SemaCXXScopeSpec.cpp revision 223017
1//===--- SemaCXXScopeSpec.cpp - Semantic Analysis for C++ scope specifiers-===// 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 C++ semantic analysis for scope specifiers. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Sema/SemaInternal.h" 15#include "clang/Sema/Lookup.h" 16#include "clang/AST/ASTContext.h" 17#include "clang/AST/DeclTemplate.h" 18#include "clang/AST/ExprCXX.h" 19#include "clang/AST/NestedNameSpecifier.h" 20#include "clang/Basic/PartialDiagnostic.h" 21#include "clang/Sema/DeclSpec.h" 22#include "TypeLocBuilder.h" 23#include "llvm/ADT/STLExtras.h" 24#include "llvm/Support/raw_ostream.h" 25using namespace clang; 26 27/// \brief Find the current instantiation that associated with the given type. 28static CXXRecordDecl *getCurrentInstantiationOf(QualType T, 29 DeclContext *CurContext) { 30 if (T.isNull()) 31 return 0; 32 33 const Type *Ty = T->getCanonicalTypeInternal().getTypePtr(); 34 if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) { 35 CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordTy->getDecl()); 36 if (!T->isDependentType()) 37 return Record; 38 39 // This may be a member of a class template or class template partial 40 // specialization. If it's part of the current semantic context, then it's 41 // an injected-class-name; 42 for (; !CurContext->isFileContext(); CurContext = CurContext->getParent()) 43 if (CurContext->Equals(Record)) 44 return Record; 45 46 return 0; 47 } else if (isa<InjectedClassNameType>(Ty)) 48 return cast<InjectedClassNameType>(Ty)->getDecl(); 49 else 50 return 0; 51} 52 53/// \brief Compute the DeclContext that is associated with the given type. 54/// 55/// \param T the type for which we are attempting to find a DeclContext. 56/// 57/// \returns the declaration context represented by the type T, 58/// or NULL if the declaration context cannot be computed (e.g., because it is 59/// dependent and not the current instantiation). 60DeclContext *Sema::computeDeclContext(QualType T) { 61 if (!T->isDependentType()) 62 if (const TagType *Tag = T->getAs<TagType>()) 63 return Tag->getDecl(); 64 65 return ::getCurrentInstantiationOf(T, CurContext); 66} 67 68/// \brief Compute the DeclContext that is associated with the given 69/// scope specifier. 70/// 71/// \param SS the C++ scope specifier as it appears in the source 72/// 73/// \param EnteringContext when true, we will be entering the context of 74/// this scope specifier, so we can retrieve the declaration context of a 75/// class template or class template partial specialization even if it is 76/// not the current instantiation. 77/// 78/// \returns the declaration context represented by the scope specifier @p SS, 79/// or NULL if the declaration context cannot be computed (e.g., because it is 80/// dependent and not the current instantiation). 81DeclContext *Sema::computeDeclContext(const CXXScopeSpec &SS, 82 bool EnteringContext) { 83 if (!SS.isSet() || SS.isInvalid()) 84 return 0; 85 86 NestedNameSpecifier *NNS 87 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 88 if (NNS->isDependent()) { 89 // If this nested-name-specifier refers to the current 90 // instantiation, return its DeclContext. 91 if (CXXRecordDecl *Record = getCurrentInstantiationOf(NNS)) 92 return Record; 93 94 if (EnteringContext) { 95 const Type *NNSType = NNS->getAsType(); 96 if (!NNSType) { 97 return 0; 98 } 99 100 // Look through type alias templates, per C++0x [temp.dep.type]p1. 101 NNSType = Context.getCanonicalType(NNSType); 102 if (const TemplateSpecializationType *SpecType 103 = NNSType->getAs<TemplateSpecializationType>()) { 104 // We are entering the context of the nested name specifier, so try to 105 // match the nested name specifier to either a primary class template 106 // or a class template partial specialization. 