Introduce initial version of FIR Java type enhancement

Java type enhancement is performed by a special scope kind
Java FIR dump was added for multiplatform tests to look at enhancements
Overrides, J2K mapping, special cases does not work yet

Related to KT-29937

compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeTypes.kt

@@ -65,6 +65,10 @@ sealed class ConeKotlinType : ConeKotlinTypeProjection(), ConeTypedProjection, K
     abstract val nullability: ConeNullability
 }
 
+val ConeKotlinType.isNullable: Boolean get() = nullability != ConeNullability.NOT_NULL
+
+val ConeKotlinType.isMarkedNullable: Boolean get() = nullability == ConeNullability.NULLABLE
+
 class ConeKotlinErrorType(val reason: String) : ConeKotlinType() {
     override val typeArguments: Array<out ConeKotlinTypeProjection>
         get() = EMPTY_ARRAY

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/FirJavaModuleBasedSession.kt

@@ -9,11 +9,11 @@ import com.intellij.openapi.project.Project
 import com.intellij.psi.search.GlobalSearchScope
 import org.jetbrains.kotlin.analyzer.ModuleInfo
 import org.jetbrains.kotlin.fir.*
+import org.jetbrains.kotlin.fir.java.scopes.JavaFirScopeProvider
 import org.jetbrains.kotlin.fir.resolve.FirProvider
+import org.jetbrains.kotlin.fir.resolve.FirScopeProvider
 import org.jetbrains.kotlin.fir.resolve.FirSymbolProvider
-import org.jetbrains.kotlin.fir.resolve.impl.FirCompositeSymbolProvider
-import org.jetbrains.kotlin.fir.resolve.impl.FirDependenciesSymbolProviderImpl
-import org.jetbrains.kotlin.fir.resolve.impl.FirLibrarySymbolProviderImpl
+import org.jetbrains.kotlin.fir.resolve.impl.*
 
 class FirJavaModuleBasedSession(
     moduleInfo: ModuleInfo,
@@ -21,7 +21,6 @@ class FirJavaModuleBasedSession(
     scope: GlobalSearchScope,
     dependenciesProvider: FirSymbolProvider? = null
 ) : FirModuleBasedSession(moduleInfo) {
-
     init {
         sessionProvider.sessionCache[moduleInfo] = this
         registerComponent(
@@ -35,6 +34,15 @@ class FirJavaModuleBasedSession(
                 )
             )
         )
+        registerComponent(
+            FirScopeProvider::class,
+            FirCompositeScopeProvider(
+                listOf(
+                    JavaFirScopeProvider(),
+                    FirRegularScopeProvider()
+                )
+            )
+        )
     }
 }
 
@@ -55,6 +63,15 @@ class FirLibrarySession(
                 )
             )
         )
+        registerComponent(
+            FirScopeProvider::class,
+            FirCompositeScopeProvider(
+                listOf(
+                    JavaFirScopeProvider(),
+                    FirRegularScopeProvider()
+                )
+            )
+        )
     }
 }
 

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/JavaSymbolProvider.kt

@@ -9,37 +9,23 @@ import com.intellij.openapi.project.Project
 import com.intellij.psi.search.GlobalSearchScope
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.FirNamedFunction
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.declarations.impl.FirModifiableClass
-import org.jetbrains.kotlin.fir.declarations.impl.FirTypeParameterImpl
-import org.jetbrains.kotlin.fir.expressions.FirAnnotationCall
-import org.jetbrains.kotlin.fir.expressions.FirArrayOfCall
-import org.jetbrains.kotlin.fir.expressions.FirExpression
-import org.jetbrains.kotlin.fir.expressions.impl.*
 import org.jetbrains.kotlin.fir.java.declarations.FirJavaClass
 import org.jetbrains.kotlin.fir.java.declarations.FirJavaMethod
 import org.jetbrains.kotlin.fir.java.declarations.FirJavaValueParameter
-import org.jetbrains.kotlin.fir.java.types.FirJavaTypeRef
-import org.jetbrains.kotlin.fir.references.FirErrorNamedReference
-import org.jetbrains.kotlin.fir.references.FirResolvedCallableReferenceImpl
 import org.jetbrains.kotlin.fir.resolve.AbstractFirSymbolProvider
-import org.jetbrains.kotlin.fir.resolve.FirSymbolProvider
-import org.jetbrains.kotlin.fir.service
-import org.jetbrains.kotlin.fir.symbols.*
+import org.jetbrains.kotlin.fir.symbols.CallableId
+import org.jetbrains.kotlin.fir.symbols.ConeCallableSymbol
+import org.jetbrains.kotlin.fir.symbols.ConeClassLikeSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirFunctionSymbol
-import org.jetbrains.kotlin.fir.symbols.impl.FirTypeParameterSymbol
-import org.jetbrains.kotlin.fir.types.*
-import org.jetbrains.kotlin.fir.types.impl.ConeClassTypeImpl
-import org.jetbrains.kotlin.fir.types.impl.ConeTypeParameterTypeImpl
-import org.jetbrains.kotlin.fir.types.impl.FirResolvedTypeRefImpl
-import org.jetbrains.kotlin.ir.expressions.IrConstKind
 import org.jetbrains.kotlin.load.java.JavaClassFinder
-import org.jetbrains.kotlin.load.java.structure.*
+import org.jetbrains.kotlin.load.java.structure.JavaClass
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.jvm.KotlinJavaPsiFacade
-import org.jetbrains.kotlin.types.Variance
 
 class JavaSymbolProvider(
     val session: FirSession,
@@ -49,149 +35,6 @@ class JavaSymbolProvider(
 
     private val facade: KotlinJavaPsiFacade get() = KotlinJavaPsiFacade.getInstance(project)
 
-    private fun JavaAnnotation.toFirAnnotationCall(): FirAnnotationCall {
-        return FirAnnotationCallImpl(
-            session, psi = null, useSiteTarget = null,
-            annotationTypeRef = FirResolvedTypeRefImpl(
-                session = session,
-                psi = null,
-                type = ConeClassTypeImpl(FirClassSymbol(classId!!).toLookupTag(), emptyArray(), isNullable = false),
-                isMarkedNullable = true,
-                annotations = emptyList()
-            )
-        ).apply {
-            for (argument in this@toFirAnnotationCall.arguments) {
-                arguments += argument.toFirExpression()
-            }
-        }
-    }
-
-    // TODO: use kind here
-    private fun <T> List<T>.createArrayOfCall(@Suppress("UNUSED_PARAMETER") kind: IrConstKind<T>): FirArrayOfCall {
-        return FirArrayOfCallImpl(session, null).apply {
-            for (element in this@createArrayOfCall) {
-                arguments += element.createConstant()
-            }
-        }
-    }
-
-    private fun Any?.createConstant(): FirExpression {
-        return when (this) {
-            is Byte -> FirConstExpressionImpl(session, null, IrConstKind.Byte, this)
-            is Short -> FirConstExpressionImpl(session, null, IrConstKind.Short, this)
-            is Int -> FirConstExpressionImpl(session, null, IrConstKind.Int, this)
-            is Long -> FirConstExpressionImpl(session, null, IrConstKind.Long, this)
-            is Char -> FirConstExpressionImpl(session, null, IrConstKind.Char, this)
-            is Float -> FirConstExpressionImpl(session, null, IrConstKind.Float, this)
-            is Double -> FirConstExpressionImpl(session, null, IrConstKind.Double, this)
-            is Boolean -> FirConstExpressionImpl(session, null, IrConstKind.Boolean, this)
-            is String -> FirConstExpressionImpl(session, null, IrConstKind.String, this)
-            null -> FirConstExpressionImpl(session, null, IrConstKind.Null, null)
-
-            else -> FirErrorExpressionImpl(session, null, "Unknown value in JavaLiteralAnnotationArgument: $this")
-        }
-    }
-
-    private fun JavaAnnotationArgument.toFirExpression(): FirExpression {
-        // TODO: this.name
-        return when (this) {
-            is JavaLiteralAnnotationArgument -> {
-                when (val value = value) {
-                    is ByteArray -> value.toList().createArrayOfCall(IrConstKind.Byte)
-                    is ShortArray -> value.toList().createArrayOfCall(IrConstKind.Short)
-                    is IntArray -> value.toList().createArrayOfCall(IrConstKind.Int)
-                    is LongArray -> value.toList().createArrayOfCall(IrConstKind.Long)
-                    is CharArray -> value.toList().createArrayOfCall(IrConstKind.Char)
-                    is FloatArray -> value.toList().createArrayOfCall(IrConstKind.Float)
-                    is DoubleArray -> value.toList().createArrayOfCall(IrConstKind.Double)
-                    is BooleanArray -> value.toList().createArrayOfCall(IrConstKind.Boolean)
-                    else -> value.createConstant()
-                }
-            }
-            is JavaArrayAnnotationArgument -> FirArrayOfCallImpl(session, null).apply {
-                for (element in getElements()) {
-                    arguments += element.toFirExpression()
-                }
-            }
-            is JavaEnumValueAnnotationArgument -> {
-                FirFunctionCallImpl(session, null).apply {
-                    val classId = this@toFirExpression.enumClassId
-                    val entryName = this@toFirExpression.entryName
-                    val calleeReference = if (classId != null && entryName != null) {
-                        val callableSymbol = session.service<FirSymbolProvider>().getCallableSymbols(
-                            CallableId(classId.packageFqName, classId.relativeClassName, entryName)
-                        ).firstOrNull()
-                        callableSymbol?.let {
-                            FirResolvedCallableReferenceImpl(session, null, entryName, it)
-                        }
-                    } else {
-                        null
-                    }
-                    this.calleeReference = calleeReference
-                        ?: FirErrorNamedReference(session, null, "Strange Java enum value: ${this@toFirExpression}")
-                }
-            }
-            is JavaClassObjectAnnotationArgument -> FirGetClassCallImpl(session, null).apply {
-                val referencedType = getReferencedType()
-                arguments += FirClassReferenceExpressionImpl(session, null, referencedType.toFirResolvedTypeRef())
-            }
-            is JavaAnnotationAsAnnotationArgument -> getAnnotation().toFirAnnotationCall()
-            else -> FirErrorExpressionImpl(session, null, "Unknown JavaAnnotationArgument: ${this::class.java}")
-        }
-    }
-
-    private fun JavaClassifierType.toFirResolvedTypeRef(): FirResolvedTypeRef {
-        val coneType = when (val classifier = classifier) {
-            is JavaClass -> {
-                val lookupTag = ConeClassLikeLookupTagImpl(classifier.classId!!)
-                ConeClassTypeImpl(lookupTag, typeArguments.map { it.toConeProjection() }.toTypedArray(), isNullable = false)
-            }
-            is JavaTypeParameter -> {
-                // TODO: it's unclear how to identify type parameter by the symbol
-                // TODO: some type parameter cache (provider?)
-                val symbol = createTypeParameterSymbol(classifier.name)
-                ConeTypeParameterTypeImpl(symbol, isNullable = false)
-            }
-            else -> ConeClassErrorType(reason = "Unexpected classifier: $classifier")
-        }
-        return FirResolvedTypeRefImpl(
-            session, psi = null, type = coneType,
-            isMarkedNullable = false, annotations = annotations.map { it.toFirAnnotationCall() }
-        )
-    }
-
-    private fun JavaType.toFirJavaTypeRef(): FirJavaTypeRef {
-        val annotations = (this as? JavaClassifierType)?.annotations.orEmpty()
-        return FirJavaTypeRef(session, annotations = annotations.map { it.toFirAnnotationCall() }, type = this)
-    }
-
-    private fun JavaType.toFirResolvedTypeRef(): FirResolvedTypeRef {
-        if (this is JavaClassifierType) return toFirResolvedTypeRef()
-        return FirResolvedTypeRefImpl(
-            session, psi = null, type = ConeClassErrorType("Unexpected JavaType: $this"),
-            isMarkedNullable = false, annotations = emptyList()
-        )
-    }
-
-    private fun JavaType.toConeProjection(): ConeKotlinTypeProjection {
-        if (this is JavaClassifierType) {
-            return toFirResolvedTypeRef().type
-        }
-        return ConeClassErrorType("Unexpected type argument: $this")
-    }
-
-    private fun createTypeParameterSymbol(name: Name): FirTypeParameterSymbol {
-        val firSymbol = FirTypeParameterSymbol()
-        FirTypeParameterImpl(session, null, firSymbol, name, variance = Variance.INVARIANT, isReified = false)
-        return firSymbol
-    }
-
-    private fun FirAbstractAnnotatedElement.addAnnotationsFrom(javaAnnotationOwner: JavaAnnotationOwner) {
-        for (annotation in javaAnnotationOwner.annotations) {
-            annotations += annotation.toFirAnnotationCall()
-        }
-    }
-
     private fun findClass(classId: ClassId): JavaClass? = facade.findClass(JavaClassFinder.Request(classId), searchScope)
 
     override fun getCallableSymbols(callableId: CallableId): List<ConeCallableSymbol> {
@@ -201,39 +44,12 @@ class JavaSymbolProvider(
                 ?: return@lookupCacheOrCalculate emptyList()
             val firClass = classSymbol.fir as FirModifiableClass
             val callableSymbols = mutableListOf<ConeCallableSymbol>()
-            findClass(classId)?.let { javaClass ->
-                if (firClass.declarations.isEmpty()) {
-                    for (javaMethod in javaClass.methods) {
-                        val methodName = javaMethod.name
-                        val methodId = CallableId(callableId.packageName, callableId.className, methodName)
-                        val methodSymbol = FirFunctionSymbol(methodId)
-                        val memberFunction = FirJavaMethod(
-                            session, methodSymbol, methodName,
-                            javaMethod.visibility, javaMethod.modality,
-                            returnTypeRef = javaMethod.returnType.toFirJavaTypeRef()
-                        ).apply {
-                            for (typeParameter in javaMethod.typeParameters) {
-                                typeParameters += createTypeParameterSymbol(typeParameter.name).fir
-                            }
-                            addAnnotationsFrom(javaMethod)
-                            for (valueParameter in javaMethod.valueParameters) {
-                                valueParameters += FirJavaValueParameter(
-                                    session, valueParameter.name ?: Name.special("<anonymous Java parameter>"),
-                                    returnTypeRef = valueParameter.type.toFirJavaTypeRef(),
-                                    isVararg = valueParameter.isVararg
-                                )
-                            }
-                        }
-                        firClass.declarations += memberFunction
-                    }
-                }
-                for (declaration in firClass.declarations) {
-                    if (declaration is FirNamedFunction) {
-                        val methodId = CallableId(callableId.packageName, callableId.className, declaration.name)
-                        if (methodId == callableId) {
-                            val symbol = declaration.symbol as ConeCallableSymbol
-                            callableSymbols += symbol
-                        }
+            for (declaration in firClass.declarations) {
+                if (declaration is FirNamedFunction) {
+                    val methodId = CallableId(callableId.packageName, callableId.className, declaration.name)
+                    if (methodId == callableId) {
+                        val symbol = declaration.symbol as ConeCallableSymbol
+                        callableSymbols += symbol
                     }
                 }
             }
@@ -254,14 +70,46 @@ class JavaSymbolProvider(
                 FirJavaClass(
                     session, firSymbol as FirClassSymbol, javaClass.name,
                     javaClass.visibility, javaClass.modality,
-                    javaClass.classKind, javaClass.isStatic
+                    javaClass.classKind,
+                    isTopLevel = classId.relativeClassName.parent().isRoot, isStatic = javaClass.isStatic
                 ).apply {
                     for (typeParameter in javaClass.typeParameters) {
-                        typeParameters += createTypeParameterSymbol(typeParameter.name).fir
+                        typeParameters += createTypeParameterSymbol(session, typeParameter.name).fir
                     }
                     addAnnotationsFrom(javaClass)
                     for (supertype in javaClass.supertypes) {
-                        superTypeRefs += supertype.toFirResolvedTypeRef()
+                        superTypeRefs += supertype.toFirResolvedTypeRef(session)
+                    }
+                    // TODO: fields
+                    // TODO: may be we can process methods later.
+                    // However, they should be built up to override resolve stage
+                    for (javaMethod in javaClass.methods) {
+                        if (javaMethod.isStatic) continue // TODO: statics
+                        val methodName = javaMethod.name
+                        val methodId = CallableId(classId.packageFqName, classId.relativeClassName, methodName)
+                        val methodSymbol = FirFunctionSymbol(methodId)
+                        val returnType = javaMethod.returnType
+                        val firJavaMethod = FirJavaMethod(
+                            session, methodSymbol, methodName,
+                            javaMethod.visibility, javaMethod.modality,
+                            returnTypeRef = returnType.toFirJavaTypeRef(session)
+                        ).apply {
+                            for (typeParameter in javaMethod.typeParameters) {
+                                typeParameters += createTypeParameterSymbol(session, typeParameter.name).fir
+                            }
+                            addAnnotationsFrom(javaMethod)
+                            for (valueParameter in javaMethod.valueParameters) {
+                                val parameterType = valueParameter.type
+                                valueParameters += FirJavaValueParameter(
+                                    session, valueParameter.name ?: Name.special("<anonymous Java parameter>"),
+                                    returnTypeRef = parameterType.toFirJavaTypeRef(session),
+                                    isVararg = valueParameter.isVararg
+                                ).apply {
+                                    addAnnotationsFrom(valueParameter)
+                                }
+                            }
+                        }
+                        declarations += firJavaMethod
                     }
                 }
             }
@@ -275,5 +123,12 @@ class JavaSymbolProvider(
             FqName(javaPackage.qualifiedName)
         }
     }
+
+    fun getJavaTopLevelClasses(): List<FirRegularClass> {
+        return classCache.values
+            .filterIsInstance<FirClassSymbol>()
+            .filter { it.classId.relativeClassName.parent().isRoot }
+            .map { it.fir }
+    }
 }
 

