SemaLookup.cpp revision 296417
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 15#include "clang/Sema/Lookup.h" 16#include "clang/AST/ASTContext.h" 17#include "clang/AST/ASTMutationListener.h" 18#include "clang/AST/CXXInheritance.h" 19#include "clang/AST/Decl.h" 20#include "clang/AST/DeclCXX.h" 21#include "clang/AST/DeclLookups.h" 22#include "clang/AST/DeclObjC.h" 23#include "clang/AST/DeclTemplate.h" 24#include "clang/AST/Expr.h" 25#include "clang/AST/ExprCXX.h" 26#include "clang/Basic/Builtins.h" 27#include "clang/Basic/LangOptions.h" 28#include "clang/Lex/HeaderSearch.h" 29#include "clang/Lex/ModuleLoader.h" 30#include "clang/Lex/Preprocessor.h" 31#include "clang/Sema/DeclSpec.h" 32#include "clang/Sema/ExternalSemaSource.h" 33#include "clang/Sema/Overload.h" 34#include "clang/Sema/Scope.h" 35#include "clang/Sema/ScopeInfo.h" 36#include "clang/Sema/Sema.h" 37#include "clang/Sema/SemaInternal.h" 38#include "clang/Sema/TemplateDeduction.h" 39#include "clang/Sema/TypoCorrection.h" 40#include "llvm/ADT/STLExtras.h" 41#include "llvm/ADT/SetVector.h" 42#include "llvm/ADT/SmallPtrSet.h" 43#include "llvm/ADT/StringMap.h" 44#include "llvm/ADT/TinyPtrVector.h" 45#include "llvm/ADT/edit_distance.h" 46#include "llvm/Support/ErrorHandling.h" 47#include <algorithm> 48#include <iterator> 49#include <limits> 50#include <list> 51#include <map> 52#include <set> 53#include <utility> 54#include <vector> 55 56using namespace clang; 57using namespace sema; 58 59namespace { 60 class UnqualUsingEntry { 61 const DeclContext *Nominated; 62 const DeclContext *CommonAncestor; 63 64 public: 65 UnqualUsingEntry(const DeclContext *Nominated, 66 const DeclContext *CommonAncestor) 67 : Nominated(Nominated), CommonAncestor(CommonAncestor) { 68 } 69 70 const DeclContext *getCommonAncestor() const { 71 return CommonAncestor; 72 } 73 74 const DeclContext *getNominatedNamespace() const { 75 return Nominated; 76 } 77 78 // Sort by the pointer value of the common ancestor. 79 struct Comparator { 80 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) { 81 return L.getCommonAncestor() < R.getCommonAncestor(); 82 } 83 84 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) { 85 return E.getCommonAncestor() < DC; 86 } 87 88 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) { 89 return DC < E.getCommonAncestor(); 90 } 91 }; 92 }; 93 94 /// A collection of using directives, as used by C++ unqualified 95 /// lookup. 96 class UnqualUsingDirectiveSet { 97 typedef SmallVector<UnqualUsingEntry, 8> ListTy; 98 99 ListTy list; 100 llvm::SmallPtrSet<DeclContext*, 8> visited; 101 102 public: 103 UnqualUsingDirectiveSet() {} 104 105 void visitScopeChain(Scope *S, Scope *InnermostFileScope) { 106 // C++ [namespace.udir]p1: 107 // During unqualified name lookup, the names appear as if they 108 // were declared in the nearest enclosing namespace which contains 109 // both the using-directive and the nominated namespace. 110 DeclContext *InnermostFileDC = InnermostFileScope->getEntity(); 111 assert(InnermostFileDC && InnermostFileDC->isFileContext()); 112 113 for (; S; S = S->getParent()) { 114 // C++ [namespace.udir]p1: 115 // A using-directive shall not appear in class scope, but may 116 // appear in namespace scope or in block scope. 117 DeclContext *Ctx = S->getEntity(); 118 if (Ctx && Ctx->isFileContext()) { 119 visit(Ctx, Ctx); 120 } else if (!Ctx || Ctx->isFunctionOrMethod()) { 121 for (auto *I : S->using_directives()) 122 visit(I, InnermostFileDC); 123 } 124 } 125 } 126 127 // Visits a context and collect all of its using directives 128 // recursively. Treats all using directives as if they were 129 // declared in the context. 130 // 131 // A given context is only every visited once, so it is important 132 // that contexts be visited from the inside out in order to get 133 // the effective DCs right. 134 void visit(DeclContext *DC, DeclContext *EffectiveDC) { 135 if (!visited.insert(DC).second) 136 return; 137 138 addUsingDirectives(DC, EffectiveDC); 139 } 140 141 // Visits a using directive and collects all of its using 142 // directives recursively. Treats all using directives as if they 143 // were declared in the effective DC. 144 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 145 DeclContext *NS = UD->getNominatedNamespace(); 146 if (!visited.insert(NS).second) 147 return; 148 149 addUsingDirective(UD, EffectiveDC); 150 addUsingDirectives(NS, EffectiveDC); 151 } 152 153 // Adds all the using directives in a context (and those nominated 154 // by its using directives, transitively) as if they appeared in 155 // the given effective context. 156 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) { 157 SmallVector<DeclContext*, 4> queue; 158 while (true) { 159 for (auto UD : DC->using_directives()) { 160 DeclContext *NS = UD->getNominatedNamespace(); 161 if (visited.insert(NS).second) { 162 addUsingDirective(UD, EffectiveDC); 163 queue.push_back(NS); 164 } 165 } 166 167 if (queue.empty()) 168 return; 169 170 DC = queue.pop_back_val(); 171 } 172 } 173 174 // Add a using directive as if it had been declared in the given 175 // context. This helps implement C++ [namespace.udir]p3: 176 // The using-directive is transitive: if a scope contains a 177 // using-directive that nominates a second namespace that itself 178 // contains using-directives, the effect is as if the 179 // using-directives from the second namespace also appeared in 180 // the first. 181 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 182 // Find the common ancestor between the effective context and 183 // the nominated namespace. 184 DeclContext *Common = UD->getNominatedNamespace(); 185 while (!Common->Encloses(EffectiveDC)) 186 Common = Common->getParent(); 187 Common = Common->getPrimaryContext(); 188 189 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common)); 190 } 191 192 void done() { 193 std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator()); 194 } 195 196 typedef ListTy::const_iterator const_iterator; 197 198 const_iterator begin() const { return list.begin(); } 199 const_iterator end() const { return list.end(); } 200 201 llvm::iterator_range<const_iterator> 202 getNamespacesFor(DeclContext *DC) const { 203 return llvm::make_range(std::equal_range(begin(), end(), 204 DC->getPrimaryContext(), 205 UnqualUsingEntry::Comparator())); 206 } 207 }; 208} // end anonymous namespace 209 210// Retrieve the set of identifier namespaces that correspond to a 211// specific kind of name lookup. 212static inline unsigned getIDNS(Sema::LookupNameKind NameKind, 213 bool CPlusPlus, 214 bool Redeclaration) { 215 unsigned IDNS = 0; 216 switch (NameKind) { 217 case Sema::LookupObjCImplicitSelfParam: 218 case Sema::LookupOrdinaryName: 219 case Sema::LookupRedeclarationWithLinkage: 220 case Sema::LookupLocalFriendName: 221 IDNS = Decl::IDNS_Ordinary; 222 if (CPlusPlus) { 223 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace; 224 if (Redeclaration) 225 IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend; 226 } 227 if (Redeclaration) 228 IDNS |= Decl::IDNS_LocalExtern; 229 break; 230 231 case Sema::LookupOperatorName: 232 // Operator lookup is its own crazy thing; it is not the same 233 // as (e.g.) looking up an operator name for redeclaration. 234 assert(!Redeclaration && "cannot do redeclaration operator lookup"); 235 IDNS = Decl::IDNS_NonMemberOperator; 236 break; 237 238 case Sema::LookupTagName: 239 if (CPlusPlus) { 240 IDNS = Decl::IDNS_Type; 241 242 // When looking for a redeclaration of a tag name, we add: 243 // 1) TagFriend to find undeclared friend decls 244 // 2) Namespace because they can't "overload" with tag decls. 245 // 3) Tag because it includes class templates, which can't 246 // "overload" with tag decls. 247 if (Redeclaration) 248 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace; 249 } else { 250 IDNS = Decl::IDNS_Tag; 251 } 252 break; 253 254 case Sema::LookupLabel: 255 IDNS = Decl::IDNS_Label; 256 break; 257 258 case Sema::LookupMemberName: 259 IDNS = Decl::IDNS_Member; 260 if (CPlusPlus) 261 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary; 262 break; 263 264 case Sema::LookupNestedNameSpecifierName: 265 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace; 266 break; 267 268 case Sema::LookupNamespaceName: 269 IDNS = Decl::IDNS_Namespace; 270 break; 271 272 case Sema::LookupUsingDeclName: 273 assert(Redeclaration && "should only be used for redecl lookup"); 274 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member | 275 Decl::IDNS_Using | Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend | 276 Decl::IDNS_LocalExtern; 277 break; 278 279 case Sema::LookupObjCProtocolName: 280 IDNS = Decl::IDNS_ObjCProtocol; 281 break; 282 283 case Sema::LookupAnyName: 284 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member 285 | Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol 286 | Decl::IDNS_Type; 287 break; 288 } 289 return IDNS; 290} 291 292void LookupResult::configure() { 293 IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus, 294 isForRedeclaration()); 295 296 // If we're looking for one of the allocation or deallocation 297 // operators, make sure that the implicitly-declared new and delete 298 // operators can be found. 299 switch (NameInfo.getName().getCXXOverloadedOperator()) { 300 case OO_New: 301 case OO_Delete: 302 case OO_Array_New: 303 case OO_Array_Delete: 304 getSema().DeclareGlobalNewDelete(); 305 break; 306 307 default: 308 break; 309 } 310 311 // Compiler builtins are always visible, regardless of where they end 312 // up being declared. 313 if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) { 314 if (unsigned BuiltinID = Id->getBuiltinID()) { 315 if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 316 AllowHidden = true; 317 } 318 } 319} 320 321bool LookupResult::sanity() const { 322 // This function is never called by NDEBUG builds. 323 assert(ResultKind != NotFound || Decls.size() == 0); 324 assert(ResultKind != Found || Decls.size() == 1); 325 assert(ResultKind != FoundOverloaded || Decls.size() > 1 || 326 (Decls.size() == 1 && 327 isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl()))); 328 assert(ResultKind != FoundUnresolvedValue || sanityCheckUnresolved()); 329 assert(ResultKind != Ambiguous || Decls.size() > 1 || 330 (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects || 331 Ambiguity == AmbiguousBaseSubobjectTypes))); 332 assert((Paths != nullptr) == (ResultKind == Ambiguous && 333 (Ambiguity == AmbiguousBaseSubobjectTypes || 334 Ambiguity == AmbiguousBaseSubobjects))); 335 return true; 336} 337 338// Necessary because CXXBasePaths is not complete in Sema.h 339void LookupResult::deletePaths(CXXBasePaths *Paths) { 340 delete Paths; 341} 342 343/// Get a representative context for a declaration such that two declarations 344/// will have the same context if they were found within the same scope. 345static DeclContext *getContextForScopeMatching(Decl *D) { 346 // For function-local declarations, use that function as the context. This 347 // doesn't account for scopes within the function; the caller must deal with 348 // those. 349 DeclContext *DC = D->getLexicalDeclContext(); 350 if (DC->isFunctionOrMethod()) 351 return DC; 352 353 // Otherwise, look at the semantic context of the declaration. The 354 // declaration must have been found there. 355 return D->getDeclContext()->getRedeclContext(); 356} 357 358/// \brief Determine whether \p D is a better lookup result than \p Existing, 359/// given that they declare the same entity. 360static bool isPreferredLookupResult(Sema &S, Sema::LookupNameKind Kind, 361 NamedDecl *D, NamedDecl *Existing) { 362 // When looking up redeclarations of a using declaration, prefer a using 363 // shadow declaration over any other declaration of the same entity. 364 if (Kind == Sema::LookupUsingDeclName && isa<UsingShadowDecl>(D) && 365 !isa<UsingShadowDecl>(Existing)) 366 return true; 367 368 auto *DUnderlying = D->getUnderlyingDecl(); 369 auto *EUnderlying = Existing->getUnderlyingDecl(); 370 371 // If they have different underlying declarations, prefer a typedef over the 372 // original type (this happens when two type declarations denote the same 373 // type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef 374 // might carry additional semantic information, such as an alignment override. 375 // However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag 376 // declaration over a typedef. 377 if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) { 378 assert(isa<TypeDecl>(DUnderlying) && isa<TypeDecl>(EUnderlying)); 379 bool HaveTag = isa<TagDecl>(EUnderlying); 380 bool WantTag = Kind == Sema::LookupTagName; 381 return HaveTag != WantTag; 382 } 383 384 // Pick the function with more default arguments. 385 // FIXME: In the presence of ambiguous default arguments, we should keep both, 386 // so we can diagnose the ambiguity if the default argument is needed. 387 // See C++ [over.match.best]p3. 388 if (auto *DFD = dyn_cast<FunctionDecl>(DUnderlying)) { 389 auto *EFD = cast<FunctionDecl>(EUnderlying); 390 unsigned DMin = DFD->getMinRequiredArguments(); 391 unsigned EMin = EFD->getMinRequiredArguments(); 392 // If D has more default arguments, it is preferred. 393 if (DMin != EMin) 394 return DMin < EMin; 395 // FIXME: When we track visibility for default function arguments, check 396 // that we pick the declaration with more visible default arguments. 397 } 398 399 // Pick the template with more default template arguments. 400 if (auto *DTD = dyn_cast<TemplateDecl>(DUnderlying)) { 401 auto *ETD = cast<TemplateDecl>(EUnderlying); 402 unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments(); 403 unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments(); 404 // If D has more default arguments, it is preferred. Note that default 405 // arguments (and their visibility) is monotonically increasing across the 406 // redeclaration chain, so this is a quick proxy for "is more recent". 407 if (DMin != EMin) 408 return DMin < EMin; 409 // If D has more *visible* default arguments, it is preferred. Note, an 410 // earlier default argument being visible does not imply that a later 411 // default argument is visible, so we can't just check the first one. 412 for (unsigned I = DMin, N = DTD->getTemplateParameters()->size(); 413 I != N; ++I) { 414 if (!S.hasVisibleDefaultArgument( 415 ETD->getTemplateParameters()->getParam(I)) && 416 S.hasVisibleDefaultArgument( 417 DTD->getTemplateParameters()->getParam(I))) 418 return true; 419 } 420 } 421 422 // For most kinds of declaration, it doesn't really matter which one we pick. 423 if (!isa<FunctionDecl>(DUnderlying) && !isa<VarDecl>(DUnderlying)) { 424 // If the existing declaration is hidden, prefer the new one. Otherwise, 425 // keep what we've got. 426 return !S.isVisible(Existing); 427 } 428 429 // Pick the newer declaration; it might have a more precise type. 430 for (Decl *Prev = DUnderlying->getPreviousDecl(); Prev; 431 Prev = Prev->getPreviousDecl()) 432 if (Prev == EUnderlying) 433 return true; 434 return false; 435 436 // If the existing declaration is hidden, prefer the new one. Otherwise, 437 // keep what we've got. 438 return !S.isVisible(Existing); 439} 440 441/// Determine whether \p D can hide a tag declaration. 442static bool canHideTag(NamedDecl *D) { 443 // C++ [basic.scope.declarative]p4: 444 // Given a set of declarations in a single declarative region [...] 445 // exactly one declaration shall declare a class name or enumeration name 446 // that is not a typedef name and the other declarations shall all refer to 447 // the same variable or enumerator, or all refer to functions and function 448 // templates; in this case the class name or enumeration name is hidden. 449 // C++ [basic.scope.hiding]p2: 450 // A class name or enumeration name can be hidden by the name of a 451 // variable, data member, function, or enumerator declared in the same 452 // scope. 453 D = D->getUnderlyingDecl(); 454 return isa<VarDecl>(D) || isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D) || 455 isa<FunctionTemplateDecl>(D) || isa<FieldDecl>(D); 456} 457 458/// Resolves the result kind of this lookup. 459void LookupResult::resolveKind() { 460 unsigned N = Decls.size(); 461 462 // Fast case: no possible ambiguity. 463 if (N == 0) { 464 assert(ResultKind == NotFound || 465 ResultKind == NotFoundInCurrentInstantiation); 466 return; 467 } 468 469 // If there's a single decl, we need to examine it to decide what 470 // kind of lookup this is. 471 if (N == 1) { 472 NamedDecl *D = (*Decls.begin())->getUnderlyingDecl(); 473 if (isa<FunctionTemplateDecl>(D)) 474 ResultKind = FoundOverloaded; 475 else if (isa<UnresolvedUsingValueDecl>(D)) 476 ResultKind = FoundUnresolvedValue; 477 return; 478 } 479 480 // Don't do any extra resolution if we've already resolved as ambiguous. 481 if (ResultKind == Ambiguous) return; 482 483 llvm::SmallDenseMap<NamedDecl*, unsigned, 16> Unique; 484 llvm::SmallDenseMap<QualType, unsigned, 16> UniqueTypes; 485 486 bool Ambiguous = false; 487 bool HasTag = false, HasFunction = false; 488 bool HasFunctionTemplate = false, HasUnresolved = false; 489 NamedDecl *HasNonFunction = nullptr; 490 491 llvm::SmallVector<NamedDecl*, 4> EquivalentNonFunctions; 492 493 unsigned UniqueTagIndex = 0; 494 495 unsigned I = 0; 496 while (I < N) { 497 NamedDecl *D = Decls[I]->getUnderlyingDecl(); 498 D = cast<NamedDecl>(D->getCanonicalDecl()); 499 500 // Ignore an invalid declaration unless it's the only one left. 501 if (D->isInvalidDecl() && !(I == 0 && N == 1)) { 502 Decls[I] = Decls[--N]; 503 continue; 504 } 505 506 llvm::Optional<unsigned> ExistingI; 507 508 // Redeclarations of types via typedef can occur both within a scope 509 // and, through using declarations and directives, across scopes. There is 510 // no ambiguity if they all refer to the same type, so unique based on the 511 // canonical type. 512 if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) { 513 QualType T = getSema().Context.getTypeDeclType(TD); 514 auto UniqueResult = UniqueTypes.insert( 515 std::make_pair(getSema().Context.getCanonicalType(T), I)); 516 if (!UniqueResult.second) { 517 // The type is not unique. 518 ExistingI = UniqueResult.first->second; 519 } 520 } 521 522 // For non-type declarations, check for a prior lookup result naming this 523 // canonical declaration. 524 if (!ExistingI) { 525 auto UniqueResult = Unique.insert(std::make_pair(D, I)); 526 if (!UniqueResult.second) { 527 // We've seen this entity before. 528 ExistingI = UniqueResult.first->second; 529 } 530 } 531 532 if (ExistingI) { 533 // This is not a unique lookup result. Pick one of the results and 534 // discard the other. 535 if (isPreferredLookupResult(getSema(), getLookupKind(), Decls[I], 536 Decls[*ExistingI])) 537 Decls[*ExistingI] = Decls[I]; 538 Decls[I] = Decls[--N]; 539 continue; 540 } 541 542 // Otherwise, do some decl type analysis and then continue. 543 544 if (isa<UnresolvedUsingValueDecl>(D)) { 545 HasUnresolved = true; 546 } else if (isa<TagDecl>(D)) { 547 if (HasTag) 548 Ambiguous = true; 549 UniqueTagIndex = I; 550 HasTag = true; 551 } else if (isa<FunctionTemplateDecl>(D)) { 552 HasFunction = true; 553 HasFunctionTemplate = true; 554 } else if (isa<FunctionDecl>(D)) { 555 HasFunction = true; 556 } else { 557 if (HasNonFunction) { 558 // If we're about to create an ambiguity between two declarations that 559 // are equivalent, but one is an internal linkage declaration from one 560 // module and the other is an internal linkage declaration from another 561 // module, just skip it. 562 if (getSema().isEquivalentInternalLinkageDeclaration(HasNonFunction, 563 D)) { 564 EquivalentNonFunctions.push_back(D); 565 Decls[I] = Decls[--N]; 566 continue; 567 } 568 569 Ambiguous = true; 570 } 571 HasNonFunction = D; 572 } 573 I++; 574 } 575 576 // C++ [basic.scope.hiding]p2: 577 // A class name or enumeration name can be hidden by the name of 578 // an object, function, or enumerator declared in the same 579 // scope. If a class or enumeration name and an object, function, 580 // or enumerator are declared in the same scope (in any order) 581 // with the same name, the class or enumeration name is hidden 582 // wherever the object, function, or enumerator name is visible. 583 // But it's still an error if there are distinct tag types found, 584 // even if they're not visible. (ref?) 585 if (N > 1 && HideTags && HasTag && !Ambiguous && 586 (HasFunction || HasNonFunction || HasUnresolved)) { 587 NamedDecl *OtherDecl = Decls[UniqueTagIndex ? 0 : N - 1]; 588 if (isa<TagDecl>(Decls[UniqueTagIndex]->getUnderlyingDecl()) && 589 getContextForScopeMatching(Decls[UniqueTagIndex])->Equals( 590 getContextForScopeMatching(OtherDecl)) && 591 canHideTag(OtherDecl)) 592 Decls[UniqueTagIndex] = Decls[--N]; 593 else 594 Ambiguous = true; 595 } 596 597 // FIXME: This diagnostic should really be delayed until we're done with 598 // the lookup result, in case the ambiguity is resolved by the caller. 599 if (!EquivalentNonFunctions.empty() && !Ambiguous) 600 getSema().diagnoseEquivalentInternalLinkageDeclarations( 601 getNameLoc(), HasNonFunction, EquivalentNonFunctions); 602 603 Decls.set_size(N); 604 605 if (HasNonFunction && (HasFunction || HasUnresolved)) 606 Ambiguous = true; 607 608 if (Ambiguous) 609 setAmbiguous(LookupResult::AmbiguousReference); 610 else if (HasUnresolved) 611 ResultKind = LookupResult::FoundUnresolvedValue; 612 else if (N > 1 || HasFunctionTemplate) 613 ResultKind = LookupResult::FoundOverloaded; 614 else 615 ResultKind = LookupResult::Found; 616} 617 618void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) { 619 CXXBasePaths::const_paths_iterator I, E; 620 for (I = P.begin(), E = P.end(); I != E; ++I) 621 for (DeclContext::lookup_iterator DI = I->Decls.begin(), 622 DE = I->Decls.end(); DI != DE; ++DI) 623 addDecl(*DI); 624} 625 626void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) { 627 Paths = new CXXBasePaths; 628 Paths->swap(P); 629 addDeclsFromBasePaths(*Paths); 630 resolveKind(); 631 setAmbiguous(AmbiguousBaseSubobjects); 632} 633 634void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) { 635 Paths = new CXXBasePaths; 636 Paths->swap(P); 637 addDeclsFromBasePaths(*Paths); 638 resolveKind(); 639 setAmbiguous(AmbiguousBaseSubobjectTypes); 640} 641 642void LookupResult::print(raw_ostream &Out) { 643 Out << Decls.size() << " result(s)"; 644 if (isAmbiguous()) Out << ", ambiguous"; 645 if (Paths) Out << ", base paths present"; 646 647 for (iterator I = begin(), E = end(); I != E; ++I) { 648 Out << "\n"; 649 (*I)->print(Out, 2); 650 } 651} 652 653LLVM_DUMP_METHOD void LookupResult::dump() { 654 llvm::errs() << "lookup results for " << getLookupName().getAsString() 655 << ":\n"; 656 for (NamedDecl *D : *this) 657 D->dump(); 658} 659 660/// \brief Lookup a builtin function, when name lookup would otherwise 661/// fail. 662static bool LookupBuiltin(Sema &S, LookupResult &R) { 663 Sema::LookupNameKind NameKind = R.getLookupKind(); 664 665 // If we didn't find a use of this identifier, and if the identifier 666 // corresponds to a compiler builtin, create the decl object for the builtin 667 // now, injecting it into translation unit scope, and return it. 668 if (NameKind == Sema::LookupOrdinaryName || 669 NameKind == Sema::LookupRedeclarationWithLinkage) { 670 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo(); 671 if (II) { 672 if (S.getLangOpts().CPlusPlus11 && S.getLangOpts().GNUMode && 673 II == S.getFloat128Identifier()) { 674 // libstdc++4.7's type_traits expects type __float128 to exist, so 675 // insert a dummy type to make that header build in gnu++11 mode. 676 R.addDecl(S.getASTContext().getFloat128StubType()); 677 return true; 678 } 679 if (S.getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName && 680 II == S.getASTContext().getMakeIntegerSeqName()) { 681 R.addDecl(S.getASTContext().getMakeIntegerSeqDecl()); 682 return true; 683 } 684 685 // If this is a builtin on this (or all) targets, create the decl. 686 if (unsigned BuiltinID = II->getBuiltinID()) { 687 // In C++, we don't have any predefined library functions like 688 // 'malloc'. Instead, we'll just error. 