Sema.cpp revision 467dc88512b4ba4bb16e274ea3771dc1415d31da
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 "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 "clang/Sema/CXXFieldCollector.h" 22#include "clang/Sema/TemplateDeduction.h" 23#include "clang/Sema/ExternalSemaSource.h" 24#include "clang/Sema/ObjCMethodList.h" 25#include "clang/Sema/PrettyDeclStackTrace.h" 26#include "clang/Sema/Scope.h" 27#include "clang/Sema/ScopeInfo.h" 28#include "clang/Sema/SemaConsumer.h" 29#include "clang/AST/ASTContext.h" 30#include "clang/AST/ASTDiagnostic.h" 31#include "clang/AST/DeclCXX.h" 32#include "clang/AST/DeclObjC.h" 33#include "clang/AST/Expr.h" 34#include "clang/AST/ExprCXX.h" 35#include "clang/AST/StmtCXX.h" 36#include "clang/Lex/Preprocessor.h" 37#include "clang/Basic/PartialDiagnostic.h" 38#include "clang/Basic/TargetInfo.h" 39using namespace clang; 40using namespace sema; 41 42FunctionScopeInfo::~FunctionScopeInfo() { } 43 44void FunctionScopeInfo::Clear() { 45 HasBranchProtectedScope = false; 46 HasBranchIntoScope = false; 47 HasIndirectGoto = false; 48 49 SwitchStack.clear(); 50 Returns.clear(); 51 ErrorTrap.reset(); 52 PossiblyUnreachableDiags.clear(); 53} 54 55BlockScopeInfo::~BlockScopeInfo() { } 56 57void Sema::ActOnTranslationUnitScope(Scope *S) { 58 TUScope = S; 59 PushDeclContext(S, Context.getTranslationUnitDecl()); 60 61 VAListTagName = PP.getIdentifierInfo("__va_list_tag"); 62 63 if (PP.getLangOptions().ObjC1) { 64 // Synthesize "@class Protocol; 65 if (Context.getObjCProtoType().isNull()) { 66 ObjCInterfaceDecl *ProtocolDecl = 67 ObjCInterfaceDecl::Create(Context, CurContext, SourceLocation(), 68 &Context.Idents.get("Protocol"), 69 SourceLocation(), true); 70 Context.setObjCProtoType(Context.getObjCInterfaceType(ProtocolDecl)); 71 PushOnScopeChains(ProtocolDecl, TUScope, false); 72 } 73 } 74} 75 76Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer, 77 TranslationUnitKind TUKind, 78 CodeCompleteConsumer *CodeCompleter) 79 : TheTargetAttributesSema(0), FPFeatures(pp.getLangOptions()), 80 LangOpts(pp.getLangOptions()), PP(pp), Context(ctxt), Consumer(consumer), 81 Diags(PP.getDiagnostics()), SourceMgr(PP.getSourceManager()), 82 CollectStats(false), ExternalSource(0), CodeCompleter(CodeCompleter), 83 CurContext(0), PackContext(0), MSStructPragmaOn(false), VisContext(0), 84 ExprNeedsCleanups(0), LateTemplateParser(0), OpaqueParser(0), 85 IdResolver(pp.getLangOptions()), CXXTypeInfoDecl(0), MSVCGuidDecl(0), 86 GlobalNewDeleteDeclared(false), 87 ObjCShouldCallSuperDealloc(false), 88 TUKind(TUKind), 89 NumSFINAEErrors(0), SuppressAccessChecking(false), 90 AccessCheckingSFINAE(false), InNonInstantiationSFINAEContext(false), 91 NonInstantiationEntries(0), ArgumentPackSubstitutionIndex(-1), 92 CurrentInstantiationScope(0), TyposCorrected(0), 93 AnalysisWarnings(*this) 94{ 95 TUScope = 0; 96 LoadedExternalKnownNamespaces = false; 97 98 if (getLangOptions().CPlusPlus) 99 FieldCollector.reset(new CXXFieldCollector()); 100 101 // Tell diagnostics how to render things from the AST library. 102 PP.getDiagnostics().SetArgToStringFn(&FormatASTNodeDiagnosticArgument, 103 &Context); 104 105 ExprEvalContexts.push_back( 106 ExpressionEvaluationContextRecord(PotentiallyEvaluated, 0, false)); 107 108 FunctionScopes.push_back(new FunctionScopeInfo(Diags)); 109} 110 111void Sema::Initialize() { 112 // Tell the AST consumer about this Sema object. 113 Consumer.Initialize(Context); 114 115 // FIXME: Isn't this redundant with the initialization above? 116 if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer)) 117 SC->InitializeSema(*this); 118 119 // Tell the external Sema source about this Sema object. 120 if (ExternalSemaSource *ExternalSema 121 = dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource())) 122 ExternalSema->InitializeSema(*this); 123 124 // Initialize predefined 128-bit integer types, if needed. 125 if (PP.getTargetInfo().getPointerWidth(0) >= 64) { 126 // If either of the 128-bit integer types are unavailable to name lookup, 127 // define them now. 128 DeclarationName Int128 = &Context.Idents.get("__int128_t"); 129 if (IdentifierResolver::begin(Int128) == IdentifierResolver::end()) 130 PushOnScopeChains(Context.getInt128Decl(), TUScope); 131 132 DeclarationName UInt128 = &Context.Idents.get("__uint128_t"); 133 if (IdentifierResolver::begin(UInt128) == IdentifierResolver::end()) 134 PushOnScopeChains(Context.getUInt128Decl(), TUScope); 135 } 136 137 138 // Initialize predefined Objective-C types: 139 if (PP.getLangOptions().ObjC1) { 140 // If 'SEL' does not yet refer to any declarations, make it refer to the 141 // predefined 'SEL'. 142 DeclarationName SEL = &Context.Idents.get("SEL"); 143 if (IdentifierResolver::begin(SEL) == IdentifierResolver::end()) 144 PushOnScopeChains(Context.getObjCSelDecl(), TUScope); 145 146 // If 'id' does not yet refer to any declarations, make it refer to the 147 // predefined 'id'. 148 DeclarationName Id = &Context.Idents.get("id"); 149 if (IdentifierResolver::begin(Id) == IdentifierResolver::end()) 150 PushOnScopeChains(Context.getObjCIdDecl(), TUScope); 151 152 // Create the built-in typedef for 'Class'. 153 DeclarationName Class = &Context.Idents.get("Class"); 154 if (IdentifierResolver::begin(Class) == IdentifierResolver::end()) 155 PushOnScopeChains(Context.getObjCClassDecl(), TUScope); 156 } 157} 158 159Sema::~Sema() { 160 if (PackContext) FreePackedContext(); 161 if (VisContext) FreeVisContext(); 162 delete TheTargetAttributesSema; 163 MSStructPragmaOn = false; 164 // Kill all the active scopes. 165 for (unsigned I = 1, E = FunctionScopes.size(); I != E; ++I) 166 delete FunctionScopes[I]; 167 if (FunctionScopes.size() == 1) 168 delete FunctionScopes[0]; 169 170 // Tell the SemaConsumer to forget about us; we're going out of scope. 171 if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer)) 172 SC->ForgetSema(); 173 174 // Detach from the external Sema source. 175 if (ExternalSemaSource *ExternalSema 176 = dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource())) 177 ExternalSema->ForgetSema(); 178} 179 180 181/// makeUnavailableInSystemHeader - There is an error in the current 182/// context. If we're still in a system header, and we can plausibly 183/// make the relevant declaration unavailable instead of erroring, do 184/// so and return true. 185bool Sema::makeUnavailableInSystemHeader(SourceLocation loc, 186 StringRef msg) { 187 // If we're not in a function, it's an error. 188 FunctionDecl *fn = dyn_cast<FunctionDecl>(CurContext); 189 if (!fn) return false; 190 191 // If we're in template instantiation, it's an error. 192 if (!ActiveTemplateInstantiations.empty()) 193 return false; 194 195 // If that function's not in a system header, it's an error. 196 if (!Context.getSourceManager().isInSystemHeader(loc)) 197 return false; 198 199 // If the function is already unavailable, it's not an error. 200 if (fn->hasAttr<UnavailableAttr>()) return true; 201 202 fn->addAttr(new (Context) UnavailableAttr(loc, Context, msg)); 203 return true; 204} 205 206ASTMutationListener *Sema::getASTMutationListener() const { 207 return getASTConsumer().GetASTMutationListener(); 208} 209 210/// \brief Print out statistics about the semantic analysis. 211void Sema::PrintStats() const { 212 llvm::errs() << "\n*** Semantic Analysis Stats:\n"; 213 llvm::errs() << NumSFINAEErrors << " SFINAE diagnostics trapped.\n"; 214 215 BumpAlloc.PrintStats(); 216 AnalysisWarnings.PrintStats(); 217} 218 219/// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast. 220/// If there is already an implicit cast, merge into the existing one. 221/// The result is of the given category. 222ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty, 223 CastKind Kind, ExprValueKind VK, 224 const CXXCastPath *BasePath, 225 CheckedConversionKind CCK) { 226 QualType ExprTy = Context.getCanonicalType(E->getType()); 227 QualType TypeTy = Context.getCanonicalType(Ty); 228 229 if (ExprTy == TypeTy) 230 return Owned(E); 231 232 if (getLangOptions().ObjCAutoRefCount) 233 CheckObjCARCConversion(SourceRange(), Ty, E, CCK); 234 235 // If this is a derived-to-base cast to a through a virtual base, we 236 // need a vtable. 