SemaLookup.cpp revision c03d3303fb298ae86bf5d5d6c98755928fdbde00
1//===--------------------- SemaLookup.cpp - Name Lookup ------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements name lookup for C, C++, Objective-C, and 11// Objective-C++. 12// 13//===----------------------------------------------------------------------===// 14#include "Sema.h" 15#include "SemaInherit.h" 16#include "clang/AST/ASTContext.h" 17#include "clang/AST/Decl.h" 18#include "clang/AST/DeclCXX.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/Parse/DeclSpec.h" 24#include "clang/Basic/Builtins.h" 25#include "clang/Basic/LangOptions.h" 26#include "llvm/ADT/STLExtras.h" 27#include "llvm/ADT/SmallPtrSet.h" 28#include <set> 29#include <vector> 30#include <iterator> 31#include <utility> 32#include <algorithm> 33 34using namespace clang; 35 36typedef llvm::SmallVector<UsingDirectiveDecl*, 4> UsingDirectivesTy; 37typedef llvm::DenseSet<NamespaceDecl*> NamespaceSet; 38typedef llvm::SmallVector<Sema::LookupResult, 3> LookupResultsTy; 39 40/// UsingDirAncestorCompare - Implements strict weak ordering of 41/// UsingDirectives. It orders them by address of its common ancestor. 42struct UsingDirAncestorCompare { 43 44 /// @brief Compares UsingDirectiveDecl common ancestor with DeclContext. 45 bool operator () (UsingDirectiveDecl *U, const DeclContext *Ctx) const { 46 return U->getCommonAncestor() < Ctx; 47 } 48 49 /// @brief Compares UsingDirectiveDecl common ancestor with DeclContext. 50 bool operator () (const DeclContext *Ctx, UsingDirectiveDecl *U) const { 51 return Ctx < U->getCommonAncestor(); 52 } 53 54 /// @brief Compares UsingDirectiveDecl common ancestors. 55 bool operator () (UsingDirectiveDecl *U1, UsingDirectiveDecl *U2) const { 56 return U1->getCommonAncestor() < U2->getCommonAncestor(); 57 } 58}; 59 60/// AddNamespaceUsingDirectives - Adds all UsingDirectiveDecl's to heap UDirs 61/// (ordered by common ancestors), found in namespace NS, 62/// including all found (recursively) in their nominated namespaces. 63void AddNamespaceUsingDirectives(ASTContext &Context, 64 DeclContext *NS, 65 UsingDirectivesTy &UDirs, 66 NamespaceSet &Visited) { 67 DeclContext::udir_iterator I, End; 68 69 for (llvm::tie(I, End) = NS->getUsingDirectives(); I !=End; ++I) { 70 UDirs.push_back(*I); 71 std::push_heap(UDirs.begin(), UDirs.end(), UsingDirAncestorCompare()); 72 NamespaceDecl *Nominated = (*I)->getNominatedNamespace(); 73 if (Visited.insert(Nominated).second) 74 AddNamespaceUsingDirectives(Context, Nominated, UDirs, /*ref*/ Visited); 75 } 76} 77 78/// AddScopeUsingDirectives - Adds all UsingDirectiveDecl's found in Scope S, 79/// including all found in the namespaces they nominate. 80static void AddScopeUsingDirectives(ASTContext &Context, Scope *S, 81 UsingDirectivesTy &UDirs) { 82 NamespaceSet VisitedNS; 83 84 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) { 85 86 if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(Ctx)) 87 VisitedNS.insert(NS); 88 89 AddNamespaceUsingDirectives(Context, Ctx, UDirs, /*ref*/ VisitedNS); 90 91 } else { 92 Scope::udir_iterator I = S->using_directives_begin(), 93 End = S->using_directives_end(); 94 95 for (; I != End; ++I) { 96 UsingDirectiveDecl *UD = I->getAs<UsingDirectiveDecl>(); 97 UDirs.push_back(UD); 98 std::push_heap(UDirs.begin(), UDirs.end(), UsingDirAncestorCompare()); 99 100 NamespaceDecl *Nominated = UD->getNominatedNamespace(); 101 if (!VisitedNS.count(Nominated)) { 102 VisitedNS.insert(Nominated); 103 AddNamespaceUsingDirectives(Context, Nominated, UDirs, 104 /*ref*/ VisitedNS); 105 } 106 } 107 } 108} 109 110/// MaybeConstructOverloadSet - Name lookup has determined that the 111/// elements in [I, IEnd) have the name that we are looking for, and 112/// *I is a match for the namespace. This routine returns an 113/// appropriate Decl for name lookup, which may either be *I or an 114/// OverloadedFunctionDecl that represents the overloaded functions in 115/// [I, IEnd). 116/// 117/// The existance of this routine is temporary; users of LookupResult 118/// should be able to handle multiple results, to deal with cases of 119/// ambiguity and overloaded functions without needing to create a 120/// Decl node. 121template<typename DeclIterator> 122static NamedDecl * 123MaybeConstructOverloadSet(ASTContext &Context, 124 DeclIterator I, DeclIterator IEnd) { 125 assert(I != IEnd && "Iterator range cannot be empty"); 126 assert(!isa<OverloadedFunctionDecl>(*I) && 127 "Cannot have an overloaded function"); 128 129 if ((*I)->isFunctionOrFunctionTemplate()) { 130 // If we found a function, there might be more functions. If 131 // so, collect them into an overload set. 132 DeclIterator Last = I; 133 OverloadedFunctionDecl *Ovl = 0; 134 for (++Last; 135 Last != IEnd && (*Last)->isFunctionOrFunctionTemplate(); 136 ++Last) { 137 if (!Ovl) { 138 // FIXME: We leak this overload set. Eventually, we want to stop 139 // building the declarations for these overload sets, so there will be 140 // nothing to leak. 141 Ovl = OverloadedFunctionDecl::Create(Context, (*I)->getDeclContext(), 142 (*I)->getDeclName()); 143 NamedDecl *ND = (*I)->getUnderlyingDecl(); 144 if (isa<FunctionDecl>(ND)) 145 Ovl->addOverload(cast<FunctionDecl>(ND)); 146 else 147 Ovl->addOverload(cast<FunctionTemplateDecl>(ND)); 148 } 149 150 NamedDecl *ND = (*Last)->getUnderlyingDecl(); 151 if (isa<FunctionDecl>(ND)) 152 Ovl->addOverload(cast<FunctionDecl>(ND)); 153 else 154 Ovl->addOverload(cast<FunctionTemplateDecl>(ND)); 155 } 156 157 // If we had more than one function, we built an overload 158 // set. Return it. 159 if (Ovl) 160 return Ovl; 161 } 162 163 return *I; 164} 165 166/// Merges together multiple LookupResults dealing with duplicated Decl's. 167static Sema::LookupResult 168MergeLookupResults(ASTContext &Context, LookupResultsTy &Results) { 169 typedef Sema::LookupResult LResult; 170 typedef llvm::SmallPtrSet<NamedDecl*, 4> DeclsSetTy; 171 172 // Remove duplicated Decl pointing at same Decl, by storing them in 173 // associative collection. This might be case for code like: 174 // 175 // namespace A { int i; } 176 // namespace B { using namespace A; } 177 // namespace C { using namespace A; } 178 // 179 // void foo() { 180 // using namespace B; 181 // using namespace C; 182 // ++i; // finds A::i, from both namespace B and C at global scope 183 // } 184 // 185 // C++ [namespace.qual].p3: 186 // The same declaration found more than once is not an ambiguity 187 // (because it is still a unique declaration). 188 DeclsSetTy FoundDecls; 189 190 // Counter of tag names, and functions for resolving ambiguity 191 // and name hiding. 192 std::size_t TagNames = 0, Functions = 0, OrdinaryNonFunc = 0; 193 194 LookupResultsTy::iterator I = Results.begin(), End = Results.end(); 195 196 // No name lookup results, return early. 197 if (I == End) return LResult::CreateLookupResult(Context, 0); 198 199 // Keep track of the tag declaration we found. We only use this if 200 // we find a single tag declaration. 201 TagDecl *TagFound = 0; 202 203 for (; I != End; ++I) { 204 switch (I->getKind()) { 205 case LResult::NotFound: 206 assert(false && 207 "Should be always successful name lookup result here."); 208 break; 209 210 case LResult::AmbiguousReference: 211 case LResult::AmbiguousBaseSubobjectTypes: 212 case LResult::AmbiguousBaseSubobjects: 213 assert(false && "Shouldn't get ambiguous lookup here."); 214 break; 215 216 case LResult::Found: { 217 NamedDecl *ND = I->getAsDecl()->getUnderlyingDecl(); 218 219 if (TagDecl *TD = dyn_cast<TagDecl>(ND)) { 220 TagFound = TD->getCanonicalDecl(); 221 TagNames += FoundDecls.insert(TagFound)? 1 : 0; 222 } else if (ND->isFunctionOrFunctionTemplate()) 223 Functions += FoundDecls.insert(ND)? 1 : 0; 224 else 225 FoundDecls.insert(ND); 226 break; 227 } 228 229 case LResult::FoundOverloaded: 230 for (LResult::iterator FI = I->begin(), FEnd = I->end(); FI != FEnd; ++FI) 231 Functions += FoundDecls.insert(*FI)? 1 : 0; 232 break; 233 } 234 } 235 OrdinaryNonFunc = FoundDecls.size() - TagNames - Functions; 236 bool Ambiguous = false, NameHidesTags = false; 237 238 if (FoundDecls.size() == 1) { 239 // 1) Exactly one result. 