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/Scope.h" 33 #include "clang/Sema/ScopeInfo.h" 34 #include "clang/Sema/Sema.h" 35 #include "clang/Sema/SemaInternal.h" 36 #include "clang/Sema/TemplateDeduction.h" 37 #include "clang/Sema/TypoCorrection.h" 38 #include "llvm/ADT/STLExtras.h" 39 #include "llvm/ADT/SmallPtrSet.h" 40 #include "llvm/ADT/TinyPtrVector.h" 41 #include "llvm/ADT/edit_distance.h" 42 #include "llvm/Support/ErrorHandling.h" 43 #include <algorithm> 44 #include <iterator> 45 #include <list> 46 #include <set> 47 #include <utility> 48 #include <vector> 49 50 #include "OpenCLBuiltins.inc" 51 52 using namespace clang; 53 using namespace sema; 54 55 namespace { 56 class UnqualUsingEntry { 57 const DeclContext *Nominated; 58 const DeclContext *CommonAncestor; 59 60 public: 61 UnqualUsingEntry(const DeclContext *Nominated, 62 const DeclContext *CommonAncestor) 63 : Nominated(Nominated), CommonAncestor(CommonAncestor) { 64 } 65 66 const DeclContext *getCommonAncestor() const { 67 return CommonAncestor; 68 } 69 70 const DeclContext *getNominatedNamespace() const { 71 return Nominated; 72 } 73 74 // Sort by the pointer value of the common ancestor. 75 struct Comparator { 76 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) { 77 return L.getCommonAncestor() < R.getCommonAncestor(); 78 } 79 80 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) { 81 return E.getCommonAncestor() < DC; 82 } 83 84 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) { 85 return DC < E.getCommonAncestor(); 86 } 87 }; 88 }; 89 90 /// A collection of using directives, as used by C++ unqualified 91 /// lookup. 92 class UnqualUsingDirectiveSet { 93 Sema &SemaRef; 94 95 typedef SmallVector<UnqualUsingEntry, 8> ListTy; 96 97 ListTy list; 98 llvm::SmallPtrSet<DeclContext*, 8> visited; 99 100 public: 101 UnqualUsingDirectiveSet(Sema &SemaRef) : SemaRef(SemaRef) {} 102 103 void visitScopeChain(Scope *S, Scope *InnermostFileScope) { 104 // C++ [namespace.udir]p1: 105 // During unqualified name lookup, the names appear as if they 106 // were declared in the nearest enclosing namespace which contains 107 // both the using-directive and the nominated namespace. 108 DeclContext *InnermostFileDC = InnermostFileScope->getEntity(); 109 assert(InnermostFileDC && InnermostFileDC->isFileContext()); 110 111 for (; S; S = S->getParent()) { 112 // C++ [namespace.udir]p1: 113 // A using-directive shall not appear in class scope, but may 114 // appear in namespace scope or in block scope. 115 DeclContext *Ctx = S->getEntity(); 116 if (Ctx && Ctx->isFileContext()) { 117 visit(Ctx, Ctx); 118 } else if (!Ctx || Ctx->isFunctionOrMethod()) { 119 for (auto *I : S->using_directives()) 120 if (SemaRef.isVisible(I)) 121 visit(I, InnermostFileDC); 122 } 123 } 124 } 125 126 // Visits a context and collect all of its using directives 127 // recursively. Treats all using directives as if they were 128 // declared in the context. 129 // 130 // A given context is only every visited once, so it is important 131 // that contexts be visited from the inside out in order to get 132 // the effective DCs right. 133 void visit(DeclContext *DC, DeclContext *EffectiveDC) { 134 if (!visited.insert(DC).second) 135 return; 136 137 addUsingDirectives(DC, EffectiveDC); 138 } 139 140 // Visits a using directive and collects all of its using 141 // directives recursively. Treats all using directives as if they 142 // were declared in the effective DC. 143 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 144 DeclContext *NS = UD->getNominatedNamespace(); 145 if (!visited.insert(NS).second) 146 return; 147 148 addUsingDirective(UD, EffectiveDC); 149 addUsingDirectives(NS, EffectiveDC); 150 } 151 152 // Adds all the using directives in a context (and those nominated 153 // by its using directives, transitively) as if they appeared in 154 // the given effective context. 155 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) { 156 SmallVector<DeclContext*, 4> queue; 157 while (true) { 158 for (auto UD : DC->using_directives()) { 159 DeclContext *NS = UD->getNominatedNamespace(); 160 if (SemaRef.isVisible(UD) && visited.insert(NS).second) { 161 addUsingDirective(UD, EffectiveDC); 162 queue.push_back(NS); 163 } 164 } 165 166 if (queue.empty()) 167 return; 168 169 DC = queue.pop_back_val(); 170 } 171 } 172 173 // Add a using directive as if it had been declared in the given 174 // context. This helps implement C++ [namespace.udir]p3: 175 // The using-directive is transitive: if a scope contains a 176 // using-directive that nominates a second namespace that itself 177 // contains using-directives, the effect is as if the 178 // using-directives from the second namespace also appeared in 179 // the first. 180 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 181 // Find the common ancestor between the effective context and 182 // the nominated namespace. 183 DeclContext *Common = UD->getNominatedNamespace(); 184 while (!Common->Encloses(EffectiveDC)) 185 Common = Common->getParent(); 186 Common = Common->getPrimaryContext(); 187 188 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common)); 189 } 190 191 void done() { llvm::sort(list, UnqualUsingEntry::Comparator()); } 192 193 typedef ListTy::const_iterator const_iterator; 194 195 const_iterator begin() const { return list.begin(); } 196 const_iterator end() const { return list.end(); } 197 198 llvm::iterator_range<const_iterator> 199 getNamespacesFor(DeclContext *DC) const { 200 return llvm::make_range(std::equal_range(begin(), end(), 201 DC->getPrimaryContext(), 202 UnqualUsingEntry::Comparator())); 203 } 204 }; 205 } // end anonymous namespace 206 207 // Retrieve the set of identifier namespaces that correspond to a 208 // specific kind of name lookup. 209 static inline unsigned getIDNS(Sema::LookupNameKind NameKind, 210 bool CPlusPlus, 211 bool Redeclaration) { 212 unsigned IDNS = 0; 213 switch (NameKind) { 214 case Sema::LookupObjCImplicitSelfParam: 215 case Sema::LookupOrdinaryName: 216 case Sema::LookupRedeclarationWithLinkage: 217 case Sema::LookupLocalFriendName: 218 case Sema::LookupDestructorName: 219 IDNS = Decl::IDNS_Ordinary; 220 if (CPlusPlus) { 221 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace; 222 if (Redeclaration) 223 IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend; 224 } 225 if (Redeclaration) 226 IDNS |= Decl::IDNS_LocalExtern; 227 break; 228 229 case Sema::LookupOperatorName: 230 // Operator lookup is its own crazy thing; it is not the same 231 // as (e.g.) looking up an operator name for redeclaration. 232 assert(!Redeclaration && "cannot do redeclaration operator lookup"); 233 IDNS = Decl::IDNS_NonMemberOperator; 234 break; 235 236 case Sema::LookupTagName: 237 if (CPlusPlus) { 238 IDNS = Decl::IDNS_Type; 239 240 // When looking for a redeclaration of a tag name, we add: 241 // 1) TagFriend to find undeclared friend decls 242 // 2) Namespace because they can't "overload" with tag decls. 243 // 3) Tag because it includes class templates, which can't 244 // "overload" with tag decls. 245 if (Redeclaration) 246 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace; 247 } else { 248 IDNS = Decl::IDNS_Tag; 249 } 250 break; 251 252 case Sema::LookupLabel: 253 IDNS = Decl::IDNS_Label; 254 break; 255 256 case Sema::LookupMemberName: 257 IDNS = Decl::IDNS_Member; 258 if (CPlusPlus) 259 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary; 260 break; 261 262 case Sema::LookupNestedNameSpecifierName: 263 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace; 264 break; 265 266 case Sema::LookupNamespaceName: 267 IDNS = Decl::IDNS_Namespace; 268 break; 269 270 case Sema::LookupUsingDeclName: 271 assert(Redeclaration && "should only be used for redecl lookup"); 272 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member | 273 Decl::IDNS_Using | Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend | 274 Decl::IDNS_LocalExtern; 275 break; 276 277 case Sema::LookupObjCProtocolName: 278 IDNS = Decl::IDNS_ObjCProtocol; 279 break; 280 281 case Sema::LookupOMPReductionName: 282 IDNS = Decl::IDNS_OMPReduction; 283 break; 284 285 case Sema::LookupOMPMapperName: 286 IDNS = Decl::IDNS_OMPMapper; 287 break; 288 289 case Sema::LookupAnyName: 290 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member 291 | Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol 292 | Decl::IDNS_Type; 293 break; 294 } 295 return IDNS; 296 } 297 298 void LookupResult::configure() { 299 IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus, 300 isForRedeclaration()); 301 302 // If we're looking for one of the allocation or deallocation 303 // operators, make sure that the implicitly-declared new and delete 304 // operators can be found. 305 switch (NameInfo.getName().getCXXOverloadedOperator()) { 306 case OO_New: 307 case OO_Delete: 308 case OO_Array_New: 309 case OO_Array_Delete: 310 getSema().DeclareGlobalNewDelete(); 311 break; 312 313 default: 314 break; 315 } 316 317 // Compiler builtins are always visible, regardless of where they end 318 // up being declared. 319 if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) { 320 if (unsigned BuiltinID = Id->getBuiltinID()) { 321 if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 322 AllowHidden = true; 323 } 324 } 325 } 326 327 bool LookupResult::checkDebugAssumptions() const { 328 // This function is never called by NDEBUG builds. 329 assert(ResultKind != NotFound || Decls.size() == 0); 330 assert(ResultKind != Found || Decls.size() == 1); 331 assert(ResultKind != FoundOverloaded || Decls.size() > 1 || 332 (Decls.size() == 1 && 333 isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl()))); 334 assert(ResultKind != FoundUnresolvedValue || checkUnresolved()); 335 assert(ResultKind != Ambiguous || Decls.size() > 1 || 336 (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects || 337 Ambiguity == AmbiguousBaseSubobjectTypes))); 338 assert((Paths != nullptr) == (ResultKind == Ambiguous && 339 (Ambiguity == AmbiguousBaseSubobjectTypes || 340 Ambiguity == AmbiguousBaseSubobjects))); 341 return true; 342 } 343 344 // Necessary because CXXBasePaths is not complete in Sema.h 345 void LookupResult::deletePaths(CXXBasePaths *Paths) { 346 delete Paths; 347 } 348 349 /// Get a representative context for a declaration such that two declarations 350 /// will have the same context if they were found within the same scope. 351 static DeclContext *getContextForScopeMatching(Decl *D) { 352 // For function-local declarations, use that function as the context. This 353 // doesn't account for scopes within the function; the caller must deal with 354 // those. 355 DeclContext *DC = D->getLexicalDeclContext(); 356 if (DC->isFunctionOrMethod()) 357 return DC; 358 359 // Otherwise, look at the semantic context of the declaration. The 360 // declaration must have been found there. 361 return D->getDeclContext()->getRedeclContext(); 362 } 363 364 /// Determine whether \p D is a better lookup result than \p Existing, 365 /// given that they declare the same entity. 366 static bool isPreferredLookupResult(Sema &S, Sema::LookupNameKind Kind, 367 NamedDecl *D, NamedDecl *Existing) { 368 // When looking up redeclarations of a using declaration, prefer a using 369 // shadow declaration over any other declaration of the same entity. 370 if (Kind == Sema::LookupUsingDeclName && isa<UsingShadowDecl>(D) && 371 !isa<UsingShadowDecl>(Existing)) 372 return true; 373 374 auto *DUnderlying = D->getUnderlyingDecl(); 375 auto *EUnderlying = Existing->getUnderlyingDecl(); 376 377 // If they have different underlying declarations, prefer a typedef over the 378 // original type (this happens when two type declarations denote the same 379 // type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef 380 // might carry additional semantic information, such as an alignment override. 381 // However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag 382 // declaration over a typedef. Also prefer a tag over a typedef for 383 // destructor name lookup because in some contexts we only accept a 384 // class-name in a destructor declaration. 385 if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) { 386 assert(isa<TypeDecl>(DUnderlying) && isa<TypeDecl>(EUnderlying)); 387 bool HaveTag = isa<TagDecl>(EUnderlying); 388 bool WantTag = 389 Kind == Sema::LookupTagName || Kind == Sema::LookupDestructorName; 390 return HaveTag != WantTag; 391 } 392 393 // Pick the function with more default arguments. 394 // FIXME: In the presence of ambiguous default arguments, we should keep both, 395 // so we can diagnose the ambiguity if the default argument is needed. 396 // See C++ [over.match.best]p3. 397 if (auto *DFD = dyn_cast<FunctionDecl>(DUnderlying)) { 398 auto *EFD = cast<FunctionDecl>(EUnderlying); 399 unsigned DMin = DFD->getMinRequiredArguments(); 400 unsigned EMin = EFD->getMinRequiredArguments(); 401 // If D has more default arguments, it is preferred. 402 if (DMin != EMin) 403 return DMin < EMin; 404 // FIXME: When we track visibility for default function arguments, check 405 // that we pick the declaration with more visible default arguments. 406 } 407 408 // Pick the template with more default template arguments. 409 if (auto *DTD = dyn_cast<TemplateDecl>(DUnderlying)) { 410 auto *ETD = cast<TemplateDecl>(EUnderlying); 411 unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments(); 412 unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments(); 413 // If D has more default arguments, it is preferred. Note that default 414 // arguments (and their visibility) is monotonically increasing across the 415 // redeclaration chain, so this is a quick proxy for "is more recent". 416 if (DMin != EMin) 417 return DMin < EMin; 418 // If D has more *visible* default arguments, it is preferred. Note, an 419 // earlier default argument being visible does not imply that a later 420 // default argument is visible, so we can't just check the first one. 421 for (unsigned I = DMin, N = DTD->getTemplateParameters()->size(); 422 I != N; ++I) { 423 if (!S.hasVisibleDefaultArgument( 424 ETD->getTemplateParameters()->getParam(I)) && 425 S.hasVisibleDefaultArgument( 426 DTD->getTemplateParameters()->getParam(I))) 427 return true; 428 } 429 } 430 431 // VarDecl can have incomplete array types, prefer the one with more complete 432 // array type. 433 if (VarDecl *DVD = dyn_cast<VarDecl>(DUnderlying)) { 434 VarDecl *EVD = cast<VarDecl>(EUnderlying); 435 if (EVD->getType()->isIncompleteType() && 436 !DVD->getType()->isIncompleteType()) { 437 // Prefer the decl with a more complete type if visible. 438 return S.isVisible(DVD); 439 } 440 return false; // Avoid picking up a newer decl, just because it was newer. 441 } 442 443 // For most kinds of declaration, it doesn't really matter which one we pick. 444 if (!isa<FunctionDecl>(DUnderlying) && !isa<VarDecl>(DUnderlying)) { 445 // If the existing declaration is hidden, prefer the new one. Otherwise, 446 // keep what we've got. 447 return !S.isVisible(Existing); 448 } 449 450 // Pick the newer declaration; it might have a more precise type. 451 for (Decl *Prev = DUnderlying->getPreviousDecl(); Prev; 452 Prev = Prev->getPreviousDecl()) 453 if (Prev == EUnderlying) 454 return true; 455 return false; 456 } 457 458 /// Determine whether \p D can hide a tag declaration. 459 static bool canHideTag(NamedDecl *D) { 460 // C++ [basic.scope.declarative]p4: 461 // Given a set of declarations in a single declarative region [...] 462 // exactly one declaration shall declare a class name or enumeration name 463 // that is not a typedef name and the other declarations shall all refer to 464 // the same variable, non-static data member, or enumerator, or all refer 465 // to functions and function templates; in this case the class name or 466 // enumeration name is hidden. 467 // C++ [basic.scope.hiding]p2: 468 // A class name or enumeration name can be hidden by the name of a 469 // variable, data member, function, or enumerator declared in the same 470 // scope. 471 // An UnresolvedUsingValueDecl always instantiates to one of these. 472 D = D->getUnderlyingDecl(); 473 return isa<VarDecl>(D) || isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D) || 474 isa<FunctionTemplateDecl>(D) || isa<FieldDecl>(D) || 475 isa<UnresolvedUsingValueDecl>(D); 476 } 477 478 /// Resolves the result kind of this lookup. 479 void LookupResult::resolveKind() { 480 unsigned N = Decls.size(); 481 482 // Fast case: no possible ambiguity. 483 if (N == 0) { 484 assert(ResultKind == NotFound || 485 ResultKind == NotFoundInCurrentInstantiation); 486 return; 487 } 488 489 // If there's a single decl, we need to examine it to decide what 490 // kind of lookup this is. 491 if (N == 1) { 492 NamedDecl *D = (*Decls.begin())->getUnderlyingDecl(); 493 if (isa<FunctionTemplateDecl>(D)) 494 ResultKind = FoundOverloaded; 495 else if (isa<UnresolvedUsingValueDecl>(D)) 496 ResultKind = FoundUnresolvedValue; 497 return; 498 } 499 500 // Don't do any extra resolution if we've already resolved as ambiguous. 501 if (ResultKind == Ambiguous) return; 502 503 llvm::SmallDenseMap<NamedDecl*, unsigned, 16> Unique; 504 llvm::SmallDenseMap<QualType, unsigned, 16> UniqueTypes; 505 506 bool Ambiguous = false; 507 bool HasTag = false, HasFunction = false; 508 bool HasFunctionTemplate = false, HasUnresolved = false; 509 NamedDecl *HasNonFunction = nullptr; 510 511 llvm::SmallVector<NamedDecl*, 4> EquivalentNonFunctions; 512 513 unsigned UniqueTagIndex = 0; 514 515 unsigned I = 0; 516 while (I < N) { 517 NamedDecl *D = Decls[I]->getUnderlyingDecl(); 518 D = cast<NamedDecl>(D->getCanonicalDecl()); 519 520 // Ignore an invalid declaration unless it's the only one left. 521 if (D->isInvalidDecl() && !(I == 0 && N == 1)) { 522 Decls[I] = Decls[--N]; 523 continue; 524 } 525 526 llvm::Optional<unsigned> ExistingI; 527 528 // Redeclarations of types via typedef can occur both within a scope 529 // and, through using declarations and directives, across scopes. There is 530 // no ambiguity if they all refer to the same type, so unique based on the 531 // canonical type. 532 if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) { 533 QualType T = getSema().Context.getTypeDeclType(TD); 534 auto UniqueResult = UniqueTypes.insert( 535 std::make_pair(getSema().Context.getCanonicalType(T), I)); 536 if (!UniqueResult.second) { 537 // The type is not unique. 538 ExistingI = UniqueResult.first->second; 539 } 540 } 541 542 // For non-type declarations, check for a prior lookup result naming this 543 // canonical declaration. 544 if (!ExistingI) { 545 auto UniqueResult = Unique.insert(std::make_pair(D, I)); 546 if (!UniqueResult.second) { 547 // We've seen this entity before. 548 ExistingI = UniqueResult.first->second; 549 } 550 } 551 552 if (ExistingI) { 553 // This is not a unique lookup result. Pick one of the results and 554 // discard the other. 555 if (isPreferredLookupResult(getSema(), getLookupKind(), Decls[I], 556 Decls[*ExistingI])) 557 Decls[*ExistingI] = Decls[I]; 558 Decls[I] = Decls[--N]; 559 continue; 560 } 561 562 // Otherwise, do some decl type analysis and then continue. 563 564 if (isa<UnresolvedUsingValueDecl>(D)) { 565 HasUnresolved = true; 566 } else if (isa<TagDecl>(D)) { 567 if (HasTag) 568 Ambiguous = true; 569 UniqueTagIndex = I; 570 HasTag = true; 571 } else if (isa<FunctionTemplateDecl>(D)) { 572 HasFunction = true; 573 HasFunctionTemplate = true; 574 } else if (isa<FunctionDecl>(D)) { 575 HasFunction = true; 576 } else { 577 if (HasNonFunction) { 578 // If we're about to create an ambiguity between two declarations that 579 // are equivalent, but one is an internal linkage declaration from one 580 // module and the other is an internal linkage declaration from another 581 // module, just skip it. 582 if (getSema().isEquivalentInternalLinkageDeclaration(HasNonFunction, 583 D)) { 584 EquivalentNonFunctions.push_back(D); 585 Decls[I] = Decls[--N]; 586 continue; 587 } 588 589 Ambiguous = true; 590 } 591 HasNonFunction = D; 592 } 593 I++; 594 } 595 596 // C++ [basic.scope.hiding]p2: 597 // A class name or enumeration name can be hidden by the name of 598 // an object, function, or enumerator declared in the same 599 // scope. If a class or enumeration name and an object, function, 600 // or enumerator are declared in the same scope (in any order) 601 // with the same name, the class or enumeration name is hidden 602 // wherever the object, function, or enumerator name is visible. 603 // But it's still an error if there are distinct tag types found, 604 // even if they're not visible. (ref?) 605 if (N > 1 && HideTags && HasTag && !Ambiguous && 606 (HasFunction || HasNonFunction || HasUnresolved)) { 607 NamedDecl *OtherDecl = Decls[UniqueTagIndex ? 0 : N - 1]; 608 if (isa<TagDecl>(Decls[UniqueTagIndex]->getUnderlyingDecl()) && 609 getContextForScopeMatching(Decls[UniqueTagIndex])->Equals( 610 getContextForScopeMatching(OtherDecl)) && 611 canHideTag(OtherDecl)) 612 Decls[UniqueTagIndex] = Decls[--N]; 613 else 614 Ambiguous = true; 615 } 616 617 // FIXME: This diagnostic should really be delayed until we're done with 618 // the lookup result, in case the ambiguity is resolved by the caller. 619 if (!EquivalentNonFunctions.empty() && !Ambiguous) 620 getSema().diagnoseEquivalentInternalLinkageDeclarations( 621 getNameLoc(), HasNonFunction, EquivalentNonFunctions); 622 623 Decls.truncate(N); 624 625 if (HasNonFunction && (HasFunction || HasUnresolved)) 626 Ambiguous = true; 627 628 if (Ambiguous) 629 setAmbiguous(LookupResult::AmbiguousReference); 630 else if (HasUnresolved) 631 ResultKind = LookupResult::FoundUnresolvedValue; 632 else if (N > 1 || HasFunctionTemplate) 633 ResultKind = LookupResult::FoundOverloaded; 634 else 635 ResultKind = LookupResult::Found; 636 } 637 638 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) { 639 CXXBasePaths::const_paths_iterator I, E; 640 for (I = P.begin(), E = P.end(); I != E; ++I) 641 for (DeclContext::lookup_iterator DI = I->Decls, DE = DI.end(); DI != DE; 642 ++DI) 643 addDecl(*DI); 644 } 645 646 void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) { 647 Paths = new CXXBasePaths; 648 Paths->swap(P); 649 addDeclsFromBasePaths(*Paths); 650 resolveKind(); 651 setAmbiguous(AmbiguousBaseSubobjects); 652 } 653 654 void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) { 655 Paths = new CXXBasePaths; 656 Paths->swap(P); 657 addDeclsFromBasePaths(*Paths); 658 resolveKind(); 659 setAmbiguous(AmbiguousBaseSubobjectTypes); 660 } 661 662 void LookupResult::print(raw_ostream &Out) { 663 Out << Decls.size() << " result(s)"; 664 if (isAmbiguous()) Out << ", ambiguous"; 665 if (Paths) Out << ", base paths present"; 666 667 for (iterator I = begin(), E = end(); I != E; ++I) { 668 Out << "\n"; 669 (*I)->print(Out, 2); 670 } 671 } 672 673 LLVM_DUMP_METHOD void LookupResult::dump() { 674 llvm::errs() << "lookup results for " << getLookupName().getAsString() 675 << ":\n"; 676 for (NamedDecl *D : *this) 677 D->dump(); 678 } 679 680 /// Diagnose a missing builtin type. 681 static QualType diagOpenCLBuiltinTypeError(Sema &S, llvm::StringRef TypeClass, 682 llvm::StringRef Name) { 683 S.Diag(SourceLocation(), diag::err_opencl_type_not_found) 684 << TypeClass << Name; 685 return S.Context.VoidTy; 686 } 687 688 /// Lookup an OpenCL enum type. 689 static QualType getOpenCLEnumType(Sema &S, llvm::StringRef Name) { 690 LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(), 691 Sema::LookupTagName); 692 S.LookupName(Result, S.TUScope); 693 if (Result.empty()) 694 return diagOpenCLBuiltinTypeError(S, "enum", Name); 695 EnumDecl *Decl = Result.getAsSingle<EnumDecl>(); 696 if (!Decl) 697 return diagOpenCLBuiltinTypeError(S, "enum", Name); 698 return S.Context.getEnumType(Decl); 699 } 700 701 /// Lookup an OpenCL typedef type. 702 static QualType getOpenCLTypedefType(Sema &S, llvm::StringRef Name) { 703 LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(), 704 Sema::LookupOrdinaryName); 705 S.LookupName(Result, S.TUScope); 706 if (Result.empty()) 707 return diagOpenCLBuiltinTypeError(S, "typedef", Name); 708 TypedefNameDecl *Decl = Result.getAsSingle<TypedefNameDecl>(); 709 if (!Decl) 710 return diagOpenCLBuiltinTypeError(S, "typedef", Name); 711 return S.Context.getTypedefType(Decl); 712 } 713 714 /// Get the QualType instances of the return type and arguments for an OpenCL 715 /// builtin function signature. 716 /// \param S (in) The Sema instance. 717 /// \param OpenCLBuiltin (in) The signature currently handled. 718 /// \param GenTypeMaxCnt (out) Maximum number of types contained in a generic 719 /// type used as return type or as argument. 720 /// Only meaningful for generic types, otherwise equals 1. 721 /// \param RetTypes (out) List of the possible return types. 722 /// \param ArgTypes (out) List of the possible argument types. For each 723 /// argument, ArgTypes contains QualTypes for the Cartesian product 724 /// of (vector sizes) x (types) . 725 static void GetQualTypesForOpenCLBuiltin( 726 Sema &S, const OpenCLBuiltinStruct &OpenCLBuiltin, unsigned &GenTypeMaxCnt, 727 SmallVector<QualType, 1> &RetTypes, 728 SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) { 729 // Get the QualType instances of the return types. 730 unsigned Sig = SignatureTable[OpenCLBuiltin.SigTableIndex]; 731 OCL2Qual(S, TypeTable[Sig], RetTypes); 732 GenTypeMaxCnt = RetTypes.size(); 733 734 // Get the QualType instances of the arguments. 735 // First type is the return type, skip it. 736 for (unsigned Index = 1; Index < OpenCLBuiltin.NumTypes; Index++) { 737 SmallVector<QualType, 1> Ty; 738 OCL2Qual(S, TypeTable[SignatureTable[OpenCLBuiltin.SigTableIndex + Index]], 739 Ty); 740 GenTypeMaxCnt = (Ty.size() > GenTypeMaxCnt) ? Ty.size() : GenTypeMaxCnt; 741 ArgTypes.push_back(std::move(Ty)); 742 } 743 } 744 745 /// Create a list of the candidate function overloads for an OpenCL builtin 746 /// function. 747 /// \param Context (in) The ASTContext instance. 748 /// \param GenTypeMaxCnt (in) Maximum number of types contained in a generic 749 /// type used as return type or as argument. 750 /// Only meaningful for generic types, otherwise equals 1. 751 /// \param FunctionList (out) List of FunctionTypes. 752 /// \param RetTypes (in) List of the possible return types. 753 /// \param ArgTypes (in) List of the possible types for the arguments. 754 static void GetOpenCLBuiltinFctOverloads( 755 ASTContext &Context, unsigned GenTypeMaxCnt, 756 std::vector<QualType> &FunctionList, SmallVector<QualType, 1> &RetTypes, 757 SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) { 758 FunctionProtoType::ExtProtoInfo PI( 759 Context.getDefaultCallingConvention(false, false, true)); 760 PI.Variadic = false; 761 762 // Do not attempt to create any FunctionTypes if there are no return types, 763 // which happens when a type belongs to a disabled extension. 