[Wasm] Fix unit issues

- Materialize unit when its value is actually needed.
- Special-case Unit_getInstance return type at codegen. It should be a
  proper Unit object instead of a "void"

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/InlineClassDeclarationLowering.kt

@@ -156,6 +156,8 @@ class InlineClassLowering(val context: CommonBackendContext) {
                         +statement.transformStatement(object : IrElementTransformerVoid() {
                             override fun visitDelegatingConstructorCall(expression: IrDelegatingConstructorCall): IrExpression {
                                 expression.transformChildrenVoid()
+                                // Static function for delegating constructors return unboxed instance of inline class
+                                expression.type = irClass.defaultType
                                 return irBlock(expression) {
                                     thisVar = createTmpVariable(
                                         expression,

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/AutoboxingTransformer.kt

@@ -7,13 +7,11 @@ package org.jetbrains.kotlin.ir.backend.js.lower
 
 import org.jetbrains.kotlin.backend.common.BodyLoweringPass
 import org.jetbrains.kotlin.backend.common.lower.AbstractValueUsageTransformer
+import org.jetbrains.kotlin.ir.IrBuiltIns
 import org.jetbrains.kotlin.ir.backend.js.JsCommonBackendContext
 import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
 import org.jetbrains.kotlin.ir.backend.js.utils.realOverrideTarget
-import org.jetbrains.kotlin.ir.declarations.IrDeclaration
+import org.jetbrains.kotlin.ir.declarations.*
-import org.jetbrains.kotlin.ir.declarations.IrDeclarationParent
-import org.jetbrains.kotlin.ir.declarations.IrFunction
-import org.jetbrains.kotlin.ir.declarations.IrValueParameter
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.isPrimitiveArray
@@ -126,7 +124,7 @@ class AutoboxingTransformer(context: JsCommonBackendContext) : AbstractValueUsag
 
         if (actualType.isUnit() && !expectedType.isUnit()) {
             // Don't materialize Unit if value is known to be proper Unit on runtime
-            if (!this.isGetUnit()) {
+            if (!this.isGetUnit(irBuiltIns)) {
                 val unitValue = JsIrBuilder.buildGetObjectValue(actualType, context.irBuiltIns.unitClass)
                 return JsIrBuilder.buildComposite(actualType, listOf(this, unitValue))
             }
@@ -160,20 +158,6 @@ class AutoboxingTransformer(context: JsCommonBackendContext) : AbstractValueUsag
         }
     }
 
-    private tailrec fun IrExpression.isGetUnit(): Boolean =
-        when (this) {
-            is IrContainerExpression ->
-                when (val lastStmt = this.statements.lastOrNull()) {
-                    is IrExpression -> lastStmt.isGetUnit()
-                    else -> false
-                }
-
-            is IrGetObjectValue ->
-                this.symbol == irBuiltIns.unitClass
-
-            else -> false
-        }
-
     private fun buildSafeCall(
         arg: IrExpression,
         actualType: IrType,
@@ -207,3 +191,32 @@ class AutoboxingTransformer(context: JsCommonBackendContext) : AbstractValueUsag
         }
     }
 }
+
+class UnitMaterializationPass(val context: JsCommonBackendContext) : AbstractValueUsageTransformer(context.irBuiltIns), BodyLoweringPass {
+    override fun lower(irBody: IrBody, container: IrDeclaration) {
+        irBody.transformChildrenVoid()
+    }
+
+    override fun IrExpression.useAsValue(value: IrValueDeclaration): IrExpression {
+        if (this.type == irBuiltIns.unitType && !this.isGetUnit(irBuiltIns)) {
+            val unitValue = JsIrBuilder.buildGetObjectValue(type, irBuiltIns.unitClass)
+            return JsIrBuilder.buildComposite(type, listOf(this, unitValue))
+        }
+        return this
+    }
+}
+
+
+private tailrec fun IrExpression.isGetUnit(irBuiltIns: IrBuiltIns): Boolean =
+    when (this) {
+        is IrContainerExpression ->
+            when (val lastStmt = this.statements.lastOrNull()) {
+                is IrExpression -> lastStmt.isGetUnit(irBuiltIns)
+                else -> false
+            }
+
+        is IrGetObjectValue ->
+            this.symbol == irBuiltIns.unitClass
+
+        else -> false
+    }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/misc.kt

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.backend.common.ir.isMethodOfAny
 import org.jetbrains.kotlin.backend.common.ir.isTopLevel
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
+import org.jetbrains.kotlin.ir.backend.js.JsCommonBackendContext
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.JsLoweredDeclarationOrigin
 import org.jetbrains.kotlin.ir.backend.js.export.isExported
@@ -115,6 +116,9 @@ fun IrBody.prependFunctionCall(
     }
 }
 
