SemaLookup.cpp revision 433d7d2c70b9be3f9edd40579f512ecab8755049
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 196static bool IsAcceptableIDNS(NamedDecl *D, unsigned IDNS) { 197 return D->isInIdentifierNamespace(IDNS); 198} 199 200static bool IsAcceptableOperatorName(NamedDecl *D, unsigned IDNS) { 201 return D->isInIdentifierNamespace(IDNS) && 202 !D->getDeclContext()->isRecord(); 203} 204 205static bool IsAcceptableNestedNameSpecifierName(NamedDecl *D, unsigned IDNS) { 206 // This lookup ignores everything that isn't a type. 207 208 // This is a fast check for the far most common case. 209 if (D->isInIdentifierNamespace(Decl::IDNS_Tag)) 210 return true; 211 212 if (isa<UsingShadowDecl>(D)) 213 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 214 215 return isa<TypeDecl>(D); 216} 217 218static bool IsAcceptableNamespaceName(NamedDecl *D, unsigned IDNS) { 219 // We don't need to look through using decls here because 220 // using decls aren't allowed to name namespaces. 221 222 return isa<NamespaceDecl>(D) || isa<NamespaceAliasDecl>(D); 223} 224 225/// Gets the default result filter for the given lookup. 226static inline 227LookupResult::ResultFilter getResultFilter(Sema::LookupNameKind NameKind) { 228 switch (NameKind) { 229 case Sema::LookupOrdinaryName: 230 case Sema::LookupTagName: 231 case Sema::LookupMemberName: 232 case Sema::LookupRedeclarationWithLinkage: // FIXME: check linkage, scoping 233 case Sema::LookupUsingDeclName: 234 case Sema::LookupObjCProtocolName: 235 case Sema::LookupObjCImplementationName: 236 return &IsAcceptableIDNS; 237 238 case Sema::LookupOperatorName: 239 return &IsAcceptableOperatorName; 240 241 case Sema::LookupNestedNameSpecifierName: 242 return &IsAcceptableNestedNameSpecifierName; 243 244 case Sema::LookupNamespaceName: 245 return &IsAcceptableNamespaceName; 246 } 247 248 llvm_unreachable("unkknown lookup kind"); 249 return 0; 250} 251 252// Retrieve the set of identifier namespaces that correspond to a 253// specific kind of name lookup. 254static inline unsigned getIDNS(Sema::LookupNameKind NameKind, 255 bool CPlusPlus, 256 bool Redeclaration) { 257 unsigned IDNS = 0; 258 switch (NameKind) { 259 case Sema::LookupOrdinaryName: 260 case Sema::LookupOperatorName: 261 case Sema::LookupRedeclarationWithLinkage: 262 IDNS = Decl::IDNS_Ordinary; 263 if (CPlusPlus) { 264 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member; 265 if (Redeclaration) IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend; 266 } 267 break; 268 269 case Sema::LookupTagName: 270 IDNS = Decl::IDNS_Tag; 271 if (CPlusPlus && Redeclaration) 272 IDNS |= Decl::IDNS_TagFriend; 273 break; 274 275 case Sema::LookupMemberName: 276 IDNS = Decl::IDNS_Member; 277 if (CPlusPlus) 278 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary; 279 break; 280 281 case Sema::LookupNestedNameSpecifierName: 282 case Sema::LookupNamespaceName: 283 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member; 284 break; 285 286 case Sema::LookupUsingDeclName: 287 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag 288 | Decl::IDNS_Member | Decl::IDNS_Using; 289 break; 290 291 case Sema::LookupObjCProtocolName: 292 IDNS = Decl::IDNS_ObjCProtocol; 293 break; 294 295 case Sema::LookupObjCImplementationName: 296 IDNS = Decl::IDNS_ObjCImplementation; 297 break; 298 } 299 return IDNS; 300} 301 302void LookupResult::configure() { 303 IDNS = getIDNS(LookupKind, 304 SemaRef.getLangOptions().CPlusPlus, 305 isForRedeclaration()); 306 IsAcceptableFn = getResultFilter(LookupKind); 307 308 // If we're looking for one of the allocation or deallocation 309 // operators, make sure that the implicitly-declared new and delete 310 // operators can be found. 311 if (!isForRedeclaration()) { 312 switch (Name.getCXXOverloadedOperator()) { 313 case OO_New: 314 case OO_Delete: 315 case OO_Array_New: 316 case OO_Array_Delete: 317 SemaRef.DeclareGlobalNewDelete(); 318 break; 319 320 default: 321 break; 322 } 323 } 324} 325 326// Necessary because CXXBasePaths is not complete in Sema.h 327void LookupResult::deletePaths(CXXBasePaths *Paths) { 328 delete Paths; 329} 330 331/// Resolves the result kind of this lookup. 332void LookupResult::resolveKind() { 333 unsigned N = Decls.size(); 334 335 // Fast case: no possible ambiguity. 336 if (N == 0) { 337 assert(ResultKind == NotFound || ResultKind == NotFoundInCurrentInstantiation); 338 return; 339 } 340 341 // If there's a single decl, we need to examine it to decide what 342 // kind of lookup this is. 343 if (N == 1) { 344 if (isa<FunctionTemplateDecl>(*Decls.begin())) 345 ResultKind = FoundOverloaded; 346 else if (isa<UnresolvedUsingValueDecl>(*Decls.begin())) 347 ResultKind = FoundUnresolvedValue; 348 return; 349 } 350 351 // Don't do any extra resolution if we've already resolved as ambiguous. 352 if (ResultKind == Ambiguous) return; 353 354 llvm::SmallPtrSet<NamedDecl*, 16> Unique; 355 356 bool Ambiguous = false; 357 bool HasTag = false, HasFunction = false, HasNonFunction = false; 358 bool HasFunctionTemplate = false, HasUnresolved = false; 359 360 unsigned UniqueTagIndex = 0; 361 362 unsigned I = 0; 363 while (I < N) { 364 NamedDecl *D = Decls[I]->getUnderlyingDecl(); 365 D = cast<NamedDecl>(D->getCanonicalDecl()); 366 367 if (!Unique.insert(D)) { 368 // If it's not unique, pull something off the back (and 369 // continue at this index). 370 Decls[I] = Decls[--N]; 371 } else { 372 // Otherwise, do some decl type analysis and then continue. 373 374 if (isa<UnresolvedUsingValueDecl>(D)) { 375 HasUnresolved = true; 376 } else if (isa<TagDecl>(D)) { 377 if (HasTag) 378 Ambiguous = true; 379 UniqueTagIndex = I; 380 HasTag = true; 381 } else if (isa<FunctionTemplateDecl>(D)) { 382 HasFunction = true; 383 HasFunctionTemplate = true; 384 } else if (isa<FunctionDecl>(D)) { 385 HasFunction = true; 386 } else { 387 if (HasNonFunction) 388 Ambiguous = true; 389 HasNonFunction = true; 390 } 391 I++; 392 } 393 } 394 395 // C++ [basic.scope.hiding]p2: 396 // A class name or enumeration name can be hidden by the name of 397 // an object, function, or enumerator declared in the same 398 // scope. If a class or enumeration name and an object, function, 399 // or enumerator are declared in the same scope (in any order) 400 // with the same name, the class or enumeration name is hidden 401 // wherever the object, function, or enumerator name is visible. 402 // But it's still an error if there are distinct tag types found, 403 // even if they're not visible. (ref?) 404 if (HideTags && HasTag && !Ambiguous && 405 (HasFunction || HasNonFunction || HasUnresolved)) 406 Decls[UniqueTagIndex] = Decls[--N]; 407 408 Decls.set_size(N); 409 410 if (HasNonFunction && (HasFunction || HasUnresolved)) 411 Ambiguous = true; 412 413 if (Ambiguous) 414 setAmbiguous(LookupResult::AmbiguousReference); 415 else if (HasUnresolved) 416 ResultKind = LookupResult::FoundUnresolvedValue; 417 else if (N > 1 || HasFunctionTemplate) 418 ResultKind = LookupResult::FoundOverloaded; 419 else 420 ResultKind = LookupResult::Found; 421} 422 423void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) { 424 CXXBasePaths::const_paths_iterator I, E; 425 DeclContext::lookup_iterator DI, DE; 426 for (I = P.begin(), E = P.end(); I != E; ++I) 427 for (llvm::tie(DI,DE) = I->Decls; DI != DE; ++DI) 428 addDecl(*DI); 429} 430 431void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) { 432 Paths = new CXXBasePaths; 433 Paths->swap(P); 434 addDeclsFromBasePaths(*Paths); 435 resolveKind(); 436 setAmbiguous(AmbiguousBaseSubobjects); 437} 438 439void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) { 440 Paths = new CXXBasePaths; 441 Paths->swap(P); 442 addDeclsFromBasePaths(*Paths); 443 resolveKind(); 444 setAmbiguous(AmbiguousBaseSubobjectTypes); 445} 446 447void LookupResult::print(llvm::raw_ostream &Out) { 448 Out << Decls.size() << " result(s)"; 449 if (isAmbiguous()) Out << ", ambiguous"; 450 if (Paths) Out << ", base paths present"; 451 452 for (iterator I = begin(), E = end(); I != E; ++I) { 453 Out << "\n"; 454 (*I)->print(Out, 2); 455 } 456} 457 458/// \brief Lookup a builtin function, when name lookup would otherwise 459/// fail. 460static bool LookupBuiltin(Sema &S, LookupResult &R) { 461 Sema::LookupNameKind NameKind = R.getLookupKind(); 462 463 // If we didn't find a use of this identifier, and if the identifier 464 // corresponds to a compiler builtin, create the decl object for the builtin 465 // now, injecting it into translation unit scope, and return it. 466 if (NameKind == Sema::LookupOrdinaryName || 467 NameKind == Sema::LookupRedeclarationWithLinkage) { 468 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo(); 469 if (II) { 470 // If this is a builtin on this (or all) targets, create the decl. 471 if (unsigned BuiltinID = II->getBuiltinID()) { 472 // In C++, we don't have any predefined library functions like 473 // 'malloc'. Instead, we'll just error. 474 if (S.getLangOptions().CPlusPlus && 475 S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 476 return false; 477 478 NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 479 S.TUScope, R.isForRedeclaration(), 480 R.getNameLoc()); 481 if (D) 482 R.addDecl(D); 483 return (D != NULL); 484 } 485 } 486 } 487 488 return false; 489} 490 491// Adds all qualifying matches for a name within a decl context to the 492// given lookup result. Returns true if any matches were found. 493static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) { 494 bool Found = false; 495 496 DeclContext::lookup_const_iterator I, E; 497 for (llvm::tie(I, E) = DC->lookup(R.getLookupName()); I != E; ++I) { 498 NamedDecl *D = *I; 499 if (R.isAcceptableDecl(D)) { 500 R.addDecl(D); 501 Found = true; 502 } 503 } 504 505 if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R)) 506 return true; 507 508 if (R.getLookupName().getNameKind() 509 != DeclarationName::CXXConversionFunctionName || 510 R.getLookupName().getCXXNameType()->isDependentType() || 511 !isa<CXXRecordDecl>(DC)) 512 return Found; 513 514 // C++ [temp.mem]p6: 515 // A specialization of a conversion function template is not found by 516 // name lookup. Instead, any conversion function templates visible in the 517 // context of the use are considered. [...] 518 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC); 519 if (!Record->isDefinition()) 520 return Found; 521 522 const UnresolvedSetImpl *Unresolved = Record->getConversionFunctions(); 523 for (UnresolvedSetImpl::iterator U = Unresolved->begin(), 524 UEnd = Unresolved->end(); U != UEnd; ++U) { 525 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U); 526 if (!ConvTemplate) 527 continue; 528 529 // When we're performing lookup for the purposes of redeclaration, just 530 // add the conversion function template. When we deduce template 531 // arguments for specializations, we'll end up unifying the return 532 // type of the new declaration with the type of the function template. 