107 if (ClassTemplateDecl *ClassTemplate 108 = dyn_cast_or_null<ClassTemplateDecl>( 109 SpecType->getTemplateName().getAsTemplateDecl())) { 110 QualType ContextType 111 = Context.getCanonicalType(QualType(SpecType, 0)); 112 113 // If the type of the nested name specifier is the same as the 114 // injected class name of the named class template, we're entering 115 // into that class template definition. 116 QualType Injected 117 = ClassTemplate->getInjectedClassNameSpecialization(); 118 if (Context.hasSameType(Injected, ContextType)) 119 return ClassTemplate->getTemplatedDecl(); 120 121 // If the type of the nested name specifier is the same as the 122 // type of one of the class template's class template partial 123 // specializations, we're entering into the definition of that 124 // class template partial specialization. 125 if (ClassTemplatePartialSpecializationDecl *PartialSpec 126 = ClassTemplate->findPartialSpecialization(ContextType)) 127 return PartialSpec; 128 } 129 } else if (const RecordType *RecordT = NNSType->getAs<RecordType>()) { 130 // The nested name specifier refers to a member of a class template. 131 return RecordT->getDecl(); 132 } 133 } 134 135 return 0; 136 } 137 138 switch (NNS->getKind()) { 139 case NestedNameSpecifier::Identifier: 140 assert(false && "Dependent nested-name-specifier has no DeclContext"); 141 break; 142 143 case NestedNameSpecifier::Namespace: 144 return NNS->getAsNamespace(); 145 146 case NestedNameSpecifier::NamespaceAlias: 147 return NNS->getAsNamespaceAlias()->getNamespace(); 148 149 case NestedNameSpecifier::TypeSpec: 150 case NestedNameSpecifier::TypeSpecWithTemplate: { 151 const TagType *Tag = NNS->getAsType()->getAs<TagType>(); 152 assert(Tag && "Non-tag type in nested-name-specifier"); 153 return Tag->getDecl(); 154 } break; 155 156 case NestedNameSpecifier::Global: 157 return Context.getTranslationUnitDecl(); 158 } 159 160 // Required to silence a GCC warning. 161 return 0; 162} 163 164bool Sema::isDependentScopeSpecifier(const CXXScopeSpec &SS) { 165 if (!SS.isSet() || SS.isInvalid()) 166 return false; 167 168 NestedNameSpecifier *NNS 169 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 170 return NNS->isDependent(); 171} 172 173// \brief Determine whether this C++ scope specifier refers to an 174// unknown specialization, i.e., a dependent type that is not the 175// current instantiation. 176bool Sema::isUnknownSpecialization(const CXXScopeSpec &SS) { 177 if (!isDependentScopeSpecifier(SS)) 178 return false; 179 180 NestedNameSpecifier *NNS 181 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 182 return getCurrentInstantiationOf(NNS) == 0; 183} 184 185/// \brief If the given nested name specifier refers to the current 186/// instantiation, return the declaration that corresponds to that 187/// current instantiation (C++0x [temp.dep.type]p1). 188/// 189/// \param NNS a dependent nested name specifier. 190CXXRecordDecl *Sema::getCurrentInstantiationOf(NestedNameSpecifier *NNS) { 191 assert(getLangOptions().CPlusPlus && "Only callable in C++"); 192 assert(NNS->isDependent() && "Only dependent nested-name-specifier allowed"); 193 194 if (!NNS->getAsType()) 195 return 0; 196 197 QualType T = QualType(NNS->getAsType(), 0); 198 return ::getCurrentInstantiationOf(T, CurContext); 199} 200 201/// \brief Require that the context specified by SS be complete. 202/// 203/// If SS refers to a type, this routine checks whether the type is 204/// complete enough (or can be made complete enough) for name lookup 205/// into the DeclContext. A type that is not yet completed can be 206/// considered "complete enough" if it is a class/struct/union/enum 207/// that is currently being defined. Or, if we have a type that names 208/// a class template specialization that is not a complete type, we 209/// will attempt to instantiate that class template. 210bool Sema::RequireCompleteDeclContext(CXXScopeSpec &SS, 211 DeclContext *DC) { 212 assert(DC != 0 && "given null context"); 213 214 if (TagDecl *Tag = dyn_cast<TagDecl>(DC)) { 215 // If this is a dependent type, then we consider it complete. 