> On 18 Jan 2023, at 23:16, Ludovic Courtès <l...@gnu.org
> <mailto:l...@gnu.org>> wrote:
>
> Hi Daniel,
>
> lloda <ll...@sarc.name <mailto:ll...@sarc.name>> skribis:
>
>> .../libguile/threads.h:194:43: error: 'scm_i_current_thread' is defined with
>> tls model global-dynamic
>> 194 | SCM_INTERNAL SCM_THREAD_LOCAL scm_thread *scm_i_current_thread;
>> | ^
>> .../libguile/threads.c:357:30: note: previously defined here as local-dynamic
>> 357 | SCM_THREAD_LOCAL scm_thread *scm_i_current_thread = NULL;
>>
>> Simply repeating SCM_INTERNAL in the .c fixes it...
>
> The problem is that ‘SCM_INTERNAL’ is synonymous with ‘extern’, which
> makes no sense for a definition (threads.c:357), so rightfully GCC
> GNU/Linux rightfully complains:
>
> --8<---------------cut here---------------start------------->8---
> CC libguile_3.0_la-threads.lo
> threads.c:358:43: warning: 'scm_i_current_thread' initialized and declared
> 'extern'
> 358 | SCM_INTERNAL SCM_THREAD_LOCAL scm_thread *scm_i_current_thread = NULL;
> | ^~~~~~~~~~~~~~~~~~~~
> --8<---------------cut here---------------end--------------->8---
>
> It’s just a warning, but still not looking good.
Hi,
Agreed, I had the same warning on mac os. Looked like the least bad choice...
> Is there something else at play, such as a ‘-ftls-model’ flag being
> passed to GCC somehow (info “(gcc) Code Gen Options")?
>
> If not, should we have:
>
> #define SCM_THREAD_LOCAL \
> __thread __attribute__ ((__tls_model__ ("global-dynamic")))
>
> instead (info "(gcc) Common Variable Attributes")?
>
> Would that work with Clang?
>
> Ludo’.
I don't seem to have any such flags.
The attribute does fix the issue on mac os with gcc 12.
I hadn't tried clang before, but I did now, and clang 14 works fine with or
without the attribute. So the fix would only be for gcc.
Thanks
Daniel
