in src/c/perf-map-agent.c [94:98]
void generate_single_entry(jvmtiEnv *jvmti, jmethodID method, const void *code_addr, jint code_size) {
char entry[100];
sig_string(jvmti, method, entry, sizeof(entry));
perf_map_write_entry(method_file, code_addr, code_size, entry);
}