216 if (Tag->isDependentContext()) 217 return false; 218 219 // If we're currently defining this type, then lookup into the 220 // type is okay: don't complain that it isn't complete yet. 221 const TagType *TagT = Context.getTypeDeclType(Tag)->getAs<TagType>(); 222 if (TagT && TagT->isBeingDefined()) 223 return false; 224 225 // The type must be complete. 226 if (RequireCompleteType(SS.getRange().getBegin(), 227 Context.getTypeDeclType(Tag), 228 PDiag(diag::err_incomplete_nested_name_spec) 229 << SS.getRange())) { 230 SS.SetInvalid(SS.getRange()); 231 return true; 232 } 233 } 234 235 return false; 236} 237 238bool Sema::ActOnCXXGlobalScopeSpecifier(Scope *S, SourceLocation CCLoc, 239 CXXScopeSpec &SS) { 240 SS.MakeGlobal(Context, CCLoc); 241 return false; 242} 243 244/// \brief Determines whether the given declaration is an valid acceptable 245/// result for name lookup of a nested-name-specifier. 246bool Sema::isAcceptableNestedNameSpecifier(NamedDecl *SD) { 247 if (!SD) 248 return false; 249 250 // Namespace and namespace aliases are fine. 251 if (isa<NamespaceDecl>(SD) || isa<NamespaceAliasDecl>(SD)) 252 return true; 253 254 if (!isa<TypeDecl>(SD)) 255 return false; 256 257 // Determine whether we have a class (or, in C++0x, an enum) or 258 // a typedef thereof. If so, build the nested-name-specifier. 259 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); 260 if (T->isDependentType()) 261 return true; 262 else if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(SD)) { 263 if (TD->getUnderlyingType()->isRecordType() || 264 (Context.getLangOptions().CPlusPlus0x && 265 TD->getUnderlyingType()->isEnumeralType())) 266 return true; 267 } else if (isa<RecordDecl>(SD) || 268 (Context.getLangOptions().CPlusPlus0x && isa<EnumDecl>(SD))) 269 return true; 270 271 return false; 272} 273 274/// \brief If the given nested-name-specifier begins with a bare identifier 275/// (e.g., Base::), perform name lookup for that identifier as a 276/// nested-name-specifier within the given scope, and return the result of that 277/// name lookup. 278NamedDecl *Sema::FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS) { 279 if (!S || !NNS) 280 return 0; 281 282 while (NNS->getPrefix()) 283 NNS = NNS->getPrefix(); 284 285 if (NNS->getKind() != NestedNameSpecifier::Identifier) 286 return 0; 287 288 LookupResult Found(*this, NNS->getAsIdentifier(), SourceLocation(), 289 LookupNestedNameSpecifierName); 290 LookupName(Found, S); 291 assert(!Found.isAmbiguous() && "Cannot handle ambiguities here yet"); 292 293 if (!Found.isSingleResult()) 294 return 0; 295 296 NamedDecl *Result = Found.getFoundDecl(); 297 if (isAcceptableNestedNameSpecifier(Result)) 298 return Result; 299 300 return 0; 301} 302 303bool Sema::isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS, 304 SourceLocation IdLoc, 305 IdentifierInfo &II, 306 ParsedType ObjectTypePtr) { 307 QualType ObjectType = GetTypeFromParser(ObjectTypePtr); 308 LookupResult Found(*this, &II, IdLoc, LookupNestedNameSpecifierName); 309 310 // Determine where to perform name lookup 311 DeclContext *LookupCtx = 0; 312 bool isDependent = false; 313 if (!ObjectType.isNull()) { 314 // This nested-name-specifier occurs in a member access expression, e.g., 315 // x->B::f, and we are looking into the type of the object. 316 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); 317 LookupCtx = computeDeclContext(ObjectType); 318 isDependent = ObjectType->isDependentType(); 319 } else if (SS.isSet()) { 320 // This nested-name-specifier occurs after another nested-name-specifier, 321 // so long into the context associated with the prior nested-name-specifier. 322 LookupCtx = computeDeclContext(SS, false); 323 isDependent = isDependentScopeSpecifier(SS); 324 Found.setContextRange(SS.getRange()); 325 } 326 327 if (LookupCtx) { 328 // Perform "qualified" name lookup into the declaration context we 329 // computed, which is either the type of the base of a member access 330 // expression or the declaration context associated with a prior 331 // nested-name-specifier. 