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9c9d63b1 PM |
1 | # dup.m4 serial 7 |
2 | dnl Copyright (C) 2011-2021 Free Software Foundation, Inc. | |
6ec2e0f5 SDJ |
3 | dnl This file is free software; the Free Software Foundation |
4 | dnl gives unlimited permission to copy and/or distribute it, | |
5 | dnl with or without modifications, as long as this notice is preserved. | |
6 | ||
7 | AC_DEFUN([gl_FUNC_DUP], | |
8 | [ | |
9 | AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) | |
c0c3707f CB |
10 | AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles |
11 | m4_ifdef([gl_MSVC_INVAL], [ | |
12 | AC_REQUIRE([gl_MSVC_INVAL]) | |
13 | if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then | |
14 | REPLACE_DUP=1 | |
15 | fi | |
16 | ]) | |
6ec2e0f5 SDJ |
17 | dnl Replace dup() for supporting the gnulib-defined fchdir() function, |
18 | dnl to keep fchdir's bookkeeping up-to-date. | |
19 | m4_ifdef([gl_FUNC_FCHDIR], [ | |
20 | gl_TEST_FCHDIR | |
21 | if test $HAVE_FCHDIR = 0; then | |
22 | REPLACE_DUP=1 | |
23 | fi | |
24 | ]) | |
25 | AC_CACHE_CHECK([whether dup works], [gl_cv_func_dup_works], | |
26 | [AC_RUN_IFELSE( | |
27 | [AC_LANG_PROGRAM([[#include <unistd.h> | |
28 | #include <fcntl.h> | |
9c9d63b1 PM |
29 | #include <errno.h> |
30 | ]GL_MDA_DEFINES], | |
6ec2e0f5 SDJ |
31 | [[/* On OS/2 kLIBC, dup does not work on a directory fd. */ |
32 | int fd = open (".", O_RDONLY); | |
33 | return fd < 0 ? 1 : dup (fd) < 0 ? 2 : 0; | |
34 | ]]) | |
35 | ], | |
36 | [gl_cv_func_dup_works=yes], | |
37 | [gl_cv_func_dup_works=no], | |
c0c3707f CB |
38 | [case "$host_os" in |
39 | # Guess no on native Windows. | |
40 | mingw*) gl_cv_func_dup_works="guessing no" ;; | |
41 | *) gl_cv_func_dup_works="guessing yes" ;; | |
42 | esac | |
43 | ]) | |
6ec2e0f5 SDJ |
44 | ]) |
45 | case "$gl_cv_func_dup_works" in | |
46 | *yes) ;; | |
47 | *) | |
48 | REPLACE_DUP=1 | |
49 | ;; | |
50 | esac | |
51 | ]) | |
52 | ||
53 | # Prerequisites of lib/dup.c. | |
54 | AC_DEFUN([gl_PREREQ_DUP], [:]) |