Support '-m, --module' options from Javac

[kriegaex]

This is a clone of https://bugs.eclipse.org/bugs/show_bug.cgi?id=578320, because the issue was never imported and had no reactions on Bugzilla either for three years.

ECJ does not support the -m, --module options from Javac. In connection with --module-source-path, this would enable users to compile a (set of) module(s) without explicitly specifying all source files, because they would be found automatically.

Javac has this option:

--module <module>(,<module>)*, -m <module>(,<module>)*
      Compile only the specified module(s), check timestamps

It works like this (added line breaks for readability):

javac
  --release 11
  -d bin
  --module-path "c:\Program Files\Java\AspectJ\lib\aspectjrt.jar"
  --module-source-path "modules/*/src"
  --module org.acme.first,org.acme.second

I actually bumped into this because of the AspectJ compiler. You probably remember that AJC is a (regularly refreshed) ECJ fork, hence affected indirectly, see eclipse-aspectj/aspectj#119. Therefore, implementing this in order to be compatible with Javac would not only enable ECJ users to do the same things as Javac users from the console or from Maven, but also benefit the AspectJ project as a side effect.

See eclipse-aspectj/aspectj#118 (comment) and the linked ZIP archive, if you need an example project with two modules to play with.

[jukzi]

had no reactions

When it's not a priority for any jdt commiter you should consider to suggest a PR

[kriegaex]

Thanks for never getting tired to tell me what I am supposed to do. Also thanks for explaining to me that no reaction can only mean low priority and not maybe oversight, i.e. I am supposed to magically know that someone has actually read and prioritised the issue.