Restore the invariant that a nested-name-specifier can only contain

class types, dependent types, and namespaces. I had previously
weakened this invariant while working on parsing pseudo-destructor
expressions, but recent work in that area has made these changes
unnecessary.

llvm-svn: 97112

6 files changed, 28 insertions, 70 deletions

diff --git a/clang/lib/Sema/Sema.h b/clang/lib/Sema/Sema.h
index 1bc084c5db3..2ed4bf6297a 100644
--- a/clang/lib/Sema/Sema.h
+++ b/clang/lib/Sema/Sema.h
@@ -2225,8 +2225,7 @@ public:
   virtual CXXScopeTy *ActOnCXXGlobalScopeSpecifier(Scope *S,
                                                    SourceLocation CCLoc);
 
-  bool isAcceptableNestedNameSpecifier(NamedDecl *SD, 
-                                       bool MayBePseudoDestructor = false);
+  bool isAcceptableNestedNameSpecifier(NamedDecl *SD);
   NamedDecl *FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS);
 
   virtual bool isNonTypeNestedNameSpecifier(Scope *S, const CXXScopeSpec &SS,
@@ -2239,7 +2238,6 @@ public:
                                           SourceLocation IdLoc,
                                           SourceLocation CCLoc,
                                           IdentifierInfo &II,
-                                          bool MayBePseudoDestructor,
                                           QualType ObjectType,
                                           NamedDecl *ScopeLookupResult,
                                           bool EnteringContext,
@@ -2250,14 +2248,12 @@ public:
                                                   SourceLocation IdLoc,
                                                   SourceLocation CCLoc,
                                                   IdentifierInfo &II,
-                                                  bool MayBePseudoDestructor,
                                                   TypeTy *ObjectType,
                                                   bool EnteringContext);
 
   virtual bool IsInvalidUnlessNestedName(Scope *S,
                                          const CXXScopeSpec &SS,
                                          IdentifierInfo &II,
-                                         bool MayBePseudoDestructor,
                                          TypeTy *ObjectType,
                                          bool EnteringContext);
   
@@ -2273,8 +2269,7 @@ public:
                                                   const CXXScopeSpec &SS,
                                                   TypeTy *Type,
                                                   SourceRange TypeRange,
-                                                  SourceLocation CCLoc,
-                                                  bool MayBePseudoDestructor);
+                                                  SourceLocation CCLoc);
 
   virtual bool ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS);
 
diff --git a/clang/lib/Sema/SemaCXXScopeSpec.cpp b/clang/lib/Sema/SemaCXXScopeSpec.cpp
index 4f8a41426c0..971b78c489e 100644
--- a/clang/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/clang/lib/Sema/SemaCXXScopeSpec.cpp
@@ -176,15 +176,16 @@ DeclContext *Sema::computeDeclContext(const CXXScopeSpec &SS,
 
   case NestedNameSpecifier::TypeSpec:
   case NestedNameSpecifier::TypeSpecWithTemplate: {
-    if (const TagType *Tag = NNS->getAsType()->getAs<TagType>())
-      return Tag->getDecl();
-    break;
-  } 
+    const TagType *Tag = NNS->getAsType()->getAs<TagType>();
+    assert(Tag && "Non-tag type in nested-name-specifier");
+    return Tag->getDecl();
+  } break;
 
   case NestedNameSpecifier::Global:
     return Context.getTranslationUnitDecl();
   }
 
+  // Required to silence a GCC warning.
   return 0;
 }
 
@@ -269,8 +270,7 @@ Sema::CXXScopeTy *Sema::ActOnCXXGlobalScopeSpecifier(Scope *S,
 
 /// \brief Determines whether the given declaration is an valid acceptable
 /// result for name lookup of a nested-name-specifier.
-bool Sema::isAcceptableNestedNameSpecifier(NamedDecl *SD,
-                                           bool MayBePseudoDestructor) {
+bool Sema::isAcceptableNestedNameSpecifier(NamedDecl *SD) {
   if (!SD)
     return false;
 
@@ -281,11 +281,6 @@ bool Sema::isAcceptableNestedNameSpecifier(NamedDecl *SD,
   if (!isa<TypeDecl>(SD))
     return false;
 
