During template instantiation, set the naming class of

UnresolvedLookupExpr and UnresolvedMemberExpr by substituting the
naming class we computed when building the expression in the
template...

... which we didn't always do correctly. Teach
UnresolvedMemberExpr::getNamingClass() all about the new 
representation of injected-class-names in templates, so	that it	can
return a naming	class that is the current instantiation.

Also, when decomposing a template-id into its template name and its
arguments, be sure to set the naming class on the LookupResult
structure. 

Fixes PR6947 the right way.

llvm-svn: 102448

Author: DougGregor

clang/include/clang/AST/Type.h

@@ -923,6 +923,11 @@ class Type {
   const ObjCInterfaceType *getAsObjCQualifiedInterfaceType() const;
   const CXXRecordDecl *getCXXRecordDeclForPointerType() const;
 
+  /// \brief Retrieves the CXXRecordDecl that this type refers to, either
+  /// because the type is a RecordType or because it is the injected-class-name 
+  /// type of a class template or class template partial specialization.
+  CXXRecordDecl *getAsCXXRecordDecl() const;
+  
   // Member-template getAs<specific type>'.  This scheme will eventually
   // replace the specific getAsXXXX methods above.
   //

clang/lib/AST/ExprCXX.cpp

@@ -728,27 +728,27 @@ CXXRecordDecl *UnresolvedMemberExpr::getNamingClass() const {
   // If there was a nested name specifier, it names the naming class.
   // It can't be dependent: after all, we were actually able to do the
   // lookup.
-  const RecordType *RT;
+  CXXRecordDecl *Record = 0;
   if (getQualifier()) {
     Type *T = getQualifier()->getAsType();
     assert(T && "qualifier in member expression does not name type");
-    RT = T->getAs<RecordType>();
-    assert(RT && "qualifier in member expression does not name record");
-
+    Record = T->getAsCXXRecordDecl();
+    assert(Record && "qualifier in member expression does not name record");
+  }
   // Otherwise the naming class must have been the base class.
-  } else {
+  else {
     QualType BaseType = getBaseType().getNonReferenceType();
     if (isArrow()) {
       const PointerType *PT = BaseType->getAs<PointerType>();
       assert(PT && "base of arrow member access is not pointer");
       BaseType = PT->getPointeeType();
     }
 
-    RT = BaseType->getAs<RecordType>();
-    assert(RT && "base of member expression does not name record");
+    Record = BaseType->getAsCXXRecordDecl();
+    assert(Record && "base of member expression does not name record");
   }
 
-  return cast<CXXRecordDecl>(RT->getDecl());
+  return Record;
 }
 
 Stmt::child_iterator UnresolvedMemberExpr::child_begin() {

clang/lib/AST/Type.cpp

@@ -415,6 +415,16 @@ const CXXRecordDecl *Type::getCXXRecordDeclForPointerType() const {
   return 0;
 }
 
+CXXRecordDecl *Type::getAsCXXRecordDecl() const {
+  if (const RecordType *RT = getAs<RecordType>())
+    return dyn_cast<CXXRecordDecl>(RT->getDecl());
+  else if (const InjectedClassNameType *Injected
+                                  = getAs<InjectedClassNameType>())
+    return Injected->getDecl();
+  
+  return 0;
+}
+
 bool Type::isIntegerType() const {
   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
     return BT->getKind() >= BuiltinType::Bool &&