764 if (RetTypes.size() == 0) 765 return; 766 767 // Create FunctionTypes for each (gen)type. 768 for (unsigned IGenType = 0; IGenType < GenTypeMaxCnt; IGenType++) { 769 SmallVector<QualType, 5> ArgList; 770 771 for (unsigned A = 0; A < ArgTypes.size(); A++) { 772 // Bail out if there is an argument that has no available types. 773 if (ArgTypes[A].size() == 0) 774 return; 775 776 // Builtins such as "max" have an "sgentype" argument that represents 777 // the corresponding scalar type of a gentype. The number of gentypes 778 // must be a multiple of the number of sgentypes. 779 assert(GenTypeMaxCnt % ArgTypes[A].size() == 0 && 780 "argument type count not compatible with gentype type count"); 781 unsigned Idx = IGenType % ArgTypes[A].size(); 782 ArgList.push_back(ArgTypes[A][Idx]); 783 } 784 785 FunctionList.push_back(Context.getFunctionType( 786 RetTypes[(RetTypes.size() != 1) ? IGenType : 0], ArgList, PI)); 787 } 788 } 789 790 /// When trying to resolve a function name, if isOpenCLBuiltin() returns a 791 /// non-null <Index, Len> pair, then the name is referencing an OpenCL 792 /// builtin function. Add all candidate signatures to the LookUpResult. 793 /// 794 /// \param S (in) The Sema instance. 795 /// \param LR (inout) The LookupResult instance. 796 /// \param II (in) The identifier being resolved. 797 /// \param FctIndex (in) Starting index in the BuiltinTable. 798 /// \param Len (in) The signature list has Len elements. 799 static void InsertOCLBuiltinDeclarationsFromTable(Sema &S, LookupResult &LR, 800 IdentifierInfo *II, 801 const unsigned FctIndex, 802 const unsigned Len) { 803 // The builtin function declaration uses generic types (gentype). 804 bool HasGenType = false; 805 806 // Maximum number of types contained in a generic type used as return type or 807 // as argument. Only meaningful for generic types, otherwise equals 1. 808 unsigned GenTypeMaxCnt; 809 810 ASTContext &Context = S.Context; 811 812 for (unsigned SignatureIndex = 0; SignatureIndex < Len; SignatureIndex++) { 813 const OpenCLBuiltinStruct &OpenCLBuiltin = 814 BuiltinTable[FctIndex + SignatureIndex]; 815 816 // Ignore this builtin function if it is not available in the currently 817 // selected language version. 818 if (!isOpenCLVersionContainedInMask(Context.getLangOpts(), 819 OpenCLBuiltin.Versions)) 820 continue; 821 822 // Ignore this builtin function if it carries an extension macro that is 823 // not defined. This indicates that the extension is not supported by the 824 // target, so the builtin function should not be available. 825 StringRef Extensions = FunctionExtensionTable[OpenCLBuiltin.Extension]; 826 if (!Extensions.empty()) { 827 SmallVector<StringRef, 2> ExtVec; 828 Extensions.split(ExtVec, " "); 829 bool AllExtensionsDefined = true; 830 for (StringRef Ext : ExtVec) { 831 if (!S.getPreprocessor().isMacroDefined(Ext)) { 832 AllExtensionsDefined = false; 833 break; 834 } 835 } 836 if (!AllExtensionsDefined) 837 continue; 838 } 839 840 SmallVector<QualType, 1> RetTypes; 841 SmallVector<SmallVector<QualType, 1>, 5> ArgTypes; 842 843 // Obtain QualType lists for the function signature. 844 GetQualTypesForOpenCLBuiltin(S, OpenCLBuiltin, GenTypeMaxCnt, RetTypes, 845 ArgTypes); 846 if (GenTypeMaxCnt > 1) { 847 HasGenType = true; 848 } 849 850 // Create function overload for each type combination. 851 std::vector<QualType> FunctionList; 852 GetOpenCLBuiltinFctOverloads(Context, GenTypeMaxCnt, FunctionList, RetTypes, 853 ArgTypes); 854 855 SourceLocation Loc = LR.getNameLoc(); 856 DeclContext *Parent = Context.getTranslationUnitDecl(); 857 FunctionDecl *NewOpenCLBuiltin; 858 859 for (const auto &FTy : FunctionList) { 860 NewOpenCLBuiltin = FunctionDecl::Create( 861 Context, Parent, Loc, Loc, II, FTy, /*TInfo=*/nullptr, SC_Extern, 862 S.getCurFPFeatures().isFPConstrained(), false, 863 FTy->isFunctionProtoType()); 864 NewOpenCLBuiltin->setImplicit(); 865 866 // Create Decl objects for each parameter, adding them to the 867 // FunctionDecl. 868 const auto *FP = cast<FunctionProtoType>(FTy); 869 SmallVector<ParmVarDecl *, 4> ParmList; 870 for (unsigned IParm = 0, e = FP->getNumParams(); IParm != e; ++IParm) { 871 ParmVarDecl *Parm = ParmVarDecl::Create( 872 Context, NewOpenCLBuiltin, SourceLocation(), SourceLocation(), 873 nullptr, FP->getParamType(IParm), nullptr, SC_None, nullptr); 874 Parm->setScopeInfo(0, IParm); 875 ParmList.push_back(Parm); 876 } 877 NewOpenCLBuiltin->setParams(ParmList); 878 879 // Add function attributes. 880 if (OpenCLBuiltin.IsPure) 881 NewOpenCLBuiltin->addAttr(PureAttr::CreateImplicit(Context)); 882 if (OpenCLBuiltin.IsConst) 883 NewOpenCLBuiltin->addAttr(ConstAttr::CreateImplicit(Context)); 884 if (OpenCLBuiltin.IsConv) 885 NewOpenCLBuiltin->addAttr(ConvergentAttr::CreateImplicit(Context)); 886 887 if (!S.getLangOpts().OpenCLCPlusPlus) 888 NewOpenCLBuiltin->addAttr(OverloadableAttr::CreateImplicit(Context)); 889 890 LR.addDecl(NewOpenCLBuiltin); 891 } 892 } 893 894 // If we added overloads, need to resolve the lookup result. 895 if (Len > 1 || HasGenType) 896 LR.resolveKind(); 897 } 898 899 /// Lookup a builtin function, when name lookup would otherwise 900 /// fail. 901 bool Sema::LookupBuiltin(LookupResult &R) { 902 Sema::LookupNameKind NameKind = R.getLookupKind(); 903 904 // If we didn't find a use of this identifier, and if the identifier 905 // corresponds to a compiler builtin, create the decl object for the builtin 906 // now, injecting it into translation unit scope, and return it. 907 if (NameKind == Sema::LookupOrdinaryName || 908 NameKind == Sema::LookupRedeclarationWithLinkage) { 909 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo(); 910 if (II) { 911 if (getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName) { 912 if (II == getASTContext().getMakeIntegerSeqName()) { 913 R.addDecl(getASTContext().getMakeIntegerSeqDecl()); 914 return true; 915 } else if (II == getASTContext().getTypePackElementName()) { 916 R.addDecl(getASTContext().getTypePackElementDecl()); 917 return true; 918 } 919 } 920 921 // Check if this is an OpenCL Builtin, and if so, insert its overloads. 922 if (getLangOpts().OpenCL && getLangOpts().DeclareOpenCLBuiltins) { 923 auto Index = isOpenCLBuiltin(II->getName()); 924 if (Index.first) { 925 InsertOCLBuiltinDeclarationsFromTable(*this, R, II, Index.first - 1, 926 Index.second); 927 return true; 928 } 929 } 930 931 // If this is a builtin on this (or all) targets, create the decl. 932 if (unsigned BuiltinID = II->getBuiltinID()) { 933 // In C++, C2x, and OpenCL (spec v1.2 s6.9.f), we don't have any 934 // predefined library functions like 'malloc'. Instead, we'll just 935 // error. 936 if ((getLangOpts().CPlusPlus || getLangOpts().OpenCL || 937 getLangOpts().C2x) && 938 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 939 return false; 940 941 if (NamedDecl *D = 942 LazilyCreateBuiltin(II, BuiltinID, TUScope, 943 R.isForRedeclaration(), R.getNameLoc())) { 944 R.addDecl(D); 945 return true; 946 } 947 } 948 } 949 } 950 951 return false; 952 } 953 954 /// Looks up the declaration of "struct objc_super" and 955 /// saves it for later use in building builtin declaration of 956 /// objc_msgSendSuper and objc_msgSendSuper_stret. 957 static void LookupPredefedObjCSuperType(Sema &Sema, Scope *S) { 958 ASTContext &Context = Sema.Context; 959 LookupResult Result(Sema, &Context.Idents.get("objc_super"), SourceLocation(), 960 Sema::LookupTagName); 961 Sema.LookupName(Result, S); 962 if (Result.getResultKind() == LookupResult::Found) 963 if (const TagDecl *TD = Result.getAsSingle<TagDecl>()) 964 Context.setObjCSuperType(Context.getTagDeclType(TD)); 965 } 966 967 void Sema::LookupNecessaryTypesForBuiltin(Scope *S, unsigned ID) { 968 if (ID == Builtin::BIobjc_msgSendSuper) 969 LookupPredefedObjCSuperType(*this, S); 970 } 971 972 /// Determine whether we can declare a special member function within 973 /// the class at this point. 974 static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) { 975 // We need to have a definition for the class. 976 if (!Class->getDefinition() || Class->isDependentContext()) 977 return false; 978 979 // We can't be in the middle of defining the class. 980 return !Class->isBeingDefined(); 981 } 982 983 void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) { 984 if (!CanDeclareSpecialMemberFunction(Class)) 985 return; 986 987 // If the default constructor has not yet been declared, do so now. 988 if (Class->needsImplicitDefaultConstructor()) 989 DeclareImplicitDefaultConstructor(Class); 990 991 // If the copy constructor has not yet been declared, do so now. 992 if (Class->needsImplicitCopyConstructor()) 993 DeclareImplicitCopyConstructor(Class); 994 995 // If the copy assignment operator has not yet been declared, do so now. 996 if (Class->needsImplicitCopyAssignment()) 997 DeclareImplicitCopyAssignment(Class); 998 999 if (getLangOpts().CPlusPlus11) { 1000 // If the move constructor has not yet been declared, do so now. 1001 if (Class->needsImplicitMoveConstructor()) 1002 DeclareImplicitMoveConstructor(Class); 1003 1004 // If the move assignment operator has not yet been declared, do so now. 1005 if (Class->needsImplicitMoveAssignment()) 1006 DeclareImplicitMoveAssignment(Class); 1007 } 1008 1009 // If the destructor has not yet been declared, do so now. 1010 if (Class->needsImplicitDestructor()) 1011 DeclareImplicitDestructor(Class); 1012 } 1013 1014 /// Determine whether this is the name of an implicitly-declared 1015 /// special member function. 1016 static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) { 1017 switch (Name.getNameKind()) { 1018 case DeclarationName::CXXConstructorName: 1019 case DeclarationName::CXXDestructorName: 1020 return true; 1021 1022 case DeclarationName::CXXOperatorName: 1023 return Name.getCXXOverloadedOperator() == OO_Equal; 1024 1025 default: 1026 break; 1027 } 1028 1029 return false; 1030 } 1031 1032 /// If there are any implicit member functions with the given name 1033 /// that need to be declared in the given declaration context, do so. 1034 static void DeclareImplicitMemberFunctionsWithName(Sema &S, 1035 DeclarationName Name, 1036 SourceLocation Loc, 1037 const DeclContext *DC) { 1038 if (!DC) 1039 return; 1040 1041 switch (Name.getNameKind()) { 1042 case DeclarationName::CXXConstructorName: 1043 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) 1044 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) { 1045 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record); 1046 if (Record->needsImplicitDefaultConstructor()) 1047 S.DeclareImplicitDefaultConstructor(Class); 1048 if (Record->needsImplicitCopyConstructor()) 1049 S.DeclareImplicitCopyConstructor(Class); 1050 if (S.getLangOpts().CPlusPlus11 && 1051 Record->needsImplicitMoveConstructor()) 1052 S.DeclareImplicitMoveConstructor(Class); 1053 } 1054 break; 1055 1056 case DeclarationName::CXXDestructorName: 1057 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) 1058 if (Record->getDefinition() && Record->needsImplicitDestructor() && 1059 CanDeclareSpecialMemberFunction(Record)) 1060 S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record)); 1061 break; 1062 1063 case DeclarationName::CXXOperatorName: 1064 if (Name.getCXXOverloadedOperator() != OO_Equal) 1065 break; 1066 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->needsImplicitCopyAssignment()) 1071 S.DeclareImplicitCopyAssignment(Class); 1072 if (S.getLangOpts().CPlusPlus11 && 1073 Record->needsImplicitMoveAssignment()) 1074 S.DeclareImplicitMoveAssignment(Class); 1075 } 1076 } 1077 break; 1078 1079 case DeclarationName::CXXDeductionGuideName: 1080 S.DeclareImplicitDeductionGuides(Name.getCXXDeductionGuideTemplate(), Loc); 1081 break; 1082 1083 default: 1084 break; 1085 } 1086 } 1087 1088 // Adds all qualifying matches for a name within a decl context to the 1089 // given lookup result. Returns true if any matches were found. 1090 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) { 1091 bool Found = false; 1092 1093 // Lazily declare C++ special member functions. 1094 if (S.getLangOpts().CPlusPlus) 1095 DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), R.getNameLoc(), 1096 DC); 1097 1098 // Perform lookup into this declaration context. 1099 DeclContext::lookup_result DR = DC->lookup(R.getLookupName()); 1100 for (NamedDecl *D : DR) { 1101 if ((D = R.getAcceptableDecl(D))) { 1102 R.addDecl(D); 1103 Found = true; 1104 } 1105 } 1106 1107 if (!Found && DC->isTranslationUnit() && S.LookupBuiltin(R)) 1108 return true; 1109 1110 if (R.getLookupName().getNameKind() 1111 != DeclarationName::CXXConversionFunctionName || 1112 R.getLookupName().getCXXNameType()->isDependentType() || 1113 !isa<CXXRecordDecl>(DC)) 1114 return Found; 1115 1116 // C++ [temp.mem]p6: 1117 // A specialization of a conversion function template is not found by 1118 // name lookup. Instead, any conversion function templates visible in the 1119 // context of the use are considered. [...] 1120 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC); 1121 if (!Record->isCompleteDefinition()) 1122 return Found; 1123 1124 // For conversion operators, 'operator auto' should only match 1125 // 'operator auto'. Since 'auto' is not a type, it shouldn't be considered 1126 // as a candidate for template substitution. 1127 auto *ContainedDeducedType = 1128 R.getLookupName().getCXXNameType()->getContainedDeducedType(); 1129 if (R.getLookupName().getNameKind() == 1130 DeclarationName::CXXConversionFunctionName && 1131 ContainedDeducedType && ContainedDeducedType->isUndeducedType()) 1132 return Found; 1133 1134 for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(), 1135 UEnd = Record->conversion_end(); U != UEnd; ++U) { 1136 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U); 1137 if (!ConvTemplate) 1138 continue; 1139 1140 // When we're performing lookup for the purposes of redeclaration, just 1141 // add the conversion function template. When we deduce template 1142 // arguments for specializations, we'll end up unifying the return 1143 // type of the new declaration with the type of the function template. 1144 if (R.isForRedeclaration()) { 1145 R.addDecl(ConvTemplate); 1146 Found = true; 1147 continue; 1148 } 1149 1150 // C++ [temp.mem]p6: 1151 // [...] For each such operator, if argument deduction succeeds 1152 // (14.9.2.3), the resulting specialization is used as if found by 1153 // name lookup. 1154 // 1155 // When referencing a conversion function for any purpose other than 1156 // a redeclaration (such that we'll be building an expression with the 1157 // result), perform template argument deduction and place the 1158 // specialization into the result set. We do this to avoid forcing all 1159 // callers to perform special deduction for conversion functions. 1160 TemplateDeductionInfo Info(R.getNameLoc()); 1161 FunctionDecl *Specialization = nullptr; 1162 1163 const FunctionProtoType *ConvProto 1164 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>(); 1165 assert(ConvProto && "Nonsensical conversion function template type"); 1166 1167 // Compute the type of the function that we would expect the conversion 1168 // function to have, if it were to match the name given. 1169 // FIXME: Calling convention! 1170 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo(); 1171 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C); 1172 EPI.ExceptionSpec = EST_None; 1173 QualType ExpectedType 1174 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(), 1175 None, EPI); 1176 1177 // Perform template argument deduction against the type that we would 1178 // expect the function to have. 1179 if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType, 1180 Specialization, Info) 1181 == Sema::TDK_Success) { 1182 R.addDecl(Specialization); 1183 Found = true; 1184 } 1185 } 1186 1187 return Found; 1188 } 1189 1190 // Performs C++ unqualified lookup into the given file context. 1191 static bool 1192 CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context, 1193 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) { 1194 1195 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!"); 1196 1197 // Perform direct name lookup into the LookupCtx. 1198 bool Found = LookupDirect(S, R, NS); 1199 1200 // Perform direct name lookup into the namespaces nominated by the 1201 // using directives whose common ancestor is this namespace. 1202 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS)) 1203 if (LookupDirect(S, R, UUE.getNominatedNamespace())) 1204 Found = true; 1205 1206 R.resolveKind(); 1207 1208 return Found; 1209 } 1210 1211 static bool isNamespaceOrTranslationUnitScope(Scope *S) { 1212 if (DeclContext *Ctx = S->getEntity()) 1213 return Ctx->isFileContext(); 1214 return false; 1215 } 1216 1217 /// Find the outer declaration context from this scope. This indicates the 1218 /// context that we should search up to (exclusive) before considering the 1219 /// parent of the specified scope. 1220 static DeclContext *findOuterContext(Scope *S) { 1221 for (Scope *OuterS = S->getParent(); OuterS; OuterS = OuterS->getParent()) 1222 if (DeclContext *DC = OuterS->getLookupEntity()) 1223 return DC; 1224 return nullptr; 1225 } 1226 1227 namespace { 1228 /// An RAII object to specify that we want to find block scope extern 1229 /// declarations. 1230 struct FindLocalExternScope { 1231 FindLocalExternScope(LookupResult &R) 1232 : R(R), OldFindLocalExtern(R.getIdentifierNamespace() & 1233 Decl::IDNS_LocalExtern) { 1234 R.setFindLocalExtern(R.getIdentifierNamespace() & 1235 (Decl::IDNS_Ordinary | Decl::IDNS_NonMemberOperator)); 1236 } 1237 void restore() { 1238 R.setFindLocalExtern(OldFindLocalExtern); 1239 } 1240 ~FindLocalExternScope() { 1241 restore(); 1242 } 1243 LookupResult &R; 1244 bool OldFindLocalExtern; 1245 }; 1246 } // end anonymous namespace 1247 1248 bool Sema::CppLookupName(LookupResult &R, Scope *S) { 1249 assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup"); 1250 1251 DeclarationName Name = R.getLookupName(); 1252 Sema::LookupNameKind NameKind = R.getLookupKind(); 1253 1254 // If this is the name of an implicitly-declared special member function, 1255 // go through the scope stack to implicitly declare 1256 if (isImplicitlyDeclaredMemberFunctionName(Name)) { 1257 for (Scope *PreS = S; PreS; PreS = PreS->getParent()) 1258 if (DeclContext *DC = PreS->getEntity()) 1259 DeclareImplicitMemberFunctionsWithName(*this, Name, R.getNameLoc(), DC); 1260 } 1261 1262 // Implicitly declare member functions with the name we're looking for, if in 1263 // fact we are in a scope where it matters. 1264 1265 Scope *Initial = S; 1266 IdentifierResolver::iterator 1267 I = IdResolver.begin(Name), 1268 IEnd = IdResolver.end(); 1269 1270 // First we lookup local scope. 1271 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir] 1272 // ...During unqualified name lookup (3.4.1), the names appear as if 1273 // they were declared in the nearest enclosing namespace which contains 1274 // both the using-directive and the nominated namespace. 1275 // [Note: in this context, "contains" means "contains directly or 1276 // indirectly". 1277 // 1278 // For example: 1279 // namespace A { int i; } 1280 // void foo() { 1281 // int i; 1282 // { 1283 // using namespace A; 1284 // ++i; // finds local 'i', A::i appears at global scope 1285 // } 1286 // } 1287 // 1288 UnqualUsingDirectiveSet UDirs(*this); 1289 bool VisitedUsingDirectives = false; 1290 bool LeftStartingScope = false; 1291 1292 // When performing a scope lookup, we want to find local extern decls. 1293 FindLocalExternScope FindLocals(R); 1294 1295 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) { 1296 bool SearchNamespaceScope = true; 1297 // Check whether the IdResolver has anything in this scope. 1298 for (; I != IEnd && S->isDeclScope(*I); ++I) { 1299 if (NamedDecl *ND = R.getAcceptableDecl(*I)) { 1300 if (NameKind == LookupRedeclarationWithLinkage && 1301 !(*I)->isTemplateParameter()) { 1302 // If it's a template parameter, we still find it, so we can diagnose 1303 // the invalid redeclaration. 1304 1305 // Determine whether this (or a previous) declaration is 1306 // out-of-scope. 1307 if (!LeftStartingScope && !Initial->isDeclScope(*I)) 1308 LeftStartingScope = true; 1309 1310 // If we found something outside of our starting scope that 1311 // does not have linkage, skip it. 1312 if (LeftStartingScope && !((*I)->hasLinkage())) { 1313 R.setShadowed(); 1314 continue; 1315 } 1316 } else { 1317 // We found something in this scope, we should not look at the 1318 // namespace scope 1319 SearchNamespaceScope = false; 1320 } 1321 R.addDecl(ND); 1322 } 1323 } 1324 if (!SearchNamespaceScope) { 1325 R.resolveKind(); 1326 if (S->isClassScope()) 1327 if (CXXRecordDecl *Record = 1328 dyn_cast_or_null<CXXRecordDecl>(S->getEntity())) 1329 R.setNamingClass(Record); 1330 return true; 1331 } 1332 1333 if (NameKind == LookupLocalFriendName && !S->isClassScope()) { 1334 // C++11 [class.friend]p11: 1335 // If a friend declaration appears in a local class and the name 1336 // specified is an unqualified name, a prior declaration is 1337 // looked up without considering scopes that are outside the 1338 // innermost enclosing non-class scope. 1339 return false; 1340 } 1341 1342 if (DeclContext *Ctx = S->getLookupEntity()) { 1343 DeclContext *OuterCtx = findOuterContext(S); 1344 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 1345 // We do not directly look into transparent contexts, since 1346 // those entities will be found in the nearest enclosing 1347 // non-transparent context. 1348 if (Ctx->isTransparentContext()) 1349 continue; 1350 1351 // We do not look directly into function or method contexts, 1352 // since all of the local variables and parameters of the 1353 // function/method are present within the Scope. 1354 if (Ctx->isFunctionOrMethod()) { 1355 // If we have an Objective-C instance method, look for ivars 1356 // in the corresponding interface. 1357 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 1358 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo()) 1359 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) { 1360 ObjCInterfaceDecl *ClassDeclared; 1361 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable( 1362 Name.getAsIdentifierInfo(), 1363 ClassDeclared)) { 1364 if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) { 1365 R.addDecl(ND); 1366 R.resolveKind(); 1367 return true; 1368 } 1369 } 1370 } 1371 } 1372 1373 continue; 1374 } 1375 1376 // If this is a file context, we need to perform unqualified name 1377 // lookup considering using directives. 1378 if (Ctx->isFileContext()) { 1379 // If we haven't handled using directives yet, do so now. 1380 if (!VisitedUsingDirectives) { 1381 // Add using directives from this context up to the top level. 1382 for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) { 1383 if (UCtx->isTransparentContext()) 1384 continue; 1385 1386 UDirs.visit(UCtx, UCtx); 1387 } 1388 1389 // Find the innermost file scope, so we can add using directives 1390 // from local scopes. 1391 Scope *InnermostFileScope = S; 1392 while (InnermostFileScope && 1393 !isNamespaceOrTranslationUnitScope(InnermostFileScope)) 1394 InnermostFileScope = InnermostFileScope->getParent(); 1395 UDirs.visitScopeChain(Initial, InnermostFileScope); 1396 1397 UDirs.done(); 1398 1399 VisitedUsingDirectives = true; 1400 } 1401 1402 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) { 1403 R.resolveKind(); 1404 return true; 1405 } 1406 1407 continue; 1408 } 1409 1410 // Perform qualified name lookup into this context. 1411 // FIXME: In some cases, we know that every name that could be found by 1412 // this qualified name lookup will also be on the identifier chain. For 1413 // example, inside a class without any base classes, we never need to 1414 // perform qualified lookup because all of the members are on top of the 1415 // identifier chain. 1416 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true)) 1417 return true; 1418 } 1419 } 1420 } 1421 1422 // Stop if we ran out of scopes. 1423 // FIXME: This really, really shouldn't be happening. 1424 if (!S) return false; 1425 1426 // If we are looking for members, no need to look into global/namespace scope. 1427 if (NameKind == LookupMemberName) 1428 return false; 1429 1430 // Collect UsingDirectiveDecls in all scopes, and recursively all 1431 // nominated namespaces by those using-directives. 1432 // 1433 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we 1434 // don't build it for each lookup! 1435 if (!VisitedUsingDirectives) { 1436 UDirs.visitScopeChain(Initial, S); 1437 UDirs.done(); 1438 } 1439 1440 // If we're not performing redeclaration lookup, do not look for local 1441 // extern declarations outside of a function scope. 1442 if (!R.isForRedeclaration()) 1443 FindLocals.restore(); 1444 1445 // Lookup namespace scope, and global scope. 1446 // Unqualified name lookup in C++ requires looking into scopes 1447 // that aren't strictly lexical, and therefore we walk through the 1448 // context as well as walking through the scopes. 1449 for (; S; S = S->getParent()) { 1450 // Check whether the IdResolver has anything in this scope. 1451 bool Found = false; 1452 for (; I != IEnd && S->isDeclScope(*I); ++I) { 1453 if (NamedDecl *ND = R.getAcceptableDecl(*I)) { 1454 // We found something. Look for anything else in our scope 1455 // with this same name and in an acceptable identifier 1456 // namespace, so that we can construct an overload set if we 1457 // need to. 1458 Found = true; 1459 R.addDecl(ND); 1460 } 1461 } 1462 1463 if (Found && S->isTemplateParamScope()) { 1464 R.resolveKind(); 1465 return true; 1466 } 1467 1468 DeclContext *Ctx = S->getLookupEntity(); 1469 if (Ctx) { 1470 DeclContext *OuterCtx = findOuterContext(S); 1471 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 1472 // We do not directly look into transparent contexts, since 1473 // those entities will be found in the nearest enclosing 1474 // non-transparent context. 1475 if (Ctx->isTransparentContext()) 1476 continue; 1477 1478 // If we have a context, and it's not a context stashed in the 1479 // template parameter scope for an out-of-line definition, also 1480 // look into that context. 1481 if (!(Found && S->isTemplateParamScope())) { 1482 assert(Ctx->isFileContext() && 1483 "We should have been looking only at file context here already."); 1484 1485 // Look into context considering using-directives. 1486 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) 1487 Found = true; 1488 } 1489 1490 if (Found) { 1491 R.resolveKind(); 1492 return true; 1493 } 1494 1495 if (R.isForRedeclaration() && !Ctx->isTransparentContext()) 1496 return false; 1497 } 1498 } 1499 1500 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext()) 1501 return false; 1502 } 1503 1504 return !R.empty(); 1505 } 1506 1507 void Sema::makeMergedDefinitionVisible(NamedDecl *ND) { 1508 if (auto *M = getCurrentModule()) 1509 Context.mergeDefinitionIntoModule(ND, M); 1510 else 1511 // We're not building a module; just make the definition visible. 1512 ND->setVisibleDespiteOwningModule(); 1513 1514 // If ND is a template declaration, make the template parameters 1515 // visible too. They're not (necessarily) within a mergeable DeclContext. 