1 //===--- Sema.cpp - AST Builder and Semantic Analysis Implementation ------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file implements the actions class which performs semantic analysis and 11 // builds an AST out of a parse stream. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "clang/Sema/SemaInternal.h" 16 #include "TargetAttributesSema.h" 17 #include "clang/AST/ASTContext.h" 18 #include "clang/AST/ASTDiagnostic.h" 19 #include "clang/AST/DeclCXX.h" 20 #include "clang/AST/DeclFriend.h" 21 #include "clang/AST/DeclObjC.h" 22 #include "clang/AST/Expr.h" 23 #include "clang/AST/ExprCXX.h" 24 #include "clang/AST/StmtCXX.h" 25 #include "clang/Basic/FileManager.h" 26 #include "clang/Basic/PartialDiagnostic.h" 27 #include "clang/Basic/TargetInfo.h" 28 #include "clang/Lex/HeaderSearch.h" 29 #include "clang/Lex/Preprocessor.h" 30 #include "clang/Sema/CXXFieldCollector.h" 31 #include "clang/Sema/DelayedDiagnostic.h" 32 #include "clang/Sema/ExternalSemaSource.h" 33 #include "clang/Sema/MultiplexExternalSemaSource.h" 34 #include "clang/Sema/ObjCMethodList.h" 35 #include "clang/Sema/PrettyDeclStackTrace.h" 36 #include "clang/Sema/Scope.h" 37 #include "clang/Sema/ScopeInfo.h" 38 #include "clang/Sema/SemaConsumer.h" 39 #include "clang/Sema/TemplateDeduction.h" 40 #include "llvm/ADT/APFloat.h" 41 #include "llvm/ADT/DenseMap.h" 42 #include "llvm/ADT/SmallSet.h" 43 #include "llvm/Support/CrashRecoveryContext.h" 44 using namespace clang; 45 using namespace sema; 46 47 PrintingPolicy Sema::getPrintingPolicy(const ASTContext &Context, 48 const Preprocessor &PP) { 49 PrintingPolicy Policy = Context.getPrintingPolicy(); 50 Policy.Bool = Context.getLangOpts().Bool; 51 if (!Policy.Bool) { 52 if (const MacroInfo * 53 BoolMacro = PP.getMacroInfo(&Context.Idents.get("bool"))) { 54 Policy.Bool = BoolMacro->isObjectLike() && 55 BoolMacro->getNumTokens() == 1 && 56 BoolMacro->getReplacementToken(0).is(tok::kw__Bool); 57 } 58 } 59 60 return Policy; 61 } 62 63 void Sema::ActOnTranslationUnitScope(Scope *S) { 64 TUScope = S; 65 PushDeclContext(S, Context.getTranslationUnitDecl()); 66 67 VAListTagName = PP.getIdentifierInfo("__va_list_tag"); 68 } 69 70 Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer, 71 TranslationUnitKind TUKind, 72 CodeCompleteConsumer *CodeCompleter) 73 : TheTargetAttributesSema(0), ExternalSource(0), 74 isMultiplexExternalSource(false), FPFeatures(pp.getLangOpts()), 75 LangOpts(pp.getLangOpts()), PP(pp), Context(ctxt), Consumer(consumer), 76 Diags(PP.getDiagnostics()), SourceMgr(PP.getSourceManager()), 77 CollectStats(false), CodeCompleter(CodeCompleter), 78 CurContext(0), OriginalLexicalContext(0), 79 PackContext(0), MSStructPragmaOn(false), VisContext(0), 80 IsBuildingRecoveryCallExpr(false), 81 ExprNeedsCleanups(false), LateTemplateParser(0), OpaqueParser(0), 82 IdResolver(pp), StdInitializerList(0), CXXTypeInfoDecl(0), MSVCGuidDecl(0), 83 NSNumberDecl(0), 84 NSStringDecl(0), StringWithUTF8StringMethod(0), 85 NSArrayDecl(0), ArrayWithObjectsMethod(0), 86 NSDictionaryDecl(0), DictionaryWithObjectsMethod(0), 87 GlobalNewDeleteDeclared(false), 88 TUKind(TUKind), 89 NumSFINAEErrors(0), InFunctionDeclarator(0), 90 AccessCheckingSFINAE(false), InNonInstantiationSFINAEContext(false), 91 NonInstantiationEntries(0), ArgumentPackSubstitutionIndex(-1), 92 CurrentInstantiationScope(0), TyposCorrected(0), 93 AnalysisWarnings(*this), Ident_super(0) 94 { 95 TUScope = 0; 96 97 LoadedExternalKnownNamespaces = false; 98 for (unsigned I = 0; I != NSAPI::NumNSNumberLiteralMethods; ++I) 99 NSNumberLiteralMethods[I] = 0; 100 101 if (getLangOpts().ObjC1) 102 NSAPIObj.reset(new NSAPI(Context)); 103 104 if (getLangOpts().CPlusPlus) 105 FieldCollector.reset(new CXXFieldCollector()); 106 107 // Tell diagnostics how to render things from the AST library. 108 PP.getDiagnostics().SetArgToStringFn(&FormatASTNodeDiagnosticArgument, 109 &Context); 110 111 ExprEvalContexts.push_back( 112 ExpressionEvaluationContextRecord(PotentiallyEvaluated, 0, 113 false, 0, false)); 114 115 FunctionScopes.push_back(new FunctionScopeInfo(Diags)); 116 } 117 118 void Sema::Initialize() { 119 // Tell the AST consumer about this Sema object. 120 Consumer.Initialize(Context); 121 122 // FIXME: Isn't this redundant with the initialization above? 123 if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer)) 124 SC->InitializeSema(*this); 125 126 // Tell the external Sema source about this Sema object. 127 if (ExternalSemaSource *ExternalSema 128 = dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource())) 129 ExternalSema->InitializeSema(*this); 130 131 // Initialize predefined 128-bit integer types, if needed. 132 if (PP.getTargetInfo().hasInt128Type()) { 133 // If either of the 128-bit integer types are unavailable to name lookup, 134 // define them now. 135 DeclarationName Int128 = &Context.Idents.get("__int128_t"); 136 if (IdResolver.begin(Int128) == IdResolver.end()) 137 PushOnScopeChains(Context.getInt128Decl(), TUScope); 138 139 DeclarationName UInt128 = &Context.Idents.get("__uint128_t"); 140 if (IdResolver.begin(UInt128) == IdResolver.end()) 141 PushOnScopeChains(Context.getUInt128Decl(), TUScope); 142 } 143 144 145 // Initialize predefined Objective-C types: 146 if (PP.getLangOpts().ObjC1) { 147 // If 'SEL' does not yet refer to any declarations, make it refer to the 148 // predefined 'SEL'. 149 DeclarationName SEL = &Context.Idents.get("SEL"); 150 if (IdResolver.begin(SEL) == IdResolver.end()) 151 PushOnScopeChains(Context.getObjCSelDecl(), TUScope); 152 153 // If 'id' does not yet refer to any declarations, make it refer to the 154 // predefined 'id'. 155 DeclarationName Id = &Context.Idents.get("id"); 156 if (IdResolver.begin(Id) == IdResolver.end()) 157 PushOnScopeChains(Context.getObjCIdDecl(), TUScope); 158 159 // Create the built-in typedef for 'Class'. 160 DeclarationName Class = &Context.Idents.get("Class"); 161 if (IdResolver.begin(Class) == IdResolver.end()) 162 PushOnScopeChains(Context.getObjCClassDecl(), TUScope); 163 164 // Create the built-in forward declaratino for 'Protocol'. 