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/JavaUtils.kt

@@ -7,8 +7,31 @@ package org.jetbrains.kotlin.fir.java
 
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.Modality
-import org.jetbrains.kotlin.load.java.structure.JavaClass
-import org.jetbrains.kotlin.load.java.structure.JavaModifierListOwner
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.declarations.impl.FirTypeParameterImpl
+import org.jetbrains.kotlin.fir.expressions.FirAnnotationCall
+import org.jetbrains.kotlin.fir.expressions.FirArrayOfCall
+import org.jetbrains.kotlin.fir.expressions.FirExpression
+import org.jetbrains.kotlin.fir.expressions.impl.*
+import org.jetbrains.kotlin.fir.java.types.FirJavaTypeRef
+import org.jetbrains.kotlin.fir.references.FirErrorNamedReference
+import org.jetbrains.kotlin.fir.references.FirResolvedCallableReferenceImpl
+import org.jetbrains.kotlin.fir.resolve.FirSymbolProvider
+import org.jetbrains.kotlin.fir.service
+import org.jetbrains.kotlin.fir.symbols.CallableId
+import org.jetbrains.kotlin.fir.symbols.ConeClassLikeLookupTagImpl
+import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirTypeParameterSymbol
+import org.jetbrains.kotlin.fir.types.*
+import org.jetbrains.kotlin.fir.types.impl.ConeClassTypeImpl
+import org.jetbrains.kotlin.fir.types.impl.ConeTypeParameterTypeImpl
+import org.jetbrains.kotlin.fir.types.impl.FirResolvedTypeRefImpl
+import org.jetbrains.kotlin.ir.expressions.IrConstKind
+import org.jetbrains.kotlin.load.java.structure.*
+import org.jetbrains.kotlin.name.ClassId
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.types.Variance
 
 internal val JavaModifierListOwner.modality: Modality
     get() = when {
@@ -24,3 +47,210 @@ internal val JavaClass.classKind: ClassKind
         isEnum -> ClassKind.ENUM_CLASS
         else -> ClassKind.CLASS
     }
+
+internal fun ClassId.toConeKotlinType(
+    typeArguments: Array<ConeKotlinTypeProjection>,
+    isNullable: Boolean
+): ConeLookupTagBasedType {
+    val lookupTag = ConeClassLikeLookupTagImpl(this)
+    return ConeClassTypeImpl(lookupTag, typeArguments, isNullable)
+}
+
+internal fun FirTypeRef.toNotNullConeKotlinType(): ConeKotlinType =
+    when (this) {
+        is FirResolvedTypeRef -> type
+        is FirJavaTypeRef -> {
+            val javaType = type
+            javaType.toNotNullConeKotlinType(session)
+        }
+        else -> ConeKotlinErrorType("Unexpected type reference in JavaClassUseSiteScope: ${this::class.java}")
+    }
+
+internal fun JavaType.toNotNullConeKotlinType(session: FirSession): ConeLookupTagBasedType {
+    return toConeKotlinTypeWithNullability(session, isNullable = false)
+}
+
+internal fun JavaType.toFirJavaTypeRef(session: FirSession): FirJavaTypeRef {
+    val annotations = (this as? JavaClassifierType)?.annotations.orEmpty()
+    return FirJavaTypeRef(session, annotations = annotations.map { it.toFirAnnotationCall(session) }, type = this)
+}
+
+internal fun JavaClassifierType.toFirResolvedTypeRef(session: FirSession): FirResolvedTypeRef {
+    val coneType = this.toConeKotlinTypeWithNullability(session, isNullable = false)
+    return FirResolvedTypeRefImpl(
+        session, psi = null, type = coneType,
+        isMarkedNullable = false, annotations = annotations.map { it.toFirAnnotationCall(session) }
+    )
+}
+
+internal fun JavaType.toConeKotlinTypeWithNullability(session: FirSession, isNullable: Boolean): ConeLookupTagBasedType {
+    return when (this) {
+        is JavaClassifierType -> {
+            toConeKotlinTypeWithNullability(session, isNullable)
+        }
+        is JavaPrimitiveType -> {
+            val primitiveType = type
+            val kotlinPrimitiveName = when (val javaName = primitiveType?.typeName?.asString()) {
+                null -> "Unit"
+                else -> javaName.capitalize()
+            }
+            val classId = ClassId(FqName("kotlin"), FqName(kotlinPrimitiveName), false)
+            classId.toConeKotlinType(emptyArray(), isNullable)
+        }
+        is JavaArrayType -> {
+            val componentType = componentType
+            if (componentType !is JavaPrimitiveType) {
+                val classId = ClassId(FqName("kotlin"), FqName("Array"), false)
+                val argumentType = ConeFlexibleType(
+                    componentType.toConeKotlinTypeWithNullability(session, isNullable = false),
+                    componentType.toConeKotlinTypeWithNullability(session, isNullable = true)
+                )
+                classId.toConeKotlinType(arrayOf(argumentType), isNullable)
+            } else {
+                val javaComponentName = componentType.type?.typeName?.asString()?.capitalize() ?: error("Array of voids")
+                val classId = ClassId(FqName("kotlin"), FqName(javaComponentName + "Array"), false)
+                classId.toConeKotlinType(emptyArray(), isNullable)
+            }
+        }
+        is JavaWildcardType -> bound?.toNotNullConeKotlinType(session) ?: run {
+            val classId = ClassId(FqName("kotlin"), FqName("Any"), false)
+            classId.toConeKotlinType(emptyArray(), isNullable)
+        }
+        else -> error("Strange JavaType: ${this::class.java}")
+    }
+}
+
+internal fun JavaClassifierType.toConeKotlinTypeWithNullability(session: FirSession, isNullable: Boolean): ConeLookupTagBasedType {
+    return when (val classifier = classifier) {
+        is JavaClass -> {
+            classifier.classId!!.toConeKotlinType(typeArguments.map { it.toConeProjection(session) }.toTypedArray(), isNullable)
+        }
+        is JavaTypeParameter -> {
+            // TODO: it's unclear how to identify type parameter by the symbol
+            // TODO: some type parameter cache (provider?)
+            val symbol = createTypeParameterSymbol(session, classifier.name)
+            ConeTypeParameterTypeImpl(symbol, isNullable)
+        }
+        else -> ConeClassErrorType(reason = "Unexpected classifier: $classifier")
+    }
+}
+
+internal fun createTypeParameterSymbol(session: FirSession, name: Name): FirTypeParameterSymbol {
+    val firSymbol = FirTypeParameterSymbol()
+    FirTypeParameterImpl(session, null, firSymbol, name, variance = Variance.INVARIANT, isReified = false)
+    return firSymbol
+}
+
+internal fun JavaAnnotation.toFirAnnotationCall(session: FirSession): FirAnnotationCall {
+    return FirAnnotationCallImpl(
+        session, psi = null, useSiteTarget = null,
+        annotationTypeRef = FirResolvedTypeRefImpl(
+            session = session,
+            psi = null,
+            type = ConeClassTypeImpl(FirClassSymbol(classId!!).toLookupTag(), emptyArray(), isNullable = false),
+            isMarkedNullable = true,
+            annotations = emptyList()
+        )
+    ).apply {
+        for (argument in this@toFirAnnotationCall.arguments) {
+            arguments += argument.toFirExpression(session)
+        }
+    }
+}
+
+internal fun FirAbstractAnnotatedElement.addAnnotationsFrom(javaAnnotationOwner: JavaAnnotationOwner) {
+    for (annotation in javaAnnotationOwner.annotations) {
+        annotations += annotation.toFirAnnotationCall(session)
+    }
+}
+
+private fun JavaType.toConeProjection(session: FirSession): ConeKotlinTypeProjection {
+    if (this is JavaClassifierType) {
+        return toConeKotlinTypeWithNullability(session, isNullable = false)
+    }
+    return ConeClassErrorType("Unexpected type argument: $this")
+}
+
+private fun JavaAnnotationArgument.toFirExpression(session: FirSession): FirExpression {
+    // TODO: this.name
+    return when (this) {
+        is JavaLiteralAnnotationArgument -> {
+            when (val value = value) {
+                is ByteArray -> value.toList().createArrayOfCall(session, IrConstKind.Byte)
+                is ShortArray -> value.toList().createArrayOfCall(session, IrConstKind.Short)
+                is IntArray -> value.toList().createArrayOfCall(session, IrConstKind.Int)
+                is LongArray -> value.toList().createArrayOfCall(session, IrConstKind.Long)
+                is CharArray -> value.toList().createArrayOfCall(session, IrConstKind.Char)
+                is FloatArray -> value.toList().createArrayOfCall(session, IrConstKind.Float)
+                is DoubleArray -> value.toList().createArrayOfCall(session, IrConstKind.Double)
+                is BooleanArray -> value.toList().createArrayOfCall(session, IrConstKind.Boolean)
+                else -> value.createConstant(session)
+            }
+        }
+        is JavaArrayAnnotationArgument -> FirArrayOfCallImpl(session, null).apply {
+            for (element in getElements()) {
+                arguments += element.toFirExpression(session)
+            }
+        }
+        is JavaEnumValueAnnotationArgument -> {
+            FirFunctionCallImpl(session, null).apply {
+                val classId = this@toFirExpression.enumClassId
+                val entryName = this@toFirExpression.entryName
+                val calleeReference = if (classId != null && entryName != null) {
+                    val callableSymbol = session.service<FirSymbolProvider>().getCallableSymbols(
+                        CallableId(classId.packageFqName, classId.relativeClassName, entryName)
+                    ).firstOrNull()
+                    callableSymbol?.let {
+                        FirResolvedCallableReferenceImpl(session, null, entryName, it)
+                    }
+                } else {
+                    null
+                }
+                this.calleeReference = calleeReference
+                    ?: FirErrorNamedReference(session, null, "Strange Java enum value: ${this@toFirExpression}")
+            }
+        }
+        is JavaClassObjectAnnotationArgument -> FirGetClassCallImpl(session, null).apply {
+            val referencedType = getReferencedType()
+            arguments += FirClassReferenceExpressionImpl(session, null, referencedType.toFirResolvedTypeRef(session))
+        }
+        is JavaAnnotationAsAnnotationArgument -> getAnnotation().toFirAnnotationCall(session)
+        else -> FirErrorExpressionImpl(session, null, "Unknown JavaAnnotationArgument: ${this::class.java}")
+    }
+}
+
+// TODO: use kind here
+private fun <T> List<T>.createArrayOfCall(session: FirSession, @Suppress("UNUSED_PARAMETER") kind: IrConstKind<T>): FirArrayOfCall {
+    return FirArrayOfCallImpl(session, null).apply {
+        for (element in this@createArrayOfCall) {
+            arguments += element.createConstant(session)
+        }
+    }
+}
+
+private fun Any?.createConstant(session: FirSession): FirExpression {
+    return when (this) {
+        is Byte -> FirConstExpressionImpl(session, null, IrConstKind.Byte, this)
+        is Short -> FirConstExpressionImpl(session, null, IrConstKind.Short, this)
+        is Int -> FirConstExpressionImpl(session, null, IrConstKind.Int, this)
+        is Long -> FirConstExpressionImpl(session, null, IrConstKind.Long, this)
+        is Char -> FirConstExpressionImpl(session, null, IrConstKind.Char, this)
+        is Float -> FirConstExpressionImpl(session, null, IrConstKind.Float, this)
+        is Double -> FirConstExpressionImpl(session, null, IrConstKind.Double, this)
+        is Boolean -> FirConstExpressionImpl(session, null, IrConstKind.Boolean, this)
+        is String -> FirConstExpressionImpl(session, null, IrConstKind.String, this)
+        null -> FirConstExpressionImpl(session, null, IrConstKind.Null, null)
+
+        else -> FirErrorExpressionImpl(session, null, "Unknown value in JavaLiteralAnnotationArgument: $this")
+    }
+}
+
+private fun JavaType.toFirResolvedTypeRef(session: FirSession): FirResolvedTypeRef {
+    if (this is JavaClassifierType) return toFirResolvedTypeRef(session)
+    return FirResolvedTypeRefImpl(
+        session, psi = null, type = ConeClassErrorType("Unexpected JavaType: $this"),
+        isMarkedNullable = false, annotations = emptyList()
+    )
+}
+
+

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/declarations/FirJavaClass.kt

@@ -5,26 +5,72 @@
 
 package org.jetbrains.kotlin.fir.java.declarations
 
-import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibility
 import org.jetbrains.kotlin.fir.FirSession
-import org.jetbrains.kotlin.fir.declarations.impl.FirClassImpl
+import org.jetbrains.kotlin.fir.declarations.FirDeclaration
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.declarations.impl.FirAbstractMemberDeclaration
+import org.jetbrains.kotlin.fir.declarations.impl.FirModifiableClass
+import org.jetbrains.kotlin.fir.java.scopes.JavaClassEnhancementScope
+import org.jetbrains.kotlin.fir.java.scopes.JavaClassUseSiteScope
+import org.jetbrains.kotlin.fir.resolve.lookupSuperTypes
+import org.jetbrains.kotlin.fir.resolve.toSymbol
+import org.jetbrains.kotlin.fir.scopes.impl.FirClassDeclaredMemberScope
+import org.jetbrains.kotlin.fir.scopes.impl.FirCompositeScope
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
+import org.jetbrains.kotlin.fir.types.ConeClassErrorType
+import org.jetbrains.kotlin.fir.types.FirTypeRef
 import org.jetbrains.kotlin.name.Name
 
 class FirJavaClass(
     session: FirSession,
-    symbol: FirClassSymbol,
+    override val symbol: FirClassSymbol,
     name: Name,
     visibility: Visibility,
     modality: Modality?,
-    classKind: ClassKind,
+    override val classKind: ClassKind,
+    isTopLevel: Boolean,
     isStatic: Boolean
-) : FirClassImpl(
-    session, psi = null, symbol = symbol, name = name,
+) : FirAbstractMemberDeclaration(
+    session, psi = null, name = name,
     visibility = visibility, modality = modality,
-    isExpect = false, isActual = false, classKind = classKind, isInner = !isStatic,
-    isCompanion = false, isData = false, isInline = false
-)
+    isExpect = false, isActual = false
+), FirRegularClass, FirModifiableClass {
+    init {
+        symbol.bind(this)
+        status.isInner = !isTopLevel && !isStatic
+        status.isCompanion = false
+        status.isData = false
+        status.isInline = false
+    }
+
+    override val superTypeRefs = mutableListOf<FirTypeRef>()
+
+    val useSiteScope: JavaClassUseSiteScope by lazy { buildUseSiteScope() }
+
+    override val declarations = mutableListOf<FirDeclaration>()
+
+    private fun FirRegularClass.buildUseSiteScope(useSiteSession: FirSession = session): JavaClassUseSiteScope {
+        val superTypeEnhancementScope = FirCompositeScope(mutableListOf())
+        val declaredScope = FirClassDeclaredMemberScope(this, useSiteSession)
+        lookupSuperTypes(this, lookupInterfaces = true, deep = false, useSiteSession = useSiteSession)
+            .mapNotNullTo(superTypeEnhancementScope.scopes) { useSiteSuperType ->
+                if (useSiteSuperType is ConeClassErrorType) return@mapNotNullTo null
+                val symbol = useSiteSuperType.lookupTag.toSymbol(useSiteSession)
+                if (symbol is FirClassSymbol) {
+                    JavaClassEnhancementScope(useSiteSession, symbol.fir.buildUseSiteScope(useSiteSession))
+                } else {
+                    null
+                }
+            }
+        return JavaClassUseSiteScope(this, useSiteSession, superTypeEnhancementScope, declaredScope)
+    }
+
+    override fun replaceSupertypes(newSupertypes: List<FirTypeRef>): FirRegularClass {
+        superTypeRefs.clear()
+        superTypeRefs.addAll(newSupertypes)
+        return this
+    }
+}

