AT = AT->getModifiedType()->getAs<AttributedType>();
3086 return AT;
3087}
3088
3089template <typename T>
3090static bool haveIncompatibleLanguageLinkages(const T *Old, const T *New) {
3091 const DeclContext *DC = Old->getDeclContext();
3092 if (DC->isRecord())
3093 return false;
3094
3095 LanguageLinkage OldLinkage = Old->getLanguageLinkage();
3096 if (OldLinkage == CXXLanguageLinkage && New->isInExternCContext())
3097 return true;
3098 if (OldLinkage == CLanguageLinkage && New->isInExternCXXContext())
3099 return true;
3100 return false;
3101}
3102
3103template<typename T> static bool isExternC(T *D) { return D->isExternC(); }
3104static bool isExternC(VarTemplateDecl *) { return false; }
3105
3106/// Check whether a redeclaration of an entity introduced by a
3107/// using-declaration is valid, given that we know it's not an overload
3108/// (nor a hidden tag declaration).
3109template<typename ExpectedDecl>
3110static bool checkUsingShadowRedecl(Sema &S, UsingShadowDecl *OldS,
3111 ExpectedDecl *New) {
3112 // C++11 [basic.scope.declarative]p4:
3113 // Given a set of declarations in a single declarative region, each of
3114 // which specifies the same unqualified name,
3115 // -- they shall all refer to the same entity, or all refer to functions
3116 // and function templates; or
3117 // -- exactly one declaration shall declare a class name or enumeration
3118 // name that is not a typedef name and the other declarations shall all
3119 // refer to the same variable or enumerator, or all refer to functions
3120 // and function templates; in this case the class name or enumeration
3121 // name is hidden (3.3.10).
3122
3123 // C++11 [namespace.udecl]p14:
3124 // If a function declaration in namespace scope or block scope has the
3125 // same name and the same parameter-type-list as a function introduced
3126 // by a using-declaration, and the declarations do not declare the same
3127 // function, the program is ill-formed.
3128
3129 auto *Old = dyn_cast<ExpectedDecl>(OldS->getTargetDecl());
3130 if (Old &&
3131 !Old->getDeclContext()->getRedeclContext()->Equals(
3132 New->getDeclContext()->getRedeclContext()) &&
3133 !(isExternC(Old) && isExternC(New)))
3134 Old = nullptr;
3135
3136 if (!Old) {
3137 S.Diag(New->getLocation(), diag::err_using_decl_conflict_reverse);
3138 S.Diag(OldS->getTargetDecl()->getLocation(), diag::note_using_decl_target);
3139 S.Diag(OldS->getUsingDecl()->getLocation(), diag::note_using_decl) << 0;
3140 return true;
3141 }
3142 return false;
3143}
3144
3145static bool hasIdenticalPassObjectSizeAttrs(const FunctionDecl *A,
3146 const FunctionDecl *B) {
3147 assert(A->getNumParams() == B->getNumParams())((A->getNumParams() == B->getNumParams()) ? static_cast
<void> (0) : __assert_fail ("A->getNumParams() == B->getNumParams()"
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 3147, __PRETTY_FUNCTION__))
;
3148
3149 auto AttrEq = [](const ParmVarDecl *A, const ParmVarDecl *B) {
3150 const auto *AttrA = A->getAttr<PassObjectSizeAttr>();
3151 const auto *AttrB = B->getAttr<PassObjectSizeAttr>();
3152 if (AttrA == AttrB)
3153 return true;
3154 return AttrA && AttrB && AttrA->getType() == AttrB->getType() &&
3155 AttrA->isDynamic() == AttrB->isDynamic();
3156 };
3157
3158 return std::equal(A->param_begin(), A->param_end(), B->param_begin(), AttrEq);
3159}
3160
3161/// If necessary, adjust the semantic declaration context for a qualified
3162/// declaration to name the correct inline namespace within the qualifier.
3163static void adjustDeclContextForDeclaratorDecl(DeclaratorDecl *NewD,
3164 DeclaratorDecl *OldD) {
3165 // The only case where we need to update the DeclContext is when
3166 // redeclaration lookup for a qualified name finds a declaration
3167 // in an inline namespace within the context named by the qualifier:
3168 //
3169 // inline namespace N { int f(); }
3170 // int ::f(); // Sema DC needs adjusting from :: to N::.
3171 //
3172 // For unqualified declarations, the semantic context *can* change
3173 // along the redeclaration chain (for local extern declarations,
3174 // extern "C" declarations, and friend declarations in particular).
3175 if (!NewD->getQualifier())
3176 return;
3177
3178 // NewD is probably already in the right context.
3179 auto *NamedDC = NewD->getDeclContext()->getRedeclContext();
3180 auto *SemaDC = OldD->getDeclContext()->getRedeclContext();
3181 if (NamedDC->Equals(SemaDC))
3182 return;
3183
3184 assert((NamedDC->InEnclosingNamespaceSetOf(SemaDC) ||(((NamedDC->InEnclosingNamespaceSetOf(SemaDC) || NewD->
isInvalidDecl() || OldD->isInvalidDecl()) && "unexpected context for redeclaration"
) ? static_cast<void> (0) : __assert_fail ("(NamedDC->InEnclosingNamespaceSetOf(SemaDC) || NewD->isInvalidDecl() || OldD->isInvalidDecl()) && \"unexpected context for redeclaration\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 3186, __PRETTY_FUNCTION__))
3185 NewD->isInvalidDecl() || OldD->isInvalidDecl()) &&(((NamedDC->InEnclosingNamespaceSetOf(SemaDC) || NewD->
isInvalidDecl() || OldD->isInvalidDecl()) && "unexpected context for redeclaration"
) ? static_cast<void> (0) : __assert_fail ("(NamedDC->InEnclosingNamespaceSetOf(SemaDC) || NewD->isInvalidDecl() || OldD->isInvalidDecl()) && \"unexpected context for redeclaration\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 3186, __PRETTY_FUNCTION__))
3186 "unexpected context for redeclaration")(((NamedDC->InEnclosingNamespaceSetOf(SemaDC) || NewD->
isInvalidDecl() || OldD->isInvalidDecl()) && "unexpected context for redeclaration"
) ? static_cast<void> (0) : __assert_fail ("(NamedDC->InEnclosingNamespaceSetOf(SemaDC) || NewD->isInvalidDecl() || OldD->isInvalidDecl()) && \"unexpected context for redeclaration\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 3186, __PRETTY_FUNCTION__))
;
3187
3188 auto *LexDC = NewD->getLexicalDeclContext();
3189 auto FixSemaDC = [=](NamedDecl *D) {
3190 if (!D)
3191 return;
3192 D->setDeclContext(SemaDC);
3193 D->setLexicalDeclContext(LexDC);
3194 };
3195
3196 FixSemaDC(NewD);
3197 if (auto *FD = dyn_cast<FunctionDecl>(NewD))
3198 FixSemaDC(FD->getDescribedFunctionTemplate());
3199 else if (auto *VD = dyn_cast<VarDecl>(NewD))
3200 FixSemaDC(VD->getDescribedVarTemplate());
3201}
3202
3203/// MergeFunctionDecl - We just parsed a function 'New' from
3204/// declarator D which has the same name and scope as a previous
3205/// declaration 'Old'. Figure out how to resolve this situation,
3206/// merging decls or emitting diagnostics as appropriate.
3207///
3208/// In C++, New and Old must be declarations that are not
3209/// overloaded. Use IsOverload to determine whether New and Old are
3210/// overloaded, and to select the Old declaration that New should be
3211/// merged with.
3212///
3213/// Returns true if there was an error, false otherwise.
3214bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD,
3215 Scope *S, bool MergeTypeWithOld) {
3216 // Verify the old decl was also a function.
3217 FunctionDecl *Old = OldD->getAsFunction();
3218 if (!Old) {
3219 if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(OldD)) {
3220 if (New->getFriendObjectKind()) {
3221 Diag(New->getLocation(), diag::err_using_decl_friend);
3222 Diag(Shadow->getTargetDecl()->getLocation(),
3223 diag::note_using_decl_target);
3224 Diag(Shadow->getUsingDecl()->getLocation(),
3225 diag::note_using_decl) << 0;
3226 return true;
3227 }
3228
3229 // Check whether the two declarations might declare the same function.
3230 if (checkUsingShadowRedecl<FunctionDecl>(*this, Shadow, New))
3231 return true;
3232 OldD = Old = cast<FunctionDecl>(Shadow->getTargetDecl());
3233 } else {
3234 Diag(New->getLocation(), diag::err_redefinition_different_kind)
3235 << New->getDeclName();
3236 notePreviousDefinition(OldD, New->getLocation());
3237 return true;
3238 }
3239 }
3240
3241 // If the old declaration was found in an inline namespace and the new
3242 // declaration was qualified, update the DeclContext to match.
3243 adjustDeclContextForDeclaratorDecl(New, Old);
3244
3245 // If the old declaration is invalid, just give up here.
3246 if (Old->isInvalidDecl())
3247 return true;
3248
3249 // Disallow redeclaration of some builtins.
3250 if (!getASTContext().canBuiltinBeRedeclared(Old)) {
3251 Diag(New->getLocation(), diag::err_builtin_redeclare) << Old->getDeclName();
3252 Diag(Old->getLocation(), diag::note_previous_builtin_declaration)
3253 << Old << Old->getType();
3254 return true;
3255 }
3256
3257 diag::kind PrevDiag;
3258 SourceLocation OldLocation;
3259 std::tie(PrevDiag, OldLocation) =
3260 getNoteDiagForInvalidRedeclaration(Old, New);
3261
3262 // Don't complain about this if we're in GNU89 mode and the old function
3263 // is an extern inline function.
3264 // Don't complain about specializations. They are not supposed to have
3265 // storage classes.
3266 if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) &&
3267 New->getStorageClass() == SC_Static &&
3268 Old->hasExternalFormalLinkage() &&
3269 !New->getTemplateSpecializationInfo() &&
3270 !canRedefineFunction(Old, getLangOpts())) {
3271 if (getLangOpts().MicrosoftExt) {
3272 Diag(New->getLocation(), diag::ext_static_non_static) << New;
3273 Diag(OldLocation, PrevDiag);
3274 } else {
3275 Diag(New->getLocation(), diag::err_static_non_static) << New;
3276 Diag(OldLocation, PrevDiag);
3277 return true;
3278 }
3279 }
3280
3281 if (New->hasAttr<InternalLinkageAttr>() &&
3282 !Old->hasAttr<InternalLinkageAttr>()) {
3283 Diag(New->getLocation(), diag::err_internal_linkage_redeclaration)
3284 << New->getDeclName();
3285 notePreviousDefinition(Old, New->getLocation());
3286 New->dropAttr<InternalLinkageAttr>();
3287 }
3288
3289 if (CheckRedeclarationModuleOwnership(New, Old))
3290 return true;
3291
3292 if (!getLangOpts().CPlusPlus) {
3293 bool OldOvl = Old->hasAttr<OverloadableAttr>();
3294 if (OldOvl != New->hasAttr<OverloadableAttr>() && !Old->isImplicit()) {
3295 Diag(New->getLocation(), diag::err_attribute_overloadable_mismatch)
3296 << New << OldOvl;
3297
3298 // Try our best to find a decl that actually has the overloadable
3299 // attribute for the note. In most cases (e.g. programs with only one
3300 // broken declaration/definition), this won't matter.
3301 //
3302 // FIXME: We could do this if we juggled some extra state in
3303 // OverloadableAttr, rather than just removing it.
3304 const Decl *DiagOld = Old;
3305 if (OldOvl) {
3306 auto OldIter = llvm::find_if(Old->redecls(), [](const Decl *D) {
3307 const auto *A = D->getAttr<OverloadableAttr>();
3308 return A && !A->isImplicit();
3309 });
3310 // If we've implicitly added *all* of the overloadable attrs to this
3311 // chain, emitting a "previous redecl" note is pointless.
3312 DiagOld = OldIter == Old->redecls_end() ? nullptr : *OldIter;
3313 }
3314
3315 if (DiagOld)
3316 Diag(DiagOld->getLocation(),
3317 diag::note_attribute_overloadable_prev_overload)
3318 << OldOvl;
3319
3320 if (OldOvl)
3321 New->addAttr(OverloadableAttr::CreateImplicit(Context));
3322 else
3323 New->dropAttr<OverloadableAttr>();
3324 }
3325 }
3326
3327 // If a function is first declared with a calling convention, but is later
3328 // declared or defined without one, all following decls assume the calling
3329 // convention of the first.
3330 //
3331 // It's OK if a function is first declared without a calling convention,
3332 // but is later declared or defined with the default calling convention.
3333 //
3334 // To test if either decl has an explicit calling convention, we look for
3335 // AttributedType sugar nodes on the type as written. If they are missing or
3336 // were canonicalized away, we assume the calling convention was implicit.
3337 //
3338 // Note also that we DO NOT return at this point, because we still have
3339 // other tests to run.
3340 QualType OldQType = Context.getCanonicalType(Old->getType());
3341 QualType NewQType = Context.getCanonicalType(New->getType());
3342 const FunctionType *OldType = cast<FunctionType>(OldQType);
3343 const FunctionType *NewType = cast<FunctionType>(NewQType);
3344 FunctionType::ExtInfo OldTypeInfo = OldType->getExtInfo();
3345 FunctionType::ExtInfo NewTypeInfo = NewType->getExtInfo();
3346 bool RequiresAdjustment = false;
3347
3348 if (OldTypeInfo.getCC() != NewTypeInfo.getCC()) {
3349 FunctionDecl *First = Old->getFirstDecl();
3350 const FunctionType *FT =
3351 First->getType().getCanonicalType()->castAs<FunctionType>();
3352 FunctionType::ExtInfo FI = FT->getExtInfo();
3353 bool NewCCExplicit = getCallingConvAttributedType(New->getType());
3354 if (!NewCCExplicit) {
3355 // Inherit the CC from the previous declaration if it was specified
3356 // there but not here.
3357 NewTypeInfo = NewTypeInfo.withCallingConv(OldTypeInfo.getCC());
3358 RequiresAdjustment = true;
3359 } else if (Old->getBuiltinID()) {
3360 // Builtin attribute isn't propagated to the new one yet at this point,
3361 // so we check if the old one is a builtin.
3362
3363 // Calling Conventions on a Builtin aren't really useful and setting a
3364 // default calling convention and cdecl'ing some builtin redeclarations is
3365 // common, so warn and ignore the calling convention on the redeclaration.
3366 Diag(New->getLocation(), diag::warn_cconv_unsupported)
3367 << FunctionType::getNameForCallConv(NewTypeInfo.getCC())
3368 << (int)CallingConventionIgnoredReason::BuiltinFunction;
3369 NewTypeInfo = NewTypeInfo.withCallingConv(OldTypeInfo.getCC());
3370 RequiresAdjustment = true;
3371 } else {
3372 // Calling conventions aren't compatible, so complain.
3373 bool FirstCCExplicit = getCallingConvAttributedType(First->getType());
3374 Diag(New->getLocation(), diag::err_cconv_change)
3375 << FunctionType::getNameForCallConv(NewTypeInfo.getCC())
3376 << !FirstCCExplicit
3377 << (!FirstCCExplicit ? "" :
3378 FunctionType::getNameForCallConv(FI.getCC()));
3379
3380 // Put the note on the first decl, since it is the one that matters.
3381 Diag(First->getLocation(), diag::note_previous_declaration);
3382 return true;
3383 }
3384 }
3385
3386 // FIXME: diagnose the other way around?
3387 if (OldTypeInfo.getNoReturn() && !NewTypeInfo.getNoReturn()) {
3388 NewTypeInfo = NewTypeInfo.withNoReturn(true);
3389 RequiresAdjustment = true;
3390 }
3391
3392 // Merge regparm attribute.
3393 if (OldTypeInfo.getHasRegParm() != NewTypeInfo.getHasRegParm() ||
3394 OldTypeInfo.getRegParm() != NewTypeInfo.getRegParm()) {
3395 if (NewTypeInfo.getHasRegParm()) {
3396 Diag(New->getLocation(), diag::err_regparm_mismatch)
3397 << NewType->getRegParmType()
3398 << OldType->getRegParmType();
3399 Diag(OldLocation, diag::note_previous_declaration);
3400 return true;
3401 }
3402
3403 NewTypeInfo = NewTypeInfo.withRegParm(OldTypeInfo.getRegParm());
3404 RequiresAdjustment = true;
3405 }
3406
3407 // Merge ns_returns_retained attribute.
3408 if (OldTypeInfo.getProducesResult() != NewTypeInfo.getProducesResult()) {
3409 if (NewTypeInfo.getProducesResult()) {
3410 Diag(New->getLocation(), diag::err_function_attribute_mismatch)
3411 << "'ns_returns_retained'";
3412 Diag(OldLocation, diag::note_previous_declaration);
3413 return true;
3414 }
3415
3416 NewTypeInfo = NewTypeInfo.withProducesResult(true);
3417 RequiresAdjustment = true;
3418 }
3419
3420 if (OldTypeInfo.getNoCallerSavedRegs() !=
3421 NewTypeInfo.getNoCallerSavedRegs()) {
3422 if (NewTypeInfo.getNoCallerSavedRegs()) {
3423 AnyX86NoCallerSavedRegistersAttr *Attr =
3424 New->getAttr<AnyX86NoCallerSavedRegistersAttr>();
3425 Diag(New->getLocation(), diag::err_function_attribute_mismatch) << Attr;
3426 Diag(OldLocation, diag::note_previous_declaration);
3427 return true;
3428 }
3429
3430 NewTypeInfo = NewTypeInfo.withNoCallerSavedRegs(true);
3431 RequiresAdjustment = true;
3432 }
3433
3434 if (RequiresAdjustment) {
3435 const FunctionType *AdjustedType = New->getType()->getAs<FunctionType>();
3436 AdjustedType = Context.adjustFunctionType(AdjustedType, NewTypeInfo);
3437 New->setType(QualType(AdjustedType, 0));
3438 NewQType = Context.getCanonicalType(New->getType());
3439 }
3440
3441 // If this redeclaration makes the function inline, we may need to add it to
3442 // UndefinedButUsed.