+fun JsCommonBackendContext.findUnitGetInstanceFunction(): IrSimpleFunction =
+    mapping.objectToGetInstanceFunction[irBuiltIns.unitClass.owner]!!
+
 fun IrDeclaration.isImportedFromModuleOnly(): Boolean {
     return isTopLevel && isEffectivelyExternal() && (getJsModule() != null && !isJsNonModule() || (parent as? IrAnnotationContainer)?.getJsModule() != null)
 }

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/WasmLoweringPhases.kt

@@ -328,6 +328,12 @@ private val wasmNullSpecializationLowering = makeWasmModulePhase(
     description = "Specialize assigning Nothing? values to other types."
 )
 
+private val unitMaterializationPass = makeWasmModulePhase(
+    { context -> UnitMaterializationPass(context) },
+    name = "UnitLoweringPass",
+    description = "Materialize unit instances"
+)
+
 private val staticMembersLoweringPhase = makeWasmModulePhase(
     ::StaticMembersLowering,
     name = "StaticMembersLowering",
@@ -499,5 +505,6 @@ val wasmPhases = NamedCompilerPhase(
             wasmThrowDebugLoweringPhase then
             staticMembersLoweringPhase then
             wasmNullSpecializationLowering then
+            unitMaterializationPass then
             validateIrAfterLowering
 )

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/BodyGenerator.kt

@@ -20,10 +20,7 @@ import org.jetbrains.kotlin.ir.backend.js.utils.realOverrideTarget
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.types.*
-import org.jetbrains.kotlin.ir.util.defaultType
+import org.jetbrains.kotlin.ir.util.*
-import org.jetbrains.kotlin.ir.util.getInlineClassBackingField
-import org.jetbrains.kotlin.ir.util.isInterface
-import org.jetbrains.kotlin.ir.util.parentAsClass
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
 import org.jetbrains.kotlin.ir.visitors.acceptVoid
 import org.jetbrains.kotlin.wasm.ir.*
@@ -40,6 +37,13 @@ class BodyGenerator(val context: WasmFunctionCodegenContext) : IrElementVisitorV
         error("Unexpected element of type ${element::class}")
     }
 
+    val unitGetInstance by lazy { backendContext.mapping.objectToGetInstanceFunction[irBuiltIns.unitClass.owner]!! }
+
+    override fun visitGetObjectValue(expression: IrGetObjectValue) {
+        require(expression.symbol == irBuiltIns.unitClass)
+        body.buildCall(context.referenceFunction(unitGetInstance.symbol))
+    }
+
     override fun visitTypeOperator(expression: IrTypeOperatorCall) {
         require(expression.operator == IrTypeOperator.REINTERPRET_CAST) { "Other types of casts must be lowered" }
         generateExpression(expression.argument)
@@ -329,11 +333,7 @@ class BodyGenerator(val context: WasmFunctionCodegenContext) : IrElementVisitorV
             statementToWasmInstruction(it)
         }
 
-        if (expression.type != irBuiltIns.unitType) {
+        generateExpression(statements.last() as IrExpression)
-            generateExpression(statements.last() as IrExpression)
-        } else {
-            statementToWasmInstruction(statements.last())
-        }
     }
 
     override fun visitBreak(jump: IrBreak) {
@@ -345,18 +345,17 @@ class BodyGenerator(val context: WasmFunctionCodegenContext) : IrElementVisitorV
     }
 
     override fun visitReturn(expression: IrReturn) {
-        generateExpression(expression.value)
+        if (
-
+            expression.value.type == irBuiltIns.unitType &&
-        // FIXME: Hack for "returning" Unit from functions with generic return type.
+            expression.returnTargetSymbol.owner.returnType(backendContext) == irBuiltIns.unitType
-        //        Common case -- lambdas returning unit.
-        if (expression.value.type == irBuiltIns.unitType &&
-            expression.returnTargetSymbol.owner.returnType(backendContext) != irBuiltIns.unitType
         ) {
-            val irReturnType = expression.returnTargetSymbol.owner.returnType(backendContext)
+            statementToWasmInstruction(expression.value)
+        } else {
+            generateExpression(expression.value)
+        }
 
-            if (irReturnType != irBuiltIns.unitType) {
+        if (context.irFunction is IrConstructor) {
-                generateDefaultInitializerForType(context.transformType(irReturnType), body)
+            body.buildGetLocal(context.referenceLocal(0))
-            }
         }
 
