Minimum Rust Binary Size
Author: Alyssa Riceman
Posted:
Consider this very simple Rust program:
main() {
()
}
When compiled into a Windows executable in debug mode (target: x86_64-pc-windows-msvc), the resulting file is 135 KB. In release mode, 132 KB.
When compiled into a Linux binary in debug mode (target: x86_64-unknown-linux-gnu), the resulting file is 3.4 MB. In release mode, 3.3 MB.
When compiled into a Mac binary in debug mode (target: x86_64-apple-darwin), the resulting file size is 419 KB. In release mode, 414 KB.
I wish I knew enough about reading binaries to be able to get anything useful out of those files in a hex editor, because those file sizes, and especially the differences between them, are interesting. What’s all this machine code being run in order to start a program and immediately exit without doing anything? What are the differences between the systems (or between the compilers for the systems) which lead to such dramatic disparities in how much such code is run in order to do that? I don’t know, and I lack the skills necessary to find out, but I predict that the curiosity is going to keep gnawing at me now that I’ve discovered this.