| # dup.m4 serial 7 |
| dnl Copyright (C) 2011-2021 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. |
| |
| AC_DEFUN([gl_FUNC_DUP], |
| [ |
| AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) |
| 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], [ |
| gl_TEST_FCHDIR |
| if test $HAVE_FCHDIR = 0; then |
| REPLACE_DUP=1 |
| fi |
| ]) |
| AC_CACHE_CHECK([whether dup works], [gl_cv_func_dup_works], |
| [AC_RUN_IFELSE( |
| [AC_LANG_PROGRAM([[#include <unistd.h> |
| #include <fcntl.h> |
| #include <errno.h> |
| ]GL_MDA_DEFINES], |
| [[/* On OS/2 kLIBC, dup does not work on a directory fd. */ |
| int fd = open (".", O_RDONLY); |
| return fd < 0 ? 1 : dup (fd) < 0 ? 2 : 0; |
| ]]) |
| ], |
| [gl_cv_func_dup_works=yes], |
| [gl_cv_func_dup_works=no], |
| [case "$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. |
| AC_DEFUN([gl_PREREQ_DUP], [:]) |
