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 "TypeLocBuilder.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 "clang/Sema/Lookup.h" 23#include "clang/Sema/Template.h" 24#include "llvm/ADT/STLExtras.h" 25#include "llvm/Support/raw_ostream.h" 26using namespace clang; 27 28/// \brief Find the current instantiation that associated with the given type. 29static CXXRecordDecl *getCurrentInstantiationOf(QualType T, 30 DeclContext *CurContext) { 31 if (T.isNull()) 32 return 0; 33 34 const Type *Ty = T->getCanonicalTypeInternal().getTypePtr(); 35 if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) { 36 CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordTy->getDecl()); 37 if (!Record->isDependentContext() || 38 Record->isCurrentInstantiation(CurContext)) 39 return Record; 40 41 return 0; 42 } else if (isa<InjectedClassNameType>(Ty)) 43 return cast<InjectedClassNameType>(Ty)->getDecl(); 44 else 45 return 0; 46} 47 48/// \brief Compute the DeclContext that is associated with the given type. 49/// 50/// \param T the type for which we are attempting to find a DeclContext. 51/// 52/// \returns the declaration context represented by the type T, 53/// or NULL if the declaration context cannot be computed (e.g., because it is 54/// dependent and not the current instantiation). 55DeclContext *Sema::computeDeclContext(QualType T) { 56 if (!T->isDependentType()) 57 if (const TagType *Tag = T->getAs<TagType>()) 58 return Tag->getDecl(); 59 60 return ::getCurrentInstantiationOf(T, CurContext); 61} 62 63/// \brief Compute the DeclContext that is associated with the given 64/// scope specifier. 65/// 66/// \param SS the C++ scope specifier as it appears in the source 67/// 68/// \param EnteringContext when true, we will be entering the context of 69/// this scope specifier, so we can retrieve the declaration context of a 70/// class template or class template partial specialization even if it is 71/// not the current instantiation. 72/// 73/// \returns the declaration context represented by the scope specifier @p SS, 74/// or NULL if the declaration context cannot be computed (e.g., because it is 75/// dependent and not the current instantiation). 76DeclContext *Sema::computeDeclContext(const CXXScopeSpec &SS, 77 bool EnteringContext) { 78 if (!SS.isSet() || SS.isInvalid()) 79 return 0; 80 81 NestedNameSpecifier *NNS = SS.getScopeRep(); 82 if (NNS->isDependent()) { 83 // If this nested-name-specifier refers to the current 84 // instantiation, return its DeclContext. 85 if (CXXRecordDecl *Record = getCurrentInstantiationOf(NNS)) 86 return Record; 87 88 if (EnteringContext) { 89 const Type *NNSType = NNS->getAsType(); 90 if (!NNSType) { 91 return 0; 92 } 93 94 // Look through type alias templates, per C++0x [temp.dep.type]p1. 95 NNSType = Context.getCanonicalType(NNSType); 96 if (const TemplateSpecializationType *SpecType 97 = NNSType->getAs<TemplateSpecializationType>()) { 98 // We are entering the context of the nested name specifier, so try to 99 // match the nested name specifier to either a primary class template 100 // or a class template partial specialization. 101 if (ClassTemplateDecl *ClassTemplate 102 = dyn_cast_or_null<ClassTemplateDecl>( 103 SpecType->getTemplateName().getAsTemplateDecl())) { 104 QualType ContextType 105 = Context.getCanonicalType(QualType(SpecType, 0)); 106 107 // If the type of the nested name specifier is the same as the 108 // injected class name of the named class template, we're entering 109 // into that class template definition. 110 QualType Injected 111 = ClassTemplate->getInjectedClassNameSpecialization(); 112 if (Context.hasSameType(Injected, ContextType)) 113 return ClassTemplate->getTemplatedDecl(); 114 115 // If the type of the nested name specifier is the same as the 116 // type of one of the class template's class template partial 117 // specializations, we're entering into the definition of that 118 // class template partial specialization. 119 if (ClassTemplatePartialSpecializationDecl *PartialSpec 120 = ClassTemplate->findPartialSpecialization(ContextType)) 121 return PartialSpec; 122 } 123 } else if (const RecordType *RecordT = NNSType->getAs<RecordType>()) { 124 // The nested name specifier refers to a member of a class template. 