165 DeclarationName Protocol = &Context.Idents.get("Protocol"); 166 if (IdResolver.begin(Protocol) == IdResolver.end()) 167 PushOnScopeChains(Context.getObjCProtocolDecl(), TUScope); 168 } 169 170 DeclarationName BuiltinVaList = &Context.Idents.get("__builtin_va_list"); 171 if (IdResolver.begin(BuiltinVaList) == IdResolver.end()) 172 PushOnScopeChains(Context.getBuiltinVaListDecl(), TUScope); 173 } 174 175 Sema::~Sema() { 176 if (PackContext) FreePackedContext(); 177 if (VisContext) FreeVisContext(); 178 delete TheTargetAttributesSema; 179 MSStructPragmaOn = false; 180 // Kill all the active scopes. 181 for (unsigned I = 1, E = FunctionScopes.size(); I != E; ++I) 182 delete FunctionScopes[I]; 183 if (FunctionScopes.size() == 1) 184 delete FunctionScopes[0]; 185 186 // Tell the SemaConsumer to forget about us; we're going out of scope. 187 if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer)) 188 SC->ForgetSema(); 189 190 // Detach from the external Sema source. 191 if (ExternalSemaSource *ExternalSema 192 = dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource())) 193 ExternalSema->ForgetSema(); 194 195 // If Sema's ExternalSource is the multiplexer - we own it. 196 if (isMultiplexExternalSource) 197 delete ExternalSource; 198 } 199 200 /// makeUnavailableInSystemHeader - There is an error in the current 201 /// context. If we're still in a system header, and we can plausibly 202 /// make the relevant declaration unavailable instead of erroring, do 203 /// so and return true. 204 bool Sema::makeUnavailableInSystemHeader(SourceLocation loc, 205 StringRef msg) { 206 // If we're not in a function, it's an error. 207 FunctionDecl *fn = dyn_cast<FunctionDecl>(CurContext); 208 if (!fn) return false; 209 210 // If we're in template instantiation, it's an error. 211 if (!ActiveTemplateInstantiations.empty()) 212 return false; 213 214 // If that function's not in a system header, it's an error. 215 if (!Context.getSourceManager().isInSystemHeader(loc)) 216 return false; 217 218 // If the function is already unavailable, it's not an error. 219 if (fn->hasAttr<UnavailableAttr>()) return true; 220 221 fn->addAttr(new (Context) UnavailableAttr(loc, Context, msg)); 222 return true; 223 } 224 225 ASTMutationListener *Sema::getASTMutationListener() const { 226 return getASTConsumer().GetASTMutationListener(); 227 } 228 229 ///\brief Registers an external source. If an external source already exists, 230 /// creates a multiplex external source and appends to it. 231 /// 232 ///\param[in] E - A non-null external sema source. 233 /// 234 void Sema::addExternalSource(ExternalSemaSource *E) { 235 assert(E && "Cannot use with NULL ptr"); 236 237 if (!ExternalSource) { 238 ExternalSource = E; 239 return; 240 } 241 242 if (isMultiplexExternalSource) 243 static_cast<MultiplexExternalSemaSource*>(ExternalSource)->addSource(*E); 244 else { 245 ExternalSource = new MultiplexExternalSemaSource(*ExternalSource, *E); 246 isMultiplexExternalSource = true; 247 } 248 } 249 250 /// \brief Print out statistics about the semantic analysis. 251 void Sema::PrintStats() const { 252 llvm::errs() << "\n*** Semantic Analysis Stats:\n"; 253 llvm::errs() << NumSFINAEErrors << " SFINAE diagnostics trapped.\n"; 254 255 BumpAlloc.PrintStats(); 256 AnalysisWarnings.PrintStats(); 257 } 258 259 /// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast. 260 /// If there is already an implicit cast, merge into the existing one. 261 /// The result is of the given category. 262 ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty, 263 CastKind Kind, ExprValueKind VK, 264 const CXXCastPath *BasePath, 265 CheckedConversionKind CCK) { 266 #ifndef NDEBUG 267 if (VK == VK_RValue && !E->isRValue()) { 268 switch (Kind) { 269 default: 270 assert(0 && "can't implicitly cast lvalue to rvalue with this cast kind"); 271 case CK_LValueToRValue: 272 case CK_ArrayToPointerDecay: 273 case CK_FunctionToPointerDecay: 274 case CK_ToVoid: 275 break; 276 } 277 } 278 assert((VK == VK_RValue || !E->isRValue()) && "can't cast rvalue to lvalue"); 279 #endif 280 281 QualType ExprTy = Context.getCanonicalType(E->getType()); 282 QualType TypeTy = Context.getCanonicalType(Ty); 283 284 if (ExprTy == TypeTy) 285 return Owned(E); 286 287 if (getLangOpts().ObjCAutoRefCount) 288 CheckObjCARCConversion(SourceRange(), Ty, E, CCK); 289 290 // If this is a derived-to-base cast to a through a virtual base, we 291 // need a vtable. 292 if (Kind == CK_DerivedToBase && 293 BasePathInvolvesVirtualBase(*BasePath)) { 294 QualType T = E->getType(); 295 if (const PointerType *Pointer = T->getAs<PointerType>()) 296 T = Pointer->getPointeeType(); 297 if (const RecordType *RecordTy = T->getAs<RecordType>()) 298 MarkVTableUsed(E->getLocStart(), 299 cast<CXXRecordDecl>(RecordTy->getDecl())); 300 } 301 302 if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(E)) { 303 if (ImpCast->getCastKind() == Kind && (!BasePath || BasePath->empty())) { 304 ImpCast->setType(Ty); 305 ImpCast->setValueKind(VK); 306 return Owned(E); 307 } 308 } 309 310 return Owned(ImplicitCastExpr::Create(Context, Ty, Kind, E, BasePath, VK)); 311 } 312 313 /// ScalarTypeToBooleanCastKind - Returns the cast kind corresponding 314 /// to the conversion from scalar type ScalarTy to the Boolean type. 315 CastKind Sema::ScalarTypeToBooleanCastKind(QualType ScalarTy) { 316 switch (ScalarTy->getScalarTypeKind()) { 317 case Type::STK_Bool: return CK_NoOp; 318 case Type::STK_CPointer: return CK_PointerToBoolean; 319 case Type::STK_BlockPointer: return CK_PointerToBoolean; 320 case Type::STK_ObjCObjectPointer: return CK_PointerToBoolean; 321 case Type::STK_MemberPointer: return CK_MemberPointerToBoolean; 322 case Type::STK_Integral: return CK_IntegralToBoolean; 323 case Type::STK_Floating: return CK_FloatingToBoolean; 324 case Type::STK_IntegralComplex: return CK_IntegralComplexToBoolean; 325 case Type::STK_FloatingComplex: return CK_FloatingComplexToBoolean; 326 } 327 return CK_Invalid; 328 } 329 330 /// \brief Used to prune the decls of Sema's UnusedFileScopedDecls vector. 