re PR tree-optimization/45919 (ICE: SIGSEGV in fold_ctor_reference (tree-ssa-ccp.c:1527) at -O1)

	PR tree-optimization/45919
	* tree-ssa-ccp.c (fold_nonarray_ctor_reference): Handle flexible
	array members.

	* gcc.c-torture/compile/pr45919.c: New test.

From-SVN: r165740

gcc/ChangeLog

 2010-10-20  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/45919
+	* tree-ssa-ccp.c (fold_nonarray_ctor_reference): Handle flexible
+	array members.
+
 	PR tree-optimization/46066
 	* tree-parloops.c (create_parallel_loop): Use gsi_last_nondebug_bb
 	instead of gsi_last_bb.

gcc/testsuite/ChangeLog

 2010-10-20  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/45919
+	* gcc.c-torture/compile/pr45919.c: New test.
+
 	PR tree-optimization/46066
 	* gcc.dg/autopar/pr46066.c: New test.
 

gcc/testsuite/gcc.c-torture/compile/pr45919.c

+/* PR tree-optimization/45919 */
+
+const struct S { int a; int b[]; } s = { 0, { 0 }};
+
+int
+foo (void)
+{
+  return s.b[0];
+}

gcc/tree-ssa-ccp.c

@@ -1523,23 +1523,30 @@ fold_nonarray_ctor_reference (tree type, tree ctor,
       double_int bits_per_unit_cst = uhwi_to_double_int (BITS_PER_UNIT);
       double_int bitoffset_end;
 
-      /* Variable sized objects in static constructors makes no sense.  */
+      /* Variable sized objects in static constructors makes no sense,
+	 but field_size can be NULL for flexible array members.  */
       gcc_assert (TREE_CODE (field_offset) == INTEGER_CST
 		  && TREE_CODE (byte_offset) == INTEGER_CST
-		  && TREE_CODE (field_size) == INTEGER_CST);
+		  && (field_size != NULL_TREE
+		      ? TREE_CODE (field_size) == INTEGER_CST
+		      : TREE_CODE (TREE_TYPE (cfield)) == ARRAY_TYPE));
 
       /* Compute bit offset of the field.  */
       bitoffset = double_int_add (tree_to_double_int (field_offset),
 				  double_int_mul (byte_offset_cst,
 						  bits_per_unit_cst));
       /* Compute bit offset where the field ends.  */
-      bitoffset_end = double_int_add (bitoffset,
-				      tree_to_double_int (field_size));
+      if (field_size != NULL_TREE)
+	bitoffset_end = double_int_add (bitoffset,
+					tree_to_double_int (field_size));
+      else
+	bitoffset_end = double_int_zero;
 
       /* Is OFFSET in the range (BITOFFSET, BITOFFSET_END)? */
       if (double_int_cmp (uhwi_to_double_int (offset), bitoffset, 0) >= 0
-	  && double_int_cmp (uhwi_to_double_int (offset),
-			     bitoffset_end, 0) < 0)
+	  && (field_size == NULL_TREE
+	      || double_int_cmp (uhwi_to_double_int (offset),
+				 bitoffset_end, 0) < 0))
 	{
 	  double_int access_end = double_int_add (uhwi_to_double_int (offset),
 						  uhwi_to_double_int (size));