Add synthetic constructors to class member scope, so they won't fly 'in the air' in the backends

This is required mainly for Native compiler since it wont't work correctly on descriptors that are not present in the class.

compiler/backend/src/org/jetbrains/kotlin/codegen/ConstructorCodegen.java

@@ -130,6 +130,8 @@ public class ConstructorCodegen {
         ConstructorContext constructorContext = context.intoConstructor(constructorDescriptor, typeMapper);
 
         KtSecondaryConstructor constructor = (KtSecondaryConstructor) descriptorToDeclaration(constructorDescriptor);
+        // Synthetic constructors don't have corresponding declarations
+        if (constructor == null) return;
 
         functionCodegen.generateMethod(
                 JvmDeclarationOriginKt.OtherOrigin(constructor, constructorDescriptor),

compiler/frontend/src/org/jetbrains/kotlin/psi/synthetics/SyntheticClassOrObjectDescriptor.kt

@@ -44,6 +44,7 @@ class SyntheticClassOrObjectDescriptor(
     outerScope: LexicalScope,
     private val modality: Modality,
     private val visibility: Visibility,
+    override val annotations: Annotations,
     constructorVisibility: Visibility,
     private val kind: ClassKind,
     private val isCompanionObject: Boolean
@@ -71,8 +72,6 @@ class SyntheticClassOrObjectDescriptor(
         this.typeParameters = typeParameters
     }
 
-    override val annotations: Annotations get() = Annotations.EMPTY
-
     override fun getModality() = modality
     override fun getVisibility() = visibility
     override fun getKind() = kind

compiler/frontend/src/org/jetbrains/kotlin/resolve/extensions/SyntheticResolveExtension.kt

@@ -17,10 +17,7 @@
 package org.jetbrains.kotlin.resolve.extensions
 
 import com.intellij.openapi.project.Project
-import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.descriptors.PackageFragmentDescriptor
-import org.jetbrains.kotlin.descriptors.PropertyDescriptor
-import org.jetbrains.kotlin.descriptors.SimpleFunctionDescriptor
 import org.jetbrains.kotlin.extensions.ProjectExtensionDescriptor
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.BindingContext
@@ -113,6 +110,22 @@ interface SyntheticResolveExtension {
                             )
                         }
                     }
+
+                override fun generateSyntheticSecondaryConstructors(
+                    thisDescriptor: ClassDescriptor,
+                    bindingContext: BindingContext,
+                    result: MutableCollection<ClassConstructorDescriptor>
+                ) {
+                    instances.forEach {
+                        withLinkageErrorLogger(it) {
+                            generateSyntheticSecondaryConstructors(
+                                thisDescriptor,
+                                bindingContext,
+                                result
+                            )
+                        }
+                    }
+                }
             }
         }
     }
@@ -160,4 +173,11 @@ interface SyntheticResolveExtension {
         result: MutableSet<PropertyDescriptor>
     ) {
     }
+
+    fun generateSyntheticSecondaryConstructors(
+        thisDescriptor: ClassDescriptor,
+        bindingContext: BindingContext,
+        result: MutableCollection<ClassConstructorDescriptor>
+    ) {
+    }
 }

compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassDescriptor.java

@@ -444,7 +444,7 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements ClassDes
                 /* parentClassOrObject= */ classOrObject,
                 this, syntheticCompanionName, getSource(),
                 /* outerScope= */ getOuterScope(),
-                Modality.FINAL, PUBLIC, PRIVATE, ClassKind.OBJECT, true);
+                Modality.FINAL, PUBLIC, Annotations.Companion.getEMPTY(), PRIVATE, ClassKind.OBJECT, true);
         companionDescriptor.initialize();
         return companionDescriptor;
     }

compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassMemberScope.kt

@@ -415,7 +415,18 @@ open class LazyClassMemberScope(
     }
 
     private val secondaryConstructors: NotNullLazyValue<Collection<ClassConstructorDescriptor>> =
-        c.storageManager.createLazyValue { resolveSecondaryConstructors() }
+        c.storageManager.createLazyValue { doGetConstructors() }
+
+    private fun doGetConstructors(): Collection<ClassConstructorDescriptor> {
+        val result = mutableListOf<ClassConstructorDescriptor>()
+        result.addAll(resolveSecondaryConstructors())
+        addSyntheticSecondaryConstructors(result)
+        return result
+    }
+
+    private fun addSyntheticSecondaryConstructors(result: MutableCollection<ClassConstructorDescriptor>) {
+        c.syntheticResolveExtension.generateSyntheticSecondaryConstructors(thisDescriptor, trace.bindingContext, result)
+    }
 
     fun getConstructors(): Collection<ClassConstructorDescriptor> {
         val result = secondaryConstructors()

