Fixed KT-5315 J2K: Generate local var when parameter is being assigned

#KT-5315 Fixed

j2k/src/org/jetbrains/jet/j2k/Converter.kt

@@ -349,13 +349,35 @@ public class Converter private(val project: Project, val settings: ConverterSett
         val annotations = (convertAnnotations(method) + convertThrows(method)).assignNoPrototype()
         var modifiers = convertModifiers(method)
 
+        val statementsToInsert = ArrayList<Statement>()
+        for (parameter in method.getParameterList().getParameters()) {
+            if (parameter.hasWriteAccesses(method)) {
+                val variable = LocalVariable(parameter.declarationIdentifier(),
+                                             Annotations.Empty,
+                                             Modifiers.Empty,
+                                             null,
+                                             parameter.declarationIdentifier(),
+                                             false).assignNoPrototype()
+                statementsToInsert.add(DeclarationStatement(listOf(variable)).assignNoPrototype())
+            }
+        }
+        val postProcessBody: (Block) -> Block = { body ->
+            if (statementsToInsert.isEmpty()) {
+                body
+            }
+            else {
+                Block(statementsToInsert + body.statements, body.lBrace, body.rBrace).assignPrototypesFrom(body)
+            }
+        }
+
         if (method.isConstructor()) {
             if (method.isPrimaryConstructor()) {
-                return convertPrimaryConstructor(method, annotations, modifiers, membersToRemove)
+                return convertPrimaryConstructor(method, annotations, modifiers, membersToRemove, postProcessBody)
             }
             else {
                 val params = convertParameterList(method.getParameterList())
-                return SecondaryConstructor(this, annotations, modifiers, params, convertBlock(method.getBody()))
+                var body = postProcessBody(convertBlock(method.getBody()))
+                return SecondaryConstructor(this, annotations, modifiers, params, body)
             }
         }
         else {
@@ -376,8 +398,8 @@ public class Converter private(val project: Project, val settings: ConverterSett
 
             var params = convertParameterList(method.getParameterList())
             val typeParameterList = convertTypeParameterList(method.getTypeParameterList())
-            val block = convertBlock(method.getBody())
-            return Function(this, method.declarationIdentifier(), annotations, modifiers, returnType, typeParameterList, params, block, containingClass?.isInterface() ?: false)
+            var body = postProcessBody(convertBlock(method.getBody()))
+            return Function(this, method.declarationIdentifier(), annotations, modifiers, returnType, typeParameterList, params, body, containingClass?.isInterface() ?: false)
         }
     }
 
@@ -419,7 +441,8 @@ public class Converter private(val project: Project, val settings: ConverterSett
     private fun convertPrimaryConstructor(constructor: PsiMethod,
                                           annotations: Annotations,
                                           modifiers: Modifiers,
-                                          membersToRemove: MutableSet<PsiMember>): PrimaryConstructor {
+                                          membersToRemove: MutableSet<PsiMember>,
+                                          postProcessBody: (Block) -> Block): PrimaryConstructor {
         val params = constructor.getParameterList().getParameters()
         val parameterToField = HashMap<PsiParameter, Pair<PsiField, Type>>()
         val body = constructor.getBody()
@@ -451,7 +474,8 @@ public class Converter private(val project: Project, val settings: ConverterSett
                 }
             }
 
-            withExpressionVisitor { ExpressionVisitor(it, usageReplacementMap) }.convertBlock(body, false, { !statementsToRemove.contains(it) })
+            val correctedConverter = withExpressionVisitor { ExpressionVisitor(it, usageReplacementMap) }
+            postProcessBody(correctedConverter.convertBlock(body, false, { !statementsToRemove.contains(it) }))
         }
         else {
             Block.Empty

j2k/tests/test/org/jetbrains/jet/j2k/test/JavaToKotlinConverterTestGenerated.java

@@ -856,6 +856,11 @@ public class JavaToKotlinConverterTestGenerated extends AbstractJavaToKotlinConv
             doTest("j2k/tests/testData/ast/constructors/identifier.java");
         }
         
