diff options
Diffstat (limited to 'm4/fcntl.m4')
| -rw-r--r-- | m4/fcntl.m4 | 52 |
1 files changed, 38 insertions, 14 deletions
diff --git a/m4/fcntl.m4 b/m4/fcntl.m4 index ea24f3d64ef..547ff40b804 100644 --- a/m4/fcntl.m4 +++ b/m4/fcntl.m4 @@ -1,4 +1,4 @@ -# fcntl.m4 serial 10 +# fcntl.m4 serial 11 dnl Copyright (C) 2009-2020 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -81,15 +81,29 @@ AC_DEFUN([gl_FUNC_FCNTL], behavior does not match POSIX]) ;; esac - dnl Many systems lack F_DUPFD_CLOEXEC + 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_COMPILE_IFELSE([AC_LANG_PROGRAM([[ -#include <fcntl.h> -#ifndef F_DUPFD_CLOEXEC -choke me -#endif - ]])], + [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 @@ -98,12 +112,22 @@ 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])]) - if test "$gl_cv_func_fcntl_f_dupfd_cloexec" != yes; then - gl_REPLACE_FCNTL - dnl No witness macro needed for this bug. - fi + [gl_cv_func_fcntl_f_dupfd_cloexec="needs runtime check"]) + ], + [gl_cv_func_fcntl_f_dupfd_cloexec=no], + [case "$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. |