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) 1996-2020 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 #include "pex-common.h"
  22
  23 #include <stdio.h>
  24 #include <errno.h>
  25 #ifdef NEED_DECLARATION_ERRNO
  26 extern int errno;
  27 #endif
  28 #ifdef HAVE_STDLIB_H
  29 #include <stdlib.h>
  30 #endif
  31 #include <string.h>
  32 #include <fcntl.h>
  33 #include <unistd.h>
  34 #include <sys/stat.h>
  35 #include <process.h>
  36
  37 /* Use ECHILD if available, otherwise use EINVAL.  */
  38 #ifdef ECHILD
  39 #define PWAIT_ERROR ECHILD
  40 #else
  41 #define PWAIT_ERROR EINVAL
  42 #endif
  43
  44 static int pex_djgpp_open_read (struct pex_obj *, const char *, int);
  45 static int pex_djgpp_open_write (struct pex_obj *, const char *, int, int);
  46 static pid_t pex_djgpp_exec_child (struct pex_obj *, int, const char *,
  47                                   char * const *, char * const *,
  48                                   int, int, int, int,
  49                                   const char **, int *);
  50 static int pex_djgpp_close (struct pex_obj *, int);
  51 static pid_t pex_djgpp_wait (struct pex_obj *, pid_t, int *, struct pex_time *,
  52                            int, const char **, int *);
  53
  54 /* The list of functions we pass to the common routines.  */
  55
  56 const struct pex_funcs funcs =
  57 {
  58   pex_djgpp_open_read,
  59   pex_djgpp_open_write,
  60   pex_djgpp_exec_child,
  61   pex_djgpp_close,
  62   pex_djgpp_wait,
  63   NULL, /* pipe */
  64   NULL, /* fdopenr */
  65   NULL, /* fdopenw */
  66   NULL  /* cleanup */
  67 };
  68
  69 /* Return a newly initialized pex_obj structure.  */
  70
  71 struct pex_obj *
  72 pex_init (int flags, const char *pname, const char *tempbase)
  73 {
  74   /* DJGPP does not support pipes.  */
  75   flags &= ~ PEX_USE_PIPES;
  76   return pex_init_common (flags, pname, tempbase, &funcs);
  77 }
  78
  79 /* Open a file for reading.  */
  80
  81 static int
  82 pex_djgpp_open_read (struct pex_obj *obj ATTRIBUTE_UNUSED,
  83                      const char *name, int binary)
  84 {
  85   return open (name, O_RDONLY | (binary ? O_BINARY : O_TEXT));
  86 }
  87
  88 /* Open a file for writing.  */
  89
  90 static int
  91 pex_djgpp_open_write (struct pex_obj *obj ATTRIBUTE_UNUSED,
  92                       const char *name, int binary, int append)
  93 {
  94   /* Note that we can't use O_EXCL here because gcc may have already
  95      created the temporary file via make_temp_file.  */
  96   if (append)
  97     return -1;
  98   return open (name,
  99                (O_WRONLY | O_CREAT | O_TRUNC
 100                 | (binary ? O_BINARY : O_TEXT)),
 101                S_IRUSR | S_IWUSR);
 102 }
 103
 104 /* Close a file.  */
 105
 106 static int
 107 pex_djgpp_close (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd)
 108 {
 109   return close (fd);
 110 }
 111
 112 /* Execute a child.  */
 113
 114 static pid_t
 115 pex_djgpp_exec_child (struct pex_obj *obj, int flags, const char *executable,
 116                       char * const * argv, char * const * env,
 117                       int in, int out, int errdes,
 118                       int toclose ATTRIBUTE_UNUSED, const char **errmsg,
 119                       int *err)
 120 {
 121   int org_in, org_out, org_errdes;
 122   int status;
 123   int *statuses;
 124
 125   org_in = -1;
 126   org_out = -1;
 127   org_errdes = -1;
 128
 129   if (in != STDIN_FILE_NO)
 130     {
 131       org_in = dup (STDIN_FILE_NO);
 132       if (org_in < 0)
 133         {
 134           *err = errno;
 135           *errmsg = "dup";
 136           return (pid_t) -1;
 137         }
 138       if (dup2 (in, STDIN_FILE_NO) < 0)
 139         {
 140           *err = errno;
 141           *errmsg = "dup2";
 142           return (pid_t) -1;
 143         }
 144       if (close (in) < 0)
 145         {
 146           *err = errno;
 147           *errmsg = "close";
 148           return (pid_t) -1;
 149         }
 150     }
 151
 152   if (out != STDOUT_FILE_NO)
