1 //===--------------------- SemaLookup.cpp - Name Lookup ------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements name lookup for C, C++, Objective-C, and 10 // Objective-C++. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "clang/AST/ASTContext.h" 15 #include "clang/AST/CXXInheritance.h" 16 #include "clang/AST/Decl.h" 17 #include "clang/AST/DeclCXX.h" 18 #include "clang/AST/DeclLookups.h" 19 #include "clang/AST/DeclObjC.h" 20 #include "clang/AST/DeclTemplate.h" 21 #include "clang/AST/Expr.h" 22 #include "clang/AST/ExprCXX.h" 23 #include "clang/Basic/Builtins.h" 24 #include "clang/Basic/FileManager.h" 25 #include "clang/Basic/LangOptions.h" 26 #include "clang/Lex/HeaderSearch.h" 27 #include "clang/Lex/ModuleLoader.h" 28 #include "clang/Lex/Preprocessor.h" 29 #include "clang/Sema/DeclSpec.h" 30 #include "clang/Sema/Lookup.h" 31 #include "clang/Sema/Overload.h" 32 #include "clang/Sema/RISCVIntrinsicManager.h" 33 #include "clang/Sema/Scope.h" 34 #include "clang/Sema/ScopeInfo.h" 35 #include "clang/Sema/Sema.h" 36 #include "clang/Sema/SemaInternal.h" 37 #include "clang/Sema/TemplateDeduction.h" 38 #include "clang/Sema/TypoCorrection.h" 39 #include "llvm/ADT/STLExtras.h" 40 #include "llvm/ADT/SmallPtrSet.h" 41 #include "llvm/ADT/TinyPtrVector.h" 42 #include "llvm/ADT/edit_distance.h" 43 #include "llvm/Support/ErrorHandling.h" 44 #include <algorithm> 45 #include <iterator> 46 #include <list> 47 #include <set> 48 #include <utility> 49 #include <vector> 50 51 #include "OpenCLBuiltins.inc" 52 53 using namespace clang; 54 using namespace sema; 55 56 namespace { 57 class UnqualUsingEntry { 58 const DeclContext *Nominated; 59 const DeclContext *CommonAncestor; 60 61 public: 62 UnqualUsingEntry(const DeclContext *Nominated, 63 const DeclContext *CommonAncestor) 64 : Nominated(Nominated), CommonAncestor(CommonAncestor) { 65 } 66 67 const DeclContext *getCommonAncestor() const { 68 return CommonAncestor; 69 } 70 71 const DeclContext *getNominatedNamespace() const { 72 return Nominated; 73 } 74 75 // Sort by the pointer value of the common ancestor. 76 struct Comparator { 77 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) { 78 return L.getCommonAncestor() < R.getCommonAncestor(); 79 } 80 81 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) { 82 return E.getCommonAncestor() < DC; 83 } 84 85 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) { 86 return DC < E.getCommonAncestor(); 87 } 88 }; 89 }; 90 91 /// A collection of using directives, as used by C++ unqualified 92 /// lookup. 93 class UnqualUsingDirectiveSet { 94 Sema &SemaRef; 95 96 typedef SmallVector<UnqualUsingEntry, 8> ListTy; 97 98 ListTy list; 99 llvm::SmallPtrSet<DeclContext*, 8> visited; 100 101 public: 102 UnqualUsingDirectiveSet(Sema &SemaRef) : SemaRef(SemaRef) {} 103 104 void visitScopeChain(Scope *S, Scope *InnermostFileScope) { 105 // C++ [namespace.udir]p1: 106 // During unqualified name lookup, the names appear as if they 107 // were declared in the nearest enclosing namespace which contains 108 // both the using-directive and the nominated namespace. 109 DeclContext *InnermostFileDC = InnermostFileScope->getEntity(); 110 assert(InnermostFileDC && InnermostFileDC->isFileContext()); 111 112 for (; S; S = S->getParent()) { 113 // C++ [namespace.udir]p1: 114 // A using-directive shall not appear in class scope, but may 115 // appear in namespace scope or in block scope. 116 DeclContext *Ctx = S->getEntity(); 117 if (Ctx && Ctx->isFileContext()) { 118 visit(Ctx, Ctx); 119 } else if (!Ctx || Ctx->isFunctionOrMethod()) { 120 for (auto *I : S->using_directives()) 121 if (SemaRef.isVisible(I)) 122 visit(I, InnermostFileDC); 123 } 124 } 125 } 126 127 // Visits a context and collect all of its using directives 128 // recursively. Treats all using directives as if they were 129 // declared in the context. 130 // 131 // A given context is only every visited once, so it is important 132 // that contexts be visited from the inside out in order to get 133 // the effective DCs right. 134 void visit(DeclContext *DC, DeclContext *EffectiveDC) { 135 if (!visited.insert(DC).second) 136 return; 137 138 addUsingDirectives(DC, EffectiveDC); 139 } 140 141 // Visits a using directive and collects all of its using 142 // directives recursively. Treats all using directives as if they 143 // were declared in the effective DC. 144 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 145 DeclContext *NS = UD->getNominatedNamespace(); 146 if (!visited.insert(NS).second) 147 return; 148 149 addUsingDirective(UD, EffectiveDC); 150 addUsingDirectives(NS, EffectiveDC); 151 } 152 153 // Adds all the using directives in a context (and those nominated 154 // by its using directives, transitively) as if they appeared in 155 // the given effective context. 156 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) { 157 SmallVector<DeclContext*, 4> queue; 158 while (true) { 159 for (auto UD : DC->using_directives()) { 160 DeclContext *NS = UD->getNominatedNamespace(); 161 if (SemaRef.isVisible(UD) && visited.insert(NS).second) { 162 addUsingDirective(UD, EffectiveDC); 163 queue.push_back(NS); 164 } 165 } 166 167 if (queue.empty()) 168 return; 169 170 DC = queue.pop_back_val(); 171 } 172 } 173 174 // Add a using directive as if it had been declared in the given 175 // context. This helps implement C++ [namespace.udir]p3: 176 // The using-directive is transitive: if a scope contains a 177 // using-directive that nominates a second namespace that itself 178 // contains using-directives, the effect is as if the 179 // using-directives from the second namespace also appeared in 180 // the first. 181 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { 182 // Find the common ancestor between the effective context and 183 // the nominated namespace. 184 DeclContext *Common = UD->getNominatedNamespace(); 185 while (!Common->Encloses(EffectiveDC)) 186 Common = Common->getParent(); 187 Common = Common->getPrimaryContext(); 188 189 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common)); 190 } 191 192 void done() { llvm::sort(list, UnqualUsingEntry::Comparator()); } 193 194 typedef ListTy::const_iterator const_iterator; 195 196 const_iterator begin() const { return list.begin(); } 197 const_iterator end() const { return list.end(); } 198 199 llvm::iterator_range<const_iterator> 200 getNamespacesFor(DeclContext *DC) const { 201 return llvm::make_range(std::equal_range(begin(), end(), 202 DC->getPrimaryContext(), 203 UnqualUsingEntry::Comparator())); 204 } 205 }; 206 } // end anonymous namespace 207 208 // Retrieve the set of identifier namespaces that correspond to a 209 // specific kind of name lookup. 210 static inline unsigned getIDNS(Sema::LookupNameKind NameKind, 211 bool CPlusPlus, 212 bool Redeclaration) { 213 unsigned IDNS = 0; 214 switch (NameKind) { 215 case Sema::LookupObjCImplicitSelfParam: 216 case Sema::LookupOrdinaryName: 217 case Sema::LookupRedeclarationWithLinkage: 218 case Sema::LookupLocalFriendName: 219 case Sema::LookupDestructorName: 220 IDNS = Decl::IDNS_Ordinary; 221 if (CPlusPlus) { 222 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace; 223 if (Redeclaration) 224 IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend; 225 } 226 if (Redeclaration) 227 IDNS |= Decl::IDNS_LocalExtern; 228 break; 229 230 case Sema::LookupOperatorName: 231 // Operator lookup is its own crazy thing; it is not the same 232 // as (e.g.) looking up an operator name for redeclaration. 233 assert(!Redeclaration && "cannot do redeclaration operator lookup"); 234 IDNS = Decl::IDNS_NonMemberOperator; 235 break; 236 237 case Sema::LookupTagName: 238 if (CPlusPlus) { 239 IDNS = Decl::IDNS_Type; 240 241 // When looking for a redeclaration of a tag name, we add: 242 // 1) TagFriend to find undeclared friend decls 243 // 2) Namespace because they can't "overload" with tag decls. 244 // 3) Tag because it includes class templates, which can't 245 // "overload" with tag decls. 246 if (Redeclaration) 247 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace; 248 } else { 249 IDNS = Decl::IDNS_Tag; 250 } 251 break; 252 253 case Sema::LookupLabel: 254 IDNS = Decl::IDNS_Label; 255 break; 256 257 case Sema::LookupMemberName: 258 IDNS = Decl::IDNS_Member; 259 if (CPlusPlus) 260 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary; 261 break; 262 263 case Sema::LookupNestedNameSpecifierName: 264 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace; 265 break; 266 267 case Sema::LookupNamespaceName: 268 IDNS = Decl::IDNS_Namespace; 269 break; 270 271 case Sema::LookupUsingDeclName: 272 assert(Redeclaration && "should only be used for redecl lookup"); 273 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member | 274 Decl::IDNS_Using | Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend | 275 Decl::IDNS_LocalExtern; 276 break; 277 278 case Sema::LookupObjCProtocolName: 279 IDNS = Decl::IDNS_ObjCProtocol; 280 break; 281 282 case Sema::LookupOMPReductionName: 283 IDNS = Decl::IDNS_OMPReduction; 284 break; 285 286 case Sema::LookupOMPMapperName: 287 IDNS = Decl::IDNS_OMPMapper; 288 break; 289 290 case Sema::LookupAnyName: 291 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member 292 | Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol 293 | Decl::IDNS_Type; 294 break; 295 } 296 return IDNS; 297 } 298 299 void LookupResult::configure() { 300 IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus, 301 isForRedeclaration()); 302 303 // If we're looking for one of the allocation or deallocation 304 // operators, make sure that the implicitly-declared new and delete 305 // operators can be found. 306 switch (NameInfo.getName().getCXXOverloadedOperator()) { 307 case OO_New: 308 case OO_Delete: 309 case OO_Array_New: 310 case OO_Array_Delete: 311 getSema().DeclareGlobalNewDelete(); 312 break; 313 314 default: 315 break; 316 } 317 318 // Compiler builtins are always visible, regardless of where they end 319 // up being declared. 320 if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) { 321 if (unsigned BuiltinID = Id->getBuiltinID()) { 322 if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 323 AllowHidden = true; 324 } 325 } 326 } 327 328 bool LookupResult::checkDebugAssumptions() const { 329 // This function is never called by NDEBUG builds. 330 assert(ResultKind != NotFound || Decls.size() == 0); 331 assert(ResultKind != Found || Decls.size() == 1); 332 assert(ResultKind != FoundOverloaded || Decls.size() > 1 || 333 (Decls.size() == 1 && 334 isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl()))); 335 assert(ResultKind != FoundUnresolvedValue || checkUnresolved()); 336 assert(ResultKind != Ambiguous || Decls.size() > 1 || 337 (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects || 338 Ambiguity == AmbiguousBaseSubobjectTypes))); 339 assert((Paths != nullptr) == (ResultKind == Ambiguous && 340 (Ambiguity == AmbiguousBaseSubobjectTypes || 341 Ambiguity == AmbiguousBaseSubobjects))); 342 return true; 343 } 344 345 // Necessary because CXXBasePaths is not complete in Sema.h 346 void LookupResult::deletePaths(CXXBasePaths *Paths) { 347 delete Paths; 348 } 349 350 /// Get a representative context for a declaration such that two declarations 351 /// will have the same context if they were found within the same scope. 352 static DeclContext *getContextForScopeMatching(Decl *D) { 353 // For function-local declarations, use that function as the context. This 354 // doesn't account for scopes within the function; the caller must deal with 355 // those. 356 DeclContext *DC = D->getLexicalDeclContext(); 357 if (DC->isFunctionOrMethod()) 358 return DC; 359 360 // Otherwise, look at the semantic context of the declaration. The 361 // declaration must have been found there. 362 return D->getDeclContext()->getRedeclContext(); 363 } 364 365 /// Determine whether \p D is a better lookup result than \p Existing, 366 /// given that they declare the same entity. 367 static bool isPreferredLookupResult(Sema &S, Sema::LookupNameKind Kind, 368 NamedDecl *D, NamedDecl *Existing) { 369 // When looking up redeclarations of a using declaration, prefer a using 370 // shadow declaration over any other declaration of the same entity. 371 if (Kind == Sema::LookupUsingDeclName && isa<UsingShadowDecl>(D) && 372 !isa<UsingShadowDecl>(Existing)) 373 return true; 374 375 auto *DUnderlying = D->getUnderlyingDecl(); 376 auto *EUnderlying = Existing->getUnderlyingDecl(); 377 378 // If they have different underlying declarations, prefer a typedef over the 379 // original type (this happens when two type declarations denote the same 380 // type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef 381 // might carry additional semantic information, such as an alignment override. 382 // However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag 383 // declaration over a typedef. Also prefer a tag over a typedef for 384 // destructor name lookup because in some contexts we only accept a 385 // class-name in a destructor declaration. 386 if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) { 387 assert(isa<TypeDecl>(DUnderlying) && isa<TypeDecl>(EUnderlying)); 388 bool HaveTag = isa<TagDecl>(EUnderlying); 389 bool WantTag = 390 Kind == Sema::LookupTagName || Kind == Sema::LookupDestructorName; 391 return HaveTag != WantTag; 392 } 393 394 // Pick the function with more default arguments. 395 // FIXME: In the presence of ambiguous default arguments, we should keep both, 396 // so we can diagnose the ambiguity if the default argument is needed. 397 // See C++ [over.match.best]p3. 398 if (auto *DFD = dyn_cast<FunctionDecl>(DUnderlying)) { 399 auto *EFD = cast<FunctionDecl>(EUnderlying); 400 unsigned DMin = DFD->getMinRequiredArguments(); 401 unsigned EMin = EFD->getMinRequiredArguments(); 402 // If D has more default arguments, it is preferred. 403 if (DMin != EMin) 404 return DMin < EMin; 405 // FIXME: When we track visibility for default function arguments, check 406 // that we pick the declaration with more visible default arguments. 407 } 408 409 // Pick the template with more default template arguments. 410 if (auto *DTD = dyn_cast<TemplateDecl>(DUnderlying)) { 411 auto *ETD = cast<TemplateDecl>(EUnderlying); 412 unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments(); 413 unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments(); 414 // If D has more default arguments, it is preferred. Note that default 415 // arguments (and their visibility) is monotonically increasing across the 416 // redeclaration chain, so this is a quick proxy for "is more recent". 417 if (DMin != EMin) 418 return DMin < EMin; 419 // If D has more *visible* default arguments, it is preferred. Note, an 420 // earlier default argument being visible does not imply that a later 421 // default argument is visible, so we can't just check the first one. 422 for (unsigned I = DMin, N = DTD->getTemplateParameters()->size(); 423 I != N; ++I) { 424 if (!S.hasVisibleDefaultArgument( 425 ETD->getTemplateParameters()->getParam(I)) && 426 S.hasVisibleDefaultArgument( 427 DTD->getTemplateParameters()->getParam(I))) 428 return true; 429 } 430 } 431 432 // VarDecl can have incomplete array types, prefer the one with more complete 433 // array type. 434 if (VarDecl *DVD = dyn_cast<VarDecl>(DUnderlying)) { 435 VarDecl *EVD = cast<VarDecl>(EUnderlying); 436 if (EVD->getType()->isIncompleteType() && 437 !DVD->getType()->isIncompleteType()) { 438 // Prefer the decl with a more complete type if visible. 439 return S.isVisible(DVD); 440 } 441 return false; // Avoid picking up a newer decl, just because it was newer. 442 } 443 444 // For most kinds of declaration, it doesn't really matter which one we pick. 445 if (!isa<FunctionDecl>(DUnderlying) && !isa<VarDecl>(DUnderlying)) { 446 // If the existing declaration is hidden, prefer the new one. Otherwise, 447 // keep what we've got. 448 return !S.isVisible(Existing); 449 } 450 451 // Pick the newer declaration; it might have a more precise type. 452 for (Decl *Prev = DUnderlying->getPreviousDecl(); Prev; 453 Prev = Prev->getPreviousDecl()) 454 if (Prev == EUnderlying) 455 return true; 456 return false; 457 } 458 459 /// Determine whether \p D can hide a tag declaration. 460 static bool canHideTag(NamedDecl *D) { 461 // C++ [basic.scope.declarative]p4: 462 // Given a set of declarations in a single declarative region [...] 463 // exactly one declaration shall declare a class name or enumeration name 464 // that is not a typedef name and the other declarations shall all refer to 465 // the same variable, non-static data member, or enumerator, or all refer 466 // to functions and function templates; in this case the class name or 467 // enumeration name is hidden. 468 // C++ [basic.scope.hiding]p2: 469 // A class name or enumeration name can be hidden by the name of a 470 // variable, data member, function, or enumerator declared in the same 471 // scope. 472 // An UnresolvedUsingValueDecl always instantiates to one of these. 473 D = D->getUnderlyingDecl(); 474 return isa<VarDecl>(D) || isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D) || 475 isa<FunctionTemplateDecl>(D) || isa<FieldDecl>(D) || 476 isa<UnresolvedUsingValueDecl>(D); 477 } 478 479 /// Resolves the result kind of this lookup. 480 void LookupResult::resolveKind() { 481 unsigned N = Decls.size(); 482 483 // Fast case: no possible ambiguity. 484 if (N == 0) { 485 assert(ResultKind == NotFound || 486 ResultKind == NotFoundInCurrentInstantiation); 487 return; 488 } 489 490 // If there's a single decl, we need to examine it to decide what 491 // kind of lookup this is. 492 if (N == 1) { 493 NamedDecl *D = (*Decls.begin())->getUnderlyingDecl(); 494 if (isa<FunctionTemplateDecl>(D)) 495 ResultKind = FoundOverloaded; 496 else if (isa<UnresolvedUsingValueDecl>(D)) 497 ResultKind = FoundUnresolvedValue; 498 return; 499 } 500 501 // Don't do any extra resolution if we've already resolved as ambiguous. 502 if (ResultKind == Ambiguous) return; 503 504 llvm::SmallDenseMap<NamedDecl*, unsigned, 16> Unique; 505 llvm::SmallDenseMap<QualType, unsigned, 16> UniqueTypes; 506 507 bool Ambiguous = false; 508 bool HasTag = false, HasFunction = false; 509 bool HasFunctionTemplate = false, HasUnresolved = false; 510 NamedDecl *HasNonFunction = nullptr; 511 512 llvm::SmallVector<NamedDecl*, 4> EquivalentNonFunctions; 513 514 unsigned UniqueTagIndex = 0; 515 516 unsigned I = 0; 517 while (I < N) { 518 NamedDecl *D = Decls[I]->getUnderlyingDecl(); 519 D = cast<NamedDecl>(D->getCanonicalDecl()); 520 521 // Ignore an invalid declaration unless it's the only one left. 522 if (D->isInvalidDecl() && !(I == 0 && N == 1)) { 523 Decls[I] = Decls[--N]; 524 continue; 525 } 526 527 llvm::Optional<unsigned> ExistingI; 528 529 // Redeclarations of types via typedef can occur both within a scope 530 // and, through using declarations and directives, across scopes. There is 531 // no ambiguity if they all refer to the same type, so unique based on the 532 // canonical type. 533 if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) { 534 QualType T = getSema().Context.getTypeDeclType(TD); 535 auto UniqueResult = UniqueTypes.insert( 536 std::make_pair(getSema().Context.getCanonicalType(T), I)); 537 if (!UniqueResult.second) { 538 // The type is not unique. 539 ExistingI = UniqueResult.first->second; 540 } 541 } 542 543 // For non-type declarations, check for a prior lookup result naming this 544 // canonical declaration. 545 if (!ExistingI) { 546 auto UniqueResult = Unique.insert(std::make_pair(D, I)); 547 if (!UniqueResult.second) { 548 // We've seen this entity before. 549 ExistingI = UniqueResult.first->second; 550 } 551 } 552 553 if (ExistingI) { 554 // This is not a unique lookup result. Pick one of the results and 555 // discard the other. 556 if (isPreferredLookupResult(getSema(), getLookupKind(), Decls[I], 557 Decls[*ExistingI])) 558 Decls[*ExistingI] = Decls[I]; 559 Decls[I] = Decls[--N]; 560 continue; 561 } 562 563 // Otherwise, do some decl type analysis and then continue. 564 565 if (isa<UnresolvedUsingValueDecl>(D)) { 566 HasUnresolved = true; 567 } else if (isa<TagDecl>(D)) { 568 if (HasTag) 569 Ambiguous = true; 570 UniqueTagIndex = I; 571 HasTag = true; 572 } else if (isa<FunctionTemplateDecl>(D)) { 573 HasFunction = true; 574 HasFunctionTemplate = true; 575 } else if (isa<FunctionDecl>(D)) { 576 HasFunction = true; 577 } else { 578 if (HasNonFunction) { 579 // If we're about to create an ambiguity between two declarations that 580 // are equivalent, but one is an internal linkage declaration from one 581 // module and the other is an internal linkage declaration from another 582 // module, just skip it. 583 if (getSema().isEquivalentInternalLinkageDeclaration(HasNonFunction, 584 D)) { 585 EquivalentNonFunctions.push_back(D); 586 Decls[I] = Decls[--N]; 587 continue; 588 } 589 590 Ambiguous = true; 591 } 592 HasNonFunction = D; 593 } 594 I++; 595 } 596 597 // C++ [basic.scope.hiding]p2: 598 // A class name or enumeration name can be hidden by the name of 599 // an object, function, or enumerator declared in the same 600 // scope. If a class or enumeration name and an object, function, 601 // or enumerator are declared in the same scope (in any order) 602 // with the same name, the class or enumeration name is hidden 603 // wherever the object, function, or enumerator name is visible. 604 // But it's still an error if there are distinct tag types found, 605 // even if they're not visible. (ref?) 606 if (N > 1 && HideTags && HasTag && !Ambiguous && 607 (HasFunction || HasNonFunction || HasUnresolved)) { 608 NamedDecl *OtherDecl = Decls[UniqueTagIndex ? 0 : N - 1]; 609 if (isa<TagDecl>(Decls[UniqueTagIndex]->getUnderlyingDecl()) && 610 getContextForScopeMatching(Decls[UniqueTagIndex])->Equals( 611 getContextForScopeMatching(OtherDecl)) && 612 canHideTag(OtherDecl)) 613 Decls[UniqueTagIndex] = Decls[--N]; 614 else 615 Ambiguous = true; 616 } 617 618 // FIXME: This diagnostic should really be delayed until we're done with 619 // the lookup result, in case the ambiguity is resolved by the caller. 620 if (!EquivalentNonFunctions.empty() && !Ambiguous) 621 getSema().diagnoseEquivalentInternalLinkageDeclarations( 622 getNameLoc(), HasNonFunction, EquivalentNonFunctions); 623 624 Decls.truncate(N); 625 626 if (HasNonFunction && (HasFunction || HasUnresolved)) 627 Ambiguous = true; 628 629 if (Ambiguous) 630 setAmbiguous(LookupResult::AmbiguousReference); 631 else if (HasUnresolved) 632 ResultKind = LookupResult::FoundUnresolvedValue; 633 else if (N > 1 || HasFunctionTemplate) 634 ResultKind = LookupResult::FoundOverloaded; 635 else 636 ResultKind = LookupResult::Found; 637 } 638 639 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) { 640 CXXBasePaths::const_paths_iterator I, E; 641 for (I = P.begin(), E = P.end(); I != E; ++I) 642 for (DeclContext::lookup_iterator DI = I->Decls, DE = DI.end(); DI != DE; 643 ++DI) 644 addDecl(*DI); 645 } 646 647 void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) { 648 Paths = new CXXBasePaths; 649 Paths->swap(P); 650 addDeclsFromBasePaths(*Paths); 651 resolveKind(); 652 setAmbiguous(AmbiguousBaseSubobjects); 653 } 654 655 void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) { 656 Paths = new CXXBasePaths; 657 Paths->swap(P); 658 addDeclsFromBasePaths(*Paths); 659 resolveKind(); 660 setAmbiguous(AmbiguousBaseSubobjectTypes); 661 } 662 663 void LookupResult::print(raw_ostream &Out) { 664 Out << Decls.size() << " result(s)"; 665 if (isAmbiguous()) Out << ", ambiguous"; 666 if (Paths) Out << ", base paths present"; 667 668 for (iterator I = begin(), E = end(); I != E; ++I) { 669 Out << "\n"; 670 (*I)->print(Out, 2); 671 } 672 } 673 674 LLVM_DUMP_METHOD void LookupResult::dump() { 675 llvm::errs() << "lookup results for " << getLookupName().getAsString() 676 << ":\n"; 677 for (NamedDecl *D : *this) 678 D->dump(); 679 } 680 681 /// Diagnose a missing builtin type. 682 static QualType diagOpenCLBuiltinTypeError(Sema &S, llvm::StringRef TypeClass, 683 llvm::StringRef Name) { 684 S.Diag(SourceLocation(), diag::err_opencl_type_not_found) 685 << TypeClass << Name; 686 return S.Context.VoidTy; 687 } 688 689 /// Lookup an OpenCL enum type. 690 static QualType getOpenCLEnumType(Sema &S, llvm::StringRef Name) { 691 LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(), 692 Sema::LookupTagName); 693 S.LookupName(Result, S.TUScope); 694 if (Result.empty()) 695 return diagOpenCLBuiltinTypeError(S, "enum", Name); 696 EnumDecl *Decl = Result.getAsSingle<EnumDecl>(); 697 if (!Decl) 698 return diagOpenCLBuiltinTypeError(S, "enum", Name); 699 return S.Context.getEnumType(Decl); 700 } 701 702 /// Lookup an OpenCL typedef type. 703 static QualType getOpenCLTypedefType(Sema &S, llvm::StringRef Name) { 704 LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(), 705 Sema::LookupOrdinaryName); 706 S.LookupName(Result, S.TUScope); 707 if (Result.empty()) 708 return diagOpenCLBuiltinTypeError(S, "typedef", Name); 709 TypedefNameDecl *Decl = Result.getAsSingle<TypedefNameDecl>(); 710 if (!Decl) 711 return diagOpenCLBuiltinTypeError(S, "typedef", Name); 712 return S.Context.getTypedefType(Decl); 713 } 714 715 /// Get the QualType instances of the return type and arguments for an OpenCL 716 /// builtin function signature. 717 /// \param S (in) The Sema instance. 718 /// \param OpenCLBuiltin (in) The signature currently handled. 719 /// \param GenTypeMaxCnt (out) Maximum number of types contained in a generic 720 /// type used as return type or as argument. 721 /// Only meaningful for generic types, otherwise equals 1. 722 /// \param RetTypes (out) List of the possible return types. 723 /// \param ArgTypes (out) List of the possible argument types. For each 724 /// argument, ArgTypes contains QualTypes for the Cartesian product 725 /// of (vector sizes) x (types) . 726 static void GetQualTypesForOpenCLBuiltin( 727 Sema &S, const OpenCLBuiltinStruct &OpenCLBuiltin, unsigned &GenTypeMaxCnt, 728 SmallVector<QualType, 1> &RetTypes, 729 SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) { 730 // Get the QualType instances of the return types. 731 unsigned Sig = SignatureTable[OpenCLBuiltin.SigTableIndex]; 732 OCL2Qual(S, TypeTable[Sig], RetTypes); 733 GenTypeMaxCnt = RetTypes.size(); 734 735 // Get the QualType instances of the arguments. 736 // First type is the return type, skip it. 737 for (unsigned Index = 1; Index < OpenCLBuiltin.NumTypes; Index++) { 738 SmallVector<QualType, 1> Ty; 739 OCL2Qual(S, TypeTable[SignatureTable[OpenCLBuiltin.SigTableIndex + Index]], 740 Ty); 741 GenTypeMaxCnt = (Ty.size() > GenTypeMaxCnt) ? Ty.size() : GenTypeMaxCnt; 742 ArgTypes.push_back(std::move(Ty)); 743 } 744 } 745 746 /// Create a list of the candidate function overloads for an OpenCL builtin 747 /// function. 748 /// \param Context (in) The ASTContext instance. 749 /// \param GenTypeMaxCnt (in) Maximum number of types contained in a generic 750 /// type used as return type or as argument. 751 /// Only meaningful for generic types, otherwise equals 1. 752 /// \param FunctionList (out) List of FunctionTypes. 753 /// \param RetTypes (in) List of the possible return types. 754 /// \param ArgTypes (in) List of the possible types for the arguments. 