getloadavg: Add comments about platforms.

[gnulib.git] / m4 / fpending.m4

diff --git a/m4/fpending.m4 b/m4/fpending.m4
index 6e28797..314e003 100644 (file)
--- a/m4/fpending.m4
+++ b/m4/fpending.m4
@@ -1,65 +1,83 @@
-#serial 1
+# serial 15
+
+# Copyright (C) 2000-2001, 2004-2011 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 From Jim Meyering
 dnl Using code from emacs, based on suggestions from Paul Eggert
 dnl and Ulrich Drepper.
 

-AC_DEFUN(jm_FUNC_FPENDING,
+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(stdio_ext.h)
-  AC_REPLACE_FUNCS([__fpending])
+  AC_CHECK_HEADERS_ONCE([stdio_ext.h])
+  AC_CHECK_FUNCS_ONCE([__fpending])
+  fp_headers='
+#     include <stdio.h>
+#     if HAVE_STDIO_EXT_H
+#      include <stdio_ext.h>
+#     endif
+'
+  AC_CHECK_DECLS([__fpending], , , $fp_headers)

   if test $ac_cv_func___fpending = no; then
     AC_CACHE_CHECK(
   if test $ac_cv_func___fpending = no; then
     AC_CACHE_CHECK(

-             [how to determine the number of pending output bytes on a stream],
-                  ac_cv_sys_pending_output_n_bytes,
+              [how to determine the number of pending output bytes on a stream],
+                   ac_cv_sys_pending_output_n_bytes,

       [
       [

-        fp_save_DEFS=$DEFS
-       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->__base'                            \
-                                                               \
-           '# old glibc?'                                      \
-           'fp->__bufp - fp->__buffer'                         \
-                                                               \
-           '# old glibc iostream?'                             \
-           'fp->_pptr - fp->_pbase'                            \
-                                                               \
-           '# VMS'                                             \
-           '(*fp)->_ptr - (*fp)->_base'                        \
-                                                               \
-           '# e.g., DGUX R4.11; the info is not available'     \
-           1                                                   \
-           ; do
+        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'                                      \
+                                                                          \
+            '# VMS'                                                       \
+            '(*fp)->_ptr - (*fp)->_base'                                  \
+                                                                          \
+            '# e.g., DGUX R4.11; the info is not available'               \
+            1                                                             \
+            ; do

 
 

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

 
 

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

 
 

-       ac_cv_sys_pending_output_n_bytes=$ac_expr
+        ac_cv_sys_pending_output_n_bytes=$ac_expr

       ]
     )
       ]
     )

-    AC_DEFINE_UNQUOTED(PENDING_OUTPUT_N_BYTES,
+    AC_DEFINE_UNQUOTED([PENDING_OUTPUT_N_BYTES],

       $ac_cv_sys_pending_output_n_bytes,
       [the number of pending output bytes on stream `fp'])
       $ac_cv_sys_pending_output_n_bytes,
       [the number of pending output bytes on stream `fp'])

+    AC_LIBOBJ([fpending])

   fi
 ])
   fi
 ])