1516 if (auto *TD = dyn_cast<TemplateDecl>(ND)) 1517 for (auto *Param : *TD->getTemplateParameters()) 1518 makeMergedDefinitionVisible(Param); 1519 } 1520 1521 /// Find the module in which the given declaration was defined. 1522 static Module *getDefiningModule(Sema &S, Decl *Entity) { 1523 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) { 1524 // If this function was instantiated from a template, the defining module is 1525 // the module containing the pattern. 1526 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern()) 1527 Entity = Pattern; 1528 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) { 1529 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern()) 1530 Entity = Pattern; 1531 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) { 1532 if (auto *Pattern = ED->getTemplateInstantiationPattern()) 1533 Entity = Pattern; 1534 } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) { 1535 if (VarDecl *Pattern = VD->getTemplateInstantiationPattern()) 1536 Entity = Pattern; 1537 } 1538 1539 // Walk up to the containing context. That might also have been instantiated 1540 // from a template. 1541 DeclContext *Context = Entity->getLexicalDeclContext(); 1542 if (Context->isFileContext()) 1543 return S.getOwningModule(Entity); 1544 return getDefiningModule(S, cast<Decl>(Context)); 1545 } 1546 1547 llvm::DenseSet<Module*> &Sema::getLookupModules() { 1548 unsigned N = CodeSynthesisContexts.size(); 1549 for (unsigned I = CodeSynthesisContextLookupModules.size(); 1550 I != N; ++I) { 1551 Module *M = CodeSynthesisContexts[I].Entity ? 1552 getDefiningModule(*this, CodeSynthesisContexts[I].Entity) : 1553 nullptr; 1554 if (M && !LookupModulesCache.insert(M).second) 1555 M = nullptr; 1556 CodeSynthesisContextLookupModules.push_back(M); 1557 } 1558 return LookupModulesCache; 1559 } 1560 1561 /// Determine if we could use all the declarations in the module. 1562 bool Sema::isUsableModule(const Module *M) { 1563 assert(M && "We shouldn't check nullness for module here"); 1564 // Return quickly if we cached the result. 1565 if (UsableModuleUnitsCache.count(M)) 1566 return true; 1567 1568 // If M is the global module fragment of the current translation unit. So it 1569 // should be usable. 1570 // [module.global.frag]p1: 1571 // The global module fragment can be used to provide declarations that are 1572 // attached to the global module and usable within the module unit. 1573 if (M == GlobalModuleFragment || 1574 // If M is the module we're parsing, it should be usable. This covers the 1575 // private module fragment. The private module fragment is usable only if 1576 // it is within the current module unit. And it must be the current 1577 // parsing module unit if it is within the current module unit according 1578 // to the grammar of the private module fragment. NOTE: This is covered by 1579 // the following condition. The intention of the check is to avoid string 1580 // comparison as much as possible. 1581 M == getCurrentModule() || 1582 // The module unit which is in the same module with the current module 1583 // unit is usable. 1584 // 1585 // FIXME: Here we judge if they are in the same module by comparing the 1586 // string. Is there any better solution? 1587 M->getPrimaryModuleInterfaceName() == 1588 llvm::StringRef(getLangOpts().CurrentModule).split(':').first) { 1589 UsableModuleUnitsCache.insert(M); 1590 return true; 1591 } 1592 1593 return false; 1594 } 1595 1596 bool Sema::hasVisibleMergedDefinition(NamedDecl *Def) { 1597 for (const Module *Merged : Context.getModulesWithMergedDefinition(Def)) 1598 if (isModuleVisible(Merged)) 1599 return true; 1600 return false; 1601 } 1602 1603 bool Sema::hasMergedDefinitionInCurrentModule(NamedDecl *Def) { 1604 for (const Module *Merged : Context.getModulesWithMergedDefinition(Def)) 1605 if (isUsableModule(Merged)) 1606 return true; 1607 return false; 1608 } 1609 1610 template <typename ParmDecl> 1611 static bool 1612 hasAcceptableDefaultArgument(Sema &S, const ParmDecl *D, 1613 llvm::SmallVectorImpl<Module *> *Modules, 1614 Sema::AcceptableKind Kind) { 1615 if (!D->hasDefaultArgument()) 1616 return false; 1617 1618 while (D) { 1619 auto &DefaultArg = D->getDefaultArgStorage(); 1620 if (!DefaultArg.isInherited() && S.isAcceptable(D, Kind)) 1621 return true; 1622 1623 if (!DefaultArg.isInherited() && Modules) { 1624 auto *NonConstD = const_cast<ParmDecl*>(D); 1625 Modules->push_back(S.getOwningModule(NonConstD)); 1626 } 1627 1628 // If there was a previous default argument, maybe its parameter is visible. 1629 D = DefaultArg.getInheritedFrom(); 1630 } 1631 return false; 1632 } 1633 1634 bool Sema::hasAcceptableDefaultArgument( 1635 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules, 1636 Sema::AcceptableKind Kind) { 1637 if (auto *P = dyn_cast<TemplateTypeParmDecl>(D)) 1638 return ::hasAcceptableDefaultArgument(*this, P, Modules, Kind); 1639 1640 if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D)) 1641 return ::hasAcceptableDefaultArgument(*this, P, Modules, Kind); 1642 1643 return ::hasAcceptableDefaultArgument( 1644 *this, cast<TemplateTemplateParmDecl>(D), Modules, Kind); 1645 } 1646 1647 bool Sema::hasVisibleDefaultArgument(const NamedDecl *D, 1648 llvm::SmallVectorImpl<Module *> *Modules) { 1649 return hasAcceptableDefaultArgument(D, Modules, 1650 Sema::AcceptableKind::Visible); 1651 } 1652 1653 bool Sema::hasReachableDefaultArgument( 1654 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1655 return hasAcceptableDefaultArgument(D, Modules, 1656 Sema::AcceptableKind::Reachable); 1657 } 1658 1659 template <typename Filter> 1660 static bool 1661 hasAcceptableDeclarationImpl(Sema &S, const NamedDecl *D, 1662 llvm::SmallVectorImpl<Module *> *Modules, Filter F, 1663 Sema::AcceptableKind Kind) { 1664 bool HasFilteredRedecls = false; 1665 1666 for (auto *Redecl : D->redecls()) { 1667 auto *R = cast<NamedDecl>(Redecl); 1668 if (!F(R)) 1669 continue; 1670 1671 if (S.isAcceptable(R, Kind)) 1672 return true; 1673 1674 HasFilteredRedecls = true; 1675 1676 if (Modules) 1677 Modules->push_back(R->getOwningModule()); 1678 } 1679 1680 // Only return false if there is at least one redecl that is not filtered out. 1681 if (HasFilteredRedecls) 1682 return false; 1683 1684 return true; 1685 } 1686 1687 static bool 1688 hasAcceptableExplicitSpecialization(Sema &S, const NamedDecl *D, 1689 llvm::SmallVectorImpl<Module *> *Modules, 1690 Sema::AcceptableKind Kind) { 1691 return hasAcceptableDeclarationImpl( 1692 S, D, Modules, 1693 [](const NamedDecl *D) { 1694 if (auto *RD = dyn_cast<CXXRecordDecl>(D)) 1695 return RD->getTemplateSpecializationKind() == 1696 TSK_ExplicitSpecialization; 1697 if (auto *FD = dyn_cast<FunctionDecl>(D)) 1698 return FD->getTemplateSpecializationKind() == 1699 TSK_ExplicitSpecialization; 1700 if (auto *VD = dyn_cast<VarDecl>(D)) 1701 return VD->getTemplateSpecializationKind() == 1702 TSK_ExplicitSpecialization; 1703 llvm_unreachable("unknown explicit specialization kind"); 1704 }, 1705 Kind); 1706 } 1707 1708 bool Sema::hasVisibleExplicitSpecialization( 1709 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1710 return ::hasAcceptableExplicitSpecialization(*this, D, Modules, 1711 Sema::AcceptableKind::Visible); 1712 } 1713 1714 bool Sema::hasReachableExplicitSpecialization( 1715 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1716 return ::hasAcceptableExplicitSpecialization(*this, D, Modules, 1717 Sema::AcceptableKind::Reachable); 1718 } 1719 1720 static bool 1721 hasAcceptableMemberSpecialization(Sema &S, const NamedDecl *D, 1722 llvm::SmallVectorImpl<Module *> *Modules, 1723 Sema::AcceptableKind Kind) { 1724 assert(isa<CXXRecordDecl>(D->getDeclContext()) && 1725 "not a member specialization"); 1726 return hasAcceptableDeclarationImpl( 1727 S, D, Modules, 1728 [](const NamedDecl *D) { 1729 // If the specialization is declared at namespace scope, then it's a 1730 // member specialization declaration. If it's lexically inside the class 1731 // definition then it was instantiated. 1732 // 1733 // FIXME: This is a hack. There should be a better way to determine 1734 // this. 1735 // FIXME: What about MS-style explicit specializations declared within a 1736 // class definition? 1737 return D->getLexicalDeclContext()->isFileContext(); 1738 }, 1739 Kind); 1740 } 1741 1742 bool Sema::hasVisibleMemberSpecialization( 1743 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1744 return hasAcceptableMemberSpecialization(*this, D, Modules, 1745 Sema::AcceptableKind::Visible); 1746 } 1747 1748 bool Sema::hasReachableMemberSpecialization( 1749 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1750 return hasAcceptableMemberSpecialization(*this, D, Modules, 1751 Sema::AcceptableKind::Reachable); 1752 } 1753 1754 /// Determine whether a declaration is acceptable to name lookup. 1755 /// 1756 /// This routine determines whether the declaration D is acceptable in the 1757 /// current lookup context, taking into account the current template 1758 /// instantiation stack. During template instantiation, a declaration is 1759 /// acceptable if it is acceptable from a module containing any entity on the 1760 /// template instantiation path (by instantiating a template, you allow it to 1761 /// see the declarations that your module can see, including those later on in 1762 /// your module). 1763 bool LookupResult::isAcceptableSlow(Sema &SemaRef, NamedDecl *D, 1764 Sema::AcceptableKind Kind) { 1765 assert(!D->isUnconditionallyVisible() && 1766 "should not call this: not in slow case"); 1767 1768 Module *DeclModule = SemaRef.getOwningModule(D); 1769 assert(DeclModule && "hidden decl has no owning module"); 1770 1771 // If the owning module is visible, the decl is acceptable. 1772 if (SemaRef.isModuleVisible(DeclModule, 1773 D->isInvisibleOutsideTheOwningModule())) 1774 return true; 1775 1776 // Determine whether a decl context is a file context for the purpose of 1777 // visibility/reachability. This looks through some (export and linkage spec) 1778 // transparent contexts, but not others (enums). 1779 auto IsEffectivelyFileContext = [](const DeclContext *DC) { 1780 return DC->isFileContext() || isa<LinkageSpecDecl>(DC) || 1781 isa<ExportDecl>(DC); 1782 }; 1783 1784 // If this declaration is not at namespace scope 1785 // then it is acceptable if its lexical parent has a acceptable definition. 1786 DeclContext *DC = D->getLexicalDeclContext(); 1787 if (DC && !IsEffectivelyFileContext(DC)) { 1788 // For a parameter, check whether our current template declaration's 1789 // lexical context is acceptable, not whether there's some other acceptable 1790 // definition of it, because parameters aren't "within" the definition. 1791 // 1792 // In C++ we need to check for a acceptable definition due to ODR merging, 1793 // and in C we must not because each declaration of a function gets its own 1794 // set of declarations for tags in prototype scope. 1795 bool AcceptableWithinParent; 1796 if (D->isTemplateParameter()) { 1797 bool SearchDefinitions = true; 1798 if (const auto *DCD = dyn_cast<Decl>(DC)) { 1799 if (const auto *TD = DCD->getDescribedTemplate()) { 1800 TemplateParameterList *TPL = TD->getTemplateParameters(); 1801 auto Index = getDepthAndIndex(D).second; 1802 SearchDefinitions = Index >= TPL->size() || TPL->getParam(Index) != D; 1803 } 1804 } 1805 if (SearchDefinitions) 1806 AcceptableWithinParent = 1807 SemaRef.hasAcceptableDefinition(cast<NamedDecl>(DC), Kind); 1808 else 1809 AcceptableWithinParent = 1810 isAcceptable(SemaRef, cast<NamedDecl>(DC), Kind); 1811 } else if (isa<ParmVarDecl>(D) || 1812 (isa<FunctionDecl>(DC) && !SemaRef.getLangOpts().CPlusPlus)) 1813 AcceptableWithinParent = isAcceptable(SemaRef, cast<NamedDecl>(DC), Kind); 1814 else if (D->isModulePrivate()) { 1815 // A module-private declaration is only acceptable if an enclosing lexical 1816 // parent was merged with another definition in the current module. 1817 AcceptableWithinParent = false; 1818 do { 1819 if (SemaRef.hasMergedDefinitionInCurrentModule(cast<NamedDecl>(DC))) { 1820 AcceptableWithinParent = true; 1821 break; 1822 } 1823 DC = DC->getLexicalParent(); 1824 } while (!IsEffectivelyFileContext(DC)); 1825 } else { 1826 AcceptableWithinParent = 1827 SemaRef.hasAcceptableDefinition(cast<NamedDecl>(DC), Kind); 1828 } 1829 1830 if (AcceptableWithinParent && SemaRef.CodeSynthesisContexts.empty() && 1831 Kind == Sema::AcceptableKind::Visible && 1832 // FIXME: Do something better in this case. 1833 !SemaRef.getLangOpts().ModulesLocalVisibility) { 1834 // Cache the fact that this declaration is implicitly visible because 1835 // its parent has a visible definition. 1836 D->setVisibleDespiteOwningModule(); 1837 } 1838 return AcceptableWithinParent; 1839 } 1840 1841 if (Kind == Sema::AcceptableKind::Visible) 1842 return false; 1843 1844 assert(Kind == Sema::AcceptableKind::Reachable && 1845 "Additional Sema::AcceptableKind?"); 1846 return isReachableSlow(SemaRef, D); 1847 } 1848 1849 bool Sema::isModuleVisible(const Module *M, bool ModulePrivate) { 1850 // [module.global.frag]p2: 1851 // A global-module-fragment specifies the contents of the global module 1852 // fragment for a module unit. The global module fragment can be used to 1853 // provide declarations that are attached to the global module and usable 1854 // within the module unit. 1855 // 1856 // Global module fragment is special. Global Module fragment is only usable 1857 // within the module unit it got defined [module.global.frag]p2. So here we 1858 // check if the Module is the global module fragment in current translation 1859 // unit. 1860 if (M->isGlobalModule() && M != this->GlobalModuleFragment) 1861 return false; 1862 1863 // The module might be ordinarily visible. For a module-private query, that 1864 // means it is part of the current module. 1865 if (ModulePrivate && isUsableModule(M)) 1866 return true; 1867 1868 // For a query which is not module-private, that means it is in our visible 1869 // module set. 1870 if (!ModulePrivate && VisibleModules.isVisible(M)) 1871 return true; 1872 1873 // Otherwise, it might be visible by virtue of the query being within a 1874 // template instantiation or similar that is permitted to look inside M. 1875 1876 // Find the extra places where we need to look. 1877 const auto &LookupModules = getLookupModules(); 1878 if (LookupModules.empty()) 1879 return false; 1880 1881 // If our lookup set contains the module, it's visible. 1882 if (LookupModules.count(M)) 1883 return true; 1884 1885 // For a module-private query, that's everywhere we get to look. 1886 if (ModulePrivate) 1887 return false; 1888 1889 // Check whether M is transitively exported to an import of the lookup set. 1890 return llvm::any_of(LookupModules, [&](const Module *LookupM) { 1891 return LookupM->isModuleVisible(M); 1892 }); 1893 } 1894 1895 // FIXME: Return false directly if we don't have an interface dependency on the 1896 // translation unit containing D. 1897 bool LookupResult::isReachableSlow(Sema &SemaRef, NamedDecl *D) { 1898 assert(!isVisible(SemaRef, D) && "Shouldn't call the slow case.\n"); 1899 1900 Module *DeclModule = SemaRef.getOwningModule(D); 1901 assert(DeclModule && "hidden decl has no owning module"); 1902 1903 // Entities in module map modules are reachable only if they're visible. 1904 if (DeclModule->isModuleMapModule()) 1905 return false; 1906 1907 // If D comes from a module and SemaRef doesn't own a module, it implies D 1908 // comes from another TU. In case SemaRef owns a module, we could judge if D 1909 // comes from another TU by comparing the module unit. 1910 // 1911 // FIXME: It would look better if we have direct method to judge whether D is 1912 // in another TU. 1913 if (SemaRef.getCurrentModule() && 1914 SemaRef.getCurrentModule()->getTopLevelModule() == 1915 DeclModule->getTopLevelModule()) 1916 return true; 1917 1918 // [module.reach]/p3: 1919 // A declaration D is reachable from a point P if: 1920 // ... 1921 // - D is not discarded ([module.global.frag]), appears in a translation unit 1922 // that is reachable from P, and does not appear within a private module 1923 // fragment. 1924 // 1925 // A declaration that's discarded in the GMF should be module-private. 1926 if (D->isModulePrivate()) 1927 return false; 1928 1929 // [module.reach]/p1 1930 // A translation unit U is necessarily reachable from a point P if U is a 1931 // module interface unit on which the translation unit containing P has an 1932 // interface dependency, or the translation unit containing P imports U, in 1933 // either case prior to P ([module.import]). 1934 // 1935 // [module.import]/p10 1936 // A translation unit has an interface dependency on a translation unit U if 1937 // it contains a declaration (possibly a module-declaration) that imports U 1938 // or if it has an interface dependency on a translation unit that has an 1939 // interface dependency on U. 1940 // 1941 // So we could conclude the module unit U is necessarily reachable if: 1942 // (1) The module unit U is module interface unit. 1943 // (2) The current unit has an interface dependency on the module unit U. 1944 // 1945 // Here we only check for the first condition. Since we couldn't see 1946 // DeclModule if it isn't (transitively) imported. 1947 if (DeclModule->getTopLevelModule()->isModuleInterfaceUnit()) 1948 return true; 1949 1950 // [module.reach]/p2 1951 // Additional translation units on 1952 // which the point within the program has an interface dependency may be 1953 // considered reachable, but it is unspecified which are and under what 1954 // circumstances. 1955 // 1956 // The decision here is to treat all additional tranditional units as 1957 // unreachable. 1958 return false; 1959 } 1960 1961 bool Sema::isAcceptableSlow(const NamedDecl *D, Sema::AcceptableKind Kind) { 1962 return LookupResult::isAcceptable(*this, const_cast<NamedDecl *>(D), Kind); 1963 } 1964 1965 bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) { 1966 // FIXME: If there are both visible and hidden declarations, we need to take 1967 // into account whether redeclaration is possible. Example: 1968 // 1969 // Non-imported module: 1970 // int f(T); // #1 1971 // Some TU: 1972 // static int f(U); // #2, not a redeclaration of #1 1973 // int f(T); // #3, finds both, should link with #1 if T != U, but 1974 // // with #2 if T == U; neither should be ambiguous. 1975 for (auto *D : R) { 1976 if (isVisible(D)) 1977 return true; 1978 assert(D->isExternallyDeclarable() && 1979 "should not have hidden, non-externally-declarable result here"); 1980 } 1981 1982 // This function is called once "New" is essentially complete, but before a 1983 // previous declaration is attached. We can't query the linkage of "New" in 1984 // general, because attaching the previous declaration can change the 1985 // linkage of New to match the previous declaration. 1986 // 1987 // However, because we've just determined that there is no *visible* prior 1988 // declaration, we can compute the linkage here. There are two possibilities: 1989 // 1990 // * This is not a redeclaration; it's safe to compute the linkage now. 1991 // 1992 // * This is a redeclaration of a prior declaration that is externally 1993 // redeclarable. In that case, the linkage of the declaration is not 1994 // changed by attaching the prior declaration, because both are externally 1995 // declarable (and thus ExternalLinkage or VisibleNoLinkage). 1996 // 1997 // FIXME: This is subtle and fragile. 1998 return New->isExternallyDeclarable(); 1999 } 2000 2001 /// Retrieve the visible declaration corresponding to D, if any. 2002 /// 2003 /// This routine determines whether the declaration D is visible in the current 2004 /// module, with the current imports. If not, it checks whether any 2005 /// redeclaration of D is visible, and if so, returns that declaration. 2006 /// 2007 /// \returns D, or a visible previous declaration of D, whichever is more recent 2008 /// and visible. If no declaration of D is visible, returns null. 2009 static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D, 2010 unsigned IDNS) { 2011 assert(!LookupResult::isAvailableForLookup(SemaRef, D) && "not in slow case"); 2012 2013 for (auto RD : D->redecls()) { 2014 // Don't bother with extra checks if we already know this one isn't visible. 2015 if (RD == D) 2016 continue; 2017 2018 auto ND = cast<NamedDecl>(RD); 2019 // FIXME: This is wrong in the case where the previous declaration is not 2020 // visible in the same scope as D. This needs to be done much more 2021 // carefully. 2022 if (ND->isInIdentifierNamespace(IDNS) && 2023 LookupResult::isAvailableForLookup(SemaRef, ND)) 2024 return ND; 2025 } 2026 2027 return nullptr; 2028 } 2029 2030 bool Sema::hasVisibleDeclarationSlow(const NamedDecl *D, 2031 llvm::SmallVectorImpl<Module *> *Modules) { 2032 assert(!isVisible(D) && "not in slow case"); 2033 return hasAcceptableDeclarationImpl( 2034 *this, D, Modules, [](const NamedDecl *) { return true; }, 2035 Sema::AcceptableKind::Visible); 2036 } 2037 2038 bool Sema::hasReachableDeclarationSlow( 2039 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 2040 assert(!isReachable(D) && "not in slow case"); 2041 return hasAcceptableDeclarationImpl( 2042 *this, D, Modules, [](const NamedDecl *) { return true; }, 2043 Sema::AcceptableKind::Reachable); 2044 } 2045 2046 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const { 2047 if (auto *ND = dyn_cast<NamespaceDecl>(D)) { 2048 // Namespaces are a bit of a special case: we expect there to be a lot of 2049 // redeclarations of some namespaces, all declarations of a namespace are 2050 // essentially interchangeable, all declarations are found by name lookup 2051 // if any is, and namespaces are never looked up during template 2052 // instantiation. So we benefit from caching the check in this case, and 2053 // it is correct to do so. 2054 auto *Key = ND->getCanonicalDecl(); 2055 if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Key)) 2056 return Acceptable; 2057 auto *Acceptable = isVisible(getSema(), Key) 2058 ? Key 2059 : findAcceptableDecl(getSema(), Key, IDNS); 2060 if (Acceptable) 2061 getSema().VisibleNamespaceCache.insert(std::make_pair(Key, Acceptable)); 2062 return Acceptable; 2063 } 2064 2065 return findAcceptableDecl(getSema(), D, IDNS); 2066 } 2067 2068 bool LookupResult::isVisible(Sema &SemaRef, NamedDecl *D) { 2069 // If this declaration is already visible, return it directly. 2070 if (D->isUnconditionallyVisible()) 2071 return true; 2072 2073 // During template instantiation, we can refer to hidden declarations, if 2074 // they were visible in any module along the path of instantiation. 2075 return isAcceptableSlow(SemaRef, D, Sema::AcceptableKind::Visible); 2076 } 2077 2078 bool LookupResult::isReachable(Sema &SemaRef, NamedDecl *D) { 2079 if (D->isUnconditionallyVisible()) 2080 return true; 2081 2082 return isAcceptableSlow(SemaRef, D, Sema::AcceptableKind::Reachable); 2083 } 2084 2085 bool LookupResult::isAvailableForLookup(Sema &SemaRef, NamedDecl *ND) { 2086 // We should check the visibility at the callsite already. 2087 if (isVisible(SemaRef, ND)) 2088 return true; 2089 2090 auto *DC = ND->getDeclContext(); 2091 // If ND is not visible and it is at namespace scope, it shouldn't be found 2092 // by name lookup. 2093 if (DC->isFileContext()) 2094 return false; 2095 2096 // [module.interface]p7 2097 // Class and enumeration member names can be found by name lookup in any 2098 // context in which a definition of the type is reachable. 2099 // 2100 // FIXME: The current implementation didn't consider about scope. For example, 2101 // ``` 2102 // // m.cppm 2103 // export module m; 2104 // enum E1 { e1 }; 2105 // // Use.cpp 2106 // import m; 2107 // void test() { 2108 // auto a = E1::e1; // Error as expected. 2109 // auto b = e1; // Should be error. namespace-scope name e1 is not visible 2110 // } 2111 // ``` 2112 // For the above example, the current implementation would emit error for `a` 2113 // correctly. However, the implementation wouldn't diagnose about `b` now. 2114 // Since we only check the reachability for the parent only. 2115 // See clang/test/CXX/module/module.interface/p7.cpp for example. 2116 if (auto *TD = dyn_cast<TagDecl>(DC)) 2117 return SemaRef.hasReachableDefinition(TD); 2118 2119 return false; 2120 } 2121 2122 /// Perform unqualified name lookup starting from a given 2123 /// scope. 2124 /// 2125 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is 2126 /// used to find names within the current scope. For example, 'x' in 2127 /// @code 2128 /// int x; 2129 /// int f() { 2130 /// return x; // unqualified name look finds 'x' in the global scope 2131 /// } 2132 /// @endcode 2133 /// 2134 /// Different lookup criteria can find different names. For example, a 2135 /// particular scope can have both a struct and a function of the same 2136 /// name, and each can be found by certain lookup criteria. For more 2137 /// information about lookup criteria, see the documentation for the 2138 /// class LookupCriteria. 2139 /// 2140 /// @param S The scope from which unqualified name lookup will 2141 /// begin. If the lookup criteria permits, name lookup may also search 2142 /// in the parent scopes. 2143 /// 2144 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to 2145 /// look up and the lookup kind), and is updated with the results of lookup 2146 /// including zero or more declarations and possibly additional information 2147 /// used to diagnose ambiguities. 2148 /// 2149 /// @returns \c true if lookup succeeded and false otherwise. 2150 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation, 2151 bool ForceNoCPlusPlus) { 2152 DeclarationName Name = R.getLookupName(); 2153 if (!Name) return false; 2154 2155 LookupNameKind NameKind = R.getLookupKind(); 2156 2157 if (!getLangOpts().CPlusPlus || ForceNoCPlusPlus) { 2158 // Unqualified name lookup in C/Objective-C is purely lexical, so 2159 // search in the declarations attached to the name. 2160 if (NameKind == Sema::LookupRedeclarationWithLinkage) { 2161 // Find the nearest non-transparent declaration scope. 2162 while (!(S->getFlags() & Scope::DeclScope) || 2163 (S->getEntity() && S->getEntity()->isTransparentContext())) 2164 S = S->getParent(); 2165 } 2166 2167 // When performing a scope lookup, we want to find local extern decls. 2168 FindLocalExternScope FindLocals(R); 2169 2170 // Scan up the scope chain looking for a decl that matches this 2171 // identifier that is in the appropriate namespace. This search 2172 // should not take long, as shadowing of names is uncommon, and 2173 // deep shadowing is extremely uncommon. 2174 bool LeftStartingScope = false; 2175 2176 for (IdentifierResolver::iterator I = IdResolver.begin(Name), 2177 IEnd = IdResolver.end(); 2178 I != IEnd; ++I) 2179 if (NamedDecl *D = R.getAcceptableDecl(*I)) { 2180 if (NameKind == LookupRedeclarationWithLinkage) { 2181 // Determine whether this (or a previous) declaration is 2182 // out-of-scope. 