1 //===--------------------- SemaLookup.cpp - Name Lookup ------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements name lookup for C, C++, Objective-C, and 10 // Objective-C++. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "clang/AST/ASTContext.h" 15 #include "clang/AST/CXXInheritance.h" 16 #include "clang/AST/Decl.h" 17 #include "clang/AST/DeclCXX.h" 18 #include "clang/AST/DeclLookups.h" 19 #include "clang/AST/DeclObjC.h" 20 #include "clang/AST/DeclTemplate.h" 21 #include "clang/AST/Expr.h" 22 #include "clang/AST/ExprCXX.h" 23 #include "clang/Basic/Builtins.h" 24 #include "clang/Basic/FileManager.h" 25 #include "clang/Basic/LangOptions.h" 26 #include "clang/Lex/HeaderSearch.h" 27 #include "clang/Lex/ModuleLoader.h" 28 #include "clang/Lex/Preprocessor.h" 29 #include "clang/Sema/DeclSpec.h" 30 #include "clang/Sema/Lookup.h" 31 #include "clang/Sema/Overload.h" 32 #include "clang/Sema/RISCVIntrinsicManager.h" 33 #include "clang/Sema/Scope.h" 34 #include "clang/Sema/ScopeInfo.h" 35 #include "clang/Sema/Sema.h" 36 #include "clang/Sema/SemaInternal.h" 37 #include "clang/Sema/TemplateDeduction.h" 38 #include "clang/Sema/TypoCorrection.h" 39 #include "llvm/ADT/STLExtras.h" 40 #include "llvm/ADT/SmallPtrSet.h" 41 #include "llvm/ADT/TinyPtrVector.h" 42 #include "llvm/ADT/edit_distance.h" 43 #include "llvm/Support/Casting.h" 44 #include "llvm/Support/ErrorHandling.h" 45 #include <algorithm> 46 #include <iterator> 47 #include <list> 48 #include <optional> 49 #include <set> 50 #include <utility> 51 #include <vector> 52 53 #include "OpenCLBuiltins.inc" 54 55 using namespace clang; 56 using namespace sema; 57 58 namespace { 59 class UnqualUsingEntry { 60 const DeclContext *Nominated; 61 const DeclContext *CommonAncestor; 62 63 public: 64 UnqualUsingEntry(const DeclContext *Nominated, 65 const DeclContext *CommonAncestor) 66 : Nominated(Nominated), CommonAncestor(CommonAncestor) { 67 } 68 69 const DeclContext *getCommonAncestor() const { 70 return CommonAncestor; 71 } 72 73 const DeclContext *getNominatedNamespace() const { 74 return Nominated; 75 } 76 77 // Sort by the pointer value of the common ancestor. 78 struct Comparator { 79 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) { 80 return L.getCommonAncestor() < R.getCommonAncestor(); 81 } 82 83 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) { 84 return E.getCommonAncestor() < DC; 85 } 86 87 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) { 88 return DC < E.getCommonAncestor(); 89 } 90 }; 91 }; 92 93 /// A collection of using directives, as used by C++ unqualified 94 /// lookup. 95 class UnqualUsingDirectiveSet { 96 Sema &SemaRef; 97 98 typedef SmallVector<UnqualUsingEntry, 8> ListTy; 99 100 ListTy list; 101 llvm::SmallPtrSet<DeclContext*, 8> visited; 102 103 public: 104 UnqualUsingDirectiveSet(Sema &SemaRef) : SemaRef(SemaRef) {} 105 106 void visitScopeChain(Scope *S, Scope *InnermostFileScope) { 107 // C++ [namespace.udir]p1: 108 // During unqualified name lookup, the names appear as if they 109 // were declared in the nearest enclosing namespace which contains 110 // both the using-directive and the nominated namespace. 111 DeclContext *InnermostFileDC = InnermostFileScope->getEntity(); 112 assert(InnermostFileDC && InnermostFileDC->isFileContext()); 113 114 for (; S; S = S->getParent()) { 115 // C++ [namespace.udir]p1: 116 // A using-directive shall not appear in class scope, but may 117 // appear in namespace scope or in block scope. 118 DeclContext *Ctx = S->getEntity(); 119 if (Ctx && Ctx->isFileContext()) { 120 visit(Ctx, Ctx); 121 } else if (!Ctx || Ctx->isFunctionOrMethod()) { 122 for (auto *I : S->using_directives()) 123 if (SemaRef.isVisible(I)) 124 visit(I, InnermostFileDC); 125 } 126 } 127 } 128 129 // Visits a context and collect all of its using directives 130 // recursively. Treats all using directives as if they were 131 // declared in the context. 132 // 133 // A given context is only every visited once, so it is important 134 // that contexts be visited from the inside out in order to get 135 // the effective DCs right. 136 void visit(DeclContext *DC, DeclContext *EffectiveDC) { 137 if (!visited.insert(DC).second) 138 return; 139 140 addUsingDirectives(DC, EffectiveDC); 141 } 142 143 // Visits a using directive and collects all of its using 144 // directives recursively. Treats all using directives as if they 145 // were declared in the effective DC. 146 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 147 DeclContext *NS = UD->getNominatedNamespace(); 148 if (!visited.insert(NS).second) 149 return; 150 151 addUsingDirective(UD, EffectiveDC); 152 addUsingDirectives(NS, EffectiveDC); 153 } 154 155 // Adds all the using directives in a context (and those nominated 156 // by its using directives, transitively) as if they appeared in 157 // the given effective context. 158 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) { 159 SmallVector<DeclContext*, 4> queue; 160 while (true) { 161 for (auto *UD : DC->using_directives()) { 162 DeclContext *NS = UD->getNominatedNamespace(); 163 if (SemaRef.isVisible(UD) && visited.insert(NS).second) { 164 addUsingDirective(UD, EffectiveDC); 165 queue.push_back(NS); 166 } 167 } 168 169 if (queue.empty()) 170 return; 171 172 DC = queue.pop_back_val(); 173 } 174 } 175 176 // Add a using directive as if it had been declared in the given 177 // context. This helps implement C++ [namespace.udir]p3: 178 // The using-directive is transitive: if a scope contains a 179 // using-directive that nominates a second namespace that itself 180 // contains using-directives, the effect is as if the 181 // using-directives from the second namespace also appeared in 182 // the first. 183 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 184 // Find the common ancestor between the effective context and 185 // the nominated namespace. 186 DeclContext *Common = UD->getNominatedNamespace(); 187 while (!Common->Encloses(EffectiveDC)) 188 Common = Common->getParent(); 189 Common = Common->getPrimaryContext(); 190 191 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common)); 192 } 193 194 void done() { llvm::sort(list, UnqualUsingEntry::Comparator()); } 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(const 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. 212 static 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 case Sema::LookupDestructorName: 222 IDNS = Decl::IDNS_Ordinary; 223 if (CPlusPlus) { 224 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace; 225 if (Redeclaration) 226 IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend; 227 } 228 if (Redeclaration) 229 IDNS |= Decl::IDNS_LocalExtern; 230 break; 231 232 case Sema::LookupOperatorName: 233 // Operator lookup is its own crazy thing; it is not the same 234 // as (e.g.) looking up an operator name for redeclaration. 235 assert(!Redeclaration && "cannot do redeclaration operator lookup"); 236 IDNS = Decl::IDNS_NonMemberOperator; 237 break; 238 239 case Sema::LookupTagName: 240 if (CPlusPlus) { 241 IDNS = Decl::IDNS_Type; 242 243 // When looking for a redeclaration of a tag name, we add: 244 // 1) TagFriend to find undeclared friend decls 245 // 2) Namespace because they can't "overload" with tag decls. 246 // 3) Tag because it includes class templates, which can't 247 // "overload" with tag decls. 248 if (Redeclaration) 249 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace; 250 } else { 251 IDNS = Decl::IDNS_Tag; 252 } 253 break; 254 255 case Sema::LookupLabel: 256 IDNS = Decl::IDNS_Label; 257 break; 258 259 case Sema::LookupMemberName: 260 IDNS = Decl::IDNS_Member; 261 if (CPlusPlus) 262 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary; 263 break; 264 265 case Sema::LookupNestedNameSpecifierName: 266 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace; 267 break; 268 269 case Sema::LookupNamespaceName: 270 IDNS = Decl::IDNS_Namespace; 271 break; 272 273 case Sema::LookupUsingDeclName: 274 assert(Redeclaration && "should only be used for redecl lookup"); 275 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member | 276 Decl::IDNS_Using | Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend | 277 Decl::IDNS_LocalExtern; 278 break; 279 280 case Sema::LookupObjCProtocolName: 281 IDNS = Decl::IDNS_ObjCProtocol; 282 break; 283 284 case Sema::LookupOMPReductionName: 285 IDNS = Decl::IDNS_OMPReduction; 286 break; 287 288 case Sema::LookupOMPMapperName: 289 IDNS = Decl::IDNS_OMPMapper; 290 break; 291 292 case Sema::LookupAnyName: 293 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member 294 | Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol 295 | Decl::IDNS_Type; 296 break; 297 } 298 return IDNS; 299 } 300 301 void LookupResult::configure() { 302 IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus, 303 isForRedeclaration()); 304 305 // If we're looking for one of the allocation or deallocation 306 // operators, make sure that the implicitly-declared new and delete 307 // operators can be found. 308 switch (NameInfo.getName().getCXXOverloadedOperator()) { 309 case OO_New: 310 case OO_Delete: 311 case OO_Array_New: 312 case OO_Array_Delete: 313 getSema().DeclareGlobalNewDelete(); 314 break; 315 316 default: 317 break; 318 } 319 320 // Compiler builtins are always visible, regardless of where they end 321 // up being declared. 322 if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) { 323 if (unsigned BuiltinID = Id->getBuiltinID()) { 324 if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 325 AllowHidden = true; 326 } 327 } 328 } 329 330 bool LookupResult::checkDebugAssumptions() const { 331 // This function is never called by NDEBUG builds. 332 assert(ResultKind != NotFound || Decls.size() == 0); 333 assert(ResultKind != Found || Decls.size() == 1); 334 assert(ResultKind != FoundOverloaded || Decls.size() > 1 || 335 (Decls.size() == 1 && 336 isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl()))); 337 assert(ResultKind != FoundUnresolvedValue || checkUnresolved()); 338 assert(ResultKind != Ambiguous || Decls.size() > 1 || 339 (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects || 340 Ambiguity == AmbiguousBaseSubobjectTypes))); 341 assert((Paths != nullptr) == (ResultKind == Ambiguous && 342 (Ambiguity == AmbiguousBaseSubobjectTypes || 343 Ambiguity == AmbiguousBaseSubobjects))); 344 return true; 345 } 346 347 // Necessary because CXXBasePaths is not complete in Sema.h 348 void LookupResult::deletePaths(CXXBasePaths *Paths) { 349 delete Paths; 350 } 351 352 /// Get a representative context for a declaration such that two declarations 353 /// will have the same context if they were found within the same scope. 354 static const DeclContext *getContextForScopeMatching(const Decl *D) { 355 // For function-local declarations, use that function as the context. This 356 // doesn't account for scopes within the function; the caller must deal with 357 // those. 358 if (const DeclContext *DC = D->getLexicalDeclContext(); 359 DC->isFunctionOrMethod()) 360 return DC; 361 362 // Otherwise, look at the semantic context of the declaration. The 363 // declaration must have been found there. 364 return D->getDeclContext()->getRedeclContext(); 365 } 366 367 /// Determine whether \p D is a better lookup result than \p Existing, 368 /// given that they declare the same entity. 369 static bool isPreferredLookupResult(Sema &S, Sema::LookupNameKind Kind, 370 const NamedDecl *D, 371 const NamedDecl *Existing) { 372 // When looking up redeclarations of a using declaration, prefer a using 373 // shadow declaration over any other declaration of the same entity. 374 if (Kind == Sema::LookupUsingDeclName && isa<UsingShadowDecl>(D) && 375 !isa<UsingShadowDecl>(Existing)) 376 return true; 377 378 const auto *DUnderlying = D->getUnderlyingDecl(); 379 const auto *EUnderlying = Existing->getUnderlyingDecl(); 380 381 // If they have different underlying declarations, prefer a typedef over the 382 // original type (this happens when two type declarations denote the same 383 // type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef 384 // might carry additional semantic information, such as an alignment override. 385 // However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag 386 // declaration over a typedef. Also prefer a tag over a typedef for 387 // destructor name lookup because in some contexts we only accept a 388 // class-name in a destructor declaration. 389 if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) { 390 assert(isa<TypeDecl>(DUnderlying) && isa<TypeDecl>(EUnderlying)); 391 bool HaveTag = isa<TagDecl>(EUnderlying); 392 bool WantTag = 393 Kind == Sema::LookupTagName || Kind == Sema::LookupDestructorName; 394 return HaveTag != WantTag; 395 } 396 397 // Pick the function with more default arguments. 398 // FIXME: In the presence of ambiguous default arguments, we should keep both, 399 // so we can diagnose the ambiguity if the default argument is needed. 400 // See C++ [over.match.best]p3. 401 if (const auto *DFD = dyn_cast<FunctionDecl>(DUnderlying)) { 402 const auto *EFD = cast<FunctionDecl>(EUnderlying); 403 unsigned DMin = DFD->getMinRequiredArguments(); 404 unsigned EMin = EFD->getMinRequiredArguments(); 405 // If D has more default arguments, it is preferred. 406 if (DMin != EMin) 407 return DMin < EMin; 408 // FIXME: When we track visibility for default function arguments, check 409 // that we pick the declaration with more visible default arguments. 410 } 411 412 // Pick the template with more default template arguments. 413 if (const auto *DTD = dyn_cast<TemplateDecl>(DUnderlying)) { 414 const auto *ETD = cast<TemplateDecl>(EUnderlying); 415 unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments(); 416 unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments(); 417 // If D has more default arguments, it is preferred. Note that default 418 // arguments (and their visibility) is monotonically increasing across the 419 // redeclaration chain, so this is a quick proxy for "is more recent". 420 if (DMin != EMin) 421 return DMin < EMin; 422 // If D has more *visible* default arguments, it is preferred. Note, an 423 // earlier default argument being visible does not imply that a later 424 // default argument is visible, so we can't just check the first one. 425 for (unsigned I = DMin, N = DTD->getTemplateParameters()->size(); 426 I != N; ++I) { 427 if (!S.hasVisibleDefaultArgument( 428 ETD->getTemplateParameters()->getParam(I)) && 429 S.hasVisibleDefaultArgument( 430 DTD->getTemplateParameters()->getParam(I))) 431 return true; 432 } 433 } 434 435 // VarDecl can have incomplete array types, prefer the one with more complete 436 // array type. 437 if (const auto *DVD = dyn_cast<VarDecl>(DUnderlying)) { 438 const auto *EVD = cast<VarDecl>(EUnderlying); 439 if (EVD->getType()->isIncompleteType() && 440 !DVD->getType()->isIncompleteType()) { 441 // Prefer the decl with a more complete type if visible. 442 return S.isVisible(DVD); 443 } 444 return false; // Avoid picking up a newer decl, just because it was newer. 445 } 446 447 // For most kinds of declaration, it doesn't really matter which one we pick. 448 if (!isa<FunctionDecl>(DUnderlying) && !isa<VarDecl>(DUnderlying)) { 449 // If the existing declaration is hidden, prefer the new one. Otherwise, 450 // keep what we've got. 451 return !S.isVisible(Existing); 452 } 453 454 // Pick the newer declaration; it might have a more precise type. 455 for (const Decl *Prev = DUnderlying->getPreviousDecl(); Prev; 456 Prev = Prev->getPreviousDecl()) 457 if (Prev == EUnderlying) 458 return true; 459 return false; 460 } 461 462 /// Determine whether \p D can hide a tag declaration. 463 static bool canHideTag(const NamedDecl *D) { 464 // C++ [basic.scope.declarative]p4: 465 // Given a set of declarations in a single declarative region [...] 466 // exactly one declaration shall declare a class name or enumeration name 467 // that is not a typedef name and the other declarations shall all refer to 468 // the same variable, non-static data member, or enumerator, or all refer 469 // to functions and function templates; in this case the class name or 470 // enumeration name is hidden. 471 // C++ [basic.scope.hiding]p2: 472 // A class name or enumeration name can be hidden by the name of a 473 // variable, data member, function, or enumerator declared in the same 474 // scope. 475 // An UnresolvedUsingValueDecl always instantiates to one of these. 476 D = D->getUnderlyingDecl(); 477 return isa<VarDecl>(D) || isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D) || 478 isa<FunctionTemplateDecl>(D) || isa<FieldDecl>(D) || 479 isa<UnresolvedUsingValueDecl>(D); 480 } 481 482 /// Resolves the result kind of this lookup. 483 void LookupResult::resolveKind() { 484 unsigned N = Decls.size(); 485 486 // Fast case: no possible ambiguity. 487 if (N == 0) { 488 assert(ResultKind == NotFound || 489 ResultKind == NotFoundInCurrentInstantiation); 490 return; 491 } 492 493 // If there's a single decl, we need to examine it to decide what 494 // kind of lookup this is. 495 if (N == 1) { 496 const NamedDecl *D = (*Decls.begin())->getUnderlyingDecl(); 497 if (isa<FunctionTemplateDecl>(D)) 498 ResultKind = FoundOverloaded; 499 else if (isa<UnresolvedUsingValueDecl>(D)) 500 ResultKind = FoundUnresolvedValue; 501 return; 502 } 503 504 // Don't do any extra resolution if we've already resolved as ambiguous. 505 if (ResultKind == Ambiguous) return; 506 507 llvm::SmallDenseMap<const NamedDecl *, unsigned, 16> Unique; 508 llvm::SmallDenseMap<QualType, unsigned, 16> UniqueTypes; 509 510 bool Ambiguous = false; 511 bool ReferenceToPlaceHolderVariable = false; 512 bool HasTag = false, HasFunction = false; 513 bool HasFunctionTemplate = false, HasUnresolved = false; 514 const NamedDecl *HasNonFunction = nullptr; 515 516 llvm::SmallVector<const NamedDecl *, 4> EquivalentNonFunctions; 517 llvm::BitVector RemovedDecls(N); 518 519 for (unsigned I = 0; I < N; I++) { 520 const NamedDecl *D = Decls[I]->getUnderlyingDecl(); 521 D = cast<NamedDecl>(D->getCanonicalDecl()); 522 523 // Ignore an invalid declaration unless it's the only one left. 524 // Also ignore HLSLBufferDecl which not have name conflict with other Decls. 525 if ((D->isInvalidDecl() || isa<HLSLBufferDecl>(D)) && 526 N - RemovedDecls.count() > 1) { 527 RemovedDecls.set(I); 528 continue; 529 } 530 531 // C++ [basic.scope.hiding]p2: 532 // A class name or enumeration name can be hidden by the name of 533 // an object, function, or enumerator declared in the same 534 // scope. If a class or enumeration name and an object, function, 535 // or enumerator are declared in the same scope (in any order) 536 // with the same name, the class or enumeration name is hidden 537 // wherever the object, function, or enumerator name is visible. 538 if (HideTags && isa<TagDecl>(D)) { 539 bool Hidden = false; 540 for (auto *OtherDecl : Decls) { 541 if (canHideTag(OtherDecl) && !OtherDecl->isInvalidDecl() && 542 getContextForScopeMatching(OtherDecl)->Equals( 543 getContextForScopeMatching(Decls[I]))) { 544 RemovedDecls.set(I); 545 Hidden = true; 546 break; 547 } 548 } 549 if (Hidden) 550 continue; 551 } 552 553 std::optional<unsigned> ExistingI; 554 555 // Redeclarations of types via typedef can occur both within a scope 556 // and, through using declarations and directives, across scopes. There is 557 // no ambiguity if they all refer to the same type, so unique based on the 558 // canonical type. 559 if (const auto *TD = dyn_cast<TypeDecl>(D)) { 560 QualType T = getSema().Context.getTypeDeclType(TD); 561 auto UniqueResult = UniqueTypes.insert( 562 std::make_pair(getSema().Context.getCanonicalType(T), I)); 563 if (!UniqueResult.second) { 564 // The type is not unique. 565 ExistingI = UniqueResult.first->second; 566 } 567 } 568 569 // For non-type declarations, check for a prior lookup result naming this 570 // canonical declaration. 571 if (!D->isPlaceholderVar(getSema().getLangOpts()) && !ExistingI) { 572 auto UniqueResult = Unique.insert(std::make_pair(D, I)); 573 if (!UniqueResult.second) { 574 // We've seen this entity before. 575 ExistingI = UniqueResult.first->second; 576 } 577 } 578 579 if (ExistingI) { 580 // This is not a unique lookup result. Pick one of the results and 581 // discard the other. 582 if (isPreferredLookupResult(getSema(), getLookupKind(), Decls[I], 583 Decls[*ExistingI])) 584 Decls[*ExistingI] = Decls[I]; 585 RemovedDecls.set(I); 586 continue; 587 } 588 589 // Otherwise, do some decl type analysis and then continue. 590 591 if (isa<UnresolvedUsingValueDecl>(D)) { 592 HasUnresolved = true; 593 } else if (isa<TagDecl>(D)) { 594 if (HasTag) 595 Ambiguous = true; 596 HasTag = true; 597 } else if (isa<FunctionTemplateDecl>(D)) { 598 HasFunction = true; 599 HasFunctionTemplate = true; 600 } else if (isa<FunctionDecl>(D)) { 601 HasFunction = true; 602 } else { 603 if (HasNonFunction) { 604 // If we're about to create an ambiguity between two declarations that 605 // are equivalent, but one is an internal linkage declaration from one 606 // module and the other is an internal linkage declaration from another 607 // module, just skip it. 608 if (getSema().isEquivalentInternalLinkageDeclaration(HasNonFunction, 609 D)) { 610 EquivalentNonFunctions.push_back(D); 611 RemovedDecls.set(I); 612 continue; 613 } 614 if (D->isPlaceholderVar(getSema().getLangOpts()) && 615 getContextForScopeMatching(D) == 616 getContextForScopeMatching(Decls[I])) { 617 ReferenceToPlaceHolderVariable = true; 618 } 619 Ambiguous = true; 620 } 621 HasNonFunction = D; 622 } 623 } 624 625 // FIXME: This diagnostic should really be delayed until we're done with 626 // the lookup result, in case the ambiguity is resolved by the caller. 627 if (!EquivalentNonFunctions.empty() && !Ambiguous) 628 getSema().diagnoseEquivalentInternalLinkageDeclarations( 629 getNameLoc(), HasNonFunction, EquivalentNonFunctions); 630 631 // Remove decls by replacing them with decls from the end (which 632 // means that we need to iterate from the end) and then truncating 633 // to the new size. 634 for (int I = RemovedDecls.find_last(); I >= 0; I = RemovedDecls.find_prev(I)) 635 Decls[I] = Decls[--N]; 636 Decls.truncate(N); 637 638 if ((HasNonFunction && (HasFunction || HasUnresolved)) || 639 (HideTags && HasTag && (HasFunction || HasNonFunction || HasUnresolved))) 640 Ambiguous = true; 641 642 if (Ambiguous && ReferenceToPlaceHolderVariable) 643 setAmbiguous(LookupResult::AmbiguousReferenceToPlaceholderVariable); 644 else if (Ambiguous) 645 setAmbiguous(LookupResult::AmbiguousReference); 646 else if (HasUnresolved) 647 ResultKind = LookupResult::FoundUnresolvedValue; 648 else if (N > 1 || HasFunctionTemplate) 649 ResultKind = LookupResult::FoundOverloaded; 650 else 651 ResultKind = LookupResult::Found; 652 } 653 654 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) { 655 CXXBasePaths::const_paths_iterator I, E; 656 for (I = P.begin(), E = P.end(); I != E; ++I) 657 for (DeclContext::lookup_iterator DI = I->Decls, DE = DI.end(); DI != DE; 658 ++DI) 659 addDecl(*DI); 660 } 661 662 void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) { 663 Paths = new CXXBasePaths; 664 Paths->swap(P); 665 addDeclsFromBasePaths(*Paths); 666 resolveKind(); 667 setAmbiguous(AmbiguousBaseSubobjects); 668 } 669 670 void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) { 671 Paths = new CXXBasePaths; 672 Paths->swap(P); 673 addDeclsFromBasePaths(*Paths); 674 resolveKind(); 675 setAmbiguous(AmbiguousBaseSubobjectTypes); 676 } 677 678 void LookupResult::print(raw_ostream &Out) { 679 Out << Decls.size() << " result(s)"; 680 if (isAmbiguous()) Out << ", ambiguous"; 681 if (Paths) Out << ", base paths present"; 682 683 for (iterator I = begin(), E = end(); I != E; ++I) { 684 Out << "\n"; 685 (*I)->print(Out, 2); 686 } 687 } 688 689 LLVM_DUMP_METHOD void LookupResult::dump() { 690 llvm::errs() << "lookup results for " << getLookupName().getAsString() 691 << ":\n"; 692 for (NamedDecl *D : *this) 693 D->dump(); 694 } 695 696 /// Diagnose a missing builtin type. 697 static QualType diagOpenCLBuiltinTypeError(Sema &S, llvm::StringRef TypeClass, 698 llvm::StringRef Name) { 699 S.Diag(SourceLocation(), diag::err_opencl_type_not_found) 700 << TypeClass << Name; 701 return S.Context.VoidTy; 702 } 703 704 /// Lookup an OpenCL enum type. 705 static QualType getOpenCLEnumType(Sema &S, llvm::StringRef Name) { 706 LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(), 707 Sema::LookupTagName); 708 S.LookupName(Result, S.TUScope); 709 if (Result.empty()) 710 return diagOpenCLBuiltinTypeError(S, "enum", Name); 711 EnumDecl *Decl = Result.getAsSingle<EnumDecl>(); 712 if (!Decl) 713 return diagOpenCLBuiltinTypeError(S, "enum", Name); 714 return S.Context.getEnumType(Decl); 715 } 716 717 /// Lookup an OpenCL typedef type. 718 static QualType getOpenCLTypedefType(Sema &S, llvm::StringRef Name) { 719 LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(), 720 Sema::LookupOrdinaryName); 721 S.LookupName(Result, S.TUScope); 722 if (Result.empty()) 723 return diagOpenCLBuiltinTypeError(S, "typedef", Name); 724 TypedefNameDecl *Decl = Result.getAsSingle<TypedefNameDecl>(); 725 if (!Decl) 726 return diagOpenCLBuiltinTypeError(S, "typedef", Name); 727 return S.Context.getTypedefType(Decl); 728 } 729 730 /// Get the QualType instances of the return type and arguments for an OpenCL 731 /// builtin function signature. 732 /// \param S (in) The Sema instance. 733 /// \param OpenCLBuiltin (in) The signature currently handled. 734 /// \param GenTypeMaxCnt (out) Maximum number of types contained in a generic 735 /// type used as return type or as argument. 736 /// Only meaningful for generic types, otherwise equals 1. 737 /// \param RetTypes (out) List of the possible return types. 738 /// \param ArgTypes (out) List of the possible argument types. For each 739 /// argument, ArgTypes contains QualTypes for the Cartesian product 740 /// of (vector sizes) x (types) . 741 static void GetQualTypesForOpenCLBuiltin( 742 Sema &S, const OpenCLBuiltinStruct &OpenCLBuiltin, unsigned &GenTypeMaxCnt, 743 SmallVector<QualType, 1> &RetTypes, 744 SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) { 745 // Get the QualType instances of the return types. 746 unsigned Sig = SignatureTable[OpenCLBuiltin.SigTableIndex]; 747 OCL2Qual(S, TypeTable[Sig], RetTypes); 748 GenTypeMaxCnt = RetTypes.size(); 749 750 // Get the QualType instances of the arguments. 751 // First type is the return type, skip it. 752 for (unsigned Index = 1; Index < OpenCLBuiltin.NumTypes; Index++) { 753 SmallVector<QualType, 1> Ty; 754 OCL2Qual(S, TypeTable[SignatureTable[OpenCLBuiltin.SigTableIndex + Index]], 755 Ty); 756 GenTypeMaxCnt = (Ty.size() > GenTypeMaxCnt) ? Ty.size() : GenTypeMaxCnt; 757 ArgTypes.push_back(std::move(Ty)); 758 } 759 } 760 761 /// Create a list of the candidate function overloads for an OpenCL builtin 762 /// function. 763 /// \param Context (in) The ASTContext instance. 764 /// \param GenTypeMaxCnt (in) Maximum number of types contained in a generic 765 /// type used as return type or as argument. 766 /// Only meaningful for generic types, otherwise equals 1. 767 /// \param FunctionList (out) List of FunctionTypes. 768 /// \param RetTypes (in) List of the possible return types. 769 /// \param ArgTypes (in) List of the possible types for the arguments. 770 static void GetOpenCLBuiltinFctOverloads( 771 ASTContext &Context, unsigned GenTypeMaxCnt, 772 std::vector<QualType> &FunctionList, SmallVector<QualType, 1> &RetTypes, 773 SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) { 774 FunctionProtoType::ExtProtoInfo PI( 775 Context.getDefaultCallingConvention(false, false, true)); 776 PI.Variadic = false; 777 778 // Do not attempt to create any FunctionTypes if there are no return types, 779 // which happens when a type belongs to a disabled extension. 