c++: Fix template parm ICE [PR 98297]

I think this is nonsense code, we seem to be naming an instantiation
of a template template parm.  But this fixes the ICE.  Perhaps we
should diagnose the issue earlier?

	gcc/cp/
	* parser.c (cp_parser_elaborated_type_specifier): Test
	BOUND_TEMPLATE_TEMPLATE_PARM before checking for instantiation.
	gcc/testsuite/
	* g++.dg/template/pr98297.C: New.

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 7ea8c28830ea11f3fdcfb6f5cc64213e296a77e7..3883339aa642488930fbd6a376adcd378a7bb19d 100644 (file)
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -19650,7 +19650,9 @@ cp_parser_elaborated_type_specifier (cp_parser* parser,
       if (TREE_CODE (type) == TYPENAME_TYPE)
        warning (OPT_Wattributes,
                 "attributes ignored on uninstantiated type");
-      else if (tag_type != enum_type && CLASSTYPE_TEMPLATE_INSTANTIATION (type)
+      else if (tag_type != enum_type
+              && TREE_CODE (type) != BOUND_TEMPLATE_TEMPLATE_PARM
+              && CLASSTYPE_TEMPLATE_INSTANTIATION (type)
               && ! processing_explicit_instantiation)
        warning (OPT_Wattributes,
                 "attributes ignored on template instantiation");

diff --git a/gcc/testsuite/g++.dg/template/pr98297.C b/gcc/testsuite/g++.dg/template/pr98297.C
new file mode 100644 (file)
index 0000000..0dd63a5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/pr98297.C
@@ -0,0 +1,6 @@
+// PR 98297, ICE
+// { dg-do compile { target c++11 } }
+template <template <class> class a>
+struct [[b]]
+a <int>; // { dg-error "does not declare anything" }
+// { dg-warning "ignored" "" { target *-*-* } .-1 }