3 dnl Copyright (C) 2000-2001, 2003-2007, 2009-2024 Free Software Foundation, Inc.
4 dnl This file is free software; the Free Software Foundation
5 dnl gives unlimited permission to copy and/or distribute it,
6 dnl with or without modifications, as long as this notice is preserved.
8 # See if we need to emulate a missing ftruncate function using _chsize.
10 AC_DEFUN([gl_FUNC_FTRUNCATE],
12 AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
13 gl_CHECK_FUNCS_ANDROID([ftruncate], [[#include <unistd.h>]])
14 if test $ac_cv_func_ftruncate = yes; then
15 m4_ifdef([gl_LARGEFILE], [
16 AC_REQUIRE([AC_CANONICAL_HOST])
19 dnl Native Windows, and Large File Support is requested.
20 dnl The MSVCRT _chsize() function only accepts a 32-bit file size,
21 dnl and the mingw64 ftruncate64() function is unreliable (it may
22 dnl delete the file, see
23 dnl <https://web.archive.org/web/20160425005423/http://mingw-w64.sourcearchive.com/documentation/2.0-1/ftruncate64_8c_source.html>).
24 dnl Use gnulib's ftruncate() implementation instead.
33 case "$gl_cv_onwards_func_ftruncate" in
34 future*) REPLACE_FTRUNCATE=1 ;;
39 # Prerequisites of lib/ftruncate.c.
40 AC_DEFUN([gl_PREREQ_FTRUNCATE],
42 AC_CHECK_FUNCS([_chsize])