331 static bool ShouldRemoveFromUnused(Sema *SemaRef, const DeclaratorDecl *D) { 332 if (D->getMostRecentDecl()->isUsed()) 333 return true; 334 335 if (D->hasExternalLinkage()) 336 return true; 337 338 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 339 // UnusedFileScopedDecls stores the first declaration. 340 // The declaration may have become definition so check again. 341 const FunctionDecl *DeclToCheck; 342 if (FD->hasBody(DeclToCheck)) 343 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck); 344 345 // Later redecls may add new information resulting in not having to warn, 346 // so check again. 347 DeclToCheck = FD->getMostRecentDecl(); 348 if (DeclToCheck != FD) 349 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck); 350 } 351 352 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 353 // UnusedFileScopedDecls stores the first declaration. 354 // The declaration may have become definition so check again. 355 const VarDecl *DeclToCheck = VD->getDefinition(); 356 if (DeclToCheck) 357 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck); 358 359 // Later redecls may add new information resulting in not having to warn, 360 // so check again. 361 DeclToCheck = VD->getMostRecentDecl(); 362 if (DeclToCheck != VD) 363 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck); 364 } 365 366 return false; 367 } 368 369 namespace { 370 struct SortUndefinedButUsed { 371 const SourceManager &SM; 372 explicit SortUndefinedButUsed(SourceManager &SM) : SM(SM) {} 373 374 bool operator()(const std::pair<NamedDecl *, SourceLocation> &l, 375 const std::pair<NamedDecl *, SourceLocation> &r) const { 376 if (l.second.isValid() && !r.second.isValid()) 377 return true; 378 if (!l.second.isValid() && r.second.isValid()) 379 return false; 380 if (l.second != r.second) 381 return SM.isBeforeInTranslationUnit(l.second, r.second); 382 return SM.isBeforeInTranslationUnit(l.first->getLocation(), 383 r.first->getLocation()); 384 } 385 }; 386 } 387 388 /// Obtains a sorted list of functions that are undefined but ODR-used. 389 void Sema::getUndefinedButUsed( 390 SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> > &Undefined) { 391 for (llvm::DenseMap<NamedDecl *, SourceLocation>::iterator 392 I = UndefinedButUsed.begin(), E = UndefinedButUsed.end(); 393 I != E; ++I) { 394 NamedDecl *ND = I->first; 395 396 // Ignore attributes that have become invalid. 397 if (ND->isInvalidDecl()) continue; 398 399 // __attribute__((weakref)) is basically a definition. 400 if (ND->hasAttr<WeakRefAttr>()) continue; 401 402 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) { 403 if (FD->isDefined()) 404 continue; 405 if (FD->hasExternalLinkage() && 406 !FD->getMostRecentDecl()->isInlined()) 407 continue; 408 } else { 409 if (cast<VarDecl>(ND)->hasDefinition() != VarDecl::DeclarationOnly) 410 continue; 411 if (ND->hasExternalLinkage()) 412 continue; 413 } 414 415 Undefined.push_back(std::make_pair(ND, I->second)); 416 } 417 418 // Sort (in order of use site) so that we're not dependent on the iteration 419 // order through an llvm::DenseMap. 420 std::sort(Undefined.begin(), Undefined.end(), 421 SortUndefinedButUsed(Context.getSourceManager())); 422 } 423 424 /// checkUndefinedButUsed - Check for undefined objects with internal linkage 425 /// or that are inline. 426 static void checkUndefinedButUsed(Sema &S) { 427 if (S.UndefinedButUsed.empty()) return; 428 429 // Collect all the still-undefined entities with internal linkage. 430 SmallVector<std::pair<NamedDecl *, SourceLocation>, 16> Undefined; 431 S.getUndefinedButUsed(Undefined); 432 if (Undefined.empty()) return; 433 434 for (SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> >::iterator 435 I = Undefined.begin(), E = Undefined.end(); I != E; ++I) { 436 NamedDecl *ND = I->first; 437 438 if (ND->getLinkage() != ExternalLinkage) { 439 S.Diag(ND->getLocation(), diag::warn_undefined_internal) 440 << isa<VarDecl>(ND) << ND; 441 } else { 442 assert(cast<FunctionDecl>(ND)->getMostRecentDecl()->isInlined() && 443 "used object requires definition but isn't inline or internal?"); 444 S.Diag(ND->getLocation(), diag::warn_undefined_inline) << ND; 445 } 446 if (I->second.isValid()) 447 S.Diag(I->second, diag::note_used_here); 448 } 449 } 450 451 void Sema::LoadExternalWeakUndeclaredIdentifiers() { 452 if (!ExternalSource) 453 return; 454 455 SmallVector<std::pair<IdentifierInfo *, WeakInfo>, 4> WeakIDs; 456 ExternalSource->ReadWeakUndeclaredIdentifiers(WeakIDs); 457 for (unsigned I = 0, N = WeakIDs.size(); I != N; ++I) { 458 llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator Pos 459 = WeakUndeclaredIdentifiers.find(WeakIDs[I].first); 460 if (Pos != WeakUndeclaredIdentifiers.end()) 461 continue; 462 463 WeakUndeclaredIdentifiers.insert(WeakIDs[I]); 464 } 465 } 466 467 468 typedef llvm::DenseMap<const CXXRecordDecl*, bool> RecordCompleteMap; 469 470 /// \brief Returns true, if all methods and nested classes of the given 471 /// CXXRecordDecl are defined in this translation unit. 472 /// 473 /// Should only be called from ActOnEndOfTranslationUnit so that all 474 /// definitions are actually read. 475 static bool MethodsAndNestedClassesComplete(const CXXRecordDecl *RD, 476 RecordCompleteMap &MNCComplete) { 477 RecordCompleteMap::iterator Cache = MNCComplete.find(RD); 478 if (Cache != MNCComplete.end()) 479 return Cache->second; 480 if (!RD->isCompleteDefinition()) 481 return false; 482 bool Complete = true; 483 for (DeclContext::decl_iterator I = RD->decls_begin(), 484 E = RD->decls_end(); 485 I != E && Complete; ++I) { 486 if (const CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(*I)) 487 Complete = M->isDefined() || (M->isPure() && !isa<CXXDestructorDecl>(M)); 488 else if (const FunctionTemplateDecl *F = dyn_cast<FunctionTemplateDecl>(*I)) 489 Complete = F->getTemplatedDecl()->isDefined(); 490 else if (const CXXRecordDecl *R = dyn_cast<CXXRecordDecl>(*I)) { 491 if (R->isInjectedClassName()) 492 continue; 493 if (R->hasDefinition()) 494 Complete = MethodsAndNestedClassesComplete(R->getDefinition(), 495 MNCComplete); 496 else 497 Complete = false; 498 } 499 } 500 MNCComplete[RD] = Complete; 501 return Complete; 502 } 503 504 /// \brief Returns true, if the given CXXRecordDecl is fully defined in this 505 /// translation unit, i.e. all methods are defined or pure virtual and all 506 /// friends, friend functions and nested classes are fully defined in this 507 /// translation unit. 508 /// 509 /// Should only be called from ActOnEndOfTranslationUnit so that all 510 /// definitions are actually read. 511 static bool IsRecordFullyDefined(const CXXRecordDecl *RD, 512 RecordCompleteMap &RecordsComplete, 513 RecordCompleteMap &MNCComplete) { 514 RecordCompleteMap::iterator Cache = RecordsComplete.find(RD); 515 if (Cache != RecordsComplete.end()) 516 return Cache->second; 517 bool Complete = MethodsAndNestedClassesComplete(RD, MNCComplete); 518 for (CXXRecordDecl::friend_iterator I = RD->friend_begin(), 519 E = RD->friend_end(); 520 I != E && Complete; ++I) { 521 // Check if friend classes and methods are complete. 522 if (TypeSourceInfo *TSI = (*I)->getFriendType()) { 523 // Friend classes are available as the TypeSourceInfo of the FriendDecl. 524 if (CXXRecordDecl *FriendD = TSI->getType()->getAsCXXRecordDecl()) 525 Complete = MethodsAndNestedClassesComplete(FriendD, MNCComplete); 526 else 527 Complete = false; 528 } else { 529 // Friend functions are available through the NamedDecl of FriendDecl. 530 if (const FunctionDecl *FD = 531 dyn_cast<FunctionDecl>((*I)->getFriendDecl())) 532 Complete = FD->isDefined(); 533 else 534 // This is a template friend, give up. 535 Complete = false; 536 } 537 } 538 RecordsComplete[RD] = Complete; 539 return Complete; 540 } 541 542 /// ActOnEndOfTranslationUnit - This is called at the very end of the 543 /// translation unit when EOF is reached and all but the top-level scope is 544 /// popped. 545 void Sema::ActOnEndOfTranslationUnit() { 546 assert(DelayedDiagnostics.getCurrentPool() == NULL 547 && "reached end of translation unit with a pool attached?"); 548 549 // If code completion is enabled, don't perform any end-of-translation-unit 550 // work. 551 if (PP.isCodeCompletionEnabled()) 552 return; 553 554 // Only complete translation units define vtables and perform implicit 555 // instantiations. 556 if (TUKind == TU_Complete) { 557 DiagnoseUseOfUnimplementedSelectors(); 558 559 // If any dynamic classes have their key function defined within 560 // this translation unit, then those vtables are considered "used" and must 561 // be emitted. 562 for (DynamicClassesType::iterator I = DynamicClasses.begin(ExternalSource), 563 E = DynamicClasses.end(); 564 I != E; ++I) { 565 assert(!(*I)->isDependentType() && 566 "Should not see dependent types here!"); 567 if (const CXXMethodDecl *KeyFunction = Context.getCurrentKeyFunction(*I)) { 568 const FunctionDecl *Definition = 0; 569 if (KeyFunction->hasBody(Definition)) 570 MarkVTableUsed(Definition->getLocation(), *I, true); 571 } 572 } 573 574 // If DefinedUsedVTables ends up marking any virtual member functions it 575 // might lead to more pending template instantiations, which we then need 576 // to instantiate. 577 DefineUsedVTables(); 578 579 // C++: Perform implicit template instantiations. 580 // 581 // FIXME: When we perform these implicit instantiations, we do not 582 // carefully keep track of the point of instantiation (C++ [temp.point]). 583 // This means that name lookup that occurs within the template 584 // instantiation will always happen at the end of the translation unit, 585 // so it will find some names that should not be found. Although this is 586 // common behavior for C++ compilers, it is technically wrong. In the 587 // future, we either need to be able to filter the results of name lookup 588 // or we need to perform template instantiations earlier. 589 PerformPendingInstantiations(); 590 } 591 592 // Remove file scoped decls that turned out to be used. 593 UnusedFileScopedDecls.erase(std::remove_if(UnusedFileScopedDecls.begin(0, 594 true), 595 UnusedFileScopedDecls.end(), 596 std::bind1st(std::ptr_fun(ShouldRemoveFromUnused), 597 this)), 598 UnusedFileScopedDecls.end()); 599 600 if (TUKind == TU_Prefix) { 601 // Translation unit prefixes don't need any of the checking below. 602 TUScope = 0; 603 return; 604 } 605 606 // Check for #pragma weak identifiers that were never declared 607 // FIXME: This will cause diagnostics to be emitted in a non-determinstic 608 // order! Iterating over a densemap like this is bad. 609 LoadExternalWeakUndeclaredIdentifiers(); 610 for (llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator 611 I = WeakUndeclaredIdentifiers.begin(), 612 E = WeakUndeclaredIdentifiers.end(); I != E; ++I) { 613 if (I->second.getUsed()) continue; 614 615 Diag(I->second.getLocation(), diag::warn_weak_identifier_undeclared) 616 << I->first; 617 } 618 619 if (LangOpts.CPlusPlus11 && 620 Diags.getDiagnosticLevel(diag::warn_delegating_ctor_cycle, 621 SourceLocation()) 622 != DiagnosticsEngine::Ignored) 623 CheckDelegatingCtorCycles(); 624 625 if (TUKind == TU_Module) { 626 // If we are building a module, resolve all of the exported declarations 627 // now. 628 if (Module *CurrentModule = PP.getCurrentModule()) { 629 ModuleMap &ModMap = PP.getHeaderSearchInfo().getModuleMap(); 630 631 SmallVector<Module *, 2> Stack; 632 Stack.push_back(CurrentModule); 633 while (!Stack.empty()) { 634 Module *Mod = Stack.back(); 635 Stack.pop_back(); 636 637 // Resolve the exported declarations. 638 // FIXME: Actually complain, once we figure out how to teach the 639 // diagnostic client to deal with complains in the module map at this 640 // point. 641 ModMap.resolveExports(Mod, /*Complain=*/false); 642 643 // Queue the submodules, so their exports will also be resolved. 