summaryrefslogtreecommitdiff
path: root/m4/posix_spawn.m4
blob: 97cb64b96a6648fa50c16f6fc300cb6b54e46289 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
# posix_spawn.m4 serial 11
dnl Copyright (C) 2008-2014 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

dnl Tests whether the entire posix_spawn facility is available.
AC_DEFUN([gl_POSIX_SPAWN],
[
  AC_REQUIRE([gl_POSIX_SPAWN_BODY])
])

AC_DEFUN([gl_POSIX_SPAWN_BODY],
[
  AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
  AC_REQUIRE([gl_HAVE_POSIX_SPAWN])
  dnl Assume that when the main function exists, all the others,
  dnl except posix_spawnattr_{get,set}sched*, are available as well.
  dnl AC_CHECK_FUNCS_ONCE([posix_spawnp])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_init])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_addclose])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_adddup2])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_addopen])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_destroy])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_init])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getflags])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setflags])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getpgroup])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setpgroup])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getsigdefault])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setsigdefault])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getsigmask])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setsigmask])
  dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_destroy])
  if test $ac_cv_func_posix_spawn = yes; then
    gl_POSIX_SPAWN_WORKS
    case "$gl_cv_func_posix_spawn_works" in
      *yes)
        AC_DEFINE([HAVE_WORKING_POSIX_SPAWN], [1],
          [Define if you have the posix_spawn and posix_spawnp functions and
           they work.])
        dnl Assume that these functions are available if POSIX_SPAWN_SETSCHEDULER
        dnl evaluates to nonzero.
        dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getschedpolicy])
        dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setschedpolicy])
        AC_CACHE_CHECK([whether posix_spawnattr_setschedpolicy is supported],
          [gl_cv_func_spawnattr_setschedpolicy],
          [AC_EGREP_CPP([POSIX scheduling supported], [
#include <spawn.h>
#if POSIX_SPAWN_SETSCHEDULER
 POSIX scheduling supported
#endif
],
             [gl_cv_func_spawnattr_setschedpolicy=yes],
             [gl_cv_func_spawnattr_setschedpolicy=no])
          ])
        dnl Assume that these functions are available if POSIX_SPAWN_SETSCHEDPARAM
        dnl evaluates to nonzero.
        dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getschedparam])
        dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setschedparam])
        AC_CACHE_CHECK([whether posix_spawnattr_setschedparam is supported],
          [gl_cv_func_spawnattr_setschedparam],
          [AC_EGREP_CPP([POSIX scheduling supported], [
#include <spawn.h>
#if POSIX_SPAWN_SETSCHEDPARAM
 POSIX scheduling supported
#endif
],
             [gl_cv_func_spawnattr_setschedparam=yes],
             [gl_cv_func_spawnattr_setschedparam=no])
          ])
        ;;
      *) REPLACE_POSIX_SPAWN=1 ;;
    esac
  fi
])

dnl Test whether posix_spawn actually works.
dnl posix_spawn on AIX 5.3..6.1 has two bugs:
dnl 1) When it fails to execute the program, the child process exits with
dnl    exit() rather than _exit(), which causes the stdio buffers to be
dnl    flushed. Reported by Rainer Tammer.
dnl 2) The posix_spawn_file_actions_addopen function does not support file
dnl    names that contain a '*'.
dnl posix_spawn on AIX 5.3..6.1 has also a third bug: It does not work
dnl when POSIX threads are used. But we don't test against this bug here.
AC_DEFUN([gl_POSIX_SPAWN_WORKS],
[
  AC_REQUIRE([AC_PROG_CC])
  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
  AC_CACHE_CHECK([whether posix_spawn works], [gl_cv_func_posix_spawn_works],
    [if test $cross_compiling = no; then
       AC_LINK_IFELSE([AC_LANG_SOURCE([[
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <spawn.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>

extern char **environ;

#ifndef STDIN_FILENO
# define STDIN_FILENO 0
#endif
#ifndef STDOUT_FILENO
# define STDOUT_FILENO 1
#endif
#ifndef STDERR_FILENO
# define STDERR_FILENO 2
#endif

#ifndef WTERMSIG
# define WTERMSIG(x) ((x) & 0x7f)
#endif
#ifndef WIFEXITED
# define WIFEXITED(x) (WTERMSIG (x) == 0)
#endif
#ifndef WEXITSTATUS
# define WEXITSTATUS(x) (((x) >> 8) & 0xff)
#endif

