2019-08-30  Jakub Jelinek  <jakub@redhat.com>

	Backported from mainline
	2019-06-21  Jakub Jelinek  <jakub@redhat.com>

	PR c++/90950
	* semantics.c (finish_omp_clauses): Don't reject references to
	incomplete types if processing_template_decl.

	* g++.dg/gomp/lastprivate-1.C: New test.

--- gcc/cp/semantics.c	(revision 272800)
+++ gcc/cp/semantics.c	(revision 272801)
@@ -7315,7 +7315,8 @@ finish_omp_clauses (tree clauses, enum c
 	  t = require_complete_type (t);
 	  if (t == error_mark_node)
 	    remove = true;
-	  else if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE
+	  else if (!processing_template_decl
+		   && TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE
 		   && !complete_type_or_else (TREE_TYPE (TREE_TYPE (t)), t))
 	    remove = true;
 	}
--- gcc/testsuite/g++.dg/gomp/lastprivate-1.C	(nonexistent)
+++ gcc/testsuite/g++.dg/gomp/lastprivate-1.C	(revision 272801)
@@ -0,0 +1,16 @@
+// PR c++/90950
+// { dg-do compile }
+
+template <typename T>
+T
+foo (void)
+{
+  T y = 0;
+  T &x = y;
+  #pragma omp parallel for lastprivate (x)
+  for (int i = 0; i < 8; ++i)
+    x = i;
+  return x;
+}
+
+int a = foo<int> ();