-#serial 6
-dnl Copyright (C) 2002, 2005, 2007, 2009 Free Software Foundation, Inc.
+#serial 10
+dnl Copyright (C) 2002, 2005, 2007, 2009-2010 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_LIBOBJ([dup2])
else
AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works],
- [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
-#include <unistd.h>
-]], [return 1 - dup2 (1, 1);])],
- [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no],
- [case "$host_os" in
- mingw*) # on this platform, dup2 always returns 0 for success
- gl_cv_func_dup2_works=no;;
- cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0
- gl_cv_func_dup2_works=no;;
- *) gl_cv_func_dup2_works=yes;;
- esac])])
+ [AC_RUN_IFELSE([
+ AC_LANG_PROGRAM([[#include <unistd.h>
+#include <errno.h>]],
+ [if (dup2 (1, 1) == 0)
+ return 1;
+ close (0);
+ if (dup2 (0, 0) != -1)
+ return 2;
+ /* Many gnulib modules require POSIX conformance of EBADF. */
+ if (dup2 (1, 1000000) == -1 && errno != EBADF)
+ return 3;
+ return 0;
+ ])
+ ],
+ [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no],
+ [case "$host_os" in
+ mingw*) # on this platform, dup2 always returns 0 for success
+ gl_cv_func_dup2_works=no;;
+ cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0
+ gl_cv_func_dup2_works=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;;
+ freebsd*) # on FreeBSD 6.1, dup2(1,1000000) gives EMFILE, not EBADF.
+ gl_cv_func_dup2_works=no;;
+ *) gl_cv_func_dup2_works=yes;;
+ esac])
+ ])
if test "$gl_cv_func_dup2_works" = no; then
- REPLACE_DUP2=1
- AC_LIBOBJ([dup2])
+ gl_REPLACE_DUP2
fi
fi
- AC_DEFINE_UNQUOTED([REPLACE_DUP2], [$REPLACE_DUP2],
- [Define to 1 if dup2 returns 0 instead of the target fd.])
+])
+
+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])
])