SemaLookup.cpp revision c259eacc7de93cef9aca8f01403c8c9d1c387688
1//===--------------------- SemaLookup.cpp - Name Lookup ------------------===// 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 name lookup for C, C++, Objective-C, and 11// Objective-C++. 12// 13//===----------------------------------------------------------------------===// 14#include "Sema.h" 15#include "Lookup.h" 16#include "clang/AST/ASTContext.h" 17#include "clang/AST/CXXInheritance.h" 18#include "clang/AST/Decl.h" 19#include "clang/AST/DeclCXX.h" 20#include "clang/AST/DeclObjC.h" 21#include "clang/AST/DeclTemplate.h" 22#include "clang/AST/Expr.h" 23#include "clang/AST/ExprCXX.h" 24#include "clang/Parse/DeclSpec.h" 25#include "clang/Basic/Builtins.h" 26#include "clang/Basic/LangOptions.h" 27#include "llvm/ADT/STLExtras.h" 28#include "llvm/ADT/SmallPtrSet.h" 29#include "llvm/Support/ErrorHandling.h" 30#include <list> 31#include <set> 32#include <vector> 33#include <iterator> 34#include <utility> 35#include <algorithm> 36 37using namespace clang; 38 39namespace { 40 class UnqualUsingEntry { 41 const DeclContext *Nominated; 42 const DeclContext *CommonAncestor; 43 44 public: 45 UnqualUsingEntry(const DeclContext *Nominated, 46 const DeclContext *CommonAncestor) 47 : Nominated(Nominated), CommonAncestor(CommonAncestor) { 48 } 49 50 const DeclContext *getCommonAncestor() const { 51 return CommonAncestor; 52 } 53 54 const DeclContext *getNominatedNamespace() const { 55 return Nominated; 56 } 57 58 // Sort by the pointer value of the common ancestor. 59 struct Comparator { 60 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) { 61 return L.getCommonAncestor() < R.getCommonAncestor(); 62 } 63 64 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) { 65 return E.getCommonAncestor() < DC; 66 } 67 68 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) { 69 return DC < E.getCommonAncestor(); 70 } 71 }; 72 }; 73 74 /// A collection of using directives, as used by C++ unqualified 75 /// lookup. 76 class UnqualUsingDirectiveSet { 77 typedef llvm::SmallVector<UnqualUsingEntry, 8> ListTy; 78 79 ListTy list; 80 llvm::SmallPtrSet<DeclContext*, 8> visited; 81 82 public: 83 UnqualUsingDirectiveSet() {} 84 85 void visitScopeChain(Scope *S, Scope *InnermostFileScope) { 86 // C++ [namespace.udir]p1: 87 // During unqualified name lookup, the names appear as if they 88 // were declared in the nearest enclosing namespace which contains 89 // both the using-directive and the nominated namespace. 90 DeclContext *InnermostFileDC 91 = static_cast<DeclContext*>(InnermostFileScope->getEntity()); 92 assert(InnermostFileDC && InnermostFileDC->isFileContext()); 93 94 for (; S; S = S->getParent()) { 95 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) { 96 DeclContext *EffectiveDC = (Ctx->isFileContext() ? Ctx : InnermostFileDC); 97 visit(Ctx, EffectiveDC); 98 } else { 99 Scope::udir_iterator I = S->using_directives_begin(), 100 End = S->using_directives_end(); 101 102 for (; I != End; ++I) 103 visit(I->getAs<UsingDirectiveDecl>(), InnermostFileDC); 104 } 105 } 106 } 107 108 // Visits a context and collect all of its using directives 109 // recursively. Treats all using directives as if they were 110 // declared in the context. 111 // 112 // A given context is only every visited once, so it is important 113 // that contexts be visited from the inside out in order to get 114 // the effective DCs right. 115 void visit(DeclContext *DC, DeclContext *EffectiveDC) { 116 if (!visited.insert(DC)) 117 return; 118 119 addUsingDirectives(DC, EffectiveDC); 120 } 121 122 // Visits a using directive and collects all of its using 123 // directives recursively. Treats all using directives as if they 124 // were declared in the effective DC. 125 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 126 DeclContext *NS = UD->getNominatedNamespace(); 127 if (!visited.insert(NS)) 128 return; 129 130 addUsingDirective(UD, EffectiveDC); 131 addUsingDirectives(NS, EffectiveDC); 132 } 133 134 // Adds all the using directives in a context (and those nominated 135 // by its using directives, transitively) as if they appeared in 136 // the given effective context. 137 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) { 138 llvm::SmallVector<DeclContext*,4> queue; 139 while (true) { 140 DeclContext::udir_iterator I, End; 141 for (llvm::tie(I, End) = DC->getUsingDirectives(); I != End; ++I) { 142 UsingDirectiveDecl *UD = *I; 143 DeclContext *NS = UD->getNominatedNamespace(); 144 if (visited.insert(NS)) { 145 addUsingDirective(UD, EffectiveDC); 146 queue.push_back(NS); 147 } 148 } 149 150 if (queue.empty()) 151 return; 152 153 DC = queue.back(); 154 queue.pop_back(); 155 } 156 } 157 158 // Add a using directive as if it had been declared in the given 159 // context. This helps implement C++ [namespace.udir]p3: 160 // The using-directive is transitive: if a scope contains a 161 // using-directive that nominates a second namespace that itself 162 // contains using-directives, the effect is as if the 163 // using-directives from the second namespace also appeared in 164 // the first. 165 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 166 // Find the common ancestor between the effective context and 167 // the nominated namespace. 168 DeclContext *Common = UD->getNominatedNamespace(); 169 while (!Common->Encloses(EffectiveDC)) 170 Common = Common->getParent(); 171 Common = Common->getPrimaryContext(); 172 173 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common)); 174 } 175 176 void done() { 177 std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator()); 178 } 179 180 typedef ListTy::iterator iterator; 181 typedef ListTy::const_iterator const_iterator; 182 183 iterator begin() { return list.begin(); } 184 iterator end() { return list.end(); } 185 const_iterator begin() const { return list.begin(); } 186 const_iterator end() const { return list.end(); } 187 188 std::pair<const_iterator,const_iterator> 189 getNamespacesFor(DeclContext *DC) const { 190 return std::equal_range(begin(), end(), DC->getPrimaryContext(), 191 UnqualUsingEntry::Comparator()); 192 } 193 }; 194} 195 196// Retrieve the set of identifier namespaces that correspond to a 197// specific kind of name lookup. 198static inline unsigned getIDNS(Sema::LookupNameKind NameKind, 199 bool CPlusPlus, 200 bool Redeclaration) { 201 unsigned IDNS = 0; 202 switch (NameKind) { 203 case Sema::LookupOrdinaryName: 204 case Sema::LookupRedeclarationWithLinkage: 205 IDNS = Decl::IDNS_Ordinary; 206 if (CPlusPlus) { 207 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace; 208 if (Redeclaration) IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend; 209 } 210 break; 211 212 case Sema::LookupOperatorName: 213 // Operator lookup is its own crazy thing; it is not the same 214 // as (e.g.) looking up an operator name for redeclaration. 215 assert(!Redeclaration && "cannot do redeclaration operator lookup"); 216 IDNS = Decl::IDNS_NonMemberOperator; 217 break; 218 219 case Sema::LookupTagName: 220 if (CPlusPlus) { 221 IDNS = Decl::IDNS_Type; 222 223 // When looking for a redeclaration of a tag name, we add: 224 // 1) TagFriend to find undeclared friend decls 225 // 2) Namespace because they can't "overload" with tag decls. 226 // 3) Tag because it includes class templates, which can't 227 // "overload" with tag decls. 228 if (Redeclaration) 229 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace; 230 } else { 231 IDNS = Decl::IDNS_Tag; 232 } 233 break; 234 235 case Sema::LookupMemberName: 236 IDNS = Decl::IDNS_Member; 237 if (CPlusPlus) 238 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary; 239 break; 240 241 case Sema::LookupNestedNameSpecifierName: 242 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace; 243 break; 244 245 case Sema::LookupNamespaceName: 246 IDNS = Decl::IDNS_Namespace; 247 break; 248 249 case Sema::LookupUsingDeclName: 250 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag 251 | Decl::IDNS_Member | Decl::IDNS_Using; 252 break; 253 254 case Sema::LookupObjCProtocolName: 255 IDNS = Decl::IDNS_ObjCProtocol; 256 break; 257 } 258 return IDNS; 259} 260 261void LookupResult::configure() { 262 IDNS = getIDNS(LookupKind, 263 SemaRef.getLangOptions().CPlusPlus, 264 isForRedeclaration()); 265 266 // If we're looking for one of the allocation or deallocation 267 // operators, make sure that the implicitly-declared new and delete 268 // operators can be found. 269 if (!isForRedeclaration()) { 270 switch (Name.getCXXOverloadedOperator()) { 271 case OO_New: 272 case OO_Delete: 273 case OO_Array_New: 274 case OO_Array_Delete: 275 SemaRef.DeclareGlobalNewDelete(); 276 break; 277 278 default: 279 break; 280 } 281 } 282} 283 284// Necessary because CXXBasePaths is not complete in Sema.h 285void LookupResult::deletePaths(CXXBasePaths *Paths) { 286 delete Paths; 287} 288 289/// Resolves the result kind of this lookup. 290void LookupResult::resolveKind() { 291 unsigned N = Decls.size(); 292 293 // Fast case: no possible ambiguity. 294 if (N == 0) { 295 assert(ResultKind == NotFound || ResultKind == NotFoundInCurrentInstantiation); 296 return; 297 } 298 299 // If there's a single decl, we need to examine it to decide what 300 // kind of lookup this is. 301 if (N == 1) { 302 NamedDecl *D = (*Decls.begin())->getUnderlyingDecl(); 303 if (isa<FunctionTemplateDecl>(D)) 304 ResultKind = FoundOverloaded; 305 else if (isa<UnresolvedUsingValueDecl>(D)) 306 ResultKind = FoundUnresolvedValue; 307 return; 308 } 309 310 // Don't do any extra resolution if we've already resolved as ambiguous. 311 if (ResultKind == Ambiguous) return; 312 313 llvm::SmallPtrSet<NamedDecl*, 16> Unique; 314 315 bool Ambiguous = false; 316 bool HasTag = false, HasFunction = false, HasNonFunction = false; 317 bool HasFunctionTemplate = false, HasUnresolved = false; 318 319 unsigned UniqueTagIndex = 0; 320 321 unsigned I = 0; 322 while (I < N) { 323 NamedDecl *D = Decls[I]->getUnderlyingDecl(); 324 D = cast<NamedDecl>(D->getCanonicalDecl()); 325 326 if (!Unique.insert(D)) { 327 // If it's not unique, pull something off the back (and 328 // continue at this index). 329 Decls[I] = Decls[--N]; 330 } else { 331 // Otherwise, do some decl type analysis and then continue. 332 333 if (isa<UnresolvedUsingValueDecl>(D)) { 334 HasUnresolved = true; 335 } else if (isa<TagDecl>(D)) { 336 if (HasTag) 337 Ambiguous = true; 338 UniqueTagIndex = I; 339 HasTag = true; 340 } else if (isa<FunctionTemplateDecl>(D)) { 341 HasFunction = true; 342 HasFunctionTemplate = true; 343 } else if (isa<FunctionDecl>(D)) { 344 HasFunction = true; 345 } else { 346 if (HasNonFunction) 347 Ambiguous = true; 348 HasNonFunction = true; 349 } 350 I++; 351 } 352 } 353 354 // C++ [basic.scope.hiding]p2: 355 // A class name or enumeration name can be hidden by the name of 356 // an object, function, or enumerator declared in the same 357 // scope. If a class or enumeration name and an object, function, 358 // or enumerator are declared in the same scope (in any order) 359 // with the same name, the class or enumeration name is hidden 360 // wherever the object, function, or enumerator name is visible. 361 // But it's still an error if there are distinct tag types found, 362 // even if they're not visible. (ref?) 363 if (HideTags && HasTag && !Ambiguous && 364 (HasFunction || HasNonFunction || HasUnresolved)) 365 Decls[UniqueTagIndex] = Decls[--N]; 366 367 Decls.set_size(N); 368 369 if (HasNonFunction && (HasFunction || HasUnresolved)) 370 Ambiguous = true; 371 372 if (Ambiguous) 373 setAmbiguous(LookupResult::AmbiguousReference); 374 else if (HasUnresolved) 375 ResultKind = LookupResult::FoundUnresolvedValue; 376 else if (N > 1 || HasFunctionTemplate) 377 ResultKind = LookupResult::FoundOverloaded; 378 else 379 ResultKind = LookupResult::Found; 380} 381 382void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) { 383 CXXBasePaths::const_paths_iterator I, E; 384 DeclContext::lookup_iterator DI, DE; 385 for (I = P.begin(), E = P.end(); I != E; ++I) 386 for (llvm::tie(DI,DE) = I->Decls; DI != DE; ++DI) 387 addDecl(*DI); 388} 389 390void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) { 391 Paths = new CXXBasePaths; 392 Paths->swap(P); 393 addDeclsFromBasePaths(*Paths); 394 resolveKind(); 395 setAmbiguous(AmbiguousBaseSubobjects); 396} 397 398void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) { 399 Paths = new CXXBasePaths; 400 Paths->swap(P); 401 addDeclsFromBasePaths(*Paths); 402 resolveKind(); 403 setAmbiguous(AmbiguousBaseSubobjectTypes); 404} 405 406void LookupResult::print(llvm::raw_ostream &Out) { 407 Out << Decls.size() << " result(s)"; 408 if (isAmbiguous()) Out << ", ambiguous"; 409 if (Paths) Out << ", base paths present"; 410 411 for (iterator I = begin(), E = end(); I != E; ++I) { 412 Out << "\n"; 413 (*I)->print(Out, 2); 414 } 415} 416 417/// \brief Lookup a builtin function, when name lookup would otherwise 418/// fail. 419static bool LookupBuiltin(Sema &S, LookupResult &R) { 420 Sema::LookupNameKind NameKind = R.getLookupKind(); 421 422 // If we didn't find a use of this identifier, and if the identifier 423 // corresponds to a compiler builtin, create the decl object for the builtin 424 // now, injecting it into translation unit scope, and return it. 425 if (NameKind == Sema::LookupOrdinaryName || 426 NameKind == Sema::LookupRedeclarationWithLinkage) { 427 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo(); 428 if (II) { 429 // If this is a builtin on this (or all) targets, create the decl. 430 if (unsigned BuiltinID = II->getBuiltinID()) { 431 // In C++, we don't have any predefined library functions like 432 // 'malloc'. Instead, we'll just error. 