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/Lookup.h" 15 #include "clang/AST/ASTContext.h" 16 #include "clang/AST/CXXInheritance.h" 17 #include "clang/AST/Decl.h" 18 #include "clang/AST/DeclCXX.h" 19 #include "clang/AST/DeclLookups.h" 20 #include "clang/AST/DeclObjC.h" 21 #include "clang/AST/DeclTemplate.h" 22 #include "clang/AST/Expr.h" 23 #include "clang/AST/ExprCXX.h" 24 #include "clang/Basic/Builtins.h" 25 #include "clang/Basic/LangOptions.h" 26 #include "clang/Lex/ModuleLoader.h" 27 #include "clang/Sema/DeclSpec.h" 28 #include "clang/Sema/ExternalSemaSource.h" 29 #include "clang/Sema/Overload.h" 30 #include "clang/Sema/Scope.h" 31 #include "clang/Sema/ScopeInfo.h" 32 #include "clang/Sema/Sema.h" 33 #include "clang/Sema/SemaInternal.h" 34 #include "clang/Sema/TemplateDeduction.h" 35 #include "clang/Sema/TypoCorrection.h" 36 #include "llvm/ADT/STLExtras.h" 37 #include "llvm/ADT/SetVector.h" 38 #include "llvm/ADT/SmallPtrSet.h" 39 #include "llvm/ADT/StringMap.h" 40 #include "llvm/ADT/TinyPtrVector.h" 41 #include "llvm/ADT/edit_distance.h" 42 #include "llvm/Support/ErrorHandling.h" 43 #include <algorithm> 44 #include <iterator> 45 #include <limits> 46 #include <list> 47 #include <map> 48 #include <set> 49 #include <utility> 50 #include <vector> 51 52 using namespace clang; 53 using namespace sema; 54 55 namespace { 56 class UnqualUsingEntry { 57 const DeclContext *Nominated; 58 const DeclContext *CommonAncestor; 59 60 public: 61 UnqualUsingEntry(const DeclContext *Nominated, 62 const DeclContext *CommonAncestor) 63 : Nominated(Nominated), CommonAncestor(CommonAncestor) { 64 } 65 66 const DeclContext *getCommonAncestor() const { 67 return CommonAncestor; 68 } 69 70 const DeclContext *getNominatedNamespace() const { 71 return Nominated; 72 } 73 74 // Sort by the pointer value of the common ancestor. 75 struct Comparator { 76 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) { 77 return L.getCommonAncestor() < R.getCommonAncestor(); 78 } 79 80 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) { 81 return E.getCommonAncestor() < DC; 82 } 83 84 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) { 85 return DC < E.getCommonAncestor(); 86 } 87 }; 88 }; 89 90 /// A collection of using directives, as used by C++ unqualified 91 /// lookup. 92 class UnqualUsingDirectiveSet { 93 typedef SmallVector<UnqualUsingEntry, 8> ListTy; 94 95 ListTy list; 96 llvm::SmallPtrSet<DeclContext*, 8> visited; 97 98 public: 99 UnqualUsingDirectiveSet() {} 100 101 void visitScopeChain(Scope *S, Scope *InnermostFileScope) { 102 // C++ [namespace.udir]p1: 103 // During unqualified name lookup, the names appear as if they 104 // were declared in the nearest enclosing namespace which contains 105 // both the using-directive and the nominated namespace. 106 DeclContext *InnermostFileDC = InnermostFileScope->getEntity(); 107 assert(InnermostFileDC && InnermostFileDC->isFileContext()); 108 109 for (; S; S = S->getParent()) { 110 // C++ [namespace.udir]p1: 111 // A using-directive shall not appear in class scope, but may 112 // appear in namespace scope or in block scope. 113 DeclContext *Ctx = S->getEntity(); 114 if (Ctx && Ctx->isFileContext()) { 115 visit(Ctx, Ctx); 116 } else if (!Ctx || Ctx->isFunctionOrMethod()) { 117 for (auto *I : S->using_directives()) 118 visit(I, InnermostFileDC); 119 } 120 } 121 } 122 123 // Visits a context and collect all of its using directives 124 // recursively. Treats all using directives as if they were 125 // declared in the context. 126 // 127 // A given context is only every visited once, so it is important 128 // that contexts be visited from the inside out in order to get 129 // the effective DCs right. 130 void visit(DeclContext *DC, DeclContext *EffectiveDC) { 131 if (!visited.insert(DC).second) 132 return; 133 134 addUsingDirectives(DC, EffectiveDC); 135 } 136 137 // Visits a using directive and collects all of its using 138 // directives recursively. Treats all using directives as if they 139 // were declared in the effective DC. 140 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 141 DeclContext *NS = UD->getNominatedNamespace(); 142 if (!visited.insert(NS).second) 143 return; 144 145 addUsingDirective(UD, EffectiveDC); 146 addUsingDirectives(NS, EffectiveDC); 147 } 148 149 // Adds all the using directives in a context (and those nominated 150 // by its using directives, transitively) as if they appeared in 151 // the given effective context. 152 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) { 153 SmallVector<DeclContext*,4> queue; 154 while (true) { 155 for (auto UD : DC->using_directives()) { 156 DeclContext *NS = UD->getNominatedNamespace(); 157 if (visited.insert(NS).second) { 158 addUsingDirective(UD, EffectiveDC); 159 queue.push_back(NS); 160 } 161 } 162 163 if (queue.empty()) 164 return; 165 166 DC = queue.pop_back_val(); 167 } 168 } 169 170 // Add a using directive as if it had been declared in the given 171 // context. This helps implement C++ [namespace.udir]p3: 172 // The using-directive is transitive: if a scope contains a 173 // using-directive that nominates a second namespace that itself 174 // contains using-directives, the effect is as if the 175 // using-directives from the second namespace also appeared in 176 // the first. 177 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 178 // Find the common ancestor between the effective context and 179 // the nominated namespace. 180 DeclContext *Common = UD->getNominatedNamespace(); 181 while (!Common->Encloses(EffectiveDC)) 182 Common = Common->getParent(); 183 Common = Common->getPrimaryContext(); 184 185 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common)); 186 } 187 188 void done() { 189 std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator()); 190 } 191 192 typedef ListTy::const_iterator const_iterator; 193 194 const_iterator begin() const { return list.begin(); } 195 const_iterator end() const { return list.end(); } 196 197 llvm::iterator_range<const_iterator> 198 getNamespacesFor(DeclContext *DC) const { 199 return llvm::make_range(std::equal_range(begin(), end(), 200 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 case Sema::LookupLocalFriendName: 217 IDNS = Decl::IDNS_Ordinary; 218 if (CPlusPlus) { 219 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace; 220 if (Redeclaration) 221 IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend; 222 } 223 if (Redeclaration) 224 IDNS |= Decl::IDNS_LocalExtern; 225 break; 226 227 case Sema::LookupOperatorName: 228 // Operator lookup is its own crazy thing; it is not the same 229 // as (e.g.) looking up an operator name for redeclaration. 230 assert(!Redeclaration && "cannot do redeclaration operator lookup"); 231 IDNS = Decl::IDNS_NonMemberOperator; 232 break; 233 234 case Sema::LookupTagName: 235 if (CPlusPlus) { 236 IDNS = Decl::IDNS_Type; 237 238 // When looking for a redeclaration of a tag name, we add: 239 // 1) TagFriend to find undeclared friend decls 240 // 2) Namespace because they can't "overload" with tag decls. 241 // 3) Tag because it includes class templates, which can't 242 // "overload" with tag decls. 243 if (Redeclaration) 244 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace; 245 } else { 246 IDNS = Decl::IDNS_Tag; 247 } 248 break; 249 250 case Sema::LookupLabel: 251 IDNS = Decl::IDNS_Label; 252 break; 253 254 case Sema::LookupMemberName: 255 IDNS = Decl::IDNS_Member; 256 if (CPlusPlus) 257 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary; 258 break; 259 260 case Sema::LookupNestedNameSpecifierName: 261 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace; 262 break; 263 264 case Sema::LookupNamespaceName: 265 IDNS = Decl::IDNS_Namespace; 266 break; 267 268 case Sema::LookupUsingDeclName: 269 assert(Redeclaration && "should only be used for redecl lookup"); 270 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member | 271 Decl::IDNS_Using | Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend | 272 Decl::IDNS_LocalExtern; 273 break; 274 275 case Sema::LookupObjCProtocolName: 276 IDNS = Decl::IDNS_ObjCProtocol; 277 break; 278 279 case Sema::LookupAnyName: 280 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member 281 | Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol 282 | Decl::IDNS_Type; 283 break; 284 } 285 return IDNS; 286 } 287 288 void LookupResult::configure() { 289 IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus, 290 isForRedeclaration()); 291 292 // If we're looking for one of the allocation or deallocation 293 // operators, make sure that the implicitly-declared new and delete 294 // operators can be found. 295 switch (NameInfo.getName().getCXXOverloadedOperator()) { 296 case OO_New: 297 case OO_Delete: 298 case OO_Array_New: 299 case OO_Array_Delete: 300 getSema().DeclareGlobalNewDelete(); 301 break; 302 303 default: 304 break; 305 } 306 307 // Compiler builtins are always visible, regardless of where they end 308 // up being declared. 309 if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) { 310 if (unsigned BuiltinID = Id->getBuiltinID()) { 311 if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 312 AllowHidden = true; 313 } 314 } 315 } 316 317 bool LookupResult::sanity() const { 318 // This function is never called by NDEBUG builds. 319 assert(ResultKind != NotFound || Decls.size() == 0); 320 assert(ResultKind != Found || Decls.size() == 1); 321 assert(ResultKind != FoundOverloaded || Decls.size() > 1 || 322 (Decls.size() == 1 && 323 isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl()))); 324 assert(ResultKind != FoundUnresolvedValue || sanityCheckUnresolved()); 325 assert(ResultKind != Ambiguous || Decls.size() > 1 || 326 (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects || 327 Ambiguity == AmbiguousBaseSubobjectTypes))); 328 assert((Paths != nullptr) == (ResultKind == Ambiguous && 329 (Ambiguity == AmbiguousBaseSubobjectTypes || 330 Ambiguity == AmbiguousBaseSubobjects))); 331 return true; 332 } 333 334 // Necessary because CXXBasePaths is not complete in Sema.h 335 void LookupResult::deletePaths(CXXBasePaths *Paths) { 336 delete Paths; 337 } 338 339 /// Get a representative context for a declaration such that two declarations 340 /// will have the same context if they were found within the same scope. 341 static DeclContext *getContextForScopeMatching(Decl *D) { 342 // For function-local declarations, use that function as the context. This 343 // doesn't account for scopes within the function; the caller must deal with 344 // those. 345 DeclContext *DC = D->getLexicalDeclContext(); 346 if (DC->isFunctionOrMethod()) 347 return DC; 348 349 // Otherwise, look at the semantic context of the declaration. The 350 // declaration must have been found there. 351 return D->getDeclContext()->getRedeclContext(); 352 } 353 354 /// Resolves the result kind of this lookup. 355 void LookupResult::resolveKind() { 356 unsigned N = Decls.size(); 357 358 // Fast case: no possible ambiguity. 359 if (N == 0) { 360 assert(ResultKind == NotFound || ResultKind == NotFoundInCurrentInstantiation); 361 return; 362 } 363 364 // If there's a single decl, we need to examine it to decide what 365 // kind of lookup this is. 366 if (N == 1) { 367 NamedDecl *D = (*Decls.begin())->getUnderlyingDecl(); 368 if (isa<FunctionTemplateDecl>(D)) 369 ResultKind = FoundOverloaded; 370 else if (isa<UnresolvedUsingValueDecl>(D)) 371 ResultKind = FoundUnresolvedValue; 372 return; 373 } 374 375 // Don't do any extra resolution if we've already resolved as ambiguous. 376 if (ResultKind == Ambiguous) return; 377 378 llvm::SmallPtrSet<NamedDecl*, 16> Unique; 379 llvm::SmallPtrSet<QualType, 16> UniqueTypes; 380 381 bool Ambiguous = false; 382 bool HasTag = false, HasFunction = false, HasNonFunction = false; 383 bool HasFunctionTemplate = false, HasUnresolved = false; 384 385 unsigned UniqueTagIndex = 0; 386 387 unsigned I = 0; 388 while (I < N) { 389 NamedDecl *D = Decls[I]->getUnderlyingDecl(); 390 D = cast<NamedDecl>(D->getCanonicalDecl()); 391 392 // Ignore an invalid declaration unless it's the only one left. 393 if (D->isInvalidDecl() && I < N-1) { 394 Decls[I] = Decls[--N]; 395 continue; 396 } 397 398 // Redeclarations of types via typedef can occur both within a scope 399 // and, through using declarations and directives, across scopes. There is 400 // no ambiguity if they all refer to the same type, so unique based on the 401 // canonical type. 402 if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) { 403 if (!TD->getDeclContext()->isRecord()) { 404 QualType T = getSema().Context.getTypeDeclType(TD); 405 if (!UniqueTypes.insert(getSema().Context.getCanonicalType(T)).second) { 406 // The type is not unique; pull something off the back and continue 407 // at this index. 408 Decls[I] = Decls[--N]; 409 continue; 410 } 411 } 412 } 413 414 if (!Unique.insert(D).second) { 415 // If it's not unique, pull something off the back (and 416 // continue at this index). 417 // FIXME: This is wrong. We need to take the more recent declaration in 418 // order to get the right type, default arguments, etc. We also need to 419 // prefer visible declarations to hidden ones (for redeclaration lookup 420 // in modules builds). 421 Decls[I] = Decls[--N]; 422 continue; 423 } 424 425 // Otherwise, do some decl type analysis and then continue. 426 427 if (isa<UnresolvedUsingValueDecl>(D)) { 428 HasUnresolved = true; 429 } else if (isa<TagDecl>(D)) { 430 if (HasTag) 431 Ambiguous = true; 432 UniqueTagIndex = I; 433 HasTag = true; 434 } else if (isa<FunctionTemplateDecl>(D)) { 435 HasFunction = true; 436 HasFunctionTemplate = true; 437 } else if (isa<FunctionDecl>(D)) { 438 HasFunction = true; 439 } else { 440 if (HasNonFunction) 441 Ambiguous = true; 442 HasNonFunction = true; 443 } 444 I++; 445 } 446 447 // C++ [basic.scope.hiding]p2: 448 // A class name or enumeration name can be hidden by the name of 449 // an object, function, or enumerator declared in the same 450 // scope. If a class or enumeration name and an object, function, 451 // or enumerator are declared in the same scope (in any order) 452 // with the same name, the class or enumeration name is hidden 453 // wherever the object, function, or enumerator name is visible. 454 // But it's still an error if there are distinct tag types found, 455 // even if they're not visible. (ref?) 456 if (HideTags && HasTag && !Ambiguous && 457 (HasFunction || HasNonFunction || HasUnresolved)) { 458 if (getContextForScopeMatching(Decls[UniqueTagIndex])->Equals( 459 getContextForScopeMatching(Decls[UniqueTagIndex ? 0 : N - 1]))) 460 Decls[UniqueTagIndex] = Decls[--N]; 461 else 462 Ambiguous = true; 463 } 464 465 Decls.set_size(N); 466 467 if (HasNonFunction && (HasFunction || HasUnresolved)) 468 Ambiguous = true; 469 470 if (Ambiguous) 471 setAmbiguous(LookupResult::AmbiguousReference); 472 else if (HasUnresolved) 473 ResultKind = LookupResult::FoundUnresolvedValue; 474 else if (N > 1 || HasFunctionTemplate) 475 ResultKind = LookupResult::FoundOverloaded; 476 else 477 ResultKind = LookupResult::Found; 478 } 479 480 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) { 481 CXXBasePaths::const_paths_iterator I, E; 482 for (I = P.begin(), E = P.end(); I != E; ++I) 483 for (DeclContext::lookup_iterator DI = I->Decls.begin(), 484 DE = I->Decls.end(); DI != DE; ++DI) 485 addDecl(*DI); 486 } 487 488 void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) { 489 Paths = new CXXBasePaths; 490 Paths->swap(P); 491 addDeclsFromBasePaths(*Paths); 492 resolveKind(); 493 setAmbiguous(AmbiguousBaseSubobjects); 494 } 495 496 void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) { 497 Paths = new CXXBasePaths; 498 Paths->swap(P); 499 addDeclsFromBasePaths(*Paths); 500 resolveKind(); 501 setAmbiguous(AmbiguousBaseSubobjectTypes); 502 } 503 504 void LookupResult::print(raw_ostream &Out) { 505 Out << Decls.size() << " result(s)"; 506 if (isAmbiguous()) Out << ", ambiguous"; 507 if (Paths) Out << ", base paths present"; 508 509 for (iterator I = begin(), E = end(); I != E; ++I) { 510 Out << "\n"; 511 (*I)->print(Out, 2); 512 } 513 } 514 515 /// \brief Lookup a builtin function, when name lookup would otherwise 516 /// fail. 517 static bool LookupBuiltin(Sema &S, LookupResult &R) { 518 Sema::LookupNameKind NameKind = R.getLookupKind(); 519 520 // If we didn't find a use of this identifier, and if the identifier 521 // corresponds to a compiler builtin, create the decl object for the builtin 522 // now, injecting it into translation unit scope, and return it. 523 if (NameKind == Sema::LookupOrdinaryName || 524 NameKind == Sema::LookupRedeclarationWithLinkage) { 525 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo(); 526 if (II) { 527 if (S.getLangOpts().CPlusPlus11 && S.getLangOpts().GNUMode && 528 II == S.getFloat128Identifier()) { 529 // libstdc++4.7's type_traits expects type __float128 to exist, so 530 // insert a dummy type to make that header build in gnu++11 mode. 531 R.addDecl(S.getASTContext().getFloat128StubType()); 532 return true; 533 } 534 535 // If this is a builtin on this (or all) targets, create the decl. 536 if (unsigned BuiltinID = II->getBuiltinID()) { 537 // In C++, we don't have any predefined library functions like 538 // 'malloc'. Instead, we'll just error. 539 if (S.getLangOpts().CPlusPlus && 540 S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 541 return false; 542 543 if (NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II, 544 BuiltinID, S.TUScope, 545 R.isForRedeclaration(), 546 R.getNameLoc())) { 547 R.addDecl(D); 548 return true; 549 } 550 } 551 } 552 } 553 554 return false; 555 } 556 557 /// \brief Determine whether we can declare a special member function within 558 /// the class at this point. 559 static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) { 560 // We need to have a definition for the class. 561 if (!Class->getDefinition() || Class->isDependentContext()) 562 return false; 563 564 // We can't be in the middle of defining the class. 565 return !Class->isBeingDefined(); 566 } 567 568 void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) { 569 if (!CanDeclareSpecialMemberFunction(Class)) 570 return; 571 572 // If the default constructor has not yet been declared, do so now. 573 if (Class->needsImplicitDefaultConstructor()) 574 DeclareImplicitDefaultConstructor(Class); 575 576 // If the copy constructor has not yet been declared, do so now. 577 if (Class->needsImplicitCopyConstructor()) 578 DeclareImplicitCopyConstructor(Class); 579 580 // If the copy assignment operator has not yet been declared, do so now. 581 if (Class->needsImplicitCopyAssignment()) 582 DeclareImplicitCopyAssignment(Class); 583 584 if (getLangOpts().CPlusPlus11) { 585 // If the move constructor has not yet been declared, do so now. 586 if (Class->needsImplicitMoveConstructor()) 587 DeclareImplicitMoveConstructor(Class); // might not actually do it 588 589 // If the move assignment operator has not yet been declared, do so now. 590 if (Class->needsImplicitMoveAssignment()) 591 DeclareImplicitMoveAssignment(Class); // might not actually do it 592 } 593 594 // If the destructor has not yet been declared, do so now. 595 if (Class->needsImplicitDestructor()) 596 DeclareImplicitDestructor(Class); 597 } 598 599 /// \brief Determine whether this is the name of an implicitly-declared 600 /// special member function. 601 static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) { 602 switch (Name.getNameKind()) { 603 case DeclarationName::CXXConstructorName: 604 case DeclarationName::CXXDestructorName: 605 return true; 606 607 case DeclarationName::CXXOperatorName: 608 return Name.getCXXOverloadedOperator() == OO_Equal; 609 610 default: 611 break; 612 } 613 614 return false; 615 } 616 617 /// \brief If there are any implicit member functions with the given name 618 /// that need to be declared in the given declaration context, do so. 619 static void DeclareImplicitMemberFunctionsWithName(Sema &S, 620 DeclarationName Name, 621 const DeclContext *DC) { 622 if (!DC) 623 return; 624 625 switch (Name.getNameKind()) { 626 case DeclarationName::CXXConstructorName: 627 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) 628 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) { 629 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record); 630 if (Record->needsImplicitDefaultConstructor()) 631 S.DeclareImplicitDefaultConstructor(Class); 632 if (Record->needsImplicitCopyConstructor()) 633 S.DeclareImplicitCopyConstructor(Class); 634 if (S.getLangOpts().CPlusPlus11 && 635 Record->needsImplicitMoveConstructor()) 636 S.DeclareImplicitMoveConstructor(Class); 637 } 638 break; 639 640 case DeclarationName::CXXDestructorName: 641 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) 642 if (Record->getDefinition() && Record->needsImplicitDestructor() && 643 CanDeclareSpecialMemberFunction(Record)) 644 S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record)); 645 break; 646 647 case DeclarationName::CXXOperatorName: 648 if (Name.getCXXOverloadedOperator() != OO_Equal) 649 break; 650 651 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) { 652 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) { 653 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record); 654 if (Record->needsImplicitCopyAssignment()) 655 S.DeclareImplicitCopyAssignment(Class); 656 if (S.getLangOpts().CPlusPlus11 && 657 Record->needsImplicitMoveAssignment()) 658 S.DeclareImplicitMoveAssignment(Class); 659 } 660 } 661 break; 662 663 default: 664 break; 665 } 666 } 667 668 // Adds all qualifying matches for a name within a decl context to the 669 // given lookup result. Returns true if any matches were found. 