1 //===--- Sema.cpp - AST Builder and Semantic Analysis Implementation ------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the actions class which performs semantic analysis and
11 // builds an AST out of a parse stream.
13 //===----------------------------------------------------------------------===//
15 #include "clang/Sema/SemaInternal.h"
16 #include "clang/Sema/DelayedDiagnostic.h"
17 #include "TargetAttributesSema.h"
18 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/SmallSet.h"
20 #include "llvm/ADT/APFloat.h"
21 #include "llvm/Support/CrashRecoveryContext.h"
22 #include "clang/Sema/CXXFieldCollector.h"
23 #include "clang/Sema/TemplateDeduction.h"
24 #include "clang/Sema/ExternalSemaSource.h"
25 #include "clang/Sema/MultiplexExternalSemaSource.h"
26 #include "clang/Sema/ObjCMethodList.h"
27 #include "clang/Sema/PrettyDeclStackTrace.h"
28 #include "clang/Sema/Scope.h"
29 #include "clang/Sema/ScopeInfo.h"
30 #include "clang/Sema/SemaConsumer.h"
31 #include "clang/AST/ASTContext.h"
32 #include "clang/AST/ASTDiagnostic.h"
33 #include "clang/AST/DeclCXX.h"
34 #include "clang/AST/DeclFriend.h"
35 #include "clang/AST/DeclObjC.h"
36 #include "clang/AST/Expr.h"
37 #include "clang/AST/ExprCXX.h"
38 #include "clang/AST/StmtCXX.h"
39 #include "clang/Lex/HeaderSearch.h"
40 #include "clang/Lex/Preprocessor.h"
41 #include "clang/Basic/FileManager.h"
42 #include "clang/Basic/PartialDiagnostic.h"
43 #include "clang/Basic/TargetInfo.h"
44 using namespace clang;
47 PrintingPolicy Sema::getPrintingPolicy(const ASTContext &Context,
48 const Preprocessor &PP) {
49 PrintingPolicy Policy = Context.getPrintingPolicy();
50 Policy.Bool = Context.getLangOpts().Bool;
52 if (MacroInfo *BoolMacro = PP.getMacroInfo(&Context.Idents.get("bool"))) {
53 Policy.Bool = BoolMacro->isObjectLike() &&
54 BoolMacro->getNumTokens() == 1 &&
55 BoolMacro->getReplacementToken(0).is(tok::kw__Bool);
62 void Sema::ActOnTranslationUnitScope(Scope *S) {
64 PushDeclContext(S, Context.getTranslationUnitDecl());
66 VAListTagName = PP.getIdentifierInfo("__va_list_tag");
69 Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
70 TranslationUnitKind TUKind,
71 CodeCompleteConsumer *CodeCompleter)
72 : TheTargetAttributesSema(0), ExternalSource(0),
73 isMultiplexExternalSource(false), FPFeatures(pp.getLangOpts()),
74 LangOpts(pp.getLangOpts()), PP(pp), Context(ctxt), Consumer(consumer),
75 Diags(PP.getDiagnostics()), SourceMgr(PP.getSourceManager()),
76 CollectStats(false), CodeCompleter(CodeCompleter),
77 CurContext(0), OriginalLexicalContext(0),
78 PackContext(0), MSStructPragmaOn(false), VisContext(0),
79 IsBuildingRecoveryCallExpr(false),
80 ExprNeedsCleanups(false), LateTemplateParser(0), OpaqueParser(0),
81 IdResolver(pp), StdInitializerList(0), CXXTypeInfoDecl(0), MSVCGuidDecl(0),
83 NSStringDecl(0), StringWithUTF8StringMethod(0),
84 NSArrayDecl(0), ArrayWithObjectsMethod(0),
85 NSDictionaryDecl(0), DictionaryWithObjectsMethod(0),
86 GlobalNewDeleteDeclared(false),
88 NumSFINAEErrors(0), InFunctionDeclarator(0),
89 AccessCheckingSFINAE(false), InNonInstantiationSFINAEContext(false),
90 NonInstantiationEntries(0), ArgumentPackSubstitutionIndex(-1),
91 CurrentInstantiationScope(0), TyposCorrected(0),
92 AnalysisWarnings(*this)
96 LoadedExternalKnownNamespaces = false;
97 for (unsigned I = 0; I != NSAPI::NumNSNumberLiteralMethods; ++I)
98 NSNumberLiteralMethods[I] = 0;
100 if (getLangOpts().ObjC1)
101 NSAPIObj.reset(new NSAPI(Context));
103 if (getLangOpts().CPlusPlus)
104 FieldCollector.reset(new CXXFieldCollector());
106 // Tell diagnostics how to render things from the AST library.
107 PP.getDiagnostics().SetArgToStringFn(&FormatASTNodeDiagnosticArgument,
110 ExprEvalContexts.push_back(
111 ExpressionEvaluationContextRecord(PotentiallyEvaluated, 0,
114 FunctionScopes.push_back(new FunctionScopeInfo(Diags));
117 void Sema::Initialize() {
118 // Tell the AST consumer about this Sema object.
119 Consumer.Initialize(Context);
121 // FIXME: Isn't this redundant with the initialization above?
122 if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer))
123 SC->InitializeSema(*this);
125 // Tell the external Sema source about this Sema object.
126 if (ExternalSemaSource *ExternalSema
127 = dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource()))
128 ExternalSema->InitializeSema(*this);
130 // Initialize predefined 128-bit integer types, if needed.