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/backend/common/SerializableCodegen.kt

@@ -20,10 +20,8 @@ import org.jetbrains.kotlin.descriptors.ClassConstructorDescriptor
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.resolve.BindingContext
-import org.jetbrains.kotlinx.serialization.compiler.resolve.KSerializerDescriptorResolver
+import org.jetbrains.kotlin.resolve.descriptorUtil.secondaryConstructors
-import org.jetbrains.kotlinx.serialization.compiler.resolve.SerializableProperties
+import org.jetbrains.kotlinx.serialization.compiler.resolve.*
-import org.jetbrains.kotlinx.serialization.compiler.resolve.classSerializer
-import org.jetbrains.kotlinx.serialization.compiler.resolve.isAbstractSerializableClass
 
 abstract class SerializableCodegen(
     protected val serializableDescriptor: ClassDescriptor,
@@ -39,7 +37,7 @@ abstract class SerializableCodegen(
     private fun generateSyntheticInternalConstructor() {
         val serializerDescriptor = serializableDescriptor.classSerializer ?: return
         if (isAbstractSerializableClass(serializableDescriptor) || SerializerCodegen.getSyntheticLoadMember(serializerDescriptor) != null) {
-            val constrDesc = KSerializerDescriptorResolver.createLoadConstructorDescriptor(serializableDescriptor, bindingContext)
+            val constrDesc = serializableDescriptor.secondaryConstructors.find(ClassConstructorDescriptor::isSerializationCtor) ?: return
             generateInternalConstructor(constrDesc)
         }
     }
@@ -57,4 +55,4 @@ abstract class SerializableCodegen(
     protected open fun generateWriteSelfMethod(methodDescriptor: FunctionDescriptor) {
 
     }
-}
+}

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/backend/common/SerializerCodegen.kt

@@ -24,7 +24,6 @@ import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameUnsafe
 import org.jetbrains.kotlin.resolve.scopes.getDescriptorsFiltered
 import org.jetbrains.kotlinx.serialization.compiler.resolve.*
-import org.jetbrains.kotlinx.serialization.compiler.resolve.KSerializerDescriptorResolver.findSerializerConstructorForTypeArgumentsSerializers
 
 abstract class SerializerCodegen(
     protected val serializerDescriptor: ClassDescriptor,

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/backend/ir/GeneratorHelpers.kt

@@ -18,9 +18,12 @@ import org.jetbrains.kotlin.ir.declarations.impl.IrValueParameterImpl
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.*
-import org.jetbrains.kotlin.ir.types.*
+import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.impl.IrSimpleTypeImpl
 import org.jetbrains.kotlin.ir.types.impl.makeTypeProjection
+import org.jetbrains.kotlin.ir.types.makeNotNull
+import org.jetbrains.kotlin.ir.types.toKotlinType
+import org.jetbrains.kotlin.ir.types.typeWith
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.js.resolve.diagnostics.findPsi
 import org.jetbrains.kotlin.name.ClassId
@@ -77,6 +80,7 @@ interface IrBuilderExtension {
     fun IrClass.contributeConstructor(
         descriptor: ClassConstructorDescriptor,
         fromStubs: Boolean = false,
+        overwriteValueParameters: Boolean = false,
         bodyGen: IrBlockBodyBuilder.(IrConstructor) -> Unit
     ) {
         val c = if (!fromStubs) compilerContext.localSymbolTable.declareConstructor(
@@ -87,7 +91,7 @@ interface IrBuilderExtension {
         ) else compilerContext.externalSymbols.referenceConstructor(descriptor).owner
         c.parent = this
         c.returnType = descriptor.returnType.toIrType()
-        if (!fromStubs) c.createParameterDeclarations(receiver = null)
+        if (!fromStubs || overwriteValueParameters) c.createParameterDeclarations(receiver = null, overwriteValueParameters = overwriteValueParameters)
         if (c.typeParameters.isEmpty()) {
             c.copyTypeParamsFromDescriptor()
         }
@@ -346,7 +350,7 @@ interface IrBuilderExtension {
         }
     }
 
