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 "clang/Sema/Sema.h" 15 #include "clang/Sema/SemaInternal.h" 16 #include "clang/Sema/Lookup.h" 17 #include "clang/Sema/Overload.h" 18 #include "clang/Sema/DeclSpec.h" 19 #include "clang/Sema/Scope.h" 20 #include "clang/Sema/ScopeInfo.h" 21 #include "clang/Sema/TemplateDeduction.h" 22 #include "clang/Sema/ExternalSemaSource.h" 23 #include "clang/Sema/TypoCorrection.h" 24 #include "clang/AST/ASTContext.h" 25 #include "clang/AST/CXXInheritance.h" 26 #include "clang/AST/Decl.h" 27 #include "clang/AST/DeclCXX.h" 28 #include "clang/AST/DeclObjC.h" 29 #include "clang/AST/DeclTemplate.h" 30 #include "clang/AST/Expr.h" 31 #include "clang/AST/ExprCXX.h" 32 #include "clang/Basic/Builtins.h" 33 #include "clang/Basic/LangOptions.h" 34 #include "llvm/ADT/DenseSet.h" 35 #include "llvm/ADT/STLExtras.h" 36 #include "llvm/ADT/SmallPtrSet.h" 37 #include "llvm/ADT/StringMap.h" 38 #include "llvm/ADT/TinyPtrVector.h" 39 #include "llvm/Support/ErrorHandling.h" 40 #include <limits> 41 #include <list> 42 #include <set> 43 #include <vector> 44 #include <iterator> 45 #include <utility> 46 #include <algorithm> 47 #include <map> 48 49 using namespace clang; 50 using namespace sema; 51 52 namespace { 53 class UnqualUsingEntry { 54 const DeclContext *Nominated; 55 const DeclContext *CommonAncestor; 56 57 public: 58 UnqualUsingEntry(const DeclContext *Nominated, 59 const DeclContext *CommonAncestor) 60 : Nominated(Nominated), CommonAncestor(CommonAncestor) { 61 } 62 63 const DeclContext *getCommonAncestor() const { 64 return CommonAncestor; 65 } 66 67 const DeclContext *getNominatedNamespace() const { 68 return Nominated; 69 } 70 71 // Sort by the pointer value of the common ancestor. 72 struct Comparator { 73 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) { 74 return L.getCommonAncestor() < R.getCommonAncestor(); 75 } 76 77 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) { 78 return E.getCommonAncestor() < DC; 79 } 80 81 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) { 82 return DC < E.getCommonAncestor(); 83 } 84 }; 85 }; 86 87 /// A collection of using directives, as used by C++ unqualified 88 /// lookup. 89 class UnqualUsingDirectiveSet { 90 typedef SmallVector<UnqualUsingEntry, 8> ListTy; 91 92 ListTy list; 93 llvm::SmallPtrSet<DeclContext*, 8> visited; 94 95 public: 96 UnqualUsingDirectiveSet() {} 97 98 void visitScopeChain(Scope *S, Scope *InnermostFileScope) { 99 // C++ [namespace.udir]p1: 100 // During unqualified name lookup, the names appear as if they 101 // were declared in the nearest enclosing namespace which contains 102 // both the using-directive and the nominated namespace. 103 DeclContext *InnermostFileDC 104 = static_cast<DeclContext*>(InnermostFileScope->getEntity()); 105 assert(InnermostFileDC && InnermostFileDC->isFileContext()); 106 107 for (; S; S = S->getParent()) { 108 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) { 109 DeclContext *EffectiveDC = (Ctx->isFileContext() ? Ctx : InnermostFileDC); 110 visit(Ctx, EffectiveDC); 111 } else { 112 Scope::udir_iterator I = S->using_directives_begin(), 113 End = S->using_directives_end(); 114 115 for (; I != End; ++I) 116 visit(*I, InnermostFileDC); 117 } 118 } 119 } 120 121 // Visits a context and collect all of its using directives 122 // recursively. Treats all using directives as if they were 123 // declared in the context. 124 // 125 // A given context is only every visited once, so it is important 126 // that contexts be visited from the inside out in order to get 127 // the effective DCs right. 128 void visit(DeclContext *DC, DeclContext *EffectiveDC) { 129 if (!visited.insert(DC)) 130 return; 131 132 addUsingDirectives(DC, EffectiveDC); 133 } 134 135 // Visits a using directive and collects all of its using 136 // directives recursively. Treats all using directives as if they 137 // were declared in the effective DC. 138 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 139 DeclContext *NS = UD->getNominatedNamespace(); 140 if (!visited.insert(NS)) 141 return; 142 143 addUsingDirective(UD, EffectiveDC); 144 addUsingDirectives(NS, EffectiveDC); 145 } 146 147 // Adds all the using directives in a context (and those nominated 148 // by its using directives, transitively) as if they appeared in 149 // the given effective context. 150 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) { 151 SmallVector<DeclContext*,4> queue; 152 while (true) { 153 DeclContext::udir_iterator I, End; 154 for (llvm::tie(I, End) = DC->getUsingDirectives(); I != End; ++I) { 155 UsingDirectiveDecl *UD = *I; 156 DeclContext *NS = UD->getNominatedNamespace(); 157 if (visited.insert(NS)) { 158 addUsingDirective(UD, EffectiveDC); 159 queue.push_back(NS); 160 } 161 } 162 163 if (queue.empty()) 164 return; 165 166 DC = queue.back(); 167 queue.pop_back(); 168 } 169 } 170 171 // Add a using directive as if it had been declared in the given 172 // context. This helps implement C++ [namespace.udir]p3: 173 // The using-directive is transitive: if a scope contains a 174 // using-directive that nominates a second namespace that itself 175 // contains using-directives, the effect is as if the 176 // using-directives from the second namespace also appeared in 177 // the first. 178 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 179 // Find the common ancestor between the effective context and 180 // the nominated namespace. 181 DeclContext *Common = UD->getNominatedNamespace(); 182 while (!Common->Encloses(EffectiveDC)) 183 Common = Common->getParent(); 184 Common = Common->getPrimaryContext(); 185 186 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common)); 187 } 188 189 void done() { 190 std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator()); 191 } 192 193 typedef ListTy::const_iterator const_iterator; 194 195 const_iterator begin() const { return list.begin(); } 196 const_iterator end() const { return list.end(); } 197 198 std::pair<const_iterator,const_iterator> 199 getNamespacesFor(DeclContext *DC) const { 200 return std::equal_range(begin(), end(), DC->getPrimaryContext(), 201 UnqualUsingEntry::Comparator()); 202 } 203 }; 204 } 205 206 // Retrieve the set of identifier namespaces that correspond to a 207 // specific kind of name lookup. 208 static inline unsigned getIDNS(Sema::LookupNameKind NameKind, 209 bool CPlusPlus, 210 bool Redeclaration) { 211 unsigned IDNS = 0; 212 switch (NameKind) { 213 case Sema::LookupObjCImplicitSelfParam: 214 case Sema::LookupOrdinaryName: 215 case Sema::LookupRedeclarationWithLinkage: 216 IDNS = Decl::IDNS_Ordinary; 217 if (CPlusPlus) { 218 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace; 219 if (Redeclaration) 220 IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend; 221 } 222 break; 223 224 case Sema::LookupOperatorName: 225 // Operator lookup is its own crazy thing; it is not the same 226 // as (e.g.) looking up an operator name for redeclaration. 227 assert(!Redeclaration && "cannot do redeclaration operator lookup"); 228 IDNS = Decl::IDNS_NonMemberOperator; 229 break; 230 231 case Sema::LookupTagName: 232 if (CPlusPlus) { 233 IDNS = Decl::IDNS_Type; 234 235 // When looking for a redeclaration of a tag name, we add: 236 // 1) TagFriend to find undeclared friend decls 237 // 2) Namespace because they can't "overload" with tag decls. 238 // 3) Tag because it includes class templates, which can't 239 // "overload" with tag decls. 240 if (Redeclaration) 241 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace; 242 } else { 243 IDNS = Decl::IDNS_Tag; 244 } 245 break; 246 case Sema::LookupLabel: 247 IDNS = Decl::IDNS_Label; 248 break; 249 250 case Sema::LookupMemberName: 251 IDNS = Decl::IDNS_Member; 252 if (CPlusPlus) 253 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary; 254 break; 255 256 case Sema::LookupNestedNameSpecifierName: 257 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace; 258 break; 259 260 case Sema::LookupNamespaceName: 261 IDNS = Decl::IDNS_Namespace; 262 break; 263 264 case Sema::LookupUsingDeclName: 265 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag 266 | Decl::IDNS_Member | Decl::IDNS_Using; 267 break; 268 269 case Sema::LookupObjCProtocolName: 270 IDNS = Decl::IDNS_ObjCProtocol; 271 break; 272 273 case Sema::LookupAnyName: 274 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member 275 | Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol 276 | Decl::IDNS_Type; 277 break; 278 } 279 return IDNS; 280 } 281 282 void LookupResult::configure() { 283 IDNS = getIDNS(LookupKind, SemaRef.getLangOptions().CPlusPlus, 284 isForRedeclaration()); 285 286 // If we're looking for one of the allocation or deallocation 287 // operators, make sure that the implicitly-declared new and delete 288 // operators can be found. 289 if (!isForRedeclaration()) { 290 switch (NameInfo.getName().getCXXOverloadedOperator()) { 291 case OO_New: 292 case OO_Delete: 293 case OO_Array_New: 294 case OO_Array_Delete: 295 SemaRef.DeclareGlobalNewDelete(); 296 break; 297 298 default: 299 break; 300 } 301 } 302 } 303 304 void LookupResult::sanity() const { 305 assert(ResultKind != NotFound || Decls.size() == 0); 306 assert(ResultKind != Found || Decls.size() == 1); 307 assert(ResultKind != FoundOverloaded || Decls.size() > 1 || 308 (Decls.size() == 1 && 309 isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl()))); 310 assert(ResultKind != FoundUnresolvedValue || sanityCheckUnresolved()); 311 assert(ResultKind != Ambiguous || Decls.size() > 1 || 312 (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects || 313 Ambiguity == AmbiguousBaseSubobjectTypes))); 314 assert((Paths != NULL) == (ResultKind == Ambiguous && 315 (Ambiguity == AmbiguousBaseSubobjectTypes || 316 Ambiguity == AmbiguousBaseSubobjects))); 317 } 318 319 // Necessary because CXXBasePaths is not complete in Sema.h 320 void LookupResult::deletePaths(CXXBasePaths *Paths) { 321 delete Paths; 322 } 323 324 /// Resolves the result kind of this lookup. 325 void LookupResult::resolveKind() { 326 unsigned N = Decls.size(); 327 328 // Fast case: no possible ambiguity. 329 if (N == 0) { 330 assert(ResultKind == NotFound || ResultKind == NotFoundInCurrentInstantiation); 331 return; 332 } 333 334 // If there's a single decl, we need to examine it to decide what 335 // kind of lookup this is. 336 if (N == 1) { 337 NamedDecl *D = (*Decls.begin())->getUnderlyingDecl(); 338 if (isa<FunctionTemplateDecl>(D)) 339 ResultKind = FoundOverloaded; 340 else if (isa<UnresolvedUsingValueDecl>(D)) 341 ResultKind = FoundUnresolvedValue; 342 return; 343 } 344 345 // Don't do any extra resolution if we've already resolved as ambiguous. 346 if (ResultKind == Ambiguous) return; 347 348 llvm::SmallPtrSet<NamedDecl*, 16> Unique; 349 llvm::SmallPtrSet<QualType, 16> UniqueTypes; 350 351 bool Ambiguous = false; 352 bool HasTag = false, HasFunction = false, HasNonFunction = false; 353 bool HasFunctionTemplate = false, HasUnresolved = false; 354 355 unsigned UniqueTagIndex = 0; 356 357 unsigned I = 0; 358 while (I < N) { 359 NamedDecl *D = Decls[I]->getUnderlyingDecl(); 360 D = cast<NamedDecl>(D->getCanonicalDecl()); 361 362 // Redeclarations of types via typedef can occur both within a scope 363 // and, through using declarations and directives, across scopes. There is 364 // no ambiguity if they all refer to the same type, so unique based on the 365 // canonical type. 366 if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) { 367 if (!TD->getDeclContext()->isRecord()) { 368 QualType T = SemaRef.Context.getTypeDeclType(TD); 369 if (!UniqueTypes.insert(SemaRef.Context.getCanonicalType(T))) { 370 // The type is not unique; pull something off the back and continue 371 // at this index. 372 Decls[I] = Decls[--N]; 373 continue; 374 } 375 } 376 } 377 378 if (!Unique.insert(D)) { 379 // If it's not unique, pull something off the back (and 380 // continue at this index). 381 Decls[I] = Decls[--N]; 382 continue; 383 } 384 385 // Otherwise, do some decl type analysis and then continue. 386 387 if (isa<UnresolvedUsingValueDecl>(D)) { 388 HasUnresolved = true; 389 } else if (isa<TagDecl>(D)) { 390 if (HasTag) 391 Ambiguous = true; 392 UniqueTagIndex = I; 393 HasTag = true; 394 } else if (isa<FunctionTemplateDecl>(D)) { 395 HasFunction = true; 396 HasFunctionTemplate = true; 397 } else if (isa<FunctionDecl>(D)) { 398 HasFunction = true; 399 } else { 400 if (HasNonFunction) 401 Ambiguous = true; 402 HasNonFunction = true; 403 } 404 I++; 405 } 406 407 // C++ [basic.scope.hiding]p2: 408 // A class name or enumeration name can be hidden by the name of 409 // an object, function, or enumerator declared in the same 410 // scope. If a class or enumeration name and an object, function, 411 // or enumerator are declared in the same scope (in any order) 412 // with the same name, the class or enumeration name is hidden 413 // wherever the object, function, or enumerator name is visible. 414 // But it's still an error if there are distinct tag types found, 415 // even if they're not visible. (ref?) 416 if (HideTags && HasTag && !Ambiguous && 417 (HasFunction || HasNonFunction || HasUnresolved)) { 418 if (Decls[UniqueTagIndex]->getDeclContext()->getRedeclContext()->Equals( 419 Decls[UniqueTagIndex? 0 : N-1]->getDeclContext()->getRedeclContext())) 420 Decls[UniqueTagIndex] = Decls[--N]; 421 else 422 Ambiguous = true; 423 } 424 425 Decls.set_size(N); 426 427 if (HasNonFunction && (HasFunction || HasUnresolved)) 428 Ambiguous = true; 429 430 if (Ambiguous) 431 setAmbiguous(LookupResult::AmbiguousReference); 432 else if (HasUnresolved) 433 ResultKind = LookupResult::FoundUnresolvedValue; 434 else if (N > 1 || HasFunctionTemplate) 435 ResultKind = LookupResult::FoundOverloaded; 436 else 437 ResultKind = LookupResult::Found; 438 } 439 440 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) { 441 CXXBasePaths::const_paths_iterator I, E; 442 DeclContext::lookup_iterator DI, DE; 443 for (I = P.begin(), E = P.end(); I != E; ++I) 444 for (llvm::tie(DI,DE) = I->Decls; DI != DE; ++DI) 445 addDecl(*DI); 446 } 447 448 void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) { 449 Paths = new CXXBasePaths; 450 Paths->swap(P); 451 addDeclsFromBasePaths(*Paths); 452 resolveKind(); 453 setAmbiguous(AmbiguousBaseSubobjects); 454 } 455 456 void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) { 457 Paths = new CXXBasePaths; 458 Paths->swap(P); 459 addDeclsFromBasePaths(*Paths); 460 resolveKind(); 461 setAmbiguous(AmbiguousBaseSubobjectTypes); 462 } 463 464 void LookupResult::print(raw_ostream &Out) { 465 Out << Decls.size() << " result(s)"; 466 if (isAmbiguous()) Out << ", ambiguous"; 467 if (Paths) Out << ", base paths present"; 468 469 for (iterator I = begin(), E = end(); I != E; ++I) { 470 Out << "\n"; 471 (*I)->print(Out, 2); 472 } 473 } 474 475 /// \brief Lookup a builtin function, when name lookup would otherwise 476 /// fail. 477 static bool LookupBuiltin(Sema &S, LookupResult &R) { 478 Sema::LookupNameKind NameKind = R.getLookupKind(); 479 480 // If we didn't find a use of this identifier, and if the identifier 481 // corresponds to a compiler builtin, create the decl object for the builtin 482 // now, injecting it into translation unit scope, and return it. 483 if (NameKind == Sema::LookupOrdinaryName || 484 NameKind == Sema::LookupRedeclarationWithLinkage) { 485 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo(); 486 if (II) { 487 // If this is a builtin on this (or all) targets, create the decl. 488 if (unsigned BuiltinID = II->getBuiltinID()) { 489 // In C++, we don't have any predefined library functions like 490 // 'malloc'. Instead, we'll just error. 491 if (S.getLangOptions().CPlusPlus && 492 S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 493 return false; 494 495 if (NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II, 496 BuiltinID, S.TUScope, 497 R.isForRedeclaration(), 498 R.getNameLoc())) { 499 R.addDecl(D); 500 return true; 501 } 502 503 if (R.isForRedeclaration()) { 504 // If we're redeclaring this function anyway, forget that 505 // this was a builtin at all. 506 S.Context.BuiltinInfo.ForgetBuiltin(BuiltinID, S.Context.Idents); 507 } 508 509 return false; 510 } 511 } 512 } 513 514 return false; 515 } 516 517 /// \brief Determine whether we can declare a special member function within 518 /// the class at this point. 519 static bool CanDeclareSpecialMemberFunction(ASTContext &Context, 520 const CXXRecordDecl *Class) { 521 // Don't do it if the class is invalid. 522 if (Class->isInvalidDecl()) 523 return false; 524 525 // We need to have a definition for the class. 526 if (!Class->getDefinition() || Class->isDependentContext()) 527 return false; 528 529 // We can't be in the middle of defining the class. 