[COMMITTED] a68: fix layout of incomplete types

[Jose E. Marchesi]

Apparently there is some case where the c_union of an union may be
incomplete and the containing union complete.  At this point I don't
fully understand how is that possible and the layering out of modes
should probably be rethinked, but for now fix this corner case.

Signed-off-by: Jose E. Marchesi <jemarch@gnu.org>

gcc/algol68/ChangeLog

	* a68-low-moids.cc (a68_lower_moids): Fix for layout of
	incomplete types.
---
 gcc/algol68/a68-low-moids.cc | 35 ++++++++++++++++++++---------------
 1 file changed, 20 insertions(+), 15 deletions(-)

diff --git a/gcc/algol68/a68-low-moids.cc b/gcc/algol68/a68-low-moids.cc
index 4dbf1189162..b5bf46c8cf8 100644
--- a/gcc/algol68/a68-low-moids.cc
+++ b/gcc/algol68/a68-low-moids.cc
@@ -688,27 +688,32 @@ a68_lower_moids (MOID_T *mode)
 
   for (MOID_T *m = mode; m != NO_MOID; FORWARD (m))
     {
-      if (!COMPLETE_TYPE_P (CTYPE (m)))
+      if (IS_UNION (m))
 	{
-	  if (IS_STRUCT (m))
+	  tree union_type = CTYPE (m);
+	  tree c_union_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (union_type)));
+
+	  if (!COMPLETE_TYPE_P (c_union_type))
 	    {
-	      tree struct_type = CTYPE (m);
-	      layout_type (struct_type);
-	      compute_record_mode (struct_type);
+	      layout_type (c_union_type);
+	      compute_record_mode (c_union_type);
+	      gcc_assert (COMPLETE_TYPE_P (c_union_type));
 	    }
-	  else if (IS_UNION (m))
-	    {
-	      tree union_type = CTYPE (m);
-	      tree c_union_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (union_type)));
-
-	      if (!COMPLETE_TYPE_P (c_union_type))
-		{
-		  layout_type (c_union_type);
-		  compute_record_mode (c_union_type);
-		}
 
+	  if (!COMPLETE_TYPE_P (union_type))
+	    {
 	      layout_type (union_type);
 	      compute_record_mode (union_type);
+	      gcc_assert (COMPLETE_TYPE_P (union_type));
+	    }
+	}
+      else if (!COMPLETE_TYPE_P (CTYPE (m)))
+	{
+	  if (IS_STRUCT (m))
+	    {
+	      tree struct_type = CTYPE (m);
+	      layout_type (struct_type);
+	      compute_record_mode (struct_type);
 	    }
 	  else
 	    layout_type (CTYPE (m));
-- 
2.30.2