780 if (RetTypes.size() == 0) 781 return; 782 783 // Create FunctionTypes for each (gen)type. 784 for (unsigned IGenType = 0; IGenType < GenTypeMaxCnt; IGenType++) { 785 SmallVector<QualType, 5> ArgList; 786 787 for (unsigned A = 0; A < ArgTypes.size(); A++) { 788 // Bail out if there is an argument that has no available types. 789 if (ArgTypes[A].size() == 0) 790 return; 791 792 // Builtins such as "max" have an "sgentype" argument that represents 793 // the corresponding scalar type of a gentype. The number of gentypes 794 // must be a multiple of the number of sgentypes. 795 assert(GenTypeMaxCnt % ArgTypes[A].size() == 0 && 796 "argument type count not compatible with gentype type count"); 797 unsigned Idx = IGenType % ArgTypes[A].size(); 798 ArgList.push_back(ArgTypes[A][Idx]); 799 } 800 801 FunctionList.push_back(Context.getFunctionType( 802 RetTypes[(RetTypes.size() != 1) ? IGenType : 0], ArgList, PI)); 803 } 804 } 805 806 /// When trying to resolve a function name, if isOpenCLBuiltin() returns a 807 /// non-null <Index, Len> pair, then the name is referencing an OpenCL 808 /// builtin function. Add all candidate signatures to the LookUpResult. 809 /// 810 /// \param S (in) The Sema instance. 811 /// \param LR (inout) The LookupResult instance. 812 /// \param II (in) The identifier being resolved. 813 /// \param FctIndex (in) Starting index in the BuiltinTable. 814 /// \param Len (in) The signature list has Len elements. 815 static void InsertOCLBuiltinDeclarationsFromTable(Sema &S, LookupResult &LR, 816 IdentifierInfo *II, 817 const unsigned FctIndex, 818 const unsigned Len) { 819 // The builtin function declaration uses generic types (gentype). 820 bool HasGenType = false; 821 822 // Maximum number of types contained in a generic type used as return type or 823 // as argument. Only meaningful for generic types, otherwise equals 1. 824 unsigned GenTypeMaxCnt; 825 826 ASTContext &Context = S.Context; 827 828 for (unsigned SignatureIndex = 0; SignatureIndex < Len; SignatureIndex++) { 829 const OpenCLBuiltinStruct &OpenCLBuiltin = 830 BuiltinTable[FctIndex + SignatureIndex]; 831 832 // Ignore this builtin function if it is not available in the currently 833 // selected language version. 834 if (!isOpenCLVersionContainedInMask(Context.getLangOpts(), 835 OpenCLBuiltin.Versions)) 836 continue; 837 838 // Ignore this builtin function if it carries an extension macro that is 839 // not defined. This indicates that the extension is not supported by the 840 // target, so the builtin function should not be available. 841 StringRef Extensions = FunctionExtensionTable[OpenCLBuiltin.Extension]; 842 if (!Extensions.empty()) { 843 SmallVector<StringRef, 2> ExtVec; 844 Extensions.split(ExtVec, " "); 845 bool AllExtensionsDefined = true; 846 for (StringRef Ext : ExtVec) { 847 if (!S.getPreprocessor().isMacroDefined(Ext)) { 848 AllExtensionsDefined = false; 849 break; 850 } 851 } 852 if (!AllExtensionsDefined) 853 continue; 854 } 855 856 SmallVector<QualType, 1> RetTypes; 857 SmallVector<SmallVector<QualType, 1>, 5> ArgTypes; 858 859 // Obtain QualType lists for the function signature. 860 GetQualTypesForOpenCLBuiltin(S, OpenCLBuiltin, GenTypeMaxCnt, RetTypes, 861 ArgTypes); 862 if (GenTypeMaxCnt > 1) { 863 HasGenType = true; 864 } 865 866 // Create function overload for each type combination. 867 std::vector<QualType> FunctionList; 868 GetOpenCLBuiltinFctOverloads(Context, GenTypeMaxCnt, FunctionList, RetTypes, 869 ArgTypes); 870 871 SourceLocation Loc = LR.getNameLoc(); 872 DeclContext *Parent = Context.getTranslationUnitDecl(); 873 FunctionDecl *NewOpenCLBuiltin; 874 875 for (const auto &FTy : FunctionList) { 876 NewOpenCLBuiltin = FunctionDecl::Create( 877 Context, Parent, Loc, Loc, II, FTy, /*TInfo=*/nullptr, SC_Extern, 878 S.getCurFPFeatures().isFPConstrained(), false, 879 FTy->isFunctionProtoType()); 880 NewOpenCLBuiltin->setImplicit(); 881 882 // Create Decl objects for each parameter, adding them to the 883 // FunctionDecl. 884 const auto *FP = cast<FunctionProtoType>(FTy); 885 SmallVector<ParmVarDecl *, 4> ParmList; 886 for (unsigned IParm = 0, e = FP->getNumParams(); IParm != e; ++IParm) { 887 ParmVarDecl *Parm = ParmVarDecl::Create( 888 Context, NewOpenCLBuiltin, SourceLocation(), SourceLocation(), 889 nullptr, FP->getParamType(IParm), nullptr, SC_None, nullptr); 890 Parm->setScopeInfo(0, IParm); 891 ParmList.push_back(Parm); 892 } 893 NewOpenCLBuiltin->setParams(ParmList); 894 895 // Add function attributes. 896 if (OpenCLBuiltin.IsPure) 897 NewOpenCLBuiltin->addAttr(PureAttr::CreateImplicit(Context)); 898 if (OpenCLBuiltin.IsConst) 899 NewOpenCLBuiltin->addAttr(ConstAttr::CreateImplicit(Context)); 900 if (OpenCLBuiltin.IsConv) 901 NewOpenCLBuiltin->addAttr(ConvergentAttr::CreateImplicit(Context)); 902 903 if (!S.getLangOpts().OpenCLCPlusPlus) 904 NewOpenCLBuiltin->addAttr(OverloadableAttr::CreateImplicit(Context)); 905 906 LR.addDecl(NewOpenCLBuiltin); 907 } 908 } 909 910 // If we added overloads, need to resolve the lookup result. 911 if (Len > 1 || HasGenType) 912 LR.resolveKind(); 913 } 914 915 /// Lookup a builtin function, when name lookup would otherwise 916 /// fail. 917 bool Sema::LookupBuiltin(LookupResult &R) { 918 Sema::LookupNameKind NameKind = R.getLookupKind(); 919 920 // If we didn't find a use of this identifier, and if the identifier 921 // corresponds to a compiler builtin, create the decl object for the builtin 922 // now, injecting it into translation unit scope, and return it. 923 if (NameKind == Sema::LookupOrdinaryName || 924 NameKind == Sema::LookupRedeclarationWithLinkage) { 925 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo(); 926 if (II) { 927 if (getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName) { 928 if (II == getASTContext().getMakeIntegerSeqName()) { 929 R.addDecl(getASTContext().getMakeIntegerSeqDecl()); 930 return true; 931 } else if (II == getASTContext().getTypePackElementName()) { 932 R.addDecl(getASTContext().getTypePackElementDecl()); 933 return true; 934 } 935 } 936 937 // Check if this is an OpenCL Builtin, and if so, insert its overloads. 938 if (getLangOpts().OpenCL && getLangOpts().DeclareOpenCLBuiltins) { 939 auto Index = isOpenCLBuiltin(II->getName()); 940 if (Index.first) { 941 InsertOCLBuiltinDeclarationsFromTable(*this, R, II, Index.first - 1, 942 Index.second); 943 return true; 944 } 945 } 946 947 if (DeclareRISCVVBuiltins || DeclareRISCVSiFiveVectorBuiltins) { 948 if (!RVIntrinsicManager) 949 RVIntrinsicManager = CreateRISCVIntrinsicManager(*this); 950 951 RVIntrinsicManager->InitIntrinsicList(); 952 953 if (RVIntrinsicManager->CreateIntrinsicIfFound(R, II, PP)) 954 return true; 955 } 956 957 // If this is a builtin on this (or all) targets, create the decl. 958 if (unsigned BuiltinID = II->getBuiltinID()) { 959 // In C++ and OpenCL (spec v1.2 s6.9.f), we don't have any predefined 960 // library functions like 'malloc'. Instead, we'll just error. 961 if ((getLangOpts().CPlusPlus || getLangOpts().OpenCL) && 962 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 963 return false; 964 965 if (NamedDecl *D = 966 LazilyCreateBuiltin(II, BuiltinID, TUScope, 967 R.isForRedeclaration(), R.getNameLoc())) { 968 R.addDecl(D); 969 return true; 970 } 971 } 972 } 973 } 974 975 return false; 976 } 977 978 /// Looks up the declaration of "struct objc_super" and 979 /// saves it for later use in building builtin declaration of 980 /// objc_msgSendSuper and objc_msgSendSuper_stret. 981 static void LookupPredefedObjCSuperType(Sema &Sema, Scope *S) { 982 ASTContext &Context = Sema.Context; 983 LookupResult Result(Sema, &Context.Idents.get("objc_super"), SourceLocation(), 984 Sema::LookupTagName); 985 Sema.LookupName(Result, S); 986 if (Result.getResultKind() == LookupResult::Found) 987 if (const TagDecl *TD = Result.getAsSingle<TagDecl>()) 988 Context.setObjCSuperType(Context.getTagDeclType(TD)); 989 } 990 991 void Sema::LookupNecessaryTypesForBuiltin(Scope *S, unsigned ID) { 992 if (ID == Builtin::BIobjc_msgSendSuper) 993 LookupPredefedObjCSuperType(*this, S); 994 } 995 996 /// Determine whether we can declare a special member function within 997 /// the class at this point. 998 static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) { 999 // We need to have a definition for the class. 1000 if (!Class->getDefinition() || Class->isDependentContext()) 1001 return false; 1002 1003 // We can't be in the middle of defining the class. 1004 return !Class->isBeingDefined(); 1005 } 1006 1007 void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) { 1008 if (!CanDeclareSpecialMemberFunction(Class)) 1009 return; 1010 1011 // If the default constructor has not yet been declared, do so now. 1012 if (Class->needsImplicitDefaultConstructor()) 1013 DeclareImplicitDefaultConstructor(Class); 1014 1015 // If the copy constructor has not yet been declared, do so now. 1016 if (Class->needsImplicitCopyConstructor()) 1017 DeclareImplicitCopyConstructor(Class); 1018 1019 // If the copy assignment operator has not yet been declared, do so now. 1020 if (Class->needsImplicitCopyAssignment()) 1021 DeclareImplicitCopyAssignment(Class); 1022 1023 if (getLangOpts().CPlusPlus11) { 1024 // If the move constructor has not yet been declared, do so now. 1025 if (Class->needsImplicitMoveConstructor()) 1026 DeclareImplicitMoveConstructor(Class); 1027 1028 // If the move assignment operator has not yet been declared, do so now. 1029 if (Class->needsImplicitMoveAssignment()) 1030 DeclareImplicitMoveAssignment(Class); 1031 } 1032 1033 // If the destructor has not yet been declared, do so now. 1034 if (Class->needsImplicitDestructor()) 1035 DeclareImplicitDestructor(Class); 1036 } 1037 1038 /// Determine whether this is the name of an implicitly-declared 1039 /// special member function. 1040 static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) { 1041 switch (Name.getNameKind()) { 1042 case DeclarationName::CXXConstructorName: 1043 case DeclarationName::CXXDestructorName: 1044 return true; 1045 1046 case DeclarationName::CXXOperatorName: 1047 return Name.getCXXOverloadedOperator() == OO_Equal; 1048 1049 default: 1050 break; 1051 } 1052 1053 return false; 1054 } 1055 1056 /// If there are any implicit member functions with the given name 1057 /// that need to be declared in the given declaration context, do so. 1058 static void DeclareImplicitMemberFunctionsWithName(Sema &S, 1059 DeclarationName Name, 1060 SourceLocation Loc, 1061 const DeclContext *DC) { 1062 if (!DC) 1063 return; 1064 1065 switch (Name.getNameKind()) { 1066 case DeclarationName::CXXConstructorName: 1067 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) 1068 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) { 1069 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record); 1070 if (Record->needsImplicitDefaultConstructor()) 1071 S.DeclareImplicitDefaultConstructor(Class); 1072 if (Record->needsImplicitCopyConstructor()) 1073 S.DeclareImplicitCopyConstructor(Class); 1074 if (S.getLangOpts().CPlusPlus11 && 1075 Record->needsImplicitMoveConstructor()) 1076 S.DeclareImplicitMoveConstructor(Class); 1077 } 1078 break; 1079 1080 case DeclarationName::CXXDestructorName: 1081 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) 1082 if (Record->getDefinition() && Record->needsImplicitDestructor() && 1083 CanDeclareSpecialMemberFunction(Record)) 1084 S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record)); 1085 break; 1086 1087 case DeclarationName::CXXOperatorName: 1088 if (Name.getCXXOverloadedOperator() != OO_Equal) 1089 break; 1090 1091 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) { 1092 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) { 1093 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record); 1094 if (Record->needsImplicitCopyAssignment()) 1095 S.DeclareImplicitCopyAssignment(Class); 1096 if (S.getLangOpts().CPlusPlus11 && 1097 Record->needsImplicitMoveAssignment()) 1098 S.DeclareImplicitMoveAssignment(Class); 1099 } 1100 } 1101 break; 1102 1103 case DeclarationName::CXXDeductionGuideName: 1104 S.DeclareImplicitDeductionGuides(Name.getCXXDeductionGuideTemplate(), Loc); 1105 break; 1106 1107 default: 1108 break; 1109 } 1110 } 1111 1112 // Adds all qualifying matches for a name within a decl context to the 1113 // given lookup result. Returns true if any matches were found. 1114 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) { 1115 bool Found = false; 1116 1117 // Lazily declare C++ special member functions. 1118 if (S.getLangOpts().CPlusPlus) 1119 DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), R.getNameLoc(), 1120 DC); 1121 1122 // Perform lookup into this declaration context. 1123 DeclContext::lookup_result DR = DC->lookup(R.getLookupName()); 1124 for (NamedDecl *D : DR) { 1125 if ((D = R.getAcceptableDecl(D))) { 1126 R.addDecl(D); 1127 Found = true; 1128 } 1129 } 1130 1131 if (!Found && DC->isTranslationUnit() && S.LookupBuiltin(R)) 1132 return true; 1133 1134 if (R.getLookupName().getNameKind() 1135 != DeclarationName::CXXConversionFunctionName || 1136 R.getLookupName().getCXXNameType()->isDependentType() || 1137 !isa<CXXRecordDecl>(DC)) 1138 return Found; 1139 1140 // C++ [temp.mem]p6: 1141 // A specialization of a conversion function template is not found by 1142 // name lookup. Instead, any conversion function templates visible in the 1143 // context of the use are considered. [...] 1144 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC); 1145 if (!Record->isCompleteDefinition()) 1146 return Found; 1147 1148 // For conversion operators, 'operator auto' should only match 1149 // 'operator auto'. Since 'auto' is not a type, it shouldn't be considered 1150 // as a candidate for template substitution. 1151 auto *ContainedDeducedType = 1152 R.getLookupName().getCXXNameType()->getContainedDeducedType(); 1153 if (R.getLookupName().getNameKind() == 1154 DeclarationName::CXXConversionFunctionName && 1155 ContainedDeducedType && ContainedDeducedType->isUndeducedType()) 1156 return Found; 1157 1158 for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(), 1159 UEnd = Record->conversion_end(); U != UEnd; ++U) { 1160 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U); 1161 if (!ConvTemplate) 1162 continue; 1163 1164 // When we're performing lookup for the purposes of redeclaration, just 1165 // add the conversion function template. When we deduce template 1166 // arguments for specializations, we'll end up unifying the return 1167 // type of the new declaration with the type of the function template. 1168 if (R.isForRedeclaration()) { 1169 R.addDecl(ConvTemplate); 1170 Found = true; 1171 continue; 1172 } 1173 1174 // C++ [temp.mem]p6: 1175 // [...] For each such operator, if argument deduction succeeds 1176 // (14.9.2.3), the resulting specialization is used as if found by 1177 // name lookup. 1178 // 1179 // When referencing a conversion function for any purpose other than 1180 // a redeclaration (such that we'll be building an expression with the 1181 // result), perform template argument deduction and place the 1182 // specialization into the result set. We do this to avoid forcing all 1183 // callers to perform special deduction for conversion functions. 1184 TemplateDeductionInfo Info(R.getNameLoc()); 1185 FunctionDecl *Specialization = nullptr; 1186 1187 const FunctionProtoType *ConvProto 1188 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>(); 1189 assert(ConvProto && "Nonsensical conversion function template type"); 1190 1191 // Compute the type of the function that we would expect the conversion 1192 // function to have, if it were to match the name given. 1193 // FIXME: Calling convention! 1194 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo(); 1195 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C); 1196 EPI.ExceptionSpec = EST_None; 1197 QualType ExpectedType = R.getSema().Context.getFunctionType( 1198 R.getLookupName().getCXXNameType(), std::nullopt, EPI); 1199 1200 // Perform template argument deduction against the type that we would 1201 // expect the function to have. 1202 if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType, 1203 Specialization, Info) 1204 == Sema::TDK_Success) { 1205 R.addDecl(Specialization); 1206 Found = true; 1207 } 1208 } 1209 1210 return Found; 1211 } 1212 1213 // Performs C++ unqualified lookup into the given file context. 1214 static bool CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context, 1215 const DeclContext *NS, 1216 UnqualUsingDirectiveSet &UDirs) { 1217 1218 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!"); 1219 1220 // Perform direct name lookup into the LookupCtx. 1221 bool Found = LookupDirect(S, R, NS); 1222 1223 // Perform direct name lookup into the namespaces nominated by the 1224 // using directives whose common ancestor is this namespace. 1225 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS)) 1226 if (LookupDirect(S, R, UUE.getNominatedNamespace())) 1227 Found = true; 1228 1229 R.resolveKind(); 1230 1231 return Found; 1232 } 1233 1234 static bool isNamespaceOrTranslationUnitScope(Scope *S) { 1235 if (DeclContext *Ctx = S->getEntity()) 1236 return Ctx->isFileContext(); 1237 return false; 1238 } 1239 1240 /// Find the outer declaration context from this scope. This indicates the 1241 /// context that we should search up to (exclusive) before considering the 1242 /// parent of the specified scope. 1243 static DeclContext *findOuterContext(Scope *S) { 1244 for (Scope *OuterS = S->getParent(); OuterS; OuterS = OuterS->getParent()) 1245 if (DeclContext *DC = OuterS->getLookupEntity()) 1246 return DC; 1247 return nullptr; 1248 } 1249 1250 namespace { 1251 /// An RAII object to specify that we want to find block scope extern 1252 /// declarations. 1253 struct FindLocalExternScope { 1254 FindLocalExternScope(LookupResult &R) 1255 : R(R), OldFindLocalExtern(R.getIdentifierNamespace() & 1256 Decl::IDNS_LocalExtern) { 1257 R.setFindLocalExtern(R.getIdentifierNamespace() & 1258 (Decl::IDNS_Ordinary | Decl::IDNS_NonMemberOperator)); 1259 } 1260 void restore() { 1261 R.setFindLocalExtern(OldFindLocalExtern); 1262 } 1263 ~FindLocalExternScope() { 1264 restore(); 1265 } 1266 LookupResult &R; 1267 bool OldFindLocalExtern; 1268 }; 1269 } // end anonymous namespace 1270 1271 bool Sema::CppLookupName(LookupResult &R, Scope *S) { 1272 assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup"); 1273 1274 DeclarationName Name = R.getLookupName(); 1275 Sema::LookupNameKind NameKind = R.getLookupKind(); 1276 1277 // If this is the name of an implicitly-declared special member function, 1278 // go through the scope stack to implicitly declare 1279 if (isImplicitlyDeclaredMemberFunctionName(Name)) { 1280 for (Scope *PreS = S; PreS; PreS = PreS->getParent()) 1281 if (DeclContext *DC = PreS->getEntity()) 1282 DeclareImplicitMemberFunctionsWithName(*this, Name, R.getNameLoc(), DC); 1283 } 1284 1285 // Implicitly declare member functions with the name we're looking for, if in 1286 // fact we are in a scope where it matters. 1287 1288 Scope *Initial = S; 1289 IdentifierResolver::iterator 1290 I = IdResolver.begin(Name), 1291 IEnd = IdResolver.end(); 1292 1293 // First we lookup local scope. 1294 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir] 1295 // ...During unqualified name lookup (3.4.1), the names appear as if 1296 // they were declared in the nearest enclosing namespace which contains 1297 // both the using-directive and the nominated namespace. 1298 // [Note: in this context, "contains" means "contains directly or 1299 // indirectly". 1300 // 1301 // For example: 1302 // namespace A { int i; } 1303 // void foo() { 1304 // int i; 1305 // { 1306 // using namespace A; 1307 // ++i; // finds local 'i', A::i appears at global scope 1308 // } 1309 // } 1310 // 1311 UnqualUsingDirectiveSet UDirs(*this); 1312 bool VisitedUsingDirectives = false; 1313 bool LeftStartingScope = false; 1314 1315 // When performing a scope lookup, we want to find local extern decls. 1316 FindLocalExternScope FindLocals(R); 1317 1318 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) { 1319 bool SearchNamespaceScope = true; 1320 // Check whether the IdResolver has anything in this scope. 1321 for (; I != IEnd && S->isDeclScope(*I); ++I) { 1322 if (NamedDecl *ND = R.getAcceptableDecl(*I)) { 1323 if (NameKind == LookupRedeclarationWithLinkage && 1324 !(*I)->isTemplateParameter()) { 1325 // If it's a template parameter, we still find it, so we can diagnose 1326 // the invalid redeclaration. 1327 1328 // Determine whether this (or a previous) declaration is 1329 // out-of-scope. 1330 if (!LeftStartingScope && !Initial->isDeclScope(*I)) 1331 LeftStartingScope = true; 1332 1333 // If we found something outside of our starting scope that 1334 // does not have linkage, skip it. 1335 if (LeftStartingScope && !((*I)->hasLinkage())) { 1336 R.setShadowed(); 1337 continue; 1338 } 1339 } else { 1340 // We found something in this scope, we should not look at the 1341 // namespace scope 1342 SearchNamespaceScope = false; 1343 } 1344 R.addDecl(ND); 1345 } 1346 } 1347 if (!SearchNamespaceScope) { 1348 R.resolveKind(); 1349 if (S->isClassScope()) 1350 if (auto *Record = dyn_cast_if_present<CXXRecordDecl>(S->getEntity())) 1351 R.setNamingClass(Record); 1352 return true; 1353 } 1354 1355 if (NameKind == LookupLocalFriendName && !S->isClassScope()) { 1356 // C++11 [class.friend]p11: 1357 // If a friend declaration appears in a local class and the name 1358 // specified is an unqualified name, a prior declaration is 1359 // looked up without considering scopes that are outside the 1360 // innermost enclosing non-class scope. 1361 return false; 1362 } 1363 1364 if (DeclContext *Ctx = S->getLookupEntity()) { 1365 DeclContext *OuterCtx = findOuterContext(S); 1366 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 1367 // We do not directly look into transparent contexts, since 1368 // those entities will be found in the nearest enclosing 1369 // non-transparent context. 1370 if (Ctx->isTransparentContext()) 1371 continue; 1372 1373 // We do not look directly into function or method contexts, 1374 // since all of the local variables and parameters of the 1375 // function/method are present within the Scope. 1376 if (Ctx->isFunctionOrMethod()) { 1377 // If we have an Objective-C instance method, look for ivars 1378 // in the corresponding interface. 1379 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 1380 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo()) 1381 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) { 1382 ObjCInterfaceDecl *ClassDeclared; 1383 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable( 1384 Name.getAsIdentifierInfo(), 1385 ClassDeclared)) { 1386 if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) { 1387 R.addDecl(ND); 1388 R.resolveKind(); 1389 return true; 1390 } 1391 } 1392 } 1393 } 1394 1395 continue; 1396 } 1397 1398 // If this is a file context, we need to perform unqualified name 1399 // lookup considering using directives. 1400 if (Ctx->isFileContext()) { 1401 // If we haven't handled using directives yet, do so now. 1402 if (!VisitedUsingDirectives) { 1403 // Add using directives from this context up to the top level. 1404 for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) { 1405 if (UCtx->isTransparentContext()) 1406 continue; 1407 1408 UDirs.visit(UCtx, UCtx); 1409 } 1410 1411 // Find the innermost file scope, so we can add using directives 1412 // from local scopes. 1413 Scope *InnermostFileScope = S; 1414 while (InnermostFileScope && 1415 !isNamespaceOrTranslationUnitScope(InnermostFileScope)) 1416 InnermostFileScope = InnermostFileScope->getParent(); 1417 UDirs.visitScopeChain(Initial, InnermostFileScope); 1418 1419 UDirs.done(); 1420 1421 VisitedUsingDirectives = true; 1422 } 1423 1424 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) { 1425 R.resolveKind(); 1426 return true; 1427 } 1428 1429 continue; 1430 } 1431 1432 // Perform qualified name lookup into this context. 1433 // FIXME: In some cases, we know that every name that could be found by 1434 // this qualified name lookup will also be on the identifier chain. For 1435 // example, inside a class without any base classes, we never need to 1436 // perform qualified lookup because all of the members are on top of the 1437 // identifier chain. 1438 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true)) 1439 return true; 1440 } 1441 } 1442 } 1443 1444 // Stop if we ran out of scopes. 1445 // FIXME: This really, really shouldn't be happening. 1446 if (!S) return false; 1447 1448 // If we are looking for members, no need to look into global/namespace scope. 1449 if (NameKind == LookupMemberName) 1450 return false; 1451 1452 // Collect UsingDirectiveDecls in all scopes, and recursively all 1453 // nominated namespaces by those using-directives. 1454 // 1455 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we 1456 // don't build it for each lookup! 1457 if (!VisitedUsingDirectives) { 1458 UDirs.visitScopeChain(Initial, S); 1459 UDirs.done(); 1460 } 1461 1462 // If we're not performing redeclaration lookup, do not look for local 1463 // extern declarations outside of a function scope. 1464 if (!R.isForRedeclaration()) 1465 FindLocals.restore(); 1466 1467 // Lookup namespace scope, and global scope. 1468 // Unqualified name lookup in C++ requires looking into scopes 1469 // that aren't strictly lexical, and therefore we walk through the 1470 // context as well as walking through the scopes. 1471 for (; S; S = S->getParent()) { 1472 // Check whether the IdResolver has anything in this scope. 1473 bool Found = false; 1474 for (; I != IEnd && S->isDeclScope(*I); ++I) { 1475 if (NamedDecl *ND = R.getAcceptableDecl(*I)) { 1476 // We found something. Look for anything else in our scope 1477 // with this same name and in an acceptable identifier 1478 // namespace, so that we can construct an overload set if we 1479 // need to. 1480 Found = true; 1481 R.addDecl(ND); 1482 } 1483 } 1484 1485 if (Found && S->isTemplateParamScope()) { 1486 R.resolveKind(); 1487 return true; 1488 } 1489 1490 DeclContext *Ctx = S->getLookupEntity(); 1491 if (Ctx) { 1492 DeclContext *OuterCtx = findOuterContext(S); 1493 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 1494 // We do not directly look into transparent contexts, since 1495 // those entities will be found in the nearest enclosing 1496 // non-transparent context. 1497 if (Ctx->isTransparentContext()) 1498 continue; 1499 1500 // If we have a context, and it's not a context stashed in the 1501 // template parameter scope for an out-of-line definition, also 1502 // look into that context. 1503 if (!(Found && S->isTemplateParamScope())) { 1504 assert(Ctx->isFileContext() && 1505 "We should have been looking only at file context here already."); 1506 1507 // Look into context considering using-directives. 1508 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) 1509 Found = true; 1510 } 1511 1512 if (Found) { 1513 R.resolveKind(); 1514 return true; 1515 } 1516 1517 if (R.isForRedeclaration() && !Ctx->isTransparentContext()) 1518 return false; 1519 } 1520 } 1521 1522 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext()) 1523 return false; 1524 } 1525 1526 return !R.empty(); 1527 } 1528 1529 void Sema::makeMergedDefinitionVisible(NamedDecl *ND) { 1530 if (auto *M = getCurrentModule()) 1531 Context.mergeDefinitionIntoModule(ND, M); 1532 else 1533 // We're not building a module; just make the definition visible. 