From e00dc766456b94ad00a388be7c50349c6e2c04da Mon Sep 17 00:00:00 2001
From: Ivan Kylchik <ivan.kylchik@jetbrains.com>
Date: Mon, 13 Apr 2020 21:19:32 +0300
Subject: [PATCH] Simplify constructor interpretation

Unified case with secondary and primary constructors
---
 .../common/interpreter/IrInterpreter.kt       | 19 ++++++-------------
 .../common/interpreter/state/Complex.kt       | 15 +++++++++++----
 2 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/interpreter/IrInterpreter.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/interpreter/IrInterpreter.kt
index 76370b51306..c86461e2e6b 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/interpreter/IrInterpreter.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/interpreter/IrInterpreter.kt
@@ -427,7 +427,6 @@ class IrInterpreter(irModule: IrModuleFragment) {
 
     private suspend fun interpretConstructor(constructorCall: IrFunctionAccessExpression): ExecutionResult {
         val owner = constructorCall.symbol.owner
-        val isPrimary = (owner as IrConstructor).isPrimary
         val valueArguments = mutableListOf<Variable>()
 
         interpretValueParameters(constructorCall, owner, valueArguments).check { return it }
@@ -472,23 +471,17 @@ class IrInterpreter(irModule: IrModuleFragment) {
             return Next
         }
 
-        val receiverState = Common(parent)
-        valueArguments.add(Variable(constructorCall.getThisAsReceiver(), receiverState)) //used to set up fields in body
+        val state = Common(parent)
+        valueArguments.add(Variable(constructorCall.getThisAsReceiver(), state)) //used to set up fields in body
         return stack.newFrame(initPool = valueArguments) {
             val statements = constructorCall.getBody()!!.statements
-            when (val first = statements[0]) {
-                // enum entry use IrTypeOperatorCall with IMPLICIT_COERCION_TO_UNIT as delegation call, but we need the value
-                is IrTypeOperatorCall -> first.argument.interpret().check { return@newFrame it }
-                else -> first.interpret().check { return@newFrame it }
-            }
+            // enum entry use IrTypeOperatorCall with IMPLICIT_COERCION_TO_UNIT as delegation call, but we need the value
+            ((statements[0] as? IrTypeOperatorCall)?.argument ?: statements[0]).interpret().check { return@newFrame it }
             val returnedState = stack.popReturnValue() as Complex
+
             for (i in 1 until statements.size) statements[i].interpret().check { return@newFrame it }
 
-            val state =
-                if (isPrimary) receiverState.apply { this.setSuperClassInstance(returnedState) }
-                else returnedState.apply { setStatesFrom(receiverState) } // if is secondary then only copy all properties from receiver
-
-            stack.pushReturnValue(state)
+            stack.pushReturnValue(state.apply { this.setSuperClassInstance(returnedState) })
             Next
         }
     }
diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/interpreter/state/Complex.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/interpreter/state/Complex.kt
index b93f69d125f..c7c30699da1 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/interpreter/state/Complex.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/interpreter/state/Complex.kt
@@ -17,8 +17,15 @@ abstract class Complex(
     override val irClass: IrClass, override val fields: MutableList<Variable>, var superClass: Complex?, var subClass: Complex?
 ) : State {
     fun setSuperClassInstance(superClass: Complex) {
-        this.superClass = superClass
-        superClass.subClass = this
+        if (this.irClass == superClass.irClass) {
+            // if superClass is just secondary constructor instance, then copy properties that isn't already present in instance
+            superClass.fields.forEach { if (!this.contains(it)) fields.add(it) }
+            this.superClass = superClass.superClass
+            superClass.superClass?.subClass = this
+        } else {
+            this.superClass = superClass
+            superClass.subClass = this
+        }
     }
 
     fun getOriginal(): Complex {
@@ -29,6 +36,8 @@ abstract class Complex(
         return irClass.fqNameForIrSerialization.toString()
     }
 
+    private fun contains(variable: Variable) = fields.any { it.descriptor == variable.descriptor }
+
     override fun setState(newVar: Variable) {
         when (val oldState = fields.firstOrNull { it.descriptor == newVar.descriptor }) {
             null -> fields.add(newVar)                          // newVar isn't present in value list
@@ -36,8 +45,6 @@ abstract class Complex(
         }
     }
 
-    fun setStatesFrom(state: Complex) = state.fields.forEach { setState(it) }
-
     override fun getIrFunction(descriptor: FunctionDescriptor): IrFunction? {
         val propertyGetters = irClass.declarations.filterIsInstance<IrProperty>().mapNotNull { it.getter }
         val functions = irClass.declarations.filterIsInstance<IrFunction>()