Rustc bug: rust-lang/rust#132900
python3 gen_code.py 4097
RUSTFLAGS="-g" cargo build --release
While if the number is less than 4097, it will work fine.
python3 gen_code.py 4096
RUSTFLAGS="-g" cargo build --release
A function with 4097 lines of code will cause a panic when the macro is expanded.