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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
14#include "Sema.h"
John McCall7d384dd2009-11-18 07:57:50 +000015#include "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"
Cedric Venet3d658642009-02-14 20:20:19 +000021#include "clang/Parse/DeclSpec.h"
22#include "llvm/ADT/STLExtras.h"
Douglas Gregor7551c182009-07-22 00:28:09 +000023#include "llvm/Support/raw_ostream.h"
Cedric Venet3d658642009-02-14 20:20:19 +000024using namespace clang;
25
Douglas Gregor43d88632009-11-04 22:49:18 +000026/// \brief Find the current instantiation that associated with the given type.
John McCall31f17ec2010-04-27 00:57:59 +000027static CXXRecordDecl *getCurrentInstantiationOf(QualType T) {
Douglas Gregor43d88632009-11-04 22:49:18 +000028 if (T.isNull())
29 return 0;
John McCall31f17ec2010-04-27 00:57:59 +000030
31 const Type *Ty = T->getCanonicalTypeInternal().getTypePtr();
32 if (isa<RecordType>(Ty))
33 return cast<CXXRecordDecl>(cast<RecordType>(Ty)->getDecl());
34 else if (isa<InjectedClassNameType>(Ty))
35 return cast<InjectedClassNameType>(Ty)->getDecl();
36 else
37 return 0;
Douglas Gregor43d88632009-11-04 22:49:18 +000038}
39
Douglas Gregor2dd078a2009-09-02 22:59:36 +000040/// \brief Compute the DeclContext that is associated with the given type.
41///
42/// \param T the type for which we are attempting to find a DeclContext.
43///
Mike Stump1eb44332009-09-09 15:08:12 +000044/// \returns the declaration context represented by the type T,
Douglas Gregor2dd078a2009-09-02 22:59:36 +000045/// or NULL if the declaration context cannot be computed (e.g., because it is
46/// dependent and not the current instantiation).
47DeclContext *Sema::computeDeclContext(QualType T) {
48 if (const TagType *Tag = T->getAs<TagType>())
49 return Tag->getDecl();
Mike Stump1eb44332009-09-09 15:08:12 +000050
John McCall31f17ec2010-04-27 00:57:59 +000051 return ::getCurrentInstantiationOf(T);
Douglas Gregor2dd078a2009-09-02 22:59:36 +000052}
53
Douglas Gregore4e5b052009-03-19 00:18:19 +000054/// \brief Compute the DeclContext that is associated with the given
55/// scope specifier.
Douglas Gregorf59a56e2009-07-21 23:53:31 +000056///
57/// \param SS the C++ scope specifier as it appears in the source
58///
59/// \param EnteringContext when true, we will be entering the context of
60/// this scope specifier, so we can retrieve the declaration context of a
61/// class template or class template partial specialization even if it is
62/// not the current instantiation.
63///
64/// \returns the declaration context represented by the scope specifier @p SS,
65/// or NULL if the declaration context cannot be computed (e.g., because it is
66/// dependent and not the current instantiation).
67DeclContext *Sema::computeDeclContext(const CXXScopeSpec &SS,
68 bool EnteringContext) {
Douglas Gregore4e5b052009-03-19 00:18:19 +000069 if (!SS.isSet() || SS.isInvalid())
Douglas Gregorca5e77f2009-03-18 00:36:05 +000070 return 0;
Douglas Gregorca5e77f2009-03-18 00:36:05 +000071
Mike Stump1eb44332009-09-09 15:08:12 +000072 NestedNameSpecifier *NNS
Douglas Gregor35073692009-03-26 23:56:24 +000073 = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
Douglas Gregor42af25f2009-05-11 19:58:34 +000074 if (NNS->isDependent()) {
75 // If this nested-name-specifier refers to the current
76 // instantiation, return its DeclContext.
77 if (CXXRecordDecl *Record = getCurrentInstantiationOf(NNS))
78 return Record;
Mike Stump1eb44332009-09-09 15:08:12 +000079
Douglas Gregorf59a56e2009-07-21 23:53:31 +000080 if (EnteringContext) {
John McCall3cb0ebd2010-03-10 03:28:59 +000081 const Type *NNSType = NNS->getAsType();
82 if (!NNSType) {
83 // do nothing, fall out
84 } else if (const TemplateSpecializationType *SpecType
85 = NNSType->getAs<TemplateSpecializationType>()) {
Douglas Gregor495c35d2009-08-25 22:51:20 +000086 // We are entering the context of the nested name specifier, so try to
87 // match the nested name specifier to either a primary class template
88 // or a class template partial specialization.
Mike Stump1eb44332009-09-09 15:08:12 +000089 if (ClassTemplateDecl *ClassTemplate
Douglas Gregorf59a56e2009-07-21 23:53:31 +000090 = dyn_cast_or_null<ClassTemplateDecl>(
91 SpecType->getTemplateName().getAsTemplateDecl())) {
Douglas Gregorb88e8882009-07-30 17:40:51 +000092 QualType ContextType
93 = Context.getCanonicalType(QualType(SpecType, 0));
94
Douglas Gregorf59a56e2009-07-21 23:53:31 +000095 // If the type of the nested name specifier is the same as the
96 // injected class name of the named class template, we're entering
97 // into that class template definition.
