Re: scratch/igc 50f3a9309d8 1/3: scan_stack with __builtin_unwind_init

[Pip Cet <pipcet@protonmail.com>]

On Saturday, July 20th, 2024 at 07:41, Gerd Moellmann <gerd@gnu.org> wrote:
> branch: scratch/igc
> commit 50f3a9309d80c46c4d0b0b362ad65ef509c4d8ad
> Author: Gerd Möllmann gerd@gnu.org
> 
> Commit: Gerd Möllmann gerd@gnu.org
> 
> 
> scan_stack with __builtin_unwind_init
> ---
> src/igc.c | 20 +++++++++++++++++++-
> 1 file changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/src/igc.c b/src/igc.c
> index 9298cae66db..e63b796997a 100644
> --- a/src/igc.c
> +++ b/src/igc.c
> @@ -1356,6 +1356,24 @@ scan_ambig (mps_ss_t ss, void *start, void *end, void *closure)
> return MPS_RES_OK;
> }
> 
> +static mps_res_t
> +scan_stack (mps_ss_t ss, void *start, void *end, void *closure)
> +{
> + MPS_SCAN_BEGIN (ss)
> + {
> +#ifdef HAVE___BUILTIN_UNWIND_INIT
> + __builtin_unwind_init ();
> + asm ("");
> + void *p;
> + start = min (start, (void *) &p);
> + end = max (end, (void *) &p);

That assumes we're scanning the current thread, right? It appears to break

(make-thread (lambda () (igc-collect)))

here...

By the way, I'm seeing weird errors when I compile with clang and -flto for Android. Can you check whether Apple clang maybe enables -flto for -O?

Pip