Add an autoconf test to test whether the .section .gnu<warning>
works with the linker on the system, and define _warn_references
to nothing if not.
diff --git a/configure.in b/configure.in
index 5b2eea3..387b422 100644
--- a/configure.in
+++ b/configure.in
@@ -37,6 +37,24 @@
AC_FUNC_REALLOC
AC_CHECK_FUNCS(strcasecmp strdup strndup strerror snprintf vsnprintf vasprintf open vsyslog strncasecmp)
+#check if .section.gnu.warning accepts long strings (for __warn_references)
+AC_LANG_PUSH([C])
+
+AC_MSG_CHECKING([if .gnu.warning accepts long strings])
+AC_LINK_IFELSE([[
+extern void json_object_get();
+__asm__(".section .gnu.json_object_get,\n\t.ascii \"Please link against libjson-c instead of libjson\"\n\t.text");
+
+int main(int c,char* v) {return 0;}
+]], [
+ AC_DEFINE(HAS_GNU_WARNING_LONG, 1, [Define if .gnu.warning accepts long strings.])
+ AC_MSG_RESULT(yes)
+], [
+ AC_MSG_RESULT(no)
+])
+
+AC_LANG_POP([C])
+
AM_PROG_LIBTOOL
AC_CONFIG_FILES([