SemaLookup.cpp revision ba171099c6991c1bdc65631c7b89dc1ea746e786
1//===--------------------- SemaLookup.cpp - Name Lookup ------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements name lookup for C, C++, Objective-C, and 11// Objective-C++. 12// 13//===----------------------------------------------------------------------===// 14#include "Sema.h" 15#include "Lookup.h" 16#include "clang/AST/ASTContext.h" 17#include "clang/AST/CXXInheritance.h" 18#include "clang/AST/Decl.h" 19#include "clang/AST/DeclCXX.h" 20#include "clang/AST/DeclObjC.h" 21#include "clang/AST/DeclTemplate.h" 22#include "clang/AST/Expr.h" 23#include "clang/AST/ExprCXX.h" 24#include "clang/Parse/DeclSpec.h" 25#include "clang/Basic/Builtins.h" 26#include "clang/Basic/LangOptions.h" 27#include "llvm/ADT/STLExtras.h" 28#include "llvm/ADT/SmallPtrSet.h" 29#include "llvm/Support/ErrorHandling.h" 30#include <list> 31#include <set> 32#include <vector> 33#include <iterator> 34#include <utility> 35#include <algorithm> 36 37using namespace clang; 38 39namespace { 40 class UnqualUsingEntry { 41 const DeclContext *Nominated; 42 const DeclContext *CommonAncestor; 43 44 public: 45 UnqualUsingEntry(const DeclContext *Nominated, 46 const DeclContext *CommonAncestor) 47 : Nominated(Nominated), CommonAncestor(CommonAncestor) { 48 } 49 50 const DeclContext *getCommonAncestor() const { 51 return CommonAncestor; 52 } 53 54 const DeclContext *getNominatedNamespace() const { 55 return Nominated; 56 } 57 58 // Sort by the pointer value of the common ancestor. 59 struct Comparator { 60 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) { 61 return L.getCommonAncestor() < R.getCommonAncestor(); 62 } 63 64 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) { 65 return E.getCommonAncestor() < DC; 66 } 67 68 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) { 69 return DC < E.getCommonAncestor(); 70 } 71 }; 72 }; 73 74 /// A collection of using directives, as used by C++ unqualified 75 /// lookup. 76 class UnqualUsingDirectiveSet { 77 typedef llvm::SmallVector<UnqualUsingEntry, 8> ListTy; 78 79 ListTy list; 80 llvm::SmallPtrSet<DeclContext*, 8> visited; 81 82 public: 83 UnqualUsingDirectiveSet() {} 84 85 void visitScopeChain(Scope *S, Scope *InnermostFileScope) { 86 // C++ [namespace.udir]p1: 87 // During unqualified name lookup, the names appear as if they 88 // were declared in the nearest enclosing namespace which contains 89 // both the using-directive and the nominated namespace. 90 DeclContext *InnermostFileDC 91 = static_cast<DeclContext*>(InnermostFileScope->getEntity()); 92 assert(InnermostFileDC && InnermostFileDC->isFileContext()); 93 94 for (; S; S = S->getParent()) { 95 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) { 96 DeclContext *EffectiveDC = (Ctx->isFileContext() ? Ctx : InnermostFileDC); 97 visit(Ctx, EffectiveDC); 98 } else { 99 Scope::udir_iterator I = S->using_directives_begin(), 100 End = S->using_directives_end(); 101 102 for (; I != End; ++I) 103 visit(I->getAs<UsingDirectiveDecl>(), InnermostFileDC); 104 } 105 } 106 } 107 108 // Visits a context and collect all of its using directives 109 // recursively. Treats all using directives as if they were 110 // declared in the context. 111 // 112 // A given context is only every visited once, so it is important 113 // that contexts be visited from the inside out in order to get 114 // the effective DCs right. 115 void visit(DeclContext *DC, DeclContext *EffectiveDC) { 116 if (!visited.insert(DC)) 117 return; 118 119 addUsingDirectives(DC, EffectiveDC); 120 } 121 122 // Visits a using directive and collects all of its using 123 // directives recursively. Treats all using directives as if they 124 // were declared in the effective DC. 125 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 126 DeclContext *NS = UD->getNominatedNamespace(); 127 if (!visited.insert(NS)) 128 return; 129 130 addUsingDirective(UD, EffectiveDC); 131 addUsingDirectives(NS, EffectiveDC); 132 } 133 134 // Adds all the using directives in a context (and those nominated 135 // by its using directives, transitively) as if they appeared in 136 // the given effective context. 137 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) { 138 llvm::SmallVector<DeclContext*,4> queue; 139 while (true) { 140 DeclContext::udir_iterator I, End; 141 for (llvm::tie(I, End) = DC->getUsingDirectives(); I != End; ++I) { 142 UsingDirectiveDecl *UD = *I; 143 DeclContext *NS = UD->getNominatedNamespace(); 144 if (visited.insert(NS)) { 145 addUsingDirective(UD, EffectiveDC); 146 queue.push_back(NS); 147 } 148 } 149 150 if (queue.empty()) 151 return; 152 153 DC = queue.back(); 154 queue.pop_back(); 155 } 156 } 157 158 // Add a using directive as if it had been declared in the given 159 // context. This helps implement C++ [namespace.udir]p3: 160 // The using-directive is transitive: if a scope contains a 161 // using-directive that nominates a second namespace that itself 162 // contains using-directives, the effect is as if the 163 // using-directives from the second namespace also appeared in 164 // the first. 165 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 166 // Find the common ancestor between the effective context and 167 // the nominated namespace. 168 DeclContext *Common = UD->getNominatedNamespace(); 169 while (!Common->Encloses(EffectiveDC)) 170 Common = Common->getParent(); 171 Common = Common->getPrimaryContext(); 172 173 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common)); 174 } 175 176 void done() { 177 std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator()); 178 } 179 180 typedef ListTy::iterator iterator; 181 typedef ListTy::const_iterator const_iterator; 182 183 iterator begin() { return list.begin(); } 184 iterator end() { return list.end(); } 185 const_iterator begin() const { return list.begin(); } 186 const_iterator end() const { return list.end(); } 187 188 std::pair<const_iterator,const_iterator> 189 getNamespacesFor(DeclContext *DC) const { 190 return std::equal_range(begin(), end(), DC->getPrimaryContext(), 191 UnqualUsingEntry::Comparator()); 192 } 193 }; 194} 195 196static bool IsAcceptableIDNS(NamedDecl *D, unsigned IDNS) { 197 return D->isInIdentifierNamespace(IDNS); 198} 199 200static bool IsAcceptableOperatorName(NamedDecl *D, unsigned IDNS) { 201 return D->isInIdentifierNamespace(IDNS) && 202 !D->getDeclContext()->isRecord(); 203} 204 205static bool IsAcceptableNestedNameSpecifierName(NamedDecl *D, unsigned IDNS) { 206 // This lookup ignores everything that isn't a type. 207 208 // This is a fast check for the far most common case. 209 if (D->isInIdentifierNamespace(Decl::IDNS_Tag)) 210 return true; 211 212 if (isa<UsingShadowDecl>(D)) 213 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 214 215 return isa<TypeDecl>(D); 216} 217 218static bool IsAcceptableNamespaceName(NamedDecl *D, unsigned IDNS) { 219 // We don't need to look through using decls here because 220 // using decls aren't allowed to name namespaces. 221 222 return isa<NamespaceDecl>(D) || isa<NamespaceAliasDecl>(D); 223} 224 225/// Gets the default result filter for the given lookup. 226static inline 227LookupResult::ResultFilter getResultFilter(Sema::LookupNameKind NameKind) { 228 switch (NameKind) { 229 case Sema::LookupOrdinaryName: 230 case Sema::LookupTagName: 231 case Sema::LookupMemberName: 232 case Sema::LookupRedeclarationWithLinkage: // FIXME: check linkage, scoping 233 case Sema::LookupUsingDeclName: 234 case Sema::LookupObjCProtocolName: 235 case Sema::LookupObjCImplementationName: 236 return &IsAcceptableIDNS; 237 238 case Sema::LookupOperatorName: 239 return &IsAcceptableOperatorName; 240 241 case Sema::LookupNestedNameSpecifierName: 242 return &IsAcceptableNestedNameSpecifierName; 243 244 case Sema::LookupNamespaceName: 245 return &IsAcceptableNamespaceName; 246 } 247 248 llvm_unreachable("unkknown lookup kind"); 249 return 0; 250} 251 252// Retrieve the set of identifier namespaces that correspond to a 253// specific kind of name lookup. 254static inline unsigned getIDNS(Sema::LookupNameKind NameKind, 255 bool CPlusPlus, 256 bool Redeclaration) { 257 unsigned IDNS = 0; 258 switch (NameKind) { 259 case Sema::LookupOrdinaryName: 260 case Sema::LookupOperatorName: 261 case Sema::LookupRedeclarationWithLinkage: 262 IDNS = Decl::IDNS_Ordinary; 263 if (CPlusPlus) { 264 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member; 265 if (Redeclaration) IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend; 266 } 267 break; 268 269 case Sema::LookupTagName: 270 IDNS = Decl::IDNS_Tag; 271 if (CPlusPlus && Redeclaration) 272 IDNS |= Decl::IDNS_TagFriend; 273 break; 274 275 case Sema::LookupMemberName: 276 IDNS = Decl::IDNS_Member; 277 if (CPlusPlus) 278 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary; 279 break; 280 281 case Sema::LookupNestedNameSpecifierName: 282 case Sema::LookupNamespaceName: 283 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member; 284 break; 285 286 case Sema::LookupUsingDeclName: 287 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag 288 | Decl::IDNS_Member | Decl::IDNS_Using; 289 break; 290 291 case Sema::LookupObjCProtocolName: 292 IDNS = Decl::IDNS_ObjCProtocol; 293 break; 294 295 case Sema::LookupObjCImplementationName: 296 IDNS = Decl::IDNS_ObjCImplementation; 297 break; 298 } 299 return IDNS; 300} 301 302void LookupResult::configure() { 303 IDNS = getIDNS(LookupKind, 304 SemaRef.getLangOptions().CPlusPlus, 305 isForRedeclaration()); 306 IsAcceptableFn = getResultFilter(LookupKind); 307} 308 309// Necessary because CXXBasePaths is not complete in Sema.h 310void LookupResult::deletePaths(CXXBasePaths *Paths) { 311 delete Paths; 312} 313 314/// Resolves the result kind of this lookup. 315void LookupResult::resolveKind() { 316 unsigned N = Decls.size(); 317 318 // Fast case: no possible ambiguity. 319 if (N == 0) { 320 assert(ResultKind == NotFound); 321 return; 322 } 323 324 // If there's a single decl, we need to examine it to decide what 325 // kind of lookup this is. 326 if (N == 1) { 327 if (isa<FunctionTemplateDecl>(Decls[0])) 328 ResultKind = FoundOverloaded; 329 else if (isa<UnresolvedUsingValueDecl>(Decls[0])) 330 ResultKind = FoundUnresolvedValue; 331 return; 332 } 333 334 // Don't do any extra resolution if we've already resolved as ambiguous. 335 if (ResultKind == Ambiguous) return; 336 337 llvm::SmallPtrSet<NamedDecl*, 16> Unique; 338 339 bool Ambiguous = false; 340 bool HasTag = false, HasFunction = false, HasNonFunction = false; 341 bool HasFunctionTemplate = false, HasUnresolved = false; 342 343 unsigned UniqueTagIndex = 0; 344 345 unsigned I = 0; 346 while (I < N) { 347 NamedDecl *D = Decls[I]->getUnderlyingDecl(); 348 D = cast<NamedDecl>(D->getCanonicalDecl()); 349 350 if (!Unique.insert(D)) { 351 // If it's not unique, pull something off the back (and 352 // continue at this index). 