SemaCXXScopeSpec.cpp revision 202379
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 "Sema.h" 15#include "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/Parse/DeclSpec.h" 22#include "llvm/ADT/STLExtras.h" 23#include "llvm/Support/raw_ostream.h" 24using namespace clang; 25 26/// \brief Find the current instantiation that associated with the given type. 27static CXXRecordDecl * 28getCurrentInstantiationOf(ASTContext &Context, DeclContext *CurContext, 29 QualType T) { 30 if (T.isNull()) 31 return 0; 32 33 T = Context.getCanonicalType(T); 34 35 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getParent()) { 36 // If we've hit a namespace or the global scope, then the 37 // nested-name-specifier can't refer to the current instantiation. 38 if (Ctx->isFileContext()) 39 return 0; 40 41 // Skip non-class contexts. 42 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx); 43 if (!Record) 44 continue; 45 46 // If this record type is not dependent, 47 if (!Record->isDependentType()) 48 return 0; 49 50 // C++ [temp.dep.type]p1: 51 // 52 // In the definition of a class template, a nested class of a 53 // class template, a member of a class template, or a member of a 54 // nested class of a class template, a name refers to the current 55 // instantiation if it is 56 // -- the injected-class-name (9) of the class template or 57 // nested class, 58 // -- in the definition of a primary class template, the name 59 // of the class template followed by the template argument 60 // list of the primary template (as described below) 61 // enclosed in <>, 62 // -- in the definition of a nested class of a class template, 63 // the name of the nested class referenced as a member of 64 // the current instantiation, or 65 // -- in the definition of a partial specialization, the name 66 // of the class template followed by the template argument 67 // list of the partial specialization enclosed in <>. If 68 // the nth template parameter is a parameter pack, the nth 69 // template argument is a pack expansion (14.6.3) whose 70 // pattern is the name of the parameter pack. 71 // (FIXME: parameter packs) 72 // 73 // All of these options come down to having the 74 // nested-name-specifier type that is equivalent to the 75 // injected-class-name of one of the types that is currently in 76 // our context. 77 if (Context.getCanonicalType(Context.getTypeDeclType(Record)) == T) 78 return Record; 79 80 if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate()) { 81 QualType InjectedClassName 82 = Template->getInjectedClassNameType(Context); 83 if (T == Context.getCanonicalType(InjectedClassName)) 84 return Template->getTemplatedDecl(); 85 } 86 // FIXME: check for class template partial specializations 87 } 88 89 return 0; 90} 91 92/// \brief Compute the DeclContext that is associated with the given type. 93/// 94/// \param T the type for which we are attempting to find a DeclContext. 95/// 96/// \returns the declaration context represented by the type T, 97/// or NULL if the declaration context cannot be computed (e.g., because it is 98/// dependent and not the current instantiation). 99DeclContext *Sema::computeDeclContext(QualType T) { 100 if (const TagType *Tag = T->getAs<TagType>()) 101 return Tag->getDecl(); 102 103 return ::getCurrentInstantiationOf(Context, CurContext, T); 104} 105 106/// \brief Compute the DeclContext that is associated with the given 107/// scope specifier. 108/// 109/// \param SS the C++ scope specifier as it appears in the source 110/// 111/// \param EnteringContext when true, we will be entering the context of 112/// this scope specifier, so we can retrieve the declaration context of a 113/// class template or class template partial specialization even if it is 114/// not the current instantiation. 115/// 116/// \returns the declaration context represented by the scope specifier @p SS, 117/// or NULL if the declaration context cannot be computed (e.g., because it is 118/// dependent and not the current instantiation). 119DeclContext *Sema::computeDeclContext(const CXXScopeSpec &SS, 120 bool EnteringContext) { 121 if (!SS.isSet() || SS.isInvalid()) 122 return 0; 123 124 NestedNameSpecifier *NNS 125 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 126 if (NNS->isDependent()) { 127 // If this nested-name-specifier refers to the current 128 // instantiation, return its DeclContext. 