[foreign] RFR 8220544: Jextract; library dependent header filtering

[Jorn Vernee]

Updated webrev: 
http://cr.openjdk.java.net/~jvernee/panama/webrevs/8220544/webrev.01/

Fixed the bug, also added tests & ran all the examples again to try and 
find other bugs (nothing found).

Thanks,
Jorn

Jorn Vernee schreef op 2019-03-13 17:50:
> Discovered a bug in this after posting :(
> 
> DependencyFinder also needs to look for pointee and array element type
> cursors (which it currently doesn't). I've tested a working fix, but
> will also add some tests for the particular cases. Updated webrev
> coming soon™
> 
> Jorn
> 
> Jorn Vernee schreef op 2019-03-13 17:21:
>> Hi,
>> 
>> After some discussion:
>> https://mail.openjdk.java.net/pipermail/panama-dev/2019-March/004828.html
>> 
>> I've implemented the discussed approach to header & declaration 
>> filtering.
>> 
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8220544
>> Webrev: 
>> http://cr.openjdk.java.net/~jvernee/panama/webrevs/8220544/webrev.00/
>> 
>> There are a few new implementation classes:
>>   * PattertnFilter; a helper class that encapsulates the Pattern based
>> filtering code previously found in SymbolFilter. This code had to be
>> reused.
>>   * Filters; a Context sub-component holding PatternFilters for
>> different types of declarations.
>>   * DependencyFinder; finds dependencies of the root set of
>> declarations found in the root headers.
>>   * ElementFilter; filters out non-library symbol elements based on
>> whether they appear in a root header or are required by something
>> therein.
>>   * RootSet; a helper class for managing root headers + required 
>> element Trees.
>> 
>> I also encountered some crashes when debug printing Trees, which I've
>> fixed/worked around accordingly.
>> 
>> FWIW, I tried this out with the Windows registry API and it's working
>> very nicely! Going from well over 100 headers to under 10. Some room
>> for improvement still exists; some empty headers and static forwarders
>> could still be omitted, but imho that should be handled by a separate
>> patch.
>> 
>> Thanks,
>> Jorn