Be more compatible with K2

The compiler plugins are always loaded unconditioanlly regardless of K1 or K2 and causes FirKotlinToJvmBytecodeCompiler to throw. Because there seems no way to load compiler plugins conditionally on language version, we declare the KSP compiler plugin to be K2 compatible while doing nothing if K2 is detected. Tested locally with a new enough Kotlin compiler.
google · Oct 23, 2023 · 36f7357 · 36f7357
1 parent a136cfe
commit 36f7357
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Showing 2 changed files with 20 additions and 6 deletions.
diff --git a/compiler-plugin/src/main/kotlin/com/google/devtools/ksp/KotlinSymbolProcessingPlugin.kt b/compiler-plugin/src/main/kotlin/com/google/devtools/ksp/KotlinSymbolProcessingPlugin.kt
@@ -33,6 +33,7 @@ import org.jetbrains.kotlin.config.CommonConfigurationKeys
 import org.jetbrains.kotlin.config.CompilerConfiguration
 import org.jetbrains.kotlin.config.CompilerConfigurationKey
 import org.jetbrains.kotlin.config.KotlinCompilerVersion
+import org.jetbrains.kotlin.config.LanguageVersion
 import org.jetbrains.kotlin.config.languageVersionSettings
 import org.jetbrains.kotlin.resolve.extensions.AnalysisHandlerExtension
 
@@ -64,6 +65,10 @@ class KotlinSymbolProcessingCommandLineProcessor : CommandLineProcessor {
 @ExperimentalCompilerApi
 class KotlinSymbolProcessingComponentRegistrar : ComponentRegistrar {
     override fun registerProjectComponents(project: MockProject, configuration: CompilerConfiguration) {
+        // KSP 1.x don't and will not support K2. Do not register if language version >= 2.
+        if (configuration.languageVersionSettings.languageVersion >= LanguageVersion.KOTLIN_2_0)
+            return
+
         val contentRoots = configuration[CLIConfigurationKeys.CONTENT_ROOTS] ?: emptyList()
         val options = configuration[KSP_OPTIONS]?.apply {
             javaSourceRoots.addAll(contentRoots.filterIsInstance<JavaSourceRoot>().map { it.file })
@@ -91,4 +96,8 @@ class KotlinSymbolProcessingComponentRegistrar : ComponentRegistrar {
             )
         }
     }
+
+    // FirKotlinToJvmBytecodeCompiler throws an error when it sees an incompatible plugin.
+    override val supportsK2: Boolean
+        get() = true
 }
diff --git a/gradle-plugin/src/main/kotlin/com/google/devtools/ksp/gradle/KspSubplugin.kt b/gradle-plugin/src/main/kotlin/com/google/devtools/ksp/gradle/KspSubplugin.kt
@@ -36,7 +36,6 @@ import org.gradle.tooling.provider.model.ToolingModelBuilderRegistry
 import org.gradle.util.GradleVersion
 import org.jetbrains.kotlin.buildtools.api.SourcesChanges
 import org.jetbrains.kotlin.config.ApiVersion
-import org.jetbrains.kotlin.config.LanguageVersion.Companion.LATEST_STABLE
 import org.jetbrains.kotlin.gradle.dsl.KotlinVersion
 import org.jetbrains.kotlin.gradle.dsl.kotlinExtension
 import org.jetbrains.kotlin.gradle.internal.kapt.incremental.CLASS_STRUCTURE_ARTIFACT_TYPE
@@ -75,7 +74,6 @@ class KspGradleSubplugin @Inject internal constructor(private val registry: Tool
         const val KSP_GROUP_ID = "com.google.devtools.ksp"
         const val KSP_PLUGIN_CLASSPATH_CONFIGURATION_NAME = "kspPluginClasspath"
         const val KSP_PLUGIN_CLASSPATH_CONFIGURATION_NAME_NON_EMBEDDABLE = "kspPluginClasspathNonEmbeddable"
-        val LANGUAGE_VERSION = KotlinVersion.fromVersion(LATEST_STABLE.toString())
 
         @JvmStatic
         fun getKspOutputDir(project: Project, sourceSetName: String, target: String) =
@@ -408,11 +406,18 @@ class KspGradleSubplugin @Inject internal constructor(private val registry: Tool
 
         fun configureLanguageVersion(kspTask: KotlinCompilationTask<*>) {
             kspTask.compilerOptions.useK2.value(false)
-            kotlinCompilation.compilerOptions.options.languageVersion.orNull?.let { version ->
-                if (version >= KotlinVersion.KOTLIN_2_0) {
-                    kspTask.compilerOptions.languageVersion.value(LANGUAGE_VERSION)
+            val languageVersion = kotlinCompilation.compilerOptions.options.languageVersion
+            kspTask.compilerOptions.languageVersion.value(
+                project.provider {
+                    languageVersion.orNull?.let { version ->
+                        if (version >= KotlinVersion.KOTLIN_2_0) {
+                            KotlinVersion.KOTLIN_1_9
+                        } else {
+                            version
+                        }
+                    }
                 }
-            }
+            )
         }
 
         val isIncremental = project.findProperty("ksp.incremental")?.toString()?.toBoolean() ?: true