gimplify.c (gimplify_init_ctor_eval): Don't discard a zero-sized value if it has side-effects.

	* gimplify.c (gimplify_init_ctor_eval): Don't discard a zero-sized
	value if it has side-effects.

From-SVN: r104262

gcc/ChangeLog

+2005-09-14  Olivier Hainque  <hainque@adacore.com>
+
+	* gimplify.c (gimplify_init_ctor_eval): Don't discard a zero-sized
+	value if it has side-effects.
+
 2005-09-14  David Edelsohn  <edelsohn@gnu.org>
 
 	PR target/22068

gcc/gimplify.c

@@ -2576,7 +2576,12 @@ gimplify_init_ctor_eval (tree object, VEC(constructor_elt,gc) *elts,
 	 so we don't have to figure out what's missing ourselves.  */
       gcc_assert (purpose);
 
-      if (zero_sized_field_decl (purpose))
+      /* Skip zero-sized fields, unless value has side-effects.  This can
+	 happen with calls to functions returning a zero-sized type, which
+	 we shouldn't discard.  As a number of downstream passes don't
+	 expect sets of zero-sized fields, we rely on the gimplification of
+	 the MODIFY_EXPR we make below to drop the assignment statement.  */
+      if (! TREE_SIDE_EFFECTS (value) && zero_sized_field_decl (purpose))
 	continue;
 
       /* If we have a RANGE_EXPR, we have to build a loop to assign the