 153     {
 154       org_out = dup (STDOUT_FILE_NO);
 155       if (org_out < 0)
 156         {
 157           *err = errno;
 158           *errmsg = "dup";
 159           return (pid_t) -1;
 160         }
 161       if (dup2 (out, STDOUT_FILE_NO) < 0)
 162         {
 163           *err = errno;
 164           *errmsg = "dup2";
 165           return (pid_t) -1;
 166         }
 167       if (close (out) < 0)
 168         {
 169           *err = errno;
 170           *errmsg = "close";
 171           return (pid_t) -1;
 172         }
 173     }
 174
 175   if (errdes != STDERR_FILE_NO
 176       || (flags & PEX_STDERR_TO_STDOUT) != 0)
 177     {
 178       org_errdes = dup (STDERR_FILE_NO);
 179       if (org_errdes < 0)
 180         {
 181           *err = errno;
 182           *errmsg = "dup";
 183           return (pid_t) -1;
 184         }
 185       if (dup2 ((flags & PEX_STDERR_TO_STDOUT) != 0 ? STDOUT_FILE_NO : errdes,
 186                  STDERR_FILE_NO) < 0)
 187         {
 188           *err = errno;
 189           *errmsg = "dup2";
 190           return (pid_t) -1;
 191         }
 192       if (errdes != STDERR_FILE_NO)
 193         {
 194           if (close (errdes) < 0)
 195             {
 196               *err = errno;
 197               *errmsg = "close";
 198               return (pid_t) -1;
 199             }
 200         }
 201     }
 202
 203   if (env)
 204     status = (((flags & PEX_SEARCH) != 0 ? spawnvpe : spawnve)
 205               (P_WAIT, executable, argv, env));
 206   else
 207     status = (((flags & PEX_SEARCH) != 0 ? spawnvp : spawnv)
 208               (P_WAIT, executable, argv));
 209
 210   if (status == -1)
 211     {
 212       *err = errno;
 213       *errmsg = ((flags & PEX_SEARCH) != 0) ? "spawnvp" : "spawnv";
 214     }
 215
 216   if (in != STDIN_FILE_NO)
 217     {
 218       if (dup2 (org_in, STDIN_FILE_NO) < 0)
 219         {
 220           *err = errno;
 221           *errmsg = "dup2";
 222           return (pid_t) -1;
 223         }
 224       if (close (org_in) < 0)
 225         {
 226           *err = errno;
 227           *errmsg = "close";
 228           return (pid_t) -1;
 229         }
 230     }
 231
 232   if (out != STDOUT_FILE_NO)
 233     {
 234       if (dup2 (org_out, STDOUT_FILE_NO) < 0)
 235         {
 236           *err = errno;
 237           *errmsg = "dup2";
 238           return (pid_t) -1;
 239         }
 240       if (close (org_out) < 0)
 241         {
 242           *err = errno;
 243           *errmsg = "close";
 244           return (pid_t) -1;
 245         }
 246     }
 247
 248   if (errdes != STDERR_FILE_NO
 249       || (flags & PEX_STDERR_TO_STDOUT) != 0)
 250     {
 251       if (dup2 (org_errdes, STDERR_FILE_NO) < 0)
 252         {
 253           *err = errno;
 254           *errmsg = "dup2";
 255           return (pid_t) -1;
 256         }
 257       if (close (org_errdes) < 0)
 258         {
 259           *err = errno;
 260           *errmsg = "close";
 261           return (pid_t) -1;
 262         }
 263     }
 264
 265   /* Save the exit status for later.  When we are called, obj->count
 266      is the number of children which have executed before this
 267      one.  */
 268   statuses = (int *) obj->sysdep;
 269   statuses = XRESIZEVEC (int, statuses, obj->count + 1);
 270   statuses[obj->count] = status;
 271   obj->sysdep = (void *) statuses;
 272
 273   return (pid_t) obj->count;
 274 }
 275
 276 /* Wait for a child process to complete.  Actually the child process
 277    has already completed, and we just need to return the exit
 278    status.  */
 279
 280 static pid_t
 281 pex_djgpp_wait (struct pex_obj *obj, pid_t pid, int *status,
 282                 struct pex_time *time, int done ATTRIBUTE_UNUSED,
 283                 const char **errmsg ATTRIBUTE_UNUSED,
 284                 int *err ATTRIBUTE_UNUSED)
 285 {
 286   int *statuses;
 287
 288   if (time != NULL)
 289     memset (time, 0, sizeof *time);
 290
 291   statuses = (int *) obj->sysdep;
 292   *status = statuses[pid];
 293
 294   return 0;
 295 }