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5e8754f9 SDJ |
1 | # dup.m4 serial 4 |
2 | dnl Copyright (C) 2011-2016 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]) | |
5e8754f9 SDJ |
10 | AC_REQUIRE([gl_MSVC_INVAL]) |
11 | if test $HAVE_MSVC_INVALID_PARAMETER_HANDLER = 1; then | |
12 | REPLACE_DUP=1 | |
13 | fi | |
6ec2e0f5 SDJ |
14 | dnl Replace dup() for supporting the gnulib-defined fchdir() function, |
15 | dnl to keep fchdir's bookkeeping up-to-date. | |
16 | m4_ifdef([gl_FUNC_FCHDIR], [ | |
17 | gl_TEST_FCHDIR | |
18 | if test $HAVE_FCHDIR = 0; then | |
19 | REPLACE_DUP=1 | |
20 | fi | |
21 | ]) | |
22 | AC_CACHE_CHECK([whether dup works], [gl_cv_func_dup_works], | |
23 | [AC_RUN_IFELSE( | |
24 | [AC_LANG_PROGRAM([[#include <unistd.h> | |
25 | #include <fcntl.h> | |
26 | #include <errno.h>]], | |
27 | [[/* On OS/2 kLIBC, dup does not work on a directory fd. */ | |
28 | int fd = open (".", O_RDONLY); | |
29 | return fd < 0 ? 1 : dup (fd) < 0 ? 2 : 0; | |
30 | ]]) | |
31 | ], | |
32 | [gl_cv_func_dup_works=yes], | |
33 | [gl_cv_func_dup_works=no], | |
5e8754f9 | 34 | [gl_cv_func_dup_works='guessing yes']) |
6ec2e0f5 SDJ |
35 | ]) |
36 | case "$gl_cv_func_dup_works" in | |
37 | *yes) ;; | |
38 | *) | |
39 | REPLACE_DUP=1 | |
40 | ;; | |
41 | esac | |
42 | ]) | |
43 | ||
44 | # Prerequisites of lib/dup.c. | |
45 | AC_DEFUN([gl_PREREQ_DUP], [:]) |