530 if (const RecordType *RecordTy 531 = Context.getTypeDeclType(Class)->getAs<RecordType>()) 532 return !RecordTy->isBeingDefined(); 533 534 return false; 535 } 536 537 void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) { 538 if (!CanDeclareSpecialMemberFunction(Context, Class)) 539 return; 540 541 // If the default constructor has not yet been declared, do so now. 542 if (Class->needsImplicitDefaultConstructor()) 543 DeclareImplicitDefaultConstructor(Class); 544 545 // If the copy constructor has not yet been declared, do so now. 546 if (!Class->hasDeclaredCopyConstructor()) 547 DeclareImplicitCopyConstructor(Class); 548 549 // If the copy assignment operator has not yet been declared, do so now. 550 if (!Class->hasDeclaredCopyAssignment()) 551 DeclareImplicitCopyAssignment(Class); 552 553 if (getLangOptions().CPlusPlus0x) { 554 // If the move constructor has not yet been declared, do so now. 555 if (Class->needsImplicitMoveConstructor()) 556 DeclareImplicitMoveConstructor(Class); // might not actually do it 557 558 // If the move assignment operator has not yet been declared, do so now. 559 if (Class->needsImplicitMoveAssignment()) 560 DeclareImplicitMoveAssignment(Class); // might not actually do it 561 } 562 563 // If the destructor has not yet been declared, do so now. 564 if (!Class->hasDeclaredDestructor()) 565 DeclareImplicitDestructor(Class); 566 } 567 568 /// \brief Determine whether this is the name of an implicitly-declared 569 /// special member function. 570 static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) { 571 switch (Name.getNameKind()) { 572 case DeclarationName::CXXConstructorName: 573 case DeclarationName::CXXDestructorName: 574 return true; 575 576 case DeclarationName::CXXOperatorName: 577 return Name.getCXXOverloadedOperator() == OO_Equal; 578 579 default: 580 break; 581 } 582 583 return false; 584 } 585 586 /// \brief If there are any implicit member functions with the given name 587 /// that need to be declared in the given declaration context, do so. 588 static void DeclareImplicitMemberFunctionsWithName(Sema &S, 589 DeclarationName Name, 590 const DeclContext *DC) { 591 if (!DC) 592 return; 593 594 switch (Name.getNameKind()) { 595 case DeclarationName::CXXConstructorName: 596 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) 597 if (Record->getDefinition() && 598 CanDeclareSpecialMemberFunction(S.Context, Record)) { 599 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record); 600 if (Record->needsImplicitDefaultConstructor()) 601 S.DeclareImplicitDefaultConstructor(Class); 602 if (!Record->hasDeclaredCopyConstructor()) 603 S.DeclareImplicitCopyConstructor(Class); 604 if (S.getLangOptions().CPlusPlus0x && 605 Record->needsImplicitMoveConstructor()) 606 S.DeclareImplicitMoveConstructor(Class); 607 } 608 break; 609 610 case DeclarationName::CXXDestructorName: 611 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) 612 if (Record->getDefinition() && !Record->hasDeclaredDestructor() && 613 CanDeclareSpecialMemberFunction(S.Context, Record)) 614 S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record)); 615 break; 616 617 case DeclarationName::CXXOperatorName: 618 if (Name.getCXXOverloadedOperator() != OO_Equal) 619 break; 620 621 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) { 622 if (Record->getDefinition() && 623 CanDeclareSpecialMemberFunction(S.Context, Record)) { 624 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record); 625 if (!Record->hasDeclaredCopyAssignment()) 626 S.DeclareImplicitCopyAssignment(Class); 627 if (S.getLangOptions().CPlusPlus0x && 628 Record->needsImplicitMoveAssignment()) 629 S.DeclareImplicitMoveAssignment(Class); 630 } 631 } 632 break; 633 634 default: 635 break; 636 } 637 } 638 639 // Adds all qualifying matches for a name within a decl context to the 640 // given lookup result. Returns true if any matches were found. 641 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) { 642 bool Found = false; 643 644 // Lazily declare C++ special member functions. 645 if (S.getLangOptions().CPlusPlus) 646 DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), DC); 647 648 // Perform lookup into this declaration context. 649 DeclContext::lookup_const_iterator I, E; 650 for (llvm::tie(I, E) = DC->lookup(R.getLookupName()); I != E; ++I) { 651 NamedDecl *D = *I; 652 if (R.isAcceptableDecl(D)) { 653 R.addDecl(D); 654 Found = true; 655 } 656 } 657 658 if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R)) 659 return true; 660 661 if (R.getLookupName().getNameKind() 662 != DeclarationName::CXXConversionFunctionName || 663 R.getLookupName().getCXXNameType()->isDependentType() || 664 !isa<CXXRecordDecl>(DC)) 665 return Found; 666 667 // C++ [temp.mem]p6: 668 // A specialization of a conversion function template is not found by 669 // name lookup. Instead, any conversion function templates visible in the 670 // context of the use are considered. [...] 671 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC); 672 if (!Record->isCompleteDefinition()) 673 return Found; 674 675 const UnresolvedSetImpl *Unresolved = Record->getConversionFunctions(); 676 for (UnresolvedSetImpl::iterator U = Unresolved->begin(), 677 UEnd = Unresolved->end(); U != UEnd; ++U) { 678 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U); 679 if (!ConvTemplate) 680 continue; 681 682 // When we're performing lookup for the purposes of redeclaration, just 683 // add the conversion function template. When we deduce template 684 // arguments for specializations, we'll end up unifying the return 685 // type of the new declaration with the type of the function template. 686 if (R.isForRedeclaration()) { 687 R.addDecl(ConvTemplate); 688 Found = true; 689 continue; 690 } 691 692 // C++ [temp.mem]p6: 693 // [...] For each such operator, if argument deduction succeeds 694 // (14.9.2.3), the resulting specialization is used as if found by 695 // name lookup. 696 // 697 // When referencing a conversion function for any purpose other than 698 // a redeclaration (such that we'll be building an expression with the 699 // result), perform template argument deduction and place the 700 // specialization into the result set. We do this to avoid forcing all 701 // callers to perform special deduction for conversion functions. 702 TemplateDeductionInfo Info(R.getSema().Context, R.getNameLoc()); 703 FunctionDecl *Specialization = 0; 704 705 const FunctionProtoType *ConvProto 706 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>(); 707 assert(ConvProto && "Nonsensical conversion function template type"); 708 709 // Compute the type of the function that we would expect the conversion 710 // function to have, if it were to match the name given. 711 // FIXME: Calling convention! 712 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo(); 713 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_Default); 714 EPI.ExceptionSpecType = EST_None; 715 EPI.NumExceptions = 0; 716 QualType ExpectedType 717 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(), 718 0, 0, EPI); 719 720 // Perform template argument deduction against the type that we would 721 // expect the function to have. 722 if (R.getSema().DeduceTemplateArguments(ConvTemplate, 0, ExpectedType, 723 Specialization, Info) 724 == Sema::TDK_Success) { 725 R.addDecl(Specialization); 726 Found = true; 727 } 728 } 729 730 return Found; 731 } 732 733 // Performs C++ unqualified lookup into the given file context. 734 static bool 735 CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context, 736 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) { 737 738 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!"); 739 740 // Perform direct name lookup into the LookupCtx. 741 bool Found = LookupDirect(S, R, NS); 742 743 // Perform direct name lookup into the namespaces nominated by the 744 // using directives whose common ancestor is this namespace. 745 UnqualUsingDirectiveSet::const_iterator UI, UEnd; 746 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(NS); 747 748 for (; UI != UEnd; ++UI) 749 if (LookupDirect(S, R, UI->getNominatedNamespace())) 750 Found = true; 751 752 R.resolveKind(); 753 754 return Found; 755 } 756 757 static bool isNamespaceOrTranslationUnitScope(Scope *S) { 758 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) 759 return Ctx->isFileContext(); 760 return false; 761 } 762 763 // Find the next outer declaration context from this scope. This 764 // routine actually returns the semantic outer context, which may 765 // differ from the lexical context (encoded directly in the Scope 766 // stack) when we are parsing a member of a class template. In this 767 // case, the second element of the pair will be true, to indicate that 768 // name lookup should continue searching in this semantic context when 769 // it leaves the current template parameter scope. 770 static std::pair<DeclContext *, bool> findOuterContext(Scope *S) { 771 DeclContext *DC = static_cast<DeclContext *>(S->getEntity()); 772 DeclContext *Lexical = 0; 773 for (Scope *OuterS = S->getParent(); OuterS; 774 OuterS = OuterS->getParent()) { 775 if (OuterS->getEntity()) { 776 Lexical = static_cast<DeclContext *>(OuterS->getEntity()); 777 break; 778 } 779 } 780 781 // C++ [temp.local]p8: 782 // In the definition of a member of a class template that appears 783 // outside of the namespace containing the class template 784 // definition, the name of a template-parameter hides the name of 785 // a member of this namespace. 786 // 787 // Example: 788 // 789 // namespace N { 790 // class C { }; 791 // 792 // template<class T> class B { 793 // void f(T); 794 // }; 795 // } 796 // 797 // template<class C> void N::B<C>::f(C) { 798 // C b; // C is the template parameter, not N::C 799 // } 800 // 801 // In this example, the lexical context we return is the 802 // TranslationUnit, while the semantic context is the namespace N. 803 if (!Lexical || !DC || !S->getParent() || 804 !S->getParent()->isTemplateParamScope()) 805 return std::make_pair(Lexical, false); 806 807 // Find the outermost template parameter scope. 808 // For the example, this is the scope for the template parameters of 809 // template<class C>. 810 Scope *OutermostTemplateScope = S->getParent(); 811 while (OutermostTemplateScope->getParent() && 812 OutermostTemplateScope->getParent()->isTemplateParamScope()) 813 OutermostTemplateScope = OutermostTemplateScope->getParent(); 814 815 // Find the namespace context in which the original scope occurs. In 816 // the example, this is namespace N. 817 DeclContext *Semantic = DC; 818 while (!Semantic->isFileContext()) 819 Semantic = Semantic->getParent(); 820 821 // Find the declaration context just outside of the template 822 // parameter scope. This is the context in which the template is 823 // being lexically declaration (a namespace context). In the 824 // example, this is the global scope. 825 if (Lexical->isFileContext() && !Lexical->Equals(Semantic) && 826 Lexical->Encloses(Semantic)) 827 return std::make_pair(Semantic, true); 828 829 return std::make_pair(Lexical, false); 830 } 831 832 bool Sema::CppLookupName(LookupResult &R, Scope *S) { 833 assert(getLangOptions().CPlusPlus && "Can perform only C++ lookup"); 834 835 DeclarationName Name = R.getLookupName(); 836 837 // If this is the name of an implicitly-declared special member function, 838 // go through the scope stack to implicitly declare 839 if (isImplicitlyDeclaredMemberFunctionName(Name)) { 840 for (Scope *PreS = S; PreS; PreS = PreS->getParent()) 841 if (DeclContext *DC = static_cast<DeclContext *>(PreS->getEntity())) 842 DeclareImplicitMemberFunctionsWithName(*this, Name, DC); 843 } 844 845 // Implicitly declare member functions with the name we're looking for, if in 846 // fact we are in a scope where it matters. 847 848 Scope *Initial = S; 849 IdentifierResolver::iterator 850 I = IdResolver.begin(Name), 851 IEnd = IdResolver.end(); 852 853 // First we lookup local scope. 854 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir] 855 // ...During unqualified name lookup (3.4.1), the names appear as if 856 // they were declared in the nearest enclosing namespace which contains 857 // both the using-directive and the nominated namespace. 858 // [Note: in this context, "contains" means "contains directly or 859 // indirectly". 860 // 861 // For example: 862 // namespace A { int i; } 863 // void foo() { 864 // int i; 865 // { 866 // using namespace A; 867 // ++i; // finds local 'i', A::i appears at global scope 868 // } 869 // } 870 // 871 DeclContext *OutsideOfTemplateParamDC = 0; 872 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) { 873 DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity()); 874 875 // Check whether the IdResolver has anything in this scope. 876 bool Found = false; 877 for (; I != IEnd && S->isDeclScope(*I); ++I) { 878 if (R.isAcceptableDecl(*I)) { 879 Found = true; 880 R.addDecl(*I); 881 } 882 } 883 if (Found) { 884 R.resolveKind(); 885 if (S->isClassScope()) 886 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx)) 887 R.setNamingClass(Record); 888 return true; 889 } 890 891 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC && 892 S->getParent() && !S->getParent()->isTemplateParamScope()) { 893 // We've just searched the last template parameter scope and 894 // found nothing, so look into the the contexts between the 895 // lexical and semantic declaration contexts returned by 896 // findOuterContext(). This implements the name lookup behavior 897 // of C++ [temp.local]p8. 898 Ctx = OutsideOfTemplateParamDC; 899 OutsideOfTemplateParamDC = 0; 900 } 901 902 if (Ctx) { 903 DeclContext *OuterCtx; 904 bool SearchAfterTemplateScope; 905 llvm::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S); 906 if (SearchAfterTemplateScope) 907 OutsideOfTemplateParamDC = OuterCtx; 908 909 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 910 // We do not directly look into transparent contexts, since 911 // those entities will be found in the nearest enclosing 912 // non-transparent context. 913 if (Ctx->isTransparentContext()) 914 continue; 915 916 // We do not look directly into function or method contexts, 917 // since all of the local variables and parameters of the 918 // function/method are present within the Scope. 919 if (Ctx->isFunctionOrMethod()) { 920 // If we have an Objective-C instance method, look for ivars 921 // in the corresponding interface. 922 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 923 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo()) 924 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) { 925 ObjCInterfaceDecl *ClassDeclared; 926 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable( 927 Name.getAsIdentifierInfo(), 928 ClassDeclared)) { 929 if (R.isAcceptableDecl(Ivar)) { 930 R.addDecl(Ivar); 931 R.resolveKind(); 932 return true; 933 } 934 } 935 } 936 } 937 938 continue; 939 } 940 941 // Perform qualified name lookup into this context. 942 // FIXME: In some cases, we know that every name that could be found by 943 // this qualified name lookup will also be on the identifier chain. For 944 // example, inside a class without any base classes, we never need to 945 // perform qualified lookup because all of the members are on top of the 946 // identifier chain. 947 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true)) 948 return true; 949 } 950 } 951 } 952 953 // Stop if we ran out of scopes. 954 // FIXME: This really, really shouldn't be happening. 955 if (!S) return false; 956 957 // If we are looking for members, no need to look into global/namespace scope. 958 if (R.getLookupKind() == LookupMemberName) 959 return false; 960 961 // Collect UsingDirectiveDecls in all scopes, and recursively all 962 // nominated namespaces by those using-directives. 963 // 964 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we 965 // don't build it for each lookup! 966 967 UnqualUsingDirectiveSet UDirs; 968 UDirs.visitScopeChain(Initial, S); 969 UDirs.done(); 970 971 // Lookup namespace scope, and global scope. 972 // Unqualified name lookup in C++ requires looking into scopes 973 // that aren't strictly lexical, and therefore we walk through the 974 // context as well as walking through the scopes. 975 976 for (; S; S = S->getParent()) { 977 // Check whether the IdResolver has anything in this scope. 978 bool Found = false; 979 for (; I != IEnd && S->isDeclScope(*I); ++I) { 980 if (R.isAcceptableDecl(*I)) { 981 // We found something. Look for anything else in our scope 982 // with this same name and in an acceptable identifier 983 // namespace, so that we can construct an overload set if we 984 // need to. 985 Found = true; 986 R.addDecl(*I); 987 } 988 } 989 990 if (Found && S->isTemplateParamScope()) { 991 R.resolveKind(); 992 return true; 993 } 994 995 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity()); 996 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC && 997 S->getParent() && !S->getParent()->isTemplateParamScope()) { 998 // We've just searched the last template parameter scope and 999 // found nothing, so look into the the contexts between the 1000 // lexical and semantic declaration contexts returned by 1001 // findOuterContext(). This implements the name lookup behavior 1002 // of C++ [temp.local]p8. 1003 Ctx = OutsideOfTemplateParamDC; 1004 OutsideOfTemplateParamDC = 0; 1005 } 1006 1007 if (Ctx) { 1008 DeclContext *OuterCtx; 1009 bool SearchAfterTemplateScope; 1010 llvm::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S); 1011 if (SearchAfterTemplateScope) 1012 OutsideOfTemplateParamDC = OuterCtx; 1013 1014 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 1015 // We do not directly look into transparent contexts, since 1016 // those entities will be found in the nearest enclosing 1017 // non-transparent context. 1018 if (Ctx->isTransparentContext()) 1019 continue; 1020 1021 // If we have a context, and it's not a context stashed in the 1022 // template parameter scope for an out-of-line definition, also 1023 // look into that context. 