3443 if (!Old->isInlined() && New->isInlined() &&
3444 !New->hasAttr<GNUInlineAttr>() &&
3445 !getLangOpts().GNUInline &&
3446 Old->isUsed(false) &&
3447 !Old->isDefined() && !New->isThisDeclarationADefinition())
3448 UndefinedButUsed.insert(std::make_pair(Old->getCanonicalDecl(),
3449 SourceLocation()));
3450
3451 // If this redeclaration makes it newly gnu_inline, we don't want to warn
3452 // about it.
3453 if (New->hasAttr<GNUInlineAttr>() &&
3454 Old->isInlined() && !Old->hasAttr<GNUInlineAttr>()) {
3455 UndefinedButUsed.erase(Old->getCanonicalDecl());
3456 }
3457
3458 // If pass_object_size params don't match up perfectly, this isn't a valid
3459 // redeclaration.
3460 if (Old->getNumParams() > 0 && Old->getNumParams() == New->getNumParams() &&
3461 !hasIdenticalPassObjectSizeAttrs(Old, New)) {
3462 Diag(New->getLocation(), diag::err_different_pass_object_size_params)
3463 << New->getDeclName();
3464 Diag(OldLocation, PrevDiag) << Old << Old->getType();
3465 return true;
3466 }
3467
3468 if (getLangOpts().CPlusPlus) {
3469 // C++1z [over.load]p2
3470 // Certain function declarations cannot be overloaded:
3471 // -- Function declarations that differ only in the return type,
3472 // the exception specification, or both cannot be overloaded.
3473
3474 // Check the exception specifications match. This may recompute the type of
3475 // both Old and New if it resolved exception specifications, so grab the
3476 // types again after this. Because this updates the type, we do this before
3477 // any of the other checks below, which may update the "de facto" NewQType
3478 // but do not necessarily update the type of New.
3479 if (CheckEquivalentExceptionSpec(Old, New))
3480 return true;
3481 OldQType = Context.getCanonicalType(Old->getType());
3482 NewQType = Context.getCanonicalType(New->getType());
3483
3484 // Go back to the type source info to compare the declared return types,
3485 // per C++1y [dcl.type.auto]p13:
3486 // Redeclarations or specializations of a function or function template
3487 // with a declared return type that uses a placeholder type shall also
3488 // use that placeholder, not a deduced type.
3489 QualType OldDeclaredReturnType = Old->getDeclaredReturnType();
3490 QualType NewDeclaredReturnType = New->getDeclaredReturnType();
3491 if (!Context.hasSameType(OldDeclaredReturnType, NewDeclaredReturnType) &&
3492 canFullyTypeCheckRedeclaration(New, Old, NewDeclaredReturnType,
3493 OldDeclaredReturnType)) {
3494 QualType ResQT;
3495 if (NewDeclaredReturnType->isObjCObjectPointerType() &&
3496 OldDeclaredReturnType->isObjCObjectPointerType())
3497 // FIXME: This does the wrong thing for a deduced return type.
3498 ResQT = Context.mergeObjCGCQualifiers(NewQType, OldQType);
3499 if (ResQT.isNull()) {
3500 if (New->isCXXClassMember() && New->isOutOfLine())
3501 Diag(New->getLocation(), diag::err_member_def_does_not_match_ret_type)
3502 << New << New->getReturnTypeSourceRange();
3503 else
3504 Diag(New->getLocation(), diag::err_ovl_diff_return_type)
3505 << New->getReturnTypeSourceRange();
3506 Diag(OldLocation, PrevDiag) << Old << Old->getType()
3507 << Old->getReturnTypeSourceRange();
3508 return true;
3509 }
3510 else
3511 NewQType = ResQT;
3512 }
3513
3514 QualType OldReturnType = OldType->getReturnType();
3515 QualType NewReturnType = cast<FunctionType>(NewQType)->getReturnType();
3516 if (OldReturnType != NewReturnType) {
3517 // If this function has a deduced return type and has already been
3518 // defined, copy the deduced value from the old declaration.
3519 AutoType *OldAT = Old->getReturnType()->getContainedAutoType();
3520 if (OldAT && OldAT->isDeduced()) {
3521 New->setType(
3522 SubstAutoType(New->getType(),
3523 OldAT->isDependentType() ? Context.DependentTy
3524 : OldAT->getDeducedType()));
3525 NewQType = Context.getCanonicalType(
3526 SubstAutoType(NewQType,
3527 OldAT->isDependentType() ? Context.DependentTy
3528 : OldAT->getDeducedType()));
3529 }
3530 }
3531
3532 const CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
3533 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
3534 if (OldMethod && NewMethod) {
3535 // Preserve triviality.
3536 NewMethod->setTrivial(OldMethod->isTrivial());
3537
3538 // MSVC allows explicit template specialization at class scope:
3539 // 2 CXXMethodDecls referring to the same function will be injected.
3540 // We don't want a redeclaration error.
3541 bool IsClassScopeExplicitSpecialization =
3542 OldMethod->isFunctionTemplateSpecialization() &&
3543 NewMethod->isFunctionTemplateSpecialization();
3544 bool isFriend = NewMethod->getFriendObjectKind();
3545
3546 if (!isFriend && NewMethod->getLexicalDeclContext()->isRecord() &&
3547 !IsClassScopeExplicitSpecialization) {
3548 // -- Member function declarations with the same name and the
3549 // same parameter types cannot be overloaded if any of them
3550 // is a static member function declaration.
3551 if (OldMethod->isStatic() != NewMethod->isStatic()) {
3552 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member);
3553 Diag(OldLocation, PrevDiag) << Old << Old->getType();
3554 return true;
3555 }
3556
3557 // C++ [class.mem]p1:
3558 // [...] A member shall not be declared twice in the
3559 // member-specification, except that a nested class or member
3560 // class template can be declared and then later defined.
3561 if (!inTemplateInstantiation()) {
3562 unsigned NewDiag;
3563 if (isa<CXXConstructorDecl>(OldMethod))
3564 NewDiag = diag::err_constructor_redeclared;
3565 else if (isa<CXXDestructorDecl>(NewMethod))
3566 NewDiag = diag::err_destructor_redeclared;
3567 else if (isa<CXXConversionDecl>(NewMethod))
3568 NewDiag = diag::err_conv_function_redeclared;
3569 else
3570 NewDiag = diag::err_member_redeclared;
3571
3572 Diag(New->getLocation(), NewDiag);
3573 } else {
3574 Diag(New->getLocation(), diag::err_member_redeclared_in_instantiation)
3575 << New << New->getType();
3576 }
3577 Diag(OldLocation, PrevDiag) << Old << Old->getType();
3578 return true;
3579
3580 // Complain if this is an explicit declaration of a special
3581 // member that was initially declared implicitly.
3582 //
3583 // As an exception, it's okay to befriend such methods in order
3584 // to permit the implicit constructor/destructor/operator calls.
3585 } else if (OldMethod->isImplicit()) {
3586 if (isFriend) {
3587 NewMethod->setImplicit();
3588 } else {
3589 Diag(NewMethod->getLocation(),
3590 diag::err_definition_of_implicitly_declared_member)
3591 << New << getSpecialMember(OldMethod);
3592 return true;
3593 }
3594 } else if (OldMethod->getFirstDecl()->isExplicitlyDefaulted() && !isFriend) {
3595 Diag(NewMethod->getLocation(),
3596 diag::err_definition_of_explicitly_defaulted_member)
3597 << getSpecialMember(OldMethod);
3598 return true;
3599 }
3600 }
3601
3602 // C++11 [dcl.attr.noreturn]p1:
3603 // The first declaration of a function shall specify the noreturn
3604 // attribute if any declaration of that function specifies the noreturn
3605 // attribute.
3606 const CXX11NoReturnAttr *NRA = New->getAttr<CXX11NoReturnAttr>();
3607 if (NRA && !Old->hasAttr<CXX11NoReturnAttr>()) {
3608 Diag(NRA->getLocation(), diag::err_noreturn_missing_on_first_decl);
3609 Diag(Old->getFirstDecl()->getLocation(),
3610 diag::note_noreturn_missing_first_decl);
3611 }
3612
3613 // C++11 [dcl.attr.depend]p2:
3614 // The first declaration of a function shall specify the
3615 // carries_dependency attribute for its declarator-id if any declaration
3616 // of the function specifies the carries_dependency attribute.
3617 const CarriesDependencyAttr *CDA = New->getAttr<CarriesDependencyAttr>();
3618 if (CDA && !Old->hasAttr<CarriesDependencyAttr>()) {
3619 Diag(CDA->getLocation(),
3620 diag::err_carries_dependency_missing_on_first_decl) << 0/*Function*/;
3621 Diag(Old->getFirstDecl()->getLocation(),
3622 diag::note_carries_dependency_missing_first_decl) << 0/*Function*/;
3623 }
3624
3625 // (C++98 8.3.5p3):
3626 // All declarations for a function shall agree exactly in both the
3627 // return type and the parameter-type-list.
3628 // We also want to respect all the extended bits except noreturn.
3629
3630 // noreturn should now match unless the old type info didn't have it.
3631 QualType OldQTypeForComparison = OldQType;
3632 if (!OldTypeInfo.getNoReturn() && NewTypeInfo.getNoReturn()) {
3633 auto *OldType = OldQType->castAs<FunctionProtoType>();
3634 const FunctionType *OldTypeForComparison
3635 = Context.adjustFunctionType(OldType, OldTypeInfo.withNoReturn(true));
3636 OldQTypeForComparison = QualType(OldTypeForComparison, 0);
3637 assert(OldQTypeForComparison.isCanonical())((OldQTypeForComparison.isCanonical()) ? static_cast<void>
(0) : __assert_fail ("OldQTypeForComparison.isCanonical()", "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 3637, __PRETTY_FUNCTION__))
;
3638 }
3639
3640 if (haveIncompatibleLanguageLinkages(Old, New)) {
3641 // As a special case, retain the language linkage from previous
3642 // declarations of a friend function as an extension.
3643 //
3644 // This liberal interpretation of C++ [class.friend]p3 matches GCC/MSVC
3645 // and is useful because there's otherwise no way to specify language
3646 // linkage within class scope.
3647 //
3648 // Check cautiously as the friend object kind isn't yet complete.
3649 if (New->getFriendObjectKind() != Decl::FOK_None) {
3650 Diag(New->getLocation(), diag::ext_retained_language_linkage) << New;
3651 Diag(OldLocation, PrevDiag);
3652 } else {
3653 Diag(New->getLocation(), diag::err_different_language_linkage) << New;
3654 Diag(OldLocation, PrevDiag);
3655 return true;
3656 }
3657 }
3658
3659 // If the function types are compatible, merge the declarations. Ignore the
3660 // exception specifier because it was already checked above in
3661 // CheckEquivalentExceptionSpec, and we don't want follow-on diagnostics
3662 // about incompatible types under -fms-compatibility.
3663 if (Context.hasSameFunctionTypeIgnoringExceptionSpec(OldQTypeForComparison,
3664 NewQType))
3665 return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
3666
3667 // If the types are imprecise (due to dependent constructs in friends or
3668 // local extern declarations), it's OK if they differ. We'll check again
3669 // during instantiation.
3670 if (!canFullyTypeCheckRedeclaration(New, Old, NewQType, OldQType))
3671 return false;
3672
3673 // Fall through for conflicting redeclarations and redefinitions.
3674 }
3675
3676 // C: Function types need to be compatible, not identical. This handles
3677 // duplicate function decls like "void f(int); void f(enum X);" properly.
3678 if (!getLangOpts().CPlusPlus &&
3679 Context.typesAreCompatible(OldQType, NewQType)) {
3680 const FunctionType *OldFuncType = OldQType->getAs<FunctionType>();
3681 const FunctionType *NewFuncType = NewQType->getAs<FunctionType>();
3682 const FunctionProtoType *OldProto = nullptr;
3683 if (MergeTypeWithOld && isa<FunctionNoProtoType>(NewFuncType) &&
3684 (OldProto = dyn_cast<FunctionProtoType>(OldFuncType))) {
3685 // The old declaration provided a function prototype, but the
3686 // new declaration does not. Merge in the prototype.
3687 assert(!OldProto->hasExceptionSpec() && "Exception spec in C")((!OldProto->hasExceptionSpec() && "Exception spec in C"
) ? static_cast<void> (0) : __assert_fail ("!OldProto->hasExceptionSpec() && \"Exception spec in C\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 3687, __PRETTY_FUNCTION__))
;
3688 SmallVector<QualType, 16> ParamTypes(OldProto->param_types());
3689 NewQType =
3690 Context.getFunctionType(NewFuncType->getReturnType(), ParamTypes,
3691 OldProto->getExtProtoInfo());
3692 New->setType(NewQType);
3693 New->setHasInheritedPrototype();
3694
3695 // Synthesize parameters with the same types.
3696 SmallVector<ParmVarDecl*, 16> Params;
3697 for (const auto &ParamType : OldProto->param_types()) {
3698 ParmVarDecl *Param = ParmVarDecl::Create(Context, New, SourceLocation(),
3699 SourceLocation(), nullptr,
3700 ParamType, /*TInfo=*/nullptr,
3701 SC_None, nullptr);
3702 Param->setScopeInfo(0, Params.size());
3703 Param->setImplicit();
3704 Params.push_back(Param);
3705 }
3706
3707 New->setParams(Params);
3708 }
3709
3710 return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
3711 }
3712
3713 // Check if the function types are compatible when pointer size address
3714 // spaces are ignored.
3715 if (Context.hasSameFunctionTypeIgnoringPtrSizes(OldQType, NewQType))
3716 return false;
3717
3718 // GNU C permits a K&R definition to follow a prototype declaration
3719 // if the declared types of the parameters in the K&R definition
3720 // match the types in the prototype declaration, even when the
3721 // promoted types of the parameters from the K&R definition differ
3722 // from the types in the prototype. GCC then keeps the types from
3723 // the prototype.
3724 //
3725 // If a variadic prototype is followed by a non-variadic K&R definition,
3726 // the K&R definition becomes variadic. This is sort of an edge case, but
3727 // it's legal per the standard depending on how you read C99 6.7.5.3p15 and
3728 // C99 6.9.1p8.
3729 if (!getLangOpts().CPlusPlus &&
3730 Old->hasPrototype() && !New->hasPrototype() &&
3731 New->getType()->getAs<FunctionProtoType>() &&
3732 Old->getNumParams() == New->getNumParams()) {
3733 SmallVector<QualType, 16> ArgTypes;
3734 SmallVector<GNUCompatibleParamWarning, 16> Warnings;
3735 const FunctionProtoType *OldProto
3736 = Old->getType()->getAs<FunctionProtoType>();
3737 const FunctionProtoType *NewProto
3738 = New->getType()->getAs<FunctionProtoType>();
3739
3740 // Determine whether this is the GNU C extension.
3741 QualType MergedReturn = Context.mergeTypes(OldProto->getReturnType(),
3742 NewProto->getReturnType());
3743 bool LooseCompatible = !MergedReturn.isNull();
3744 for (unsigned Idx = 0, End = Old->getNumParams();
3745 LooseCompatible && Idx != End; ++Idx) {
3746 ParmVarDecl *OldParm = Old->getParamDecl(Idx);
3747 ParmVarDecl *NewParm = New->getParamDecl(Idx);
3748 if (Context.typesAreCompatible(OldParm->getType(),
3749 NewProto->getParamType(Idx))) {
3750 ArgTypes.push_back(NewParm->getType());
3751 } else if (Context.typesAreCompatible(OldParm->getType(),
3752 NewParm->getType(),
3753 /*CompareUnqualified=*/true)) {
3754 GNUCompatibleParamWarning Warn = { OldParm, NewParm,
3755 NewProto->getParamType(Idx) };
3756 Warnings.push_back(Warn);
3757 ArgTypes.push_back(NewParm->getType());
3758 } else
3759 LooseCompatible = false;
3760 }
3761
3762 if (LooseCompatible) {
3763 for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) {
3764 Diag(Warnings[Warn].NewParm->getLocation(),
3765 diag::ext_param_promoted_not_compatible_with_prototype)
3766 << Warnings[Warn].PromotedType
3767 << Warnings[Warn].OldParm->getType();
3768 if (Warnings[Warn].OldParm->getLocation().isValid())
3769 Diag(Warnings[Warn].OldParm->getLocation(),
3770 diag::note_previous_declaration);
3771 }
3772
3773 if (MergeTypeWithOld)
3774 New->setType(Context.getFunctionType(MergedReturn, ArgTypes,
3775 OldProto->getExtProtoInfo()));
3776 return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
3777 }
3778
3779 // Fall through to diagnose conflicting types.
