J2K: replace overloads with optional parameters not only for constructors but for methods too

j2k/src/org/jetbrains/kotlin/j2k/ClassBodyConverter.kt

@@ -49,8 +49,12 @@ class ClassBodyConverter(private val psiClass: PsiClass,
     public fun convertBody(): ClassBody {
         processAccessorsToDrop()
 
+        val overloadReducer = OverloadReducer(psiClass.getMethods().filter { it !in membersToRemove } /* do not allow OverloadReducer to use accessors converted to properties */,
+                                              isOpenClass,
+                                              converter.referenceSearcher)
+
         val constructorConverter = if (psiClass.getName() != null && !isObject)
-            ConstructorConverter(psiClass, converter, fieldCorrections)
+            ConstructorConverter(psiClass, converter, fieldCorrections, overloadReducer)
         else
             null
 
@@ -59,8 +63,9 @@ class ClassBodyConverter(private val psiClass: PsiClass,
             if (element is PsiMember) {
                 if (element is PsiAnnotationMethod) continue // converted in convertAnnotationType()
                 if (isObject && element.isConstructor()) continue // no constructor in object
+                if (element is PsiMethod && overloadReducer.shouldDropMethod(element)) continue
 
-                val converted = converter.convertMember(element, membersToRemove, constructorConverter)
+                val converted = converter.convertMember(element, membersToRemove, constructorConverter, overloadReducer)
                 if (converted != null) {
                     convertedMembers.put(element, converted)
                 }
@@ -88,7 +93,7 @@ class ClassBodyConverter(private val psiClass: PsiClass,
                 }
             }
 
-            return ClassBody(null, null, convertedMembers.values().toList(), emptyList(), lBrace, rBrace)
+            return ClassBody(null, null, convertedMembers.values().toList(), emptyList(), lBrace, rBrace, overloadReducer)
         }
 
         val useCompanionObject = shouldGenerateCompanionObject(convertedMembers)
@@ -123,14 +128,15 @@ class ClassBodyConverter(private val psiClass: PsiClass,
             primaryConstructorSignature = null // no "()" after class name is needed in this case
         }
 
-        return ClassBody(primaryConstructorSignature, constructorConverter?.baseClassParams, members, companionObjectMembers, lBrace, rBrace)
+        return ClassBody(primaryConstructorSignature, constructorConverter?.baseClassParams, members, companionObjectMembers, lBrace, rBrace, overloadReducer)
     }
 
     private fun Converter.convertMember(member: PsiMember,
                                         membersToRemove: MutableSet<PsiMember>,
-                                        constructorConverter: ConstructorConverter?): Member? {
+                                        constructorConverter: ConstructorConverter?,
+                                        overloadReducer: OverloadReducer): Member? {
         return when (member) {
-            is PsiMethod -> convertMethod(member, membersToRemove, constructorConverter, isOpenClass)
+            is PsiMethod -> convertMethod(member, membersToRemove, constructorConverter, overloadReducer, isOpenClass)
             is PsiField -> convertField(member, fieldCorrections[member])
             is PsiClass -> convertClass(member)
             is PsiClassInitializer -> convertInitializer(member)

j2k/src/org/jetbrains/kotlin/j2k/ConstructorConverter.kt

@@ -27,9 +27,10 @@ import java.util.HashSet
 class ConstructorConverter(
         private val psiClass: PsiClass,
         private val converter: Converter,
-        private val fieldCorrections: Map<PsiField, FieldCorrectionInfo>
+        private val fieldCorrections: Map<PsiField, FieldCorrectionInfo>,
+        private val overloadReducer: OverloadReducer
 ) {
-    private val constructors = psiClass.getConstructors()
+    private val constructors = psiClass.getConstructors().asList()
 
     private val toTargetConstructorMap = buildToTargetConstructorMap()
 
@@ -43,29 +44,12 @@ class ConstructorConverter(
         val candidates = constructors.filter { it !in toTargetConstructorMap }
         if (candidates.size() != 1) return null // there should be only one constructor which does not call other constructor
         val primary = candidates.single()
-        if (toTargetConstructorMap.values().any() { it.constructor != primary }) return null // all other constructors call our candidate (directly or indirectly)
+        if (toTargetConstructorMap.values().any() { it != primary }) return null // all other constructors call our candidate (directly or indirectly)
         return primary
     }
 
-    private class TargetConstructorInfo(
+    private fun buildToTargetConstructorMap(): Map<PsiMethod, PsiMethod> {
-            /**
+        val toTargetConstructorMap = HashMap<PsiMethod, PsiMethod>()
-             * Target constructor (one which is finally invoked by this one)
-             */
-            val constructor: PsiMethod,
-            /**
-             * Is not null if this constructor is equivalent to the target constructor with a few last parameters having default values
-             */
-            val parameterDefaults: List<PsiExpression>?)
-
-    private val constructorsToDrop = HashSet<PsiMethod>()
-    private val lastParamDefaults = HashMap<PsiMethod, ArrayList<PsiExpression>>() // defaults for a few last parameters in reverse order
-
-    init {
-        dropConstructorsForDefaultValues()
-    }
-
-    private fun buildToTargetConstructorMap(): Map<PsiMethod, TargetConstructorInfo> {
-        val toTargetConstructorMap = HashMap<PsiMethod, TargetConstructorInfo>()
         for (constructor in constructors) {
             val firstStatement = constructor.getBody()?.getStatements()?.firstOrNull()
             val methodCall = (firstStatement as? PsiExpressionStatement)?.getExpression() as? PsiMethodCallExpression
@@ -74,25 +58,11 @@ class ConstructorConverter(
                 if (refExpr.getCanonicalText() == "this") {
                     val target = refExpr.resolve() as? PsiMethod
                     if (target != null && target.isConstructor()) {
-                        var parameterDefaults = calcTargetParameterDefaults(constructor, target, methodCall)
+                        val finalTarget = toTargetConstructorMap[target] ?: target
-
+                        toTargetConstructorMap[constructor] = finalTarget
-                        val finalTargetInfo = toTargetConstructorMap[target]
-                        if (finalTargetInfo != null && parameterDefaults != null) {
-                            parameterDefaults = if (finalTargetInfo.parameterDefaults != null)
-                                parameterDefaults!! + finalTargetInfo.parameterDefaults
-                            else
-                                null
-                        }
-                        val finalTarget = finalTargetInfo?.constructor ?: target
-
-                        toTargetConstructorMap[constructor] = TargetConstructorInfo(finalTarget, parameterDefaults)
                         for (entry in toTargetConstructorMap.entrySet()) {
-                            if (entry.value.constructor == constructor) {
+                            if (entry.value == constructor) {
-                                val newParameterDefaults = if (parameterDefaults != null)
+                                entry.setValue(finalTarget)
-                                    entry.value.parameterDefaults?.plus(parameterDefaults!!)
-                                else
-                                    null
-                                entry.setValue(TargetConstructorInfo(finalTarget, newParameterDefaults))
                             }
                         }
                     }
@@ -102,61 +72,6 @@ class ConstructorConverter(
         return toTargetConstructorMap
     }
 