         // Handle complex exported parameters.
@@ -371,25 +370,6 @@ class BodyGenerator(val context: WasmFunctionCodegenContext) : IrElementVisitorV
     }
 
     override fun visitWhen(expression: IrWhen) {
-        if (expression.type == irBuiltIns.unitType) {
-            var ifCount = 0
-            for (branch in expression.branches) {
-                if (!isElseBranch(branch)) {
-                    generateExpression(branch.condition)
-                    body.buildIf(label = null, resultType = null)
-                    statementToWasmInstruction(branch.result)
-                    body.buildElse()
-                    ifCount++
-                } else {
-                    statementToWasmInstruction(branch.result)
-                    break
-                }
-            }
-
-            repeat(ifCount) { body.buildEnd() }
-            return
-        }
-
         val resultType = context.transformBlockResultType(expression.type)
         var ifCount = 0
         for (branch in expression.branches) {
@@ -489,10 +469,47 @@ class BodyGenerator(val context: WasmFunctionCodegenContext) : IrElementVisitorV
             return
         }
 
-        generateExpression(statement as IrExpression)
+        if (statement is IrContainerExpression) {
+            statement.statements.forEach { it ->
+                statementToWasmInstruction(it)
+            }
+        } else if (statement is IrWhen) {
+            var ifCount = 0
+            for (branch in statement.branches) {
+                if (!isElseBranch(branch)) {
+                    generateExpression(branch.condition)
+                    body.buildIf(label = null, resultType = null)
+                    statementToWasmInstruction(branch.result)
+                    body.buildElse()
+                    ifCount++
+                } else {
+                    statementToWasmInstruction(branch.result)
+                    break
+                }
+            }
 
-        if (statement.type != irBuiltIns.unitType && statement.type != irBuiltIns.nothingType) {
+            repeat(ifCount) { body.buildEnd() }
-            body.buildInstr(WasmOp.DROP)
+        } else {
+            generateExpression(statement as IrExpression)
+
+            var needDrop = true
+            if (statement.type == irBuiltIns.nothingType)
+                needDrop = false
+
+            if (statement is IrSetValue || statement is IrBreakContinue || statement is IrSetField || statement is IrLoop || statement is IrDelegatingConstructorCall) {
+                needDrop = false
+            }
+
+            if (statement is IrCall || statement is IrConstructorCall) {
+                val unitGetInstanceCall = statement is IrCall && statement.symbol.owner == unitGetInstance
+                if (statement.type == irBuiltIns.unitType && !unitGetInstanceCall) {
+                    needDrop = false
+                }
+            }
+
+            if (needDrop) {
+                body.buildInstr(WasmOp.DROP)
+            }
         }
     }
 

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/DeclarationGenerator.kt

@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.ir.IrBuiltIns
 import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.backend.js.utils.findUnitGetInstanceFunction
 import org.jetbrains.kotlin.ir.backend.js.utils.realOverrideTarget
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.IrBlockBody
@@ -29,6 +30,8 @@ class DeclarationGenerator(val context: WasmModuleCodegenContext) : IrElementVis
     private val backendContext: WasmBackendContext = context.backendContext
     private val irBuiltIns: IrBuiltIns = backendContext.irBuiltIns
 
+    private val unitGetInstanceFunction: IrSimpleFunction by lazy { backendContext.findUnitGetInstanceFunction() }
+
     override fun visitElement(element: IrElement) {
         error("Unexpected element of type ${element::class}")
     }
@@ -84,8 +87,18 @@ class DeclarationGenerator(val context: WasmModuleCodegenContext) : IrElementVis
                     }
                 },
                 resultTypes = listOfNotNull(
-                    resultType.let {
+                    run {
-                        if (importedName != null && it is WasmRefNullType) WasmEqRef else it
+                        val type = if (declaration == unitGetInstanceFunction) {
+                            // Unit_getInstance returns true Unit reference instead of "void"
+                            context.transformType(declaration.returnType)
+                        } else {
+                            resultType
+                        }
+
+                        if (importedName != null && type is WasmRefNullType)
+                            WasmEqRef
+                        else
+                            type
                     }
                 )
             )

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/lower/WasmTypeOperatorLowering.kt