1024 if (!(Found && S && S->isTemplateParamScope())) { 1025 assert(Ctx->isFileContext() && 1026 "We should have been looking only at file context here already."); 1027 1028 // Look into context considering using-directives. 1029 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) 1030 Found = true; 1031 } 1032 1033 if (Found) { 1034 R.resolveKind(); 1035 return true; 1036 } 1037 1038 if (R.isForRedeclaration() && !Ctx->isTransparentContext()) 1039 return false; 1040 } 1041 } 1042 1043 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext()) 1044 return false; 1045 } 1046 1047 return !R.empty(); 1048 } 1049 1050 /// @brief Perform unqualified name lookup starting from a given 1051 /// scope. 1052 /// 1053 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is 1054 /// used to find names within the current scope. For example, 'x' in 1055 /// @code 1056 /// int x; 1057 /// int f() { 1058 /// return x; // unqualified name look finds 'x' in the global scope 1059 /// } 1060 /// @endcode 1061 /// 1062 /// Different lookup criteria can find different names. For example, a 1063 /// particular scope can have both a struct and a function of the same 1064 /// name, and each can be found by certain lookup criteria. For more 1065 /// information about lookup criteria, see the documentation for the 1066 /// class LookupCriteria. 1067 /// 1068 /// @param S The scope from which unqualified name lookup will 1069 /// begin. If the lookup criteria permits, name lookup may also search 1070 /// in the parent scopes. 1071 /// 1072 /// @param Name The name of the entity that we are searching for. 1073 /// 1074 /// @param Loc If provided, the source location where we're performing 1075 /// name lookup. At present, this is only used to produce diagnostics when 1076 /// C library functions (like "malloc") are implicitly declared. 1077 /// 1078 /// @returns The result of name lookup, which includes zero or more 1079 /// declarations and possibly additional information used to diagnose 1080 /// ambiguities. 1081 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) { 1082 DeclarationName Name = R.getLookupName(); 1083 if (!Name) return false; 1084 1085 LookupNameKind NameKind = R.getLookupKind(); 1086 1087 if (!getLangOptions().CPlusPlus) { 1088 // Unqualified name lookup in C/Objective-C is purely lexical, so 1089 // search in the declarations attached to the name. 1090 if (NameKind == Sema::LookupRedeclarationWithLinkage) { 1091 // Find the nearest non-transparent declaration scope. 1092 while (!(S->getFlags() & Scope::DeclScope) || 1093 (S->getEntity() && 1094 static_cast<DeclContext *>(S->getEntity()) 1095 ->isTransparentContext())) 1096 S = S->getParent(); 1097 } 1098 1099 unsigned IDNS = R.getIdentifierNamespace(); 1100 1101 // Scan up the scope chain looking for a decl that matches this 1102 // identifier that is in the appropriate namespace. This search 1103 // should not take long, as shadowing of names is uncommon, and 1104 // deep shadowing is extremely uncommon. 1105 bool LeftStartingScope = false; 1106 1107 for (IdentifierResolver::iterator I = IdResolver.begin(Name), 1108 IEnd = IdResolver.end(); 1109 I != IEnd; ++I) 1110 if ((*I)->isInIdentifierNamespace(IDNS)) { 1111 if (NameKind == LookupRedeclarationWithLinkage) { 1112 // Determine whether this (or a previous) declaration is 1113 // out-of-scope. 1114 if (!LeftStartingScope && !S->isDeclScope(*I)) 1115 LeftStartingScope = true; 1116 1117 // If we found something outside of our starting scope that 1118 // does not have linkage, skip it. 1119 if (LeftStartingScope && !((*I)->hasLinkage())) 1120 continue; 1121 } 1122 else if (NameKind == LookupObjCImplicitSelfParam && 1123 !isa<ImplicitParamDecl>(*I)) 1124 continue; 1125 1126 R.addDecl(*I); 1127 1128 if ((*I)->getAttr<OverloadableAttr>()) { 1129 // If this declaration has the "overloadable" attribute, we 1130 // might have a set of overloaded functions. 1131 1132 // Figure out what scope the identifier is in. 1133 while (!(S->getFlags() & Scope::DeclScope) || 1134 !S->isDeclScope(*I)) 1135 S = S->getParent(); 1136 1137 // Find the last declaration in this scope (with the same 1138 // name, naturally). 1139 IdentifierResolver::iterator LastI = I; 1140 for (++LastI; LastI != IEnd; ++LastI) { 1141 if (!S->isDeclScope(*LastI)) 1142 break; 1143 R.addDecl(*LastI); 1144 } 1145 } 1146 1147 R.resolveKind(); 1148 1149 return true; 1150 } 1151 } else { 1152 // Perform C++ unqualified name lookup. 1153 if (CppLookupName(R, S)) 1154 return true; 1155 } 1156 1157 // If we didn't find a use of this identifier, and if the identifier 1158 // corresponds to a compiler builtin, create the decl object for the builtin 1159 // now, injecting it into translation unit scope, and return it. 1160 if (AllowBuiltinCreation && LookupBuiltin(*this, R)) 1161 return true; 1162 1163 // If we didn't find a use of this identifier, the ExternalSource 1164 // may be able to handle the situation. 1165 // Note: some lookup failures are expected! 1166 // See e.g. R.isForRedeclaration(). 1167 return (ExternalSource && ExternalSource->LookupUnqualified(R, S)); 1168 } 1169 1170 /// @brief Perform qualified name lookup in the namespaces nominated by 1171 /// using directives by the given context. 1172 /// 1173 /// C++98 [namespace.qual]p2: 1174 /// Given X::m (where X is a user-declared namespace), or given ::m 1175 /// (where X is the global namespace), let S be the set of all 1176 /// declarations of m in X and in the transitive closure of all 1177 /// namespaces nominated by using-directives in X and its used 1178 /// namespaces, except that using-directives are ignored in any 1179 /// namespace, including X, directly containing one or more 1180 /// declarations of m. No namespace is searched more than once in 1181 /// the lookup of a name. If S is the empty set, the program is 1182 /// ill-formed. Otherwise, if S has exactly one member, or if the 1183 /// context of the reference is a using-declaration 1184 /// (namespace.udecl), S is the required set of declarations of 1185 /// m. Otherwise if the use of m is not one that allows a unique 1186 /// declaration to be chosen from S, the program is ill-formed. 1187 /// C++98 [namespace.qual]p5: 1188 /// During the lookup of a qualified namespace member name, if the 1189 /// lookup finds more than one declaration of the member, and if one 1190 /// declaration introduces a class name or enumeration name and the 1191 /// other declarations either introduce the same object, the same 1192 /// enumerator or a set of functions, the non-type name hides the 1193 /// class or enumeration name if and only if the declarations are 1194 /// from the same namespace; otherwise (the declarations are from 1195 /// different namespaces), the program is ill-formed. 1196 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R, 1197 DeclContext *StartDC) { 1198 assert(StartDC->isFileContext() && "start context is not a file context"); 1199 1200 DeclContext::udir_iterator I = StartDC->using_directives_begin(); 1201 DeclContext::udir_iterator E = StartDC->using_directives_end(); 1202 1203 if (I == E) return false; 1204 1205 // We have at least added all these contexts to the queue. 1206 llvm::DenseSet<DeclContext*> Visited; 1207 Visited.insert(StartDC); 1208 1209 // We have not yet looked into these namespaces, much less added 1210 // their "using-children" to the queue. 1211 SmallVector<NamespaceDecl*, 8> Queue; 1212 1213 // We have already looked into the initial namespace; seed the queue 1214 // with its using-children. 1215 for (; I != E; ++I) { 1216 NamespaceDecl *ND = (*I)->getNominatedNamespace()->getOriginalNamespace(); 1217 if (Visited.insert(ND).second) 1218 Queue.push_back(ND); 1219 } 1220 1221 // The easiest way to implement the restriction in [namespace.qual]p5 1222 // is to check whether any of the individual results found a tag 1223 // and, if so, to declare an ambiguity if the final result is not 1224 // a tag. 1225 bool FoundTag = false; 1226 bool FoundNonTag = false; 1227 1228 LookupResult LocalR(LookupResult::Temporary, R); 1229 1230 bool Found = false; 1231 while (!Queue.empty()) { 1232 NamespaceDecl *ND = Queue.back(); 1233 Queue.pop_back(); 1234 1235 // We go through some convolutions here to avoid copying results 1236 // between LookupResults. 1237 bool UseLocal = !R.empty(); 1238 LookupResult &DirectR = UseLocal ? LocalR : R; 1239 bool FoundDirect = LookupDirect(S, DirectR, ND); 1240 1241 if (FoundDirect) { 1242 // First do any local hiding. 1243 DirectR.resolveKind(); 1244 1245 // If the local result is a tag, remember that. 1246 if (DirectR.isSingleTagDecl()) 1247 FoundTag = true; 1248 else 1249 FoundNonTag = true; 1250 1251 // Append the local results to the total results if necessary. 1252 if (UseLocal) { 1253 R.addAllDecls(LocalR); 1254 LocalR.clear(); 1255 } 1256 } 1257 1258 // If we find names in this namespace, ignore its using directives. 1259 if (FoundDirect) { 1260 Found = true; 1261 continue; 1262 } 1263 1264 for (llvm::tie(I,E) = ND->getUsingDirectives(); I != E; ++I) { 1265 NamespaceDecl *Nom = (*I)->getNominatedNamespace(); 1266 if (Visited.insert(Nom).second) 1267 Queue.push_back(Nom); 1268 } 1269 } 1270 1271 if (Found) { 1272 if (FoundTag && FoundNonTag) 1273 R.setAmbiguousQualifiedTagHiding(); 1274 else 1275 R.resolveKind(); 1276 } 1277 1278 return Found; 1279 } 1280 1281 /// \brief Callback that looks for any member of a class with the given name. 1282 static bool LookupAnyMember(const CXXBaseSpecifier *Specifier, 1283 CXXBasePath &Path, 1284 void *Name) { 1285 RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl(); 1286 1287 DeclarationName N = DeclarationName::getFromOpaquePtr(Name); 1288 Path.Decls = BaseRecord->lookup(N); 1289 return Path.Decls.first != Path.Decls.second; 1290 } 1291 1292 /// \brief Determine whether the given set of member declarations contains only 1293 /// static members, nested types, and enumerators. 1294 template<typename InputIterator> 1295 static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) { 1296 Decl *D = (*First)->getUnderlyingDecl(); 1297 if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D)) 1298 return true; 1299 1300 if (isa<CXXMethodDecl>(D)) { 1301 // Determine whether all of the methods are static. 1302 bool AllMethodsAreStatic = true; 1303 for(; First != Last; ++First) { 1304 D = (*First)->getUnderlyingDecl(); 1305 1306 if (!isa<CXXMethodDecl>(D)) { 1307 assert(isa<TagDecl>(D) && "Non-function must be a tag decl"); 1308 break; 1309 } 1310 1311 if (!cast<CXXMethodDecl>(D)->isStatic()) { 1312 AllMethodsAreStatic = false; 1313 break; 1314 } 1315 } 1316 1317 if (AllMethodsAreStatic) 1318 return true; 1319 } 1320 1321 return false; 1322 } 1323 1324 /// \brief Perform qualified name lookup into a given context. 1325 /// 1326 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find 1327 /// names when the context of those names is explicit specified, e.g., 1328 /// "std::vector" or "x->member", or as part of unqualified name lookup. 1329 /// 1330 /// Different lookup criteria can find different names. For example, a 1331 /// particular scope can have both a struct and a function of the same 1332 /// name, and each can be found by certain lookup criteria. For more 1333 /// information about lookup criteria, see the documentation for the 1334 /// class LookupCriteria. 1335 /// 1336 /// \param R captures both the lookup criteria and any lookup results found. 1337 /// 1338 /// \param LookupCtx The context in which qualified name lookup will 1339 /// search. If the lookup criteria permits, name lookup may also search 1340 /// in the parent contexts or (for C++ classes) base classes. 1341 /// 1342 /// \param InUnqualifiedLookup true if this is qualified name lookup that 1343 /// occurs as part of unqualified name lookup. 1344 /// 1345 /// \returns true if lookup succeeded, false if it failed. 1346 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 1347 bool InUnqualifiedLookup) { 1348 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context"); 1349 1350 if (!R.getLookupName()) 1351 return false; 1352 1353 // Make sure that the declaration context is complete. 1354 assert((!isa<TagDecl>(LookupCtx) || 1355 LookupCtx->isDependentContext() || 1356 cast<TagDecl>(LookupCtx)->isCompleteDefinition() || 1357 Context.getTypeDeclType(cast<TagDecl>(LookupCtx))->getAs<TagType>() 1358 ->isBeingDefined()) && 1359 "Declaration context must already be complete!"); 1360 1361 // Perform qualified name lookup into the LookupCtx. 1362 if (LookupDirect(*this, R, LookupCtx)) { 1363 R.resolveKind(); 1364 if (isa<CXXRecordDecl>(LookupCtx)) 1365 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx)); 1366 return true; 1367 } 1368 1369 // Don't descend into implied contexts for redeclarations. 1370 // C++98 [namespace.qual]p6: 1371 // In a declaration for a namespace member in which the 1372 // declarator-id is a qualified-id, given that the qualified-id 1373 // for the namespace member has the form 1374 // nested-name-specifier unqualified-id 1375 // the unqualified-id shall name a member of the namespace 1376 // designated by the nested-name-specifier. 1377 // See also [class.mfct]p5 and [class.static.data]p2. 1378 if (R.isForRedeclaration()) 1379 return false; 1380 1381 // If this is a namespace, look it up in the implied namespaces. 1382 if (LookupCtx->isFileContext()) 1383 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx); 1384 1385 // If this isn't a C++ class, we aren't allowed to look into base 1386 // classes, we're done. 1387 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx); 1388 if (!LookupRec || !LookupRec->getDefinition()) 1389 return false; 1390 1391 // If we're performing qualified name lookup into a dependent class, 1392 // then we are actually looking into a current instantiation. If we have any 1393 // dependent base classes, then we either have to delay lookup until 1394 // template instantiation time (at which point all bases will be available) 1395 // or we have to fail. 1396 if (!InUnqualifiedLookup && LookupRec->isDependentContext() && 1397 LookupRec->hasAnyDependentBases()) { 1398 R.setNotFoundInCurrentInstantiation(); 1399 return false; 1400 } 1401 1402 // Perform lookup into our base classes. 1403 CXXBasePaths Paths; 1404 Paths.setOrigin(LookupRec); 1405 1406 // Look for this member in our base classes 1407 CXXRecordDecl::BaseMatchesCallback *BaseCallback = 0; 1408 switch (R.getLookupKind()) { 1409 case LookupObjCImplicitSelfParam: 1410 case LookupOrdinaryName: 1411 case LookupMemberName: 1412 case LookupRedeclarationWithLinkage: 1413 BaseCallback = &CXXRecordDecl::FindOrdinaryMember; 1414 break; 1415 1416 case LookupTagName: 1417 BaseCallback = &CXXRecordDecl::FindTagMember; 1418 break; 1419 1420 case LookupAnyName: 1421 BaseCallback = &LookupAnyMember; 1422 break; 1423 1424 case LookupUsingDeclName: 1425 // This lookup is for redeclarations only. 1426 1427 case LookupOperatorName: 1428 case LookupNamespaceName: 1429 case LookupObjCProtocolName: 1430 case LookupLabel: 1431 // These lookups will never find a member in a C++ class (or base class). 1432 return false; 1433 1434 case LookupNestedNameSpecifierName: 1435 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember; 1436 break; 1437 } 1438 1439 if (!LookupRec->lookupInBases(BaseCallback, 1440 R.getLookupName().getAsOpaquePtr(), Paths)) 1441 return false; 1442 1443 R.setNamingClass(LookupRec); 1444 1445 // C++ [class.member.lookup]p2: 1446 // [...] If the resulting set of declarations are not all from 1447 // sub-objects of the same type, or the set has a nonstatic member 1448 // and includes members from distinct sub-objects, there is an 1449 // ambiguity and the program is ill-formed. Otherwise that set is 1450 // the result of the lookup. 1451 QualType SubobjectType; 1452 int SubobjectNumber = 0; 1453 AccessSpecifier SubobjectAccess = AS_none; 1454 1455 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); 1456 Path != PathEnd; ++Path) { 1457 const CXXBasePathElement &PathElement = Path->back(); 1458 1459 // Pick the best (i.e. most permissive i.e. numerically lowest) access 1460 // across all paths. 1461 SubobjectAccess = std::min(SubobjectAccess, Path->Access); 1462 1463 // Determine whether we're looking at a distinct sub-object or not. 1464 if (SubobjectType.isNull()) { 1465 // This is the first subobject we've looked at. Record its type. 1466 SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); 1467 SubobjectNumber = PathElement.SubobjectNumber; 1468 continue; 1469 } 1470 1471 if (SubobjectType 1472 != Context.getCanonicalType(PathElement.Base->getType())) { 1473 // We found members of the given name in two subobjects of 1474 // different types. If the declaration sets aren't the same, this 1475 // this lookup is ambiguous. 