131 if (PP.getTargetInfo().getPointerWidth(0) >= 64) {
132 // If either of the 128-bit integer types are unavailable to name lookup,
134 DeclarationName Int128 = &Context.Idents.get("__int128_t");
135 if (IdResolver.begin(Int128) == IdResolver.end())
136 PushOnScopeChains(Context.getInt128Decl(), TUScope);
138 DeclarationName UInt128 = &Context.Idents.get("__uint128_t");
139 if (IdResolver.begin(UInt128) == IdResolver.end())
140 PushOnScopeChains(Context.getUInt128Decl(), TUScope);
144 // Initialize predefined Objective-C types:
145 if (PP.getLangOpts().ObjC1) {
146 // If 'SEL' does not yet refer to any declarations, make it refer to the
148 DeclarationName SEL = &Context.Idents.get("SEL");
149 if (IdResolver.begin(SEL) == IdResolver.end())
150 PushOnScopeChains(Context.getObjCSelDecl(), TUScope);
152 // If 'id' does not yet refer to any declarations, make it refer to the
154 DeclarationName Id = &Context.Idents.get("id");
155 if (IdResolver.begin(Id) == IdResolver.end())
156 PushOnScopeChains(Context.getObjCIdDecl(), TUScope);
158 // Create the built-in typedef for 'Class'.
159 DeclarationName Class = &Context.Idents.get("Class");
160 if (IdResolver.begin(Class) == IdResolver.end())
161 PushOnScopeChains(Context.getObjCClassDecl(), TUScope);
163 // Create the built-in forward declaratino for 'Protocol'.
164 DeclarationName Protocol = &Context.Idents.get("Protocol");
165 if (IdResolver.begin(Protocol) == IdResolver.end())
166 PushOnScopeChains(Context.getObjCProtocolDecl(), TUScope);
169 DeclarationName BuiltinVaList = &Context.Idents.get("__builtin_va_list");
170 if (IdResolver.begin(BuiltinVaList) == IdResolver.end())
171 PushOnScopeChains(Context.getBuiltinVaListDecl(), TUScope);
175 if (PackContext) FreePackedContext();
176 if (VisContext) FreeVisContext();
177 delete TheTargetAttributesSema;
178 MSStructPragmaOn = false;
179 // Kill all the active scopes.
180 for (unsigned I = 1, E = FunctionScopes.size(); I != E; ++I)
181 delete FunctionScopes[I];
182 if (FunctionScopes.size() == 1)
183 delete FunctionScopes[0];
185 // Tell the SemaConsumer to forget about us; we're going out of scope.
186 if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer))
189 // Detach from the external Sema source.
190 if (ExternalSemaSource *ExternalSema
191 = dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource()))
192 ExternalSema->ForgetSema();
194 // If Sema's ExternalSource is the multiplexer - we own it.
195 if (isMultiplexExternalSource)
196 delete ExternalSource;
199 /// makeUnavailableInSystemHeader - There is an error in the current
200 /// context. If we're still in a system header, and we can plausibly
201 /// make the relevant declaration unavailable instead of erroring, do
202 /// so and return true.
203 bool Sema::makeUnavailableInSystemHeader(SourceLocation loc,
205 // If we're not in a function, it's an error.
206 FunctionDecl *fn = dyn_cast<FunctionDecl>(CurContext);
207 if (!fn) return false;
209 // If we're in template instantiation, it's an error.
210 if (!ActiveTemplateInstantiations.empty())
213 // If that function's not in a system header, it's an error.
214 if (!Context.getSourceManager().isInSystemHeader(loc))
217 // If the function is already unavailable, it's not an error.
218 if (fn->hasAttr<UnavailableAttr>()) return true;
220 fn->addAttr(new (Context) UnavailableAttr(loc, Context, msg));
224 ASTMutationListener *Sema::getASTMutationListener() const {
225 return getASTConsumer().GetASTMutationListener();
228 ///\brief Registers an external source. If an external source already exists,
229 /// creates a multiplex external source and appends to it.
231 ///\param[in] E - A non-null external sema source.
233 void Sema::addExternalSource(ExternalSemaSource *E) {
234 assert(E && "Cannot use with NULL ptr");
236 if (!ExternalSource) {
241 if (isMultiplexExternalSource)
242 static_cast<MultiplexExternalSemaSource*>(ExternalSource)->addSource(*E);
244 ExternalSource = new MultiplexExternalSemaSource(*ExternalSource, *E);
245 isMultiplexExternalSource = true;
249 /// \brief Print out statistics about the semantic analysis.
250 void Sema::PrintStats() const {
251 llvm::errs() << "\n*** Semantic Analysis Stats:\n";
252 llvm::errs() << NumSFINAEErrors << " SFINAE diagnostics trapped.\n";
254 BumpAlloc.PrintStats();
255 AnalysisWarnings.PrintStats();
258 /// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast.
259 /// If there is already an implicit cast, merge into the existing one.
260 /// The result is of the given category.
261 ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty,
262 CastKind Kind, ExprValueKind VK,
263 const CXXCastPath *BasePath,
264 CheckedConversionKind CCK) {
266 if (VK == VK_RValue && !E->isRValue()) {
269 assert(0 && "can't implicitly cast lvalue to rvalue with this cast kind");
270 case CK_LValueToRValue:
271 case CK_ArrayToPointerDecay:
272 case CK_FunctionToPointerDecay:
277 assert((VK == VK_RValue || !E->isRValue()) && "can't cast rvalue to lvalue");
280 QualType ExprTy = Context.getCanonicalType(E->getType());
281 QualType TypeTy = Context.getCanonicalType(Ty);
283 if (ExprTy == TypeTy)
286 if (getLangOpts().ObjCAutoRefCount)
287 CheckObjCARCConversion(SourceRange(), Ty, E, CCK);
289 // If this is a derived-to-base cast to a through a virtual base, we
291 if (Kind == CK_DerivedToBase &&
292 BasePathInvolvesVirtualBase(*BasePath)) {
293 QualType T = E->getType();
294 if (const PointerType *Pointer = T->getAs<PointerType>())
295 T = Pointer->getPointeeType();
296 if (const RecordType *RecordTy = T->getAs<RecordType>())
297 MarkVTableUsed(E->getLocStart(),
298 cast<CXXRecordDecl>(RecordTy->getDecl()));
301 if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(E)) {
302 if (ImpCast->getCastKind() == Kind && (!BasePath || BasePath->empty())) {
303 ImpCast->setType(Ty);
304 ImpCast->setValueKind(VK);
309 return Owned(ImplicitCastExpr::Create(Context, Ty, Kind, E, BasePath, VK));
312 /// ScalarTypeToBooleanCastKind - Returns the cast kind corresponding
313 /// to the conversion from scalar type ScalarTy to the Boolean type.