533 if (R.isForRedeclaration()) { 534 R.addDecl(ConvTemplate); 535 Found = true; 536 continue; 537 } 538 539 // C++ [temp.mem]p6: 540 // [...] For each such operator, if argument deduction succeeds 541 // (14.9.2.3), the resulting specialization is used as if found by 542 // name lookup. 543 // 544 // When referencing a conversion function for any purpose other than 545 // a redeclaration (such that we'll be building an expression with the 546 // result), perform template argument deduction and place the 547 // specialization into the result set. We do this to avoid forcing all 548 // callers to perform special deduction for conversion functions. 549 Sema::TemplateDeductionInfo Info(R.getSema().Context, R.getNameLoc()); 550 FunctionDecl *Specialization = 0; 551 552 const FunctionProtoType *ConvProto 553 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>(); 554 assert(ConvProto && "Nonsensical conversion function template type"); 555 556 // Compute the type of the function that we would expect the conversion 557 // function to have, if it were to match the name given. 558 // FIXME: Calling convention! 559 FunctionType::ExtInfo ConvProtoInfo = ConvProto->getExtInfo(); 560 QualType ExpectedType 561 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(), 562 0, 0, ConvProto->isVariadic(), 563 ConvProto->getTypeQuals(), 564 false, false, 0, 0, 565 ConvProtoInfo.withCallingConv(CC_Default)); 566 567 // Perform template argument deduction against the type that we would 568 // expect the function to have. 569 if (R.getSema().DeduceTemplateArguments(ConvTemplate, 0, ExpectedType, 570 Specialization, Info) 571 == Sema::TDK_Success) { 572 R.addDecl(Specialization); 573 Found = true; 574 } 575 } 576 577 return Found; 578} 579 580// Performs C++ unqualified lookup into the given file context. 581static bool 582CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context, 583 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) { 584 585 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!"); 586 587 // Perform direct name lookup into the LookupCtx. 588 bool Found = LookupDirect(S, R, NS); 589 590 // Perform direct name lookup into the namespaces nominated by the 591 // using directives whose common ancestor is this namespace. 592 UnqualUsingDirectiveSet::const_iterator UI, UEnd; 593 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(NS); 594 595 for (; UI != UEnd; ++UI) 596 if (LookupDirect(S, R, UI->getNominatedNamespace())) 597 Found = true; 598 599 R.resolveKind(); 600 601 return Found; 602} 603 604static bool isNamespaceOrTranslationUnitScope(Scope *S) { 605 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) 606 return Ctx->isFileContext(); 607 return false; 608} 609 610// Find the next outer declaration context from this scope. This 611// routine actually returns the semantic outer context, which may 612// differ from the lexical context (encoded directly in the Scope 613// stack) when we are parsing a member of a class template. In this 614// case, the second element of the pair will be true, to indicate that 615// name lookup should continue searching in this semantic context when 616// it leaves the current template parameter scope. 617static std::pair<DeclContext *, bool> findOuterContext(Scope *S) { 618 DeclContext *DC = static_cast<DeclContext *>(S->getEntity()); 619 DeclContext *Lexical = 0; 620 for (Scope *OuterS = S->getParent(); OuterS; 621 OuterS = OuterS->getParent()) { 622 if (OuterS->getEntity()) { 623 Lexical = static_cast<DeclContext *>(OuterS->getEntity()); 624 break; 625 } 626 } 627 628 // C++ [temp.local]p8: 629 // In the definition of a member of a class template that appears 630 // outside of the namespace containing the class template 631 // definition, the name of a template-parameter hides the name of 632 // a member of this namespace. 633 // 634 // Example: 635 // 636 // namespace N { 637 // class C { }; 638 // 639 // template<class T> class B { 640 // void f(T); 641 // }; 642 // } 643 // 644 // template<class C> void N::B<C>::f(C) { 645 // C b; // C is the template parameter, not N::C 646 // } 647 // 648 // In this example, the lexical context we return is the 649 // TranslationUnit, while the semantic context is the namespace N. 650 if (!Lexical || !DC || !S->getParent() || 651 !S->getParent()->isTemplateParamScope()) 652 return std::make_pair(Lexical, false); 653 654 // Find the outermost template parameter scope. 655 // For the example, this is the scope for the template parameters of 656 // template<class C>. 657 Scope *OutermostTemplateScope = S->getParent(); 658 while (OutermostTemplateScope->getParent() && 659 OutermostTemplateScope->getParent()->isTemplateParamScope()) 660 OutermostTemplateScope = OutermostTemplateScope->getParent(); 661 662 // Find the namespace context in which the original scope occurs. In 663 // the example, this is namespace N. 664 DeclContext *Semantic = DC; 665 while (!Semantic->isFileContext()) 666 Semantic = Semantic->getParent(); 667 668 // Find the declaration context just outside of the template 669 // parameter scope. This is the context in which the template is 670 // being lexically declaration (a namespace context). In the 671 // example, this is the global scope. 672 if (Lexical->isFileContext() && !Lexical->Equals(Semantic) && 673 Lexical->Encloses(Semantic)) 674 return std::make_pair(Semantic, true); 675 676 return std::make_pair(Lexical, false); 677} 678 679bool Sema::CppLookupName(LookupResult &R, Scope *S) { 680 assert(getLangOptions().CPlusPlus && "Can perform only C++ lookup"); 681 682 DeclarationName Name = R.getLookupName(); 683 684 Scope *Initial = S; 685 IdentifierResolver::iterator 686 I = IdResolver.begin(Name), 687 IEnd = IdResolver.end(); 688 689 // First we lookup local scope. 690 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir] 691 // ...During unqualified name lookup (3.4.1), the names appear as if 692 // they were declared in the nearest enclosing namespace which contains 693 // both the using-directive and the nominated namespace. 694 // [Note: in this context, "contains" means "contains directly or 695 // indirectly". 696 // 697 // For example: 698 // namespace A { int i; } 699 // void foo() { 700 // int i; 701 // { 702 // using namespace A; 703 // ++i; // finds local 'i', A::i appears at global scope 704 // } 705 // } 706 // 707 DeclContext *OutsideOfTemplateParamDC = 0; 708 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) { 709 // Check whether the IdResolver has anything in this scope. 710 bool Found = false; 711 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) { 712 if (R.isAcceptableDecl(*I)) { 713 Found = true; 714 R.addDecl(*I); 715 } 716 } 717 if (Found) { 718 R.resolveKind(); 719 return true; 720 } 721 722 DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity()); 723 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC && 724 S->getParent() && !S->getParent()->isTemplateParamScope()) { 725 // We've just searched the last template parameter scope and 726 // found nothing, so look into the the contexts between the 727 // lexical and semantic declaration contexts returned by 728 // findOuterContext(). This implements the name lookup behavior 729 // of C++ [temp.local]p8. 730 Ctx = OutsideOfTemplateParamDC; 731 OutsideOfTemplateParamDC = 0; 732 } 733 734 if (Ctx) { 735 DeclContext *OuterCtx; 736 bool SearchAfterTemplateScope; 737 llvm::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S); 738 if (SearchAfterTemplateScope) 739 OutsideOfTemplateParamDC = OuterCtx; 740 741 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 742 // We do not directly look into transparent contexts, since 743 // those entities will be found in the nearest enclosing 744 // non-transparent context. 745 if (Ctx->isTransparentContext()) 746 continue; 747 748 // We do not look directly into function or method contexts, 749 // since all of the local variables and parameters of the 750 // function/method are present within the Scope. 751 if (Ctx->isFunctionOrMethod()) { 752 // If we have an Objective-C instance method, look for ivars 753 // in the corresponding interface. 754 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 755 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo()) 756 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) { 757 ObjCInterfaceDecl *ClassDeclared; 758 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable( 759 Name.getAsIdentifierInfo(), 760 ClassDeclared)) { 761 if (R.isAcceptableDecl(Ivar)) { 762 R.addDecl(Ivar); 763 R.resolveKind(); 764 return true; 765 } 766 } 767 } 768 } 769 770 continue; 771 } 772 773 // Perform qualified name lookup into this context. 774 // FIXME: In some cases, we know that every name that could be found by 775 // this qualified name lookup will also be on the identifier chain. For 776 // example, inside a class without any base classes, we never need to 777 // perform qualified lookup because all of the members are on top of the 778 // identifier chain. 779 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true)) 780 return true; 781 } 782 } 783 } 784 785 // Stop if we ran out of scopes. 786 // FIXME: This really, really shouldn't be happening. 787 if (!S) return false; 788 789 // Collect UsingDirectiveDecls in all scopes, and recursively all 790 // nominated namespaces by those using-directives. 791 // 792 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we 793 // don't build it for each lookup! 794 795 UnqualUsingDirectiveSet UDirs; 796 UDirs.visitScopeChain(Initial, S); 797 UDirs.done(); 798 799 // Lookup namespace scope, and global scope. 800 // Unqualified name lookup in C++ requires looking into scopes 801 // that aren't strictly lexical, and therefore we walk through the 802 // context as well as walking through the scopes. 803 804 for (; S; S = S->getParent()) { 805 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity()); 806 if (Ctx && Ctx->isTransparentContext()) 807 continue; 808 809 // Check whether the IdResolver has anything in this scope. 810 bool Found = false; 811 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) { 812 if (R.isAcceptableDecl(*I)) { 813 // We found something. Look for anything else in our scope 814 // with this same name and in an acceptable identifier 815 // namespace, so that we can construct an overload set if we 816 // need to. 817 Found = true; 818 R.addDecl(*I); 819 } 820 } 821 822 // If we have a context, and it's not a context stashed in the 823 // template parameter scope for an out-of-line definition, also 824 // look into that context. 825 if (Ctx && !(Found && S && S->isTemplateParamScope())) { 826 assert(Ctx->isFileContext() && 827 "We should have been looking only at file context here already."); 828 829 // Look into context considering using-directives. 