Stream: wasi

Topic: ✔ Disable importing of packages wasi:cli, wasi:io etc

lkjhaisduhjfkxcjvbnis (Aug 06 2024 at 12:45):

I am trying to build a very simple application with components that does not depend on any other packages. just some functions. When I compile my guest project to a core wasm module everything seems to be working just fine, with the output of wasm-tools component wit <core.wasm> being

package root:root {
  world root {
    export hello-world: func() -> string;
  }
}


package component:sus {
  world example {
    export hello-world: func() -> string;
  }
}

However when i convert the core module to a component with
wasm-tools component new --adapt wasi_snapshot_preview1=latest_wasi_snapshot_preview1.reactor.wasm <core.wasm> -o component.wasm
It adds dependencies on a bunch of standard packages:

...

package root:component {
  world root {
    import wasi:cli/environment@0.2.0;
    import wasi:cli/exit@0.2.0;
    import wasi:io/error@0.2.0;
    import wasi:io/streams@0.2.0;
    import wasi:cli/stdin@0.2.0;
    import wasi:cli/stdout@0.2.0;
    import wasi:cli/stderr@0.2.0;
    import wasi:clocks/wall-clock@0.2.0;
    import wasi:filesystem/types@0.2.0;
    import wasi:filesystem/preopens@0.2.0;

    export hello-world: func() -> string;
  }
}

I do not want to support these packages on my host so how can i avoid importing these?

Alex Crichton (Aug 06 2024 at 12:47):

If you're using Rust as a source language you can use the wasm32-unknown-unknown target for this

lkjhaisduhjfkxcjvbnis (Aug 06 2024 at 12:47):

oh great let me try that. is there documentation on this? i have only ever seen the wasm32-wasip1 target in use

Alex Crichton (Aug 06 2024 at 12:49):

No documentation I know of myself, but the workflow should be the same (note that things like println in the standard library won't work)

lkjhaisduhjfkxcjvbnis (Aug 06 2024 at 12:51):

Ok so do i understand this correctly that the wasm32-wasip1 requires these core packages to be present to make the std lib work and wasm32-unknown-unknown does not and hence does not support the stdlib?

Alex Crichton (Aug 06 2024 at 13:04):

more or less yeah

lkjhaisduhjfkxcjvbnis (Aug 06 2024 at 13:06):

It works! Thank you so much for your help!

Notification Bot (Aug 06 2024 at 13:15):

lkjhaisduhjfkxcjvbnis has marked this topic as resolved.

Last updated: Dec 23 2024 at 13:07 UTC