353 Decls[I] = Decls[--N]; 354 } else { 355 // Otherwise, do some decl type analysis and then continue. 356 357 if (isa<UnresolvedUsingValueDecl>(D)) { 358 HasUnresolved = true; 359 } else if (isa<TagDecl>(D)) { 360 if (HasTag) 361 Ambiguous = true; 362 UniqueTagIndex = I; 363 HasTag = true; 364 } else if (isa<FunctionTemplateDecl>(D)) { 365 HasFunction = true; 366 HasFunctionTemplate = true; 367 } else if (isa<FunctionDecl>(D)) { 368 HasFunction = true; 369 } else { 370 if (HasNonFunction) 371 Ambiguous = true; 372 HasNonFunction = true; 373 } 374 I++; 375 } 376 } 377 378 // C++ [basic.scope.hiding]p2: 379 // A class name or enumeration name can be hidden by the name of 380 // an object, function, or enumerator declared in the same 381 // scope. If a class or enumeration name and an object, function, 382 // or enumerator are declared in the same scope (in any order) 383 // with the same name, the class or enumeration name is hidden 384 // wherever the object, function, or enumerator name is visible. 385 // But it's still an error if there are distinct tag types found, 386 // even if they're not visible. (ref?) 387 if (HideTags && HasTag && !Ambiguous && 388 (HasFunction || HasNonFunction || HasUnresolved)) 389 Decls[UniqueTagIndex] = Decls[--N]; 390 391 Decls.set_size(N); 392 393 if (HasNonFunction && (HasFunction || HasUnresolved)) 394 Ambiguous = true; 395 396 if (Ambiguous) 397 setAmbiguous(LookupResult::AmbiguousReference); 398 else if (HasUnresolved) 399 ResultKind = LookupResult::FoundUnresolvedValue; 400 else if (N > 1 || HasFunctionTemplate) 401 ResultKind = LookupResult::FoundOverloaded; 402 else 403 ResultKind = LookupResult::Found; 404} 405 406void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) { 407 CXXBasePaths::paths_iterator I, E; 408 DeclContext::lookup_iterator DI, DE; 409 for (I = P.begin(), E = P.end(); I != E; ++I) 410 for (llvm::tie(DI,DE) = I->Decls; DI != DE; ++DI) 411 addDecl(*DI); 412} 413 414void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) { 415 Paths = new CXXBasePaths; 416 Paths->swap(P); 417 addDeclsFromBasePaths(*Paths); 418 resolveKind(); 419 setAmbiguous(AmbiguousBaseSubobjects); 420} 421 422void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) { 423 Paths = new CXXBasePaths; 424 Paths->swap(P); 425 addDeclsFromBasePaths(*Paths); 426 resolveKind(); 427 setAmbiguous(AmbiguousBaseSubobjectTypes); 428} 429 430void LookupResult::print(llvm::raw_ostream &Out) { 431 Out << Decls.size() << " result(s)"; 432 if (isAmbiguous()) Out << ", ambiguous"; 433 if (Paths) Out << ", base paths present"; 434 435 for (iterator I = begin(), E = end(); I != E; ++I) { 436 Out << "\n"; 437 (*I)->print(Out, 2); 438 } 439} 440 441// Adds all qualifying matches for a name within a decl context to the 442// given lookup result. Returns true if any matches were found. 443static bool LookupDirect(LookupResult &R, const DeclContext *DC) { 444 bool Found = false; 445 446 DeclContext::lookup_const_iterator I, E; 447 for (llvm::tie(I, E) = DC->lookup(R.getLookupName()); I != E; ++I) { 448 if (R.isAcceptableDecl(*I)) { 449 R.addDecl(*I); 450 Found = true; 451 } 452 } 453 454 if (R.getLookupName().getNameKind() 455 == DeclarationName::CXXConversionFunctionName && 456 !R.getLookupName().getCXXNameType()->isDependentType() && 457 isa<CXXRecordDecl>(DC)) { 458 // C++ [temp.mem]p6: 459 // A specialization of a conversion function template is not found by 460 // name lookup. Instead, any conversion function templates visible in the 461 // context of the use are considered. [...] 462 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC); 463 464 const UnresolvedSet *Unresolved = Record->getConversionFunctions(); 465 for (UnresolvedSet::iterator U = Unresolved->begin(), 466 UEnd = Unresolved->end(); 467 U != UEnd; ++U) { 468 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U); 469 if (!ConvTemplate) 470 continue; 471 472 // When we're performing lookup for the purposes of redeclaration, just 473 // add the conversion function template. When we deduce template 474 // arguments for specializations, we'll end up unifying the return 475 // type of the new declaration with the type of the function template. 476 if (R.isForRedeclaration()) { 477 R.addDecl(ConvTemplate); 478 Found = true; 479 continue; 480 } 481 482 // C++ [temp.mem]p6: 483 // [...] For each such operator, if argument deduction succeeds 484 // (14.9.2.3), the resulting specialization is used as if found by 485 // name lookup. 486 // 487 // When referencing a conversion function for any purpose other than 488 // a redeclaration (such that we'll be building an expression with the 489 // result), perform template argument deduction and place the 490 // specialization into the result set. We do this to avoid forcing all 491 // callers to perform special deduction for conversion functions. 492 Sema::TemplateDeductionInfo Info(R.getSema().Context); 493 FunctionDecl *Specialization = 0; 494 495 const FunctionProtoType *ConvProto 496 = ConvTemplate->getTemplatedDecl()->getType() 497 ->getAs<FunctionProtoType>(); 498 assert(ConvProto && "Nonsensical conversion function template type"); 499 500 // Compute the type of the function that we would expect the conversion 501 // function to have, if it were to match the name given. 502 // FIXME: Calling convention! 503 QualType ExpectedType 504 = R.getSema().Context.getFunctionType( 505 R.getLookupName().getCXXNameType(), 506 0, 0, ConvProto->isVariadic(), 507 ConvProto->getTypeQuals(), 508 false, false, 0, 0, 509 ConvProto->getNoReturnAttr()); 510 511 // Perform template argument deduction against the type that we would 512 // expect the function to have. 513 if (R.getSema().DeduceTemplateArguments(ConvTemplate, 0, ExpectedType, 514 Specialization, Info) 515 == Sema::TDK_Success) { 516 R.addDecl(Specialization); 517 Found = true; 518 } 519 } 520 } 521 522 return Found; 523} 524 525// Performs C++ unqualified lookup into the given file context. 526static bool 527CppNamespaceLookup(LookupResult &R, ASTContext &Context, DeclContext *NS, 528 UnqualUsingDirectiveSet &UDirs) { 529 530 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!"); 531 532 // Perform direct name lookup into the LookupCtx. 533 bool Found = LookupDirect(R, NS); 534 535 // Perform direct name lookup into the namespaces nominated by the 536 // using directives whose common ancestor is this namespace. 537 UnqualUsingDirectiveSet::const_iterator UI, UEnd; 538 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(NS); 539 540 for (; UI != UEnd; ++UI) 541 if (LookupDirect(R, UI->getNominatedNamespace())) 542 Found = true; 543 544 R.resolveKind(); 545 546 return Found; 547} 548 549static bool isNamespaceOrTranslationUnitScope(Scope *S) { 550 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) 551 return Ctx->isFileContext(); 552 return false; 553} 554 555// Find the next outer declaration context corresponding to this scope. 556static DeclContext *findOuterContext(Scope *S) { 557 for (S = S->getParent(); S; S = S->getParent()) 558 if (S->getEntity()) 559 return static_cast<DeclContext *>(S->getEntity())->getPrimaryContext(); 560 561 return 0; 562} 563 564bool Sema::CppLookupName(LookupResult &R, Scope *S) { 565 assert(getLangOptions().CPlusPlus && "Can perform only C++ lookup"); 566 567 DeclarationName Name = R.getLookupName(); 568 569 Scope *Initial = S; 570 IdentifierResolver::iterator 571 I = IdResolver.begin(Name), 572 IEnd = IdResolver.end(); 573 574 // First we lookup local scope. 575 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir] 576 // ...During unqualified name lookup (3.4.1), the names appear as if 577 // they were declared in the nearest enclosing namespace which contains 578 // both the using-directive and the nominated namespace. 579 // [Note: in this context, "contains" means "contains directly or 580 // indirectly". 581 // 582 // For example: 583 // namespace A { int i; } 584 // void foo() { 585 // int i; 586 // { 587 // using namespace A; 588 // ++i; // finds local 'i', A::i appears at global scope 589 // } 590 // } 591 // 592 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) { 593 // Check whether the IdResolver has anything in this scope. 594 bool Found = false; 595 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) { 596 if (R.isAcceptableDecl(*I)) { 597 Found = true; 598 R.addDecl(*I); 599 } 600 } 601 if (Found) { 602 R.resolveKind(); 603 return true; 604 } 605 606 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) { 607 DeclContext *OuterCtx = findOuterContext(S); 608 for (; Ctx && Ctx->getPrimaryContext() != OuterCtx; 609 Ctx = Ctx->getLookupParent()) { 610 // We do not directly look into function or method contexts 611 // (since all local variables are found via the identifier 612 // changes) or in transparent contexts (since those entities 613 // will be found in the nearest enclosing non-transparent 614 // context). 615 if (Ctx->isFunctionOrMethod() || Ctx->isTransparentContext()) 616 continue; 617 618 // Perform qualified name lookup into this context. 619 // FIXME: In some cases, we know that every name that could be found by 620 // this qualified name lookup will also be on the identifier chain. For 621 // example, inside a class without any base classes, we never need to 622 // perform qualified lookup because all of the members are on top of the 623 // identifier chain. 624 if (LookupQualifiedName(R, Ctx)) 625 return true; 626 } 627 } 628 } 629 630 // Stop if we ran out of scopes. 631 // FIXME: This really, really shouldn't be happening. 632 if (!S) return false; 633 634 // Collect UsingDirectiveDecls in all scopes, and recursively all 635 // nominated namespaces by those using-directives. 636 // 637 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we 638 // don't build it for each lookup! 639 640 UnqualUsingDirectiveSet UDirs; 641 UDirs.visitScopeChain(Initial, S); 642 UDirs.done(); 643 644 // Lookup namespace scope, and global scope. 645 // Unqualified name lookup in C++ requires looking into scopes 646 // that aren't strictly lexical, and therefore we walk through the 647 // context as well as walking through the scopes. 648 649 for (; S; S = S->getParent()) { 650 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity()); 651 if (Ctx->isTransparentContext()) 652 continue; 653 654 assert(Ctx && Ctx->isFileContext() && 655 "We should have been looking only at file context here already."); 656 657 // Check whether the IdResolver has anything in this scope. 