SemaLookup.cpp revision e77dce286d4ad171e2eba021aa2bc9666a90124f
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 NamedDecl *D = *I; 449 if (R.isAcceptableDecl(D)) { 450 R.addDecl(D); 451 Found = true; 452 } 453 } 454 455 if (R.getLookupName().getNameKind() 456 != DeclarationName::CXXConversionFunctionName || 457 R.getLookupName().getCXXNameType()->isDependentType() || 458 !isa<CXXRecordDecl>(DC)) 459 return Found; 460 461 // C++ [temp.mem]p6: 462 // A specialization of a conversion function template is not found by 463 // name lookup. Instead, any conversion function templates visible in the 464 // context of the use are considered. [...] 465 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC); 466 if (!Record->isDefinition()) 467 return Found; 468 469 const UnresolvedSetImpl *Unresolved = Record->getConversionFunctions(); 470 for (UnresolvedSetImpl::iterator U = Unresolved->begin(), 471 UEnd = Unresolved->end(); U != UEnd; ++U) { 472 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U); 473 if (!ConvTemplate) 474 continue; 475 476 // When we're performing lookup for the purposes of redeclaration, just 477 // add the conversion function template. When we deduce template 478 // arguments for specializations, we'll end up unifying the return 479 // type of the new declaration with the type of the function template. 480 if (R.isForRedeclaration()) { 481 R.addDecl(ConvTemplate); 482 Found = true; 483 continue; 484 } 485 486 // C++ [temp.mem]p6: 487 // [...] For each such operator, if argument deduction succeeds 488 // (14.9.2.3), the resulting specialization is used as if found by 489 // name lookup. 490 // 491 // When referencing a conversion function for any purpose other than 492 // a redeclaration (such that we'll be building an expression with the 493 // result), perform template argument deduction and place the 494 // specialization into the result set. We do this to avoid forcing all 495 // callers to perform special deduction for conversion functions. 496 Sema::TemplateDeductionInfo Info(R.getSema().Context); 497 FunctionDecl *Specialization = 0; 498 499 const FunctionProtoType *ConvProto 500 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>(); 501 assert(ConvProto && "Nonsensical conversion function template type"); 502 503 // Compute the type of the function that we would expect the conversion 504 // function to have, if it were to match the name given. 505 // FIXME: Calling convention! 506 QualType ExpectedType 507 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(), 508 0, 0, ConvProto->isVariadic(), 509 ConvProto->getTypeQuals(), 510 false, false, 0, 0, 511 ConvProto->getNoReturnAttr()); 512 513 // Perform template argument deduction against the type that we would 514 // expect the function to have. 515 if (R.getSema().DeduceTemplateArguments(ConvTemplate, 0, ExpectedType, 516 Specialization, Info) 517 == Sema::TDK_Success) { 518 R.addDecl(Specialization); 519 Found = true; 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 if (isa<CXXRecordDecl>(LookupCtx)) 970 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx)); 971 return true; 972 } 973 974 // Don't descend into implied contexts for redeclarations. 975 // C++98 [namespace.qual]p6: 976 // In a declaration for a namespace member in which the 977 // declarator-id is a qualified-id, given that the qualified-id 978 // for the namespace member has the form 979 // nested-name-specifier unqualified-id 980 // the unqualified-id shall name a member of the namespace 981 // designated by the nested-name-specifier. 982 // See also [class.mfct]p5 and [class.static.data]p2. 983 if (R.isForRedeclaration()) 984 return false; 985 986 // If this is a namespace, look it up in the implied namespaces. 987 if (LookupCtx->isFileContext()) 988 return LookupQualifiedNameInUsingDirectives(R, LookupCtx); 989 990 // If this isn't a C++ class, we aren't allowed to look into base 991 // classes, we're done. 992 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx); 993 if (!LookupRec) 994 return false; 995 996 // If we're performing qualified name lookup into a dependent class, 997 // then we are actually looking into a current instantiation. If we have any 998 // dependent base classes, then we either have to delay lookup until 999 // template instantiation time (at which point all bases will be available) 1000 // or we have to fail. 1001 if (!InUnqualifiedLookup && LookupRec->isDependentContext() && 1002 LookupRec->hasAnyDependentBases()) { 1003 R.setNotFoundInCurrentInstantiation(); 1004 return false; 1005 } 1006 1007 // Perform lookup into our base classes. 1008 CXXBasePaths Paths; 1009 Paths.setOrigin(LookupRec); 1010 1011 // Look for this member in our base classes 1012 CXXRecordDecl::BaseMatchesCallback *BaseCallback = 0; 1013 switch (R.getLookupKind()) { 1014 case LookupOrdinaryName: 1015 case LookupMemberName: 1016 case LookupRedeclarationWithLinkage: 1017 BaseCallback = &CXXRecordDecl::FindOrdinaryMember; 1018 break; 1019 1020 case LookupTagName: 1021 BaseCallback = &CXXRecordDecl::FindTagMember; 1022 break; 1023 1024 case LookupUsingDeclName: 1025 // This lookup is for redeclarations only. 1026 1027 case LookupOperatorName: 1028 case LookupNamespaceName: 1029 case LookupObjCProtocolName: 1030 case LookupObjCImplementationName: 1031 // These lookups will never find a member in a C++ class (or base class). 1032 return false; 1033 1034 case LookupNestedNameSpecifierName: 1035 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember; 1036 break; 1037 } 1038 1039 if (!LookupRec->lookupInBases(BaseCallback, 1040 R.getLookupName().getAsOpaquePtr(), Paths)) 1041 return false; 1042 1043 R.setNamingClass(LookupRec); 1044 1045 // C++ [class.member.lookup]p2: 1046 // [...] If the resulting set of declarations are not all from 1047 // sub-objects of the same type, or the set has a nonstatic member 1048 // and includes members from distinct sub-objects, there is an 1049 // ambiguity and the program is ill-formed. Otherwise that set is 1050 // the result of the lookup. 1051 // FIXME: support using declarations! 1052 QualType SubobjectType; 1053 int SubobjectNumber = 0; 1054 AccessSpecifier SubobjectAccess = AS_private; 1055 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); 1056 Path != PathEnd; ++Path) { 1057 const CXXBasePathElement &PathElement = Path->back(); 1058 1059 // Pick the best (i.e. most permissive i.e. numerically lowest) access 1060 // across all paths. 1061 SubobjectAccess = std::min(SubobjectAccess, Path->Access); 1062 1063 // Determine whether we're looking at a distinct sub-object or not. 1064 if (SubobjectType.isNull()) { 1065 // This is the first subobject we've looked at. Record its type. 1066 SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); 1067 SubobjectNumber = PathElement.SubobjectNumber; 1068 } else if (SubobjectType 1069 != Context.getCanonicalType(PathElement.Base->getType())) { 1070 // We found members of the given name in two subobjects of 1071 // different types. This lookup is ambiguous. 