314 CastKind Sema::ScalarTypeToBooleanCastKind(QualType ScalarTy) {
315 switch (ScalarTy->getScalarTypeKind()) {
316 case Type::STK_Bool: return CK_NoOp;
317 case Type::STK_CPointer: return CK_PointerToBoolean;
318 case Type::STK_BlockPointer: return CK_PointerToBoolean;
319 case Type::STK_ObjCObjectPointer: return CK_PointerToBoolean;
320 case Type::STK_MemberPointer: return CK_MemberPointerToBoolean;
321 case Type::STK_Integral: return CK_IntegralToBoolean;
322 case Type::STK_Floating: return CK_FloatingToBoolean;
323 case Type::STK_IntegralComplex: return CK_IntegralComplexToBoolean;
324 case Type::STK_FloatingComplex: return CK_FloatingComplexToBoolean;
329 /// \brief Used to prune the decls of Sema's UnusedFileScopedDecls vector.
330 static bool ShouldRemoveFromUnused(Sema *SemaRef, const DeclaratorDecl *D) {
334 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
335 // UnusedFileScopedDecls stores the first declaration.
336 // The declaration may have become definition so check again.
337 const FunctionDecl *DeclToCheck;
338 if (FD->hasBody(DeclToCheck))
339 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
341 // Later redecls may add new information resulting in not having to warn,
343 DeclToCheck = FD->getMostRecentDecl();
344 if (DeclToCheck != FD)
345 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
348 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
349 // UnusedFileScopedDecls stores the first declaration.
350 // The declaration may have become definition so check again.
351 const VarDecl *DeclToCheck = VD->getDefinition();
353 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
355 // Later redecls may add new information resulting in not having to warn,
357 DeclToCheck = VD->getMostRecentDecl();
358 if (DeclToCheck != VD)
359 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
366 struct UndefinedInternal {
368 FullSourceLoc useLoc;
370 UndefinedInternal(NamedDecl *decl, FullSourceLoc useLoc)
371 : decl(decl), useLoc(useLoc) {}
374 bool operator<(const UndefinedInternal &l, const UndefinedInternal &r) {
375 return l.useLoc.isBeforeInTranslationUnitThan(r.useLoc);
379 /// checkUndefinedInternals - Check for undefined objects with internal linkage.
380 static void checkUndefinedInternals(Sema &S) {
381 if (S.UndefinedInternals.empty()) return;
383 // Collect all the still-undefined entities with internal linkage.
384 SmallVector<UndefinedInternal, 16> undefined;
385 for (llvm::DenseMap<NamedDecl*,SourceLocation>::iterator
386 i = S.UndefinedInternals.begin(), e = S.UndefinedInternals.end();
388 NamedDecl *decl = i->first;
390 // Ignore attributes that have become invalid.
391 if (decl->isInvalidDecl()) continue;
393 // __attribute__((weakref)) is basically a definition.
394 if (decl->hasAttr<WeakRefAttr>()) continue;
396 if (FunctionDecl *fn = dyn_cast<FunctionDecl>(decl)) {
397 if (fn->isPure() || fn->hasBody())
400 if (cast<VarDecl>(decl)->hasDefinition() != VarDecl::DeclarationOnly)
404 // We build a FullSourceLoc so that we can sort with array_pod_sort.
405 FullSourceLoc loc(i->second, S.Context.getSourceManager());
406 undefined.push_back(UndefinedInternal(decl, loc));
409 if (undefined.empty()) return;
411 // Sort (in order of use site) so that we're not (as) dependent on
412 // the iteration order through an llvm::DenseMap.
413 llvm::array_pod_sort(undefined.begin(), undefined.end());
415 for (SmallVectorImpl<UndefinedInternal>::iterator
416 i = undefined.begin(), e = undefined.end(); i != e; ++i) {
417 NamedDecl *decl = i->decl;
418 S.Diag(decl->getLocation(), diag::warn_undefined_internal)
419 << isa<VarDecl>(decl) << decl;
420 S.Diag(i->useLoc, diag::note_used_here);
424 void Sema::LoadExternalWeakUndeclaredIdentifiers() {
428 SmallVector<std::pair<IdentifierInfo *, WeakInfo>, 4> WeakIDs;
429 ExternalSource->ReadWeakUndeclaredIdentifiers(WeakIDs);
430 for (unsigned I = 0, N = WeakIDs.size(); I != N; ++I) {
431 llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator Pos
432 = WeakUndeclaredIdentifiers.find(WeakIDs[I].first);
433 if (Pos != WeakUndeclaredIdentifiers.end())
436 WeakUndeclaredIdentifiers.insert(WeakIDs[I]);
441 typedef llvm::DenseMap<const CXXRecordDecl*, bool> RecordCompleteMap;
443 /// \brief Returns true, if all methods and nested classes of the given
444 /// CXXRecordDecl are defined in this translation unit.
446 /// Should only be called from ActOnEndOfTranslationUnit so that all
447 /// definitions are actually read.
448 static bool MethodsAndNestedClassesComplete(const CXXRecordDecl *RD,
449 RecordCompleteMap &MNCComplete) {
450 RecordCompleteMap::iterator Cache = MNCComplete.find(RD);
451 if (Cache != MNCComplete.end())
452 return Cache->second;
453 if (!RD->isCompleteDefinition())
455 bool Complete = true;
456 for (DeclContext::decl_iterator I = RD->decls_begin(),
458 I != E && Complete; ++I) {
459 if (const CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(*I))
460 Complete = M->isDefined() || (M->isPure() && !isa<CXXDestructorDecl>(M));
461 else if (const FunctionTemplateDecl *F = dyn_cast<FunctionTemplateDecl>(*I))
462 Complete = F->getTemplatedDecl()->isDefined();
463 else if (const CXXRecordDecl *R = dyn_cast<CXXRecordDecl>(*I)) {
464 if (R->isInjectedClassName())
466 if (R->hasDefinition())
467 Complete = MethodsAndNestedClassesComplete(R->getDefinition(),
473 MNCComplete[RD] = Complete;
477 /// \brief Returns true, if the given CXXRecordDecl is fully defined in this
478 /// translation unit, i.e. all methods are defined or pure virtual and all
479 /// friends, friend functions and nested classes are fully defined in this
480 /// translation unit.