670 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) { 671 bool Found = false; 672 673 // Lazily declare C++ special member functions. 674 if (S.getLangOpts().CPlusPlus) 675 DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), DC); 676 677 // Perform lookup into this declaration context. 678 DeclContext::lookup_result DR = DC->lookup(R.getLookupName()); 679 for (DeclContext::lookup_iterator I = DR.begin(), E = DR.end(); I != E; 680 ++I) { 681 NamedDecl *D = *I; 682 if ((D = R.getAcceptableDecl(D))) { 683 R.addDecl(D); 684 Found = true; 685 } 686 } 687 688 if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R)) 689 return true; 690 691 if (R.getLookupName().getNameKind() 692 != DeclarationName::CXXConversionFunctionName || 693 R.getLookupName().getCXXNameType()->isDependentType() || 694 !isa<CXXRecordDecl>(DC)) 695 return Found; 696 697 // C++ [temp.mem]p6: 698 // A specialization of a conversion function template is not found by 699 // name lookup. Instead, any conversion function templates visible in the 700 // context of the use are considered. [...] 701 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC); 702 if (!Record->isCompleteDefinition()) 703 return Found; 704 705 for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(), 706 UEnd = Record->conversion_end(); U != UEnd; ++U) { 707 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U); 708 if (!ConvTemplate) 709 continue; 710 711 // When we're performing lookup for the purposes of redeclaration, just 712 // add the conversion function template. When we deduce template 713 // arguments for specializations, we'll end up unifying the return 714 // type of the new declaration with the type of the function template. 715 if (R.isForRedeclaration()) { 716 R.addDecl(ConvTemplate); 717 Found = true; 718 continue; 719 } 720 721 // C++ [temp.mem]p6: 722 // [...] For each such operator, if argument deduction succeeds 723 // (14.9.2.3), the resulting specialization is used as if found by 724 // name lookup. 725 // 726 // When referencing a conversion function for any purpose other than 727 // a redeclaration (such that we'll be building an expression with the 728 // result), perform template argument deduction and place the 729 // specialization into the result set. We do this to avoid forcing all 730 // callers to perform special deduction for conversion functions. 731 TemplateDeductionInfo Info(R.getNameLoc()); 732 FunctionDecl *Specialization = nullptr; 733 734 const FunctionProtoType *ConvProto 735 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>(); 736 assert(ConvProto && "Nonsensical conversion function template type"); 737 738 // Compute the type of the function that we would expect the conversion 739 // function to have, if it were to match the name given. 740 // FIXME: Calling convention! 741 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo(); 742 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C); 743 EPI.ExceptionSpec = EST_None; 744 QualType ExpectedType 745 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(), 746 None, EPI); 747 748 // Perform template argument deduction against the type that we would 749 // expect the function to have. 750 if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType, 751 Specialization, Info) 752 == Sema::TDK_Success) { 753 R.addDecl(Specialization); 754 Found = true; 755 } 756 } 757 758 return Found; 759 } 760 761 // Performs C++ unqualified lookup into the given file context. 762 static bool 763 CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context, 764 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) { 765 766 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!"); 767 768 // Perform direct name lookup into the LookupCtx. 769 bool Found = LookupDirect(S, R, NS); 770 771 // Perform direct name lookup into the namespaces nominated by the 772 // using directives whose common ancestor is this namespace. 773 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS)) 774 if (LookupDirect(S, R, UUE.getNominatedNamespace())) 775 Found = true; 776 777 R.resolveKind(); 778 779 return Found; 780 } 781 782 static bool isNamespaceOrTranslationUnitScope(Scope *S) { 783 if (DeclContext *Ctx = S->getEntity()) 784 return Ctx->isFileContext(); 785 return false; 786 } 787 788 // Find the next outer declaration context from this scope. This 789 // routine actually returns the semantic outer context, which may 790 // differ from the lexical context (encoded directly in the Scope 791 // stack) when we are parsing a member of a class template. In this 792 // case, the second element of the pair will be true, to indicate that 793 // name lookup should continue searching in this semantic context when 794 // it leaves the current template parameter scope. 795 static std::pair<DeclContext *, bool> findOuterContext(Scope *S) { 796 DeclContext *DC = S->getEntity(); 797 DeclContext *Lexical = nullptr; 798 for (Scope *OuterS = S->getParent(); OuterS; 799 OuterS = OuterS->getParent()) { 800 if (OuterS->getEntity()) { 801 Lexical = OuterS->getEntity(); 802 break; 803 } 804 } 805 806 // C++ [temp.local]p8: 807 // In the definition of a member of a class template that appears 808 // outside of the namespace containing the class template 809 // definition, the name of a template-parameter hides the name of 810 // a member of this namespace. 811 // 812 // Example: 813 // 814 // namespace N { 815 // class C { }; 816 // 817 // template<class T> class B { 818 // void f(T); 819 // }; 820 // } 821 // 822 // template<class C> void N::B<C>::f(C) { 823 // C b; // C is the template parameter, not N::C 824 // } 825 // 826 // In this example, the lexical context we return is the 827 // TranslationUnit, while the semantic context is the namespace N. 828 if (!Lexical || !DC || !S->getParent() || 829 !S->getParent()->isTemplateParamScope()) 830 return std::make_pair(Lexical, false); 831 832 // Find the outermost template parameter scope. 833 // For the example, this is the scope for the template parameters of 834 // template<class C>. 835 Scope *OutermostTemplateScope = S->getParent(); 836 while (OutermostTemplateScope->getParent() && 837 OutermostTemplateScope->getParent()->isTemplateParamScope()) 838 OutermostTemplateScope = OutermostTemplateScope->getParent(); 839 840 // Find the namespace context in which the original scope occurs. In 841 // the example, this is namespace N. 842 DeclContext *Semantic = DC; 843 while (!Semantic->isFileContext()) 844 Semantic = Semantic->getParent(); 845 846 // Find the declaration context just outside of the template 847 // parameter scope. This is the context in which the template is 848 // being lexically declaration (a namespace context). In the 849 // example, this is the global scope. 850 if (Lexical->isFileContext() && !Lexical->Equals(Semantic) && 851 Lexical->Encloses(Semantic)) 852 return std::make_pair(Semantic, true); 853 854 return std::make_pair(Lexical, false); 855 } 856 857 namespace { 858 /// An RAII object to specify that we want to find block scope extern 859 /// declarations. 860 struct FindLocalExternScope { 861 FindLocalExternScope(LookupResult &R) 862 : R(R), OldFindLocalExtern(R.getIdentifierNamespace() & 863 Decl::IDNS_LocalExtern) { 864 R.setFindLocalExtern(R.getIdentifierNamespace() & Decl::IDNS_Ordinary); 865 } 866 void restore() { 867 R.setFindLocalExtern(OldFindLocalExtern); 868 } 869 ~FindLocalExternScope() { 870 restore(); 871 } 872 LookupResult &R; 873 bool OldFindLocalExtern; 874 }; 875 } 876 877 bool Sema::CppLookupName(LookupResult &R, Scope *S) { 878 assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup"); 879 880 DeclarationName Name = R.getLookupName(); 881 Sema::LookupNameKind NameKind = R.getLookupKind(); 882 883 // If this is the name of an implicitly-declared special member function, 884 // go through the scope stack to implicitly declare 885 if (isImplicitlyDeclaredMemberFunctionName(Name)) { 886 for (Scope *PreS = S; PreS; PreS = PreS->getParent()) 887 if (DeclContext *DC = PreS->getEntity()) 888 DeclareImplicitMemberFunctionsWithName(*this, Name, DC); 889 } 890 891 // Implicitly declare member functions with the name we're looking for, if in 892 // fact we are in a scope where it matters. 893 894 Scope *Initial = S; 895 IdentifierResolver::iterator 896 I = IdResolver.begin(Name), 897 IEnd = IdResolver.end(); 898 899 // First we lookup local scope. 900 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir] 901 // ...During unqualified name lookup (3.4.1), the names appear as if 902 // they were declared in the nearest enclosing namespace which contains 903 // both the using-directive and the nominated namespace. 904 // [Note: in this context, "contains" means "contains directly or 905 // indirectly". 906 // 907 // For example: 908 // namespace A { int i; } 909 // void foo() { 910 // int i; 911 // { 912 // using namespace A; 913 // ++i; // finds local 'i', A::i appears at global scope 914 // } 915 // } 916 // 917 UnqualUsingDirectiveSet UDirs; 918 bool VisitedUsingDirectives = false; 919 bool LeftStartingScope = false; 920 DeclContext *OutsideOfTemplateParamDC = nullptr; 921 922 // When performing a scope lookup, we want to find local extern decls. 923 FindLocalExternScope FindLocals(R); 924 925 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) { 926 DeclContext *Ctx = S->getEntity(); 927 928 // Check whether the IdResolver has anything in this scope. 929 bool Found = false; 930 for (; I != IEnd && S->isDeclScope(*I); ++I) { 931 if (NamedDecl *ND = R.getAcceptableDecl(*I)) { 932 if (NameKind == LookupRedeclarationWithLinkage) { 933 // Determine whether this (or a previous) declaration is 934 // out-of-scope. 935 if (!LeftStartingScope && !Initial->isDeclScope(*I)) 936 LeftStartingScope = true; 937 938 // If we found something outside of our starting scope that 939 // does not have linkage, skip it. If it's a template parameter, 940 // we still find it, so we can diagnose the invalid redeclaration. 941 if (LeftStartingScope && !((*I)->hasLinkage()) && 942 !(*I)->isTemplateParameter()) { 943 R.setShadowed(); 944 continue; 945 } 946 } 947 948 Found = true; 949 R.addDecl(ND); 950 } 951 } 952 if (Found) { 953 R.resolveKind(); 954 if (S->isClassScope()) 955 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx)) 956 R.setNamingClass(Record); 957 return true; 958 } 959 960 if (NameKind == LookupLocalFriendName && !S->isClassScope()) { 961 // C++11 [class.friend]p11: 962 // If a friend declaration appears in a local class and the name 963 // specified is an unqualified name, a prior declaration is 964 // looked up without considering scopes that are outside the 965 // innermost enclosing non-class scope. 966 return false; 967 } 968 969 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC && 970 S->getParent() && !S->getParent()->isTemplateParamScope()) { 971 // We've just searched the last template parameter scope and 972 // found nothing, so look into the contexts between the 973 // lexical and semantic declaration contexts returned by 974 // findOuterContext(). This implements the name lookup behavior 975 // of C++ [temp.local]p8. 976 Ctx = OutsideOfTemplateParamDC; 977 OutsideOfTemplateParamDC = nullptr; 978 } 979 980 if (Ctx) { 981 DeclContext *OuterCtx; 982 bool SearchAfterTemplateScope; 983 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S); 984 if (SearchAfterTemplateScope) 985 OutsideOfTemplateParamDC = OuterCtx; 986 987 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 988 // We do not directly look into transparent contexts, since 989 // those entities will be found in the nearest enclosing 990 // non-transparent context. 991 if (Ctx->isTransparentContext()) 992 continue; 993 994 // We do not look directly into function or method contexts, 995 // since all of the local variables and parameters of the 996 // function/method are present within the Scope. 997 if (Ctx->isFunctionOrMethod()) { 998 // If we have an Objective-C instance method, look for ivars 999 // in the corresponding interface. 1000 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 1001 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo()) 1002 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) { 1003 ObjCInterfaceDecl *ClassDeclared; 1004 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable( 1005 Name.getAsIdentifierInfo(), 1006 ClassDeclared)) { 1007 if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) { 1008 R.addDecl(ND); 1009 R.resolveKind(); 1010 return true; 1011 } 1012 } 1013 } 1014 } 1015 1016 continue; 1017 } 1018 1019 // If this is a file context, we need to perform unqualified name 1020 // lookup considering using directives. 1021 if (Ctx->isFileContext()) { 1022 // If we haven't handled using directives yet, do so now. 1023 if (!VisitedUsingDirectives) { 1024 // Add using directives from this context up to the top level. 1025 for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) { 1026 if (UCtx->isTransparentContext()) 1027 continue; 1028 1029 UDirs.visit(UCtx, UCtx); 1030 } 1031 1032 // Find the innermost file scope, so we can add using directives 1033 // from local scopes. 1034 Scope *InnermostFileScope = S; 1035 while (InnermostFileScope && 1036 !isNamespaceOrTranslationUnitScope(InnermostFileScope)) 1037 InnermostFileScope = InnermostFileScope->getParent(); 1038 UDirs.visitScopeChain(Initial, InnermostFileScope); 1039 1040 UDirs.done(); 1041 1042 VisitedUsingDirectives = true; 1043 } 1044 1045 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) { 1046 R.resolveKind(); 1047 return true; 1048 } 1049 1050 continue; 1051 } 1052 1053 // Perform qualified name lookup into this context. 1054 // FIXME: In some cases, we know that every name that could be found by 1055 // this qualified name lookup will also be on the identifier chain. For 1056 // example, inside a class without any base classes, we never need to 1057 // perform qualified lookup because all of the members are on top of the 1058 // identifier chain. 1059 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true)) 1060 return true; 1061 } 1062 } 1063 } 1064 1065 // Stop if we ran out of scopes. 1066 // FIXME: This really, really shouldn't be happening. 1067 if (!S) return false; 1068 1069 // If we are looking for members, no need to look into global/namespace scope. 1070 if (NameKind == LookupMemberName) 1071 return false; 1072 1073 // Collect UsingDirectiveDecls in all scopes, and recursively all 1074 // nominated namespaces by those using-directives. 1075 // 1076 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we 1077 // don't build it for each lookup! 1078 if (!VisitedUsingDirectives) { 1079 UDirs.visitScopeChain(Initial, S); 1080 UDirs.done(); 1081 } 1082 1083 // If we're not performing redeclaration lookup, do not look for local 1084 // extern declarations outside of a function scope. 1085 if (!R.isForRedeclaration()) 1086 FindLocals.restore(); 1087 1088 // Lookup namespace scope, and global scope. 1089 // Unqualified name lookup in C++ requires looking into scopes 1090 // that aren't strictly lexical, and therefore we walk through the 1091 // context as well as walking through the scopes. 1092 for (; S; S = S->getParent()) { 1093 // Check whether the IdResolver has anything in this scope. 1094 bool Found = false; 1095 for (; I != IEnd && S->isDeclScope(*I); ++I) { 1096 if (NamedDecl *ND = R.getAcceptableDecl(*I)) { 1097 // We found something. Look for anything else in our scope 1098 // with this same name and in an acceptable identifier 1099 // namespace, so that we can construct an overload set if we 1100 // need to. 1101 Found = true; 1102 R.addDecl(ND); 1103 } 1104 } 1105 1106 if (Found && S->isTemplateParamScope()) { 1107 R.resolveKind(); 1108 return true; 1109 } 1110 1111 DeclContext *Ctx = S->getEntity(); 1112 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC && 1113 S->getParent() && !S->getParent()->isTemplateParamScope()) { 1114 // We've just searched the last template parameter scope and 1115 // found nothing, so look into the contexts between the 1116 // lexical and semantic declaration contexts returned by 1117 // findOuterContext(). This implements the name lookup behavior 1118 // of C++ [temp.local]p8. 1119 Ctx = OutsideOfTemplateParamDC; 1120 OutsideOfTemplateParamDC = nullptr; 1121 } 1122 1123 if (Ctx) { 1124 DeclContext *OuterCtx; 1125 bool SearchAfterTemplateScope; 1126 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S); 1127 if (SearchAfterTemplateScope) 1128 OutsideOfTemplateParamDC = OuterCtx; 1129 1130 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 1131 // We do not directly look into transparent contexts, since 1132 // those entities will be found in the nearest enclosing 1133 // non-transparent context. 1134 if (Ctx->isTransparentContext()) 1135 continue; 1136 1137 // If we have a context, and it's not a context stashed in the 1138 // template parameter scope for an out-of-line definition, also 1139 // look into that context. 1140 if (!(Found && S && S->isTemplateParamScope())) { 1141 assert(Ctx->isFileContext() && 1142 "We should have been looking only at file context here already."); 1143 1144 // Look into context considering using-directives. 1145 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) 1146 Found = true; 1147 } 1148 1149 if (Found) { 1150 R.resolveKind(); 1151 return true; 1152 } 1153 1154 if (R.isForRedeclaration() && !Ctx->isTransparentContext()) 1155 return false; 1156 } 1157 } 1158 1159 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext()) 1160 return false; 1161 } 1162 1163 return !R.empty(); 1164 } 1165 1166 /// \brief Find the declaration that a class temploid member specialization was 1167 /// instantiated from, or the member itself if it is an explicit specialization. 1168 static Decl *getInstantiatedFrom(Decl *D, MemberSpecializationInfo *MSInfo) { 1169 return MSInfo->isExplicitSpecialization() ? D : MSInfo->getInstantiatedFrom(); 1170 } 1171 1172 /// \brief Find the module in which the given declaration was defined. 1173 static Module *getDefiningModule(Decl *Entity) { 1174 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) { 1175 // If this function was instantiated from a template, the defining module is 1176 // the module containing the pattern. 1177 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern()) 1178 Entity = Pattern; 1179 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) { 1180 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern()) 1181 Entity = Pattern; 1182 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) { 1183 if (MemberSpecializationInfo *MSInfo = ED->getMemberSpecializationInfo()) 1184 Entity = getInstantiatedFrom(ED, MSInfo); 1185 } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) { 1186 // FIXME: Map from variable template specializations back to the template. 1187 if (MemberSpecializationInfo *MSInfo = VD->getMemberSpecializationInfo()) 1188 Entity = getInstantiatedFrom(VD, MSInfo); 1189 } 1190 1191 // Walk up to the containing context. That might also have been instantiated 1192 // from a template. 1193 DeclContext *Context = Entity->getDeclContext(); 1194 if (Context->isFileContext()) 1195 return Entity->getOwningModule(); 1196 return getDefiningModule(cast<Decl>(Context)); 1197 } 1198 1199 llvm::DenseSet<Module*> &Sema::getLookupModules() { 1200 unsigned N = ActiveTemplateInstantiations.size(); 1201 for (unsigned I = ActiveTemplateInstantiationLookupModules.size(); 1202 I != N; ++I) { 1203 Module *M = getDefiningModule(ActiveTemplateInstantiations[I].Entity); 1204 if (M && !LookupModulesCache.insert(M).second) 1205 M = nullptr; 1206 ActiveTemplateInstantiationLookupModules.push_back(M); 1207 } 1208 return LookupModulesCache; 1209 } 1210 1211 /// \brief Determine whether a declaration is visible to name lookup. 1212 /// 1213 /// This routine determines whether the declaration D is visible in the current 1214 /// lookup context, taking into account the current template instantiation 1215 /// stack. During template instantiation, a declaration is visible if it is 1216 /// visible from a module containing any entity on the template instantiation 1217 /// path (by instantiating a template, you allow it to see the declarations that 1218 /// your module can see, including those later on in your module). 1219 bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) { 1220 assert(D->isHidden() && "should not call this: not in slow case"); 1221 Module *DeclModule = D->getOwningModule(); 1222 assert(DeclModule && "hidden decl not from a module"); 1223 1224 // If this declaration is not at namespace scope nor module-private, 1225 // then it is visible if its lexical parent has a visible definition. 