3780 }
3781
3782 // A function that has already been declared has been redeclared or
3783 // defined with a different type; show an appropriate diagnostic.
3784
3785 // If the previous declaration was an implicitly-generated builtin
3786 // declaration, then at the very least we should use a specialized note.
3787 unsigned BuiltinID;
3788 if (Old->isImplicit() && (BuiltinID = Old->getBuiltinID())) {
3789 // If it's actually a library-defined builtin function like 'malloc'
3790 // or 'printf', just warn about the incompatible redeclaration.
3791 if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) {
3792 Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New;
3793 Diag(OldLocation, diag::note_previous_builtin_declaration)
3794 << Old << Old->getType();
3795 return false;
3796 }
3797
3798 PrevDiag = diag::note_previous_builtin_declaration;
3799 }
3800
3801 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName();
3802 Diag(OldLocation, PrevDiag) << Old << Old->getType();
3803 return true;
3804}
3805
3806/// Completes the merge of two function declarations that are
3807/// known to be compatible.
3808///
3809/// This routine handles the merging of attributes and other
3810/// properties of function declarations from the old declaration to
3811/// the new declaration, once we know that New is in fact a
3812/// redeclaration of Old.
3813///
3814/// \returns false
3815bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old,
3816 Scope *S, bool MergeTypeWithOld) {
3817 // Merge the attributes
3818 mergeDeclAttributes(New, Old);
3819
3820 // Merge "pure" flag.
3821 if (Old->isPure())
3822 New->setPure();
3823
3824 // Merge "used" flag.
3825 if (Old->getMostRecentDecl()->isUsed(false))
3826 New->setIsUsed();
3827
3828 // Merge attributes from the parameters. These can mismatch with K&R
3829 // declarations.
3830 if (New->getNumParams() == Old->getNumParams())
3831 for (unsigned i = 0, e = New->getNumParams(); i != e; ++i) {
3832 ParmVarDecl *NewParam = New->getParamDecl(i);
3833 ParmVarDecl *OldParam = Old->getParamDecl(i);
3834 mergeParamDeclAttributes(NewParam, OldParam, *this);
3835 mergeParamDeclTypes(NewParam, OldParam, *this);
3836 }
3837
3838 if (getLangOpts().CPlusPlus)
3839 return MergeCXXFunctionDecl(New, Old, S);
3840
3841 // Merge the function types so the we get the composite types for the return
3842 // and argument types. Per C11 6.2.7/4, only update the type if the old decl
3843 // was visible.
3844 QualType Merged = Context.mergeTypes(Old->getType(), New->getType());
3845 if (!Merged.isNull() && MergeTypeWithOld)
3846 New->setType(Merged);
3847
3848 return false;
3849}
3850
3851void Sema::mergeObjCMethodDecls(ObjCMethodDecl *newMethod,
3852 ObjCMethodDecl *oldMethod) {
3853 // Merge the attributes, including deprecated/unavailable
3854 AvailabilityMergeKind MergeKind =
3855 isa<ObjCProtocolDecl>(oldMethod->getDeclContext())
3856 ? AMK_ProtocolImplementation
3857 : isa<ObjCImplDecl>(newMethod->getDeclContext()) ? AMK_Redeclaration
3858 : AMK_Override;
3859
3860 mergeDeclAttributes(newMethod, oldMethod, MergeKind);
3861
3862 // Merge attributes from the parameters.
3863 ObjCMethodDecl::param_const_iterator oi = oldMethod->param_begin(),
3864 oe = oldMethod->param_end();
3865 for (ObjCMethodDecl::param_iterator
3866 ni = newMethod->param_begin(), ne = newMethod->param_end();
3867 ni != ne && oi != oe; ++ni, ++oi)
3868 mergeParamDeclAttributes(*ni, *oi, *this);
3869
3870 CheckObjCMethodOverride(newMethod, oldMethod);
3871}
3872
3873static void diagnoseVarDeclTypeMismatch(Sema &S, VarDecl *New, VarDecl* Old) {
3874 assert(!S.Context.hasSameType(New->getType(), Old->getType()))((!S.Context.hasSameType(New->getType(), Old->getType()
)) ? static_cast<void> (0) : __assert_fail ("!S.Context.hasSameType(New->getType(), Old->getType())"
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 3874, __PRETTY_FUNCTION__))
;
3875
3876 S.Diag(New->getLocation(), New->isThisDeclarationADefinition()
3877 ? diag::err_redefinition_different_type
3878 : diag::err_redeclaration_different_type)
3879 << New->getDeclName() << New->getType() << Old->getType();
3880
3881 diag::kind PrevDiag;
3882 SourceLocation OldLocation;
3883 std::tie(PrevDiag, OldLocation)
3884 = getNoteDiagForInvalidRedeclaration(Old, New);
3885 S.Diag(OldLocation, PrevDiag);
3886 New->setInvalidDecl();
3887}
3888
3889/// MergeVarDeclTypes - We parsed a variable 'New' which has the same name and
3890/// scope as a previous declaration 'Old'. Figure out how to merge their types,
3891/// emitting diagnostics as appropriate.
3892///
3893/// Declarations using the auto type specifier (C++ [decl.spec.auto]) call back
3894/// to here in AddInitializerToDecl. We can't check them before the initializer
3895/// is attached.
3896void Sema::MergeVarDeclTypes(VarDecl *New, VarDecl *Old,
3897 bool MergeTypeWithOld) {
3898 if (New->isInvalidDecl() || Old->isInvalidDecl())
3899 return;
3900
3901 QualType MergedT;
3902 if (getLangOpts().CPlusPlus) {
3903 if (New->getType()->isUndeducedType()) {
3904 // We don't know what the new type is until the initializer is attached.
3905 return;
3906 } else if (Context.hasSameType(New->getType(), Old->getType())) {
3907 // These could still be something that needs exception specs checked.
3908 return MergeVarDeclExceptionSpecs(New, Old);
3909 }
3910 // C++ [basic.link]p10:
3911 // [...] the types specified by all declarations referring to a given
3912 // object or function shall be identical, except that declarations for an
3913 // array object can specify array types that differ by the presence or
3914 // absence of a major array bound (8.3.4).
3915 else if (Old->getType()->isArrayType() && New->getType()->isArrayType()) {
3916 const ArrayType *OldArray = Context.getAsArrayType(Old->getType());
3917 const ArrayType *NewArray = Context.getAsArrayType(New->getType());
3918
3919 // We are merging a variable declaration New into Old. If it has an array
3920 // bound, and that bound differs from Old's bound, we should diagnose the
3921 // mismatch.
3922 if (!NewArray->isIncompleteArrayType() && !NewArray->isDependentType()) {
3923 for (VarDecl *PrevVD = Old->getMostRecentDecl(); PrevVD;
3924 PrevVD = PrevVD->getPreviousDecl()) {
3925 QualType PrevVDTy = PrevVD->getType();
3926 if (PrevVDTy->isIncompleteArrayType() || PrevVDTy->isDependentType())
3927 continue;
3928
3929 if (!Context.hasSameType(New->getType(), PrevVDTy))
3930 return diagnoseVarDeclTypeMismatch(*this, New, PrevVD);
3931 }
3932 }
3933
3934 if (OldArray->isIncompleteArrayType() && NewArray->isArrayType()) {
3935 if (Context.hasSameType(OldArray->getElementType(),
3936 NewArray->getElementType()))
3937 MergedT = New->getType();
3938 }
3939 // FIXME: Check visibility. New is hidden but has a complete type. If New
3940 // has no array bound, it should not inherit one from Old, if Old is not
3941 // visible.
3942 else if (OldArray->isArrayType() && NewArray->isIncompleteArrayType()) {
3943 if (Context.hasSameType(OldArray->getElementType(),
3944 NewArray->getElementType()))
3945 MergedT = Old->getType();
3946 }
3947 }
3948 else if (New->getType()->isObjCObjectPointerType() &&
3949 Old->getType()->isObjCObjectPointerType()) {
3950 MergedT = Context.mergeObjCGCQualifiers(New->getType(),
3951 Old->getType());
3952 }
3953 } else {
3954 // C 6.2.7p2:
3955 // All declarations that refer to the same object or function shall have
3956 // compatible type.
3957 MergedT = Context.mergeTypes(New->getType(), Old->getType());
3958 }
3959 if (MergedT.isNull()) {
3960 // It's OK if we couldn't merge types if either type is dependent, for a
3961 // block-scope variable. In other cases (static data members of class
3962 // templates, variable templates, ...), we require the types to be
3963 // equivalent.
3964 // FIXME: The C++ standard doesn't say anything about this.
3965 if ((New->getType()->isDependentType() ||
3966 Old->getType()->isDependentType()) && New->isLocalVarDecl()) {
3967 // If the old type was dependent, we can't merge with it, so the new type
3968 // becomes dependent for now. We'll reproduce the original type when we
3969 // instantiate the TypeSourceInfo for the variable.
3970 if (!New->getType()->isDependentType() && MergeTypeWithOld)
3971 New->setType(Context.DependentTy);
3972 return;
3973 }
3974 return diagnoseVarDeclTypeMismatch(*this, New, Old);
3975 }
3976
3977 // Don't actually update the type on the new declaration if the old
3978 // declaration was an extern declaration in a different scope.
3979 if (MergeTypeWithOld)
3980 New->setType(MergedT);
3981}
3982
3983static bool mergeTypeWithPrevious(Sema &S, VarDecl *NewVD, VarDecl *OldVD,
3984 LookupResult &Previous) {
3985 // C11 6.2.7p4:
3986 // For an identifier with internal or external linkage declared
3987 // in a scope in which a prior declaration of that identifier is
3988 // visible, if the prior declaration specifies internal or
3989 // external linkage, the type of the identifier at the later
3990 // declaration becomes the composite type.
3991 //
3992 // If the variable isn't visible, we do not merge with its type.
3993 if (Previous.isShadowed())
3994 return false;
3995
3996 if (S.getLangOpts().CPlusPlus) {
3997 // C++11 [dcl.array]p3:
3998 // If there is a preceding declaration of the entity in the same
3999 // scope in which the bound was specified, an omitted array bound
4000 // is taken to be the same as in that earlier declaration.
4001 return NewVD->isPreviousDeclInSameBlockScope() ||
4002 (!OldVD->getLexicalDeclContext()->isFunctionOrMethod() &&
4003 !NewVD->getLexicalDeclContext()->isFunctionOrMethod());
4004 } else {
4005 // If the old declaration was function-local, don't merge with its
4006 // type unless we're in the same function.
4007 return !OldVD->getLexicalDeclContext()->isFunctionOrMethod() ||
4008 OldVD->getLexicalDeclContext() == NewVD->getLexicalDeclContext();
4009 }
4010}
4011
4012/// MergeVarDecl - We just parsed a variable 'New' which has the same name
4013/// and scope as a previous declaration 'Old'. Figure out how to resolve this
4014/// situation, merging decls or emitting diagnostics as appropriate.
4015///
4016/// Tentative definition rules (C99 6.9.2p2) are checked by
4017/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative
4018/// definitions here, since the initializer hasn't been attached.
4019///
4020void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) {
4021 // If the new decl is already invalid, don't do any other checking.
4022 if (New->isInvalidDecl())
4023 return;
4024
4025 if (!shouldLinkPossiblyHiddenDecl(Previous, New))
4026 return;
4027
4028 VarTemplateDecl *NewTemplate = New->getDescribedVarTemplate();
4029
4030 // Verify the old decl was also a variable or variable template.
4031 VarDecl *Old = nullptr;
4032 VarTemplateDecl *OldTemplate = nullptr;
4033 if (Previous.isSingleResult()) {
4034 if (NewTemplate) {
4035 OldTemplate = dyn_cast<VarTemplateDecl>(Previous.getFoundDecl());
4036 Old = OldTemplate ? OldTemplate->getTemplatedDecl() : nullptr;
4037
4038 if (auto *Shadow =
4039 dyn_cast<UsingShadowDecl>(Previous.getRepresentativeDecl()))
4040 if (checkUsingShadowRedecl<VarTemplateDecl>(*this, Shadow, NewTemplate))
4041 return New->setInvalidDecl();
4042 } else {
4043 Old = dyn_cast<VarDecl>(Previous.getFoundDecl());
4044
4045 if (auto *Shadow =
4046 dyn_cast<UsingShadowDecl>(Previous.getRepresentativeDecl()))
4047 if (checkUsingShadowRedecl<VarDecl>(*this, Shadow, New))
4048 return New->setInvalidDecl();
4049 }
4050 }
4051 if (!Old) {
4052 Diag(New->getLocation(), diag::err_redefinition_different_kind)
4053 << New->getDeclName();
4054 notePreviousDefinition(Previous.getRepresentativeDecl(),
4055 New->getLocation());
4056 return New->setInvalidDecl();
4057 }
4058
4059 // If the old declaration was found in an inline namespace and the new
4060 // declaration was qualified, update the DeclContext to match.
4061 adjustDeclContextForDeclaratorDecl(New, Old);
4062
4063 // Ensure the template parameters are compatible.
4064 if (NewTemplate &&
4065 !TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
4066 OldTemplate->getTemplateParameters(),
4067 /*Complain=*/true, TPL_TemplateMatch))
4068 return New->setInvalidDecl();
4069
4070 // C++ [class.mem]p1:
4071 // A member shall not be declared twice in the member-specification [...]
4072 //
4073 // Here, we need only consider static data members.
4074 if (Old->isStaticDataMember() && !New->isOutOfLine()) {
4075 Diag(New->getLocation(), diag::err_duplicate_member)
4076 << New->getIdentifier();
4077 Diag(Old->getLocation(), diag::note_previous_declaration);
4078 New->setInvalidDecl();
4079 }
4080
4081 mergeDeclAttributes(New, Old);
4082 // Warn if an already-declared variable is made a weak_import in a subsequent
4083 // declaration
4084 if (New->hasAttr<WeakImportAttr>() &&
4085 Old->getStorageClass() == SC_None &&
4086 !Old->hasAttr<WeakImportAttr>()) {
4087 Diag(New->getLocation(), diag::warn_weak_import) << New->getDeclName();
4088 notePreviousDefinition(Old, New->getLocation());
4089 // Remove weak_import attribute on new declaration.
4090 New->dropAttr<WeakImportAttr>();
4091 }
4092
4093 if (New->hasAttr<InternalLinkageAttr>() &&
4094 !Old->hasAttr<InternalLinkageAttr>()) {
4095 Diag(New->getLocation(), diag::err_internal_linkage_redeclaration)
4096 << New->getDeclName();
4097 notePreviousDefinition(Old, New->getLocation());
4098 New->dropAttr<InternalLinkageAttr>();
4099 }
4100
4101 // Merge the types.
4102 VarDecl *MostRecent = Old->getMostRecentDecl();
4103 if (MostRecent != Old) {
4104 MergeVarDeclTypes(New, MostRecent,
4105 mergeTypeWithPrevious(*this, New, MostRecent, Previous));
4106 if (New->isInvalidDecl())
4107 return;
4108 }
4109
4110 MergeVarDeclTypes(New, Old, mergeTypeWithPrevious(*this, New, Old, Previous));
4111 if (New->isInvalidDecl())
4112 return;
4113
4114 diag::kind PrevDiag;
4115 SourceLocation OldLocation;
4116 std::tie(PrevDiag, OldLocation) =
4117 getNoteDiagForInvalidRedeclaration(Old, New);
4118
4119 // [dcl.stc]p8: Check if we have a non-static decl followed by a static.
4120 if (New->getStorageClass() == SC_Static &&
4121 !New->isStaticDataMember() &&
4122 Old->hasExternalFormalLinkage()) {
4123 if (getLangOpts().MicrosoftExt) {
4124 Diag(New->getLocation(), diag::ext_static_non_static)
4125 << New->getDeclName();
4126 Diag(OldLocation, PrevDiag);
4127 } else {
4128 Diag(New->getLocation(), diag::err_static_non_static)
4129 << New->getDeclName();
4130 Diag(OldLocation, PrevDiag);
4131 return New->setInvalidDecl();
4132 }
4133 }
4134 // C99 6.2.2p4:
4135 // For an identifier declared with the storage-class specifier
4136 // extern in a scope in which a prior declaration of that
4137 // identifier is visible,23) if the prior declaration specifies
4138 // internal or external linkage, the linkage of the identifier at
4139 // the later declaration is the same as the linkage specified at
4140 // the prior declaration. If no prior declaration is visible, or
4141 // if the prior declaration specifies no linkage, then the
4142 // identifier has external linkage.
4143 if (New->hasExternalStorage() && Old->hasLinkage())
4144 /* Okay */;
4145 else if (New->getCanonicalDecl()->getStorageClass() != SC_Static &&
4146 !New->isStaticDataMember() &&
4147 Old->getCanonicalDecl()->getStorageClass() == SC_Static) {
4148 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName();
4149 Diag(OldLocation, PrevDiag);
4150 return New->setInvalidDecl();
4151 }
4152
4153 // Check if extern is followed by non-extern and vice-versa.