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/declarations/FirJavaMethod.kt

@@ -25,7 +25,7 @@ class FirJavaMethod(
     session, null, symbol, name,
     visibility, modality,
     false, isActual = false,
-    isOverride = false, // TODO: really it's unknown whether Java methods are overrides or not
+    isOverride = false,
     isOperator = true, // All Java methods with name that allows to use it in operator form are considered operators
     isInfix = false, isInline = false, isTailRec = false, isExternal = false, isSuspend = false,
     receiverTypeRef = null, returnTypeRef = returnTypeRef

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/EnhancementSignatureParts.kt

@@ -0,0 +1,293 @@
+/*
+ * 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.fir.java.enhancement
+
+import org.jetbrains.kotlin.builtins.jvm.JavaToKotlinClassMap
+import org.jetbrains.kotlin.fir.declarations.FirValueParameter
+import org.jetbrains.kotlin.fir.expressions.FirAnnotationCall
+import org.jetbrains.kotlin.fir.expressions.FirAnnotationContainer
+import org.jetbrains.kotlin.fir.expressions.resolvedFqName
+import org.jetbrains.kotlin.fir.java.toConeKotlinTypeWithNullability
+import org.jetbrains.kotlin.fir.java.toFirJavaTypeRef
+import org.jetbrains.kotlin.fir.java.toNotNullConeKotlinType
+import org.jetbrains.kotlin.fir.java.types.FirJavaTypeRef
+import org.jetbrains.kotlin.fir.symbols.ConeClassLikeLookupTag
+import org.jetbrains.kotlin.fir.types.*
+import org.jetbrains.kotlin.load.java.AnnotationTypeQualifierResolver
+import org.jetbrains.kotlin.load.java.MUTABLE_ANNOTATIONS
+import org.jetbrains.kotlin.load.java.READ_ONLY_ANNOTATIONS
+import org.jetbrains.kotlin.load.java.structure.JavaWildcardType
+import org.jetbrains.kotlin.load.java.typeEnhancement.*
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.FqNameUnsafe
+import org.jetbrains.kotlin.utils.Jsr305State
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
+
+internal class EnhancementSignatureParts(
+    private val typeQualifierResolver: FirAnnotationTypeQualifierResolver,
+    private val typeContainer: FirAnnotationContainer?,
+    private val current: FirJavaTypeRef,
+    private val fromOverridden: Collection<FirTypeRef>,
+    private val isCovariant: Boolean,
+    private val context: FirJavaEnhancementContext,
+    private val containerApplicabilityType: AnnotationTypeQualifierResolver.QualifierApplicabilityType
+) {
+    private val isForVarargParameter get() = typeContainer.safeAs<FirValueParameter>()?.isVararg == true
+
+    private fun ConeKotlinType.toFqNameUnsafe(): FqNameUnsafe? =
+        ((this as? ConeLookupTagBasedType)?.lookupTag as? ConeClassLikeLookupTag)?.classId?.asSingleFqName()?.toUnsafe()
+
+    internal fun enhance(
+        jsr305State: Jsr305State,
+        predefined: TypeEnhancementInfo? = null
+    ): PartEnhancementResult {
+        val qualifiers = computeIndexedQualifiersForOverride(jsr305State)
+
+        val qualifiersWithPredefined: ((Int) -> JavaTypeQualifiers)? = predefined?.let {
+            { index ->
+                predefined.map[index] ?: qualifiers(index)
+            }
+        }
+
+        val containsFunctionN = current.toNotNullConeKotlinType().contains {
+            val classId = it.lookupTag.classId
+            classId.shortClassName == JavaToKotlinClassMap.FUNCTION_N_FQ_NAME.shortName() &&
+                    classId.asSingleFqName() == JavaToKotlinClassMap.FUNCTION_N_FQ_NAME
+        }
+
+        val enhancedCurrent = current.enhance(qualifiersWithPredefined ?: qualifiers)
+        return PartEnhancementResult(
+            enhancedCurrent, wereChanges = true, containsFunctionN = containsFunctionN
+        )
+    }
+
+    private fun ConeKotlinType.contains(isSpecialType: (ConeClassLikeType) -> Boolean): Boolean {
+        return when (this) {
+            is ConeClassLikeType -> isSpecialType(this)
+            else -> false
+        }
+    }
+
+
+    private fun FirTypeRef.toIndexed(
+        typeQualifierResolver: FirAnnotationTypeQualifierResolver,
+        jsr305State: Jsr305State,
+        context: FirJavaEnhancementContext
+    ): List<TypeAndDefaultQualifiers> {
+        val list = ArrayList<TypeAndDefaultQualifiers>(1)
+
+        fun add(type: FirTypeRef) {
+            val c = context.copyWithNewDefaultTypeQualifiers(typeQualifierResolver, jsr305State, type.annotations)
+
+            list.add(
+                TypeAndDefaultQualifiers(
+                    type,
+                    c.defaultTypeQualifiers
+                        ?.get(AnnotationTypeQualifierResolver.QualifierApplicabilityType.TYPE_USE)
+                )
+            )
+
+            if (type is FirJavaTypeRef) {
+                for (arg in type.type.typeArguments()) {
+                    if (arg is JavaWildcardType) {
+                        // TODO: wildcards
+                    } else {
+                        add(arg.toFirJavaTypeRef(context.session))
+                    }
+                }
+            } else {
+                for (arg in type.typeArguments()) {
+                    if (arg is FirStarProjection) {
+                        // TODO: wildcards
+                    } else if (arg is FirTypeProjectionWithVariance) {
+                        add(arg.typeRef)
+                    }
+                }
+            }
+        }
+
+        add(this)
+        return list
+    }
+
+    private fun extractQualifiers(lower: ConeKotlinType, upper: ConeKotlinType): JavaTypeQualifiers {
+        val mapping = JavaToKotlinClassMap
+        return JavaTypeQualifiers(
+            when {
+                lower.isMarkedNullable -> NullabilityQualifier.NULLABLE
+                !upper.isMarkedNullable -> NullabilityQualifier.NOT_NULL
+                else -> null
+            },
+            when {
+                mapping.isReadOnly(lower.toFqNameUnsafe()) -> MutabilityQualifier.READ_ONLY
+                mapping.isMutable(upper.toFqNameUnsafe()) -> MutabilityQualifier.MUTABLE
+                else -> null
+            },
+            isNotNullTypeParameter = false //TODO: unwrap() is NotNullTypeParameter
+        )
+    }
+
+    private fun FirTypeRef.extractQualifiers(): JavaTypeQualifiers {
+        val (lower, upper) = when (this) {
+            is FirResolvedTypeRef -> {
+                val type = this.type
+                if (type is ConeFlexibleType) {
+                    Pair(type.lowerBound, type.upperBound)
+                } else {
+                    Pair(type, type)
+                }
+            }
+            is FirJavaTypeRef -> {
+                Pair(
+                    // TODO: optimize
+                    type.toConeKotlinTypeWithNullability(session, isNullable = false),
+                    type.toConeKotlinTypeWithNullability(session, isNullable = true)
+                )
+            }
+            else -> return JavaTypeQualifiers.NONE
+        }
+
+        return extractQualifiers(lower, upper)
+    }
+
+    private fun composeAnnotations(first: List<FirAnnotationCall>, second: List<FirAnnotationCall>): List<FirAnnotationCall> {
+        return when {
+            first.isEmpty() -> second
+            second.isEmpty() -> first
+            else -> first + second
+        }
+    }
+
+    private fun FirTypeRef.extractQualifiersFromAnnotations(
+        isHeadTypeConstructor: Boolean,
+        defaultQualifiersForType: JavaTypeQualifiers?,
+        jsr305State: Jsr305State
+    ): JavaTypeQualifiers {
+        val composedAnnotation =
+            if (isHeadTypeConstructor && typeContainer != null)
+                composeAnnotations(typeContainer.annotations, annotations)
+            else
+                annotations
+
+        fun <T : Any> List<FqName>.ifPresent(qualifier: T) =
+            if (any { fqName ->
+                    composedAnnotation.any { it.resolvedFqName == fqName }
+                }
+            ) qualifier else null
+
+        fun <T : Any> uniqueNotNull(x: T?, y: T?) = if (x == null || y == null || x == y) x ?: y else null
+
+        val defaultTypeQualifier =
+            if (isHeadTypeConstructor)
+                context.defaultTypeQualifiers?.get(containerApplicabilityType)
+            else
+                defaultQualifiersForType
+
+        val nullabilityInfo = composedAnnotation.extractNullability(typeQualifierResolver, jsr305State)
+            ?: defaultTypeQualifier?.nullability?.let { nullability ->
+                NullabilityQualifierWithMigrationStatus(
+                    nullability,
+                    defaultTypeQualifier.isNullabilityQualifierForWarning
+                )
+            }
+
+        @Suppress("SimplifyBooleanWithConstants")
+        return JavaTypeQualifiers(
+            nullabilityInfo?.qualifier,
+            uniqueNotNull(
+                READ_ONLY_ANNOTATIONS.ifPresent(
+                    MutabilityQualifier.READ_ONLY
+                ),
+                MUTABLE_ANNOTATIONS.ifPresent(
+                    MutabilityQualifier.MUTABLE
+                )
+            ),
+            isNotNullTypeParameter = nullabilityInfo?.qualifier == NullabilityQualifier.NOT_NULL && true, /* TODO: isTypeParameter()*/
+            isNullabilityQualifierForWarning = nullabilityInfo?.isForWarningOnly == true
+        )
+    }
+
+    private fun FirTypeRef.computeQualifiersForOverride(
+        fromSupertypes: Collection<FirTypeRef>,
+        defaultQualifiersForType: JavaTypeQualifiers?,
+        isHeadTypeConstructor: Boolean,
+        jsr305State: Jsr305State
+    ): JavaTypeQualifiers {
+        val superQualifiers = fromSupertypes.map { it.extractQualifiers() }
+        val mutabilityFromSupertypes = superQualifiers.mapNotNull { it.mutability }.toSet()
+        val nullabilityFromSupertypes = superQualifiers.mapNotNull { it.nullability }.toSet()
+        val nullabilityFromSupertypesWithWarning = fromOverridden
+            .mapNotNull { it.extractQualifiers().nullability }
+            .toSet()
+
+        val own = extractQualifiersFromAnnotations(isHeadTypeConstructor, defaultQualifiersForType, jsr305State)
+        val ownNullability = own.takeIf { !it.isNullabilityQualifierForWarning }?.nullability
+        val ownNullabilityForWarning = own.nullability
+
+        val isCovariantPosition = isCovariant && isHeadTypeConstructor
+        val nullability =
+            nullabilityFromSupertypes.select(ownNullability, isCovariantPosition)
+                // Vararg value parameters effectively have non-nullable type in Kotlin
+                // and having nullable types in Java may lead to impossibility of overriding them in Kotlin
+                ?.takeUnless { isForVarargParameter && isHeadTypeConstructor && it == NullabilityQualifier.NULLABLE }
+
+        val mutability =
+            mutabilityFromSupertypes
+                .select(MutabilityQualifier.MUTABLE, MutabilityQualifier.READ_ONLY, own.mutability, isCovariantPosition)
+
+        val canChange = ownNullabilityForWarning != ownNullability || nullabilityFromSupertypesWithWarning != nullabilityFromSupertypes
+        val isAnyNonNullTypeParameter = own.isNotNullTypeParameter || superQualifiers.any { it.isNotNullTypeParameter }
+        if (nullability == null && canChange) {
+            val nullabilityWithWarning =
+                nullabilityFromSupertypesWithWarning.select(ownNullabilityForWarning, isCovariantPosition)
+
+            return createJavaTypeQualifiers(
+                nullabilityWithWarning, mutability,
+                forWarning = true, isAnyNonNullTypeParameter = isAnyNonNullTypeParameter
+            )
+        }
+
+        return createJavaTypeQualifiers(
+            nullability, mutability,
+            forWarning = nullability == null,
+            isAnyNonNullTypeParameter = isAnyNonNullTypeParameter
+        )
+    }
+
+    private fun computeIndexedQualifiersForOverride(jsr305State: Jsr305State): (Int) -> JavaTypeQualifiers {
+        val indexedFromSupertypes = fromOverridden.map { it.toIndexed(typeQualifierResolver, jsr305State, context) }
+        val indexedThisType = current.toIndexed(typeQualifierResolver, jsr305State, context)
+
+        // The covariant case may be hard, e.g. in the superclass the return may be Super<T>, but in the subclass it may be Derived, which
+        // is declared to extend Super<T>, and propagating data here is highly non-trivial, so we only look at the head type constructor
+        // (outermost type), unless the type in the subclass is interchangeable with the all the types in superclasses:
+        // e.g. we have (Mutable)List<String!>! in the subclass and { List<String!>, (Mutable)List<String>! } from superclasses
+        // Note that `this` is flexible here, so it's equal to it's bounds
+        val onlyHeadTypeConstructor = isCovariant && fromOverridden.any { true /*equalTypes(it, this)*/ }
+
+        val treeSize = if (onlyHeadTypeConstructor) 1 else indexedThisType.size
+        val computedResult = Array(treeSize) { index ->
+            val isHeadTypeConstructor = index == 0
+            assert(isHeadTypeConstructor || !onlyHeadTypeConstructor) { "Only head type constructors should be computed" }
+
+            val (qualifiers, defaultQualifiers) = indexedThisType[index]
+            val verticalSlice = indexedFromSupertypes.mapNotNull { it.getOrNull(index)?.type }
+
+            // Only the head type constructor is safely co-variant
+            qualifiers.computeQualifiersForOverride(verticalSlice, defaultQualifiers, isHeadTypeConstructor, jsr305State)
+        }
+
+        return { index -> computedResult.getOrElse(index) { JavaTypeQualifiers.NONE } }
+    }
+
+    @Suppress("unused")
+    internal open class PartEnhancementResult(
+        val type: FirResolvedTypeRef,
+        val wereChanges: Boolean,
+        val containsFunctionN: Boolean
+    )
+}
+

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/FirAnnotationTypeQualifierResolver.kt