1226 DeclContext *DC = D->getLexicalDeclContext(); 1227 if (!D->isModulePrivate() && 1228 DC && !DC->isFileContext() && !isa<LinkageSpecDecl>(DC)) { 1229 if (SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC))) { 1230 if (SemaRef.ActiveTemplateInstantiations.empty()) { 1231 // Cache the fact that this declaration is implicitly visible because 1232 // its parent has a visible definition. 1233 D->setHidden(false); 1234 } 1235 return true; 1236 } 1237 return false; 1238 } 1239 1240 // Find the extra places where we need to look. 1241 llvm::DenseSet<Module*> &LookupModules = SemaRef.getLookupModules(); 1242 if (LookupModules.empty()) 1243 return false; 1244 1245 // If our lookup set contains the decl's module, it's visible. 1246 if (LookupModules.count(DeclModule)) 1247 return true; 1248 1249 // If the declaration isn't exported, it's not visible in any other module. 1250 if (D->isModulePrivate()) 1251 return false; 1252 1253 // Check whether DeclModule is transitively exported to an import of 1254 // the lookup set. 1255 for (llvm::DenseSet<Module *>::iterator I = LookupModules.begin(), 1256 E = LookupModules.end(); 1257 I != E; ++I) 1258 if ((*I)->isModuleVisible(DeclModule)) 1259 return true; 1260 return false; 1261 } 1262 1263 /// \brief Retrieve the visible declaration corresponding to D, if any. 1264 /// 1265 /// This routine determines whether the declaration D is visible in the current 1266 /// module, with the current imports. If not, it checks whether any 1267 /// redeclaration of D is visible, and if so, returns that declaration. 1268 /// 1269 /// \returns D, or a visible previous declaration of D, whichever is more recent 1270 /// and visible. If no declaration of D is visible, returns null. 1271 static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D) { 1272 assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case"); 1273 1274 for (auto RD : D->redecls()) { 1275 if (auto ND = dyn_cast<NamedDecl>(RD)) { 1276 // FIXME: This is wrong in the case where the previous declaration is not 1277 // visible in the same scope as D. This needs to be done much more 1278 // carefully. 1279 if (LookupResult::isVisible(SemaRef, ND)) 1280 return ND; 1281 } 1282 } 1283 1284 return nullptr; 1285 } 1286 1287 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const { 1288 return findAcceptableDecl(getSema(), D); 1289 } 1290 1291 /// @brief Perform unqualified name lookup starting from a given 1292 /// scope. 1293 /// 1294 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is 1295 /// used to find names within the current scope. For example, 'x' in 1296 /// @code 1297 /// int x; 1298 /// int f() { 1299 /// return x; // unqualified name look finds 'x' in the global scope 1300 /// } 1301 /// @endcode 1302 /// 1303 /// Different lookup criteria can find different names. For example, a 1304 /// particular scope can have both a struct and a function of the same 1305 /// name, and each can be found by certain lookup criteria. For more 1306 /// information about lookup criteria, see the documentation for the 1307 /// class LookupCriteria. 1308 /// 1309 /// @param S The scope from which unqualified name lookup will 1310 /// begin. If the lookup criteria permits, name lookup may also search 1311 /// in the parent scopes. 1312 /// 1313 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to 1314 /// look up and the lookup kind), and is updated with the results of lookup 1315 /// including zero or more declarations and possibly additional information 1316 /// used to diagnose ambiguities. 1317 /// 1318 /// @returns \c true if lookup succeeded and false otherwise. 1319 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) { 1320 DeclarationName Name = R.getLookupName(); 1321 if (!Name) return false; 1322 1323 LookupNameKind NameKind = R.getLookupKind(); 1324 1325 if (!getLangOpts().CPlusPlus) { 1326 // Unqualified name lookup in C/Objective-C is purely lexical, so 1327 // search in the declarations attached to the name. 1328 if (NameKind == Sema::LookupRedeclarationWithLinkage) { 1329 // Find the nearest non-transparent declaration scope. 1330 while (!(S->getFlags() & Scope::DeclScope) || 1331 (S->getEntity() && S->getEntity()->isTransparentContext())) 1332 S = S->getParent(); 1333 } 1334 1335 // When performing a scope lookup, we want to find local extern decls. 1336 FindLocalExternScope FindLocals(R); 1337 1338 // Scan up the scope chain looking for a decl that matches this 1339 // identifier that is in the appropriate namespace. This search 1340 // should not take long, as shadowing of names is uncommon, and 1341 // deep shadowing is extremely uncommon. 1342 bool LeftStartingScope = false; 1343 1344 for (IdentifierResolver::iterator I = IdResolver.begin(Name), 1345 IEnd = IdResolver.end(); 1346 I != IEnd; ++I) 1347 if (NamedDecl *D = R.getAcceptableDecl(*I)) { 1348 if (NameKind == LookupRedeclarationWithLinkage) { 1349 // Determine whether this (or a previous) declaration is 1350 // out-of-scope. 1351 if (!LeftStartingScope && !S->isDeclScope(*I)) 1352 LeftStartingScope = true; 1353 1354 // If we found something outside of our starting scope that 1355 // does not have linkage, skip it. 1356 if (LeftStartingScope && !((*I)->hasLinkage())) { 1357 R.setShadowed(); 1358 continue; 1359 } 1360 } 1361 else if (NameKind == LookupObjCImplicitSelfParam && 1362 !isa<ImplicitParamDecl>(*I)) 1363 continue; 1364 1365 R.addDecl(D); 1366 1367 // Check whether there are any other declarations with the same name 1368 // and in the same scope. 1369 if (I != IEnd) { 1370 // Find the scope in which this declaration was declared (if it 1371 // actually exists in a Scope). 1372 while (S && !S->isDeclScope(D)) 1373 S = S->getParent(); 1374 1375 // If the scope containing the declaration is the translation unit, 1376 // then we'll need to perform our checks based on the matching 1377 // DeclContexts rather than matching scopes. 1378 if (S && isNamespaceOrTranslationUnitScope(S)) 1379 S = nullptr; 1380 1381 // Compute the DeclContext, if we need it. 1382 DeclContext *DC = nullptr; 1383 if (!S) 1384 DC = (*I)->getDeclContext()->getRedeclContext(); 1385 1386 IdentifierResolver::iterator LastI = I; 1387 for (++LastI; LastI != IEnd; ++LastI) { 1388 if (S) { 1389 // Match based on scope. 1390 if (!S->isDeclScope(*LastI)) 1391 break; 1392 } else { 1393 // Match based on DeclContext. 1394 DeclContext *LastDC 1395 = (*LastI)->getDeclContext()->getRedeclContext(); 1396 if (!LastDC->Equals(DC)) 1397 break; 1398 } 1399 1400 // If the declaration is in the right namespace and visible, add it. 1401 if (NamedDecl *LastD = R.getAcceptableDecl(*LastI)) 1402 R.addDecl(LastD); 1403 } 1404 1405 R.resolveKind(); 1406 } 1407 1408 return true; 1409 } 1410 } else { 1411 // Perform C++ unqualified name lookup. 1412 if (CppLookupName(R, S)) 1413 return true; 1414 } 1415 1416 // If we didn't find a use of this identifier, and if the identifier 1417 // corresponds to a compiler builtin, create the decl object for the builtin 1418 // now, injecting it into translation unit scope, and return it. 1419 if (AllowBuiltinCreation && LookupBuiltin(*this, R)) 1420 return true; 1421 1422 // If we didn't find a use of this identifier, the ExternalSource 1423 // may be able to handle the situation. 1424 // Note: some lookup failures are expected! 1425 // See e.g. R.isForRedeclaration(). 1426 return (ExternalSource && ExternalSource->LookupUnqualified(R, S)); 1427 } 1428 1429 /// @brief Perform qualified name lookup in the namespaces nominated by 1430 /// using directives by the given context. 1431 /// 1432 /// C++98 [namespace.qual]p2: 1433 /// Given X::m (where X is a user-declared namespace), or given \::m 1434 /// (where X is the global namespace), let S be the set of all 1435 /// declarations of m in X and in the transitive closure of all 1436 /// namespaces nominated by using-directives in X and its used 1437 /// namespaces, except that using-directives are ignored in any 1438 /// namespace, including X, directly containing one or more 1439 /// declarations of m. No namespace is searched more than once in 1440 /// the lookup of a name. If S is the empty set, the program is 1441 /// ill-formed. Otherwise, if S has exactly one member, or if the 1442 /// context of the reference is a using-declaration 1443 /// (namespace.udecl), S is the required set of declarations of 1444 /// m. Otherwise if the use of m is not one that allows a unique 1445 /// declaration to be chosen from S, the program is ill-formed. 1446 /// 1447 /// C++98 [namespace.qual]p5: 1448 /// During the lookup of a qualified namespace member name, if the 1449 /// lookup finds more than one declaration of the member, and if one 1450 /// declaration introduces a class name or enumeration name and the 1451 /// other declarations either introduce the same object, the same 1452 /// enumerator or a set of functions, the non-type name hides the 1453 /// class or enumeration name if and only if the declarations are 1454 /// from the same namespace; otherwise (the declarations are from 1455 /// different namespaces), the program is ill-formed. 1456 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R, 1457 DeclContext *StartDC) { 1458 assert(StartDC->isFileContext() && "start context is not a file context"); 1459 1460 DeclContext::udir_range UsingDirectives = StartDC->using_directives(); 1461 if (UsingDirectives.begin() == UsingDirectives.end()) return false; 1462 1463 // We have at least added all these contexts to the queue. 1464 llvm::SmallPtrSet<DeclContext*, 8> Visited; 1465 Visited.insert(StartDC); 1466 1467 // We have not yet looked into these namespaces, much less added 1468 // their "using-children" to the queue. 1469 SmallVector<NamespaceDecl*, 8> Queue; 1470 1471 // We have already looked into the initial namespace; seed the queue 1472 // with its using-children. 1473 for (auto *I : UsingDirectives) { 1474 NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace(); 1475 if (Visited.insert(ND).second) 1476 Queue.push_back(ND); 1477 } 1478 1479 // The easiest way to implement the restriction in [namespace.qual]p5 1480 // is to check whether any of the individual results found a tag 1481 // and, if so, to declare an ambiguity if the final result is not 1482 // a tag. 1483 bool FoundTag = false; 1484 bool FoundNonTag = false; 1485 1486 LookupResult LocalR(LookupResult::Temporary, R); 1487 1488 bool Found = false; 1489 while (!Queue.empty()) { 1490 NamespaceDecl *ND = Queue.pop_back_val(); 1491 1492 // We go through some convolutions here to avoid copying results 1493 // between LookupResults. 1494 bool UseLocal = !R.empty(); 1495 LookupResult &DirectR = UseLocal ? LocalR : R; 1496 bool FoundDirect = LookupDirect(S, DirectR, ND); 1497 1498 if (FoundDirect) { 1499 // First do any local hiding. 1500 DirectR.resolveKind(); 1501 1502 // If the local result is a tag, remember that. 1503 if (DirectR.isSingleTagDecl()) 1504 FoundTag = true; 1505 else 1506 FoundNonTag = true; 1507 1508 // Append the local results to the total results if necessary. 1509 if (UseLocal) { 1510 R.addAllDecls(LocalR); 1511 LocalR.clear(); 1512 } 1513 } 1514 1515 // If we find names in this namespace, ignore its using directives. 1516 if (FoundDirect) { 1517 Found = true; 1518 continue; 1519 } 1520 1521 for (auto I : ND->using_directives()) { 1522 NamespaceDecl *Nom = I->getNominatedNamespace(); 1523 if (Visited.insert(Nom).second) 1524 Queue.push_back(Nom); 1525 } 1526 } 1527 1528 if (Found) { 1529 if (FoundTag && FoundNonTag) 1530 R.setAmbiguousQualifiedTagHiding(); 1531 else 1532 R.resolveKind(); 1533 } 1534 1535 return Found; 1536 } 1537 1538 /// \brief Callback that looks for any member of a class with the given name. 1539 static bool LookupAnyMember(const CXXBaseSpecifier *Specifier, 1540 CXXBasePath &Path, 1541 void *Name) { 1542 RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl(); 1543 1544 DeclarationName N = DeclarationName::getFromOpaquePtr(Name); 1545 Path.Decls = BaseRecord->lookup(N); 1546 return !Path.Decls.empty(); 1547 } 1548 1549 /// \brief Determine whether the given set of member declarations contains only 1550 /// static members, nested types, and enumerators. 1551 template<typename InputIterator> 1552 static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) { 1553 Decl *D = (*First)->getUnderlyingDecl(); 1554 if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D)) 1555 return true; 1556 1557 if (isa<CXXMethodDecl>(D)) { 1558 // Determine whether all of the methods are static. 1559 bool AllMethodsAreStatic = true; 1560 for(; First != Last; ++First) { 1561 D = (*First)->getUnderlyingDecl(); 1562 1563 if (!isa<CXXMethodDecl>(D)) { 1564 assert(isa<TagDecl>(D) && "Non-function must be a tag decl"); 1565 break; 1566 } 1567 1568 if (!cast<CXXMethodDecl>(D)->isStatic()) { 1569 AllMethodsAreStatic = false; 1570 break; 1571 } 1572 } 1573 1574 if (AllMethodsAreStatic) 1575 return true; 1576 } 1577 1578 return false; 1579 } 1580 1581 /// \brief Perform qualified name lookup into a given context. 1582 /// 1583 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find 1584 /// names when the context of those names is explicit specified, e.g., 1585 /// "std::vector" or "x->member", or as part of unqualified name lookup. 1586 /// 1587 /// Different lookup criteria can find different names. For example, a 1588 /// particular scope can have both a struct and a function of the same 1589 /// name, and each can be found by certain lookup criteria. For more 1590 /// information about lookup criteria, see the documentation for the 1591 /// class LookupCriteria. 1592 /// 1593 /// \param R captures both the lookup criteria and any lookup results found. 1594 /// 1595 /// \param LookupCtx The context in which qualified name lookup will 1596 /// search. If the lookup criteria permits, name lookup may also search 1597 /// in the parent contexts or (for C++ classes) base classes. 1598 /// 1599 /// \param InUnqualifiedLookup true if this is qualified name lookup that 1600 /// occurs as part of unqualified name lookup. 1601 /// 1602 /// \returns true if lookup succeeded, false if it failed. 1603 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 1604 bool InUnqualifiedLookup) { 1605 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context"); 1606 1607 if (!R.getLookupName()) 1608 return false; 1609 1610 // Make sure that the declaration context is complete. 1611 assert((!isa<TagDecl>(LookupCtx) || 1612 LookupCtx->isDependentContext() || 1613 cast<TagDecl>(LookupCtx)->isCompleteDefinition() || 1614 cast<TagDecl>(LookupCtx)->isBeingDefined()) && 1615 "Declaration context must already be complete!"); 1616 1617 // Perform qualified name lookup into the LookupCtx. 1618 if (LookupDirect(*this, R, LookupCtx)) { 1619 R.resolveKind(); 1620 if (isa<CXXRecordDecl>(LookupCtx)) 1621 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx)); 1622 return true; 1623 } 1624 1625 // Don't descend into implied contexts for redeclarations. 1626 // C++98 [namespace.qual]p6: 1627 // In a declaration for a namespace member in which the 1628 // declarator-id is a qualified-id, given that the qualified-id 1629 // for the namespace member has the form 1630 // nested-name-specifier unqualified-id 1631 // the unqualified-id shall name a member of the namespace 1632 // designated by the nested-name-specifier. 1633 // See also [class.mfct]p5 and [class.static.data]p2. 1634 if (R.isForRedeclaration()) 1635 return false; 1636 1637 // If this is a namespace, look it up in the implied namespaces. 1638 if (LookupCtx->isFileContext()) 1639 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx); 1640 1641 // If this isn't a C++ class, we aren't allowed to look into base 1642 // classes, we're done. 1643 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx); 1644 if (!LookupRec || !LookupRec->getDefinition()) 1645 return false; 1646 1647 // If we're performing qualified name lookup into a dependent class, 1648 // then we are actually looking into a current instantiation. If we have any 1649 // dependent base classes, then we either have to delay lookup until 1650 // template instantiation time (at which point all bases will be available) 1651 // or we have to fail. 1652 if (!InUnqualifiedLookup && LookupRec->isDependentContext() && 1653 LookupRec->hasAnyDependentBases()) { 1654 R.setNotFoundInCurrentInstantiation(); 1655 return false; 1656 } 1657 1658 // Perform lookup into our base classes. 1659 CXXBasePaths Paths; 1660 Paths.setOrigin(LookupRec); 1661 1662 // Look for this member in our base classes 1663 CXXRecordDecl::BaseMatchesCallback *BaseCallback = nullptr; 1664 switch (R.getLookupKind()) { 1665 case LookupObjCImplicitSelfParam: 1666 case LookupOrdinaryName: 1667 case LookupMemberName: 1668 case LookupRedeclarationWithLinkage: 1669 case LookupLocalFriendName: 1670 BaseCallback = &CXXRecordDecl::FindOrdinaryMember; 1671 break; 1672 1673 case LookupTagName: 1674 BaseCallback = &CXXRecordDecl::FindTagMember; 1675 break; 1676 1677 case LookupAnyName: 1678 BaseCallback = &LookupAnyMember; 1679 break; 1680 1681 case LookupUsingDeclName: 1682 // This lookup is for redeclarations only. 1683 1684 case LookupOperatorName: 1685 case LookupNamespaceName: 1686 case LookupObjCProtocolName: 1687 case LookupLabel: 1688 // These lookups will never find a member in a C++ class (or base class). 1689 return false; 1690 1691 case LookupNestedNameSpecifierName: 1692 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember; 1693 break; 1694 } 1695 1696 if (!LookupRec->lookupInBases(BaseCallback, 1697 R.getLookupName().getAsOpaquePtr(), Paths)) 1698 return false; 1699 1700 R.setNamingClass(LookupRec); 1701 1702 // C++ [class.member.lookup]p2: 1703 // [...] If the resulting set of declarations are not all from 1704 // sub-objects of the same type, or the set has a nonstatic member 1705 // and includes members from distinct sub-objects, there is an 1706 // ambiguity and the program is ill-formed. Otherwise that set is 1707 // the result of the lookup. 1708 QualType SubobjectType; 1709 int SubobjectNumber = 0; 1710 AccessSpecifier SubobjectAccess = AS_none; 1711 1712 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); 1713 Path != PathEnd; ++Path) { 1714 const CXXBasePathElement &PathElement = Path->back(); 1715 1716 // Pick the best (i.e. most permissive i.e. numerically lowest) access 1717 // across all paths. 1718 SubobjectAccess = std::min(SubobjectAccess, Path->Access); 1719 1720 // Determine whether we're looking at a distinct sub-object or not. 1721 if (SubobjectType.isNull()) { 1722 // This is the first subobject we've looked at. Record its type. 1723 SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); 1724 SubobjectNumber = PathElement.SubobjectNumber; 1725 continue; 1726 } 1727 1728 if (SubobjectType 1729 != Context.getCanonicalType(PathElement.Base->getType())) { 1730 // We found members of the given name in two subobjects of 1731 // different types. If the declaration sets aren't the same, this 1732 // lookup is ambiguous. 1733 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) { 1734 CXXBasePaths::paths_iterator FirstPath = Paths.begin(); 1735 DeclContext::lookup_iterator FirstD = FirstPath->Decls.begin(); 1736 DeclContext::lookup_iterator CurrentD = Path->Decls.begin(); 1737 1738 while (FirstD != FirstPath->Decls.end() && 1739 CurrentD != Path->Decls.end()) { 1740 if ((*FirstD)->getUnderlyingDecl()->getCanonicalDecl() != 1741 (*CurrentD)->getUnderlyingDecl()->getCanonicalDecl()) 1742 break; 1743 1744 ++FirstD; 1745 ++CurrentD; 1746 } 1747 1748 if (FirstD == FirstPath->Decls.end() && 1749 CurrentD == Path->Decls.end()) 1750 continue; 1751 } 1752 1753 R.setAmbiguousBaseSubobjectTypes(Paths); 1754 return true; 1755 } 1756 1757 if (SubobjectNumber != PathElement.SubobjectNumber) { 1758 // We have a different subobject of the same type. 1759 1760 // C++ [class.member.lookup]p5: 1761 // A static member, a nested type or an enumerator defined in 1762 // a base class T can unambiguously be found even if an object 1763 // has more than one base class subobject of type T. 1764 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) 1765 continue; 1766 1767 // We have found a nonstatic member name in multiple, distinct 1768 // subobjects. Name lookup is ambiguous. 1769 R.setAmbiguousBaseSubobjects(Paths); 1770 return true; 1771 } 1772 } 1773 1774 // Lookup in a base class succeeded; return these results. 1775 1776 for (auto *D : Paths.front().Decls) { 1777 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess, 1778 D->getAccess()); 1779 R.addDecl(D, AS); 1780 } 1781 R.resolveKind(); 1782 return true; 1783 } 1784 1785 /// \brief Performs qualified name lookup or special type of lookup for 1786 /// "__super::" scope specifier. 1787 /// 1788 /// This routine is a convenience overload meant to be called from contexts 1789 /// that need to perform a qualified name lookup with an optional C++ scope 1790 /// specifier that might require special kind of lookup. 1791 /// 1792 /// \param R captures both the lookup criteria and any lookup results found. 