fpending: fix regression on DragonFly BSD

[gnulib.git] / m4 / fpending.m4

diff --git a/m4/fpending.m4 b/m4/fpending.m4
index fecf3f3..669105b 100644 (file)
--- a/m4/fpending.m4
+++ b/m4/fpending.m4
@@ -1,6 +1,6 @@
-# serial 15
+# serial 21
 
-# Copyright (C) 2000-2001, 2004-2009 Free Software Foundation, Inc.
+# Copyright (C) 2000-2001, 2004-2013 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.
@@ -16,68 +16,84 @@ dnl we have to grub around in the FILE struct.
 AC_DEFUN([gl_FUNC_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(
-             [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'                                      \
-                                                                         \
-           '# VMS'                                                       \
-           '(*fp)->_ptr - (*fp)->_base'                                  \
-                                                                         \
-           '# e.g., DGUX R4.11; the info is not available'               \
-           1                                                             \
-           ; do
+    #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
+])
 
-         # Skip each embedded comment.
-         case "$ac_expr" in '#'*) continue;; esac
+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
 
-         AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>]],
-           [[FILE *fp = stdin; (void) ($ac_expr);]])],
-           [fp_done=yes]
-         )
-         test "$fp_done" = yes && break
-       done
+        # Skip each embedded comment.
+        case "$ac_expr" in '#'*) continue;; esac
 
-       ac_cv_sys_pending_output_n_bytes=$ac_expr
-      ]
-    )
-    AC_DEFINE_UNQUOTED([PENDING_OUTPUT_N_BYTES],
-      $ac_cv_sys_pending_output_n_bytes,
-      [the number of pending output bytes on stream `fp'])
-    AC_LIBOBJ([fpending])
-  fi
+        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>]],
+          [[FILE *fp = stdin; (void) ($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'])
 ])