re PR middle-end/59338 (error: position plus size exceeds size of referenced…

re PR middle-end/59338 (error: position plus size exceeds size of referenced object in BIT_FIELD_REF)

2013-11-29  Richard Biener  <rguenther@suse.de>

	PR middle-end/59338
	* tree-cfg.c (verify_expr): Restrict bounds verification of
	BIT_FIELD_REF arguments to non-aggregate typed base objects.

	* gcc.dg/torture/pr59338.c: New testcase.

From-SVN: r205521

gcc/ChangeLog

 2013-11-29  Richard Biener  <rguenther@suse.de>
 
+	PR middle-end/59338
+	* tree-cfg.c (verify_expr): Restrict bounds verification of
+	BIT_FIELD_REF arguments to non-aggregate typed base objects.
+
+2013-11-29  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/59334
 	* tree-ssa-dce.c (eliminate_unnecessary_stmts): Fix bug
 	in previous commit.

gcc/testsuite/ChangeLog

+2013-11-29  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/59338
+	* gcc.dg/torture/pr59338.c: New testcase.
+
 2013-11-29  Jakub Jelinek  <jakub@redhat.com>
 
 	PR lto/59326

gcc/testsuite/gcc.dg/torture/pr59338.c

+/* { dg-do compile } */
+
+typedef enum
+{
+  XYZZY,
+} enumType;
+
+typedef struct
+{
+  unsigned char More : 1;
+} tResp;
+
+typedef struct
+{
+  enumType QueryType;
+  union
+    {
+      tResp l[0];
+    } u;
+} tQResp;
+
+void test(void)
+{
+  tQResp *qResp = (0);
+  if (qResp->u.l[0].More == 0)
+    return;
+}

gcc/tree-cfg.c

@@ -2715,17 +2715,6 @@ verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
 	  tree t0 = TREE_OPERAND (t, 0);
 	  tree t1 = TREE_OPERAND (t, 1);
 	  tree t2 = TREE_OPERAND (t, 2);
-	  tree t0_type = TREE_TYPE (t0);
-	  unsigned HOST_WIDE_INT t0_size = 0;
-
-	  if (tree_fits_uhwi_p (TYPE_SIZE (t0_type)))
-	    t0_size = tree_to_uhwi (TYPE_SIZE (t0_type));
-	  else 
-	    {
-	      HOST_WIDE_INT t0_max_size = max_int_size_in_bytes (t0_type);
-	      if (t0_max_size > 0)
-		t0_size = t0_max_size * BITS_PER_UNIT;
-	    }
 	  if (!tree_fits_uhwi_p (t1)
 	      || !tree_fits_uhwi_p (t2))
 	    {
@@ -2749,8 +2738,9 @@ verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
 		     "match field size of BIT_FIELD_REF");
 	      return t;
 	    }
-	  if (t0_size != 0
-	      && tree_to_uhwi (t1) + tree_to_uhwi (t2) > t0_size)
+	  if (!AGGREGATE_TYPE_P (TREE_TYPE (t0))
+	      && (tree_to_uhwi (t1) + tree_to_uhwi (t2)
+		  > tree_to_uhwi (TYPE_SIZE (TREE_TYPE (t0)))))
 	    {
 	      error ("position plus size exceeds size of referenced object in "
 		     "BIT_FIELD_REF");