433 if (S.getLangOptions().CPlusPlus && 434 S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 435 return false; 436 437 NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 438 S.TUScope, R.isForRedeclaration(), 439 R.getNameLoc()); 440 if (D) 441 R.addDecl(D); 442 return (D != NULL); 443 } 444 } 445 } 446 447 return false; 448} 449 450// Adds all qualifying matches for a name within a decl context to the 451// given lookup result. Returns true if any matches were found. 452static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) { 453 bool Found = false; 454 455 DeclContext::lookup_const_iterator I, E; 456 for (llvm::tie(I, E) = DC->lookup(R.getLookupName()); I != E; ++I) { 457 NamedDecl *D = *I; 458 if (R.isAcceptableDecl(D)) { 459 R.addDecl(D); 460 Found = true; 461 } 462 } 463 464 if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R)) 465 return true; 466 467 if (R.getLookupName().getNameKind() 468 != DeclarationName::CXXConversionFunctionName || 469 R.getLookupName().getCXXNameType()->isDependentType() || 470 !isa<CXXRecordDecl>(DC)) 471 return Found; 472 473 // C++ [temp.mem]p6: 474 // A specialization of a conversion function template is not found by 475 // name lookup. Instead, any conversion function templates visible in the 476 // context of the use are considered. [...] 477 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC); 478 if (!Record->isDefinition()) 479 return Found; 480 481 const UnresolvedSetImpl *Unresolved = Record->getConversionFunctions(); 482 for (UnresolvedSetImpl::iterator U = Unresolved->begin(), 483 UEnd = Unresolved->end(); U != UEnd; ++U) { 484 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U); 485 if (!ConvTemplate) 486 continue; 487 488 // When we're performing lookup for the purposes of redeclaration, just 489 // add the conversion function template. When we deduce template 490 // arguments for specializations, we'll end up unifying the return 491 // type of the new declaration with the type of the function template. 492 if (R.isForRedeclaration()) { 493 R.addDecl(ConvTemplate); 494 Found = true; 495 continue; 496 } 497 498 // C++ [temp.mem]p6: 499 // [...] For each such operator, if argument deduction succeeds 500 // (14.9.2.3), the resulting specialization is used as if found by 501 // name lookup. 502 // 503 // When referencing a conversion function for any purpose other than 504 // a redeclaration (such that we'll be building an expression with the 505 // result), perform template argument deduction and place the 506 // specialization into the result set. We do this to avoid forcing all 507 // callers to perform special deduction for conversion functions. 508 Sema::TemplateDeductionInfo Info(R.getSema().Context, R.getNameLoc()); 509 FunctionDecl *Specialization = 0; 510 511 const FunctionProtoType *ConvProto 512 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>(); 513 assert(ConvProto && "Nonsensical conversion function template type"); 514 515 // Compute the type of the function that we would expect the conversion 516 // function to have, if it were to match the name given. 517 // FIXME: Calling convention! 518 FunctionType::ExtInfo ConvProtoInfo = ConvProto->getExtInfo(); 519 QualType ExpectedType 520 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(), 521 0, 0, ConvProto->isVariadic(), 522 ConvProto->getTypeQuals(), 523 false, false, 0, 0, 524 ConvProtoInfo.withCallingConv(CC_Default)); 525 526 // Perform template argument deduction against the type that we would 527 // expect the function to have. 528 if (R.getSema().DeduceTemplateArguments(ConvTemplate, 0, ExpectedType, 529 Specialization, Info) 530 == Sema::TDK_Success) { 531 R.addDecl(Specialization); 532 Found = true; 533 } 534 } 535 536 return Found; 537} 538 539// Performs C++ unqualified lookup into the given file context. 540static bool 541CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context, 542 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) { 543 544 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!"); 545 546 // Perform direct name lookup into the LookupCtx. 547 bool Found = LookupDirect(S, R, NS); 548 549 // Perform direct name lookup into the namespaces nominated by the 550 // using directives whose common ancestor is this namespace. 551 UnqualUsingDirectiveSet::const_iterator UI, UEnd; 552 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(NS); 553 554 for (; UI != UEnd; ++UI) 555 if (LookupDirect(S, R, UI->getNominatedNamespace())) 556 Found = true; 557 558 R.resolveKind(); 559 560 return Found; 561} 562 563static bool isNamespaceOrTranslationUnitScope(Scope *S) { 564 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) 565 return Ctx->isFileContext(); 566 return false; 567} 568 569// Find the next outer declaration context from this scope. This 570// routine actually returns the semantic outer context, which may 571// differ from the lexical context (encoded directly in the Scope 572// stack) when we are parsing a member of a class template. In this 573// case, the second element of the pair will be true, to indicate that 574// name lookup should continue searching in this semantic context when 575// it leaves the current template parameter scope. 576static std::pair<DeclContext *, bool> findOuterContext(Scope *S) { 577 DeclContext *DC = static_cast<DeclContext *>(S->getEntity()); 578 DeclContext *Lexical = 0; 579 for (Scope *OuterS = S->getParent(); OuterS; 580 OuterS = OuterS->getParent()) { 581 if (OuterS->getEntity()) { 582 Lexical = static_cast<DeclContext *>(OuterS->getEntity()); 583 break; 584 } 585 } 586 587 // C++ [temp.local]p8: 588 // In the definition of a member of a class template that appears 589 // outside of the namespace containing the class template 590 // definition, the name of a template-parameter hides the name of 591 // a member of this namespace. 592 // 593 // Example: 594 // 595 // namespace N { 596 // class C { }; 597 // 598 // template<class T> class B { 599 // void f(T); 600 // }; 601 // } 602 // 603 // template<class C> void N::B<C>::f(C) { 604 // C b; // C is the template parameter, not N::C 605 // } 606 // 607 // In this example, the lexical context we return is the 608 // TranslationUnit, while the semantic context is the namespace N. 609 if (!Lexical || !DC || !S->getParent() || 610 !S->getParent()->isTemplateParamScope()) 611 return std::make_pair(Lexical, false); 612 613 // Find the outermost template parameter scope. 614 // For the example, this is the scope for the template parameters of 615 // template<class C>. 616 Scope *OutermostTemplateScope = S->getParent(); 617 while (OutermostTemplateScope->getParent() && 618 OutermostTemplateScope->getParent()->isTemplateParamScope()) 619 OutermostTemplateScope = OutermostTemplateScope->getParent(); 620 621 // Find the namespace context in which the original scope occurs. In 622 // the example, this is namespace N. 623 DeclContext *Semantic = DC; 624 while (!Semantic->isFileContext()) 625 Semantic = Semantic->getParent(); 626 627 // Find the declaration context just outside of the template 628 // parameter scope. This is the context in which the template is 629 // being lexically declaration (a namespace context). In the 630 // example, this is the global scope. 631 if (Lexical->isFileContext() && !Lexical->Equals(Semantic) && 632 Lexical->Encloses(Semantic)) 633 return std::make_pair(Semantic, true); 634 635 return std::make_pair(Lexical, false); 636} 637 638bool Sema::CppLookupName(LookupResult &R, Scope *S) { 639 assert(getLangOptions().CPlusPlus && "Can perform only C++ lookup"); 640 641 DeclarationName Name = R.getLookupName(); 642 643 Scope *Initial = S; 644 IdentifierResolver::iterator 645 I = IdResolver.begin(Name), 646 IEnd = IdResolver.end(); 647 648 // First we lookup local scope. 649 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir] 650 // ...During unqualified name lookup (3.4.1), the names appear as if 651 // they were declared in the nearest enclosing namespace which contains 652 // both the using-directive and the nominated namespace. 653 // [Note: in this context, "contains" means "contains directly or 654 // indirectly". 655 // 656 // For example: 657 // namespace A { int i; } 658 // void foo() { 659 // int i; 660 // { 661 // using namespace A; 662 // ++i; // finds local 'i', A::i appears at global scope 663 // } 664 // } 665 // 666 DeclContext *OutsideOfTemplateParamDC = 0; 667 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) { 668 DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity()); 669 670 // Check whether the IdResolver has anything in this scope. 671 bool Found = false; 672 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) { 673 if (R.isAcceptableDecl(*I)) { 674 Found = true; 675 R.addDecl(*I); 676 } 677 } 678 if (Found) { 679 R.resolveKind(); 680 if (S->isClassScope()) 681 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx)) 682 R.setNamingClass(Record); 683 return true; 684 } 685 686 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC && 687 S->getParent() && !S->getParent()->isTemplateParamScope()) { 688 // We've just searched the last template parameter scope and 689 // found nothing, so look into the the contexts between the 690 // lexical and semantic declaration contexts returned by 691 // findOuterContext(). This implements the name lookup behavior 692 // of C++ [temp.local]p8. 693 Ctx = OutsideOfTemplateParamDC; 694 OutsideOfTemplateParamDC = 0; 695 } 696 697 if (Ctx) { 698 DeclContext *OuterCtx; 699 bool SearchAfterTemplateScope; 700 llvm::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S); 701 if (SearchAfterTemplateScope) 702 OutsideOfTemplateParamDC = OuterCtx; 703 704 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 705 // We do not directly look into transparent contexts, since 706 // those entities will be found in the nearest enclosing 707 // non-transparent context. 708 if (Ctx->isTransparentContext()) 709 continue; 710 711 // We do not look directly into function or method contexts, 712 // since all of the local variables and parameters of the 713 // function/method are present within the Scope. 714 if (Ctx->isFunctionOrMethod()) { 715 // If we have an Objective-C instance method, look for ivars 716 // in the corresponding interface. 717 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 718 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo()) 719 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) { 720 ObjCInterfaceDecl *ClassDeclared; 721 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable( 722 Name.getAsIdentifierInfo(), 723 ClassDeclared)) { 724 if (R.isAcceptableDecl(Ivar)) { 725 R.addDecl(Ivar); 726 R.resolveKind(); 727 return true; 728 } 729 } 730 } 731 } 732 733 continue; 734 } 735 736 // Perform qualified name lookup into this context. 737 // FIXME: In some cases, we know that every name that could be found by 738 // this qualified name lookup will also be on the identifier chain. For 739 // example, inside a class without any base classes, we never need to 740 // perform qualified lookup because all of the members are on top of the 741 // identifier chain. 742 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true)) 743 return true; 744 } 745 } 746 } 747 748 // Stop if we ran out of scopes. 749 // FIXME: This really, really shouldn't be happening. 750 if (!S) return false; 751 752 // Collect UsingDirectiveDecls in all scopes, and recursively all 753 // nominated namespaces by those using-directives. 754 // 755 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we 756 // don't build it for each lookup! 757 758 UnqualUsingDirectiveSet UDirs; 759 UDirs.visitScopeChain(Initial, S); 760 UDirs.done(); 761 762 // Lookup namespace scope, and global scope. 763 // Unqualified name lookup in C++ requires looking into scopes 764 // that aren't strictly lexical, and therefore we walk through the 765 // context as well as walking through the scopes. 766 767 for (; S; S = S->getParent()) { 768 // Check whether the IdResolver has anything in this scope. 