-    private fun calcTargetParameterDefaults(constructor: PsiMethod, target: PsiMethod, targetCall: PsiMethodCallExpression): List<PsiExpression>? {
-        if (constructor.getBody()!!.getStatements().size() != 1) return null // constructor's body should consist of only "this(...)"
-        val parameters = constructor.getParameterList().getParameters()
-        val targetParameters = target.getParameterList().getParameters()
-        if (parameters.size() >= targetParameters.size()) return null
-        val args = targetCall.getArgumentList().getExpressions()
-        if (args.size() != targetParameters.size()) return null // incorrect code
-
-        for (i in parameters.indices) {
-            val parameter = parameters[i]
-            val targetParameter = targetParameters[i]
-            if (parameter.getName() != targetParameter.getName() || parameter.getType() != targetParameter.getType()) return null
-            val arg = args[i]
-            if (arg !is PsiReferenceExpression || arg.resolve() != parameter) return null
-        }
-
-        return args.drop(parameters.size())
-    }
-
-    private fun dropConstructorsForDefaultValues() {
-        val dropCandidates = toTargetConstructorMap
-                .filter {
-                    it.value.parameterDefaults != null
-                        && it.key.accessModifier() == it.value.constructor.accessModifier()
-                        && it.key.getModifierList().getAnnotations().isEmpty() /* do not drop constructors with annotations */
-                }
-                .map { it.key }
-                .sortBy { -it.getParameterList().getParametersCount() } // we will try to drop them starting from ones with more parameters
-
-        @DropCandidatesLoop
-        for (constructor in dropCandidates) {
-            val paramCount = constructor.getParameterList().getParametersCount()
-            val targetInfo = toTargetConstructorMap[constructor]!!
-            val targetConstructor = targetInfo.constructor
-            val targetParamCount = targetConstructor.getParameterList().getParametersCount()
-            assert(paramCount < targetParamCount)
-            val defaults = targetInfo.parameterDefaults!!
-            assert(defaults.size() == targetParamCount - paramCount)
-
-            val targetDefaults = lastParamDefaults.getOrPut(targetConstructor, { ArrayList() })
-
-            for (i in defaults.indices) {
-                val default = defaults[defaults.size() - i - 1]
-                if (i < targetDefaults.size()) { // default for this parameter has already been assigned
-                    if (targetDefaults[i].getText() != default.getText()) continue@DropCandidatesLoop
-                }
-                else {
-                    targetDefaults.add(default)
-                }
-            }
-
-            constructorsToDrop.add(constructor)
-        }
-    }
-
     public var baseClassParams: List<DeferredElement<Expression>>? = if (constructors.isEmpty()) emptyList() else null
         private set
 
@@ -169,10 +84,9 @@ class ConstructorConverter(
             convertPrimaryConstructor(annotations, modifiers, membersToRemove, postProcessBody)
         }
         else {
-            if (constructor in constructorsToDrop) return null
+            if (overloadReducer.shouldDropMethod(constructor)) return null
 
-            val params = convertParameterList(constructor, converter,
+            val params = converter.convertParameterList(constructor, overloadReducer)
-                                              { parameter, default -> converter.convertParameter(parameter, defaultValue = default) })
 
             val thisOrSuper = findThisOrSuperCall(constructor)
             val thisOrSuperDeferred = if (thisOrSuper != null)
@@ -193,14 +107,6 @@ class ConstructorConverter(
 
             SecondaryConstructor(annotations, modifiers, params, converter.deferredElement(::convertBody), thisOrSuperDeferred)
         }
-
-        if (result.parameterList.parameters.any { it.defaultValue != null }) {
-            result.annotations += Annotations(listOf(Annotation(Identifier("overloads").assignNoPrototype(),
-                                                                listOf(),
-                                                                brackets = result is PrimaryConstructor,
-                                                                newLineAfter = false).assignNoPrototype())).assignNoPrototype()
-        }
-
         return result
     }
 
@@ -288,53 +194,34 @@ class ConstructorConverter(
             baseClassParams = emptyList()
         }
 