237 if (Kind == CK_DerivedToBase && 238 BasePathInvolvesVirtualBase(*BasePath)) { 239 QualType T = E->getType(); 240 if (const PointerType *Pointer = T->getAs<PointerType>()) 241 T = Pointer->getPointeeType(); 242 if (const RecordType *RecordTy = T->getAs<RecordType>()) 243 MarkVTableUsed(E->getLocStart(), 244 cast<CXXRecordDecl>(RecordTy->getDecl())); 245 } 246 247 if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(E)) { 248 if (ImpCast->getCastKind() == Kind && (!BasePath || BasePath->empty())) { 249 ImpCast->setType(Ty); 250 ImpCast->setValueKind(VK); 251 return Owned(E); 252 } 253 } 254 255 return Owned(ImplicitCastExpr::Create(Context, Ty, Kind, E, BasePath, VK)); 256} 257 258/// ScalarTypeToBooleanCastKind - Returns the cast kind corresponding 259/// to the conversion from scalar type ScalarTy to the Boolean type. 260CastKind Sema::ScalarTypeToBooleanCastKind(QualType ScalarTy) { 261 switch (ScalarTy->getScalarTypeKind()) { 262 case Type::STK_Bool: return CK_NoOp; 263 case Type::STK_Pointer: return CK_PointerToBoolean; 264 case Type::STK_MemberPointer: return CK_MemberPointerToBoolean; 265 case Type::STK_Integral: return CK_IntegralToBoolean; 266 case Type::STK_Floating: return CK_FloatingToBoolean; 267 case Type::STK_IntegralComplex: return CK_IntegralComplexToBoolean; 268 case Type::STK_FloatingComplex: return CK_FloatingComplexToBoolean; 269 } 270 return CK_Invalid; 271} 272 273ExprValueKind Sema::CastCategory(Expr *E) { 274 Expr::Classification Classification = E->Classify(Context); 275 return Classification.isRValue() ? VK_RValue : 276 (Classification.isLValue() ? VK_LValue : VK_XValue); 277} 278 279/// \brief Used to prune the decls of Sema's UnusedFileScopedDecls vector. 280static bool ShouldRemoveFromUnused(Sema *SemaRef, const DeclaratorDecl *D) { 281 if (D->isUsed()) 282 return true; 283 284 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 285 // UnusedFileScopedDecls stores the first declaration. 286 // The declaration may have become definition so check again. 287 const FunctionDecl *DeclToCheck; 288 if (FD->hasBody(DeclToCheck)) 289 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck); 290 291 // Later redecls may add new information resulting in not having to warn, 292 // so check again. 293 DeclToCheck = FD->getMostRecentDeclaration(); 294 if (DeclToCheck != FD) 295 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck); 296 } 297 298 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { 299 // UnusedFileScopedDecls stores the first declaration. 300 // The declaration may have become definition so check again. 301 const VarDecl *DeclToCheck = VD->getDefinition(); 302 if (DeclToCheck) 303 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck); 304 305 // Later redecls may add new information resulting in not having to warn, 306 // so check again. 307 DeclToCheck = VD->getMostRecentDeclaration(); 308 if (DeclToCheck != VD) 309 return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck); 310 } 311 312 return false; 313} 314 315namespace { 316 struct UndefinedInternal { 317 NamedDecl *decl; 318 FullSourceLoc useLoc; 319 320 UndefinedInternal(NamedDecl *decl, FullSourceLoc useLoc) 321 : decl(decl), useLoc(useLoc) {} 322 }; 323 324 bool operator<(const UndefinedInternal &l, const UndefinedInternal &r) { 325 return l.useLoc.isBeforeInTranslationUnitThan(r.useLoc); 326 } 327} 328 329/// checkUndefinedInternals - Check for undefined objects with internal linkage. 330static void checkUndefinedInternals(Sema &S) { 331 if (S.UndefinedInternals.empty()) return; 332 333 // Collect all the still-undefined entities with internal linkage. 334 SmallVector<UndefinedInternal, 16> undefined; 335 for (llvm::DenseMap<NamedDecl*,SourceLocation>::iterator 336 i = S.UndefinedInternals.begin(), e = S.UndefinedInternals.end(); 337 i != e; ++i) { 338 NamedDecl *decl = i->first; 339 340 // Ignore attributes that have become invalid. 341 if (decl->isInvalidDecl()) continue; 342 343 // __attribute__((weakref)) is basically a definition. 