644 for (Module::submodule_iterator Sub = Mod->submodule_begin(), 645 SubEnd = Mod->submodule_end(); 646 Sub != SubEnd; ++Sub) { 647 Stack.push_back(*Sub); 648 } 649 } 650 } 651 652 // Modules don't need any of the checking below. 653 TUScope = 0; 654 return; 655 } 656 657 // C99 6.9.2p2: 658 // A declaration of an identifier for an object that has file 659 // scope without an initializer, and without a storage-class 660 // specifier or with the storage-class specifier static, 661 // constitutes a tentative definition. If a translation unit 662 // contains one or more tentative definitions for an identifier, 663 // and the translation unit contains no external definition for 664 // that identifier, then the behavior is exactly as if the 665 // translation unit contains a file scope declaration of that 666 // identifier, with the composite type as of the end of the 667 // translation unit, with an initializer equal to 0. 668 llvm::SmallSet<VarDecl *, 32> Seen; 669 for (TentativeDefinitionsType::iterator 670 T = TentativeDefinitions.begin(ExternalSource), 671 TEnd = TentativeDefinitions.end(); 672 T != TEnd; ++T) 673 { 674 VarDecl *VD = (*T)->getActingDefinition(); 675 676 // If the tentative definition was completed, getActingDefinition() returns 677 // null. If we've already seen this variable before, insert()'s second 678 // return value is false. 679 if (VD == 0 || VD->isInvalidDecl() || !Seen.insert(VD)) 680 continue; 681 682 if (const IncompleteArrayType *ArrayT 683 = Context.getAsIncompleteArrayType(VD->getType())) { 684 if (RequireCompleteType(VD->getLocation(), 685 ArrayT->getElementType(), 686 diag::err_tentative_def_incomplete_type_arr)) { 687 VD->setInvalidDecl(); 688 continue; 689 } 690 691 // Set the length of the array to 1 (C99 6.9.2p5). 692 Diag(VD->getLocation(), diag::warn_tentative_incomplete_array); 693 llvm::APInt One(Context.getTypeSize(Context.getSizeType()), true); 694 QualType T = Context.getConstantArrayType(ArrayT->getElementType(), 695 One, ArrayType::Normal, 0); 696 VD->setType(T); 697 } else if (RequireCompleteType(VD->getLocation(), VD->getType(), 698 diag::err_tentative_def_incomplete_type)) 699 VD->setInvalidDecl(); 700 701 CheckCompleteVariableDeclaration(VD); 702 703 // Notify the consumer that we've completed a tentative definition. 704 if (!VD->isInvalidDecl()) 705 Consumer.CompleteTentativeDefinition(VD); 706 707 } 708 709 // If there were errors, disable 'unused' warnings since they will mostly be 710 // noise. 711 if (!Diags.hasErrorOccurred()) { 712 // Output warning for unused file scoped decls. 713 for (UnusedFileScopedDeclsType::iterator 714 I = UnusedFileScopedDecls.begin(ExternalSource), 715 E = UnusedFileScopedDecls.end(); I != E; ++I) { 716 if (ShouldRemoveFromUnused(this, *I)) 717 continue; 718 719 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 720 const FunctionDecl *DiagD; 721 if (!FD->hasBody(DiagD)) 722 DiagD = FD; 723 if (DiagD->isDeleted()) 724 continue; // Deleted functions are supposed to be unused. 725 if (DiagD->isReferenced()) { 726 if (isa<CXXMethodDecl>(DiagD)) 727 Diag(DiagD->getLocation(), diag::warn_unneeded_member_function) 728 << DiagD->getDeclName(); 729 else { 730 if (FD->getStorageClassAsWritten() == SC_Static && 731 !FD->isInlineSpecified() && 732 !SourceMgr.isFromMainFile( 733 SourceMgr.getExpansionLoc(FD->getLocation()))) 734 Diag(DiagD->getLocation(), diag::warn_unneeded_static_internal_decl) 735 << DiagD->getDeclName(); 736 else 737 Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl) 738 << /*function*/0 << DiagD->getDeclName(); 739 } 740 } else { 741 Diag(DiagD->getLocation(), 742 isa<CXXMethodDecl>(DiagD) ? diag::warn_unused_member_function 743 : diag::warn_unused_function) 744 << DiagD->getDeclName(); 745 } 746 } else { 747 const VarDecl *DiagD = cast<VarDecl>(*I)->getDefinition(); 748 if (!DiagD) 749 DiagD = cast<VarDecl>(*I); 750 if (DiagD->isReferenced()) { 751 Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl) 752 << /*variable*/1 << DiagD->getDeclName(); 753 } else { 754 Diag(DiagD->getLocation(), diag::warn_unused_variable) 755 << DiagD->getDeclName(); 756 } 757 } 758 } 759 760 if (ExternalSource) 761 ExternalSource->ReadUndefinedButUsed(UndefinedButUsed); 762 checkUndefinedButUsed(*this); 763 } 764 765 if (Diags.getDiagnosticLevel(diag::warn_unused_private_field, 766 SourceLocation()) 767 != DiagnosticsEngine::Ignored) { 768 RecordCompleteMap RecordsComplete; 769 RecordCompleteMap MNCComplete; 770 for (NamedDeclSetType::iterator I = UnusedPrivateFields.begin(), 771 E = UnusedPrivateFields.end(); I != E; ++I) { 772 const NamedDecl *D = *I; 773 const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext()); 774 if (RD && !RD->isUnion() && 775 IsRecordFullyDefined(RD, RecordsComplete, MNCComplete)) { 776 Diag(D->getLocation(), diag::warn_unused_private_field) 777 << D->getDeclName(); 778 } 779 } 780 } 781 782 // Check we've noticed that we're no longer parsing the initializer for every 783 // variable. If we miss cases, then at best we have a performance issue and 784 // at worst a rejects-valid bug. 785 assert(ParsingInitForAutoVars.empty() && 786 "Didn't unmark var as having its initializer parsed"); 787 788 TUScope = 0; 789 } 790 791 792 //===----------------------------------------------------------------------===// 793 // Helper functions. 794 //===----------------------------------------------------------------------===// 795 796 DeclContext *Sema::getFunctionLevelDeclContext() { 797 DeclContext *DC = CurContext; 798 799 while (true) { 800 if (isa<BlockDecl>(DC) || isa<EnumDecl>(DC)) { 801 DC = DC->getParent(); 802 } else if (isa<CXXMethodDecl>(DC) && 803 cast<CXXMethodDecl>(DC)->getOverloadedOperator() == OO_Call && 804 cast<CXXRecordDecl>(DC->getParent())->isLambda()) { 805 DC = DC->getParent()->getParent(); 806 } 807 else break; 808 } 809 810 return DC; 811 } 812 813 /// getCurFunctionDecl - If inside of a function body, this returns a pointer 814 /// to the function decl for the function being parsed. If we're currently 815 /// in a 'block', this returns the containing context. 