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.

llvm-svn: 71756

1 files changed, 1 insertions, 1 deletions

diff --git a/clang/lib/Parse/ParseExprCXX.cpp b/clang/lib/Parse/ParseExprCXX.cpp
index 2f1b9c84d29..4becfc83c9c 100644
--- a/clang/lib/Parse/ParseExprCXX.cpp
+++ b/clang/lib/Parse/ParseExprCXX.cpp
@@ -149,7 +149,7 @@ bool Parser::ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS) {
       if (TemplateId->Kind == TNK_Type_template || 
           TemplateId->Kind == TNK_Dependent_template_name) {
         AnnotateTemplateIdTokenAsType(&SS);
-        SS.clear();
+        SS.setScopeRep(0);
 
         assert(Tok.is(tok::annot_typename) && 
                "AnnotateTemplateIdTokenAsType isn't working");