WASM: Lower expression bodies into block bodies

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

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2010-2021 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.CommonBackendContext
+import org.jetbrains.kotlin.backend.common.FileLoweringPass
+import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.builders.irReturn
+import org.jetbrains.kotlin.ir.declarations.IrFile
+import org.jetbrains.kotlin.ir.declarations.IrFunction
+import org.jetbrains.kotlin.ir.expressions.IrExpressionBody
+import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
+import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
+import org.jetbrains.kotlin.ir.visitors.acceptVoid
+
+// Replaces IrExpressionBody with IrBlockBody returning this expression.
+// Taken from kotlin/native ReturnsInsertionLowering.kt
+
+class ExpressionBodyTransformer(val context: CommonBackendContext) : FileLoweringPass {
+    override fun lower(irFile: IrFile) {
+        irFile.acceptVoid(object : IrElementVisitorVoid {
+            override fun visitElement(element: IrElement) {
+                element.acceptChildrenVoid(this)
+            }
+
+            override fun visitFunction(declaration: IrFunction) {
+                declaration.acceptChildrenVoid(this)
+
+                context.createIrBuilder(declaration.symbol, declaration.endOffset, declaration.endOffset).run {
+                    val body = declaration.body
+                    if (body is IrExpressionBody)
+                        declaration.body = context.irFactory.createBlockBody(body.startOffset, body.endOffset) {
+                            statements += irReturn(body.expression)
+                        }
+                }
+            }
+        })
+    }
+}

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

@@ -419,6 +419,12 @@ private val propertyAccessorInlinerLoweringPhase = makeWasmModulePhase(
     description = "[Optimization] Inline property accessors"
 )
 
+private val expressionBodyTransformer = makeWasmModulePhase(
+    ::ExpressionBodyTransformer,
+    name = "ExpressionBodyTransformer",
+    description = "Replace IrExpressionBody with IrBlockBody"
+)
+
 val wasmPhases = NamedCompilerPhase(
     name = "IrModuleLowering",
     description = "IR module lowering",
@@ -490,6 +496,7 @@ val wasmPhases = NamedCompilerPhase(
             objectDeclarationLoweringPhase then
             fieldInitializersLoweringPhase then
             genericReturnTypeLowering then
+            expressionBodyTransformer then
 
             // Replace builtins before autoboxing
             builtInsLoweringPhase0 then

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/ReturnsInsertionLowering.kt

@@ -22,28 +22,6 @@ import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
 import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
 import org.jetbrains.kotlin.ir.visitors.acceptVoid
 
-internal class ExpressionBodyTransformer(val context: Context) : FileLoweringPass {
-    override fun lower(irFile: IrFile) {
-        irFile.acceptVoid(object : IrElementVisitorVoid {
-            override fun visitElement(element: IrElement) {
-                element.acceptChildrenVoid(this)
-            }
-
-            override fun visitFunction(declaration: IrFunction) {
-                declaration.acceptChildrenVoid(this)
-
-                context.createIrBuilder(declaration.symbol, declaration.endOffset, declaration.endOffset).run {
-                    val body = declaration.body
-                    if (body is IrExpressionBody)
-                        declaration.body = IrBlockBodyImpl(body.startOffset, body.endOffset) {
-                            statements += irReturn(body.expression)
-                        }
-                }
-            }
-        })
-    }
-}
-
 internal class ReturnsInsertionLowering(val context: Context) : FileLoweringPass {
     private val symbols = context.ir.symbols