Feedback on initial RFR for  "JDK-8212780: JEP 343: Packaging Tool Implementation" That needs to be addressed:

1.) CompileJavaModules.gmk:

The jdk.packager_CLEAN_FILES could be replaced with a simple "jdk.packager_CLEAN := .properties" unless you actually need to add all the platform specific files to builds for all platforms (which I doubt?). To clarify, the current patch will add all linux, windows and mac properties to builds of all OSes. Is that intended?

2.) Modules.gmk:

I would rather have the filter be conditional on an inclusive list of platforms. Other OpenJDK contributors are building for other OSes like AIX and we don't want to have to keep track of all those. The list of OSes that jpackager supports is well defined, so better check for those explicitly.

3.) src/jdk.jlink/share/classes/module-info.java:

I believe the qualified export needs to be put in a module-info.java.extra file since we filter out the target module on unsupported platforms.

4.) Launcher-jdk.packager.gmk:

* Please use $$(call FindExecutableDirForModule, $$(MODULE)) for the DEST dir in the copy.
* Please adjust the indentation of the big windows/else blocks. We indent everything with 2 spaces in conditional blocks.
* A minor style nit on the copy-and-chmod macro, since it's meant to be used as a recipe, we usually indent those with tabs to indicate that they are recipe lines, in this case, one tab is enough even though the surrounding define should be indented with 2 spaces (don't combine tab and spaces here).
* The (new) SetupJdkExecutable macro handles VERSIONINFO_RESOURCE automatically for you unless you have specific needs. This looks like the defaults should be fine.
* Since this is just for windows, the TOOLCHAIN_LINK_CXX should not make any difference. (It's only needed for GCC to force linking with g++ instead of gcc) So please remove.
* You could consider using FindSrcDirsForComponent for the src dir.

5.) Lib-jdk.packager.gmk:

* The native source files are not organized according to the standards introduced with JEP 201. If they were, most of these SetupJdkLibrary calls would automatically find the correct sources. I realize there is a special case for the windows papplauncherc executable as it's built from the same sources as papplauncher, so that will need a special case. Building of the executables should be moved to Launcher-jdk.packager.gmk however.
* Why are you changing the build output dir and copying debuginfo files around? We have a standard way of building and places where files are put. If that is not working for you, we need to fix it on a global level. Having each native library being built differently is not good for maintainability.
* VERSIONINFO_RESOURCE is handled automatically so does not need to be specified.
* Please indent the full contents of logic blocks with 2 spaces. Not having proper indents makes it much harder to read the code.
* Several lines are too long for future side by side comparisons, please break them up. You can use the # lines as a soft guidance. 

This may be broken up into separate sub-tasks - but initially tracking all with this bug.