summaryrefslogtreecommitdiffstats
path: root/gl/m4/fcntl.m4
diff options
context:
space:
mode:
authorRincewindsHat <12514511+RincewindsHat@users.noreply.github.com>2023-01-31 13:46:01 (GMT)
committerRincewindsHat <12514511+RincewindsHat@users.noreply.github.com>2023-01-31 13:46:01 (GMT)
commite8bd88d1fcded01ccd066572eeaae1b507989cb3 (patch)
treec8e7be6c07c6f635f6e803e6a6ba9e7a95fee7c0 /gl/m4/fcntl.m4
parent2ad962c13473607ca0d974bfaa516a0ed53ec73d (diff)
downloadmonitoring-plugins-e8bd88d1fcded01ccd066572eeaae1b507989cb3.tar.gz
Sync with the latest Gnulib code 668c0b8ffa
Diffstat (limited to 'gl/m4/fcntl.m4')
-rw-r--r--gl/m4/fcntl.m4151
1 files changed, 151 insertions, 0 deletions
diff --git a/gl/m4/fcntl.m4 b/gl/m4/fcntl.m4
new file mode 100644
index 0000000..524a99a
--- /dev/null
+++ b/gl/m4/fcntl.m4
@@ -0,0 +1,151 @@
1# fcntl.m4 serial 11
2dnl Copyright (C) 2009-2023 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7# For now, this module ensures that fcntl()
8# - supports F_DUPFD correctly
9# - supports or emulates F_DUPFD_CLOEXEC
10# - supports F_GETFD
11# Still to be ported to mingw:
12# - F_SETFD
13# - F_GETFL, F_SETFL
14# - F_GETOWN, F_SETOWN
15# - F_GETLK, F_SETLK, F_SETLKW
16AC_DEFUN([gl_FUNC_FCNTL],
17[
18 dnl Persuade glibc to expose F_DUPFD_CLOEXEC.
19 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
20 AC_REQUIRE([gl_FCNTL_H_DEFAULTS])
21 AC_REQUIRE([AC_CANONICAL_HOST])
22 AC_CHECK_FUNCS_ONCE([fcntl])
23 if test $ac_cv_func_fcntl = no; then
24 gl_REPLACE_FCNTL
25 else
26 dnl cygwin 1.5.x F_DUPFD has wrong errno, and allows negative target
27 dnl haiku alpha 2 F_DUPFD has wrong errno
28 AC_CACHE_CHECK([whether fcntl handles F_DUPFD correctly],
29 [gl_cv_func_fcntl_f_dupfd_works],
30 [AC_RUN_IFELSE(
31 [AC_LANG_PROGRAM(
32 [[#include <errno.h>
33 #include <fcntl.h>
34 #include <limits.h>
35 #include <sys/resource.h>
36 #include <unistd.h>
37 ]GL_MDA_DEFINES[
38 #ifndef RLIM_SAVED_CUR
39 # define RLIM_SAVED_CUR RLIM_INFINITY
40 #endif
41 #ifndef RLIM_SAVED_MAX
42 # define RLIM_SAVED_MAX RLIM_INFINITY
43 #endif
44 ]],
45 [[int result = 0;
46 int bad_fd = INT_MAX;
47 struct rlimit rlim;
48 if (getrlimit (RLIMIT_NOFILE, &rlim) == 0
49 && 0 <= rlim.rlim_cur && rlim.rlim_cur <= INT_MAX
50 && rlim.rlim_cur != RLIM_INFINITY
51 && rlim.rlim_cur != RLIM_SAVED_MAX
52 && rlim.rlim_cur != RLIM_SAVED_CUR)
53 bad_fd = rlim.rlim_cur;
54 if (fcntl (0, F_DUPFD, -1) != -1) result |= 1;
55 if (errno != EINVAL) result |= 2;
56 if (fcntl (0, F_DUPFD, bad_fd) != -1) result |= 4;
57 if (errno != EINVAL) result |= 8;