1476 if (HasOnlyStaticMembers(Path->Decls.first, Path->Decls.second)) { 1477 CXXBasePaths::paths_iterator FirstPath = Paths.begin(); 1478 DeclContext::lookup_iterator FirstD = FirstPath->Decls.first; 1479 DeclContext::lookup_iterator CurrentD = Path->Decls.first; 1480 1481 while (FirstD != FirstPath->Decls.second && 1482 CurrentD != Path->Decls.second) { 1483 if ((*FirstD)->getUnderlyingDecl()->getCanonicalDecl() != 1484 (*CurrentD)->getUnderlyingDecl()->getCanonicalDecl()) 1485 break; 1486 1487 ++FirstD; 1488 ++CurrentD; 1489 } 1490 1491 if (FirstD == FirstPath->Decls.second && 1492 CurrentD == Path->Decls.second) 1493 continue; 1494 } 1495 1496 R.setAmbiguousBaseSubobjectTypes(Paths); 1497 return true; 1498 } 1499 1500 if (SubobjectNumber != PathElement.SubobjectNumber) { 1501 // We have a different subobject of the same type. 1502 1503 // C++ [class.member.lookup]p5: 1504 // A static member, a nested type or an enumerator defined in 1505 // a base class T can unambiguously be found even if an object 1506 // has more than one base class subobject of type T. 1507 if (HasOnlyStaticMembers(Path->Decls.first, Path->Decls.second)) 1508 continue; 1509 1510 // We have found a nonstatic member name in multiple, distinct 1511 // subobjects. Name lookup is ambiguous. 1512 R.setAmbiguousBaseSubobjects(Paths); 1513 return true; 1514 } 1515 } 1516 1517 // Lookup in a base class succeeded; return these results. 1518 1519 DeclContext::lookup_iterator I, E; 1520 for (llvm::tie(I,E) = Paths.front().Decls; I != E; ++I) { 1521 NamedDecl *D = *I; 1522 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess, 1523 D->getAccess()); 1524 R.addDecl(D, AS); 1525 } 1526 R.resolveKind(); 1527 return true; 1528 } 1529 1530 /// @brief Performs name lookup for a name that was parsed in the 1531 /// source code, and may contain a C++ scope specifier. 1532 /// 1533 /// This routine is a convenience routine meant to be called from 1534 /// contexts that receive a name and an optional C++ scope specifier 1535 /// (e.g., "N::M::x"). It will then perform either qualified or 1536 /// unqualified name lookup (with LookupQualifiedName or LookupName, 1537 /// respectively) on the given name and return those results. 1538 /// 1539 /// @param S The scope from which unqualified name lookup will 1540 /// begin. 1541 /// 1542 /// @param SS An optional C++ scope-specifier, e.g., "::N::M". 1543 /// 1544 /// @param EnteringContext Indicates whether we are going to enter the 1545 /// context of the scope-specifier SS (if present). 1546 /// 1547 /// @returns True if any decls were found (but possibly ambiguous) 1548 bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS, 1549 bool AllowBuiltinCreation, bool EnteringContext) { 1550 if (SS && SS->isInvalid()) { 1551 // When the scope specifier is invalid, don't even look for 1552 // anything. 1553 return false; 1554 } 1555 1556 if (SS && SS->isSet()) { 1557 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { 1558 // We have resolved the scope specifier to a particular declaration 1559 // contex, and will perform name lookup in that context. 1560 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC)) 1561 return false; 1562 1563 R.setContextRange(SS->getRange()); 1564 1565 return LookupQualifiedName(R, DC); 1566 } 1567 1568 // We could not resolve the scope specified to a specific declaration 1569 // context, which means that SS refers to an unknown specialization. 1570 // Name lookup can't find anything in this case. 1571 return false; 1572 } 1573 1574 // Perform unqualified name lookup starting in the given scope. 1575 return LookupName(R, S, AllowBuiltinCreation); 1576 } 1577 1578 1579 /// @brief Produce a diagnostic describing the ambiguity that resulted 1580 /// from name lookup. 1581 /// 1582 /// @param Result The ambiguous name lookup result. 1583 /// 1584 /// @param Name The name of the entity that name lookup was 1585 /// searching for. 1586 /// 1587 /// @param NameLoc The location of the name within the source code. 1588 /// 1589 /// @param LookupRange A source range that provides more 1590 /// source-location information concerning the lookup itself. For 1591 /// example, this range might highlight a nested-name-specifier that 1592 /// precedes the name. 1593 /// 1594 /// @returns true 1595 bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result) { 1596 assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); 1597 1598 DeclarationName Name = Result.getLookupName(); 1599 SourceLocation NameLoc = Result.getNameLoc(); 1600 SourceRange LookupRange = Result.getContextRange(); 1601 1602 switch (Result.getAmbiguityKind()) { 1603 case LookupResult::AmbiguousBaseSubobjects: { 1604 CXXBasePaths *Paths = Result.getBasePaths(); 1605 QualType SubobjectType = Paths->front().back().Base->getType(); 1606 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) 1607 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) 1608 << LookupRange; 1609 1610 DeclContext::lookup_iterator Found = Paths->front().Decls.first; 1611 while (isa<CXXMethodDecl>(*Found) && 1612 cast<CXXMethodDecl>(*Found)->isStatic()) 1613 ++Found; 1614 1615 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); 1616 1617 return true; 1618 } 1619 1620 case LookupResult::AmbiguousBaseSubobjectTypes: { 1621 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) 1622 << Name << LookupRange; 1623 1624 CXXBasePaths *Paths = Result.getBasePaths(); 1625 std::set<Decl *> DeclsPrinted; 1626 for (CXXBasePaths::paths_iterator Path = Paths->begin(), 1627 PathEnd = Paths->end(); 1628 Path != PathEnd; ++Path) { 1629 Decl *D = *Path->Decls.first; 1630 if (DeclsPrinted.insert(D).second) 1631 Diag(D->getLocation(), diag::note_ambiguous_member_found); 1632 } 1633 1634 return true; 1635 } 1636 1637 case LookupResult::AmbiguousTagHiding: { 1638 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange; 1639 1640 llvm::SmallPtrSet<NamedDecl*,8> TagDecls; 1641 1642 LookupResult::iterator DI, DE = Result.end(); 1643 for (DI = Result.begin(); DI != DE; ++DI) 1644 if (TagDecl *TD = dyn_cast<TagDecl>(*DI)) { 1645 TagDecls.insert(TD); 1646 Diag(TD->getLocation(), diag::note_hidden_tag); 1647 } 1648 1649 for (DI = Result.begin(); DI != DE; ++DI) 1650 if (!isa<TagDecl>(*DI)) 1651 Diag((*DI)->getLocation(), diag::note_hiding_object); 1652 1653 // For recovery purposes, go ahead and implement the hiding. 1654 LookupResult::Filter F = Result.makeFilter(); 1655 while (F.hasNext()) { 1656 if (TagDecls.count(F.next())) 1657 F.erase(); 1658 } 1659 F.done(); 1660 1661 return true; 1662 } 1663 1664 case LookupResult::AmbiguousReference: { 1665 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; 1666 1667 LookupResult::iterator DI = Result.begin(), DE = Result.end(); 1668 for (; DI != DE; ++DI) 1669 Diag((*DI)->getLocation(), diag::note_ambiguous_candidate) << *DI; 1670 1671 return true; 1672 } 1673 } 1674 1675 llvm_unreachable("unknown ambiguity kind"); 1676 return true; 1677 } 1678 1679 namespace { 1680 struct AssociatedLookup { 1681 AssociatedLookup(Sema &S, 1682 Sema::AssociatedNamespaceSet &Namespaces, 1683 Sema::AssociatedClassSet &Classes) 1684 : S(S), Namespaces(Namespaces), Classes(Classes) { 1685 } 1686 1687 Sema &S; 1688 Sema::AssociatedNamespaceSet &Namespaces; 1689 Sema::AssociatedClassSet &Classes; 1690 }; 1691 } 1692 1693 static void 1694 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T); 1695 1696 static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces, 1697 DeclContext *Ctx) { 1698 // Add the associated namespace for this class. 1699 1700 // We don't use DeclContext::getEnclosingNamespaceContext() as this may 1701 // be a locally scoped record. 1702 1703 // We skip out of inline namespaces. The innermost non-inline namespace 1704 // contains all names of all its nested inline namespaces anyway, so we can 1705 // replace the entire inline namespace tree with its root. 1706 while (Ctx->isRecord() || Ctx->isTransparentContext() || 1707 Ctx->isInlineNamespace()) 1708 Ctx = Ctx->getParent(); 1709 1710 if (Ctx->isFileContext()) 1711 Namespaces.insert(Ctx->getPrimaryContext()); 1712 } 1713 1714 // \brief Add the associated classes and namespaces for argument-dependent 1715 // lookup that involves a template argument (C++ [basic.lookup.koenig]p2). 1716 static void 1717 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 1718 const TemplateArgument &Arg) { 1719 // C++ [basic.lookup.koenig]p2, last bullet: 1720 // -- [...] ; 1721 switch (Arg.getKind()) { 1722 case TemplateArgument::Null: 1723 break; 1724 1725 case TemplateArgument::Type: 1726 // [...] the namespaces and classes associated with the types of the 1727 // template arguments provided for template type parameters (excluding 1728 // template template parameters) 1729 addAssociatedClassesAndNamespaces(Result, Arg.getAsType()); 1730 break; 1731 1732 case TemplateArgument::Template: 1733 case TemplateArgument::TemplateExpansion: { 1734 // [...] the namespaces in which any template template arguments are 1735 // defined; and the classes in which any member templates used as 1736 // template template arguments are defined. 1737 TemplateName Template = Arg.getAsTemplateOrTemplatePattern(); 1738 if (ClassTemplateDecl *ClassTemplate 1739 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) { 1740 DeclContext *Ctx = ClassTemplate->getDeclContext(); 1741 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1742 Result.Classes.insert(EnclosingClass); 1743 // Add the associated namespace for this class. 1744 CollectEnclosingNamespace(Result.Namespaces, Ctx); 1745 } 1746 break; 1747 } 1748 1749 case TemplateArgument::Declaration: 1750 case TemplateArgument::Integral: 1751 case TemplateArgument::Expression: 1752 // [Note: non-type template arguments do not contribute to the set of 1753 // associated namespaces. ] 1754 break; 1755 1756 case TemplateArgument::Pack: 1757 for (TemplateArgument::pack_iterator P = Arg.pack_begin(), 1758 PEnd = Arg.pack_end(); 1759 P != PEnd; ++P) 1760 addAssociatedClassesAndNamespaces(Result, *P); 1761 break; 1762 } 1763 } 1764 1765 // \brief Add the associated classes and namespaces for 1766 // argument-dependent lookup with an argument of class type 1767 // (C++ [basic.lookup.koenig]p2). 1768 static void 1769 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 1770 CXXRecordDecl *Class) { 1771 1772 // Just silently ignore anything whose name is __va_list_tag. 1773 if (Class->getDeclName() == Result.S.VAListTagName) 1774 return; 1775 1776 // C++ [basic.lookup.koenig]p2: 1777 // [...] 1778 // -- If T is a class type (including unions), its associated 1779 // classes are: the class itself; the class of which it is a 1780 // member, if any; and its direct and indirect base 1781 // classes. Its associated namespaces are the namespaces in 1782 // which its associated classes are defined. 1783 1784 // Add the class of which it is a member, if any. 1785 DeclContext *Ctx = Class->getDeclContext(); 1786 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1787 Result.Classes.insert(EnclosingClass); 1788 // Add the associated namespace for this class. 1789 CollectEnclosingNamespace(Result.Namespaces, Ctx); 1790 1791 // Add the class itself. If we've already seen this class, we don't 1792 // need to visit base classes. 1793 if (!Result.Classes.insert(Class)) 1794 return; 1795 1796 // -- If T is a template-id, its associated namespaces and classes are 1797 // the namespace in which the template is defined; for member 1798 // templates, the member template's class; the namespaces and classes 1799 // associated with the types of the template arguments provided for 1800 // template type parameters (excluding template template parameters); the 1801 // namespaces in which any template template arguments are defined; and 1802 // the classes in which any member templates used as template template 1803 // arguments are defined. [Note: non-type template arguments do not 1804 // contribute to the set of associated namespaces. ] 1805 if (ClassTemplateSpecializationDecl *Spec 1806 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) { 1807 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); 1808 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1809 Result.Classes.insert(EnclosingClass); 1810 // Add the associated namespace for this class. 1811 CollectEnclosingNamespace(Result.Namespaces, Ctx); 1812 1813 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); 1814 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 1815 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]); 1816 } 1817 1818 // Only recurse into base classes for complete types. 1819 if (!Class->hasDefinition()) { 1820 // FIXME: we might need to instantiate templates here 1821 return; 1822 } 1823 1824 // Add direct and indirect base classes along with their associated 1825 // namespaces. 1826 SmallVector<CXXRecordDecl *, 32> Bases; 1827 Bases.push_back(Class); 1828 while (!Bases.empty()) { 1829 // Pop this class off the stack. 1830 Class = Bases.back(); 1831 Bases.pop_back(); 1832 1833 // Visit the base classes. 1834 for (CXXRecordDecl::base_class_iterator Base = Class->bases_begin(), 1835 BaseEnd = Class->bases_end(); 1836 Base != BaseEnd; ++Base) { 1837 const RecordType *BaseType = Base->getType()->getAs<RecordType>(); 1838 // In dependent contexts, we do ADL twice, and the first time around, 1839 // the base type might be a dependent TemplateSpecializationType, or a 1840 // TemplateTypeParmType. If that happens, simply ignore it. 1841 // FIXME: If we want to support export, we probably need to add the 1842 // namespace of the template in a TemplateSpecializationType, or even 1843 // the classes and namespaces of known non-dependent arguments. 1844 if (!BaseType) 1845 continue; 1846 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 1847 if (Result.Classes.insert(BaseDecl)) { 1848 // Find the associated namespace for this base class. 1849 DeclContext *BaseCtx = BaseDecl->getDeclContext(); 1850 CollectEnclosingNamespace(Result.Namespaces, BaseCtx); 1851 1852 // Make sure we visit the bases of this base class. 1853 if (BaseDecl->bases_begin() != BaseDecl->bases_end()) 1854 Bases.push_back(BaseDecl); 1855 } 1856 } 1857 } 1858 } 1859 1860 // \brief Add the associated classes and namespaces for 1861 // argument-dependent lookup with an argument of type T 1862 // (C++ [basic.lookup.koenig]p2). 1863 static void 1864 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) { 1865 // C++ [basic.lookup.koenig]p2: 1866 // 1867 // For each argument type T in the function call, there is a set 1868 // of zero or more associated namespaces and a set of zero or more 1869 // associated classes to be considered. The sets of namespaces and 1870 // classes is determined entirely by the types of the function 1871 // arguments (and the namespace of any template template 1872 // argument). Typedef names and using-declarations used to specify 1873 // the types do not contribute to this set. The sets of namespaces 1874 // and classes are determined in the following way: 1875 1876 SmallVector<const Type *, 16> Queue; 1877 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr(); 1878 1879 while (true) { 1880 switch (T->getTypeClass()) { 1881 1882 #define TYPE(Class, Base) 1883 #define DEPENDENT_TYPE(Class, Base) case Type::Class: 1884 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 1885 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class: 1886 #define ABSTRACT_TYPE(Class, Base) 1887 #include "clang/AST/TypeNodes.def" 1888 // T is canonical. We can also ignore dependent types because 1889 // we don't need to do ADL at the definition point, but if we 1890 // wanted to implement template export (or if we find some other 1891 // use for associated classes and namespaces...) this would be 1892 // wrong. 1893 break; 1894 1895 // -- If T is a pointer to U or an array of U, its associated 1896 // namespaces and classes are those associated with U. 1897 case Type::Pointer: 1898 T = cast<PointerType>(T)->getPointeeType().getTypePtr(); 1899 continue; 1900 case Type::ConstantArray: 1901 case Type::IncompleteArray: 1902 case Type::VariableArray: 1903 T = cast<ArrayType>(T)->getElementType().getTypePtr(); 1904 continue; 1905 1906 // -- If T is a fundamental type, its associated sets of 1907 // namespaces and classes are both empty. 1908 case Type::Builtin: 1909 break; 1910 1911 // -- If T is a class type (including unions), its associated 1912 // classes are: the class itself; the class of which it is a 1913 // member, if any; and its direct and indirect base 1914 // classes. Its associated namespaces are the namespaces in 1915 // which its associated classes are defined. 1916 case Type::Record: { 1917 CXXRecordDecl *Class 1918 = cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl()); 1919 addAssociatedClassesAndNamespaces(Result, Class); 1920 break; 1921 } 1922 1923 // -- If T is an enumeration type, its associated namespace is 1924 // the namespace in which it is defined. If it is class 1925 // member, its associated class is the member's class; else 1926 // it has no associated class. 1927 case Type::Enum: { 1928 EnumDecl *Enum = cast<EnumType>(T)->getDecl(); 1929 1930 DeclContext *Ctx = Enum->getDeclContext(); 1931 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1932 Result.Classes.insert(EnclosingClass); 1933 1934 // Add the associated namespace for this class. 