344 if (decl->hasAttr<WeakRefAttr>()) continue; 345 346 if (FunctionDecl *fn = dyn_cast<FunctionDecl>(decl)) { 347 if (fn->isPure() || fn->hasBody()) 348 continue; 349 } else { 350 if (cast<VarDecl>(decl)->hasDefinition() != VarDecl::DeclarationOnly) 351 continue; 352 } 353 354 // We build a FullSourceLoc so that we can sort with array_pod_sort. 355 FullSourceLoc loc(i->second, S.Context.getSourceManager()); 356 undefined.push_back(UndefinedInternal(decl, loc)); 357 } 358 359 if (undefined.empty()) return; 360 361 // Sort (in order of use site) so that we're not (as) dependent on 362 // the iteration order through an llvm::DenseMap. 363 llvm::array_pod_sort(undefined.begin(), undefined.end()); 364 365 for (SmallVectorImpl<UndefinedInternal>::iterator 366 i = undefined.begin(), e = undefined.end(); i != e; ++i) { 367 NamedDecl *decl = i->decl; 368 S.Diag(decl->getLocation(), diag::warn_undefined_internal) 369 << isa<VarDecl>(decl) << decl; 370 S.Diag(i->useLoc, diag::note_used_here); 371 } 372} 373 374void Sema::LoadExternalWeakUndeclaredIdentifiers() { 375 if (!ExternalSource) 376 return; 377 378 SmallVector<std::pair<IdentifierInfo *, WeakInfo>, 4> WeakIDs; 379 ExternalSource->ReadWeakUndeclaredIdentifiers(WeakIDs); 380 for (unsigned I = 0, N = WeakIDs.size(); I != N; ++I) { 381 llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator Pos 382 = WeakUndeclaredIdentifiers.find(WeakIDs[I].first); 383 if (Pos != WeakUndeclaredIdentifiers.end()) 384 continue; 385 386 WeakUndeclaredIdentifiers.insert(WeakIDs[I]); 387 } 388} 389 390/// ActOnEndOfTranslationUnit - This is called at the very end of the 391/// translation unit when EOF is reached and all but the top-level scope is 392/// popped. 393void Sema::ActOnEndOfTranslationUnit() { 394 // Only complete translation units define vtables and perform implicit 395 // instantiations. 396 if (TUKind == TU_Complete) { 397 // If any dynamic classes have their key function defined within 398 // this translation unit, then those vtables are considered "used" and must 399 // be emitted. 400 for (DynamicClassesType::iterator I = DynamicClasses.begin(ExternalSource), 401 E = DynamicClasses.end(); 402 I != E; ++I) { 403 assert(!(*I)->isDependentType() && 404 "Should not see dependent types here!"); 405 if (const CXXMethodDecl *KeyFunction = Context.getKeyFunction(*I)) { 406 const FunctionDecl *Definition = 0; 407 if (KeyFunction->hasBody(Definition)) 408 MarkVTableUsed(Definition->getLocation(), *I, true); 409 } 410 } 411 412 // If DefinedUsedVTables ends up marking any virtual member functions it 413 // might lead to more pending template instantiations, which we then need 414 // to instantiate. 415 DefineUsedVTables(); 416 417 // C++: Perform implicit template instantiations. 418 // 419 // FIXME: When we perform these implicit instantiations, we do not 420 // carefully keep track of the point of instantiation (C++ [temp.point]). 421 // This means that name lookup that occurs within the template 422 // instantiation will always happen at the end of the translation unit, 423 // so it will find some names that should not be found. Although this is 424 // common behavior for C++ compilers, it is technically wrong. In the 425 // future, we either need to be able to filter the results of name lookup 426 // or we need to perform template instantiations earlier. 427 PerformPendingInstantiations(); 428 } 429 430 // Remove file scoped decls that turned out to be used. 431 UnusedFileScopedDecls.erase(std::remove_if(UnusedFileScopedDecls.begin(0, 432 true), 433 UnusedFileScopedDecls.end(), 434 std::bind1st(std::ptr_fun(ShouldRemoveFromUnused), 435 this)), 436 UnusedFileScopedDecls.end()); 437 438 if (TUKind == TU_Prefix) { 439 // Translation unit prefixes don't need any of the checking below. 440 TUScope = 0; 441 return; 442 } 443 444 // Check for #pragma weak identifiers that were never declared 445 // FIXME: This will cause diagnostics to be emitted in a non-determinstic 446 // order! Iterating over a densemap like this is bad. 447 LoadExternalWeakUndeclaredIdentifiers(); 448 for (llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator 449 I = WeakUndeclaredIdentifiers.begin(), 450 E = WeakUndeclaredIdentifiers.end(); I != E; ++I) { 451 if (I->second.getUsed()) continue; 452 453 Diag(I->second.getLocation(), diag::warn_weak_identifier_undeclared) 454 << I->first; 455 } 456 457 if (TUKind == TU_Module) { 458 // Modules don't need any of the checking below. 