New J2K: Add support of Java static init declarations

nj2k/src/org/jetbrains/kotlin/nj2k/ConversionsRunner.kt

@@ -48,6 +48,7 @@ object ConversionsRunner {
             +SynchronizedStatementConversion(context)
             +DefaultArgumentsConversion(context)
             +ConstructorConversion(context)
+            +StaticInitDeclarationConversion()
             +ImplicitInitializerConversion(context)
             +ParameterModificationInMethodCallsConversion(context)
             +PrintlnConversion(context)

nj2k/src/org/jetbrains/kotlin/nj2k/JavaToJKTreeBuilder.kt

@@ -446,8 +446,11 @@ class JavaToJKTreeBuilder(
                 }
             )
 
-        fun PsiClassInitializer.toJK() =
-            JKKtInitDeclarationImpl(body.toJK())
+        fun PsiClassInitializer.toJK(): JKDeclaration =
+            if (hasModifier(JvmModifier.STATIC))
+                JKJavaStaticInitDeclarationImpl(body.toJK())
+            else JKKtInitDeclarationImpl(body.toJK())
+
 
         fun PsiEnumConstant.toJK(): JKEnumConstant =
             JKEnumConstantImpl(

nj2k/src/org/jetbrains/kotlin/nj2k/conversions/StaticInitDeclarationConversion.kt

@@ -0,0 +1,40 @@
+/*
+ * 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.nj2k.conversions
+
+import org.jetbrains.kotlin.nj2k.createCompanion
+import org.jetbrains.kotlin.nj2k.getCompanion
+import org.jetbrains.kotlin.nj2k.replace
+import org.jetbrains.kotlin.nj2k.tree.JKClass
+import org.jetbrains.kotlin.nj2k.tree.JKJavaStaticInitDeclaration
+import org.jetbrains.kotlin.nj2k.tree.JKTreeElement
+import org.jetbrains.kotlin.nj2k.tree.detached
+import org.jetbrains.kotlin.nj2k.tree.impl.JKKtInitDeclarationImpl
+
+class StaticInitDeclarationConversion : RecursiveApplicableConversionBase() {
+    override fun applyToElement(element: JKTreeElement): JKTreeElement {
+        if (element !is JKClass) return recurse(element)
+        val staticInitDeclarations =
+            element.classBody.declarations.filterIsInstance<JKJavaStaticInitDeclaration>()
+        if (staticInitDeclarations.isEmpty()) return recurse(element)
+        val companion = element.getCompanion()
+        if (companion == null) {
+            element.classBody.declarations = element.classBody.declarations.replace(
+                staticInitDeclarations.first(),
+                createCompanion(staticInitDeclarations.map { it.toKtInitDeclaration() })
+            )
+            element.classBody.declarations -= staticInitDeclarations.drop(1)
+        } else {
+            companion.classBody.declarations += staticInitDeclarations.map { it.toKtInitDeclaration() }
+            element.classBody.declarations -= staticInitDeclarations
+        }
+
+        return recurse(element)
+    }
+
+    private fun JKJavaStaticInitDeclaration.toKtInitDeclaration() =
+        JKKtInitDeclarationImpl(::block.detached())
+}

nj2k/src/org/jetbrains/kotlin/nj2k/tree/impl/j.kt

@@ -414,3 +414,7 @@ class JKKtAnnotationArrayInitializerExpressionImpl(initializers: List<JKAnnotati
 
     override fun <R, D> accept(visitor: JKVisitor<R, D>, data: D): R = visitor.visitKtAnnotationArrayInitializerExpression(this, data)
 }
+class JKJavaStaticInitDeclarationImpl(block: JKBlock) : JKJavaStaticInitDeclaration, JKBranchElementBase() {
+    override var block: JKBlock by child(block)
+    override fun <R, D> accept(visitor: JKVisitor<R, D>, data: D): R = visitor.visitJavaStaticInitDeclaration(this, data)
+}

nj2k/src/org/jetbrains/kotlin/nj2k/tree/j.kt

@@ -136,4 +136,8 @@ interface JKJavaSynchronizedStatement : JKStatement, JKBranchElement {
 
 interface JKJavaAnnotationMethod : JKMethod, JKBranchElement {
     val defaultValue: JKAnnotationMemberValue
+}
+
+interface JKJavaStaticInitDeclaration : JKDeclaration, JKBranchElement {
+    var block: JKBlock
 }

nj2k/src/org/jetbrains/kotlin/nj2k/utils.kt

@@ -0,0 +1,13 @@
+/*
+ * 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.nj2k
+
+fun <T> List<T>.replace(element: T, replacer: T): List<T> {
+    val mutableList = toMutableList()
+    val index = indexOf(element)
+    mutableList[index] = replacer
+    return mutableList
+}