[PATCH] Fix fold_stmt ICE (PR c++/49264)

[Jakub Jelinek]

On Mon, Jun 06, 2011 at 11:30:19AM +0200, Richard Guenther wrote:
> On Fri, Jun 3, 2011 at 3:55 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> > --- gcc/tree-inline.c.jj        2011-06-02 10:15:20.000000000 +0200
> > +++ gcc/tree-inline.c   2011-06-03 09:29:15.000000000 +0200
> > @@ -4108,6 +4108,14 @@ fold_marked_statements (int first, struc
> > Â  Â  Â  Â  Â  Â  Â  Â  Â if (fold_stmt (&gsi))
> > Â  Â  Â  Â  Â  Â  Â  Â  Â  Â {
> > Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â gimple new_stmt;
> > + Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  /* If a builtin at the end of a bb folded into nothing,
> > + Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â the following loop won't work. Â */
> > + Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  if (gsi_end_p (gsi))
> > + Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  {
> > + Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  cgraph_update_edges_for_call_stmt (old_stmt, old_decl,
> > + Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â gimple_build_nop ());
> 
> This?  Esp. I don't like the gimple_build_nop () here too much.

Yeah, I've talked about it in my patch comment.
E.g. cgraph_update_edges_for_call_stmt could accept NULL as new_stmt, or we
could add e.g.

void
cgraph_remove_edges_for_call_stmt (gimple old_stmt)
{
  struct cgraph_node *orig = cgraph_get_node (cfun->decl);
  struct cgraph_node *node;
  struct cgraph_edge *e;

  gcc_checking_assert (orig);
  e = cgraph_edge (orig, old_stmt);
  if (e)
    cgraph_remove_edge (e);
  if (orig->clones)
    for (node = orig->clones; node != orig; )
      {
	e = cgraph_edge (node, old_stmt);
	if (e)
	  cgraph_remove_edge (e);
	if (node->clones)
	  node = node->clones;
	else if (node->next_sibling_clone)
	  node = node->next_sibling_clone;
	else
	  {
	    while (node != orig && !node->next_sibling_clone)
	      node = node->clone_of;
	    if (node != orig)
	      node = node->next_sibling_clone;
	  }
      }
}

I think NULL new_stmt would have the advantage that we wouldn't duplicate
the complex code looping through all kinds of clones.

	Jakub