755 static void GetOpenCLBuiltinFctOverloads( 756 ASTContext &Context, unsigned GenTypeMaxCnt, 757 std::vector<QualType> &FunctionList, SmallVector<QualType, 1> &RetTypes, 758 SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) { 759 FunctionProtoType::ExtProtoInfo PI( 760 Context.getDefaultCallingConvention(false, false, true)); 761 PI.Variadic = false; 762 763 // Do not attempt to create any FunctionTypes if there are no return types, 764 // which happens when a type belongs to a disabled extension. 765 if (RetTypes.size() == 0) 766 return; 767 768 // Create FunctionTypes for each (gen)type. 769 for (unsigned IGenType = 0; IGenType < GenTypeMaxCnt; IGenType++) { 770 SmallVector<QualType, 5> ArgList; 771 772 for (unsigned A = 0; A < ArgTypes.size(); A++) { 773 // Bail out if there is an argument that has no available types. 774 if (ArgTypes[A].size() == 0) 775 return; 776 777 // Builtins such as "max" have an "sgentype" argument that represents 778 // the corresponding scalar type of a gentype. The number of gentypes 779 // must be a multiple of the number of sgentypes. 780 assert(GenTypeMaxCnt % ArgTypes[A].size() == 0 && 781 "argument type count not compatible with gentype type count"); 782 unsigned Idx = IGenType % ArgTypes[A].size(); 783 ArgList.push_back(ArgTypes[A][Idx]); 784 } 785 786 FunctionList.push_back(Context.getFunctionType( 787 RetTypes[(RetTypes.size() != 1) ? IGenType : 0], ArgList, PI)); 788 } 789 } 790 791 /// When trying to resolve a function name, if isOpenCLBuiltin() returns a 792 /// non-null <Index, Len> pair, then the name is referencing an OpenCL 793 /// builtin function. Add all candidate signatures to the LookUpResult. 794 /// 795 /// \param S (in) The Sema instance. 796 /// \param LR (inout) The LookupResult instance. 797 /// \param II (in) The identifier being resolved. 798 /// \param FctIndex (in) Starting index in the BuiltinTable. 799 /// \param Len (in) The signature list has Len elements. 800 static void InsertOCLBuiltinDeclarationsFromTable(Sema &S, LookupResult &LR, 801 IdentifierInfo *II, 802 const unsigned FctIndex, 803 const unsigned Len) { 804 // The builtin function declaration uses generic types (gentype). 805 bool HasGenType = false; 806 807 // Maximum number of types contained in a generic type used as return type or 808 // as argument. Only meaningful for generic types, otherwise equals 1. 809 unsigned GenTypeMaxCnt; 810 811 ASTContext &Context = S.Context; 812 813 for (unsigned SignatureIndex = 0; SignatureIndex < Len; SignatureIndex++) { 814 const OpenCLBuiltinStruct &OpenCLBuiltin = 815 BuiltinTable[FctIndex + SignatureIndex]; 816 817 // Ignore this builtin function if it is not available in the currently 818 // selected language version. 819 if (!isOpenCLVersionContainedInMask(Context.getLangOpts(), 820 OpenCLBuiltin.Versions)) 821 continue; 822 823 // Ignore this builtin function if it carries an extension macro that is 824 // not defined. This indicates that the extension is not supported by the 825 // target, so the builtin function should not be available. 826 StringRef Extensions = FunctionExtensionTable[OpenCLBuiltin.Extension]; 827 if (!Extensions.empty()) { 828 SmallVector<StringRef, 2> ExtVec; 829 Extensions.split(ExtVec, " "); 830 bool AllExtensionsDefined = true; 831 for (StringRef Ext : ExtVec) { 832 if (!S.getPreprocessor().isMacroDefined(Ext)) { 833 AllExtensionsDefined = false; 834 break; 835 } 836 } 837 if (!AllExtensionsDefined) 838 continue; 839 } 840 841 SmallVector<QualType, 1> RetTypes; 842 SmallVector<SmallVector<QualType, 1>, 5> ArgTypes; 843 844 // Obtain QualType lists for the function signature. 845 GetQualTypesForOpenCLBuiltin(S, OpenCLBuiltin, GenTypeMaxCnt, RetTypes, 846 ArgTypes); 847 if (GenTypeMaxCnt > 1) { 848 HasGenType = true; 849 } 850 851 // Create function overload for each type combination. 852 std::vector<QualType> FunctionList; 853 GetOpenCLBuiltinFctOverloads(Context, GenTypeMaxCnt, FunctionList, RetTypes, 854 ArgTypes); 855 856 SourceLocation Loc = LR.getNameLoc(); 857 DeclContext *Parent = Context.getTranslationUnitDecl(); 858 FunctionDecl *NewOpenCLBuiltin; 859 860 for (const auto &FTy : FunctionList) { 861 NewOpenCLBuiltin = FunctionDecl::Create( 862 Context, Parent, Loc, Loc, II, FTy, /*TInfo=*/nullptr, SC_Extern, 863 S.getCurFPFeatures().isFPConstrained(), false, 864 FTy->isFunctionProtoType()); 865 NewOpenCLBuiltin->setImplicit(); 866 867 // Create Decl objects for each parameter, adding them to the 868 // FunctionDecl. 869 const auto *FP = cast<FunctionProtoType>(FTy); 870 SmallVector<ParmVarDecl *, 4> ParmList; 871 for (unsigned IParm = 0, e = FP->getNumParams(); IParm != e; ++IParm) { 872 ParmVarDecl *Parm = ParmVarDecl::Create( 873 Context, NewOpenCLBuiltin, SourceLocation(), SourceLocation(), 874 nullptr, FP->getParamType(IParm), nullptr, SC_None, nullptr); 875 Parm->setScopeInfo(0, IParm); 876 ParmList.push_back(Parm); 877 } 878 NewOpenCLBuiltin->setParams(ParmList); 879 880 // Add function attributes. 881 if (OpenCLBuiltin.IsPure) 882 NewOpenCLBuiltin->addAttr(PureAttr::CreateImplicit(Context)); 883 if (OpenCLBuiltin.IsConst) 884 NewOpenCLBuiltin->addAttr(ConstAttr::CreateImplicit(Context)); 885 if (OpenCLBuiltin.IsConv) 886 NewOpenCLBuiltin->addAttr(ConvergentAttr::CreateImplicit(Context)); 887 888 if (!S.getLangOpts().OpenCLCPlusPlus) 889 NewOpenCLBuiltin->addAttr(OverloadableAttr::CreateImplicit(Context)); 890 891 LR.addDecl(NewOpenCLBuiltin); 892 } 893 } 894 895 // If we added overloads, need to resolve the lookup result. 896 if (Len > 1 || HasGenType) 897 LR.resolveKind(); 898 } 899 900 /// Lookup a builtin function, when name lookup would otherwise 901 /// fail. 902 bool Sema::LookupBuiltin(LookupResult &R) { 903 Sema::LookupNameKind NameKind = R.getLookupKind(); 904 905 // If we didn't find a use of this identifier, and if the identifier 906 // corresponds to a compiler builtin, create the decl object for the builtin 907 // now, injecting it into translation unit scope, and return it. 908 if (NameKind == Sema::LookupOrdinaryName || 909 NameKind == Sema::LookupRedeclarationWithLinkage) { 910 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo(); 911 if (II) { 912 if (getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName) { 913 if (II == getASTContext().getMakeIntegerSeqName()) { 914 R.addDecl(getASTContext().getMakeIntegerSeqDecl()); 915 return true; 916 } else if (II == getASTContext().getTypePackElementName()) { 917 R.addDecl(getASTContext().getTypePackElementDecl()); 918 return true; 919 } 920 } 921 922 // Check if this is an OpenCL Builtin, and if so, insert its overloads. 923 if (getLangOpts().OpenCL && getLangOpts().DeclareOpenCLBuiltins) { 924 auto Index = isOpenCLBuiltin(II->getName()); 925 if (Index.first) { 926 InsertOCLBuiltinDeclarationsFromTable(*this, R, II, Index.first - 1, 927 Index.second); 928 return true; 929 } 930 } 931 932 if (DeclareRISCVVBuiltins) { 933 if (!RVIntrinsicManager) 934 RVIntrinsicManager = CreateRISCVIntrinsicManager(*this); 935 936 if (RVIntrinsicManager->CreateIntrinsicIfFound(R, II, PP)) 937 return true; 938 } 939 940 // If this is a builtin on this (or all) targets, create the decl. 941 if (unsigned BuiltinID = II->getBuiltinID()) { 942 // In C++ and OpenCL (spec v1.2 s6.9.f), we don't have any predefined 943 // library functions like 'malloc'. Instead, we'll just error. 944 if ((getLangOpts().CPlusPlus || getLangOpts().OpenCL) && 945 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 946 return false; 947 948 if (NamedDecl *D = 949 LazilyCreateBuiltin(II, BuiltinID, TUScope, 950 R.isForRedeclaration(), R.getNameLoc())) { 951 R.addDecl(D); 952 return true; 953 } 954 } 955 } 956 } 957 958 return false; 959 } 960 961 /// Looks up the declaration of "struct objc_super" and 962 /// saves it for later use in building builtin declaration of 963 /// objc_msgSendSuper and objc_msgSendSuper_stret. 964 static void LookupPredefedObjCSuperType(Sema &Sema, Scope *S) { 965 ASTContext &Context = Sema.Context; 966 LookupResult Result(Sema, &Context.Idents.get("objc_super"), SourceLocation(), 967 Sema::LookupTagName); 968 Sema.LookupName(Result, S); 969 if (Result.getResultKind() == LookupResult::Found) 970 if (const TagDecl *TD = Result.getAsSingle<TagDecl>()) 971 Context.setObjCSuperType(Context.getTagDeclType(TD)); 972 } 973 974 void Sema::LookupNecessaryTypesForBuiltin(Scope *S, unsigned ID) { 975 if (ID == Builtin::BIobjc_msgSendSuper) 976 LookupPredefedObjCSuperType(*this, S); 977 } 978 979 /// Determine whether we can declare a special member function within 980 /// the class at this point. 981 static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) { 982 // We need to have a definition for the class. 983 if (!Class->getDefinition() || Class->isDependentContext()) 984 return false; 985 986 // We can't be in the middle of defining the class. 987 return !Class->isBeingDefined(); 988 } 989 990 void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) { 991 if (!CanDeclareSpecialMemberFunction(Class)) 992 return; 993 994 // If the default constructor has not yet been declared, do so now. 995 if (Class->needsImplicitDefaultConstructor()) 996 DeclareImplicitDefaultConstructor(Class); 997 998 // If the copy constructor has not yet been declared, do so now. 999 if (Class->needsImplicitCopyConstructor()) 1000 DeclareImplicitCopyConstructor(Class); 1001 1002 // If the copy assignment operator has not yet been declared, do so now. 1003 if (Class->needsImplicitCopyAssignment()) 1004 DeclareImplicitCopyAssignment(Class); 1005 1006 if (getLangOpts().CPlusPlus11) { 1007 // If the move constructor has not yet been declared, do so now. 1008 if (Class->needsImplicitMoveConstructor()) 1009 DeclareImplicitMoveConstructor(Class); 1010 1011 // If the move assignment operator has not yet been declared, do so now. 1012 if (Class->needsImplicitMoveAssignment()) 1013 DeclareImplicitMoveAssignment(Class); 1014 } 1015 1016 // If the destructor has not yet been declared, do so now. 1017 if (Class->needsImplicitDestructor()) 1018 DeclareImplicitDestructor(Class); 1019 } 1020 1021 /// Determine whether this is the name of an implicitly-declared 1022 /// special member function. 1023 static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) { 1024 switch (Name.getNameKind()) { 1025 case DeclarationName::CXXConstructorName: 1026 case DeclarationName::CXXDestructorName: 1027 return true; 1028 1029 case DeclarationName::CXXOperatorName: 1030 return Name.getCXXOverloadedOperator() == OO_Equal; 1031 1032 default: 1033 break; 1034 } 1035 1036 return false; 1037 } 1038 1039 /// If there are any implicit member functions with the given name 1040 /// that need to be declared in the given declaration context, do so. 1041 static void DeclareImplicitMemberFunctionsWithName(Sema &S, 1042 DeclarationName Name, 1043 SourceLocation Loc, 1044 const DeclContext *DC) { 1045 if (!DC) 1046 return; 1047 1048 switch (Name.getNameKind()) { 1049 case DeclarationName::CXXConstructorName: 1050 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) 1051 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) { 1052 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record); 1053 if (Record->needsImplicitDefaultConstructor()) 1054 S.DeclareImplicitDefaultConstructor(Class); 1055 if (Record->needsImplicitCopyConstructor()) 1056 S.DeclareImplicitCopyConstructor(Class); 1057 if (S.getLangOpts().CPlusPlus11 && 1058 Record->needsImplicitMoveConstructor()) 1059 S.DeclareImplicitMoveConstructor(Class); 1060 } 1061 break; 1062 1063 case DeclarationName::CXXDestructorName: 1064 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) 1065 if (Record->getDefinition() && Record->needsImplicitDestructor() && 1066 CanDeclareSpecialMemberFunction(Record)) 1067 S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record)); 1068 break; 1069 1070 case DeclarationName::CXXOperatorName: 1071 if (Name.getCXXOverloadedOperator() != OO_Equal) 1072 break; 1073 1074 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) { 1075 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) { 1076 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record); 1077 if (Record->needsImplicitCopyAssignment()) 1078 S.DeclareImplicitCopyAssignment(Class); 1079 if (S.getLangOpts().CPlusPlus11 && 1080 Record->needsImplicitMoveAssignment()) 1081 S.DeclareImplicitMoveAssignment(Class); 1082 } 1083 } 1084 break; 1085 1086 case DeclarationName::CXXDeductionGuideName: 1087 S.DeclareImplicitDeductionGuides(Name.getCXXDeductionGuideTemplate(), Loc); 1088 break; 1089 1090 default: 1091 break; 1092 } 1093 } 1094 1095 // Adds all qualifying matches for a name within a decl context to the 1096 // given lookup result. Returns true if any matches were found. 1097 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) { 1098 bool Found = false; 1099 1100 // Lazily declare C++ special member functions. 1101 if (S.getLangOpts().CPlusPlus) 1102 DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), R.getNameLoc(), 1103 DC); 1104 1105 // Perform lookup into this declaration context. 1106 DeclContext::lookup_result DR = DC->lookup(R.getLookupName()); 1107 for (NamedDecl *D : DR) { 1108 if ((D = R.getAcceptableDecl(D))) { 1109 R.addDecl(D); 1110 Found = true; 1111 } 1112 } 1113 1114 if (!Found && DC->isTranslationUnit() && S.LookupBuiltin(R)) 1115 return true; 1116 1117 if (R.getLookupName().getNameKind() 1118 != DeclarationName::CXXConversionFunctionName || 1119 R.getLookupName().getCXXNameType()->isDependentType() || 1120 !isa<CXXRecordDecl>(DC)) 1121 return Found; 1122 1123 // C++ [temp.mem]p6: 1124 // A specialization of a conversion function template is not found by 1125 // name lookup. Instead, any conversion function templates visible in the 1126 // context of the use are considered. [...] 1127 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC); 1128 if (!Record->isCompleteDefinition()) 1129 return Found; 1130 1131 // For conversion operators, 'operator auto' should only match 1132 // 'operator auto'. Since 'auto' is not a type, it shouldn't be considered 1133 // as a candidate for template substitution. 1134 auto *ContainedDeducedType = 1135 R.getLookupName().getCXXNameType()->getContainedDeducedType(); 1136 if (R.getLookupName().getNameKind() == 1137 DeclarationName::CXXConversionFunctionName && 1138 ContainedDeducedType && ContainedDeducedType->isUndeducedType()) 1139 return Found; 1140 1141 for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(), 1142 UEnd = Record->conversion_end(); U != UEnd; ++U) { 1143 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U); 1144 if (!ConvTemplate) 1145 continue; 1146 1147 // When we're performing lookup for the purposes of redeclaration, just 1148 // add the conversion function template. When we deduce template 1149 // arguments for specializations, we'll end up unifying the return 1150 // type of the new declaration with the type of the function template. 1151 if (R.isForRedeclaration()) { 1152 R.addDecl(ConvTemplate); 1153 Found = true; 1154 continue; 1155 } 1156 1157 // C++ [temp.mem]p6: 1158 // [...] For each such operator, if argument deduction succeeds 1159 // (14.9.2.3), the resulting specialization is used as if found by 1160 // name lookup. 1161 // 1162 // When referencing a conversion function for any purpose other than 1163 // a redeclaration (such that we'll be building an expression with the 1164 // result), perform template argument deduction and place the 1165 // specialization into the result set. We do this to avoid forcing all 1166 // callers to perform special deduction for conversion functions. 1167 TemplateDeductionInfo Info(R.getNameLoc()); 1168 FunctionDecl *Specialization = nullptr; 1169 1170 const FunctionProtoType *ConvProto 1171 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>(); 1172 assert(ConvProto && "Nonsensical conversion function template type"); 1173 1174 // Compute the type of the function that we would expect the conversion 1175 // function to have, if it were to match the name given. 1176 // FIXME: Calling convention! 1177 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo(); 1178 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C); 1179 EPI.ExceptionSpec = EST_None; 1180 QualType ExpectedType 1181 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(), 1182 None, EPI); 1183 1184 // Perform template argument deduction against the type that we would 1185 // expect the function to have. 1186 if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType, 1187 Specialization, Info) 1188 == Sema::TDK_Success) { 1189 R.addDecl(Specialization); 1190 Found = true; 1191 } 1192 } 1193 1194 return Found; 1195 } 1196 1197 // Performs C++ unqualified lookup into the given file context. 1198 static bool 1199 CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context, 1200 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) { 1201 1202 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!"); 1203 1204 // Perform direct name lookup into the LookupCtx. 1205 bool Found = LookupDirect(S, R, NS); 1206 1207 // Perform direct name lookup into the namespaces nominated by the 1208 // using directives whose common ancestor is this namespace. 1209 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS)) 1210 if (LookupDirect(S, R, UUE.getNominatedNamespace())) 1211 Found = true; 1212 1213 R.resolveKind(); 1214 1215 return Found; 1216 } 1217 1218 static bool isNamespaceOrTranslationUnitScope(Scope *S) { 1219 if (DeclContext *Ctx = S->getEntity()) 1220 return Ctx->isFileContext(); 1221 return false; 1222 } 1223 1224 /// Find the outer declaration context from this scope. This indicates the 1225 /// context that we should search up to (exclusive) before considering the 1226 /// parent of the specified scope. 1227 static DeclContext *findOuterContext(Scope *S) { 1228 for (Scope *OuterS = S->getParent(); OuterS; OuterS = OuterS->getParent()) 1229 if (DeclContext *DC = OuterS->getLookupEntity()) 1230 return DC; 1231 return nullptr; 1232 } 1233 1234 namespace { 1235 /// An RAII object to specify that we want to find block scope extern 1236 /// declarations. 1237 struct FindLocalExternScope { 1238 FindLocalExternScope(LookupResult &R) 1239 : R(R), OldFindLocalExtern(R.getIdentifierNamespace() & 1240 Decl::IDNS_LocalExtern) { 1241 R.setFindLocalExtern(R.getIdentifierNamespace() & 1242 (Decl::IDNS_Ordinary | Decl::IDNS_NonMemberOperator)); 1243 } 1244 void restore() { 1245 R.setFindLocalExtern(OldFindLocalExtern); 1246 } 1247 ~FindLocalExternScope() { 1248 restore(); 1249 } 1250 LookupResult &R; 1251 bool OldFindLocalExtern; 1252 }; 1253 } // end anonymous namespace 1254 1255 bool Sema::CppLookupName(LookupResult &R, Scope *S) { 1256 assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup"); 1257 1258 DeclarationName Name = R.getLookupName(); 1259 Sema::LookupNameKind NameKind = R.getLookupKind(); 1260 1261 // If this is the name of an implicitly-declared special member function, 1262 // go through the scope stack to implicitly declare 1263 if (isImplicitlyDeclaredMemberFunctionName(Name)) { 1264 for (Scope *PreS = S; PreS; PreS = PreS->getParent()) 1265 if (DeclContext *DC = PreS->getEntity()) 1266 DeclareImplicitMemberFunctionsWithName(*this, Name, R.getNameLoc(), DC); 1267 } 1268 1269 // Implicitly declare member functions with the name we're looking for, if in 1270 // fact we are in a scope where it matters. 1271 1272 Scope *Initial = S; 1273 IdentifierResolver::iterator 1274 I = IdResolver.begin(Name), 1275 IEnd = IdResolver.end(); 1276 1277 // First we lookup local scope. 1278 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir] 1279 // ...During unqualified name lookup (3.4.1), the names appear as if 1280 // they were declared in the nearest enclosing namespace which contains 1281 // both the using-directive and the nominated namespace. 1282 // [Note: in this context, "contains" means "contains directly or 1283 // indirectly". 1284 // 1285 // For example: 1286 // namespace A { int i; } 1287 // void foo() { 1288 // int i; 1289 // { 1290 // using namespace A; 1291 // ++i; // finds local 'i', A::i appears at global scope 1292 // } 1293 // } 1294 // 1295 UnqualUsingDirectiveSet UDirs(*this); 1296 bool VisitedUsingDirectives = false; 1297 bool LeftStartingScope = false; 1298 1299 // When performing a scope lookup, we want to find local extern decls. 1300 FindLocalExternScope FindLocals(R); 1301 1302 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) { 1303 bool SearchNamespaceScope = true; 1304 // Check whether the IdResolver has anything in this scope. 1305 for (; I != IEnd && S->isDeclScope(*I); ++I) { 1306 if (NamedDecl *ND = R.getAcceptableDecl(*I)) { 1307 if (NameKind == LookupRedeclarationWithLinkage && 1308 !(*I)->isTemplateParameter()) { 1309 // If it's a template parameter, we still find it, so we can diagnose 1310 // the invalid redeclaration. 1311 1312 // Determine whether this (or a previous) declaration is 1313 // out-of-scope. 1314 if (!LeftStartingScope && !Initial->isDeclScope(*I)) 1315 LeftStartingScope = true; 1316 1317 // If we found something outside of our starting scope that 1318 // does not have linkage, skip it. 1319 if (LeftStartingScope && !((*I)->hasLinkage())) { 1320 R.setShadowed(); 1321 continue; 1322 } 1323 } else { 1324 // We found something in this scope, we should not look at the 1325 // namespace scope 1326 SearchNamespaceScope = false; 1327 } 1328 R.addDecl(ND); 1329 } 1330 } 1331 if (!SearchNamespaceScope) { 1332 R.resolveKind(); 1333 if (S->isClassScope()) 1334 if (CXXRecordDecl *Record = 1335 dyn_cast_or_null<CXXRecordDecl>(S->getEntity())) 1336 R.setNamingClass(Record); 1337 return true; 1338 } 1339 1340 if (NameKind == LookupLocalFriendName && !S->isClassScope()) { 1341 // C++11 [class.friend]p11: 1342 // If a friend declaration appears in a local class and the name 1343 // specified is an unqualified name, a prior declaration is 1344 // looked up without considering scopes that are outside the 1345 // innermost enclosing non-class scope. 1346 return false; 1347 } 1348 1349 if (DeclContext *Ctx = S->getLookupEntity()) { 1350 DeclContext *OuterCtx = findOuterContext(S); 1351 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 1352 // We do not directly look into transparent contexts, since 1353 // those entities will be found in the nearest enclosing 1354 // non-transparent context. 1355 if (Ctx->isTransparentContext()) 1356 continue; 1357 1358 // We do not look directly into function or method contexts, 1359 // since all of the local variables and parameters of the 1360 // function/method are present within the Scope. 1361 if (Ctx->isFunctionOrMethod()) { 1362 // If we have an Objective-C instance method, look for ivars 1363 // in the corresponding interface. 1364 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 1365 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo()) 1366 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) { 1367 ObjCInterfaceDecl *ClassDeclared; 1368 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable( 1369 Name.getAsIdentifierInfo(), 1370 ClassDeclared)) { 1371 if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) { 1372 R.addDecl(ND); 1373 R.resolveKind(); 1374 return true; 1375 } 1376 } 1377 } 1378 } 1379 1380 continue; 1381 } 1382 1383 // If this is a file context, we need to perform unqualified name 1384 // lookup considering using directives. 1385 if (Ctx->isFileContext()) { 1386 // If we haven't handled using directives yet, do so now. 1387 if (!VisitedUsingDirectives) { 1388 // Add using directives from this context up to the top level. 1389 for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) { 1390 if (UCtx->isTransparentContext()) 1391 continue; 1392 1393 UDirs.visit(UCtx, UCtx); 1394 } 1395 1396 // Find the innermost file scope, so we can add using directives 1397 // from local scopes. 1398 Scope *InnermostFileScope = S; 1399 while (InnermostFileScope && 1400 !isNamespaceOrTranslationUnitScope(InnermostFileScope)) 1401 InnermostFileScope = InnermostFileScope->getParent(); 1402 UDirs.visitScopeChain(Initial, InnermostFileScope); 1403 1404 UDirs.done(); 1405 1406 VisitedUsingDirectives = true; 1407 } 1408 1409 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) { 1410 R.resolveKind(); 1411 return true; 1412 } 1413 1414 continue; 1415 } 1416 1417 // Perform qualified name lookup into this context. 1418 // FIXME: In some cases, we know that every name that could be found by 1419 // this qualified name lookup will also be on the identifier chain. For 1420 // example, inside a class without any base classes, we never need to 1421 // perform qualified lookup because all of the members are on top of the 1422 // identifier chain. 1423 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true)) 1424 return true; 1425 } 1426 } 1427 } 1428 1429 // Stop if we ran out of scopes. 1430 // FIXME: This really, really shouldn't be happening. 1431 if (!S) return false; 1432 1433 // If we are looking for members, no need to look into global/namespace scope. 1434 if (NameKind == LookupMemberName) 1435 return false; 1436 1437 // Collect UsingDirectiveDecls in all scopes, and recursively all 1438 // nominated namespaces by those using-directives. 1439 // 1440 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we 1441 // don't build it for each lookup! 1442 if (!VisitedUsingDirectives) { 1443 UDirs.visitScopeChain(Initial, S); 1444 UDirs.done(); 1445 } 1446 1447 // If we're not performing redeclaration lookup, do not look for local 1448 // extern declarations outside of a function scope. 1449 if (!R.isForRedeclaration()) 1450 FindLocals.restore(); 1451 1452 // Lookup namespace scope, and global scope. 1453 // Unqualified name lookup in C++ requires looking into scopes 1454 // that aren't strictly lexical, and therefore we walk through the 1455 // context as well as walking through the scopes. 1456 for (; S; S = S->getParent()) { 1457 // Check whether the IdResolver has anything in this scope. 1458 bool Found = false; 1459 for (; I != IEnd && S->isDeclScope(*I); ++I) { 1460 if (NamedDecl *ND = R.getAcceptableDecl(*I)) { 1461 // We found something. Look for anything else in our scope 1462 // with this same name and in an acceptable identifier 1463 // namespace, so that we can construct an overload set if we 1464 // need to. 1465 Found = true; 1466 R.addDecl(ND); 1467 } 1468 } 1469 1470 if (Found && S->isTemplateParamScope()) { 1471 R.resolveKind(); 1472 return true; 1473 } 1474 1475 DeclContext *Ctx = S->getLookupEntity(); 1476 if (Ctx) { 1477 DeclContext *OuterCtx = findOuterContext(S); 1478 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { 1479 // We do not directly look into transparent contexts, since 1480 // those entities will be found in the nearest enclosing 1481 // non-transparent context. 1482 if (Ctx->isTransparentContext()) 1483 continue; 1484 1485 // If we have a context, and it's not a context stashed in the 1486 // template parameter scope for an out-of-line definition, also 1487 // look into that context. 1488 if (!(Found && S->isTemplateParamScope())) { 1489 assert(Ctx->isFileContext() && 1490 "We should have been looking only at file context here already."); 1491 1492 // Look into context considering using-directives. 1493 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) 1494 Found = true; 1495 } 1496 1497 if (Found) { 1498 R.resolveKind(); 1499 return true; 1500 } 1501 1502 if (R.isForRedeclaration() && !Ctx->isTransparentContext()) 1503 return false; 1504 } 1505 } 1506 1507 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext()) 1508 return false; 1509 } 1510 1511 return !R.empty(); 1512 } 1513 1514 void Sema::makeMergedDefinitionVisible(NamedDecl *ND) { 1515 if (auto *M = getCurrentModule()) 1516 Context.mergeDefinitionIntoModule(ND, M); 1517 else 1518 // We're not building a module; just make the definition visible. 1519 ND->setVisibleDespiteOwningModule(); 1520 1521 // If ND is a template declaration, make the template parameters 1522 // visible too. They're not (necessarily) within a mergeable DeclContext. 1523 if (auto *TD = dyn_cast<TemplateDecl>(ND)) 1524 for (auto *Param : *TD->getTemplateParameters()) 1525 makeMergedDefinitionVisible(Param); 1526 } 1527 1528 /// Find the module in which the given declaration was defined. 1529 static Module *getDefiningModule(Sema &S, Decl *Entity) { 1530 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) { 1531 // If this function was instantiated from a template, the defining module is 1532 // the module containing the pattern. 1533 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern()) 1534 Entity = Pattern; 1535 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) { 1536 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern()) 1537 Entity = Pattern; 1538 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) { 1539 if (auto *Pattern = ED->getTemplateInstantiationPattern()) 1540 Entity = Pattern; 1541 } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) { 1542 if (VarDecl *Pattern = VD->getTemplateInstantiationPattern()) 1543 Entity = Pattern; 1544 } 1545 1546 // Walk up to the containing context. That might also have been instantiated 1547 // from a template. 1548 DeclContext *Context = Entity->getLexicalDeclContext(); 1549 if (Context->isFileContext()) 1550 return S.getOwningModule(Entity); 1551 return getDefiningModule(S, cast<Decl>(Context)); 1552 } 1553 1554 llvm::DenseSet<Module*> &Sema::getLookupModules() { 1555 unsigned N = CodeSynthesisContexts.size(); 1556 for (unsigned I = CodeSynthesisContextLookupModules.size(); 1557 I != N; ++I) { 1558 Module *M = CodeSynthesisContexts[I].Entity ? 1559 getDefiningModule(*this, CodeSynthesisContexts[I].Entity) : 1560 nullptr; 1561 if (M && !LookupModulesCache.insert(M).second) 1562 M = nullptr; 1563 CodeSynthesisContextLookupModules.push_back(M); 1564 } 1565 return LookupModulesCache; 1566 } 1567 1568 /// Determine if we could use all the declarations in the module. 1569 bool Sema::isUsableModule(const Module *M) { 1570 assert(M && "We shouldn't check nullness for module here"); 1571 // Return quickly if we cached the result. 1572 if (UsableModuleUnitsCache.count(M)) 1573 return true; 1574 1575 // If M is the global module fragment of the current translation unit. So it 1576 // should be usable. 1577 // [module.global.frag]p1: 1578 // The global module fragment can be used to provide declarations that are 1579 // attached to the global module and usable within the module unit. 1580 if (M == GlobalModuleFragment || 1581 // If M is the module we're parsing, it should be usable. This covers the 1582 // private module fragment. The private module fragment is usable only if 1583 // it is within the current module unit. And it must be the current 1584 // parsing module unit if it is within the current module unit according 1585 // to the grammar of the private module fragment. NOTE: This is covered by 1586 // the following condition. The intention of the check is to avoid string 1587 // comparison as much as possible. 1588 M == getCurrentModule() || 1589 // The module unit which is in the same module with the current module 1590 // unit is usable. 1591 // 1592 // FIXME: Here we judge if they are in the same module by comparing the 1593 // string. Is there any better solution? 1594 M->getPrimaryModuleInterfaceName() == 1595 llvm::StringRef(getLangOpts().CurrentModule).split(':').first) { 1596 UsableModuleUnitsCache.insert(M); 1597 return true; 1598 } 1599 1600 return false; 1601 } 1602 1603 bool Sema::hasVisibleMergedDefinition(NamedDecl *Def) { 1604 for (const Module *Merged : Context.getModulesWithMergedDefinition(Def)) 1605 if (isModuleVisible(Merged)) 1606 return true; 1607 return false; 1608 } 1609 1610 bool Sema::hasMergedDefinitionInCurrentModule(NamedDecl *Def) { 1611 for (const Module *Merged : Context.getModulesWithMergedDefinition(Def)) 1612 if (isUsableModule(Merged)) 1613 return true; 1614 return false; 1615 } 1616 1617 template <typename ParmDecl> 1618 static bool 1619 hasAcceptableDefaultArgument(Sema &S, const ParmDecl *D, 1620 llvm::SmallVectorImpl<Module *> *Modules, 1621 Sema::AcceptableKind Kind) { 1622 if (!D->hasDefaultArgument()) 1623 return false; 1624 1625 llvm::SmallDenseSet<const ParmDecl *, 4> Visited; 1626 while (D && !Visited.count(D)) { 1627 Visited.insert(D); 1628 1629 auto &DefaultArg = D->getDefaultArgStorage(); 1630 if (!DefaultArg.isInherited() && S.isAcceptable(D, Kind)) 1631 return true; 1632 1633 if (!DefaultArg.isInherited() && Modules) { 1634 auto *NonConstD = const_cast<ParmDecl*>(D); 1635 Modules->push_back(S.getOwningModule(NonConstD)); 1636 } 1637 1638 // If there was a previous default argument, maybe its parameter is 1639 // acceptable. 1640 D = DefaultArg.getInheritedFrom(); 1641 } 1642 return false; 1643 } 1644 1645 bool Sema::hasAcceptableDefaultArgument( 1646 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules, 1647 Sema::AcceptableKind Kind) { 1648 if (auto *P = dyn_cast<TemplateTypeParmDecl>(D)) 1649 return ::hasAcceptableDefaultArgument(*this, P, Modules, Kind); 1650 1651 if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D)) 1652 return ::hasAcceptableDefaultArgument(*this, P, Modules, Kind); 1653 1654 return ::hasAcceptableDefaultArgument( 1655 *this, cast<TemplateTemplateParmDecl>(D), Modules, Kind); 1656 } 1657 1658 bool Sema::hasVisibleDefaultArgument(const NamedDecl *D, 1659 llvm::SmallVectorImpl<Module *> *Modules) { 1660 return hasAcceptableDefaultArgument(D, Modules, 1661 Sema::AcceptableKind::Visible); 1662 } 1663 1664 bool Sema::hasReachableDefaultArgument( 1665 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1666 return hasAcceptableDefaultArgument(D, Modules, 1667 Sema::AcceptableKind::Reachable); 1668 } 1669 1670 template <typename Filter> 1671 static bool 1672 hasAcceptableDeclarationImpl(Sema &S, const NamedDecl *D, 1673 llvm::SmallVectorImpl<Module *> *Modules, Filter F, 1674 Sema::AcceptableKind Kind) { 1675 bool HasFilteredRedecls = false; 1676 1677 for (auto *Redecl : D->redecls()) { 1678 auto *R = cast<NamedDecl>(Redecl); 1679 if (!F(R)) 1680 continue; 1681 1682 if (S.isAcceptable(R, Kind)) 1683 return true; 1684 1685 HasFilteredRedecls = true; 1686 1687 if (Modules) 1688 Modules->push_back(R->getOwningModule()); 1689 } 1690 1691 // Only return false if there is at least one redecl that is not filtered out. 1692 if (HasFilteredRedecls) 1693 return false; 1694 1695 return true; 1696 } 1697 1698 static bool 1699 hasAcceptableExplicitSpecialization(Sema &S, const NamedDecl *D, 1700 llvm::SmallVectorImpl<Module *> *Modules, 1701 Sema::AcceptableKind Kind) { 1702 return hasAcceptableDeclarationImpl( 1703 S, D, Modules, 1704 [](const NamedDecl *D) { 1705 if (auto *RD = dyn_cast<CXXRecordDecl>(D)) 1706 return RD->getTemplateSpecializationKind() == 1707 TSK_ExplicitSpecialization; 1708 if (auto *FD = dyn_cast<FunctionDecl>(D)) 1709 return FD->getTemplateSpecializationKind() == 1710 TSK_ExplicitSpecialization; 1711 if (auto *VD = dyn_cast<VarDecl>(D)) 1712 return VD->getTemplateSpecializationKind() == 1713 TSK_ExplicitSpecialization; 1714 llvm_unreachable("unknown explicit specialization kind"); 1715 }, 1716 Kind); 1717 } 1718 1719 bool Sema::hasVisibleExplicitSpecialization( 1720 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1721 return ::hasAcceptableExplicitSpecialization(*this, D, Modules, 1722 Sema::AcceptableKind::Visible); 1723 } 1724 1725 bool Sema::hasReachableExplicitSpecialization( 1726 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1727 return ::hasAcceptableExplicitSpecialization(*this, D, Modules, 1728 Sema::AcceptableKind::Reachable); 1729 } 1730 1731 static bool 1732 hasAcceptableMemberSpecialization(Sema &S, const NamedDecl *D, 1733 llvm::SmallVectorImpl<Module *> *Modules, 1734 Sema::AcceptableKind Kind) { 1735 assert(isa<CXXRecordDecl>(D->getDeclContext()) && 1736 "not a member specialization"); 1737 return hasAcceptableDeclarationImpl( 1738 S, D, Modules, 1739 [](const NamedDecl *D) { 1740 // If the specialization is declared at namespace scope, then it's a 1741 // member specialization declaration. If it's lexically inside the class 1742 // definition then it was instantiated. 1743 // 1744 // FIXME: This is a hack. There should be a better way to determine 1745 // this. 1746 // FIXME: What about MS-style explicit specializations declared within a 1747 // class definition? 1748 return D->getLexicalDeclContext()->isFileContext(); 1749 }, 1750 Kind); 1751 } 1752 1753 bool Sema::hasVisibleMemberSpecialization( 1754 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1755 return hasAcceptableMemberSpecialization(*this, D, Modules, 1756 Sema::AcceptableKind::Visible); 1757 } 1758 1759 bool Sema::hasReachableMemberSpecialization( 1760 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 1761 return hasAcceptableMemberSpecialization(*this, D, Modules, 1762 Sema::AcceptableKind::Reachable); 1763 } 1764 1765 /// Determine whether a declaration is acceptable to name lookup. 1766 /// 1767 /// This routine determines whether the declaration D is acceptable in the 1768 /// current lookup context, taking into account the current template 1769 /// instantiation stack. During template instantiation, a declaration is 1770 /// acceptable if it is acceptable from a module containing any entity on the 1771 /// template instantiation path (by instantiating a template, you allow it to 1772 /// see the declarations that your module can see, including those later on in 1773 /// your module). 1774 bool LookupResult::isAcceptableSlow(Sema &SemaRef, NamedDecl *D, 1775 Sema::AcceptableKind Kind) { 1776 assert(!D->isUnconditionallyVisible() && 1777 "should not call this: not in slow case"); 1778 1779 Module *DeclModule = SemaRef.getOwningModule(D); 1780 assert(DeclModule && "hidden decl has no owning module"); 1781 1782 // If the owning module is visible, the decl is acceptable. 1783 if (SemaRef.isModuleVisible(DeclModule, 1784 D->isInvisibleOutsideTheOwningModule())) 1785 return true; 1786 1787 // Determine whether a decl context is a file context for the purpose of 1788 // visibility/reachability. This looks through some (export and linkage spec) 1789 // transparent contexts, but not others (enums). 1790 auto IsEffectivelyFileContext = [](const DeclContext *DC) { 1791 return DC->isFileContext() || isa<LinkageSpecDecl>(DC) || 1792 isa<ExportDecl>(DC); 1793 }; 1794 1795 // If this declaration is not at namespace scope 1796 // then it is acceptable if its lexical parent has a acceptable definition. 1797 DeclContext *DC = D->getLexicalDeclContext(); 1798 if (DC && !IsEffectivelyFileContext(DC)) { 1799 // For a parameter, check whether our current template declaration's 1800 // lexical context is acceptable, not whether there's some other acceptable 1801 // definition of it, because parameters aren't "within" the definition. 1802 // 1803 // In C++ we need to check for a acceptable definition due to ODR merging, 1804 // and in C we must not because each declaration of a function gets its own 1805 // set of declarations for tags in prototype scope. 1806 bool AcceptableWithinParent; 1807 if (D->isTemplateParameter()) { 1808 bool SearchDefinitions = true; 1809 if (const auto *DCD = dyn_cast<Decl>(DC)) { 1810 if (const auto *TD = DCD->getDescribedTemplate()) { 1811 TemplateParameterList *TPL = TD->getTemplateParameters(); 1812 auto Index = getDepthAndIndex(D).second; 1813 SearchDefinitions = Index >= TPL->size() || TPL->getParam(Index) != D; 1814 } 1815 } 1816 if (SearchDefinitions) 1817 AcceptableWithinParent = 1818 SemaRef.hasAcceptableDefinition(cast<NamedDecl>(DC), Kind); 1819 else 1820 AcceptableWithinParent = 1821 isAcceptable(SemaRef, cast<NamedDecl>(DC), Kind); 1822 } else if (isa<ParmVarDecl>(D) || 1823 (isa<FunctionDecl>(DC) && !SemaRef.getLangOpts().CPlusPlus)) 1824 AcceptableWithinParent = isAcceptable(SemaRef, cast<NamedDecl>(DC), Kind); 1825 else if (D->isModulePrivate()) { 1826 // A module-private declaration is only acceptable if an enclosing lexical 1827 // parent was merged with another definition in the current module. 1828 AcceptableWithinParent = false; 1829 do { 1830 if (SemaRef.hasMergedDefinitionInCurrentModule(cast<NamedDecl>(DC))) { 1831 AcceptableWithinParent = true; 1832 break; 1833 } 1834 DC = DC->getLexicalParent(); 1835 } while (!IsEffectivelyFileContext(DC)); 1836 } else { 1837 AcceptableWithinParent = 1838 SemaRef.hasAcceptableDefinition(cast<NamedDecl>(DC), Kind); 1839 } 1840 1841 if (AcceptableWithinParent && SemaRef.CodeSynthesisContexts.empty() && 1842 Kind == Sema::AcceptableKind::Visible && 1843 // FIXME: Do something better in this case. 1844 !SemaRef.getLangOpts().ModulesLocalVisibility) { 1845 // Cache the fact that this declaration is implicitly visible because 1846 // its parent has a visible definition. 1847 D->setVisibleDespiteOwningModule(); 1848 } 1849 return AcceptableWithinParent; 1850 } 1851 1852 if (Kind == Sema::AcceptableKind::Visible) 1853 return false; 1854 1855 assert(Kind == Sema::AcceptableKind::Reachable && 1856 "Additional Sema::AcceptableKind?"); 1857 return isReachableSlow(SemaRef, D); 1858 } 1859 1860 bool Sema::isModuleVisible(const Module *M, bool ModulePrivate) { 1861 // [module.global.frag]p2: 1862 // A global-module-fragment specifies the contents of the global module 1863 // fragment for a module unit. The global module fragment can be used to 1864 // provide declarations that are attached to the global module and usable 1865 // within the module unit. 1866 // 1867 // Global module fragment is special. Global Module fragment is only usable 1868 // within the module unit it got defined [module.global.frag]p2. So here we 1869 // check if the Module is the global module fragment in current translation 1870 // unit. 1871 if (M->isGlobalModule() && M != this->GlobalModuleFragment) 1872 return false; 1873 1874 // The module might be ordinarily visible. For a module-private query, that 1875 // means it is part of the current module. 1876 if (ModulePrivate && isUsableModule(M)) 1877 return true; 1878 1879 // For a query which is not module-private, that means it is in our visible 1880 // module set. 1881 if (!ModulePrivate && VisibleModules.isVisible(M)) 1882 return true; 1883 1884 // Otherwise, it might be visible by virtue of the query being within a 1885 // template instantiation or similar that is permitted to look inside M. 1886 1887 // Find the extra places where we need to look. 1888 const auto &LookupModules = getLookupModules(); 1889 if (LookupModules.empty()) 1890 return false; 1891 1892 // If our lookup set contains the module, it's visible. 1893 if (LookupModules.count(M)) 1894 return true; 1895 1896 // For a module-private query, that's everywhere we get to look. 1897 if (ModulePrivate) 1898 return false; 1899 1900 // Check whether M is transitively exported to an import of the lookup set. 1901 return llvm::any_of(LookupModules, [&](const Module *LookupM) { 1902 return LookupM->isModuleVisible(M); 1903 }); 1904 } 1905 1906 // FIXME: Return false directly if we don't have an interface dependency on the 1907 // translation unit containing D. 1908 bool LookupResult::isReachableSlow(Sema &SemaRef, NamedDecl *D) { 1909 assert(!isVisible(SemaRef, D) && "Shouldn't call the slow case.\n"); 1910 1911 Module *DeclModule = SemaRef.getOwningModule(D); 1912 assert(DeclModule && "hidden decl has no owning module"); 1913 1914 // Entities in module map modules are reachable only if they're visible. 1915 if (DeclModule->isModuleMapModule()) 1916 return false; 1917 1918 // If D comes from a module and SemaRef doesn't own a module, it implies D 1919 // comes from another TU. In case SemaRef owns a module, we could judge if D 1920 // comes from another TU by comparing the module unit. 1921 // 1922 // FIXME: It would look better if we have direct method to judge whether D is 1923 // in another TU. 1924 if (SemaRef.getCurrentModule() && 1925 SemaRef.getCurrentModule()->getTopLevelModule() == 1926 DeclModule->getTopLevelModule()) 1927 return true; 1928 1929 // [module.reach]/p3: 1930 // A declaration D is reachable from a point P if: 1931 // ... 1932 // - D is not discarded ([module.global.frag]), appears in a translation unit 1933 // that is reachable from P, and does not appear within a private module 1934 // fragment. 1935 // 1936 // A declaration that's discarded in the GMF should be module-private. 1937 if (D->isModulePrivate()) 1938 return false; 1939 1940 // [module.reach]/p1 1941 // A translation unit U is necessarily reachable from a point P if U is a 1942 // module interface unit on which the translation unit containing P has an 1943 // interface dependency, or the translation unit containing P imports U, in 1944 // either case prior to P ([module.import]). 1945 // 1946 // [module.import]/p10 1947 // A translation unit has an interface dependency on a translation unit U if 1948 // it contains a declaration (possibly a module-declaration) that imports U 1949 // or if it has an interface dependency on a translation unit that has an 1950 // interface dependency on U. 1951 // 1952 // So we could conclude the module unit U is necessarily reachable if: 1953 // (1) The module unit U is module interface unit. 1954 // (2) The current unit has an interface dependency on the module unit U. 1955 // 1956 // Here we only check for the first condition. Since we couldn't see 1957 // DeclModule if it isn't (transitively) imported. 1958 if (DeclModule->getTopLevelModule()->isModuleInterfaceUnit()) 1959 return true; 1960 1961 // [module.reach]/p2 1962 // Additional translation units on 1963 // which the point within the program has an interface dependency may be 1964 // considered reachable, but it is unspecified which are and under what 1965 // circumstances. 1966 // 1967 // The decision here is to treat all additional tranditional units as 1968 // unreachable. 1969 return false; 1970 } 1971 1972 bool Sema::isAcceptableSlow(const NamedDecl *D, Sema::AcceptableKind Kind) { 1973 return LookupResult::isAcceptable(*this, const_cast<NamedDecl *>(D), Kind); 1974 } 1975 1976 bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) { 1977 // FIXME: If there are both visible and hidden declarations, we need to take 1978 // into account whether redeclaration is possible. Example: 1979 // 1980 // Non-imported module: 1981 // int f(T); // #1 1982 // Some TU: 1983 // static int f(U); // #2, not a redeclaration of #1 1984 // int f(T); // #3, finds both, should link with #1 if T != U, but 1985 // // with #2 if T == U; neither should be ambiguous. 1986 for (auto *D : R) { 1987 if (isVisible(D)) 1988 return true; 1989 assert(D->isExternallyDeclarable() && 1990 "should not have hidden, non-externally-declarable result here"); 1991 } 1992 1993 // This function is called once "New" is essentially complete, but before a 1994 // previous declaration is attached. We can't query the linkage of "New" in 1995 // general, because attaching the previous declaration can change the 1996 // linkage of New to match the previous declaration. 1997 // 1998 // However, because we've just determined that there is no *visible* prior 1999 // declaration, we can compute the linkage here. There are two possibilities: 2000 // 2001 // * This is not a redeclaration; it's safe to compute the linkage now. 2002 // 2003 // * This is a redeclaration of a prior declaration that is externally 2004 // redeclarable. In that case, the linkage of the declaration is not 2005 // changed by attaching the prior declaration, because both are externally 2006 // declarable (and thus ExternalLinkage or VisibleNoLinkage). 2007 // 2008 // FIXME: This is subtle and fragile. 2009 return New->isExternallyDeclarable(); 2010 } 2011 2012 /// Retrieve the visible declaration corresponding to D, if any. 2013 /// 2014 /// This routine determines whether the declaration D is visible in the current 2015 /// module, with the current imports. If not, it checks whether any 2016 /// redeclaration of D is visible, and if so, returns that declaration. 2017 /// 2018 /// \returns D, or a visible previous declaration of D, whichever is more recent 2019 /// and visible. If no declaration of D is visible, returns null. 2020 static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D, 2021 unsigned IDNS) { 2022 assert(!LookupResult::isAvailableForLookup(SemaRef, D) && "not in slow case"); 2023 2024 for (auto RD : D->redecls()) { 2025 // Don't bother with extra checks if we already know this one isn't visible. 2026 if (RD == D) 2027 continue; 2028 2029 auto ND = cast<NamedDecl>(RD); 2030 // FIXME: This is wrong in the case where the previous declaration is not 2031 // visible in the same scope as D. This needs to be done much more 2032 // carefully. 2033 if (ND->isInIdentifierNamespace(IDNS) && 2034 LookupResult::isAvailableForLookup(SemaRef, ND)) 2035 return ND; 2036 } 2037 2038 return nullptr; 2039 } 2040 2041 bool Sema::hasVisibleDeclarationSlow(const NamedDecl *D, 2042 llvm::SmallVectorImpl<Module *> *Modules) { 2043 assert(!isVisible(D) && "not in slow case"); 2044 return hasAcceptableDeclarationImpl( 2045 *this, D, Modules, [](const NamedDecl *) { return true; }, 2046 Sema::AcceptableKind::Visible); 2047 } 2048 2049 bool Sema::hasReachableDeclarationSlow( 2050 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) { 2051 assert(!isReachable(D) && "not in slow case"); 2052 return hasAcceptableDeclarationImpl( 2053 *this, D, Modules, [](const NamedDecl *) { return true; }, 2054 Sema::AcceptableKind::Reachable); 2055 } 2056 2057 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const { 2058 if (auto *ND = dyn_cast<NamespaceDecl>(D)) { 2059 // Namespaces are a bit of a special case: we expect there to be a lot of 2060 // redeclarations of some namespaces, all declarations of a namespace are 2061 // essentially interchangeable, all declarations are found by name lookup 2062 // if any is, and namespaces are never looked up during template 2063 // instantiation. So we benefit from caching the check in this case, and 2064 // it is correct to do so. 2065 auto *Key = ND->getCanonicalDecl(); 2066 if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Key)) 2067 return Acceptable; 2068 auto *Acceptable = isVisible(getSema(), Key) 2069 ? Key 2070 : findAcceptableDecl(getSema(), Key, IDNS); 2071 if (Acceptable) 2072 getSema().VisibleNamespaceCache.insert(std::make_pair(Key, Acceptable)); 2073 return Acceptable; 2074 } 2075 2076 return findAcceptableDecl(getSema(), D, IDNS); 2077 } 2078 2079 bool LookupResult::isVisible(Sema &SemaRef, NamedDecl *D) { 2080 // If this declaration is already visible, return it directly. 2081 if (D->isUnconditionallyVisible()) 2082 return true; 2083 2084 // During template instantiation, we can refer to hidden declarations, if 2085 // they were visible in any module along the path of instantiation. 2086 return isAcceptableSlow(SemaRef, D, Sema::AcceptableKind::Visible); 2087 } 2088 2089 bool LookupResult::isReachable(Sema &SemaRef, NamedDecl *D) { 2090 if (D->isUnconditionallyVisible()) 2091 return true; 2092 2093 return isAcceptableSlow(SemaRef, D, Sema::AcceptableKind::Reachable); 2094 } 2095 2096 bool LookupResult::isAvailableForLookup(Sema &SemaRef, NamedDecl *ND) { 2097 // We should check the visibility at the callsite already. 2098 if (isVisible(SemaRef, ND)) 2099 return true; 2100 2101 // Deduction guide lives in namespace scope generally, but it is just a 2102 // hint to the compilers. What we actually lookup for is the generated member 2103 // of the corresponding template. So it is sufficient to check the 2104 // reachability of the template decl. 2105 if (auto *DeductionGuide = ND->getDeclName().getCXXDeductionGuideTemplate()) 2106 return SemaRef.hasReachableDefinition(DeductionGuide); 2107 2108 auto *DC = ND->getDeclContext(); 2109 // If ND is not visible and it is at namespace scope, it shouldn't be found 2110 // by name lookup. 2111 if (DC->isFileContext()) 2112 return false; 2113 2114 // [module.interface]p7 2115 // Class and enumeration member names can be found by name lookup in any 2116 // context in which a definition of the type is reachable. 2117 // 2118 // FIXME: The current implementation didn't consider about scope. For example, 2119 // ``` 2120 // // m.cppm 2121 // export module m; 2122 // enum E1 { e1 }; 2123 // // Use.cpp 2124 // import m; 2125 // void test() { 2126 // auto a = E1::e1; // Error as expected. 2127 // auto b = e1; // Should be error. namespace-scope name e1 is not visible 2128 // } 2129 // ``` 2130 // For the above example, the current implementation would emit error for `a` 2131 // correctly. However, the implementation wouldn't diagnose about `b` now. 2132 // Since we only check the reachability for the parent only. 2133 // See clang/test/CXX/module/module.interface/p7.cpp for example. 2134 if (auto *TD = dyn_cast<TagDecl>(DC)) 2135 return SemaRef.hasReachableDefinition(TD); 2136 2137 return false; 2138 } 2139 2140 /// Perform unqualified name lookup starting from a given 2141 /// scope. 2142 /// 2143 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is 2144 /// used to find names within the current scope. For example, 'x' in 2145 /// @code 2146 /// int x; 2147 /// int f() { 2148 /// return x; // unqualified name look finds 'x' in the global scope 2149 /// } 2150 /// @endcode 2151 /// 2152 /// Different lookup criteria can find different names. For example, a 2153 /// particular scope can have both a struct and a function of the same 2154 /// name, and each can be found by certain lookup criteria. For more 2155 /// information about lookup criteria, see the documentation for the 2156 /// class LookupCriteria. 2157 /// 2158 /// @param S The scope from which unqualified name lookup will 2159 /// begin. If the lookup criteria permits, name lookup may also search 2160 /// in the parent scopes. 2161 /// 2162 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to 2163 /// look up and the lookup kind), and is updated with the results of lookup 2164 /// including zero or more declarations and possibly additional information 2165 /// used to diagnose ambiguities. 2166 /// 2167 /// @returns \c true if lookup succeeded and false otherwise. 2168 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation, 2169 bool ForceNoCPlusPlus) { 2170 DeclarationName Name = R.getLookupName(); 2171 if (!Name) return false; 2172 2173 LookupNameKind NameKind = R.getLookupKind(); 2174 2175 if (!getLangOpts().CPlusPlus || ForceNoCPlusPlus) { 2176 // Unqualified name lookup in C/Objective-C is purely lexical, so 2177 // search in the declarations attached to the name. 2178 if (NameKind == Sema::LookupRedeclarationWithLinkage) { 2179 // Find the nearest non-transparent declaration scope. 2180 while (!(S->getFlags() & Scope::DeclScope) || 2181 (S->getEntity() && S->getEntity()->isTransparentContext())) 2182 S = S->getParent(); 2183 } 2184 2185 // When performing a scope lookup, we want to find local extern decls. 