Well, is this a know issue? or should I file a tic...

# webassembly

[andylamax]

Well, is this a know issue? or should I file a ticket??

val res = try {
     10 / 0
 } catch (_: Throwable) {
    0
 }
 res==0 // true

Fails in wasmJs and wasmWasi but passes in all other platforms (tested on jvm,js,linux).

Funny thing is, changing it to

val res = try {
     throw ArithmeticException("No can't do")
 } catch (_: Throwable) {
    0
 }
 res==0 // true

Works on all.

Should I file a ticker??

[Robert Jaros]

There are other types of errors, which are not caught by try/catch with Throwable.

[Robert Jaros]

e.g. arrayOf(1)[3] fails

[andylamax]

How does one approach errors that can't be caught by try/catch?? the old c way??

[Robert Jaros]

I think it's a bug.

[Robert Jaros]

Just not specific to division by zero but to try/catch in general.

[Robert Jaros]

Just found this issue: https://youtrack.jetbrains.com/issue/KT-59081/WASM-Cant-catch-index-out-of-bounds-and-divide-by-0-exceptions

[Svyatoslav Kuzmich [JB]]

I would call this a bug.

This behaviour was intentionally implemented as a trap instead of an exception, in order to benchmark performance of the “happy path”, hoping that a special Wasm support will be available to avoid duplicate checks (one in the engine and one in the Wasm code).

Now that Kotlin/Wasm is released for more than just benchmarking, I’m thinking it should throw a normal exception by default, and maybe have a flag to do the optimised trapping version.

[andylamax]

Is the filed ticket enough? Or should I file another one?

[Svyatoslav Kuzmich [JB]]

One is enough 🙂