482 /// Should only be called from ActOnEndOfTranslationUnit so that all
483 /// definitions are actually read.
484 static bool IsRecordFullyDefined(const CXXRecordDecl *RD,
485 RecordCompleteMap &RecordsComplete,
486 RecordCompleteMap &MNCComplete) {
487 RecordCompleteMap::iterator Cache = RecordsComplete.find(RD);
488 if (Cache != RecordsComplete.end())
489 return Cache->second;
490 bool Complete = MethodsAndNestedClassesComplete(RD, MNCComplete);
491 for (CXXRecordDecl::friend_iterator I = RD->friend_begin(),
492 E = RD->friend_end();
493 I != E && Complete; ++I) {
494 // Check if friend classes and methods are complete.
495 if (TypeSourceInfo *TSI = (*I)->getFriendType()) {
496 // Friend classes are available as the TypeSourceInfo of the FriendDecl.
497 if (CXXRecordDecl *FriendD = TSI->getType()->getAsCXXRecordDecl())
498 Complete = MethodsAndNestedClassesComplete(FriendD, MNCComplete);
502 // Friend functions are available through the NamedDecl of FriendDecl.
503 if (const FunctionDecl *FD =
504 dyn_cast<FunctionDecl>((*I)->getFriendDecl()))
505 Complete = FD->isDefined();
507 // This is a template friend, give up.
511 RecordsComplete[RD] = Complete;
515 /// ActOnEndOfTranslationUnit - This is called at the very end of the
516 /// translation unit when EOF is reached and all but the top-level scope is
518 void Sema::ActOnEndOfTranslationUnit() {
519 assert(DelayedDiagnostics.getCurrentPool() == NULL
520 && "reached end of translation unit with a pool attached?");
522 // If code completion is enabled, don't perform any end-of-translation-unit
524 if (PP.isCodeCompletionEnabled())
527 // Only complete translation units define vtables and perform implicit
529 if (TUKind == TU_Complete) {
530 DiagnoseUseOfUnimplementedSelectors();
532 // If any dynamic classes have their key function defined within
533 // this translation unit, then those vtables are considered "used" and must
535 for (DynamicClassesType::iterator I = DynamicClasses.begin(ExternalSource),
536 E = DynamicClasses.end();
538 assert(!(*I)->isDependentType() &&
539 "Should not see dependent types here!");
540 if (const CXXMethodDecl *KeyFunction = Context.getKeyFunction(*I)) {
541 const FunctionDecl *Definition = 0;
542 if (KeyFunction->hasBody(Definition))
543 MarkVTableUsed(Definition->getLocation(), *I, true);
547 // If DefinedUsedVTables ends up marking any virtual member functions it
548 // might lead to more pending template instantiations, which we then need
552 // C++: Perform implicit template instantiations.
554 // FIXME: When we perform these implicit instantiations, we do not
555 // carefully keep track of the point of instantiation (C++ [temp.point]).
556 // This means that name lookup that occurs within the template
557 // instantiation will always happen at the end of the translation unit,
558 // so it will find some names that should not be found. Although this is
559 // common behavior for C++ compilers, it is technically wrong. In the
560 // future, we either need to be able to filter the results of name lookup
561 // or we need to perform template instantiations earlier.
562 PerformPendingInstantiations();
565 // Remove file scoped decls that turned out to be used.
566 UnusedFileScopedDecls.erase(std::remove_if(UnusedFileScopedDecls.begin(0,
568 UnusedFileScopedDecls.end(),
569 std::bind1st(std::ptr_fun(ShouldRemoveFromUnused),
571 UnusedFileScopedDecls.end());
573 if (TUKind == TU_Prefix) {
574 // Translation unit prefixes don't need any of the checking below.
579 // Check for #pragma weak identifiers that were never declared
580 // FIXME: This will cause diagnostics to be emitted in a non-determinstic
581 // order! Iterating over a densemap like this is bad.
582 LoadExternalWeakUndeclaredIdentifiers();
583 for (llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator
584 I = WeakUndeclaredIdentifiers.begin(),
585 E = WeakUndeclaredIdentifiers.end(); I != E; ++I) {
586 if (I->second.getUsed()) continue;
588 Diag(I->second.getLocation(), diag::warn_weak_identifier_undeclared)
592 if (TUKind == TU_Module) {
593 // If we are building a module, resolve all of the exported declarations
595 if (Module *CurrentModule = PP.getCurrentModule()) {
596 ModuleMap &ModMap = PP.getHeaderSearchInfo().getModuleMap();
598 llvm::SmallVector<Module *, 2> Stack;
599 Stack.push_back(CurrentModule);
600 while (!Stack.empty()) {
601 Module *Mod = Stack.back();
604 // Resolve the exported declarations.
605 // FIXME: Actually complain, once we figure out how to teach the
606 // diagnostic client to deal with complains in the module map at this
608 ModMap.resolveExports(Mod, /*Complain=*/false);
610 // Queue the submodules, so their exports will also be resolved.
611 for (Module::submodule_iterator Sub = Mod->submodule_begin(),
612 SubEnd = Mod->submodule_end();
613 Sub != SubEnd; ++Sub) {
614 Stack.push_back(*Sub);
619 // Modules don't need any of the checking below.
625 // A declaration of an identifier for an object that has file
626 // scope without an initializer, and without a storage-class
627 // specifier or with the storage-class specifier static,
628 // constitutes a tentative definition. If a translation unit
629 // contains one or more tentative definitions for an identifier,
630 // and the translation unit contains no external definition for
631 // that identifier, then the behavior is exactly as if the
632 // translation unit contains a file scope declaration of that
633 // identifier, with the composite type as of the end of the
634 // translation unit, with an initializer equal to 0.
