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Comment by efficax | Hacker News Reader

rust binaries are statically linked, that's the big difference. If you included all the libc code statically in most c programs they'd probably also be pretty big

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Go programs are also statically linked and Go based CLI tools generally only come in at 3-4 MB IIRC. I've used static linking in binaries in Nim and C programs too with similar (or smaller) sizes.

Rust binaries are just impressively large. I'd guess part of it must be how Rust monomorphizes generics: https://rustc-dev-guide.rust-lang.org/backend/monomorph.html

if you strip them you tend to lose a lot of the fat.

Nice, any tips on how to do that? Is there a Cargo thing or just run regular ole strip?

https://github.com/johnthagen/min-sized-rust

strip will help to some extent, like 20% downsize, just not enough

when i have an embedded board with say 64mb storage,a few rust executable will fill them up fast. problem is that rust does not give me option to do dynamic link to its stdlib.

Not that this is based on some Googleing and experimentation; I could not find official docs.

It actually is possible to dynamically link to the standard library. Add this to your project's .cargo/config.toml file:

    [build]
    rustflags = ["-C", "prefer-dynamic"]

And add a reference to this crate, which copies the stdlib's shared library to your output directory:

https://github.com/WilliamVenner/prefer-dynamic

After you do `cargo build --release`, you will notice you hello world EXE is much smaller than a typical rust binary. Like 10~20KB small. On Windows it runs just fine. On Linux, I has to change the exe's RPATH to look for the standard library in the current directory:

    patchelf --set-rpath '$ORIGIN' ./exe_name

Anyways, it is possible. The rustc compiler itself is shipped in this way.

as far as i know,this is not officially supported.rust links to its stdlib statically by design. when you have to share this stdlib with a few dynamically linked rust crates it's hard to do in practice.

tried all size reduction tricks,still the size is much large,like 15x large than c,c++. even the stdlib is a 3x larger than to libstdc++

by default rust doesn't statically link to libc.

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