tree-ssa-structalias.c (get_constraint_for_component_ref): Do not punt for STRING_CST.

	* tree-ssa-structalias.c (get_constraint_for_component_ref): Do not
	punt for STRING_CST.
	(get_constraint_for): Deal with STRING_CST here instead.

From-SVN: r134325

gcc/ChangeLog

+2008-04-15  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* tree-ssa-structalias.c (get_constraint_for_component_ref): Do not
+	punt for STRING_CST.
+	(get_constraint_for): Deal with STRING_CST here instead.
+
 2008-04-15  Richard Guenther  <rguenther@suse.de>
 
 	* tree-ssa-propagate.c (substitute_and_fold): Substitute

gcc/testsuite/ChangeLog

+2008-04-15  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/string_slice2.adb: New test.
+
 2008-04-15  Richard Guenther  <rguenther@suse.de>
 
 	* gcc.dg/fold-compare-2.c: Adjust testcase.

gcc/testsuite/gnat.dg/string_slice2.adb

+-- { dg-do compile }
+-- { dg-options "-O" }
+
+with Ada.Strings;
+with Ada.Strings.Fixed;
+
+procedure String_Slice2 is
+
+   package ASF renames Ada.Strings.Fixed;
+
+   Delete_String  : String(1..10);
+   Source_String2 : String(1..12) := "abcdefghijkl";
+
+begin
+
+   Delete_String := Source_String2(1..10);
+
+   ASF.Delete(Source  => Delete_String,
+              From    => 6,
+              Through => Delete_String'Last,
+              Justify => Ada.Strings.Left,
+              Pad     => 'x');
+
+end;

gcc/tree-ssa-structalias.c

@@ -2657,11 +2657,6 @@ get_constraint_for_component_ref (tree t, VEC(ce_s, heap) **results)
 
   t = get_ref_base_and_extent (t, &bitpos, &bitsize, &bitmaxsize);
 
-  /* String constants are readonly, so there is nothing to really do
-     here.  */
-  if (TREE_CODE (t) == STRING_CST)
-    return;
-
   get_constraint_for (t, results);
   result = VEC_last (ce_s, *results);
   result->offset = bitpos;
@@ -2779,6 +2774,16 @@ get_constraint_for (tree t, VEC (ce_s, heap) **results)
       return;
     }
 
+  /* String constants are read-only.  */
+  if (TREE_CODE (t) == STRING_CST)
+    {
+      temp.var = readonly_id;
+      temp.type = SCALAR;
+      temp.offset = 0;
+      VEC_safe_push (ce_s, heap, *results, &temp);
+      return;
+    }
+
   switch (TREE_CODE_CLASS (TREE_CODE (t)))
     {
     case tcc_expression: