+2009-05-12 Bruno Haible <bruno@clisp.org>
+
+ * m4/mmap-anon.m4 (gl_FUNC_MMAP_ANON): Add comments.
+
2009-05-12 Jim Meyering <meyering@redhat.com>
* top/maint.mk: Adjust backslash alignment.
-# mmap-anon.m4 serial 5
+# mmap-anon.m4 serial 6
dnl Copyright (C) 2005, 2007, 2009 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
+# Detect how mmap can be used to create anonymous (not file-backed) memory
+# mappings.
+# - On Linux, AIX, OSF/1, Solaris, Cygwin, Interix, Haiku, both MAP_ANONYMOUS
+# and MAP_ANON exist and have the same value.
+# - On HP-UX, only MAP_ANONYMOUS exists.
+# - On MacOS X, FreeBSD, NetBSD, OpenBSD, only MAP_ANON exists.
+# - On IRIX, neither exists, and a file descriptor opened to /dev/zero must be
+# used.
+
AC_DEFUN([gl_FUNC_MMAP_ANON],
[
dnl Work around a bug of AC_EGREP_CPP in autoconf-2.57.