SemaLookup.cpp revision 8d326ceb3e196f350b6a286f5ae3127ee10788e8
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 || ResultKind == NotFoundInCurrentInstantiation); 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.begin())) 328 ResultKind = FoundOverloaded; 329 else if (isa<UnresolvedUsingValueDecl>(*Decls.begin())) 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 if (!Record->isDefinition()) 464 return Found; 465 466 const UnresolvedSetImpl *Unresolved = Record->getConversionFunctions(); 467 for (UnresolvedSetImpl::iterator U = Unresolved->begin(), 468 UEnd = Unresolved->end(); U != UEnd; ++U) { 469 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U); 470 if (!ConvTemplate) 471 continue; 472 473 // When we're performing lookup for the purposes of redeclaration, just 474 // add the conversion function template. When we deduce template 475 // arguments for specializations, we'll end up unifying the return 476 // type of the new declaration with the type of the function template. 477 if (R.isForRedeclaration()) { 478 R.addDecl(ConvTemplate); 479 Found = true; 480 continue; 481 } 482 483 // C++ [temp.mem]p6: 484 // [...] For each such operator, if argument deduction succeeds 485 // (14.9.2.3), the resulting specialization is used as if found by 486 // name lookup. 487 // 488 // When referencing a conversion function for any purpose other than 489 // a redeclaration (such that we'll be building an expression with the 490 // result), perform template argument deduction and place the 491 // specialization into the result set. We do this to avoid forcing all 492 // callers to perform special deduction for conversion functions. 493 Sema::TemplateDeductionInfo Info(R.getSema().Context); 494 FunctionDecl *Specialization = 0; 495 496 const FunctionProtoType *ConvProto 497 = ConvTemplate->getTemplatedDecl()->getType() 498 ->getAs<FunctionProtoType>(); 499 assert(ConvProto && "Nonsensical conversion function template type"); 500 501 // Compute the type of the function that we would expect the conversion 502 // function to have, if it were to match the name given. 503 // FIXME: Calling convention! 504 QualType ExpectedType 505 = R.getSema().Context.getFunctionType( 506 R.getLookupName().getCXXNameType(), 507 0, 0, ConvProto->isVariadic(), 508 ConvProto->getTypeQuals(), 509 false, false, 0, 0, 510 ConvProto->getNoReturnAttr()); 511 512 // Perform template argument deduction against the type that we would 513 // expect the function to have. 514 if (R.getSema().DeduceTemplateArguments(ConvTemplate, 0, ExpectedType, 515 Specialization, Info) 516 == Sema::TDK_Success) { 517 R.addDecl(Specialization); 518 Found = true; 519 } 520 } 521 } 522 523 return Found; 524} 525 526// Performs C++ unqualified lookup into the given file context. 527static bool 528CppNamespaceLookup(LookupResult &R, ASTContext &Context, DeclContext *NS, 529 UnqualUsingDirectiveSet &UDirs) { 530 531 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!"); 532 533 // Perform direct name lookup into the LookupCtx. 534 bool Found = LookupDirect(R, NS); 535 536 // Perform direct name lookup into the namespaces nominated by the 537 // using directives whose common ancestor is this namespace. 538 UnqualUsingDirectiveSet::const_iterator UI, UEnd; 539 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(NS); 540 541 for (; UI != UEnd; ++UI) 542 if (LookupDirect(R, UI->getNominatedNamespace())) 543 Found = true; 544 545 R.resolveKind(); 546 547 return Found; 548} 549 550static bool isNamespaceOrTranslationUnitScope(Scope *S) { 551 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) 552 return Ctx->isFileContext(); 553 return false; 554} 555 556// Find the next outer declaration context corresponding to this scope. 557static DeclContext *findOuterContext(Scope *S) { 558 for (S = S->getParent(); S; S = S->getParent()) 559 if (S->getEntity()) 560 return static_cast<DeclContext *>(S->getEntity())->getPrimaryContext(); 561 562 return 0; 563} 564 565bool Sema::CppLookupName(LookupResult &R, Scope *S) { 566 assert(getLangOptions().CPlusPlus && "Can perform only C++ lookup"); 567 568 DeclarationName Name = R.getLookupName(); 569 570 Scope *Initial = S; 571 IdentifierResolver::iterator 572 I = IdResolver.begin(Name), 573 IEnd = IdResolver.end(); 574 575 // First we lookup local scope. 576 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir] 577 // ...During unqualified name lookup (3.4.1), the names appear as if 578 // they were declared in the nearest enclosing namespace which contains 579 // both the using-directive and the nominated namespace. 580 // [Note: in this context, "contains" means "contains directly or 581 // indirectly". 582 // 583 // For example: 584 // namespace A { int i; } 585 // void foo() { 586 // int i; 587 // { 588 // using namespace A; 589 // ++i; // finds local 'i', A::i appears at global scope 590 // } 591 // } 592 // 593 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) { 594 // Check whether the IdResolver has anything in this scope. 595 bool Found = false; 596 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) { 597 if (R.isAcceptableDecl(*I)) { 598 Found = true; 599 R.addDecl(*I); 600 } 601 } 602 if (Found) { 603 R.resolveKind(); 604 return true; 605 } 606 607 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) { 608 DeclContext *OuterCtx = findOuterContext(S); 609 for (; Ctx && Ctx->getPrimaryContext() != OuterCtx; 610 Ctx = Ctx->getLookupParent()) { 611 // We do not directly look into function or method contexts 612 // (since all local variables are found via the identifier 613 // changes) or in transparent contexts (since those entities 614 // will be found in the nearest enclosing non-transparent 615 // context). 616 if (Ctx->isFunctionOrMethod() || Ctx->isTransparentContext()) 617 continue; 618 619 // Perform qualified name lookup into this context. 620 // FIXME: In some cases, we know that every name that could be found by 621 // this qualified name lookup will also be on the identifier chain. For 622 // example, inside a class without any base classes, we never need to 623 // perform qualified lookup because all of the members are on top of the 624 // identifier chain. 625 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true)) 626 return true; 627 } 628 } 629 } 630 631 // Stop if we ran out of scopes. 632 // FIXME: This really, really shouldn't be happening. 633 if (!S) return false; 634 635 // Collect UsingDirectiveDecls in all scopes, and recursively all 636 // nominated namespaces by those using-directives. 637 // 638 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we 639 // don't build it for each lookup! 640 641 UnqualUsingDirectiveSet UDirs; 642 UDirs.visitScopeChain(Initial, S); 643 UDirs.done(); 644 645 // Lookup namespace scope, and global scope. 646 // Unqualified name lookup in C++ requires looking into scopes 647 // that aren't strictly lexical, and therefore we walk through the 648 // context as well as walking through the scopes. 649 650 for (; S; S = S->getParent()) { 651 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity()); 652 if (!Ctx || Ctx->isTransparentContext()) 653 continue; 654 655 assert(Ctx && Ctx->isFileContext() && 656 "We should have been looking only at file context here already."); 657 658 // Check whether the IdResolver has anything in this scope. 659 bool Found = false; 660 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) { 661 if (R.isAcceptableDecl(*I)) { 662 // We found something. Look for anything else in our scope 663 // with this same name and in an acceptable identifier 664 // namespace, so that we can construct an overload set if we 665 // need to. 666 Found = true; 667 R.addDecl(*I); 668 } 669 } 670 671 // Look into context considering using-directives. 672 if (CppNamespaceLookup(R, Context, Ctx, UDirs)) 673 Found = true; 674 675 if (Found) { 676 R.resolveKind(); 677 return true; 678 } 679 680 if (R.isForRedeclaration() && !Ctx->isTransparentContext()) 681 return false; 682 } 683 684 return !R.empty(); 685} 686 687/// @brief Perform unqualified name lookup starting from a given 688/// scope. 689/// 690/// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is 691/// used to find names within the current scope. For example, 'x' in 692/// @code 693/// int x; 694/// int f() { 695/// return x; // unqualified name look finds 'x' in the global scope 696/// } 697/// @endcode 698/// 699/// Different lookup criteria can find different names. For example, a 700/// particular scope can have both a struct and a function of the same 701/// name, and each can be found by certain lookup criteria. For more 702/// information about lookup criteria, see the documentation for the 703/// class LookupCriteria. 704/// 705/// @param S The scope from which unqualified name lookup will 706/// begin. If the lookup criteria permits, name lookup may also search 707/// in the parent scopes. 