1935 CollectEnclosingNamespace(Result.Namespaces, Ctx); 1936 1937 break; 1938 } 1939 1940 // -- If T is a function type, its associated namespaces and 1941 // classes are those associated with the function parameter 1942 // types and those associated with the return type. 1943 case Type::FunctionProto: { 1944 const FunctionProtoType *Proto = cast<FunctionProtoType>(T); 1945 for (FunctionProtoType::arg_type_iterator Arg = Proto->arg_type_begin(), 1946 ArgEnd = Proto->arg_type_end(); 1947 Arg != ArgEnd; ++Arg) 1948 Queue.push_back(Arg->getTypePtr()); 1949 // fallthrough 1950 } 1951 case Type::FunctionNoProto: { 1952 const FunctionType *FnType = cast<FunctionType>(T); 1953 T = FnType->getResultType().getTypePtr(); 1954 continue; 1955 } 1956 1957 // -- If T is a pointer to a member function of a class X, its 1958 // associated namespaces and classes are those associated 1959 // with the function parameter types and return type, 1960 // together with those associated with X. 1961 // 1962 // -- If T is a pointer to a data member of class X, its 1963 // associated namespaces and classes are those associated 1964 // with the member type together with those associated with 1965 // X. 1966 case Type::MemberPointer: { 1967 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T); 1968 1969 // Queue up the class type into which this points. 1970 Queue.push_back(MemberPtr->getClass()); 1971 1972 // And directly continue with the pointee type. 1973 T = MemberPtr->getPointeeType().getTypePtr(); 1974 continue; 1975 } 1976 1977 // As an extension, treat this like a normal pointer. 1978 case Type::BlockPointer: 1979 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr(); 1980 continue; 1981 1982 // References aren't covered by the standard, but that's such an 1983 // obvious defect that we cover them anyway. 1984 case Type::LValueReference: 1985 case Type::RValueReference: 1986 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr(); 1987 continue; 1988 1989 // These are fundamental types. 1990 case Type::Vector: 1991 case Type::ExtVector: 1992 case Type::Complex: 1993 break; 1994 1995 // If T is an Objective-C object or interface type, or a pointer to an 1996 // object or interface type, the associated namespace is the global 1997 // namespace. 1998 case Type::ObjCObject: 1999 case Type::ObjCInterface: 2000 case Type::ObjCObjectPointer: 2001 Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl()); 2002 break; 2003 2004 // Atomic types are just wrappers; use the associations of the 2005 // contained type. 2006 case Type::Atomic: 2007 T = cast<AtomicType>(T)->getValueType().getTypePtr(); 2008 continue; 2009 } 2010 2011 if (Queue.empty()) break; 2012 T = Queue.back(); 2013 Queue.pop_back(); 2014 } 2015 } 2016 2017 /// \brief Find the associated classes and namespaces for 2018 /// argument-dependent lookup for a call with the given set of 2019 /// arguments. 2020 /// 2021 /// This routine computes the sets of associated classes and associated 2022 /// namespaces searched by argument-dependent lookup 2023 /// (C++ [basic.lookup.argdep]) for a given set of arguments. 2024 void 2025 Sema::FindAssociatedClassesAndNamespaces(Expr **Args, unsigned NumArgs, 2026 AssociatedNamespaceSet &AssociatedNamespaces, 2027 AssociatedClassSet &AssociatedClasses) { 2028 AssociatedNamespaces.clear(); 2029 AssociatedClasses.clear(); 2030 2031 AssociatedLookup Result(*this, AssociatedNamespaces, AssociatedClasses); 2032 2033 // C++ [basic.lookup.koenig]p2: 2034 // For each argument type T in the function call, there is a set 2035 // of zero or more associated namespaces and a set of zero or more 2036 // associated classes to be considered. The sets of namespaces and 2037 // classes is determined entirely by the types of the function 2038 // arguments (and the namespace of any template template 2039 // argument). 2040 for (unsigned ArgIdx = 0; ArgIdx != NumArgs; ++ArgIdx) { 2041 Expr *Arg = Args[ArgIdx]; 2042 2043 if (Arg->getType() != Context.OverloadTy) { 2044 addAssociatedClassesAndNamespaces(Result, Arg->getType()); 2045 continue; 2046 } 2047 2048 // [...] In addition, if the argument is the name or address of a 2049 // set of overloaded functions and/or function templates, its 2050 // associated classes and namespaces are the union of those 2051 // associated with each of the members of the set: the namespace 2052 // in which the function or function template is defined and the 2053 // classes and namespaces associated with its (non-dependent) 2054 // parameter types and return type. 2055 Arg = Arg->IgnoreParens(); 2056 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg)) 2057 if (unaryOp->getOpcode() == UO_AddrOf) 2058 Arg = unaryOp->getSubExpr(); 2059 2060 UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg); 2061 if (!ULE) continue; 2062 2063 for (UnresolvedSetIterator I = ULE->decls_begin(), E = ULE->decls_end(); 2064 I != E; ++I) { 2065 // Look through any using declarations to find the underlying function. 2066 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 2067 2068 FunctionDecl *FDecl = dyn_cast<FunctionDecl>(Fn); 2069 if (!FDecl) 2070 FDecl = cast<FunctionTemplateDecl>(Fn)->getTemplatedDecl(); 2071 2072 // Add the classes and namespaces associated with the parameter 2073 // types and return type of this function. 2074 addAssociatedClassesAndNamespaces(Result, FDecl->getType()); 2075 } 2076 } 2077 } 2078 2079 /// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is 2080 /// an acceptable non-member overloaded operator for a call whose 2081 /// arguments have types T1 (and, if non-empty, T2). This routine 2082 /// implements the check in C++ [over.match.oper]p3b2 concerning 2083 /// enumeration types. 2084 static bool 2085 IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn, 2086 QualType T1, QualType T2, 2087 ASTContext &Context) { 2088 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType())) 2089 return true; 2090 2091 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType())) 2092 return true; 2093 2094 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>(); 2095 if (Proto->getNumArgs() < 1) 2096 return false; 2097 2098 if (T1->isEnumeralType()) { 2099 QualType ArgType = Proto->getArgType(0).getNonReferenceType(); 2100 if (Context.hasSameUnqualifiedType(T1, ArgType)) 2101 return true; 2102 } 2103 2104 if (Proto->getNumArgs() < 2) 2105 return false; 2106 2107 if (!T2.isNull() && T2->isEnumeralType()) { 2108 QualType ArgType = Proto->getArgType(1).getNonReferenceType(); 2109 if (Context.hasSameUnqualifiedType(T2, ArgType)) 2110 return true; 2111 } 2112 2113 return false; 2114 } 2115 2116 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name, 2117 SourceLocation Loc, 2118 LookupNameKind NameKind, 2119 RedeclarationKind Redecl) { 2120 LookupResult R(*this, Name, Loc, NameKind, Redecl); 2121 LookupName(R, S); 2122 return R.getAsSingle<NamedDecl>(); 2123 } 2124 2125 /// \brief Find the protocol with the given name, if any. 2126 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II, 2127 SourceLocation IdLoc) { 2128 Decl *D = LookupSingleName(TUScope, II, IdLoc, 2129 LookupObjCProtocolName); 2130 return cast_or_null<ObjCProtocolDecl>(D); 2131 } 2132 2133 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, 2134 QualType T1, QualType T2, 2135 UnresolvedSetImpl &Functions) { 2136 // C++ [over.match.oper]p3: 2137 // -- The set of non-member candidates is the result of the 2138 // unqualified lookup of operator@ in the context of the 2139 // expression according to the usual rules for name lookup in 2140 // unqualified function calls (3.4.2) except that all member 2141 // functions are ignored. However, if no operand has a class 2142 // type, only those non-member functions in the lookup set 2143 // that have a first parameter of type T1 or "reference to 2144 // (possibly cv-qualified) T1", when T1 is an enumeration 2145 // type, or (if there is a right operand) a second parameter 2146 // of type T2 or "reference to (possibly cv-qualified) T2", 2147 // when T2 is an enumeration type, are candidate functions. 2148 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2149 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName); 2150 LookupName(Operators, S); 2151 2152 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); 2153 2154 if (Operators.empty()) 2155 return; 2156 2157 for (LookupResult::iterator Op = Operators.begin(), OpEnd = Operators.end(); 2158 Op != OpEnd; ++Op) { 2159 NamedDecl *Found = (*Op)->getUnderlyingDecl(); 2160 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Found)) { 2161 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context)) 2162 Functions.addDecl(*Op, Op.getAccess()); // FIXME: canonical FD 2163 } else if (FunctionTemplateDecl *FunTmpl 2164 = dyn_cast<FunctionTemplateDecl>(Found)) { 2165 // FIXME: friend operators? 2166 // FIXME: do we need to check IsAcceptableNonMemberOperatorCandidate, 2167 // later? 2168 if (!FunTmpl->getDeclContext()->isRecord()) 2169 Functions.addDecl(*Op, Op.getAccess()); 2170 } 2171 } 2172 } 2173 2174 Sema::SpecialMemberOverloadResult *Sema::LookupSpecialMember(CXXRecordDecl *RD, 2175 CXXSpecialMember SM, 2176 bool ConstArg, 2177 bool VolatileArg, 2178 bool RValueThis, 2179 bool ConstThis, 2180 bool VolatileThis) { 2181 RD = RD->getDefinition(); 2182 assert((RD && !RD->isBeingDefined()) && 2183 "doing special member lookup into record that isn't fully complete"); 2184 if (RValueThis || ConstThis || VolatileThis) 2185 assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) && 2186 "constructors and destructors always have unqualified lvalue this"); 2187 if (ConstArg || VolatileArg) 2188 assert((SM != CXXDefaultConstructor && SM != CXXDestructor) && 2189 "parameter-less special members can't have qualified arguments"); 2190 2191 llvm::FoldingSetNodeID ID; 2192 ID.AddPointer(RD); 2193 ID.AddInteger(SM); 2194 ID.AddInteger(ConstArg); 2195 ID.AddInteger(VolatileArg); 2196 ID.AddInteger(RValueThis); 2197 ID.AddInteger(ConstThis); 2198 ID.AddInteger(VolatileThis); 2199 2200 void *InsertPoint; 2201 SpecialMemberOverloadResult *Result = 2202 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint); 2203 2204 // This was already cached 2205 if (Result) 2206 return Result; 2207 2208 Result = BumpAlloc.Allocate<SpecialMemberOverloadResult>(); 2209 Result = new (Result) SpecialMemberOverloadResult(ID); 2210 SpecialMemberCache.InsertNode(Result, InsertPoint); 2211 2212 if (SM == CXXDestructor) { 2213 if (!RD->hasDeclaredDestructor()) 2214 DeclareImplicitDestructor(RD); 2215 CXXDestructorDecl *DD = RD->getDestructor(); 2216 assert(DD && "record without a destructor"); 2217 Result->setMethod(DD); 2218 Result->setSuccess(DD->isDeleted()); 2219 Result->setConstParamMatch(false); 2220 return Result; 2221 } 2222 2223 // Prepare for overload resolution. Here we construct a synthetic argument 2224 // if necessary and make sure that implicit functions are declared. 2225 CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD)); 2226 DeclarationName Name; 2227 Expr *Arg = 0; 2228 unsigned NumArgs; 2229 2230 if (SM == CXXDefaultConstructor) { 2231 Name = Context.DeclarationNames.getCXXConstructorName(CanTy); 2232 NumArgs = 0; 2233 if (RD->needsImplicitDefaultConstructor()) 2234 DeclareImplicitDefaultConstructor(RD); 2235 } else { 2236 if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) { 2237 Name = Context.DeclarationNames.getCXXConstructorName(CanTy); 2238 if (!RD->hasDeclaredCopyConstructor()) 2239 DeclareImplicitCopyConstructor(RD); 2240 if (getLangOptions().CPlusPlus0x && RD->needsImplicitMoveConstructor()) 2241 DeclareImplicitMoveConstructor(RD); 2242 } else { 2243 Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal); 2244 if (!RD->hasDeclaredCopyAssignment()) 2245 DeclareImplicitCopyAssignment(RD); 2246 if (getLangOptions().CPlusPlus0x && RD->needsImplicitMoveAssignment()) 2247 DeclareImplicitMoveAssignment(RD); 2248 } 2249 2250 QualType ArgType = CanTy; 2251 if (ConstArg) 2252 ArgType.addConst(); 2253 if (VolatileArg) 2254 ArgType.addVolatile(); 2255 2256 // This isn't /really/ specified by the standard, but it's implied 2257 // we should be working from an RValue in the case of move to ensure 2258 // that we prefer to bind to rvalue references, and an LValue in the 2259 // case of copy to ensure we don't bind to rvalue references. 2260 // Possibly an XValue is actually correct in the case of move, but 2261 // there is no semantic difference for class types in this restricted 2262 // case. 2263 ExprValueKind VK; 2264 if (SM == CXXCopyConstructor || SM == CXXCopyAssignment) 2265 VK = VK_LValue; 2266 else 2267 VK = VK_RValue; 2268 2269 NumArgs = 1; 2270 Arg = new (Context) OpaqueValueExpr(SourceLocation(), ArgType, VK); 2271 } 2272 2273 // Create the object argument 2274 QualType ThisTy = CanTy; 2275 if (ConstThis) 2276 ThisTy.addConst(); 2277 if (VolatileThis) 2278 ThisTy.addVolatile(); 2279 Expr::Classification Classification = 2280 (new (Context) OpaqueValueExpr(SourceLocation(), ThisTy, 2281 RValueThis ? VK_RValue : VK_LValue))-> 2282 Classify(Context); 2283 2284 // Now we perform lookup on the name we computed earlier and do overload 2285 // resolution. Lookup is only performed directly into the class since there 2286 // will always be a (possibly implicit) declaration to shadow any others. 2287 OverloadCandidateSet OCS((SourceLocation())); 2288 DeclContext::lookup_iterator I, E; 2289 Result->setConstParamMatch(false); 2290 2291 llvm::tie(I, E) = RD->lookup(Name); 2292 assert((I != E) && 2293 "lookup for a constructor or assignment operator was empty"); 2294 for ( ; I != E; ++I) { 2295 Decl *Cand = *I; 2296 2297 if (Cand->isInvalidDecl()) 2298 continue; 2299 2300 if (UsingShadowDecl *U = dyn_cast<UsingShadowDecl>(Cand)) { 2301 // FIXME: [namespace.udecl]p15 says that we should only consider a 2302 // using declaration here if it does not match a declaration in the 2303 // derived class. We do not implement this correctly in other cases 2304 // either. 2305 Cand = U->getTargetDecl(); 2306 2307 if (Cand->isInvalidDecl()) 2308 continue; 2309 } 2310 2311 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand)) { 2312 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) 2313 AddMethodCandidate(M, DeclAccessPair::make(M, AS_public), RD, ThisTy, 2314 Classification, &Arg, NumArgs, OCS, true); 2315 else 2316 AddOverloadCandidate(M, DeclAccessPair::make(M, AS_public), &Arg, 2317 NumArgs, OCS, true); 2318 2319 // Here we're looking for a const parameter to speed up creation of 2320 // implicit copy methods. 2321 if ((SM == CXXCopyAssignment && M->isCopyAssignmentOperator()) || 2322 (SM == CXXCopyConstructor && 2323 cast<CXXConstructorDecl>(M)->isCopyConstructor())) { 2324 QualType ArgType = M->getType()->getAs<FunctionProtoType>()->getArgType(0); 2325 if (!ArgType->isReferenceType() || 2326 ArgType->getPointeeType().isConstQualified()) 2327 Result->setConstParamMatch(true); 2328 } 2329 } else if (FunctionTemplateDecl *Tmpl = 2330 dyn_cast<FunctionTemplateDecl>(Cand)) { 2331 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) 2332 AddMethodTemplateCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public), 2333 RD, 0, ThisTy, Classification, &Arg, NumArgs, 2334 OCS, true); 2335 else 2336 AddTemplateOverloadCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public), 2337 0, &Arg, NumArgs, OCS, true); 2338 } else { 2339 assert(isa<UsingDecl>(Cand) && "illegal Kind of operator = Decl"); 2340 } 2341 } 2342 2343 OverloadCandidateSet::iterator Best; 2344 switch (OCS.BestViableFunction(*this, SourceLocation(), Best)) { 2345 case OR_Success: 2346 Result->setMethod(cast<CXXMethodDecl>(Best->Function)); 2347 Result->setSuccess(true); 2348 break; 2349 2350 case OR_Deleted: 2351 Result->setMethod(cast<CXXMethodDecl>(Best->Function)); 2352 Result->setSuccess(false); 2353 break; 2354 2355 case OR_Ambiguous: 2356 case OR_No_Viable_Function: 2357 Result->setMethod(0); 2358 Result->setSuccess(false); 2359 break; 2360 } 2361 2362 return Result; 2363 } 2364 2365 /// \brief Look up the default constructor for the given class. 2366 CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) { 2367 SpecialMemberOverloadResult *Result = 2368 LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false, 2369 false, false); 2370 2371 return cast_or_null<CXXConstructorDecl>(Result->getMethod()); 2372 } 2373 2374 /// \brief Look up the copying constructor for the given class. 2375 CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class, 2376 unsigned Quals, 2377 bool *ConstParamMatch) { 2378 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 2379 "non-const, non-volatile qualifiers for copy ctor arg"); 2380 SpecialMemberOverloadResult *Result = 2381 LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const, 2382 Quals & Qualifiers::Volatile, false, false, false); 2383 2384 if (ConstParamMatch) 2385 *ConstParamMatch = Result->hasConstParamMatch(); 2386 2387 return cast_or_null<CXXConstructorDecl>(Result->getMethod()); 2388 } 2389 2390 /// \brief Look up the moving constructor for the given class. 2391 CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class) { 2392 SpecialMemberOverloadResult *Result = 2393 LookupSpecialMember(Class, CXXMoveConstructor, false, 2394 false, false, false, false); 2395 2396 return cast_or_null<CXXConstructorDecl>(Result->getMethod()); 2397 } 2398 2399 /// \brief Look up the constructors for the given class. 2400 DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) { 2401 // If the implicit constructors have not yet been declared, do so now. 2402 if (CanDeclareSpecialMemberFunction(Context, Class)) { 2403 if (Class->needsImplicitDefaultConstructor()) 2404 DeclareImplicitDefaultConstructor(Class); 2405 if (!Class->hasDeclaredCopyConstructor()) 2406 DeclareImplicitCopyConstructor(Class); 2407 if (getLangOptions().CPlusPlus0x && Class->needsImplicitMoveConstructor()) 2408 DeclareImplicitMoveConstructor(Class); 2409 } 2410 2411 CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class)); 2412 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T); 2413 return Class->lookup(Name); 2414 } 2415 2416 /// \brief Look up the copying assignment operator for the given class. 2417 CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class, 2418 unsigned Quals, bool RValueThis, 2419 unsigned ThisQuals, 2420 bool *ConstParamMatch) { 2421 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 2422 "non-const, non-volatile qualifiers for copy assignment arg"); 2423 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 2424 "non-const, non-volatile qualifiers for copy assignment this"); 2425 SpecialMemberOverloadResult *Result = 2426 LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const, 2427 Quals & Qualifiers::Volatile, RValueThis, 2428 ThisQuals & Qualifiers::Const, 2429 ThisQuals & Qualifiers::Volatile); 2430 2431 if (ConstParamMatch) 2432 *ConstParamMatch = Result->hasConstParamMatch(); 2433 2434 return Result->getMethod(); 2435 } 2436 2437 /// \brief Look up the moving assignment operator for the given class. 2438 CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class, 2439 bool RValueThis, 2440 unsigned ThisQuals) { 2441 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 2442 "non-const, non-volatile qualifiers for copy assignment this"); 2443 SpecialMemberOverloadResult *Result = 2444 LookupSpecialMember(Class, CXXMoveAssignment, false, false, RValueThis, 2445 ThisQuals & Qualifiers::Const, 2446 ThisQuals & Qualifiers::Volatile); 2447 2448 return Result->getMethod(); 2449 } 2450 2451 /// \brief Look for the destructor of the given class. 2452 /// 2453 /// During semantic analysis, this routine should be used in lieu of 2454 /// CXXRecordDecl::getDestructor(). 2455 /// 2456 /// \returns The destructor for this class. 2457 CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) { 2458 return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor, 2459 false, false, false, 2460 false, false)->getMethod()); 2461 } 2462 2463 void ADLResult::insert(NamedDecl *New) { 2464 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())]; 2465 2466 // If we haven't yet seen a decl for this key, or the last decl 2467 // was exactly this one, we're done. 2468 if (Old == 0 || Old == New) { 2469 Old = New; 2470 return; 2471 } 2472 2473 // Otherwise, decide which is a more recent redeclaration. 2474 FunctionDecl *OldFD, *NewFD; 2475 if (isa<FunctionTemplateDecl>(New)) { 2476 OldFD = cast<FunctionTemplateDecl>(Old)->getTemplatedDecl(); 2477 NewFD = cast<FunctionTemplateDecl>(New)->getTemplatedDecl(); 2478 } else { 2479 OldFD = cast<FunctionDecl>(Old); 2480 NewFD = cast<FunctionDecl>(New); 2481 } 2482 2483 FunctionDecl *Cursor = NewFD; 2484 while (true) { 2485 Cursor = Cursor->getPreviousDeclaration(); 2486 2487 // If we got to the end without finding OldFD, OldFD is the newer 2488 // declaration; leave things as they are. 2489 if (!Cursor) return; 2490 2491 // If we do find OldFD, then NewFD is newer. 2492 if (Cursor == OldFD) break; 2493 2494 // Otherwise, keep looking. 2495 } 2496 2497 Old = New; 2498 } 2499 2500 void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator, 2501 Expr **Args, unsigned NumArgs, 2502 ADLResult &Result, 2503 bool StdNamespaceIsAssociated) { 2504 // Find all of the associated namespaces and classes based on the 2505 // arguments we have. 2506 AssociatedNamespaceSet AssociatedNamespaces; 2507 AssociatedClassSet AssociatedClasses; 2508 FindAssociatedClassesAndNamespaces(Args, NumArgs, 2509 AssociatedNamespaces, 2510 AssociatedClasses); 2511 if (StdNamespaceIsAssociated && StdNamespace) 2512 AssociatedNamespaces.insert(getStdNamespace()); 2513 2514 QualType T1, T2; 2515 if (Operator) { 2516 T1 = Args[0]->getType(); 2517 if (NumArgs >= 2) 2518 T2 = Args[1]->getType(); 2519 } 2520 2521 // C++ [basic.lookup.argdep]p3: 2522 // Let X be the lookup set produced by unqualified lookup (3.4.1) 2523 // and let Y be the lookup set produced by argument dependent 2524 // lookup (defined as follows). If X contains [...] then Y is 2525 // empty. Otherwise Y is the set of declarations found in the 2526 // namespaces associated with the argument types as described 2527 // below. The set of declarations found by the lookup of the name 2528 // is the union of X and Y. 2529 // 2530 // Here, we compute Y and add its members to the overloaded 2531 // candidate set. 2532 for (AssociatedNamespaceSet::iterator NS = AssociatedNamespaces.begin(), 2533 NSEnd = AssociatedNamespaces.end(); 2534 NS != NSEnd; ++NS) { 2535 // When considering an associated namespace, the lookup is the 2536 // same as the lookup performed when the associated namespace is 2537 // used as a qualifier (3.4.3.2) except that: 2538 // 2539 // -- Any using-directives in the associated namespace are 2540 // ignored. 2541 // 2542 // -- Any namespace-scope friend functions declared in 2543 // associated classes are visible within their respective 2544 // namespaces even if they are not visible during an ordinary 2545 // lookup (11.4). 2546 DeclContext::lookup_iterator I, E; 2547 for (llvm::tie(I, E) = (*NS)->lookup(Name); I != E; ++I) { 2548 NamedDecl *D = *I; 2549 // If the only declaration here is an ordinary friend, consider 2550 // it only if it was declared in an associated classes. 2551 if (D->getIdentifierNamespace() == Decl::IDNS_OrdinaryFriend) { 2552 DeclContext *LexDC = D->getLexicalDeclContext(); 2553 if (!AssociatedClasses.count(cast<CXXRecordDecl>(LexDC))) 2554 continue; 2555 } 2556 2557 if (isa<UsingShadowDecl>(D)) 2558 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2559 2560 if (isa<FunctionDecl>(D)) { 2561 if (Operator && 2562 !IsAcceptableNonMemberOperatorCandidate(cast<FunctionDecl>(D), 2563 T1, T2, Context)) 2564 continue; 2565 } else if (!isa<FunctionTemplateDecl>(D)) 2566 continue; 2567 2568 Result.insert(D); 2569 } 2570 } 2571 } 2572 2573 //---------------------------------------------------------------------------- 2574 // Search for all visible declarations. 2575 //---------------------------------------------------------------------------- 2576 VisibleDeclConsumer::~VisibleDeclConsumer() { } 2577 2578 namespace { 2579 2580 class ShadowContextRAII; 2581 2582 class VisibleDeclsRecord { 2583 public: 2584 /// \brief An entry in the shadow map, which is optimized to store a 2585 /// single declaration (the common case) but can also store a list 2586 /// of declarations. 2587 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry; 2588 2589 private: 2590 /// \brief A mapping from declaration names to the declarations that have 2591 /// this name within a particular scope. 2592 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap; 2593 2594 /// \brief A list of shadow maps, which is used to model name hiding. 2595 std::list<ShadowMap> ShadowMaps; 2596 2597 /// \brief The declaration contexts we have already visited. 2598 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts; 2599 2600 friend class ShadowContextRAII; 2601 2602 public: 2603 /// \brief Determine whether we have already visited this context 2604 /// (and, if not, note that we are going to visit that context now). 2605 bool visitedContext(DeclContext *Ctx) { 2606 return !VisitedContexts.insert(Ctx); 2607 } 2608 2609 bool alreadyVisitedContext(DeclContext *Ctx) { 2610 return VisitedContexts.count(Ctx); 2611 } 2612 2613 /// \brief Determine whether the given declaration is hidden in the 2614 /// current scope. 2615 /// 2616 /// \returns the declaration that hides the given declaration, or 2617 /// NULL if no such declaration exists. 2618 NamedDecl *checkHidden(NamedDecl *ND); 2619 2620 /// \brief Add a declaration to the current shadow map. 2621 void add(NamedDecl *ND) { 2622 ShadowMaps.back()[ND->getDeclName()].push_back(ND); 2623 } 2624 }; 2625 2626 /// \brief RAII object that records when we've entered a shadow context. 2627 class ShadowContextRAII { 2628 VisibleDeclsRecord &Visible; 2629 2630 typedef VisibleDeclsRecord::ShadowMap ShadowMap; 2631 2632 public: 2633 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) { 2634 Visible.ShadowMaps.push_back(ShadowMap()); 2635 } 2636 2637 ~ShadowContextRAII() { 2638 Visible.ShadowMaps.pop_back(); 2639 } 2640 }; 2641 2642 } // end anonymous namespace 2643 2644 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) { 2645 // Look through using declarations. 2646 ND = ND->getUnderlyingDecl(); 2647 2648 unsigned IDNS = ND->getIdentifierNamespace(); 2649 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin(); 2650 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend(); 2651 SM != SMEnd; ++SM) { 2652 ShadowMap::iterator Pos = SM->find(ND->getDeclName()); 2653 if (Pos == SM->end()) 2654 continue; 2655 2656 for (ShadowMapEntry::iterator I = Pos->second.begin(), 2657 IEnd = Pos->second.end(); 2658 I != IEnd; ++I) { 2659 // A tag declaration does not hide a non-tag declaration. 2660 if ((*I)->hasTagIdentifierNamespace() && 2661 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary | 2662 Decl::IDNS_ObjCProtocol))) 2663 continue; 2664 2665 // Protocols are in distinct namespaces from everything else. 2666 if ((((*I)->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol) 2667 || (IDNS & Decl::IDNS_ObjCProtocol)) && 2668 (*I)->getIdentifierNamespace() != IDNS) 2669 continue; 2670 2671 // Functions and function templates in the same scope overload 2672 // rather than hide. FIXME: Look for hiding based on function 2673 // signatures! 2674 if ((*I)->isFunctionOrFunctionTemplate() && 2675 ND->isFunctionOrFunctionTemplate() && 2676 SM == ShadowMaps.rbegin()) 2677 continue; 2678 2679 // We've found a declaration that hides this one. 2680 return *I; 2681 } 2682 } 2683 2684 return 0; 2685 } 2686 2687 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result, 2688 bool QualifiedNameLookup, 2689 bool InBaseClass, 2690 VisibleDeclConsumer &Consumer, 2691 VisibleDeclsRecord &Visited) { 2692 if (!Ctx) 2693 return; 2694 2695 // Make sure we don't visit the same context twice. 2696 if (Visited.visitedContext(Ctx->getPrimaryContext())) 2697 return; 2698 2699 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx)) 2700 Result.getSema().ForceDeclarationOfImplicitMembers(Class); 2701 2702 // Enumerate all of the results in this context. 2703 for (DeclContext *CurCtx = Ctx->getPrimaryContext(); CurCtx; 2704 CurCtx = CurCtx->getNextContext()) { 2705 for (DeclContext::decl_iterator D = CurCtx->decls_begin(), 2706 DEnd = CurCtx->decls_end(); 2707 D != DEnd; ++D) { 2708 if (NamedDecl *ND = dyn_cast<NamedDecl>(*D)) { 2709 if (Result.isAcceptableDecl(ND)) { 2710 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass); 2711 Visited.add(ND); 2712 } 2713 } else if (ObjCForwardProtocolDecl *ForwardProto 2714 = dyn_cast<ObjCForwardProtocolDecl>(*D)) { 2715 for (ObjCForwardProtocolDecl::protocol_iterator 2716 P = ForwardProto->protocol_begin(), 2717 PEnd = ForwardProto->protocol_end(); 2718 P != PEnd; 2719 ++P) { 2720 if (Result.isAcceptableDecl(*P)) { 2721 Consumer.FoundDecl(*P, Visited.checkHidden(*P), Ctx, InBaseClass); 2722 Visited.add(*P); 2723 } 2724 } 2725 } else if (ObjCClassDecl *Class = dyn_cast<ObjCClassDecl>(*D)) { 2726 ObjCInterfaceDecl *IFace = Class->getForwardInterfaceDecl(); 2727 if (Result.isAcceptableDecl(IFace)) { 2728 Consumer.FoundDecl(IFace, Visited.checkHidden(IFace), Ctx, 2729 InBaseClass); 2730 Visited.add(IFace); 2731 } 2732 } 2733 2734 // Visit transparent contexts and inline namespaces inside this context. 2735 if (DeclContext *InnerCtx = dyn_cast<DeclContext>(*D)) { 2736 if (InnerCtx->isTransparentContext() || InnerCtx->isInlineNamespace()) 2737 LookupVisibleDecls(InnerCtx, Result, QualifiedNameLookup, InBaseClass, 2738 Consumer, Visited); 2739 } 2740 } 2741 } 2742 2743 // Traverse using directives for qualified name lookup. 2744 if (QualifiedNameLookup) { 2745 ShadowContextRAII Shadow(Visited); 2746 DeclContext::udir_iterator I, E; 2747 for (llvm::tie(I, E) = Ctx->getUsingDirectives(); I != E; ++I) { 2748 LookupVisibleDecls((*I)->getNominatedNamespace(), Result, 2749 QualifiedNameLookup, InBaseClass, Consumer, Visited); 2750 } 2751 } 2752 2753 // Traverse the contexts of inherited C++ classes. 2754 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) { 2755 if (!Record->hasDefinition()) 2756 return; 2757 2758 for (CXXRecordDecl::base_class_iterator B = Record->bases_begin(), 2759 BEnd = Record->bases_end(); 2760 B != BEnd; ++B) { 2761 QualType BaseType = B->getType(); 2762 2763 // Don't look into dependent bases, because name lookup can't look 2764 // there anyway. 2765 if (BaseType->isDependentType()) 2766 continue; 2767 2768 const RecordType *Record = BaseType->getAs<RecordType>(); 2769 if (!Record) 2770 continue; 2771 2772 // FIXME: It would be nice to be able to determine whether referencing 2773 // a particular member would be ambiguous. For example, given 2774 // 2775 // struct A { int member; }; 2776 // struct B { int member; }; 2777 // struct C : A, B { }; 2778 // 2779 // void f(C *c) { c->### } 2780 // 2781 // accessing 'member' would result in an ambiguity. However, we 2782 // could be smart enough to qualify the member with the base 2783 // class, e.g., 2784 // 2785 // c->B::member 2786 // 2787 // or 2788 // 2789 // c->A::member 2790 2791 // Find results in this base class (and its bases). 2792 ShadowContextRAII Shadow(Visited); 2793 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup, 2794 true, Consumer, Visited); 2795 } 2796 } 2797 2798 // Traverse the contexts of Objective-C classes. 2799 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) { 2800 // Traverse categories. 2801 for (ObjCCategoryDecl *Category = IFace->getCategoryList(); 2802 Category; Category = Category->getNextClassCategory()) { 2803 ShadowContextRAII Shadow(Visited); 2804 LookupVisibleDecls(Category, Result, QualifiedNameLookup, false, 2805 Consumer, Visited); 2806 } 2807 2808 // Traverse protocols. 2809 for (ObjCInterfaceDecl::all_protocol_iterator 2810 I = IFace->all_referenced_protocol_begin(), 2811 E = IFace->all_referenced_protocol_end(); I != E; ++I) { 2812 ShadowContextRAII Shadow(Visited); 2813 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2814 Visited); 2815 } 2816 2817 // Traverse the superclass. 2818 if (IFace->getSuperClass()) { 2819 ShadowContextRAII Shadow(Visited); 2820 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup, 2821 true, Consumer, Visited); 2822 } 2823 2824 // If there is an implementation, traverse it. We do this to find 2825 // synthesized ivars. 2826 if (IFace->getImplementation()) { 2827 ShadowContextRAII Shadow(Visited); 2828 LookupVisibleDecls(IFace->getImplementation(), Result, 2829 QualifiedNameLookup, true, Consumer, Visited); 2830 } 2831 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) { 2832 for (ObjCProtocolDecl::protocol_iterator I = Protocol->protocol_begin(), 2833 E = Protocol->protocol_end(); I != E; ++I) { 2834 ShadowContextRAII Shadow(Visited); 2835 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2836 Visited); 2837 } 2838 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) { 2839 for (ObjCCategoryDecl::protocol_iterator I = Category->protocol_begin(), 2840 E = Category->protocol_end(); I != E; ++I) { 2841 ShadowContextRAII Shadow(Visited); 2842 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer, 2843 Visited); 2844 } 2845 2846 // If there is an implementation, traverse it. 2847 if (Category->getImplementation()) { 2848 ShadowContextRAII Shadow(Visited); 2849 LookupVisibleDecls(Category->getImplementation(), Result, 2850 QualifiedNameLookup, true, Consumer, Visited); 2851 } 2852 } 2853 } 2854 2855 static void LookupVisibleDecls(Scope *S, LookupResult &Result, 2856 UnqualUsingDirectiveSet &UDirs, 2857 VisibleDeclConsumer &Consumer, 2858 VisibleDeclsRecord &Visited) { 2859 if (!S) 2860 return; 2861 2862 if (!S->getEntity() || 2863 (!S->getParent() && 2864 !Visited.alreadyVisitedContext((DeclContext *)S->getEntity())) || 2865 ((DeclContext *)S->getEntity())->isFunctionOrMethod()) { 2866 // Walk through the declarations in this Scope. 2867 for (Scope::decl_iterator D = S->decl_begin(), DEnd = S->decl_end(); 2868 D != DEnd; ++D) { 2869 if (NamedDecl *ND = dyn_cast<NamedDecl>(*D)) 2870 if (Result.isAcceptableDecl(ND)) { 2871 Consumer.FoundDecl(ND, Visited.checkHidden(ND), 0, false); 2872 Visited.add(ND); 2873 } 2874 } 2875 } 2876 2877 // FIXME: C++ [temp.local]p8 2878 DeclContext *Entity = 0; 2879 if (S->getEntity()) { 2880 // Look into this scope's declaration context, along with any of its 2881 // parent lookup contexts (e.g., enclosing classes), up to the point 2882 // where we hit the context stored in the next outer scope. 2883 Entity = (DeclContext *)S->getEntity(); 2884 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME 2885 2886 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx); 2887 Ctx = Ctx->getLookupParent()) { 2888 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 2889 if (Method->isInstanceMethod()) { 2890 // For instance methods, look for ivars in the method's interface. 2891 LookupResult IvarResult(Result.getSema(), Result.getLookupName(), 2892 Result.getNameLoc(), Sema::LookupMemberName); 2893 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) { 2894 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false, 2895 /*InBaseClass=*/false, Consumer, Visited); 2896 } 2897 } 2898 2899 // We've already performed all of the name lookup that we need 2900 // to for Objective-C methods; the next context will be the 2901 // outer scope. 