re PR middle-end/51077 (Endless recursion with __builtin_object_size)

	PR middle-end/51077
	* tree-object-size.c (addr_object_size): Check TREE_CODE of
	MEM_REF's operand rather than code of the MEM_REF itself.

	* gcc.c-torture/compile/pr51077.c: New test.

From-SVN: r181263

gcc/ChangeLog

+2011-11-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/51077
+	* tree-object-size.c (addr_object_size): Check TREE_CODE of
+	MEM_REF's operand rather than code of the MEM_REF itself.
+
 2011-11-10  Andrew MacLeod  <amacleod@redhat.com>
 
 	PR rtl-optimization/51040

gcc/testsuite/ChangeLog

 2011-11-10  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/51077
+	* gcc.c-torture/compile/pr51077.c: New test.
+
 	PR rtl-optimization/51023
 	* gcc.c-torture/execute/pr51023.c: New test.
 

gcc/testsuite/gcc.c-torture/compile/pr51077.c

+/* PR middle-end/51077 */
+
+struct S { unsigned char s, t[256]; };
+
+void
+foo (const struct S *x, struct S *y, int z)
+{
+  int i;
+  for (i = 0; i < 8; i++)
+    {
+      const struct S *a = &x[i];
+      __builtin___memcpy_chk (y->t, a->t, z, __builtin_object_size (y->t, 0));
+      y = (struct S *) &y->t[z];
+    }
+}

gcc/tree-object-size.c

@@ -175,7 +175,7 @@ addr_object_size (struct object_size_info *osi, const_tree ptr,
       unsigned HOST_WIDE_INT sz;
 
       if (!osi || (object_size_type & 1) != 0
-	  || TREE_CODE (pt_var) != SSA_NAME)
+	  || TREE_CODE (TREE_OPERAND (pt_var, 0)) != SSA_NAME)
 	{
 	  sz = compute_builtin_object_size (TREE_OPERAND (pt_var, 0),
 					    object_size_type & ~1);