Teach the type-id/expression disambiguator about different
disambiguation contexts, so that we properly parse template arguments
such as

  A<int()>

as type-ids rather than as expressions. Since this can be confusing
(especially when the template parameter is a non-type template
parameter), we try to give a friendly error message.

Almost, eliminate a redundant error message (that should have been a
note) and add some ultra-basic checks for non-type template
arguments.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64189 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 1a2da84..ecbc860 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -458,7 +458,7 @@
       // is an expression.
       Diag(ArgExpr->getSourceRange().getBegin(), 
            diag::err_template_arg_must_be_type);
-      Diag((*Param)->getLocation(), diag::note_template_parameter_here);
+      Diag((*Param)->getLocation(), diag::note_template_param_here);
       Invalid = true;
     } else if (NonTypeTemplateParmDecl *NTTP 
                  = dyn_cast<NonTypeTemplateParmDecl>(*Param)) {
@@ -484,7 +484,7 @@
           << ArgType;
       else
         Diag(ArgLoc, diag::err_template_arg_must_be_expr);
-      Diag((*Param)->getLocation(), diag::note_template_parameter_here);
+      Diag((*Param)->getLocation(), diag::note_template_param_here);
       Invalid = true;
     } else { 
       // Check template template parameters.