658 bool Found = false; 659 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) { 660 if (R.isAcceptableDecl(*I)) { 661 // We found something. Look for anything else in our scope 662 // with this same name and in an acceptable identifier 663 // namespace, so that we can construct an overload set if we 664 // need to. 665 Found = true; 666 R.addDecl(*I); 667 } 668 } 669 670 // Look into context considering using-directives. 671 if (CppNamespaceLookup(R, Context, Ctx, UDirs)) 672 Found = true; 673 674 if (Found) { 675 R.resolveKind(); 676 return true; 677 } 678 679 if (R.isForRedeclaration() && !Ctx->isTransparentContext()) 680 return false; 681 } 682 683 return !R.empty(); 684} 685 686/// @brief Perform unqualified name lookup starting from a given 687/// scope. 688/// 689/// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is 690/// used to find names within the current scope. For example, 'x' in 691/// @code 692/// int x; 693/// int f() { 694/// return x; // unqualified name look finds 'x' in the global scope 695/// } 696/// @endcode 697/// 698/// Different lookup criteria can find different names. For example, a 699/// particular scope can have both a struct and a function of the same 700/// name, and each can be found by certain lookup criteria. For more 701/// information about lookup criteria, see the documentation for the 702/// class LookupCriteria. 703/// 704/// @param S The scope from which unqualified name lookup will 705/// begin. If the lookup criteria permits, name lookup may also search 706/// in the parent scopes. 707/// 708/// @param Name The name of the entity that we are searching for. 709/// 710/// @param Loc If provided, the source location where we're performing 711/// name lookup. At present, this is only used to produce diagnostics when 712/// C library functions (like "malloc") are implicitly declared. 713/// 714/// @returns The result of name lookup, which includes zero or more 715/// declarations and possibly additional information used to diagnose 716/// ambiguities. 717bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) { 718 DeclarationName Name = R.getLookupName(); 719 if (!Name) return false; 720 721 LookupNameKind NameKind = R.getLookupKind(); 722 723 if (!getLangOptions().CPlusPlus) { 724 // Unqualified name lookup in C/Objective-C is purely lexical, so 725 // search in the declarations attached to the name. 726 727 if (NameKind == Sema::LookupRedeclarationWithLinkage) { 728 // Find the nearest non-transparent declaration scope. 729 while (!(S->getFlags() & Scope::DeclScope) || 730 (S->getEntity() && 731 static_cast<DeclContext *>(S->getEntity()) 732 ->isTransparentContext())) 733 S = S->getParent(); 734 } 735 736 unsigned IDNS = R.getIdentifierNamespace(); 737 738 // Scan up the scope chain looking for a decl that matches this 739 // identifier that is in the appropriate namespace. This search 740 // should not take long, as shadowing of names is uncommon, and 741 // deep shadowing is extremely uncommon. 742 bool LeftStartingScope = false; 743 744 for (IdentifierResolver::iterator I = IdResolver.begin(Name), 745 IEnd = IdResolver.end(); 746 I != IEnd; ++I) 747 if ((*I)->isInIdentifierNamespace(IDNS)) { 748 if (NameKind == LookupRedeclarationWithLinkage) { 749 // Determine whether this (or a previous) declaration is 750 // out-of-scope. 751 if (!LeftStartingScope && !S->isDeclScope(DeclPtrTy::make(*I))) 752 LeftStartingScope = true; 753 754 // If we found something outside of our starting scope that 755 // does not have linkage, skip it. 756 if (LeftStartingScope && !((*I)->hasLinkage())) 757 continue; 758 } 759 760 R.addDecl(*I); 761 762 if ((*I)->getAttr<OverloadableAttr>()) { 763 // If this declaration has the "overloadable" attribute, we 764 // might have a set of overloaded functions. 765 766 // Figure out what scope the identifier is in. 767 while (!(S->getFlags() & Scope::DeclScope) || 768 !S->isDeclScope(DeclPtrTy::make(*I))) 769 S = S->getParent(); 770 771 // Find the last declaration in this scope (with the same 772 // name, naturally). 773 IdentifierResolver::iterator LastI = I; 774 for (++LastI; LastI != IEnd; ++LastI) { 775 if (!S->isDeclScope(DeclPtrTy::make(*LastI))) 776 break; 777 R.addDecl(*LastI); 778 } 779 } 780 781 R.resolveKind(); 782 783 return true; 784 } 785 } else { 786 // Perform C++ unqualified name lookup. 787 if (CppLookupName(R, S)) 788 return true; 789 } 790 791 // If we didn't find a use of this identifier, and if the identifier 792 // corresponds to a compiler builtin, create the decl object for the builtin 793 // now, injecting it into translation unit scope, and return it. 794 if (NameKind == LookupOrdinaryName || 795 NameKind == LookupRedeclarationWithLinkage) { 796 IdentifierInfo *II = Name.getAsIdentifierInfo(); 797 if (II && AllowBuiltinCreation) { 798 // If this is a builtin on this (or all) targets, create the decl. 799 if (unsigned BuiltinID = II->getBuiltinID()) { 800 // In C++, we don't have any predefined library functions like 801 // 'malloc'. Instead, we'll just error. 802 if (getLangOptions().CPlusPlus && 803 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 804 return false; 805 806 NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 807 S, R.isForRedeclaration(), 808 R.getNameLoc()); 809 if (D) R.addDecl(D); 810 return (D != NULL); 811 } 812 } 813 } 814 return false; 815} 816 817/// @brief Perform qualified name lookup in the namespaces nominated by 818/// using directives by the given context. 819/// 820/// C++98 [namespace.qual]p2: 821/// Given X::m (where X is a user-declared namespace), or given ::m 822/// (where X is the global namespace), let S be the set of all 823/// declarations of m in X and in the transitive closure of all 824/// namespaces nominated by using-directives in X and its used 825/// namespaces, except that using-directives are ignored in any 826/// namespace, including X, directly containing one or more 827/// declarations of m. No namespace is searched more than once in 828/// the lookup of a name. If S is the empty set, the program is 829/// ill-formed. Otherwise, if S has exactly one member, or if the 830/// context of the reference is a using-declaration 831/// (namespace.udecl), S is the required set of declarations of 832/// m. Otherwise if the use of m is not one that allows a unique 833/// declaration to be chosen from S, the program is ill-formed. 834/// C++98 [namespace.qual]p5: 835/// During the lookup of a qualified namespace member name, if the 836/// lookup finds more than one declaration of the member, and if one 837/// declaration introduces a class name or enumeration name and the 838/// other declarations either introduce the same object, the same 839/// enumerator or a set of functions, the non-type name hides the 840/// class or enumeration name if and only if the declarations are 841/// from the same namespace; otherwise (the declarations are from 842/// different namespaces), the program is ill-formed. 843static bool LookupQualifiedNameInUsingDirectives(LookupResult &R, 844 DeclContext *StartDC) { 845 assert(StartDC->isFileContext() && "start context is not a file context"); 846 847 DeclContext::udir_iterator I = StartDC->using_directives_begin(); 848 DeclContext::udir_iterator E = StartDC->using_directives_end(); 849 850 if (I == E) return false; 851 852 // We have at least added all these contexts to the queue. 853 llvm::DenseSet<DeclContext*> Visited; 854 Visited.insert(StartDC); 855 856 // We have not yet looked into these namespaces, much less added 857 // their "using-children" to the queue. 858 llvm::SmallVector<NamespaceDecl*, 8> Queue; 859 860 // We have already looked into the initial namespace; seed the queue 861 // with its using-children. 862 for (; I != E; ++I) { 863 NamespaceDecl *ND = (*I)->getNominatedNamespace()->getOriginalNamespace(); 864 if (Visited.insert(ND).second) 865 Queue.push_back(ND); 866 } 867 868 // The easiest way to implement the restriction in [namespace.qual]p5 869 // is to check whether any of the individual results found a tag 870 // and, if so, to declare an ambiguity if the final result is not 871 // a tag. 872 bool FoundTag = false; 873 bool FoundNonTag = false; 874 875 LookupResult LocalR(LookupResult::Temporary, R); 876 877 bool Found = false; 878 while (!Queue.empty()) { 879 NamespaceDecl *ND = Queue.back(); 880 Queue.pop_back(); 881 882 // We go through some convolutions here to avoid copying results 883 // between LookupResults. 884 bool UseLocal = !R.empty(); 885 LookupResult &DirectR = UseLocal ? LocalR : R; 886 bool FoundDirect = LookupDirect(DirectR, ND); 887 888 if (FoundDirect) { 889 // First do any local hiding. 890 DirectR.resolveKind(); 891 892 // If the local result is a tag, remember that. 893 if (DirectR.isSingleTagDecl()) 894 FoundTag = true; 895 else 896 FoundNonTag = true; 897 898 // Append the local results to the total results if necessary. 899 if (UseLocal) { 900 R.addAllDecls(LocalR); 901 LocalR.clear(); 902 } 903 } 904 905 // If we find names in this namespace, ignore its using directives. 906 if (FoundDirect) { 907 Found = true; 908 continue; 909 } 910 911 for (llvm::tie(I,E) = ND->getUsingDirectives(); I != E; ++I) { 912 NamespaceDecl *Nom = (*I)->getNominatedNamespace(); 913 if (Visited.insert(Nom).second) 914 Queue.push_back(Nom); 915 } 916 } 917 918 if (Found) { 919 if (FoundTag && FoundNonTag) 920 R.setAmbiguousQualifiedTagHiding(); 921 else 922 R.resolveKind(); 923 } 924 925 return Found; 926} 927 928/// @brief Perform qualified name lookup into a given context. 929/// 930/// Qualified name lookup (C++ [basic.lookup.qual]) is used to find 931/// names when the context of those names is explicit specified, e.g., 932/// "std::vector" or "x->member". 933/// 934/// Different lookup criteria can find different names. For example, a 935/// particular scope can have both a struct and a function of the same 936/// name, and each can be found by certain lookup criteria. For more 937/// information about lookup criteria, see the documentation for the 938/// class LookupCriteria. 939/// 940/// @param LookupCtx The context in which qualified name lookup will 941/// search. If the lookup criteria permits, name lookup may also search 942/// in the parent contexts or (for C++ classes) base classes. 