-        val parameterList = convertParameterList(primaryConstructor,
+        val parameterList = correctedConverter.convertParameterList(
-                                                 correctedConverter,
+                primaryConstructor,
-                                                 { parameter, default ->
+                overloadReducer,
-                                                     if (!parameterToField.containsKey(parameter)) {
+                { parameter, default ->
-                                                         correctedConverter.convertParameter(parameter, defaultValue = default)
+                    if (!parameterToField.containsKey(parameter)) {
-                                                     }
+                        correctedConverter.convertParameter(parameter, defaultValue = default)
-                                                     else {
+                    }
-                                                         val (field, type) = parameterToField[parameter]!!
+                    else {
-                                                         val fieldCorrection = fieldCorrections[field]
+                        val (field, type) = parameterToField[parameter]!!
-                                                         val name = fieldCorrection?.identifier ?: field.declarationIdentifier()
+                        val fieldCorrection = fieldCorrections[field]
-                                                         val accessModifiers = if (fieldCorrection != null)
+                        val name = fieldCorrection?.identifier ?: field.declarationIdentifier()
-                                                             Modifiers(listOf()).with(fieldCorrection.access).assignNoPrototype()
+                        val accessModifiers = if (fieldCorrection != null)
-                                                         else
+                            Modifiers(listOf()).with(fieldCorrection.access).assignNoPrototype()
-                                                             converter.convertModifiers(field).filter { it in ACCESS_MODIFIERS }
+                        else
-                                                         Parameter(name,
+                            converter.convertModifiers(field).filter { it in ACCESS_MODIFIERS }
-                                                                   type,
+                        Parameter(name,
-                                                                   if (isVal(converter.referenceSearcher, field)) Parameter.VarValModifier.Val else Parameter.VarValModifier.Var,
+                                  type,
-                                                                   converter.convertAnnotations(parameter) + converter.convertAnnotations(field),
+                                  if (isVal(converter.referenceSearcher, field)) Parameter.VarValModifier.Val else Parameter.VarValModifier.Var,
-                                                                   accessModifiers,
+                                  converter.convertAnnotations(parameter) + converter.convertAnnotations(field),
-                                                                   default).assignPrototypes(listOf(parameter, field), CommentsAndSpacesInheritance(blankLinesBefore = false))
+                                  accessModifiers,
-                                                     }
+                                  default).assignPrototypes(listOf(parameter, field), CommentsAndSpacesInheritance(blankLinesBefore = false))
-                                                 },
+                    }
-                                                 correctCodeConverter = { correct() })
+                },
+                correctCodeConverter = { correct() })
 
         return PrimaryConstructor(annotations, modifiers, parameterList, converter.deferredElement(bodyGenerator)).assignPrototype(primaryConstructor)
     }
 
-    private fun convertParameterList(
-            constructor: PsiMethod,
-            converter: Converter,
-            convertParameter: (parameter: PsiParameter, default: DeferredElement<Expression>?) -> Parameter,
-            correctCodeConverter: CodeConverter.() -> CodeConverter = { this }
-    ): ParameterList {
-        val parameterList = constructor.getParameterList()
-        val params = parameterList.getParameters()
-        val defaults = lastParamDefaults[constructor] ?: emptyList<PsiExpression>()
-        return ParameterList(params.indices.map { i ->
-            val parameter = params[i]
-            val indexFromEnd = params.size() - i - 1
-            val defaultValue = if (indexFromEnd < defaults.size())
-                converter.deferredElement { codeConverter -> codeConverter.correctCodeConverter().convertExpression(defaults[indexFromEnd], parameter.getType()) }
-            else
-                null
-            convertParameter(parameter, defaultValue)
-        }).assignPrototype(parameterList)
-    }
-
     private fun findBackingFieldForConstructorParameter(parameter: PsiParameter, constructor: PsiMethod): Pair<PsiField, PsiStatement>? {
         val body = constructor.getBody() ?: return null
 

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

@@ -16,7 +16,6 @@
 
 package org.jetbrains.kotlin.j2k
 
-import com.google.common.collect.Multimap
 import com.intellij.openapi.project.Project
 import com.intellij.psi.*
 import com.intellij.psi.CommonClassNames.*
@@ -32,6 +31,7 @@ import org.jetbrains.kotlin.j2k.usageProcessing.UsageProcessing
 import org.jetbrains.kotlin.j2k.usageProcessing.UsageProcessingExpressionConverter
 import org.jetbrains.kotlin.types.expressions.OperatorConventions.*
 import java.util.ArrayList
+import java.util.HashMap
 
 class Converter private(
         private val elementToConvert: PsiElement,
@@ -62,7 +62,9 @@ class Converter private(
         public fun create(elementToConvert: PsiElement, settings: ConverterSettings, inConversionScope: (PsiElement) -> Boolean,
                           referenceSearcher: ReferenceSearcher, resolverForConverter: ResolverForConverter,
                           usageProcessingsCollector: (UsageProcessing) -> Unit): Converter {
-            return Converter(elementToConvert, settings, inConversionScope, referenceSearcher, resolverForConverter, CommonState(usageProcessingsCollector), PersonalState(null))
+            return Converter(elementToConvert, settings, inConversionScope,
+                             CachingReferenceSearcher(referenceSearcher),
+                             resolverForConverter, CommonState(usageProcessingsCollector), PersonalState(null))
         }
     }
 
@@ -98,7 +100,7 @@ class Converter private(
     private fun convertTopElement(element: PsiElement): Element? = when (element) {
         is PsiJavaFile -> convertFile(element)
         is PsiClass -> convertClass(element)
-        is PsiMethod -> convertMethod(element, null, null, false)
+        is PsiMethod -> convertMethod(element, null, null, null, false)
         is PsiField -> convertField(element, null)
         is PsiStatement -> createDefaultCodeConverter().convertStatement(element)
         is PsiExpression -> createDefaultCodeConverter().convertExpression(element)
@@ -274,7 +276,8 @@ class Converter private(
 
         // to convert fields and nested types - they are not allowed in Kotlin but we convert them and let user refactor code
         var classBody = ClassBodyConverter(psiClass, this, isOpenClass = false, isObject = false).convertBody()
-        classBody = ClassBody(constructorSignature, classBody.baseClassParams, classBody.members, classBody.companionObjectMembers, classBody.lBrace, classBody.rBrace)
+        classBody = ClassBody(constructorSignature, classBody.baseClassParams, classBody.members,
+                              classBody.companionObjectMembers, classBody.lBrace, classBody.rBrace, classBody.overloadReducer)
 
         val annotationAnnotation = Annotation(Identifier("annotation").assignNoPrototype(), listOf(), false, false).assignNoPrototype()
         return Class(psiClass.declarationIdentifier(),
@@ -348,10 +351,13 @@ class Converter private(
         return if (convertedType == initializerType) null else convertedType
     }
 