689 if (S.getLangOpts().CPlusPlus && 690 S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 691 return false; 692 693 if (NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II, 694 BuiltinID, S.TUScope, 695 R.isForRedeclaration(), 696 R.getNameLoc())) { 697 R.addDecl(D); 698 return true; 699 } 700 } 701 } 702 } 703 704 return false; 705} 706 707/// \brief Determine whether we can declare a special member function within 708/// the class at this point. 709static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) { 710 // We need to have a definition for the class. 711 if (!Class->getDefinition() || Class->isDependentContext()) 712 return false; 713 714 // We can't be in the middle of defining the class. 715 return !Class->isBeingDefined(); 716} 717 718void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) { 719 if (!CanDeclareSpecialMemberFunction(Class)) 720 return; 721 722 // If the default constructor has not yet been declared, do so now. 723 if (Class->needsImplicitDefaultConstructor()) 724 DeclareImplicitDefaultConstructor(Class); 725 726 // If the copy constructor has not yet been declared, do so now. 727 if (Class->needsImplicitCopyConstructor()) 728 DeclareImplicitCopyConstructor(Class); 729 730 // If the copy assignment operator has not yet been declared, do so now. 731 if (Class->needsImplicitCopyAssignment()) 732 DeclareImplicitCopyAssignment(Class); 733 734 if (getLangOpts().CPlusPlus11) { 735 // If the move constructor has not yet been declared, do so now. 736 if (Class->needsImplicitMoveConstructor()) 737 DeclareImplicitMoveConstructor(Class); // might not actually do it 738 739 // If the move assignment operator has not yet been declared, do so now. 740 if (Class->needsImplicitMoveAssignment()) 741 DeclareImplicitMoveAssignment(Class); // might not actually do it 742 } 743 744 // If the destructor has not yet been declared, do so now. 745 if (Class->needsImplicitDestructor()) 746 DeclareImplicitDestructor(Class); 747} 748 749/// \brief Determine whether this is the name of an implicitly-declared 750/// special member function. 751static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) { 752 switch (Name.getNameKind()) { 753 case DeclarationName::CXXConstructorName: 754 case DeclarationName::CXXDestructorName: 755 return true; 756 757 case DeclarationName::CXXOperatorName: 758 return Name.getCXXOverloadedOperator() == OO_Equal; 759 760 default: 761 break; 762 } 763 764 return false; 765} 766 767/// \brief If there are any implicit member functions with the given name 768/// that need to be declared in the given declaration context, do so. 769static void DeclareImplicitMemberFunctionsWithName(Sema &S, 770 DeclarationName Name, 771 const DeclContext *DC) { 772 if (!DC) 773 return; 774 775 switch (Name.getNameKind()) { 776 case DeclarationName::CXXConstructorName: 777 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) 778 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) { 779 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record); 780 if (Record->needsImplicitDefaultConstructor()) 781 S.DeclareImplicitDefaultConstructor(Class); 782 if (Record->needsImplicitCopyConstructor()) 783 S.DeclareImplicitCopyConstructor(Class); 784 if (S.getLangOpts().CPlusPlus11 && 785 Record->needsImplicitMoveConstructor()) 786 S.DeclareImplicitMoveConstructor(Class); 787 } 788 break; 789 790 case DeclarationName::CXXDestructorName: 791 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) 792 if (Record->getDefinition() && Record->needsImplicitDestructor() && 793 CanDeclareSpecialMemberFunction(Record)) 794 S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record)); 795 break; 796 797 case DeclarationName::CXXOperatorName: 798 if (Name.getCXXOverloadedOperator() != OO_Equal) 799 break; 800 801 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) { 802 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) { 803 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record); 804 if (Record->needsImplicitCopyAssignment()) 805 S.DeclareImplicitCopyAssignment(Class); 806 if (S.getLangOpts().CPlusPlus11 && 807 Record->needsImplicitMoveAssignment()) 808 S.DeclareImplicitMoveAssignment(Class); 809 } 810 } 811 break; 812 813 default: 814 break; 815 } 816} 817 818// Adds all qualifying matches for a name within a decl context to the 819// given lookup result. Returns true if any matches were found. 820static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) { 821 bool Found = false; 822 823 // Lazily declare C++ special member functions. 824 if (S.getLangOpts().CPlusPlus) 825 DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), DC); 826 827 // Perform lookup into this declaration context. 828 DeclContext::lookup_result DR = DC->lookup(R.getLookupName()); 829 for (DeclContext::lookup_iterator I = DR.begin(), E = DR.end(); I != E; 830 ++I) { 831 NamedDecl *D = *I; 832 if ((D = R.getAcceptableDecl(D))) { 833 R.addDecl(D); 834 Found = true; 835 } 836 } 837 838 if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R)) 839 return true; 840 841 if (R.getLookupName().getNameKind() 842 != DeclarationName::CXXConversionFunctionName || 843 R.getLookupName().getCXXNameType()->isDependentType() || 844 !isa<CXXRecordDecl>(DC)) 845 return Found; 846 847 // C++ [temp.mem]p6: 848 // A specialization of a conversion function template is not found by 849 // name lookup. Instead, any conversion function templates visible in the 850 // context of the use are considered. [...] 851 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC); 852 if (!Record->isCompleteDefinition()) 853 return Found; 854 855 for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(), 856 UEnd = Record->conversion_end(); U != UEnd; ++U) { 857 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U); 858 if (!ConvTemplate) 859 continue; 860 861 // When we're performing lookup for the purposes of redeclaration, just 862 // add the conversion function template. When we deduce template 863 // arguments for specializations, we'll end up unifying the return 864 // type of the new declaration with the type of the function template. 865 if (R.isForRedeclaration()) { 866 R.addDecl(ConvTemplate); 867 Found = true; 868 continue; 869 } 870 871 // C++ [temp.mem]p6: 872 // [...] For each such operator, if argument deduction succeeds 873 // (14.9.2.3), the resulting specialization is used as if found by 874 // name lookup. 875 // 876 // When referencing a conversion function for any purpose other than 877 // a redeclaration (such that we'll be building an expression with the 878 // result), perform template argument deduction and place the 879 // specialization into the result set. We do this to avoid forcing all 880 // callers to perform special deduction for conversion functions. 881 TemplateDeductionInfo Info(R.getNameLoc()); 882 FunctionDecl *Specialization = nullptr; 883 884 const FunctionProtoType *ConvProto 885 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>(); 886 assert(ConvProto && "Nonsensical conversion function template type"); 887 888 // Compute the type of the function that we would expect the conversion 889 // function to have, if it were to match the name given. 890 // FIXME: Calling convention! 891 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo(); 892 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C); 893 EPI.ExceptionSpec = EST_None; 894 QualType ExpectedType 895 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(), 896 None, EPI); 897 898 // Perform template argument deduction against the type that we would 899 // expect the function to have. 900 if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType, 901 Specialization, Info) 902 == Sema::TDK_Success) { 903 R.addDecl(Specialization); 904 Found = true; 905 } 906 } 907 908 return Found; 909} 910 911// Performs C++ unqualified lookup into the given file context. 912static bool 913CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context, 914 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) { 915 916 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!"); 917 918 // Perform direct name lookup into the LookupCtx. 919 bool Found = LookupDirect(S, R, NS); 920 921 // Perform direct name lookup into the namespaces nominated by the 922 // using directives whose common ancestor is this namespace. 923 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS)) 924 if (LookupDirect(S, R, UUE.getNominatedNamespace())) 925 Found = true; 926 927 R.resolveKind(); 928 929 return Found; 930} 931 932static bool isNamespaceOrTranslationUnitScope(Scope *S) { 933 if (DeclContext *Ctx = S->getEntity()) 934 return Ctx->isFileContext(); 935 return false; 936} 937 938// Find the next outer declaration context from this scope. This 939// routine actually returns the semantic outer context, which may 940// differ from the lexical context (encoded directly in the Scope 941// stack) when we are parsing a member of a class template. In this 942// case, the second element of the pair will be true, to indicate that 943// name lookup should continue searching in this semantic context when 944// it leaves the current template parameter scope. 945static std::pair<DeclContext *, bool> findOuterContext(Scope *S) { 946 DeclContext *DC = S->getEntity(); 947 DeclContext *Lexical = nullptr; 948 for (Scope *OuterS = S->getParent(); OuterS; 949 OuterS = OuterS->getParent()) { 950 if (OuterS->getEntity()) { 951 Lexical = OuterS->getEntity(); 952 break; 953 } 954 } 955 956 // C++ [temp.local]p8: 957 // In the definition of a member of a class template that appears 958 // outside of the namespace containing the class template 959 // definition, the name of a template-parameter hides the name of 960 // a member of this namespace. 961 // 962 // Example: 963 // 964 // namespace N { 965 // class C { }; 966 // 967 // template<class T> class B { 968 // void f(T); 969 // }; 970 // } 971 // 972 // template<class C> void N::B<C>::f(C) { 973 // C b; // C is the template parameter, not N::C 974 // } 975 // 976 // In this example, the lexical context we return is the 977 // TranslationUnit, while the semantic context is the namespace N. 978 if (!Lexical || !DC || !S->getParent() || 979 !S->getParent()->isTemplateParamScope()) 980 return std::make_pair(Lexical, false); 981 982 // Find the outermost template parameter scope. 983 // For the example, this is the scope for the template parameters of 984 // template<class C>. 985 Scope *OutermostTemplateScope = S->getParent(); 986 while (OutermostTemplateScope->getParent() && 987 OutermostTemplateScope->getParent()->isTemplateParamScope()) 988 OutermostTemplateScope = OutermostTemplateScope->getParent(); 989 990 // Find the namespace context in which the original scope occurs. In 991 // the example, this is namespace N. 992 DeclContext *Semantic = DC; 993 while (!Semantic->isFileContext()) 994 Semantic = Semantic->getParent(); 995 996 // Find the declaration context just outside of the template 997 // parameter scope. This is the context in which the template is 998 // being lexically declaration (a namespace context). In the 999 // example, this is the global scope. 1000 if (Lexical->isFileContext() && !Lexical->Equals(Semantic) && 1001 Lexical->Encloses(Semantic)) 1002 return std::make_pair(Semantic, true); 1003 1004 return std::make_pair(Lexical, false); 1005} 1006 1007namespace { 1008/// An RAII object to specify that we want to find block scope extern 1009/// declarations. 1010struct FindLocalExternScope { 1011 FindLocalExternScope(LookupResult &R) 1012 : R(R), OldFindLocalExtern(R.getIdentifierNamespace() & 1013 Decl::IDNS_LocalExtern) { 1014 R.setFindLocalExtern(R.getIdentifierNamespace() & Decl::IDNS_Ordinary); 1015 } 1016 void restore() { 1017 R.setFindLocalExtern(OldFindLocalExtern); 1018 } 1019 ~FindLocalExternScope() { 1020 restore(); 1021 } 1022 LookupResult &R; 1023 bool OldFindLocalExtern; 1024}; 1025} // end anonymous namespace 1026 1027bool Sema::CppLookupName(LookupResult &R, Scope *S) { 1028 assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup"); 1029 1030 DeclarationName Name = R.getLookupName(); 1031 Sema::LookupNameKind NameKind = R.getLookupKind(); 1032 1033 // If this is the name of an implicitly-declared special member function, 1034 // go through the scope stack to implicitly declare 1035 if (isImplicitlyDeclaredMemberFunctionName(Name)) { 1036 for (Scope *PreS = S; PreS; PreS = PreS->getParent()) 1037 if (DeclContext *DC = PreS->getEntity()) 1038 DeclareImplicitMemberFunctionsWithName(*this, Name, DC); 1039 } 1040 1041 // Implicitly declare member functions with the name we're looking for, if in 1042 // fact we are in a scope where it matters. 1043 1044 Scope *Initial = S; 1045 IdentifierResolver::iterator 1046 I = IdResolver.begin(Name), 1047 IEnd = IdResolver.end(); 1048 1049 // First we lookup local scope. 1050 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir] 1051 // ...During unqualified name lookup (3.4.1), the names appear as if 1052 // they were declared in the nearest enclosing namespace which contains 1053 // both the using-directive and the nominated namespace. 1054 // [Note: in this context, "contains" means "contains directly or 1055 // indirectly". 1056 // 1057 // For example: 1058 // namespace A { int i; } 1059 // void foo() { 1060 // int i; 1061 // { 1062 // using namespace A; 1063 // ++i; // finds local 'i', A::i appears at global scope 1064 // } 1065 // } 1066 // 1067 UnqualUsingDirectiveSet UDirs; 1068 bool VisitedUsingDirectives = false; 1069 bool LeftStartingScope = false; 1070 DeclContext *OutsideOfTemplateParamDC = nullptr; 1071 1072 // When performing a scope lookup, we want to find local extern decls. 1073 FindLocalExternScope FindLocals(R); 1074 1075 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) { 1076 DeclContext *Ctx = S->getEntity(); 1077 1078 // Check whether the IdResolver has anything in this scope. 1079 bool Found = false; 1080 for (; I != IEnd && S->isDeclScope(*I); ++I) { 1081 if (NamedDecl *ND = R.getAcceptableDecl(*I)) { 1082 if (NameKind == LookupRedeclarationWithLinkage) { 1083 // Determine whether this (or a previous) declaration is 1084 // out-of-scope. 1085 if (!LeftStartingScope && !Initial->isDeclScope(*I)) 1086 LeftStartingScope = true; 1087 1088 // If we found something outside of our starting scope that 1089 // does not have linkage, skip it. If it's a template parameter, 1090 // we still find it, so we can diagnose the invalid redeclaration. 1091 if (LeftStartingScope && !((*I)->hasLinkage()) && 1092 !(*I)->isTemplateParameter()) { 1093 R.setShadowed(); 1094 continue; 1095 } 1096 } 1097 1098 Found = true; 1099 R.addDecl(ND); 1100 } 1101 } 1102 if (Found) { 1103 R.resolveKind(); 1104 if (S->isClassScope()) 1105 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx)) 1106 R.setNamingClass(Record); 1107 return true; 1108 } 1109 1110 if (NameKind == LookupLocalFriendName && !S->isClassScope()) { 1111 // C++11 [class.friend]p11: 1112 // If a friend declaration appears in a local class and the name 1113 // specified is an unqualified name, a prior declaration is 1114 // looked up without considering scopes that are outside the 1115 // innermost enclosing non-class scope. 1116 return false; 1117 } 1118 1119 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC && 1120 S->getParent() && !S->getParent()->isTemplateParamScope()) { 1121 // We've just searched the last template parameter scope and 1122 // found nothing, so look into the contexts between the 1123 // lexical and semantic declaration contexts returned by 1124 // findOuterContext(). This implements the name lookup behavior 1125 // of C++ [temp.local]p8. 1126 Ctx = OutsideOfTemplateParamDC; 1127 OutsideOfTemplateParamDC = nullptr; 1128 } 1129 1130 if (Ctx) { 1131 DeclContext *OuterCtx; 1132 bool SearchAfterTemplateScope; 1133 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S); 1134 if (SearchAfterTemplateScope) 1135 OutsideOfTemplateParamDC = OuterCtx; 1136 1137 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 1138 // We do not directly look into transparent contexts, since 1139 // those entities will be found in the nearest enclosing 1140 // non-transparent context. 1141 if (Ctx->isTransparentContext()) 1142 continue; 1143 1144 // We do not look directly into function or method contexts, 1145 // since all of the local variables and parameters of the 1146 // function/method are present within the Scope. 1147 if (Ctx->isFunctionOrMethod()) { 1148 // If we have an Objective-C instance method, look for ivars 1149 // in the corresponding interface. 1150 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 1151 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo()) 1152 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) { 1153 ObjCInterfaceDecl *ClassDeclared; 1154 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable( 1155 Name.getAsIdentifierInfo(), 1156 ClassDeclared)) { 1157 if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) { 1158 R.addDecl(ND); 1159 R.resolveKind(); 1160 return true; 1161 } 1162 } 1163 } 1164 } 1165 1166 continue; 1167 } 1168 1169 // If this is a file context, we need to perform unqualified name 1170 // lookup considering using directives. 1171 if (Ctx->isFileContext()) { 1172 // If we haven't handled using directives yet, do so now. 1173 if (!VisitedUsingDirectives) { 1174 // Add using directives from this context up to the top level. 1175 for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) { 1176 if (UCtx->isTransparentContext()) 1177 continue; 1178 1179 UDirs.visit(UCtx, UCtx); 1180 } 1181 1182 // Find the innermost file scope, so we can add using directives 1183 // from local scopes. 1184 Scope *InnermostFileScope = S; 1185 while (InnermostFileScope && 1186 !isNamespaceOrTranslationUnitScope(InnermostFileScope)) 1187 InnermostFileScope = InnermostFileScope->getParent(); 1188 UDirs.visitScopeChain(Initial, InnermostFileScope); 1189 1190 UDirs.done(); 1191 1192 VisitedUsingDirectives = true; 1193 } 1194 1195 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) { 1196 R.resolveKind(); 1197 return true; 1198 } 1199 1200 continue; 1201 } 1202 1203 // Perform qualified name lookup into this context. 1204 // FIXME: In some cases, we know that every name that could be found by 1205 // this qualified name lookup will also be on the identifier chain. For 1206 // example, inside a class without any base classes, we never need to 1207 // perform qualified lookup because all of the members are on top of the 1208 // identifier chain. 1209 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true)) 1210 return true; 1211 } 1212 } 1213 } 1214 1215 // Stop if we ran out of scopes. 1216 // FIXME: This really, really shouldn't be happening. 1217 if (!S) return false; 1218 1219 // If we are looking for members, no need to look into global/namespace scope. 1220 if (NameKind == LookupMemberName) 1221 return false; 1222 1223 // Collect UsingDirectiveDecls in all scopes, and recursively all 1224 // nominated namespaces by those using-directives. 1225 // 1226 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we 1227 // don't build it for each lookup! 1228 if (!VisitedUsingDirectives) { 1229 UDirs.visitScopeChain(Initial, S); 1230 UDirs.done(); 1231 } 1232 1233 // If we're not performing redeclaration lookup, do not look for local 1234 // extern declarations outside of a function scope. 1235 if (!R.isForRedeclaration()) 1236 FindLocals.restore(); 1237 1238 // Lookup namespace scope, and global scope. 1239 // Unqualified name lookup in C++ requires looking into scopes 1240 // that aren't strictly lexical, and therefore we walk through the 1241 // context as well as walking through the scopes. 1242 for (; S; S = S->getParent()) { 1243 // Check whether the IdResolver has anything in this scope. 1244 bool Found = false; 1245 for (; I != IEnd && S->isDeclScope(*I); ++I) { 1246 if (NamedDecl *ND = R.getAcceptableDecl(*I)) { 1247 // We found something. Look for anything else in our scope 1248 // with this same name and in an acceptable identifier 1249 // namespace, so that we can construct an overload set if we 1250 // need to. 1251 Found = true; 1252 R.addDecl(ND); 1253 } 1254 } 1255 1256 if (Found && S->isTemplateParamScope()) { 1257 R.resolveKind(); 1258 return true; 1259 } 1260 1261 DeclContext *Ctx = S->getEntity(); 1262 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC && 1263 S->getParent() && !S->getParent()->isTemplateParamScope()) { 1264 // We've just searched the last template parameter scope and 1265 // found nothing, so look into the contexts between the 1266 // lexical and semantic declaration contexts returned by 1267 // findOuterContext(). This implements the name lookup behavior 1268 // of C++ [temp.local]p8. 1269 Ctx = OutsideOfTemplateParamDC; 1270 OutsideOfTemplateParamDC = nullptr; 1271 } 1272 1273 if (Ctx) { 1274 DeclContext *OuterCtx; 1275 bool SearchAfterTemplateScope; 1276 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S); 1277 if (SearchAfterTemplateScope) 1278 OutsideOfTemplateParamDC = OuterCtx; 1279 1280 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 1281 // We do not directly look into transparent contexts, since 1282 // those entities will be found in the nearest enclosing 1283 // non-transparent context. 1284 if (Ctx->isTransparentContext()) 1285 continue; 1286 1287 // If we have a context, and it's not a context stashed in the 1288 // template parameter scope for an out-of-line definition, also 1289 // look into that context. 1290 if (!(Found && S && S->isTemplateParamScope())) { 1291 assert(Ctx->isFileContext() && 1292 "We should have been looking only at file context here already."); 1293 1294 // Look into context considering using-directives. 1295 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) 1296 Found = true; 1297 } 1298 1299 if (Found) { 1300 R.resolveKind(); 1301 return true; 1302 } 1303 1304 if (R.isForRedeclaration() && !Ctx->isTransparentContext()) 1305 return false; 1306 } 1307 } 1308 1309 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext()) 1310 return false; 1311 } 1312 1313 return !R.empty(); 1314} 1315 1316/// \brief Find the declaration that a class temploid member specialization was 1317/// instantiated from, or the member itself if it is an explicit specialization. 