John McCall3cb0ebd2010-03-10 03:28:59 +000098 QualType Injected
99 = ClassTemplate->getInjectedClassNameSpecialization(Context);
Douglas Gregorb88e8882009-07-30 17:40:51 +0000100 if (Context.hasSameType(Injected, ContextType))
Douglas Gregorf59a56e2009-07-21 23:53:31 +0000101 return ClassTemplate->getTemplatedDecl();
Mike Stump1eb44332009-09-09 15:08:12 +0000102
Douglas Gregorb88e8882009-07-30 17:40:51 +0000103 // If the type of the nested name specifier is the same as the
104 // type of one of the class template's class template partial
105 // specializations, we're entering into the definition of that
106 // class template partial specialization.
107 if (ClassTemplatePartialSpecializationDecl *PartialSpec
108 = ClassTemplate->findPartialSpecialization(ContextType))
109 return PartialSpec;
Douglas Gregorf59a56e2009-07-21 23:53:31 +0000110 }
John McCall3cb0ebd2010-03-10 03:28:59 +0000111 } else if (const RecordType *RecordT = NNSType->getAs<RecordType>()) {
Douglas Gregor495c35d2009-08-25 22:51:20 +0000112 // The nested name specifier refers to a member of a class template.
113 return RecordT->getDecl();
Douglas Gregorf59a56e2009-07-21 23:53:31 +0000114 }
115 }
Mike Stump1eb44332009-09-09 15:08:12 +0000116
Douglas Gregorf59a56e2009-07-21 23:53:31 +0000117 return 0;
Douglas Gregor42af25f2009-05-11 19:58:34 +0000118 }
Douglas Gregorab452ba2009-03-26 23:50:42 +0000119
120 switch (NNS->getKind()) {
121 case NestedNameSpecifier::Identifier:
122 assert(false && "Dependent nested-name-specifier has no DeclContext");
123 break;
124
125 case NestedNameSpecifier::Namespace:
126 return NNS->getAsNamespace();
127
128 case NestedNameSpecifier::TypeSpec:
129 case NestedNameSpecifier::TypeSpecWithTemplate: {
Douglas Gregoredc90502010-02-25 04:46:04 +0000130 const TagType *Tag = NNS->getAsType()->getAs<TagType>();
131 assert(Tag && "Non-tag type in nested-name-specifier");
132 return Tag->getDecl();
133 } break;
Douglas Gregorab452ba2009-03-26 23:50:42 +0000134
135 case NestedNameSpecifier::Global:
136 return Context.getTranslationUnitDecl();
137 }
138
Douglas Gregoredc90502010-02-25 04:46:04 +0000139 // Required to silence a GCC warning.
Douglas Gregorab452ba2009-03-26 23:50:42 +0000140 return 0;
Douglas Gregorca5e77f2009-03-18 00:36:05 +0000141}
142
Douglas Gregor5953d8b2009-03-19 17:26:29 +0000143bool Sema::isDependentScopeSpecifier(const CXXScopeSpec &SS) {
144 if (!SS.isSet() || SS.isInvalid())
145 return false;
146
Mike Stump1eb44332009-09-09 15:08:12 +0000147 NestedNameSpecifier *NNS
Douglas Gregor35073692009-03-26 23:56:24 +0000148 = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
Douglas Gregorab452ba2009-03-26 23:50:42 +0000149 return NNS->isDependent();
Douglas Gregor5953d8b2009-03-19 17:26:29 +0000150}
151
Douglas Gregor42af25f2009-05-11 19:58:34 +0000152// \brief Determine whether this C++ scope specifier refers to an
153// unknown specialization, i.e., a dependent type that is not the
154// current instantiation.
155bool Sema::isUnknownSpecialization(const CXXScopeSpec &SS) {
156 if (!isDependentScopeSpecifier(SS))
157 return false;
158
Mike Stump1eb44332009-09-09 15:08:12 +0000159 NestedNameSpecifier *NNS
Douglas Gregor42af25f2009-05-11 19:58:34 +0000160 = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
161 return getCurrentInstantiationOf(NNS) == 0;
162}
163
164/// \brief If the given nested name specifier refers to the current
165/// instantiation, return the declaration that corresponds to that
166/// current instantiation (C++0x [temp.dep.type]p1).
167///
168/// \param NNS a dependent nested name specifier.
169CXXRecordDecl *Sema::getCurrentInstantiationOf(NestedNameSpecifier *NNS) {
170 assert(getLangOptions().CPlusPlus && "Only callable in C++");
171 assert(NNS->isDependent() && "Only dependent nested-name-specifier allowed");
172
Douglas Gregorf59a56e2009-07-21 23:53:31 +0000173 if (!NNS->getAsType())
174 return 0;
Mike Stump1eb44332009-09-09 15:08:12 +0000175
Douglas Gregor1560def2009-07-31 18:32:42 +0000176 QualType T = QualType(NNS->getAsType(), 0);
John McCall31f17ec2010-04-27 00:57:59 +0000177 return ::getCurrentInstantiationOf(T);
Douglas Gregor42af25f2009-05-11 19:58:34 +0000178}
179
Douglas Gregor4fdf1fa2009-03-11 16:48:53 +0000180/// \brief Require that the context specified by SS be complete.
