Implement simple cache for dynamically created wrapper for defaults

compiler/ir/ir.interpreter/src/org/jetbrains/kotlin/ir/interpreter/InstructionsUnfolder.kt

@@ -18,6 +18,7 @@ import org.jetbrains.kotlin.ir.interpreter.stack.Variable
 import org.jetbrains.kotlin.ir.interpreter.state.*
 import org.jetbrains.kotlin.ir.types.classOrNull
 import org.jetbrains.kotlin.ir.types.isUnit
+import org.jetbrains.kotlin.ir.types.makeNullable
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.name.Name
 
@@ -35,10 +36,10 @@ internal fun unfoldInstruction(element: IrElement?, environment: IrInterpreterEn
         null -> return
         is IrSimpleFunction -> unfoldFunction(element, environment)
         is IrConstructor -> unfoldConstructor(element, callStack)
-        is IrCall -> unfoldValueParameters(element, callStack)
-        is IrConstructorCall -> unfoldValueParameters(element, callStack)
-        is IrEnumConstructorCall -> unfoldValueParameters(element, callStack)
-        is IrDelegatingConstructorCall -> unfoldValueParameters(element, callStack)
+        is IrCall -> unfoldValueParameters(element, environment)
+        is IrConstructorCall -> unfoldValueParameters(element, environment)
+        is IrEnumConstructorCall -> unfoldValueParameters(element, environment)
+        is IrDelegatingConstructorCall -> unfoldValueParameters(element, environment)
         is IrInstanceInitializerCall -> unfoldInstanceInitializerCall(element, callStack)
         is IrField -> unfoldField(element, callStack)
         is IrBody -> unfoldBody(element, callStack)
@@ -108,13 +109,19 @@ private fun unfoldConstructor(constructor: IrConstructor, callStack: CallStack)
     }
 }
 
-private fun unfoldValueParameters(expression: IrFunctionAccessExpression, callStack: CallStack) {
+private fun unfoldValueParameters(expression: IrFunctionAccessExpression, environment: IrInterpreterEnvironment) {
+    val callStack = environment.callStack
     val hasDefaults = (0 until expression.valueArgumentsCount).any { expression.getValueArgument(it) == null }
     if (hasDefaults) {
+        val ownerWithDefaults = expression.getFunctionThatContainsDefaults()
+        environment.cachedFunctionsWithDefaults[ownerWithDefaults.symbol]?.let {
+            val callToDefault = it.owner.createCall().apply { expression.copyArgsInto(this) }
+            callStack.addInstruction(CompoundInstruction(callToDefault))
+            return
+        }
+
         // if some arguments are not defined, then it is necessary to create temp function where defaults will be evaluated
         val actualParameters = MutableList<IrValueDeclaration?>(expression.valueArgumentsCount) { null }
-        val ownerWithDefaults = expression.getFunctionThatContainsDefaults()
-
         val visibility = when (expression) {
             is IrEnumConstructorCall, is IrDelegatingConstructorCall -> DescriptorVisibilities.LOCAL
             else -> ownerWithDefaults.visibility
@@ -128,14 +135,20 @@ private fun unfoldValueParameters(expression: IrFunctionAccessExpression, callSt
             this.dispatchReceiverParameter = ownerWithDefaults.dispatchReceiverParameter?.deepCopyWithSymbols(this)
             this.extensionReceiverParameter = ownerWithDefaults.extensionReceiverParameter?.deepCopyWithSymbols(this)
             (0 until expression.valueArgumentsCount).forEach { index ->
-                val parameter = ownerWithDefaults.valueParameters[index]
-                actualParameters[index] = if (expression.getValueArgument(index) != null) {
-                    parameter.deepCopyWithSymbols(this).also { this.valueParameters += it }
-                } else {
-                    parameter.createTempVariable().apply variable@{
-                        this@variable.initializer = parameter.getDefaultWithActualParameters(this@apply, actualParameters)
-                            ?: expression.getVarargType(index)?.let { null.toIrConst(it) } // if parameter is vararg and it is missing
+                val originalParameter = ownerWithDefaults.valueParameters[index]
+                val copiedParameter = originalParameter.deepCopyWithSymbols(this)
+                this.valueParameters += copiedParameter
+                actualParameters[index] = if (copiedParameter.defaultValue != null) {
+                    copiedParameter.type = copiedParameter.type.makeNullable() // make nullable type to keep consistency; parameter can be null if it is missing
+                    val irGetParameter = copiedParameter.createGetValue()
+                    val defaultInitializer = originalParameter.getDefaultWithActualParameters(this@apply, actualParameters)
+                        ?: expression.getVarargType(index)?.let { null.toIrConst(it) } // if parameter is vararg and it is missing
+
+                    copiedParameter.createTempVariable().apply variable@{
+                        this@variable.initializer = environment.irBuiltIns.irIfNullThenElse(irGetParameter, defaultInitializer!!, irGetParameter)
                     }
+                } else {
+                    copiedParameter
                 }
             }
         }
@@ -146,6 +159,7 @@ private fun unfoldValueParameters(expression: IrFunctionAccessExpression, callSt
         (0 until expression.valueArgumentsCount).forEach { callWithAllArgs.putValueArgument(it, actualParameters[it]?.createGetValue()) }
         defaultFun.body = (actualParameters.filterIsInstance<IrVariable>() + defaultFun.createReturn(callWithAllArgs)).wrapWithBlockBody()
 