125 return RecordT->getDecl(); 126 } 127 } 128 129 return 0; 130 } 131 132 switch (NNS->getKind()) { 133 case NestedNameSpecifier::Identifier: 134 llvm_unreachable("Dependent nested-name-specifier has no DeclContext"); 135 136 case NestedNameSpecifier::Namespace: 137 return NNS->getAsNamespace(); 138 139 case NestedNameSpecifier::NamespaceAlias: 140 return NNS->getAsNamespaceAlias()->getNamespace(); 141 142 case NestedNameSpecifier::TypeSpec: 143 case NestedNameSpecifier::TypeSpecWithTemplate: { 144 const TagType *Tag = NNS->getAsType()->getAs<TagType>(); 145 assert(Tag && "Non-tag type in nested-name-specifier"); 146 return Tag->getDecl(); 147 } 148 149 case NestedNameSpecifier::Global: 150 return Context.getTranslationUnitDecl(); 151 } 152 153 llvm_unreachable("Invalid NestedNameSpecifier::Kind!"); 154} 155 156bool Sema::isDependentScopeSpecifier(const CXXScopeSpec &SS) { 157 if (!SS.isSet() || SS.isInvalid()) 158 return false; 159 160 return SS.getScopeRep()->isDependent(); 161} 162 163/// \brief If the given nested name specifier refers to the current 164/// instantiation, return the declaration that corresponds to that 165/// current instantiation (C++0x [temp.dep.type]p1). 166/// 167/// \param NNS a dependent nested name specifier. 168CXXRecordDecl *Sema::getCurrentInstantiationOf(NestedNameSpecifier *NNS) { 169 assert(getLangOpts().CPlusPlus && "Only callable in C++"); 170 assert(NNS->isDependent() && "Only dependent nested-name-specifier allowed"); 171 172 if (!NNS->getAsType()) 173 return 0; 174 175 QualType T = QualType(NNS->getAsType(), 0); 176 return ::getCurrentInstantiationOf(T, CurContext); 177} 178 179/// \brief Require that the context specified by SS be complete. 180/// 181/// If SS refers to a type, this routine checks whether the type is 182/// complete enough (or can be made complete enough) for name lookup 183/// into the DeclContext. A type that is not yet completed can be 184/// considered "complete enough" if it is a class/struct/union/enum 185/// that is currently being defined. Or, if we have a type that names 186/// a class template specialization that is not a complete type, we 187/// will attempt to instantiate that class template. 188bool Sema::RequireCompleteDeclContext(CXXScopeSpec &SS, 189 DeclContext *DC) { 190 assert(DC != 0 && "given null context"); 191 192 TagDecl *tag = dyn_cast<TagDecl>(DC); 193 194 // If this is a dependent type, then we consider it complete. 195 if (!tag || tag->isDependentContext()) 196 return false; 197 198 // If we're currently defining this type, then lookup into the 199 // type is okay: don't complain that it isn't complete yet. 200 QualType type = Context.getTypeDeclType(tag); 201 const TagType *tagType = type->getAs<TagType>(); 202 if (tagType && tagType->isBeingDefined()) 203 return false; 204 205 SourceLocation loc = SS.getLastQualifierNameLoc(); 206 if (loc.isInvalid()) loc = SS.getRange().getBegin(); 207 208 // The type must be complete. 209 if (RequireCompleteType(loc, type, diag::err_incomplete_nested_name_spec, 210 SS.getRange())) { 211 SS.SetInvalid(SS.getRange()); 212 return true; 213 } 214 215 // Fixed enum types are complete, but they aren't valid as scopes 216 // until we see a definition, so awkwardly pull out this special 217 // case. 218 const EnumType *enumType = dyn_cast_or_null<EnumType>(tagType); 219 if (!enumType || enumType->getDecl()->isCompleteDefinition()) 220 return false; 221 222 // Try to instantiate the definition, if this is a specialization of an 223 // enumeration temploid. 224 EnumDecl *ED = enumType->getDecl(); 225 if (EnumDecl *Pattern = ED->getInstantiatedFromMemberEnum()) { 226 MemberSpecializationInfo *MSI = ED->getMemberSpecializationInfo(); 227 if (MSI->getTemplateSpecializationKind() != TSK_ExplicitSpecialization) { 228 if (InstantiateEnum(loc, ED, Pattern, getTemplateInstantiationArgs(ED), 229 TSK_ImplicitInstantiation)) { 230 SS.SetInvalid(SS.getRange()); 231 return true; 232 } 233 return false; 234 } 235 } 236 237 Diag(loc, diag::err_incomplete_nested_name_spec) 238 << type << SS.getRange(); 239 SS.SetInvalid(SS.getRange()); 240 return true; 241} 242 243bool Sema::ActOnCXXGlobalScopeSpecifier(Scope *S, SourceLocation CCLoc, 244 CXXScopeSpec &SS) { 245 SS.MakeGlobal(Context, CCLoc); 246 return false; 247} 248 249/// \brief Determines whether the given declaration is an valid acceptable 250/// result for name lookup of a nested-name-specifier. 