Fix UL classes descriptors leaks

UL classes built upon descriptors and UL support classes are saving a descriptors.
This could lead to descriptors leakage so we have to eliminate any fields with descriptor references.

Fixed #KT-34337

compiler/light-classes/src/org/jetbrains/kotlin/asJava/classes/ultraLightAnnotations.kt

@@ -11,46 +11,21 @@ import com.intellij.psi.impl.PsiImplUtil
 import com.intellij.psi.impl.light.LightIdentifier
 import com.intellij.psi.meta.PsiMetaData
 import com.intellij.psi.util.TypeConversionUtil
-import org.jetbrains.annotations.NotNull
-import org.jetbrains.annotations.Nullable
 import org.jetbrains.kotlin.asJava.elements.KtLightAbstractAnnotation
 import org.jetbrains.kotlin.asJava.elements.KtLightElementBase
 import org.jetbrains.kotlin.asJava.elements.KtLightNullabilityAnnotation
 import org.jetbrains.kotlin.asJava.elements.psiType
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
-import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.KtCallElement
 import org.jetbrains.kotlin.psi.KtElement
 import org.jetbrains.kotlin.resolve.constants.*
-import org.jetbrains.kotlin.types.KotlinType
-import org.jetbrains.kotlin.types.TypeUtils
-import org.jetbrains.kotlin.types.isError
-import org.jetbrains.kotlin.types.typeUtil.TypeNullability
-import org.jetbrains.kotlin.types.typeUtil.isTypeParameter
-import org.jetbrains.kotlin.types.typeUtil.nullability
 
 class KtUltraLightNullabilityAnnotation(
     member: KtUltraLightElementWithNullabilityAnnotation<*, *>,
     parent: PsiElement
 ) : KtLightNullabilityAnnotation<KtUltraLightElementWithNullabilityAnnotation<*, *>>(member, parent) {
-    override fun getQualifiedName(): String? {
-        val kotlinType = member.kotlinTypeForNullabilityAnnotation?.takeUnless(KotlinType::isError) ?: return null
-        val psiType = member.psiTypeForNullabilityAnnotation ?: return null
-        if (psiType is PsiPrimitiveType) return null
-
-        if (kotlinType.isTypeParameter()) {
-            if (!TypeUtils.hasNullableSuperType(kotlinType)) return NotNull::class.java.name
-            if (!kotlinType.isMarkedNullable) return null
-        }
-
-        val nullability = kotlinType.nullability()
-        return when (nullability) {
-            TypeNullability.NOT_NULL -> NotNull::class.java.name
-            TypeNullability.NULLABLE -> Nullable::class.java.name
-            TypeNullability.FLEXIBLE -> null
-        }
-    }
+    override fun getQualifiedName(): String? = member.qualifiedNameForNullabilityAnnotation
 }
 
 fun AnnotationDescriptor.toLightAnnotation(ultraLightSupport: KtUltraLightSupport, parent: PsiElement) =

compiler/light-classes/src/org/jetbrains/kotlin/asJava/classes/ultraLightClass.kt

@@ -160,7 +160,7 @@ open class KtUltraLightClass(classOrObject: KtClassOrObject, internal val suppor
         return forExtendsList == !JvmCodegenUtil.isJvmInterface(supertype)
     }
 
-    override fun buildTypeParameterList(): PsiTypeParameterList = buildTypeParameterList(classOrObject, this, support)
+    override fun buildTypeParameterList(): PsiTypeParameterList = buildTypeParameterListForSourceDeclaration(classOrObject, this, support)
 
     // the following logic should be in the platform (super), overrides can be removed once that happens
     override fun getInterfaces(): Array<PsiClass> = PsiClassImplUtil.getInterfaces(this)

compiler/light-classes/src/org/jetbrains/kotlin/asJava/classes/ultraLightElementWithNullabilityAnnotation.kt

@@ -6,13 +6,39 @@
 package org.jetbrains.kotlin.asJava.classes
 
 import com.intellij.psi.PsiModifierListOwner
+import com.intellij.psi.PsiPrimitiveType
 import com.intellij.psi.PsiType
+import org.jetbrains.annotations.NotNull
+import org.jetbrains.annotations.Nullable
 import org.jetbrains.kotlin.asJava.elements.KtLightDeclaration
 import org.jetbrains.kotlin.psi.KtDeclaration
 import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.TypeUtils
+import org.jetbrains.kotlin.types.isError
+import org.jetbrains.kotlin.types.typeUtil.TypeNullability
+import org.jetbrains.kotlin.types.typeUtil.isTypeParameter
+import org.jetbrains.kotlin.types.typeUtil.nullability
 