@@ -0,0 +1,157 @@
+/*
+ * 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.fir.java.enhancement
+
+import org.jetbrains.kotlin.descriptors.ClassKind
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.expressions.*
+import org.jetbrains.kotlin.fir.resolve.toSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
+import org.jetbrains.kotlin.fir.types.ConeClassLikeType
+import org.jetbrains.kotlin.fir.types.FirResolvedTypeRef
+import org.jetbrains.kotlin.load.java.*
+import org.jetbrains.kotlin.load.java.lazy.NullabilityQualifierWithApplicability
+import org.jetbrains.kotlin.utils.Jsr305State
+import org.jetbrains.kotlin.utils.ReportLevel
+import org.jetbrains.kotlin.utils.addToStdlib.firstNotNullResult
+
+class FirAnnotationTypeQualifierResolver(private val jsr305State: Jsr305State) {
+
+    class TypeQualifierWithApplicability(
+        private val typeQualifier: FirAnnotationCall,
+        private val applicability: Int
+    ) {
+        operator fun component1() = typeQualifier
+        operator fun component2() = AnnotationTypeQualifierResolver.QualifierApplicabilityType.values().filter(this::isApplicableTo)
+
+        private fun isApplicableTo(elementType: AnnotationTypeQualifierResolver.QualifierApplicabilityType) =
+            isApplicableConsideringMask(AnnotationTypeQualifierResolver.QualifierApplicabilityType.TYPE_USE) || isApplicableConsideringMask(
+                elementType
+            )
+
+        private fun isApplicableConsideringMask(elementType: AnnotationTypeQualifierResolver.QualifierApplicabilityType) =
+            (applicability and (1 shl elementType.ordinal)) != 0
+    }
+
+    // TODO: memoize this function
+    private fun computeTypeQualifierNickname(klass: FirRegularClass): FirAnnotationCall? {
+        if (klass.annotations.none { it.resolvedFqName == TYPE_QUALIFIER_NICKNAME_FQNAME }) return null
+
+        return klass.annotations.firstNotNullResult(this::resolveTypeQualifierAnnotation)
+    }
+
+    private fun resolveTypeQualifierNickname(klass: FirRegularClass): FirAnnotationCall? {
+        if (klass.classKind != ClassKind.ANNOTATION_CLASS) return null
+
+        return computeTypeQualifierNickname(klass)
+    }
+
+    private val FirAnnotationCall.resolvedClass: FirRegularClass?
+        get() {
+            val lookupTag = ((annotationTypeRef as? FirResolvedTypeRef)?.type as? ConeClassLikeType)?.lookupTag
+            return (lookupTag?.toSymbol(session) as? FirClassSymbol)?.fir
+        }
+
+    fun resolveTypeQualifierAnnotation(annotationCall: FirAnnotationCall): FirAnnotationCall? {
+        if (jsr305State.disabled) {
+            return null
+        }
+
+        val annotationClass = annotationCall.resolvedClass ?: return null
+        if (annotationClass.isAnnotatedWithTypeQualifier) return annotationCall
+
+        return resolveTypeQualifierNickname(annotationClass)
+    }
+
+    fun resolveQualifierBuiltInDefaultAnnotation(annotationCall: FirAnnotationCall): NullabilityQualifierWithApplicability? {
+        if (jsr305State.disabled) {
+            return null
+        }
+
+        return BUILT_IN_TYPE_QUALIFIER_DEFAULT_ANNOTATIONS[annotationCall.resolvedFqName]?.let { (qualifier, applicability) ->
+            val state = resolveJsr305ReportLevel(annotationCall).takeIf { it != ReportLevel.IGNORE } ?: return null
+            return NullabilityQualifierWithApplicability(qualifier.copy(isForWarningOnly = state.isWarning), applicability)
+        }
+    }
+
+    fun resolveTypeQualifierDefaultAnnotation(annotationCall: FirAnnotationCall): TypeQualifierWithApplicability? {
+        if (jsr305State.disabled) {
+            return null
+        }
+
+        val typeQualifierDefaultAnnotatedClass =
+            annotationCall.resolvedClass?.takeIf { klass ->
+                klass.annotations.any { it.resolvedFqName == TYPE_QUALIFIER_DEFAULT_FQNAME }
+            } ?: return null
+
+        val elementTypesMask =
+            annotationCall.resolvedClass!!
+                .annotations.find { it.resolvedFqName == TYPE_QUALIFIER_DEFAULT_FQNAME }!!
+                .arguments
+                .flatMap { argument ->
+                    // TODO: replace after implementation of KT-24081
+                    if (true /*parameter == JvmAnnotationNames.DEFAULT_ANNOTATION_MEMBER_NAME*/)
+                        argument.mapConstantToQualifierApplicabilityTypes()
+                    else
+                        emptyList()
+                }
+                .fold(0) { acc: Int, applicabilityType -> acc or (1 shl applicabilityType.ordinal) }
+
+        val typeQualifier = typeQualifierDefaultAnnotatedClass.annotations.firstOrNull { resolveTypeQualifierAnnotation(it) != null }
+            ?: return null
+
+        return TypeQualifierWithApplicability(
+            typeQualifier,
+            elementTypesMask
+        )
+    }
+
+    fun resolveJsr305ReportLevel(annotationCall: FirAnnotationCall): ReportLevel {
+        resolveJsr305CustomLevel(annotationCall)?.let { return it }
+        return jsr305State.global
+    }
+
+    fun resolveJsr305CustomLevel(annotationCall: FirAnnotationCall): ReportLevel? {
+        jsr305State.user[annotationCall.resolvedFqName?.asString()]?.let { return it }
+        return annotationCall.resolvedClass?.migrationAnnotationStatus()
+    }
+
+    private fun FirRegularClass.migrationAnnotationStatus(): ReportLevel? {
+        val enumEntryName = annotations.find {
+            it.resolvedFqName == MIGRATION_ANNOTATION_FQNAME
+        }?.arguments?.firstOrNull()?.toResolvedCallableSymbol()?.callableId?.callableName ?: return null
+
+        jsr305State.migration?.let { return it }
+
+        return when (enumEntryName.asString()) {
+            "STRICT" -> ReportLevel.STRICT
+            "WARN" -> ReportLevel.WARN
+            "IGNORE" -> ReportLevel.IGNORE
+            else -> null
+        }
+    }
+
+    private fun FirExpression.mapConstantToQualifierApplicabilityTypes(): List<AnnotationTypeQualifierResolver.QualifierApplicabilityType> =
+        when (this) {
+            is FirArrayOfCall -> arguments.flatMap { it.mapConstantToQualifierApplicabilityTypes() }
+            else -> listOfNotNull(
+                when (toResolvedCallableSymbol()?.callableId?.callableName?.asString()) {
+                    "METHOD" -> AnnotationTypeQualifierResolver.QualifierApplicabilityType.METHOD_RETURN_TYPE
+                    "FIELD" -> AnnotationTypeQualifierResolver.QualifierApplicabilityType.FIELD
+                    "PARAMETER" -> AnnotationTypeQualifierResolver.QualifierApplicabilityType.VALUE_PARAMETER
+                    "TYPE_USE" -> AnnotationTypeQualifierResolver.QualifierApplicabilityType.TYPE_USE
+                    else -> null
+                }
+            )
+        }
+
+    val disabled: Boolean = jsr305State.disabled
+
+}
+
+private val FirRegularClass.isAnnotatedWithTypeQualifier: Boolean
+    get() = this.symbol.classId.asSingleFqName() in BUILT_IN_TYPE_QUALIFIER_FQ_NAMES ||
+            annotations.any { it.resolvedFqName == TYPE_QUALIFIER_FQNAME }

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/FirJavaEnhancementContext.kt

@@ -0,0 +1,97 @@
+/*
+ * 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.fir.java.enhancement
+
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.expressions.FirAnnotationCall
+import org.jetbrains.kotlin.load.java.AnnotationTypeQualifierResolver
+import org.jetbrains.kotlin.load.java.lazy.JavaTypeQualifiersByElementType
+import org.jetbrains.kotlin.load.java.lazy.NullabilityQualifierWithApplicability
+import org.jetbrains.kotlin.load.java.lazy.QualifierByApplicabilityType
+import org.jetbrains.kotlin.utils.Jsr305State
+
+class FirJavaEnhancementContext private constructor(
+    val session: FirSession,
+    delegateForDefaultTypeQualifiers: Lazy<JavaTypeQualifiersByElementType?>
+) {
+    constructor(session: FirSession, typeQualifiersComputation: () -> JavaTypeQualifiersByElementType?) :
+            this(session, lazy(LazyThreadSafetyMode.NONE, typeQualifiersComputation))
+
+    val defaultTypeQualifiers: JavaTypeQualifiersByElementType? by delegateForDefaultTypeQualifiers
+
+    val moduleInfo get() = session.moduleInfo
+}
+
+fun extractDefaultNullabilityQualifier(
+    typeQualifierResolver: FirAnnotationTypeQualifierResolver,
+    jsr305State: Jsr305State,
+    annotationCall: FirAnnotationCall
+): NullabilityQualifierWithApplicability? {
+    typeQualifierResolver.resolveQualifierBuiltInDefaultAnnotation(annotationCall)?.let { return it }
+
+    val (typeQualifier, applicability) =
+        typeQualifierResolver.resolveTypeQualifierDefaultAnnotation(annotationCall)
+            ?: return null
+
+    val jsr305ReportLevel = with(typeQualifierResolver) {
+        resolveJsr305CustomLevel(annotationCall) ?: resolveJsr305ReportLevel(typeQualifier)
+    }
+
+    if (jsr305ReportLevel.isIgnore) {
+        return null
+    }
+
+    val nullabilityQualifier = typeQualifier.extractNullability(
+        typeQualifierResolver, jsr305State
+    )?.copy(isForWarningOnly = jsr305ReportLevel.isWarning) ?: return null
+
+    return NullabilityQualifierWithApplicability(nullabilityQualifier, applicability)
+}
+
+fun FirJavaEnhancementContext.computeNewDefaultTypeQualifiers(
+    typeQualifierResolver: FirAnnotationTypeQualifierResolver,
+    jsr305State: Jsr305State,
+    additionalAnnotations: List<FirAnnotationCall>
+): JavaTypeQualifiersByElementType? {
+    if (typeQualifierResolver.disabled) return defaultTypeQualifiers
+
+    val nullabilityQualifiersWithApplicability =
+        additionalAnnotations.mapNotNull { annotationCall ->
+            extractDefaultNullabilityQualifier(
+                typeQualifierResolver,
+                jsr305State,
+                annotationCall
+            )
+        }
+
+    if (nullabilityQualifiersWithApplicability.isEmpty()) return defaultTypeQualifiers
+
+    val nullabilityQualifiersByType =
+        defaultTypeQualifiers?.nullabilityQualifiers?.let(::QualifierByApplicabilityType)
+            ?: QualifierByApplicabilityType(AnnotationTypeQualifierResolver.QualifierApplicabilityType::class.java)
+
+    var wasUpdate = false
+    for ((nullability, applicableTo) in nullabilityQualifiersWithApplicability) {
+        for (applicabilityType in applicableTo) {
+            nullabilityQualifiersByType[applicabilityType] = nullability
+            wasUpdate = true
+        }
+    }
+
+    return if (!wasUpdate) defaultTypeQualifiers else JavaTypeQualifiersByElementType(nullabilityQualifiersByType)
+}
+
+fun FirJavaEnhancementContext.copyWithNewDefaultTypeQualifiers(
+    typeQualifierResolver: FirAnnotationTypeQualifierResolver,
+    jsr305State: Jsr305State,
+    additionalAnnotations: List<FirAnnotationCall>
+): FirJavaEnhancementContext =
+    when {
+        additionalAnnotations.isEmpty() -> this
+        else -> FirJavaEnhancementContext(session) {
+            computeNewDefaultTypeQualifiers(typeQualifierResolver, jsr305State, additionalAnnotations)
+        }
+    }

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/javaTypeUtils.kt

@@ -0,0 +1,206 @@
+/*
+ * 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.fir.java.enhancement
+
+import org.jetbrains.kotlin.builtins.jvm.JavaToKotlinClassMap
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.declarations.FirValueParameter
+import org.jetbrains.kotlin.fir.expressions.FirAnnotationCall
+import org.jetbrains.kotlin.fir.expressions.FirConstExpression
+import org.jetbrains.kotlin.fir.expressions.resolvedFqName
+import org.jetbrains.kotlin.fir.java.createTypeParameterSymbol
+import org.jetbrains.kotlin.fir.java.toConeKotlinTypeWithNullability
+import org.jetbrains.kotlin.fir.java.toNotNullConeKotlinType
+import org.jetbrains.kotlin.fir.java.types.FirJavaTypeRef
+import org.jetbrains.kotlin.fir.resolve.FirSymbolProvider
+import org.jetbrains.kotlin.fir.resolve.constructType
+import org.jetbrains.kotlin.fir.resolve.toTypeProjection
+import org.jetbrains.kotlin.fir.service
+import org.jetbrains.kotlin.fir.symbols.ConeClassifierSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
+import org.jetbrains.kotlin.fir.types.*
+import org.jetbrains.kotlin.fir.types.impl.FirResolvedTypeRefImpl
+import org.jetbrains.kotlin.load.java.JvmAnnotationNames
+import org.jetbrains.kotlin.load.java.descriptors.AnnotationDefaultValue
+import org.jetbrains.kotlin.load.java.descriptors.NullDefaultValue
+import org.jetbrains.kotlin.load.java.descriptors.StringDefaultValue
+import org.jetbrains.kotlin.load.java.structure.*
+import org.jetbrains.kotlin.load.java.typeEnhancement.*
+import org.jetbrains.kotlin.name.ClassId
+import org.jetbrains.kotlin.types.Variance
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
+
+internal fun FirJavaTypeRef.enhance(
+    qualifiers: (Int) -> JavaTypeQualifiers
+): FirResolvedTypeRef {
+    return type.enhancePossiblyFlexible(session, annotations, qualifiers, 0)
+}
+
+// The index in the lambda is the position of the type component:
+// Example: for `A<B, C<D, E>>`, indices go as follows: `0 - A<...>, 1 - B, 2 - C<D, E>, 3 - D, 4 - E`,
+// which corresponds to the left-to-right breadth-first walk of the tree representation of the type.
+// For flexible types, both bounds are indexed in the same way: `(A<B>..C<D>)` gives `0 - (A<B>..C<D>), 1 - B and D`.
+private fun JavaType.enhancePossiblyFlexible(
+    session: FirSession,
+    annotations: List<FirAnnotationCall>,
+    qualifiers: (Int) -> JavaTypeQualifiers,
+    index: Int
+): FirResolvedTypeRef {
+    val type = this
+    val arguments = typeArguments()
+    return when (type) {
+        is JavaClassifierType -> {
+            val lowerResult = type.enhanceInflexibleType(
+                session, annotations, arguments, TypeComponentPosition.FLEXIBLE_LOWER, qualifiers, index
+            )
+            val upperResult = type.enhanceInflexibleType(
+                session, annotations, arguments, TypeComponentPosition.FLEXIBLE_UPPER, qualifiers, index
+            )
+
+            FirResolvedTypeRefImpl(
+                session, psi = null,
+                type = ConeFlexibleType(lowerResult, upperResult),
+                isMarkedNullable = false, annotations = annotations
+            )
+        }
+        else -> {
+            val enhanced = type.toNotNullConeKotlinType(session)
+            FirResolvedTypeRefImpl(session, psi = null, type = enhanced, isMarkedNullable = false, annotations = annotations)
+        }
+    }
+}
+
+private fun JavaType.subtreeSize(): Int {
+    if (this !is JavaClassifierType) return 1
+    return 1 + typeArguments.sumBy { it.subtreeSize() }
+}
+
+private fun JavaClassifierType.enhanceInflexibleType(
+    session: FirSession,
+    annotations: List<FirAnnotationCall>,
+    arguments: List<JavaType>,
+    position: TypeComponentPosition,
+    qualifiers: (Int) -> JavaTypeQualifiers,
+    index: Int
+): ConeLookupTagBasedType {
+    val originalSymbol = when (val classifier = classifier) {
+        is JavaClass -> session.service<FirSymbolProvider>().getClassLikeSymbolByFqName(classifier.classId!!)!!
+        is JavaTypeParameter -> createTypeParameterSymbol(session, classifier.name)
+        else -> return toNotNullConeKotlinType(session)
+    }
+
+    val effectiveQualifiers = qualifiers(index)
+    val (enhancedSymbol, mutabilityChanged) = originalSymbol.enhanceMutability(effectiveQualifiers, position)
+
+    var globalArgIndex = index + 1
+    var wereChanges = mutabilityChanged
+    val enhancedArguments = arguments.mapIndexed { localArgIndex, arg ->
+        if (arg is JavaWildcardType) {
+            globalArgIndex++
+            ConeStarProjection
+            // TODO: (?) TypeUtils.makeStarProjection(enhancedClassifier.typeConstructor.parameters[localArgIndex])
+        } else {
+            val argEnhancedTypeRef = arg.enhancePossiblyFlexible(session, annotations, qualifiers, globalArgIndex)
+            wereChanges = wereChanges || argEnhancedTypeRef !== arg
+            globalArgIndex += arg.subtreeSize()
+            argEnhancedTypeRef.type.type.toTypeProjection(Variance.INVARIANT)
+        }
+    }
+
+    val (enhancedNullability, _, nullabilityChanged) = getEnhancedNullability(effectiveQualifiers, position)
+    wereChanges = wereChanges || nullabilityChanged
+
+    if (!wereChanges) return toConeKotlinTypeWithNullability(
+        session, isNullable = position == TypeComponentPosition.FLEXIBLE_UPPER
+    )
+
+    val enhancedType = enhancedSymbol.constructType(enhancedArguments.toTypedArray(), enhancedNullability)
+
+    // TODO: why all of these is needed
+//    val enhancement = if (effectiveQualifiers.isNotNullTypeParameter) NotNullTypeParameter(enhancedType) else enhancedType
+//    val nullabilityForWarning = nullabilityChanged && effectiveQualifiers.isNullabilityQualifierForWarning
+//    val result = if (nullabilityForWarning) wrapEnhancement(enhancement) else enhancement
+
+    return enhancedType
+}
+
+private fun getEnhancedNullability(
+    qualifiers: JavaTypeQualifiers,
+    position: TypeComponentPosition
+): EnhanceDetailsResult<Boolean> {
+    if (!position.shouldEnhance()) return false.noChange()
+
+    return when (qualifiers.nullability) {
+        NullabilityQualifier.NULLABLE -> true.enhancedNullability()
+        NullabilityQualifier.NOT_NULL -> false.enhancedNullability()
+        else -> false.noChange()
+    }
+}
+
+private data class EnhanceDetailsResult<out T>(
+    val result: T,
+    val mutabilityChanged: Boolean = false,
+    val nullabilityChanged: Boolean = false
+)
+
+private fun <T> T.noChange() = EnhanceDetailsResult(this)
+private fun <T> T.enhancedNullability() = EnhanceDetailsResult(this, nullabilityChanged = true)
+private fun <T> T.enhancedMutability() = EnhanceDetailsResult(this, mutabilityChanged = true)
+
+private fun ConeClassifierSymbol.enhanceMutability(
+    qualifiers: JavaTypeQualifiers,
+    position: TypeComponentPosition
+): EnhanceDetailsResult<ConeClassifierSymbol> {
+    if (!position.shouldEnhance()) return this.noChange()
+    if (this !is FirClassSymbol) return this.noChange() // mutability is not applicable for type parameters
+    val fqNameUnsafe = classId.asSingleFqName().toUnsafe()
+
+    when (qualifiers.mutability) {
+        MutabilityQualifier.READ_ONLY -> {
+            val readOnlyFqName = JavaToKotlinClassMap.mutableToReadOnly(fqNameUnsafe)
+            if (position == TypeComponentPosition.FLEXIBLE_LOWER && readOnlyFqName != null) {
+                return FirClassSymbol(ClassId(classId.packageFqName, readOnlyFqName, false)).apply {
+                    bind(fir)
+                }.enhancedMutability()
+            }
+        }
+        MutabilityQualifier.MUTABLE -> {
+            val mutableFqName = JavaToKotlinClassMap.readOnlyToMutable(fqNameUnsafe)
+            if (position == TypeComponentPosition.FLEXIBLE_UPPER && mutableFqName != null) {
+                return FirClassSymbol(ClassId(classId.packageFqName, mutableFqName, false)).apply {
+                    bind(fir)
+                }.enhancedMutability()
+            }
+        }
+    }
+
+    return this.noChange()
+}
+
+
+internal data class TypeAndDefaultQualifiers(
+    val type: FirTypeRef,
+    val defaultQualifiers: JavaTypeQualifiers?
+)
+
+internal fun FirTypeRef.typeArguments(): List<FirTypeProjection> =
+    (this as? FirUserTypeRef)?.qualifier?.lastOrNull()?.typeArguments.orEmpty()
+
+internal fun JavaType.typeArguments(): List<JavaType> = (this as? JavaClassifierType)?.typeArguments.orEmpty()
+
+fun FirValueParameter.getDefaultValueFromAnnotation(): AnnotationDefaultValue? {
+    annotations.find { it.resolvedFqName == JvmAnnotationNames.DEFAULT_VALUE_FQ_NAME }
+        ?.arguments?.firstOrNull()
+        ?.safeAs<FirConstExpression<*>>()?.value?.safeAs<String>()
+        ?.let { return StringDefaultValue(it) }
+
+    if (annotations.any { it.resolvedFqName == JvmAnnotationNames.DEFAULT_NULL_FQ_NAME }) {
+        return NullDefaultValue
+    }
+
+    return null
+}
+

