Re: [RFC] Block all async signals used by gdb when initializing Guile

[Doug Evans <xdje42@gmail.com>]

On Sat, Aug 29, 2015 at 12:11 PM, Eli Zaretskii <eliz@gnu.org> wrote:
>> From: Doug Evans <xdje42@gmail.com>
>> cc: guile-devel@gnu.org
>> Date: Sat, 29 Aug 2015 10:22:11 -0700
>>
>> --- a/gdb/guile/guile.c
>> +++ b/gdb/guile/guile.c
>> @@ -847,7 +847,7 @@ _initialize_guile (void)
>>  #if HAVE_GUILE
>>    {
>>  #ifdef HAVE_SIGPROCMASK
>> -    sigset_t sigchld_mask, prev_mask;
>> +    sigset_t guile_init_mask, prev_mask;
>>  #endif
>>
>>      /* The Python support puts the C side in module "_gdb", leaving the Python
>> @@ -867,9 +867,23 @@ _initialize_guile (void)
>>         have SIGCHLD blocked.  PR 17247.
>>         Really libgc and Guile should do this, but we need to work with
>>         libgc 7.4.x.  */
>> -    sigemptyset (&sigchld_mask);
>> -    sigaddset (&sigchld_mask, SIGCHLD);
>> -    sigprocmask (SIG_BLOCK, &sigchld_mask, &prev_mask);
>> +    sigemptyset (&guile_init_mask);
>> +    sigaddset (&guile_init_mask, SIGCHLD);
>> +    /* Also block other asynchronous signals used by GDB.  See event-top.c.
>> +       Really we want to block every signal here except for those specifically
>> +       used by Guile (e.g., GC threads), but this is safer for now.  */
>> +    sigaddset (&guile_init_mask, SIGINT);
>> +    sigaddset (&guile_init_mask, SIGTERM);
>> +#ifdef SIGQUIT
>> +    sigaddset (&guile_init_mask, SIGQUIT);
>> +#endif
>> +#ifdef SIGHUP
>> +    sigaddset (&guile_init_mask, SIGHUP);
>> +#endif
>> +#ifdef SIGWINCH
>> +    sigaddset (&guile_init_mask, SIGWINCH);
>> +#endif
>> +    sigprocmask (SIG_BLOCK, &guile_init_mask, &prev_mask);
>>  #endif
>
> What about platforms that don't have sigprocmask, but do have SIGINT?
> Don't we want to block SIGINT on those platforms?

Do they have threads, and how does one block SIGINT on those platforms?