943/// 944/// @param Name The name of the entity that we are searching for. 945/// 946/// @param Criteria The criteria that this routine will use to 947/// determine which names are visible and which names will be 948/// found. Note that name lookup will find a name that is visible by 949/// the given criteria, but the entity itself may not be semantically 950/// correct or even the kind of entity expected based on the 951/// lookup. For example, searching for a nested-name-specifier name 952/// might result in an EnumDecl, which is visible but is not permitted 953/// as a nested-name-specifier in C++03. 954/// 955/// @returns The result of name lookup, which includes zero or more 956/// declarations and possibly additional information used to diagnose 957/// ambiguities. 958bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx) { 959 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context"); 960 961 if (!R.getLookupName()) 962 return false; 963 964 // Make sure that the declaration context is complete. 965 assert((!isa<TagDecl>(LookupCtx) || 966 LookupCtx->isDependentContext() || 967 cast<TagDecl>(LookupCtx)->isDefinition() || 968 Context.getTypeDeclType(cast<TagDecl>(LookupCtx))->getAs<TagType>() 969 ->isBeingDefined()) && 970 "Declaration context must already be complete!"); 971 972 // Perform qualified name lookup into the LookupCtx. 973 if (LookupDirect(R, LookupCtx)) { 974 R.resolveKind(); 975 return true; 976 } 977 978 // Don't descend into implied contexts for redeclarations. 979 // C++98 [namespace.qual]p6: 980 // In a declaration for a namespace member in which the 981 // declarator-id is a qualified-id, given that the qualified-id 982 // for the namespace member has the form 983 // nested-name-specifier unqualified-id 984 // the unqualified-id shall name a member of the namespace 985 // designated by the nested-name-specifier. 986 // See also [class.mfct]p5 and [class.static.data]p2. 987 if (R.isForRedeclaration()) 988 return false; 989 990 // If this is a namespace, look it up in the implied namespaces. 991 if (LookupCtx->isFileContext()) 992 return LookupQualifiedNameInUsingDirectives(R, LookupCtx); 993 994 // If this isn't a C++ class, we aren't allowed to look into base 995 // classes, we're done. 996 if (!isa<CXXRecordDecl>(LookupCtx)) 997 return false; 998 999 // Perform lookup into our base classes. 1000 CXXRecordDecl *LookupRec = cast<CXXRecordDecl>(LookupCtx); 1001 CXXBasePaths Paths; 1002 Paths.setOrigin(LookupRec); 1003 1004 // Look for this member in our base classes 1005 CXXRecordDecl::BaseMatchesCallback *BaseCallback = 0; 1006 switch (R.getLookupKind()) { 1007 case LookupOrdinaryName: 1008 case LookupMemberName: 1009 case LookupRedeclarationWithLinkage: 1010 BaseCallback = &CXXRecordDecl::FindOrdinaryMember; 1011 break; 1012 1013 case LookupTagName: 1014 BaseCallback = &CXXRecordDecl::FindTagMember; 1015 break; 1016 1017 case LookupUsingDeclName: 1018 // This lookup is for redeclarations only. 1019 1020 case LookupOperatorName: 1021 case LookupNamespaceName: 1022 case LookupObjCProtocolName: 1023 case LookupObjCImplementationName: 1024 // These lookups will never find a member in a C++ class (or base class). 1025 return false; 1026 1027 case LookupNestedNameSpecifierName: 1028 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember; 1029 break; 1030 } 1031 1032 if (!LookupRec->lookupInBases(BaseCallback, 1033 R.getLookupName().getAsOpaquePtr(), Paths)) 1034 return false; 1035 1036 // C++ [class.member.lookup]p2: 1037 // [...] If the resulting set of declarations are not all from 1038 // sub-objects of the same type, or the set has a nonstatic member 1039 // and includes members from distinct sub-objects, there is an 1040 // ambiguity and the program is ill-formed. Otherwise that set is 1041 // the result of the lookup. 1042 // FIXME: support using declarations! 1043 QualType SubobjectType; 1044 int SubobjectNumber = 0; 1045 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); 1046 Path != PathEnd; ++Path) { 1047 const CXXBasePathElement &PathElement = Path->back(); 1048 1049 // Determine whether we're looking at a distinct sub-object or not. 1050 if (SubobjectType.isNull()) { 1051 // This is the first subobject we've looked at. Record its type. 1052 SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); 1053 SubobjectNumber = PathElement.SubobjectNumber; 1054 } else if (SubobjectType 1055 != Context.getCanonicalType(PathElement.Base->getType())) { 1056 // We found members of the given name in two subobjects of 1057 // different types. This lookup is ambiguous. 1058 R.setAmbiguousBaseSubobjectTypes(Paths); 1059 return true; 1060 } else if (SubobjectNumber != PathElement.SubobjectNumber) { 1061 // We have a different subobject of the same type. 1062 1063 // C++ [class.member.lookup]p5: 1064 // A static member, a nested type or an enumerator defined in 1065 // a base class T can unambiguously be found even if an object 1066 // has more than one base class subobject of type T. 1067 Decl *FirstDecl = *Path->Decls.first; 1068 if (isa<VarDecl>(FirstDecl) || 1069 isa<TypeDecl>(FirstDecl) || 1070 isa<EnumConstantDecl>(FirstDecl)) 1071 continue; 1072 1073 if (isa<CXXMethodDecl>(FirstDecl)) { 1074 // Determine whether all of the methods are static. 1075 bool AllMethodsAreStatic = true; 1076 for (DeclContext::lookup_iterator Func = Path->Decls.first; 1077 Func != Path->Decls.second; ++Func) { 1078 if (!isa<CXXMethodDecl>(*Func)) { 1079 assert(isa<TagDecl>(*Func) && "Non-function must be a tag decl"); 1080 break; 1081 } 1082 1083 if (!cast<CXXMethodDecl>(*Func)->isStatic()) { 1084 AllMethodsAreStatic = false; 1085 break; 1086 } 1087 } 1088 1089 if (AllMethodsAreStatic) 1090 continue; 1091 } 1092 1093 // We have found a nonstatic member name in multiple, distinct 1094 // subobjects. Name lookup is ambiguous. 1095 R.setAmbiguousBaseSubobjects(Paths); 1096 return true; 1097 } 1098 } 1099 1100 // Lookup in a base class succeeded; return these results. 1101 1102 DeclContext::lookup_iterator I, E; 1103 for (llvm::tie(I,E) = Paths.front().Decls; I != E; ++I) 1104 R.addDecl(*I); 1105 R.resolveKind(); 1106 return true; 1107} 1108 1109/// @brief Performs name lookup for a name that was parsed in the 1110/// source code, and may contain a C++ scope specifier. 1111/// 1112/// This routine is a convenience routine meant to be called from 1113/// contexts that receive a name and an optional C++ scope specifier 1114/// (e.g., "N::M::x"). It will then perform either qualified or 1115/// unqualified name lookup (with LookupQualifiedName or LookupName, 1116/// respectively) on the given name and return those results. 1117/// 1118/// @param S The scope from which unqualified name lookup will 1119/// begin. 1120/// 1121/// @param SS An optional C++ scope-specifier, e.g., "::N::M". 1122/// 1123/// @param Name The name of the entity that name lookup will 1124/// search for. 1125/// 1126/// @param Loc If provided, the source location where we're performing 1127/// name lookup. At present, this is only used to produce diagnostics when 1128/// C library functions (like "malloc") are implicitly declared. 1129/// 1130/// @param EnteringContext Indicates whether we are going to enter the 1131/// context of the scope-specifier SS (if present). 1132/// 1133/// @returns True if any decls were found (but possibly ambiguous) 1134bool Sema::LookupParsedName(LookupResult &R, Scope *S, const CXXScopeSpec *SS, 1135 bool AllowBuiltinCreation, bool EnteringContext) { 1136 if (SS && SS->isInvalid()) { 1137 // When the scope specifier is invalid, don't even look for 1138 // anything. 1139 return false; 1140 } 1141 1142 if (SS && SS->isSet()) { 1143 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { 1144 // We have resolved the scope specifier to a particular declaration 1145 // contex, and will perform name lookup in that context. 1146 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS)) 1147 return false; 1148 1149 R.setContextRange(SS->getRange()); 1150 1151 return LookupQualifiedName(R, DC); 1152 } 1153 1154 // We could not resolve the scope specified to a specific declaration 1155 // context, which means that SS refers to an unknown specialization. 1156 // Name lookup can't find anything in this case. 1157 return false; 1158 } 1159 1160 // Perform unqualified name lookup starting in the given scope. 1161 return LookupName(R, S, AllowBuiltinCreation); 1162} 1163 1164 1165/// @brief Produce a diagnostic describing the ambiguity that resulted 1166/// from name lookup. 1167/// 1168/// @param Result The ambiguous name lookup result. 1169/// 1170/// @param Name The name of the entity that name lookup was 1171/// searching for. 1172/// 1173/// @param NameLoc The location of the name within the source code. 1174/// 1175/// @param LookupRange A source range that provides more 1176/// source-location information concerning the lookup itself. For 1177/// example, this range might highlight a nested-name-specifier that 1178/// precedes the name. 1179/// 1180/// @returns true 1181bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result) { 1182 assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); 1183 1184 DeclarationName Name = Result.getLookupName(); 1185 SourceLocation NameLoc = Result.getNameLoc(); 1186 SourceRange LookupRange = Result.getContextRange(); 1187 1188 switch (Result.getAmbiguityKind()) { 1189 case LookupResult::AmbiguousBaseSubobjects: { 1190 CXXBasePaths *Paths = Result.getBasePaths(); 1191 QualType SubobjectType = Paths->front().back().Base->getType(); 1192 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) 1193 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) 1194 << LookupRange; 1195 1196 DeclContext::lookup_iterator Found = Paths->front().Decls.first; 1197 while (isa<CXXMethodDecl>(*Found) && 1198 cast<CXXMethodDecl>(*Found)->isStatic()) 1199 ++Found; 1200 1201 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); 1202 1203 return true; 1204 } 1205 1206 case LookupResult::AmbiguousBaseSubobjectTypes: { 1207 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) 1208 << Name << LookupRange; 1209 1210 CXXBasePaths *Paths = Result.getBasePaths(); 1211 std::set<Decl *> DeclsPrinted; 1212 for (CXXBasePaths::paths_iterator Path = Paths->begin(), 1213 PathEnd = Paths->end(); 1214 Path != PathEnd; ++Path) { 1215 Decl *D = *Path->Decls.first; 1216 if (DeclsPrinted.insert(D).second) 1217 Diag(D->getLocation(), diag::note_ambiguous_member_found); 1218 } 1219 1220 return true; 1221 } 1222 1223 case LookupResult::AmbiguousTagHiding: { 1224 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange; 1225 1226 llvm::SmallPtrSet<NamedDecl*,8> TagDecls; 1227 1228 LookupResult::iterator DI, DE = Result.end(); 1229 for (DI = Result.begin(); DI != DE; ++DI) 1230 if (TagDecl *TD = dyn_cast<TagDecl>(*DI)) { 1231 TagDecls.insert(TD); 1232 Diag(TD->getLocation(), diag::note_hidden_tag); 1233 } 1234 1235 for (DI = Result.begin(); DI != DE; ++DI) 1236 if (!isa<TagDecl>(*DI)) 1237 Diag((*DI)->getLocation(), diag::note_hiding_object); 1238 1239 // For recovery purposes, go ahead and implement the hiding. 