#define CHILD_PROGRAM_FILENAME "/non/exist/ent"

static int
fd_safer (int fd)
{
  if (0 <= fd && fd <= 2)
    {
      int f = fd_safer (dup (fd));
      int e = errno;
      close (fd);
      errno = e;
      fd = f;
    }

  return fd;
}

int
main ()
{
  char *argv[2] = { CHILD_PROGRAM_FILENAME, NULL };
  int ofd[2];
  sigset_t blocked_signals;
  sigset_t fatal_signal_set;
  posix_spawn_file_actions_t actions;
  bool actions_allocated;
  posix_spawnattr_t attrs;
  bool attrs_allocated;
  int err;
  pid_t child;
  int status;
  int exitstatus;

  setvbuf (stdout, NULL, _IOFBF, 0);
  puts ("This should be seen only once.");
  if (pipe (ofd) < 0 || (ofd[1] = fd_safer (ofd[1])) < 0)
    {
      perror ("cannot create pipe");
      exit (1);
    }
  sigprocmask (SIG_SETMASK, NULL, &blocked_signals);
  sigemptyset (&fatal_signal_set);
  sigaddset (&fatal_signal_set, SIGINT);
  sigaddset (&fatal_signal_set, SIGTERM);
  sigaddset (&fatal_signal_set, SIGHUP);
  sigaddset (&fatal_signal_set, SIGPIPE);
  sigprocmask (SIG_BLOCK, &fatal_signal_set, NULL);
  actions_allocated = false;
  attrs_allocated = false;
  if ((err = posix_spawn_file_actions_init (&actions)) != 0
      || (actions_allocated = true,
          (err = posix_spawn_file_actions_adddup2 (&actions, ofd[0], STDIN_FILENO)) != 0
          || (err = posix_spawn_file_actions_addclose (&actions, ofd[0])) != 0
          || (err = posix_spawn_file_actions_addclose (&actions, ofd[1])) != 0
          || (err = posix_spawnattr_init (&attrs)) != 0
          || (attrs_allocated = true,
              (err = posix_spawnattr_setsigmask (&attrs, &blocked_signals)) != 0
              || (err = posix_spawnattr_setflags (&attrs, POSIX_SPAWN_SETSIGMASK)) != 0)
          || (err = posix_spawnp (&child, CHILD_PROGRAM_FILENAME, &actions, &attrs, argv, environ)) != 0))
    {
      if (actions_allocated)
        posix_spawn_file_actions_destroy (&actions);
      if (attrs_allocated)
        posix_spawnattr_destroy (&attrs);
      sigprocmask (SIG_UNBLOCK, &fatal_signal_set, NULL);
      if (err == ENOENT)
        return 0;
      else
        {
          errno = err;
          perror ("subprocess failed");
          exit (1);
        }
    }
  posix_spawn_file_actions_destroy (&actions);
  posix_spawnattr_destroy (&attrs);
  sigprocmask (SIG_UNBLOCK, &fatal_signal_set, NULL);
  close (ofd[0]);
  close (ofd[1]);
  status = 0;
  while (waitpid (child, &status, 0) != child)
    ;
  if (!WIFEXITED (status))
    {
      fprintf (stderr, "subprocess terminated with unexpected wait status %d\n", status);
      exit (1);
    }
  exitstatus = WEXITSTATUS (status);
  if (exitstatus != 127)
    {
      fprintf (stderr, "subprocess terminated with unexpected exit status %d\n", exitstatus);
      exit (1);
    }
  return 0;
}
]])],
         [if test -s conftest$ac_exeext \
             && ./conftest$ac_exeext > conftest.out \
             && echo 'This should be seen only once.' > conftest.ok \
             && cmp conftest.out conftest.ok > /dev/null; then
            gl_cv_func_posix_spawn_works=yes
          else
            gl_cv_func_posix_spawn_works=no
          fi],
         [gl_cv_func_posix_spawn_works=no])
       if test $gl_cv_func_posix_spawn_works = yes; then
         AC_RUN_IFELSE([AC_LANG_SOURCE([[
/* Test whether posix_spawn_file_actions_addopen supports filename arguments
   that contain special characters such as '*'.  */

#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <spawn.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>

extern char **environ;

#ifndef STDIN_FILENO
# define STDIN_FILENO 0
#endif
#ifndef STDOUT_FILENO
# define STDOUT_FILENO 1
#endif
#ifndef STDERR_FILENO
# define STDERR_FILENO 2
#endif

