Re: abort() on Windows 2008 Server

[Eric Blake]

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According to Ramiro Polla on 10/18/2008 10:55 AM:

Hello Ramiro, and thanks for the report.

> Hello,
> 
> GNU m4 1.4.12 abort()s running on Windows 2008 Server. It doesn't go
> further than setting the signal handlers, so any call to m4.exe will
> fail. The problem does not occur with Windows XP. The build was made
> using MinGW gcc 4.2.4, mingw-runtime 3.15.1, w32api 3.12.
> 
> The reason:
> The loop at sigprocmask.c:197 tests signal() on all signals up to NSIG
> for SIG_ERR. On some version of Windows (I haven't checked which one,
> but it affects Windows 2008 Server), a new signal has been added. It
> is the SIGABRT_COMPAT signal, which is the same as SIGABRT [0]. So on
> that loop, signal() is called twice for the same signal.

Ouch.  This means gnulib has not yet been ported to this newer mingw setup.

> 
> The abort() on sigprocmask.c:218 has the comment:
> /* The application changed a signal handler while the signal
>    was blocked, bypassing our rpl_signal replacement.
>    We don't support this.  */
> 
> Actually you are changing it yourself. Once for signal 6 (which is the
> value of SIGABRT_COMPAT), and then again for 22 (SIGABRT).
> 
> Suggested ugly fix:
>  for (sig = 0; sig < NSIG; sig++)
>      if ((to_block >> sig) & 1)
>      {
>          pending_array[sig] = 0;
> +        if (sig == 6)
> +            continue;
>          if ((old_handlers[sig] = signal (sig, blocked_handler)) != SIG_ERR)
>              blocked_set |= 1U << sig;
>      }
>  }
> 
> Ugly hack, I know, not meant to be applied as is. I'm sure you'll have
> a better idea. MinGW still doesn't have a define for the new signal...
> 
> Ramiro Polla
> [0] http://msdn.microsoft.com/en-us/library/5s651ehs(VS.80).aspx

Thanks for the link.  I'm hoping developers more familiar with mingw will
help out here (in particular, Bruno helped write this module).  I
personally don't have access to a mingw system atop Windows 2008, so I
can't really do much testing; we may be relying on you for support.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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