2183 if (!LeftStartingScope && !S->isDeclScope(*I)) 2184 LeftStartingScope = true; 2185 2186 // If we found something outside of our starting scope that 2187 // does not have linkage, skip it. 2188 if (LeftStartingScope && !((*I)->hasLinkage())) { 2189 R.setShadowed(); 2190 continue; 2191 } 2192 } 2193 else if (NameKind == LookupObjCImplicitSelfParam && 2194 !isa<ImplicitParamDecl>(*I)) 2195 continue; 2196 2197 R.addDecl(D); 2198 2199 // Check whether there are any other declarations with the same name 2200 // and in the same scope. 2201 if (I != IEnd) { 2202 // Find the scope in which this declaration was declared (if it 2203 // actually exists in a Scope). 2204 while (S && !S->isDeclScope(D)) 2205 S = S->getParent(); 2206 2207 // If the scope containing the declaration is the translation unit, 2208 // then we'll need to perform our checks based on the matching 2209 // DeclContexts rather than matching scopes. 2210 if (S && isNamespaceOrTranslationUnitScope(S)) 2211 S = nullptr; 2212 2213 // Compute the DeclContext, if we need it. 2214 DeclContext *DC = nullptr; 2215 if (!S) 2216 DC = (*I)->getDeclContext()->getRedeclContext(); 2217 2218 IdentifierResolver::iterator LastI = I; 2219 for (++LastI; LastI != IEnd; ++LastI) { 2220 if (S) { 2221 // Match based on scope. 2222 if (!S->isDeclScope(*LastI)) 2223 break; 2224 } else { 2225 // Match based on DeclContext. 2226 DeclContext *LastDC 2227 = (*LastI)->getDeclContext()->getRedeclContext(); 2228 if (!LastDC->Equals(DC)) 2229 break; 2230 } 2231 2232 // If the declaration is in the right namespace and visible, add it. 2233 if (NamedDecl *LastD = R.getAcceptableDecl(*LastI)) 2234 R.addDecl(LastD); 2235 } 2236 2237 R.resolveKind(); 2238 } 2239 2240 return true; 2241 } 2242 } else { 2243 // Perform C++ unqualified name lookup. 2244 if (CppLookupName(R, S)) 2245 return true; 2246 } 2247 2248 // If we didn't find a use of this identifier, and if the identifier 2249 // corresponds to a compiler builtin, create the decl object for the builtin 2250 // now, injecting it into translation unit scope, and return it. 2251 if (AllowBuiltinCreation && LookupBuiltin(R)) 2252 return true; 2253 2254 // If we didn't find a use of this identifier, the ExternalSource 2255 // may be able to handle the situation. 2256 // Note: some lookup failures are expected! 2257 // See e.g. R.isForRedeclaration(). 2258 return (ExternalSource && ExternalSource->LookupUnqualified(R, S)); 2259 } 2260 2261 /// Perform qualified name lookup in the namespaces nominated by 2262 /// using directives by the given context. 2263 /// 2264 /// C++98 [namespace.qual]p2: 2265 /// Given X::m (where X is a user-declared namespace), or given \::m 2266 /// (where X is the global namespace), let S be the set of all 2267 /// declarations of m in X and in the transitive closure of all 2268 /// namespaces nominated by using-directives in X and its used 2269 /// namespaces, except that using-directives are ignored in any 2270 /// namespace, including X, directly containing one or more 2271 /// declarations of m. No namespace is searched more than once in 2272 /// the lookup of a name. If S is the empty set, the program is 2273 /// ill-formed. Otherwise, if S has exactly one member, or if the 2274 /// context of the reference is a using-declaration 2275 /// (namespace.udecl), S is the required set of declarations of 2276 /// m. Otherwise if the use of m is not one that allows a unique 2277 /// declaration to be chosen from S, the program is ill-formed. 2278 /// 2279 /// C++98 [namespace.qual]p5: 2280 /// During the lookup of a qualified namespace member name, if the 2281 /// lookup finds more than one declaration of the member, and if one 2282 /// declaration introduces a class name or enumeration name and the 2283 /// other declarations either introduce the same object, the same 2284 /// enumerator or a set of functions, the non-type name hides the 2285 /// class or enumeration name if and only if the declarations are 2286 /// from the same namespace; otherwise (the declarations are from 2287 /// different namespaces), the program is ill-formed. 2288 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R, 2289 DeclContext *StartDC) { 2290 assert(StartDC->isFileContext() && "start context is not a file context"); 2291 2292 // We have not yet looked into these namespaces, much less added 2293 // their "using-children" to the queue. 2294 SmallVector<NamespaceDecl*, 8> Queue; 2295 2296 // We have at least added all these contexts to the queue. 2297 llvm::SmallPtrSet<DeclContext*, 8> Visited; 2298 Visited.insert(StartDC); 2299 2300 // We have already looked into the initial namespace; seed the queue 2301 // with its using-children. 2302 for (auto *I : StartDC->using_directives()) { 2303 NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace(); 2304 if (S.isVisible(I) && Visited.insert(ND).second) 2305 Queue.push_back(ND); 2306 } 2307 2308 // The easiest way to implement the restriction in [namespace.qual]p5 2309 // is to check whether any of the individual results found a tag 2310 // and, if so, to declare an ambiguity if the final result is not 2311 // a tag. 2312 bool FoundTag = false; 2313 bool FoundNonTag = false; 2314 2315 LookupResult LocalR(LookupResult::Temporary, R); 2316 2317 bool Found = false; 2318 while (!Queue.empty()) { 2319 NamespaceDecl *ND = Queue.pop_back_val(); 2320 2321 // We go through some convolutions here to avoid copying results 2322 // between LookupResults. 2323 bool UseLocal = !R.empty(); 2324 LookupResult &DirectR = UseLocal ? LocalR : R; 2325 bool FoundDirect = LookupDirect(S, DirectR, ND); 2326 2327 if (FoundDirect) { 2328 // First do any local hiding. 2329 DirectR.resolveKind(); 2330 2331 // If the local result is a tag, remember that. 2332 if (DirectR.isSingleTagDecl()) 2333 FoundTag = true; 2334 else 2335 FoundNonTag = true; 2336 2337 // Append the local results to the total results if necessary. 2338 if (UseLocal) { 2339 R.addAllDecls(LocalR); 2340 LocalR.clear(); 2341 } 2342 } 2343 2344 // If we find names in this namespace, ignore its using directives. 2345 if (FoundDirect) { 2346 Found = true; 2347 continue; 2348 } 2349 2350 for (auto I : ND->using_directives()) { 2351 NamespaceDecl *Nom = I->getNominatedNamespace(); 2352 if (S.isVisible(I) && Visited.insert(Nom).second) 2353 Queue.push_back(Nom); 2354 } 2355 } 2356 2357 if (Found) { 2358 if (FoundTag && FoundNonTag) 2359 R.setAmbiguousQualifiedTagHiding(); 2360 else 2361 R.resolveKind(); 2362 } 2363 2364 return Found; 2365 } 2366 2367 /// Perform qualified name lookup into a given context. 2368 /// 2369 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find 2370 /// names when the context of those names is explicit specified, e.g., 2371 /// "std::vector" or "x->member", or as part of unqualified name lookup. 2372 /// 2373 /// Different lookup criteria can find different names. For example, a 2374 /// particular scope can have both a struct and a function of the same 2375 /// name, and each can be found by certain lookup criteria. For more 2376 /// information about lookup criteria, see the documentation for the 2377 /// class LookupCriteria. 2378 /// 2379 /// \param R captures both the lookup criteria and any lookup results found. 2380 /// 2381 /// \param LookupCtx The context in which qualified name lookup will 2382 /// search. If the lookup criteria permits, name lookup may also search 2383 /// in the parent contexts or (for C++ classes) base classes. 2384 /// 2385 /// \param InUnqualifiedLookup true if this is qualified name lookup that 2386 /// occurs as part of unqualified name lookup. 2387 /// 2388 /// \returns true if lookup succeeded, false if it failed. 2389 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 2390 bool InUnqualifiedLookup) { 2391 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context"); 2392 2393 if (!R.getLookupName()) 2394 return false; 2395 2396 // Make sure that the declaration context is complete. 2397 assert((!isa<TagDecl>(LookupCtx) || 2398 LookupCtx->isDependentContext() || 2399 cast<TagDecl>(LookupCtx)->isCompleteDefinition() || 2400 cast<TagDecl>(LookupCtx)->isBeingDefined()) && 2401 "Declaration context must already be complete!"); 2402 2403 struct QualifiedLookupInScope { 2404 bool oldVal; 2405 DeclContext *Context; 2406 // Set flag in DeclContext informing debugger that we're looking for qualified name 2407 QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) { 2408 oldVal = ctx->setUseQualifiedLookup(); 2409 } 2410 ~QualifiedLookupInScope() { 2411 Context->setUseQualifiedLookup(oldVal); 2412 } 2413 } QL(LookupCtx); 2414 2415 if (LookupDirect(*this, R, LookupCtx)) { 2416 R.resolveKind(); 2417 if (isa<CXXRecordDecl>(LookupCtx)) 2418 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx)); 2419 return true; 2420 } 2421 2422 // Don't descend into implied contexts for redeclarations. 2423 // C++98 [namespace.qual]p6: 2424 // In a declaration for a namespace member in which the 2425 // declarator-id is a qualified-id, given that the qualified-id 2426 // for the namespace member has the form 2427 // nested-name-specifier unqualified-id 2428 // the unqualified-id shall name a member of the namespace 2429 // designated by the nested-name-specifier. 2430 // See also [class.mfct]p5 and [class.static.data]p2. 2431 if (R.isForRedeclaration()) 2432 return false; 2433 2434 // If this is a namespace, look it up in the implied namespaces. 2435 if (LookupCtx->isFileContext()) 2436 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx); 2437 2438 // If this isn't a C++ class, we aren't allowed to look into base 2439 // classes, we're done. 2440 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx); 2441 if (!LookupRec || !LookupRec->getDefinition()) 2442 return false; 2443 2444 // We're done for lookups that can never succeed for C++ classes. 2445 if (R.getLookupKind() == LookupOperatorName || 2446 R.getLookupKind() == LookupNamespaceName || 2447 R.getLookupKind() == LookupObjCProtocolName || 2448 R.getLookupKind() == LookupLabel) 2449 return false; 2450 2451 // If we're performing qualified name lookup into a dependent class, 2452 // then we are actually looking into a current instantiation. If we have any 2453 // dependent base classes, then we either have to delay lookup until 2454 // template instantiation time (at which point all bases will be available) 2455 // or we have to fail. 2456 if (!InUnqualifiedLookup && LookupRec->isDependentContext() && 2457 LookupRec->hasAnyDependentBases()) { 2458 R.setNotFoundInCurrentInstantiation(); 2459 return false; 2460 } 2461 2462 // Perform lookup into our base classes. 2463 2464 DeclarationName Name = R.getLookupName(); 2465 unsigned IDNS = R.getIdentifierNamespace(); 2466 2467 // Look for this member in our base classes. 2468 auto BaseCallback = [Name, IDNS](const CXXBaseSpecifier *Specifier, 2469 CXXBasePath &Path) -> bool { 2470 CXXRecordDecl *BaseRecord = Specifier->getType()->getAsCXXRecordDecl(); 2471 // Drop leading non-matching lookup results from the declaration list so 2472 // we don't need to consider them again below. 2473 for (Path.Decls = BaseRecord->lookup(Name).begin(); 2474 Path.Decls != Path.Decls.end(); ++Path.Decls) { 2475 if ((*Path.Decls)->isInIdentifierNamespace(IDNS)) 2476 return true; 2477 } 2478 return false; 2479 }; 2480 2481 CXXBasePaths Paths; 2482 Paths.setOrigin(LookupRec); 2483 if (!LookupRec->lookupInBases(BaseCallback, Paths)) 2484 return false; 2485 2486 R.setNamingClass(LookupRec); 2487 2488 // C++ [class.member.lookup]p2: 2489 // [...] If the resulting set of declarations are not all from 2490 // sub-objects of the same type, or the set has a nonstatic member 2491 // and includes members from distinct sub-objects, there is an 2492 // ambiguity and the program is ill-formed. Otherwise that set is 2493 // the result of the lookup. 2494 QualType SubobjectType; 2495 int SubobjectNumber = 0; 2496 AccessSpecifier SubobjectAccess = AS_none; 2497 2498 // Check whether the given lookup result contains only static members. 2499 auto HasOnlyStaticMembers = [&](DeclContext::lookup_iterator Result) { 2500 for (DeclContext::lookup_iterator I = Result, E = I.end(); I != E; ++I) 2501 if ((*I)->isInIdentifierNamespace(IDNS) && (*I)->isCXXInstanceMember()) 2502 return false; 2503 return true; 2504 }; 2505 2506 bool TemplateNameLookup = R.isTemplateNameLookup(); 2507 2508 // Determine whether two sets of members contain the same members, as 2509 // required by C++ [class.member.lookup]p6. 2510 auto HasSameDeclarations = [&](DeclContext::lookup_iterator A, 2511 DeclContext::lookup_iterator B) { 2512 using Iterator = DeclContextLookupResult::iterator; 2513 using Result = const void *; 2514 2515 auto Next = [&](Iterator &It, Iterator End) -> Result { 2516 while (It != End) { 2517 NamedDecl *ND = *It++; 2518 if (!ND->isInIdentifierNamespace(IDNS)) 2519 continue; 2520 2521 // C++ [temp.local]p3: 2522 // A lookup that finds an injected-class-name (10.2) can result in 2523 // an ambiguity in certain cases (for example, if it is found in 2524 // more than one base class). If all of the injected-class-names 2525 // that are found refer to specializations of the same class 2526 // template, and if the name is used as a template-name, the 2527 // reference refers to the class template itself and not a 2528 // specialization thereof, and is not ambiguous. 2529 if (TemplateNameLookup) 2530 if (auto *TD = getAsTemplateNameDecl(ND)) 2531 ND = TD; 2532 2533 // C++ [class.member.lookup]p3: 2534 // type declarations (including injected-class-names) are replaced by 2535 // the types they designate 2536 if (const TypeDecl *TD = dyn_cast<TypeDecl>(ND->getUnderlyingDecl())) { 2537 QualType T = Context.getTypeDeclType(TD); 2538 return T.getCanonicalType().getAsOpaquePtr(); 2539 } 2540 2541 return ND->getUnderlyingDecl()->getCanonicalDecl(); 2542 } 2543 return nullptr; 2544 }; 2545 2546 // We'll often find the declarations are in the same order. Handle this 2547 // case (and the special case of only one declaration) efficiently. 2548 Iterator AIt = A, BIt = B, AEnd, BEnd; 2549 while (true) { 2550 Result AResult = Next(AIt, AEnd); 2551 Result BResult = Next(BIt, BEnd); 2552 if (!AResult && !BResult) 2553 return true; 2554 if (!AResult || !BResult) 2555 return false; 2556 if (AResult != BResult) { 2557 // Found a mismatch; carefully check both lists, accounting for the 2558 // possibility of declarations appearing more than once. 2559 llvm::SmallDenseMap<Result, bool, 32> AResults; 2560 for (; AResult; AResult = Next(AIt, AEnd)) 2561 AResults.insert({AResult, /*FoundInB*/false}); 2562 unsigned Found = 0; 2563 for (; BResult; BResult = Next(BIt, BEnd)) { 2564 auto It = AResults.find(BResult); 2565 if (It == AResults.end()) 2566 return false; 2567 if (!It->second) { 2568 It->second = true; 2569 ++Found; 2570 } 2571 } 2572 return AResults.size() == Found; 2573 } 2574 } 2575 }; 2576 2577 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); 2578 Path != PathEnd; ++Path) { 2579 const CXXBasePathElement &PathElement = Path->back(); 2580 2581 // Pick the best (i.e. most permissive i.e. numerically lowest) access 2582 // across all paths. 2583 SubobjectAccess = std::min(SubobjectAccess, Path->Access); 2584 2585 // Determine whether we're looking at a distinct sub-object or not. 2586 if (SubobjectType.isNull()) { 2587 // This is the first subobject we've looked at. Record its type. 2588 SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); 2589 SubobjectNumber = PathElement.SubobjectNumber; 2590 continue; 2591 } 2592 2593 if (SubobjectType != 2594 Context.getCanonicalType(PathElement.Base->getType())) { 2595 // We found members of the given name in two subobjects of 2596 // different types. If the declaration sets aren't the same, this 2597 // lookup is ambiguous. 2598 // 2599 // FIXME: The language rule says that this applies irrespective of 2600 // whether the sets contain only static members. 2601 if (HasOnlyStaticMembers(Path->Decls) && 2602 HasSameDeclarations(Paths.begin()->Decls, Path->Decls)) 2603 continue; 2604 2605 R.setAmbiguousBaseSubobjectTypes(Paths); 2606 return true; 2607 } 2608 2609 // FIXME: This language rule no longer exists. Checking for ambiguous base 2610 // subobjects should be done as part of formation of a class member access 2611 // expression (when converting the object parameter to the member's type). 2612 if (SubobjectNumber != PathElement.SubobjectNumber) { 2613 // We have a different subobject of the same type. 2614 2615 // C++ [class.member.lookup]p5: 2616 // A static member, a nested type or an enumerator defined in 2617 // a base class T can unambiguously be found even if an object 2618 // has more than one base class subobject of type T. 2619 if (HasOnlyStaticMembers(Path->Decls)) 2620 continue; 2621 2622 // We have found a nonstatic member name in multiple, distinct 2623 // subobjects. Name lookup is ambiguous. 2624 R.setAmbiguousBaseSubobjects(Paths); 2625 return true; 2626 } 2627 } 2628 2629 // Lookup in a base class succeeded; return these results. 2630 2631 for (DeclContext::lookup_iterator I = Paths.front().Decls, E = I.end(); 2632 I != E; ++I) { 2633 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess, 2634 (*I)->getAccess()); 2635 if (NamedDecl *ND = R.getAcceptableDecl(*I)) 2636 R.addDecl(ND, AS); 2637 } 2638 R.resolveKind(); 2639 return true; 2640 } 2641 2642 /// Performs qualified name lookup or special type of lookup for 2643 /// "__super::" scope specifier. 2644 /// 2645 /// This routine is a convenience overload meant to be called from contexts 2646 /// that need to perform a qualified name lookup with an optional C++ scope 2647 /// specifier that might require special kind of lookup. 2648 /// 2649 /// \param R captures both the lookup criteria and any lookup results found. 2650 /// 2651 /// \param LookupCtx The context in which qualified name lookup will 2652 /// search. 2653 /// 2654 /// \param SS An optional C++ scope-specifier. 2655 /// 2656 /// \returns true if lookup succeeded, false if it failed. 2657 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 2658 CXXScopeSpec &SS) { 2659 auto *NNS = SS.getScopeRep(); 2660 if (NNS && NNS->getKind() == NestedNameSpecifier::Super) 2661 return LookupInSuper(R, NNS->getAsRecordDecl()); 2662 else 2663 2664 return LookupQualifiedName(R, LookupCtx); 2665 } 2666 2667 /// Performs name lookup for a name that was parsed in the 2668 /// source code, and may contain a C++ scope specifier. 2669 /// 2670 /// This routine is a convenience routine meant to be called from 2671 /// contexts that receive a name and an optional C++ scope specifier 2672 /// (e.g., "N::M::x"). It will then perform either qualified or 2673 /// unqualified name lookup (with LookupQualifiedName or LookupName, 2674 /// respectively) on the given name and return those results. It will 2675 /// perform a special type of lookup for "__super::" scope specifier. 2676 /// 2677 /// @param S The scope from which unqualified name lookup will 2678 /// begin. 2679 /// 2680 /// @param SS An optional C++ scope-specifier, e.g., "::N::M". 2681 /// 2682 /// @param EnteringContext Indicates whether we are going to enter the 2683 /// context of the scope-specifier SS (if present). 2684 /// 2685 /// @returns True if any decls were found (but possibly ambiguous) 2686 bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS, 2687 bool AllowBuiltinCreation, bool EnteringContext) { 2688 if (SS && SS->isInvalid()) { 2689 // When the scope specifier is invalid, don't even look for 2690 // anything. 2691 return false; 2692 } 2693 2694 if (SS && SS->isSet()) { 2695 NestedNameSpecifier *NNS = SS->getScopeRep(); 2696 if (NNS->getKind() == NestedNameSpecifier::Super) 2697 return LookupInSuper(R, NNS->getAsRecordDecl()); 2698 2699 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { 2700 // We have resolved the scope specifier to a particular declaration 2701 // contex, and will perform name lookup in that context. 2702 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC)) 2703 return false; 2704 2705 R.setContextRange(SS->getRange()); 2706 return LookupQualifiedName(R, DC); 2707 } 2708 2709 // We could not resolve the scope specified to a specific declaration 2710 // context, which means that SS refers to an unknown specialization. 2711 // Name lookup can't find anything in this case. 2712 R.setNotFoundInCurrentInstantiation(); 2713 R.setContextRange(SS->getRange()); 2714 return false; 2715 } 2716 2717 // Perform unqualified name lookup starting in the given scope. 2718 return LookupName(R, S, AllowBuiltinCreation); 2719 } 2720 2721 /// Perform qualified name lookup into all base classes of the given 2722 /// class. 2723 /// 2724 /// \param R captures both the lookup criteria and any lookup results found. 2725 /// 2726 /// \param Class The context in which qualified name lookup will 2727 /// search. Name lookup will search in all base classes merging the results. 2728 /// 2729 /// @returns True if any decls were found (but possibly ambiguous) 2730 bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) { 2731 // The access-control rules we use here are essentially the rules for 2732 // doing a lookup in Class that just magically skipped the direct 2733 // members of Class itself. That is, the naming class is Class, and the 2734 // access includes the access of the base. 2735 for (const auto &BaseSpec : Class->bases()) { 2736 CXXRecordDecl *RD = cast<CXXRecordDecl>( 2737 BaseSpec.getType()->castAs<RecordType>()->getDecl()); 2738 LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind()); 2739 Result.setBaseObjectType(Context.getRecordType(Class)); 2740 LookupQualifiedName(Result, RD); 2741 2742 // Copy the lookup results into the target, merging the base's access into 2743 // the path access. 2744 for (auto I = Result.begin(), E = Result.end(); I != E; ++I) { 2745 R.addDecl(I.getDecl(), 2746 CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(), 2747 I.getAccess())); 2748 } 2749 2750 Result.suppressDiagnostics(); 2751 } 2752 2753 R.resolveKind(); 2754 R.setNamingClass(Class); 2755 2756 return !R.empty(); 2757 } 2758 2759 /// Produce a diagnostic describing the ambiguity that resulted 2760 /// from name lookup. 2761 /// 2762 /// \param Result The result of the ambiguous lookup to be diagnosed. 2763 void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) { 2764 assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); 2765 2766 DeclarationName Name = Result.getLookupName(); 2767 SourceLocation NameLoc = Result.getNameLoc(); 2768 SourceRange LookupRange = Result.getContextRange(); 2769 2770 switch (Result.getAmbiguityKind()) { 2771 case LookupResult::AmbiguousBaseSubobjects: { 2772 CXXBasePaths *Paths = Result.getBasePaths(); 2773 QualType SubobjectType = Paths->front().back().Base->getType(); 2774 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) 2775 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) 2776 << LookupRange; 2777 2778 DeclContext::lookup_iterator Found = Paths->front().Decls; 2779 while (isa<CXXMethodDecl>(*Found) && 2780 cast<CXXMethodDecl>(*Found)->isStatic()) 2781 ++Found; 2782 2783 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); 2784 break; 2785 } 2786 2787 case LookupResult::AmbiguousBaseSubobjectTypes: { 2788 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) 2789 << Name << LookupRange; 2790 2791 CXXBasePaths *Paths = Result.getBasePaths(); 2792 std::set<const NamedDecl *> DeclsPrinted; 2793 for (CXXBasePaths::paths_iterator Path = Paths->begin(), 2794 PathEnd = Paths->end(); 2795 Path != PathEnd; ++Path) { 2796 const NamedDecl *D = *Path->Decls; 2797 if (!D->isInIdentifierNamespace(Result.getIdentifierNamespace())) 2798 continue; 2799 if (DeclsPrinted.insert(D).second) { 2800 if (const auto *TD = dyn_cast<TypedefNameDecl>(D->getUnderlyingDecl())) 2801 Diag(D->getLocation(), diag::note_ambiguous_member_type_found) 2802 << TD->getUnderlyingType(); 2803 else if (const auto *TD = dyn_cast<TypeDecl>(D->getUnderlyingDecl())) 2804 Diag(D->getLocation(), diag::note_ambiguous_member_type_found) 2805 << Context.getTypeDeclType(TD); 2806 else 2807 Diag(D->getLocation(), diag::note_ambiguous_member_found); 2808 } 2809 } 2810 break; 2811 } 2812 2813 case LookupResult::AmbiguousTagHiding: { 2814 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange; 2815 2816 llvm::SmallPtrSet<NamedDecl*, 8> TagDecls; 2817 2818 for (auto *D : Result) 2819 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 2820 TagDecls.insert(TD); 2821 Diag(TD->getLocation(), diag::note_hidden_tag); 2822 } 2823 2824 for (auto *D : Result) 2825 if (!isa<TagDecl>(D)) 2826 Diag(D->getLocation(), diag::note_hiding_object); 2827 2828 // For recovery purposes, go ahead and implement the hiding. 2829 LookupResult::Filter F = Result.makeFilter(); 2830 while (F.hasNext()) { 2831 if (TagDecls.count(F.next())) 2832 F.erase(); 2833 } 2834 F.done(); 2835 break; 2836 } 2837 2838 case LookupResult::AmbiguousReference: { 2839 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; 2840 2841 for (auto *D : Result) 2842 Diag(D->getLocation(), diag::note_ambiguous_candidate) << D; 2843 break; 2844 } 2845 } 2846 } 2847 2848 namespace { 2849 struct AssociatedLookup { 2850 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc, 2851 Sema::AssociatedNamespaceSet &Namespaces, 2852 Sema::AssociatedClassSet &Classes) 2853 : S(S), Namespaces(Namespaces), Classes(Classes), 2854 InstantiationLoc(InstantiationLoc) { 2855 } 2856 2857 bool addClassTransitive(CXXRecordDecl *RD) { 2858 Classes.insert(RD); 2859 return ClassesTransitive.insert(RD); 2860 } 2861 2862 Sema &S; 2863 Sema::AssociatedNamespaceSet &Namespaces; 2864 Sema::AssociatedClassSet &Classes; 2865 SourceLocation InstantiationLoc; 2866 2867 private: 2868 Sema::AssociatedClassSet ClassesTransitive; 2869 }; 2870 } // end anonymous namespace 2871 2872 static void 2873 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T); 2874 2875 // Given the declaration context \param Ctx of a class, class template or 2876 // enumeration, add the associated namespaces to \param Namespaces as described 2877 // in [basic.lookup.argdep]p2. 2878 static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces, 2879 DeclContext *Ctx) { 2880 // The exact wording has been changed in C++14 as a result of 2881 // CWG 1691 (see also CWG 1690 and CWG 1692). We apply it unconditionally 2882 // to all language versions since it is possible to return a local type 2883 // from a lambda in C++11. 2884 // 2885 // C++14 [basic.lookup.argdep]p2: 2886 // If T is a class type [...]. Its associated namespaces are the innermost 2887 // enclosing namespaces of its associated classes. [...] 2888 // 2889 // If T is an enumeration type, its associated namespace is the innermost 2890 // enclosing namespace of its declaration. [...] 