1318static Decl *getInstantiatedFrom(Decl *D, MemberSpecializationInfo *MSInfo) { 1319 return MSInfo->isExplicitSpecialization() ? D : MSInfo->getInstantiatedFrom(); 1320} 1321 1322Module *Sema::getOwningModule(Decl *Entity) { 1323 // If it's imported, grab its owning module. 1324 Module *M = Entity->getImportedOwningModule(); 1325 if (M || !isa<NamedDecl>(Entity) || !cast<NamedDecl>(Entity)->isHidden()) 1326 return M; 1327 assert(!Entity->isFromASTFile() && 1328 "hidden entity from AST file has no owning module"); 1329 1330 if (!getLangOpts().ModulesLocalVisibility) { 1331 // If we're not tracking visibility locally, the only way a declaration 1332 // can be hidden and local is if it's hidden because it's parent is (for 1333 // instance, maybe this is a lazily-declared special member of an imported 1334 // class). 1335 auto *Parent = cast<NamedDecl>(Entity->getDeclContext()); 1336 assert(Parent->isHidden() && "unexpectedly hidden decl"); 1337 return getOwningModule(Parent); 1338 } 1339 1340 // It's local and hidden; grab or compute its owning module. 1341 M = Entity->getLocalOwningModule(); 1342 if (M) 1343 return M; 1344 1345 if (auto *Containing = 1346 PP.getModuleContainingLocation(Entity->getLocation())) { 1347 M = Containing; 1348 } else if (Entity->isInvalidDecl() || Entity->getLocation().isInvalid()) { 1349 // Don't bother tracking visibility for invalid declarations with broken 1350 // locations. 1351 cast<NamedDecl>(Entity)->setHidden(false); 1352 } else { 1353 // We need to assign a module to an entity that exists outside of any 1354 // module, so that we can hide it from modules that we textually enter. 1355 // Invent a fake module for all such entities. 1356 if (!CachedFakeTopLevelModule) { 1357 CachedFakeTopLevelModule = 1358 PP.getHeaderSearchInfo().getModuleMap().findOrCreateModule( 1359 "<top-level>", nullptr, false, false).first; 1360 1361 auto &SrcMgr = PP.getSourceManager(); 1362 SourceLocation StartLoc = 1363 SrcMgr.getLocForStartOfFile(SrcMgr.getMainFileID()); 1364 auto &TopLevel = 1365 VisibleModulesStack.empty() ? VisibleModules : VisibleModulesStack[0]; 1366 TopLevel.setVisible(CachedFakeTopLevelModule, StartLoc); 1367 } 1368 1369 M = CachedFakeTopLevelModule; 1370 } 1371 1372 if (M) 1373 Entity->setLocalOwningModule(M); 1374 return M; 1375} 1376 1377void Sema::makeMergedDefinitionVisible(NamedDecl *ND, SourceLocation Loc) { 1378 if (auto *M = PP.getModuleContainingLocation(Loc)) 1379 Context.mergeDefinitionIntoModule(ND, M); 1380 else 1381 // We're not building a module; just make the definition visible. 1382 ND->setHidden(false); 1383 1384 // If ND is a template declaration, make the template parameters 1385 // visible too. They're not (necessarily) within a mergeable DeclContext. 1386 if (auto *TD = dyn_cast<TemplateDecl>(ND)) 1387 for (auto *Param : *TD->getTemplateParameters()) 1388 makeMergedDefinitionVisible(Param, Loc); 1389} 1390 1391/// \brief Find the module in which the given declaration was defined. 1392static Module *getDefiningModule(Sema &S, Decl *Entity) { 1393 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) { 1394 // If this function was instantiated from a template, the defining module is 1395 // the module containing the pattern. 1396 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern()) 1397 Entity = Pattern; 1398 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) { 1399 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern()) 1400 Entity = Pattern; 1401 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) { 1402 if (MemberSpecializationInfo *MSInfo = ED->getMemberSpecializationInfo()) 1403 Entity = getInstantiatedFrom(ED, MSInfo); 1404 } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) { 1405 // FIXME: Map from variable template specializations back to the template. 1406 if (MemberSpecializationInfo *MSInfo = VD->getMemberSpecializationInfo()) 1407 Entity = getInstantiatedFrom(VD, MSInfo); 1408 } 1409 1410 // Walk up to the containing context. That might also have been instantiated 1411 // from a template. 1412 DeclContext *Context = Entity->getDeclContext(); 1413 if (Context->isFileContext()) 1414 return S.getOwningModule(Entity); 1415 return getDefiningModule(S, cast<Decl>(Context)); 1416} 1417 1418llvm::DenseSet<Module*> &Sema::getLookupModules() { 1419 unsigned N = ActiveTemplateInstantiations.size(); 1420 for (unsigned I = ActiveTemplateInstantiationLookupModules.size(); 1421 I != N; ++I) { 1422 Module *M = 1423 getDefiningModule(*this, ActiveTemplateInstantiations[I].Entity); 1424 if (M && !LookupModulesCache.insert(M).second) 1425 M = nullptr; 1426 ActiveTemplateInstantiationLookupModules.push_back(M); 1427 } 1428 return LookupModulesCache; 1429} 1430 1431bool Sema::hasVisibleMergedDefinition(NamedDecl *Def) { 1432 for (Module *Merged : Context.getModulesWithMergedDefinition(Def)) 1433 if (isModuleVisible(Merged)) 1434 return true; 1435 return false; 1436} 1437 1438template<typename ParmDecl> 1439static bool 1440hasVisibleDefaultArgument(Sema &S, const ParmDecl *D, 1441 llvm::SmallVectorImpl<Module *> *Modules) { 1442 if (!D->hasDefaultArgument()) 1443 return false; 1444 1445 while (D) { 1446 auto &DefaultArg = D->getDefaultArgStorage(); 1447 if (!DefaultArg.isInherited() && S.isVisible(D)) 1448 return true; 1449 1450 if (!DefaultArg.isInherited() && Modules) { 1451 auto *NonConstD = const_cast<ParmDecl*>(D); 1452 Modules->push_back(S.getOwningModule(NonConstD)); 1453 const auto &Merged = S.Context.getModulesWithMergedDefinition(NonConstD); 1454 Modules->insert(Modules->end(), Merged.begin(), Merged.end()); 1455 } 1456 1457 // If there was a previous default argument, maybe its parameter is visible. 1458 D = DefaultArg.getInheritedFrom(); 1459 } 1460 return false; 1461} 1462 1463bool Sema::hasVisibleDefaultArgument(const NamedDecl *D, 1464 llvm::SmallVectorImpl<Module *> *Modules) { 1465 if (auto *P = dyn_cast<TemplateTypeParmDecl>(D)) 1466 return ::hasVisibleDefaultArgument(*this, P, Modules); 1467 if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D)) 1468 return ::hasVisibleDefaultArgument(*this, P, Modules); 1469 return ::hasVisibleDefaultArgument(*this, cast<TemplateTemplateParmDecl>(D), 1470 Modules); 1471} 1472 1473/// \brief Determine whether a declaration is visible to name lookup. 1474/// 1475/// This routine determines whether the declaration D is visible in the current 1476/// lookup context, taking into account the current template instantiation 1477/// stack. During template instantiation, a declaration is visible if it is 1478/// visible from a module containing any entity on the template instantiation 1479/// path (by instantiating a template, you allow it to see the declarations that 1480/// your module can see, including those later on in your module). 1481bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) { 1482 assert(D->isHidden() && "should not call this: not in slow case"); 1483 Module *DeclModule = nullptr; 1484 1485 if (SemaRef.getLangOpts().ModulesLocalVisibility) { 1486 DeclModule = SemaRef.getOwningModule(D); 1487 if (!DeclModule) { 1488 // getOwningModule() may have decided the declaration should not be hidden. 1489 assert(!D->isHidden() && "hidden decl not from a module"); 1490 return true; 1491 } 1492 1493 // If the owning module is visible, and the decl is not module private, 1494 // then the decl is visible too. (Module private is ignored within the same 1495 // top-level module.) 1496 if ((!D->isFromASTFile() || !D->isModulePrivate()) && 1497 (SemaRef.isModuleVisible(DeclModule) || 1498 SemaRef.hasVisibleMergedDefinition(D))) 1499 return true; 1500 } 1501 1502 // If this declaration is not at namespace scope nor module-private, 1503 // then it is visible if its lexical parent has a visible definition. 1504 DeclContext *DC = D->getLexicalDeclContext(); 1505 if (!D->isModulePrivate() && 1506 DC && !DC->isFileContext() && !isa<LinkageSpecDecl>(DC)) { 1507 // For a parameter, check whether our current template declaration's 1508 // lexical context is visible, not whether there's some other visible 1509 // definition of it, because parameters aren't "within" the definition. 1510 if ((D->isTemplateParameter() || isa<ParmVarDecl>(D)) 1511 ? isVisible(SemaRef, cast<NamedDecl>(DC)) 1512 : SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC))) { 1513 if (SemaRef.ActiveTemplateInstantiations.empty() && 1514 // FIXME: Do something better in this case. 1515 !SemaRef.getLangOpts().ModulesLocalVisibility) { 1516 // Cache the fact that this declaration is implicitly visible because 1517 // its parent has a visible definition. 1518 D->setHidden(false); 1519 } 1520 return true; 1521 } 1522 return false; 1523 } 1524 1525 // Find the extra places where we need to look. 1526 llvm::DenseSet<Module*> &LookupModules = SemaRef.getLookupModules(); 1527 if (LookupModules.empty()) 1528 return false; 1529 1530 if (!DeclModule) { 1531 DeclModule = SemaRef.getOwningModule(D); 1532 assert(DeclModule && "hidden decl not from a module"); 1533 } 1534 1535 // If our lookup set contains the decl's module, it's visible. 1536 if (LookupModules.count(DeclModule)) 1537 return true; 1538 1539 // If the declaration isn't exported, it's not visible in any other module. 1540 if (D->isModulePrivate()) 1541 return false; 1542 1543 // Check whether DeclModule is transitively exported to an import of 1544 // the lookup set. 1545 return std::any_of(LookupModules.begin(), LookupModules.end(), 1546 [&](Module *M) { return M->isModuleVisible(DeclModule); }); 1547} 1548 1549bool Sema::isVisibleSlow(const NamedDecl *D) { 1550 return LookupResult::isVisible(*this, const_cast<NamedDecl*>(D)); 1551} 1552 1553bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) { 1554 for (auto *D : R) { 1555 if (isVisible(D)) 1556 return true; 1557 } 1558 return New->isExternallyVisible(); 1559} 1560 1561/// \brief Retrieve the visible declaration corresponding to D, if any. 1562/// 1563/// This routine determines whether the declaration D is visible in the current 1564/// module, with the current imports. If not, it checks whether any 1565/// redeclaration of D is visible, and if so, returns that declaration. 1566/// 1567/// \returns D, or a visible previous declaration of D, whichever is more recent 1568/// and visible. If no declaration of D is visible, returns null. 1569static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D) { 1570 assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case"); 1571 1572 for (auto RD : D->redecls()) { 1573 if (auto ND = dyn_cast<NamedDecl>(RD)) { 1574 // FIXME: This is wrong in the case where the previous declaration is not 1575 // visible in the same scope as D. This needs to be done much more 1576 // carefully. 1577 if (LookupResult::isVisible(SemaRef, ND)) 1578 return ND; 1579 } 1580 } 1581 1582 return nullptr; 1583} 1584 1585NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const { 1586 return findAcceptableDecl(getSema(), D); 1587} 1588 1589/// @brief Perform unqualified name lookup starting from a given 1590/// scope. 1591/// 1592/// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is 1593/// used to find names within the current scope. For example, 'x' in 1594/// @code 1595/// int x; 1596/// int f() { 1597/// return x; // unqualified name look finds 'x' in the global scope 1598/// } 1599/// @endcode 1600/// 1601/// Different lookup criteria can find different names. For example, a 1602/// particular scope can have both a struct and a function of the same 1603/// name, and each can be found by certain lookup criteria. For more 1604/// information about lookup criteria, see the documentation for the 1605/// class LookupCriteria. 1606/// 1607/// @param S The scope from which unqualified name lookup will 1608/// begin. If the lookup criteria permits, name lookup may also search 1609/// in the parent scopes. 1610/// 1611/// @param [in,out] R Specifies the lookup to perform (e.g., the name to 1612/// look up and the lookup kind), and is updated with the results of lookup 1613/// including zero or more declarations and possibly additional information 1614/// used to diagnose ambiguities. 1615/// 1616/// @returns \c true if lookup succeeded and false otherwise. 1617bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) { 1618 DeclarationName Name = R.getLookupName(); 1619 if (!Name) return false; 1620 1621 LookupNameKind NameKind = R.getLookupKind(); 1622 1623 if (!getLangOpts().CPlusPlus) { 1624 // Unqualified name lookup in C/Objective-C is purely lexical, so 1625 // search in the declarations attached to the name. 1626 if (NameKind == Sema::LookupRedeclarationWithLinkage) { 1627 // Find the nearest non-transparent declaration scope. 1628 while (!(S->getFlags() & Scope::DeclScope) || 1629 (S->getEntity() && S->getEntity()->isTransparentContext())) 1630 S = S->getParent(); 1631 } 1632 1633 // When performing a scope lookup, we want to find local extern decls. 1634 FindLocalExternScope FindLocals(R); 1635 1636 // Scan up the scope chain looking for a decl that matches this 1637 // identifier that is in the appropriate namespace. This search 1638 // should not take long, as shadowing of names is uncommon, and 1639 // deep shadowing is extremely uncommon. 1640 bool LeftStartingScope = false; 1641 1642 for (IdentifierResolver::iterator I = IdResolver.begin(Name), 1643 IEnd = IdResolver.end(); 1644 I != IEnd; ++I) 1645 if (NamedDecl *D = R.getAcceptableDecl(*I)) { 1646 if (NameKind == LookupRedeclarationWithLinkage) { 1647 // Determine whether this (or a previous) declaration is 1648 // out-of-scope. 1649 if (!LeftStartingScope && !S->isDeclScope(*I)) 1650 LeftStartingScope = true; 1651 1652 // If we found something outside of our starting scope that 1653 // does not have linkage, skip it. 1654 if (LeftStartingScope && !((*I)->hasLinkage())) { 1655 R.setShadowed(); 1656 continue; 1657 } 1658 } 1659 else if (NameKind == LookupObjCImplicitSelfParam && 1660 !isa<ImplicitParamDecl>(*I)) 1661 continue; 1662 1663 R.addDecl(D); 1664 1665 // Check whether there are any other declarations with the same name 1666 // and in the same scope. 1667 if (I != IEnd) { 1668 // Find the scope in which this declaration was declared (if it 1669 // actually exists in a Scope). 1670 while (S && !S->isDeclScope(D)) 1671 S = S->getParent(); 1672 1673 // If the scope containing the declaration is the translation unit, 1674 // then we'll need to perform our checks based on the matching 1675 // DeclContexts rather than matching scopes. 1676 if (S && isNamespaceOrTranslationUnitScope(S)) 1677 S = nullptr; 1678 1679 // Compute the DeclContext, if we need it. 1680 DeclContext *DC = nullptr; 1681 if (!S) 1682 DC = (*I)->getDeclContext()->getRedeclContext(); 1683 1684 IdentifierResolver::iterator LastI = I; 1685 for (++LastI; LastI != IEnd; ++LastI) { 1686 if (S) { 1687 // Match based on scope. 1688 if (!S->isDeclScope(*LastI)) 1689 break; 1690 } else { 1691 // Match based on DeclContext. 1692 DeclContext *LastDC 1693 = (*LastI)->getDeclContext()->getRedeclContext(); 1694 if (!LastDC->Equals(DC)) 1695 break; 1696 } 1697 1698 // If the declaration is in the right namespace and visible, add it. 1699 if (NamedDecl *LastD = R.getAcceptableDecl(*LastI)) 1700 R.addDecl(LastD); 1701 } 1702 1703 R.resolveKind(); 1704 } 1705 1706 return true; 1707 } 1708 } else { 1709 // Perform C++ unqualified name lookup. 1710 if (CppLookupName(R, S)) 1711 return true; 1712 } 1713 1714 // If we didn't find a use of this identifier, and if the identifier 1715 // corresponds to a compiler builtin, create the decl object for the builtin 1716 // now, injecting it into translation unit scope, and return it. 1717 if (AllowBuiltinCreation && LookupBuiltin(*this, R)) 1718 return true; 1719 1720 // If we didn't find a use of this identifier, the ExternalSource 1721 // may be able to handle the situation. 1722 // Note: some lookup failures are expected! 1723 // See e.g. R.isForRedeclaration(). 1724 return (ExternalSource && ExternalSource->LookupUnqualified(R, S)); 1725} 1726 1727/// @brief Perform qualified name lookup in the namespaces nominated by 1728/// using directives by the given context. 1729/// 1730/// C++98 [namespace.qual]p2: 1731/// Given X::m (where X is a user-declared namespace), or given \::m 1732/// (where X is the global namespace), let S be the set of all 1733/// declarations of m in X and in the transitive closure of all 1734/// namespaces nominated by using-directives in X and its used 1735/// namespaces, except that using-directives are ignored in any 1736/// namespace, including X, directly containing one or more 1737/// declarations of m. No namespace is searched more than once in 1738/// the lookup of a name. If S is the empty set, the program is 1739/// ill-formed. Otherwise, if S has exactly one member, or if the 1740/// context of the reference is a using-declaration 1741/// (namespace.udecl), S is the required set of declarations of 1742/// m. Otherwise if the use of m is not one that allows a unique 1743/// declaration to be chosen from S, the program is ill-formed. 1744/// 1745/// C++98 [namespace.qual]p5: 1746/// During the lookup of a qualified namespace member name, if the 1747/// lookup finds more than one declaration of the member, and if one 1748/// declaration introduces a class name or enumeration name and the 1749/// other declarations either introduce the same object, the same 1750/// enumerator or a set of functions, the non-type name hides the 1751/// class or enumeration name if and only if the declarations are 1752/// from the same namespace; otherwise (the declarations are from 1753/// different namespaces), the program is ill-formed. 1754static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R, 1755 DeclContext *StartDC) { 1756 assert(StartDC->isFileContext() && "start context is not a file context"); 1757 1758 DeclContext::udir_range UsingDirectives = StartDC->using_directives(); 1759 if (UsingDirectives.begin() == UsingDirectives.end()) return false; 1760 1761 // We have at least added all these contexts to the queue. 1762 llvm::SmallPtrSet<DeclContext*, 8> Visited; 1763 Visited.insert(StartDC); 1764 1765 // We have not yet looked into these namespaces, much less added 1766 // their "using-children" to the queue. 1767 SmallVector<NamespaceDecl*, 8> Queue; 1768 1769 // We have already looked into the initial namespace; seed the queue 1770 // with its using-children. 1771 for (auto *I : UsingDirectives) { 1772 NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace(); 1773 if (Visited.insert(ND).second) 1774 Queue.push_back(ND); 1775 } 1776 1777 // The easiest way to implement the restriction in [namespace.qual]p5 1778 // is to check whether any of the individual results found a tag 1779 // and, if so, to declare an ambiguity if the final result is not 1780 // a tag. 1781 bool FoundTag = false; 1782 bool FoundNonTag = false; 1783 1784 LookupResult LocalR(LookupResult::Temporary, R); 1785 1786 bool Found = false; 1787 while (!Queue.empty()) { 1788 NamespaceDecl *ND = Queue.pop_back_val(); 1789 1790 // We go through some convolutions here to avoid copying results 1791 // between LookupResults. 1792 bool UseLocal = !R.empty(); 1793 LookupResult &DirectR = UseLocal ? LocalR : R; 1794 bool FoundDirect = LookupDirect(S, DirectR, ND); 1795 1796 if (FoundDirect) { 1797 // First do any local hiding. 1798 DirectR.resolveKind(); 1799 1800 // If the local result is a tag, remember that. 1801 if (DirectR.isSingleTagDecl()) 1802 FoundTag = true; 1803 else 1804 FoundNonTag = true; 1805 1806 // Append the local results to the total results if necessary. 1807 if (UseLocal) { 1808 R.addAllDecls(LocalR); 1809 LocalR.clear(); 1810 } 1811 } 1812 1813 // If we find names in this namespace, ignore its using directives. 1814 if (FoundDirect) { 1815 Found = true; 1816 continue; 1817 } 1818 1819 for (auto I : ND->using_directives()) { 1820 NamespaceDecl *Nom = I->getNominatedNamespace(); 1821 if (Visited.insert(Nom).second) 1822 Queue.push_back(Nom); 1823 } 1824 } 1825 1826 if (Found) { 1827 if (FoundTag && FoundNonTag) 1828 R.setAmbiguousQualifiedTagHiding(); 1829 else 1830 R.resolveKind(); 1831 } 1832 1833 return Found; 1834} 1835 1836/// \brief Callback that looks for any member of a class with the given name. 1837static bool LookupAnyMember(const CXXBaseSpecifier *Specifier, 1838 CXXBasePath &Path, DeclarationName Name) { 1839 RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl(); 1840 1841 Path.Decls = BaseRecord->lookup(Name); 1842 return !Path.Decls.empty(); 1843} 1844 1845/// \brief Determine whether the given set of member declarations contains only 1846/// static members, nested types, and enumerators. 1847template<typename InputIterator> 1848static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) { 1849 Decl *D = (*First)->getUnderlyingDecl(); 1850 if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D)) 1851 return true; 1852 1853 if (isa<CXXMethodDecl>(D)) { 1854 // Determine whether all of the methods are static. 1855 bool AllMethodsAreStatic = true; 1856 for(; First != Last; ++First) { 1857 D = (*First)->getUnderlyingDecl(); 1858 1859 if (!isa<CXXMethodDecl>(D)) { 1860 assert(isa<TagDecl>(D) && "Non-function must be a tag decl"); 1861 break; 1862 } 1863 1864 if (!cast<CXXMethodDecl>(D)->isStatic()) { 1865 AllMethodsAreStatic = false; 1866 break; 1867 } 1868 } 1869 1870 if (AllMethodsAreStatic) 1871 return true; 1872 } 1873 1874 return false; 1875} 1876 1877/// \brief Perform qualified name lookup into a given context. 1878/// 1879/// Qualified name lookup (C++ [basic.lookup.qual]) is used to find 1880/// names when the context of those names is explicit specified, e.g., 1881/// "std::vector" or "x->member", or as part of unqualified name lookup. 1882/// 1883/// Different lookup criteria can find different names. For example, a 1884/// particular scope can have both a struct and a function of the same 1885/// name, and each can be found by certain lookup criteria. For more 1886/// information about lookup criteria, see the documentation for the 1887/// class LookupCriteria. 1888/// 1889/// \param R captures both the lookup criteria and any lookup results found. 1890/// 1891/// \param LookupCtx The context in which qualified name lookup will 1892/// search. If the lookup criteria permits, name lookup may also search 1893/// in the parent contexts or (for C++ classes) base classes. 1894/// 1895/// \param InUnqualifiedLookup true if this is qualified name lookup that 1896/// occurs as part of unqualified name lookup. 1897/// 1898/// \returns true if lookup succeeded, false if it failed. 1899bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 1900 bool InUnqualifiedLookup) { 1901 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context"); 1902 1903 if (!R.getLookupName()) 1904 return false; 1905 1906 // Make sure that the declaration context is complete. 