2186 FindLocalExternScope FindLocals(R); 2187 2188 // Scan up the scope chain looking for a decl that matches this 2189 // identifier that is in the appropriate namespace. This search 2190 // should not take long, as shadowing of names is uncommon, and 2191 // deep shadowing is extremely uncommon. 2192 bool LeftStartingScope = false; 2193 2194 for (IdentifierResolver::iterator I = IdResolver.begin(Name), 2195 IEnd = IdResolver.end(); 2196 I != IEnd; ++I) 2197 if (NamedDecl *D = R.getAcceptableDecl(*I)) { 2198 if (NameKind == LookupRedeclarationWithLinkage) { 2199 // Determine whether this (or a previous) declaration is 2200 // out-of-scope. 2201 if (!LeftStartingScope && !S->isDeclScope(*I)) 2202 LeftStartingScope = true; 2203 2204 // If we found something outside of our starting scope that 2205 // does not have linkage, skip it. 2206 if (LeftStartingScope && !((*I)->hasLinkage())) { 2207 R.setShadowed(); 2208 continue; 2209 } 2210 } 2211 else if (NameKind == LookupObjCImplicitSelfParam && 2212 !isa<ImplicitParamDecl>(*I)) 2213 continue; 2214 2215 R.addDecl(D); 2216 2217 // Check whether there are any other declarations with the same name 2218 // and in the same scope. 2219 if (I != IEnd) { 2220 // Find the scope in which this declaration was declared (if it 2221 // actually exists in a Scope). 2222 while (S && !S->isDeclScope(D)) 2223 S = S->getParent(); 2224 2225 // If the scope containing the declaration is the translation unit, 2226 // then we'll need to perform our checks based on the matching 2227 // DeclContexts rather than matching scopes. 2228 if (S && isNamespaceOrTranslationUnitScope(S)) 2229 S = nullptr; 2230 2231 // Compute the DeclContext, if we need it. 2232 DeclContext *DC = nullptr; 2233 if (!S) 2234 DC = (*I)->getDeclContext()->getRedeclContext(); 2235 2236 IdentifierResolver::iterator LastI = I; 2237 for (++LastI; LastI != IEnd; ++LastI) { 2238 if (S) { 2239 // Match based on scope. 2240 if (!S->isDeclScope(*LastI)) 2241 break; 2242 } else { 2243 // Match based on DeclContext. 2244 DeclContext *LastDC 2245 = (*LastI)->getDeclContext()->getRedeclContext(); 2246 if (!LastDC->Equals(DC)) 2247 break; 2248 } 2249 2250 // If the declaration is in the right namespace and visible, add it. 2251 if (NamedDecl *LastD = R.getAcceptableDecl(*LastI)) 2252 R.addDecl(LastD); 2253 } 2254 2255 R.resolveKind(); 2256 } 2257 2258 return true; 2259 } 2260 } else { 2261 // Perform C++ unqualified name lookup. 2262 if (CppLookupName(R, S)) 2263 return true; 2264 } 2265 2266 // If we didn't find a use of this identifier, and if the identifier 2267 // corresponds to a compiler builtin, create the decl object for the builtin 2268 // now, injecting it into translation unit scope, and return it. 2269 if (AllowBuiltinCreation && LookupBuiltin(R)) 2270 return true; 2271 2272 // If we didn't find a use of this identifier, the ExternalSource 2273 // may be able to handle the situation. 2274 // Note: some lookup failures are expected! 2275 // See e.g. R.isForRedeclaration(). 2276 return (ExternalSource && ExternalSource->LookupUnqualified(R, S)); 2277 } 2278 2279 /// Perform qualified name lookup in the namespaces nominated by 2280 /// using directives by the given context. 2281 /// 2282 /// C++98 [namespace.qual]p2: 2283 /// Given X::m (where X is a user-declared namespace), or given \::m 2284 /// (where X is the global namespace), let S be the set of all 2285 /// declarations of m in X and in the transitive closure of all 2286 /// namespaces nominated by using-directives in X and its used 2287 /// namespaces, except that using-directives are ignored in any 2288 /// namespace, including X, directly containing one or more 2289 /// declarations of m. No namespace is searched more than once in 2290 /// the lookup of a name. If S is the empty set, the program is 2291 /// ill-formed. Otherwise, if S has exactly one member, or if the 2292 /// context of the reference is a using-declaration 2293 /// (namespace.udecl), S is the required set of declarations of 2294 /// m. Otherwise if the use of m is not one that allows a unique 2295 /// declaration to be chosen from S, the program is ill-formed. 2296 /// 2297 /// C++98 [namespace.qual]p5: 2298 /// During the lookup of a qualified namespace member name, if the 2299 /// lookup finds more than one declaration of the member, and if one 2300 /// declaration introduces a class name or enumeration name and the 2301 /// other declarations either introduce the same object, the same 2302 /// enumerator or a set of functions, the non-type name hides the 2303 /// class or enumeration name if and only if the declarations are 2304 /// from the same namespace; otherwise (the declarations are from 2305 /// different namespaces), the program is ill-formed. 2306 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R, 2307 DeclContext *StartDC) { 2308 assert(StartDC->isFileContext() && "start context is not a file context"); 2309 2310 // We have not yet looked into these namespaces, much less added 2311 // their "using-children" to the queue. 2312 SmallVector<NamespaceDecl*, 8> Queue; 2313 2314 // We have at least added all these contexts to the queue. 2315 llvm::SmallPtrSet<DeclContext*, 8> Visited; 2316 Visited.insert(StartDC); 2317 2318 // We have already looked into the initial namespace; seed the queue 2319 // with its using-children. 2320 for (auto *I : StartDC->using_directives()) { 2321 NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace(); 2322 if (S.isVisible(I) && Visited.insert(ND).second) 2323 Queue.push_back(ND); 2324 } 2325 2326 // The easiest way to implement the restriction in [namespace.qual]p5 2327 // is to check whether any of the individual results found a tag 2328 // and, if so, to declare an ambiguity if the final result is not 2329 // a tag. 2330 bool FoundTag = false; 2331 bool FoundNonTag = false; 2332 2333 LookupResult LocalR(LookupResult::Temporary, R); 2334 2335 bool Found = false; 2336 while (!Queue.empty()) { 2337 NamespaceDecl *ND = Queue.pop_back_val(); 2338 2339 // We go through some convolutions here to avoid copying results 2340 // between LookupResults. 2341 bool UseLocal = !R.empty(); 2342 LookupResult &DirectR = UseLocal ? LocalR : R; 2343 bool FoundDirect = LookupDirect(S, DirectR, ND); 2344 2345 if (FoundDirect) { 2346 // First do any local hiding. 2347 DirectR.resolveKind(); 2348 2349 // If the local result is a tag, remember that. 2350 if (DirectR.isSingleTagDecl()) 2351 FoundTag = true; 2352 else 2353 FoundNonTag = true; 2354 2355 // Append the local results to the total results if necessary. 2356 if (UseLocal) { 2357 R.addAllDecls(LocalR); 2358 LocalR.clear(); 2359 } 2360 } 2361 2362 // If we find names in this namespace, ignore its using directives. 2363 if (FoundDirect) { 2364 Found = true; 2365 continue; 2366 } 2367 2368 for (auto I : ND->using_directives()) { 2369 NamespaceDecl *Nom = I->getNominatedNamespace(); 2370 if (S.isVisible(I) && Visited.insert(Nom).second) 2371 Queue.push_back(Nom); 2372 } 2373 } 2374 2375 if (Found) { 2376 if (FoundTag && FoundNonTag) 2377 R.setAmbiguousQualifiedTagHiding(); 2378 else 2379 R.resolveKind(); 2380 } 2381 2382 return Found; 2383 } 2384 2385 /// Perform qualified name lookup into a given context. 2386 /// 2387 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find 2388 /// names when the context of those names is explicit specified, e.g., 2389 /// "std::vector" or "x->member", or as part of unqualified name lookup. 2390 /// 2391 /// Different lookup criteria can find different names. For example, a 2392 /// particular scope can have both a struct and a function of the same 2393 /// name, and each can be found by certain lookup criteria. For more 2394 /// information about lookup criteria, see the documentation for the 2395 /// class LookupCriteria. 2396 /// 2397 /// \param R captures both the lookup criteria and any lookup results found. 2398 /// 2399 /// \param LookupCtx The context in which qualified name lookup will 2400 /// search. If the lookup criteria permits, name lookup may also search 2401 /// in the parent contexts or (for C++ classes) base classes. 2402 /// 2403 /// \param InUnqualifiedLookup true if this is qualified name lookup that 2404 /// occurs as part of unqualified name lookup. 2405 /// 2406 /// \returns true if lookup succeeded, false if it failed. 2407 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 2408 bool InUnqualifiedLookup) { 2409 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context"); 2410 2411 if (!R.getLookupName()) 2412 return false; 2413 2414 // Make sure that the declaration context is complete. 2415 assert((!isa<TagDecl>(LookupCtx) || 2416 LookupCtx->isDependentContext() || 2417 cast<TagDecl>(LookupCtx)->isCompleteDefinition() || 2418 cast<TagDecl>(LookupCtx)->isBeingDefined()) && 2419 "Declaration context must already be complete!"); 2420 2421 struct QualifiedLookupInScope { 2422 bool oldVal; 2423 DeclContext *Context; 2424 // Set flag in DeclContext informing debugger that we're looking for qualified name 2425 QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) { 2426 oldVal = ctx->setUseQualifiedLookup(); 2427 } 2428 ~QualifiedLookupInScope() { 2429 Context->setUseQualifiedLookup(oldVal); 2430 } 2431 } QL(LookupCtx); 2432 2433 if (LookupDirect(*this, R, LookupCtx)) { 2434 R.resolveKind(); 2435 if (isa<CXXRecordDecl>(LookupCtx)) 2436 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx)); 2437 return true; 2438 } 2439 2440 // Don't descend into implied contexts for redeclarations. 2441 // C++98 [namespace.qual]p6: 2442 // In a declaration for a namespace member in which the 2443 // declarator-id is a qualified-id, given that the qualified-id 2444 // for the namespace member has the form 2445 // nested-name-specifier unqualified-id 2446 // the unqualified-id shall name a member of the namespace 2447 // designated by the nested-name-specifier. 2448 // See also [class.mfct]p5 and [class.static.data]p2. 2449 if (R.isForRedeclaration()) 2450 return false; 2451 2452 // If this is a namespace, look it up in the implied namespaces. 2453 if (LookupCtx->isFileContext()) 2454 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx); 2455 2456 // If this isn't a C++ class, we aren't allowed to look into base 2457 // classes, we're done. 2458 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx); 2459 if (!LookupRec || !LookupRec->getDefinition()) 2460 return false; 2461 2462 // We're done for lookups that can never succeed for C++ classes. 2463 if (R.getLookupKind() == LookupOperatorName || 2464 R.getLookupKind() == LookupNamespaceName || 2465 R.getLookupKind() == LookupObjCProtocolName || 2466 R.getLookupKind() == LookupLabel) 2467 return false; 2468 2469 // If we're performing qualified name lookup into a dependent class, 2470 // then we are actually looking into a current instantiation. If we have any 2471 // dependent base classes, then we either have to delay lookup until 2472 // template instantiation time (at which point all bases will be available) 2473 // or we have to fail. 2474 if (!InUnqualifiedLookup && LookupRec->isDependentContext() && 2475 LookupRec->hasAnyDependentBases()) { 2476 R.setNotFoundInCurrentInstantiation(); 2477 return false; 2478 } 2479 2480 // Perform lookup into our base classes. 2481 2482 DeclarationName Name = R.getLookupName(); 2483 unsigned IDNS = R.getIdentifierNamespace(); 2484 2485 // Look for this member in our base classes. 2486 auto BaseCallback = [Name, IDNS](const CXXBaseSpecifier *Specifier, 2487 CXXBasePath &Path) -> bool { 2488 CXXRecordDecl *BaseRecord = Specifier->getType()->getAsCXXRecordDecl(); 2489 // Drop leading non-matching lookup results from the declaration list so 2490 // we don't need to consider them again below. 2491 for (Path.Decls = BaseRecord->lookup(Name).begin(); 2492 Path.Decls != Path.Decls.end(); ++Path.Decls) { 2493 if ((*Path.Decls)->isInIdentifierNamespace(IDNS)) 2494 return true; 2495 } 2496 return false; 2497 }; 2498 2499 CXXBasePaths Paths; 2500 Paths.setOrigin(LookupRec); 2501 if (!LookupRec->lookupInBases(BaseCallback, Paths)) 2502 return false; 2503 2504 R.setNamingClass(LookupRec); 2505 2506 // C++ [class.member.lookup]p2: 2507 // [...] If the resulting set of declarations are not all from 2508 // sub-objects of the same type, or the set has a nonstatic member 2509 // and includes members from distinct sub-objects, there is an 2510 // ambiguity and the program is ill-formed. Otherwise that set is 2511 // the result of the lookup. 2512 QualType SubobjectType; 2513 int SubobjectNumber = 0; 2514 AccessSpecifier SubobjectAccess = AS_none; 2515 2516 // Check whether the given lookup result contains only static members. 2517 auto HasOnlyStaticMembers = [&](DeclContext::lookup_iterator Result) { 2518 for (DeclContext::lookup_iterator I = Result, E = I.end(); I != E; ++I) 2519 if ((*I)->isInIdentifierNamespace(IDNS) && (*I)->isCXXInstanceMember()) 2520 return false; 2521 return true; 2522 }; 2523 2524 bool TemplateNameLookup = R.isTemplateNameLookup(); 2525 2526 // Determine whether two sets of members contain the same members, as 2527 // required by C++ [class.member.lookup]p6. 2528 auto HasSameDeclarations = [&](DeclContext::lookup_iterator A, 2529 DeclContext::lookup_iterator B) { 2530 using Iterator = DeclContextLookupResult::iterator; 2531 using Result = const void *; 2532 2533 auto Next = [&](Iterator &It, Iterator End) -> Result { 2534 while (It != End) { 2535 NamedDecl *ND = *It++; 2536 if (!ND->isInIdentifierNamespace(IDNS)) 2537 continue; 2538 2539 // C++ [temp.local]p3: 2540 // A lookup that finds an injected-class-name (10.2) can result in 2541 // an ambiguity in certain cases (for example, if it is found in 2542 // more than one base class). If all of the injected-class-names 2543 // that are found refer to specializations of the same class 2544 // template, and if the name is used as a template-name, the 2545 // reference refers to the class template itself and not a 2546 // specialization thereof, and is not ambiguous. 2547 if (TemplateNameLookup) 2548 if (auto *TD = getAsTemplateNameDecl(ND)) 2549 ND = TD; 2550 2551 // C++ [class.member.lookup]p3: 2552 // type declarations (including injected-class-names) are replaced by 2553 // the types they designate 2554 if (const TypeDecl *TD = dyn_cast<TypeDecl>(ND->getUnderlyingDecl())) { 2555 QualType T = Context.getTypeDeclType(TD); 2556 return T.getCanonicalType().getAsOpaquePtr(); 2557 } 2558 2559 return ND->getUnderlyingDecl()->getCanonicalDecl(); 2560 } 2561 return nullptr; 2562 }; 2563 2564 // We'll often find the declarations are in the same order. Handle this 2565 // case (and the special case of only one declaration) efficiently. 2566 Iterator AIt = A, BIt = B, AEnd, BEnd; 2567 while (true) { 2568 Result AResult = Next(AIt, AEnd); 2569 Result BResult = Next(BIt, BEnd); 2570 if (!AResult && !BResult) 2571 return true; 2572 if (!AResult || !BResult) 2573 return false; 2574 if (AResult != BResult) { 2575 // Found a mismatch; carefully check both lists, accounting for the 2576 // possibility of declarations appearing more than once. 2577 llvm::SmallDenseMap<Result, bool, 32> AResults; 2578 for (; AResult; AResult = Next(AIt, AEnd)) 2579 AResults.insert({AResult, /*FoundInB*/false}); 2580 unsigned Found = 0; 2581 for (; BResult; BResult = Next(BIt, BEnd)) { 2582 auto It = AResults.find(BResult); 2583 if (It == AResults.end()) 2584 return false; 2585 if (!It->second) { 2586 It->second = true; 2587 ++Found; 2588 } 2589 } 2590 return AResults.size() == Found; 2591 } 2592 } 2593 }; 2594 2595 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); 2596 Path != PathEnd; ++Path) { 2597 const CXXBasePathElement &PathElement = Path->back(); 2598 2599 // Pick the best (i.e. most permissive i.e. numerically lowest) access 2600 // across all paths. 2601 SubobjectAccess = std::min(SubobjectAccess, Path->Access); 2602 2603 // Determine whether we're looking at a distinct sub-object or not. 2604 if (SubobjectType.isNull()) { 2605 // This is the first subobject we've looked at. Record its type. 2606 SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); 2607 SubobjectNumber = PathElement.SubobjectNumber; 2608 continue; 2609 } 2610 2611 if (SubobjectType != 2612 Context.getCanonicalType(PathElement.Base->getType())) { 2613 // We found members of the given name in two subobjects of 2614 // different types. If the declaration sets aren't the same, this 2615 // lookup is ambiguous. 2616 // 2617 // FIXME: The language rule says that this applies irrespective of 2618 // whether the sets contain only static members. 2619 if (HasOnlyStaticMembers(Path->Decls) && 2620 HasSameDeclarations(Paths.begin()->Decls, Path->Decls)) 2621 continue; 2622 2623 R.setAmbiguousBaseSubobjectTypes(Paths); 2624 return true; 2625 } 2626 2627 // FIXME: This language rule no longer exists. Checking for ambiguous base 2628 // subobjects should be done as part of formation of a class member access 2629 // expression (when converting the object parameter to the member's type). 2630 if (SubobjectNumber != PathElement.SubobjectNumber) { 2631 // We have a different subobject of the same type. 2632 2633 // C++ [class.member.lookup]p5: 2634 // A static member, a nested type or an enumerator defined in 2635 // a base class T can unambiguously be found even if an object 2636 // has more than one base class subobject of type T. 2637 if (HasOnlyStaticMembers(Path->Decls)) 2638 continue; 2639 2640 // We have found a nonstatic member name in multiple, distinct 2641 // subobjects. Name lookup is ambiguous. 2642 R.setAmbiguousBaseSubobjects(Paths); 2643 return true; 2644 } 2645 } 2646 2647 // Lookup in a base class succeeded; return these results. 2648 2649 for (DeclContext::lookup_iterator I = Paths.front().Decls, E = I.end(); 2650 I != E; ++I) { 2651 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess, 2652 (*I)->getAccess()); 2653 if (NamedDecl *ND = R.getAcceptableDecl(*I)) 2654 R.addDecl(ND, AS); 2655 } 2656 R.resolveKind(); 2657 return true; 2658 } 2659 2660 /// Performs qualified name lookup or special type of lookup for 2661 /// "__super::" scope specifier. 2662 /// 2663 /// This routine is a convenience overload meant to be called from contexts 2664 /// that need to perform a qualified name lookup with an optional C++ scope 2665 /// specifier that might require special kind of lookup. 2666 /// 2667 /// \param R captures both the lookup criteria and any lookup results found. 2668 /// 2669 /// \param LookupCtx The context in which qualified name lookup will 2670 /// search. 2671 /// 2672 /// \param SS An optional C++ scope-specifier. 2673 /// 2674 /// \returns true if lookup succeeded, false if it failed. 2675 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, 2676 CXXScopeSpec &SS) { 2677 auto *NNS = SS.getScopeRep(); 2678 if (NNS && NNS->getKind() == NestedNameSpecifier::Super) 2679 return LookupInSuper(R, NNS->getAsRecordDecl()); 2680 else 2681 2682 return LookupQualifiedName(R, LookupCtx); 2683 } 2684 2685 /// Performs name lookup for a name that was parsed in the 2686 /// source code, and may contain a C++ scope specifier. 2687 /// 2688 /// This routine is a convenience routine meant to be called from 2689 /// contexts that receive a name and an optional C++ scope specifier 2690 /// (e.g., "N::M::x"). It will then perform either qualified or 2691 /// unqualified name lookup (with LookupQualifiedName or LookupName, 2692 /// respectively) on the given name and return those results. It will 2693 /// perform a special type of lookup for "__super::" scope specifier. 2694 /// 2695 /// @param S The scope from which unqualified name lookup will 2696 /// begin. 2697 /// 2698 /// @param SS An optional C++ scope-specifier, e.g., "::N::M". 2699 /// 2700 /// @param EnteringContext Indicates whether we are going to enter the 2701 /// context of the scope-specifier SS (if present). 2702 /// 2703 /// @returns True if any decls were found (but possibly ambiguous) 2704 bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS, 2705 bool AllowBuiltinCreation, bool EnteringContext) { 2706 if (SS && SS->isInvalid()) { 2707 // When the scope specifier is invalid, don't even look for 2708 // anything. 2709 return false; 2710 } 2711 2712 if (SS && SS->isSet()) { 2713 NestedNameSpecifier *NNS = SS->getScopeRep(); 2714 if (NNS->getKind() == NestedNameSpecifier::Super) 2715 return LookupInSuper(R, NNS->getAsRecordDecl()); 2716 2717 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { 2718 // We have resolved the scope specifier to a particular declaration 2719 // contex, and will perform name lookup in that context. 2720 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC)) 2721 return false; 2722 2723 R.setContextRange(SS->getRange()); 2724 return LookupQualifiedName(R, DC); 2725 } 2726 2727 // We could not resolve the scope specified to a specific declaration 2728 // context, which means that SS refers to an unknown specialization. 2729 // Name lookup can't find anything in this case. 2730 R.setNotFoundInCurrentInstantiation(); 2731 R.setContextRange(SS->getRange()); 2732 return false; 2733 } 2734 2735 // Perform unqualified name lookup starting in the given scope. 2736 return LookupName(R, S, AllowBuiltinCreation); 2737 } 2738 2739 /// Perform qualified name lookup into all base classes of the given 2740 /// class. 2741 /// 2742 /// \param R captures both the lookup criteria and any lookup results found. 2743 /// 2744 /// \param Class The context in which qualified name lookup will 2745 /// search. Name lookup will search in all base classes merging the results. 2746 /// 2747 /// @returns True if any decls were found (but possibly ambiguous) 2748 bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) { 2749 // The access-control rules we use here are essentially the rules for 2750 // doing a lookup in Class that just magically skipped the direct 2751 // members of Class itself. That is, the naming class is Class, and the 2752 // access includes the access of the base. 2753 for (const auto &BaseSpec : Class->bases()) { 2754 CXXRecordDecl *RD = cast<CXXRecordDecl>( 2755 BaseSpec.getType()->castAs<RecordType>()->getDecl()); 2756 LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind()); 2757 Result.setBaseObjectType(Context.getRecordType(Class)); 2758 LookupQualifiedName(Result, RD); 2759 2760 // Copy the lookup results into the target, merging the base's access into 2761 // the path access. 2762 for (auto I = Result.begin(), E = Result.end(); I != E; ++I) { 2763 R.addDecl(I.getDecl(), 2764 CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(), 2765 I.getAccess())); 2766 } 2767 2768 Result.suppressDiagnostics(); 2769 } 2770 2771 R.resolveKind(); 2772 R.setNamingClass(Class); 2773 2774 return !R.empty(); 2775 } 2776 2777 /// Produce a diagnostic describing the ambiguity that resulted 2778 /// from name lookup. 2779 /// 2780 /// \param Result The result of the ambiguous lookup to be diagnosed. 2781 void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) { 2782 assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); 2783 2784 DeclarationName Name = Result.getLookupName(); 2785 SourceLocation NameLoc = Result.getNameLoc(); 2786 SourceRange LookupRange = Result.getContextRange(); 2787 2788 switch (Result.getAmbiguityKind()) { 2789 case LookupResult::AmbiguousBaseSubobjects: { 2790 CXXBasePaths *Paths = Result.getBasePaths(); 2791 QualType SubobjectType = Paths->front().back().Base->getType(); 2792 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) 2793 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) 2794 << LookupRange; 2795 2796 DeclContext::lookup_iterator Found = Paths->front().Decls; 2797 while (isa<CXXMethodDecl>(*Found) && 2798 cast<CXXMethodDecl>(*Found)->isStatic()) 2799 ++Found; 2800 2801 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); 2802 break; 2803 } 2804 2805 case LookupResult::AmbiguousBaseSubobjectTypes: { 2806 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) 2807 << Name << LookupRange; 2808 2809 CXXBasePaths *Paths = Result.getBasePaths(); 2810 std::set<const NamedDecl *> DeclsPrinted; 2811 for (CXXBasePaths::paths_iterator Path = Paths->begin(), 2812 PathEnd = Paths->end(); 2813 Path != PathEnd; ++Path) { 2814 const NamedDecl *D = *Path->Decls; 2815 if (!D->isInIdentifierNamespace(Result.getIdentifierNamespace())) 2816 continue; 2817 if (DeclsPrinted.insert(D).second) { 2818 if (const auto *TD = dyn_cast<TypedefNameDecl>(D->getUnderlyingDecl())) 2819 Diag(D->getLocation(), diag::note_ambiguous_member_type_found) 2820 << TD->getUnderlyingType(); 2821 else if (const auto *TD = dyn_cast<TypeDecl>(D->getUnderlyingDecl())) 2822 Diag(D->getLocation(), diag::note_ambiguous_member_type_found) 2823 << Context.getTypeDeclType(TD); 2824 else 2825 Diag(D->getLocation(), diag::note_ambiguous_member_found); 2826 } 2827 } 2828 break; 2829 } 2830 2831 case LookupResult::AmbiguousTagHiding: { 2832 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange; 2833 2834 llvm::SmallPtrSet<NamedDecl*, 8> TagDecls; 2835 2836 for (auto *D : Result) 2837 if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 2838 TagDecls.insert(TD); 2839 Diag(TD->getLocation(), diag::note_hidden_tag); 2840 } 2841 2842 for (auto *D : Result) 2843 if (!isa<TagDecl>(D)) 2844 Diag(D->getLocation(), diag::note_hiding_object); 2845 2846 // For recovery purposes, go ahead and implement the hiding. 2847 LookupResult::Filter F = Result.makeFilter(); 2848 while (F.hasNext()) { 2849 if (TagDecls.count(F.next())) 2850 F.erase(); 2851 } 2852 F.done(); 2853 break; 2854 } 2855 2856 case LookupResult::AmbiguousReference: { 2857 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; 2858 2859 for (auto *D : Result) 2860 Diag(D->getLocation(), diag::note_ambiguous_candidate) << D; 2861 break; 2862 } 2863 } 2864 } 2865 2866 namespace { 2867 struct AssociatedLookup { 2868 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc, 2869 Sema::AssociatedNamespaceSet &Namespaces, 2870 Sema::AssociatedClassSet &Classes) 2871 : S(S), Namespaces(Namespaces), Classes(Classes), 2872 InstantiationLoc(InstantiationLoc) { 2873 } 2874 2875 bool addClassTransitive(CXXRecordDecl *RD) { 2876 Classes.insert(RD); 2877 return ClassesTransitive.insert(RD); 2878 } 2879 2880 Sema &S; 2881 Sema::AssociatedNamespaceSet &Namespaces; 2882 Sema::AssociatedClassSet &Classes; 2883 SourceLocation InstantiationLoc; 2884 2885 private: 2886 Sema::AssociatedClassSet ClassesTransitive; 2887 }; 2888 } // end anonymous namespace 2889 2890 static void 2891 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T); 2892 2893 // Given the declaration context \param Ctx of a class, class template or 2894 // enumeration, add the associated namespaces to \param Namespaces as described 2895 // in [basic.lookup.argdep]p2. 2896 static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces, 2897 DeclContext *Ctx) { 2898 // The exact wording has been changed in C++14 as a result of 2899 // CWG 1691 (see also CWG 1690 and CWG 1692). We apply it unconditionally 2900 // to all language versions since it is possible to return a local type 2901 // from a lambda in C++11. 2902 // 2903 // C++14 [basic.lookup.argdep]p2: 2904 // If T is a class type [...]. Its associated namespaces are the innermost 2905 // enclosing namespaces of its associated classes. [...] 2906 // 2907 // If T is an enumeration type, its associated namespace is the innermost 2908 // enclosing namespace of its declaration. [...] 