830 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) 831 Found = true; 832 } 833 834 if (Found) { 835 R.resolveKind(); 836 return true; 837 } 838 839 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext()) 840 return false; 841 } 842 843 return !R.empty(); 844} 845 846/// @brief Perform unqualified name lookup starting from a given 847/// scope. 848/// 849/// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is 850/// used to find names within the current scope. For example, 'x' in 851/// @code 852/// int x; 853/// int f() { 854/// return x; // unqualified name look finds 'x' in the global scope 855/// } 856/// @endcode 857/// 858/// Different lookup criteria can find different names. For example, a 859/// particular scope can have both a struct and a function of the same 860/// name, and each can be found by certain lookup criteria. For more 861/// information about lookup criteria, see the documentation for the 862/// class LookupCriteria. 863/// 864/// @param S The scope from which unqualified name lookup will 865/// begin. If the lookup criteria permits, name lookup may also search 866/// in the parent scopes. 867/// 868/// @param Name The name of the entity that we are searching for. 869/// 870/// @param Loc If provided, the source location where we're performing 871/// name lookup. At present, this is only used to produce diagnostics when 872/// C library functions (like "malloc") are implicitly declared. 873/// 874/// @returns The result of name lookup, which includes zero or more 875/// declarations and possibly additional information used to diagnose 876/// ambiguities. 877bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) { 878 DeclarationName Name = R.getLookupName(); 879 if (!Name) return false; 880 881 LookupNameKind NameKind = R.getLookupKind(); 882 883 if (!getLangOptions().CPlusPlus) { 884 // Unqualified name lookup in C/Objective-C is purely lexical, so 885 // search in the declarations attached to the name. 886 887 if (NameKind == Sema::LookupRedeclarationWithLinkage) { 888 // Find the nearest non-transparent declaration scope. 889 while (!(S->getFlags() & Scope::DeclScope) || 890 (S->getEntity() && 891 static_cast<DeclContext *>(S->getEntity()) 892 ->isTransparentContext())) 893 S = S->getParent(); 894 } 895 896 unsigned IDNS = R.getIdentifierNamespace(); 897 898 // Scan up the scope chain looking for a decl that matches this 899 // identifier that is in the appropriate namespace. This search 900 // should not take long, as shadowing of names is uncommon, and 901 // deep shadowing is extremely uncommon. 902 bool LeftStartingScope = false; 903 904 for (IdentifierResolver::iterator I = IdResolver.begin(Name), 905 IEnd = IdResolver.end(); 906 I != IEnd; ++I) 907 if ((*I)->isInIdentifierNamespace(IDNS)) { 908 if (NameKind == LookupRedeclarationWithLinkage) { 909 // Determine whether this (or a previous) declaration is 910 // out-of-scope. 911 if (!LeftStartingScope && !S->isDeclScope(DeclPtrTy::make(*I))) 912 LeftStartingScope = true; 913 914 // If we found something outside of our starting scope that 915 // does not have linkage, skip it. 916 if (LeftStartingScope && !((*I)->hasLinkage())) 917 continue; 918 } 919 920 R.addDecl(*I); 921 922 if ((*I)->getAttr<OverloadableAttr>()) { 923 // If this declaration has the "overloadable" attribute, we 924 // might have a set of overloaded functions. 925 926 // Figure out what scope the identifier is in. 927 while (!(S->getFlags() & Scope::DeclScope) || 928 !S->isDeclScope(DeclPtrTy::make(*I))) 929 S = S->getParent(); 930 931 // Find the last declaration in this scope (with the same 932 // name, naturally). 933 IdentifierResolver::iterator LastI = I; 934 for (++LastI; LastI != IEnd; ++LastI) { 935 if (!S->isDeclScope(DeclPtrTy::make(*LastI))) 936 break; 937 R.addDecl(*LastI); 938 } 939 } 940 941 R.resolveKind(); 942 943 return true; 944 } 945 } else { 946 // Perform C++ unqualified name lookup. 947 if (CppLookupName(R, S)) 948 return true; 949 } 950 951 // If we didn't find a use of this identifier, and if the identifier 952 // corresponds to a compiler builtin, create the decl object for the builtin 953 // now, injecting it into translation unit scope, and return it. 954 if (AllowBuiltinCreation) 955 return LookupBuiltin(*this, R); 956 957 return false; 958} 959 960/// @brief Perform qualified name lookup in the namespaces nominated by 961/// using directives by the given context. 962/// 963/// C++98 [namespace.qual]p2: 964/// Given X::m (where X is a user-declared namespace), or given ::m 965/// (where X is the global namespace), let S be the set of all 966/// declarations of m in X and in the transitive closure of all 967/// namespaces nominated by using-directives in X and its used 968/// namespaces, except that using-directives are ignored in any 969/// namespace, including X, directly containing one or more 970/// declarations of m. No namespace is searched more than once in 971/// the lookup of a name. If S is the empty set, the program is 972/// ill-formed. Otherwise, if S has exactly one member, or if the 973/// context of the reference is a using-declaration 974/// (namespace.udecl), S is the required set of declarations of 975/// m. Otherwise if the use of m is not one that allows a unique 976/// declaration to be chosen from S, the program is ill-formed. 977/// C++98 [namespace.qual]p5: 978/// During the lookup of a qualified namespace member name, if the 979/// lookup finds more than one declaration of the member, and if one 980/// declaration introduces a class name or enumeration name and the 981/// other declarations either introduce the same object, the same 982/// enumerator or a set of functions, the non-type name hides the 983/// class or enumeration name if and only if the declarations are 984/// from the same namespace; otherwise (the declarations are from 985/// different namespaces), the program is ill-formed. 986static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R, 987 DeclContext *StartDC) { 988 assert(StartDC->isFileContext() && "start context is not a file context"); 989 990 DeclContext::udir_iterator I = StartDC->using_directives_begin(); 991 DeclContext::udir_iterator E = StartDC->using_directives_end(); 992 993 if (I == E) return false; 994 995 // We have at least added all these contexts to the queue. 996 llvm::DenseSet<DeclContext*> Visited; 997 Visited.insert(StartDC); 998 999 // We have not yet looked into these namespaces, much less added 1000 // their "using-children" to the queue. 1001 llvm::SmallVector<NamespaceDecl*, 8> Queue; 1002 1003 // We have already looked into the initial namespace; seed the queue 1004 // with its using-children. 1005 for (; I != E; ++I) { 1006 NamespaceDecl *ND = (*I)->getNominatedNamespace()->getOriginalNamespace(); 1007 if (Visited.insert(ND).second) 1008 Queue.push_back(ND); 1009 } 1010 1011 // The easiest way to implement the restriction in [namespace.qual]p5 1012 // is to check whether any of the individual results found a tag 1013 // and, if so, to declare an ambiguity if the final result is not 1014 // a tag. 1015 bool FoundTag = false; 1016 bool FoundNonTag = false; 1017 1018 LookupResult LocalR(LookupResult::Temporary, R); 1019 1020 bool Found = false; 1021 while (!Queue.empty()) { 1022 NamespaceDecl *ND = Queue.back(); 1023 Queue.pop_back(); 1024 1025 // We go through some convolutions here to avoid copying results 1026 // between LookupResults. 1027 bool UseLocal = !R.empty(); 1028 LookupResult &DirectR = UseLocal ? LocalR : R; 1029 bool FoundDirect = LookupDirect(S, DirectR, ND); 1030 1031 if (FoundDirect) { 1032 // First do any local hiding. 1033 DirectR.resolveKind(); 1034 1035 // If the local result is a tag, remember that. 1036 if (DirectR.isSingleTagDecl()) 1037 FoundTag = true; 1038 else 1039 FoundNonTag = true; 1040 1041 // Append the local results to the total results if necessary. 1042 if (UseLocal) { 1043 R.addAllDecls(LocalR); 1044 LocalR.clear(); 1045 } 1046 } 1047 1048 // If we find names in this namespace, ignore its using directives. 1049 if (FoundDirect) { 1050 Found = true; 1051 continue; 1052 } 1053 1054 for (llvm::tie(I,E) = ND->getUsingDirectives(); I != E; ++I) { 1055 NamespaceDecl *Nom = (*I)->getNominatedNamespace(); 1056 if (Visited.insert(Nom).second) 1057 Queue.push_back(Nom); 1058 } 1059 } 1060 1061 if (Found) { 1062 if (FoundTag && FoundNonTag) 1063 R.setAmbiguousQualifiedTagHiding(); 1064 else 1065 R.resolveKind(); 1066 } 1067 1068 return Found; 1069} 1070 1071/// \brief Perform qualified name lookup into a given context. 1072/// 1073/// Qualified name lookup (C++ [basic.lookup.qual]) is used to find 1074/// names when the context of those names is explicit specified, e.g., 1075/// "std::vector" or "x->member", or as part of unqualified name lookup. 1076/// 1077/// Different lookup criteria can find different names. For example, a 1078/// particular scope can have both a struct and a function of the same 1079/// name, and each can be found by certain lookup criteria. For more 1080/// information about lookup criteria, see the documentation for the 1081/// class LookupCriteria. 1082/// 1083/// \param R captures both the lookup criteria and any lookup results found. 1084/// 1085/// \param LookupCtx The context in which qualified name lookup will 1086/// search. If the lookup criteria permits, name lookup may also search 1087/// in the parent contexts or (for C++ classes) base classes. 1088/// 1089/// \param InUnqualifiedLookup true if this is qualified name lookup that 1090/// occurs as part of unqualified name lookup. 1091/// 1092/// \returns true if lookup succeeded, false if it failed. 1093bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 1094 bool InUnqualifiedLookup) { 1095 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context"); 1096 1097 if (!R.getLookupName()) 1098 return false; 1099 1100 // Make sure that the declaration context is complete. 1101 assert((!isa<TagDecl>(LookupCtx) || 1102 LookupCtx->isDependentContext() || 1103 cast<TagDecl>(LookupCtx)->isDefinition() || 1104 Context.getTypeDeclType(cast<TagDecl>(LookupCtx))->getAs<TagType>() 1105 ->isBeingDefined()) && 1106 "Declaration context must already be complete!"); 1107 1108 // Perform qualified name lookup into the LookupCtx. 1109 if (LookupDirect(*this, R, LookupCtx)) { 1110 R.resolveKind(); 1111 if (isa<CXXRecordDecl>(LookupCtx)) 1112 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx)); 1113 return true; 1114 } 1115 1116 // Don't descend into implied contexts for redeclarations. 1117 // C++98 [namespace.qual]p6: 1118 // In a declaration for a namespace member in which the 1119 // declarator-id is a qualified-id, given that the qualified-id 1120 // for the namespace member has the form 1121 // nested-name-specifier unqualified-id 1122 // the unqualified-id shall name a member of the namespace 1123 // designated by the nested-name-specifier. 1124 // See also [class.mfct]p5 and [class.static.data]p2. 