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" 25 using namespace clang; 26 27 /// \brief Find the current instantiation that associated with the given type. 28 static 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). 60 DeclContext *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). 81 DeclContext *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 llvm_unreachable("Dependent nested-name-specifier has no DeclContext"); 141 142 case NestedNameSpecifier::Namespace: 143 return NNS->getAsNamespace(); 144 145 case NestedNameSpecifier::NamespaceAlias: 146 return NNS->getAsNamespaceAlias()->getNamespace(); 147 148 case NestedNameSpecifier::TypeSpec: 149 case NestedNameSpecifier::TypeSpecWithTemplate: { 150 const TagType *Tag = NNS->getAsType()->getAs<TagType>(); 151 assert(Tag && "Non-tag type in nested-name-specifier"); 152 return Tag->getDecl(); 153 } break; 154 155 case NestedNameSpecifier::Global: 156 return Context.getTranslationUnitDecl(); 157 } 158 159 // Required to silence a GCC warning. 160 return 0; 161 } 162 163 bool Sema::isDependentScopeSpecifier(const CXXScopeSpec &SS) { 164 if (!SS.isSet() || SS.isInvalid()) 165 return false; 166 167 NestedNameSpecifier *NNS 168 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 169 return NNS->isDependent(); 170 } 171 172 // \brief Determine whether this C++ scope specifier refers to an 173 // unknown specialization, i.e., a dependent type that is not the 174 // current instantiation. 175 bool Sema::isUnknownSpecialization(const CXXScopeSpec &SS) { 176 if (!isDependentScopeSpecifier(SS)) 177 return false; 178 179 NestedNameSpecifier *NNS 180 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 181 return getCurrentInstantiationOf(NNS) == 0; 182 } 183 184 /// \brief If the given nested name specifier refers to the current 185 /// instantiation, return the declaration that corresponds to that 186 /// current instantiation (C++0x [temp.dep.type]p1). 187 /// 188 /// \param NNS a dependent nested name specifier. 189 CXXRecordDecl *Sema::getCurrentInstantiationOf(NestedNameSpecifier *NNS) { 190 assert(getLangOptions().CPlusPlus && "Only callable in C++"); 191 assert(NNS->isDependent() && "Only dependent nested-name-specifier allowed"); 192 193 if (!NNS->getAsType()) 194 return 0; 195 196 QualType T = QualType(NNS->getAsType(), 0); 197 return ::getCurrentInstantiationOf(T, CurContext); 198 } 199 200 /// \brief Require that the context specified by SS be complete. 201 /// 202 /// If SS refers to a type, this routine checks whether the type is 203 /// complete enough (or can be made complete enough) for name lookup 204 /// into the DeclContext. A type that is not yet completed can be 205 /// considered "complete enough" if it is a class/struct/union/enum 206 /// that is currently being defined. Or, if we have a type that names 207 /// a class template specialization that is not a complete type, we 208 /// will attempt to instantiate that class template. 209 bool Sema::RequireCompleteDeclContext(CXXScopeSpec &SS, 210 DeclContext *DC) { 211 assert(DC != 0 && "given null context"); 212 213 if (TagDecl *tag = dyn_cast<TagDecl>(DC)) { 214 // If this is a dependent type, then we consider it complete. 215 if (tag->isDependentContext()) 216 return false; 217 218 // If we're currently defining this type, then lookup into the 219 // type is okay: don't complain that it isn't complete yet. 220 QualType type = Context.getTypeDeclType(tag); 221 const TagType *tagType = type->getAs<TagType>(); 222 if (tagType && tagType->isBeingDefined()) 223 return false; 224 225 SourceLocation loc = SS.getLastQualifierNameLoc(); 226 if (loc.isInvalid()) loc = SS.getRange().getBegin(); 227 228 // The type must be complete. 229 if (RequireCompleteType(loc, type, 230 PDiag(diag::err_incomplete_nested_name_spec) 231 << SS.getRange())) { 232 SS.SetInvalid(SS.getRange()); 233 return true; 234 } 235 236 // Fixed enum types are complete, but they aren't valid as scopes 237 // until we see a definition, so awkwardly pull out this special 238 // case. 239 if (const EnumType *enumType = dyn_cast_or_null<EnumType>(tagType)) { 240 if (!enumType->getDecl()->isCompleteDefinition()) { 241 Diag(loc, diag::err_incomplete_nested_name_spec) 242 << type << SS.getRange(); 243 SS.SetInvalid(SS.getRange()); 244 return true; 245 } 246 } 247 } 248 249 return false; 250 } 251 252 bool Sema::ActOnCXXGlobalScopeSpecifier(Scope *S, SourceLocation CCLoc, 253 CXXScopeSpec &SS) { 254 SS.MakeGlobal(Context, CCLoc); 255 return false; 256 } 257 258 /// \brief Determines whether the given declaration is an valid acceptable 259 /// result for name lookup of a nested-name-specifier. 260 bool Sema::isAcceptableNestedNameSpecifier(NamedDecl *SD) { 261 if (!SD) 262 return false; 263 264 // Namespace and namespace aliases are fine. 265 if (isa<NamespaceDecl>(SD) || isa<NamespaceAliasDecl>(SD)) 266 return true; 267 268 if (!isa<TypeDecl>(SD)) 269 return false; 270 271 // Determine whether we have a class (or, in C++11, an enum) or 272 // a typedef thereof. If so, build the nested-name-specifier. 273 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); 274 if (T->isDependentType()) 275 return true; 276 else if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(SD)) { 277 if (TD->getUnderlyingType()->isRecordType() || 278 (Context.getLangOptions().CPlusPlus0x && 279 TD->getUnderlyingType()->isEnumeralType())) 280 return true; 281 } else if (isa<RecordDecl>(SD) || 282 (Context.getLangOptions().CPlusPlus0x && isa<EnumDecl>(SD))) 283 return true; 284 285 return false; 286 } 287 288 /// \brief If the given nested-name-specifier begins with a bare identifier 289 /// (e.g., Base::), perform name lookup for that identifier as a 290 /// nested-name-specifier within the given scope, and return the result of that 291 /// name lookup. 292 NamedDecl *Sema::FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS) { 293 if (!S || !NNS) 294 return 0; 295 296 while (NNS->getPrefix()) 297 NNS = NNS->getPrefix(); 298 299 if (NNS->getKind() != NestedNameSpecifier::Identifier) 300 return 0; 301 302 LookupResult Found(*this, NNS->getAsIdentifier(), SourceLocation(), 303 LookupNestedNameSpecifierName); 304 LookupName(Found, S); 305 assert(!Found.isAmbiguous() && "Cannot handle ambiguities here yet"); 306 307 if (!Found.isSingleResult()) 308 return 0; 309 310 NamedDecl *Result = Found.getFoundDecl(); 311 if (isAcceptableNestedNameSpecifier(Result)) 312 return Result; 313 314 return 0; 315 } 316 317 bool Sema::isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS, 318 SourceLocation IdLoc, 319 IdentifierInfo &II, 320 ParsedType ObjectTypePtr) { 321 QualType ObjectType = GetTypeFromParser(ObjectTypePtr); 322 LookupResult Found(*this, &II, IdLoc, LookupNestedNameSpecifierName); 323 324 // Determine where to perform name lookup 325 DeclContext *LookupCtx = 0; 326 bool isDependent = false; 327 if (!ObjectType.isNull()) { 328 // This nested-name-specifier occurs in a member access expression, e.g., 329 // x->B::f, and we are looking into the type of the object. 330 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); 331 LookupCtx = computeDeclContext(ObjectType); 332 isDependent = ObjectType->isDependentType(); 333 } else if (SS.isSet()) { 334 // This nested-name-specifier occurs after another nested-name-specifier, 335 // so long into the context associated with the prior nested-name-specifier. 