129 if (CXXRecordDecl *Record = getCurrentInstantiationOf(NNS)) 130 return Record; 131 132 if (EnteringContext) { 133 if (const TemplateSpecializationType *SpecType 134 = dyn_cast_or_null<TemplateSpecializationType>(NNS->getAsType())) { 135 // We are entering the context of the nested name specifier, so try to 136 // match the nested name specifier to either a primary class template 137 // or a class template partial specialization. 138 if (ClassTemplateDecl *ClassTemplate 139 = dyn_cast_or_null<ClassTemplateDecl>( 140 SpecType->getTemplateName().getAsTemplateDecl())) { 141 QualType ContextType 142 = Context.getCanonicalType(QualType(SpecType, 0)); 143 144 // If the type of the nested name specifier is the same as the 145 // injected class name of the named class template, we're entering 146 // into that class template definition. 147 QualType Injected = ClassTemplate->getInjectedClassNameType(Context); 148 if (Context.hasSameType(Injected, ContextType)) 149 return ClassTemplate->getTemplatedDecl(); 150 151 // If the type of the nested name specifier is the same as the 152 // type of one of the class template's class template partial 153 // specializations, we're entering into the definition of that 154 // class template partial specialization. 155 if (ClassTemplatePartialSpecializationDecl *PartialSpec 156 = ClassTemplate->findPartialSpecialization(ContextType)) 157 return PartialSpec; 158 } 159 } else if (const RecordType *RecordT 160 = dyn_cast_or_null<RecordType>(NNS->getAsType())) { 161 // The nested name specifier refers to a member of a class template. 162 return RecordT->getDecl(); 163 } 164 } 165 166 return 0; 167 } 168 169 switch (NNS->getKind()) { 170 case NestedNameSpecifier::Identifier: 171 assert(false && "Dependent nested-name-specifier has no DeclContext"); 172 break; 173 174 case NestedNameSpecifier::Namespace: 175 return NNS->getAsNamespace(); 176 177 case NestedNameSpecifier::TypeSpec: 178 case NestedNameSpecifier::TypeSpecWithTemplate: { 179 const TagType *Tag = NNS->getAsType()->getAs<TagType>(); 180 assert(Tag && "Non-tag type in nested-name-specifier"); 181 return Tag->getDecl(); 182 } break; 183 184 case NestedNameSpecifier::Global: 185 return Context.getTranslationUnitDecl(); 186 } 187 188 // Required to silence a GCC warning. 189 return 0; 190} 191 192bool Sema::isDependentScopeSpecifier(const CXXScopeSpec &SS) { 193 if (!SS.isSet() || SS.isInvalid()) 194 return false; 195 196 NestedNameSpecifier *NNS 197 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 198 return NNS->isDependent(); 199} 200 201// \brief Determine whether this C++ scope specifier refers to an 202// unknown specialization, i.e., a dependent type that is not the 203// current instantiation. 204bool Sema::isUnknownSpecialization(const CXXScopeSpec &SS) { 205 if (!isDependentScopeSpecifier(SS)) 206 return false; 207 208 NestedNameSpecifier *NNS 209 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 210 return getCurrentInstantiationOf(NNS) == 0; 211} 212 213/// \brief Determine whether the given scope specifier refers to a 214/// current instantiation that has any dependent base clases. 215/// 216/// This check is typically used when we've performed lookup into the 217/// current instantiation of a template, but that lookup failed. When 218/// there are dependent bases present, however, the lookup needs to be 219/// delayed until template instantiation time. 220bool Sema::isCurrentInstantiationWithDependentBases(const CXXScopeSpec &SS) { 221 if (!SS.isSet()) 222 return false; 223 224 NestedNameSpecifier *NNS = (NestedNameSpecifier*)SS.getScopeRep(); 225 if (!NNS->isDependent()) 226 return false; 227 228 CXXRecordDecl *CurrentInstantiation = getCurrentInstantiationOf(NNS); 229 if (!CurrentInstantiation) 230 return false; 231 232 return CurrentInstantiation->hasAnyDependentBases(); 233} 234 235/// \brief If the given nested name specifier refers to the current 236/// instantiation, return the declaration that corresponds to that 237/// current instantiation (C++0x [temp.dep.type]p1). 238/// 239/// \param NNS a dependent nested name specifier. 