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/nullabilityUtils.kt

@@ -0,0 +1,80 @@
+/*
+ * 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.fir.java.enhancement
+
+import org.jetbrains.kotlin.fir.expressions.FirAnnotationCall
+import org.jetbrains.kotlin.fir.expressions.resolvedFqName
+import org.jetbrains.kotlin.fir.expressions.toResolvedCallableSymbol
+import org.jetbrains.kotlin.load.java.*
+import org.jetbrains.kotlin.load.java.typeEnhancement.NullabilityQualifier
+import org.jetbrains.kotlin.load.java.typeEnhancement.NullabilityQualifierWithMigrationStatus
+import org.jetbrains.kotlin.utils.Jsr305State
+import org.jetbrains.kotlin.utils.addToStdlib.firstNotNullResult
+
+fun List<FirAnnotationCall>.extractNullability(
+    annotationTypeQualifierResolver: FirAnnotationTypeQualifierResolver,
+    jsr305State: Jsr305State
+): NullabilityQualifierWithMigrationStatus? =
+    this.firstNotNullResult { annotationCall ->
+        annotationCall.extractNullability(annotationTypeQualifierResolver, jsr305State)
+    }
+
+
+fun FirAnnotationCall.extractNullability(
+    annotationTypeQualifierResolver: FirAnnotationTypeQualifierResolver,
+    jsr305State: Jsr305State
+): NullabilityQualifierWithMigrationStatus? {
+    this.extractNullabilityFromKnownAnnotations(jsr305State)?.let { return it }
+
+    val typeQualifierAnnotation =
+        annotationTypeQualifierResolver.resolveTypeQualifierAnnotation(this)
+            ?: return null
+
+    val jsr305ReportLevel = annotationTypeQualifierResolver.resolveJsr305ReportLevel(this)
+    if (jsr305ReportLevel.isIgnore) return null
+
+    return typeQualifierAnnotation.extractNullabilityFromKnownAnnotations(jsr305State)?.copy(isForWarningOnly = jsr305ReportLevel.isWarning)
+}
+
+private fun FirAnnotationCall.extractNullabilityFromKnownAnnotations(jsr305State: Jsr305State): NullabilityQualifierWithMigrationStatus? {
+    val annotationFqName = resolvedFqName ?: return null
+
+    return when {
+        annotationFqName in NULLABLE_ANNOTATIONS -> NullabilityQualifierWithMigrationStatus(NullabilityQualifier.NULLABLE)
+        annotationFqName in NOT_NULL_ANNOTATIONS -> NullabilityQualifierWithMigrationStatus(NullabilityQualifier.NOT_NULL)
+        annotationFqName == JAVAX_NONNULL_ANNOTATION -> extractNullabilityTypeFromArgument()
+
+        annotationFqName == COMPATQUAL_NULLABLE_ANNOTATION && jsr305State.enableCompatqualCheckerFrameworkAnnotations ->
+            NullabilityQualifierWithMigrationStatus(NullabilityQualifier.NULLABLE)
+
+        annotationFqName == COMPATQUAL_NONNULL_ANNOTATION && jsr305State.enableCompatqualCheckerFrameworkAnnotations ->
+            NullabilityQualifierWithMigrationStatus(NullabilityQualifier.NOT_NULL)
+
+        annotationFqName == ANDROIDX_RECENTLY_NON_NULL_ANNOTATION -> NullabilityQualifierWithMigrationStatus(
+            NullabilityQualifier.NOT_NULL,
+            isForWarningOnly = true
+        )
+
+        annotationFqName == ANDROIDX_RECENTLY_NULLABLE_ANNOTATION -> NullabilityQualifierWithMigrationStatus(
+            NullabilityQualifier.NULLABLE,
+            isForWarningOnly = true
+        )
+        else -> null
+    }
+}
+
+private fun FirAnnotationCall.extractNullabilityTypeFromArgument(): NullabilityQualifierWithMigrationStatus? {
+    val enumValue = this.arguments.firstOrNull()?.toResolvedCallableSymbol()?.callableId?.callableName
+    // if no argument is specified, use default value: NOT_NULL
+        ?: return NullabilityQualifierWithMigrationStatus(NullabilityQualifier.NOT_NULL)
+
+    return when (enumValue.asString()) {
+        "ALWAYS" -> NullabilityQualifierWithMigrationStatus(NullabilityQualifier.NOT_NULL)
+        "MAYBE", "NEVER" -> NullabilityQualifierWithMigrationStatus(NullabilityQualifier.NULLABLE)
+        "UNKNOWN" -> NullabilityQualifierWithMigrationStatus(NullabilityQualifier.FORCE_FLEXIBILITY)
+        else -> null
+    }
+}

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/scopes/JavaClassEnhancementScope.kt

@@ -0,0 +1,259 @@
+/*
+ * 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.fir.java.scopes
+
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.fir.declarations.impl.FirMemberFunctionImpl
+import org.jetbrains.kotlin.fir.declarations.impl.FirValueParameterImpl
+import org.jetbrains.kotlin.fir.expressions.FirAnnotationContainer
+import org.jetbrains.kotlin.fir.java.declarations.FirJavaMethod
+import org.jetbrains.kotlin.fir.java.declarations.FirJavaValueParameter
+import org.jetbrains.kotlin.fir.java.enhancement.EnhancementSignatureParts
+import org.jetbrains.kotlin.fir.java.enhancement.FirAnnotationTypeQualifierResolver
+import org.jetbrains.kotlin.fir.java.enhancement.FirJavaEnhancementContext
+import org.jetbrains.kotlin.fir.java.enhancement.copyWithNewDefaultTypeQualifiers
+import org.jetbrains.kotlin.fir.java.types.FirJavaTypeRef
+import org.jetbrains.kotlin.fir.scopes.FirScope
+import org.jetbrains.kotlin.fir.scopes.ProcessorAction
+import org.jetbrains.kotlin.fir.symbols.ConeCallableSymbol
+import org.jetbrains.kotlin.fir.symbols.ConeFunctionSymbol
+import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirFunctionSymbol
+import org.jetbrains.kotlin.fir.types.FirResolvedTypeRef
+import org.jetbrains.kotlin.fir.types.FirTypeRef
+import org.jetbrains.kotlin.load.java.AnnotationTypeQualifierResolver
+import org.jetbrains.kotlin.load.java.structure.JavaPrimitiveType
+import org.jetbrains.kotlin.load.java.typeEnhancement.PREDEFINED_FUNCTION_ENHANCEMENT_INFO_BY_SIGNATURE
+import org.jetbrains.kotlin.load.java.typeEnhancement.PredefinedFunctionEnhancementInfo
+import org.jetbrains.kotlin.load.kotlin.SignatureBuildingComponents
+import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.utils.Jsr305State
+
+class JavaClassEnhancementScope(
+    session: FirSession,
+    private val useSiteScope: JavaClassUseSiteScope
+) : FirScope {
+    private val owner: FirRegularClass get() = useSiteScope.symbol.fir
+
+    private val jsr305State: Jsr305State = session.jsr305State ?: Jsr305State.DEFAULT
+
+    private val typeQualifierResolver = FirAnnotationTypeQualifierResolver(jsr305State)
+
+    private val context: FirJavaEnhancementContext =
+        FirJavaEnhancementContext(session) { null }
+
+    private val enhancements = mutableMapOf<ConeCallableSymbol, ConeCallableSymbol>()
+
+    override fun processFunctionsByName(name: Name, processor: (ConeFunctionSymbol) -> ProcessorAction): ProcessorAction {
+        useSiteScope.processFunctionsByName(name) process@{ original ->
+
+            val function = enhancements.getOrPut(original) { enhance(original, name) }
+            processor(function as ConeFunctionSymbol)
+        }
+
+        return super.processFunctionsByName(name, processor)
+    }
+
+    private fun enhance(
+        original: ConeFunctionSymbol,
+        name: Name
+    ): FirFunctionSymbol {
+        val firMethod = (original as FirBasedSymbol<*>).fir as? FirJavaMethod ?: error("Can't fake override for $original")
+
+        val memberContext = context.copyWithNewDefaultTypeQualifiers(
+            typeQualifierResolver, jsr305State, firMethod.annotations
+        )
+        // TODO: When loading method as an override for a property, all annotations are stick to its getter
+//            if (this is FirProperty && getter !is FirDefaultPropertyAccessor)
+//                getter
+//            else
+//                this
+
+        val predefinedEnhancementInfo =
+            SignatureBuildingComponents.signature(owner.symbol.classId, firMethod.computeJvmDescriptor()).let { signature ->
+                PREDEFINED_FUNCTION_ENHANCEMENT_INFO_BY_SIGNATURE[signature]
+            }
+
+        predefinedEnhancementInfo?.let {
+            assert(it.parametersInfo.size == firMethod.valueParameters.size) {
+                "Predefined enhancement info for $this has ${it.parametersInfo.size}, but ${firMethod.valueParameters.size} expected"
+            }
+        }
+
+        val newReceiverTypeRef = if (firMethod.receiverTypeRef != null) enhanceReceiverType(firMethod, memberContext) else null
+        val newReturnTypeRef = enhanceReturnType(firMethod, memberContext, predefinedEnhancementInfo)
+
+        val newValueParameterTypeRefs = mutableListOf<FirResolvedTypeRef>()
+
+        for ((index, valueParameter) in firMethod.valueParameters.withIndex()) {
+            newValueParameterTypeRefs += enhanceValueParameterType(
+                firMethod, memberContext, predefinedEnhancementInfo, valueParameter as FirJavaValueParameter, index
+            )
+        }
+
+
+        val symbol = FirFunctionSymbol(original.callableId)
+        with(firMethod) {
+            FirMemberFunctionImpl(
+                session, null, symbol, name,
+                newReceiverTypeRef, newReturnTypeRef
+            ).apply {
+                status = firMethod.status
+                annotations += firMethod.annotations
+                valueParameters += firMethod.valueParameters.zip(newValueParameterTypeRefs) { valueParameter, newTypeRef ->
+                    with(valueParameter) {
+                        FirValueParameterImpl(
+                            session, psi,
+                            this.name, newTypeRef,
+                            defaultValue, isCrossinline, isNoinline, isVararg
+                        ).apply {
+                            annotations += valueParameter.annotations
+                        }
+                    }
+                }
+            }
+        }
+        return symbol
+    }
+
+    private fun FirJavaMethod.computeJvmDescriptor(): String = buildString {
+        append(name.asString()) // TODO: Java constructors
+
+        append("(")
+        for (parameter in valueParameters) {
+            // TODO: appendErasedType(parameter.returnTypeRef)
+        }
+        append(")")
+
+        if ((returnTypeRef as FirJavaTypeRef).isVoid()) {
+            append("V")
+        } else {
+            // TODO: appendErasedType(returnTypeRef)
+        }
+    }
+
+    private fun FirJavaTypeRef.isVoid(): Boolean {
+        return type is JavaPrimitiveType && type.type == null
+    }
+
+    // ================================================================================================
+
+    private fun enhanceReceiverType(
+        ownerFunction: FirJavaMethod,
+        memberContext: FirJavaEnhancementContext
+    ): FirResolvedTypeRef {
+        val signatureParts = ownerFunction.partsForValueParameter(
+            typeQualifierResolver,
+            // TODO: check me
+            parameterContainer = ownerFunction,
+            methodContext = memberContext
+        ) {
+            it.receiverTypeRef!!
+        }.enhance(jsr305State)
+        return signatureParts.type
+    }
+
+    private val FirTypedDeclaration.valueParameters: List<FirValueParameter> get() = (this as? FirFunction)?.valueParameters.orEmpty()
+
+    private fun enhanceValueParameterType(
+        ownerFunction: FirJavaMethod,
+        memberContext: FirJavaEnhancementContext,
+        predefinedEnhancementInfo: PredefinedFunctionEnhancementInfo?,
+        ownerParameter: FirJavaValueParameter,
+        index: Int
+    ): FirResolvedTypeRef {
+        val signatureParts = ownerFunction.partsForValueParameter(
+            typeQualifierResolver,
+            parameterContainer = ownerParameter,
+            methodContext = memberContext
+        ) {
+            it.valueParameters[index].returnTypeRef
+        }.enhance(jsr305State, predefinedEnhancementInfo?.parametersInfo?.getOrNull(index))
+        return signatureParts.type
+    }
+
+    private fun enhanceReturnType(
+        ownerFunction: FirJavaMethod,
+        memberContext: FirJavaEnhancementContext,
+        predefinedEnhancementInfo: PredefinedFunctionEnhancementInfo?
+    ): FirResolvedTypeRef {
+        val signatureParts = ownerFunction.parts(
+            typeQualifierResolver,
+            typeContainer = ownerFunction, isCovariant = true,
+            containerContext = memberContext,
+            containerApplicabilityType =
+            if (false) // TODO: this.safeAs<FirProperty>()?.isJavaField == true
+                AnnotationTypeQualifierResolver.QualifierApplicabilityType.FIELD
+            else
+                AnnotationTypeQualifierResolver.QualifierApplicabilityType.METHOD_RETURN_TYPE
+        ) { it.returnTypeRef }.enhance(jsr305State, predefinedEnhancementInfo?.returnTypeInfo)
+        return signatureParts.type
+    }
+
+    private fun FirCallableMember.partsForValueParameter(
+        typeQualifierResolver: FirAnnotationTypeQualifierResolver,
+        // TODO: investigate if it's really can be a null (check properties' with extension overrides in Java)
+        parameterContainer: FirAnnotationContainer?,
+        methodContext: FirJavaEnhancementContext,
+        collector: (FirCallableMember) -> FirTypeRef
+    ) = parts(
+        typeQualifierResolver,
+        parameterContainer, false,
+        parameterContainer?.let {
+            methodContext.copyWithNewDefaultTypeQualifiers(typeQualifierResolver, jsr305State, it.annotations)
+        } ?: methodContext,
+        AnnotationTypeQualifierResolver.QualifierApplicabilityType.VALUE_PARAMETER,
+        collector
+    )
+
+    private val overriddenMemberCache = mutableMapOf<FirCallableMember, List<FirCallableMember>>()
+
+    private fun FirCallableMember.overriddenMembers(): List<FirCallableMember> {
+        return overriddenMemberCache.getOrPut(this) {
+            val result = mutableListOf<FirCallableMember>()
+            if (this is FirNamedFunction) {
+                val superTypesScope = useSiteScope.superTypesScope
+                superTypesScope.processFunctionsByName(this.name) { basicFunctionSymbol ->
+                    val overriddenBy = with(useSiteScope) {
+                        basicFunctionSymbol.getOverridden(setOf(this@overriddenMembers.symbol as ConeFunctionSymbol))
+                    }
+                    val overriddenByFir = (overriddenBy as? FirFunctionSymbol)?.fir
+                    if (overriddenByFir === this@overriddenMembers) {
+                        result += (basicFunctionSymbol as FirFunctionSymbol).fir
+                    }
+                    ProcessorAction.NEXT
+                }
+            }
+            result
+        }
+    }
+
+    private fun FirCallableMember.parts(
+        typeQualifierResolver: FirAnnotationTypeQualifierResolver,
+        typeContainer: FirAnnotationContainer?,
+        isCovariant: Boolean,
+        containerContext: FirJavaEnhancementContext,
+        containerApplicabilityType: AnnotationTypeQualifierResolver.QualifierApplicabilityType,
+        collector: (FirCallableMember) -> FirTypeRef
+    ): EnhancementSignatureParts {
+        return EnhancementSignatureParts(
+            typeQualifierResolver,
+            typeContainer,
+            collector(this) as FirJavaTypeRef,
+            this.overriddenMembers().map {
+                collector(it)
+            },
+            isCovariant,
+            // recompute default type qualifiers using type annotations
+            containerContext.copyWithNewDefaultTypeQualifiers(
+                typeQualifierResolver, jsr305State, collector(this).annotations
+            ),
+            containerApplicabilityType
+        )
+    }
+
+}