1534 ND->setVisibleDespiteOwningModule(); 1535 1536 // If ND is a template declaration, make the template parameters 1537 // visible too. They're not (necessarily) within a mergeable DeclContext. 1538 if (auto *TD = dyn_cast<TemplateDecl>(ND)) 1539 for (auto *Param : *TD->getTemplateParameters()) 1540 makeMergedDefinitionVisible(Param); 1541 } 1542 1543 /// Find the module in which the given declaration was defined. 1544 static Module *getDefiningModule(Sema &S, Decl *Entity) { 1545 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) { 1546 // If this function was instantiated from a template, the defining module is 1547 // the module containing the pattern. 1548 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern()) 1549 Entity = Pattern; 1550 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) { 1551 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern()) 1552 Entity = Pattern; 1553 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) { 1554 if (auto *Pattern = ED->getTemplateInstantiationPattern()) 1555 Entity = Pattern; 1556 } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) { 1557 if (VarDecl *Pattern = VD->getTemplateInstantiationPattern()) 1558 Entity = Pattern; 1559 } 1560 1561 // Walk up to the containing context. That might also have been instantiated 1562 // from a template. 1563 DeclContext *Context = Entity->getLexicalDeclContext(); 1564 if (Context->isFileContext()) 1565 return S.getOwningModule(Entity); 1566 return getDefiningModule(S, cast<Decl>(Context)); 1567 } 1568 1569 llvm::DenseSet<Module*> &Sema::getLookupModules() { 1570 unsigned N = CodeSynthesisContexts.size(); 1571 for (unsigned I = CodeSynthesisContextLookupModules.size(); 1572 I != N; ++I) { 1573 Module *M = CodeSynthesisContexts[I].Entity ? 1574 getDefiningModule(*this, CodeSynthesisContexts[I].Entity) : 1575 nullptr; 1576 if (M && !LookupModulesCache.insert(M).second) 1577 M = nullptr; 1578 CodeSynthesisContextLookupModules.push_back(M); 1579 } 1580 return LookupModulesCache; 1581 } 1582 1583 /// Determine if we could use all the declarations in the module. 1584 bool Sema::isUsableModule(const Module *M) { 1585 assert(M && "We shouldn't check nullness for module here"); 1586 // Return quickly if we cached the result. 1587 if (UsableModuleUnitsCache.count(M)) 1588 return true; 1589 1590 // If M is the global module fragment of the current translation unit. So it 1591 // should be usable. 1592 // [module.global.frag]p1: 1593 // The global module fragment can be used to provide declarations that are 1594 // attached to the global module and usable within the module unit. 1595 if (M == TheGlobalModuleFragment || M == TheImplicitGlobalModuleFragment || 1596 // If M is the module we're parsing, it should be usable. This covers the 1597 // private module fragment. The private module fragment is usable only if 1598 // it is within the current module unit. And it must be the current 1599 // parsing module unit if it is within the current module unit according 1600 // to the grammar of the private module fragment. NOTE: This is covered by 1601 // the following condition. The intention of the check is to avoid string 1602 // comparison as much as possible. 1603 M == getCurrentModule() || 1604 // The module unit which is in the same module with the current module 1605 // unit is usable. 1606 // 1607 // FIXME: Here we judge if they are in the same module by comparing the 1608 // string. Is there any better solution? 1609 M->getPrimaryModuleInterfaceName() == 1610 llvm::StringRef(getLangOpts().CurrentModule).split(':').first) { 1611 UsableModuleUnitsCache.insert(M); 1612 return true; 1613 } 1614 1615 return false; 1616 } 1617 1618 bool Sema::hasVisibleMergedDefinition(const NamedDecl *Def) { 1619 for (const Module *Merged : Context.getModulesWithMergedDefinition(Def)) 1620 if (isModuleVisible(Merged)) 1621 return true; 1622 return false; 1623 } 1624 1625 bool Sema::hasMergedDefinitionInCurrentModule(const NamedDecl *Def) { 1626 for (const Module *Merged : Context.getModulesWithMergedDefinition(Def)) 1627 if (isUsableModule(Merged)) 1628 return true; 1629 return false; 1630 } 1631 1632 template <typename ParmDecl> 1633 static bool 1634 hasAcceptableDefaultArgument(Sema &S, const ParmDecl *D, 1635 llvm::SmallVectorImpl<Module *> *Modules, 1636 Sema::AcceptableKind Kind) { 1637 if (!D->hasDefaultArgument()) 1638 return false; 1639 1640 llvm::SmallPtrSet<const ParmDecl *, 4> Visited; 1641 while (D && Visited.insert(D).second) { 1642 auto &DefaultArg = D->getDefaultArgStorage(); 1643 if (!DefaultArg.isInherited() && S.isAcceptable(D, Kind)) 1644 return true; 1645 1646 if (!DefaultArg.isInherited() && Modules) { 1647 auto *NonConstD = const_cast<ParmDecl*>(D); 1648 Modules->push_back(S.getOwningModule(NonConstD)); 1649 } 1650 1651 // If there was a previous default argument, maybe its parameter is 1652 // acceptable. 1653 D = DefaultArg.getInheritedFrom(); 1654 } 1655 return false; 1656 } 1657 1658 bool Sema::hasAcceptableDefaultArgument( 1659 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules, 1660 Sema::AcceptableKind Kind) { 1661 if (auto *P = dyn_cast<TemplateTypeParmDecl>(D)) 1662 return ::hasAcceptableDefaultArgument(*this, P, Modules, Kind); 1663 1664 if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D)) 1665 return ::hasAcceptableDefaultArgument(*this, P, Modules, Kind); 1666 1667 return ::hasAcceptableDefaultArgument( 1668 *this, cast<TemplateTemplateParmDecl>(D), Modules, Kind); 1669 } 1670 1671 bool Sema::hasVisibleDefaultArgument(const NamedDecl *D, 1672 llvm::SmallVectorImpl<Module *> *Modules) { 1673 return hasAcceptableDefaultArgument(D, Modules, 1674 Sema::AcceptableKind::Visible); 1675 } 1676 1677 bool Sema::hasReachableDefaultArgument( 1678 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1679 return hasAcceptableDefaultArgument(D, Modules, 1680 Sema::AcceptableKind::Reachable); 1681 } 1682 1683 template <typename Filter> 1684 static bool 1685 hasAcceptableDeclarationImpl(Sema &S, const NamedDecl *D, 1686 llvm::SmallVectorImpl<Module *> *Modules, Filter F, 1687 Sema::AcceptableKind Kind) { 1688 bool HasFilteredRedecls = false; 1689 1690 for (auto *Redecl : D->redecls()) { 1691 auto *R = cast<NamedDecl>(Redecl); 1692 if (!F(R)) 1693 continue; 1694 1695 if (S.isAcceptable(R, Kind)) 1696 return true; 1697 1698 HasFilteredRedecls = true; 1699 1700 if (Modules) 1701 Modules->push_back(R->getOwningModule()); 1702 } 1703 1704 // Only return false if there is at least one redecl that is not filtered out. 1705 if (HasFilteredRedecls) 1706 return false; 1707 1708 return true; 1709 } 1710 1711 static bool 1712 hasAcceptableExplicitSpecialization(Sema &S, const NamedDecl *D, 1713 llvm::SmallVectorImpl<Module *> *Modules, 1714 Sema::AcceptableKind Kind) { 1715 return hasAcceptableDeclarationImpl( 1716 S, D, Modules, 1717 [](const NamedDecl *D) { 1718 if (auto *RD = dyn_cast<CXXRecordDecl>(D)) 1719 return RD->getTemplateSpecializationKind() == 1720 TSK_ExplicitSpecialization; 1721 if (auto *FD = dyn_cast<FunctionDecl>(D)) 1722 return FD->getTemplateSpecializationKind() == 1723 TSK_ExplicitSpecialization; 1724 if (auto *VD = dyn_cast<VarDecl>(D)) 1725 return VD->getTemplateSpecializationKind() == 1726 TSK_ExplicitSpecialization; 1727 llvm_unreachable("unknown explicit specialization kind"); 1728 }, 1729 Kind); 1730 } 1731 1732 bool Sema::hasVisibleExplicitSpecialization( 1733 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1734 return ::hasAcceptableExplicitSpecialization(*this, D, Modules, 1735 Sema::AcceptableKind::Visible); 1736 } 1737 1738 bool Sema::hasReachableExplicitSpecialization( 1739 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1740 return ::hasAcceptableExplicitSpecialization(*this, D, Modules, 1741 Sema::AcceptableKind::Reachable); 1742 } 1743 1744 static bool 1745 hasAcceptableMemberSpecialization(Sema &S, const NamedDecl *D, 1746 llvm::SmallVectorImpl<Module *> *Modules, 1747 Sema::AcceptableKind Kind) { 1748 assert(isa<CXXRecordDecl>(D->getDeclContext()) && 1749 "not a member specialization"); 1750 return hasAcceptableDeclarationImpl( 1751 S, D, Modules, 1752 [](const NamedDecl *D) { 1753 // If the specialization is declared at namespace scope, then it's a 1754 // member specialization declaration. If it's lexically inside the class 1755 // definition then it was instantiated. 1756 // 1757 // FIXME: This is a hack. There should be a better way to determine 1758 // this. 1759 // FIXME: What about MS-style explicit specializations declared within a 1760 // class definition? 1761 return D->getLexicalDeclContext()->isFileContext(); 1762 }, 1763 Kind); 1764 } 1765 1766 bool Sema::hasVisibleMemberSpecialization( 1767 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1768 return hasAcceptableMemberSpecialization(*this, D, Modules, 1769 Sema::AcceptableKind::Visible); 1770 } 1771 1772 bool Sema::hasReachableMemberSpecialization( 1773 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1774 return hasAcceptableMemberSpecialization(*this, D, Modules, 1775 Sema::AcceptableKind::Reachable); 1776 } 1777 1778 /// Determine whether a declaration is acceptable to name lookup. 1779 /// 1780 /// This routine determines whether the declaration D is acceptable in the 1781 /// current lookup context, taking into account the current template 1782 /// instantiation stack. During template instantiation, a declaration is 1783 /// acceptable if it is acceptable from a module containing any entity on the 1784 /// template instantiation path (by instantiating a template, you allow it to 1785 /// see the declarations that your module can see, including those later on in 1786 /// your module). 1787 bool LookupResult::isAcceptableSlow(Sema &SemaRef, NamedDecl *D, 1788 Sema::AcceptableKind Kind) { 1789 assert(!D->isUnconditionallyVisible() && 1790 "should not call this: not in slow case"); 1791 1792 Module *DeclModule = SemaRef.getOwningModule(D); 1793 assert(DeclModule && "hidden decl has no owning module"); 1794 1795 // If the owning module is visible, the decl is acceptable. 1796 if (SemaRef.isModuleVisible(DeclModule, 1797 D->isInvisibleOutsideTheOwningModule())) 1798 return true; 1799 1800 // Determine whether a decl context is a file context for the purpose of 1801 // visibility/reachability. This looks through some (export and linkage spec) 1802 // transparent contexts, but not others (enums). 1803 auto IsEffectivelyFileContext = [](const DeclContext *DC) { 1804 return DC->isFileContext() || isa<LinkageSpecDecl>(DC) || 1805 isa<ExportDecl>(DC); 1806 }; 1807 1808 // If this declaration is not at namespace scope 1809 // then it is acceptable if its lexical parent has a acceptable definition. 1810 DeclContext *DC = D->getLexicalDeclContext(); 1811 if (DC && !IsEffectivelyFileContext(DC)) { 1812 // For a parameter, check whether our current template declaration's 1813 // lexical context is acceptable, not whether there's some other acceptable 1814 // definition of it, because parameters aren't "within" the definition. 1815 // 1816 // In C++ we need to check for a acceptable definition due to ODR merging, 1817 // and in C we must not because each declaration of a function gets its own 1818 // set of declarations for tags in prototype scope. 1819 bool AcceptableWithinParent; 1820 if (D->isTemplateParameter()) { 1821 bool SearchDefinitions = true; 1822 if (const auto *DCD = dyn_cast<Decl>(DC)) { 1823 if (const auto *TD = DCD->getDescribedTemplate()) { 1824 TemplateParameterList *TPL = TD->getTemplateParameters(); 1825 auto Index = getDepthAndIndex(D).second; 1826 SearchDefinitions = Index >= TPL->size() || TPL->getParam(Index) != D; 1827 } 1828 } 1829 if (SearchDefinitions) 1830 AcceptableWithinParent = 1831 SemaRef.hasAcceptableDefinition(cast<NamedDecl>(DC), Kind); 1832 else 1833 AcceptableWithinParent = 1834 isAcceptable(SemaRef, cast<NamedDecl>(DC), Kind); 1835 } else if (isa<ParmVarDecl>(D) || 1836 (isa<FunctionDecl>(DC) && !SemaRef.getLangOpts().CPlusPlus)) 1837 AcceptableWithinParent = isAcceptable(SemaRef, cast<NamedDecl>(DC), Kind); 1838 else if (D->isModulePrivate()) { 1839 // A module-private declaration is only acceptable if an enclosing lexical 1840 // parent was merged with another definition in the current module. 1841 AcceptableWithinParent = false; 1842 do { 1843 if (SemaRef.hasMergedDefinitionInCurrentModule(cast<NamedDecl>(DC))) { 1844 AcceptableWithinParent = true; 1845 break; 1846 } 1847 DC = DC->getLexicalParent(); 1848 } while (!IsEffectivelyFileContext(DC)); 1849 } else { 1850 AcceptableWithinParent = 1851 SemaRef.hasAcceptableDefinition(cast<NamedDecl>(DC), Kind); 1852 } 1853 1854 if (AcceptableWithinParent && SemaRef.CodeSynthesisContexts.empty() && 1855 Kind == Sema::AcceptableKind::Visible && 1856 // FIXME: Do something better in this case. 1857 !SemaRef.getLangOpts().ModulesLocalVisibility) { 1858 // Cache the fact that this declaration is implicitly visible because 1859 // its parent has a visible definition. 1860 D->setVisibleDespiteOwningModule(); 1861 } 1862 return AcceptableWithinParent; 1863 } 1864 1865 if (Kind == Sema::AcceptableKind::Visible) 1866 return false; 1867 1868 assert(Kind == Sema::AcceptableKind::Reachable && 1869 "Additional Sema::AcceptableKind?"); 1870 return isReachableSlow(SemaRef, D); 1871 } 1872 1873 bool Sema::isModuleVisible(const Module *M, bool ModulePrivate) { 1874 // The module might be ordinarily visible. For a module-private query, that 1875 // means it is part of the current module. 1876 if (ModulePrivate && isUsableModule(M)) 1877 return true; 1878 1879 // For a query which is not module-private, that means it is in our visible 1880 // module set. 1881 if (!ModulePrivate && VisibleModules.isVisible(M)) 1882 return true; 1883 1884 // Otherwise, it might be visible by virtue of the query being within a 1885 // template instantiation or similar that is permitted to look inside M. 1886 1887 // Find the extra places where we need to look. 1888 const auto &LookupModules = getLookupModules(); 1889 if (LookupModules.empty()) 1890 return false; 1891 1892 // If our lookup set contains the module, it's visible. 1893 if (LookupModules.count(M)) 1894 return true; 1895 1896 // The global module fragments are visible to its corresponding module unit. 1897 // So the global module fragment should be visible if the its corresponding 1898 // module unit is visible. 1899 if (M->isGlobalModule() && LookupModules.count(M->getTopLevelModule())) 1900 return true; 1901 1902 // For a module-private query, that's everywhere we get to look. 1903 if (ModulePrivate) 1904 return false; 1905 1906 // Check whether M is transitively exported to an import of the lookup set. 1907 return llvm::any_of(LookupModules, [&](const Module *LookupM) { 1908 return LookupM->isModuleVisible(M); 1909 }); 1910 } 1911 1912 // FIXME: Return false directly if we don't have an interface dependency on the 1913 // translation unit containing D. 1914 bool LookupResult::isReachableSlow(Sema &SemaRef, NamedDecl *D) { 1915 assert(!isVisible(SemaRef, D) && "Shouldn't call the slow case.\n"); 1916 1917 Module *DeclModule = SemaRef.getOwningModule(D); 1918 assert(DeclModule && "hidden decl has no owning module"); 1919 1920 // Entities in header like modules are reachable only if they're visible. 1921 if (DeclModule->isHeaderLikeModule()) 1922 return false; 1923 1924 if (!D->isInAnotherModuleUnit()) 1925 return true; 1926 1927 // [module.reach]/p3: 1928 // A declaration D is reachable from a point P if: 1929 // ... 1930 // - D is not discarded ([module.global.frag]), appears in a translation unit 1931 // that is reachable from P, and does not appear within a private module 1932 // fragment. 1933 // 1934 // A declaration that's discarded in the GMF should be module-private. 1935 if (D->isModulePrivate()) 1936 return false; 1937 1938 // [module.reach]/p1 1939 // A translation unit U is necessarily reachable from a point P if U is a 1940 // module interface unit on which the translation unit containing P has an 1941 // interface dependency, or the translation unit containing P imports U, in 1942 // either case prior to P ([module.import]). 1943 // 1944 // [module.import]/p10 1945 // A translation unit has an interface dependency on a translation unit U if 1946 // it contains a declaration (possibly a module-declaration) that imports U 1947 // or if it has an interface dependency on a translation unit that has an 1948 // interface dependency on U. 1949 // 1950 // So we could conclude the module unit U is necessarily reachable if: 1951 // (1) The module unit U is module interface unit. 1952 // (2) The current unit has an interface dependency on the module unit U. 1953 // 1954 // Here we only check for the first condition. Since we couldn't see 1955 // DeclModule if it isn't (transitively) imported. 1956 if (DeclModule->getTopLevelModule()->isModuleInterfaceUnit()) 1957 return true; 1958 1959 // [module.reach]/p2 1960 // Additional translation units on 1961 // which the point within the program has an interface dependency may be 1962 // considered reachable, but it is unspecified which are and under what 1963 // circumstances. 1964 // 1965 // The decision here is to treat all additional tranditional units as 1966 // unreachable. 1967 return false; 1968 } 1969 1970 bool Sema::isAcceptableSlow(const NamedDecl *D, Sema::AcceptableKind Kind) { 1971 return LookupResult::isAcceptable(*this, const_cast<NamedDecl *>(D), Kind); 1972 } 1973 1974 bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) { 1975 // FIXME: If there are both visible and hidden declarations, we need to take 1976 // into account whether redeclaration is possible. Example: 1977 // 1978 // Non-imported module: 1979 // int f(T); // #1 1980 // Some TU: 1981 // static int f(U); // #2, not a redeclaration of #1 1982 // int f(T); // #3, finds both, should link with #1 if T != U, but 1983 // // with #2 if T == U; neither should be ambiguous. 1984 for (auto *D : R) { 1985 if (isVisible(D)) 1986 return true; 1987 assert(D->isExternallyDeclarable() && 1988 "should not have hidden, non-externally-declarable result here"); 1989 } 1990 1991 // This function is called once "New" is essentially complete, but before a 1992 // previous declaration is attached. We can't query the linkage of "New" in 1993 // general, because attaching the previous declaration can change the 1994 // linkage of New to match the previous declaration. 1995 // 1996 // However, because we've just determined that there is no *visible* prior 1997 // declaration, we can compute the linkage here. There are two possibilities: 1998 // 1999 // * This is not a redeclaration; it's safe to compute the linkage now. 2000 // 2001 // * This is a redeclaration of a prior declaration that is externally 2002 // redeclarable. In that case, the linkage of the declaration is not 2003 // changed by attaching the prior declaration, because both are externally 2004 // declarable (and thus ExternalLinkage or VisibleNoLinkage). 2005 // 2006 // FIXME: This is subtle and fragile. 2007 return New->isExternallyDeclarable(); 2008 } 2009 2010 /// Retrieve the visible declaration corresponding to D, if any. 2011 /// 2012 /// This routine determines whether the declaration D is visible in the current 2013 /// module, with the current imports. If not, it checks whether any 2014 /// redeclaration of D is visible, and if so, returns that declaration. 2015 /// 2016 /// \returns D, or a visible previous declaration of D, whichever is more recent 2017 /// and visible. If no declaration of D is visible, returns null. 2018 static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D, 2019 unsigned IDNS) { 2020 assert(!LookupResult::isAvailableForLookup(SemaRef, D) && "not in slow case"); 2021 2022 for (auto *RD : D->redecls()) { 2023 // Don't bother with extra checks if we already know this one isn't visible. 2024 if (RD == D) 2025 continue; 2026 2027 auto ND = cast<NamedDecl>(RD); 2028 // FIXME: This is wrong in the case where the previous declaration is not 2029 // visible in the same scope as D. This needs to be done much more 2030 // carefully. 2031 if (ND->isInIdentifierNamespace(IDNS) && 2032 LookupResult::isAvailableForLookup(SemaRef, ND)) 2033 return ND; 2034 } 2035 2036 return nullptr; 2037 } 2038 2039 bool Sema::hasVisibleDeclarationSlow(const NamedDecl *D, 2040 llvm::SmallVectorImpl<Module *> *Modules) { 2041 assert(!isVisible(D) && "not in slow case"); 2042 return hasAcceptableDeclarationImpl( 2043 *this, D, Modules, [](const NamedDecl *) { return true; }, 2044 Sema::AcceptableKind::Visible); 2045 } 2046 2047 bool Sema::hasReachableDeclarationSlow( 2048 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 2049 assert(!isReachable(D) && "not in slow case"); 2050 return hasAcceptableDeclarationImpl( 2051 *this, D, Modules, [](const NamedDecl *) { return true; }, 2052 Sema::AcceptableKind::Reachable); 2053 } 2054 2055 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const { 2056 if (auto *ND = dyn_cast<NamespaceDecl>(D)) { 2057 // Namespaces are a bit of a special case: we expect there to be a lot of 2058 // redeclarations of some namespaces, all declarations of a namespace are 2059 // essentially interchangeable, all declarations are found by name lookup 2060 // if any is, and namespaces are never looked up during template 2061 // instantiation. So we benefit from caching the check in this case, and 2062 // it is correct to do so. 2063 auto *Key = ND->getCanonicalDecl(); 2064 if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Key)) 2065 return Acceptable; 2066 auto *Acceptable = isVisible(getSema(), Key) 2067 ? Key 2068 : findAcceptableDecl(getSema(), Key, IDNS); 2069 if (Acceptable) 2070 getSema().VisibleNamespaceCache.insert(std::make_pair(Key, Acceptable)); 2071 return Acceptable; 2072 } 2073 2074 return findAcceptableDecl(getSema(), D, IDNS); 2075 } 2076 2077 bool LookupResult::isVisible(Sema &SemaRef, NamedDecl *D) { 2078 // If this declaration is already visible, return it directly. 2079 if (D->isUnconditionallyVisible()) 2080 return true; 2081 2082 // During template instantiation, we can refer to hidden declarations, if 2083 // they were visible in any module along the path of instantiation. 2084 return isAcceptableSlow(SemaRef, D, Sema::AcceptableKind::Visible); 2085 } 2086 2087 bool LookupResult::isReachable(Sema &SemaRef, NamedDecl *D) { 2088 if (D->isUnconditionallyVisible()) 2089 return true; 2090 2091 return isAcceptableSlow(SemaRef, D, Sema::AcceptableKind::Reachable); 2092 } 2093 2094 bool LookupResult::isAvailableForLookup(Sema &SemaRef, NamedDecl *ND) { 2095 // We should check the visibility at the callsite already. 2096 if (isVisible(SemaRef, ND)) 2097 return true; 2098 2099 // Deduction guide lives in namespace scope generally, but it is just a 2100 // hint to the compilers. What we actually lookup for is the generated member 2101 // of the corresponding template. So it is sufficient to check the 2102 // reachability of the template decl. 2103 if (auto *DeductionGuide = ND->getDeclName().getCXXDeductionGuideTemplate()) 2104 return SemaRef.hasReachableDefinition(DeductionGuide); 2105 2106 // FIXME: The lookup for allocation function is a standalone process. 2107 // (We can find the logics in Sema::FindAllocationFunctions) 2108 // 2109 // Such structure makes it a problem when we instantiate a template 2110 // declaration using placement allocation function if the placement 2111 // allocation function is invisible. 2112 // (See https://github.com/llvm/llvm-project/issues/59601) 2113 // 2114 // Here we workaround it by making the placement allocation functions 2115 // always acceptable. The downside is that we can't diagnose the direct 2116 // use of the invisible placement allocation functions. (Although such uses 2117 // should be rare). 2118 if (auto *FD = dyn_cast<FunctionDecl>(ND); 2119 FD && FD->isReservedGlobalPlacementOperator()) 2120 return true; 2121 2122 auto *DC = ND->getDeclContext(); 2123 // If ND is not visible and it is at namespace scope, it shouldn't be found 2124 // by name lookup. 2125 if (DC->isFileContext()) 2126 return false; 2127 2128 // [module.interface]p7 2129 // Class and enumeration member names can be found by name lookup in any 2130 // context in which a definition of the type is reachable. 2131 // 2132 // FIXME: The current implementation didn't consider about scope. For example, 2133 // ``` 2134 // // m.cppm 2135 // export module m; 2136 // enum E1 { e1 }; 2137 // // Use.cpp 2138 // import m; 2139 // void test() { 2140 // auto a = E1::e1; // Error as expected. 2141 // auto b = e1; // Should be error. namespace-scope name e1 is not visible 2142 // } 2143 // ``` 2144 // For the above example, the current implementation would emit error for `a` 2145 // correctly. However, the implementation wouldn't diagnose about `b` now. 2146 // Since we only check the reachability for the parent only. 2147 // See clang/test/CXX/module/module.interface/p7.cpp for example. 2148 if (auto *TD = dyn_cast<TagDecl>(DC)) 2149 return SemaRef.hasReachableDefinition(TD); 2150 2151 return false; 2152 } 2153 2154 /// Perform unqualified name lookup starting from a given 2155 /// scope. 2156 /// 2157 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is 2158 /// used to find names within the current scope. For example, 'x' in 2159 /// @code 2160 /// int x; 2161 /// int f() { 2162 /// return x; // unqualified name look finds 'x' in the global scope 2163 /// } 2164 /// @endcode 2165 /// 2166 /// Different lookup criteria can find different names. For example, a 2167 /// particular scope can have both a struct and a function of the same 2168 /// name, and each can be found by certain lookup criteria. For more 2169 /// information about lookup criteria, see the documentation for the 2170 /// class LookupCriteria. 2171 /// 2172 /// @param S The scope from which unqualified name lookup will 2173 /// begin. If the lookup criteria permits, name lookup may also search 2174 /// in the parent scopes. 2175 /// 2176 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to 2177 /// look up and the lookup kind), and is updated with the results of lookup 2178 /// including zero or more declarations and possibly additional information 2179 /// used to diagnose ambiguities. 2180 /// 2181 /// @returns \c true if lookup succeeded and false otherwise. 2182 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation, 2183 bool ForceNoCPlusPlus) { 2184 DeclarationName Name = R.getLookupName(); 2185 if (!Name) return false; 2186 2187 LookupNameKind NameKind = R.getLookupKind(); 2188 2189 if (!getLangOpts().CPlusPlus || ForceNoCPlusPlus) { 2190 // Unqualified name lookup in C/Objective-C is purely lexical, so 2191 // search in the declarations attached to the name. 2192 if (NameKind == Sema::LookupRedeclarationWithLinkage) { 2193 // Find the nearest non-transparent declaration scope. 2194 while (!(S->getFlags() & Scope::DeclScope) || 2195 (S->getEntity() && S->getEntity()->isTransparentContext())) 2196 S = S->getParent(); 2197 } 2198 2199 // When performing a scope lookup, we want to find local extern decls. 2200 FindLocalExternScope FindLocals(R); 2201 2202 // Scan up the scope chain looking for a decl that matches this 2203 // identifier that is in the appropriate namespace. This search 2204 // should not take long, as shadowing of names is uncommon, and 2205 // deep shadowing is extremely uncommon. 