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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:37:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:37:10 +0000 |
commit | c9addba5cc770d2d231b34f6739f32c6be8690f1 (patch) | |
tree | c643da154a95a1d163137135050bb47858a1654e /gl/m4/fcntl.m4 | |
parent | Initial commit. (diff) | |
download | man-db-c9addba5cc770d2d231b34f6739f32c6be8690f1.tar.xz man-db-c9addba5cc770d2d231b34f6739f32c6be8690f1.zip |
Adding upstream version 2.12.0.upstream/2.12.0
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gl/m4/fcntl.m4')
-rw-r--r-- | gl/m4/fcntl.m4 | 151 |
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 @@ +# fcntl.m4 serial 11 +dnl Copyright (C) 2009-2023 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. + +# For now, this module ensures that fcntl() +# - supports F_DUPFD correctly +# - supports or emulates F_DUPFD_CLOEXEC +# - supports F_GETFD +# Still to be ported to mingw: +# - F_SETFD +# - F_GETFL, F_SETFL +# - F_GETOWN, F_SETOWN +# - F_GETLK, F_SETLK, F_SETLKW +AC_DEFUN([gl_FUNC_FCNTL], +[ + dnl Persuade glibc to expose F_DUPFD_CLOEXEC. + AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) + AC_REQUIRE([gl_FCNTL_H_DEFAULTS]) + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_CHECK_FUNCS_ONCE([fcntl]) + if test $ac_cv_func_fcntl = no; then + gl_REPLACE_FCNTL + else + dnl cygwin 1.5.x F_DUPFD has wrong errno, and allows negative target + dnl haiku alpha 2 F_DUPFD has wrong errno + AC_CACHE_CHECK([whether fcntl handles F_DUPFD correctly], + [gl_cv_func_fcntl_f_dupfd_works], + [AC_RUN_IFELSE( + [AC_LANG_PROGRAM( + [[#include <errno.h> + #include <fcntl.h> + #include <limits.h> + #include <sys/resource.h> + #include <unistd.h> + ]GL_MDA_DEFINES[ + #ifndef RLIM_SAVED_CUR + # define RLIM_SAVED_CUR RLIM_INFINITY + #endif + #ifndef RLIM_SAVED_MAX + # define RLIM_SAVED_MAX RLIM_INFINITY + #endif + ]], + [[int result = 0; + int bad_fd = INT_MAX; + struct rlimit rlim; + if (getrlimit (RLIMIT_NOFILE, &rlim) == 0 + && 0 <= rlim.rlim_cur && rlim.rlim_cur <= INT_MAX + && rlim.rlim_cur != RLIM_INFINITY + && rlim.rlim_cur != RLIM_SAVED_MAX + && rlim.rlim_cur != RLIM_SAVED_CUR) + bad_fd = rlim.rlim_cur; + if (fcntl (0, F_DUPFD, -1) != -1) result |= 1; + if (errno != EINVAL) result |= 2; + if (fcntl (0, F_DUPFD, bad_fd) != -1) result |= 4; + if (errno != EINVAL) result |= 8; + /* On OS/2 kLIBC, F_DUPFD does not work on a directory fd */ + { + int fd; + fd = open (".", O_RDONLY); + if (fd == -1) + result |= 16; + else if (fcntl (fd, F_DUPFD, STDERR_FILENO + 1) == -1) + result |= 32; + + close (fd); + } + return result;]])], + [gl_cv_func_fcntl_f_dupfd_works=yes], + [gl_cv_func_fcntl_f_dupfd_works=no], + [case $host_os in + aix* | cygwin* | haiku*) + gl_cv_func_fcntl_f_dupfd_works="guessing no" ;; + *) gl_cv_func_fcntl_f_dupfd_works="guessing yes" ;; + esac])]) + case $gl_cv_func_fcntl_f_dupfd_works in + *yes) ;; + *) gl_REPLACE_FCNTL + AC_DEFINE([FCNTL_DUPFD_BUGGY], [1], [Define this to 1 if F_DUPFD + behavior does not match POSIX]) ;; + esac + + dnl Many systems lack F_DUPFD_CLOEXEC. + dnl NetBSD 9.0 declares F_DUPFD_CLOEXEC but it works only like F_DUPFD. + AC_CACHE_CHECK([whether fcntl understands F_DUPFD_CLOEXEC], + [gl_cv_func_fcntl_f_dupfd_cloexec], + [AC_RUN_IFELSE( + [AC_LANG_SOURCE( + [[#include <fcntl.h> + #include <unistd.h> + int main (int argc, char *argv[]) + { + if (argc == 1) + /* parent process */ + { + if (fcntl (1, F_DUPFD_CLOEXEC, 10) < 0) + return 1; + return execl ("./conftest", "./conftest", "child", NULL); + } + else + /* child process */ + return (fcntl (10, F_GETFL) < 0 ? 0 : 42); + } + ]]) + ], + [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ +#ifdef __linux__ +/* The Linux kernel only added F_DUPFD_CLOEXEC in 2.6.24, so we always replace + it to support the semantics on older kernels that failed with EINVAL. */ +choke me +#endif + ]])], + [gl_cv_func_fcntl_f_dupfd_cloexec=yes], + [gl_cv_func_fcntl_f_dupfd_cloexec="needs runtime check"]) + ], + [gl_cv_func_fcntl_f_dupfd_cloexec=no], + [case "$host_os" in + # Guess no on NetBSD. + netbsd*) gl_cv_func_fcntl_f_dupfd_cloexec="guessing no" ;; + *) gl_cv_func_fcntl_f_dupfd_cloexec="$gl_cross_guess_normal" ;; + esac + ]) + ]) + case "$gl_cv_func_fcntl_f_dupfd_cloexec" in + *yes) ;; + *) gl_REPLACE_FCNTL + dnl No witness macro needed for this bug. + ;; + esac + fi + dnl Replace fcntl() for supporting the gnulib-defined fchdir() function, + dnl to keep fchdir's bookkeeping up-to-date. + m4_ifdef([gl_FUNC_FCHDIR], [ + gl_TEST_FCHDIR + if test $HAVE_FCHDIR = 0; then + gl_REPLACE_FCNTL + fi + ]) +]) + +AC_DEFUN([gl_REPLACE_FCNTL], +[ + AC_REQUIRE([gl_FCNTL_H_DEFAULTS]) + AC_CHECK_FUNCS_ONCE([fcntl]) + if test $ac_cv_func_fcntl = no; then + HAVE_FCNTL=0 + else + REPLACE_FCNTL=1 + fi +]) |