708/// 709/// @param Name The name of the entity that we are searching for. 710/// 711/// @param Loc If provided, the source location where we're performing 712/// name lookup. At present, this is only used to produce diagnostics when 713/// C library functions (like "malloc") are implicitly declared. 714/// 715/// @returns The result of name lookup, which includes zero or more 716/// declarations and possibly additional information used to diagnose 717/// ambiguities. 718bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) { 719 DeclarationName Name = R.getLookupName(); 720 if (!Name) return false; 721 722 LookupNameKind NameKind = R.getLookupKind(); 723 724 if (!getLangOptions().CPlusPlus) { 725 // Unqualified name lookup in C/Objective-C is purely lexical, so 726 // search in the declarations attached to the name. 727 728 if (NameKind == Sema::LookupRedeclarationWithLinkage) { 729 // Find the nearest non-transparent declaration scope. 730 while (!(S->getFlags() & Scope::DeclScope) || 731 (S->getEntity() && 732 static_cast<DeclContext *>(S->getEntity()) 733 ->isTransparentContext())) 734 S = S->getParent(); 735 } 736 737 unsigned IDNS = R.getIdentifierNamespace(); 738 739 // Scan up the scope chain looking for a decl that matches this 740 // identifier that is in the appropriate namespace. This search 741 // should not take long, as shadowing of names is uncommon, and 742 // deep shadowing is extremely uncommon. 743 bool LeftStartingScope = false; 744 745 for (IdentifierResolver::iterator I = IdResolver.begin(Name), 746 IEnd = IdResolver.end(); 747 I != IEnd; ++I) 748 if ((*I)->isInIdentifierNamespace(IDNS)) { 749 if (NameKind == LookupRedeclarationWithLinkage) { 750 // Determine whether this (or a previous) declaration is 751 // out-of-scope. 752 if (!LeftStartingScope && !S->isDeclScope(DeclPtrTy::make(*I))) 753 LeftStartingScope = true; 754 755 // If we found something outside of our starting scope that 756 // does not have linkage, skip it. 757 if (LeftStartingScope && !((*I)->hasLinkage())) 758 continue; 759 } 760 761 R.addDecl(*I); 762 763 if ((*I)->getAttr<OverloadableAttr>()) { 764 // If this declaration has the "overloadable" attribute, we 765 // might have a set of overloaded functions. 766 767 // Figure out what scope the identifier is in. 768 while (!(S->getFlags() & Scope::DeclScope) || 769 !S->isDeclScope(DeclPtrTy::make(*I))) 770 S = S->getParent(); 771 772 // Find the last declaration in this scope (with the same 773 // name, naturally). 774 IdentifierResolver::iterator LastI = I; 775 for (++LastI; LastI != IEnd; ++LastI) { 776 if (!S->isDeclScope(DeclPtrTy::make(*LastI))) 777 break; 778 R.addDecl(*LastI); 779 } 780 } 781 782 R.resolveKind(); 783 784 return true; 785 } 786 } else { 787 // Perform C++ unqualified name lookup. 788 if (CppLookupName(R, S)) 789 return true; 790 } 791 792 // If we didn't find a use of this identifier, and if the identifier 793 // corresponds to a compiler builtin, create the decl object for the builtin 794 // now, injecting it into translation unit scope, and return it. 795 if (NameKind == LookupOrdinaryName || 796 NameKind == LookupRedeclarationWithLinkage) { 797 IdentifierInfo *II = Name.getAsIdentifierInfo(); 798 if (II && AllowBuiltinCreation) { 799 // If this is a builtin on this (or all) targets, create the decl. 800 if (unsigned BuiltinID = II->getBuiltinID()) { 801 // In C++, we don't have any predefined library functions like 802 // 'malloc'. Instead, we'll just error. 803 if (getLangOptions().CPlusPlus && 804 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 805 return false; 806 807 NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 808 S, R.isForRedeclaration(), 809 R.getNameLoc()); 810 if (D) R.addDecl(D); 811 return (D != NULL); 812 } 813 } 814 } 815 return false; 816} 817 818/// @brief Perform qualified name lookup in the namespaces nominated by 819/// using directives by the given context. 820/// 821/// C++98 [namespace.qual]p2: 822/// Given X::m (where X is a user-declared namespace), or given ::m 823/// (where X is the global namespace), let S be the set of all 824/// declarations of m in X and in the transitive closure of all 825/// namespaces nominated by using-directives in X and its used 826/// namespaces, except that using-directives are ignored in any 827/// namespace, including X, directly containing one or more 828/// declarations of m. No namespace is searched more than once in 829/// the lookup of a name. If S is the empty set, the program is 830/// ill-formed. Otherwise, if S has exactly one member, or if the 831/// context of the reference is a using-declaration 832/// (namespace.udecl), S is the required set of declarations of 833/// m. Otherwise if the use of m is not one that allows a unique 834/// declaration to be chosen from S, the program is ill-formed. 835/// C++98 [namespace.qual]p5: 836/// During the lookup of a qualified namespace member name, if the 837/// lookup finds more than one declaration of the member, and if one 838/// declaration introduces a class name or enumeration name and the 839/// other declarations either introduce the same object, the same 840/// enumerator or a set of functions, the non-type name hides the 841/// class or enumeration name if and only if the declarations are 842/// from the same namespace; otherwise (the declarations are from 843/// different namespaces), the program is ill-formed. 844static bool LookupQualifiedNameInUsingDirectives(LookupResult &R, 845 DeclContext *StartDC) { 846 assert(StartDC->isFileContext() && "start context is not a file context"); 847 848 DeclContext::udir_iterator I = StartDC->using_directives_begin(); 849 DeclContext::udir_iterator E = StartDC->using_directives_end(); 850 851 if (I == E) return false; 852 853 // We have at least added all these contexts to the queue. 854 llvm::DenseSet<DeclContext*> Visited; 855 Visited.insert(StartDC); 856 857 // We have not yet looked into these namespaces, much less added 858 // their "using-children" to the queue. 859 llvm::SmallVector<NamespaceDecl*, 8> Queue; 860 861 // We have already looked into the initial namespace; seed the queue 862 // with its using-children. 863 for (; I != E; ++I) { 864 NamespaceDecl *ND = (*I)->getNominatedNamespace()->getOriginalNamespace(); 865 if (Visited.insert(ND).second) 866 Queue.push_back(ND); 867 } 868 869 // The easiest way to implement the restriction in [namespace.qual]p5 870 // is to check whether any of the individual results found a tag 871 // and, if so, to declare an ambiguity if the final result is not 872 // a tag. 873 bool FoundTag = false; 874 bool FoundNonTag = false; 875 876 LookupResult LocalR(LookupResult::Temporary, R); 877 878 bool Found = false; 879 while (!Queue.empty()) { 880 NamespaceDecl *ND = Queue.back(); 881 Queue.pop_back(); 882 883 // We go through some convolutions here to avoid copying results 884 // between LookupResults. 885 bool UseLocal = !R.empty(); 886 LookupResult &DirectR = UseLocal ? LocalR : R; 887 bool FoundDirect = LookupDirect(DirectR, ND); 888 889 if (FoundDirect) { 890 // First do any local hiding. 891 DirectR.resolveKind(); 892 893 // If the local result is a tag, remember that. 894 if (DirectR.isSingleTagDecl()) 895 FoundTag = true; 896 else 897 FoundNonTag = true; 898 899 // Append the local results to the total results if necessary. 900 if (UseLocal) { 901 R.addAllDecls(LocalR); 902 LocalR.clear(); 903 } 904 } 905 906 // If we find names in this namespace, ignore its using directives. 907 if (FoundDirect) { 908 Found = true; 909 continue; 910 } 911 912 for (llvm::tie(I,E) = ND->getUsingDirectives(); I != E; ++I) { 913 NamespaceDecl *Nom = (*I)->getNominatedNamespace(); 914 if (Visited.insert(Nom).second) 915 Queue.push_back(Nom); 916 } 917 } 918 919 if (Found) { 920 if (FoundTag && FoundNonTag) 921 R.setAmbiguousQualifiedTagHiding(); 922 else 923 R.resolveKind(); 924 } 925 926 return Found; 927} 928 929/// \brief Perform qualified name lookup into a given context. 930/// 931/// Qualified name lookup (C++ [basic.lookup.qual]) is used to find 932/// names when the context of those names is explicit specified, e.g., 933/// "std::vector" or "x->member", or as part of unqualified name lookup. 934/// 935/// Different lookup criteria can find different names. For example, a 936/// particular scope can have both a struct and a function of the same 937/// name, and each can be found by certain lookup criteria. For more 938/// information about lookup criteria, see the documentation for the 939/// class LookupCriteria. 940/// 941/// \param R captures both the lookup criteria and any lookup results found. 942/// 943/// \param LookupCtx The context in which qualified name lookup will 944/// search. If the lookup criteria permits, name lookup may also search 945/// in the parent contexts or (for C++ classes) base classes. 946/// 947/// \param InUnqualifiedLookup true if this is qualified name lookup that 948/// occurs as part of unqualified name lookup. 949/// 950/// \returns true if lookup succeeded, false if it failed. 951bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 952 bool InUnqualifiedLookup) { 953 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context"); 954 955 if (!R.getLookupName()) 956 return false; 957 958 // Make sure that the declaration context is complete. 959 assert((!isa<TagDecl>(LookupCtx) || 960 LookupCtx->isDependentContext() || 961 cast<TagDecl>(LookupCtx)->isDefinition() || 962 Context.getTypeDeclType(cast<TagDecl>(LookupCtx))->getAs<TagType>() 963 ->isBeingDefined()) && 964 "Declaration context must already be complete!"); 965 966 // Perform qualified name lookup into the LookupCtx. 967 if (LookupDirect(R, LookupCtx)) { 968 R.resolveKind(); 969 return true; 970 } 971 972 // Don't descend into implied contexts for redeclarations. 973 // C++98 [namespace.qual]p6: 974 // In a declaration for a namespace member in which the 975 // declarator-id is a qualified-id, given that the qualified-id 976 // for the namespace member has the form 977 // nested-name-specifier unqualified-id 978 // the unqualified-id shall name a member of the namespace 979 // designated by the nested-name-specifier. 980 // See also [class.mfct]p5 and [class.static.data]p2. 981 if (R.isForRedeclaration()) 982 return false; 983 984 // If this is a namespace, look it up in the implied namespaces. 985 if (LookupCtx->isFileContext()) 986 return LookupQualifiedNameInUsingDirectives(R, LookupCtx); 987 988 // If this isn't a C++ class, we aren't allowed to look into base 989 // classes, we're done. 990 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx); 991 if (!LookupRec) 992 return false; 993 994 // If we're performing qualified name lookup into a dependent class, 995 // then we are actually looking into a current instantiation. If we have any 996 // dependent base classes, then we either have to delay lookup until 997 // template instantiation time (at which point all bases will be available) 998 // or we have to fail. 999 if (!InUnqualifiedLookup && LookupRec->isDependentContext() && 1000 LookupRec->hasAnyDependentBases()) { 1001 R.setNotFoundInCurrentInstantiation(); 1002 return false; 1003 } 1004 1005 // Perform lookup into our base classes. 1006 CXXBasePaths Paths; 1007 Paths.setOrigin(LookupRec); 1008 1009 // Look for this member in our base classes 1010 CXXRecordDecl::BaseMatchesCallback *BaseCallback = 0; 1011 switch (R.getLookupKind()) { 1012 case LookupOrdinaryName: 1013 case LookupMemberName: 1014 case LookupRedeclarationWithLinkage: 1015 BaseCallback = &CXXRecordDecl::FindOrdinaryMember; 1016 break; 1017 1018 case LookupTagName: 1019 BaseCallback = &CXXRecordDecl::FindTagMember; 1020 break; 1021 1022 case LookupUsingDeclName: 1023 // This lookup is for redeclarations only. 1024 1025 case LookupOperatorName: 1026 case LookupNamespaceName: 1027 case LookupObjCProtocolName: 1028 case LookupObjCImplementationName: 1029 // These lookups will never find a member in a C++ class (or base class). 1030 return false; 1031 1032 case LookupNestedNameSpecifierName: 1033 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember; 1034 break; 1035 } 1036 1037 if (!LookupRec->lookupInBases(BaseCallback, 1038 R.getLookupName().getAsOpaquePtr(), Paths)) 1039 return false; 1040 1041 // C++ [class.member.lookup]p2: 1042 // [...] If the resulting set of declarations are not all from 1043 // sub-objects of the same type, or the set has a nonstatic member 1044 // and includes members from distinct sub-objects, there is an 1045 // ambiguity and the program is ill-formed. Otherwise that set is 1046 // the result of the lookup. 1047 // FIXME: support using declarations! 1048 QualType SubobjectType; 1049 int SubobjectNumber = 0; 1050 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); 1051 Path != PathEnd; ++Path) { 1052 const CXXBasePathElement &PathElement = Path->back(); 1053 1054 // Determine whether we're looking at a distinct sub-object or not. 1055 if (SubobjectType.isNull()) { 1056 // This is the first subobject we've looked at. Record its type. 1057 SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); 1058 SubobjectNumber = PathElement.SubobjectNumber; 1059 } else if (SubobjectType 1060 != Context.getCanonicalType(PathElement.Base->getType())) { 1061 // We found members of the given name in two subobjects of 1062 // different types. This lookup is ambiguous. 1063 R.setAmbiguousBaseSubobjectTypes(Paths); 1064 return true; 1065 } else if (SubobjectNumber != PathElement.SubobjectNumber) { 1066 // We have a different subobject of the same type. 1067 1068 // C++ [class.member.lookup]p5: 1069 // A static member, a nested type or an enumerator defined in 1070 // a base class T can unambiguously be found even if an object 1071 // has more than one base class subobject of type T. 1072 Decl *FirstDecl = *Path->Decls.first; 1073 if (isa<VarDecl>(FirstDecl) || 1074 isa<TypeDecl>(FirstDecl) || 1075 isa<EnumConstantDecl>(FirstDecl)) 1076 continue; 1077 1078 if (isa<CXXMethodDecl>(FirstDecl)) { 1079 // Determine whether all of the methods are static. 1080 bool AllMethodsAreStatic = true; 1081 for (DeclContext::lookup_iterator Func = Path->Decls.first; 1082 Func != Path->Decls.second; ++Func) { 1083 if (!isa<CXXMethodDecl>(*Func)) { 1084 assert(isa<TagDecl>(*Func) && "Non-function must be a tag decl"); 1085 break; 1086 } 1087 1088 if (!cast<CXXMethodDecl>(*Func)->isStatic()) { 1089 AllMethodsAreStatic = false; 1090 break; 1091 } 1092 } 1093 1094 if (AllMethodsAreStatic) 1095 continue; 1096 } 1097 1098 // We have found a nonstatic member name in multiple, distinct 1099 // subobjects. Name lookup is ambiguous. 1100 R.setAmbiguousBaseSubobjects(Paths); 1101 return true; 1102 } 1103 } 1104 1105 // Lookup in a base class succeeded; return these results. 1106 1107 DeclContext::lookup_iterator I, E; 1108 for (llvm::tie(I,E) = Paths.front().Decls; I != E; ++I) 1109 R.addDecl(*I); 1110 R.resolveKind(); 1111 return true; 1112} 1113 1114/// @brief Performs name lookup for a name that was parsed in the 1115/// source code, and may contain a C++ scope specifier. 1116/// 1117/// This routine is a convenience routine meant to be called from 1118/// contexts that receive a name and an optional C++ scope specifier 1119/// (e.g., "N::M::x"). It will then perform either qualified or 1120/// unqualified name lookup (with LookupQualifiedName or LookupName, 1121/// respectively) on the given name and return those results. 1122/// 1123/// @param S The scope from which unqualified name lookup will 1124/// begin. 1125/// 1126/// @param SS An optional C++ scope-specifier, e.g., "::N::M". 1127/// 1128/// @param Name The name of the entity that name lookup will 1129/// search for. 1130/// 1131/// @param Loc If provided, the source location where we're performing 1132/// name lookup. At present, this is only used to produce diagnostics when 1133/// C library functions (like "malloc") are implicitly declared. 1134/// 1135/// @param EnteringContext Indicates whether we are going to enter the 1136/// context of the scope-specifier SS (if present). 1137/// 1138/// @returns True if any decls were found (but possibly ambiguous) 1139bool Sema::LookupParsedName(LookupResult &R, Scope *S, const CXXScopeSpec *SS, 1140 bool AllowBuiltinCreation, bool EnteringContext) { 1141 if (SS && SS->isInvalid()) { 1142 // When the scope specifier is invalid, don't even look for 1143 // anything. 1144 return false; 1145 } 1146 1147 if (SS && SS->isSet()) { 1148 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { 1149 // We have resolved the scope specifier to a particular declaration 1150 // contex, and will perform name lookup in that context. 1151 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS)) 1152 return false; 1153 1154 R.setContextRange(SS->getRange()); 1155 1156 return LookupQualifiedName(R, DC); 1157 } 1158 1159 // We could not resolve the scope specified to a specific declaration 1160 // context, which means that SS refers to an unknown specialization. 1161 // Name lookup can't find anything in this case. 1162 return false; 1163 } 1164 1165 // Perform unqualified name lookup starting in the given scope. 1166 return LookupName(R, S, AllowBuiltinCreation); 1167} 1168 1169 1170/// @brief Produce a diagnostic describing the ambiguity that resulted 1171/// from name lookup. 1172/// 1173/// @param Result The ambiguous name lookup result. 