2206 bool LeftStartingScope = false; 2207 2208 for (IdentifierResolver::iterator I = IdResolver.begin(Name), 2209 IEnd = IdResolver.end(); 2210 I != IEnd; ++I) 2211 if (NamedDecl *D = R.getAcceptableDecl(*I)) { 2212 if (NameKind == LookupRedeclarationWithLinkage) { 2213 // Determine whether this (or a previous) declaration is 2214 // out-of-scope. 2215 if (!LeftStartingScope && !S->isDeclScope(*I)) 2216 LeftStartingScope = true; 2217 2218 // If we found something outside of our starting scope that 2219 // does not have linkage, skip it. 2220 if (LeftStartingScope && !((*I)->hasLinkage())) { 2221 R.setShadowed(); 2222 continue; 2223 } 2224 } 2225 else if (NameKind == LookupObjCImplicitSelfParam && 2226 !isa<ImplicitParamDecl>(*I)) 2227 continue; 2228 2229 R.addDecl(D); 2230 2231 // Check whether there are any other declarations with the same name 2232 // and in the same scope. 2233 if (I != IEnd) { 2234 // Find the scope in which this declaration was declared (if it 2235 // actually exists in a Scope). 2236 while (S && !S->isDeclScope(D)) 2237 S = S->getParent(); 2238 2239 // If the scope containing the declaration is the translation unit, 2240 // then we'll need to perform our checks based on the matching 2241 // DeclContexts rather than matching scopes. 2242 if (S && isNamespaceOrTranslationUnitScope(S)) 2243 S = nullptr; 2244 2245 // Compute the DeclContext, if we need it. 2246 DeclContext *DC = nullptr; 2247 if (!S) 2248 DC = (*I)->getDeclContext()->getRedeclContext(); 2249 2250 IdentifierResolver::iterator LastI = I; 2251 for (++LastI; LastI != IEnd; ++LastI) { 2252 if (S) { 2253 // Match based on scope. 2254 if (!S->isDeclScope(*LastI)) 2255 break; 2256 } else { 2257 // Match based on DeclContext. 2258 DeclContext *LastDC 2259 = (*LastI)->getDeclContext()->getRedeclContext(); 2260 if (!LastDC->Equals(DC)) 2261 break; 2262 } 2263 2264 // If the declaration is in the right namespace and visible, add it. 2265 if (NamedDecl *LastD = R.getAcceptableDecl(*LastI)) 2266 R.addDecl(LastD); 2267 } 2268 2269 R.resolveKind(); 2270 } 2271 2272 return true; 2273 } 2274 } else { 2275 // Perform C++ unqualified name lookup. 2276 if (CppLookupName(R, S)) 2277 return true; 2278 } 2279 2280 // If we didn't find a use of this identifier, and if the identifier 2281 // corresponds to a compiler builtin, create the decl object for the builtin 2282 // now, injecting it into translation unit scope, and return it. 2283 if (AllowBuiltinCreation && LookupBuiltin(R)) 2284 return true; 2285 2286 // If we didn't find a use of this identifier, the ExternalSource 2287 // may be able to handle the situation. 2288 // Note: some lookup failures are expected! 2289 // See e.g. R.isForRedeclaration(). 2290 return (ExternalSource && ExternalSource->LookupUnqualified(R, S)); 2291 } 2292 2293 /// Perform qualified name lookup in the namespaces nominated by 2294 /// using directives by the given context. 2295 /// 2296 /// C++98 [namespace.qual]p2: 2297 /// Given X::m (where X is a user-declared namespace), or given \::m 2298 /// (where X is the global namespace), let S be the set of all 2299 /// declarations of m in X and in the transitive closure of all 2300 /// namespaces nominated by using-directives in X and its used 2301 /// namespaces, except that using-directives are ignored in any 2302 /// namespace, including X, directly containing one or more 2303 /// declarations of m. No namespace is searched more than once in 2304 /// the lookup of a name. If S is the empty set, the program is 2305 /// ill-formed. Otherwise, if S has exactly one member, or if the 2306 /// context of the reference is a using-declaration 2307 /// (namespace.udecl), S is the required set of declarations of 2308 /// m. Otherwise if the use of m is not one that allows a unique 2309 /// declaration to be chosen from S, the program is ill-formed. 2310 /// 2311 /// C++98 [namespace.qual]p5: 2312 /// During the lookup of a qualified namespace member name, if the 2313 /// lookup finds more than one declaration of the member, and if one 2314 /// declaration introduces a class name or enumeration name and the 2315 /// other declarations either introduce the same object, the same 2316 /// enumerator or a set of functions, the non-type name hides the 2317 /// class or enumeration name if and only if the declarations are 2318 /// from the same namespace; otherwise (the declarations are from 2319 /// different namespaces), the program is ill-formed. 2320 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R, 2321 DeclContext *StartDC) { 2322 assert(StartDC->isFileContext() && "start context is not a file context"); 2323 2324 // We have not yet looked into these namespaces, much less added 2325 // their "using-children" to the queue. 2326 SmallVector<NamespaceDecl*, 8> Queue; 2327 2328 // We have at least added all these contexts to the queue. 2329 llvm::SmallPtrSet<DeclContext*, 8> Visited; 2330 Visited.insert(StartDC); 2331 2332 // We have already looked into the initial namespace; seed the queue 2333 // with its using-children. 2334 for (auto *I : StartDC->using_directives()) { 2335 NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace(); 2336 if (S.isVisible(I) && Visited.insert(ND).second) 2337 Queue.push_back(ND); 2338 } 2339 2340 // The easiest way to implement the restriction in [namespace.qual]p5 2341 // is to check whether any of the individual results found a tag 2342 // and, if so, to declare an ambiguity if the final result is not 2343 // a tag. 2344 bool FoundTag = false; 2345 bool FoundNonTag = false; 2346 2347 LookupResult LocalR(LookupResult::Temporary, R); 2348 2349 bool Found = false; 2350 while (!Queue.empty()) { 2351 NamespaceDecl *ND = Queue.pop_back_val(); 2352 2353 // We go through some convolutions here to avoid copying results 2354 // between LookupResults. 2355 bool UseLocal = !R.empty(); 2356 LookupResult &DirectR = UseLocal ? LocalR : R; 2357 bool FoundDirect = LookupDirect(S, DirectR, ND); 2358 2359 if (FoundDirect) { 2360 // First do any local hiding. 2361 DirectR.resolveKind(); 2362 2363 // If the local result is a tag, remember that. 2364 if (DirectR.isSingleTagDecl()) 2365 FoundTag = true; 2366 else 2367 FoundNonTag = true; 2368 2369 // Append the local results to the total results if necessary. 2370 if (UseLocal) { 2371 R.addAllDecls(LocalR); 2372 LocalR.clear(); 2373 } 2374 } 2375 2376 // If we find names in this namespace, ignore its using directives. 2377 if (FoundDirect) { 2378 Found = true; 2379 continue; 2380 } 2381 2382 for (auto *I : ND->using_directives()) { 2383 NamespaceDecl *Nom = I->getNominatedNamespace(); 2384 if (S.isVisible(I) && Visited.insert(Nom).second) 2385 Queue.push_back(Nom); 2386 } 2387 } 2388 2389 if (Found) { 2390 if (FoundTag && FoundNonTag) 2391 R.setAmbiguousQualifiedTagHiding(); 2392 else 2393 R.resolveKind(); 2394 } 2395 2396 return Found; 2397 } 2398 2399 /// Perform qualified name lookup into a given context. 2400 /// 2401 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find 2402 /// names when the context of those names is explicit specified, e.g., 2403 /// "std::vector" or "x->member", or as part of unqualified name lookup. 2404 /// 2405 /// Different lookup criteria can find different names. For example, a 2406 /// particular scope can have both a struct and a function of the same 2407 /// name, and each can be found by certain lookup criteria. For more 2408 /// information about lookup criteria, see the documentation for the 2409 /// class LookupCriteria. 2410 /// 2411 /// \param R captures both the lookup criteria and any lookup results found. 2412 /// 2413 /// \param LookupCtx The context in which qualified name lookup will 2414 /// search. If the lookup criteria permits, name lookup may also search 2415 /// in the parent contexts or (for C++ classes) base classes. 2416 /// 2417 /// \param InUnqualifiedLookup true if this is qualified name lookup that 2418 /// occurs as part of unqualified name lookup. 2419 /// 2420 /// \returns true if lookup succeeded, false if it failed. 2421 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 2422 bool InUnqualifiedLookup) { 2423 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context"); 2424 2425 if (!R.getLookupName()) 2426 return false; 2427 2428 // Make sure that the declaration context is complete. 2429 assert((!isa<TagDecl>(LookupCtx) || 2430 LookupCtx->isDependentContext() || 2431 cast<TagDecl>(LookupCtx)->isCompleteDefinition() || 2432 cast<TagDecl>(LookupCtx)->isBeingDefined()) && 2433 "Declaration context must already be complete!"); 2434 2435 struct QualifiedLookupInScope { 2436 bool oldVal; 2437 DeclContext *Context; 2438 // Set flag in DeclContext informing debugger that we're looking for qualified name 2439 QualifiedLookupInScope(DeclContext *ctx) 2440 : oldVal(ctx->shouldUseQualifiedLookup()), Context(ctx) { 2441 ctx->setUseQualifiedLookup(); 2442 } 2443 ~QualifiedLookupInScope() { 2444 Context->setUseQualifiedLookup(oldVal); 2445 } 2446 } QL(LookupCtx); 2447 2448 if (LookupDirect(*this, R, LookupCtx)) { 2449 R.resolveKind(); 2450 if (isa<CXXRecordDecl>(LookupCtx)) 2451 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx)); 2452 return true; 2453 } 2454 2455 // Don't descend into implied contexts for redeclarations. 2456 // C++98 [namespace.qual]p6: 2457 // In a declaration for a namespace member in which the 2458 // declarator-id is a qualified-id, given that the qualified-id 2459 // for the namespace member has the form 2460 // nested-name-specifier unqualified-id 2461 // the unqualified-id shall name a member of the namespace 2462 // designated by the nested-name-specifier. 2463 // See also [class.mfct]p5 and [class.static.data]p2. 2464 if (R.isForRedeclaration()) 2465 return false; 2466 2467 // If this is a namespace, look it up in the implied namespaces. 2468 if (LookupCtx->isFileContext()) 2469 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx); 2470 2471 // If this isn't a C++ class, we aren't allowed to look into base 2472 // classes, we're done. 2473 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx); 2474 if (!LookupRec || !LookupRec->getDefinition()) 2475 return false; 2476 2477 // We're done for lookups that can never succeed for C++ classes. 2478 if (R.getLookupKind() == LookupOperatorName || 2479 R.getLookupKind() == LookupNamespaceName || 2480 R.getLookupKind() == LookupObjCProtocolName || 2481 R.getLookupKind() == LookupLabel) 2482 return false; 2483 2484 // If we're performing qualified name lookup into a dependent class, 2485 // then we are actually looking into a current instantiation. If we have any 2486 // dependent base classes, then we either have to delay lookup until 2487 // template instantiation time (at which point all bases will be available) 2488 // or we have to fail. 2489 if (!InUnqualifiedLookup && LookupRec->isDependentContext() && 2490 LookupRec->hasAnyDependentBases()) { 2491 R.setNotFoundInCurrentInstantiation(); 2492 return false; 2493 } 2494 2495 // Perform lookup into our base classes. 2496 2497 DeclarationName Name = R.getLookupName(); 2498 unsigned IDNS = R.getIdentifierNamespace(); 2499 2500 // Look for this member in our base classes. 2501 auto BaseCallback = [Name, IDNS](const CXXBaseSpecifier *Specifier, 2502 CXXBasePath &Path) -> bool { 2503 CXXRecordDecl *BaseRecord = Specifier->getType()->getAsCXXRecordDecl(); 2504 // Drop leading non-matching lookup results from the declaration list so 2505 // we don't need to consider them again below. 2506 for (Path.Decls = BaseRecord->lookup(Name).begin(); 2507 Path.Decls != Path.Decls.end(); ++Path.Decls) { 2508 if ((*Path.Decls)->isInIdentifierNamespace(IDNS)) 2509 return true; 2510 } 2511 return false; 2512 }; 2513 2514 CXXBasePaths Paths; 2515 Paths.setOrigin(LookupRec); 2516 if (!LookupRec->lookupInBases(BaseCallback, Paths)) 2517 return false; 2518 2519 R.setNamingClass(LookupRec); 2520 2521 // C++ [class.member.lookup]p2: 2522 // [...] If the resulting set of declarations are not all from 2523 // sub-objects of the same type, or the set has a nonstatic member 2524 // and includes members from distinct sub-objects, there is an 2525 // ambiguity and the program is ill-formed. Otherwise that set is 2526 // the result of the lookup. 2527 QualType SubobjectType; 2528 int SubobjectNumber = 0; 2529 AccessSpecifier SubobjectAccess = AS_none; 2530 2531 // Check whether the given lookup result contains only static members. 2532 auto HasOnlyStaticMembers = [&](DeclContext::lookup_iterator Result) { 2533 for (DeclContext::lookup_iterator I = Result, E = I.end(); I != E; ++I) 2534 if ((*I)->isInIdentifierNamespace(IDNS) && (*I)->isCXXInstanceMember()) 2535 return false; 2536 return true; 2537 }; 2538 2539 bool TemplateNameLookup = R.isTemplateNameLookup(); 2540 2541 // Determine whether two sets of members contain the same members, as 2542 // required by C++ [class.member.lookup]p6. 2543 auto HasSameDeclarations = [&](DeclContext::lookup_iterator A, 2544 DeclContext::lookup_iterator B) { 2545 using Iterator = DeclContextLookupResult::iterator; 2546 using Result = const void *; 2547 2548 auto Next = [&](Iterator &It, Iterator End) -> Result { 2549 while (It != End) { 2550 NamedDecl *ND = *It++; 2551 if (!ND->isInIdentifierNamespace(IDNS)) 2552 continue; 2553 2554 // C++ [temp.local]p3: 2555 // A lookup that finds an injected-class-name (10.2) can result in 2556 // an ambiguity in certain cases (for example, if it is found in 2557 // more than one base class). If all of the injected-class-names 2558 // that are found refer to specializations of the same class 2559 // template, and if the name is used as a template-name, the 2560 // reference refers to the class template itself and not a 2561 // specialization thereof, and is not ambiguous. 2562 if (TemplateNameLookup) 2563 if (auto *TD = getAsTemplateNameDecl(ND)) 2564 ND = TD; 2565 2566 // C++ [class.member.lookup]p3: 2567 // type declarations (including injected-class-names) are replaced by 2568 // the types they designate 2569 if (const TypeDecl *TD = dyn_cast<TypeDecl>(ND->getUnderlyingDecl())) { 2570 QualType T = Context.getTypeDeclType(TD); 2571 return T.getCanonicalType().getAsOpaquePtr(); 2572 } 2573 2574 return ND->getUnderlyingDecl()->getCanonicalDecl(); 2575 } 2576 return nullptr; 2577 }; 2578 2579 // We'll often find the declarations are in the same order. Handle this 2580 // case (and the special case of only one declaration) efficiently. 2581 Iterator AIt = A, BIt = B, AEnd, BEnd; 2582 while (true) { 2583 Result AResult = Next(AIt, AEnd); 2584 Result BResult = Next(BIt, BEnd); 2585 if (!AResult && !BResult) 2586 return true; 2587 if (!AResult || !BResult) 2588 return false; 2589 if (AResult != BResult) { 2590 // Found a mismatch; carefully check both lists, accounting for the 2591 // possibility of declarations appearing more than once. 2592 llvm::SmallDenseMap<Result, bool, 32> AResults; 2593 for (; AResult; AResult = Next(AIt, AEnd)) 2594 AResults.insert({AResult, /*FoundInB*/false}); 2595 unsigned Found = 0; 2596 for (; BResult; BResult = Next(BIt, BEnd)) { 2597 auto It = AResults.find(BResult); 2598 if (It == AResults.end()) 2599 return false; 2600 if (!It->second) { 2601 It->second = true; 2602 ++Found; 2603 } 2604 } 2605 return AResults.size() == Found; 2606 } 2607 } 2608 }; 2609 2610 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); 2611 Path != PathEnd; ++Path) { 2612 const CXXBasePathElement &PathElement = Path->back(); 2613 2614 // Pick the best (i.e. most permissive i.e. numerically lowest) access 2615 // across all paths. 2616 SubobjectAccess = std::min(SubobjectAccess, Path->Access); 2617 2618 // Determine whether we're looking at a distinct sub-object or not. 2619 if (SubobjectType.isNull()) { 2620 // This is the first subobject we've looked at. Record its type. 2621 SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); 2622 SubobjectNumber = PathElement.SubobjectNumber; 2623 continue; 2624 } 2625 2626 if (SubobjectType != 2627 Context.getCanonicalType(PathElement.Base->getType())) { 2628 // We found members of the given name in two subobjects of 2629 // different types. If the declaration sets aren't the same, this 2630 // lookup is ambiguous. 2631 // 2632 // FIXME: The language rule says that this applies irrespective of 2633 // whether the sets contain only static members. 2634 if (HasOnlyStaticMembers(Path->Decls) && 2635 HasSameDeclarations(Paths.begin()->Decls, Path->Decls)) 2636 continue; 2637 2638 R.setAmbiguousBaseSubobjectTypes(Paths); 2639 return true; 2640 } 2641 2642 // FIXME: This language rule no longer exists. Checking for ambiguous base 2643 // subobjects should be done as part of formation of a class member access 2644 // expression (when converting the object parameter to the member's type). 2645 if (SubobjectNumber != PathElement.SubobjectNumber) { 2646 // We have a different subobject of the same type. 2647 2648 // C++ [class.member.lookup]p5: 2649 // A static member, a nested type or an enumerator defined in 2650 // a base class T can unambiguously be found even if an object 2651 // has more than one base class subobject of type T. 2652 if (HasOnlyStaticMembers(Path->Decls)) 2653 continue; 2654 2655 // We have found a nonstatic member name in multiple, distinct 2656 // subobjects. Name lookup is ambiguous. 2657 R.setAmbiguousBaseSubobjects(Paths); 2658 return true; 2659 } 2660 } 2661 2662 // Lookup in a base class succeeded; return these results. 2663 2664 for (DeclContext::lookup_iterator I = Paths.front().Decls, E = I.end(); 2665 I != E; ++I) { 2666 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess, 2667 (*I)->getAccess()); 2668 if (NamedDecl *ND = R.getAcceptableDecl(*I)) 2669 R.addDecl(ND, AS); 2670 } 2671 R.resolveKind(); 2672 return true; 2673 } 2674 2675 /// Performs qualified name lookup or special type of lookup for 2676 /// "__super::" scope specifier. 2677 /// 2678 /// This routine is a convenience overload meant to be called from contexts 2679 /// that need to perform a qualified name lookup with an optional C++ scope 2680 /// specifier that might require special kind of lookup. 2681 /// 2682 /// \param R captures both the lookup criteria and any lookup results found. 2683 /// 2684 /// \param LookupCtx The context in which qualified name lookup will 2685 /// search. 2686 /// 2687 /// \param SS An optional C++ scope-specifier. 2688 /// 2689 /// \returns true if lookup succeeded, false if it failed. 2690 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 2691 CXXScopeSpec &SS) { 2692 auto *NNS = SS.getScopeRep(); 2693 if (NNS && NNS->getKind() == NestedNameSpecifier::Super) 2694 return LookupInSuper(R, NNS->getAsRecordDecl()); 2695 else 2696 2697 return LookupQualifiedName(R, LookupCtx); 2698 } 2699 2700 /// Performs name lookup for a name that was parsed in the 2701 /// source code, and may contain a C++ scope specifier. 2702 /// 2703 /// This routine is a convenience routine meant to be called from 2704 /// contexts that receive a name and an optional C++ scope specifier 2705 /// (e.g., "N::M::x"). It will then perform either qualified or 2706 /// unqualified name lookup (with LookupQualifiedName or LookupName, 2707 /// respectively) on the given name and return those results. It will 2708 /// perform a special type of lookup for "__super::" scope specifier. 2709 /// 2710 /// @param S The scope from which unqualified name lookup will 2711 /// begin. 2712 /// 2713 /// @param SS An optional C++ scope-specifier, e.g., "::N::M". 2714 /// 2715 /// @param EnteringContext Indicates whether we are going to enter the 2716 /// context of the scope-specifier SS (if present). 2717 /// 2718 /// @returns True if any decls were found (but possibly ambiguous) 2719 bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS, 2720 bool AllowBuiltinCreation, bool EnteringContext) { 2721 if (SS && SS->isInvalid()) { 2722 // When the scope specifier is invalid, don't even look for 2723 // anything. 2724 return false; 2725 } 2726 2727 if (SS && SS->isSet()) { 2728 NestedNameSpecifier *NNS = SS->getScopeRep(); 2729 if (NNS->getKind() == NestedNameSpecifier::Super) 2730 return LookupInSuper(R, NNS->getAsRecordDecl()); 2731 2732 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { 2733 // We have resolved the scope specifier to a particular declaration 2734 // contex, and will perform name lookup in that context. 2735 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC)) 2736 return false; 2737 2738 R.setContextRange(SS->getRange()); 2739 return LookupQualifiedName(R, DC); 2740 } 2741 2742 // We could not resolve the scope specified to a specific declaration 2743 // context, which means that SS refers to an unknown specialization. 2744 // Name lookup can't find anything in this case. 2745 R.setNotFoundInCurrentInstantiation(); 2746 R.setContextRange(SS->getRange()); 2747 return false; 2748 } 2749 2750 // Perform unqualified name lookup starting in the given scope. 2751 return LookupName(R, S, AllowBuiltinCreation); 2752 } 2753 2754 /// Perform qualified name lookup into all base classes of the given 2755 /// class. 2756 /// 2757 /// \param R captures both the lookup criteria and any lookup results found. 2758 /// 2759 /// \param Class The context in which qualified name lookup will 2760 /// search. Name lookup will search in all base classes merging the results. 2761 /// 2762 /// @returns True if any decls were found (but possibly ambiguous) 2763 bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) { 2764 // The access-control rules we use here are essentially the rules for 2765 // doing a lookup in Class that just magically skipped the direct 2766 // members of Class itself. That is, the naming class is Class, and the 2767 // access includes the access of the base. 2768 for (const auto &BaseSpec : Class->bases()) { 2769 CXXRecordDecl *RD = cast<CXXRecordDecl>( 2770 BaseSpec.getType()->castAs<RecordType>()->getDecl()); 2771 LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind()); 2772 Result.setBaseObjectType(Context.getRecordType(Class)); 2773 LookupQualifiedName(Result, RD); 2774 2775 // Copy the lookup results into the target, merging the base's access into 2776 // the path access. 2777 for (auto I = Result.begin(), E = Result.end(); I != E; ++I) { 2778 R.addDecl(I.getDecl(), 2779 CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(), 2780 I.getAccess())); 2781 } 2782 2783 Result.suppressDiagnostics(); 2784 } 2785 2786 R.resolveKind(); 2787 R.setNamingClass(Class); 2788 2789 return !R.empty(); 2790 } 2791 2792 /// Produce a diagnostic describing the ambiguity that resulted 2793 /// from name lookup. 2794 /// 2795 /// \param Result The result of the ambiguous lookup to be diagnosed. 2796 void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) { 2797 assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); 2798 2799 DeclarationName Name = Result.getLookupName(); 2800 SourceLocation NameLoc = Result.getNameLoc(); 2801 SourceRange LookupRange = Result.getContextRange(); 2802 2803 switch (Result.getAmbiguityKind()) { 2804 case LookupResult::AmbiguousBaseSubobjects: { 2805 CXXBasePaths *Paths = Result.getBasePaths(); 2806 QualType SubobjectType = Paths->front().back().Base->getType(); 2807 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) 2808 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) 2809 << LookupRange; 2810 2811 DeclContext::lookup_iterator Found = Paths->front().Decls; 2812 while (isa<CXXMethodDecl>(*Found) && 2813 cast<CXXMethodDecl>(*Found)->isStatic()) 2814 ++Found; 2815 2816 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); 2817 break; 2818 } 2819 2820 case LookupResult::AmbiguousBaseSubobjectTypes: { 2821 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) 2822 << Name << LookupRange; 2823 2824 CXXBasePaths *Paths = Result.getBasePaths(); 2825 std::set<const NamedDecl *> DeclsPrinted; 2826 for (CXXBasePaths::paths_iterator Path = Paths->begin(), 2827 PathEnd = Paths->end(); 2828 Path != PathEnd; ++Path) { 2829 const NamedDecl *D = *Path->Decls; 2830 if (!D->isInIdentifierNamespace(Result.getIdentifierNamespace())) 2831 continue; 2832 if (DeclsPrinted.insert(D).second) { 2833 if (const auto *TD = dyn_cast<TypedefNameDecl>(D->getUnderlyingDecl())) 2834 Diag(D->getLocation(), diag::note_ambiguous_member_type_found) 2835 << TD->getUnderlyingType(); 2836 else if (const auto *TD = dyn_cast<TypeDecl>(D->getUnderlyingDecl())) 2837 Diag(D->getLocation(), diag::note_ambiguous_member_type_found) 2838 << Context.getTypeDeclType(TD); 2839 else 2840 Diag(D->getLocation(), diag::note_ambiguous_member_found); 2841 } 2842 } 2843 break; 2844 } 2845 2846 case LookupResult::AmbiguousTagHiding: { 2847 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange; 2848 2849 llvm::SmallPtrSet<NamedDecl*, 8> TagDecls; 2850 2851 for (auto *D : Result) 2852 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 2853 TagDecls.insert(TD); 2854 Diag(TD->getLocation(), diag::note_hidden_tag); 2855 } 2856 2857 for (auto *D : Result) 2858 if (!isa<TagDecl>(D)) 2859 Diag(D->getLocation(), diag::note_hiding_object); 2860 2861 // For recovery purposes, go ahead and implement the hiding. 2862 LookupResult::Filter F = Result.makeFilter(); 2863 while (F.hasNext()) { 2864 if (TagDecls.count(F.next())) 2865 F.erase(); 2866 } 2867 F.done(); 2868 break; 2869 } 2870 2871 case LookupResult::AmbiguousReferenceToPlaceholderVariable: { 2872 Diag(NameLoc, diag::err_using_placeholder_variable) << Name << LookupRange; 2873 DeclContext *DC = nullptr; 2874 for (auto *D : Result) { 2875 Diag(D->getLocation(), diag::note_reference_placeholder) << D; 2876 if (DC != nullptr && DC != D->getDeclContext()) 2877 break; 2878 DC = D->getDeclContext(); 2879 } 2880 break; 2881 } 2882 2883 case LookupResult::AmbiguousReference: { 2884 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; 2885 2886 for (auto *D : Result) 2887 Diag(D->getLocation(), diag::note_ambiguous_candidate) << D; 2888 break; 2889 } 2890 } 2891 } 2892 2893 namespace { 2894 struct AssociatedLookup { 2895 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc, 2896 Sema::AssociatedNamespaceSet &Namespaces, 2897 Sema::AssociatedClassSet &Classes) 2898 : S(S), Namespaces(Namespaces), Classes(Classes), 2899 InstantiationLoc(InstantiationLoc) { 2900 } 2901 2902 bool addClassTransitive(CXXRecordDecl *RD) { 2903 Classes.insert(RD); 2904 return ClassesTransitive.insert(RD); 2905 } 2906 2907 Sema &S; 2908 Sema::AssociatedNamespaceSet &Namespaces; 2909 Sema::AssociatedClassSet &Classes; 2910 SourceLocation InstantiationLoc; 2911 2912 private: 2913 Sema::AssociatedClassSet ClassesTransitive; 2914 }; 2915 } // end anonymous namespace 2916 2917 static void 2918 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T); 2919 2920 // Given the declaration context \param Ctx of a class, class template or 2921 // enumeration, add the associated namespaces to \param Namespaces as described 2922 // in [basic.lookup.argdep]p2. 2923 static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces, 2924 DeclContext *Ctx) { 2925 // The exact wording has been changed in C++14 as a result of 2926 // CWG 1691 (see also CWG 1690 and CWG 1692). We apply it unconditionally 2927 // to all language versions since it is possible to return a local type 2928 // from a lambda in C++11. 2929 // 2930 // C++14 [basic.lookup.argdep]p2: 2931 // If T is a class type [...]. Its associated namespaces are the innermost 2932 // enclosing namespaces of its associated classes. [...] 2933 // 2934 // If T is an enumeration type, its associated namespace is the innermost 2935 // enclosing namespace of its declaration. [...] 