3 # Copyright (C) 2000, 2001, 2004, 2005, 2006 Free Software Foundation, Inc.
4 # This file is free software; the Free Software Foundation
5 # gives unlimited permission to copy and/or distribute it,
6 # with or without modifications, as long as this notice is preserved.
9 dnl Using code from emacs, based on suggestions from Paul Eggert
10 dnl and Ulrich Drepper.
12 dnl Find out how to determine the number of pending output bytes on a stream.
13 dnl glibc (2.1.93 and newer) and Solaris provide __fpending. On other systems,
14 dnl we have to grub around in the FILE struct.
16 AC_DEFUN([gl_FUNC_FPENDING],
18 AC_CHECK_HEADERS_ONCE(stdio_ext.h)
19 AC_REPLACE_FUNCS([__fpending])
23 # include <stdio_ext.h>
26 AC_CHECK_DECLS([__fpending], , , $fp_headers)
27 if test $ac_cv_func___fpending = no; then
29 [how to determine the number of pending output bytes on a stream],
30 ac_cv_sys_pending_output_n_bytes,
35 'fp->_IO_write_ptr - fp->_IO_write_base' \
37 '# traditional Unix' \
38 'fp->_ptr - fp->_base' \
41 'fp->_p - fp->_bf._base' \
44 '(fp->__ptr ? fp->__ptr - fp->__base : 0)' \
47 'fp->__bufp - fp->__buffer' \
49 '# old glibc iostream?' \
50 'fp->_pptr - fp->_pbase' \
53 '(*fp)->_ptr - (*fp)->_base' \
55 '# e.g., DGUX R4.11; the info is not available' \
59 # Skip each embedded comment.
60 case "$ac_expr" in '#'*) continue;; esac
65 [FILE *fp = stdin; (void) ($ac_expr);],
68 test "$fp_done" = yes && break
71 ac_cv_sys_pending_output_n_bytes=$ac_expr
74 AC_DEFINE_UNQUOTED(PENDING_OUTPUT_N_BYTES,
75 $ac_cv_sys_pending_output_n_bytes,
76 [the number of pending output bytes on stream `fp'])