240 } else if (TagNames > 1) { 241 // 2) Multiple tag names (even though they may be hidden by an 242 // object name). 243 Ambiguous = true; 244 } else if (FoundDecls.size() - TagNames == 1) { 245 // 3) Ordinary name hides (optional) tag. 246 NameHidesTags = TagFound; 247 } else if (Functions) { 248 // C++ [basic.lookup].p1: 249 // ... Name lookup may associate more than one declaration with 250 // a name if it finds the name to be a function name; the declarations 251 // are said to form a set of overloaded functions (13.1). 252 // Overload resolution (13.3) takes place after name lookup has succeeded. 253 // 254 if (!OrdinaryNonFunc) { 255 // 4) Functions hide tag names. 256 NameHidesTags = TagFound; 257 } else { 258 // 5) Functions + ordinary names. 259 Ambiguous = true; 260 } 261 } else { 262 // 6) Multiple non-tag names 263 Ambiguous = true; 264 } 265 266 if (Ambiguous) 267 return LResult::CreateLookupResult(Context, 268 FoundDecls.begin(), FoundDecls.size()); 269 if (NameHidesTags) { 270 // There's only one tag, TagFound. Remove it. 271 assert(TagFound && FoundDecls.count(TagFound) && "No tag name found?"); 272 FoundDecls.erase(TagFound); 273 } 274 275 // Return successful name lookup result. 276 return LResult::CreateLookupResult(Context, 277 MaybeConstructOverloadSet(Context, 278 FoundDecls.begin(), 279 FoundDecls.end())); 280} 281 282// Retrieve the set of identifier namespaces that correspond to a 283// specific kind of name lookup. 284inline unsigned 285getIdentifierNamespacesFromLookupNameKind(Sema::LookupNameKind NameKind, 286 bool CPlusPlus) { 287 unsigned IDNS = 0; 288 switch (NameKind) { 289 case Sema::LookupOrdinaryName: 290 case Sema::LookupOperatorName: 291 case Sema::LookupRedeclarationWithLinkage: 292 IDNS = Decl::IDNS_Ordinary; 293 if (CPlusPlus) 294 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member; 295 break; 296 297 case Sema::LookupTagName: 298 IDNS = Decl::IDNS_Tag; 299 break; 300 301 case Sema::LookupMemberName: 302 IDNS = Decl::IDNS_Member; 303 if (CPlusPlus) 304 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary; 305 break; 306 307 case Sema::LookupNestedNameSpecifierName: 308 case Sema::LookupNamespaceName: 309 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member; 310 break; 311 312 case Sema::LookupObjCProtocolName: 313 IDNS = Decl::IDNS_ObjCProtocol; 314 break; 315 316 case Sema::LookupObjCImplementationName: 317 IDNS = Decl::IDNS_ObjCImplementation; 318 break; 319 320 case Sema::LookupObjCCategoryImplName: 321 IDNS = Decl::IDNS_ObjCCategoryImpl; 322 break; 323 } 324 return IDNS; 325} 326 327Sema::LookupResult 328Sema::LookupResult::CreateLookupResult(ASTContext &Context, NamedDecl *D) { 329 if (D) 330 D = D->getUnderlyingDecl(); 331 332 LookupResult Result; 333 Result.StoredKind = (D && isa<OverloadedFunctionDecl>(D))? 334 OverloadedDeclSingleDecl : SingleDecl; 335 Result.First = reinterpret_cast<uintptr_t>(D); 336 Result.Last = 0; 337 Result.Context = &Context; 338 return Result; 339} 340 341/// @brief Moves the name-lookup results from Other to this LookupResult. 342Sema::LookupResult 343Sema::LookupResult::CreateLookupResult(ASTContext &Context, 344 IdentifierResolver::iterator F, 345 IdentifierResolver::iterator L) { 346 LookupResult Result; 347 Result.Context = &Context; 348 349 if (F != L && (*F)->isFunctionOrFunctionTemplate()) { 350 IdentifierResolver::iterator Next = F; 351 ++Next; 352 if (Next != L && (*Next)->isFunctionOrFunctionTemplate()) { 353 Result.StoredKind = OverloadedDeclFromIdResolver; 354 Result.First = F.getAsOpaqueValue(); 355 Result.Last = L.getAsOpaqueValue(); 356 return Result; 357 } 358 } 359 360 NamedDecl *D = *F; 361 if (D) 362 D = D->getUnderlyingDecl(); 363 364 Result.StoredKind = SingleDecl; 365 Result.First = reinterpret_cast<uintptr_t>(D); 366 Result.Last = 0; 367 return Result; 368} 369 370Sema::LookupResult 371Sema::LookupResult::CreateLookupResult(ASTContext &Context, 372 DeclContext::lookup_iterator F, 373 DeclContext::lookup_iterator L) { 374 LookupResult Result; 375 Result.Context = &Context; 376 377 if (F != L && (*F)->isFunctionOrFunctionTemplate()) { 378 DeclContext::lookup_iterator Next = F; 379 ++Next; 380 if (Next != L && (*Next)->isFunctionOrFunctionTemplate()) { 381 Result.StoredKind = OverloadedDeclFromDeclContext; 382 Result.First = reinterpret_cast<uintptr_t>(F); 383 Result.Last = reinterpret_cast<uintptr_t>(L); 384 return Result; 385 } 386 } 387 388 NamedDecl *D = *F; 389 if (D) 390 D = D->getUnderlyingDecl(); 391 392 Result.StoredKind = SingleDecl; 393 Result.First = reinterpret_cast<uintptr_t>(D); 394 Result.Last = 0; 395 return Result; 396} 397 398/// @brief Determine the result of name lookup. 399Sema::LookupResult::LookupKind Sema::LookupResult::getKind() const { 400 switch (StoredKind) { 401 case SingleDecl: 402 return (reinterpret_cast<Decl *>(First) != 0)? Found : NotFound; 403 404 case OverloadedDeclSingleDecl: 405 case OverloadedDeclFromIdResolver: 406 case OverloadedDeclFromDeclContext: 407 return FoundOverloaded; 408 409 case AmbiguousLookupStoresBasePaths: 410 return Last? AmbiguousBaseSubobjectTypes : AmbiguousBaseSubobjects; 411 412 case AmbiguousLookupStoresDecls: 413 return AmbiguousReference; 414 } 415 416 // We can't ever get here. 417 return NotFound; 418} 419 420/// @brief Converts the result of name lookup into a single (possible 421/// NULL) pointer to a declaration. 422/// 423/// The resulting declaration will either be the declaration we found 424/// (if only a single declaration was found), an 425/// OverloadedFunctionDecl (if an overloaded function was found), or 426/// NULL (if no declaration was found). This conversion must not be 427/// used anywhere where name lookup could result in an ambiguity. 428/// 429/// The OverloadedFunctionDecl conversion is meant as a stop-gap 430/// solution, since it causes the OverloadedFunctionDecl to be 431/// leaked. FIXME: Eventually, there will be a better way to iterate 432/// over the set of overloaded functions returned by name lookup. 433NamedDecl *Sema::LookupResult::getAsDecl() const { 434 switch (StoredKind) { 435 case SingleDecl: 436 return reinterpret_cast<NamedDecl *>(First); 437 438 case OverloadedDeclFromIdResolver: 439 return MaybeConstructOverloadSet(*Context, 440 IdentifierResolver::iterator::getFromOpaqueValue(First), 441 IdentifierResolver::iterator::getFromOpaqueValue(Last)); 442 443 case OverloadedDeclFromDeclContext: 444 return MaybeConstructOverloadSet(*Context, 445 reinterpret_cast<DeclContext::lookup_iterator>(First), 446 reinterpret_cast<DeclContext::lookup_iterator>(Last)); 447 448 case OverloadedDeclSingleDecl: 449 return reinterpret_cast<OverloadedFunctionDecl*>(First); 450 451 case AmbiguousLookupStoresDecls: 452 case AmbiguousLookupStoresBasePaths: 453 assert(false && 454 "Name lookup returned an ambiguity that could not be handled"); 455 break; 456 } 457 458 return 0; 459} 460 461/// @brief Retrieves the BasePaths structure describing an ambiguous 462/// name lookup, or null. 463BasePaths *Sema::LookupResult::getBasePaths() const { 464 if (StoredKind == AmbiguousLookupStoresBasePaths) 465 return reinterpret_cast<BasePaths *>(First); 466 return 0; 467} 468 469Sema::LookupResult::iterator::reference 470Sema::LookupResult::iterator::operator*() const { 471 switch (Result->StoredKind) { 472 case SingleDecl: 473 return reinterpret_cast<NamedDecl*>(Current); 474 475 case OverloadedDeclSingleDecl: 476 return *reinterpret_cast<NamedDecl**>(Current); 477 478 case OverloadedDeclFromIdResolver: 479 return *IdentifierResolver::iterator::getFromOpaqueValue(Current); 480 481 case AmbiguousLookupStoresBasePaths: 482 if (Result->Last) 483 return *reinterpret_cast<NamedDecl**>(Current); 484 485 // Fall through to handle the DeclContext::lookup_iterator we're 486 // storing. 