2909 2910 // We additionally skip inline namespaces. The innermost non-inline namespace 2911 // contains all names of all its nested inline namespaces anyway, so we can 2912 // replace the entire inline namespace tree with its root. 2913 while (!Ctx->isFileContext() || Ctx->isInlineNamespace()) 2914 Ctx = Ctx->getParent(); 2915 2916 Namespaces.insert(Ctx->getPrimaryContext()); 2917 } 2918 2919 // Add the associated classes and namespaces for argument-dependent 2920 // lookup that involves a template argument (C++ [basic.lookup.argdep]p2). 2921 static void 2922 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 2923 const TemplateArgument &Arg) { 2924 // C++ [basic.lookup.argdep]p2, last bullet: 2925 // -- [...] ; 2926 switch (Arg.getKind()) { 2927 case TemplateArgument::Null: 2928 break; 2929 2930 case TemplateArgument::Type: 2931 // [...] the namespaces and classes associated with the types of the 2932 // template arguments provided for template type parameters (excluding 2933 // template template parameters) 2934 addAssociatedClassesAndNamespaces(Result, Arg.getAsType()); 2935 break; 2936 2937 case TemplateArgument::Template: 2938 case TemplateArgument::TemplateExpansion: { 2939 // [...] the namespaces in which any template template arguments are 2940 // defined; and the classes in which any member templates used as 2941 // template template arguments are defined. 2942 TemplateName Template = Arg.getAsTemplateOrTemplatePattern(); 2943 if (ClassTemplateDecl *ClassTemplate 2944 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) { 2945 DeclContext *Ctx = ClassTemplate->getDeclContext(); 2946 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2947 Result.Classes.insert(EnclosingClass); 2948 // Add the associated namespace for this class. 2949 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2950 } 2951 break; 2952 } 2953 2954 case TemplateArgument::Declaration: 2955 case TemplateArgument::Integral: 2956 case TemplateArgument::Expression: 2957 case TemplateArgument::NullPtr: 2958 // [Note: non-type template arguments do not contribute to the set of 2959 // associated namespaces. ] 2960 break; 2961 2962 case TemplateArgument::Pack: 2963 for (const auto &P : Arg.pack_elements()) 2964 addAssociatedClassesAndNamespaces(Result, P); 2965 break; 2966 } 2967 } 2968 2969 // Add the associated classes and namespaces for argument-dependent lookup 2970 // with an argument of class type (C++ [basic.lookup.argdep]p2). 2971 static void 2972 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, 2973 CXXRecordDecl *Class) { 2974 2975 // Just silently ignore anything whose name is __va_list_tag. 2976 if (Class->getDeclName() == Result.S.VAListTagName) 2977 return; 2978 2979 // C++ [basic.lookup.argdep]p2: 2980 // [...] 2981 // -- If T is a class type (including unions), its associated 2982 // classes are: the class itself; the class of which it is a 2983 // member, if any; and its direct and indirect base classes. 2984 // Its associated namespaces are the innermost enclosing 2985 // namespaces of its associated classes. 2986 2987 // Add the class of which it is a member, if any. 2988 DeclContext *Ctx = Class->getDeclContext(); 2989 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 2990 Result.Classes.insert(EnclosingClass); 2991 2992 // Add the associated namespace for this class. 2993 CollectEnclosingNamespace(Result.Namespaces, Ctx); 2994 2995 // -- If T is a template-id, its associated namespaces and classes are 2996 // the namespace in which the template is defined; for member 2997 // templates, the member template's class; the namespaces and classes 2998 // associated with the types of the template arguments provided for 2999 // template type parameters (excluding template template parameters); the 3000 // namespaces in which any template template arguments are defined; and 3001 // the classes in which any member templates used as template template 3002 // arguments are defined. [Note: non-type template arguments do not 3003 // contribute to the set of associated namespaces. ] 3004 if (ClassTemplateSpecializationDecl *Spec 3005 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) { 3006 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); 3007 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 3008 Result.Classes.insert(EnclosingClass); 3009 // Add the associated namespace for this class. 3010 CollectEnclosingNamespace(Result.Namespaces, Ctx); 3011 3012 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); 3013 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 3014 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]); 3015 } 3016 3017 // Add the class itself. If we've already transitively visited this class, 3018 // we don't need to visit base classes. 3019 if (!Result.addClassTransitive(Class)) 3020 return; 3021 3022 // Only recurse into base classes for complete types. 3023 if (!Result.S.isCompleteType(Result.InstantiationLoc, 3024 Result.S.Context.getRecordType(Class))) 3025 return; 3026 3027 // Add direct and indirect base classes along with their associated 3028 // namespaces. 3029 SmallVector<CXXRecordDecl *, 32> Bases; 3030 Bases.push_back(Class); 3031 while (!Bases.empty()) { 3032 // Pop this class off the stack. 3033 Class = Bases.pop_back_val(); 3034 3035 // Visit the base classes. 3036 for (const auto &Base : Class->bases()) { 3037 const RecordType *BaseType = Base.getType()->getAs<RecordType>(); 3038 // In dependent contexts, we do ADL twice, and the first time around, 3039 // the base type might be a dependent TemplateSpecializationType, or a 3040 // TemplateTypeParmType. If that happens, simply ignore it. 3041 // FIXME: If we want to support export, we probably need to add the 3042 // namespace of the template in a TemplateSpecializationType, or even 3043 // the classes and namespaces of known non-dependent arguments. 3044 if (!BaseType) 3045 continue; 3046 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 3047 if (Result.addClassTransitive(BaseDecl)) { 3048 // Find the associated namespace for this base class. 3049 DeclContext *BaseCtx = BaseDecl->getDeclContext(); 3050 CollectEnclosingNamespace(Result.Namespaces, BaseCtx); 3051 3052 // Make sure we visit the bases of this base class. 3053 if (BaseDecl->bases_begin() != BaseDecl->bases_end()) 3054 Bases.push_back(BaseDecl); 3055 } 3056 } 3057 } 3058 } 3059 3060 // Add the associated classes and namespaces for 3061 // argument-dependent lookup with an argument of type T 3062 // (C++ [basic.lookup.koenig]p2). 3063 static void 3064 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) { 3065 // C++ [basic.lookup.koenig]p2: 3066 // 3067 // For each argument type T in the function call, there is a set 3068 // of zero or more associated namespaces and a set of zero or more 3069 // associated classes to be considered. The sets of namespaces and 3070 // classes is determined entirely by the types of the function 3071 // arguments (and the namespace of any template template 3072 // argument). Typedef names and using-declarations used to specify 3073 // the types do not contribute to this set. The sets of namespaces 3074 // and classes are determined in the following way: 3075 3076 SmallVector<const Type *, 16> Queue; 3077 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr(); 3078 3079 while (true) { 3080 switch (T->getTypeClass()) { 3081 3082 #define TYPE(Class, Base) 3083 #define DEPENDENT_TYPE(Class, Base) case Type::Class: 3084 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 3085 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class: 3086 #define ABSTRACT_TYPE(Class, Base) 3087 #include "clang/AST/TypeNodes.inc" 3088 // T is canonical. We can also ignore dependent types because 3089 // we don't need to do ADL at the definition point, but if we 3090 // wanted to implement template export (or if we find some other 3091 // use for associated classes and namespaces...) this would be 3092 // wrong. 3093 break; 3094 3095 // -- If T is a pointer to U or an array of U, its associated 3096 // namespaces and classes are those associated with U. 3097 case Type::Pointer: 3098 T = cast<PointerType>(T)->getPointeeType().getTypePtr(); 3099 continue; 3100 case Type::ConstantArray: 3101 case Type::IncompleteArray: 3102 case Type::VariableArray: 3103 T = cast<ArrayType>(T)->getElementType().getTypePtr(); 3104 continue; 3105 3106 // -- If T is a fundamental type, its associated sets of 3107 // namespaces and classes are both empty. 3108 case Type::Builtin: 3109 break; 3110 3111 // -- If T is a class type (including unions), its associated 3112 // classes are: the class itself; the class of which it is 3113 // a member, if any; and its direct and indirect base classes. 3114 // Its associated namespaces are the innermost enclosing 3115 // namespaces of its associated classes. 3116 case Type::Record: { 3117 CXXRecordDecl *Class = 3118 cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl()); 3119 addAssociatedClassesAndNamespaces(Result, Class); 3120 break; 3121 } 3122 3123 // -- If T is an enumeration type, its associated namespace 3124 // is the innermost enclosing namespace of its declaration. 3125 // If it is a class member, its associated class is the 3126 // member’s class; else it has no associated class. 3127 case Type::Enum: { 3128 EnumDecl *Enum = cast<EnumType>(T)->getDecl(); 3129 3130 DeclContext *Ctx = Enum->getDeclContext(); 3131 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 3132 Result.Classes.insert(EnclosingClass); 3133 3134 // Add the associated namespace for this enumeration. 3135 CollectEnclosingNamespace(Result.Namespaces, Ctx); 3136 3137 break; 3138 } 3139 3140 // -- If T is a function type, its associated namespaces and 3141 // classes are those associated with the function parameter 3142 // types and those associated with the return type. 3143 case Type::FunctionProto: { 3144 const FunctionProtoType *Proto = cast<FunctionProtoType>(T); 3145 for (const auto &Arg : Proto->param_types()) 3146 Queue.push_back(Arg.getTypePtr()); 3147 // fallthrough 3148 LLVM_FALLTHROUGH; 3149 } 3150 case Type::FunctionNoProto: { 3151 const FunctionType *FnType = cast<FunctionType>(T); 3152 T = FnType->getReturnType().getTypePtr(); 3153 continue; 3154 } 3155 3156 // -- If T is a pointer to a member function of a class X, its 3157 // associated namespaces and classes are those associated 3158 // with the function parameter types and return type, 3159 // together with those associated with X. 3160 // 3161 // -- If T is a pointer to a data member of class X, its 3162 // associated namespaces and classes are those associated 3163 // with the member type together with those associated with 3164 // X. 3165 case Type::MemberPointer: { 3166 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T); 3167 3168 // Queue up the class type into which this points. 3169 Queue.push_back(MemberPtr->getClass()); 3170 3171 // And directly continue with the pointee type. 3172 T = MemberPtr->getPointeeType().getTypePtr(); 3173 continue; 3174 } 3175 3176 // As an extension, treat this like a normal pointer. 3177 case Type::BlockPointer: 3178 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr(); 3179 continue; 3180 3181 // References aren't covered by the standard, but that's such an 3182 // obvious defect that we cover them anyway. 3183 case Type::LValueReference: 3184 case Type::RValueReference: 3185 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr(); 3186 continue; 3187 3188 // These are fundamental types. 3189 case Type::Vector: 3190 case Type::ExtVector: 3191 case Type::ConstantMatrix: 3192 case Type::Complex: 3193 case Type::BitInt: 3194 break; 3195 3196 // Non-deduced auto types only get here for error cases. 3197 case Type::Auto: 3198 case Type::DeducedTemplateSpecialization: 3199 break; 3200 3201 // If T is an Objective-C object or interface type, or a pointer to an 3202 // object or interface type, the associated namespace is the global 3203 // namespace. 3204 case Type::ObjCObject: 3205 case Type::ObjCInterface: 3206 case Type::ObjCObjectPointer: 3207 Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl()); 3208 break; 3209 3210 // Atomic types are just wrappers; use the associations of the 3211 // contained type. 3212 case Type::Atomic: 3213 T = cast<AtomicType>(T)->getValueType().getTypePtr(); 3214 continue; 3215 case Type::Pipe: 3216 T = cast<PipeType>(T)->getElementType().getTypePtr(); 3217 continue; 3218 } 3219 3220 if (Queue.empty()) 3221 break; 3222 T = Queue.pop_back_val(); 3223 } 3224 } 3225 3226 /// Find the associated classes and namespaces for 3227 /// argument-dependent lookup for a call with the given set of 3228 /// arguments. 3229 /// 3230 /// This routine computes the sets of associated classes and associated 3231 /// namespaces searched by argument-dependent lookup 3232 /// (C++ [basic.lookup.argdep]) for a given set of arguments. 3233 void Sema::FindAssociatedClassesAndNamespaces( 3234 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args, 3235 AssociatedNamespaceSet &AssociatedNamespaces, 3236 AssociatedClassSet &AssociatedClasses) { 3237 AssociatedNamespaces.clear(); 3238 AssociatedClasses.clear(); 3239 3240 AssociatedLookup Result(*this, InstantiationLoc, 3241 AssociatedNamespaces, AssociatedClasses); 3242 3243 // C++ [basic.lookup.koenig]p2: 3244 // For each argument type T in the function call, there is a set 3245 // of zero or more associated namespaces and a set of zero or more 3246 // associated classes to be considered. The sets of namespaces and 3247 // classes is determined entirely by the types of the function 3248 // arguments (and the namespace of any template template 3249 // argument). 3250 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) { 3251 Expr *Arg = Args[ArgIdx]; 3252 3253 if (Arg->getType() != Context.OverloadTy) { 3254 addAssociatedClassesAndNamespaces(Result, Arg->getType()); 3255 continue; 3256 } 3257 3258 // [...] In addition, if the argument is the name or address of a 3259 // set of overloaded functions and/or function templates, its 3260 // associated classes and namespaces are the union of those 3261 // associated with each of the members of the set: the namespace 3262 // in which the function or function template is defined and the 3263 // classes and namespaces associated with its (non-dependent) 3264 // parameter types and return type. 3265 OverloadExpr *OE = OverloadExpr::find(Arg).Expression; 3266 3267 for (const NamedDecl *D : OE->decls()) { 3268 // Look through any using declarations to find the underlying function. 3269 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction(); 3270 3271 // Add the classes and namespaces associated with the parameter 3272 // types and return type of this function. 3273 addAssociatedClassesAndNamespaces(Result, FDecl->getType()); 3274 } 3275 } 3276 } 3277 3278 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name, 3279 SourceLocation Loc, 3280 LookupNameKind NameKind, 3281 RedeclarationKind Redecl) { 3282 LookupResult R(*this, Name, Loc, NameKind, Redecl); 3283 LookupName(R, S); 3284 return R.getAsSingle<NamedDecl>(); 3285 } 3286 3287 /// Find the protocol with the given name, if any. 3288 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II, 3289 SourceLocation IdLoc, 3290 RedeclarationKind Redecl) { 3291 Decl *D = LookupSingleName(TUScope, II, IdLoc, 3292 LookupObjCProtocolName, Redecl); 3293 return cast_or_null<ObjCProtocolDecl>(D); 3294 } 3295 3296 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, 3297 UnresolvedSetImpl &Functions) { 3298 // C++ [over.match.oper]p3: 3299 // -- The set of non-member candidates is the result of the 3300 // unqualified lookup of operator@ in the context of the 3301 // expression according to the usual rules for name lookup in 3302 // unqualified function calls (3.4.2) except that all member 3303 // functions are ignored. 3304 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3305 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName); 3306 LookupName(Operators, S); 3307 3308 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); 3309 Functions.append(Operators.begin(), Operators.end()); 3310 } 3311 3312 Sema::SpecialMemberOverloadResult Sema::LookupSpecialMember(CXXRecordDecl *RD, 3313 CXXSpecialMember SM, 3314 bool ConstArg, 3315 bool VolatileArg, 3316 bool RValueThis, 3317 bool ConstThis, 3318 bool VolatileThis) { 3319 assert(CanDeclareSpecialMemberFunction(RD) && 3320 "doing special member lookup into record that isn't fully complete"); 3321 RD = RD->getDefinition(); 3322 if (RValueThis || ConstThis || VolatileThis) 3323 assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) && 3324 "constructors and destructors always have unqualified lvalue this"); 3325 if (ConstArg || VolatileArg) 3326 assert((SM != CXXDefaultConstructor && SM != CXXDestructor) && 3327 "parameter-less special members can't have qualified arguments"); 3328 3329 // FIXME: Get the caller to pass in a location for the lookup. 3330 SourceLocation LookupLoc = RD->getLocation(); 3331 3332 llvm::FoldingSetNodeID ID; 3333 ID.AddPointer(RD); 3334 ID.AddInteger(SM); 3335 ID.AddInteger(ConstArg); 3336 ID.AddInteger(VolatileArg); 3337 ID.AddInteger(RValueThis); 3338 ID.AddInteger(ConstThis); 3339 ID.AddInteger(VolatileThis); 3340 3341 void *InsertPoint; 3342 SpecialMemberOverloadResultEntry *Result = 3343 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint); 3344 3345 // This was already cached 3346 if (Result) 3347 return *Result; 3348 3349 Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>(); 3350 Result = new (Result) SpecialMemberOverloadResultEntry(ID); 3351 SpecialMemberCache.InsertNode(Result, InsertPoint); 3352 3353 if (SM == CXXDestructor) { 3354 if (RD->needsImplicitDestructor()) { 3355 runWithSufficientStackSpace(RD->getLocation(), [&] { 3356 DeclareImplicitDestructor(RD); 3357 }); 3358 } 3359 CXXDestructorDecl *DD = RD->getDestructor(); 3360 Result->setMethod(DD); 3361 Result->setKind(DD && !DD->isDeleted() 3362 ? SpecialMemberOverloadResult::Success 3363 : SpecialMemberOverloadResult::NoMemberOrDeleted); 3364 return *Result; 3365 } 3366 3367 // Prepare for overload resolution. Here we construct a synthetic argument 3368 // if necessary and make sure that implicit functions are declared. 3369 CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD)); 3370 DeclarationName Name; 3371 Expr *Arg = nullptr; 3372 unsigned NumArgs; 3373 3374 QualType ArgType = CanTy; 3375 ExprValueKind VK = VK_LValue; 3376 3377 if (SM == CXXDefaultConstructor) { 3378 Name = Context.DeclarationNames.getCXXConstructorName(CanTy); 3379 NumArgs = 0; 3380 if (RD->needsImplicitDefaultConstructor()) { 3381 runWithSufficientStackSpace(RD->getLocation(), [&] { 3382 DeclareImplicitDefaultConstructor(RD); 3383 }); 3384 } 3385 } else { 3386 if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) { 3387 Name = Context.DeclarationNames.getCXXConstructorName(CanTy); 3388 if (RD->needsImplicitCopyConstructor()) { 3389 runWithSufficientStackSpace(RD->getLocation(), [&] { 3390 DeclareImplicitCopyConstructor(RD); 3391 }); 3392 } 3393 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor()) { 3394 runWithSufficientStackSpace(RD->getLocation(), [&] { 3395 DeclareImplicitMoveConstructor(RD); 3396 }); 3397 } 3398 } else { 3399 Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal); 3400 if (RD->needsImplicitCopyAssignment()) { 3401 runWithSufficientStackSpace(RD->getLocation(), [&] { 3402 DeclareImplicitCopyAssignment(RD); 3403 }); 3404 } 3405 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment()) { 3406 runWithSufficientStackSpace(RD->getLocation(), [&] { 3407 DeclareImplicitMoveAssignment(RD); 3408 }); 3409 } 3410 } 3411 3412 if (ConstArg) 3413 ArgType.addConst(); 3414 if (VolatileArg) 3415 ArgType.addVolatile(); 3416 3417 // This isn't /really/ specified by the standard, but it's implied 3418 // we should be working from a PRValue in the case of move to ensure 3419 // that we prefer to bind to rvalue references, and an LValue in the 3420 // case of copy to ensure we don't bind to rvalue references. 3421 // Possibly an XValue is actually correct in the case of move, but 3422 // there is no semantic difference for class types in this restricted 3423 // case. 3424 if (SM == CXXCopyConstructor || SM == CXXCopyAssignment) 3425 VK = VK_LValue; 3426 else 3427 VK = VK_PRValue; 3428 } 3429 3430 OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK); 3431 3432 if (SM != CXXDefaultConstructor) { 3433 NumArgs = 1; 3434 Arg = &FakeArg; 3435 } 3436 3437 // Create the object argument 3438 QualType ThisTy = CanTy; 3439 if (ConstThis) 3440 ThisTy.addConst(); 3441 if (VolatileThis) 3442 ThisTy.addVolatile(); 3443 Expr::Classification Classification = 3444 OpaqueValueExpr(LookupLoc, ThisTy, RValueThis ? VK_PRValue : VK_LValue) 3445 .Classify(Context); 3446 3447 // Now we perform lookup on the name we computed earlier and do overload 3448 // resolution. Lookup is only performed directly into the class since there 3449 // will always be a (possibly implicit) declaration to shadow any others. 3450 OverloadCandidateSet OCS(LookupLoc, OverloadCandidateSet::CSK_Normal); 3451 DeclContext::lookup_result R = RD->lookup(Name); 3452 3453 if (R.empty()) { 3454 // We might have no default constructor because we have a lambda's closure 3455 // type, rather than because there's some other declared constructor. 3456 // Every class has a copy/move constructor, copy/move assignment, and 3457 // destructor. 3458 assert(SM == CXXDefaultConstructor && 3459 "lookup for a constructor or assignment operator was empty"); 3460 Result->setMethod(nullptr); 3461 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 3462 return *Result; 3463 } 3464 3465 // Copy the candidates as our processing of them may load new declarations 3466 // from an external source and invalidate lookup_result. 3467 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end()); 3468 3469 for (NamedDecl *CandDecl : Candidates) { 3470 if (CandDecl->isInvalidDecl()) 3471 continue; 3472 3473 DeclAccessPair Cand = DeclAccessPair::make(CandDecl, AS_public); 3474 auto CtorInfo = getConstructorInfo(Cand); 3475 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl())) { 3476 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) 3477 AddMethodCandidate(M, Cand, RD, ThisTy, Classification, 3478 llvm::makeArrayRef(&Arg, NumArgs), OCS, true); 3479 else if (CtorInfo) 3480 AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl, 3481 llvm::makeArrayRef(&Arg, NumArgs), OCS, 3482 /*SuppressUserConversions*/ true); 3483 else 3484 AddOverloadCandidate(M, Cand, llvm::makeArrayRef(&Arg, NumArgs), OCS, 3485 /*SuppressUserConversions*/ true); 3486 } else if (FunctionTemplateDecl *Tmpl = 3487 dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) { 3488 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) 3489 AddMethodTemplateCandidate( 3490 Tmpl, Cand, RD, nullptr, ThisTy, Classification, 3491 llvm::makeArrayRef(&Arg, NumArgs), OCS, true); 3492 else if (CtorInfo) 3493 AddTemplateOverloadCandidate( 3494 CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr, 3495 llvm::makeArrayRef(&Arg, NumArgs), OCS, true); 3496 else 3497 AddTemplateOverloadCandidate( 3498 Tmpl, Cand, nullptr, llvm::makeArrayRef(&Arg, NumArgs), OCS, true); 3499 } else { 3500 assert(isa<UsingDecl>(Cand.getDecl()) && 3501 "illegal Kind of operator = Decl"); 3502 } 3503 } 3504 3505 OverloadCandidateSet::iterator Best; 3506 switch (OCS.BestViableFunction(*this, LookupLoc, Best)) { 3507 case OR_Success: 3508 Result->setMethod(cast<CXXMethodDecl>(Best->Function)); 3509 Result->setKind(SpecialMemberOverloadResult::Success); 3510 break; 3511 3512 case OR_Deleted: 3513 Result->setMethod(cast<CXXMethodDecl>(Best->Function)); 3514 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 3515 break; 3516 3517 case OR_Ambiguous: 3518 Result->setMethod(nullptr); 3519 Result->setKind(SpecialMemberOverloadResult::Ambiguous); 3520 break; 3521 3522 case OR_No_Viable_Function: 3523 Result->setMethod(nullptr); 3524 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); 3525 break; 3526 } 3527 3528 return *Result; 3529 } 3530 3531 /// Look up the default constructor for the given class. 3532 CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) { 3533 SpecialMemberOverloadResult Result = 3534 LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false, 3535 false, false); 3536 3537 return cast_or_null<CXXConstructorDecl>(Result.getMethod()); 3538 } 3539 3540 /// Look up the copying constructor for the given class. 3541 CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class, 3542 unsigned Quals) { 3543 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 3544 "non-const, non-volatile qualifiers for copy ctor arg"); 3545 SpecialMemberOverloadResult Result = 3546 LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const, 3547 Quals & Qualifiers::Volatile, false, false, false); 3548 3549 return cast_or_null<CXXConstructorDecl>(Result.getMethod()); 3550 } 3551 3552 /// Look up the moving constructor for the given class. 3553 CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class, 3554 unsigned Quals) { 3555 SpecialMemberOverloadResult Result = 3556 LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const, 3557 Quals & Qualifiers::Volatile, false, false, false); 3558 3559 return cast_or_null<CXXConstructorDecl>(Result.getMethod()); 3560 } 3561 3562 /// Look up the constructors for the given class. 3563 DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) { 3564 // If the implicit constructors have not yet been declared, do so now. 3565 if (CanDeclareSpecialMemberFunction(Class)) { 3566 runWithSufficientStackSpace(Class->getLocation(), [&] { 3567 if (Class->needsImplicitDefaultConstructor()) 3568 DeclareImplicitDefaultConstructor(Class); 3569 if (Class->needsImplicitCopyConstructor()) 3570 DeclareImplicitCopyConstructor(Class); 3571 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor()) 3572 DeclareImplicitMoveConstructor(Class); 3573 }); 3574 } 3575 3576 CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class)); 3577 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T); 3578 return Class->lookup(Name); 3579 } 3580 3581 /// Look up the copying assignment operator for the given class. 3582 CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class, 3583 unsigned Quals, bool RValueThis, 3584 unsigned ThisQuals) { 3585 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 3586 "non-const, non-volatile qualifiers for copy assignment arg"); 3587 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 3588 "non-const, non-volatile qualifiers for copy assignment this"); 3589 SpecialMemberOverloadResult Result = 3590 LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const, 3591 Quals & Qualifiers::Volatile, RValueThis, 3592 ThisQuals & Qualifiers::Const, 3593 ThisQuals & Qualifiers::Volatile); 3594 3595 return Result.getMethod(); 3596 } 3597 3598 /// Look up the moving assignment operator for the given class. 3599 CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class, 3600 unsigned Quals, 3601 bool RValueThis, 3602 unsigned ThisQuals) { 3603 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && 3604 "non-const, non-volatile qualifiers for copy assignment this"); 3605 SpecialMemberOverloadResult Result = 3606 LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const, 3607 Quals & Qualifiers::Volatile, RValueThis, 3608 ThisQuals & Qualifiers::Const, 3609 ThisQuals & Qualifiers::Volatile); 3610 3611 return Result.getMethod(); 3612 } 3613 3614 /// Look for the destructor of the given class. 