| 1 | # =========================================================================== |
| 2 | # http://www.gnu.org/software/autoconf-archive/ax_tls.html |
| 3 | # =========================================================================== |
| 4 | # |
| 5 | # SYNOPSIS |
| 6 | # |
| 7 | # AX_TLS([action-if-found], [action-if-not-found]) |
| 8 | # |
| 9 | # DESCRIPTION |
| 10 | # |
| 11 | # Provides a test for the compiler support of thread local storage (TLS) |
| 12 | # extensions. Defines TLS if it is found. Currently knows about GCC/ICC |
| 13 | # and MSVC. I think SunPro uses the same as GCC, and Borland apparently |
| 14 | # supports either. |
| 15 | # |
| 16 | # LICENSE |
| 17 | # |
| 18 | # Copyright (c) 2008 Alan Woodland <ajw05@aber.ac.uk> |
| 19 | # Copyright (c) 2010 Diego Elio Petteno` <flameeyes@gmail.com> |
| 20 | # |
| 21 | # This program is free software: you can redistribute it and/or modify it |
| 22 | # under the terms of the GNU General Public License as published by the |
| 23 | # Free Software Foundation, either version 3 of the License, or (at your |
| 24 | # option) any later version. |
| 25 | # |
| 26 | # This program is distributed in the hope that it will be useful, but |
| 27 | # WITHOUT ANY WARRANTY; without even the implied warranty of |
| 28 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General |
| 29 | # Public License for more details. |
| 30 | # |
| 31 | # You should have received a copy of the GNU General Public License along |
| 32 | # with this program. If not, see <http://www.gnu.org/licenses/>. |
| 33 | # |
| 34 | # As a special exception, the respective Autoconf Macro's copyright owner |
| 35 | # gives unlimited permission to copy, distribute and modify the configure |
| 36 | # scripts that are the output of Autoconf when processing the Macro. You |
| 37 | # need not follow the terms of the GNU General Public License when using |
| 38 | # or distributing such scripts, even though portions of the text of the |
| 39 | # Macro appear in them. The GNU General Public License (GPL) does govern |
| 40 | # all other use of the material that constitutes the Autoconf Macro. |
| 41 | # |
| 42 | # This special exception to the GPL applies to versions of the Autoconf |
| 43 | # Macro released by the Autoconf Archive. When you make and distribute a |
| 44 | # modified version of the Autoconf Macro, you may extend this special |
| 45 | # exception to the GPL to apply to your modified version as well. |
| 46 | |
| 47 | #serial 11 |
| 48 | |
| 49 | # Define m4_ifblank and m4_ifnblank macros from introduced in |
| 50 | # autotools 2.64 m4sugar.m4 if using an earlier autotools. |
| 51 | |
| 52 | ifdef([m4_ifblank], [], [ |
| 53 | m4_define([m4_ifblank], |
| 54 | [m4_if(m4_translit([[$1]], [ ][ ][ |
| 55 | ]), [], [$2], [$3])]) |
| 56 | ]) |
| 57 | |
| 58 | |
| 59 | ifdef([m4_ifnblank], [], [ |
| 60 | m4_define([m4_ifnblank], |
| 61 | [m4_if(m4_translit([[$1]], [ ][ ][ |
| 62 | ]), [], [$3], [$2])]) |
| 63 | ]) |
| 64 | |
| 65 | AC_DEFUN([AX_TLS], [ |
| 66 | AC_MSG_CHECKING(for thread local storage (TLS) class) |
| 67 | AC_CACHE_VAL(ac_cv_tls, [ |
| 68 | ax_tls_keywords="__thread __declspec(thread) none" |
| 69 | for ax_tls_keyword in $ax_tls_keywords; do |
| 70 | AS_CASE([$ax_tls_keyword], |
| 71 | [none], [ac_cv_tls=none ; break], |
| 72 | [AC_TRY_LINK( |
| 73 | [$ax_tls_keyword int foo;], |
| 74 | [++foo;], |
| 75 | [ac_cv_tls=$ax_tls_keyword ; break], |
| 76 | [ac_cv_tls=none] |
| 77 | )]) |
| 78 | done |
| 79 | ]) |
| 80 | AC_MSG_RESULT($ac_cv_tls) |
| 81 | |
| 82 | AS_IF([test "$ac_cv_tls" != "none"], |
| 83 | AC_DEFINE_UNQUOTED([TLS], $ac_cv_tls, [If the compiler supports a TLS storage class define it to that here]) |
| 84 | m4_ifnblank([$1], [$1]), |
| 85 | m4_ifnblank([$2], [$2]) |
| 86 | ) |
| 87 | ]) |