clang/lib/Sema/SemaExpr.cpp

@@ -1063,6 +1063,15 @@ Sema::OwningExprResult Sema::ActOnIdExpression(Scope *S,
   if (TemplateArgs) {
     // Just re-use the lookup done by isTemplateName.
     DecomposeTemplateName(R, Id);
+
+    // Re-derive the naming class.
+    if (SS.isSet()) {
+      NestedNameSpecifier *Qualifier
+        = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
+      if (const Type *Ty = Qualifier->getAsType())
+        if (CXXRecordDecl *NamingClass = Ty->getAsCXXRecordDecl())
+          R.setNamingClass(NamingClass);
+    }
   } else {
     bool IvarLookupFollowUp = (!SS.isSet() && II && getCurMethodDecl());
     LookupParsedName(R, S, &SS, !IvarLookupFollowUp);
@@ -3231,6 +3240,21 @@ Sema::OwningExprResult Sema::ActOnMemberAccessExpr(Scope *S, ExprArg BaseArg,
     if (TemplateArgs) {
       // Re-use the lookup done for the template name.
       DecomposeTemplateName(R, Id);
+      
+      // Re-derive the naming class.
+      if (SS.isSet()) {
+        NestedNameSpecifier *Qualifier
+        = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
+        if (const Type *Ty = Qualifier->getAsType())
+          if (CXXRecordDecl *NamingClass = Ty->getAsCXXRecordDecl())
+            R.setNamingClass(NamingClass);
+      } else {
+        QualType BaseType = Base->getType();
+        if (const PointerType *Ptr = BaseType->getAs<PointerType>())
+          BaseType = Ptr->getPointeeType();
+        if (CXXRecordDecl *NamingClass = BaseType->getAsCXXRecordDecl())
+          R.setNamingClass(NamingClass);
+      }
     } else {
       Result = LookupMemberExpr(R, Base, IsArrow, OpLoc,
                                 SS, ObjCImpDecl);

clang/lib/Sema/TreeTransform.h

@@ -5336,19 +5336,16 @@ TreeTransform<Derived>::TransformUnresolvedLookupExpr(
 
     SS.setScopeRep(Qualifier);
     SS.setRange(Old->getQualifierRange());
-    
-    // If this nested-name-specifier refers to a class type, that is the
-    // naming class.
-    if (const Type *NamedType = Qualifier->getAsType())
-      if (const RecordType *NamedRecord = NamedType->getAs<RecordType>())
-        R.setNamingClass(cast<CXXRecordDecl>(NamedRecord->getDecl()));
-  } else if (Old->getNamingClass()) {
+  } 
+  
+  if (Old->getNamingClass()) {
     CXXRecordDecl *NamingClass
       = cast_or_null<CXXRecordDecl>(getDerived().TransformDecl(
                                                             Old->getNameLoc(),
                                                         Old->getNamingClass()));
     if (!NamingClass)
       return SemaRef.ExprError();
+    
     R.setNamingClass(NamingClass);
   }
 
@@ -5735,20 +5732,13 @@ TreeTransform<Derived>::TransformUnresolvedMemberExpr(UnresolvedMemberExpr *Old)
     BaseType = getDerived().TransformType(Old->getBaseType());
   }
 
-  CXXRecordDecl *NamingClass = 0;
   NestedNameSpecifier *Qualifier = 0;
   if (Old->getQualifier()) {
     Qualifier
       = getDerived().TransformNestedNameSpecifier(Old->getQualifier(),
                                                   Old->getQualifierRange());
     if (Qualifier == 0)
       return SemaRef.ExprError();
-    
-    // If this nested-name-specifier refers to a class type, that is the
-    // naming class.
-    if (const Type *NamedType = Qualifier->getAsType())
-      if (const RecordType *NamedRecord = NamedType->getAs<RecordType>())
-        NamingClass = cast<CXXRecordDecl>(NamedRecord->getDecl());
   }
 
   LookupResult R(SemaRef, Old->getMemberName(), Old->getMemberLoc(),
@@ -5783,24 +5773,17 @@ TreeTransform<Derived>::TransformUnresolvedMemberExpr(UnresolvedMemberExpr *Old)
 
   R.resolveKind();
 
-  // Determine the naming class, if we haven't already.
-  if (!NamingClass) {
-    QualType T = BaseType;
-    if (const PointerType *PointerTy = T->getAs<PointerType>())
-      T = PointerTy->getPointeeType();
-    if (const RecordType *NamedRecord = T->getAs<RecordType>())
-      NamingClass = cast<CXXRecordDecl>(NamedRecord->getDecl());    
-  }
-  
-  if (!NamingClass && Old->getNamingClass()) {
-    NamingClass = cast_or_null<CXXRecordDecl>(getDerived().TransformDecl(
+  // Determine the naming class.
+  if (!Old->getNamingClass()) {
+    CXXRecordDecl *NamingClass 
+      = cast_or_null<CXXRecordDecl>(getDerived().TransformDecl(
                                                           Old->getMemberLoc(),
                                                         Old->getNamingClass()));
     if (!NamingClass)
       return SemaRef.ExprError();
-  }
-  if (NamingClass)
+    
     R.setNamingClass(NamingClass);
+  }
 
   TemplateArgumentListInfo TransArgs;
   if (Old->hasExplicitTemplateArgs()) {