1072 R.setAmbiguousBaseSubobjectTypes(Paths); 1073 return true; 1074 } else if (SubobjectNumber != PathElement.SubobjectNumber) { 1075 // We have a different subobject of the same type. 1076 1077 // C++ [class.member.lookup]p5: 1078 // A static member, a nested type or an enumerator defined in 1079 // a base class T can unambiguously be found even if an object 1080 // has more than one base class subobject of type T. 1081 Decl *FirstDecl = *Path->Decls.first; 1082 if (isa<VarDecl>(FirstDecl) || 1083 isa<TypeDecl>(FirstDecl) || 1084 isa<EnumConstantDecl>(FirstDecl)) 1085 continue; 1086 1087 if (isa<CXXMethodDecl>(FirstDecl)) { 1088 // Determine whether all of the methods are static. 1089 bool AllMethodsAreStatic = true; 1090 for (DeclContext::lookup_iterator Func = Path->Decls.first; 1091 Func != Path->Decls.second; ++Func) { 1092 if (!isa<CXXMethodDecl>(*Func)) { 1093 assert(isa<TagDecl>(*Func) && "Non-function must be a tag decl"); 1094 break; 1095 } 1096 1097 if (!cast<CXXMethodDecl>(*Func)->isStatic()) { 1098 AllMethodsAreStatic = false; 1099 break; 1100 } 1101 } 1102 1103 if (AllMethodsAreStatic) 1104 continue; 1105 } 1106 1107 // We have found a nonstatic member name in multiple, distinct 1108 // subobjects. Name lookup is ambiguous. 1109 R.setAmbiguousBaseSubobjects(Paths); 1110 return true; 1111 } 1112 } 1113 1114 // Lookup in a base class succeeded; return these results. 1115 1116 DeclContext::lookup_iterator I, E; 1117 for (llvm::tie(I,E) = Paths.front().Decls; I != E; ++I) { 1118 NamedDecl *D = *I; 1119 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess, 1120 D->getAccess()); 1121 R.addDecl(D, AS); 1122 } 1123 R.resolveKind(); 1124 return true; 1125} 1126 1127/// @brief Performs name lookup for a name that was parsed in the 1128/// source code, and may contain a C++ scope specifier. 1129/// 1130/// This routine is a convenience routine meant to be called from 1131/// contexts that receive a name and an optional C++ scope specifier 1132/// (e.g., "N::M::x"). It will then perform either qualified or 1133/// unqualified name lookup (with LookupQualifiedName or LookupName, 1134/// respectively) on the given name and return those results. 1135/// 1136/// @param S The scope from which unqualified name lookup will 1137/// begin. 1138/// 1139/// @param SS An optional C++ scope-specifier, e.g., "::N::M". 1140/// 1141/// @param Name The name of the entity that name lookup will 1142/// search for. 1143/// 1144/// @param Loc If provided, the source location where we're performing 1145/// name lookup. At present, this is only used to produce diagnostics when 1146/// C library functions (like "malloc") are implicitly declared. 1147/// 1148/// @param EnteringContext Indicates whether we are going to enter the 1149/// context of the scope-specifier SS (if present). 1150/// 1151/// @returns True if any decls were found (but possibly ambiguous) 1152bool Sema::LookupParsedName(LookupResult &R, Scope *S, const CXXScopeSpec *SS, 1153 bool AllowBuiltinCreation, bool EnteringContext) { 1154 if (SS && SS->isInvalid()) { 1155 // When the scope specifier is invalid, don't even look for 1156 // anything. 1157 return false; 1158 } 1159 1160 if (SS && SS->isSet()) { 1161 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { 1162 // We have resolved the scope specifier to a particular declaration 1163 // contex, and will perform name lookup in that context. 1164 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS)) 1165 return false; 1166 1167 R.setContextRange(SS->getRange()); 1168 1169 return LookupQualifiedName(R, DC); 1170 } 1171 1172 // We could not resolve the scope specified to a specific declaration 1173 // context, which means that SS refers to an unknown specialization. 1174 // Name lookup can't find anything in this case. 1175 return false; 1176 } 1177 1178 // Perform unqualified name lookup starting in the given scope. 1179 return LookupName(R, S, AllowBuiltinCreation); 1180} 1181 1182 1183/// @brief Produce a diagnostic describing the ambiguity that resulted 1184/// from name lookup. 1185/// 1186/// @param Result The ambiguous name lookup result. 1187/// 1188/// @param Name The name of the entity that name lookup was 1189/// searching for. 1190/// 1191/// @param NameLoc The location of the name within the source code. 1192/// 1193/// @param LookupRange A source range that provides more 1194/// source-location information concerning the lookup itself. For 1195/// example, this range might highlight a nested-name-specifier that 1196/// precedes the name. 1197/// 1198/// @returns true 1199bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result) { 1200 assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); 1201 1202 DeclarationName Name = Result.getLookupName(); 1203 SourceLocation NameLoc = Result.getNameLoc(); 1204 SourceRange LookupRange = Result.getContextRange(); 1205 1206 switch (Result.getAmbiguityKind()) { 1207 case LookupResult::AmbiguousBaseSubobjects: { 1208 CXXBasePaths *Paths = Result.getBasePaths(); 1209 QualType SubobjectType = Paths->front().back().Base->getType(); 1210 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) 1211 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) 1212 << LookupRange; 1213 1214 DeclContext::lookup_iterator Found = Paths->front().Decls.first; 1215 while (isa<CXXMethodDecl>(*Found) && 1216 cast<CXXMethodDecl>(*Found)->isStatic()) 1217 ++Found; 1218 1219 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); 1220 1221 return true; 1222 } 1223 1224 case LookupResult::AmbiguousBaseSubobjectTypes: { 1225 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) 1226 << Name << LookupRange; 1227 1228 CXXBasePaths *Paths = Result.getBasePaths(); 1229 std::set<Decl *> DeclsPrinted; 1230 for (CXXBasePaths::paths_iterator Path = Paths->begin(), 1231 PathEnd = Paths->end(); 1232 Path != PathEnd; ++Path) { 1233 Decl *D = *Path->Decls.first; 1234 if (DeclsPrinted.insert(D).second) 1235 Diag(D->getLocation(), diag::note_ambiguous_member_found); 1236 } 1237 1238 return true; 1239 } 1240 1241 case LookupResult::AmbiguousTagHiding: { 1242 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange; 1243 1244 llvm::SmallPtrSet<NamedDecl*,8> TagDecls; 1245 1246 LookupResult::iterator DI, DE = Result.end(); 1247 for (DI = Result.begin(); DI != DE; ++DI) 1248 if (TagDecl *TD = dyn_cast<TagDecl>(*DI)) { 1249 TagDecls.insert(TD); 1250 Diag(TD->getLocation(), diag::note_hidden_tag); 1251 } 1252 1253 for (DI = Result.begin(); DI != DE; ++DI) 1254 if (!isa<TagDecl>(*DI)) 1255 Diag((*DI)->getLocation(), diag::note_hiding_object); 1256 1257 // For recovery purposes, go ahead and implement the hiding. 1258 LookupResult::Filter F = Result.makeFilter(); 1259 while (F.hasNext()) { 1260 if (TagDecls.count(F.next())) 1261 F.erase(); 1262 } 1263 F.done(); 1264 1265 return true; 1266 } 1267 1268 case LookupResult::AmbiguousReference: { 1269 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; 1270 1271 LookupResult::iterator DI = Result.begin(), DE = Result.end(); 1272 for (; DI != DE; ++DI) 1273 Diag((*DI)->getLocation(), diag::note_ambiguous_candidate) << *DI; 1274 1275 return true; 1276 } 1277 } 1278 1279 llvm_unreachable("unknown ambiguity kind"); 1280 return true; 1281} 1282 1283static void 1284addAssociatedClassesAndNamespaces(QualType T, 1285 ASTContext &Context, 1286 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1287 Sema::AssociatedClassSet &AssociatedClasses); 1288 1289static void CollectNamespace(Sema::AssociatedNamespaceSet &Namespaces, 1290 DeclContext *Ctx) { 1291 if (Ctx->isFileContext()) 1292 Namespaces.insert(Ctx); 1293} 1294 1295// \brief Add the associated classes and namespaces for argument-dependent 1296// lookup that involves a template argument (C++ [basic.lookup.koenig]p2). 