816 FunctionDecl *Sema::getCurFunctionDecl() { 817 DeclContext *DC = getFunctionLevelDeclContext(); 818 return dyn_cast<FunctionDecl>(DC); 819 } 820 821 ObjCMethodDecl *Sema::getCurMethodDecl() { 822 DeclContext *DC = getFunctionLevelDeclContext(); 823 return dyn_cast<ObjCMethodDecl>(DC); 824 } 825 826 NamedDecl *Sema::getCurFunctionOrMethodDecl() { 827 DeclContext *DC = getFunctionLevelDeclContext(); 828 if (isa<ObjCMethodDecl>(DC) || isa<FunctionDecl>(DC)) 829 return cast<NamedDecl>(DC); 830 return 0; 831 } 832 833 void Sema::EmitCurrentDiagnostic(unsigned DiagID) { 834 // FIXME: It doesn't make sense to me that DiagID is an incoming argument here 835 // and yet we also use the current diag ID on the DiagnosticsEngine. This has 836 // been made more painfully obvious by the refactor that introduced this 837 // function, but it is possible that the incoming argument can be 838 // eliminnated. If it truly cannot be (for example, there is some reentrancy 839 // issue I am not seeing yet), then there should at least be a clarifying 840 // comment somewhere. 841 if (Optional<TemplateDeductionInfo*> Info = isSFINAEContext()) { 842 switch (DiagnosticIDs::getDiagnosticSFINAEResponse( 843 Diags.getCurrentDiagID())) { 844 case DiagnosticIDs::SFINAE_Report: 845 // We'll report the diagnostic below. 846 break; 847 848 case DiagnosticIDs::SFINAE_SubstitutionFailure: 849 // Count this failure so that we know that template argument deduction 850 // has failed. 851 ++NumSFINAEErrors; 852 853 // Make a copy of this suppressed diagnostic and store it with the 854 // template-deduction information. 855 if (*Info && !(*Info)->hasSFINAEDiagnostic()) { 856 Diagnostic DiagInfo(&Diags); 857 (*Info)->addSFINAEDiagnostic(DiagInfo.getLocation(), 858 PartialDiagnostic(DiagInfo, Context.getDiagAllocator())); 859 } 860 861 Diags.setLastDiagnosticIgnored(); 862 Diags.Clear(); 863 return; 864 865 case DiagnosticIDs::SFINAE_AccessControl: { 866 // Per C++ Core Issue 1170, access control is part of SFINAE. 867 // Additionally, the AccessCheckingSFINAE flag can be used to temporarily 868 // make access control a part of SFINAE for the purposes of checking 869 // type traits. 870 if (!AccessCheckingSFINAE && !getLangOpts().CPlusPlus11) 871 break; 872 873 SourceLocation Loc = Diags.getCurrentDiagLoc(); 874 875 // Suppress this diagnostic. 876 ++NumSFINAEErrors; 877 878 // Make a copy of this suppressed diagnostic and store it with the 879 // template-deduction information. 880 if (*Info && !(*Info)->hasSFINAEDiagnostic()) { 881 Diagnostic DiagInfo(&Diags); 882 (*Info)->addSFINAEDiagnostic(DiagInfo.getLocation(), 883 PartialDiagnostic(DiagInfo, Context.getDiagAllocator())); 884 } 885 886 Diags.setLastDiagnosticIgnored(); 887 Diags.Clear(); 888 889 // Now the diagnostic state is clear, produce a C++98 compatibility 890 // warning. 891 Diag(Loc, diag::warn_cxx98_compat_sfinae_access_control); 892 893 // The last diagnostic which Sema produced was ignored. Suppress any 894 // notes attached to it. 895 Diags.setLastDiagnosticIgnored(); 896 return; 897 } 898 899 case DiagnosticIDs::SFINAE_Suppress: 900 // Make a copy of this suppressed diagnostic and store it with the 901 // template-deduction information; 902 if (*Info) { 903 Diagnostic DiagInfo(&Diags); 904 (*Info)->addSuppressedDiagnostic(DiagInfo.getLocation(), 905 PartialDiagnostic(DiagInfo, Context.getDiagAllocator())); 906 } 907 908 // Suppress this diagnostic. 909 Diags.setLastDiagnosticIgnored(); 910 Diags.Clear(); 911 return; 912 } 913 } 914 915 // Set up the context's printing policy based on our current state. 916 Context.setPrintingPolicy(getPrintingPolicy()); 917 918 // Emit the diagnostic. 919 if (!Diags.EmitCurrentDiagnostic()) 920 return; 921 922 // If this is not a note, and we're in a template instantiation 923 // that is different from the last template instantiation where 924 // we emitted an error, print a template instantiation 925 // backtrace. 926 if (!DiagnosticIDs::isBuiltinNote(DiagID) && 927 !ActiveTemplateInstantiations.empty() && 928 ActiveTemplateInstantiations.back() 929 != LastTemplateInstantiationErrorContext) { 930 PrintInstantiationStack(); 931 LastTemplateInstantiationErrorContext = ActiveTemplateInstantiations.back(); 932 } 933 } 934 935 Sema::SemaDiagnosticBuilder 936 Sema::Diag(SourceLocation Loc, const PartialDiagnostic& PD) { 937 SemaDiagnosticBuilder Builder(Diag(Loc, PD.getDiagID())); 938 PD.Emit(Builder); 939 940 return Builder; 941 } 942 943 /// \brief Looks through the macro-expansion chain for the given 944 /// location, looking for a macro expansion with the given name. 945 /// If one is found, returns true and sets the location to that 946 /// expansion loc. 947 bool Sema::findMacroSpelling(SourceLocation &locref, StringRef name) { 948 SourceLocation loc = locref; 949 if (!loc.isMacroID()) return false; 950 951 // There's no good way right now to look at the intermediate 952 // expansions, so just jump to the expansion location. 953 loc = getSourceManager().getExpansionLoc(loc); 954 955 // If that's written with the name, stop here. 956 SmallVector<char, 16> buffer; 957 if (getPreprocessor().getSpelling(loc, buffer) == name) { 958 locref = loc; 959 return true; 960 } 961 return false; 962 } 963 964 /// \brief Determines the active Scope associated with the given declaration 965 /// context. 966 /// 967 /// This routine maps a declaration context to the active Scope object that 968 /// represents that declaration context in the parser. It is typically used 969 /// from "scope-less" code (e.g., template instantiation, lazy creation of 970 /// declarations) that injects a name for name-lookup purposes and, therefore, 971 /// must update the Scope. 972 /// 973 /// \returns The scope corresponding to the given declaraion context, or NULL 974 /// if no such scope is open. 975 Scope *Sema::getScopeForContext(DeclContext *Ctx) { 976 977 if (!Ctx) 978 return 0; 979 980 Ctx = Ctx->getPrimaryContext(); 981 for (Scope *S = getCurScope(); S; S = S->getParent()) { 982 // Ignore scopes that cannot have declarations. This is important for 983 // out-of-line definitions of static class members. 