* new gnulib m4 macros

1 files changed, 79 insertions, 0 deletions

diff --git a/m4/fpending.m4 b/m4/fpending.m4
new file mode 100644
index 0000000..87398b1
--- /dev/null
+++ b/m4/fpending.m4
@@ -0,0 +1,79 @@
+#serial 6
+
+# Copyright (C) 2000, 2001, 2004, 2005 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_LIBSOURCES([__fpending.c, __fpending.h])
+
+  AC_CHECK_HEADERS(stdio_ext.h)
+  AC_REPLACE_FUNCS([__fpending])
+  fp_headers='
+#     if HAVE_STDIO_EXT_H
+#      include <stdio_ext.h>
+#     endif
+'
+  AC_CHECK_DECLS([__fpending], , , $fp_headers)
+  if test $ac_cv_func___fpending = no; then
+    AC_CACHE_CHECK(
+	      [how to determine the number of pending output bytes on a stream],
+		   ac_cv_sys_pending_output_n_bytes,
+      [
+	for ac_expr in						\
+								\
+	    '# glibc2'						\
+	    'fp->_IO_write_ptr - fp->_IO_write_base'		\
+								\
+	    '# traditional Unix'				\
+	    'fp->_ptr - fp->_base'				\
+								\
+	    '# BSD'						\
+	    'fp->_p - fp->_bf._base'				\
+								\
+	    '# SCO, Unixware'					\
+	    'fp->__ptr - fp->__base'				\
+								\
+	    '# old glibc?'					\
+	    'fp->__bufp - fp->__buffer'				\
+								\
+	    '# old glibc iostream?'				\
+	    'fp->_pptr - fp->_pbase'				\
+								\
+	    '# VMS'						\
+	    '(*fp)->_ptr - (*fp)->_base'			\
+								\
+	    '# e.g., DGUX R4.11; the info is not available'	\
+	    1							\
+	    ; do
+
+	  # Skip each embedded comment.
+	  case "$ac_expr" in '#'*) continue;; esac
+
+	  AC_TRY_COMPILE(
+	    [#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'])
+  fi
+])