1907 assert((!isa<TagDecl>(LookupCtx) || 1908 LookupCtx->isDependentContext() || 1909 cast<TagDecl>(LookupCtx)->isCompleteDefinition() || 1910 cast<TagDecl>(LookupCtx)->isBeingDefined()) && 1911 "Declaration context must already be complete!"); 1912 1913 struct QualifiedLookupInScope { 1914 bool oldVal; 1915 DeclContext *Context; 1916 // Set flag in DeclContext informing debugger that we're looking for qualified name 1917 QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) { 1918 oldVal = ctx->setUseQualifiedLookup(); 1919 } 1920 ~QualifiedLookupInScope() { 1921 Context->setUseQualifiedLookup(oldVal); 1922 } 1923 } QL(LookupCtx); 1924 1925 if (LookupDirect(*this, R, LookupCtx)) { 1926 R.resolveKind(); 1927 if (isa<CXXRecordDecl>(LookupCtx)) 1928 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx)); 1929 return true; 1930 } 1931 1932 // Don't descend into implied contexts for redeclarations. 1933 // C++98 [namespace.qual]p6: 1934 // In a declaration for a namespace member in which the 1935 // declarator-id is a qualified-id, given that the qualified-id 1936 // for the namespace member has the form 1937 // nested-name-specifier unqualified-id 1938 // the unqualified-id shall name a member of the namespace 1939 // designated by the nested-name-specifier. 1940 // See also [class.mfct]p5 and [class.static.data]p2. 1941 if (R.isForRedeclaration()) 1942 return false; 1943 1944 // If this is a namespace, look it up in the implied namespaces. 1945 if (LookupCtx->isFileContext()) 1946 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx); 1947 1948 // If this isn't a C++ class, we aren't allowed to look into base 1949 // classes, we're done. 1950 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx); 1951 if (!LookupRec || !LookupRec->getDefinition()) 1952 return false; 1953 1954 // If we're performing qualified name lookup into a dependent class, 1955 // then we are actually looking into a current instantiation. If we have any 1956 // dependent base classes, then we either have to delay lookup until 1957 // template instantiation time (at which point all bases will be available) 1958 // or we have to fail. 1959 if (!InUnqualifiedLookup && LookupRec->isDependentContext() && 1960 LookupRec->hasAnyDependentBases()) { 1961 R.setNotFoundInCurrentInstantiation(); 1962 return false; 1963 } 1964 1965 // Perform lookup into our base classes. 1966 CXXBasePaths Paths; 1967 Paths.setOrigin(LookupRec); 1968 1969 // Look for this member in our base classes 1970 bool (*BaseCallback)(const CXXBaseSpecifier *Specifier, CXXBasePath &Path, 1971 DeclarationName Name) = nullptr; 1972 switch (R.getLookupKind()) { 1973 case LookupObjCImplicitSelfParam: 1974 case LookupOrdinaryName: 1975 case LookupMemberName: 1976 case LookupRedeclarationWithLinkage: 1977 case LookupLocalFriendName: 1978 BaseCallback = &CXXRecordDecl::FindOrdinaryMember; 1979 break; 1980 1981 case LookupTagName: 1982 BaseCallback = &CXXRecordDecl::FindTagMember; 1983 break; 1984 1985 case LookupAnyName: 1986 BaseCallback = &LookupAnyMember; 1987 break; 1988 1989 case LookupUsingDeclName: 1990 // This lookup is for redeclarations only. 1991 1992 case LookupOperatorName: 1993 case LookupNamespaceName: 1994 case LookupObjCProtocolName: 1995 case LookupLabel: 1996 // These lookups will never find a member in a C++ class (or base class). 1997 return false; 1998 1999 case LookupNestedNameSpecifierName: 2000 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember; 2001 break; 2002 } 2003 2004 DeclarationName Name = R.getLookupName(); 2005 if (!LookupRec->lookupInBases( 2006 [=](const CXXBaseSpecifier *Specifier, CXXBasePath &Path) { 2007 return BaseCallback(Specifier, Path, Name); 2008 }, 2009 Paths)) 2010 return false; 2011 2012 R.setNamingClass(LookupRec); 2013 2014 // C++ [class.member.lookup]p2: 2015 // [...] If the resulting set of declarations are not all from 2016 // sub-objects of the same type, or the set has a nonstatic member 2017 // and includes members from distinct sub-objects, there is an 2018 // ambiguity and the program is ill-formed. Otherwise that set is 2019 // the result of the lookup. 2020 QualType SubobjectType; 2021 int SubobjectNumber = 0; 2022 AccessSpecifier SubobjectAccess = AS_none; 2023 2024 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); 2025 Path != PathEnd; ++Path) { 2026 const CXXBasePathElement &PathElement = Path->back(); 2027 2028 // Pick the best (i.e. most permissive i.e. numerically lowest) access 2029 // across all paths. 2030 SubobjectAccess = std::min(SubobjectAccess, Path->Access); 2031 2032 // Determine whether we're looking at a distinct sub-object or not. 2033 if (SubobjectType.isNull()) { 2034 // This is the first subobject we've looked at. Record its type. 2035 SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); 2036 SubobjectNumber = PathElement.SubobjectNumber; 2037 continue; 2038 } 2039 2040 if (SubobjectType 2041 != Context.getCanonicalType(PathElement.Base->getType())) { 2042 // We found members of the given name in two subobjects of 2043 // different types. If the declaration sets aren't the same, this 2044 // lookup is ambiguous. 2045 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) { 2046 CXXBasePaths::paths_iterator FirstPath = Paths.begin(); 2047 DeclContext::lookup_iterator FirstD = FirstPath->Decls.begin(); 2048 DeclContext::lookup_iterator CurrentD = Path->Decls.begin(); 2049 2050 while (FirstD != FirstPath->Decls.end() && 2051 CurrentD != Path->Decls.end()) { 2052 if ((*FirstD)->getUnderlyingDecl()->getCanonicalDecl() != 2053 (*CurrentD)->getUnderlyingDecl()->getCanonicalDecl()) 2054 break; 2055 2056 ++FirstD; 2057 ++CurrentD; 2058 } 2059 2060 if (FirstD == FirstPath->Decls.end() && 2061 CurrentD == Path->Decls.end()) 2062 continue; 2063 } 2064 2065 R.setAmbiguousBaseSubobjectTypes(Paths); 2066 return true; 2067 } 2068 2069 if (SubobjectNumber != PathElement.SubobjectNumber) { 2070 // We have a different subobject of the same type. 2071 2072 // C++ [class.member.lookup]p5: 2073 // A static member, a nested type or an enumerator defined in 2074 // a base class T can unambiguously be found even if an object 2075 // has more than one base class subobject of type T. 2076 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) 2077 continue; 2078 2079 // We have found a nonstatic member name in multiple, distinct 2080 // subobjects. Name lookup is ambiguous. 2081 R.setAmbiguousBaseSubobjects(Paths); 2082 return true; 2083 } 2084 } 2085 2086 // Lookup in a base class succeeded; return these results. 2087 2088 for (auto *D : Paths.front().Decls) { 2089 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess, 2090 D->getAccess()); 2091 R.addDecl(D, AS); 2092 } 2093 R.resolveKind(); 2094 return true; 2095} 2096 2097/// \brief Performs qualified name lookup or special type of lookup for 2098/// "__super::" scope specifier. 2099/// 2100/// This routine is a convenience overload meant to be called from contexts 2101/// that need to perform a qualified name lookup with an optional C++ scope 2102/// specifier that might require special kind of lookup. 2103/// 2104/// \param R captures both the lookup criteria and any lookup results found. 2105/// 2106/// \param LookupCtx The context in which qualified name lookup will 2107/// search. 2108/// 2109/// \param SS An optional C++ scope-specifier. 2110/// 2111/// \returns true if lookup succeeded, false if it failed. 2112bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 2113 CXXScopeSpec &SS) { 2114 auto *NNS = SS.getScopeRep(); 2115 if (NNS && NNS->getKind() == NestedNameSpecifier::Super) 2116 return LookupInSuper(R, NNS->getAsRecordDecl()); 2117 else 2118 2119 return LookupQualifiedName(R, LookupCtx); 2120} 2121 2122/// @brief Performs name lookup for a name that was parsed in the 2123/// source code, and may contain a C++ scope specifier. 2124/// 2125/// This routine is a convenience routine meant to be called from 2126/// contexts that receive a name and an optional C++ scope specifier 2127/// (e.g., "N::M::x"). It will then perform either qualified or 2128/// unqualified name lookup (with LookupQualifiedName or LookupName, 2129/// respectively) on the given name and return those results. It will 2130/// perform a special type of lookup for "__super::" scope specifier. 2131/// 2132/// @param S The scope from which unqualified name lookup will 2133/// begin. 2134/// 2135/// @param SS An optional C++ scope-specifier, e.g., "::N::M". 2136/// 2137/// @param EnteringContext Indicates whether we are going to enter the 2138/// context of the scope-specifier SS (if present). 2139/// 2140/// @returns True if any decls were found (but possibly ambiguous) 2141bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS, 2142 bool AllowBuiltinCreation, bool EnteringContext) { 2143 if (SS && SS->isInvalid()) { 2144 // When the scope specifier is invalid, don't even look for 2145 // anything. 2146 return false; 2147 } 2148 2149 if (SS && SS->isSet()) { 2150 NestedNameSpecifier *NNS = SS->getScopeRep(); 2151 if (NNS->getKind() == NestedNameSpecifier::Super) 2152 return LookupInSuper(R, NNS->getAsRecordDecl()); 2153 2154 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { 2155 // We have resolved the scope specifier to a particular declaration 2156 // contex, and will perform name lookup in that context. 2157 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC)) 2158 return false; 2159 2160 R.setContextRange(SS->getRange()); 2161 return LookupQualifiedName(R, DC); 2162 } 2163 2164 // We could not resolve the scope specified to a specific declaration 2165 // context, which means that SS refers to an unknown specialization. 2166 // Name lookup can't find anything in this case. 2167 R.setNotFoundInCurrentInstantiation(); 2168 R.setContextRange(SS->getRange()); 2169 return false; 2170 } 2171 2172 // Perform unqualified name lookup starting in the given scope. 2173 return LookupName(R, S, AllowBuiltinCreation); 2174} 2175 2176/// \brief Perform qualified name lookup into all base classes of the given 2177/// class. 2178/// 2179/// \param R captures both the lookup criteria and any lookup results found. 2180/// 2181/// \param Class The context in which qualified name lookup will 2182/// search. Name lookup will search in all base classes merging the results. 2183/// 2184/// @returns True if any decls were found (but possibly ambiguous) 2185bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) { 2186 // The access-control rules we use here are essentially the rules for 2187 // doing a lookup in Class that just magically skipped the direct 2188 // members of Class itself. That is, the naming class is Class, and the 2189 // access includes the access of the base. 2190 for (const auto &BaseSpec : Class->bases()) { 2191 CXXRecordDecl *RD = cast<CXXRecordDecl>( 2192 BaseSpec.getType()->castAs<RecordType>()->getDecl()); 2193 LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind()); 2194 Result.setBaseObjectType(Context.getRecordType(Class)); 2195 LookupQualifiedName(Result, RD); 2196 2197 // Copy the lookup results into the target, merging the base's access into 2198 // the path access. 2199 for (auto I = Result.begin(), E = Result.end(); I != E; ++I) { 2200 R.addDecl(I.getDecl(), 2201 CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(), 2202 I.getAccess())); 2203 } 2204 2205 Result.suppressDiagnostics(); 2206 } 2207 2208 R.resolveKind(); 2209 R.setNamingClass(Class); 2210 2211 return !R.empty(); 2212} 2213 2214/// \brief Produce a diagnostic describing the ambiguity that resulted 2215/// from name lookup. 2216/// 2217/// \param Result The result of the ambiguous lookup to be diagnosed. 2218void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) { 2219 assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); 2220 2221 DeclarationName Name = Result.getLookupName(); 2222 SourceLocation NameLoc = Result.getNameLoc(); 2223 SourceRange LookupRange = Result.getContextRange(); 2224 2225 switch (Result.getAmbiguityKind()) { 2226 case LookupResult::AmbiguousBaseSubobjects: { 2227 CXXBasePaths *Paths = Result.getBasePaths(); 2228 QualType SubobjectType = Paths->front().back().Base->getType(); 2229 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) 2230 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) 2231 << LookupRange; 2232 2233 DeclContext::lookup_iterator Found = Paths->front().Decls.begin(); 2234 while (isa<CXXMethodDecl>(*Found) && 2235 cast<CXXMethodDecl>(*Found)->isStatic()) 2236 ++Found; 2237 2238 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); 2239 break; 2240 } 2241 2242 case LookupResult::AmbiguousBaseSubobjectTypes: { 2243 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) 2244 << Name << LookupRange; 2245 2246 CXXBasePaths *Paths = Result.getBasePaths(); 2247 std::set<Decl *> DeclsPrinted; 2248 for (CXXBasePaths::paths_iterator Path = Paths->begin(), 2249 PathEnd = Paths->end(); 2250 Path != PathEnd; ++Path) { 2251 Decl *D = Path->Decls.front(); 2252 if (DeclsPrinted.insert(D).second) 2253 Diag(D->getLocation(), diag::note_ambiguous_member_found); 2254 } 2255 break; 2256 } 2257 2258 case LookupResult::AmbiguousTagHiding: { 2259 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange; 2260 2261 llvm::SmallPtrSet<NamedDecl*, 8> TagDecls; 2262 2263 for (auto *D : Result) 2264 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 2265 TagDecls.insert(TD); 2266 Diag(TD->getLocation(), diag::note_hidden_tag); 2267 } 2268 2269 for (auto *D : Result) 2270 if (!isa<TagDecl>(D)) 2271 Diag(D->getLocation(), diag::note_hiding_object); 2272 2273 // For recovery purposes, go ahead and implement the hiding. 2274 LookupResult::Filter F = Result.makeFilter(); 2275 while (F.hasNext()) { 2276 if (TagDecls.count(F.next())) 2277 F.erase(); 2278 } 2279 F.done(); 2280 break; 2281 } 2282 2283 case LookupResult::AmbiguousReference: { 2284 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; 2285 2286 for (auto *D : Result) 2287 Diag(D->getLocation(), diag::note_ambiguous_candidate) << D; 2288 break; 2289 } 2290 } 2291} 2292 2293namespace { 2294 struct AssociatedLookup { 2295 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc, 2296 Sema::AssociatedNamespaceSet &Namespaces, 2297 Sema::AssociatedClassSet &Classes) 2298 : S(S), Namespaces(Namespaces), Classes(Classes), 2299 InstantiationLoc(InstantiationLoc) { 2300 } 2301 2302 Sema &S; 2303 Sema::AssociatedNamespaceSet &Namespaces; 2304 Sema::AssociatedClassSet &Classes; 2305 SourceLocation InstantiationLoc; 2306 }; 2307} // end anonymous namespace 2308 2309static void 2310addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T); 2311 2312static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces, 2313 DeclContext *Ctx) { 2314 // Add the associated namespace for this class. 2315 2316 // We don't use DeclContext::getEnclosingNamespaceContext() as this may 2317 // be a locally scoped record. 2318 2319 // We skip out of inline namespaces. The innermost non-inline namespace 2320 // contains all names of all its nested inline namespaces anyway, so we can 2321 // replace the entire inline namespace tree with its root. 2322 while (Ctx->isRecord() || Ctx->isTransparentContext() || 2323 Ctx->isInlineNamespace()) 2324 Ctx = Ctx->getParent(); 2325 2326 if (Ctx->isFileContext()) 2327 Namespaces.insert(Ctx->getPrimaryContext()); 2328} 2329 2330// \brief Add the associated classes and namespaces for argument-dependent 2331// lookup that involves a template argument (C++ [basic.lookup.koenig]p2). 2332static void 2333addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 2334 const TemplateArgument &Arg) { 2335 // C++ [basic.lookup.koenig]p2, last bullet: 2336 // -- [...] ; 2337 switch (Arg.getKind()) { 2338 case TemplateArgument::Null: 2339 break; 2340 2341 case TemplateArgument::Type: 2342 // [...] the namespaces and classes associated with the types of the 2343 // template arguments provided for template type parameters (excluding 2344 // template template parameters) 2345 addAssociatedClassesAndNamespaces(Result, Arg.getAsType()); 2346 break; 2347 2348 case TemplateArgument::Template: 2349 case TemplateArgument::TemplateExpansion: { 2350 // [...] the namespaces in which any template template arguments are 2351 // defined; and the classes in which any member templates used as 2352 // template template arguments are defined. 2353 TemplateName Template = Arg.getAsTemplateOrTemplatePattern(); 2354 if (ClassTemplateDecl *ClassTemplate 2355 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) { 2356 DeclContext *Ctx = ClassTemplate->getDeclContext(); 2357 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2358 Result.Classes.insert(EnclosingClass); 2359 // Add the associated namespace for this class. 2360 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2361 } 2362 break; 2363 } 2364 2365 case TemplateArgument::Declaration: 2366 case TemplateArgument::Integral: 2367 case TemplateArgument::Expression: 2368 case TemplateArgument::NullPtr: 2369 // [Note: non-type template arguments do not contribute to the set of 2370 // associated namespaces. ] 2371 break; 2372 2373 case TemplateArgument::Pack: 2374 for (const auto &P : Arg.pack_elements()) 2375 addAssociatedClassesAndNamespaces(Result, P); 2376 break; 2377 } 2378} 2379 2380// \brief Add the associated classes and namespaces for 2381// argument-dependent lookup with an argument of class type 2382// (C++ [basic.lookup.koenig]p2). 2383static void 2384addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 2385 CXXRecordDecl *Class) { 2386 2387 // Just silently ignore anything whose name is __va_list_tag. 2388 if (Class->getDeclName() == Result.S.VAListTagName) 2389 return; 2390 2391 // C++ [basic.lookup.koenig]p2: 2392 // [...] 2393 // -- If T is a class type (including unions), its associated 2394 // classes are: the class itself; the class of which it is a 2395 // member, if any; and its direct and indirect base 2396 // classes. Its associated namespaces are the namespaces in 2397 // which its associated classes are defined. 2398 2399 // Add the class of which it is a member, if any. 2400 DeclContext *Ctx = Class->getDeclContext(); 2401 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2402 Result.Classes.insert(EnclosingClass); 2403 // Add the associated namespace for this class. 2404 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2405 2406 // Add the class itself. If we've already seen this class, we don't 2407 // need to visit base classes. 2408 // 2409 // FIXME: That's not correct, we may have added this class only because it 2410 // was the enclosing class of another class, and in that case we won't have 2411 // added its base classes yet. 2412 if (!Result.Classes.insert(Class).second) 2413 return; 2414 2415 // -- If T is a template-id, its associated namespaces and classes are 2416 // the namespace in which the template is defined; for member 2417 // templates, the member template's class; the namespaces and classes 2418 // associated with the types of the template arguments provided for 2419 // template type parameters (excluding template template parameters); the 2420 // namespaces in which any template template arguments are defined; and 2421 // the classes in which any member templates used as template template 2422 // arguments are defined. [Note: non-type template arguments do not 2423 // contribute to the set of associated namespaces. ] 2424 if (ClassTemplateSpecializationDecl *Spec 2425 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) { 2426 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); 2427 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2428 Result.Classes.insert(EnclosingClass); 2429 // Add the associated namespace for this class. 2430 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2431 2432 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); 2433 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 2434 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]); 2435 } 2436 2437 // Only recurse into base classes for complete types. 2438 if (!Result.S.isCompleteType(Result.InstantiationLoc, 2439 Result.S.Context.getRecordType(Class))) 2440 return; 2441 2442 // Add direct and indirect base classes along with their associated 2443 // namespaces. 2444 SmallVector<CXXRecordDecl *, 32> Bases; 2445 Bases.push_back(Class); 2446 while (!Bases.empty()) { 2447 // Pop this class off the stack. 2448 Class = Bases.pop_back_val(); 2449 2450 // Visit the base classes. 2451 for (const auto &Base : Class->bases()) { 2452 const RecordType *BaseType = Base.getType()->getAs<RecordType>(); 2453 // In dependent contexts, we do ADL twice, and the first time around, 2454 // the base type might be a dependent TemplateSpecializationType, or a 2455 // TemplateTypeParmType. If that happens, simply ignore it. 2456 // FIXME: If we want to support export, we probably need to add the 2457 // namespace of the template in a TemplateSpecializationType, or even 2458 // the classes and namespaces of known non-dependent arguments. 2459 if (!BaseType) 2460 continue; 2461 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 2462 if (Result.Classes.insert(BaseDecl).second) { 2463 // Find the associated namespace for this base class. 2464 DeclContext *BaseCtx = BaseDecl->getDeclContext(); 2465 CollectEnclosingNamespace(Result.Namespaces, BaseCtx); 2466 2467 // Make sure we visit the bases of this base class. 2468 if (BaseDecl->bases_begin() != BaseDecl->bases_end()) 2469 Bases.push_back(BaseDecl); 2470 } 2471 } 2472 } 2473} 2474 2475// \brief Add the associated classes and namespaces for 2476// argument-dependent lookup with an argument of type T 2477// (C++ [basic.lookup.koenig]p2). 2478static void 2479addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) { 2480 // C++ [basic.lookup.koenig]p2: 2481 // 2482 // For each argument type T in the function call, there is a set 2483 // of zero or more associated namespaces and a set of zero or more 2484 // associated classes to be considered. The sets of namespaces and 2485 // classes is determined entirely by the types of the function 2486 // arguments (and the namespace of any template template 2487 // argument). Typedef names and using-declarations used to specify 2488 // the types do not contribute to this set. The sets of namespaces 2489 // and classes are determined in the following way: 2490 2491 SmallVector<const Type *, 16> Queue; 2492 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr(); 2493 2494 while (true) { 2495 switch (T->getTypeClass()) { 2496 2497#define TYPE(Class, Base) 2498#define DEPENDENT_TYPE(Class, Base) case Type::Class: 2499#define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 2500#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class: 2501#define ABSTRACT_TYPE(Class, Base) 2502#include "clang/AST/TypeNodes.def" 2503 // T is canonical. We can also ignore dependent types because 2504 // we don't need to do ADL at the definition point, but if we 2505 // wanted to implement template export (or if we find some other 2506 // use for associated classes and namespaces...) this would be 2507 // wrong. 