1174/// 1175/// @param Name The name of the entity that name lookup was 1176/// searching for. 1177/// 1178/// @param NameLoc The location of the name within the source code. 1179/// 1180/// @param LookupRange A source range that provides more 1181/// source-location information concerning the lookup itself. For 1182/// example, this range might highlight a nested-name-specifier that 1183/// precedes the name. 1184/// 1185/// @returns true 1186bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result) { 1187 assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); 1188 1189 DeclarationName Name = Result.getLookupName(); 1190 SourceLocation NameLoc = Result.getNameLoc(); 1191 SourceRange LookupRange = Result.getContextRange(); 1192 1193 switch (Result.getAmbiguityKind()) { 1194 case LookupResult::AmbiguousBaseSubobjects: { 1195 CXXBasePaths *Paths = Result.getBasePaths(); 1196 QualType SubobjectType = Paths->front().back().Base->getType(); 1197 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) 1198 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) 1199 << LookupRange; 1200 1201 DeclContext::lookup_iterator Found = Paths->front().Decls.first; 1202 while (isa<CXXMethodDecl>(*Found) && 1203 cast<CXXMethodDecl>(*Found)->isStatic()) 1204 ++Found; 1205 1206 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); 1207 1208 return true; 1209 } 1210 1211 case LookupResult::AmbiguousBaseSubobjectTypes: { 1212 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) 1213 << Name << LookupRange; 1214 1215 CXXBasePaths *Paths = Result.getBasePaths(); 1216 std::set<Decl *> DeclsPrinted; 1217 for (CXXBasePaths::paths_iterator Path = Paths->begin(), 1218 PathEnd = Paths->end(); 1219 Path != PathEnd; ++Path) { 1220 Decl *D = *Path->Decls.first; 1221 if (DeclsPrinted.insert(D).second) 1222 Diag(D->getLocation(), diag::note_ambiguous_member_found); 1223 } 1224 1225 return true; 1226 } 1227 1228 case LookupResult::AmbiguousTagHiding: { 1229 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange; 1230 1231 llvm::SmallPtrSet<NamedDecl*,8> TagDecls; 1232 1233 LookupResult::iterator DI, DE = Result.end(); 1234 for (DI = Result.begin(); DI != DE; ++DI) 1235 if (TagDecl *TD = dyn_cast<TagDecl>(*DI)) { 1236 TagDecls.insert(TD); 1237 Diag(TD->getLocation(), diag::note_hidden_tag); 1238 } 1239 1240 for (DI = Result.begin(); DI != DE; ++DI) 1241 if (!isa<TagDecl>(*DI)) 1242 Diag((*DI)->getLocation(), diag::note_hiding_object); 1243 1244 // For recovery purposes, go ahead and implement the hiding. 1245 LookupResult::Filter F = Result.makeFilter(); 1246 while (F.hasNext()) { 1247 if (TagDecls.count(F.next())) 1248 F.erase(); 1249 } 1250 F.done(); 1251 1252 return true; 1253 } 1254 1255 case LookupResult::AmbiguousReference: { 1256 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; 1257 1258 LookupResult::iterator DI = Result.begin(), DE = Result.end(); 1259 for (; DI != DE; ++DI) 1260 Diag((*DI)->getLocation(), diag::note_ambiguous_candidate) << *DI; 1261 1262 return true; 1263 } 1264 } 1265 1266 llvm_unreachable("unknown ambiguity kind"); 1267 return true; 1268} 1269 1270static void 1271addAssociatedClassesAndNamespaces(QualType T, 1272 ASTContext &Context, 1273 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1274 Sema::AssociatedClassSet &AssociatedClasses); 1275 1276static void CollectNamespace(Sema::AssociatedNamespaceSet &Namespaces, 1277 DeclContext *Ctx) { 1278 if (Ctx->isFileContext()) 1279 Namespaces.insert(Ctx); 1280} 1281 1282// \brief Add the associated classes and namespaces for argument-dependent 1283// lookup that involves a template argument (C++ [basic.lookup.koenig]p2). 1284static void 1285addAssociatedClassesAndNamespaces(const TemplateArgument &Arg, 1286 ASTContext &Context, 1287 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1288 Sema::AssociatedClassSet &AssociatedClasses) { 1289 // C++ [basic.lookup.koenig]p2, last bullet: 1290 // -- [...] ; 1291 switch (Arg.getKind()) { 1292 case TemplateArgument::Null: 1293 break; 1294 1295 case TemplateArgument::Type: 1296 // [...] the namespaces and classes associated with the types of the 1297 // template arguments provided for template type parameters (excluding 1298 // template template parameters) 1299 addAssociatedClassesAndNamespaces(Arg.getAsType(), Context, 1300 AssociatedNamespaces, 1301 AssociatedClasses); 1302 break; 1303 1304 case TemplateArgument::Template: { 1305 // [...] the namespaces in which any template template arguments are 1306 // defined; and the classes in which any member templates used as 1307 // template template arguments are defined. 1308 TemplateName Template = Arg.getAsTemplate(); 1309 if (ClassTemplateDecl *ClassTemplate 1310 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) { 1311 DeclContext *Ctx = ClassTemplate->getDeclContext(); 1312 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1313 AssociatedClasses.insert(EnclosingClass); 1314 // Add the associated namespace for this class. 1315 while (Ctx->isRecord()) 1316 Ctx = Ctx->getParent(); 1317 CollectNamespace(AssociatedNamespaces, Ctx); 1318 } 1319 break; 1320 } 1321 1322 case TemplateArgument::Declaration: 1323 case TemplateArgument::Integral: 1324 case TemplateArgument::Expression: 1325 // [Note: non-type template arguments do not contribute to the set of 1326 // associated namespaces. ] 1327 break; 1328 1329 case TemplateArgument::Pack: 1330 for (TemplateArgument::pack_iterator P = Arg.pack_begin(), 1331 PEnd = Arg.pack_end(); 1332 P != PEnd; ++P) 1333 addAssociatedClassesAndNamespaces(*P, Context, 1334 AssociatedNamespaces, 1335 AssociatedClasses); 1336 break; 1337 } 1338} 1339 1340// \brief Add the associated classes and namespaces for 1341// argument-dependent lookup with an argument of class type 1342// (C++ [basic.lookup.koenig]p2). 1343static void 1344addAssociatedClassesAndNamespaces(CXXRecordDecl *Class, 1345 ASTContext &Context, 1346 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1347 Sema::AssociatedClassSet &AssociatedClasses) { 1348 // C++ [basic.lookup.koenig]p2: 1349 // [...] 1350 // -- If T is a class type (including unions), its associated 1351 // classes are: the class itself; the class of which it is a 1352 // member, if any; and its direct and indirect base 1353 // classes. Its associated namespaces are the namespaces in 1354 // which its associated classes are defined. 1355 1356 // Add the class of which it is a member, if any. 1357 DeclContext *Ctx = Class->getDeclContext(); 1358 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1359 AssociatedClasses.insert(EnclosingClass); 1360 // Add the associated namespace for this class. 1361 while (Ctx->isRecord()) 1362 Ctx = Ctx->getParent(); 1363 CollectNamespace(AssociatedNamespaces, Ctx); 1364 1365 // Add the class itself. If we've already seen this class, we don't 1366 // need to visit base classes. 1367 if (!AssociatedClasses.insert(Class)) 1368 return; 1369 1370 // -- If T is a template-id, its associated namespaces and classes are 1371 // the namespace in which the template is defined; for member 1372 // templates, the member template’s class; the namespaces and classes 1373 // associated with the types of the template arguments provided for 1374 // template type parameters (excluding template template parameters); the 1375 // namespaces in which any template template arguments are defined; and 1376 // the classes in which any member templates used as template template 1377 // arguments are defined. [Note: non-type template arguments do not 1378 // contribute to the set of associated namespaces. ] 1379 if (ClassTemplateSpecializationDecl *Spec 1380 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) { 1381 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); 1382 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1383 AssociatedClasses.insert(EnclosingClass); 1384 // Add the associated namespace for this class. 1385 while (Ctx->isRecord()) 1386 Ctx = Ctx->getParent(); 1387 CollectNamespace(AssociatedNamespaces, Ctx); 1388 1389 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); 1390 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 1391 addAssociatedClassesAndNamespaces(TemplateArgs[I], Context, 1392 AssociatedNamespaces, 1393 AssociatedClasses); 1394 } 1395 1396 // Add direct and indirect base classes along with their associated 1397 // namespaces. 1398 llvm::SmallVector<CXXRecordDecl *, 32> Bases; 1399 Bases.push_back(Class); 1400 while (!Bases.empty()) { 1401 // Pop this class off the stack. 1402 Class = Bases.back(); 1403 Bases.pop_back(); 1404 1405 // Visit the base classes. 1406 for (CXXRecordDecl::base_class_iterator Base = Class->bases_begin(), 1407 BaseEnd = Class->bases_end(); 1408 Base != BaseEnd; ++Base) { 1409 const RecordType *BaseType = Base->getType()->getAs<RecordType>(); 1410 // In dependent contexts, we do ADL twice, and the first time around, 1411 // the base type might be a dependent TemplateSpecializationType, or a 1412 // TemplateTypeParmType. If that happens, simply ignore it. 1413 // FIXME: If we want to support export, we probably need to add the 1414 // namespace of the template in a TemplateSpecializationType, or even 1415 // the classes and namespaces of known non-dependent arguments. 1416 if (!BaseType) 1417 continue; 1418 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 1419 if (AssociatedClasses.insert(BaseDecl)) { 1420 // Find the associated namespace for this base class. 1421 DeclContext *BaseCtx = BaseDecl->getDeclContext(); 1422 while (BaseCtx->isRecord()) 1423 BaseCtx = BaseCtx->getParent(); 1424 CollectNamespace(AssociatedNamespaces, BaseCtx); 1425 1426 // Make sure we visit the bases of this base class. 