IR: IrTypeAlias: Strip 'typealias' declarations in back-ends

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

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.backend.common.lower
+
+import org.jetbrains.kotlin.backend.common.FileLoweringPass
+import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.declarations.IrClass
+import org.jetbrains.kotlin.ir.declarations.IrFile
+import org.jetbrains.kotlin.ir.declarations.IrTypeAlias
+import org.jetbrains.kotlin.ir.expressions.IrContainerExpression
+import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
+import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
+import org.jetbrains.kotlin.ir.visitors.acceptVoid
+
+class StripTypeAliasDeclarationsLowering :
+    IrElementVisitorVoid,
+    FileLoweringPass {
+
+    override fun lower(irFile: IrFile) {
+        irFile.acceptVoid(this)
+    }
+
+    override fun visitElement(element: IrElement) {
+        element.acceptChildrenVoid(this)
+    }
+
+    override fun visitFile(declaration: IrFile) {
+        declaration.acceptChildrenVoid(this)
+        declaration.declarations.removeAll { it is IrTypeAlias }
+    }
+
+    override fun visitClass(declaration: IrClass) {
+        declaration.acceptChildrenVoid(this)
+        declaration.declarations.removeAll { it is IrTypeAlias }
+    }
+
+    override fun visitContainerExpression(expression: IrContainerExpression) {
+        expression.acceptChildrenVoid(this)
+        expression.statements.removeAll { it is IrTypeAlias }
+    }
+}

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsLoweringPhases.kt

@@ -98,6 +98,12 @@ private val lateinitLoweringPhase = makeJsModulePhase(
     description = "Insert checks for lateinit field references"
 )
 
+private val stripTypeAliasDeclarationsPhase = makeJsModulePhase(
+    { StripTypeAliasDeclarationsLowering() },
+    name = "StripTypeAliasDeclarations",
+    description = "Strip typealias declarations"
+)
+
 // TODO make all lambda-related stuff work with IrFunctionExpression and drop this phase
 private val provisionalFunctionExpressionPhase = makeJsModulePhase(
     { ProvisionalFunctionExpressionLowering() },
@@ -396,6 +402,7 @@ val jsPhases = namedIrModulePhase(
     lower = validateIrBeforeLowering then
             testGenerationPhase then
             expectDeclarationsRemovingPhase then
+            stripTypeAliasDeclarationsPhase then
             provisionalFunctionExpressionPhase then
             arrayConstructorPhase then
             functionInliningPhase then

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmLower.kt

@@ -36,6 +36,12 @@ private fun makePatchParentsPhase(number: Int) = namedIrFilePhase(
     nlevels = 0
 )
 
+private val stripTypeAliasDeclarationsPhase = makeIrFilePhase<CommonBackendContext>(
+    { StripTypeAliasDeclarationsLowering() },
+    name = "StripTypeAliasDeclarations",
+    description = "Strip typealias declarations"
+)
+
 // TODO make all lambda-related stuff work with IrFunctionExpression and drop this phase
 private val provisionalFunctionExpressionPhase = makeIrFilePhase<CommonBackendContext>(
     { ProvisionalFunctionExpressionLowering() },
@@ -106,6 +112,7 @@ private val innerClassesPhase = makeIrFilePhase(
 )
 
 private val jvmFilePhases =
+        stripTypeAliasDeclarationsPhase then
         provisionalFunctionExpressionPhase then
         inventNamesForLocalClassesPhase then
         kCallableNamePropertyPhase then