-    public fun convertMethod(method: PsiMethod,
+    public fun convertMethod(
-                             membersToRemove: MutableSet<PsiMember>?,
+            method: PsiMethod,
-                             constructorConverter: ConstructorConverter?,
+            membersToRemove: MutableSet<PsiMember>?,
-                             isInOpenClass: Boolean): Member? {
+            constructorConverter: ConstructorConverter?,
+            overloadReducer: OverloadReducer?,
+            isInOpenClass: Boolean
+    ): FunctionLike? {
         val returnType = typeConverter.convertMethodReturnType(method)
 
         val annotations = convertAnnotations(method) + convertThrows(method)
@@ -401,7 +407,8 @@ class Converter private(
                 }
             }
 
-            var params = convertParameterList(method.getParameterList())
+            var params = convertParameterList(method, overloadReducer)
+
             val typeParameterList = convertTypeParameterList(method.getTypeParameterList())
             var body = deferredElement { codeConverter: CodeConverter ->
                 val body = codeConverter.withMethodReturnType(method.getReturnType()).convertBlock(method.getBody())
@@ -410,7 +417,17 @@ class Converter private(
             Function(method.declarationIdentifier(), annotations, modifiers, returnType, typeParameterList, params, body, containingClass?.isInterface() ?: false)
         }
 
-        return function?.assignPrototype(method)
+        if (function == null) return null
+
+        if (function.parameterList.parameters.any { it.defaultValue != null }) {
+            function.annotations += Annotations(
+                    listOf(Annotation(Identifier("overloads").assignNoPrototype(),
+                                      listOf(),
+                                      brackets = function is PrimaryConstructor,
+                                      newLineAfter = false).assignNoPrototype())).assignNoPrototype()
+        }
+
+        return function.assignPrototype(method)
     }
 
     /**
@@ -507,14 +524,13 @@ class Converter private(
     private fun convertToNotNullableTypes(types: Array<out PsiType?>): List<Type>
             = types.map { typeConverter.convertType(it, Nullability.NotNull) }
 
-    private fun convertParameterList(parameterList: PsiParameterList): ParameterList
+    public fun convertParameter(
-            = ParameterList(parameterList.getParameters().map { convertParameter(it) }).assignPrototype(parameterList)
+            parameter: PsiParameter,
-
+            nullability: Nullability = Nullability.Default,
-    public fun convertParameter(parameter: PsiParameter,
+            varValModifier: Parameter.VarValModifier = Parameter.VarValModifier.None,
-                         nullability: Nullability = Nullability.Default,
+            modifiers: Modifiers = Modifiers.Empty,
-                         varValModifier: Parameter.VarValModifier = Parameter.VarValModifier.None,
+            defaultValue: DeferredElement<Expression>? = null
-                         modifiers: Modifiers = Modifiers.Empty,
+    ): Parameter {
-                         defaultValue: DeferredElement<Expression>? = null): Parameter {
         var type = typeConverter.convertVariableType(parameter)
         when (nullability) {
             Nullability.NotNull -> type = type.toNotNullType()
@@ -555,6 +571,27 @@ class Converter private(
         val annotation = Annotation(Identifier("throws").assignNoPrototype(), arguments, false, true)
         return Annotations(listOf(annotation.assignPrototype(throwsList))).assignPrototype(throwsList)
     }
+
+    private class CachingReferenceSearcher(private val searcher: ReferenceSearcher) : ReferenceSearcher by searcher {
+        private val hasInheritorsCached = HashMap<PsiClass, Boolean>()
+        private val hasOverridesCached = HashMap<PsiMethod, Boolean>()
+
+        override fun hasInheritors(`class`: PsiClass): Boolean {
+            val cached = hasInheritorsCached[`class`]
+            if (cached != null) return cached
+            val result = searcher.hasInheritors(`class`)
+            hasInheritorsCached[`class`] = result
+            return result
+        }
+
+        override fun hasOverrides(method: PsiMethod): Boolean {
+            val cached = hasOverridesCached[method]
+            if (cached != null) return cached
+            val result = searcher.hasOverrides(method)
+            hasOverridesCached[method] = result
+            return result
+        }
+    }
 }
 
