22 lines
917 B
Plaintext
22 lines
917 B
Plaintext
dnl Check whether the target supports TLS.
|
|
AC_DEFUN([GCC_CHECK_TLS], [
|
|
GCC_ENABLE(tls, yes, [], [Use thread-local storage])
|
|
AC_CACHE_CHECK([whether the target supports thread-local storage],
|
|
have_tls, [
|
|
AC_RUN_IFELSE([__thread int a; int b; int main() { return a = b; }],
|
|
[dnl If the test case passed with dynamic linking, try again with
|
|
dnl static linking. This fails at least with some older Red Hat
|
|
dnl releases.
|
|
save_LDFLAGS="$LDFLAGS"
|
|
LDFLAGS="-static $LDFLAGS"
|
|
AC_RUN_IFELSE([__thread int a; int b; int main() { return a = b; }],
|
|
[have_tls=yes], [have_tls=no], [])
|
|
LDFLAGS="$save_LDFLAGS"],
|
|
[have_tls=no],
|
|
[AC_COMPILE_IFELSE([__thread int foo;], [have_tls=yes], [have_tls=no])]
|
|
)])
|
|
if test "$enable_tls $have_tls" = "yes yes"; then
|
|
AC_DEFINE(HAVE_TLS, 1,
|
|
[Define to 1 if the target supports thread-local storage.])
|
|
fi])
|