4154 if (New->hasExternalStorage() &&
4155 !Old->hasLinkage() && Old->isLocalVarDeclOrParm()) {
4156 Diag(New->getLocation(), diag::err_extern_non_extern) << New->getDeclName();
4157 Diag(OldLocation, PrevDiag);
4158 return New->setInvalidDecl();
4159 }
4160 if (Old->hasLinkage() && New->isLocalVarDeclOrParm() &&
4161 !New->hasExternalStorage()) {
4162 Diag(New->getLocation(), diag::err_non_extern_extern) << New->getDeclName();
4163 Diag(OldLocation, PrevDiag);
4164 return New->setInvalidDecl();
4165 }
4166
4167 if (CheckRedeclarationModuleOwnership(New, Old))
4168 return;
4169
4170 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup.
4171
4172 // FIXME: The test for external storage here seems wrong? We still
4173 // need to check for mismatches.
4174 if (!New->hasExternalStorage() && !New->isFileVarDecl() &&
4175 // Don't complain about out-of-line definitions of static members.
4176 !(Old->getLexicalDeclContext()->isRecord() &&
4177 !New->getLexicalDeclContext()->isRecord())) {
4178 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName();
4179 Diag(OldLocation, PrevDiag);
4180 return New->setInvalidDecl();
4181 }
4182
4183 if (New->isInline() && !Old->getMostRecentDecl()->isInline()) {
4184 if (VarDecl *Def = Old->getDefinition()) {
4185 // C++1z [dcl.fcn.spec]p4:
4186 // If the definition of a variable appears in a translation unit before
4187 // its first declaration as inline, the program is ill-formed.
4188 Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
4189 Diag(Def->getLocation(), diag::note_previous_definition);
4190 }
4191 }
4192
4193 // If this redeclaration makes the variable inline, we may need to add it to
4194 // UndefinedButUsed.
4195 if (!Old->isInline() && New->isInline() && Old->isUsed(false) &&
4196 !Old->getDefinition() && !New->isThisDeclarationADefinition())
4197 UndefinedButUsed.insert(std::make_pair(Old->getCanonicalDecl(),
4198 SourceLocation()));
4199
4200 if (New->getTLSKind() != Old->getTLSKind()) {
4201 if (!Old->getTLSKind()) {
4202 Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName();
4203 Diag(OldLocation, PrevDiag);
4204 } else if (!New->getTLSKind()) {
4205 Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName();
4206 Diag(OldLocation, PrevDiag);
4207 } else {
4208 // Do not allow redeclaration to change the variable between requiring
4209 // static and dynamic initialization.
4210 // FIXME: GCC allows this, but uses the TLS keyword on the first
4211 // declaration to determine the kind. Do we need to be compatible here?
4212 Diag(New->getLocation(), diag::err_thread_thread_different_kind)
4213 << New->getDeclName() << (New->getTLSKind() == VarDecl::TLS_Dynamic);
4214 Diag(OldLocation, PrevDiag);
4215 }
4216 }
4217
4218 // C++ doesn't have tentative definitions, so go right ahead and check here.
4219 if (getLangOpts().CPlusPlus &&
4220 New->isThisDeclarationADefinition() == VarDecl::Definition) {
4221 if (Old->isStaticDataMember() && Old->getCanonicalDecl()->isInline() &&
4222 Old->getCanonicalDecl()->isConstexpr()) {
4223 // This definition won't be a definition any more once it's been merged.
4224 Diag(New->getLocation(),
4225 diag::warn_deprecated_redundant_constexpr_static_def);
4226 } else if (VarDecl *Def = Old->getDefinition()) {
4227 if (checkVarDeclRedefinition(Def, New))
4228 return;
4229 }
4230 }
4231
4232 if (haveIncompatibleLanguageLinkages(Old, New)) {
4233 Diag(New->getLocation(), diag::err_different_language_linkage) << New;
4234 Diag(OldLocation, PrevDiag);
4235 New->setInvalidDecl();
4236 return;
4237 }
4238
4239 // Merge "used" flag.
4240 if (Old->getMostRecentDecl()->isUsed(false))
4241 New->setIsUsed();
4242
4243 // Keep a chain of previous declarations.
4244 New->setPreviousDecl(Old);
4245 if (NewTemplate)
4246 NewTemplate->setPreviousDecl(OldTemplate);
4247
4248 // Inherit access appropriately.
4249 New->setAccess(Old->getAccess());
4250 if (NewTemplate)
4251 NewTemplate->setAccess(New->getAccess());
4252
4253 if (Old->isInline())
4254 New->setImplicitlyInline();
4255}
4256
4257void Sema::notePreviousDefinition(const NamedDecl *Old, SourceLocation New) {
4258 SourceManager &SrcMgr = getSourceManager();
4259 auto FNewDecLoc = SrcMgr.getDecomposedLoc(New);
4260 auto FOldDecLoc = SrcMgr.getDecomposedLoc(Old->getLocation());
4261 auto *FNew = SrcMgr.getFileEntryForID(FNewDecLoc.first);
4262 auto *FOld = SrcMgr.getFileEntryForID(FOldDecLoc.first);
4263 auto &HSI = PP.getHeaderSearchInfo();
4264 StringRef HdrFilename =
4265 SrcMgr.getFilename(SrcMgr.getSpellingLoc(Old->getLocation()));
4266
4267 auto noteFromModuleOrInclude = [&](Module *Mod,
4268 SourceLocation IncLoc) -> bool {
4269 // Redefinition errors with modules are common with non modular mapped
4270 // headers, example: a non-modular header H in module A that also gets
4271 // included directly in a TU. Pointing twice to the same header/definition
4272 // is confusing, try to get better diagnostics when modules is on.
4273 if (IncLoc.isValid()) {
4274 if (Mod) {
4275 Diag(IncLoc, diag::note_redefinition_modules_same_file)
4276 << HdrFilename.str() << Mod->getFullModuleName();
4277 if (!Mod->DefinitionLoc.isInvalid())
4278 Diag(Mod->DefinitionLoc, diag::note_defined_here)
4279 << Mod->getFullModuleName();
4280 } else {
4281 Diag(IncLoc, diag::note_redefinition_include_same_file)
4282 << HdrFilename.str();
4283 }
4284 return true;
4285 }
4286
4287 return false;
4288 };
4289
4290 // Is it the same file and same offset? Provide more information on why
4291 // this leads to a redefinition error.
4292 if (FNew == FOld && FNewDecLoc.second == FOldDecLoc.second) {
4293 SourceLocation OldIncLoc = SrcMgr.getIncludeLoc(FOldDecLoc.first);
4294 SourceLocation NewIncLoc = SrcMgr.getIncludeLoc(FNewDecLoc.first);
4295 bool EmittedDiag =
4296 noteFromModuleOrInclude(Old->getOwningModule(), OldIncLoc);
4297 EmittedDiag |= noteFromModuleOrInclude(getCurrentModule(), NewIncLoc);
4298
4299 // If the header has no guards, emit a note suggesting one.
4300 if (FOld && !HSI.isFileMultipleIncludeGuarded(FOld))
4301 Diag(Old->getLocation(), diag::note_use_ifdef_guards);
4302
4303 if (EmittedDiag)
4304 return;
4305 }
4306
4307 // Redefinition coming from different files or couldn't do better above.
4308 if (Old->getLocation().isValid())
4309 Diag(Old->getLocation(), diag::note_previous_definition);
4310}
4311
4312/// We've just determined that \p Old and \p New both appear to be definitions
4313/// of the same variable. Either diagnose or fix the problem.
4314bool Sema::checkVarDeclRedefinition(VarDecl *Old, VarDecl *New) {
4315 if (!hasVisibleDefinition(Old) &&
4316 (New->getFormalLinkage() == InternalLinkage ||
4317 New->isInline() ||
4318 New->getDescribedVarTemplate() ||
4319 New->getNumTemplateParameterLists() ||
4320 New->getDeclContext()->isDependentContext())) {
4321 // The previous definition is hidden, and multiple definitions are
4322 // permitted (in separate TUs). Demote this to a declaration.
4323 New->demoteThisDefinitionToDeclaration();
4324
4325 // Make the canonical definition visible.
4326 if (auto *OldTD = Old->getDescribedVarTemplate())
4327 makeMergedDefinitionVisible(OldTD);
4328 makeMergedDefinitionVisible(Old);
4329 return false;
4330 } else {
4331 Diag(New->getLocation(), diag::err_redefinition) << New;
4332 notePreviousDefinition(Old, New->getLocation());
4333 New->setInvalidDecl();
4334 return true;
4335 }
4336}
4337
4338/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
4339/// no declarator (e.g. "struct foo;") is parsed.
4340Decl *
4341Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
4342 RecordDecl *&AnonRecord) {
4343 return ParsedFreeStandingDeclSpec(S, AS, DS, MultiTemplateParamsArg(), false,
4344 AnonRecord);
4345}
4346
4347// The MS ABI changed between VS2013 and VS2015 with regard to numbers used to
4348// disambiguate entities defined in different scopes.
4349// While the VS2015 ABI fixes potential miscompiles, it is also breaks
4350// compatibility.
4351// We will pick our mangling number depending on which version of MSVC is being
4352// targeted.
4353static unsigned getMSManglingNumber(const LangOptions &LO, Scope *S) {
4354 return LO.isCompatibleWithMSVC(LangOptions::MSVC2015)
4355 ? S->getMSCurManglingNumber()
4356 : S->getMSLastManglingNumber();
4357}
4358
4359void Sema::handleTagNumbering(const TagDecl *Tag, Scope *TagScope) {
4360 if (!Context.getLangOpts().CPlusPlus)
4361 return;
4362
4363 if (isa<CXXRecordDecl>(Tag->getParent())) {
4364 // If this tag is the direct child of a class, number it if
4365 // it is anonymous.
4366 if (!Tag->getName().empty() || Tag->getTypedefNameForAnonDecl())
4367 return;
4368 MangleNumberingContext &MCtx =
4369 Context.getManglingNumberContext(Tag->getParent());
4370 Context.setManglingNumber(
4371 Tag, MCtx.getManglingNumber(
4372 Tag, getMSManglingNumber(getLangOpts(), TagScope)));
4373 return;
4374 }
4375
4376 // If this tag isn't a direct child of a class, number it if it is local.
4377 MangleNumberingContext *MCtx;
4378 Decl *ManglingContextDecl;
4379 std::tie(MCtx, ManglingContextDecl) =
4380 getCurrentMangleNumberContext(Tag->getDeclContext());
4381 if (MCtx) {
4382 Context.setManglingNumber(
4383 Tag, MCtx->getManglingNumber(
4384 Tag, getMSManglingNumber(getLangOpts(), TagScope)));
4385 }
4386}
4387
4388namespace {
4389struct NonCLikeKind {
4390 enum {
4391 None,
4392 BaseClass,
4393 DefaultMemberInit,
4394 Lambda,
4395 Friend,
4396 OtherMember,
4397 Invalid,
4398 } Kind = None;
4399 SourceRange Range;
4400
4401 explicit operator bool() { return Kind != None; }
4402};
4403}
4404
4405/// Determine whether a class is C-like, according to the rules of C++
4406/// [dcl.typedef] for anonymous classes with typedef names for linkage.
4407static NonCLikeKind getNonCLikeKindForAnonymousStruct(const CXXRecordDecl *RD) {
4408 if (RD->isInvalidDecl())
4409 return {NonCLikeKind::Invalid, {}};
4410
4411 // C++ [dcl.typedef]p9: [P1766R1]
4412 // An unnamed class with a typedef name for linkage purposes shall not
4413 //
4414 // -- have any base classes
4415 if (RD->getNumBases())
4416 return {NonCLikeKind::BaseClass,
4417 SourceRange(RD->bases_begin()->getBeginLoc(),
4418 RD->bases_end()[-1].getEndLoc())};
4419 bool Invalid = false;
4420 for (Decl *D : RD->decls()) {
4421 // Don't complain about things we already diagnosed.
4422 if (D->isInvalidDecl()) {
4423 Invalid = true;
4424 continue;
4425 }
4426
4427 // -- have any [...] default member initializers
4428 if (auto *FD = dyn_cast<FieldDecl>(D)) {
4429 if (FD->hasInClassInitializer()) {
4430 auto *Init = FD->getInClassInitializer();
4431 return {NonCLikeKind::DefaultMemberInit,
4432 Init ? Init->getSourceRange() : D->getSourceRange()};
4433 }
4434 continue;
4435 }
4436
4437 // FIXME: We don't allow friend declarations. This violates the wording of
4438 // P1766, but not the intent.
4439 if (isa<FriendDecl>(D))
4440 return {NonCLikeKind::Friend, D->getSourceRange()};
4441
4442 // -- declare any members other than non-static data members, member
4443 // enumerations, or member classes,
4444 if (isa<StaticAssertDecl>(D) || isa<IndirectFieldDecl>(D) ||
4445 isa<EnumDecl>(D))
4446 continue;
4447 auto *MemberRD = dyn_cast<CXXRecordDecl>(D);
4448 if (!MemberRD) {
4449 if (D->isImplicit())
4450 continue;
4451 return {NonCLikeKind::OtherMember, D->getSourceRange()};
4452 }
4453
4454 // -- contain a lambda-expression,
4455 if (MemberRD->isLambda())
4456 return {NonCLikeKind::Lambda, MemberRD->getSourceRange()};
4457
4458 // and all member classes shall also satisfy these requirements
4459 // (recursively).
4460 if (MemberRD->isThisDeclarationADefinition()) {
4461 if (auto Kind = getNonCLikeKindForAnonymousStruct(MemberRD))
4462 return Kind;
4463 }
4464 }
4465
4466 return {Invalid ? NonCLikeKind::Invalid : NonCLikeKind::None, {}};
4467}
4468
4469void Sema::setTagNameForLinkagePurposes(TagDecl *TagFromDeclSpec,
4470 TypedefNameDecl *NewTD) {
4471 if (TagFromDeclSpec->isInvalidDecl())
4472 return;
4473
4474 // Do nothing if the tag already has a name for linkage purposes.
4475 if (TagFromDeclSpec->hasNameForLinkage())
4476 return;
4477
4478 // A well-formed anonymous tag must always be a TUK_Definition.
4479 assert(TagFromDeclSpec->isThisDeclarationADefinition())((TagFromDeclSpec->isThisDeclarationADefinition()) ? static_cast
<void> (0) : __assert_fail ("TagFromDeclSpec->isThisDeclarationADefinition()"
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 4479, __PRETTY_FUNCTION__))
;
4480
4481 // The type must match the tag exactly; no qualifiers allowed.
4482 if (!Context.hasSameType(NewTD->getUnderlyingType(),
4483 Context.getTagDeclType(TagFromDeclSpec))) {
4484 if (getLangOpts().CPlusPlus)
4485 Context.addTypedefNameForUnnamedTagDecl(TagFromDeclSpec, NewTD);
4486 return;
4487 }
4488
4489 // C++ [dcl.typedef]p9: [P1766R1, applied as DR]
4490 // An unnamed class with a typedef name for linkage purposes shall [be
4491 // C-like].
4492 //
4493 // FIXME: Also diagnose if we've already computed the linkage. That ideally
4494 // shouldn't happen, but there are constructs that the language rule doesn't
4495 // disallow for which we can't reasonably avoid computing linkage early.
4496 const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TagFromDeclSpec);
4497 NonCLikeKind NonCLike = RD ? getNonCLikeKindForAnonymousStruct(RD)
4498 : NonCLikeKind();
4499 bool ChangesLinkage = TagFromDeclSpec->hasLinkageBeenComputed();
4500 if (NonCLike || ChangesLinkage) {
4501 if (NonCLike.Kind == NonCLikeKind::Invalid)
4502 return;
4503
4504 unsigned DiagID = diag::ext_non_c_like_anon_struct_in_typedef;
4505 if (ChangesLinkage) {
4506 // If the linkage changes, we can't accept this as an extension.
4507 if (NonCLike.Kind == NonCLikeKind::None)
4508 DiagID = diag::err_typedef_changes_linkage;
4509 else
4510 DiagID = diag::err_non_c_like_anon_struct_in_typedef;
4511 }
4512
4513 SourceLocation FixitLoc =
4514 getLocForEndOfToken(TagFromDeclSpec->getInnerLocStart());
4515 llvm::SmallString<40> TextToInsert;
4516 TextToInsert += ' ';
4517 TextToInsert += NewTD->getIdentifier()->getName();
4518
4519 Diag(FixitLoc, DiagID)
4520 << isa<TypeAliasDecl>(NewTD)
4521 << FixItHint::CreateInsertion(FixitLoc, TextToInsert);
4522 if (NonCLike.Kind != NonCLikeKind::None) {
4523 Diag(NonCLike.Range.getBegin(), diag::note_non_c_like_anon_struct)
4524 << NonCLike.Kind - 1 << NonCLike.Range;
4525 }
4526 Diag(NewTD->getLocation(), diag::note_typedef_for_linkage_here)
4527 << NewTD << isa<TypeAliasDecl>(NewTD);
4528
4529 if (ChangesLinkage)
4530 return;
4531 }
4532
4533 // Otherwise, set this as the anon-decl typedef for the tag.
4534 TagFromDeclSpec->setTypedefNameForAnonDecl(NewTD);
4535}
4536
4537static unsigned GetDiagnosticTypeSpecifierID(DeclSpec::TST T) {
4538 switch (T) {
4539 case DeclSpec::TST_class:
4540 return 0;
4541 case DeclSpec::TST_struct:
4542 return 1;
4543 case DeclSpec::TST_interface:
4544 return 2;
4545 case DeclSpec::TST_union:
4546 return 3;
4547 case DeclSpec::TST_enum:
4548 return 4;
4549 default:
4550 llvm_unreachable("unexpected type specifier")::llvm::llvm_unreachable_internal("unexpected type specifier"
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 4550)
;
4551 }
4552}
4553
4554/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
4555/// no declarator (e.g. "struct foo;") is parsed. It also accepts template
4556/// parameters to cope with template friend declarations.
