[PATCH] IPA: do not release body if still needed

[Jan Hubicka]

> Hi.
> 
> Noticed during building of libbackend.a with the LTO partial linking.
> 
> The function release_body is called even if clone_of is a clone
> of a another function and thus it shares tree declaration. We should
> preserve it in that situation.
> 
> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
> 
> Ready to be installed?
> Thanks,
> Martin
> 
> 	PR ipa/107944
> 
> gcc/ChangeLog:
> 
> 	* cgraph.cc (cgraph_node::remove): Do not release body
> 	if a node is clone of another node.
> ---
>  gcc/cgraph.cc | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/gcc/cgraph.cc b/gcc/cgraph.cc
> index f15cb47c8b8..2e7d77ffd6c 100644
> --- a/gcc/cgraph.cc
> +++ b/gcc/cgraph.cc
> @@ -1893,7 +1893,7 @@ cgraph_node::remove (void)
>    else if (clone_of)
>      {
>        clone_of->clones = next_sibling_clone;
> -      if (!clone_of->analyzed && !clone_of->clones && !clones)
> +      if (!clone_of->analyzed && !clone_of->clones && !clones && !clone_of->clone_of)
>  	clone_of->release_body ();

It is interesting that the problem reproduced only after almost 20
years.  But I suppose it is because we materialize clones in parituclar
order.

I think there are two ways to fix it.  Either declare release_body to be
applicable only to the master clone and avoid calling it here (as you
do) or make release_body do nothing when called on a clone.
I guess it makes sense to keep your approach but please add sanity check
to release_body that clone_of == NULL with a comment.

OK with that change.
Honza
>      }
>    if (next_sibling_clone)
> -- 
> 2.38.1
>