How to add `@Suppress` for `IrTypeOperatorCall` by...

# compiler

[turansky]

How to add @Suppress for IrTypeOperatorCall by compiler plugin?

external interface INode

// before
val isNode = i is INode

// after
val isNode = @Suppress(
    "UNCHECKED_CAST_TO_EXTERNAL_INTERFACE",
    "USELESS_IS_CHECK"
) i is INode

[dmitriy.novozhilov]

Why do you need it?
If you want automaticlly suppress some diagnostics in existing code then such IR transformation doesn't help because of almost all diagnostics are reported before IR phase

[turansky]

I have custom strict implementation of is and as operators for some external interfaces.

By default:
• is operator for external interface = ERROR
• as operator for external interface = WARNING
I need suppress both for specific interfaces

[dmitriy.novozhilov]

I suggest you to look at DiagnosticSuppressor extension

[dmitriy.novozhilov]

https://github.com/JetBrains/kotlin/blob/master/compiler/frontend/src/org/jetbrains/kotlin/resolve/diagnostics/KotlinSuppressCache.kt

[turansky]

Could it be registered via SPI?

[dmitriy.novozhilov]

It's regular extension point, like IrGenerationExtension

[turansky]

I register IrGenerationExtension via IrGenerationExtension.registerExtension

[turansky]

But DiagnosticSuppressor has no register method

[dmitriy.novozhilov]

Oh, I got it. Yes, suppressor should be registered using java services mechanism

[turansky]

Will it work in IR mode?

[dmitriy.novozhilov]

Should be. It's a frontend extension point

[turansky]

I declare suppressor in Kotlin Compiler plugin, but it has no effect

[turansky]

For test I suppress all warnings/errors with special type

[turansky]

And remove suppresses here

[turansky]

SPI registration doesn’t work

// This registration works
Extensions.getRootArea()
    .getExtensionPoint(DiagnosticSuppressor.EP_NAME)
    .registerExtension(YDiagnosticSuppressor())

@dmitriy.novozhilov Do I need to use plugin extension area instead?

[dmitriy.novozhilov]

Sorry, I didn't write any plugins for two years so I forgot some details.
For your plugin you need to declare ComponentRegistrar service and then register all your extensions in it
See how it done in e.g. allopen plugin:
https://github.com/JetBrains/kotlin/tree/master/plugins/allopen/allopen-cli/resources/META-INF/services
https://github.com/JetBrains/kotlin/blob/master/plugins/allopen/allopen-cli/src/AllOpenPlugin.kt#L68

[turansky]

Registration in project root doesn’t work as expected 😞

How I can calculate KtClass associated with KtTypeReference?

[dmitriy.novozhilov]

Try to implement fun isSuppressed(diagnostic: Diagnostic, bindingContext: BindingContext?): Boolean instead of fun isSuppressed(diagnostic: Diagnostic): Boolean
Binding context should contain KotlinType you want in TYPE slice
https://github.com/JetBrains/kotlin/blob/master/compiler/frontend/src/org/jetbrains/kotlin/resolve/BindingContext.java#L97

[turansky]

What about ExtensionArea for suppressor? Could I use Extensions.getRootArea() (other extensions use MockProject.extensionArea)?

[dmitriy.novozhilov]

I think you should use MockProject as other extensions. But it's a assumption since I don't exactly know how this machinery works

[turansky]

Looks like suppress configuration is global by default (in implementation).

Is there anybody who can know exactly?