You can decompile the binary. … You won’t get the variable names unless it was a debug binary. You won’t get the exact same logic unless you compiled without optimizations.

Is it illegal to decompile code?

Decompiling is absolutely LEGAL, regardless of what the shills say. At most, you can be sued for unauthorized activity relating to software unless you’re redistributing it.

Can you decompile anything?

Decompilers exist that will restore shockingly accurate source code from the compiled code. Aside from some extra comments and spaces, the output is basically 1:1 with the original. Java and C# are similarly easy to decompile.