1240 Result.hideDecls(TagDecls); 1241 1242 return true; 1243 } 1244 1245 case LookupResult::AmbiguousReference: { 1246 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; 1247 1248 LookupResult::iterator DI = Result.begin(), DE = Result.end(); 1249 for (; DI != DE; ++DI) 1250 Diag((*DI)->getLocation(), diag::note_ambiguous_candidate) << *DI; 1251 1252 return true; 1253 } 1254 } 1255 1256 llvm_unreachable("unknown ambiguity kind"); 1257 return true; 1258} 1259 1260static void 1261addAssociatedClassesAndNamespaces(QualType T, 1262 ASTContext &Context, 1263 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1264 Sema::AssociatedClassSet &AssociatedClasses); 1265 1266static void CollectNamespace(Sema::AssociatedNamespaceSet &Namespaces, 1267 DeclContext *Ctx) { 1268 if (Ctx->isFileContext()) 1269 Namespaces.insert(Ctx); 1270} 1271 1272// \brief Add the associated classes and namespaces for argument-dependent 1273// lookup that involves a template argument (C++ [basic.lookup.koenig]p2). 1274static void 1275addAssociatedClassesAndNamespaces(const TemplateArgument &Arg, 1276 ASTContext &Context, 1277 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1278 Sema::AssociatedClassSet &AssociatedClasses) { 1279 // C++ [basic.lookup.koenig]p2, last bullet: 1280 // -- [...] ; 1281 switch (Arg.getKind()) { 1282 case TemplateArgument::Null: 1283 break; 1284 1285 case TemplateArgument::Type: 1286 // [...] the namespaces and classes associated with the types of the 1287 // template arguments provided for template type parameters (excluding 1288 // template template parameters) 1289 addAssociatedClassesAndNamespaces(Arg.getAsType(), Context, 1290 AssociatedNamespaces, 1291 AssociatedClasses); 1292 break; 1293 1294 case TemplateArgument::Template: { 1295 // [...] the namespaces in which any template template arguments are 1296 // defined; and the classes in which any member templates used as 1297 // template template arguments are defined. 1298 TemplateName Template = Arg.getAsTemplate(); 1299 if (ClassTemplateDecl *ClassTemplate 1300 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) { 1301 DeclContext *Ctx = ClassTemplate->getDeclContext(); 1302 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1303 AssociatedClasses.insert(EnclosingClass); 1304 // Add the associated namespace for this class. 1305 while (Ctx->isRecord()) 1306 Ctx = Ctx->getParent(); 1307 CollectNamespace(AssociatedNamespaces, Ctx); 1308 } 1309 break; 1310 } 1311 1312 case TemplateArgument::Declaration: 1313 case TemplateArgument::Integral: 1314 case TemplateArgument::Expression: 1315 // [Note: non-type template arguments do not contribute to the set of 1316 // associated namespaces. ] 1317 break; 1318 1319 case TemplateArgument::Pack: 1320 for (TemplateArgument::pack_iterator P = Arg.pack_begin(), 1321 PEnd = Arg.pack_end(); 1322 P != PEnd; ++P) 1323 addAssociatedClassesAndNamespaces(*P, Context, 1324 AssociatedNamespaces, 1325 AssociatedClasses); 1326 break; 1327 } 1328} 1329 1330// \brief Add the associated classes and namespaces for 1331// argument-dependent lookup with an argument of class type 1332// (C++ [basic.lookup.koenig]p2). 1333static void 1334addAssociatedClassesAndNamespaces(CXXRecordDecl *Class, 1335 ASTContext &Context, 1336 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1337 Sema::AssociatedClassSet &AssociatedClasses) { 1338 // C++ [basic.lookup.koenig]p2: 1339 // [...] 1340 // -- If T is a class type (including unions), its associated 1341 // classes are: the class itself; the class of which it is a 1342 // member, if any; and its direct and indirect base 1343 // classes. Its associated namespaces are the namespaces in 1344 // which its associated classes are defined. 1345 1346 // Add the class of which it is a member, if any. 1347 DeclContext *Ctx = Class->getDeclContext(); 1348 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1349 AssociatedClasses.insert(EnclosingClass); 1350 // Add the associated namespace for this class. 1351 while (Ctx->isRecord()) 1352 Ctx = Ctx->getParent(); 1353 CollectNamespace(AssociatedNamespaces, Ctx); 1354 1355 // Add the class itself. If we've already seen this class, we don't 1356 // need to visit base classes. 1357 if (!AssociatedClasses.insert(Class)) 1358 return; 1359 1360 // -- If T is a template-id, its associated namespaces and classes are 1361 // the namespace in which the template is defined; for member 1362 // templates, the member template’s class; the namespaces and classes 1363 // associated with the types of the template arguments provided for 1364 // template type parameters (excluding template template parameters); the 1365 // namespaces in which any template template arguments are defined; and 1366 // the classes in which any member templates used as template template 1367 // arguments are defined. [Note: non-type template arguments do not 1368 // contribute to the set of associated namespaces. ] 1369 if (ClassTemplateSpecializationDecl *Spec 1370 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) { 1371 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); 1372 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1373 AssociatedClasses.insert(EnclosingClass); 1374 // Add the associated namespace for this class. 1375 while (Ctx->isRecord()) 1376 Ctx = Ctx->getParent(); 1377 CollectNamespace(AssociatedNamespaces, Ctx); 1378 1379 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); 1380 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 1381 addAssociatedClassesAndNamespaces(TemplateArgs[I], Context, 1382 AssociatedNamespaces, 1383 AssociatedClasses); 1384 } 1385 1386 // Add direct and indirect base classes along with their associated 1387 // namespaces. 1388 llvm::SmallVector<CXXRecordDecl *, 32> Bases; 1389 Bases.push_back(Class); 1390 while (!Bases.empty()) { 1391 // Pop this class off the stack. 1392 Class = Bases.back(); 1393 Bases.pop_back(); 1394 1395 // Visit the base classes. 1396 for (CXXRecordDecl::base_class_iterator Base = Class->bases_begin(), 1397 BaseEnd = Class->bases_end(); 1398 Base != BaseEnd; ++Base) { 1399 const RecordType *BaseType = Base->getType()->getAs<RecordType>(); 1400 // In dependent contexts, we do ADL twice, and the first time around, 1401 // the base type might be a dependent TemplateSpecializationType, or a 1402 // TemplateTypeParmType. If that happens, simply ignore it. 1403 // FIXME: If we want to support export, we probably need to add the 1404 // namespace of the template in a TemplateSpecializationType, or even 1405 // the classes and namespaces of known non-dependent arguments. 1406 if (!BaseType) 1407 continue; 1408 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 1409 if (AssociatedClasses.insert(BaseDecl)) { 1410 // Find the associated namespace for this base class. 1411 DeclContext *BaseCtx = BaseDecl->getDeclContext(); 1412 while (BaseCtx->isRecord()) 1413 BaseCtx = BaseCtx->getParent(); 1414 CollectNamespace(AssociatedNamespaces, BaseCtx); 1415 1416 // Make sure we visit the bases of this base class. 1417 if (BaseDecl->bases_begin() != BaseDecl->bases_end()) 1418 Bases.push_back(BaseDecl); 1419 } 1420 } 1421 } 1422} 1423 1424// \brief Add the associated classes and namespaces for 1425// argument-dependent lookup with an argument of type T 1426// (C++ [basic.lookup.koenig]p2). 1427static void 1428addAssociatedClassesAndNamespaces(QualType T, 1429 ASTContext &Context, 1430 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1431 Sema::AssociatedClassSet &AssociatedClasses) { 1432 // C++ [basic.lookup.koenig]p2: 1433 // 1434 // For each argument type T in the function call, there is a set 1435 // of zero or more associated namespaces and a set of zero or more 1436 // associated classes to be considered. The sets of namespaces and 1437 // classes is determined entirely by the types of the function 1438 // arguments (and the namespace of any template template 1439 // argument). Typedef names and using-declarations used to specify 1440 // the types do not contribute to this set. The sets of namespaces 1441 // and classes are determined in the following way: 1442 T = Context.getCanonicalType(T).getUnqualifiedType(); 1443 1444 // -- If T is a pointer to U or an array of U, its associated 1445 // namespaces and classes are those associated with U. 1446 // 1447 // We handle this by unwrapping pointer and array types immediately, 1448 // to avoid unnecessary recursion. 1449 while (true) { 1450 if (const PointerType *Ptr = T->getAs<PointerType>()) 1451 T = Ptr->getPointeeType(); 1452 else if (const ArrayType *Ptr = Context.getAsArrayType(T)) 1453 T = Ptr->getElementType(); 1454 else 1455 break; 1456 } 1457 1458 // -- If T is a fundamental type, its associated sets of 1459 // namespaces and classes are both empty. 1460 if (T->getAs<BuiltinType>()) 1461 return; 1462 1463 // -- If T is a class type (including unions), its associated 1464 // classes are: the class itself; the class of which it is a 1465 // member, if any; and its direct and indirect base 1466 // classes. Its associated namespaces are the namespaces in 1467 // which its associated classes are defined. 1468 if (const RecordType *ClassType = T->getAs<RecordType>()) 1469 if (CXXRecordDecl *ClassDecl 1470 = dyn_cast<CXXRecordDecl>(ClassType->getDecl())) { 1471 addAssociatedClassesAndNamespaces(ClassDecl, Context, 1472 AssociatedNamespaces, 1473 AssociatedClasses); 1474 return; 1475 } 1476 1477 // -- If T is an enumeration type, its associated namespace is 1478 // the namespace in which it is defined. If it is class 1479 // member, its associated class is the member’s class; else 1480 // it has no associated class. 1481 if (const EnumType *EnumT = T->getAs<EnumType>()) { 1482 EnumDecl *Enum = EnumT->getDecl(); 1483 1484 DeclContext *Ctx = Enum->getDeclContext(); 1485 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1486 AssociatedClasses.insert(EnclosingClass); 1487 1488 // Add the associated namespace for this class. 