332 333 // The declaration context must be complete. 334 if (!LookupCtx->isDependentContext() && 335 RequireCompleteDeclContext(SS, LookupCtx)) 336 return false; 337 338 LookupQualifiedName(Found, LookupCtx); 339 } else if (isDependent) { 340 return false; 341 } else { 342 LookupName(Found, S); 343 } 344 Found.suppressDiagnostics(); 345 346 if (NamedDecl *ND = Found.getAsSingle<NamedDecl>()) 347 return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND); 348 349 return false; 350} 351 352/// \brief Build a new nested-name-specifier for "identifier::", as described 353/// by ActOnCXXNestedNameSpecifier. 354/// 355/// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in 356/// that it contains an extra parameter \p ScopeLookupResult, which provides 357/// the result of name lookup within the scope of the nested-name-specifier 358/// that was computed at template definition time. 359/// 360/// If ErrorRecoveryLookup is true, then this call is used to improve error 361/// recovery. This means that it should not emit diagnostics, it should 362/// just return true on failure. It also means it should only return a valid 363/// scope if it *knows* that the result is correct. It should not return in a 364/// dependent context, for example. Nor will it extend \p SS with the scope 365/// specifier. 366bool Sema::BuildCXXNestedNameSpecifier(Scope *S, 367 IdentifierInfo &Identifier, 368 SourceLocation IdentifierLoc, 369 SourceLocation CCLoc, 370 QualType ObjectType, 371 bool EnteringContext, 372 CXXScopeSpec &SS, 373 NamedDecl *ScopeLookupResult, 374 bool ErrorRecoveryLookup) { 375 LookupResult Found(*this, &Identifier, IdentifierLoc, 376 LookupNestedNameSpecifierName); 377 378 // Determine where to perform name lookup 379 DeclContext *LookupCtx = 0; 380 bool isDependent = false; 381 if (!ObjectType.isNull()) { 382 // This nested-name-specifier occurs in a member access expression, e.g., 383 // x->B::f, and we are looking into the type of the object. 384 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); 385 LookupCtx = computeDeclContext(ObjectType); 386 isDependent = ObjectType->isDependentType(); 387 } else if (SS.isSet()) { 388 // This nested-name-specifier occurs after another nested-name-specifier, 389 // so look into the context associated with the prior nested-name-specifier. 390 LookupCtx = computeDeclContext(SS, EnteringContext); 391 isDependent = isDependentScopeSpecifier(SS); 392 Found.setContextRange(SS.getRange()); 393 } 394 395 396 bool ObjectTypeSearchedInScope = false; 397 if (LookupCtx) { 398 // Perform "qualified" name lookup into the declaration context we 399 // computed, which is either the type of the base of a member access 400 // expression or the declaration context associated with a prior 401 // nested-name-specifier. 402 403 // The declaration context must be complete. 404 if (!LookupCtx->isDependentContext() && 405 RequireCompleteDeclContext(SS, LookupCtx)) 406 return true; 407 408 LookupQualifiedName(Found, LookupCtx); 409 410 if (!ObjectType.isNull() && Found.empty()) { 411 // C++ [basic.lookup.classref]p4: 412 // If the id-expression in a class member access is a qualified-id of 413 // the form 414 // 415 // class-name-or-namespace-name::... 416 // 417 // the class-name-or-namespace-name following the . or -> operator is 418 // looked up both in the context of the entire postfix-expression and in 419 // the scope of the class of the object expression. If the name is found 420 // only in the scope of the class of the object expression, the name 421 // shall refer to a class-name. If the name is found only in the 422 // context of the entire postfix-expression, the name shall refer to a 423 // class-name or namespace-name. [...] 