 interface KtUltraLightElementWithNullabilityAnnotation<out T : KtDeclaration, out D : PsiModifierListOwner> : KtLightDeclaration<T, D>,
     PsiModifierListOwner {
-    val kotlinTypeForNullabilityAnnotation: KotlinType?
+
+    fun computeQualifiedNameForNullabilityAnnotation(kotlinType: KotlinType?): String? {
+        val notErrorKotlinType = kotlinType?.takeUnless(KotlinType::isError) ?: return null
+        val psiType = psiTypeForNullabilityAnnotation ?: return null
+        if (psiType is PsiPrimitiveType) return null
+
+        if (notErrorKotlinType.isTypeParameter()) {
+            if (!TypeUtils.hasNullableSuperType(notErrorKotlinType)) return NotNull::class.java.name
+            if (!notErrorKotlinType.isMarkedNullable) return null
+        }
+
+        return when (notErrorKotlinType.nullability()) {
+            TypeNullability.NOT_NULL -> NotNull::class.java.name
+            TypeNullability.NULLABLE -> Nullable::class.java.name
+            TypeNullability.FLEXIBLE -> null
+        }
+    }
+
+    val qualifiedNameForNullabilityAnnotation: String?
     val psiTypeForNullabilityAnnotation: PsiType?
 }

compiler/light-classes/src/org/jetbrains/kotlin/asJava/classes/ultraLightField.kt

@@ -82,10 +82,10 @@ internal open class KtUltraLightFieldImpl protected constructor(
 
     override fun getLanguage(): Language = KotlinLanguage.INSTANCE
 
-    private val propertyDescriptor: PropertyDescriptor? by lazyPub { declaration.resolve() as? PropertyDescriptor }
+    private val propertyDescriptor: PropertyDescriptor? get() = declaration.resolve() as? PropertyDescriptor
 
-    private val kotlinType: KotlinType? by lazyPub {
-        when {
+    private val kotlinType: KotlinType?
+        get() = when {
             declaration is KtProperty && declaration.hasDelegate() ->
                 propertyDescriptor?.let {
                     val context = LightClassGenerationSupport.getInstance(project).analyze(declaration)
@@ -100,11 +100,13 @@ internal open class KtUltraLightFieldImpl protected constructor(
                 declaration.getKotlinType()
             }
         }
-    }
 
-    override val kotlinTypeForNullabilityAnnotation: KotlinType?
-        // We don't generate nullability annotations for non-backing fields in backend
-        get() = kotlinType?.takeUnless { declaration is KtEnumEntry || declaration is KtObjectDeclaration }
+    override val qualifiedNameForNullabilityAnnotation: String?
+        get() {
+            // We don't generate nullability annotations for non-backing fields in backend
+            val typeForAnnotation = kotlinType?.takeUnless { declaration is KtEnumEntry || declaration is KtObjectDeclaration }
+            return computeQualifiedNameForNullabilityAnnotation(typeForAnnotation)
+        }
 
     override val psiTypeForNullabilityAnnotation: PsiType?
         get() = type

compiler/light-classes/src/org/jetbrains/kotlin/asJava/classes/ultraLightMethods.kt

@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.asJava.builder.MemberIndex
 import org.jetbrains.kotlin.asJava.elements.KtLightAbstractAnnotation
 import org.jetbrains.kotlin.asJava.elements.KtLightMethodImpl
 import org.jetbrains.kotlin.codegen.FunctionCodegen
+import org.jetbrains.kotlin.descriptors.ConstructorDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.load.java.BuiltinMethodsWithSpecialGenericSignature.getSpecialSignatureInfo
 import org.jetbrains.kotlin.load.kotlin.TypeMappingMode
@@ -25,7 +26,6 @@ import org.jetbrains.kotlin.psi.KtFunction
 import org.jetbrains.kotlin.psi.KtProperty
 import org.jetbrains.kotlin.psi.KtTypeParameterListOwner
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.JvmDeclarationOriginKind
-import org.jetbrains.kotlin.types.KotlinType
 
 internal abstract class KtUltraLightMethod(
     internal val delegate: PsiMethod,
@@ -38,6 +38,37 @@ internal abstract class KtUltraLightMethod(
     containingClass
 ), KtUltraLightElementWithNullabilityAnnotation<KtDeclaration, PsiMethod> {
 
+    private class KtUltraLightThrowsReferenceListBuilder(private val parentMethod: PsiMethod) :
+        KotlinLightReferenceListBuilder(parentMethod.manager, parentMethod.language, PsiReferenceList.Role.THROWS_LIST) {
+        override fun getParent() = parentMethod
+        override fun getContainingFile() = parentMethod.containingFile
+    }
+
+    protected fun computeThrowsList(methodDescriptor: FunctionDescriptor?): PsiReferenceList {
+        val builder = KtUltraLightThrowsReferenceListBuilder(parentMethod = this)
+
+        if (methodDescriptor !== null) {
+            for (ex in FunctionCodegen.getThrownExceptions(methodDescriptor)) {
+                val psiClassType = ex.defaultType.asPsiType(support, TypeMappingMode.DEFAULT, builder) as? PsiClassType
+                psiClassType ?: continue
+                builder.addReference(psiClassType)
+            }
+        }
+
+        return builder
+    }
+
+    protected fun computeCheckNeedToErasureParametersTypes(methodDescriptor: FunctionDescriptor?): Boolean {
+        return methodDescriptor
+            ?.getSpecialSignatureInfo()
+            ?.let { it.valueParametersSignature !== null }
+            ?: false
+    }
+
+    abstract override fun buildTypeParameterList(): PsiTypeParameterList
+
+    abstract val checkNeedToErasureParametersTypes: Boolean
+
     override val memberIndex: MemberIndex? = null
 
     override val psiTypeForNullabilityAnnotation: PsiType?
@@ -54,23 +85,6 @@ internal abstract class KtUltraLightMethod(
     // should be in super
     override fun isVarArgs() = PsiImplUtil.isVarArgs(this)
 
