Decompiling a .so file depends heavily on what language it was compiled from: Decompiler Explorer
Technical highlights
Because the decompiler can’t infer types. undefined8 means "8 unknown bytes" – often a pointer or long long . Lib.so Decompiler Online
undefined8 Java_com_example_app_MainActivity_stringFromJNI(undefined8 param_1, undefined8 param_2) return "Hello from C++"; Decompiling a