[K2] Support legacy serialization for custom function type extensions.

For Compose libraries, it is important that libraries built with
K2 in version 2.0 can be read and used by a version 1.9 K1
compiler. That is not possible if custom function types are
in the metadata.

^KT-58456 Fixed

plugins/fir-plugin-prototype/build.gradle.kts

@@ -22,6 +22,7 @@ dependencies {
     testApi(projectTests(":compiler:tests-common-new"))
     testApi(projectTests(":compiler:test-infrastructure"))
     testApi(projectTests(":compiler:test-infrastructure-utils"))
+    testApi(projectTests(":compiler:fir:analysis-tests"))
     testApi(project(":compiler:fir:checkers"))
     testApi(project(":compiler:fir:checkers:checkers.jvm"))
     testApi(project(":compiler:fir:checkers:checkers.js"))

plugins/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/types/ComposableLikeFunctionTypeKindExtension.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.fir.plugin.types
 
 import org.jetbrains.kotlin.builtins.functions.FunctionTypeKind
+import org.jetbrains.kotlin.config.LanguageVersion
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.extensions.FirFunctionTypeKindExtension
 import org.jetbrains.kotlin.fir.plugin.fqn
@@ -31,6 +32,9 @@ object ComposableFunction : FunctionTypeKind(
     override val prefixForTypeRender: String
         get() = "@MyComposable"
 
+    override val serializeAsFunctionWithAnnotationUntil: String
+        get() = LanguageVersion.KOTLIN_2_1.versionString
+
     override fun reflectKind(): FunctionTypeKind = KComposableFunction
 }
 
@@ -40,5 +44,8 @@ object KComposableFunction : FunctionTypeKind(
     MY_COMPOSABLE_ANNOTATION_CLASS_ID,
     isReflectType = true
 ) {
+    override val serializeAsFunctionWithAnnotationUntil: String
+        get() = LanguageVersion.KOTLIN_2_1.versionString
+
     override fun nonReflectKind(): FunctionTypeKind = ComposableFunction
 }

plugins/fir-plugin-prototype/testData/firLoadK2Compiled/simple-lang-ver-2.1.fir.k2.txt

@@ -0,0 +1 @@
+public final fun runComposable(block: R|@R|org/jetbrains/kotlin/fir/plugin/MyComposable|()  some/MyComposableFunction0<kotlin/Unit>|): R|kotlin/Unit|

plugins/fir-plugin-prototype/testData/firLoadK2Compiled/simple-lang-ver-2.1.kt

@@ -0,0 +1,7 @@
+// API_VERSION: 2.0
+// LANGUAGE_VERSION: 2.1
+package test
+
+import org.jetbrains.kotlin.fir.plugin.MyComposable
+
+fun runComposable(block: @MyComposable () -> Unit) {}

plugins/fir-plugin-prototype/testData/firLoadK2Compiled/simple.fir.k2.txt

@@ -0,0 +1 @@
+public final fun runComposable(block: R|@R|org/jetbrains/kotlin/fir/plugin/MyComposable|()  () -> kotlin/Unit|): R|kotlin/Unit|

plugins/fir-plugin-prototype/testData/firLoadK2Compiled/simple.kt

@@ -0,0 +1,8 @@
+// API_VERSION: 2.0
+// LANGUAGE_VERSION: 2.0
+package test
+
+import org.jetbrains.kotlin.fir.plugin.MyComposable
+
+fun runComposable(block: @MyComposable () -> Unit) {}
+

plugins/fir-plugin-prototype/tests-gen/org/jetbrains/kotlin/fir/plugin/runners/FirLoadK2CompiledKotlinWithPluginTestGenerated.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2010-2023 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.fir.plugin.runners;
+
+import com.intellij.testFramework.TestDataPath;
+import org.jetbrains.kotlin.test.util.KtTestUtil;
+import org.jetbrains.kotlin.test.TargetBackend;
+import org.jetbrains.kotlin.test.TestMetadata;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+import java.io.File;
+import java.util.regex.Pattern;
+
+/** This class is generated by {@link org.jetbrains.kotlin.generators.tests.GenerateTestsKt}. DO NOT MODIFY MANUALLY */
+@SuppressWarnings("all")
+@TestMetadata("plugins/fir-plugin-prototype/testData/firLoadK2Compiled")
+@TestDataPath("$PROJECT_ROOT")
+public class FirLoadK2CompiledKotlinWithPluginTestGenerated extends AbstractFirLoadK2CompiledKotlinWithPluginTest {
+    @Test
+    public void testAllFilesPresentInFirLoadK2Compiled() throws Exception {
+        KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("plugins/fir-plugin-prototype/testData/firLoadK2Compiled"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+    }
+
+    @Test
+    @TestMetadata("simple.kt")
+    public void testSimple() throws Exception {
+        runTest("plugins/fir-plugin-prototype/testData/firLoadK2Compiled/simple.kt");
+    }
+
+    @Test
+    @TestMetadata("simple-lang-ver-2.1.kt")
+    public void testSimple_lang_ver_2_1() throws Exception {
+        runTest("plugins/fir-plugin-prototype/testData/firLoadK2Compiled/simple-lang-ver-2.1.kt");
+    }
+}

plugins/fir-plugin-prototype/tests/org/jetbrains/kotlin/fir/plugin/runners/PluginPrototypeTests.kt

@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.fir.plugin.services.PluginAnnotationsProvider
 import org.jetbrains.kotlin.test.builders.TestConfigurationBuilder
 import org.jetbrains.kotlin.test.directives.FirDiagnosticsDirectives.ENABLE_PLUGIN_PHASES
 import org.jetbrains.kotlin.test.directives.FirDiagnosticsDirectives.FIR_DUMP
+import org.jetbrains.kotlin.test.runners.AbstractFirLoadK2CompiledKotlin
 import org.jetbrains.kotlin.test.runners.AbstractFirPsiDiagnosticTest
 import org.jetbrains.kotlin.test.runners.codegen.AbstractFirLightTreeBlackBoxCodegenTest
 import org.jetbrains.kotlin.test.runners.enableLazyResolvePhaseChecking
@@ -28,6 +29,13 @@ abstract class AbstractFirPsiPluginDiagnosticTest : AbstractFirPsiDiagnosticTest
     }
 }
 
+open class AbstractFirLoadK2CompiledKotlinWithPluginTest : AbstractFirLoadK2CompiledKotlin() {
+    override fun configure(builder: TestConfigurationBuilder) {
+        super.configure(builder)
+        builder.commonFirWithPluginFrontendConfiguration()
+    }
+}
+
 fun TestConfigurationBuilder.commonFirWithPluginFrontendConfiguration() {
     enableLazyResolvePhaseChecking()