string_sprintf_trc(fmt, US __FUNCTION__, __LINE__, __VA_ARGS__)
extern uschar *string_sprintf_trc(const char *, const uschar *, unsigned, ...) ALMOST_PRINTF(1,4);
string_sprintf_trc(fmt, US __FUNCTION__, __LINE__, __VA_ARGS__)
extern uschar *string_sprintf_trc(const char *, const uschar *, unsigned, ...) ALMOST_PRINTF(1,4);