-  // If this may be part of a pseudo-destructor expression, we'll
-  // accept any type.
-  if (MayBePseudoDestructor)
-    return true;
-
   // Determine whether we have a class (or, in C++0x, an enum) or
   // a typedef thereof. If so, build the nested-name-specifier.
   QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD));
@@ -326,7 +321,7 @@ NamedDecl *Sema::FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS) {
     return 0;
 
   NamedDecl *Result = Found.getFoundDecl();
-  if (isAcceptableNestedNameSpecifier(Result, true))
+  if (isAcceptableNestedNameSpecifier(Result))
     return Result;
 
   return 0;
@@ -398,7 +393,6 @@ Sema::CXXScopeTy *Sema::BuildCXXNestedNameSpecifier(Scope *S,
                                                     SourceLocation IdLoc,
                                                     SourceLocation CCLoc,
                                                     IdentifierInfo &II,
-                                                    bool MayBePseudoDestructor,
                                                     QualType ObjectType,
                                                   NamedDecl *ScopeLookupResult,
                                                     bool EnteringContext,
@@ -493,8 +487,7 @@ Sema::CXXScopeTy *Sema::BuildCXXNestedNameSpecifier(Scope *S,
     DeclarationName Name = Found.getLookupName();
     if (CorrectTypo(Found, S, &SS, LookupCtx, EnteringContext) &&
         Found.isSingleResult() &&
-        isAcceptableNestedNameSpecifier(Found.getAsSingle<NamedDecl>(),
-                                        MayBePseudoDestructor)) {
+        isAcceptableNestedNameSpecifier(Found.getAsSingle<NamedDecl>())) {
       if (LookupCtx)
         Diag(Found.getNameLoc(), diag::err_no_member_suggest)
           << Name << LookupCtx << Found.getLookupName() << SS.getRange()
@@ -514,7 +507,7 @@ Sema::CXXScopeTy *Sema::BuildCXXNestedNameSpecifier(Scope *S,
   }
 
   NamedDecl *SD = Found.getAsSingle<NamedDecl>();
-  if (isAcceptableNestedNameSpecifier(SD, MayBePseudoDestructor)) {
+  if (isAcceptableNestedNameSpecifier(SD)) {
     if (!ObjectType.isNull() && !ObjectTypeSearchedInScope) {
       // C++ [basic.lookup.classref]p4:
       //   [...] If the name is found in both contexts, the
@@ -526,14 +519,13 @@ Sema::CXXScopeTy *Sema::BuildCXXNestedNameSpecifier(Scope *S,
       // scope, reconstruct the result from the template instantiation itself.
       NamedDecl *OuterDecl;
       if (S) {
-        LookupResult FoundOuter(*this, &II, IdLoc, 
-                                LookupNestedNameSpecifierName);
+        LookupResult FoundOuter(*this, &II, IdLoc, LookupNestedNameSpecifierName);
         LookupName(FoundOuter, S);
         OuterDecl = FoundOuter.getAsSingle<NamedDecl>();
       } else
         OuterDecl = ScopeLookupResult;
 
