[Mesa-dev] [PATCH] configure.ac: Enable GLX_USE_TLS if possible.

[Zhigang Gong]

On Wed, Feb 08, 2012 at 02:46:42PM -0800, Eric Anholt wrote:
> On Wed,  8 Feb 2012 16:19:38 +0800, zhigang.gong at linux.intel.com wrote:
> > From: Zhigang Gong <zhigang.gong at linux.intel.com>
> > 
> > If the system support tls, we prefer to enable it by default
> > just as xserver does. Actually, the checking code is copied
> > from xserver/configure.ac.
> > 
> > Signed-off-by: Zhigang Gong <zhigang.gong at linux.intel.com>
> > ---
> >  configure.ac |   10 ++++++++--
> >  1 files changed, 8 insertions(+), 2 deletions(-)
> > 
> > diff --git a/configure.ac b/configure.ac
> > index b2b1ab8..7c2756b 100644
> > --- a/configure.ac
> > +++ b/configure.ac
> > @@ -1103,8 +1103,14 @@ dnl
> >  AC_ARG_ENABLE([glx-tls],
> >      [AS_HELP_STRING([--enable-glx-tls],
> >          [enable TLS support in GLX @<:@default=disabled@:>@])],
> > -    [GLX_USE_TLS="$enableval"],
> > -    [GLX_USE_TLS=no])
> > +    [GLX_USE_TLS=$enableval
> > +     if test "x$GLX_USE_TLS" = "xyes" && test "${ac_cv_tls}" = "none" ; then
> > +        AC_MSG_ERROR([GLX with TLS support requested, but the compiler does not support it.])
> > +     fi],
> > +    [GLX_USE_TLS=no
> > +     if test "${ac_cv_tls}" != "none" ; then
> > +        GLX_USE_TLS=yes
> > +     fi])
> >  AC_SUBST(GLX_TLS, ${GLX_USE_TLS})
> 
> I don't think you have anything setting ac_cv_tls.

You are right, I forgot to add the checking code which is also from xserver.
Sorry for that, here is the v2 patch:

From: Zhigang Gong <zhigang.gong at linux.intel.com>
Date: Wed, 8 Feb 2012 16:12:42 +0800
Subject: [PATCH v2] configure.ac: Enable GLX_USE_TLS if possible.

If the system support tls, we prefer to enable it by default
just as xserver does. Actually, the checking code is copied
from xserver/configure.ac.

Signed-off-by: Zhigang Gong <zhigang.gong at linux.intel.com>
---
 configure.ac |   39 +++++++++++++++++++++++++++++++++++++--
 1 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index b2b1ab8..3dfafba 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1099,12 +1099,47 @@ esac
 dnl
 dnl TLS detection
 dnl
+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="$CFLAGS"
+        CFLAGS="$CFLAGS $STRICT_CFLAGS"
+        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
+        mesa_tls=$ac_cv_tls' __attribute__((tls_model("initial-exec")))'
+    else
+        mesa_tls=$ac_cv_tls
+    fi
+
+    AC_DEFINE_UNQUOTED([TLS], $mesa_tls, [The compiler supported TLS storage class, prefering initial-exec if tls_model is supported])
+fi
 
 AC_ARG_ENABLE([glx-tls],
     [AS_HELP_STRING([--enable-glx-tls],
         [enable TLS support in GLX @<:@default=disabled@:>@])],
-    [GLX_USE_TLS="$enableval"],
-    [GLX_USE_TLS=no])
+    [GLX_USE_TLS=$enableval
+     if test "x$GLX_USE_TLS" = "xyes" && test "${ac_cv_tls}" = "none" ; then
+        AC_MSG_ERROR([GLX with TLS support requested, but the compiler does not support it.])
+     fi],
+    [GLX_USE_TLS=no
+     if test "${ac_cv_tls}" != "none" ; then
+        GLX_USE_TLS=yes
+     fi])
 AC_SUBST(GLX_TLS, ${GLX_USE_TLS})
 
 AS_IF([test "x$GLX_USE_TLS" = xyes],
-- 
1.7.4.4