424 // 425 // Qualified name lookup into a class will not find a namespace-name, 426 // so we do not need to diagnose that case specifically. However, 427 // this qualified name lookup may find nothing. In that case, perform 428 // unqualified name lookup in the given scope (if available) or 429 // reconstruct the result from when name lookup was performed at template 430 // definition time. 431 if (S) 432 LookupName(Found, S); 433 else if (ScopeLookupResult) 434 Found.addDecl(ScopeLookupResult); 435 436 ObjectTypeSearchedInScope = true; 437 } 438 } else if (!isDependent) { 439 // Perform unqualified name lookup in the current scope. 440 LookupName(Found, S); 441 } 442 443 // If we performed lookup into a dependent context and did not find anything, 444 // that's fine: just build a dependent nested-name-specifier. 445 if (Found.empty() && isDependent && 446 !(LookupCtx && LookupCtx->isRecord() && 447 (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() || 448 !cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases()))) { 449 // Don't speculate if we're just trying to improve error recovery. 450 if (ErrorRecoveryLookup) 451 return true; 452 453 // We were not able to compute the declaration context for a dependent 454 // base object type or prior nested-name-specifier, so this 455 // nested-name-specifier refers to an unknown specialization. Just build 456 // a dependent nested-name-specifier. 457 SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc); 458 return false; 459 } 460 461 // FIXME: Deal with ambiguities cleanly. 462 463 if (Found.empty() && !ErrorRecoveryLookup) { 464 // We haven't found anything, and we're not recovering from a 465 // different kind of error, so look for typos. 466 DeclarationName Name = Found.getLookupName(); 467 if (CorrectTypo(Found, S, &SS, LookupCtx, EnteringContext, 468 CTC_NoKeywords) && 469 Found.isSingleResult() && 470 isAcceptableNestedNameSpecifier(Found.getAsSingle<NamedDecl>())) { 471 if (LookupCtx) 472 Diag(Found.getNameLoc(), diag::err_no_member_suggest) 473 << Name << LookupCtx << Found.getLookupName() << SS.getRange() 474 << FixItHint::CreateReplacement(Found.getNameLoc(), 475 Found.getLookupName().getAsString()); 476 else 477 Diag(Found.getNameLoc(), diag::err_undeclared_var_use_suggest) 478 << Name << Found.getLookupName() 479 << FixItHint::CreateReplacement(Found.getNameLoc(), 480 Found.getLookupName().getAsString()); 481 482 if (NamedDecl *ND = Found.getAsSingle<NamedDecl>()) 483 Diag(ND->getLocation(), diag::note_previous_decl) 484 << ND->getDeclName(); 485 } else { 486 Found.clear(); 487 Found.setLookupName(&Identifier); 488 } 489 } 490 491 NamedDecl *SD = Found.getAsSingle<NamedDecl>(); 492 if (isAcceptableNestedNameSpecifier(SD)) { 493 if (!ObjectType.isNull() && !ObjectTypeSearchedInScope) { 494 // C++ [basic.lookup.classref]p4: 495 // [...] If the name is found in both contexts, the 496 // class-name-or-namespace-name shall refer to the same entity. 497 // 498 // We already found the name in the scope of the object. Now, look 499 // into the current scope (the scope of the postfix-expression) to 500 // see if we can find the same name there. As above, if there is no 501 // scope, reconstruct the result from the template instantiation itself. 502 NamedDecl *OuterDecl; 503 if (S) { 504 LookupResult FoundOuter(*this, &Identifier, IdentifierLoc, 505 LookupNestedNameSpecifierName); 506 LookupName(FoundOuter, S); 507 OuterDecl = FoundOuter.getAsSingle<NamedDecl>(); 508 } else 509 OuterDecl = ScopeLookupResult; 510 511 if (isAcceptableNestedNameSpecifier(OuterDecl) && 512 OuterDecl->getCanonicalDecl() != SD->getCanonicalDecl() && 513 (!isa<TypeDecl>(OuterDecl) || !isa<TypeDecl>(SD) || 514 !Context.hasSameType( 515 Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)), 516 Context.getTypeDeclType(cast<TypeDecl>(SD))))) { 517 if (ErrorRecoveryLookup) 518 return true; 519 520 Diag(IdentifierLoc, 521 diag::err_nested_name_member_ref_lookup_ambiguous) 522 << &Identifier; 523 Diag(SD->getLocation(), diag::note_ambig_member_ref_object_type) 524 << ObjectType; 525 Diag(OuterDecl->getLocation(), diag::note_ambig_member_ref_scope); 526 527 // Fall through so that we'll pick the name we found in the object 528 // type, since that's probably what the user wanted anyway. 