[JS IR BE] Static members lowering pass

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

@@ -339,6 +339,13 @@ private val testGenerationPhase = makeJsModulePhase(
     description = "Generate invocations to kotlin.test suite and test functions"
 )
 
+private val staticMembersLoweringPhase = makeJsModulePhase(
+    ::StaticMembersLowering,
+    name = "StaticMembersLowering",
+    description = "Move static member declarations to top-level"
+)
+
+
 val jsPhases = namedIrModulePhase(
     name = "IrModuleLowering",
     description = "IR module lowering",
@@ -382,5 +389,6 @@ val jsPhases = namedIrModulePhase(
             blockDecomposerLoweringPhase then
             primitiveCompanionLoweringPhase then
             constLoweringPhase then
-            callsLoweringPhase
+            callsLoweringPhase then
+            staticMembersLoweringPhase
 )

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

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. 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.ir.backend.js.lower
+
+import org.jetbrains.kotlin.backend.common.FileLoweringPass
+import org.jetbrains.kotlin.backend.common.ir.addChild
+import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
+import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.util.getPackageFragment
+import org.jetbrains.kotlin.ir.util.isEffectivelyExternal
+import org.jetbrains.kotlin.ir.util.parentAsClass
+import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
+import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
+
+// Move static member declarations from classes to top level
+class StaticMembersLowering(val context: JsIrBackendContext) : FileLoweringPass {
+
+    override fun lower(irFile: IrFile) {
+        val staticDeclarationsInClasses = mutableListOf<IrDeclaration>()
+        irFile.acceptChildrenVoid(object : IrElementVisitorVoid {
+            override fun visitElement(element: IrElement) {
+                element.acceptChildrenVoid(this)
+            }
+
+            override fun visitClass(declaration: IrClass) {
+                if (declaration.parent is IrClass && !declaration.isEffectivelyExternal())
+                    staticDeclarationsInClasses.add(declaration)
+                super.visitClass(declaration)
+            }
+
+            override fun visitSimpleFunction(declaration: IrSimpleFunction) {
+                if (declaration.parent is IrClass && declaration.isStaticMethodOfClass && !declaration.isEffectivelyExternal())
+                    staticDeclarationsInClasses.add(declaration)
+                super.visitSimpleFunction(declaration)
+            }
+        })
+
+        for (declaration in staticDeclarationsInClasses) {
+            val klass = declaration.parentAsClass
+            val fragment = klass.getPackageFragment()!!
+            klass.declarations.remove(declaration)
+            fragment.addChild(declaration)
+            declaration.parent = fragment
+        }
+    }
+}