2 dnl Copyright (C) 2007-2011 Free Software Foundation, Inc.
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.
7 AC_DEFUN([gl_FUNC_FSEEKO],
9 AC_REQUIRE([gl_STDIO_H_DEFAULTS])
10 AC_REQUIRE([gl_HAVE_FSEEKO])
11 AC_REQUIRE([gl_STDIN_LARGE_OFFSET])
13 AC_CHECK_DECLS_ONCE([fseeko])
14 if test $ac_cv_have_decl_fseeko = no; then
18 if test $gl_cv_func_fseeko = no; then
21 if test $gl_cv_var_stdin_large_offset = no; then
24 m4_ifdef([gl_FUNC_FFLUSH_STDIN], [
26 if test $gl_cv_func_fflush_stdin = no; then
33 dnl Tests whether fseeko is available.
34 dnl Result is gl_cv_func_fseeko.
35 AC_DEFUN([gl_HAVE_FSEEKO],
37 AC_REQUIRE([AC_PROG_CC])
39 dnl Persuade glibc <stdio.h> to declare fseeko().
40 AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
42 AC_CACHE_CHECK([for fseeko], [gl_cv_func_fseeko],
44 AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>
45 ]], [fseeko (stdin, 0, 0);])],
46 [gl_cv_func_fseeko=yes], [gl_cv_func_fseeko=no])
50 dnl Code shared by fseeko and ftello. Determine if large files are supported,
51 dnl but stdin does not start as a large file by default.
52 AC_DEFUN([gl_STDIN_LARGE_OFFSET],
54 AC_CACHE_CHECK([whether stdin defaults to large file offsets],
55 [gl_cv_var_stdin_large_offset],
56 [AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>]],
57 [[#if defined __SL64 && defined __SCLE /* cygwin */
58 /* Cygwin 1.5.24 and earlier fail to put stdin in 64-bit mode, making
59 fseeko/ftello needlessly fail. This bug was fixed in 1.5.25, and
60 it is easier to do a version check than building a runtime test. */
61 # include <cygwin/version.h>
62 # if CYGWIN_VERSION_DLL_COMBINED < CYGWIN_VERSION_DLL_MAKE_COMBINED (1005, 25)
66 [gl_cv_var_stdin_large_offset=yes],
67 [gl_cv_var_stdin_large_offset=no])])