Java FU has such feature.
At first iteration, please implement simplified algorithm of RW access based only on lexer token stream (i.e. without semantic analyzing).
Created attachment 162388 [details]
Vladimir V, please review a patch.
Created attachment 162393 [details]
fixed in enum, branch release82, change set: 79216a5e0631
Integrated into 'main-silver', will be available in build *201610200002* on http://bits.netbeans.org/dev/nightly/ (upload may still be in progress)
User: Alexander Simon <firstname.lastname@example.org>
Log: fixed Bug #268402 Find Usages: mark differently read, write and read/write access to variable
(transplanted from 79216a5e063136c6fe1c40693ba40dafca542f53)
Verified in internal NetBeans 8,2 patch 1 build.