251bool Sema::isAcceptableNestedNameSpecifier(const NamedDecl *SD) { 252 if (!SD) 253 return false; 254 255 // Namespace and namespace aliases are fine. 256 if (isa<NamespaceDecl>(SD) || isa<NamespaceAliasDecl>(SD)) 257 return true; 258 259 if (!isa<TypeDecl>(SD)) 260 return false; 261 262 // Determine whether we have a class (or, in C++11, an enum) or 263 // a typedef thereof. If so, build the nested-name-specifier. 264 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); 265 if (T->isDependentType()) 266 return true; 267 else if (const TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(SD)) { 268 if (TD->getUnderlyingType()->isRecordType() || 269 (Context.getLangOpts().CPlusPlus11 && 270 TD->getUnderlyingType()->isEnumeralType())) 271 return true; 272 } else if (isa<RecordDecl>(SD) || 273 (Context.getLangOpts().CPlusPlus11 && isa<EnumDecl>(SD))) 274 return true; 275 276 return false; 277} 278 279/// \brief If the given nested-name-specifier begins with a bare identifier 280/// (e.g., Base::), perform name lookup for that identifier as a 281/// nested-name-specifier within the given scope, and return the result of that 282/// name lookup. 283NamedDecl *Sema::FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS) { 284 if (!S || !NNS) 285 return 0; 286 287 while (NNS->getPrefix()) 288 NNS = NNS->getPrefix(); 289 290 if (NNS->getKind() != NestedNameSpecifier::Identifier) 291 return 0; 292 293 LookupResult Found(*this, NNS->getAsIdentifier(), SourceLocation(), 294 LookupNestedNameSpecifierName); 295 LookupName(Found, S); 296 assert(!Found.isAmbiguous() && "Cannot handle ambiguities here yet"); 297 298 if (!Found.isSingleResult()) 299 return 0; 300 301 NamedDecl *Result = Found.getFoundDecl(); 302 if (isAcceptableNestedNameSpecifier(Result)) 303 return Result; 304 305 return 0; 306} 307 308bool Sema::isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS, 309 SourceLocation IdLoc, 310 IdentifierInfo &II, 311 ParsedType ObjectTypePtr) { 312 QualType ObjectType = GetTypeFromParser(ObjectTypePtr); 313 LookupResult Found(*this, &II, IdLoc, LookupNestedNameSpecifierName); 314 315 // Determine where to perform name lookup 316 DeclContext *LookupCtx = 0; 317 bool isDependent = false; 318 if (!ObjectType.isNull()) { 319 // This nested-name-specifier occurs in a member access expression, e.g., 320 // x->B::f, and we are looking into the type of the object. 321 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); 322 LookupCtx = computeDeclContext(ObjectType); 323 isDependent = ObjectType->isDependentType(); 324 } else if (SS.isSet()) { 325 // This nested-name-specifier occurs after another nested-name-specifier, 326 // so long into the context associated with the prior nested-name-specifier. 327 LookupCtx = computeDeclContext(SS, false); 328 isDependent = isDependentScopeSpecifier(SS); 329 Found.setContextRange(SS.getRange()); 330 } 331 332 if (LookupCtx) { 333 // Perform "qualified" name lookup into the declaration context we 334 // computed, which is either the type of the base of a member access 335 // expression or the declaration context associated with a prior 336 // nested-name-specifier. 337 338 // The declaration context must be complete. 339 if (!LookupCtx->isDependentContext() && 340 RequireCompleteDeclContext(SS, LookupCtx)) 341 return false; 342 343 LookupQualifiedName(Found, LookupCtx); 344 } else if (isDependent) { 345 return false; 346 } else { 347 LookupName(Found, S); 348 } 349 Found.suppressDiagnostics(); 350 351 if (NamedDecl *ND = Found.getAsSingle<NamedDecl>()) 352 return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND); 353 354 return false; 355} 356 357namespace { 358 359// Callback to only accept typo corrections that can be a valid C++ member 360// intializer: either a non-static field member or a base class. 361class NestedNameSpecifierValidatorCCC : public CorrectionCandidateCallback { 362 public: 363 explicit NestedNameSpecifierValidatorCCC(Sema &SRef) 364 : SRef(SRef) {} 365 366 virtual bool ValidateCandidate(const TypoCorrection &candidate) { 367 return SRef.isAcceptableNestedNameSpecifier(candidate.getCorrectionDecl()); 368 } 369 370 private: 371 Sema &SRef; 372}; 373 374} 375 376/// \brief Build a new nested-name-specifier for "identifier::", as described 377/// by ActOnCXXNestedNameSpecifier. 