Support new 'typeParametersSerializers' function

from GeneratedSerializer

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

@@ -1,17 +1,6 @@
 /*
- * Copyright 2010-2017 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 2010-2020 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.kotlinx.serialization.compiler.backend.common
@@ -21,7 +10,6 @@ import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.BindingContext
-import org.jetbrains.kotlin.resolve.scopes.getDescriptorsFiltered
 import org.jetbrains.kotlinx.serialization.compiler.resolve.*
 
 abstract class SerializerCodegen(
@@ -45,7 +33,7 @@ abstract class SerializerCodegen(
             generateSerialDesc()
         val save = generateSaveIfNeeded()
         val load = generateLoadIfNeeded()
-        generateDescriptorGetterIfNeeded()
+        generateMembersFromGeneratedSerializer()
         if (!prop && (save || load))
             generateSerialDesc()
         if (serializableDescriptor.declaredTypeParameters.isNotEmpty()) {
@@ -55,15 +43,19 @@ abstract class SerializerCodegen(
         }
     }
 
-    private fun generateDescriptorGetterIfNeeded(): Boolean {
-        val function = getMemberToGenerate(
-            serializerDescriptor, SerialEntityNames.GENERATED_DESCRIPTOR_GETTER.identifier,
-            { true }, { true }
-        ) ?: return false
-        generateChildSerializersGetter(function)
-        return true
+    private fun generateMembersFromGeneratedSerializer() {
+        getMemberToGenerate(
+            serializerDescriptor, SerialEntityNames.CHILD_SERIALIZERS_GETTER.identifier,
+            { true }, { it.isEmpty() }
+        )?.let { generateChildSerializersGetter(it) }
+        getMemberToGenerate(
+            serializerDescriptor, SerialEntityNames.TYPE_PARAMS_SERIALIZERS_GETTER.identifier,
+            { true }, { it.isEmpty() }
+        )?.takeIf { it.kind != CallableMemberDescriptor.Kind.FAKE_OVERRIDE }?.let { generateTypeParamsSerializersGetter(it) }
     }
 
+    protected abstract fun generateTypeParamsSerializersGetter(function: FunctionDescriptor)
+
     protected abstract fun generateChildSerializersGetter(function: FunctionDescriptor)
 
     protected val generatedSerialDescPropertyDescriptor = getPropertyToGenerate(

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

@@ -194,6 +194,18 @@ open class SerializerIrGenerator(val irClass: IrClass, final override val compil
         +irReturn(array)
     }
 
+    override fun generateTypeParamsSerializersGetter(function: FunctionDescriptor) = irClass.contributeFunction(function) { irFun ->
+        val typeParams = serializableDescriptor.declaredTypeParameters.mapIndexed { idx, _ ->
+            irGetField(
+                irGet(irFun.dispatchReceiverParameter!!),
+                compilerContext.symbolTable.referenceField(localSerializersFieldsDescriptors[idx]).owner
+            )
+        }
+        val kSerType = ((irFun.returnType as IrSimpleType).arguments.first() as IrTypeProjection).type
+        val array = createArrayOfExpression(kSerType, typeParams)
+        +irReturn(array)
+    }
+
     override fun generateSerializableClassProperty(property: PropertyDescriptor) {
         /* Already implemented in .generateSerialClassDesc ? */
     }

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

@@ -111,6 +111,13 @@ open class SerializerJsTranslator(
         +JsReturn(JsArrayLiteral(allSerializers))
     }
 
+    override fun generateTypeParamsSerializersGetter(function: FunctionDescriptor) = generateFunction(function) { _, _ ->
+        val typeParams = serializableDescriptor.declaredTypeParameters.mapIndexed { idx, _ ->
+            JsNameRef(context.scope().declareName("$typeArgPrefix$idx"), JsThisRef())
+        }
+        +JsReturn(JsArrayLiteral(typeParams))
+    }
+
     override fun generateSerializableClassProperty(property: PropertyDescriptor) {
         val propDesc = generatedSerialDescPropertyDescriptor ?: return
         val propTranslator = DefaultPropertyTranslator(

plugins/kotlin-serialization/kotlin-serialization-compiler/src/org/jetbrains/kotlinx/serialization/compiler/backend/jvm/SerializerCodegenImpl.kt

@@ -185,6 +185,11 @@ open class SerializerCodegenImpl(
         }
     }
 
+    override fun generateTypeParamsSerializersGetter(function: FunctionDescriptor) = codegen.generateMethod(function) { _, _ ->
+        genArrayOfTypeParametersSerializers()
+        areturn(kSerializerArrayType)
+    }
+
     override fun generateChildSerializersGetter(function: FunctionDescriptor) {
         codegen.generateMethod(function) { _, _ ->
             val size = serializableProperties.size

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

@@ -16,8 +16,6 @@ import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.platform.js.isJs
-import org.jetbrains.kotlin.platform.jvm.isJvm
 import org.jetbrains.kotlin.platform.konan.isNative
 import org.jetbrains.kotlin.psi.synthetics.SyntheticClassOrObjectDescriptor
 import org.jetbrains.kotlin.resolve.BindingContext
@@ -213,11 +211,16 @@ object KSerializerDescriptorResolver {
                 shouldAddSerializerFunction { classDescriptor.checkSaveMethodParameters(it.valueParameters) }
         val isLoad = name == SerialEntityNames.LOAD_NAME &&
                 shouldAddSerializerFunction { classDescriptor.checkLoadMethodParameters(it.valueParameters) }
-        val isDescriptorGetter = name == SerialEntityNames.GENERATED_DESCRIPTOR_GETTER &&
+        val isDescriptorGetter = name == SerialEntityNames.CHILD_SERIALIZERS_GETTER &&
                 thisDescriptor.typeConstructor.supertypes.any(::isGeneratedKSerializer) &&
                 shouldAddSerializerFunction { true /* TODO? */ }
 
-        if (isSave || isLoad || isDescriptorGetter) {
+        val isTypeParamsSerializersGetter = name == SerialEntityNames.TYPE_PARAMS_SERIALIZERS_GETTER &&
+                thisDescriptor.typeConstructor.supertypes.any(::isGeneratedKSerializer) &&
+                classDescriptor.declaredTypeParameters.isNotEmpty() &&
+                shouldAddSerializerFunction { true /* TODO? */ }
+
+        if (isSave || isLoad || isDescriptorGetter || isTypeParamsSerializersGetter) {
             result.add(doCreateSerializerFunction(thisDescriptor, name))
         }
     }

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

@@ -1,3 +1,8 @@
+/*
+ * Copyright 2010-2020 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.kotlinx.serialization.compiler.resolve
 
 import org.jetbrains.kotlin.name.FqName
@@ -66,7 +71,8 @@ object SerialEntityNames {
     val SERIAL_DESC_FIELD_NAME = Name.identifier(SERIAL_DESC_FIELD)
     val SAVE_NAME = Name.identifier(SAVE)
     val LOAD_NAME = Name.identifier(LOAD)
-    val GENERATED_DESCRIPTOR_GETTER = Name.identifier("childSerializers")
+    val CHILD_SERIALIZERS_GETTER = Name.identifier("childSerializers")
+    val TYPE_PARAMS_SERIALIZERS_GETTER = Name.identifier("typeParametersSerializers")
     val WRITE_SELF_NAME = Name.identifier("write\$Self")
     val SERIALIZER_PROVIDER_NAME = Name.identifier("serializer")