javadoc allows a file to be specified to provide content for the top
level "overview" page.
As we move towards a unified docs bundle, we need to be able to vary the
content of that file depending on the content of the bundle. This does
not mean providing or including lists of modules, but should reflect
whether the bundle contains Java SE modules, JDK modules and JavaFX
This patch also includes support for (and relies on) the new usage of
the -group option from JDK-8180336.
Note that when JDK-8180480 (Use "requires transitive" relationship when
determining modules for javadoc) is pushed, the call to
FindTransitiveDepsForModules for JavaSE_MODULES should be updated to the
new FindTransitiveIndirectExportsForModules (or whatever it'll end up
being called). I'll fix that in whichever of the two bugs I push last.
This patch also contains some accumulated cleanup in Docs.gmk after all
the piecemeal patches this file has recieved for the last few weeks.
Note: While I'm willing to make minor changes to the actual contents of
the generated overview.html, I'd prefer if any larger (or potentially
controversial) issues are handled as separate follow-up bugs. With this
framework in place, it's easy to modify whatever gets written to the file.
An example how this looks like for the JDK and Java SE documentation
collections (stripped down to the summary page of the javadoc output,
and the JDK top-level index.html) is here: