blob: 1ad50434dbb89982255b7c340e4a1cb58c70d811 [file] [log] [blame]
Cedric Venet3d658642009-02-14 20:20:19 +00001//===--- 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
John McCall2d887082010-08-25 22:03:47 +000014#include "clang/Sema/SemaInternal.h"
Douglas Gregore737f502010-08-12 20:07:10 +000015#include "clang/Sema/Lookup.h"
Cedric Venet3d658642009-02-14 20:20:19 +000016#include "clang/AST/ASTContext.h"
Douglas Gregor42af25f2009-05-11 19:58:34 +000017#include "clang/AST/DeclTemplate.h"
Douglas Gregorfe85ced2009-08-06 03:17:00 +000018#include "clang/AST/ExprCXX.h"
Douglas Gregore4e5b052009-03-19 00:18:19 +000019#include "clang/AST/NestedNameSpecifier.h"
Anders Carlssonb7906612009-08-26 23:45:07 +000020#include "clang/Basic/PartialDiagnostic.h"
John McCall19510852010-08-20 18:27:03 +000021#include "clang/Sema/DeclSpec.h"
Douglas Gregor2e4c34a2011-02-24 00:17:56 +000022#include "TypeLocBuilder.h"
Cedric Venet3d658642009-02-14 20:20:19 +000023#include "llvm/ADT/STLExtras.h"
Douglas Gregor7551c182009-07-22 00:28:09 +000024#include "llvm/Support/raw_ostream.h"
Cedric Venet3d658642009-02-14 20:20:19 +000025using namespace clang;
26
Douglas Gregor43d88632009-11-04 22:49:18 +000027/// \brief Find the current instantiation that associated with the given type.
Douglas Gregord9ea1802011-02-19 19:24:40 +000028static CXXRecordDecl *getCurrentInstantiationOf(QualType T,
29 DeclContext *CurContext) {
Douglas Gregor43d88632009-11-04 22:49:18 +000030 if (T.isNull())
31 return 0;
John McCall31f17ec2010-04-27 00:57:59 +000032
33 const Type *Ty = T->getCanonicalTypeInternal().getTypePtr();
Douglas Gregord9ea1802011-02-19 19:24:40 +000034 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))
John McCall31f17ec2010-04-27 00:57:59 +000048 return cast<InjectedClassNameType>(Ty)->getDecl();
49 else
50 return 0;
Douglas Gregor43d88632009-11-04 22:49:18 +000051}
52
Douglas Gregor2dd078a2009-09-02 22:59:36 +000053/// \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///
Mike Stump1eb44332009-09-09 15:08:12 +000057/// \returns the declaration context represented by the type T,
Douglas Gregor2dd078a2009-09-02 22:59:36 +000058/// or NULL if the declaration context cannot be computed (e.g., because it is
59/// dependent and not the current instantiation).
60DeclContext *Sema::computeDeclContext(QualType T) {
Douglas Gregord9ea1802011-02-19 19:24:40 +000061 if (!T->isDependentType())
62 if (const TagType *Tag = T->getAs<TagType>())
63 return Tag->getDecl();
Mike Stump1eb44332009-09-09 15:08:12 +000064
Douglas Gregord9ea1802011-02-19 19:24:40 +000065 return ::getCurrentInstantiationOf(T, CurContext);
Douglas Gregor2dd078a2009-09-02 22:59:36 +000066}
67
Douglas Gregore4e5b052009-03-19 00:18:19 +000068/// \brief Compute the DeclContext that is associated with the given
69/// scope specifier.
Douglas Gregorf59a56e2009-07-21 23:53:31 +000070///
71/// \param SS the C++ scope specifier as it appears in the source
72///
73/// \param EnteringContext when true, we will be entering the context of
74/// this scope specifier, so we can retrieve the declaration context of a
75/// class template or class template partial specialization even if it is
76/// not the current instantiation.
77///
78/// \returns the declaration context represented by the scope specifier @p SS,
79/// or NULL if the declaration context cannot be computed (e.g., because it is
80/// dependent and not the current instantiation).
81DeclContext *Sema::computeDeclContext(const CXXScopeSpec &SS,
82 bool EnteringContext) {
Douglas Gregore4e5b052009-03-19 00:18:19 +000083 if (!SS.isSet() || SS.isInvalid())
Douglas Gregorca5e77f2009-03-18 00:36:05 +000084 return 0;
Douglas Gregorca5e77f2009-03-18 00:36:05 +000085
Mike Stump1eb44332009-09-09 15:08:12 +000086 NestedNameSpecifier *NNS
Douglas Gregor35073692009-03-26 23:56:24 +000087 = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
Douglas Gregor42af25f2009-05-11 19:58:34 +000088 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;
Mike Stump1eb44332009-09-09 15:08:12 +000093
Douglas Gregorf59a56e2009-07-21 23:53:31 +000094 if (EnteringContext) {
John McCall3cb0ebd2010-03-10 03:28:59 +000095 const Type *NNSType = NNS->getAsType();
96 if (!NNSType) {
Richard Smith3e4c6c42011-05-05 21:57:07 +000097 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>()) {
Douglas Gregor495c35d2009-08-25 22:51:20 +0000104 // 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.
Mike Stump1eb44332009-09-09 15:08:12 +0000107 if (ClassTemplateDecl *ClassTemplate
Douglas Gregorf59a56e2009-07-21 23:53:31 +0000108 = dyn_cast_or_null<ClassTemplateDecl>(
109 SpecType->getTemplateName().getAsTemplateDecl())) {
Douglas Gregorb88e8882009-07-30 17:40:51 +0000110 QualType ContextType
111 = Context.getCanonicalType(QualType(SpecType, 0));
112
Douglas Gregorf59a56e2009-07-21 23:53:31 +0000113 // 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.
John McCall3cb0ebd2010-03-10 03:28:59 +0000116 QualType Injected
Douglas Gregor24bae922010-07-08 18:37:38 +0000117 = ClassTemplate->getInjectedClassNameSpecialization();
Douglas Gregorb88e8882009-07-30 17:40:51 +0000118 if (Context.hasSameType(Injected, ContextType))
Douglas Gregorf59a56e2009-07-21 23:53:31 +0000119 return ClassTemplate->getTemplatedDecl();
Mike Stump1eb44332009-09-09 15:08:12 +0000120
Douglas Gregorb88e8882009-07-30 17:40:51 +0000121 // 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;
Douglas Gregorf59a56e2009-07-21 23:53:31 +0000128 }
John McCall3cb0ebd2010-03-10 03:28:59 +0000129 } else if (const RecordType *RecordT = NNSType->getAs<RecordType>()) {
Douglas Gregor495c35d2009-08-25 22:51:20 +0000130 // The nested name specifier refers to a member of a class template.
