added documentation of NativeImage plugin

graalvm/REAMDE.md

@@ -0,0 +1,132 @@
+## Overview
+This project contains 2 Gradle plugin:
+- NativeImage allows you to create a native executable file from a Gradle project using GraalVM's `native-image` tool
+- Jlink allows you to create a native distribution of a Gradle project using GraalVM `jlink` tool
+
+### Native Image plugin
+
+Declare the plugin in your build's `settings.gradle` like this
+```groovy
+
+pluginManagement {
+    repositories {
+        maven {
+            url = 'https://woggioni.net/mvn/'
+        }
+    }
+
+    plugins {
+        id "net.woggioni.gradle.graalvm.native-image" version "2023.10.23"
+    }
+}
+```
+
+Then add it to a project's `build.gradle`
+
+```groovy
+plugins {
+    id 'net.woggioni.gradle.graalvm.native-image'
+}
+
+configureNativeImage {
+    args = [ 'your', 'command', 'line', 'arguments']
+}
+
+application {
+    mainClass = 'your.main.Class'
+}
+```
+Mind that if your project also uses the built-in Gradle `application` plugin, that must be applied before the `net.woggioni.gradle.graalvm.native-image`.
+
+The plugin adds 2 tasks to your project:
+
+- `configureNativeImage` of type `net.woggioni.gradle.graalvm.NativeImageConfigurationTask` which launches 
+   your application with the [native-image-agent](https://www.graalvm.org/latest/reference-manual/native-image/metadata/AutomaticMetadataCollection/)
+   to generate the native image configuration files in `${project.projectDir}/native-image`
+- `nativeImage` of type `net.woggioni.gradle.graalvm.NativeImageTask` that creates the native executable the project's 
+   libraries folder (`${project.buildDir}/libs`)
+
+#### Configuration for `NativeImageConfigurationTask`
+
+###### mergeConfiguration
+
+This boolean property decides whether to create a new set of configuration files or simply append to the existing ones
+
+#### Configuration for `NativeImageTask`
+
+###### mainClass
+
+The name of the main class the native executable will launch, defaults to the value set in
+
+```groovy
+application {
+    mainClass = 'my.main.class'
+}
+```
+
+###### mainModule
+
+The name of the main JPMS module the native executable will launch, defaults to the value set in
+
+```groovy
+application {
+    mainModule = 'my.main.module'
+}
+```
+
+Only applicable when `useJpms` is true
+
+###### useJpms
+
+Whether or not enable JPMS in the generated executable 
+(dependencies that support JPMS will be forwarded to `native-image` using the `-p` instead of the `-cp` option)
+
+###### useMusl
+
+This boolean property allows to link the generated executable to musl libc, 
+note that in order to do that a valid (linked to musl-libc) compiler toolchain must be available
+on the `PATH`, for example if building x86_64 executables on Linux, GraalVM will look for 
+`x86_64-linux-musl-gcc`
+
+###### buildStaticImage
+
+This boolean property allows to create a statically linked executable for maximum portability
+(a static executable only depends on the kernel and can be moved freely to
+another different machine with the same operating system and CPU architecture).
+Beware that this requires the libc to support static linking 
+(most notably, the glibc does not support static linking, the only way to build static executables 
+on linux is to link to a different libc implementation like musl libc).
+
+###### enableFallback
+
+Whether or not to allow the creation of the [fallback image](https://www.graalvm.org/22.0/reference-manual/native-image/Limitations/)
+when native-image configuration is missing.
+
+###### graalVmHome
+
+This points to the installation folder of GraalVM, defaults to the installation directory
+of the selected Gradle toolchain (if any) or the installation directory
+of the JVM Gradle is running on otherwise.
+
+#### Customize native-image command line
+A [native-image.properties](https://www.graalvm.org/22.0/reference-manual/native-image/BuildConfiguration/) 
+file can be added to `${project.projectDir}/native-image` to add custom parameters:
+
+```bash
+-H:Optimize=3 --initialize-at-run-time=your.main.class --gc=G1
+```
+
+#### Limitations
+
+GraalVM with the [native-image](https://www.graalvm.org/22.0/reference-manual/native-image/) plugin is required in order
+for these plugins to work, this can be achieved either running Gradle under GraalVM directly or using Gradle toolchains
+support to request GraalVM at the project level
+
+```groovy
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(17)
+        vendor = JvmVendorSpec.GRAAL_VM
+    }
+}
+```

graalvm/src/main/java/net/woggioni/gradle/graalvm/NativeImageConfigurationTask.java