2891 2892 // We additionally skip inline namespaces. The innermost non-inline namespace 2893 // contains all names of all its nested inline namespaces anyway, so we can 2894 // replace the entire inline namespace tree with its root. 2895 while (!Ctx->isFileContext() || Ctx->isInlineNamespace()) 2896 Ctx = Ctx->getParent(); 2897 2898 Namespaces.insert(Ctx->getPrimaryContext()); 2899 } 2900 2901 // Add the associated classes and namespaces for argument-dependent 2902 // lookup that involves a template argument (C++ [basic.lookup.argdep]p2). 2903 static void 2904 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 2905 const TemplateArgument &Arg) { 2906 // C++ [basic.lookup.argdep]p2, last bullet: 2907 // -- [...] ; 2908 switch (Arg.getKind()) { 2909 case TemplateArgument::Null: 2910 break; 2911 2912 case TemplateArgument::Type: 2913 // [...] the namespaces and classes associated with the types of the 2914 // template arguments provided for template type parameters (excluding 2915 // template template parameters) 2916 addAssociatedClassesAndNamespaces(Result, Arg.getAsType()); 2917 break; 2918 2919 case TemplateArgument::Template: 2920 case TemplateArgument::TemplateExpansion: { 2921 // [...] the namespaces in which any template template arguments are 2922 // defined; and the classes in which any member templates used as 2923 // template template arguments are defined. 2924 TemplateName Template = Arg.getAsTemplateOrTemplatePattern(); 2925 if (ClassTemplateDecl *ClassTemplate 2926 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) { 2927 DeclContext *Ctx = ClassTemplate->getDeclContext(); 2928 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2929 Result.Classes.insert(EnclosingClass); 2930 // Add the associated namespace for this class. 2931 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2932 } 2933 break; 2934 } 2935 2936 case TemplateArgument::Declaration: 2937 case TemplateArgument::Integral: 2938 case TemplateArgument::Expression: 2939 case TemplateArgument::NullPtr: 2940 // [Note: non-type template arguments do not contribute to the set of 2941 // associated namespaces. ] 2942 break; 2943 2944 case TemplateArgument::Pack: 2945 for (const auto &P : Arg.pack_elements()) 2946 addAssociatedClassesAndNamespaces(Result, P); 2947 break; 2948 } 2949 } 2950 2951 // Add the associated classes and namespaces for argument-dependent lookup 2952 // with an argument of class type (C++ [basic.lookup.argdep]p2). 2953 static void 2954 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 2955 CXXRecordDecl *Class) { 2956 2957 // Just silently ignore anything whose name is __va_list_tag. 2958 if (Class->getDeclName() == Result.S.VAListTagName) 2959 return; 2960 2961 // C++ [basic.lookup.argdep]p2: 2962 // [...] 2963 // -- If T is a class type (including unions), its associated 2964 // classes are: the class itself; the class of which it is a 2965 // member, if any; and its direct and indirect base classes. 2966 // Its associated namespaces are the innermost enclosing 2967 // namespaces of its associated classes. 2968 2969 // Add the class of which it is a member, if any. 2970 DeclContext *Ctx = Class->getDeclContext(); 2971 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2972 Result.Classes.insert(EnclosingClass); 2973 2974 // Add the associated namespace for this class. 2975 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2976 2977 // -- If T is a template-id, its associated namespaces and classes are 2978 // the namespace in which the template is defined; for member 2979 // templates, the member template's class; the namespaces and classes 2980 // associated with the types of the template arguments provided for 2981 // template type parameters (excluding template template parameters); the 2982 // namespaces in which any template template arguments are defined; and 2983 // the classes in which any member templates used as template template 2984 // arguments are defined. [Note: non-type template arguments do not 2985 // contribute to the set of associated namespaces. ] 2986 if (ClassTemplateSpecializationDecl *Spec 2987 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) { 2988 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); 2989 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2990 Result.Classes.insert(EnclosingClass); 2991 // Add the associated namespace for this class. 2992 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2993 2994 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); 2995 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 2996 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]); 2997 } 2998 2999 // Add the class itself. If we've already transitively visited this class, 3000 // we don't need to visit base classes. 3001 if (!Result.addClassTransitive(Class)) 3002 return; 3003 3004 // Only recurse into base classes for complete types. 3005 if (!Result.S.isCompleteType(Result.InstantiationLoc, 3006 Result.S.Context.getRecordType(Class))) 3007 return; 3008 3009 // Add direct and indirect base classes along with their associated 3010 // namespaces. 3011 SmallVector<CXXRecordDecl *, 32> Bases; 3012 Bases.push_back(Class); 3013 while (!Bases.empty()) { 3014 // Pop this class off the stack. 3015 Class = Bases.pop_back_val(); 3016 3017 // Visit the base classes. 3018 for (const auto &Base : Class->bases()) { 3019 const RecordType *BaseType = Base.getType()->getAs<RecordType>(); 3020 // In dependent contexts, we do ADL twice, and the first time around, 3021 // the base type might be a dependent TemplateSpecializationType, or a 3022 // TemplateTypeParmType. If that happens, simply ignore it. 3023 // FIXME: If we want to support export, we probably need to add the 3024 // namespace of the template in a TemplateSpecializationType, or even 3025 // the classes and namespaces of known non-dependent arguments. 3026 if (!BaseType) 3027 continue; 3028 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 3029 if (Result.addClassTransitive(BaseDecl)) { 3030 // Find the associated namespace for this base class. 3031 DeclContext *BaseCtx = BaseDecl->getDeclContext(); 3032 CollectEnclosingNamespace(Result.Namespaces, BaseCtx); 3033 3034 // Make sure we visit the bases of this base class. 3035 if (BaseDecl->bases_begin() != BaseDecl->bases_end()) 3036 Bases.push_back(BaseDecl); 3037 } 3038 } 3039 } 3040 } 3041 3042 // Add the associated classes and namespaces for 3043 // argument-dependent lookup with an argument of type T 3044 // (C++ [basic.lookup.koenig]p2). 3045 static void 3046 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) { 3047 // C++ [basic.lookup.koenig]p2: 3048 // 3049 // For each argument type T in the function call, there is a set 3050 // of zero or more associated namespaces and a set of zero or more 3051 // associated classes to be considered. The sets of namespaces and 3052 // classes is determined entirely by the types of the function 3053 // arguments (and the namespace of any template template 3054 // argument). Typedef names and using-declarations used to specify 3055 // the types do not contribute to this set. The sets of namespaces 3056 // and classes are determined in the following way: 3057 3058 SmallVector<const Type *, 16> Queue; 3059 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr(); 3060 3061 while (true) { 3062 switch (T->getTypeClass()) { 3063 3064 #define TYPE(Class, Base) 3065 #define DEPENDENT_TYPE(Class, Base) case Type::Class: 3066 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 3067 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class: 3068 #define ABSTRACT_TYPE(Class, Base) 3069 #include "clang/AST/TypeNodes.inc" 3070 // T is canonical. We can also ignore dependent types because 3071 // we don't need to do ADL at the definition point, but if we 3072 // wanted to implement template export (or if we find some other 3073 // use for associated classes and namespaces...) this would be 3074 // wrong. 3075 break; 3076 3077 // -- If T is a pointer to U or an array of U, its associated 3078 // namespaces and classes are those associated with U. 3079 case Type::Pointer: 3080 T = cast<PointerType>(T)->getPointeeType().getTypePtr(); 3081 continue; 3082 case Type::ConstantArray: 3083 case Type::IncompleteArray: 3084 case Type::VariableArray: 3085 T = cast<ArrayType>(T)->getElementType().getTypePtr(); 3086 continue; 3087 3088 // -- If T is a fundamental type, its associated sets of 3089 // namespaces and classes are both empty. 3090 case Type::Builtin: 3091 break; 3092 3093 // -- If T is a class type (including unions), its associated 3094 // classes are: the class itself; the class of which it is 3095 // a member, if any; and its direct and indirect base classes. 3096 // Its associated namespaces are the innermost enclosing 3097 // namespaces of its associated classes. 3098 case Type::Record: { 3099 CXXRecordDecl *Class = 3100 cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl()); 3101 addAssociatedClassesAndNamespaces(Result, Class); 3102 break; 3103 } 3104 3105 // -- If T is an enumeration type, its associated namespace 3106 // is the innermost enclosing namespace of its declaration. 3107 // If it is a class member, its associated class is the 3108 // member’s class; else it has no associated class. 3109 case Type::Enum: { 3110 EnumDecl *Enum = cast<EnumType>(T)->getDecl(); 3111 3112 DeclContext *Ctx = Enum->getDeclContext(); 3113 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 3114 Result.Classes.insert(EnclosingClass); 3115 3116 // Add the associated namespace for this enumeration. 3117 CollectEnclosingNamespace(Result.Namespaces, Ctx); 3118 3119 break; 3120 } 3121 3122 // -- If T is a function type, its associated namespaces and 3123 // classes are those associated with the function parameter 3124 // types and those associated with the return type. 3125 case Type::FunctionProto: { 3126 const FunctionProtoType *Proto = cast<FunctionProtoType>(T); 3127 for (const auto &Arg : Proto->param_types()) 3128 Queue.push_back(Arg.getTypePtr()); 3129 // fallthrough 3130 LLVM_FALLTHROUGH; 3131 } 3132 case Type::FunctionNoProto: { 3133 const FunctionType *FnType = cast<FunctionType>(T); 3134 T = FnType->getReturnType().getTypePtr(); 3135 continue; 3136 } 3137 3138 // -- If T is a pointer to a member function of a class X, its 3139 // associated namespaces and classes are those associated 3140 // with the function parameter types and return type, 3141 // together with those associated with X. 3142 // 3143 // -- If T is a pointer to a data member of class X, its 3144 // associated namespaces and classes are those associated 3145 // with the member type together with those associated with 3146 // X. 3147 case Type::MemberPointer: { 3148 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T); 3149 3150 // Queue up the class type into which this points. 3151 Queue.push_back(MemberPtr->getClass()); 3152 3153 // And directly continue with the pointee type. 3154 T = MemberPtr->getPointeeType().getTypePtr(); 3155 continue; 3156 } 3157 3158 // As an extension, treat this like a normal pointer. 3159 case Type::BlockPointer: 3160 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr(); 3161 continue; 3162 3163 // References aren't covered by the standard, but that's such an 3164 // obvious defect that we cover them anyway. 3165 case Type::LValueReference: 3166 case Type::RValueReference: 3167 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr(); 3168 continue; 3169 3170 // These are fundamental types. 3171 case Type::Vector: 3172 case Type::ExtVector: 3173 case Type::ConstantMatrix: 3174 case Type::Complex: 3175 case Type::BitInt: 3176 break; 3177 3178 // Non-deduced auto types only get here for error cases. 3179 case Type::Auto: 3180 case Type::DeducedTemplateSpecialization: 3181 break; 3182 3183 // If T is an Objective-C object or interface type, or a pointer to an 3184 // object or interface type, the associated namespace is the global 3185 // namespace. 3186 case Type::ObjCObject: 3187 case Type::ObjCInterface: 3188 case Type::ObjCObjectPointer: 3189 Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl()); 3190 break; 3191 3192 // Atomic types are just wrappers; use the associations of the 3193 // contained type. 3194 case Type::Atomic: 3195 T = cast<AtomicType>(T)->getValueType().getTypePtr(); 3196 continue; 3197 case Type::Pipe: 3198 T = cast<PipeType>(T)->getElementType().getTypePtr(); 3199 continue; 3200 } 3201 3202 if (Queue.empty()) 3203 break; 3204 T = Queue.pop_back_val(); 3205 } 3206 } 3207 3208 /// Find the associated classes and namespaces for 3209 /// argument-dependent lookup for a call with the given set of 3210 /// arguments. 3211 /// 3212 /// This routine computes the sets of associated classes and associated 3213 /// namespaces searched by argument-dependent lookup 3214 /// (C++ [basic.lookup.argdep]) for a given set of arguments. 3215 void Sema::FindAssociatedClassesAndNamespaces( 3216 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args, 3217 AssociatedNamespaceSet &AssociatedNamespaces, 3218 AssociatedClassSet &AssociatedClasses) { 3219 AssociatedNamespaces.clear(); 3220 AssociatedClasses.clear(); 3221 3222 AssociatedLookup Result(*this, InstantiationLoc, 3223 AssociatedNamespaces, AssociatedClasses); 3224 3225 // C++ [basic.lookup.koenig]p2: 3226 // For each argument type T in the function call, there is a set 3227 // of zero or more associated namespaces and a set of zero or more 3228 // associated classes to be considered. The sets of namespaces and 3229 // classes is determined entirely by the types of the function 3230 // arguments (and the namespace of any template template 3231 // argument). 3232 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) { 3233 Expr *Arg = Args[ArgIdx]; 3234 3235 if (Arg->getType() != Context.OverloadTy) { 3236 addAssociatedClassesAndNamespaces(Result, Arg->getType()); 3237 continue; 3238 } 3239 3240 // [...] In addition, if the argument is the name or address of a 3241 // set of overloaded functions and/or function templates, its 3242 // associated classes and namespaces are the union of those 3243 // associated with each of the members of the set: the namespace 3244 // in which the function or function template is defined and the 3245 // classes and namespaces associated with its (non-dependent) 3246 // parameter types and return type. 3247 OverloadExpr *OE = OverloadExpr::find(Arg).Expression; 3248 3249 for (const NamedDecl *D : OE->decls()) { 3250 // Look through any using declarations to find the underlying function. 3251 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction(); 3252 3253 // Add the classes and namespaces associated with the parameter 3254 // types and return type of this function. 3255 addAssociatedClassesAndNamespaces(Result, FDecl->getType()); 3256 } 3257 } 3258 } 3259 3260 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name, 3261 SourceLocation Loc, 3262 LookupNameKind NameKind, 3263 RedeclarationKind Redecl) { 3264 LookupResult R(*this, Name, Loc, NameKind, Redecl); 3265 LookupName(R, S); 3266 return R.getAsSingle<NamedDecl>(); 3267 } 3268 3269 /// Find the protocol with the given name, if any. 3270 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II, 3271 SourceLocation IdLoc, 3272 RedeclarationKind Redecl) { 3273 Decl *D = LookupSingleName(TUScope, II, IdLoc, 3274 LookupObjCProtocolName, Redecl); 3275 return cast_or_null<ObjCProtocolDecl>(D); 3276 } 3277 3278 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, 3279 UnresolvedSetImpl &Functions) { 3280 // C++ [over.match.oper]p3: 3281 // -- The set of non-member candidates is the result of the 3282 // unqualified lookup of operator@ in the context of the 3283 // expression according to the usual rules for name lookup in 3284 // unqualified function calls (3.4.2) except that all member 3285 // functions are ignored. 3286 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3287 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName); 3288 LookupName(Operators, S); 3289 3290 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); 3291 Functions.append(Operators.begin(), Operators.end()); 3292 } 3293 3294 Sema::SpecialMemberOverloadResult Sema::LookupSpecialMember(CXXRecordDecl *RD, 3295 CXXSpecialMember SM, 3296 bool ConstArg, 3297 bool VolatileArg, 3298 bool RValueThis, 3299 bool ConstThis, 3300 bool VolatileThis) { 3301 assert(CanDeclareSpecialMemberFunction(RD) && 3302 "doing special member lookup into record that isn't fully complete"); 3303 RD = RD->getDefinition(); 3304 if (RValueThis || ConstThis || VolatileThis) 3305 assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) && 3306 "constructors and destructors always have unqualified lvalue this"); 3307 if (ConstArg || VolatileArg) 3308 assert((SM != CXXDefaultConstructor && SM != CXXDestructor) && 3309 "parameter-less special members can't have qualified arguments"); 3310 3311 // FIXME: Get the caller to pass in a location for the lookup. 3312 SourceLocation LookupLoc = RD->getLocation(); 3313 3314 llvm::FoldingSetNodeID ID; 3315 ID.AddPointer(RD); 3316 ID.AddInteger(SM); 3317 ID.AddInteger(ConstArg); 3318 ID.AddInteger(VolatileArg); 3319 ID.AddInteger(RValueThis); 3320 ID.AddInteger(ConstThis); 3321 ID.AddInteger(VolatileThis); 3322 3323 void *InsertPoint; 3324 SpecialMemberOverloadResultEntry *Result = 3325 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint); 3326 3327 // This was already cached 3328 if (Result) 3329 return *Result; 3330 3331 Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>(); 3332 Result = new (Result) SpecialMemberOverloadResultEntry(ID); 3333 SpecialMemberCache.InsertNode(Result, InsertPoint); 3334 3335 if (SM == CXXDestructor) { 3336 if (RD->needsImplicitDestructor()) { 3337 runWithSufficientStackSpace(RD->getLocation(), [&] { 3338 DeclareImplicitDestructor(RD); 3339 }); 3340 } 3341 CXXDestructorDecl *DD = RD->getDestructor(); 3342 Result->setMethod(DD); 3343 Result->setKind(DD && !DD->isDeleted() 3344 ? SpecialMemberOverloadResult::Success 3345 : SpecialMemberOverloadResult::NoMemberOrDeleted); 3346 return *Result; 3347 } 3348 3349 // Prepare for overload resolution. Here we construct a synthetic argument 3350 // if necessary and make sure that implicit functions are declared. 3351 CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD)); 3352 DeclarationName Name; 3353 Expr *Arg = nullptr; 3354 unsigned NumArgs; 3355 3356 QualType ArgType = CanTy; 3357 ExprValueKind VK = VK_LValue; 3358 3359 if (SM == CXXDefaultConstructor) { 3360 Name = Context.DeclarationNames.getCXXConstructorName(CanTy); 3361 NumArgs = 0; 3362 if (RD->needsImplicitDefaultConstructor()) { 3363 runWithSufficientStackSpace(RD->getLocation(), [&] { 3364 DeclareImplicitDefaultConstructor(RD); 3365 }); 3366 } 3367 } else { 3368 if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) { 3369 Name = Context.DeclarationNames.getCXXConstructorName(CanTy); 3370 if (RD->needsImplicitCopyConstructor()) { 3371 runWithSufficientStackSpace(RD->getLocation(), [&] { 3372 DeclareImplicitCopyConstructor(RD); 3373 }); 3374 } 3375 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor()) { 3376 runWithSufficientStackSpace(RD->getLocation(), [&] { 3377 DeclareImplicitMoveConstructor(RD); 3378 }); 3379 } 3380 } else { 3381 Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal); 3382 if (RD->needsImplicitCopyAssignment()) { 3383 runWithSufficientStackSpace(RD->getLocation(), [&] { 3384 DeclareImplicitCopyAssignment(RD); 3385 }); 3386 } 3387 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment()) { 3388 runWithSufficientStackSpace(RD->getLocation(), [&] { 3389 DeclareImplicitMoveAssignment(RD); 3390 }); 3391 } 3392 } 3393 3394 if (ConstArg) 3395 ArgType.addConst(); 3396 if (VolatileArg) 3397 ArgType.addVolatile(); 3398 3399 // This isn't /really/ specified by the standard, but it's implied 3400 // we should be working from a PRValue in the case of move to ensure 3401 // that we prefer to bind to rvalue references, and an LValue in the 3402 // case of copy to ensure we don't bind to rvalue references. 3403 // Possibly an XValue is actually correct in the case of move, but 3404 // there is no semantic difference for class types in this restricted 3405 // case. 3406 if (SM == CXXCopyConstructor || SM == CXXCopyAssignment) 3407 VK = VK_LValue; 3408 else 3409 VK = VK_PRValue; 3410 } 3411 3412 OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK); 3413 3414 if (SM != CXXDefaultConstructor) { 3415 NumArgs = 1; 3416 Arg = &FakeArg; 3417 } 3418 3419 // Create the object argument 3420 QualType ThisTy = CanTy; 3421 if (ConstThis) 3422 ThisTy.addConst(); 3423 if (VolatileThis) 3424 ThisTy.addVolatile(); 3425 Expr::Classification Classification = 3426 OpaqueValueExpr(LookupLoc, ThisTy, RValueThis ? VK_PRValue : VK_LValue) 3427 .Classify(Context); 3428 3429 // Now we perform lookup on the name we computed earlier and do overload 3430 // resolution. Lookup is only performed directly into the class since there 3431 // will always be a (possibly implicit) declaration to shadow any others. 3432 OverloadCandidateSet OCS(LookupLoc, OverloadCandidateSet::CSK_Normal); 3433 DeclContext::lookup_result R = RD->lookup(Name); 3434 3435 if (R.empty()) { 3436 // We might have no default constructor because we have a lambda's closure 3437 // type, rather than because there's some other declared constructor. 3438 // Every class has a copy/move constructor, copy/move assignment, and 3439 // destructor. 3440 assert(SM == CXXDefaultConstructor && 3441 "lookup for a constructor or assignment operator was empty"); 3442 Result->setMethod(nullptr); 3443 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 3444 return *Result; 3445 } 3446 3447 // Copy the candidates as our processing of them may load new declarations 3448 // from an external source and invalidate lookup_result. 3449 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end()); 3450 3451 for (NamedDecl *CandDecl : Candidates) { 3452 if (CandDecl->isInvalidDecl()) 3453 continue; 3454 3455 DeclAccessPair Cand = DeclAccessPair::make(CandDecl, AS_public); 3456 auto CtorInfo = getConstructorInfo(Cand); 3457 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl())) { 3458 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) 3459 AddMethodCandidate(M, Cand, RD, ThisTy, Classification, 3460 llvm::makeArrayRef(&Arg, NumArgs), OCS, true); 3461 else if (CtorInfo) 3462 AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl, 3463 llvm::makeArrayRef(&Arg, NumArgs), OCS, 3464 /*SuppressUserConversions*/ true); 3465 else 3466 AddOverloadCandidate(M, Cand, llvm::makeArrayRef(&Arg, NumArgs), OCS, 3467 /*SuppressUserConversions*/ true); 3468 } else if (FunctionTemplateDecl *Tmpl = 3469 dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) { 3470 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) 3471 AddMethodTemplateCandidate( 3472 Tmpl, Cand, RD, nullptr, ThisTy, Classification, 3473 llvm::makeArrayRef(&Arg, NumArgs), OCS, true); 3474 else if (CtorInfo) 3475 AddTemplateOverloadCandidate( 3476 CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr, 3477 llvm::makeArrayRef(&Arg, NumArgs), OCS, true); 3478 else 3479 AddTemplateOverloadCandidate( 3480 Tmpl, Cand, nullptr, llvm::makeArrayRef(&Arg, NumArgs), OCS, true); 3481 } else { 3482 assert(isa<UsingDecl>(Cand.getDecl()) && 3483 "illegal Kind of operator = Decl"); 3484 } 3485 } 3486 3487 OverloadCandidateSet::iterator Best; 3488 switch (OCS.BestViableFunction(*this, LookupLoc, Best)) { 3489 case OR_Success: 3490 Result->setMethod(cast<CXXMethodDecl>(Best->Function)); 3491 Result->setKind(SpecialMemberOverloadResult::Success); 3492 break; 3493 3494 case OR_Deleted: 3495 Result->setMethod(cast<CXXMethodDecl>(Best->Function)); 3496 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 3497 break; 3498 3499 case OR_Ambiguous: 3500 Result->setMethod(nullptr); 3501 Result->setKind(SpecialMemberOverloadResult::Ambiguous); 3502 break; 3503 3504 case OR_No_Viable_Function: 3505 Result->setMethod(nullptr); 3506 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 3507 break; 3508 } 3509 3510 return *Result; 3511 } 3512 3513 /// Look up the default constructor for the given class. 3514 CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) { 3515 SpecialMemberOverloadResult Result = 3516 LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false, 3517 false, false); 3518 3519 return cast_or_null<CXXConstructorDecl>(Result.getMethod()); 3520 } 3521 3522 /// Look up the copying constructor for the given class. 3523 CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class, 3524 unsigned Quals) { 3525 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 3526 "non-const, non-volatile qualifiers for copy ctor arg"); 3527 SpecialMemberOverloadResult Result = 3528 LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const, 3529 Quals & Qualifiers::Volatile, false, false, false); 3530 3531 return cast_or_null<CXXConstructorDecl>(Result.getMethod()); 3532 } 3533 3534 /// Look up the moving constructor for the given class. 3535 CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class, 3536 unsigned Quals) { 3537 SpecialMemberOverloadResult Result = 3538 LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const, 3539 Quals & Qualifiers::Volatile, false, false, false); 3540 3541 return cast_or_null<CXXConstructorDecl>(Result.getMethod()); 3542 } 3543 3544 /// Look up the constructors for the given class. 3545 DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) { 3546 // If the implicit constructors have not yet been declared, do so now. 3547 if (CanDeclareSpecialMemberFunction(Class)) { 3548 runWithSufficientStackSpace(Class->getLocation(), [&] { 3549 if (Class->needsImplicitDefaultConstructor()) 3550 DeclareImplicitDefaultConstructor(Class); 3551 if (Class->needsImplicitCopyConstructor()) 3552 DeclareImplicitCopyConstructor(Class); 3553 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor()) 3554 DeclareImplicitMoveConstructor(Class); 3555 }); 3556 } 3557 3558 CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class)); 3559 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T); 3560 return Class->lookup(Name); 3561 } 3562 3563 /// Look up the copying assignment operator for the given class. 3564 CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class, 3565 unsigned Quals, bool RValueThis, 3566 unsigned ThisQuals) { 3567 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 3568 "non-const, non-volatile qualifiers for copy assignment arg"); 3569 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 3570 "non-const, non-volatile qualifiers for copy assignment this"); 3571 SpecialMemberOverloadResult Result = 3572 LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const, 3573 Quals & Qualifiers::Volatile, RValueThis, 3574 ThisQuals & Qualifiers::Const, 3575 ThisQuals & Qualifiers::Volatile); 3576 3577 return Result.getMethod(); 3578 } 3579 3580 /// Look up the moving assignment operator for the given class. 