SemaLookup.cpp revision 2bcda8c1cf367dcc5d4fb4b244be48bdee191d8f
1//===--------------------- SemaLookup.cpp - Name Lookup ------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements name lookup for C, C++, Objective-C, and 11// Objective-C++. 12// 13//===----------------------------------------------------------------------===// 14#include "Sema.h" 15#include "Lookup.h" 16#include "clang/AST/ASTContext.h" 17#include "clang/AST/CXXInheritance.h" 18#include "clang/AST/Decl.h" 19#include "clang/AST/DeclCXX.h" 20#include "clang/AST/DeclObjC.h" 21#include "clang/AST/DeclTemplate.h" 22#include "clang/AST/Expr.h" 23#include "clang/AST/ExprCXX.h" 24#include "clang/Parse/DeclSpec.h" 25#include "clang/Basic/Builtins.h" 26#include "clang/Basic/LangOptions.h" 27#include "llvm/ADT/STLExtras.h" 28#include "llvm/ADT/SmallPtrSet.h" 29#include "llvm/Support/ErrorHandling.h" 30#include <list> 31#include <set> 32#include <vector> 33#include <iterator> 34#include <utility> 35#include <algorithm> 36 37using namespace clang; 38 39namespace { 40 class UnqualUsingEntry { 41 const DeclContext *Nominated; 42 const DeclContext *CommonAncestor; 43 44 public: 45 UnqualUsingEntry(const DeclContext *Nominated, 46 const DeclContext *CommonAncestor) 47 : Nominated(Nominated), CommonAncestor(CommonAncestor) { 48 } 49 50 const DeclContext *getCommonAncestor() const { 51 return CommonAncestor; 52 } 53 54 const DeclContext *getNominatedNamespace() const { 55 return Nominated; 56 } 57 58 // Sort by the pointer value of the common ancestor. 59 struct Comparator { 60 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) { 61 return L.getCommonAncestor() < R.getCommonAncestor(); 62 } 63 64 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) { 65 return E.getCommonAncestor() < DC; 66 } 67 68 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) { 69 return DC < E.getCommonAncestor(); 70 } 71 }; 72 }; 73 74 /// A collection of using directives, as used by C++ unqualified 75 /// lookup. 76 class UnqualUsingDirectiveSet { 77 typedef llvm::SmallVector<UnqualUsingEntry, 8> ListTy; 78 79 ListTy list; 80 llvm::SmallPtrSet<DeclContext*, 8> visited; 81 82 public: 83 UnqualUsingDirectiveSet() {} 84 85 void visitScopeChain(Scope *S, Scope *InnermostFileScope) { 86 // C++ [namespace.udir]p1: 87 // During unqualified name lookup, the names appear as if they 88 // were declared in the nearest enclosing namespace which contains 89 // both the using-directive and the nominated namespace. 90 DeclContext *InnermostFileDC 91 = static_cast<DeclContext*>(InnermostFileScope->getEntity()); 92 assert(InnermostFileDC && InnermostFileDC->isFileContext()); 93 94 for (; S; S = S->getParent()) { 95 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) { 96 DeclContext *EffectiveDC = (Ctx->isFileContext() ? Ctx : InnermostFileDC); 97 visit(Ctx, EffectiveDC); 98 } else { 99 Scope::udir_iterator I = S->using_directives_begin(), 100 End = S->using_directives_end(); 101 102 for (; I != End; ++I) 103 visit(I->getAs<UsingDirectiveDecl>(), InnermostFileDC); 104 } 105 } 106 } 107 108 // Visits a context and collect all of its using directives 109 // recursively. Treats all using directives as if they were 110 // declared in the context. 111 // 112 // A given context is only every visited once, so it is important 113 // that contexts be visited from the inside out in order to get 114 // the effective DCs right. 115 void visit(DeclContext *DC, DeclContext *EffectiveDC) { 116 if (!visited.insert(DC)) 117 return; 118 119 addUsingDirectives(DC, EffectiveDC); 120 } 121 122 // Visits a using directive and collects all of its using 123 // directives recursively. Treats all using directives as if they 124 // were declared in the effective DC. 125 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 126 DeclContext *NS = UD->getNominatedNamespace(); 127 if (!visited.insert(NS)) 128 return; 129 130 addUsingDirective(UD, EffectiveDC); 131 addUsingDirectives(NS, EffectiveDC); 132 } 133 134 // Adds all the using directives in a context (and those nominated 135 // by its using directives, transitively) as if they appeared in 136 // the given effective context. 137 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) { 138 llvm::SmallVector<DeclContext*,4> queue; 139 while (true) { 140 DeclContext::udir_iterator I, End; 141 for (llvm::tie(I, End) = DC->getUsingDirectives(); I != End; ++I) { 142 UsingDirectiveDecl *UD = *I; 143 DeclContext *NS = UD->getNominatedNamespace(); 144 if (visited.insert(NS)) { 145 addUsingDirective(UD, EffectiveDC); 146 queue.push_back(NS); 147 } 148 } 149 150 if (queue.empty()) 151 return; 152 153 DC = queue.back(); 154 queue.pop_back(); 155 } 156 } 157 158 // Add a using directive as if it had been declared in the given 159 // context. This helps implement C++ [namespace.udir]p3: 160 // The using-directive is transitive: if a scope contains a 161 // using-directive that nominates a second namespace that itself 162 // contains using-directives, the effect is as if the 163 // using-directives from the second namespace also appeared in 164 // the first. 165 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 166 // Find the common ancestor between the effective context and 167 // the nominated namespace. 168 DeclContext *Common = UD->getNominatedNamespace(); 169 while (!Common->Encloses(EffectiveDC)) 170 Common = Common->getParent(); 171 Common = Common->getPrimaryContext(); 172 173 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common)); 174 } 175 176 void done() { 177 std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator()); 178 } 179 180 typedef ListTy::iterator iterator; 181 typedef ListTy::const_iterator const_iterator; 182 183 iterator begin() { return list.begin(); } 184 iterator end() { return list.end(); } 185 const_iterator begin() const { return list.begin(); } 186 const_iterator end() const { return list.end(); } 187 188 std::pair<const_iterator,const_iterator> 189 getNamespacesFor(DeclContext *DC) const { 190 return std::equal_range(begin(), end(), DC->getPrimaryContext(), 191 UnqualUsingEntry::Comparator()); 192 } 193 }; 194} 195 196// Retrieve the set of identifier namespaces that correspond to a 197// specific kind of name lookup. 198static inline unsigned getIDNS(Sema::LookupNameKind NameKind, 199 bool CPlusPlus, 200 bool Redeclaration) { 201 unsigned IDNS = 0; 202 switch (NameKind) { 203 case Sema::LookupOrdinaryName: 204 case Sema::LookupRedeclarationWithLinkage: 205 IDNS = Decl::IDNS_Ordinary; 206 if (CPlusPlus) { 207 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace; 208 if (Redeclaration) IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend; 209 } 210 break; 211 212 case Sema::LookupOperatorName: 213 // Operator lookup is its own crazy thing; it is not the same 214 // as (e.g.) looking up an operator name for redeclaration. 215 assert(!Redeclaration && "cannot do redeclaration operator lookup"); 216 IDNS = Decl::IDNS_NonMemberOperator; 217 break; 218 219 case Sema::LookupTagName: 220 if (CPlusPlus) { 221 IDNS = Decl::IDNS_Type; 222 223 // When looking for a redeclaration of a tag name, we add: 224 // 1) TagFriend to find undeclared friend decls 225 // 2) Namespace because they can't "overload" with tag decls. 226 // 3) Tag because it includes class templates, which can't 227 // "overload" with tag decls. 228 if (Redeclaration) 229 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace; 230 } else { 231 IDNS = Decl::IDNS_Tag; 232 } 233 break; 234 235 case Sema::LookupMemberName: 236 IDNS = Decl::IDNS_Member; 237 if (CPlusPlus) 238 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary; 239 break; 240 241 case Sema::LookupNestedNameSpecifierName: 242 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace; 243 break; 244 245 case Sema::LookupNamespaceName: 246 IDNS = Decl::IDNS_Namespace; 247 break; 248 249 case Sema::LookupUsingDeclName: 250 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag 251 | Decl::IDNS_Member | Decl::IDNS_Using; 252 break; 253 254 case Sema::LookupObjCProtocolName: 255 IDNS = Decl::IDNS_ObjCProtocol; 256 break; 257 } 258 return IDNS; 259} 260 261void LookupResult::configure() { 262 IDNS = getIDNS(LookupKind, 263 SemaRef.getLangOptions().CPlusPlus, 264 isForRedeclaration()); 265 266 // If we're looking for one of the allocation or deallocation 267 // operators, make sure that the implicitly-declared new and delete 268 // operators can be found. 269 if (!isForRedeclaration()) { 270 switch (Name.getCXXOverloadedOperator()) { 271 case OO_New: 272 case OO_Delete: 273 case OO_Array_New: 274 case OO_Array_Delete: 275 SemaRef.DeclareGlobalNewDelete(); 276 break; 277 278 default: 279 break; 280 } 281 } 282} 283 284// Necessary because CXXBasePaths is not complete in Sema.h 285void LookupResult::deletePaths(CXXBasePaths *Paths) { 286 delete Paths; 287} 288 289/// Resolves the result kind of this lookup. 290void LookupResult::resolveKind() { 291 unsigned N = Decls.size(); 292 293 // Fast case: no possible ambiguity. 294 if (N == 0) { 295 assert(ResultKind == NotFound || ResultKind == NotFoundInCurrentInstantiation); 296 return; 297 } 298 299 // If there's a single decl, we need to examine it to decide what 300 // kind of lookup this is. 301 if (N == 1) { 302 NamedDecl *D = (*Decls.begin())->getUnderlyingDecl(); 303 if (isa<FunctionTemplateDecl>(D)) 304 ResultKind = FoundOverloaded; 305 else if (isa<UnresolvedUsingValueDecl>(D)) 306 ResultKind = FoundUnresolvedValue; 307 return; 308 } 309 310 // Don't do any extra resolution if we've already resolved as ambiguous. 311 if (ResultKind == Ambiguous) return; 312 313 llvm::SmallPtrSet<NamedDecl*, 16> Unique; 314 315 bool Ambiguous = false; 316 bool HasTag = false, HasFunction = false, HasNonFunction = false; 317 bool HasFunctionTemplate = false, HasUnresolved = false; 318 319 unsigned UniqueTagIndex = 0; 320 321 unsigned I = 0; 322 while (I < N) { 323 NamedDecl *D = Decls[I]->getUnderlyingDecl(); 324 D = cast<NamedDecl>(D->getCanonicalDecl()); 325 326 if (!Unique.insert(D)) { 327 // If it's not unique, pull something off the back (and 328 // continue at this index). 329 Decls[I] = Decls[--N]; 330 } else { 331 // Otherwise, do some decl type analysis and then continue. 332 333 if (isa<UnresolvedUsingValueDecl>(D)) { 334 HasUnresolved = true; 335 } else if (isa<TagDecl>(D)) { 336 if (HasTag) 337 Ambiguous = true; 338 UniqueTagIndex = I; 339 HasTag = true; 340 } else if (isa<FunctionTemplateDecl>(D)) { 341 HasFunction = true; 342 HasFunctionTemplate = true; 343 } else if (isa<FunctionDecl>(D)) { 344 HasFunction = true; 345 } else { 346 if (HasNonFunction) 347 Ambiguous = true; 348 HasNonFunction = true; 349 } 350 I++; 351 } 352 } 353 354 // C++ [basic.scope.hiding]p2: 355 // A class name or enumeration name can be hidden by the name of 356 // an object, function, or enumerator declared in the same 357 // scope. If a class or enumeration name and an object, function, 358 // or enumerator are declared in the same scope (in any order) 359 // with the same name, the class or enumeration name is hidden 360 // wherever the object, function, or enumerator name is visible. 361 // But it's still an error if there are distinct tag types found, 362 // even if they're not visible. (ref?) 363 if (HideTags && HasTag && !Ambiguous && 364 (HasFunction || HasNonFunction || HasUnresolved)) 365 Decls[UniqueTagIndex] = Decls[--N]; 366 367 Decls.set_size(N); 368 369 if (HasNonFunction && (HasFunction || HasUnresolved)) 370 Ambiguous = true; 371 372 if (Ambiguous) 373 setAmbiguous(LookupResult::AmbiguousReference); 374 else if (HasUnresolved) 375 ResultKind = LookupResult::FoundUnresolvedValue; 376 else if (N > 1 || HasFunctionTemplate) 377 ResultKind = LookupResult::FoundOverloaded; 378 else 379 ResultKind = LookupResult::Found; 380} 381 382void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) { 383 CXXBasePaths::const_paths_iterator I, E; 384 DeclContext::lookup_iterator DI, DE; 385 for (I = P.begin(), E = P.end(); I != E; ++I) 386 for (llvm::tie(DI,DE) = I->Decls; DI != DE; ++DI) 387 addDecl(*DI); 388} 389 390void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) { 391 Paths = new CXXBasePaths; 392 Paths->swap(P); 393 addDeclsFromBasePaths(*Paths); 394 resolveKind(); 395 setAmbiguous(AmbiguousBaseSubobjects); 396} 397 398void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) { 399 Paths = new CXXBasePaths; 400 Paths->swap(P); 401 addDeclsFromBasePaths(*Paths); 402 resolveKind(); 403 setAmbiguous(AmbiguousBaseSubobjectTypes); 404} 405 406void LookupResult::print(llvm::raw_ostream &Out) { 407 Out << Decls.size() << " result(s)"; 408 if (isAmbiguous()) Out << ", ambiguous"; 409 if (Paths) Out << ", base paths present"; 410 411 for (iterator I = begin(), E = end(); I != E; ++I) { 412 Out << "\n"; 413 (*I)->print(Out, 2); 414 } 415} 416 417/// \brief Lookup a builtin function, when name lookup would otherwise 418/// fail. 419static bool LookupBuiltin(Sema &S, LookupResult &R) { 420 Sema::LookupNameKind NameKind = R.getLookupKind(); 421 422 // If we didn't find a use of this identifier, and if the identifier 423 // corresponds to a compiler builtin, create the decl object for the builtin 424 // now, injecting it into translation unit scope, and return it. 425 if (NameKind == Sema::LookupOrdinaryName || 426 NameKind == Sema::LookupRedeclarationWithLinkage) { 427 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo(); 428 if (II) { 429 // If this is a builtin on this (or all) targets, create the decl. 430 if (unsigned BuiltinID = II->getBuiltinID()) { 431 // In C++, we don't have any predefined library functions like 432 // 'malloc'. Instead, we'll just error. 