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250K for hello world example... where is this world going to! :) I am sure it can be trimmed, but we are getting oblivious to common sense a little. This is sy

250K for hello world example... where is this world going to! :) I am sure it can be trimmed, but we are getting oblivious to common sense a little. This is system language.

tatterdemalion 11y ago
By default Rust statically links the standard library into every program. For binaries it also statically links to jemalloc by default to use as the allocator. This is a large constant factory that makes trivial programs significantly larger than C, but like all constant factors it becomes insignificant when n is larger. Binary size is not a major concern for most programs, even those written in a systems language. If it is a concern for your use case, you can use dynamic linking and the system allocator to get the size down to the same scale as C.
Manishearth 11y ago
That 250K is additive, not multiplicative. Hello World, which might be 10K in C, will be 240K+10K=250K in Rust. A larger program that would be 2M in C would be 240K+2M in Rust; the significance of that 240K reduces when you write actual programs (instead of hello world). The size is due to a statically linked stdlib (also jemalloc, which you can decide not to use) -- your C program is tiny because your system has a stdlib it can dynamically link to. Rust can do this too, it's just not the default since in most cases this additive extra binary size isn't a problem. Being a systems language does mean we should forgo sensible defaults.
- mystikal 11y ago
  In theory you could tell the compiler to identify and statically link only those functions needed to make printf work (or a conservative approximation thereof).
  - danieldk 11y ago
    As far as I know, jemalloc is a substantial part of that binary size. See e.g.: https://github.com/japaric/rust-on-openwrt/issues/1#issuecomment-108425440 https://github.com/japaric/rust-on-openwrt/issues/1#issuecom... https://github.com/japaric/std-with-cargo#making-rust-binaries-smaller https://github.com/japaric/std-with-cargo#making-rust-binari...
  - Manishearth 11y ago
    Yeah, that's just running LTO (`-C lto`). This brings the binary size down a bit, thought you also need to opt out of jemalloc to get a good impact.
- Manishearth 11y ago
  Edit: *doesn't
ternaryoperator 11y ago
The great wit, Stan Kelly-Bootle, once observed (about Turbo C): "It generated a 40KB executable when I wrote my first 'Hello, World!' program. After that, I dared not say 'Goodbye.'"
- desireco42 11y ago
  Finally someone understands what I wrote, thanks man
  - pcwalton 11y ago
    I read the exact opposite point.
- zerr 11y ago
  On the contrary, when Borland C++ Builder (i.e. "Delphi for C++") generated an executable for the app with a GUI, my first reaction was - it's so small, no way this can be a standalone executable, I can't give this to client... :)
lifthrasiir 11y ago
$ cat hello.rs fn main() { println!("Hello, world!") } $ rustc hello.rs -C prefer-dynamic $ ./hello Hello, world! $ ls -al hello -rwxrwxr-x 1 lifthrasiir 9064 Mar 4 14:24 hello* See other comments for the explanation.
whyever 11y ago
You can go under 1k if you don't use the standard library: https://github.com/retep998/hello-rs https://github.com/retep998/hello-rs
- Ygg2 11y ago
  You can go 151 bytes if you are ready to do some link shenanigans: http://mainisusuallyafunction.blogspot.rs/2015/01/151-byte-static-linux-binary-in-rust.html http://mainisusuallyafunction.blogspot.rs/2015/01/151-byte-s...

250K for hello world example... where is this world going to! :) I am sure it can be trimmed, but we are getting oblivious to common sense a little. This is system language.

tatterdemalion 11y ago

By default Rust statically links the standard library into every program. For binaries it also statically links to jemalloc by default to use as the allocator. This is a large constant factory that makes trivial programs significantly larger than C, but like all constant factors it becomes insignificant when n is larger. Binary size is not a major concern for most programs, even those written in a systems language. If it is a concern for your use case, you can use dynamic linking and the system allocator to get the size down to the same scale as C.

Manishearth 11y ago

That 250K is additive, not multiplicative. Hello World, which might be 10K in C, will be 240K+10K=250K in Rust. A larger program that would be 2M in C would be 240K+2M in Rust; the significance of that 240K reduces when you write actual programs (instead of hello world). The size is due to a statically linked stdlib (also jemalloc, which you can decide not to use) -- your C program is tiny because your system has a stdlib it can dynamically link to. Rust can do this too, it's just not the default since in most cases this additive extra binary size isn't a problem. Being a systems language does mean we should forgo sensible defaults.

mystikal 11y ago
In theory you could tell the compiler to identify and statically link only those functions needed to make printf work (or a conservative approximation thereof).
- danieldk 11y ago
  As far as I know, jemalloc is a substantial part of that binary size. See e.g.: https://github.com/japaric/rust-on-openwrt/issues/1#issuecomment-108425440 https://github.com/japaric/rust-on-openwrt/issues/1#issuecom... https://github.com/japaric/std-with-cargo#making-rust-binaries-smaller https://github.com/japaric/std-with-cargo#making-rust-binari...
- Manishearth 11y ago
  Yeah, that's just running LTO (`-C lto`). This brings the binary size down a bit, thought you also need to opt out of jemalloc to get a good impact.
Manishearth 11y ago
Edit: *doesn't

ternaryoperator 11y ago

The great wit, Stan Kelly-Bootle, once observed (about Turbo C): "It generated a 40KB executable when I wrote my first 'Hello, World!' program. After that, I dared not say 'Goodbye.'"

desireco42 11y ago
Finally someone understands what I wrote, thanks man
- pcwalton 11y ago
  I read the exact opposite point.
zerr 11y ago
On the contrary, when Borland C++ Builder (i.e. "Delphi for C++") generated an executable for the app with a GUI, my first reaction was - it's so small, no way this can be a standalone executable, I can't give this to client... :)

lifthrasiir 11y ago

$ cat hello.rs fn main() { println!("Hello, world!") } $ rustc hello.rs -C prefer-dynamic $ ./hello Hello, world! $ ls -al hello -rwxrwxr-x 1 lifthrasiir 9064 Mar 4 14:24 hello* See other comments for the explanation.

whyever 11y ago

You can go under 1k if you don't use the standard library: https://github.com/retep998/hello-rs https://github.com/retep998/hello-rs

Ygg2 11y ago
You can go 151 bytes if you are ready to do some link shenanigans: http://mainisusuallyafunction.blogspot.rs/2015/01/151-byte-static-linux-binary-in-rust.html http://mainisusuallyafunction.blogspot.rs/2015/01/151-byte-s...