181///
182/// If SS refers to a type, this routine checks whether the type is
183/// complete enough (or can be made complete enough) for name lookup
184/// into the DeclContext. A type that is not yet completed can be
185/// considered "complete enough" if it is a class/struct/union/enum
186/// that is currently being defined. Or, if we have a type that names
187/// a class template specialization that is not a complete type, we
188/// will attempt to instantiate that class template.
John McCall77bb1aa2010-05-01 00:40:08 +0000189bool Sema::RequireCompleteDeclContext(CXXScopeSpec &SS,
190 DeclContext *DC) {
191 assert(DC != 0 && "given null context");
Mike Stump1eb44332009-09-09 15:08:12 +0000192
Douglas Gregor4fdf1fa2009-03-11 16:48:53 +0000193 if (TagDecl *Tag = dyn_cast<TagDecl>(DC)) {
Douglas Gregora4e8c2a2010-02-05 04:39:02 +0000194 // If this is a dependent type, then we consider it complete.
195 if (Tag->isDependentContext())
196 return false;
197
Douglas Gregor4fdf1fa2009-03-11 16:48:53 +0000198 // If we're currently defining this type, then lookup into the
199 // type is okay: don't complain that it isn't complete yet.
Ted Kremenek6217b802009-07-29 21:53:49 +0000200 const TagType *TagT = Context.getTypeDeclType(Tag)->getAs<TagType>();
John McCall3cb0ebd2010-03-10 03:28:59 +0000201 if (TagT && TagT->isBeingDefined())
Douglas Gregor4fdf1fa2009-03-11 16:48:53 +0000202 return false;
203
204 // The type must be complete.
Jeffrey Yasskin9ab14542010-04-08 16:38:48 +0000205 if (RequireCompleteType(SS.getRange().getBegin(),
206 Context.getTypeDeclType(Tag),
207 PDiag(diag::err_incomplete_nested_name_spec)
John McCall77bb1aa2010-05-01 00:40:08 +0000208 << SS.getRange())) {
Jeffrey Yasskin9ab14542010-04-08 16:38:48 +0000209 SS.setScopeRep(0); // Mark the ScopeSpec invalid.
210 return true;
211 }
Douglas Gregor4fdf1fa2009-03-11 16:48:53 +0000212 }
213
214 return false;
215}
Cedric Venet3d658642009-02-14 20:20:19 +0000216
217/// ActOnCXXGlobalScopeSpecifier - Return the object that represents the
218/// global scope ('::').
219Sema::CXXScopeTy *Sema::ActOnCXXGlobalScopeSpecifier(Scope *S,
220 SourceLocation CCLoc) {
Douglas Gregorab452ba2009-03-26 23:50:42 +0000221 return NestedNameSpecifier::GlobalSpecifier(Context);
Cedric Venet3d658642009-02-14 20:20:19 +0000222}
223
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000224/// \brief Determines whether the given declaration is an valid acceptable
225/// result for name lookup of a nested-name-specifier.
Douglas Gregoredc90502010-02-25 04:46:04 +0000226bool Sema::isAcceptableNestedNameSpecifier(NamedDecl *SD) {
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000227 if (!SD)
228 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000229
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000230 // Namespace and namespace aliases are fine.
231 if (isa<NamespaceDecl>(SD) || isa<NamespaceAliasDecl>(SD))
232 return true;
Mike Stump1eb44332009-09-09 15:08:12 +0000233
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000234 if (!isa<TypeDecl>(SD))
235 return false;
Mike Stump1eb44332009-09-09 15:08:12 +0000236
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000237 // Determine whether we have a class (or, in C++0x, an enum) or
238 // a typedef thereof. If so, build the nested-name-specifier.
239 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD));
240 if (T->isDependentType())
241 return true;
242 else if (TypedefDecl *TD = dyn_cast<TypedefDecl>(SD)) {
243 if (TD->getUnderlyingType()->isRecordType() ||
Mike Stump1eb44332009-09-09 15:08:12 +0000244 (Context.getLangOptions().CPlusPlus0x &&
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000245 TD->getUnderlyingType()->isEnumeralType()))
246 return true;
Mike Stump1eb44332009-09-09 15:08:12 +0000247 } else if (isa<RecordDecl>(SD) ||
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000248 (Context.getLangOptions().CPlusPlus0x && isa<EnumDecl>(SD)))
249 return true;
250
251 return false;
252}
253
Douglas Gregorc68afe22009-09-03 21:38:09 +0000254/// \brief If the given nested-name-specifier begins with a bare identifier
Mike Stump1eb44332009-09-09 15:08:12 +0000255/// (e.g., Base::), perform name lookup for that identifier as a
Douglas Gregorc68afe22009-09-03 21:38:09 +0000256/// nested-name-specifier within the given scope, and return the result of that
257/// name lookup.