1297static void 1298addAssociatedClassesAndNamespaces(const TemplateArgument &Arg, 1299 ASTContext &Context, 1300 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1301 Sema::AssociatedClassSet &AssociatedClasses) { 1302 // C++ [basic.lookup.koenig]p2, last bullet: 1303 // -- [...] ; 1304 switch (Arg.getKind()) { 1305 case TemplateArgument::Null: 1306 break; 1307 1308 case TemplateArgument::Type: 1309 // [...] the namespaces and classes associated with the types of the 1310 // template arguments provided for template type parameters (excluding 1311 // template template parameters) 1312 addAssociatedClassesAndNamespaces(Arg.getAsType(), Context, 1313 AssociatedNamespaces, 1314 AssociatedClasses); 1315 break; 1316 1317 case TemplateArgument::Template: { 1318 // [...] the namespaces in which any template template arguments are 1319 // defined; and the classes in which any member templates used as 1320 // template template arguments are defined. 1321 TemplateName Template = Arg.getAsTemplate(); 1322 if (ClassTemplateDecl *ClassTemplate 1323 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) { 1324 DeclContext *Ctx = ClassTemplate->getDeclContext(); 1325 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1326 AssociatedClasses.insert(EnclosingClass); 1327 // Add the associated namespace for this class. 1328 while (Ctx->isRecord()) 1329 Ctx = Ctx->getParent(); 1330 CollectNamespace(AssociatedNamespaces, Ctx); 1331 } 1332 break; 1333 } 1334 1335 case TemplateArgument::Declaration: 1336 case TemplateArgument::Integral: 1337 case TemplateArgument::Expression: 1338 // [Note: non-type template arguments do not contribute to the set of 1339 // associated namespaces. ] 1340 break; 1341 1342 case TemplateArgument::Pack: 1343 for (TemplateArgument::pack_iterator P = Arg.pack_begin(), 1344 PEnd = Arg.pack_end(); 1345 P != PEnd; ++P) 1346 addAssociatedClassesAndNamespaces(*P, Context, 1347 AssociatedNamespaces, 1348 AssociatedClasses); 1349 break; 1350 } 1351} 1352 1353// \brief Add the associated classes and namespaces for 1354// argument-dependent lookup with an argument of class type 1355// (C++ [basic.lookup.koenig]p2). 1356static void 1357addAssociatedClassesAndNamespaces(CXXRecordDecl *Class, 1358 ASTContext &Context, 1359 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1360 Sema::AssociatedClassSet &AssociatedClasses) { 1361 // C++ [basic.lookup.koenig]p2: 1362 // [...] 1363 // -- If T is a class type (including unions), its associated 1364 // classes are: the class itself; the class of which it is a 1365 // member, if any; and its direct and indirect base 1366 // classes. Its associated namespaces are the namespaces in 1367 // which its associated classes are defined. 1368 1369 // Add the class of which it is a member, if any. 1370 DeclContext *Ctx = Class->getDeclContext(); 1371 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1372 AssociatedClasses.insert(EnclosingClass); 1373 // Add the associated namespace for this class. 1374 while (Ctx->isRecord()) 1375 Ctx = Ctx->getParent(); 1376 CollectNamespace(AssociatedNamespaces, Ctx); 1377 1378 // Add the class itself. If we've already seen this class, we don't 1379 // need to visit base classes. 1380 if (!AssociatedClasses.insert(Class)) 1381 return; 1382 1383 // -- If T is a template-id, its associated namespaces and classes are 1384 // the namespace in which the template is defined; for member 1385 // templates, the member template’s class; the namespaces and classes 1386 // associated with the types of the template arguments provided for 1387 // template type parameters (excluding template template parameters); the 1388 // namespaces in which any template template arguments are defined; and 1389 // the classes in which any member templates used as template template 1390 // arguments are defined. [Note: non-type template arguments do not 1391 // contribute to the set of associated namespaces. ] 1392 if (ClassTemplateSpecializationDecl *Spec 1393 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) { 1394 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); 1395 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1396 AssociatedClasses.insert(EnclosingClass); 1397 // Add the associated namespace for this class. 1398 while (Ctx->isRecord()) 1399 Ctx = Ctx->getParent(); 1400 CollectNamespace(AssociatedNamespaces, Ctx); 1401 1402 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); 1403 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 1404 addAssociatedClassesAndNamespaces(TemplateArgs[I], Context, 1405 AssociatedNamespaces, 1406 AssociatedClasses); 1407 } 1408 1409 // Add direct and indirect base classes along with their associated 1410 // namespaces. 1411 llvm::SmallVector<CXXRecordDecl *, 32> Bases; 1412 Bases.push_back(Class); 1413 while (!Bases.empty()) { 1414 // Pop this class off the stack. 1415 Class = Bases.back(); 1416 Bases.pop_back(); 1417 1418 // Visit the base classes. 1419 for (CXXRecordDecl::base_class_iterator Base = Class->bases_begin(), 1420 BaseEnd = Class->bases_end(); 1421 Base != BaseEnd; ++Base) { 1422 const RecordType *BaseType = Base->getType()->getAs<RecordType>(); 1423 // In dependent contexts, we do ADL twice, and the first time around, 1424 // the base type might be a dependent TemplateSpecializationType, or a 1425 // TemplateTypeParmType. If that happens, simply ignore it. 1426 // FIXME: If we want to support export, we probably need to add the 1427 // namespace of the template in a TemplateSpecializationType, or even 1428 // the classes and namespaces of known non-dependent arguments. 1429 if (!BaseType) 1430 continue; 1431 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 1432 if (AssociatedClasses.insert(BaseDecl)) { 1433 // Find the associated namespace for this base class. 1434 DeclContext *BaseCtx = BaseDecl->getDeclContext(); 1435 while (BaseCtx->isRecord()) 1436 BaseCtx = BaseCtx->getParent(); 1437 CollectNamespace(AssociatedNamespaces, BaseCtx); 1438 1439 // Make sure we visit the bases of this base class. 1440 if (BaseDecl->bases_begin() != BaseDecl->bases_end()) 1441 Bases.push_back(BaseDecl); 1442 } 1443 } 1444 } 1445} 1446 1447// \brief Add the associated classes and namespaces for 1448// argument-dependent lookup with an argument of type T 1449// (C++ [basic.lookup.koenig]p2). 1450static void 1451addAssociatedClassesAndNamespaces(QualType T, 1452 ASTContext &Context, 1453 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1454 Sema::AssociatedClassSet &AssociatedClasses) { 1455 // C++ [basic.lookup.koenig]p2: 1456 // 1457 // For each argument type T in the function call, there is a set 1458 // of zero or more associated namespaces and a set of zero or more 1459 // associated classes to be considered. The sets of namespaces and 1460 // classes is determined entirely by the types of the function 1461 // arguments (and the namespace of any template template 1462 // argument). Typedef names and using-declarations used to specify 1463 // the types do not contribute to this set. The sets of namespaces 1464 // and classes are determined in the following way: 1465 T = Context.getCanonicalType(T).getUnqualifiedType(); 1466 1467 // -- If T is a pointer to U or an array of U, its associated 1468 // namespaces and classes are those associated with U. 1469 // 1470 // We handle this by unwrapping pointer and array types immediately, 1471 // to avoid unnecessary recursion. 