433 if (S.getLangOptions().CPlusPlus && 434 S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 435 return false; 436 437 NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 438 S.TUScope, R.isForRedeclaration(), 439 R.getNameLoc()); 440 if (D) 441 R.addDecl(D); 442 return (D != NULL); 443 } 444 } 445 } 446 447 return false; 448} 449 450// Adds all qualifying matches for a name within a decl context to the 451// given lookup result. Returns true if any matches were found. 452static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) { 453 bool Found = false; 454 455 DeclContext::lookup_const_iterator I, E; 456 for (llvm::tie(I, E) = DC->lookup(R.getLookupName()); I != E; ++I) { 457 NamedDecl *D = *I; 458 if (R.isAcceptableDecl(D)) { 459 R.addDecl(D); 460 Found = true; 461 } 462 } 463 464 if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R)) 465 return true; 466 467 if (R.getLookupName().getNameKind() 468 != DeclarationName::CXXConversionFunctionName || 469 R.getLookupName().getCXXNameType()->isDependentType() || 470 !isa<CXXRecordDecl>(DC)) 471 return Found; 472 473 // C++ [temp.mem]p6: 474 // A specialization of a conversion function template is not found by 475 // name lookup. Instead, any conversion function templates visible in the 476 // context of the use are considered. [...] 477 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC); 478 if (!Record->isDefinition()) 479 return Found; 480 481 const UnresolvedSetImpl *Unresolved = Record->getConversionFunctions(); 482 for (UnresolvedSetImpl::iterator U = Unresolved->begin(), 483 UEnd = Unresolved->end(); U != UEnd; ++U) { 484 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U); 485 if (!ConvTemplate) 486 continue; 487 488 // When we're performing lookup for the purposes of redeclaration, just 489 // add the conversion function template. When we deduce template 490 // arguments for specializations, we'll end up unifying the return 491 // type of the new declaration with the type of the function template. 492 if (R.isForRedeclaration()) { 493 R.addDecl(ConvTemplate); 494 Found = true; 495 continue; 496 } 497 498 // C++ [temp.mem]p6: 499 // [...] For each such operator, if argument deduction succeeds 500 // (14.9.2.3), the resulting specialization is used as if found by 501 // name lookup. 502 // 503 // When referencing a conversion function for any purpose other than 504 // a redeclaration (such that we'll be building an expression with the 505 // result), perform template argument deduction and place the 506 // specialization into the result set. We do this to avoid forcing all 507 // callers to perform special deduction for conversion functions. 508 Sema::TemplateDeductionInfo Info(R.getSema().Context, R.getNameLoc()); 509 FunctionDecl *Specialization = 0; 510 511 const FunctionProtoType *ConvProto 512 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>(); 513 assert(ConvProto && "Nonsensical conversion function template type"); 514 515 // Compute the type of the function that we would expect the conversion 516 // function to have, if it were to match the name given. 517 // FIXME: Calling convention! 518 FunctionType::ExtInfo ConvProtoInfo = ConvProto->getExtInfo(); 519 QualType ExpectedType 520 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(), 521 0, 0, ConvProto->isVariadic(), 522 ConvProto->getTypeQuals(), 523 false, false, 0, 0, 524 ConvProtoInfo.withCallingConv(CC_Default)); 525 526 // Perform template argument deduction against the type that we would 527 // expect the function to have. 528 if (R.getSema().DeduceTemplateArguments(ConvTemplate, 0, ExpectedType, 529 Specialization, Info) 530 == Sema::TDK_Success) { 531 R.addDecl(Specialization); 532 Found = true; 533 } 534 } 535 536 return Found; 537} 538 539// Performs C++ unqualified lookup into the given file context. 540static bool 541CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context, 542 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) { 543 544 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!"); 545 546 // Perform direct name lookup into the LookupCtx. 547 bool Found = LookupDirect(S, R, NS); 548 549 // Perform direct name lookup into the namespaces nominated by the 550 // using directives whose common ancestor is this namespace. 551 UnqualUsingDirectiveSet::const_iterator UI, UEnd; 552 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(NS); 553 554 for (; UI != UEnd; ++UI) 555 if (LookupDirect(S, R, UI->getNominatedNamespace())) 556 Found = true; 557 558 R.resolveKind(); 559 560 return Found; 561} 562 563static bool isNamespaceOrTranslationUnitScope(Scope *S) { 564 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) 565 return Ctx->isFileContext(); 566 return false; 567} 568 569// Find the next outer declaration context from this scope. This 570// routine actually returns the semantic outer context, which may 571// differ from the lexical context (encoded directly in the Scope 572// stack) when we are parsing a member of a class template. In this 573// case, the second element of the pair will be true, to indicate that 574// name lookup should continue searching in this semantic context when 575// it leaves the current template parameter scope. 576static std::pair<DeclContext *, bool> findOuterContext(Scope *S) { 577 DeclContext *DC = static_cast<DeclContext *>(S->getEntity()); 578 DeclContext *Lexical = 0; 579 for (Scope *OuterS = S->getParent(); OuterS; 580 OuterS = OuterS->getParent()) { 581 if (OuterS->getEntity()) { 582 Lexical = static_cast<DeclContext *>(OuterS->getEntity()); 583 break; 584 } 585 } 586 587 // C++ [temp.local]p8: 588 // In the definition of a member of a class template that appears 589 // outside of the namespace containing the class template 590 // definition, the name of a template-parameter hides the name of 591 // a member of this namespace. 592 // 593 // Example: 594 // 595 // namespace N { 596 // class C { }; 597 // 598 // template<class T> class B { 599 // void f(T); 600 // }; 601 // } 602 // 603 // template<class C> void N::B<C>::f(C) { 604 // C b; // C is the template parameter, not N::C 605 // } 606 // 607 // In this example, the lexical context we return is the 608 // TranslationUnit, while the semantic context is the namespace N. 609 if (!Lexical || !DC || !S->getParent() || 610 !S->getParent()->isTemplateParamScope()) 611 return std::make_pair(Lexical, false); 612 613 // Find the outermost template parameter scope. 614 // For the example, this is the scope for the template parameters of 615 // template<class C>. 616 Scope *OutermostTemplateScope = S->getParent(); 617 while (OutermostTemplateScope->getParent() && 618 OutermostTemplateScope->getParent()->isTemplateParamScope()) 619 OutermostTemplateScope = OutermostTemplateScope->getParent(); 620 621 // Find the namespace context in which the original scope occurs. In 622 // the example, this is namespace N. 623 DeclContext *Semantic = DC; 624 while (!Semantic->isFileContext()) 625 Semantic = Semantic->getParent(); 626 627 // Find the declaration context just outside of the template 628 // parameter scope. This is the context in which the template is 629 // being lexically declaration (a namespace context). In the 630 // example, this is the global scope. 631 if (Lexical->isFileContext() && !Lexical->Equals(Semantic) && 632 Lexical->Encloses(Semantic)) 633 return std::make_pair(Semantic, true); 634 635 return std::make_pair(Lexical, false); 636} 637 638bool Sema::CppLookupName(LookupResult &R, Scope *S) { 639 assert(getLangOptions().CPlusPlus && "Can perform only C++ lookup"); 640 641 DeclarationName Name = R.getLookupName(); 642 643 Scope *Initial = S; 644 IdentifierResolver::iterator 645 I = IdResolver.begin(Name), 646 IEnd = IdResolver.end(); 647 648 // First we lookup local scope. 649 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir] 650 // ...During unqualified name lookup (3.4.1), the names appear as if 651 // they were declared in the nearest enclosing namespace which contains 652 // both the using-directive and the nominated namespace. 653 // [Note: in this context, "contains" means "contains directly or 654 // indirectly". 655 // 656 // For example: 657 // namespace A { int i; } 658 // void foo() { 659 // int i; 660 // { 661 // using namespace A; 662 // ++i; // finds local 'i', A::i appears at global scope 663 // } 664 // } 665 // 666 DeclContext *OutsideOfTemplateParamDC = 0; 667 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) { 668 // Check whether the IdResolver has anything in this scope. 669 bool Found = false; 670 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) { 671 if (R.isAcceptableDecl(*I)) { 672 Found = true; 673 R.addDecl(*I); 674 } 675 } 676 if (Found) { 677 R.resolveKind(); 678 return true; 679 } 680 681 DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity()); 682 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC && 683 S->getParent() && !S->getParent()->isTemplateParamScope()) { 684 // We've just searched the last template parameter scope and 685 // found nothing, so look into the the contexts between the 686 // lexical and semantic declaration contexts returned by 687 // findOuterContext(). This implements the name lookup behavior 688 // of C++ [temp.local]p8. 689 Ctx = OutsideOfTemplateParamDC; 690 OutsideOfTemplateParamDC = 0; 691 } 692 693 if (Ctx) { 694 DeclContext *OuterCtx; 695 bool SearchAfterTemplateScope; 696 llvm::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S); 697 if (SearchAfterTemplateScope) 698 OutsideOfTemplateParamDC = OuterCtx; 699 700 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 701 // We do not directly look into transparent contexts, since 702 // those entities will be found in the nearest enclosing 703 // non-transparent context. 704 if (Ctx->isTransparentContext()) 705 continue; 706 707 // We do not look directly into function or method contexts, 708 // since all of the local variables and parameters of the 709 // function/method are present within the Scope. 710 if (Ctx->isFunctionOrMethod()) { 711 // If we have an Objective-C instance method, look for ivars 712 // in the corresponding interface. 713 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 714 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo()) 715 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) { 716 ObjCInterfaceDecl *ClassDeclared; 717 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable( 718 Name.getAsIdentifierInfo(), 719 ClassDeclared)) { 720 if (R.isAcceptableDecl(Ivar)) { 721 R.addDecl(Ivar); 722 R.resolveKind(); 723 return true; 724 } 725 } 726 } 727 } 728 729 continue; 730 } 731 732 // Perform qualified name lookup into this context. 733 // FIXME: In some cases, we know that every name that could be found by 734 // this qualified name lookup will also be on the identifier chain. For 735 // example, inside a class without any base classes, we never need to 736 // perform qualified lookup because all of the members are on top of the 737 // identifier chain. 738 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true)) 739 return true; 740 } 741 } 742 } 743 744 // Stop if we ran out of scopes. 745 // FIXME: This really, really shouldn't be happening. 746 if (!S) return false; 747 748 // Collect UsingDirectiveDecls in all scopes, and recursively all 749 // nominated namespaces by those using-directives. 750 // 751 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we 752 // don't build it for each lookup! 753 754 UnqualUsingDirectiveSet UDirs; 755 UDirs.visitScopeChain(Initial, S); 756 UDirs.done(); 757 758 // Lookup namespace scope, and global scope. 759 // Unqualified name lookup in C++ requires looking into scopes 760 // that aren't strictly lexical, and therefore we walk through the 761 // context as well as walking through the scopes. 