Implement parsing of nested-name-specifiers that involve template-ids, e.g.,

  std::vector<int>::allocator_type

When we parse a template-id that names a type, it will become either a
template-id annotation (which is a parsed representation of a
template-id that has not yet been through semantic analysis) or a
typename annotation (where semantic analysis has resolved the
template-id to an actual type), depending on the context. We only
produce a type in contexts where we know that we only need type
information, e.g., in a type specifier. Otherwise, we create a
template-id annotation that can later be "upgraded" by transforming it
into a typename annotation when the parser needs a type. This occurs,
for example, when we've parsed "std::vector<int>" above and then see
the '::' after it. However, it means that when writing something like
this:

  template<> class Outer::Inner<int> { ... };

We have two tokens to represent Outer::Inner<int>: one token for the
nested name specifier Outer::, and one template-id annotation token
for Inner<int>, which will be passed to semantic analysis to define
the class template specialization.

Most of the churn in the template tests in this patch come from an
improvement in our error recovery from ill-formed template-ids.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@65467 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/InternalsManual.html b/docs/InternalsManual.html
index 7b6d201..9250fd1 100644
--- a/docs/InternalsManual.html
+++ b/docs/InternalsManual.html
@@ -628,12 +628,10 @@
 Action::ActOnCXXNestedNameSpecifier callbacks.  In the case of Sema, this is a
 <tt>DeclContext*</tt>.</li>
 
-<li><b>tok::annot_template_id</b>: This annotation token represents a C++
-template-id such as "foo&lt;int, 4&gt;", which may refer to a function or type
-depending on whether foo is a function template or class template.  The
-AnnotationValue pointer is a pointer to a malloc'd TemplateIdAnnotation object.
-FIXME: I don't think the parsing logic is right for this.  Shouldn't type
-templates be turned into annot_typename??</li>
+<li><b>tok::annot_template_id</b>: This annotation token represents a
+C++ template-id such as "foo&lt;int, 4&gt;", where "foo" is the name
+of a template. The AnnotationValue pointer is a pointer to a malloc'd
+TemplateIdAnnotation object. Depending on the context, a parsed template-id that names a type might become a typename annotation token (if all we care about is the named type, e.g., because it occurs in a type specifier) or might remain a template-id token (if we want to retain more source location information or produce a new type, e.g., in a declaration of a class template specialization). template-id annotation tokens that refer to a type can be "upgraded" to typename annotation tokens by the parser.</li>
 
 </ol>