3615 /// 3616 /// During semantic analysis, this routine should be used in lieu of 3617 /// CXXRecordDecl::getDestructor(). 3618 /// 3619 /// \returns The destructor for this class. 3620 CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) { 3621 return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor, 3622 false, false, false, 3623 false, false).getMethod()); 3624 } 3625 3626 /// LookupLiteralOperator - Determine which literal operator should be used for 3627 /// a user-defined literal, per C++11 [lex.ext]. 3628 /// 3629 /// Normal overload resolution is not used to select which literal operator to 3630 /// call for a user-defined literal. Look up the provided literal operator name, 3631 /// and filter the results to the appropriate set for the given argument types. 3632 Sema::LiteralOperatorLookupResult 3633 Sema::LookupLiteralOperator(Scope *S, LookupResult &R, 3634 ArrayRef<QualType> ArgTys, bool AllowRaw, 3635 bool AllowTemplate, bool AllowStringTemplatePack, 3636 bool DiagnoseMissing, StringLiteral *StringLit) { 3637 LookupName(R, S); 3638 assert(R.getResultKind() != LookupResult::Ambiguous && 3639 "literal operator lookup can't be ambiguous"); 3640 3641 // Filter the lookup results appropriately. 3642 LookupResult::Filter F = R.makeFilter(); 3643 3644 bool AllowCooked = true; 3645 bool FoundRaw = false; 3646 bool FoundTemplate = false; 3647 bool FoundStringTemplatePack = false; 3648 bool FoundCooked = false; 3649 3650 while (F.hasNext()) { 3651 Decl *D = F.next(); 3652 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D)) 3653 D = USD->getTargetDecl(); 3654 3655 // If the declaration we found is invalid, skip it. 3656 if (D->isInvalidDecl()) { 3657 F.erase(); 3658 continue; 3659 } 3660 3661 bool IsRaw = false; 3662 bool IsTemplate = false; 3663 bool IsStringTemplatePack = false; 3664 bool IsCooked = false; 3665 3666 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3667 if (FD->getNumParams() == 1 && 3668 FD->getParamDecl(0)->getType()->getAs<PointerType>()) 3669 IsRaw = true; 3670 else if (FD->getNumParams() == ArgTys.size()) { 3671 IsCooked = true; 3672 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) { 3673 QualType ParamTy = FD->getParamDecl(ArgIdx)->getType(); 3674 if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) { 3675 IsCooked = false; 3676 break; 3677 } 3678 } 3679 } 3680 } 3681 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) { 3682 TemplateParameterList *Params = FD->getTemplateParameters(); 3683 if (Params->size() == 1) { 3684 IsTemplate = true; 3685 if (!Params->getParam(0)->isTemplateParameterPack() && !StringLit) { 3686 // Implied but not stated: user-defined integer and floating literals 3687 // only ever use numeric literal operator templates, not templates 3688 // taking a parameter of class type. 3689 F.erase(); 3690 continue; 3691 } 3692 3693 // A string literal template is only considered if the string literal 3694 // is a well-formed template argument for the template parameter. 3695 if (StringLit) { 3696 SFINAETrap Trap(*this); 3697 SmallVector<TemplateArgument, 1> Checked; 3698 TemplateArgumentLoc Arg(TemplateArgument(StringLit), StringLit); 3699 if (CheckTemplateArgument(Params->getParam(0), Arg, FD, 3700 R.getNameLoc(), R.getNameLoc(), 0, 3701 Checked) || 3702 Trap.hasErrorOccurred()) 3703 IsTemplate = false; 3704 } 3705 } else { 3706 IsStringTemplatePack = true; 3707 } 3708 } 3709 3710 if (AllowTemplate && StringLit && IsTemplate) { 3711 FoundTemplate = true; 3712 AllowRaw = false; 3713 AllowCooked = false; 3714 AllowStringTemplatePack = false; 3715 if (FoundRaw || FoundCooked || FoundStringTemplatePack) { 3716 F.restart(); 3717 FoundRaw = FoundCooked = FoundStringTemplatePack = false; 3718 } 3719 } else if (AllowCooked && IsCooked) { 3720 FoundCooked = true; 3721 AllowRaw = false; 3722 AllowTemplate = StringLit; 3723 AllowStringTemplatePack = false; 3724 if (FoundRaw || FoundTemplate || FoundStringTemplatePack) { 3725 // Go through again and remove the raw and template decls we've 3726 // already found. 3727 F.restart(); 3728 FoundRaw = FoundTemplate = FoundStringTemplatePack = false; 3729 } 3730 } else if (AllowRaw && IsRaw) { 3731 FoundRaw = true; 3732 } else if (AllowTemplate && IsTemplate) { 3733 FoundTemplate = true; 3734 } else if (AllowStringTemplatePack && IsStringTemplatePack) { 3735 FoundStringTemplatePack = true; 3736 } else { 3737 F.erase(); 3738 } 3739 } 3740 3741 F.done(); 3742 3743 // Per C++20 [lex.ext]p5, we prefer the template form over the non-template 3744 // form for string literal operator templates. 3745 if (StringLit && FoundTemplate) 3746 return LOLR_Template; 3747 3748 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching 3749 // parameter type, that is used in preference to a raw literal operator 3750 // or literal operator template. 3751 if (FoundCooked) 3752 return LOLR_Cooked; 3753 3754 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal 3755 // operator template, but not both. 3756 if (FoundRaw && FoundTemplate) { 3757 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName(); 3758 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 3759 NoteOverloadCandidate(*I, (*I)->getUnderlyingDecl()->getAsFunction()); 3760 return LOLR_Error; 3761 } 3762 3763 if (FoundRaw) 3764 return LOLR_Raw; 3765 3766 if (FoundTemplate) 3767 return LOLR_Template; 3768 3769 if (FoundStringTemplatePack) 3770 return LOLR_StringTemplatePack; 3771 3772 // Didn't find anything we could use. 3773 if (DiagnoseMissing) { 3774 Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator) 3775 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0] 3776 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw 3777 << (AllowTemplate || AllowStringTemplatePack); 3778 return LOLR_Error; 3779 } 3780 3781 return LOLR_ErrorNoDiagnostic; 3782 } 3783 3784 void ADLResult::insert(NamedDecl *New) { 3785 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())]; 3786 3787 // If we haven't yet seen a decl for this key, or the last decl 3788 // was exactly this one, we're done. 3789 if (Old == nullptr || Old == New) { 3790 Old = New; 3791 return; 3792 } 3793 3794 // Otherwise, decide which is a more recent redeclaration. 3795 FunctionDecl *OldFD = Old->getAsFunction(); 3796 FunctionDecl *NewFD = New->getAsFunction(); 3797 3798 FunctionDecl *Cursor = NewFD; 3799 while (true) { 3800 Cursor = Cursor->getPreviousDecl(); 3801 3802 // If we got to the end without finding OldFD, OldFD is the newer 3803 // declaration; leave things as they are. 3804 if (!Cursor) return; 3805 3806 // If we do find OldFD, then NewFD is newer. 3807 if (Cursor == OldFD) break; 3808 3809 // Otherwise, keep looking. 3810 } 3811 3812 Old = New; 3813 } 3814 3815 void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc, 3816 ArrayRef<Expr *> Args, ADLResult &Result) { 3817 // Find all of the associated namespaces and classes based on the 3818 // arguments we have. 3819 AssociatedNamespaceSet AssociatedNamespaces; 3820 AssociatedClassSet AssociatedClasses; 3821 FindAssociatedClassesAndNamespaces(Loc, Args, 3822 AssociatedNamespaces, 3823 AssociatedClasses); 3824 3825 // C++ [basic.lookup.argdep]p3: 3826 // Let X be the lookup set produced by unqualified lookup (3.4.1) 3827 // and let Y be the lookup set produced by argument dependent 3828 // lookup (defined as follows). If X contains [...] then Y is 3829 // empty. Otherwise Y is the set of declarations found in the 3830 // namespaces associated with the argument types as described 3831 // below. The set of declarations found by the lookup of the name 3832 // is the union of X and Y. 3833 // 3834 // Here, we compute Y and add its members to the overloaded 3835 // candidate set. 3836 for (auto *NS : AssociatedNamespaces) { 3837 // When considering an associated namespace, the lookup is the 3838 // same as the lookup performed when the associated namespace is 3839 // used as a qualifier (3.4.3.2) except that: 3840 // 3841 // -- Any using-directives in the associated namespace are 3842 // ignored. 3843 // 3844 // -- Any namespace-scope friend functions declared in 3845 // associated classes are visible within their respective 3846 // namespaces even if they are not visible during an ordinary 3847 // lookup (11.4). 3848 // 3849 // C++20 [basic.lookup.argdep] p4.3 3850 // -- are exported, are attached to a named module M, do not appear 3851 // in the translation unit containing the point of the lookup, and 3852 // have the same innermost enclosing non-inline namespace scope as 3853 // a declaration of an associated entity attached to M. 3854 DeclContext::lookup_result R = NS->lookup(Name); 3855 for (auto *D : R) { 3856 auto *Underlying = D; 3857 if (auto *USD = dyn_cast<UsingShadowDecl>(D)) 3858 Underlying = USD->getTargetDecl(); 3859 3860 if (!isa<FunctionDecl>(Underlying) && 3861 !isa<FunctionTemplateDecl>(Underlying)) 3862 continue; 3863 3864 // The declaration is visible to argument-dependent lookup if either 3865 // it's ordinarily visible or declared as a friend in an associated 3866 // class. 3867 bool Visible = false; 3868 for (D = D->getMostRecentDecl(); D; 3869 D = cast_or_null<NamedDecl>(D->getPreviousDecl())) { 3870 if (D->getIdentifierNamespace() & Decl::IDNS_Ordinary) { 3871 if (isVisible(D)) { 3872 Visible = true; 3873 break; 3874 } else if (getLangOpts().CPlusPlusModules && 3875 D->isInExportDeclContext()) { 3876 // C++20 [basic.lookup.argdep] p4.3 .. are exported ... 3877 Module *FM = D->getOwningModule(); 3878 // exports are only valid in module purview and outside of any 3879 // PMF (although a PMF should not even be present in a module 3880 // with an import). 3881 assert(FM && FM->isModulePurview() && !FM->isPrivateModule() && 3882 "bad export context"); 3883 // .. are attached to a named module M, do not appear in the 3884 // translation unit containing the point of the lookup.. 3885 if (!isModuleUnitOfCurrentTU(FM) && 3886 llvm::any_of(AssociatedClasses, [&](auto *E) { 3887 // ... and have the same innermost enclosing non-inline 3888 // namespace scope as a declaration of an associated entity 3889 // attached to M 3890 if (!E->hasOwningModule() || 3891 E->getOwningModule()->getTopLevelModuleName() != 3892 FM->getTopLevelModuleName()) 3893 return false; 3894 // TODO: maybe this could be cached when generating the 3895 // associated namespaces / entities. 3896 DeclContext *Ctx = E->getDeclContext(); 3897 while (!Ctx->isFileContext() || Ctx->isInlineNamespace()) 3898 Ctx = Ctx->getParent(); 3899 return Ctx == NS; 3900 })) { 3901 Visible = true; 3902 break; 3903 } 3904 } 3905 } else if (D->getFriendObjectKind()) { 3906 auto *RD = cast<CXXRecordDecl>(D->getLexicalDeclContext()); 3907 // [basic.lookup.argdep]p4: 3908 // Argument-dependent lookup finds all declarations of functions and 3909 // function templates that 3910 // - ... 3911 // - are declared as a friend ([class.friend]) of any class with a 3912 // reachable definition in the set of associated entities, 3913 // 3914 // FIXME: If there's a merged definition of D that is reachable, then 3915 // the friend declaration should be considered. 3916 if (AssociatedClasses.count(RD) && isReachable(D)) { 3917 Visible = true; 3918 break; 3919 } 3920 } 3921 } 3922 3923 // FIXME: Preserve D as the FoundDecl. 3924 if (Visible) 3925 Result.insert(Underlying); 3926 } 3927 } 3928 } 3929 3930 //---------------------------------------------------------------------------- 3931 // Search for all visible declarations. 3932 //---------------------------------------------------------------------------- 3933 VisibleDeclConsumer::~VisibleDeclConsumer() { } 3934 3935 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; } 3936 3937 namespace { 3938 3939 class ShadowContextRAII; 3940 3941 class VisibleDeclsRecord { 3942 public: 3943 /// An entry in the shadow map, which is optimized to store a 3944 /// single declaration (the common case) but can also store a list 3945 /// of declarations. 3946 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry; 3947 3948 private: 3949 /// A mapping from declaration names to the declarations that have 3950 /// this name within a particular scope. 3951 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap; 3952 3953 /// A list of shadow maps, which is used to model name hiding. 3954 std::list<ShadowMap> ShadowMaps; 3955 3956 /// The declaration contexts we have already visited. 3957 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts; 3958 3959 friend class ShadowContextRAII; 3960 3961 public: 3962 /// Determine whether we have already visited this context 3963 /// (and, if not, note that we are going to visit that context now). 3964 bool visitedContext(DeclContext *Ctx) { 3965 return !VisitedContexts.insert(Ctx).second; 3966 } 3967 3968 bool alreadyVisitedContext(DeclContext *Ctx) { 3969 return VisitedContexts.count(Ctx); 3970 } 3971 3972 /// Determine whether the given declaration is hidden in the 3973 /// current scope. 3974 /// 3975 /// \returns the declaration that hides the given declaration, or 3976 /// NULL if no such declaration exists. 3977 NamedDecl *checkHidden(NamedDecl *ND); 3978 3979 /// Add a declaration to the current shadow map. 3980 void add(NamedDecl *ND) { 3981 ShadowMaps.back()[ND->getDeclName()].push_back(ND); 3982 } 3983 }; 3984 3985 /// RAII object that records when we've entered a shadow context. 3986 class ShadowContextRAII { 3987 VisibleDeclsRecord &Visible; 3988 3989 typedef VisibleDeclsRecord::ShadowMap ShadowMap; 3990 3991 public: 3992 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) { 3993 Visible.ShadowMaps.emplace_back(); 3994 } 3995 3996 ~ShadowContextRAII() { 3997 Visible.ShadowMaps.pop_back(); 3998 } 3999 }; 4000 4001 } // end anonymous namespace 4002 4003 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) { 4004 unsigned IDNS = ND->getIdentifierNamespace(); 4005 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin(); 4006 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend(); 4007 SM != SMEnd; ++SM) { 4008 ShadowMap::iterator Pos = SM->find(ND->getDeclName()); 4009 if (Pos == SM->end()) 4010 continue; 4011 4012 for (auto *D : Pos->second) { 4013 // A tag declaration does not hide a non-tag declaration. 4014 if (D->hasTagIdentifierNamespace() && 4015 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary | 4016 Decl::IDNS_ObjCProtocol))) 4017 continue; 4018 4019 // Protocols are in distinct namespaces from everything else. 4020 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol) 4021 || (IDNS & Decl::IDNS_ObjCProtocol)) && 4022 D->getIdentifierNamespace() != IDNS) 4023 continue; 4024 4025 // Functions and function templates in the same scope overload 4026 // rather than hide. FIXME: Look for hiding based on function 4027 // signatures! 4028 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() && 4029 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() && 4030 SM == ShadowMaps.rbegin()) 4031 continue; 4032 4033 // A shadow declaration that's created by a resolved using declaration 4034 // is not hidden by the same using declaration. 4035 if (isa<UsingShadowDecl>(ND) && isa<UsingDecl>(D) && 4036 cast<UsingShadowDecl>(ND)->getIntroducer() == D) 4037 continue; 4038 4039 // We've found a declaration that hides this one. 4040 return D; 4041 } 4042 } 4043 4044 return nullptr; 4045 } 4046 4047 namespace { 4048 class LookupVisibleHelper { 4049 public: 4050 LookupVisibleHelper(VisibleDeclConsumer &Consumer, bool IncludeDependentBases, 4051 bool LoadExternal) 4052 : Consumer(Consumer), IncludeDependentBases(IncludeDependentBases), 4053 LoadExternal(LoadExternal) {} 4054 4055 void lookupVisibleDecls(Sema &SemaRef, Scope *S, Sema::LookupNameKind Kind, 4056 bool IncludeGlobalScope) { 4057 // Determine the set of using directives available during 4058 // unqualified name lookup. 4059 Scope *Initial = S; 4060 UnqualUsingDirectiveSet UDirs(SemaRef); 4061 if (SemaRef.getLangOpts().CPlusPlus) { 4062 // Find the first namespace or translation-unit scope. 4063 while (S && !isNamespaceOrTranslationUnitScope(S)) 4064 S = S->getParent(); 4065 4066 UDirs.visitScopeChain(Initial, S); 4067 } 4068 UDirs.done(); 4069 4070 // Look for visible declarations. 4071 LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind); 4072 Result.setAllowHidden(Consumer.includeHiddenDecls()); 4073 if (!IncludeGlobalScope) 4074 Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl()); 4075 ShadowContextRAII Shadow(Visited); 4076 lookupInScope(Initial, Result, UDirs); 4077 } 4078 4079 void lookupVisibleDecls(Sema &SemaRef, DeclContext *Ctx, 4080 Sema::LookupNameKind Kind, bool IncludeGlobalScope) { 4081 LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind); 4082 Result.setAllowHidden(Consumer.includeHiddenDecls()); 4083 if (!IncludeGlobalScope) 4084 Visited.visitedContext(SemaRef.getASTContext().getTranslationUnitDecl()); 4085 4086 ShadowContextRAII Shadow(Visited); 4087 lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/true, 4088 /*InBaseClass=*/false); 4089 } 4090 4091 private: 4092 void lookupInDeclContext(DeclContext *Ctx, LookupResult &Result, 4093 bool QualifiedNameLookup, bool InBaseClass) { 4094 if (!Ctx) 4095 return; 4096 4097 // Make sure we don't visit the same context twice. 4098 if (Visited.visitedContext(Ctx->getPrimaryContext())) 4099 return; 4100 4101 Consumer.EnteredContext(Ctx); 4102 4103 // Outside C++, lookup results for the TU live on identifiers. 4104 if (isa<TranslationUnitDecl>(Ctx) && 4105 !Result.getSema().getLangOpts().CPlusPlus) { 4106 auto &S = Result.getSema(); 4107 auto &Idents = S.Context.Idents; 4108 4109 // Ensure all external identifiers are in the identifier table. 4110 if (LoadExternal) 4111 if (IdentifierInfoLookup *External = 4112 Idents.getExternalIdentifierLookup()) { 4113 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers()); 4114 for (StringRef Name = Iter->Next(); !Name.empty(); 4115 Name = Iter->Next()) 4116 Idents.get(Name); 4117 } 4118 4119 // Walk all lookup results in the TU for each identifier. 4120 for (const auto &Ident : Idents) { 4121 for (auto I = S.IdResolver.begin(Ident.getValue()), 4122 E = S.IdResolver.end(); 4123 I != E; ++I) { 4124 if (S.IdResolver.isDeclInScope(*I, Ctx)) { 4125 if (NamedDecl *ND = Result.getAcceptableDecl(*I)) { 4126 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass); 4127 Visited.add(ND); 4128 } 4129 } 4130 } 4131 } 4132 4133 return; 4134 } 4135 4136 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx)) 4137 Result.getSema().ForceDeclarationOfImplicitMembers(Class); 4138 4139 llvm::SmallVector<NamedDecl *, 4> DeclsToVisit; 4140 // We sometimes skip loading namespace-level results (they tend to be huge). 4141 bool Load = LoadExternal || 4142 !(isa<TranslationUnitDecl>(Ctx) || isa<NamespaceDecl>(Ctx)); 4143 // Enumerate all of the results in this context. 4144 for (DeclContextLookupResult R : 4145 Load ? Ctx->lookups() 4146 : Ctx->noload_lookups(/*PreserveInternalState=*/false)) { 4147 for (auto *D : R) { 4148 if (auto *ND = Result.getAcceptableDecl(D)) { 4149 // Rather than visit immediately, we put ND into a vector and visit 4150 // all decls, in order, outside of this loop. The reason is that 4151 // Consumer.FoundDecl() may invalidate the iterators used in the two 4152 // loops above. 4153 DeclsToVisit.push_back(ND); 4154 } 4155 } 4156 } 4157 4158 for (auto *ND : DeclsToVisit) { 4159 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass); 4160 Visited.add(ND); 4161 } 4162 DeclsToVisit.clear(); 4163 4164 // Traverse using directives for qualified name lookup. 4165 if (QualifiedNameLookup) { 4166 ShadowContextRAII Shadow(Visited); 4167 for (auto I : Ctx->using_directives()) { 4168 if (!Result.getSema().isVisible(I)) 4169 continue; 4170 lookupInDeclContext(I->getNominatedNamespace(), Result, 4171 QualifiedNameLookup, InBaseClass); 4172 } 4173 } 4174 4175 // Traverse the contexts of inherited C++ classes. 4176 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) { 4177 if (!Record->hasDefinition()) 4178 return; 4179 4180 for (const auto &B : Record->bases()) { 4181 QualType BaseType = B.getType(); 4182 4183 RecordDecl *RD; 4184 if (BaseType->isDependentType()) { 4185 if (!IncludeDependentBases) { 4186 // Don't look into dependent bases, because name lookup can't look 4187 // there anyway. 4188 continue; 4189 } 4190 const auto *TST = BaseType->getAs<TemplateSpecializationType>(); 4191 if (!TST) 4192 continue; 4193 TemplateName TN = TST->getTemplateName(); 4194 const auto *TD = 4195 dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl()); 4196 if (!TD) 4197 continue; 4198 RD = TD->getTemplatedDecl(); 4199 } else { 4200 const auto *Record = BaseType->getAs<RecordType>(); 4201 if (!Record) 4202 continue; 4203 RD = Record->getDecl(); 4204 } 4205 4206 // FIXME: It would be nice to be able to determine whether referencing 4207 // a particular member would be ambiguous. For example, given 4208 // 4209 // struct A { int member; }; 4210 // struct B { int member; }; 4211 // struct C : A, B { }; 4212 // 4213 // void f(C *c) { c->### } 4214 // 4215 // accessing 'member' would result in an ambiguity. However, we 4216 // could be smart enough to qualify the member with the base 4217 // class, e.g., 4218 // 4219 // c->B::member 4220 // 4221 // or 4222 // 4223 // c->A::member 4224 4225 // Find results in this base class (and its bases). 4226 ShadowContextRAII Shadow(Visited); 4227 lookupInDeclContext(RD, Result, QualifiedNameLookup, 4228 /*InBaseClass=*/true); 4229 } 4230 } 4231 4232 // Traverse the contexts of Objective-C classes. 4233 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) { 4234 // Traverse categories. 4235 for (auto *Cat : IFace->visible_categories()) { 4236 ShadowContextRAII Shadow(Visited); 4237 lookupInDeclContext(Cat, Result, QualifiedNameLookup, 4238 /*InBaseClass=*/false); 4239 } 4240 4241 // Traverse protocols. 4242 for (auto *I : IFace->all_referenced_protocols()) { 4243 ShadowContextRAII Shadow(Visited); 4244 lookupInDeclContext(I, Result, QualifiedNameLookup, 4245 /*InBaseClass=*/false); 4246 } 4247 4248 // Traverse the superclass. 4249 if (IFace->getSuperClass()) { 4250 ShadowContextRAII Shadow(Visited); 4251 lookupInDeclContext(IFace->getSuperClass(), Result, QualifiedNameLookup, 4252 /*InBaseClass=*/true); 4253 } 4254 4255 // If there is an implementation, traverse it. We do this to find 4256 // synthesized ivars. 4257 if (IFace->getImplementation()) { 4258 ShadowContextRAII Shadow(Visited); 4259 lookupInDeclContext(IFace->getImplementation(), Result, 4260 QualifiedNameLookup, InBaseClass); 4261 } 4262 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) { 4263 for (auto *I : Protocol->protocols()) { 4264 ShadowContextRAII Shadow(Visited); 4265 lookupInDeclContext(I, Result, QualifiedNameLookup, 4266 /*InBaseClass=*/false); 4267 } 4268 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) { 4269 for (auto *I : Category->protocols()) { 4270 ShadowContextRAII Shadow(Visited); 4271 lookupInDeclContext(I, Result, QualifiedNameLookup, 4272 /*InBaseClass=*/false); 4273 } 4274 4275 // If there is an implementation, traverse it. 4276 if (Category->getImplementation()) { 4277 ShadowContextRAII Shadow(Visited); 4278 lookupInDeclContext(Category->getImplementation(), Result, 4279 QualifiedNameLookup, /*InBaseClass=*/true); 4280 } 4281 } 4282 } 4283 4284 void lookupInScope(Scope *S, LookupResult &Result, 4285 UnqualUsingDirectiveSet &UDirs) { 4286 // No clients run in this mode and it's not supported. Please add tests and 4287 // remove the assertion if you start relying on it. 4288 assert(!IncludeDependentBases && "Unsupported flag for lookupInScope"); 4289 4290 if (!S) 4291 return; 4292 4293 if (!S->getEntity() || 4294 (!S->getParent() && !Visited.alreadyVisitedContext(S->getEntity())) || 4295 (S->getEntity())->isFunctionOrMethod()) { 4296 FindLocalExternScope FindLocals(Result); 4297 // Walk through the declarations in this Scope. The consumer might add new 4298 // decls to the scope as part of deserialization, so make a copy first. 4299 SmallVector<Decl *, 8> ScopeDecls(S->decls().begin(), S->decls().end()); 4300 for (Decl *D : ScopeDecls) { 4301 if (NamedDecl *ND = dyn_cast<NamedDecl>(D)) 4302 if ((ND = Result.getAcceptableDecl(ND))) { 4303 Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false); 4304 Visited.add(ND); 4305 } 4306 } 4307 } 4308 4309 DeclContext *Entity = S->getLookupEntity(); 4310 if (Entity) { 4311 // Look into this scope's declaration context, along with any of its 4312 // parent lookup contexts (e.g., enclosing classes), up to the point 4313 // where we hit the context stored in the next outer scope. 4314 DeclContext *OuterCtx = findOuterContext(S); 4315 4316 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx); 4317 Ctx = Ctx->getLookupParent()) { 4318 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) { 4319 if (Method->isInstanceMethod()) { 4320 // For instance methods, look for ivars in the method's interface. 4321 LookupResult IvarResult(Result.getSema(), Result.getLookupName(), 4322 Result.getNameLoc(), 4323 Sema::LookupMemberName); 4324 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) { 4325 lookupInDeclContext(IFace, IvarResult, 4326 /*QualifiedNameLookup=*/false, 4327 /*InBaseClass=*/false); 4328 } 4329 } 4330 4331 // We've already performed all of the name lookup that we need 4332 // to for Objective-C methods; the next context will be the 4333 // outer scope. 4334 break; 4335 } 4336 4337 if (Ctx->isFunctionOrMethod()) 4338 continue; 4339 4340 lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/false, 4341 /*InBaseClass=*/false); 4342 } 4343 } else if (!S->getParent()) { 4344 // Look into the translation unit scope. We walk through the translation 4345 // unit's declaration context, because the Scope itself won't have all of 4346 // the declarations if we loaded a precompiled header. 4347 // FIXME: We would like the translation unit's Scope object to point to 4348 // the translation unit, so we don't need this special "if" branch. 4349 // However, doing so would force the normal C++ name-lookup code to look 4350 // into the translation unit decl when the IdentifierInfo chains would 4351 // suffice. Once we fix that problem (which is part of a more general 4352 // "don't look in DeclContexts unless we have to" optimization), we can 4353 // eliminate this. 4354 Entity = Result.getSema().Context.getTranslationUnitDecl(); 4355 lookupInDeclContext(Entity, Result, /*QualifiedNameLookup=*/false, 4356 /*InBaseClass=*/false); 4357 } 4358 4359 if (Entity) { 4360 // Lookup visible declarations in any namespaces found by using 4361 // directives. 4362 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity)) 4363 lookupInDeclContext( 4364 const_cast<DeclContext *>(UUE.getNominatedNamespace()), Result, 4365 /*QualifiedNameLookup=*/false, 4366 /*InBaseClass=*/false); 4367 } 4368 4369 // Lookup names in the parent scope. 