-    abstract override fun buildTypeParameterList(): PsiTypeParameterList
-
-    private val _throwsList: PsiReferenceList by lazyPub {
-        val list =
-            object : KotlinLightReferenceListBuilder(manager, language, PsiReferenceList.Role.THROWS_LIST) {
-                override fun getParent() = this@KtUltraLightMethod
-                override fun getContainingFile() = this@KtUltraLightMethod.containingFile
-            }
-        methodDescriptor?.let {
-            for (ex in FunctionCodegen.getThrownExceptions(it)) {
-                val psiClassType = ex.defaultType.asPsiType(support, TypeMappingMode.DEFAULT, list) as? PsiClassType ?: continue
-                list.addReference(psiClassType)
-            }
-        }
-        list
-    }
-
     private val _deprecated: Boolean by lazyPub { kotlinOrigin?.isDeprecated(support) ?: false }
 
     override fun getHierarchicalMethodSignature() = PsiSuperMethodImplUtil.getHierarchicalMethodSignature(this)
@@ -90,17 +104,6 @@ internal abstract class KtUltraLightMethod(
     override fun findSuperMethods(parentClass: PsiClass?): Array<out PsiMethod> =
         PsiSuperMethodImplUtil.findSuperMethods(this, parentClass)
 
-    override fun getThrowsList(): PsiReferenceList = _throwsList
-
-    abstract val methodDescriptor: FunctionDescriptor?
-
-    val checkNeedToErasureParametersTypes: Boolean by lazyPub {
-        methodDescriptor
-            ?.getSpecialSignatureInfo()
-            ?.let { it.valueParametersSignature !== null }
-            ?: false
-    }
-
     override fun equals(other: Any?): Boolean = this === other
 
     override fun hashCode(): Int = name.hashCode()
@@ -127,21 +130,29 @@ internal class KtUltraLightMethodForSourceDeclaration(
         containingClass: KtLightClass
     ) : this(delegate, LightMemberOriginForDeclaration(declaration, JvmDeclarationOriginKind.OTHER), support, containingClass)
 
-    override val kotlinTypeForNullabilityAnnotation: KotlinType?
-        get() = if (forceToSkipNullabilityAnnotation) null else kotlinOrigin?.getKotlinType()
+    override val qualifiedNameForNullabilityAnnotation: String?
+        get() {
+            val typeForAnnotation = if (forceToSkipNullabilityAnnotation) null else kotlinOrigin?.getKotlinType()
+            return computeQualifiedNameForNullabilityAnnotation(typeForAnnotation)
+        }
 
     override fun buildTypeParameterList(): PsiTypeParameterList {
         val origin = kotlinOrigin
         return if (origin is KtFunction || origin is KtProperty)
-            buildTypeParameterList(origin as KtTypeParameterListOwner, this, support)
+            buildTypeParameterListForSourceDeclaration(origin as KtTypeParameterListOwner, this, support)
         else LightTypeParameterListBuilder(manager, language)
     }
 
-    override val methodDescriptor = kotlinOrigin?.resolve() as? FunctionDescriptor
+    private val methodDescriptor get() = kotlinOrigin?.resolve() as? FunctionDescriptor
+
+    private val _throwsList: PsiReferenceList by lazyPub { computeThrowsList(methodDescriptor) }
+    override fun getThrowsList(): PsiReferenceList = _throwsList
+
+    override val checkNeedToErasureParametersTypes: Boolean by lazyPub { computeCheckNeedToErasureParametersTypes(methodDescriptor) }
 }
 
 internal class KtUltraLightMethodForDescriptor(
-    override val methodDescriptor: FunctionDescriptor,
+    methodDescriptor: FunctionDescriptor,
     delegate: LightMethodBuilder,
     lightMemberOrigin: LightMemberOrigin?,
     support: KtUltraLightSupport,
@@ -152,11 +163,62 @@ internal class KtUltraLightMethodForDescriptor(
     support,
     containingClass
 ) {
-    override fun buildTypeParameterList() = buildTypeParameterList(methodDescriptor, this, support)
+    // This is greedy realization of UL class.
+    // This means that all data that depends on descriptor evaluated in ctor so the descriptor will be released on the end.
+    // Be aware to save descriptor in class instance or any depending references
 
-    override val kotlinTypeForNullabilityAnnotation: KotlinType?
-        get() = methodDescriptor.returnType
+    private val lazyInitializers = mutableListOf<Lazy<*>>()
+    private inline fun <T> getAndAddLazy(crossinline initializer: () -> T): Lazy<T> =
+        lazyPub { initializer() }.also { lazyInitializers.add(it) }
 
