> The JDWP implementation (debug agent) allows the writing of static final > fields and instance final fields. This has always been the case since no > checks are made to prevent it, and JNI doesn't prevent it. The JDI spec > forbids the setting of final fields, and it has a check that will throw an > exception if attempted. However, it is important that we continue to allow > JDWP to write final fields because some debuggers allow for it at the JDI > level (protected by a click through warning). Although these debuggers are > not fully JDI compliant, there is no requirement that they be compliant, so > JDWP should continue to support this behavior. Much of this was discussed in > the PR for [JDK-8281652](https://bugs.openjdk.org/browse/JDK-8281652), which > clarified in the JDI spec that writing final fields was not allowed. This was > just a spec clarification. JDI already forbid the setting of final fields. > > Having said all that, the JDWP spec for ClassType.SetValues says "Final > fields cannot be set." This is clearly wrong as it has always been allowed. > ObjectReference.SetValues says nothing about final fields, and also allows > them to be set. > > This PR has two spec updates: > - Get rid of the "Final fields cannot be set." text for ClassType.SetValues. > - ObjectReference.SetValues and ReferenceType.SetValues should warn against > setting final fields by using language similar to JNI. > > I've also updated two tests to test for setting both static final fields and > instance final fields. The tests (before my changes) verified the setting of > fields (not final) on the debuggee side. I tried the same with final fields > and ran into problems. The compiler inlines final primitives values, so > setting the final fields is not seen when the fields are referenced from java > (or at least this was the case with static final fields. I'm not positive > about instance final fields). So I added support for using GetValues to > verify the results rather than relying on the debuggee's view of the fields. > > Testing in progress. > > --------- > - [x] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai).
Chris Plummer has updated the pull request incrementally with one additional commit since the last revision: fix spelling and incorrect logging ------------- Changes: - all: https://git.openjdk.org/jdk/pull/32029/files - new: https://git.openjdk.org/jdk/pull/32029/files/aa71c226..5bc8a98a Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=32029&range=01 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=32029&range=00-01 Stats: 5 lines in 2 files changed: 0 ins; 0 del; 5 mod Patch: https://git.openjdk.org/jdk/pull/32029.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/32029/head:pull/32029 PR: https://git.openjdk.org/jdk/pull/32029