131 return RecordT->getDecl();
Douglas Gregorf59a56e2009-07-21 23:53:31 +0000132 }
133 }
Mike Stump1eb44332009-09-09 15:08:12 +0000134
Douglas Gregorf59a56e2009-07-21 23:53:31 +0000135 return 0;
Douglas Gregor42af25f2009-05-11 19:58:34 +0000136 }
Douglas Gregorab452ba2009-03-26 23:50:42 +0000137
138 switch (NNS->getKind()) {
139 case NestedNameSpecifier::Identifier:
David Blaikieb219cfc2011-09-23 05:06:16 +0000140 llvm_unreachable("Dependent nested-name-specifier has no DeclContext");
Douglas Gregorab452ba2009-03-26 23:50:42 +0000141
142 case NestedNameSpecifier::Namespace:
143 return NNS->getAsNamespace();
144
Douglas Gregor14aba762011-02-24 02:36:08 +0000145 case NestedNameSpecifier::NamespaceAlias:
146 return NNS->getAsNamespaceAlias()->getNamespace();
147
Douglas Gregorab452ba2009-03-26 23:50:42 +0000148 case NestedNameSpecifier::TypeSpec:
149 case NestedNameSpecifier::TypeSpecWithTemplate: {
Douglas Gregoredc90502010-02-25 04:46:04 +0000150 const TagType *Tag = NNS->getAsType()->getAs<TagType>();
151 assert(Tag && "Non-tag type in nested-name-specifier");
152 return Tag->getDecl();
David Blaikie7530c032012-01-17 06:56:22 +0000153 }
Douglas Gregorab452ba2009-03-26 23:50:42 +0000154
155 case NestedNameSpecifier::Global:
156 return Context.getTranslationUnitDecl();
157 }
158
David Blaikie7530c032012-01-17 06:56:22 +0000159 llvm_unreachable("Invalid NestedNameSpecifier::Kind!");
Douglas Gregorca5e77f2009-03-18 00:36:05 +0000160}
161
Douglas Gregor5953d8b2009-03-19 17:26:29 +0000162bool Sema::isDependentScopeSpecifier(const CXXScopeSpec &SS) {
163 if (!SS.isSet() || SS.isInvalid())
164 return false;
165
Mike Stump1eb44332009-09-09 15:08:12 +0000166 NestedNameSpecifier *NNS
Douglas Gregor35073692009-03-26 23:56:24 +0000167 = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
Douglas Gregorab452ba2009-03-26 23:50:42 +0000168 return NNS->isDependent();
Douglas Gregor5953d8b2009-03-19 17:26:29 +0000169}
170
Douglas Gregor42af25f2009-05-11 19:58:34 +0000171// \brief Determine whether this C++ scope specifier refers to an
172// unknown specialization, i.e., a dependent type that is not the
173// current instantiation.
174bool Sema::isUnknownSpecialization(const CXXScopeSpec &SS) {
175 if (!isDependentScopeSpecifier(SS))
176 return false;
177
Mike Stump1eb44332009-09-09 15:08:12 +0000178 NestedNameSpecifier *NNS
Douglas Gregor42af25f2009-05-11 19:58:34 +0000179 = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
180 return getCurrentInstantiationOf(NNS) == 0;
181}
182
183/// \brief If the given nested name specifier refers to the current
184/// instantiation, return the declaration that corresponds to that
185/// current instantiation (C++0x [temp.dep.type]p1).
186///
187/// \param NNS a dependent nested name specifier.
188CXXRecordDecl *Sema::getCurrentInstantiationOf(NestedNameSpecifier *NNS) {
189 assert(getLangOptions().CPlusPlus && "Only callable in C++");
190 assert(NNS->isDependent() && "Only dependent nested-name-specifier allowed");
191
Douglas Gregorf59a56e2009-07-21 23:53:31 +0000192 if (!NNS->getAsType())
193 return 0;
Mike Stump1eb44332009-09-09 15:08:12 +0000194
Douglas Gregor1560def2009-07-31 18:32:42 +0000195 QualType T = QualType(NNS->getAsType(), 0);
Douglas Gregord9ea1802011-02-19 19:24:40 +0000196 return ::getCurrentInstantiationOf(T, CurContext);
Douglas Gregor42af25f2009-05-11 19:58:34 +0000197}
198
Douglas Gregor4fdf1fa2009-03-11 16:48:53 +0000199/// \brief Require that the context specified by SS be complete.
200///
201/// If SS refers to a type, this routine checks whether the type is
202/// complete enough (or can be made complete enough) for name lookup
203/// into the DeclContext. A type that is not yet completed can be
204/// considered "complete enough" if it is a class/struct/union/enum
205/// that is currently being defined. Or, if we have a type that names
206/// a class template specialization that is not a complete type, we
207/// will attempt to instantiate that class template.
John McCall77bb1aa2010-05-01 00:40:08 +0000208bool Sema::RequireCompleteDeclContext(CXXScopeSpec &SS,
209 DeclContext *DC) {
210 assert(DC != 0 && "given null context");
Mike Stump1eb44332009-09-09 15:08:12 +0000211
John McCall9dc71d22011-07-06 06:57:57 +0000212 if (TagDecl *tag = dyn_cast<TagDecl>(DC)) {
Douglas Gregora4e8c2a2010-02-05 04:39:02 +0000213 // If this is a dependent type, then we consider it complete.
John McCall9dc71d22011-07-06 06:57:57 +0000214 if (tag->isDependentContext())
Douglas Gregora4e8c2a2010-02-05 04:39:02 +0000215 return false;
216
Douglas Gregor4fdf1fa2009-03-11 16:48:53 +0000217 // If we're currently defining this type, then lookup into the
218 // type is okay: don't complain that it isn't complete yet.
John McCall9dc71d22011-07-06 06:57:57 +0000219 QualType type = Context.getTypeDeclType(tag);
220 const TagType *tagType = type->getAs<TagType>();
221 if (tagType && tagType->isBeingDefined())
Douglas Gregor4fdf1fa2009-03-11 16:48:53 +0000222 return false;
223
John McCall9dc71d22011-07-06 06:57:57 +0000224 SourceLocation loc = SS.getLastQualifierNameLoc();
225 if (loc.isInvalid()) loc = SS.getRange().getBegin();
226
Douglas Gregor4fdf1fa2009-03-11 16:48:53 +0000227 // The type must be complete.