1793 /// 1794 /// \param LookupCtx The context in which qualified name lookup will 1795 /// search. 1796 /// 1797 /// \param SS An optional C++ scope-specifier. 1798 /// 1799 /// \returns true if lookup succeeded, false if it failed. 1800 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 1801 CXXScopeSpec &SS) { 1802 auto *NNS = SS.getScopeRep(); 1803 if (NNS && NNS->getKind() == NestedNameSpecifier::Super) 1804 return LookupInSuper(R, NNS->getAsRecordDecl()); 1805 else 1806 1807 return LookupQualifiedName(R, LookupCtx); 1808 } 1809 1810 /// @brief Performs name lookup for a name that was parsed in the 1811 /// source code, and may contain a C++ scope specifier. 1812 /// 1813 /// This routine is a convenience routine meant to be called from 1814 /// contexts that receive a name and an optional C++ scope specifier 1815 /// (e.g., "N::M::x"). It will then perform either qualified or 1816 /// unqualified name lookup (with LookupQualifiedName or LookupName, 1817 /// respectively) on the given name and return those results. It will 1818 /// perform a special type of lookup for "__super::" scope specifier. 1819 /// 1820 /// @param S The scope from which unqualified name lookup will 1821 /// begin. 1822 /// 1823 /// @param SS An optional C++ scope-specifier, e.g., "::N::M". 1824 /// 1825 /// @param EnteringContext Indicates whether we are going to enter the 1826 /// context of the scope-specifier SS (if present). 1827 /// 1828 /// @returns True if any decls were found (but possibly ambiguous) 1829 bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS, 1830 bool AllowBuiltinCreation, bool EnteringContext) { 1831 if (SS && SS->isInvalid()) { 1832 // When the scope specifier is invalid, don't even look for 1833 // anything. 1834 return false; 1835 } 1836 1837 if (SS && SS->isSet()) { 1838 NestedNameSpecifier *NNS = SS->getScopeRep(); 1839 if (NNS->getKind() == NestedNameSpecifier::Super) 1840 return LookupInSuper(R, NNS->getAsRecordDecl()); 1841 1842 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { 1843 // We have resolved the scope specifier to a particular declaration 1844 // contex, and will perform name lookup in that context. 1845 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC)) 1846 return false; 1847 1848 R.setContextRange(SS->getRange()); 1849 return LookupQualifiedName(R, DC); 1850 } 1851 1852 // We could not resolve the scope specified to a specific declaration 1853 // context, which means that SS refers to an unknown specialization. 1854 // Name lookup can't find anything in this case. 1855 R.setNotFoundInCurrentInstantiation(); 1856 R.setContextRange(SS->getRange()); 1857 return false; 1858 } 1859 1860 // Perform unqualified name lookup starting in the given scope. 1861 return LookupName(R, S, AllowBuiltinCreation); 1862 } 1863 1864 /// \brief Perform qualified name lookup into all base classes of the given 1865 /// class. 1866 /// 1867 /// \param R captures both the lookup criteria and any lookup results found. 1868 /// 1869 /// \param Class The context in which qualified name lookup will 1870 /// search. Name lookup will search in all base classes merging the results. 1871 /// 1872 /// @returns True if any decls were found (but possibly ambiguous) 1873 bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) { 1874 for (const auto &BaseSpec : Class->bases()) { 1875 CXXRecordDecl *RD = cast<CXXRecordDecl>( 1876 BaseSpec.getType()->castAs<RecordType>()->getDecl()); 1877 LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind()); 1878 Result.setBaseObjectType(Context.getRecordType(Class)); 1879 LookupQualifiedName(Result, RD); 1880 for (auto *Decl : Result) 1881 R.addDecl(Decl); 1882 } 1883 1884 R.resolveKind(); 1885 1886 return !R.empty(); 1887 } 1888 1889 /// \brief Produce a diagnostic describing the ambiguity that resulted 1890 /// from name lookup. 1891 /// 1892 /// \param Result The result of the ambiguous lookup to be diagnosed. 1893 void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) { 1894 assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); 1895 1896 DeclarationName Name = Result.getLookupName(); 1897 SourceLocation NameLoc = Result.getNameLoc(); 1898 SourceRange LookupRange = Result.getContextRange(); 1899 1900 switch (Result.getAmbiguityKind()) { 1901 case LookupResult::AmbiguousBaseSubobjects: { 1902 CXXBasePaths *Paths = Result.getBasePaths(); 1903 QualType SubobjectType = Paths->front().back().Base->getType(); 1904 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) 1905 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) 1906 << LookupRange; 1907 1908 DeclContext::lookup_iterator Found = Paths->front().Decls.begin(); 1909 while (isa<CXXMethodDecl>(*Found) && 1910 cast<CXXMethodDecl>(*Found)->isStatic()) 1911 ++Found; 1912 1913 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); 1914 break; 1915 } 1916 1917 case LookupResult::AmbiguousBaseSubobjectTypes: { 1918 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) 1919 << Name << LookupRange; 1920 1921 CXXBasePaths *Paths = Result.getBasePaths(); 1922 std::set<Decl *> DeclsPrinted; 1923 for (CXXBasePaths::paths_iterator Path = Paths->begin(), 1924 PathEnd = Paths->end(); 1925 Path != PathEnd; ++Path) { 1926 Decl *D = Path->Decls.front(); 1927 if (DeclsPrinted.insert(D).second) 1928 Diag(D->getLocation(), diag::note_ambiguous_member_found); 1929 } 1930 break; 1931 } 1932 1933 case LookupResult::AmbiguousTagHiding: { 1934 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange; 1935 1936 llvm::SmallPtrSet<NamedDecl*,8> TagDecls; 1937 1938 for (auto *D : Result) 1939 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 1940 TagDecls.insert(TD); 1941 Diag(TD->getLocation(), diag::note_hidden_tag); 1942 } 1943 1944 for (auto *D : Result) 1945 if (!isa<TagDecl>(D)) 1946 Diag(D->getLocation(), diag::note_hiding_object); 1947 1948 // For recovery purposes, go ahead and implement the hiding. 1949 LookupResult::Filter F = Result.makeFilter(); 1950 while (F.hasNext()) { 1951 if (TagDecls.count(F.next())) 1952 F.erase(); 1953 } 1954 F.done(); 1955 break; 1956 } 1957 1958 case LookupResult::AmbiguousReference: { 1959 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; 1960 1961 for (auto *D : Result) 1962 Diag(D->getLocation(), diag::note_ambiguous_candidate) << D; 1963 break; 1964 } 1965 } 1966 } 1967 1968 namespace { 1969 struct AssociatedLookup { 1970 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc, 1971 Sema::AssociatedNamespaceSet &Namespaces, 1972 Sema::AssociatedClassSet &Classes) 1973 : S(S), Namespaces(Namespaces), Classes(Classes), 1974 InstantiationLoc(InstantiationLoc) { 1975 } 1976 1977 Sema &S; 1978 Sema::AssociatedNamespaceSet &Namespaces; 1979 Sema::AssociatedClassSet &Classes; 1980 SourceLocation InstantiationLoc; 1981 }; 1982 } 1983 1984 static void 1985 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T); 1986 1987 static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces, 1988 DeclContext *Ctx) { 1989 // Add the associated namespace for this class. 1990 1991 // We don't use DeclContext::getEnclosingNamespaceContext() as this may 1992 // be a locally scoped record. 1993 1994 // We skip out of inline namespaces. The innermost non-inline namespace 1995 // contains all names of all its nested inline namespaces anyway, so we can 1996 // replace the entire inline namespace tree with its root. 1997 while (Ctx->isRecord() || Ctx->isTransparentContext() || 1998 Ctx->isInlineNamespace()) 1999 Ctx = Ctx->getParent(); 2000 2001 if (Ctx->isFileContext()) 2002 Namespaces.insert(Ctx->getPrimaryContext()); 2003 } 2004 2005 // \brief Add the associated classes and namespaces for argument-dependent 2006 // lookup that involves a template argument (C++ [basic.lookup.koenig]p2). 2007 static void 2008 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 2009 const TemplateArgument &Arg) { 2010 // C++ [basic.lookup.koenig]p2, last bullet: 2011 // -- [...] ; 2012 switch (Arg.getKind()) { 2013 case TemplateArgument::Null: 2014 break; 2015 2016 case TemplateArgument::Type: 2017 // [...] the namespaces and classes associated with the types of the 2018 // template arguments provided for template type parameters (excluding 2019 // template template parameters) 2020 addAssociatedClassesAndNamespaces(Result, Arg.getAsType()); 2021 break; 2022 2023 case TemplateArgument::Template: 2024 case TemplateArgument::TemplateExpansion: { 2025 // [...] the namespaces in which any template template arguments are 2026 // defined; and the classes in which any member templates used as 2027 // template template arguments are defined. 2028 TemplateName Template = Arg.getAsTemplateOrTemplatePattern(); 2029 if (ClassTemplateDecl *ClassTemplate 2030 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) { 2031 DeclContext *Ctx = ClassTemplate->getDeclContext(); 2032 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2033 Result.Classes.insert(EnclosingClass); 2034 // Add the associated namespace for this class. 2035 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2036 } 2037 break; 2038 } 2039 2040 case TemplateArgument::Declaration: 2041 case TemplateArgument::Integral: 2042 case TemplateArgument::Expression: 2043 case TemplateArgument::NullPtr: 2044 // [Note: non-type template arguments do not contribute to the set of 2045 // associated namespaces. ] 2046 break; 2047 2048 case TemplateArgument::Pack: 2049 for (const auto &P : Arg.pack_elements()) 2050 addAssociatedClassesAndNamespaces(Result, P); 2051 break; 2052 } 2053 } 2054 2055 // \brief Add the associated classes and namespaces for 2056 // argument-dependent lookup with an argument of class type 2057 // (C++ [basic.lookup.koenig]p2). 2058 static void 2059 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 2060 CXXRecordDecl *Class) { 2061 2062 // Just silently ignore anything whose name is __va_list_tag. 2063 if (Class->getDeclName() == Result.S.VAListTagName) 2064 return; 2065 2066 // C++ [basic.lookup.koenig]p2: 2067 // [...] 2068 // -- If T is a class type (including unions), its associated 2069 // classes are: the class itself; the class of which it is a 2070 // member, if any; and its direct and indirect base 2071 // classes. Its associated namespaces are the namespaces in 2072 // which its associated classes are defined. 2073 2074 // Add the class of which it is a member, if any. 2075 DeclContext *Ctx = Class->getDeclContext(); 2076 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2077 Result.Classes.insert(EnclosingClass); 2078 // Add the associated namespace for this class. 2079 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2080 2081 // Add the class itself. If we've already seen this class, we don't 2082 // need to visit base classes. 2083 // 2084 // FIXME: That's not correct, we may have added this class only because it 2085 // was the enclosing class of another class, and in that case we won't have 2086 // added its base classes yet. 2087 if (!Result.Classes.insert(Class).second) 2088 return; 2089 2090 // -- If T is a template-id, its associated namespaces and classes are 2091 // the namespace in which the template is defined; for member 2092 // templates, the member template's class; the namespaces and classes 2093 // associated with the types of the template arguments provided for 2094 // template type parameters (excluding template template parameters); the 2095 // namespaces in which any template template arguments are defined; and 2096 // the classes in which any member templates used as template template 2097 // arguments are defined. [Note: non-type template arguments do not 2098 // contribute to the set of associated namespaces. ] 2099 if (ClassTemplateSpecializationDecl *Spec 2100 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) { 2101 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); 2102 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2103 Result.Classes.insert(EnclosingClass); 2104 // Add the associated namespace for this class. 2105 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2106 2107 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); 2108 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 2109 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]); 2110 } 2111 2112 // Only recurse into base classes for complete types. 2113 if (!Class->hasDefinition()) 2114 return; 2115 2116 // Add direct and indirect base classes along with their associated 2117 // namespaces. 2118 SmallVector<CXXRecordDecl *, 32> Bases; 2119 Bases.push_back(Class); 2120 while (!Bases.empty()) { 2121 // Pop this class off the stack. 2122 Class = Bases.pop_back_val(); 2123 2124 // Visit the base classes. 2125 for (const auto &Base : Class->bases()) { 2126 const RecordType *BaseType = Base.getType()->getAs<RecordType>(); 2127 // In dependent contexts, we do ADL twice, and the first time around, 2128 // the base type might be a dependent TemplateSpecializationType, or a 2129 // TemplateTypeParmType. If that happens, simply ignore it. 2130 // FIXME: If we want to support export, we probably need to add the 2131 // namespace of the template in a TemplateSpecializationType, or even 2132 // the classes and namespaces of known non-dependent arguments. 2133 if (!BaseType) 2134 continue; 2135 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 2136 if (Result.Classes.insert(BaseDecl).second) { 2137 // Find the associated namespace for this base class. 2138 DeclContext *BaseCtx = BaseDecl->getDeclContext(); 2139 CollectEnclosingNamespace(Result.Namespaces, BaseCtx); 2140 2141 // Make sure we visit the bases of this base class. 2142 if (BaseDecl->bases_begin() != BaseDecl->bases_end()) 2143 Bases.push_back(BaseDecl); 2144 } 2145 } 2146 } 2147 } 2148 2149 // \brief Add the associated classes and namespaces for 2150 // argument-dependent lookup with an argument of type T 2151 // (C++ [basic.lookup.koenig]p2). 2152 static void 2153 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) { 2154 // C++ [basic.lookup.koenig]p2: 2155 // 2156 // For each argument type T in the function call, there is a set 2157 // of zero or more associated namespaces and a set of zero or more 2158 // associated classes to be considered. The sets of namespaces and 2159 // classes is determined entirely by the types of the function 2160 // arguments (and the namespace of any template template 2161 // argument). Typedef names and using-declarations used to specify 2162 // the types do not contribute to this set. The sets of namespaces 2163 // and classes are determined in the following way: 2164 2165 SmallVector<const Type *, 16> Queue; 2166 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr(); 2167 2168 while (true) { 2169 switch (T->getTypeClass()) { 2170 2171 #define TYPE(Class, Base) 2172 #define DEPENDENT_TYPE(Class, Base) case Type::Class: 2173 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 2174 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class: 2175 #define ABSTRACT_TYPE(Class, Base) 2176 #include "clang/AST/TypeNodes.def" 2177 // T is canonical. We can also ignore dependent types because 2178 // we don't need to do ADL at the definition point, but if we 2179 // wanted to implement template export (or if we find some other 2180 // use for associated classes and namespaces...) this would be 2181 // wrong. 2182 break; 2183 2184 // -- If T is a pointer to U or an array of U, its associated 2185 // namespaces and classes are those associated with U. 2186 case Type::Pointer: 2187 T = cast<PointerType>(T)->getPointeeType().getTypePtr(); 2188 continue; 2189 case Type::ConstantArray: 2190 case Type::IncompleteArray: 2191 case Type::VariableArray: 2192 T = cast<ArrayType>(T)->getElementType().getTypePtr(); 2193 continue; 2194 2195 // -- If T is a fundamental type, its associated sets of 2196 // namespaces and classes are both empty. 2197 case Type::Builtin: 2198 break; 2199 2200 // -- If T is a class type (including unions), its associated 2201 // classes are: the class itself; the class of which it is a 2202 // member, if any; and its direct and indirect base 2203 // classes. Its associated namespaces are the namespaces in 2204 // which its associated classes are defined. 2205 case Type::Record: { 2206 Result.S.RequireCompleteType(Result.InstantiationLoc, QualType(T, 0), 2207 /*no diagnostic*/ 0); 2208 CXXRecordDecl *Class 2209 = cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl()); 2210 addAssociatedClassesAndNamespaces(Result, Class); 2211 break; 2212 } 2213 2214 // -- If T is an enumeration type, its associated namespace is 2215 // the namespace in which it is defined. If it is class 2216 // member, its associated class is the member's class; else 2217 // it has no associated class. 2218 case Type::Enum: { 2219 EnumDecl *Enum = cast<EnumType>(T)->getDecl(); 2220 2221 DeclContext *Ctx = Enum->getDeclContext(); 2222 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2223 Result.Classes.insert(EnclosingClass); 2224 2225 // Add the associated namespace for this class. 2226 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2227 2228 break; 2229 } 2230 2231 // -- If T is a function type, its associated namespaces and 2232 // classes are those associated with the function parameter 2233 // types and those associated with the return type. 2234 case Type::FunctionProto: { 2235 const FunctionProtoType *Proto = cast<FunctionProtoType>(T); 2236 for (const auto &Arg : Proto->param_types()) 2237 Queue.push_back(Arg.getTypePtr()); 2238 // fallthrough 2239 } 2240 case Type::FunctionNoProto: { 2241 const FunctionType *FnType = cast<FunctionType>(T); 2242 T = FnType->getReturnType().getTypePtr(); 2243 continue; 2244 } 2245 2246 // -- If T is a pointer to a member function of a class X, its 2247 // associated namespaces and classes are those associated 2248 // with the function parameter types and return type, 2249 // together with those associated with X. 2250 // 2251 // -- If T is a pointer to a data member of class X, its 2252 // associated namespaces and classes are those associated 2253 // with the member type together with those associated with 2254 // X. 2255 case Type::MemberPointer: { 2256 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T); 2257 2258 // Queue up the class type into which this points. 2259 Queue.push_back(MemberPtr->getClass()); 2260 2261 // And directly continue with the pointee type. 2262 T = MemberPtr->getPointeeType().getTypePtr(); 2263 continue; 2264 } 2265 2266 // As an extension, treat this like a normal pointer. 2267 case Type::BlockPointer: 2268 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr(); 2269 continue; 2270 2271 // References aren't covered by the standard, but that's such an 2272 // obvious defect that we cover them anyway. 2273 case Type::LValueReference: 2274 case Type::RValueReference: 2275 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr(); 2276 continue; 2277 2278 // These are fundamental types. 2279 case Type::Vector: 2280 case Type::ExtVector: 2281 case Type::Complex: 2282 break; 2283 2284 // Non-deduced auto types only get here for error cases. 2285 case Type::Auto: 2286 break; 2287 2288 // If T is an Objective-C object or interface type, or a pointer to an 2289 // object or interface type, the associated namespace is the global 2290 // namespace. 2291 case Type::ObjCObject: 2292 case Type::ObjCInterface: 2293 case Type::ObjCObjectPointer: 2294 Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl()); 2295 break; 2296 2297 // Atomic types are just wrappers; use the associations of the 2298 // contained type. 2299 case Type::Atomic: 2300 T = cast<AtomicType>(T)->getValueType().getTypePtr(); 2301 continue; 2302 } 2303 2304 if (Queue.empty()) 2305 break; 2306 T = Queue.pop_back_val(); 2307 } 2308 } 2309 2310 /// \brief Find the associated classes and namespaces for 2311 /// argument-dependent lookup for a call with the given set of 2312 /// arguments. 2313 /// 2314 /// This routine computes the sets of associated classes and associated 2315 /// namespaces searched by argument-dependent lookup 2316 /// (C++ [basic.lookup.argdep]) for a given set of arguments. 2317 void Sema::FindAssociatedClassesAndNamespaces( 2318 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args, 2319 AssociatedNamespaceSet &AssociatedNamespaces, 2320 AssociatedClassSet &AssociatedClasses) { 2321 AssociatedNamespaces.clear(); 2322 AssociatedClasses.clear(); 2323 2324 AssociatedLookup Result(*this, InstantiationLoc, 2325 AssociatedNamespaces, AssociatedClasses); 2326 2327 // C++ [basic.lookup.koenig]p2: 2328 // For each argument type T in the function call, there is a set 2329 // of zero or more associated namespaces and a set of zero or more 2330 // associated classes to be considered. The sets of namespaces and 2331 // classes is determined entirely by the types of the function 2332 // arguments (and the namespace of any template template 2333 // argument). 