libiberty/pex-djgpp.c

   1 /* Utilities to execute a program in a subprocess (possibly linked by pipes
   2    with other subprocesses), and wait for it.  DJGPP specialization.
   3    Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2003
   4    Free Software Foundation, Inc.
   5
   6 This file is part of the libiberty library.
   7 Libiberty is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU Library General Public
   9 License as published by the Free Software Foundation; either
  10 version 2 of the License, or (at your option) any later version.
  11
  12 Libiberty is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 Library General Public License for more details.
  16
  17 You should have received a copy of the GNU Library General Public
  18 License along with libiberty; see the file COPYING.LIB.  If not,
  19 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #include "pex-common.h"
  23
  24 #include <stdio.h>
  25 #include <errno.h>
  26 #ifdef NEED_DECLARATION_ERRNO
  27 extern int errno;
  28 #endif
  29 #ifdef HAVE_STDLIB_H
  30 #include <stdlib.h>
  31 #endif
  32 #include <process.h>
  33
  34 /* Use ECHILD if available, otherwise use EINVAL.  */
  35 #ifdef ECHILD
  36 #define PWAIT_ERROR ECHILD
  37 #else
  38 #define PWAIT_ERROR EINVAL
  39 #endif
  40
  41 /* MSDOS doesn't multitask, but for the sake of a consistent interface
  42    the code behaves like it does.  pexecute runs the program, tucks the
  43    exit code away, and returns a "pid".  pwait must be called to fetch the
  44    exit code.  */
  45
  46 /* For communicating information from pexecute to pwait.  */
  47 static int last_pid = 0;
  48 static int last_status = 0;
  49 static int last_reaped = 0;
  50
  51 int
  52 pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
  53      const char *program;
  54      char * const *argv;
  55      const char *this_pname;
  56      const char *temp_base;
  57      char **errmsg_fmt, **errmsg_arg;
  58      int flags;
  59 {
  60   int rc;
  61
  62   last_pid++;
  63   if (last_pid < 0)
  64     last_pid = 1;
  65
  66   if ((flags & PEXECUTE_ONE) != PEXECUTE_ONE)
  67     abort ();
  68
  69   /* ??? What are the possible return values from spawnv?  */
  70   rc = (flags & PEXECUTE_SEARCH ? spawnvp : spawnv) (P_WAIT, program, argv);
  71
  72   if (rc == -1)
  73     {
  74       *errmsg_fmt = install_error_msg;
  75       *errmsg_arg = (char *)program;
  76       return -1;
  77     }
  78
  79   /* Tuck the status away for pwait, and return a "pid".  */
  80   last_status = rc << 8;
  81   return last_pid;
  82 }
  83
  84 int
  85 pwait (pid, status, flags)
  86      int pid;
  87      int *status;
  88      int flags;
  89 {
  90   /* On MSDOS each pexecute must be followed by its associated pwait.  */
  91   if (pid != last_pid
  92       /* Called twice for the same child?  */
  93       || pid == last_reaped)
  94     {
  95       errno = PWAIT_ERROR;
  96       return -1;
  97     }
  98   /* ??? Here's an opportunity to canonicalize the values in STATUS.
  99      Needed?  */
 100   *status = (last_status >> 8);
 101   last_reaped = last_pid;
 102   return last_pid;
 103 }