Re: [PATCH] Handle undefined extern vars in output_in_order

[Jan Hubicka <hubicka@ucw.cz>]

> On Thu, 16 Jun 2016, Jan Hubicka wrote:
> > > On Thu, 9 Jun 2016, Alexander Monakov wrote:
> > +  FOR_EACH_VARIABLE (pv)
> [snip]
> > +      i = pv->order;
> > +      gcc_assert (nodes[i].kind == ORDER_UNDEFINED);
> > +      nodes[i].kind = pv->definition ? ORDER_VAR : ORDER_VAR_UNDEF;
> > +      nodes[i].u.v = pv;
> > 
> > order for undefined variables is not computed, so it will be 0. Doesn't
> > think overwrite existing entries of nodes array?
> 
> Hm, I've tried the following testcase:
> 
> extern int a, b;
> int f()
> {
>   return a+b;
> }
> 
> and in the above loop I see pv->order == 2 on the first iteration,
> pv->order == 1 on the second. Under what circumstances wouldn't
> order be computed?

I see, order is created at a time variable is added to symbol table (not at time when definition is given).
So we should have order everywhere.
Patch is OK

Honza
> 
> Thanks.
> Alexander