2936 2937 // We additionally skip inline namespaces. The innermost non-inline namespace 2938 // contains all names of all its nested inline namespaces anyway, so we can 2939 // replace the entire inline namespace tree with its root. 2940 while (!Ctx->isFileContext() || Ctx->isInlineNamespace()) 2941 Ctx = Ctx->getParent(); 2942 2943 Namespaces.insert(Ctx->getPrimaryContext()); 2944 } 2945 2946 // Add the associated classes and namespaces for argument-dependent 2947 // lookup that involves a template argument (C++ [basic.lookup.argdep]p2). 2948 static void 2949 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 2950 const TemplateArgument &Arg) { 2951 // C++ [basic.lookup.argdep]p2, last bullet: 2952 // -- [...] ; 2953 switch (Arg.getKind()) { 2954 case TemplateArgument::Null: 2955 break; 2956 2957 case TemplateArgument::Type: 2958 // [...] the namespaces and classes associated with the types of the 2959 // template arguments provided for template type parameters (excluding 2960 // template template parameters) 2961 addAssociatedClassesAndNamespaces(Result, Arg.getAsType()); 2962 break; 2963 2964 case TemplateArgument::Template: 2965 case TemplateArgument::TemplateExpansion: { 2966 // [...] the namespaces in which any template template arguments are 2967 // defined; and the classes in which any member templates used as 2968 // template template arguments are defined. 2969 TemplateName Template = Arg.getAsTemplateOrTemplatePattern(); 2970 if (ClassTemplateDecl *ClassTemplate 2971 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) { 2972 DeclContext *Ctx = ClassTemplate->getDeclContext(); 2973 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2974 Result.Classes.insert(EnclosingClass); 2975 // Add the associated namespace for this class. 2976 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2977 } 2978 break; 2979 } 2980 2981 case TemplateArgument::Declaration: 2982 case TemplateArgument::Integral: 2983 case TemplateArgument::Expression: 2984 case TemplateArgument::NullPtr: 2985 case TemplateArgument::StructuralValue: 2986 // [Note: non-type template arguments do not contribute to the set of 2987 // associated namespaces. ] 2988 break; 2989 2990 case TemplateArgument::Pack: 2991 for (const auto &P : Arg.pack_elements()) 2992 addAssociatedClassesAndNamespaces(Result, P); 2993 break; 2994 } 2995 } 2996 2997 // Add the associated classes and namespaces for argument-dependent lookup 2998 // with an argument of class type (C++ [basic.lookup.argdep]p2). 2999 static void 3000 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 3001 CXXRecordDecl *Class) { 3002 3003 // Just silently ignore anything whose name is __va_list_tag. 3004 if (Class->getDeclName() == Result.S.VAListTagName) 3005 return; 3006 3007 // C++ [basic.lookup.argdep]p2: 3008 // [...] 3009 // -- If T is a class type (including unions), its associated 3010 // classes are: the class itself; the class of which it is a 3011 // member, if any; and its direct and indirect base classes. 3012 // Its associated namespaces are the innermost enclosing 3013 // namespaces of its associated classes. 3014 3015 // Add the class of which it is a member, if any. 3016 DeclContext *Ctx = Class->getDeclContext(); 3017 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 3018 Result.Classes.insert(EnclosingClass); 3019 3020 // Add the associated namespace for this class. 3021 CollectEnclosingNamespace(Result.Namespaces, Ctx); 3022 3023 // -- If T is a template-id, its associated namespaces and classes are 3024 // the namespace in which the template is defined; for member 3025 // templates, the member template's class; the namespaces and classes 3026 // associated with the types of the template arguments provided for 3027 // template type parameters (excluding template template parameters); the 3028 // namespaces in which any template template arguments are defined; and 3029 // the classes in which any member templates used as template template 3030 // arguments are defined. [Note: non-type template arguments do not 3031 // contribute to the set of associated namespaces. ] 3032 if (ClassTemplateSpecializationDecl *Spec 3033 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) { 3034 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); 3035 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 3036 Result.Classes.insert(EnclosingClass); 3037 // Add the associated namespace for this class. 3038 CollectEnclosingNamespace(Result.Namespaces, Ctx); 3039 3040 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); 3041 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 3042 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]); 3043 } 3044 3045 // Add the class itself. If we've already transitively visited this class, 3046 // we don't need to visit base classes. 3047 if (!Result.addClassTransitive(Class)) 3048 return; 3049 3050 // Only recurse into base classes for complete types. 3051 if (!Result.S.isCompleteType(Result.InstantiationLoc, 3052 Result.S.Context.getRecordType(Class))) 3053 return; 3054 3055 // Add direct and indirect base classes along with their associated 3056 // namespaces. 3057 SmallVector<CXXRecordDecl *, 32> Bases; 3058 Bases.push_back(Class); 3059 while (!Bases.empty()) { 3060 // Pop this class off the stack. 3061 Class = Bases.pop_back_val(); 3062 3063 // Visit the base classes. 3064 for (const auto &Base : Class->bases()) { 3065 const RecordType *BaseType = Base.getType()->getAs<RecordType>(); 3066 // In dependent contexts, we do ADL twice, and the first time around, 3067 // the base type might be a dependent TemplateSpecializationType, or a 3068 // TemplateTypeParmType. If that happens, simply ignore it. 3069 // FIXME: If we want to support export, we probably need to add the 3070 // namespace of the template in a TemplateSpecializationType, or even 3071 // the classes and namespaces of known non-dependent arguments. 3072 if (!BaseType) 3073 continue; 3074 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 3075 if (Result.addClassTransitive(BaseDecl)) { 3076 // Find the associated namespace for this base class. 3077 DeclContext *BaseCtx = BaseDecl->getDeclContext(); 3078 CollectEnclosingNamespace(Result.Namespaces, BaseCtx); 3079 3080 // Make sure we visit the bases of this base class. 3081 if (BaseDecl->bases_begin() != BaseDecl->bases_end()) 3082 Bases.push_back(BaseDecl); 3083 } 3084 } 3085 } 3086 } 3087 3088 // Add the associated classes and namespaces for 3089 // argument-dependent lookup with an argument of type T 3090 // (C++ [basic.lookup.koenig]p2). 3091 static void 3092 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) { 3093 // C++ [basic.lookup.koenig]p2: 3094 // 3095 // For each argument type T in the function call, there is a set 3096 // of zero or more associated namespaces and a set of zero or more 3097 // associated classes to be considered. The sets of namespaces and 3098 // classes is determined entirely by the types of the function 3099 // arguments (and the namespace of any template template 3100 // argument). Typedef names and using-declarations used to specify 3101 // the types do not contribute to this set. The sets of namespaces 3102 // and classes are determined in the following way: 3103 3104 SmallVector<const Type *, 16> Queue; 3105 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr(); 3106 3107 while (true) { 3108 switch (T->getTypeClass()) { 3109 3110 #define TYPE(Class, Base) 3111 #define DEPENDENT_TYPE(Class, Base) case Type::Class: 3112 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 3113 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class: 3114 #define ABSTRACT_TYPE(Class, Base) 3115 #include "clang/AST/TypeNodes.inc" 3116 // T is canonical. We can also ignore dependent types because 3117 // we don't need to do ADL at the definition point, but if we 3118 // wanted to implement template export (or if we find some other 3119 // use for associated classes and namespaces...) this would be 3120 // wrong. 3121 break; 3122 3123 // -- If T is a pointer to U or an array of U, its associated 3124 // namespaces and classes are those associated with U. 3125 case Type::Pointer: 3126 T = cast<PointerType>(T)->getPointeeType().getTypePtr(); 3127 continue; 3128 case Type::ConstantArray: 3129 case Type::IncompleteArray: 3130 case Type::VariableArray: 3131 T = cast<ArrayType>(T)->getElementType().getTypePtr(); 3132 continue; 3133 3134 // -- If T is a fundamental type, its associated sets of 3135 // namespaces and classes are both empty. 3136 case Type::Builtin: 3137 break; 3138 3139 // -- If T is a class type (including unions), its associated 3140 // classes are: the class itself; the class of which it is 3141 // a member, if any; and its direct and indirect base classes. 3142 // Its associated namespaces are the innermost enclosing 3143 // namespaces of its associated classes. 3144 case Type::Record: { 3145 CXXRecordDecl *Class = 3146 cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl()); 3147 addAssociatedClassesAndNamespaces(Result, Class); 3148 break; 3149 } 3150 3151 // -- If T is an enumeration type, its associated namespace 3152 // is the innermost enclosing namespace of its declaration. 3153 // If it is a class member, its associated class is the 3154 // member’s class; else it has no associated class. 3155 case Type::Enum: { 3156 EnumDecl *Enum = cast<EnumType>(T)->getDecl(); 3157 3158 DeclContext *Ctx = Enum->getDeclContext(); 3159 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 3160 Result.Classes.insert(EnclosingClass); 3161 3162 // Add the associated namespace for this enumeration. 3163 CollectEnclosingNamespace(Result.Namespaces, Ctx); 3164 3165 break; 3166 } 3167 3168 // -- If T is a function type, its associated namespaces and 3169 // classes are those associated with the function parameter 3170 // types and those associated with the return type. 3171 case Type::FunctionProto: { 3172 const FunctionProtoType *Proto = cast<FunctionProtoType>(T); 3173 for (const auto &Arg : Proto->param_types()) 3174 Queue.push_back(Arg.getTypePtr()); 3175 // fallthrough 3176 [[fallthrough]]; 3177 } 3178 case Type::FunctionNoProto: { 3179 const FunctionType *FnType = cast<FunctionType>(T); 3180 T = FnType->getReturnType().getTypePtr(); 3181 continue; 3182 } 3183 3184 // -- If T is a pointer to a member function of a class X, its 3185 // associated namespaces and classes are those associated 3186 // with the function parameter types and return type, 3187 // together with those associated with X. 3188 // 3189 // -- If T is a pointer to a data member of class X, its 3190 // associated namespaces and classes are those associated 3191 // with the member type together with those associated with 3192 // X. 3193 case Type::MemberPointer: { 3194 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T); 3195 3196 // Queue up the class type into which this points. 3197 Queue.push_back(MemberPtr->getClass()); 3198 3199 // And directly continue with the pointee type. 3200 T = MemberPtr->getPointeeType().getTypePtr(); 3201 continue; 3202 } 3203 3204 // As an extension, treat this like a normal pointer. 3205 case Type::BlockPointer: 3206 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr(); 3207 continue; 3208 3209 // References aren't covered by the standard, but that's such an 3210 // obvious defect that we cover them anyway. 3211 case Type::LValueReference: 3212 case Type::RValueReference: 3213 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr(); 3214 continue; 3215 3216 // These are fundamental types. 3217 case Type::Vector: 3218 case Type::ExtVector: 3219 case Type::ConstantMatrix: 3220 case Type::Complex: 3221 case Type::BitInt: 3222 break; 3223 3224 // Non-deduced auto types only get here for error cases. 3225 case Type::Auto: 3226 case Type::DeducedTemplateSpecialization: 3227 break; 3228 3229 // If T is an Objective-C object or interface type, or a pointer to an 3230 // object or interface type, the associated namespace is the global 3231 // namespace. 3232 case Type::ObjCObject: 3233 case Type::ObjCInterface: 3234 case Type::ObjCObjectPointer: 3235 Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl()); 3236 break; 3237 3238 // Atomic types are just wrappers; use the associations of the 3239 // contained type. 3240 case Type::Atomic: 3241 T = cast<AtomicType>(T)->getValueType().getTypePtr(); 3242 continue; 3243 case Type::Pipe: 3244 T = cast<PipeType>(T)->getElementType().getTypePtr(); 3245 continue; 3246 } 3247 3248 if (Queue.empty()) 3249 break; 3250 T = Queue.pop_back_val(); 3251 } 3252 } 3253 3254 /// Find the associated classes and namespaces for 3255 /// argument-dependent lookup for a call with the given set of 3256 /// arguments. 3257 /// 3258 /// This routine computes the sets of associated classes and associated 3259 /// namespaces searched by argument-dependent lookup 3260 /// (C++ [basic.lookup.argdep]) for a given set of arguments. 3261 void Sema::FindAssociatedClassesAndNamespaces( 3262 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args, 3263 AssociatedNamespaceSet &AssociatedNamespaces, 3264 AssociatedClassSet &AssociatedClasses) { 3265 AssociatedNamespaces.clear(); 3266 AssociatedClasses.clear(); 3267 3268 AssociatedLookup Result(*this, InstantiationLoc, 3269 AssociatedNamespaces, AssociatedClasses); 3270 3271 // C++ [basic.lookup.koenig]p2: 3272 // For each argument type T in the function call, there is a set 3273 // of zero or more associated namespaces and a set of zero or more 3274 // associated classes to be considered. The sets of namespaces and 3275 // classes is determined entirely by the types of the function 3276 // arguments (and the namespace of any template template 3277 // argument). 3278 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) { 3279 Expr *Arg = Args[ArgIdx]; 3280 3281 if (Arg->getType() != Context.OverloadTy) { 3282 addAssociatedClassesAndNamespaces(Result, Arg->getType()); 3283 continue; 3284 } 3285 3286 // [...] In addition, if the argument is the name or address of a 3287 // set of overloaded functions and/or function templates, its 3288 // associated classes and namespaces are the union of those 3289 // associated with each of the members of the set: the namespace 3290 // in which the function or function template is defined and the 3291 // classes and namespaces associated with its (non-dependent) 3292 // parameter types and return type. 3293 OverloadExpr *OE = OverloadExpr::find(Arg).Expression; 3294 3295 for (const NamedDecl *D : OE->decls()) { 3296 // Look through any using declarations to find the underlying function. 3297 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction(); 3298 3299 // Add the classes and namespaces associated with the parameter 3300 // types and return type of this function. 3301 addAssociatedClassesAndNamespaces(Result, FDecl->getType()); 3302 } 3303 } 3304 } 3305 3306 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name, 3307 SourceLocation Loc, 3308 LookupNameKind NameKind, 3309 RedeclarationKind Redecl) { 3310 LookupResult R(*this, Name, Loc, NameKind, Redecl); 3311 LookupName(R, S); 3312 return R.getAsSingle<NamedDecl>(); 3313 } 3314 3315 /// Find the protocol with the given name, if any. 3316 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II, 3317 SourceLocation IdLoc, 3318 RedeclarationKind Redecl) { 3319 Decl *D = LookupSingleName(TUScope, II, IdLoc, 3320 LookupObjCProtocolName, Redecl); 3321 return cast_or_null<ObjCProtocolDecl>(D); 3322 } 3323 3324 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, 3325 UnresolvedSetImpl &Functions) { 3326 // C++ [over.match.oper]p3: 3327 // -- The set of non-member candidates is the result of the 3328 // unqualified lookup of operator@ in the context of the 3329 // expression according to the usual rules for name lookup in 3330 // unqualified function calls (3.4.2) except that all member 3331 // functions are ignored. 3332 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3333 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName); 3334 LookupName(Operators, S); 3335 3336 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); 3337 Functions.append(Operators.begin(), Operators.end()); 3338 } 3339 3340 Sema::SpecialMemberOverloadResult Sema::LookupSpecialMember(CXXRecordDecl *RD, 3341 CXXSpecialMember SM, 3342 bool ConstArg, 3343 bool VolatileArg, 3344 bool RValueThis, 3345 bool ConstThis, 3346 bool VolatileThis) { 3347 assert(CanDeclareSpecialMemberFunction(RD) && 3348 "doing special member lookup into record that isn't fully complete"); 3349 RD = RD->getDefinition(); 3350 if (RValueThis || ConstThis || VolatileThis) 3351 assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) && 3352 "constructors and destructors always have unqualified lvalue this"); 3353 if (ConstArg || VolatileArg) 3354 assert((SM != CXXDefaultConstructor && SM != CXXDestructor) && 3355 "parameter-less special members can't have qualified arguments"); 3356 3357 // FIXME: Get the caller to pass in a location for the lookup. 3358 SourceLocation LookupLoc = RD->getLocation(); 3359 3360 llvm::FoldingSetNodeID ID; 3361 ID.AddPointer(RD); 3362 ID.AddInteger(SM); 3363 ID.AddInteger(ConstArg); 3364 ID.AddInteger(VolatileArg); 3365 ID.AddInteger(RValueThis); 3366 ID.AddInteger(ConstThis); 3367 ID.AddInteger(VolatileThis); 3368 3369 void *InsertPoint; 3370 SpecialMemberOverloadResultEntry *Result = 3371 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint); 3372 3373 // This was already cached 3374 if (Result) 3375 return *Result; 3376 3377 Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>(); 3378 Result = new (Result) SpecialMemberOverloadResultEntry(ID); 3379 SpecialMemberCache.InsertNode(Result, InsertPoint); 3380 3381 if (SM == CXXDestructor) { 3382 if (RD->needsImplicitDestructor()) { 3383 runWithSufficientStackSpace(RD->getLocation(), [&] { 3384 DeclareImplicitDestructor(RD); 3385 }); 3386 } 3387 CXXDestructorDecl *DD = RD->getDestructor(); 3388 Result->setMethod(DD); 3389 Result->setKind(DD && !DD->isDeleted() 3390 ? SpecialMemberOverloadResult::Success 3391 : SpecialMemberOverloadResult::NoMemberOrDeleted); 3392 return *Result; 3393 } 3394 3395 // Prepare for overload resolution. Here we construct a synthetic argument 3396 // if necessary and make sure that implicit functions are declared. 3397 CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD)); 3398 DeclarationName Name; 3399 Expr *Arg = nullptr; 3400 unsigned NumArgs; 3401 3402 QualType ArgType = CanTy; 3403 ExprValueKind VK = VK_LValue; 3404 3405 if (SM == CXXDefaultConstructor) { 3406 Name = Context.DeclarationNames.getCXXConstructorName(CanTy); 3407 NumArgs = 0; 3408 if (RD->needsImplicitDefaultConstructor()) { 3409 runWithSufficientStackSpace(RD->getLocation(), [&] { 3410 DeclareImplicitDefaultConstructor(RD); 3411 }); 3412 } 3413 } else { 3414 if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) { 3415 Name = Context.DeclarationNames.getCXXConstructorName(CanTy); 3416 if (RD->needsImplicitCopyConstructor()) { 3417 runWithSufficientStackSpace(RD->getLocation(), [&] { 3418 DeclareImplicitCopyConstructor(RD); 3419 }); 3420 } 3421 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor()) { 3422 runWithSufficientStackSpace(RD->getLocation(), [&] { 3423 DeclareImplicitMoveConstructor(RD); 3424 }); 3425 } 3426 } else { 3427 Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal); 3428 if (RD->needsImplicitCopyAssignment()) { 3429 runWithSufficientStackSpace(RD->getLocation(), [&] { 3430 DeclareImplicitCopyAssignment(RD); 3431 }); 3432 } 3433 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment()) { 3434 runWithSufficientStackSpace(RD->getLocation(), [&] { 3435 DeclareImplicitMoveAssignment(RD); 3436 }); 3437 } 3438 } 3439 3440 if (ConstArg) 3441 ArgType.addConst(); 3442 if (VolatileArg) 3443 ArgType.addVolatile(); 3444 3445 // This isn't /really/ specified by the standard, but it's implied 3446 // we should be working from a PRValue in the case of move to ensure 3447 // that we prefer to bind to rvalue references, and an LValue in the 3448 // case of copy to ensure we don't bind to rvalue references. 3449 // Possibly an XValue is actually correct in the case of move, but 3450 // there is no semantic difference for class types in this restricted 3451 // case. 3452 if (SM == CXXCopyConstructor || SM == CXXCopyAssignment) 3453 VK = VK_LValue; 3454 else 3455 VK = VK_PRValue; 3456 } 3457 3458 OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK); 3459 3460 if (SM != CXXDefaultConstructor) { 3461 NumArgs = 1; 3462 Arg = &FakeArg; 3463 } 3464 3465 // Create the object argument 3466 QualType ThisTy = CanTy; 3467 if (ConstThis) 3468 ThisTy.addConst(); 3469 if (VolatileThis) 3470 ThisTy.addVolatile(); 3471 Expr::Classification Classification = 3472 OpaqueValueExpr(LookupLoc, ThisTy, RValueThis ? VK_PRValue : VK_LValue) 3473 .Classify(Context); 3474 3475 // Now we perform lookup on the name we computed earlier and do overload 3476 // resolution. Lookup is only performed directly into the class since there 3477 // will always be a (possibly implicit) declaration to shadow any others. 3478 OverloadCandidateSet OCS(LookupLoc, OverloadCandidateSet::CSK_Normal); 3479 DeclContext::lookup_result R = RD->lookup(Name); 3480 3481 if (R.empty()) { 3482 // We might have no default constructor because we have a lambda's closure 3483 // type, rather than because there's some other declared constructor. 3484 // Every class has a copy/move constructor, copy/move assignment, and 3485 // destructor. 3486 assert(SM == CXXDefaultConstructor && 3487 "lookup for a constructor or assignment operator was empty"); 3488 Result->setMethod(nullptr); 3489 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 3490 return *Result; 3491 } 3492 3493 // Copy the candidates as our processing of them may load new declarations 3494 // from an external source and invalidate lookup_result. 3495 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end()); 3496 3497 for (NamedDecl *CandDecl : Candidates) { 3498 if (CandDecl->isInvalidDecl()) 3499 continue; 3500 3501 DeclAccessPair Cand = DeclAccessPair::make(CandDecl, AS_public); 3502 auto CtorInfo = getConstructorInfo(Cand); 3503 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl())) { 3504 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) 3505 AddMethodCandidate(M, Cand, RD, ThisTy, Classification, 3506 llvm::ArrayRef(&Arg, NumArgs), OCS, true); 3507 else if (CtorInfo) 3508 AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl, 3509 llvm::ArrayRef(&Arg, NumArgs), OCS, 3510 /*SuppressUserConversions*/ true); 3511 else 3512 AddOverloadCandidate(M, Cand, llvm::ArrayRef(&Arg, NumArgs), OCS, 3513 /*SuppressUserConversions*/ true); 3514 } else if (FunctionTemplateDecl *Tmpl = 3515 dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) { 3516 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) 3517 AddMethodTemplateCandidate(Tmpl, Cand, RD, nullptr, ThisTy, 3518 Classification, 3519 llvm::ArrayRef(&Arg, NumArgs), OCS, true); 3520 else if (CtorInfo) 3521 AddTemplateOverloadCandidate(CtorInfo.ConstructorTmpl, 3522 CtorInfo.FoundDecl, nullptr, 3523 llvm::ArrayRef(&Arg, NumArgs), OCS, true); 3524 else 3525 AddTemplateOverloadCandidate(Tmpl, Cand, nullptr, 3526 llvm::ArrayRef(&Arg, NumArgs), OCS, true); 3527 } else { 3528 assert(isa<UsingDecl>(Cand.getDecl()) && 3529 "illegal Kind of operator = Decl"); 3530 } 3531 } 3532 3533 OverloadCandidateSet::iterator Best; 3534 switch (OCS.BestViableFunction(*this, LookupLoc, Best)) { 3535 case OR_Success: 3536 Result->setMethod(cast<CXXMethodDecl>(Best->Function)); 3537 Result->setKind(SpecialMemberOverloadResult::Success); 3538 break; 3539 3540 case OR_Deleted: 3541 Result->setMethod(cast<CXXMethodDecl>(Best->Function)); 3542 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 3543 break; 3544 3545 case OR_Ambiguous: 3546 Result->setMethod(nullptr); 3547 Result->setKind(SpecialMemberOverloadResult::Ambiguous); 3548 break; 3549 3550 case OR_No_Viable_Function: 3551 Result->setMethod(nullptr); 3552 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 3553 break; 3554 } 3555 3556 return *Result; 3557 } 3558 3559 /// Look up the default constructor for the given class. 3560 CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) { 3561 SpecialMemberOverloadResult Result = 3562 LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false, 3563 false, false); 3564 3565 return cast_or_null<CXXConstructorDecl>(Result.getMethod()); 3566 } 3567 3568 /// Look up the copying constructor for the given class. 3569 CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class, 3570 unsigned Quals) { 3571 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 3572 "non-const, non-volatile qualifiers for copy ctor arg"); 3573 SpecialMemberOverloadResult Result = 3574 LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const, 3575 Quals & Qualifiers::Volatile, false, false, false); 3576 3577 return cast_or_null<CXXConstructorDecl>(Result.getMethod()); 3578 } 3579 3580 /// Look up the moving constructor for the given class. 3581 CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class, 3582 unsigned Quals) { 3583 SpecialMemberOverloadResult Result = 3584 LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const, 3585 Quals & Qualifiers::Volatile, false, false, false); 3586 3587 return cast_or_null<CXXConstructorDecl>(Result.getMethod()); 3588 } 3589 3590 /// Look up the constructors for the given class. 3591 DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) { 3592 // If the implicit constructors have not yet been declared, do so now. 3593 if (CanDeclareSpecialMemberFunction(Class)) { 3594 runWithSufficientStackSpace(Class->getLocation(), [&] { 3595 if (Class->needsImplicitDefaultConstructor()) 3596 DeclareImplicitDefaultConstructor(Class); 3597 if (Class->needsImplicitCopyConstructor()) 3598 DeclareImplicitCopyConstructor(Class); 3599 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor()) 3600 DeclareImplicitMoveConstructor(Class); 3601 }); 3602 } 3603 3604 CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class)); 3605 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T); 3606 return Class->lookup(Name); 3607 } 3608 3609 /// Look up the copying assignment operator for the given class. 3610 CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class, 3611 unsigned Quals, bool RValueThis, 3612 unsigned ThisQuals) { 3613 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 3614 "non-const, non-volatile qualifiers for copy assignment arg"); 3615 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 3616 "non-const, non-volatile qualifiers for copy assignment this"); 3617 SpecialMemberOverloadResult Result = 3618 LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const, 3619 Quals & Qualifiers::Volatile, RValueThis, 3620 ThisQuals & Qualifiers::Const, 3621 ThisQuals & Qualifiers::Volatile); 3622 3623 return Result.getMethod(); 3624 } 3625 3626 /// Look up the moving assignment operator for the given class. 3627 CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class, 3628 unsigned Quals, 3629 bool RValueThis, 3630 unsigned ThisQuals) { 3631 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 3632 "non-const, non-volatile qualifiers for copy assignment this"); 3633 SpecialMemberOverloadResult Result = 3634 LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const, 3635 Quals & Qualifiers::Volatile, RValueThis, 3636 ThisQuals & Qualifiers::Const, 3637 ThisQuals & Qualifiers::Volatile); 3638 3639 return Result.getMethod(); 3640 } 3641 3642 /// Look for the destructor of the given class. 3643 /// 3644 /// During semantic analysis, this routine should be used in lieu of 3645 /// CXXRecordDecl::getDestructor(). 3646 /// 3647 /// \returns The destructor for this class. 