How do I get wasm output from the CLI compiler? I'...

# webassembly

[jw]

How do I get wasm output from the CLI compiler? I'm using the kotlinc-js binary with -Xwasm but still getting JS

[kang wang]

Try "kotlinc-native hello.kt -target wasm32 -o hello"

[jw]

Isn't that the old backend?

[kang wang]

Yes, the old one. You want the new IR approach one?

[jw]

yes. i'm poking around the Gradle plugin but it has so many abstractions i can't track down where it actually configures the JS IR compilation task

[jw]

here? https://cs.android.com/android-studio/kotlin/+/master:libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsIrTargetConfigurator.kt;l=75-77;drc=023b9bf284f0c8bec064269e5254b6792ce94ce7. but that's just -Xwasm

[jw]

okay i got it

[jw]

I added -Xir-per-module and -Xir-produce-js which I found via running a Gradle build with --debug. Very weird, but it produces what I expect now

[jw]

Well, kinda. It's a start toward getting closer to what Gradle produces.

[kang wang]

Can you paste the whole command with params to compile a kotlin file into wasm one? I also want to have a try.

[jw]

kotlinc-js -output out/lib.js -Xir-produce-js -Xwasm -libraries kotlin-stdlib-wasm-1.7.20.klib input.kt

[kang wang]

kylewong@KyleWongs-Work-MBP ir-wasm % kotlinc-js -output lib.js -Xir-produce-js -Xwasm -libraries kotlin-stdlib-wasm-1.7.20.klib input.kt
exception: java.lang.IllegalArgumentException: Function getVirtualMethodId not found
at org.jetbrains.kotlin.backend.wasm.WasmSymbols.getFunction(WasmSymbols.kt:294)
at org.jetbrains.kotlin.backend.wasm.WasmSymbols.getInternalFunction(WasmSymbols.kt:305)
at org.jetbrains.kotlin.backend.wasm.WasmSymbols.<init>(WasmSymbols.kt:173)
at org.jetbrains.kotlin.backend.wasm.WasmBackendContext.<init>(WasmBackendContext.kt:105)
at org.jetbrains.kotlin.backend.wasm.CompilerKt.compileToLoweredIr(compiler.kt:51)
at org.jetbrains.kotlin.cli.js.K2JsIrCompiler.doExecute(K2JsIrCompiler.kt:345)
at org.jetbrains.kotlin.cli.js.K2JSCompiler.doExecute(K2JSCompiler.java:183)
at org.jetbrains.kotlin.cli.js.K2JSCompiler.doExecute(K2JSCompiler.java:72)
at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:94)
at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:43)
at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:101)
at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:79)
at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:43)
at org.jetbrains.kotlin.cli.common.CLITool$Companion.doMainNoExit(CLITool.kt:179)
at org.jetbrains.kotlin.cli.common.CLITool$Companion.doMainNoExit$default(CLITool.kt:177)
at org.jetbrains.kotlin.cli.common.CLITool$Companion.doMain(CLITool.kt:166)
at org.jetbrains.kotlin.cli.common.CLITool.doMain(CLITool.kt)
at org.jetbrains.kotlin.cli.js.K2JSCompiler.main(K2JSCompiler.java:100)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.jetbrains.kotlin.preloading.Preloader.run(Preloader.java:87)
at org.jetbrains.kotlin.preloading.Preloader.main(Preloader.java:44)

[kang wang]

@jw Did I miss something? I met error with the same command you used.

[jw]

I'm not sure. If you build with Gradle and run with --debug you can see all the flags that it uses to invoke the JS compiler to produce WASM output. That's what I did.

[Svyatoslav Kuzmich [JB]]

@kang wang check that your path in -libraries /path/to/kotlin-stdlib-wasm-1.7.20.klib leads to an actual kotlin-stdlib-wasm-1.7.20.klib file

[Svyatoslav Kuzmich [JB]]

We should, obviously, include stdlib by default when we have a real CLI. Current CLI is not really meant to be used manually without Gradle.