762 763 for (; S; S = S->getParent()) { 764 // Check whether the IdResolver has anything in this scope. 765 bool Found = false; 766 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) { 767 if (R.isAcceptableDecl(*I)) { 768 // We found something. Look for anything else in our scope 769 // with this same name and in an acceptable identifier 770 // namespace, so that we can construct an overload set if we 771 // need to. 772 Found = true; 773 R.addDecl(*I); 774 } 775 } 776 777 if (Found && S->isTemplateParamScope()) { 778 R.resolveKind(); 779 return true; 780 } 781 782 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity()); 783 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC && 784 S->getParent() && !S->getParent()->isTemplateParamScope()) { 785 // We've just searched the last template parameter scope and 786 // found nothing, so look into the the contexts between the 787 // lexical and semantic declaration contexts returned by 788 // findOuterContext(). This implements the name lookup behavior 789 // of C++ [temp.local]p8. 790 Ctx = OutsideOfTemplateParamDC; 791 OutsideOfTemplateParamDC = 0; 792 } 793 794 if (Ctx) { 795 DeclContext *OuterCtx; 796 bool SearchAfterTemplateScope; 797 llvm::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S); 798 if (SearchAfterTemplateScope) 799 OutsideOfTemplateParamDC = OuterCtx; 800 801 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 802 // We do not directly look into transparent contexts, since 803 // those entities will be found in the nearest enclosing 804 // non-transparent context. 805 if (Ctx->isTransparentContext()) 806 continue; 807 808 // If we have a context, and it's not a context stashed in the 809 // template parameter scope for an out-of-line definition, also 810 // look into that context. 811 if (!(Found && S && S->isTemplateParamScope())) { 812 assert(Ctx->isFileContext() && 813 "We should have been looking only at file context here already."); 814 815 // Look into context considering using-directives. 816 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) 817 Found = true; 818 } 819 820 if (Found) { 821 R.resolveKind(); 822 return true; 823 } 824 825 if (R.isForRedeclaration() && !Ctx->isTransparentContext()) 826 return false; 827 } 828 } 829 830 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext()) 831 return false; 832 } 833 834 return !R.empty(); 835} 836 837/// @brief Perform unqualified name lookup starting from a given 838/// scope. 839/// 840/// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is 841/// used to find names within the current scope. For example, 'x' in 842/// @code 843/// int x; 844/// int f() { 845/// return x; // unqualified name look finds 'x' in the global scope 846/// } 847/// @endcode 848/// 849/// Different lookup criteria can find different names. For example, a 850/// particular scope can have both a struct and a function of the same 851/// name, and each can be found by certain lookup criteria. For more 852/// information about lookup criteria, see the documentation for the 853/// class LookupCriteria. 854/// 855/// @param S The scope from which unqualified name lookup will 856/// begin. If the lookup criteria permits, name lookup may also search 857/// in the parent scopes. 858/// 859/// @param Name The name of the entity that we are searching for. 860/// 861/// @param Loc If provided, the source location where we're performing 862/// name lookup. At present, this is only used to produce diagnostics when 863/// C library functions (like "malloc") are implicitly declared. 864/// 865/// @returns The result of name lookup, which includes zero or more 866/// declarations and possibly additional information used to diagnose 867/// ambiguities. 868bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) { 869 DeclarationName Name = R.getLookupName(); 870 if (!Name) return false; 871 872 LookupNameKind NameKind = R.getLookupKind(); 873 874 if (!getLangOptions().CPlusPlus) { 875 // Unqualified name lookup in C/Objective-C is purely lexical, so 876 // search in the declarations attached to the name. 877 878 if (NameKind == Sema::LookupRedeclarationWithLinkage) { 879 // Find the nearest non-transparent declaration scope. 880 while (!(S->getFlags() & Scope::DeclScope) || 881 (S->getEntity() && 882 static_cast<DeclContext *>(S->getEntity()) 883 ->isTransparentContext())) 884 S = S->getParent(); 885 } 886 887 unsigned IDNS = R.getIdentifierNamespace(); 888 889 // Scan up the scope chain looking for a decl that matches this 890 // identifier that is in the appropriate namespace. This search 891 // should not take long, as shadowing of names is uncommon, and 892 // deep shadowing is extremely uncommon. 893 bool LeftStartingScope = false; 894 895 for (IdentifierResolver::iterator I = IdResolver.begin(Name), 896 IEnd = IdResolver.end(); 897 I != IEnd; ++I) 898 if ((*I)->isInIdentifierNamespace(IDNS)) { 899 if (NameKind == LookupRedeclarationWithLinkage) { 900 // Determine whether this (or a previous) declaration is 901 // out-of-scope. 902 if (!LeftStartingScope && !S->isDeclScope(DeclPtrTy::make(*I))) 903 LeftStartingScope = true; 904 905 // If we found something outside of our starting scope that 906 // does not have linkage, skip it. 907 if (LeftStartingScope && !((*I)->hasLinkage())) 908 continue; 909 } 910 911 R.addDecl(*I); 912 913 if ((*I)->getAttr<OverloadableAttr>()) { 914 // If this declaration has the "overloadable" attribute, we 915 // might have a set of overloaded functions. 916 917 // Figure out what scope the identifier is in. 918 while (!(S->getFlags() & Scope::DeclScope) || 919 !S->isDeclScope(DeclPtrTy::make(*I))) 920 S = S->getParent(); 921 922 // Find the last declaration in this scope (with the same 923 // name, naturally). 924 IdentifierResolver::iterator LastI = I; 925 for (++LastI; LastI != IEnd; ++LastI) { 926 if (!S->isDeclScope(DeclPtrTy::make(*LastI))) 927 break; 928 R.addDecl(*LastI); 929 } 930 } 931 932 R.resolveKind(); 933 934 return true; 935 } 936 } else { 937 // Perform C++ unqualified name lookup. 938 if (CppLookupName(R, S)) 939 return true; 940 } 941 942 // If we didn't find a use of this identifier, and if the identifier 943 // corresponds to a compiler builtin, create the decl object for the builtin 944 // now, injecting it into translation unit scope, and return it. 945 if (AllowBuiltinCreation) 946 return LookupBuiltin(*this, R); 947 948 return false; 949} 950 951/// @brief Perform qualified name lookup in the namespaces nominated by 952/// using directives by the given context. 953/// 954/// C++98 [namespace.qual]p2: 955/// Given X::m (where X is a user-declared namespace), or given ::m 956/// (where X is the global namespace), let S be the set of all 957/// declarations of m in X and in the transitive closure of all 958/// namespaces nominated by using-directives in X and its used 959/// namespaces, except that using-directives are ignored in any 960/// namespace, including X, directly containing one or more 961/// declarations of m. No namespace is searched more than once in 962/// the lookup of a name. If S is the empty set, the program is 963/// ill-formed. Otherwise, if S has exactly one member, or if the 964/// context of the reference is a using-declaration 965/// (namespace.udecl), S is the required set of declarations of 966/// m. Otherwise if the use of m is not one that allows a unique 967/// declaration to be chosen from S, the program is ill-formed. 968/// C++98 [namespace.qual]p5: 969/// During the lookup of a qualified namespace member name, if the 970/// lookup finds more than one declaration of the member, and if one 971/// declaration introduces a class name or enumeration name and the 972/// other declarations either introduce the same object, the same 973/// enumerator or a set of functions, the non-type name hides the 974/// class or enumeration name if and only if the declarations are 975/// from the same namespace; otherwise (the declarations are from 976/// different namespaces), the program is ill-formed. 977static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R, 978 DeclContext *StartDC) { 979 assert(StartDC->isFileContext() && "start context is not a file context"); 980 981 DeclContext::udir_iterator I = StartDC->using_directives_begin(); 982 DeclContext::udir_iterator E = StartDC->using_directives_end(); 983 984 if (I == E) return false; 985 986 // We have at least added all these contexts to the queue. 987 llvm::DenseSet<DeclContext*> Visited; 988 Visited.insert(StartDC); 989 990 // We have not yet looked into these namespaces, much less added 991 // their "using-children" to the queue. 992 llvm::SmallVector<NamespaceDecl*, 8> Queue; 993 994 // We have already looked into the initial namespace; seed the queue 995 // with its using-children. 996 for (; I != E; ++I) { 997 NamespaceDecl *ND = (*I)->getNominatedNamespace()->getOriginalNamespace(); 998 if (Visited.insert(ND).second) 999 Queue.push_back(ND); 1000 } 1001 1002 // The easiest way to implement the restriction in [namespace.qual]p5 1003 // is to check whether any of the individual results found a tag 1004 // and, if so, to declare an ambiguity if the final result is not 1005 // a tag. 1006 bool FoundTag = false; 1007 bool FoundNonTag = false; 1008 1009 LookupResult LocalR(LookupResult::Temporary, R); 1010 1011 bool Found = false; 1012 while (!Queue.empty()) { 1013 NamespaceDecl *ND = Queue.back(); 1014 Queue.pop_back(); 1015 1016 // We go through some convolutions here to avoid copying results 1017 // between LookupResults. 1018 bool UseLocal = !R.empty(); 1019 LookupResult &DirectR = UseLocal ? LocalR : R; 1020 bool FoundDirect = LookupDirect(S, DirectR, ND); 1021 1022 if (FoundDirect) { 1023 // First do any local hiding. 1024 DirectR.resolveKind(); 1025 1026 // If the local result is a tag, remember that. 1027 if (DirectR.isSingleTagDecl()) 1028 FoundTag = true; 1029 else 1030 FoundNonTag = true; 1031 1032 // Append the local results to the total results if necessary. 1033 if (UseLocal) { 1034 R.addAllDecls(LocalR); 1035 LocalR.clear(); 1036 } 1037 } 1038 1039 // If we find names in this namespace, ignore its using directives. 1040 if (FoundDirect) { 1041 Found = true; 1042 continue; 1043 } 1044 1045 for (llvm::tie(I,E) = ND->getUsingDirectives(); I != E; ++I) { 1046 NamespaceDecl *Nom = (*I)->getNominatedNamespace(); 1047 if (Visited.insert(Nom).second) 1048 Queue.push_back(Nom); 1049 } 1050 } 1051 1052 if (Found) { 1053 if (FoundTag && FoundNonTag) 1054 R.setAmbiguousQualifiedTagHiding(); 1055 else 1056 R.resolveKind(); 1057 } 1058 1059 return Found; 1060} 1061 1062/// \brief Perform qualified name lookup into a given context. 1063/// 1064/// Qualified name lookup (C++ [basic.lookup.qual]) is used to find 1065/// names when the context of those names is explicit specified, e.g., 1066/// "std::vector" or "x->member", or as part of unqualified name lookup. 1067/// 1068/// Different lookup criteria can find different names. For example, a 1069/// particular scope can have both a struct and a function of the same 1070/// name, and each can be found by certain lookup criteria. For more 1071/// information about lookup criteria, see the documentation for the 1072/// class LookupCriteria. 1073/// 1074/// \param R captures both the lookup criteria and any lookup results found. 1075/// 1076/// \param LookupCtx The context in which qualified name lookup will 1077/// search. If the lookup criteria permits, name lookup may also search 1078/// in the parent contexts or (for C++ classes) base classes. 1079/// 1080/// \param InUnqualifiedLookup true if this is qualified name lookup that 1081/// occurs as part of unqualified name lookup. 1082/// 1083/// \returns true if lookup succeeded, false if it failed. 1084bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 1085 bool InUnqualifiedLookup) { 1086 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context"); 1087 1088 if (!R.getLookupName()) 1089 return false; 1090 1091 // Make sure that the declaration context is complete. 1092 assert((!isa<TagDecl>(LookupCtx) || 1093 LookupCtx->isDependentContext() || 1094 cast<TagDecl>(LookupCtx)->isDefinition() || 1095 Context.getTypeDeclType(cast<TagDecl>(LookupCtx))->getAs<TagType>() 1096 ->isBeingDefined()) && 1097 "Declaration context must already be complete!"); 1098 1099 // Perform qualified name lookup into the LookupCtx. 1100 if (LookupDirect(*this, R, LookupCtx)) { 1101 R.resolveKind(); 1102 if (isa<CXXRecordDecl>(LookupCtx)) 1103 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx)); 1104 return true; 1105 } 1106 1107 // Don't descend into implied contexts for redeclarations. 