Support platform build args like `linux:--gc=G1`

[rbygrave]

Is your feature request related to a problem?

Some build args are only supported on certain platforms like --gc=G1 is supported on linux but not macos.

This forces apps using native-maven-plugin , that want to build on multiple platforms to use maven profiles to override the build args. Although this works:

• it is fairly verbose solution
• means a lot of build args are copy n paste to multiple locations.

Describe the solution you'd like
I'd like to be able to use platform prefixes like linux:, macos:, windows: with build args such that they are then only applied and used if the current build platform matches the prefix.

Example:

<buildArgs>
    <buildArg>linux:--gc=G1</buildArg>                   <!-- only use on linux-->
    <buildArg>linux:-R:MaxGCPauseMillis=50</buildArg>   <!-- only use on linux-->
    <buildArg>-R:MaxHeapSize=400m</buildArg>
    <buildArg>--emit build-report</buildArg>
    <buildArg>--no-fallback</buildArg>
    <buildArg>-march=compatibility</buildArg>
    <buildArg>--allow-incomplete-classpath</buildArg>
    <buildArg>--static-nolibc</buildArg>
</buildArgs>

Describe alternatives you've considered
The current maven approach is to use maven profiles like:

        <profile>
            <id>mac</id>
            <activation>
                <os>
                    <family>mac</family>
                </os>
            </activation>
          <!-- specify the buildArgs for mac -->

... which has the 2 issues of being verbose and introducing a decent amount of copy n paste.

Another approach would involve changing the xml schema in order to group build args by platform
like the linuxBuildArgs element below:

<configuration>
    <linuxBuildArgs>
        <buildArg>--gc=G1</buildArg>
        <buildArg>-R:MaxGCPauseMillis=50</buildArg>
    </linuxBuildArgs>
    <buildArgs>
        <buildArg>-R:MaxHeapSize=400m</buildArg>
        <buildArg>--emit build-report</buildArg>
        <buildArg>--no-fallback</buildArg>
        <buildArg>-march=compatibility</buildArg>
        <buildArg>--allow-incomplete-classpath</buildArg>
        <buildArg>--static-nolibc</buildArg>
    </buildArgs>
</configuration>

Additional context
Often we have the situation where we have developers building locally (using say macos)
and a CICD build pipeline on linux.

We want the local developer build on macos to work and we are mostly just looking to
filter out the [linux] platform specific args.

[vjovanov]

Interesting proposal, thank you for bringing it up.

To me this feels like a quality of life improvement for using profiles with maven activation and combine.children="append". The alternative to linuxBuildArgs would be to use:

<project>
    <build>
        <plugins>
            <plugin>
                <groupId>org.graalvm.buildtools</groupId>
                <artifactId>native-maven-plugin</artifactId>
                <configuration>
                    <buildArgs>
                        <buildArg>-R:MaxHeapSize=400m</buildArg>
                        <buildArg>--emit build-report</buildArg>
                        <buildArg>--no-fallback</buildArg>
                        <buildArg>-march=compatibility</buildArg>
                        <buildArg>--allow-incomplete-classpath</buildArg>
                        <buildArg>--static-nolibc</buildArg>
                    </buildArgs>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <profiles>
        <profile>
            <id>linux-native</id>
            <activation>
                <os><family>linux</family></os>
            </activation>
            <build>
                <plugins>
                    <plugin>
                        <groupId>org.graalvm.buildtools</groupId>
                        <artifactId>native-maven-plugin</artifactId>
                        <configuration>
                            <buildArgs combine.children="append">
                                <buildArg>--gc=G1</buildArg>
                                <buildArg>-R:MaxGCPauseMillis=50</buildArg>
                            </buildArgs>
                        </configuration>
                    </plugin>
                </plugins>
            </build>
        </profile>
    </profiles>
</project>

In the native plugins we are trying to keep the plugin surface minimal and provide only the functionality that can't be done (or it is very difficult) by other means. This feature mostly reduces the redundancy of XML blocks which in maven already exist in many places so it does not completely qualify for implementation.

I propose to wait for the community to vote this ticket up. If many people consider this important I would implement it, but until then we need to document how to work in cross-platform settings. How does this sound?