John McCall9dc71d22011-07-06 06:57:57 +0000228 if (RequireCompleteType(loc, type,
Jeffrey Yasskin9ab14542010-04-08 16:38:48 +0000229 PDiag(diag::err_incomplete_nested_name_spec)
John McCall77bb1aa2010-05-01 00:40:08 +0000230 << SS.getRange())) {
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000231 SS.SetInvalid(SS.getRange());
Jeffrey Yasskin9ab14542010-04-08 16:38:48 +0000232 return true;
233 }
John McCall9dc71d22011-07-06 06:57:57 +0000234
235 // Fixed enum types are complete, but they aren't valid as scopes
236 // until we see a definition, so awkwardly pull out this special
237 // case.
238 if (const EnumType *enumType = dyn_cast_or_null<EnumType>(tagType)) {
John McCall5e1cdac2011-10-07 06:10:15 +0000239 if (!enumType->getDecl()->isCompleteDefinition()) {
John McCall9dc71d22011-07-06 06:57:57 +0000240 Diag(loc, diag::err_incomplete_nested_name_spec)
241 << type << SS.getRange();
242 SS.SetInvalid(SS.getRange());
243 return true;
244 }
245 }
Douglas Gregor4fdf1fa2009-03-11 16:48:53 +0000246 }
247
248 return false;
249}
Cedric Venet3d658642009-02-14 20:20:19 +0000250
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000251bool Sema::ActOnCXXGlobalScopeSpecifier(Scope *S, SourceLocation CCLoc,
252 CXXScopeSpec &SS) {
253 SS.MakeGlobal(Context, CCLoc);
254 return false;
Cedric Venet3d658642009-02-14 20:20:19 +0000255}
256
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000257/// \brief Determines whether the given declaration is an valid acceptable
258/// result for name lookup of a nested-name-specifier.
Douglas Gregoredc90502010-02-25 04:46:04 +0000259bool Sema::isAcceptableNestedNameSpecifier(NamedDecl *SD) {
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000260 if (!SD)
261 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000262
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000263 // Namespace and namespace aliases are fine.
264 if (isa<NamespaceDecl>(SD) || isa<NamespaceAliasDecl>(SD))
265 return true;
Mike Stump1eb44332009-09-09 15:08:12 +0000266
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000267 if (!isa<TypeDecl>(SD))
268 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000269
Richard Smith6b130222011-10-18 21:39:00 +0000270 // Determine whether we have a class (or, in C++11, an enum) or
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000271 // a typedef thereof. If so, build the nested-name-specifier.
272 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD));
273 if (T->isDependentType())
274 return true;
Richard Smith162e1c12011-04-15 14:24:37 +0000275 else if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(SD)) {
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000276 if (TD->getUnderlyingType()->isRecordType() ||
Mike Stump1eb44332009-09-09 15:08:12 +0000277 (Context.getLangOptions().CPlusPlus0x &&
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000278 TD->getUnderlyingType()->isEnumeralType()))
279 return true;
Mike Stump1eb44332009-09-09 15:08:12 +0000280 } else if (isa<RecordDecl>(SD) ||
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000281 (Context.getLangOptions().CPlusPlus0x && isa<EnumDecl>(SD)))
282 return true;
283
284 return false;
285}
286
Douglas Gregorc68afe22009-09-03 21:38:09 +0000287/// \brief If the given nested-name-specifier begins with a bare identifier
Mike Stump1eb44332009-09-09 15:08:12 +0000288/// (e.g., Base::), perform name lookup for that identifier as a
Douglas Gregorc68afe22009-09-03 21:38:09 +0000289/// nested-name-specifier within the given scope, and return the result of that
290/// name lookup.
291NamedDecl *Sema::FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS) {
292 if (!S || !NNS)
293 return 0;
Mike Stump1eb44332009-09-09 15:08:12 +0000294
Douglas Gregorc68afe22009-09-03 21:38:09 +0000295 while (NNS->getPrefix())
296 NNS = NNS->getPrefix();
Mike Stump1eb44332009-09-09 15:08:12 +0000297
Douglas Gregorc68afe22009-09-03 21:38:09 +0000298 if (NNS->getKind() != NestedNameSpecifier::Identifier)
299 return 0;
Mike Stump1eb44332009-09-09 15:08:12 +0000300
John McCalla24dc2e2009-11-17 02:14:36 +0000301 LookupResult Found(*this, NNS->getAsIdentifier(), SourceLocation(),
302 LookupNestedNameSpecifierName);
303 LookupName(Found, S);
Douglas Gregorc68afe22009-09-03 21:38:09 +0000304 assert(!Found.isAmbiguous() && "Cannot handle ambiguities here yet");
305
John McCall1bcee0a2009-12-02 08:25:40 +0000306 if (!Found.isSingleResult())
307 return 0;
308
309 NamedDecl *Result = Found.getFoundDecl();
Douglas Gregoredc90502010-02-25 04:46:04 +0000310 if (isAcceptableNestedNameSpecifier(Result))
Douglas Gregorc68afe22009-09-03 21:38:09 +0000311 return Result;
Mike Stump1eb44332009-09-09 15:08:12 +0000312
Douglas Gregorc68afe22009-09-03 21:38:09 +0000313 return 0;
314}
315
Jeffrey Yasskin9ab14542010-04-08 16:38:48 +0000316bool Sema::isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS,
Douglas Gregor77549082010-02-24 21:29:12 +0000317 SourceLocation IdLoc,
318 IdentifierInfo &II,
John McCallb3d87482010-08-24 05:47:05 +0000319 ParsedType ObjectTypePtr) {
Douglas Gregor77549082010-02-24 21:29:12 +0000320 QualType ObjectType = GetTypeFromParser(ObjectTypePtr);
321 LookupResult Found(*this, &II, IdLoc, LookupNestedNameSpecifierName);
322
323 // Determine where to perform name lookup
324 DeclContext *LookupCtx = 0;
325 bool isDependent = false;
326 if (!ObjectType.isNull()) {
327 // This nested-name-specifier occurs in a member access expression, e.g.,
328 // x->B::f, and we are looking into the type of the object.
329 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist");
330 LookupCtx = computeDeclContext(ObjectType);
331 isDependent = ObjectType->isDependentType();
332 } else if (SS.isSet()) {
333 // This nested-name-specifier occurs after another nested-name-specifier,
334 // so long into the context associated with the prior nested-name-specifier.
335 LookupCtx = computeDeclContext(SS, false);
336 isDependent = isDependentScopeSpecifier(SS);
337 Found.setContextRange(SS.getRange());
338 }
339
340 if (LookupCtx) {
341 // Perform "qualified" name lookup into the declaration context we
342 // computed, which is either the type of the base of a member access
343 // expression or the declaration context associated with a prior
344 // nested-name-specifier.
345
346 // The declaration context must be complete.