@@ -14,9 +14,12 @@ import org.jetbrains.kotlin.backend.common.lower.createIrBuilder
 import org.jetbrains.kotlin.backend.common.lower.irNot
 import org.jetbrains.kotlin.backend.wasm.WasmBackendContext
 import org.jetbrains.kotlin.backend.wasm.ir2wasm.erasedUpperBound
+import org.jetbrains.kotlin.ir.IrStatement
+import org.jetbrains.kotlin.ir.backend.js.utils.findUnitGetInstanceFunction
 import org.jetbrains.kotlin.ir.builders.*
 import org.jetbrains.kotlin.ir.declarations.IrFile
 import org.jetbrains.kotlin.ir.declarations.IrTypeParameter
+import org.jetbrains.kotlin.ir.declarations.IrVariable
 import org.jetbrains.kotlin.ir.expressions.IrConst
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrTypeOperator
@@ -35,6 +38,7 @@ class WasmTypeOperatorLowering(val context: WasmBackendContext) : FileLoweringPa
 class WasmBaseTypeOperatorTransformer(val context: WasmBackendContext) : IrElementTransformerVoidWithContext() {
     private val symbols = context.wasmSymbols
     private val builtIns = context.irBuiltIns
+    private val unitGetInstance = context.findUnitGetInstanceFunction()
 
     private lateinit var builder: DeclarationIrBuilder
 
@@ -45,7 +49,7 @@ class WasmBaseTypeOperatorTransformer(val context: WasmBackendContext) : IrEleme
         return when (expression.operator) {
             IrTypeOperator.IMPLICIT_CAST -> lowerImplicitCast(expression)
             IrTypeOperator.IMPLICIT_DYNAMIC_CAST -> error("Dynamic casts are not supported in Wasm backend")
-            IrTypeOperator.IMPLICIT_COERCION_TO_UNIT -> expression.argument
+            IrTypeOperator.IMPLICIT_COERCION_TO_UNIT -> builder.irComposite(resultType = builtIns.unitType) { +expression.argument }
             IrTypeOperator.IMPLICIT_INTEGER_COERCION -> lowerIntegerCoercion(expression)
             IrTypeOperator.IMPLICIT_NOTNULL -> lowerImplicitCast(expression)
             IrTypeOperator.INSTANCEOF -> lowerInstanceOf(expression, inverted = false)
@@ -57,6 +61,19 @@ class WasmBaseTypeOperatorTransformer(val context: WasmBackendContext) : IrEleme
         }
     }
 
+    override fun visitVariable(declaration: IrVariable): IrStatement {
+        // Some IR passes, notable for-loops-lowering assumes implicit cast during variable initialization
+        val initializer = declaration.initializer
+        if (initializer != null &&
+            initializer.type != declaration.type
+        ) {
+            builder = context.createIrBuilder(currentScope!!.scope.scopeOwnerSymbol).at(declaration)
+            declaration.initializer = narrowType(initializer.type, declaration.type, initializer)
+        }
+
+        return super.visitVariable(declaration)
+    }
+
     private fun lowerInstanceOf(
         expression: IrTypeOperatorCall,
         inverted: Boolean
@@ -135,10 +152,7 @@ class WasmBaseTypeOperatorTransformer(val context: WasmBackendContext) : IrEleme
     private fun generateTypeCheckNonNull(argument: IrExpression, toType: IrType): IrExpression {
         assert(!toType.isMarkedNullable())
         return when {
-            toType.isNothing() -> builder.irComposite(resultType = builtIns.booleanType) {
+            toType.isNothing() -> builder.irFalse()
-                +(argument)
-                +builder.irFalse()
-            }
             toType.isTypeParameter() -> generateTypeCheckWithTypeParameter(argument, toType)
             toType.isInterface() -> generateIsInterface(argument, toType)
             else -> generateIsSubClass(argument, toType)
@@ -281,16 +295,10 @@ class WasmBaseTypeOperatorTransformer(val context: WasmBackendContext) : IrEleme
         val fromTypeErased = fromType.erasedType
         val toTypeErased = toType.erasedType
         if (fromTypeErased.isSubtypeOfClass(toTypeErased.classOrNull!!)) {
-            return builder.irComposite {
+            return builder.irTrue()
-                +argument
-                +builder.irTrue()
-            }
         }
         if (!toTypeErased.isSubtypeOfClass(fromTypeErased.classOrNull!!)) {
-            return builder.irComposite {
+            return builder.irFalse()
-                +argument
-                +builder.irFalse()
-            }
         }
 
         return builder.irCall(symbols.refTest).apply {

compiler/testData/codegen/box/arrays/forInReversed/reversedOriginalUpdatedInLoopBody.kt