529 } 530 } 531 532 // If we're just performing this lookup for error-recovery purposes, 533 // don't extend the nested-name-specifier. Just return now. 534 if (ErrorRecoveryLookup) 535 return false; 536 537 if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD)) { 538 SS.Extend(Context, Namespace, IdentifierLoc, CCLoc); 539 return false; 540 } 541 542 if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD)) { 543 SS.Extend(Context, Alias, IdentifierLoc, CCLoc); 544 return false; 545 } 546 547 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); 548 TypeLocBuilder TLB; 549 if (isa<InjectedClassNameType>(T)) { 550 InjectedClassNameTypeLoc InjectedTL 551 = TLB.push<InjectedClassNameTypeLoc>(T); 552 InjectedTL.setNameLoc(IdentifierLoc); 553 } else if (isa<RecordType>(T)) { 554 RecordTypeLoc RecordTL = TLB.push<RecordTypeLoc>(T); 555 RecordTL.setNameLoc(IdentifierLoc); 556 } else if (isa<TypedefType>(T)) { 557 TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(T); 558 TypedefTL.setNameLoc(IdentifierLoc); 559 } else if (isa<EnumType>(T)) { 560 EnumTypeLoc EnumTL = TLB.push<EnumTypeLoc>(T); 561 EnumTL.setNameLoc(IdentifierLoc); 562 } else if (isa<TemplateTypeParmType>(T)) { 563 TemplateTypeParmTypeLoc TemplateTypeTL 564 = TLB.push<TemplateTypeParmTypeLoc>(T); 565 TemplateTypeTL.setNameLoc(IdentifierLoc); 566 } else if (isa<UnresolvedUsingType>(T)) { 567 UnresolvedUsingTypeLoc UnresolvedTL 568 = TLB.push<UnresolvedUsingTypeLoc>(T); 569 UnresolvedTL.setNameLoc(IdentifierLoc); 570 } else if (isa<SubstTemplateTypeParmType>(T)) { 571 SubstTemplateTypeParmTypeLoc TL 572 = TLB.push<SubstTemplateTypeParmTypeLoc>(T); 573 TL.setNameLoc(IdentifierLoc); 574 } else if (isa<SubstTemplateTypeParmPackType>(T)) { 575 SubstTemplateTypeParmPackTypeLoc TL 576 = TLB.push<SubstTemplateTypeParmPackTypeLoc>(T); 577 TL.setNameLoc(IdentifierLoc); 578 } else { 579 llvm_unreachable("Unhandled TypeDecl node in nested-name-specifier"); 580 } 581 582 SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T), 583 CCLoc); 584 return false; 585 } 586 587 // Otherwise, we have an error case. If we don't want diagnostics, just 588 // return an error now. 589 if (ErrorRecoveryLookup) 590 return true; 591 592 // If we didn't find anything during our lookup, try again with 593 // ordinary name lookup, which can help us produce better error 594 // messages. 595 if (Found.empty()) { 596 Found.clear(LookupOrdinaryName); 597 LookupName(Found, S); 598 } 599 600 unsigned DiagID; 601 if (!Found.empty()) 602 DiagID = diag::err_expected_class_or_namespace; 603 else if (SS.isSet()) { 604 Diag(IdentifierLoc, diag::err_no_member) 605 << &Identifier << LookupCtx << SS.getRange(); 606 return true; 607 } else 608 DiagID = diag::err_undeclared_var_use; 609 610 if (SS.isSet()) 611 Diag(IdentifierLoc, DiagID) << &Identifier << SS.getRange(); 612 else 613 Diag(IdentifierLoc, DiagID) << &Identifier; 614 615 return true; 616} 617 618bool Sema::ActOnCXXNestedNameSpecifier(Scope *S, 619 IdentifierInfo &Identifier, 620 SourceLocation IdentifierLoc, 621 SourceLocation CCLoc, 622 ParsedType ObjectType, 623 bool EnteringContext, 624 CXXScopeSpec &SS) { 625 if (SS.isInvalid()) 626 return true; 627 628 return BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, CCLoc, 629 GetTypeFromParser(ObjectType), 630 EnteringContext, SS, 631 /*ScopeLookupResult=*/0, false); 632} 633 634/// IsInvalidUnlessNestedName - This method is used for error recovery 635/// purposes to determine whether the specified identifier is only valid as 636/// a nested name specifier, for example a namespace name. It is 637/// conservatively correct to always return false from this method. 638/// 639/// The arguments are the same as those passed to ActOnCXXNestedNameSpecifier. 