-    fun IrFunction.createParameterDeclarations(receiver: IrValueParameter?) {
+    fun IrFunction.createParameterDeclarations(receiver: IrValueParameter?, overwriteValueParameters: Boolean = false) {
         fun ParameterDescriptor.irValueParameter() = IrValueParameterImpl(
             this@createParameterDeclarations.startOffset, this@createParameterDeclarations.endOffset,
             SERIALIZABLE_PLUGIN_ORIGIN,
@@ -360,8 +364,11 @@ interface IrBuilderExtension {
         dispatchReceiverParameter = descriptor.dispatchReceiverParameter?.irValueParameter()
         extensionReceiverParameter = descriptor.extensionReceiverParameter?.irValueParameter()
 
-        assert(valueParameters.isEmpty())
+        if (!overwriteValueParameters)
-        descriptor.valueParameters.mapTo(valueParameters) { it.irValueParameter() }
+            assert(valueParameters.isEmpty())
+        else
+            valueParameters.clear()
+        valueParameters.addAll(descriptor.valueParameters.map { it.irValueParameter() })
 
         assert(typeParameters.isEmpty())
         copyTypeParamsFromDescriptor()
@@ -524,7 +531,7 @@ interface IrBuilderExtension {
             val serializable = getSerializableClassDescriptorBySerializer(serializerClass)
             val ctor = if (serializable?.declaredTypeParameters?.isNotEmpty() == true) {
                 requireNotNull(
-                    KSerializerDescriptorResolver.findSerializerConstructorForTypeArgumentsSerializers(serializerClass)
+                    findSerializerConstructorForTypeArgumentsSerializers(serializerClass)
                 ) { "Generated serializer does not have constructor with required number of arguments" }
                     .let { compilerContext.externalSymbols.referenceConstructor(it) }
             } else {
@@ -537,5 +544,5 @@ interface IrBuilderExtension {
     }
 
     fun IrClass.serializableSyntheticConstructor(): IrConstructorSymbol =
-        this.constructors.single { it.origin == SERIALIZABLE_PLUGIN_ORIGIN }.symbol
+        this.constructors.single { it.descriptor.isSerializationCtor() }.symbol
 }

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/backend/ir/SerializableCompanionIrGenerator.kt

@@ -58,7 +58,7 @@ class SerializableCompanionIrGenerator(
                 }
                 else -> {
                     val desc = requireNotNull(
-                        KSerializerDescriptorResolver.findSerializerConstructorForTypeArgumentsSerializers(serializer)
+                        findSerializerConstructorForTypeArgumentsSerializers(serializer)
                     ) { "Generated serializer does not have constructor with required number of arguments" }
                     val ctor = compilerContext.externalSymbols.referenceConstructor(desc)
                     val typeArgs = getter.typeParameters.map { it.defaultType }

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/backend/ir/SerializableIrGenerator.kt

@@ -38,7 +38,7 @@ class SerializableIrGenerator(
         get() = _table
 
     override fun generateInternalConstructor(constructorDescriptor: ClassConstructorDescriptor) =
-        irClass.contributeConstructor(constructorDescriptor) { ctor ->
+        irClass.contributeConstructor(constructorDescriptor, fromStubs = true, overwriteValueParameters = true) { ctor ->
             val transformFieldInitializer = buildInitializersRemapping(irClass)
 
             // Missing field exception parts

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/backend/js/JsCodegenUtil.kt