336 LookupCtx = computeDeclContext(SS, false); 337 isDependent = isDependentScopeSpecifier(SS); 338 Found.setContextRange(SS.getRange()); 339 } 340 341 if (LookupCtx) { 342 // Perform "qualified" name lookup into the declaration context we 343 // computed, which is either the type of the base of a member access 344 // expression or the declaration context associated with a prior 345 // nested-name-specifier. 346 347 // The declaration context must be complete. 348 if (!LookupCtx->isDependentContext() && 349 RequireCompleteDeclContext(SS, LookupCtx)) 350 return false; 351 352 LookupQualifiedName(Found, LookupCtx); 353 } else if (isDependent) { 354 return false; 355 } else { 356 LookupName(Found, S); 357 } 358 Found.suppressDiagnostics(); 359 360 if (NamedDecl *ND = Found.getAsSingle<NamedDecl>()) 361 return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND); 362 363 return false; 364 } 365 366 /// \brief Build a new nested-name-specifier for "identifier::", as described 367 /// by ActOnCXXNestedNameSpecifier. 368 /// 369 /// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in 370 /// that it contains an extra parameter \p ScopeLookupResult, which provides 371 /// the result of name lookup within the scope of the nested-name-specifier 372 /// that was computed at template definition time. 373 /// 374 /// If ErrorRecoveryLookup is true, then this call is used to improve error 375 /// recovery. This means that it should not emit diagnostics, it should 376 /// just return true on failure. It also means it should only return a valid 377 /// scope if it *knows* that the result is correct. It should not return in a 378 /// dependent context, for example. Nor will it extend \p SS with the scope 379 /// specifier. 380 bool Sema::BuildCXXNestedNameSpecifier(Scope *S, 381 IdentifierInfo &Identifier, 382 SourceLocation IdentifierLoc, 383 SourceLocation CCLoc, 384 QualType ObjectType, 385 bool EnteringContext, 386 CXXScopeSpec &SS, 387 NamedDecl *ScopeLookupResult, 388 bool ErrorRecoveryLookup) { 389 LookupResult Found(*this, &Identifier, IdentifierLoc, 390 LookupNestedNameSpecifierName); 391 392 // Determine where to perform name lookup 393 DeclContext *LookupCtx = 0; 394 bool isDependent = false; 395 if (!ObjectType.isNull()) { 396 // This nested-name-specifier occurs in a member access expression, e.g., 397 // x->B::f, and we are looking into the type of the object. 398 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); 399 LookupCtx = computeDeclContext(ObjectType); 400 isDependent = ObjectType->isDependentType(); 401 } else if (SS.isSet()) { 402 // This nested-name-specifier occurs after another nested-name-specifier, 403 // so look into the context associated with the prior nested-name-specifier. 404 LookupCtx = computeDeclContext(SS, EnteringContext); 405 isDependent = isDependentScopeSpecifier(SS); 406 Found.setContextRange(SS.getRange()); 407 } 408 409 410 bool ObjectTypeSearchedInScope = false; 411 if (LookupCtx) { 412 // Perform "qualified" name lookup into the declaration context we 413 // computed, which is either the type of the base of a member access 414 // expression or the declaration context associated with a prior 415 // nested-name-specifier. 416 417 // The declaration context must be complete. 