1125 if (R.isForRedeclaration()) 1126 return false; 1127 1128 // If this is a namespace, look it up in the implied namespaces. 1129 if (LookupCtx->isFileContext()) 1130 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx); 1131 1132 // If this isn't a C++ class, we aren't allowed to look into base 1133 // classes, we're done. 1134 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx); 1135 if (!LookupRec) 1136 return false; 1137 1138 // If we're performing qualified name lookup into a dependent class, 1139 // then we are actually looking into a current instantiation. If we have any 1140 // dependent base classes, then we either have to delay lookup until 1141 // template instantiation time (at which point all bases will be available) 1142 // or we have to fail. 1143 if (!InUnqualifiedLookup && LookupRec->isDependentContext() && 1144 LookupRec->hasAnyDependentBases()) { 1145 R.setNotFoundInCurrentInstantiation(); 1146 return false; 1147 } 1148 1149 // Perform lookup into our base classes. 1150 CXXBasePaths Paths; 1151 Paths.setOrigin(LookupRec); 1152 1153 // Look for this member in our base classes 1154 CXXRecordDecl::BaseMatchesCallback *BaseCallback = 0; 1155 switch (R.getLookupKind()) { 1156 case LookupOrdinaryName: 1157 case LookupMemberName: 1158 case LookupRedeclarationWithLinkage: 1159 BaseCallback = &CXXRecordDecl::FindOrdinaryMember; 1160 break; 1161 1162 case LookupTagName: 1163 BaseCallback = &CXXRecordDecl::FindTagMember; 1164 break; 1165 1166 case LookupUsingDeclName: 1167 // This lookup is for redeclarations only. 1168 1169 case LookupOperatorName: 1170 case LookupNamespaceName: 1171 case LookupObjCProtocolName: 1172 case LookupObjCImplementationName: 1173 // These lookups will never find a member in a C++ class (or base class). 1174 return false; 1175 1176 case LookupNestedNameSpecifierName: 1177 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember; 1178 break; 1179 } 1180 1181 if (!LookupRec->lookupInBases(BaseCallback, 1182 R.getLookupName().getAsOpaquePtr(), Paths)) 1183 return false; 1184 1185 R.setNamingClass(LookupRec); 1186 1187 // C++ [class.member.lookup]p2: 1188 // [...] If the resulting set of declarations are not all from 1189 // sub-objects of the same type, or the set has a nonstatic member 1190 // and includes members from distinct sub-objects, there is an 1191 // ambiguity and the program is ill-formed. Otherwise that set is 1192 // the result of the lookup. 1193 // FIXME: support using declarations! 1194 QualType SubobjectType; 1195 int SubobjectNumber = 0; 1196 AccessSpecifier SubobjectAccess = AS_none; 1197 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); 1198 Path != PathEnd; ++Path) { 1199 const CXXBasePathElement &PathElement = Path->back(); 1200 1201 // Pick the best (i.e. most permissive i.e. numerically lowest) access 1202 // across all paths. 1203 SubobjectAccess = std::min(SubobjectAccess, Path->Access); 1204 1205 // Determine whether we're looking at a distinct sub-object or not. 1206 if (SubobjectType.isNull()) { 1207 // This is the first subobject we've looked at. Record its type. 1208 SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); 1209 SubobjectNumber = PathElement.SubobjectNumber; 1210 } else if (SubobjectType 1211 != Context.getCanonicalType(PathElement.Base->getType())) { 1212 // We found members of the given name in two subobjects of 1213 // different types. This lookup is ambiguous. 1214 R.setAmbiguousBaseSubobjectTypes(Paths); 1215 return true; 1216 } else if (SubobjectNumber != PathElement.SubobjectNumber) { 1217 // We have a different subobject of the same type. 1218 1219 // C++ [class.member.lookup]p5: 1220 // A static member, a nested type or an enumerator defined in 1221 // a base class T can unambiguously be found even if an object 1222 // has more than one base class subobject of type T. 1223 Decl *FirstDecl = *Path->Decls.first; 1224 if (isa<VarDecl>(FirstDecl) || 1225 isa<TypeDecl>(FirstDecl) || 1226 isa<EnumConstantDecl>(FirstDecl)) 1227 continue; 1228 1229 if (isa<CXXMethodDecl>(FirstDecl)) { 1230 // Determine whether all of the methods are static. 1231 bool AllMethodsAreStatic = true; 1232 for (DeclContext::lookup_iterator Func = Path->Decls.first; 1233 Func != Path->Decls.second; ++Func) { 1234 if (!isa<CXXMethodDecl>(*Func)) { 1235 assert(isa<TagDecl>(*Func) && "Non-function must be a tag decl"); 1236 break; 1237 } 1238 1239 if (!cast<CXXMethodDecl>(*Func)->isStatic()) { 1240 AllMethodsAreStatic = false; 1241 break; 1242 } 1243 } 1244 1245 if (AllMethodsAreStatic) 1246 continue; 1247 } 1248 1249 // We have found a nonstatic member name in multiple, distinct 1250 // subobjects. Name lookup is ambiguous. 1251 R.setAmbiguousBaseSubobjects(Paths); 1252 return true; 1253 } 1254 } 1255 1256 // Lookup in a base class succeeded; return these results. 1257 1258 DeclContext::lookup_iterator I, E; 1259 for (llvm::tie(I,E) = Paths.front().Decls; I != E; ++I) { 1260 NamedDecl *D = *I; 1261 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess, 1262 D->getAccess()); 1263 R.addDecl(D, AS); 1264 } 1265 R.resolveKind(); 1266 return true; 1267} 1268 1269/// @brief Performs name lookup for a name that was parsed in the 1270/// source code, and may contain a C++ scope specifier. 1271/// 1272/// This routine is a convenience routine meant to be called from 1273/// contexts that receive a name and an optional C++ scope specifier 1274/// (e.g., "N::M::x"). It will then perform either qualified or 1275/// unqualified name lookup (with LookupQualifiedName or LookupName, 1276/// respectively) on the given name and return those results. 1277/// 1278/// @param S The scope from which unqualified name lookup will 1279/// begin. 1280/// 1281/// @param SS An optional C++ scope-specifier, e.g., "::N::M". 1282/// 1283/// @param Name The name of the entity that name lookup will 1284/// search for. 1285/// 1286/// @param Loc If provided, the source location where we're performing 1287/// name lookup. At present, this is only used to produce diagnostics when 1288/// C library functions (like "malloc") are implicitly declared. 1289/// 1290/// @param EnteringContext Indicates whether we are going to enter the 1291/// context of the scope-specifier SS (if present). 1292/// 1293/// @returns True if any decls were found (but possibly ambiguous) 1294bool Sema::LookupParsedName(LookupResult &R, Scope *S, const CXXScopeSpec *SS, 1295 bool AllowBuiltinCreation, bool EnteringContext) { 1296 if (SS && SS->isInvalid()) { 1297 // When the scope specifier is invalid, don't even look for 1298 // anything. 1299 return false; 1300 } 1301 1302 if (SS && SS->isSet()) { 1303 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { 1304 // We have resolved the scope specifier to a particular declaration 1305 // contex, and will perform name lookup in that context. 1306 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS)) 1307 return false; 1308 1309 R.setContextRange(SS->getRange()); 1310 1311 return LookupQualifiedName(R, DC); 1312 } 1313 1314 // We could not resolve the scope specified to a specific declaration 1315 // context, which means that SS refers to an unknown specialization. 1316 // Name lookup can't find anything in this case. 1317 return false; 1318 } 1319 1320 // Perform unqualified name lookup starting in the given scope. 1321 return LookupName(R, S, AllowBuiltinCreation); 1322} 1323 1324 1325/// @brief Produce a diagnostic describing the ambiguity that resulted 1326/// from name lookup. 1327/// 1328/// @param Result The ambiguous name lookup result. 1329/// 1330/// @param Name The name of the entity that name lookup was 1331/// searching for. 1332/// 1333/// @param NameLoc The location of the name within the source code. 1334/// 1335/// @param LookupRange A source range that provides more 1336/// source-location information concerning the lookup itself. For 1337/// example, this range might highlight a nested-name-specifier that 1338/// precedes the name. 1339/// 1340/// @returns true 1341bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result) { 1342 assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); 1343 1344 DeclarationName Name = Result.getLookupName(); 1345 SourceLocation NameLoc = Result.getNameLoc(); 1346 SourceRange LookupRange = Result.getContextRange(); 1347 1348 switch (Result.getAmbiguityKind()) { 1349 case LookupResult::AmbiguousBaseSubobjects: { 1350 CXXBasePaths *Paths = Result.getBasePaths(); 1351 QualType SubobjectType = Paths->front().back().Base->getType(); 1352 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) 1353 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) 1354 << LookupRange; 1355 1356 DeclContext::lookup_iterator Found = Paths->front().Decls.first; 1357 while (isa<CXXMethodDecl>(*Found) && 1358 cast<CXXMethodDecl>(*Found)->isStatic()) 1359 ++Found; 1360 1361 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); 1362 1363 return true; 1364 } 1365 1366 case LookupResult::AmbiguousBaseSubobjectTypes: { 1367 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) 1368 << Name << LookupRange; 1369 1370 CXXBasePaths *Paths = Result.getBasePaths(); 1371 std::set<Decl *> DeclsPrinted; 1372 for (CXXBasePaths::paths_iterator Path = Paths->begin(), 1373 PathEnd = Paths->end(); 1374 Path != PathEnd; ++Path) { 1375 Decl *D = *Path->Decls.first; 1376 if (DeclsPrinted.insert(D).second) 1377 Diag(D->getLocation(), diag::note_ambiguous_member_found); 1378 } 1379 1380 return true; 1381 } 1382 1383 case LookupResult::AmbiguousTagHiding: { 1384 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange; 1385 1386 llvm::SmallPtrSet<NamedDecl*,8> TagDecls; 1387 1388 LookupResult::iterator DI, DE = Result.end(); 1389 for (DI = Result.begin(); DI != DE; ++DI) 1390 if (TagDecl *TD = dyn_cast<TagDecl>(*DI)) { 1391 TagDecls.insert(TD); 1392 Diag(TD->getLocation(), diag::note_hidden_tag); 1393 } 1394 1395 for (DI = Result.begin(); DI != DE; ++DI) 1396 if (!isa<TagDecl>(*DI)) 1397 Diag((*DI)->getLocation(), diag::note_hiding_object); 1398 1399 // For recovery purposes, go ahead and implement the hiding. 1400 LookupResult::Filter F = Result.makeFilter(); 1401 while (F.hasNext()) { 1402 if (TagDecls.count(F.next())) 1403 F.erase(); 1404 } 1405 F.done(); 1406 1407 return true; 1408 } 1409 1410 case LookupResult::AmbiguousReference: { 1411 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; 1412 1413 LookupResult::iterator DI = Result.begin(), DE = Result.end(); 1414 for (; DI != DE; ++DI) 1415 Diag((*DI)->getLocation(), diag::note_ambiguous_candidate) << *DI; 1416 1417 return true; 1418 } 1419 } 1420 1421 llvm_unreachable("unknown ambiguity kind"); 1422 return true; 1423} 1424 1425static void 1426addAssociatedClassesAndNamespaces(QualType T, 1427 ASTContext &Context, 1428 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1429 Sema::AssociatedClassSet &AssociatedClasses); 1430 1431static void CollectNamespace(Sema::AssociatedNamespaceSet &Namespaces, 1432 DeclContext *Ctx) { 1433 if (Ctx->isFileContext()) 1434 Namespaces.insert(Ctx); 1435} 1436 1437// \brief Add the associated classes and namespaces for argument-dependent 1438// lookup that involves a template argument (C++ [basic.lookup.koenig]p2). 1439static void 1440addAssociatedClassesAndNamespaces(const TemplateArgument &Arg, 1441 ASTContext &Context, 1442 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1443 Sema::AssociatedClassSet &AssociatedClasses) { 1444 // C++ [basic.lookup.koenig]p2, last bullet: 1445 // -- [...] ; 1446 switch (Arg.getKind()) { 1447 case TemplateArgument::Null: 1448 break; 1449 1450 case TemplateArgument::Type: 1451 // [...] the namespaces and classes associated with the types of the 1452 // template arguments provided for template type parameters (excluding 1453 // template template parameters) 1454 addAssociatedClassesAndNamespaces(Arg.getAsType(), Context, 1455 AssociatedNamespaces, 1456 AssociatedClasses); 1457 break; 1458 1459 case TemplateArgument::Template: { 1460 // [...] the namespaces in which any template template arguments are 1461 // defined; and the classes in which any member templates used as 1462 // template template arguments are defined. 1463 TemplateName Template = Arg.getAsTemplate(); 1464 if (ClassTemplateDecl *ClassTemplate 1465 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) { 1466 DeclContext *Ctx = ClassTemplate->getDeclContext(); 1467 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1468 AssociatedClasses.insert(EnclosingClass); 1469 // Add the associated namespace for this class. 1470 while (Ctx->isRecord()) 1471 Ctx = Ctx->getParent(); 1472 CollectNamespace(AssociatedNamespaces, Ctx); 1473 } 1474 break; 1475 } 1476 1477 case TemplateArgument::Declaration: 1478 case TemplateArgument::Integral: 1479 case TemplateArgument::Expression: 1480 // [Note: non-type template arguments do not contribute to the set of 1481 // associated namespaces. ] 1482 break; 1483 1484 case TemplateArgument::Pack: 1485 for (TemplateArgument::pack_iterator P = Arg.pack_begin(), 1486 PEnd = Arg.pack_end(); 1487 P != PEnd; ++P) 1488 addAssociatedClassesAndNamespaces(*P, Context, 1489 AssociatedNamespaces, 1490 AssociatedClasses); 1491 break; 1492 } 1493} 1494 1495// \brief Add the associated classes and namespaces for 1496// argument-dependent lookup with an argument of class type 1497// (C++ [basic.lookup.koenig]p2). 1498static void 1499addAssociatedClassesAndNamespaces(CXXRecordDecl *Class, 1500 ASTContext &Context, 1501 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1502 Sema::AssociatedClassSet &AssociatedClasses) { 1503 // C++ [basic.lookup.koenig]p2: 1504 // [...] 1505 // -- If T is a class type (including unions), its associated 1506 // classes are: the class itself; the class of which it is a 1507 // member, if any; and its direct and indirect base 1508 // classes. Its associated namespaces are the namespaces in 1509 // which its associated classes are defined. 1510 1511 // Add the class of which it is a member, if any. 1512 DeclContext *Ctx = Class->getDeclContext(); 1513 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1514 AssociatedClasses.insert(EnclosingClass); 1515 // Add the associated namespace for this class. 1516 while (Ctx->isRecord()) 1517 Ctx = Ctx->getParent(); 1518 CollectNamespace(AssociatedNamespaces, Ctx); 1519 1520 // Add the class itself. If we've already seen this class, we don't 1521 // need to visit base classes. 1522 if (!AssociatedClasses.insert(Class)) 1523 return; 1524 1525 // -- If T is a template-id, its associated namespaces and classes are 1526 // the namespace in which the template is defined; for member 1527 // templates, the member template’s class; the namespaces and classes 1528 // associated with the types of the template arguments provided for 1529 // template type parameters (excluding template template parameters); the 1530 // namespaces in which any template template arguments are defined; and 1531 // the classes in which any member templates used as template template 1532 // arguments are defined. [Note: non-type template arguments do not 1533 // contribute to the set of associated namespaces. ] 1534 if (ClassTemplateSpecializationDecl *Spec 1535 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) { 1536 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); 1537 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1538 AssociatedClasses.insert(EnclosingClass); 1539 // Add the associated namespace for this class. 1540 while (Ctx->isRecord()) 1541 Ctx = Ctx->getParent(); 1542 CollectNamespace(AssociatedNamespaces, Ctx); 1543 1544 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); 1545 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 1546 addAssociatedClassesAndNamespaces(TemplateArgs[I], Context, 1547 AssociatedNamespaces, 1548 AssociatedClasses); 1549 } 1550 1551 // Only recurse into base classes for complete types. 1552 if (!Class->hasDefinition()) { 1553 // FIXME: we might need to instantiate templates here 1554 return; 1555 } 1556 1557 // Add direct and indirect base classes along with their associated 1558 // namespaces. 1559 llvm::SmallVector<CXXRecordDecl *, 32> Bases; 1560 Bases.push_back(Class); 1561 while (!Bases.empty()) { 1562 // Pop this class off the stack. 1563 Class = Bases.back(); 1564 Bases.pop_back(); 1565 1566 // Visit the base classes. 1567 for (CXXRecordDecl::base_class_iterator Base = Class->bases_begin(), 1568 BaseEnd = Class->bases_end(); 1569 Base != BaseEnd; ++Base) { 1570 const RecordType *BaseType = Base->getType()->getAs<RecordType>(); 1571 // In dependent contexts, we do ADL twice, and the first time around, 1572 // the base type might be a dependent TemplateSpecializationType, or a 1573 // TemplateTypeParmType. If that happens, simply ignore it. 1574 // FIXME: If we want to support export, we probably need to add the 1575 // namespace of the template in a TemplateSpecializationType, or even 1576 // the classes and namespaces of known non-dependent arguments. 1577 if (!BaseType) 1578 continue; 1579 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 1580 if (AssociatedClasses.insert(BaseDecl)) { 1581 // Find the associated namespace for this base class. 1582 DeclContext *BaseCtx = BaseDecl->getDeclContext(); 1583 while (BaseCtx->isRecord()) 1584 BaseCtx = BaseCtx->getParent(); 1585 CollectNamespace(AssociatedNamespaces, 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(QualType T, 1600 ASTContext &Context, 1601 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1602 Sema::AssociatedClassSet &AssociatedClasses) { 1603 // C++ [basic.lookup.koenig]p2: 1604 // 1605 // For each argument type T in the function call, there is a set 1606 // of zero or more associated namespaces and a set of zero or more 1607 // associated classes to be considered. The sets of namespaces and 1608 // classes is determined entirely by the types of the function 1609 // arguments (and the namespace of any template template 1610 // argument). Typedef names and using-declarations used to specify 1611 // the types do not contribute to this set. The sets of namespaces 1612 // and classes are determined in the following way: 1613 T = Context.getCanonicalType(T).getUnqualifiedType(); 1614 1615 // -- If T is a pointer to U or an array of U, its associated 1616 // namespaces and classes are those associated with U. 1617 // 1618 // We handle this by unwrapping pointer and array types immediately, 1619 // to avoid unnecessary recursion. 1620 while (true) { 1621 if (const PointerType *Ptr = T->getAs<PointerType>()) 1622 T = Ptr->getPointeeType(); 1623 else if (const ArrayType *Ptr = Context.getAsArrayType(T)) 1624 T = Ptr->getElementType(); 1625 else 1626 break; 1627 } 1628 1629 // -- If T is a fundamental type, its associated sets of 1630 // namespaces and classes are both empty. 1631 if (T->getAs<BuiltinType>()) 1632 return; 1633 1634 // -- If T is a class type (including unions), its associated 1635 // classes are: the class itself; the class of which it is a 1636 // member, if any; and its direct and indirect base 1637 // classes. Its associated namespaces are the namespaces in 1638 // which its associated classes are defined. 1639 if (const RecordType *ClassType = T->getAs<RecordType>()) 1640 if (CXXRecordDecl *ClassDecl 1641 = dyn_cast<CXXRecordDecl>(ClassType->getDecl())) { 1642 addAssociatedClassesAndNamespaces(ClassDecl, Context, 1643 AssociatedNamespaces, 1644 AssociatedClasses); 1645 return; 1646 } 1647 1648 // -- If T is an enumeration type, its associated namespace is 1649 // the namespace in which it is defined. If it is class 1650 // member, its associated class is the member’s class; else 1651 // it has no associated class. 1652 if (const EnumType *EnumT = T->getAs<EnumType>()) { 1653 EnumDecl *Enum = EnumT->getDecl(); 1654 1655 DeclContext *Ctx = Enum->getDeclContext(); 1656 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1657 AssociatedClasses.insert(EnclosingClass); 1658 1659 // Add the associated namespace for this class. 1660 while (Ctx->isRecord()) 1661 Ctx = Ctx->getParent(); 1662 CollectNamespace(AssociatedNamespaces, Ctx); 1663 1664 return; 1665 } 1666 1667 // -- If T is a function type, its associated namespaces and 1668 // classes are those associated with the function parameter 1669 // types and those associated with the return type. 1670 if (const FunctionType *FnType = T->getAs<FunctionType>()) { 1671 // Return type 1672 addAssociatedClassesAndNamespaces(FnType->getResultType(), 1673 Context, 1674 AssociatedNamespaces, AssociatedClasses); 1675 1676 const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FnType); 1677 if (!Proto) 1678 return; 1679 1680 // Argument types 1681 for (FunctionProtoType::arg_type_iterator Arg = Proto->arg_type_begin(), 1682 ArgEnd = Proto->arg_type_end(); 1683 Arg != ArgEnd; ++Arg) 1684 addAssociatedClassesAndNamespaces(*Arg, Context, 1685 AssociatedNamespaces, AssociatedClasses); 1686 1687 return; 1688 } 1689 1690 // -- If T is a pointer to a member function of a class X, its 1691 // associated namespaces and classes are those associated 1692 // with the function parameter types and return type, 1693 // together with those associated with X. 1694 // 1695 // -- If T is a pointer to a data member of class X, its 1696 // associated namespaces and classes are those associated 1697 // with the member type together with those associated with 1698 // X. 1699 if (const MemberPointerType *MemberPtr = T->getAs<MemberPointerType>()) { 1700 // Handle the type that the pointer to member points to. 1701 addAssociatedClassesAndNamespaces(MemberPtr->getPointeeType(), 1702 Context, 1703 AssociatedNamespaces, 1704 AssociatedClasses); 1705 1706 // Handle the class type into which this points. 