@@ -158,7 +158,7 @@ internal fun SerializerJsTranslator.serializerInstance(
         val serializable = getSerializableClassDescriptorBySerializer(serializerClass)
         val ref = if (serializable?.declaredTypeParameters?.isNotEmpty() == true) {
             val desc = requireNotNull(
-                KSerializerDescriptorResolver.findSerializerConstructorForTypeArgumentsSerializers(serializerClass)
+                findSerializerConstructorForTypeArgumentsSerializers(serializerClass)
             ) { "Generated serializer does not have constructor with required number of arguments" }
             if (!desc.isPrimary)
                 JsInvocation(context.getInnerReference(desc), args)

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/backend/js/SerializableCompanionJsTranslator.kt

@@ -46,7 +46,7 @@ class SerializableCompanionJsTranslator(
                     val args = jsFun.parameters.map { JsNameRef(it.name) }
                     val ref = context.getInnerNameForDescriptor(
                         requireNotNull(
-                            KSerializerDescriptorResolver.findSerializerConstructorForTypeArgumentsSerializers(serializer)
+                            findSerializerConstructorForTypeArgumentsSerializers(serializer)
                         ) { "Generated serializer does not have constructor with required number of arguments" })
                     JsInvocation(ref.makeRef(), args)
                 }

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/extensions/SerializationResolveExtension.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlinx.serialization.compiler.extensions
 
+import org.jetbrains.kotlin.descriptors.ClassConstructorDescriptor
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import org.jetbrains.kotlin.descriptors.SimpleFunctionDescriptor
@@ -69,6 +70,16 @@ open class SerializationResolveExtension : SyntheticResolveExtension {
         KSerializerDescriptorResolver.addSerializerSupertypes(thisDescriptor, supertypes)
     }
 
+    override fun generateSyntheticSecondaryConstructors(
+        thisDescriptor: ClassDescriptor,
+        bindingContext: BindingContext,
+        result: MutableCollection<ClassConstructorDescriptor>
+    ) {
+        if (thisDescriptor.isInternalSerializable) {
+            result.add(KSerializerDescriptorResolver.createLoadConstructorDescriptor(thisDescriptor, bindingContext))
+        }
+    }
+
     override fun generateSyntheticMethods(
         thisDescriptor: ClassDescriptor,
         name: Name,

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/resolve/KSerializationUtil.kt

@@ -18,13 +18,9 @@ package org.jetbrains.kotlinx.serialization.compiler.resolve
 
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.descriptors.annotations.Annotated
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
-import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.psi.ValueArgument
-import org.jetbrains.kotlin.resolve.constants.KClassValue
 import org.jetbrains.kotlin.resolve.descriptorUtil.classId
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
 import org.jetbrains.kotlin.resolve.lazy.descriptors.LazyAnnotationDescriptor
@@ -37,7 +33,6 @@ import org.jetbrains.kotlinx.serialization.compiler.backend.jvm.enumSerializerId
 import org.jetbrains.kotlinx.serialization.compiler.backend.jvm.polymorphicSerializerId
 import org.jetbrains.kotlinx.serialization.compiler.resolve.SerialEntityNames.KSERIALIZER_CLASS
 import org.jetbrains.kotlinx.serialization.compiler.resolve.SerializationAnnotations.serialInfoFqName
-import org.jetbrains.kotlinx.serialization.compiler.resolve.SerializationPackages.packageFqName
 
 internal fun isAllowedToHaveAutoGeneratedSerializerMethods(
     classDescriptor: ClassDescriptor,
@@ -219,59 +214,3 @@ internal fun ClassDescriptor.checkLoadMethodParameters(parameters: List<ValuePar
 