2334 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) { 2335 Expr *Arg = Args[ArgIdx]; 2336 2337 if (Arg->getType() != Context.OverloadTy) { 2338 addAssociatedClassesAndNamespaces(Result, Arg->getType()); 2339 continue; 2340 } 2341 2342 // [...] In addition, if the argument is the name or address of a 2343 // set of overloaded functions and/or function templates, its 2344 // associated classes and namespaces are the union of those 2345 // associated with each of the members of the set: the namespace 2346 // in which the function or function template is defined and the 2347 // classes and namespaces associated with its (non-dependent) 2348 // parameter types and return type. 2349 Arg = Arg->IgnoreParens(); 2350 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg)) 2351 if (unaryOp->getOpcode() == UO_AddrOf) 2352 Arg = unaryOp->getSubExpr(); 2353 2354 UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg); 2355 if (!ULE) continue; 2356 2357 for (const auto *D : ULE->decls()) { 2358 // Look through any using declarations to find the underlying function. 2359 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction(); 2360 2361 // Add the classes and namespaces associated with the parameter 2362 // types and return type of this function. 2363 addAssociatedClassesAndNamespaces(Result, FDecl->getType()); 2364 } 2365 } 2366 } 2367 2368 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name, 2369 SourceLocation Loc, 2370 LookupNameKind NameKind, 2371 RedeclarationKind Redecl) { 2372 LookupResult R(*this, Name, Loc, NameKind, Redecl); 2373 LookupName(R, S); 2374 return R.getAsSingle<NamedDecl>(); 2375 } 2376 2377 /// \brief Find the protocol with the given name, if any. 2378 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II, 2379 SourceLocation IdLoc, 2380 RedeclarationKind Redecl) { 2381 Decl *D = LookupSingleName(TUScope, II, IdLoc, 2382 LookupObjCProtocolName, Redecl); 2383 return cast_or_null<ObjCProtocolDecl>(D); 2384 } 2385 2386 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, 2387 QualType T1, QualType T2, 2388 UnresolvedSetImpl &Functions) { 2389 // C++ [over.match.oper]p3: 2390 // -- The set of non-member candidates is the result of the 2391 // unqualified lookup of operator@ in the context of the 2392 // expression according to the usual rules for name lookup in 2393 // unqualified function calls (3.4.2) except that all member 2394 // functions are ignored. 2395 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2396 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName); 2397 LookupName(Operators, S); 2398 2399 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); 2400 Functions.append(Operators.begin(), Operators.end()); 2401 } 2402 2403 Sema::SpecialMemberOverloadResult *Sema::LookupSpecialMember(CXXRecordDecl *RD, 2404 CXXSpecialMember SM, 2405 bool ConstArg, 2406 bool VolatileArg, 2407 bool RValueThis, 2408 bool ConstThis, 2409 bool VolatileThis) { 2410 assert(CanDeclareSpecialMemberFunction(RD) && 2411 "doing special member lookup into record that isn't fully complete"); 2412 RD = RD->getDefinition(); 2413 if (RValueThis || ConstThis || VolatileThis) 2414 assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) && 2415 "constructors and destructors always have unqualified lvalue this"); 2416 if (ConstArg || VolatileArg) 2417 assert((SM != CXXDefaultConstructor && SM != CXXDestructor) && 2418 "parameter-less special members can't have qualified arguments"); 2419 2420 llvm::FoldingSetNodeID ID; 2421 ID.AddPointer(RD); 2422 ID.AddInteger(SM); 2423 ID.AddInteger(ConstArg); 2424 ID.AddInteger(VolatileArg); 2425 ID.AddInteger(RValueThis); 2426 ID.AddInteger(ConstThis); 2427 ID.AddInteger(VolatileThis); 2428 2429 void *InsertPoint; 2430 SpecialMemberOverloadResult *Result = 2431 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint); 2432 2433 // This was already cached 2434 if (Result) 2435 return Result; 2436 2437 Result = BumpAlloc.Allocate<SpecialMemberOverloadResult>(); 2438 Result = new (Result) SpecialMemberOverloadResult(ID); 2439 SpecialMemberCache.InsertNode(Result, InsertPoint); 2440 2441 if (SM == CXXDestructor) { 2442 if (RD->needsImplicitDestructor()) 2443 DeclareImplicitDestructor(RD); 2444 CXXDestructorDecl *DD = RD->getDestructor(); 2445 assert(DD && "record without a destructor"); 2446 Result->setMethod(DD); 2447 Result->setKind(DD->isDeleted() ? 2448 SpecialMemberOverloadResult::NoMemberOrDeleted : 2449 SpecialMemberOverloadResult::Success); 2450 return Result; 2451 } 2452 2453 // Prepare for overload resolution. Here we construct a synthetic argument 2454 // if necessary and make sure that implicit functions are declared. 2455 CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD)); 2456 DeclarationName Name; 2457 Expr *Arg = nullptr; 2458 unsigned NumArgs; 2459 2460 QualType ArgType = CanTy; 2461 ExprValueKind VK = VK_LValue; 2462 2463 if (SM == CXXDefaultConstructor) { 2464 Name = Context.DeclarationNames.getCXXConstructorName(CanTy); 2465 NumArgs = 0; 2466 if (RD->needsImplicitDefaultConstructor()) 2467 DeclareImplicitDefaultConstructor(RD); 2468 } else { 2469 if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) { 2470 Name = Context.DeclarationNames.getCXXConstructorName(CanTy); 2471 if (RD->needsImplicitCopyConstructor()) 2472 DeclareImplicitCopyConstructor(RD); 2473 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor()) 2474 DeclareImplicitMoveConstructor(RD); 2475 } else { 2476 Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal); 2477 if (RD->needsImplicitCopyAssignment()) 2478 DeclareImplicitCopyAssignment(RD); 2479 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment()) 2480 DeclareImplicitMoveAssignment(RD); 2481 } 2482 2483 if (ConstArg) 2484 ArgType.addConst(); 2485 if (VolatileArg) 2486 ArgType.addVolatile(); 2487 2488 // This isn't /really/ specified by the standard, but it's implied 2489 // we should be working from an RValue in the case of move to ensure 2490 // that we prefer to bind to rvalue references, and an LValue in the 2491 // case of copy to ensure we don't bind to rvalue references. 2492 // Possibly an XValue is actually correct in the case of move, but 2493 // there is no semantic difference for class types in this restricted 2494 // case. 2495 if (SM == CXXCopyConstructor || SM == CXXCopyAssignment) 2496 VK = VK_LValue; 2497 else 2498 VK = VK_RValue; 2499 } 2500 2501 OpaqueValueExpr FakeArg(SourceLocation(), ArgType, VK); 2502 2503 if (SM != CXXDefaultConstructor) { 2504 NumArgs = 1; 2505 Arg = &FakeArg; 2506 } 2507 2508 // Create the object argument 2509 QualType ThisTy = CanTy; 2510 if (ConstThis) 2511 ThisTy.addConst(); 2512 if (VolatileThis) 2513 ThisTy.addVolatile(); 2514 Expr::Classification Classification = 2515 OpaqueValueExpr(SourceLocation(), ThisTy, 2516 RValueThis ? VK_RValue : VK_LValue).Classify(Context); 2517 2518 // Now we perform lookup on the name we computed earlier and do overload 2519 // resolution. Lookup is only performed directly into the class since there 2520 // will always be a (possibly implicit) declaration to shadow any others. 2521 OverloadCandidateSet OCS(RD->getLocation(), OverloadCandidateSet::CSK_Normal); 2522 DeclContext::lookup_result R = RD->lookup(Name); 2523 2524 if (R.empty()) { 2525 // We might have no default constructor because we have a lambda's closure 2526 // type, rather than because there's some other declared constructor. 2527 // Every class has a copy/move constructor, copy/move assignment, and 2528 // destructor. 2529 assert(SM == CXXDefaultConstructor && 2530 "lookup for a constructor or assignment operator was empty"); 2531 Result->setMethod(nullptr); 2532 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 2533 return Result; 2534 } 2535 2536 // Copy the candidates as our processing of them may load new declarations 2537 // from an external source and invalidate lookup_result. 2538 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end()); 2539 2540 for (auto *Cand : Candidates) { 2541 if (Cand->isInvalidDecl()) 2542 continue; 2543 2544 if (UsingShadowDecl *U = dyn_cast<UsingShadowDecl>(Cand)) { 2545 // FIXME: [namespace.udecl]p15 says that we should only consider a 2546 // using declaration here if it does not match a declaration in the 2547 // derived class. We do not implement this correctly in other cases 2548 // either. 2549 Cand = U->getTargetDecl(); 2550 2551 if (Cand->isInvalidDecl()) 2552 continue; 2553 } 2554 2555 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand)) { 2556 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) 2557 AddMethodCandidate(M, DeclAccessPair::make(M, AS_public), RD, ThisTy, 2558 Classification, llvm::makeArrayRef(&Arg, NumArgs), 2559 OCS, true); 2560 else 2561 AddOverloadCandidate(M, DeclAccessPair::make(M, AS_public), 2562 llvm::makeArrayRef(&Arg, NumArgs), OCS, true); 2563 } else if (FunctionTemplateDecl *Tmpl = 2564 dyn_cast<FunctionTemplateDecl>(Cand)) { 2565 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) 2566 AddMethodTemplateCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public), 2567 RD, nullptr, ThisTy, Classification, 2568 llvm::makeArrayRef(&Arg, NumArgs), 2569 OCS, true); 2570 else 2571 AddTemplateOverloadCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public), 2572 nullptr, llvm::makeArrayRef(&Arg, NumArgs), 2573 OCS, true); 2574 } else { 2575 assert(isa<UsingDecl>(Cand) && "illegal Kind of operator = Decl"); 2576 } 2577 } 2578 2579 OverloadCandidateSet::iterator Best; 2580 switch (OCS.BestViableFunction(*this, SourceLocation(), Best)) { 2581 case OR_Success: 2582 Result->setMethod(cast<CXXMethodDecl>(Best->Function)); 2583 Result->setKind(SpecialMemberOverloadResult::Success); 2584 break; 2585 2586 case OR_Deleted: 2587 Result->setMethod(cast<CXXMethodDecl>(Best->Function)); 2588 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 2589 break; 2590 2591 case OR_Ambiguous: 2592 Result->setMethod(nullptr); 2593 Result->setKind(SpecialMemberOverloadResult::Ambiguous); 2594 break; 2595 2596 case OR_No_Viable_Function: 2597 Result->setMethod(nullptr); 2598 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 2599 break; 2600 } 2601 2602 return Result; 2603 } 2604 2605 /// \brief Look up the default constructor for the given class. 2606 CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) { 2607 SpecialMemberOverloadResult *Result = 2608 LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false, 2609 false, false); 2610 2611 return cast_or_null<CXXConstructorDecl>(Result->getMethod()); 2612 } 2613 2614 /// \brief Look up the copying constructor for the given class. 2615 CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class, 2616 unsigned Quals) { 2617 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 2618 "non-const, non-volatile qualifiers for copy ctor arg"); 2619 SpecialMemberOverloadResult *Result = 2620 LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const, 2621 Quals & Qualifiers::Volatile, false, false, false); 2622 2623 return cast_or_null<CXXConstructorDecl>(Result->getMethod()); 2624 } 2625 2626 /// \brief Look up the moving constructor for the given class. 2627 CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class, 2628 unsigned Quals) { 2629 SpecialMemberOverloadResult *Result = 2630 LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const, 2631 Quals & Qualifiers::Volatile, false, false, false); 2632 2633 return cast_or_null<CXXConstructorDecl>(Result->getMethod()); 2634 } 2635 2636 /// \brief Look up the constructors for the given class. 2637 DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) { 2638 // If the implicit constructors have not yet been declared, do so now. 2639 if (CanDeclareSpecialMemberFunction(Class)) { 2640 if (Class->needsImplicitDefaultConstructor()) 2641 DeclareImplicitDefaultConstructor(Class); 2642 if (Class->needsImplicitCopyConstructor()) 2643 DeclareImplicitCopyConstructor(Class); 2644 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor()) 2645 DeclareImplicitMoveConstructor(Class); 2646 } 2647 2648 CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class)); 2649 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T); 2650 return Class->lookup(Name); 2651 } 2652 2653 /// \brief Look up the copying assignment operator for the given class. 2654 CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class, 2655 unsigned Quals, bool RValueThis, 2656 unsigned ThisQuals) { 2657 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 2658 "non-const, non-volatile qualifiers for copy assignment arg"); 2659 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 2660 "non-const, non-volatile qualifiers for copy assignment this"); 2661 SpecialMemberOverloadResult *Result = 2662 LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const, 2663 Quals & Qualifiers::Volatile, RValueThis, 2664 ThisQuals & Qualifiers::Const, 2665 ThisQuals & Qualifiers::Volatile); 2666 2667 return Result->getMethod(); 2668 } 2669 2670 /// \brief Look up the moving assignment operator for the given class. 2671 CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class, 2672 unsigned Quals, 2673 bool RValueThis, 2674 unsigned ThisQuals) { 2675 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 2676 "non-const, non-volatile qualifiers for copy assignment this"); 2677 SpecialMemberOverloadResult *Result = 2678 LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const, 2679 Quals & Qualifiers::Volatile, RValueThis, 2680 ThisQuals & Qualifiers::Const, 2681 ThisQuals & Qualifiers::Volatile); 2682 2683 return Result->getMethod(); 2684 } 2685 2686 /// \brief Look for the destructor of the given class. 2687 /// 2688 /// During semantic analysis, this routine should be used in lieu of 2689 /// CXXRecordDecl::getDestructor(). 2690 /// 2691 /// \returns The destructor for this class. 2692 CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) { 2693 return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor, 2694 false, false, false, 2695 false, false)->getMethod()); 2696 } 2697 2698 /// LookupLiteralOperator - Determine which literal operator should be used for 2699 /// a user-defined literal, per C++11 [lex.ext]. 2700 /// 2701 /// Normal overload resolution is not used to select which literal operator to 2702 /// call for a user-defined literal. Look up the provided literal operator name, 2703 /// and filter the results to the appropriate set for the given argument types. 2704 Sema::LiteralOperatorLookupResult 2705 Sema::LookupLiteralOperator(Scope *S, LookupResult &R, 2706 ArrayRef<QualType> ArgTys, 2707 bool AllowRaw, bool AllowTemplate, 2708 bool AllowStringTemplate) { 2709 LookupName(R, S); 2710 assert(R.getResultKind() != LookupResult::Ambiguous && 2711 "literal operator lookup can't be ambiguous"); 2712 2713 // Filter the lookup results appropriately. 2714 LookupResult::Filter F = R.makeFilter(); 2715 2716 bool FoundRaw = false; 2717 bool FoundTemplate = false; 2718 bool FoundStringTemplate = false; 2719 bool FoundExactMatch = false; 2720 2721 while (F.hasNext()) { 2722 Decl *D = F.next(); 2723 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D)) 2724 D = USD->getTargetDecl(); 2725 2726 // If the declaration we found is invalid, skip it. 2727 if (D->isInvalidDecl()) { 2728 F.erase(); 2729 continue; 2730 } 2731 2732 bool IsRaw = false; 2733 bool IsTemplate = false; 2734 bool IsStringTemplate = false; 2735 bool IsExactMatch = false; 2736 2737 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2738 if (FD->getNumParams() == 1 && 2739 FD->getParamDecl(0)->getType()->getAs<PointerType>()) 2740 IsRaw = true; 2741 else if (FD->getNumParams() == ArgTys.size()) { 2742 IsExactMatch = true; 2743 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) { 2744 QualType ParamTy = FD->getParamDecl(ArgIdx)->getType(); 2745 if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) { 2746 IsExactMatch = false; 2747 break; 2748 } 2749 } 2750 } 2751 } 2752 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) { 2753 TemplateParameterList *Params = FD->getTemplateParameters(); 2754 if (Params->size() == 1) 2755 IsTemplate = true; 2756 else 2757 IsStringTemplate = true; 2758 } 2759 2760 if (IsExactMatch) { 2761 FoundExactMatch = true; 2762 AllowRaw = false; 2763 AllowTemplate = false; 2764 AllowStringTemplate = false; 2765 if (FoundRaw || FoundTemplate || FoundStringTemplate) { 2766 // Go through again and remove the raw and template decls we've 2767 // already found. 2768 F.restart(); 2769 FoundRaw = FoundTemplate = FoundStringTemplate = false; 2770 } 2771 } else if (AllowRaw && IsRaw) { 2772 FoundRaw = true; 2773 } else if (AllowTemplate && IsTemplate) { 2774 FoundTemplate = true; 2775 } else if (AllowStringTemplate && IsStringTemplate) { 2776 FoundStringTemplate = true; 2777 } else { 2778 F.erase(); 2779 } 2780 } 2781 2782 F.done(); 2783 2784 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching 2785 // parameter type, that is used in preference to a raw literal operator 2786 // or literal operator template. 2787 if (FoundExactMatch) 2788 return LOLR_Cooked; 2789 2790 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal 2791 // operator template, but not both. 2792 if (FoundRaw && FoundTemplate) { 2793 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName(); 2794 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 2795 NoteOverloadCandidate((*I)->getUnderlyingDecl()->getAsFunction()); 2796 return LOLR_Error; 2797 } 2798 2799 if (FoundRaw) 2800 return LOLR_Raw; 2801 2802 if (FoundTemplate) 2803 return LOLR_Template; 2804 2805 if (FoundStringTemplate) 2806 return LOLR_StringTemplate; 2807 2808 // Didn't find anything we could use. 2809 Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator) 2810 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0] 2811 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw 2812 << (AllowTemplate || AllowStringTemplate); 2813 return LOLR_Error; 2814 } 2815 2816 void ADLResult::insert(NamedDecl *New) { 2817 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())]; 2818 2819 // If we haven't yet seen a decl for this key, or the last decl 2820 // was exactly this one, we're done. 2821 if (Old == nullptr || Old == New) { 2822 Old = New; 2823 return; 2824 } 2825 2826 // Otherwise, decide which is a more recent redeclaration. 2827 FunctionDecl *OldFD = Old->getAsFunction(); 2828 FunctionDecl *NewFD = New->getAsFunction(); 2829 2830 FunctionDecl *Cursor = NewFD; 2831 while (true) { 2832 Cursor = Cursor->getPreviousDecl(); 2833 2834 // If we got to the end without finding OldFD, OldFD is the newer 2835 // declaration; leave things as they are. 2836 if (!Cursor) return; 2837 2838 // If we do find OldFD, then NewFD is newer. 2839 if (Cursor == OldFD) break; 2840 2841 // Otherwise, keep looking. 2842 } 2843 2844 Old = New; 2845 } 2846 2847 void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc, 2848 ArrayRef<Expr *> Args, ADLResult &Result) { 2849 // Find all of the associated namespaces and classes based on the 2850 // arguments we have. 2851 AssociatedNamespaceSet AssociatedNamespaces; 2852 AssociatedClassSet AssociatedClasses; 2853 FindAssociatedClassesAndNamespaces(Loc, Args, 2854 AssociatedNamespaces, 2855 AssociatedClasses); 2856 2857 // C++ [basic.lookup.argdep]p3: 2858 // Let X be the lookup set produced by unqualified lookup (3.4.1) 2859 // and let Y be the lookup set produced by argument dependent 2860 // lookup (defined as follows). If X contains [...] then Y is 2861 // empty. Otherwise Y is the set of declarations found in the 2862 // namespaces associated with the argument types as described 2863 // below. The set of declarations found by the lookup of the name 2864 // is the union of X and Y. 2865 // 2866 // Here, we compute Y and add its members to the overloaded 2867 // candidate set. 2868 for (auto *NS : AssociatedNamespaces) { 2869 // When considering an associated namespace, the lookup is the 2870 // same as the lookup performed when the associated namespace is 2871 // used as a qualifier (3.4.3.2) except that: 2872 // 2873 // -- Any using-directives in the associated namespace are 2874 // ignored. 2875 // 2876 // -- Any namespace-scope friend functions declared in 2877 // associated classes are visible within their respective 2878 // namespaces even if they are not visible during an ordinary 2879 // lookup (11.4). 2880 DeclContext::lookup_result R = NS->lookup(Name); 2881 for (auto *D : R) { 2882 // If the only declaration here is an ordinary friend, consider 2883 // it only if it was declared in an associated classes. 2884 if ((D->getIdentifierNamespace() & Decl::IDNS_Ordinary) == 0) { 2885 // If it's neither ordinarily visible nor a friend, we can't find it. 2886 if ((D->getIdentifierNamespace() & Decl::IDNS_OrdinaryFriend) == 0) 2887 continue; 2888 2889 bool DeclaredInAssociatedClass = false; 2890 for (Decl *DI = D; DI; DI = DI->getPreviousDecl()) { 2891 DeclContext *LexDC = DI->getLexicalDeclContext(); 2892 if (isa<CXXRecordDecl>(LexDC) && 2893 AssociatedClasses.count(cast<CXXRecordDecl>(LexDC))) { 2894 DeclaredInAssociatedClass = true; 2895 break; 2896 } 2897 } 2898 if (!DeclaredInAssociatedClass) 2899 continue; 2900 } 2901 2902 if (isa<UsingShadowDecl>(D)) 2903 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2904 2905 if (!isa<FunctionDecl>(D) && !isa<FunctionTemplateDecl>(D)) 2906 continue; 2907 2908 Result.insert(D); 2909 } 2910 } 2911 } 2912 2913 //---------------------------------------------------------------------------- 2914 // Search for all visible declarations. 