459 TUScope = 0; 460 return; 461 } 462 463 // C99 6.9.2p2: 464 // A declaration of an identifier for an object that has file 465 // scope without an initializer, and without a storage-class 466 // specifier or with the storage-class specifier static, 467 // constitutes a tentative definition. If a translation unit 468 // contains one or more tentative definitions for an identifier, 469 // and the translation unit contains no external definition for 470 // that identifier, then the behavior is exactly as if the 471 // translation unit contains a file scope declaration of that 472 // identifier, with the composite type as of the end of the 473 // translation unit, with an initializer equal to 0. 474 llvm::SmallSet<VarDecl *, 32> Seen; 475 for (TentativeDefinitionsType::iterator 476 T = TentativeDefinitions.begin(ExternalSource), 477 TEnd = TentativeDefinitions.end(); 478 T != TEnd; ++T) 479 { 480 VarDecl *VD = (*T)->getActingDefinition(); 481 482 // If the tentative definition was completed, getActingDefinition() returns 483 // null. If we've already seen this variable before, insert()'s second 484 // return value is false. 485 if (VD == 0 || VD->isInvalidDecl() || !Seen.insert(VD)) 486 continue; 487 488 if (const IncompleteArrayType *ArrayT 489 = Context.getAsIncompleteArrayType(VD->getType())) { 490 if (RequireCompleteType(VD->getLocation(), 491 ArrayT->getElementType(), 492 diag::err_tentative_def_incomplete_type_arr)) { 493 VD->setInvalidDecl(); 494 continue; 495 } 496 497 // Set the length of the array to 1 (C99 6.9.2p5). 498 Diag(VD->getLocation(), diag::warn_tentative_incomplete_array); 499 llvm::APInt One(Context.getTypeSize(Context.getSizeType()), true); 500 QualType T = Context.getConstantArrayType(ArrayT->getElementType(), 501 One, ArrayType::Normal, 0); 502 VD->setType(T); 503 } else if (RequireCompleteType(VD->getLocation(), VD->getType(), 504 diag::err_tentative_def_incomplete_type)) 505 VD->setInvalidDecl(); 506 507 // Notify the consumer that we've completed a tentative definition. 508 if (!VD->isInvalidDecl()) 509 Consumer.CompleteTentativeDefinition(VD); 510 511 } 512 513 if (LangOpts.CPlusPlus0x && 514 Diags.getDiagnosticLevel(diag::warn_delegating_ctor_cycle, 515 SourceLocation()) 516 != Diagnostic::Ignored) 517 CheckDelegatingCtorCycles(); 518 519 // If there were errors, disable 'unused' warnings since they will mostly be 520 // noise. 521 if (!Diags.hasErrorOccurred()) { 522 // Output warning for unused file scoped decls. 523 for (UnusedFileScopedDeclsType::iterator 524 I = UnusedFileScopedDecls.begin(ExternalSource), 525 E = UnusedFileScopedDecls.end(); I != E; ++I) { 526 if (ShouldRemoveFromUnused(this, *I)) 527 continue; 528 529 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 530 const FunctionDecl *DiagD; 531 if (!FD->hasBody(DiagD)) 532 DiagD = FD; 533 if (DiagD->isDeleted()) 534 continue; // Deleted functions are supposed to be unused. 535 if (DiagD->isReferenced()) { 536 if (isa<CXXMethodDecl>(DiagD)) 537 Diag(DiagD->getLocation(), diag::warn_unneeded_member_function) 538 << DiagD->getDeclName(); 539 else 540 Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl) 541 << /*function*/0 << DiagD->getDeclName(); 542 } else { 543 Diag(DiagD->getLocation(), 544 isa<CXXMethodDecl>(DiagD) ? diag::warn_unused_member_function 545 : diag::warn_unused_function) 546 << DiagD->getDeclName(); 547 } 548 } else { 549 const VarDecl *DiagD = cast<VarDecl>(*I)->getDefinition(); 550 if (!DiagD) 551 DiagD = cast<VarDecl>(*I); 552 if (DiagD->isReferenced()) { 553 Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl) 554 << /*variable*/1 << DiagD->getDeclName(); 555 } else { 556 Diag(DiagD->getLocation(), diag::warn_unused_variable) 557 << DiagD->getDeclName(); 558 } 559 } 560 } 561 562 checkUndefinedInternals(*this); 563 } 564 565 // Check we've noticed that we're no longer parsing the initializer for every 566 // variable. If we miss cases, then at best we have a performance issue and 567 // at worst a rejects-valid bug. 568 assert(ParsingInitForAutoVars.empty() && 569 "Didn't unmark var as having its initializer parsed"); 570 571 TUScope = 0; 572} 573 574 575//===----------------------------------------------------------------------===// 576// Helper functions. 