@@ -10,12 +10,14 @@ import org.gradle.api.plugins.JavaPlugin;
 import org.gradle.api.plugins.JavaPluginExtension;
 import org.gradle.api.provider.Property;
 import org.gradle.api.provider.Provider;
+import org.gradle.api.tasks.Input;
 import org.gradle.api.tasks.JavaExec;
 import org.gradle.api.tasks.OutputDirectory;
 import org.gradle.api.tasks.TaskContainer;
 import org.gradle.api.tasks.bundling.Jar;
 import org.gradle.jvm.toolchain.JavaLauncher;
 import org.gradle.jvm.toolchain.JavaToolchainService;
+import org.gradle.process.CommandLineArgumentProvider;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -27,6 +29,8 @@ import static net.woggioni.gradle.graalvm.Constants.GRAALVM_TASK_GROUP;
 import static net.woggioni.gradle.graalvm.NativeImagePlugin.NATIVE_IMAGE_CONFIGURATION_FOLDER_NAME;
 
 public abstract class NativeImageConfigurationTask extends JavaExec {
+    @Input
+    public abstract Property<Boolean> getMergeConfiguration();
 
     @OutputDirectory
     public abstract DirectoryProperty getConfigurationDir();
@@ -50,6 +54,7 @@ public abstract class NativeImageConfigurationTask extends JavaExec {
         }
         getConfigurationDir().convention(layout.getProjectDirectory()
                 .dir(NATIVE_IMAGE_CONFIGURATION_FOLDER_NAME));
+        getMergeConfiguration().convention(true);
         ConfigurationContainer cc = getProject().getConfigurations();
         Configuration runtimeClasspath = cc.getByName(JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME);
         setClasspath(runtimeClasspath);
@@ -60,11 +65,20 @@ public abstract class NativeImageConfigurationTask extends JavaExec {
                 runtimeClasspath
             )
         );
-        List<String> jvmArgs = new ArrayList<>();
+        getJvmArgumentProviders().add(new CommandLineArgumentProvider() {
-        jvmArgs.add("-agentlib:native-image-agent=config-output-dir=" + getConfigurationDir().get());
+            @Override
-        for(String jvmArg : Optional.ofNullable(javaApplication.getApplicationDefaultJvmArgs()).orElse(Collections.emptyList())) {
+            public Iterable<String> asArguments() {
-            jvmArgs.add(jvmArg);
+                List<String> jvmArgs = new ArrayList<>();
-        }
+                if(getMergeConfiguration().get()) {
-        jvmArgs(jvmArgs);
+                    jvmArgs.add("-agentlib:native-image-agent=config-merge-dir=" + getConfigurationDir().get());
+                } else {
+                    jvmArgs.add("-agentlib:native-image-agent=config-output-dir=" + getConfigurationDir().get());
+                }
+                for(String jvmArg : Optional.ofNullable(javaApplication.getApplicationDefaultJvmArgs()).orElse(Collections.emptyList())) {
+                    jvmArgs.add(jvmArg);
+                }
+                return jvmArgs;
+            }
+        });
     }
 }

graalvm/src/main/java/net/woggioni/gradle/graalvm/NativeImageTask.java

@@ -87,7 +87,7 @@ public abstract class NativeImageTask extends Exec {
             javaToolchainService.launcherFor(javaToolchainSpec)
         ).map(javaLauncher ->
             javaLauncher.map(JavaLauncher::getMetadata).map(JavaInstallationMetadata::getInstallationPath)
-        ).orElseGet(() -> layout.dir(project.provider(() ->project.file(System.getProperty("java.home")))));
+        ).orElseGet(() -> layout.dir(project.provider(() -> project.file(System.getProperty("java.home")))));
         getGraalVmHome().convention(graalHomeDirectoryProvider);
 
         BasePluginExtension basePluginExtension =

gradle.properties

@@ -2,7 +2,7 @@ woggioniMavenRepositoryUrl=https://mvn.woggioni.net/
 
 lys.catalog.version=2023.10.01
 
-version.myGradlePlugins=2023.10.20
+version.myGradlePlugins=2023.10.23
 version.gradle=7.6
 version.felix.config.admin=1.9.26
 version.felix=7.0.5