1707 if (const RecordType *Class = MemberPtr->getClass()->getAs<RecordType>()) 1708 addAssociatedClassesAndNamespaces(cast<CXXRecordDecl>(Class->getDecl()), 1709 Context, 1710 AssociatedNamespaces, 1711 AssociatedClasses); 1712 1713 return; 1714 } 1715 1716 // FIXME: What about block pointers? 1717 // FIXME: What about Objective-C message sends? 1718} 1719 1720/// \brief Find the associated classes and namespaces for 1721/// argument-dependent lookup for a call with the given set of 1722/// arguments. 1723/// 1724/// This routine computes the sets of associated classes and associated 1725/// namespaces searched by argument-dependent lookup 1726/// (C++ [basic.lookup.argdep]) for a given set of arguments. 1727void 1728Sema::FindAssociatedClassesAndNamespaces(Expr **Args, unsigned NumArgs, 1729 AssociatedNamespaceSet &AssociatedNamespaces, 1730 AssociatedClassSet &AssociatedClasses) { 1731 AssociatedNamespaces.clear(); 1732 AssociatedClasses.clear(); 1733 1734 // C++ [basic.lookup.koenig]p2: 1735 // For each argument type T in the function call, there is a set 1736 // of zero or more associated namespaces and a set of zero or more 1737 // associated classes to be considered. The sets of namespaces and 1738 // classes is determined entirely by the types of the function 1739 // arguments (and the namespace of any template template 1740 // argument). 1741 for (unsigned ArgIdx = 0; ArgIdx != NumArgs; ++ArgIdx) { 1742 Expr *Arg = Args[ArgIdx]; 1743 1744 if (Arg->getType() != Context.OverloadTy) { 1745 addAssociatedClassesAndNamespaces(Arg->getType(), Context, 1746 AssociatedNamespaces, 1747 AssociatedClasses); 1748 continue; 1749 } 1750 1751 // [...] In addition, if the argument is the name or address of a 1752 // set of overloaded functions and/or function templates, its 1753 // associated classes and namespaces are the union of those 1754 // associated with each of the members of the set: the namespace 1755 // in which the function or function template is defined and the 1756 // classes and namespaces associated with its (non-dependent) 1757 // parameter types and return type. 1758 Arg = Arg->IgnoreParens(); 1759 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg)) 1760 if (unaryOp->getOpcode() == UnaryOperator::AddrOf) 1761 Arg = unaryOp->getSubExpr(); 1762 1763 // TODO: avoid the copies. This should be easy when the cases 1764 // share a storage implementation. 1765 llvm::SmallVector<NamedDecl*, 8> Functions; 1766 1767 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg)) 1768 Functions.append(ULE->decls_begin(), ULE->decls_end()); 1769 else 1770 continue; 1771 1772 for (llvm::SmallVectorImpl<NamedDecl*>::iterator I = Functions.begin(), 1773 E = Functions.end(); I != E; ++I) { 1774 // Look through any using declarations to find the underlying function. 1775 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 1776 1777 FunctionDecl *FDecl = dyn_cast<FunctionDecl>(Fn); 1778 if (!FDecl) 1779 FDecl = cast<FunctionTemplateDecl>(Fn)->getTemplatedDecl(); 1780 1781 // Add the classes and namespaces associated with the parameter 1782 // types and return type of this function. 1783 addAssociatedClassesAndNamespaces(FDecl->getType(), Context, 1784 AssociatedNamespaces, 1785 AssociatedClasses); 1786 } 1787 } 1788} 1789 1790/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is 1791/// an acceptable non-member overloaded operator for a call whose 1792/// arguments have types T1 (and, if non-empty, T2). This routine 1793/// implements the check in C++ [over.match.oper]p3b2 concerning 1794/// enumeration types. 1795static bool 1796IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn, 1797 QualType T1, QualType T2, 1798 ASTContext &Context) { 1799 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType())) 1800 return true; 1801 1802 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType())) 1803 return true; 1804 1805 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>(); 1806 if (Proto->getNumArgs() < 1) 1807 return false; 1808 1809 if (T1->isEnumeralType()) { 1810 QualType ArgType = Proto->getArgType(0).getNonReferenceType(); 1811 if (Context.hasSameUnqualifiedType(T1, ArgType)) 1812 return true; 1813 } 1814 1815 if (Proto->getNumArgs() < 2) 1816 return false; 1817 1818 if (!T2.isNull() && T2->isEnumeralType()) { 1819 QualType ArgType = Proto->getArgType(1).getNonReferenceType(); 1820 if (Context.hasSameUnqualifiedType(T2, ArgType)) 1821 return true; 1822 } 1823 1824 return false; 1825} 1826 1827NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name, 1828 LookupNameKind NameKind, 1829 RedeclarationKind Redecl) { 1830 LookupResult R(*this, Name, SourceLocation(), NameKind, Redecl); 1831 LookupName(R, S); 1832 return R.getAsSingle<NamedDecl>(); 1833} 1834 1835/// \brief Find the protocol with the given name, if any. 1836ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II) { 1837 Decl *D = LookupSingleName(TUScope, II, LookupObjCProtocolName); 1838 return cast_or_null<ObjCProtocolDecl>(D); 1839} 1840 1841void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, 1842 QualType T1, QualType T2, 1843 UnresolvedSetImpl &Functions) { 1844 // C++ [over.match.oper]p3: 1845 // -- The set of non-member candidates is the result of the 1846 // unqualified lookup of operator@ in the context of the 1847 // expression according to the usual rules for name lookup in 1848 // unqualified function calls (3.4.2) except that all member 1849 // functions are ignored. However, if no operand has a class 1850 // type, only those non-member functions in the lookup set 1851 // that have a first parameter of type T1 or "reference to 1852 // (possibly cv-qualified) T1", when T1 is an enumeration 1853 // type, or (if there is a right operand) a second parameter 1854 // of type T2 or "reference to (possibly cv-qualified) T2", 1855 // when T2 is an enumeration type, are candidate functions. 1856 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 1857 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName); 1858 LookupName(Operators, S); 1859 1860 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); 1861 1862 if (Operators.empty()) 1863 return; 1864 1865 for (LookupResult::iterator Op = Operators.begin(), OpEnd = Operators.end(); 1866 Op != OpEnd; ++Op) { 1867 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Op)) { 1868 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context)) 1869 Functions.addDecl(FD, Op.getAccess()); // FIXME: canonical FD 1870 } else if (FunctionTemplateDecl *FunTmpl 1871 = dyn_cast<FunctionTemplateDecl>(*Op)) { 1872 // FIXME: friend operators? 1873 // FIXME: do we need to check IsAcceptableNonMemberOperatorCandidate, 1874 // later? 1875 if (!FunTmpl->getDeclContext()->isRecord()) 1876 Functions.addDecl(FunTmpl, Op.getAccess()); 1877 } 1878 } 1879} 1880 1881void ADLResult::insert(NamedDecl *New) { 1882 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())]; 1883 1884 // If we haven't yet seen a decl for this key, or the last decl 1885 // was exactly this one, we're done. 1886 if (Old == 0 || Old == New) { 1887 Old = New; 1888 return; 1889 } 1890 1891 // Otherwise, decide which is a more recent redeclaration. 1892 FunctionDecl *OldFD, *NewFD; 1893 if (isa<FunctionTemplateDecl>(New)) { 1894 OldFD = cast<FunctionTemplateDecl>(Old)->getTemplatedDecl(); 1895 NewFD = cast<FunctionTemplateDecl>(New)->getTemplatedDecl(); 1896 } else { 1897 OldFD = cast<FunctionDecl>(Old); 1898 NewFD = cast<FunctionDecl>(New); 1899 } 1900 1901 FunctionDecl *Cursor = NewFD; 1902 while (true) { 1903 Cursor = Cursor->getPreviousDeclaration(); 1904 1905 // If we got to the end without finding OldFD, OldFD is the newer 1906 // declaration; leave things as they are. 1907 if (!Cursor) return; 1908 1909 // If we do find OldFD, then NewFD is newer. 1910 if (Cursor == OldFD) break; 1911 1912 // Otherwise, keep looking. 1913 } 1914 1915 Old = New; 1916} 1917 1918void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator, 1919 Expr **Args, unsigned NumArgs, 1920 ADLResult &Result) { 1921 // Find all of the associated namespaces and classes based on the 1922 // arguments we have. 1923 AssociatedNamespaceSet AssociatedNamespaces; 1924 AssociatedClassSet AssociatedClasses; 1925 FindAssociatedClassesAndNamespaces(Args, NumArgs, 1926 AssociatedNamespaces, 1927 AssociatedClasses); 1928 1929 QualType T1, T2; 1930 if (Operator) { 1931 T1 = Args[0]->getType(); 1932 if (NumArgs >= 2) 1933 T2 = Args[1]->getType(); 1934 } 1935 1936 // C++ [basic.lookup.argdep]p3: 1937 // Let X be the lookup set produced by unqualified lookup (3.4.1) 1938 // and let Y be the lookup set produced by argument dependent 1939 // lookup (defined as follows). If X contains [...] then Y is 1940 // empty. Otherwise Y is the set of declarations found in the 1941 // namespaces associated with the argument types as described 1942 // below. The set of declarations found by the lookup of the name 1943 // is the union of X and Y. 1944 // 1945 // Here, we compute Y and add its members to the overloaded 1946 // candidate set. 1947 for (AssociatedNamespaceSet::iterator NS = AssociatedNamespaces.begin(), 1948 NSEnd = AssociatedNamespaces.end(); 1949 NS != NSEnd; ++NS) { 1950 // When considering an associated namespace, the lookup is the 1951 // same as the lookup performed when the associated namespace is 1952 // used as a qualifier (3.4.3.2) except that: 1953 // 1954 // -- Any using-directives in the associated namespace are 1955 // ignored. 1956 // 1957 // -- Any namespace-scope friend functions declared in 1958 // associated classes are visible within their respective 1959 // namespaces even if they are not visible during an ordinary 1960 // lookup (11.4). 1961 DeclContext::lookup_iterator I, E; 1962 for (llvm::tie(I, E) = (*NS)->lookup(Name); I != E; ++I) { 1963 NamedDecl *D = *I; 1964 // If the only declaration here is an ordinary friend, consider 1965 // it only if it was declared in an associated classes. 1966 if (D->getIdentifierNamespace() == Decl::IDNS_OrdinaryFriend) { 1967 DeclContext *LexDC = D->getLexicalDeclContext(); 1968 if (!AssociatedClasses.count(cast<CXXRecordDecl>(LexDC))) 1969 continue; 1970 } 1971 1972 if (isa<UsingShadowDecl>(D)) 1973 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1974 1975 if (isa<FunctionDecl>(D)) { 1976 if (Operator && 1977 !IsAcceptableNonMemberOperatorCandidate(cast<FunctionDecl>(D), 1978 T1, T2, Context)) 1979 continue; 1980 } else if (!isa<FunctionTemplateDecl>(D)) 1981 continue; 1982 1983 Result.insert(D); 1984 } 1985 } 1986} 1987 1988//---------------------------------------------------------------------------- 1989// Search for all visible declarations. 1990//---------------------------------------------------------------------------- 1991VisibleDeclConsumer::~VisibleDeclConsumer() { } 1992 1993namespace { 1994 1995class ShadowContextRAII; 1996 1997class VisibleDeclsRecord { 1998public: 1999 /// \brief An entry in the shadow map, which is optimized to store a 2000 /// single declaration (the common case) but can also store a list 2001 /// of declarations. 