3648 CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) { 3649 return cast_or_null<CXXDestructorDecl>( 3650 LookupSpecialMember(Class, CXXDestructor, false, false, false, false, 3651 false) 3652 .getMethod()); 3653 } 3654 3655 /// LookupLiteralOperator - Determine which literal operator should be used for 3656 /// a user-defined literal, per C++11 [lex.ext]. 3657 /// 3658 /// Normal overload resolution is not used to select which literal operator to 3659 /// call for a user-defined literal. Look up the provided literal operator name, 3660 /// and filter the results to the appropriate set for the given argument types. 3661 Sema::LiteralOperatorLookupResult 3662 Sema::LookupLiteralOperator(Scope *S, LookupResult &R, 3663 ArrayRef<QualType> ArgTys, bool AllowRaw, 3664 bool AllowTemplate, bool AllowStringTemplatePack, 3665 bool DiagnoseMissing, StringLiteral *StringLit) { 3666 LookupName(R, S); 3667 assert(R.getResultKind() != LookupResult::Ambiguous && 3668 "literal operator lookup can't be ambiguous"); 3669 3670 // Filter the lookup results appropriately. 3671 LookupResult::Filter F = R.makeFilter(); 3672 3673 bool AllowCooked = true; 3674 bool FoundRaw = false; 3675 bool FoundTemplate = false; 3676 bool FoundStringTemplatePack = false; 3677 bool FoundCooked = false; 3678 3679 while (F.hasNext()) { 3680 Decl *D = F.next(); 3681 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D)) 3682 D = USD->getTargetDecl(); 3683 3684 // If the declaration we found is invalid, skip it. 3685 if (D->isInvalidDecl()) { 3686 F.erase(); 3687 continue; 3688 } 3689 3690 bool IsRaw = false; 3691 bool IsTemplate = false; 3692 bool IsStringTemplatePack = false; 3693 bool IsCooked = false; 3694 3695 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3696 if (FD->getNumParams() == 1 && 3697 FD->getParamDecl(0)->getType()->getAs<PointerType>()) 3698 IsRaw = true; 3699 else if (FD->getNumParams() == ArgTys.size()) { 3700 IsCooked = true; 3701 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) { 3702 QualType ParamTy = FD->getParamDecl(ArgIdx)->getType(); 3703 if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) { 3704 IsCooked = false; 3705 break; 3706 } 3707 } 3708 } 3709 } 3710 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) { 3711 TemplateParameterList *Params = FD->getTemplateParameters(); 3712 if (Params->size() == 1) { 3713 IsTemplate = true; 3714 if (!Params->getParam(0)->isTemplateParameterPack() && !StringLit) { 3715 // Implied but not stated: user-defined integer and floating literals 3716 // only ever use numeric literal operator templates, not templates 3717 // taking a parameter of class type. 3718 F.erase(); 3719 continue; 3720 } 3721 3722 // A string literal template is only considered if the string literal 3723 // is a well-formed template argument for the template parameter. 3724 if (StringLit) { 3725 SFINAETrap Trap(*this); 3726 SmallVector<TemplateArgument, 1> SugaredChecked, CanonicalChecked; 3727 TemplateArgumentLoc Arg(TemplateArgument(StringLit), StringLit); 3728 if (CheckTemplateArgument( 3729 Params->getParam(0), Arg, FD, R.getNameLoc(), R.getNameLoc(), 3730 0, SugaredChecked, CanonicalChecked, CTAK_Specified) || 3731 Trap.hasErrorOccurred()) 3732 IsTemplate = false; 3733 } 3734 } else { 3735 IsStringTemplatePack = true; 3736 } 3737 } 3738 3739 if (AllowTemplate && StringLit && IsTemplate) { 3740 FoundTemplate = true; 3741 AllowRaw = false; 3742 AllowCooked = false; 3743 AllowStringTemplatePack = false; 3744 if (FoundRaw || FoundCooked || FoundStringTemplatePack) { 3745 F.restart(); 3746 FoundRaw = FoundCooked = FoundStringTemplatePack = false; 3747 } 3748 } else if (AllowCooked && IsCooked) { 3749 FoundCooked = true; 3750 AllowRaw = false; 3751 AllowTemplate = StringLit; 3752 AllowStringTemplatePack = false; 3753 if (FoundRaw || FoundTemplate || FoundStringTemplatePack) { 3754 // Go through again and remove the raw and template decls we've 3755 // already found. 3756 F.restart(); 3757 FoundRaw = FoundTemplate = FoundStringTemplatePack = false; 3758 } 3759 } else if (AllowRaw && IsRaw) { 3760 FoundRaw = true; 3761 } else if (AllowTemplate && IsTemplate) { 3762 FoundTemplate = true; 3763 } else if (AllowStringTemplatePack && IsStringTemplatePack) { 3764 FoundStringTemplatePack = true; 3765 } else { 3766 F.erase(); 3767 } 3768 } 3769 3770 F.done(); 3771 3772 // Per C++20 [lex.ext]p5, we prefer the template form over the non-template 3773 // form for string literal operator templates. 3774 if (StringLit && FoundTemplate) 3775 return LOLR_Template; 3776 3777 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching 3778 // parameter type, that is used in preference to a raw literal operator 3779 // or literal operator template. 3780 if (FoundCooked) 3781 return LOLR_Cooked; 3782 3783 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal 3784 // operator template, but not both. 3785 if (FoundRaw && FoundTemplate) { 3786 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName(); 3787 for (const NamedDecl *D : R) 3788 NoteOverloadCandidate(D, D->getUnderlyingDecl()->getAsFunction()); 3789 return LOLR_Error; 3790 } 3791 3792 if (FoundRaw) 3793 return LOLR_Raw; 3794 3795 if (FoundTemplate) 3796 return LOLR_Template; 3797 3798 if (FoundStringTemplatePack) 3799 return LOLR_StringTemplatePack; 3800 3801 // Didn't find anything we could use. 3802 if (DiagnoseMissing) { 3803 Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator) 3804 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0] 3805 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw 3806 << (AllowTemplate || AllowStringTemplatePack); 3807 return LOLR_Error; 3808 } 3809 3810 return LOLR_ErrorNoDiagnostic; 3811 } 3812 3813 void ADLResult::insert(NamedDecl *New) { 3814 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())]; 3815 3816 // If we haven't yet seen a decl for this key, or the last decl 3817 // was exactly this one, we're done. 3818 if (Old == nullptr || Old == New) { 3819 Old = New; 3820 return; 3821 } 3822 3823 // Otherwise, decide which is a more recent redeclaration. 3824 FunctionDecl *OldFD = Old->getAsFunction(); 3825 FunctionDecl *NewFD = New->getAsFunction(); 3826 3827 FunctionDecl *Cursor = NewFD; 3828 while (true) { 3829 Cursor = Cursor->getPreviousDecl(); 3830 3831 // If we got to the end without finding OldFD, OldFD is the newer 3832 // declaration; leave things as they are. 3833 if (!Cursor) return; 3834 3835 // If we do find OldFD, then NewFD is newer. 3836 if (Cursor == OldFD) break; 3837 3838 // Otherwise, keep looking. 3839 } 3840 3841 Old = New; 3842 } 3843 3844 void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc, 3845 ArrayRef<Expr *> Args, ADLResult &Result) { 3846 // Find all of the associated namespaces and classes based on the 3847 // arguments we have. 3848 AssociatedNamespaceSet AssociatedNamespaces; 3849 AssociatedClassSet AssociatedClasses; 3850 FindAssociatedClassesAndNamespaces(Loc, Args, 3851 AssociatedNamespaces, 3852 AssociatedClasses); 3853 3854 // C++ [basic.lookup.argdep]p3: 3855 // Let X be the lookup set produced by unqualified lookup (3.4.1) 3856 // and let Y be the lookup set produced by argument dependent 3857 // lookup (defined as follows). If X contains [...] then Y is 3858 // empty. Otherwise Y is the set of declarations found in the 3859 // namespaces associated with the argument types as described 3860 // below. The set of declarations found by the lookup of the name 3861 // is the union of X and Y. 3862 // 3863 // Here, we compute Y and add its members to the overloaded 3864 // candidate set. 3865 for (auto *NS : AssociatedNamespaces) { 3866 // When considering an associated namespace, the lookup is the 3867 // same as the lookup performed when the associated namespace is 3868 // used as a qualifier (3.4.3.2) except that: 3869 // 3870 // -- Any using-directives in the associated namespace are 3871 // ignored. 3872 // 3873 // -- Any namespace-scope friend functions declared in 3874 // associated classes are visible within their respective 3875 // namespaces even if they are not visible during an ordinary 3876 // lookup (11.4). 3877 // 3878 // C++20 [basic.lookup.argdep] p4.3 3879 // -- are exported, are attached to a named module M, do not appear 3880 // in the translation unit containing the point of the lookup, and 3881 // have the same innermost enclosing non-inline namespace scope as 3882 // a declaration of an associated entity attached to M. 3883 DeclContext::lookup_result R = NS->lookup(Name); 3884 for (auto *D : R) { 3885 auto *Underlying = D; 3886 if (auto *USD = dyn_cast<UsingShadowDecl>(D)) 3887 Underlying = USD->getTargetDecl(); 3888 3889 if (!isa<FunctionDecl>(Underlying) && 3890 !isa<FunctionTemplateDecl>(Underlying)) 3891 continue; 3892 3893 // The declaration is visible to argument-dependent lookup if either 3894 // it's ordinarily visible or declared as a friend in an associated 3895 // class. 3896 bool Visible = false; 3897 for (D = D->getMostRecentDecl(); D; 3898 D = cast_or_null<NamedDecl>(D->getPreviousDecl())) { 3899 if (D->getIdentifierNamespace() & Decl::IDNS_Ordinary) { 3900 if (isVisible(D)) { 3901 Visible = true; 3902 break; 3903 } 3904 3905 if (!getLangOpts().CPlusPlusModules) 3906 continue; 3907 3908 if (D->isInExportDeclContext()) { 3909 Module *FM = D->getOwningModule(); 3910 // C++20 [basic.lookup.argdep] p4.3 .. are exported ... 3911 // exports are only valid in module purview and outside of any 3912 // PMF (although a PMF should not even be present in a module 3913 // with an import). 3914 assert(FM && FM->isNamedModule() && !FM->isPrivateModule() && 3915 "bad export context"); 3916 // .. are attached to a named module M, do not appear in the 3917 // translation unit containing the point of the lookup.. 3918 if (D->isInAnotherModuleUnit() && 3919 llvm::any_of(AssociatedClasses, [&](auto *E) { 3920 // ... and have the same innermost enclosing non-inline 3921 // namespace scope as a declaration of an associated entity 3922 // attached to M 3923 if (E->getOwningModule() != FM) 3924 return false; 3925 // TODO: maybe this could be cached when generating the 3926 // associated namespaces / entities. 3927 DeclContext *Ctx = E->getDeclContext(); 3928 while (!Ctx->isFileContext() || Ctx->isInlineNamespace()) 3929 Ctx = Ctx->getParent(); 3930 return Ctx == NS; 3931 })) { 3932 Visible = true; 3933 break; 3934 } 3935 } 3936 } else if (D->getFriendObjectKind()) { 3937 auto *RD = cast<CXXRecordDecl>(D->getLexicalDeclContext()); 3938 // [basic.lookup.argdep]p4: 3939 // Argument-dependent lookup finds all declarations of functions and 3940 // function templates that 3941 // - ... 3942 // - are declared as a friend ([class.friend]) of any class with a 3943 // reachable definition in the set of associated entities, 3944 // 3945 // FIXME: If there's a merged definition of D that is reachable, then 3946 // the friend declaration should be considered. 3947 if (AssociatedClasses.count(RD) && isReachable(D)) { 3948 Visible = true; 3949 break; 3950 } 3951 } 3952 } 3953 3954 // FIXME: Preserve D as the FoundDecl. 3955 if (Visible) 3956 Result.insert(Underlying); 3957 } 3958 } 3959 } 3960 3961 //---------------------------------------------------------------------------- 3962 // Search for all visible declarations. 3963 //---------------------------------------------------------------------------- 3964 VisibleDeclConsumer::~VisibleDeclConsumer() { } 3965 3966 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; } 3967 3968 namespace { 3969 3970 class ShadowContextRAII; 3971 3972 class VisibleDeclsRecord { 3973 public: 3974 /// An entry in the shadow map, which is optimized to store a 3975 /// single declaration (the common case) but can also store a list 3976 /// of declarations. 3977 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry; 3978 3979 private: 3980 /// A mapping from declaration names to the declarations that have 3981 /// this name within a particular scope. 3982 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap; 3983 3984 /// A list of shadow maps, which is used to model name hiding. 3985 std::list<ShadowMap> ShadowMaps; 3986 3987 /// The declaration contexts we have already visited. 3988 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts; 3989 3990 friend class ShadowContextRAII; 3991 3992 public: 3993 /// Determine whether we have already visited this context 3994 /// (and, if not, note that we are going to visit that context now). 3995 bool visitedContext(DeclContext *Ctx) { 3996 return !VisitedContexts.insert(Ctx).second; 3997 } 3998 3999 bool alreadyVisitedContext(DeclContext *Ctx) { 4000 return VisitedContexts.count(Ctx); 4001 } 4002 4003 /// Determine whether the given declaration is hidden in the 4004 /// current scope. 4005 /// 4006 /// \returns the declaration that hides the given declaration, or 4007 /// NULL if no such declaration exists. 4008 NamedDecl *checkHidden(NamedDecl *ND); 4009 4010 /// Add a declaration to the current shadow map. 4011 void add(NamedDecl *ND) { 4012 ShadowMaps.back()[ND->getDeclName()].push_back(ND); 4013 } 4014 }; 4015 4016 /// RAII object that records when we've entered a shadow context. 4017 class ShadowContextRAII { 4018 VisibleDeclsRecord &Visible; 4019 4020 typedef VisibleDeclsRecord::ShadowMap ShadowMap; 4021 4022 public: 4023 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) { 4024 Visible.ShadowMaps.emplace_back(); 4025 } 4026 4027 ~ShadowContextRAII() { 4028 Visible.ShadowMaps.pop_back(); 4029 } 4030 }; 4031 4032 } // end anonymous namespace 4033 4034 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) { 4035 unsigned IDNS = ND->getIdentifierNamespace(); 4036 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin(); 4037 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend(); 4038 SM != SMEnd; ++SM) { 4039 ShadowMap::iterator Pos = SM->find(ND->getDeclName()); 4040 if (Pos == SM->end()) 4041 continue; 4042 4043 for (auto *D : Pos->second) { 4044 // A tag declaration does not hide a non-tag declaration. 4045 if (D->hasTagIdentifierNamespace() && 4046 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary | 4047 Decl::IDNS_ObjCProtocol))) 4048 continue; 4049 4050 // Protocols are in distinct namespaces from everything else. 4051 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol) 4052 || (IDNS & Decl::IDNS_ObjCProtocol)) && 4053 D->getIdentifierNamespace() != IDNS) 4054 continue; 4055 4056 // Functions and function templates in the same scope overload 4057 // rather than hide. FIXME: Look for hiding based on function 4058 // signatures! 4059 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() && 4060 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() && 4061 SM == ShadowMaps.rbegin()) 4062 continue; 4063 4064 // A shadow declaration that's created by a resolved using declaration 4065 // is not hidden by the same using declaration. 4066 if (isa<UsingShadowDecl>(ND) && isa<UsingDecl>(D) && 4067 cast<UsingShadowDecl>(ND)->getIntroducer() == D) 4068 continue; 4069 4070 // We've found a declaration that hides this one. 4071 return D; 4072 } 4073 } 4074 4075 return nullptr; 4076 } 4077 4078 namespace { 4079 class LookupVisibleHelper { 4080 public: 4081 LookupVisibleHelper(VisibleDeclConsumer &Consumer, bool IncludeDependentBases, 4082 bool LoadExternal) 4083 : Consumer(Consumer), IncludeDependentBases(IncludeDependentBases), 4084 LoadExternal(LoadExternal) {} 4085 4086 void lookupVisibleDecls(Sema &SemaRef, Scope *S, Sema::LookupNameKind Kind, 4087 bool IncludeGlobalScope) { 4088 // Determine the set of using directives available during 4089 // unqualified name lookup. 4090 Scope *Initial = S; 4091 UnqualUsingDirectiveSet UDirs(SemaRef); 4092 if (SemaRef.getLangOpts().CPlusPlus) { 4093 // Find the first namespace or translation-unit scope. 4094 while (S && !isNamespaceOrTranslationUnitScope(S)) 4095 S = S->getParent(); 4096 4097 UDirs.visitScopeChain(Initial, S); 4098 } 4099 UDirs.done(); 4100 4101 // Look for visible declarations. 4102 LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind); 4103 Result.setAllowHidden(Consumer.includeHiddenDecls()); 4104 if (!IncludeGlobalScope) 4105 Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl()); 4106 ShadowContextRAII Shadow(Visited); 4107 lookupInScope(Initial, Result, UDirs); 4108 } 4109 4110 void lookupVisibleDecls(Sema &SemaRef, DeclContext *Ctx, 4111 Sema::LookupNameKind Kind, bool IncludeGlobalScope) { 4112 LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind); 4113 Result.setAllowHidden(Consumer.includeHiddenDecls()); 4114 if (!IncludeGlobalScope) 4115 Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl()); 4116 4117 ShadowContextRAII Shadow(Visited); 4118 lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/true, 4119 /*InBaseClass=*/false); 4120 } 4121 4122 private: 4123 void lookupInDeclContext(DeclContext *Ctx, LookupResult &Result, 4124 bool QualifiedNameLookup, bool InBaseClass) { 4125 if (!Ctx) 4126 return; 4127 4128 // Make sure we don't visit the same context twice. 4129 if (Visited.visitedContext(Ctx->getPrimaryContext())) 4130 return; 4131 4132 Consumer.EnteredContext(Ctx); 4133 4134 // Outside C++, lookup results for the TU live on identifiers. 4135 if (isa<TranslationUnitDecl>(Ctx) && 4136 !Result.getSema().getLangOpts().CPlusPlus) { 4137 auto &S = Result.getSema(); 4138 auto &Idents = S.Context.Idents; 4139 4140 // Ensure all external identifiers are in the identifier table. 4141 if (LoadExternal) 4142 if (IdentifierInfoLookup *External = 4143 Idents.getExternalIdentifierLookup()) { 4144 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers()); 4145 for (StringRef Name = Iter->Next(); !Name.empty(); 4146 Name = Iter->Next()) 4147 Idents.get(Name); 4148 } 4149 4150 // Walk all lookup results in the TU for each identifier. 4151 for (const auto &Ident : Idents) { 4152 for (auto I = S.IdResolver.begin(Ident.getValue()), 4153 E = S.IdResolver.end(); 4154 I != E; ++I) { 4155 if (S.IdResolver.isDeclInScope(*I, Ctx)) { 4156 if (NamedDecl *ND = Result.getAcceptableDecl(*I)) { 4157 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass); 4158 Visited.add(ND); 4159 } 4160 } 4161 } 4162 } 4163 4164 return; 4165 } 4166 4167 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx)) 4168 Result.getSema().ForceDeclarationOfImplicitMembers(Class); 4169 4170 llvm::SmallVector<NamedDecl *, 4> DeclsToVisit; 4171 // We sometimes skip loading namespace-level results (they tend to be huge). 4172 bool Load = LoadExternal || 4173 !(isa<TranslationUnitDecl>(Ctx) || isa<NamespaceDecl>(Ctx)); 4174 // Enumerate all of the results in this context. 4175 for (DeclContextLookupResult R : 4176 Load ? Ctx->lookups() 4177 : Ctx->noload_lookups(/*PreserveInternalState=*/false)) 4178 for (auto *D : R) 4179 // Rather than visit immediately, we put ND into a vector and visit 4180 // all decls, in order, outside of this loop. The reason is that 4181 // Consumer.FoundDecl() and LookupResult::getAcceptableDecl(D) 4182 // may invalidate the iterators used in the two 4183 // loops above. 4184 DeclsToVisit.push_back(D); 4185 4186 for (auto *D : DeclsToVisit) 4187 if (auto *ND = Result.getAcceptableDecl(D)) { 4188 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass); 4189 Visited.add(ND); 4190 } 4191 4192 DeclsToVisit.clear(); 4193 4194 // Traverse using directives for qualified name lookup. 4195 if (QualifiedNameLookup) { 4196 ShadowContextRAII Shadow(Visited); 4197 for (auto *I : Ctx->using_directives()) { 4198 if (!Result.getSema().isVisible(I)) 4199 continue; 4200 lookupInDeclContext(I->getNominatedNamespace(), Result, 4201 QualifiedNameLookup, InBaseClass); 4202 } 4203 } 4204 4205 // Traverse the contexts of inherited C++ classes. 4206 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) { 4207 if (!Record->hasDefinition()) 4208 return; 4209 4210 for (const auto &B : Record->bases()) { 4211 QualType BaseType = B.getType(); 4212 4213 RecordDecl *RD; 4214 if (BaseType->isDependentType()) { 4215 if (!IncludeDependentBases) { 4216 // Don't look into dependent bases, because name lookup can't look 4217 // there anyway. 4218 continue; 4219 } 4220 const auto *TST = BaseType->getAs<TemplateSpecializationType>(); 4221 if (!TST) 4222 continue; 4223 TemplateName TN = TST->getTemplateName(); 4224 const auto *TD = 4225 dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl()); 4226 if (!TD) 4227 continue; 4228 RD = TD->getTemplatedDecl(); 4229 } else { 4230 const auto *Record = BaseType->getAs<RecordType>(); 4231 if (!Record) 4232 continue; 4233 RD = Record->getDecl(); 4234 } 4235 4236 // FIXME: It would be nice to be able to determine whether referencing 4237 // a particular member would be ambiguous. For example, given 4238 // 4239 // struct A { int member; }; 4240 // struct B { int member; }; 4241 // struct C : A, B { }; 4242 // 4243 // void f(C *c) { c->### } 4244 // 4245 // accessing 'member' would result in an ambiguity. However, we 4246 // could be smart enough to qualify the member with the base 4247 // class, e.g., 4248 // 4249 // c->B::member 4250 // 4251 // or 4252 // 4253 // c->A::member 4254 4255 // Find results in this base class (and its bases). 4256 ShadowContextRAII Shadow(Visited); 4257 lookupInDeclContext(RD, Result, QualifiedNameLookup, 4258 /*InBaseClass=*/true); 4259 } 4260 } 4261 4262 // Traverse the contexts of Objective-C classes. 4263 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) { 4264 // Traverse categories. 4265 for (auto *Cat : IFace->visible_categories()) { 4266 ShadowContextRAII Shadow(Visited); 4267 lookupInDeclContext(Cat, Result, QualifiedNameLookup, 4268 /*InBaseClass=*/false); 4269 } 4270 4271 // Traverse protocols. 4272 for (auto *I : IFace->all_referenced_protocols()) { 4273 ShadowContextRAII Shadow(Visited); 4274 lookupInDeclContext(I, Result, QualifiedNameLookup, 4275 /*InBaseClass=*/false); 4276 } 4277 4278 // Traverse the superclass. 4279 if (IFace->getSuperClass()) { 4280 ShadowContextRAII Shadow(Visited); 4281 lookupInDeclContext(IFace->getSuperClass(), Result, QualifiedNameLookup, 4282 /*InBaseClass=*/true); 4283 } 4284 4285 // If there is an implementation, traverse it. We do this to find 4286 // synthesized ivars. 4287 if (IFace->getImplementation()) { 4288 ShadowContextRAII Shadow(Visited); 4289 lookupInDeclContext(IFace->getImplementation(), Result, 4290 QualifiedNameLookup, InBaseClass); 4291 } 4292 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) { 4293 for (auto *I : Protocol->protocols()) { 4294 ShadowContextRAII Shadow(Visited); 4295 lookupInDeclContext(I, Result, QualifiedNameLookup, 4296 /*InBaseClass=*/false); 4297 } 4298 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) { 4299 for (auto *I : Category->protocols()) { 4300 ShadowContextRAII Shadow(Visited); 4301 lookupInDeclContext(I, Result, QualifiedNameLookup, 4302 /*InBaseClass=*/false); 4303 } 4304 4305 // If there is an implementation, traverse it. 4306 if (Category->getImplementation()) { 4307 ShadowContextRAII Shadow(Visited); 4308 lookupInDeclContext(Category->getImplementation(), Result, 4309 QualifiedNameLookup, /*InBaseClass=*/true); 4310 } 4311 } 4312 } 4313 4314 void lookupInScope(Scope *S, LookupResult &Result, 4315 UnqualUsingDirectiveSet &UDirs) { 4316 // No clients run in this mode and it's not supported. Please add tests and 4317 // remove the assertion if you start relying on it. 4318 assert(!IncludeDependentBases && "Unsupported flag for lookupInScope"); 4319 4320 if (!S) 4321 return; 4322 4323 if (!S->getEntity() || 4324 (!S->getParent() && !Visited.alreadyVisitedContext(S->getEntity())) || 4325 (S->getEntity())->isFunctionOrMethod()) { 4326 FindLocalExternScope FindLocals(Result); 4327 // Walk through the declarations in this Scope. The consumer might add new 4328 // decls to the scope as part of deserialization, so make a copy first. 4329 SmallVector<Decl *, 8> ScopeDecls(S->decls().begin(), S->decls().end()); 4330 for (Decl *D : ScopeDecls) { 4331 if (NamedDecl *ND = dyn_cast<NamedDecl>(D)) 4332 if ((ND = Result.getAcceptableDecl(ND))) { 4333 Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false); 4334 Visited.add(ND); 4335 } 4336 } 4337 } 4338 4339 DeclContext *Entity = S->getLookupEntity(); 4340 if (Entity) { 4341 // Look into this scope's declaration context, along with any of its 4342 // parent lookup contexts (e.g., enclosing classes), up to the point 4343 // where we hit the context stored in the next outer scope. 4344 DeclContext *OuterCtx = findOuterContext(S); 4345 4346 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx); 4347 Ctx = Ctx->getLookupParent()) { 4348 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 4349 if (Method->isInstanceMethod()) { 4350 // For instance methods, look for ivars in the method's interface. 4351 LookupResult IvarResult(Result.getSema(), Result.getLookupName(), 4352 Result.getNameLoc(), 4353 Sema::LookupMemberName); 4354 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) { 4355 lookupInDeclContext(IFace, IvarResult, 4356 /*QualifiedNameLookup=*/false, 4357 /*InBaseClass=*/false); 4358 } 4359 } 4360 4361 // We've already performed all of the name lookup that we need 4362 // to for Objective-C methods; the next context will be the 4363 // outer scope. 4364 break; 4365 } 4366 4367 if (Ctx->isFunctionOrMethod()) 4368 continue; 4369 4370 lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/false, 4371 /*InBaseClass=*/false); 4372 } 4373 } else if (!S->getParent()) { 4374 // Look into the translation unit scope. We walk through the translation 4375 // unit's declaration context, because the Scope itself won't have all of 4376 // the declarations if we loaded a precompiled header. 4377 // FIXME: We would like the translation unit's Scope object to point to 4378 // the translation unit, so we don't need this special "if" branch. 4379 // However, doing so would force the normal C++ name-lookup code to look 4380 // into the translation unit decl when the IdentifierInfo chains would 4381 // suffice. Once we fix that problem (which is part of a more general 4382 // "don't look in DeclContexts unless we have to" optimization), we can 4383 // eliminate this. 4384 Entity = Result.getSema().Context.getTranslationUnitDecl(); 4385 lookupInDeclContext(Entity, Result, /*QualifiedNameLookup=*/false, 4386 /*InBaseClass=*/false); 4387 } 4388 4389 if (Entity) { 4390 // Lookup visible declarations in any namespaces found by using 4391 // directives. 4392 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity)) 4393 lookupInDeclContext( 4394 const_cast<DeclContext *>(UUE.getNominatedNamespace()), Result, 4395 /*QualifiedNameLookup=*/false, 4396 /*InBaseClass=*/false); 4397 } 4398 4399 // Lookup names in the parent scope. 4400 ShadowContextRAII Shadow(Visited); 4401 lookupInScope(S->getParent(), Result, UDirs); 4402 } 4403 4404 private: 4405 VisibleDeclsRecord Visited; 4406 VisibleDeclConsumer &Consumer; 4407 bool IncludeDependentBases; 4408 bool LoadExternal; 4409 }; 4410 } // namespace 4411 4412 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind, 4413 VisibleDeclConsumer &Consumer, 4414 bool IncludeGlobalScope, bool LoadExternal) { 4415 LookupVisibleHelper H(Consumer, /*IncludeDependentBases=*/false, 4416 LoadExternal); 4417 H.lookupVisibleDecls(*this, S, Kind, IncludeGlobalScope); 4418 } 4419 4420 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind, 4421 VisibleDeclConsumer &Consumer, 4422 bool IncludeGlobalScope, 4423 bool IncludeDependentBases, bool LoadExternal) { 4424 LookupVisibleHelper H(Consumer, IncludeDependentBases, LoadExternal); 4425 H.lookupVisibleDecls(*this, Ctx, Kind, IncludeGlobalScope); 4426 } 4427 4428 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name. 4429 /// If GnuLabelLoc is a valid source location, then this is a definition 4430 /// of an __label__ label name, otherwise it is a normal label definition 4431 /// or use. 4432 LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc, 4433 SourceLocation GnuLabelLoc) { 4434 // Do a lookup to see if we have a label with this name already. 