-    override val givenAnnotations: List<KtLightAbstractAnnotation>
-        get() = methodDescriptor.obtainLightAnnotations(support, this)
+
+    private val _buildTypeParameterList by getAndAddLazy {
+        buildTypeParameterListForDescriptor(methodDescriptor, this, support)
+    }
+
+    override fun buildTypeParameterList() = _buildTypeParameterList
+
+    private val _throwsList: PsiReferenceList by getAndAddLazy {
+        computeThrowsList(methodDescriptor)
+    }
+
+    override fun getThrowsList(): PsiReferenceList = _throwsList
+
+    override val givenAnnotations: List<KtLightAbstractAnnotation> by getAndAddLazy {
+        methodDescriptor.obtainLightAnnotations(support, this)
+    }
+
+    override val qualifiedNameForNullabilityAnnotation: String? by getAndAddLazy {
+        computeQualifiedNameForNullabilityAnnotation(methodDescriptor.returnType)
+    }
+
+    override val checkNeedToErasureParametersTypes: Boolean by getAndAddLazy {
+        computeCheckNeedToErasureParametersTypes(methodDescriptor)
+    }
+
+    init {
+        methodDescriptor.extensionReceiverParameter?.let { receiver ->
+            delegate.addParameter(KtUltraLightParameterForDescriptor(receiver, support, this))
+        }
+
+        for (valueParameter in methodDescriptor.valueParameters) {
+            delegate.addParameter(KtUltraLightParameterForDescriptor(valueParameter, support, this))
+        }
+
+        val returnType = if (methodDescriptor is ConstructorDescriptor) {
+            delegate.isConstructor = true
+            PsiType.VOID
+        } else {
+            support.mapType(this) { typeMapper, signatureWriter ->
+                typeMapper.mapReturnType(methodDescriptor, signatureWriter)
+            }
+        }
+        delegate.setMethodReturnType(returnType)
+
+        //We should force computations on all lazy delegates to release descriptor on the end of ctor call
+        with(lazyInitializers) {
+            forEach { it.value }
+            clear()
+        }
+    }
 }

compiler/light-classes/src/org/jetbrains/kotlin/asJava/classes/ultraLightParameters.kt

@@ -27,16 +27,19 @@ internal class KtUltraLightSuspendContinuationParameter(
     KtLightParameter,
     KtUltraLightElementWithNullabilityAnnotation<KtParameter, PsiParameter> {
 
-    override val kotlinTypeForNullabilityAnnotation: KotlinType? get() = ktType
+    override val qualifiedNameForNullabilityAnnotation: String?
+        get() = computeQualifiedNameForNullabilityAnnotation(ktType)
+
     override val psiTypeForNullabilityAnnotation: PsiType? get() = psiType
     override val kotlinOrigin: KtParameter? = null
     override val clsDelegate: PsiParameter get() = invalidAccess()
 
-    private val ktType by lazyPub {
-        val descriptor = ktFunction.resolve() as? FunctionDescriptor
-        val returnType = descriptor?.returnType ?: return@lazyPub null
-        support.moduleDescriptor.getContinuationOfTypeOrAny(returnType, support.isReleasedCoroutine)
-    }
+    private val ktType: KotlinType?
+        get() {
+            val descriptor = ktFunction.resolve() as? FunctionDescriptor
+            val returnType = descriptor?.returnType ?: return null
+            return support.moduleDescriptor.getContinuationOfTypeOrAny(returnType, support.isReleasedCoroutine)
+        }
 
     private val psiType by lazyPub {
         ktType?.asPsiType(support, TypeMappingMode.DEFAULT, method) ?: PsiType.NULL
@@ -68,12 +71,12 @@ internal abstract class KtUltraLightParameter(
     name: String,
     override val kotlinOrigin: KtParameter?,
     protected val support: KtUltraLightSupport,
-    method: KtUltraLightMethod
+    private val ultraLightMethod: KtUltraLightMethod
 ) : org.jetbrains.kotlin.asJava.elements.LightParameter(
     name,
     PsiType.NULL,
-    method,
-    method.language
+    ultraLightMethod,
+    ultraLightMethod.language
 ), KtUltraLightElementWithNullabilityAnnotation<KtParameter, PsiParameter>, KtLightParameter {
 
     override fun isEquivalentTo(another: PsiElement?): Boolean = kotlinOrigin == another
@@ -89,41 +92,31 @@ internal abstract class KtUltraLightParameter(
 
     override fun isValid() = parent.isValid
 
-    protected abstract val kotlinType: KotlinType?
-    protected abstract val containingDescriptor: CallableDescriptor?
-
-    override val kotlinTypeForNullabilityAnnotation: KotlinType?
-        get() {
-            val type = kotlinType
-            return if (isVarArgs && type != null && KotlinBuiltIns.isArray(type)) {
-                type.arguments[0].type
-            } else {
-                type
-            }
-        }
+    override fun computeQualifiedNameForNullabilityAnnotation(kotlinType: KotlinType?): String? {
+        val typeForAnnotation =
+            if (isVarArgs && kotlinType != null && KotlinBuiltIns.isArray(kotlinType)) kotlinType.arguments[0].type else kotlinType
+        return super.computeQualifiedNameForNullabilityAnnotation(typeForAnnotation)
+    }
 