487 488 case OverloadedDeclFromDeclContext: 489 case AmbiguousLookupStoresDecls: 490 return *reinterpret_cast<DeclContext::lookup_iterator>(Current); 491 } 492 493 return 0; 494} 495 496Sema::LookupResult::iterator& Sema::LookupResult::iterator::operator++() { 497 switch (Result->StoredKind) { 498 case SingleDecl: 499 Current = reinterpret_cast<uintptr_t>((NamedDecl*)0); 500 break; 501 502 case OverloadedDeclSingleDecl: { 503 NamedDecl ** I = reinterpret_cast<NamedDecl**>(Current); 504 ++I; 505 Current = reinterpret_cast<uintptr_t>(I); 506 break; 507 } 508 509 case OverloadedDeclFromIdResolver: { 510 IdentifierResolver::iterator I 511 = IdentifierResolver::iterator::getFromOpaqueValue(Current); 512 ++I; 513 Current = I.getAsOpaqueValue(); 514 break; 515 } 516 517 case AmbiguousLookupStoresBasePaths: 518 if (Result->Last) { 519 NamedDecl ** I = reinterpret_cast<NamedDecl**>(Current); 520 ++I; 521 Current = reinterpret_cast<uintptr_t>(I); 522 break; 523 } 524 // Fall through to handle the DeclContext::lookup_iterator we're 525 // storing. 526 527 case OverloadedDeclFromDeclContext: 528 case AmbiguousLookupStoresDecls: { 529 DeclContext::lookup_iterator I 530 = reinterpret_cast<DeclContext::lookup_iterator>(Current); 531 ++I; 532 Current = reinterpret_cast<uintptr_t>(I); 533 break; 534 } 535 } 536 537 return *this; 538} 539 540Sema::LookupResult::iterator Sema::LookupResult::begin() { 541 switch (StoredKind) { 542 case SingleDecl: 543 case OverloadedDeclFromIdResolver: 544 case OverloadedDeclFromDeclContext: 545 case AmbiguousLookupStoresDecls: 546 return iterator(this, First); 547 548 case OverloadedDeclSingleDecl: { 549 OverloadedFunctionDecl * Ovl = 550 reinterpret_cast<OverloadedFunctionDecl*>(First); 551 return iterator(this, 552 reinterpret_cast<uintptr_t>(&(*Ovl->function_begin()))); 553 } 554 555 case AmbiguousLookupStoresBasePaths: 556 if (Last) 557 return iterator(this, 558 reinterpret_cast<uintptr_t>(getBasePaths()->found_decls_begin())); 559 else 560 return iterator(this, 561 reinterpret_cast<uintptr_t>(getBasePaths()->front().Decls.first)); 562 } 563 564 // Required to suppress GCC warning. 565 return iterator(); 566} 567 568Sema::LookupResult::iterator Sema::LookupResult::end() { 569 switch (StoredKind) { 570 case SingleDecl: 571 case OverloadedDeclFromIdResolver: 572 case OverloadedDeclFromDeclContext: 573 case AmbiguousLookupStoresDecls: 574 return iterator(this, Last); 575 576 case OverloadedDeclSingleDecl: { 577 OverloadedFunctionDecl * Ovl = 578 reinterpret_cast<OverloadedFunctionDecl*>(First); 579 return iterator(this, 580 reinterpret_cast<uintptr_t>(&(*Ovl->function_end()))); 581 } 582 583 case AmbiguousLookupStoresBasePaths: 584 if (Last) 585 return iterator(this, 586 reinterpret_cast<uintptr_t>(getBasePaths()->found_decls_end())); 587 else 588 return iterator(this, reinterpret_cast<uintptr_t>( 589 getBasePaths()->front().Decls.second)); 590 } 591 592 // Required to suppress GCC warning. 593 return iterator(); 594} 595 596void Sema::LookupResult::Destroy() { 597 if (BasePaths *Paths = getBasePaths()) 598 delete Paths; 599 else if (getKind() == AmbiguousReference) 600 delete[] reinterpret_cast<NamedDecl **>(First); 601} 602 603static void 604CppNamespaceLookup(ASTContext &Context, DeclContext *NS, 605 DeclarationName Name, Sema::LookupNameKind NameKind, 606 unsigned IDNS, LookupResultsTy &Results, 607 UsingDirectivesTy *UDirs = 0) { 608 609 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!"); 610 611 // Perform qualified name lookup into the LookupCtx. 612 DeclContext::lookup_iterator I, E; 613 for (llvm::tie(I, E) = NS->lookup(Name); I != E; ++I) 614 if (Sema::isAcceptableLookupResult(*I, NameKind, IDNS)) { 615 Results.push_back(Sema::LookupResult::CreateLookupResult(Context, I, E)); 616 break; 617 } 618 619 if (UDirs) { 620 // For each UsingDirectiveDecl, which common ancestor is equal 621 // to NS, we preform qualified name lookup into namespace nominated by it. 622 UsingDirectivesTy::const_iterator UI, UEnd; 623 llvm::tie(UI, UEnd) = 624 std::equal_range(UDirs->begin(), UDirs->end(), NS, 625 UsingDirAncestorCompare()); 626 627 for (; UI != UEnd; ++UI) 628 CppNamespaceLookup(Context, (*UI)->getNominatedNamespace(), 629 Name, NameKind, IDNS, Results); 630 } 631} 632 633static bool isNamespaceOrTranslationUnitScope(Scope *S) { 634 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) 635 return Ctx->isFileContext(); 636 return false; 637} 638 639std::pair<bool, Sema::LookupResult> 640Sema::CppLookupName(Scope *S, DeclarationName Name, 641 LookupNameKind NameKind, bool RedeclarationOnly) { 642 assert(getLangOptions().CPlusPlus && 643 "Can perform only C++ lookup"); 644 unsigned IDNS 645 = getIdentifierNamespacesFromLookupNameKind(NameKind, /*CPlusPlus*/ true); 646 Scope *Initial = S; 647 DeclContext *OutOfLineCtx = 0; 648 IdentifierResolver::iterator 649 I = IdResolver.begin(Name), 650 IEnd = IdResolver.end(); 651 652 // First we lookup local scope. 653 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir] 654 // ...During unqualified name lookup (3.4.1), the names appear as if 655 // they were declared in the nearest enclosing namespace which contains 656 // both the using-directive and the nominated namespace. 657 // [Note: in this context, "contains" means "contains directly or 658 // indirectly". 659 // 660 // For example: 661 // namespace A { int i; } 662 // void foo() { 663 // int i; 664 // { 665 // using namespace A; 666 // ++i; // finds local 'i', A::i appears at global scope 667 // } 668 // } 669 // 670 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) { 671 // Check whether the IdResolver has anything in this scope. 672 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) { 673 if (isAcceptableLookupResult(*I, NameKind, IDNS)) { 674 // We found something. Look for anything else in our scope 675 // with this same name and in an acceptable identifier 676 // namespace, so that we can construct an overload set if we 677 // need to. 678 IdentifierResolver::iterator LastI = I; 679 for (++LastI; LastI != IEnd; ++LastI) { 680 if (!S->isDeclScope(DeclPtrTy::make(*LastI))) 681 break; 682 } 683 LookupResult Result = 684 LookupResult::CreateLookupResult(Context, I, LastI); 685 return std::make_pair(true, Result); 686 } 687 } 688 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) { 689 LookupResult R; 690 // Perform member lookup into struct. 691 // FIXME: In some cases, we know that every name that could be found by 692 // this qualified name lookup will also be on the identifier chain. For 693 // example, inside a class without any base classes, we never need to 694 // perform qualified lookup because all of the members are on top of the 695 // identifier chain. 696 if (isa<RecordDecl>(Ctx)) { 697 R = LookupQualifiedName(Ctx, Name, NameKind, RedeclarationOnly); 698 if (R) 699 return std::make_pair(true, R); 700 } 701 if (Ctx->getParent() != Ctx->getLexicalParent() 702 || isa<CXXMethodDecl>(Ctx)) { 703 // It is out of line defined C++ method or struct, we continue 704 // doing name lookup in parent context. Once we will find namespace 705 // or translation-unit we save it for possible checking 706 // using-directives later. 707 for (OutOfLineCtx = Ctx; OutOfLineCtx && !OutOfLineCtx->isFileContext(); 708 OutOfLineCtx = OutOfLineCtx->getParent()) { 709 R = LookupQualifiedName(OutOfLineCtx, Name, NameKind, RedeclarationOnly); 710 if (R) 711 return std::make_pair(true, R); 712 } 713 } 714 } 715 } 716 717 // Collect UsingDirectiveDecls in all scopes, and recursively all 718 // nominated namespaces by those using-directives. 719 // UsingDirectives are pushed to heap, in common ancestor pointer value order. 720 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we 721 // don't build it for each lookup! 722 UsingDirectivesTy UDirs; 723 for (Scope *SC = Initial; SC; SC = SC->getParent()) 724 if (SC->getFlags() & Scope::DeclScope) 725 AddScopeUsingDirectives(Context, SC, UDirs); 726 727 // Sort heapified UsingDirectiveDecls. 728 std::sort_heap(UDirs.begin(), UDirs.end(), UsingDirAncestorCompare()); 729 730 // Lookup namespace scope, and global scope. 731 // Unqualified name lookup in C++ requires looking into scopes 732 // that aren't strictly lexical, and therefore we walk through the 733 // context as well as walking through the scopes. 734 735 LookupResultsTy LookupResults; 736 assert((!OutOfLineCtx || OutOfLineCtx->isFileContext()) && 737 "We should have been looking only at file context here already."); 738 bool LookedInCtx = false; 739 LookupResult Result; 740 while (OutOfLineCtx && 741 OutOfLineCtx != S->getEntity() && 742 OutOfLineCtx->isNamespace()) { 743 LookedInCtx = true; 744 745 // Look into context considering using-directives. 