@@ -1,5 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
+// WASM_MUTE_REASON: STDLIB_COLLECTIONS
 // KJS_WITH_FULL_RUNTIME
 // WITH_RUNTIME
 import kotlin.test.*

compiler/testData/codegen/box/arrays/forInReversed/reversedReversedOriginalUpdatedInLoopBody.kt

@@ -1,5 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
+// WASM_MUTE_REASON: STDLIB_COLLECTIONS
 // KJS_WITH_FULL_RUNTIME
 // WITH_RUNTIME
 import kotlin.test.*

compiler/testData/codegen/box/arrays/kt594.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 package array_test
 
 fun box() : String {

compiler/testData/codegen/box/arrays/nonLocalReturnArrayConstructor.kt

@@ -1,5 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
+// WASM_MUTE_REASON: INLINE_ARRAY_CONSTRUCTOR
 typealias ArrayS = Array<String>
 
 fun testArray() {

compiler/testData/codegen/box/casts/mutableCollections/asWithMutable.kt

@@ -1,5 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
+// WASM_MUTE_REASON: EXCEPTIONS_NOT_IMPLEMENTED
 // KJS_WITH_FULL_RUNTIME
 // WITH_RUNTIME
 

compiler/testData/codegen/box/casts/mutableCollections/reifiedAsWithMutable.kt

@@ -1,5 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
+// WASM_MUTE_REASON: EXCEPTIONS_NOT_IMPLEMENTED
 // KJS_WITH_FULL_RUNTIME
 // WITH_RUNTIME
 

compiler/testData/codegen/box/casts/unitAsAny.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 fun println(s: String) {
 }
 

compiler/testData/codegen/box/casts/unitAsSafeAny.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 fun println(s: String) {
 }
 

compiler/testData/codegen/box/casts/unitNullableCast.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 fun foo() {}
 
 fun bar(): Int? = foo() as? Int

compiler/testData/codegen/box/classes/kt1918.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 class Bar {
 }
 

compiler/testData/codegen/box/classes/overloadUnaryOperator.kt

@@ -1,5 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
+// WASM_MUTE_REASON: STDLIB_COLLECTIONS
 // KJS_WITH_FULL_RUNTIME
 // WITH_RUNTIME
 class ArrayWrapper<T>() {

compiler/testData/codegen/box/closures/capturedVarsOptimization/withCoroutinesNoStdLib.kt

@@ -1,5 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
+// WASM_MUTE_REASON: COROUTINES
 // WITH_RUNTIME
 // WITH_COROUTINES
 import helpers.*

compiler/testData/codegen/box/controlStructures/kt2597.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 fun box(): String {
     var i = 0
     {

compiler/testData/codegen/box/dataClasses/toString/unitComponent.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 data class A(val x: Unit)
 
 fun box(): String {

compiler/testData/codegen/box/dataClasses/unitComponent.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 data class A(val x: Unit)
 
 fun box(): String {

compiler/testData/codegen/box/diagnostics/functions/tailRecursion/tailCallInBlockInParentheses.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 // DONT_RUN_GENERATED_CODE: JS
 
 tailrec fun foo(x: Int) {

compiler/testData/codegen/box/functions/kt1649_2.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 interface A {
     val method : () -> Unit?
 }

compiler/testData/codegen/box/functions/kt3214.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 class A {
     fun get(vararg x: Int) = x.size
 }

compiler/testData/codegen/box/functions/localFunctions/localExtensionOnNullableParameter.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 open class T(var value: Int) {}
 
 fun localExtensionOnNullableParameter(): T {

compiler/testData/codegen/box/inference/coercionToUnitWithLastLambdaExpression.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 
 fun <T> myRun(action: () -> T): T = action()
 fun foo(): String = "foo"

compiler/testData/codegen/box/inference/noCoercionToUnitWithEqualityConstraintForNullableReturnType.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 
 class Inv<T>(val x: T?)
 

compiler/testData/codegen/box/inlineClasses/boxUnboxOfInlineClassForCapturedVars.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 // !LANGUAGE: +InlineClasses
 
 inline class UInt(private val value: Int) {

compiler/testData/codegen/box/ir/kt25405.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 fun <T> tableView(init: Table<T>.() -> Unit) {
     Table<T>().init()
 }

compiler/testData/codegen/box/ranges/forInProgressionWithIndex/forInWithIndexReversed.kt