640bool Sema::IsInvalidUnlessNestedName(Scope *S, CXXScopeSpec &SS, 641 IdentifierInfo &Identifier, 642 SourceLocation IdentifierLoc, 643 SourceLocation ColonLoc, 644 ParsedType ObjectType, 645 bool EnteringContext) { 646 if (SS.isInvalid()) 647 return false; 648 649 return !BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, ColonLoc, 650 GetTypeFromParser(ObjectType), 651 EnteringContext, SS, 652 /*ScopeLookupResult=*/0, true); 653} 654 655bool Sema::ActOnCXXNestedNameSpecifier(Scope *S, 656 SourceLocation TemplateLoc, 657 CXXScopeSpec &SS, 658 TemplateTy Template, 659 SourceLocation TemplateNameLoc, 660 SourceLocation LAngleLoc, 661 ASTTemplateArgsPtr TemplateArgsIn, 662 SourceLocation RAngleLoc, 663 SourceLocation CCLoc, 664 bool EnteringContext) { 665 if (SS.isInvalid()) 666 return true; 667 668 // Translate the parser's template argument list in our AST format. 669 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); 670 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 671 672 if (DependentTemplateName *DTN = Template.get().getAsDependentTemplateName()){ 673 // Handle a dependent template specialization for which we cannot resolve 674 // the template name. 675 assert(DTN->getQualifier() 676 == static_cast<NestedNameSpecifier*>(SS.getScopeRep())); 677 QualType T = Context.getDependentTemplateSpecializationType(ETK_None, 678 DTN->getQualifier(), 679 DTN->getIdentifier(), 680 TemplateArgs); 681 682 // Create source-location information for this type. 683 TypeLocBuilder Builder; 684 DependentTemplateSpecializationTypeLoc SpecTL 685 = Builder.push<DependentTemplateSpecializationTypeLoc>(T); 686 SpecTL.setLAngleLoc(LAngleLoc); 687 SpecTL.setRAngleLoc(RAngleLoc); 688 SpecTL.setKeywordLoc(SourceLocation()); 689 SpecTL.setNameLoc(TemplateNameLoc); 690 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context)); 691 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 692 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); 693 694 SS.Extend(Context, TemplateLoc, Builder.getTypeLocInContext(Context, T), 695 CCLoc); 696 return false; 697 } 698 699 700 if (Template.get().getAsOverloadedTemplate() || 701 isa<FunctionTemplateDecl>(Template.get().getAsTemplateDecl())) { 702 SourceRange R(TemplateNameLoc, RAngleLoc); 703 if (SS.getRange().isValid()) 704 R.setBegin(SS.getRange().getBegin()); 705 706 Diag(CCLoc, diag::err_non_type_template_in_nested_name_specifier) 707 << Template.get() << R; 708 NoteAllFoundTemplates(Template.get()); 709 return true; 710 } 711 712 // We were able to resolve the template name to an actual template. 713 // Build an appropriate nested-name-specifier. 714 QualType T = CheckTemplateIdType(Template.get(), TemplateNameLoc, 715 TemplateArgs); 716 if (T.isNull()) 717 return true; 718 719 // Alias template specializations can produce types which are not valid 720 // nested name specifiers. 721 if (!T->isDependentType() && !T->getAs<TagType>()) { 722 Diag(TemplateNameLoc, diag::err_nested_name_spec_non_tag) << T; 723 NoteAllFoundTemplates(Template.get()); 724 return true; 725 } 726 727 // Provide source-location information for the template specialization 728 // type. 729 TypeLocBuilder Builder; 730 TemplateSpecializationTypeLoc SpecTL 731 = Builder.push<TemplateSpecializationTypeLoc>(T); 732 733 SpecTL.setLAngleLoc(LAngleLoc); 734 SpecTL.setRAngleLoc(RAngleLoc); 735 SpecTL.setTemplateNameLoc(TemplateNameLoc); 736 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 737 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); 738 739 740 SS.Extend(Context, TemplateLoc, Builder.getTypeLocInContext(Context, T), 741 CCLoc); 742 return false; 743} 744 745namespace { 746 /// \brief A structure that stores a nested-name-specifier annotation, 747 /// including both the nested-name-specifier 748 struct NestedNameSpecifierAnnotation { 749 NestedNameSpecifier *NNS; 750 }; 751} 752 753void *Sema::SaveNestedNameSpecifierAnnotation(CXXScopeSpec &SS) { 754 if (SS.isEmpty() || SS.isInvalid()) 755 return 0; 756 757 void *Mem = Context.Allocate((sizeof(NestedNameSpecifierAnnotation) + 758 SS.location_size()), 759 llvm::alignOf<NestedNameSpecifierAnnotation>()); 760 NestedNameSpecifierAnnotation *Annotation 