1489 while (Ctx->isRecord()) 1490 Ctx = Ctx->getParent(); 1491 CollectNamespace(AssociatedNamespaces, Ctx); 1492 1493 return; 1494 } 1495 1496 // -- If T is a function type, its associated namespaces and 1497 // classes are those associated with the function parameter 1498 // types and those associated with the return type. 1499 if (const FunctionType *FnType = T->getAs<FunctionType>()) { 1500 // Return type 1501 addAssociatedClassesAndNamespaces(FnType->getResultType(), 1502 Context, 1503 AssociatedNamespaces, AssociatedClasses); 1504 1505 const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FnType); 1506 if (!Proto) 1507 return; 1508 1509 // Argument types 1510 for (FunctionProtoType::arg_type_iterator Arg = Proto->arg_type_begin(), 1511 ArgEnd = Proto->arg_type_end(); 1512 Arg != ArgEnd; ++Arg) 1513 addAssociatedClassesAndNamespaces(*Arg, Context, 1514 AssociatedNamespaces, AssociatedClasses); 1515 1516 return; 1517 } 1518 1519 // -- If T is a pointer to a member function of a class X, its 1520 // associated namespaces and classes are those associated 1521 // with the function parameter types and return type, 1522 // together with those associated with X. 1523 // 1524 // -- If T is a pointer to a data member of class X, its 1525 // associated namespaces and classes are those associated 1526 // with the member type together with those associated with 1527 // X. 1528 if (const MemberPointerType *MemberPtr = T->getAs<MemberPointerType>()) { 1529 // Handle the type that the pointer to member points to. 1530 addAssociatedClassesAndNamespaces(MemberPtr->getPointeeType(), 1531 Context, 1532 AssociatedNamespaces, 1533 AssociatedClasses); 1534 1535 // Handle the class type into which this points. 1536 if (const RecordType *Class = MemberPtr->getClass()->getAs<RecordType>()) 1537 addAssociatedClassesAndNamespaces(cast<CXXRecordDecl>(Class->getDecl()), 1538 Context, 1539 AssociatedNamespaces, 1540 AssociatedClasses); 1541 1542 return; 1543 } 1544 1545 // FIXME: What about block pointers? 1546 // FIXME: What about Objective-C message sends? 1547} 1548 1549/// \brief Find the associated classes and namespaces for 1550/// argument-dependent lookup for a call with the given set of 1551/// arguments. 1552/// 1553/// This routine computes the sets of associated classes and associated 1554/// namespaces searched by argument-dependent lookup 1555/// (C++ [basic.lookup.argdep]) for a given set of arguments. 1556void 1557Sema::FindAssociatedClassesAndNamespaces(Expr **Args, unsigned NumArgs, 1558 AssociatedNamespaceSet &AssociatedNamespaces, 1559 AssociatedClassSet &AssociatedClasses) { 1560 AssociatedNamespaces.clear(); 1561 AssociatedClasses.clear(); 1562 1563 // C++ [basic.lookup.koenig]p2: 1564 // For each argument type T in the function call, there is a set 1565 // of zero or more associated namespaces and a set of zero or more 1566 // associated classes to be considered. The sets of namespaces and 1567 // classes is determined entirely by the types of the function 1568 // arguments (and the namespace of any template template 1569 // argument). 1570 for (unsigned ArgIdx = 0; ArgIdx != NumArgs; ++ArgIdx) { 1571 Expr *Arg = Args[ArgIdx]; 1572 1573 if (Arg->getType() != Context.OverloadTy) { 1574 addAssociatedClassesAndNamespaces(Arg->getType(), Context, 1575 AssociatedNamespaces, 1576 AssociatedClasses); 1577 continue; 1578 } 1579 1580 // [...] In addition, if the argument is the name or address of a 1581 // set of overloaded functions and/or function templates, its 1582 // associated classes and namespaces are the union of those 1583 // associated with each of the members of the set: the namespace 1584 // in which the function or function template is defined and the 1585 // classes and namespaces associated with its (non-dependent) 1586 // parameter types and return type. 1587 Arg = Arg->IgnoreParens(); 1588 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg)) 1589 if (unaryOp->getOpcode() == UnaryOperator::AddrOf) 1590 Arg = unaryOp->getSubExpr(); 1591 1592 // TODO: avoid the copies. This should be easy when the cases 1593 // share a storage implementation. 1594 llvm::SmallVector<NamedDecl*, 8> Functions; 1595 1596 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg)) 1597 Functions.append(ULE->decls_begin(), ULE->decls_end()); 1598 else 1599 continue; 1600 1601 for (llvm::SmallVectorImpl<NamedDecl*>::iterator I = Functions.begin(), 1602 E = Functions.end(); I != E; ++I) { 1603 // Look through any using declarations to find the underlying function. 1604 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 1605 1606 FunctionDecl *FDecl = dyn_cast<FunctionDecl>(Fn); 1607 if (!FDecl) 1608 FDecl = cast<FunctionTemplateDecl>(Fn)->getTemplatedDecl(); 1609 1610 // Add the classes and namespaces associated with the parameter 1611 // types and return type of this function. 1612 addAssociatedClassesAndNamespaces(FDecl->getType(), Context, 1613 AssociatedNamespaces, 1614 AssociatedClasses); 1615 } 1616 } 1617} 1618 1619/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is 1620/// an acceptable non-member overloaded operator for a call whose 1621/// arguments have types T1 (and, if non-empty, T2). This routine 1622/// implements the check in C++ [over.match.oper]p3b2 concerning 1623/// enumeration types. 1624static bool 1625IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn, 1626 QualType T1, QualType T2, 1627 ASTContext &Context) { 1628 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType())) 1629 return true; 1630 1631 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType())) 1632 return true; 1633 1634 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>(); 1635 if (Proto->getNumArgs() < 1) 1636 return false; 1637 1638 if (T1->isEnumeralType()) { 1639 QualType ArgType = Proto->getArgType(0).getNonReferenceType(); 1640 if (Context.hasSameUnqualifiedType(T1, ArgType)) 1641 return true; 1642 } 1643 1644 if (Proto->getNumArgs() < 2) 1645 return false; 1646 1647 if (!T2.isNull() && T2->isEnumeralType()) { 1648 QualType ArgType = Proto->getArgType(1).getNonReferenceType(); 1649 if (Context.hasSameUnqualifiedType(T2, ArgType)) 1650 return true; 1651 } 1652 1653 return false; 1654} 1655 1656NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name, 1657 LookupNameKind NameKind, 1658 RedeclarationKind Redecl) { 1659 LookupResult R(*this, Name, SourceLocation(), NameKind, Redecl); 1660 LookupName(R, S); 1661 return R.getAsSingle<NamedDecl>(); 1662} 1663 1664/// \brief Find the protocol with the given name, if any. 1665ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II) { 1666 Decl *D = LookupSingleName(TUScope, II, LookupObjCProtocolName); 1667 return cast_or_null<ObjCProtocolDecl>(D); 1668} 1669 1670void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, 1671 QualType T1, QualType T2, 1672 FunctionSet &Functions) { 1673 // C++ [over.match.oper]p3: 1674 // -- The set of non-member candidates is the result of the 1675 // unqualified lookup of operator@ in the context of the 1676 // expression according to the usual rules for name lookup in 1677 // unqualified function calls (3.4.2) except that all member 1678 // functions are ignored. However, if no operand has a class 1679 // type, only those non-member functions in the lookup set 1680 // that have a first parameter of type T1 or "reference to 1681 // (possibly cv-qualified) T1", when T1 is an enumeration 1682 // type, or (if there is a right operand) a second parameter 1683 // of type T2 or "reference to (possibly cv-qualified) T2", 1684 // when T2 is an enumeration type, are candidate functions. 1685 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 1686 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName); 1687 LookupName(Operators, S); 1688 1689 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); 1690 1691 if (Operators.empty()) 1692 return; 1693 1694 for (LookupResult::iterator Op = Operators.begin(), OpEnd = Operators.end(); 1695 Op != OpEnd; ++Op) { 1696 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Op)) { 1697 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context)) 1698 Functions.insert(FD); // FIXME: canonical FD 1699 } else if (FunctionTemplateDecl *FunTmpl 1700 = dyn_cast<FunctionTemplateDecl>(*Op)) { 1701 // FIXME: friend operators? 1702 // FIXME: do we need to check IsAcceptableNonMemberOperatorCandidate, 1703 // later? 1704 if (!FunTmpl->getDeclContext()->isRecord()) 1705 Functions.insert(FunTmpl); 1706 } 1707 } 1708} 1709 1710static void CollectFunctionDecl(Sema::FunctionSet &Functions, 1711 Decl *D) { 1712 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(D)) 1713 Functions.insert(Func); 1714 else if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D)) 1715 Functions.insert(FunTmpl); 1716} 1717 1718void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator, 1719 Expr **Args, unsigned NumArgs, 1720 FunctionSet &Functions) { 1721 // Find all of the associated namespaces and classes based on the 1722 // arguments we have. 1723 AssociatedNamespaceSet AssociatedNamespaces; 1724 AssociatedClassSet AssociatedClasses; 1725 FindAssociatedClassesAndNamespaces(Args, NumArgs, 1726 AssociatedNamespaces, 1727 AssociatedClasses); 1728 1729 QualType T1, T2; 1730 if (Operator) { 1731 T1 = Args[0]->getType(); 1732 if (NumArgs >= 2) 1733 T2 = Args[1]->getType(); 1734 } 1735 1736 // C++ [basic.lookup.argdep]p3: 1737 // Let X be the lookup set produced by unqualified lookup (3.4.1) 1738 // and let Y be the lookup set produced by argument dependent 1739 // lookup (defined as follows). If X contains [...] then Y is 1740 // empty. Otherwise Y is the set of declarations found in the 1741 // namespaces associated with the argument types as described 1742 // below. The set of declarations found by the lookup of the name 1743 // is the union of X and Y. 1744 // 1745 // Here, we compute Y and add its members to the overloaded 1746 // candidate set. 1747 for (AssociatedNamespaceSet::iterator NS = AssociatedNamespaces.begin(), 1748 NSEnd = AssociatedNamespaces.end(); 1749 NS != NSEnd; ++NS) { 1750 // When considering an associated namespace, the lookup is the 1751 // same as the lookup performed when the associated namespace is 1752 // used as a qualifier (3.4.3.2) except that: 1753 // 1754 // -- Any using-directives in the associated namespace are 1755 // ignored. 1756 // 1757 // -- Any namespace-scope friend functions declared in 1758 // associated classes are visible within their respective 1759 // namespaces even if they are not visible during an ordinary 1760 // lookup (11.4). 1761 DeclContext::lookup_iterator I, E; 1762 for (llvm::tie(I, E) = (*NS)->lookup(Name); I != E; ++I) { 1763 Decl *D = *I; 1764 // If the only declaration here is an ordinary friend, consider 1765 // it only if it was declared in an associated classes. 1766 if (D->getIdentifierNamespace() == Decl::IDNS_OrdinaryFriend) { 1767 DeclContext *LexDC = D->getLexicalDeclContext(); 1768 if (!AssociatedClasses.count(cast<CXXRecordDecl>(LexDC))) 1769 continue; 1770 } 1771 1772 FunctionDecl *Fn; 1773 if (!Operator || !