746 CppNamespaceLookup(Context, OutOfLineCtx, Name, NameKind, IDNS, 747 LookupResults, &UDirs); 748 749 if ((Result = MergeLookupResults(Context, LookupResults)) || 750 (RedeclarationOnly && !OutOfLineCtx->isTransparentContext())) 751 return std::make_pair(true, Result); 752 753 OutOfLineCtx = OutOfLineCtx->getParent(); 754 } 755 756 for (; S; S = S->getParent()) { 757 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity()); 758 if (Ctx->isTransparentContext()) 759 continue; 760 761 assert(Ctx && Ctx->isFileContext() && 762 "We should have been looking only at file context here already."); 763 764 // Check whether the IdResolver has anything in this scope. 765 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) { 766 if (isAcceptableLookupResult(*I, NameKind, IDNS)) { 767 // We found something. Look for anything else in our scope 768 // with this same name and in an acceptable identifier 769 // namespace, so that we can construct an overload set if we 770 // need to. 771 IdentifierResolver::iterator LastI = I; 772 for (++LastI; LastI != IEnd; ++LastI) { 773 if (!S->isDeclScope(DeclPtrTy::make(*LastI))) 774 break; 775 } 776 777 // We store name lookup result, and continue trying to look into 778 // associated context, and maybe namespaces nominated by 779 // using-directives. 780 LookupResults.push_back( 781 LookupResult::CreateLookupResult(Context, I, LastI)); 782 break; 783 } 784 } 785 786 LookedInCtx = true; 787 // Look into context considering using-directives. 788 CppNamespaceLookup(Context, Ctx, Name, NameKind, IDNS, 789 LookupResults, &UDirs); 790 791 if ((Result = MergeLookupResults(Context, LookupResults)) || 792 (RedeclarationOnly && !Ctx->isTransparentContext())) 793 return std::make_pair(true, Result); 794 } 795 796 if (!(LookedInCtx || LookupResults.empty())) { 797 // We didn't Performed lookup in Scope entity, so we return 798 // result form IdentifierResolver. 799 assert((LookupResults.size() == 1) && "Wrong size!"); 800 return std::make_pair(true, LookupResults.front()); 801 } 802 return std::make_pair(false, LookupResult()); 803} 804 805/// @brief Perform unqualified name lookup starting from a given 806/// scope. 807/// 808/// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is 809/// used to find names within the current scope. For example, 'x' in 810/// @code 811/// int x; 812/// int f() { 813/// return x; // unqualified name look finds 'x' in the global scope 814/// } 815/// @endcode 816/// 817/// Different lookup criteria can find different names. For example, a 818/// particular scope can have both a struct and a function of the same 819/// name, and each can be found by certain lookup criteria. For more 820/// information about lookup criteria, see the documentation for the 821/// class LookupCriteria. 822/// 823/// @param S The scope from which unqualified name lookup will 824/// begin. If the lookup criteria permits, name lookup may also search 825/// in the parent scopes. 826/// 827/// @param Name The name of the entity that we are searching for. 828/// 829/// @param Loc If provided, the source location where we're performing 830/// name lookup. At present, this is only used to produce diagnostics when 831/// C library functions (like "malloc") are implicitly declared. 832/// 833/// @returns The result of name lookup, which includes zero or more 834/// declarations and possibly additional information used to diagnose 835/// ambiguities. 836Sema::LookupResult 837Sema::LookupName(Scope *S, DeclarationName Name, LookupNameKind NameKind, 838 bool RedeclarationOnly, bool AllowBuiltinCreation, 839 SourceLocation Loc) { 840 if (!Name) return LookupResult::CreateLookupResult(Context, 0); 841 842 if (!getLangOptions().CPlusPlus) { 843 // Unqualified name lookup in C/Objective-C is purely lexical, so 844 // search in the declarations attached to the name. 845 unsigned IDNS = 0; 846 switch (NameKind) { 847 case Sema::LookupOrdinaryName: 848 IDNS = Decl::IDNS_Ordinary; 849 break; 850 851 case Sema::LookupTagName: 852 IDNS = Decl::IDNS_Tag; 853 break; 854 855 case Sema::LookupMemberName: 856 IDNS = Decl::IDNS_Member; 857 break; 858 859 case Sema::LookupOperatorName: 860 case Sema::LookupNestedNameSpecifierName: 861 case Sema::LookupNamespaceName: 862 assert(false && "C does not perform these kinds of name lookup"); 863 break; 864 865 case Sema::LookupRedeclarationWithLinkage: 866 // Find the nearest non-transparent declaration scope. 867 while (!(S->getFlags() & Scope::DeclScope) || 868 (S->getEntity() && 869 static_cast<DeclContext *>(S->getEntity()) 870 ->isTransparentContext())) 871 S = S->getParent(); 872 IDNS = Decl::IDNS_Ordinary; 873 break; 874 875 case Sema::LookupObjCProtocolName: 876 IDNS = Decl::IDNS_ObjCProtocol; 877 break; 878 879 case Sema::LookupObjCImplementationName: 880 IDNS = Decl::IDNS_ObjCImplementation; 881 break; 882 883 case Sema::LookupObjCCategoryImplName: 884 IDNS = Decl::IDNS_ObjCCategoryImpl; 885 break; 886 } 887 888 // Scan up the scope chain looking for a decl that matches this 889 // identifier that is in the appropriate namespace. This search 890 // should not take long, as shadowing of names is uncommon, and 891 // deep shadowing is extremely uncommon. 892 bool LeftStartingScope = false; 893 894 for (IdentifierResolver::iterator I = IdResolver.begin(Name), 895 IEnd = IdResolver.end(); 896 I != IEnd; ++I) 897 if ((*I)->isInIdentifierNamespace(IDNS)) { 898 if (NameKind == LookupRedeclarationWithLinkage) { 899 // Determine whether this (or a previous) declaration is 900 // out-of-scope. 901 if (!LeftStartingScope && !S->isDeclScope(DeclPtrTy::make(*I))) 902 LeftStartingScope = true; 903 904 // If we found something outside of our starting scope that 905 // does not have linkage, skip it. 906 if (LeftStartingScope && !((*I)->hasLinkage())) 907 continue; 908 } 909 910 if ((*I)->getAttr<OverloadableAttr>()) { 911 // If this declaration has the "overloadable" attribute, we 912 // might have a set of overloaded functions. 913 914 // Figure out what scope the identifier is in. 915 while (!(S->getFlags() & Scope::DeclScope) || 916 !S->isDeclScope(DeclPtrTy::make(*I))) 917 S = S->getParent(); 918 919 // Find the last declaration in this scope (with the same 920 // name, naturally). 921 IdentifierResolver::iterator LastI = I; 922 for (++LastI; LastI != IEnd; ++LastI) { 923 if (!S->isDeclScope(DeclPtrTy::make(*LastI))) 924 break; 925 } 926 927 return LookupResult::CreateLookupResult(Context, I, LastI); 928 } 929 930 // We have a single lookup result. 931 return LookupResult::CreateLookupResult(Context, *I); 932 } 933 } else { 934 // Perform C++ unqualified name lookup. 935 std::pair<bool, LookupResult> MaybeResult = 936 CppLookupName(S, Name, NameKind, RedeclarationOnly); 937 if (MaybeResult.first) 938 return MaybeResult.second; 939 } 940 941 // If we didn't find a use of this identifier, and if the identifier 942 // corresponds to a compiler builtin, create the decl object for the builtin 943 // now, injecting it into translation unit scope, and return it. 944 if (NameKind == LookupOrdinaryName || 945 NameKind == LookupRedeclarationWithLinkage) { 946 IdentifierInfo *II = Name.getAsIdentifierInfo(); 947 if (II && AllowBuiltinCreation) { 948 // If this is a builtin on this (or all) targets, create the decl. 949 if (unsigned BuiltinID = II->getBuiltinID()) { 950 // In C++, we don't have any predefined library functions like 951 // 'malloc'. Instead, we'll just error. 952 if (getLangOptions().CPlusPlus && 953 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) 954 return LookupResult::CreateLookupResult(Context, 0); 955 956 return LookupResult::CreateLookupResult(Context, 957 LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, 958 S, RedeclarationOnly, Loc)); 959 } 960 } 961 } 962 return LookupResult::CreateLookupResult(Context, 0); 963} 964 965/// @brief Perform qualified name lookup into a given context. 966/// 967/// Qualified name lookup (C++ [basic.lookup.qual]) is used to find 968/// names when the context of those names is explicit specified, e.g., 969/// "std::vector" or "x->member". 