4557Decl *
4558Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
4559 MultiTemplateParamsArg TemplateParams,
4560 bool IsExplicitInstantiation,
4561 RecordDecl *&AnonRecord) {
4562 Decl *TagD = nullptr;
4563 TagDecl *Tag = nullptr;
4564 if (DS.getTypeSpecType() == DeclSpec::TST_class ||
4565 DS.getTypeSpecType() == DeclSpec::TST_struct ||
4566 DS.getTypeSpecType() == DeclSpec::TST_interface ||
4567 DS.getTypeSpecType() == DeclSpec::TST_union ||
4568 DS.getTypeSpecType() == DeclSpec::TST_enum) {
4569 TagD = DS.getRepAsDecl();
4570
4571 if (!TagD) // We probably had an error
4572 return nullptr;
4573
4574 // Note that the above type specs guarantee that the
4575 // type rep is a Decl, whereas in many of the others
4576 // it's a Type.
4577 if (isa<TagDecl>(TagD))
4578 Tag = cast<TagDecl>(TagD);
4579 else if (ClassTemplateDecl *CTD = dyn_cast<ClassTemplateDecl>(TagD))
4580 Tag = CTD->getTemplatedDecl();
4581 }
4582
4583 if (Tag) {
4584 handleTagNumbering(Tag, S);
4585 Tag->setFreeStanding();
4586 if (Tag->isInvalidDecl())
4587 return Tag;
4588 }
4589
4590 if (unsigned TypeQuals = DS.getTypeQualifiers()) {
4591 // Enforce C99 6.7.3p2: "Types other than pointer types derived from object
4592 // or incomplete types shall not be restrict-qualified."
4593 if (TypeQuals & DeclSpec::TQ_restrict)
4594 Diag(DS.getRestrictSpecLoc(),
4595 diag::err_typecheck_invalid_restrict_not_pointer_noarg)
4596 << DS.getSourceRange();
4597 }
4598
4599 if (DS.isInlineSpecified())
4600 Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function)
4601 << getLangOpts().CPlusPlus17;
4602
4603 if (DS.hasConstexprSpecifier()) {
4604 // C++0x [dcl.constexpr]p1: constexpr can only be applied to declarations
4605 // and definitions of functions and variables.
4606 // C++2a [dcl.constexpr]p1: The consteval specifier shall be applied only to
4607 // the declaration of a function or function template
4608 if (Tag)
4609 Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_tag)
4610 << GetDiagnosticTypeSpecifierID(DS.getTypeSpecType())
4611 << static_cast<int>(DS.getConstexprSpecifier());
4612 else
4613 Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_wrong_decl_kind)
4614 << static_cast<int>(DS.getConstexprSpecifier());
4615 // Don't emit warnings after this error.
4616 return TagD;
4617 }
4618
4619 DiagnoseFunctionSpecifiers(DS);
4620
4621 if (DS.isFriendSpecified()) {
4622 // If we're dealing with a decl but not a TagDecl, assume that
4623 // whatever routines created it handled the friendship aspect.
4624 if (TagD && !Tag)
4625 return nullptr;
4626 return ActOnFriendTypeDecl(S, DS, TemplateParams);
4627 }
4628
4629 const CXXScopeSpec &SS = DS.getTypeSpecScope();
4630 bool IsExplicitSpecialization =
4631 !TemplateParams.empty() && TemplateParams.back()->size() == 0;
4632 if (Tag && SS.isNotEmpty() && !Tag->isCompleteDefinition() &&
4633 !IsExplicitInstantiation && !IsExplicitSpecialization &&
4634 !isa<ClassTemplatePartialSpecializationDecl>(Tag)) {
4635 // Per C++ [dcl.type.elab]p1, a class declaration cannot have a
4636 // nested-name-specifier unless it is an explicit instantiation
4637 // or an explicit specialization.
4638 //
4639 // FIXME: We allow class template partial specializations here too, per the
4640 // obvious intent of DR1819.
4641 //
4642 // Per C++ [dcl.enum]p1, an opaque-enum-declaration can't either.
4643 Diag(SS.getBeginLoc(), diag::err_standalone_class_nested_name_specifier)
4644 << GetDiagnosticTypeSpecifierID(DS.getTypeSpecType()) << SS.getRange();
4645 return nullptr;
4646 }
4647
4648 // Track whether this decl-specifier declares anything.
4649 bool DeclaresAnything = true;
4650
4651 // Handle anonymous struct definitions.
4652 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) {
4653 if (!Record->getDeclName() && Record->isCompleteDefinition() &&
4654 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) {
4655 if (getLangOpts().CPlusPlus ||
4656 Record->getDeclContext()->isRecord()) {
4657 // If CurContext is a DeclContext that can contain statements,
4658 // RecursiveASTVisitor won't visit the decls that
4659 // BuildAnonymousStructOrUnion() will put into CurContext.
4660 // Also store them here so that they can be part of the
4661 // DeclStmt that gets created in this case.
4662 // FIXME: Also return the IndirectFieldDecls created by
4663 // BuildAnonymousStructOr union, for the same reason?
4664 if (CurContext->isFunctionOrMethod())
4665 AnonRecord = Record;
4666 return BuildAnonymousStructOrUnion(S, DS, AS, Record,
4667 Context.getPrintingPolicy());
4668 }
4669
4670 DeclaresAnything = false;
4671 }
4672 }
4673
4674 // C11 6.7.2.1p2:
4675 // A struct-declaration that does not declare an anonymous structure or
4676 // anonymous union shall contain a struct-declarator-list.
4677 //
4678 // This rule also existed in C89 and C99; the grammar for struct-declaration
4679 // did not permit a struct-declaration without a struct-declarator-list.
4680 if (!getLangOpts().CPlusPlus && CurContext->isRecord() &&
4681 DS.getStorageClassSpec() == DeclSpec::SCS_unspecified) {
4682 // Check for Microsoft C extension: anonymous struct/union member.
4683 // Handle 2 kinds of anonymous struct/union:
4684 // struct STRUCT;
4685 // union UNION;
4686 // and
4687 // STRUCT_TYPE; <- where STRUCT_TYPE is a typedef struct.
4688 // UNION_TYPE; <- where UNION_TYPE is a typedef union.
4689 if ((Tag && Tag->getDeclName()) ||
4690 DS.getTypeSpecType() == DeclSpec::TST_typename) {
4691 RecordDecl *Record = nullptr;
4692 if (Tag)
4693 Record = dyn_cast<RecordDecl>(Tag);
4694 else if (const RecordType *RT =
4695 DS.getRepAsType().get()->getAsStructureType())
4696 Record = RT->getDecl();
4697 else if (const RecordType *UT = DS.getRepAsType().get()->getAsUnionType())
4698 Record = UT->getDecl();
4699
4700 if (Record && getLangOpts().MicrosoftExt) {
4701 Diag(DS.getBeginLoc(), diag::ext_ms_anonymous_record)
4702 << Record->isUnion() << DS.getSourceRange();
4703 return BuildMicrosoftCAnonymousStruct(S, DS, Record);
4704 }
4705
4706 DeclaresAnything = false;
4707 }
4708 }
4709
4710 // Skip all the checks below if we have a type error.
4711 if (DS.getTypeSpecType() == DeclSpec::TST_error ||
4712 (TagD && TagD->isInvalidDecl()))
4713 return TagD;
4714
4715 if (getLangOpts().CPlusPlus &&
4716 DS.getStorageClassSpec() != DeclSpec::SCS_typedef)
4717 if (EnumDecl *Enum = dyn_cast_or_null<EnumDecl>(Tag))
4718 if (Enum->enumerator_begin() == Enum->enumerator_end() &&
4719 !Enum->getIdentifier() && !Enum->isInvalidDecl())
4720 DeclaresAnything = false;
4721
4722 if (!DS.isMissingDeclaratorOk()) {
4723 // Customize diagnostic for a typedef missing a name.
4724 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
4725 Diag(DS.getBeginLoc(), diag::ext_typedef_without_a_name)
4726 << DS.getSourceRange();
4727 else
4728 DeclaresAnything = false;
4729 }
4730
4731 if (DS.isModulePrivateSpecified() &&
4732 Tag && Tag->getDeclContext()->isFunctionOrMethod())
4733 Diag(DS.getModulePrivateSpecLoc(), diag::err_module_private_local_class)
4734 << Tag->getTagKind()
4735 << FixItHint::CreateRemoval(DS.getModulePrivateSpecLoc());
4736
4737 ActOnDocumentableDecl(TagD);
4738
4739 // C 6.7/2:
4740 // A declaration [...] shall declare at least a declarator [...], a tag,
4741 // or the members of an enumeration.
4742 // C++ [dcl.dcl]p3:
4743 // [If there are no declarators], and except for the declaration of an
4744 // unnamed bit-field, the decl-specifier-seq shall introduce one or more
4745 // names into the program, or shall redeclare a name introduced by a
4746 // previous declaration.
4747 if (!DeclaresAnything) {
4748 // In C, we allow this as a (popular) extension / bug. Don't bother
4749 // producing further diagnostics for redundant qualifiers after this.
4750 Diag(DS.getBeginLoc(), (IsExplicitInstantiation || !TemplateParams.empty())
4751 ? diag::err_no_declarators
4752 : diag::ext_no_declarators)
4753 << DS.getSourceRange();
4754 return TagD;
4755 }
4756
4757 // C++ [dcl.stc]p1:
4758 // If a storage-class-specifier appears in a decl-specifier-seq, [...] the
4759 // init-declarator-list of the declaration shall not be empty.
4760 // C++ [dcl.fct.spec]p1:
4761 // If a cv-qualifier appears in a decl-specifier-seq, the
4762 // init-declarator-list of the declaration shall not be empty.
4763 //
4764 // Spurious qualifiers here appear to be valid in C.
4765 unsigned DiagID = diag::warn_standalone_specifier;
4766 if (getLangOpts().CPlusPlus)
4767 DiagID = diag::ext_standalone_specifier;
4768
4769 // Note that a linkage-specification sets a storage class, but
4770 // 'extern "C" struct foo;' is actually valid and not theoretically
4771 // useless.
4772 if (DeclSpec::SCS SCS = DS.getStorageClassSpec()) {
4773 if (SCS == DeclSpec::SCS_mutable)
4774 // Since mutable is not a viable storage class specifier in C, there is
4775 // no reason to treat it as an extension. Instead, diagnose as an error.
4776 Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_nonmember);
4777 else if (!DS.isExternInLinkageSpec() && SCS != DeclSpec::SCS_typedef)
4778 Diag(DS.getStorageClassSpecLoc(), DiagID)
4779 << DeclSpec::getSpecifierName(SCS);
4780 }
4781
4782 if (DeclSpec::TSCS TSCS = DS.getThreadStorageClassSpec())
4783 Diag(DS.getThreadStorageClassSpecLoc(), DiagID)
4784 << DeclSpec::getSpecifierName(TSCS);
4785 if (DS.getTypeQualifiers()) {
4786 if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
4787 Diag(DS.getConstSpecLoc(), DiagID) << "const";
4788 if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
4789 Diag(DS.getConstSpecLoc(), DiagID) << "volatile";
4790 // Restrict is covered above.
4791 if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
4792 Diag(DS.getAtomicSpecLoc(), DiagID) << "_Atomic";
4793 if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
4794 Diag(DS.getUnalignedSpecLoc(), DiagID) << "__unaligned";
4795 }
4796
4797 // Warn about ignored type attributes, for example:
4798 // __attribute__((aligned)) struct A;
4799 // Attributes should be placed after tag to apply to type declaration.
4800 if (!DS.getAttributes().empty()) {
4801 DeclSpec::TST TypeSpecType = DS.getTypeSpecType();
4802 if (TypeSpecType == DeclSpec::TST_class ||
4803 TypeSpecType == DeclSpec::TST_struct ||
4804 TypeSpecType == DeclSpec::TST_interface ||
4805 TypeSpecType == DeclSpec::TST_union ||
4806 TypeSpecType == DeclSpec::TST_enum) {
4807 for (const ParsedAttr &AL : DS.getAttributes())
4808 Diag(AL.getLoc(), diag::warn_declspec_attribute_ignored)
4809 << AL << GetDiagnosticTypeSpecifierID(TypeSpecType);
4810 }
4811 }
4812
4813 return TagD;
4814}
4815
4816/// We are trying to inject an anonymous member into the given scope;
4817/// check if there's an existing declaration that can't be overloaded.
4818///
4819/// \return true if this is a forbidden redeclaration
4820static bool CheckAnonMemberRedeclaration(Sema &SemaRef,
4821 Scope *S,
4822 DeclContext *Owner,
4823 DeclarationName Name,
4824 SourceLocation NameLoc,
4825 bool IsUnion) {
4826 LookupResult R(SemaRef, Name, NameLoc, Sema::LookupMemberName,
4827 Sema::ForVisibleRedeclaration);
4828 if (!SemaRef.LookupName(R, S)) return false;
4829
4830 // Pick a representative declaration.
4831 NamedDecl *PrevDecl = R.getRepresentativeDecl()->getUnderlyingDecl();
4832 assert(PrevDecl && "Expected a non-null Decl")((PrevDecl && "Expected a non-null Decl") ? static_cast
<void> (0) : __assert_fail ("PrevDecl && \"Expected a non-null Decl\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 4832, __PRETTY_FUNCTION__))
;
4833
4834 if (!SemaRef.isDeclInScope(PrevDecl, Owner, S))
4835 return false;
4836
4837 SemaRef.Diag(NameLoc, diag::err_anonymous_record_member_redecl)
4838 << IsUnion << Name;
4839 SemaRef.Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
4840
4841 return true;
4842}
4843
4844/// InjectAnonymousStructOrUnionMembers - Inject the members of the
4845/// anonymous struct or union AnonRecord into the owning context Owner
4846/// and scope S. This routine will be invoked just after we realize
4847/// that an unnamed union or struct is actually an anonymous union or
4848/// struct, e.g.,
4849///
4850/// @code
4851/// union {
4852/// int i;
4853/// float f;
4854/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and
4855/// // f into the surrounding scope.x
4856/// @endcode
4857///
4858/// This routine is recursive, injecting the names of nested anonymous
4859/// structs/unions into the owning context and scope as well.
4860static bool
4861InjectAnonymousStructOrUnionMembers(Sema &SemaRef, Scope *S, DeclContext *Owner,
4862 RecordDecl *AnonRecord, AccessSpecifier AS,
4863 SmallVectorImpl<NamedDecl *> &Chaining) {
4864 bool Invalid = false;
4865
4866 // Look every FieldDecl and IndirectFieldDecl with a name.
4867 for (auto *D : AnonRecord->decls()) {
4868 if ((isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D)) &&
4869 cast<NamedDecl>(D)->getDeclName()) {
4870 ValueDecl *VD = cast<ValueDecl>(D);
4871 if (CheckAnonMemberRedeclaration(SemaRef, S, Owner, VD->getDeclName(),
4872 VD->getLocation(),
4873 AnonRecord->isUnion())) {
4874 // C++ [class.union]p2:
4875 // The names of the members of an anonymous union shall be
4876 // distinct from the names of any other entity in the
4877 // scope in which the anonymous union is declared.
4878 Invalid = true;
4879 } else {
4880 // C++ [class.union]p2:
4881 // For the purpose of name lookup, after the anonymous union
4882 // definition, the members of the anonymous union are
4883 // considered to have been defined in the scope in which the
4884 // anonymous union is declared.
4885 unsigned OldChainingSize = Chaining.size();
4886 if (IndirectFieldDecl *IF = dyn_cast<IndirectFieldDecl>(VD))
4887 Chaining.append(IF->chain_begin(), IF->chain_end());
4888 else
4889 Chaining.push_back(VD);
4890
4891 assert(Chaining.size() >= 2)((Chaining.size() >= 2) ? static_cast<void> (0) : __assert_fail
("Chaining.size() >= 2", "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 4891, __PRETTY_FUNCTION__))
;
4892 NamedDecl **NamedChain =
4893 new (SemaRef.Context)NamedDecl*[Chaining.size()];
4894 for (unsigned i = 0; i < Chaining.size(); i++)
4895 NamedChain[i] = Chaining[i];
4896
4897 IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
4898 SemaRef.Context, Owner, VD->getLocation(), VD->getIdentifier(),
4899 VD->getType(), {NamedChain, Chaining.size()});
4900
4901 for (const auto *Attr : VD->attrs())
4902 IndirectField->addAttr(Attr->clone(SemaRef.Context));
4903
4904 IndirectField->setAccess(AS);
4905 IndirectField->setImplicit();
4906 SemaRef.PushOnScopeChains(IndirectField, S);
4907
4908 // That includes picking up the appropriate access specifier.
4909 if (AS != AS_none) IndirectField->setAccess(AS);
4910
4911 Chaining.resize(OldChainingSize);
4912 }
4913 }
4914 }
4915
4916 return Invalid;
4917}
4918
4919/// StorageClassSpecToVarDeclStorageClass - Maps a DeclSpec::SCS to
4920/// a VarDecl::StorageClass. Any error reporting is up to the caller:
4921/// illegal input values are mapped to SC_None.