2915 //---------------------------------------------------------------------------- 2916 VisibleDeclConsumer::~VisibleDeclConsumer() { } 2917 2918 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; } 2919 2920 namespace { 2921 2922 class ShadowContextRAII; 2923 2924 class VisibleDeclsRecord { 2925 public: 2926 /// \brief An entry in the shadow map, which is optimized to store a 2927 /// single declaration (the common case) but can also store a list 2928 /// of declarations. 2929 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry; 2930 2931 private: 2932 /// \brief A mapping from declaration names to the declarations that have 2933 /// this name within a particular scope. 2934 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap; 2935 2936 /// \brief A list of shadow maps, which is used to model name hiding. 2937 std::list<ShadowMap> ShadowMaps; 2938 2939 /// \brief The declaration contexts we have already visited. 2940 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts; 2941 2942 friend class ShadowContextRAII; 2943 2944 public: 2945 /// \brief Determine whether we have already visited this context 2946 /// (and, if not, note that we are going to visit that context now). 2947 bool visitedContext(DeclContext *Ctx) { 2948 return !VisitedContexts.insert(Ctx).second; 2949 } 2950 2951 bool alreadyVisitedContext(DeclContext *Ctx) { 2952 return VisitedContexts.count(Ctx); 2953 } 2954 2955 /// \brief Determine whether the given declaration is hidden in the 2956 /// current scope. 2957 /// 2958 /// \returns the declaration that hides the given declaration, or 2959 /// NULL if no such declaration exists. 2960 NamedDecl *checkHidden(NamedDecl *ND); 2961 2962 /// \brief Add a declaration to the current shadow map. 2963 void add(NamedDecl *ND) { 2964 ShadowMaps.back()[ND->getDeclName()].push_back(ND); 2965 } 2966 }; 2967 2968 /// \brief RAII object that records when we've entered a shadow context. 2969 class ShadowContextRAII { 2970 VisibleDeclsRecord &Visible; 2971 2972 typedef VisibleDeclsRecord::ShadowMap ShadowMap; 2973 2974 public: 2975 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) { 2976 Visible.ShadowMaps.push_back(ShadowMap()); 2977 } 2978 2979 ~ShadowContextRAII() { 2980 Visible.ShadowMaps.pop_back(); 2981 } 2982 }; 2983 2984 } // end anonymous namespace 2985 2986 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) { 2987 // Look through using declarations. 2988 ND = ND->getUnderlyingDecl(); 2989 2990 unsigned IDNS = ND->getIdentifierNamespace(); 2991 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin(); 2992 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend(); 2993 SM != SMEnd; ++SM) { 2994 ShadowMap::iterator Pos = SM->find(ND->getDeclName()); 2995 if (Pos == SM->end()) 2996 continue; 2997 2998 for (auto *D : Pos->second) { 2999 // A tag declaration does not hide a non-tag declaration. 3000 if (D->hasTagIdentifierNamespace() && 3001 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary | 3002 Decl::IDNS_ObjCProtocol))) 3003 continue; 3004 3005 // Protocols are in distinct namespaces from everything else. 3006 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol) 3007 || (IDNS & Decl::IDNS_ObjCProtocol)) && 3008 D->getIdentifierNamespace() != IDNS) 3009 continue; 3010 3011 // Functions and function templates in the same scope overload 3012 // rather than hide. FIXME: Look for hiding based on function 3013 // signatures! 3014 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() && 3015 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() && 3016 SM == ShadowMaps.rbegin()) 3017 continue; 3018 3019 // We've found a declaration that hides this one. 3020 return D; 3021 } 3022 } 3023 3024 return nullptr; 3025 } 3026 3027 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result, 3028 bool QualifiedNameLookup, 3029 bool InBaseClass, 3030 VisibleDeclConsumer &Consumer, 3031 VisibleDeclsRecord &Visited) { 3032 if (!Ctx) 3033 return; 3034 3035 // Make sure we don't visit the same context twice. 3036 if (Visited.visitedContext(Ctx->getPrimaryContext())) 3037 return; 3038 3039 // Outside C++, lookup results for the TU live on identifiers. 3040 if (isa<TranslationUnitDecl>(Ctx) && 3041 !Result.getSema().getLangOpts().CPlusPlus) { 3042 auto &S = Result.getSema(); 3043 auto &Idents = S.Context.Idents; 3044 3045 // Ensure all external identifiers are in the identifier table. 3046 if (IdentifierInfoLookup *External = Idents.getExternalIdentifierLookup()) { 3047 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers()); 3048 for (StringRef Name = Iter->Next(); !Name.empty(); Name = Iter->Next()) 3049 Idents.get(Name); 3050 } 3051 3052 // Walk all lookup results in the TU for each identifier. 3053 for (const auto &Ident : Idents) { 3054 for (auto I = S.IdResolver.begin(Ident.getValue()), 3055 E = S.IdResolver.end(); 3056 I != E; ++I) { 3057 if (S.IdResolver.isDeclInScope(*I, Ctx)) { 3058 if (NamedDecl *ND = Result.getAcceptableDecl(*I)) { 3059 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass); 3060 Visited.add(ND); 3061 } 3062 } 3063 } 3064 } 3065 3066 return; 3067 } 3068 3069 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx)) 3070 Result.getSema().ForceDeclarationOfImplicitMembers(Class); 3071 3072 // Enumerate all of the results in this context. 3073 for (DeclContextLookupResult R : Ctx->lookups()) { 3074 for (auto *D : R) { 3075 if (auto *ND = Result.getAcceptableDecl(D)) { 3076 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass); 3077 Visited.add(ND); 3078 } 3079 } 3080 } 3081 3082 // Traverse using directives for qualified name lookup. 3083 if (QualifiedNameLookup) { 3084 ShadowContextRAII Shadow(Visited); 3085 for (auto I : Ctx->using_directives()) { 3086 LookupVisibleDecls(I->getNominatedNamespace(), Result, 3087 QualifiedNameLookup, InBaseClass, Consumer, Visited); 3088 } 3089 } 3090 3091 // Traverse the contexts of inherited C++ classes. 3092 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) { 3093 if (!Record->hasDefinition()) 3094 return; 3095 3096 for (const auto &B : Record->bases()) { 3097 QualType BaseType = B.getType(); 3098 3099 // Don't look into dependent bases, because name lookup can't look 3100 // there anyway. 3101 if (BaseType->isDependentType()) 3102 continue; 3103 3104 const RecordType *Record = BaseType->getAs<RecordType>(); 3105 if (!Record) 3106 continue; 3107 3108 // FIXME: It would be nice to be able to determine whether referencing 3109 // a particular member would be ambiguous. For example, given 3110 // 3111 // struct A { int member; }; 3112 // struct B { int member; }; 3113 // struct C : A, B { }; 3114 // 3115 // void f(C *c) { c->### } 3116 // 3117 // accessing 'member' would result in an ambiguity. However, we 3118 // could be smart enough to qualify the member with the base 3119 // class, e.g., 3120 // 3121 // c->B::member 3122 // 3123 // or 3124 // 3125 // c->A::member 3126 3127 // Find results in this base class (and its bases). 3128 ShadowContextRAII Shadow(Visited); 3129 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup, 3130 true, Consumer, Visited); 3131 } 3132 } 3133 3134 // Traverse the contexts of Objective-C classes. 3135 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) { 3136 // Traverse categories. 3137 for (auto *Cat : IFace->visible_categories()) { 3138 ShadowContextRAII Shadow(Visited); 3139 LookupVisibleDecls(Cat, Result, QualifiedNameLookup, false, 3140 Consumer, Visited); 3141 } 3142 3143 // Traverse protocols. 3144 for (auto *I : IFace->all_referenced_protocols()) { 3145 ShadowContextRAII Shadow(Visited); 3146 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer, 3147 Visited); 3148 } 3149 3150 // Traverse the superclass. 3151 if (IFace->getSuperClass()) { 3152 ShadowContextRAII Shadow(Visited); 3153 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup, 3154 true, Consumer, Visited); 3155 } 3156 3157 // If there is an implementation, traverse it. We do this to find 3158 // synthesized ivars. 3159 if (IFace->getImplementation()) { 3160 ShadowContextRAII Shadow(Visited); 3161 LookupVisibleDecls(IFace->getImplementation(), Result, 3162 QualifiedNameLookup, InBaseClass, Consumer, Visited); 3163 } 3164 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) { 3165 for (auto *I : Protocol->protocols()) { 3166 ShadowContextRAII Shadow(Visited); 3167 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer, 3168 Visited); 3169 } 3170 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) { 3171 for (auto *I : Category->protocols()) { 3172 ShadowContextRAII Shadow(Visited); 3173 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer, 3174 Visited); 3175 } 3176 3177 // If there is an implementation, traverse it. 3178 if (Category->getImplementation()) { 3179 ShadowContextRAII Shadow(Visited); 3180 LookupVisibleDecls(Category->getImplementation(), Result, 3181 QualifiedNameLookup, true, Consumer, Visited); 3182 } 3183 } 3184 } 3185 3186 static void LookupVisibleDecls(Scope *S, LookupResult &Result, 3187 UnqualUsingDirectiveSet &UDirs, 3188 VisibleDeclConsumer &Consumer, 3189 VisibleDeclsRecord &Visited) { 3190 if (!S) 3191 return; 3192 3193 if (!S->getEntity() || 3194 (!S->getParent() && 3195 !Visited.alreadyVisitedContext(S->getEntity())) || 3196 (S->getEntity())->isFunctionOrMethod()) { 3197 FindLocalExternScope FindLocals(Result); 3198 // Walk through the declarations in this Scope. 3199 for (auto *D : S->decls()) { 3200 if (NamedDecl *ND = dyn_cast<NamedDecl>(D)) 3201 if ((ND = Result.getAcceptableDecl(ND))) { 3202 Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false); 3203 Visited.add(ND); 3204 } 3205 } 3206 } 3207 3208 // FIXME: C++ [temp.local]p8 3209 DeclContext *Entity = nullptr; 3210 if (S->getEntity()) { 3211 // Look into this scope's declaration context, along with any of its 3212 // parent lookup contexts (e.g., enclosing classes), up to the point 3213 // where we hit the context stored in the next outer scope. 3214 Entity = S->getEntity(); 3215 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME 3216 3217 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx); 3218 Ctx = Ctx->getLookupParent()) { 3219 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 3220 if (Method->isInstanceMethod()) { 3221 // For instance methods, look for ivars in the method's interface. 3222 LookupResult IvarResult(Result.getSema(), Result.getLookupName(), 3223 Result.getNameLoc(), Sema::LookupMemberName); 3224 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) { 3225 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false, 3226 /*InBaseClass=*/false, Consumer, Visited); 3227 } 3228 } 3229 3230 // We've already performed all of the name lookup that we need 3231 // to for Objective-C methods; the next context will be the 3232 // outer scope. 3233 break; 3234 } 3235 3236 if (Ctx->isFunctionOrMethod()) 3237 continue; 3238 3239 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false, 3240 /*InBaseClass=*/false, Consumer, Visited); 3241 } 3242 } else if (!S->getParent()) { 3243 // Look into the translation unit scope. We walk through the translation 3244 // unit's declaration context, because the Scope itself won't have all of 3245 // the declarations if we loaded a precompiled header. 3246 // FIXME: We would like the translation unit's Scope object to point to the 3247 // translation unit, so we don't need this special "if" branch. However, 3248 // doing so would force the normal C++ name-lookup code to look into the 3249 // translation unit decl when the IdentifierInfo chains would suffice. 3250 // Once we fix that problem (which is part of a more general "don't look 3251 // in DeclContexts unless we have to" optimization), we can eliminate this. 3252 Entity = Result.getSema().Context.getTranslationUnitDecl(); 3253 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false, 3254 /*InBaseClass=*/false, Consumer, Visited); 3255 } 3256 3257 if (Entity) { 3258 // Lookup visible declarations in any namespaces found by using 3259 // directives. 3260 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity)) 3261 LookupVisibleDecls(const_cast<DeclContext *>(UUE.getNominatedNamespace()), 3262 Result, /*QualifiedNameLookup=*/false, 3263 /*InBaseClass=*/false, Consumer, Visited); 3264 } 3265 3266 // Lookup names in the parent scope. 3267 ShadowContextRAII Shadow(Visited); 3268 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited); 3269 } 3270 3271 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind, 3272 VisibleDeclConsumer &Consumer, 3273 bool IncludeGlobalScope) { 3274 // Determine the set of using directives available during 3275 // unqualified name lookup. 3276 Scope *Initial = S; 3277 UnqualUsingDirectiveSet UDirs; 3278 if (getLangOpts().CPlusPlus) { 3279 // Find the first namespace or translation-unit scope. 3280 while (S && !isNamespaceOrTranslationUnitScope(S)) 3281 S = S->getParent(); 3282 3283 UDirs.visitScopeChain(Initial, S); 3284 } 3285 UDirs.done(); 3286 3287 // Look for visible declarations. 3288 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 3289 Result.setAllowHidden(Consumer.includeHiddenDecls()); 3290 VisibleDeclsRecord Visited; 3291 if (!IncludeGlobalScope) 3292 Visited.visitedContext(Context.getTranslationUnitDecl()); 3293 ShadowContextRAII Shadow(Visited); 3294 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited); 3295 } 3296 3297 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind, 3298 VisibleDeclConsumer &Consumer, 3299 bool IncludeGlobalScope) { 3300 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 3301 Result.setAllowHidden(Consumer.includeHiddenDecls()); 3302 VisibleDeclsRecord Visited; 3303 if (!IncludeGlobalScope) 3304 Visited.visitedContext(Context.getTranslationUnitDecl()); 3305 ShadowContextRAII Shadow(Visited); 3306 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true, 3307 /*InBaseClass=*/false, Consumer, Visited); 3308 } 3309 3310 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name. 3311 /// If GnuLabelLoc is a valid source location, then this is a definition 3312 /// of an __label__ label name, otherwise it is a normal label definition 3313 /// or use. 3314 LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc, 3315 SourceLocation GnuLabelLoc) { 3316 // Do a lookup to see if we have a label with this name already. 3317 NamedDecl *Res = nullptr; 3318 3319 if (GnuLabelLoc.isValid()) { 3320 // Local label definitions always shadow existing labels. 3321 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc); 3322 Scope *S = CurScope; 3323 PushOnScopeChains(Res, S, true); 3324 return cast<LabelDecl>(Res); 3325 } 3326 3327 // Not a GNU local label. 3328 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration); 3329 // If we found a label, check to see if it is in the same context as us. 3330 // When in a Block, we don't want to reuse a label in an enclosing function. 3331 if (Res && Res->getDeclContext() != CurContext) 3332 Res = nullptr; 3333 if (!Res) { 3334 // If not forward referenced or defined already, create the backing decl. 3335 Res = LabelDecl::Create(Context, CurContext, Loc, II); 3336 Scope *S = CurScope->getFnParent(); 3337 assert(S && "Not in a function?"); 3338 PushOnScopeChains(Res, S, true); 3339 } 3340 return cast<LabelDecl>(Res); 3341 } 3342 3343 //===----------------------------------------------------------------------===// 3344 // Typo correction 3345 //===----------------------------------------------------------------------===// 3346 3347 static bool isCandidateViable(CorrectionCandidateCallback &CCC, 3348 TypoCorrection &Candidate) { 3349 Candidate.setCallbackDistance(CCC.RankCandidate(Candidate)); 3350 return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance; 3351 } 3352 3353 static void LookupPotentialTypoResult(Sema &SemaRef, 3354 LookupResult &Res, 3355 IdentifierInfo *Name, 3356 Scope *S, CXXScopeSpec *SS, 3357 DeclContext *MemberContext, 3358 bool EnteringContext, 3359 bool isObjCIvarLookup, 3360 bool FindHidden); 3361 3362 /// \brief Check whether the declarations found for a typo correction are 3363 /// visible, and if none of them are, convert the correction to an 'import 3364 /// a module' correction. 3365 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) { 3366 if (TC.begin() == TC.end()) 3367 return; 3368 3369 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end(); 3370 3371 for (/**/; DI != DE; ++DI) 3372 if (!LookupResult::isVisible(SemaRef, *DI)) 3373 break; 3374 // Nothing to do if all decls are visible. 3375 if (DI == DE) 3376 return; 3377 3378 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI); 3379 bool AnyVisibleDecls = !NewDecls.empty(); 3380 3381 for (/**/; DI != DE; ++DI) { 3382 NamedDecl *VisibleDecl = *DI; 3383 if (!LookupResult::isVisible(SemaRef, *DI)) 3384 VisibleDecl = findAcceptableDecl(SemaRef, *DI); 3385 3386 if (VisibleDecl) { 3387 if (!AnyVisibleDecls) { 3388 // Found a visible decl, discard all hidden ones. 3389 AnyVisibleDecls = true; 3390 NewDecls.clear(); 3391 } 3392 NewDecls.push_back(VisibleDecl); 3393 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate()) 3394 NewDecls.push_back(*DI); 3395 } 3396 3397 if (NewDecls.empty()) 3398 TC = TypoCorrection(); 3399 else { 3400 TC.setCorrectionDecls(NewDecls); 3401 TC.setRequiresImport(!AnyVisibleDecls); 3402 } 3403 } 3404 3405 // Fill the supplied vector with the IdentifierInfo pointers for each piece of 3406 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::", 3407 // fill the vector with the IdentifierInfo pointers for "foo" and "bar"). 3408 static void getNestedNameSpecifierIdentifiers( 3409 NestedNameSpecifier *NNS, 3410 SmallVectorImpl<const IdentifierInfo*> &Identifiers) { 3411 if (NestedNameSpecifier *Prefix = NNS->getPrefix()) 3412 getNestedNameSpecifierIdentifiers(Prefix, Identifiers); 3413 else 3414 Identifiers.clear(); 3415 3416 const IdentifierInfo *II = nullptr; 3417 3418 switch (NNS->getKind()) { 3419 case NestedNameSpecifier::Identifier: 3420 II = NNS->getAsIdentifier(); 3421 break; 3422 3423 case NestedNameSpecifier::Namespace: 3424 if (NNS->getAsNamespace()->isAnonymousNamespace()) 3425 return; 3426 II = NNS->getAsNamespace()->getIdentifier(); 3427 break; 3428 3429 case NestedNameSpecifier::NamespaceAlias: 3430 II = NNS->getAsNamespaceAlias()->getIdentifier(); 3431 break; 3432 3433 case NestedNameSpecifier::TypeSpecWithTemplate: 3434 case NestedNameSpecifier::TypeSpec: 3435 II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier(); 3436 break; 3437 3438 case NestedNameSpecifier::Global: 3439 case NestedNameSpecifier::Super: 3440 return; 3441 } 3442 3443 if (II) 3444 Identifiers.push_back(II); 3445 } 3446 3447 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding, 3448 DeclContext *Ctx, bool InBaseClass) { 3449 // Don't consider hidden names for typo correction. 3450 if (Hiding) 3451 return; 3452 3453 // Only consider entities with identifiers for names, ignoring 3454 // special names (constructors, overloaded operators, selectors, 3455 // etc.). 3456 IdentifierInfo *Name = ND->getIdentifier(); 3457 if (!Name) 3458 return; 3459 3460 // Only consider visible declarations and declarations from modules with 3461 // names that exactly match. 3462 if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo && 3463 !findAcceptableDecl(SemaRef, ND)) 3464 return; 3465 3466 FoundName(Name->getName()); 3467 } 3468 3469 void TypoCorrectionConsumer::FoundName(StringRef Name) { 3470 // Compute the edit distance between the typo and the name of this 3471 // entity, and add the identifier to the list of results. 3472 addName(Name, nullptr); 3473 } 3474 3475 void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) { 3476 // Compute the edit distance between the typo and this keyword, 3477 // and add the keyword to the list of results. 3478 addName(Keyword, nullptr, nullptr, true); 3479 } 3480 3481 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND, 3482 NestedNameSpecifier *NNS, bool isKeyword) { 3483 // Use a simple length-based heuristic to determine the minimum possible 3484 // edit distance. If the minimum isn't good enough, bail out early. 3485 StringRef TypoStr = Typo->getName(); 3486 unsigned MinED = abs((int)Name.size() - (int)TypoStr.size()); 3487 if (MinED && TypoStr.size() / MinED < 3) 3488 return; 3489 3490 // Compute an upper bound on the allowable edit distance, so that the 3491 // edit-distance algorithm can short-circuit. 3492 unsigned UpperBound = (TypoStr.size() + 2) / 3 + 1; 3493 unsigned ED = TypoStr.edit_distance(Name, true, UpperBound); 3494 if (ED >= UpperBound) return; 3495 3496 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED); 3497 if (isKeyword) TC.makeKeyword(); 3498 TC.setCorrectionRange(nullptr, Result.getLookupNameInfo()); 3499 addCorrection(TC); 3500 } 3501 3502 static const unsigned MaxTypoDistanceResultSets = 5; 3503 3504 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) { 3505 StringRef TypoStr = Typo->getName(); 3506 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName(); 3507 3508 // For very short typos, ignore potential corrections that have a different 3509 // base identifier from the typo or which have a normalized edit distance 3510 // longer than the typo itself. 