     override val psiTypeForNullabilityAnnotation: PsiType?
         get() = type
 
 
-    private val _type: PsiType by lazyPub {
-        val kotlinType = kotlinType ?: return@lazyPub PsiType.NULL
+    protected fun computeParameterType(kotlinType: KotlinType?, containingDeclaration: CallableDescriptor?): PsiType {
+        kotlinType ?: return PsiType.NULL
 
         if (kotlinType.isSuspendFunctionType) {
-            kotlinType.asPsiType(support, TypeMappingMode.DEFAULT, this)
+            return kotlinType.asPsiType(support, TypeMappingMode.DEFAULT, this)
         } else {
-            val containingDescriptor = containingDescriptor ?: return@lazyPub PsiType.NULL
+            val containingDescriptor = containingDeclaration ?: return PsiType.NULL
             val mappedType = support.mapType(this) { typeMapper, sw ->
                 typeMapper.writeParameterType(sw, kotlinType, containingDescriptor)
             }
-
-            if (method.checkNeedToErasureParametersTypes)
-                TypeConversionUtil.erasure(mappedType)
-            else mappedType
+            return if (ultraLightMethod.checkNeedToErasureParametersTypes) TypeConversionUtil.erasure(mappedType) else mappedType
         }
     }
 
-    override fun getType(): PsiType = _type
+    abstract override fun getType(): PsiType
 
     override fun getContainingFile(): PsiFile = method.containingFile
     override fun getParent(): PsiElement = method.parameterList
@@ -143,7 +136,21 @@ internal abstract class KtAbstractUltraLightParameterForDeclaration(
     method: KtUltraLightMethod,
     protected val containingDeclaration: KtCallableDeclaration
 ) : KtUltraLightParameter(name, kotlinOrigin, support, method) {
-    override val containingDescriptor: CallableDescriptor? = containingDeclaration.resolve() as? CallableMemberDescriptor
+
+    protected fun tryGetContainingDescriptor(): CallableDescriptor? =
+        containingDeclaration.resolve() as? CallableMemberDescriptor
+
+    protected abstract fun tryGetKotlinType(): KotlinType?
+
+    private val _parameterType: PsiType by lazyPub {
+        computeParameterType(tryGetKotlinType(), tryGetContainingDescriptor())
+    }
+
+    override fun getType(): PsiType = _parameterType
+
+    override val qualifiedNameForNullabilityAnnotation: String? by lazyPub {
+        computeQualifiedNameForNullabilityAnnotation(tryGetKotlinType())
+    }
 }
 
 internal class KtUltraLightParameterForSource(
@@ -154,9 +161,7 @@ internal class KtUltraLightParameterForSource(
     containingDeclaration: KtCallableDeclaration
 ) : KtAbstractUltraLightParameterForDeclaration(name, kotlinOrigin, support, method, containingDeclaration) {
 
-    override val kotlinType: KotlinType? by lazyPub {
-        kotlinOrigin.getKotlinType()
-    }
+    override fun tryGetKotlinType(): KotlinType? = kotlinOrigin.getKotlinType()
 
     override fun isVarArgs(): Boolean = kotlinOrigin.isVarArg && method.parameterList.parameters.last() == this
 
@@ -175,7 +180,7 @@ internal class KtUltraLightParameterForSetterParameter(
     containingDeclaration: KtCallableDeclaration
 ) : KtAbstractUltraLightParameterForDeclaration(name, null, support, method, containingDeclaration) {
 
-    override val kotlinType: KotlinType? by lazyPub { property.getKotlinType() }
+    override fun tryGetKotlinType(): KotlinType? = property.getKotlinType()
 
     override fun isVarArgs(): Boolean = false
 }
@@ -188,24 +193,51 @@ internal class KtUltraLightReceiverParameter(
 
     override fun isVarArgs(): Boolean = false
 
-    override val kotlinType: KotlinType? by lazyPub { containingDescriptor?.extensionReceiverParameter?.type }
+    override fun tryGetKotlinType(): KotlinType? =
+        tryGetContainingDescriptor()?.extensionReceiverParameter?.type
 }
 
 internal class KtUltraLightParameterForDescriptor(
-    private val descriptor: ParameterDescriptor,
+    descriptor: ParameterDescriptor,
     support: KtUltraLightSupport,
     method: KtUltraLightMethod
 ) : KtUltraLightParameter(
     if (descriptor.name.isSpecial) "\$self" else descriptor.name.identifier,
     null, support, method
 ) {
-    override val kotlinType: KotlinType?
-        get() = descriptor.type
+    // This is greedy realization of UL class.
+    // This means that all data that depends on descriptor evaluated in ctor so the descriptor will be released on the end.
+    // Be aware to save descriptor in class instance or any depending references
 