4922static StorageClass
4923StorageClassSpecToVarDeclStorageClass(const DeclSpec &DS) {
4924 DeclSpec::SCS StorageClassSpec = DS.getStorageClassSpec();
4925 assert(StorageClassSpec != DeclSpec::SCS_typedef &&((StorageClassSpec != DeclSpec::SCS_typedef && "Parser allowed 'typedef' as storage class VarDecl."
) ? static_cast<void> (0) : __assert_fail ("StorageClassSpec != DeclSpec::SCS_typedef && \"Parser allowed 'typedef' as storage class VarDecl.\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 4926, __PRETTY_FUNCTION__))
4926 "Parser allowed 'typedef' as storage class VarDecl.")((StorageClassSpec != DeclSpec::SCS_typedef && "Parser allowed 'typedef' as storage class VarDecl."
) ? static_cast<void> (0) : __assert_fail ("StorageClassSpec != DeclSpec::SCS_typedef && \"Parser allowed 'typedef' as storage class VarDecl.\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 4926, __PRETTY_FUNCTION__))
;
4927 switch (StorageClassSpec) {
4928 case DeclSpec::SCS_unspecified: return SC_None;
4929 case DeclSpec::SCS_extern:
4930 if (DS.isExternInLinkageSpec())
4931 return SC_None;
4932 return SC_Extern;
4933 case DeclSpec::SCS_static: return SC_Static;
4934 case DeclSpec::SCS_auto: return SC_Auto;
4935 case DeclSpec::SCS_register: return SC_Register;
4936 case DeclSpec::SCS_private_extern: return SC_PrivateExtern;
4937 // Illegal SCSs map to None: error reporting is up to the caller.
4938 case DeclSpec::SCS_mutable: // Fall through.
4939 case DeclSpec::SCS_typedef: return SC_None;
4940 }
4941 llvm_unreachable("unknown storage class specifier")::llvm::llvm_unreachable_internal("unknown storage class specifier"
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 4941)
;
4942}
4943
4944static SourceLocation findDefaultInitializer(const CXXRecordDecl *Record) {
4945 assert(Record->hasInClassInitializer())((Record->hasInClassInitializer()) ? static_cast<void>
(0) : __assert_fail ("Record->hasInClassInitializer()", "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 4945, __PRETTY_FUNCTION__))
;
4946
4947 for (const auto *I : Record->decls()) {
4948 const auto *FD = dyn_cast<FieldDecl>(I);
4949 if (const auto *IFD = dyn_cast<IndirectFieldDecl>(I))
4950 FD = IFD->getAnonField();
4951 if (FD && FD->hasInClassInitializer())
4952 return FD->getLocation();
4953 }
4954
4955 llvm_unreachable("couldn't find in-class initializer")::llvm::llvm_unreachable_internal("couldn't find in-class initializer"
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 4955)
;
4956}
4957
4958static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent,
4959 SourceLocation DefaultInitLoc) {
4960 if (!Parent->isUnion() || !Parent->hasInClassInitializer())
4961 return;
4962
4963 S.Diag(DefaultInitLoc, diag::err_multiple_mem_union_initialization);
4964 S.Diag(findDefaultInitializer(Parent), diag::note_previous_initializer) << 0;
4965}
4966
4967static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent,
4968 CXXRecordDecl *AnonUnion) {
4969 if (!Parent->isUnion() || !Parent->hasInClassInitializer())
4970 return;
4971
4972 checkDuplicateDefaultInit(S, Parent, findDefaultInitializer(AnonUnion));
4973}
4974
4975/// BuildAnonymousStructOrUnion - Handle the declaration of an
4976/// anonymous structure or union. Anonymous unions are a C++ feature
4977/// (C++ [class.union]) and a C11 feature; anonymous structures
4978/// are a C11 feature and GNU C++ extension.
4979Decl *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
4980 AccessSpecifier AS,
4981 RecordDecl *Record,
4982 const PrintingPolicy &Policy) {
4983 DeclContext *Owner = Record->getDeclContext();
4984
4985 // Diagnose whether this anonymous struct/union is an extension.
4986 if (Record->isUnion() && !getLangOpts().CPlusPlus && !getLangOpts().C11)
4987 Diag(Record->getLocation(), diag::ext_anonymous_union);
4988 else if (!Record->isUnion() && getLangOpts().CPlusPlus)
4989 Diag(Record->getLocation(), diag::ext_gnu_anonymous_struct);
4990 else if (!Record->isUnion() && !getLangOpts().C11)
4991 Diag(Record->getLocation(), diag::ext_c11_anonymous_struct);
4992
4993 // C and C++ require different kinds of checks for anonymous
4994 // structs/unions.
4995 bool Invalid = false;
4996 if (getLangOpts().CPlusPlus) {
4997 const char *PrevSpec = nullptr;
4998 if (Record->isUnion()) {
4999 // C++ [class.union]p6:
5000 // C++17 [class.union.anon]p2:
5001 // Anonymous unions declared in a named namespace or in the
5002 // global namespace shall be declared static.
5003 unsigned DiagID;
5004 DeclContext *OwnerScope = Owner->getRedeclContext();
5005 if (DS.getStorageClassSpec() != DeclSpec::SCS_static &&
5006 (OwnerScope->isTranslationUnit() ||
5007 (OwnerScope->isNamespace() &&
5008 !cast<NamespaceDecl>(OwnerScope)->isAnonymousNamespace()))) {
5009 Diag(Record->getLocation(), diag::err_anonymous_union_not_static)
5010 << FixItHint::CreateInsertion(Record->getLocation(), "static ");
5011
5012 // Recover by adding 'static'.
5013 DS.SetStorageClassSpec(*this, DeclSpec::SCS_static, SourceLocation(),
5014 PrevSpec, DiagID, Policy);
5015 }
5016 // C++ [class.union]p6:
5017 // A storage class is not allowed in a declaration of an
5018 // anonymous union in a class scope.
5019 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
5020 isa<RecordDecl>(Owner)) {
5021 Diag(DS.getStorageClassSpecLoc(),
5022 diag::err_anonymous_union_with_storage_spec)
5023 << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
5024
5025 // Recover by removing the storage specifier.
5026 DS.SetStorageClassSpec(*this, DeclSpec::SCS_unspecified,
5027 SourceLocation(),
5028 PrevSpec, DiagID, Context.getPrintingPolicy());
5029 }
5030 }
5031
5032 // Ignore const/volatile/restrict qualifiers.
5033 if (DS.getTypeQualifiers()) {
5034 if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
5035 Diag(DS.getConstSpecLoc(), diag::ext_anonymous_struct_union_qualified)
5036 << Record->isUnion() << "const"
5037 << FixItHint::CreateRemoval(DS.getConstSpecLoc());
5038 if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
5039 Diag(DS.getVolatileSpecLoc(),
5040 diag::ext_anonymous_struct_union_qualified)
5041 << Record->isUnion() << "volatile"
5042 << FixItHint::CreateRemoval(DS.getVolatileSpecLoc());
5043 if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
5044 Diag(DS.getRestrictSpecLoc(),
5045 diag::ext_anonymous_struct_union_qualified)
5046 << Record->isUnion() << "restrict"
5047 << FixItHint::CreateRemoval(DS.getRestrictSpecLoc());
5048 if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
5049 Diag(DS.getAtomicSpecLoc(),
5050 diag::ext_anonymous_struct_union_qualified)
5051 << Record->isUnion() << "_Atomic"
5052 << FixItHint::CreateRemoval(DS.getAtomicSpecLoc());
5053 if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
5054 Diag(DS.getUnalignedSpecLoc(),
5055 diag::ext_anonymous_struct_union_qualified)
5056 << Record->isUnion() << "__unaligned"
5057 << FixItHint::CreateRemoval(DS.getUnalignedSpecLoc());
5058
5059 DS.ClearTypeQualifiers();
5060 }
5061
5062 // C++ [class.union]p2:
5063 // The member-specification of an anonymous union shall only
5064 // define non-static data members. [Note: nested types and
5065 // functions cannot be declared within an anonymous union. ]
5066 for (auto *Mem : Record->decls()) {
5067 // Ignore invalid declarations; we already diagnosed them.
5068 if (Mem->isInvalidDecl())
5069 continue;
5070
5071 if (auto *FD = dyn_cast<FieldDecl>(Mem)) {
5072 // C++ [class.union]p3:
5073 // An anonymous union shall not have private or protected
5074 // members (clause 11).
5075 assert(FD->getAccess() != AS_none)((FD->getAccess() != AS_none) ? static_cast<void> (0
) : __assert_fail ("FD->getAccess() != AS_none", "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 5075, __PRETTY_FUNCTION__))
;
5076 if (FD->getAccess() != AS_public) {
5077 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member)
5078 << Record->isUnion() << (FD->getAccess() == AS_protected);
5079 Invalid = true;
5080 }
5081
5082 // C++ [class.union]p1
5083 // An object of a class with a non-trivial constructor, a non-trivial
5084 // copy constructor, a non-trivial destructor, or a non-trivial copy
5085 // assignment operator cannot be a member of a union, nor can an
5086 // array of such objects.
5087 if (CheckNontrivialField(FD))
5088 Invalid = true;
5089 } else if (Mem->isImplicit()) {
5090 // Any implicit members are fine.
5091 } else if (isa<TagDecl>(Mem) && Mem->getDeclContext() != Record) {
5092 // This is a type that showed up in an
5093 // elaborated-type-specifier inside the anonymous struct or
5094 // union, but which actually declares a type outside of the
5095 // anonymous struct or union. It's okay.
5096 } else if (auto *MemRecord = dyn_cast<RecordDecl>(Mem)) {
5097 if (!MemRecord->isAnonymousStructOrUnion() &&
5098 MemRecord->getDeclName()) {
5099 // Visual C++ allows type definition in anonymous struct or union.
5100 if (getLangOpts().MicrosoftExt)
5101 Diag(MemRecord->getLocation(), diag::ext_anonymous_record_with_type)
5102 << Record->isUnion();
5103 else {
5104 // This is a nested type declaration.
5105 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type)
5106 << Record->isUnion();
5107 Invalid = true;
5108 }
5109 } else {
5110 // This is an anonymous type definition within another anonymous type.
5111 // This is a popular extension, provided by Plan9, MSVC and GCC, but
5112 // not part of standard C++.
5113 Diag(MemRecord->getLocation(),
5114 diag::ext_anonymous_record_with_anonymous_type)
5115 << Record->isUnion();
5116 }
5117 } else if (isa<AccessSpecDecl>(Mem)) {
5118 // Any access specifier is fine.
5119 } else if (isa<StaticAssertDecl>(Mem)) {
5120 // In C++1z, static_assert declarations are also fine.
5121 } else {
5122 // We have something that isn't a non-static data
5123 // member. Complain about it.
5124 unsigned DK = diag::err_anonymous_record_bad_member;
5125 if (isa<TypeDecl>(Mem))
5126 DK = diag::err_anonymous_record_with_type;
5127 else if (isa<FunctionDecl>(Mem))
5128 DK = diag::err_anonymous_record_with_function;
5129 else if (isa<VarDecl>(Mem))
5130 DK = diag::err_anonymous_record_with_static;
5131
5132 // Visual C++ allows type definition in anonymous struct or union.
5133 if (getLangOpts().MicrosoftExt &&
5134 DK == diag::err_anonymous_record_with_type)
5135 Diag(Mem->getLocation(), diag::ext_anonymous_record_with_type)
5136 << Record->isUnion();
5137 else {
5138 Diag(Mem->getLocation(), DK) << Record->isUnion();
5139 Invalid = true;
5140 }
5141 }
5142 }
5143
5144 // C++11 [class.union]p8 (DR1460):
5145 // At most one variant member of a union may have a
5146 // brace-or-equal-initializer.
5147 if (cast<CXXRecordDecl>(Record)->hasInClassInitializer() &&
5148 Owner->isRecord())
5149 checkDuplicateDefaultInit(*this, cast<CXXRecordDecl>(Owner),
5150 cast<CXXRecordDecl>(Record));
5151 }
5152
5153 if (!Record->isUnion() && !Owner->isRecord()) {
5154 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member)
5155 << getLangOpts().CPlusPlus;
5156 Invalid = true;
5157 }
5158
5159 // C++ [dcl.dcl]p3:
5160 // [If there are no declarators], and except for the declaration of an
5161 // unnamed bit-field, the decl-specifier-seq shall introduce one or more
5162 // names into the program
5163 // C++ [class.mem]p2:
5164 // each such member-declaration shall either declare at least one member
5165 // name of the class or declare at least one unnamed bit-field
5166 //
5167 // For C this is an error even for a named struct, and is diagnosed elsewhere.
5168 if (getLangOpts().CPlusPlus && Record->field_empty())
5169 Diag(DS.getBeginLoc(), diag::ext_no_declarators) << DS.getSourceRange();
5170
5171 // Mock up a declarator.
5172 Declarator Dc(DS, DeclaratorContext::Member);
5173 TypeSourceInfo *TInfo = GetTypeForDeclarator(Dc, S);
5174 assert(TInfo && "couldn't build declarator info for anonymous struct/union")((TInfo && "couldn't build declarator info for anonymous struct/union"
) ? static_cast<void> (0) : __assert_fail ("TInfo && \"couldn't build declarator info for anonymous struct/union\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 5174, __PRETTY_FUNCTION__))
;
5175
5176 // Create a declaration for this anonymous struct/union.
5177 NamedDecl *Anon = nullptr;
5178 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) {
5179 Anon = FieldDecl::Create(
5180 Context, OwningClass, DS.getBeginLoc(), Record->getLocation(),
5181 /*IdentifierInfo=*/nullptr, Context.getTypeDeclType(Record), TInfo,
5182 /*BitWidth=*/nullptr, /*Mutable=*/false,
5183 /*InitStyle=*/ICIS_NoInit);
5184 Anon->setAccess(AS);
5185 ProcessDeclAttributes(S, Anon, Dc);
5186
5187 if (getLangOpts().CPlusPlus)
5188 FieldCollector->Add(cast<FieldDecl>(Anon));
5189 } else {
5190 DeclSpec::SCS SCSpec = DS.getStorageClassSpec();
5191 StorageClass SC = StorageClassSpecToVarDeclStorageClass(DS);
5192 if (SCSpec == DeclSpec::SCS_mutable) {
5193 // mutable can only appear on non-static class members, so it's always
5194 // an error here
5195 Diag(Record->getLocation(), diag::err_mutable_nonmember);
5196 Invalid = true;
5197 SC = SC_None;
5198 }
5199
5200 assert(DS.getAttributes().empty() && "No attribute expected")((DS.getAttributes().empty() && "No attribute expected"
) ? static_cast<void> (0) : __assert_fail ("DS.getAttributes().empty() && \"No attribute expected\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 5200, __PRETTY_FUNCTION__))
;
5201 Anon = VarDecl::Create(Context, Owner, DS.getBeginLoc(),
5202 Record->getLocation(), /*IdentifierInfo=*/nullptr,
5203 Context.getTypeDeclType(Record), TInfo, SC);
5204
5205 // Default-initialize the implicit variable. This initialization will be
5206 // trivial in almost all cases, except if a union member has an in-class
5207 // initializer:
5208 // union { int n = 0; };
5209 ActOnUninitializedDecl(Anon);
5210 }
5211 Anon->setImplicit();
5212
5213 // Mark this as an anonymous struct/union type.
5214 Record->setAnonymousStructOrUnion(true);
5215
5216 // Add the anonymous struct/union object to the current
5217 // context. We'll be referencing this object when we refer to one of
5218 // its members.
5219 Owner->addDecl(Anon);
5220
5221 // Inject the members of the anonymous struct/union into the owning
5222 // context and into the identifier resolver chain for name lookup
5223 // purposes.
5224 SmallVector<NamedDecl*, 2> Chain;
5225 Chain.push_back(Anon);
5226
5227 if (InjectAnonymousStructOrUnionMembers(*this, S, Owner, Record, AS, Chain))
5228 Invalid = true;
5229
5230 if (VarDecl *NewVD = dyn_cast<VarDecl>(Anon)) {
5231 if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
5232 MangleNumberingContext *MCtx;
5233 Decl *ManglingContextDecl;
5234 std::tie(MCtx, ManglingContextDecl) =
5235 getCurrentMangleNumberContext(NewVD->getDeclContext());
5236 if (MCtx) {
5237 Context.setManglingNumber(
5238 NewVD, MCtx->getManglingNumber(
5239 NewVD, getMSManglingNumber(getLangOpts(), S)));
5240 Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD));
5241 }
5242 }
5243 }
5244
5245 if (Invalid)
5246 Anon->setInvalidDecl();
5247
5248 return Anon;
5249}
5250
5251/// BuildMicrosoftCAnonymousStruct - Handle the declaration of an
5252/// Microsoft C anonymous structure.
5253/// Ref: http://msdn.microsoft.com/en-us/library/z2cx9y4f.aspx
5254/// Example:
5255///
5256/// struct A { int a; };
5257/// struct B { struct A; int b; };
5258///
5259/// void foo() {
5260/// B var;
5261/// var.a = 3;
5262/// }
5263///
5264Decl *Sema::BuildMicrosoftCAnonymousStruct(Scope *S, DeclSpec &DS,
5265 RecordDecl *Record) {
5266 assert(Record && "expected a record!")((Record && "expected a record!") ? static_cast<void
> (0) : __assert_fail ("Record && \"expected a record!\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 5266, __PRETTY_FUNCTION__))
;
5267
5268 // Mock up a declarator.