4435 NamedDecl *Res = nullptr; 4436 4437 if (GnuLabelLoc.isValid()) { 4438 // Local label definitions always shadow existing labels. 4439 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc); 4440 Scope *S = CurScope; 4441 PushOnScopeChains(Res, S, true); 4442 return cast<LabelDecl>(Res); 4443 } 4444 4445 // Not a GNU local label. 4446 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration); 4447 // If we found a label, check to see if it is in the same context as us. 4448 // When in a Block, we don't want to reuse a label in an enclosing function. 4449 if (Res && Res->getDeclContext() != CurContext) 4450 Res = nullptr; 4451 if (!Res) { 4452 // If not forward referenced or defined already, create the backing decl. 4453 Res = LabelDecl::Create(Context, CurContext, Loc, II); 4454 Scope *S = CurScope->getFnParent(); 4455 assert(S && "Not in a function?"); 4456 PushOnScopeChains(Res, S, true); 4457 } 4458 return cast<LabelDecl>(Res); 4459 } 4460 4461 //===----------------------------------------------------------------------===// 4462 // Typo correction 4463 //===----------------------------------------------------------------------===// 4464 4465 static bool isCandidateViable(CorrectionCandidateCallback &CCC, 4466 TypoCorrection &Candidate) { 4467 Candidate.setCallbackDistance(CCC.RankCandidate(Candidate)); 4468 return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance; 4469 } 4470 4471 static void LookupPotentialTypoResult(Sema &SemaRef, 4472 LookupResult &Res, 4473 IdentifierInfo *Name, 4474 Scope *S, CXXScopeSpec *SS, 4475 DeclContext *MemberContext, 4476 bool EnteringContext, 4477 bool isObjCIvarLookup, 4478 bool FindHidden); 4479 4480 /// Check whether the declarations found for a typo correction are 4481 /// visible. Set the correction's RequiresImport flag to true if none of the 4482 /// declarations are visible, false otherwise. 4483 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) { 4484 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end(); 4485 4486 for (/**/; DI != DE; ++DI) 4487 if (!LookupResult::isVisible(SemaRef, *DI)) 4488 break; 4489 // No filtering needed if all decls are visible. 4490 if (DI == DE) { 4491 TC.setRequiresImport(false); 4492 return; 4493 } 4494 4495 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI); 4496 bool AnyVisibleDecls = !NewDecls.empty(); 4497 4498 for (/**/; DI != DE; ++DI) { 4499 if (LookupResult::isVisible(SemaRef, *DI)) { 4500 if (!AnyVisibleDecls) { 4501 // Found a visible decl, discard all hidden ones. 4502 AnyVisibleDecls = true; 4503 NewDecls.clear(); 4504 } 4505 NewDecls.push_back(*DI); 4506 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate()) 4507 NewDecls.push_back(*DI); 4508 } 4509 4510 if (NewDecls.empty()) 4511 TC = TypoCorrection(); 4512 else { 4513 TC.setCorrectionDecls(NewDecls); 4514 TC.setRequiresImport(!AnyVisibleDecls); 4515 } 4516 } 4517 4518 // Fill the supplied vector with the IdentifierInfo pointers for each piece of 4519 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::", 4520 // fill the vector with the IdentifierInfo pointers for "foo" and "bar"). 4521 static void getNestedNameSpecifierIdentifiers( 4522 NestedNameSpecifier *NNS, 4523 SmallVectorImpl<const IdentifierInfo*> &Identifiers) { 4524 if (NestedNameSpecifier *Prefix = NNS->getPrefix()) 4525 getNestedNameSpecifierIdentifiers(Prefix, Identifiers); 4526 else 4527 Identifiers.clear(); 4528 4529 const IdentifierInfo *II = nullptr; 4530 4531 switch (NNS->getKind()) { 4532 case NestedNameSpecifier::Identifier: 4533 II = NNS->getAsIdentifier(); 4534 break; 4535 4536 case NestedNameSpecifier::Namespace: 4537 if (NNS->getAsNamespace()->isAnonymousNamespace()) 4538 return; 4539 II = NNS->getAsNamespace()->getIdentifier(); 4540 break; 4541 4542 case NestedNameSpecifier::NamespaceAlias: 4543 II = NNS->getAsNamespaceAlias()->getIdentifier(); 4544 break; 4545 4546 case NestedNameSpecifier::TypeSpecWithTemplate: 4547 case NestedNameSpecifier::TypeSpec: 4548 II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier(); 4549 break; 4550 4551 case NestedNameSpecifier::Global: 4552 case NestedNameSpecifier::Super: 4553 return; 4554 } 4555 4556 if (II) 4557 Identifiers.push_back(II); 4558 } 4559 4560 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding, 4561 DeclContext *Ctx, bool InBaseClass) { 4562 // Don't consider hidden names for typo correction. 4563 if (Hiding) 4564 return; 4565 4566 // Only consider entities with identifiers for names, ignoring 4567 // special names (constructors, overloaded operators, selectors, 4568 // etc.). 4569 IdentifierInfo *Name = ND->getIdentifier(); 4570 if (!Name) 4571 return; 4572 4573 // Only consider visible declarations and declarations from modules with 4574 // names that exactly match. 4575 if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo) 4576 return; 4577 4578 FoundName(Name->getName()); 4579 } 4580 4581 void TypoCorrectionConsumer::FoundName(StringRef Name) { 4582 // Compute the edit distance between the typo and the name of this 4583 // entity, and add the identifier to the list of results. 4584 addName(Name, nullptr); 4585 } 4586 4587 void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) { 4588 // Compute the edit distance between the typo and this keyword, 4589 // and add the keyword to the list of results. 4590 addName(Keyword, nullptr, nullptr, true); 4591 } 4592 4593 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND, 4594 NestedNameSpecifier *NNS, bool isKeyword) { 4595 // Use a simple length-based heuristic to determine the minimum possible 4596 // edit distance. If the minimum isn't good enough, bail out early. 4597 StringRef TypoStr = Typo->getName(); 4598 unsigned MinED = abs((int)Name.size() - (int)TypoStr.size()); 4599 if (MinED && TypoStr.size() / MinED < 3) 4600 return; 4601 4602 // Compute an upper bound on the allowable edit distance, so that the 4603 // edit-distance algorithm can short-circuit. 4604 unsigned UpperBound = (TypoStr.size() + 2) / 3; 4605 unsigned ED = TypoStr.edit_distance(Name, true, UpperBound); 4606 if (ED > UpperBound) return; 4607 4608 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED); 4609 if (isKeyword) TC.makeKeyword(); 4610 TC.setCorrectionRange(nullptr, Result.getLookupNameInfo()); 4611 addCorrection(TC); 4612 } 4613 4614 static const unsigned MaxTypoDistanceResultSets = 5; 4615 4616 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) { 4617 StringRef TypoStr = Typo->getName(); 4618 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName(); 4619 4620 // For very short typos, ignore potential corrections that have a different 4621 // base identifier from the typo or which have a normalized edit distance 4622 // longer than the typo itself. 4623 if (TypoStr.size() < 3 && 4624 (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size())) 4625 return; 4626 4627 // If the correction is resolved but is not viable, ignore it. 4628 if (Correction.isResolved()) { 4629 checkCorrectionVisibility(SemaRef, Correction); 4630 if (!Correction || !isCandidateViable(*CorrectionValidator, Correction)) 4631 return; 4632 } 4633 4634 TypoResultList &CList = 4635 CorrectionResults[Correction.getEditDistance(false)][Name]; 4636 4637 if (!CList.empty() && !CList.back().isResolved()) 4638 CList.pop_back(); 4639 if (NamedDecl *NewND = Correction.getCorrectionDecl()) { 4640 auto RI = llvm::find_if(CList, [NewND](const TypoCorrection &TypoCorr) { 4641 return TypoCorr.getCorrectionDecl() == NewND; 4642 }); 4643 if (RI != CList.end()) { 4644 // The Correction refers to a decl already in the list. No insertion is 4645 // necessary and all further cases will return. 4646 4647 auto IsDeprecated = [](Decl *D) { 4648 while (D) { 4649 if (D->isDeprecated()) 4650 return true; 4651 D = llvm::dyn_cast_or_null<NamespaceDecl>(D->getDeclContext()); 4652 } 4653 return false; 4654 }; 4655 4656 // Prefer non deprecated Corrections over deprecated and only then 4657 // sort using an alphabetical order. 4658 std::pair<bool, std::string> NewKey = { 4659 IsDeprecated(Correction.getFoundDecl()), 4660 Correction.getAsString(SemaRef.getLangOpts())}; 4661 4662 std::pair<bool, std::string> PrevKey = { 4663 IsDeprecated(RI->getFoundDecl()), 4664 RI->getAsString(SemaRef.getLangOpts())}; 4665 4666 if (NewKey < PrevKey) 4667 *RI = Correction; 4668 return; 4669 } 4670 } 4671 if (CList.empty() || Correction.isResolved()) 4672 CList.push_back(Correction); 4673 4674 while (CorrectionResults.size() > MaxTypoDistanceResultSets) 4675 CorrectionResults.erase(std::prev(CorrectionResults.end())); 4676 } 4677 4678 void TypoCorrectionConsumer::addNamespaces( 4679 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) { 4680 SearchNamespaces = true; 4681 4682 for (auto KNPair : KnownNamespaces) 4683 Namespaces.addNameSpecifier(KNPair.first); 4684 4685 bool SSIsTemplate = false; 4686 if (NestedNameSpecifier *NNS = 4687 (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) { 4688 if (const Type *T = NNS->getAsType()) 4689 SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization; 4690 } 4691 // Do not transform this into an iterator-based loop. The loop body can 4692 // trigger the creation of further types (through lazy deserialization) and 4693 // invalid iterators into this list. 4694 auto &Types = SemaRef.getASTContext().getTypes(); 4695 for (unsigned I = 0; I != Types.size(); ++I) { 4696 const auto *TI = Types[I]; 4697 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) { 4698 CD = CD->getCanonicalDecl(); 4699 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() && 4700 !CD->isUnion() && CD->getIdentifier() && 4701 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) && 4702 (CD->isBeingDefined() || CD->isCompleteDefinition())) 4703 Namespaces.addNameSpecifier(CD); 4704 } 4705 } 4706 } 4707 4708 const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() { 4709 if (++CurrentTCIndex < ValidatedCorrections.size()) 4710 return ValidatedCorrections[CurrentTCIndex]; 4711 4712 CurrentTCIndex = ValidatedCorrections.size(); 4713 while (!CorrectionResults.empty()) { 4714 auto DI = CorrectionResults.begin(); 4715 if (DI->second.empty()) { 4716 CorrectionResults.erase(DI); 4717 continue; 4718 } 4719 4720 auto RI = DI->second.begin(); 4721 if (RI->second.empty()) { 4722 DI->second.erase(RI); 4723 performQualifiedLookups(); 4724 continue; 4725 } 4726 4727 TypoCorrection TC = RI->second.pop_back_val(); 4728 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) { 4729 ValidatedCorrections.push_back(TC); 4730 return ValidatedCorrections[CurrentTCIndex]; 4731 } 4732 } 4733 return ValidatedCorrections[0]; // The empty correction. 4734 } 4735 4736 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) { 4737 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo(); 4738 DeclContext *TempMemberContext = MemberContext; 4739 CXXScopeSpec *TempSS = SS.get(); 4740 retry_lookup: 4741 LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext, 4742 EnteringContext, 4743 CorrectionValidator->IsObjCIvarLookup, 4744 Name == Typo && !Candidate.WillReplaceSpecifier()); 4745 switch (Result.getResultKind()) { 4746 case LookupResult::NotFound: 4747 case LookupResult::NotFoundInCurrentInstantiation: 4748 case LookupResult::FoundUnresolvedValue: 4749 if (TempSS) { 4750 // Immediately retry the lookup without the given CXXScopeSpec 4751 TempSS = nullptr; 4752 Candidate.WillReplaceSpecifier(true); 4753 goto retry_lookup; 4754 } 4755 if (TempMemberContext) { 4756 if (SS && !TempSS) 4757 TempSS = SS.get(); 4758 TempMemberContext = nullptr; 4759 goto retry_lookup; 4760 } 4761 if (SearchNamespaces) 4762 QualifiedResults.push_back(Candidate); 4763 break; 4764 4765 case LookupResult::Ambiguous: 4766 // We don't deal with ambiguities. 4767 break; 4768 4769 case LookupResult::Found: 4770 case LookupResult::FoundOverloaded: 4771 // Store all of the Decls for overloaded symbols 4772 for (auto *TRD : Result) 4773 Candidate.addCorrectionDecl(TRD); 4774 checkCorrectionVisibility(SemaRef, Candidate); 4775 if (!isCandidateViable(*CorrectionValidator, Candidate)) { 4776 if (SearchNamespaces) 4777 QualifiedResults.push_back(Candidate); 4778 break; 4779 } 4780 Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo()); 4781 return true; 4782 } 4783 return false; 4784 } 4785 4786 void TypoCorrectionConsumer::performQualifiedLookups() { 4787 unsigned TypoLen = Typo->getName().size(); 4788 for (const TypoCorrection &QR : QualifiedResults) { 4789 for (const auto &NSI : Namespaces) { 4790 DeclContext *Ctx = NSI.DeclCtx; 4791 const Type *NSType = NSI.NameSpecifier->getAsType(); 4792 4793 // If the current NestedNameSpecifier refers to a class and the 4794 // current correction candidate is the name of that class, then skip 4795 // it as it is unlikely a qualified version of the class' constructor 4796 // is an appropriate correction. 4797 if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() : 4798 nullptr) { 4799 if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo()) 4800 continue; 4801 } 4802 4803 TypoCorrection TC(QR); 4804 TC.ClearCorrectionDecls(); 4805 TC.setCorrectionSpecifier(NSI.NameSpecifier); 4806 TC.setQualifierDistance(NSI.EditDistance); 4807 TC.setCallbackDistance(0); // Reset the callback distance 4808 4809 // If the current correction candidate and namespace combination are 4810 // too far away from the original typo based on the normalized edit 4811 // distance, then skip performing a qualified name lookup. 4812 unsigned TmpED = TC.getEditDistance(true); 4813 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED && 4814 TypoLen / TmpED < 3) 4815 continue; 4816 4817 Result.clear(); 4818 Result.setLookupName(QR.getCorrectionAsIdentifierInfo()); 4819 if (!SemaRef.LookupQualifiedName(Result, Ctx)) 4820 continue; 4821 4822 // Any corrections added below will be validated in subsequent 4823 // iterations of the main while() loop over the Consumer's contents. 4824 switch (Result.getResultKind()) { 4825 case LookupResult::Found: 4826 case LookupResult::FoundOverloaded: { 4827 if (SS && SS->isValid()) { 4828 std::string NewQualified = TC.getAsString(SemaRef.getLangOpts()); 4829 std::string OldQualified; 4830 llvm::raw_string_ostream OldOStream(OldQualified); 4831 SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy()); 4832 OldOStream << Typo->getName(); 4833 // If correction candidate would be an identical written qualified 4834 // identifier, then the existing CXXScopeSpec probably included a 4835 // typedef that didn't get accounted for properly. 4836 if (OldOStream.str() == NewQualified) 4837 break; 4838 } 4839 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end(); 4840 TRD != TRDEnd; ++TRD) { 4841 if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(), 4842 NSType ? NSType->getAsCXXRecordDecl() 4843 : nullptr, 4844 TRD.getPair()) == Sema::AR_accessible) 4845 TC.addCorrectionDecl(*TRD); 4846 } 4847 if (TC.isResolved()) { 4848 TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo()); 4849 addCorrection(TC); 4850 } 4851 break; 4852 } 4853 case LookupResult::NotFound: 4854 case LookupResult::NotFoundInCurrentInstantiation: 4855 case LookupResult::Ambiguous: 4856 case LookupResult::FoundUnresolvedValue: 4857 break; 4858 } 4859 } 4860 } 4861 QualifiedResults.clear(); 4862 } 4863 4864 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet( 4865 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec) 4866 : Context(Context), CurContextChain(buildContextChain(CurContext)) { 4867 if (NestedNameSpecifier *NNS = 4868 CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) { 4869 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier); 4870 NNS->print(SpecifierOStream, Context.getPrintingPolicy()); 4871 4872 getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers); 4873 } 4874 // Build the list of identifiers that would be used for an absolute 4875 // (from the global context) NestedNameSpecifier referring to the current 4876 // context. 4877 for (DeclContext *C : llvm::reverse(CurContextChain)) { 4878 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) 4879 CurContextIdentifiers.push_back(ND->getIdentifier()); 4880 } 4881 4882 // Add the global context as a NestedNameSpecifier 4883 SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()), 4884 NestedNameSpecifier::GlobalSpecifier(Context), 1}; 4885 DistanceMap[1].push_back(SI); 4886 } 4887 4888 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain( 4889 DeclContext *Start) -> DeclContextList { 4890 assert(Start && "Building a context chain from a null context"); 4891 DeclContextList Chain; 4892 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr; 4893 DC = DC->getLookupParent()) { 4894 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC); 4895 if (!DC->isInlineNamespace() && !DC->isTransparentContext() && 4896 !(ND && ND->isAnonymousNamespace())) 4897 Chain.push_back(DC->getPrimaryContext()); 4898 } 4899 return Chain; 4900 } 4901 4902 unsigned 4903 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier( 4904 DeclContextList &DeclChain, NestedNameSpecifier *&NNS) { 4905 unsigned NumSpecifiers = 0; 4906 for (DeclContext *C : llvm::reverse(DeclChain)) { 4907 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) { 4908 NNS = NestedNameSpecifier::Create(Context, NNS, ND); 4909 ++NumSpecifiers; 4910 } else if (auto *RD = dyn_cast_or_null<RecordDecl>(C)) { 4911 NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(), 4912 RD->getTypeForDecl()); 4913 ++NumSpecifiers; 4914 } 4915 } 4916 return NumSpecifiers; 4917 } 4918 4919 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier( 4920 DeclContext *Ctx) { 4921 NestedNameSpecifier *NNS = nullptr; 4922 unsigned NumSpecifiers = 0; 4923 DeclContextList NamespaceDeclChain(buildContextChain(Ctx)); 4924 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain); 4925 4926 // Eliminate common elements from the two DeclContext chains. 4927 for (DeclContext *C : llvm::reverse(CurContextChain)) { 4928 if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C) 4929 break; 4930 NamespaceDeclChain.pop_back(); 4931 } 4932 4933 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain 4934 NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS); 4935 4936 // Add an explicit leading '::' specifier if needed. 4937 if (NamespaceDeclChain.empty()) { 4938 // Rebuild the NestedNameSpecifier as a globally-qualified specifier. 4939 NNS = NestedNameSpecifier::GlobalSpecifier(Context); 4940 NumSpecifiers = 4941 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS); 4942 } else if (NamedDecl *ND = 4943 dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) { 4944 IdentifierInfo *Name = ND->getIdentifier(); 4945 bool SameNameSpecifier = false; 4946 if (llvm::is_contained(CurNameSpecifierIdentifiers, Name)) { 4947 std::string NewNameSpecifier; 4948 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier); 4949 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers; 4950 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers); 4951 NNS->print(SpecifierOStream, Context.getPrintingPolicy()); 4952 SpecifierOStream.flush(); 4953 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier; 4954 } 4955 if (SameNameSpecifier || llvm::is_contained(CurContextIdentifiers, Name)) { 4956 // Rebuild the NestedNameSpecifier as a globally-qualified specifier. 4957 NNS = NestedNameSpecifier::GlobalSpecifier(Context); 4958 NumSpecifiers = 4959 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS); 4960 } 4961 } 4962 4963 // If the built NestedNameSpecifier would be replacing an existing 4964 // NestedNameSpecifier, use the number of component identifiers that 4965 // would need to be changed as the edit distance instead of the number 4966 // of components in the built NestedNameSpecifier. 4967 if (NNS && !CurNameSpecifierIdentifiers.empty()) { 4968 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers; 4969 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers); 4970 NumSpecifiers = 4971 llvm::ComputeEditDistance(llvm::ArrayRef(CurNameSpecifierIdentifiers), 4972 llvm::ArrayRef(NewNameSpecifierIdentifiers)); 4973 } 4974 4975 SpecifierInfo SI = {Ctx, NNS, NumSpecifiers}; 4976 DistanceMap[NumSpecifiers].push_back(SI); 4977 } 4978 4979 /// Perform name lookup for a possible result for typo correction. 4980 static void LookupPotentialTypoResult(Sema &SemaRef, 4981 LookupResult &Res, 4982 IdentifierInfo *Name, 4983 Scope *S, CXXScopeSpec *SS, 4984 DeclContext *MemberContext, 4985 bool EnteringContext, 4986 bool isObjCIvarLookup, 4987 bool FindHidden) { 4988 Res.suppressDiagnostics(); 4989 Res.clear(); 4990 Res.setLookupName(Name); 4991 Res.setAllowHidden(FindHidden); 4992 if (MemberContext) { 4993 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) { 4994 if (isObjCIvarLookup) { 4995 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) { 4996 Res.addDecl(Ivar); 4997 Res.resolveKind(); 4998 return; 4999 } 5000 } 5001 5002 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration( 5003 Name, ObjCPropertyQueryKind::OBJC_PR_query_instance)) { 5004 Res.addDecl(Prop); 5005 Res.resolveKind(); 5006 return; 5007 } 5008 } 5009 5010 SemaRef.LookupQualifiedName(Res, MemberContext); 5011 return; 5012 } 5013 5014 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false, 5015 EnteringContext); 5016 5017 // Fake ivar lookup; this should really be part of 5018 // LookupParsedName. 5019 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) { 5020 if (Method->isInstanceMethod() && Method->getClassInterface() && 5021 (Res.empty() || 5022 (Res.isSingleResult() && 5023 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) { 5024 if (ObjCIvarDecl *IV 5025 = Method->getClassInterface()->lookupInstanceVariable(Name)) { 5026 Res.addDecl(IV); 5027 Res.resolveKind(); 5028 } 5029 } 5030 } 5031 } 5032 5033 /// Add keywords to the consumer as possible typo corrections. 5034 static void AddKeywordsToConsumer(Sema &SemaRef, 5035 TypoCorrectionConsumer &Consumer, 5036 Scope *S, CorrectionCandidateCallback &CCC, 5037 bool AfterNestedNameSpecifier) { 5038 if (AfterNestedNameSpecifier) { 5039 // For 'X::', we know exactly which keywords can appear next. 5040 Consumer.addKeywordResult("template"); 5041 if (CCC.WantExpressionKeywords) 5042 Consumer.addKeywordResult("operator"); 5043 return; 5044 } 5045 5046 if (CCC.WantObjCSuper) 5047 Consumer.addKeywordResult("super"); 5048 5049 if (CCC.WantTypeSpecifiers) { 5050 // Add type-specifier keywords to the set of results. 5051 static const char *const CTypeSpecs[] = { 5052 "char", "const", "double", "enum", "float", "int", "long", "short", 5053 "signed", "struct", "union", "unsigned", "void", "volatile", 5054 "_Complex", "_Imaginary", 5055 // storage-specifiers as well 5056 "extern", "inline", "static", "typedef" 5057 }; 5058 5059 for (const auto *CTS : CTypeSpecs) 5060 Consumer.addKeywordResult(CTS); 5061 5062 if (SemaRef.getLangOpts().C99) 5063 Consumer.addKeywordResult("restrict"); 5064 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) 5065 Consumer.addKeywordResult("bool"); 5066 else if (SemaRef.getLangOpts().C99) 5067 Consumer.addKeywordResult("_Bool"); 5068 5069 if (SemaRef.getLangOpts().CPlusPlus) { 5070 Consumer.addKeywordResult("class"); 5071 Consumer.addKeywordResult("typename"); 5072 Consumer.addKeywordResult("wchar_t"); 5073 5074 if (SemaRef.getLangOpts().CPlusPlus11) { 5075 Consumer.addKeywordResult("char16_t"); 5076 Consumer.addKeywordResult("char32_t"); 5077 Consumer.addKeywordResult("constexpr"); 5078 Consumer.addKeywordResult("decltype"); 5079 Consumer.addKeywordResult("thread_local"); 5080 } 5081 } 5082 5083 if (SemaRef.getLangOpts().GNUKeywords) 5084 Consumer.addKeywordResult("typeof"); 5085 } else if (CCC.WantFunctionLikeCasts) { 5086 static const char *const CastableTypeSpecs[] = { 5087 "char", "double", "float", "int", "long", "short", 5088 "signed", "unsigned", "void" 5089 }; 5090 for (auto *kw : CastableTypeSpecs) 5091 Consumer.addKeywordResult(kw); 5092 } 5093 5094 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) { 5095 Consumer.addKeywordResult("const_cast"); 5096 Consumer.addKeywordResult("dynamic_cast"); 5097 Consumer.addKeywordResult("reinterpret_cast"); 5098 Consumer.addKeywordResult("static_cast"); 5099 } 5100 5101 if (CCC.WantExpressionKeywords) { 5102 Consumer.addKeywordResult("sizeof"); 5103 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) { 5104 Consumer.addKeywordResult("false"); 5105 Consumer.addKeywordResult("true"); 5106 } 5107 5108 if (SemaRef.getLangOpts().CPlusPlus) { 5109 static const char *const CXXExprs[] = { 5110 "delete", "new", "operator", "throw", "typeid" 5111 }; 5112 for (const auto *CE : CXXExprs) 5113 Consumer.addKeywordResult(CE); 5114 5115 if (isa<CXXMethodDecl>(SemaRef.CurContext) && 5116 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance()) 5117 Consumer.addKeywordResult("this"); 5118 5119 if (SemaRef.getLangOpts().CPlusPlus11) { 5120 Consumer.addKeywordResult("alignof"); 5121 Consumer.addKeywordResult("nullptr"); 5122 } 5123 } 5124 5125 if (SemaRef.getLangOpts().C11) { 5126 // FIXME: We should not suggest _Alignof if the alignof macro 5127 // is present. 5128 Consumer.addKeywordResult("_Alignof"); 5129 } 5130 } 5131 5132 if (CCC.WantRemainingKeywords) { 5133 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) { 5134 // Statements. 5135 static const char *const CStmts[] = { 5136 "do", "else", "for", "goto", "if", "return", "switch", "while" }; 5137 for (const auto *CS : CStmts) 5138 Consumer.addKeywordResult(CS); 5139 5140 if (SemaRef.getLangOpts().CPlusPlus) { 5141 Consumer.addKeywordResult("catch"); 5142 Consumer.addKeywordResult("try"); 5143 } 5144 5145 if (S && S->getBreakParent()) 5146 Consumer.addKeywordResult("break"); 5147 5148 if (S && S->getContinueParent()) 5149 Consumer.addKeywordResult("continue"); 5150 5151 if (SemaRef.getCurFunction() && 5152 !SemaRef.getCurFunction()->SwitchStack.empty()) { 5153 Consumer.addKeywordResult("case"); 5154 Consumer.addKeywordResult("default"); 5155 } 5156 } else { 5157 if (SemaRef.getLangOpts().CPlusPlus) { 5158 Consumer.addKeywordResult("namespace"); 5159 Consumer.addKeywordResult("template"); 5160 } 5161 5162 if (S && S->isClassScope()) { 5163 Consumer.addKeywordResult("explicit"); 5164 Consumer.addKeywordResult("friend"); 5165 Consumer.addKeywordResult("mutable"); 5166 Consumer.addKeywordResult("private"); 5167 Consumer.addKeywordResult("protected"); 5168 Consumer.addKeywordResult("public"); 5169 Consumer.addKeywordResult("virtual"); 5170 } 5171 } 5172 5173 if (SemaRef.getLangOpts().CPlusPlus) { 5174 Consumer.addKeywordResult("using"); 5175 5176 if (SemaRef.getLangOpts().CPlusPlus11) 5177 Consumer.addKeywordResult("static_assert"); 5178 } 5179 } 5180 } 5181 5182 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer( 5183 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind, 5184 Scope *S, CXXScopeSpec *SS, CorrectionCandidateCallback &CCC, 5185 DeclContext *MemberContext, bool EnteringContext, 5186 const ObjCObjectPointerType *OPT, bool ErrorRecovery) { 5187 5188 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking || 5189 DisableTypoCorrection) 5190 return nullptr; 5191 5192 // In Microsoft mode, don't perform typo correction in a template member 5193 // function dependent context because it interferes with the "lookup into 5194 // dependent bases of class templates" feature. 