John McCall77bb1aa2010-05-01 00:40:08 +0000347 if (!LookupCtx->isDependentContext() &&
348 RequireCompleteDeclContext(SS, LookupCtx))
Douglas Gregor77549082010-02-24 21:29:12 +0000349 return false;
350
351 LookupQualifiedName(Found, LookupCtx);
352 } else if (isDependent) {
353 return false;
354 } else {
355 LookupName(Found, S);
356 }
357 Found.suppressDiagnostics();
358
359 if (NamedDecl *ND = Found.getAsSingle<NamedDecl>())
360 return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND);
361
362 return false;
363}
364
Kaelyn Uhrain3b4b0472012-01-12 22:32:39 +0000365namespace {
366
367// Callback to only accept typo corrections that can be a valid C++ member
368// intializer: either a non-static field member or a base class.
369class NestedNameSpecifierValidatorCCC : public CorrectionCandidateCallback {
370 public:
371 explicit NestedNameSpecifierValidatorCCC(Sema &SRef)
372 : SRef(SRef) {}
373
374 virtual bool ValidateCandidate(const TypoCorrection &candidate) {
375 return SRef.isAcceptableNestedNameSpecifier(candidate.getCorrectionDecl());
376 }
377
378 private:
379 Sema &SRef;
380};
381
382}
383
Douglas Gregorc68afe22009-09-03 21:38:09 +0000384/// \brief Build a new nested-name-specifier for "identifier::", as described
385/// by ActOnCXXNestedNameSpecifier.
386///
387/// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in
388/// that it contains an extra parameter \p ScopeLookupResult, which provides
389/// the result of name lookup within the scope of the nested-name-specifier
Douglas Gregora6e51992009-12-30 16:01:52 +0000390/// that was computed at template definition time.
Chris Lattner46646492009-12-07 01:36:53 +0000391///
392/// If ErrorRecoveryLookup is true, then this call is used to improve error
393/// recovery. This means that it should not emit diagnostics, it should
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000394/// just return true on failure. It also means it should only return a valid
Chris Lattner46646492009-12-07 01:36:53 +0000395/// scope if it *knows* that the result is correct. It should not return in a
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000396/// dependent context, for example. Nor will it extend \p SS with the scope
397/// specifier.
398bool Sema::BuildCXXNestedNameSpecifier(Scope *S,
399 IdentifierInfo &Identifier,
400 SourceLocation IdentifierLoc,
401 SourceLocation CCLoc,
402 QualType ObjectType,
403 bool EnteringContext,
404 CXXScopeSpec &SS,
405 NamedDecl *ScopeLookupResult,
406 bool ErrorRecoveryLookup) {
407 LookupResult Found(*this, &Identifier, IdentifierLoc,
408 LookupNestedNameSpecifierName);
John McCalla24dc2e2009-11-17 02:14:36 +0000409
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000410 // Determine where to perform name lookup
411 DeclContext *LookupCtx = 0;
412 bool isDependent = false;
Douglas Gregorc68afe22009-09-03 21:38:09 +0000413 if (!ObjectType.isNull()) {
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000414 // This nested-name-specifier occurs in a member access expression, e.g.,
415 // x->B::f, and we are looking into the type of the object.
416 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist");
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000417 LookupCtx = computeDeclContext(ObjectType);
418 isDependent = ObjectType->isDependentType();
419 } else if (SS.isSet()) {
420 // This nested-name-specifier occurs after another nested-name-specifier,
Richard Smith3e4c6c42011-05-05 21:57:07 +0000421 // so look into the context associated with the prior nested-name-specifier.
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000422 LookupCtx = computeDeclContext(SS, EnteringContext);
423 isDependent = isDependentScopeSpecifier(SS);
John McCalla24dc2e2009-11-17 02:14:36 +0000424 Found.setContextRange(SS.getRange());
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000425 }
Mike Stump1eb44332009-09-09 15:08:12 +0000426
John McCalla24dc2e2009-11-17 02:14:36 +0000427
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000428 bool ObjectTypeSearchedInScope = false;
429 if (LookupCtx) {
Mike Stump1eb44332009-09-09 15:08:12 +0000430 // Perform "qualified" name lookup into the declaration context we
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000431 // computed, which is either the type of the base of a member access
Mike Stump1eb44332009-09-09 15:08:12 +0000432 // expression or the declaration context associated with a prior
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000433 // nested-name-specifier.
Mike Stump1eb44332009-09-09 15:08:12 +0000434
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000435 // The declaration context must be complete.
John McCall77bb1aa2010-05-01 00:40:08 +0000436 if (!LookupCtx->isDependentContext() &&
437 RequireCompleteDeclContext(SS, LookupCtx))
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000438 return true;
Mike Stump1eb44332009-09-09 15:08:12 +0000439
John McCalla24dc2e2009-11-17 02:14:36 +0000440 LookupQualifiedName(Found, LookupCtx);
Mike Stump1eb44332009-09-09 15:08:12 +0000441
John McCalla24dc2e2009-11-17 02:14:36 +0000442 if (!ObjectType.isNull() && Found.empty()) {
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000443 // C++ [basic.lookup.classref]p4:
444 // If the id-expression in a class member access is a qualified-id of
Mike Stump1eb44332009-09-09 15:08:12 +0000445 // the form
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000446 //
447 // class-name-or-namespace-name::...
448 //
Mike Stump1eb44332009-09-09 15:08:12 +0000449 // the class-name-or-namespace-name following the . or -> operator is
450 // looked up both in the context of the entire postfix-expression and in
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000451 // the scope of the class of the object expression. If the name is found
Mike Stump1eb44332009-09-09 15:08:12 +0000452 // only in the scope of the class of the object expression, the name
453 // shall refer to a class-name. If the name is found only in the
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000454 // context of the entire postfix-expression, the name shall refer to a
455 // class-name or namespace-name. [...]
456 //
457 // Qualified name lookup into a class will not find a namespace-name,
Douglas Gregor714c9922011-05-15 17:27:27 +0000458 // so we do not need to diagnose that case specifically. However,
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000459 // this qualified name lookup may find nothing. In that case, perform
Mike Stump1eb44332009-09-09 15:08:12 +0000460 // unqualified name lookup in the given scope (if available) or
Douglas Gregorc68afe22009-09-03 21:38:09 +0000461 // reconstruct the result from when name lookup was performed at template
462 // definition time.
463 if (S)
John McCalla24dc2e2009-11-17 02:14:36 +0000464 LookupName(Found, S);
John McCallf36e02d2009-10-09 21:13:30 +0000465 else if (ScopeLookupResult)
466 Found.addDecl(ScopeLookupResult);
Mike Stump1eb44332009-09-09 15:08:12 +0000467
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000468 ObjectTypeSearchedInScope = true;
469 }
Douglas Gregorac7cbd82010-07-28 14:49:07 +0000470 } else if (!isDependent) {
471 // Perform unqualified name lookup in the current scope.
