m4/fpending.m4

   1 #serial 1
   2
   3 dnl From Jim Meyering
   4 dnl Using code from emacs, based on suggestions from Paul Eggert
   5 dnl and Ulrich Drepper.
   6
   7 AC_DEFUN(jm_FUNC_FPENDING,
   8 [
   9   AC_CHECK_HEADERS(stdio_ext.h)
  10   AC_FEPLACE_FUNCS([__fpending])
  11   if test $ac_cv_func___fpending = no; then
  12     AC_REPLACE_FUNCS(__fpending)
  13     AC_CACHE_CHECK(
  14               [how to determine the number of pending output bytes on a stream],
  15                    ac_cv_sys_pending_output_n_bytes,
  16       [
  17         fp_save_DEFS=$DEFS
  18         for ac_expr in                                          \
  19                                                                 \
  20           '# glibc2'                                            \
  21           'fp->_IO_write_ptr - fp->_IO_write_base'              \
  22                                                                 \
  23           '# traditional Unix'                                  \
  24           'fp->_ptr - fp->_base'                                \
  25                                                                 \
  26           '# BSD'                                               \
  27           'fp->_p - fp->_bf._base'                              \
  28                                                                 \
  29           '# SCO, Unixware'                                     \
  30           'fp->__ptr - fp->__base'                              \
  31                                                                 \
  32           '# old glibc?'                                        \
  33           'fp->__bufp - fp->__buffer'                           \
  34                                                                 \
  35           '# old glibc iostream?'                               \
  36           'fp->_pptr - fp->_pbase'                              \
  37                                                                 \
  38           '# VMS'                                               \
  39           '(*fp)->_ptr - (*fp)->_base'                          \
  40                                                                 \
  41           '# e.g., DGUX R4.11; the info is not available'       \
  42           1                                                     \
  43           ; do
  44             # Skip each embedded comment.
  45             case "$ac_expr" in '#'*) continue;; esac
  46 '
  47
  48             DEFS="$DEFS -DPENDING_OUTPUT_N_BYTES=$ac_expr"
  49             AC_TRY_COMPILE(
  50               [#include <stdio.h>
  51               ],
  52               [long unsigned int n = $ac_expr;],
  53               fp_done=yes
  54             )
  55             DEFS=$fp_save_DEFS
  56             test "$fp_done" = yes && break
  57         done
  58         AC_DEFINE_UNQUOTED(PENDING_OUTPUT_N_BYTES, $ac_expr,
  59           [the number of pending output bytes on stream `fp'])
  60       ])
  61   fi
  62
  63
  64
  65
  66   if test $fu_cv_sys_struct_timespec = yes; then
  67     AC_DEFINE_UNQUOTED(HAVE_STRUCT_TIMESPEC, 1,
  68                        [Define if struct timespec is declared in <time.h>. ])
  69   fi
  70 ])