Publish executables for pkldoc, pkl-codegen-java, pkl-codegen-kotlin (#1023)

This adds logic to build and publish the other executables related to Pkl.

These are:

* pkl-doc
* pkl-codegen-kotlin
* pkl-codegen-java

pkl-codegen-kotlin and pkl-codegen-java are published as executable JARs, whereas pkldoc is published both as an executable JAR, and also native executables (matching the set of os/arch supported by Pkl).

The reason this only publishes executable JARs for pkl-codegen-kotlin and pkl-codegen-java is because we expect that the Java requirement is not a problem for these users, and that the native executable provides negligible added value.

As part of this, the following changes are made:

* Introduce `pklJavaExecutable` plugin, which sets up building and publishing of executable JAR.
* Introduce `pklNativeExecutable` plugin, which sets up building and publishing of native executables.
* Introduce `NativeImageBuild` Gradle task, which knows how to build native-image executables.
* Introduce `ExecutableSpec` extension, for projects that publish executables to configure how those executables should be published.
* `./griddles buildNative`, by default, will only build the executable of the host OS/Arch, and will no longer cross-build.
* The target arch of `./gradlew buildNative` can be changed using `-Dpkl.targetArch=<aarch64|amd64>`.
* On linux/amd64 only, with `./gradlew buildNative`, a statically linked executable can be built using `-Dpkl.musl=true`
* Make `javaExecutable` a dependency of `assemble`
* Make `testStartJavaExecutable` a dependency of `check`
* Change name `pklNativeBuild` to `pklNativeLifecycle` to better match the plugin's purpose
* Remove Truffle SVM classes from main source set (don't publish these classes as part of the pkl-cli JAR)
* Change CircleCI definition to publish new executables
* Change CircleCI definition to call `buildNative` instead of individual task names

buildSrc/src/main/kotlin/pklJavaExecutable.gradle.kts

@@ -0,0 +1,132 @@
+/*
+ * Copyright © 2025 Apple Inc. and the Pkl project authors. All rights reserved.
+ *
+ * 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
+ *
+ *     https://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.
+ */
+import kotlin.io.path.createDirectories
+import kotlin.io.path.writeText
+import org.gradle.kotlin.dsl.support.serviceOf
+
+plugins {
+  id("pklJavaLibrary")
+  id("pklPublishLibrary")
+  id("com.github.johnrengelman.shadow")
+}
+
+val executableSpec = project.extensions.create("executable", ExecutableSpec::class.java)
+val buildInfo = project.extensions.getByType<BuildInfo>()
+
+val javaExecutable by
+  tasks.registering(ExecutableJar::class) {
+    group = "build"
+    dependsOn(tasks.jar)
+    inJar = tasks.shadowJar.flatMap { it.archiveFile }
+    val effectiveJavaName =
+      executableSpec.javaName.map { name -> if (buildInfo.os.isWindows) "$name.bat" else name }
+    outJar = layout.buildDirectory.dir("executable").flatMap { it.file(effectiveJavaName) }
+
+    // uncomment for debugging
+    // jvmArgs.addAll("-ea", "-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=5005")
+  }
+
+fun Task.setupTestStartJavaExecutable(launcher: Provider<JavaLauncher>? = null) {
+  group = "verification"
+  dependsOn(javaExecutable)
+
+  // dummy output to satisfy up-to-date check
+  val outputFile = layout.buildDirectory.file("testStartJavaExecutable/$name")
+  outputs.file(outputFile)
+
+  val execOutput =
+    providers.exec {
+      val executablePath = javaExecutable.get().outputs.files.singleFile
+      if (launcher?.isPresent == true) {
+        commandLine(
+          launcher.get().executablePath.asFile.absolutePath,
+          "-jar",
+          executablePath.absolutePath,
+          "--version",
+        )
+      } else {
+        commandLine(executablePath.absolutePath, "--version")
+      }
+    }
+
+  doLast {
+    val outputText = execOutput.standardOutput.asText.get()
+    if (!outputText.contains(buildInfo.pklVersionNonUnique)) {
+      throw GradleException(
+        "Expected version output to contain current version (${buildInfo.pklVersionNonUnique}), but got '$outputText'"
+      )
+    }
+    outputFile.get().asFile.toPath().apply {
+      try {
+        parent.createDirectories()
+      } catch (ignored: java.nio.file.FileAlreadyExistsException) {}
+      writeText("OK")
+    }
+  }
+}
+
+val testStartJavaExecutable by tasks.registering { setupTestStartJavaExecutable() }
+
+// Setup `testStartJavaExecutable` tasks for multi-JDK testing.
+val testStartJavaExecutableOnOtherJdks =
+  buildInfo.jdkTestRange.map { jdkTarget ->
+    tasks.register("testStartJavaExecutableJdk${jdkTarget.asInt()}") {
+      val toolChainService: JavaToolchainService = serviceOf()
+      val launcher = toolChainService.launcherFor { languageVersion = jdkTarget }
+      setupTestStartJavaExecutable(launcher)
+    }
+  }
+
+tasks.assemble { dependsOn(javaExecutable) }
+
+tasks.check {
+  dependsOn(testStartJavaExecutable)
+  if (buildInfo.multiJdkTesting) {
+    dependsOn(testStartJavaExecutableOnOtherJdks)
+  }
+}
+
+publishing {
+  publications {
+    // need to put in `afterEvaluate` because `artifactId` cannot be set lazily.
+    project.afterEvaluate {
+      register<MavenPublication>("javaExecutable") {
+        artifactId = executableSpec.javaPublicationName.get()
+
+        artifact(javaExecutable.map { it.outputs.files.singleFile }) {
+          classifier = null
+          extension = "jar"
+          builtBy(javaExecutable)
+        }
+
+        pom {
+          url = executableSpec.website
+          description =
+            executableSpec.documentationName.map { name ->
+              """
+            $name executable for Java.
+            Can be executed directly, or with `java -jar <path/to/jpkl>`.
+            Requires Java 17 or higher.
+            """
+                .trimIndent()
+            }
+        }
+      }
+    }
+  }
+}
+
+signing { project.afterEvaluate { sign(publishing.publications["javaExecutable"]) } }