258NamedDecl *Sema::FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS) {
259 if (!S || !NNS)
260 return 0;
Mike Stump1eb44332009-09-09 15:08:12 +0000261
Douglas Gregorc68afe22009-09-03 21:38:09 +0000262 while (NNS->getPrefix())
263 NNS = NNS->getPrefix();
Mike Stump1eb44332009-09-09 15:08:12 +0000264
Douglas Gregorc68afe22009-09-03 21:38:09 +0000265 if (NNS->getKind() != NestedNameSpecifier::Identifier)
266 return 0;
Mike Stump1eb44332009-09-09 15:08:12 +0000267
John McCalla24dc2e2009-11-17 02:14:36 +0000268 LookupResult Found(*this, NNS->getAsIdentifier(), SourceLocation(),
269 LookupNestedNameSpecifierName);
270 LookupName(Found, S);
Douglas Gregorc68afe22009-09-03 21:38:09 +0000271 assert(!Found.isAmbiguous() && "Cannot handle ambiguities here yet");
272
John McCall1bcee0a2009-12-02 08:25:40 +0000273 if (!Found.isSingleResult())
274 return 0;
275
276 NamedDecl *Result = Found.getFoundDecl();
Douglas Gregoredc90502010-02-25 04:46:04 +0000277 if (isAcceptableNestedNameSpecifier(Result))
Douglas Gregorc68afe22009-09-03 21:38:09 +0000278 return Result;
Mike Stump1eb44332009-09-09 15:08:12 +0000279
Douglas Gregorc68afe22009-09-03 21:38:09 +0000280 return 0;
281}
282
Jeffrey Yasskin9ab14542010-04-08 16:38:48 +0000283bool Sema::isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS,
Douglas Gregor77549082010-02-24 21:29:12 +0000284 SourceLocation IdLoc,
285 IdentifierInfo &II,
286 TypeTy *ObjectTypePtr) {
287 QualType ObjectType = GetTypeFromParser(ObjectTypePtr);
288 LookupResult Found(*this, &II, IdLoc, LookupNestedNameSpecifierName);
289
290 // Determine where to perform name lookup
291 DeclContext *LookupCtx = 0;
292 bool isDependent = false;
293 if (!ObjectType.isNull()) {
294 // This nested-name-specifier occurs in a member access expression, e.g.,
295 // x->B::f, and we are looking into the type of the object.
296 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist");
297 LookupCtx = computeDeclContext(ObjectType);
298 isDependent = ObjectType->isDependentType();
299 } else if (SS.isSet()) {
300 // This nested-name-specifier occurs after another nested-name-specifier,
301 // so long into the context associated with the prior nested-name-specifier.
302 LookupCtx = computeDeclContext(SS, false);
303 isDependent = isDependentScopeSpecifier(SS);
304 Found.setContextRange(SS.getRange());
305 }
306
307 if (LookupCtx) {
308 // Perform "qualified" name lookup into the declaration context we
309 // computed, which is either the type of the base of a member access
310 // expression or the declaration context associated with a prior
311 // nested-name-specifier.
312
313 // The declaration context must be complete.
John McCall77bb1aa2010-05-01 00:40:08 +0000314 if (!LookupCtx->isDependentContext() &&
315 RequireCompleteDeclContext(SS, LookupCtx))
Douglas Gregor77549082010-02-24 21:29:12 +0000316 return false;
317
318 LookupQualifiedName(Found, LookupCtx);
319 } else if (isDependent) {
320 return false;
321 } else {
322 LookupName(Found, S);
323 }
324 Found.suppressDiagnostics();
325
326 if (NamedDecl *ND = Found.getAsSingle<NamedDecl>())
327 return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND);
328
329 return false;
330}
331
Douglas Gregorc68afe22009-09-03 21:38:09 +0000332/// \brief Build a new nested-name-specifier for "identifier::", as described
333/// by ActOnCXXNestedNameSpecifier.
334///
335/// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in
336/// that it contains an extra parameter \p ScopeLookupResult, which provides
337/// the result of name lookup within the scope of the nested-name-specifier
Douglas Gregora6e51992009-12-30 16:01:52 +0000338/// that was computed at template definition time.
Chris Lattner46646492009-12-07 01:36:53 +0000339///
340/// If ErrorRecoveryLookup is true, then this call is used to improve error
341/// recovery. This means that it should not emit diagnostics, it should
342/// just return null on failure. It also means it should only return a valid
343/// scope if it *knows* that the result is correct. It should not return in a
344/// dependent context, for example.
Douglas Gregorc68afe22009-09-03 21:38:09 +0000345Sema::CXXScopeTy *Sema::BuildCXXNestedNameSpecifier(Scope *S,
Jeffrey Yasskin9ab14542010-04-08 16:38:48 +0000346 CXXScopeSpec &SS,
Cedric Venet3d658642009-02-14 20:20:19 +0000347 SourceLocation IdLoc,
348 SourceLocation CCLoc,
Douglas Gregor495c35d2009-08-25 22:51:20 +0000349 IdentifierInfo &II,
Douglas Gregorc68afe22009-09-03 21:38:09 +0000350 QualType ObjectType,
351 NamedDecl *ScopeLookupResult,
Chris Lattner46646492009-12-07 01:36:53 +0000352 bool EnteringContext,
353 bool ErrorRecoveryLookup) {
Mike Stump1eb44332009-09-09 15:08:12 +0000354 NestedNameSpecifier *Prefix
Douglas Gregor35073692009-03-26 23:56:24 +0000355 = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
Mike Stump1eb44332009-09-09 15:08:12 +0000356
John McCalla24dc2e2009-11-17 02:14:36 +0000357 LookupResult Found(*this, &II, IdLoc, LookupNestedNameSpecifierName);
358
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000359 // Determine where to perform name lookup
360 DeclContext *LookupCtx = 0;
361 bool isDependent = false;
Douglas Gregorc68afe22009-09-03 21:38:09 +0000362 if (!ObjectType.isNull()) {
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000363 // This nested-name-specifier occurs in a member access expression, e.g.,
364 // x->B::f, and we are looking into the type of the object.
