build: use AX_TLS macro to detect whether __thread is supported

Definition of AX_TLS comes from the autoconf-archive project
(http://www.gnu.org/software/autoconf-archive/) to detect the feature.

Signed-off-by: Filipe Brandenburger <[email protected]>

configure.ac

@@ -14,6 +14,8 @@ LT_INIT
 
 AC_PROG_CC
 
+AX_TLS
+
 AC_CONFIG_FILES([Makefile])
 
 AC_OUTPUT

libnuma.c

@@ -31,6 +31,7 @@
 #include <sys/mman.h>
 #include <limits.h>
 
+#include "config.h"
 #include "numa.h"
 #include "numaif.h"
 #include "numaint.h"
@@ -61,8 +62,9 @@ struct bitmask **node_cpu_mask_v2;
 
 WEAK void numa_error(char *where);
 
-#ifdef __thread
+#ifndef TLS
 #warning "not threadsafe"
+#define __thread
 #endif
 
 static __thread int bind_policy = MPOL_BIND; 

m4/ax_tls.m4

@@ -0,0 +1,76 @@
+# ===========================================================================
+#          http://www.gnu.org/software/autoconf-archive/ax_tls.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_TLS([action-if-found], [action-if-not-found])
+#
+# DESCRIPTION
+#
+#   Provides a test for the compiler support of thread local storage (TLS)
+#   extensions. Defines TLS if it is found. Currently knows about GCC/ICC
+#   and MSVC. I think SunPro uses the same as GCC, and Borland apparently
+#   supports either.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Alan Woodland <[email protected]>
+#   Copyright (c) 2010 Diego Elio Petteno` <[email protected]>
+#
+#   This program is free software: you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 10
+
+AC_DEFUN([AX_TLS], [
+  AC_MSG_CHECKING(for thread local storage (TLS) class)
+  AC_CACHE_VAL(ac_cv_tls, [
+    ax_tls_keywords="__thread __declspec(thread) none"
+    for ax_tls_keyword in $ax_tls_keywords; do
+       AS_CASE([$ax_tls_keyword],
+          [none], [ac_cv_tls=none ; break],
+          [AC_TRY_COMPILE(
+              [#include <stdlib.h>
+               static void
+               foo(void) {
+               static ] $ax_tls_keyword [ int bar;
+               exit(1);
+               }],
+               [],
+               [ac_cv_tls=$ax_tls_keyword ; break],
+               ac_cv_tls=none
+           )])
+    done
+  ])
+  AC_MSG_RESULT($ac_cv_tls)
+
+  AS_IF([test "$ac_cv_tls" != "none"],
+    AC_DEFINE_UNQUOTED([TLS], $ac_cv_tls, [If the compiler supports a TLS storage class define it to that here])
+      m4_ifnblank([$1], [$1]),
+    m4_ifnblank([$2], [$2])
+  )
+])