2508 break; 2509 2510 // -- If T is a pointer to U or an array of U, its associated 2511 // namespaces and classes are those associated with U. 2512 case Type::Pointer: 2513 T = cast<PointerType>(T)->getPointeeType().getTypePtr(); 2514 continue; 2515 case Type::ConstantArray: 2516 case Type::IncompleteArray: 2517 case Type::VariableArray: 2518 T = cast<ArrayType>(T)->getElementType().getTypePtr(); 2519 continue; 2520 2521 // -- If T is a fundamental type, its associated sets of 2522 // namespaces and classes are both empty. 2523 case Type::Builtin: 2524 break; 2525 2526 // -- If T is a class type (including unions), its associated 2527 // classes are: the class itself; the class of which it is a 2528 // member, if any; and its direct and indirect base 2529 // classes. Its associated namespaces are the namespaces in 2530 // which its associated classes are defined. 2531 case Type::Record: { 2532 CXXRecordDecl *Class = 2533 cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl()); 2534 addAssociatedClassesAndNamespaces(Result, Class); 2535 break; 2536 } 2537 2538 // -- If T is an enumeration type, its associated namespace is 2539 // the namespace in which it is defined. If it is class 2540 // member, its associated class is the member's class; else 2541 // it has no associated class. 2542 case Type::Enum: { 2543 EnumDecl *Enum = cast<EnumType>(T)->getDecl(); 2544 2545 DeclContext *Ctx = Enum->getDeclContext(); 2546 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2547 Result.Classes.insert(EnclosingClass); 2548 2549 // Add the associated namespace for this class. 2550 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2551 2552 break; 2553 } 2554 2555 // -- If T is a function type, its associated namespaces and 2556 // classes are those associated with the function parameter 2557 // types and those associated with the return type. 2558 case Type::FunctionProto: { 2559 const FunctionProtoType *Proto = cast<FunctionProtoType>(T); 2560 for (const auto &Arg : Proto->param_types()) 2561 Queue.push_back(Arg.getTypePtr()); 2562 // fallthrough 2563 } 2564 case Type::FunctionNoProto: { 2565 const FunctionType *FnType = cast<FunctionType>(T); 2566 T = FnType->getReturnType().getTypePtr(); 2567 continue; 2568 } 2569 2570 // -- If T is a pointer to a member function of a class X, its 2571 // associated namespaces and classes are those associated 2572 // with the function parameter types and return type, 2573 // together with those associated with X. 2574 // 2575 // -- If T is a pointer to a data member of class X, its 2576 // associated namespaces and classes are those associated 2577 // with the member type together with those associated with 2578 // X. 2579 case Type::MemberPointer: { 2580 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T); 2581 2582 // Queue up the class type into which this points. 2583 Queue.push_back(MemberPtr->getClass()); 2584 2585 // And directly continue with the pointee type. 2586 T = MemberPtr->getPointeeType().getTypePtr(); 2587 continue; 2588 } 2589 2590 // As an extension, treat this like a normal pointer. 2591 case Type::BlockPointer: 2592 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr(); 2593 continue; 2594 2595 // References aren't covered by the standard, but that's such an 2596 // obvious defect that we cover them anyway. 2597 case Type::LValueReference: 2598 case Type::RValueReference: 2599 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr(); 2600 continue; 2601 2602 // These are fundamental types. 2603 case Type::Vector: 2604 case Type::ExtVector: 2605 case Type::Complex: 2606 break; 2607 2608 // Non-deduced auto types only get here for error cases. 2609 case Type::Auto: 2610 break; 2611 2612 // If T is an Objective-C object or interface type, or a pointer to an 2613 // object or interface type, the associated namespace is the global 2614 // namespace. 2615 case Type::ObjCObject: 2616 case Type::ObjCInterface: 2617 case Type::ObjCObjectPointer: 2618 Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl()); 2619 break; 2620 2621 // Atomic types are just wrappers; use the associations of the 2622 // contained type. 2623 case Type::Atomic: 2624 T = cast<AtomicType>(T)->getValueType().getTypePtr(); 2625 continue; 2626 case Type::Pipe: 2627 T = cast<PipeType>(T)->getElementType().getTypePtr(); 2628 continue; 2629 } 2630 2631 if (Queue.empty()) 2632 break; 2633 T = Queue.pop_back_val(); 2634 } 2635} 2636 2637/// \brief Find the associated classes and namespaces for 2638/// argument-dependent lookup for a call with the given set of 2639/// arguments. 2640/// 2641/// This routine computes the sets of associated classes and associated 2642/// namespaces searched by argument-dependent lookup 2643/// (C++ [basic.lookup.argdep]) for a given set of arguments. 2644void Sema::FindAssociatedClassesAndNamespaces( 2645 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args, 2646 AssociatedNamespaceSet &AssociatedNamespaces, 2647 AssociatedClassSet &AssociatedClasses) { 2648 AssociatedNamespaces.clear(); 2649 AssociatedClasses.clear(); 2650 2651 AssociatedLookup Result(*this, InstantiationLoc, 2652 AssociatedNamespaces, AssociatedClasses); 2653 2654 // C++ [basic.lookup.koenig]p2: 2655 // For each argument type T in the function call, there is a set 2656 // of zero or more associated namespaces and a set of zero or more 2657 // associated classes to be considered. The sets of namespaces and 2658 // classes is determined entirely by the types of the function 2659 // arguments (and the namespace of any template template 2660 // argument). 2661 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) { 2662 Expr *Arg = Args[ArgIdx]; 2663 2664 if (Arg->getType() != Context.OverloadTy) { 2665 addAssociatedClassesAndNamespaces(Result, Arg->getType()); 2666 continue; 2667 } 2668 2669 // [...] In addition, if the argument is the name or address of a 2670 // set of overloaded functions and/or function templates, its 2671 // associated classes and namespaces are the union of those 2672 // associated with each of the members of the set: the namespace 2673 // in which the function or function template is defined and the 2674 // classes and namespaces associated with its (non-dependent) 2675 // parameter types and return type. 2676 Arg = Arg->IgnoreParens(); 2677 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg)) 2678 if (unaryOp->getOpcode() == UO_AddrOf) 2679 Arg = unaryOp->getSubExpr(); 2680 2681 UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg); 2682 if (!ULE) continue; 2683 2684 for (const auto *D : ULE->decls()) { 2685 // Look through any using declarations to find the underlying function. 2686 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction(); 2687 2688 // Add the classes and namespaces associated with the parameter 2689 // types and return type of this function. 2690 addAssociatedClassesAndNamespaces(Result, FDecl->getType()); 2691 } 2692 } 2693} 2694 2695NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name, 2696 SourceLocation Loc, 2697 LookupNameKind NameKind, 2698 RedeclarationKind Redecl) { 2699 LookupResult R(*this, Name, Loc, NameKind, Redecl); 2700 LookupName(R, S); 2701 return R.getAsSingle<NamedDecl>(); 2702} 2703 2704/// \brief Find the protocol with the given name, if any. 2705ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II, 2706 SourceLocation IdLoc, 2707 RedeclarationKind Redecl) { 2708 Decl *D = LookupSingleName(TUScope, II, IdLoc, 2709 LookupObjCProtocolName, Redecl); 2710 return cast_or_null<ObjCProtocolDecl>(D); 2711} 2712 2713void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, 2714 QualType T1, QualType T2, 2715 UnresolvedSetImpl &Functions) { 2716 // C++ [over.match.oper]p3: 2717 // -- The set of non-member candidates is the result of the 2718 // unqualified lookup of operator@ in the context of the 2719 // expression according to the usual rules for name lookup in 2720 // unqualified function calls (3.4.2) except that all member 2721 // functions are ignored. 2722 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2723 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName); 2724 LookupName(Operators, S); 2725 2726 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); 2727 Functions.append(Operators.begin(), Operators.end()); 2728} 2729 2730Sema::SpecialMemberOverloadResult *Sema::LookupSpecialMember(CXXRecordDecl *RD, 2731 CXXSpecialMember SM, 2732 bool ConstArg, 2733 bool VolatileArg, 2734 bool RValueThis, 2735 bool ConstThis, 2736 bool VolatileThis) { 2737 assert(CanDeclareSpecialMemberFunction(RD) && 2738 "doing special member lookup into record that isn't fully complete"); 2739 RD = RD->getDefinition(); 2740 if (RValueThis || ConstThis || VolatileThis) 2741 assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) && 2742 "constructors and destructors always have unqualified lvalue this"); 2743 if (ConstArg || VolatileArg) 2744 assert((SM != CXXDefaultConstructor && SM != CXXDestructor) && 2745 "parameter-less special members can't have qualified arguments"); 2746 2747 llvm::FoldingSetNodeID ID; 2748 ID.AddPointer(RD); 2749 ID.AddInteger(SM); 2750 ID.AddInteger(ConstArg); 2751 ID.AddInteger(VolatileArg); 2752 ID.AddInteger(RValueThis); 2753 ID.AddInteger(ConstThis); 2754 ID.AddInteger(VolatileThis); 2755 2756 void *InsertPoint; 2757 SpecialMemberOverloadResult *Result = 2758 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint); 2759 2760 // This was already cached 2761 if (Result) 2762 return Result; 2763 2764 Result = BumpAlloc.Allocate<SpecialMemberOverloadResult>(); 2765 Result = new (Result) SpecialMemberOverloadResult(ID); 2766 SpecialMemberCache.InsertNode(Result, InsertPoint); 2767 2768 if (SM == CXXDestructor) { 2769 if (RD->needsImplicitDestructor()) 2770 DeclareImplicitDestructor(RD); 2771 CXXDestructorDecl *DD = RD->getDestructor(); 2772 assert(DD && "record without a destructor"); 2773 Result->setMethod(DD); 2774 Result->setKind(DD->isDeleted() ? 2775 SpecialMemberOverloadResult::NoMemberOrDeleted : 2776 SpecialMemberOverloadResult::Success); 2777 return Result; 2778 } 2779 2780 // Prepare for overload resolution. Here we construct a synthetic argument 2781 // if necessary and make sure that implicit functions are declared. 2782 CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD)); 2783 DeclarationName Name; 2784 Expr *Arg = nullptr; 2785 unsigned NumArgs; 2786 2787 QualType ArgType = CanTy; 2788 ExprValueKind VK = VK_LValue; 2789 2790 if (SM == CXXDefaultConstructor) { 2791 Name = Context.DeclarationNames.getCXXConstructorName(CanTy); 2792 NumArgs = 0; 2793 if (RD->needsImplicitDefaultConstructor()) 2794 DeclareImplicitDefaultConstructor(RD); 2795 } else { 2796 if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) { 2797 Name = Context.DeclarationNames.getCXXConstructorName(CanTy); 2798 if (RD->needsImplicitCopyConstructor()) 2799 DeclareImplicitCopyConstructor(RD); 2800 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor()) 2801 DeclareImplicitMoveConstructor(RD); 2802 } else { 2803 Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal); 2804 if (RD->needsImplicitCopyAssignment()) 2805 DeclareImplicitCopyAssignment(RD); 2806 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment()) 2807 DeclareImplicitMoveAssignment(RD); 2808 } 2809 2810 if (ConstArg) 2811 ArgType.addConst(); 2812 if (VolatileArg) 2813 ArgType.addVolatile(); 2814 2815 // This isn't /really/ specified by the standard, but it's implied 2816 // we should be working from an RValue in the case of move to ensure 2817 // that we prefer to bind to rvalue references, and an LValue in the 2818 // case of copy to ensure we don't bind to rvalue references. 2819 // Possibly an XValue is actually correct in the case of move, but 2820 // there is no semantic difference for class types in this restricted 2821 // case. 2822 if (SM == CXXCopyConstructor || SM == CXXCopyAssignment) 2823 VK = VK_LValue; 2824 else 2825 VK = VK_RValue; 2826 } 2827 2828 OpaqueValueExpr FakeArg(SourceLocation(), ArgType, VK); 2829 2830 if (SM != CXXDefaultConstructor) { 2831 NumArgs = 1; 2832 Arg = &FakeArg; 2833 } 2834 2835 // Create the object argument 2836 QualType ThisTy = CanTy; 2837 if (ConstThis) 2838 ThisTy.addConst(); 2839 if (VolatileThis) 2840 ThisTy.addVolatile(); 2841 Expr::Classification Classification = 2842 OpaqueValueExpr(SourceLocation(), ThisTy, 2843 RValueThis ? VK_RValue : VK_LValue).Classify(Context); 2844 2845 // Now we perform lookup on the name we computed earlier and do overload 2846 // resolution. Lookup is only performed directly into the class since there 2847 // will always be a (possibly implicit) declaration to shadow any others. 2848 OverloadCandidateSet OCS(RD->getLocation(), OverloadCandidateSet::CSK_Normal); 2849 DeclContext::lookup_result R = RD->lookup(Name); 2850 2851 if (R.empty()) { 2852 // We might have no default constructor because we have a lambda's closure 2853 // type, rather than because there's some other declared constructor. 2854 // Every class has a copy/move constructor, copy/move assignment, and 2855 // destructor. 2856 assert(SM == CXXDefaultConstructor && 2857 "lookup for a constructor or assignment operator was empty"); 2858 Result->setMethod(nullptr); 2859 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 2860 return Result; 2861 } 2862 2863 // Copy the candidates as our processing of them may load new declarations 2864 // from an external source and invalidate lookup_result. 2865 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end()); 2866 2867 for (auto *Cand : Candidates) { 2868 if (Cand->isInvalidDecl()) 2869 continue; 2870 2871 if (UsingShadowDecl *U = dyn_cast<UsingShadowDecl>(Cand)) { 2872 // FIXME: [namespace.udecl]p15 says that we should only consider a 2873 // using declaration here if it does not match a declaration in the 2874 // derived class. We do not implement this correctly in other cases 2875 // either. 2876 Cand = U->getTargetDecl(); 2877 2878 if (Cand->isInvalidDecl()) 2879 continue; 2880 } 2881 2882 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand)) { 2883 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) 2884 AddMethodCandidate(M, DeclAccessPair::make(M, AS_public), RD, ThisTy, 2885 Classification, llvm::makeArrayRef(&Arg, NumArgs), 2886 OCS, true); 2887 else 2888 AddOverloadCandidate(M, DeclAccessPair::make(M, AS_public), 2889 llvm::makeArrayRef(&Arg, NumArgs), OCS, true); 2890 } else if (FunctionTemplateDecl *Tmpl = 2891 dyn_cast<FunctionTemplateDecl>(Cand)) { 2892 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) 2893 AddMethodTemplateCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public), 2894 RD, nullptr, ThisTy, Classification, 2895 llvm::makeArrayRef(&Arg, NumArgs), 2896 OCS, true); 2897 else 2898 AddTemplateOverloadCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public), 2899 nullptr, llvm::makeArrayRef(&Arg, NumArgs), 2900 OCS, true); 2901 } else { 2902 assert(isa<UsingDecl>(Cand) && "illegal Kind of operator = Decl"); 2903 } 2904 } 2905 2906 OverloadCandidateSet::iterator Best; 2907 switch (OCS.BestViableFunction(*this, SourceLocation(), Best)) { 2908 case OR_Success: 2909 Result->setMethod(cast<CXXMethodDecl>(Best->Function)); 2910 Result->setKind(SpecialMemberOverloadResult::Success); 2911 break; 2912 2913 case OR_Deleted: 2914 Result->setMethod(cast<CXXMethodDecl>(Best->Function)); 2915 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 2916 break; 2917 2918 case OR_Ambiguous: 2919 Result->setMethod(nullptr); 2920 Result->setKind(SpecialMemberOverloadResult::Ambiguous); 2921 break; 2922 2923 case OR_No_Viable_Function: 2924 Result->setMethod(nullptr); 2925 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 2926 break; 2927 } 2928 2929 return Result; 2930} 2931 2932/// \brief Look up the default constructor for the given class. 2933CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) { 2934 SpecialMemberOverloadResult *Result = 2935 LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false, 2936 false, false); 2937 2938 return cast_or_null<CXXConstructorDecl>(Result->getMethod()); 2939} 2940 2941/// \brief Look up the copying constructor for the given class. 2942CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class, 2943 unsigned Quals) { 2944 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 2945 "non-const, non-volatile qualifiers for copy ctor arg"); 2946 SpecialMemberOverloadResult *Result = 2947 LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const, 2948 Quals & Qualifiers::Volatile, false, false, false); 2949 2950 return cast_or_null<CXXConstructorDecl>(Result->getMethod()); 2951} 2952 2953/// \brief Look up the moving constructor for the given class. 2954CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class, 2955 unsigned Quals) { 2956 SpecialMemberOverloadResult *Result = 2957 LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const, 2958 Quals & Qualifiers::Volatile, false, false, false); 2959 2960 return cast_or_null<CXXConstructorDecl>(Result->getMethod()); 2961} 2962 2963/// \brief Look up the constructors for the given class. 2964DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) { 2965 // If the implicit constructors have not yet been declared, do so now. 2966 if (CanDeclareSpecialMemberFunction(Class)) { 2967 if (Class->needsImplicitDefaultConstructor()) 2968 DeclareImplicitDefaultConstructor(Class); 2969 if (Class->needsImplicitCopyConstructor()) 2970 DeclareImplicitCopyConstructor(Class); 2971 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor()) 2972 DeclareImplicitMoveConstructor(Class); 2973 } 2974 2975 CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class)); 2976 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T); 2977 return Class->lookup(Name); 2978} 2979 2980/// \brief Look up the copying assignment operator for the given class. 2981CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class, 2982 unsigned Quals, bool RValueThis, 2983 unsigned ThisQuals) { 2984 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 2985 "non-const, non-volatile qualifiers for copy assignment arg"); 2986 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 2987 "non-const, non-volatile qualifiers for copy assignment this"); 2988 SpecialMemberOverloadResult *Result = 2989 LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const, 2990 Quals & Qualifiers::Volatile, RValueThis, 2991 ThisQuals & Qualifiers::Const, 2992 ThisQuals & Qualifiers::Volatile); 2993 2994 return Result->getMethod(); 2995} 2996 2997/// \brief Look up the moving assignment operator for the given class. 2998CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class, 2999 unsigned Quals, 3000 bool RValueThis, 3001 unsigned ThisQuals) { 3002 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 3003 "non-const, non-volatile qualifiers for copy assignment this"); 3004 SpecialMemberOverloadResult *Result = 3005 LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const, 3006 Quals & Qualifiers::Volatile, RValueThis, 3007 ThisQuals & Qualifiers::Const, 3008 ThisQuals & Qualifiers::Volatile); 3009 3010 return Result->getMethod(); 3011} 3012 3013/// \brief Look for the destructor of the given class. 3014/// 3015/// During semantic analysis, this routine should be used in lieu of 3016/// CXXRecordDecl::getDestructor(). 3017/// 3018/// \returns The destructor for this class. 3019CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) { 3020 return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor, 3021 false, false, false, 3022 false, false)->getMethod()); 3023} 3024 3025/// LookupLiteralOperator - Determine which literal operator should be used for 3026/// a user-defined literal, per C++11 [lex.ext]. 3027/// 3028/// Normal overload resolution is not used to select which literal operator to 3029/// call for a user-defined literal. Look up the provided literal operator name, 3030/// and filter the results to the appropriate set for the given argument types. 3031Sema::LiteralOperatorLookupResult 3032Sema::LookupLiteralOperator(Scope *S, LookupResult &R, 3033 ArrayRef<QualType> ArgTys, 3034 bool AllowRaw, bool AllowTemplate, 3035 bool AllowStringTemplate) { 3036 LookupName(R, S); 3037 assert(R.getResultKind() != LookupResult::Ambiguous && 3038 "literal operator lookup can't be ambiguous"); 3039 3040 // Filter the lookup results appropriately. 3041 LookupResult::Filter F = R.makeFilter(); 3042 3043 bool FoundRaw = false; 3044 bool FoundTemplate = false; 3045 bool FoundStringTemplate = false; 3046 bool FoundExactMatch = false; 3047 3048 while (F.hasNext()) { 3049 Decl *D = F.next(); 3050 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D)) 3051 D = USD->getTargetDecl(); 3052 3053 // If the declaration we found is invalid, skip it. 3054 if (D->isInvalidDecl()) { 3055 F.erase(); 3056 continue; 3057 } 3058 3059 bool IsRaw = false; 3060 bool IsTemplate = false; 3061 bool IsStringTemplate = false; 3062 bool IsExactMatch = false; 3063 3064 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3065 if (FD->getNumParams() == 1 && 3066 FD->getParamDecl(0)->getType()->getAs<PointerType>()) 3067 IsRaw = true; 3068 else if (FD->getNumParams() == ArgTys.size()) { 3069 IsExactMatch = true; 3070 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) { 3071 QualType ParamTy = FD->getParamDecl(ArgIdx)->getType(); 3072 if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) { 3073 IsExactMatch = false; 3074 break; 3075 } 3076 } 3077 } 3078 } 3079 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) { 3080 TemplateParameterList *Params = FD->getTemplateParameters(); 3081 if (Params->size() == 1) 3082 IsTemplate = true; 3083 else 3084 IsStringTemplate = true; 3085 } 3086 3087 if (IsExactMatch) { 3088 FoundExactMatch = true; 3089 AllowRaw = false; 3090 AllowTemplate = false; 3091 AllowStringTemplate = false; 3092 if (FoundRaw || FoundTemplate || FoundStringTemplate) { 3093 // Go through again and remove the raw and template decls we've 3094 // already found. 3095 F.restart(); 3096 FoundRaw = FoundTemplate = FoundStringTemplate = false; 3097 } 3098 } else if (AllowRaw && IsRaw) { 3099 FoundRaw = true; 3100 } else if (AllowTemplate && IsTemplate) { 3101 FoundTemplate = true; 3102 } else if (AllowStringTemplate && IsStringTemplate) { 3103 FoundStringTemplate = true; 3104 } else { 3105 F.erase(); 3106 } 3107 } 3108 3109 F.done(); 3110 3111 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching 3112 // parameter type, that is used in preference to a raw literal operator 3113 // or literal operator template. 3114 if (FoundExactMatch) 3115 return LOLR_Cooked; 3116 3117 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal 3118 // operator template, but not both. 3119 if (FoundRaw && FoundTemplate) { 3120 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName(); 3121 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 3122 NoteOverloadCandidate((*I)->getUnderlyingDecl()->getAsFunction()); 3123 return LOLR_Error; 3124 } 3125 3126 if (FoundRaw) 3127 return LOLR_Raw; 3128 3129 if (FoundTemplate) 3130 return LOLR_Template; 3131 3132 if (FoundStringTemplate) 3133 return LOLR_StringTemplate; 3134 3135 // Didn't find anything we could use. 3136 Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator) 3137 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0] 3138 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw 3139 << (AllowTemplate || AllowStringTemplate); 3140 return LOLR_Error; 3141} 3142 3143void ADLResult::insert(NamedDecl *New) { 3144 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())]; 3145 3146 // If we haven't yet seen a decl for this key, or the last decl 3147 // was exactly this one, we're done. 3148 if (Old == nullptr || Old == New) { 3149 Old = New; 3150 return; 3151 } 3152 3153 // Otherwise, decide which is a more recent redeclaration. 