365 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist");
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000366 LookupCtx = computeDeclContext(ObjectType);
367 isDependent = ObjectType->isDependentType();
368 } else if (SS.isSet()) {
369 // This nested-name-specifier occurs after another nested-name-specifier,
370 // so long into the context associated with the prior nested-name-specifier.
371 LookupCtx = computeDeclContext(SS, EnteringContext);
372 isDependent = isDependentScopeSpecifier(SS);
John McCalla24dc2e2009-11-17 02:14:36 +0000373 Found.setContextRange(SS.getRange());
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000374 }
Mike Stump1eb44332009-09-09 15:08:12 +0000375
John McCalla24dc2e2009-11-17 02:14:36 +0000376
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000377 bool ObjectTypeSearchedInScope = false;
378 if (LookupCtx) {
Mike Stump1eb44332009-09-09 15:08:12 +0000379 // Perform "qualified" name lookup into the declaration context we
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000380 // computed, which is either the type of the base of a member access
Mike Stump1eb44332009-09-09 15:08:12 +0000381 // expression or the declaration context associated with a prior
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000382 // nested-name-specifier.
Mike Stump1eb44332009-09-09 15:08:12 +0000383
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000384 // The declaration context must be complete.
John McCall77bb1aa2010-05-01 00:40:08 +0000385 if (!LookupCtx->isDependentContext() &&
386 RequireCompleteDeclContext(SS, LookupCtx))
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000387 return 0;
Mike Stump1eb44332009-09-09 15:08:12 +0000388
John McCalla24dc2e2009-11-17 02:14:36 +0000389 LookupQualifiedName(Found, LookupCtx);
Mike Stump1eb44332009-09-09 15:08:12 +0000390
John McCalla24dc2e2009-11-17 02:14:36 +0000391 if (!ObjectType.isNull() && Found.empty()) {
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000392 // C++ [basic.lookup.classref]p4:
393 // If the id-expression in a class member access is a qualified-id of
Mike Stump1eb44332009-09-09 15:08:12 +0000394 // the form
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000395 //
396 // class-name-or-namespace-name::...
397 //
Mike Stump1eb44332009-09-09 15:08:12 +0000398 // the class-name-or-namespace-name following the . or -> operator is
399 // looked up both in the context of the entire postfix-expression and in
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000400 // the scope of the class of the object expression. If the name is found
Mike Stump1eb44332009-09-09 15:08:12 +0000401 // only in the scope of the class of the object expression, the name
402 // shall refer to a class-name. If the name is found only in the
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000403 // context of the entire postfix-expression, the name shall refer to a
404 // class-name or namespace-name. [...]
405 //
406 // Qualified name lookup into a class will not find a namespace-name,
Mike Stump1eb44332009-09-09 15:08:12 +0000407 // so we do not need to diagnoste that case specifically. However,
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000408 // this qualified name lookup may find nothing. In that case, perform
Mike Stump1eb44332009-09-09 15:08:12 +0000409 // unqualified name lookup in the given scope (if available) or
Douglas Gregorc68afe22009-09-03 21:38:09 +0000410 // reconstruct the result from when name lookup was performed at template
411 // definition time.
412 if (S)
John McCalla24dc2e2009-11-17 02:14:36 +0000413 LookupName(Found, S);
John McCallf36e02d2009-10-09 21:13:30 +0000414 else if (ScopeLookupResult)
415 Found.addDecl(ScopeLookupResult);
Mike Stump1eb44332009-09-09 15:08:12 +0000416
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000417 ObjectTypeSearchedInScope = true;
418 }
419 } else if (isDependent) {
Chris Lattner46646492009-12-07 01:36:53 +0000420 // Don't speculate if we're just trying to improve error recovery.
421 if (ErrorRecoveryLookup)
422 return 0;
423
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000424 // We were not able to compute the declaration context for a dependent
Mike Stump1eb44332009-09-09 15:08:12 +0000425 // base object type or prior nested-name-specifier, so this
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000426 // nested-name-specifier refers to an unknown specialization. Just build
427 // a dependent nested-name-specifier.
Douglas Gregor2700dcd2009-09-02 23:58:38 +0000428 if (!Prefix)
429 return NestedNameSpecifier::Create(Context, &II);
Mike Stump1eb44332009-09-09 15:08:12 +0000430
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000431 return NestedNameSpecifier::Create(Context, Prefix, &II);
432 } else {
433 // Perform unqualified name lookup in the current scope.
John McCalla24dc2e2009-11-17 02:14:36 +0000434 LookupName(Found, S);
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000435 }
Mike Stump1eb44332009-09-09 15:08:12 +0000436
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000437 // FIXME: Deal with ambiguities cleanly.
Douglas Gregor175a6562009-12-31 08:26:35 +0000438
439 if (Found.empty() && !ErrorRecoveryLookup) {
440 // We haven't found anything, and we're not recovering from a
441 // different kind of error, so look for typos.
442 DeclarationName Name = Found.getLookupName();
Douglas Gregoraaf87162010-04-14 20:04:41 +0000443 if (CorrectTypo(Found, S, &SS, LookupCtx, EnteringContext,
444 CTC_NoKeywords) &&
Douglas Gregor175a6562009-12-31 08:26:35 +0000445 Found.isSingleResult() &&
Douglas Gregoredc90502010-02-25 04:46:04 +0000446 isAcceptableNestedNameSpecifier(Found.getAsSingle<NamedDecl>())) {
Douglas Gregor175a6562009-12-31 08:26:35 +0000447 if (LookupCtx)
448 Diag(Found.getNameLoc(), diag::err_no_member_suggest)
449 << Name << LookupCtx << Found.getLookupName() << SS.getRange()
Douglas Gregor849b2432010-03-31 17:46:05 +0000450 << FixItHint::CreateReplacement(Found.getNameLoc(),
451 Found.getLookupName().getAsString());
Douglas Gregor175a6562009-12-31 08:26:35 +0000452 else
453 Diag(Found.getNameLoc(), diag::err_undeclared_var_use_suggest)
454 << Name << Found.getLookupName()
Douglas Gregor849b2432010-03-31 17:46:05 +0000455 << FixItHint::CreateReplacement(Found.getNameLoc(),
456 Found.getLookupName().getAsString());
Douglas Gregor67dd1d42010-01-07 00:17:44 +0000457
458 if (NamedDecl *ND = Found.getAsSingle<NamedDecl>())
459 Diag(ND->getLocation(), diag::note_previous_decl)
460 << ND->getDeclName();
Douglas Gregor175a6562009-12-31 08:26:35 +0000461 } else
462 Found.clear();
463 }
464
John McCall1bcee0a2009-12-02 08:25:40 +0000465 NamedDecl *SD = Found.getAsSingle<NamedDecl>();
Douglas Gregoredc90502010-02-25 04:46:04 +0000466 if (isAcceptableNestedNameSpecifier(SD)) {
Douglas Gregorc68afe22009-09-03 21:38:09 +0000467 if (!ObjectType.isNull() && !ObjectTypeSearchedInScope) {
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000468 // C++ [basic.lookup.classref]p4:
Mike Stump1eb44332009-09-09 15:08:12 +0000469 // [...] If the name is found in both contexts, the
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000470 // class-name-or-namespace-name shall refer to the same entity.
471 //
472 // We already found the name in the scope of the object. Now, look
473 // into the current scope (the scope of the postfix-expression) to
Douglas Gregorc68afe22009-09-03 21:38:09 +0000474 // see if we can find the same name there. As above, if there is no
475 // scope, reconstruct the result from the template instantiation itself.
John McCallf36e02d2009-10-09 21:13:30 +0000476 NamedDecl *OuterDecl;
477 if (S) {
Douglas Gregoredc90502010-02-25 04:46:04 +0000478 LookupResult FoundOuter(*this, &II, IdLoc, LookupNestedNameSpecifierName);
John McCalla24dc2e2009-11-17 02:14:36 +0000479 LookupName(FoundOuter, S);
John McCall1bcee0a2009-12-02 08:25:40 +0000480 OuterDecl = FoundOuter.getAsSingle<NamedDecl>();
John McCallf36e02d2009-10-09 21:13:30 +0000481 } else
482 OuterDecl = ScopeLookupResult;
Mike Stump1eb44332009-09-09 15:08:12 +0000483
Douglas Gregoredc90502010-02-25 04:46:04 +0000484 if (isAcceptableNestedNameSpecifier(OuterDecl) &&
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000485 OuterDecl->getCanonicalDecl() != SD->getCanonicalDecl() &&
486 (!isa<TypeDecl>(OuterDecl) || !isa<TypeDecl>(SD) ||
487 !Context.hasSameType(
Douglas Gregorc68afe22009-09-03 21:38:09 +0000488 Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)),
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000489 Context.getTypeDeclType(cast<TypeDecl>(SD))))) {
Chris Lattner46646492009-12-07 01:36:53 +0000490 if (ErrorRecoveryLookup)
491 return 0;
492
Douglas Gregorc68afe22009-09-03 21:38:09 +0000493 Diag(IdLoc, diag::err_nested_name_member_ref_lookup_ambiguous)
494 << &II;
495 Diag(SD->getLocation(), diag::note_ambig_member_ref_object_type)
496 << ObjectType;
497 Diag(OuterDecl->getLocation(), diag::note_ambig_member_ref_scope);
Mike Stump1eb44332009-09-09 15:08:12 +0000498
Chris Lattner46646492009-12-07 01:36:53 +0000499 // Fall through so that we'll pick the name we found in the object
500 // type, since that's probably what the user wanted anyway.
Douglas Gregorc68afe22009-09-03 21:38:09 +0000501 }
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000502 }
Mike Stump1eb44332009-09-09 15:08:12 +0000503
Douglas Gregorab452ba2009-03-26 23:50:42 +0000504 if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD))
505 return NestedNameSpecifier::Create(Context, Prefix, Namespace);
Mike Stump1eb44332009-09-09 15:08:12 +0000506
Douglas Gregordacd4342009-08-26 00:04:55 +0000507 // FIXME: It would be nice to maintain the namespace alias name, then
508 // see through that alias when resolving the nested-name-specifier down to
509 // a declaration context.