1472 while (true) { 1473 if (const PointerType *Ptr = T->getAs<PointerType>()) 1474 T = Ptr->getPointeeType(); 1475 else if (const ArrayType *Ptr = Context.getAsArrayType(T)) 1476 T = Ptr->getElementType(); 1477 else 1478 break; 1479 } 1480 1481 // -- If T is a fundamental type, its associated sets of 1482 // namespaces and classes are both empty. 1483 if (T->getAs<BuiltinType>()) 1484 return; 1485 1486 // -- If T is a class type (including unions), its associated 1487 // classes are: the class itself; the class of which it is a 1488 // member, if any; and its direct and indirect base 1489 // classes. Its associated namespaces are the namespaces in 1490 // which its associated classes are defined. 1491 if (const RecordType *ClassType = T->getAs<RecordType>()) 1492 if (CXXRecordDecl *ClassDecl 1493 = dyn_cast<CXXRecordDecl>(ClassType->getDecl())) { 1494 addAssociatedClassesAndNamespaces(ClassDecl, Context, 1495 AssociatedNamespaces, 1496 AssociatedClasses); 1497 return; 1498 } 1499 1500 // -- If T is an enumeration type, its associated namespace is 1501 // the namespace in which it is defined. If it is class 1502 // member, its associated class is the member’s class; else 1503 // it has no associated class. 1504 if (const EnumType *EnumT = T->getAs<EnumType>()) { 1505 EnumDecl *Enum = EnumT->getDecl(); 1506 1507 DeclContext *Ctx = Enum->getDeclContext(); 1508 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1509 AssociatedClasses.insert(EnclosingClass); 1510 1511 // Add the associated namespace for this class. 1512 while (Ctx->isRecord()) 1513 Ctx = Ctx->getParent(); 1514 CollectNamespace(AssociatedNamespaces, Ctx); 1515 1516 return; 1517 } 1518 1519 // -- If T is a function type, its associated namespaces and 1520 // classes are those associated with the function parameter 1521 // types and those associated with the return type. 1522 if (const FunctionType *FnType = T->getAs<FunctionType>()) { 1523 // Return type 1524 addAssociatedClassesAndNamespaces(FnType->getResultType(), 1525 Context, 1526 AssociatedNamespaces, AssociatedClasses); 1527 1528 const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FnType); 1529 if (!Proto) 1530 return; 1531 1532 // Argument types 1533 for (FunctionProtoType::arg_type_iterator Arg = Proto->arg_type_begin(), 1534 ArgEnd = Proto->arg_type_end(); 1535 Arg != ArgEnd; ++Arg) 1536 addAssociatedClassesAndNamespaces(*Arg, Context, 1537 AssociatedNamespaces, AssociatedClasses); 1538 1539 return; 1540 } 1541 1542 // -- If T is a pointer to a member function of a class X, its 1543 // associated namespaces and classes are those associated 1544 // with the function parameter types and return type, 1545 // together with those associated with X. 1546 // 1547 // -- If T is a pointer to a data member of class X, its 1548 // associated namespaces and classes are those associated 1549 // with the member type together with those associated with 1550 // X. 1551 if (const MemberPointerType *MemberPtr = T->getAs<MemberPointerType>()) { 1552 // Handle the type that the pointer to member points to. 1553 addAssociatedClassesAndNamespaces(MemberPtr->getPointeeType(), 1554 Context, 1555 AssociatedNamespaces, 1556 AssociatedClasses); 1557 1558 // Handle the class type into which this points. 1559 if (const RecordType *Class = MemberPtr->getClass()->getAs<RecordType>()) 1560 addAssociatedClassesAndNamespaces(cast<CXXRecordDecl>(Class->getDecl()), 1561 Context, 1562 AssociatedNamespaces, 1563 AssociatedClasses); 1564 1565 return; 1566 } 1567 1568 // FIXME: What about block pointers? 1569 // FIXME: What about Objective-C message sends? 1570} 1571 1572/// \brief Find the associated classes and namespaces for 1573/// argument-dependent lookup for a call with the given set of 1574/// arguments. 1575/// 1576/// This routine computes the sets of associated classes and associated 1577/// namespaces searched by argument-dependent lookup 1578/// (C++ [basic.lookup.argdep]) for a given set of arguments. 1579void 1580Sema::FindAssociatedClassesAndNamespaces(Expr **Args, unsigned NumArgs, 1581 AssociatedNamespaceSet &AssociatedNamespaces, 1582 AssociatedClassSet &AssociatedClasses) { 1583 AssociatedNamespaces.clear(); 1584 AssociatedClasses.clear(); 1585 1586 // C++ [basic.lookup.koenig]p2: 1587 // For each argument type T in the function call, there is a set 1588 // of zero or more associated namespaces and a set of zero or more 1589 // associated classes to be considered. The sets of namespaces and 1590 // classes is determined entirely by the types of the function 1591 // arguments (and the namespace of any template template 1592 // argument). 1593 for (unsigned ArgIdx = 0; ArgIdx != NumArgs; ++ArgIdx) { 1594 Expr *Arg = Args[ArgIdx]; 1595 1596 if (Arg->getType() != Context.OverloadTy) { 1597 addAssociatedClassesAndNamespaces(Arg->getType(), Context, 1598 AssociatedNamespaces, 1599 AssociatedClasses); 1600 continue; 1601 } 1602 1603 // [...] In addition, if the argument is the name or address of a 1604 // set of overloaded functions and/or function templates, its 1605 // associated classes and namespaces are the union of those 1606 // associated with each of the members of the set: the namespace 1607 // in which the function or function template is defined and the 1608 // classes and namespaces associated with its (non-dependent) 1609 // parameter types and return type. 1610 Arg = Arg->IgnoreParens(); 1611 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg)) 1612 if (unaryOp->getOpcode() == UnaryOperator::AddrOf) 1613 Arg = unaryOp->getSubExpr(); 1614 1615 // TODO: avoid the copies. This should be easy when the cases 1616 // share a storage implementation. 1617 llvm::SmallVector<NamedDecl*, 8> Functions; 1618 1619 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg)) 1620 Functions.append(ULE->decls_begin(), ULE->decls_end()); 1621 else 1622 continue; 1623 1624 for (llvm::SmallVectorImpl<NamedDecl*>::iterator I = Functions.begin(), 1625 E = Functions.end(); I != E; ++I) { 1626 // Look through any using declarations to find the underlying function. 1627 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 1628 1629 FunctionDecl *FDecl = dyn_cast<FunctionDecl>(Fn); 1630 if (!FDecl) 1631 FDecl = cast<FunctionTemplateDecl>(Fn)->getTemplatedDecl(); 1632 1633 // Add the classes and namespaces associated with the parameter 1634 // types and return type of this function. 1635 addAssociatedClassesAndNamespaces(FDecl->getType(), Context, 1636 AssociatedNamespaces, 1637 AssociatedClasses); 1638 } 1639 } 1640} 1641 1642/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is 1643/// an acceptable non-member overloaded operator for a call whose 1644/// arguments have types T1 (and, if non-empty, T2). This routine 1645/// implements the check in C++ [over.match.oper]p3b2 concerning 1646/// enumeration types. 