2902 break; 2903 } 2904 2905 if (Ctx->isFunctionOrMethod()) 2906 continue; 2907 2908 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false, 2909 /*InBaseClass=*/false, Consumer, Visited); 2910 } 2911 } else if (!S->getParent()) { 2912 // Look into the translation unit scope. We walk through the translation 2913 // unit's declaration context, because the Scope itself won't have all of 2914 // the declarations if we loaded a precompiled header. 2915 // FIXME: We would like the translation unit's Scope object to point to the 2916 // translation unit, so we don't need this special "if" branch. However, 2917 // doing so would force the normal C++ name-lookup code to look into the 2918 // translation unit decl when the IdentifierInfo chains would suffice. 2919 // Once we fix that problem (which is part of a more general "don't look 2920 // in DeclContexts unless we have to" optimization), we can eliminate this. 2921 Entity = Result.getSema().Context.getTranslationUnitDecl(); 2922 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false, 2923 /*InBaseClass=*/false, Consumer, Visited); 2924 } 2925 2926 if (Entity) { 2927 // Lookup visible declarations in any namespaces found by using 2928 // directives. 2929 UnqualUsingDirectiveSet::const_iterator UI, UEnd; 2930 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(Entity); 2931 for (; UI != UEnd; ++UI) 2932 LookupVisibleDecls(const_cast<DeclContext *>(UI->getNominatedNamespace()), 2933 Result, /*QualifiedNameLookup=*/false, 2934 /*InBaseClass=*/false, Consumer, Visited); 2935 } 2936 2937 // Lookup names in the parent scope. 2938 ShadowContextRAII Shadow(Visited); 2939 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited); 2940 } 2941 2942 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind, 2943 VisibleDeclConsumer &Consumer, 2944 bool IncludeGlobalScope) { 2945 // Determine the set of using directives available during 2946 // unqualified name lookup. 2947 Scope *Initial = S; 2948 UnqualUsingDirectiveSet UDirs; 2949 if (getLangOptions().CPlusPlus) { 2950 // Find the first namespace or translation-unit scope. 2951 while (S && !isNamespaceOrTranslationUnitScope(S)) 2952 S = S->getParent(); 2953 2954 UDirs.visitScopeChain(Initial, S); 2955 } 2956 UDirs.done(); 2957 2958 // Look for visible declarations. 2959 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2960 VisibleDeclsRecord Visited; 2961 if (!IncludeGlobalScope) 2962 Visited.visitedContext(Context.getTranslationUnitDecl()); 2963 ShadowContextRAII Shadow(Visited); 2964 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited); 2965 } 2966 2967 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind, 2968 VisibleDeclConsumer &Consumer, 2969 bool IncludeGlobalScope) { 2970 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 2971 VisibleDeclsRecord Visited; 2972 if (!IncludeGlobalScope) 2973 Visited.visitedContext(Context.getTranslationUnitDecl()); 2974 ShadowContextRAII Shadow(Visited); 2975 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true, 2976 /*InBaseClass=*/false, Consumer, Visited); 2977 } 2978 2979 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name. 2980 /// If GnuLabelLoc is a valid source location, then this is a definition 2981 /// of an __label__ label name, otherwise it is a normal label definition 2982 /// or use. 2983 LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc, 2984 SourceLocation GnuLabelLoc) { 2985 // Do a lookup to see if we have a label with this name already. 2986 NamedDecl *Res = 0; 2987 2988 if (GnuLabelLoc.isValid()) { 2989 // Local label definitions always shadow existing labels. 2990 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc); 2991 Scope *S = CurScope; 2992 PushOnScopeChains(Res, S, true); 2993 return cast<LabelDecl>(Res); 2994 } 2995 2996 // Not a GNU local label. 2997 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration); 2998 // If we found a label, check to see if it is in the same context as us. 2999 // When in a Block, we don't want to reuse a label in an enclosing function. 3000 if (Res && Res->getDeclContext() != CurContext) 3001 Res = 0; 3002 if (Res == 0) { 3003 // If not forward referenced or defined already, create the backing decl. 3004 Res = LabelDecl::Create(Context, CurContext, Loc, II); 3005 Scope *S = CurScope->getFnParent(); 3006 assert(S && "Not in a function?"); 3007 PushOnScopeChains(Res, S, true); 3008 } 3009 return cast<LabelDecl>(Res); 3010 } 3011 3012 //===----------------------------------------------------------------------===// 3013 // Typo correction 3014 //===----------------------------------------------------------------------===// 3015 3016 namespace { 3017 3018 typedef llvm::StringMap<TypoCorrection, llvm::BumpPtrAllocator> TypoResultsMap; 3019 typedef std::map<unsigned, TypoResultsMap *> TypoEditDistanceMap; 3020 3021 static const unsigned MaxTypoDistanceResultSets = 5; 3022 3023 class TypoCorrectionConsumer : public VisibleDeclConsumer { 3024 /// \brief The name written that is a typo in the source. 3025 StringRef Typo; 3026 3027 /// \brief The results found that have the smallest edit distance 3028 /// found (so far) with the typo name. 3029 /// 3030 /// The pointer value being set to the current DeclContext indicates 3031 /// whether there is a keyword with this name. 3032 TypoEditDistanceMap BestResults; 3033 3034 /// \brief The worst of the best N edit distances found so far. 3035 unsigned MaxEditDistance; 3036 3037 Sema &SemaRef; 3038 3039 public: 3040 explicit TypoCorrectionConsumer(Sema &SemaRef, IdentifierInfo *Typo) 3041 : Typo(Typo->getName()), 3042 MaxEditDistance((std::numeric_limits<unsigned>::max)()), 3043 SemaRef(SemaRef) { } 3044 3045 ~TypoCorrectionConsumer() { 3046 for (TypoEditDistanceMap::iterator I = BestResults.begin(), 3047 IEnd = BestResults.end(); 3048 I != IEnd; 3049 ++I) 3050 delete I->second; 3051 } 3052 3053 virtual void FoundDecl(NamedDecl *ND, NamedDecl *Hiding, DeclContext *Ctx, 3054 bool InBaseClass); 3055 void FoundName(StringRef Name); 3056 void addKeywordResult(StringRef Keyword); 3057 void addName(StringRef Name, NamedDecl *ND, unsigned Distance, 3058 NestedNameSpecifier *NNS=NULL, bool isKeyword=false); 3059 void addCorrection(TypoCorrection Correction); 3060 3061 typedef TypoResultsMap::iterator result_iterator; 3062 typedef TypoEditDistanceMap::iterator distance_iterator; 3063 distance_iterator begin() { return BestResults.begin(); } 3064 distance_iterator end() { return BestResults.end(); } 3065 void erase(distance_iterator I) { BestResults.erase(I); } 3066 unsigned size() const { return BestResults.size(); } 3067 bool empty() const { return BestResults.empty(); } 3068 3069 TypoCorrection &operator[](StringRef Name) { 3070 return (*BestResults.begin()->second)[Name]; 3071 } 3072 3073 unsigned getMaxEditDistance() const { 3074 return MaxEditDistance; 3075 } 3076 3077 unsigned getBestEditDistance() { 3078 return (BestResults.empty()) ? MaxEditDistance : BestResults.begin()->first; 3079 } 3080 }; 3081 3082 } 3083 3084 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding, 3085 DeclContext *Ctx, bool InBaseClass) { 3086 // Don't consider hidden names for typo correction. 3087 if (Hiding) 3088 return; 3089 3090 // Only consider entities with identifiers for names, ignoring 3091 // special names (constructors, overloaded operators, selectors, 3092 // etc.). 3093 IdentifierInfo *Name = ND->getIdentifier(); 3094 if (!Name) 3095 return; 3096 3097 FoundName(Name->getName()); 3098 } 3099 3100 void TypoCorrectionConsumer::FoundName(StringRef Name) { 3101 // Use a simple length-based heuristic to determine the minimum possible 3102 // edit distance. If the minimum isn't good enough, bail out early. 3103 unsigned MinED = abs((int)Name.size() - (int)Typo.size()); 3104 if (MinED > MaxEditDistance || (MinED && Typo.size() / MinED < 3)) 3105 return; 3106 3107 // Compute an upper bound on the allowable edit distance, so that the 3108 // edit-distance algorithm can short-circuit. 3109 unsigned UpperBound = 3110 std::min(unsigned((Typo.size() + 2) / 3), MaxEditDistance); 3111 3112 // Compute the edit distance between the typo and the name of this 3113 // entity. If this edit distance is not worse than the best edit 3114 // distance we've seen so far, add it to the list of results. 3115 unsigned ED = Typo.edit_distance(Name, true, UpperBound); 3116 3117 if (ED > MaxEditDistance) { 3118 // This result is worse than the best results we've seen so far; 3119 // ignore it. 3120 return; 3121 } 3122 3123 addName(Name, NULL, ED); 3124 } 3125 3126 void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) { 3127 // Compute the edit distance between the typo and this keyword. 3128 // If this edit distance is not worse than the best edit 3129 // distance we've seen so far, add it to the list of results. 3130 unsigned ED = Typo.edit_distance(Keyword); 3131 if (ED > MaxEditDistance) { 3132 // This result is worse than the best results we've seen so far; 3133 // ignore it. 3134 return; 3135 } 3136 3137 addName(Keyword, NULL, ED, NULL, true); 3138 } 3139 3140 void TypoCorrectionConsumer::addName(StringRef Name, 3141 NamedDecl *ND, 3142 unsigned Distance, 3143 NestedNameSpecifier *NNS, 3144 bool isKeyword) { 3145 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, Distance); 3146 if (isKeyword) TC.makeKeyword(); 3147 addCorrection(TC); 3148 } 3149 3150 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) { 3151 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName(); 3152 TypoResultsMap *& Map = BestResults[Correction.getEditDistance()]; 3153 if (!Map) 3154 Map = new TypoResultsMap; 3155 3156 TypoCorrection &CurrentCorrection = (*Map)[Name]; 3157 if (!CurrentCorrection || 3158 // FIXME: The following should be rolled up into an operator< on 3159 // TypoCorrection with a more principled definition. 3160 CurrentCorrection.isKeyword() < Correction.isKeyword() || 3161 Correction.getAsString(SemaRef.getLangOptions()) < 3162 CurrentCorrection.getAsString(SemaRef.getLangOptions())) 3163 CurrentCorrection = Correction; 3164 3165 while (BestResults.size() > MaxTypoDistanceResultSets) { 3166 TypoEditDistanceMap::iterator Last = BestResults.end(); 3167 --Last; 3168 delete Last->second; 3169 BestResults.erase(Last); 3170 } 3171 } 3172 3173 namespace { 3174 3175 class SpecifierInfo { 3176 public: 3177 DeclContext* DeclCtx; 3178 NestedNameSpecifier* NameSpecifier; 3179 unsigned EditDistance; 3180 3181 SpecifierInfo(DeclContext *Ctx, NestedNameSpecifier *NNS, unsigned ED) 3182 : DeclCtx(Ctx), NameSpecifier(NNS), EditDistance(ED) {} 3183 }; 3184 3185 typedef SmallVector<DeclContext*, 4> DeclContextList; 3186 typedef SmallVector<SpecifierInfo, 16> SpecifierInfoList; 3187 3188 class NamespaceSpecifierSet { 3189 ASTContext &Context; 3190 DeclContextList CurContextChain; 3191 bool isSorted; 3192 3193 SpecifierInfoList Specifiers; 3194 llvm::SmallSetVector<unsigned, 4> Distances; 3195 llvm::DenseMap<unsigned, SpecifierInfoList> DistanceMap; 3196 3197 /// \brief Helper for building the list of DeclContexts between the current 3198 /// context and the top of the translation unit 3199 static DeclContextList BuildContextChain(DeclContext *Start); 3200 3201 void SortNamespaces(); 3202 3203 public: 3204 explicit NamespaceSpecifierSet(ASTContext &Context, DeclContext *CurContext) 3205 : Context(Context), CurContextChain(BuildContextChain(CurContext)), 3206 isSorted(true) {} 3207 3208 /// \brief Add the namespace to the set, computing the corresponding 3209 /// NestedNameSpecifier and its distance in the process. 3210 void AddNamespace(NamespaceDecl *ND); 3211 3212 typedef SpecifierInfoList::iterator iterator; 3213 iterator begin() { 3214 if (!isSorted) SortNamespaces(); 3215 return Specifiers.begin(); 3216 } 3217 iterator end() { return Specifiers.end(); } 3218 }; 3219 3220 } 3221 3222 DeclContextList NamespaceSpecifierSet::BuildContextChain(DeclContext *Start) { 3223 assert(Start && "Bulding a context chain from a null context"); 3224 DeclContextList Chain; 3225 for (DeclContext *DC = Start->getPrimaryContext(); DC != NULL; 3226 DC = DC->getLookupParent()) { 3227 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC); 3228 if (!DC->isInlineNamespace() && !DC->isTransparentContext() && 3229 !(ND && ND->isAnonymousNamespace())) 3230 Chain.push_back(DC->getPrimaryContext()); 3231 } 3232 return Chain; 3233 } 3234 3235 void NamespaceSpecifierSet::SortNamespaces() { 3236 SmallVector<unsigned, 4> sortedDistances; 3237 sortedDistances.append(Distances.begin(), Distances.end()); 3238 3239 if (sortedDistances.size() > 1) 3240 std::sort(sortedDistances.begin(), sortedDistances.end()); 3241 3242 Specifiers.clear(); 3243 for (SmallVector<unsigned, 4>::iterator DI = sortedDistances.begin(), 3244 DIEnd = sortedDistances.end(); 3245 DI != DIEnd; ++DI) { 3246 SpecifierInfoList &SpecList = DistanceMap[*DI]; 3247 Specifiers.append(SpecList.begin(), SpecList.end()); 3248 } 3249 3250 isSorted = true; 3251 } 3252 3253 void NamespaceSpecifierSet::AddNamespace(NamespaceDecl *ND) { 3254 DeclContext *Ctx = cast<DeclContext>(ND); 3255 NestedNameSpecifier *NNS = NULL; 3256 unsigned NumSpecifiers = 0; 3257 DeclContextList NamespaceDeclChain(BuildContextChain(Ctx)); 3258 3259 // Eliminate common elements from the two DeclContext chains 3260 for (DeclContextList::reverse_iterator C = CurContextChain.rbegin(), 3261 CEnd = CurContextChain.rend(); 3262 C != CEnd && !NamespaceDeclChain.empty() && 3263 NamespaceDeclChain.back() == *C; ++C) { 3264 NamespaceDeclChain.pop_back(); 3265 } 3266 3267 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain 3268 for (DeclContextList::reverse_iterator C = NamespaceDeclChain.rbegin(), 3269 CEnd = NamespaceDeclChain.rend(); 3270 C != CEnd; ++C) { 3271 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(*C); 3272 if (ND) { 3273 NNS = NestedNameSpecifier::Create(Context, NNS, ND); 3274 ++NumSpecifiers; 3275 } 3276 } 3277 3278 isSorted = false; 3279 Distances.insert(NumSpecifiers); 3280 DistanceMap[NumSpecifiers].push_back(SpecifierInfo(Ctx, NNS, NumSpecifiers)); 3281 } 3282 3283 /// \brief Perform name lookup for a possible result for typo correction. 3284 static void LookupPotentialTypoResult(Sema &SemaRef, 3285 LookupResult &Res, 3286 IdentifierInfo *Name, 3287 Scope *S, CXXScopeSpec *SS, 3288 DeclContext *MemberContext, 3289 bool EnteringContext, 3290 Sema::CorrectTypoContext CTC) { 3291 Res.suppressDiagnostics(); 3292 Res.clear(); 3293 Res.setLookupName(Name); 3294 if (MemberContext) { 3295 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) { 3296 if (CTC == Sema::CTC_ObjCIvarLookup) { 3297 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) { 3298 Res.addDecl(Ivar); 3299 Res.resolveKind(); 3300 return; 3301 } 3302 } 3303 3304 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(Name)) { 3305 Res.addDecl(Prop); 3306 Res.resolveKind(); 3307 return; 3308 } 3309 } 3310 3311 SemaRef.LookupQualifiedName(Res, MemberContext); 3312 return; 3313 } 3314 3315 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false, 3316 EnteringContext); 3317 3318 // Fake ivar lookup; this should really be part of 3319 // LookupParsedName. 3320 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) { 3321 if (Method->isInstanceMethod() && Method->getClassInterface() && 3322 (Res.empty() || 3323 (Res.isSingleResult() && 3324 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) { 3325 if (ObjCIvarDecl *IV 3326 = Method->getClassInterface()->lookupInstanceVariable(Name)) { 3327 Res.addDecl(IV); 3328 Res.resolveKind(); 3329 } 3330 } 3331 } 3332 } 3333 3334 /// \brief Add keywords to the consumer as possible typo corrections. 3335 static void AddKeywordsToConsumer(Sema &SemaRef, 3336 TypoCorrectionConsumer &Consumer, 3337 Scope *S, Sema::CorrectTypoContext CTC) { 3338 // Add context-dependent keywords. 3339 bool WantTypeSpecifiers = false; 3340 bool WantExpressionKeywords = false; 3341 bool WantCXXNamedCasts = false; 3342 bool WantRemainingKeywords = false; 3343 switch (CTC) { 3344 case Sema::CTC_Unknown: 3345 WantTypeSpecifiers = true; 3346 WantExpressionKeywords = true; 3347 WantCXXNamedCasts = true; 3348 WantRemainingKeywords = true; 3349 3350 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) 3351 if (Method->getClassInterface() && 3352 Method->getClassInterface()->getSuperClass()) 3353 Consumer.addKeywordResult("super"); 3354 3355 break; 3356 3357 case Sema::CTC_NoKeywords: 3358 break; 3359 3360 case Sema::CTC_Type: 3361 WantTypeSpecifiers = true; 3362 break; 3363 3364 case Sema::CTC_ObjCMessageReceiver: 3365 Consumer.addKeywordResult("super"); 3366 // Fall through to handle message receivers like expressions. 3367 3368 case Sema::CTC_Expression: 3369 if (SemaRef.getLangOptions().CPlusPlus) 3370 WantTypeSpecifiers = true; 3371 WantExpressionKeywords = true; 3372 // Fall through to get C++ named casts. 3373 3374 case Sema::CTC_CXXCasts: 3375 WantCXXNamedCasts = true; 3376 break; 3377 3378 case Sema::CTC_ObjCPropertyLookup: 3379 // FIXME: Add "isa"? 3380 break; 3381 3382 case Sema::CTC_MemberLookup: 3383 if (SemaRef.getLangOptions().CPlusPlus) 3384 Consumer.addKeywordResult("template"); 3385 break; 3386 3387 case Sema::CTC_ObjCIvarLookup: 3388 break; 3389 } 3390 3391 if (WantTypeSpecifiers) { 3392 // Add type-specifier keywords to the set of results. 