 internal fun ClassDescriptor.checkLoadMethodResult(type: KotlinType): Boolean =
     getSerializableClassDescriptorBySerializer(this)?.defaultType == type
-
-// ----------------
-
-inline fun <reified R> Annotations.findAnnotationConstantValue(annotationFqName: FqName, property: String): R? =
-    findAnnotation(annotationFqName)?.let { annotation ->
-        annotation.allValueArguments.entries.singleOrNull { it.key.asString() == property }?.value?.value
-    } as? R
-
-internal fun Annotations.findAnnotationKotlinTypeValue(
-    annotationFqName: FqName,
-    moduleForResolve: ModuleDescriptor,
-    property: String
-): KotlinType? =
-    findAnnotation(annotationFqName)?.let { annotation ->
-        val maybeKClass = annotation.allValueArguments.entries.singleOrNull { it.key.asString() == property }?.value as? KClassValue
-        maybeKClass?.getArgumentType(moduleForResolve)
-    }
-
-// Search utils
-
-internal fun ClassDescriptor.getKSerializerConstructorMarker(): ClassDescriptor =
-        module.findClassAcrossModuleDependencies(ClassId(packageFqName, SerialEntityNames.SERIAL_CTOR_MARKER_NAME))!!
-
-internal fun ModuleDescriptor.getClassFromInternalSerializationPackage(classSimpleName: String) =
-    getFromPackage(SerializationPackages.internalPackageFqName, classSimpleName)
-
-internal fun ModuleDescriptor.getClassFromSerializationPackage(classSimpleName: String) =
-    getFromPackage(SerializationPackages.packageFqName, classSimpleName)
-
-private fun ModuleDescriptor.getFromPackage(packageFqName: FqName, classSimpleName: String) = requireNotNull(
-    findClassAcrossModuleDependencies(
-        ClassId(
-            packageFqName,
-            Name.identifier(classSimpleName)
-        )
-    )
-) { "Can't locate class $classSimpleName from package $packageFqName" }
-
-internal fun ClassDescriptor.getClassFromSerializationPackage(classSimpleName: String) =
-        requireNotNull(module.findClassAcrossModuleDependencies(ClassId(packageFqName, Name.identifier(classSimpleName)))) {"Can't locate class $classSimpleName"}
-
-internal fun ClassDescriptor.getClassFromInternalSerializationPackage(classSimpleName: String) =
-    module.getClassFromInternalSerializationPackage(classSimpleName)
-
-fun ClassDescriptor.toSimpleType(nullable: Boolean = true) = KotlinTypeFactory.simpleType(Annotations.EMPTY, this.typeConstructor, emptyList(), nullable)
-
-internal fun Annotated.annotationsWithArguments(): List<Triple<ClassDescriptor, List<ValueArgument>, List<ValueParameterDescriptor>>> =
-    annotations.asSequence()
-        .filter { it.type.toClassDescriptor?.isSerialInfoAnnotation == true }
-        .filterIsInstance<LazyAnnotationDescriptor>()
-        .mapNotNull { annDesc ->
-            annDesc.type.toClassDescriptor?.let {
-                Triple(it, annDesc.annotationEntry.valueArguments, it.unsubstitutedPrimaryConstructor?.valueParameters.orEmpty())
-            }
-        }
-        .toList()

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/resolve/KSerializerDescriptorResolver.kt

@@ -18,8 +18,10 @@ package org.jetbrains.kotlinx.serialization.compiler.resolve
 
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptorImpl
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
+import org.jetbrains.kotlin.descriptors.annotations.createDeprecatedAnnotation
 import org.jetbrains.kotlin.descriptors.impl.*
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.name.ClassId
@@ -47,6 +49,10 @@ import java.util.*
 
 object KSerializerDescriptorResolver {
 
+    private fun createDeprecatedHiddenAnnotation(module: ModuleDescriptor): AnnotationDescriptor {
+        return module.builtIns.createDeprecatedAnnotation("This synthesized declaration should not be used directly", level = "HIDDEN")
+    }
+
     fun isSerialInfoImpl(thisDescriptor: ClassDescriptor): Boolean {
         return thisDescriptor.name == IMPL_NAME
                && thisDescriptor.containingDeclaration is LazyClassDescriptor
@@ -92,6 +98,7 @@ object KSerializerDescriptorResolver {
             scope,
             Modality.FINAL,
             Visibilities.PUBLIC,
+            Annotations.create(listOf(createDeprecatedHiddenAnnotation(interfaceDesc.module))),
             primaryCtorVisibility,
             ClassKind.CLASS,
             false
@@ -114,7 +121,9 @@ object KSerializerDescriptorResolver {
             thisDeclaration,
             thisDescriptor, SERIALIZER_CLASS_NAME, thisDescriptor.source,
             scope,
-            Modality.FINAL, Visibilities.PUBLIC, Visibilities.PRIVATE,
+            Modality.FINAL, Visibilities.PUBLIC,
+            Annotations.create(listOf(createDeprecatedHiddenAnnotation(thisDescriptor.module))),
+            Visibilities.PRIVATE,
             serializerKind, false
         )
         val typeParameters: List<TypeParameterDescriptor> =
@@ -276,9 +285,9 @@ object KSerializerDescriptorResolver {
 