1647static bool 1648IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn, 1649 QualType T1, QualType T2, 1650 ASTContext &Context) { 1651 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType())) 1652 return true; 1653 1654 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType())) 1655 return true; 1656 1657 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>(); 1658 if (Proto->getNumArgs() < 1) 1659 return false; 1660 1661 if (T1->isEnumeralType()) { 1662 QualType ArgType = Proto->getArgType(0).getNonReferenceType(); 1663 if (Context.hasSameUnqualifiedType(T1, ArgType)) 1664 return true; 1665 } 1666 1667 if (Proto->getNumArgs() < 2) 1668 return false; 1669 1670 if (!T2.isNull() && T2->isEnumeralType()) { 1671 QualType ArgType = Proto->getArgType(1).getNonReferenceType(); 1672 if (Context.hasSameUnqualifiedType(T2, ArgType)) 1673 return true; 1674 } 1675 1676 return false; 1677} 1678 1679NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name, 1680 LookupNameKind NameKind, 1681 RedeclarationKind Redecl) { 1682 LookupResult R(*this, Name, SourceLocation(), NameKind, Redecl); 1683 LookupName(R, S); 1684 return R.getAsSingle<NamedDecl>(); 1685} 1686 1687/// \brief Find the protocol with the given name, if any. 1688ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II) { 1689 Decl *D = LookupSingleName(TUScope, II, LookupObjCProtocolName); 1690 return cast_or_null<ObjCProtocolDecl>(D); 1691} 1692 1693void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, 1694 QualType T1, QualType T2, 1695 UnresolvedSetImpl &Functions) { 1696 // C++ [over.match.oper]p3: 1697 // -- The set of non-member candidates is the result of the 1698 // unqualified lookup of operator@ in the context of the 1699 // expression according to the usual rules for name lookup in 1700 // unqualified function calls (3.4.2) except that all member 1701 // functions are ignored. However, if no operand has a class 1702 // type, only those non-member functions in the lookup set 1703 // that have a first parameter of type T1 or "reference to 1704 // (possibly cv-qualified) T1", when T1 is an enumeration 1705 // type, or (if there is a right operand) a second parameter 1706 // of type T2 or "reference to (possibly cv-qualified) T2", 1707 // when T2 is an enumeration type, are candidate functions. 1708 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 1709 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName); 1710 LookupName(Operators, S); 1711 1712 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); 1713 1714 if (Operators.empty()) 1715 return; 1716 1717 for (LookupResult::iterator Op = Operators.begin(), OpEnd = Operators.end(); 1718 Op != OpEnd; ++Op) { 1719 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Op)) { 1720 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context)) 1721 Functions.addDecl(FD, Op.getAccess()); // FIXME: canonical FD 1722 } else if (FunctionTemplateDecl *FunTmpl 1723 = dyn_cast<FunctionTemplateDecl>(*Op)) { 1724 // FIXME: friend operators? 1725 // FIXME: do we need to check IsAcceptableNonMemberOperatorCandidate, 1726 // later? 1727 if (!FunTmpl->getDeclContext()->isRecord()) 1728 Functions.addDecl(FunTmpl, Op.getAccess()); 1729 } 1730 } 1731} 1732 1733void ADLResult::insert(NamedDecl *New) { 1734 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())]; 1735 1736 // If we haven't yet seen a decl for this key, or the last decl 1737 // was exactly this one, we're done. 1738 if (Old == 0 || Old == New) { 1739 Old = New; 1740 return; 1741 } 1742 1743 // Otherwise, decide which is a more recent redeclaration. 1744 FunctionDecl *OldFD, *NewFD; 1745 if (isa<FunctionTemplateDecl>(New)) { 1746 OldFD = cast<FunctionTemplateDecl>(Old)->getTemplatedDecl(); 1747 NewFD = cast<FunctionTemplateDecl>(New)->getTemplatedDecl(); 1748 } else { 1749 OldFD = cast<FunctionDecl>(Old); 1750 NewFD = cast<FunctionDecl>(New); 1751 } 1752 1753 FunctionDecl *Cursor = NewFD; 1754 while (true) { 1755 Cursor = Cursor->getPreviousDeclaration(); 1756 1757 // If we got to the end without finding OldFD, OldFD is the newer 1758 // declaration; leave things as they are. 1759 if (!Cursor) return; 1760 1761 // If we do find OldFD, then NewFD is newer. 1762 if (Cursor == OldFD) break; 1763 1764 // Otherwise, keep looking. 1765 } 1766 1767 Old = New; 1768} 1769 1770void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator, 1771 Expr **Args, unsigned NumArgs, 1772 ADLResult &Result) { 1773 // Find all of the associated namespaces and classes based on the 1774 // arguments we have. 1775 AssociatedNamespaceSet AssociatedNamespaces; 1776 AssociatedClassSet AssociatedClasses; 1777 FindAssociatedClassesAndNamespaces(Args, NumArgs, 1778 AssociatedNamespaces, 1779 AssociatedClasses); 1780 1781 QualType T1, T2; 1782 if (Operator) { 1783 T1 = Args[0]->getType(); 1784 if (NumArgs >= 2) 1785 T2 = Args[1]->getType(); 1786 } 1787 1788 // C++ [basic.lookup.argdep]p3: 1789 // Let X be the lookup set produced by unqualified lookup (3.4.1) 1790 // and let Y be the lookup set produced by argument dependent 1791 // lookup (defined as follows). If X contains [...] then Y is 1792 // empty. Otherwise Y is the set of declarations found in the 1793 // namespaces associated with the argument types as described 1794 // below. The set of declarations found by the lookup of the name 1795 // is the union of X and Y. 1796 // 1797 // Here, we compute Y and add its members to the overloaded 1798 // candidate set. 1799 for (AssociatedNamespaceSet::iterator NS = AssociatedNamespaces.begin(), 1800 NSEnd = AssociatedNamespaces.end(); 1801 NS != NSEnd; ++NS) { 1802 // When considering an associated namespace, the lookup is the 1803 // same as the lookup performed when the associated namespace is 1804 // used as a qualifier (3.4.3.2) except that: 1805 // 1806 // -- Any using-directives in the associated namespace are 1807 // ignored. 1808 // 1809 // -- Any namespace-scope friend functions declared in 1810 // associated classes are visible within their respective 1811 // namespaces even if they are not visible during an ordinary 1812 // lookup (11.4). 1813 DeclContext::lookup_iterator I, E; 1814 for (llvm::tie(I, E) = (*NS)->lookup(Name); I != E; ++I) { 1815 NamedDecl *D = *I; 1816 // If the only declaration here is an ordinary friend, consider 1817 // it only if it was declared in an associated classes. 1818 if (D->getIdentifierNamespace() == Decl::IDNS_OrdinaryFriend) { 1819 DeclContext *LexDC = D->getLexicalDeclContext(); 1820 if (!AssociatedClasses.count(cast<CXXRecordDecl>(LexDC))) 1821 continue; 1822 } 1823 1824 if (isa<UsingShadowDecl>(D)) 1825 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1826 1827 if (isa<FunctionDecl>(D)) { 1828 if (Operator && 1829 !IsAcceptableNonMemberOperatorCandidate(cast<FunctionDecl>(D), 1830 T1, T2, Context)) 1831 continue; 1832 } else if (!isa<FunctionTemplateDecl>(D)) 1833 continue; 1834 1835 Result.insert(D); 1836 } 1837 } 1838} 1839 1840//---------------------------------------------------------------------------- 1841// Search for all visible declarations. 