240CXXRecordDecl *Sema::getCurrentInstantiationOf(NestedNameSpecifier *NNS) { 241 assert(getLangOptions().CPlusPlus && "Only callable in C++"); 242 assert(NNS->isDependent() && "Only dependent nested-name-specifier allowed"); 243 244 if (!NNS->getAsType()) 245 return 0; 246 247 QualType T = QualType(NNS->getAsType(), 0); 248 return ::getCurrentInstantiationOf(Context, CurContext, T); 249} 250 251/// \brief Require that the context specified by SS be complete. 252/// 253/// If SS refers to a type, this routine checks whether the type is 254/// complete enough (or can be made complete enough) for name lookup 255/// into the DeclContext. A type that is not yet completed can be 256/// considered "complete enough" if it is a class/struct/union/enum 257/// that is currently being defined. Or, if we have a type that names 258/// a class template specialization that is not a complete type, we 259/// will attempt to instantiate that class template. 260bool Sema::RequireCompleteDeclContext(const CXXScopeSpec &SS) { 261 if (!SS.isSet() || SS.isInvalid()) 262 return false; 263 264 DeclContext *DC = computeDeclContext(SS, true); 265 if (TagDecl *Tag = dyn_cast<TagDecl>(DC)) { 266 // If we're currently defining this type, then lookup into the 267 // type is okay: don't complain that it isn't complete yet. 268 const TagType *TagT = Context.getTypeDeclType(Tag)->getAs<TagType>(); 269 if (TagT->isBeingDefined()) 270 return false; 271 272 // The type must be complete. 273 return RequireCompleteType(SS.getRange().getBegin(), 274 Context.getTypeDeclType(Tag), 275 PDiag(diag::err_incomplete_nested_name_spec) 276 << SS.getRange()); 277 } 278 279 return false; 280} 281 282/// ActOnCXXGlobalScopeSpecifier - Return the object that represents the 283/// global scope ('::'). 284Sema::CXXScopeTy *Sema::ActOnCXXGlobalScopeSpecifier(Scope *S, 285 SourceLocation CCLoc) { 286 return NestedNameSpecifier::GlobalSpecifier(Context); 287} 288 289/// \brief Determines whether the given declaration is an valid acceptable 290/// result for name lookup of a nested-name-specifier. 291bool Sema::isAcceptableNestedNameSpecifier(NamedDecl *SD) { 292 if (!SD) 293 return false; 294 295 // Namespace and namespace aliases are fine. 296 if (isa<NamespaceDecl>(SD) || isa<NamespaceAliasDecl>(SD)) 297 return true; 298 299 if (!isa<TypeDecl>(SD)) 300 return false; 301 302 // Determine whether we have a class (or, in C++0x, an enum) or 303 // a typedef thereof. If so, build the nested-name-specifier. 304 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); 305 if (T->isDependentType()) 306 return true; 307 else if (TypedefDecl *TD = dyn_cast<TypedefDecl>(SD)) { 308 if (TD->getUnderlyingType()->isRecordType() || 309 (Context.getLangOptions().CPlusPlus0x && 310 TD->getUnderlyingType()->isEnumeralType())) 311 return true; 312 } else if (isa<RecordDecl>(SD) || 313 (Context.getLangOptions().CPlusPlus0x && isa<EnumDecl>(SD))) 314 return true; 315 316 return false; 317} 318 319/// \brief If the given nested-name-specifier begins with a bare identifier 320/// (e.g., Base::), perform name lookup for that identifier as a 321/// nested-name-specifier within the given scope, and return the result of that 322/// name lookup. 323NamedDecl *Sema::FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS) { 324 if (!S || !NNS) 325 return 0; 326 327 while (NNS->getPrefix()) 328 NNS = NNS->getPrefix(); 329 330 if (NNS->getKind() != NestedNameSpecifier::Identifier) 331 return 0; 332 333 LookupResult Found(*this, NNS->getAsIdentifier(), SourceLocation(), 334 LookupNestedNameSpecifierName); 335 LookupName(Found, S); 336 assert(!Found.isAmbiguous() && "Cannot handle ambiguities here yet"); 337 338 if (!Found.isSingleResult()) 339 return 0; 340 341 NamedDecl *Result = Found.getFoundDecl(); 342 if (isAcceptableNestedNameSpecifier(Result)) 343 return Result; 344 345 return 0; 346} 347 348/// \brief Build a new nested-name-specifier for "identifier::", as described 349/// by ActOnCXXNestedNameSpecifier. 350/// 351/// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in 352/// that it contains an extra parameter \p ScopeLookupResult, which provides 353/// the result of name lookup within the scope of the nested-name-specifier 354/// that was computed at template definition time. 355/// 356/// If ErrorRecoveryLookup is true, then this call is used to improve error 357/// recovery. This means that it should not emit diagnostics, it should 358/// just return null on failure. It also means it should only return a valid 359/// scope if it *knows* that the result is correct. It should not return in a 360/// dependent context, for example. 361Sema::CXXScopeTy *Sema::BuildCXXNestedNameSpecifier(Scope *S, 362 const CXXScopeSpec &SS, 363 SourceLocation IdLoc, 364 SourceLocation CCLoc, 365 IdentifierInfo &II, 366 QualType ObjectType, 367 NamedDecl *ScopeLookupResult, 368 bool EnteringContext, 369 bool ErrorRecoveryLookup) { 370 NestedNameSpecifier *Prefix 371 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 372 373 LookupResult Found(*this, &II, IdLoc, LookupNestedNameSpecifierName); 374 375 // Determine where to perform name lookup 376 DeclContext *LookupCtx = 0; 377 bool isDependent = false; 378 if (!ObjectType.isNull()) { 379 // This nested-name-specifier occurs in a member access expression, e.g., 380 // x->B::f, and we are looking into the type of the object. 381 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); 382 LookupCtx = computeDeclContext(ObjectType); 383 isDependent = ObjectType->isDependentType(); 384 } else if (SS.isSet()) { 385 // This nested-name-specifier occurs after another nested-name-specifier, 386 // so long into the context associated with the prior nested-name-specifier. 387 LookupCtx = computeDeclContext(SS, EnteringContext); 388 isDependent = isDependentScopeSpecifier(SS); 389 Found.setContextRange(SS.getRange()); 390 } 391 392 393 bool ObjectTypeSearchedInScope = false; 394 if (LookupCtx) { 395 // Perform "qualified" name lookup into the declaration context we 396 // computed, which is either the type of the base of a member access 397 // expression or the declaration context associated with a prior 398 // nested-name-specifier. 399 400 // The declaration context must be complete. 401 if (!LookupCtx->isDependentContext() && RequireCompleteDeclContext(SS)) 402 return 0; 403 404 LookupQualifiedName(Found, LookupCtx); 405 406 if (!ObjectType.isNull() && Found.empty()) { 407 // C++ [basic.lookup.classref]p4: 408 // If the id-expression in a class member access is a qualified-id of 409 // the form 410 // 411 // class-name-or-namespace-name::... 412 // 413 // the class-name-or-namespace-name following the . or -> operator is 414 // looked up both in the context of the entire postfix-expression and in 415 // the scope of the class of the object expression. If the name is found 416 // only in the scope of the class of the object expression, the name 417 // shall refer to a class-name. If the name is found only in the 418 // context of the entire postfix-expression, the name shall refer to a 419 // class-name or namespace-name. [...] 420 // 421 // Qualified name lookup into a class will not find a namespace-name, 422 // so we do not need to diagnoste that case specifically. However, 423 // this qualified name lookup may find nothing. In that case, perform 424 // unqualified name lookup in the given scope (if available) or 425 // reconstruct the result from when name lookup was performed at template 426 // definition time. 427 if (S) 428 LookupName(Found, S); 429 else if (ScopeLookupResult) 430 Found.addDecl(ScopeLookupResult); 431 432 ObjectTypeSearchedInScope = true; 433 } 434 } else if (isDependent) { 435 // Don't speculate if we're just trying to improve error recovery. 436 if (ErrorRecoveryLookup) 437 return 0; 438 439 // We were not able to compute the declaration context for a dependent 440 // base object type or prior nested-name-specifier, so this 441 // nested-name-specifier refers to an unknown specialization. Just build 442 // a dependent nested-name-specifier. 443 if (!Prefix) 444 return NestedNameSpecifier::Create(Context, &II); 445 446 return NestedNameSpecifier::Create(Context, Prefix, &II); 447 } else { 448 // Perform unqualified name lookup in the current scope. 449 LookupName(Found, S); 450 } 451 452 // FIXME: Deal with ambiguities cleanly. 453 454 if (Found.empty() && !ErrorRecoveryLookup) { 455 // We haven't found anything, and we're not recovering from a 456 // different kind of error, so look for typos. 