4370 ShadowContextRAII Shadow(Visited); 4371 lookupInScope(S->getParent(), Result, UDirs); 4372 } 4373 4374 private: 4375 VisibleDeclsRecord Visited; 4376 VisibleDeclConsumer &Consumer; 4377 bool IncludeDependentBases; 4378 bool LoadExternal; 4379 }; 4380 } // namespace 4381 4382 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind, 4383 VisibleDeclConsumer &Consumer, 4384 bool IncludeGlobalScope, bool LoadExternal) { 4385 LookupVisibleHelper H(Consumer, /*IncludeDependentBases=*/false, 4386 LoadExternal); 4387 H.lookupVisibleDecls(*this, S, Kind, IncludeGlobalScope); 4388 } 4389 4390 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind, 4391 VisibleDeclConsumer &Consumer, 4392 bool IncludeGlobalScope, 4393 bool IncludeDependentBases, bool LoadExternal) { 4394 LookupVisibleHelper H(Consumer, IncludeDependentBases, LoadExternal); 4395 H.lookupVisibleDecls(*this, Ctx, Kind, IncludeGlobalScope); 4396 } 4397 4398 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name. 4399 /// If GnuLabelLoc is a valid source location, then this is a definition 4400 /// of an __label__ label name, otherwise it is a normal label definition 4401 /// or use. 4402 LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc, 4403 SourceLocation GnuLabelLoc) { 4404 // Do a lookup to see if we have a label with this name already. 4405 NamedDecl *Res = nullptr; 4406 4407 if (GnuLabelLoc.isValid()) { 4408 // Local label definitions always shadow existing labels. 4409 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc); 4410 Scope *S = CurScope; 4411 PushOnScopeChains(Res, S, true); 4412 return cast<LabelDecl>(Res); 4413 } 4414 4415 // Not a GNU local label. 4416 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration); 4417 // If we found a label, check to see if it is in the same context as us. 4418 // When in a Block, we don't want to reuse a label in an enclosing function. 4419 if (Res && Res->getDeclContext() != CurContext) 4420 Res = nullptr; 4421 if (!Res) { 4422 // If not forward referenced or defined already, create the backing decl. 4423 Res = LabelDecl::Create(Context, CurContext, Loc, II); 4424 Scope *S = CurScope->getFnParent(); 4425 assert(S && "Not in a function?"); 4426 PushOnScopeChains(Res, S, true); 4427 } 4428 return cast<LabelDecl>(Res); 4429 } 4430 4431 //===----------------------------------------------------------------------===// 4432 // Typo correction 4433 //===----------------------------------------------------------------------===// 4434 4435 static bool isCandidateViable(CorrectionCandidateCallback &CCC, 4436 TypoCorrection &Candidate) { 4437 Candidate.setCallbackDistance(CCC.RankCandidate(Candidate)); 4438 return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance; 4439 } 4440 4441 static void LookupPotentialTypoResult(Sema &SemaRef, 4442 LookupResult &Res, 4443 IdentifierInfo *Name, 4444 Scope *S, CXXScopeSpec *SS, 4445 DeclContext *MemberContext, 4446 bool EnteringContext, 4447 bool isObjCIvarLookup, 4448 bool FindHidden); 4449 4450 /// Check whether the declarations found for a typo correction are 4451 /// visible. Set the correction's RequiresImport flag to true if none of the 4452 /// declarations are visible, false otherwise. 4453 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) { 4454 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end(); 4455 4456 for (/**/; DI != DE; ++DI) 4457 if (!LookupResult::isVisible(SemaRef, *DI)) 4458 break; 4459 // No filtering needed if all decls are visible. 4460 if (DI == DE) { 4461 TC.setRequiresImport(false); 4462 return; 4463 } 4464 4465 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI); 4466 bool AnyVisibleDecls = !NewDecls.empty(); 4467 4468 for (/**/; DI != DE; ++DI) { 4469 if (LookupResult::isVisible(SemaRef, *DI)) { 4470 if (!AnyVisibleDecls) { 4471 // Found a visible decl, discard all hidden ones. 4472 AnyVisibleDecls = true; 4473 NewDecls.clear(); 4474 } 4475 NewDecls.push_back(*DI); 4476 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate()) 4477 NewDecls.push_back(*DI); 4478 } 4479 4480 if (NewDecls.empty()) 4481 TC = TypoCorrection(); 4482 else { 4483 TC.setCorrectionDecls(NewDecls); 4484 TC.setRequiresImport(!AnyVisibleDecls); 4485 } 4486 } 4487 4488 // Fill the supplied vector with the IdentifierInfo pointers for each piece of 4489 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::", 4490 // fill the vector with the IdentifierInfo pointers for "foo" and "bar"). 4491 static void getNestedNameSpecifierIdentifiers( 4492 NestedNameSpecifier *NNS, 4493 SmallVectorImpl<const IdentifierInfo*> &Identifiers) { 4494 if (NestedNameSpecifier *Prefix = NNS->getPrefix()) 4495 getNestedNameSpecifierIdentifiers(Prefix, Identifiers); 4496 else 4497 Identifiers.clear(); 4498 4499 const IdentifierInfo *II = nullptr; 4500 4501 switch (NNS->getKind()) { 4502 case NestedNameSpecifier::Identifier: 4503 II = NNS->getAsIdentifier(); 4504 break; 4505 4506 case NestedNameSpecifier::Namespace: 4507 if (NNS->getAsNamespace()->isAnonymousNamespace()) 4508 return; 4509 II = NNS->getAsNamespace()->getIdentifier(); 4510 break; 4511 4512 case NestedNameSpecifier::NamespaceAlias: 4513 II = NNS->getAsNamespaceAlias()->getIdentifier(); 4514 break; 4515 4516 case NestedNameSpecifier::TypeSpecWithTemplate: 4517 case NestedNameSpecifier::TypeSpec: 4518 II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier(); 4519 break; 4520 4521 case NestedNameSpecifier::Global: 4522 case NestedNameSpecifier::Super: 4523 return; 4524 } 4525 4526 if (II) 4527 Identifiers.push_back(II); 4528 } 4529 4530 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding, 4531 DeclContext *Ctx, bool InBaseClass) { 4532 // Don't consider hidden names for typo correction. 4533 if (Hiding) 4534 return; 4535 4536 // Only consider entities with identifiers for names, ignoring 4537 // special names (constructors, overloaded operators, selectors, 4538 // etc.). 4539 IdentifierInfo *Name = ND->getIdentifier(); 4540 if (!Name) 4541 return; 4542 4543 // Only consider visible declarations and declarations from modules with 4544 // names that exactly match. 4545 if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo) 4546 return; 4547 4548 FoundName(Name->getName()); 4549 } 4550 4551 void TypoCorrectionConsumer::FoundName(StringRef Name) { 4552 // Compute the edit distance between the typo and the name of this 4553 // entity, and add the identifier to the list of results. 4554 addName(Name, nullptr); 4555 } 4556 4557 void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) { 4558 // Compute the edit distance between the typo and this keyword, 4559 // and add the keyword to the list of results. 4560 addName(Keyword, nullptr, nullptr, true); 4561 } 4562 4563 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND, 4564 NestedNameSpecifier *NNS, bool isKeyword) { 4565 // Use a simple length-based heuristic to determine the minimum possible 4566 // edit distance. If the minimum isn't good enough, bail out early. 4567 StringRef TypoStr = Typo->getName(); 4568 unsigned MinED = abs((int)Name.size() - (int)TypoStr.size()); 4569 if (MinED && TypoStr.size() / MinED < 3) 4570 return; 4571 4572 // Compute an upper bound on the allowable edit distance, so that the 4573 // edit-distance algorithm can short-circuit. 4574 unsigned UpperBound = (TypoStr.size() + 2) / 3; 4575 unsigned ED = TypoStr.edit_distance(Name, true, UpperBound); 4576 if (ED > UpperBound) return; 4577 4578 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED); 4579 if (isKeyword) TC.makeKeyword(); 4580 TC.setCorrectionRange(nullptr, Result.getLookupNameInfo()); 4581 addCorrection(TC); 4582 } 4583 4584 static const unsigned MaxTypoDistanceResultSets = 5; 4585 4586 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) { 4587 StringRef TypoStr = Typo->getName(); 4588 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName(); 4589 4590 // For very short typos, ignore potential corrections that have a different 4591 // base identifier from the typo or which have a normalized edit distance 4592 // longer than the typo itself. 4593 if (TypoStr.size() < 3 && 4594 (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size())) 4595 return; 4596 4597 // If the correction is resolved but is not viable, ignore it. 4598 if (Correction.isResolved()) { 4599 checkCorrectionVisibility(SemaRef, Correction); 4600 if (!Correction || !isCandidateViable(*CorrectionValidator, Correction)) 4601 return; 4602 } 4603 4604 TypoResultList &CList = 4605 CorrectionResults[Correction.getEditDistance(false)][Name]; 4606 4607 if (!CList.empty() && !CList.back().isResolved()) 4608 CList.pop_back(); 4609 if (NamedDecl *NewND = Correction.getCorrectionDecl()) { 4610 auto RI = llvm::find_if(CList, [NewND](const TypoCorrection &TypoCorr) { 4611 return TypoCorr.getCorrectionDecl() == NewND; 4612 }); 4613 if (RI != CList.end()) { 4614 // The Correction refers to a decl already in the list. No insertion is 4615 // necessary and all further cases will return. 4616 4617 auto IsDeprecated = [](Decl *D) { 4618 while (D) { 4619 if (D->isDeprecated()) 4620 return true; 4621 D = llvm::dyn_cast_or_null<NamespaceDecl>(D->getDeclContext()); 4622 } 4623 return false; 4624 }; 4625 4626 // Prefer non deprecated Corrections over deprecated and only then 4627 // sort using an alphabetical order. 4628 std::pair<bool, std::string> NewKey = { 4629 IsDeprecated(Correction.getFoundDecl()), 4630 Correction.getAsString(SemaRef.getLangOpts())}; 4631 4632 std::pair<bool, std::string> PrevKey = { 4633 IsDeprecated(RI->getFoundDecl()), 4634 RI->getAsString(SemaRef.getLangOpts())}; 4635 4636 if (NewKey < PrevKey) 4637 *RI = Correction; 4638 return; 4639 } 4640 } 4641 if (CList.empty() || Correction.isResolved()) 4642 CList.push_back(Correction); 4643 4644 while (CorrectionResults.size() > MaxTypoDistanceResultSets) 4645 CorrectionResults.erase(std::prev(CorrectionResults.end())); 4646 } 4647 4648 void TypoCorrectionConsumer::addNamespaces( 4649 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) { 4650 SearchNamespaces = true; 4651 4652 for (auto KNPair : KnownNamespaces) 4653 Namespaces.addNameSpecifier(KNPair.first); 4654 4655 bool SSIsTemplate = false; 4656 if (NestedNameSpecifier *NNS = 4657 (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) { 4658 if (const Type *T = NNS->getAsType()) 4659 SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization; 4660 } 4661 // Do not transform this into an iterator-based loop. The loop body can 4662 // trigger the creation of further types (through lazy deserialization) and 4663 // invalid iterators into this list. 4664 auto &Types = SemaRef.getASTContext().getTypes(); 4665 for (unsigned I = 0; I != Types.size(); ++I) { 4666 const auto *TI = Types[I]; 4667 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) { 4668 CD = CD->getCanonicalDecl(); 4669 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() && 4670 !CD->isUnion() && CD->getIdentifier() && 4671 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) && 4672 (CD->isBeingDefined() || CD->isCompleteDefinition())) 4673 Namespaces.addNameSpecifier(CD); 4674 } 4675 } 4676 } 4677 4678 const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() { 4679 if (++CurrentTCIndex < ValidatedCorrections.size()) 4680 return ValidatedCorrections[CurrentTCIndex]; 4681 4682 CurrentTCIndex = ValidatedCorrections.size(); 4683 while (!CorrectionResults.empty()) { 4684 auto DI = CorrectionResults.begin(); 4685 if (DI->second.empty()) { 4686 CorrectionResults.erase(DI); 4687 continue; 4688 } 4689 4690 auto RI = DI->second.begin(); 4691 if (RI->second.empty()) { 4692 DI->second.erase(RI); 4693 performQualifiedLookups(); 4694 continue; 4695 } 4696 4697 TypoCorrection TC = RI->second.pop_back_val(); 4698 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) { 4699 ValidatedCorrections.push_back(TC); 4700 return ValidatedCorrections[CurrentTCIndex]; 4701 } 4702 } 4703 return ValidatedCorrections[0]; // The empty correction. 4704 } 4705 4706 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) { 4707 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo(); 4708 DeclContext *TempMemberContext = MemberContext; 4709 CXXScopeSpec *TempSS = SS.get(); 4710 retry_lookup: 4711 LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext, 4712 EnteringContext, 4713 CorrectionValidator->IsObjCIvarLookup, 4714 Name == Typo && !Candidate.WillReplaceSpecifier()); 4715 switch (Result.getResultKind()) { 4716 case LookupResult::NotFound: 4717 case LookupResult::NotFoundInCurrentInstantiation: 4718 case LookupResult::FoundUnresolvedValue: 4719 if (TempSS) { 4720 // Immediately retry the lookup without the given CXXScopeSpec 4721 TempSS = nullptr; 4722 Candidate.WillReplaceSpecifier(true); 4723 goto retry_lookup; 4724 } 4725 if (TempMemberContext) { 4726 if (SS && !TempSS) 4727 TempSS = SS.get(); 4728 TempMemberContext = nullptr; 4729 goto retry_lookup; 4730 } 4731 if (SearchNamespaces) 4732 QualifiedResults.push_back(Candidate); 4733 break; 4734 4735 case LookupResult::Ambiguous: 4736 // We don't deal with ambiguities. 4737 break; 4738 4739 case LookupResult::Found: 4740 case LookupResult::FoundOverloaded: 4741 // Store all of the Decls for overloaded symbols 4742 for (auto *TRD : Result) 4743 Candidate.addCorrectionDecl(TRD); 4744 checkCorrectionVisibility(SemaRef, Candidate); 4745 if (!isCandidateViable(*CorrectionValidator, Candidate)) { 4746 if (SearchNamespaces) 4747 QualifiedResults.push_back(Candidate); 4748 break; 4749 } 4750 Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo()); 4751 return true; 4752 } 4753 return false; 4754 } 4755 4756 void TypoCorrectionConsumer::performQualifiedLookups() { 4757 unsigned TypoLen = Typo->getName().size(); 4758 for (const TypoCorrection &QR : QualifiedResults) { 4759 for (const auto &NSI : Namespaces) { 4760 DeclContext *Ctx = NSI.DeclCtx; 4761 const Type *NSType = NSI.NameSpecifier->getAsType(); 4762 4763 // If the current NestedNameSpecifier refers to a class and the 4764 // current correction candidate is the name of that class, then skip 4765 // it as it is unlikely a qualified version of the class' constructor 4766 // is an appropriate correction. 4767 if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() : 4768 nullptr) { 4769 if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo()) 4770 continue; 4771 } 4772 4773 TypoCorrection TC(QR); 4774 TC.ClearCorrectionDecls(); 4775 TC.setCorrectionSpecifier(NSI.NameSpecifier); 4776 TC.setQualifierDistance(NSI.EditDistance); 4777 TC.setCallbackDistance(0); // Reset the callback distance 4778 4779 // If the current correction candidate and namespace combination are 4780 // too far away from the original typo based on the normalized edit 4781 // distance, then skip performing a qualified name lookup. 4782 unsigned TmpED = TC.getEditDistance(true); 4783 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED && 4784 TypoLen / TmpED < 3) 4785 continue; 4786 4787 Result.clear(); 4788 Result.setLookupName(QR.getCorrectionAsIdentifierInfo()); 4789 if (!SemaRef.LookupQualifiedName(Result, Ctx)) 4790 continue; 4791 4792 // Any corrections added below will be validated in subsequent 4793 // iterations of the main while() loop over the Consumer's contents. 4794 switch (Result.getResultKind()) { 4795 case LookupResult::Found: 4796 case LookupResult::FoundOverloaded: { 4797 if (SS && SS->isValid()) { 4798 std::string NewQualified = TC.getAsString(SemaRef.getLangOpts()); 4799 std::string OldQualified; 4800 llvm::raw_string_ostream OldOStream(OldQualified); 4801 SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy()); 4802 OldOStream << Typo->getName(); 4803 // If correction candidate would be an identical written qualified 4804 // identifier, then the existing CXXScopeSpec probably included a 4805 // typedef that didn't get accounted for properly. 4806 if (OldOStream.str() == NewQualified) 4807 break; 4808 } 4809 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end(); 4810 TRD != TRDEnd; ++TRD) { 4811 if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(), 4812 NSType ? NSType->getAsCXXRecordDecl() 4813 : nullptr, 4814 TRD.getPair()) == Sema::AR_accessible) 4815 TC.addCorrectionDecl(*TRD); 4816 } 4817 if (TC.isResolved()) { 4818 TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo()); 4819 addCorrection(TC); 4820 } 4821 break; 4822 } 4823 case LookupResult::NotFound: 4824 case LookupResult::NotFoundInCurrentInstantiation: 4825 case LookupResult::Ambiguous: 4826 case LookupResult::FoundUnresolvedValue: 4827 break; 4828 } 4829 } 4830 } 4831 QualifiedResults.clear(); 4832 } 4833 4834 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet( 4835 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec) 4836 : Context(Context), CurContextChain(buildContextChain(CurContext)) { 4837 if (NestedNameSpecifier *NNS = 4838 CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) { 4839 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier); 4840 NNS->print(SpecifierOStream, Context.getPrintingPolicy()); 4841 4842 getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers); 4843 } 4844 // Build the list of identifiers that would be used for an absolute 4845 // (from the global context) NestedNameSpecifier referring to the current 4846 // context. 4847 for (DeclContext *C : llvm::reverse(CurContextChain)) { 4848 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) 4849 CurContextIdentifiers.push_back(ND->getIdentifier()); 4850 } 4851 4852 // Add the global context as a NestedNameSpecifier 4853 SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()), 4854 NestedNameSpecifier::GlobalSpecifier(Context), 1}; 4855 DistanceMap[1].push_back(SI); 4856 } 4857 4858 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain( 4859 DeclContext *Start) -> DeclContextList { 4860 assert(Start && "Building a context chain from a null context"); 4861 DeclContextList Chain; 4862 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr; 4863 DC = DC->getLookupParent()) { 4864 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC); 4865 if (!DC->isInlineNamespace() && !DC->isTransparentContext() && 4866 !(ND && ND->isAnonymousNamespace())) 4867 Chain.push_back(DC->getPrimaryContext()); 4868 } 4869 return Chain; 4870 } 4871 4872 unsigned 4873 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier( 4874 DeclContextList &DeclChain, NestedNameSpecifier *&NNS) { 4875 unsigned NumSpecifiers = 0; 4876 for (DeclContext *C : llvm::reverse(DeclChain)) { 4877 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) { 4878 NNS = NestedNameSpecifier::Create(Context, NNS, ND); 4879 ++NumSpecifiers; 4880 } else if (auto *RD = dyn_cast_or_null<RecordDecl>(C)) { 4881 NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(), 4882 RD->getTypeForDecl()); 4883 ++NumSpecifiers; 4884 } 4885 } 4886 return NumSpecifiers; 4887 } 4888 4889 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier( 4890 DeclContext *Ctx) { 4891 NestedNameSpecifier *NNS = nullptr; 4892 unsigned NumSpecifiers = 0; 4893 DeclContextList NamespaceDeclChain(buildContextChain(Ctx)); 4894 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain); 4895 4896 // Eliminate common elements from the two DeclContext chains. 4897 for (DeclContext *C : llvm::reverse(CurContextChain)) { 4898 if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C) 4899 break; 4900 NamespaceDeclChain.pop_back(); 4901 } 4902 4903 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain 4904 NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS); 4905 4906 // Add an explicit leading '::' specifier if needed. 4907 if (NamespaceDeclChain.empty()) { 4908 // Rebuild the NestedNameSpecifier as a globally-qualified specifier. 4909 NNS = NestedNameSpecifier::GlobalSpecifier(Context); 4910 NumSpecifiers = 4911 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS); 4912 } else if (NamedDecl *ND = 4913 dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) { 4914 IdentifierInfo *Name = ND->getIdentifier(); 4915 bool SameNameSpecifier = false; 4916 if (llvm::is_contained(CurNameSpecifierIdentifiers, Name)) { 4917 std::string NewNameSpecifier; 4918 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier); 4919 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers; 4920 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers); 4921 NNS->print(SpecifierOStream, Context.getPrintingPolicy()); 4922 SpecifierOStream.flush(); 4923 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier; 4924 } 4925 if (SameNameSpecifier || llvm::is_contained(CurContextIdentifiers, Name)) { 4926 // Rebuild the NestedNameSpecifier as a globally-qualified specifier. 4927 NNS = NestedNameSpecifier::GlobalSpecifier(Context); 4928 NumSpecifiers = 4929 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS); 4930 } 4931 } 4932 4933 // If the built NestedNameSpecifier would be replacing an existing 4934 // NestedNameSpecifier, use the number of component identifiers that 4935 // would need to be changed as the edit distance instead of the number 4936 // of components in the built NestedNameSpecifier. 4937 if (NNS && !CurNameSpecifierIdentifiers.empty()) { 4938 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers; 4939 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers); 4940 NumSpecifiers = llvm::ComputeEditDistance( 4941 llvm::makeArrayRef(CurNameSpecifierIdentifiers), 4942 llvm::makeArrayRef(NewNameSpecifierIdentifiers)); 4943 } 4944 4945 SpecifierInfo SI = {Ctx, NNS, NumSpecifiers}; 4946 DistanceMap[NumSpecifiers].push_back(SI); 4947 } 4948 4949 /// Perform name lookup for a possible result for typo correction. 4950 static void LookupPotentialTypoResult(Sema &SemaRef, 4951 LookupResult &Res, 4952 IdentifierInfo *Name, 4953 Scope *S, CXXScopeSpec *SS, 4954 DeclContext *MemberContext, 4955 bool EnteringContext, 4956 bool isObjCIvarLookup, 4957 bool FindHidden) { 4958 Res.suppressDiagnostics(); 4959 Res.clear(); 4960 Res.setLookupName(Name); 4961 Res.setAllowHidden(FindHidden); 4962 if (MemberContext) { 4963 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) { 4964 if (isObjCIvarLookup) { 4965 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) { 4966 Res.addDecl(Ivar); 4967 Res.resolveKind(); 4968 return; 4969 } 4970 } 4971 4972 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration( 4973 Name, ObjCPropertyQueryKind::OBJC_PR_query_instance)) { 4974 Res.addDecl(Prop); 4975 Res.resolveKind(); 4976 return; 4977 } 4978 } 4979 4980 SemaRef.LookupQualifiedName(Res, MemberContext); 4981 return; 4982 } 4983 4984 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false, 4985 EnteringContext); 4986 4987 // Fake ivar lookup; this should really be part of 4988 // LookupParsedName. 4989 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) { 4990 if (Method->isInstanceMethod() && Method->getClassInterface() && 4991 (Res.empty() || 4992 (Res.isSingleResult() && 4993 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) { 4994 if (ObjCIvarDecl *IV 4995 = Method->getClassInterface()->lookupInstanceVariable(Name)) { 4996 Res.addDecl(IV); 4997 Res.resolveKind(); 4998 } 4999 } 5000 } 5001 } 5002 5003 /// Add keywords to the consumer as possible typo corrections. 5004 static void AddKeywordsToConsumer(Sema &SemaRef, 5005 TypoCorrectionConsumer &Consumer, 5006 Scope *S, CorrectionCandidateCallback &CCC, 5007 bool AfterNestedNameSpecifier) { 5008 if (AfterNestedNameSpecifier) { 5009 // For 'X::', we know exactly which keywords can appear next. 5010 Consumer.addKeywordResult("template"); 5011 if (CCC.WantExpressionKeywords) 5012 Consumer.addKeywordResult("operator"); 5013 return; 5014 } 5015 5016 if (CCC.WantObjCSuper) 5017 Consumer.addKeywordResult("super"); 5018 5019 if (CCC.WantTypeSpecifiers) { 5020 // Add type-specifier keywords to the set of results. 5021 static const char *const CTypeSpecs[] = { 5022 "char", "const", "double", "enum", "float", "int", "long", "short", 5023 "signed", "struct", "union", "unsigned", "void", "volatile", 5024 "_Complex", "_Imaginary", 5025 // storage-specifiers as well 5026 "extern", "inline", "static", "typedef" 5027 }; 5028 5029 const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs); 5030 for (unsigned I = 0; I != NumCTypeSpecs; ++I) 5031 Consumer.addKeywordResult(CTypeSpecs[I]); 5032 5033 if (SemaRef.getLangOpts().C99) 5034 Consumer.addKeywordResult("restrict"); 5035 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) 5036 Consumer.addKeywordResult("bool"); 5037 else if (SemaRef.getLangOpts().C99) 5038 Consumer.addKeywordResult("_Bool"); 5039 5040 if (SemaRef.getLangOpts().CPlusPlus) { 5041 Consumer.addKeywordResult("class"); 5042 Consumer.addKeywordResult("typename"); 5043 Consumer.addKeywordResult("wchar_t"); 5044 5045 if (SemaRef.getLangOpts().CPlusPlus11) { 5046 Consumer.addKeywordResult("char16_t"); 5047 Consumer.addKeywordResult("char32_t"); 5048 Consumer.addKeywordResult("constexpr"); 5049 Consumer.addKeywordResult("decltype"); 5050 Consumer.addKeywordResult("thread_local"); 5051 } 5052 } 5053 5054 if (SemaRef.getLangOpts().GNUKeywords) 5055 Consumer.addKeywordResult("typeof"); 5056 } else if (CCC.WantFunctionLikeCasts) { 5057 static const char *const CastableTypeSpecs[] = { 5058 "char", "double", "float", "int", "long", "short", 5059 "signed", "unsigned", "void" 5060 }; 5061 for (auto *kw : CastableTypeSpecs) 5062 Consumer.addKeywordResult(kw); 5063 } 5064 5065 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) { 5066 Consumer.addKeywordResult("const_cast"); 5067 Consumer.addKeywordResult("dynamic_cast"); 5068 Consumer.addKeywordResult("reinterpret_cast"); 5069 Consumer.addKeywordResult("static_cast"); 5070 } 5071 5072 if (CCC.WantExpressionKeywords) { 5073 Consumer.addKeywordResult("sizeof"); 5074 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) { 5075 Consumer.addKeywordResult("false"); 5076 Consumer.addKeywordResult("true"); 5077 } 5078 5079 if (SemaRef.getLangOpts().CPlusPlus) { 5080 static const char *const CXXExprs[] = { 5081 "delete", "new", "operator", "throw", "typeid" 5082 }; 5083 const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs); 5084 for (unsigned I = 0; I != NumCXXExprs; ++I) 5085 Consumer.addKeywordResult(CXXExprs[I]); 5086 5087 if (isa<CXXMethodDecl>(SemaRef.CurContext) && 5088 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance()) 5089 Consumer.addKeywordResult("this"); 5090 5091 if (SemaRef.getLangOpts().CPlusPlus11) { 5092 Consumer.addKeywordResult("alignof"); 5093 Consumer.addKeywordResult("nullptr"); 5094 } 5095 } 5096 5097 if (SemaRef.getLangOpts().C11) { 5098 // FIXME: We should not suggest _Alignof if the alignof macro 5099 // is present. 5100 Consumer.addKeywordResult("_Alignof"); 5101 } 5102 } 5103 5104 if (CCC.WantRemainingKeywords) { 5105 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) { 5106 // Statements. 5107 static const char *const CStmts[] = { 5108 "do", "else", "for", "goto", "if", "return", "switch", "while" }; 5109 const unsigned NumCStmts = llvm::array_lengthof(CStmts); 5110 for (unsigned I = 0; I != NumCStmts; ++I) 5111 Consumer.addKeywordResult(CStmts[I]); 5112 5113 if (SemaRef.getLangOpts().CPlusPlus) { 5114 Consumer.addKeywordResult("catch"); 5115 Consumer.addKeywordResult("try"); 5116 } 5117 5118 if (S && S->getBreakParent()) 5119 Consumer.addKeywordResult("break"); 5120 5121 if (S && S->getContinueParent()) 5122 Consumer.addKeywordResult("continue"); 5123 5124 if (SemaRef.getCurFunction() && 5125 !SemaRef.getCurFunction()->SwitchStack.empty()) { 5126 Consumer.addKeywordResult("case"); 5127 Consumer.addKeywordResult("default"); 5128 } 5129 } else { 5130 if (SemaRef.getLangOpts().CPlusPlus) { 5131 Consumer.addKeywordResult("namespace"); 5132 Consumer.addKeywordResult("template"); 5133 } 5134 5135 if (S && S->isClassScope()) { 5136 Consumer.addKeywordResult("explicit"); 5137 Consumer.addKeywordResult("friend"); 5138 Consumer.addKeywordResult("mutable"); 5139 Consumer.addKeywordResult("private"); 5140 Consumer.addKeywordResult("protected"); 5141 Consumer.addKeywordResult("public"); 5142 Consumer.addKeywordResult("virtual"); 5143 } 5144 } 5145 5146 if (SemaRef.getLangOpts().CPlusPlus) { 5147 Consumer.addKeywordResult("using"); 5148 5149 if (SemaRef.getLangOpts().CPlusPlus11) 5150 Consumer.addKeywordResult("static_assert"); 5151 } 5152 } 5153 } 5154 5155 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer( 5156 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind, 5157 Scope *S, CXXScopeSpec *SS, CorrectionCandidateCallback &CCC, 5158 DeclContext *MemberContext, bool EnteringContext, 5159 const ObjCObjectPointerType *OPT, bool ErrorRecovery) { 5160 5161 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking || 5162 DisableTypoCorrection) 5163 return nullptr; 5164 5165 // In Microsoft mode, don't perform typo correction in a template member 5166 // function dependent context because it interferes with the "lookup into 5167 // dependent bases of class templates" feature. 