Anders Carlsson81c85c42009-03-28 23:53:49 +0000510 if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD))
511 return NestedNameSpecifier::Create(Context, Prefix,
Mike Stump1eb44332009-09-09 15:08:12 +0000512
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000513 Alias->getNamespace());
Mike Stump1eb44332009-09-09 15:08:12 +0000514
Douglas Gregor2dd078a2009-09-02 22:59:36 +0000515 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD));
516 return NestedNameSpecifier::Create(Context, Prefix, false,
517 T.getTypePtr());
518 }
Mike Stump1eb44332009-09-09 15:08:12 +0000519
Chris Lattner46646492009-12-07 01:36:53 +0000520 // Otherwise, we have an error case. If we don't want diagnostics, just
521 // return an error now.
522 if (ErrorRecoveryLookup)
523 return 0;
524
Cedric Venet3d658642009-02-14 20:20:19 +0000525 // If we didn't find anything during our lookup, try again with
526 // ordinary name lookup, which can help us produce better error
527 // messages.
John McCall1bcee0a2009-12-02 08:25:40 +0000528 if (Found.empty()) {
John McCalla24dc2e2009-11-17 02:14:36 +0000529 Found.clear(LookupOrdinaryName);
530 LookupName(Found, S);
John McCallf36e02d2009-10-09 21:13:30 +0000531 }
Mike Stump1eb44332009-09-09 15:08:12 +0000532
Cedric Venet3d658642009-02-14 20:20:19 +0000533 unsigned DiagID;
John McCall1bcee0a2009-12-02 08:25:40 +0000534 if (!Found.empty())
Cedric Venet3d658642009-02-14 20:20:19 +0000535 DiagID = diag::err_expected_class_or_namespace;
Anders Carlssona31d5f72009-08-30 07:09:50 +0000536 else if (SS.isSet()) {
Douglas Gregor3f093272009-10-13 21:16:44 +0000537 Diag(IdLoc, diag::err_no_member) << &II << LookupCtx << SS.getRange();
Anders Carlssona31d5f72009-08-30 07:09:50 +0000538 return 0;
539 } else
Cedric Venet3d658642009-02-14 20:20:19 +0000540 DiagID = diag::err_undeclared_var_use;
Mike Stump1eb44332009-09-09 15:08:12 +0000541
Cedric Venet3d658642009-02-14 20:20:19 +0000542 if (SS.isSet())
543 Diag(IdLoc, DiagID) << &II << SS.getRange();
544 else
545 Diag(IdLoc, DiagID) << &II;
Mike Stump1eb44332009-09-09 15:08:12 +0000546
Cedric Venet3d658642009-02-14 20:20:19 +0000547 return 0;
548}
549
Douglas Gregorc68afe22009-09-03 21:38:09 +0000550/// ActOnCXXNestedNameSpecifier - Called during parsing of a
551/// nested-name-specifier. e.g. for "foo::bar::" we parsed "foo::" and now
552/// we want to resolve "bar::". 'SS' is empty or the previously parsed
553/// nested-name part ("foo::"), 'IdLoc' is the source location of 'bar',
554/// 'CCLoc' is the location of '::' and 'II' is the identifier for 'bar'.
555/// Returns a CXXScopeTy* object representing the C++ scope.
556Sema::CXXScopeTy *Sema::ActOnCXXNestedNameSpecifier(Scope *S,
Jeffrey Yasskin9ab14542010-04-08 16:38:48 +0000557 CXXScopeSpec &SS,
Douglas Gregorc68afe22009-09-03 21:38:09 +0000558 SourceLocation IdLoc,
559 SourceLocation CCLoc,
560 IdentifierInfo &II,
561 TypeTy *ObjectTypePtr,
562 bool EnteringContext) {
Mike Stump1eb44332009-09-09 15:08:12 +0000563 return BuildCXXNestedNameSpecifier(S, SS, IdLoc, CCLoc, II,
Douglas Gregorc68afe22009-09-03 21:38:09 +0000564 QualType::getFromOpaquePtr(ObjectTypePtr),
Chris Lattner46646492009-12-07 01:36:53 +0000565 /*ScopeLookupResult=*/0, EnteringContext,
566 false);
567}
568
569/// IsInvalidUnlessNestedName - This method is used for error recovery
570/// purposes to determine whether the specified identifier is only valid as
571/// a nested name specifier, for example a namespace name. It is
572/// conservatively correct to always return false from this method.
573///
574/// The arguments are the same as those passed to ActOnCXXNestedNameSpecifier.