635 llvm::SmallSet<VarDecl *, 32> Seen;
636 for (TentativeDefinitionsType::iterator
637 T = TentativeDefinitions.begin(ExternalSource),
638 TEnd = TentativeDefinitions.end();
641 VarDecl *VD = (*T)->getActingDefinition();
643 // If the tentative definition was completed, getActingDefinition() returns
644 // null. If we've already seen this variable before, insert()'s second
645 // return value is false.
646 if (VD == 0 || VD->isInvalidDecl() || !Seen.insert(VD))
649 if (const IncompleteArrayType *ArrayT
650 = Context.getAsIncompleteArrayType(VD->getType())) {
651 if (RequireCompleteType(VD->getLocation(),
652 ArrayT->getElementType(),
653 diag::err_tentative_def_incomplete_type_arr)) {
654 VD->setInvalidDecl();
658 // Set the length of the array to 1 (C99 6.9.2p5).
659 Diag(VD->getLocation(), diag::warn_tentative_incomplete_array);
660 llvm::APInt One(Context.getTypeSize(Context.getSizeType()), true);
661 QualType T = Context.getConstantArrayType(ArrayT->getElementType(),
662 One, ArrayType::Normal, 0);
664 } else if (RequireCompleteType(VD->getLocation(), VD->getType(),
665 diag::err_tentative_def_incomplete_type))
666 VD->setInvalidDecl();
668 CheckCompleteVariableDeclaration(VD);
670 // Notify the consumer that we've completed a tentative definition.
671 if (!VD->isInvalidDecl())
672 Consumer.CompleteTentativeDefinition(VD);
676 if (LangOpts.CPlusPlus0x &&
677 Diags.getDiagnosticLevel(diag::warn_delegating_ctor_cycle,
679 != DiagnosticsEngine::Ignored)
680 CheckDelegatingCtorCycles();
682 // If there were errors, disable 'unused' warnings since they will mostly be
684 if (!Diags.hasErrorOccurred()) {
685 // Output warning for unused file scoped decls.
686 for (UnusedFileScopedDeclsType::iterator
687 I = UnusedFileScopedDecls.begin(ExternalSource),
688 E = UnusedFileScopedDecls.end(); I != E; ++I) {
689 if (ShouldRemoveFromUnused(this, *I))
692 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
693 const FunctionDecl *DiagD;
694 if (!FD->hasBody(DiagD))
696 if (DiagD->isDeleted())
697 continue; // Deleted functions are supposed to be unused.
698 if (DiagD->isReferenced()) {
699 if (isa<CXXMethodDecl>(DiagD))
700 Diag(DiagD->getLocation(), diag::warn_unneeded_member_function)
701 << DiagD->getDeclName();
703 if (FD->getStorageClassAsWritten() == SC_Static &&
704 !FD->isInlineSpecified() &&
705 !SourceMgr.isFromMainFile(
706 SourceMgr.getExpansionLoc(FD->getLocation())))
707 Diag(DiagD->getLocation(), diag::warn_unneeded_static_internal_decl)
708 << DiagD->getDeclName();
710 Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl)
711 << /*function*/0 << DiagD->getDeclName();
714 Diag(DiagD->getLocation(),
715 isa<CXXMethodDecl>(DiagD) ? diag::warn_unused_member_function
716 : diag::warn_unused_function)
717 << DiagD->getDeclName();
720 const VarDecl *DiagD = cast<VarDecl>(*I)->getDefinition();
722 DiagD = cast<VarDecl>(*I);
723 if (DiagD->isReferenced()) {
724 Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl)
725 << /*variable*/1 << DiagD->getDeclName();
727 Diag(DiagD->getLocation(), diag::warn_unused_variable)
728 << DiagD->getDeclName();
733 checkUndefinedInternals(*this);
736 if (Diags.getDiagnosticLevel(diag::warn_unused_private_field,
738 != DiagnosticsEngine::Ignored) {
739 RecordCompleteMap RecordsComplete;
740 RecordCompleteMap MNCComplete;
741 for (NamedDeclSetType::iterator I = UnusedPrivateFields.begin(),
742 E = UnusedPrivateFields.end(); I != E; ++I) {
743 const NamedDecl *D = *I;
744 const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext());
745 if (RD && !RD->isUnion() &&
746 IsRecordFullyDefined(RD, RecordsComplete, MNCComplete)) {
747 Diag(D->getLocation(), diag::warn_unused_private_field)
753 // Check we've noticed that we're no longer parsing the initializer for every
754 // variable. If we miss cases, then at best we have a performance issue and
755 // at worst a rejects-valid bug.
756 assert(ParsingInitForAutoVars.empty() &&
757 "Didn't unmark var as having its initializer parsed");
763 //===----------------------------------------------------------------------===//
765 //===----------------------------------------------------------------------===//
767 DeclContext *Sema::getFunctionLevelDeclContext() {
768 DeclContext *DC = CurContext;
771 if (isa<BlockDecl>(DC) || isa<EnumDecl>(DC)) {
772 DC = DC->getParent();
773 } else if (isa<CXXMethodDecl>(DC) &&
774 cast<CXXMethodDecl>(DC)->getOverloadedOperator() == OO_Call &&
775 cast<CXXRecordDecl>(DC->getParent())->isLambda()) {
776 DC = DC->getParent()->getParent();
784 /// getCurFunctionDecl - If inside of a function body, this returns a pointer
785 /// to the function decl for the function being parsed. If we're currently
786 /// in a 'block', this returns the containing context.