1427 if (BaseDecl->bases_begin() != BaseDecl->bases_end()) 1428 Bases.push_back(BaseDecl); 1429 } 1430 } 1431 } 1432} 1433 1434// \brief Add the associated classes and namespaces for 1435// argument-dependent lookup with an argument of type T 1436// (C++ [basic.lookup.koenig]p2). 1437static void 1438addAssociatedClassesAndNamespaces(QualType T, 1439 ASTContext &Context, 1440 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1441 Sema::AssociatedClassSet &AssociatedClasses) { 1442 // C++ [basic.lookup.koenig]p2: 1443 // 1444 // For each argument type T in the function call, there is a set 1445 // of zero or more associated namespaces and a set of zero or more 1446 // associated classes to be considered. The sets of namespaces and 1447 // classes is determined entirely by the types of the function 1448 // arguments (and the namespace of any template template 1449 // argument). Typedef names and using-declarations used to specify 1450 // the types do not contribute to this set. The sets of namespaces 1451 // and classes are determined in the following way: 1452 T = Context.getCanonicalType(T).getUnqualifiedType(); 1453 1454 // -- If T is a pointer to U or an array of U, its associated 1455 // namespaces and classes are those associated with U. 1456 // 1457 // We handle this by unwrapping pointer and array types immediately, 1458 // to avoid unnecessary recursion. 1459 while (true) { 1460 if (const PointerType *Ptr = T->getAs<PointerType>()) 1461 T = Ptr->getPointeeType(); 1462 else if (const ArrayType *Ptr = Context.getAsArrayType(T)) 1463 T = Ptr->getElementType(); 1464 else 1465 break; 1466 } 1467 1468 // -- If T is a fundamental type, its associated sets of 1469 // namespaces and classes are both empty. 1470 if (T->getAs<BuiltinType>()) 1471 return; 1472 1473 // -- If T is a class type (including unions), its associated 1474 // classes are: the class itself; the class of which it is a 1475 // member, if any; and its direct and indirect base 1476 // classes. Its associated namespaces are the namespaces in 1477 // which its associated classes are defined. 1478 if (const RecordType *ClassType = T->getAs<RecordType>()) 1479 if (CXXRecordDecl *ClassDecl 1480 = dyn_cast<CXXRecordDecl>(ClassType->getDecl())) { 1481 addAssociatedClassesAndNamespaces(ClassDecl, Context, 1482 AssociatedNamespaces, 1483 AssociatedClasses); 1484 return; 1485 } 1486 1487 // -- If T is an enumeration type, its associated namespace is 1488 // the namespace in which it is defined. If it is class 1489 // member, its associated class is the member’s class; else 1490 // it has no associated class. 1491 if (const EnumType *EnumT = T->getAs<EnumType>()) { 1492 EnumDecl *Enum = EnumT->getDecl(); 1493 1494 DeclContext *Ctx = Enum->getDeclContext(); 1495 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1496 AssociatedClasses.insert(EnclosingClass); 1497 1498 // Add the associated namespace for this class. 1499 while (Ctx->isRecord()) 1500 Ctx = Ctx->getParent(); 1501 CollectNamespace(AssociatedNamespaces, Ctx); 1502 1503 return; 1504 } 1505 1506 // -- If T is a function type, its associated namespaces and 1507 // classes are those associated with the function parameter 1508 // types and those associated with the return type. 1509 if (const FunctionType *FnType = T->getAs<FunctionType>()) { 1510 // Return type 1511 addAssociatedClassesAndNamespaces(FnType->getResultType(), 1512 Context, 1513 AssociatedNamespaces, AssociatedClasses); 1514 1515 const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FnType); 1516 if (!Proto) 1517 return; 1518 1519 // Argument types 1520 for (FunctionProtoType::arg_type_iterator Arg = Proto->arg_type_begin(), 1521 ArgEnd = Proto->arg_type_end(); 1522 Arg != ArgEnd; ++Arg) 1523 addAssociatedClassesAndNamespaces(*Arg, Context, 1524 AssociatedNamespaces, AssociatedClasses); 1525 1526 return; 1527 } 1528 1529 // -- If T is a pointer to a member function of a class X, its 1530 // associated namespaces and classes are those associated 1531 // with the function parameter types and return type, 1532 // together with those associated with X. 1533 // 1534 // -- If T is a pointer to a data member of class X, its 1535 // associated namespaces and classes are those associated 1536 // with the member type together with those associated with 1537 // X. 1538 if (const MemberPointerType *MemberPtr = T->getAs<MemberPointerType>()) { 1539 // Handle the type that the pointer to member points to. 1540 addAssociatedClassesAndNamespaces(MemberPtr->getPointeeType(), 1541 Context, 1542 AssociatedNamespaces, 1543 AssociatedClasses); 1544 1545 // Handle the class type into which this points. 1546 if (const RecordType *Class = MemberPtr->getClass()->getAs<RecordType>()) 1547 addAssociatedClassesAndNamespaces(cast<CXXRecordDecl>(Class->getDecl()), 1548 Context, 1549 AssociatedNamespaces, 1550 AssociatedClasses); 1551 1552 return; 1553 } 1554 1555 // FIXME: What about block pointers? 1556 // FIXME: What about Objective-C message sends? 1557} 1558 1559/// \brief Find the associated classes and namespaces for 1560/// argument-dependent lookup for a call with the given set of 1561/// arguments. 1562/// 1563/// This routine computes the sets of associated classes and associated 1564/// namespaces searched by argument-dependent lookup 1565/// (C++ [basic.lookup.argdep]) for a given set of arguments. 1566void 1567Sema::FindAssociatedClassesAndNamespaces(Expr **Args, unsigned NumArgs, 1568 AssociatedNamespaceSet &AssociatedNamespaces, 1569 AssociatedClassSet &AssociatedClasses) { 1570 AssociatedNamespaces.clear(); 1571 AssociatedClasses.clear(); 1572 1573 // C++ [basic.lookup.koenig]p2: 1574 // For each argument type T in the function call, there is a set 1575 // of zero or more associated namespaces and a set of zero or more 1576 // associated classes to be considered. The sets of namespaces and 1577 // classes is determined entirely by the types of the function 1578 // arguments (and the namespace of any template template 1579 // argument). 1580 for (unsigned ArgIdx = 0; ArgIdx != NumArgs; ++ArgIdx) { 1581 Expr *Arg = Args[ArgIdx]; 1582 1583 if (Arg->getType() != Context.OverloadTy) { 1584 addAssociatedClassesAndNamespaces(Arg->getType(), Context, 1585 AssociatedNamespaces, 1586 AssociatedClasses); 1587 continue; 1588 } 1589 1590 // [...] In addition, if the argument is the name or address of a 1591 // set of overloaded functions and/or function templates, its 1592 // associated classes and namespaces are the union of those 1593 // associated with each of the members of the set: the namespace 1594 // in which the function or function template is defined and the 1595 // classes and namespaces associated with its (non-dependent) 1596 // parameter types and return type. 1597 Arg = Arg->IgnoreParens(); 1598 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg)) 1599 if (unaryOp->getOpcode() == UnaryOperator::AddrOf) 1600 Arg = unaryOp->getSubExpr(); 1601 1602 // TODO: avoid the copies. This should be easy when the cases 1603 // share a storage implementation. 1604 llvm::SmallVector<NamedDecl*, 8> Functions; 1605 1606 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg)) 1607 Functions.append(ULE->decls_begin(), ULE->decls_end()); 1608 else 1609 continue; 1610 1611 for (llvm::SmallVectorImpl<NamedDecl*>::iterator I = Functions.begin(), 1612 E = Functions.end(); I != E; ++I) { 1613 // Look through any using declarations to find the underlying function. 1614 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 1615 1616 FunctionDecl *FDecl = dyn_cast<FunctionDecl>(Fn); 1617 if (!FDecl) 1618 FDecl = cast<FunctionTemplateDecl>(Fn)->getTemplatedDecl(); 1619 1620 // Add the classes and namespaces associated with the parameter 1621 // types and return type of this function. 1622 addAssociatedClassesAndNamespaces(FDecl->getType(), Context, 1623 AssociatedNamespaces, 1624 AssociatedClasses); 1625 } 1626 } 1627} 1628 1629/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is 1630/// an acceptable non-member overloaded operator for a call whose 1631/// arguments have types T1 (and, if non-empty, T2). This routine 1632/// implements the check in C++ [over.match.oper]p3b2 concerning 1633/// enumeration types. 