3393 const char *CTypeSpecs[] = { 3394 "char", "const", "double", "enum", "float", "int", "long", "short", 3395 "signed", "struct", "union", "unsigned", "void", "volatile", 3396 "_Complex", "_Imaginary", 3397 // storage-specifiers as well 3398 "extern", "inline", "static", "typedef" 3399 }; 3400 3401 const unsigned NumCTypeSpecs = sizeof(CTypeSpecs) / sizeof(CTypeSpecs[0]); 3402 for (unsigned I = 0; I != NumCTypeSpecs; ++I) 3403 Consumer.addKeywordResult(CTypeSpecs[I]); 3404 3405 if (SemaRef.getLangOptions().C99) 3406 Consumer.addKeywordResult("restrict"); 3407 if (SemaRef.getLangOptions().Bool || SemaRef.getLangOptions().CPlusPlus) 3408 Consumer.addKeywordResult("bool"); 3409 else if (SemaRef.getLangOptions().C99) 3410 Consumer.addKeywordResult("_Bool"); 3411 3412 if (SemaRef.getLangOptions().CPlusPlus) { 3413 Consumer.addKeywordResult("class"); 3414 Consumer.addKeywordResult("typename"); 3415 Consumer.addKeywordResult("wchar_t"); 3416 3417 if (SemaRef.getLangOptions().CPlusPlus0x) { 3418 Consumer.addKeywordResult("char16_t"); 3419 Consumer.addKeywordResult("char32_t"); 3420 Consumer.addKeywordResult("constexpr"); 3421 Consumer.addKeywordResult("decltype"); 3422 Consumer.addKeywordResult("thread_local"); 3423 } 3424 } 3425 3426 if (SemaRef.getLangOptions().GNUMode) 3427 Consumer.addKeywordResult("typeof"); 3428 } 3429 3430 if (WantCXXNamedCasts && SemaRef.getLangOptions().CPlusPlus) { 3431 Consumer.addKeywordResult("const_cast"); 3432 Consumer.addKeywordResult("dynamic_cast"); 3433 Consumer.addKeywordResult("reinterpret_cast"); 3434 Consumer.addKeywordResult("static_cast"); 3435 } 3436 3437 if (WantExpressionKeywords) { 3438 Consumer.addKeywordResult("sizeof"); 3439 if (SemaRef.getLangOptions().Bool || SemaRef.getLangOptions().CPlusPlus) { 3440 Consumer.addKeywordResult("false"); 3441 Consumer.addKeywordResult("true"); 3442 } 3443 3444 if (SemaRef.getLangOptions().CPlusPlus) { 3445 const char *CXXExprs[] = { 3446 "delete", "new", "operator", "throw", "typeid" 3447 }; 3448 const unsigned NumCXXExprs = sizeof(CXXExprs) / sizeof(CXXExprs[0]); 3449 for (unsigned I = 0; I != NumCXXExprs; ++I) 3450 Consumer.addKeywordResult(CXXExprs[I]); 3451 3452 if (isa<CXXMethodDecl>(SemaRef.CurContext) && 3453 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance()) 3454 Consumer.addKeywordResult("this"); 3455 3456 if (SemaRef.getLangOptions().CPlusPlus0x) { 3457 Consumer.addKeywordResult("alignof"); 3458 Consumer.addKeywordResult("nullptr"); 3459 } 3460 } 3461 } 3462 3463 if (WantRemainingKeywords) { 3464 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) { 3465 // Statements. 3466 const char *CStmts[] = { 3467 "do", "else", "for", "goto", "if", "return", "switch", "while" }; 3468 const unsigned NumCStmts = sizeof(CStmts) / sizeof(CStmts[0]); 3469 for (unsigned I = 0; I != NumCStmts; ++I) 3470 Consumer.addKeywordResult(CStmts[I]); 3471 3472 if (SemaRef.getLangOptions().CPlusPlus) { 3473 Consumer.addKeywordResult("catch"); 3474 Consumer.addKeywordResult("try"); 3475 } 3476 3477 if (S && S->getBreakParent()) 3478 Consumer.addKeywordResult("break"); 3479 3480 if (S && S->getContinueParent()) 3481 Consumer.addKeywordResult("continue"); 3482 3483 if (!SemaRef.getCurFunction()->SwitchStack.empty()) { 3484 Consumer.addKeywordResult("case"); 3485 Consumer.addKeywordResult("default"); 3486 } 3487 } else { 3488 if (SemaRef.getLangOptions().CPlusPlus) { 3489 Consumer.addKeywordResult("namespace"); 3490 Consumer.addKeywordResult("template"); 3491 } 3492 3493 if (S && S->isClassScope()) { 3494 Consumer.addKeywordResult("explicit"); 3495 Consumer.addKeywordResult("friend"); 3496 Consumer.addKeywordResult("mutable"); 3497 Consumer.addKeywordResult("private"); 3498 Consumer.addKeywordResult("protected"); 3499 Consumer.addKeywordResult("public"); 3500 Consumer.addKeywordResult("virtual"); 3501 } 3502 } 3503 3504 if (SemaRef.getLangOptions().CPlusPlus) { 3505 Consumer.addKeywordResult("using"); 3506 3507 if (SemaRef.getLangOptions().CPlusPlus0x) 3508 Consumer.addKeywordResult("static_assert"); 3509 } 3510 } 3511 } 3512 3513 /// \brief Try to "correct" a typo in the source code by finding 3514 /// visible declarations whose names are similar to the name that was 3515 /// present in the source code. 3516 /// 3517 /// \param TypoName the \c DeclarationNameInfo structure that contains 3518 /// the name that was present in the source code along with its location. 3519 /// 3520 /// \param LookupKind the name-lookup criteria used to search for the name. 3521 /// 3522 /// \param S the scope in which name lookup occurs. 3523 /// 3524 /// \param SS the nested-name-specifier that precedes the name we're 3525 /// looking for, if present. 3526 /// 3527 /// \param MemberContext if non-NULL, the context in which to look for 3528 /// a member access expression. 3529 /// 3530 /// \param EnteringContext whether we're entering the context described by 3531 /// the nested-name-specifier SS. 3532 /// 3533 /// \param CTC The context in which typo correction occurs, which impacts the 3534 /// set of keywords permitted. 3535 /// 3536 /// \param OPT when non-NULL, the search for visible declarations will 3537 /// also walk the protocols in the qualified interfaces of \p OPT. 3538 /// 3539 /// \returns a \c TypoCorrection containing the corrected name if the typo 3540 /// along with information such as the \c NamedDecl where the corrected name 3541 /// was declared, and any additional \c NestedNameSpecifier needed to access 3542 /// it (C++ only). The \c TypoCorrection is empty if there is no correction. 3543 TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName, 3544 Sema::LookupNameKind LookupKind, 3545 Scope *S, CXXScopeSpec *SS, 3546 DeclContext *MemberContext, 3547 bool EnteringContext, 3548 CorrectTypoContext CTC, 3549 const ObjCObjectPointerType *OPT) { 3550 if (Diags.hasFatalErrorOccurred() || !getLangOptions().SpellChecking) 3551 return TypoCorrection(); 3552 3553 // We only attempt to correct typos for identifiers. 3554 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 3555 if (!Typo) 3556 return TypoCorrection(); 3557 3558 // If the scope specifier itself was invalid, don't try to correct 3559 // typos. 3560 if (SS && SS->isInvalid()) 3561 return TypoCorrection(); 3562 3563 // Never try to correct typos during template deduction or 3564 // instantiation. 3565 if (!ActiveTemplateInstantiations.empty()) 3566 return TypoCorrection(); 3567 3568 NamespaceSpecifierSet Namespaces(Context, CurContext); 3569 3570 TypoCorrectionConsumer Consumer(*this, Typo); 3571 3572 // Perform name lookup to find visible, similarly-named entities. 3573 bool IsUnqualifiedLookup = false; 3574 if (MemberContext) { 3575 LookupVisibleDecls(MemberContext, LookupKind, Consumer); 3576 3577 // Look in qualified interfaces. 3578 if (OPT) { 3579 for (ObjCObjectPointerType::qual_iterator 3580 I = OPT->qual_begin(), E = OPT->qual_end(); 3581 I != E; ++I) 3582 LookupVisibleDecls(*I, LookupKind, Consumer); 3583 } 3584 } else if (SS && SS->isSet()) { 3585 DeclContext *DC = computeDeclContext(*SS, EnteringContext); 3586 if (!DC) 3587 return TypoCorrection(); 3588 3589 // Provide a stop gap for files that are just seriously broken. Trying 3590 // to correct all typos can turn into a HUGE performance penalty, causing 3591 // some files to take minutes to get rejected by the parser. 3592 if (TyposCorrected + UnqualifiedTyposCorrected.size() >= 20) 3593 return TypoCorrection(); 3594 ++TyposCorrected; 3595 3596 LookupVisibleDecls(DC, LookupKind, Consumer); 3597 } else { 3598 IsUnqualifiedLookup = true; 3599 UnqualifiedTyposCorrectedMap::iterator Cached 3600 = UnqualifiedTyposCorrected.find(Typo); 3601 if (Cached == UnqualifiedTyposCorrected.end()) { 3602 // Provide a stop gap for files that are just seriously broken. Trying 3603 // to correct all typos can turn into a HUGE performance penalty, causing 3604 // some files to take minutes to get rejected by the parser. 3605 if (TyposCorrected + UnqualifiedTyposCorrected.size() >= 20) 3606 return TypoCorrection(); 3607 3608 // For unqualified lookup, look through all of the names that we have 3609 // seen in this translation unit. 3610 for (IdentifierTable::iterator I = Context.Idents.begin(), 3611 IEnd = Context.Idents.end(); 3612 I != IEnd; ++I) 3613 Consumer.FoundName(I->getKey()); 3614 3615 // Walk through identifiers in external identifier sources. 3616 if (IdentifierInfoLookup *External 3617 = Context.Idents.getExternalIdentifierLookup()) { 3618 llvm::OwningPtr<IdentifierIterator> Iter(External->getIdentifiers()); 3619 do { 3620 StringRef Name = Iter->Next(); 3621 if (Name.empty()) 3622 break; 3623 3624 Consumer.FoundName(Name); 3625 } while (true); 3626 } 3627 } else { 3628 // Use the cached value, unless it's a keyword. In the keyword case, we'll 3629 // end up adding the keyword below. 3630 if (!Cached->second) 3631 return TypoCorrection(); 3632 3633 if (!Cached->second.isKeyword()) 3634 Consumer.addCorrection(Cached->second); 3635 } 3636 } 3637 3638 AddKeywordsToConsumer(*this, Consumer, S, CTC); 3639 3640 // If we haven't found anything, we're done. 3641 if (Consumer.empty()) { 3642 // If this was an unqualified lookup, note that no correction was found. 3643 if (IsUnqualifiedLookup) 3644 (void)UnqualifiedTyposCorrected[Typo]; 3645 3646 return TypoCorrection(); 3647 } 3648 3649 // Make sure that the user typed at least 3 characters for each correction 3650 // made. Otherwise, we don't even both looking at the results. 3651 unsigned ED = Consumer.getBestEditDistance(); 3652 if (ED > 0 && Typo->getName().size() / ED < 3) { 3653 // If this was an unqualified lookup, note that no correction was found. 3654 if (IsUnqualifiedLookup) 3655 (void)UnqualifiedTyposCorrected[Typo]; 3656 3657 return TypoCorrection(); 3658 } 3659 3660 // Build the NestedNameSpecifiers for the KnownNamespaces 3661 if (getLangOptions().CPlusPlus) { 3662 // Load any externally-known namespaces. 3663 if (ExternalSource && !LoadedExternalKnownNamespaces) { 3664 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces; 3665 LoadedExternalKnownNamespaces = true; 3666 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces); 3667 for (unsigned I = 0, N = ExternalKnownNamespaces.size(); I != N; ++I) 3668 KnownNamespaces[ExternalKnownNamespaces[I]] = true; 3669 } 3670 3671 for (llvm::DenseMap<NamespaceDecl*, bool>::iterator 3672 KNI = KnownNamespaces.begin(), 3673 KNIEnd = KnownNamespaces.end(); 3674 KNI != KNIEnd; ++KNI) 3675 Namespaces.AddNamespace(KNI->first); 3676 } 3677 3678 // Weed out any names that could not be found by name lookup. 3679 llvm::SmallPtrSet<IdentifierInfo*, 16> QualifiedResults; 3680 LookupResult TmpRes(*this, TypoName, LookupKind); 3681 TmpRes.suppressDiagnostics(); 3682 while (!Consumer.empty()) { 3683 TypoCorrectionConsumer::distance_iterator DI = Consumer.begin(); 3684 unsigned ED = DI->first; 3685 for (TypoCorrectionConsumer::result_iterator I = DI->second->begin(), 3686 IEnd = DI->second->end(); 3687 I != IEnd; /* Increment in loop. */) { 3688 // If the item already has been looked up or is a keyword, keep it 3689 if (I->second.isResolved()) { 3690 ++I; 3691 continue; 3692 } 3693 3694 // Perform name lookup on this name. 3695 IdentifierInfo *Name = I->second.getCorrectionAsIdentifierInfo(); 3696 LookupPotentialTypoResult(*this, TmpRes, Name, S, SS, MemberContext, 3697 EnteringContext, CTC); 3698 3699 switch (TmpRes.getResultKind()) { 3700 case LookupResult::NotFound: 3701 case LookupResult::NotFoundInCurrentInstantiation: 3702 case LookupResult::FoundUnresolvedValue: 3703 QualifiedResults.insert(Name); 3704 // We didn't find this name in our scope, or didn't like what we found; 3705 // ignore it. 3706 { 3707 TypoCorrectionConsumer::result_iterator Next = I; 3708 ++Next; 3709 DI->second->erase(I); 3710 I = Next; 3711 } 3712 break; 3713 3714 case LookupResult::Ambiguous: 3715 // We don't deal with ambiguities. 3716 return TypoCorrection(); 3717 3718 case LookupResult::FoundOverloaded: { 3719 // Store all of the Decls for overloaded symbols 3720 for (LookupResult::iterator TRD = TmpRes.begin(), 3721 TRDEnd = TmpRes.end(); 3722 TRD != TRDEnd; ++TRD) 3723 I->second.addCorrectionDecl(*TRD); 3724 ++I; 3725 break; 3726 } 3727 3728 case LookupResult::Found: 3729 I->second.setCorrectionDecl(TmpRes.getAsSingle<NamedDecl>()); 3730 ++I; 3731 break; 3732 } 3733 } 3734 3735 if (DI->second->empty()) 3736 Consumer.erase(DI); 3737 else if (!getLangOptions().CPlusPlus || QualifiedResults.empty() || !ED) 3738 // If there are results in the closest possible bucket, stop 3739 break; 3740 3741 // Only perform the qualified lookups for C++ 3742 if (getLangOptions().CPlusPlus) { 3743 TmpRes.suppressDiagnostics(); 3744 for (llvm::SmallPtrSet<IdentifierInfo*, 3745 16>::iterator QRI = QualifiedResults.begin(), 3746 QRIEnd = QualifiedResults.end(); 3747 QRI != QRIEnd; ++QRI) { 3748 for (NamespaceSpecifierSet::iterator NI = Namespaces.begin(), 3749 NIEnd = Namespaces.end(); 3750 NI != NIEnd; ++NI) { 3751 DeclContext *Ctx = NI->DeclCtx; 3752 unsigned QualifiedED = ED + NI->EditDistance; 3753 3754 // Stop searching once the namespaces are too far away to create 3755 // acceptable corrections for this identifier (since the namespaces 3756 // are sorted in ascending order by edit distance) 3757 if (QualifiedED > Consumer.getMaxEditDistance()) break; 3758 3759 TmpRes.clear(); 3760 TmpRes.setLookupName(*QRI); 3761 if (!LookupQualifiedName(TmpRes, Ctx)) continue; 3762 3763 switch (TmpRes.getResultKind()) { 3764 case LookupResult::Found: 3765 Consumer.addName((*QRI)->getName(), TmpRes.getAsSingle<NamedDecl>(), 3766 QualifiedED, NI->NameSpecifier); 3767 break; 3768 case LookupResult::FoundOverloaded: { 3769 TypoCorrection corr(&Context.Idents.get((*QRI)->getName()), NULL, 3770 NI->NameSpecifier, QualifiedED); 3771 for (LookupResult::iterator TRD = TmpRes.begin(), 3772 TRDEnd = TmpRes.end(); 3773 TRD != TRDEnd; ++TRD) 3774 corr.addCorrectionDecl(*TRD); 3775 Consumer.addCorrection(corr); 3776 break; 3777 } 3778 case LookupResult::NotFound: 3779 case LookupResult::NotFoundInCurrentInstantiation: 3780 case LookupResult::Ambiguous: 3781 case LookupResult::FoundUnresolvedValue: 3782 break; 3783 } 3784 } 3785 } 3786 } 3787 3788 QualifiedResults.clear(); 3789 } 3790 3791 // No corrections remain... 3792 if (Consumer.empty()) return TypoCorrection(); 3793 3794 TypoResultsMap &BestResults = *Consumer.begin()->second; 3795 ED = Consumer.begin()->first; 3796 3797 if (ED > 0 && Typo->getName().size() / ED < 3) { 3798 // If this was an unqualified lookup, note that no correction was found. 3799 if (IsUnqualifiedLookup) 3800 (void)UnqualifiedTyposCorrected[Typo]; 3801 3802 return TypoCorrection(); 3803 } 3804 3805 // If we have multiple possible corrections, eliminate the ones where we 3806 // added namespace qualifiers to try to resolve the ambiguity (and to favor 3807 // corrections without additional namespace qualifiers) 3808 if (getLangOptions().CPlusPlus && BestResults.size() > 1) { 3809 TypoCorrectionConsumer::distance_iterator DI = Consumer.begin(); 3810 for (TypoCorrectionConsumer::result_iterator I = DI->second->begin(), 3811 IEnd = DI->second->end(); 3812 I != IEnd; /* Increment in loop. */) { 3813 if (I->second.getCorrectionSpecifier() != NULL) { 3814 TypoCorrectionConsumer::result_iterator Cur = I; 3815 ++I; 3816 DI->second->erase(Cur); 3817 } else ++I; 3818 } 3819 } 3820 3821 // If only a single name remains, return that result. 3822 if (BestResults.size() == 1) { 3823 const llvm::StringMapEntry<TypoCorrection> &Correction = *(BestResults.begin()); 3824 const TypoCorrection &Result = Correction.second; 3825 3826 // Don't correct to a keyword that's the same as the typo; the keyword 3827 // wasn't actually in scope. 3828 if (ED == 0 && Result.isKeyword()) return TypoCorrection(); 3829 3830 // Record the correction for unqualified lookup. 3831 if (IsUnqualifiedLookup) 3832 UnqualifiedTyposCorrected[Typo] = Result; 3833 3834 return Result; 3835 } 3836 else if (BestResults.size() > 1 && CTC == CTC_ObjCMessageReceiver 3837 && BestResults["super"].isKeyword()) { 3838 // Prefer 'super' when we're completing in a message-receiver 3839 // context. 3840 3841 // Don't correct to a keyword that's the same as the typo; the keyword 3842 // wasn't actually in scope. 3843 if (ED == 0) return TypoCorrection(); 3844 3845 // Record the correction for unqualified lookup. 3846 if (IsUnqualifiedLookup) 3847 UnqualifiedTyposCorrected[Typo] = BestResults["super"]; 3848 3849 return BestResults["super"]; 3850 } 3851 3852 if (IsUnqualifiedLookup) 3853 (void)UnqualifiedTyposCorrected[Typo]; 3854 3855 return TypoCorrection(); 3856 } 3857 3858 void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) { 3859 if (!CDecl) return; 3860 3861 if (isKeyword()) 3862 CorrectionDecls.clear(); 3863 3864 CorrectionDecls.push_back(CDecl); 3865 3866 if (!CorrectionName) 3867 CorrectionName = CDecl->getDeclName(); 3868 } 3869 3870 std::string TypoCorrection::getAsString(const LangOptions &LO) const { 3871 if (CorrectionNameSpec) { 3872 std::string tmpBuffer; 3873 llvm::raw_string_ostream PrefixOStream(tmpBuffer); 3874 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO)); 3875 return PrefixOStream.str() + CorrectionName.getAsString(); 3876 } 3877 3878 return CorrectionName.getAsString(); 3879 } 3880