378/// 379/// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in 380/// that it contains an extra parameter \p ScopeLookupResult, which provides 381/// the result of name lookup within the scope of the nested-name-specifier 382/// that was computed at template definition time. 383/// 384/// If ErrorRecoveryLookup is true, then this call is used to improve error 385/// recovery. This means that it should not emit diagnostics, it should 386/// just return true on failure. It also means it should only return a valid 387/// scope if it *knows* that the result is correct. It should not return in a 388/// dependent context, for example. Nor will it extend \p SS with the scope 389/// specifier. 390bool Sema::BuildCXXNestedNameSpecifier(Scope *S, 391 IdentifierInfo &Identifier, 392 SourceLocation IdentifierLoc, 393 SourceLocation CCLoc, 394 QualType ObjectType, 395 bool EnteringContext, 396 CXXScopeSpec &SS, 397 NamedDecl *ScopeLookupResult, 398 bool ErrorRecoveryLookup) { 399 LookupResult Found(*this, &Identifier, IdentifierLoc, 400 LookupNestedNameSpecifierName); 401 402 // Determine where to perform name lookup 403 DeclContext *LookupCtx = 0; 404 bool isDependent = false; 405 if (!ObjectType.isNull()) { 406 // This nested-name-specifier occurs in a member access expression, e.g., 407 // x->B::f, and we are looking into the type of the object. 408 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); 409 LookupCtx = computeDeclContext(ObjectType); 410 isDependent = ObjectType->isDependentType(); 411 } else if (SS.isSet()) { 412 // This nested-name-specifier occurs after another nested-name-specifier, 413 // so look into the context associated with the prior nested-name-specifier. 414 LookupCtx = computeDeclContext(SS, EnteringContext); 415 isDependent = isDependentScopeSpecifier(SS); 416 Found.setContextRange(SS.getRange()); 417 } 418 419 420 bool ObjectTypeSearchedInScope = false; 421 if (LookupCtx) { 422 // Perform "qualified" name lookup into the declaration context we 423 // computed, which is either the type of the base of a member access 424 // expression or the declaration context associated with a prior 425 // nested-name-specifier. 426 427 // The declaration context must be complete. 428 if (!LookupCtx->isDependentContext() && 429 RequireCompleteDeclContext(SS, LookupCtx)) 430 return true; 431 432 LookupQualifiedName(Found, LookupCtx); 433 434 if (!ObjectType.isNull() && Found.empty()) { 435 // C++ [basic.lookup.classref]p4: 436 // If the id-expression in a class member access is a qualified-id of 437 // the form 438 // 439 // class-name-or-namespace-name::... 440 // 441 // the class-name-or-namespace-name following the . or -> operator is 442 // looked up both in the context of the entire postfix-expression and in 443 // the scope of the class of the object expression. If the name is found 444 // only in the scope of the class of the object expression, the name 445 // shall refer to a class-name. If the name is found only in the 446 // context of the entire postfix-expression, the name shall refer to a 447 // class-name or namespace-name. [...] 448 // 449 // Qualified name lookup into a class will not find a namespace-name, 450 // so we do not need to diagnose that case specifically. However, 451 // this qualified name lookup may find nothing. In that case, perform 452 // unqualified name lookup in the given scope (if available) or 453 // reconstruct the result from when name lookup was performed at template 454 // definition time. 455 if (S) 456 LookupName(Found, S); 457 else if (ScopeLookupResult) 458 Found.addDecl(ScopeLookupResult); 459 460 ObjectTypeSearchedInScope = true; 461 } 462 } else if (!isDependent) { 463 // Perform unqualified name lookup in the current scope. 464 LookupName(Found, S); 465 } 466 467 // If we performed lookup into a dependent context and did not find anything, 468 // that's fine: just build a dependent nested-name-specifier. 469 if (Found.empty() && isDependent && 470 !(LookupCtx && LookupCtx->isRecord() && 471 (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() || 472 !cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases()))) { 473 // Don't speculate if we're just trying to improve error recovery. 