Fix native-image-maven-plugin for Windows

[olpaw]

fixes #2151

[jonenst]

Hi @pejovica @olpaw
What is this PR supposed to fix ?

I think this pr breaks my build (links to public builds that show the problem at the end).
[INFO] Executing: C:\hostedtoolcache\windows\jdk\11.0.0\x64\bin\native-image.cmd -cp [... many many jars ] --no-fallback --allow-incomplete-classpath -H:Class=com.powsybl.tools.Main -H:Name=olf
The command line is too long.

The only change I see in the log is that native-image.exe is changed to native-image.cmd.

The command line generated by native-image-maven-plugin in my case is about 15k characters (all the jars).

I read that
""A little bit of google later, and I learn that Windows has a 32767 character command line limit. That limit is even less, 8191, if trying to execute the process from within cmd.exe.""

I'm not a windows user so I don't know much about limits, but maybe switching from .exe to .cmd reduced the max command line length ?

Thanks,

builds:
https://github.com/powsybl/powsybl-open-loadflow/runs/1414612072 (KO) (using native-image-maven-plugin 20.3)
https://github.com/powsybl/powsybl-open-loadflow/runs/1414671494 (OK) (using native-image-maven-plugin 20.1)

[olpaw]

The GraalVM directory layout was changed on Windows to be in line with other platforms (Linux & Darwin). Thus

getMojoJavaHome().resolve("bin").resolve("native-image" + (OS.WINDOWS.isCurrent() ? ".cmd" : ""));

now points to a "link" (in the case of Windows, a batch script because we cannot use symlinks on Windows) that forwards to the real location of the native-image executable. Note that this is the same for other GraalVM applications in $GRAALVM_HOME/bin (ployglot.cmd, js.cmd, gu.cmd, ...).

As you observed this has the unpleasant side effect that now because of going through a batch-file the Windows character command line size hits us even harder. Please open a ticket for this.

As a workaround you could create an uberjar out of all theses jars (e.g. with maven-shade-plugin) that then gets feed into native-image-maven-plugin. In this case the command line should be much shorter.