Re: Support open-process and friends on MS-Windows

[Ludovic Courtès]

Eli Zaretskii <address@hidden> skribis:

> commit 44f8eebf9850431790b23b031f5b6e90fb3de777
> Author: Eli Zaretskii <address@hidden>
> Date:   Fri Jun 24 12:45:02 2016 +0300
>
>     Provide support for open-process and related functions on MS-Windows
>     
>     * libguile/w32-proc.c: New file, with MinGW support code for
>     scm_open_process, scm_getpriority, scm_setpriority,
>     scm_getaffinity, and scm_setaffinity.  Also, provides macros that
>     on Posix hosts are in sys/wait.h, like WIFEXITED and WTERMSIG, and
>     simple definitions for getuid, getgid, setuid, setgid, and
>     waitpid.

This is a good idea (I cannot comment on the content of w32-proc.c since
I’m not familiar with the Windows API, but I obviously trust you).

> diff --git a/libguile/posix.c b/libguile/posix.c
> index 2654716..35b920f 100644
> --- a/libguile/posix.c
> +++ b/libguile/posix.c
> @@ -84,6 +84,10 @@
>  #if HAVE_SYS_WAIT_H
>  # include <sys/wait.h>
>  #endif
> +#ifdef __MINGW32__
> +# include "w32-proc.c"
> +#endif       /* __MINGW32__ */

I’d have a slight preference for using AC_LIBSOURCE or a Makefile.am
snippet to compile w32-proc.c separately (which means w32-proc.h should
be added to provide declarations).

However this shouldn’t be a blocker (if the current approach is kept,
use <w32-proc.c> rather than "w32-proc.c").

> @@ -659,7 +663,7 @@ SCM_DEFINE (scm_kill, "kill", 2, 0, 0,
>  #else
>    /* Mingw has raise(), but not kill().  (Other raw DOS environments might
>       be similar.)  Use raise() when the requested pid is our own process,
> -     otherwise bomb.  */
> +     otherwise TerminateProcess.  */
>    if (scm_to_int (pid) == getpid ())
>      {
>        if (raise (scm_to_int (sig)) != 0)
> @@ -673,6 +677,25 @@ SCM_DEFINE (scm_kill, "kill", 2, 0, 0,
>            goto err;
>          }
>      }
> +#ifdef __MINGW32__
> +  else
> +    {
> +      HANDLE ph = OpenProcess (PROCESS_TERMINATE, 0, scm_to_int (pid));
> +      int s = scm_to_int (sig);
> +
> +      if (!ph)
> +     {
> +       errno = EPERM;
> +       goto err;
> +     }
> +      if (!TerminateProcess (ph, w32_signal_to_status (s)))
> +     {
> +       errno = EINVAL;
> +       goto err;
> +     }
> +      CloseHandle (ph);
> +    }
> +#endif       /* __MINGW32__ */
>  #endif
>    return SCM_UNSPECIFIED;

For consistency maybe this should go in a ‘kill’ function in w32-proc.c?

The rest looks good to me.

Thanks a lot for taking the time to update the patch, and for forgiving
our failure to handle it earlier.

Ludo’.