2002 class ShadowMapEntry { 2003 typedef llvm::SmallVector<NamedDecl *, 4> DeclVector; 2004 2005 /// \brief Contains either the solitary NamedDecl * or a vector 2006 /// of declarations. 2007 llvm::PointerUnion<NamedDecl *, DeclVector*> DeclOrVector; 2008 2009 public: 2010 ShadowMapEntry() : DeclOrVector() { } 2011 2012 void Add(NamedDecl *ND); 2013 void Destroy(); 2014 2015 // Iteration. 2016 typedef NamedDecl **iterator; 2017 iterator begin(); 2018 iterator end(); 2019 }; 2020 2021private: 2022 /// \brief A mapping from declaration names to the declarations that have 2023 /// this name within a particular scope. 2024 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap; 2025 2026 /// \brief A list of shadow maps, which is used to model name hiding. 2027 std::list<ShadowMap> ShadowMaps; 2028 2029 /// \brief The declaration contexts we have already visited. 2030 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts; 2031 2032 friend class ShadowContextRAII; 2033 2034public: 2035 /// \brief Determine whether we have already visited this context 2036 /// (and, if not, note that we are going to visit that context now). 2037 bool visitedContext(DeclContext *Ctx) { 2038 return !VisitedContexts.insert(Ctx); 2039 } 2040 2041 /// \brief Determine whether the given declaration is hidden in the 2042 /// current scope. 2043 /// 2044 /// \returns the declaration that hides the given declaration, or 2045 /// NULL if no such declaration exists. 2046 NamedDecl *checkHidden(NamedDecl *ND); 2047 2048 /// \brief Add a declaration to the current shadow map. 2049 void add(NamedDecl *ND) { ShadowMaps.back()[ND->getDeclName()].Add(ND); } 2050}; 2051 2052/// \brief RAII object that records when we've entered a shadow context. 2053class ShadowContextRAII { 2054 VisibleDeclsRecord &Visible; 2055 2056 typedef VisibleDeclsRecord::ShadowMap ShadowMap; 2057 2058public: 2059 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) { 2060 Visible.ShadowMaps.push_back(ShadowMap()); 2061 } 2062 2063 ~ShadowContextRAII() { 2064 for (ShadowMap::iterator E = Visible.ShadowMaps.back().begin(), 2065 EEnd = Visible.ShadowMaps.back().end(); 2066 E != EEnd; 2067 ++E) 2068 E->second.Destroy(); 2069 2070 Visible.ShadowMaps.pop_back(); 2071 } 2072}; 2073 2074} // end anonymous namespace 2075 2076void VisibleDeclsRecord::ShadowMapEntry::Add(NamedDecl *ND) { 2077 if (DeclOrVector.isNull()) { 2078 // 0 - > 1 elements: just set the single element information. 2079 DeclOrVector = ND; 2080 return; 2081 } 2082 2083 if (NamedDecl *PrevND = DeclOrVector.dyn_cast<NamedDecl *>()) { 2084 // 1 -> 2 elements: create the vector of results and push in the 2085 // existing declaration. 2086 DeclVector *Vec = new DeclVector; 2087 Vec->push_back(PrevND); 2088 DeclOrVector = Vec; 2089 } 2090 2091 // Add the new element to the end of the vector. 2092 DeclOrVector.get<DeclVector*>()->push_back(ND); 2093} 2094 2095void VisibleDeclsRecord::ShadowMapEntry::Destroy() { 2096 if (DeclVector *Vec = DeclOrVector.dyn_cast<DeclVector *>()) { 2097 delete Vec; 2098 DeclOrVector = ((NamedDecl *)0); 2099 } 2100} 2101 2102VisibleDeclsRecord::ShadowMapEntry::iterator 2103VisibleDeclsRecord::ShadowMapEntry::begin() { 2104 if (DeclOrVector.isNull()) 2105 return 0; 2106 2107 if (DeclOrVector.dyn_cast<NamedDecl *>()) 2108 return &reinterpret_cast<NamedDecl*&>(DeclOrVector); 2109 2110 return DeclOrVector.get<DeclVector *>()->begin(); 2111} 2112 2113VisibleDeclsRecord::ShadowMapEntry::iterator 2114VisibleDeclsRecord::ShadowMapEntry::end() { 2115 if (DeclOrVector.isNull()) 2116 return 0; 2117 2118 if (DeclOrVector.dyn_cast<NamedDecl *>()) 2119 return &reinterpret_cast<NamedDecl*&>(DeclOrVector) + 1; 2120 2121 return DeclOrVector.get<DeclVector *>()->end(); 2122} 2123 2124NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) { 2125 // Look through using declarations. 2126 ND = ND->getUnderlyingDecl(); 2127 2128 unsigned IDNS = ND->getIdentifierNamespace(); 2129 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin(); 2130 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend(); 2131 SM != SMEnd; ++SM) { 2132 ShadowMap::iterator Pos = SM->find(ND->getDeclName()); 2133 if (Pos == SM->end()) 2134 continue; 2135 2136 for (ShadowMapEntry::iterator I = Pos->second.begin(), 2137 IEnd = Pos->second.end(); 2138 I != IEnd; ++I) { 2139 // A tag declaration does not hide a non-tag declaration. 2140 if ((*I)->getIdentifierNamespace() == Decl::IDNS_Tag && 2141 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary | 2142 Decl::IDNS_ObjCProtocol))) 2143 continue; 2144 2145 // Protocols are in distinct namespaces from everything else. 2146 if ((((*I)->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol) 2147 || (IDNS & Decl::IDNS_ObjCProtocol)) && 2148 (*I)->getIdentifierNamespace() != IDNS) 2149 continue; 2150 2151 // Functions and function templates in the same scope overload 2152 // rather than hide. FIXME: Look for hiding based on function 2153 // signatures! 2154 if ((*I)->isFunctionOrFunctionTemplate() && 2155 ND->isFunctionOrFunctionTemplate() && 2156 SM == ShadowMaps.rbegin()) 2157 continue; 2158 2159 // We've found a declaration that hides this one. 2160 return *I; 2161 } 2162 } 2163 2164 return 0; 2165} 2166 2167static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result, 2168 bool QualifiedNameLookup, 2169 bool InBaseClass, 2170 VisibleDeclConsumer &Consumer, 2171 VisibleDeclsRecord &Visited) { 2172 if (!Ctx) 2173 return; 2174 2175 // Make sure we don't visit the same context twice. 2176 if (Visited.visitedContext(Ctx->getPrimaryContext())) 2177 return; 2178 2179 // Enumerate all of the results in this context. 2180 for (DeclContext *CurCtx = Ctx->getPrimaryContext(); CurCtx; 2181 CurCtx = CurCtx->getNextContext()) { 2182 for (DeclContext::decl_iterator D = CurCtx->decls_begin(), 2183 DEnd = CurCtx->decls_end(); 2184 D != DEnd; ++D) { 2185 if (NamedDecl *ND = dyn_cast<NamedDecl>(*D)) 2186 if (Result.isAcceptableDecl(ND)) { 2187 Consumer.FoundDecl(ND, Visited.checkHidden(ND), InBaseClass); 2188 Visited.add(ND); 2189 } 2190 2191 // Visit transparent contexts inside this context. 2192 if (DeclContext *InnerCtx = dyn_cast<DeclContext>(*D)) { 2193 if (InnerCtx->isTransparentContext()) 2194 LookupVisibleDecls(InnerCtx, Result, QualifiedNameLookup, InBaseClass, 2195 Consumer, Visited); 2196 } 2197 } 2198 } 2199 2200 // Traverse using directives for qualified name lookup. 2201 if (QualifiedNameLookup) { 2202 ShadowContextRAII Shadow(Visited); 2203 DeclContext::udir_iterator I, E; 2204 for (llvm::tie(I, E) = Ctx->getUsingDirectives(); I != E; ++I) { 2205 LookupVisibleDecls((*I)->getNominatedNamespace(), Result, 2206 QualifiedNameLookup, InBaseClass, Consumer, Visited); 2207 } 2208 } 2209 2210 // Traverse the contexts of inherited C++ classes. 2211 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) { 2212 if (!Record->hasDefinition()) 2213 return; 2214 2215 for (CXXRecordDecl::base_class_iterator B = Record->bases_begin(), 2216 BEnd = Record->bases_end(); 2217 B != BEnd; ++B) { 2218 QualType BaseType = B->getType(); 2219 2220 // Don't look into dependent bases, because name lookup can't look 2221 // there anyway. 2222 if (BaseType->isDependentType()) 2223 continue; 2224 2225 const RecordType *Record = BaseType->getAs<RecordType>(); 2226 if (!Record) 2227 continue; 2228 2229 // FIXME: It would be nice to be able to determine whether referencing 2230 // a particular member would be ambiguous. For example, given 2231 // 2232 // struct A { int member; }; 2233 // struct B { int member; }; 2234 // struct C : A, B { }; 2235 // 2236 // void f(C *c) { c->### } 2237 // 2238 // accessing 'member' would result in an ambiguity. However, we 2239 // could be smart enough to qualify the member with the base 2240 // class, e.g., 2241 // 2242 // c->B::member 2243 // 2244 // or 2245 // 2246 // c->A::member 2247 2248 // Find results in this base class (and its bases). 2249 ShadowContextRAII Shadow(Visited); 2250 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup, 2251 true, Consumer, Visited); 2252 } 2253 } 2254 2255 // Traverse the contexts of Objective-C classes. 2256 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) { 2257 // Traverse categories. 2258 for (ObjCCategoryDecl *Category = IFace->getCategoryList(); 2259 Category; Category = Category->getNextClassCategory()) { 2260 ShadowContextRAII Shadow(Visited); 2261 LookupVisibleDecls(Category, Result, QualifiedNameLookup, false, 2262 Consumer, Visited); 2263 } 2264 2265 // Traverse protocols. 2266 for (ObjCInterfaceDecl::protocol_iterator I = IFace->protocol_begin(), 2267 E = IFace->protocol_end(); I != E; ++I) { 2268 ShadowContextRAII Shadow(Visited); 2269 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2270 Visited); 2271 } 2272 2273 // Traverse the superclass. 2274 if (IFace->getSuperClass()) { 2275 ShadowContextRAII Shadow(Visited); 2276 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup, 2277 true, Consumer, Visited); 2278 } 2279 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) { 2280 for (ObjCProtocolDecl::protocol_iterator I = Protocol->protocol_begin(), 2281 E = Protocol->protocol_end(); I != E; ++I) { 2282 ShadowContextRAII Shadow(Visited); 2283 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2284 Visited); 2285 } 2286 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) { 2287 for (ObjCCategoryDecl::protocol_iterator I = Category->protocol_begin(), 2288 E = Category->protocol_end(); I != E; ++I) { 2289 ShadowContextRAII Shadow(Visited); 2290 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2291 Visited); 2292 } 2293 } 2294} 2295 2296static void LookupVisibleDecls(Scope *S, LookupResult &Result, 2297 UnqualUsingDirectiveSet &UDirs, 2298 VisibleDeclConsumer &Consumer, 2299 VisibleDeclsRecord &Visited) { 2300 if (!S) 2301 return; 2302 2303 if (!S->getEntity() || !S->getParent() || 2304 ((DeclContext *)S->getEntity())->isFunctionOrMethod()) { 2305 // Walk through the declarations in this Scope. 2306 for (Scope::decl_iterator D = S->decl_begin(), DEnd = S->decl_end(); 2307 D != DEnd; ++D) { 2308 if (NamedDecl *ND = dyn_cast<NamedDecl>((Decl *)((*D).get()))) 2309 if (Result.isAcceptableDecl(ND)) { 2310 Consumer.FoundDecl(ND, Visited.checkHidden(ND), false); 2311 Visited.add(ND); 2312 } 2313 } 2314 } 2315 2316 // FIXME: C++ [temp.local]p8 2317 DeclContext *Entity = 0; 2318 if (S->getEntity()) { 2319 // Look into this scope's declaration context, along with any of its 2320 // parent lookup contexts (e.g., enclosing classes), up to the point 2321 // where we hit the context stored in the next outer scope. 2322 Entity = (DeclContext *)S->getEntity(); 2323 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME 2324 2325 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx); 2326 Ctx = Ctx->getLookupParent()) { 2327 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 2328 if (Method->isInstanceMethod()) { 2329 // For instance methods, look for ivars in the method's interface. 