-      if (isAcceptableNestedNameSpecifier(OuterDecl, MayBePseudoDestructor) &&
+      if (isAcceptableNestedNameSpecifier(OuterDecl) &&
           OuterDecl->getCanonicalDecl() != SD->getCanonicalDecl() &&
           (!isa<TypeDecl>(OuterDecl) || !isa<TypeDecl>(SD) ||
            !Context.hasSameType(
@@ -610,11 +602,9 @@ Sema::CXXScopeTy *Sema::ActOnCXXNestedNameSpecifier(Scope *S,
                                                     SourceLocation IdLoc,
                                                     SourceLocation CCLoc,
                                                     IdentifierInfo &II,
-                                                    bool MayBePseudoDestructor,
                                                     TypeTy *ObjectTypePtr,
                                                     bool EnteringContext) {
   return BuildCXXNestedNameSpecifier(S, SS, IdLoc, CCLoc, II,
-                                     MayBePseudoDestructor,
                                      QualType::getFromOpaquePtr(ObjectTypePtr),
                                      /*ScopeLookupResult=*/0, EnteringContext,
                                      false);
@@ -627,13 +617,10 @@ Sema::CXXScopeTy *Sema::ActOnCXXNestedNameSpecifier(Scope *S,
 ///
 /// The arguments are the same as those passed to ActOnCXXNestedNameSpecifier.
 bool Sema::IsInvalidUnlessNestedName(Scope *S, const CXXScopeSpec &SS,
-                                     IdentifierInfo &II, 
-                                     bool MayBePseudoDestructor,
-                                     TypeTy *ObjectType,
+                                     IdentifierInfo &II, TypeTy *ObjectType,
                                      bool EnteringContext) {
   return BuildCXXNestedNameSpecifier(S, SS, SourceLocation(), SourceLocation(),
-                                     II, MayBePseudoDestructor,
-                                     QualType::getFromOpaquePtr(ObjectType),
+                                     II, QualType::getFromOpaquePtr(ObjectType),
                                      /*ScopeLookupResult=*/0, EnteringContext,
                                      true);
 }
@@ -642,8 +629,7 @@ Sema::CXXScopeTy *Sema::ActOnCXXNestedNameSpecifier(Scope *S,
                                                     const CXXScopeSpec &SS,
                                                     TypeTy *Ty,
                                                     SourceRange TypeRange,
-                                                    SourceLocation CCLoc,
-                                                  bool MayBePseudoDestructor) {
+                                                    SourceLocation CCLoc) {
   NestedNameSpecifier *Prefix
     = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
   QualType T = GetTypeFromParser(Ty);
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 64f2ef204e7..1a6fdd7e024 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -133,7 +133,7 @@ Action::TypeTy *Sema::getDestructorName(SourceLocation TildeLoc,
       isDependent = LookupCtx && LookupCtx->isDependentContext();
     }
     
-    LookInScope = (LookupCtx == 0) && !isDependent;
+    LookInScope = false;
   } else if (ObjectTypePtr) {
     // C++ [basic.lookup.classref]p3:
     //   If the unqualified-id is ~type-name, the type-name is looked up
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 0d5c50ab1be..c98f88f86aa 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -4925,7 +4925,6 @@ CurrentInstantiationRebuilder::TransformTypenameType(TypeLocBuilder &TLB,
   NestedNameSpecifier *NNS
     = TransformNestedNameSpecifier(T->getQualifier(),
                                    /*FIXME:*/SourceRange(getBaseLocation()),
-                                   false,
                                    ObjectType);
   if (!NNS)
     return QualType();
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index b6ddc463474..f12c559ec16 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -1486,7 +1486,7 @@ Sema::SubstNestedNameSpecifier(NestedNameSpecifier *NNS,
                          const MultiLevelTemplateArgumentList &TemplateArgs) {
   TemplateInstantiator Instantiator(*this, TemplateArgs, Range.getBegin(),
                                     DeclarationName());
-  return Instantiator.TransformNestedNameSpecifier(NNS, Range, false);
+  return Instantiator.TransformNestedNameSpecifier(NNS, Range);
 }
 
 TemplateName
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 416f480e577..a972572c94c 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -265,7 +265,6 @@ public:
   /// alternate behavior.
   NestedNameSpecifier *TransformNestedNameSpecifier(NestedNameSpecifier *NNS,
                                                     SourceRange Range,
-                                                    bool MayBePseudoDestructor,
                                               QualType ObjectType = QualType(),
                                           NamedDecl *FirstQualifierInScope = 0);
 
@@ -556,7 +555,6 @@ public:
   NestedNameSpecifier *RebuildNestedNameSpecifier(NestedNameSpecifier *Prefix,
                                                   SourceRange Range,
                                                   IdentifierInfo &II,
-                                                  bool MayBePseudoDestructor,
                                                   QualType ObjectType,
                                               NamedDecl *FirstQualifierInScope);
 
@@ -579,8 +577,7 @@ public:
   NestedNameSpecifier *RebuildNestedNameSpecifier(NestedNameSpecifier *Prefix,
                                                   SourceRange Range,
                                                   bool TemplateKW,
-                                                  QualType T,
-                                                  bool MayBePseudoDestructor);
+                                                  QualType T);
 