970/// 971/// Different lookup criteria can find different names. For example, a 972/// particular scope can have both a struct and a function of the same 973/// name, and each can be found by certain lookup criteria. For more 974/// information about lookup criteria, see the documentation for the 975/// class LookupCriteria. 976/// 977/// @param LookupCtx The context in which qualified name lookup will 978/// search. If the lookup criteria permits, name lookup may also search 979/// in the parent contexts or (for C++ classes) base classes. 980/// 981/// @param Name The name of the entity that we are searching for. 982/// 983/// @param Criteria The criteria that this routine will use to 984/// determine which names are visible and which names will be 985/// found. Note that name lookup will find a name that is visible by 986/// the given criteria, but the entity itself may not be semantically 987/// correct or even the kind of entity expected based on the 988/// lookup. For example, searching for a nested-name-specifier name 989/// might result in an EnumDecl, which is visible but is not permitted 990/// as a nested-name-specifier in C++03. 991/// 992/// @returns The result of name lookup, which includes zero or more 993/// declarations and possibly additional information used to diagnose 994/// ambiguities. 995Sema::LookupResult 996Sema::LookupQualifiedName(DeclContext *LookupCtx, DeclarationName Name, 997 LookupNameKind NameKind, bool RedeclarationOnly) { 998 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context"); 999 1000 if (!Name) return LookupResult::CreateLookupResult(Context, 0); 1001 1002 // If we're performing qualified name lookup (e.g., lookup into a 1003 // struct), find fields as part of ordinary name lookup. 1004 unsigned IDNS 1005 = getIdentifierNamespacesFromLookupNameKind(NameKind, 1006 getLangOptions().CPlusPlus); 1007 if (NameKind == LookupOrdinaryName) 1008 IDNS |= Decl::IDNS_Member; 1009 1010 // Perform qualified name lookup into the LookupCtx. 1011 DeclContext::lookup_iterator I, E; 1012 for (llvm::tie(I, E) = LookupCtx->lookup(Name); I != E; ++I) 1013 if (isAcceptableLookupResult(*I, NameKind, IDNS)) 1014 return LookupResult::CreateLookupResult(Context, I, E); 1015 1016 // If this isn't a C++ class or we aren't allowed to look into base 1017 // classes, we're done. 1018 if (RedeclarationOnly || !isa<CXXRecordDecl>(LookupCtx)) 1019 return LookupResult::CreateLookupResult(Context, 0); 1020 1021 // Perform lookup into our base classes. 1022 BasePaths Paths; 1023 Paths.setOrigin(Context.getTypeDeclType(cast<RecordDecl>(LookupCtx))); 1024 1025 // Look for this member in our base classes 1026 if (!LookupInBases(cast<CXXRecordDecl>(LookupCtx), 1027 MemberLookupCriteria(Name, NameKind, IDNS), Paths)) 1028 return LookupResult::CreateLookupResult(Context, 0); 1029 1030 // C++ [class.member.lookup]p2: 1031 // [...] If the resulting set of declarations are not all from 1032 // sub-objects of the same type, or the set has a nonstatic member 1033 // and includes members from distinct sub-objects, there is an 1034 // ambiguity and the program is ill-formed. Otherwise that set is 1035 // the result of the lookup. 1036 // FIXME: support using declarations! 1037 QualType SubobjectType; 1038 int SubobjectNumber = 0; 1039 for (BasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); 1040 Path != PathEnd; ++Path) { 1041 const BasePathElement &PathElement = Path->back(); 1042 1043 // Determine whether we're looking at a distinct sub-object or not. 1044 if (SubobjectType.isNull()) { 1045 // This is the first subobject we've looked at. Record it's type. 1046 SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); 1047 SubobjectNumber = PathElement.SubobjectNumber; 1048 } else if (SubobjectType 1049 != Context.getCanonicalType(PathElement.Base->getType())) { 1050 // We found members of the given name in two subobjects of 1051 // different types. This lookup is ambiguous. 1052 BasePaths *PathsOnHeap = new BasePaths; 1053 PathsOnHeap->swap(Paths); 1054 return LookupResult::CreateLookupResult(Context, PathsOnHeap, true); 1055 } else if (SubobjectNumber != PathElement.SubobjectNumber) { 1056 // We have a different subobject of the same type. 1057 1058 // C++ [class.member.lookup]p5: 1059 // A static member, a nested type or an enumerator defined in 1060 // a base class T can unambiguously be found even if an object 1061 // has more than one base class subobject of type T. 1062 Decl *FirstDecl = *Path->Decls.first; 1063 if (isa<VarDecl>(FirstDecl) || 1064 isa<TypeDecl>(FirstDecl) || 1065 isa<EnumConstantDecl>(FirstDecl)) 1066 continue; 1067 1068 if (isa<CXXMethodDecl>(FirstDecl)) { 1069 // Determine whether all of the methods are static. 1070 bool AllMethodsAreStatic = true; 1071 for (DeclContext::lookup_iterator Func = Path->Decls.first; 1072 Func != Path->Decls.second; ++Func) { 1073 if (!isa<CXXMethodDecl>(*Func)) { 1074 assert(isa<TagDecl>(*Func) && "Non-function must be a tag decl"); 1075 break; 1076 } 1077 1078 if (!cast<CXXMethodDecl>(*Func)->isStatic()) { 1079 AllMethodsAreStatic = false; 1080 break; 1081 } 1082 } 1083 1084 if (AllMethodsAreStatic) 1085 continue; 1086 } 1087 1088 // We have found a nonstatic member name in multiple, distinct 1089 // subobjects. Name lookup is ambiguous. 1090 BasePaths *PathsOnHeap = new BasePaths; 1091 PathsOnHeap->swap(Paths); 1092 return LookupResult::CreateLookupResult(Context, PathsOnHeap, false); 1093 } 1094 } 1095 1096 // Lookup in a base class succeeded; return these results. 1097 1098 // If we found a function declaration, return an overload set. 1099 if ((*Paths.front().Decls.first)->isFunctionOrFunctionTemplate()) 1100 return LookupResult::CreateLookupResult(Context, 1101 Paths.front().Decls.first, Paths.front().Decls.second); 1102 1103 // We found a non-function declaration; return a single declaration. 1104 return LookupResult::CreateLookupResult(Context, *Paths.front().Decls.first); 1105} 1106 1107/// @brief Performs name lookup for a name that was parsed in the 1108/// source code, and may contain a C++ scope specifier. 1109/// 1110/// This routine is a convenience routine meant to be called from 1111/// contexts that receive a name and an optional C++ scope specifier 1112/// (e.g., "N::M::x"). It will then perform either qualified or 1113/// unqualified name lookup (with LookupQualifiedName or LookupName, 1114/// respectively) on the given name and return those results. 1115/// 1116/// @param S The scope from which unqualified name lookup will 1117/// begin. 1118/// 1119/// @param SS An optional C++ scope-specifier, e.g., "::N::M". 1120/// 1121/// @param Name The name of the entity that name lookup will 1122/// search for. 1123/// 1124/// @param Loc If provided, the source location where we're performing 1125/// name lookup. At present, this is only used to produce diagnostics when 1126/// C library functions (like "malloc") are implicitly declared. 1127/// 1128/// @param EnteringContext Indicates whether we are going to enter the 1129/// context of the scope-specifier SS (if present). 1130/// 1131/// @returns The result of qualified or unqualified name lookup. 1132Sema::LookupResult 1133Sema::LookupParsedName(Scope *S, const CXXScopeSpec *SS, 1134 DeclarationName Name, LookupNameKind NameKind, 1135 bool RedeclarationOnly, bool AllowBuiltinCreation, 1136 SourceLocation Loc, 1137 bool EnteringContext) { 1138 if (SS && SS->isInvalid()) { 1139 // When the scope specifier is invalid, don't even look for 1140 // anything. 1141 return LookupResult::CreateLookupResult(Context, 0); 1142 } 1143 1144 if (SS && SS->isSet()) { 1145 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { 1146 // We have resolved the scope specifier to a particular declaration 1147 // contex, and will perform name lookup in that context. 1148 1149 if (DC->isDependentContext()) { 1150 // If this is a dependent context, then we are looking for a member of 1151 // the current instantiation. This is a narrow search that looks into 1152 // just the described declaration context (C++0x [temp.dep.type]). 