474 if (ErrorRecoveryLookup) 475 return true; 476 477 // We were not able to compute the declaration context for a dependent 478 // base object type or prior nested-name-specifier, so this 479 // nested-name-specifier refers to an unknown specialization. Just build 480 // a dependent nested-name-specifier. 481 SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc); 482 return false; 483 } 484 485 // FIXME: Deal with ambiguities cleanly. 486 487 if (Found.empty() && !ErrorRecoveryLookup && !getLangOpts().MicrosoftMode) { 488 // We haven't found anything, and we're not recovering from a 489 // different kind of error, so look for typos. 490 DeclarationName Name = Found.getLookupName(); 491 NestedNameSpecifierValidatorCCC Validator(*this); 492 Found.clear(); 493 if (TypoCorrection Corrected = 494 CorrectTypo(Found.getLookupNameInfo(), Found.getLookupKind(), S, 495 &SS, Validator, LookupCtx, EnteringContext)) { 496 if (LookupCtx) { 497 bool DroppedSpecifier = 498 Corrected.WillReplaceSpecifier() && 499 Name.getAsString() == Corrected.getAsString(getLangOpts()); 500 if (DroppedSpecifier) 501 SS.clear(); 502 diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest) 503 << Name << LookupCtx << DroppedSpecifier 504 << SS.getRange()); 505 } else 506 diagnoseTypo(Corrected, PDiag(diag::err_undeclared_var_use_suggest) 507 << Name); 508 509 if (NamedDecl *ND = Corrected.getCorrectionDecl()) 510 Found.addDecl(ND); 511 Found.setLookupName(Corrected.getCorrection()); 512 } else { 513 Found.setLookupName(&Identifier); 514 } 515 } 516 517 NamedDecl *SD = Found.getAsSingle<NamedDecl>(); 518 if (isAcceptableNestedNameSpecifier(SD)) { 519 if (!ObjectType.isNull() && !ObjectTypeSearchedInScope && 520 !getLangOpts().CPlusPlus11) { 521 // C++03 [basic.lookup.classref]p4: 522 // [...] If the name is found in both contexts, the 523 // class-name-or-namespace-name shall refer to the same entity. 524 // 525 // We already found the name in the scope of the object. Now, look 526 // into the current scope (the scope of the postfix-expression) to 527 // see if we can find the same name there. As above, if there is no 528 // scope, reconstruct the result from the template instantiation itself. 529 // 530 // Note that C++11 does *not* perform this redundant lookup. 531 NamedDecl *OuterDecl; 532 if (S) { 533 LookupResult FoundOuter(*this, &Identifier, IdentifierLoc, 534 LookupNestedNameSpecifierName); 535 LookupName(FoundOuter, S); 536 OuterDecl = FoundOuter.getAsSingle<NamedDecl>(); 537 } else 538 OuterDecl = ScopeLookupResult; 539 540 if (isAcceptableNestedNameSpecifier(OuterDecl) && 541 OuterDecl->getCanonicalDecl() != SD->getCanonicalDecl() && 542 (!isa<TypeDecl>(OuterDecl) || !isa<TypeDecl>(SD) || 543 !Context.hasSameType( 544 Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)), 545 Context.getTypeDeclType(cast<TypeDecl>(SD))))) { 546 if (ErrorRecoveryLookup) 547 return true; 548 549 Diag(IdentifierLoc, 550 diag::err_nested_name_member_ref_lookup_ambiguous) 551 << &Identifier; 552 Diag(SD->getLocation(), diag::note_ambig_member_ref_object_type) 553 << ObjectType; 554 Diag(OuterDecl->getLocation(), diag::note_ambig_member_ref_scope); 555 556 // Fall through so that we'll pick the name we found in the object 557 // type, since that's probably what the user wanted anyway. 558 } 559 } 560 561 // If we're just performing this lookup for error-recovery purposes, 562 // don't extend the nested-name-specifier. Just return now. 563 if (ErrorRecoveryLookup) 564 return false; 565 566 if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD)) { 567 SS.Extend(Context, Namespace, IdentifierLoc, CCLoc); 568 return false; 569 } 570 571 if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD)) { 572 SS.Extend(Context, Alias, IdentifierLoc, CCLoc); 573 return false; 574 } 575 576 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); 577 TypeLocBuilder TLB; 578 if (isa<InjectedClassNameType>(T)) { 579 InjectedClassNameTypeLoc InjectedTL 580 = TLB.push<InjectedClassNameTypeLoc>(T); 581 InjectedTL.setNameLoc(IdentifierLoc); 582 } else if (isa<RecordType>(T)) { 583 RecordTypeLoc RecordTL = TLB.push<RecordTypeLoc>(T); 584 RecordTL.setNameLoc(IdentifierLoc); 585 } else if (isa<TypedefType>(T)) { 586 TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(T); 587 TypedefTL.setNameLoc(IdentifierLoc); 588 } else if (isa<EnumType>(T)) { 589 EnumTypeLoc EnumTL = TLB.push<EnumTypeLoc>(T); 590 EnumTL.setNameLoc(IdentifierLoc); 591 } else if (isa<TemplateTypeParmType>(T)) { 592 TemplateTypeParmTypeLoc TemplateTypeTL 593 = TLB.push<TemplateTypeParmTypeLoc>(T); 594 TemplateTypeTL.setNameLoc(IdentifierLoc); 595 } else if (isa<UnresolvedUsingType>(T)) { 596 UnresolvedUsingTypeLoc UnresolvedTL 597 = TLB.push<UnresolvedUsingTypeLoc>(T); 598 UnresolvedTL.setNameLoc(IdentifierLoc); 599 } else if (isa<SubstTemplateTypeParmType>(T)) { 600 SubstTemplateTypeParmTypeLoc TL 601 = TLB.push<SubstTemplateTypeParmTypeLoc>(T); 602 TL.setNameLoc(IdentifierLoc); 603 } else if (isa<SubstTemplateTypeParmPackType>(T)) { 604 SubstTemplateTypeParmPackTypeLoc TL 605 = TLB.push<SubstTemplateTypeParmPackTypeLoc>(T); 606 TL.setNameLoc(IdentifierLoc); 607 } else { 608 llvm_unreachable("Unhandled TypeDecl node in nested-name-specifier"); 609 } 610 611 if (T->isEnumeralType()) 612 Diag(IdentifierLoc, diag::warn_cxx98_compat_enum_nested_name_spec); 613 614 SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T), 615 CCLoc); 616 return false; 617 } 618 619 // Otherwise, we have an error case. If we don't want diagnostics, just 620 // return an error now. 621 if (ErrorRecoveryLookup) 622 return true; 623 624 // If we didn't find anything during our lookup, try again with 625 // ordinary name lookup, which can help us produce better error 626 // messages. 627 if (Found.empty()) { 628 Found.clear(LookupOrdinaryName); 629 LookupName(Found, S); 630 } 631 632 // In Microsoft mode, if we are within a templated function and we can't 633 // resolve Identifier, then extend the SS with Identifier. This will have 634 // the effect of resolving Identifier during template instantiation. 635 // The goal is to be able to resolve a function call whose 636 // nested-name-specifier is located inside a dependent base class. 637 // Example: 638 // 639 // class C { 640 // public: 641 // static void foo2() { } 642 // }; 643 // template <class T> class A { public: typedef C D; }; 644 // 645 // template <class T> class B : public A<T> { 646 // public: 647 // void foo() { D::foo2(); } 648 // }; 649 if (getLangOpts().MicrosoftMode) { 650 DeclContext *DC = LookupCtx ? LookupCtx : CurContext; 651 if (DC->isDependentContext() && DC->isFunctionOrMethod()) { 652 SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc); 653 return false; 654 } 655 } 656 657 unsigned DiagID; 658 if (!Found.empty()) 659 DiagID = diag::err_expected_class_or_namespace; 660 else if (SS.isSet()) { 661 Diag(IdentifierLoc, diag::err_no_member) 662 << &Identifier << LookupCtx << SS.getRange(); 663 return true; 664 } else 665 DiagID = diag::err_undeclared_var_use; 666 667 if (SS.isSet()) 668 Diag(IdentifierLoc, DiagID) << &Identifier << SS.getRange(); 669 else 670 Diag(IdentifierLoc, DiagID) << &Identifier; 671 672 return true; 673} 674 675bool Sema::ActOnCXXNestedNameSpecifier(Scope *S, 676 IdentifierInfo &Identifier, 677 SourceLocation IdentifierLoc, 678 SourceLocation CCLoc, 679 ParsedType ObjectType, 680 bool EnteringContext, 681 CXXScopeSpec &SS) { 682 if (SS.isInvalid()) 683 return true; 684 685 return BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, CCLoc, 686 GetTypeFromParser(ObjectType), 687 EnteringContext, SS, 688 /*ScopeLookupResult=*/0, false); 689} 690 691bool Sema::ActOnCXXNestedNameSpecifierDecltype(CXXScopeSpec &SS, 692 const DeclSpec &DS, 693 SourceLocation ColonColonLoc) { 694 if (SS.isInvalid() || DS.getTypeSpecType() == DeclSpec::TST_error) 695 return true; 696 697 assert(DS.getTypeSpecType() == DeclSpec::TST_decltype); 698 699 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc()); 700 if (!T->isDependentType() && !T->getAs<TagType>()) { 701 Diag(DS.getTypeSpecTypeLoc(), diag::err_expected_class) 702 << T << getLangOpts().CPlusPlus; 703 return true; 704 } 705 706 TypeLocBuilder TLB; 707 DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T); 708 DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc()); 709 SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T), 710 ColonColonLoc); 711 return false; 712} 713 714/// IsInvalidUnlessNestedName - This method is used for error recovery 715/// purposes to determine whether the specified identifier is only valid as 716/// a nested name specifier, for example a namespace name. It is 717/// conservatively correct to always return false from this method. 