Re: [PATCH] Implement open-process and related functions on MinGW

[Mark H Weaver]

Eli Zaretskii <address@hidden> writes:

> This patch allows the MinGW build of Guile to have the process related
> functions (open-process, kill, waitpid, status:exit-val, etc.).
>
> Implement open-process and related functions on MinGW
>
> * libguile/filesys.c (fsync, link) [__MINGW32__]: Redirect Posix
>   functions to their Windows equivalents.

Gnulib has an 'fsync' module that apparently implements it on MinGW.
I think we should use that instead, no?

>   (scm_chown, scm_open_fdes, scm_open, scm_close, scm_close_fdes)
>   (scm_link, scm_chdir, set_element, fill_select_type)
>   (get_element, retrieve_select_type, scm_select, scm_fcntl)
>   (scm_fsync, scm_symlink, scm_readlink, scm_copy_file, scm_sendfile)
>   (scm_dir_print, scm_dir_free): These functions are no longer
>   wholesale ifdef'ed away if HAVE_POSIX is not defined.

As I wrote in my other recent message, I think we should simply
recommend that MinGW builds be done without "--disable-posix", since we
have at least one report that it works now.

>   (scm_init_filesys): Don't ifdef away parts of the function when
>   HAVE_POSIX is not defined.
>
> diff --git a/libguile/posix.c b/libguile/posix.c
> index 0443f95..69652a3 100644
> --- a/libguile/posix.c
> +++ b/libguile/posix.c
> @@ -85,6 +85,27 @@
>  #if HAVE_SYS_WAIT_H
>  # include <sys/wait.h>
>  #endif
> +#ifdef __MINGW32__
> +# define WEXITSTATUS(stat_val) ((stat_val) & 255)
> +/* Windows reports exit status from fatal exceptions as 0xC0000nnn
> +   codes, see winbase.h.  We usurp codes above 0xC0000200 for SIGxxx
> +   signals.  */
> +# define WIFEXITED(stat_val)   (((stat_val) & 0xC0000000) == 0)
> +# define WIFSIGNALED(stat_val) (((stat_val) & 0xC0000000) != 0)
> +# define WTERMSIG(stat_val)    ((stat_val > 0xC0000200) ? stat_val - 
> 0xC0000200 : stat_val)
> +# define WIFSTOPPED(stat_val)  (0)
> +# define WSTOPSIG(stat_var)    (0)
> +# include <process.h>
> +# define waitpid(p,s,o)        _cwait(s, p, WAIT_CHILD)
> +# define HAVE_WAITPID 1
> +# define getuid()              (500) /* Local Administrator */
> +# define getgid()              (513) /* None */
> +# define setuid(u)             (0)
> +# define setgid(g)             (0)
> +# define pipe(f)               _pipe(f, 0, O_NOINHERIT)
> +# define WIN32_LEAN_AND_MEAN
> +# include <windows.h>
> +#endif
>  #ifndef WEXITSTATUS
>  # define WEXITSTATUS(stat_val) ((unsigned)(stat_val) >> 8)
>  #endif
> @@ -674,6 +695,25 @@ 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, 0xC0000200 + s))
> +     {
> +       errno = EINVAL;
> +       goto err;
> +     }
> +      CloseHandle (ph);
> +    }
> +#endif       /* __MINGW32__ */
>  #endif
>    return SCM_UNSPECIFIED;
>  }
> @@ -720,6 +760,7 @@ SCM_DEFINE (scm_waitpid, "waitpid", 1, 1, 0,
>  {
>    int i;
>    int status;
> +#ifndef __MINGW32__
>    int ioptions;
>    if (SCM_UNBNDP (options))
>      ioptions = 0;
> @@ -728,6 +769,7 @@ SCM_DEFINE (scm_waitpid, "waitpid", 1, 1, 0,
>        /* Flags are interned in scm_init_posix.  */
>        ioptions = scm_to_int (options);
>      }
> +#endif
>    SCM_SYSCALL (i = waitpid (scm_to_int (pid), &status, ioptions));
>    if (i == -1)
>      SCM_SYSERROR;
> @@ -736,7 +778,6 @@ SCM_DEFINE (scm_waitpid, "waitpid", 1, 1, 0,
>  #undef FUNC_NAME
>  #endif /* HAVE_WAITPID */
>  
> -#ifndef __MINGW32__
>  SCM_DEFINE (scm_status_exit_val, "status:exit-val", 1, 0, 0, 
>              (SCM status),
>           "Return the exit status value, as would be set if a process\n"
> @@ -787,7 +828,6 @@ SCM_DEFINE (scm_status_stop_sig, "status:stop-sig", 1, 0, 
> 0,
>      return SCM_BOOL_F;
>  }
>  #undef FUNC_NAME
> -#endif /* __MINGW32__ */
>  
>  #ifdef HAVE_GETPPID
>  SCM_DEFINE (scm_getppid, "getppid", 0, 0, 0,
> @@ -802,7 +842,6 @@ SCM_DEFINE (scm_getppid, "getppid", 0, 0, 0,
>  #endif /* HAVE_GETPPID */
>  
>  
> -#ifndef __MINGW32__
>  SCM_DEFINE (scm_getuid, "getuid", 0, 0, 0,
>              (),
>           "Return an integer representing the current real user ID.")
> @@ -932,7 +971,6 @@ SCM_DEFINE (scm_setegid, "setegid", 1, 0, 0,
>      
>  }
>  #undef FUNC_NAME
> -#endif
>  
>  
>  #ifdef HAVE_GETPGRP
> @@ -1248,6 +1286,7 @@ SCM_DEFINE (scm_fork, "primitive-fork", 0, 0, 0,
>    return scm_from_int (pid);
>  }
>  #undef FUNC_NAME
> +#endif /* HAVE_FORK */
>  
>  /* Since Guile uses threads, we have to be very careful to avoid calling
>     functions that are not async-signal-safe in the child.  That's why
> @@ -1321,7 +1360,130 @@ scm_open_process (SCM mode, SCM prog, SCM args)
>    }
>  #endif
>  
> +#ifdef HAVE_FORK
>    pid = fork ();
> +#elif defined(__MINGW32__)
> +  {
> +    int save_stdin = -1, save_stdout = -1;
> +    int errno_save;
> +
> +    if (reading)
> +      {
> +     save_stdout = dup (1);
> +     errno_save = errno;
> +     if (save_stdout == -1)
> +       {
> +         close (c2p[0]);
> +         close (c2p[1]);
> +         free (exec_file);
> +         errno = errno_save;
> +         SCM_SYSERROR;
> +       }
> +      }
> +
> +    if (writing)
> +      {
> +     save_stdin = dup (0);
> +     errno_save = errno;
> +     if (save_stdin == -1)
> +       {
> +         if (reading)
> +           close (save_stdout);
> +         close (p2c[0]);
> +         close (p2c[1]);
> +         free (exec_file);
> +         errno = errno_save;
> +         SCM_SYSERROR;
> +       }
> +      }
> +
> +    if (reading)
> +      {
> +     close (1);
> +     if (dup (c2p[1]) != 1)
> +       {
> +         errno_save = errno;
> +         close (save_stdout);
> +         close (c2p[0]);
> +         close (c2p[1]);
> +         if (writing)
> +           {
> +             close (save_stdin);
> +             close (p2c[0]);
> +             close (p2c[1]);
> +           }
> +         errno = errno_save;
> +         SCM_SYSERROR;
> +       }
> +     close (c2p[1]);
> +      }
> +    if (writing)
> +      {
> +     close (0);
> +     if (dup (p2c[0]) != 0)
> +       {
> +         errno_save = errno;
> +         close (save_stdin);
> +         close (p2c[0]);
> +         close (p2c[1]);
> +         if (reading)
> +           {
> +             close (save_stdout);
> +             close (c2p[0]);
> +             close (c2p[1]);
> +           }
> +         errno = errno_save;
> +         SCM_SYSERROR;
> +       }
> +     close (p2c[0]);
> +      }
> +
> +    pid = spawnvp (P_NOWAIT, exec_file, exec_argv);
> +    errno_save = errno;
> +
> +    if (reading)
> +      {
> +     close (1);
> +     if (dup (save_stdout) != 1)
> +       {
> +         if (writing)
> +           close (save_stdin);
> +         close (save_stdout);
> +         close (p2c[1]);
> +         close (c2p[0]);
> +         errno = errno_save;
> +         SCM_SYSERROR;
> +       }
> +     close (save_stdout);
> +      }
> +    if (writing)
> +      {
> +     close (0);
> +     if (dup (save_stdin) != 0)
> +       {
> +         if (reading)
> +           close (save_stdout);
> +         close (save_stdin);
> +         close (p2c[1]);
> +         close (c2p[0]);
> +         errno = errno_save;
> +         SCM_SYSERROR;
> +       }
> +     close (save_stdin);
> +      }
> +
> +    if (pid < 0)
> +      errno = errno_save;
> +  }
> +#else
> +  close (c2p[0]);
> +  close (c2p[1]);
> +  close (p2c[0]);
> +  close (p2c[1]);
> +  free (exec_file);
> +  errno = ENOSYS;
> +  SCM_SYSERROR;
> +#endif       /* HAVE_FORK */
>  
>    if (pid == -1)
>      {
> @@ -1330,14 +1492,28 @@ scm_open_process (SCM mode, SCM prog, SCM args)
>        if (reading)
>          {
>            close (c2p[0]);
> +#ifdef HAVE_FORK
>            close (c2p[1]);
> +#endif
>          }
>        if (writing)
>          {
> +#ifdef HAVE_FORK
>            close (p2c[0]);
> +#endif
>            close (p2c[1]);
>          }
>        errno = errno_save;
> +
> +#ifndef HAVE_FORK
> +      /* The exec failed!  There is nothing sensible to do.  */
> +      if (err > 0)
> +     {
> +       char *msg = strerror (errno);
> +       fprintf (fdopen (err, "a"), "In spawnvp of %s: %s\n",
> +                exec_file, msg);
> +     }
> +#endif
>        SCM_SYSERROR;
>      }
>  
> @@ -1363,7 +1539,8 @@ scm_open_process (SCM mode, SCM prog, SCM args)
>        return scm_values
>          (scm_list_3 (read_port, write_port, scm_from_int (pid)));
>      }
> -  
> +
> +#ifdef HAVE_FORK
>    /* The child.  */
>    if (reading)
>      close (c2p[0]);
> @@ -1412,16 +1589,16 @@ scm_open_process (SCM mode, SCM prog, SCM args)
>    if (err > 0)
>      {
>        char *msg = strerror (errno);
> -      fprintf (fdopen (err, "a"), "In execlp of %s: %s\n",
> +      fprintf (fdopen (err, "a"), "In execvp of %s: %s\n",
>                 exec_file, msg);
>      }
>  
>    _exit (EXIT_FAILURE);
>    /* Not reached.  */
>    return SCM_BOOL_F;
> +#endif       /* HAVE_FORK */
>  }
>  #undef FUNC_NAME
> -#endif /* HAVE_FORK */
>  
>  #ifdef __MINGW32__
>  # include "win32-uname.h"
> @@ -2239,13 +2416,11 @@ SCM_DEFINE (scm_gethostname, "gethostname", 0, 0, 0,
>  #endif /* HAVE_GETHOSTNAME */
>  
>  
> -#ifdef HAVE_FORK
>  static void
>  scm_init_popen (void)
>  {
>    scm_c_define_gsubr ("open-process", 2, 0, 1, scm_open_process);
>  }
> -#endif
>  
>  void
>  scm_init_posix ()
> @@ -2338,11 +2513,11 @@ scm_init_posix ()
>  
>  #ifdef HAVE_FORK
>    scm_add_feature ("fork");
> +#endif       /* HAVE_FORK */
>    scm_c_register_extension ("libguile-" SCM_EFFECTIVE_VERSION,
>                              "scm_init_popen",
>                           (scm_t_extension_init_func) scm_init_popen,
>                           NULL);
> -#endif       /* HAVE_FORK */
>  }
>  
>  /*