1 # posix_spawn.m4 serial 2
2 dnl Copyright (C) 2008 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 dnl Tests whether the entire posix_spawn facility is available.
8 AC_DEFUN([gl_POSIX_SPAWN],
10 AC_REQUIRE([gl_POSIX_SPAWN_BODY])
13 AC_DEFUN([gl_POSIX_SPAWN_BODY],
15 AC_REQUIRE([gl_SPAWN_H_DEFAULTS])
16 AC_CHECK_FUNCS_ONCE([posix_spawn])
17 dnl Assume that when the main function exists, all the others are
18 dnl available as well.
19 dnl AC_CHECK_FUNCS_ONCE([posix_spawnp])
20 dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_init])
21 dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_addclose])
22 dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_adddup2])
23 dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_addopen])
24 dnl AC_CHECK_FUNCS_ONCE([posix_spawn_file_actions_destroy])
25 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_init])
26 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getflags])
27 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setflags])
28 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getpgroup])
29 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setpgroup])
30 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getschedparam])
31 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setschedparam])
32 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getschedpolicy])
33 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setschedpolicy])
34 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getsigdefault])
35 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setsigdefault])
36 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_getsigmask])
37 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_setsigmask])
38 dnl AC_CHECK_FUNCS_ONCE([posix_spawnattr_destroy])
39 if test $ac_cv_func_posix_spawn = yes; then
41 case "$gl_cv_func_posix_spawn_works" in
43 *) REPLACE_POSIX_SPAWN=1 ;;
50 dnl Test whether posix_spawn actually works.
51 dnl posix_spawn on AIX 5.3..6.1 has a bug: When it fails to execute the
52 dnl program, the child process exits with exit() rather than _exit(),
53 dnl which causes the stdio buffers to be flushed. Reported by Rainer Tammer.
54 dnl posix_spawn on AIX 5.3..6.1 has also a second bug: It does not work
55 dnl when POSIX threads are used. But we don't test against this bug here.
56 AC_DEFUN([gl_POSIX_SPAWN_WORKS],
58 AC_REQUIRE([AC_PROG_CC])
59 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
60 AC_CACHE_CHECK([whether posix_spawn works], [gl_cv_func_posix_spawn_works],
61 [if test $cross_compiling = no; then
62 AC_LINK_IFELSE([AC_LANG_PROGRAM([[
72 #include <sys/types.h>
75 extern char **environ;
78 # define STDIN_FILENO 0
81 # define STDOUT_FILENO 1
84 # define STDERR_FILENO 2
88 # define WTERMSIG(x) ((x) & 0x7f)
91 # define WCOREDUMP(x) ((x) & 0x80)
94 # define WEXITSTATUS(x) (((x) >> 8) & 0xff)
97 # define WIFSIGNALED(x) (WTERMSIG (x) != 0 && WTERMSIG(x) != 0x7f)
100 # define WIFEXITED(x) (WTERMSIG (x) == 0)
103 # define WIFSTOPPED(x) (WTERMSIG (x) == 0x7f)
106 #define CHILD_PROGRAM_FILENAME "/non/exist/ent"
111 if (0 <= fd && fd <= 2)
113 int f = fd_safer (dup (fd));
123 dnl Now comes the main() function.
125 char *argv[2] = { CHILD_PROGRAM_FILENAME, NULL };
127 sigset_t blocked_signals;
128 sigset_t fatal_signal_set;
129 posix_spawn_file_actions_t actions;
130 bool actions_allocated;
131 posix_spawnattr_t attrs;
132 bool attrs_allocated;
138 setvbuf (stdout, NULL, _IOFBF, 0);
139 puts ("This should be seen only once.");
140 if (pipe (ofd) < 0 || (ofd[1] = fd_safer (ofd[1])) < 0)
142 perror ("cannot create pipe");
145 sigprocmask (SIG_SETMASK, NULL, &blocked_signals);
146 sigemptyset (&fatal_signal_set);
147 sigaddset (&fatal_signal_set, SIGINT);
148 sigaddset (&fatal_signal_set, SIGTERM);
149 sigaddset (&fatal_signal_set, SIGHUP);
150 sigaddset (&fatal_signal_set, SIGPIPE);
151 sigprocmask (SIG_BLOCK, &fatal_signal_set, NULL);
152 actions_allocated = false;
153 attrs_allocated = false;
154 if ((err = posix_spawn_file_actions_init (&actions)) != 0
155 || (actions_allocated = true,
156 (err = posix_spawn_file_actions_adddup2 (&actions, ofd[0], STDIN_FILENO)) != 0
157 || (err = posix_spawn_file_actions_addclose (&actions, ofd[0])) != 0
158 || (err = posix_spawn_file_actions_addclose (&actions, ofd[1])) != 0
159 || (err = posix_spawnattr_init (&attrs)) != 0
160 || (attrs_allocated = true,
161 (err = posix_spawnattr_setsigmask (&attrs, &blocked_signals)) != 0
162 || (err = posix_spawnattr_setflags (&attrs, POSIX_SPAWN_SETSIGMASK)) != 0)
163 || (err = posix_spawnp (&child, CHILD_PROGRAM_FILENAME, &actions, &attrs, argv, environ)) != 0))
165 if (actions_allocated)
166 posix_spawn_file_actions_destroy (&actions);
168 posix_spawnattr_destroy (&attrs);
169 sigprocmask (SIG_UNBLOCK, &fatal_signal_set, NULL);
171 perror ("subprocess failed");
174 posix_spawn_file_actions_destroy (&actions);
175 posix_spawnattr_destroy (&attrs);
176 sigprocmask (SIG_UNBLOCK, &fatal_signal_set, NULL);
180 while (waitpid (child, &status, 0) != child)
182 if (!WIFEXITED (status))
184 fprintf (stderr, "subprocess terminated with unexpected wait status %d\n", status);
187 exitstatus = WEXITSTATUS (status);
188 if (exitstatus != 127)
190 fprintf (stderr, "subprocess terminated with unexpected exit status %d\n", exitstatus);
194 [if test -s conftest$ac_exeext \
195 && ./conftest$ac_exeext > conftest.out \
196 && echo 'This should be seen only once.' > conftest.ok \
197 && cmp conftest.out conftest.ok > /dev/null; then
198 gl_cv_func_posix_spawn_works=yes
200 gl_cv_func_posix_spawn_works=no
202 [gl_cv_func_posix_spawn_works=no])
205 aix*) gl_cv_func_posix_spawn_works="guessing no";;
206 *) gl_cv_func_posix_spawn_works="guessing yes";;
212 AC_DEFUN([gl_POSIX_SPAWN_INTERNAL],
215 dnl Prerequisites of lib/spawni.c.
216 AC_CHECK_HEADERS([paths.h])
217 AC_CHECK_FUNCS([confstr sched_setparam sched_setscheduler setegid seteuid vfork])