SemaCXXScopeSpec.cpp revision a4e8c2a65a985782344a818d356c40d117fc4f12
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).getUnqualifiedType(); 34 35 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) { 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 If the given nested name specifier refers to the current 214/// instantiation, return the declaration that corresponds to that 215/// current instantiation (C++0x [temp.dep.type]p1). 216/// 217/// \param NNS a dependent nested name specifier. 218CXXRecordDecl *Sema::getCurrentInstantiationOf(NestedNameSpecifier *NNS) { 219 assert(getLangOptions().CPlusPlus && "Only callable in C++"); 220 assert(NNS->isDependent() && "Only dependent nested-name-specifier allowed"); 221 222 if (!NNS->getAsType()) 223 return 0; 224 225 QualType T = QualType(NNS->getAsType(), 0); 226 return ::getCurrentInstantiationOf(Context, CurContext, T); 227} 228 229/// \brief Require that the context specified by SS be complete. 230/// 231/// If SS refers to a type, this routine checks whether the type is 232/// complete enough (or can be made complete enough) for name lookup 233/// into the DeclContext. A type that is not yet completed can be 234/// considered "complete enough" if it is a class/struct/union/enum 235/// that is currently being defined. Or, if we have a type that names 236/// a class template specialization that is not a complete type, we 237/// will attempt to instantiate that class template. 238bool Sema::RequireCompleteDeclContext(const CXXScopeSpec &SS) { 239 if (!SS.isSet() || SS.isInvalid()) 240 return false; 241 242 DeclContext *DC = computeDeclContext(SS, true); 243 if (TagDecl *Tag = dyn_cast<TagDecl>(DC)) { 244 // If this is a dependent type, then we consider it complete. 245 if (Tag->isDependentContext()) 246 return false; 247 248 // If we're currently defining this type, then lookup into the 249 // type is okay: don't complain that it isn't complete yet. 250 const TagType *TagT = Context.getTypeDeclType(Tag)->getAs<TagType>(); 251 if (TagT->isBeingDefined()) 252 return false; 253 254 // The type must be complete. 255 return RequireCompleteType(SS.getRange().getBegin(), 256 Context.getTypeDeclType(Tag), 257 PDiag(diag::err_incomplete_nested_name_spec) 258 << SS.getRange()); 259 } 260 261 return false; 262} 263 264/// ActOnCXXGlobalScopeSpecifier - Return the object that represents the 265/// global scope ('::'). 266Sema::CXXScopeTy *Sema::ActOnCXXGlobalScopeSpecifier(Scope *S, 267 SourceLocation CCLoc) { 268 return NestedNameSpecifier::GlobalSpecifier(Context); 269} 270 271/// \brief Determines whether the given declaration is an valid acceptable 272/// result for name lookup of a nested-name-specifier. 273bool Sema::isAcceptableNestedNameSpecifier(NamedDecl *SD) { 274 if (!SD) 275 return false; 276 277 // Namespace and namespace aliases are fine. 278 if (isa<NamespaceDecl>(SD) || isa<NamespaceAliasDecl>(SD)) 279 return true; 280 281 if (!isa<TypeDecl>(SD)) 282 return false; 283 284 // Determine whether we have a class (or, in C++0x, an enum) or 285 // a typedef thereof. If so, build the nested-name-specifier. 286 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); 287 if (T->isDependentType()) 288 return true; 289 else if (TypedefDecl *TD = dyn_cast<TypedefDecl>(SD)) { 290 if (TD->getUnderlyingType()->isRecordType() || 291 (Context.getLangOptions().CPlusPlus0x && 292 TD->getUnderlyingType()->isEnumeralType())) 293 return true; 294 } else if (isa<RecordDecl>(SD) || 295 (Context.getLangOptions().CPlusPlus0x && isa<EnumDecl>(SD))) 296 return true; 297 298 return false; 299} 300 301/// \brief If the given nested-name-specifier begins with a bare identifier 302/// (e.g., Base::), perform name lookup for that identifier as a 303/// nested-name-specifier within the given scope, and return the result of that 304/// name lookup. 305NamedDecl *Sema::FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS) { 306 if (!S || !NNS) 307 return 0; 308 309 while (NNS->getPrefix()) 310 NNS = NNS->getPrefix(); 311 312 if (NNS->getKind() != NestedNameSpecifier::Identifier) 313 return 0; 314 315 LookupResult Found(*this, NNS->getAsIdentifier(), SourceLocation(), 316 LookupNestedNameSpecifierName); 317 LookupName(Found, S); 318 assert(!Found.isAmbiguous() && "Cannot handle ambiguities here yet"); 319 320 if (!Found.isSingleResult()) 321 return 0; 322 323 NamedDecl *Result = Found.getFoundDecl(); 324 if (isAcceptableNestedNameSpecifier(Result)) 325 return Result; 326 327 return 0; 328} 329 330/// \brief Build a new nested-name-specifier for "identifier::", as described 331/// by ActOnCXXNestedNameSpecifier. 332/// 333/// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in 334/// that it contains an extra parameter \p ScopeLookupResult, which provides 335/// the result of name lookup within the scope of the nested-name-specifier 336/// that was computed at template definition time. 337/// 338/// If ErrorRecoveryLookup is true, then this call is used to improve error 339/// recovery. This means that it should not emit diagnostics, it should 340/// just return null on failure. It also means it should only return a valid 341/// scope if it *knows* that the result is correct. It should not return in a 342/// dependent context, for example. 343Sema::CXXScopeTy *Sema::BuildCXXNestedNameSpecifier(Scope *S, 344 const CXXScopeSpec &SS, 345 SourceLocation IdLoc, 346 SourceLocation CCLoc, 347 IdentifierInfo &II, 348 QualType ObjectType, 349 NamedDecl *ScopeLookupResult, 350 bool EnteringContext, 351 bool ErrorRecoveryLookup) { 352 NestedNameSpecifier *Prefix 353 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 354 355 LookupResult Found(*this, &II, IdLoc, LookupNestedNameSpecifierName); 356 357 // Determine where to perform name lookup 358 DeclContext *LookupCtx = 0; 359 bool isDependent = false; 360 if (!ObjectType.isNull()) { 361 // This nested-name-specifier occurs in a member access expression, e.g., 362 // x->B::f, and we are looking into the type of the object. 363 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); 364 LookupCtx = computeDeclContext(ObjectType); 365 isDependent = ObjectType->isDependentType(); 366 } else if (SS.isSet()) { 367 // This nested-name-specifier occurs after another nested-name-specifier, 368 // so long into the context associated with the prior nested-name-specifier. 369 LookupCtx = computeDeclContext(SS, EnteringContext); 370 isDependent = isDependentScopeSpecifier(SS); 371 Found.setContextRange(SS.getRange()); 372 } 373 374 375 bool ObjectTypeSearchedInScope = false; 376 if (LookupCtx) { 377 // Perform "qualified" name lookup into the declaration context we 378 // computed, which is either the type of the base of a member access 379 // expression or the declaration context associated with a prior 380 // nested-name-specifier. 381 382 // The declaration context must be complete. 383 if (!LookupCtx->isDependentContext() && RequireCompleteDeclContext(SS)) 384 return 0; 385 386 LookupQualifiedName(Found, LookupCtx); 387 388 if (!ObjectType.isNull() && Found.empty()) { 389 // C++ [basic.lookup.classref]p4: 390 // If the id-expression in a class member access is a qualified-id of 391 // the form 392 // 393 // class-name-or-namespace-name::... 394 // 395 // the class-name-or-namespace-name following the . or -> operator is 396 // looked up both in the context of the entire postfix-expression and in 397 // the scope of the class of the object expression. If the name is found 398 // only in the scope of the class of the object expression, the name 399 // shall refer to a class-name. If the name is found only in the 400 // context of the entire postfix-expression, the name shall refer to a 401 // class-name or namespace-name. [...] 402 // 403 // Qualified name lookup into a class will not find a namespace-name, 404 // so we do not need to diagnoste that case specifically. However, 405 // this qualified name lookup may find nothing. In that case, perform 406 // unqualified name lookup in the given scope (if available) or 407 // reconstruct the result from when name lookup was performed at template 408 // definition time. 409 if (S) 410 LookupName(Found, S); 411 else if (ScopeLookupResult) 412 Found.addDecl(ScopeLookupResult); 413 414 ObjectTypeSearchedInScope = true; 415 } 416 } else if (isDependent) { 417 // Don't speculate if we're just trying to improve error recovery. 418 if (ErrorRecoveryLookup) 419 return 0; 420 421 // We were not able to compute the declaration context for a dependent 422 // base object type or prior nested-name-specifier, so this 423 // nested-name-specifier refers to an unknown specialization. Just build 424 // a dependent nested-name-specifier. 425 if (!Prefix) 426 return NestedNameSpecifier::Create(Context, &II); 427 428 return NestedNameSpecifier::Create(Context, Prefix, &II); 429 } else { 430 // Perform unqualified name lookup in the current scope. 431 LookupName(Found, S); 432 } 433 434 // FIXME: Deal with ambiguities cleanly. 435 436 if (Found.empty() && !ErrorRecoveryLookup) { 437 // We haven't found anything, and we're not recovering from a 438 // different kind of error, so look for typos. 439 DeclarationName Name = Found.getLookupName(); 440 if (CorrectTypo(Found, S, &SS, LookupCtx, EnteringContext) && 441 Found.isSingleResult() && 442 isAcceptableNestedNameSpecifier(Found.getAsSingle<NamedDecl>())) { 443 if (LookupCtx) 444 Diag(Found.getNameLoc(), diag::err_no_member_suggest) 445 << Name << LookupCtx << Found.getLookupName() << SS.getRange() 446 << CodeModificationHint::CreateReplacement(Found.getNameLoc(), 447 Found.getLookupName().getAsString()); 448 else 449 Diag(Found.getNameLoc(), diag::err_undeclared_var_use_suggest) 450 << Name << Found.getLookupName() 451 << CodeModificationHint::CreateReplacement(Found.getNameLoc(), 452 Found.getLookupName().getAsString()); 453 454 if (NamedDecl *ND = Found.getAsSingle<NamedDecl>()) 455 Diag(ND->getLocation(), diag::note_previous_decl) 456 << ND->getDeclName(); 457 } else 458 Found.clear(); 459 } 460 461 NamedDecl *SD = Found.getAsSingle<NamedDecl>(); 462 if (isAcceptableNestedNameSpecifier(SD)) { 463 if (!ObjectType.isNull() && !ObjectTypeSearchedInScope) { 464 // C++ [basic.lookup.classref]p4: 465 // [...] If the name is found in both contexts, the 466 // class-name-or-namespace-name shall refer to the same entity. 467 // 468 // We already found the name in the scope of the object. Now, look 469 // into the current scope (the scope of the postfix-expression) to 470 // see if we can find the same name there. As above, if there is no 471 // scope, reconstruct the result from the template instantiation itself. 472 NamedDecl *OuterDecl; 473 if (S) { 474 LookupResult FoundOuter(*this, &II, IdLoc, LookupNestedNameSpecifierName); 475 LookupName(FoundOuter, S); 476 OuterDecl = FoundOuter.getAsSingle<NamedDecl>(); 477 } else 478 OuterDecl = ScopeLookupResult; 479 480 if (isAcceptableNestedNameSpecifier(OuterDecl) && 481 OuterDecl->getCanonicalDecl() != SD->getCanonicalDecl() && 482 (!isa<TypeDecl>(OuterDecl) || !isa<TypeDecl>(SD) || 483 !Context.hasSameType( 484 Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)), 485 Context.getTypeDeclType(cast<TypeDecl>(SD))))) { 486 if (ErrorRecoveryLookup) 487 return 0; 488 489 Diag(IdLoc, diag::err_nested_name_member_ref_lookup_ambiguous) 490 << &II; 491 Diag(SD->getLocation(), diag::note_ambig_member_ref_object_type) 492 << ObjectType; 493 Diag(OuterDecl->getLocation(), diag::note_ambig_member_ref_scope); 494 495 // Fall through so that we'll pick the name we found in the object 496 // type, since that's probably what the user wanted anyway. 497 } 498 } 499 500 if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD)) 501 return NestedNameSpecifier::Create(Context, Prefix, Namespace); 502 503 // FIXME: It would be nice to maintain the namespace alias name, then 504 // see through that alias when resolving the nested-name-specifier down to 505 // a declaration context. 506 if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD)) 507 return NestedNameSpecifier::Create(Context, Prefix, 508 509 Alias->getNamespace()); 510 511 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); 512 return NestedNameSpecifier::Create(Context, Prefix, false, 513 T.getTypePtr()); 514 } 515 516 // Otherwise, we have an error case. If we don't want diagnostics, just 517 // return an error now. 518 if (ErrorRecoveryLookup) 519 return 0; 520 521 // If we didn't find anything during our lookup, try again with 522 // ordinary name lookup, which can help us produce better error 523 // messages. 524 if (Found.empty()) { 525 Found.clear(LookupOrdinaryName); 526 LookupName(Found, S); 527 } 528 529 unsigned DiagID; 530 if (!Found.empty()) 531 DiagID = diag::err_expected_class_or_namespace; 532 else if (SS.isSet()) { 533 Diag(IdLoc, diag::err_no_member) << &II << LookupCtx << SS.getRange(); 534 return 0; 535 } else 536 DiagID = diag::err_undeclared_var_use; 537 538 if (SS.isSet()) 539 Diag(IdLoc, DiagID) << &II << SS.getRange(); 540 else 541 Diag(IdLoc, DiagID) << &II; 542 543 return 0; 544} 545 546/// ActOnCXXNestedNameSpecifier - Called during parsing of a 547/// nested-name-specifier. e.g. for "foo::bar::" we parsed "foo::" and now 548/// we want to resolve "bar::". 'SS' is empty or the previously parsed 549/// nested-name part ("foo::"), 'IdLoc' is the source location of 'bar', 550/// 'CCLoc' is the location of '::' and 'II' is the identifier for 'bar'. 551/// Returns a CXXScopeTy* object representing the C++ scope. 