472 LookupName(Found, S);
473 }
474
475 // If we performed lookup into a dependent context and did not find anything,
476 // that's fine: just build a dependent nested-name-specifier.
477 if (Found.empty() && isDependent &&
478 !(LookupCtx && LookupCtx->isRecord() &&
479 (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() ||
480 !cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases()))) {
Chris Lattner46646492009-12-07 01:36:53 +0000481 // Don't speculate if we're just trying to improve error recovery.
482 if (ErrorRecoveryLookup)
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000483 return true;
Chris Lattner46646492009-12-07 01:36:53 +0000484
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000485 // We were not able to compute the declaration context for a dependent
Mike Stump1eb44332009-09-09 15:08:12 +0000486 // base object type or prior nested-name-specifier, so this
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000487 // nested-name-specifier refers to an unknown specialization. Just build
488 // a dependent nested-name-specifier.
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000489 SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc);
490 return false;
Douglas Gregorac7cbd82010-07-28 14:49:07 +0000491 }
492
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000493 // FIXME: Deal with ambiguities cleanly.
Douglas Gregor175a6562009-12-31 08:26:35 +0000494
495 if (Found.empty() && !ErrorRecoveryLookup) {
496 // We haven't found anything, and we're not recovering from a
497 // different kind of error, so look for typos.
498 DeclarationName Name = Found.getLookupName();
Kaelyn Uhrain3b4b0472012-01-12 22:32:39 +0000499 NestedNameSpecifierValidatorCCC Validator(*this);
Douglas Gregord8bba9c2011-06-28 16:20:02 +0000500 TypoCorrection Corrected;
501 Found.clear();
502 if ((Corrected = CorrectTypo(Found.getLookupNameInfo(),
Kaelyn Uhrain3b4b0472012-01-12 22:32:39 +0000503 Found.getLookupKind(), S, &SS, &Validator,
504 LookupCtx, EnteringContext))) {
Douglas Gregord8bba9c2011-06-28 16:20:02 +0000505 std::string CorrectedStr(Corrected.getAsString(getLangOptions()));
506 std::string CorrectedQuotedStr(Corrected.getQuoted(getLangOptions()));
Douglas Gregor175a6562009-12-31 08:26:35 +0000507 if (LookupCtx)
508 Diag(Found.getNameLoc(), diag::err_no_member_suggest)
Douglas Gregord8bba9c2011-06-28 16:20:02 +0000509 << Name << LookupCtx << CorrectedQuotedStr << SS.getRange()
510 << FixItHint::CreateReplacement(Found.getNameLoc(), CorrectedStr);
Douglas Gregor175a6562009-12-31 08:26:35 +0000511 else
512 Diag(Found.getNameLoc(), diag::err_undeclared_var_use_suggest)
Douglas Gregord8bba9c2011-06-28 16:20:02 +0000513 << Name << CorrectedQuotedStr
514 << FixItHint::CreateReplacement(Found.getNameLoc(), CorrectedStr);
Douglas Gregor67dd1d42010-01-07 00:17:44 +0000515
Douglas Gregord8bba9c2011-06-28 16:20:02 +0000516 if (NamedDecl *ND = Corrected.getCorrectionDecl()) {
517 Diag(ND->getLocation(), diag::note_previous_decl) << CorrectedQuotedStr;
518 Found.addDecl(ND);
519 }
520 Found.setLookupName(Corrected.getCorrection());
Douglas Gregor12eb5d62010-06-29 19:27:42 +0000521 } else {
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000522 Found.setLookupName(&Identifier);
Douglas Gregor12eb5d62010-06-29 19:27:42 +0000523 }
Douglas Gregor175a6562009-12-31 08:26:35 +0000524 }
525
John McCall1bcee0a2009-12-02 08:25:40 +0000526 NamedDecl *SD = Found.getAsSingle<NamedDecl>();
Douglas Gregoredc90502010-02-25 04:46:04 +0000527 if (isAcceptableNestedNameSpecifier(SD)) {
Douglas Gregorc68afe22009-09-03 21:38:09 +0000528 if (!ObjectType.isNull() && !ObjectTypeSearchedInScope) {
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000529 // C++ [basic.lookup.classref]p4:
Mike Stump1eb44332009-09-09 15:08:12 +0000530 // [...] If the name is found in both contexts, the
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000531 // class-name-or-namespace-name shall refer to the same entity.
532 //
533 // We already found the name in the scope of the object. Now, look
534 // into the current scope (the scope of the postfix-expression) to
Douglas Gregorc68afe22009-09-03 21:38:09 +0000535 // see if we can find the same name there. As above, if there is no
536 // scope, reconstruct the result from the template instantiation itself.
John McCallf36e02d2009-10-09 21:13:30 +0000537 NamedDecl *OuterDecl;
538 if (S) {
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000539 LookupResult FoundOuter(*this, &Identifier, IdentifierLoc,
540 LookupNestedNameSpecifierName);
John McCalla24dc2e2009-11-17 02:14:36 +0000541 LookupName(FoundOuter, S);
John McCall1bcee0a2009-12-02 08:25:40 +0000542 OuterDecl = FoundOuter.getAsSingle<NamedDecl>();
John McCallf36e02d2009-10-09 21:13:30 +0000543 } else
544 OuterDecl = ScopeLookupResult;
Mike Stump1eb44332009-09-09 15:08:12 +0000545
Douglas Gregoredc90502010-02-25 04:46:04 +0000546 if (isAcceptableNestedNameSpecifier(OuterDecl) &&
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000547 OuterDecl->getCanonicalDecl() != SD->getCanonicalDecl() &&
548 (!isa<TypeDecl>(OuterDecl) || !isa<TypeDecl>(SD) ||
549 !Context.hasSameType(
Douglas Gregorc68afe22009-09-03 21:38:09 +0000550 Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)),
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000551 Context.getTypeDeclType(cast<TypeDecl>(SD))))) {
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000552 if (ErrorRecoveryLookup)
553 return true;
Mike Stump1eb44332009-09-09 15:08:12 +0000554
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000555 Diag(IdentifierLoc,
556 diag::err_nested_name_member_ref_lookup_ambiguous)
557 << &Identifier;
558 Diag(SD->getLocation(), diag::note_ambig_member_ref_object_type)
559 << ObjectType;
560 Diag(OuterDecl->getLocation(), diag::note_ambig_member_ref_scope);
561
562 // Fall through so that we'll pick the name we found in the object
563 // type, since that's probably what the user wanted anyway.