418 if (!LookupCtx->isDependentContext() && 419 RequireCompleteDeclContext(SS, LookupCtx)) 420 return true; 421 422 LookupQualifiedName(Found, LookupCtx); 423 424 if (!ObjectType.isNull() && Found.empty()) { 425 // C++ [basic.lookup.classref]p4: 426 // If the id-expression in a class member access is a qualified-id of 427 // the form 428 // 429 // class-name-or-namespace-name::... 430 // 431 // the class-name-or-namespace-name following the . or -> operator is 432 // looked up both in the context of the entire postfix-expression and in 433 // the scope of the class of the object expression. If the name is found 434 // only in the scope of the class of the object expression, the name 435 // shall refer to a class-name. If the name is found only in the 436 // context of the entire postfix-expression, the name shall refer to a 437 // class-name or namespace-name. [...] 438 // 439 // Qualified name lookup into a class will not find a namespace-name, 440 // so we do not need to diagnose that case specifically. However, 441 // this qualified name lookup may find nothing. In that case, perform 442 // unqualified name lookup in the given scope (if available) or 443 // reconstruct the result from when name lookup was performed at template 444 // definition time. 445 if (S) 446 LookupName(Found, S); 447 else if (ScopeLookupResult) 448 Found.addDecl(ScopeLookupResult); 449 450 ObjectTypeSearchedInScope = true; 451 } 452 } else if (!isDependent) { 453 // Perform unqualified name lookup in the current scope. 454 LookupName(Found, S); 455 } 456 457 // If we performed lookup into a dependent context and did not find anything, 458 // that's fine: just build a dependent nested-name-specifier. 459 if (Found.empty() && isDependent && 460 !(LookupCtx && LookupCtx->isRecord() && 461 (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() || 462 !cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases()))) { 463 // Don't speculate if we're just trying to improve error recovery. 464 if (ErrorRecoveryLookup) 465 return true; 466 467 // We were not able to compute the declaration context for a dependent 468 // base object type or prior nested-name-specifier, so this 469 // nested-name-specifier refers to an unknown specialization. Just build 470 // a dependent nested-name-specifier. 471 SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc); 472 return false; 473 } 474 475 // FIXME: Deal with ambiguities cleanly. 476 477 if (Found.empty() && !ErrorRecoveryLookup) { 478 // We haven't found anything, and we're not recovering from a 479 // different kind of error, so look for typos. 480 DeclarationName Name = Found.getLookupName(); 481 TypoCorrection Corrected; 482 Found.clear(); 483 if ((Corrected = CorrectTypo(Found.getLookupNameInfo(), 484 Found.getLookupKind(), S, &SS, LookupCtx, 485 EnteringContext, CTC_NoKeywords)) && 486 isAcceptableNestedNameSpecifier(Corrected.getCorrectionDecl())) { 487 std::string CorrectedStr(Corrected.getAsString(getLangOptions())); 488 std::string CorrectedQuotedStr(Corrected.getQuoted(getLangOptions())); 489 if (LookupCtx) 490 Diag(Found.getNameLoc(), diag::err_no_member_suggest) 491 << Name << LookupCtx << CorrectedQuotedStr << SS.getRange() 492 << FixItHint::CreateReplacement(Found.getNameLoc(), CorrectedStr); 493 else 494 Diag(Found.getNameLoc(), diag::err_undeclared_var_use_suggest) 495 << Name << CorrectedQuotedStr 496 << FixItHint::CreateReplacement(Found.getNameLoc(), CorrectedStr); 497 498 if (NamedDecl *ND = Corrected.getCorrectionDecl()) { 499 Diag(ND->getLocation(), diag::note_previous_decl) << CorrectedQuotedStr; 500 Found.addDecl(ND); 501 } 502 Found.setLookupName(Corrected.getCorrection()); 503 } else { 504 Found.setLookupName(&Identifier); 505 } 506 } 507 508 NamedDecl *SD = Found.getAsSingle<NamedDecl>(); 509 if (isAcceptableNestedNameSpecifier(SD)) { 510 if (!ObjectType.isNull() && !ObjectTypeSearchedInScope) { 511 // C++ [basic.lookup.classref]p4: 512 // [...] If the name is found in both contexts, the 513 // class-name-or-namespace-name shall refer to the same entity. 