[Bug tree-optimization/24172] [4.1 Regression] error: incorrect sharing of tree nodes

["hubicka at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #13 from hubicka at gcc dot gnu dot org  2005-10-27 21:18 -------
This is patch I am testing to prevent the sharing.  I think it is good idea in
addition to Richard's patch to make fold do it's job too:

void IOException( char);
inline int* dummy( const char* const mode )
{
  IOException(*mode+*mode);
}

void prepare_inpaint( )
{
  dummy ("rb");
}


Index: tree-inline.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-inline.c,v
retrieving revision 1.212
diff -c -3 -p -r1.212 tree-inline.c
*** tree-inline.c       12 Oct 2005 23:34:09 -0000      1.212
--- tree-inline.c       27 Oct 2005 21:16:34 -0000
*************** copy_body_r (tree *tp, int *walk_subtree
*** 639,644 ****
--- 639,645 ----
          n = splay_tree_lookup (id->decl_map, (splay_tree_key) decl);
          if (n)
            {
+             tree new;
              /* If we happen to get an ADDR_EXPR in n->value, strip
                 it manually here as we'll eventually get ADDR_EXPRs
                 which lie about their types pointed to.  In this case
*************** copy_body_r (tree *tp, int *walk_subtree
*** 646,658 ****
                 but we absolutely rely on that.  As fold_indirect_ref
                 does other useful transformations, try that first, though.  */
              tree type = TREE_TYPE (TREE_TYPE ((tree)n->value));
!             *tp = fold_indirect_ref_1 (type, (tree)n->value);
              if (! *tp)
                {
!                 if (TREE_CODE ((tree)n->value) == ADDR_EXPR)
!                   *tp = TREE_OPERAND ((tree)n->value, 0);
                  else
!                   *tp = build1 (INDIRECT_REF, type, (tree)n->value);
                }
              *walk_subtrees = 0;
              return NULL;
--- 647,660 ----
                 but we absolutely rely on that.  As fold_indirect_ref
                 does other useful transformations, try that first, though.  */
              tree type = TREE_TYPE (TREE_TYPE ((tree)n->value));
!             new = unshare_expr ((tree)n->value);
!             *tp = fold_indirect_ref_1 (type, new);
              if (! *tp)
                {
!                 if (TREE_CODE (new) == ADDR_EXPR)
!                   *tp = TREE_OPERAND (new, 0);
                  else
!                   *tp = build1 (INDIRECT_REF, type, new);
                }
              *walk_subtrees = 0;
              return NULL;


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24172