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/scopes/JavaClassUseSiteScope.kt

@@ -0,0 +1,100 @@
+/*
+ * 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.fir.java.scopes
+
+import org.jetbrains.kotlin.descriptors.Modality
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.declarations.FirNamedFunction
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.java.toNotNullConeKotlinType
+import org.jetbrains.kotlin.fir.scopes.FirScope
+import org.jetbrains.kotlin.fir.scopes.ProcessorAction
+import org.jetbrains.kotlin.fir.scopes.impl.FirAbstractProviderBasedScope
+import org.jetbrains.kotlin.fir.scopes.impl.FirClassDeclaredMemberScope
+import org.jetbrains.kotlin.fir.symbols.ConeCallableSymbol
+import org.jetbrains.kotlin.fir.symbols.ConeFunctionSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirFunctionSymbol
+import org.jetbrains.kotlin.fir.types.ConeKotlinType
+import org.jetbrains.kotlin.fir.types.FirTypeRef
+import org.jetbrains.kotlin.name.Name
+
+class JavaClassUseSiteScope(
+    klass: FirRegularClass,
+    session: FirSession,
+    internal val superTypesScope: FirScope,
+    private val declaredMemberScope: FirClassDeclaredMemberScope
+) : FirAbstractProviderBasedScope(session, lookupInFir = true) {
+    internal val symbol = klass.symbol
+
+    //base symbol as key, overridden as value
+    private val overriddenByBase = mutableMapOf<ConeFunctionSymbol, ConeFunctionSymbol?>()
+
+    @Suppress("UNUSED_PARAMETER")
+    private fun isSubtypeOf(subType: ConeKotlinType, superType: ConeKotlinType): Boolean {
+        // TODO: introduce normal sub-typing
+        return true
+    }
+
+    private fun isSubtypeOf(subType: FirTypeRef, superType: FirTypeRef) =
+        isSubtypeOf(subType.toNotNullConeKotlinType(), superType.toNotNullConeKotlinType())
+
+    @Suppress("UNUSED_PARAMETER")
+    private fun isEqualTypes(a: ConeKotlinType, b: ConeKotlinType): Boolean {
+        // TODO: introduce normal type comparison
+        return true
+    }
+
+    private fun isEqualTypes(a: FirTypeRef, b: FirTypeRef) =
+        isEqualTypes(a.toNotNullConeKotlinType(), b.toNotNullConeKotlinType())
+
+    private fun isOverriddenFunCheck(member: FirNamedFunction, self: FirNamedFunction): Boolean {
+        return member.valueParameters.size == self.valueParameters.size &&
+                member.valueParameters.zip(self.valueParameters).all { (memberParam, selfParam) ->
+                    isEqualTypes(memberParam.returnTypeRef, selfParam.returnTypeRef)
+                }
+    }
+
+    internal fun ConeFunctionSymbol.getOverridden(candidates: Set<ConeFunctionSymbol>): ConeCallableSymbol? {
+        if (overriddenByBase.containsKey(this)) return overriddenByBase[this]
+
+        fun sameReceivers(memberTypeRef: FirTypeRef?, selfTypeRef: FirTypeRef?): Boolean {
+            return when {
+                memberTypeRef != null && selfTypeRef != null -> isEqualTypes(memberTypeRef, selfTypeRef)
+                else -> memberTypeRef == null && selfTypeRef == null
+            }
+        }
+
+        val self = (this as FirFunctionSymbol).fir as FirNamedFunction
+        val overriding = candidates.firstOrNull {
+            val member = (it as FirFunctionSymbol).fir as FirNamedFunction
+            self.modality != Modality.FINAL
+                    && sameReceivers(member.receiverTypeRef, self.receiverTypeRef)
+                    && isSubtypeOf(member.returnTypeRef, self.returnTypeRef)
+                    && isOverriddenFunCheck(member, self)
+        } // TODO: two or more overrides for one fun?
+        overriddenByBase[this] = overriding
+        return overriding
+    }
+
+    override fun processFunctionsByName(name: Name, processor: (ConeFunctionSymbol) -> ProcessorAction): ProcessorAction {
+        val overrideCandidates = mutableSetOf<ConeFunctionSymbol>()
+        if (!declaredMemberScope.processFunctionsByName(name) {
+                overrideCandidates += it
+                processor(it)
+            }
+        ) return ProcessorAction.STOP
+
+        return superTypesScope.processFunctionsByName(name) {
+
+            val overriddenBy = it.getOverridden(overrideCandidates)
+            if (overriddenBy == null) {
+                processor(it)
+            } else {
+                ProcessorAction.NEXT
+            }
+        }
+    }
+}

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/scopes/JavaFirScopeProvider.kt

@@ -0,0 +1,20 @@
+/*
+ * 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.fir.java.scopes
+
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.java.declarations.FirJavaClass
+import org.jetbrains.kotlin.fir.resolve.FirScopeProvider
+import org.jetbrains.kotlin.fir.scopes.FirScope
+
+class JavaFirScopeProvider : FirScopeProvider {
+    override fun getDeclaredMemberScope(klass: FirRegularClass, session: FirSession): FirScope {
+        if (klass !is FirJavaClass) return FirScopeProvider.emptyScope
+
+        return JavaClassEnhancementScope(session, klass.useSiteScope)
+    }
+}

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/FirModuleBasedSession.kt

@@ -6,9 +6,7 @@
 package org.jetbrains.kotlin.fir
 
 import org.jetbrains.kotlin.analyzer.ModuleInfo
-import org.jetbrains.kotlin.fir.resolve.FirProvider
-import org.jetbrains.kotlin.fir.resolve.FirQualifierResolver
-import org.jetbrains.kotlin.fir.resolve.FirTypeResolver
+import org.jetbrains.kotlin.fir.resolve.*
 import org.jetbrains.kotlin.fir.resolve.impl.*
 
 abstract class FirModuleBasedSession(override val moduleInfo: ModuleInfo) : FirSessionBase() {
@@ -19,3 +17,4 @@ abstract class FirModuleBasedSession(override val moduleInfo: ModuleInfo) : FirS
         registerComponent(FirTypeResolver::class, FirTypeResolverImpl(this))
     }
 }
+

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/AbstractFirSymbolProvider.kt

@@ -8,6 +8,8 @@ package org.jetbrains.kotlin.fir.resolve
 import org.jetbrains.kotlin.fir.symbols.CallableId
 import org.jetbrains.kotlin.fir.symbols.ConeCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.ConeClassLikeSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
+import org.jetbrains.kotlin.fir.visitors.FirTransformer
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
 
@@ -38,4 +40,16 @@ abstract class AbstractFirSymbolProvider : FirSymbolProvider {
             calculated.first
         }
     }
+
+    fun <D> transformTopLevelClasses(transformer: FirTransformer<D>, data: D) {
+        val symbols = classCache.values.filterNotNullTo(mutableListOf())
+        // TODO: do something with new symbols which can be found during transformation of another symbols
+        for (symbol in symbols) {
+            if (symbol !is FirClassSymbol) continue
+            if (symbol.classId.relativeClassName.parent().isRoot) {
+                // Launch for top-level classes only
+                symbol.fir.transform(transformer, data)
+            }
+        }
+    }
 }

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/FirScopeProvider.kt

@@ -0,0 +1,18 @@
+/*
+ * 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.fir.resolve
+
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.scopes.FirScope
+
+interface FirScopeProvider {
+    fun getDeclaredMemberScope(klass: FirRegularClass, session: FirSession): FirScope
+
+    companion object {
+        val emptyScope = object : FirScope {}
+    }
+}

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/ResolveUtils.kt

@@ -45,7 +45,7 @@ fun ConeClassifierLookupTag.toSymbol(useSiteSession: FirSession): ConeClassifier
     }
 
 
-fun ConeClassifierSymbol.constructType(typeArguments: Array<ConeKotlinTypeProjection>, isNullable: Boolean): ConeKotlinType {
+fun ConeClassifierSymbol.constructType(typeArguments: Array<ConeKotlinTypeProjection>, isNullable: Boolean): ConeLookupTagBasedType {
     return when (this) {
         is ConeTypeParameterSymbol -> {
             ConeTypeParameterTypeImpl(this, isNullable)

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/SupertypeUtils.kt

@@ -0,0 +1,86 @@
+/*
+ * 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.fir.resolve
+
+import org.jetbrains.kotlin.descriptors.ClassKind
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.declarations.expandedConeType
+import org.jetbrains.kotlin.fir.declarations.superConeTypes
+import org.jetbrains.kotlin.fir.symbols.ConeClassifierSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirTypeAliasSymbol
+import org.jetbrains.kotlin.fir.types.ConeAbbreviatedType
+import org.jetbrains.kotlin.fir.types.ConeClassErrorType
+import org.jetbrains.kotlin.fir.types.ConeClassLikeType
+
+fun lookupSuperTypes(
+    klass: FirRegularClass,
+    lookupInterfaces: Boolean,
+    deep: Boolean,
+    useSiteSession: FirSession
+): List<ConeClassLikeType> {
+    return mutableListOf<ConeClassLikeType>().also {
+        if (lookupInterfaces) klass.symbol.collectSuperTypes(it, deep, useSiteSession)
+        else klass.symbol.collectSuperClasses(it, useSiteSession)
+    }
+}
+
+private tailrec fun ConeClassLikeType.computePartialExpansion(useSiteSession: FirSession): ConeClassLikeType? {
+    return when (this) {
+        is ConeAbbreviatedType -> directExpansionType(useSiteSession)?.computePartialExpansion(useSiteSession)
+        else -> this
+    }
+}
+
+private tailrec fun ConeClassifierSymbol.collectSuperClasses(
+    list: MutableList<ConeClassLikeType>,
+    useSiteSession: FirSession
+) {
+    when (this) {
+        is FirClassSymbol -> {
+            val superClassType =
+                fir.superConeTypes
+                    .map { it.computePartialExpansion(useSiteSession) }
+                    .firstOrNull {
+                        it !is ConeClassErrorType &&
+                                (it?.lookupTag?.toSymbol(useSiteSession) as? FirClassSymbol)?.fir?.classKind == ClassKind.CLASS
+                    } ?: return
+            list += superClassType
+            superClassType.lookupTag.toSymbol(useSiteSession)?.collectSuperClasses(list, useSiteSession)
+        }
+        is FirTypeAliasSymbol -> {
+            val expansion = fir.expandedConeType?.computePartialExpansion(useSiteSession) ?: return
+            expansion.lookupTag.toSymbol(useSiteSession)?.collectSuperClasses(list, useSiteSession)
+        }
+        else -> error("?!id:1")
+    }
+}
+
+private fun ConeClassifierSymbol.collectSuperTypes(
+    list: MutableList<ConeClassLikeType>,
+    deep: Boolean,
+    useSiteSession: FirSession
+) {
+    when (this) {
+        is FirClassSymbol -> {
+            val superClassTypes =
+                fir.superConeTypes.mapNotNull { it.computePartialExpansion(useSiteSession) }
+            list += superClassTypes
+            if (deep)
+                superClassTypes.forEach {
+                    if (it !is ConeClassErrorType) {
+                        it.lookupTag.toSymbol(useSiteSession)?.collectSuperTypes(list, deep, useSiteSession)
+                    }
+                }
+        }
+        is FirTypeAliasSymbol -> {
+            val expansion = fir.expandedConeType?.computePartialExpansion(useSiteSession) ?: return
+            expansion.lookupTag.toSymbol(useSiteSession)?.collectSuperTypes(list, deep, useSiteSession)
+        }
+        else -> error("?!id:1")
+    }
+}

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/impl/FirCompositeScopeProvider.kt

@@ -0,0 +1,18 @@
+/*
+ * 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.fir.resolve.impl
+
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.resolve.FirScopeProvider
+import org.jetbrains.kotlin.fir.scopes.FirScope
+import org.jetbrains.kotlin.fir.scopes.impl.FirCompositeScope
+
+class FirCompositeScopeProvider(private val providers: List<FirScopeProvider>) : FirScopeProvider {
+    override fun getDeclaredMemberScope(klass: FirRegularClass, session: FirSession): FirScope {
+        return FirCompositeScope(providers.mapTo(mutableListOf()) { it.getDeclaredMemberScope(klass, session) })
+    }
+}

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/impl/FirRegularScopeProvider.kt

@@ -0,0 +1,22 @@
+/*
+ * 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.fir.resolve.impl
+
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.declarations.impl.FirClassImpl
+import org.jetbrains.kotlin.fir.resolve.FirScopeProvider
+import org.jetbrains.kotlin.fir.scopes.FirScope
+import org.jetbrains.kotlin.fir.scopes.impl.FirClassDeclaredMemberScope
+
+class FirRegularScopeProvider : FirScopeProvider {
+    override fun getDeclaredMemberScope(klass: FirRegularClass, session: FirSession): FirScope {
+        if (klass !is FirClassImpl) return FirScopeProvider.emptyScope
+
+        return FirClassDeclaredMemberScope(klass, session)
+    }
+
+}

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirAbstractTreeTransformerWithSuperTypes.kt

@@ -5,23 +5,9 @@
 
 package org.jetbrains.kotlin.fir.resolve.transformers
 
-import org.jetbrains.kotlin.descriptors.ClassKind
-import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.FirMemberDeclaration
-import org.jetbrains.kotlin.fir.declarations.FirRegularClass
-import org.jetbrains.kotlin.fir.declarations.expandedConeType
-import org.jetbrains.kotlin.fir.declarations.superConeTypes
-import org.jetbrains.kotlin.fir.resolve.directExpansionType
-import org.jetbrains.kotlin.fir.resolve.toSymbol
 import org.jetbrains.kotlin.fir.scopes.impl.FirCompositeScope
 import org.jetbrains.kotlin.fir.scopes.impl.FirMemberTypeParameterScope
-import org.jetbrains.kotlin.fir.symbols.ConeClassifierSymbol
-import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
-import org.jetbrains.kotlin.fir.symbols.impl.FirTypeAliasSymbol
-import org.jetbrains.kotlin.fir.types.ConeAbbreviatedType
-import org.jetbrains.kotlin.fir.types.ConeClassErrorType
-import org.jetbrains.kotlin.fir.types.ConeClassLikeType
-import org.jetbrains.kotlin.utils.addToStdlib.safeAs
 
 abstract class FirAbstractTreeTransformerWithSuperTypes(reversedScopePriority: Boolean) : FirAbstractTreeTransformer() {
     protected val towerScope = FirCompositeScope(mutableListOf(), reversedPriority = reversedScopePriority)
@@ -37,74 +23,6 @@ abstract class FirAbstractTreeTransformerWithSuperTypes(reversedScopePriority: B
         return result
     }
 
