Workaround incomplete inline for interop's readValue

Interop/Runtime/src/main/kotlin/kotlinx/cinterop/Utils.kt

@@ -203,9 +203,9 @@ fun <T : CVariable> CPointed.readValues(size: Int, align: Int): CValues<T> {
 inline fun <reified T : CVariable> T.readValues(count: Int): CValues<T> =
         this.readValues<T>(size = count * sizeOf<T>().toInt(), align = alignOf<T>())
 
-fun <T : CVariable> CPointed.readValue(size: Int, align: Int): CValue<T> {
-    val bytes = ByteArray(size)
-    nativeMemUtils.getByteArray(this, bytes, size)
+fun <T : CVariable> CPointed.readValue(size: Long, align: Int): CValue<T> {
+    val bytes = ByteArray(size.toInt())
+    nativeMemUtils.getByteArray(this, bytes, size.toInt())
     return object : CValue<T>() {
         override fun getPointer(placement: NativePlacement): CPointer<T> = placement.placeBytes(bytes, align)
         override val size get() = bytes.size
@@ -214,7 +214,7 @@ fun <T : CVariable> CPointed.readValue(size: Int, align: Int): CValue<T> {
 
 // Note: can't be declared as property due to possible clash with a struct field.
 // TODO: find better name.
-inline fun <reified T : CStructVar> T.readValue(): CValue<T> = this.readValue(sizeOf<T>().toInt(), alignOf<T>())
+inline fun <reified T : CStructVar> T.readValue(): CValue<T> = this.readValue(sizeOf<T>(), alignOf<T>())
 
 // TODO: optimize
 fun <T : CVariable> CValues<T>.getBytes(): ByteArray = memScoped {

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/InteropUtils.kt

@@ -103,6 +103,14 @@ internal class InteropBuiltIns(builtIns: KonanBuiltIns) {
         it.valueParameters.size == 0
     }
 
+    val readValue = packageScope.getContributedFunctions("readValue").single {
+        it.valueParameters.size == 0
+    }
+
+    val readValueBySizeAndAlign = packageScope.getContributedFunctions("readValue").single {
+        it.valueParameters.size == 2
+    }
+
     val typeOf = packageScope.getContributedFunctions("typeOf").single()
 
     val variableTypeClass =

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/InteropLowering.kt

@@ -32,6 +32,7 @@ import org.jetbrains.kotlin.ir.builders.irCall
 import org.jetbrains.kotlin.ir.builders.irGet
 import org.jetbrains.kotlin.ir.declarations.IrFile
 import org.jetbrains.kotlin.ir.expressions.*
+import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrCallableReferenceImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrConstImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrGetObjectValueImpl
@@ -179,6 +180,21 @@ private class InteropTransformer(val context: Context, val irFile: IrFile) : IrB
         return alloc(placement, size, align)
     }
 
+    private fun IrBuilderWithScope.readValue(receiver: IrExpression, typeArgument: KotlinType): IrCallImpl? {
+        val size = sizeOf(typeArgument) ?: return null
+        val align = alignOf(typeArgument) ?: return null
+
+        val callee = interop.readValueBySizeAndAlign
+        val typeParameter = callee.typeParameters.single()
+        val typeArguments = mapOf(typeParameter to typeArgument)
+
+        return irCall(callee, typeArguments).apply {
+            extensionReceiver = receiver
+            putValueArgument(0, size)
+            putValueArgument(1, align)
+        }
+    }
+
     override fun visitCall(expression: IrCall): IrExpression {
 
         expression.transformChildrenVoid(this)
@@ -252,6 +268,13 @@ private class InteropTransformer(val context: Context, val irFile: IrFile) : IrB
                 }
             }
 
+            interop.readValue -> {
+                val typeArgument = expression.getSingleTypeArgument()
+                val receiver = expression.extensionReceiver!!
+
+                builder.readValue(receiver, typeArgument) ?: expression
+            }
+
             interop.staticCFunction -> {
                 val argument = expression.getValueArgument(0)!!
                 if (argument !is IrCallableReference || argument.getArguments().isNotEmpty()) {

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/ir/builders/IrBuilders.kt

@@ -16,6 +16,8 @@
 
 package org.jetbrains.kotlin.ir.builders
 
+import org.jetbrains.kotlin.descriptors.CallableDescriptor
+import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
 import org.jetbrains.kotlin.descriptors.ValueDescriptor
 import org.jetbrains.kotlin.descriptors.VariableDescriptor
 import org.jetbrains.kotlin.ir.expressions.IrExpression
@@ -23,6 +25,8 @@ import org.jetbrains.kotlin.ir.expressions.IrLoop
 import org.jetbrains.kotlin.ir.expressions.IrStatementOrigin
 import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.TypeProjectionImpl
+import org.jetbrains.kotlin.types.TypeSubstitutor
 
 inline fun IrBuilderWithScope.irLetSequence(
         value: IrExpression,
@@ -50,3 +54,17 @@ fun IrBuilderWithScope.irTrue() = IrConstImpl.boolean(startOffset, endOffset, co
 
 fun IrBuilderWithScope.irGet(value: ValueDescriptor) =
         IrGetValueImpl(startOffset, endOffset, value)
+
+fun IrBuilderWithScope.irCall(
+        callee: CallableDescriptor,
+        typeArguments: Map<TypeParameterDescriptor, KotlinType>
+): IrCallImpl {
+    val substitutionContext = typeArguments.map { (typeParameter, typeArgument) ->
+        typeParameter.typeConstructor to TypeProjectionImpl(typeArgument)
+    }.toMap()
+
+    val substitutor = TypeSubstitutor.create(substitutionContext)
+    val substitutedCallee = callee.substitute(substitutor)!!
+
+    return IrCallImpl(this.startOffset, this.endOffset, substitutedCallee, typeArguments)
+}