README: add multi-lib instructions

[coloredstderr/coloredstderr.git] / configure.ac

diff --git a/configure.ac b/configure.ac
index e8d66a4ad52dbdae367b83486b7265155b4c9832..edb692de80a357619c0468e31101fd49da738919 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -46,6 +46,7 @@ AC_TYPE_SSIZE_T
 
 AC_C_INLINE
 AX_C___ATTRIBUTE__
+AX_TLS
 
 AC_CHECK_MEMBER([struct _IO_FILE._fileno],
                 [AC_DEFINE([HAVE_STRUCT__IO_FILE__FILENO], 1,
@@ -91,3 +92,8 @@ AM_CONDITIONAL([HAVE_VFORK],[test "x$ac_cv_func_vfork_works" = xyes])
 
 AC_CONFIG_FILES([Makefile src/Makefile tests/Makefile])
 AC_OUTPUT
+
+if test x"$ac_cv_tls" = x"none"; then
+    AC_MSG_WARN([thread-local storage not supported by compiler, \
+possible race condition in threaded programs])
+fi