3581 CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class, 3582 unsigned Quals, 3583 bool RValueThis, 3584 unsigned ThisQuals) { 3585 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 3586 "non-const, non-volatile qualifiers for copy assignment this"); 3587 SpecialMemberOverloadResult Result = 3588 LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const, 3589 Quals & Qualifiers::Volatile, RValueThis, 3590 ThisQuals & Qualifiers::Const, 3591 ThisQuals & Qualifiers::Volatile); 3592 3593 return Result.getMethod(); 3594 } 3595 3596 /// Look for the destructor of the given class. 3597 /// 3598 /// During semantic analysis, this routine should be used in lieu of 3599 /// CXXRecordDecl::getDestructor(). 3600 /// 3601 /// \returns The destructor for this class. 3602 CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) { 3603 return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor, 3604 false, false, false, 3605 false, false).getMethod()); 3606 } 3607 3608 /// LookupLiteralOperator - Determine which literal operator should be used for 3609 /// a user-defined literal, per C++11 [lex.ext]. 3610 /// 3611 /// Normal overload resolution is not used to select which literal operator to 3612 /// call for a user-defined literal. Look up the provided literal operator name, 3613 /// and filter the results to the appropriate set for the given argument types. 3614 Sema::LiteralOperatorLookupResult 3615 Sema::LookupLiteralOperator(Scope *S, LookupResult &R, 3616 ArrayRef<QualType> ArgTys, bool AllowRaw, 3617 bool AllowTemplate, bool AllowStringTemplatePack, 3618 bool DiagnoseMissing, StringLiteral *StringLit) { 3619 LookupName(R, S); 3620 assert(R.getResultKind() != LookupResult::Ambiguous && 3621 "literal operator lookup can't be ambiguous"); 3622 3623 // Filter the lookup results appropriately. 3624 LookupResult::Filter F = R.makeFilter(); 3625 3626 bool AllowCooked = true; 3627 bool FoundRaw = false; 3628 bool FoundTemplate = false; 3629 bool FoundStringTemplatePack = false; 3630 bool FoundCooked = false; 3631 3632 while (F.hasNext()) { 3633 Decl *D = F.next(); 3634 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D)) 3635 D = USD->getTargetDecl(); 3636 3637 // If the declaration we found is invalid, skip it. 3638 if (D->isInvalidDecl()) { 3639 F.erase(); 3640 continue; 3641 } 3642 3643 bool IsRaw = false; 3644 bool IsTemplate = false; 3645 bool IsStringTemplatePack = false; 3646 bool IsCooked = false; 3647 3648 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3649 if (FD->getNumParams() == 1 && 3650 FD->getParamDecl(0)->getType()->getAs<PointerType>()) 3651 IsRaw = true; 3652 else if (FD->getNumParams() == ArgTys.size()) { 3653 IsCooked = true; 3654 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) { 3655 QualType ParamTy = FD->getParamDecl(ArgIdx)->getType(); 3656 if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) { 3657 IsCooked = false; 3658 break; 3659 } 3660 } 3661 } 3662 } 3663 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) { 3664 TemplateParameterList *Params = FD->getTemplateParameters(); 3665 if (Params->size() == 1) { 3666 IsTemplate = true; 3667 if (!Params->getParam(0)->isTemplateParameterPack() && !StringLit) { 3668 // Implied but not stated: user-defined integer and floating literals 3669 // only ever use numeric literal operator templates, not templates 3670 // taking a parameter of class type. 3671 F.erase(); 3672 continue; 3673 } 3674 3675 // A string literal template is only considered if the string literal 3676 // is a well-formed template argument for the template parameter. 3677 if (StringLit) { 3678 SFINAETrap Trap(*this); 3679 SmallVector<TemplateArgument, 1> Checked; 3680 TemplateArgumentLoc Arg(TemplateArgument(StringLit), StringLit); 3681 if (CheckTemplateArgument(Params->getParam(0), Arg, FD, 3682 R.getNameLoc(), R.getNameLoc(), 0, 3683 Checked) || 3684 Trap.hasErrorOccurred()) 3685 IsTemplate = false; 3686 } 3687 } else { 3688 IsStringTemplatePack = true; 3689 } 3690 } 3691 3692 if (AllowTemplate && StringLit && IsTemplate) { 3693 FoundTemplate = true; 3694 AllowRaw = false; 3695 AllowCooked = false; 3696 AllowStringTemplatePack = false; 3697 if (FoundRaw || FoundCooked || FoundStringTemplatePack) { 3698 F.restart(); 3699 FoundRaw = FoundCooked = FoundStringTemplatePack = false; 3700 } 3701 } else if (AllowCooked && IsCooked) { 3702 FoundCooked = true; 3703 AllowRaw = false; 3704 AllowTemplate = StringLit; 3705 AllowStringTemplatePack = false; 3706 if (FoundRaw || FoundTemplate || FoundStringTemplatePack) { 3707 // Go through again and remove the raw and template decls we've 3708 // already found. 3709 F.restart(); 3710 FoundRaw = FoundTemplate = FoundStringTemplatePack = false; 3711 } 3712 } else if (AllowRaw && IsRaw) { 3713 FoundRaw = true; 3714 } else if (AllowTemplate && IsTemplate) { 3715 FoundTemplate = true; 3716 } else if (AllowStringTemplatePack && IsStringTemplatePack) { 3717 FoundStringTemplatePack = true; 3718 } else { 3719 F.erase(); 3720 } 3721 } 3722 3723 F.done(); 3724 3725 // Per C++20 [lex.ext]p5, we prefer the template form over the non-template 3726 // form for string literal operator templates. 3727 if (StringLit && FoundTemplate) 3728 return LOLR_Template; 3729 3730 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching 3731 // parameter type, that is used in preference to a raw literal operator 3732 // or literal operator template. 3733 if (FoundCooked) 3734 return LOLR_Cooked; 3735 3736 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal 3737 // operator template, but not both. 3738 if (FoundRaw && FoundTemplate) { 3739 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName(); 3740 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 3741 NoteOverloadCandidate(*I, (*I)->getUnderlyingDecl()->getAsFunction()); 3742 return LOLR_Error; 3743 } 3744 3745 if (FoundRaw) 3746 return LOLR_Raw; 3747 3748 if (FoundTemplate) 3749 return LOLR_Template; 3750 3751 if (FoundStringTemplatePack) 3752 return LOLR_StringTemplatePack; 3753 3754 // Didn't find anything we could use. 3755 if (DiagnoseMissing) { 3756 Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator) 3757 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0] 3758 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw 3759 << (AllowTemplate || AllowStringTemplatePack); 3760 return LOLR_Error; 3761 } 3762 3763 return LOLR_ErrorNoDiagnostic; 3764 } 3765 3766 void ADLResult::insert(NamedDecl *New) { 3767 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())]; 3768 3769 // If we haven't yet seen a decl for this key, or the last decl 3770 // was exactly this one, we're done. 3771 if (Old == nullptr || Old == New) { 3772 Old = New; 3773 return; 3774 } 3775 3776 // Otherwise, decide which is a more recent redeclaration. 3777 FunctionDecl *OldFD = Old->getAsFunction(); 3778 FunctionDecl *NewFD = New->getAsFunction(); 3779 3780 FunctionDecl *Cursor = NewFD; 3781 while (true) { 3782 Cursor = Cursor->getPreviousDecl(); 3783 3784 // If we got to the end without finding OldFD, OldFD is the newer 3785 // declaration; leave things as they are. 3786 if (!Cursor) return; 3787 3788 // If we do find OldFD, then NewFD is newer. 3789 if (Cursor == OldFD) break; 3790 3791 // Otherwise, keep looking. 3792 } 3793 3794 Old = New; 3795 } 3796 3797 void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc, 3798 ArrayRef<Expr *> Args, ADLResult &Result) { 3799 // Find all of the associated namespaces and classes based on the 3800 // arguments we have. 3801 AssociatedNamespaceSet AssociatedNamespaces; 3802 AssociatedClassSet AssociatedClasses; 3803 FindAssociatedClassesAndNamespaces(Loc, Args, 3804 AssociatedNamespaces, 3805 AssociatedClasses); 3806 3807 // C++ [basic.lookup.argdep]p3: 3808 // Let X be the lookup set produced by unqualified lookup (3.4.1) 3809 // and let Y be the lookup set produced by argument dependent 3810 // lookup (defined as follows). If X contains [...] then Y is 3811 // empty. Otherwise Y is the set of declarations found in the 3812 // namespaces associated with the argument types as described 3813 // below. The set of declarations found by the lookup of the name 3814 // is the union of X and Y. 3815 // 3816 // Here, we compute Y and add its members to the overloaded 3817 // candidate set. 3818 for (auto *NS : AssociatedNamespaces) { 3819 // When considering an associated namespace, the lookup is the 3820 // same as the lookup performed when the associated namespace is 3821 // used as a qualifier (3.4.3.2) except that: 3822 // 3823 // -- Any using-directives in the associated namespace are 3824 // ignored. 3825 // 3826 // -- Any namespace-scope friend functions declared in 3827 // associated classes are visible within their respective 3828 // namespaces even if they are not visible during an ordinary 3829 // lookup (11.4). 3830 DeclContext::lookup_result R = NS->lookup(Name); 3831 for (auto *D : R) { 3832 auto *Underlying = D; 3833 if (auto *USD = dyn_cast<UsingShadowDecl>(D)) 3834 Underlying = USD->getTargetDecl(); 3835 3836 if (!isa<FunctionDecl>(Underlying) && 3837 !isa<FunctionTemplateDecl>(Underlying)) 3838 continue; 3839 3840 // The declaration is visible to argument-dependent lookup if either 3841 // it's ordinarily visible or declared as a friend in an associated 3842 // class. 3843 bool Visible = false; 3844 for (D = D->getMostRecentDecl(); D; 3845 D = cast_or_null<NamedDecl>(D->getPreviousDecl())) { 3846 if (D->getIdentifierNamespace() & Decl::IDNS_Ordinary) { 3847 if (isVisible(D)) { 3848 Visible = true; 3849 break; 3850 } 3851 } else if (D->getFriendObjectKind()) { 3852 auto *RD = cast<CXXRecordDecl>(D->getLexicalDeclContext()); 3853 // [basic.lookup.argdep]p4: 3854 // Argument-dependent lookup finds all declarations of functions and 3855 // function templates that 3856 // - ... 3857 // - are declared as a friend ([class.friend]) of any class with a 3858 // reachable definition in the set of associated entities, 3859 // 3860 // FIXME: If there's a merged definition of D that is reachable, then 3861 // the friend declaration should be considered. 3862 if (AssociatedClasses.count(RD) && isReachable(D)) { 3863 Visible = true; 3864 break; 3865 } 3866 } 3867 } 3868 3869 // FIXME: Preserve D as the FoundDecl. 3870 if (Visible) 3871 Result.insert(Underlying); 3872 } 3873 } 3874 } 3875 3876 //---------------------------------------------------------------------------- 3877 // Search for all visible declarations. 3878 //---------------------------------------------------------------------------- 3879 VisibleDeclConsumer::~VisibleDeclConsumer() { } 3880 3881 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; } 3882 3883 namespace { 3884 3885 class ShadowContextRAII; 3886 3887 class VisibleDeclsRecord { 3888 public: 3889 /// An entry in the shadow map, which is optimized to store a 3890 /// single declaration (the common case) but can also store a list 3891 /// of declarations. 3892 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry; 3893 3894 private: 3895 /// A mapping from declaration names to the declarations that have 3896 /// this name within a particular scope. 3897 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap; 3898 3899 /// A list of shadow maps, which is used to model name hiding. 3900 std::list<ShadowMap> ShadowMaps; 3901 3902 /// The declaration contexts we have already visited. 3903 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts; 3904 3905 friend class ShadowContextRAII; 3906 3907 public: 3908 /// Determine whether we have already visited this context 3909 /// (and, if not, note that we are going to visit that context now). 3910 bool visitedContext(DeclContext *Ctx) { 3911 return !VisitedContexts.insert(Ctx).second; 3912 } 3913 3914 bool alreadyVisitedContext(DeclContext *Ctx) { 3915 return VisitedContexts.count(Ctx); 3916 } 3917 3918 /// Determine whether the given declaration is hidden in the 3919 /// current scope. 3920 /// 3921 /// \returns the declaration that hides the given declaration, or 3922 /// NULL if no such declaration exists. 3923 NamedDecl *checkHidden(NamedDecl *ND); 3924 3925 /// Add a declaration to the current shadow map. 3926 void add(NamedDecl *ND) { 3927 ShadowMaps.back()[ND->getDeclName()].push_back(ND); 3928 } 3929 }; 3930 3931 /// RAII object that records when we've entered a shadow context. 3932 class ShadowContextRAII { 3933 VisibleDeclsRecord &Visible; 3934 3935 typedef VisibleDeclsRecord::ShadowMap ShadowMap; 3936 3937 public: 3938 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) { 3939 Visible.ShadowMaps.emplace_back(); 3940 } 3941 3942 ~ShadowContextRAII() { 3943 Visible.ShadowMaps.pop_back(); 3944 } 3945 }; 3946 3947 } // end anonymous namespace 3948 3949 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) { 3950 unsigned IDNS = ND->getIdentifierNamespace(); 3951 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin(); 3952 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend(); 3953 SM != SMEnd; ++SM) { 3954 ShadowMap::iterator Pos = SM->find(ND->getDeclName()); 3955 if (Pos == SM->end()) 3956 continue; 3957 3958 for (auto *D : Pos->second) { 3959 // A tag declaration does not hide a non-tag declaration. 3960 if (D->hasTagIdentifierNamespace() && 3961 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary | 3962 Decl::IDNS_ObjCProtocol))) 3963 continue; 3964 3965 // Protocols are in distinct namespaces from everything else. 3966 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol) 3967 || (IDNS & Decl::IDNS_ObjCProtocol)) && 3968 D->getIdentifierNamespace() != IDNS) 3969 continue; 3970 3971 // Functions and function templates in the same scope overload 3972 // rather than hide. FIXME: Look for hiding based on function 3973 // signatures! 3974 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() && 3975 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() && 3976 SM == ShadowMaps.rbegin()) 3977 continue; 3978 3979 // A shadow declaration that's created by a resolved using declaration 3980 // is not hidden by the same using declaration. 3981 if (isa<UsingShadowDecl>(ND) && isa<UsingDecl>(D) && 3982 cast<UsingShadowDecl>(ND)->getIntroducer() == D) 3983 continue; 3984 3985 // We've found a declaration that hides this one. 3986 return D; 3987 } 3988 } 3989 3990 return nullptr; 3991 } 3992 3993 namespace { 3994 class LookupVisibleHelper { 3995 public: 3996 LookupVisibleHelper(VisibleDeclConsumer &Consumer, bool IncludeDependentBases, 3997 bool LoadExternal) 3998 : Consumer(Consumer), IncludeDependentBases(IncludeDependentBases), 3999 LoadExternal(LoadExternal) {} 4000 4001 void lookupVisibleDecls(Sema &SemaRef, Scope *S, Sema::LookupNameKind Kind, 4002 bool IncludeGlobalScope) { 4003 // Determine the set of using directives available during 4004 // unqualified name lookup. 4005 Scope *Initial = S; 4006 UnqualUsingDirectiveSet UDirs(SemaRef); 4007 if (SemaRef.getLangOpts().CPlusPlus) { 4008 // Find the first namespace or translation-unit scope. 4009 while (S && !isNamespaceOrTranslationUnitScope(S)) 4010 S = S->getParent(); 4011 4012 UDirs.visitScopeChain(Initial, S); 4013 } 4014 UDirs.done(); 4015 4016 // Look for visible declarations. 4017 LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind); 4018 Result.setAllowHidden(Consumer.includeHiddenDecls()); 4019 if (!IncludeGlobalScope) 4020 Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl()); 4021 ShadowContextRAII Shadow(Visited); 4022 lookupInScope(Initial, Result, UDirs); 4023 } 4024 4025 void lookupVisibleDecls(Sema &SemaRef, DeclContext *Ctx, 4026 Sema::LookupNameKind Kind, bool IncludeGlobalScope) { 4027 LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind); 4028 Result.setAllowHidden(Consumer.includeHiddenDecls()); 4029 if (!IncludeGlobalScope) 4030 Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl()); 4031 4032 ShadowContextRAII Shadow(Visited); 4033 lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/true, 4034 /*InBaseClass=*/false); 4035 } 4036 4037 private: 4038 void lookupInDeclContext(DeclContext *Ctx, LookupResult &Result, 4039 bool QualifiedNameLookup, bool InBaseClass) { 4040 if (!Ctx) 4041 return; 4042 4043 // Make sure we don't visit the same context twice. 4044 if (Visited.visitedContext(Ctx->getPrimaryContext())) 4045 return; 4046 4047 Consumer.EnteredContext(Ctx); 4048 4049 // Outside C++, lookup results for the TU live on identifiers. 4050 if (isa<TranslationUnitDecl>(Ctx) && 4051 !Result.getSema().getLangOpts().CPlusPlus) { 4052 auto &S = Result.getSema(); 4053 auto &Idents = S.Context.Idents; 4054 4055 // Ensure all external identifiers are in the identifier table. 4056 if (LoadExternal) 4057 if (IdentifierInfoLookup *External = 4058 Idents.getExternalIdentifierLookup()) { 4059 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers()); 4060 for (StringRef Name = Iter->Next(); !Name.empty(); 4061 Name = Iter->Next()) 4062 Idents.get(Name); 4063 } 4064 4065 // Walk all lookup results in the TU for each identifier. 4066 for (const auto &Ident : Idents) { 4067 for (auto I = S.IdResolver.begin(Ident.getValue()), 4068 E = S.IdResolver.end(); 4069 I != E; ++I) { 4070 if (S.IdResolver.isDeclInScope(*I, Ctx)) { 4071 if (NamedDecl *ND = Result.getAcceptableDecl(*I)) { 4072 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass); 4073 Visited.add(ND); 4074 } 4075 } 4076 } 4077 } 4078 4079 return; 4080 } 4081 4082 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx)) 4083 Result.getSema().ForceDeclarationOfImplicitMembers(Class); 4084 4085 llvm::SmallVector<NamedDecl *, 4> DeclsToVisit; 4086 // We sometimes skip loading namespace-level results (they tend to be huge). 4087 bool Load = LoadExternal || 4088 !(isa<TranslationUnitDecl>(Ctx) || isa<NamespaceDecl>(Ctx)); 4089 // Enumerate all of the results in this context. 4090 for (DeclContextLookupResult R : 4091 Load ? Ctx->lookups() 4092 : Ctx->noload_lookups(/*PreserveInternalState=*/false)) { 4093 for (auto *D : R) { 4094 if (auto *ND = Result.getAcceptableDecl(D)) { 4095 // Rather than visit immediately, we put ND into a vector and visit 4096 // all decls, in order, outside of this loop. The reason is that 4097 // Consumer.FoundDecl() may invalidate the iterators used in the two 4098 // loops above. 4099 DeclsToVisit.push_back(ND); 4100 } 4101 } 4102 } 4103 4104 for (auto *ND : DeclsToVisit) { 4105 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass); 4106 Visited.add(ND); 4107 } 4108 DeclsToVisit.clear(); 4109 4110 // Traverse using directives for qualified name lookup. 4111 if (QualifiedNameLookup) { 4112 ShadowContextRAII Shadow(Visited); 4113 for (auto I : Ctx->using_directives()) { 4114 if (!Result.getSema().isVisible(I)) 4115 continue; 4116 lookupInDeclContext(I->getNominatedNamespace(), Result, 4117 QualifiedNameLookup, InBaseClass); 4118 } 4119 } 4120 4121 // Traverse the contexts of inherited C++ classes. 4122 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) { 4123 if (!Record->hasDefinition()) 4124 return; 4125 4126 for (const auto &B : Record->bases()) { 4127 QualType BaseType = B.getType(); 4128 4129 RecordDecl *RD; 4130 if (BaseType->isDependentType()) { 4131 if (!IncludeDependentBases) { 4132 // Don't look into dependent bases, because name lookup can't look 4133 // there anyway. 4134 continue; 4135 } 4136 const auto *TST = BaseType->getAs<TemplateSpecializationType>(); 4137 if (!TST) 4138 continue; 4139 TemplateName TN = TST->getTemplateName(); 4140 const auto *TD = 4141 dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl()); 4142 if (!TD) 4143 continue; 4144 RD = TD->getTemplatedDecl(); 4145 } else { 4146 const auto *Record = BaseType->getAs<RecordType>(); 4147 if (!Record) 4148 continue; 4149 RD = Record->getDecl(); 4150 } 4151 4152 // FIXME: It would be nice to be able to determine whether referencing 4153 // a particular member would be ambiguous. For example, given 4154 // 4155 // struct A { int member; }; 4156 // struct B { int member; }; 4157 // struct C : A, B { }; 4158 // 4159 // void f(C *c) { c->### } 4160 // 4161 // accessing 'member' would result in an ambiguity. However, we 4162 // could be smart enough to qualify the member with the base 4163 // class, e.g., 4164 // 4165 // c->B::member 4166 // 4167 // or 4168 // 4169 // c->A::member 4170 4171 // Find results in this base class (and its bases). 4172 ShadowContextRAII Shadow(Visited); 4173 lookupInDeclContext(RD, Result, QualifiedNameLookup, 4174 /*InBaseClass=*/true); 4175 } 4176 } 4177 4178 // Traverse the contexts of Objective-C classes. 4179 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) { 4180 // Traverse categories. 4181 for (auto *Cat : IFace->visible_categories()) { 4182 ShadowContextRAII Shadow(Visited); 4183 lookupInDeclContext(Cat, Result, QualifiedNameLookup, 4184 /*InBaseClass=*/false); 4185 } 4186 4187 // Traverse protocols. 4188 for (auto *I : IFace->all_referenced_protocols()) { 4189 ShadowContextRAII Shadow(Visited); 4190 lookupInDeclContext(I, Result, QualifiedNameLookup, 4191 /*InBaseClass=*/false); 4192 } 4193 4194 // Traverse the superclass. 4195 if (IFace->getSuperClass()) { 4196 ShadowContextRAII Shadow(Visited); 4197 lookupInDeclContext(IFace->getSuperClass(), Result, QualifiedNameLookup, 4198 /*InBaseClass=*/true); 4199 } 4200 4201 // If there is an implementation, traverse it. We do this to find 4202 // synthesized ivars. 4203 if (IFace->getImplementation()) { 4204 ShadowContextRAII Shadow(Visited); 4205 lookupInDeclContext(IFace->getImplementation(), Result, 4206 QualifiedNameLookup, InBaseClass); 4207 } 4208 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) { 4209 for (auto *I : Protocol->protocols()) { 4210 ShadowContextRAII Shadow(Visited); 4211 lookupInDeclContext(I, Result, QualifiedNameLookup, 4212 /*InBaseClass=*/false); 4213 } 4214 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) { 4215 for (auto *I : Category->protocols()) { 4216 ShadowContextRAII Shadow(Visited); 4217 lookupInDeclContext(I, Result, QualifiedNameLookup, 4218 /*InBaseClass=*/false); 4219 } 4220 4221 // If there is an implementation, traverse it. 4222 if (Category->getImplementation()) { 4223 ShadowContextRAII Shadow(Visited); 4224 lookupInDeclContext(Category->getImplementation(), Result, 4225 QualifiedNameLookup, /*InBaseClass=*/true); 4226 } 4227 } 4228 } 4229 4230 void lookupInScope(Scope *S, LookupResult &Result, 4231 UnqualUsingDirectiveSet &UDirs) { 4232 // No clients run in this mode and it's not supported. Please add tests and 4233 // remove the assertion if you start relying on it. 4234 assert(!IncludeDependentBases && "Unsupported flag for lookupInScope"); 4235 4236 if (!S) 4237 return; 4238 4239 if (!S->getEntity() || 4240 (!S->getParent() && !Visited.alreadyVisitedContext(S->getEntity())) || 4241 (S->getEntity())->isFunctionOrMethod()) { 4242 FindLocalExternScope FindLocals(Result); 4243 // Walk through the declarations in this Scope. The consumer might add new 4244 // decls to the scope as part of deserialization, so make a copy first. 4245 SmallVector<Decl *, 8> ScopeDecls(S->decls().begin(), S->decls().end()); 4246 for (Decl *D : ScopeDecls) { 4247 if (NamedDecl *ND = dyn_cast<NamedDecl>(D)) 4248 if ((ND = Result.getAcceptableDecl(ND))) { 4249 Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false); 4250 Visited.add(ND); 4251 } 4252 } 4253 } 4254 4255 DeclContext *Entity = S->getLookupEntity(); 4256 if (Entity) { 4257 // Look into this scope's declaration context, along with any of its 4258 // parent lookup contexts (e.g., enclosing classes), up to the point 4259 // where we hit the context stored in the next outer scope. 4260 DeclContext *OuterCtx = findOuterContext(S); 4261 4262 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx); 4263 Ctx = Ctx->getLookupParent()) { 4264 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 4265 if (Method->isInstanceMethod()) { 4266 // For instance methods, look for ivars in the method's interface. 4267 LookupResult IvarResult(Result.getSema(), Result.getLookupName(), 4268 Result.getNameLoc(), 4269 Sema::LookupMemberName); 4270 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) { 4271 lookupInDeclContext(IFace, IvarResult, 4272 /*QualifiedNameLookup=*/false, 4273 /*InBaseClass=*/false); 4274 } 4275 } 4276 4277 // We've already performed all of the name lookup that we need 4278 // to for Objective-C methods; the next context will be the 4279 // outer scope. 4280 break; 4281 } 4282 4283 if (Ctx->isFunctionOrMethod()) 4284 continue; 4285 4286 lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/false, 4287 /*InBaseClass=*/false); 4288 } 4289 } else if (!S->getParent()) { 4290 // Look into the translation unit scope. We walk through the translation 4291 // unit's declaration context, because the Scope itself won't have all of 4292 // the declarations if we loaded a precompiled header. 4293 // FIXME: We would like the translation unit's Scope object to point to 4294 // the translation unit, so we don't need this special "if" branch. 4295 // However, doing so would force the normal C++ name-lookup code to look 4296 // into the translation unit decl when the IdentifierInfo chains would 4297 // suffice. Once we fix that problem (which is part of a more general 4298 // "don't look in DeclContexts unless we have to" optimization), we can 4299 // eliminate this. 4300 Entity = Result.getSema().Context.getTranslationUnitDecl(); 4301 lookupInDeclContext(Entity, Result, /*QualifiedNameLookup=*/false, 4302 /*InBaseClass=*/false); 4303 } 4304 4305 if (Entity) { 4306 // Lookup visible declarations in any namespaces found by using 4307 // directives. 4308 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity)) 4309 lookupInDeclContext( 4310 const_cast<DeclContext *>(UUE.getNominatedNamespace()), Result, 4311 /*QualifiedNameLookup=*/false, 4312 /*InBaseClass=*/false); 4313 } 4314 4315 // Lookup names in the parent scope. 4316 ShadowContextRAII Shadow(Visited); 4317 lookupInScope(S->getParent(), Result, UDirs); 4318 } 4319 4320 private: 4321 VisibleDeclsRecord Visited; 4322 VisibleDeclConsumer &Consumer; 4323 bool IncludeDependentBases; 4324 bool LoadExternal; 4325 }; 4326 } // namespace 4327 4328 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind, 4329 VisibleDeclConsumer &Consumer, 4330 bool IncludeGlobalScope, bool LoadExternal) { 4331 LookupVisibleHelper H(Consumer, /*IncludeDependentBases=*/false, 4332 LoadExternal); 4333 H.lookupVisibleDecls(*this, S, Kind, IncludeGlobalScope); 4334 } 4335 4336 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind, 4337 VisibleDeclConsumer &Consumer, 4338 bool IncludeGlobalScope, 4339 bool IncludeDependentBases, bool LoadExternal) { 4340 LookupVisibleHelper H(Consumer, IncludeDependentBases, LoadExternal); 4341 H.lookupVisibleDecls(*this, Ctx, Kind, IncludeGlobalScope); 4342 } 4343 4344 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name. 4345 /// If GnuLabelLoc is a valid source location, then this is a definition 4346 /// of an __label__ label name, otherwise it is a normal label definition 4347 /// or use. 4348 LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc, 4349 SourceLocation GnuLabelLoc) { 4350 // Do a lookup to see if we have a label with this name already. 