-    override val containingDescriptor: CallableDescriptor? = descriptor.containingDeclaration as? CallableMemberDescriptor
+    private val lazyInitializers = mutableListOf<Lazy<*>>()
+    private inline fun <T> getAndAddLazy(crossinline initializer: () -> T): Lazy<T> =
+        lazyPub { initializer() }.also { lazyInitializers.add(it) }
 
-    override fun isVarArgs() = (descriptor as? ValueParameterDescriptor)?.varargElementType != null
+    override val qualifiedNameForNullabilityAnnotation: String? by getAndAddLazy {
+        computeQualifiedNameForNullabilityAnnotation(descriptor.type)
+    }
 
-    override val givenAnnotations: List<KtLightAbstractAnnotation>
-        get() = descriptor.obtainLightAnnotations(support, this)
+    private val _isVarArgs: Boolean by getAndAddLazy {
+        (descriptor as? ValueParameterDescriptor)?.varargElementType != null
+    }
+
+    override fun isVarArgs() = _isVarArgs
+
+    override val givenAnnotations: List<KtLightAbstractAnnotation> by getAndAddLazy {
+        descriptor.obtainLightAnnotations(support, this)
+    }
+
+    private val _parameterType by getAndAddLazy {
+        computeParameterType(descriptor.type, descriptor.containingDeclaration as? CallableMemberDescriptor)
+    }
+
+    override fun getType(): PsiType = _parameterType
+
+    init {
+        //We should force computations on all lazy delegates to release descriptor on the end of ctor call
+        with(lazyInitializers) {
+            forEach { it.value }
+            clear()
+        }
+    }
 }

compiler/light-classes/src/org/jetbrains/kotlin/asJava/classes/ultraLightUtils.kt

@@ -51,53 +51,55 @@ import org.jetbrains.kotlin.types.typeUtil.supertypes
 import org.jetbrains.org.objectweb.asm.Opcodes
 import java.text.StringCharacterIterator
 
-internal fun buildTypeParameterList(
-    declaration: CallableMemberDescriptor,
-    owner: PsiTypeParameterListOwner,
-    support: KtUltraLightSupport
-): PsiTypeParameterList = buildTypeParameterList(
-    declaration, owner, support,
-    object : TypeParametersSupport<CallableMemberDescriptor, TypeParameterDescriptor> {
-        override fun parameters(declaration: CallableMemberDescriptor) = declaration.typeParameters
-
-        override fun name(typeParameter: TypeParameterDescriptor) = typeParameter.name.asString()
-
-        override fun hasNonTrivialBounds(
-            declaration: CallableMemberDescriptor,
-            typeParameter: TypeParameterDescriptor
-        ) = typeParameter.upperBounds.any { !KotlinBuiltIns.isDefaultBound(it) }
-
-        override fun asDescriptor(typeParameter: TypeParameterDescriptor) = typeParameter
-    }
-)
-
-internal fun buildTypeParameterList(
-    declaration: KtTypeParameterListOwner,
-    owner: PsiTypeParameterListOwner,
-    support: KtUltraLightSupport
-): PsiTypeParameterList = buildTypeParameterList(
-    declaration, owner, support,
-    object : TypeParametersSupport<KtTypeParameterListOwner, KtTypeParameter> {
-        override fun parameters(declaration: KtTypeParameterListOwner) = declaration.typeParameters
-        override fun name(typeParameter: KtTypeParameter) = typeParameter.name
-
-        override fun hasNonTrivialBounds(
-            declaration: KtTypeParameterListOwner,
-            typeParameter: KtTypeParameter
-        ) = typeParameter.extendsBound != null || declaration.typeConstraints.isNotEmpty()
-
-        override fun asDescriptor(typeParameter: KtTypeParameter) = typeParameter.resolve() as? TypeParameterDescriptor
-    }
-)
-
-interface TypeParametersSupport<D, T> {
+private interface TypeParametersSupport<D, T> {
     fun parameters(declaration: D): List<T>
     fun name(typeParameter: T): String?
     fun hasNonTrivialBounds(declaration: D, typeParameter: T): Boolean
     fun asDescriptor(typeParameter: T): TypeParameterDescriptor?
 }
 