58 /* On OS/2 kLIBC, F_DUPFD does not work on a directory fd */
59 {
60 int fd;
61 fd = open (".", O_RDONLY);
62 if (fd == -1)
63 result |= 16;
64 else if (fcntl (fd, F_DUPFD, STDERR_FILENO + 1) == -1)
65 result |= 32;
66
67 close (fd);
68 }
69 return result;]])],
70 [gl_cv_func_fcntl_f_dupfd_works=yes],
71 [gl_cv_func_fcntl_f_dupfd_works=no],
72 [case $host_os in
73 aix* | cygwin* | haiku*)
74 gl_cv_func_fcntl_f_dupfd_works="guessing no" ;;
75 *) gl_cv_func_fcntl_f_dupfd_works="guessing yes" ;;
76 esac])])
77 case $gl_cv_func_fcntl_f_dupfd_works in
78 *yes) ;;
79 *) gl_REPLACE_FCNTL
80 AC_DEFINE([FCNTL_DUPFD_BUGGY], [1], [Define this to 1 if F_DUPFD
81 behavior does not match POSIX]) ;;
82 esac
83
84 dnl Many systems lack F_DUPFD_CLOEXEC.
85 dnl NetBSD 9.0 declares F_DUPFD_CLOEXEC but it works only like F_DUPFD.
86 AC_CACHE_CHECK([whether fcntl understands F_DUPFD_CLOEXEC],
87 [gl_cv_func_fcntl_f_dupfd_cloexec],
88 [AC_RUN_IFELSE(
89 [AC_LANG_SOURCE(
90 [[#include <fcntl.h>
91 #include <unistd.h>
92 int main (int argc, char *argv[])
93 {
94 if (argc == 1)
95 /* parent process */
96 {
97 if (fcntl (1, F_DUPFD_CLOEXEC, 10) < 0)
98 return 1;
99 return execl ("./conftest", "./conftest", "child", NULL);
100 }
101 else
102 /* child process */
103 return (fcntl (10, F_GETFL) < 0 ? 0 : 42);
104 }
105 ]])
106 ],
107 [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
108#ifdef __linux__
109/* The Linux kernel only added F_DUPFD_CLOEXEC in 2.6.24, so we always replace
110 it to support the semantics on older kernels that failed with EINVAL. */
111choke me
112#endif
113 ]])],
114 [gl_cv_func_fcntl_f_dupfd_cloexec=yes],
115 [gl_cv_func_fcntl_f_dupfd_cloexec="needs runtime check"])
116 ],
117 [gl_cv_func_fcntl_f_dupfd_cloexec=no],
118 [case "$host_os" in
119 # Guess no on NetBSD.
120 netbsd*) gl_cv_func_fcntl_f_dupfd_cloexec="guessing no" ;;
121 *) gl_cv_func_fcntl_f_dupfd_cloexec="$gl_cross_guess_normal" ;;
122 esac
123 ])
124 ])
125 case "$gl_cv_func_fcntl_f_dupfd_cloexec" in
126 *yes) ;;
127 *) gl_REPLACE_FCNTL
128 dnl No witness macro needed for this bug.
129 ;;
130 esac
131 fi
132 dnl Replace fcntl() for supporting the gnulib-defined fchdir() function,
133 dnl to keep fchdir's bookkeeping up-to-date.
134 m4_ifdef([gl_FUNC_FCHDIR], [
135 gl_TEST_FCHDIR
136 if test $HAVE_FCHDIR = 0; then
137 gl_REPLACE_FCNTL
138 fi
139 ])
140])
141
142AC_DEFUN([gl_REPLACE_FCNTL],
143[
144 AC_REQUIRE([gl_FCNTL_H_DEFAULTS])
145 AC_CHECK_FUNCS_ONCE([fcntl])
146 if test $ac_cv_func_fcntl = no; then
147 HAVE_FCNTL=0
148 else
149 REPLACE_FCNTL=1
150 fi
151])