From 51be4e7f056867469a4966e1fe63f0bcdc78ba6e Mon Sep 17 00:00:00 2001
From: Vladimir Krivosheev <vladimir.krivosheev@jetbrains.com>
Date: Sun, 9 Jan 2022 10:25:24 +0100
Subject: [PATCH] =?UTF-8?q?don't=20use=20official=20`::kotlin.get().serial?=
 =?UTF-8?q?izer()`=20API=20=E2=80=94=20avoid=20kotlin=20refection=20wrappe?=
 =?UTF-8?q?r=20creation?=
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https://github.com/Kotlin/kotlinx.serialization/issues/1819

GitOrigin-RevId: 9a1bce7a70b6c68c9c6267baa53ac0509b9ff294
---
 .../src/xml/KotlinxSerializationBinding.kt    | 19 ++++++++++++++++++-
 .../src/xml/xmlSerializer.kt                  |  6 +-----
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/platform/object-serializer/src/xml/KotlinxSerializationBinding.kt b/platform/object-serializer/src/xml/KotlinxSerializationBinding.kt
index 0ae0856e43fce..d810f5e49e182 100644
--- a/platform/object-serializer/src/xml/KotlinxSerializationBinding.kt
+++ b/platform/object-serializer/src/xml/KotlinxSerializationBinding.kt
@@ -9,6 +9,8 @@ import kotlinx.serialization.KSerializer
 import kotlinx.serialization.json.Json
 import org.jdom.CDATA
 import org.jdom.Element
+import java.lang.invoke.MethodHandles
+import java.lang.invoke.MethodType
 
 @OptIn(ExperimentalSerializationApi::class)
 private val json = Json {
@@ -17,7 +19,22 @@ private val json = Json {
   ignoreUnknownKeys = true
 }
 
-internal class KotlinxSerializationBinding(private val serializer: KSerializer<Any>) : NotNullDeserializeBinding() {
+private val lookup = MethodHandles.lookup()
+private val kotlinMethodType = MethodType.methodType(KSerializer::class.java)
+
+internal class KotlinxSerializationBinding(aClass: Class<*>) : NotNullDeserializeBinding() {
+  private val serializer: KSerializer<Any>
+
+  init {
+    // don't use official `::kotlin.get().serializer()` API — avoid kotlin refection wrapper creation
+    // findStaticGetter cannot be used because type of Companion not used
+    val field = aClass.getDeclaredField("Companion")
+    field.isAccessible = true
+    val companion = lookup.unreflectGetter(field).invoke()
+    @Suppress("UNCHECKED_CAST")
+    serializer = lookup.findVirtual(companion.javaClass, "serializer", kotlinMethodType).invoke(companion) as KSerializer<Any>
+  }
+
   override fun serialize(o: Any, context: Any?, filter: SerializationFilter?): Any {
     val element = Element("state")
     element.addContent(CDATA(json.encodeToString(serializer, o)))
diff --git a/platform/object-serializer/src/xml/xmlSerializer.kt b/platform/object-serializer/src/xml/xmlSerializer.kt
index 6852c8edcfc1f..fa7e99641db7b 100644
--- a/platform/object-serializer/src/xml/xmlSerializer.kt
+++ b/platform/object-serializer/src/xml/xmlSerializer.kt
@@ -10,9 +10,7 @@ import com.intellij.serialization.xml.KotlinAwareBeanBinding
 import com.intellij.serialization.xml.KotlinxSerializationBinding
 import com.intellij.util.io.URLUtil
 import com.intellij.util.xmlb.*
-import kotlinx.serialization.InternalSerializationApi
 import kotlinx.serialization.Serializable
-import kotlinx.serialization.serializer
 import org.jdom.Element
 import org.jdom.JDOMException
 import org.jetbrains.annotations.TestOnly
@@ -172,14 +170,12 @@ private abstract class OldBindingProducer<ROOT_BINDING> {
 }
 
 private class MyXmlSerializer : XmlSerializerImpl.XmlSerializerBase() {
-  @OptIn(InternalSerializationApi::class)
   val bindingProducer = object : OldBindingProducer<Binding>() {
     override fun createRootBinding(aClass: Class<*>, type: Type, cacheKey: Type, map: MutableMap<Type, Binding>): Binding {
       var binding = createClassBinding(aClass, null, type)
       if (binding == null) {
         if (aClass.isAnnotationPresent(Serializable::class.java)) {
-          @Suppress("UNCHECKED_CAST")
-          binding = KotlinxSerializationBinding((aClass as Class<Any>)::kotlin.get().serializer())
+          binding = KotlinxSerializationBinding(aClass)
         }
         else {
           binding = KotlinAwareBeanBinding(aClass)