1108 // C++98 [namespace.qual]p6: 1109 // In a declaration for a namespace member in which the 1110 // declarator-id is a qualified-id, given that the qualified-id 1111 // for the namespace member has the form 1112 // nested-name-specifier unqualified-id 1113 // the unqualified-id shall name a member of the namespace 1114 // designated by the nested-name-specifier. 1115 // See also [class.mfct]p5 and [class.static.data]p2. 1116 if (R.isForRedeclaration()) 1117 return false; 1118 1119 // If this is a namespace, look it up in the implied namespaces. 1120 if (LookupCtx->isFileContext()) 1121 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx); 1122 1123 // If this isn't a C++ class, we aren't allowed to look into base 1124 // classes, we're done. 1125 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx); 1126 if (!LookupRec) 1127 return false; 1128 1129 // If we're performing qualified name lookup into a dependent class, 1130 // then we are actually looking into a current instantiation. If we have any 1131 // dependent base classes, then we either have to delay lookup until 1132 // template instantiation time (at which point all bases will be available) 1133 // or we have to fail. 1134 if (!InUnqualifiedLookup && LookupRec->isDependentContext() && 1135 LookupRec->hasAnyDependentBases()) { 1136 R.setNotFoundInCurrentInstantiation(); 1137 return false; 1138 } 1139 1140 // Perform lookup into our base classes. 1141 CXXBasePaths Paths; 1142 Paths.setOrigin(LookupRec); 1143 1144 // Look for this member in our base classes 1145 CXXRecordDecl::BaseMatchesCallback *BaseCallback = 0; 1146 switch (R.getLookupKind()) { 1147 case LookupOrdinaryName: 1148 case LookupMemberName: 1149 case LookupRedeclarationWithLinkage: 1150 BaseCallback = &CXXRecordDecl::FindOrdinaryMember; 1151 break; 1152 1153 case LookupTagName: 1154 BaseCallback = &CXXRecordDecl::FindTagMember; 1155 break; 1156 1157 case LookupUsingDeclName: 1158 // This lookup is for redeclarations only. 1159 1160 case LookupOperatorName: 1161 case LookupNamespaceName: 1162 case LookupObjCProtocolName: 1163 // These lookups will never find a member in a C++ class (or base class). 1164 return false; 1165 1166 case LookupNestedNameSpecifierName: 1167 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember; 1168 break; 1169 } 1170 1171 if (!LookupRec->lookupInBases(BaseCallback, 1172 R.getLookupName().getAsOpaquePtr(), Paths)) 1173 return false; 1174 1175 R.setNamingClass(LookupRec); 1176 1177 // C++ [class.member.lookup]p2: 1178 // [...] If the resulting set of declarations are not all from 1179 // sub-objects of the same type, or the set has a nonstatic member 1180 // and includes members from distinct sub-objects, there is an 1181 // ambiguity and the program is ill-formed. Otherwise that set is 1182 // the result of the lookup. 1183 // FIXME: support using declarations! 1184 QualType SubobjectType; 1185 int SubobjectNumber = 0; 1186 AccessSpecifier SubobjectAccess = AS_none; 1187 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); 1188 Path != PathEnd; ++Path) { 1189 const CXXBasePathElement &PathElement = Path->back(); 1190 1191 // Pick the best (i.e. most permissive i.e. numerically lowest) access 1192 // across all paths. 1193 SubobjectAccess = std::min(SubobjectAccess, Path->Access); 1194 1195 // Determine whether we're looking at a distinct sub-object or not. 1196 if (SubobjectType.isNull()) { 1197 // This is the first subobject we've looked at. Record its type. 1198 SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); 1199 SubobjectNumber = PathElement.SubobjectNumber; 1200 } else if (SubobjectType 1201 != Context.getCanonicalType(PathElement.Base->getType())) { 1202 // We found members of the given name in two subobjects of 1203 // different types. This lookup is ambiguous. 1204 R.setAmbiguousBaseSubobjectTypes(Paths); 1205 return true; 1206 } else if (SubobjectNumber != PathElement.SubobjectNumber) { 1207 // We have a different subobject of the same type. 1208 1209 // C++ [class.member.lookup]p5: 1210 // A static member, a nested type or an enumerator defined in 1211 // a base class T can unambiguously be found even if an object 1212 // has more than one base class subobject of type T. 1213 Decl *FirstDecl = *Path->Decls.first; 1214 if (isa<VarDecl>(FirstDecl) || 1215 isa<TypeDecl>(FirstDecl) || 1216 isa<EnumConstantDecl>(FirstDecl)) 1217 continue; 1218 1219 if (isa<CXXMethodDecl>(FirstDecl)) { 1220 // Determine whether all of the methods are static. 1221 bool AllMethodsAreStatic = true; 1222 for (DeclContext::lookup_iterator Func = Path->Decls.first; 1223 Func != Path->Decls.second; ++Func) { 1224 if (!isa<CXXMethodDecl>(*Func)) { 1225 assert(isa<TagDecl>(*Func) && "Non-function must be a tag decl"); 1226 break; 1227 } 1228 1229 if (!cast<CXXMethodDecl>(*Func)->isStatic()) { 1230 AllMethodsAreStatic = false; 1231 break; 1232 } 1233 } 1234 1235 if (AllMethodsAreStatic) 1236 continue; 1237 } 1238 1239 // We have found a nonstatic member name in multiple, distinct 1240 // subobjects. Name lookup is ambiguous. 1241 R.setAmbiguousBaseSubobjects(Paths); 1242 return true; 1243 } 1244 } 1245 1246 // Lookup in a base class succeeded; return these results. 1247 1248 DeclContext::lookup_iterator I, E; 1249 for (llvm::tie(I,E) = Paths.front().Decls; I != E; ++I) { 1250 NamedDecl *D = *I; 1251 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess, 1252 D->getAccess()); 1253 R.addDecl(D, AS); 1254 } 1255 R.resolveKind(); 1256 return true; 1257} 1258 1259/// @brief Performs name lookup for a name that was parsed in the 1260/// source code, and may contain a C++ scope specifier. 1261/// 1262/// This routine is a convenience routine meant to be called from 1263/// contexts that receive a name and an optional C++ scope specifier 1264/// (e.g., "N::M::x"). It will then perform either qualified or 1265/// unqualified name lookup (with LookupQualifiedName or LookupName, 1266/// respectively) on the given name and return those results. 1267/// 1268/// @param S The scope from which unqualified name lookup will 1269/// begin. 1270/// 1271/// @param SS An optional C++ scope-specifier, e.g., "::N::M". 1272/// 1273/// @param Name The name of the entity that name lookup will 1274/// search for. 1275/// 1276/// @param Loc If provided, the source location where we're performing 1277/// name lookup. At present, this is only used to produce diagnostics when 1278/// C library functions (like "malloc") are implicitly declared. 1279/// 1280/// @param EnteringContext Indicates whether we are going to enter the 1281/// context of the scope-specifier SS (if present). 1282/// 1283/// @returns True if any decls were found (but possibly ambiguous) 1284bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS, 1285 bool AllowBuiltinCreation, bool EnteringContext) { 1286 if (SS && SS->isInvalid()) { 1287 // When the scope specifier is invalid, don't even look for 1288 // anything. 1289 return false; 1290 } 1291 1292 if (SS && SS->isSet()) { 1293 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { 1294 // We have resolved the scope specifier to a particular declaration 1295 // contex, and will perform name lookup in that context. 1296 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC)) 1297 return false; 1298 1299 R.setContextRange(SS->getRange()); 1300 1301 return LookupQualifiedName(R, DC); 1302 } 1303 1304 // We could not resolve the scope specified to a specific declaration 1305 // context, which means that SS refers to an unknown specialization. 1306 // Name lookup can't find anything in this case. 1307 return false; 1308 } 1309 1310 // Perform unqualified name lookup starting in the given scope. 1311 return LookupName(R, S, AllowBuiltinCreation); 1312} 1313 1314 1315/// @brief Produce a diagnostic describing the ambiguity that resulted 1316/// from name lookup. 1317/// 1318/// @param Result The ambiguous name lookup result. 1319/// 1320/// @param Name The name of the entity that name lookup was 1321/// searching for. 1322/// 1323/// @param NameLoc The location of the name within the source code. 1324/// 1325/// @param LookupRange A source range that provides more 1326/// source-location information concerning the lookup itself. For 1327/// example, this range might highlight a nested-name-specifier that 1328/// precedes the name. 1329/// 1330/// @returns true 1331bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result) { 1332 assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); 1333 1334 DeclarationName Name = Result.getLookupName(); 1335 SourceLocation NameLoc = Result.getNameLoc(); 1336 SourceRange LookupRange = Result.getContextRange(); 1337 1338 switch (Result.getAmbiguityKind()) { 1339 case LookupResult::AmbiguousBaseSubobjects: { 1340 CXXBasePaths *Paths = Result.getBasePaths(); 1341 QualType SubobjectType = Paths->front().back().Base->getType(); 1342 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) 1343 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) 1344 << LookupRange; 1345 1346 DeclContext::lookup_iterator Found = Paths->front().Decls.first; 1347 while (isa<CXXMethodDecl>(*Found) && 1348 cast<CXXMethodDecl>(*Found)->isStatic()) 1349 ++Found; 1350 1351 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); 1352 1353 return true; 1354 } 1355 1356 case LookupResult::AmbiguousBaseSubobjectTypes: { 1357 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) 1358 << Name << LookupRange; 1359 1360 CXXBasePaths *Paths = Result.getBasePaths(); 1361 std::set<Decl *> DeclsPrinted; 1362 for (CXXBasePaths::paths_iterator Path = Paths->begin(), 1363 PathEnd = Paths->end(); 1364 Path != PathEnd; ++Path) { 1365 Decl *D = *Path->Decls.first; 1366 if (DeclsPrinted.insert(D).second) 1367 Diag(D->getLocation(), diag::note_ambiguous_member_found); 1368 } 1369 1370 return true; 1371 } 1372 1373 case LookupResult::AmbiguousTagHiding: { 1374 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange; 1375 1376 llvm::SmallPtrSet<NamedDecl*,8> TagDecls; 1377 1378 LookupResult::iterator DI, DE = Result.end(); 1379 for (DI = Result.begin(); DI != DE; ++DI) 1380 if (TagDecl *TD = dyn_cast<TagDecl>(*DI)) { 1381 TagDecls.insert(TD); 1382 Diag(TD->getLocation(), diag::note_hidden_tag); 1383 } 1384 1385 for (DI = Result.begin(); DI != DE; ++DI) 1386 if (!isa<TagDecl>(*DI)) 1387 Diag((*DI)->getLocation(), diag::note_hiding_object); 1388 1389 // For recovery purposes, go ahead and implement the hiding. 1390 LookupResult::Filter F = Result.makeFilter(); 1391 while (F.hasNext()) { 1392 if (TagDecls.count(F.next())) 1393 F.erase(); 1394 } 1395 F.done(); 1396 1397 return true; 1398 } 1399 1400 case LookupResult::AmbiguousReference: { 1401 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; 1402 1403 LookupResult::iterator DI = Result.begin(), DE = Result.end(); 1404 for (; DI != DE; ++DI) 1405 Diag((*DI)->getLocation(), diag::note_ambiguous_candidate) << *DI; 1406 1407 return true; 1408 } 1409 } 1410 1411 llvm_unreachable("unknown ambiguity kind"); 1412 return true; 1413} 1414 1415static void 1416addAssociatedClassesAndNamespaces(QualType T, 1417 ASTContext &Context, 1418 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1419 Sema::AssociatedClassSet &AssociatedClasses); 1420 1421static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces, 1422 DeclContext *Ctx) { 1423 // Add the associated namespace for this class. 1424 1425 // We don't use DeclContext::getEnclosingNamespaceContext() as this may 1426 // be a locally scoped record. 1427 1428 while (Ctx->isRecord() || Ctx->isTransparentContext()) 1429 Ctx = Ctx->getParent(); 1430 1431 if (Ctx->isFileContext()) 1432 Namespaces.insert(Ctx->getPrimaryContext()); 1433} 1434 1435// \brief Add the associated classes and namespaces for argument-dependent 1436// lookup that involves a template argument (C++ [basic.lookup.koenig]p2). 1437static void 1438addAssociatedClassesAndNamespaces(const TemplateArgument &Arg, 1439 ASTContext &Context, 1440 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1441 Sema::AssociatedClassSet &AssociatedClasses) { 1442 // C++ [basic.lookup.koenig]p2, last bullet: 1443 // -- [...] ; 1444 switch (Arg.getKind()) { 1445 case TemplateArgument::Null: 1446 break; 1447 1448 case TemplateArgument::Type: 1449 // [...] the namespaces and classes associated with the types of the 1450 // template arguments provided for template type parameters (excluding 1451 // template template parameters) 1452 addAssociatedClassesAndNamespaces(Arg.getAsType(), Context, 1453 AssociatedNamespaces, 1454 AssociatedClasses); 1455 break; 1456 1457 case TemplateArgument::Template: { 1458 // [...] the namespaces in which any template template arguments are 1459 // defined; and the classes in which any member templates used as 1460 // template template arguments are defined. 1461 TemplateName Template = Arg.getAsTemplate(); 1462 if (ClassTemplateDecl *ClassTemplate 1463 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) { 1464 DeclContext *Ctx = ClassTemplate->getDeclContext(); 1465 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1466 AssociatedClasses.insert(EnclosingClass); 1467 // Add the associated namespace for this class. 1468 CollectEnclosingNamespace(AssociatedNamespaces, Ctx); 1469 } 1470 break; 1471 } 1472 1473 case TemplateArgument::Declaration: 1474 case TemplateArgument::Integral: 1475 case TemplateArgument::Expression: 1476 // [Note: non-type template arguments do not contribute to the set of 1477 // associated namespaces. ] 1478 break; 1479 1480 case TemplateArgument::Pack: 1481 for (TemplateArgument::pack_iterator P = Arg.pack_begin(), 1482 PEnd = Arg.pack_end(); 1483 P != PEnd; ++P) 1484 addAssociatedClassesAndNamespaces(*P, Context, 1485 AssociatedNamespaces, 1486 AssociatedClasses); 1487 break; 1488 } 1489} 1490 1491// \brief Add the associated classes and namespaces for 1492// argument-dependent lookup with an argument of class type 1493// (C++ [basic.lookup.koenig]p2). 1494static void 1495addAssociatedClassesAndNamespaces(CXXRecordDecl *Class, 1496 ASTContext &Context, 1497 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1498 Sema::AssociatedClassSet &AssociatedClasses) { 1499 // C++ [basic.lookup.koenig]p2: 1500 // [...] 1501 // -- If T is a class type (including unions), its associated 1502 // classes are: the class itself; the class of which it is a 1503 // member, if any; and its direct and indirect base 1504 // classes. Its associated namespaces are the namespaces in 1505 // which its associated classes are defined. 1506 1507 // Add the class of which it is a member, if any. 1508 DeclContext *Ctx = Class->getDeclContext(); 1509 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1510 AssociatedClasses.insert(EnclosingClass); 1511 // Add the associated namespace for this class. 1512 CollectEnclosingNamespace(AssociatedNamespaces, Ctx); 1513 1514 // Add the class itself. If we've already seen this class, we don't 1515 // need to visit base classes. 1516 if (!AssociatedClasses.insert(Class)) 1517 return; 1518 1519 // -- If T is a template-id, its associated namespaces and classes are 1520 // the namespace in which the template is defined; for member 1521 // templates, the member template’s class; the namespaces and classes 1522 // associated with the types of the template arguments provided for 1523 // template type parameters (excluding template template parameters); the 1524 // namespaces in which any template template arguments are defined; and 1525 // the classes in which any member templates used as template template 1526 // arguments are defined. [Note: non-type template arguments do not 1527 // contribute to the set of associated namespaces. ] 1528 if (ClassTemplateSpecializationDecl *Spec 1529 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) { 1530 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); 1531 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1532 AssociatedClasses.insert(EnclosingClass); 1533 // Add the associated namespace for this class. 1534 CollectEnclosingNamespace(AssociatedNamespaces, Ctx); 1535 1536 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); 1537 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 1538 addAssociatedClassesAndNamespaces(TemplateArgs[I], Context, 1539 AssociatedNamespaces, 1540 AssociatedClasses); 1541 } 1542 1543 // Only recurse into base classes for complete types. 1544 if (!Class->hasDefinition()) { 1545 // FIXME: we might need to instantiate templates here 1546 return; 1547 } 1548 1549 // Add direct and indirect base classes along with their associated 1550 // namespaces. 1551 llvm::SmallVector<CXXRecordDecl *, 32> Bases; 1552 Bases.push_back(Class); 1553 while (!Bases.empty()) { 1554 // Pop this class off the stack. 1555 Class = Bases.back(); 1556 Bases.pop_back(); 1557 1558 // Visit the base classes. 1559 for (CXXRecordDecl::base_class_iterator Base = Class->bases_begin(), 1560 BaseEnd = Class->bases_end(); 1561 Base != BaseEnd; ++Base) { 1562 const RecordType *BaseType = Base->getType()->getAs<RecordType>(); 1563 // In dependent contexts, we do ADL twice, and the first time around, 1564 // the base type might be a dependent TemplateSpecializationType, or a 1565 // TemplateTypeParmType. If that happens, simply ignore it. 1566 // FIXME: If we want to support export, we probably need to add the 1567 // namespace of the template in a TemplateSpecializationType, or even 1568 // the classes and namespaces of known non-dependent arguments. 1569 if (!BaseType) 1570 continue; 1571 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 1572 if (AssociatedClasses.insert(BaseDecl)) { 1573 // Find the associated namespace for this base class. 1574 DeclContext *BaseCtx = BaseDecl->getDeclContext(); 1575 CollectEnclosingNamespace(AssociatedNamespaces, BaseCtx); 1576 1577 // Make sure we visit the bases of this base class. 1578 if (BaseDecl->bases_begin() != BaseDecl->bases_end()) 1579 Bases.push_back(BaseDecl); 1580 } 1581 } 1582 } 1583} 1584 1585// \brief Add the associated classes and namespaces for 1586// argument-dependent lookup with an argument of type T 1587// (C++ [basic.lookup.koenig]p2). 1588static void 1589addAssociatedClassesAndNamespaces(QualType T, 1590 ASTContext &Context, 1591 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1592 Sema::AssociatedClassSet &AssociatedClasses) { 1593 // C++ [basic.lookup.koenig]p2: 1594 // 1595 // For each argument type T in the function call, there is a set 1596 // of zero or more associated namespaces and a set of zero or more 1597 // associated classes to be considered. The sets of namespaces and 1598 // classes is determined entirely by the types of the function 1599 // arguments (and the namespace of any template template 1600 // argument). Typedef names and using-declarations used to specify 1601 // the types do not contribute to this set. The sets of namespaces 1602 // and classes are determined in the following way: 1603 T = Context.getCanonicalType(T).getUnqualifiedType(); 1604 1605 // -- If T is a pointer to U or an array of U, its associated 1606 // namespaces and classes are those associated with U. 1607 // 1608 // We handle this by unwrapping pointer and array types immediately, 1609 // to avoid unnecessary recursion. 1610 while (true) { 1611 if (const PointerType *Ptr = T->getAs<PointerType>()) 1612 T = Ptr->getPointeeType(); 1613 else if (const ArrayType *Ptr = Context.getAsArrayType(T)) 1614 T = Ptr->getElementType(); 1615 else 1616 break; 1617 } 1618 1619 // -- If T is a fundamental type, its associated sets of 1620 // namespaces and classes are both empty. 1621 if (T->getAs<BuiltinType>()) 1622 return; 1623 1624 // -- If T is a class type (including unions), its associated 1625 // classes are: the class itself; the class of which it is a 1626 // member, if any; and its direct and indirect base 1627 // classes. Its associated namespaces are the namespaces in 1628 // which its associated classes are defined. 1629 if (const RecordType *ClassType = T->getAs<RecordType>()) 1630 if (CXXRecordDecl *ClassDecl 1631 = dyn_cast<CXXRecordDecl>(ClassType->getDecl())) { 1632 addAssociatedClassesAndNamespaces(ClassDecl, Context, 1633 AssociatedNamespaces, 1634 AssociatedClasses); 1635 return; 1636 } 1637 1638 // -- If T is an enumeration type, its associated namespace is 1639 // the namespace in which it is defined. If it is class 1640 // member, its associated class is the member’s class; else 1641 // it has no associated class. 1642 if (const EnumType *EnumT = T->getAs<EnumType>()) { 1643 EnumDecl *Enum = EnumT->getDecl(); 1644 1645 DeclContext *Ctx = Enum->getDeclContext(); 1646 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1647 AssociatedClasses.insert(EnclosingClass); 1648 1649 // Add the associated namespace for this class. 1650 CollectEnclosingNamespace(AssociatedNamespaces, Ctx); 1651 1652 return; 1653 } 1654 1655 // -- If T is a function type, its associated namespaces and 1656 // classes are those associated with the function parameter 1657 // types and those associated with the return type. 1658 if (const FunctionType *FnType = T->getAs<FunctionType>()) { 1659 // Return type 1660 addAssociatedClassesAndNamespaces(FnType->getResultType(), 1661 Context, 1662 AssociatedNamespaces, AssociatedClasses); 1663 1664 const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FnType); 1665 if (!Proto) 1666 return; 1667 1668 // Argument types 1669 for (FunctionProtoType::arg_type_iterator Arg = Proto->arg_type_begin(), 1670 ArgEnd = Proto->arg_type_end(); 1671 Arg != ArgEnd; ++Arg) 1672 addAssociatedClassesAndNamespaces(*Arg, Context, 1673 AssociatedNamespaces, AssociatedClasses); 1674 1675 return; 1676 } 1677 1678 // -- If T is a pointer to a member function of a class X, its 1679 // associated namespaces and classes are those associated 1680 // with the function parameter types and return type, 1681 // together with those associated with X. 1682 // 1683 // -- If T is a pointer to a data member of class X, its 1684 // associated namespaces and classes are those associated 1685 // with the member type together with those associated with 1686 // X. 1687 if (const MemberPointerType *MemberPtr = T->getAs<MemberPointerType>()) { 1688 // Handle the type that the pointer to member points to. 1689 addAssociatedClassesAndNamespaces(MemberPtr->getPointeeType(), 1690 Context, 1691 AssociatedNamespaces, 1692 AssociatedClasses); 1693 1694 // Handle the class type into which this points. 1695 if (const RecordType *Class = MemberPtr->getClass()->getAs<RecordType>()) 1696 addAssociatedClassesAndNamespaces(cast<CXXRecordDecl>(Class->getDecl()), 1697 Context, 1698 AssociatedNamespaces, 1699 AssociatedClasses); 1700 1701 return; 1702 } 1703 1704 // FIXME: What about block pointers? 1705 // FIXME: What about Objective-C message sends? 1706} 1707 1708/// \brief Find the associated classes and namespaces for 1709/// argument-dependent lookup for a call with the given set of 1710/// arguments. 1711/// 1712/// This routine computes the sets of associated classes and associated 1713/// namespaces searched by argument-dependent lookup 1714/// (C++ [basic.lookup.argdep]) for a given set of arguments. 1715void 1716Sema::FindAssociatedClassesAndNamespaces(Expr **Args, unsigned NumArgs, 1717 AssociatedNamespaceSet &AssociatedNamespaces, 1718 AssociatedClassSet &AssociatedClasses) { 1719 AssociatedNamespaces.clear(); 1720 AssociatedClasses.clear(); 1721 1722 // C++ [basic.lookup.koenig]p2: 1723 // For each argument type T in the function call, there is a set 1724 // of zero or more associated namespaces and a set of zero or more 1725 // associated classes to be considered. The sets of namespaces and 1726 // classes is determined entirely by the types of the function 1727 // arguments (and the namespace of any template template 1728 // argument). 1729 for (unsigned ArgIdx = 0; ArgIdx != NumArgs; ++ArgIdx) { 1730 Expr *Arg = Args[ArgIdx]; 1731 1732 if (Arg->getType() != Context.OverloadTy) { 1733 addAssociatedClassesAndNamespaces(Arg->getType(), Context, 1734 AssociatedNamespaces, 1735 AssociatedClasses); 1736 continue; 1737 } 1738 1739 // [...] In addition, if the argument is the name or address of a 1740 // set of overloaded functions and/or function templates, its 1741 // associated classes and namespaces are the union of those 1742 // associated with each of the members of the set: the namespace 1743 // in which the function or function template is defined and the 1744 // classes and namespaces associated with its (non-dependent) 1745 // parameter types and return type. 1746 Arg = Arg->IgnoreParens(); 1747 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg)) 1748 if (unaryOp->getOpcode() == UnaryOperator::AddrOf) 1749 Arg = unaryOp->getSubExpr(); 1750 1751 // TODO: avoid the copies. This should be easy when the cases 1752 // share a storage implementation. 1753 llvm::SmallVector<NamedDecl*, 8> Functions; 1754 1755 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg)) 1756 Functions.append(ULE->decls_begin(), ULE->decls_end()); 1757 else 1758 continue; 1759 1760 for (llvm::SmallVectorImpl<NamedDecl*>::iterator I = Functions.begin(), 1761 E = Functions.end(); I != E; ++I) { 1762 // Look through any using declarations to find the underlying function. 1763 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 1764 1765 FunctionDecl *FDecl = dyn_cast<FunctionDecl>(Fn); 1766 if (!FDecl) 1767 FDecl = cast<FunctionTemplateDecl>(Fn)->getTemplatedDecl(); 1768 1769 // Add the classes and namespaces associated with the parameter 1770 // types and return type of this function. 