787 FunctionDecl *Sema::getCurFunctionDecl() {
788 DeclContext *DC = getFunctionLevelDeclContext();
789 return dyn_cast<FunctionDecl>(DC);
792 ObjCMethodDecl *Sema::getCurMethodDecl() {
793 DeclContext *DC = getFunctionLevelDeclContext();
794 return dyn_cast<ObjCMethodDecl>(DC);
797 NamedDecl *Sema::getCurFunctionOrMethodDecl() {
798 DeclContext *DC = getFunctionLevelDeclContext();
799 if (isa<ObjCMethodDecl>(DC) || isa<FunctionDecl>(DC))
800 return cast<NamedDecl>(DC);
804 void Sema::EmitCurrentDiagnostic(unsigned DiagID) {
805 // FIXME: It doesn't make sense to me that DiagID is an incoming argument here
806 // and yet we also use the current diag ID on the DiagnosticsEngine. This has
807 // been made more painfully obvious by the refactor that introduced this
808 // function, but it is possible that the incoming argument can be
809 // eliminnated. If it truly cannot be (for example, there is some reentrancy
810 // issue I am not seeing yet), then there should at least be a clarifying
811 // comment somewhere.
812 if (llvm::Optional<TemplateDeductionInfo*> Info = isSFINAEContext()) {
813 switch (DiagnosticIDs::getDiagnosticSFINAEResponse(
814 Diags.getCurrentDiagID())) {
815 case DiagnosticIDs::SFINAE_Report:
816 // We'll report the diagnostic below.
819 case DiagnosticIDs::SFINAE_SubstitutionFailure:
820 // Count this failure so that we know that template argument deduction
824 // Make a copy of this suppressed diagnostic and store it with the
825 // template-deduction information.
826 if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
827 Diagnostic DiagInfo(&Diags);
828 (*Info)->addSFINAEDiagnostic(DiagInfo.getLocation(),
829 PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
832 Diags.setLastDiagnosticIgnored();
836 case DiagnosticIDs::SFINAE_AccessControl: {
837 // Per C++ Core Issue 1170, access control is part of SFINAE.
838 // Additionally, the AccessCheckingSFINAE flag can be used to temporarily
839 // make access control a part of SFINAE for the purposes of checking
841 if (!AccessCheckingSFINAE && !getLangOpts().CPlusPlus0x)
844 SourceLocation Loc = Diags.getCurrentDiagLoc();
846 // Suppress this diagnostic.
849 // Make a copy of this suppressed diagnostic and store it with the
850 // template-deduction information.
851 if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
852 Diagnostic DiagInfo(&Diags);
853 (*Info)->addSFINAEDiagnostic(DiagInfo.getLocation(),
854 PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
857 Diags.setLastDiagnosticIgnored();
860 // Now the diagnostic state is clear, produce a C++98 compatibility
862 Diag(Loc, diag::warn_cxx98_compat_sfinae_access_control);
864 // The last diagnostic which Sema produced was ignored. Suppress any
865 // notes attached to it.
866 Diags.setLastDiagnosticIgnored();
870 case DiagnosticIDs::SFINAE_Suppress:
871 // Make a copy of this suppressed diagnostic and store it with the
872 // template-deduction information;
874 Diagnostic DiagInfo(&Diags);
875 (*Info)->addSuppressedDiagnostic(DiagInfo.getLocation(),
876 PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
879 // Suppress this diagnostic.
880 Diags.setLastDiagnosticIgnored();
886 // Set up the context's printing policy based on our current state.
887 Context.setPrintingPolicy(getPrintingPolicy());
889 // Emit the diagnostic.
890 if (!Diags.EmitCurrentDiagnostic())
893 // If this is not a note, and we're in a template instantiation
894 // that is different from the last template instantiation where
895 // we emitted an error, print a template instantiation
897 if (!DiagnosticIDs::isBuiltinNote(DiagID) &&
898 !ActiveTemplateInstantiations.empty() &&
899 ActiveTemplateInstantiations.back()
900 != LastTemplateInstantiationErrorContext) {
901 PrintInstantiationStack();
902 LastTemplateInstantiationErrorContext = ActiveTemplateInstantiations.back();
906 Sema::SemaDiagnosticBuilder
907 Sema::Diag(SourceLocation Loc, const PartialDiagnostic& PD) {
908 SemaDiagnosticBuilder Builder(Diag(Loc, PD.getDiagID()));
914 /// \brief Looks through the macro-expansion chain for the given
915 /// location, looking for a macro expansion with the given name.
916 /// If one is found, returns true and sets the location to that
918 bool Sema::findMacroSpelling(SourceLocation &locref, StringRef name) {
919 SourceLocation loc = locref;
920 if (!loc.isMacroID()) return false;
922 // There's no good way right now to look at the intermediate
923 // expansions, so just jump to the expansion location.
924 loc = getSourceManager().getExpansionLoc(loc);
926 // If that's written with the name, stop here.
927 SmallVector<char, 16> buffer;
928 if (getPreprocessor().getSpelling(loc, buffer) == name) {
935 /// \brief Determines the active Scope associated with the given declaration
938 /// This routine maps a declaration context to the active Scope object that
939 /// represents that declaration context in the parser. It is typically used
940 /// from "scope-less" code (e.g., template instantiation, lazy creation of
941 /// declarations) that injects a name for name-lookup purposes and, therefore,
942 /// must update the Scope.
944 /// \returns The scope corresponding to the given declaraion context, or NULL
945 /// if no such scope is open.
946 Scope *Sema::getScopeForContext(DeclContext *Ctx) {
951 Ctx = Ctx->getPrimaryContext();
952 for (Scope *S = getCurScope(); S; S = S->getParent()) {
953 // Ignore scopes that cannot have declarations. This is important for
954 // out-of-line definitions of static class members.
955 if (S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope))
956 if (DeclContext *Entity = static_cast<DeclContext *> (S->getEntity()))
957 if (Ctx == Entity->getPrimaryContext())
964 /// \brief Enter a new function scope
965 void Sema::PushFunctionScope() {
966 if (FunctionScopes.size() == 1) {
967 // Use the "top" function scope rather than having to allocate
968 // memory for a new scope.