3511 if (TypoStr.size() < 3 && 3512 (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size())) 3513 return; 3514 3515 // If the correction is resolved but is not viable, ignore it. 3516 if (Correction.isResolved()) { 3517 checkCorrectionVisibility(SemaRef, Correction); 3518 if (!Correction || !isCandidateViable(*CorrectionValidator, Correction)) 3519 return; 3520 } 3521 3522 TypoResultList &CList = 3523 CorrectionResults[Correction.getEditDistance(false)][Name]; 3524 3525 if (!CList.empty() && !CList.back().isResolved()) 3526 CList.pop_back(); 3527 if (NamedDecl *NewND = Correction.getCorrectionDecl()) { 3528 std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts()); 3529 for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end(); 3530 RI != RIEnd; ++RI) { 3531 // If the Correction refers to a decl already in the result list, 3532 // replace the existing result if the string representation of Correction 3533 // comes before the current result alphabetically, then stop as there is 3534 // nothing more to be done to add Correction to the candidate set. 3535 if (RI->getCorrectionDecl() == NewND) { 3536 if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts())) 3537 *RI = Correction; 3538 return; 3539 } 3540 } 3541 } 3542 if (CList.empty() || Correction.isResolved()) 3543 CList.push_back(Correction); 3544 3545 while (CorrectionResults.size() > MaxTypoDistanceResultSets) 3546 CorrectionResults.erase(std::prev(CorrectionResults.end())); 3547 } 3548 3549 void TypoCorrectionConsumer::addNamespaces( 3550 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) { 3551 SearchNamespaces = true; 3552 3553 for (auto KNPair : KnownNamespaces) 3554 Namespaces.addNameSpecifier(KNPair.first); 3555 3556 bool SSIsTemplate = false; 3557 if (NestedNameSpecifier *NNS = 3558 (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) { 3559 if (const Type *T = NNS->getAsType()) 3560 SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization; 3561 } 3562 for (const auto *TI : SemaRef.getASTContext().types()) { 3563 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) { 3564 CD = CD->getCanonicalDecl(); 3565 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() && 3566 !CD->isUnion() && CD->getIdentifier() && 3567 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) && 3568 (CD->isBeingDefined() || CD->isCompleteDefinition())) 3569 Namespaces.addNameSpecifier(CD); 3570 } 3571 } 3572 } 3573 3574 const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() { 3575 if (++CurrentTCIndex < ValidatedCorrections.size()) 3576 return ValidatedCorrections[CurrentTCIndex]; 3577 3578 CurrentTCIndex = ValidatedCorrections.size(); 3579 while (!CorrectionResults.empty()) { 3580 auto DI = CorrectionResults.begin(); 3581 if (DI->second.empty()) { 3582 CorrectionResults.erase(DI); 3583 continue; 3584 } 3585 3586 auto RI = DI->second.begin(); 3587 if (RI->second.empty()) { 3588 DI->second.erase(RI); 3589 performQualifiedLookups(); 3590 continue; 3591 } 3592 3593 TypoCorrection TC = RI->second.pop_back_val(); 3594 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) { 3595 ValidatedCorrections.push_back(TC); 3596 return ValidatedCorrections[CurrentTCIndex]; 3597 } 3598 } 3599 return ValidatedCorrections[0]; // The empty correction. 3600 } 3601 3602 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) { 3603 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo(); 3604 DeclContext *TempMemberContext = MemberContext; 3605 CXXScopeSpec *TempSS = SS.get(); 3606 retry_lookup: 3607 LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext, 3608 EnteringContext, 3609 CorrectionValidator->IsObjCIvarLookup, 3610 Name == Typo && !Candidate.WillReplaceSpecifier()); 3611 switch (Result.getResultKind()) { 3612 case LookupResult::NotFound: 3613 case LookupResult::NotFoundInCurrentInstantiation: 3614 case LookupResult::FoundUnresolvedValue: 3615 if (TempSS) { 3616 // Immediately retry the lookup without the given CXXScopeSpec 3617 TempSS = nullptr; 3618 Candidate.WillReplaceSpecifier(true); 3619 goto retry_lookup; 3620 } 3621 if (TempMemberContext) { 3622 if (SS && !TempSS) 3623 TempSS = SS.get(); 3624 TempMemberContext = nullptr; 3625 goto retry_lookup; 3626 } 3627 if (SearchNamespaces) 3628 QualifiedResults.push_back(Candidate); 3629 break; 3630 3631 case LookupResult::Ambiguous: 3632 // We don't deal with ambiguities. 3633 break; 3634 3635 case LookupResult::Found: 3636 case LookupResult::FoundOverloaded: 3637 // Store all of the Decls for overloaded symbols 3638 for (auto *TRD : Result) 3639 Candidate.addCorrectionDecl(TRD); 3640 checkCorrectionVisibility(SemaRef, Candidate); 3641 if (!isCandidateViable(*CorrectionValidator, Candidate)) { 3642 if (SearchNamespaces) 3643 QualifiedResults.push_back(Candidate); 3644 break; 3645 } 3646 Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo()); 3647 return true; 3648 } 3649 return false; 3650 } 3651 3652 void TypoCorrectionConsumer::performQualifiedLookups() { 3653 unsigned TypoLen = Typo->getName().size(); 3654 for (auto QR : QualifiedResults) { 3655 for (auto NSI : Namespaces) { 3656 DeclContext *Ctx = NSI.DeclCtx; 3657 const Type *NSType = NSI.NameSpecifier->getAsType(); 3658 3659 // If the current NestedNameSpecifier refers to a class and the 3660 // current correction candidate is the name of that class, then skip 3661 // it as it is unlikely a qualified version of the class' constructor 3662 // is an appropriate correction. 3663 if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() : 0) { 3664 if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo()) 3665 continue; 3666 } 3667 3668 TypoCorrection TC(QR); 3669 TC.ClearCorrectionDecls(); 3670 TC.setCorrectionSpecifier(NSI.NameSpecifier); 3671 TC.setQualifierDistance(NSI.EditDistance); 3672 TC.setCallbackDistance(0); // Reset the callback distance 3673 3674 // If the current correction candidate and namespace combination are 3675 // too far away from the original typo based on the normalized edit 3676 // distance, then skip performing a qualified name lookup. 3677 unsigned TmpED = TC.getEditDistance(true); 3678 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED && 3679 TypoLen / TmpED < 3) 3680 continue; 3681 3682 Result.clear(); 3683 Result.setLookupName(QR.getCorrectionAsIdentifierInfo()); 3684 if (!SemaRef.LookupQualifiedName(Result, Ctx)) 3685 continue; 3686 3687 // Any corrections added below will be validated in subsequent 3688 // iterations of the main while() loop over the Consumer's contents. 3689 switch (Result.getResultKind()) { 3690 case LookupResult::Found: 3691 case LookupResult::FoundOverloaded: { 3692 if (SS && SS->isValid()) { 3693 std::string NewQualified = TC.getAsString(SemaRef.getLangOpts()); 3694 std::string OldQualified; 3695 llvm::raw_string_ostream OldOStream(OldQualified); 3696 SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy()); 3697 OldOStream << Typo->getName(); 3698 // If correction candidate would be an identical written qualified 3699 // identifer, then the existing CXXScopeSpec probably included a 3700 // typedef that didn't get accounted for properly. 3701 if (OldOStream.str() == NewQualified) 3702 break; 3703 } 3704 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end(); 3705 TRD != TRDEnd; ++TRD) { 3706 if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(), 3707 NSType ? NSType->getAsCXXRecordDecl() 3708 : nullptr, 3709 TRD.getPair()) == Sema::AR_accessible) 3710 TC.addCorrectionDecl(*TRD); 3711 } 3712 if (TC.isResolved()) { 3713 TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo()); 3714 addCorrection(TC); 3715 } 3716 break; 3717 } 3718 case LookupResult::NotFound: 3719 case LookupResult::NotFoundInCurrentInstantiation: 3720 case LookupResult::Ambiguous: 3721 case LookupResult::FoundUnresolvedValue: 3722 break; 3723 } 3724 } 3725 } 3726 QualifiedResults.clear(); 3727 } 3728 3729 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet( 3730 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec) 3731 : Context(Context), CurContextChain(buildContextChain(CurContext)) { 3732 if (NestedNameSpecifier *NNS = 3733 CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) { 3734 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier); 3735 NNS->print(SpecifierOStream, Context.getPrintingPolicy()); 3736 3737 getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers); 3738 } 3739 // Build the list of identifiers that would be used for an absolute 3740 // (from the global context) NestedNameSpecifier referring to the current 3741 // context. 3742 for (DeclContextList::reverse_iterator C = CurContextChain.rbegin(), 3743 CEnd = CurContextChain.rend(); 3744 C != CEnd; ++C) { 3745 if (NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(*C)) 3746 CurContextIdentifiers.push_back(ND->getIdentifier()); 3747 } 3748 3749 // Add the global context as a NestedNameSpecifier 3750 SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()), 3751 NestedNameSpecifier::GlobalSpecifier(Context), 1}; 3752 DistanceMap[1].push_back(SI); 3753 } 3754 3755 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain( 3756 DeclContext *Start) -> DeclContextList { 3757 assert(Start && "Building a context chain from a null context"); 3758 DeclContextList Chain; 3759 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr; 3760 DC = DC->getLookupParent()) { 3761 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC); 3762 if (!DC->isInlineNamespace() && !DC->isTransparentContext() && 3763 !(ND && ND->isAnonymousNamespace())) 3764 Chain.push_back(DC->getPrimaryContext()); 3765 } 3766 return Chain; 3767 } 3768 3769 unsigned 3770 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier( 3771 DeclContextList &DeclChain, NestedNameSpecifier *&NNS) { 3772 unsigned NumSpecifiers = 0; 3773 for (DeclContextList::reverse_iterator C = DeclChain.rbegin(), 3774 CEnd = DeclChain.rend(); 3775 C != CEnd; ++C) { 3776 if (NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(*C)) { 3777 NNS = NestedNameSpecifier::Create(Context, NNS, ND); 3778 ++NumSpecifiers; 3779 } else if (RecordDecl *RD = dyn_cast_or_null<RecordDecl>(*C)) { 3780 NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(), 3781 RD->getTypeForDecl()); 3782 ++NumSpecifiers; 3783 } 3784 } 3785 return NumSpecifiers; 3786 } 3787 3788 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier( 3789 DeclContext *Ctx) { 3790 NestedNameSpecifier *NNS = nullptr; 3791 unsigned NumSpecifiers = 0; 3792 DeclContextList NamespaceDeclChain(buildContextChain(Ctx)); 3793 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain); 3794 3795 // Eliminate common elements from the two DeclContext chains. 3796 for (DeclContextList::reverse_iterator C = CurContextChain.rbegin(), 3797 CEnd = CurContextChain.rend(); 3798 C != CEnd && !NamespaceDeclChain.empty() && 3799 NamespaceDeclChain.back() == *C; ++C) { 3800 NamespaceDeclChain.pop_back(); 3801 } 3802 3803 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain 3804 NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS); 3805 3806 // Add an explicit leading '::' specifier if needed. 3807 if (NamespaceDeclChain.empty()) { 3808 // Rebuild the NestedNameSpecifier as a globally-qualified specifier. 3809 NNS = NestedNameSpecifier::GlobalSpecifier(Context); 3810 NumSpecifiers = 3811 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS); 3812 } else if (NamedDecl *ND = 3813 dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) { 3814 IdentifierInfo *Name = ND->getIdentifier(); 3815 bool SameNameSpecifier = false; 3816 if (std::find(CurNameSpecifierIdentifiers.begin(), 3817 CurNameSpecifierIdentifiers.end(), 3818 Name) != CurNameSpecifierIdentifiers.end()) { 3819 std::string NewNameSpecifier; 3820 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier); 3821 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers; 3822 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers); 3823 NNS->print(SpecifierOStream, Context.getPrintingPolicy()); 3824 SpecifierOStream.flush(); 3825 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier; 3826 } 3827 if (SameNameSpecifier || 3828 std::find(CurContextIdentifiers.begin(), CurContextIdentifiers.end(), 3829 Name) != CurContextIdentifiers.end()) { 3830 // Rebuild the NestedNameSpecifier as a globally-qualified specifier. 3831 NNS = NestedNameSpecifier::GlobalSpecifier(Context); 3832 NumSpecifiers = 3833 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS); 3834 } 3835 } 3836 3837 // If the built NestedNameSpecifier would be replacing an existing 3838 // NestedNameSpecifier, use the number of component identifiers that 3839 // would need to be changed as the edit distance instead of the number 3840 // of components in the built NestedNameSpecifier. 3841 if (NNS && !CurNameSpecifierIdentifiers.empty()) { 3842 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers; 3843 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers); 3844 NumSpecifiers = llvm::ComputeEditDistance( 3845 llvm::makeArrayRef(CurNameSpecifierIdentifiers), 3846 llvm::makeArrayRef(NewNameSpecifierIdentifiers)); 3847 } 3848 3849 SpecifierInfo SI = {Ctx, NNS, NumSpecifiers}; 3850 DistanceMap[NumSpecifiers].push_back(SI); 3851 } 3852 3853 /// \brief Perform name lookup for a possible result for typo correction. 3854 static void LookupPotentialTypoResult(Sema &SemaRef, 3855 LookupResult &Res, 3856 IdentifierInfo *Name, 3857 Scope *S, CXXScopeSpec *SS, 3858 DeclContext *MemberContext, 3859 bool EnteringContext, 3860 bool isObjCIvarLookup, 3861 bool FindHidden) { 3862 Res.suppressDiagnostics(); 3863 Res.clear(); 3864 Res.setLookupName(Name); 3865 Res.setAllowHidden(FindHidden); 3866 if (MemberContext) { 3867 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) { 3868 if (isObjCIvarLookup) { 3869 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) { 3870 Res.addDecl(Ivar); 3871 Res.resolveKind(); 3872 return; 3873 } 3874 } 3875 3876 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(Name)) { 3877 Res.addDecl(Prop); 3878 Res.resolveKind(); 3879 return; 3880 } 3881 } 3882 3883 SemaRef.LookupQualifiedName(Res, MemberContext); 3884 return; 3885 } 3886 3887 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false, 3888 EnteringContext); 3889 3890 // Fake ivar lookup; this should really be part of 3891 // LookupParsedName. 3892 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) { 3893 if (Method->isInstanceMethod() && Method->getClassInterface() && 3894 (Res.empty() || 3895 (Res.isSingleResult() && 3896 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) { 3897 if (ObjCIvarDecl *IV 3898 = Method->getClassInterface()->lookupInstanceVariable(Name)) { 3899 Res.addDecl(IV); 3900 Res.resolveKind(); 3901 } 3902 } 3903 } 3904 } 3905 3906 /// \brief Add keywords to the consumer as possible typo corrections. 3907 static void AddKeywordsToConsumer(Sema &SemaRef, 3908 TypoCorrectionConsumer &Consumer, 3909 Scope *S, CorrectionCandidateCallback &CCC, 3910 bool AfterNestedNameSpecifier) { 3911 if (AfterNestedNameSpecifier) { 3912 // For 'X::', we know exactly which keywords can appear next. 3913 Consumer.addKeywordResult("template"); 3914 if (CCC.WantExpressionKeywords) 3915 Consumer.addKeywordResult("operator"); 3916 return; 3917 } 3918 3919 if (CCC.WantObjCSuper) 3920 Consumer.addKeywordResult("super"); 3921 3922 if (CCC.WantTypeSpecifiers) { 3923 // Add type-specifier keywords to the set of results. 3924 static const char *const CTypeSpecs[] = { 3925 "char", "const", "double", "enum", "float", "int", "long", "short", 3926 "signed", "struct", "union", "unsigned", "void", "volatile", 3927 "_Complex", "_Imaginary", 3928 // storage-specifiers as well 3929 "extern", "inline", "static", "typedef" 3930 }; 3931 3932 const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs); 3933 for (unsigned I = 0; I != NumCTypeSpecs; ++I) 3934 Consumer.addKeywordResult(CTypeSpecs[I]); 3935 3936 if (SemaRef.getLangOpts().C99) 3937 Consumer.addKeywordResult("restrict"); 3938 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) 3939 Consumer.addKeywordResult("bool"); 3940 else if (SemaRef.getLangOpts().C99) 3941 Consumer.addKeywordResult("_Bool"); 3942 3943 if (SemaRef.getLangOpts().CPlusPlus) { 3944 Consumer.addKeywordResult("class"); 3945 Consumer.addKeywordResult("typename"); 3946 Consumer.addKeywordResult("wchar_t"); 3947 3948 if (SemaRef.getLangOpts().CPlusPlus11) { 3949 Consumer.addKeywordResult("char16_t"); 3950 Consumer.addKeywordResult("char32_t"); 3951 Consumer.addKeywordResult("constexpr"); 3952 Consumer.addKeywordResult("decltype"); 3953 Consumer.addKeywordResult("thread_local"); 3954 } 3955 } 3956 3957 if (SemaRef.getLangOpts().GNUMode) 3958 Consumer.addKeywordResult("typeof"); 3959 } else if (CCC.WantFunctionLikeCasts) { 3960 static const char *const CastableTypeSpecs[] = { 3961 "char", "double", "float", "int", "long", "short", 3962 "signed", "unsigned", "void" 3963 }; 3964 for (auto *kw : CastableTypeSpecs) 3965 Consumer.addKeywordResult(kw); 3966 } 3967 3968 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) { 3969 Consumer.addKeywordResult("const_cast"); 3970 Consumer.addKeywordResult("dynamic_cast"); 3971 Consumer.addKeywordResult("reinterpret_cast"); 3972 Consumer.addKeywordResult("static_cast"); 3973 } 3974 3975 if (CCC.WantExpressionKeywords) { 3976 Consumer.addKeywordResult("sizeof"); 3977 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) { 3978 Consumer.addKeywordResult("false"); 3979 Consumer.addKeywordResult("true"); 3980 } 3981 3982 if (SemaRef.getLangOpts().CPlusPlus) { 3983 static const char *const CXXExprs[] = { 3984 "delete", "new", "operator", "throw", "typeid" 3985 }; 3986 const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs); 3987 for (unsigned I = 0; I != NumCXXExprs; ++I) 3988 Consumer.addKeywordResult(CXXExprs[I]); 3989 3990 if (isa<CXXMethodDecl>(SemaRef.CurContext) && 3991 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance()) 3992 Consumer.addKeywordResult("this"); 3993 3994 if (SemaRef.getLangOpts().CPlusPlus11) { 3995 Consumer.addKeywordResult("alignof"); 3996 Consumer.addKeywordResult("nullptr"); 3997 } 3998 } 3999 4000 if (SemaRef.getLangOpts().C11) { 4001 // FIXME: We should not suggest _Alignof if the alignof macro 4002 // is present. 4003 Consumer.addKeywordResult("_Alignof"); 4004 } 4005 } 4006 4007 if (CCC.WantRemainingKeywords) { 4008 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) { 4009 // Statements. 4010 static const char *const CStmts[] = { 4011 "do", "else", "for", "goto", "if", "return", "switch", "while" }; 4012 const unsigned NumCStmts = llvm::array_lengthof(CStmts); 4013 for (unsigned I = 0; I != NumCStmts; ++I) 4014 Consumer.addKeywordResult(CStmts[I]); 4015 4016 if (SemaRef.getLangOpts().CPlusPlus) { 4017 Consumer.addKeywordResult("catch"); 4018 Consumer.addKeywordResult("try"); 4019 } 4020 4021 if (S && S->getBreakParent()) 4022 Consumer.addKeywordResult("break"); 4023 4024 if (S && S->getContinueParent()) 4025 Consumer.addKeywordResult("continue"); 4026 4027 if (!SemaRef.getCurFunction()->SwitchStack.empty()) { 4028 Consumer.addKeywordResult("case"); 4029 Consumer.addKeywordResult("default"); 4030 } 4031 } else { 4032 if (SemaRef.getLangOpts().CPlusPlus) { 4033 Consumer.addKeywordResult("namespace"); 4034 Consumer.addKeywordResult("template"); 4035 } 4036 4037 if (S && S->isClassScope()) { 4038 Consumer.addKeywordResult("explicit"); 4039 Consumer.addKeywordResult("friend"); 4040 Consumer.addKeywordResult("mutable"); 4041 Consumer.addKeywordResult("private"); 4042 Consumer.addKeywordResult("protected"); 4043 Consumer.addKeywordResult("public"); 4044 Consumer.addKeywordResult("virtual"); 4045 } 4046 } 4047 4048 if (SemaRef.getLangOpts().CPlusPlus) { 4049 Consumer.addKeywordResult("using"); 4050 4051 if (SemaRef.getLangOpts().CPlusPlus11) 4052 Consumer.addKeywordResult("static_assert"); 4053 } 4054 } 4055 } 4056 4057 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer( 4058 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind, 4059 Scope *S, CXXScopeSpec *SS, 4060 std::unique_ptr<CorrectionCandidateCallback> CCC, 4061 DeclContext *MemberContext, bool EnteringContext, 4062 const ObjCObjectPointerType *OPT, bool ErrorRecovery) { 4063 4064 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking || 4065 DisableTypoCorrection) 4066 return nullptr; 4067 4068 // In Microsoft mode, don't perform typo correction in a template member 4069 // function dependent context because it interferes with the "lookup into 4070 // dependent bases of class templates" feature. 4071 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() && 4072 isa<CXXMethodDecl>(CurContext)) 4073 return nullptr; 4074 4075 // We only attempt to correct typos for identifiers. 4076 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 4077 if (!Typo) 4078 return nullptr; 4079 4080 // If the scope specifier itself was invalid, don't try to correct 4081 // typos. 4082 if (SS && SS->isInvalid()) 4083 return nullptr; 4084 4085 // Never try to correct typos during template deduction or 4086 // instantiation. 4087 if (!ActiveTemplateInstantiations.empty()) 4088 return nullptr; 4089 4090 // Don't try to correct 'super'. 