1634static bool 1635IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn, 1636 QualType T1, QualType T2, 1637 ASTContext &Context) { 1638 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType())) 1639 return true; 1640 1641 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType())) 1642 return true; 1643 1644 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>(); 1645 if (Proto->getNumArgs() < 1) 1646 return false; 1647 1648 if (T1->isEnumeralType()) { 1649 QualType ArgType = Proto->getArgType(0).getNonReferenceType(); 1650 if (Context.hasSameUnqualifiedType(T1, ArgType)) 1651 return true; 1652 } 1653 1654 if (Proto->getNumArgs() < 2) 1655 return false; 1656 1657 if (!T2.isNull() && T2->isEnumeralType()) { 1658 QualType ArgType = Proto->getArgType(1).getNonReferenceType(); 1659 if (Context.hasSameUnqualifiedType(T2, ArgType)) 1660 return true; 1661 } 1662 1663 return false; 1664} 1665 1666NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name, 1667 LookupNameKind NameKind, 1668 RedeclarationKind Redecl) { 1669 LookupResult R(*this, Name, SourceLocation(), NameKind, Redecl); 1670 LookupName(R, S); 1671 return R.getAsSingle<NamedDecl>(); 1672} 1673 1674/// \brief Find the protocol with the given name, if any. 1675ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II) { 1676 Decl *D = LookupSingleName(TUScope, II, LookupObjCProtocolName); 1677 return cast_or_null<ObjCProtocolDecl>(D); 1678} 1679 1680void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, 1681 QualType T1, QualType T2, 1682 FunctionSet &Functions) { 1683 // C++ [over.match.oper]p3: 1684 // -- The set of non-member candidates is the result of the 1685 // unqualified lookup of operator@ in the context of the 1686 // expression according to the usual rules for name lookup in 1687 // unqualified function calls (3.4.2) except that all member 1688 // functions are ignored. However, if no operand has a class 1689 // type, only those non-member functions in the lookup set 1690 // that have a first parameter of type T1 or "reference to 1691 // (possibly cv-qualified) T1", when T1 is an enumeration 1692 // type, or (if there is a right operand) a second parameter 1693 // of type T2 or "reference to (possibly cv-qualified) T2", 1694 // when T2 is an enumeration type, are candidate functions. 1695 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 1696 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName); 1697 LookupName(Operators, S); 1698 1699 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); 1700 1701 if (Operators.empty()) 1702 return; 1703 1704 for (LookupResult::iterator Op = Operators.begin(), OpEnd = Operators.end(); 1705 Op != OpEnd; ++Op) { 1706 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Op)) { 1707 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context)) 1708 Functions.insert(FD); // FIXME: canonical FD 1709 } else if (FunctionTemplateDecl *FunTmpl 1710 = dyn_cast<FunctionTemplateDecl>(*Op)) { 1711 // FIXME: friend operators? 1712 // FIXME: do we need to check IsAcceptableNonMemberOperatorCandidate, 1713 // later? 1714 if (!FunTmpl->getDeclContext()->isRecord()) 1715 Functions.insert(FunTmpl); 1716 } 1717 } 1718} 1719 1720static void CollectFunctionDecl(Sema::FunctionSet &Functions, 1721 Decl *D) { 1722 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(D)) 1723 Functions.insert(Func); 1724 else if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D)) 1725 Functions.insert(FunTmpl); 1726} 1727 1728void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator, 1729 Expr **Args, unsigned NumArgs, 1730 FunctionSet &Functions) { 1731 // Find all of the associated namespaces and classes based on the 1732 // arguments we have. 1733 AssociatedNamespaceSet AssociatedNamespaces; 1734 AssociatedClassSet AssociatedClasses; 1735 FindAssociatedClassesAndNamespaces(Args, NumArgs, 1736 AssociatedNamespaces, 1737 AssociatedClasses); 1738 1739 QualType T1, T2; 1740 if (Operator) { 1741 T1 = Args[0]->getType(); 1742 if (NumArgs >= 2) 1743 T2 = Args[1]->getType(); 1744 } 1745 1746 // C++ [basic.lookup.argdep]p3: 1747 // Let X be the lookup set produced by unqualified lookup (3.4.1) 1748 // and let Y be the lookup set produced by argument dependent 1749 // lookup (defined as follows). If X contains [...] then Y is 1750 // empty. Otherwise Y is the set of declarations found in the 1751 // namespaces associated with the argument types as described 1752 // below. The set of declarations found by the lookup of the name 1753 // is the union of X and Y. 1754 // 1755 // Here, we compute Y and add its members to the overloaded 1756 // candidate set. 1757 for (AssociatedNamespaceSet::iterator NS = AssociatedNamespaces.begin(), 1758 NSEnd = AssociatedNamespaces.end(); 1759 NS != NSEnd; ++NS) { 1760 // When considering an associated namespace, the lookup is the 1761 // same as the lookup performed when the associated namespace is 1762 // used as a qualifier (3.4.3.2) except that: 1763 // 1764 // -- Any using-directives in the associated namespace are 1765 // ignored. 1766 // 1767 // -- Any namespace-scope friend functions declared in 1768 // associated classes are visible within their respective 1769 // namespaces even if they are not visible during an ordinary 1770 // lookup (11.4). 1771 DeclContext::lookup_iterator I, E; 1772 for (llvm::tie(I, E) = (*NS)->lookup(Name); I != E; ++I) { 1773 Decl *D = *I; 1774 // If the only declaration here is an ordinary friend, consider 1775 // it only if it was declared in an associated classes. 1776 if (D->getIdentifierNamespace() == Decl::IDNS_OrdinaryFriend) { 1777 DeclContext *LexDC = D->getLexicalDeclContext(); 1778 if (!AssociatedClasses.count(cast<CXXRecordDecl>(LexDC))) 1779 continue; 1780 } 1781 1782 FunctionDecl *Fn; 1783 if (!Operator || !(Fn = dyn_cast<FunctionDecl>(D)) || 1784 IsAcceptableNonMemberOperatorCandidate(Fn, T1, T2, Context)) 1785 CollectFunctionDecl(Functions, D); 1786 } 1787 } 1788} 1789 1790//---------------------------------------------------------------------------- 1791// Search for all visible declarations. 1792//---------------------------------------------------------------------------- 1793VisibleDeclConsumer::~VisibleDeclConsumer() { } 1794 1795namespace { 1796 1797class ShadowContextRAII; 1798 1799class VisibleDeclsRecord { 1800public: 1801 /// \brief An entry in the shadow map, which is optimized to store a 1802 /// single declaration (the common case) but can also store a list 1803 /// of declarations. 1804 class ShadowMapEntry { 1805 typedef llvm::SmallVector<NamedDecl *, 4> DeclVector; 1806 1807 /// \brief Contains either the solitary NamedDecl * or a vector 1808 /// of declarations. 1809 llvm::PointerUnion<NamedDecl *, DeclVector*> DeclOrVector; 1810 1811 public: 1812 ShadowMapEntry() : DeclOrVector() { } 1813 1814 void Add(NamedDecl *ND); 1815 void Destroy(); 1816 1817 // Iteration. 1818 typedef NamedDecl **iterator; 1819 iterator begin(); 1820 iterator end(); 1821 }; 1822 1823private: 1824 /// \brief A mapping from declaration names to the declarations that have 1825 /// this name within a particular scope. 1826 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap; 1827 1828 /// \brief A list of shadow maps, which is used to model name hiding. 1829 std::list<ShadowMap> ShadowMaps; 1830 1831 /// \brief The declaration contexts we have already visited. 1832 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts; 1833 1834 friend class ShadowContextRAII; 1835 1836public: 1837 /// \brief Determine whether we have already visited this context 1838 /// (and, if not, note that we are going to visit that context now). 1839 bool visitedContext(DeclContext *Ctx) { 1840 return !VisitedContexts.insert(Ctx); 1841 } 1842 1843 /// \brief Determine whether the given declaration is hidden in the 1844 /// current scope. 1845 /// 1846 /// \returns the declaration that hides the given declaration, or 1847 /// NULL if no such declaration exists. 1848 NamedDecl *checkHidden(NamedDecl *ND); 1849 1850 /// \brief Add a declaration to the current shadow map. 1851 void add(NamedDecl *ND) { ShadowMaps.back()[ND->getDeclName()].Add(ND); } 1852}; 1853 1854/// \brief RAII object that records when we've entered a shadow context. 1855class ShadowContextRAII { 1856 VisibleDeclsRecord &Visible; 1857 1858 typedef VisibleDeclsRecord::ShadowMap ShadowMap; 1859 1860public: 1861 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) { 1862 Visible.ShadowMaps.push_back(ShadowMap()); 1863 } 1864 1865 ~ShadowContextRAII() { 1866 for (ShadowMap::iterator E = Visible.ShadowMaps.back().begin(), 1867 EEnd = Visible.ShadowMaps.back().end(); 1868 E != EEnd; 1869 ++E) 1870 E->second.Destroy(); 1871 1872 Visible.ShadowMaps.pop_back(); 1873 } 1874}; 1875 1876} // end anonymous namespace 1877 1878void VisibleDeclsRecord::ShadowMapEntry::Add(NamedDecl *ND) { 1879 if (DeclOrVector.isNull()) { 1880 // 0 - > 1 elements: just set the single element information. 1881 DeclOrVector = ND; 1882 return; 1883 } 1884 1885 if (NamedDecl *PrevND = DeclOrVector.dyn_cast<NamedDecl *>()) { 1886 // 1 -> 2 elements: create the vector of results and push in the 1887 // existing declaration. 1888 DeclVector *Vec = new DeclVector; 1889 Vec->push_back(PrevND); 1890 DeclOrVector = Vec; 1891 } 1892 1893 // Add the new element to the end of the vector. 