577//===----------------------------------------------------------------------===// 578 579DeclContext *Sema::getFunctionLevelDeclContext() { 580 DeclContext *DC = CurContext; 581 582 while (isa<BlockDecl>(DC) || isa<EnumDecl>(DC)) 583 DC = DC->getParent(); 584 585 return DC; 586} 587 588/// getCurFunctionDecl - If inside of a function body, this returns a pointer 589/// to the function decl for the function being parsed. If we're currently 590/// in a 'block', this returns the containing context. 591FunctionDecl *Sema::getCurFunctionDecl() { 592 DeclContext *DC = getFunctionLevelDeclContext(); 593 return dyn_cast<FunctionDecl>(DC); 594} 595 596ObjCMethodDecl *Sema::getCurMethodDecl() { 597 DeclContext *DC = getFunctionLevelDeclContext(); 598 return dyn_cast<ObjCMethodDecl>(DC); 599} 600 601NamedDecl *Sema::getCurFunctionOrMethodDecl() { 602 DeclContext *DC = getFunctionLevelDeclContext(); 603 if (isa<ObjCMethodDecl>(DC) || isa<FunctionDecl>(DC)) 604 return cast<NamedDecl>(DC); 605 return 0; 606} 607 608Sema::SemaDiagnosticBuilder::~SemaDiagnosticBuilder() { 609 if (!isActive()) 610 return; 611 612 if (llvm::Optional<TemplateDeductionInfo*> Info = SemaRef.isSFINAEContext()) { 613 switch (DiagnosticIDs::getDiagnosticSFINAEResponse(getDiagID())) { 614 case DiagnosticIDs::SFINAE_Report: 615 // Fall through; we'll report the diagnostic below. 616 break; 617 618 case DiagnosticIDs::SFINAE_AccessControl: 619 // Per C++ Core Issue 1170, access control is part of SFINAE. 620 // Additionally, the AccessCheckingSFINAE flag can be used to temporary 621 // make access control a part of SFINAE for the purposes of checking 622 // type traits. 623 if (!SemaRef.AccessCheckingSFINAE && 624 !SemaRef.getLangOptions().CPlusPlus0x) 625 break; 626 627 case DiagnosticIDs::SFINAE_SubstitutionFailure: 628 // Count this failure so that we know that template argument deduction 629 // has failed. 630 ++SemaRef.NumSFINAEErrors; 631 SemaRef.Diags.setLastDiagnosticIgnored(); 632 SemaRef.Diags.Clear(); 633 Clear(); 634 return; 635 636 case DiagnosticIDs::SFINAE_Suppress: 637 // Make a copy of this suppressed diagnostic and store it with the 638 // template-deduction information; 639 FlushCounts(); 640 DiagnosticInfo DiagInfo(&SemaRef.Diags); 641 642 if (*Info) 643 (*Info)->addSuppressedDiagnostic(DiagInfo.getLocation(), 644 PartialDiagnostic(DiagInfo, 645 SemaRef.Context.getDiagAllocator())); 646 647 // Suppress this diagnostic. 648 SemaRef.Diags.setLastDiagnosticIgnored(); 649 SemaRef.Diags.Clear(); 650 Clear(); 651 return; 652 } 653 } 654 655 // Emit the diagnostic. 656 if (!this->Emit()) 657 return; 658 659 // If this is not a note, and we're in a template instantiation 660 // that is different from the last template instantiation where 661 // we emitted an error, print a template instantiation 662 // backtrace. 663 if (!DiagnosticIDs::isBuiltinNote(DiagID) && 664 !SemaRef.ActiveTemplateInstantiations.empty() && 665 SemaRef.ActiveTemplateInstantiations.back() 666 != SemaRef.LastTemplateInstantiationErrorContext) { 667 SemaRef.PrintInstantiationStack(); 668 SemaRef.LastTemplateInstantiationErrorContext 669 = SemaRef.ActiveTemplateInstantiations.back(); 670 } 671} 672 673Sema::SemaDiagnosticBuilder Sema::Diag(SourceLocation Loc, unsigned DiagID) { 674 DiagnosticBuilder DB = Diags.Report(Loc, DiagID); 675 return SemaDiagnosticBuilder(DB, *this, DiagID); 676} 677 678Sema::SemaDiagnosticBuilder 679Sema::Diag(SourceLocation Loc, const PartialDiagnostic& PD) { 680 SemaDiagnosticBuilder Builder(Diag(Loc, PD.getDiagID())); 681 PD.Emit(Builder); 682 683 return Builder; 684} 685 686/// \brief Looks through the macro-expansion chain for the given 687/// location, looking for a macro expansion with the given name. 688/// If one is found, returns true and sets the location to that 689/// expansion loc. 690bool Sema::findMacroSpelling(SourceLocation &locref, StringRef name) { 691 SourceLocation loc = locref; 692 if (!loc.isMacroID()) return false; 693 694 // There's no good way right now to look at the intermediate 695 // expansions, so just jump to the expansion location. 