[PATCH] More PTA carefulness

[Richard Biener]

This adds two asserts that guards possible wrong-code issues in
get_constraint_for_ptr_offset.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.

Richard.

2014-03-11  Richard Biener  <rguent...@suse.de>

        * tree-ssa-structalias.c (get_constraint_for_ptr_offset):
        Add asserts to guard possible wrong-code bugs.

Index: gcc/tree-ssa-structalias.c
===================================================================
--- gcc/tree-ssa-structalias.c  (revision 208479)
+++ gcc/tree-ssa-structalias.c  (working copy)
@@ -3095,7 +3095,7 @@ get_constraint_for_ptr_offset (tree ptr,
       if (c.type == ADDRESSOF
          /* If this varinfo represents a full variable just use it.  */
          && curr->is_full_var)
-       c.offset = 0;
+       ;
       else if (c.type == ADDRESSOF
               /* If we do not know the offset add all subfields.  */
               && rhsoffset == UNKNOWN_OFFSET)
@@ -3143,8 +3143,14 @@ get_constraint_for_ptr_offset (tree ptr,
              temp = vi_next (temp);
            }
        }
+      else if (c.type == SCALAR)
+       {
+         gcc_assert (c.offset == 0);
+         c.offset = rhsoffset;
+       }
       else
-       c.offset = rhsoffset;
+       /* We shouldn't get any DEREFs here.  */
+       gcc_unreachable ();
 
       (*results)[j] = c;
     }