514 // 515 // We already found the name in the scope of the object. Now, look 516 // into the current scope (the scope of the postfix-expression) to 517 // see if we can find the same name there. As above, if there is no 518 // scope, reconstruct the result from the template instantiation itself. 519 NamedDecl *OuterDecl; 520 if (S) { 521 LookupResult FoundOuter(*this, &Identifier, IdentifierLoc, 522 LookupNestedNameSpecifierName); 523 LookupName(FoundOuter, S); 524 OuterDecl = FoundOuter.getAsSingle<NamedDecl>(); 525 } else 526 OuterDecl = ScopeLookupResult; 527 528 if (isAcceptableNestedNameSpecifier(OuterDecl) && 529 OuterDecl->getCanonicalDecl() != SD->getCanonicalDecl() && 530 (!isa<TypeDecl>(OuterDecl) || !isa<TypeDecl>(SD) || 531 !Context.hasSameType( 532 Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)), 533 Context.getTypeDeclType(cast<TypeDecl>(SD))))) { 534 if (ErrorRecoveryLookup) 535 return true; 536 537 Diag(IdentifierLoc, 538 diag::err_nested_name_member_ref_lookup_ambiguous) 539 << &Identifier; 540 Diag(SD->getLocation(), diag::note_ambig_member_ref_object_type) 541 << ObjectType; 542 Diag(OuterDecl->getLocation(), diag::note_ambig_member_ref_scope); 543 544 // Fall through so that we'll pick the name we found in the object 545 // type, since that's probably what the user wanted anyway. 546 } 547 } 548 549 // If we're just performing this lookup for error-recovery purposes, 550 // don't extend the nested-name-specifier. Just return now. 551 if (ErrorRecoveryLookup) 552 return false; 553 554 if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD)) { 555 SS.Extend(Context, Namespace, IdentifierLoc, CCLoc); 556 return false; 557 } 558 559 if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD)) { 560 SS.Extend(Context, Alias, IdentifierLoc, CCLoc); 561 return false; 562 } 563 564 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); 565 TypeLocBuilder TLB; 566 if (isa<InjectedClassNameType>(T)) { 567 InjectedClassNameTypeLoc InjectedTL 568 = TLB.push<InjectedClassNameTypeLoc>(T); 569 InjectedTL.setNameLoc(IdentifierLoc); 570 } else if (isa<RecordType>(T)) { 571 RecordTypeLoc RecordTL = TLB.push<RecordTypeLoc>(T); 572 RecordTL.setNameLoc(IdentifierLoc); 573 } else if (isa<TypedefType>(T)) { 574 TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(T); 575 TypedefTL.setNameLoc(IdentifierLoc); 576 } else if (isa<EnumType>(T)) { 577 EnumTypeLoc EnumTL = TLB.push<EnumTypeLoc>(T); 578 EnumTL.setNameLoc(IdentifierLoc); 579 } else if (isa<TemplateTypeParmType>(T)) { 580 TemplateTypeParmTypeLoc TemplateTypeTL 581 = TLB.push<TemplateTypeParmTypeLoc>(T); 582 TemplateTypeTL.setNameLoc(IdentifierLoc); 583 } else if (isa<UnresolvedUsingType>(T)) { 584 UnresolvedUsingTypeLoc UnresolvedTL 585 = TLB.push<UnresolvedUsingTypeLoc>(T); 586 UnresolvedTL.setNameLoc(IdentifierLoc); 587 } else if (isa<SubstTemplateTypeParmType>(T)) { 588 SubstTemplateTypeParmTypeLoc TL 589 = TLB.push<SubstTemplateTypeParmTypeLoc>(T); 590 TL.setNameLoc(IdentifierLoc); 591 } else if (isa<SubstTemplateTypeParmPackType>(T)) { 592 SubstTemplateTypeParmPackTypeLoc TL 593 = TLB.push<SubstTemplateTypeParmPackTypeLoc>(T); 594 TL.setNameLoc(IdentifierLoc); 595 } else { 596 llvm_unreachable("Unhandled TypeDecl node in nested-name-specifier"); 597 } 598 599 SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T), 600 CCLoc); 601 return false; 602 } 603 604 // Otherwise, we have an error case. If we don't want diagnostics, just 605 // return an error now. 606 if (ErrorRecoveryLookup) 607 return true; 608 609 // If we didn't find anything during our lookup, try again with 610 // ordinary name lookup, which can help us produce better error 611 // messages. 