696 loc = getSourceManager().getExpansionLoc(loc); 697 698 // If that's written with the name, stop here. 699 SmallVector<char, 16> buffer; 700 if (getPreprocessor().getSpelling(loc, buffer) == name) { 701 locref = loc; 702 return true; 703 } 704 return false; 705} 706 707/// \brief Determines the active Scope associated with the given declaration 708/// context. 709/// 710/// This routine maps a declaration context to the active Scope object that 711/// represents that declaration context in the parser. It is typically used 712/// from "scope-less" code (e.g., template instantiation, lazy creation of 713/// declarations) that injects a name for name-lookup purposes and, therefore, 714/// must update the Scope. 715/// 716/// \returns The scope corresponding to the given declaraion context, or NULL 717/// if no such scope is open. 718Scope *Sema::getScopeForContext(DeclContext *Ctx) { 719 720 if (!Ctx) 721 return 0; 722 723 Ctx = Ctx->getPrimaryContext(); 724 for (Scope *S = getCurScope(); S; S = S->getParent()) { 725 // Ignore scopes that cannot have declarations. This is important for 726 // out-of-line definitions of static class members. 727 if (S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) 728 if (DeclContext *Entity = static_cast<DeclContext *> (S->getEntity())) 729 if (Ctx == Entity->getPrimaryContext()) 730 return S; 731 } 732 733 return 0; 734} 735 736/// \brief Enter a new function scope 737void Sema::PushFunctionScope() { 738 if (FunctionScopes.size() == 1) { 739 // Use the "top" function scope rather than having to allocate 740 // memory for a new scope. 741 FunctionScopes.back()->Clear(); 742 FunctionScopes.push_back(FunctionScopes.back()); 743 return; 744 } 745 746 FunctionScopes.push_back(new FunctionScopeInfo(getDiagnostics())); 747} 748 749void Sema::PushBlockScope(Scope *BlockScope, BlockDecl *Block) { 750 FunctionScopes.push_back(new BlockScopeInfo(getDiagnostics(), 751 BlockScope, Block)); 752} 753 754void Sema::PopFunctionOrBlockScope(const AnalysisBasedWarnings::Policy *WP, 755 const Decl *D, const BlockExpr *blkExpr) { 756 FunctionScopeInfo *Scope = FunctionScopes.pop_back_val(); 757 assert(!FunctionScopes.empty() && "mismatched push/pop!"); 758 759 // Issue any analysis-based warnings. 760 if (WP && D) 761 AnalysisWarnings.IssueWarnings(*WP, Scope, D, blkExpr); 762 else { 763 for (SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator 764 i = Scope->PossiblyUnreachableDiags.begin(), 765 e = Scope->PossiblyUnreachableDiags.end(); 766 i != e; ++i) { 767 const sema::PossiblyUnreachableDiag &D = *i; 768 Diag(D.Loc, D.PD); 769 } 770 } 771 772 if (FunctionScopes.back() != Scope) { 773 delete Scope; 774 } 775} 776 777/// \brief Determine whether any errors occurred within this function/method/ 778/// block. 779bool Sema::hasAnyUnrecoverableErrorsInThisFunction() const { 780 return getCurFunction()->ErrorTrap.hasUnrecoverableErrorOccurred(); 781} 782 783BlockScopeInfo *Sema::getCurBlock() { 784 if (FunctionScopes.empty()) 785 return 0; 786 787 return dyn_cast<BlockScopeInfo>(FunctionScopes.back()); 788} 789 790// Pin this vtable to this file. 791ExternalSemaSource::~ExternalSemaSource() {} 792 793std::pair<ObjCMethodList, ObjCMethodList> 794ExternalSemaSource::ReadMethodPool(Selector Sel) { 795 return std::pair<ObjCMethodList, ObjCMethodList>(); 796} 797 798void ExternalSemaSource::ReadKnownNamespaces( 799 SmallVectorImpl<NamespaceDecl *> &Namespaces) { 800} 801 802void PrettyDeclStackTraceEntry::print(raw_ostream &OS) const { 803 SourceLocation Loc = this->Loc; 804 if (!Loc.isValid() && TheDecl) Loc = TheDecl->getLocation(); 805 if (Loc.isValid()) { 806 Loc.print(OS, S.getSourceManager()); 807 OS << ": "; 808 } 809 OS << Message; 810 811 if (TheDecl && isa<NamedDecl>(TheDecl)) { 812 std::string Name = cast<NamedDecl>(TheDecl)->getNameAsString(); 813 if (!Name.empty()) 814 OS << " '" << Name << '\''; 815 } 816 817 OS << '\n'; 818} 819 820/// \brief Figure out if an expression could be turned into a call. 821/// 822/// Use this when trying to recover from an error where the programmer may have 823/// written just the name of a function instead of actually calling it. 824/// 825/// \param E - The expression to examine. 