Someone asked us if bld could be used to generate native application with GraalVM. Our first reaction was, sure, you can create an extension to do just that. But after a bit of reflection, it dawned on me that it could easily be done using the bld-exec extension. The extension allows for executing applications from the command line.

The Maven plugin configuration given to us, as an example, looked something like:

<profile>
  <id>native-image</id>
  <build>
    <plugins>
      <plugin>
        <groupId>org.graalvm.nativeimage</groupId>
        <artifactId>native-image-maven-plugin</artifactId>
        <version>21.2.0</version>
        <configuration>
          <imageName>ExampleApp</imageName>
          <mainClass>com.example.ExampleApp</mainClass>
          <buildArgs>
            <!-- Reduces the image size - Ensures the native image doesn't include the
            JVM as a fallback option -->
            <buildArg>--no-fallback</buildArg>
            <!-- Disables the use of the GraalVM compilation server -->
            <buildArg>--no-server</buildArg>
            <!-- Improve startup time - Initialize classes at build time rather than at
            runtime -->
            <buildArg>--initialize-at-build-time</buildArg>
            <!-- Include all files under /resources -->
          </buildArgs>
        </configuration>
        <executions>
          <execution>
            <goals>
              <goal>native-image</goal>
            </goals>
            <phase>package</phase>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</profile>

That's a handful at first glance. But once you understand how the native-image utility options work, it is pretty easy to convert:

@BuildCommand(value = "native-exec", summary = "Builds a native executable")
public void nativeExec() throws Exception {
  new ExecOperation()
    .fromProject(this)
    .timeout(120)
    .workDir(buildMainDirectory().getAbsolutePath())
    .command("native-image",
        "--no-fallback",
        "--no-server",
        "--initialize-at-build-time",
        "com.example.ExampleApp",
        new File(workDirectory(), "ExampleApp").getAbsolutePath())
    .execute();
}

Just use ./bld compile native-exec, and you're off to the races.

I've created a full example to demonstrate how to build a native executable using a class or JAR.

After converting over 60 projects, I'm still impressed with how flexible (yet, simple) bld truly is.