564 }
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000565 }
Mike Stump1eb44332009-09-09 15:08:12 +0000566
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000567 // If we're just performing this lookup for error-recovery purposes,
568 // don't extend the nested-name-specifier. Just return now.
569 if (ErrorRecoveryLookup)
570 return false;
571
572 if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD)) {
573 SS.Extend(Context, Namespace, IdentifierLoc, CCLoc);
574 return false;
575 }
Mike Stump1eb44332009-09-09 15:08:12 +0000576
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000577 if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD)) {
Douglas Gregor14aba762011-02-24 02:36:08 +0000578 SS.Extend(Context, Alias, IdentifierLoc, CCLoc);
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000579 return false;
580 }
Mike Stump1eb44332009-09-09 15:08:12 +0000581
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000582 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD));
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000583 TypeLocBuilder TLB;
584 if (isa<InjectedClassNameType>(T)) {
585 InjectedClassNameTypeLoc InjectedTL
586 = TLB.push<InjectedClassNameTypeLoc>(T);
587 InjectedTL.setNameLoc(IdentifierLoc);
Douglas Gregorbd61e342011-05-04 23:05:40 +0000588 } else if (isa<RecordType>(T)) {
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000589 RecordTypeLoc RecordTL = TLB.push<RecordTypeLoc>(T);
590 RecordTL.setNameLoc(IdentifierLoc);
Douglas Gregorbd61e342011-05-04 23:05:40 +0000591 } else if (isa<TypedefType>(T)) {
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000592 TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(T);
593 TypedefTL.setNameLoc(IdentifierLoc);
Douglas Gregorbd61e342011-05-04 23:05:40 +0000594 } else if (isa<EnumType>(T)) {
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000595 EnumTypeLoc EnumTL = TLB.push<EnumTypeLoc>(T);
596 EnumTL.setNameLoc(IdentifierLoc);
Douglas Gregorbd61e342011-05-04 23:05:40 +0000597 } else if (isa<TemplateTypeParmType>(T)) {
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000598 TemplateTypeParmTypeLoc TemplateTypeTL
599 = TLB.push<TemplateTypeParmTypeLoc>(T);
600 TemplateTypeTL.setNameLoc(IdentifierLoc);
Douglas Gregorbd61e342011-05-04 23:05:40 +0000601 } else if (isa<UnresolvedUsingType>(T)) {
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000602 UnresolvedUsingTypeLoc UnresolvedTL
603 = TLB.push<UnresolvedUsingTypeLoc>(T);
604 UnresolvedTL.setNameLoc(IdentifierLoc);
Douglas Gregorbd61e342011-05-04 23:05:40 +0000605 } else if (isa<SubstTemplateTypeParmType>(T)) {
606 SubstTemplateTypeParmTypeLoc TL
607 = TLB.push<SubstTemplateTypeParmTypeLoc>(T);
608 TL.setNameLoc(IdentifierLoc);
609 } else if (isa<SubstTemplateTypeParmPackType>(T)) {
610 SubstTemplateTypeParmPackTypeLoc TL
611 = TLB.push<SubstTemplateTypeParmPackTypeLoc>(T);
612 TL.setNameLoc(IdentifierLoc);
613 } else {
614 llvm_unreachable("Unhandled TypeDecl node in nested-name-specifier");
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000615 }
616
Richard Smith95aafb22011-10-20 03:28:47 +0000617 if (T->isEnumeralType())
618 Diag(IdentifierLoc, diag::warn_cxx98_compat_enum_nested_name_spec);
619
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000620 SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T),
621 CCLoc);
622 return false;
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000623 }
Mike Stump1eb44332009-09-09 15:08:12 +0000624
Chris Lattner46646492009-12-07 01:36:53 +0000625 // Otherwise, we have an error case. If we don't want diagnostics, just
626 // return an error now.
627 if (ErrorRecoveryLookup)
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000628 return true;
Chris Lattner46646492009-12-07 01:36:53 +0000629
Cedric Venet3d658642009-02-14 20:20:19 +0000630 // If we didn't find anything during our lookup, try again with
631 // ordinary name lookup, which can help us produce better error
632 // messages.
John McCall1bcee0a2009-12-02 08:25:40 +0000633 if (Found.empty()) {
John McCalla24dc2e2009-11-17 02:14:36 +0000634 Found.clear(LookupOrdinaryName);
635 LookupName(Found, S);
John McCallf36e02d2009-10-09 21:13:30 +0000636 }
Mike Stump1eb44332009-09-09 15:08:12 +0000637
Francois Pichetdfb6ae12011-07-27 01:05:24 +0000638 // In Microsoft mode, if we are within a templated function and we can't
639 // resolve Identifier, then extend the SS with Identifier. This will have
640 // the effect of resolving Identifier during template instantiation.
641 // The goal is to be able to resolve a function call whose
642 // nested-name-specifier is located inside a dependent base class.
