re PR c++/84791 (ICE with broken OpenMP reduction clause)

	PR c++/84791
	* semantics.c (finish_omp_reduction_clause): If
	OMP_CLAUSE_REDUCTION_PLACEHOLDER is error_mark_node, return true
	even if processing_template_decl.

	* g++.dg/gomp/pr84791.C: New test.

From-SVN: r258981

gcc/cp/ChangeLog

+2018-03-30  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/84791
+	* semantics.c (finish_omp_reduction_clause): If
+	OMP_CLAUSE_REDUCTION_PLACEHOLDER is error_mark_node, return true
+	even if processing_template_decl.
+
 2018-03-29  David Malcolm  <dmalcolm@redhat.com>
 
 	PR c++/84269

gcc/cp/semantics.c

@@ -5623,7 +5623,11 @@ finish_omp_reduction_clause (tree c, bool *need_default_ctor, bool *need_dtor)
       return false;
     }
   else if (processing_template_decl)
-    return false;
+    {
+      if (OMP_CLAUSE_REDUCTION_PLACEHOLDER (c) == error_mark_node)
+	return true;
+      return false;
+    }
 
   tree id = OMP_CLAUSE_REDUCTION_PLACEHOLDER (c);
 

gcc/testsuite/ChangeLog

+2018-03-30  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/84791
+	* g++.dg/gomp/pr84791.C: New test.
+
 2018-03-30  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/84931

gcc/testsuite/g++.dg/gomp/pr84791.C

+// PR c++/84791
+// { dg-do compile }
+
+typedef int I;
+
+template <int>
+void
+foo ()
+{
+  I i;
+  #pragma omp parallel reduction (I::I: i)	// { dg-error "'I' is not a class, namespace, or enumeration" "" { target c++11 } }
+    ;						// { dg-error "'I' is not a class or namespace" "" { target c++98_only } .-1 }
+}
+
+template void foo<0> ();