Compiling Rust to Web Assembly

https://medium.com/@chicoxyzzy/compiling-rust-to-webassembly-guide-411066a69fde#.x4y184tj6

by grey-area • 10 years ago

289 68 10 years ago

Three rust articles on the front page? Not complaining, it definitely seems like the popularity has really jumped up in the last three months.

hacker_92• 10 years ago

Rust and Go are always on the front page.

rch• 10 years ago

Also Python, JS frameworks, CLR and JVM languages, C/C++, LLVM, notably obscure languages... It's like there's some kind of theme.

lacampbell3• 10 years ago

If someone makes a Go compiler in Rust hacker news will have to shut down. Game over, there is nothing left to do in computing.

swsieber• 10 years ago

As far as I know it's because the Rust is filling in the gaps - two of the three articles are about relatively new features. And the next Rust release should close the stable/unstable gap by stabilizing some macro/compiler plugin stuff.

pekk• 10 years ago

It is a marketing push. Marketing pushes don't have to correlate to massive improvements in the product.

lacampbell3• 10 years ago

TBH it's getting a bit much at this point. The rust advocates here (not sure if they're paid or just fanboys) really need to tone it down. The hyperbole, and the constant "rust solves this unrelated problem, and has no flaws!" is beginning to grate.

I've coded in it a bit and it seems like cool language, they get a lot right and have some new and interesting ideas. But it's not a panacea (or indeed "salvation" as one recent blog post put it) for everything wrong in software. We don't need to all immediately re-write everything we do rust. Not everything new needs to be written in rust. And your re-writes of programs that have already been written in other languages and work well aren't that compelling.

If you like rust, then write some new, interesting and useful software in the language, where what language it's written in isn't the main selling point. For example, I love the look of this http://nickel.rs/.

TL;DR - the corrosive nature of rust advocates on HN is starting to eat away at my patience, and I am tired of having to galvanize against them and their absurd claims.

burntsushi• 10 years ago

Yes, we had a recent explosion of marketing materials that went a little over the top. That's OK. It happens.

I don't think anyone really believes Rust solves every problem, so I think you're attacking a straw man. There are plenty of trade offs at play. But the problems we believe it does solve makes it exciting for a lot of us (and for perspective users).

hacker_92• 10 years ago

As a counter, stuff is posted to new every minute, but 90% of it doesn't reach the front page. In order to reach the front, you often have to do make up silly titles such as the ones you mentioned, which cause an emotional response (good or bad, as long as it gets clicks).

HN also has a problem with brigading, which is why you see some utterly random articles make it to the top too. Sadly not much you can do about this, but you could try browsing /r/programming or elsewhere instead.

dikaiosune2• 10 years ago

the corrosive nature of rust

Fantastic!

More seriously, I'm not sure who you mean by the paid rust advocates here. There are some core developers who work for Mozilla, but I can't imagine that a Rust-using company or individual would spend salary on an HN advocate rather than paying someone to work on the compiler or ecosystem.

grey-area• 10 years ago

Hello, I posted this because it looked interesting. I'm not a Rust advocate (I prefer GC-languages personally), the WebAssembly angle and different languages using it as a compilation target was more interesting than Rust specifically.

Manishearth5• 10 years ago

Like burntsushi I feel you're attacking a straw man here. Or, you're attacking specifically the "salvation" article which was a bit hyperbolic on purpose (in which case you're mostly off topic in this thread)

the constant "rust solves this unrelated problem, and has no flaws!"

Where do you see that?

But it's not a panacea for everything wrong in software

Nobody says that. Folks generally focus on the memory safety and thread safety bits. The salvation article did say that Rust can solve all of the problems in software caused by C, which was hyperbolic (I wasn't really fond of that part either), but that's the only instance in a blog post or comment that I can recall this being said recently. There doesn't seem to be a trend as you see.

We don't need to all immediately re-write everything we do rust. Not everything new needs to be written in rust.

Nobody says that either. If anything, I've seen folks (especially in /r/rust) advocating caution when asked about porting software to Rust.

If you like rust, then write some new, interesting and useful software in the language, where what language it's written in isn't the main selling point.

There's a lot of this all over the rust community. Redox has reasons for existing other than Rust (https://doc.redox-os.org/book/introduction/why_redox.html). Servo similarly has a wide variety of interesting bits -- some of which have been enabled by Rust but aren't interesting because of Rust. Webrender in particular is something that could have been done without Rust. Servo's layout and style systems are pretty revolutionary, because of the way they work. Ripgrep (http://blog.burntsushi.net/ripgrep/) probably could have been implemented in Go and perhaps still win on some of the benchmarks; it's interesting because of the tricks that burntsushi used. https://github.com/google/xi-editor is also interesting, though incomplete.

benjismith• 10 years ago

I enjoy reading about rust.

I don't know the language (yet), but I've been keeping my eye on it for a few years, and I think it's going to be fantastic once it stabilizes and gets improved tooling.

I especially welcome the possibility of using a safe language like rust for web development, instead of writing more dreadful javascript...

pcwalton2• 10 years ago

And your re-writes of programs that have already been written in other languages and work well aren't that compelling.