718/// 719/// The arguments are the same as those passed to ActOnCXXNestedNameSpecifier. 720bool Sema::IsInvalidUnlessNestedName(Scope *S, CXXScopeSpec &SS, 721 IdentifierInfo &Identifier, 722 SourceLocation IdentifierLoc, 723 SourceLocation ColonLoc, 724 ParsedType ObjectType, 725 bool EnteringContext) { 726 if (SS.isInvalid()) 727 return false; 728 729 return !BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, ColonLoc, 730 GetTypeFromParser(ObjectType), 731 EnteringContext, SS, 732 /*ScopeLookupResult=*/0, true); 733} 734 735bool Sema::ActOnCXXNestedNameSpecifier(Scope *S, 736 CXXScopeSpec &SS, 737 SourceLocation TemplateKWLoc, 738 TemplateTy Template, 739 SourceLocation TemplateNameLoc, 740 SourceLocation LAngleLoc, 741 ASTTemplateArgsPtr TemplateArgsIn, 742 SourceLocation RAngleLoc, 743 SourceLocation CCLoc, 744 bool EnteringContext) { 745 if (SS.isInvalid()) 746 return true; 747 748 // Translate the parser's template argument list in our AST format. 749 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); 750 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 751 752 if (DependentTemplateName *DTN = Template.get().getAsDependentTemplateName()){ 753 // Handle a dependent template specialization for which we cannot resolve 754 // the template name. 755 assert(DTN->getQualifier() == SS.getScopeRep()); 756 QualType T = Context.getDependentTemplateSpecializationType(ETK_None, 757 DTN->getQualifier(), 758 DTN->getIdentifier(), 759 TemplateArgs); 760 761 // Create source-location information for this type. 762 TypeLocBuilder Builder; 763 DependentTemplateSpecializationTypeLoc SpecTL 764 = Builder.push<DependentTemplateSpecializationTypeLoc>(T); 765 SpecTL.setElaboratedKeywordLoc(SourceLocation()); 766 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context)); 767 SpecTL.setTemplateKeywordLoc(TemplateKWLoc); 768 SpecTL.setTemplateNameLoc(TemplateNameLoc); 769 SpecTL.setLAngleLoc(LAngleLoc); 770 SpecTL.setRAngleLoc(RAngleLoc); 771 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 772 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); 773 774 SS.Extend(Context, TemplateKWLoc, Builder.getTypeLocInContext(Context, T), 775 CCLoc); 776 return false; 777 } 778 779 780 if (Template.get().getAsOverloadedTemplate() || 781 isa<FunctionTemplateDecl>(Template.get().getAsTemplateDecl())) { 782 SourceRange R(TemplateNameLoc, RAngleLoc); 783 if (SS.getRange().isValid()) 784 R.setBegin(SS.getRange().getBegin()); 785 786 Diag(CCLoc, diag::err_non_type_template_in_nested_name_specifier) 787 << Template.get() << R; 788 NoteAllFoundTemplates(Template.get()); 789 return true; 790 } 791 792 // We were able to resolve the template name to an actual template. 793 // Build an appropriate nested-name-specifier. 794 QualType T = CheckTemplateIdType(Template.get(), TemplateNameLoc, 795 TemplateArgs); 796 if (T.isNull()) 797 return true; 798 799 // Alias template specializations can produce types which are not valid 800 // nested name specifiers. 801 if (!T->isDependentType() && !T->getAs<TagType>()) { 802 Diag(TemplateNameLoc, diag::err_nested_name_spec_non_tag) << T; 803 NoteAllFoundTemplates(Template.get()); 804 return true; 805 } 806 807 // Provide source-location information for the template specialization type. 808 TypeLocBuilder Builder; 809 TemplateSpecializationTypeLoc SpecTL 810 = Builder.push<TemplateSpecializationTypeLoc>(T); 811 SpecTL.setTemplateKeywordLoc(TemplateKWLoc); 812 SpecTL.setTemplateNameLoc(TemplateNameLoc); 813 SpecTL.setLAngleLoc(LAngleLoc); 814 SpecTL.setRAngleLoc(RAngleLoc); 815 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 816 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); 817 818 819 SS.Extend(Context, TemplateKWLoc, Builder.getTypeLocInContext(Context, T), 820 CCLoc); 821 return false; 822} 823 824namespace { 825 /// \brief A structure that stores a nested-name-specifier annotation, 826 /// including both the nested-name-specifier 827 struct NestedNameSpecifierAnnotation { 828 NestedNameSpecifier *NNS; 829 }; 830} 