552Sema::CXXScopeTy *Sema::ActOnCXXNestedNameSpecifier(Scope *S, 553 const CXXScopeSpec &SS, 554 SourceLocation IdLoc, 555 SourceLocation CCLoc, 556 IdentifierInfo &II, 557 TypeTy *ObjectTypePtr, 558 bool EnteringContext) { 559 return BuildCXXNestedNameSpecifier(S, SS, IdLoc, CCLoc, II, 560 QualType::getFromOpaquePtr(ObjectTypePtr), 561 /*ScopeLookupResult=*/0, EnteringContext, 562 false); 563} 564 565/// IsInvalidUnlessNestedName - This method is used for error recovery 566/// purposes to determine whether the specified identifier is only valid as 567/// a nested name specifier, for example a namespace name. It is 568/// conservatively correct to always return false from this method. 569/// 570/// The arguments are the same as those passed to ActOnCXXNestedNameSpecifier. 571bool Sema::IsInvalidUnlessNestedName(Scope *S, const CXXScopeSpec &SS, 572 IdentifierInfo &II, TypeTy *ObjectType, 573 bool EnteringContext) { 574 return BuildCXXNestedNameSpecifier(S, SS, SourceLocation(), SourceLocation(), 575 II, QualType::getFromOpaquePtr(ObjectType), 576 /*ScopeLookupResult=*/0, EnteringContext, 577 true); 578} 579 580Sema::CXXScopeTy *Sema::ActOnCXXNestedNameSpecifier(Scope *S, 581 const CXXScopeSpec &SS, 582 TypeTy *Ty, 583 SourceRange TypeRange, 584 SourceLocation CCLoc) { 585 NestedNameSpecifier *Prefix 586 = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); 587 QualType T = GetTypeFromParser(Ty); 588 return NestedNameSpecifier::Create(Context, Prefix, /*FIXME:*/false, 589 T.getTypePtr()); 590} 591 592bool Sema::ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { 593 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 594 595 NestedNameSpecifier *Qualifier = 596 static_cast<NestedNameSpecifier*>(SS.getScopeRep()); 597 598 // There are only two places a well-formed program may qualify a 599 // declarator: first, when defining a namespace or class member 600 // out-of-line, and second, when naming an explicitly-qualified 601 // friend function. The latter case is governed by 602 // C++03 [basic.lookup.unqual]p10: 603 // In a friend declaration naming a member function, a name used 604 // in the function declarator and not part of a template-argument 605 // in a template-id is first looked up in the scope of the member 606 // function's class. If it is not found, or if the name is part of 607 // a template-argument in a template-id, the look up is as 608 // described for unqualified names in the definition of the class 609 // granting friendship. 610 // i.e. we don't push a scope unless it's a class member. 611 612 switch (Qualifier->getKind()) { 613 case NestedNameSpecifier::Global: 614 case NestedNameSpecifier::Namespace: 615 // These are always namespace scopes. We never want to enter a 616 // namespace scope from anything but a file context. 617 return CurContext->getLookupContext()->isFileContext(); 618 619 case NestedNameSpecifier::Identifier: 620 case NestedNameSpecifier::TypeSpec: 621 case NestedNameSpecifier::TypeSpecWithTemplate: 622 // These are never namespace scopes. 623 return true; 624 } 625 626 // Silence bogus warning. 627 return false; 628} 629 630/// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global 631/// scope or nested-name-specifier) is parsed, part of a declarator-id. 632/// After this method is called, according to [C++ 3.4.3p3], names should be 633/// looked up in the declarator-id's scope, until the declarator is parsed and 634/// ActOnCXXExitDeclaratorScope is called. 635/// The 'SS' should be a non-empty valid CXXScopeSpec. 636bool Sema::ActOnCXXEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { 637 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 638 639 if (SS.isInvalid()) return true; 640 641 DeclContext *DC = computeDeclContext(SS, true); 642 if (!DC) return true; 643 644 // Before we enter a declarator's context, we need to make sure that 645 // it is a complete declaration context. 646 if (!DC->isDependentContext() && RequireCompleteDeclContext(SS)) 647 return true; 648 649 EnterDeclaratorContext(S, DC); 650 return false; 651} 652 653/// ActOnCXXExitDeclaratorScope - Called when a declarator that previously 654/// invoked ActOnCXXEnterDeclaratorScope(), is finished. 'SS' is the same 655/// CXXScopeSpec that was passed to ActOnCXXEnterDeclaratorScope as well. 656/// Used to indicate that names should revert to being looked up in the 657/// defining scope. 658void Sema::ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { 659 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); 660 if (SS.isInvalid()) 661 return; 662 assert(!SS.isInvalid() && computeDeclContext(SS, true) && 663 "exiting declarator scope we never really entered"); 664 ExitDeclaratorContext(S); 665} 666