1153 unsigned IDNS = getIdentifierNamespacesFromLookupNameKind(NameKind, 1154 true); 1155 DeclContext::lookup_iterator I, E; 1156 for (llvm::tie(I, E) = DC->lookup(Name); I != E; ++I) 1157 if (isAcceptableLookupResult(*I, NameKind, IDNS)) 1158 return LookupResult::CreateLookupResult(Context, I, E); 1159 } 1160 1161 // Qualified name lookup into the named declaration context. 1162 // The declaration context must be complete. 1163 if (RequireCompleteDeclContext(*SS)) 1164 return LookupResult::CreateLookupResult(Context, 0); 1165 1166 return LookupQualifiedName(DC, Name, NameKind, RedeclarationOnly); 1167 } 1168 1169 // We could not resolve the scope specified to a specific declaration 1170 // context, which means that SS refers to an unknown specialization. 1171 // Name lookup can't find anything in this case. 1172 return LookupResult::CreateLookupResult(Context, 0); 1173 } 1174 1175 // Perform unqualified name lookup starting in the given scope. 1176 return LookupName(S, Name, NameKind, RedeclarationOnly, AllowBuiltinCreation, 1177 Loc); 1178} 1179 1180 1181/// @brief Produce a diagnostic describing the ambiguity that resulted 1182/// from name lookup. 1183/// 1184/// @param Result The ambiguous name lookup result. 1185/// 1186/// @param Name The name of the entity that name lookup was 1187/// searching for. 1188/// 1189/// @param NameLoc The location of the name within the source code. 1190/// 1191/// @param LookupRange A source range that provides more 1192/// source-location information concerning the lookup itself. For 1193/// example, this range might highlight a nested-name-specifier that 1194/// precedes the name. 1195/// 1196/// @returns true 1197bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result, DeclarationName Name, 1198 SourceLocation NameLoc, 1199 SourceRange LookupRange) { 1200 assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); 1201 1202 if (BasePaths *Paths = Result.getBasePaths()) { 1203 if (Result.getKind() == LookupResult::AmbiguousBaseSubobjects) { 1204 QualType SubobjectType = Paths->front().back().Base->getType(); 1205 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) 1206 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) 1207 << LookupRange; 1208 1209 DeclContext::lookup_iterator Found = Paths->front().Decls.first; 1210 while (isa<CXXMethodDecl>(*Found) && 1211 cast<CXXMethodDecl>(*Found)->isStatic()) 1212 ++Found; 1213 1214 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); 1215 1216 Result.Destroy(); 1217 return true; 1218 } 1219 1220 assert(Result.getKind() == LookupResult::AmbiguousBaseSubobjectTypes && 1221 "Unhandled form of name lookup ambiguity"); 1222 1223 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) 1224 << Name << LookupRange; 1225 1226 std::set<Decl *> DeclsPrinted; 1227 for (BasePaths::paths_iterator Path = Paths->begin(), PathEnd = Paths->end(); 1228 Path != PathEnd; ++Path) { 1229 Decl *D = *Path->Decls.first; 1230 if (DeclsPrinted.insert(D).second) 1231 Diag(D->getLocation(), diag::note_ambiguous_member_found); 1232 } 1233 1234 Result.Destroy(); 1235 return true; 1236 } else if (Result.getKind() == LookupResult::AmbiguousReference) { 1237 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; 1238 1239 NamedDecl **DI = reinterpret_cast<NamedDecl **>(Result.First), 1240 **DEnd = reinterpret_cast<NamedDecl **>(Result.Last); 1241 1242 for (; DI != DEnd; ++DI) 1243 Diag((*DI)->getLocation(), diag::note_ambiguous_candidate) << *DI; 1244 1245 Result.Destroy(); 1246 return true; 1247 } 1248 1249 assert(false && "Unhandled form of name lookup ambiguity"); 1250 1251 // We can't reach here. 1252 return true; 1253} 1254 1255static void 1256addAssociatedClassesAndNamespaces(QualType T, 1257 ASTContext &Context, 1258 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1259 Sema::AssociatedClassSet &AssociatedClasses); 1260 1261static void CollectNamespace(Sema::AssociatedNamespaceSet &Namespaces, 1262 DeclContext *Ctx) { 1263 if (Ctx->isFileContext()) 1264 Namespaces.insert(Ctx); 1265} 1266 1267// \brief Add the associated classes and namespaces for argument-dependent 1268// lookup that involves a template argument (C++ [basic.lookup.koenig]p2). 1269static void 1270addAssociatedClassesAndNamespaces(const TemplateArgument &Arg, 1271 ASTContext &Context, 1272 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1273 Sema::AssociatedClassSet &AssociatedClasses) { 1274 // C++ [basic.lookup.koenig]p2, last bullet: 1275 // -- [...] ; 1276 switch (Arg.getKind()) { 1277 case TemplateArgument::Null: 1278 break; 1279 1280 case TemplateArgument::Type: 1281 // [...] the namespaces and classes associated with the types of the 1282 // template arguments provided for template type parameters (excluding 1283 // template template parameters) 1284 addAssociatedClassesAndNamespaces(Arg.getAsType(), Context, 1285 AssociatedNamespaces, 1286 AssociatedClasses); 1287 break; 1288 1289 case TemplateArgument::Declaration: 1290 // [...] the namespaces in which any template template arguments are 1291 // defined; and the classes in which any member templates used as 1292 // template template arguments are defined. 1293 if (ClassTemplateDecl *ClassTemplate 1294 = dyn_cast<ClassTemplateDecl>(Arg.getAsDecl())) { 1295 DeclContext *Ctx = ClassTemplate->getDeclContext(); 1296 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1297 AssociatedClasses.insert(EnclosingClass); 1298 // Add the associated namespace for this class. 1299 while (Ctx->isRecord()) 1300 Ctx = Ctx->getParent(); 1301 CollectNamespace(AssociatedNamespaces, Ctx); 1302 } 1303 break; 1304 1305 case TemplateArgument::Integral: 1306 case TemplateArgument::Expression: 1307 // [Note: non-type template arguments do not contribute to the set of 1308 // associated namespaces. ] 1309 break; 1310 1311 case TemplateArgument::Pack: 1312 for (TemplateArgument::pack_iterator P = Arg.pack_begin(), 1313 PEnd = Arg.pack_end(); 1314 P != PEnd; ++P) 1315 addAssociatedClassesAndNamespaces(*P, Context, 1316 AssociatedNamespaces, 1317 AssociatedClasses); 1318 break; 1319 } 1320} 1321 1322// \brief Add the associated classes and namespaces for 1323// argument-dependent lookup with an argument of class type 1324// (C++ [basic.lookup.koenig]p2). 1325static void 1326addAssociatedClassesAndNamespaces(CXXRecordDecl *Class, 1327 ASTContext &Context, 1328 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1329 Sema::AssociatedClassSet &AssociatedClasses) { 1330 // C++ [basic.lookup.koenig]p2: 1331 // [...] 1332 // -- If T is a class type (including unions), its associated 1333 // classes are: the class itself; the class of which it is a 1334 // member, if any; and its direct and indirect base 1335 // classes. Its associated namespaces are the namespaces in 1336 // which its associated classes are defined. 1337 1338 // Add the class of which it is a member, if any. 1339 DeclContext *Ctx = Class->getDeclContext(); 1340 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1341 AssociatedClasses.insert(EnclosingClass); 1342 // Add the associated namespace for this class. 1343 while (Ctx->isRecord()) 1344 Ctx = Ctx->getParent(); 1345 CollectNamespace(AssociatedNamespaces, Ctx); 1346 1347 // Add the class itself. If we've already seen this class, we don't 1348 // need to visit base classes. 1349 if (!AssociatedClasses.insert(Class)) 1350 return; 1351 1352 // -- If T is a template-id, its associated namespaces and classes are 1353 // the namespace in which the template is defined; for member 1354 // templates, the member template’s class; the namespaces and classes 1355 // associated with the types of the template arguments provided for 1356 // template type parameters (excluding template template parameters); the 1357 // namespaces in which any template template arguments are defined; and 1358 // the classes in which any member templates used as template template 1359 // arguments are defined. [Note: non-type template arguments do not 1360 // contribute to the set of associated namespaces. ] 1361 if (ClassTemplateSpecializationDecl *Spec 1362 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) { 1363 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); 1364 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1365 AssociatedClasses.insert(EnclosingClass); 1366 // Add the associated namespace for this class. 