Jeffrey Yasskin9ab14542010-04-08 16:38:48 +0000575bool Sema::IsInvalidUnlessNestedName(Scope *S, CXXScopeSpec &SS,
Douglas Gregoredc90502010-02-25 04:46:04 +0000576 IdentifierInfo &II, TypeTy *ObjectType,
Chris Lattner46646492009-12-07 01:36:53 +0000577 bool EnteringContext) {
578 return BuildCXXNestedNameSpecifier(S, SS, SourceLocation(), SourceLocation(),
Douglas Gregoredc90502010-02-25 04:46:04 +0000579 II, QualType::getFromOpaquePtr(ObjectType),
Chris Lattner46646492009-12-07 01:36:53 +0000580 /*ScopeLookupResult=*/0, EnteringContext,
581 true);
Douglas Gregorc68afe22009-09-03 21:38:09 +0000582}
583
Douglas Gregor39a8de12009-02-25 19:37:18 +0000584Sema::CXXScopeTy *Sema::ActOnCXXNestedNameSpecifier(Scope *S,
585 const CXXScopeSpec &SS,
586 TypeTy *Ty,
587 SourceRange TypeRange,
Douglas Gregoredc90502010-02-25 04:46:04 +0000588 SourceLocation CCLoc) {
Mike Stump1eb44332009-09-09 15:08:12 +0000589 NestedNameSpecifier *Prefix
Douglas Gregor35073692009-03-26 23:56:24 +0000590 = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
Argyrios Kyrtzidise8661902009-08-19 01:28:28 +0000591 QualType T = GetTypeFromParser(Ty);
Douglas Gregorab452ba2009-03-26 23:50:42 +0000592 return NestedNameSpecifier::Create(Context, Prefix, /*FIXME:*/false,
Douglas Gregor3f5b61c2009-05-14 00:28:11 +0000593 T.getTypePtr());
Douglas Gregor39a8de12009-02-25 19:37:18 +0000594}
595
John McCalle7e278b2009-12-11 20:04:54 +0000596bool Sema::ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS) {
597 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec.");
598
599 NestedNameSpecifier *Qualifier =
600 static_cast<NestedNameSpecifier*>(SS.getScopeRep());
601
602 // There are only two places a well-formed program may qualify a
603 // declarator: first, when defining a namespace or class member
604 // out-of-line, and second, when naming an explicitly-qualified
605 // friend function. The latter case is governed by
606 // C++03 [basic.lookup.unqual]p10:
607 // In a friend declaration naming a member function, a name used
608 // in the function declarator and not part of a template-argument
609 // in a template-id is first looked up in the scope of the member
610 // function's class. If it is not found, or if the name is part of
611 // a template-argument in a template-id, the look up is as
612 // described for unqualified names in the definition of the class
613 // granting friendship.
614 // i.e. we don't push a scope unless it's a class member.
615
616 switch (Qualifier->getKind()) {
617 case NestedNameSpecifier::Global:
618 case NestedNameSpecifier::Namespace:
619 // These are always namespace scopes. We never want to enter a
620 // namespace scope from anything but a file context.
621 return CurContext->getLookupContext()->isFileContext();
622
623 case NestedNameSpecifier::Identifier:
624 case NestedNameSpecifier::TypeSpec:
625 case NestedNameSpecifier::TypeSpecWithTemplate:
626 // These are never namespace scopes.
627 return true;
628 }
629
630 // Silence bogus warning.
631 return false;
632}
633
Cedric Venet3d658642009-02-14 20:20:19 +0000634/// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global
635/// scope or nested-name-specifier) is parsed, part of a declarator-id.
636/// After this method is called, according to [C++ 3.4.3p3], names should be
637/// looked up in the declarator-id's scope, until the declarator is parsed and
638/// ActOnCXXExitDeclaratorScope is called.
639/// The 'SS' should be a non-empty valid CXXScopeSpec.
Jeffrey Yasskin9ab14542010-04-08 16:38:48 +0000640bool Sema::ActOnCXXEnterDeclaratorScope(Scope *S, CXXScopeSpec &SS) {
Cedric Venet3d658642009-02-14 20:20:19 +0000641 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec.");
John McCall7a1dc562009-12-19 10:49:29 +0000642
643 if (SS.isInvalid()) return true;
644
645 DeclContext *DC = computeDeclContext(SS, true);
646 if (!DC) return true;
647
648 // Before we enter a declarator's context, we need to make sure that
649 // it is a complete declaration context.
John McCall77bb1aa2010-05-01 00:40:08 +0000650 if (!DC->isDependentContext() && RequireCompleteDeclContext(SS, DC))
John McCall7a1dc562009-12-19 10:49:29 +0000651 return true;
652
653 EnterDeclaratorContext(S, DC);
John McCall31f17ec2010-04-27 00:57:59 +0000654
655 // Rebuild the nested name specifier for the new scope.
656 if (DC->isDependentContext())
657 RebuildNestedNameSpecifierInCurrentInstantiation(SS);
658
Douglas Gregor7dfd0fb2009-09-24 23:39:01 +0000659 return false;
Cedric Venet3d658642009-02-14 20:20:19 +0000660}
661
662/// ActOnCXXExitDeclaratorScope - Called when a declarator that previously
663/// invoked ActOnCXXEnterDeclaratorScope(), is finished. 'SS' is the same
664/// CXXScopeSpec that was passed to ActOnCXXEnterDeclaratorScope as well.
665/// Used to indicate that names should revert to being looked up in the
666/// defining scope.
667void Sema::ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS) {
668 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec.");
Douglas Gregordacd4342009-08-26 00:04:55 +0000669 if (SS.isInvalid())
670 return;
John McCall7a1dc562009-12-19 10:49:29 +0000671 assert(!SS.isInvalid() && computeDeclContext(SS, true) &&
672 "exiting declarator scope we never really entered");
673 ExitDeclaratorContext(S);
Cedric Venet3d658642009-02-14 20:20:19 +0000674}