         val functionDescriptor = ClassConstructorDescriptorImpl.createSynthesized(
             classDescriptor,
-            Annotations.EMPTY,
+            Annotations.create(listOf(createDeprecatedHiddenAnnotation(classDescriptor.module))),
             false,
-            classDescriptor.source
+            SourceElement.NO_SOURCE
         )
 
         val markerDesc = classDescriptor.getKSerializerConstructorMarker()
@@ -314,29 +323,13 @@ object KSerializerDescriptorResolver {
 
         functionDescriptor.initialize(
             consParams,
-            Visibilities.PUBLIC
+            Visibilities.INTERNAL
         )
 
         functionDescriptor.returnType = classDescriptor.defaultType
         return functionDescriptor
     }
 
-    // finds constructor (KSerializer<T0>, KSerializer<T1>...) on a KSerializer<T<T0, T1...>>
-    fun findSerializerConstructorForTypeArgumentsSerializers(
-        serializerDescriptor: ClassDescriptor,
-        onlyIfSynthetic: Boolean = false
-    ): ClassConstructorDescriptor? {
-        val serializableImplementationTypeArguments = extractKSerializerArgumentFromImplementation(serializerDescriptor)?.arguments
-            ?: throw AssertionError("Serializer does not implement KSerializer??")
-
-        val typeParamsCount = serializableImplementationTypeArguments.size
-        if (typeParamsCount == 0) return null //don't need it
-        val ctor = serializerDescriptor.constructors.find { ctor ->
-            ctor.valueParameters.size == typeParamsCount && ctor.valueParameters.all { isKSerializer(it.type) }
-        }
-        return if (!onlyIfSynthetic) ctor else ctor?.takeIf { it.kind == CallableMemberDescriptor.Kind.SYNTHESIZED }
-    }
-
     private fun createTypedSerializerConstructorDescriptor(
         classDescriptor: ClassDescriptor,
         serializableDescriptor: ClassDescriptor,
@@ -344,7 +337,7 @@ object KSerializerDescriptorResolver {
     ): ClassConstructorDescriptor {
         val constrDesc = ClassConstructorDescriptorImpl.createSynthesized(
             classDescriptor,
-            Annotations.EMPTY,
+            Annotations.create(listOf(createDeprecatedHiddenAnnotation(classDescriptor.module))),
             false,
             classDescriptor.source
         )
@@ -437,8 +430,8 @@ object KSerializerDescriptorResolver {
 
 
     private fun KotlinType.makeNullableIfNotPrimitive() =
-            if (KotlinBuiltIns.isPrimitiveType(this)) this
+        if (KotlinBuiltIns.isPrimitiveType(this)) this
-            else this.makeNullable()
+        else this.makeNullable()
 
     fun createWriteSelfFunctionDescriptor(thisClass: ClassDescriptor): FunctionDescriptor {
         val jvmStaticClass = thisClass.module.findClassAcrossModuleDependencies(

