libiberty/pexecute.c

   1 /* Utilities to execute a program in a subprocess (possibly linked by pipes
   2    with other subprocesses), and wait for it.
   3    Copyright (C) 2004-2020 Free Software Foundation, Inc.
   4
   5 This file is part of the libiberty library.
   6 Libiberty is free software; you can redistribute it and/or
   7 modify it under the terms of the GNU Library General Public
   8 License as published by the Free Software Foundation; either
   9 version 2 of the License, or (at your option) any later version.
  10
  11 Libiberty is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 Library General Public License for more details.
  15
  16 You should have received a copy of the GNU Library General Public
  17 License along with libiberty; see the file COPYING.LIB.  If not,
  18 write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
  19 Boston, MA 02110-1301, USA.  */
  20
  21 /* pexecute is an old routine.  This implementation uses the newer
  22    pex_init/pex_run/pex_get_status/pex_free routines.  Don't use
  23    pexecute in new code.  Use the newer routines instead.  */
  24
  25 #include "config.h"
  26 #include "libiberty.h"
  27
  28 #ifdef HAVE_STDLIB_H
  29 #include <stdlib.h>
  30 #endif
  31
  32 /* We only permit a single pexecute chain to execute at a time.  This
  33    was always true anyhow, though it wasn't documented.  */
  34
  35 static struct pex_obj *pex;
  36 static int idx;
  37
  38 int
  39 pexecute (const char *program, char * const *argv, const char *pname,
  40           const char *temp_base, char **errmsg_fmt, char **errmsg_arg,
  41           int flags)
  42 {
  43   const char *errmsg;
  44   int err;
  45
  46   if ((flags & PEXECUTE_FIRST) != 0)
  47     {
  48       if (pex != NULL)
  49         {
  50           *errmsg_fmt = (char *) "pexecute already in progress";
  51           *errmsg_arg = NULL;
  52           return -1;
  53         }
  54       pex = pex_init (PEX_USE_PIPES, pname, temp_base);
  55       idx = 0;
  56     }
  57   else
  58     {
  59       if (pex == NULL)
  60         {
  61           *errmsg_fmt = (char *) "pexecute not in progress";
  62           *errmsg_arg = NULL;
  63           return -1;
  64         }
  65     }
  66
  67   errmsg = pex_run (pex,
  68                     (((flags & PEXECUTE_LAST) != 0 ? PEX_LAST : 0)
  69                      | ((flags & PEXECUTE_SEARCH) != 0 ? PEX_SEARCH : 0)),
  70                     program, argv, NULL, NULL, &err);
  71   if (errmsg != NULL)
  72     {
  73       *errmsg_fmt = (char *) errmsg;
  74       *errmsg_arg = NULL;
  75       return -1;
  76     }
  77
  78   /* Instead of a PID, we just return a one-based index into the
  79      status values.  We avoid zero just because the old pexecute would
  80      never return it.  */
  81   return ++idx;
  82 }
  83
  84 int
  85 pwait (int pid, int *status, int flags ATTRIBUTE_UNUSED)
  86 {
  87   /* The PID returned by pexecute is one-based.  */
  88   --pid;
  89
  90   if (pex == NULL || pid < 0 || pid >= idx)
  91     return -1;
  92
  93   if (pid == 0 && idx == 1)
  94     {
  95       if (!pex_get_status (pex, 1, status))
  96         return -1;
  97     }
  98   else
  99     {
 100       int *vector;
 101
 102       vector = XNEWVEC (int, idx);
 103       if (!pex_get_status (pex, idx, vector))
 104         {
 105           free (vector);
 106           return -1;
 107         }
 108       *status = vector[pid];
 109       free (vector);
 110     }
 111
 112   /* Assume that we are done after the caller has retrieved the last
 113      exit status.  The original implementation did not require that
 114      the exit statuses be retrieved in order, but this implementation
 115      does.  */
 116   if (pid + 1 == idx)
 117     {
 118       pex_free (pex);
 119       pex = NULL;
 120       idx = 0;
 121     }
 122
 123   return pid + 1;
 124 }