826/// \param ZeroArgCallReturnTy - If the expression can be turned into a call 827/// with no arguments, this parameter is set to the type returned by such a 828/// call; otherwise, it is set to an empty QualType. 829/// \param NonTemplateOverloads - If the expression is an overloaded function 830/// name, this parameter is populated with the decls of the various overloads. 831bool Sema::isExprCallable(const Expr &E, QualType &ZeroArgCallReturnTy, 832 UnresolvedSetImpl &NonTemplateOverloads) { 833 ZeroArgCallReturnTy = QualType(); 834 NonTemplateOverloads.clear(); 835 if (const OverloadExpr *Overloads = dyn_cast<OverloadExpr>(&E)) { 836 for (OverloadExpr::decls_iterator it = Overloads->decls_begin(), 837 DeclsEnd = Overloads->decls_end(); it != DeclsEnd; ++it) { 838 // Our overload set may include TemplateDecls, which we'll ignore for our 839 // present purpose. 840 if (const FunctionDecl *OverloadDecl = dyn_cast<FunctionDecl>(*it)) { 841 NonTemplateOverloads.addDecl(*it); 842 if (OverloadDecl->getMinRequiredArguments() == 0) 843 ZeroArgCallReturnTy = OverloadDecl->getResultType(); 844 } 845 } 846 return true; 847 } 848 849 if (const DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(&E)) { 850 if (const FunctionDecl *Fun = dyn_cast<FunctionDecl>(DeclRef->getDecl())) { 851 if (Fun->getMinRequiredArguments() == 0) 852 ZeroArgCallReturnTy = Fun->getResultType(); 853 return true; 854 } 855 } 856 857 // We don't have an expression that's convenient to get a FunctionDecl from, 858 // but we can at least check if the type is "function of 0 arguments". 859 QualType ExprTy = E.getType(); 860 const FunctionType *FunTy = NULL; 861 QualType PointeeTy = ExprTy->getPointeeType(); 862 if (!PointeeTy.isNull()) 863 FunTy = PointeeTy->getAs<FunctionType>(); 864 if (!FunTy) 865 FunTy = ExprTy->getAs<FunctionType>(); 866 if (!FunTy && ExprTy == Context.BoundMemberTy) { 867 // Look for the bound-member type. If it's still overloaded, give up, 868 // although we probably should have fallen into the OverloadExpr case above 869 // if we actually have an overloaded bound member. 870 QualType BoundMemberTy = Expr::findBoundMemberType(&E); 871 if (!BoundMemberTy.isNull()) 872 FunTy = BoundMemberTy->castAs<FunctionType>(); 873 } 874 875 if (const FunctionProtoType *FPT = 876 dyn_cast_or_null<FunctionProtoType>(FunTy)) { 877 if (FPT->getNumArgs() == 0) 878 ZeroArgCallReturnTy = FunTy->getResultType(); 879 return true; 880 } 881 return false; 882} 883 884/// \brief Give notes for a set of overloads. 885/// 886/// A companion to isExprCallable. In cases when the name that the programmer 887/// wrote was an overloaded function, we may be able to make some guesses about 888/// plausible overloads based on their return types; such guesses can be handed 889/// off to this method to be emitted as notes. 890/// 891/// \param Overloads - The overloads to note. 892/// \param FinalNoteLoc - If we've suppressed printing some overloads due to 893/// -fshow-overloads=best, this is the location to attach to the note about too 894/// many candidates. Typically this will be the location of the original 895/// ill-formed expression. 896void Sema::NoteOverloads(const UnresolvedSetImpl &Overloads, 897 const SourceLocation FinalNoteLoc) { 898 int ShownOverloads = 0; 899 int SuppressedOverloads = 0; 900 for (UnresolvedSetImpl::iterator It = Overloads.begin(), 901 DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) { 902 // FIXME: Magic number for max shown overloads stolen from 903 // OverloadCandidateSet::NoteCandidates. 904 if (ShownOverloads >= 4 && 905 Diags.getShowOverloads() == Diagnostic::Ovl_Best) { 906 ++SuppressedOverloads; 907 continue; 908 } 909 Diag(cast<FunctionDecl>(*It)->getSourceRange().getBegin(), 910 diag::note_member_ref_possible_intended_overload); 911 ++ShownOverloads; 912 } 913 if (SuppressedOverloads) 914 Diag(FinalNoteLoc, diag::note_ovl_too_many_candidates) 915 << SuppressedOverloads; 916} 917