984 if (S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) 985 if (DeclContext *Entity = static_cast<DeclContext *> (S->getEntity())) 986 if (Ctx == Entity->getPrimaryContext()) 987 return S; 988 } 989 990 return 0; 991 } 992 993 /// \brief Enter a new function scope 994 void Sema::PushFunctionScope() { 995 if (FunctionScopes.size() == 1) { 996 // Use the "top" function scope rather than having to allocate 997 // memory for a new scope. 998 FunctionScopes.back()->Clear(); 999 FunctionScopes.push_back(FunctionScopes.back()); 1000 return; 1001 } 1002 1003 FunctionScopes.push_back(new FunctionScopeInfo(getDiagnostics())); 1004 } 1005 1006 void Sema::PushBlockScope(Scope *BlockScope, BlockDecl *Block) { 1007 FunctionScopes.push_back(new BlockScopeInfo(getDiagnostics(), 1008 BlockScope, Block)); 1009 } 1010 1011 void Sema::PushLambdaScope(CXXRecordDecl *Lambda, 1012 CXXMethodDecl *CallOperator) { 1013 FunctionScopes.push_back(new LambdaScopeInfo(getDiagnostics(), Lambda, 1014 CallOperator)); 1015 } 1016 1017 void Sema::PopFunctionScopeInfo(const AnalysisBasedWarnings::Policy *WP, 1018 const Decl *D, const BlockExpr *blkExpr) { 1019 FunctionScopeInfo *Scope = FunctionScopes.pop_back_val(); 1020 assert(!FunctionScopes.empty() && "mismatched push/pop!"); 1021 1022 // Issue any analysis-based warnings. 1023 if (WP && D) 1024 AnalysisWarnings.IssueWarnings(*WP, Scope, D, blkExpr); 1025 else { 1026 for (SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator 1027 i = Scope->PossiblyUnreachableDiags.begin(), 1028 e = Scope->PossiblyUnreachableDiags.end(); 1029 i != e; ++i) { 1030 const sema::PossiblyUnreachableDiag &D = *i; 1031 Diag(D.Loc, D.PD); 1032 } 1033 } 1034 1035 if (FunctionScopes.back() != Scope) { 1036 delete Scope; 1037 } 1038 } 1039 1040 void Sema::PushCompoundScope() { 1041 getCurFunction()->CompoundScopes.push_back(CompoundScopeInfo()); 1042 } 1043 1044 void Sema::PopCompoundScope() { 1045 FunctionScopeInfo *CurFunction = getCurFunction(); 1046 assert(!CurFunction->CompoundScopes.empty() && "mismatched push/pop"); 1047 1048 CurFunction->CompoundScopes.pop_back(); 1049 } 1050 1051 /// \brief Determine whether any errors occurred within this function/method/ 1052 /// block. 1053 bool Sema::hasAnyUnrecoverableErrorsInThisFunction() const { 1054 return getCurFunction()->ErrorTrap.hasUnrecoverableErrorOccurred(); 1055 } 1056 1057 BlockScopeInfo *Sema::getCurBlock() { 1058 if (FunctionScopes.empty()) 1059 return 0; 1060 1061 return dyn_cast<BlockScopeInfo>(FunctionScopes.back()); 1062 } 1063 1064 LambdaScopeInfo *Sema::getCurLambda() { 1065 if (FunctionScopes.empty()) 1066 return 0; 1067 1068 return dyn_cast<LambdaScopeInfo>(FunctionScopes.back()); 1069 } 1070 1071 void Sema::ActOnComment(SourceRange Comment) { 1072 if (!LangOpts.RetainCommentsFromSystemHeaders && 1073 SourceMgr.isInSystemHeader(Comment.getBegin())) 1074 return; 1075 RawComment RC(SourceMgr, Comment); 1076 if (RC.isAlmostTrailingComment()) { 1077 SourceRange MagicMarkerRange(Comment.getBegin(), 1078 Comment.getBegin().getLocWithOffset(3)); 1079 StringRef MagicMarkerText; 1080 switch (RC.getKind()) { 1081 case RawComment::RCK_OrdinaryBCPL: 1082 MagicMarkerText = "///<"; 1083 break; 1084 case RawComment::RCK_OrdinaryC: 1085 MagicMarkerText = "/**<"; 1086 break; 1087 default: 1088 llvm_unreachable("if this is an almost Doxygen comment, " 1089 "it should be ordinary"); 1090 } 1091 Diag(Comment.getBegin(), diag::warn_not_a_doxygen_trailing_member_comment) << 1092 FixItHint::CreateReplacement(MagicMarkerRange, MagicMarkerText); 1093 } 1094 Context.addComment(RC); 1095 } 1096 1097 // Pin this vtable to this file. 1098 ExternalSemaSource::~ExternalSemaSource() {} 1099 1100 void ExternalSemaSource::ReadMethodPool(Selector Sel) { } 1101 1102 void ExternalSemaSource::ReadKnownNamespaces( 1103 SmallVectorImpl<NamespaceDecl *> &Namespaces) { 1104 } 1105 1106 void ExternalSemaSource::ReadUndefinedButUsed( 1107 llvm::DenseMap<NamedDecl *, SourceLocation> &Undefined) { 1108 } 1109 1110 void PrettyDeclStackTraceEntry::print(raw_ostream &OS) const { 1111 SourceLocation Loc = this->Loc; 1112 if (!Loc.isValid() && TheDecl) Loc = TheDecl->getLocation(); 1113 if (Loc.isValid()) { 1114 Loc.print(OS, S.getSourceManager()); 1115 OS << ": "; 1116 } 1117 OS << Message; 1118 1119 if (TheDecl && isa<NamedDecl>(TheDecl)) { 1120 std::string Name = cast<NamedDecl>(TheDecl)->getNameAsString(); 1121 if (!Name.empty()) 1122 OS << " '" << Name << '\''; 1123 } 1124 1125 OS << '\n'; 1126 } 1127 1128 /// \brief Figure out if an expression could be turned into a call. 1129 /// 1130 /// Use this when trying to recover from an error where the programmer may have 1131 /// written just the name of a function instead of actually calling it. 1132 /// 1133 /// \param E - The expression to examine. 1134 /// \param ZeroArgCallReturnTy - If the expression can be turned into a call 1135 /// with no arguments, this parameter is set to the type returned by such a 1136 /// call; otherwise, it is set to an empty QualType. 1137 /// \param OverloadSet - If the expression is an overloaded function 1138 /// name, this parameter is populated with the decls of the various overloads. 1139 bool Sema::isExprCallable(const Expr &E, QualType &ZeroArgCallReturnTy, 1140 UnresolvedSetImpl &OverloadSet) { 1141 ZeroArgCallReturnTy = QualType(); 1142 OverloadSet.clear(); 1143 1144 if (E.getType() == Context.OverloadTy) { 1145 OverloadExpr::FindResult FR = OverloadExpr::find(const_cast<Expr*>(&E)); 1146 const OverloadExpr *Overloads = FR.Expression; 1147 1148 for (OverloadExpr::decls_iterator it = Overloads->decls_begin(), 1149 DeclsEnd = Overloads->decls_end(); it != DeclsEnd; ++it) { 1150 OverloadSet.addDecl(*it); 1151 1152 // Check whether the function is a non-template which takes no 1153 // arguments. 