5195 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() && 5196 isa<CXXMethodDecl>(CurContext)) 5197 return nullptr; 5198 5199 // We only attempt to correct typos for identifiers. 5200 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 5201 if (!Typo) 5202 return nullptr; 5203 5204 // If the scope specifier itself was invalid, don't try to correct 5205 // typos. 5206 if (SS && SS->isInvalid()) 5207 return nullptr; 5208 5209 // Never try to correct typos during any kind of code synthesis. 5210 if (!CodeSynthesisContexts.empty()) 5211 return nullptr; 5212 5213 // Don't try to correct 'super'. 5214 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier()) 5215 return nullptr; 5216 5217 // Abort if typo correction already failed for this specific typo. 5218 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo); 5219 if (locs != TypoCorrectionFailures.end() && 5220 locs->second.count(TypoName.getLoc())) 5221 return nullptr; 5222 5223 // Don't try to correct the identifier "vector" when in AltiVec mode. 5224 // TODO: Figure out why typo correction misbehaves in this case, fix it, and 5225 // remove this workaround. 5226 if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector")) 5227 return nullptr; 5228 5229 // Provide a stop gap for files that are just seriously broken. Trying 5230 // to correct all typos can turn into a HUGE performance penalty, causing 5231 // some files to take minutes to get rejected by the parser. 5232 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit; 5233 if (Limit && TyposCorrected >= Limit) 5234 return nullptr; 5235 ++TyposCorrected; 5236 5237 // If we're handling a missing symbol error, using modules, and the 5238 // special search all modules option is used, look for a missing import. 5239 if (ErrorRecovery && getLangOpts().Modules && 5240 getLangOpts().ModulesSearchAll) { 5241 // The following has the side effect of loading the missing module. 5242 getModuleLoader().lookupMissingImports(Typo->getName(), 5243 TypoName.getBeginLoc()); 5244 } 5245 5246 // Extend the lifetime of the callback. We delayed this until here 5247 // to avoid allocations in the hot path (which is where no typo correction 5248 // occurs). Note that CorrectionCandidateCallback is polymorphic and 5249 // initially stack-allocated. 5250 std::unique_ptr<CorrectionCandidateCallback> ClonedCCC = CCC.clone(); 5251 auto Consumer = std::make_unique<TypoCorrectionConsumer>( 5252 *this, TypoName, LookupKind, S, SS, std::move(ClonedCCC), MemberContext, 5253 EnteringContext); 5254 5255 // Perform name lookup to find visible, similarly-named entities. 5256 bool IsUnqualifiedLookup = false; 5257 DeclContext *QualifiedDC = MemberContext; 5258 if (MemberContext) { 5259 LookupVisibleDecls(MemberContext, LookupKind, *Consumer); 5260 5261 // Look in qualified interfaces. 5262 if (OPT) { 5263 for (auto *I : OPT->quals()) 5264 LookupVisibleDecls(I, LookupKind, *Consumer); 5265 } 5266 } else if (SS && SS->isSet()) { 5267 QualifiedDC = computeDeclContext(*SS, EnteringContext); 5268 if (!QualifiedDC) 5269 return nullptr; 5270 5271 LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer); 5272 } else { 5273 IsUnqualifiedLookup = true; 5274 } 5275 5276 // Determine whether we are going to search in the various namespaces for 5277 // corrections. 5278 bool SearchNamespaces 5279 = getLangOpts().CPlusPlus && 5280 (IsUnqualifiedLookup || (SS && SS->isSet())); 5281 5282 if (IsUnqualifiedLookup || SearchNamespaces) { 5283 // For unqualified lookup, look through all of the names that we have 5284 // seen in this translation unit. 5285 // FIXME: Re-add the ability to skip very unlikely potential corrections. 5286 for (const auto &I : Context.Idents) 5287 Consumer->FoundName(I.getKey()); 5288 5289 // Walk through identifiers in external identifier sources. 5290 // FIXME: Re-add the ability to skip very unlikely potential corrections. 5291 if (IdentifierInfoLookup *External 5292 = Context.Idents.getExternalIdentifierLookup()) { 5293 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers()); 5294 do { 5295 StringRef Name = Iter->Next(); 5296 if (Name.empty()) 5297 break; 5298 5299 Consumer->FoundName(Name); 5300 } while (true); 5301 } 5302 } 5303 5304 AddKeywordsToConsumer(*this, *Consumer, S, 5305 *Consumer->getCorrectionValidator(), 5306 SS && SS->isNotEmpty()); 5307 5308 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going 5309 // to search those namespaces. 5310 if (SearchNamespaces) { 5311 // Load any externally-known namespaces. 5312 if (ExternalSource && !LoadedExternalKnownNamespaces) { 5313 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces; 5314 LoadedExternalKnownNamespaces = true; 5315 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces); 5316 for (auto *N : ExternalKnownNamespaces) 5317 KnownNamespaces[N] = true; 5318 } 5319 5320 Consumer->addNamespaces(KnownNamespaces); 5321 } 5322 5323 return Consumer; 5324 } 5325 5326 /// Try to "correct" a typo in the source code by finding 5327 /// visible declarations whose names are similar to the name that was 5328 /// present in the source code. 5329 /// 5330 /// \param TypoName the \c DeclarationNameInfo structure that contains 5331 /// the name that was present in the source code along with its location. 5332 /// 5333 /// \param LookupKind the name-lookup criteria used to search for the name. 5334 /// 5335 /// \param S the scope in which name lookup occurs. 5336 /// 5337 /// \param SS the nested-name-specifier that precedes the name we're 5338 /// looking for, if present. 5339 /// 5340 /// \param CCC A CorrectionCandidateCallback object that provides further 5341 /// validation of typo correction candidates. It also provides flags for 5342 /// determining the set of keywords permitted. 5343 /// 5344 /// \param MemberContext if non-NULL, the context in which to look for 5345 /// a member access expression. 5346 /// 5347 /// \param EnteringContext whether we're entering the context described by 5348 /// the nested-name-specifier SS. 5349 /// 5350 /// \param OPT when non-NULL, the search for visible declarations will 5351 /// also walk the protocols in the qualified interfaces of \p OPT. 5352 /// 5353 /// \returns a \c TypoCorrection containing the corrected name if the typo 5354 /// along with information such as the \c NamedDecl where the corrected name 5355 /// was declared, and any additional \c NestedNameSpecifier needed to access 5356 /// it (C++ only). The \c TypoCorrection is empty if there is no correction. 5357 TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName, 5358 Sema::LookupNameKind LookupKind, 5359 Scope *S, CXXScopeSpec *SS, 5360 CorrectionCandidateCallback &CCC, 5361 CorrectTypoKind Mode, 5362 DeclContext *MemberContext, 5363 bool EnteringContext, 5364 const ObjCObjectPointerType *OPT, 5365 bool RecordFailure) { 5366 // Always let the ExternalSource have the first chance at correction, even 5367 // if we would otherwise have given up. 5368 if (ExternalSource) { 5369 if (TypoCorrection Correction = 5370 ExternalSource->CorrectTypo(TypoName, LookupKind, S, SS, CCC, 5371 MemberContext, EnteringContext, OPT)) 5372 return Correction; 5373 } 5374 5375 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver; 5376 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for 5377 // some instances of CTC_Unknown, while WantRemainingKeywords is true 5378 // for CTC_Unknown but not for CTC_ObjCMessageReceiver. 5379 bool ObjCMessageReceiver = CCC.WantObjCSuper && !CCC.WantRemainingKeywords; 5380 5381 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 5382 auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC, 5383 MemberContext, EnteringContext, 5384 OPT, Mode == CTK_ErrorRecovery); 5385 5386 if (!Consumer) 5387 return TypoCorrection(); 5388 5389 // If we haven't found anything, we're done. 5390 if (Consumer->empty()) 5391 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5392 5393 // Make sure the best edit distance (prior to adding any namespace qualifiers) 5394 // is not more that about a third of the length of the typo's identifier. 5395 unsigned ED = Consumer->getBestEditDistance(true); 5396 unsigned TypoLen = Typo->getName().size(); 5397 if (ED > 0 && TypoLen / ED < 3) 5398 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5399 5400 TypoCorrection BestTC = Consumer->getNextCorrection(); 5401 TypoCorrection SecondBestTC = Consumer->getNextCorrection(); 5402 if (!BestTC) 5403 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5404 5405 ED = BestTC.getEditDistance(); 5406 5407 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) { 5408 // If this was an unqualified lookup and we believe the callback 5409 // object wouldn't have filtered out possible corrections, note 5410 // that no correction was found. 5411 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5412 } 5413 5414 // If only a single name remains, return that result. 5415 if (!SecondBestTC || 5416 SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) { 5417 const TypoCorrection &Result = BestTC; 5418 5419 // Don't correct to a keyword that's the same as the typo; the keyword 5420 // wasn't actually in scope. 5421 if (ED == 0 && Result.isKeyword()) 5422 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5423 5424 TypoCorrection TC = Result; 5425 TC.setCorrectionRange(SS, TypoName); 5426 checkCorrectionVisibility(*this, TC); 5427 return TC; 5428 } else if (SecondBestTC && ObjCMessageReceiver) { 5429 // Prefer 'super' when we're completing in a message-receiver 5430 // context. 5431 5432 if (BestTC.getCorrection().getAsString() != "super") { 5433 if (SecondBestTC.getCorrection().getAsString() == "super") 5434 BestTC = SecondBestTC; 5435 else if ((*Consumer)["super"].front().isKeyword()) 5436 BestTC = (*Consumer)["super"].front(); 5437 } 5438 // Don't correct to a keyword that's the same as the typo; the keyword 5439 // wasn't actually in scope. 5440 if (BestTC.getEditDistance() == 0 || 5441 BestTC.getCorrection().getAsString() != "super") 5442 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5443 5444 BestTC.setCorrectionRange(SS, TypoName); 5445 return BestTC; 5446 } 5447 5448 // Record the failure's location if needed and return an empty correction. If 5449 // this was an unqualified lookup and we believe the callback object did not 5450 // filter out possible corrections, also cache the failure for the typo. 5451 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC); 5452 } 5453 5454 /// Try to "correct" a typo in the source code by finding 5455 /// visible declarations whose names are similar to the name that was 5456 /// present in the source code. 5457 /// 5458 /// \param TypoName the \c DeclarationNameInfo structure that contains 5459 /// the name that was present in the source code along with its location. 5460 /// 5461 /// \param LookupKind the name-lookup criteria used to search for the name. 5462 /// 5463 /// \param S the scope in which name lookup occurs. 5464 /// 5465 /// \param SS the nested-name-specifier that precedes the name we're 5466 /// looking for, if present. 5467 /// 5468 /// \param CCC A CorrectionCandidateCallback object that provides further 5469 /// validation of typo correction candidates. It also provides flags for 5470 /// determining the set of keywords permitted. 5471 /// 5472 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print 5473 /// diagnostics when the actual typo correction is attempted. 5474 /// 5475 /// \param TRC A TypoRecoveryCallback functor that will be used to build an 5476 /// Expr from a typo correction candidate. 5477 /// 5478 /// \param MemberContext if non-NULL, the context in which to look for 5479 /// a member access expression. 5480 /// 5481 /// \param EnteringContext whether we're entering the context described by 5482 /// the nested-name-specifier SS. 5483 /// 5484 /// \param OPT when non-NULL, the search for visible declarations will 5485 /// also walk the protocols in the qualified interfaces of \p OPT. 5486 /// 5487 /// \returns a new \c TypoExpr that will later be replaced in the AST with an 5488 /// Expr representing the result of performing typo correction, or nullptr if 5489 /// typo correction is not possible. If nullptr is returned, no diagnostics will 5490 /// be emitted and it is the responsibility of the caller to emit any that are 5491 /// needed. 5492 TypoExpr *Sema::CorrectTypoDelayed( 5493 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind, 5494 Scope *S, CXXScopeSpec *SS, CorrectionCandidateCallback &CCC, 5495 TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode, 5496 DeclContext *MemberContext, bool EnteringContext, 5497 const ObjCObjectPointerType *OPT) { 5498 auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC, 5499 MemberContext, EnteringContext, 5500 OPT, Mode == CTK_ErrorRecovery); 5501 5502 // Give the external sema source a chance to correct the typo. 5503 TypoCorrection ExternalTypo; 5504 if (ExternalSource && Consumer) { 5505 ExternalTypo = ExternalSource->CorrectTypo( 5506 TypoName, LookupKind, S, SS, *Consumer->getCorrectionValidator(), 5507 MemberContext, EnteringContext, OPT); 5508 if (ExternalTypo) 5509 Consumer->addCorrection(ExternalTypo); 5510 } 5511 5512 if (!Consumer || Consumer->empty()) 5513 return nullptr; 5514 5515 // Make sure the best edit distance (prior to adding any namespace qualifiers) 5516 // is not more that about a third of the length of the typo's identifier. 5517 unsigned ED = Consumer->getBestEditDistance(true); 5518 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 5519 if (!ExternalTypo && ED > 0 && Typo->getName().size() / ED < 3) 5520 return nullptr; 5521 ExprEvalContexts.back().NumTypos++; 5522 return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC), 5523 TypoName.getLoc()); 5524 } 5525 5526 void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) { 5527 if (!CDecl) return; 5528 5529 if (isKeyword()) 5530 CorrectionDecls.clear(); 5531 5532 CorrectionDecls.push_back(CDecl); 5533 5534 if (!CorrectionName) 5535 CorrectionName = CDecl->getDeclName(); 5536 } 5537 5538 std::string TypoCorrection::getAsString(const LangOptions &LO) const { 5539 if (CorrectionNameSpec) { 5540 std::string tmpBuffer; 5541 llvm::raw_string_ostream PrefixOStream(tmpBuffer); 5542 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO)); 5543 PrefixOStream << CorrectionName; 5544 return PrefixOStream.str(); 5545 } 5546 5547 return CorrectionName.getAsString(); 5548 } 5549 5550 bool CorrectionCandidateCallback::ValidateCandidate( 5551 const TypoCorrection &candidate) { 5552 if (!candidate.isResolved()) 5553 return true; 5554 5555 if (candidate.isKeyword()) 5556 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts || 5557 WantRemainingKeywords || WantObjCSuper; 5558 5559 bool HasNonType = false; 5560 bool HasStaticMethod = false; 5561 bool HasNonStaticMethod = false; 5562 for (Decl *D : candidate) { 5563 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D)) 5564 D = FTD->getTemplatedDecl(); 5565 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 5566 if (Method->isStatic()) 5567 HasStaticMethod = true; 5568 else 5569 HasNonStaticMethod = true; 5570 } 5571 if (!isa<TypeDecl>(D)) 5572 HasNonType = true; 5573 } 5574 5575 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod && 5576 !candidate.getCorrectionSpecifier()) 5577 return false; 5578 5579 return WantTypeSpecifiers || HasNonType; 5580 } 5581 5582 FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs, 5583 bool HasExplicitTemplateArgs, 5584 MemberExpr *ME) 5585 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs), 5586 CurContext(SemaRef.CurContext), MemberFn(ME) { 5587 WantTypeSpecifiers = false; 5588 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && 5589 !HasExplicitTemplateArgs && NumArgs == 1; 5590 WantCXXNamedCasts = HasExplicitTemplateArgs && NumArgs == 1; 5591 WantRemainingKeywords = false; 5592 } 5593 5594 bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) { 5595 if (!candidate.getCorrectionDecl()) 5596 return candidate.isKeyword(); 5597 5598 for (auto *C : candidate) { 5599 FunctionDecl *FD = nullptr; 5600 NamedDecl *ND = C->getUnderlyingDecl(); 5601 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 5602 FD = FTD->getTemplatedDecl(); 5603 if (!HasExplicitTemplateArgs && !FD) { 5604 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) { 5605 // If the Decl is neither a function nor a template function, 5606 // determine if it is a pointer or reference to a function. If so, 5607 // check against the number of arguments expected for the pointee. 5608 QualType ValType = cast<ValueDecl>(ND)->getType(); 5609 if (ValType.isNull()) 5610 continue; 5611 if (ValType->isAnyPointerType() || ValType->isReferenceType()) 5612 ValType = ValType->getPointeeType(); 5613 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>()) 5614 if (FPT->getNumParams() == NumArgs) 5615 return true; 5616 } 5617 } 5618 5619 // A typo for a function-style cast can look like a function call in C++. 5620 if ((HasExplicitTemplateArgs ? getAsTypeTemplateDecl(ND) != nullptr 5621 : isa<TypeDecl>(ND)) && 5622 CurContext->getParentASTContext().getLangOpts().CPlusPlus) 5623 // Only a class or class template can take two or more arguments. 5624 return NumArgs <= 1 || HasExplicitTemplateArgs || isa<CXXRecordDecl>(ND); 5625 5626 // Skip the current candidate if it is not a FunctionDecl or does not accept 5627 // the current number of arguments. 5628 if (!FD || !(FD->getNumParams() >= NumArgs && 5629 FD->getMinRequiredArguments() <= NumArgs)) 5630 continue; 5631 5632 // If the current candidate is a non-static C++ method, skip the candidate 5633 // unless the method being corrected--or the current DeclContext, if the 5634 // function being corrected is not a method--is a method in the same class 5635 // or a descendent class of the candidate's parent class. 5636 if (const auto *MD = dyn_cast<CXXMethodDecl>(FD)) { 5637 if (MemberFn || !MD->isStatic()) { 5638 const auto *CurMD = 5639 MemberFn 5640 ? dyn_cast_if_present<CXXMethodDecl>(MemberFn->getMemberDecl()) 5641 : dyn_cast_if_present<CXXMethodDecl>(CurContext); 5642 const CXXRecordDecl *CurRD = 5643 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr; 5644 const CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl(); 5645 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD))) 5646 continue; 5647 } 5648 } 5649 return true; 5650 } 5651 return false; 5652 } 5653 5654 void Sema::diagnoseTypo(const TypoCorrection &Correction, 5655 const PartialDiagnostic &TypoDiag, 5656 bool ErrorRecovery) { 5657 diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl), 5658 ErrorRecovery); 5659 } 5660 5661 /// Find which declaration we should import to provide the definition of 5662 /// the given declaration. 5663 static const NamedDecl *getDefinitionToImport(const NamedDecl *D) { 5664 if (const auto *VD = dyn_cast<VarDecl>(D)) 5665 return VD->getDefinition(); 5666 if (const auto *FD = dyn_cast<FunctionDecl>(D)) 5667 return FD->getDefinition(); 5668 if (const auto *TD = dyn_cast<TagDecl>(D)) 5669 return TD->getDefinition(); 5670 if (const auto *ID = dyn_cast<ObjCInterfaceDecl>(D)) 5671 return ID->getDefinition(); 5672 if (const auto *PD = dyn_cast<ObjCProtocolDecl>(D)) 5673 return PD->getDefinition(); 5674 if (const auto *TD = dyn_cast<TemplateDecl>(D)) 5675 if (const NamedDecl *TTD = TD->getTemplatedDecl()) 5676 return getDefinitionToImport(TTD); 5677 return nullptr; 5678 } 5679 5680 void Sema::diagnoseMissingImport(SourceLocation Loc, const NamedDecl *Decl, 5681 MissingImportKind MIK, bool Recover) { 5682 // Suggest importing a module providing the definition of this entity, if 5683 // possible. 5684 const NamedDecl *Def = getDefinitionToImport(Decl); 5685 if (!Def) 5686 Def = Decl; 5687 5688 Module *Owner = getOwningModule(Def); 5689 assert(Owner && "definition of hidden declaration is not in a module"); 5690 5691 llvm::SmallVector<Module*, 8> OwningModules; 5692 OwningModules.push_back(Owner); 5693 auto Merged = Context.getModulesWithMergedDefinition(Def); 5694 OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end()); 5695 5696 diagnoseMissingImport(Loc, Def, Def->getLocation(), OwningModules, MIK, 5697 Recover); 5698 } 5699 5700 /// Get a "quoted.h" or <angled.h> include path to use in a diagnostic 5701 /// suggesting the addition of a #include of the specified file. 5702 static std::string getHeaderNameForHeader(Preprocessor &PP, FileEntryRef E, 5703 llvm::StringRef IncludingFile) { 5704 bool IsAngled = false; 5705 auto Path = PP.getHeaderSearchInfo().suggestPathToFileForDiagnostics( 5706 E, IncludingFile, &IsAngled); 5707 return (IsAngled ? '<' : '"') + Path + (IsAngled ? '>' : '"'); 5708 } 5709 5710 void Sema::diagnoseMissingImport(SourceLocation UseLoc, const NamedDecl *Decl, 5711 SourceLocation DeclLoc, 5712 ArrayRef<Module *> Modules, 5713 MissingImportKind MIK, bool Recover) { 5714 assert(!Modules.empty()); 5715 5716 // See https://github.com/llvm/llvm-project/issues/73893. It is generally 5717 // confusing than helpful to show the namespace is not visible. 5718 if (isa<NamespaceDecl>(Decl)) 5719 return; 5720 5721 auto NotePrevious = [&] { 5722 // FIXME: Suppress the note backtrace even under 5723 // -fdiagnostics-show-note-include-stack. We don't care how this 5724 // declaration was previously reached. 5725 Diag(DeclLoc, diag::note_unreachable_entity) << (int)MIK; 5726 }; 5727 5728 // Weed out duplicates from module list. 5729 llvm::SmallVector<Module*, 8> UniqueModules; 5730 llvm::SmallDenseSet<Module*, 8> UniqueModuleSet; 5731 for (auto *M : Modules) { 5732 if (M->isExplicitGlobalModule() || M->isPrivateModule()) 5733 continue; 5734 if (UniqueModuleSet.insert(M).second) 5735 UniqueModules.push_back(M); 5736 } 5737 5738 // Try to find a suitable header-name to #include. 5739 std::string HeaderName; 5740 if (OptionalFileEntryRef Header = 5741 PP.getHeaderToIncludeForDiagnostics(UseLoc, DeclLoc)) { 5742 if (const FileEntry *FE = 5743 SourceMgr.getFileEntryForID(SourceMgr.getFileID(UseLoc))) 5744 HeaderName = 5745 getHeaderNameForHeader(PP, *Header, FE->tryGetRealPathName()); 5746 } 5747 5748 // If we have a #include we should suggest, or if all definition locations 5749 // were in global module fragments, don't suggest an import. 5750 if (!HeaderName.empty() || UniqueModules.empty()) { 5751 // FIXME: Find a smart place to suggest inserting a #include, and add 5752 // a FixItHint there. 5753 Diag(UseLoc, diag::err_module_unimported_use_header) 5754 << (int)MIK << Decl << !HeaderName.empty() << HeaderName; 5755 // Produce a note showing where the entity was declared. 5756 NotePrevious(); 5757 if (Recover) 5758 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]); 5759 return; 5760 } 5761 5762 Modules = UniqueModules; 5763 5764 auto GetModuleNameForDiagnostic = [this](const Module *M) -> std::string { 5765 if (M->isModuleMapModule()) 5766 return M->getFullModuleName(); 5767 5768 Module *CurrentModule = getCurrentModule(); 5769 5770 if (M->isImplicitGlobalModule()) 5771 M = M->getTopLevelModule(); 5772 5773 bool IsInTheSameModule = 5774 CurrentModule && CurrentModule->getPrimaryModuleInterfaceName() == 5775 M->getPrimaryModuleInterfaceName(); 5776 5777 // If the current module unit is in the same module with M, it is OK to show 5778 // the partition name. Otherwise, it'll be sufficient to show the primary 5779 // module name. 5780 if (IsInTheSameModule) 5781 return M->getTopLevelModuleName().str(); 5782 else 5783 return M->getPrimaryModuleInterfaceName().str(); 5784 }; 5785 5786 if (Modules.size() > 1) { 5787 std::string ModuleList; 5788 unsigned N = 0; 5789 for (const auto *M : Modules) { 5790 ModuleList += "\n "; 5791 if (++N == 5 && N != Modules.size()) { 5792 ModuleList += "[...]"; 5793 break; 5794 } 5795 ModuleList += GetModuleNameForDiagnostic(M); 5796 } 5797 5798 Diag(UseLoc, diag::err_module_unimported_use_multiple) 5799 << (int)MIK << Decl << ModuleList; 5800 } else { 5801 // FIXME: Add a FixItHint that imports the corresponding module. 5802 Diag(UseLoc, diag::err_module_unimported_use) 5803 << (int)MIK << Decl << GetModuleNameForDiagnostic(Modules[0]); 5804 } 5805 5806 NotePrevious(); 5807 5808 // Try to recover by implicitly importing this module. 5809 if (Recover) 5810 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]); 5811 } 5812 5813 /// Diagnose a successfully-corrected typo. Separated from the correction 5814 /// itself to allow external validation of the result, etc. 5815 /// 5816 /// \param Correction The result of performing typo correction. 5817 /// \param TypoDiag The diagnostic to produce. This will have the corrected 5818 /// string added to it (and usually also a fixit). 5819 /// \param PrevNote A note to use when indicating the location of the entity to 5820 /// which we are correcting. Will have the correction string added to it. 5821 /// \param ErrorRecovery If \c true (the default), the caller is going to 5822 /// recover from the typo as if the corrected string had been typed. 5823 /// In this case, \c PDiag must be an error, and we will attach a fixit 5824 /// to it. 5825 void Sema::diagnoseTypo(const TypoCorrection &Correction, 5826 const PartialDiagnostic &TypoDiag, 5827 const PartialDiagnostic &PrevNote, 5828 bool ErrorRecovery) { 5829 std::string CorrectedStr = Correction.getAsString(getLangOpts()); 5830 std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts()); 5831 FixItHint FixTypo = FixItHint::CreateReplacement( 5832 Correction.getCorrectionRange(), CorrectedStr); 5833 5834 // Maybe we're just missing a module import. 5835 if (Correction.requiresImport()) { 5836 NamedDecl *Decl = Correction.getFoundDecl(); 5837 assert(Decl && "import required but no declaration to import"); 5838 5839 diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl, 5840 MissingImportKind::Declaration, ErrorRecovery); 5841 return; 5842 } 5843 5844 Diag(Correction.getCorrectionRange().getBegin(), TypoDiag) 5845 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint()); 5846 5847 NamedDecl *ChosenDecl = 5848 Correction.isKeyword() ? nullptr : Correction.getFoundDecl(); 5849 if (PrevNote.getDiagID() && ChosenDecl) 5850 Diag(ChosenDecl->getLocation(), PrevNote) 5851 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo); 5852 5853 // Add any extra diagnostics. 5854 for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics()) 5855 Diag(Correction.getCorrectionRange().getBegin(), PD); 5856 } 5857 5858 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC, 5859 TypoDiagnosticGenerator TDG, 5860 TypoRecoveryCallback TRC, 5861 SourceLocation TypoLoc) { 5862 assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer"); 5863 auto TE = new (Context) TypoExpr(Context.DependentTy, TypoLoc); 5864 auto &State = DelayedTypos[TE]; 5865 State.Consumer = std::move(TCC); 5866 State.DiagHandler = std::move(TDG); 5867 State.RecoveryHandler = std::move(TRC); 5868 if (TE) 5869 TypoExprs.push_back(TE); 5870 return TE; 5871 } 5872 5873 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const { 5874 auto Entry = DelayedTypos.find(TE); 5875 assert(Entry != DelayedTypos.end() && 5876 "Failed to get the state for a TypoExpr!"); 5877 return Entry->second; 5878 } 5879 5880 void Sema::clearDelayedTypo(TypoExpr *TE) { 5881 DelayedTypos.erase(TE); 5882 } 5883 5884 void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) { 5885 DeclarationNameInfo Name(II, IILoc); 5886 LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration); 5887 R.suppressDiagnostics(); 5888 R.setHideTags(false); 5889 LookupName(R, S); 5890 R.dump(); 5891 } 5892 5893 void Sema::ActOnPragmaDump(Expr *E) { 5894 E->dump(); 5895 } 5896