1771 addAssociatedClassesAndNamespaces(FDecl->getType(), Context, 1772 AssociatedNamespaces, 1773 AssociatedClasses); 1774 } 1775 } 1776} 1777 1778/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is 1779/// an acceptable non-member overloaded operator for a call whose 1780/// arguments have types T1 (and, if non-empty, T2). This routine 1781/// implements the check in C++ [over.match.oper]p3b2 concerning 1782/// enumeration types. 1783static bool 1784IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn, 1785 QualType T1, QualType T2, 1786 ASTContext &Context) { 1787 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType())) 1788 return true; 1789 1790 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType())) 1791 return true; 1792 1793 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>(); 1794 if (Proto->getNumArgs() < 1) 1795 return false; 1796 1797 if (T1->isEnumeralType()) { 1798 QualType ArgType = Proto->getArgType(0).getNonReferenceType(); 1799 if (Context.hasSameUnqualifiedType(T1, ArgType)) 1800 return true; 1801 } 1802 1803 if (Proto->getNumArgs() < 2) 1804 return false; 1805 1806 if (!T2.isNull() && T2->isEnumeralType()) { 1807 QualType ArgType = Proto->getArgType(1).getNonReferenceType(); 1808 if (Context.hasSameUnqualifiedType(T2, ArgType)) 1809 return true; 1810 } 1811 1812 return false; 1813} 1814 1815NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name, 1816 SourceLocation Loc, 1817 LookupNameKind NameKind, 1818 RedeclarationKind Redecl) { 1819 LookupResult R(*this, Name, Loc, NameKind, Redecl); 1820 LookupName(R, S); 1821 return R.getAsSingle<NamedDecl>(); 1822} 1823 1824/// \brief Find the protocol with the given name, if any. 1825ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II, 1826 SourceLocation IdLoc) { 1827 Decl *D = LookupSingleName(TUScope, II, IdLoc, 1828 LookupObjCProtocolName); 1829 return cast_or_null<ObjCProtocolDecl>(D); 1830} 1831 1832void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, 1833 QualType T1, QualType T2, 1834 UnresolvedSetImpl &Functions) { 1835 // C++ [over.match.oper]p3: 1836 // -- The set of non-member candidates is the result of the 1837 // unqualified lookup of operator@ in the context of the 1838 // expression according to the usual rules for name lookup in 1839 // unqualified function calls (3.4.2) except that all member 1840 // functions are ignored. However, if no operand has a class 1841 // type, only those non-member functions in the lookup set 1842 // that have a first parameter of type T1 or "reference to 1843 // (possibly cv-qualified) T1", when T1 is an enumeration 1844 // type, or (if there is a right operand) a second parameter 1845 // of type T2 or "reference to (possibly cv-qualified) T2", 1846 // when T2 is an enumeration type, are candidate functions. 1847 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 1848 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName); 1849 LookupName(Operators, S); 1850 1851 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); 1852 1853 if (Operators.empty()) 1854 return; 1855 1856 for (LookupResult::iterator Op = Operators.begin(), OpEnd = Operators.end(); 1857 Op != OpEnd; ++Op) { 1858 NamedDecl *Found = (*Op)->getUnderlyingDecl(); 1859 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Found)) { 1860 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context)) 1861 Functions.addDecl(*Op, Op.getAccess()); // FIXME: canonical FD 1862 } else if (FunctionTemplateDecl *FunTmpl 1863 = dyn_cast<FunctionTemplateDecl>(Found)) { 1864 // FIXME: friend operators? 1865 // FIXME: do we need to check IsAcceptableNonMemberOperatorCandidate, 1866 // later? 1867 if (!FunTmpl->getDeclContext()->isRecord()) 1868 Functions.addDecl(*Op, Op.getAccess()); 1869 } 1870 } 1871} 1872 1873void ADLResult::insert(NamedDecl *New) { 1874 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())]; 1875 1876 // If we haven't yet seen a decl for this key, or the last decl 1877 // was exactly this one, we're done. 1878 if (Old == 0 || Old == New) { 1879 Old = New; 1880 return; 1881 } 1882 1883 // Otherwise, decide which is a more recent redeclaration. 1884 FunctionDecl *OldFD, *NewFD; 1885 if (isa<FunctionTemplateDecl>(New)) { 1886 OldFD = cast<FunctionTemplateDecl>(Old)->getTemplatedDecl(); 1887 NewFD = cast<FunctionTemplateDecl>(New)->getTemplatedDecl(); 1888 } else { 1889 OldFD = cast<FunctionDecl>(Old); 1890 NewFD = cast<FunctionDecl>(New); 1891 } 1892 1893 FunctionDecl *Cursor = NewFD; 1894 while (true) { 1895 Cursor = Cursor->getPreviousDeclaration(); 1896 1897 // If we got to the end without finding OldFD, OldFD is the newer 1898 // declaration; leave things as they are. 1899 if (!Cursor) return; 1900 1901 // If we do find OldFD, then NewFD is newer. 1902 if (Cursor == OldFD) break; 1903 1904 // Otherwise, keep looking. 1905 } 1906 1907 Old = New; 1908} 1909 1910void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator, 1911 Expr **Args, unsigned NumArgs, 1912 ADLResult &Result) { 1913 // Find all of the associated namespaces and classes based on the 1914 // arguments we have. 1915 AssociatedNamespaceSet AssociatedNamespaces; 1916 AssociatedClassSet AssociatedClasses; 1917 FindAssociatedClassesAndNamespaces(Args, NumArgs, 1918 AssociatedNamespaces, 1919 AssociatedClasses); 1920 1921 QualType T1, T2; 1922 if (Operator) { 1923 T1 = Args[0]->getType(); 1924 if (NumArgs >= 2) 1925 T2 = Args[1]->getType(); 1926 } 1927 1928 // C++ [basic.lookup.argdep]p3: 1929 // Let X be the lookup set produced by unqualified lookup (3.4.1) 1930 // and let Y be the lookup set produced by argument dependent 1931 // lookup (defined as follows). If X contains [...] then Y is 1932 // empty. Otherwise Y is the set of declarations found in the 1933 // namespaces associated with the argument types as described 1934 // below. The set of declarations found by the lookup of the name 1935 // is the union of X and Y. 1936 // 1937 // Here, we compute Y and add its members to the overloaded 1938 // candidate set. 1939 for (AssociatedNamespaceSet::iterator NS = AssociatedNamespaces.begin(), 1940 NSEnd = AssociatedNamespaces.end(); 1941 NS != NSEnd; ++NS) { 1942 // When considering an associated namespace, the lookup is the 1943 // same as the lookup performed when the associated namespace is 1944 // used as a qualifier (3.4.3.2) except that: 1945 // 1946 // -- Any using-directives in the associated namespace are 1947 // ignored. 1948 // 1949 // -- Any namespace-scope friend functions declared in 1950 // associated classes are visible within their respective 1951 // namespaces even if they are not visible during an ordinary 1952 // lookup (11.4). 1953 DeclContext::lookup_iterator I, E; 1954 for (llvm::tie(I, E) = (*NS)->lookup(Name); I != E; ++I) { 1955 NamedDecl *D = *I; 1956 // If the only declaration here is an ordinary friend, consider 1957 // it only if it was declared in an associated classes. 1958 if (D->getIdentifierNamespace() == Decl::IDNS_OrdinaryFriend) { 1959 DeclContext *LexDC = D->getLexicalDeclContext(); 1960 if (!AssociatedClasses.count(cast<CXXRecordDecl>(LexDC))) 1961 continue; 1962 } 1963 1964 if (isa<UsingShadowDecl>(D)) 1965 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1966 1967 if (isa<FunctionDecl>(D)) { 1968 if (Operator && 1969 !IsAcceptableNonMemberOperatorCandidate(cast<FunctionDecl>(D), 1970 T1, T2, Context)) 1971 continue; 1972 } else if (!isa<FunctionTemplateDecl>(D)) 1973 continue; 1974 1975 Result.insert(D); 1976 } 1977 } 1978} 1979 1980//---------------------------------------------------------------------------- 1981// Search for all visible declarations. 1982//---------------------------------------------------------------------------- 1983VisibleDeclConsumer::~VisibleDeclConsumer() { } 1984 1985namespace { 1986 1987class ShadowContextRAII; 1988 1989class VisibleDeclsRecord { 1990public: 1991 /// \brief An entry in the shadow map, which is optimized to store a 1992 /// single declaration (the common case) but can also store a list 1993 /// of declarations. 1994 class ShadowMapEntry { 1995 typedef llvm::SmallVector<NamedDecl *, 4> DeclVector; 1996 1997 /// \brief Contains either the solitary NamedDecl * or a vector 1998 /// of declarations. 1999 llvm::PointerUnion<NamedDecl *, DeclVector*> DeclOrVector; 2000 2001 public: 2002 ShadowMapEntry() : DeclOrVector() { } 2003 2004 void Add(NamedDecl *ND); 2005 void Destroy(); 2006 2007 // Iteration. 2008 typedef NamedDecl **iterator; 2009 iterator begin(); 2010 iterator end(); 2011 }; 2012 2013private: 2014 /// \brief A mapping from declaration names to the declarations that have 2015 /// this name within a particular scope. 2016 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap; 2017 2018 /// \brief A list of shadow maps, which is used to model name hiding. 2019 std::list<ShadowMap> ShadowMaps; 2020 2021 /// \brief The declaration contexts we have already visited. 2022 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts; 2023 2024 friend class ShadowContextRAII; 2025 2026public: 2027 /// \brief Determine whether we have already visited this context 2028 /// (and, if not, note that we are going to visit that context now). 2029 bool visitedContext(DeclContext *Ctx) { 2030 return !VisitedContexts.insert(Ctx); 2031 } 2032 2033 /// \brief Determine whether the given declaration is hidden in the 2034 /// current scope. 2035 /// 2036 /// \returns the declaration that hides the given declaration, or 2037 /// NULL if no such declaration exists. 2038 NamedDecl *checkHidden(NamedDecl *ND); 2039 2040 /// \brief Add a declaration to the current shadow map. 2041 void add(NamedDecl *ND) { ShadowMaps.back()[ND->getDeclName()].Add(ND); } 2042}; 2043 2044/// \brief RAII object that records when we've entered a shadow context. 2045class ShadowContextRAII { 2046 VisibleDeclsRecord &Visible; 2047 2048 typedef VisibleDeclsRecord::ShadowMap ShadowMap; 2049 2050public: 2051 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) { 2052 Visible.ShadowMaps.push_back(ShadowMap()); 2053 } 2054 2055 ~ShadowContextRAII() { 2056 for (ShadowMap::iterator E = Visible.ShadowMaps.back().begin(), 2057 EEnd = Visible.ShadowMaps.back().end(); 2058 E != EEnd; 2059 ++E) 2060 E->second.Destroy(); 2061 2062 Visible.ShadowMaps.pop_back(); 2063 } 2064}; 2065 2066} // end anonymous namespace 2067 2068void VisibleDeclsRecord::ShadowMapEntry::Add(NamedDecl *ND) { 2069 if (DeclOrVector.isNull()) { 2070 // 0 - > 1 elements: just set the single element information. 2071 DeclOrVector = ND; 2072 return; 2073 } 2074 2075 if (NamedDecl *PrevND = DeclOrVector.dyn_cast<NamedDecl *>()) { 2076 // 1 -> 2 elements: create the vector of results and push in the 2077 // existing declaration. 2078 DeclVector *Vec = new DeclVector; 2079 Vec->push_back(PrevND); 2080 DeclOrVector = Vec; 2081 } 2082 2083 // Add the new element to the end of the vector. 2084 DeclOrVector.get<DeclVector*>()->push_back(ND); 2085} 2086 2087void VisibleDeclsRecord::ShadowMapEntry::Destroy() { 2088 if (DeclVector *Vec = DeclOrVector.dyn_cast<DeclVector *>()) { 2089 delete Vec; 2090 DeclOrVector = ((NamedDecl *)0); 2091 } 2092} 2093 2094VisibleDeclsRecord::ShadowMapEntry::iterator 2095VisibleDeclsRecord::ShadowMapEntry::begin() { 2096 if (DeclOrVector.isNull()) 2097 return 0; 2098 2099 if (DeclOrVector.dyn_cast<NamedDecl *>()) 2100 return &reinterpret_cast<NamedDecl*&>(DeclOrVector); 2101 2102 return DeclOrVector.get<DeclVector *>()->begin(); 2103} 2104 2105VisibleDeclsRecord::ShadowMapEntry::iterator 2106VisibleDeclsRecord::ShadowMapEntry::end() { 2107 if (DeclOrVector.isNull()) 2108 return 0; 2109 2110 if (DeclOrVector.dyn_cast<NamedDecl *>()) 2111 return &reinterpret_cast<NamedDecl*&>(DeclOrVector) + 1; 2112 2113 return DeclOrVector.get<DeclVector *>()->end(); 2114} 2115 2116NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) { 2117 // Look through using declarations. 2118 ND = ND->getUnderlyingDecl(); 2119 2120 unsigned IDNS = ND->getIdentifierNamespace(); 2121 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin(); 2122 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend(); 2123 SM != SMEnd; ++SM) { 2124 ShadowMap::iterator Pos = SM->find(ND->getDeclName()); 2125 if (Pos == SM->end()) 2126 continue; 2127 2128 for (ShadowMapEntry::iterator I = Pos->second.begin(), 2129 IEnd = Pos->second.end(); 2130 I != IEnd; ++I) { 2131 // A tag declaration does not hide a non-tag declaration. 