1367 while (Ctx->isRecord()) 1368 Ctx = Ctx->getParent(); 1369 CollectNamespace(AssociatedNamespaces, Ctx); 1370 1371 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); 1372 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 1373 addAssociatedClassesAndNamespaces(TemplateArgs[I], Context, 1374 AssociatedNamespaces, 1375 AssociatedClasses); 1376 } 1377 1378 // Add direct and indirect base classes along with their associated 1379 // namespaces. 1380 llvm::SmallVector<CXXRecordDecl *, 32> Bases; 1381 Bases.push_back(Class); 1382 while (!Bases.empty()) { 1383 // Pop this class off the stack. 1384 Class = Bases.back(); 1385 Bases.pop_back(); 1386 1387 // Visit the base classes. 1388 for (CXXRecordDecl::base_class_iterator Base = Class->bases_begin(), 1389 BaseEnd = Class->bases_end(); 1390 Base != BaseEnd; ++Base) { 1391 const RecordType *BaseType = Base->getType()->getAs<RecordType>(); 1392 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 1393 if (AssociatedClasses.insert(BaseDecl)) { 1394 // Find the associated namespace for this base class. 1395 DeclContext *BaseCtx = BaseDecl->getDeclContext(); 1396 while (BaseCtx->isRecord()) 1397 BaseCtx = BaseCtx->getParent(); 1398 CollectNamespace(AssociatedNamespaces, BaseCtx); 1399 1400 // Make sure we visit the bases of this base class. 1401 if (BaseDecl->bases_begin() != BaseDecl->bases_end()) 1402 Bases.push_back(BaseDecl); 1403 } 1404 } 1405 } 1406} 1407 1408// \brief Add the associated classes and namespaces for 1409// argument-dependent lookup with an argument of type T 1410// (C++ [basic.lookup.koenig]p2). 1411static void 1412addAssociatedClassesAndNamespaces(QualType T, 1413 ASTContext &Context, 1414 Sema::AssociatedNamespaceSet &AssociatedNamespaces, 1415 Sema::AssociatedClassSet &AssociatedClasses) { 1416 // C++ [basic.lookup.koenig]p2: 1417 // 1418 // For each argument type T in the function call, there is a set 1419 // of zero or more associated namespaces and a set of zero or more 1420 // associated classes to be considered. The sets of namespaces and 1421 // classes is determined entirely by the types of the function 1422 // arguments (and the namespace of any template template 1423 // argument). Typedef names and using-declarations used to specify 1424 // the types do not contribute to this set. The sets of namespaces 1425 // and classes are determined in the following way: 1426 T = Context.getCanonicalType(T).getUnqualifiedType(); 1427 1428 // -- If T is a pointer to U or an array of U, its associated 1429 // namespaces and classes are those associated with U. 1430 // 1431 // We handle this by unwrapping pointer and array types immediately, 1432 // to avoid unnecessary recursion. 1433 while (true) { 1434 if (const PointerType *Ptr = T->getAs<PointerType>()) 1435 T = Ptr->getPointeeType(); 1436 else if (const ArrayType *Ptr = Context.getAsArrayType(T)) 1437 T = Ptr->getElementType(); 1438 else 1439 break; 1440 } 1441 1442 // -- If T is a fundamental type, its associated sets of 1443 // namespaces and classes are both empty. 1444 if (T->getAsBuiltinType()) 1445 return; 1446 1447 // -- If T is a class type (including unions), its associated 1448 // classes are: the class itself; the class of which it is a 1449 // member, if any; and its direct and indirect base 1450 // classes. Its associated namespaces are the namespaces in 1451 // which its associated classes are defined. 1452 if (const RecordType *ClassType = T->getAs<RecordType>()) 1453 if (CXXRecordDecl *ClassDecl 1454 = dyn_cast<CXXRecordDecl>(ClassType->getDecl())) { 1455 addAssociatedClassesAndNamespaces(ClassDecl, Context, 1456 AssociatedNamespaces, 1457 AssociatedClasses); 1458 return; 1459 } 1460 1461 // -- If T is an enumeration type, its associated namespace is 1462 // the namespace in which it is defined. If it is class 1463 // member, its associated class is the member’s class; else 1464 // it has no associated class. 1465 if (const EnumType *EnumT = T->getAsEnumType()) { 1466 EnumDecl *Enum = EnumT->getDecl(); 1467 1468 DeclContext *Ctx = Enum->getDeclContext(); 1469 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx)) 1470 AssociatedClasses.insert(EnclosingClass); 1471 1472 // Add the associated namespace for this class. 1473 while (Ctx->isRecord()) 1474 Ctx = Ctx->getParent(); 1475 CollectNamespace(AssociatedNamespaces, Ctx); 1476 1477 return; 1478 } 1479 1480 // -- If T is a function type, its associated namespaces and 1481 // classes are those associated with the function parameter 1482 // types and those associated with the return type. 1483 if (const FunctionType *FunctionType = T->getAsFunctionType()) { 1484 // Return type 1485 addAssociatedClassesAndNamespaces(FunctionType->getResultType(), 1486 Context, 1487 AssociatedNamespaces, AssociatedClasses); 1488 1489 const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FunctionType); 1490 if (!Proto) 1491 return; 1492 1493 // Argument types 1494 for (FunctionProtoType::arg_type_iterator Arg = Proto->arg_type_begin(), 1495 ArgEnd = Proto->arg_type_end(); 1496 Arg != ArgEnd; ++Arg) 1497 addAssociatedClassesAndNamespaces(*Arg, Context, 1498 AssociatedNamespaces, AssociatedClasses); 1499 1500 return; 1501 } 1502 1503 // -- If T is a pointer to a member function of a class X, its 1504 // associated namespaces and classes are those associated 1505 // with the function parameter types and return type, 1506 // together with those associated with X. 1507 // 1508 // -- If T is a pointer to a data member of class X, its 1509 // associated namespaces and classes are those associated 1510 // with the member type together with those associated with 1511 // X. 1512 if (const MemberPointerType *MemberPtr = T->getAs<MemberPointerType>()) { 1513 // Handle the type that the pointer to member points to. 1514 addAssociatedClassesAndNamespaces(MemberPtr->getPointeeType(), 1515 Context, 1516 AssociatedNamespaces, 1517 AssociatedClasses); 1518 1519 // Handle the class type into which this points. 1520 if (const RecordType *Class = MemberPtr->getClass()->getAs<RecordType>()) 1521 addAssociatedClassesAndNamespaces(cast<CXXRecordDecl>(Class->getDecl()), 1522 Context, 1523 AssociatedNamespaces, 1524 AssociatedClasses); 1525 1526 return; 1527 } 1528 1529 // FIXME: What about block pointers? 1530 // FIXME: What about Objective-C message sends? 1531} 1532 1533/// \brief Find the associated classes and namespaces for 1534/// argument-dependent lookup for a call with the given set of 1535/// arguments. 1536/// 1537/// This routine computes the sets of associated classes and associated 1538/// namespaces searched by argument-dependent lookup 1539/// (C++ [basic.lookup.argdep]) for a given set of arguments. 1540void 1541Sema::FindAssociatedClassesAndNamespaces(Expr **Args, unsigned NumArgs, 1542 AssociatedNamespaceSet &AssociatedNamespaces, 1543 AssociatedClassSet &AssociatedClasses) { 1544 AssociatedNamespaces.clear(); 1545 AssociatedClasses.clear(); 1546 1547 // C++ [basic.lookup.koenig]p2: 1548 // For each argument type T in the function call, there is a set 1549 // of zero or more associated namespaces and a set of zero or more 1550 // associated classes to be considered. The sets of namespaces and 1551 // classes is determined entirely by the types of the function 1552 // arguments (and the namespace of any template template 1553 // argument). 