643 // Example:
644 //
645 // class C {
646 // public:
647 // static void foo2() { }
648 // };
649 // template <class T> class A { public: typedef C D; };
650 //
651 // template <class T> class B : public A<T> {
652 // public:
653 // void foo() { D::foo2(); }
654 // };
Francois Pichet62ec1f22011-09-17 17:15:52 +0000655 if (getLangOptions().MicrosoftExt) {
Francois Pichetdfb6ae12011-07-27 01:05:24 +0000656 DeclContext *DC = LookupCtx ? LookupCtx : CurContext;
657 if (DC->isDependentContext() && DC->isFunctionOrMethod()) {
658 SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc);
659 return false;
660 }
661 }
662
Cedric Venet3d658642009-02-14 20:20:19 +0000663 unsigned DiagID;
John McCall1bcee0a2009-12-02 08:25:40 +0000664 if (!Found.empty())
Cedric Venet3d658642009-02-14 20:20:19 +0000665 DiagID = diag::err_expected_class_or_namespace;
Anders Carlssona31d5f72009-08-30 07:09:50 +0000666 else if (SS.isSet()) {
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000667 Diag(IdentifierLoc, diag::err_no_member)
668 << &Identifier << LookupCtx << SS.getRange();
669 return true;
Anders Carlssona31d5f72009-08-30 07:09:50 +0000670 } else
Cedric Venet3d658642009-02-14 20:20:19 +0000671 DiagID = diag::err_undeclared_var_use;
Mike Stump1eb44332009-09-09 15:08:12 +0000672
Cedric Venet3d658642009-02-14 20:20:19 +0000673 if (SS.isSet())
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000674 Diag(IdentifierLoc, DiagID) << &Identifier << SS.getRange();
Cedric Venet3d658642009-02-14 20:20:19 +0000675 else
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000676 Diag(IdentifierLoc, DiagID) << &Identifier;
Mike Stump1eb44332009-09-09 15:08:12 +0000677
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000678 return true;
Cedric Venet3d658642009-02-14 20:20:19 +0000679}
680
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000681bool Sema::ActOnCXXNestedNameSpecifier(Scope *S,
682 IdentifierInfo &Identifier,
683 SourceLocation IdentifierLoc,
684 SourceLocation CCLoc,
685 ParsedType ObjectType,
686 bool EnteringContext,
687 CXXScopeSpec &SS) {
688 if (SS.isInvalid())
689 return true;
690
691 return BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, CCLoc,
692 GetTypeFromParser(ObjectType),
693 EnteringContext, SS,
694 /*ScopeLookupResult=*/0, false);
Chris Lattner46646492009-12-07 01:36:53 +0000695}
696
David Blaikie42d6d0c2011-12-04 05:04:18 +0000697bool Sema::ActOnCXXNestedNameSpecifierDecltype(CXXScopeSpec &SS,
698 const DeclSpec &DS,
699 SourceLocation ColonColonLoc) {
700 if (SS.isInvalid() || DS.getTypeSpecType() == DeclSpec::TST_error)
701 return true;
702
703 assert(DS.getTypeSpecType() == DeclSpec::TST_decltype);
704
705 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
706 if (!T->isDependentType() && !T->getAs<TagType>()) {
707 Diag(DS.getTypeSpecTypeLoc(), diag::err_expected_class)
708 << T << getLangOptions().CPlusPlus;
709 return true;
710 }
711
712 TypeLocBuilder TLB;
713 DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T);
714 DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc());
715 SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T),
716 ColonColonLoc);
717 return false;
718}
719
Chris Lattner46646492009-12-07 01:36:53 +0000720/// IsInvalidUnlessNestedName - This method is used for error recovery
721/// purposes to determine whether the specified identifier is only valid as
722/// a nested name specifier, for example a namespace name. It is
723/// conservatively correct to always return false from this method.
724///
725/// The arguments are the same as those passed to ActOnCXXNestedNameSpecifier.
Jeffrey Yasskin9ab14542010-04-08 16:38:48 +0000726bool Sema::IsInvalidUnlessNestedName(Scope *S, CXXScopeSpec &SS,
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000727 IdentifierInfo &Identifier,
728 SourceLocation IdentifierLoc,
729 SourceLocation ColonLoc,
730 ParsedType ObjectType,
Chris Lattner46646492009-12-07 01:36:53 +0000731 bool EnteringContext) {
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000732 if (SS.isInvalid())
733 return false;
734
735 return !BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, ColonLoc,
736 GetTypeFromParser(ObjectType),
737 EnteringContext, SS,
738 /*ScopeLookupResult=*/0, true);
Douglas Gregorc68afe22009-09-03 21:38:09 +0000739}
740
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000741bool Sema::ActOnCXXNestedNameSpecifier(Scope *S,
Douglas Gregoraa2187d2011-02-28 00:04:36 +0000742 SourceLocation TemplateLoc,
743 CXXScopeSpec &SS,
744 TemplateTy Template,
745 SourceLocation TemplateNameLoc,
746 SourceLocation LAngleLoc,
747 ASTTemplateArgsPtr TemplateArgsIn,
748 SourceLocation RAngleLoc,
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000749 SourceLocation CCLoc,
Douglas Gregoraa2187d2011-02-28 00:04:36 +0000750 bool EnteringContext) {
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000751 if (SS.isInvalid())
752 return true;
753
Douglas Gregoraa2187d2011-02-28 00:04:36 +0000754 // Translate the parser's template argument list in our AST format.
755 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
756 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
757
758 if (DependentTemplateName *DTN = Template.get().getAsDependentTemplateName()){
759 // Handle a dependent template specialization for which we cannot resolve
760 // the template name.
761 assert(DTN->getQualifier()
762 == static_cast<NestedNameSpecifier*>(SS.getScopeRep()));
763 QualType T = Context.getDependentTemplateSpecializationType(ETK_None,
Douglas Gregor94fdffa2011-03-01 20:11:18 +0000764 DTN->getQualifier(),
765 DTN->getIdentifier(),
Douglas Gregoraa2187d2011-02-28 00:04:36 +0000766 TemplateArgs);
767
768 // Create source-location information for this type.
769 TypeLocBuilder Builder;
770 DependentTemplateSpecializationTypeLoc SpecTL
771 = Builder.push<DependentTemplateSpecializationTypeLoc>(T);
772 SpecTL.setLAngleLoc(LAngleLoc);
773 SpecTL.setRAngleLoc(RAngleLoc);
774 SpecTL.setKeywordLoc(SourceLocation());
775 SpecTL.setNameLoc(TemplateNameLoc);
Douglas Gregor94fdffa2011-03-01 20:11:18 +0000776 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
Douglas Gregoraa2187d2011-02-28 00:04:36 +0000777 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
778 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
779
780 SS.Extend(Context, TemplateLoc, Builder.getTypeLocInContext(Context, T),
781 CCLoc);
782 return false;
783 }
784
Douglas Gregor6cd9d4a2011-03-04 21:37:14 +0000785
786 if (Template.get().getAsOverloadedTemplate() ||
787 isa<FunctionTemplateDecl>(Template.get().getAsTemplateDecl())) {
788 SourceRange R(TemplateNameLoc, RAngleLoc);
789 if (SS.getRange().isValid())
790 R.setBegin(SS.getRange().getBegin());
791
792 Diag(CCLoc, diag::err_non_type_template_in_nested_name_specifier)
793 << Template.get() << R;
794 NoteAllFoundTemplates(Template.get());
795 return true;
796 }
797
Douglas Gregoraa2187d2011-02-28 00:04:36 +0000798 // We were able to resolve the template name to an actual template.
799 // Build an appropriate nested-name-specifier.
800 QualType T = CheckTemplateIdType(Template.get(), TemplateNameLoc,
801 TemplateArgs);
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000802 if (T.isNull())
803 return true;
804
Richard Smith3e4c6c42011-05-05 21:57:07 +0000805 // Alias template specializations can produce types which are not valid
806 // nested name specifiers.
807 if (!T->isDependentType() && !T->getAs<TagType>()) {
808 Diag(TemplateNameLoc, diag::err_nested_name_spec_non_tag) << T;
809 NoteAllFoundTemplates(Template.get());
810 return true;
811 }
Douglas Gregoraa2187d2011-02-28 00:04:36 +0000812
813 // Provide source-location information for the template specialization
814 // type.