1154 if (const FunctionDecl *OverloadDecl 1155 = dyn_cast<FunctionDecl>((*it)->getUnderlyingDecl())) { 1156 if (OverloadDecl->getMinRequiredArguments() == 0) 1157 ZeroArgCallReturnTy = OverloadDecl->getResultType(); 1158 } 1159 } 1160 1161 // Ignore overloads that are pointer-to-member constants. 1162 if (FR.HasFormOfMemberPointer) 1163 return false; 1164 1165 return true; 1166 } 1167 1168 if (const DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E.IgnoreParens())) { 1169 if (const FunctionDecl *Fun = dyn_cast<FunctionDecl>(DeclRef->getDecl())) { 1170 if (Fun->getMinRequiredArguments() == 0) 1171 ZeroArgCallReturnTy = Fun->getResultType(); 1172 return true; 1173 } 1174 } 1175 1176 // We don't have an expression that's convenient to get a FunctionDecl from, 1177 // but we can at least check if the type is "function of 0 arguments". 1178 QualType ExprTy = E.getType(); 1179 const FunctionType *FunTy = NULL; 1180 QualType PointeeTy = ExprTy->getPointeeType(); 1181 if (!PointeeTy.isNull()) 1182 FunTy = PointeeTy->getAs<FunctionType>(); 1183 if (!FunTy) 1184 FunTy = ExprTy->getAs<FunctionType>(); 1185 if (!FunTy && ExprTy == Context.BoundMemberTy) { 1186 // Look for the bound-member type. If it's still overloaded, give up, 1187 // although we probably should have fallen into the OverloadExpr case above 1188 // if we actually have an overloaded bound member. 1189 QualType BoundMemberTy = Expr::findBoundMemberType(&E); 1190 if (!BoundMemberTy.isNull()) 1191 FunTy = BoundMemberTy->castAs<FunctionType>(); 1192 } 1193 1194 if (const FunctionProtoType *FPT = 1195 dyn_cast_or_null<FunctionProtoType>(FunTy)) { 1196 if (FPT->getNumArgs() == 0) 1197 ZeroArgCallReturnTy = FunTy->getResultType(); 1198 return true; 1199 } 1200 return false; 1201 } 1202 1203 /// \brief Give notes for a set of overloads. 1204 /// 1205 /// A companion to isExprCallable. In cases when the name that the programmer 1206 /// wrote was an overloaded function, we may be able to make some guesses about 1207 /// plausible overloads based on their return types; such guesses can be handed 1208 /// off to this method to be emitted as notes. 1209 /// 1210 /// \param Overloads - The overloads to note. 1211 /// \param FinalNoteLoc - If we've suppressed printing some overloads due to 1212 /// -fshow-overloads=best, this is the location to attach to the note about too 1213 /// many candidates. Typically this will be the location of the original 1214 /// ill-formed expression. 1215 static void noteOverloads(Sema &S, const UnresolvedSetImpl &Overloads, 1216 const SourceLocation FinalNoteLoc) { 1217 int ShownOverloads = 0; 1218 int SuppressedOverloads = 0; 1219 for (UnresolvedSetImpl::iterator It = Overloads.begin(), 1220 DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) { 1221 // FIXME: Magic number for max shown overloads stolen from 1222 // OverloadCandidateSet::NoteCandidates. 1223 if (ShownOverloads >= 4 && S.Diags.getShowOverloads() == Ovl_Best) { 1224 ++SuppressedOverloads; 1225 continue; 1226 } 1227 1228 NamedDecl *Fn = (*It)->getUnderlyingDecl(); 1229 S.Diag(Fn->getLocation(), diag::note_possible_target_of_call); 1230 ++ShownOverloads; 1231 } 1232 1233 if (SuppressedOverloads) 1234 S.Diag(FinalNoteLoc, diag::note_ovl_too_many_candidates) 1235 << SuppressedOverloads; 1236 } 1237 1238 static void notePlausibleOverloads(Sema &S, SourceLocation Loc, 1239 const UnresolvedSetImpl &Overloads, 1240 bool (*IsPlausibleResult)(QualType)) { 1241 if (!IsPlausibleResult) 1242 return noteOverloads(S, Overloads, Loc); 1243 1244 UnresolvedSet<2> PlausibleOverloads; 1245 for (OverloadExpr::decls_iterator It = Overloads.begin(), 1246 DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) { 1247 const FunctionDecl *OverloadDecl = cast<FunctionDecl>(*It); 1248 QualType OverloadResultTy = OverloadDecl->getResultType(); 1249 if (IsPlausibleResult(OverloadResultTy)) 1250 PlausibleOverloads.addDecl(It.getDecl()); 1251 } 1252 noteOverloads(S, PlausibleOverloads, Loc); 1253 } 1254 1255 /// Determine whether the given expression can be called by just 1256 /// putting parentheses after it. Notably, expressions with unary 1257 /// operators can't be because the unary operator will start parsing 1258 /// outside the call. 1259 static bool IsCallableWithAppend(Expr *E) { 1260 E = E->IgnoreImplicit(); 1261 return (!isa<CStyleCastExpr>(E) && 1262 !isa<UnaryOperator>(E) && 1263 !isa<BinaryOperator>(E) && 1264 !isa<CXXOperatorCallExpr>(E)); 1265 } 1266 1267 bool Sema::tryToRecoverWithCall(ExprResult &E, const PartialDiagnostic &PD, 1268 bool ForceComplain, 1269 bool (*IsPlausibleResult)(QualType)) { 1270 SourceLocation Loc = E.get()->getExprLoc(); 1271 SourceRange Range = E.get()->getSourceRange(); 1272 1273 QualType ZeroArgCallTy; 1274 UnresolvedSet<4> Overloads; 1275 if (isExprCallable(*E.get(), ZeroArgCallTy, Overloads) && 1276 !ZeroArgCallTy.isNull() && 1277 (!IsPlausibleResult || IsPlausibleResult(ZeroArgCallTy))) { 1278 // At this point, we know E is potentially callable with 0 1279 // arguments and that it returns something of a reasonable type, 1280 // so we can emit a fixit and carry on pretending that E was 1281 // actually a CallExpr. 1282 SourceLocation ParenInsertionLoc = 1283 PP.getLocForEndOfToken(Range.getEnd()); 1284 Diag(Loc, PD) 1285 << /*zero-arg*/ 1 << Range 1286 << (IsCallableWithAppend(E.get()) 1287 ? FixItHint::CreateInsertion(ParenInsertionLoc, "()") 1288 : FixItHint()); 1289 notePlausibleOverloads(*this, Loc, Overloads, IsPlausibleResult); 1290 1291 // FIXME: Try this before emitting the fixit, and suppress diagnostics 1292 // while doing so. 1293 E = ActOnCallExpr(0, E.take(), ParenInsertionLoc, 1294 MultiExprArg(), ParenInsertionLoc.getLocWithOffset(1)); 1295 return true; 1296 } 1297 1298 if (!ForceComplain) return false; 1299 1300 Diag(Loc, PD) << /*not zero-arg*/ 0 << Range; 1301 notePlausibleOverloads(*this, Loc, Overloads, IsPlausibleResult); 1302 E = ExprError(); 1303 return true; 1304 } 1305 1306 IdentifierInfo *Sema::getSuperIdentifier() const { 1307 if (!Ident_super) 1308 Ident_super = &Context.Idents.get("super"); 1309 return Ident_super; 1310 } 1311