diff options
Diffstat (limited to 'gnulib/import/m4/dup2.m4')
-rw-r--r-- | gnulib/import/m4/dup2.m4 | 184 |
1 files changed, 86 insertions, 98 deletions
diff --git a/gnulib/import/m4/dup2.m4 b/gnulib/import/m4/dup2.m4 index 21b1ecc..0753a32 100644 --- a/gnulib/import/m4/dup2.m4 +++ b/gnulib/import/m4/dup2.m4 @@ -1,5 +1,5 @@ -#serial 25 -dnl Copyright (C) 2002, 2005, 2007, 2009-2020 Free Software Foundation, Inc. +#serial 27 +dnl Copyright (C) 2002, 2005, 2007, 2009-2021 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. @@ -8,107 +8,95 @@ AC_DEFUN([gl_FUNC_DUP2], [ AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) AC_REQUIRE([AC_CANONICAL_HOST]) - m4_ifdef([gl_FUNC_DUP2_OBSOLETE], [ - AC_CHECK_FUNCS_ONCE([dup2]) - if test $ac_cv_func_dup2 = no; then - HAVE_DUP2=0 - fi - ], [ - AC_DEFINE([HAVE_DUP2], [1], [Define to 1 if you have the 'dup2' function.]) - ]) - if test $HAVE_DUP2 = 1; then - AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works], - [AC_RUN_IFELSE([ - AC_LANG_PROGRAM( - [[#include <errno.h> - #include <fcntl.h> - #include <limits.h> - #include <sys/resource.h> - #include <unistd.h> - #ifndef RLIM_SAVED_CUR - # define RLIM_SAVED_CUR RLIM_INFINITY - #endif - #ifndef RLIM_SAVED_MAX - # define RLIM_SAVED_MAX RLIM_INFINITY - #endif - ]], - [[int result = 0; - int bad_fd = INT_MAX; - struct rlimit rlim; - if (getrlimit (RLIMIT_NOFILE, &rlim) == 0 - && 0 <= rlim.rlim_cur && rlim.rlim_cur <= INT_MAX - && rlim.rlim_cur != RLIM_INFINITY - && rlim.rlim_cur != RLIM_SAVED_MAX - && rlim.rlim_cur != RLIM_SAVED_CUR) - bad_fd = rlim.rlim_cur; - #ifdef FD_CLOEXEC - if (fcntl (1, F_SETFD, FD_CLOEXEC) == -1) - result |= 1; - #endif - if (dup2 (1, 1) != 1) - result |= 2; - #ifdef FD_CLOEXEC - if (fcntl (1, F_GETFD) != FD_CLOEXEC) - result |= 4; - #endif - close (0); - if (dup2 (0, 0) != -1) - result |= 8; - /* Many gnulib modules require POSIX conformance of EBADF. */ - if (dup2 (2, bad_fd) == -1 && errno != EBADF) - result |= 16; - /* Flush out some cygwin core dumps. */ - if (dup2 (2, -1) != -1 || errno != EBADF) - result |= 32; - dup2 (2, 255); - dup2 (2, 256); - /* On OS/2 kLIBC, dup2() does not work on a directory fd. */ - { - int fd = open (".", O_RDONLY); - if (fd == -1) - result |= 64; - else if (dup2 (fd, fd + 1) == -1) - result |= 128; - - close (fd); - } - return result;]]) - ], - [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no], - [case "$host_os" in - mingw*) # on this platform, dup2 always returns 0 for success - gl_cv_func_dup2_works="guessing no" ;; - cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0 - gl_cv_func_dup2_works="guessing no" ;; - aix* | freebsd*) - # on AIX 7.1 and FreeBSD 6.1, dup2 (1,toobig) gives EMFILE, - # not EBADF. - gl_cv_func_dup2_works="guessing no" ;; - haiku*) # on Haiku alpha 2, dup2(1, 1) resets FD_CLOEXEC. - gl_cv_func_dup2_works="guessing no" ;; - *-android*) # implemented using dup3(), which fails if oldfd == newfd - gl_cv_func_dup2_works="guessing no" ;; - os2*) # on OS/2 kLIBC, dup2() does not work on a directory fd. - gl_cv_func_dup2_works="guessing no" ;; - *) gl_cv_func_dup2_works="guessing yes" ;; - esac]) - ]) - case "$gl_cv_func_dup2_works" in - *yes) ;; - *) - REPLACE_DUP2=1 - AC_CHECK_FUNCS([setdtablesize]) - ;; - esac - fi + AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works], + [AC_RUN_IFELSE([ + AC_LANG_PROGRAM( + [[#include <errno.h> + #include <fcntl.h> + #include <limits.h> + #include <sys/resource.h> + #include <unistd.h> + ]GL_MDA_DEFINES[ + #ifndef RLIM_SAVED_CUR + # define RLIM_SAVED_CUR RLIM_INFINITY + #endif + #ifndef RLIM_SAVED_MAX + # define RLIM_SAVED_MAX RLIM_INFINITY + #endif + ]], + [[int result = 0; + int bad_fd = INT_MAX; + struct rlimit rlim; + if (getrlimit (RLIMIT_NOFILE, &rlim) == 0 + && 0 <= rlim.rlim_cur && rlim.rlim_cur <= INT_MAX + && rlim.rlim_cur != RLIM_INFINITY + && rlim.rlim_cur != RLIM_SAVED_MAX + && rlim.rlim_cur != RLIM_SAVED_CUR) + bad_fd = rlim.rlim_cur; + #ifdef FD_CLOEXEC + if (fcntl (1, F_SETFD, FD_CLOEXEC) == -1) + result |= 1; + #endif + if (dup2 (1, 1) != 1) + result |= 2; + #ifdef FD_CLOEXEC + if (fcntl (1, F_GETFD) != FD_CLOEXEC) + result |= 4; + #endif + close (0); + if (dup2 (0, 0) != -1) + result |= 8; + /* Many gnulib modules require POSIX conformance of EBADF. */ + if (dup2 (2, bad_fd) == -1 && errno != EBADF) + result |= 16; + /* Flush out some cygwin core dumps. */ + if (dup2 (2, -1) != -1 || errno != EBADF) + result |= 32; + dup2 (2, 255); + dup2 (2, 256); + /* On OS/2 kLIBC, dup2() does not work on a directory fd. */ + { + int fd = open (".", O_RDONLY); + if (fd == -1) + result |= 64; + else if (dup2 (fd, fd + 1) == -1) + result |= 128; + close (fd); + } + return result;]]) + ], + [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no], + [case "$host_os" in + mingw*) # on this platform, dup2 always returns 0 for success + gl_cv_func_dup2_works="guessing no" ;; + cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0 + gl_cv_func_dup2_works="guessing no" ;; + aix* | freebsd*) + # on AIX 7.1 and FreeBSD 6.1, dup2 (1,toobig) gives EMFILE, + # not EBADF. + gl_cv_func_dup2_works="guessing no" ;; + haiku*) # on Haiku alpha 2, dup2(1, 1) resets FD_CLOEXEC. + gl_cv_func_dup2_works="guessing no" ;; + *-android*) # implemented using dup3(), which fails if oldfd == newfd + gl_cv_func_dup2_works="guessing no" ;; + os2*) # on OS/2 kLIBC, dup2() does not work on a directory fd. + gl_cv_func_dup2_works="guessing no" ;; + *) gl_cv_func_dup2_works="guessing yes" ;; + esac]) + ]) + case "$gl_cv_func_dup2_works" in + *yes) ;; + *) + REPLACE_DUP2=1 + AC_CHECK_FUNCS([setdtablesize]) + ;; + esac dnl Replace dup2() 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 - if test $HAVE_DUP2 = 1; then - REPLACE_DUP2=1 - fi + REPLACE_DUP2=1 fi ]) ]) |