969 FunctionScopes.back()->Clear();
970 FunctionScopes.push_back(FunctionScopes.back());
974 FunctionScopes.push_back(new FunctionScopeInfo(getDiagnostics()));
977 void Sema::PushBlockScope(Scope *BlockScope, BlockDecl *Block) {
978 FunctionScopes.push_back(new BlockScopeInfo(getDiagnostics(),
982 void Sema::PushLambdaScope(CXXRecordDecl *Lambda,
983 CXXMethodDecl *CallOperator) {
984 FunctionScopes.push_back(new LambdaScopeInfo(getDiagnostics(), Lambda,
988 void Sema::PopFunctionScopeInfo(const AnalysisBasedWarnings::Policy *WP,
989 const Decl *D, const BlockExpr *blkExpr) {
990 FunctionScopeInfo *Scope = FunctionScopes.pop_back_val();
991 assert(!FunctionScopes.empty() && "mismatched push/pop!");
993 // Issue any analysis-based warnings.
995 AnalysisWarnings.IssueWarnings(*WP, Scope, D, blkExpr);
997 for (SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator
998 i = Scope->PossiblyUnreachableDiags.begin(),
999 e = Scope->PossiblyUnreachableDiags.end();
1001 const sema::PossiblyUnreachableDiag &D = *i;
1006 if (FunctionScopes.back() != Scope) {
1011 void Sema::PushCompoundScope() {
1012 getCurFunction()->CompoundScopes.push_back(CompoundScopeInfo());
1015 void Sema::PopCompoundScope() {
1016 FunctionScopeInfo *CurFunction = getCurFunction();
1017 assert(!CurFunction->CompoundScopes.empty() && "mismatched push/pop");
1019 CurFunction->CompoundScopes.pop_back();
1022 /// \brief Determine whether any errors occurred within this function/method/
1024 bool Sema::hasAnyUnrecoverableErrorsInThisFunction() const {
1025 return getCurFunction()->ErrorTrap.hasUnrecoverableErrorOccurred();
1028 BlockScopeInfo *Sema::getCurBlock() {
1029 if (FunctionScopes.empty())
1032 return dyn_cast<BlockScopeInfo>(FunctionScopes.back());
1035 LambdaScopeInfo *Sema::getCurLambda() {
1036 if (FunctionScopes.empty())
1039 return dyn_cast<LambdaScopeInfo>(FunctionScopes.back());
1042 void Sema::ActOnComment(SourceRange Comment) {
1043 if (!LangOpts.RetainCommentsFromSystemHeaders &&
1044 SourceMgr.isInSystemHeader(Comment.getBegin()))
1046 RawComment RC(SourceMgr, Comment);
1047 if (RC.isAlmostTrailingComment()) {
1048 SourceRange MagicMarkerRange(Comment.getBegin(),
1049 Comment.getBegin().getLocWithOffset(3));
1050 StringRef MagicMarkerText;
1051 switch (RC.getKind()) {
1052 case RawComment::RCK_OrdinaryBCPL:
1053 MagicMarkerText = "///<";
1055 case RawComment::RCK_OrdinaryC:
1056 MagicMarkerText = "/**<";
1059 llvm_unreachable("if this is an almost Doxygen comment, "
1060 "it should be ordinary");
1062 Diag(Comment.getBegin(), diag::warn_not_a_doxygen_trailing_member_comment) <<
1063 FixItHint::CreateReplacement(MagicMarkerRange, MagicMarkerText);
1065 Context.addComment(RC);
1068 // Pin this vtable to this file.
1069 ExternalSemaSource::~ExternalSemaSource() {}
1071 void ExternalSemaSource::ReadMethodPool(Selector Sel) { }
1073 void ExternalSemaSource::ReadKnownNamespaces(
1074 SmallVectorImpl<NamespaceDecl *> &Namespaces) {
1077 void PrettyDeclStackTraceEntry::print(raw_ostream &OS) const {
1078 SourceLocation Loc = this->Loc;
1079 if (!Loc.isValid() && TheDecl) Loc = TheDecl->getLocation();
1080 if (Loc.isValid()) {
1081 Loc.print(OS, S.getSourceManager());
1086 if (TheDecl && isa<NamedDecl>(TheDecl)) {
1087 std::string Name = cast<NamedDecl>(TheDecl)->getNameAsString();
1089 OS << " '" << Name << '\'';
1095 /// \brief Figure out if an expression could be turned into a call.
1097 /// Use this when trying to recover from an error where the programmer may have
1098 /// written just the name of a function instead of actually calling it.
1100 /// \param E - The expression to examine.
1101 /// \param ZeroArgCallReturnTy - If the expression can be turned into a call
1102 /// with no arguments, this parameter is set to the type returned by such a
1103 /// call; otherwise, it is set to an empty QualType.
1104 /// \param OverloadSet - If the expression is an overloaded function
1105 /// name, this parameter is populated with the decls of the various overloads.
1106 bool Sema::isExprCallable(const Expr &E, QualType &ZeroArgCallReturnTy,
1107 UnresolvedSetImpl &OverloadSet) {
1108 ZeroArgCallReturnTy = QualType();
1109 OverloadSet.clear();
1111 if (E.getType() == Context.OverloadTy) {
1112 OverloadExpr::FindResult FR = OverloadExpr::find(const_cast<Expr*>(&E));
1113 const OverloadExpr *Overloads = FR.Expression;
1115 for (OverloadExpr::decls_iterator it = Overloads->decls_begin(),
1116 DeclsEnd = Overloads->decls_end(); it != DeclsEnd; ++it) {
1117 OverloadSet.addDecl(*it);
1119 // Check whether the function is a non-template which takes no
1121 if (const FunctionDecl *OverloadDecl
1122 = dyn_cast<FunctionDecl>((*it)->getUnderlyingDecl())) {
1123 if (OverloadDecl->getMinRequiredArguments() == 0)
1124 ZeroArgCallReturnTy = OverloadDecl->getResultType();
1128 // Ignore overloads that are pointer-to-member constants.