(Fn = dyn_cast<FunctionDecl>(D)) || 1774 IsAcceptableNonMemberOperatorCandidate(Fn, T1, T2, Context)) 1775 CollectFunctionDecl(Functions, D); 1776 } 1777 } 1778} 1779 1780//---------------------------------------------------------------------------- 1781// Search for all visible declarations. 1782//---------------------------------------------------------------------------- 1783VisibleDeclConsumer::~VisibleDeclConsumer() { } 1784 1785namespace { 1786 1787class ShadowContextRAII; 1788 1789class VisibleDeclsRecord { 1790public: 1791 /// \brief An entry in the shadow map, which is optimized to store a 1792 /// single declaration (the common case) but can also store a list 1793 /// of declarations. 1794 class ShadowMapEntry { 1795 typedef llvm::SmallVector<NamedDecl *, 4> DeclVector; 1796 1797 /// \brief Contains either the solitary NamedDecl * or a vector 1798 /// of declarations. 1799 llvm::PointerUnion<NamedDecl *, DeclVector*> DeclOrVector; 1800 1801 public: 1802 ShadowMapEntry() : DeclOrVector() { } 1803 1804 void Add(NamedDecl *ND); 1805 void Destroy(); 1806 1807 // Iteration. 1808 typedef NamedDecl **iterator; 1809 iterator begin(); 1810 iterator end(); 1811 }; 1812 1813private: 1814 /// \brief A mapping from declaration names to the declarations that have 1815 /// this name within a particular scope. 1816 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap; 1817 1818 /// \brief A list of shadow maps, which is used to model name hiding. 1819 std::list<ShadowMap> ShadowMaps; 1820 1821 /// \brief The declaration contexts we have already visited. 1822 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts; 1823 1824 friend class ShadowContextRAII; 1825 1826public: 1827 /// \brief Determine whether we have already visited this context 1828 /// (and, if not, note that we are going to visit that context now). 1829 bool visitedContext(DeclContext *Ctx) { 1830 return !VisitedContexts.insert(Ctx); 1831 } 1832 1833 /// \brief Determine whether the given declaration is hidden in the 1834 /// current scope. 1835 /// 1836 /// \returns the declaration that hides the given declaration, or 1837 /// NULL if no such declaration exists. 1838 NamedDecl *checkHidden(NamedDecl *ND); 1839 1840 /// \brief Add a declaration to the current shadow map. 1841 void add(NamedDecl *ND) { ShadowMaps.back()[ND->getDeclName()].Add(ND); } 1842}; 1843 1844/// \brief RAII object that records when we've entered a shadow context. 1845class ShadowContextRAII { 1846 VisibleDeclsRecord &Visible; 1847 1848 typedef VisibleDeclsRecord::ShadowMap ShadowMap; 1849 1850public: 1851 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) { 1852 Visible.ShadowMaps.push_back(ShadowMap()); 1853 } 1854 1855 ~ShadowContextRAII() { 1856 for (ShadowMap::iterator E = Visible.ShadowMaps.back().begin(), 1857 EEnd = Visible.ShadowMaps.back().end(); 1858 E != EEnd; 1859 ++E) 1860 E->second.Destroy(); 1861 1862 Visible.ShadowMaps.pop_back(); 1863 } 1864}; 1865 1866} // end anonymous namespace 1867 1868void VisibleDeclsRecord::ShadowMapEntry::Add(NamedDecl *ND) { 1869 if (DeclOrVector.isNull()) { 1870 // 0 - > 1 elements: just set the single element information. 1871 DeclOrVector = ND; 1872 return; 1873 } 1874 1875 if (NamedDecl *PrevND = DeclOrVector.dyn_cast<NamedDecl *>()) { 1876 // 1 -> 2 elements: create the vector of results and push in the 1877 // existing declaration. 1878 DeclVector *Vec = new DeclVector; 1879 Vec->push_back(PrevND); 1880 DeclOrVector = Vec; 1881 } 1882 1883 // Add the new element to the end of the vector. 1884 DeclOrVector.get<DeclVector*>()->push_back(ND); 1885} 1886 1887void VisibleDeclsRecord::ShadowMapEntry::Destroy() { 1888 if (DeclVector *Vec = DeclOrVector.dyn_cast<DeclVector *>()) { 1889 delete Vec; 1890 DeclOrVector = ((NamedDecl *)0); 1891 } 1892} 1893 1894VisibleDeclsRecord::ShadowMapEntry::iterator 1895VisibleDeclsRecord::ShadowMapEntry::begin() { 1896 if (DeclOrVector.isNull()) 1897 return 0; 1898 1899 if (DeclOrVector.dyn_cast<NamedDecl *>()) 1900 return &reinterpret_cast<NamedDecl*&>(DeclOrVector); 1901 1902 return DeclOrVector.get<DeclVector *>()->begin(); 1903} 1904 1905VisibleDeclsRecord::ShadowMapEntry::iterator 1906VisibleDeclsRecord::ShadowMapEntry::end() { 1907 if (DeclOrVector.isNull()) 1908 return 0; 1909 1910 if (DeclOrVector.dyn_cast<NamedDecl *>()) 1911 return &reinterpret_cast<NamedDecl*&>(DeclOrVector) + 1; 1912 1913 return DeclOrVector.get<DeclVector *>()->end(); 1914} 1915 1916NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) { 1917 unsigned IDNS = ND->getIdentifierNamespace(); 1918 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin(); 1919 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend(); 1920 SM != SMEnd; ++SM) { 1921 ShadowMap::iterator Pos = SM->find(ND->getDeclName()); 1922 if (Pos == SM->end()) 1923 continue; 1924 1925 for (ShadowMapEntry::iterator I = Pos->second.begin(), 1926 IEnd = Pos->second.end(); 1927 I != IEnd; ++I) { 1928 // A tag declaration does not hide a non-tag declaration. 1929 if ((*I)->getIdentifierNamespace() == Decl::IDNS_Tag && 1930 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary | 1931 Decl::IDNS_ObjCProtocol))) 1932 continue; 1933 1934 // Protocols are in distinct namespaces from everything else. 1935 if ((((*I)->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol) 1936 || (IDNS & Decl::IDNS_ObjCProtocol)) && 1937 (*I)->getIdentifierNamespace() != IDNS) 1938 continue; 1939 1940 // We've found a declaration that hides this one. 1941 return *I; 1942 } 1943 } 1944 1945 return 0; 1946} 1947 1948static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result, 1949 bool QualifiedNameLookup, 1950 VisibleDeclConsumer &Consumer, 1951 VisibleDeclsRecord &Visited) { 1952 // Make sure we don't visit the same context twice. 1953 if (Visited.visitedContext(Ctx->getPrimaryContext())) 1954 return; 1955 1956 // Enumerate all of the results in this context. 1957 for (DeclContext *CurCtx = Ctx->getPrimaryContext(); CurCtx; 1958 CurCtx = CurCtx->getNextContext()) { 1959 for (DeclContext::decl_iterator D = CurCtx->decls_begin(), 1960 DEnd = CurCtx->decls_end(); 1961 D != DEnd; ++D) { 1962 if (NamedDecl *ND = dyn_cast<NamedDecl>(*D)) 1963 if (Result.isAcceptableDecl(ND)) { 1964 Consumer.FoundDecl(ND, Visited.checkHidden(ND)); 1965 Visited.add(ND); 1966 } 1967 1968 // Visit transparent contexts inside this context. 1969 if (DeclContext *InnerCtx = dyn_cast<DeclContext>(*D)) { 1970 if (InnerCtx->isTransparentContext()) 1971 LookupVisibleDecls(InnerCtx, Result, QualifiedNameLookup, 1972 Consumer, Visited); 1973 } 1974 } 1975 } 1976 1977 // Traverse using directives for qualified name lookup. 1978 if (QualifiedNameLookup) { 1979 ShadowContextRAII Shadow(Visited); 1980 DeclContext::udir_iterator I, E; 1981 for (llvm::tie(I, E) = Ctx->getUsingDirectives(); I != E; ++I) { 1982 LookupVisibleDecls((*I)->getNominatedNamespace(), Result, 1983 QualifiedNameLookup, Consumer, Visited); 1984 } 1985 } 1986 1987 // Traverse the contexts of inherited C++ classes. 1988 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) { 1989 for (CXXRecordDecl::base_class_iterator B = Record->bases_begin(), 1990 BEnd = Record->bases_end(); 1991 B != BEnd; ++B) { 1992 QualType BaseType = B->getType(); 1993 1994 // Don't look into dependent bases, because name lookup can't look 1995 // there anyway. 1996 if (BaseType->isDependentType()) 1997 continue; 1998 1999 const RecordType *Record = BaseType->getAs<RecordType>(); 2000 if (!Record) 2001 continue; 2002 2003 // FIXME: It would be nice to be able to determine whether referencing 2004 // a particular member would be ambiguous. For example, given 2005 // 2006 // struct A { int member; }; 2007 // struct B { int member; }; 2008 // struct C : A, B { }; 2009 // 2010 // void f(C *c) { c->### } 2011 // 2012 // accessing 'member' would result in an ambiguity. However, we 2013 // could be smart enough to qualify the member with the base 2014 // class, e.g., 2015 // 2016 // c->B::member 2017 // 2018 // or 2019 // 2020 // c->A::member 2021 2022 // Find results in this base class (and its bases). 2023 ShadowContextRAII Shadow(Visited); 2024 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup, 2025 Consumer, Visited); 2026 } 2027 } 2028 2029 // Traverse the contexts of Objective-C classes. 2030 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) { 2031 // Traverse categories. 2032 for (ObjCCategoryDecl *Category = IFace->getCategoryList(); 2033 Category; Category = Category->getNextClassCategory()) { 2034 ShadowContextRAII Shadow(Visited); 2035 LookupVisibleDecls(Category, Result, QualifiedNameLookup, Consumer, 2036 Visited); 2037 } 2038 2039 // Traverse protocols. 2040 for (ObjCInterfaceDecl::protocol_iterator I = IFace->protocol_begin(), 2041 E = IFace->protocol_end(); I != E; ++I) { 2042 ShadowContextRAII Shadow(Visited); 2043 LookupVisibleDecls(*I, Result, QualifiedNameLookup, Consumer, Visited); 2044 } 2045 2046 // Traverse the superclass. 2047 if (IFace->getSuperClass()) { 2048 ShadowContextRAII Shadow(Visited); 2049 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup, 2050 Consumer, Visited); 2051 } 2052 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) { 2053 for (ObjCProtocolDecl::protocol_iterator I = Protocol->protocol_begin(), 2054 E = Protocol->protocol_end(); I != E; ++I) { 2055 ShadowContextRAII Shadow(Visited); 2056 LookupVisibleDecls(*I, Result, QualifiedNameLookup, Consumer, Visited); 2057 } 2058 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) { 2059 for (ObjCCategoryDecl::protocol_iterator I = Category->protocol_begin(), 2060 E = Category->protocol_end(); I != E; ++I) { 2061 ShadowContextRAII Shadow(Visited); 2062 LookupVisibleDecls(*I, Result, QualifiedNameLookup, Consumer, Visited); 2063 } 2064 } 2065} 2066 2067static void LookupVisibleDecls(Scope *S, LookupResult &Result, 2068 UnqualUsingDirectiveSet &UDirs, 2069 VisibleDeclConsumer &Consumer, 2070 VisibleDeclsRecord &Visited) { 2071 if (!S) 2072 return; 2073 2074 if (!S->getEntity() || !S->getParent() || 2075 ((DeclContext *)S->getEntity())->isFunctionOrMethod()) { 2076 // Walk through the declarations in this Scope. 2077 for (Scope::decl_iterator D = S->decl_begin(), DEnd = S->decl_end(); 2078 D != DEnd; ++D) { 2079 if (NamedDecl *ND = dyn_cast<NamedDecl>((Decl *)((*D).get()))) 2080 if (Result.isAcceptableDecl(ND)) { 2081 Consumer.FoundDecl(ND, Visited.checkHidden(ND)); 2082 Visited.add(ND); 2083 } 2084 } 2085 } 2086 2087 DeclContext *Entity = 0; 2088 if (S->getEntity()) { 2089 // Look into this scope's declaration context, along with any of its 2090 // parent lookup contexts (e.g., enclosing classes), up to the point 2091 // where we hit the context stored in the next outer scope. 