769 bool Found = false; 770 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) { 771 if (R.isAcceptableDecl(*I)) { 772 // We found something. Look for anything else in our scope 773 // with this same name and in an acceptable identifier 774 // namespace, so that we can construct an overload set if we 775 // need to. 776 Found = true; 777 R.addDecl(*I); 778 } 779 } 780 781 if (Found && S->isTemplateParamScope()) { 782 R.resolveKind(); 783 return true; 784 } 785 786 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity()); 787 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC && 788 S->getParent() && !S->getParent()->isTemplateParamScope()) { 789 // We've just searched the last template parameter scope and 790 // found nothing, so look into the the contexts between the 791 // lexical and semantic declaration contexts returned by 792 // findOuterContext(). This implements the name lookup behavior 793 // of C++ [temp.local]p8. 794 Ctx = OutsideOfTemplateParamDC; 795 OutsideOfTemplateParamDC = 0; 796 } 797 798 if (Ctx) { 799 DeclContext *OuterCtx; 800 bool SearchAfterTemplateScope; 801 llvm::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S); 802 if (SearchAfterTemplateScope) 803 OutsideOfTemplateParamDC = OuterCtx; 804 805 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 806 // We do not directly look into transparent contexts, since 807 // those entities will be found in the nearest enclosing 808 // non-transparent context. 809 if (Ctx->isTransparentContext()) 810 continue; 811 812 // If we have a context, and it's not a context stashed in the 813 // template parameter scope for an out-of-line definition, also 814 // look into that context. 815 if (!(Found && S && S->isTemplateParamScope())) { 816 assert(Ctx->isFileContext() && 817 "We should have been looking only at file context here already."); 818 819 // Look into context considering using-directives. 820 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) 821 Found = true; 822 } 823 824 if (Found) { 825 R.resolveKind(); 826 return true; 827 } 828 829 if (R.isForRedeclaration() && !Ctx->isTransparentContext()) 830 return false; 831 } 832 } 833 834 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext()) 835 return false; 836 } 837 838 return !R.empty(); 839} 840 841/// @brief Perform unqualified name lookup starting from a given 842/// scope. 843/// 844/// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is 845/// used to find names within the current scope. For example, 'x' in 846/// @code 847/// int x; 848/// int f() { 849/// return x; // unqualified name look finds 'x' in the global scope 850/// } 851/// @endcode 852/// 853/// Different lookup criteria can find different names. For example, a 854/// particular scope can have both a struct and a function of the same 855/// name, and each can be found by certain lookup criteria. For more 856/// information about lookup criteria, see the documentation for the 857/// class LookupCriteria. 858/// 859/// @param S The scope from which unqualified name lookup will 860/// begin. If the lookup criteria permits, name lookup may also search 861/// in the parent scopes. 862/// 863/// @param Name The name of the entity that we are searching for. 864/// 865/// @param Loc If provided, the source location where we're performing 866/// name lookup. At present, this is only used to produce diagnostics when 867/// C library functions (like "malloc") are implicitly declared. 868/// 869/// @returns The result of name lookup, which includes zero or more 870/// declarations and possibly additional information used to diagnose 871/// ambiguities. 872bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) { 873 DeclarationName Name = R.getLookupName(); 874 if (!Name) return false; 875 876 LookupNameKind NameKind = R.getLookupKind(); 877 878 if (!getLangOptions().CPlusPlus) { 879 // Unqualified name lookup in C/Objective-C is purely lexical, so 880 // search in the declarations attached to the name. 881 882 if (NameKind == Sema::LookupRedeclarationWithLinkage) { 883 // Find the nearest non-transparent declaration scope. 884 while (!(S->getFlags() & Scope::DeclScope) || 885 (S->getEntity() && 886 static_cast<DeclContext *>(S->getEntity()) 887 ->isTransparentContext())) 888 S = S->getParent(); 889 } 890 891 unsigned IDNS = R.getIdentifierNamespace(); 892 893 // Scan up the scope chain looking for a decl that matches this 894 // identifier that is in the appropriate namespace. This search 895 // should not take long, as shadowing of names is uncommon, and 896 // deep shadowing is extremely uncommon. 897 bool LeftStartingScope = false; 898 899 for (IdentifierResolver::iterator I = IdResolver.begin(Name), 900 IEnd = IdResolver.end(); 901 I != IEnd; ++I) 902 if ((*I)->isInIdentifierNamespace(IDNS)) { 903 if (NameKind == LookupRedeclarationWithLinkage) { 904 // Determine whether this (or a previous) declaration is 905 // out-of-scope. 906 if (!LeftStartingScope && !S->isDeclScope(DeclPtrTy::make(*I))) 907 LeftStartingScope = true; 908 909 // If we found something outside of our starting scope that 910 // does not have linkage, skip it. 911 if (LeftStartingScope && !((*I)->hasLinkage())) 912 continue; 913 } 914 915 R.addDecl(*I); 916 917 if ((*I)->getAttr<OverloadableAttr>()) { 918 // If this declaration has the "overloadable" attribute, we 919 // might have a set of overloaded functions. 920 921 // Figure out what scope the identifier is in. 922 while (!(S->getFlags() & Scope::DeclScope) || 923 !S->isDeclScope(DeclPtrTy::make(*I))) 924 S = S->getParent(); 925 926 // Find the last declaration in this scope (with the same 927 // name, naturally). 928 IdentifierResolver::iterator LastI = I; 929 for (++LastI; LastI != IEnd; ++LastI) { 930 if (!S->isDeclScope(DeclPtrTy::make(*LastI))) 931 break; 932 R.addDecl(*LastI); 933 } 934 } 935 936 R.resolveKind(); 937 938 return true; 939 } 940 } else { 941 // Perform C++ unqualified name lookup. 942 if (CppLookupName(R, S)) 943 return true; 944 } 945 946 // If we didn't find a use of this identifier, and if the identifier 947 // corresponds to a compiler builtin, create the decl object for the builtin 948 // now, injecting it into translation unit scope, and return it. 949 if (AllowBuiltinCreation) 950 return LookupBuiltin(*this, R); 951 952 return false; 953} 954 955/// @brief Perform qualified name lookup in the namespaces nominated by 956/// using directives by the given context. 957/// 958/// C++98 [namespace.qual]p2: 959/// Given X::m (where X is a user-declared namespace), or given ::m 960/// (where X is the global namespace), let S be the set of all 961/// declarations of m in X and in the transitive closure of all 962/// namespaces nominated by using-directives in X and its used 963/// namespaces, except that using-directives are ignored in any 964/// namespace, including X, directly containing one or more 965/// declarations of m. No namespace is searched more than once in 966/// the lookup of a name. If S is the empty set, the program is 967/// ill-formed. Otherwise, if S has exactly one member, or if the 968/// context of the reference is a using-declaration 969/// (namespace.udecl), S is the required set of declarations of 970/// m. Otherwise if the use of m is not one that allows a unique 971/// declaration to be chosen from S, the program is ill-formed. 972/// C++98 [namespace.qual]p5: 973/// During the lookup of a qualified namespace member name, if the 974/// lookup finds more than one declaration of the member, and if one 975/// declaration introduces a class name or enumeration name and the 976/// other declarations either introduce the same object, the same 977/// enumerator or a set of functions, the non-type name hides the 978/// class or enumeration name if and only if the declarations are 979/// from the same namespace; otherwise (the declarations are from 980/// different namespaces), the program is ill-formed. 981static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R, 982 DeclContext *StartDC) { 983 assert(StartDC->isFileContext() && "start context is not a file context"); 984 985 DeclContext::udir_iterator I = StartDC->using_directives_begin(); 986 DeclContext::udir_iterator E = StartDC->using_directives_end(); 987 988 if (I == E) return false; 989 990 // We have at least added all these contexts to the queue. 991 llvm::DenseSet<DeclContext*> Visited; 992 Visited.insert(StartDC); 993 994 // We have not yet looked into these namespaces, much less added 995 // their "using-children" to the queue. 996 llvm::SmallVector<NamespaceDecl*, 8> Queue; 997 998 // We have already looked into the initial namespace; seed the queue 999 // with its using-children. 1000 for (; I != E; ++I) { 1001 NamespaceDecl *ND = (*I)->getNominatedNamespace()->getOriginalNamespace(); 1002 if (Visited.insert(ND).second) 1003 Queue.push_back(ND); 1004 } 1005 1006 // The easiest way to implement the restriction in [namespace.qual]p5 1007 // is to check whether any of the individual results found a tag 1008 // and, if so, to declare an ambiguity if the final result is not 1009 // a tag. 1010 bool FoundTag = false; 1011 bool FoundNonTag = false; 1012 1013 LookupResult LocalR(LookupResult::Temporary, R); 1014 1015 bool Found = false; 1016 while (!Queue.empty()) { 1017 NamespaceDecl *ND = Queue.back(); 1018 Queue.pop_back(); 1019 1020 // We go through some convolutions here to avoid copying results 1021 // between LookupResults. 1022 bool UseLocal = !R.empty(); 1023 LookupResult &DirectR = UseLocal ? LocalR : R; 1024 bool FoundDirect = LookupDirect(S, DirectR, ND); 1025 1026 if (FoundDirect) { 1027 // First do any local hiding. 1028 DirectR.resolveKind(); 1029 1030 // If the local result is a tag, remember that. 1031 if (DirectR.isSingleTagDecl()) 1032 FoundTag = true; 1033 else 1034 FoundNonTag = true; 1035 1036 // Append the local results to the total results if necessary. 1037 if (UseLocal) { 1038 R.addAllDecls(LocalR); 1039 LocalR.clear(); 1040 } 1041 } 1042 1043 // If we find names in this namespace, ignore its using directives. 1044 if (FoundDirect) { 1045 Found = true; 1046 continue; 1047 } 1048 1049 for (llvm::tie(I,E) = ND->getUsingDirectives(); I != E; ++I) { 1050 NamespaceDecl *Nom = (*I)->getNominatedNamespace(); 1051 if (Visited.insert(Nom).second) 1052 Queue.push_back(Nom); 1053 } 1054 } 1055 1056 if (Found) { 1057 if (FoundTag && FoundNonTag) 1058 R.setAmbiguousQualifiedTagHiding(); 1059 else 1060 R.resolveKind(); 1061 } 1062 1063 return Found; 1064} 1065 1066/// \brief Perform qualified name lookup into a given context. 1067/// 1068/// Qualified name lookup (C++ [basic.lookup.qual]) is used to find 1069/// names when the context of those names is explicit specified, e.g., 1070/// "std::vector" or "x->member", or as part of unqualified name lookup. 1071/// 1072/// Different lookup criteria can find different names. For example, a 1073/// particular scope can have both a struct and a function of the same 1074/// name, and each can be found by certain lookup criteria. For more 1075/// information about lookup criteria, see the documentation for the 1076/// class LookupCriteria. 1077/// 1078/// \param R captures both the lookup criteria and any lookup results found. 1079/// 1080/// \param LookupCtx The context in which qualified name lookup will 1081/// search. If the lookup criteria permits, name lookup may also search 1082/// in the parent contexts or (for C++ classes) base classes. 1083/// 1084/// \param InUnqualifiedLookup true if this is qualified name lookup that 1085/// occurs as part of unqualified name lookup. 1086/// 1087/// \returns true if lookup succeeded, false if it failed. 1088bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 1089 bool InUnqualifiedLookup) { 1090 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context"); 1091 1092 if (!R.getLookupName()) 1093 return false; 1094 1095 // Make sure that the declaration context is complete. 1096 assert((!isa<TagDecl>(LookupCtx) || 1097 LookupCtx->isDependentContext() || 1098 cast<TagDecl>(LookupCtx)->isDefinition() || 1099 Context.getTypeDeclType(cast<TagDecl>(LookupCtx))->getAs<TagType>() 1100 ->isBeingDefined()) && 1101 "Declaration context must already be complete!"); 1102 1103 // Perform qualified name lookup into the LookupCtx. 1104 if (LookupDirect(*this, R, LookupCtx)) { 1105 R.resolveKind(); 1106 if (isa<CXXRecordDecl>(LookupCtx)) 1107 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx)); 1108 return true; 1109 } 1110 1111 // Don't descend into implied contexts for redeclarations. 1112 // C++98 [namespace.qual]p6: 1113 // In a declaration for a namespace member in which the 1114 // declarator-id is a qualified-id, given that the qualified-id 1115 // for the namespace member has the form 1116 // nested-name-specifier unqualified-id 1117 // the unqualified-id shall name a member of the namespace 1118 // designated by the nested-name-specifier. 1119 // See also [class.mfct]p5 and [class.static.data]p2. 1120 if (R.isForRedeclaration()) 1121 return false; 1122 1123 // If this is a namespace, look it up in the implied namespaces. 1124 if (LookupCtx->isFileContext()) 1125 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx); 1126 1127 // If this isn't a C++ class, we aren't allowed to look into base 1128 // classes, we're done. 1129 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx); 1130 if (!LookupRec || !LookupRec->getDefinition()) 1131 return false; 1132 1133 // If we're performing qualified name lookup into a dependent class, 1134 // then we are actually looking into a current instantiation. If we have any 1135 // dependent base classes, then we either have to delay lookup until 1136 // template instantiation time (at which point all bases will be available) 1137 // or we have to fail. 1138 if (!InUnqualifiedLookup && LookupRec->isDependentContext() && 1139 LookupRec->hasAnyDependentBases()) { 1140 R.setNotFoundInCurrentInstantiation(); 1141 return false; 1142 } 1143 1144 // Perform lookup into our base classes. 1145 CXXBasePaths Paths; 1146 Paths.setOrigin(LookupRec); 1147 1148 // Look for this member in our base classes 1149 CXXRecordDecl::BaseMatchesCallback *BaseCallback = 0; 1150 switch (R.getLookupKind()) { 1151 case LookupOrdinaryName: 1152 case LookupMemberName: 1153 case LookupRedeclarationWithLinkage: 1154 BaseCallback = &CXXRecordDecl::FindOrdinaryMember; 1155 break; 1156 1157 case LookupTagName: 1158 BaseCallback = &CXXRecordDecl::FindTagMember; 1159 break; 1160 1161 case LookupUsingDeclName: 1162 // This lookup is for redeclarations only. 1163 1164 case LookupOperatorName: 1165 case LookupNamespaceName: 1166 case LookupObjCProtocolName: 1167 // These lookups will never find a member in a C++ class (or base class). 1168 return false; 1169 1170 case LookupNestedNameSpecifierName: 1171 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember; 1172 break; 1173 } 1174 1175 if (!LookupRec->lookupInBases(BaseCallback, 1176 R.getLookupName().getAsOpaquePtr(), Paths)) 1177 return false; 1178 1179 R.setNamingClass(LookupRec); 1180 1181 // C++ [class.member.lookup]p2: 1182 // [...] If the resulting set of declarations are not all from 1183 // sub-objects of the same type, or the set has a nonstatic member 1184 // and includes members from distinct sub-objects, there is an 1185 // ambiguity and the program is ill-formed. Otherwise that set is 1186 // the result of the lookup. 1187 // FIXME: support using declarations! 1188 QualType SubobjectType; 1189 int SubobjectNumber = 0; 1190 AccessSpecifier SubobjectAccess = AS_none; 1191 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); 1192 Path != PathEnd; ++Path) { 1193 const CXXBasePathElement &PathElement = Path->back(); 1194 1195 // Pick the best (i.e. most permissive i.e. numerically lowest) access 1196 // across all paths. 1197 SubobjectAccess = std::min(SubobjectAccess, Path->Access); 1198 1199 // Determine whether we're looking at a distinct sub-object or not. 1200 if (SubobjectType.isNull()) { 1201 // This is the first subobject we've looked at. Record its type. 1202 SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); 1203 SubobjectNumber = PathElement.SubobjectNumber; 1204 } else if (SubobjectType 1205 != Context.getCanonicalType(PathElement.Base->getType())) { 1206 // We found members of the given name in two subobjects of 1207 // different types. This lookup is ambiguous. 1208 R.setAmbiguousBaseSubobjectTypes(Paths); 1209 return true; 1210 } else if (SubobjectNumber != PathElement.SubobjectNumber) { 1211 // We have a different subobject of the same type. 1212 1213 // C++ [class.member.lookup]p5: 1214 // A static member, a nested type or an enumerator defined in 1215 // a base class T can unambiguously be found even if an object 1216 // has more than one base class subobject of type T. 1217 Decl *FirstDecl = *Path->Decls.first; 1218 if (isa<VarDecl>(FirstDecl) || 1219 isa<TypeDecl>(FirstDecl) || 1220 isa<EnumConstantDecl>(FirstDecl)) 1221 continue; 1222 1223 if (isa<CXXMethodDecl>(FirstDecl)) { 1224 // Determine whether all of the methods are static. 1225 bool AllMethodsAreStatic = true; 1226 for (DeclContext::lookup_iterator Func = Path->Decls.first; 1227 Func != Path->Decls.second; ++Func) { 1228 if (!isa<CXXMethodDecl>(*Func)) { 1229 assert(isa<TagDecl>(*Func) && "Non-function must be a tag decl"); 1230 break; 1231 } 1232 1233 if (!cast<CXXMethodDecl>(*Func)->isStatic()) { 1234 AllMethodsAreStatic = false; 1235 break; 1236 } 1237 } 1238 1239 if (AllMethodsAreStatic) 1240 continue; 1241 } 1242 1243 // We have found a nonstatic member name in multiple, distinct 1244 // subobjects. Name lookup is ambiguous. 1245 R.setAmbiguousBaseSubobjects(Paths); 1246 return true; 1247 } 1248 } 1249 1250 // Lookup in a base class succeeded; return these results. 1251 1252 DeclContext::lookup_iterator I, E; 1253 for (llvm::tie(I,E) = Paths.front().Decls; I != E; ++I) { 1254 NamedDecl *D = *I; 1255 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess, 1256 D->getAccess()); 1257 R.addDecl(D, AS); 1258 } 1259 R.resolveKind(); 1260 return true; 1261} 1262 1263/// @brief Performs name lookup for a name that was parsed in the 1264/// source code, and may contain a C++ scope specifier. 1265/// 1266/// This routine is a convenience routine meant to be called from 1267/// contexts that receive a name and an optional C++ scope specifier 1268/// (e.g., "N::M::x"). It will then perform either qualified or 1269/// unqualified name lookup (with LookupQualifiedName or LookupName, 1270/// respectively) on the given name and return those results. 1271/// 1272/// @param S The scope from which unqualified name lookup will 1273/// begin. 1274/// 1275/// @param SS An optional C++ scope-specifier, e.g., "::N::M". 1276/// 1277/// @param Name The name of the entity that name lookup will 1278/// search for. 1279/// 1280/// @param Loc If provided, the source location where we're performing 1281/// name lookup. At present, this is only used to produce diagnostics when 1282/// C library functions (like "malloc") are implicitly declared. 1283/// 1284/// @param EnteringContext Indicates whether we are going to enter the 1285/// context of the scope-specifier SS (if present). 1286/// 1287/// @returns True if any decls were found (but possibly ambiguous) 1288bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS, 1289 bool AllowBuiltinCreation, bool EnteringContext) { 1290 if (SS && SS->isInvalid()) { 1291 // When the scope specifier is invalid, don't even look for 1292 // anything. 1293 return false; 1294 } 1295 1296 if (SS && SS->isSet()) { 1297 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { 1298 // We have resolved the scope specifier to a particular declaration 1299 // contex, and will perform name lookup in that context. 1300 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC)) 1301 return false; 1302 1303 R.setContextRange(SS->getRange()); 1304 1305 return LookupQualifiedName(R, DC); 1306 } 1307 1308 // We could not resolve the scope specified to a specific declaration 1309 // context, which means that SS refers to an unknown specialization. 1310 // Name lookup can't find anything in this case. 1311 return false; 1312 } 1313 1314 // Perform unqualified name lookup starting in the given scope. 1315 return LookupName(R, S, AllowBuiltinCreation); 1316} 1317 1318 1319/// @brief Produce a diagnostic describing the ambiguity that resulted 1320/// from name lookup. 1321/// 1322/// @param Result The ambiguous name lookup result. 1323/// 1324/// @param Name The name of the entity that name lookup was 1325/// searching for. 1326/// 1327/// @param NameLoc The location of the name within the source code. 1328/// 1329/// @param LookupRange A source range that provides more 1330/// source-location information concerning the lookup itself. For 1331/// example, this range might highlight a nested-name-specifier that 1332/// precedes the name. 1333/// 1334/// @returns true 1335bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result) { 1336 assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); 1337 1338 DeclarationName Name = Result.getLookupName(); 1339 SourceLocation NameLoc = Result.getNameLoc(); 1340 SourceRange LookupRange = Result.getContextRange(); 1341 1342 switch (Result.getAmbiguityKind()) { 1343 case LookupResult::AmbiguousBaseSubobjects: { 1344 CXXBasePaths *Paths = Result.getBasePaths(); 1345 QualType SubobjectType = Paths->front().back().Base->getType(); 1346 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) 1347 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) 1348 << LookupRange; 1349 1350 DeclContext::lookup_iterator Found = Paths->front().Decls.first; 1351 while (isa<CXXMethodDecl>(*Found) && 1352 cast<CXXMethodDecl>(*Found)->isStatic()) 1353 ++Found; 1354 1355 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); 1356 1357 return true; 1358 } 1359 1360 case LookupResult::AmbiguousBaseSubobjectTypes: { 1361 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) 1362 << Name << LookupRange; 1363 1364 CXXBasePaths *Paths = Result.getBasePaths(); 1365 std::set<Decl *> DeclsPrinted; 1366 for (CXXBasePaths::paths_iterator Path = Paths->begin(), 1367 PathEnd = Paths->end(); 1368 Path != PathEnd; ++Path) { 1369 Decl *D = *Path->Decls.first; 1370 if (DeclsPrinted.insert(D).second) 1371 Diag(D->getLocation(), diag::note_ambiguous_member_found); 1372 } 1373 1374 return true; 1375 } 1376 1377 case LookupResult::AmbiguousTagHiding: { 1378 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange; 1379 1380 llvm::SmallPtrSet<NamedDecl*,8> TagDecls; 1381 1382 LookupResult::iterator DI, DE = Result.end(); 1383 for (DI = Result.begin(); DI != DE; ++DI) 1384 if (TagDecl *TD = dyn_cast<TagDecl>(*DI)) { 1385 TagDecls.insert(TD); 1386 Diag(TD->getLocation(), diag::note_hidden_tag); 1387 } 1388 1389 for (DI = Result.begin(); DI != DE; ++DI) 1390 if (!isa<TagDecl>(*DI)) 1391 Diag((*DI)->getLocation(), diag::note_hiding_object); 1392 1393 // For recovery purposes, go ahead and implement the hiding. 1394 LookupResult::Filter F = Result.makeFilter(); 1395 while (F.hasNext()) { 1396 if (TagDecls.count(F.next())) 1397 F.erase(); 1398 } 1399 F.done(); 1400 1401 return true; 1402 } 1403 1404 case LookupResult::AmbiguousReference: { 1405 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; 1406 1407 LookupResult::iterator DI = Result.begin(), DE = Result.end(); 1408 for (; DI != DE; ++DI) 1409 Diag((*DI)->getLocation(), diag::note_ambiguous_candidate) << *DI; 1410 1411 return true; 1412 } 1413 } 1414 1415 llvm_unreachable("unknown ambiguity kind"); 1416 return true; 1417} 1418 1419namespace { 1420 struct AssociatedLookup { 1421 AssociatedLookup(Sema &S, 1422 Sema::AssociatedNamespaceSet &Namespaces, 1423 Sema::AssociatedClassSet &Classes) 1424 : S(S), Namespaces(Namespaces), Classes(Classes) { 1425 } 1426 1427 Sema &S; 1428 Sema::AssociatedNamespaceSet &Namespaces; 1429 Sema::AssociatedClassSet &Classes; 1430 }; 1431} 1432 1433static void 1434addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T); 1435 1436static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces, 1437 DeclContext *Ctx) { 1438 // Add the associated namespace for this class. 1439 1440 // We don't use DeclContext::getEnclosingNamespaceContext() as this may 1441 // be a locally scoped record. 1442 1443 while (Ctx->isRecord() || Ctx->isTransparentContext()) 1444 Ctx = Ctx->getParent(); 1445 1446 if (Ctx->isFileContext()) 1447 Namespaces.insert(Ctx->getPrimaryContext()); 1448} 1449 1450// \brief Add the associated classes and namespaces for argument-dependent 1451// lookup that involves a template argument (C++ [basic.lookup.koenig]p2). 1452static void 1453addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 1454 const TemplateArgument &Arg) { 1455 // C++ [basic.lookup.koenig]p2, last bullet: 1456 // -- [...] ; 1457 switch (Arg.getKind()) { 1458 case TemplateArgument::Null: 1459 break; 1460 1461 case TemplateArgument::Type: 1462 // [...] the namespaces and classes associated with the types of the 1463 // template arguments provided for template type parameters (excluding 1464 // template template parameters) 1465 addAssociatedClassesAndNamespaces(Result, Arg.getAsType()); 1466 break; 1467 1468 case TemplateArgument::Template: { 1469 // [...] the namespaces in which any template template arguments are 1470 // defined; and the classes in which any member templates used as 1471 // template template arguments are defined. 1472 TemplateName Template = Arg.getAsTemplate(); 1473 if (ClassTemplateDecl *ClassTemplate 1474 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) { 1475 DeclContext *Ctx = ClassTemplate->getDeclContext(); 1476 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1477 Result.Classes.insert(EnclosingClass); 1478 // Add the associated namespace for this class. 1479 CollectEnclosingNamespace(Result.Namespaces, Ctx); 1480 } 1481 break; 1482 } 1483 1484 case TemplateArgument::Declaration: 1485 case TemplateArgument::Integral: 1486 case TemplateArgument::Expression: 1487 // [Note: non-type template arguments do not contribute to the set of 1488 // associated namespaces. ] 1489 break; 1490 1491 case TemplateArgument::Pack: 1492 for (TemplateArgument::pack_iterator P = Arg.pack_begin(), 1493 PEnd = Arg.pack_end(); 1494 P != PEnd; ++P) 1495 addAssociatedClassesAndNamespaces(Result, *P); 1496 break; 1497 } 1498} 1499 1500// \brief Add the associated classes and namespaces for 1501// argument-dependent lookup with an argument of class type 1502// (C++ [basic.lookup.koenig]p2). 