 val PRIMITIVE_TYPE_CONVERSIONS: Map<String, String> = mapOf(

j2k/src/org/jetbrains/kotlin/j2k/OverloadReducer.kt

@@ -0,0 +1,195 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.j2k
+
+import com.intellij.psi.*
+import org.jetbrains.kotlin.j2k.ast.*
+import java.util.ArrayList
+import java.util.HashMap
+import java.util.HashSet
+
+class OverloadReducer(
+        private val methods: Collection<PsiMethod>,
+        private val isOpenClass: Boolean,
+        private val referenceSearcher: ReferenceSearcher
+) {
+    private val methodToLastParameterDefaults = HashMap<PsiMethod, ArrayList<PsiExpression>>()
+    private val methodsToDrop = HashSet<PsiMethod>()
+
+    init {
+        val map = buildOverloadEquivalenceMap()
+        dropOverloadsForDefaultValues(map)
+    }
+
+    public fun shouldDropMethod(method: PsiMethod): Boolean = method in methodsToDrop
+
+    public fun parameterDefault(method: PsiMethod, parameterIndex: Int): PsiExpression? {
+        val defaults = methodToLastParameterDefaults[method] ?: return null
+        val index = method.getParameterList().getParametersCount() - parameterIndex - 1
+        return if (index < defaults.size()) defaults[index] else null
+    }
+
+    private class EquivalentOverloadInfo(
+            /**
+             * Target method (one which is finally invoked by this one)
+             */
+            val method: PsiMethod,
+            /**
+             * This method is equivalent to the target method with a few last parameters having default values
+             */
+            val parameterDefaults: List<PsiExpression>)
+
+    private fun buildOverloadEquivalenceMap(): Map<PsiMethod, EquivalentOverloadInfo> {
+        val overloadGroups = methods
+                .groupBy { listOf(if (it.isConstructor()) null else it.getName(),
+                                  it.accessModifier(),
+                                  it.getReturnType(),
+                                  it.hasModifierProperty(PsiModifier.STATIC),
+                                  getAnnotationsFingerprint(it)) }
+                .values()
+                .filter { it.size() > 1 }
+                .map { it.filterNot { shouldSkipOverload(it) } }
+                .filter { it.size() > 1 }
+
+        val map = HashMap<PsiMethod, EquivalentOverloadInfo>()
+        for (group in overloadGroups) {
+            for (method in group) {
+                val overloadInfo = findEquivalentOverload(method, group) ?: continue
+
+                val furtherOverloadInfo = map[overloadInfo.method]
+                val resultOverloadInfo = if (furtherOverloadInfo != null) {
+                    EquivalentOverloadInfo(furtherOverloadInfo.method, overloadInfo.parameterDefaults + furtherOverloadInfo.parameterDefaults)
+                }
+                else {
+                    overloadInfo
+                }
+
+                map[method] = resultOverloadInfo
+                for (entry in map.entrySet()) {
+                    if (entry.value.method == method) {
+                        val newParameterDefaults = entry.value.parameterDefaults + resultOverloadInfo.parameterDefaults
+                        entry.setValue(EquivalentOverloadInfo(resultOverloadInfo.method, newParameterDefaults))
+                    }
+                }
+
+            }
+        }
+
+        return map
+    }
+
+    private fun shouldSkipOverload(method: PsiMethod): Boolean {
+        if (method.isConstructor()) return false
+        if (method.hasModifierProperty(PsiModifier.ABSTRACT)) return true
+        if (method.hasModifierProperty(PsiModifier.NATIVE)) return true
+        if (method.hasModifierProperty(PsiModifier.SYNCHRONIZED)) return true
+        if (method.getHierarchicalMethodSignature().getSuperSignatures().isNotEmpty()) return true
+        if (isOpenClass && referenceSearcher.hasOverrides(method)) return true
+        return false
+    }
+
+    private fun findEquivalentOverload(method: PsiMethod, overloads: Collection<PsiMethod>): EquivalentOverloadInfo? {
+        val statement = method.getBody()?.getStatements()?.singleOrNull() ?: return null
+
+        val methodCall = when (statement) {
+            is PsiExpressionStatement -> statement.getExpression()
+            is PsiReturnStatement -> statement.getReturnValue()
+            else -> null
+        } as? PsiMethodCallExpression ?: return null
+
+        val expectedMethodName = if (method.isConstructor()) "this" else method.getName()
+        val refExpr = methodCall.getMethodExpression()
+        if (refExpr.isQualified() || refExpr.getReferenceName() != expectedMethodName) return null
+
+        val target = refExpr.resolve() as? PsiMethod ?: return null
+        if (target !in overloads) return null
+
+        val parameterDefaults = calcTargetParameterDefaults(method, target, methodCall) ?: return null
+        return EquivalentOverloadInfo(target, parameterDefaults)
+    }
+
+    private fun calcTargetParameterDefaults(method: PsiMethod, target: PsiMethod, targetCall: PsiMethodCallExpression): List<PsiExpression>? {
+        val parameters = method.getParameterList().getParameters()
+        val targetParameters = target.getParameterList().getParameters()
+        if (parameters.size() >= targetParameters.size()) return null
+        val args = targetCall.getArgumentList().getExpressions()
+        if (args.size() != targetParameters.size()) return null // incorrect code
+
+        for (i in parameters.indices) {
+            val parameter = parameters[i]
+            val targetParameter = targetParameters[i]
+            if (parameter.getName() != targetParameter.getName() || parameter.getType() != targetParameter.getType()) return null
+            val arg = args[i]
+            if (arg !is PsiReferenceExpression || arg.resolve() != parameter) return null
+        }
+
+        return args.drop(parameters.size())
+    }
+
+    private fun dropOverloadsForDefaultValues(equivalenceMap: Map<PsiMethod, EquivalentOverloadInfo>) {
+        val dropCandidates = equivalenceMap
+                .map { it.key }
+                .sortBy { -it.getParameterList().getParametersCount() } // we will try to drop them starting from ones with more parameters
+
+        @DropCandidatesLoop
+        for (method in dropCandidates) {
+            val paramCount = method.getParameterList().getParametersCount()
+            val targetInfo = equivalenceMap[method]!!
+            val targetParamCount = targetInfo.method.getParameterList().getParametersCount()
+            assert(paramCount < targetParamCount)
+            val defaults = targetInfo.parameterDefaults
+            assert(defaults.size() == targetParamCount - paramCount)
+
+            val targetDefaults = methodToLastParameterDefaults.getOrPut(targetInfo.method, { ArrayList() })
+
+            for (i in defaults.indices) {
+                val default = defaults[defaults.size() - i - 1]
+                if (i < targetDefaults.size()) { // default for this parameter has already been assigned
+                    if (targetDefaults[i].getText() != default.getText()) continue@DropCandidatesLoop
+                }
+                else {
+                    targetDefaults.add(default)
+                }
+            }
+
+            methodsToDrop.add(method)
+        }
+    }
+
+    private fun getAnnotationsFingerprint(method: PsiMethod): Any {
+        return method.getModifierList().getAnnotations().map { it.getText() }
+    }
+}
+
+public fun Converter.convertParameterList(
+        method: PsiMethod,
+        overloadReducer: OverloadReducer?,
+        convertParameter: (parameter: PsiParameter, default: DeferredElement<Expression>?) -> Parameter = { parameter, default -> convertParameter(parameter, defaultValue = default) },
+        correctCodeConverter: CodeConverter.() -> CodeConverter = { this }
+): ParameterList {
+    val parameterList = method.getParameterList()
+    val params = parameterList.getParameters()
+    return ParameterList(params.indices.map { i ->
+        val parameter = params[i]
+        val defaultValue = overloadReducer?.parameterDefault(method, i)
+        val defaultValueConverted = if (defaultValue != null)
+            deferredElement { codeConverter -> codeConverter.correctCodeConverter().convertExpression(defaultValue, parameter.getType()) }
+        else
+            null
+        convertParameter(parameter, defaultValueConverted)
+    }).assignPrototype(parameterList)
+}

