-# dup.m4 serial 3
-dnl Copyright (C) 2011-2013 Free Software Foundation, Inc.
+# dup.m4 serial 6
+dnl Copyright (C) 2011-2018 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_DEFUN([gl_FUNC_DUP],
[
AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
- AC_REQUIRE([gl_MSVC_INVAL])
- if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
- REPLACE_DUP=1
- fi
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ m4_ifdef([gl_MSVC_INVAL], [
+ AC_REQUIRE([gl_MSVC_INVAL])
+ if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then
+ REPLACE_DUP=1
+ fi
+ ])
dnl Replace dup() for supporting the gnulib-defined fchdir() function,
dnl to keep fchdir's bookkeeping up-to-date.
m4_ifdef([gl_FUNC_FCHDIR], [
REPLACE_DUP=1
fi
])
+ AC_CACHE_CHECK([whether dup works], [gl_cv_func_dup_works],
+ [AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM([[#include <unistd.h>
+ #include <fcntl.h>
+ #include <errno.h>]],
+ [[/* On OS/2 kLIBC, dup does not work on a directory fd. */
+ int fd = open (".", O_RDONLY);
+ return fd < 0 ? 1 : dup (fd) < 0 ? 2 : 0;
+ ]])
+ ],
+ [gl_cv_func_dup_works=yes],
+ [gl_cv_func_dup_works=no],
+ [case "$host_os" in
+ # Guess no on native Windows.
+ mingw*) gl_cv_func_dup_works="guessing no" ;;
+ *) gl_cv_func_dup_works="guessing yes" ;;
+ esac
+ ])
+ ])
+ case "$gl_cv_func_dup_works" in
+ *yes) ;;
+ *)
+ REPLACE_DUP=1
+ ;;
+ esac
])
# Prerequisites of lib/dup.c.