3154 FunctionDecl *OldFD = Old->getAsFunction(); 3155 FunctionDecl *NewFD = New->getAsFunction(); 3156 3157 FunctionDecl *Cursor = NewFD; 3158 while (true) { 3159 Cursor = Cursor->getPreviousDecl(); 3160 3161 // If we got to the end without finding OldFD, OldFD is the newer 3162 // declaration; leave things as they are. 3163 if (!Cursor) return; 3164 3165 // If we do find OldFD, then NewFD is newer. 3166 if (Cursor == OldFD) break; 3167 3168 // Otherwise, keep looking. 3169 } 3170 3171 Old = New; 3172} 3173 3174void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc, 3175 ArrayRef<Expr *> Args, ADLResult &Result) { 3176 // Find all of the associated namespaces and classes based on the 3177 // arguments we have. 3178 AssociatedNamespaceSet AssociatedNamespaces; 3179 AssociatedClassSet AssociatedClasses; 3180 FindAssociatedClassesAndNamespaces(Loc, Args, 3181 AssociatedNamespaces, 3182 AssociatedClasses); 3183 3184 // C++ [basic.lookup.argdep]p3: 3185 // Let X be the lookup set produced by unqualified lookup (3.4.1) 3186 // and let Y be the lookup set produced by argument dependent 3187 // lookup (defined as follows). If X contains [...] then Y is 3188 // empty. Otherwise Y is the set of declarations found in the 3189 // namespaces associated with the argument types as described 3190 // below. The set of declarations found by the lookup of the name 3191 // is the union of X and Y. 3192 // 3193 // Here, we compute Y and add its members to the overloaded 3194 // candidate set. 3195 for (auto *NS : AssociatedNamespaces) { 3196 // When considering an associated namespace, the lookup is the 3197 // same as the lookup performed when the associated namespace is 3198 // used as a qualifier (3.4.3.2) except that: 3199 // 3200 // -- Any using-directives in the associated namespace are 3201 // ignored. 3202 // 3203 // -- Any namespace-scope friend functions declared in 3204 // associated classes are visible within their respective 3205 // namespaces even if they are not visible during an ordinary 3206 // lookup (11.4). 3207 DeclContext::lookup_result R = NS->lookup(Name); 3208 for (auto *D : R) { 3209 // If the only declaration here is an ordinary friend, consider 3210 // it only if it was declared in an associated classes. 3211 if ((D->getIdentifierNamespace() & Decl::IDNS_Ordinary) == 0) { 3212 // If it's neither ordinarily visible nor a friend, we can't find it. 3213 if ((D->getIdentifierNamespace() & Decl::IDNS_OrdinaryFriend) == 0) 3214 continue; 3215 3216 bool DeclaredInAssociatedClass = false; 3217 for (Decl *DI = D; DI; DI = DI->getPreviousDecl()) { 3218 DeclContext *LexDC = DI->getLexicalDeclContext(); 3219 if (isa<CXXRecordDecl>(LexDC) && 3220 AssociatedClasses.count(cast<CXXRecordDecl>(LexDC)) && 3221 isVisible(cast<NamedDecl>(DI))) { 3222 DeclaredInAssociatedClass = true; 3223 break; 3224 } 3225 } 3226 if (!DeclaredInAssociatedClass) 3227 continue; 3228 } 3229 3230 if (isa<UsingShadowDecl>(D)) 3231 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3232 3233 if (!isa<FunctionDecl>(D) && !isa<FunctionTemplateDecl>(D)) 3234 continue; 3235 3236 if (!isVisible(D) && !(D = findAcceptableDecl(*this, D))) 3237 continue; 3238 3239 Result.insert(D); 3240 } 3241 } 3242} 3243 3244//---------------------------------------------------------------------------- 3245// Search for all visible declarations. 3246//---------------------------------------------------------------------------- 3247VisibleDeclConsumer::~VisibleDeclConsumer() { } 3248 3249bool VisibleDeclConsumer::includeHiddenDecls() const { return false; } 3250 3251namespace { 3252 3253class ShadowContextRAII; 3254 3255class VisibleDeclsRecord { 3256public: 3257 /// \brief An entry in the shadow map, which is optimized to store a 3258 /// single declaration (the common case) but can also store a list 3259 /// of declarations. 3260 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry; 3261 3262private: 3263 /// \brief A mapping from declaration names to the declarations that have 3264 /// this name within a particular scope. 3265 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap; 3266 3267 /// \brief A list of shadow maps, which is used to model name hiding. 3268 std::list<ShadowMap> ShadowMaps; 3269 3270 /// \brief The declaration contexts we have already visited. 3271 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts; 3272 3273 friend class ShadowContextRAII; 3274 3275public: 3276 /// \brief Determine whether we have already visited this context 3277 /// (and, if not, note that we are going to visit that context now). 3278 bool visitedContext(DeclContext *Ctx) { 3279 return !VisitedContexts.insert(Ctx).second; 3280 } 3281 3282 bool alreadyVisitedContext(DeclContext *Ctx) { 3283 return VisitedContexts.count(Ctx); 3284 } 3285 3286 /// \brief Determine whether the given declaration is hidden in the 3287 /// current scope. 3288 /// 3289 /// \returns the declaration that hides the given declaration, or 3290 /// NULL if no such declaration exists. 3291 NamedDecl *checkHidden(NamedDecl *ND); 3292 3293 /// \brief Add a declaration to the current shadow map. 3294 void add(NamedDecl *ND) { 3295 ShadowMaps.back()[ND->getDeclName()].push_back(ND); 3296 } 3297}; 3298 3299/// \brief RAII object that records when we've entered a shadow context. 3300class ShadowContextRAII { 3301 VisibleDeclsRecord &Visible; 3302 3303 typedef VisibleDeclsRecord::ShadowMap ShadowMap; 3304 3305public: 3306 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) { 3307 Visible.ShadowMaps.emplace_back(); 3308 } 3309 3310 ~ShadowContextRAII() { 3311 Visible.ShadowMaps.pop_back(); 3312 } 3313}; 3314 3315} // end anonymous namespace 3316 3317NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) { 3318 unsigned IDNS = ND->getIdentifierNamespace(); 3319 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin(); 3320 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend(); 3321 SM != SMEnd; ++SM) { 3322 ShadowMap::iterator Pos = SM->find(ND->getDeclName()); 3323 if (Pos == SM->end()) 3324 continue; 3325 3326 for (auto *D : Pos->second) { 3327 // A tag declaration does not hide a non-tag declaration. 3328 if (D->hasTagIdentifierNamespace() && 3329 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary | 3330 Decl::IDNS_ObjCProtocol))) 3331 continue; 3332 3333 // Protocols are in distinct namespaces from everything else. 3334 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol) 3335 || (IDNS & Decl::IDNS_ObjCProtocol)) && 3336 D->getIdentifierNamespace() != IDNS) 3337 continue; 3338 3339 // Functions and function templates in the same scope overload 3340 // rather than hide. FIXME: Look for hiding based on function 3341 // signatures! 3342 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() && 3343 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() && 3344 SM == ShadowMaps.rbegin()) 3345 continue; 3346 3347 // We've found a declaration that hides this one. 3348 return D; 3349 } 3350 } 3351 3352 return nullptr; 3353} 3354 3355static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result, 3356 bool QualifiedNameLookup, 3357 bool InBaseClass, 3358 VisibleDeclConsumer &Consumer, 3359 VisibleDeclsRecord &Visited) { 3360 if (!Ctx) 3361 return; 3362 3363 // Make sure we don't visit the same context twice. 3364 if (Visited.visitedContext(Ctx->getPrimaryContext())) 3365 return; 3366 3367 // Outside C++, lookup results for the TU live on identifiers. 3368 if (isa<TranslationUnitDecl>(Ctx) && 3369 !Result.getSema().getLangOpts().CPlusPlus) { 3370 auto &S = Result.getSema(); 3371 auto &Idents = S.Context.Idents; 3372 3373 // Ensure all external identifiers are in the identifier table. 3374 if (IdentifierInfoLookup *External = Idents.getExternalIdentifierLookup()) { 3375 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers()); 3376 for (StringRef Name = Iter->Next(); !Name.empty(); Name = Iter->Next()) 3377 Idents.get(Name); 3378 } 3379 3380 // Walk all lookup results in the TU for each identifier. 3381 for (const auto &Ident : Idents) { 3382 for (auto I = S.IdResolver.begin(Ident.getValue()), 3383 E = S.IdResolver.end(); 3384 I != E; ++I) { 3385 if (S.IdResolver.isDeclInScope(*I, Ctx)) { 3386 if (NamedDecl *ND = Result.getAcceptableDecl(*I)) { 3387 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass); 3388 Visited.add(ND); 3389 } 3390 } 3391 } 3392 } 3393 3394 return; 3395 } 3396 3397 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx)) 3398 Result.getSema().ForceDeclarationOfImplicitMembers(Class); 3399 3400 // Enumerate all of the results in this context. 3401 for (DeclContextLookupResult R : Ctx->lookups()) { 3402 for (auto *D : R) { 3403 if (auto *ND = Result.getAcceptableDecl(D)) { 3404 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass); 3405 Visited.add(ND); 3406 } 3407 } 3408 } 3409 3410 // Traverse using directives for qualified name lookup. 3411 if (QualifiedNameLookup) { 3412 ShadowContextRAII Shadow(Visited); 3413 for (auto I : Ctx->using_directives()) { 3414 LookupVisibleDecls(I->getNominatedNamespace(), Result, 3415 QualifiedNameLookup, InBaseClass, Consumer, Visited); 3416 } 3417 } 3418 3419 // Traverse the contexts of inherited C++ classes. 3420 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) { 3421 if (!Record->hasDefinition()) 3422 return; 3423 3424 for (const auto &B : Record->bases()) { 3425 QualType BaseType = B.getType(); 3426 3427 // Don't look into dependent bases, because name lookup can't look 3428 // there anyway. 3429 if (BaseType->isDependentType()) 3430 continue; 3431 3432 const RecordType *Record = BaseType->getAs<RecordType>(); 3433 if (!Record) 3434 continue; 3435 3436 // FIXME: It would be nice to be able to determine whether referencing 3437 // a particular member would be ambiguous. For example, given 3438 // 3439 // struct A { int member; }; 3440 // struct B { int member; }; 3441 // struct C : A, B { }; 3442 // 3443 // void f(C *c) { c->### } 3444 // 3445 // accessing 'member' would result in an ambiguity. However, we 3446 // could be smart enough to qualify the member with the base 3447 // class, e.g., 3448 // 3449 // c->B::member 3450 // 3451 // or 3452 // 3453 // c->A::member 3454 3455 // Find results in this base class (and its bases). 3456 ShadowContextRAII Shadow(Visited); 3457 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup, 3458 true, Consumer, Visited); 3459 } 3460 } 3461 3462 // Traverse the contexts of Objective-C classes. 3463 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) { 3464 // Traverse categories. 3465 for (auto *Cat : IFace->visible_categories()) { 3466 ShadowContextRAII Shadow(Visited); 3467 LookupVisibleDecls(Cat, Result, QualifiedNameLookup, false, 3468 Consumer, Visited); 3469 } 3470 3471 // Traverse protocols. 3472 for (auto *I : IFace->all_referenced_protocols()) { 3473 ShadowContextRAII Shadow(Visited); 3474 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer, 3475 Visited); 3476 } 3477 3478 // Traverse the superclass. 3479 if (IFace->getSuperClass()) { 3480 ShadowContextRAII Shadow(Visited); 3481 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup, 3482 true, Consumer, Visited); 3483 } 3484 3485 // If there is an implementation, traverse it. We do this to find 3486 // synthesized ivars. 3487 if (IFace->getImplementation()) { 3488 ShadowContextRAII Shadow(Visited); 3489 LookupVisibleDecls(IFace->getImplementation(), Result, 3490 QualifiedNameLookup, InBaseClass, Consumer, Visited); 3491 } 3492 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) { 3493 for (auto *I : Protocol->protocols()) { 3494 ShadowContextRAII Shadow(Visited); 3495 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer, 3496 Visited); 3497 } 3498 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) { 3499 for (auto *I : Category->protocols()) { 3500 ShadowContextRAII Shadow(Visited); 3501 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer, 3502 Visited); 3503 } 3504 3505 // If there is an implementation, traverse it. 3506 if (Category->getImplementation()) { 3507 ShadowContextRAII Shadow(Visited); 3508 LookupVisibleDecls(Category->getImplementation(), Result, 3509 QualifiedNameLookup, true, Consumer, Visited); 3510 } 3511 } 3512} 3513 3514static void LookupVisibleDecls(Scope *S, LookupResult &Result, 3515 UnqualUsingDirectiveSet &UDirs, 3516 VisibleDeclConsumer &Consumer, 3517 VisibleDeclsRecord &Visited) { 3518 if (!S) 3519 return; 3520 3521 if (!S->getEntity() || 3522 (!S->getParent() && 3523 !Visited.alreadyVisitedContext(S->getEntity())) || 3524 (S->getEntity())->isFunctionOrMethod()) { 3525 FindLocalExternScope FindLocals(Result); 3526 // Walk through the declarations in this Scope. 3527 for (auto *D : S->decls()) { 3528 if (NamedDecl *ND = dyn_cast<NamedDecl>(D)) 3529 if ((ND = Result.getAcceptableDecl(ND))) { 3530 Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false); 3531 Visited.add(ND); 3532 } 3533 } 3534 } 3535 3536 // FIXME: C++ [temp.local]p8 3537 DeclContext *Entity = nullptr; 3538 if (S->getEntity()) { 3539 // Look into this scope's declaration context, along with any of its 3540 // parent lookup contexts (e.g., enclosing classes), up to the point 3541 // where we hit the context stored in the next outer scope. 3542 Entity = S->getEntity(); 3543 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME 3544 3545 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx); 3546 Ctx = Ctx->getLookupParent()) { 3547 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 3548 if (Method->isInstanceMethod()) { 3549 // For instance methods, look for ivars in the method's interface. 3550 LookupResult IvarResult(Result.getSema(), Result.getLookupName(), 3551 Result.getNameLoc(), Sema::LookupMemberName); 3552 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) { 3553 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false, 3554 /*InBaseClass=*/false, Consumer, Visited); 3555 } 3556 } 3557 3558 // We've already performed all of the name lookup that we need 3559 // to for Objective-C methods; the next context will be the 3560 // outer scope. 3561 break; 3562 } 3563 3564 if (Ctx->isFunctionOrMethod()) 3565 continue; 3566 3567 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false, 3568 /*InBaseClass=*/false, Consumer, Visited); 3569 } 3570 } else if (!S->getParent()) { 3571 // Look into the translation unit scope. We walk through the translation 3572 // unit's declaration context, because the Scope itself won't have all of 3573 // the declarations if we loaded a precompiled header. 3574 // FIXME: We would like the translation unit's Scope object to point to the 3575 // translation unit, so we don't need this special "if" branch. However, 3576 // doing so would force the normal C++ name-lookup code to look into the 3577 // translation unit decl when the IdentifierInfo chains would suffice. 3578 // Once we fix that problem (which is part of a more general "don't look 3579 // in DeclContexts unless we have to" optimization), we can eliminate this. 3580 Entity = Result.getSema().Context.getTranslationUnitDecl(); 3581 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false, 3582 /*InBaseClass=*/false, Consumer, Visited); 3583 } 3584 3585 if (Entity) { 3586 // Lookup visible declarations in any namespaces found by using 3587 // directives. 3588 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity)) 3589 LookupVisibleDecls(const_cast<DeclContext *>(UUE.getNominatedNamespace()), 3590 Result, /*QualifiedNameLookup=*/false, 3591 /*InBaseClass=*/false, Consumer, Visited); 3592 } 3593 3594 // Lookup names in the parent scope. 3595 ShadowContextRAII Shadow(Visited); 3596 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited); 3597} 3598 3599void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind, 3600 VisibleDeclConsumer &Consumer, 3601 bool IncludeGlobalScope) { 3602 // Determine the set of using directives available during 3603 // unqualified name lookup. 3604 Scope *Initial = S; 3605 UnqualUsingDirectiveSet UDirs; 3606 if (getLangOpts().CPlusPlus) { 3607 // Find the first namespace or translation-unit scope. 3608 while (S && !isNamespaceOrTranslationUnitScope(S)) 3609 S = S->getParent(); 3610 3611 UDirs.visitScopeChain(Initial, S); 3612 } 3613 UDirs.done(); 3614 3615 // Look for visible declarations. 3616 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 3617 Result.setAllowHidden(Consumer.includeHiddenDecls()); 3618 VisibleDeclsRecord Visited; 3619 if (!IncludeGlobalScope) 3620 Visited.visitedContext(Context.getTranslationUnitDecl()); 3621 ShadowContextRAII Shadow(Visited); 3622 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited); 3623} 3624 3625void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind, 3626 VisibleDeclConsumer &Consumer, 3627 bool IncludeGlobalScope) { 3628 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); 3629 Result.setAllowHidden(Consumer.includeHiddenDecls()); 3630 VisibleDeclsRecord Visited; 3631 if (!IncludeGlobalScope) 3632 Visited.visitedContext(Context.getTranslationUnitDecl()); 3633 ShadowContextRAII Shadow(Visited); 3634 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true, 3635 /*InBaseClass=*/false, Consumer, Visited); 3636} 3637 3638/// LookupOrCreateLabel - Do a name lookup of a label with the specified name. 3639/// If GnuLabelLoc is a valid source location, then this is a definition 3640/// of an __label__ label name, otherwise it is a normal label definition 3641/// or use. 3642LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc, 3643 SourceLocation GnuLabelLoc) { 3644 // Do a lookup to see if we have a label with this name already. 3645 NamedDecl *Res = nullptr; 3646 3647 if (GnuLabelLoc.isValid()) { 3648 // Local label definitions always shadow existing labels. 3649 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc); 3650 Scope *S = CurScope; 3651 PushOnScopeChains(Res, S, true); 3652 return cast<LabelDecl>(Res); 3653 } 3654 3655 // Not a GNU local label. 3656 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration); 3657 // If we found a label, check to see if it is in the same context as us. 3658 // When in a Block, we don't want to reuse a label in an enclosing function. 3659 if (Res && Res->getDeclContext() != CurContext) 3660 Res = nullptr; 3661 if (!Res) { 3662 // If not forward referenced or defined already, create the backing decl. 3663 Res = LabelDecl::Create(Context, CurContext, Loc, II); 3664 Scope *S = CurScope->getFnParent(); 3665 assert(S && "Not in a function?"); 3666 PushOnScopeChains(Res, S, true); 3667 } 3668 return cast<LabelDecl>(Res); 3669} 3670 3671//===----------------------------------------------------------------------===// 3672// Typo correction 3673//===----------------------------------------------------------------------===// 3674 3675static bool isCandidateViable(CorrectionCandidateCallback &CCC, 3676 TypoCorrection &Candidate) { 3677 Candidate.setCallbackDistance(CCC.RankCandidate(Candidate)); 3678 return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance; 3679} 3680 3681static void LookupPotentialTypoResult(Sema &SemaRef, 3682 LookupResult &Res, 3683 IdentifierInfo *Name, 3684 Scope *S, CXXScopeSpec *SS, 3685 DeclContext *MemberContext, 3686 bool EnteringContext, 3687 bool isObjCIvarLookup, 3688 bool FindHidden); 3689 3690/// \brief Check whether the declarations found for a typo correction are 3691/// visible, and if none of them are, convert the correction to an 'import 3692/// a module' correction. 3693static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) { 3694 if (TC.begin() == TC.end()) 3695 return; 3696 3697 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end(); 3698 3699 for (/**/; DI != DE; ++DI) 3700 if (!LookupResult::isVisible(SemaRef, *DI)) 3701 break; 3702 // Nothing to do if all decls are visible. 3703 if (DI == DE) 3704 return; 3705 3706 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI); 3707 bool AnyVisibleDecls = !NewDecls.empty(); 3708 3709 for (/**/; DI != DE; ++DI) { 3710 NamedDecl *VisibleDecl = *DI; 3711 if (!LookupResult::isVisible(SemaRef, *DI)) 3712 VisibleDecl = findAcceptableDecl(SemaRef, *DI); 3713 3714 if (VisibleDecl) { 3715 if (!AnyVisibleDecls) { 3716 // Found a visible decl, discard all hidden ones. 3717 AnyVisibleDecls = true; 3718 NewDecls.clear(); 3719 } 3720 NewDecls.push_back(VisibleDecl); 3721 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate()) 3722 NewDecls.push_back(*DI); 3723 } 3724 3725 if (NewDecls.empty()) 3726 TC = TypoCorrection(); 3727 else { 3728 TC.setCorrectionDecls(NewDecls); 3729 TC.setRequiresImport(!AnyVisibleDecls); 3730 } 3731} 3732 3733// Fill the supplied vector with the IdentifierInfo pointers for each piece of 3734// the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::", 3735// fill the vector with the IdentifierInfo pointers for "foo" and "bar"). 3736static void getNestedNameSpecifierIdentifiers( 3737 NestedNameSpecifier *NNS, 3738 SmallVectorImpl<const IdentifierInfo*> &Identifiers) { 3739 if (NestedNameSpecifier *Prefix = NNS->getPrefix()) 3740 getNestedNameSpecifierIdentifiers(Prefix, Identifiers); 3741 else 3742 Identifiers.clear(); 3743 3744 const IdentifierInfo *II = nullptr; 3745 3746 switch (NNS->getKind()) { 3747 case NestedNameSpecifier::Identifier: 3748 II = NNS->getAsIdentifier(); 3749 break; 3750 3751 case NestedNameSpecifier::Namespace: 3752 if (NNS->getAsNamespace()->isAnonymousNamespace()) 3753 return; 3754 II = NNS->getAsNamespace()->getIdentifier(); 3755 break; 3756 3757 case NestedNameSpecifier::NamespaceAlias: 3758 II = NNS->getAsNamespaceAlias()->getIdentifier(); 3759 break; 3760 3761 case NestedNameSpecifier::TypeSpecWithTemplate: 3762 case NestedNameSpecifier::TypeSpec: 3763 II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier(); 3764 break; 3765 3766 case NestedNameSpecifier::Global: 3767 case NestedNameSpecifier::Super: 3768 return; 3769 } 3770 3771 if (II) 3772 Identifiers.push_back(II); 3773} 3774 3775void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding, 3776 DeclContext *Ctx, bool InBaseClass) { 3777 // Don't consider hidden names for typo correction. 3778 if (Hiding) 3779 return; 3780 3781 // Only consider entities with identifiers for names, ignoring 3782 // special names (constructors, overloaded operators, selectors, 3783 // etc.). 3784 IdentifierInfo *Name = ND->getIdentifier(); 3785 if (!Name) 3786 return; 3787 3788 // Only consider visible declarations and declarations from modules with 3789 // names that exactly match. 