On Sat, 4 Oct 2025 05:09:27 GMT, Alan Bateman <[email protected]> wrote:
>> Implementation changes for [JEP 500: Prepare to Make Final Mean >> Final](https://openjdk.org/jeps/500). >> >> Field.set (and Lookup.unreflectSetter) are changed to allow/warn/debug/deny >> when mutating a final instance field. JFR event recorded if final field >> mutated. Spec updates to Field.set, Field.setAccessible and Module.addOpens >> to align with the proposal in the JEP. >> >> HotSpot is updated to add support for the new command line options. To aid >> diagnosability, -Xcheck:jni reports a fatal error when a mutating a final >> field with JNI, and -Xlog:jni=debug can help identity when JNI code mutates >> finals. For now, JNI code is allowed to set the "write-protected" fields >> System.in/out/err, we can re-visit once we change the >> System.setIn/setOut/setErr methods to not use JNI (I prefer to keep this >> separate to this PR because there is a small startup regression to address >> when changing System.setXXX). >> >> There are many new tests. A small number of existing tests are changed to >> run /othervm as reflectively opening a package isn't sufficient. Changing >> the tests to /othervm means that jtreg will launch the agent with the >> command line options to open the package. >> >> Testing: tier1-6 > > Alan Bateman has updated the pull request with a new target base due to a > merge or a rebase. The pull request now contains 34 commits: > > - Merge branch 'master' into JDK-8353835 > - Add test for -Xlog:jni=debug > - Merge branch 'master' into JDK-8353835 > - Merge branch 'master' into JDK-8353835 > - Improve CommandLineTest.testWarn > - More test cleanup > - Merge branch 'master' into JDK-8353835 > - Expand jni/JNIAttachMutatorTest to final fields in named modules > - Merge branch 'master' into JDK-8353835 > - Test updates based on reviewer feedback > - ... and 24 more: https://git.openjdk.org/jdk/compare/72319167...eed7ec4a src/java.base/share/classes/java/lang/reflect/Field.java line 982: > 980: } else { > 981: setFinal(Reflection.getCallerClass(), obj, () -> > fa.setByte(obj, b)); > 982: } Suggestion: if (!Modifier.isFinal(modifiers)) { fa.setByte(obj, b); } else { setFinal(Reflection.getCallerClass(), obj, () -> getOverrideFieldAccessor().setByte(obj, b)); } src/java.base/share/classes/java/lang/reflect/Field.java line 1027: > 1025: } else { > 1026: setFinal(Reflection.getCallerClass(), obj, () -> > fa.setChar(obj, c)); > 1027: } Suggestion: if (!Modifier.isFinal(modifiers)) { fa.setChar(obj, c); } else { setFinal(Reflection.getCallerClass(), obj, () -> getOverrideFieldAccessor().setChar(obj, c)); } ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/25115#discussion_r2410745955 PR Review Comment: https://git.openjdk.org/jdk/pull/25115#discussion_r2410751688
