Move GraalVM JDK to shared Gradle directory and simplify helper

buildSrc/gradlew

@@ -116,7 +116,7 @@ CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
 
 # GRADLE JVM WRAPPER START MARKER
-BUILD_DIR="$APP_HOME/gradle/jdk"
+BUILD_DIR="$HOME/.gradle/jdks/graalvm-21.0.2"
 JVM_ARCH=$(uname -m)
 JVM_TEMP_FILE=$BUILD_DIR/gradle-jvm-temp.tar.gz
 if [ "$darwin" = "true" ]; then

buildSrc/gradlew.bat

@@ -39,7 +39,7 @@ set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
 @rem GRADLE JVM WRAPPER START MARKER
 
 setlocal
-set BUILD_DIR=%APP_HOME%\gradle\jdk
+set BUILD_DIR=%USERPROFILE%\.gradle\jdks\graalvm-21.0.2
 set JVM_TARGET_DIR=%BUILD_DIR%\graalvm-community-jdk-21.0.2_windows-x64_bin-8bbfc2\
 
 set JVM_URL=https://github.com/graalvm/graalvm-ce-builds/releases/download/jdk-21.0.2/graalvm-community-jdk-21.0.2_windows-x64_bin.zip

buildSrc/src/main/kotlin/org/kson/GraalVmHelper.kt

@@ -1,37 +1,31 @@
 package org.kson
 
 import org.gradle.api.GradleException
-import org.gradle.api.Project
 import java.io.File
 
 object GraalVmHelper {
-    val os = System.getProperty("os.name").lowercase()
+    private val os = System.getProperty("os.name").lowercase()
 
     /**
-    * Locates the GraalVM JDK installation directory within the gradle/jdk folder.
-    * The JDK is automatically downloaded by the Gradle wrapper based on jdk.properties.
-    * Handles platform-specific directory structures (e.g., macOS's Contents/Home subdirectory).
+    * Gets the GraalVM home directory. Since Gradle is already running with the JDK from
+    * jdk.properties (via the jvm.wrapper plugin), we just use Gradle's own JAVA_HOME.
     * @return The GraalVM home directory
     * @throws GradleException if GraalVM JDK is not found
     */
-    fun getGraalVMHome(rootProject: Project): File {
-        val graalvmDir = File("${rootProject.projectDir}/gradle/jdk")
+    fun getGraalVMHome(): File {
+        val javaHome = File(System.getProperty("java.home"))
 
-        val graalvmTopLevelDir = graalvmDir.listFiles()?.find {
-            it.isDirectory && it.name.contains("graalvm")
-        } ?: throw GradleException("GraalVM JDK not found in $graalvmDir (no top-level dir present). Run './gradlew' to download it.")
-
-        // In MacOS the graalvm directory is unpacked inside a graalvm directory, try to find it
-        val graalvmUnpackDir = graalvmTopLevelDir.listFiles()?.find {
-            it.isDirectory && it.name.contains("graalvm")
-        } ?: graalvmTopLevelDir  // Fall back to top-level if no nested dir found
-
-        // Special handling for macOS: use Contents/Home subdirectory if it exists
-        return if ((os.contains("mac") || os.contains("darwin")) && File("$graalvmUnpackDir/Contents/Home").exists()) {
-            File("$graalvmUnpackDir/Contents/Home")
-        } else {
-            graalvmUnpackDir
+        // Verify it's actually GraalVM
+        val nativeImageExe = File(javaHome, "bin/native-image${getNativeImageExtension()}")
+        if (!nativeImageExe.exists()) {
+            throw GradleException(
+                "native-image not found at $nativeImageExe. " +
+                "The JDK at $javaHome does not appear to be GraalVM. " +
+                "Please ensure jdk.properties points to a GraalVM distribution."
+            )
         }
+
+        return javaHome
     }
 
     /**

gradlew

@@ -116,7 +116,7 @@ CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
 
 # GRADLE JVM WRAPPER START MARKER
-BUILD_DIR="$APP_HOME/gradle/jdk"
+BUILD_DIR="$HOME/.gradle/jdks/graalvm-21.0.2"
 JVM_ARCH=$(uname -m)
 JVM_TEMP_FILE=$BUILD_DIR/gradle-jvm-temp.tar.gz
 if [ "$darwin" = "true" ]; then

gradlew.bat

@@ -39,7 +39,7 @@ set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
 @rem GRADLE JVM WRAPPER START MARKER
 
 setlocal
-set BUILD_DIR=%APP_HOME%\gradle\jdk
+set BUILD_DIR=%USERPROFILE%\.gradle\jdks\graalvm-21.0.2
 set JVM_TARGET_DIR=%BUILD_DIR%\graalvm-community-jdk-21.0.2_windows-x64_bin-8bbfc2\
 
 set JVM_URL=https://github.com/graalvm/graalvm-ce-builds/releases/download/jdk-21.0.2/graalvm-community-jdk-21.0.2_windows-x64_bin.zip

jdk.properties

@@ -19,8 +19,8 @@ JDK_VERSION=21.0.2
 #
 # IF THESE URLs CHANGE: `./gradlew wrapper` must be run after any edits for them to take effect,
 #   and `./gradlew check` should also be run to ensure the new JDK is loaded and verified
-unixJvmInstallDir=$APP_HOME/gradle/jdk
-winJvmInstallDir=%APP_HOME%\\gradle\\jdk
+unixJvmInstallDir=$HOME/.gradle/jdks/graalvm-21.0.2
+winJvmInstallDir=%USERPROFILE%\\.gradle\\jdks\\graalvm-21.0.2
 macAarch64JvmUrl=https://github.com/graalvm/graalvm-ce-builds/releases/download/jdk-21.0.2/graalvm-community-jdk-21.0.2_macos-aarch64_bin.tar.gz
 macX64JvmUrl=https://github.com/graalvm/graalvm-ce-builds/releases/download/jdk-21.0.2/graalvm-community-jdk-21.0.2_macos-x64_bin.tar.gz
 linuxAarch64JvmUrl = https://github.com/graalvm/graalvm-ce-builds/releases/download/jdk-21.0.2/graalvm-community-jdk-21.0.2_linux-aarch64_bin.tar.gz

kson-lib/build.gradle.kts

@@ -248,7 +248,7 @@ tasks.register<PixiExecTask>("buildWithGraalVmNativeImage") {
 
     // Configure the command at configuration time using providers
     command.set(provider {
-        val graalHome = GraalVmHelper.getGraalVMHome(rootProject)
+        val graalHome = GraalVmHelper.getGraalVMHome()
 
         val nativeImageExe = file("${graalHome}/bin/native-image${GraalVmHelper.getNativeImageExtension()}")
         if (!nativeImageExe.exists()) {

tooling/cli/build.gradle.kts

@@ -61,7 +61,7 @@ val buildNativeImage by tasks.registering(PixiExecTask::class) {
 
     // Configure the command at configuration time using providers
     command.set(provider {
-        val graalHome = GraalVmHelper.getGraalVMHome(rootProject)
+        val graalHome = GraalVmHelper.getGraalVMHome()
 
         val nativeImageExe = file("${graalHome}/bin/native-image${GraalVmHelper.getNativeImageExtension()}")
         if (!nativeImageExe.exists()) {