5168 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() && 5169 isa<CXXMethodDecl>(CurContext)) 5170 return nullptr; 5171 5172 // We only attempt to correct typos for identifiers. 5173 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 5174 if (!Typo) 5175 return nullptr; 5176 5177 // If the scope specifier itself was invalid, don't try to correct 5178 // typos. 5179 if (SS && SS->isInvalid()) 5180 return nullptr; 5181 5182 // Never try to correct typos during any kind of code synthesis. 5183 if (!CodeSynthesisContexts.empty()) 5184 return nullptr; 5185 5186 // Don't try to correct 'super'. 5187 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier()) 5188 return nullptr; 5189 5190 // Abort if typo correction already failed for this specific typo. 5191 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo); 5192 if (locs != TypoCorrectionFailures.end() && 5193 locs->second.count(TypoName.getLoc())) 5194 return nullptr; 5195 5196 // Don't try to correct the identifier "vector" when in AltiVec mode. 5197 // TODO: Figure out why typo correction misbehaves in this case, fix it, and 5198 // remove this workaround. 5199 if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector")) 5200 return nullptr; 5201 5202 // Provide a stop gap for files that are just seriously broken. Trying 5203 // to correct all typos can turn into a HUGE performance penalty, causing 5204 // some files to take minutes to get rejected by the parser. 5205 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit; 5206 if (Limit && TyposCorrected >= Limit) 5207 return nullptr; 5208 ++TyposCorrected; 5209 5210 // If we're handling a missing symbol error, using modules, and the 5211 // special search all modules option is used, look for a missing import. 5212 if (ErrorRecovery && getLangOpts().Modules && 5213 getLangOpts().ModulesSearchAll) { 5214 // The following has the side effect of loading the missing module. 5215 getModuleLoader().lookupMissingImports(Typo->getName(), 5216 TypoName.getBeginLoc()); 5217 } 5218 5219 // Extend the lifetime of the callback. We delayed this until here 5220 // to avoid allocations in the hot path (which is where no typo correction 5221 // occurs). Note that CorrectionCandidateCallback is polymorphic and 5222 // initially stack-allocated. 5223 std::unique_ptr<CorrectionCandidateCallback> ClonedCCC = CCC.clone(); 5224 auto Consumer = std::make_unique<TypoCorrectionConsumer>( 5225 *this, TypoName, LookupKind, S, SS, std::move(ClonedCCC), MemberContext, 5226 EnteringContext); 5227 5228 // Perform name lookup to find visible, similarly-named entities. 5229 bool IsUnqualifiedLookup = false; 5230 DeclContext *QualifiedDC = MemberContext; 5231 if (MemberContext) { 5232 LookupVisibleDecls(MemberContext, LookupKind, *Consumer); 5233 5234 // Look in qualified interfaces. 5235 if (OPT) { 5236 for (auto *I : OPT->quals()) 5237 LookupVisibleDecls(I, LookupKind, *Consumer); 5238 } 5239 } else if (SS && SS->isSet()) { 5240 QualifiedDC = computeDeclContext(*SS, EnteringContext); 5241 if (!QualifiedDC) 5242 return nullptr; 5243 5244 LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer); 5245 } else { 5246 IsUnqualifiedLookup = true; 5247 } 5248 5249 // Determine whether we are going to search in the various namespaces for 5250 // corrections. 5251 bool SearchNamespaces 5252 = getLangOpts().CPlusPlus && 5253 (IsUnqualifiedLookup || (SS && SS->isSet())); 5254 5255 if (IsUnqualifiedLookup || SearchNamespaces) { 5256 // For unqualified lookup, look through all of the names that we have 5257 // seen in this translation unit. 5258 // FIXME: Re-add the ability to skip very unlikely potential corrections. 5259 for (const auto &I : Context.Idents) 5260 Consumer->FoundName(I.getKey()); 5261 5262 // Walk through identifiers in external identifier sources. 5263 // FIXME: Re-add the ability to skip very unlikely potential corrections. 5264 if (IdentifierInfoLookup *External 5265 = Context.Idents.getExternalIdentifierLookup()) { 5266 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers()); 5267 do { 5268 StringRef Name = Iter->Next(); 5269 if (Name.empty()) 5270 break; 5271 5272 Consumer->FoundName(Name); 5273 } while (true); 5274 } 5275 } 5276 5277 AddKeywordsToConsumer(*this, *Consumer, S, 5278 *Consumer->getCorrectionValidator(), 5279 SS && SS->isNotEmpty()); 5280 5281 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going 5282 // to search those namespaces. 5283 if (SearchNamespaces) { 5284 // Load any externally-known namespaces. 5285 if (ExternalSource && !LoadedExternalKnownNamespaces) { 5286 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces; 5287 LoadedExternalKnownNamespaces = true; 5288 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces); 5289 for (auto *N : ExternalKnownNamespaces) 5290 KnownNamespaces[N] = true; 5291 } 5292 5293 Consumer->addNamespaces(KnownNamespaces); 5294 } 5295 5296 return Consumer; 5297 } 5298 5299 /// Try to "correct" a typo in the source code by finding 5300 /// visible declarations whose names are similar to the name that was 5301 /// present in the source code. 5302 /// 5303 /// \param TypoName the \c DeclarationNameInfo structure that contains 5304 /// the name that was present in the source code along with its location. 5305 /// 5306 /// \param LookupKind the name-lookup criteria used to search for the name. 5307 /// 5308 /// \param S the scope in which name lookup occurs. 5309 /// 5310 /// \param SS the nested-name-specifier that precedes the name we're 5311 /// looking for, if present. 5312 /// 5313 /// \param CCC A CorrectionCandidateCallback object that provides further 5314 /// validation of typo correction candidates. It also provides flags for 5315 /// determining the set of keywords permitted. 5316 /// 5317 /// \param MemberContext if non-NULL, the context in which to look for 5318 /// a member access expression. 5319 /// 5320 /// \param EnteringContext whether we're entering the context described by 5321 /// the nested-name-specifier SS. 5322 /// 5323 /// \param OPT when non-NULL, the search for visible declarations will 5324 /// also walk the protocols in the qualified interfaces of \p OPT. 5325 /// 5326 /// \returns a \c TypoCorrection containing the corrected name if the typo 5327 /// along with information such as the \c NamedDecl where the corrected name 5328 /// was declared, and any additional \c NestedNameSpecifier needed to access 5329 /// it (C++ only). The \c TypoCorrection is empty if there is no correction. 5330 TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName, 5331 Sema::LookupNameKind LookupKind, 5332 Scope *S, CXXScopeSpec *SS, 5333 CorrectionCandidateCallback &CCC, 5334 CorrectTypoKind Mode, 5335 DeclContext *MemberContext, 5336 bool EnteringContext, 5337 const ObjCObjectPointerType *OPT, 5338 bool RecordFailure) { 5339 // Always let the ExternalSource have the first chance at correction, even 5340 // if we would otherwise have given up. 5341 if (ExternalSource) { 5342 if (TypoCorrection Correction = 5343 ExternalSource->CorrectTypo(TypoName, LookupKind, S, SS, CCC, 5344 MemberContext, EnteringContext, OPT)) 5345 return Correction; 5346 } 5347 5348 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver; 5349 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for 5350 // some instances of CTC_Unknown, while WantRemainingKeywords is true 5351 // for CTC_Unknown but not for CTC_ObjCMessageReceiver. 5352 bool ObjCMessageReceiver = CCC.WantObjCSuper && !CCC.WantRemainingKeywords; 5353 5354 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 5355 auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC, 5356 MemberContext, EnteringContext, 5357 OPT, Mode == CTK_ErrorRecovery); 5358 5359 if (!Consumer) 5360 return TypoCorrection(); 5361 5362 // If we haven't found anything, we're done. 5363 if (Consumer->empty()) 5364 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5365 5366 // Make sure the best edit distance (prior to adding any namespace qualifiers) 5367 // is not more that about a third of the length of the typo's identifier. 5368 unsigned ED = Consumer->getBestEditDistance(true); 5369 unsigned TypoLen = Typo->getName().size(); 5370 if (ED > 0 && TypoLen / ED < 3) 5371 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5372 5373 TypoCorrection BestTC = Consumer->getNextCorrection(); 5374 TypoCorrection SecondBestTC = Consumer->getNextCorrection(); 5375 if (!BestTC) 5376 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5377 5378 ED = BestTC.getEditDistance(); 5379 5380 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) { 5381 // If this was an unqualified lookup and we believe the callback 5382 // object wouldn't have filtered out possible corrections, note 5383 // that no correction was found. 5384 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5385 } 5386 5387 // If only a single name remains, return that result. 5388 if (!SecondBestTC || 5389 SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) { 5390 const TypoCorrection &Result = BestTC; 5391 5392 // Don't correct to a keyword that's the same as the typo; the keyword 5393 // wasn't actually in scope. 5394 if (ED == 0 && Result.isKeyword()) 5395 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5396 5397 TypoCorrection TC = Result; 5398 TC.setCorrectionRange(SS, TypoName); 5399 checkCorrectionVisibility(*this, TC); 5400 return TC; 5401 } else if (SecondBestTC && ObjCMessageReceiver) { 5402 // Prefer 'super' when we're completing in a message-receiver 5403 // context. 5404 5405 if (BestTC.getCorrection().getAsString() != "super") { 5406 if (SecondBestTC.getCorrection().getAsString() == "super") 5407 BestTC = SecondBestTC; 5408 else if ((*Consumer)["super"].front().isKeyword()) 5409 BestTC = (*Consumer)["super"].front(); 5410 } 5411 // Don't correct to a keyword that's the same as the typo; the keyword 5412 // wasn't actually in scope. 5413 if (BestTC.getEditDistance() == 0 || 5414 BestTC.getCorrection().getAsString() != "super") 5415 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); 5416 5417 BestTC.setCorrectionRange(SS, TypoName); 5418 return BestTC; 5419 } 5420 5421 // Record the failure's location if needed and return an empty correction. If 5422 // this was an unqualified lookup and we believe the callback object did not 5423 // filter out possible corrections, also cache the failure for the typo. 5424 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC); 5425 } 5426 5427 /// Try to "correct" a typo in the source code by finding 5428 /// visible declarations whose names are similar to the name that was 5429 /// present in the source code. 5430 /// 5431 /// \param TypoName the \c DeclarationNameInfo structure that contains 5432 /// the name that was present in the source code along with its location. 5433 /// 5434 /// \param LookupKind the name-lookup criteria used to search for the name. 5435 /// 5436 /// \param S the scope in which name lookup occurs. 5437 /// 5438 /// \param SS the nested-name-specifier that precedes the name we're 5439 /// looking for, if present. 5440 /// 5441 /// \param CCC A CorrectionCandidateCallback object that provides further 5442 /// validation of typo correction candidates. It also provides flags for 5443 /// determining the set of keywords permitted. 5444 /// 5445 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print 5446 /// diagnostics when the actual typo correction is attempted. 5447 /// 5448 /// \param TRC A TypoRecoveryCallback functor that will be used to build an 5449 /// Expr from a typo correction candidate. 5450 /// 5451 /// \param MemberContext if non-NULL, the context in which to look for 5452 /// a member access expression. 5453 /// 5454 /// \param EnteringContext whether we're entering the context described by 5455 /// the nested-name-specifier SS. 5456 /// 5457 /// \param OPT when non-NULL, the search for visible declarations will 5458 /// also walk the protocols in the qualified interfaces of \p OPT. 5459 /// 5460 /// \returns a new \c TypoExpr that will later be replaced in the AST with an 5461 /// Expr representing the result of performing typo correction, or nullptr if 5462 /// typo correction is not possible. If nullptr is returned, no diagnostics will 5463 /// be emitted and it is the responsibility of the caller to emit any that are 5464 /// needed. 5465 TypoExpr *Sema::CorrectTypoDelayed( 5466 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind, 5467 Scope *S, CXXScopeSpec *SS, CorrectionCandidateCallback &CCC, 5468 TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode, 5469 DeclContext *MemberContext, bool EnteringContext, 5470 const ObjCObjectPointerType *OPT) { 5471 auto Consumer = makeTypoCorrectionConsumer(TypoName, LookupKind, S, SS, CCC, 5472 MemberContext, EnteringContext, 5473 OPT, Mode == CTK_ErrorRecovery); 5474 5475 // Give the external sema source a chance to correct the typo. 5476 TypoCorrection ExternalTypo; 5477 if (ExternalSource && Consumer) { 5478 ExternalTypo = ExternalSource->CorrectTypo( 5479 TypoName, LookupKind, S, SS, *Consumer->getCorrectionValidator(), 5480 MemberContext, EnteringContext, OPT); 5481 if (ExternalTypo) 5482 Consumer->addCorrection(ExternalTypo); 5483 } 5484 5485 if (!Consumer || Consumer->empty()) 5486 return nullptr; 5487 5488 // Make sure the best edit distance (prior to adding any namespace qualifiers) 5489 // is not more that about a third of the length of the typo's identifier. 5490 unsigned ED = Consumer->getBestEditDistance(true); 5491 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); 5492 if (!ExternalTypo && ED > 0 && Typo->getName().size() / ED < 3) 5493 return nullptr; 5494 ExprEvalContexts.back().NumTypos++; 5495 return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC), 5496 TypoName.getLoc()); 5497 } 5498 5499 void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) { 5500 if (!CDecl) return; 5501 5502 if (isKeyword()) 5503 CorrectionDecls.clear(); 5504 5505 CorrectionDecls.push_back(CDecl); 5506 5507 if (!CorrectionName) 5508 CorrectionName = CDecl->getDeclName(); 5509 } 5510 5511 std::string TypoCorrection::getAsString(const LangOptions &LO) const { 5512 if (CorrectionNameSpec) { 5513 std::string tmpBuffer; 5514 llvm::raw_string_ostream PrefixOStream(tmpBuffer); 5515 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO)); 5516 PrefixOStream << CorrectionName; 5517 return PrefixOStream.str(); 5518 } 5519 5520 return CorrectionName.getAsString(); 5521 } 5522 5523 bool CorrectionCandidateCallback::ValidateCandidate( 5524 const TypoCorrection &candidate) { 5525 if (!candidate.isResolved()) 5526 return true; 5527 5528 if (candidate.isKeyword()) 5529 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts || 5530 WantRemainingKeywords || WantObjCSuper; 5531 5532 bool HasNonType = false; 5533 bool HasStaticMethod = false; 5534 bool HasNonStaticMethod = false; 5535 for (Decl *D : candidate) { 5536 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D)) 5537 D = FTD->getTemplatedDecl(); 5538 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 5539 if (Method->isStatic()) 5540 HasStaticMethod = true; 5541 else 5542 HasNonStaticMethod = true; 5543 } 5544 if (!isa<TypeDecl>(D)) 5545 HasNonType = true; 5546 } 5547 5548 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod && 5549 !candidate.getCorrectionSpecifier()) 5550 return false; 5551 5552 return WantTypeSpecifiers || HasNonType; 5553 } 5554 5555 FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs, 5556 bool HasExplicitTemplateArgs, 5557 MemberExpr *ME) 5558 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs), 5559 CurContext(SemaRef.CurContext), MemberFn(ME) { 5560 WantTypeSpecifiers = false; 5561 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && 5562 !HasExplicitTemplateArgs && NumArgs == 1; 5563 WantCXXNamedCasts = HasExplicitTemplateArgs && NumArgs == 1; 5564 WantRemainingKeywords = false; 5565 } 5566 5567 bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) { 5568 if (!candidate.getCorrectionDecl()) 5569 return candidate.isKeyword(); 5570 5571 for (auto *C : candidate) { 5572 FunctionDecl *FD = nullptr; 5573 NamedDecl *ND = C->getUnderlyingDecl(); 5574 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 5575 FD = FTD->getTemplatedDecl(); 5576 if (!HasExplicitTemplateArgs && !FD) { 5577 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) { 5578 // If the Decl is neither a function nor a template function, 5579 // determine if it is a pointer or reference to a function. If so, 5580 // check against the number of arguments expected for the pointee. 5581 QualType ValType = cast<ValueDecl>(ND)->getType(); 5582 if (ValType.isNull()) 5583 continue; 5584 if (ValType->isAnyPointerType() || ValType->isReferenceType()) 5585 ValType = ValType->getPointeeType(); 5586 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>()) 5587 if (FPT->getNumParams() == NumArgs) 5588 return true; 5589 } 5590 } 5591 5592 // A typo for a function-style cast can look like a function call in C++. 5593 if ((HasExplicitTemplateArgs ? getAsTypeTemplateDecl(ND) != nullptr 5594 : isa<TypeDecl>(ND)) && 5595 CurContext->getParentASTContext().getLangOpts().CPlusPlus) 5596 // Only a class or class template can take two or more arguments. 5597 return NumArgs <= 1 || HasExplicitTemplateArgs || isa<CXXRecordDecl>(ND); 5598 5599 // Skip the current candidate if it is not a FunctionDecl or does not accept 5600 // the current number of arguments. 5601 if (!FD || !(FD->getNumParams() >= NumArgs && 5602 FD->getMinRequiredArguments() <= NumArgs)) 5603 continue; 5604 5605 // If the current candidate is a non-static C++ method, skip the candidate 5606 // unless the method being corrected--or the current DeclContext, if the 5607 // function being corrected is not a method--is a method in the same class 5608 // or a descendent class of the candidate's parent class. 5609 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) { 5610 if (MemberFn || !MD->isStatic()) { 5611 CXXMethodDecl *CurMD = 5612 MemberFn 5613 ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl()) 5614 : dyn_cast_or_null<CXXMethodDecl>(CurContext); 5615 CXXRecordDecl *CurRD = 5616 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr; 5617 CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl(); 5618 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD))) 5619 continue; 5620 } 5621 } 5622 return true; 5623 } 5624 return false; 5625 } 5626 5627 void Sema::diagnoseTypo(const TypoCorrection &Correction, 5628 const PartialDiagnostic &TypoDiag, 5629 bool ErrorRecovery) { 5630 diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl), 5631 ErrorRecovery); 5632 } 5633 5634 /// Find which declaration we should import to provide the definition of 5635 /// the given declaration. 5636 static NamedDecl *getDefinitionToImport(NamedDecl *D) { 5637 if (VarDecl *VD = dyn_cast<VarDecl>(D)) 5638 return VD->getDefinition(); 5639 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) 5640 return FD->getDefinition(); 5641 if (TagDecl *TD = dyn_cast<TagDecl>(D)) 5642 return TD->getDefinition(); 5643 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D)) 5644 return ID->getDefinition(); 5645 if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D)) 5646 return PD->getDefinition(); 5647 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D)) 5648 if (NamedDecl *TTD = TD->getTemplatedDecl()) 5649 return getDefinitionToImport(TTD); 5650 return nullptr; 5651 } 5652 5653 void Sema::diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl, 5654 MissingImportKind MIK, bool Recover) { 5655 // Suggest importing a module providing the definition of this entity, if 5656 // possible. 5657 NamedDecl *Def = getDefinitionToImport(Decl); 5658 if (!Def) 5659 Def = Decl; 5660 5661 Module *Owner = getOwningModule(Def); 5662 assert(Owner && "definition of hidden declaration is not in a module"); 5663 5664 llvm::SmallVector<Module*, 8> OwningModules; 5665 OwningModules.push_back(Owner); 5666 auto Merged = Context.getModulesWithMergedDefinition(Def); 5667 OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end()); 5668 5669 diagnoseMissingImport(Loc, Def, Def->getLocation(), OwningModules, MIK, 5670 Recover); 5671 } 5672 5673 /// Get a "quoted.h" or <angled.h> include path to use in a diagnostic 5674 /// suggesting the addition of a #include of the specified file. 5675 static std::string getHeaderNameForHeader(Preprocessor &PP, const FileEntry *E, 5676 llvm::StringRef IncludingFile) { 5677 bool IsSystem = false; 5678 auto Path = PP.getHeaderSearchInfo().suggestPathToFileForDiagnostics( 5679 E, IncludingFile, &IsSystem); 5680 return (IsSystem ? '<' : '"') + Path + (IsSystem ? '>' : '"'); 5681 } 5682 5683 void Sema::diagnoseMissingImport(SourceLocation UseLoc, NamedDecl *Decl, 5684 SourceLocation DeclLoc, 5685 ArrayRef<Module *> Modules, 5686 MissingImportKind MIK, bool Recover) { 5687 assert(!Modules.empty()); 5688 5689 auto NotePrevious = [&] { 5690 // FIXME: Suppress the note backtrace even under 5691 // -fdiagnostics-show-note-include-stack. We don't care how this 5692 // declaration was previously reached. 5693 Diag(DeclLoc, diag::note_unreachable_entity) << (int)MIK; 5694 }; 5695 5696 // Weed out duplicates from module list. 5697 llvm::SmallVector<Module*, 8> UniqueModules; 5698 llvm::SmallDenseSet<Module*, 8> UniqueModuleSet; 5699 for (auto *M : Modules) { 5700 if (M->Kind == Module::GlobalModuleFragment) 5701 continue; 5702 if (UniqueModuleSet.insert(M).second) 5703 UniqueModules.push_back(M); 5704 } 5705 5706 // Try to find a suitable header-name to #include. 5707 std::string HeaderName; 5708 if (const FileEntry *Header = 5709 PP.getHeaderToIncludeForDiagnostics(UseLoc, DeclLoc)) { 5710 if (const FileEntry *FE = 5711 SourceMgr.getFileEntryForID(SourceMgr.getFileID(UseLoc))) 5712 HeaderName = getHeaderNameForHeader(PP, Header, FE->tryGetRealPathName()); 5713 } 5714 5715 // If we have a #include we should suggest, or if all definition locations 5716 // were in global module fragments, don't suggest an import. 5717 if (!HeaderName.empty() || UniqueModules.empty()) { 5718 // FIXME: Find a smart place to suggest inserting a #include, and add 5719 // a FixItHint there. 5720 Diag(UseLoc, diag::err_module_unimported_use_header) 5721 << (int)MIK << Decl << !HeaderName.empty() << HeaderName; 5722 // Produce a note showing where the entity was declared. 5723 NotePrevious(); 5724 if (Recover) 5725 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]); 5726 return; 5727 } 5728 5729 Modules = UniqueModules; 5730 5731 if (Modules.size() > 1) { 5732 std::string ModuleList; 5733 unsigned N = 0; 5734 for (Module *M : Modules) { 5735 ModuleList += "\n "; 5736 if (++N == 5 && N != Modules.size()) { 5737 ModuleList += "[...]"; 5738 break; 5739 } 5740 ModuleList += M->getFullModuleName(); 5741 } 5742 5743 Diag(UseLoc, diag::err_module_unimported_use_multiple) 5744 << (int)MIK << Decl << ModuleList; 5745 } else { 5746 // FIXME: Add a FixItHint that imports the corresponding module. 5747 Diag(UseLoc, diag::err_module_unimported_use) 5748 << (int)MIK << Decl << Modules[0]->getFullModuleName(); 5749 } 5750 5751 NotePrevious(); 5752 5753 // Try to recover by implicitly importing this module. 5754 if (Recover) 5755 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]); 5756 } 5757 5758 /// Diagnose a successfully-corrected typo. Separated from the correction 5759 /// itself to allow external validation of the result, etc. 5760 /// 5761 /// \param Correction The result of performing typo correction. 5762 /// \param TypoDiag The diagnostic to produce. This will have the corrected 5763 /// string added to it (and usually also a fixit). 5764 /// \param PrevNote A note to use when indicating the location of the entity to 5765 /// which we are correcting. Will have the correction string added to it. 5766 /// \param ErrorRecovery If \c true (the default), the caller is going to 5767 /// recover from the typo as if the corrected string had been typed. 5768 /// In this case, \c PDiag must be an error, and we will attach a fixit 5769 /// to it. 5770 void Sema::diagnoseTypo(const TypoCorrection &Correction, 5771 const PartialDiagnostic &TypoDiag, 5772 const PartialDiagnostic &PrevNote, 5773 bool ErrorRecovery) { 5774 std::string CorrectedStr = Correction.getAsString(getLangOpts()); 5775 std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts()); 5776 FixItHint FixTypo = FixItHint::CreateReplacement( 5777 Correction.getCorrectionRange(), CorrectedStr); 5778 5779 // Maybe we're just missing a module import. 5780 if (Correction.requiresImport()) { 5781 NamedDecl *Decl = Correction.getFoundDecl(); 5782 assert(Decl && "import required but no declaration to import"); 5783 5784 diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl, 5785 MissingImportKind::Declaration, ErrorRecovery); 5786 return; 5787 } 5788 5789 Diag(Correction.getCorrectionRange().getBegin(), TypoDiag) 5790 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint()); 5791 5792 NamedDecl *ChosenDecl = 5793 Correction.isKeyword() ? nullptr : Correction.getFoundDecl(); 5794 if (PrevNote.getDiagID() && ChosenDecl) 5795 Diag(ChosenDecl->getLocation(), PrevNote) 5796 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo); 5797 5798 // Add any extra diagnostics. 5799 for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics()) 5800 Diag(Correction.getCorrectionRange().getBegin(), PD); 5801 } 5802 5803 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC, 5804 TypoDiagnosticGenerator TDG, 5805 TypoRecoveryCallback TRC, 5806 SourceLocation TypoLoc) { 5807 assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer"); 5808 auto TE = new (Context) TypoExpr(Context.DependentTy, TypoLoc); 5809 auto &State = DelayedTypos[TE]; 5810 State.Consumer = std::move(TCC); 5811 State.DiagHandler = std::move(TDG); 5812 State.RecoveryHandler = std::move(TRC); 5813 if (TE) 5814 TypoExprs.push_back(TE); 5815 return TE; 5816 } 5817 5818 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const { 5819 auto Entry = DelayedTypos.find(TE); 5820 assert(Entry != DelayedTypos.end() && 5821 "Failed to get the state for a TypoExpr!"); 5822 return Entry->second; 5823 } 5824 5825 void Sema::clearDelayedTypo(TypoExpr *TE) { 5826 DelayedTypos.erase(TE); 5827 } 5828 5829 void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) { 5830 DeclarationNameInfo Name(II, IILoc); 5831 LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration); 5832 R.suppressDiagnostics(); 5833 R.setHideTags(false); 5834 LookupName(R, S); 5835 R.dump(); 5836 } 5837