815 TypeLocBuilder Builder;
816 TemplateSpecializationTypeLoc SpecTL
817 = Builder.push<TemplateSpecializationTypeLoc>(T);
818
819 SpecTL.setLAngleLoc(LAngleLoc);
820 SpecTL.setRAngleLoc(RAngleLoc);
821 SpecTL.setTemplateNameLoc(TemplateNameLoc);
822 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
823 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
824
825
826 SS.Extend(Context, TemplateLoc, Builder.getTypeLocInContext(Context, T),
827 CCLoc);
Douglas Gregor2e4c34a2011-02-24 00:17:56 +0000828 return false;
Douglas Gregor39a8de12009-02-25 19:37:18 +0000829}
830
Douglas Gregorc34348a2011-02-24 17:54:50 +0000831namespace {
832 /// \brief A structure that stores a nested-name-specifier annotation,
833 /// including both the nested-name-specifier
834 struct NestedNameSpecifierAnnotation {
835 NestedNameSpecifier *NNS;
836 };
837}
838
839void *Sema::SaveNestedNameSpecifierAnnotation(CXXScopeSpec &SS) {
840 if (SS.isEmpty() || SS.isInvalid())
841 return 0;
842
843 void *Mem = Context.Allocate((sizeof(NestedNameSpecifierAnnotation) +
844 SS.location_size()),
845 llvm::alignOf<NestedNameSpecifierAnnotation>());
846 NestedNameSpecifierAnnotation *Annotation
847 = new (Mem) NestedNameSpecifierAnnotation;
848 Annotation->NNS = SS.getScopeRep();
849 memcpy(Annotation + 1, SS.location_data(), SS.location_size());
850 return Annotation;
851}
852
853void Sema::RestoreNestedNameSpecifierAnnotation(void *AnnotationPtr,
854 SourceRange AnnotationRange,
855 CXXScopeSpec &SS) {
856 if (!AnnotationPtr) {
857 SS.SetInvalid(AnnotationRange);
858 return;
859 }
860
861 NestedNameSpecifierAnnotation *Annotation
862 = static_cast<NestedNameSpecifierAnnotation *>(AnnotationPtr);
863 SS.Adopt(NestedNameSpecifierLoc(Annotation->NNS, Annotation + 1));
864}
865
John McCalle7e278b2009-12-11 20:04:54 +0000866bool Sema::ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS) {
867 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec.");
868
869 NestedNameSpecifier *Qualifier =
870 static_cast<NestedNameSpecifier*>(SS.getScopeRep());
871
872 // There are only two places a well-formed program may qualify a
873 // declarator: first, when defining a namespace or class member
874 // out-of-line, and second, when naming an explicitly-qualified
875 // friend function. The latter case is governed by
876 // C++03 [basic.lookup.unqual]p10:
877 // In a friend declaration naming a member function, a name used
878 // in the function declarator and not part of a template-argument
879 // in a template-id is first looked up in the scope of the member
880 // function's class. If it is not found, or if the name is part of
881 // a template-argument in a template-id, the look up is as
882 // described for unqualified names in the definition of the class
883 // granting friendship.
884 // i.e. we don't push a scope unless it's a class member.
885
886 switch (Qualifier->getKind()) {
887 case NestedNameSpecifier::Global:
888 case NestedNameSpecifier::Namespace:
Douglas Gregor14aba762011-02-24 02:36:08 +0000889 case NestedNameSpecifier::NamespaceAlias:
John McCalle7e278b2009-12-11 20:04:54 +0000890 // These are always namespace scopes. We never want to enter a
891 // namespace scope from anything but a file context.
Sebastian Redl7a126a42010-08-31 00:36:30 +0000892 return CurContext->getRedeclContext()->isFileContext();
John McCalle7e278b2009-12-11 20:04:54 +0000893
894 case NestedNameSpecifier::Identifier:
895 case NestedNameSpecifier::TypeSpec:
896 case NestedNameSpecifier::TypeSpecWithTemplate:
897 // These are never namespace scopes.
898 return true;
899 }
900
David Blaikie7530c032012-01-17 06:56:22 +0000901 llvm_unreachable("Invalid NestedNameSpecifier::Kind!");
John McCalle7e278b2009-12-11 20:04:54 +0000902}
903
Cedric Venet3d658642009-02-14 20:20:19 +0000904/// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global
905/// scope or nested-name-specifier) is parsed, part of a declarator-id.
906/// After this method is called, according to [C++ 3.4.3p3], names should be
907/// looked up in the declarator-id's scope, until the declarator is parsed and
908/// ActOnCXXExitDeclaratorScope is called.
909/// The 'SS' should be a non-empty valid CXXScopeSpec.
Jeffrey Yasskin9ab14542010-04-08 16:38:48 +0000910bool Sema::ActOnCXXEnterDeclaratorScope(Scope *S, CXXScopeSpec &SS) {
Cedric Venet3d658642009-02-14 20:20:19 +0000911 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec.");
John McCall7a1dc562009-12-19 10:49:29 +0000912
913 if (SS.isInvalid()) return true;
914
915 DeclContext *DC = computeDeclContext(SS, true);
916 if (!DC) return true;
917
918 // Before we enter a declarator's context, we need to make sure that
919 // it is a complete declaration context.
John McCall77bb1aa2010-05-01 00:40:08 +0000920 if (!DC->isDependentContext() && RequireCompleteDeclContext(SS, DC))
John McCall7a1dc562009-12-19 10:49:29 +0000921 return true;
922
923 EnterDeclaratorContext(S, DC);
John McCall31f17ec2010-04-27 00:57:59 +0000924
925 // Rebuild the nested name specifier for the new scope.
926 if (DC->isDependentContext())
927 RebuildNestedNameSpecifierInCurrentInstantiation(SS);
928
Douglas Gregor7dfd0fb2009-09-24 23:39:01 +0000929 return false;
Cedric Venet3d658642009-02-14 20:20:19 +0000930}
931
932/// ActOnCXXExitDeclaratorScope - Called when a declarator that previously
933/// invoked ActOnCXXEnterDeclaratorScope(), is finished. 'SS' is the same
934/// CXXScopeSpec that was passed to ActOnCXXEnterDeclaratorScope as well.
935/// Used to indicate that names should revert to being looked up in the
936/// defining scope.
937void Sema::ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS) {
938 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec.");
Douglas Gregordacd4342009-08-26 00:04:55 +0000939 if (SS.isInvalid())
940 return;
John McCall7a1dc562009-12-19 10:49:29 +0000941 assert(!SS.isInvalid() && computeDeclContext(SS, true) &&
942 "exiting declarator scope we never really entered");
943 ExitDeclaratorContext(S);
Cedric Venet3d658642009-02-14 20:20:19 +0000944}