3790 if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo && 3791 !findAcceptableDecl(SemaRef, ND)) 3792 return; 3793 3794 FoundName(Name->getName()); 3795} 3796 3797void TypoCorrectionConsumer::FoundName(StringRef Name) { 3798 // Compute the edit distance between the typo and the name of this 3799 // entity, and add the identifier to the list of results. 3800 addName(Name, nullptr); 3801} 3802 3803void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) { 3804 // Compute the edit distance between the typo and this keyword, 3805 // and add the keyword to the list of results. 3806 addName(Keyword, nullptr, nullptr, true); 3807} 3808 3809void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND, 3810 NestedNameSpecifier *NNS, bool isKeyword) { 3811 // Use a simple length-based heuristic to determine the minimum possible 3812 // edit distance. If the minimum isn't good enough, bail out early. 3813 StringRef TypoStr = Typo->getName(); 3814 unsigned MinED = abs((int)Name.size() - (int)TypoStr.size()); 3815 if (MinED && TypoStr.size() / MinED < 3) 3816 return; 3817 3818 // Compute an upper bound on the allowable edit distance, so that the 3819 // edit-distance algorithm can short-circuit. 3820 unsigned UpperBound = (TypoStr.size() + 2) / 3 + 1; 3821 unsigned ED = TypoStr.edit_distance(Name, true, UpperBound); 3822 if (ED >= UpperBound) return; 3823 3824 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED); 3825 if (isKeyword) TC.makeKeyword(); 3826 TC.setCorrectionRange(nullptr, Result.getLookupNameInfo()); 3827 addCorrection(TC); 3828} 3829 3830static const unsigned MaxTypoDistanceResultSets = 5; 3831 3832void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) { 3833 StringRef TypoStr = Typo->getName(); 3834 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName(); 3835 3836 // For very short typos, ignore potential corrections that have a different 3837 // base identifier from the typo or which have a normalized edit distance 3838 // longer than the typo itself. 3839 if (TypoStr.size() < 3 && 3840 (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size())) 3841 return; 3842 3843 // If the correction is resolved but is not viable, ignore it. 3844 if (Correction.isResolved()) { 3845 checkCorrectionVisibility(SemaRef, Correction); 3846 if (!Correction || !isCandidateViable(*CorrectionValidator, Correction)) 3847 return; 3848 } 3849 3850 TypoResultList &CList = 3851 CorrectionResults[Correction.getEditDistance(false)][Name]; 3852 3853 if (!CList.empty() && !CList.back().isResolved()) 3854 CList.pop_back(); 3855 if (NamedDecl *NewND = Correction.getCorrectionDecl()) { 3856 std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts()); 3857 for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end(); 3858 RI != RIEnd; ++RI) { 3859 // If the Correction refers to a decl already in the result list, 3860 // replace the existing result if the string representation of Correction 3861 // comes before the current result alphabetically, then stop as there is 3862 // nothing more to be done to add Correction to the candidate set. 3863 if (RI->getCorrectionDecl() == NewND) { 3864 if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts())) 3865 *RI = Correction; 3866 return; 3867 } 3868 } 3869 } 3870 if (CList.empty() || Correction.isResolved()) 3871 CList.push_back(Correction); 3872 3873 while (CorrectionResults.size() > MaxTypoDistanceResultSets) 3874 CorrectionResults.erase(std::prev(CorrectionResults.end())); 3875} 3876 3877void TypoCorrectionConsumer::addNamespaces( 3878 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) { 3879 SearchNamespaces = true; 3880 3881 for (auto KNPair : KnownNamespaces) 3882 Namespaces.addNameSpecifier(KNPair.first); 3883 3884 bool SSIsTemplate = false; 3885 if (NestedNameSpecifier *NNS = 3886 (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) { 3887 if (const Type *T = NNS->getAsType()) 3888 SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization; 3889 } 3890 // Do not transform this into an iterator-based loop. The loop body can 3891 // trigger the creation of further types (through lazy deserialization) and 3892 // invalide iterators into this list. 3893 auto &Types = SemaRef.getASTContext().getTypes(); 3894 for (unsigned I = 0; I != Types.size(); ++I) { 3895 const auto *TI = Types[I]; 3896 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) { 3897 CD = CD->getCanonicalDecl(); 3898 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() && 3899 !CD->isUnion() && CD->getIdentifier() && 3900 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) && 3901 (CD->isBeingDefined() || CD->isCompleteDefinition())) 3902 Namespaces.addNameSpecifier(CD); 3903 } 3904 } 3905} 3906 3907const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() { 3908 if (++CurrentTCIndex < ValidatedCorrections.size()) 3909 return ValidatedCorrections[CurrentTCIndex]; 3910 3911 CurrentTCIndex = ValidatedCorrections.size(); 3912 while (!CorrectionResults.empty()) { 3913 auto DI = CorrectionResults.begin(); 3914 if (DI->second.empty()) { 3915 CorrectionResults.erase(DI); 3916 continue; 3917 } 3918 3919 auto RI = DI->second.begin(); 3920 if (RI->second.empty()) { 3921 DI->second.erase(RI); 3922 performQualifiedLookups(); 3923 continue; 3924 } 3925 3926 TypoCorrection TC = RI->second.pop_back_val(); 3927 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) { 3928 ValidatedCorrections.push_back(TC); 3929 return ValidatedCorrections[CurrentTCIndex]; 3930 } 3931 } 3932 return ValidatedCorrections[0]; // The empty correction. 3933} 3934 3935bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) { 3936 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo(); 3937 DeclContext *TempMemberContext = MemberContext; 3938 CXXScopeSpec *TempSS = SS.get(); 3939retry_lookup: 3940 LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext, 3941 EnteringContext, 3942 CorrectionValidator->IsObjCIvarLookup, 3943 Name == Typo && !Candidate.WillReplaceSpecifier()); 3944 switch (Result.getResultKind()) { 3945 case LookupResult::NotFound: 3946 case LookupResult::NotFoundInCurrentInstantiation: 3947 case LookupResult::FoundUnresolvedValue: 3948 if (TempSS) { 3949 // Immediately retry the lookup without the given CXXScopeSpec 3950 TempSS = nullptr; 3951 Candidate.WillReplaceSpecifier(true); 3952 goto retry_lookup; 3953 } 3954 if (TempMemberContext) { 3955 if (SS && !TempSS) 3956 TempSS = SS.get(); 3957 TempMemberContext = nullptr; 3958 goto retry_lookup; 3959 } 3960 if (SearchNamespaces) 3961 QualifiedResults.push_back(Candidate); 3962 break; 3963 3964 case LookupResult::Ambiguous: 3965 // We don't deal with ambiguities. 3966 break; 3967 3968 case LookupResult::Found: 3969 case LookupResult::FoundOverloaded: 3970 // Store all of the Decls for overloaded symbols 3971 for (auto *TRD : Result) 3972 Candidate.addCorrectionDecl(TRD); 3973 checkCorrectionVisibility(SemaRef, Candidate); 3974 if (!isCandidateViable(*CorrectionValidator, Candidate)) { 3975 if (SearchNamespaces) 3976 QualifiedResults.push_back(Candidate); 3977 break; 3978 } 3979 Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo()); 3980 return true; 3981 } 3982 return false; 3983} 3984 3985void TypoCorrectionConsumer::performQualifiedLookups() { 3986 unsigned TypoLen = Typo->getName().size(); 3987 for (auto QR : QualifiedResults) { 3988 for (auto NSI : Namespaces) { 3989 DeclContext *Ctx = NSI.DeclCtx; 3990 const Type *NSType = NSI.NameSpecifier->getAsType(); 3991 3992 // If the current NestedNameSpecifier refers to a class and the 3993 // current correction candidate is the name of that class, then skip 3994 // it as it is unlikely a qualified version of the class' constructor 3995 // is an appropriate correction. 3996 if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() : 3997 nullptr) { 3998 if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo()) 3999 continue; 4000 } 4001 4002 TypoCorrection TC(QR); 4003 TC.ClearCorrectionDecls(); 4004 TC.setCorrectionSpecifier(NSI.NameSpecifier); 4005 TC.setQualifierDistance(NSI.EditDistance); 4006 TC.setCallbackDistance(0); // Reset the callback distance 4007 4008 // If the current correction candidate and namespace combination are 4009 // too far away from the original typo based on the normalized edit 4010 // distance, then skip performing a qualified name lookup. 4011 unsigned TmpED = TC.getEditDistance(true); 4012 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED && 4013 TypoLen / TmpED < 3) 4014 continue; 4015 4016 Result.clear(); 4017 Result.setLookupName(QR.getCorrectionAsIdentifierInfo()); 4018 if (!SemaRef.LookupQualifiedName(Result, Ctx)) 4019 continue; 4020 4021 // Any corrections added below will be validated in subsequent 4022 // iterations of the main while() loop over the Consumer's contents. 4023 switch (Result.getResultKind()) { 4024 case LookupResult::Found: 4025 case LookupResult::FoundOverloaded: { 4026 if (SS && SS->isValid()) { 4027 std::string NewQualified = TC.getAsString(SemaRef.getLangOpts()); 4028 std::string OldQualified; 4029 llvm::raw_string_ostream OldOStream(OldQualified); 4030 SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy()); 4031 OldOStream << Typo->getName(); 4032 // If correction candidate would be an identical written qualified 4033 // identifer, then the existing CXXScopeSpec probably included a 4034 // typedef that didn't get accounted for properly. 4035 if (OldOStream.str() == NewQualified) 4036 break; 4037 } 4038 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end(); 4039 TRD != TRDEnd; ++TRD) { 4040 if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(), 4041 NSType ? NSType->getAsCXXRecordDecl() 4042 : nullptr, 4043 TRD.getPair()) == Sema::AR_accessible) 4044 TC.addCorrectionDecl(*TRD); 4045 } 4046 if (TC.isResolved()) { 4047 TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo()); 4048 addCorrection(TC); 4049 } 4050 break; 4051 } 4052 case LookupResult::NotFound: 4053 case LookupResult::NotFoundInCurrentInstantiation: 4054 case LookupResult::Ambiguous: 4055 case LookupResult::FoundUnresolvedValue: 4056 break; 4057 } 4058 } 4059 } 4060 QualifiedResults.clear(); 4061} 4062 4063TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet( 4064 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec) 4065 : Context(Context), CurContextChain(buildContextChain(CurContext)) { 4066 if (NestedNameSpecifier *NNS = 4067 CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) { 4068 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier); 4069 NNS->print(SpecifierOStream, Context.getPrintingPolicy()); 4070 4071 getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers); 4072 } 4073 // Build the list of identifiers that would be used for an absolute 4074 // (from the global context) NestedNameSpecifier referring to the current 4075 // context. 4076 for (DeclContextList::reverse_iterator C = CurContextChain.rbegin(), 4077 CEnd = CurContextChain.rend(); 4078 C != CEnd; ++C) { 4079 if (NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(*C)) 4080 CurContextIdentifiers.push_back(ND->getIdentifier()); 4081 } 4082 4083 // Add the global context as a NestedNameSpecifier 4084 SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()), 4085 NestedNameSpecifier::GlobalSpecifier(Context), 1}; 4086 DistanceMap[1].push_back(SI); 4087} 4088 4089auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain( 4090 DeclContext *Start) -> DeclContextList { 4091 assert(Start && "Building a context chain from a null context"); 4092 DeclContextList Chain; 4093 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr; 4094 DC = DC->getLookupParent()) { 4095 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC); 4096 if (!DC->isInlineNamespace() && !DC->isTransparentContext() && 4097 !(ND && ND->isAnonymousNamespace())) 4098 Chain.push_back(DC->getPrimaryContext()); 4099 } 4100 return Chain; 4101} 4102 4103unsigned 4104TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier( 4105 DeclContextList &DeclChain, NestedNameSpecifier *&NNS) { 4106 unsigned NumSpecifiers = 0; 4107 for (DeclContextList::reverse_iterator C = DeclChain.rbegin(), 4108 CEnd = DeclChain.rend(); 4109 C != CEnd; ++C) { 4110 if (NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(*C)) { 4111 NNS = NestedNameSpecifier::Create(Context, NNS, ND); 4112 ++NumSpecifiers; 4113 } else if (RecordDecl *RD = dyn_cast_or_null<RecordDecl>(*C)) { 4114 NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(), 4115 RD->getTypeForDecl()); 4116 ++NumSpecifiers; 4117 } 4118 } 4119 return NumSpecifiers; 4120} 4121 4122void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier( 4123 DeclContext *Ctx) { 4124 NestedNameSpecifier *NNS = nullptr; 4125 unsigned NumSpecifiers = 0; 4126 DeclContextList NamespaceDeclChain(buildContextChain(Ctx)); 4127 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain); 4128 4129 // Eliminate common elements from the two DeclContext chains. 4130 for (DeclContextList::reverse_iterator C = CurContextChain.rbegin(), 4131 CEnd = CurContextChain.rend(); 4132 C != CEnd && !NamespaceDeclChain.empty() && 4133 NamespaceDeclChain.back() == *C; ++C) { 4134 NamespaceDeclChain.pop_back(); 4135 } 4136 4137 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain 4138 NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS); 4139 4140 // Add an explicit leading '::' specifier if needed. 4141 if (NamespaceDeclChain.empty()) { 4142 // Rebuild the NestedNameSpecifier as a globally-qualified specifier. 4143 NNS = NestedNameSpecifier::GlobalSpecifier(Context); 4144 NumSpecifiers = 4145 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS); 4146 } else if (NamedDecl *ND = 4147 dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) { 4148 IdentifierInfo *Name = ND->getIdentifier(); 4149 bool SameNameSpecifier = false; 4150 if (std::find(CurNameSpecifierIdentifiers.begin(), 4151 CurNameSpecifierIdentifiers.end(), 4152 Name) != CurNameSpecifierIdentifiers.end()) { 4153 std::string NewNameSpecifier; 4154 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier); 4155 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers; 4156 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers); 4157 NNS->print(SpecifierOStream, Context.getPrintingPolicy()); 4158 SpecifierOStream.flush(); 4159 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier; 4160 } 4161 if (SameNameSpecifier || 4162 std::find(CurContextIdentifiers.begin(), CurContextIdentifiers.end(), 4163 Name) != CurContextIdentifiers.end()) { 4164 // Rebuild the NestedNameSpecifier as a globally-qualified specifier. 4165 NNS = NestedNameSpecifier::GlobalSpecifier(Context); 4166 NumSpecifiers = 4167 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS); 4168 } 4169 } 4170 4171 // If the built NestedNameSpecifier would be replacing an existing 4172 // NestedNameSpecifier, use the number of component identifiers that 4173 // would need to be changed as the edit distance instead of the number 4174 // of components in the built NestedNameSpecifier. 4175 if (NNS && !CurNameSpecifierIdentifiers.empty()) { 4176 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers; 4177 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers); 4178 NumSpecifiers = llvm::ComputeEditDistance( 4179 llvm::makeArrayRef(CurNameSpecifierIdentifiers), 4180 llvm::makeArrayRef(NewNameSpecifierIdentifiers)); 4181 } 4182 4183 SpecifierInfo SI = {Ctx, NNS, NumSpecifiers}; 4184 DistanceMap[NumSpecifiers].push_back(SI); 4185} 4186 4187/// \brief Perform name lookup for a possible result for typo correction. 4188static void LookupPotentialTypoResult(Sema &SemaRef, 4189 LookupResult &Res, 4190 IdentifierInfo *Name, 4191 Scope *S, CXXScopeSpec *SS, 4192 DeclContext *MemberContext, 4193 bool EnteringContext, 4194 bool isObjCIvarLookup, 4195 bool FindHidden) { 4196 Res.suppressDiagnostics(); 4197 Res.clear(); 4198 Res.setLookupName(Name); 4199 Res.setAllowHidden(FindHidden); 4200 if (MemberContext) { 4201 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) { 4202 if (isObjCIvarLookup) { 4203 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) { 4204 Res.addDecl(Ivar); 4205 Res.resolveKind(); 4206 return; 4207 } 4208 } 4209 4210 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(Name)) { 4211 Res.addDecl(Prop); 4212 Res.resolveKind(); 4213 return; 4214 } 4215 } 4216 4217 SemaRef.LookupQualifiedName(Res, MemberContext); 4218 return; 4219 } 4220 4221 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false, 4222 EnteringContext); 4223 4224 // Fake ivar lookup; this should really be part of 4225 // LookupParsedName. 4226 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) { 4227 if (Method->isInstanceMethod() && Method->getClassInterface() && 4228 (Res.empty() || 4229 (Res.isSingleResult() && 4230 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) { 4231 if (ObjCIvarDecl *IV 4232 = Method->getClassInterface()->lookupInstanceVariable(Name)) { 4233 Res.addDecl(IV); 4234 Res.resolveKind(); 4235 } 4236 } 4237 } 4238} 4239 4240/// \brief Add keywords to the consumer as possible typo corrections. 4241static void AddKeywordsToConsumer(Sema &SemaRef, 4242 TypoCorrectionConsumer &Consumer, 4243 Scope *S, CorrectionCandidateCallback &CCC, 4244 bool AfterNestedNameSpecifier) { 4245 if (AfterNestedNameSpecifier) { 4246 // For 'X::', we know exactly which keywords can appear next. 4247 Consumer.addKeywordResult("template"); 4248 if (CCC.WantExpressionKeywords) 4249 Consumer.addKeywordResult("operator"); 4250 return; 4251 } 4252 4253 if (CCC.WantObjCSuper) 4254 Consumer.addKeywordResult("super"); 4255 4256 if (CCC.WantTypeSpecifiers) { 4257 // Add type-specifier keywords to the set of results. 4258 static const char *const CTypeSpecs[] = { 4259 "char", "const", "double", "enum", "float", "int", "long", "short", 4260 "signed", "struct", "union", "unsigned", "void", "volatile", 4261 "_Complex", "_Imaginary", 4262 // storage-specifiers as well 4263 "extern", "inline", "static", "typedef" 4264 }; 4265 4266 const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs); 4267 for (unsigned I = 0; I != NumCTypeSpecs; ++I) 4268 Consumer.addKeywordResult(CTypeSpecs[I]); 4269 4270 if (SemaRef.getLangOpts().C99) 4271 Consumer.addKeywordResult("restrict"); 4272 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) 4273 Consumer.addKeywordResult("bool"); 4274 else if (SemaRef.getLangOpts().C99) 4275 Consumer.addKeywordResult("_Bool"); 4276 4277 if (SemaRef.getLangOpts().CPlusPlus) { 4278 Consumer.addKeywordResult("class"); 4279 Consumer.addKeywordResult("typename"); 4280 Consumer.addKeywordResult("wchar_t"); 4281 4282 if (SemaRef.getLangOpts().CPlusPlus11) { 4283 Consumer.addKeywordResult("char16_t"); 4284 Consumer.addKeywordResult("char32_t"); 4285 Consumer.addKeywordResult("constexpr"); 4286 Consumer.addKeywordResult("decltype"); 4287 Consumer.addKeywordResult("thread_local"); 4288 } 4289 } 4290 4291 if (SemaRef.getLangOpts().GNUMode) 4292 Consumer.addKeywordResult("typeof"); 4293 } else if (CCC.WantFunctionLikeCasts) { 4294 static const char *const CastableTypeSpecs[] = { 4295 "char", "double", "float", "int", "long", "short", 4296 "signed", "unsigned", "void" 4297 }; 4298 for (auto *kw : CastableTypeSpecs) 4299 Consumer.addKeywordResult(kw); 4300 } 4301 4302 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) { 4303 Consumer.addKeywordResult("const_cast"); 4304 Consumer.addKeywordResult("dynamic_cast"); 4305 Consumer.addKeywordResult("reinterpret_cast"); 4306 Consumer.addKeywordResult("static_cast"); 4307 } 4308 4309 if (CCC.WantExpressionKeywords) { 4310 Consumer.addKeywordResult("sizeof"); 4311 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) { 4312 Consumer.addKeywordResult("false"); 4313 Consumer.addKeywordResult("true"); 4314 } 4315 4316 if (SemaRef.getLangOpts().CPlusPlus) { 4317 static const char *const CXXExprs[] = { 4318 "delete", "new", "operator", "throw", "typeid" 4319 }; 4320 const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs); 4321 for (unsigned I = 0; I != NumCXXExprs; ++I) 4322 Consumer.addKeywordResult(CXXExprs[I]); 4323 4324 if (isa<CXXMethodDecl>(SemaRef.CurContext) && 4325 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance()) 4326 Consumer.addKeywordResult("this"); 4327 4328 if (SemaRef.getLangOpts().CPlusPlus11) { 4329 Consumer.addKeywordResult("alignof"); 4330 Consumer.addKeywordResult("nullptr"); 4331 } 4332 } 4333 4334 if (SemaRef.getLangOpts().C11) { 4335 // FIXME: We should not suggest _Alignof if the alignof macro 4336 // is present. 4337 Consumer.addKeywordResult("_Alignof"); 4338 } 4339 } 4340 4341 if (CCC.WantRemainingKeywords) { 4342 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) { 4343 // Statements. 4344 static const char *const CStmts[] = { 4345 "do", "else", "for", "goto", "if", "return", "switch", "while" }; 4346 const unsigned NumCStmts = llvm::array_lengthof(CStmts); 4347 for (unsigned I = 0; I != NumCStmts; ++I) 4348 Consumer.addKeywordResult(CStmts[I]); 4349 4350 if (SemaRef.getLangOpts().CPlusPlus) { 4351 Consumer.addKeywordResult("catch"); 4352 Consumer.addKeywordResult("try"); 4353 } 4354 4355 if (S && S->getBreakParent()) 4356 Consumer.addKeywordResult("break"); 4357 4358 if (S && S->getContinueParent()) 4359 Consumer.addKeywordResult("continue"); 4360 4361 if (!SemaRef.getCurFunction()->SwitchStack.empty()) { 4362 Consumer.addKeywordResult("case"); 4363 Consumer.addKeywordResult("default"); 4364 } 4365 } else { 4366 if (SemaRef.getLangOpts().CPlusPlus) { 4367 Consumer.addKeywordResult("namespace"); 4368 Consumer.addKeywordResult("template"); 4369 } 4370 4371 if (S && S->isClassScope()) { 4372 Consumer.addKeywordResult("explicit"); 4373 Consumer.addKeywordResult("friend"); 4374 Consumer.addKeywordResult("mutable"); 4375 Consumer.addKeywordResult("private"); 4376 Consumer.addKeywordResult("protected"); 4377 Consumer.addKeywordResult("public"); 4378 Consumer.addKeywordResult("virtual"); 4379 } 4380 } 4381 4382 if (SemaRef.getLangOpts().CPlusPlus) { 4383 Consumer.addKeywordResult("using"); 4384 4385 if (SemaRef.getLangOpts().CPlusPlus11) 4386 Consumer.addKeywordResult("static_assert"); 4387 } 4388 } 4389} 4390 4391std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer( 4392 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind, 4393 Scope *S, CXXScopeSpec *SS, 4394 std::unique_ptr<CorrectionCandidateCallback> CCC, 4395 DeclContext *MemberContext, bool EnteringContext, 4396 const ObjCObjectPointerType *OPT, bool ErrorRecovery) { 4397 4398 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking || 4399 DisableTypoCorrection) 4400 return nullptr; 4401 4402 // In Microsoft mode, don't perform typo correction in a template member 4403 // function dependent context because it interferes with the "lookup into 4404 // dependent bases of class templates" feature. 4405 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() && 4406 isa<CXXMethodDecl>(CurContext)) 4407 return nullptr; 4408 4409 // We only attempt to correct typos for identifiers. 4410 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 4411 if (!Typo) 4412 return nullptr; 4413 4414 // If the scope specifier itself was invalid, don't try to correct 4415 // typos. 4416 if (SS && SS->isInvalid()) 4417 return nullptr; 4418 4419 // Never try to correct typos during template deduction or 4420 // instantiation. 