-internal fun <D, T> buildTypeParameterList(
+private val supportForDescriptor = object : TypeParametersSupport<CallableMemberDescriptor, TypeParameterDescriptor> {
+
+    override fun parameters(declaration: CallableMemberDescriptor) = declaration.typeParameters
+
+    override fun name(typeParameter: TypeParameterDescriptor) = typeParameter.name.asString()
+
+    override fun hasNonTrivialBounds(
+        declaration: CallableMemberDescriptor,
+        typeParameter: TypeParameterDescriptor
+    ) = typeParameter.upperBounds.any { !KotlinBuiltIns.isDefaultBound(it) }
+
+    override fun asDescriptor(typeParameter: TypeParameterDescriptor) = typeParameter
+}
+
+private val supportForSourceDeclaration = object : TypeParametersSupport<KtTypeParameterListOwner, KtTypeParameter> {
+
+    override fun parameters(declaration: KtTypeParameterListOwner) = declaration.typeParameters
+
+    override fun name(typeParameter: KtTypeParameter) = typeParameter.name
+
+    override fun hasNonTrivialBounds(
+        declaration: KtTypeParameterListOwner,
+        typeParameter: KtTypeParameter
+    ) = typeParameter.extendsBound != null || declaration.typeConstraints.isNotEmpty()
+
+    override fun asDescriptor(typeParameter: KtTypeParameter) = typeParameter.resolve() as? TypeParameterDescriptor
+}
+
+internal fun buildTypeParameterListForDescriptor(
+    declaration: CallableMemberDescriptor,
+    owner: PsiTypeParameterListOwner,
+    support: KtUltraLightSupport
+): PsiTypeParameterList = buildTypeParameterList(declaration, owner, support, supportForDescriptor)
+
+
+internal fun buildTypeParameterListForSourceDeclaration(
+    declaration: KtTypeParameterListOwner,
+    owner: PsiTypeParameterListOwner,
+    support: KtUltraLightSupport
+): PsiTypeParameterList = buildTypeParameterList(declaration, owner, support, supportForSourceDeclaration)
+
+private fun <D, T> buildTypeParameterList(
     declaration: D,
     owner: PsiTypeParameterListOwner,
     support: KtUltraLightSupport,
@@ -226,35 +228,15 @@ fun KtUltraLightClass.createGeneratedMethodFromDescriptor(
     descriptor: FunctionDescriptor,
     declarationForOrigin: KtDeclaration? = null
 ): KtLightMethod {
-    val lightMethod = lightMethod(descriptor)
+
     val kotlinOrigin =
         declarationForOrigin
             ?: DescriptorToSourceUtils.descriptorToDeclaration(descriptor) as? KtDeclaration
             ?: kotlinOrigin
 
     val lightMemberOrigin = LightMemberOriginForDeclaration(kotlinOrigin, JvmDeclarationOriginKind.OTHER)
-    val wrapper = KtUltraLightMethodForDescriptor(descriptor, lightMethod, lightMemberOrigin, support, this)
 
-    descriptor.extensionReceiverParameter?.let { receiver ->
-        lightMethod.addParameter(KtUltraLightParameterForDescriptor(receiver, support, wrapper))
-    }
-
-    for (valueParameter in descriptor.valueParameters) {
-        lightMethod.addParameter(KtUltraLightParameterForDescriptor(valueParameter, support, wrapper))
-    }
-
-    if (descriptor is ConstructorDescriptor) {
-        lightMethod.isConstructor = true
-        lightMethod.setMethodReturnType(PsiType.VOID)
-    } else {
-        lightMethod.setMethodReturnType {
-            support.mapType(wrapper) { typeMapper, signatureWriter ->
-                typeMapper.mapReturnType(descriptor, signatureWriter)
-            }
-        }
-    }
-
-    return wrapper
+    return KtUltraLightMethodForDescriptor(descriptor, lightMethod(descriptor), lightMemberOrigin, support, this)
 }
 
 private fun KtUltraLightClass.lightMethod(

idea/idea-analysis/src/org/jetbrains/kotlin/idea/caches/resolve/IDELightClassGenerationSupport.kt

@@ -1,17 +1,6 @@
 /*
- * Copyright 2010-2016 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * 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.idea.caches.resolve
@@ -65,9 +54,9 @@ class IDELightClassGenerationSupport(private val project: Project) : LightClassG
         override val isReleasedCoroutine
             get() = module?.languageVersionSettings?.supportsFeature(LanguageFeature.ReleaseCoroutines) ?: true
 
-        override val moduleDescriptor by lazyPub {
-            element.getResolutionFacade().moduleDescriptor
-        }
+        private val resolutionFacade get() = element.getResolutionFacade()
+
+        override val moduleDescriptor get() = resolutionFacade.moduleDescriptor
 
         override val moduleName: String by lazyPub {
             JvmCodegenUtil.getModuleName(moduleDescriptor)
@@ -102,9 +91,8 @@ class IDELightClassGenerationSupport(private val project: Project) : LightClassG
             return null
         }
 
-        override val deprecationResolver: DeprecationResolver by lazyPub {
-            element.getResolutionFacade().getFrontendService(DeprecationResolver::class.java)
-        }
+        override val deprecationResolver: DeprecationResolver get() = resolutionFacade.getFrontendService(DeprecationResolver::class.java)
+
 
         override val typeMapper: KotlinTypeMapper by lazyPub {
             KotlinTypeMapper(

idea/tests/org/jetbrains/kotlin/asJava/classes/AbstractUltraLightClassLoadingTest.kt