j2k/src/org/jetbrains/kotlin/j2k/ast/ClassBody.kt

@@ -16,7 +16,11 @@
 
 package org.jetbrains.kotlin.j2k.ast
 
-import org.jetbrains.kotlin.j2k.*
+import com.intellij.psi.PsiExpression
+import com.intellij.psi.PsiMethod
+import org.jetbrains.kotlin.j2k.CodeBuilder
+import org.jetbrains.kotlin.j2k.OverloadReducer
+import org.jetbrains.kotlin.j2k.append
 
 abstract class Member(var annotations: Annotations, val modifiers: Modifiers) : Element()
 
@@ -26,7 +30,8 @@ class ClassBody (
         val members: List<Member>,
         val companionObjectMembers: List<Member>,
         val lBrace: LBrace,
-        val rBrace: RBrace) {
+        val rBrace: RBrace,
+        val overloadReducer: OverloadReducer) {
 
     fun append(builder: CodeBuilder) {
         val membersFiltered = members.filter { !it.isEmpty }

j2k/src/org/jetbrains/kotlin/j2k/ast/Constructors.kt

@@ -22,9 +22,9 @@ import com.intellij.util.IncorrectOperationException
 abstract class Constructor(
         annotations: Annotations,
         modifiers: Modifiers,
-        public val parameterList: ParameterList,
+        parameterList: ParameterList,
-        protected val body: DeferredElement<Block>
+        body: DeferredElement<Block>
-) : Member(annotations, modifiers)
+) : FunctionLike(annotations, modifiers, parameterList, body)
 
 class PrimaryConstructor(
         annotations: Annotations,
@@ -36,14 +36,14 @@ class PrimaryConstructor(
     override fun generateCode(builder: CodeBuilder) { throw IncorrectOperationException() }
 
     public fun initializer(): Initializer
-            = Initializer(body, Modifiers.Empty).assignPrototypesFrom(this, CommentsAndSpacesInheritance(commentsBefore = false))
+            = Initializer(body!!, Modifiers.Empty).assignPrototypesFrom(this, CommentsAndSpacesInheritance(commentsBefore = false))
 
     public fun createSignature(converter: Converter): PrimaryConstructorSignature {
         val signature = PrimaryConstructorSignature(annotations, modifiers, parameterList)
 
         // assign prototypes later because we don't know yet whether the body is empty or not
         converter.addPostUnfoldDeferredElementsAction {
-            val inheritance = CommentsAndSpacesInheritance(blankLinesBefore = false, commentsAfter = body.isEmpty, commentsInside = body.isEmpty)
+            val inheritance = CommentsAndSpacesInheritance(blankLinesBefore = false, commentsAfter = body!!.isEmpty, commentsInside = body.isEmpty)
             signature.assignPrototypesFrom(this, inheritance)
         }
 
@@ -89,7 +89,7 @@ class SecondaryConstructor(
             builder append " : " append thisOrSuperCall
         }
 
-        builder append " " append body
+        builder append " " append body!!
     }
 }
 

j2k/src/org/jetbrains/kotlin/j2k/ast/Function.kt

@@ -18,16 +18,23 @@ package org.jetbrains.kotlin.j2k.ast
 
 import org.jetbrains.kotlin.j2k.*
 
+abstract class FunctionLike(
+        annotations: Annotations,
+        modifiers: Modifiers,
+        val parameterList: ParameterList,
+        val body: DeferredElement<Block>?
+) : Member(annotations, modifiers)
+
 class Function(
         val name: Identifier,
         annotations: Annotations,
         modifiers: Modifiers,
         val returnType: Type,
         val typeParameterList: TypeParameterList,
-        val parameterList: ParameterList,
+        parameterList: ParameterList,
-        val body: DeferredElement<Block>?,
+        body: DeferredElement<Block>?,
         val isInTrait: Boolean
-) : Member(annotations, modifiers) {
+) : FunctionLike(annotations, modifiers, parameterList, body) {
 
     private fun presentationModifiers(): Modifiers {
         var modifiers = this.modifiers

j2k/testData/fileOrElement/constructors/secondaryConstructorWithDefaultValues2.java

@@ -0,0 +1,17 @@
+class A {
+    private String s = "";
+    private int x = 0;
+
+    public A() {
+    }
+
+    public A(int p, String s){
+        this(p, s, 1);
+    }
+
+    public A(int p, String s, int x) {
+        this();
+        this.s = s;
+        this.x = x;
+    }
+}

j2k/testData/fileOrElement/constructors/secondaryConstructorWithDefaultValues2.kt