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/resolve/SearchUtils.kt

@@ -0,0 +1,98 @@
+/*
+ * 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.kotlinx.serialization.compiler.resolve
+
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.annotations.Annotated
+import org.jetbrains.kotlin.descriptors.annotations.Annotations
+import org.jetbrains.kotlin.name.ClassId
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.psi.ValueArgument
+import org.jetbrains.kotlin.resolve.constants.KClassValue
+import org.jetbrains.kotlin.resolve.descriptorUtil.module
+import org.jetbrains.kotlin.resolve.lazy.descriptors.LazyAnnotationDescriptor
+import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.KotlinTypeFactory
+
+internal fun ClassConstructorDescriptor.isSerializationCtor(): Boolean =
+    kind == CallableMemberDescriptor.Kind.SYNTHESIZED && valueParameters.lastOrNull()?.name == SerialEntityNames.dummyParamName
+
+// finds constructor (KSerializer<T0>, KSerializer<T1>...) on a KSerializer<T<T0, T1...>>
+internal fun findSerializerConstructorForTypeArgumentsSerializers(
+    serializerDescriptor: ClassDescriptor,
+    onlyIfSynthetic: Boolean = false
+): ClassConstructorDescriptor? {
+    val serializableImplementationTypeArguments = extractKSerializerArgumentFromImplementation(serializerDescriptor)?.arguments
+        ?: throw AssertionError("Serializer does not implement KSerializer??")
+
+    val typeParamsCount = serializableImplementationTypeArguments.size
+    if (typeParamsCount == 0) return null //don't need it
+    val ctor = serializerDescriptor.constructors.find { ctor ->
+        ctor.valueParameters.size == typeParamsCount && ctor.valueParameters.all { isKSerializer(it.type) }
+    }
+    return if (!onlyIfSynthetic) ctor else ctor?.takeIf { it.kind == CallableMemberDescriptor.Kind.SYNTHESIZED }
+}
+
+inline fun <reified R> Annotations.findAnnotationConstantValue(annotationFqName: FqName, property: String): R? =
+    findAnnotation(annotationFqName)?.let { annotation ->
+        annotation.allValueArguments.entries.singleOrNull { it.key.asString() == property }?.value?.value
+    } as? R
+
+internal fun Annotations.findAnnotationKotlinTypeValue(
+    annotationFqName: FqName,
+    moduleForResolve: ModuleDescriptor,
+    property: String
+): KotlinType? =
+    findAnnotation(annotationFqName)?.let { annotation ->
+        val maybeKClass = annotation.allValueArguments.entries.singleOrNull { it.key.asString() == property }?.value as? KClassValue
+        maybeKClass?.getArgumentType(moduleForResolve)
+    }
+
+internal fun ClassDescriptor.getKSerializerConstructorMarker(): ClassDescriptor =
+    module.findClassAcrossModuleDependencies(ClassId(SerializationPackages.packageFqName, SerialEntityNames.SERIAL_CTOR_MARKER_NAME))!!
+
+internal fun ModuleDescriptor.getClassFromInternalSerializationPackage(classSimpleName: String) =
+    getFromPackage(SerializationPackages.internalPackageFqName, classSimpleName)
+
+internal fun ModuleDescriptor.getClassFromSerializationPackage(classSimpleName: String) =
+    getFromPackage(SerializationPackages.packageFqName, classSimpleName)
+
+private fun ModuleDescriptor.getFromPackage(packageFqName: FqName, classSimpleName: String) = requireNotNull(
+    findClassAcrossModuleDependencies(
+        ClassId(
+            packageFqName,
+            Name.identifier(classSimpleName)
+        )
+    )
+) { "Can't locate class $classSimpleName from package $packageFqName" }
+
+internal fun ClassDescriptor.getClassFromSerializationPackage(classSimpleName: String) =
+    requireNotNull(
+        module.findClassAcrossModuleDependencies(
+            ClassId(
+                SerializationPackages.packageFqName,
+                Name.identifier(classSimpleName)
+            )
+        )
+    ) { "Can't locate class $classSimpleName" }
+
+internal fun ClassDescriptor.getClassFromInternalSerializationPackage(classSimpleName: String) =
+    module.getClassFromInternalSerializationPackage(classSimpleName)
+
+fun ClassDescriptor.toSimpleType(nullable: Boolean = true) =
+    KotlinTypeFactory.simpleType(Annotations.EMPTY, this.typeConstructor, emptyList(), nullable)
+
+internal fun Annotated.annotationsWithArguments(): List<Triple<ClassDescriptor, List<ValueArgument>, List<ValueParameterDescriptor>>> =
+    annotations.asSequence()
+        .filter { it.type.toClassDescriptor?.isSerialInfoAnnotation == true }
+        .filterIsInstance<LazyAnnotationDescriptor>()
+        .mapNotNull { annDesc ->
+            annDesc.type.toClassDescriptor?.let {
+                Triple(it, annDesc.annotationEntry.valueArguments, it.unsubstitutedPrimaryConstructor?.valueParameters.orEmpty())
+            }
+        }
+        .toList()