761 = new (Mem) NestedNameSpecifierAnnotation; 762 Annotation->NNS = SS.getScopeRep(); 763 memcpy(Annotation + 1, SS.location_data(), SS.location_size()); 764 return Annotation; 765} 766 767void Sema::RestoreNestedNameSpecifierAnnotation(void *AnnotationPtr, 768 SourceRange AnnotationRange, 769 CXXScopeSpec &SS) { 770 if (!AnnotationPtr) { 771 SS.SetInvalid(AnnotationRange); 772 return; 773 } 774 775 NestedNameSpecifierAnnotation *Annotation 776 = static_cast<NestedNameSpecifierAnnotation *>(AnnotationPtr); 777 SS.Adopt(NestedNameSpecifierLoc(Annotation->NNS, Annotation + 1)); 778} 779 780bool Sema::ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { 781 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 782 783 NestedNameSpecifier *Qualifier = 784 static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 785 786 // There are only two places a well-formed program may qualify a 787 // declarator: first, when defining a namespace or class member 788 // out-of-line, and second, when naming an explicitly-qualified 789 // friend function. The latter case is governed by 790 // C++03 [basic.lookup.unqual]p10: 791 // In a friend declaration naming a member function, a name used 792 // in the function declarator and not part of a template-argument 793 // in a template-id is first looked up in the scope of the member 794 // function's class. If it is not found, or if the name is part of 795 // a template-argument in a template-id, the look up is as 796 // described for unqualified names in the definition of the class 797 // granting friendship. 798 // i.e. we don't push a scope unless it's a class member. 799 800 switch (Qualifier->getKind()) { 801 case NestedNameSpecifier::Global: 802 case NestedNameSpecifier::Namespace: 803 case NestedNameSpecifier::NamespaceAlias: 804 // These are always namespace scopes. We never want to enter a 805 // namespace scope from anything but a file context. 806 return CurContext->getRedeclContext()->isFileContext(); 807 808 case NestedNameSpecifier::Identifier: 809 case NestedNameSpecifier::TypeSpec: 810 case NestedNameSpecifier::TypeSpecWithTemplate: 811 // These are never namespace scopes. 812 return true; 813 } 814 815 // Silence bogus warning. 816 return false; 817} 818 819/// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global 820/// scope or nested-name-specifier) is parsed, part of a declarator-id. 821/// After this method is called, according to [C++ 3.4.3p3], names should be 822/// looked up in the declarator-id's scope, until the declarator is parsed and 823/// ActOnCXXExitDeclaratorScope is called. 824/// The 'SS' should be a non-empty valid CXXScopeSpec. 825bool Sema::ActOnCXXEnterDeclaratorScope(Scope *S, CXXScopeSpec &SS) { 826 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 827 828 if (SS.isInvalid()) return true; 829 830 DeclContext *DC = computeDeclContext(SS, true); 831 if (!DC) return true; 832 833 // Before we enter a declarator's context, we need to make sure that 834 // it is a complete declaration context. 835 if (!DC->isDependentContext() && RequireCompleteDeclContext(SS, DC)) 836 return true; 837 838 EnterDeclaratorContext(S, DC); 839 840 // Rebuild the nested name specifier for the new scope. 841 if (DC->isDependentContext()) 842 RebuildNestedNameSpecifierInCurrentInstantiation(SS); 843 844 return false; 845} 846 847/// ActOnCXXExitDeclaratorScope - Called when a declarator that previously 848/// invoked ActOnCXXEnterDeclaratorScope(), is finished. 'SS' is the same 849/// CXXScopeSpec that was passed to ActOnCXXEnterDeclaratorScope as well. 850/// Used to indicate that names should revert to being looked up in the 851/// defining scope. 852void Sema::ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { 853 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 854 if (SS.isInvalid()) 855 return; 856 assert(!SS.isInvalid() && computeDeclContext(SS, true) && 857 "exiting declarator scope we never really entered"); 858 ExitDeclaratorContext(S); 859} 860