1129 if (FR.HasFormOfMemberPointer)
1135 if (const DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E.IgnoreParens())) {
1136 if (const FunctionDecl *Fun = dyn_cast<FunctionDecl>(DeclRef->getDecl())) {
1137 if (Fun->getMinRequiredArguments() == 0)
1138 ZeroArgCallReturnTy = Fun->getResultType();
1143 // We don't have an expression that's convenient to get a FunctionDecl from,
1144 // but we can at least check if the type is "function of 0 arguments".
1145 QualType ExprTy = E.getType();
1146 const FunctionType *FunTy = NULL;
1147 QualType PointeeTy = ExprTy->getPointeeType();
1148 if (!PointeeTy.isNull())
1149 FunTy = PointeeTy->getAs<FunctionType>();
1151 FunTy = ExprTy->getAs<FunctionType>();
1152 if (!FunTy && ExprTy == Context.BoundMemberTy) {
1153 // Look for the bound-member type. If it's still overloaded, give up,
1154 // although we probably should have fallen into the OverloadExpr case above
1155 // if we actually have an overloaded bound member.
1156 QualType BoundMemberTy = Expr::findBoundMemberType(&E);
1157 if (!BoundMemberTy.isNull())
1158 FunTy = BoundMemberTy->castAs<FunctionType>();
1161 if (const FunctionProtoType *FPT =
1162 dyn_cast_or_null<FunctionProtoType>(FunTy)) {
1163 if (FPT->getNumArgs() == 0)
1164 ZeroArgCallReturnTy = FunTy->getResultType();
1170 /// \brief Give notes for a set of overloads.
1172 /// A companion to isExprCallable. In cases when the name that the programmer
1173 /// wrote was an overloaded function, we may be able to make some guesses about
1174 /// plausible overloads based on their return types; such guesses can be handed
1175 /// off to this method to be emitted as notes.
1177 /// \param Overloads - The overloads to note.
1178 /// \param FinalNoteLoc - If we've suppressed printing some overloads due to
1179 /// -fshow-overloads=best, this is the location to attach to the note about too
1180 /// many candidates. Typically this will be the location of the original
1181 /// ill-formed expression.
1182 static void noteOverloads(Sema &S, const UnresolvedSetImpl &Overloads,
1183 const SourceLocation FinalNoteLoc) {
1184 int ShownOverloads = 0;
1185 int SuppressedOverloads = 0;
1186 for (UnresolvedSetImpl::iterator It = Overloads.begin(),
1187 DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
1188 // FIXME: Magic number for max shown overloads stolen from
1189 // OverloadCandidateSet::NoteCandidates.
1190 if (ShownOverloads >= 4 && S.Diags.getShowOverloads() == Ovl_Best) {
1191 ++SuppressedOverloads;
1195 NamedDecl *Fn = (*It)->getUnderlyingDecl();
1196 S.Diag(Fn->getLocation(), diag::note_possible_target_of_call);
1200 if (SuppressedOverloads)
1201 S.Diag(FinalNoteLoc, diag::note_ovl_too_many_candidates)
1202 << SuppressedOverloads;
1205 static void notePlausibleOverloads(Sema &S, SourceLocation Loc,
1206 const UnresolvedSetImpl &Overloads,
1207 bool (*IsPlausibleResult)(QualType)) {
1208 if (!IsPlausibleResult)
1209 return noteOverloads(S, Overloads, Loc);
1211 UnresolvedSet<2> PlausibleOverloads;
1212 for (OverloadExpr::decls_iterator It = Overloads.begin(),
1213 DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
1214 const FunctionDecl *OverloadDecl = cast<FunctionDecl>(*It);
1215 QualType OverloadResultTy = OverloadDecl->getResultType();
1216 if (IsPlausibleResult(OverloadResultTy))
1217 PlausibleOverloads.addDecl(It.getDecl());
1219 noteOverloads(S, PlausibleOverloads, Loc);
1222 /// Determine whether the given expression can be called by just
1223 /// putting parentheses after it. Notably, expressions with unary
1224 /// operators can't be because the unary operator will start parsing
1225 /// outside the call.
1226 static bool IsCallableWithAppend(Expr *E) {
1227 E = E->IgnoreImplicit();
1228 return (!isa<CStyleCastExpr>(E) &&
1229 !isa<UnaryOperator>(E) &&
1230 !isa<BinaryOperator>(E) &&
1231 !isa<CXXOperatorCallExpr>(E));
1234 bool Sema::tryToRecoverWithCall(ExprResult &E, const PartialDiagnostic &PD,
1236 bool (*IsPlausibleResult)(QualType)) {
1237 SourceLocation Loc = E.get()->getExprLoc();
1238 SourceRange Range = E.get()->getSourceRange();
1240 QualType ZeroArgCallTy;
1241 UnresolvedSet<4> Overloads;
1242 if (isExprCallable(*E.get(), ZeroArgCallTy, Overloads) &&
1243 !ZeroArgCallTy.isNull() &&
1244 (!IsPlausibleResult || IsPlausibleResult(ZeroArgCallTy))) {
1245 // At this point, we know E is potentially callable with 0
1246 // arguments and that it returns something of a reasonable type,
1247 // so we can emit a fixit and carry on pretending that E was
1248 // actually a CallExpr.
1249 SourceLocation ParenInsertionLoc =
1250 PP.getLocForEndOfToken(Range.getEnd());
1252 << /*zero-arg*/ 1 << Range
1253 << (IsCallableWithAppend(E.get())
1254 ? FixItHint::CreateInsertion(ParenInsertionLoc, "()")
1256 notePlausibleOverloads(*this, Loc, Overloads, IsPlausibleResult);
1258 // FIXME: Try this before emitting the fixit, and suppress diagnostics
1260 E = ActOnCallExpr(0, E.take(), ParenInsertionLoc,
1261 MultiExprArg(), ParenInsertionLoc.getLocWithOffset(1));
1265 if (!ForceComplain) return false;
1267 Diag(Loc, PD) << /*not zero-arg*/ 0 << Range;
1268 notePlausibleOverloads(*this, Loc, Overloads, IsPlausibleResult);