Imported Upstream version 1.3.14

[debian/gzip] / m4 / fpending.m4

diff --git a/m4/fpending.m4 b/m4/fpending.m4
new file mode 100644 (file)
index 0000000..fecf3f3
--- /dev/null
+++ b/m4/fpending.m4
@@ -0,0 +1,83 @@
+# serial 15
+
+# Copyright (C) 2000-2001, 2004-2009 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_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
+
+         # Skip each embedded comment.
+         case "$ac_expr" in '#'*) continue;; esac
+
+         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'])
+    AC_LIBOBJ([fpending])
+  fi
+])