   /// \brief Build a new template name given a nested name specifier, a flag
   /// indicating whether the "template" keyword was provided, and the template
@@ -1712,7 +1709,6 @@ template<typename Derived>
 NestedNameSpecifier *
 TreeTransform<Derived>::TransformNestedNameSpecifier(NestedNameSpecifier *NNS,
                                                      SourceRange Range,
-                                                     bool MayBePseudoDestructor,
                                                      QualType ObjectType,
                                              NamedDecl *FirstQualifierInScope) {
   if (!NNS)
@@ -1722,7 +1718,6 @@ TreeTransform<Derived>::TransformNestedNameSpecifier(NestedNameSpecifier *NNS,
   NestedNameSpecifier *Prefix = NNS->getPrefix();
   if (Prefix) {
     Prefix = getDerived().TransformNestedNameSpecifier(Prefix, Range,
-                                                       false,
                                                        ObjectType,
                                                        FirstQualifierInScope);
     if (!Prefix)
@@ -1744,7 +1739,6 @@ TreeTransform<Derived>::TransformNestedNameSpecifier(NestedNameSpecifier *NNS,
 
     return getDerived().RebuildNestedNameSpecifier(Prefix, Range,
                                                    *NNS->getAsIdentifier(),
-                                                   MayBePseudoDestructor,
                                                    ObjectType,
                                                    FirstQualifierInScope);
 
@@ -1780,8 +1774,7 @@ TreeTransform<Derived>::TransformNestedNameSpecifier(NestedNameSpecifier *NNS,
 
     return getDerived().RebuildNestedNameSpecifier(Prefix, Range,
                   NNS->getKind() == NestedNameSpecifier::TypeSpecWithTemplate,
-                                                   T,
-                                                   MayBePseudoDestructor);
+                                                   T);
   }
   }
 
@@ -1833,7 +1826,6 @@ TreeTransform<Derived>::TransformTemplateName(TemplateName Name,
     NestedNameSpecifier *NNS
       = getDerived().TransformNestedNameSpecifier(QTN->getQualifier(),
                         /*FIXME:*/SourceRange(getDerived().getBaseLocation()),
-                                                  false,
                                                   ObjectType);
     if (!NNS)
       return TemplateName();
@@ -1861,7 +1853,6 @@ TreeTransform<Derived>::TransformTemplateName(TemplateName Name,
     NestedNameSpecifier *NNS
       = getDerived().TransformNestedNameSpecifier(DTN->getQualifier(),
                         /*FIXME:*/SourceRange(getDerived().getBaseLocation()),
-                                                  false,
                                                   ObjectType);
     if (!NNS && DTN->getQualifier())
       return TemplateName();
@@ -2921,7 +2912,6 @@ TreeTransform<Derived>::TransformQualifiedNameType(TypeLocBuilder &TLB,
   NestedNameSpecifier *NNS
     = getDerived().TransformNestedNameSpecifier(T->getQualifier(),
                                                 SourceRange(),
-                                                false,
                                                 ObjectType);
   if (!NNS)
     return QualType();
@@ -2956,7 +2946,7 @@ QualType TreeTransform<Derived>::TransformTypenameType(TypeLocBuilder &TLB,
 
   NestedNameSpecifier *NNS
     = getDerived().TransformNestedNameSpecifier(T->getQualifier(), SR,
-                                                false, ObjectType);
+                                                ObjectType);
   if (!NNS)
     return QualType();
 