1842//---------------------------------------------------------------------------- 1843VisibleDeclConsumer::~VisibleDeclConsumer() { } 1844 1845namespace { 1846 1847class ShadowContextRAII; 1848 1849class VisibleDeclsRecord { 1850public: 1851 /// \brief An entry in the shadow map, which is optimized to store a 1852 /// single declaration (the common case) but can also store a list 1853 /// of declarations. 1854 class ShadowMapEntry { 1855 typedef llvm::SmallVector<NamedDecl *, 4> DeclVector; 1856 1857 /// \brief Contains either the solitary NamedDecl * or a vector 1858 /// of declarations. 1859 llvm::PointerUnion<NamedDecl *, DeclVector*> DeclOrVector; 1860 1861 public: 1862 ShadowMapEntry() : DeclOrVector() { } 1863 1864 void Add(NamedDecl *ND); 1865 void Destroy(); 1866 1867 // Iteration. 1868 typedef NamedDecl **iterator; 1869 iterator begin(); 1870 iterator end(); 1871 }; 1872 1873private: 1874 /// \brief A mapping from declaration names to the declarations that have 1875 /// this name within a particular scope. 1876 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap; 1877 1878 /// \brief A list of shadow maps, which is used to model name hiding. 1879 std::list<ShadowMap> ShadowMaps; 1880 1881 /// \brief The declaration contexts we have already visited. 1882 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts; 1883 1884 friend class ShadowContextRAII; 1885 1886public: 1887 /// \brief Determine whether we have already visited this context 1888 /// (and, if not, note that we are going to visit that context now). 1889 bool visitedContext(DeclContext *Ctx) { 1890 return !VisitedContexts.insert(Ctx); 1891 } 1892 1893 /// \brief Determine whether the given declaration is hidden in the 1894 /// current scope. 1895 /// 1896 /// \returns the declaration that hides the given declaration, or 1897 /// NULL if no such declaration exists. 1898 NamedDecl *checkHidden(NamedDecl *ND); 1899 1900 /// \brief Add a declaration to the current shadow map. 1901 void add(NamedDecl *ND) { ShadowMaps.back()[ND->getDeclName()].Add(ND); } 1902}; 1903 1904/// \brief RAII object that records when we've entered a shadow context. 1905class ShadowContextRAII { 1906 VisibleDeclsRecord &Visible; 1907 1908 typedef VisibleDeclsRecord::ShadowMap ShadowMap; 1909 1910public: 1911 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) { 1912 Visible.ShadowMaps.push_back(ShadowMap()); 1913 } 1914 1915 ~ShadowContextRAII() { 1916 for (ShadowMap::iterator E = Visible.ShadowMaps.back().begin(), 1917 EEnd = Visible.ShadowMaps.back().end(); 1918 E != EEnd; 1919 ++E) 1920 E->second.Destroy(); 1921 1922 Visible.ShadowMaps.pop_back(); 1923 } 1924}; 1925 1926} // end anonymous namespace 1927 1928void VisibleDeclsRecord::ShadowMapEntry::Add(NamedDecl *ND) { 1929 if (DeclOrVector.isNull()) { 1930 // 0 - > 1 elements: just set the single element information. 1931 DeclOrVector = ND; 1932 return; 1933 } 1934 1935 if (NamedDecl *PrevND = DeclOrVector.dyn_cast<NamedDecl *>()) { 1936 // 1 -> 2 elements: create the vector of results and push in the 1937 // existing declaration. 1938 DeclVector *Vec = new DeclVector; 1939 Vec->push_back(PrevND); 1940 DeclOrVector = Vec; 1941 } 1942 1943 // Add the new element to the end of the vector. 1944 DeclOrVector.get<DeclVector*>()->push_back(ND); 1945} 1946 1947void VisibleDeclsRecord::ShadowMapEntry::Destroy() { 1948 if (DeclVector *Vec = DeclOrVector.dyn_cast<DeclVector *>()) { 1949 delete Vec; 1950 DeclOrVector = ((NamedDecl *)0); 1951 } 1952} 1953 1954VisibleDeclsRecord::ShadowMapEntry::iterator 1955VisibleDeclsRecord::ShadowMapEntry::begin() { 1956 if (DeclOrVector.isNull()) 1957 return 0; 1958 1959 if (DeclOrVector.dyn_cast<NamedDecl *>()) 1960 return &reinterpret_cast<NamedDecl*&>(DeclOrVector); 1961 1962 return DeclOrVector.get<DeclVector *>()->begin(); 1963} 1964 1965VisibleDeclsRecord::ShadowMapEntry::iterator 1966VisibleDeclsRecord::ShadowMapEntry::end() { 1967 if (DeclOrVector.isNull()) 1968 return 0; 1969 1970 if (DeclOrVector.dyn_cast<NamedDecl *>()) 1971 return &reinterpret_cast<NamedDecl*&>(DeclOrVector) + 1; 1972 1973 return DeclOrVector.get<DeclVector *>()->end(); 1974} 1975 1976NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) { 1977 // Look through using declarations. 1978 ND = ND->getUnderlyingDecl(); 1979 1980 unsigned IDNS = ND->getIdentifierNamespace(); 1981 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin(); 1982 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend(); 1983 SM != SMEnd; ++SM) { 1984 ShadowMap::iterator Pos = SM->find(ND->getDeclName()); 1985 if (Pos == SM->end()) 1986 continue; 1987 1988 for (ShadowMapEntry::iterator I = Pos->second.begin(), 1989 IEnd = Pos->second.end(); 1990 I != IEnd; ++I) { 1991 // A tag declaration does not hide a non-tag declaration. 1992 if ((*I)->getIdentifierNamespace() == Decl::IDNS_Tag && 1993 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary | 1994 Decl::IDNS_ObjCProtocol))) 1995 continue; 1996 1997 // Protocols are in distinct namespaces from everything else. 1998 if ((((*I)->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol) 1999 || (IDNS & Decl::IDNS_ObjCProtocol)) && 2000 (*I)->getIdentifierNamespace() != IDNS) 2001 continue; 2002 2003 // Functions and function templates in the same scope overload 2004 // rather than hide. FIXME: Look for hiding based on function 2005 // signatures! 2006 if ((*I)->isFunctionOrFunctionTemplate() && 2007 ND->isFunctionOrFunctionTemplate() && 2008 SM == ShadowMaps.rbegin()) 2009 continue; 2010 2011 // We've found a declaration that hides this one. 2012 return *I; 2013 } 2014 } 2015 2016 return 0; 2017} 2018 2019static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result, 2020 bool QualifiedNameLookup, 2021 bool InBaseClass, 2022 VisibleDeclConsumer &Consumer, 2023 VisibleDeclsRecord &Visited) { 2024 // Make sure we don't visit the same context twice. 2025 if (Visited.visitedContext(Ctx->getPrimaryContext())) 2026 return; 2027 2028 // Enumerate all of the results in this context. 2029 for (DeclContext *CurCtx = Ctx->getPrimaryContext(); CurCtx; 2030 CurCtx = CurCtx->getNextContext()) { 2031 for (DeclContext::decl_iterator D = CurCtx->decls_begin(), 2032 DEnd = CurCtx->decls_end(); 2033 D != DEnd; ++D) { 2034 if (NamedDecl *ND = dyn_cast<NamedDecl>(*D)) 2035 if (Result.isAcceptableDecl(ND)) { 2036 Consumer.FoundDecl(ND, Visited.checkHidden(ND), InBaseClass); 2037 Visited.add(ND); 2038 } 2039 2040 // Visit transparent contexts inside this context. 2041 if (DeclContext *InnerCtx = dyn_cast<DeclContext>(*D)) { 2042 if (InnerCtx->isTransparentContext()) 2043 LookupVisibleDecls(InnerCtx, Result, QualifiedNameLookup, InBaseClass, 2044 Consumer, Visited); 2045 } 2046 } 2047 } 2048 2049 // Traverse using directives for qualified name lookup. 2050 if (QualifiedNameLookup) { 2051 ShadowContextRAII Shadow(Visited); 2052 DeclContext::udir_iterator I, E; 2053 for (llvm::tie(I, E) = Ctx->getUsingDirectives(); I != E; ++I) { 2054 LookupVisibleDecls((*I)->getNominatedNamespace(), Result, 2055 QualifiedNameLookup, InBaseClass, Consumer, Visited); 2056 } 2057 } 2058 2059 // Traverse the contexts of inherited C++ classes. 