612 if (Found.empty()) { 613 Found.clear(LookupOrdinaryName); 614 LookupName(Found, S); 615 } 616 617 // In Microsoft mode, if we are within a templated function and we can't 618 // resolve Identifier, then extend the SS with Identifier. This will have 619 // the effect of resolving Identifier during template instantiation. 620 // The goal is to be able to resolve a function call whose 621 // nested-name-specifier is located inside a dependent base class. 622 // Example: 623 // 624 // class C { 625 // public: 626 // static void foo2() { } 627 // }; 628 // template <class T> class A { public: typedef C D; }; 629 // 630 // template <class T> class B : public A<T> { 631 // public: 632 // void foo() { D::foo2(); } 633 // }; 634 if (getLangOptions().MicrosoftExt) { 635 DeclContext *DC = LookupCtx ? LookupCtx : CurContext; 636 if (DC->isDependentContext() && DC->isFunctionOrMethod()) { 637 SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc); 638 return false; 639 } 640 } 641 642 unsigned DiagID; 643 if (!Found.empty()) 644 DiagID = diag::err_expected_class_or_namespace; 645 else if (SS.isSet()) { 646 Diag(IdentifierLoc, diag::err_no_member) 647 << &Identifier << LookupCtx << SS.getRange(); 648 return true; 649 } else 650 DiagID = diag::err_undeclared_var_use; 651 652 if (SS.isSet()) 653 Diag(IdentifierLoc, DiagID) << &Identifier << SS.getRange(); 654 else 655 Diag(IdentifierLoc, DiagID) << &Identifier; 656 657 return true; 658 } 659 660 bool Sema::ActOnCXXNestedNameSpecifier(Scope *S, 661 IdentifierInfo &Identifier, 662 SourceLocation IdentifierLoc, 663 SourceLocation CCLoc, 664 ParsedType ObjectType, 665 bool EnteringContext, 666 CXXScopeSpec &SS) { 667 if (SS.isInvalid()) 668 return true; 669 670 return BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, CCLoc, 671 GetTypeFromParser(ObjectType), 672 EnteringContext, SS, 673 /*ScopeLookupResult=*/0, false); 674 } 675 676 /// IsInvalidUnlessNestedName - This method is used for error recovery 677 /// purposes to determine whether the specified identifier is only valid as 678 /// a nested name specifier, for example a namespace name. It is 679 /// conservatively correct to always return false from this method. 680 /// 681 /// The arguments are the same as those passed to ActOnCXXNestedNameSpecifier. 682 bool Sema::IsInvalidUnlessNestedName(Scope *S, CXXScopeSpec &SS, 683 IdentifierInfo &Identifier, 684 SourceLocation IdentifierLoc, 685 SourceLocation ColonLoc, 686 ParsedType ObjectType, 687 bool EnteringContext) { 688 if (SS.isInvalid()) 689 return false; 690 691 return !BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, ColonLoc, 692 GetTypeFromParser(ObjectType), 693 EnteringContext, SS, 694 /*ScopeLookupResult=*/0, true); 695 } 696 697 bool Sema::ActOnCXXNestedNameSpecifier(Scope *S, 698 SourceLocation TemplateLoc, 699 CXXScopeSpec &SS, 700 TemplateTy Template, 701 SourceLocation TemplateNameLoc, 702 SourceLocation LAngleLoc, 703 ASTTemplateArgsPtr TemplateArgsIn, 704 SourceLocation RAngleLoc, 705 SourceLocation CCLoc, 706 bool EnteringContext) { 707 if (SS.isInvalid()) 708 return true; 709 710 // Translate the parser's template argument list in our AST format. 