diff options
Diffstat (limited to 'm4/fr_tls.m4')
| -rw-r--r-- | m4/fr_tls.m4 | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/m4/fr_tls.m4 b/m4/fr_tls.m4 new file mode 100644 index 0000000..56ad7f2 --- /dev/null +++ b/m4/fr_tls.m4 @@ -0,0 +1,67 @@ +dnl # +dnl # Figure out which storage class specifier for Thread Local Storage is supported by the compiler +dnl # +AC_DEFUN([FR_TLS], +[ +dnl # +dnl # See if the compilation works with __thread, for thread-local storage +dnl # + AC_MSG_CHECKING(for __thread support in compiler) + AC_RUN_IFELSE( + [AC_LANG_SOURCE( + [[ + static __thread int val; + int main(int argc, char **argv) { + val = 0; + return val; + } + ]]) + ],[have_tls=yes],[have_tls=no],[have_tls=no]) + AC_MSG_RESULT($have_tls) + if test "x$have_tls" = "xyes"; then + AC_DEFINE([TLS_STORAGE_CLASS],[__thread],[Define if the compiler supports a thread local storage class]) + fi + +dnl # +dnl # __declspec(thread) does exactly the same thing as __thread, but is supported by MSVS +dnl # + if test "x$have_tls" = "xno"; then + AC_MSG_CHECKING(for __declspec(thread) support in compiler) + AC_RUN_IFELSE( + [AC_LANG_SOURCE( + [[ + static _Thread_local int val; + int main(int argc, char **argv) { + val = 0; + return val; + } + ]]) + ],[have_tls=yes],[have_tls=no],[have_tls=no]) + AC_MSG_RESULT($have_tls) + if test "x$have_tls" = "xyes"; then + AC_DEFINE([TLS_STORAGE_CLASS],[__declspec(thread)],[Define if the compiler supports a thread local storage class]) + fi + fi +dnl # +dnl # _Thread_local does exactly the same thing as __thread, but it's standards compliant with C11. +dnl # we, however, state we are only compliant with C99, so the compiler will probably emit warnings +dnl # if we use it. So save it as a last resort. +dnl # + if test "x$have_tls" = "xno"; then + AC_MSG_CHECKING(for _Thread_local support in compiler) + AC_RUN_IFELSE( + [AC_LANG_SOURCE( + [[ + static _Thread_local int val; + int main(int argc, char **argv) { + val = 0; + return val; + } + ]]) + ],[have_tls=yes],[have_tls=no],[have_tls=no]) + AC_MSG_RESULT($have_tls) + if test "x$have_tls" = "xyes"; then + AC_DEFINE([TLS_STORAGE_CLASS],[_Thread_local],[Define if the compiler supports a thread local storage class]) + fi + fi +]) |