Try ripgrep.

ruster• 10 years ago

and what's the argument here?

flukus2• 10 years ago

Quite a few of us made learning rust our new years resolution in recent threads.

anamoulous• 10 years ago

More Rust discussion and less "future of media/ad supported businesses" discussion works for me.

flukus2• 10 years ago

Not to mention fake news and politics in general.

tps5• 10 years ago

Nice guide.

I did this over the holidays just to see it in action. It was a pain to get the emscripten sdk installed (especially on a slow connection) but it's quite cool to see it in action.

There's also a asm.js target which you can add like this:

$ rustup target add asmjs-unknown-emscripten

I'm not sure about browser support for asm.js but recent versions of node support it.

wildmusings• 10 years ago

Every browser supports asm.js, since it's just a subset of standard JS. Some browsers do optimize it, though. https://en.wikipedia.org/wiki/Asm.js#Implementations

kibwen• 10 years ago

This is great, I've actually never seen the steps to compiling WASM laid out before.

What all does the Emscripten SDK provide?

hackcasual• 10 years ago

An HTML shell that can handle resource loading, plus a bunch of JS methods for providing IO to WebAssembly. In the future it will be possible to do something like https://github.com/brson/mir2wasm to go directly from LLVM to WASM (though IO functionality will need to be supplied separately).

rafinha• 10 years ago

Is there a way to debug apps compiled to Web assembly? (Like a gdb.js :D ) I suppose using standard dev tools won't be useful.

MayeulC• 10 years ago

That's one area where I would like to see web browsers cooperate a bit. At least Firefox and Chromium. This would give better tools to everyone. I won't bet on it, however.

empath75• 10 years ago

https://github.com/WebAssembly/design/blob/master/TextFormat...

rl32• 10 years ago

What's the binary size like compared to C/C++?

I've read the overhead of Rust's standard library is about 100kB. Not sure if putting it through the Emscripten toolchain changes that significantly.

steveklabnik2• 10 years ago

In general, https://lifthrasiir.github.io/rustlog/why-is-a-rust-executab...

For this specifically, I made some numbers when it first landed: https://www.reddit.com/r/rust/comments/575pp6/compiling_to_t...

Regardless, this is in a "oh my god it works" state, not a super serious best-we-can-do state. My understanding is that it's larger than it has to be at the moment. We'll get there.

rl32• 10 years ago

-rw-r--r-- 1 steve steve 159K Oct 12 20:00 sup.wasm

It's looking pretty good already. Thanks for the reply.

sunng• 10 years ago

Here is an example that using Rust-native library for web development: https://github.com/tcr/rust-todomvc

Also I forked it to use handlebars: https://github.com/sunng87/rust-todomvc

Using asmjs, the compiled js file is about 20MB and can be slow in browser. While wasm32 one is just ~500KB.

k__4• 10 years ago

Can wasm be chunked up and loaded on demand via AJAX, like JS?

ponytech• 10 years ago

Has anyone heard of python compiled to Web Assembly ?

coldtea2• 10 years ago

Python needs all the extra runtime and interpreter cannot just be compiled that easily, except with dropped features.

Freak_NL• 10 years ago

That reminds me of Google's GWT, which compiled Java to JavaScript and supported a limited subset of the JDK. Maintaining a legacy GWT codebase is not a very pleasant experience, because you are stuck in a Java-like abstraction layer on top of the actual browser features and the DOM.

I guess compiling a language like Rust to WebAssembly solves these issues for a part?

k__4• 10 years ago

As far as I know, if you don't want to add a runtime, you can only compile languages that compile to native code to Web Assembly. C, C++, D, Rust, Nim, etc.

So it's more for low level lanuages to make performance easier on the Web, not for replacing JavaScript in general.

dan00• 10 years ago

But don't need D und Nim a runtime for their garbage collection?

dangerbird2• 10 years ago

C-python runs on a bytecode interpreter, so theoretically you could port the VM to webassembly, provided you remove features that depend on a native operating system. More bare-bones interpreters like Lua (http://daurnimator.github.io/lua.vm.js/repl.html) and Chibi-scheme (https://chibi-scheme.appspot.com/) which have had their C compilers and vms ported to emscripten can run natively on the web. JIT interpreters like Juajit, Java Hotspot, and pypy, cannot easily run on webassembly or asm.js due to their dependency on native chipsets with self-modifying code support. Also, most of the tooling for wasm and asm.js relies on llvm, so a good amount of work would be required for compiled languages that don't have compilers emmitting llvm bytecode

marcosscriven• 10 years ago

I wasn't a fan of having to compile the dev branch of both emscripten itself, and clang, each time I wanted to try the latest (hence the 'wait 2 hours' in the blog)

I thus asked about providing a Docker image - the person that handles the builds and the SDKs says that nightly builds are on the way: https://github.com/kripken/emscripten/issues/4682#issuecomme...

brianshaler• 10 years ago

I read the guide and came here looking to see if there was a docker image. I just don't want to blindly pipe-sh on my host machine (would need to review what rustup is doing first). On top of that, 'wait 2 hours' is not something I want to do when I want to kick the tires on a Hello World.

This is a great example of docker-for-dev. Don't bother setting up the specific versions of compilers and then worry about clean-up afterward.

The guide should be 2 lines: docker pull, then docker run.

microo8• 10 years ago

Still waiting for an article named 'Compiling Go to Web Assembly' https://imgflip.com/s/meme/Ill-Just-Wait-Here.jpg

Compiling Rust to Web Assembly

Related Stories