glx: Silence warnings when building with clang

This replaces AX_TLS (GPL3) with XORG_TLS (MIT)

In file included from glapi.c:46:
In file included from ./glapi.h:51:
./glthread.h:237:20: error: unknown attribute 'tls_model' ignored [-Werror,-Wunknown-attributes]
    __attribute__((tls_model("initial-exec")));
                   ^
In file included from glapi.c:46:
./glapi.h:92:20: error: unknown attribute 'tls_model' ignored [-Werror,-Wunknown-attributes]
    __attribute__((tls_model("initial-exec")));
                   ^
glapi.c:82:20: error: unknown attribute 'tls_model' ignored [-Werror,-Wunknown-attributes]
    __attribute__((tls_model("initial-exec"))) = NULL;
                   ^
glapi.c:85:20: error: unknown attribute 'tls_model' ignored [-Werror,-Wunknown-attributes]
    __attribute__((tls_model("initial-exec")));
                   ^
4 errors generated.
Signed-off-by: Jeremy Huddleston <jeremyhu@apple.com>
Tested-by: Jamey Sharp <jamey@minilop.net>
Acked-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

configure.ac

@@ -587,7 +587,7 @@ dnl GLX build options
 AC_ARG_ENABLE(aiglx,          AS_HELP_STRING([--enable-aiglx], [Build accelerated indirect GLX (default: enabled)]),
                                 [AIGLX=$enableval],
                                 [AIGLX=yes])
-AX_TLS
+XORG_TLS
 AC_ARG_ENABLE(glx-tls,        AS_HELP_STRING([--enable-glx-tls], [Build GLX with TLS support (default: auto)]),
                                 [GLX_USE_TLS=$enableval
                                  if test "x$GLX_USE_TLS" = "xyes" && test "${ac_cv_tls}" = "none" ; then

glx/glapi.c

@@ -78,11 +78,9 @@ static void init_glapi_relocs(void);
 /*@{*/
 #if defined(GLX_USE_TLS)
 
-PUBLIC TLS struct _glapi_table * _glapi_tls_Dispatch
-    __attribute__((tls_model("initial-exec"))) = NULL;
+PUBLIC TLS struct _glapi_table * _glapi_tls_Dispatch = NULL;
 
-PUBLIC TLS void * _glapi_tls_Context
-    __attribute__((tls_model("initial-exec")));
+PUBLIC TLS void * _glapi_tls_Context;
 
 PUBLIC const struct _glapi_table *_glapi_Dispatch = NULL;
 PUBLIC const void *_glapi_Context = NULL;

glx/glapi.h

@@ -83,8 +83,7 @@ typedef void (*_glapi_warning_func)(void *ctx, const char *str, ...);
 const extern void *_glapi_Context;
 const extern struct _glapi_table *_glapi_Dispatch;
 
-extern TLS void * _glapi_tls_Context
-    __attribute__((tls_model("initial-exec")));
+extern TLS void * _glapi_tls_Context;
 
 # define GET_CURRENT_CONTEXT(C)  GLcontext *C = (GLcontext *) _glapi_tls_Context
 

glx/glthread.h

@@ -233,8 +233,7 @@ _glthread_SetTSD(_glthread_TSD *, void *);
 
 #if defined(GLX_USE_TLS)
 
-extern TLS struct _glapi_table * _glapi_tls_Dispatch
-    __attribute__((tls_model("initial-exec")));
+extern TLS struct _glapi_table * _glapi_tls_Dispatch;
 
 #define GET_DISPATCH() _glapi_tls_Dispatch
 

include/dix-config.h.in

@@ -447,7 +447,7 @@
 /* Define to 1 if you have the `ffs' function. */
 #undef HAVE_FFS
 
-/* If the compiler supports a TLS storage class define it to that here */
+/* The compiler supported TLS storage class, prefering initial-exec if tls_model is supported */
 #undef TLS
 
 /* Correctly set _XSERVER64 for OSX fat binaries */

m4/ax_tls.m4

-# ===========================================================================
-#             http://www.nongnu.org/autoconf-archive/ax_tls.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_TLS
-#
-# DESCRIPTION
-#
-#   Provides a test for the compiler support of thread local storage (TLS)
-#   extensions. Defines TLS if it is found. Currently only knows about GCC
-#   and MSVC. I think SunPro uses the same as GCC, and Borland apparently
-#   supports either.
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Alan Woodland <ajw05@aber.ac.uk>
-#
-#   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.
-
-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
-       case $ax_tls_keyword in
-          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
-             )
-       esac
-    done
-])
-
-  if test "$ac_cv_tls" != "none"; then
-    dnl AC_DEFINE([TLS], [], [If the compiler supports a TLS storage class define it to that here])
-    AC_DEFINE_UNQUOTED([TLS], $ac_cv_tls, [If the compiler supports a TLS storage class define it to that here])
-  fi
-  AC_MSG_RESULT($ac_cv_tls)
-])

m4/xorg-tls.m4

+dnl Copyright © 2011 Apple Inc.
+dnl
+dnl Permission is hereby granted, free of charge, to any person obtaining a
+dnl copy of this software and associated documentation files (the "Software"),
+dnl to deal in the Software without restriction, including without limitation
+dnl the rights to use, copy, modify, merge, publish, distribute, sublicense,
+dnl and/or sell copies of the Software, and to permit persons to whom the
+dnl Software is furnished to do so, subject to the following conditions:
+dnl
+dnl The above copyright notice and this permission notice (including the next
+dnl paragraph) shall be included in all copies or substantial portions of the
+dnl Software.
+dnl
+dnl THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+dnl IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+dnl FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+dnl THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+dnl LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+dnl FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+dnl DEALINGS IN THE SOFTWARE.
+dnl
+dnl Authors: Jeremy Huddleston <jeremyhu@apple.com>
+
+AC_DEFUN([XORG_TLS], [
+    AC_MSG_CHECKING(for thread local storage (TLS) support)
+    AC_CACHE_VAL(ac_cv_tls, [
+        ac_cv_tls=none
+        keywords="__thread __declspec(thread)"
+        for kw in $keywords ; do
+            AC_TRY_COMPILE([int $kw test;], [], ac_cv_tls=$kw)
+        done
+    ])
+    AC_MSG_RESULT($ac_cv_tls)
+
+    if test "$ac_cv_tls" != "none"; then
+        AC_MSG_CHECKING(for tls_model attribute support)
+        AC_CACHE_VAL(ac_cv_tls_model, [
+            save_CFLAGS="$CFLAGS"
+            dnl -Werror causes clang's default -Wunknown-attributes to become an error
+            dnl We can't use -Werror=unknown-attributes because gcc doesn't understand it
+            dnl -Werror=attributes is for gcc, clang seems to ignore it
+            CFLAGS="$CFLAGS -Werror -Werror=attributes"
+            AC_TRY_COMPILE([int $ac_cv_tls __attribute__((tls_model("initial-exec"))) test;], [],
+                           ac_cv_tls_model=yes, ac_cv_tls_model=no)
+            CFLAGS="$save_CFLAGS"
+        ])
+        AC_MSG_RESULT($ac_cv_tls_model)
+
+        if test "x$ac_cv_tls_model" = "xyes" ; then
+            xorg_tls=$ac_cv_tls' __attribute__((tls_model("initial-exec")))'
+        else
+            xorg_tls=$ac_cv_tls
+        fi
+
+        AC_DEFINE_UNQUOTED([TLS], $xorg_tls, [The compiler supported TLS storage class, prefering initial-exec if tls_model is supported])
+    fi
+])