1503static void 1504addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 1505 CXXRecordDecl *Class) { 1506 1507 // Just silently ignore anything whose name is __va_list_tag. 1508 if (Class->getDeclName() == Result.S.VAListTagName) 1509 return; 1510 1511 // C++ [basic.lookup.koenig]p2: 1512 // [...] 1513 // -- If T is a class type (including unions), its associated 1514 // classes are: the class itself; the class of which it is a 1515 // member, if any; and its direct and indirect base 1516 // classes. Its associated namespaces are the namespaces in 1517 // which its associated classes are defined. 1518 1519 // Add the class of which it is a member, if any. 1520 DeclContext *Ctx = Class->getDeclContext(); 1521 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1522 Result.Classes.insert(EnclosingClass); 1523 // Add the associated namespace for this class. 1524 CollectEnclosingNamespace(Result.Namespaces, Ctx); 1525 1526 // Add the class itself. If we've already seen this class, we don't 1527 // need to visit base classes. 1528 if (!Result.Classes.insert(Class)) 1529 return; 1530 1531 // -- If T is a template-id, its associated namespaces and classes are 1532 // the namespace in which the template is defined; for member 1533 // templates, the member template’s class; the namespaces and classes 1534 // associated with the types of the template arguments provided for 1535 // template type parameters (excluding template template parameters); the 1536 // namespaces in which any template template arguments are defined; and 1537 // the classes in which any member templates used as template template 1538 // arguments are defined. [Note: non-type template arguments do not 1539 // contribute to the set of associated namespaces. ] 1540 if (ClassTemplateSpecializationDecl *Spec 1541 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) { 1542 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); 1543 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1544 Result.Classes.insert(EnclosingClass); 1545 // Add the associated namespace for this class. 1546 CollectEnclosingNamespace(Result.Namespaces, Ctx); 1547 1548 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); 1549 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 1550 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]); 1551 } 1552 1553 // Only recurse into base classes for complete types. 1554 if (!Class->hasDefinition()) { 1555 // FIXME: we might need to instantiate templates here 1556 return; 1557 } 1558 1559 // Add direct and indirect base classes along with their associated 1560 // namespaces. 1561 llvm::SmallVector<CXXRecordDecl *, 32> Bases; 1562 Bases.push_back(Class); 1563 while (!Bases.empty()) { 1564 // Pop this class off the stack. 1565 Class = Bases.back(); 1566 Bases.pop_back(); 1567 1568 // Visit the base classes. 1569 for (CXXRecordDecl::base_class_iterator Base = Class->bases_begin(), 1570 BaseEnd = Class->bases_end(); 1571 Base != BaseEnd; ++Base) { 1572 const RecordType *BaseType = Base->getType()->getAs<RecordType>(); 1573 // In dependent contexts, we do ADL twice, and the first time around, 1574 // the base type might be a dependent TemplateSpecializationType, or a 1575 // TemplateTypeParmType. If that happens, simply ignore it. 1576 // FIXME: If we want to support export, we probably need to add the 1577 // namespace of the template in a TemplateSpecializationType, or even 1578 // the classes and namespaces of known non-dependent arguments. 1579 if (!BaseType) 1580 continue; 1581 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 1582 if (Result.Classes.insert(BaseDecl)) { 1583 // Find the associated namespace for this base class. 1584 DeclContext *BaseCtx = BaseDecl->getDeclContext(); 1585 CollectEnclosingNamespace(Result.Namespaces, BaseCtx); 1586 1587 // Make sure we visit the bases of this base class. 1588 if (BaseDecl->bases_begin() != BaseDecl->bases_end()) 1589 Bases.push_back(BaseDecl); 1590 } 1591 } 1592 } 1593} 1594 1595// \brief Add the associated classes and namespaces for 1596// argument-dependent lookup with an argument of type T 1597// (C++ [basic.lookup.koenig]p2). 1598static void 1599addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) { 1600 // C++ [basic.lookup.koenig]p2: 1601 // 1602 // For each argument type T in the function call, there is a set 1603 // of zero or more associated namespaces and a set of zero or more 1604 // associated classes to be considered. The sets of namespaces and 1605 // classes is determined entirely by the types of the function 1606 // arguments (and the namespace of any template template 1607 // argument). Typedef names and using-declarations used to specify 1608 // the types do not contribute to this set. The sets of namespaces 1609 // and classes are determined in the following way: 1610 1611 llvm::SmallVector<const Type *, 16> Queue; 1612 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr(); 1613 1614 while (true) { 1615 switch (T->getTypeClass()) { 1616 1617#define TYPE(Class, Base) 1618#define DEPENDENT_TYPE(Class, Base) case Type::Class: 1619#define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 1620#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class: 1621#define ABSTRACT_TYPE(Class, Base) 1622#include "clang/AST/TypeNodes.def" 1623 // T is canonical. We can also ignore dependent types because 1624 // we don't need to do ADL at the definition point, but if we 1625 // wanted to implement template export (or if we find some other 1626 // use for associated classes and namespaces...) this would be 1627 // wrong. 1628 break; 1629 1630 // -- If T is a pointer to U or an array of U, its associated 1631 // namespaces and classes are those associated with U. 1632 case Type::Pointer: 1633 T = cast<PointerType>(T)->getPointeeType().getTypePtr(); 1634 continue; 1635 case Type::ConstantArray: 1636 case Type::IncompleteArray: 1637 case Type::VariableArray: 1638 T = cast<ArrayType>(T)->getElementType().getTypePtr(); 1639 continue; 1640 1641 // -- If T is a fundamental type, its associated sets of 1642 // namespaces and classes are both empty. 1643 case Type::Builtin: 1644 break; 1645 1646 // -- If T is a class type (including unions), its associated 1647 // classes are: the class itself; the class of which it is a 1648 // member, if any; and its direct and indirect base 1649 // classes. Its associated namespaces are the namespaces in 1650 // which its associated classes are defined. 1651 case Type::Record: { 1652 CXXRecordDecl *Class 1653 = cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl()); 1654 addAssociatedClassesAndNamespaces(Result, Class); 1655 break; 1656 } 1657 1658 // -- If T is an enumeration type, its associated namespace is 1659 // the namespace in which it is defined. If it is class 1660 // member, its associated class is the member’s class; else 1661 // it has no associated class. 1662 case Type::Enum: { 1663 EnumDecl *Enum = cast<EnumType>(T)->getDecl(); 1664 1665 DeclContext *Ctx = Enum->getDeclContext(); 1666 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1667 Result.Classes.insert(EnclosingClass); 1668 1669 // Add the associated namespace for this class. 1670 CollectEnclosingNamespace(Result.Namespaces, Ctx); 1671 1672 break; 1673 } 1674 1675 // -- If T is a function type, its associated namespaces and 1676 // classes are those associated with the function parameter 1677 // types and those associated with the return type. 1678 case Type::FunctionProto: { 1679 const FunctionProtoType *Proto = cast<FunctionProtoType>(T); 1680 for (FunctionProtoType::arg_type_iterator Arg = Proto->arg_type_begin(), 1681 ArgEnd = Proto->arg_type_end(); 1682 Arg != ArgEnd; ++Arg) 1683 Queue.push_back(Arg->getTypePtr()); 1684 // fallthrough 1685 } 1686 case Type::FunctionNoProto: { 1687 const FunctionType *FnType = cast<FunctionType>(T); 1688 T = FnType->getResultType().getTypePtr(); 1689 continue; 1690 } 1691 1692 // -- If T is a pointer to a member function of a class X, its 1693 // associated namespaces and classes are those associated 1694 // with the function parameter types and return type, 1695 // together with those associated with X. 1696 // 1697 // -- If T is a pointer to a data member of class X, its 1698 // associated namespaces and classes are those associated 1699 // with the member type together with those associated with 1700 // X. 1701 case Type::MemberPointer: { 1702 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T); 1703 1704 // Queue up the class type into which this points. 1705 Queue.push_back(MemberPtr->getClass()); 1706 1707 // And directly continue with the pointee type. 1708 T = MemberPtr->getPointeeType().getTypePtr(); 1709 continue; 1710 } 1711 1712 // As an extension, treat this like a normal pointer. 1713 case Type::BlockPointer: 1714 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr(); 1715 continue; 1716 1717 // References aren't covered by the standard, but that's such an 1718 // obvious defect that we cover them anyway. 1719 case Type::LValueReference: 1720 case Type::RValueReference: 1721 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr(); 1722 continue; 1723 1724 // These are fundamental types. 1725 case Type::Vector: 1726 case Type::ExtVector: 1727 case Type::Complex: 1728 break; 1729 1730 // These are ignored by ADL. 1731 case Type::ObjCObject: 1732 case Type::ObjCInterface: 1733 case Type::ObjCObjectPointer: 1734 break; 1735 } 1736 1737 if (Queue.empty()) break; 1738 T = Queue.back(); 1739 Queue.pop_back(); 1740 } 1741} 1742 1743/// \brief Find the associated classes and namespaces for 1744/// argument-dependent lookup for a call with the given set of 1745/// arguments. 1746/// 1747/// This routine computes the sets of associated classes and associated 1748/// namespaces searched by argument-dependent lookup 1749/// (C++ [basic.lookup.argdep]) for a given set of arguments. 1750void 1751Sema::FindAssociatedClassesAndNamespaces(Expr **Args, unsigned NumArgs, 1752 AssociatedNamespaceSet &AssociatedNamespaces, 1753 AssociatedClassSet &AssociatedClasses) { 1754 AssociatedNamespaces.clear(); 1755 AssociatedClasses.clear(); 1756 1757 AssociatedLookup Result(*this, AssociatedNamespaces, AssociatedClasses); 1758 1759 // C++ [basic.lookup.koenig]p2: 1760 // For each argument type T in the function call, there is a set 1761 // of zero or more associated namespaces and a set of zero or more 1762 // associated classes to be considered. The sets of namespaces and 1763 // classes is determined entirely by the types of the function 1764 // arguments (and the namespace of any template template 1765 // argument). 1766 for (unsigned ArgIdx = 0; ArgIdx != NumArgs; ++ArgIdx) { 1767 Expr *Arg = Args[ArgIdx]; 1768 1769 if (Arg->getType() != Context.OverloadTy) { 1770 addAssociatedClassesAndNamespaces(Result, Arg->getType()); 1771 continue; 1772 } 1773 1774 // [...] In addition, if the argument is the name or address of a 1775 // set of overloaded functions and/or function templates, its 1776 // associated classes and namespaces are the union of those 1777 // associated with each of the members of the set: the namespace 1778 // in which the function or function template is defined and the 1779 // classes and namespaces associated with its (non-dependent) 1780 // parameter types and return type. 1781 Arg = Arg->IgnoreParens(); 1782 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg)) 1783 if (unaryOp->getOpcode() == UnaryOperator::AddrOf) 1784 Arg = unaryOp->getSubExpr(); 1785 1786 UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg); 1787 if (!ULE) continue; 1788 1789 for (UnresolvedSetIterator I = ULE->decls_begin(), E = ULE->decls_end(); 1790 I != E; ++I) { 1791 // Look through any using declarations to find the underlying function. 1792 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 1793 1794 FunctionDecl *FDecl = dyn_cast<FunctionDecl>(Fn); 1795 if (!FDecl) 1796 FDecl = cast<FunctionTemplateDecl>(Fn)->getTemplatedDecl(); 1797 1798 // Add the classes and namespaces associated with the parameter 1799 // types and return type of this function. 1800 addAssociatedClassesAndNamespaces(Result, FDecl->getType()); 1801 } 1802 } 1803} 1804 1805/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is 1806/// an acceptable non-member overloaded operator for a call whose 1807/// arguments have types T1 (and, if non-empty, T2). This routine 1808/// implements the check in C++ [over.match.oper]p3b2 concerning 1809/// enumeration types. 