2060 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) { 2061 for (CXXRecordDecl::base_class_iterator B = Record->bases_begin(), 2062 BEnd = Record->bases_end(); 2063 B != BEnd; ++B) { 2064 QualType BaseType = B->getType(); 2065 2066 // Don't look into dependent bases, because name lookup can't look 2067 // there anyway. 2068 if (BaseType->isDependentType()) 2069 continue; 2070 2071 const RecordType *Record = BaseType->getAs<RecordType>(); 2072 if (!Record) 2073 continue; 2074 2075 // FIXME: It would be nice to be able to determine whether referencing 2076 // a particular member would be ambiguous. For example, given 2077 // 2078 // struct A { int member; }; 2079 // struct B { int member; }; 2080 // struct C : A, B { }; 2081 // 2082 // void f(C *c) { c->### } 2083 // 2084 // accessing 'member' would result in an ambiguity. However, we 2085 // could be smart enough to qualify the member with the base 2086 // class, e.g., 2087 // 2088 // c->B::member 2089 // 2090 // or 2091 // 2092 // c->A::member 2093 2094 // Find results in this base class (and its bases). 2095 ShadowContextRAII Shadow(Visited); 2096 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup, 2097 true, Consumer, Visited); 2098 } 2099 } 2100 2101 // Traverse the contexts of Objective-C classes. 2102 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) { 2103 // Traverse categories. 2104 for (ObjCCategoryDecl *Category = IFace->getCategoryList(); 2105 Category; Category = Category->getNextClassCategory()) { 2106 ShadowContextRAII Shadow(Visited); 2107 LookupVisibleDecls(Category, Result, QualifiedNameLookup, false, 2108 Consumer, Visited); 2109 } 2110 2111 // Traverse protocols. 2112 for (ObjCInterfaceDecl::protocol_iterator I = IFace->protocol_begin(), 2113 E = IFace->protocol_end(); I != E; ++I) { 2114 ShadowContextRAII Shadow(Visited); 2115 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2116 Visited); 2117 } 2118 2119 // Traverse the superclass. 2120 if (IFace->getSuperClass()) { 2121 ShadowContextRAII Shadow(Visited); 2122 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup, 2123 true, Consumer, Visited); 2124 } 2125 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) { 2126 for (ObjCProtocolDecl::protocol_iterator I = Protocol->protocol_begin(), 2127 E = Protocol->protocol_end(); I != E; ++I) { 2128 ShadowContextRAII Shadow(Visited); 2129 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2130 Visited); 2131 } 2132 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) { 2133 for (ObjCCategoryDecl::protocol_iterator I = Category->protocol_begin(), 2134 E = Category->protocol_end(); I != E; ++I) { 2135 ShadowContextRAII Shadow(Visited); 2136 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2137 Visited); 2138 } 2139 } 2140} 2141 2142static void LookupVisibleDecls(Scope *S, LookupResult &Result, 2143 UnqualUsingDirectiveSet &UDirs, 2144 VisibleDeclConsumer &Consumer, 2145 VisibleDeclsRecord &Visited) { 2146 if (!S) 2147 return; 2148 2149 if (!S->getEntity() || !S->getParent() || 2150 ((DeclContext *)S->getEntity())->isFunctionOrMethod()) { 2151 // Walk through the declarations in this Scope. 2152 for (Scope::decl_iterator D = S->decl_begin(), DEnd = S->decl_end(); 2153 D != DEnd; ++D) { 2154 if (NamedDecl *ND = dyn_cast<NamedDecl>((Decl *)((*D).get()))) 2155 if (Result.isAcceptableDecl(ND)) { 2156 Consumer.FoundDecl(ND, Visited.checkHidden(ND), false); 2157 Visited.add(ND); 2158 } 2159 } 2160 } 2161 2162 DeclContext *Entity = 0; 2163 if (S->getEntity()) { 2164 // Look into this scope's declaration context, along with any of its 2165 // parent lookup contexts (e.g., enclosing classes), up to the point 2166 // where we hit the context stored in the next outer scope. 2167 Entity = (DeclContext *)S->getEntity(); 2168 DeclContext *OuterCtx = findOuterContext(S); 2169 2170 for (DeclContext *Ctx = Entity; Ctx && Ctx->getPrimaryContext() != OuterCtx; 2171 Ctx = Ctx->getLookupParent()) { 2172 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 2173 if (Method->isInstanceMethod()) { 2174 // For instance methods, look for ivars in the method's interface. 2175 LookupResult IvarResult(Result.getSema(), Result.getLookupName(), 2176 Result.getNameLoc(), Sema::LookupMemberName); 2177 ObjCInterfaceDecl *IFace = Method->getClassInterface(); 2178 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false, 2179 /*InBaseClass=*/false, Consumer, Visited); 2180 } 2181 2182 // We've already performed all of the name lookup that we need 2183 // to for Objective-C methods; the next context will be the 2184 // outer scope. 2185 break; 2186 } 2187 2188 if (Ctx->isFunctionOrMethod()) 2189 continue; 2190 2191 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false, 2192 /*InBaseClass=*/false, Consumer, Visited); 2193 } 2194 } else if (!S->getParent()) { 2195 // Look into the translation unit scope. We walk through the translation 2196 // unit's declaration context, because the Scope itself won't have all of 2197 // the declarations if we loaded a precompiled header. 2198 // FIXME: We would like the translation unit's Scope object to point to the 2199 // translation unit, so we don't need this special "if" branch. However, 2200 // doing so would force the normal C++ name-lookup code to look into the 2201 // translation unit decl when the IdentifierInfo chains would suffice. 2202 // Once we fix that problem (which is part of a more general "don't look 2203 // in DeclContexts unless we have to" optimization), we can eliminate this. 2204 Entity = Result.getSema().Context.getTranslationUnitDecl(); 2205 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false, 2206 /*InBaseClass=*/false, Consumer, Visited); 2207 } 2208 2209 if (Entity) { 2210 // Lookup visible declarations in any namespaces found by using 2211 // directives. 2212 UnqualUsingDirectiveSet::const_iterator UI, UEnd; 2213 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(Entity); 2214 for (; UI != UEnd; ++UI) 2215 LookupVisibleDecls(const_cast<DeclContext *>(UI->getNominatedNamespace()), 2216 Result, /*QualifiedNameLookup=*/false, 2217 /*InBaseClass=*/false, Consumer, Visited); 2218 } 2219 2220 // Lookup names in the parent scope. 2221 ShadowContextRAII Shadow(Visited); 2222 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited); 2223} 2224 2225void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind, 2226 VisibleDeclConsumer &Consumer) { 2227 // Determine the set of using directives available during 2228 // unqualified name lookup. 2229 Scope *Initial = S; 2230 UnqualUsingDirectiveSet UDirs; 2231 if (getLangOptions().CPlusPlus) { 2232 // Find the first namespace or translation-unit scope. 2233 while (S && !isNamespaceOrTranslationUnitScope(S)) 2234 S = S->getParent(); 2235 2236 UDirs.visitScopeChain(Initial, S); 2237 } 2238 UDirs.done(); 2239 2240 // Look for visible declarations. 2241 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2242 VisibleDeclsRecord Visited; 2243 ShadowContextRAII Shadow(Visited); 2244 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited); 2245} 2246 2247void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind, 2248 VisibleDeclConsumer &Consumer) { 2249 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2250 VisibleDeclsRecord Visited; 2251 ShadowContextRAII Shadow(Visited); 2252 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true, 2253 /*InBaseClass=*/false, Consumer, Visited); 2254} 2255 2256//---------------------------------------------------------------------------- 2257// Typo correction 2258//---------------------------------------------------------------------------- 2259 2260namespace { 2261class TypoCorrectionConsumer : public VisibleDeclConsumer { 2262 /// \brief The name written that is a typo in the source. 