#ifndef WTERMSIG
# define WTERMSIG(x) ((x) & 0x7f)
#endif
#ifndef WIFEXITED
# define WIFEXITED(x) (WTERMSIG (x) == 0)
#endif
#ifndef WEXITSTATUS
# define WEXITSTATUS(x) (((x) >> 8) & 0xff)
#endif

#define CHILD_PROGRAM_FILENAME "conftest"
#define DATA_FILENAME "conftest%=*#?"

static int
parent_main (void)
{
  FILE *fp;
  char *argv[3] = { CHILD_PROGRAM_FILENAME, "-child", NULL };
  posix_spawn_file_actions_t actions;
  bool actions_allocated;
  int err;
  pid_t child;
  int status;
  int exitstatus;

  /* Create a data file with specific contents.  */
  fp = fopen (DATA_FILENAME, "wb");
  if (fp == NULL)
    {
      perror ("cannot create data file");
      return 1;
    }
  fwrite ("Halle Potta", 1, 11, fp);
  if (fflush (fp) || fclose (fp))
    {
      perror ("cannot prepare data file");
      return 2;
    }

  /* Avoid reading from our stdin, as it could block.  */
  freopen ("/dev/null", "rb", stdin);

  /* Test whether posix_spawn_file_actions_addopen with this file name
     actually works, but spawning a child that reads from this file.  */
  actions_allocated = false;
  if ((err = posix_spawn_file_actions_init (&actions)) != 0
      || (actions_allocated = true,
          (err = posix_spawn_file_actions_addopen (&actions, STDIN_FILENO, DATA_FILENAME, O_RDONLY, 0600)) != 0
          || (err = posix_spawn (&child, CHILD_PROGRAM_FILENAME, &actions, NULL, argv, environ)) != 0))
    {
      if (actions_allocated)
        posix_spawn_file_actions_destroy (&actions);
      errno = err;
      perror ("subprocess failed");
      return 3;
    }
  posix_spawn_file_actions_destroy (&actions);
  status = 0;
  while (waitpid (child, &status, 0) != child)
    ;
  if (!WIFEXITED (status))
    {
      fprintf (stderr, "subprocess terminated with unexpected wait status %d\n", status);
      return 4;
    }
  exitstatus = WEXITSTATUS (status);
  if (exitstatus != 0)
    {
      fprintf (stderr, "subprocess terminated with unexpected exit status %d\n", exitstatus);
      return 5;
    }
  return 0;
}

static int
child_main (void)
{
  char buf[1024];

  /* See if reading from STDIN_FILENO yields the expected contents.  */
  if (fread (buf, 1, sizeof (buf), stdin) == 11
      && memcmp (buf, "Halle Potta", 11) == 0)
    return 0;
  else
    return 8;
}

static void
cleanup_then_die (int sig)
{
  /* Clean up data file.  */
  unlink (DATA_FILENAME);

  /* Re-raise the signal and die from it.  */
  signal (sig, SIG_DFL);
  raise (sig);
}

int
main (int argc, char *argv[])
{
  int exitstatus;

  if (!(argc > 1 && strcmp (argv[1], "-child") == 0))
    {
      /* This is the parent process.  */
      signal (SIGINT, cleanup_then_die);
      signal (SIGTERM, cleanup_then_die);
      #ifdef SIGHUP
      signal (SIGHUP, cleanup_then_die);
      #endif

      exitstatus = parent_main ();
    }
  else
    {
      /* This is the child process.  */

      exitstatus = child_main ();
    }
  unlink (DATA_FILENAME);
  return exitstatus;
}
]])],
           [],
           [gl_cv_func_posix_spawn_works=no])
       fi
     else
       case "$host_os" in
         aix*) gl_cv_func_posix_spawn_works="guessing no";;
         *)    gl_cv_func_posix_spawn_works="guessing yes";;
       esac
     fi
    ])
])

# Prerequisites of lib/spawni.c.
AC_DEFUN([gl_PREREQ_POSIX_SPAWN_INTERNAL],
[
  AC_CHECK_HEADERS([paths.h])
  AC_CHECK_FUNCS([confstr sched_setparam sched_setscheduler setegid seteuid vfork])
])

