From 08300ab7405f7b23ae453b920d3c0730ae6fc633 Mon Sep 17 00:00:00 2001
From: Christian Thaeter <ct@pipapo.org>
Date: Sun, 20 Dec 2009 20:16:43 +0100
Subject: [PATCH] fix and use the mmap-anon.m4 macro for our purpose (untested)

---
 configure.ac    |  1 +
 m4/mmap-anon.m4 | 29 ++++++++++++-----------------
 2 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/configure.ac b/configure.ac
index c692e4c..2b070b7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -32,6 +32,7 @@ ACX_PTHREAD
 AM_CONDITIONAL([HAVE_THREADING], [test x"$acx_pthread_ok" = xyes])
 AC_CHECK_HEADER([execinfo.h], AC_DEFINE(HAVE_EXECINFO_H))
 
+nobug_FUNC_MMAP_ANON
 
 #
 # Need to check for pkg-config, otherwise the next line doesn't work.
diff --git a/m4/mmap-anon.m4 b/m4/mmap-anon.m4
index 14b6270..8a4ef92 100644
--- a/m4/mmap-anon.m4
+++ b/m4/mmap-anon.m4
@@ -1,4 +1,6 @@
 # mmap-anon.m4 serial 8
+dnl Copyright (C) 2009 Christian Thaeter <ct@pipapo.org>
+dnl parts are borrowed from gnulib:
 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,
@@ -13,23 +15,17 @@ dnl with or without modifications, as long as this notice is preserved.
 # - On IRIX, neither exists, and a file descriptor opened to /dev/zero must be
 #   used.
 
-AC_DEFUN([gl_FUNC_MMAP_ANON],
+AC_DEFUN([nobug_FUNC_MMAP_ANON],
 [
   dnl Work around a bug of AC_EGREP_CPP in autoconf-2.57.
   AC_REQUIRE([AC_PROG_CPP])
   AC_REQUIRE([AC_PROG_EGREP])
 
-  dnl Persuade glibc <sys/mman.h> to define MAP_ANONYMOUS.
-  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
-
-  # Check for mmap(). Don't use AC_FUNC_MMAP, because it checks too much: it
-  # fails on HP-UX 11, because MAP_FIXED mappings do not work. But this is
-  # irrelevant for anonymous mappings.
-  AC_CHECK_FUNC([mmap], [gl_have_mmap=yes], [gl_have_mmap=no])
+  AC_FUNC_MMAP
 
   # Try to allow MAP_ANONYMOUS.
-  gl_have_mmap_anonymous=no
-  if test $gl_have_mmap = yes; then
+  nobug_have_mmap_anonymous=no
+  if test $ac_cv_func_mmap = yes; then
     AC_MSG_CHECKING([for MAP_ANONYMOUS])
     AC_EGREP_CPP([I cant identify this map.], [
 #include <sys/mman.h>
@@ -37,8 +33,8 @@ AC_DEFUN([gl_FUNC_MMAP_ANON],
     I cant identify this map.
 #endif
 ],
-      [gl_have_mmap_anonymous=yes])
-    if test $gl_have_mmap_anonymous != yes; then
+      [nobug_have_mmap_anonymous=yes])
+    if test $nobug_have_mmap_anonymous != yes; then
       AC_EGREP_CPP([I cant identify this map.], [
 #include <sys/mman.h>
 #ifdef MAP_ANON
@@ -47,13 +43,12 @@ AC_DEFUN([gl_FUNC_MMAP_ANON],
 ],
         [AC_DEFINE([MAP_ANONYMOUS], [MAP_ANON],
           [Define to a substitute value for mmap()'s MAP_ANONYMOUS flag.])
-         gl_have_mmap_anonymous=yes])
+         nobug_have_mmap_anonymous=yes])
     fi
-    AC_MSG_RESULT([$gl_have_mmap_anonymous])
-    if test $gl_have_mmap_anonymous = yes; then
+    AC_MSG_RESULT([$nobug_have_mmap_anonymous])
+    if test $nobug_have_mmap_anonymous = yes; then
       AC_DEFINE([HAVE_MAP_ANONYMOUS], [1],
-        [Define to 1 if mmap()'s MAP_ANONYMOUS flag is available after including
-         config.h and <sys/mman.h>.])
+        [Define to 1 if mmap()'s MAP_ANONYMOUS flag is available.])
     fi
   fi
 ])
-- 
2.11.4.GIT