@@ -3592,8 +3582,7 @@ TreeTransform<Derived>::TransformDeclRefExpr(DeclRefExpr *E) {
   NestedNameSpecifier *Qualifier = 0;
   if (E->getQualifier()) {
     Qualifier = getDerived().TransformNestedNameSpecifier(E->getQualifier(),
-                                                        E->getQualifierRange(),
-                                                          false);
+                                                       E->getQualifierRange());
     if (!Qualifier)
       return SemaRef.ExprError();
   }
@@ -3802,8 +3791,7 @@ TreeTransform<Derived>::TransformMemberExpr(MemberExpr *E) {
   if (E->hasQualifier()) {
     Qualifier
       = getDerived().TransformNestedNameSpecifier(E->getQualifier(),
-                                                  E->getQualifierRange(),
-                                                  false);
+                                                  E->getQualifierRange());
     if (Qualifier == 0)
       return SemaRef.ExprError();
   }
@@ -4685,7 +4673,6 @@ TreeTransform<Derived>::TransformCXXPseudoDestructorExpr(
   NestedNameSpecifier *Qualifier
     = getDerived().TransformNestedNameSpecifier(E->getQualifier(),
                                                 E->getQualifierRange(),
-                                                true,
                                                 ObjectType);
   if (E->getQualifier() && !Qualifier)
     return SemaRef.ExprError();
@@ -4786,8 +4773,7 @@ TreeTransform<Derived>::TransformUnresolvedLookupExpr(
   NestedNameSpecifier *Qualifier = 0;
   if (Old->getQualifier()) {
     Qualifier = getDerived().TransformNestedNameSpecifier(Old->getQualifier(),
-                                                       Old->getQualifierRange(),
-                                                          false);
+                                                    Old->getQualifierRange());
     if (!Qualifier)
       return SemaRef.ExprError();
     
@@ -4843,8 +4829,7 @@ TreeTransform<Derived>::TransformDependentScopeDeclRefExpr(
                                                   DependentScopeDeclRefExpr *E) {
   NestedNameSpecifier *NNS
     = getDerived().TransformNestedNameSpecifier(E->getQualifier(),
-                                                E->getQualifierRange(),
-                                                false);
+                                                E->getQualifierRange());
   if (!NNS)
     return SemaRef.ExprError();
 
@@ -5093,11 +5078,8 @@ TreeTransform<Derived>::TransformCXXDependentScopeMemberExpr(
 
   NestedNameSpecifier *Qualifier = 0;
   if (E->getQualifier()) {
-    bool MayBePseudoDestructor
-      = E->getMember().getNameKind() == DeclarationName::CXXDestructorName;
     Qualifier = getDerived().TransformNestedNameSpecifier(E->getQualifier(),
                                                       E->getQualifierRange(),
-                                                          MayBePseudoDestructor,
                                                       ObjectType,
                                                       FirstQualifierInScope);
     if (!Qualifier)
@@ -5172,8 +5154,7 @@ TreeTransform<Derived>::TransformUnresolvedMemberExpr(UnresolvedMemberExpr *Old)
   if (Old->getQualifier()) {
     Qualifier
       = getDerived().TransformNestedNameSpecifier(Old->getQualifier(),
-                                                  Old->getQualifierRange(),
-                                                  false);
+                                                  Old->getQualifierRange());
     if (Qualifier == 0)
       return SemaRef.ExprError();
   }
@@ -5598,7 +5579,6 @@ NestedNameSpecifier *
 TreeTransform<Derived>::RebuildNestedNameSpecifier(NestedNameSpecifier *Prefix,
                                                    SourceRange Range,
                                                    IdentifierInfo &II,
-                                                   bool MayBePseudoDestructor,
                                                    QualType ObjectType,
                                                    NamedDecl *FirstQualifierInScope) {
   CXXScopeSpec SS;
@@ -5608,7 +5588,6 @@ TreeTransform<Derived>::RebuildNestedNameSpecifier(NestedNameSpecifier *Prefix,
   return static_cast<NestedNameSpecifier *>(
                     SemaRef.BuildCXXNestedNameSpecifier(0, SS, Range.getEnd(),
                                                         Range.getEnd(), II,
-                                                        MayBePseudoDestructor,
                                                         ObjectType,
                                                         FirstQualifierInScope,
                                                         false, false));
@@ -5627,9 +5606,8 @@ NestedNameSpecifier *
 TreeTransform<Derived>::RebuildNestedNameSpecifier(NestedNameSpecifier *Prefix,
                                                    SourceRange Range,
                                                    bool TemplateKW,
-                                                   QualType T,
-                                                   bool MayBePseudoDestructor) {
-  if (MayBePseudoDestructor || T->isDependentType() || T->isRecordType() ||
+                                                   QualType T) {
+  if (T->isDependentType() || T->isRecordType() ||
       (SemaRef.getLangOptions().CPlusPlus0x && T->isEnumeralType())) {
     assert(!T.hasLocalQualifiers() && "Can't get cv-qualifiers here");
     return NestedNameSpecifier::Create(SemaRef.Context, Prefix, TemplateKW,