@@ -1,5 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
+// WASM_MUTE_REASON: STDLIB_COLLECTIONS
 // KJS_WITH_FULL_RUNTIME
 // WITH_RUNTIME
 

compiler/testData/codegen/box/regressions/kt5953.kt

@@ -1,5 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
+// WASM_MUTE_REASON: STDLIB_COLLECTIONS
 // KJS_WITH_FULL_RUNTIME
 // WITH_RUNTIME
 

compiler/testData/codegen/box/secondaryConstructors/withNonLocalReturn.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 inline fun run2(block: () -> Unit) = block()
 
 class A {

compiler/testData/codegen/box/secondaryConstructors/withReturn.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 class A {
     val prop: Int
     constructor(arg: Boolean) {

compiler/testData/codegen/box/secondaryConstructors/withReturnUnit.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 class A {
     val prop: Int
     constructor(arg: Boolean) {

compiler/testData/codegen/box/unit/UnitValue.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 fun foo() {}
 
 fun box(): String {

compiler/testData/codegen/box/unit/closureReturnsNullableUnit.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 fun isNull(x: Unit?) = x == null
 
 fun box(): String {

compiler/testData/codegen/box/unit/kt3634.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 val c = Unit
 val d = c
 

compiler/testData/codegen/box/unit/kt4212.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 fun foo(): Any? = bar()
 
 fun bar() {}

compiler/testData/codegen/box/unit/kt4265.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 fun <T : Any, R> T.let(f: (T) -> R): R = f(this)
 
 fun box(): String {

compiler/testData/codegen/box/unit/nullableUnit.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 fun isNull(x: Unit?) = x == null
 
 fun <T : Any> isNullGeneric(x: T?) = x == null

compiler/testData/codegen/box/unit/nullableUnitInWhen3.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 fun foo() {}
 
 fun box(): String {

compiler/testData/codegen/box/unit/unitClassObject.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 fun box(): String {
     Unit
 

compiler/testData/codegen/box/when/noElseExhaustiveUnitExpected.kt

@@ -1,5 +1,3 @@
-// DONT_TARGET_EXACT_BACKEND: WASM
-// WASM_MUTE_REASON: UNIT_ISSUES
 enum class En {
     A,
     B

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/wasm/semantics/IrCodegenBoxWasmTestGenerated.java

@@ -458,6 +458,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/arrays/kt4357.kt");
         }
 
+        @TestMetadata("kt594.kt")
+        public void testKt594() throws Exception {
+            runTest("compiler/testData/codegen/box/arrays/kt594.kt");
+        }
+
         @TestMetadata("kt7009.kt")
         public void testKt7009() throws Exception {
             runTest("compiler/testData/codegen/box/arrays/kt7009.kt");
@@ -1971,6 +1976,21 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/casts/objectToPrimitiveWithAssertion.kt");
         }
 
+        @TestMetadata("unitAsAny.kt")
+        public void testUnitAsAny() throws Exception {
+            runTest("compiler/testData/codegen/box/casts/unitAsAny.kt");
+        }
+
+        @TestMetadata("unitAsSafeAny.kt")
+        public void testUnitAsSafeAny() throws Exception {
+            runTest("compiler/testData/codegen/box/casts/unitAsSafeAny.kt");
+        }
+
+        @TestMetadata("unitNullableCast.kt")
+        public void testUnitNullableCast() throws Exception {
+            runTest("compiler/testData/codegen/box/casts/unitNullableCast.kt");
+        }
+
         @TestMetadata("compiler/testData/codegen/box/casts/functions")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)
@@ -2284,6 +2304,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/classes/kt1891.kt");
         }
 
+        @TestMetadata("kt1918.kt")
+        public void testKt1918() throws Exception {
+            runTest("compiler/testData/codegen/box/classes/kt1918.kt");
+        }
+
         @TestMetadata("kt1976.kt")
         public void testKt1976() throws Exception {
             runTest("compiler/testData/codegen/box/classes/kt1976.kt");
@@ -3436,6 +3461,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/controlStructures/kt2416.kt");
         }
 
+        @TestMetadata("kt2597.kt")
+        public void testKt2597() throws Exception {
+            runTest("compiler/testData/codegen/box/controlStructures/kt2597.kt");
+        }
+
         @TestMetadata("kt299.kt")
         public void testKt299() throws Exception {
             runTest("compiler/testData/codegen/box/controlStructures/kt299.kt");
@@ -3840,6 +3870,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/dataClasses/twoVarParams.kt");
         }
 
+        @TestMetadata("unitComponent.kt")
+        public void testUnitComponent() throws Exception {
+            runTest("compiler/testData/codegen/box/dataClasses/unitComponent.kt");
+        }
+
         @TestMetadata("compiler/testData/codegen/box/dataClasses/copy")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)
@@ -4035,6 +4070,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             public void testMixedParams() throws Exception {
                 runTest("compiler/testData/codegen/box/dataClasses/toString/mixedParams.kt");
             }
+
+            @TestMetadata("unitComponent.kt")
+            public void testUnitComponent() throws Exception {
+                runTest("compiler/testData/codegen/box/dataClasses/toString/unitComponent.kt");
+            }
         }
     }
 