AC_DEFUN([gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE],
[
  AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
  AC_REQUIRE([AC_PROG_CC])
  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
  gl_POSIX_SPAWN
  if test $REPLACE_POSIX_SPAWN = 1; then
    REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE=1
  else
    dnl On Solaris 11 2011-11, posix_spawn_file_actions_addclose succeeds even
    dnl if the fd argument is out of range.
    AC_CACHE_CHECK([whether posix_spawn_file_actions_addclose works],
      [gl_cv_func_posix_spawn_file_actions_addclose_works],
      [AC_RUN_IFELSE(
         [AC_LANG_SOURCE([[
#include <spawn.h>
int main ()
{
  posix_spawn_file_actions_t actions;
  if (posix_spawn_file_actions_init (&actions) != 0)
    return 1;
  if (posix_spawn_file_actions_addclose (&actions, 10000000) == 0)
    return 2;
  return 0;
}]])],
         [gl_cv_func_posix_spawn_file_actions_addclose_works=yes],
         [gl_cv_func_posix_spawn_file_actions_addclose_works=no],
         [# Guess no on Solaris, yes otherwise.
          case "$host_os" in
            solaris*) gl_cv_func_posix_spawn_file_actions_addclose_works="guessing no";;
            *)        gl_cv_func_posix_spawn_file_actions_addclose_works="guessing yes";;
          esac
         ])
      ])
    case "$gl_cv_func_posix_spawn_file_actions_addclose_works" in
      *yes) ;;
      *) REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE=1 ;;
    esac
  fi
])

AC_DEFUN([gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2],
[
  AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
  AC_REQUIRE([AC_PROG_CC])
  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
  gl_POSIX_SPAWN
  if test $REPLACE_POSIX_SPAWN = 1; then
    REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2=1
  else
    dnl On Solaris 11 2011-11, posix_spawn_file_actions_adddup2 succeeds even
    dnl if the fd argument is out of range.
    AC_CACHE_CHECK([whether posix_spawn_file_actions_adddup2 works],
      [gl_cv_func_posix_spawn_file_actions_adddup2_works],
      [AC_RUN_IFELSE(
         [AC_LANG_SOURCE([[
#include <spawn.h>
int main ()
{
  posix_spawn_file_actions_t actions;
  if (posix_spawn_file_actions_init (&actions) != 0)
    return 1;
  if (posix_spawn_file_actions_adddup2 (&actions, 10000000, 2) == 0)
    return 2;
  return 0;
}]])],
         [gl_cv_func_posix_spawn_file_actions_adddup2_works=yes],
         [gl_cv_func_posix_spawn_file_actions_adddup2_works=no],
         [# Guess no on Solaris, yes otherwise.
          case "$host_os" in
            solaris*) gl_cv_func_posix_spawn_file_actions_adddup2_works="guessing no";;
            *)        gl_cv_func_posix_spawn_file_actions_adddup2_works="guessing yes";;
          esac
         ])
      ])
    case "$gl_cv_func_posix_spawn_file_actions_adddup2_works" in
      *yes) ;;
      *) REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2=1 ;;
    esac
  fi
])

AC_DEFUN([gl_FUNC_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN],
[
  AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
  AC_REQUIRE([AC_PROG_CC])
  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
  gl_POSIX_SPAWN
  if test $REPLACE_POSIX_SPAWN = 1; then
    REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN=1
  else
    dnl On Solaris 11 2011-11, posix_spawn_file_actions_addopen succeeds even
    dnl if the fd argument is out of range.
    AC_CACHE_CHECK([whether posix_spawn_file_actions_addopen works],
      [gl_cv_func_posix_spawn_file_actions_addopen_works],
      [AC_RUN_IFELSE(
         [AC_LANG_SOURCE([[
#include <spawn.h>
#include <fcntl.h>
int main ()
{
  posix_spawn_file_actions_t actions;
  if (posix_spawn_file_actions_init (&actions) != 0)
    return 1;
  if (posix_spawn_file_actions_addopen (&actions, 10000000, "foo", 0, O_RDONLY)
      == 0)
    return 2;
  return 0;
}]])],
         [gl_cv_func_posix_spawn_file_actions_addopen_works=yes],
         [gl_cv_func_posix_spawn_file_actions_addopen_works=no],
         [# Guess no on Solaris, yes otherwise.
          case "$host_os" in
            solaris*) gl_cv_func_posix_spawn_file_actions_addopen_works="guessing no";;
            *)        gl_cv_func_posix_spawn_file_actions_addopen_works="guessing yes";;
          esac
         ])
      ])
    case "$gl_cv_func_posix_spawn_file_actions_addopen_works" in
      *yes) ;;
      *) REPLACE_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN=1 ;;
    esac
  fi
])