1810static bool 1811IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn, 1812 QualType T1, QualType T2, 1813 ASTContext &Context) { 1814 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType())) 1815 return true; 1816 1817 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType())) 1818 return true; 1819 1820 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>(); 1821 if (Proto->getNumArgs() < 1) 1822 return false; 1823 1824 if (T1->isEnumeralType()) { 1825 QualType ArgType = Proto->getArgType(0).getNonReferenceType(); 1826 if (Context.hasSameUnqualifiedType(T1, ArgType)) 1827 return true; 1828 } 1829 1830 if (Proto->getNumArgs() < 2) 1831 return false; 1832 1833 if (!T2.isNull() && T2->isEnumeralType()) { 1834 QualType ArgType = Proto->getArgType(1).getNonReferenceType(); 1835 if (Context.hasSameUnqualifiedType(T2, ArgType)) 1836 return true; 1837 } 1838 1839 return false; 1840} 1841 1842NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name, 1843 SourceLocation Loc, 1844 LookupNameKind NameKind, 1845 RedeclarationKind Redecl) { 1846 LookupResult R(*this, Name, Loc, NameKind, Redecl); 1847 LookupName(R, S); 1848 return R.getAsSingle<NamedDecl>(); 1849} 1850 1851/// \brief Find the protocol with the given name, if any. 1852ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II, 1853 SourceLocation IdLoc) { 1854 Decl *D = LookupSingleName(TUScope, II, IdLoc, 1855 LookupObjCProtocolName); 1856 return cast_or_null<ObjCProtocolDecl>(D); 1857} 1858 1859void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, 1860 QualType T1, QualType T2, 1861 UnresolvedSetImpl &Functions) { 1862 // C++ [over.match.oper]p3: 1863 // -- The set of non-member candidates is the result of the 1864 // unqualified lookup of operator@ in the context of the 1865 // expression according to the usual rules for name lookup in 1866 // unqualified function calls (3.4.2) except that all member 1867 // functions are ignored. However, if no operand has a class 1868 // type, only those non-member functions in the lookup set 1869 // that have a first parameter of type T1 or "reference to 1870 // (possibly cv-qualified) T1", when T1 is an enumeration 1871 // type, or (if there is a right operand) a second parameter 1872 // of type T2 or "reference to (possibly cv-qualified) T2", 1873 // when T2 is an enumeration type, are candidate functions. 1874 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 1875 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName); 1876 LookupName(Operators, S); 1877 1878 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); 1879 1880 if (Operators.empty()) 1881 return; 1882 1883 for (LookupResult::iterator Op = Operators.begin(), OpEnd = Operators.end(); 1884 Op != OpEnd; ++Op) { 1885 NamedDecl *Found = (*Op)->getUnderlyingDecl(); 1886 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Found)) { 1887 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context)) 1888 Functions.addDecl(*Op, Op.getAccess()); // FIXME: canonical FD 1889 } else if (FunctionTemplateDecl *FunTmpl 1890 = dyn_cast<FunctionTemplateDecl>(Found)) { 1891 // FIXME: friend operators? 1892 // FIXME: do we need to check IsAcceptableNonMemberOperatorCandidate, 1893 // later? 1894 if (!FunTmpl->getDeclContext()->isRecord()) 1895 Functions.addDecl(*Op, Op.getAccess()); 1896 } 1897 } 1898} 1899 1900/// \brief Look for the destructor of the given class. 1901/// 1902/// During semantic analysis, this routine should be used in lieu of 1903/// CXXRecordDecl::getDestructor(). 1904/// 1905/// \returns The destructor for this class. 1906CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) { 1907 return Class->getDestructor(); 1908} 1909 1910void ADLResult::insert(NamedDecl *New) { 1911 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())]; 1912 1913 // If we haven't yet seen a decl for this key, or the last decl 1914 // was exactly this one, we're done. 1915 if (Old == 0 || Old == New) { 1916 Old = New; 1917 return; 1918 } 1919 1920 // Otherwise, decide which is a more recent redeclaration. 1921 FunctionDecl *OldFD, *NewFD; 1922 if (isa<FunctionTemplateDecl>(New)) { 1923 OldFD = cast<FunctionTemplateDecl>(Old)->getTemplatedDecl(); 1924 NewFD = cast<FunctionTemplateDecl>(New)->getTemplatedDecl(); 1925 } else { 1926 OldFD = cast<FunctionDecl>(Old); 1927 NewFD = cast<FunctionDecl>(New); 1928 } 1929 1930 FunctionDecl *Cursor = NewFD; 1931 while (true) { 1932 Cursor = Cursor->getPreviousDeclaration(); 1933 1934 // If we got to the end without finding OldFD, OldFD is the newer 1935 // declaration; leave things as they are. 1936 if (!Cursor) return; 1937 1938 // If we do find OldFD, then NewFD is newer. 1939 if (Cursor == OldFD) break; 1940 1941 // Otherwise, keep looking. 1942 } 1943 1944 Old = New; 1945} 1946 1947void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator, 1948 Expr **Args, unsigned NumArgs, 1949 ADLResult &Result) { 1950 // Find all of the associated namespaces and classes based on the 1951 // arguments we have. 1952 AssociatedNamespaceSet AssociatedNamespaces; 1953 AssociatedClassSet AssociatedClasses; 1954 FindAssociatedClassesAndNamespaces(Args, NumArgs, 1955 AssociatedNamespaces, 1956 AssociatedClasses); 1957 1958 QualType T1, T2; 1959 if (Operator) { 1960 T1 = Args[0]->getType(); 1961 if (NumArgs >= 2) 1962 T2 = Args[1]->getType(); 1963 } 1964 1965 // C++ [basic.lookup.argdep]p3: 1966 // Let X be the lookup set produced by unqualified lookup (3.4.1) 1967 // and let Y be the lookup set produced by argument dependent 1968 // lookup (defined as follows). If X contains [...] then Y is 1969 // empty. Otherwise Y is the set of declarations found in the 1970 // namespaces associated with the argument types as described 1971 // below. The set of declarations found by the lookup of the name 1972 // is the union of X and Y. 1973 // 1974 // Here, we compute Y and add its members to the overloaded 1975 // candidate set. 1976 for (AssociatedNamespaceSet::iterator NS = AssociatedNamespaces.begin(), 1977 NSEnd = AssociatedNamespaces.end(); 1978 NS != NSEnd; ++NS) { 1979 // When considering an associated namespace, the lookup is the 1980 // same as the lookup performed when the associated namespace is 1981 // used as a qualifier (3.4.3.2) except that: 1982 // 1983 // -- Any using-directives in the associated namespace are 1984 // ignored. 1985 // 1986 // -- Any namespace-scope friend functions declared in 1987 // associated classes are visible within their respective 1988 // namespaces even if they are not visible during an ordinary 1989 // lookup (11.4). 1990 DeclContext::lookup_iterator I, E; 1991 for (llvm::tie(I, E) = (*NS)->lookup(Name); I != E; ++I) { 1992 NamedDecl *D = *I; 1993 // If the only declaration here is an ordinary friend, consider 1994 // it only if it was declared in an associated classes. 1995 if (D->getIdentifierNamespace() == Decl::IDNS_OrdinaryFriend) { 1996 DeclContext *LexDC = D->getLexicalDeclContext(); 1997 if (!AssociatedClasses.count(cast<CXXRecordDecl>(LexDC))) 1998 continue; 1999 } 2000 2001 if (isa<UsingShadowDecl>(D)) 2002 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2003 2004 if (isa<FunctionDecl>(D)) { 2005 if (Operator && 2006 !IsAcceptableNonMemberOperatorCandidate(cast<FunctionDecl>(D), 2007 T1, T2, Context)) 2008 continue; 2009 } else if (!isa<FunctionTemplateDecl>(D)) 2010 continue; 2011 2012 Result.insert(D); 2013 } 2014 } 2015} 2016 2017//---------------------------------------------------------------------------- 2018// Search for all visible declarations. 2019//---------------------------------------------------------------------------- 2020VisibleDeclConsumer::~VisibleDeclConsumer() { } 2021 2022namespace { 2023 2024class ShadowContextRAII; 2025 2026class VisibleDeclsRecord { 2027public: 2028 /// \brief An entry in the shadow map, which is optimized to store a 2029 /// single declaration (the common case) but can also store a list 2030 /// of declarations. 2031 class ShadowMapEntry { 2032 typedef llvm::SmallVector<NamedDecl *, 4> DeclVector; 2033 2034 /// \brief Contains either the solitary NamedDecl * or a vector 2035 /// of declarations. 2036 llvm::PointerUnion<NamedDecl *, DeclVector*> DeclOrVector; 2037 2038 public: 2039 ShadowMapEntry() : DeclOrVector() { } 2040 2041 void Add(NamedDecl *ND); 2042 void Destroy(); 2043 2044 // Iteration. 2045 typedef NamedDecl **iterator; 2046 iterator begin(); 2047 iterator end(); 2048 }; 2049 2050private: 2051 /// \brief A mapping from declaration names to the declarations that have 2052 /// this name within a particular scope. 2053 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap; 2054 2055 /// \brief A list of shadow maps, which is used to model name hiding. 2056 std::list<ShadowMap> ShadowMaps; 2057 2058 /// \brief The declaration contexts we have already visited. 2059 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts; 2060 2061 friend class ShadowContextRAII; 2062 2063public: 2064 /// \brief Determine whether we have already visited this context 2065 /// (and, if not, note that we are going to visit that context now). 2066 bool visitedContext(DeclContext *Ctx) { 2067 return !VisitedContexts.insert(Ctx); 2068 } 2069 2070 /// \brief Determine whether the given declaration is hidden in the 2071 /// current scope. 2072 /// 2073 /// \returns the declaration that hides the given declaration, or 2074 /// NULL if no such declaration exists. 2075 NamedDecl *checkHidden(NamedDecl *ND); 2076 2077 /// \brief Add a declaration to the current shadow map. 2078 void add(NamedDecl *ND) { ShadowMaps.back()[ND->getDeclName()].Add(ND); } 2079}; 2080 2081/// \brief RAII object that records when we've entered a shadow context. 2082class ShadowContextRAII { 2083 VisibleDeclsRecord &Visible; 2084 2085 typedef VisibleDeclsRecord::ShadowMap ShadowMap; 2086 2087public: 2088 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) { 2089 Visible.ShadowMaps.push_back(ShadowMap()); 2090 } 2091 2092 ~ShadowContextRAII() { 2093 for (ShadowMap::iterator E = Visible.ShadowMaps.back().begin(), 2094 EEnd = Visible.ShadowMaps.back().end(); 2095 E != EEnd; 2096 ++E) 2097 E->second.Destroy(); 2098 2099 Visible.ShadowMaps.pop_back(); 2100 } 2101}; 2102 2103} // end anonymous namespace 2104 2105void VisibleDeclsRecord::ShadowMapEntry::Add(NamedDecl *ND) { 2106 if (DeclOrVector.isNull()) { 2107 // 0 - > 1 elements: just set the single element information. 2108 DeclOrVector = ND; 2109 return; 2110 } 2111 2112 if (NamedDecl *PrevND = DeclOrVector.dyn_cast<NamedDecl *>()) { 2113 // 1 -> 2 elements: create the vector of results and push in the 2114 // existing declaration. 2115 DeclVector *Vec = new DeclVector; 2116 Vec->push_back(PrevND); 2117 DeclOrVector = Vec; 2118 } 2119 2120 // Add the new element to the end of the vector. 2121 DeclOrVector.get<DeclVector*>()->push_back(ND); 2122} 2123 2124void VisibleDeclsRecord::ShadowMapEntry::Destroy() { 2125 if (DeclVector *Vec = DeclOrVector.dyn_cast<DeclVector *>()) { 2126 delete Vec; 2127 DeclOrVector = ((NamedDecl *)0); 2128 } 2129} 2130 2131VisibleDeclsRecord::ShadowMapEntry::iterator 2132VisibleDeclsRecord::ShadowMapEntry::begin() { 2133 if (DeclOrVector.isNull()) 2134 return 0; 2135 2136 if (DeclOrVector.dyn_cast<NamedDecl *>()) 2137 return &reinterpret_cast<NamedDecl*&>(DeclOrVector); 2138 2139 return DeclOrVector.get<DeclVector *>()->begin(); 2140} 2141 2142VisibleDeclsRecord::ShadowMapEntry::iterator 2143VisibleDeclsRecord::ShadowMapEntry::end() { 2144 if (DeclOrVector.isNull()) 2145 return 0; 2146 2147 if (DeclOrVector.dyn_cast<NamedDecl *>()) 2148 return &reinterpret_cast<NamedDecl*&>(DeclOrVector) + 1; 2149 2150 return DeclOrVector.get<DeclVector *>()->end(); 2151} 2152 2153NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) { 2154 // Look through using declarations. 2155 ND = ND->getUnderlyingDecl(); 2156 2157 unsigned IDNS = ND->getIdentifierNamespace(); 2158 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin(); 2159 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend(); 2160 SM != SMEnd; ++SM) { 2161 ShadowMap::iterator Pos = SM->find(ND->getDeclName()); 2162 if (Pos == SM->end()) 2163 continue; 2164 2165 for (ShadowMapEntry::iterator I = Pos->second.begin(), 2166 IEnd = Pos->second.end(); 2167 I != IEnd; ++I) { 2168 // A tag declaration does not hide a non-tag declaration. 2169 if ((*I)->hasTagIdentifierNamespace() && 2170 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary | 2171 Decl::IDNS_ObjCProtocol))) 2172 continue; 2173 2174 // Protocols are in distinct namespaces from everything else. 2175 if ((((*I)->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol) 2176 || (IDNS & Decl::IDNS_ObjCProtocol)) && 2177 (*I)->getIdentifierNamespace() != IDNS) 2178 continue; 2179 2180 // Functions and function templates in the same scope overload 2181 // rather than hide. FIXME: Look for hiding based on function 2182 // signatures! 2183 if ((*I)->isFunctionOrFunctionTemplate() && 2184 ND->isFunctionOrFunctionTemplate() && 2185 SM == ShadowMaps.rbegin()) 2186 continue; 2187 2188 // We've found a declaration that hides this one. 2189 return *I; 2190 } 2191 } 2192 2193 return 0; 2194} 2195 2196static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result, 2197 bool QualifiedNameLookup, 2198 bool InBaseClass, 2199 VisibleDeclConsumer &Consumer, 2200 VisibleDeclsRecord &Visited) { 2201 if (!Ctx) 2202 return; 2203 2204 // Make sure we don't visit the same context twice. 