4091 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier()) 4092 return nullptr; 4093 4094 // Abort if typo correction already failed for this specific typo. 4095 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo); 4096 if (locs != TypoCorrectionFailures.end() && 4097 locs->second.count(TypoName.getLoc())) 4098 return nullptr; 4099 4100 // Don't try to correct the identifier "vector" when in AltiVec mode. 4101 // TODO: Figure out why typo correction misbehaves in this case, fix it, and 4102 // remove this workaround. 4103 if (getLangOpts().AltiVec && Typo->isStr("vector")) 4104 return nullptr; 4105 4106 // Provide a stop gap for files that are just seriously broken. Trying 4107 // to correct all typos can turn into a HUGE performance penalty, causing 4108 // some files to take minutes to get rejected by the parser. 4109 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit; 4110 if (Limit && TyposCorrected >= Limit) 4111 return nullptr; 4112 ++TyposCorrected; 4113 4114 // If we're handling a missing symbol error, using modules, and the 4115 // special search all modules option is used, look for a missing import. 4116 if (ErrorRecovery && getLangOpts().Modules && 4117 getLangOpts().ModulesSearchAll) { 4118 // The following has the side effect of loading the missing module. 4119 getModuleLoader().lookupMissingImports(Typo->getName(), 4120 TypoName.getLocStart()); 4121 } 4122 4123 CorrectionCandidateCallback &CCCRef = *CCC; 4124 auto Consumer = llvm::make_unique<TypoCorrectionConsumer>( 4125 *this, TypoName, LookupKind, S, SS, std::move(CCC), MemberContext, 4126 EnteringContext); 4127 4128 // Perform name lookup to find visible, similarly-named entities. 4129 bool IsUnqualifiedLookup = false; 4130 DeclContext *QualifiedDC = MemberContext; 4131 if (MemberContext) { 4132 LookupVisibleDecls(MemberContext, LookupKind, *Consumer); 4133 4134 // Look in qualified interfaces. 4135 if (OPT) { 4136 for (auto *I : OPT->quals()) 4137 LookupVisibleDecls(I, LookupKind, *Consumer); 4138 } 4139 } else if (SS && SS->isSet()) { 4140 QualifiedDC = computeDeclContext(*SS, EnteringContext); 4141 if (!QualifiedDC) 4142 return nullptr; 4143 4144 LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer); 4145 } else { 4146 IsUnqualifiedLookup = true; 4147 } 4148 4149 // Determine whether we are going to search in the various namespaces for 4150 // corrections. 4151 bool SearchNamespaces 4152 = getLangOpts().CPlusPlus && 4153 (IsUnqualifiedLookup || (SS && SS->isSet())); 4154 4155 if (IsUnqualifiedLookup || SearchNamespaces) { 4156 // For unqualified lookup, look through all of the names that we have 4157 // seen in this translation unit. 4158 // FIXME: Re-add the ability to skip very unlikely potential corrections. 4159 for (const auto &I : Context.Idents) 4160 Consumer->FoundName(I.getKey()); 4161 4162 // Walk through identifiers in external identifier sources. 4163 // FIXME: Re-add the ability to skip very unlikely potential corrections. 4164 if (IdentifierInfoLookup *External 4165 = Context.Idents.getExternalIdentifierLookup()) { 4166 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers()); 4167 do { 4168 StringRef Name = Iter->Next(); 4169 if (Name.empty()) 4170 break; 4171 4172 Consumer->FoundName(Name); 4173 } while (true); 4174 } 4175 } 4176 4177 AddKeywordsToConsumer(*this, *Consumer, S, CCCRef, SS && SS->isNotEmpty()); 4178 4179 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going 4180 // to search those namespaces. 4181 if (SearchNamespaces) { 4182 // Load any externally-known namespaces. 4183 if (ExternalSource && !LoadedExternalKnownNamespaces) { 4184 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces; 4185 LoadedExternalKnownNamespaces = true; 4186 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces); 4187 for (auto *N : ExternalKnownNamespaces) 4188 KnownNamespaces[N] = true; 4189 } 4190 4191 Consumer->addNamespaces(KnownNamespaces); 4192 } 4193 4194 return Consumer; 4195 } 4196 4197 /// \brief Try to "correct" a typo in the source code by finding 4198 /// visible declarations whose names are similar to the name that was 4199 /// present in the source code. 4200 /// 4201 /// \param TypoName the \c DeclarationNameInfo structure that contains 4202 /// the name that was present in the source code along with its location. 4203 /// 4204 /// \param LookupKind the name-lookup criteria used to search for the name. 4205 /// 4206 /// \param S the scope in which name lookup occurs. 4207 /// 4208 /// \param SS the nested-name-specifier that precedes the name we're 4209 /// looking for, if present. 4210 /// 4211 /// \param CCC A CorrectionCandidateCallback object that provides further 4212 /// validation of typo correction candidates. It also provides flags for 4213 /// determining the set of keywords permitted. 4214 /// 4215 /// \param MemberContext if non-NULL, the context in which to look for 4216 /// a member access expression. 4217 /// 4218 /// \param EnteringContext whether we're entering the context described by 4219 /// the nested-name-specifier SS. 4220 /// 4221 /// \param OPT when non-NULL, the search for visible declarations will 4222 /// also walk the protocols in the qualified interfaces of \p OPT. 4223 /// 4224 /// \returns a \c TypoCorrection containing the corrected name if the typo 4225 /// along with information such as the \c NamedDecl where the corrected name 4226 /// was declared, and any additional \c NestedNameSpecifier needed to access 4227 /// it (C++ only). The \c TypoCorrection is empty if there is no correction. 4228 TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName, 4229 Sema::LookupNameKind LookupKind, 4230 Scope *S, CXXScopeSpec *SS, 4231 std::unique_ptr<CorrectionCandidateCallback> CCC, 4232 CorrectTypoKind Mode, 4233 DeclContext *MemberContext, 4234 bool EnteringContext, 4235 const ObjCObjectPointerType *OPT, 4236 bool RecordFailure) { 4237 assert(CCC && "CorrectTypo requires a CorrectionCandidateCallback"); 4238 4239 // Always let the ExternalSource have the first chance at correction, even 4240 // if we would otherwise have given up. 4241 if (ExternalSource) { 4242 if (TypoCorrection Correction = ExternalSource->CorrectTypo( 4243 TypoName, LookupKind, S, SS, *CCC, MemberContext, EnteringContext, OPT)) 4244 return Correction; 4245 } 4246 4247 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver; 4248 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for 4249 // some instances of CTC_Unknown, while WantRemainingKeywords is true 4250 // for CTC_Unknown but not for CTC_ObjCMessageReceiver. 4251 bool ObjCMessageReceiver = CCC->WantObjCSuper && !CCC->WantRemainingKeywords; 4252 4253 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 4254 auto Consumer = makeTypoCorrectionConsumer( 4255 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext, 4256 EnteringContext, OPT, Mode == CTK_ErrorRecovery); 4257 4258 if (!Consumer) 4259 return TypoCorrection(); 4260 4261 // If we haven't found anything, we're done. 4262 if (Consumer->empty()) 4263 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 4264 4265 // Make sure the best edit distance (prior to adding any namespace qualifiers) 4266 // is not more that about a third of the length of the typo's identifier. 4267 unsigned ED = Consumer->getBestEditDistance(true); 4268 unsigned TypoLen = Typo->getName().size(); 4269 if (ED > 0 && TypoLen / ED < 3) 4270 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 4271 4272 TypoCorrection BestTC = Consumer->getNextCorrection(); 4273 TypoCorrection SecondBestTC = Consumer->getNextCorrection(); 4274 if (!BestTC) 4275 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 4276 4277 ED = BestTC.getEditDistance(); 4278 4279 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) { 4280 // If this was an unqualified lookup and we believe the callback 4281 // object wouldn't have filtered out possible corrections, note 4282 // that no correction was found. 4283 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 4284 } 4285 4286 // If only a single name remains, return that result. 4287 if (!SecondBestTC || 4288 SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) { 4289 const TypoCorrection &Result = BestTC; 4290 4291 // Don't correct to a keyword that's the same as the typo; the keyword 4292 // wasn't actually in scope. 4293 if (ED == 0 && Result.isKeyword()) 4294 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 4295 4296 TypoCorrection TC = Result; 4297 TC.setCorrectionRange(SS, TypoName); 4298 checkCorrectionVisibility(*this, TC); 4299 return TC; 4300 } else if (SecondBestTC && ObjCMessageReceiver) { 4301 // Prefer 'super' when we're completing in a message-receiver 4302 // context. 4303 4304 if (BestTC.getCorrection().getAsString() != "super") { 4305 if (SecondBestTC.getCorrection().getAsString() == "super") 4306 BestTC = SecondBestTC; 4307 else if ((*Consumer)["super"].front().isKeyword()) 4308 BestTC = (*Consumer)["super"].front(); 4309 } 4310 // Don't correct to a keyword that's the same as the typo; the keyword 4311 // wasn't actually in scope. 4312 if (BestTC.getEditDistance() == 0 || 4313 BestTC.getCorrection().getAsString() != "super") 4314 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 4315 4316 BestTC.setCorrectionRange(SS, TypoName); 4317 return BestTC; 4318 } 4319 4320 // Record the failure's location if needed and return an empty correction. If 4321 // this was an unqualified lookup and we believe the callback object did not 4322 // filter out possible corrections, also cache the failure for the typo. 4323 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC); 4324 } 4325 4326 /// \brief Try to "correct" a typo in the source code by finding 4327 /// visible declarations whose names are similar to the name that was 4328 /// present in the source code. 4329 /// 4330 /// \param TypoName the \c DeclarationNameInfo structure that contains 4331 /// the name that was present in the source code along with its location. 4332 /// 4333 /// \param LookupKind the name-lookup criteria used to search for the name. 4334 /// 4335 /// \param S the scope in which name lookup occurs. 4336 /// 4337 /// \param SS the nested-name-specifier that precedes the name we're 4338 /// looking for, if present. 4339 /// 4340 /// \param CCC A CorrectionCandidateCallback object that provides further 4341 /// validation of typo correction candidates. It also provides flags for 4342 /// determining the set of keywords permitted. 4343 /// 4344 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print 4345 /// diagnostics when the actual typo correction is attempted. 4346 /// 4347 /// \param TRC A TypoRecoveryCallback functor that will be used to build an 4348 /// Expr from a typo correction candidate. 4349 /// 4350 /// \param MemberContext if non-NULL, the context in which to look for 4351 /// a member access expression. 4352 /// 4353 /// \param EnteringContext whether we're entering the context described by 4354 /// the nested-name-specifier SS. 4355 /// 4356 /// \param OPT when non-NULL, the search for visible declarations will 4357 /// also walk the protocols in the qualified interfaces of \p OPT. 4358 /// 4359 /// \returns a new \c TypoExpr that will later be replaced in the AST with an 4360 /// Expr representing the result of performing typo correction, or nullptr if 4361 /// typo correction is not possible. If nullptr is returned, no diagnostics will 4362 /// be emitted and it is the responsibility of the caller to emit any that are 4363 /// needed. 4364 TypoExpr *Sema::CorrectTypoDelayed( 4365 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind, 4366 Scope *S, CXXScopeSpec *SS, 4367 std::unique_ptr<CorrectionCandidateCallback> CCC, 4368 TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode, 4369 DeclContext *MemberContext, bool EnteringContext, 4370 const ObjCObjectPointerType *OPT) { 4371 assert(CCC && "CorrectTypoDelayed requires a CorrectionCandidateCallback"); 4372 4373 TypoCorrection Empty; 4374 auto Consumer = makeTypoCorrectionConsumer( 4375 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext, 4376 EnteringContext, OPT, Mode == CTK_ErrorRecovery); 4377 4378 if (!Consumer || Consumer->empty()) 4379 return nullptr; 4380 4381 // Make sure the best edit distance (prior to adding any namespace qualifiers) 4382 // is not more that about a third of the length of the typo's identifier. 4383 unsigned ED = Consumer->getBestEditDistance(true); 4384 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 4385 if (ED > 0 && Typo->getName().size() / ED < 3) 4386 return nullptr; 4387 4388 ExprEvalContexts.back().NumTypos++; 4389 return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC)); 4390 } 4391 4392 void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) { 4393 if (!CDecl) return; 4394 4395 if (isKeyword()) 4396 CorrectionDecls.clear(); 4397 4398 CorrectionDecls.push_back(CDecl->getUnderlyingDecl()); 4399 4400 if (!CorrectionName) 4401 CorrectionName = CDecl->getDeclName(); 4402 } 4403 4404 std::string TypoCorrection::getAsString(const LangOptions &LO) const { 4405 if (CorrectionNameSpec) { 4406 std::string tmpBuffer; 4407 llvm::raw_string_ostream PrefixOStream(tmpBuffer); 4408 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO)); 4409 PrefixOStream << CorrectionName; 4410 return PrefixOStream.str(); 4411 } 4412 4413 return CorrectionName.getAsString(); 4414 } 4415 4416 bool CorrectionCandidateCallback::ValidateCandidate( 4417 const TypoCorrection &candidate) { 4418 if (!candidate.isResolved()) 4419 return true; 4420 4421 if (candidate.isKeyword()) 4422 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts || 4423 WantRemainingKeywords || WantObjCSuper; 4424 4425 bool HasNonType = false; 4426 bool HasStaticMethod = false; 4427 bool HasNonStaticMethod = false; 4428 for (Decl *D : candidate) { 4429 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D)) 4430 D = FTD->getTemplatedDecl(); 4431 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 4432 if (Method->isStatic()) 4433 HasStaticMethod = true; 4434 else 4435 HasNonStaticMethod = true; 4436 } 4437 if (!isa<TypeDecl>(D)) 4438 HasNonType = true; 4439 } 4440 4441 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod && 4442 !candidate.getCorrectionSpecifier()) 4443 return false; 4444 4445 return WantTypeSpecifiers || HasNonType; 4446 } 4447 4448 FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs, 4449 bool HasExplicitTemplateArgs, 4450 MemberExpr *ME) 4451 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs), 4452 CurContext(SemaRef.CurContext), MemberFn(ME) { 4453 WantTypeSpecifiers = false; 4454 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && NumArgs == 1; 4455 WantRemainingKeywords = false; 4456 } 4457 4458 bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) { 4459 if (!candidate.getCorrectionDecl()) 4460 return candidate.isKeyword(); 4461 4462 for (auto *C : candidate) { 4463 FunctionDecl *FD = nullptr; 4464 NamedDecl *ND = C->getUnderlyingDecl(); 4465 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 4466 FD = FTD->getTemplatedDecl(); 4467 if (!HasExplicitTemplateArgs && !FD) { 4468 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) { 4469 // If the Decl is neither a function nor a template function, 4470 // determine if it is a pointer or reference to a function. If so, 4471 // check against the number of arguments expected for the pointee. 4472 QualType ValType = cast<ValueDecl>(ND)->getType(); 4473 if (ValType->isAnyPointerType() || ValType->isReferenceType()) 4474 ValType = ValType->getPointeeType(); 4475 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>()) 4476 if (FPT->getNumParams() == NumArgs) 4477 return true; 4478 } 4479 } 4480 4481 // Skip the current candidate if it is not a FunctionDecl or does not accept 4482 // the current number of arguments. 4483 if (!FD || !(FD->getNumParams() >= NumArgs && 4484 FD->getMinRequiredArguments() <= NumArgs)) 4485 continue; 4486 4487 // If the current candidate is a non-static C++ method, skip the candidate 4488 // unless the method being corrected--or the current DeclContext, if the 4489 // function being corrected is not a method--is a method in the same class 4490 // or a descendent class of the candidate's parent class. 4491 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) { 4492 if (MemberFn || !MD->isStatic()) { 4493 CXXMethodDecl *CurMD = 4494 MemberFn 4495 ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl()) 4496 : dyn_cast_or_null<CXXMethodDecl>(CurContext); 4497 CXXRecordDecl *CurRD = 4498 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr; 4499 CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl(); 4500 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD))) 4501 continue; 4502 } 4503 } 4504 return true; 4505 } 4506 return false; 4507 } 4508 4509 void Sema::diagnoseTypo(const TypoCorrection &Correction, 4510 const PartialDiagnostic &TypoDiag, 4511 bool ErrorRecovery) { 4512 diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl), 4513 ErrorRecovery); 4514 } 4515 4516 /// Find which declaration we should import to provide the definition of 4517 /// the given declaration. 4518 static const NamedDecl *getDefinitionToImport(const NamedDecl *D) { 4519 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 4520 return VD->getDefinition(); 4521 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) 4522 return FD->isDefined(FD) ? FD : nullptr; 4523 if (const TagDecl *TD = dyn_cast<TagDecl>(D)) 4524 return TD->getDefinition(); 4525 if (const ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D)) 4526 return ID->getDefinition(); 4527 if (const ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D)) 4528 return PD->getDefinition(); 4529 if (const TemplateDecl *TD = dyn_cast<TemplateDecl>(D)) 4530 return getDefinitionToImport(TD->getTemplatedDecl()); 4531 return nullptr; 4532 } 4533 4534 /// \brief Diagnose a successfully-corrected typo. Separated from the correction 4535 /// itself to allow external validation of the result, etc. 4536 /// 4537 /// \param Correction The result of performing typo correction. 4538 /// \param TypoDiag The diagnostic to produce. This will have the corrected 4539 /// string added to it (and usually also a fixit). 4540 /// \param PrevNote A note to use when indicating the location of the entity to 4541 /// which we are correcting. Will have the correction string added to it. 4542 /// \param ErrorRecovery If \c true (the default), the caller is going to 4543 /// recover from the typo as if the corrected string had been typed. 4544 /// In this case, \c PDiag must be an error, and we will attach a fixit 4545 /// to it. 4546 void Sema::diagnoseTypo(const TypoCorrection &Correction, 4547 const PartialDiagnostic &TypoDiag, 4548 const PartialDiagnostic &PrevNote, 4549 bool ErrorRecovery) { 4550 std::string CorrectedStr = Correction.getAsString(getLangOpts()); 4551 std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts()); 4552 FixItHint FixTypo = FixItHint::CreateReplacement( 4553 Correction.getCorrectionRange(), CorrectedStr); 4554 4555 // Maybe we're just missing a module import. 4556 if (Correction.requiresImport()) { 4557 NamedDecl *Decl = Correction.getCorrectionDecl(); 4558 assert(Decl && "import required but no declaration to import"); 4559 4560 // Suggest importing a module providing the definition of this entity, if 4561 // possible. 4562 const NamedDecl *Def = getDefinitionToImport(Decl); 4563 if (!Def) 4564 Def = Decl; 4565 Module *Owner = Def->getOwningModule(); 4566 assert(Owner && "definition of hidden declaration is not in a module"); 4567 4568 Diag(Correction.getCorrectionRange().getBegin(), 4569 diag::err_module_private_declaration) 4570 << Def << Owner->getFullModuleName(); 4571 Diag(Def->getLocation(), diag::note_previous_declaration); 4572 4573 // Recover by implicitly importing this module. 4574 if (ErrorRecovery) 4575 createImplicitModuleImportForErrorRecovery( 4576 Correction.getCorrectionRange().getBegin(), Owner); 4577 return; 4578 } 4579 4580 Diag(Correction.getCorrectionRange().getBegin(), TypoDiag) 4581 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint()); 4582 4583 NamedDecl *ChosenDecl = 4584 Correction.isKeyword() ? nullptr : Correction.getCorrectionDecl(); 4585 if (PrevNote.getDiagID() && ChosenDecl) 4586 Diag(ChosenDecl->getLocation(), PrevNote) 4587 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo); 4588 } 4589 4590 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC, 4591 TypoDiagnosticGenerator TDG, 4592 TypoRecoveryCallback TRC) { 4593 assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer"); 4594 auto TE = new (Context) TypoExpr(Context.DependentTy); 4595 auto &State = DelayedTypos[TE]; 4596 State.Consumer = std::move(TCC); 4597 State.DiagHandler = std::move(TDG); 4598 State.RecoveryHandler = std::move(TRC); 4599 return TE; 4600 } 4601 4602 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const { 4603 auto Entry = DelayedTypos.find(TE); 4604 assert(Entry != DelayedTypos.end() && 4605 "Failed to get the state for a TypoExpr!"); 4606 return Entry->second; 4607 } 4608 4609 void Sema::clearDelayedTypo(TypoExpr *TE) { 4610 DelayedTypos.erase(TE); 4611 } 4612