2132 if ((*I)->hasTagIdentifierNamespace() && 2133 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary | 2134 Decl::IDNS_ObjCProtocol))) 2135 continue; 2136 2137 // Protocols are in distinct namespaces from everything else. 2138 if ((((*I)->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol) 2139 || (IDNS & Decl::IDNS_ObjCProtocol)) && 2140 (*I)->getIdentifierNamespace() != IDNS) 2141 continue; 2142 2143 // Functions and function templates in the same scope overload 2144 // rather than hide. FIXME: Look for hiding based on function 2145 // signatures! 2146 if ((*I)->isFunctionOrFunctionTemplate() && 2147 ND->isFunctionOrFunctionTemplate() && 2148 SM == ShadowMaps.rbegin()) 2149 continue; 2150 2151 // We've found a declaration that hides this one. 2152 return *I; 2153 } 2154 } 2155 2156 return 0; 2157} 2158 2159static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result, 2160 bool QualifiedNameLookup, 2161 bool InBaseClass, 2162 VisibleDeclConsumer &Consumer, 2163 VisibleDeclsRecord &Visited) { 2164 if (!Ctx) 2165 return; 2166 2167 // Make sure we don't visit the same context twice. 2168 if (Visited.visitedContext(Ctx->getPrimaryContext())) 2169 return; 2170 2171 // Enumerate all of the results in this context. 2172 for (DeclContext *CurCtx = Ctx->getPrimaryContext(); CurCtx; 2173 CurCtx = CurCtx->getNextContext()) { 2174 for (DeclContext::decl_iterator D = CurCtx->decls_begin(), 2175 DEnd = CurCtx->decls_end(); 2176 D != DEnd; ++D) { 2177 if (NamedDecl *ND = dyn_cast<NamedDecl>(*D)) 2178 if (Result.isAcceptableDecl(ND)) { 2179 Consumer.FoundDecl(ND, Visited.checkHidden(ND), InBaseClass); 2180 Visited.add(ND); 2181 } 2182 2183 // Visit transparent contexts inside this context. 2184 if (DeclContext *InnerCtx = dyn_cast<DeclContext>(*D)) { 2185 if (InnerCtx->isTransparentContext()) 2186 LookupVisibleDecls(InnerCtx, Result, QualifiedNameLookup, InBaseClass, 2187 Consumer, Visited); 2188 } 2189 } 2190 } 2191 2192 // Traverse using directives for qualified name lookup. 2193 if (QualifiedNameLookup) { 2194 ShadowContextRAII Shadow(Visited); 2195 DeclContext::udir_iterator I, E; 2196 for (llvm::tie(I, E) = Ctx->getUsingDirectives(); I != E; ++I) { 2197 LookupVisibleDecls((*I)->getNominatedNamespace(), Result, 2198 QualifiedNameLookup, InBaseClass, Consumer, Visited); 2199 } 2200 } 2201 2202 // Traverse the contexts of inherited C++ classes. 2203 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) { 2204 if (!Record->hasDefinition()) 2205 return; 2206 2207 for (CXXRecordDecl::base_class_iterator B = Record->bases_begin(), 2208 BEnd = Record->bases_end(); 2209 B != BEnd; ++B) { 2210 QualType BaseType = B->getType(); 2211 2212 // Don't look into dependent bases, because name lookup can't look 2213 // there anyway. 2214 if (BaseType->isDependentType()) 2215 continue; 2216 2217 const RecordType *Record = BaseType->getAs<RecordType>(); 2218 if (!Record) 2219 continue; 2220 2221 // FIXME: It would be nice to be able to determine whether referencing 2222 // a particular member would be ambiguous. For example, given 2223 // 2224 // struct A { int member; }; 2225 // struct B { int member; }; 2226 // struct C : A, B { }; 2227 // 2228 // void f(C *c) { c->### } 2229 // 2230 // accessing 'member' would result in an ambiguity. However, we 2231 // could be smart enough to qualify the member with the base 2232 // class, e.g., 2233 // 2234 // c->B::member 2235 // 2236 // or 2237 // 2238 // c->A::member 2239 2240 // Find results in this base class (and its bases). 2241 ShadowContextRAII Shadow(Visited); 2242 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup, 2243 true, Consumer, Visited); 2244 } 2245 } 2246 2247 // Traverse the contexts of Objective-C classes. 2248 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) { 2249 // Traverse categories. 2250 for (ObjCCategoryDecl *Category = IFace->getCategoryList(); 2251 Category; Category = Category->getNextClassCategory()) { 2252 ShadowContextRAII Shadow(Visited); 2253 LookupVisibleDecls(Category, Result, QualifiedNameLookup, false, 2254 Consumer, Visited); 2255 } 2256 2257 // Traverse protocols. 2258 for (ObjCInterfaceDecl::protocol_iterator I = IFace->protocol_begin(), 2259 E = IFace->protocol_end(); I != E; ++I) { 2260 ShadowContextRAII Shadow(Visited); 2261 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2262 Visited); 2263 } 2264 2265 // Traverse the superclass. 2266 if (IFace->getSuperClass()) { 2267 ShadowContextRAII Shadow(Visited); 2268 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup, 2269 true, Consumer, Visited); 2270 } 2271 2272 // If there is an implementation, traverse it. We do this to find 2273 // synthesized ivars. 2274 if (IFace->getImplementation()) { 2275 ShadowContextRAII Shadow(Visited); 2276 LookupVisibleDecls(IFace->getImplementation(), Result, 2277 QualifiedNameLookup, 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 // If there is an implementation, traverse it. 2295 if (Category->getImplementation()) { 2296 ShadowContextRAII Shadow(Visited); 2297 LookupVisibleDecls(Category->getImplementation(), Result, 2298 QualifiedNameLookup, true, Consumer, Visited); 2299 } 2300 } 2301} 2302 2303static void LookupVisibleDecls(Scope *S, LookupResult &Result, 2304 UnqualUsingDirectiveSet &UDirs, 2305 VisibleDeclConsumer &Consumer, 2306 VisibleDeclsRecord &Visited) { 2307 if (!S) 2308 return; 2309 2310 if (!S->getEntity() || !S->getParent() || 2311 ((DeclContext *)S->getEntity())->isFunctionOrMethod()) { 2312 // Walk through the declarations in this Scope. 2313 for (Scope::decl_iterator D = S->decl_begin(), DEnd = S->decl_end(); 2314 D != DEnd; ++D) { 2315 if (NamedDecl *ND = dyn_cast<NamedDecl>((Decl *)((*D).get()))) 2316 if (Result.isAcceptableDecl(ND)) { 2317 Consumer.FoundDecl(ND, Visited.checkHidden(ND), false); 2318 Visited.add(ND); 2319 } 2320 } 2321 } 2322 2323 // FIXME: C++ [temp.local]p8 2324 DeclContext *Entity = 0; 2325 if (S->getEntity()) { 2326 // Look into this scope's declaration context, along with any of its 2327 // parent lookup contexts (e.g., enclosing classes), up to the point 2328 // where we hit the context stored in the next outer scope. 2329 Entity = (DeclContext *)S->getEntity(); 2330 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME 2331 2332 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx); 2333 Ctx = Ctx->getLookupParent()) { 2334 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 2335 if (Method->isInstanceMethod()) { 2336 // For instance methods, look for ivars in the method's interface. 2337 LookupResult IvarResult(Result.getSema(), Result.getLookupName(), 2338 Result.getNameLoc(), Sema::LookupMemberName); 2339 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) 2340 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false, 2341 /*InBaseClass=*/false, Consumer, Visited); 2342 } 2343 2344 // We've already performed all of the name lookup that we need 2345 // to for Objective-C methods; the next context will be the 2346 // outer scope. 2347 break; 2348 } 2349 2350 if (Ctx->isFunctionOrMethod()) 2351 continue; 2352 2353 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false, 2354 /*InBaseClass=*/false, Consumer, Visited); 2355 } 2356 } else if (!S->getParent()) { 2357 // Look into the translation unit scope. We walk through the translation 2358 // unit's declaration context, because the Scope itself won't have all of 2359 // the declarations if we loaded a precompiled header. 2360 // FIXME: We would like the translation unit's Scope object to point to the 2361 // translation unit, so we don't need this special "if" branch. However, 2362 // doing so would force the normal C++ name-lookup code to look into the 2363 // translation unit decl when the IdentifierInfo chains would suffice. 2364 // Once we fix that problem (which is part of a more general "don't look 2365 // in DeclContexts unless we have to" optimization), we can eliminate this. 2366 Entity = Result.getSema().Context.getTranslationUnitDecl(); 2367 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false, 2368 /*InBaseClass=*/false, Consumer, Visited); 2369 } 2370 2371 if (Entity) { 2372 // Lookup visible declarations in any namespaces found by using 2373 // directives. 2374 UnqualUsingDirectiveSet::const_iterator UI, UEnd; 2375 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(Entity); 2376 for (; UI != UEnd; ++UI) 2377 LookupVisibleDecls(const_cast<DeclContext *>(UI->getNominatedNamespace()), 2378 Result, /*QualifiedNameLookup=*/false, 2379 /*InBaseClass=*/false, Consumer, Visited); 2380 } 2381 2382 // Lookup names in the parent scope. 2383 ShadowContextRAII Shadow(Visited); 2384 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited); 2385} 2386 2387void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind, 2388 VisibleDeclConsumer &Consumer) { 2389 // Determine the set of using directives available during 2390 // unqualified name lookup. 2391 Scope *Initial = S; 2392 UnqualUsingDirectiveSet UDirs; 2393 if (getLangOptions().CPlusPlus) { 2394 // Find the first namespace or translation-unit scope. 2395 while (S && !isNamespaceOrTranslationUnitScope(S)) 2396 S = S->getParent(); 2397 2398 UDirs.visitScopeChain(Initial, S); 2399 } 2400 UDirs.done(); 2401 2402 // Look for visible declarations. 2403 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2404 VisibleDeclsRecord Visited; 2405 ShadowContextRAII Shadow(Visited); 2406 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited); 2407} 2408 2409void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind, 2410 VisibleDeclConsumer &Consumer) { 2411 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2412 VisibleDeclsRecord Visited; 2413 ShadowContextRAII Shadow(Visited); 2414 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true, 2415 /*InBaseClass=*/false, Consumer, Visited); 2416} 2417 2418//---------------------------------------------------------------------------- 2419// Typo correction 2420//---------------------------------------------------------------------------- 2421 2422namespace { 2423class TypoCorrectionConsumer : public VisibleDeclConsumer { 2424 /// \brief The name written that is a typo in the source. 2425 llvm::StringRef Typo; 2426 2427 /// \brief The results found that have the smallest edit distance 2428 /// found (so far) with the typo name. 2429 llvm::SmallVector<NamedDecl *, 4> BestResults; 2430 2431 /// \brief The keywords that have the smallest edit distance. 2432 llvm::SmallVector<IdentifierInfo *, 4> BestKeywords; 2433 2434 /// \brief The best edit distance found so far. 2435 unsigned BestEditDistance; 2436 2437public: 2438 explicit TypoCorrectionConsumer(IdentifierInfo *Typo) 2439 : Typo(Typo->getName()) { } 2440 2441 virtual void FoundDecl(NamedDecl *ND, NamedDecl *Hiding, bool InBaseClass); 2442 void addKeywordResult(ASTContext &Context, llvm::StringRef Keyword); 2443 2444 typedef llvm::SmallVector<NamedDecl *, 4>::const_iterator iterator; 2445 iterator begin() const { return BestResults.begin(); } 2446 iterator end() const { return BestResults.end(); } 2447 void clear_decls() { BestResults.clear(); } 2448 2449 bool empty() const { return BestResults.empty() && BestKeywords.empty(); } 2450 2451 typedef llvm::SmallVector<IdentifierInfo *, 4>::const_iterator 2452 keyword_iterator; 2453 keyword_iterator keyword_begin() const { return BestKeywords.begin(); } 2454 keyword_iterator keyword_end() const { return BestKeywords.end(); } 2455 bool keyword_empty() const { return BestKeywords.empty(); } 2456 unsigned keyword_size() const { return BestKeywords.size(); } 2457 2458 unsigned getBestEditDistance() const { return BestEditDistance; } 2459}; 2460 2461} 2462 2463void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding, 2464 bool InBaseClass) { 2465 // Don't consider hidden names for typo correction. 2466 if (Hiding) 2467 return; 2468 2469 // Only consider entities with identifiers for names, ignoring 2470 // special names (constructors, overloaded operators, selectors, 2471 // etc.). 2472 IdentifierInfo *Name = ND->getIdentifier(); 2473 if (!Name) 2474 return; 2475 2476 // Compute the edit distance between the typo and the name of this 2477 // entity. If this edit distance is not worse than the best edit 2478 // distance we've seen so far, add it to the list of results. 2479 unsigned ED = Typo.edit_distance(Name->getName()); 2480 if (!BestResults.empty() || !BestKeywords.empty()) { 2481 if (ED < BestEditDistance) { 2482 // This result is better than any we've seen before; clear out 2483 // the previous results. 2484 BestResults.clear(); 2485 BestKeywords.clear(); 2486 BestEditDistance = ED; 2487 } else if (ED > BestEditDistance) { 2488 // This result is worse than the best results we've seen so far; 2489 // ignore it. 2490 return; 2491 } 2492 } else 2493 BestEditDistance = ED; 2494 2495 BestResults.push_back(ND); 2496} 2497 2498void TypoCorrectionConsumer::addKeywordResult(ASTContext &Context, 2499 llvm::StringRef Keyword) { 2500 // Compute the edit distance between the typo and this keyword. 