[bpt/emacs.git] / m4 / fpending.m4

# serial 21

# Copyright (C) 2000-2001, 2004-2014 Free Software Foundation, Inc.
# This file is free software; the Free Software Foundation
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.

dnl From Jim Meyering
dnl Using code from emacs, based on suggestions from Paul Eggert
dnl and Ulrich Drepper.

dnl Find out how to determine the number of pending output bytes on a stream.
dnl glibc (2.1.93 and newer) and Solaris provide __fpending.  On other systems,
dnl we have to grub around in the FILE struct.

AC_DEFUN([gl_FUNC_FPENDING],
[
  AC_CHECK_HEADERS_ONCE([stdio_ext.h])
  fp_headers='
    #include <stdio.h>
    #if HAVE_STDIO_EXT_H
    # include <stdio_ext.h>
    #endif
  '
  AC_CACHE_CHECK([for __fpending], [gl_cv_func___fpending],
    [
      AC_LINK_IFELSE(
        [AC_LANG_PROGRAM([$fp_headers],
           [[return ! __fpending (stdin);]])],
        [gl_cv_func___fpending=yes],
        [gl_cv_func___fpending=no])
    ])
  if test $gl_cv_func___fpending = yes; then
    AC_CHECK_DECLS([__fpending], [], [], [$fp_headers])
  fi
])

AC_DEFUN([gl_PREREQ_FPENDING],
[
  AC_CACHE_CHECK(
              [how to determine the number of pending output bytes on a stream],
                 ac_cv_sys_pending_output_n_bytes,
    [
      for ac_expr in                                                    \
                                                                        \
          '# glibc2'                                                    \
          'fp->_IO_write_ptr - fp->_IO_write_base'                      \
                                                                        \
          '# traditional Unix'                                          \
          'fp->_ptr - fp->_base'                                        \
                                                                        \
          '# BSD'                                                       \
          'fp->_p - fp->_bf._base'                                      \
                                                                        \
          '# SCO, Unixware'                                             \
          '(fp->__ptr ? fp->__ptr - fp->__base : 0)'                    \
                                                                        \
          '# QNX'                                                       \
          '(fp->_Mode & 0x2000 /*_MWRITE*/ ? fp->_Next - fp->_Buf : 0)' \
                                                                        \
          '# old glibc?'                                                \
          'fp->__bufp - fp->__buffer'                                   \
                                                                        \
          '# old glibc iostream?'                                       \
          'fp->_pptr - fp->_pbase'                                      \
                                                                        \
          '# emx+gcc'                                                   \
          'fp->_ptr - fp->_buffer'                                      \
                                                                        \
          '# Minix'                                                     \
          'fp->_ptr - fp->_buf'                                         \
                                                                        \
          '# Plan9'                                                     \
          'fp->wp - fp->buf'                                            \
                                                                        \
          '# VMS'                                                       \
          '(*fp)->_ptr - (*fp)->_base'                                  \
                                                                        \
          '# e.g., DGUX R4.11; the info is not available'               \
          1                                                             \
          ; do

        # Skip each embedded comment.
        case "$ac_expr" in '#'*) continue;; esac

        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>]],
          [[FILE *fp = stdin; (void) ($ac_expr);]])],
          [fp_done=yes]
        )
        test "$fp_done" = yes && break
      done

      ac_cv_sys_pending_output_n_bytes=$ac_expr
    ]
  )
  AC_DEFINE_UNQUOTED([PENDING_OUTPUT_N_BYTES],
    $ac_cv_sys_pending_output_n_bytes,
    [the number of pending output bytes on stream 'fp'])
])
Commit	Line	Data
220a304a	1	# serial 21
7ccfb720	2
ba318903	3	# Copyright (C) 2000-2001, 2004-2014 Free Software Foundation, Inc.
7ccfb720 PE	4	# This file is free software; the Free Software Foundation
	5	# gives unlimited permission to copy and/or distribute it,
	6	# with or without modifications, as long as this notice is preserved.
	7
	8	dnl From Jim Meyering
	9	dnl Using code from emacs, based on suggestions from Paul Eggert
	10	dnl and Ulrich Drepper.
	11
	12	dnl Find out how to determine the number of pending output bytes on a stream.
	13	dnl glibc (2.1.93 and newer) and Solaris provide __fpending. On other systems,
	14	dnl we have to grub around in the FILE struct.
	15
	16	AC_DEFUN([gl_FUNC_FPENDING],
	17	[
	18	AC_CHECK_HEADERS_ONCE([stdio_ext.h])
220a304a PE	19	fp_headers='
	20	#include <stdio.h>
	21	#if HAVE_STDIO_EXT_H
	22	# include <stdio_ext.h>
	23	#endif
	24	'
eaca0446 PE	25	AC_CACHE_CHECK([for __fpending], [gl_cv_func___fpending],
	26	[
	27	AC_LINK_IFELSE(
220a304a	28	[AC_LANG_PROGRAM([$fp_headers],
eaca0446 PE	29	[[return ! __fpending (stdin);]])],
	30	[gl_cv_func___fpending=yes],
	31	[gl_cv_func___fpending=no])
	32	])
220a304a PE	33	if test $gl_cv_func___fpending = yes; then
	34	AC_CHECK_DECLS([__fpending], [], [], [$fp_headers])
	35	fi
7ccfb720 PE	36	])
	37
	38	AC_DEFUN([gl_PREREQ_FPENDING],
	39	[
	40	AC_CACHE_CHECK(
	41	[how to determine the number of pending output bytes on a stream],
	42	ac_cv_sys_pending_output_n_bytes,
	43	[
	44	for ac_expr in \
	45	\
	46	'# glibc2' \
	47	'fp->_IO_write_ptr - fp->_IO_write_base' \
	48	\
	49	'# traditional Unix' \
	50	'fp->_ptr - fp->_base' \
	51	\
	52	'# BSD' \
	53	'fp->_p - fp->_bf._base' \
	54	\
	55	'# SCO, Unixware' \
	56	'(fp->__ptr ? fp->__ptr - fp->__base : 0)' \
	57	\
	58	'# QNX' \
	59	'(fp->_Mode & 0x2000 /_MWRITE/ ? fp->_Next - fp->_Buf : 0)' \
	60	\
	61	'# old glibc?' \
	62	'fp->__bufp - fp->__buffer' \
	63	\
	64	'# old glibc iostream?' \
	65	'fp->_pptr - fp->_pbase' \
	66	\
	67	'# emx+gcc' \
	68	'fp->_ptr - fp->_buffer' \
	69	\
	70	'# Minix' \
	71	'fp->_ptr - fp->_buf' \
	72	\
	73	'# Plan9' \
	74	'fp->wp - fp->buf' \
	75	\
	76	'# VMS' \
	77	'(fp)->_ptr - (fp)->_base' \
	78	\
	79	'# e.g., DGUX R4.11; the info is not available' \
	80	1 \
	81	; do
	82
	83	# Skip each embedded comment.
	84	case "$ac_expr" in '#'*) continue;; esac
	85
	86	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>]],
	87	[[FILE *fp = stdin; (void) ($ac_expr);]])],
	88	[fp_done=yes]
	89	)
	90	test "$fp_done" = yes && break
	91	done
	92
	93	ac_cv_sys_pending_output_n_bytes=$ac_expr
	94	]
	95	)
	96	AC_DEFINE_UNQUOTED([PENDING_OUTPUT_N_BYTES],
	97	$ac_cv_sys_pending_output_n_bytes,
	98	[the number of pending output bytes on stream 'fp'])
	99	])