711 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); 712 translateTemplateArguments(TemplateArgsIn, TemplateArgs); 713 714 if (DependentTemplateName *DTN = Template.get().getAsDependentTemplateName()){ 715 // Handle a dependent template specialization for which we cannot resolve 716 // the template name. 717 assert(DTN->getQualifier() 718 == static_cast<NestedNameSpecifier*>(SS.getScopeRep())); 719 QualType T = Context.getDependentTemplateSpecializationType(ETK_None, 720 DTN->getQualifier(), 721 DTN->getIdentifier(), 722 TemplateArgs); 723 724 // Create source-location information for this type. 725 TypeLocBuilder Builder; 726 DependentTemplateSpecializationTypeLoc SpecTL 727 = Builder.push<DependentTemplateSpecializationTypeLoc>(T); 728 SpecTL.setLAngleLoc(LAngleLoc); 729 SpecTL.setRAngleLoc(RAngleLoc); 730 SpecTL.setKeywordLoc(SourceLocation()); 731 SpecTL.setNameLoc(TemplateNameLoc); 732 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context)); 733 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 734 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); 735 736 SS.Extend(Context, TemplateLoc, Builder.getTypeLocInContext(Context, T), 737 CCLoc); 738 return false; 739 } 740 741 742 if (Template.get().getAsOverloadedTemplate() || 743 isa<FunctionTemplateDecl>(Template.get().getAsTemplateDecl())) { 744 SourceRange R(TemplateNameLoc, RAngleLoc); 745 if (SS.getRange().isValid()) 746 R.setBegin(SS.getRange().getBegin()); 747 748 Diag(CCLoc, diag::err_non_type_template_in_nested_name_specifier) 749 << Template.get() << R; 750 NoteAllFoundTemplates(Template.get()); 751 return true; 752 } 753 754 // We were able to resolve the template name to an actual template. 755 // Build an appropriate nested-name-specifier. 756 QualType T = CheckTemplateIdType(Template.get(), TemplateNameLoc, 757 TemplateArgs); 758 if (T.isNull()) 759 return true; 760 761 // Alias template specializations can produce types which are not valid 762 // nested name specifiers. 763 if (!T->isDependentType() && !T->getAs<TagType>()) { 764 Diag(TemplateNameLoc, diag::err_nested_name_spec_non_tag) << T; 765 NoteAllFoundTemplates(Template.get()); 766 return true; 767 } 768 769 // Provide source-location information for the template specialization 770 // type. 771 TypeLocBuilder Builder; 772 TemplateSpecializationTypeLoc SpecTL 773 = Builder.push<TemplateSpecializationTypeLoc>(T); 774 775 SpecTL.setLAngleLoc(LAngleLoc); 776 SpecTL.setRAngleLoc(RAngleLoc); 777 SpecTL.setTemplateNameLoc(TemplateNameLoc); 778 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 779 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); 780 781 782 SS.Extend(Context, TemplateLoc, Builder.getTypeLocInContext(Context, T), 783 CCLoc); 784 return false; 785 } 786 787 namespace { 788 /// \brief A structure that stores a nested-name-specifier annotation, 789 /// including both the nested-name-specifier 790 struct NestedNameSpecifierAnnotation { 791 NestedNameSpecifier *NNS; 792 }; 793 } 794 795 void *Sema::SaveNestedNameSpecifierAnnotation(CXXScopeSpec &SS) { 796 if (SS.isEmpty() || SS.isInvalid()) 797 return 0; 798 799 void *Mem = Context.Allocate((sizeof(NestedNameSpecifierAnnotation) + 800 SS.location_size()), 801 llvm::alignOf<NestedNameSpecifierAnnotation>()); 802 NestedNameSpecifierAnnotation *Annotation 803 = new (Mem) NestedNameSpecifierAnnotation; 804 Annotation->NNS = SS.getScopeRep(); 805 memcpy(Annotation + 1, SS.location_data(), SS.location_size()); 806 return Annotation; 807 } 808 809 void Sema::RestoreNestedNameSpecifierAnnotation(void *AnnotationPtr, 810 SourceRange AnnotationRange, 811 CXXScopeSpec &SS) { 812 if (!AnnotationPtr) { 813 SS.SetInvalid(AnnotationRange); 814 return; 