+        @TestMetadata("parameterModification.java")
+        public void testParameterModification() throws Exception {
+            doTest("j2k/tests/testData/ast/constructors/parameterModification.java");
+        }
+        
         @TestMetadata("privateConstructors.java")
         public void testPrivateConstructors() throws Exception {
             doTest("j2k/tests/testData/ast/constructors/privateConstructors.java");
@@ -1361,6 +1366,11 @@ public class JavaToKotlinConverterTestGenerated extends AbstractJavaToKotlinConv
             doTest("j2k/tests/testData/ast/function/ownSeveralGenericParams.java");
         }
         
+        @TestMetadata("parameterModification.java")
+        public void testParameterModification() throws Exception {
+            doTest("j2k/tests/testData/ast/function/parameterModification.java");
+        }
+        
         @TestMetadata("private.java")
         public void testPrivate() throws Exception {
             doTest("j2k/tests/testData/ast/function/private.java");
@@ -1386,11 +1396,6 @@ public class JavaToKotlinConverterTestGenerated extends AbstractJavaToKotlinConv
             doTest("j2k/tests/testData/ast/function/varVararg.java");
         }
         
-        @TestMetadata("writableParameter.java")
-        public void testWritableParameter() throws Exception {
-            doTest("j2k/tests/testData/ast/function/writableParameter.java");
-        }
-        
     }
     
     @TestMetadata("j2k/tests/testData/ast/identifier")

j2k/tests/testData/ast/constructors/fieldsInitializedFromParams3.kt

@@ -2,6 +2,7 @@ class C(p: Int) {
     private val p: Int
 
     {
+        var p = p
         this.p = p
         System.out.println(p++)
         System.out.println(p)

j2k/tests/testData/ast/constructors/parameterModification.java

@@ -0,0 +1,28 @@
+//file
+class C {
+    private val field;
+
+    C(int arg1, int arg2, int arg3) {
+        arg1++;
+        System.out.print(arg1 + arg2);
+        field = arg3;
+        arg3++;
+    }
+
+    C(int arg1, int arg2) {
+        this(arg1, arg2, 0);
+        arg2++;
+    }
+
+    C(int arg1) {
+        this(arg1, 0, 0);
+    }
+}
+
+public class User {
+    public static void main() {
+        C c1 = new C(100, 100, 100);
+        C c2 = new C(100, 100);
+        C c3 = new C(100);
+    }
+}

j2k/tests/testData/ast/constructors/parameterModification.kt

@@ -0,0 +1,37 @@
+class C(arg1: Int, arg2: Int, arg3: Int) {
+    private val field: `val`
+
+    {
+        var arg1 = arg1
+        var arg3 = arg3
+        arg1++
+        System.out.print(arg1 + arg2)
+        field = arg3
+        arg3++
+    }
+
+    class object {
+
+        fun create(arg1: Int, arg2: Int): C {
+            var arg2 = arg2
+            val __ = C(arg1, arg2, 0)
+            arg2++
+            return __
+        }
+
+        fun create(arg1: Int): C {
+            val __ = C(arg1, 0, 0)
+            return __
+        }
+    }
+}
+
+public class User() {
+    class object {
+        public fun main() {
+            val c1 = C(100, 100, 100)
+            val c2 = C.create(100, 100)
+            val c3 = C.create(100)
+        }
+    }
+}

j2k/tests/testData/ast/function/parameterModification.java

@@ -0,0 +1,6 @@
+//method
+int foo(int p1, int p2, int p3) {
+    p1++;
+    if (p2 > 0) p3 = 0;
+    return p1 + p2 + p3;
+}

j2k/tests/testData/ast/function/parameterModification.kt

@@ -0,0 +1,7 @@
+fun foo(p1: Int, p2: Int, p3: Int): Int {
+    var p1 = p1
+    var p3 = p3
+    p1++
+    if (p2 > 0) p3 = 0
+    return p1 + p2 + p3
+}

j2k/tests/testData/ast/function/varVararg.kt

@@ -2,6 +2,7 @@ package demo
 
 class Test() {
     fun test(vararg args: Any) {
+        var args = args
         args = array<Int>(1, 2, 3)
     }
 }

j2k/tests/testData/ast/function/writableParameter.java

@@ -1,9 +0,0 @@
-//file
-package demo;
-
-class Test {
-  int test(int i) {
-    i = 10;
-    return i + 20;
-  }
-}

j2k/tests/testData/ast/function/writableParameter.kt

@@ -1,8 +0,0 @@
-package demo
-
-class Test() {
-    fun test(i: Int): Int {
-        i = 10
-        return i + 20
-    }
-}