4351 NamedDecl *Res = nullptr; 4352 4353 if (GnuLabelLoc.isValid()) { 4354 // Local label definitions always shadow existing labels. 4355 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc); 4356 Scope *S = CurScope; 4357 PushOnScopeChains(Res, S, true); 4358 return cast<LabelDecl>(Res); 4359 } 4360 4361 // Not a GNU local label. 4362 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration); 4363 // If we found a label, check to see if it is in the same context as us. 4364 // When in a Block, we don't want to reuse a label in an enclosing function. 4365 if (Res && Res->getDeclContext() != CurContext) 4366 Res = nullptr; 4367 if (!Res) { 4368 // If not forward referenced or defined already, create the backing decl. 4369 Res = LabelDecl::Create(Context, CurContext, Loc, II); 4370 Scope *S = CurScope->getFnParent(); 4371 assert(S && "Not in a function?"); 4372 PushOnScopeChains(Res, S, true); 4373 } 4374 return cast<LabelDecl>(Res); 4375 } 4376 4377 //===----------------------------------------------------------------------===// 4378 // Typo correction 4379 //===----------------------------------------------------------------------===// 4380 4381 static bool isCandidateViable(CorrectionCandidateCallback &CCC, 4382 TypoCorrection &Candidate) { 4383 Candidate.setCallbackDistance(CCC.RankCandidate(Candidate)); 4384 return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance; 4385 } 4386 4387 static void LookupPotentialTypoResult(Sema &SemaRef, 4388 LookupResult &Res, 4389 IdentifierInfo *Name, 4390 Scope *S, CXXScopeSpec *SS, 4391 DeclContext *MemberContext, 4392 bool EnteringContext, 4393 bool isObjCIvarLookup, 4394 bool FindHidden); 4395 4396 /// Check whether the declarations found for a typo correction are 4397 /// visible. Set the correction's RequiresImport flag to true if none of the 4398 /// declarations are visible, false otherwise. 4399 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) { 4400 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end(); 4401 4402 for (/**/; DI != DE; ++DI) 4403 if (!LookupResult::isVisible(SemaRef, *DI)) 4404 break; 4405 // No filtering needed if all decls are visible. 4406 if (DI == DE) { 4407 TC.setRequiresImport(false); 4408 return; 4409 } 4410 4411 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI); 4412 bool AnyVisibleDecls = !NewDecls.empty(); 4413 4414 for (/**/; DI != DE; ++DI) { 4415 if (LookupResult::isVisible(SemaRef, *DI)) { 4416 if (!AnyVisibleDecls) { 4417 // Found a visible decl, discard all hidden ones. 4418 AnyVisibleDecls = true; 4419 NewDecls.clear(); 4420 } 4421 NewDecls.push_back(*DI); 4422 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate()) 4423 NewDecls.push_back(*DI); 4424 } 4425 4426 if (NewDecls.empty()) 4427 TC = TypoCorrection(); 4428 else { 4429 TC.setCorrectionDecls(NewDecls); 4430 TC.setRequiresImport(!AnyVisibleDecls); 4431 } 4432 } 4433 4434 // Fill the supplied vector with the IdentifierInfo pointers for each piece of 4435 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::", 4436 // fill the vector with the IdentifierInfo pointers for "foo" and "bar"). 4437 static void getNestedNameSpecifierIdentifiers( 4438 NestedNameSpecifier *NNS, 4439 SmallVectorImpl<const IdentifierInfo*> &Identifiers) { 4440 if (NestedNameSpecifier *Prefix = NNS->getPrefix()) 4441 getNestedNameSpecifierIdentifiers(Prefix, Identifiers); 4442 else 4443 Identifiers.clear(); 4444 4445 const IdentifierInfo *II = nullptr; 4446 4447 switch (NNS->getKind()) { 4448 case NestedNameSpecifier::Identifier: 4449 II = NNS->getAsIdentifier(); 4450 break; 4451 4452 case NestedNameSpecifier::Namespace: 4453 if (NNS->getAsNamespace()->isAnonymousNamespace()) 4454 return; 4455 II = NNS->getAsNamespace()->getIdentifier(); 4456 break; 4457 4458 case NestedNameSpecifier::NamespaceAlias: 4459 II = NNS->getAsNamespaceAlias()->getIdentifier(); 4460 break; 4461 4462 case NestedNameSpecifier::TypeSpecWithTemplate: 4463 case NestedNameSpecifier::TypeSpec: 4464 II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier(); 4465 break; 4466 4467 case NestedNameSpecifier::Global: 4468 case NestedNameSpecifier::Super: 4469 return; 4470 } 4471 4472 if (II) 4473 Identifiers.push_back(II); 4474 } 4475 4476 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding, 4477 DeclContext *Ctx, bool InBaseClass) { 4478 // Don't consider hidden names for typo correction. 4479 if (Hiding) 4480 return; 4481 4482 // Only consider entities with identifiers for names, ignoring 4483 // special names (constructors, overloaded operators, selectors, 4484 // etc.). 4485 IdentifierInfo *Name = ND->getIdentifier(); 4486 if (!Name) 4487 return; 4488 4489 // Only consider visible declarations and declarations from modules with 4490 // names that exactly match. 4491 if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo) 4492 return; 4493 4494 FoundName(Name->getName()); 4495 } 4496 4497 void TypoCorrectionConsumer::FoundName(StringRef Name) { 4498 // Compute the edit distance between the typo and the name of this 4499 // entity, and add the identifier to the list of results. 4500 addName(Name, nullptr); 4501 } 4502 4503 void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) { 4504 // Compute the edit distance between the typo and this keyword, 4505 // and add the keyword to the list of results. 4506 addName(Keyword, nullptr, nullptr, true); 4507 } 4508 4509 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND, 4510 NestedNameSpecifier *NNS, bool isKeyword) { 4511 // Use a simple length-based heuristic to determine the minimum possible 4512 // edit distance. If the minimum isn't good enough, bail out early. 4513 StringRef TypoStr = Typo->getName(); 4514 unsigned MinED = abs((int)Name.size() - (int)TypoStr.size()); 4515 if (MinED && TypoStr.size() / MinED < 3) 4516 return; 4517 4518 // Compute an upper bound on the allowable edit distance, so that the 4519 // edit-distance algorithm can short-circuit. 4520 unsigned UpperBound = (TypoStr.size() + 2) / 3; 4521 unsigned ED = TypoStr.edit_distance(Name, true, UpperBound); 4522 if (ED > UpperBound) return; 4523 4524 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED); 4525 if (isKeyword) TC.makeKeyword(); 4526 TC.setCorrectionRange(nullptr, Result.getLookupNameInfo()); 4527 addCorrection(TC); 4528 } 4529 4530 static const unsigned MaxTypoDistanceResultSets = 5; 4531 4532 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) { 4533 StringRef TypoStr = Typo->getName(); 4534 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName(); 4535 4536 // For very short typos, ignore potential corrections that have a different 4537 // base identifier from the typo or which have a normalized edit distance 4538 // longer than the typo itself. 4539 if (TypoStr.size() < 3 && 4540 (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size())) 4541 return; 4542 4543 // If the correction is resolved but is not viable, ignore it. 4544 if (Correction.isResolved()) { 4545 checkCorrectionVisibility(SemaRef, Correction); 4546 if (!Correction || !isCandidateViable(*CorrectionValidator, Correction)) 4547 return; 4548 } 4549 4550 TypoResultList &CList = 4551 CorrectionResults[Correction.getEditDistance(false)][Name]; 4552 4553 if (!CList.empty() && !CList.back().isResolved()) 4554 CList.pop_back(); 4555 if (NamedDecl *NewND = Correction.getCorrectionDecl()) { 4556 auto RI = llvm::find_if(CList, [NewND](const TypoCorrection &TypoCorr) { 4557 return TypoCorr.getCorrectionDecl() == NewND; 4558 }); 4559 if (RI != CList.end()) { 4560 // The Correction refers to a decl already in the list. No insertion is 4561 // necessary and all further cases will return. 4562 4563 auto IsDeprecated = [](Decl *D) { 4564 while (D) { 4565 if (D->isDeprecated()) 4566 return true; 4567 D = llvm::dyn_cast_or_null<NamespaceDecl>(D->getDeclContext()); 4568 } 4569 return false; 4570 }; 4571 4572 // Prefer non deprecated Corrections over deprecated and only then 4573 // sort using an alphabetical order. 4574 std::pair<bool, std::string> NewKey = { 4575 IsDeprecated(Correction.getFoundDecl()), 4576 Correction.getAsString(SemaRef.getLangOpts())}; 4577 4578 std::pair<bool, std::string> PrevKey = { 4579 IsDeprecated(RI->getFoundDecl()), 4580 RI->getAsString(SemaRef.getLangOpts())}; 4581 4582 if (NewKey < PrevKey) 4583 *RI = Correction; 4584 return; 4585 } 4586 } 4587 if (CList.empty() || Correction.isResolved()) 4588 CList.push_back(Correction); 4589 4590 while (CorrectionResults.size() > MaxTypoDistanceResultSets) 4591 CorrectionResults.erase(std::prev(CorrectionResults.end())); 4592 } 4593 4594 void TypoCorrectionConsumer::addNamespaces( 4595 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) { 4596 SearchNamespaces = true; 4597 4598 for (auto KNPair : KnownNamespaces) 4599 Namespaces.addNameSpecifier(KNPair.first); 4600 4601 bool SSIsTemplate = false; 4602 if (NestedNameSpecifier *NNS = 4603 (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) { 4604 if (const Type *T = NNS->getAsType()) 4605 SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization; 4606 } 4607 // Do not transform this into an iterator-based loop. The loop body can 4608 // trigger the creation of further types (through lazy deserialization) and 4609 // invalid iterators into this list. 4610 auto &Types = SemaRef.getASTContext().getTypes(); 4611 for (unsigned I = 0; I != Types.size(); ++I) { 4612 const auto *TI = Types[I]; 4613 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) { 4614 CD = CD->getCanonicalDecl(); 4615 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() && 4616 !CD->isUnion() && CD->getIdentifier() && 4617 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) && 4618 (CD->isBeingDefined() || CD->isCompleteDefinition())) 4619 Namespaces.addNameSpecifier(CD); 4620 } 4621 } 4622 } 4623 4624 const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() { 4625 if (++CurrentTCIndex < ValidatedCorrections.size()) 4626 return ValidatedCorrections[CurrentTCIndex]; 4627 4628 CurrentTCIndex = ValidatedCorrections.size(); 4629 while (!CorrectionResults.empty()) { 4630 auto DI = CorrectionResults.begin(); 4631 if (DI->second.empty()) { 4632 CorrectionResults.erase(DI); 4633 continue; 4634 } 4635 4636 auto RI = DI->second.begin(); 4637 if (RI->second.empty()) { 4638 DI->second.erase(RI); 4639 performQualifiedLookups(); 4640 continue; 4641 } 4642 4643 TypoCorrection TC = RI->second.pop_back_val(); 4644 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) { 4645 ValidatedCorrections.push_back(TC); 4646 return ValidatedCorrections[CurrentTCIndex]; 4647 } 4648 } 4649 return ValidatedCorrections[0]; // The empty correction. 4650 } 4651 4652 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) { 4653 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo(); 4654 DeclContext *TempMemberContext = MemberContext; 4655 CXXScopeSpec *TempSS = SS.get(); 4656 retry_lookup: 4657 LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext, 4658 EnteringContext, 4659 CorrectionValidator->IsObjCIvarLookup, 4660 Name == Typo && !Candidate.WillReplaceSpecifier()); 4661 switch (Result.getResultKind()) { 4662 case LookupResult::NotFound: 4663 case LookupResult::NotFoundInCurrentInstantiation: 4664 case LookupResult::FoundUnresolvedValue: 4665 if (TempSS) { 4666 // Immediately retry the lookup without the given CXXScopeSpec 4667 TempSS = nullptr; 4668 Candidate.WillReplaceSpecifier(true); 4669 goto retry_lookup; 4670 } 4671 if (TempMemberContext) { 4672 if (SS && !TempSS) 4673 TempSS = SS.get(); 4674 TempMemberContext = nullptr; 4675 goto retry_lookup; 4676 } 4677 if (SearchNamespaces) 4678 QualifiedResults.push_back(Candidate); 4679 break; 4680 4681 case LookupResult::Ambiguous: 4682 // We don't deal with ambiguities. 4683 break; 4684 4685 case LookupResult::Found: 4686 case LookupResult::FoundOverloaded: 4687 // Store all of the Decls for overloaded symbols 4688 for (auto *TRD : Result) 4689 Candidate.addCorrectionDecl(TRD); 4690 checkCorrectionVisibility(SemaRef, Candidate); 4691 if (!isCandidateViable(*CorrectionValidator, Candidate)) { 4692 if (SearchNamespaces) 4693 QualifiedResults.push_back(Candidate); 4694 break; 4695 } 4696 Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo()); 4697 return true; 4698 } 4699 return false; 4700 } 4701 4702 void TypoCorrectionConsumer::performQualifiedLookups() { 4703 unsigned TypoLen = Typo->getName().size(); 4704 for (const TypoCorrection &QR : QualifiedResults) { 4705 for (const auto &NSI : Namespaces) { 4706 DeclContext *Ctx = NSI.DeclCtx; 4707 const Type *NSType = NSI.NameSpecifier->getAsType(); 4708 4709 // If the current NestedNameSpecifier refers to a class and the 4710 // current correction candidate is the name of that class, then skip 4711 // it as it is unlikely a qualified version of the class' constructor 4712 // is an appropriate correction. 4713 if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() : 4714 nullptr) { 4715 if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo()) 4716 continue; 4717 } 4718 4719 TypoCorrection TC(QR); 4720 TC.ClearCorrectionDecls(); 4721 TC.setCorrectionSpecifier(NSI.NameSpecifier); 4722 TC.setQualifierDistance(NSI.EditDistance); 4723 TC.setCallbackDistance(0); // Reset the callback distance 4724 4725 // If the current correction candidate and namespace combination are 4726 // too far away from the original typo based on the normalized edit 4727 // distance, then skip performing a qualified name lookup. 4728 unsigned TmpED = TC.getEditDistance(true); 4729 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED && 4730 TypoLen / TmpED < 3) 4731 continue; 4732 4733 Result.clear(); 4734 Result.setLookupName(QR.getCorrectionAsIdentifierInfo()); 4735 if (!SemaRef.LookupQualifiedName(Result, Ctx)) 4736 continue; 4737 4738 // Any corrections added below will be validated in subsequent 4739 // iterations of the main while() loop over the Consumer's contents. 4740 switch (Result.getResultKind()) { 4741 case LookupResult::Found: 4742 case LookupResult::FoundOverloaded: { 4743 if (SS && SS->isValid()) { 4744 std::string NewQualified = TC.getAsString(SemaRef.getLangOpts()); 4745 std::string OldQualified; 4746 llvm::raw_string_ostream OldOStream(OldQualified); 4747 SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy()); 4748 OldOStream << Typo->getName(); 4749 // If correction candidate would be an identical written qualified 4750 // identifier, then the existing CXXScopeSpec probably included a 4751 // typedef that didn't get accounted for properly. 4752 if (OldOStream.str() == NewQualified) 4753 break; 4754 } 4755 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end(); 4756 TRD != TRDEnd; ++TRD) { 4757 if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(), 4758 NSType ? NSType->getAsCXXRecordDecl() 4759 : nullptr, 4760 TRD.getPair()) == Sema::AR_accessible) 4761 TC.addCorrectionDecl(*TRD); 4762 } 4763 if (TC.isResolved()) { 4764 TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo()); 4765 addCorrection(TC); 4766 } 4767 break; 4768 } 4769 case LookupResult::NotFound: 4770 case LookupResult::NotFoundInCurrentInstantiation: 4771 case LookupResult::Ambiguous: 4772 case LookupResult::FoundUnresolvedValue: 4773 break; 4774 } 4775 } 4776 } 4777 QualifiedResults.clear(); 4778 } 4779 4780 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet( 4781 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec) 4782 : Context(Context), CurContextChain(buildContextChain(CurContext)) { 4783 if (NestedNameSpecifier *NNS = 4784 CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) { 4785 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier); 4786 NNS->print(SpecifierOStream, Context.getPrintingPolicy()); 4787 4788 getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers); 4789 } 4790 // Build the list of identifiers that would be used for an absolute 4791 // (from the global context) NestedNameSpecifier referring to the current 4792 // context. 4793 for (DeclContext *C : llvm::reverse(CurContextChain)) { 4794 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) 4795 CurContextIdentifiers.push_back(ND->getIdentifier()); 4796 } 4797 4798 // Add the global context as a NestedNameSpecifier 4799 SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()), 4800 NestedNameSpecifier::GlobalSpecifier(Context), 1}; 4801 DistanceMap[1].push_back(SI); 4802 } 4803 4804 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain( 4805 DeclContext *Start) -> DeclContextList { 4806 assert(Start && "Building a context chain from a null context"); 4807 DeclContextList Chain; 4808 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr; 4809 DC = DC->getLookupParent()) { 4810 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC); 4811 if (!DC->isInlineNamespace() && !DC->isTransparentContext() && 4812 !(ND && ND->isAnonymousNamespace())) 4813 Chain.push_back(DC->getPrimaryContext()); 4814 } 4815 return Chain; 4816 } 4817 4818 unsigned 4819 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier( 4820 DeclContextList &DeclChain, NestedNameSpecifier *&NNS) { 4821 unsigned NumSpecifiers = 0; 4822 for (DeclContext *C : llvm::reverse(DeclChain)) { 4823 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) { 4824 NNS = NestedNameSpecifier::Create(Context, NNS, ND); 4825 ++NumSpecifiers; 4826 } else if (auto *RD = dyn_cast_or_null<RecordDecl>(C)) { 4827 NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(), 4828 RD->getTypeForDecl()); 4829 ++NumSpecifiers; 4830 } 4831 } 4832 return NumSpecifiers; 4833 } 4834 4835 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier( 4836 DeclContext *Ctx) { 4837 NestedNameSpecifier *NNS = nullptr; 4838 unsigned NumSpecifiers = 0; 4839 DeclContextList NamespaceDeclChain(buildContextChain(Ctx)); 4840 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain); 4841 4842 // Eliminate common elements from the two DeclContext chains. 4843 for (DeclContext *C : llvm::reverse(CurContextChain)) { 4844 if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C) 4845 break; 4846 NamespaceDeclChain.pop_back(); 4847 } 4848 4849 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain 4850 NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS); 4851 4852 // Add an explicit leading '::' specifier if needed. 4853 if (NamespaceDeclChain.empty()) { 4854 // Rebuild the NestedNameSpecifier as a globally-qualified specifier. 4855 NNS = NestedNameSpecifier::GlobalSpecifier(Context); 4856 NumSpecifiers = 4857 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS); 4858 } else if (NamedDecl *ND = 4859 dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) { 4860 IdentifierInfo *Name = ND->getIdentifier(); 4861 bool SameNameSpecifier = false; 4862 if (llvm::is_contained(CurNameSpecifierIdentifiers, Name)) { 4863 std::string NewNameSpecifier; 4864 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier); 4865 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers; 4866 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers); 4867 NNS->print(SpecifierOStream, Context.getPrintingPolicy()); 4868 SpecifierOStream.flush(); 4869 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier; 4870 } 4871 if (SameNameSpecifier || llvm::is_contained(CurContextIdentifiers, Name)) { 4872 // Rebuild the NestedNameSpecifier as a globally-qualified specifier. 4873 NNS = NestedNameSpecifier::GlobalSpecifier(Context); 4874 NumSpecifiers = 4875 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS); 4876 } 4877 } 4878 4879 // If the built NestedNameSpecifier would be replacing an existing 4880 // NestedNameSpecifier, use the number of component identifiers that 4881 // would need to be changed as the edit distance instead of the number 4882 // of components in the built NestedNameSpecifier. 4883 if (NNS && !CurNameSpecifierIdentifiers.empty()) { 4884 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers; 4885 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers); 4886 NumSpecifiers = llvm::ComputeEditDistance( 4887 llvm::makeArrayRef(CurNameSpecifierIdentifiers), 4888 llvm::makeArrayRef(NewNameSpecifierIdentifiers)); 4889 } 4890 4891 SpecifierInfo SI = {Ctx, NNS, NumSpecifiers}; 4892 DistanceMap[NumSpecifiers].push_back(SI); 4893 } 4894 4895 /// Perform name lookup for a possible result for typo correction. 4896 static void LookupPotentialTypoResult(Sema &SemaRef, 4897 LookupResult &Res, 4898 IdentifierInfo *Name, 4899 Scope *S, CXXScopeSpec *SS, 4900 DeclContext *MemberContext, 4901 bool EnteringContext, 4902 bool isObjCIvarLookup, 4903 bool FindHidden) { 4904 Res.suppressDiagnostics(); 4905 Res.clear(); 4906 Res.setLookupName(Name); 4907 Res.setAllowHidden(FindHidden); 4908 if (MemberContext) { 4909 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) { 4910 if (isObjCIvarLookup) { 4911 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) { 4912 Res.addDecl(Ivar); 4913 Res.resolveKind(); 4914 return; 4915 } 4916 } 4917 4918 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration( 4919 Name, ObjCPropertyQueryKind::OBJC_PR_query_instance)) { 4920 Res.addDecl(Prop); 4921 Res.resolveKind(); 4922 return; 4923 } 4924 } 4925 4926 SemaRef.LookupQualifiedName(Res, MemberContext); 4927 return; 4928 } 4929 4930 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false, 4931 EnteringContext); 4932 4933 // Fake ivar lookup; this should really be part of 4934 // LookupParsedName. 4935 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) { 4936 if (Method->isInstanceMethod() && Method->getClassInterface() && 4937 (Res.empty() || 4938 (Res.isSingleResult() && 4939 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) { 4940 if (ObjCIvarDecl *IV 4941 = Method->getClassInterface()->lookupInstanceVariable(Name)) { 4942 Res.addDecl(IV); 4943 Res.resolveKind(); 4944 } 4945 } 4946 } 4947 } 4948 4949 /// Add keywords to the consumer as possible typo corrections. 4950 static void AddKeywordsToConsumer(Sema &SemaRef, 4951 TypoCorrectionConsumer &Consumer, 4952 Scope *S, CorrectionCandidateCallback &CCC, 4953 bool AfterNestedNameSpecifier) { 4954 if (AfterNestedNameSpecifier) { 4955 // For 'X::', we know exactly which keywords can appear next. 4956 Consumer.addKeywordResult("template"); 4957 if (CCC.WantExpressionKeywords) 4958 Consumer.addKeywordResult("operator"); 4959 return; 4960 } 4961 4962 if (CCC.WantObjCSuper) 4963 Consumer.addKeywordResult("super"); 4964 4965 if (CCC.WantTypeSpecifiers) { 4966 // Add type-specifier keywords to the set of results. 4967 static const char *const CTypeSpecs[] = { 4968 "char", "const", "double", "enum", "float", "int", "long", "short", 4969 "signed", "struct", "union", "unsigned", "void", "volatile", 4970 "_Complex", "_Imaginary", 4971 // storage-specifiers as well 4972 "extern", "inline", "static", "typedef" 4973 }; 4974 4975 const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs); 4976 for (unsigned I = 0; I != NumCTypeSpecs; ++I) 4977 Consumer.addKeywordResult(CTypeSpecs[I]); 4978 4979 if (SemaRef.getLangOpts().C99) 4980 Consumer.addKeywordResult("restrict"); 4981 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) 4982 Consumer.addKeywordResult("bool"); 4983 else if (SemaRef.getLangOpts().C99) 4984 Consumer.addKeywordResult("_Bool"); 4985 4986 if (SemaRef.getLangOpts().CPlusPlus) { 4987 Consumer.addKeywordResult("class"); 4988 Consumer.addKeywordResult("typename"); 4989 Consumer.addKeywordResult("wchar_t"); 4990 4991 if (SemaRef.getLangOpts().CPlusPlus11) { 4992 Consumer.addKeywordResult("char16_t"); 4993 Consumer.addKeywordResult("char32_t"); 4994 Consumer.addKeywordResult("constexpr"); 4995 Consumer.addKeywordResult("decltype"); 4996 Consumer.addKeywordResult("thread_local"); 4997 } 4998 } 4999 5000 if (SemaRef.getLangOpts().GNUKeywords) 5001 Consumer.addKeywordResult("typeof"); 5002 } else if (CCC.WantFunctionLikeCasts) { 5003 static const char *const CastableTypeSpecs[] = { 5004 "char", "double", "float", "int", "long", "short", 5005 "signed", "unsigned", "void" 5006 }; 5007 for (auto *kw : CastableTypeSpecs) 5008 Consumer.addKeywordResult(kw); 5009 } 5010 5011 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) { 5012 Consumer.addKeywordResult("const_cast"); 5013 Consumer.addKeywordResult("dynamic_cast"); 5014 Consumer.addKeywordResult("reinterpret_cast"); 5015 Consumer.addKeywordResult("static_cast"); 5016 } 5017 5018 if (CCC.WantExpressionKeywords) { 5019 Consumer.addKeywordResult("sizeof"); 5020 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) { 5021 Consumer.addKeywordResult("false"); 5022 Consumer.addKeywordResult("true"); 5023 } 5024 5025 if (SemaRef.getLangOpts().CPlusPlus) { 5026 static const char *const CXXExprs[] = { 5027 "delete", "new", "operator", "throw", "typeid" 5028 }; 5029 const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs); 5030 for (unsigned I = 0; I != NumCXXExprs; ++I) 5031 Consumer.addKeywordResult(CXXExprs[I]); 5032 5033 if (isa<CXXMethodDecl>(SemaRef.CurContext) && 5034 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance()) 5035 Consumer.addKeywordResult("this"); 5036 5037 if (SemaRef.getLangOpts().CPlusPlus11) { 5038 Consumer.addKeywordResult("alignof"); 5039 Consumer.addKeywordResult("nullptr"); 5040 } 5041 } 5042 5043 if (SemaRef.getLangOpts().C11) { 5044 // FIXME: We should not suggest _Alignof if the alignof macro 5045 // is present. 5046 Consumer.addKeywordResult("_Alignof"); 5047 } 5048 } 5049 5050 if (CCC.WantRemainingKeywords) { 5051 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) { 5052 // Statements. 5053 static const char *const CStmts[] = { 5054 "do", "else", "for", "goto", "if", "return", "switch", "while" }; 5055 const unsigned NumCStmts = llvm::array_lengthof(CStmts); 5056 for (unsigned I = 0; I != NumCStmts; ++I) 5057 Consumer.addKeywordResult(CStmts[I]); 5058 5059 if (SemaRef.getLangOpts().CPlusPlus) { 5060 Consumer.addKeywordResult("catch"); 5061 Consumer.addKeywordResult("try"); 5062 } 5063 5064 if (S && S->getBreakParent()) 5065 Consumer.addKeywordResult("break"); 5066 5067 if (S && S->getContinueParent()) 5068 Consumer.addKeywordResult("continue"); 5069 5070 if (SemaRef.getCurFunction() && 5071 !SemaRef.getCurFunction()->SwitchStack.empty()) { 5072 Consumer.addKeywordResult("case"); 5073 Consumer.addKeywordResult("default"); 5074 } 5075 } else { 5076 if (SemaRef.getLangOpts().CPlusPlus) { 5077 Consumer.addKeywordResult("namespace"); 5078 Consumer.addKeywordResult("template"); 5079 } 5080 5081 if (S && S->isClassScope()) { 5082 Consumer.addKeywordResult("explicit"); 5083 Consumer.addKeywordResult("friend"); 5084 Consumer.addKeywordResult("mutable"); 5085 Consumer.addKeywordResult("private"); 5086 Consumer.addKeywordResult("protected"); 5087 Consumer.addKeywordResult("public"); 5088 Consumer.addKeywordResult("virtual"); 5089 } 5090 } 5091 5092 if (SemaRef.getLangOpts().CPlusPlus) { 5093 Consumer.addKeywordResult("using"); 5094 5095 if (SemaRef.getLangOpts().CPlusPlus11) 5096 Consumer.addKeywordResult("static_assert"); 5097 } 5098 } 5099 } 5100 5101 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer( 5102 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind, 5103 Scope *S, CXXScopeSpec *SS, CorrectionCandidateCallback &CCC, 5104 DeclContext *MemberContext, bool EnteringContext, 5105 const ObjCObjectPointerType *OPT, bool ErrorRecovery) { 5106 5107 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking || 5108 DisableTypoCorrection) 5109 return nullptr; 5110 5111 // In Microsoft mode, don't perform typo correction in a template member 5112 // function dependent context because it interferes with the "lookup into 5113 // dependent bases of class templates" feature. 