831 832void *Sema::SaveNestedNameSpecifierAnnotation(CXXScopeSpec &SS) { 833 if (SS.isEmpty() || SS.isInvalid()) 834 return 0; 835 836 void *Mem = Context.Allocate((sizeof(NestedNameSpecifierAnnotation) + 837 SS.location_size()), 838 llvm::alignOf<NestedNameSpecifierAnnotation>()); 839 NestedNameSpecifierAnnotation *Annotation 840 = new (Mem) NestedNameSpecifierAnnotation; 841 Annotation->NNS = SS.getScopeRep(); 842 memcpy(Annotation + 1, SS.location_data(), SS.location_size()); 843 return Annotation; 844} 845 846void Sema::RestoreNestedNameSpecifierAnnotation(void *AnnotationPtr, 847 SourceRange AnnotationRange, 848 CXXScopeSpec &SS) { 849 if (!AnnotationPtr) { 850 SS.SetInvalid(AnnotationRange); 851 return; 852 } 853 854 NestedNameSpecifierAnnotation *Annotation 855 = static_cast<NestedNameSpecifierAnnotation *>(AnnotationPtr); 856 SS.Adopt(NestedNameSpecifierLoc(Annotation->NNS, Annotation + 1)); 857} 858 859bool Sema::ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { 860 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 861 862 NestedNameSpecifier *Qualifier = SS.getScopeRep(); 863 864 // There are only two places a well-formed program may qualify a 865 // declarator: first, when defining a namespace or class member 866 // out-of-line, and second, when naming an explicitly-qualified 867 // friend function. The latter case is governed by 868 // C++03 [basic.lookup.unqual]p10: 869 // In a friend declaration naming a member function, a name used 870 // in the function declarator and not part of a template-argument 871 // in a template-id is first looked up in the scope of the member 872 // function's class. If it is not found, or if the name is part of 873 // a template-argument in a template-id, the look up is as 874 // described for unqualified names in the definition of the class 875 // granting friendship. 876 // i.e. we don't push a scope unless it's a class member. 877 878 switch (Qualifier->getKind()) { 879 case NestedNameSpecifier::Global: 880 case NestedNameSpecifier::Namespace: 881 case NestedNameSpecifier::NamespaceAlias: 882 // These are always namespace scopes. We never want to enter a 883 // namespace scope from anything but a file context. 884 return CurContext->getRedeclContext()->isFileContext(); 885 886 case NestedNameSpecifier::Identifier: 887 case NestedNameSpecifier::TypeSpec: 888 case NestedNameSpecifier::TypeSpecWithTemplate: 889 // These are never namespace scopes. 890 return true; 891 } 892 893 llvm_unreachable("Invalid NestedNameSpecifier::Kind!"); 894} 895 896/// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global 897/// scope or nested-name-specifier) is parsed, part of a declarator-id. 898/// After this method is called, according to [C++ 3.4.3p3], names should be 899/// looked up in the declarator-id's scope, until the declarator is parsed and 900/// ActOnCXXExitDeclaratorScope is called. 901/// The 'SS' should be a non-empty valid CXXScopeSpec. 902bool Sema::ActOnCXXEnterDeclaratorScope(Scope *S, CXXScopeSpec &SS) { 903 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 904 905 if (SS.isInvalid()) return true; 906 907 DeclContext *DC = computeDeclContext(SS, true); 908 if (!DC) return true; 909 910 // Before we enter a declarator's context, we need to make sure that 911 // it is a complete declaration context. 912 if (!DC->isDependentContext() && RequireCompleteDeclContext(SS, DC)) 913 return true; 914 915 EnterDeclaratorContext(S, DC); 916 917 // Rebuild the nested name specifier for the new scope. 918 if (DC->isDependentContext()) 919 RebuildNestedNameSpecifierInCurrentInstantiation(SS); 920 921 return false; 922} 923 924/// ActOnCXXExitDeclaratorScope - Called when a declarator that previously 925/// invoked ActOnCXXEnterDeclaratorScope(), is finished. 'SS' is the same 926/// CXXScopeSpec that was passed to ActOnCXXEnterDeclaratorScope as well. 927/// Used to indicate that names should revert to being looked up in the 928/// defining scope. 929void Sema::ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { 930 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 931 if (SS.isInvalid()) 932 return; 933 assert(!SS.isInvalid() && computeDeclContext(SS, true) && 934 "exiting declarator scope we never really entered"); 935 ExitDeclaratorContext(S); 936} 937