815 } 816 817 NestedNameSpecifierAnnotation *Annotation 818 = static_cast<NestedNameSpecifierAnnotation *>(AnnotationPtr); 819 SS.Adopt(NestedNameSpecifierLoc(Annotation->NNS, Annotation + 1)); 820 } 821 822 bool Sema::ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { 823 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 824 825 NestedNameSpecifier *Qualifier = 826 static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 827 828 // There are only two places a well-formed program may qualify a 829 // declarator: first, when defining a namespace or class member 830 // out-of-line, and second, when naming an explicitly-qualified 831 // friend function. The latter case is governed by 832 // C++03 [basic.lookup.unqual]p10: 833 // In a friend declaration naming a member function, a name used 834 // in the function declarator and not part of a template-argument 835 // in a template-id is first looked up in the scope of the member 836 // function's class. If it is not found, or if the name is part of 837 // a template-argument in a template-id, the look up is as 838 // described for unqualified names in the definition of the class 839 // granting friendship. 840 // i.e. we don't push a scope unless it's a class member. 841 842 switch (Qualifier->getKind()) { 843 case NestedNameSpecifier::Global: 844 case NestedNameSpecifier::Namespace: 845 case NestedNameSpecifier::NamespaceAlias: 846 // These are always namespace scopes. We never want to enter a 847 // namespace scope from anything but a file context. 848 return CurContext->getRedeclContext()->isFileContext(); 849 850 case NestedNameSpecifier::Identifier: 851 case NestedNameSpecifier::TypeSpec: 852 case NestedNameSpecifier::TypeSpecWithTemplate: 853 // These are never namespace scopes. 854 return true; 855 } 856 857 // Silence bogus warning. 858 return false; 859 } 860 861 /// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global 862 /// scope or nested-name-specifier) is parsed, part of a declarator-id. 863 /// After this method is called, according to [C++ 3.4.3p3], names should be 864 /// looked up in the declarator-id's scope, until the declarator is parsed and 865 /// ActOnCXXExitDeclaratorScope is called. 866 /// The 'SS' should be a non-empty valid CXXScopeSpec. 867 bool Sema::ActOnCXXEnterDeclaratorScope(Scope *S, CXXScopeSpec &SS) { 868 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 869 870 if (SS.isInvalid()) return true; 871 872 DeclContext *DC = computeDeclContext(SS, true); 873 if (!DC) return true; 874 875 // Before we enter a declarator's context, we need to make sure that 876 // it is a complete declaration context. 877 if (!DC->isDependentContext() && RequireCompleteDeclContext(SS, DC)) 878 return true; 879 880 EnterDeclaratorContext(S, DC); 881 882 // Rebuild the nested name specifier for the new scope. 883 if (DC->isDependentContext()) 884 RebuildNestedNameSpecifierInCurrentInstantiation(SS); 885 886 return false; 887 } 888 889 /// ActOnCXXExitDeclaratorScope - Called when a declarator that previously 890 /// invoked ActOnCXXEnterDeclaratorScope(), is finished. 'SS' is the same 891 /// CXXScopeSpec that was passed to ActOnCXXEnterDeclaratorScope as well. 892 /// Used to indicate that names should revert to being looked up in the 893 /// defining scope. 894 void Sema::ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { 895 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 896 if (SS.isInvalid()) 897 return; 898 assert(!SS.isInvalid() && computeDeclContext(SS, true) && 899 "exiting declarator scope we never really entered"); 900 ExitDeclaratorContext(S); 901 } 902