+/* Expands to a string that looks like "<file>:<line>", e.g. "tmp.c:10".
+ *
+ * See http://c-faq.com/ansi/stringize.html for an explanation of STRINGIZE and
+ * STRINGIZE2. */
+#define SOURCE_LOCATOR __FILE__ ":" STRINGIZE(__LINE__)
+#define STRINGIZE(ARG) STRINGIZE2(ARG)
+#define STRINGIZE2(ARG) #ARG
+