wget/m4/fseeko.m4

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# fseeko.m4 serial 19
dnl Copyright (C) 2007-2019 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_FSEEKO],
[
AC_REQUIRE([gl_STDIO_H_DEFAULTS])
AC_REQUIRE([gl_STDIN_LARGE_OFFSET])
AC_REQUIRE([gl_SYS_TYPES_H])
AC_REQUIRE([AC_PROG_CC])
dnl Persuade glibc <stdio.h> to declare fseeko().
AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
AC_CACHE_CHECK([for fseeko], [gl_cv_func_fseeko],
[
AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>
]], [fseeko (stdin, 0, 0);])],
[gl_cv_func_fseeko=yes], [gl_cv_func_fseeko=no])
])
AC_CHECK_DECLS_ONCE([fseeko])
if test $ac_cv_have_decl_fseeko = no; then
HAVE_DECL_FSEEKO=0
fi
if test $gl_cv_func_fseeko = no; then
HAVE_FSEEKO=0
else
if test $WINDOWS_64_BIT_OFF_T = 1; then
REPLACE_FSEEKO=1
fi
if test $gl_cv_var_stdin_large_offset = no; then
REPLACE_FSEEKO=1
fi
m4_ifdef([gl_FUNC_FFLUSH_STDIN], [
gl_FUNC_FFLUSH_STDIN
case "$gl_cv_func_fflush_stdin" in
*yes) ;;
*) REPLACE_FSEEKO=1 ;;
esac
])
fi
])
dnl Code shared by fseeko and ftello. Determine if large files are supported,
dnl but stdin does not start as a large file by default.
AC_DEFUN([gl_STDIN_LARGE_OFFSET],
[
AC_CACHE_CHECK([whether stdin defaults to large file offsets],
[gl_cv_var_stdin_large_offset],
[AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>]],
[[#if defined __SL64 && defined __SCLE /* cygwin */
/* Cygwin 1.5.24 and earlier fail to put stdin in 64-bit mode, making
fseeko/ftello needlessly fail. This bug was fixed in 1.5.25, and
it is easier to do a version check than building a runtime test. */
# include <cygwin/version.h>
# if CYGWIN_VERSION_DLL_COMBINED < CYGWIN_VERSION_DLL_MAKE_COMBINED (1005, 25)
choke me
# endif
#endif]])],
[gl_cv_var_stdin_large_offset=yes],
[gl_cv_var_stdin_large_offset=no])])
])
# Prerequisites of lib/fseeko.c.
AC_DEFUN([gl_PREREQ_FSEEKO],
[
dnl Native Windows has the function _fseeki64. mingw hides it in some
dnl circumstances, but mingw64 makes it usable again.
AC_CHECK_FUNCS([_fseeki64])
if test $ac_cv_func__fseeki64 = yes; then
AC_CHECK_DECLS([_fseeki64])
fi
])