m4/xorg-tls.m4

   1 dnl Copyright © 2011 Apple Inc.
   2 dnl
   3 dnl Permission is hereby granted, free of charge, to any person obtaining a
   4 dnl copy of this software and associated documentation files (the "Software"),
   5 dnl to deal in the Software without restriction, including without limitation
   6 dnl the rights to use, copy, modify, merge, publish, distribute, sublicense,
   7 dnl and/or sell copies of the Software, and to permit persons to whom the
   8 dnl Software is furnished to do so, subject to the following conditions:
   9 dnl
  10 dnl The above copyright notice and this permission notice (including the next
  11 dnl paragraph) shall be included in all copies or substantial portions of the
  12 dnl Software.
  13 dnl
  14 dnl THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15 dnl IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16 dnl FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17 dnl THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18 dnl LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  19 dnl FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  20 dnl DEALINGS IN THE SOFTWARE.
  21 dnl
  22 dnl Authors: Jeremy Huddleston <jeremyhu@apple.com>
  23
  24 AC_DEFUN([XORG_TLS], [
  25     AC_REQUIRE([XORG_STRICT_OPTION])
  26     AC_MSG_CHECKING(for thread local storage (TLS) support)
  27     AC_CACHE_VAL(ac_cv_tls, [
  28         ac_cv_tls=none
  29         keywords="__thread __declspec(thread)"
  30         for kw in $keywords ; do
  31             AC_TRY_COMPILE([int $kw test;], [], ac_cv_tls=$kw ; break ;)
  32         done
  33     ])
  34     AC_MSG_RESULT($ac_cv_tls)
  35
  36     if test "$ac_cv_tls" != "none"; then
  37         AC_MSG_CHECKING(for tls_model attribute support)
  38         AC_CACHE_VAL(ac_cv_tls_model, [
  39             save_CFLAGS="$CFLAGS"
  40             CFLAGS="$CFLAGS $STRICT_CFLAGS"
  41             AC_TRY_COMPILE([int $ac_cv_tls __attribute__((tls_model("initial-exec"))) test;], [],
  42                            ac_cv_tls_model=yes, ac_cv_tls_model=no)
  43             CFLAGS="$save_CFLAGS"
  44         ])
  45         AC_MSG_RESULT($ac_cv_tls_model)
  46
  47         if test "x$ac_cv_tls_model" = "xyes" ; then
  48             xorg_tls=$ac_cv_tls' __attribute__((tls_model("initial-exec")))'
  49         else
  50             xorg_tls=$ac_cv_tls
  51         fi
  52
  53         AC_DEFINE_UNQUOTED([TLS], $xorg_tls, [The compiler supported TLS storage class, prefering initial-exec if tls_model is supported])
  54     fi
  55 ])