457 DeclarationName Name = Found.getLookupName(); 458 if (CorrectTypo(Found, S, &SS, LookupCtx, EnteringContext) && 459 Found.isSingleResult() && 460 isAcceptableNestedNameSpecifier(Found.getAsSingle<NamedDecl>())) { 461 if (LookupCtx) 462 Diag(Found.getNameLoc(), diag::err_no_member_suggest) 463 << Name << LookupCtx << Found.getLookupName() << SS.getRange() 464 << CodeModificationHint::CreateReplacement(Found.getNameLoc(), 465 Found.getLookupName().getAsString()); 466 else 467 Diag(Found.getNameLoc(), diag::err_undeclared_var_use_suggest) 468 << Name << Found.getLookupName() 469 << CodeModificationHint::CreateReplacement(Found.getNameLoc(), 470 Found.getLookupName().getAsString()); 471 472 if (NamedDecl *ND = Found.getAsSingle<NamedDecl>()) 473 Diag(ND->getLocation(), diag::note_previous_decl) 474 << ND->getDeclName(); 475 } else 476 Found.clear(); 477 } 478 479 NamedDecl *SD = Found.getAsSingle<NamedDecl>(); 480 if (isAcceptableNestedNameSpecifier(SD)) { 481 if (!ObjectType.isNull() && !ObjectTypeSearchedInScope) { 482 // C++ [basic.lookup.classref]p4: 483 // [...] If the name is found in both contexts, the 484 // class-name-or-namespace-name shall refer to the same entity. 485 // 486 // We already found the name in the scope of the object. Now, look 487 // into the current scope (the scope of the postfix-expression) to 488 // see if we can find the same name there. As above, if there is no 489 // scope, reconstruct the result from the template instantiation itself. 490 NamedDecl *OuterDecl; 491 if (S) { 492 LookupResult FoundOuter(*this, &II, IdLoc, LookupNestedNameSpecifierName); 493 LookupName(FoundOuter, S); 494 OuterDecl = FoundOuter.getAsSingle<NamedDecl>(); 495 } else 496 OuterDecl = ScopeLookupResult; 497 498 if (isAcceptableNestedNameSpecifier(OuterDecl) && 499 OuterDecl->getCanonicalDecl() != SD->getCanonicalDecl() && 500 (!isa<TypeDecl>(OuterDecl) || !isa<TypeDecl>(SD) || 501 !Context.hasSameType( 502 Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)), 503 Context.getTypeDeclType(cast<TypeDecl>(SD))))) { 504 if (ErrorRecoveryLookup) 505 return 0; 506 507 Diag(IdLoc, diag::err_nested_name_member_ref_lookup_ambiguous) 508 << &II; 509 Diag(SD->getLocation(), diag::note_ambig_member_ref_object_type) 510 << ObjectType; 511 Diag(OuterDecl->getLocation(), diag::note_ambig_member_ref_scope); 512 513 // Fall through so that we'll pick the name we found in the object 514 // type, since that's probably what the user wanted anyway. 515 } 516 } 517 518 if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD)) 519 return NestedNameSpecifier::Create(Context, Prefix, Namespace); 520 521 // FIXME: It would be nice to maintain the namespace alias name, then 522 // see through that alias when resolving the nested-name-specifier down to 523 // a declaration context. 524 if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD)) 525 return NestedNameSpecifier::Create(Context, Prefix, 526 527 Alias->getNamespace()); 528 529 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); 530 return NestedNameSpecifier::Create(Context, Prefix, false, 531 T.getTypePtr()); 532 } 533 534 // Otherwise, we have an error case. If we don't want diagnostics, just 535 // return an error now. 536 if (ErrorRecoveryLookup) 537 return 0; 538 539 // If we didn't find anything during our lookup, try again with 540 // ordinary name lookup, which can help us produce better error 541 // messages. 542 if (Found.empty()) { 543 Found.clear(LookupOrdinaryName); 544 LookupName(Found, S); 545 } 546 547 unsigned DiagID; 548 if (!Found.empty()) 549 DiagID = diag::err_expected_class_or_namespace; 550 else if (SS.isSet()) { 551 Diag(IdLoc, diag::err_no_member) << &II << LookupCtx << SS.getRange(); 552 return 0; 553 } else 554 DiagID = diag::err_undeclared_var_use; 555 556 if (SS.isSet()) 557 Diag(IdLoc, DiagID) << &II << SS.getRange(); 558 else 559 Diag(IdLoc, DiagID) << &II; 560 561 return 0; 562} 563 564/// ActOnCXXNestedNameSpecifier - Called during parsing of a 565/// nested-name-specifier. e.g. for "foo::bar::" we parsed "foo::" and now 566/// we want to resolve "bar::". 'SS' is empty or the previously parsed 567/// nested-name part ("foo::"), 'IdLoc' is the source location of 'bar', 568/// 'CCLoc' is the location of '::' and 'II' is the identifier for 'bar'. 569/// Returns a CXXScopeTy* object representing the C++ scope. 570Sema::CXXScopeTy *Sema::ActOnCXXNestedNameSpecifier(Scope *S, 571 const CXXScopeSpec &SS, 572 SourceLocation IdLoc, 573 SourceLocation CCLoc, 574 IdentifierInfo &II, 575 TypeTy *ObjectTypePtr, 576 bool EnteringContext) { 577 return BuildCXXNestedNameSpecifier(S, SS, IdLoc, CCLoc, II, 578 QualType::getFromOpaquePtr(ObjectTypePtr), 579 /*ScopeLookupResult=*/0, EnteringContext, 580 false); 581} 582 583/// IsInvalidUnlessNestedName - This method is used for error recovery 584/// purposes to determine whether the specified identifier is only valid as 585/// a nested name specifier, for example a namespace name. It is 586/// conservatively correct to always return false from this method. 587/// 588/// The arguments are the same as those passed to ActOnCXXNestedNameSpecifier. 589bool Sema::IsInvalidUnlessNestedName(Scope *S, const CXXScopeSpec &SS, 590 IdentifierInfo &II, TypeTy *ObjectType, 591 bool EnteringContext) { 592 return BuildCXXNestedNameSpecifier(S, SS, SourceLocation(), SourceLocation(), 593 II, QualType::getFromOpaquePtr(ObjectType), 594 /*ScopeLookupResult=*/0, EnteringContext, 595 true); 596} 597 598Sema::CXXScopeTy *Sema::ActOnCXXNestedNameSpecifier(Scope *S, 599 const CXXScopeSpec &SS, 600 TypeTy *Ty, 601 SourceRange TypeRange, 602 SourceLocation CCLoc) { 603 NestedNameSpecifier *Prefix 604 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 605 QualType T = GetTypeFromParser(Ty); 606 return NestedNameSpecifier::Create(Context, Prefix, /*FIXME:*/false, 607 T.getTypePtr()); 608} 609 610bool Sema::ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { 611 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 612 613 NestedNameSpecifier *Qualifier = 614 static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 615 616 // There are only two places a well-formed program may qualify a 617 // declarator: first, when defining a namespace or class member 618 // out-of-line, and second, when naming an explicitly-qualified 619 // friend function. The latter case is governed by 620 // C++03 [basic.lookup.unqual]p10: 621 // In a friend declaration naming a member function, a name used 622 // in the function declarator and not part of a template-argument 623 // in a template-id is first looked up in the scope of the member 624 // function's class. If it is not found, or if the name is part of 625 // a template-argument in a template-id, the look up is as 626 // described for unqualified names in the definition of the class 627 // granting friendship. 628 // i.e. we don't push a scope unless it's a class member. 629 630 switch (Qualifier->getKind()) { 631 case NestedNameSpecifier::Global: 632 case NestedNameSpecifier::Namespace: 633 // These are always namespace scopes. We never want to enter a 634 // namespace scope from anything but a file context. 635 return CurContext->getLookupContext()->isFileContext(); 636 637 case NestedNameSpecifier::Identifier: 638 case NestedNameSpecifier::TypeSpec: 639 case NestedNameSpecifier::TypeSpecWithTemplate: 640 // These are never namespace scopes. 641 return true; 642 } 643 644 // Silence bogus warning. 645 return false; 646} 647 648/// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global 649/// scope or nested-name-specifier) is parsed, part of a declarator-id. 650/// After this method is called, according to [C++ 3.4.3p3], names should be 651/// looked up in the declarator-id's scope, until the declarator is parsed and 652/// ActOnCXXExitDeclaratorScope is called. 653/// The 'SS' should be a non-empty valid CXXScopeSpec. 654bool Sema::ActOnCXXEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { 655 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 656 657 if (SS.isInvalid()) return true; 658 659 DeclContext *DC = computeDeclContext(SS, true); 660 if (!DC) return true; 661 662 // Before we enter a declarator's context, we need to make sure that 663 // it is a complete declaration context. 664 if (!DC->isDependentContext() && RequireCompleteDeclContext(SS)) 665 return true; 666 667 EnterDeclaratorContext(S, DC); 668 return false; 669} 670 671/// ActOnCXXExitDeclaratorScope - Called when a declarator that previously 672/// invoked ActOnCXXEnterDeclaratorScope(), is finished. 'SS' is the same 673/// CXXScopeSpec that was passed to ActOnCXXEnterDeclaratorScope as well. 674/// Used to indicate that names should revert to being looked up in the 675/// defining scope. 676void Sema::ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { 677 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 678 if (SS.isInvalid()) 679 return; 680 assert(!SS.isInvalid() && computeDeclContext(SS, true) && 681 "exiting declarator scope we never really entered"); 682 ExitDeclaratorContext(S); 683} 684