Implement explicit instantiations of member classes of class templates, e.g.,

  template<typename T>
  struct X {
    struct Inner;
  };

  template struct X<int>::Inner;

This change is larger than it looks because it also fixes some
a problem with nested-name-specifiers and tags. We weren't requiring
the DeclContext associated with the scope specifier of a tag to be
complete. Therefore, when looking for something like "struct
X<int>::Inner", we weren't instantiating X<int>. 

This, naturally, uncovered a problem with member pointers, where we
were requiring the left-hand side of a member pointer access
expression (e.g., x->*) to be a complete type. However, this is wrong:
the semantics of this expression does not require a complete type (EDG
agrees).

Stuart vouched for me. Blame him.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@71756 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/Sema/SemaCXXScopeSpec.cpp b/lib/Sema/SemaCXXScopeSpec.cpp
index bbc1bc52cb..11ac0bd300 100644
--- a/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/lib/Sema/SemaCXXScopeSpec.cpp
@@ -273,8 +273,9 @@ Sema::CXXScopeTy *Sema::ActOnCXXNestedNameSpecifier(Scope *S,
                                                     SourceLocation CCLoc) {
   NestedNameSpecifier *Prefix 
     = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
+  QualType T = QualType::getFromOpaquePtr(Ty);
   return NestedNameSpecifier::Create(Context, Prefix, /*FIXME:*/false,
-                                QualType::getFromOpaquePtr(Ty).getTypePtr());
+                                     T.getTypePtr());
 }
 
 /// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global