-    protected fun lookupSuperTypes(
-        klass: FirRegularClass,
-        lookupInterfaces: Boolean,
-        deep: Boolean,
-        useSiteSession: FirSession
-    ): List<ConeClassLikeType> {
-        return mutableListOf<ConeClassLikeType>().also {
-            if (lookupInterfaces) klass.symbol.collectSuperTypes(it, deep, useSiteSession)
-            else klass.symbol.collectSuperClasses(it, useSiteSession)
-        }
-    }
-
-    private tailrec fun ConeClassLikeType.computePartialExpansion(useSiteSession: FirSession): ConeClassLikeType? {
-        return when (this) {
-            is ConeAbbreviatedType -> directExpansionType(useSiteSession)?.computePartialExpansion(useSiteSession)
-            else -> this
-        }
-    }
-
-    private tailrec fun ConeClassifierSymbol.collectSuperClasses(
-        list: MutableList<ConeClassLikeType>,
-        useSiteSession: FirSession
-    ) {
-        when (this) {
-            is FirClassSymbol -> {
-                val superClassType =
-                    fir.superConeTypes
-                        .map { it.computePartialExpansion(useSiteSession) }
-                        .firstOrNull {
-                            it !is ConeClassErrorType &&
-                                    (it?.lookupTag?.toSymbol(useSiteSession) as? FirClassSymbol)?.fir?.classKind == ClassKind.CLASS
-                        } ?: return
-                list += superClassType
-                superClassType.lookupTag.toSymbol(useSiteSession)?.collectSuperClasses(list, useSiteSession)
-            }
-            is FirTypeAliasSymbol -> {
-                val expansion = fir.expandedConeType?.computePartialExpansion(useSiteSession) ?: return
-                expansion.lookupTag.toSymbol(useSiteSession)?.collectSuperClasses(list, useSiteSession)
-            }
-            else -> error("?!id:1")
-        }
-    }
-
-    private fun ConeClassifierSymbol.collectSuperTypes(
-        list: MutableList<ConeClassLikeType>,
-        deep: Boolean,
-        useSiteSession: FirSession
-    ) {
-        when (this) {
-            is FirClassSymbol -> {
-                val superClassTypes =
-                    fir.superConeTypes.mapNotNull { it.computePartialExpansion(useSiteSession) }
-                list += superClassTypes
-                if (deep)
-                    superClassTypes.forEach {
-                        if (it !is ConeClassErrorType) {
-                            it.lookupTag.toSymbol(useSiteSession)?.collectSuperTypes(list, deep, useSiteSession)
-                        }
-                    }
-            }
-            is FirTypeAliasSymbol -> {
-                val expansion = fir.expandedConeType?.computePartialExpansion(useSiteSession) ?: return
-                expansion.lookupTag.toSymbol(useSiteSession)?.collectSuperTypes(list, deep, useSiteSession)
-            }
-            else -> error("?!id:1")
-        }
-    }
-
     protected fun FirMemberDeclaration.addTypeParametersScope() {
         val scopes = towerScope.scopes
         if (typeParameters.isNotEmpty()) {

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirAccessResolveTransformer.kt

@@ -14,10 +14,13 @@ import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.references.FirErrorNamedReference
 import org.jetbrains.kotlin.fir.references.FirResolvedCallableReferenceImpl
+import org.jetbrains.kotlin.fir.resolve.FirScopeProvider
+import org.jetbrains.kotlin.fir.resolve.lookupSuperTypes
 import org.jetbrains.kotlin.fir.resolve.toSymbol
 import org.jetbrains.kotlin.fir.scopes.ProcessorAction
 import org.jetbrains.kotlin.fir.scopes.ProcessorAction.NEXT
 import org.jetbrains.kotlin.fir.scopes.impl.*
+import org.jetbrains.kotlin.fir.service
 import org.jetbrains.kotlin.fir.symbols.ConeCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.ConeTypeParameterSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
@@ -53,7 +56,7 @@ class FirAccessResolveTransformer : FirAbstractTreeTransformerWithSuperTypes(rev
 
     private fun FirRegularClass.buildUseSiteScope(useSiteSession: FirSession = session): FirClassUseSiteScope {
         val superTypeScope = FirCompositeScope(mutableListOf())
-        val declaredScope = FirClassDeclaredMemberScope(this, useSiteSession)
+        val declaredScope = useSiteSession.service<FirScopeProvider>().getDeclaredMemberScope(this, useSiteSession)
         lookupSuperTypes(this, lookupInterfaces = true, deep = false, useSiteSession = useSiteSession)
             .mapNotNullTo(superTypeScope.scopes) { useSiteSuperType ->
                 if (useSiteSuperType is ConeClassErrorType) return@mapNotNullTo null

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirSupertypeResolverTransformer.kt

@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.render
 import org.jetbrains.kotlin.fir.resolve.FirProvider
 import org.jetbrains.kotlin.fir.resolve.FirSymbolProvider
+import org.jetbrains.kotlin.fir.resolve.lookupSuperTypes
 import org.jetbrains.kotlin.fir.scopes.FirPosition
 import org.jetbrains.kotlin.fir.scopes.addImportingScopes
 import org.jetbrains.kotlin.fir.scopes.impl.*

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirTypeResolveTransformer.kt

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.resolve.FirProvider
 import org.jetbrains.kotlin.fir.resolve.FirSymbolProvider
+import org.jetbrains.kotlin.fir.resolve.lookupSuperTypes
 import org.jetbrains.kotlin.fir.scopes.FirPosition
 import org.jetbrains.kotlin.fir.scopes.addImportingScopes
 import org.jetbrains.kotlin.fir.scopes.impl.*

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirAbstractProviderBasedScope.kt

@@ -11,7 +11,8 @@ import org.jetbrains.kotlin.fir.resolve.impl.FirCompositeSymbolProvider
 import org.jetbrains.kotlin.fir.resolve.impl.FirDependenciesSymbolProviderImpl
 import org.jetbrains.kotlin.fir.scopes.FirScope
 
-abstract class FirAbstractProviderBasedScope(val session: FirSession, lookupInFir: Boolean = true) : FirScope {
+abstract class FirAbstractProviderBasedScope(val session: FirSession, lookupInFir: Boolean = true) :
+    FirScope {
     val provider = when (val symbolProvider = FirSymbolProvider.getInstance(session)) {
         is FirCompositeSymbolProvider -> symbolProvider.takeIf { !lookupInFir }?.providers?.find {
             it is FirDependenciesSymbolProviderImpl

compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirRenderer.kt

@@ -56,6 +56,10 @@ class FirRenderer(builder: StringBuilder) : FirVisitorVoid() {
         printer.popIndent()
     }
 
+    fun newLine() {
+        println()
+    }
+
     override fun visitElement(element: FirElement) {
         element.acceptChildren(this)
     }
@@ -214,22 +218,32 @@ class FirRenderer(builder: StringBuilder) : FirVisitorVoid() {
     }
 
     private fun FirDeclarationContainer.renderDeclarations() {
+        renderInBraces {
+            for (declaration in declarations) {
+                declaration.accept(this@FirRenderer)
+                println()
+            }
+        }
+    }
+
+    fun renderInBraces(f: () -> Unit) {
         println(" {")
         pushIndent()
-        for (declaration in declarations) {
-            declaration.accept(this@FirRenderer)
-            println()
-        }
+        f()
         popIndent()
         println("}")
     }
 
-    override fun visitRegularClass(regularClass: FirRegularClass) {
-        visitMemberDeclaration(regularClass)
+    fun renderSupertypes(regularClass: FirRegularClass) {
         if (regularClass.superTypeRefs.isNotEmpty()) {
             print(" : ")
             regularClass.superTypeRefs.renderSeparated()
         }
+    }
+
+    override fun visitRegularClass(regularClass: FirRegularClass) {
+        visitMemberDeclaration(regularClass)
+        renderSupertypes(regularClass)
         regularClass.renderDeclarations()
     }
 
@@ -345,14 +359,12 @@ class FirRenderer(builder: StringBuilder) : FirVisitorVoid() {
     }
 
     override fun visitBlock(block: FirBlock) {
-        println(" {")
-        pushIndent()
-        for (statement in block.statements) {
-            statement.accept(this)
-            println()
+        renderInBraces {
+            for (statement in block.statements) {
+                statement.accept(this)
+                println()
+            }
         }
-        popIndent()
-        println("}")
     }
 
     override fun visitTypeAlias(typeAlias: FirTypeAlias) {
@@ -657,8 +669,10 @@ class FirRenderer(builder: StringBuilder) : FirVisitorVoid() {
                 buildString {
                     append("ft<")
                     append(lowerBound.asString())
+                    append(lowerBound.nullability.suffix)
                     append(", ")
                     append(upperBound.asString())
+                    append(upperBound.nullability.suffix)
                     append(">")
                 }
             }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSession.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.fir
 
 import org.jetbrains.kotlin.analyzer.ModuleInfo
+import org.jetbrains.kotlin.utils.Jsr305State
 import kotlin.reflect.KClass
 
 interface FirSession {
@@ -13,6 +14,8 @@ interface FirSession {
 
     val sessionProvider: FirSessionProvider? get() = null
 
+    val jsr305State: Jsr305State? get() = null
+
     val components: Map<KClass<*>, Any>
 
     fun <T : Any> getService(kclass: KClass<T>): T =

compiler/fir/tree/src/org/jetbrains/kotlin/fir/Utils.kt

@@ -29,6 +29,30 @@ fun <T : FirElement, D> MutableList<T>.transformInplace(transformer: FirTransfor
     }
 }
 
+fun <T : FirElement, D> MutableList<T>.transformInplaceWithBeforeOperation(
+    transformer: FirTransformer<D>, data: D, operation: (T, Int) -> Unit
+) {
+    val iterator = this.listIterator()
+    var index = 0
+    while (iterator.hasNext()) {
+        val next = iterator.next()
+        operation(next, index++)
+        val result = next.transform<T, D>(transformer, data)
+        if (result.isSingle) {
+            iterator.set(result.single)
+        } else {
+            val resultIterator = result.list.listIterator()
+            if (!resultIterator.hasNext()) {
+                iterator.remove()
+            } else {
+                iterator.set(resultIterator.next())
+            }
+            while (resultIterator.hasNext()) {
+                iterator.add(resultIterator.next())
+            }
+        }
+    }
+}
 
 fun <T : FirElement, D> T.transformSingle(transformer: FirTransformer<D>, data: D): T {
     return this.transform<T, D>(transformer, data).single

compiler/fir/tree/src/org/jetbrains/kotlin/fir/expressions/FirAnnotationCall.kt

@@ -7,8 +7,11 @@ package org.jetbrains.kotlin.fir.expressions
 
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget
 import org.jetbrains.kotlin.fir.BaseTransformedType
+import org.jetbrains.kotlin.fir.types.ConeClassLikeType
+import org.jetbrains.kotlin.fir.types.FirResolvedTypeRef
 import org.jetbrains.kotlin.fir.types.FirTypeRef
 import org.jetbrains.kotlin.fir.visitors.FirVisitor
+import org.jetbrains.kotlin.name.FqName
 
 @BaseTransformedType
 interface FirAnnotationCall : FirCall {
@@ -24,4 +27,7 @@ interface FirAnnotationCall : FirCall {
         annotationTypeRef.accept(visitor, data)
         super.acceptChildren(visitor, data)
     }
-}
+}
+
+val FirAnnotationCall.resolvedFqName: FqName?
+    get() = ((annotationTypeRef as? FirResolvedTypeRef)?.type as? ConeClassLikeType)?.lookupTag?.classId?.asSingleFqName()

compiler/fir/tree/src/org/jetbrains/kotlin/fir/expressions/FirExpression.kt

@@ -5,9 +5,19 @@
 
 package org.jetbrains.kotlin.fir.expressions
 
+import org.jetbrains.kotlin.fir.FirResolvedCallableReference
+import org.jetbrains.kotlin.fir.symbols.ConeCallableSymbol
 import org.jetbrains.kotlin.fir.visitors.FirVisitor
 
 interface FirExpression : FirStatement {
     override fun <R, D> accept(visitor: FirVisitor<R, D>, data: D): R =
         visitor.visitExpression(this, data)
+}
+
+fun FirExpression.toResolvedCallableReference(): FirResolvedCallableReference? {
+    return (this as? FirQualifiedAccess)?.calleeReference as? FirResolvedCallableReference
+}
+
+fun FirExpression.toResolvedCallableSymbol(): ConeCallableSymbol? {
+    return toResolvedCallableReference()?.callableSymbol
 }

core/descriptors.jvm/src/org/jetbrains/kotlin/builtins/jvm/JavaToKotlinClassMap.kt

@@ -213,14 +213,22 @@ object JavaToKotlinClassMap : PlatformToKotlinClassMap {
             emptySet<ClassDescriptor>()
     }
 
-    fun isMutable(mutable: ClassDescriptor): Boolean = mutableToReadOnly.containsKey(DescriptorUtils.getFqName(mutable))
+    fun mutableToReadOnly(fqNameUnsafe: FqNameUnsafe?): FqName? = mutableToReadOnly[fqNameUnsafe]
+
+    fun readOnlyToMutable(fqNameUnsafe: FqNameUnsafe?): FqName? = readOnlyToMutable[fqNameUnsafe]
+
+    fun isMutable(fqNameUnsafe: FqNameUnsafe?): Boolean = mutableToReadOnly.containsKey(fqNameUnsafe)
+
+    fun isMutable(mutable: ClassDescriptor): Boolean = isMutable(DescriptorUtils.getFqName(mutable))
 
     fun isMutable(type: KotlinType): Boolean {
         val classDescriptor = TypeUtils.getClassDescriptor(type)
         return classDescriptor != null && isMutable(classDescriptor)
     }
 
-    fun isReadOnly(readOnly: ClassDescriptor): Boolean = readOnlyToMutable.containsKey(DescriptorUtils.getFqName(readOnly))
+    fun isReadOnly(fqNameUnsafe: FqNameUnsafe?): Boolean = readOnlyToMutable.containsKey(fqNameUnsafe)
+
+    fun isReadOnly(readOnly: ClassDescriptor): Boolean = isReadOnly(DescriptorUtils.getFqName(readOnly))
 
     fun isReadOnly(type: KotlinType): Boolean {
         val classDescriptor = TypeUtils.getClassDescriptor(type)

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/AnnotationTypeQualifierResolver.kt

@@ -34,13 +34,13 @@ import org.jetbrains.kotlin.utils.Jsr305State
 import org.jetbrains.kotlin.utils.ReportLevel
 import org.jetbrains.kotlin.utils.addToStdlib.firstNotNullResult
 
-private val TYPE_QUALIFIER_NICKNAME_FQNAME = FqName("javax.annotation.meta.TypeQualifierNickname")
-private val TYPE_QUALIFIER_FQNAME = FqName("javax.annotation.meta.TypeQualifier")
-private val TYPE_QUALIFIER_DEFAULT_FQNAME = FqName("javax.annotation.meta.TypeQualifierDefault")
+val TYPE_QUALIFIER_NICKNAME_FQNAME = FqName("javax.annotation.meta.TypeQualifierNickname")
+val TYPE_QUALIFIER_FQNAME = FqName("javax.annotation.meta.TypeQualifier")
+val TYPE_QUALIFIER_DEFAULT_FQNAME = FqName("javax.annotation.meta.TypeQualifierDefault")
 
-private val MIGRATION_ANNOTATION_FQNAME = FqName("kotlin.annotations.jvm.UnderMigration")
+val MIGRATION_ANNOTATION_FQNAME = FqName("kotlin.annotations.jvm.UnderMigration")
 
-private val BUILT_IN_TYPE_QUALIFIER_DEFAULT_ANNOTATIONS = mapOf(
+val BUILT_IN_TYPE_QUALIFIER_DEFAULT_ANNOTATIONS = mapOf(
         FqName("javax.annotation.ParametersAreNullableByDefault") to
                 NullabilityQualifierWithApplicability(
                         NullabilityQualifierWithMigrationStatus(NullabilityQualifier.NULLABLE),

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/lazy/context.kt

@@ -93,9 +93,9 @@ interface JavaResolverSettings {
     }
 }
 
-private typealias QualifierByApplicabilityType = EnumMap<AnnotationTypeQualifierResolver.QualifierApplicabilityType, NullabilityQualifierWithMigrationStatus?>
+typealias QualifierByApplicabilityType = EnumMap<AnnotationTypeQualifierResolver.QualifierApplicabilityType, NullabilityQualifierWithMigrationStatus?>
 
-class JavaTypeQualifiersByElementType(internal val nullabilityQualifiers: QualifierByApplicabilityType) {
+class JavaTypeQualifiersByElementType(val nullabilityQualifiers: QualifierByApplicabilityType) {
     operator fun get(applicabilityType: AnnotationTypeQualifierResolver.QualifierApplicabilityType?): JavaTypeQualifiers? {
         val nullabilityQualifierWithMigrationStatus = nullabilityQualifiers[applicabilityType] ?: return null
 

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/typeEnhancement/signatureEnhancement.kt

@@ -462,7 +462,7 @@ class SignatureEnhancement(
     }
 }
 
-private fun createJavaTypeQualifiers(
+fun createJavaTypeQualifiers(
     nullability: NullabilityQualifier?,
     mutability: MutabilityQualifier?,
     forWarning: Boolean,
@@ -474,7 +474,7 @@ private fun createJavaTypeQualifiers(
     return JavaTypeQualifiers(nullability, mutability, true, forWarning)
 }
 