@@ -0,0 +1,11 @@
+// ERROR: Val cannot be reassigned
+// ERROR: Val cannot be reassigned
+class A() {
+    private val s = ""
+    private val x = 0
+
+    overloads public constructor(p: Int, s: String, x: Int = 1) : this() {
+        this.s = s
+        this.x = x
+    }
+}

j2k/testData/fileOrElement/overloads/Abstract.java

@@ -0,0 +1,7 @@
+abstract class A {
+    public abstract void foo(int p);
+
+    public void foo(){
+        foo(1);
+    }
+}

j2k/testData/fileOrElement/overloads/Abstract.kt

@@ -0,0 +1,7 @@
+abstract class A {
+    public abstract fun foo(p: Int)
+
+    public fun foo() {
+        foo(1)
+    }
+}

j2k/testData/fileOrElement/overloads/AccessorToDrop.java

@@ -0,0 +1,15 @@
+class A {
+    private int field = 0;
+
+    public int getField() {
+        return field;
+    }
+
+    public void setField(int field) {
+        this.field = field;
+    }
+
+    public void setField() {
+        setField(0);
+    }
+}

j2k/testData/fileOrElement/overloads/AccessorToDrop.kt

@@ -0,0 +1,7 @@
+class A {
+    public var field: Int = 0
+
+    public fun setField() {
+        field = 0
+    }
+}

j2k/testData/fileOrElement/overloads/Annotations.java

@@ -0,0 +1,44 @@
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+class A {
+    @NotNull
+    Object foo(String s) {
+        System.out.println("s = " + s);
+        return "";
+    }
+
+    @NotNull
+    Object foo() {
+        return foo(null);
+    }
+
+    @Nullable
+    Object bar(String s) {
+        System.out.println("s = " + s);
+        return s == null ? "" : null;
+    }
+
+    @NotNull
+    Object bar() {
+        return bar(null);
+    }
+
+    public @Nullable Object bar1(String s) {
+        System.out.println("s = " + s);
+        return s == null ? "" : null;
+    }
+
+    public @NotNull Object bar1() {
+        return bar1(null);
+    }
+
+    @Deprecated
+    public void f() {
+        f(1);
+    }
+
+    public void f(int p) {
+        System.out.println("p = " + p);
+    }
+}

j2k/testData/fileOrElement/overloads/Annotations.kt

@@ -0,0 +1,35 @@
+// ERROR: Type mismatch: inferred type is kotlin.Any? but kotlin.Any was expected
+// ERROR: Type mismatch: inferred type is kotlin.Any? but kotlin.Any was expected
+class A {
+    overloads fun foo(s: String? = null): Any {
+        println("s = " + s!!)
+        return ""
+    }
+
+    fun bar(s: String?): Any? {
+        println("s = " + s!!)
+        return if (s == null) "" else null
+    }
+
+    fun bar(): Any {
+        return bar(null)
+    }
+
+    public fun bar1(s: String?): Any? {
+        println("s = " + s!!)
+        return if (s == null) "" else null
+    }
+
+    public fun bar1(): Any {
+        return bar1(null)
+    }
+
+    deprecated("")
+    public fun f() {
+        f(1)
+    }
+
+    public fun f(p: Int) {
+        println("p = " + p)
+    }
+}

j2k/testData/fileOrElement/overloads/Override.java

@@ -0,0 +1,46 @@
+interface I {
+    void foo(int i, char c, String s);
+    void bar();
+}
+
+class A implements I{
+    public void foo(int i, char c, String s) {
+        System.out.println("foo" + i + c + s);
+    }
+
+    public void foo(int i, char c) {
+        foo(i, c, "");
+    }
+
+    public void foo(int i) {
+        foo(i, 'a', "");
+    }
+
+    public void bar() {
+        bar(1);
+    }
+
+    public void bar(int i) {}
+
+    public void x() {
+        x(1);
+    }
+
+    public void x(int i) {}
+
+    public void y() {
+        y(1);
+    }
+
+    public void y(int i) {}
+}
+
+class B extends A {
+    public void x() {
+        super.x();
+    }
+
+    public void y(int i) {
+        super.y(i);
+    }
+}

j2k/testData/fileOrElement/overloads/Override.kt

@@ -0,0 +1,49 @@
+trait I {
+    public fun foo(i: Int, c: Char, s: String)
+    public fun bar()
+}
+
+open class A : I {
+    override fun foo(i: Int, c: Char, s: String) {
+        println("foo" + i + c + s)
+    }
+
+    public fun foo(i: Int, c: Char) {
+        foo(i, c, "")
+    }
+
+    public fun foo(i: Int) {
+        foo(i, 'a', "")
+    }
+
+    override fun bar() {
+        bar(1)
+    }
+
+    public fun bar(i: Int) {
+    }
+
+    public open fun x() {
+        x(1)
+    }
+
+    public fun x(i: Int) {
+    }
+
+    public fun y() {
+        y(1)
+    }
+
+    public open fun y(i: Int) {
+    }
+}
+
+class B : A() {
+    override fun x() {
+        super.x()
+    }
+
+    override fun y(i: Int) {
+        super.y(i)
+    }
+}

j2k/testData/fileOrElement/overloads/Simple.java

@@ -0,0 +1,22 @@
+class A {
+    void foo(int i, char c, String s) {
+        System.out.println("foo" + i + c + s);
+    }
+
+    void foo(int i, char c) {
+        foo(i, c, "");
+    }
+
+    void foo(int i) {
+        foo(i, 'a', "");
+    }
+
+    int bar(String s) {
+        System.out.println("s = " + s);
+        return 0;
+    }
+
+    int bar() {
+        return bar(null);
+    }
+}

j2k/testData/fileOrElement/overloads/Simple.kt

@@ -0,0 +1,10 @@
+class A {
+    overloads fun foo(i: Int, c: Char = 'a', s: String = "") {
+        println("foo" + i + c + s)
+    }
+
+    overloads fun bar(s: String? = null): Int {
+        println("s = " + s!!)
+        return 0
+    }
+}

j2k/testData/fileOrElement/overloads/Synchronized.java

@@ -0,0 +1,12 @@
+class A {
+    public void foo(int p) {
+        System.out.println("p = [" + p + "]");
+    }
+
+    public synchronized void foo(){
+        foo(calcSomething());
+    }
+
+    // this method should be invoked under synchronized block!
+    private int calcSomething() { return 0; }
+}

j2k/testData/fileOrElement/overloads/Synchronized.kt

@@ -0,0 +1,14 @@
+class A {
+    public fun foo(p: Int) {
+        println("p = [" + p + "]")
+    }
+
+    synchronized public fun foo() {
+        foo(calcSomething())
+    }
+
+    // this method should be invoked under synchronized block!
+    private fun calcSomething(): Int {
+        return 0
+    }
+}

j2k/tests/org/jetbrains/kotlin/j2k/JavaToKotlinConverterForWebDemoTestGenerated.java