2205 if (Visited.visitedContext(Ctx->getPrimaryContext())) 2206 return; 2207 2208 // Enumerate all of the results in this context. 2209 for (DeclContext *CurCtx = Ctx->getPrimaryContext(); CurCtx; 2210 CurCtx = CurCtx->getNextContext()) { 2211 for (DeclContext::decl_iterator D = CurCtx->decls_begin(), 2212 DEnd = CurCtx->decls_end(); 2213 D != DEnd; ++D) { 2214 if (NamedDecl *ND = dyn_cast<NamedDecl>(*D)) 2215 if (Result.isAcceptableDecl(ND)) { 2216 Consumer.FoundDecl(ND, Visited.checkHidden(ND), InBaseClass); 2217 Visited.add(ND); 2218 } 2219 2220 // Visit transparent contexts inside this context. 2221 if (DeclContext *InnerCtx = dyn_cast<DeclContext>(*D)) { 2222 if (InnerCtx->isTransparentContext()) 2223 LookupVisibleDecls(InnerCtx, Result, QualifiedNameLookup, InBaseClass, 2224 Consumer, Visited); 2225 } 2226 } 2227 } 2228 2229 // Traverse using directives for qualified name lookup. 2230 if (QualifiedNameLookup) { 2231 ShadowContextRAII Shadow(Visited); 2232 DeclContext::udir_iterator I, E; 2233 for (llvm::tie(I, E) = Ctx->getUsingDirectives(); I != E; ++I) { 2234 LookupVisibleDecls((*I)->getNominatedNamespace(), Result, 2235 QualifiedNameLookup, InBaseClass, Consumer, Visited); 2236 } 2237 } 2238 2239 // Traverse the contexts of inherited C++ classes. 2240 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) { 2241 if (!Record->hasDefinition()) 2242 return; 2243 2244 for (CXXRecordDecl::base_class_iterator B = Record->bases_begin(), 2245 BEnd = Record->bases_end(); 2246 B != BEnd; ++B) { 2247 QualType BaseType = B->getType(); 2248 2249 // Don't look into dependent bases, because name lookup can't look 2250 // there anyway. 2251 if (BaseType->isDependentType()) 2252 continue; 2253 2254 const RecordType *Record = BaseType->getAs<RecordType>(); 2255 if (!Record) 2256 continue; 2257 2258 // FIXME: It would be nice to be able to determine whether referencing 2259 // a particular member would be ambiguous. For example, given 2260 // 2261 // struct A { int member; }; 2262 // struct B { int member; }; 2263 // struct C : A, B { }; 2264 // 2265 // void f(C *c) { c->### } 2266 // 2267 // accessing 'member' would result in an ambiguity. However, we 2268 // could be smart enough to qualify the member with the base 2269 // class, e.g., 2270 // 2271 // c->B::member 2272 // 2273 // or 2274 // 2275 // c->A::member 2276 2277 // Find results in this base class (and its bases). 2278 ShadowContextRAII Shadow(Visited); 2279 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup, 2280 true, Consumer, Visited); 2281 } 2282 } 2283 2284 // Traverse the contexts of Objective-C classes. 2285 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) { 2286 // Traverse categories. 2287 for (ObjCCategoryDecl *Category = IFace->getCategoryList(); 2288 Category; Category = Category->getNextClassCategory()) { 2289 ShadowContextRAII Shadow(Visited); 2290 LookupVisibleDecls(Category, Result, QualifiedNameLookup, false, 2291 Consumer, Visited); 2292 } 2293 2294 // Traverse protocols. 2295 for (ObjCInterfaceDecl::protocol_iterator I = IFace->protocol_begin(), 2296 E = IFace->protocol_end(); I != E; ++I) { 2297 ShadowContextRAII Shadow(Visited); 2298 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2299 Visited); 2300 } 2301 2302 // Traverse the superclass. 2303 if (IFace->getSuperClass()) { 2304 ShadowContextRAII Shadow(Visited); 2305 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup, 2306 true, Consumer, Visited); 2307 } 2308 2309 // If there is an implementation, traverse it. We do this to find 2310 // synthesized ivars. 2311 if (IFace->getImplementation()) { 2312 ShadowContextRAII Shadow(Visited); 2313 LookupVisibleDecls(IFace->getImplementation(), Result, 2314 QualifiedNameLookup, true, Consumer, Visited); 2315 } 2316 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) { 2317 for (ObjCProtocolDecl::protocol_iterator I = Protocol->protocol_begin(), 2318 E = Protocol->protocol_end(); I != E; ++I) { 2319 ShadowContextRAII Shadow(Visited); 2320 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2321 Visited); 2322 } 2323 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) { 2324 for (ObjCCategoryDecl::protocol_iterator I = Category->protocol_begin(), 2325 E = Category->protocol_end(); I != E; ++I) { 2326 ShadowContextRAII Shadow(Visited); 2327 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2328 Visited); 2329 } 2330 2331 // If there is an implementation, traverse it. 2332 if (Category->getImplementation()) { 2333 ShadowContextRAII Shadow(Visited); 2334 LookupVisibleDecls(Category->getImplementation(), Result, 2335 QualifiedNameLookup, true, Consumer, Visited); 2336 } 2337 } 2338} 2339 2340static void LookupVisibleDecls(Scope *S, LookupResult &Result, 2341 UnqualUsingDirectiveSet &UDirs, 2342 VisibleDeclConsumer &Consumer, 2343 VisibleDeclsRecord &Visited) { 2344 if (!S) 2345 return; 2346 2347 if (!S->getEntity() || !S->getParent() || 2348 ((DeclContext *)S->getEntity())->isFunctionOrMethod()) { 2349 // Walk through the declarations in this Scope. 2350 for (Scope::decl_iterator D = S->decl_begin(), DEnd = S->decl_end(); 2351 D != DEnd; ++D) { 2352 if (NamedDecl *ND = dyn_cast<NamedDecl>((Decl *)((*D).get()))) 2353 if (Result.isAcceptableDecl(ND)) { 2354 Consumer.FoundDecl(ND, Visited.checkHidden(ND), false); 2355 Visited.add(ND); 2356 } 2357 } 2358 } 2359 2360 // FIXME: C++ [temp.local]p8 2361 DeclContext *Entity = 0; 2362 if (S->getEntity()) { 2363 // Look into this scope's declaration context, along with any of its 2364 // parent lookup contexts (e.g., enclosing classes), up to the point 2365 // where we hit the context stored in the next outer scope. 2366 Entity = (DeclContext *)S->getEntity(); 2367 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME 2368 2369 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx); 2370 Ctx = Ctx->getLookupParent()) { 2371 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 2372 if (Method->isInstanceMethod()) { 2373 // For instance methods, look for ivars in the method's interface. 2374 LookupResult IvarResult(Result.getSema(), Result.getLookupName(), 2375 Result.getNameLoc(), Sema::LookupMemberName); 2376 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) 2377 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false, 2378 /*InBaseClass=*/false, Consumer, Visited); 2379 } 2380 2381 // We've already performed all of the name lookup that we need 2382 // to for Objective-C methods; the next context will be the 2383 // outer scope. 2384 break; 2385 } 2386 2387 if (Ctx->isFunctionOrMethod()) 2388 continue; 2389 2390 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false, 2391 /*InBaseClass=*/false, Consumer, Visited); 2392 } 2393 } else if (!S->getParent()) { 2394 // Look into the translation unit scope. We walk through the translation 2395 // unit's declaration context, because the Scope itself won't have all of 2396 // the declarations if we loaded a precompiled header. 2397 // FIXME: We would like the translation unit's Scope object to point to the 2398 // translation unit, so we don't need this special "if" branch. However, 2399 // doing so would force the normal C++ name-lookup code to look into the 2400 // translation unit decl when the IdentifierInfo chains would suffice. 2401 // Once we fix that problem (which is part of a more general "don't look 2402 // in DeclContexts unless we have to" optimization), we can eliminate this. 2403 Entity = Result.getSema().Context.getTranslationUnitDecl(); 2404 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false, 2405 /*InBaseClass=*/false, Consumer, Visited); 2406 } 2407 2408 if (Entity) { 2409 // Lookup visible declarations in any namespaces found by using 2410 // directives. 2411 UnqualUsingDirectiveSet::const_iterator UI, UEnd; 2412 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(Entity); 2413 for (; UI != UEnd; ++UI) 2414 LookupVisibleDecls(const_cast<DeclContext *>(UI->getNominatedNamespace()), 2415 Result, /*QualifiedNameLookup=*/false, 2416 /*InBaseClass=*/false, Consumer, Visited); 2417 } 2418 2419 // Lookup names in the parent scope. 2420 ShadowContextRAII Shadow(Visited); 2421 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited); 2422} 2423 2424void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind, 2425 VisibleDeclConsumer &Consumer) { 2426 // Determine the set of using directives available during 2427 // unqualified name lookup. 2428 Scope *Initial = S; 2429 UnqualUsingDirectiveSet UDirs; 2430 if (getLangOptions().CPlusPlus) { 2431 // Find the first namespace or translation-unit scope. 2432 while (S && !isNamespaceOrTranslationUnitScope(S)) 2433 S = S->getParent(); 2434 2435 UDirs.visitScopeChain(Initial, S); 2436 } 2437 UDirs.done(); 2438 2439 // Look for visible declarations. 2440 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2441 VisibleDeclsRecord Visited; 2442 ShadowContextRAII Shadow(Visited); 2443 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited); 2444} 2445 2446void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind, 2447 VisibleDeclConsumer &Consumer) { 2448 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2449 VisibleDeclsRecord Visited; 2450 ShadowContextRAII Shadow(Visited); 2451 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true, 2452 /*InBaseClass=*/false, Consumer, Visited); 2453} 2454 2455//---------------------------------------------------------------------------- 2456// Typo correction 2457//---------------------------------------------------------------------------- 2458 2459namespace { 2460class TypoCorrectionConsumer : public VisibleDeclConsumer { 2461 /// \brief The name written that is a typo in the source. 2462 llvm::StringRef Typo; 2463 2464 /// \brief The results found that have the smallest edit distance 2465 /// found (so far) with the typo name. 2466 llvm::SmallVector<NamedDecl *, 4> BestResults; 2467 2468 /// \brief The keywords that have the smallest edit distance. 2469 llvm::SmallVector<IdentifierInfo *, 4> BestKeywords; 2470 2471 /// \brief The best edit distance found so far. 2472 unsigned BestEditDistance; 2473 2474public: 2475 explicit TypoCorrectionConsumer(IdentifierInfo *Typo) 2476 : Typo(Typo->getName()) { } 2477 2478 virtual void FoundDecl(NamedDecl *ND, NamedDecl *Hiding, bool InBaseClass); 2479 void addKeywordResult(ASTContext &Context, llvm::StringRef Keyword); 2480 2481 typedef llvm::SmallVector<NamedDecl *, 4>::const_iterator iterator; 2482 iterator begin() const { return BestResults.begin(); } 2483 iterator end() const { return BestResults.end(); } 2484 void clear_decls() { BestResults.clear(); } 2485 2486 bool empty() const { return BestResults.empty() && BestKeywords.empty(); } 2487 2488 typedef llvm::SmallVector<IdentifierInfo *, 4>::const_iterator 2489 keyword_iterator; 2490 keyword_iterator keyword_begin() const { return BestKeywords.begin(); } 2491 keyword_iterator keyword_end() const { return BestKeywords.end(); } 2492 bool keyword_empty() const { return BestKeywords.empty(); } 2493 unsigned keyword_size() const { return BestKeywords.size(); } 2494 2495 unsigned getBestEditDistance() const { return BestEditDistance; } 2496}; 2497 2498} 2499 2500void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding, 2501 bool InBaseClass) { 2502 // Don't consider hidden names for typo correction. 2503 if (Hiding) 2504 return; 2505 2506 // Only consider entities with identifiers for names, ignoring 2507 // special names (constructors, overloaded operators, selectors, 2508 // etc.). 2509 IdentifierInfo *Name = ND->getIdentifier(); 2510 if (!Name) 2511 return; 2512 2513 // Compute the edit distance between the typo and the name of this 2514 // entity. If this edit distance is not worse than the best edit 2515 // distance we've seen so far, add it to the list of results. 2516 unsigned ED = Typo.edit_distance(Name->getName()); 2517 if (!BestResults.empty() || !BestKeywords.empty()) { 2518 if (ED < BestEditDistance) { 2519 // This result is better than any we've seen before; clear out 2520 // the previous results. 2521 BestResults.clear(); 2522 BestKeywords.clear(); 2523 BestEditDistance = ED; 2524 } else if (ED > BestEditDistance) { 2525 // This result is worse than the best results we've seen so far; 2526 // ignore it. 2527 return; 2528 } 2529 } else 2530 BestEditDistance = ED; 2531 2532 BestResults.push_back(ND); 2533} 2534 2535void TypoCorrectionConsumer::addKeywordResult(ASTContext &Context, 2536 llvm::StringRef Keyword) { 2537 // Compute the edit distance between the typo and this keyword. 2538 // If this edit distance is not worse than the best edit 2539 // distance we've seen so far, add it to the list of results. 