-private fun <T : Any> Set<T>.select(low: T, high: T, own: T?, isCovariant: Boolean): T? {
+fun <T : Any> Set<T>.select(low: T, high: T, own: T?, isCovariant: Boolean): T? {
     if (isCovariant) {
         val supertypeQualifier = if (low in this) low else if (high in this) high else null
         return if (supertypeQualifier == low && own == high) null else own ?: supertypeQualifier
@@ -488,7 +488,7 @@ private fun <T : Any> Set<T>.select(low: T, high: T, own: T?, isCovariant: Boole
     return effectiveSet.singleOrNull()
 }
 
-private fun Set<NullabilityQualifier>.select(own: NullabilityQualifier?, isCovariant: Boolean) =
+fun Set<NullabilityQualifier>.select(own: NullabilityQualifier?, isCovariant: Boolean) =
     if (own == NullabilityQualifier.FORCE_FLEXIBILITY)
         NullabilityQualifier.FORCE_FLEXIBILITY
     else

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/typeEnhancement/typeEnhancement.kt

@@ -45,7 +45,7 @@ fun KotlinType.enhance(qualifiers: (Int) -> JavaTypeQualifiers) = unwrap().enhan
 fun KotlinType.hasEnhancedNullability()
         = annotations.findAnnotation(JvmAnnotationNames.ENHANCED_NULLABILITY_ANNOTATION) != null
 
-private enum class TypeComponentPosition {
+enum class TypeComponentPosition {
     FLEXIBLE_LOWER,
     FLEXIBLE_UPPER,
     INFLEXIBLE
@@ -147,7 +147,7 @@ private fun List<Annotations>.compositeAnnotationsOrSingle() = when (size) {
     else -> CompositeAnnotations(this.toList())
 }
 
-private fun TypeComponentPosition.shouldEnhance() = this != TypeComponentPosition.INFLEXIBLE
+fun TypeComponentPosition.shouldEnhance() = this != TypeComponentPosition.INFLEXIBLE
 
 private data class EnhancementResult<out T>(val result: T, val enhancementAnnotations: Annotations?)
 private fun <T> T.noChange() = EnhancementResult(this, null)

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/typeEnhancement/typeQualifiers.kt

@@ -27,11 +27,11 @@ enum class MutabilityQualifier {
     MUTABLE
 }
 
-class JavaTypeQualifiers internal constructor(
-        val nullability: NullabilityQualifier?,
-        val mutability: MutabilityQualifier?,
-        internal val isNotNullTypeParameter: Boolean,
-        internal val isNullabilityQualifierForWarning: Boolean = false
+class JavaTypeQualifiers(
+    val nullability: NullabilityQualifier?,
+    val mutability: MutabilityQualifier?,
+    val isNotNullTypeParameter: Boolean,
+    val isNullabilityQualifierForWarning: Boolean = false
 ) {
     companion object {
         val NONE = JavaTypeQualifiers(null, null, false)

idea/testData/fir/multiModule/basicWithAnnotatedJava/extraDump.java.txt

@@ -0,0 +1,4 @@
+public open class Annotated : R|java/lang/Object| {
+    @R|org/jetbrains/annotations/NotNull|() public open operator function foo(@R|org/jetbrains/annotations/Nullable|() param: R|ft<java/lang/String?, java/lang/String?>|?): R|ft<java/lang/String, java/lang/String>|
+
+}

idea/testData/fir/multiModule/basicWithAnnotatedJava/jvm/Annotated.java

@@ -0,0 +1,10 @@
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class Annotated {
+    @NotNull
+    public String foo(@Nullable String param) {
+        if (param != null) return param;
+        else return "";
+    }
+}

idea/testData/fir/multiModule/basicWithAnnotatedJava/jvm/jvm.kt

@@ -0,0 +1,6 @@
+class User : Annotated() {
+    fun test() {
+        val x = foo("123")
+        val y = foo(null)
+    }
+}

idea/testData/fir/multiModule/basicWithAnnotatedJava/jvm/jvm.txt

@@ -0,0 +1,10 @@
+FILE: jvm.kt
+    public final class User : R|Annotated| {
+        public constructor(): super<R|Annotated|>()
+
+        public final function test(): R|kotlin/Unit| {
+            val x: R|error: Not supported: FirImplicitTypeRefImpl| = R|/Annotated.foo|(String(123))
+            val y: R|error: Not supported: FirImplicitTypeRefImpl| = R|/Annotated.foo|(Null(null))
+        }
+
+    }

idea/testData/fir/multiModule/basicWithAnnotatedOverriddenJava/extraDump.java.txt

@@ -0,0 +1,8 @@
+public open class Annotated : R|java/lang/Object| {
+    @R|org/jetbrains/annotations/NotNull|() public open operator function foo(@R|org/jetbrains/annotations/Nullable|() param: R|ft<java/lang/String?, java/lang/String?>|?): R|ft<java/lang/String, java/lang/String>|
+
+}
+public open class AnnotatedDerived : R|Annotated| {
+    public open operator function foo(param: R|ft<java/lang/String?, java/lang/String?>|?): R|ft<java/lang/String, java/lang/String>|
+
+}

idea/testData/fir/multiModule/basicWithAnnotatedOverriddenJava/jvm/Annotated.java

@@ -0,0 +1,10 @@
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class Annotated {
+    @NotNull
+    public String foo(@Nullable String param) {
+        if (param != null) return param;
+        else return "";
+    }
+}

idea/testData/fir/multiModule/basicWithAnnotatedOverriddenJava/jvm/AnnotatedDerived.java

@@ -0,0 +1,5 @@
+public class AnnotatedDerived extends Annotated {
+    public String foo(String param) {
+        return super.foo(param);
+    }
+}

idea/testData/fir/multiModule/basicWithAnnotatedOverriddenJava/jvm/jvm.kt

@@ -0,0 +1,6 @@
+class User : AnnotatedDerived() {
+    fun test() {
+        val x = foo("123")
+        val y = foo(null)
+    }
+}

idea/testData/fir/multiModule/basicWithAnnotatedOverriddenJava/jvm/jvm.txt

@@ -0,0 +1,10 @@
+FILE: jvm.kt
+    public final class User : R|AnnotatedDerived| {
+        public constructor(): super<R|AnnotatedDerived|>()
+
+        public final function test(): R|kotlin/Unit| {
+            val x: R|error: Not supported: FirImplicitTypeRefImpl| = <Ambiguity: foo, [/AnnotatedDerived.foo, /Annotated.foo]>#(String(123))
+            val y: R|error: Not supported: FirImplicitTypeRefImpl| = <Ambiguity: foo, [/AnnotatedDerived.foo, /Annotated.foo]>#(Null(null))
+        }
+
+    }

idea/testData/fir/multiModule/basicWithJava/extraDump.java.txt

@@ -0,0 +1,2 @@
+public open class Some : R|java/lang/Object| {
+}

idea/testData/fir/multiModule/basicWithJavaFakeOverride/extraDump.java.txt

@@ -0,0 +1,4 @@
+<T> public open class A : R|java/lang/Object| {
+    public open operator function foo(t: R|ft<T, T?>|!): R|ft<T, T?>|!
+
+}

idea/testData/fir/multiModule/basicWithJavaFakeOverride/jvm/simpleFakeOverride.txt

@@ -7,7 +7,7 @@ FILE: simpleFakeOverride.kt
         public constructor(): super<R|A<Some>|>()
 
         public final function test(): R|kotlin/Unit| {
-            R|FakeOverride</A.foo: R|ft<T, T>|!>|(<Unresolved name: Some>#())
+            R|FakeOverride</A.foo: R|ft<T, T?>|!>|(<Unresolved name: Some>#())
         }
 
     }

idea/testData/fir/multiModule/basicWithPrimitiveJava/extraDump.java.txt

@@ -0,0 +1,6 @@
+public open class Some : R|java/lang/Object| {
+    public open operator function foo(param: R|kotlin/Int|): R|kotlin/Boolean|
+
+    public open operator function bar(arr: R|kotlin/IntArray|): R|kotlin/Array<ft<java/lang/String, java/lang/String?>>|
+
+}

idea/testData/fir/multiModule/basicWithPrimitiveJava/jvm/Some.java

@@ -0,0 +1,14 @@
+public class Some {
+    public boolean foo(int param) {
+        return param > 0;
+    }
+
+    public String[] bar(int[] arr) {
+        String[] result = new String[arr.length];
+        int i = 0;
+        for (int elem: arr) {
+            result[i++] = elem;
+        }
+        return result;
+    }
+}

idea/testData/fir/multiModule/basicWithPrimitiveJava/jvm/jvm.kt

@@ -0,0 +1,7 @@
+class A : Some() {
+    fun test() {
+        val res1 = foo(1)
+        val res2 = foo(-1)
+        val res3 = bar(intArrayOf(0, 2, -2))
+    }
+}

idea/testData/fir/multiModule/basicWithPrimitiveJava/jvm/jvm.txt

@@ -0,0 +1,11 @@
+FILE: jvm.kt
+    public final class A : R|Some| {
+        public constructor(): super<R|Some|>()
+
+        public final function test(): R|kotlin/Unit| {
+            val res1: R|error: Not supported: FirImplicitTypeRefImpl| = R|/Some.foo|(Int(1))
+            val res2: R|error: Not supported: FirImplicitTypeRefImpl| = R|/Some.foo|(<Unresolved name: unaryMinus>#(Int(1)))
+            val res3: R|error: Not supported: FirImplicitTypeRefImpl| = R|/Some.bar|(<Unresolved name: intArrayOf>#(Int(0), Int(2), <Unresolved name: unaryMinus>#(Int(2))))
+        }
+
+    }

idea/testData/fir/multiModule/overrideWithJava/extraDump.java.txt

@@ -0,0 +1,6 @@
+public open class A : R|java/lang/Object| {
+    public open operator function foo(): R|ft<A, A?>|!
+
+    public open operator function bar(): R|ft<A, A?>|!
+
+}

idea/tests/org/jetbrains/kotlin/idea/fir/AbstractFirMultiModuleResolveTest.kt

@@ -12,15 +12,26 @@ import com.intellij.psi.PsiManager
 import com.intellij.psi.search.FileTypeIndex
 import org.jetbrains.kotlin.fir.FirRenderer
 import org.jetbrains.kotlin.fir.builder.RawFirBuilder
+import org.jetbrains.kotlin.fir.declarations.FirDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirFile
 import org.jetbrains.kotlin.fir.dependenciesWithoutSelf
 import org.jetbrains.kotlin.fir.java.FirJavaModuleBasedSession
 import org.jetbrains.kotlin.fir.java.FirLibrarySession
 import org.jetbrains.kotlin.fir.java.FirProjectSessionProvider
+import org.jetbrains.kotlin.fir.java.JavaSymbolProvider
+import org.jetbrains.kotlin.fir.java.declarations.FirJavaClass
+import org.jetbrains.kotlin.fir.java.declarations.FirJavaMethod
+import org.jetbrains.kotlin.fir.java.scopes.JavaClassEnhancementScope
 import org.jetbrains.kotlin.fir.resolve.FirProvider
+import org.jetbrains.kotlin.fir.resolve.FirScopeProvider
+import org.jetbrains.kotlin.fir.resolve.FirSymbolProvider
+import org.jetbrains.kotlin.fir.resolve.impl.FirCompositeSymbolProvider
 import org.jetbrains.kotlin.fir.resolve.impl.FirProviderImpl
 import org.jetbrains.kotlin.fir.resolve.transformers.FirTotalResolveTransformer
+import org.jetbrains.kotlin.fir.scopes.ProcessorAction
+import org.jetbrains.kotlin.fir.scopes.impl.FirCompositeScope
 import org.jetbrains.kotlin.fir.service
+import org.jetbrains.kotlin.fir.symbols.impl.FirFunctionSymbol
 import org.jetbrains.kotlin.idea.KotlinFileType
 import org.jetbrains.kotlin.idea.caches.project.IdeaModuleInfo
 import org.jetbrains.kotlin.idea.caches.project.isLibraryClasses
@@ -64,9 +75,11 @@ abstract class AbstractFirMultiModuleResolveTest : AbstractMultiModuleTest() {
 
     private fun doFirResolveTest(dirPath: String) {
         val firFiles = mutableListOf<FirFile>()
+        val sessions = mutableListOf<FirJavaModuleBasedSession>()
         val provider = FirProjectSessionProvider(project)
         for (module in project.allModules().drop(1)) {
             val session = createSession(module, provider)
+            sessions += session
 
             val builder = RawFirBuilder(session, stubMode = false)
             val psiManager = PsiManager.getInstance(project)
@@ -112,5 +125,54 @@ abstract class AbstractFirMultiModuleResolveTest : AbstractMultiModuleTest() {
             val expectedPath = expectedTxtPath((file.psi as PsiFile).virtualFile)
             KotlinTestUtils.assertEqualsToFile(File(expectedPath), firFileDump)
         }
+        val processedJavaClasses = mutableSetOf<FirJavaClass>()
+        val javaFirDump = StringBuilder().also { builder ->
+            val renderer = FirRenderer(builder)
+            for (session in sessions) {
+                val symbolProvider = session.service<FirSymbolProvider>() as FirCompositeSymbolProvider
+                val javaProvider = symbolProvider.providers.filterIsInstance<JavaSymbolProvider>().first()
+                for (javaClass in javaProvider.getJavaTopLevelClasses().sortedBy { it.name }) {
+                    if (javaClass !is FirJavaClass || javaClass in processedJavaClasses) continue
+                    val enhancementScope = session.service<FirScopeProvider>().getDeclaredMemberScope(javaClass, session).let {
+                        when (it) {
+                            is FirCompositeScope -> it.scopes.filterIsInstance<JavaClassEnhancementScope>().first()
+                            is JavaClassEnhancementScope -> it
+                            else -> null
+                        }
+                    }
+                    if (enhancementScope == null) {
+                        javaClass.accept(renderer, null)
+                    } else {
+                        renderer.visitMemberDeclaration(javaClass)
+                        renderer.renderSupertypes(javaClass)
+                        renderer.renderInBraces {
+                            val renderedDeclarations = mutableListOf<FirDeclaration>()
+                            for (declaration in javaClass.declarations) {
+                                if (declaration in renderedDeclarations) continue
+                                if (declaration !is FirJavaMethod) {
+                                    declaration.accept(renderer, null)
+                                    renderer.newLine()
+                                    renderedDeclarations += declaration
+                                } else {
+                                    enhancementScope.processFunctionsByName(declaration.name) { symbol ->
+                                        val enhanced = (symbol as? FirFunctionSymbol)?.fir
+                                        if (enhanced != null && enhanced !in renderedDeclarations) {
+                                            enhanced.accept(renderer, null)
+                                            renderer.newLine()
+                                            renderedDeclarations += enhanced
+                                        }
+                                        ProcessorAction.NEXT
+                                    }
+                                }
+                            }
+                        }
+                    }
+                    processedJavaClasses += javaClass
+                }
+            }
+        }.toString()
+        if (javaFirDump.isNotEmpty()) {
+            KotlinTestUtils.assertEqualsToFile(File("$dirPath/extraDump.java.txt"), javaFirDump)
+        }
     }
 }

idea/tests/org/jetbrains/kotlin/idea/fir/FirMultiModuleResolveTestGenerated.java

@@ -34,6 +34,16 @@ public class FirMultiModuleResolveTestGenerated extends AbstractFirMultiModuleRe
         runTest("idea/testData/fir/multiModule/basic/");
     }
 
+    @TestMetadata("basicWithAnnotatedJava")
+    public void testBasicWithAnnotatedJava() throws Exception {
+        runTest("idea/testData/fir/multiModule/basicWithAnnotatedJava/");
+    }
+
+    @TestMetadata("basicWithAnnotatedOverriddenJava")
+    public void testBasicWithAnnotatedOverriddenJava() throws Exception {
+        runTest("idea/testData/fir/multiModule/basicWithAnnotatedOverriddenJava/");
+    }
+
     @TestMetadata("basicWithJava")
     public void testBasicWithJava() throws Exception {
         runTest("idea/testData/fir/multiModule/basicWithJava/");
@@ -44,6 +54,11 @@ public class FirMultiModuleResolveTestGenerated extends AbstractFirMultiModuleRe
         runTest("idea/testData/fir/multiModule/basicWithJavaFakeOverride/");
     }
 
+    @TestMetadata("basicWithPrimitiveJava")
+    public void testBasicWithPrimitiveJava() throws Exception {
+        runTest("idea/testData/fir/multiModule/basicWithPrimitiveJava/");
+    }
+
     @TestMetadata("mppFakeOverrides")
     public void testMppFakeOverrides() throws Exception {
         runTest("idea/testData/fir/multiModule/mppFakeOverrides/");