2501 // If this edit distance is not worse than the best edit 2502 // distance we've seen so far, add it to the list of results. 2503 unsigned ED = Typo.edit_distance(Keyword); 2504 if (!BestResults.empty() || !BestKeywords.empty()) { 2505 if (ED < BestEditDistance) { 2506 BestResults.clear(); 2507 BestKeywords.clear(); 2508 BestEditDistance = ED; 2509 } else if (ED > BestEditDistance) { 2510 // This result is worse than the best results we've seen so far; 2511 // ignore it. 2512 return; 2513 } 2514 } else 2515 BestEditDistance = ED; 2516 2517 BestKeywords.push_back(&Context.Idents.get(Keyword)); 2518} 2519 2520/// \brief Try to "correct" a typo in the source code by finding 2521/// visible declarations whose names are similar to the name that was 2522/// present in the source code. 2523/// 2524/// \param Res the \c LookupResult structure that contains the name 2525/// that was present in the source code along with the name-lookup 2526/// criteria used to search for the name. On success, this structure 2527/// will contain the results of name lookup. 2528/// 2529/// \param S the scope in which name lookup occurs. 2530/// 2531/// \param SS the nested-name-specifier that precedes the name we're 2532/// looking for, if present. 2533/// 2534/// \param MemberContext if non-NULL, the context in which to look for 2535/// a member access expression. 2536/// 2537/// \param EnteringContext whether we're entering the context described by 2538/// the nested-name-specifier SS. 2539/// 2540/// \param CTC The context in which typo correction occurs, which impacts the 2541/// set of keywords permitted. 2542/// 2543/// \param OPT when non-NULL, the search for visible declarations will 2544/// also walk the protocols in the qualified interfaces of \p OPT. 2545/// 2546/// \returns the corrected name if the typo was corrected, otherwise returns an 2547/// empty \c DeclarationName. When a typo was corrected, the result structure 2548/// may contain the results of name lookup for the correct name or it may be 2549/// empty. 2550DeclarationName Sema::CorrectTypo(LookupResult &Res, Scope *S, CXXScopeSpec *SS, 2551 DeclContext *MemberContext, 2552 bool EnteringContext, 2553 CorrectTypoContext CTC, 2554 const ObjCObjectPointerType *OPT) { 2555 if (Diags.hasFatalErrorOccurred()) 2556 return DeclarationName(); 2557 2558 // Provide a stop gap for files that are just seriously broken. Trying 2559 // to correct all typos can turn into a HUGE performance penalty, causing 2560 // some files to take minutes to get rejected by the parser. 2561 // FIXME: Is this the right solution? 2562 if (TyposCorrected == 20) 2563 return DeclarationName(); 2564 ++TyposCorrected; 2565 2566 // We only attempt to correct typos for identifiers. 2567 IdentifierInfo *Typo = Res.getLookupName().getAsIdentifierInfo(); 2568 if (!Typo) 2569 return DeclarationName(); 2570 2571 // If the scope specifier itself was invalid, don't try to correct 2572 // typos. 2573 if (SS && SS->isInvalid()) 2574 return DeclarationName(); 2575 2576 // Never try to correct typos during template deduction or 2577 // instantiation. 2578 if (!ActiveTemplateInstantiations.empty()) 2579 return DeclarationName(); 2580 2581 TypoCorrectionConsumer Consumer(Typo); 2582 2583 // Perform name lookup to find visible, similarly-named entities. 2584 if (MemberContext) { 2585 LookupVisibleDecls(MemberContext, Res.getLookupKind(), Consumer); 2586 2587 // Look in qualified interfaces. 2588 if (OPT) { 2589 for (ObjCObjectPointerType::qual_iterator 2590 I = OPT->qual_begin(), E = OPT->qual_end(); 2591 I != E; ++I) 2592 LookupVisibleDecls(*I, Res.getLookupKind(), Consumer); 2593 } 2594 } else if (SS && SS->isSet()) { 2595 DeclContext *DC = computeDeclContext(*SS, EnteringContext); 2596 if (!DC) 2597 return DeclarationName(); 2598 2599 LookupVisibleDecls(DC, Res.getLookupKind(), Consumer); 2600 } else { 2601 LookupVisibleDecls(S, Res.getLookupKind(), Consumer); 2602 } 2603 2604 // Add context-dependent keywords. 2605 bool WantTypeSpecifiers = false; 2606 bool WantExpressionKeywords = false; 2607 bool WantCXXNamedCasts = false; 2608 bool WantRemainingKeywords = false; 2609 switch (CTC) { 2610 case CTC_Unknown: 2611 WantTypeSpecifiers = true; 2612 WantExpressionKeywords = true; 2613 WantCXXNamedCasts = true; 2614 WantRemainingKeywords = true; 2615 break; 2616 2617 case CTC_NoKeywords: 2618 break; 2619 2620 case CTC_Type: 2621 WantTypeSpecifiers = true; 2622 break; 2623 2624 case CTC_ObjCMessageReceiver: 2625 Consumer.addKeywordResult(Context, "super"); 2626 // Fall through to handle message receivers like expressions. 2627 2628 case CTC_Expression: 2629 if (getLangOptions().CPlusPlus) 2630 WantTypeSpecifiers = true; 2631 WantExpressionKeywords = true; 2632 // Fall through to get C++ named casts. 2633 2634 case CTC_CXXCasts: 2635 WantCXXNamedCasts = true; 2636 break; 2637 2638 case CTC_MemberLookup: 2639 if (getLangOptions().CPlusPlus) 2640 Consumer.addKeywordResult(Context, "template"); 2641 break; 2642 } 2643 2644 if (WantTypeSpecifiers) { 2645 // Add type-specifier keywords to the set of results. 2646 const char *CTypeSpecs[] = { 2647 "char", "const", "double", "enum", "float", "int", "long", "short", 2648 "signed", "struct", "union", "unsigned", "void", "volatile", "_Bool", 2649 "_Complex", "_Imaginary", 2650 // storage-specifiers as well 2651 "extern", "inline", "static", "typedef" 2652 }; 2653 2654 const unsigned NumCTypeSpecs = sizeof(CTypeSpecs) / sizeof(CTypeSpecs[0]); 2655 for (unsigned I = 0; I != NumCTypeSpecs; ++I) 2656 Consumer.addKeywordResult(Context, CTypeSpecs[I]); 2657 2658 if (getLangOptions().C99) 2659 Consumer.addKeywordResult(Context, "restrict"); 2660 if (getLangOptions().Bool || getLangOptions().CPlusPlus) 2661 Consumer.addKeywordResult(Context, "bool"); 2662 2663 if (getLangOptions().CPlusPlus) { 2664 Consumer.addKeywordResult(Context, "class"); 2665 Consumer.addKeywordResult(Context, "typename"); 2666 Consumer.addKeywordResult(Context, "wchar_t"); 2667 2668 if (getLangOptions().CPlusPlus0x) { 2669 Consumer.addKeywordResult(Context, "char16_t"); 2670 Consumer.addKeywordResult(Context, "char32_t"); 2671 Consumer.addKeywordResult(Context, "constexpr"); 2672 Consumer.addKeywordResult(Context, "decltype"); 2673 Consumer.addKeywordResult(Context, "thread_local"); 2674 } 2675 } 2676 2677 if (getLangOptions().GNUMode) 2678 Consumer.addKeywordResult(Context, "typeof"); 2679 } 2680 2681 if (WantCXXNamedCasts) { 2682 Consumer.addKeywordResult(Context, "const_cast"); 2683 Consumer.addKeywordResult(Context, "dynamic_cast"); 2684 Consumer.addKeywordResult(Context, "reinterpret_cast"); 2685 Consumer.addKeywordResult(Context, "static_cast"); 2686 } 2687 2688 if (WantExpressionKeywords) { 2689 Consumer.addKeywordResult(Context, "sizeof"); 2690 if (getLangOptions().Bool || getLangOptions().CPlusPlus) { 2691 Consumer.addKeywordResult(Context, "false"); 2692 Consumer.addKeywordResult(Context, "true"); 2693 } 2694 2695 if (getLangOptions().CPlusPlus) { 2696 const char *CXXExprs[] = { 2697 "delete", "new", "operator", "throw", "typeid" 2698 }; 2699 const unsigned NumCXXExprs = sizeof(CXXExprs) / sizeof(CXXExprs[0]); 2700 for (unsigned I = 0; I != NumCXXExprs; ++I) 2701 Consumer.addKeywordResult(Context, CXXExprs[I]); 2702 2703 if (isa<CXXMethodDecl>(CurContext) && 2704 cast<CXXMethodDecl>(CurContext)->isInstance()) 2705 Consumer.addKeywordResult(Context, "this"); 2706 2707 if (getLangOptions().CPlusPlus0x) { 2708 Consumer.addKeywordResult(Context, "alignof"); 2709 Consumer.addKeywordResult(Context, "nullptr"); 2710 } 2711 } 2712 } 2713 2714 if (WantRemainingKeywords) { 2715 if (getCurFunctionOrMethodDecl() || getCurBlock()) { 2716 // Statements. 2717 const char *CStmts[] = { 2718 "do", "else", "for", "goto", "if", "return", "switch", "while" }; 2719 const unsigned NumCStmts = sizeof(CStmts) / sizeof(CStmts[0]); 2720 for (unsigned I = 0; I != NumCStmts; ++I) 2721 Consumer.addKeywordResult(Context, CStmts[I]); 2722 2723 if (getLangOptions().CPlusPlus) { 2724 Consumer.addKeywordResult(Context, "catch"); 2725 Consumer.addKeywordResult(Context, "try"); 2726 } 2727 2728 if (S && S->getBreakParent()) 2729 Consumer.addKeywordResult(Context, "break"); 2730 2731 if (S && S->getContinueParent()) 2732 Consumer.addKeywordResult(Context, "continue"); 2733 2734 if (!getSwitchStack().empty()) { 2735 Consumer.addKeywordResult(Context, "case"); 2736 Consumer.addKeywordResult(Context, "default"); 2737 } 2738 } else { 2739 if (getLangOptions().CPlusPlus) { 2740 Consumer.addKeywordResult(Context, "namespace"); 2741 Consumer.addKeywordResult(Context, "template"); 2742 } 2743 2744 if (S && S->isClassScope()) { 2745 Consumer.addKeywordResult(Context, "explicit"); 2746 Consumer.addKeywordResult(Context, "friend"); 2747 Consumer.addKeywordResult(Context, "mutable"); 2748 Consumer.addKeywordResult(Context, "private"); 2749 Consumer.addKeywordResult(Context, "protected"); 2750 Consumer.addKeywordResult(Context, "public"); 2751 Consumer.addKeywordResult(Context, "virtual"); 2752 } 2753 } 2754 2755 if (getLangOptions().CPlusPlus) { 2756 Consumer.addKeywordResult(Context, "using"); 2757 2758 if (getLangOptions().CPlusPlus0x) 2759 Consumer.addKeywordResult(Context, "static_assert"); 2760 } 2761 } 2762 2763 // If we haven't found anything, we're done. 2764 if (Consumer.empty()) 2765 return DeclarationName(); 2766 2767 // Only allow a single, closest name in the result set (it's okay to 2768 // have overloads of that name, though). 2769 DeclarationName BestName; 2770 NamedDecl *BestIvarOrPropertyDecl = 0; 2771 bool FoundIvarOrPropertyDecl = false; 2772 2773 // Check all of the declaration results to find the best name so far. 2774 for (TypoCorrectionConsumer::iterator I = Consumer.begin(), 2775 IEnd = Consumer.end(); 2776 I != IEnd; ++I) { 2777 if (!BestName) 2778 BestName = (*I)->getDeclName(); 2779 else if (BestName != (*I)->getDeclName()) 2780 return DeclarationName(); 2781 2782 // \brief Keep track of either an Objective-C ivar or a property, but not 2783 // both. 2784 if (isa<ObjCIvarDecl>(*I) || isa<ObjCPropertyDecl>(*I)) { 2785 if (FoundIvarOrPropertyDecl) 2786 BestIvarOrPropertyDecl = 0; 2787 else { 2788 BestIvarOrPropertyDecl = *I; 2789 FoundIvarOrPropertyDecl = true; 2790 } 2791 } 2792 } 2793 2794 // Now check all of the keyword results to find the best name. 2795 switch (Consumer.keyword_size()) { 2796 case 0: 2797 // No keywords matched. 2798 break; 2799 2800 case 1: 2801 // If we already have a name 2802 if (!BestName) { 2803 // We did not have anything previously, 2804 BestName = *Consumer.keyword_begin(); 2805 } else if (BestName.getAsIdentifierInfo() == *Consumer.keyword_begin()) { 2806 // We have a declaration with the same name as a context-sensitive 2807 // keyword. The keyword takes precedence. 2808 BestIvarOrPropertyDecl = 0; 2809 FoundIvarOrPropertyDecl = false; 2810 Consumer.clear_decls(); 2811 } else { 2812 // Name collision; we will not correct typos. 2813 return DeclarationName(); 2814 } 2815 break; 2816 2817 default: 2818 // Name collision; we will not correct typos. 2819 return DeclarationName(); 2820 } 2821 2822 // BestName is the closest viable name to what the user 2823 // typed. However, to make sure that we don't pick something that's 2824 // way off, make sure that the user typed at least 3 characters for 2825 // each correction. 2826 unsigned ED = Consumer.getBestEditDistance(); 2827 if (ED == 0 || !BestName.getAsIdentifierInfo() || 2828 (BestName.getAsIdentifierInfo()->getName().size() / ED) < 3) 2829 return DeclarationName(); 2830 2831 // Perform name lookup again with the name we chose, and declare 2832 // success if we found something that was not ambiguous. 2833 Res.clear(); 2834 Res.setLookupName(BestName); 2835 2836 // If we found an ivar or property, add that result; no further 2837 // lookup is required. 2838 if (BestIvarOrPropertyDecl) 2839 Res.addDecl(BestIvarOrPropertyDecl); 2840 // If we're looking into the context of a member, perform qualified 2841 // name lookup on the best name. 2842 else if (!Consumer.keyword_empty()) { 2843 // The best match was a keyword. Return it. 2844 return BestName; 2845 } else if (MemberContext) 2846 LookupQualifiedName(Res, MemberContext); 2847 // Perform lookup as if we had just parsed the best name. 2848 else 2849 LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false, 2850 EnteringContext); 2851 2852 if (Res.isAmbiguous()) { 2853 Res.suppressDiagnostics(); 2854 return DeclarationName(); 2855 } 2856 2857 if (Res.getResultKind() != LookupResult::NotFound) 2858 return BestName; 2859 2860 return DeclarationName(); 2861} 2862