1894 DeclOrVector.get<DeclVector*>()->push_back(ND); 1895} 1896 1897void VisibleDeclsRecord::ShadowMapEntry::Destroy() { 1898 if (DeclVector *Vec = DeclOrVector.dyn_cast<DeclVector *>()) { 1899 delete Vec; 1900 DeclOrVector = ((NamedDecl *)0); 1901 } 1902} 1903 1904VisibleDeclsRecord::ShadowMapEntry::iterator 1905VisibleDeclsRecord::ShadowMapEntry::begin() { 1906 if (DeclOrVector.isNull()) 1907 return 0; 1908 1909 if (DeclOrVector.dyn_cast<NamedDecl *>()) 1910 return &reinterpret_cast<NamedDecl*&>(DeclOrVector); 1911 1912 return DeclOrVector.get<DeclVector *>()->begin(); 1913} 1914 1915VisibleDeclsRecord::ShadowMapEntry::iterator 1916VisibleDeclsRecord::ShadowMapEntry::end() { 1917 if (DeclOrVector.isNull()) 1918 return 0; 1919 1920 if (DeclOrVector.dyn_cast<NamedDecl *>()) 1921 return &reinterpret_cast<NamedDecl*&>(DeclOrVector) + 1; 1922 1923 return DeclOrVector.get<DeclVector *>()->end(); 1924} 1925 1926NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) { 1927 // Look through using declarations. 1928 ND = ND->getUnderlyingDecl(); 1929 1930 unsigned IDNS = ND->getIdentifierNamespace(); 1931 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin(); 1932 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend(); 1933 SM != SMEnd; ++SM) { 1934 ShadowMap::iterator Pos = SM->find(ND->getDeclName()); 1935 if (Pos == SM->end()) 1936 continue; 1937 1938 for (ShadowMapEntry::iterator I = Pos->second.begin(), 1939 IEnd = Pos->second.end(); 1940 I != IEnd; ++I) { 1941 // A tag declaration does not hide a non-tag declaration. 1942 if ((*I)->getIdentifierNamespace() == Decl::IDNS_Tag && 1943 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary | 1944 Decl::IDNS_ObjCProtocol))) 1945 continue; 1946 1947 // Protocols are in distinct namespaces from everything else. 1948 if ((((*I)->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol) 1949 || (IDNS & Decl::IDNS_ObjCProtocol)) && 1950 (*I)->getIdentifierNamespace() != IDNS) 1951 continue; 1952 1953 // Functions and function templates in the same scope overload 1954 // rather than hide. FIXME: Look for hiding based on function 1955 // signatures! 1956 if ((*I)->isFunctionOrFunctionTemplate() && 1957 ND->isFunctionOrFunctionTemplate() && 1958 SM == ShadowMaps.rbegin()) 1959 continue; 1960 1961 // We've found a declaration that hides this one. 1962 return *I; 1963 } 1964 } 1965 1966 return 0; 1967} 1968 1969static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result, 1970 bool QualifiedNameLookup, 1971 bool InBaseClass, 1972 VisibleDeclConsumer &Consumer, 1973 VisibleDeclsRecord &Visited) { 1974 // Make sure we don't visit the same context twice. 1975 if (Visited.visitedContext(Ctx->getPrimaryContext())) 1976 return; 1977 1978 // Enumerate all of the results in this context. 1979 for (DeclContext *CurCtx = Ctx->getPrimaryContext(); CurCtx; 1980 CurCtx = CurCtx->getNextContext()) { 1981 for (DeclContext::decl_iterator D = CurCtx->decls_begin(), 1982 DEnd = CurCtx->decls_end(); 1983 D != DEnd; ++D) { 1984 if (NamedDecl *ND = dyn_cast<NamedDecl>(*D)) 1985 if (Result.isAcceptableDecl(ND)) { 1986 Consumer.FoundDecl(ND, Visited.checkHidden(ND), InBaseClass); 1987 Visited.add(ND); 1988 } 1989 1990 // Visit transparent contexts inside this context. 1991 if (DeclContext *InnerCtx = dyn_cast<DeclContext>(*D)) { 1992 if (InnerCtx->isTransparentContext()) 1993 LookupVisibleDecls(InnerCtx, Result, QualifiedNameLookup, InBaseClass, 1994 Consumer, Visited); 1995 } 1996 } 1997 } 1998 1999 // Traverse using directives for qualified name lookup. 2000 if (QualifiedNameLookup) { 2001 ShadowContextRAII Shadow(Visited); 2002 DeclContext::udir_iterator I, E; 2003 for (llvm::tie(I, E) = Ctx->getUsingDirectives(); I != E; ++I) { 2004 LookupVisibleDecls((*I)->getNominatedNamespace(), Result, 2005 QualifiedNameLookup, InBaseClass, Consumer, Visited); 2006 } 2007 } 2008 2009 // Traverse the contexts of inherited C++ classes. 2010 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) { 2011 for (CXXRecordDecl::base_class_iterator B = Record->bases_begin(), 2012 BEnd = Record->bases_end(); 2013 B != BEnd; ++B) { 2014 QualType BaseType = B->getType(); 2015 2016 // Don't look into dependent bases, because name lookup can't look 2017 // there anyway. 2018 if (BaseType->isDependentType()) 2019 continue; 2020 2021 const RecordType *Record = BaseType->getAs<RecordType>(); 2022 if (!Record) 2023 continue; 2024 2025 // FIXME: It would be nice to be able to determine whether referencing 2026 // a particular member would be ambiguous. For example, given 2027 // 2028 // struct A { int member; }; 2029 // struct B { int member; }; 2030 // struct C : A, B { }; 2031 // 2032 // void f(C *c) { c->### } 2033 // 2034 // accessing 'member' would result in an ambiguity. However, we 2035 // could be smart enough to qualify the member with the base 2036 // class, e.g., 2037 // 2038 // c->B::member 2039 // 2040 // or 2041 // 2042 // c->A::member 2043 2044 // Find results in this base class (and its bases). 2045 ShadowContextRAII Shadow(Visited); 2046 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup, 2047 true, Consumer, Visited); 2048 } 2049 } 2050 2051 // Traverse the contexts of Objective-C classes. 2052 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) { 2053 // Traverse categories. 2054 for (ObjCCategoryDecl *Category = IFace->getCategoryList(); 2055 Category; Category = Category->getNextClassCategory()) { 2056 ShadowContextRAII Shadow(Visited); 2057 LookupVisibleDecls(Category, Result, QualifiedNameLookup, false, 2058 Consumer, Visited); 2059 } 2060 2061 // Traverse protocols. 2062 for (ObjCInterfaceDecl::protocol_iterator I = IFace->protocol_begin(), 2063 E = IFace->protocol_end(); I != E; ++I) { 2064 ShadowContextRAII Shadow(Visited); 2065 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2066 Visited); 2067 } 2068 2069 // Traverse the superclass. 2070 if (IFace->getSuperClass()) { 2071 ShadowContextRAII Shadow(Visited); 2072 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup, 2073 true, Consumer, Visited); 2074 } 2075 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) { 2076 for (ObjCProtocolDecl::protocol_iterator I = Protocol->protocol_begin(), 2077 E = Protocol->protocol_end(); I != E; ++I) { 2078 ShadowContextRAII Shadow(Visited); 2079 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2080 Visited); 2081 } 2082 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) { 2083 for (ObjCCategoryDecl::protocol_iterator I = Category->protocol_begin(), 2084 E = Category->protocol_end(); I != E; ++I) { 2085 ShadowContextRAII Shadow(Visited); 2086 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2087 Visited); 2088 } 2089 } 2090} 2091 2092static void LookupVisibleDecls(Scope *S, LookupResult &Result, 2093 UnqualUsingDirectiveSet &UDirs, 2094 VisibleDeclConsumer &Consumer, 2095 VisibleDeclsRecord &Visited) { 2096 if (!S) 2097 return; 2098 2099 if (!S->getEntity() || !S->getParent() || 2100 ((DeclContext *)S->getEntity())->isFunctionOrMethod()) { 2101 // Walk through the declarations in this Scope. 2102 for (Scope::decl_iterator D = S->decl_begin(), DEnd = S->decl_end(); 2103 D != DEnd; ++D) { 2104 if (NamedDecl *ND = dyn_cast<NamedDecl>((Decl *)((*D).get()))) 2105 if (Result.isAcceptableDecl(ND)) { 2106 Consumer.FoundDecl(ND, Visited.checkHidden(ND), false); 2107 Visited.add(ND); 2108 } 2109 } 2110 } 2111 2112 DeclContext *Entity = 0; 2113 if (S->getEntity()) { 2114 // Look into this scope's declaration context, along with any of its 2115 // parent lookup contexts (e.g., enclosing classes), up to the point 2116 // where we hit the context stored in the next outer scope. 2117 Entity = (DeclContext *)S->getEntity(); 2118 DeclContext *OuterCtx = findOuterContext(S); 2119 2120 for (DeclContext *Ctx = Entity; Ctx && Ctx->getPrimaryContext() != OuterCtx; 2121 Ctx = Ctx->getLookupParent()) { 2122 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 2123 if (Method->isInstanceMethod()) { 2124 // For instance methods, look for ivars in the method's interface. 2125 LookupResult IvarResult(Result.getSema(), Result.getLookupName(), 2126 Result.getNameLoc(), Sema::LookupMemberName); 2127 ObjCInterfaceDecl *IFace = Method->getClassInterface(); 2128 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false, 2129 /*InBaseClass=*/false, Consumer, Visited); 2130 } 2131 2132 // We've already performed all of the name lookup that we need 2133 // to for Objective-C methods; the next context will be the 2134 // outer scope. 2135 break; 2136 } 2137 2138 if (Ctx->isFunctionOrMethod()) 2139 continue; 2140 2141 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false, 2142 /*InBaseClass=*/false, Consumer, Visited); 2143 } 2144 } else if (!S->getParent()) { 2145 // Look into the translation unit scope. We walk through the translation 2146 // unit's declaration context, because the Scope itself won't have all of 2147 // the declarations if we loaded a precompiled header. 2148 // FIXME: We would like the translation unit's Scope object to point to the 2149 // translation unit, so we don't need this special "if" branch. However, 2150 // doing so would force the normal C++ name-lookup code to look into the 2151 // translation unit decl when the IdentifierInfo chains would suffice. 