comma_fprintf
printed += comma_fprintf(fp, &first, "%s", field->name);
return comma_fprintf(fp, (bool *)priv, " %s: %s", name, val);
printed += comma_fprintf(fp, &first, " %s=%" PRIu64,
printed += comma_fprintf(fp, &first, " (not a tracepoint)");
printed += comma_fprintf(fp, &first, " (no trace field)");
printed += comma_fprintf(fp, &first, " trace_fields: %s", field->name);