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.asJava.classes
 import com.intellij.testFramework.LightProjectDescriptor
 import org.jetbrains.kotlin.asJava.LightClassGenerationSupport
 import org.jetbrains.kotlin.idea.perf.UltraLightChecker
+import org.jetbrains.kotlin.idea.perf.UltraLightChecker.checkDescriptorsLeak
 import org.jetbrains.kotlin.idea.test.KotlinLightCodeInsightFixtureTestCase
 import org.jetbrains.kotlin.idea.test.KotlinWithJdkAndRuntimeLightProjectDescriptor
 import org.jetbrains.kotlin.psi.KtFile
@@ -30,7 +31,9 @@ abstract class AbstractUltraLightClassLoadingTest : KotlinLightCodeInsightFixtur
                     LightClassGenerationSupport.getInstance(ktClass.project).createUltraLightClass(ktClass)?.let { it to ktClass }
                 }.joinToString("\n\n") { (ultraLightClass, ktClass) ->
                     with(UltraLightChecker) {
-                        ultraLightClass.renderClass()
+                        ultraLightClass.renderClass().also {
+                            checkDescriptorsLeak(ultraLightClass)
+                        }
                     }
                 }
 
@@ -39,7 +42,10 @@ abstract class AbstractUltraLightClassLoadingTest : KotlinLightCodeInsightFixtur
         }
 
         for (ktClass in UltraLightChecker.allClasses(file)) {
-            UltraLightChecker.checkClassEquivalence(ktClass)
+            val ultraLightClass = UltraLightChecker.checkClassEquivalence(ktClass)
+            if (ultraLightClass != null) {
+                checkDescriptorsLeak(ultraLightClass)
+            }
         }
 
     }

idea/tests/org/jetbrains/kotlin/asJava/classes/AbstractUltraLightFacadeClassLoadingTest.kt

@@ -33,7 +33,10 @@ abstract class AbstractUltraLightFacadeClassTest : KotlinLightCodeInsightFixture
         val facades = KotlinAsJavaSupport.getInstance(project).getFacadeNames(FqName.ROOT, scope)
 
         for (facadeName in facades) {
-            UltraLightChecker.checkFacadeEquivalence(FqName(facadeName), scope, project)
+            val ultraLightClass = UltraLightChecker.checkFacadeEquivalence(FqName(facadeName), scope, project)
+            if (ultraLightClass != null) {
+                UltraLightChecker.checkDescriptorsLeak(ultraLightClass)
+            }
         }
     }
 }

idea/tests/org/jetbrains/kotlin/idea/perf/UltraLightChecker.kt

@@ -8,23 +8,29 @@ package org.jetbrains.kotlin.idea.perf
 import com.intellij.openapi.Disposable
 import com.intellij.openapi.module.Module
 import com.intellij.openapi.project.Project
+import com.intellij.openapi.util.Conditions
 import com.intellij.openapi.util.Disposer
 import com.intellij.psi.*
+import com.intellij.psi.impl.light.LightElement
 import com.intellij.psi.search.GlobalSearchScope
+import com.intellij.psi.util.PsiTreeUtil
 import com.intellij.testFramework.UsefulTestCase
+import com.intellij.util.PairProcessor
+import com.intellij.util.ref.DebugReflectionUtil
 import junit.framework.TestCase
 import org.jetbrains.kotlin.asJava.LightClassGenerationSupport
 import org.jetbrains.kotlin.asJava.classes.*
 import org.jetbrains.kotlin.asJava.elements.KtLightNullabilityAnnotation
 import org.jetbrains.kotlin.asJava.elements.KtLightPsiArrayInitializerMemberValue
 import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.idea.project.languageVersionSettings
 import org.jetbrains.kotlin.load.kotlin.NON_EXISTENT_CLASS_NAME
 import org.jetbrains.kotlin.name.FqName
-import org.jetbrains.kotlin.psi.KtCallExpression
 import org.jetbrains.kotlin.psi.KtClassOrObject
 import org.jetbrains.kotlin.psi.KtFile
 import org.junit.Assert
+import kotlin.test.assertFails
 
 fun UsefulTestCase.forceUsingOldLightClassesForTest() {
     KtUltraLightSupport.forceUsingOldLightClasses = true
@@ -263,4 +269,29 @@ object UltraLightChecker {
     }
 
     private fun String.prependDefaultIndent() = prependIndent("  ")
-}
+
+    private fun checkDescriptorLeakOnElement(element: PsiElement) {
+        DebugReflectionUtil.walkObjects(
+            10,
+            mapOf(element to element.javaClass.name),
+            Any::class.java,
+            Conditions.alwaysTrue(),
+            PairProcessor { value, backLink ->
+                if (value is DeclarationDescriptor) {
+                    assertFails {
+                        """Leaked descriptor ${value.javaClass.name} in ${element.javaClass.name}\n$backLink"""
+                    }
+                }
+                true
+            })
+    }
+
+    fun checkDescriptorsLeak(lightClass: KtLightClass) {
+        checkDescriptorLeakOnElement(lightClass)
+        lightClass.methods.forEach {
+            checkDescriptorLeakOnElement(it)
+            it.parameterList.parameters.forEach { parameter -> checkDescriptorLeakOnElement(parameter) }
+        }
+        lightClass.fields.forEach { checkDescriptorLeakOnElement(it) }
+    }
+}