2092 Entity = (DeclContext *)S->getEntity(); 2093 DeclContext *OuterCtx = findOuterContext(S); 2094 2095 for (DeclContext *Ctx = Entity; Ctx && Ctx->getPrimaryContext() != OuterCtx; 2096 Ctx = Ctx->getLookupParent()) { 2097 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 2098 if (Method->isInstanceMethod()) { 2099 // For instance methods, look for ivars in the method's interface. 2100 LookupResult IvarResult(Result.getSema(), Result.getLookupName(), 2101 Result.getNameLoc(), Sema::LookupMemberName); 2102 ObjCInterfaceDecl *IFace = Method->getClassInterface(); 2103 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false, 2104 Consumer, Visited); 2105 } 2106 2107 // We've already performed all of the name lookup that we need 2108 // to for Objective-C methods; the next context will be the 2109 // outer scope. 2110 break; 2111 } 2112 2113 if (Ctx->isFunctionOrMethod()) 2114 continue; 2115 2116 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false, 2117 Consumer, Visited); 2118 } 2119 } else if (!S->getParent()) { 2120 // Look into the translation unit scope. We walk through the translation 2121 // unit's declaration context, because the Scope itself won't have all of 2122 // the declarations if we loaded a precompiled header. 2123 // FIXME: We would like the translation unit's Scope object to point to the 2124 // translation unit, so we don't need this special "if" branch. However, 2125 // doing so would force the normal C++ name-lookup code to look into the 2126 // translation unit decl when the IdentifierInfo chains would suffice. 2127 // Once we fix that problem (which is part of a more general "don't look 2128 // in DeclContexts unless we have to" optimization), we can eliminate this. 2129 Entity = Result.getSema().Context.getTranslationUnitDecl(); 2130 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false, 2131 Consumer, Visited); 2132 } 2133 2134 if (Entity) { 2135 // Lookup visible declarations in any namespaces found by using 2136 // directives. 2137 UnqualUsingDirectiveSet::const_iterator UI, UEnd; 2138 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(Entity); 2139 for (; UI != UEnd; ++UI) 2140 LookupVisibleDecls(const_cast<DeclContext *>(UI->getNominatedNamespace()), 2141 Result, /*QualifiedNameLookup=*/false, Consumer, 2142 Visited); 2143 } 2144 2145 // Lookup names in the parent scope. 2146 ShadowContextRAII Shadow(Visited); 2147 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited); 2148} 2149 2150void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind, 2151 VisibleDeclConsumer &Consumer) { 2152 // Determine the set of using directives available during 2153 // unqualified name lookup. 2154 Scope *Initial = S; 2155 UnqualUsingDirectiveSet UDirs; 2156 if (getLangOptions().CPlusPlus) { 2157 // Find the first namespace or translation-unit scope. 2158 while (S && !isNamespaceOrTranslationUnitScope(S)) 2159 S = S->getParent(); 2160 2161 UDirs.visitScopeChain(Initial, S); 2162 } 2163 UDirs.done(); 2164 2165 // Look for visible declarations. 2166 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2167 VisibleDeclsRecord Visited; 2168 ShadowContextRAII Shadow(Visited); 2169 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited); 2170} 2171 2172void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind, 2173 VisibleDeclConsumer &Consumer) { 2174 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2175 VisibleDeclsRecord Visited; 2176 ShadowContextRAII Shadow(Visited); 2177 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true, Consumer, 2178 Visited); 2179} 2180 2181//---------------------------------------------------------------------------- 2182// Typo correction 2183//---------------------------------------------------------------------------- 2184 2185namespace { 2186class TypoCorrectionConsumer : public VisibleDeclConsumer { 2187 /// \brief The name written that is a typo in the source. 2188 llvm::StringRef Typo; 2189 2190 /// \brief The results found that have the smallest edit distance 2191 /// found (so far) with the typo name. 2192 llvm::SmallVector<NamedDecl *, 4> BestResults; 2193 2194 /// \brief The best edit distance found so far. 2195 unsigned BestEditDistance; 2196 2197public: 2198 explicit TypoCorrectionConsumer(IdentifierInfo *Typo) 2199 : Typo(Typo->getName()) { } 2200 2201 virtual void FoundDecl(NamedDecl *ND, NamedDecl *Hiding); 2202 2203 typedef llvm::SmallVector<NamedDecl *, 4>::const_iterator iterator; 2204 iterator begin() const { return BestResults.begin(); } 2205 iterator end() const { return BestResults.end(); } 2206 bool empty() const { return BestResults.empty(); } 2207 2208 unsigned getBestEditDistance() const { return BestEditDistance; } 2209}; 2210 2211} 2212 2213void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding) { 2214 // Don't consider hidden names for typo correction. 2215 if (Hiding) 2216 return; 2217 2218 // Only consider entities with identifiers for names, ignoring 2219 // special names (constructors, overloaded operators, selectors, 2220 // etc.). 2221 IdentifierInfo *Name = ND->getIdentifier(); 2222 if (!Name) 2223 return; 2224 2225 // Compute the edit distance between the typo and the name of this 2226 // entity. If this edit distance is not worse than the best edit 2227 // distance we've seen so far, add it to the list of results. 2228 unsigned ED = Typo.edit_distance(Name->getName()); 2229 if (!BestResults.empty()) { 2230 if (ED < BestEditDistance) { 2231 // This result is better than any we've seen before; clear out 2232 // the previous results. 2233 BestResults.clear(); 2234 BestEditDistance = ED; 2235 } else if (ED > BestEditDistance) { 2236 // This result is worse than the best results we've seen so far; 2237 // ignore it. 2238 return; 2239 } 2240 } else 2241 BestEditDistance = ED; 2242 2243 BestResults.push_back(ND); 2244} 2245 2246/// \brief Try to "correct" a typo in the source code by finding 2247/// visible declarations whose names are similar to the name that was 2248/// present in the source code. 2249/// 2250/// \param Res the \c LookupResult structure that contains the name 2251/// that was present in the source code along with the name-lookup 2252/// criteria used to search for the name. On success, this structure 2253/// will contain the results of name lookup. 2254/// 2255/// \param S the scope in which name lookup occurs. 2256/// 2257/// \param SS the nested-name-specifier that precedes the name we're 2258/// looking for, if present. 2259/// 2260/// \param MemberContext if non-NULL, the context in which to look for 2261/// a member access expression. 2262/// 2263/// \param EnteringContext whether we're entering the context described by 2264/// the nested-name-specifier SS. 2265/// 2266/// \param OPT when non-NULL, the search for visible declarations will 2267/// also walk the protocols in the qualified interfaces of \p OPT. 2268/// 2269/// \returns true if the typo was corrected, in which case the \p Res 2270/// structure will contain the results of name lookup for the 2271/// corrected name. Otherwise, returns false. 2272bool Sema::CorrectTypo(LookupResult &Res, Scope *S, const CXXScopeSpec *SS, 2273 DeclContext *MemberContext, bool EnteringContext, 2274 const ObjCObjectPointerType *OPT) { 2275 2276 if (Diags.hasFatalErrorOccurred()) 2277 return false; 2278 2279 // We only attempt to correct typos for identifiers. 2280 IdentifierInfo *Typo = Res.getLookupName().getAsIdentifierInfo(); 2281 if (!Typo) 2282 return false; 2283 2284 // If the scope specifier itself was invalid, don't try to correct 2285 // typos. 2286 if (SS && SS->isInvalid()) 2287 return false; 2288 2289 // Never try to correct typos during template deduction or 2290 // instantiation. 2291 if (!ActiveTemplateInstantiations.empty()) 2292 return false; 2293 2294 TypoCorrectionConsumer Consumer(Typo); 2295 if (MemberContext) { 2296 LookupVisibleDecls(MemberContext, Res.getLookupKind(), Consumer); 2297 2298 // Look in qualified interfaces. 2299 if (OPT) { 2300 for (ObjCObjectPointerType::qual_iterator 2301 I = OPT->qual_begin(), E = OPT->qual_end(); 2302 I != E; ++I) 2303 LookupVisibleDecls(*I, Res.getLookupKind(), Consumer); 2304 } 2305 } else if (SS && SS->isSet()) { 2306 DeclContext *DC = computeDeclContext(*SS, EnteringContext); 2307 if (!DC) 2308 return false; 2309 2310 LookupVisibleDecls(DC, Res.getLookupKind(), Consumer); 2311 } else { 2312 LookupVisibleDecls(S, Res.getLookupKind(), Consumer); 2313 } 2314 2315 if (Consumer.empty()) 2316 return false; 2317 2318 // Only allow a single, closest name in the result set (it's okay to 2319 // have overloads of that name, though). 2320 TypoCorrectionConsumer::iterator I = Consumer.begin(); 2321 DeclarationName BestName = (*I)->getDeclName(); 2322 2323 // If we've found an Objective-C ivar or property, don't perform 2324 // name lookup again; we'll just return the result directly. 2325 NamedDecl *FoundBest = 0; 2326 if (isa<ObjCIvarDecl>(*I) || isa<ObjCPropertyDecl>(*I)) 2327 FoundBest = *I; 2328 ++I; 2329 for(TypoCorrectionConsumer::iterator IEnd = Consumer.end(); I != IEnd; ++I) { 2330 if (BestName != (*I)->getDeclName()) 2331 return false; 2332 2333 // FIXME: If there are both ivars and properties of the same name, 2334 // don't return both because the callee can't handle two 2335 // results. We really need to separate ivar lookup from property 2336 // lookup to avoid this problem. 2337 FoundBest = 0; 2338 } 2339 2340 // BestName is the closest viable name to what the user 2341 // typed. However, to make sure that we don't pick something that's 2342 // way off, make sure that the user typed at least 3 characters for 2343 // each correction. 2344 unsigned ED = Consumer.getBestEditDistance(); 2345 if (ED == 0 || (BestName.getAsIdentifierInfo()->getName().size() / ED) < 3) 2346 return false; 2347 2348 // Perform name lookup again with the name we chose, and declare 2349 // success if we found something that was not ambiguous. 2350 Res.clear(); 2351 Res.setLookupName(BestName); 2352 2353 // If we found an ivar or property, add that result; no further 2354 // lookup is required. 2355 if (FoundBest) 2356 Res.addDecl(FoundBest); 2357 // If we're looking into the context of a member, perform qualified 2358 // name lookup on the best name. 2359 else if (MemberContext) 2360 LookupQualifiedName(Res, MemberContext); 2361 // Perform lookup as if we had just parsed the best name. 2362 else 2363 LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false, 2364 EnteringContext); 2365 2366 if (Res.isAmbiguous()) { 2367 Res.suppressDiagnostics(); 2368 return false; 2369 } 2370 2371 return Res.getResultKind() != LookupResult::NotFound; 2372} 2373