chore: use jsonc config file for gvm class init config

Signed-off-by: Sam Gammon <sam@elide.dev>

buildSrc/build.gradle.kts

@@ -13,11 +13,14 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+@file:Suppress("UnstableApiUsage")
+
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 
 plugins {
   `kotlin-dsl`
   `jvm-toolchains`
+  embeddedKotlin("plugin.serialization")
 }
 
 // Keep this in sync with the constants in `BuildInfo.kt` (those are not addressable here).
@@ -30,6 +33,9 @@ dependencies {
   implementation(libs.kotlinPlugin) { exclude(module = "kotlin-android-extensions") }
   implementation(libs.shadowPlugin)
 
+  // used to load graalvm configs
+  implementation(libs.kotlinxSerializationJson)
+
   // fix from the Gradle team: makes version catalog symbols available in build scripts
   // see here for more: https://github.com/gradle/gradle/issues/15383
   implementation(files(libs.javaClass.superclass.protectionDomain.codeSource.location))

buildSrc/src/main/kotlin/BuildInfo.kt

@@ -15,12 +15,15 @@
  */
 @file:Suppress("MemberVisibilityCanBePrivate")
 
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.decodeFromStream
 import java.io.File
 import org.gradle.api.Project
 import org.gradle.api.Task
 import org.gradle.api.artifacts.VersionCatalog
 import org.gradle.api.artifacts.VersionCatalogsExtension
 import org.gradle.api.attributes.Category
+import org.gradle.api.file.RegularFile
 import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.TaskProvider
 import org.gradle.api.tasks.testing.Test
@@ -31,6 +34,7 @@ import org.gradle.kotlin.dsl.getByType
 import org.gradle.kotlin.dsl.register
 import org.gradle.kotlin.dsl.support.serviceOf
 import org.gradle.process.CommandLineArgumentProvider
+import java.nio.charset.StandardCharsets
 
 /**
  * JVM bytecode target; this is pinned at a reasonable version, because downstream JVM projects
@@ -178,6 +182,16 @@ open class BuildInfo(private val project: Project) {
     JavaVersionRange.inclusive(jdkTestFloor, jdkTestCeiling)
   }
 
+  /**
+   * Read a configuration file for GraalVM initialization.
+   */
+  fun graalvmConfig(file: RegularFile): GraalVmInitializationConfig =
+    file.asFile.reader(StandardCharsets.UTF_8).use {
+      Json.decodeFromString(it.readText().lineSequence().filter { line ->
+        !line.trim().startsWith("//")  // filter out comments
+      }.joinToString("\n"))
+    }
+
   private fun JavaToolchainSpec.pklJdkToolchain() {
     languageVersion.set(jdkToolchainVersion)
     vendor.set(jdkVendor)

buildSrc/src/main/kotlin/GraalVmInitializationConfig.kt

@@ -0,0 +1,27 @@
+import kotlinx.serialization.Serializable
+
+/**
+ * Models the structure of a simple JSON config file for classes and packages which should be
+ * initialized at build time or run time by the GraalVM Native Image compiler.
+ *
+ * @property initializeAtBuildTime A list of fully qualified class names or package names which
+ *   should be initialized at build time.
+ * @property initializeAtRunTime A list of fully qualified class names or package names which
+ *   should be initialized at run time.
+ */
+@JvmRecord
+@Serializable
+data class GraalVmInitializationConfig(
+  val initializeAtBuildTime: List<String> = emptyList(),
+  val initializeAtRunTime: List<String> = emptyList(),
+) {
+  /**
+   * Return as a serialized list of string arguments that can be supplied to the Native Image
+   * compiler.
+   */
+  val asArgs: List<String> get() =
+    buildList {
+      addAll(initializeAtBuildTime.map { "--initialize-at-build-time=$it" })
+      addAll(initializeAtRunTime.map { "--initialize-at-run-time=$it" })
+    }
+}

pkl-cli/pkl-cli.gradle.kts

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 import org.gradle.kotlin.dsl.support.serviceOf
+import java.nio.file.Path
 
 plugins {
   pklAllProjects
@@ -200,11 +201,16 @@ tasks.check {
   )
 }
 
+val classInitConfig = layout.projectDirectory.file(Path.of("config", "classinit.jsonc").toString())
+
 fun Exec.configureExecutable(
   graalVm: BuildInfo.GraalVm,
   outputFile: Provider<RegularFile>,
   extraArgs: List<String> = listOf(),
 ) {
+  inputs.file(classInitConfig)
+  val classinit = buildInfo.graalvmConfig(classInitConfig)
+
   inputs
     .files(sourceSets.main.map { it.output })
     .withPropertyName("mainSourceSets")
@@ -235,6 +241,10 @@ fun Exec.configureExecutable(
         // currently gives a deprecation warning, but we've been told
         // that the "initialize everything at build time" *CLI* option is likely here to stay
         add("--initialize-at-build-time=")
+        if (JavaVersion.current() == JavaVersion.VERSION_21)
+          add("--strict-image-heap")
+        // load, compute, and configure class initialization
+        addAll(classinit.asArgs)
         // needed for messagepack-java (see https://github.com/msgpack/msgpack-java/issues/600)
         add("--initialize-at-run-time=org.msgpack.core.buffer.DirectBufferAccess")
         add("--no-fallback")