1554 for (unsigned ArgIdx = 0; ArgIdx != NumArgs; ++ArgIdx) { 1555 Expr *Arg = Args[ArgIdx]; 1556 1557 if (Arg->getType() != Context.OverloadTy) { 1558 addAssociatedClassesAndNamespaces(Arg->getType(), Context, 1559 AssociatedNamespaces, 1560 AssociatedClasses); 1561 continue; 1562 } 1563 1564 // [...] In addition, if the argument is the name or address of a 1565 // set of overloaded functions and/or function templates, its 1566 // associated classes and namespaces are the union of those 1567 // associated with each of the members of the set: the namespace 1568 // in which the function or function template is defined and the 1569 // classes and namespaces associated with its (non-dependent) 1570 // parameter types and return type. 1571 DeclRefExpr *DRE = 0; 1572 TemplateIdRefExpr *TIRE = 0; 1573 Arg = Arg->IgnoreParens(); 1574 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg)) { 1575 if (unaryOp->getOpcode() == UnaryOperator::AddrOf) { 1576 DRE = dyn_cast<DeclRefExpr>(unaryOp->getSubExpr()); 1577 TIRE = dyn_cast<TemplateIdRefExpr>(unaryOp->getSubExpr()); 1578 } 1579 } else { 1580 DRE = dyn_cast<DeclRefExpr>(Arg); 1581 TIRE = dyn_cast<TemplateIdRefExpr>(Arg); 1582 } 1583 1584 OverloadedFunctionDecl *Ovl = 0; 1585 if (DRE) 1586 Ovl = dyn_cast<OverloadedFunctionDecl>(DRE->getDecl()); 1587 else if (TIRE) 1588 Ovl = TIRE->getTemplateName().getAsOverloadedFunctionDecl(); 1589 if (!Ovl) 1590 continue; 1591 1592 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 1593 FuncEnd = Ovl->function_end(); 1594 Func != FuncEnd; ++Func) { 1595 FunctionDecl *FDecl = dyn_cast<FunctionDecl>(*Func); 1596 if (!FDecl) 1597 FDecl = cast<FunctionTemplateDecl>(*Func)->getTemplatedDecl(); 1598 1599 // Add the namespace in which this function was defined. Note 1600 // that, if this is a member function, we do *not* consider the 1601 // enclosing namespace of its class. 1602 DeclContext *Ctx = FDecl->getDeclContext(); 1603 CollectNamespace(AssociatedNamespaces, Ctx); 1604 1605 // Add the classes and namespaces associated with the parameter 1606 // types and return type of this function. 1607 addAssociatedClassesAndNamespaces(FDecl->getType(), Context, 1608 AssociatedNamespaces, 1609 AssociatedClasses); 1610 } 1611 } 1612} 1613 1614/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is 1615/// an acceptable non-member overloaded operator for a call whose 1616/// arguments have types T1 (and, if non-empty, T2). This routine 1617/// implements the check in C++ [over.match.oper]p3b2 concerning 1618/// enumeration types. 1619static bool 1620IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn, 1621 QualType T1, QualType T2, 1622 ASTContext &Context) { 1623 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType())) 1624 return true; 1625 1626 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType())) 1627 return true; 1628 1629 const FunctionProtoType *Proto = Fn->getType()->getAsFunctionProtoType(); 1630 if (Proto->getNumArgs() < 1) 1631 return false; 1632 1633 if (T1->isEnumeralType()) { 1634 QualType ArgType = Proto->getArgType(0).getNonReferenceType(); 1635 if (Context.getCanonicalType(T1).getUnqualifiedType() 1636 == Context.getCanonicalType(ArgType).getUnqualifiedType()) 1637 return true; 1638 } 1639 1640 if (Proto->getNumArgs() < 2) 1641 return false; 1642 1643 if (!T2.isNull() && T2->isEnumeralType()) { 1644 QualType ArgType = Proto->getArgType(1).getNonReferenceType(); 1645 if (Context.getCanonicalType(T2).getUnqualifiedType() 1646 == Context.getCanonicalType(ArgType).getUnqualifiedType()) 1647 return true; 1648 } 1649 1650 return false; 1651} 1652 1653/// \brief Find the protocol with the given name, if any. 1654ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II) { 1655 Decl *D = LookupName(TUScope, II, LookupObjCProtocolName).getAsDecl(); 1656 return cast_or_null<ObjCProtocolDecl>(D); 1657} 1658 1659/// \brief Find the Objective-C category implementation with the given 1660/// name, if any. 1661ObjCCategoryImplDecl *Sema::LookupObjCCategoryImpl(IdentifierInfo *II) { 1662 Decl *D = LookupName(TUScope, II, LookupObjCCategoryImplName).getAsDecl(); 1663 return cast_or_null<ObjCCategoryImplDecl>(D); 1664} 1665 1666// Attempts to find a declaration in the given declaration context 1667// with exactly the given type. Returns null if no such declaration 1668// was found. 1669Decl *Sema::LookupQualifiedNameWithType(DeclContext *DC, 1670 DeclarationName Name, 1671 QualType T) { 1672 LookupResult result = 1673 LookupQualifiedName(DC, Name, LookupOrdinaryName, true); 1674 1675 CanQualType CQT = Context.getCanonicalType(T); 1676 1677 for (LookupResult::iterator ir = result.begin(), ie = result.end(); 1678 ir != ie; ++ir) 1679 if (FunctionDecl *CurFD = dyn_cast<FunctionDecl>(*ir)) 1680 if (Context.getCanonicalType(CurFD->getType()) == CQT) 1681 return CurFD; 1682 1683 return NULL; 1684} 1685 1686void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, 1687 QualType T1, QualType T2, 1688 FunctionSet &Functions) { 1689 // C++ [over.match.oper]p3: 1690 // -- The set of non-member candidates is the result of the 1691 // unqualified lookup of operator@ in the context of the 1692 // expression according to the usual rules for name lookup in 1693 // unqualified function calls (3.4.2) except that all member 1694 // functions are ignored. However, if no operand has a class 1695 // type, only those non-member functions in the lookup set 1696 // that have a first parameter of type T1 or "reference to 1697 // (possibly cv-qualified) T1", when T1 is an enumeration 1698 // type, or (if there is a right operand) a second parameter 1699 // of type T2 or "reference to (possibly cv-qualified) T2", 1700 // when T2 is an enumeration type, are candidate functions. 1701 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 1702 LookupResult Operators = LookupName(S, OpName, LookupOperatorName); 1703 1704 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); 1705 1706 if (!Operators) 1707 return; 1708 1709 for (LookupResult::iterator Op = Operators.begin(), OpEnd = Operators.end(); 1710 Op != OpEnd; ++Op) { 1711 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Op)) { 1712 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context)) 1713 Functions.insert(FD); // FIXME: canonical FD 1714 } else if (FunctionTemplateDecl *FunTmpl 1715 = dyn_cast<FunctionTemplateDecl>(*Op)) { 1716 // FIXME: friend operators? 1717 // FIXME: do we need to check IsAcceptableNonMemberOperatorCandidate, 1718 // later? 1719 if (!FunTmpl->getDeclContext()->isRecord()) 1720 Functions.insert(FunTmpl); 1721 } 1722 } 1723} 1724 1725static void CollectFunctionDecl(Sema::FunctionSet &Functions, 1726 Decl *D) { 1727 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(D)) 1728 Functions.insert(Func); 1729 else if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D)) 1730 Functions.insert(FunTmpl); 1731} 1732 1733void Sema::ArgumentDependentLookup(DeclarationName Name, 1734 Expr **Args, unsigned NumArgs, 1735 FunctionSet &Functions) { 1736 // Find all of the associated namespaces and classes based on the 1737 // arguments we have. 1738 AssociatedNamespaceSet AssociatedNamespaces; 1739 AssociatedClassSet AssociatedClasses; 1740 FindAssociatedClassesAndNamespaces(Args, NumArgs, 1741 AssociatedNamespaces, 1742 AssociatedClasses); 1743 1744 // C++ [basic.lookup.argdep]p3: 1745 // Let X be the lookup set produced by unqualified lookup (3.4.1) 1746 // and let Y be the lookup set produced by argument dependent 1747 // lookup (defined as follows). If X contains [...] then Y is 1748 // empty. Otherwise Y is the set of declarations found in the 1749 // namespaces associated with the argument types as described 1750 // below. The set of declarations found by the lookup of the name 1751 // is the union of X and Y. 1752 // 1753 // Here, we compute Y and add its members to the overloaded 1754 // candidate set. 1755 for (AssociatedNamespaceSet::iterator NS = AssociatedNamespaces.begin(), 1756 NSEnd = AssociatedNamespaces.end(); 1757 NS != NSEnd; ++NS) { 1758 // When considering an associated namespace, the lookup is the 1759 // same as the lookup performed when the associated namespace is 1760 // used as a qualifier (3.4.3.2) except that: 1761 // 1762 // -- Any using-directives in the associated namespace are 1763 // ignored. 1764 // 1765 // -- Any namespace-scope friend functions declared in 1766 // associated classes are visible within their respective 1767 // namespaces even if they are not visible during an ordinary 1768 // lookup (11.4). 1769 DeclContext::lookup_iterator I, E; 1770 for (llvm::tie(I, E) = (*NS)->lookup(Name); I != E; ++I) { 1771 Decl *D = *I; 1772 // Only count friend declarations which were declared in 1773 // associated classes. 1774 if (D->isInIdentifierNamespace(Decl::IDNS_Friend)) { 1775 DeclContext *LexDC = D->getLexicalDeclContext(); 1776 if (!AssociatedClasses.count(cast<CXXRecordDecl>(LexDC))) 1777 continue; 1778 } 1779 1780 CollectFunctionDecl(Functions, D); 1781 } 1782 } 1783} 1784