Re: [PATCH] Avoid depending on destructor order

[David Edelsohn <dje.gcc@gmail.com>]

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On Fri, Sep 23, 2022 at 9:38 AM Thomas Neumann <neumann@in.tum.de> wrote:

> > This patch broke bootstrap on AIX and probably other targets.
> >
> > #ifdef ATOMIC_FDE_FAST_PATH
> > #include "unwind-dw2-btree.h"
> >
> > static struct btree registered_frames;
> > static bool in_shutdown;
> > ...
> > #else
> >
> > in_shutdown only is defined for ATOMIC_FDE_FAST_PATH but used in code /
> > asserts not protected by that macro.
> >
> >    gcc_assert (in_shutdown || ob);
> >    return (void *) ob;
> > }
>
> I am sorry for that, I did not consider that my test machines all use
> the fast path.
>
> I think the problem can be fixed by the trivial patch below, I will
> commit that after I have tested builds both with and without fast path.
>
> Best
>
> Thomas
>
>
> diff --git a/libgcc/unwind-dw2-fde.c b/libgcc/unwind-dw2-fde.c
> index d237179f4ea..d6e347c5481 100644
> --- a/libgcc/unwind-dw2-fde.c
> +++ b/libgcc/unwind-dw2-fde.c
> @@ -67,6 +67,8 @@ static void
>   init_object (struct object *ob);
>
>   #else
> +/* Without fast path frame lookup must always succeed */
>
The comment should end with full stop and two spaces.


> +static const bool in_shutdown = false;
>
I'll let Jason or others decide if this is the right solution.  It seems
that in_shutdown also could be declared outside the #ifdef and initialized
as "false".

Thanks, David


>
>   /* The unseen_objects list contains objects that have been registered
>      but not yet categorized in any way.  The seen_objects list has had
>