5269 Declarator Dc(DS, DeclaratorContext::TypeName);
5270 TypeSourceInfo *TInfo = GetTypeForDeclarator(Dc, S);
5271 assert(TInfo && "couldn't build declarator info for anonymous struct")((TInfo && "couldn't build declarator info for anonymous struct"
) ? static_cast<void> (0) : __assert_fail ("TInfo && \"couldn't build declarator info for anonymous struct\""
, "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 5271, __PRETTY_FUNCTION__))
;
5272
5273 auto *ParentDecl = cast<RecordDecl>(CurContext);
5274 QualType RecTy = Context.getTypeDeclType(Record);
5275
5276 // Create a declaration for this anonymous struct.
5277 NamedDecl *Anon =
5278 FieldDecl::Create(Context, ParentDecl, DS.getBeginLoc(), DS.getBeginLoc(),
5279 /*IdentifierInfo=*/nullptr, RecTy, TInfo,
5280 /*BitWidth=*/nullptr, /*Mutable=*/false,
5281 /*InitStyle=*/ICIS_NoInit);
5282 Anon->setImplicit();
5283
5284 // Add the anonymous struct object to the current context.
5285 CurContext->addDecl(Anon);
5286
5287 // Inject the members of the anonymous struct into the current
5288 // context and into the identifier resolver chain for name lookup
5289 // purposes.
5290 SmallVector<NamedDecl*, 2> Chain;
5291 Chain.push_back(Anon);
5292
5293 RecordDecl *RecordDef = Record->getDefinition();
5294 if (RequireCompleteSizedType(Anon->getLocation(), RecTy,
5295 diag::err_field_incomplete_or_sizeless) ||
5296 InjectAnonymousStructOrUnionMembers(*this, S, CurContext, RecordDef,
5297 AS_none, Chain)) {
5298 Anon->setInvalidDecl();
5299 ParentDecl->setInvalidDecl();
5300 }
5301
5302 return Anon;
5303}
5304
5305/// GetNameForDeclarator - Determine the full declaration name for the
5306/// given Declarator.
5307DeclarationNameInfo Sema::GetNameForDeclarator(Declarator &D) {
5308 return GetNameFromUnqualifiedId(D.getName());
5309}
5310
5311/// Retrieves the declaration name from a parsed unqualified-id.
5312DeclarationNameInfo
5313Sema::GetNameFromUnqualifiedId(const UnqualifiedId &Name) {
5314 DeclarationNameInfo NameInfo;
5315 NameInfo.setLoc(Name.StartLocation);
5316
5317 switch (Name.getKind()) {
5318
5319 case UnqualifiedIdKind::IK_ImplicitSelfParam:
5320 case UnqualifiedIdKind::IK_Identifier:
5321 NameInfo.setName(Name.Identifier);
5322 return NameInfo;
5323
5324 case UnqualifiedIdKind::IK_DeductionGuideName: {
5325 // C++ [temp.deduct.guide]p3:
5326 // The simple-template-id shall name a class template specialization.
5327 // The template-name shall be the same identifier as the template-name
5328 // of the simple-template-id.
5329 // These together intend to imply that the template-name shall name a
5330 // class template.
5331 // FIXME: template<typename T> struct X {};
5332 // template<typename T> using Y = X<T>;
5333 // Y(int) -> Y<int>;
5334 // satisfies these rules but does not name a class template.
5335 TemplateName TN = Name.TemplateName.get().get();
5336 auto *Template = TN.getAsTemplateDecl();
5337 if (!Template || !isa<ClassTemplateDecl>(Template)) {
5338 Diag(Name.StartLocation,
5339 diag::err_deduction_guide_name_not_class_template)
5340 << (int)getTemplateNameKindForDiagnostics(TN) << TN;
5341 if (Template)
5342 Diag(Template->getLocation(), diag::note_template_decl_here);
5343 return DeclarationNameInfo();
5344 }
5345
5346 NameInfo.setName(
5347 Context.DeclarationNames.getCXXDeductionGuideName(Template));
5348 return NameInfo;
5349 }
5350
5351 case UnqualifiedIdKind::IK_OperatorFunctionId:
5352 NameInfo.setName(Context.DeclarationNames.getCXXOperatorName(
5353 Name.OperatorFunctionId.Operator));
5354 NameInfo.setCXXOperatorNameRange(SourceRange(
5355 Name.OperatorFunctionId.SymbolLocations[0], Name.EndLocation));
5356 return NameInfo;
5357
5358 case UnqualifiedIdKind::IK_LiteralOperatorId:
5359 NameInfo.setName(Context.DeclarationNames.getCXXLiteralOperatorName(
5360 Name.Identifier));
5361 NameInfo.setCXXLiteralOperatorNameLoc(Name.EndLocation);
5362 return NameInfo;
5363
5364 case UnqualifiedIdKind::IK_ConversionFunctionId: {
5365 TypeSourceInfo *TInfo;
5366 QualType Ty = GetTypeFromParser(Name.ConversionFunctionId, &TInfo);
5367 if (Ty.isNull())
5368 return DeclarationNameInfo();
5369 NameInfo.setName(Context.DeclarationNames.getCXXConversionFunctionName(
5370 Context.getCanonicalType(Ty)));
5371 NameInfo.setNamedTypeInfo(TInfo);
5372 return NameInfo;
5373 }
5374
5375 case UnqualifiedIdKind::IK_ConstructorName: {
5376 TypeSourceInfo *TInfo;
5377 QualType Ty = GetTypeFromParser(Name.ConstructorName, &TInfo);
5378 if (Ty.isNull())
5379 return DeclarationNameInfo();
5380 NameInfo.setName(Context.DeclarationNames.getCXXConstructorName(
5381 Context.getCanonicalType(Ty)));
5382 NameInfo.setNamedTypeInfo(TInfo);
5383 return NameInfo;
5384 }
5385
5386 case UnqualifiedIdKind::IK_ConstructorTemplateId: {
5387 // In well-formed code, we can only have a constructor
5388 // template-id that refers to the current context, so go there
5389 // to find the actual type being constructed.
5390 CXXRecordDecl *CurClass = dyn_cast<CXXRecordDecl>(CurContext);
5391 if (!CurClass || CurClass->getIdentifier() != Name.TemplateId->Name)
5392 return DeclarationNameInfo();
5393
5394 // Determine the type of the class being constructed.
5395 QualType CurClassType = Context.getTypeDeclType(CurClass);
5396
5397 // FIXME: Check two things: that the template-id names the same type as
5398 // CurClassType, and that the template-id does not occur when the name
5399 // was qualified.
5400
5401 NameInfo.setName(Context.DeclarationNames.getCXXConstructorName(
5402 Context.getCanonicalType(CurClassType)));
5403 // FIXME: should we retrieve TypeSourceInfo?
5404 NameInfo.setNamedTypeInfo(nullptr);
5405 return NameInfo;
5406 }
5407
5408 case UnqualifiedIdKind::IK_DestructorName: {
5409 TypeSourceInfo *TInfo;
5410 QualType Ty = GetTypeFromParser(Name.DestructorName, &TInfo);
5411 if (Ty.isNull())
5412 return DeclarationNameInfo();
5413 NameInfo.setName(Context.DeclarationNames.getCXXDestructorName(
5414 Context.getCanonicalType(Ty)));
5415 NameInfo.setNamedTypeInfo(TInfo);
5416 return NameInfo;
5417 }
5418
5419 case UnqualifiedIdKind::IK_TemplateId: {
5420 TemplateName TName = Name.TemplateId->Template.get();
5421 SourceLocation TNameLoc = Name.TemplateId->TemplateNameLoc;
5422 return Context.getNameForTemplate(TName, TNameLoc);
5423 }
5424
5425 } // switch (Name.getKind())
5426
5427 llvm_unreachable("Unknown name kind")::llvm::llvm_unreachable_internal("Unknown name kind", "/build/llvm-toolchain-snapshot-13~++20210223111116+16ede0956cb1/clang/lib/Sema/SemaDecl.cpp"
, 5427)
;
5428}
5429
5430static QualType getCoreType(QualType Ty) {
5431 do {
5432 if (Ty->isPointerType() || Ty->isReferenceType())
5433 Ty = Ty->getPointeeType();
5434 else if (Ty->isArrayType())
5435 Ty = Ty->castAsArrayTypeUnsafe()->getElementType();
5436 else
5437 return Ty.withoutLocalFastQualifiers();
5438 } while (true);
5439}
5440
5441/// hasSimilarParameters - Determine whether the C++ functions Declaration
5442/// and Definition have "nearly" matching parameters. This heuristic is
5443/// used to improve diagnostics in the case where an out-of-line function
5444/// definition doesn't match any declaration within the class or namespace.
5445/// Also sets Params to the list of indices to the parameters that differ
5446/// between the declaration and the definition. If hasSimilarParameters
5447/// returns true and Params is empty, then all of the parameters match.
5448static bool hasSimilarParameters(ASTContext &Context,
5449 FunctionDecl *Declaration,
5450 FunctionDecl *Definition,
5451 SmallVectorImpl<unsigned> &Params) {
5452 Params.clear();
5453 if (Declaration->param_size() != Definition->param_size())
5454 return false;
5455 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) {
5456 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType();
5457 QualType DefParamTy = Definition->getParamDecl(Idx)->getType();
5458
5459 // The parameter types are identical
5460 if (Context.hasSameUnqualifiedType(DefParamTy, DeclParamTy))
5461 continue;
5462
5463 QualType DeclParamBaseTy = getCoreType(DeclParamTy);
5464 QualType DefParamBaseTy = getCoreType(DefParamTy);
5465 const IdentifierInfo *DeclTyName = DeclParamBaseTy.getBaseTypeIdentifier();
5466 const IdentifierInfo *DefTyName = DefParamBaseTy.getBaseTypeIdentifier();
5467
5468 if (Context.hasSameUnqualifiedType(DeclParamBaseTy, DefParamBaseTy) ||
5469 (DeclTyName && DeclTyName == DefTyName))
5470 Params.push_back(Idx);
5471 else // The two parameters aren't even close
5472 return false;
5473 }
5474
5475 return true;
5476}
5477
5478/// NeedsRebuildingInCurrentInstantiation - Checks whether the given
5479/// declarator needs to be rebuilt in the current instantiation.
5480/// Any bits of declarator which appear before the name are valid for
5481/// consideration here. That's specifically the type in the decl spec
5482/// and the base type in any member-pointer chunks.
5483static bool RebuildDeclaratorInCurrentInstantiation(Sema &S, Declarator &D,
5484 DeclarationName Name) {
5485 // The types we specifically need to rebuild are:
5486 // - typenames, typeofs, and decltypes
5487 // - types which will become injected class names
5488 // Of course, we also need to rebuild any type referencing such a
5489 // type. It's safest to just say "dependent", but we call out a
5490 // few cases here.
5491
5492 DeclSpec &DS = D.getMutableDeclSpec();
5493 switch (DS.getTypeSpecType()) {
5494 case DeclSpec::TST_typename:
5495 case DeclSpec::TST_typeofType:
5496 case DeclSpec::TST_underlyingType:
5497 case DeclSpec::TST_atomic: {
5498 // Grab the type from the parser.
5499 TypeSourceInfo *TSI = nullptr;
5500 QualType T = S.GetTypeFromParser(DS.getRepAsType(), &TSI);
5501 if (T.isNull() || !T->isInstantiationDependentType()) break;
5502
5503 // Make sure there's a type source info. This isn't really much
5504 // of a waste; most dependent types should have type source info
5505 // attached already.
5506 if (!TSI)
5507 TSI = S.Context.getTrivialTypeSourceInfo(T, DS.getTypeSpecTypeLoc());
5508
5509 // Rebuild the type in the current instantiation.
5510 TSI = S.RebuildTypeInCurrentInstantiation(TSI, D.getIdentifierLoc(), Name);
5511 if (!TSI) return true;
5512
5513 // Store the new type back in the decl spec.
5514 ParsedType LocType = S.CreateParsedType(TSI->getType(), TSI);
5515 DS.UpdateTypeRep(LocType);
5516 break;
5517 }
5518
5519 case DeclSpec::TST_decltype:
5520 case DeclSpec::TST_typeofExpr: {
5521 Expr *E = DS.getRepAsExpr();
5522 ExprResult Result = S.RebuildExprInCurrentInstantiation(E);
5523 if (Result.isInvalid()) return true;
5524 DS.UpdateExprRep(Result.get());
5525 break;
5526 }
5527
5528 default:
5529 // Nothing to do for these decl specs.
5530 break;
5531 }
5532
5533 // It doesn't matter what order we do this in.
5534 for (unsigned I = 0, E = D.getNumTypeObjects(); I != E; ++I) {
5535 DeclaratorChunk &Chunk = D.getTypeObject(I);
5536
5537 // The only type information in the declarator which can come
5538 // before the declaration name is the base type of a member
5539 // pointer.
5540 if (Chunk.Kind != DeclaratorChunk::MemberPointer)
5541 continue;
5542
5543 // Rebuild the scope specifier in-place.
5544 CXXScopeSpec &SS = Chunk.Mem.Scope();
5545 if (S.RebuildNestedNameSpecifierInCurrentInstantiation(SS))
5546 return true;
5547 }
5548
5549 return false;
5550}
5551
5552Decl *Sema::ActOnDeclarator(Scope *S, Declarator &D) {
5553 D.setFunctionDefinitionKind(FunctionDefinitionKind::Declaration);
5554 Decl *Dcl = HandleDeclarator(S, D, MultiTemplateParamsArg());
5555
5556 if (OriginalLexicalContext && OriginalLexicalContext->isObjCContainer() &&
5557 Dcl && Dcl->getDeclContext()->isFileContext())
5558 Dcl->setTopLevelDeclInObjCContainer();
5559
5560 if (getLangOpts().OpenCL)
5561 setCurrentOpenCLExtensionForDecl(Dcl);
5562
5563 return Dcl;
5564}
5565
5566/// DiagnoseClassNameShadow - Implement C++ [class.mem]p13:
5567/// If T is the name of a class, then each of the following shall have a
5568/// name different from T:
5569/// - every static data member of class T;
5570/// - every member function of class T
5571/// - every member of class T that is itself a type;
5572/// \returns true if the declaration name violates these rules.
5573bool Sema::DiagnoseClassNameShadow(DeclContext *DC,
5574 DeclarationNameInfo NameInfo) {
5575 DeclarationName Name = NameInfo.getName();
5576
5577 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC);
5578 while (Record && Record->isAnonymousStructOrUnion())
5579 Record = dyn_cast<CXXRecordDecl>(Record->getParent());
5580 if (Record && Record->getIdentifier() && Record->getDeclName() == Name) {
5581 Diag(NameInfo.getLoc(), diag::err_member_name_of_class) << Name;
5582 return true;
5583 }
5584
5585 return false;
5586}
5587
5588/// Diagnose a declaration whose declarator-id has the given
5589/// nested-name-specifier.
5590///
5591/// \param SS The nested-name-specifier of the declarator-id.
5592///
5593/// \param DC The declaration context to which the nested-name-specifier
5594/// resolves.
5595///
5596/// \param Name The name of the entity being declared.
5597///
5598/// \param Loc The location of the name of the entity being declared.
5599///
5600/// \param IsTemplateId Whether the name is a (simple-)template-id, and thus
5601/// we're declaring an explicit / partial specialization / instantiation.
5602///
5603/// \returns true if we cannot safely recover from this error, false otherwise.
5604bool Sema::diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
5605 DeclarationName Name,
5606 SourceLocation Loc, bool IsTemplateId) {
5607 DeclContext *Cur = CurContext;
5608 while (isa<LinkageSpecDecl>(Cur) || isa<CapturedDecl>(Cur))
5609 Cur = Cur->getParent();
5610
5611 // If the user provided a superfluous scope specifier that refers back to the
5612 // class in which the entity is already declared, diagnose and ignore it.
5613 //
5614 // class X {
5615 // void X::f();
5616 // };
5617 //
5618 // Note, it was once ill-formed to give redundant qualification in all
5619 // contexts, but that rule was removed by DR482.
5620 if (Cur->Equals(DC)) {
5621 if (Cur->isRecord()) {
5622 Diag(Loc, LangOpts.MicrosoftExt ? diag::warn_member_extra_qualification
5623 : diag::err_member_extra_qualification)
5624 << Name << FixItHint::CreateRemoval(SS.getRange());
5625 SS.clear();
5626 } else {
5627 Diag(Loc, diag::warn_namespace_member_extra_qualification) << Name;
5628 }
5629 return false;
5630 }
5631
5632 // Check whether the qualifying scope encloses the scope of the original
5633 // declaration. For a template-id, we perform the checks in
5634 // CheckTemplateSpecializationScope.
5635 if (!Cur->Encloses(DC) && !IsTemplateId) {
5636 if (Cur->isRecord())
5637 Diag(Loc, diag::err_member_qualification)
5638 << Name << SS.getRange();
5639 else if (isa<TranslationUnitDecl>(DC))
5640 Diag(Loc, diag::err_invalid_declarator_global_scope)
5641 << Name << SS.getRange();
5642 else if (isa<FunctionDecl>(Cur))
5643 Diag(Loc, diag::err_invalid_declarator_in_function)
5644 << Name << SS.getRange();
5645 else if (isa<BlockDecl>(Cur))
5646 Diag(Loc, diag::err_invalid_declarator_in_block)
5647 << Name << SS.getRange();
5648 else
5649 Diag(Loc, diag::err_invalid_declarator_scope)
5650 << Name << cast<NamedDecl>(Cur) << cast<NamedDecl>(DC) << SS.getRange();
5651
5652 return true;
5653 }
5654
5655 if (Cur->isRecord()) {
5656 // Cannot qualify members within a class.
5657 Diag(Loc, diag::err_member_qualification)
5658 << Name << SS.getRange();
5659 SS.clear();
5660
5661 // C++ constructors and destructors with incorrect scopes can break
5662 // our AST invariants by having the wrong underlying types. If
5663 // that's the case, then drop this declaration entirely.
5664 if ((Name.getNameKind() == DeclarationName::CXXConstructorName ||
5665 Name.getNameKind() == DeclarationName::CXXDestructorName) &&
5666 !Context.hasSameType(Name.getCXXNameType(),
5667 Context.getTypeDeclType(cast<CXXRecordDecl>(Cur))))
5668 return true;
5669
5670 return false;
5671 }
5672
5673 // C++11 [dcl.meaning]p1:
5674 // [...] "The nested-name-specifier of the qualified declarator-id shall
5675 // not begin with a decltype-specifer"
5676 NestedNameSpecifierLoc SpecLoc(SS.getScopeRep(), SS.location_data());
5677 while (SpecLoc.getPrefix())
5678 SpecLoc = SpecLoc.getPrefix();
5679 if (dyn_cast_or_null<DecltypeType>(
5680 SpecLoc.getNestedNameSpecifier()->getAsType()))
5681 Diag(Loc, diag::err_decltype_in_declarator)
5682 << SpecLoc.getTypeLoc().getSourceRange();
5683
5684 return false;
5685}
5686
5687NamedDecl *Sema::HandleDeclarator(Scope *S, Declarator &D,
5688 MultiTemplateParamsArg TemplateParamLists) {
5689 // TODO: consider using NameInfo for diagnostic.
5690 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
5691 DeclarationName Name = NameInfo.getName();
5692
5693 // All of these full declarators require an identifier. If it doesn't have
5694 // one, the ParsedFreeStandingDeclSpec action should be used.
5695 if (D.isDecompositionDeclarator()) {
5696 return ActOnDecompositionDeclarator(S, D, TemplateParamLists);
5697 } else if (!Name) {
5698 if (!D.isInvalidType()) // Reject this if we think it is valid.
5699 Diag(D.getDeclSpec().getBeginLoc(), diag::err_declarator_need_ident)
5700 << D.getDeclSpec().getSourceRange() << D.getSourceRange();
5701 return nullptr;
5702 } else if (DiagnoseUnexpandedParameterPack(NameInfo, UPPC_DeclarationType))
5703 return nullptr;
5704
5705 // The scope passed in may not be a decl scope. Zip up the scope tree until
5706 // we find one that is.
5707 while ((S->getFlags() & Scope::DeclScope) == 0 ||
5708 (S->getFlags() & Scope::TemplateParamScope) != 0)
5709 S = S->getParent();
5710
5711 DeclContext *DC = CurContext;
5712 if (D.getCXXScopeSpec().isInvalid())
5713 D.setInvalidType();
5714 else if (D.getCXXScopeSpec().isSet()) {
5715 if (DiagnoseUnexpandedParameterPack(D.getCXXScopeSpec(),
5716 UPPC_DeclarationQualifier))
5717 return nullptr;
5718
5719 bool EnteringContext = !D.getDeclSpec().isFriendSpecified();
5720 DC = computeDeclContext(D.getCXXScopeSpec(), EnteringContext);
5721 if (!DC || isa<EnumDecl>(DC)) {
5722 // If we could not compute the declaration context, it's because the
5723 // declaration context is dependent but does not refer to a class,
5724 // class template, or class template partial specialization. Complain
5725 // and return early, to avoid the coming semantic disaster.
5726 Diag(D.getIdentifierLoc(),
5727 diag::err_template_qualified_declarator_no_match)
5728 << D.getCXXScopeSpec().getScopeRep()
5729 << D.getCXXScopeSpec().getRange();
5730 return nullptr;
5731 }
5732 bool IsDependentContext = DC->isDependentContext();
5733
5734 if (!IsDependentContext &&
5735 RequireCompleteDeclContext(D.getCXXScopeSpec(), DC))
5736 return nullptr;
5737
5738 // If a class is incomplete, do not parse entities inside it.
5739 if (isa<CXXRecordDecl>(DC) && !cast<CXXRecordDecl>(DC)->hasDefinition()) {
5740 Diag(D.getIdentifierLoc(),
5741 diag::err_member_def_undefined_record)
5742 << Name << DC << D.getCXXScopeSpec().getRange();
5743 return nullptr;
5744 }
5745 if (!D.getDeclSpec().isFriendSpecified()) {
5746 if (diagnoseQualifiedDeclaration(
5747 D.getCXXScopeSpec(), DC, Name, D.getIdentifierLoc(),
5748 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId)) {
5749 if (DC->isRecord())
5750 return nullptr;
5751
5752 D.setInvalidType();
5753 }
5754 }
5755
5756 // Check whether we need to rebuild the type of the given
5757 // declaration in the current instantiation.
5758 if (EnteringContext && IsDependentContext &&
5759 TemplateParamLists.size() != 0) {
5760 ContextRAII SavedContext(*this, DC);
5761 if (RebuildDeclaratorInCurrentInstantiation(*this, D, Name))
5762 D.setInvalidType();
5763 }
5764 }
5765
5766 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
5767 QualType R = TInfo->getType();
5768
5769 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
5770 UPPC_DeclarationType))
5771 D.setInvalidType();
5772
5773 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
5774 forRedeclarationInCurContext());
5775
5776 // See if this is a redefinition of a variable in the same scope.
5777 if (!D.getCXXScopeSpec().isSet()) {
5778 bool IsLinkageLookup = false;
5779 bool CreateBuiltins = false;
5780
5781 // If the declaration we're planning to build will be a function
5782 // or object with linkage, then look for another declaration with
5783 // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6).
5784 //
5785 // If the declaration we're planning to build will be declared with
5786 // external linkage in the translation unit, create any builtin with
5787 // the same name.
5788 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef)
5789 /* Do nothing*/;
5790 else if (CurContext->isFunctionOrMethod() &&
5791 (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern ||
5792 R->isFunctionType())) {
5793 IsLinkageLookup = true;
5794 CreateBuiltins =
5795 CurContext->getEnclosingNamespaceContext()->isTranslationUnit();
5796 } else if (CurContext->getRedeclContext()->isTranslationUnit() &&
5797 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static)
5798 CreateBuiltins = true;
5799
5800 if (IsLinkageLookup) {
5801 Previous.clear(LookupRedeclarationWithLinkage);
5802 Previous.setRedeclarationKind(ForExternalRedeclaration);
5803 }
5804
5805 LookupName(Previous, S, CreateBuiltins);
5806 } else { // Something like "int foo::x;"
5807 LookupQualifiedName(Previous, DC);
5808
5809 // C++ [dcl.meaning]p1:
5810 // When the declarator-id is qualified, the declaration shall refer to a
5811 // previously declared member of the class or namespace to which the
5812 // qualifier refers (or, in the case of a namespace, of an element of the
5813 // inline namespace set of that namespace (7.3.1)) or to a specialization
5814 // thereof; [...]
5815 //
5816 // Note that we already checked the context above, and that we do not have
5817 // enough information to make sure that Previous contains the declaration
5818 // we want to match. For example, given:
5819 //
5820 // class X {
5821 // void f();
5822 // void f(float);
5823 // };
5824 //
5825 // void X::f(int) { } // ill-formed
5826 //
5827 // In this case, Previous will point to the overload set
5828 // containing the two f's declared in X, but neither of them
5829 // matches.
5830
5831 // C++ [dcl.meaning]p1:
5832 // [...] the member shall not merely have been introduced by a
5833 // using-declaration in the scope of the class or namespace nominated by
5834 // the nested-name-specifier of the declarator-id.
5835 RemoveUsingDecls(Previous);
5836 }
5837
5838 if (Previous.isSingleResult() &&
5839 Previous.getFoundDecl()->isTemplateParameter()) {
5840 // Maybe we will complain about the shadowed template parameter.
5841 if (!D.isInvalidType())
5842 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
5843 Previous.getFoundDecl());
5844
5845 // Just pretend that we didn't see the previous declaration.
5846 Previous.clear();
5847 }
5848
5849 if (!R->isFunctionType() && DiagnoseClassNameShadow(DC, NameInfo))
5850 // Forget that the previous declaration is the injected-class-name.
5851 Previous.clear();
5852
5853 // In C++, the previous declaration we find might be a tag type
5854 // (class or enum). In this case, the new declaration will hide the
5855 // tag type. Note that this applies to functions, function templates, and
5856 // variables, but not to typedefs (C++ [dcl.typedef]p4) or variable templates.
5857 if (Previous.isSingleTagDecl() &&
5858 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
5859 (TemplateParamLists.size() == 0 || R->isFunctionType()))
5860 Previous.clear();
5861
5862 // Check that there are no default arguments other than in the parameters
5863 // of a function declaration (C++ only).
5864 if (getLangOpts().CPlusPlus)
5865 CheckExtraCXXDefaultArguments(D);
5866
5867 NamedDecl *New;
5868
5869 bool AddToScope = true;
5870 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
5871 if (TemplateParamLists.size()) {
5872 Diag(D.getIdentifierLoc(), diag::err_template_typedef);
5873 return nullptr;
5874 }
5875
5876 New = ActOnTypedefDeclarator(S, D, DC, TInfo, Previous);
5877 } else if (R->isFunctionType()) {
5878 New = ActOnFunctionDeclarator(S, D, DC, TInfo, Previous,
5879 TemplateParamLists,
5880 AddToScope);
5881 } else {
5882 New = ActOnVariableDeclarator(S, D, DC, TInfo, Previous, TemplateParamLists,
5883 AddToScope);
5884 }
5885
5886 if (!New)
5887 return nullptr;
5888
5889 // If this has an identifier and is not a function template specialization,
5890 // add it to the scope stack.
5891 if (New->getDeclName() && AddToScope)
5892 PushOnScopeChains(New, S);
5893
5894 if (isInOpenMPDeclareTargetContext())
5895 checkDeclIsAllowedInOpenMPTarget(nullptr, New);
5896
5897 return New;
5898}
5899
5900/// Helper method to turn variable array types into constant array
5901/// types in certain situations which would otherwise be errors (for
5902/// GCC compatibility).
5903static QualType TryToFixInvalidVariablyModifiedType(QualType T,
5904 ASTContext &Context,
5905 bool &SizeIsNegative,
5906 llvm::APSInt &Oversized) {
5907 // This method tries to turn a variable array into a constant
5908 // array even when the size isn't an ICE. This is necessary
5909 // for compatibility with code that depends on gcc's buggy
5910 // constant expression folding, like struct {char x[(int)(char*)2];}
5911 SizeIsNegative = false;
5912 Oversized = 0;
5913
5914 if (T->isDependentType())
5915 return QualType();
5916
5917 QualifierCollector Qs;
5918 const Type *Ty = Qs.strip(T);
5919
5920 if (const PointerType* PTy = dyn_cast<PointerType>(Ty)) {
5921 QualType Pointee = PTy->getPointeeType();
5922 QualType FixedType =
5923 TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative,
5924 Oversized);
5925 if (FixedType.isNull()) return FixedType;
5926 FixedType = Context.getPointerType(FixedType);
5927 return Qs.apply(Context, FixedType);
5928 }
5929 if (const ParenType* PTy = dyn_cast<ParenType>(Ty)) {
5930 QualType Inner = PTy->getInnerType();
5931 QualType FixedType =
5932 TryToFixInvalidVariablyModifiedType(Inner, Context, SizeIsNegative,
5933 Oversized);
5934 if (FixedType.isNull()) return FixedType;
5935 FixedType = Context.getParenType(FixedType);
5936 return Qs.apply(Context, FixedType);
5937 }
5938
5939 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T);
5940 if (!VLATy)
5941 return QualType();
5942
5943 QualType ElemTy = VLATy->getElementType();
5944 if (ElemTy->isVariablyModifiedType()) {
5945 ElemTy = TryToFixInvalidVariablyModifiedType(ElemTy, Context,
5946 SizeIsNegative, Oversized);
5947 if (ElemTy.isNull())
5948 return QualType();
5949 }
5950
5951 Expr::EvalResult Result;
5952 if (!VLATy->getSizeExpr() ||
5953 !VLATy->getSizeExpr()->EvaluateAsInt(Result, Context))
5954 return QualType();
5955
5956 llvm::APSInt Res = Result.Val.getInt();
5957
5958 // Check whether the array size is negative.
5959 if (Res.isSigned() && Res.isNegative()) {
5960 SizeIsNegative = true;
5961 return QualType();
5962 }
5963
5964 // Check whether the array is too large to be addressed.
5965 unsigned ActiveSizeBits =
5966 (!ElemTy->isDependentType() && !ElemTy->isVariablyModifiedType() &&
5967 !ElemTy->isIncompleteType() && !ElemTy->isUndeducedType())
5968 ? ConstantArrayType::getNumAddressingBits(Context, ElemTy, Res)
5969 : Res.getActiveBits();
5970 if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) {
5971 Oversized = Res;
5972 return QualType();
5973 }
5974
5975 QualType FoldedArrayType = Context.getConstantArrayType(
5976 ElemTy, Res, VLATy->getSizeExpr(), ArrayType::Normal, 0);
5977 return Qs.apply(Context, FoldedArrayType);
5978}
5979
5980static void
5981FixInvalidVariablyModifiedTypeLoc(TypeLoc SrcTL, TypeLoc DstTL) {
5982 SrcTL = SrcTL.getUnqualifiedLoc();
5983 DstTL = DstTL.getUnqualifiedLoc();
5984 if (PointerTypeLoc SrcPTL = SrcTL.getAs<PointerTypeLoc>()) {
5985 PointerTypeLoc DstPTL = DstTL.castAs<PointerTypeLoc>();
5986 FixInvalidVariablyModifiedTypeLoc(SrcPTL.getPointeeLoc(),
5987 DstPTL.getPointeeLoc());
5988 DstPTL.setStarLoc(SrcPTL.getStarLoc());
5989 return;
5990 }
5991 if (ParenTypeLoc SrcPTL = SrcTL.getAs<ParenTypeLoc>()) {
5992 ParenTypeLoc DstPTL = DstTL.castAs<ParenTypeLoc>();
5993 FixInvalidVariablyModifiedTypeLoc(SrcPTL.getInnerLoc(),
5994 DstPTL.getInnerLoc());
5995 DstPTL.setLParenLoc(SrcPTL.getLParenLoc());
5996 DstPTL.setRParenLoc(SrcPTL.getRParenLoc());
5997 return;
5998 }
5999 ArrayTypeLoc SrcATL = SrcTL.castAs<ArrayTypeLoc>();
6000 ArrayTypeLoc DstATL = DstTL.castAs<ArrayTypeLoc>();
6001 TypeLoc SrcElemTL = SrcATL.getElementLoc();
6002 TypeLoc DstElemTL = DstATL.getElementLoc();
6003 if (VariableArrayTypeLoc SrcElemATL =
6004 SrcElemTL.getAs<VariableArrayTypeLoc>()) {
6005 ConstantArrayTypeLoc DstElemATL = DstElemTL.castAs<ConstantArrayTypeLoc>();
6006 FixInvalidVariablyModifiedTypeLoc(SrcElemATL, DstElemATL);
6007 } else {
6008 DstElemTL.initializeFullCopy(SrcElemTL);
6009 }
6010 DstATL.setLBracketLoc(SrcATL.getLBracketLoc());
6011 DstATL.setSizeExpr(SrcATL.getSizeExpr());
6012 DstATL.setRBracketLoc(SrcATL.getRBracketLoc());
6013}
6014
6015/// Helper method to turn variable array types into constant array
6016/// types in certain situations which would otherwise be errors (for
6017/// GCC compatibility).
6018static TypeSourceInfo*
6019TryToFixInvalidVariablyModifiedTypeSourceInfo(TypeSourceInfo *TInfo,
6020 ASTContext &Context,
6021 bool &SizeIsNegative,
6022 llvm::APSInt &Oversized) {
6023 QualType FixedTy
6024 = TryToFixInvalidVariablyModifiedType(TInfo->getType(), Context,
6025 SizeIsNegative, Oversized);
6026 if (FixedTy.isNull())
6027 return nullptr;
6028 TypeSourceInfo *FixedTInfo = Context.getTrivialTypeSourceInfo(FixedTy);
6029 FixInvalidVariablyModifiedTypeLoc(TInfo->getTypeLoc(),
6030 FixedTInfo->getTypeLoc());
6031 return FixedTInfo;
6032}
6033
6034/// Attempt to fold a variable-sized type to a constant-sized type, returning
6035/// true if we were successful.
6036static bool tryToFixVariablyModifiedVarType(Sema &S, TypeSourceInfo *&TInfo,
6037 QualType &T, SourceLocation Loc,
6038 unsigned FailedFoldDiagID) {
6039 b