4421 if (!ActiveTemplateInstantiations.empty()) 4422 return nullptr; 4423 4424 // Don't try to correct 'super'. 4425 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier()) 4426 return nullptr; 4427 4428 // Abort if typo correction already failed for this specific typo. 4429 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo); 4430 if (locs != TypoCorrectionFailures.end() && 4431 locs->second.count(TypoName.getLoc())) 4432 return nullptr; 4433 4434 // Don't try to correct the identifier "vector" when in AltiVec mode. 4435 // TODO: Figure out why typo correction misbehaves in this case, fix it, and 4436 // remove this workaround. 4437 if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector")) 4438 return nullptr; 4439 4440 // Provide a stop gap for files that are just seriously broken. Trying 4441 // to correct all typos can turn into a HUGE performance penalty, causing 4442 // some files to take minutes to get rejected by the parser. 4443 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit; 4444 if (Limit && TyposCorrected >= Limit) 4445 return nullptr; 4446 ++TyposCorrected; 4447 4448 // If we're handling a missing symbol error, using modules, and the 4449 // special search all modules option is used, look for a missing import. 4450 if (ErrorRecovery && getLangOpts().Modules && 4451 getLangOpts().ModulesSearchAll) { 4452 // The following has the side effect of loading the missing module. 4453 getModuleLoader().lookupMissingImports(Typo->getName(), 4454 TypoName.getLocStart()); 4455 } 4456 4457 CorrectionCandidateCallback &CCCRef = *CCC; 4458 auto Consumer = llvm::make_unique<TypoCorrectionConsumer>( 4459 *this, TypoName, LookupKind, S, SS, std::move(CCC), MemberContext, 4460 EnteringContext); 4461 4462 // Perform name lookup to find visible, similarly-named entities. 4463 bool IsUnqualifiedLookup = false; 4464 DeclContext *QualifiedDC = MemberContext; 4465 if (MemberContext) { 4466 LookupVisibleDecls(MemberContext, LookupKind, *Consumer); 4467 4468 // Look in qualified interfaces. 4469 if (OPT) { 4470 for (auto *I : OPT->quals()) 4471 LookupVisibleDecls(I, LookupKind, *Consumer); 4472 } 4473 } else if (SS && SS->isSet()) { 4474 QualifiedDC = computeDeclContext(*SS, EnteringContext); 4475 if (!QualifiedDC) 4476 return nullptr; 4477 4478 LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer); 4479 } else { 4480 IsUnqualifiedLookup = true; 4481 } 4482 4483 // Determine whether we are going to search in the various namespaces for 4484 // corrections. 4485 bool SearchNamespaces 4486 = getLangOpts().CPlusPlus && 4487 (IsUnqualifiedLookup || (SS && SS->isSet())); 4488 4489 if (IsUnqualifiedLookup || SearchNamespaces) { 4490 // For unqualified lookup, look through all of the names that we have 4491 // seen in this translation unit. 4492 // FIXME: Re-add the ability to skip very unlikely potential corrections. 4493 for (const auto &I : Context.Idents) 4494 Consumer->FoundName(I.getKey()); 4495 4496 // Walk through identifiers in external identifier sources. 4497 // FIXME: Re-add the ability to skip very unlikely potential corrections. 4498 if (IdentifierInfoLookup *External 4499 = Context.Idents.getExternalIdentifierLookup()) { 4500 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers()); 4501 do { 4502 StringRef Name = Iter->Next(); 4503 if (Name.empty()) 4504 break; 4505 4506 Consumer->FoundName(Name); 4507 } while (true); 4508 } 4509 } 4510 4511 AddKeywordsToConsumer(*this, *Consumer, S, CCCRef, SS && SS->isNotEmpty()); 4512 4513 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going 4514 // to search those namespaces. 4515 if (SearchNamespaces) { 4516 // Load any externally-known namespaces. 4517 if (ExternalSource && !LoadedExternalKnownNamespaces) { 4518 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces; 4519 LoadedExternalKnownNamespaces = true; 4520 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces); 4521 for (auto *N : ExternalKnownNamespaces) 4522 KnownNamespaces[N] = true; 4523 } 4524 4525 Consumer->addNamespaces(KnownNamespaces); 4526 } 4527 4528 return Consumer; 4529} 4530 4531/// \brief Try to "correct" a typo in the source code by finding 4532/// visible declarations whose names are similar to the name that was 4533/// present in the source code. 4534/// 4535/// \param TypoName the \c DeclarationNameInfo structure that contains 4536/// the name that was present in the source code along with its location. 4537/// 4538/// \param LookupKind the name-lookup criteria used to search for the name. 4539/// 4540/// \param S the scope in which name lookup occurs. 4541/// 4542/// \param SS the nested-name-specifier that precedes the name we're 4543/// looking for, if present. 4544/// 4545/// \param CCC A CorrectionCandidateCallback object that provides further 4546/// validation of typo correction candidates. It also provides flags for 4547/// determining the set of keywords permitted. 4548/// 4549/// \param MemberContext if non-NULL, the context in which to look for 4550/// a member access expression. 4551/// 4552/// \param EnteringContext whether we're entering the context described by 4553/// the nested-name-specifier SS. 4554/// 4555/// \param OPT when non-NULL, the search for visible declarations will 4556/// also walk the protocols in the qualified interfaces of \p OPT. 4557/// 4558/// \returns a \c TypoCorrection containing the corrected name if the typo 4559/// along with information such as the \c NamedDecl where the corrected name 4560/// was declared, and any additional \c NestedNameSpecifier needed to access 4561/// it (C++ only). The \c TypoCorrection is empty if there is no correction. 4562TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName, 4563 Sema::LookupNameKind LookupKind, 4564 Scope *S, CXXScopeSpec *SS, 4565 std::unique_ptr<CorrectionCandidateCallback> CCC, 4566 CorrectTypoKind Mode, 4567 DeclContext *MemberContext, 4568 bool EnteringContext, 4569 const ObjCObjectPointerType *OPT, 4570 bool RecordFailure) { 4571 assert(CCC && "CorrectTypo requires a CorrectionCandidateCallback"); 4572 4573 // Always let the ExternalSource have the first chance at correction, even 4574 // if we would otherwise have given up. 4575 if (ExternalSource) { 4576 if (TypoCorrection Correction = ExternalSource->CorrectTypo( 4577 TypoName, LookupKind, S, SS, *CCC, MemberContext, EnteringContext, OPT)) 4578 return Correction; 4579 } 4580 4581 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver; 4582 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for 4583 // some instances of CTC_Unknown, while WantRemainingKeywords is true 4584 // for CTC_Unknown but not for CTC_ObjCMessageReceiver. 4585 bool ObjCMessageReceiver = CCC->WantObjCSuper && !CCC->WantRemainingKeywords; 4586 4587 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 4588 auto Consumer = makeTypoCorrectionConsumer( 4589 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext, 4590 EnteringContext, OPT, Mode == CTK_ErrorRecovery); 4591 4592 if (!Consumer) 4593 return TypoCorrection(); 4594 4595 // If we haven't found anything, we're done. 4596 if (Consumer->empty()) 4597 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 4598 4599 // Make sure the best edit distance (prior to adding any namespace qualifiers) 4600 // is not more that about a third of the length of the typo's identifier. 4601 unsigned ED = Consumer->getBestEditDistance(true); 4602 unsigned TypoLen = Typo->getName().size(); 4603 if (ED > 0 && TypoLen / ED < 3) 4604 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 4605 4606 TypoCorrection BestTC = Consumer->getNextCorrection(); 4607 TypoCorrection SecondBestTC = Consumer->getNextCorrection(); 4608 if (!BestTC) 4609 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 4610 4611 ED = BestTC.getEditDistance(); 4612 4613 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) { 4614 // If this was an unqualified lookup and we believe the callback 4615 // object wouldn't have filtered out possible corrections, note 4616 // that no correction was found. 4617 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 4618 } 4619 4620 // If only a single name remains, return that result. 4621 if (!SecondBestTC || 4622 SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) { 4623 const TypoCorrection &Result = BestTC; 4624 4625 // Don't correct to a keyword that's the same as the typo; the keyword 4626 // wasn't actually in scope. 4627 if (ED == 0 && Result.isKeyword()) 4628 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 4629 4630 TypoCorrection TC = Result; 4631 TC.setCorrectionRange(SS, TypoName); 4632 checkCorrectionVisibility(*this, TC); 4633 return TC; 4634 } else if (SecondBestTC && ObjCMessageReceiver) { 4635 // Prefer 'super' when we're completing in a message-receiver 4636 // context. 4637 4638 if (BestTC.getCorrection().getAsString() != "super") { 4639 if (SecondBestTC.getCorrection().getAsString() == "super") 4640 BestTC = SecondBestTC; 4641 else if ((*Consumer)["super"].front().isKeyword()) 4642 BestTC = (*Consumer)["super"].front(); 4643 } 4644 // Don't correct to a keyword that's the same as the typo; the keyword 4645 // wasn't actually in scope. 4646 if (BestTC.getEditDistance() == 0 || 4647 BestTC.getCorrection().getAsString() != "super") 4648 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 4649 4650 BestTC.setCorrectionRange(SS, TypoName); 4651 return BestTC; 4652 } 4653 4654 // Record the failure's location if needed and return an empty correction. If 4655 // this was an unqualified lookup and we believe the callback object did not 4656 // filter out possible corrections, also cache the failure for the typo. 4657 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC); 4658} 4659 4660/// \brief Try to "correct" a typo in the source code by finding 4661/// visible declarations whose names are similar to the name that was 4662/// present in the source code. 4663/// 4664/// \param TypoName the \c DeclarationNameInfo structure that contains 4665/// the name that was present in the source code along with its location. 4666/// 4667/// \param LookupKind the name-lookup criteria used to search for the name. 4668/// 4669/// \param S the scope in which name lookup occurs. 4670/// 4671/// \param SS the nested-name-specifier that precedes the name we're 4672/// looking for, if present. 4673/// 4674/// \param CCC A CorrectionCandidateCallback object that provides further 4675/// validation of typo correction candidates. It also provides flags for 4676/// determining the set of keywords permitted. 4677/// 4678/// \param TDG A TypoDiagnosticGenerator functor that will be used to print 4679/// diagnostics when the actual typo correction is attempted. 4680/// 4681/// \param TRC A TypoRecoveryCallback functor that will be used to build an 4682/// Expr from a typo correction candidate. 4683/// 4684/// \param MemberContext if non-NULL, the context in which to look for 4685/// a member access expression. 4686/// 4687/// \param EnteringContext whether we're entering the context described by 4688/// the nested-name-specifier SS. 4689/// 4690/// \param OPT when non-NULL, the search for visible declarations will 4691/// also walk the protocols in the qualified interfaces of \p OPT. 4692/// 4693/// \returns a new \c TypoExpr that will later be replaced in the AST with an 4694/// Expr representing the result of performing typo correction, or nullptr if 4695/// typo correction is not possible. If nullptr is returned, no diagnostics will 4696/// be emitted and it is the responsibility of the caller to emit any that are 4697/// needed. 4698TypoExpr *Sema::CorrectTypoDelayed( 4699 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind, 4700 Scope *S, CXXScopeSpec *SS, 4701 std::unique_ptr<CorrectionCandidateCallback> CCC, 4702 TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode, 4703 DeclContext *MemberContext, bool EnteringContext, 4704 const ObjCObjectPointerType *OPT) { 4705 assert(CCC && "CorrectTypoDelayed requires a CorrectionCandidateCallback"); 4706 4707 TypoCorrection Empty; 4708 auto Consumer = makeTypoCorrectionConsumer( 4709 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext, 4710 EnteringContext, OPT, Mode == CTK_ErrorRecovery); 4711 4712 if (!Consumer || Consumer->empty()) 4713 return nullptr; 4714 4715 // Make sure the best edit distance (prior to adding any namespace qualifiers) 4716 // is not more that about a third of the length of the typo's identifier. 4717 unsigned ED = Consumer->getBestEditDistance(true); 4718 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 4719 if (ED > 0 && Typo->getName().size() / ED < 3) 4720 return nullptr; 4721 4722 ExprEvalContexts.back().NumTypos++; 4723 return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC)); 4724} 4725 4726void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) { 4727 if (!CDecl) return; 4728 4729 if (isKeyword()) 4730 CorrectionDecls.clear(); 4731 4732 CorrectionDecls.push_back(CDecl); 4733 4734 if (!CorrectionName) 4735 CorrectionName = CDecl->getDeclName(); 4736} 4737 4738std::string TypoCorrection::getAsString(const LangOptions &LO) const { 4739 if (CorrectionNameSpec) { 4740 std::string tmpBuffer; 4741 llvm::raw_string_ostream PrefixOStream(tmpBuffer); 4742 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO)); 4743 PrefixOStream << CorrectionName; 4744 return PrefixOStream.str(); 4745 } 4746 4747 return CorrectionName.getAsString(); 4748} 4749 4750bool CorrectionCandidateCallback::ValidateCandidate( 4751 const TypoCorrection &candidate) { 4752 if (!candidate.isResolved()) 4753 return true; 4754 4755 if (candidate.isKeyword()) 4756 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts || 4757 WantRemainingKeywords || WantObjCSuper; 4758 4759 bool HasNonType = false; 4760 bool HasStaticMethod = false; 4761 bool HasNonStaticMethod = false; 4762 for (Decl *D : candidate) { 4763 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D)) 4764 D = FTD->getTemplatedDecl(); 4765 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 4766 if (Method->isStatic()) 4767 HasStaticMethod = true; 4768 else 4769 HasNonStaticMethod = true; 4770 } 4771 if (!isa<TypeDecl>(D)) 4772 HasNonType = true; 4773 } 4774 4775 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod && 4776 !candidate.getCorrectionSpecifier()) 4777 return false; 4778 4779 return WantTypeSpecifiers || HasNonType; 4780} 4781 4782FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs, 4783 bool HasExplicitTemplateArgs, 4784 MemberExpr *ME) 4785 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs), 4786 CurContext(SemaRef.CurContext), MemberFn(ME) { 4787 WantTypeSpecifiers = false; 4788 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && NumArgs == 1; 4789 WantRemainingKeywords = false; 4790} 4791 4792bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) { 4793 if (!candidate.getCorrectionDecl()) 4794 return candidate.isKeyword(); 4795 4796 for (auto *C : candidate) { 4797 FunctionDecl *FD = nullptr; 4798 NamedDecl *ND = C->getUnderlyingDecl(); 4799 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 4800 FD = FTD->getTemplatedDecl(); 4801 if (!HasExplicitTemplateArgs && !FD) { 4802 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) { 4803 // If the Decl is neither a function nor a template function, 4804 // determine if it is a pointer or reference to a function. If so, 4805 // check against the number of arguments expected for the pointee. 4806 QualType ValType = cast<ValueDecl>(ND)->getType(); 4807 if (ValType->isAnyPointerType() || ValType->isReferenceType()) 4808 ValType = ValType->getPointeeType(); 4809 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>()) 4810 if (FPT->getNumParams() == NumArgs) 4811 return true; 4812 } 4813 } 4814 4815 // Skip the current candidate if it is not a FunctionDecl or does not accept 4816 // the current number of arguments. 4817 if (!FD || !(FD->getNumParams() >= NumArgs && 4818 FD->getMinRequiredArguments() <= NumArgs)) 4819 continue; 4820 4821 // If the current candidate is a non-static C++ method, skip the candidate 4822 // unless the method being corrected--or the current DeclContext, if the 4823 // function being corrected is not a method--is a method in the same class 4824 // or a descendent class of the candidate's parent class. 4825 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) { 4826 if (MemberFn || !MD->isStatic()) { 4827 CXXMethodDecl *CurMD = 4828 MemberFn 4829 ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl()) 4830 : dyn_cast_or_null<CXXMethodDecl>(CurContext); 4831 CXXRecordDecl *CurRD = 4832 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr; 4833 CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl(); 4834 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD))) 4835 continue; 4836 } 4837 } 4838 return true; 4839 } 4840 return false; 4841} 4842 4843void Sema::diagnoseTypo(const TypoCorrection &Correction, 4844 const PartialDiagnostic &TypoDiag, 4845 bool ErrorRecovery) { 4846 diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl), 4847 ErrorRecovery); 4848} 4849 4850/// Find which declaration we should import to provide the definition of 4851/// the given declaration. 4852static NamedDecl *getDefinitionToImport(NamedDecl *D) { 4853 if (VarDecl *VD = dyn_cast<VarDecl>(D)) 4854 return VD->getDefinition(); 4855 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) 4856 return FD->isDefined(FD) ? const_cast<FunctionDecl*>(FD) : nullptr; 4857 if (TagDecl *TD = dyn_cast<TagDecl>(D)) 4858 return TD->getDefinition(); 4859 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D)) 4860 return ID->getDefinition(); 4861 if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D)) 4862 return PD->getDefinition(); 4863 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D)) 4864 return getDefinitionToImport(TD->getTemplatedDecl()); 4865 return nullptr; 4866} 4867 4868void Sema::diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl, 4869 bool NeedDefinition, bool Recover) { 4870 assert(!isVisible(Decl) && "missing import for non-hidden decl?"); 4871 4872 // Suggest importing a module providing the definition of this entity, if 4873 // possible. 4874 NamedDecl *Def = getDefinitionToImport(Decl); 4875 if (!Def) 4876 Def = Decl; 4877 4878 // FIXME: Add a Fix-It that imports the corresponding module or includes 4879 // the header. 4880 Module *Owner = getOwningModule(Decl); 4881 assert(Owner && "definition of hidden declaration is not in a module"); 4882 4883 llvm::SmallVector<Module*, 8> OwningModules; 4884 OwningModules.push_back(Owner); 4885 auto Merged = Context.getModulesWithMergedDefinition(Decl); 4886 OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end()); 4887 4888 diagnoseMissingImport(Loc, Decl, Decl->getLocation(), OwningModules, 4889 NeedDefinition ? MissingImportKind::Definition 4890 : MissingImportKind::Declaration, 4891 Recover); 4892} 4893 4894void Sema::diagnoseMissingImport(SourceLocation UseLoc, NamedDecl *Decl, 4895 SourceLocation DeclLoc, 4896 ArrayRef<Module *> Modules, 4897 MissingImportKind MIK, bool Recover) { 4898 assert(!Modules.empty()); 4899 4900 if (Modules.size() > 1) { 4901 std::string ModuleList; 4902 unsigned N = 0; 4903 for (Module *M : Modules) { 4904 ModuleList += "\n "; 4905 if (++N == 5 && N != Modules.size()) { 4906 ModuleList += "[...]"; 4907 break; 4908 } 4909 ModuleList += M->getFullModuleName(); 4910 } 4911 4912 Diag(UseLoc, diag::err_module_unimported_use_multiple) 4913 << (int)MIK << Decl << ModuleList; 4914 } else { 4915 Diag(UseLoc, diag::err_module_unimported_use) 4916 << (int)MIK << Decl << Modules[0]->getFullModuleName(); 4917 } 4918 4919 unsigned DiagID; 4920 switch (MIK) { 4921 case MissingImportKind::Declaration: 4922 DiagID = diag::note_previous_declaration; 4923 break; 4924 case MissingImportKind::Definition: 4925 DiagID = diag::note_previous_definition; 4926 break; 4927 case MissingImportKind::DefaultArgument: 4928 DiagID = diag::note_default_argument_declared_here; 4929 break; 4930 } 4931 Diag(DeclLoc, DiagID); 4932 4933 // Try to recover by implicitly importing this module. 4934 if (Recover) 4935 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]); 4936} 4937 4938/// \brief Diagnose a successfully-corrected typo. Separated from the correction 4939/// itself to allow external validation of the result, etc. 4940/// 4941/// \param Correction The result of performing typo correction. 4942/// \param TypoDiag The diagnostic to produce. This will have the corrected 4943/// string added to it (and usually also a fixit). 4944/// \param PrevNote A note to use when indicating the location of the entity to 4945/// which we are correcting. Will have the correction string added to it. 4946/// \param ErrorRecovery If \c true (the default), the caller is going to 4947/// recover from the typo as if the corrected string had been typed. 4948/// In this case, \c PDiag must be an error, and we will attach a fixit 4949/// to it. 4950void Sema::diagnoseTypo(const TypoCorrection &Correction, 4951 const PartialDiagnostic &TypoDiag, 4952 const PartialDiagnostic &PrevNote, 4953 bool ErrorRecovery) { 4954 std::string CorrectedStr = Correction.getAsString(getLangOpts()); 4955 std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts()); 4956 FixItHint FixTypo = FixItHint::CreateReplacement( 4957 Correction.getCorrectionRange(), CorrectedStr); 4958 4959 // Maybe we're just missing a module import. 4960 if (Correction.requiresImport()) { 4961 NamedDecl *Decl = Correction.getFoundDecl(); 4962 assert(Decl && "import required but no declaration to import"); 4963 4964 diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl, 4965 /*NeedDefinition*/ false, ErrorRecovery); 4966 return; 4967 } 4968 4969 Diag(Correction.getCorrectionRange().getBegin(), TypoDiag) 4970 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint()); 4971 4972 NamedDecl *ChosenDecl = 4973 Correction.isKeyword() ? nullptr : Correction.getFoundDecl(); 4974 if (PrevNote.getDiagID() && ChosenDecl) 4975 Diag(ChosenDecl->getLocation(), PrevNote) 4976 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo); 4977} 4978 4979TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC, 4980 TypoDiagnosticGenerator TDG, 4981 TypoRecoveryCallback TRC) { 4982 assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer"); 4983 auto TE = new (Context) TypoExpr(Context.DependentTy); 4984 auto &State = DelayedTypos[TE]; 4985 State.Consumer = std::move(TCC); 4986 State.DiagHandler = std::move(TDG); 4987 State.RecoveryHandler = std::move(TRC); 4988 return TE; 4989} 4990 4991const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const { 4992 auto Entry = DelayedTypos.find(TE); 4993 assert(Entry != DelayedTypos.end() && 4994 "Failed to get the state for a TypoExpr!"); 4995 return Entry->second; 4996} 4997 4998void Sema::clearDelayedTypo(TypoExpr *TE) { 4999 DelayedTypos.erase(TE); 5000} 5001 5002void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) { 5003 DeclarationNameInfo Name(II, IILoc); 5004 LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration); 5005 R.suppressDiagnostics(); 5006 R.setHideTags(false); 5007 LookupName(R, S); 5008 R.dump(); 5009} 5010