I’m having some issues with the <kotlin wasm wasi example>, I’ve included the the wasm file it gener...

# webassembly

[Charlie Tapping]

I’m having some issues with the kotlin wasm wasi example, I’ve included the the wasm file it generates by running build. If I give this to the interpreter included in the wasm gc proposal it crashes with “invalid section id”. Is this using old opcodes perhaps? I was trying to convert it to wat format so I could debug it

kotlin-wasm-wasi-example-wasm-wasi.wasm

[Charlie Tapping]

ah maybe it needs to exception handling proposal also?

[Charlie Tapping]

This seems to be the answer as the section id is 13 which is a new section in the exception proposal, is there a way to turn off exception support. I read about a compiler flag -Xwasm-use-traps-instead-of-exceptions but I can’t seem to get it to work 🤔

[bashor]

Right, normally EH proposal is required but with -Xwasm-use-traps-instead-of-exceptions you can replace throws with trap (unreachable), so instead of throwing exceptions wasm module will be stopped execution.

[bashor]

Add following to build.gradle.kts

tasks.withType<KotlinJsCompile>().configureEach {
    kotlinOptions.freeCompilerArgs += listOf("-Xwasm-use-traps-instead-of-exceptions")
}

[Charlie Tapping]

That worked thank you !

[bashor]

JFTR: added the block to the example
https://github.com/Kotlin/kotlin-wasm-examples/blob/main/wasi-example/build.gradle.kts#L171-L177

[Charlie Tapping]

With that flag enabled chasm can now decode binaries output by the kotlin compiler

[bashor]

Good job!