Compile virgil code to WASM

[kalwalt]

I'm trying to compile some virgil code to WASM, i looked at the mandelbrot example and i would playing around with it. As stated in the Readme https://github.com/titzer/virgil?tab=readme-ov-file#supported-targets WASM is supported.
i run w3c-wasm Code.v3
but as a result v3c-wasm: command not found
Note that i have virgil/bin and virgil/bin/dev in PATH, i have also run aeneas bootstrap.
Maybe i missed some steps?
Anyway i can produce a wasm file with the wasi backend with the v3c-wasi command but it can not be load in a browser.

POST EDIT:
To compile to WASM run for example v3c -target=wasm -heap-size=500m YourCode.v3 the heap size option is needed to avoid unreachable code.

[kalwalt]

Ok i think i get it, you need to run v3c -target=wasm YourCode.v3 this is correct?

[kalwalt]

Note for other virgil users exporting to target wasm: It's better to enlarge the heap memory otherwise you can receive unreachable code, use the command:
v3c -target=wasm -heap-size=500m YourCode.v3

[titzer]

Yeah, that's a good tip. The wasm target is also a little less user-friendly in that any safety violations that would normally print a stack traces just trap (typically with unreachable). I.e. there isn't a nice source-level error message.

I should really get around to writing some tutorial pages on how to use the various targets.

[kalwalt]

@titzer i saw that you write a new tutorial for wasm, many thanks for this! I think it will help many potential users...

[titzer]

That's correct. The wasm code generator is stable, but none of the platform targets are stable enough to have graduated from bin/dev/ to bin/ yet.

[kalwalt]

Thank you, this make sense. 🙂

[gmlewis]

In addition to the -heap-size=500m suggestion above (thank you!)
I've noticed that if I include lib/util/*.v3 into my build, that I have to add this to my code in order to get it to successfully compile for -target=wasm:

// Hack to compile to wasm: provide Virgil identifiers that cannot be found:
component System {
  def error(s1: string, s2: string) {}
  def fileClose(file: int) {}
  def fileWriteK(file: int, data: Array<byte>, offset: int, length: int) {}
}

[titzer]

Thanks, it looks like lib/util/IO.v3 is responsible for the two file methods and System.error() is used in a couple places in BitMatrix and StringBuilder. TBH the Buffer and Stream abstractions in the former aren't particularly useful and I've considered removing them; they also predate Range, so they could use some improvement.

[gmlewis]

While looking for string interpolation, I found the StringBuilder, and am using that, but if you have other recommendations, I'm totally open.
Thanks for the cool programming language, @titzer (and your YouTube talks, which is how I found it)!

[kalwalt]

In addition to the -heap-size=500m suggestion above (thank you!) I've noticed that if I include lib/util/*.v3 into my build, that I have to add this to my code in order to get it to successfully compile for -target=wasm:

// Hack to compile to wasm: provide Virgil identifiers that cannot be found:
component System {
  def error(s1: string, s2: string) {}
  def fileClose(file: int) {}
  def fileWriteK(file: int, data: Array<byte>, offset: int, length: int) {}
}

You are welcome @gmlewis Glenn! Nice taht you find useful this post in some way. note aslo that Ben @titzer has updated the documentation for Wasm compilation, it should be noted on top of this topic.
And yes this is a cool programming language!

[gmlewis]

note aslo that Ben @titzer has updated the documentation for Wasm compilation, it should be noted on top of this topic.

Yes, however I didn't find your -heap-size=500m "trick" in the new documentation either. 😄

[kalwalt]

note aslo that Ben @titzer has updated the documentation for Wasm compilation, it should be noted on top of this topic.

Yes, however I didn't find your -heap-size=500m "trick" in the new documentation either. 😄

Yes you are right, I don't know if it make sense to update the wasm tutorial but at least i can add a Post Edit note on the very top of this thread. Don't know why we need to set the size of the heap, using emscripten with C/C++ -> Wasm you can add the _sALLOW_MEMORY_GROWTH option, and you are fine. But E,mscripten add alot of code that maybe you will not need.