@@ -4780,6 +4820,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
                     runTest("compiler/testData/codegen/box/diagnostics/functions/tailRecursion/sum.kt");
                 }
 
+                @TestMetadata("tailCallInBlockInParentheses.kt")
+                public void testTailCallInBlockInParentheses() throws Exception {
+                    runTest("compiler/testData/codegen/box/diagnostics/functions/tailRecursion/tailCallInBlockInParentheses.kt");
+                }
+
                 @TestMetadata("tailCallInParentheses.kt")
                 public void testTailCallInParentheses() throws Exception {
                     runTest("compiler/testData/codegen/box/diagnostics/functions/tailRecursion/tailCallInParentheses.kt");
@@ -5809,6 +5854,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/functions/kt1649_1.kt");
         }
 
+        @TestMetadata("kt1649_2.kt")
+        public void testKt1649_2() throws Exception {
+            runTest("compiler/testData/codegen/box/functions/kt1649_2.kt");
+        }
+
         @TestMetadata("kt2270.kt")
         public void testKt2270() throws Exception {
             runTest("compiler/testData/codegen/box/functions/kt2270.kt");
@@ -5844,6 +5894,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/functions/kt2929.kt");
         }
 
+        @TestMetadata("kt3214.kt")
+        public void testKt3214() throws Exception {
+            runTest("compiler/testData/codegen/box/functions/kt3214.kt");
+        }
+
         @TestMetadata("kt3313.kt")
         public void testKt3313() throws Exception {
             runTest("compiler/testData/codegen/box/functions/kt3313.kt");
@@ -6155,6 +6210,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
                 runTest("compiler/testData/codegen/box/functions/localFunctions/kt4989.kt");
             }
 
+            @TestMetadata("localExtensionOnNullableParameter.kt")
+            public void testLocalExtensionOnNullableParameter() throws Exception {
+                runTest("compiler/testData/codegen/box/functions/localFunctions/localExtensionOnNullableParameter.kt");
+            }
+
             @TestMetadata("localFunctionInConstructor.kt")
             public void testLocalFunctionInConstructor() throws Exception {
                 runTest("compiler/testData/codegen/box/functions/localFunctions/localFunctionInConstructor.kt");
@@ -6578,6 +6638,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/inference/capturedTypesSubstitutionIntoAbbreviation.kt");
         }
 
+        @TestMetadata("coercionToUnitWithLastLambdaExpression.kt")
+        public void testCoercionToUnitWithLastLambdaExpression() throws Exception {
+            runTest("compiler/testData/codegen/box/inference/coercionToUnitWithLastLambdaExpression.kt");
+        }
+
         @TestMetadata("earlyReturnInsideCrossinlineLambda.kt")
         public void testEarlyReturnInsideCrossinlineLambda() throws Exception {
             runTest("compiler/testData/codegen/box/inference/earlyReturnInsideCrossinlineLambda.kt");
@@ -6633,6 +6698,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/inference/noCoercionToUniForNullableLambdaReturnType.kt");
         }
 
+        @TestMetadata("noCoercionToUnitWithEqualityConstraintForNullableReturnType.kt")
+        public void testNoCoercionToUnitWithEqualityConstraintForNullableReturnType() throws Exception {
+            runTest("compiler/testData/codegen/box/inference/noCoercionToUnitWithEqualityConstraintForNullableReturnType.kt");
+        }
+
         @TestMetadata("recursiveConstraintInsideTypeArgumentWithStarProjection.kt")
         public void testRecursiveConstraintInsideTypeArgumentWithStarProjection() throws Exception {
             runTest("compiler/testData/codegen/box/inference/recursiveConstraintInsideTypeArgumentWithStarProjection.kt");
@@ -6792,6 +6862,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/inlineClasses/boxResultInlineClassOfConstructorCall.kt");
         }
 
+        @TestMetadata("boxUnboxOfInlineClassForCapturedVars.kt")
+        public void testBoxUnboxOfInlineClassForCapturedVars() throws Exception {
+            runTest("compiler/testData/codegen/box/inlineClasses/boxUnboxOfInlineClassForCapturedVars.kt");
+        }
+
         @TestMetadata("bridgeForFunctionReturningInlineClass.kt")
         public void testBridgeForFunctionReturningInlineClass() throws Exception {
             runTest("compiler/testData/codegen/box/inlineClasses/bridgeForFunctionReturningInlineClass.kt");
@@ -9076,6 +9151,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/ir/hashCodeOnGenericSubstitutedWithPrimitive.kt");
         }
 
