Hi, is there a reason why `isIntOrNullableInt` is ...

# compiler

[Nabil]

Hi, is there a reason why isIntOrNullableInt is not available in KotlinBuiltIns ? (similar for example to isLongOrNullableLong ).
When using a property var age:Int? isInt returns false (which is correct) isNullablePrimitiveType returns true (which is correct), but there's no mechanism to detect a return type is Int or Int?

[dmitriy.novozhilov]

I guess because there were no need in this function. You can write you own `isIntOrNullableInt`:

fun isIntOrNullableInt(type: KotlinType): Boolean {
    return with(ClassicTypeCheckerContext()) {
        KotlinBuiltIns.isInt(type.withNullability(true))
    }
}

[Nabil]

Thanks Dmitriy, the following

fun IrType.isIntOrNullableInt(): Boolean {
    return with(ClassicTypeCheckerContext(false)) {
        KotlinBuiltIns.isInt(withNullability(true) as KotlinType)
    }
}

method (edited to compile) throws a compiler error

java.lang.IllegalArgumentException: ClassicTypeSystemContext couldn't handle: org.jetbrains.kotlin.ir.types.impl.IrSimpleTypeImpl@ad907df4, class org.jetbrains.kotlin.ir.types.impl.IrSimpleTypeImpl

[dmitriy.novozhilov]

IrType and KotlinType are different class hierarchies which are used in frontend and backend ir respectively. If you need check IrType for int you should use IrTypeCheckerContext and check like type.withNullability(true) == irBuiltins.intType

[Nabil]

sorry Dmitriy I'm a bit confused withNullability is not available for IrType

fun isIntOrNullableInt(type: IrType, context: IrPluginContext): Boolean {
    return with(IrTypeCheckerContext(context.irBuiltIns)) {
        context.irBuiltIns.intType == type.withNullability(true)
    }
}

[dmitriy.novozhilov]

Oh, I forgot that withNullability is available only for simple types
add if (type !is IrSimpleType) return false before return, and then it will work

[Nabil]

Hmm, this is somehow always returning false I'm calling it on the following IrType

[Kotlin Compiler] 2020-09-09T10:24:03.948Z DEBUG return type: org.jetbrains.kotlin.ir.types.impl.IrSimpleTypeImpl@ad907df4 dump : FUN DEFAULT_PROPERTY_ACCESSOR name:<get-age> visibility:public modality:FINAL <> ($shared.Person) returnType:<http://kotlin.Int|kotlin.Int>?
  correspondingProperty: PROPERTY name:age visibility:public modality:FINAL [var]
  $this: VALUE_PARAMETER name:<this> type:shared.Person
  BLOCK_BODY
    RETURN type=kotlin.Nothing from='public final fun <get-age> (): <http://kotlin.Int|kotlin.Int>? declared in shared.Person'
      GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:age type:<http://kotlin.Int|kotlin.Int>? visibility:private' type=<http://kotlin.Int|kotlin.Int>? origin=null
        receiver: GET_VAR '<this>: shared.Person declared in shared.Person.<get-age>' type=shared.Person origin=null
 EVALUATION1 false

from

fun IrFunction.isReturningInt(irBuiltIns: IrBuiltIns) : Boolean {
    return isPropertyAccessor
            && isGetter
            && returnType.isIntOrNullableInt(irBuiltIns)
}

fun IrType.isIntOrNullableInt(irBuiltIns: IrBuiltIns): Boolean {
    if (this !is IrSimpleType) return false
    return with(IrTypeCheckerContext(irBuiltIns)) {
        irBuiltIns.intType == withNullability(true)
    }
}

[dmitriy.novozhilov]

cc @Roman Artemev [JB]

[Roman Artemev [JB]]

I am a bit out of context. Am I correct that question is how to check IrType if it’s nullable? If so, there is an util IrType.isNullable(): Boolean in $kotlin/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/types/IrTypeUtils.kt:38

[dmitriy.novozhilov]

@Nabil wants to check that IrType is <http://kotlin.Int|kotlin.Int> or <http://kotlin.Int|kotlin.Int>?

[Roman Artemev [JB]]

So here is checker IrType.isInt() for Int in $kotlin/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/types/irTypePredicates.kt:58 which checks whether type is non-null <http://kotlin.int|kotlin.int> .

[Roman Artemev [JB]]

So to check if type is either Int or Int? you could do like irType.makeNotNull().isInt()

[Nabil]

Thanks this should work.