2152 // Once we fix that problem (which is part of a more general "don't look 2153 // in DeclContexts unless we have to" optimization), we can eliminate this. 2154 Entity = Result.getSema().Context.getTranslationUnitDecl(); 2155 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false, 2156 /*InBaseClass=*/false, Consumer, Visited); 2157 } 2158 2159 if (Entity) { 2160 // Lookup visible declarations in any namespaces found by using 2161 // directives. 2162 UnqualUsingDirectiveSet::const_iterator UI, UEnd; 2163 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(Entity); 2164 for (; UI != UEnd; ++UI) 2165 LookupVisibleDecls(const_cast<DeclContext *>(UI->getNominatedNamespace()), 2166 Result, /*QualifiedNameLookup=*/false, 2167 /*InBaseClass=*/false, Consumer, Visited); 2168 } 2169 2170 // Lookup names in the parent scope. 2171 ShadowContextRAII Shadow(Visited); 2172 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited); 2173} 2174 2175void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind, 2176 VisibleDeclConsumer &Consumer) { 2177 // Determine the set of using directives available during 2178 // unqualified name lookup. 2179 Scope *Initial = S; 2180 UnqualUsingDirectiveSet UDirs; 2181 if (getLangOptions().CPlusPlus) { 2182 // Find the first namespace or translation-unit scope. 2183 while (S && !isNamespaceOrTranslationUnitScope(S)) 2184 S = S->getParent(); 2185 2186 UDirs.visitScopeChain(Initial, S); 2187 } 2188 UDirs.done(); 2189 2190 // Look for visible declarations. 2191 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2192 VisibleDeclsRecord Visited; 2193 ShadowContextRAII Shadow(Visited); 2194 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited); 2195} 2196 2197void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind, 2198 VisibleDeclConsumer &Consumer) { 2199 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2200 VisibleDeclsRecord Visited; 2201 ShadowContextRAII Shadow(Visited); 2202 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true, 2203 /*InBaseClass=*/false, Consumer, Visited); 2204} 2205 2206//---------------------------------------------------------------------------- 2207// Typo correction 2208//---------------------------------------------------------------------------- 2209 2210namespace { 2211class TypoCorrectionConsumer : public VisibleDeclConsumer { 2212 /// \brief The name written that is a typo in the source. 2213 llvm::StringRef Typo; 2214 2215 /// \brief The results found that have the smallest edit distance 2216 /// found (so far) with the typo name. 2217 llvm::SmallVector<NamedDecl *, 4> BestResults; 2218 2219 /// \brief The best edit distance found so far. 2220 unsigned BestEditDistance; 2221 2222public: 2223 explicit TypoCorrectionConsumer(IdentifierInfo *Typo) 2224 : Typo(Typo->getName()) { } 2225 2226 virtual void FoundDecl(NamedDecl *ND, NamedDecl *Hiding, bool InBaseClass); 2227 2228 typedef llvm::SmallVector<NamedDecl *, 4>::const_iterator iterator; 2229 iterator begin() const { return BestResults.begin(); } 2230 iterator end() const { return BestResults.end(); } 2231 bool empty() const { return BestResults.empty(); } 2232 2233 unsigned getBestEditDistance() const { return BestEditDistance; } 2234}; 2235 2236} 2237 2238void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding, 2239 bool InBaseClass) { 2240 // Don't consider hidden names for typo correction. 2241 if (Hiding) 2242 return; 2243 2244 // Only consider entities with identifiers for names, ignoring 2245 // special names (constructors, overloaded operators, selectors, 2246 // etc.). 2247 IdentifierInfo *Name = ND->getIdentifier(); 2248 if (!Name) 2249 return; 2250 2251 // Compute the edit distance between the typo and the name of this 2252 // entity. If this edit distance is not worse than the best edit 2253 // distance we've seen so far, add it to the list of results. 2254 unsigned ED = Typo.edit_distance(Name->getName()); 2255 if (!BestResults.empty()) { 2256 if (ED < BestEditDistance) { 2257 // This result is better than any we've seen before; clear out 2258 // the previous results. 2259 BestResults.clear(); 2260 BestEditDistance = ED; 2261 } else if (ED > BestEditDistance) { 2262 // This result is worse than the best results we've seen so far; 2263 // ignore it. 2264 return; 2265 } 2266 } else 2267 BestEditDistance = ED; 2268 2269 BestResults.push_back(ND); 2270} 2271 2272/// \brief Try to "correct" a typo in the source code by finding 2273/// visible declarations whose names are similar to the name that was 2274/// present in the source code. 2275/// 2276/// \param Res the \c LookupResult structure that contains the name 2277/// that was present in the source code along with the name-lookup 2278/// criteria used to search for the name. On success, this structure 2279/// will contain the results of name lookup. 2280/// 2281/// \param S the scope in which name lookup occurs. 2282/// 2283/// \param SS the nested-name-specifier that precedes the name we're 2284/// looking for, if present. 2285/// 2286/// \param MemberContext if non-NULL, the context in which to look for 2287/// a member access expression. 2288/// 2289/// \param EnteringContext whether we're entering the context described by 2290/// the nested-name-specifier SS. 2291/// 2292/// \param OPT when non-NULL, the search for visible declarations will 2293/// also walk the protocols in the qualified interfaces of \p OPT. 2294/// 2295/// \returns true if the typo was corrected, in which case the \p Res 2296/// structure will contain the results of name lookup for the 2297/// corrected name. Otherwise, returns false. 2298bool Sema::CorrectTypo(LookupResult &Res, Scope *S, const CXXScopeSpec *SS, 2299 DeclContext *MemberContext, bool EnteringContext, 2300 const ObjCObjectPointerType *OPT) { 2301 2302 if (Diags.hasFatalErrorOccurred()) 2303 return false; 2304 2305 // We only attempt to correct typos for identifiers. 2306 IdentifierInfo *Typo = Res.getLookupName().getAsIdentifierInfo(); 2307 if (!Typo) 2308 return false; 2309 2310 // If the scope specifier itself was invalid, don't try to correct 2311 // typos. 2312 if (SS && SS->isInvalid()) 2313 return false; 2314 2315 // Never try to correct typos during template deduction or 2316 // instantiation. 2317 if (!ActiveTemplateInstantiations.empty()) 2318 return false; 2319 2320 TypoCorrectionConsumer Consumer(Typo); 2321 if (MemberContext) { 2322 LookupVisibleDecls(MemberContext, Res.getLookupKind(), Consumer); 2323 2324 // Look in qualified interfaces. 2325 if (OPT) { 2326 for (ObjCObjectPointerType::qual_iterator 2327 I = OPT->qual_begin(), E = OPT->qual_end(); 2328 I != E; ++I) 2329 LookupVisibleDecls(*I, Res.getLookupKind(), Consumer); 2330 } 2331 } else if (SS && SS->isSet()) { 2332 DeclContext *DC = computeDeclContext(*SS, EnteringContext); 2333 if (!DC) 2334 return false; 2335 2336 LookupVisibleDecls(DC, Res.getLookupKind(), Consumer); 2337 } else { 2338 LookupVisibleDecls(S, Res.getLookupKind(), Consumer); 2339 } 2340 2341 if (Consumer.empty()) 2342 return false; 2343 2344 // Only allow a single, closest name in the result set (it's okay to 2345 // have overloads of that name, though). 2346 TypoCorrectionConsumer::iterator I = Consumer.begin(); 2347 DeclarationName BestName = (*I)->getDeclName(); 2348 2349 // If we've found an Objective-C ivar or property, don't perform 2350 // name lookup again; we'll just return the result directly. 2351 NamedDecl *FoundBest = 0; 2352 if (isa<ObjCIvarDecl>(*I) || isa<ObjCPropertyDecl>(*I)) 2353 FoundBest = *I; 2354 ++I; 2355 for(TypoCorrectionConsumer::iterator IEnd = Consumer.end(); I != IEnd; ++I) { 2356 if (BestName != (*I)->getDeclName()) 2357 return false; 2358 2359 // FIXME: If there are both ivars and properties of the same name, 2360 // don't return both because the callee can't handle two 2361 // results. We really need to separate ivar lookup from property 2362 // lookup to avoid this problem. 2363 FoundBest = 0; 2364 } 2365 2366 // BestName is the closest viable name to what the user 2367 // typed. However, to make sure that we don't pick something that's 2368 // way off, make sure that the user typed at least 3 characters for 2369 // each correction. 2370 unsigned ED = Consumer.getBestEditDistance(); 2371 if (ED == 0 || (BestName.getAsIdentifierInfo()->getName().size() / ED) < 3) 2372 return false; 2373 2374 // Perform name lookup again with the name we chose, and declare 2375 // success if we found something that was not ambiguous. 2376 Res.clear(); 2377 Res.setLookupName(BestName); 2378 2379 // If we found an ivar or property, add that result; no further 2380 // lookup is required. 2381 if (FoundBest) 2382 Res.addDecl(FoundBest); 2383 // If we're looking into the context of a member, perform qualified 2384 // name lookup on the best name. 2385 else if (MemberContext) 2386 LookupQualifiedName(Res, MemberContext); 2387 // Perform lookup as if we had just parsed the best name. 2388 else 2389 LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false, 2390 EnteringContext); 2391 2392 if (Res.isAmbiguous()) { 2393 Res.suppressDiagnostics(); 2394 return false; 2395 } 2396 2397 return Res.getResultKind() != LookupResult::NotFound; 2398} 2399