2330 LookupResult IvarResult(Result.getSema(), Result.getLookupName(), 2331 Result.getNameLoc(), Sema::LookupMemberName); 2332 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) 2333 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false, 2334 /*InBaseClass=*/false, Consumer, Visited); 2335 } 2336 2337 // We've already performed all of the name lookup that we need 2338 // to for Objective-C methods; the next context will be the 2339 // outer scope. 2340 break; 2341 } 2342 2343 if (Ctx->isFunctionOrMethod()) 2344 continue; 2345 2346 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false, 2347 /*InBaseClass=*/false, Consumer, Visited); 2348 } 2349 } else if (!S->getParent()) { 2350 // Look into the translation unit scope. We walk through the translation 2351 // unit's declaration context, because the Scope itself won't have all of 2352 // the declarations if we loaded a precompiled header. 2353 // FIXME: We would like the translation unit's Scope object to point to the 2354 // translation unit, so we don't need this special "if" branch. However, 2355 // doing so would force the normal C++ name-lookup code to look into the 2356 // translation unit decl when the IdentifierInfo chains would suffice. 2357 // Once we fix that problem (which is part of a more general "don't look 2358 // in DeclContexts unless we have to" optimization), we can eliminate this. 2359 Entity = Result.getSema().Context.getTranslationUnitDecl(); 2360 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false, 2361 /*InBaseClass=*/false, Consumer, Visited); 2362 } 2363 2364 if (Entity) { 2365 // Lookup visible declarations in any namespaces found by using 2366 // directives. 2367 UnqualUsingDirectiveSet::const_iterator UI, UEnd; 2368 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(Entity); 2369 for (; UI != UEnd; ++UI) 2370 LookupVisibleDecls(const_cast<DeclContext *>(UI->getNominatedNamespace()), 2371 Result, /*QualifiedNameLookup=*/false, 2372 /*InBaseClass=*/false, Consumer, Visited); 2373 } 2374 2375 // Lookup names in the parent scope. 2376 ShadowContextRAII Shadow(Visited); 2377 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited); 2378} 2379 2380void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind, 2381 VisibleDeclConsumer &Consumer) { 2382 // Determine the set of using directives available during 2383 // unqualified name lookup. 2384 Scope *Initial = S; 2385 UnqualUsingDirectiveSet UDirs; 2386 if (getLangOptions().CPlusPlus) { 2387 // Find the first namespace or translation-unit scope. 2388 while (S && !isNamespaceOrTranslationUnitScope(S)) 2389 S = S->getParent(); 2390 2391 UDirs.visitScopeChain(Initial, S); 2392 } 2393 UDirs.done(); 2394 2395 // Look for visible declarations. 2396 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2397 VisibleDeclsRecord Visited; 2398 ShadowContextRAII Shadow(Visited); 2399 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited); 2400} 2401 2402void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind, 2403 VisibleDeclConsumer &Consumer) { 2404 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2405 VisibleDeclsRecord Visited; 2406 ShadowContextRAII Shadow(Visited); 2407 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true, 2408 /*InBaseClass=*/false, Consumer, Visited); 2409} 2410 2411//---------------------------------------------------------------------------- 2412// Typo correction 2413//---------------------------------------------------------------------------- 2414 2415namespace { 2416class TypoCorrectionConsumer : public VisibleDeclConsumer { 2417 /// \brief The name written that is a typo in the source. 2418 llvm::StringRef Typo; 2419 2420 /// \brief The results found that have the smallest edit distance 2421 /// found (so far) with the typo name. 2422 llvm::SmallVector<NamedDecl *, 4> BestResults; 2423 2424 /// \brief The best edit distance found so far. 2425 unsigned BestEditDistance; 2426 2427public: 2428 explicit TypoCorrectionConsumer(IdentifierInfo *Typo) 2429 : Typo(Typo->getName()) { } 2430 2431 virtual void FoundDecl(NamedDecl *ND, NamedDecl *Hiding, bool InBaseClass); 2432 2433 typedef llvm::SmallVector<NamedDecl *, 4>::const_iterator iterator; 2434 iterator begin() const { return BestResults.begin(); } 2435 iterator end() const { return BestResults.end(); } 2436 bool empty() const { return BestResults.empty(); } 2437 2438 unsigned getBestEditDistance() const { return BestEditDistance; } 2439}; 2440 2441} 2442 2443void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding, 2444 bool InBaseClass) { 2445 // Don't consider hidden names for typo correction. 2446 if (Hiding) 2447 return; 2448 2449 // Only consider entities with identifiers for names, ignoring 2450 // special names (constructors, overloaded operators, selectors, 2451 // etc.). 2452 IdentifierInfo *Name = ND->getIdentifier(); 2453 if (!Name) 2454 return; 2455 2456 // Compute the edit distance between the typo and the name of this 2457 // entity. If this edit distance is not worse than the best edit 2458 // distance we've seen so far, add it to the list of results. 2459 unsigned ED = Typo.edit_distance(Name->getName()); 2460 if (!BestResults.empty()) { 2461 if (ED < BestEditDistance) { 2462 // This result is better than any we've seen before; clear out 2463 // the previous results. 2464 BestResults.clear(); 2465 BestEditDistance = ED; 2466 } else if (ED > BestEditDistance) { 2467 // This result is worse than the best results we've seen so far; 2468 // ignore it. 2469 return; 2470 } 2471 } else 2472 BestEditDistance = ED; 2473 2474 BestResults.push_back(ND); 2475} 2476 2477/// \brief Try to "correct" a typo in the source code by finding 2478/// visible declarations whose names are similar to the name that was 2479/// present in the source code. 2480/// 2481/// \param Res the \c LookupResult structure that contains the name 2482/// that was present in the source code along with the name-lookup 2483/// criteria used to search for the name. On success, this structure 2484/// will contain the results of name lookup. 2485/// 2486/// \param S the scope in which name lookup occurs. 2487/// 2488/// \param SS the nested-name-specifier that precedes the name we're 2489/// looking for, if present. 2490/// 2491/// \param MemberContext if non-NULL, the context in which to look for 2492/// a member access expression. 2493/// 2494/// \param EnteringContext whether we're entering the context described by 2495/// the nested-name-specifier SS. 2496/// 2497/// \param OPT when non-NULL, the search for visible declarations will 2498/// also walk the protocols in the qualified interfaces of \p OPT. 2499/// 2500/// \returns true if the typo was corrected, in which case the \p Res 2501/// structure will contain the results of name lookup for the 2502/// corrected name. Otherwise, returns false. 2503bool Sema::CorrectTypo(LookupResult &Res, Scope *S, const CXXScopeSpec *SS, 2504 DeclContext *MemberContext, bool EnteringContext, 2505 const ObjCObjectPointerType *OPT) { 2506 if (Diags.hasFatalErrorOccurred()) 2507 return false; 2508 2509 // Provide a stop gap for files that are just seriously broken. Trying 2510 // to correct all typos can turn into a HUGE performance penalty, causing 2511 // some files to take minutes to get rejected by the parser. 2512 // FIXME: Is this the right solution? 2513 if (TyposCorrected == 20) 2514 return false; 2515 ++TyposCorrected; 2516 2517 // We only attempt to correct typos for identifiers. 2518 IdentifierInfo *Typo = Res.getLookupName().getAsIdentifierInfo(); 2519 if (!Typo) 2520 return false; 2521 2522 // If the scope specifier itself was invalid, don't try to correct 2523 // typos. 2524 if (SS && SS->isInvalid()) 2525 return false; 2526 2527 // Never try to correct typos during template deduction or 2528 // instantiation. 2529 if (!ActiveTemplateInstantiations.empty()) 2530 return false; 2531 2532 TypoCorrectionConsumer Consumer(Typo); 2533 if (MemberContext) { 2534 LookupVisibleDecls(MemberContext, Res.getLookupKind(), Consumer); 2535 2536 // Look in qualified interfaces. 2537 if (OPT) { 2538 for (ObjCObjectPointerType::qual_iterator 2539 I = OPT->qual_begin(), E = OPT->qual_end(); 2540 I != E; ++I) 2541 LookupVisibleDecls(*I, Res.getLookupKind(), Consumer); 2542 } 2543 } else if (SS && SS->isSet()) { 2544 DeclContext *DC = computeDeclContext(*SS, EnteringContext); 2545 if (!DC) 2546 return false; 2547 2548 LookupVisibleDecls(DC, Res.getLookupKind(), Consumer); 2549 } else { 2550 LookupVisibleDecls(S, Res.getLookupKind(), Consumer); 2551 } 2552 2553 if (Consumer.empty()) 2554 return false; 2555 2556 // Only allow a single, closest name in the result set (it's okay to 2557 // have overloads of that name, though). 2558 TypoCorrectionConsumer::iterator I = Consumer.begin(); 2559 DeclarationName BestName = (*I)->getDeclName(); 2560 2561 // If we've found an Objective-C ivar or property, don't perform 2562 // name lookup again; we'll just return the result directly. 2563 NamedDecl *FoundBest = 0; 2564 if (isa<ObjCIvarDecl>(*I) || isa<ObjCPropertyDecl>(*I)) 2565 FoundBest = *I; 2566 ++I; 2567 for(TypoCorrectionConsumer::iterator IEnd = Consumer.end(); I != IEnd; ++I) { 2568 if (BestName != (*I)->getDeclName()) 2569 return false; 2570 2571 // FIXME: If there are both ivars and properties of the same name, 2572 // don't return both because the callee can't handle two 2573 // results. We really need to separate ivar lookup from property 2574 // lookup to avoid this problem. 2575 FoundBest = 0; 2576 } 2577 2578 // BestName is the closest viable name to what the user 2579 // typed. However, to make sure that we don't pick something that's 2580 // way off, make sure that the user typed at least 3 characters for 2581 // each correction. 2582 unsigned ED = Consumer.getBestEditDistance(); 2583 if (ED == 0 || (BestName.getAsIdentifierInfo()->getName().size() / ED) < 3) 2584 return false; 2585 2586 // Perform name lookup again with the name we chose, and declare 2587 // success if we found something that was not ambiguous. 2588 Res.clear(); 2589 Res.setLookupName(BestName); 2590 2591 // If we found an ivar or property, add that result; no further 2592 // lookup is required. 2593 if (FoundBest) 2594 Res.addDecl(FoundBest); 2595 // If we're looking into the context of a member, perform qualified 2596 // name lookup on the best name. 2597 else if (MemberContext) 2598 LookupQualifiedName(Res, MemberContext); 2599 // Perform lookup as if we had just parsed the best name. 2600 else 2601 LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false, 2602 EnteringContext); 2603 2604 if (Res.isAmbiguous()) { 2605 Res.suppressDiagnostics(); 2606 return false; 2607 } 2608 2609 return Res.getResultKind() != LookupResult::NotFound; 2610} 2611