2540 unsigned ED = Typo.edit_distance(Keyword); 2541 if (!BestResults.empty() || !BestKeywords.empty()) { 2542 if (ED < BestEditDistance) { 2543 BestResults.clear(); 2544 BestKeywords.clear(); 2545 BestEditDistance = ED; 2546 } else if (ED > BestEditDistance) { 2547 // This result is worse than the best results we've seen so far; 2548 // ignore it. 2549 return; 2550 } 2551 } else 2552 BestEditDistance = ED; 2553 2554 BestKeywords.push_back(&Context.Idents.get(Keyword)); 2555} 2556 2557/// \brief Try to "correct" a typo in the source code by finding 2558/// visible declarations whose names are similar to the name that was 2559/// present in the source code. 2560/// 2561/// \param Res the \c LookupResult structure that contains the name 2562/// that was present in the source code along with the name-lookup 2563/// criteria used to search for the name. On success, this structure 2564/// will contain the results of name lookup. 2565/// 2566/// \param S the scope in which name lookup occurs. 2567/// 2568/// \param SS the nested-name-specifier that precedes the name we're 2569/// looking for, if present. 2570/// 2571/// \param MemberContext if non-NULL, the context in which to look for 2572/// a member access expression. 2573/// 2574/// \param EnteringContext whether we're entering the context described by 2575/// the nested-name-specifier SS. 2576/// 2577/// \param CTC The context in which typo correction occurs, which impacts the 2578/// set of keywords permitted. 2579/// 2580/// \param OPT when non-NULL, the search for visible declarations will 2581/// also walk the protocols in the qualified interfaces of \p OPT. 2582/// 2583/// \returns the corrected name if the typo was corrected, otherwise returns an 2584/// empty \c DeclarationName. When a typo was corrected, the result structure 2585/// may contain the results of name lookup for the correct name or it may be 2586/// empty. 2587DeclarationName Sema::CorrectTypo(LookupResult &Res, Scope *S, CXXScopeSpec *SS, 2588 DeclContext *MemberContext, 2589 bool EnteringContext, 2590 CorrectTypoContext CTC, 2591 const ObjCObjectPointerType *OPT) { 2592 if (Diags.hasFatalErrorOccurred()) 2593 return DeclarationName(); 2594 2595 // Provide a stop gap for files that are just seriously broken. Trying 2596 // to correct all typos can turn into a HUGE performance penalty, causing 2597 // some files to take minutes to get rejected by the parser. 2598 // FIXME: Is this the right solution? 2599 if (TyposCorrected == 20) 2600 return DeclarationName(); 2601 ++TyposCorrected; 2602 2603 // We only attempt to correct typos for identifiers. 2604 IdentifierInfo *Typo = Res.getLookupName().getAsIdentifierInfo(); 2605 if (!Typo) 2606 return DeclarationName(); 2607 2608 // If the scope specifier itself was invalid, don't try to correct 2609 // typos. 2610 if (SS && SS->isInvalid()) 2611 return DeclarationName(); 2612 2613 // Never try to correct typos during template deduction or 2614 // instantiation. 2615 if (!ActiveTemplateInstantiations.empty()) 2616 return DeclarationName(); 2617 2618 TypoCorrectionConsumer Consumer(Typo); 2619 2620 // Perform name lookup to find visible, similarly-named entities. 2621 if (MemberContext) { 2622 LookupVisibleDecls(MemberContext, Res.getLookupKind(), Consumer); 2623 2624 // Look in qualified interfaces. 2625 if (OPT) { 2626 for (ObjCObjectPointerType::qual_iterator 2627 I = OPT->qual_begin(), E = OPT->qual_end(); 2628 I != E; ++I) 2629 LookupVisibleDecls(*I, Res.getLookupKind(), Consumer); 2630 } 2631 } else if (SS && SS->isSet()) { 2632 DeclContext *DC = computeDeclContext(*SS, EnteringContext); 2633 if (!DC) 2634 return DeclarationName(); 2635 2636 LookupVisibleDecls(DC, Res.getLookupKind(), Consumer); 2637 } else { 2638 LookupVisibleDecls(S, Res.getLookupKind(), Consumer); 2639 } 2640 2641 // Add context-dependent keywords. 2642 bool WantTypeSpecifiers = false; 2643 bool WantExpressionKeywords = false; 2644 bool WantCXXNamedCasts = false; 2645 bool WantRemainingKeywords = false; 2646 switch (CTC) { 2647 case CTC_Unknown: 2648 WantTypeSpecifiers = true; 2649 WantExpressionKeywords = true; 2650 WantCXXNamedCasts = true; 2651 WantRemainingKeywords = true; 2652 2653 if (ObjCMethodDecl *Method = getCurMethodDecl()) 2654 if (Method->getClassInterface() && 2655 Method->getClassInterface()->getSuperClass()) 2656 Consumer.addKeywordResult(Context, "super"); 2657 2658 break; 2659 2660 case CTC_NoKeywords: 2661 break; 2662 2663 case CTC_Type: 2664 WantTypeSpecifiers = true; 2665 break; 2666 2667 case CTC_ObjCMessageReceiver: 2668 Consumer.addKeywordResult(Context, "super"); 2669 // Fall through to handle message receivers like expressions. 2670 2671 case CTC_Expression: 2672 if (getLangOptions().CPlusPlus) 2673 WantTypeSpecifiers = true; 2674 WantExpressionKeywords = true; 2675 // Fall through to get C++ named casts. 2676 2677 case CTC_CXXCasts: 2678 WantCXXNamedCasts = true; 2679 break; 2680 2681 case CTC_MemberLookup: 2682 if (getLangOptions().CPlusPlus) 2683 Consumer.addKeywordResult(Context, "template"); 2684 break; 2685 } 2686 2687 if (WantTypeSpecifiers) { 2688 // Add type-specifier keywords to the set of results. 2689 const char *CTypeSpecs[] = { 2690 "char", "const", "double", "enum", "float", "int", "long", "short", 2691 "signed", "struct", "union", "unsigned", "void", "volatile", "_Bool", 2692 "_Complex", "_Imaginary", 2693 // storage-specifiers as well 2694 "extern", "inline", "static", "typedef" 2695 }; 2696 2697 const unsigned NumCTypeSpecs = sizeof(CTypeSpecs) / sizeof(CTypeSpecs[0]); 2698 for (unsigned I = 0; I != NumCTypeSpecs; ++I) 2699 Consumer.addKeywordResult(Context, CTypeSpecs[I]); 2700 2701 if (getLangOptions().C99) 2702 Consumer.addKeywordResult(Context, "restrict"); 2703 if (getLangOptions().Bool || getLangOptions().CPlusPlus) 2704 Consumer.addKeywordResult(Context, "bool"); 2705 2706 if (getLangOptions().CPlusPlus) { 2707 Consumer.addKeywordResult(Context, "class"); 2708 Consumer.addKeywordResult(Context, "typename"); 2709 Consumer.addKeywordResult(Context, "wchar_t"); 2710 2711 if (getLangOptions().CPlusPlus0x) { 2712 Consumer.addKeywordResult(Context, "char16_t"); 2713 Consumer.addKeywordResult(Context, "char32_t"); 2714 Consumer.addKeywordResult(Context, "constexpr"); 2715 Consumer.addKeywordResult(Context, "decltype"); 2716 Consumer.addKeywordResult(Context, "thread_local"); 2717 } 2718 } 2719 2720 if (getLangOptions().GNUMode) 2721 Consumer.addKeywordResult(Context, "typeof"); 2722 } 2723 2724 if (WantCXXNamedCasts && getLangOptions().CPlusPlus) { 2725 Consumer.addKeywordResult(Context, "const_cast"); 2726 Consumer.addKeywordResult(Context, "dynamic_cast"); 2727 Consumer.addKeywordResult(Context, "reinterpret_cast"); 2728 Consumer.addKeywordResult(Context, "static_cast"); 2729 } 2730 2731 if (WantExpressionKeywords) { 2732 Consumer.addKeywordResult(Context, "sizeof"); 2733 if (getLangOptions().Bool || getLangOptions().CPlusPlus) { 2734 Consumer.addKeywordResult(Context, "false"); 2735 Consumer.addKeywordResult(Context, "true"); 2736 } 2737 2738 if (getLangOptions().CPlusPlus) { 2739 const char *CXXExprs[] = { 2740 "delete", "new", "operator", "throw", "typeid" 2741 }; 2742 const unsigned NumCXXExprs = sizeof(CXXExprs) / sizeof(CXXExprs[0]); 2743 for (unsigned I = 0; I != NumCXXExprs; ++I) 2744 Consumer.addKeywordResult(Context, CXXExprs[I]); 2745 2746 if (isa<CXXMethodDecl>(CurContext) && 2747 cast<CXXMethodDecl>(CurContext)->isInstance()) 2748 Consumer.addKeywordResult(Context, "this"); 2749 2750 if (getLangOptions().CPlusPlus0x) { 2751 Consumer.addKeywordResult(Context, "alignof"); 2752 Consumer.addKeywordResult(Context, "nullptr"); 2753 } 2754 } 2755 } 2756 2757 if (WantRemainingKeywords) { 2758 if (getCurFunctionOrMethodDecl() || getCurBlock()) { 2759 // Statements. 2760 const char *CStmts[] = { 2761 "do", "else", "for", "goto", "if", "return", "switch", "while" }; 2762 const unsigned NumCStmts = sizeof(CStmts) / sizeof(CStmts[0]); 2763 for (unsigned I = 0; I != NumCStmts; ++I) 2764 Consumer.addKeywordResult(Context, CStmts[I]); 2765 2766 if (getLangOptions().CPlusPlus) { 2767 Consumer.addKeywordResult(Context, "catch"); 2768 Consumer.addKeywordResult(Context, "try"); 2769 } 2770 2771 if (S && S->getBreakParent()) 2772 Consumer.addKeywordResult(Context, "break"); 2773 2774 if (S && S->getContinueParent()) 2775 Consumer.addKeywordResult(Context, "continue"); 2776 2777 if (!getSwitchStack().empty()) { 2778 Consumer.addKeywordResult(Context, "case"); 2779 Consumer.addKeywordResult(Context, "default"); 2780 } 2781 } else { 2782 if (getLangOptions().CPlusPlus) { 2783 Consumer.addKeywordResult(Context, "namespace"); 2784 Consumer.addKeywordResult(Context, "template"); 2785 } 2786 2787 if (S && S->isClassScope()) { 2788 Consumer.addKeywordResult(Context, "explicit"); 2789 Consumer.addKeywordResult(Context, "friend"); 2790 Consumer.addKeywordResult(Context, "mutable"); 2791 Consumer.addKeywordResult(Context, "private"); 2792 Consumer.addKeywordResult(Context, "protected"); 2793 Consumer.addKeywordResult(Context, "public"); 2794 Consumer.addKeywordResult(Context, "virtual"); 2795 } 2796 } 2797 2798 if (getLangOptions().CPlusPlus) { 2799 Consumer.addKeywordResult(Context, "using"); 2800 2801 if (getLangOptions().CPlusPlus0x) 2802 Consumer.addKeywordResult(Context, "static_assert"); 2803 } 2804 } 2805 2806 // If we haven't found anything, we're done. 2807 if (Consumer.empty()) 2808 return DeclarationName(); 2809 2810 // Only allow a single, closest name in the result set (it's okay to 2811 // have overloads of that name, though). 2812 DeclarationName BestName; 2813 NamedDecl *BestIvarOrPropertyDecl = 0; 2814 bool FoundIvarOrPropertyDecl = false; 2815 2816 // Check all of the declaration results to find the best name so far. 2817 for (TypoCorrectionConsumer::iterator I = Consumer.begin(), 2818 IEnd = Consumer.end(); 2819 I != IEnd; ++I) { 2820 if (!BestName) 2821 BestName = (*I)->getDeclName(); 2822 else if (BestName != (*I)->getDeclName()) 2823 return DeclarationName(); 2824 2825 // \brief Keep track of either an Objective-C ivar or a property, but not 2826 // both. 2827 if (isa<ObjCIvarDecl>(*I) || isa<ObjCPropertyDecl>(*I)) { 2828 if (FoundIvarOrPropertyDecl) 2829 BestIvarOrPropertyDecl = 0; 2830 else { 2831 BestIvarOrPropertyDecl = *I; 2832 FoundIvarOrPropertyDecl = true; 2833 } 2834 } 2835 } 2836 2837 // Now check all of the keyword results to find the best name. 2838 switch (Consumer.keyword_size()) { 2839 case 0: 2840 // No keywords matched. 2841 break; 2842 2843 case 1: 2844 // If we already have a name 2845 if (!BestName) { 2846 // We did not have anything previously, 2847 BestName = *Consumer.keyword_begin(); 2848 } else if (BestName.getAsIdentifierInfo() == *Consumer.keyword_begin()) { 2849 // We have a declaration with the same name as a context-sensitive 2850 // keyword. The keyword takes precedence. 2851 BestIvarOrPropertyDecl = 0; 2852 FoundIvarOrPropertyDecl = false; 2853 Consumer.clear_decls(); 2854 } else if (CTC == CTC_ObjCMessageReceiver && 2855 (*Consumer.keyword_begin())->isStr("super")) { 2856 // In an Objective-C message send, give the "super" keyword a slight 2857 // edge over entities not in function or method scope. 2858 for (TypoCorrectionConsumer::iterator I = Consumer.begin(), 2859 IEnd = Consumer.end(); 2860 I != IEnd; ++I) { 2861 if ((*I)->getDeclName() == BestName) { 2862 if ((*I)->getDeclContext()->isFunctionOrMethod()) 2863 return DeclarationName(); 2864 } 2865 } 2866 2867 // Everything found was outside a function or method; the 'super' 2868 // keyword takes precedence. 2869 BestIvarOrPropertyDecl = 0; 2870 FoundIvarOrPropertyDecl = false; 2871 Consumer.clear_decls(); 2872 BestName = *Consumer.keyword_begin(); 2873 } else { 2874 // Name collision; we will not correct typos. 2875 return DeclarationName(); 2876 } 2877 break; 2878 2879 default: 2880 // Name collision; we will not correct typos. 2881 return DeclarationName(); 2882 } 2883 2884 // BestName is the closest viable name to what the user 2885 // typed. However, to make sure that we don't pick something that's 2886 // way off, make sure that the user typed at least 3 characters for 2887 // each correction. 2888 unsigned ED = Consumer.getBestEditDistance(); 2889 if (ED == 0 || !BestName.getAsIdentifierInfo() || 2890 (BestName.getAsIdentifierInfo()->getName().size() / ED) < 3) 2891 return DeclarationName(); 2892 2893 // Perform name lookup again with the name we chose, and declare 2894 // success if we found something that was not ambiguous. 2895 Res.clear(); 2896 Res.setLookupName(BestName); 2897 2898 // If we found an ivar or property, add that result; no further 2899 // lookup is required. 2900 if (BestIvarOrPropertyDecl) 2901 Res.addDecl(BestIvarOrPropertyDecl); 2902 // If we're looking into the context of a member, perform qualified 2903 // name lookup on the best name. 2904 else if (!Consumer.keyword_empty()) { 2905 // The best match was a keyword. Return it. 2906 return BestName; 2907 } else if (MemberContext) 2908 LookupQualifiedName(Res, MemberContext); 2909 // Perform lookup as if we had just parsed the best name. 2910 else 2911 LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false, 2912 EnteringContext); 2913 2914 if (Res.isAmbiguous()) { 2915 Res.suppressDiagnostics(); 2916 return DeclarationName(); 2917 } 2918 2919 if (Res.getResultKind() != LookupResult::NotFound) 2920 return BestName; 2921 2922 return DeclarationName(); 2923} 2924