-#serial 10
-dnl Copyright (C) 2002, 2005, 2007, 2009-2010 Free Software Foundation, Inc.
+#serial 20
+dnl Copyright (C) 2002, 2005, 2007, 2009-2014 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.
[
AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
AC_REQUIRE([AC_CANONICAL_HOST])
- AC_CHECK_FUNCS_ONCE([dup2])
- if test $ac_cv_func_dup2 = no; then
- HAVE_DUP2=0
- AC_LIBOBJ([dup2])
- else
+ 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 $HAVE_DUP2 = 1; then
AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works],
[AC_RUN_IFELSE([
AC_LANG_PROGRAM([[#include <unistd.h>
+#include <fcntl.h>
#include <errno.h>]],
- [if (dup2 (1, 1) == 0)
- return 1;
+ [int result = 0;
+#ifdef FD_CLOEXEC
+ if (fcntl (1, F_SETFD, FD_CLOEXEC) == -1)
+ result |= 1;
+#endif
+ if (dup2 (1, 1) == 0)
+ result |= 2;
+#ifdef FD_CLOEXEC
+ if (fcntl (1, F_GETFD) != FD_CLOEXEC)
+ result |= 4;
+#endif
close (0);
if (dup2 (0, 0) != -1)
- return 2;
+ result |= 8;
/* Many gnulib modules require POSIX conformance of EBADF. */
- if (dup2 (1, 1000000) == -1 && errno != EBADF)
- return 3;
- return 0;
+ if (dup2 (2, 1000000) == -1 && errno != EBADF)
+ result |= 16;
+ /* Flush out some cygwin core dumps. */
+ if (dup2 (2, -1) != -1 || errno != EBADF)
+ result |= 32;
+ dup2 (2, 255);
+ dup2 (2, 256);
+ return result;
])
],
[gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no],
[case "$host_os" in
mingw*) # on this platform, dup2 always returns 0 for success
- gl_cv_func_dup2_works=no;;
+ gl_cv_func_dup2_works="guessing no" ;;
cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0
- gl_cv_func_dup2_works=no;;
+ gl_cv_func_dup2_works="guessing no" ;;
linux*) # On linux between 2008-07-27 and 2009-05-11, dup2 of a
# closed fd may yield -EBADF instead of -1 / errno=EBADF.
- gl_cv_func_dup2_works=no;;
+ gl_cv_func_dup2_works="guessing no" ;;
freebsd*) # on FreeBSD 6.1, dup2(1,1000000) gives EMFILE, not EBADF.
- gl_cv_func_dup2_works=no;;
- *) gl_cv_func_dup2_works=yes;;
+ 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" ;;
+ *) gl_cv_func_dup2_works="guessing yes" ;;
esac])
])
- if test "$gl_cv_func_dup2_works" = no; then
- gl_REPLACE_DUP2
- fi
+ case "$gl_cv_func_dup2_works" in
+ *yes) ;;
+ *)
+ REPLACE_DUP2=1
+ AC_CHECK_FUNCS([setdtablesize])
+ ;;
+ esac
fi
+ 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
+ fi
+ ])
])
-AC_DEFUN([gl_REPLACE_DUP2],
-[
- AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
- if test $ac_cv_func_dup2 = yes; then
- REPLACE_DUP2=1
- fi
- AC_LIBOBJ([dup2])
-])
+# Prerequisites of lib/dup2.c.
+AC_DEFUN([gl_PREREQ_DUP2], [])