@@ -78,6 +78,7 @@ import java.util.regex.Pattern;
         JavaToKotlinConverterForWebDemoTestGenerated.NewClassExpression.class,
         JavaToKotlinConverterForWebDemoTestGenerated.Nullability.class,
         JavaToKotlinConverterForWebDemoTestGenerated.ObjectLiteral.class,
+        JavaToKotlinConverterForWebDemoTestGenerated.Overloads.class,
         JavaToKotlinConverterForWebDemoTestGenerated.PackageStatement.class,
         JavaToKotlinConverterForWebDemoTestGenerated.ParenthesizedExpression.class,
         JavaToKotlinConverterForWebDemoTestGenerated.PolyadicExpression.class,
@@ -1313,6 +1314,12 @@ public class JavaToKotlinConverterForWebDemoTestGenerated extends AbstractJavaTo
             doTest(fileName);
         }
 
+        @TestMetadata("secondaryConstructorWithDefaultValues2.java")
+        public void testSecondaryConstructorWithDefaultValues2() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/constructors/secondaryConstructorWithDefaultValues2.java");
+            doTest(fileName);
+        }
+
         @TestMetadata("secondaryConstructorsInInnerClass.java")
         public void testSecondaryConstructorsInInnerClass() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/constructors/secondaryConstructorsInInnerClass.java");
@@ -3489,6 +3496,51 @@ public class JavaToKotlinConverterForWebDemoTestGenerated extends AbstractJavaTo
         }
     }
 
+    @TestMetadata("j2k/testData/fileOrElement/overloads")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class Overloads extends AbstractJavaToKotlinConverterForWebDemoTest {
+        @TestMetadata("Abstract.java")
+        public void testAbstract() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/overloads/Abstract.java");
+            doTest(fileName);
+        }
+
+        @TestMetadata("AccessorToDrop.java")
+        public void testAccessorToDrop() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/overloads/AccessorToDrop.java");
+            doTest(fileName);
+        }
+
+        public void testAllFilesPresentInOverloads() throws Exception {
+            JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("j2k/testData/fileOrElement/overloads"), Pattern.compile("^(.+)\\.java$"), true);
+        }
+
+        @TestMetadata("Annotations.java")
+        public void testAnnotations() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/overloads/Annotations.java");
+            doTest(fileName);
+        }
+
+        @TestMetadata("Override.java")
+        public void testOverride() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/overloads/Override.java");
+            doTest(fileName);
+        }
+
+        @TestMetadata("Simple.java")
+        public void testSimple() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/overloads/Simple.java");
+            doTest(fileName);
+        }
+
+        @TestMetadata("Synchronized.java")
+        public void testSynchronized() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/overloads/Synchronized.java");
+            doTest(fileName);
+        }
+    }
+
     @TestMetadata("j2k/testData/fileOrElement/packageStatement")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)

j2k/tests/org/jetbrains/kotlin/j2k/JavaToKotlinConverterSingleFileTestGenerated.java

@@ -78,6 +78,7 @@ import java.util.regex.Pattern;
         JavaToKotlinConverterSingleFileTestGenerated.NewClassExpression.class,
         JavaToKotlinConverterSingleFileTestGenerated.Nullability.class,
         JavaToKotlinConverterSingleFileTestGenerated.ObjectLiteral.class,
+        JavaToKotlinConverterSingleFileTestGenerated.Overloads.class,
         JavaToKotlinConverterSingleFileTestGenerated.PackageStatement.class,
         JavaToKotlinConverterSingleFileTestGenerated.ParenthesizedExpression.class,
         JavaToKotlinConverterSingleFileTestGenerated.PolyadicExpression.class,
@@ -1313,6 +1314,12 @@ public class JavaToKotlinConverterSingleFileTestGenerated extends AbstractJavaTo
             doTest(fileName);
         }
 
+        @TestMetadata("secondaryConstructorWithDefaultValues2.java")
+        public void testSecondaryConstructorWithDefaultValues2() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/constructors/secondaryConstructorWithDefaultValues2.java");
+            doTest(fileName);
+        }
+
         @TestMetadata("secondaryConstructorsInInnerClass.java")
         public void testSecondaryConstructorsInInnerClass() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/constructors/secondaryConstructorsInInnerClass.java");
@@ -3489,6 +3496,51 @@ public class JavaToKotlinConverterSingleFileTestGenerated extends AbstractJavaTo
         }
     }
 
+    @TestMetadata("j2k/testData/fileOrElement/overloads")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class Overloads extends AbstractJavaToKotlinConverterSingleFileTest {
+        @TestMetadata("Abstract.java")
+        public void testAbstract() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/overloads/Abstract.java");
+            doTest(fileName);
+        }
+
+        @TestMetadata("AccessorToDrop.java")
+        public void testAccessorToDrop() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/overloads/AccessorToDrop.java");
+            doTest(fileName);
+        }
+
+        public void testAllFilesPresentInOverloads() throws Exception {
+            JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("j2k/testData/fileOrElement/overloads"), Pattern.compile("^(.+)\\.java$"), true);
+        }
+
+        @TestMetadata("Annotations.java")
+        public void testAnnotations() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/overloads/Annotations.java");
+            doTest(fileName);
+        }
+
+        @TestMetadata("Override.java")
+        public void testOverride() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/overloads/Override.java");
+            doTest(fileName);
+        }
+
+        @TestMetadata("Simple.java")
+        public void testSimple() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/overloads/Simple.java");
+            doTest(fileName);
+        }
+
+        @TestMetadata("Synchronized.java")
+        public void testSynchronized() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/testData/fileOrElement/overloads/Synchronized.java");
+            doTest(fileName);
+        }
+    }
+
     @TestMetadata("j2k/testData/fileOrElement/packageStatement")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)