2263 llvm::StringRef Typo; 2264 2265 /// \brief The results found that have the smallest edit distance 2266 /// found (so far) with the typo name. 2267 llvm::SmallVector<NamedDecl *, 4> BestResults; 2268 2269 /// \brief The best edit distance found so far. 2270 unsigned BestEditDistance; 2271 2272public: 2273 explicit TypoCorrectionConsumer(IdentifierInfo *Typo) 2274 : Typo(Typo->getName()) { } 2275 2276 virtual void FoundDecl(NamedDecl *ND, NamedDecl *Hiding, bool InBaseClass); 2277 2278 typedef llvm::SmallVector<NamedDecl *, 4>::const_iterator iterator; 2279 iterator begin() const { return BestResults.begin(); } 2280 iterator end() const { return BestResults.end(); } 2281 bool empty() const { return BestResults.empty(); } 2282 2283 unsigned getBestEditDistance() const { return BestEditDistance; } 2284}; 2285 2286} 2287 2288void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding, 2289 bool InBaseClass) { 2290 // Don't consider hidden names for typo correction. 2291 if (Hiding) 2292 return; 2293 2294 // Only consider entities with identifiers for names, ignoring 2295 // special names (constructors, overloaded operators, selectors, 2296 // etc.). 2297 IdentifierInfo *Name = ND->getIdentifier(); 2298 if (!Name) 2299 return; 2300 2301 // Compute the edit distance between the typo and the name of this 2302 // entity. If this edit distance is not worse than the best edit 2303 // distance we've seen so far, add it to the list of results. 2304 unsigned ED = Typo.edit_distance(Name->getName()); 2305 if (!BestResults.empty()) { 2306 if (ED < BestEditDistance) { 2307 // This result is better than any we've seen before; clear out 2308 // the previous results. 2309 BestResults.clear(); 2310 BestEditDistance = ED; 2311 } else if (ED > BestEditDistance) { 2312 // This result is worse than the best results we've seen so far; 2313 // ignore it. 2314 return; 2315 } 2316 } else 2317 BestEditDistance = ED; 2318 2319 BestResults.push_back(ND); 2320} 2321 2322/// \brief Try to "correct" a typo in the source code by finding 2323/// visible declarations whose names are similar to the name that was 2324/// present in the source code. 2325/// 2326/// \param Res the \c LookupResult structure that contains the name 2327/// that was present in the source code along with the name-lookup 2328/// criteria used to search for the name. On success, this structure 2329/// will contain the results of name lookup. 2330/// 2331/// \param S the scope in which name lookup occurs. 2332/// 2333/// \param SS the nested-name-specifier that precedes the name we're 2334/// looking for, if present. 2335/// 2336/// \param MemberContext if non-NULL, the context in which to look for 2337/// a member access expression. 2338/// 2339/// \param EnteringContext whether we're entering the context described by 2340/// the nested-name-specifier SS. 2341/// 2342/// \param OPT when non-NULL, the search for visible declarations will 2343/// also walk the protocols in the qualified interfaces of \p OPT. 2344/// 2345/// \returns true if the typo was corrected, in which case the \p Res 2346/// structure will contain the results of name lookup for the 2347/// corrected name. Otherwise, returns false. 2348bool Sema::CorrectTypo(LookupResult &Res, Scope *S, const CXXScopeSpec *SS, 2349 DeclContext *MemberContext, bool EnteringContext, 2350 const ObjCObjectPointerType *OPT) { 2351 2352 if (Diags.hasFatalErrorOccurred()) 2353 return false; 2354 2355 // We only attempt to correct typos for identifiers. 2356 IdentifierInfo *Typo = Res.getLookupName().getAsIdentifierInfo(); 2357 if (!Typo) 2358 return false; 2359 2360 // If the scope specifier itself was invalid, don't try to correct 2361 // typos. 2362 if (SS && SS->isInvalid()) 2363 return false; 2364 2365 // Never try to correct typos during template deduction or 2366 // instantiation. 2367 if (!ActiveTemplateInstantiations.empty()) 2368 return false; 2369 2370 TypoCorrectionConsumer Consumer(Typo); 2371 if (MemberContext) { 2372 LookupVisibleDecls(MemberContext, Res.getLookupKind(), Consumer); 2373 2374 // Look in qualified interfaces. 2375 if (OPT) { 2376 for (ObjCObjectPointerType::qual_iterator 2377 I = OPT->qual_begin(), E = OPT->qual_end(); 2378 I != E; ++I) 2379 LookupVisibleDecls(*I, Res.getLookupKind(), Consumer); 2380 } 2381 } else if (SS && SS->isSet()) { 2382 DeclContext *DC = computeDeclContext(*SS, EnteringContext); 2383 if (!DC) 2384 return false; 2385 2386 LookupVisibleDecls(DC, Res.getLookupKind(), Consumer); 2387 } else { 2388 LookupVisibleDecls(S, Res.getLookupKind(), Consumer); 2389 } 2390 2391 if (Consumer.empty()) 2392 return false; 2393 2394 // Only allow a single, closest name in the result set (it's okay to 2395 // have overloads of that name, though). 2396 TypoCorrectionConsumer::iterator I = Consumer.begin(); 2397 DeclarationName BestName = (*I)->getDeclName(); 2398 2399 // If we've found an Objective-C ivar or property, don't perform 2400 // name lookup again; we'll just return the result directly. 2401 NamedDecl *FoundBest = 0; 2402 if (isa<ObjCIvarDecl>(*I) || isa<ObjCPropertyDecl>(*I)) 2403 FoundBest = *I; 2404 ++I; 2405 for(TypoCorrectionConsumer::iterator IEnd = Consumer.end(); I != IEnd; ++I) { 2406 if (BestName != (*I)->getDeclName()) 2407 return false; 2408 2409 // FIXME: If there are both ivars and properties of the same name, 2410 // don't return both because the callee can't handle two 2411 // results. We really need to separate ivar lookup from property 2412 // lookup to avoid this problem. 2413 FoundBest = 0; 2414 } 2415 2416 // BestName is the closest viable name to what the user 2417 // typed. However, to make sure that we don't pick something that's 2418 // way off, make sure that the user typed at least 3 characters for 2419 // each correction. 2420 unsigned ED = Consumer.getBestEditDistance(); 2421 if (ED == 0 || (BestName.getAsIdentifierInfo()->getName().size() / ED) < 3) 2422 return false; 2423 2424 // Perform name lookup again with the name we chose, and declare 2425 // success if we found something that was not ambiguous. 2426 Res.clear(); 2427 Res.setLookupName(BestName); 2428 2429 // If we found an ivar or property, add that result; no further 2430 // lookup is required. 2431 if (FoundBest) 2432 Res.addDecl(FoundBest); 2433 // If we're looking into the context of a member, perform qualified 2434 // name lookup on the best name. 2435 else if (MemberContext) 2436 LookupQualifiedName(Res, MemberContext); 2437 // Perform lookup as if we had just parsed the best name. 2438 else 2439 LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false, 2440 EnteringContext); 2441 2442 if (Res.isAmbiguous()) { 2443 Res.suppressDiagnostics(); 2444 return false; 2445 } 2446 2447 return Res.getResultKind() != LookupResult::NotFound; 2448} 2449