+        @TestMetadata("kt25405.kt")
+        public void testKt25405() throws Exception {
+            runTest("compiler/testData/codegen/box/ir/kt25405.kt");
+        }
+
         @TestMetadata("kt40083.kt")
         public void testKt40083() throws Exception {
             runTest("compiler/testData/codegen/box/ir/kt40083.kt");
@@ -14626,6 +14706,21 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/secondaryConstructors/varargs.kt");
         }
 
+        @TestMetadata("withNonLocalReturn.kt")
+        public void testWithNonLocalReturn() throws Exception {
+            runTest("compiler/testData/codegen/box/secondaryConstructors/withNonLocalReturn.kt");
+        }
+
+        @TestMetadata("withReturn.kt")
+        public void testWithReturn() throws Exception {
+            runTest("compiler/testData/codegen/box/secondaryConstructors/withReturn.kt");
+        }
+
+        @TestMetadata("withReturnUnit.kt")
+        public void testWithReturnUnit() throws Exception {
+            runTest("compiler/testData/codegen/box/secondaryConstructors/withReturnUnit.kt");
+        }
+
         @TestMetadata("withoutPrimarySimple.kt")
         public void testWithoutPrimarySimple() throws Exception {
             runTest("compiler/testData/codegen/box/secondaryConstructors/withoutPrimarySimple.kt");
@@ -15955,11 +16050,36 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/unit"), Pattern.compile("^([^_](.+))\\.kt$"), null, TargetBackend.WASM, true);
         }
 
+        @TestMetadata("closureReturnsNullableUnit.kt")
+        public void testClosureReturnsNullableUnit() throws Exception {
+            runTest("compiler/testData/codegen/box/unit/closureReturnsNullableUnit.kt");
+        }
+
         @TestMetadata("ifElse.kt")
         public void testIfElse() throws Exception {
             runTest("compiler/testData/codegen/box/unit/ifElse.kt");
         }
 
+        @TestMetadata("kt3634.kt")
+        public void testKt3634() throws Exception {
+            runTest("compiler/testData/codegen/box/unit/kt3634.kt");
+        }
+
+        @TestMetadata("kt4212.kt")
+        public void testKt4212() throws Exception {
+            runTest("compiler/testData/codegen/box/unit/kt4212.kt");
+        }
+
+        @TestMetadata("kt4265.kt")
+        public void testKt4265() throws Exception {
+            runTest("compiler/testData/codegen/box/unit/kt4265.kt");
+        }
+
+        @TestMetadata("nullableUnit.kt")
+        public void testNullableUnit() throws Exception {
+            runTest("compiler/testData/codegen/box/unit/nullableUnit.kt");
+        }
+
         @TestMetadata("nullableUnitInWhen1.kt")
         public void testNullableUnitInWhen1() throws Exception {
             runTest("compiler/testData/codegen/box/unit/nullableUnitInWhen1.kt");
@@ -15969,6 +16089,21 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
         public void testNullableUnitInWhen2() throws Exception {
             runTest("compiler/testData/codegen/box/unit/nullableUnitInWhen2.kt");
         }
+
+        @TestMetadata("nullableUnitInWhen3.kt")
+        public void testNullableUnitInWhen3() throws Exception {
+            runTest("compiler/testData/codegen/box/unit/nullableUnitInWhen3.kt");
+        }
+
+        @TestMetadata("unitClassObject.kt")
+        public void testUnitClassObject() throws Exception {
+            runTest("compiler/testData/codegen/box/unit/unitClassObject.kt");
+        }
+
+        @TestMetadata("UnitValue.kt")
+        public void testUnitValue() throws Exception {
+            runTest("compiler/testData/codegen/box/unit/UnitValue.kt");
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/unsignedTypes")
@@ -16330,6 +16465,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/when/noElseExhaustiveStatement.kt");
         }
 
+        @TestMetadata("noElseExhaustiveUnitExpected.kt")
+        public void testNoElseExhaustiveUnitExpected() throws Exception {
+            runTest("compiler/testData/codegen/box/when/noElseExhaustiveUnitExpected.kt");
+        }
+
         @TestMetadata("noElseInStatement.kt")
         public void testNoElseInStatement() throws Exception {
             runTest("compiler/testData/codegen/box/when/noElseInStatement.kt");