re PR c/8081 (ICE with variably sized types returned from nested functions)

2012-01-13  Richard Guenther  <rguenther@suse.de>

	PR middle-end/8081
	* gimplify.c (gimplify_modify_expr_rhs): For calls with a
	variable-sized result always use RSO.

	* gcc.dg/torture/pr8081.c: New testcase.

From-SVN: r183153

gcc/ChangeLog

+2012-01-13  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/8081
+	* gimplify.c (gimplify_modify_expr_rhs): For calls with a
+	variable-sized result always use RSO.
+
 2012-01-12  DJ Delorie  <dj@redhat.com>
 
 	* cfgexpand.c (convert_debug_memory_address): Allow any valid

gcc/gimplify.c

@@ -4417,6 +4417,11 @@ gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p,
 		/* It's OK to use the target directly if it's being
 		   initialized. */
 		use_target = true;
+	      else if (variably_modified_type_p (TREE_TYPE (*to_p), NULL_TREE))
+		/* Always use the target and thus RSO for variable-sized types.
+		   GIMPLE cannot deal with a variable-sized assignment
+		   embedded in a call statement.  */
+		use_target = true;
 	      else if (TREE_CODE (*to_p) != SSA_NAME
 		      && (!is_gimple_variable (*to_p)
 			  || needs_to_live_in_memory (*to_p)))

gcc/testsuite/ChangeLog

+2012-01-13  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/8081
+	* gcc.dg/torture/pr8081.c: New testcase.
+
 2012-01-13  Georg-Johann Lay  <avr@gjlay.de>
 
 	* gcc.dg/pr46309.c: Set branch cost to greater 1 for avr.

gcc/testsuite/gcc.dg/torture/pr8081.c

+/* { dg-do run } */
+
+extern void abort (void);
+int
+main (int argc, char **argv)
+{
+  int size = 10;
+  typedef struct
+    {
+      char val[size];
+    }
+  block;
+  block a, b;
+  block __attribute__((noinline))
+  retframe_block ()
+    {
+      return *(block *) &b;
+    }
+  b.val[0] = -1;
+  b.val[9] = -2;
+  a=retframe_block ();
+  if (a.val[0] != -1
+      || a.val[9] != -2)
+    abort ();
+  return 0;
+}