5114 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() && 5115 isa<CXXMethodDecl>(CurContext)) 5116 return nullptr; 5117 5118 // We only attempt to correct typos for identifiers. 5119 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 5120 if (!Typo) 5121 return nullptr; 5122 5123 // If the scope specifier itself was invalid, don't try to correct 5124 // typos. 5125 if (SS && SS->isInvalid()) 5126 return nullptr; 5127 5128 // Never try to correct typos during any kind of code synthesis. 5129 if (!CodeSynthesisContexts.empty()) 5130 return nullptr; 5131 5132 // Don't try to correct 'super'. 5133 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier()) 5134 return nullptr; 5135 5136 // Abort if typo correction already failed for this specific typo. 5137 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo); 5138 if (locs != TypoCorrectionFailures.end() && 5139 locs->second.count(TypoName.getLoc())) 5140 return nullptr; 5141 5142 // Don't try to correct the identifier "vector" when in AltiVec mode. 5143 // TODO: Figure out why typo correction misbehaves in this case, fix it, and 5144 // remove this workaround. 5145 if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector")) 5146 return nullptr; 5147 5148 // Provide a stop gap for files that are just seriously broken. Trying 5149 // to correct all typos can turn into a HUGE performance penalty, causing 5150 // some files to take minutes to get rejected by the parser. 5151 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit; 5152 if (Limit && TyposCorrected >= Limit) 5153 return nullptr; 5154 ++TyposCorrected; 5155 5156 // If we're handling a missing symbol error, using modules, and the 5157 // special search all modules option is used, look for a missing import. 5158 if (ErrorRecovery && getLangOpts().Modules && 5159 getLangOpts().ModulesSearchAll) { 5160 // The following has the side effect of loading the missing module. 5161 getModuleLoader().lookupMissingImports(Typo->getName(), 5162 TypoName.getBeginLoc()); 5163 } 5164 5165 // Extend the lifetime of the callback. We delayed this until here 5166 // to avoid allocations in the hot path (which is where no typo correction 5167 // occurs). Note that CorrectionCandidateCallback is polymorphic and 5168 // initially stack-allocated. 5169 std::unique_ptr<CorrectionCandidateCallback> ClonedCCC = CCC.clone(); 5170 auto Consumer = std::make_unique<TypoCorrectionConsumer>( 5171 *this, TypoName, LookupKind, S, SS, std::move(ClonedCCC), MemberContext, 5172 EnteringContext); 5173 5174 // Perform name lookup to find visible, similarly-named entities. 5175 bool IsUnqualifiedLookup = false; 5176 DeclContext *QualifiedDC = MemberContext; 5177 if (MemberContext) { 5178 LookupVisibleDecls(MemberContext, LookupKind, *Consumer); 5179 5180 // Look in qualified interfaces. 5181 if (OPT) { 5182 for (auto *I : OPT->quals()) 5183 LookupVisibleDecls(I, LookupKind, *Consumer); 5184 } 5185 } else if (SS && SS->isSet()) { 5186 QualifiedDC = computeDeclContext(*SS, EnteringContext); 5187 if (!QualifiedDC) 5188 return nullptr; 5189 5190 LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer); 5191 } else { 5192 IsUnqualifiedLookup = true; 5193 } 5194 5195 // Determine whether we are going to search in the various namespaces for 5196 // corrections. 5197 bool SearchNamespaces 5198 = getLangOpts().CPlusPlus && 5199 (IsUnqualifiedLookup || (SS && SS->isSet())); 5200 5201 if (IsUnqualifiedLookup || SearchNamespaces) { 5202 // For unqualified lookup, look through all of the names that we have 5203 // seen in this translation unit. 5204 // FIXME: Re-add the ability to skip very unlikely potential corrections. 5205 for (const auto &I : Context.Idents) 5206 Consumer->FoundName(I.getKey()); 5207 5208 // Walk through identifiers in external identifier sources. 5209 // FIXME: Re-add the ability to skip very unlikely potential corrections. 5210 if (IdentifierInfoLookup *External 5211 = Context.Idents.getExternalIdentifierLookup()) { 5212 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers()); 5213 do { 5214 StringRef Name = Iter->Next(); 5215 if (Name.empty()) 5216 break; 5217 5218 Consumer->FoundName(Name); 5219 } while (true); 5220 } 5221 } 5222 5223 AddKeywordsToConsumer(*this, *Consumer, S, 5224 *Consumer->getCorrectionValidator(), 5225 SS && SS->isNotEmpty()); 5226 5227 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going 5228 // to search those namespaces. 5229 if (SearchNamespaces) { 5230 // Load any externally-known namespaces. 5231 if (ExternalSource && !LoadedExternalKnownNamespaces) { 5232 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces; 5233 LoadedExternalKnownNamespaces = true; 5234 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces); 5235 for (auto *N : ExternalKnownNamespaces) 5236 KnownNamespaces[N] = true; 5237 } 5238 5239 Consumer->addNamespaces(KnownNamespaces); 5240 } 5241 5242 return Consumer; 5243 } 5244 5245 /// Try to "correct" a typo in the source code by finding 5246 /// visible declarations whose names are similar to the name that was 5247 /// present in the source code. 5248 /// 5249 /// \param TypoName the \c DeclarationNameInfo structure that contains 5250 /// the name that was present in the source code along with its location. 5251 /// 5252 /// \param LookupKind the name-lookup criteria used to search for the name. 5253 /// 5254 /// \param S the scope in which name lookup occurs. 5255 /// 5256 /// \param SS the nested-name-specifier that precedes the name we're 5257 /// looking for, if present. 5258 /// 5259 /// \param CCC A CorrectionCandidateCallback object that provides further 5260 /// validation of typo correction candidates. It also provides flags for 5261 /// determining the set of keywords permitted. 5262 /// 5263 /// \param MemberContext if non-NULL, the context in which to look for 5264 /// a member access expression. 5265 /// 5266 /// \param EnteringContext whether we're entering the context described by 5267 /// the nested-name-specifier SS. 5268 /// 5269 /// \param OPT when non-NULL, the search for visible declarations will 5270 /// also walk the protocols in the qualified interfaces of \p OPT. 5271 /// 5272 /// \returns a \c TypoCorrection containing the corrected name if the typo 5273 /// along with information such as the \c NamedDecl where the corrected name 5274 /// was declared, and any additional \c NestedNameSpecifier needed to access 5275 /// it (C++ only). The \c TypoCorrection is empty if there is no correction. 5276 TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName, 5277 Sema::LookupNameKind LookupKind, 5278 Scope *S, CXXScopeSpec *SS, 5279 CorrectionCandidateCallback &CCC, 5280 CorrectTypoKind Mode, 5281 DeclContext *MemberContext, 5282 bool EnteringContext, 5283 const ObjCObjectPointerType *OPT, 5284 bool RecordFailure) { 5285 // Always let the ExternalSource have the first chance at correction, even 5286 // if we would otherwise have given up. 5287 if (ExternalSource) { 5288 if (TypoCorrection Correction = 5289 ExternalSource->CorrectTypo(TypoName, LookupKind, S, SS, CCC, 5290 MemberContext, EnteringContext, OPT)) 5291 return Correction; 5292 } 5293 5294 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver; 5295 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for 5296 // some instances of CTC_Unknown, while WantRemainingKeywords is true 5297 // for CTC_Unknown but not for CTC_ObjCMessageReceiver. 5298 bool ObjCMessageReceiver = CCC.WantObjCSuper && !CCC.WantRemainingKeywords; 5299 5300 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 5301 auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC, 5302 MemberContext, EnteringContext, 5303 OPT, Mode == CTK_ErrorRecovery); 5304 5305 if (!Consumer) 5306 return TypoCorrection(); 5307 5308 // If we haven't found anything, we're done. 5309 if (Consumer->empty()) 5310 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5311 5312 // Make sure the best edit distance (prior to adding any namespace qualifiers) 5313 // is not more that about a third of the length of the typo's identifier. 5314 unsigned ED = Consumer->getBestEditDistance(true); 5315 unsigned TypoLen = Typo->getName().size(); 5316 if (ED > 0 && TypoLen / ED < 3) 5317 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5318 5319 TypoCorrection BestTC = Consumer->getNextCorrection(); 5320 TypoCorrection SecondBestTC = Consumer->getNextCorrection(); 5321 if (!BestTC) 5322 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5323 5324 ED = BestTC.getEditDistance(); 5325 5326 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) { 5327 // If this was an unqualified lookup and we believe the callback 5328 // object wouldn't have filtered out possible corrections, note 5329 // that no correction was found. 5330 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5331 } 5332 5333 // If only a single name remains, return that result. 5334 if (!SecondBestTC || 5335 SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) { 5336 const TypoCorrection &Result = BestTC; 5337 5338 // Don't correct to a keyword that's the same as the typo; the keyword 5339 // wasn't actually in scope. 5340 if (ED == 0 && Result.isKeyword()) 5341 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5342 5343 TypoCorrection TC = Result; 5344 TC.setCorrectionRange(SS, TypoName); 5345 checkCorrectionVisibility(*this, TC); 5346 return TC; 5347 } else if (SecondBestTC && ObjCMessageReceiver) { 5348 // Prefer 'super' when we're completing in a message-receiver 5349 // context. 5350 5351 if (BestTC.getCorrection().getAsString() != "super") { 5352 if (SecondBestTC.getCorrection().getAsString() == "super") 5353 BestTC = SecondBestTC; 5354 else if ((*Consumer)["super"].front().isKeyword()) 5355 BestTC = (*Consumer)["super"].front(); 5356 } 5357 // Don't correct to a keyword that's the same as the typo; the keyword 5358 // wasn't actually in scope. 5359 if (BestTC.getEditDistance() == 0 || 5360 BestTC.getCorrection().getAsString() != "super") 5361 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5362 5363 BestTC.setCorrectionRange(SS, TypoName); 5364 return BestTC; 5365 } 5366 5367 // Record the failure's location if needed and return an empty correction. If 5368 // this was an unqualified lookup and we believe the callback object did not 5369 // filter out possible corrections, also cache the failure for the typo. 5370 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC); 5371 } 5372 5373 /// Try to "correct" a typo in the source code by finding 5374 /// visible declarations whose names are similar to the name that was 5375 /// present in the source code. 5376 /// 5377 /// \param TypoName the \c DeclarationNameInfo structure that contains 5378 /// the name that was present in the source code along with its location. 5379 /// 5380 /// \param LookupKind the name-lookup criteria used to search for the name. 5381 /// 5382 /// \param S the scope in which name lookup occurs. 5383 /// 5384 /// \param SS the nested-name-specifier that precedes the name we're 5385 /// looking for, if present. 5386 /// 5387 /// \param CCC A CorrectionCandidateCallback object that provides further 5388 /// validation of typo correction candidates. It also provides flags for 5389 /// determining the set of keywords permitted. 5390 /// 5391 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print 5392 /// diagnostics when the actual typo correction is attempted. 5393 /// 5394 /// \param TRC A TypoRecoveryCallback functor that will be used to build an 5395 /// Expr from a typo correction candidate. 5396 /// 5397 /// \param MemberContext if non-NULL, the context in which to look for 5398 /// a member access expression. 5399 /// 5400 /// \param EnteringContext whether we're entering the context described by 5401 /// the nested-name-specifier SS. 5402 /// 5403 /// \param OPT when non-NULL, the search for visible declarations will 5404 /// also walk the protocols in the qualified interfaces of \p OPT. 5405 /// 5406 /// \returns a new \c TypoExpr that will later be replaced in the AST with an 5407 /// Expr representing the result of performing typo correction, or nullptr if 5408 /// typo correction is not possible. If nullptr is returned, no diagnostics will 5409 /// be emitted and it is the responsibility of the caller to emit any that are 5410 /// needed. 5411 TypoExpr *Sema::CorrectTypoDelayed( 5412 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind, 5413 Scope *S, CXXScopeSpec *SS, CorrectionCandidateCallback &CCC, 5414 TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode, 5415 DeclContext *MemberContext, bool EnteringContext, 5416 const ObjCObjectPointerType *OPT) { 5417 auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC, 5418 MemberContext, EnteringContext, 5419 OPT, Mode == CTK_ErrorRecovery); 5420 5421 // Give the external sema source a chance to correct the typo. 5422 TypoCorrection ExternalTypo; 5423 if (ExternalSource && Consumer) { 5424 ExternalTypo = ExternalSource->CorrectTypo( 5425 TypoName, LookupKind, S, SS, *Consumer->getCorrectionValidator(), 5426 MemberContext, EnteringContext, OPT); 5427 if (ExternalTypo) 5428 Consumer->addCorrection(ExternalTypo); 5429 } 5430 5431 if (!Consumer || Consumer->empty()) 5432 return nullptr; 5433 5434 // Make sure the best edit distance (prior to adding any namespace qualifiers) 5435 // is not more that about a third of the length of the typo's identifier. 5436 unsigned ED = Consumer->getBestEditDistance(true); 5437 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 5438 if (!ExternalTypo && ED > 0 && Typo->getName().size() / ED < 3) 5439 return nullptr; 5440 ExprEvalContexts.back().NumTypos++; 5441 return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC), 5442 TypoName.getLoc()); 5443 } 5444 5445 void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) { 5446 if (!CDecl) return; 5447 5448 if (isKeyword()) 5449 CorrectionDecls.clear(); 5450 5451 CorrectionDecls.push_back(CDecl); 5452 5453 if (!CorrectionName) 5454 CorrectionName = CDecl->getDeclName(); 5455 } 5456 5457 std::string TypoCorrection::getAsString(const LangOptions &LO) const { 5458 if (CorrectionNameSpec) { 5459 std::string tmpBuffer; 5460 llvm::raw_string_ostream PrefixOStream(tmpBuffer); 5461 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO)); 5462 PrefixOStream << CorrectionName; 5463 return PrefixOStream.str(); 5464 } 5465 5466 return CorrectionName.getAsString(); 5467 } 5468 5469 bool CorrectionCandidateCallback::ValidateCandidate( 5470 const TypoCorrection &candidate) { 5471 if (!candidate.isResolved()) 5472 return true; 5473 5474 if (candidate.isKeyword()) 5475 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts || 5476 WantRemainingKeywords || WantObjCSuper; 5477 5478 bool HasNonType = false; 5479 bool HasStaticMethod = false; 5480 bool HasNonStaticMethod = false; 5481 for (Decl *D : candidate) { 5482 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D)) 5483 D = FTD->getTemplatedDecl(); 5484 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 5485 if (Method->isStatic()) 5486 HasStaticMethod = true; 5487 else 5488 HasNonStaticMethod = true; 5489 } 5490 if (!isa<TypeDecl>(D)) 5491 HasNonType = true; 5492 } 5493 5494 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod && 5495 !candidate.getCorrectionSpecifier()) 5496 return false; 5497 5498 return WantTypeSpecifiers || HasNonType; 5499 } 5500 5501 FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs, 5502 bool HasExplicitTemplateArgs, 5503 MemberExpr *ME) 5504 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs), 5505 CurContext(SemaRef.CurContext), MemberFn(ME) { 5506 WantTypeSpecifiers = false; 5507 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && 5508 !HasExplicitTemplateArgs && NumArgs == 1; 5509 WantCXXNamedCasts = HasExplicitTemplateArgs && NumArgs == 1; 5510 WantRemainingKeywords = false; 5511 } 5512 5513 bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) { 5514 if (!candidate.getCorrectionDecl()) 5515 return candidate.isKeyword(); 5516 5517 for (auto *C : candidate) { 5518 FunctionDecl *FD = nullptr; 5519 NamedDecl *ND = C->getUnderlyingDecl(); 5520 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 5521 FD = FTD->getTemplatedDecl(); 5522 if (!HasExplicitTemplateArgs && !FD) { 5523 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) { 5524 // If the Decl is neither a function nor a template function, 5525 // determine if it is a pointer or reference to a function. If so, 5526 // check against the number of arguments expected for the pointee. 5527 QualType ValType = cast<ValueDecl>(ND)->getType(); 5528 if (ValType.isNull()) 5529 continue; 5530 if (ValType->isAnyPointerType() || ValType->isReferenceType()) 5531 ValType = ValType->getPointeeType(); 5532 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>()) 5533 if (FPT->getNumParams() == NumArgs) 5534 return true; 5535 } 5536 } 5537 5538 // A typo for a function-style cast can look like a function call in C++. 5539 if ((HasExplicitTemplateArgs ? getAsTypeTemplateDecl(ND) != nullptr 5540 : isa<TypeDecl>(ND)) && 5541 CurContext->getParentASTContext().getLangOpts().CPlusPlus) 5542 // Only a class or class template can take two or more arguments. 5543 return NumArgs <= 1 || HasExplicitTemplateArgs || isa<CXXRecordDecl>(ND); 5544 5545 // Skip the current candidate if it is not a FunctionDecl or does not accept 5546 // the current number of arguments. 5547 if (!FD || !(FD->getNumParams() >= NumArgs && 5548 FD->getMinRequiredArguments() <= NumArgs)) 5549 continue; 5550 5551 // If the current candidate is a non-static C++ method, skip the candidate 5552 // unless the method being corrected--or the current DeclContext, if the 5553 // function being corrected is not a method--is a method in the same class 5554 // or a descendent class of the candidate's parent class. 5555 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) { 5556 if (MemberFn || !MD->isStatic()) { 5557 CXXMethodDecl *CurMD = 5558 MemberFn 5559 ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl()) 5560 : dyn_cast_or_null<CXXMethodDecl>(CurContext); 5561 CXXRecordDecl *CurRD = 5562 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr; 5563 CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl(); 5564 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD))) 5565 continue; 5566 } 5567 } 5568 return true; 5569 } 5570 return false; 5571 } 5572 5573 void Sema::diagnoseTypo(const TypoCorrection &Correction, 5574 const PartialDiagnostic &TypoDiag, 5575 bool ErrorRecovery) { 5576 diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl), 5577 ErrorRecovery); 5578 } 5579 5580 /// Find which declaration we should import to provide the definition of 5581 /// the given declaration. 5582 static NamedDecl *getDefinitionToImport(NamedDecl *D) { 5583 if (VarDecl *VD = dyn_cast<VarDecl>(D)) 5584 return VD->getDefinition(); 5585 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) 5586 return FD->getDefinition(); 5587 if (TagDecl *TD = dyn_cast<TagDecl>(D)) 5588 return TD->getDefinition(); 5589 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D)) 5590 return ID->getDefinition(); 5591 if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D)) 5592 return PD->getDefinition(); 5593 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D)) 5594 if (NamedDecl *TTD = TD->getTemplatedDecl()) 5595 return getDefinitionToImport(TTD); 5596 return nullptr; 5597 } 5598 5599 void Sema::diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl, 5600 MissingImportKind MIK, bool Recover) { 5601 // Suggest importing a module providing the definition of this entity, if 5602 // possible. 5603 NamedDecl *Def = getDefinitionToImport(Decl); 5604 if (!Def) 5605 Def = Decl; 5606 5607 Module *Owner = getOwningModule(Def); 5608 assert(Owner && "definition of hidden declaration is not in a module"); 5609 5610 llvm::SmallVector<Module*, 8> OwningModules; 5611 OwningModules.push_back(Owner); 5612 auto Merged = Context.getModulesWithMergedDefinition(Def); 5613 OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end()); 5614 5615 diagnoseMissingImport(Loc, Def, Def->getLocation(), OwningModules, MIK, 5616 Recover); 5617 } 5618 5619 /// Get a "quoted.h" or <angled.h> include path to use in a diagnostic 5620 /// suggesting the addition of a #include of the specified file. 5621 static std::string getHeaderNameForHeader(Preprocessor &PP, const FileEntry *E, 5622 llvm::StringRef IncludingFile) { 5623 bool IsSystem = false; 5624 auto Path = PP.getHeaderSearchInfo().suggestPathToFileForDiagnostics( 5625 E, IncludingFile, &IsSystem); 5626 return (IsSystem ? '<' : '"') + Path + (IsSystem ? '>' : '"'); 5627 } 5628 5629 void Sema::diagnoseMissingImport(SourceLocation UseLoc, NamedDecl *Decl, 5630 SourceLocation DeclLoc, 5631 ArrayRef<Module *> Modules, 5632 MissingImportKind MIK, bool Recover) { 5633 assert(!Modules.empty()); 5634 5635 auto NotePrevious = [&] { 5636 // FIXME: Suppress the note backtrace even under 5637 // -fdiagnostics-show-note-include-stack. We don't care how this 5638 // declaration was previously reached. 5639 Diag(DeclLoc, diag::note_unreachable_entity) << (int)MIK; 5640 }; 5641 5642 // Weed out duplicates from module list. 5643 llvm::SmallVector<Module*, 8> UniqueModules; 5644 llvm::SmallDenseSet<Module*, 8> UniqueModuleSet; 5645 for (auto *M : Modules) { 5646 if (M->Kind == Module::GlobalModuleFragment) 5647 continue; 5648 if (UniqueModuleSet.insert(M).second) 5649 UniqueModules.push_back(M); 5650 } 5651 5652 // Try to find a suitable header-name to #include. 5653 std::string HeaderName; 5654 if (const FileEntry *Header = 5655 PP.getHeaderToIncludeForDiagnostics(UseLoc, DeclLoc)) { 5656 if (const FileEntry *FE = 5657 SourceMgr.getFileEntryForID(SourceMgr.getFileID(UseLoc))) 5658 HeaderName = getHeaderNameForHeader(PP, Header, FE->tryGetRealPathName()); 5659 } 5660 5661 // If we have a #include we should suggest, or if all definition locations 5662 // were in global module fragments, don't suggest an import. 5663 if (!HeaderName.empty() || UniqueModules.empty()) { 5664 // FIXME: Find a smart place to suggest inserting a #include, and add 5665 // a FixItHint there. 5666 Diag(UseLoc, diag::err_module_unimported_use_header) 5667 << (int)MIK << Decl << !HeaderName.empty() << HeaderName; 5668 // Produce a note showing where the entity was declared. 5669 NotePrevious(); 5670 if (Recover) 5671 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]); 5672 return; 5673 } 5674 5675 Modules = UniqueModules; 5676 5677 if (Modules.size() > 1) { 5678 std::string ModuleList; 5679 unsigned N = 0; 5680 for (Module *M : Modules) { 5681 ModuleList += "\n "; 5682 if (++N == 5 && N != Modules.size()) { 5683 ModuleList += "[...]"; 5684 break; 5685 } 5686 ModuleList += M->getFullModuleName(); 5687 } 5688 5689 Diag(UseLoc, diag::err_module_unimported_use_multiple) 5690 << (int)MIK << Decl << ModuleList; 5691 } else { 5692 // FIXME: Add a FixItHint that imports the corresponding module. 5693 Diag(UseLoc, diag::err_module_unimported_use) 5694 << (int)MIK << Decl << Modules[0]->getFullModuleName(); 5695 } 5696 5697 NotePrevious(); 5698 5699 // Try to recover by implicitly importing this module. 5700 if (Recover) 5701 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]); 5702 } 5703 5704 /// Diagnose a successfully-corrected typo. Separated from the correction 5705 /// itself to allow external validation of the result, etc. 5706 /// 5707 /// \param Correction The result of performing typo correction. 5708 /// \param TypoDiag The diagnostic to produce. This will have the corrected 5709 /// string added to it (and usually also a fixit). 5710 /// \param PrevNote A note to use when indicating the location of the entity to 5711 /// which we are correcting. Will have the correction string added to it. 5712 /// \param ErrorRecovery If \c true (the default), the caller is going to 5713 /// recover from the typo as if the corrected string had been typed. 5714 /// In this case, \c PDiag must be an error, and we will attach a fixit 5715 /// to it. 5716 void Sema::diagnoseTypo(const TypoCorrection &Correction, 5717 const PartialDiagnostic &TypoDiag, 5718 const PartialDiagnostic &PrevNote, 5719 bool ErrorRecovery) { 5720 std::string CorrectedStr = Correction.getAsString(getLangOpts()); 5721 std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts()); 5722 FixItHint FixTypo = FixItHint::CreateReplacement( 5723 Correction.getCorrectionRange(), CorrectedStr); 5724 5725 // Maybe we're just missing a module import. 5726 if (Correction.requiresImport()) { 5727 NamedDecl *Decl = Correction.getFoundDecl(); 5728 assert(Decl && "import required but no declaration to import"); 5729 5730 diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl, 5731 MissingImportKind::Declaration, ErrorRecovery); 5732 return; 5733 } 5734 5735 Diag(Correction.getCorrectionRange().getBegin(), TypoDiag) 5736 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint()); 5737 5738 NamedDecl *ChosenDecl = 5739 Correction.isKeyword() ? nullptr : Correction.getFoundDecl(); 5740 if (PrevNote.getDiagID() && ChosenDecl) 5741 Diag(ChosenDecl->getLocation(), PrevNote) 5742 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo); 5743 5744 // Add any extra diagnostics. 5745 for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics()) 5746 Diag(Correction.getCorrectionRange().getBegin(), PD); 5747 } 5748 5749 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC, 5750 TypoDiagnosticGenerator TDG, 5751 TypoRecoveryCallback TRC, 5752 SourceLocation TypoLoc) { 5753 assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer"); 5754 auto TE = new (Context) TypoExpr(Context.DependentTy, TypoLoc); 5755 auto &State = DelayedTypos[TE]; 5756 State.Consumer = std::move(TCC); 5757 State.DiagHandler = std::move(TDG); 5758 State.RecoveryHandler = std::move(TRC); 5759 if (TE) 5760 TypoExprs.push_back(TE); 5761 return TE; 5762 } 5763 5764 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const { 5765 auto Entry = DelayedTypos.find(TE); 5766 assert(Entry != DelayedTypos.end() && 5767 "Failed to get the state for a TypoExpr!"); 5768 return Entry->second; 5769 } 5770 5771 void Sema::clearDelayedTypo(TypoExpr *TE) { 5772 DelayedTypos.erase(TE); 5773 } 5774 5775 void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) { 5776 DeclarationNameInfo Name(II, IILoc); 5777 LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration); 5778 R.suppressDiagnostics(); 5779 R.setHideTags(false); 5780 LookupName(R, S); 5781 R.dump(); 5782 } 5783