+        environment.cachedFunctionsWithDefaults[ownerWithDefaults.symbol] = defaultFun.symbol
         val callToDefault = defaultFun.createCall().apply { expression.copyArgsInto(this) }
         callStack.addInstruction(CompoundInstruction(callToDefault))
     } else {

compiler/ir/ir.interpreter/src/org/jetbrains/kotlin/ir/interpreter/IrInterpreterEnvironment.kt

@@ -7,7 +7,6 @@ package org.jetbrains.kotlin.ir.interpreter
 
 import org.jetbrains.kotlin.ir.IrBuiltIns
 import org.jetbrains.kotlin.ir.declarations.IrClass
-import org.jetbrains.kotlin.ir.declarations.IrFunction
 import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
 import org.jetbrains.kotlin.ir.interpreter.stack.CallStack
 import org.jetbrains.kotlin.ir.interpreter.state.Common
@@ -24,6 +23,7 @@ class IrInterpreterEnvironment(
     internal val irExceptions = mutableListOf<IrClass>()
     internal var mapOfEnums = mutableMapOf<IrSymbol, Complex>()
     internal var mapOfObjects = mutableMapOf<IrSymbol, Complex>()
+    internal var cachedFunctionsWithDefaults = mutableMapOf<IrFunctionSymbol, IrFunctionSymbol>()
     internal var cachedLambdasAndReferences = mutableMapOf<IrFunctionSymbol, IrFunctionSymbol>()
 
     init {

compiler/ir/ir.interpreter/src/org/jetbrains/kotlin/ir/interpreter/IrTreeBuildUtils.kt

@@ -99,9 +99,9 @@ internal fun State.toIrExpression(expression: IrExpression): IrExpression {
     }
 }
 
-internal fun IrFunction.createCall(): IrCall {
+internal fun IrFunction.createCall(origin: IrStatementOrigin? = null): IrCall {
     this as IrSimpleFunction
-    return IrCallImpl(SYNTHETIC_OFFSET, SYNTHETIC_OFFSET, returnType, symbol, typeParameters.size, valueParameters.size)
+    return IrCallImpl(SYNTHETIC_OFFSET, SYNTHETIC_OFFSET, returnType, symbol, typeParameters.size, valueParameters.size, origin)
 }
 
 internal fun IrConstructor.createConstructorCall(): IrConstructorCall {
@@ -166,9 +166,27 @@ internal fun IrFunctionAccessExpression.shallowCopy(copyTypeArguments: Boolean =
 }
 
 internal fun IrFunctionAccessExpression.copyArgsInto(newCall: IrFunctionAccessExpression) {
+    val symbol = this.symbol.owner
     newCall.dispatchReceiver = this.dispatchReceiver
     newCall.extensionReceiver = this.extensionReceiver
     (0 until this.valueArgumentsCount)
-        .mapNotNull { this.getValueArgument(it) }
-        .forEachIndexed { i, arg -> newCall.putValueArgument(i, arg) }
-}
+        .map { this.getValueArgument(it) }
+        .forEachIndexed { i, arg ->
+            newCall.putValueArgument(i, arg ?: IrConstImpl.constNull(SYNTHETIC_OFFSET, SYNTHETIC_OFFSET, symbol.valueParameters[i].type))
+        }
+}
+
+internal fun IrBuiltIns.irEquals(arg1: IrExpression, arg2: IrExpression): IrCall {
+    val equalsCall = this.eqeqSymbol.owner.createCall(IrStatementOrigin.EQEQ)
+    equalsCall.putValueArgument(0, arg1)
+    equalsCall.putValueArgument(1, arg2)
+    return equalsCall
+}
+
+internal fun IrBuiltIns.irIfNullThenElse(nullableArg: IrExpression, ifTrue: IrExpression, ifFalse: IrExpression): IrWhen {
+    val nullCondition = this.irEquals(nullableArg, IrConstImpl.constNull(SYNTHETIC_OFFSET, SYNTHETIC_OFFSET, this.anyNType))
+    val trueBranch = IrBranchImpl(nullCondition, ifTrue) // use default
+    val elseBranch = IrElseBranchImpl(IrConstImpl.constTrue(0, 0, this.booleanType), ifFalse)
+
+    return IrIfThenElseImpl(SYNTHETIC_OFFSET, SYNTHETIC_OFFSET, ifTrue.type).apply { branches += listOf(trueBranch, elseBranch) }
+}