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