From 51bb548aefc5a536dfaa540357964eb4fbd0391c Mon Sep 17 00:00:00 2001
From: Artem Kobzar <artem.kobzar@jetbrains.com>
Date: Tue, 22 Mar 2022 10:02:21 +0000
Subject: [PATCH] fix: remove unusedUnit_getInstance calls.

---
 .../irToJs/IrElementToJsStatementTransformer.kt       | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrElementToJsStatementTransformer.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrElementToJsStatementTransformer.kt
index e3db9df5509..9d11e6903f1 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrElementToJsStatementTransformer.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrElementToJsStatementTransformer.kt
@@ -7,12 +7,15 @@ package org.jetbrains.kotlin.ir.backend.js.transformers.irToJs
 
 import org.jetbrains.kotlin.ir.backend.js.utils.isTheLastReturnStatementIn
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
+import org.jetbrains.kotlin.ir.backend.js.JsLoweredDeclarationOrigin
 import org.jetbrains.kotlin.ir.backend.js.utils.JsGenerationContext
 import org.jetbrains.kotlin.ir.backend.js.utils.emptyScope
 import org.jetbrains.kotlin.ir.declarations.IrFunction
 import org.jetbrains.kotlin.ir.declarations.IrVariable
 import org.jetbrains.kotlin.ir.expressions.*
+import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
 import org.jetbrains.kotlin.ir.symbols.IrReturnableBlockSymbol
+import org.jetbrains.kotlin.ir.types.classifierOrNull
 import org.jetbrains.kotlin.ir.types.isAny
 import org.jetbrains.kotlin.ir.util.constructedClassType
 import org.jetbrains.kotlin.ir.util.file
@@ -137,12 +140,20 @@ class IrElementToJsStatementTransformer : BaseIrElementToJsNodeTransformer<JsSta
     }
 
     override fun visitCall(expression: IrCall, data: JsGenerationContext): JsStatement {
+        if (expression.symbol.isUnitInstanceFunction(data)) {
+            return JsEmpty
+        }
         if (data.checkIfJsCode(expression.symbol) || data.checkIfAnnotatedWithJsFunc(expression.symbol)) {
             return JsCallTransformer(expression, data).generateStatement()
         }
         return translateCall(expression, data, IrElementToJsExpressionTransformer()).withSource(expression, data).makeStmt()
     }
 
+    private fun IrFunctionSymbol.isUnitInstanceFunction(context: JsGenerationContext): Boolean {
+        return owner.origin === JsLoweredDeclarationOrigin.OBJECT_GET_INSTANCE_FUNCTION &&
+                owner.returnType.classifierOrNull === context.staticContext.backendContext.irBuiltIns.unitClass
+    }
+
     override fun visitInstanceInitializerCall(expression: IrInstanceInitializerCall, context: JsGenerationContext): JsStatement {
 
         // TODO: implement