[vlsi]

JSpecify does not recognize a nullness annotation on the root type of a local variable, so @Nullable V value = cache().compute(...) makes no claim about nullness even though it reads like one. NullAway's new JSpecifyUnrecognizedAnnotationLocation check reports each of them:

A nullness annotation on the root type of a local variable has no meaning under JSpecify.

The build promotes every Error Prone suggestion to a warning (allSuggestionsAsWarnings) and CI compiles with -Werror, so the 53 annotations left in caffeine, jcache and simulator fail the build as soon as the check is released. #2008 removed the first two, and the Build caffeine with snapshot job of uber/NullAway#1787 is red on the rest today.

Drop the annotation, and let var carry the declaration wherever the local allows it, which is 43 of the 53. The null checks, the nested type-use annotations such as (K k, @Nullable V currentValue) ->, and @Var stay where they are. Ten declarations keep an explicit type for reasons that have nothing to do with nullness: five have no initializer, WindowTinyLfuPolicy.evictFromWindow initializes from null, which javac cannot infer a type from, and the four reads of lvElement in MpscGrowableArrayQueue are declared Object on purpose, since var there infers E and makes the (E) e casts that follow redundant.

.claude/rules/errorprone.md warned that var widens an inferred @Nullable type to non-null, and told the reader to give the local an explicit @Nullable-typed declaration, which is the annotation this check reports. The bullet was written against NullAway 0.13.8 and no longer holds: its own example, values.stream().reduce(...).orElse(null) assigned to a local and returned as @Nullable T, compiles clean under 0.14.2-SNAPSHOT both with var and with an explicit type, as do the 43 locals converted here. Remove it.

Every Java compile task in the four modules, tests and the specialized suites included, builds against a NullAway snapshot carrying the check and reports nothing. The jcache and simulator suites pass; the caffeine @CacheSpec matrix is left to CI.

[Copilot]

🟢 Approval recommended

The changes are mechanical nullness-annotation removals aligned with JSpecify/NullAway behavior and do not alter runtime logic.

Pull request overview

This PR removes @Nullable annotations applied to the root type of local variables, which JSpecify treats as a no-op and which NullAway will soon warn on (JSpecifyUnrecognizedAnnotationLocation) under the project’s -Werror build configuration.

Changes:

• Removed root-type @Nullable annotations from local variables across caffeine, jcache, and simulator code, relying on NullAway’s local nullness inference from assignments instead.
• Dropped an unused org.jspecify.annotations.Nullable import in CacheusPolicy.
• Updated .claude/rules/errorprone.md guidance to discourage var and root local @Nullable in this scenario.

File summaries

File	Description
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/two_queue/TwoQueuePolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/two_queue/TuQueuePolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/two_queue/S3FifoPolicy.java	Removes root local @Nullable on a reassigned local used in null checks.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/sketch/WindowTinyLfuPolicy.java	Removes root local @Nullable on locals inferred nullable via assignments/null initializers.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/sketch/segment/S4WindowTinyLfuPolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/sketch/segment/RandomWindowTinyLfuPolicy.java	Removes root local @Nullable on a mutable local assigned from data.get.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/sketch/segment/LruWindowTinyLfuPolicy.java	Removes root local @Nullable on a mutable local assigned from data.get.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/sketch/segment/FullySegmentedWindowTinyLfuPolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/sketch/feedback/FeedbackWindowTinyLfuPolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/sketch/feedback/FeedbackTinyLfuPolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/sketch/climbing/HillClimberWindowTinyLfuPolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/linked/SievePolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/linked/SegmentedLruPolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/linked/S4LruPolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/linked/MultiQueuePolicy.java	Removes root local @Nullable on a mutable local assigned from data.get.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/linked/LinkedPolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/linked/FrequentlyUsedPolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/irr/LirsPolicy.java	Removes root local @Nullable on a mutable local assigned from data.get.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/irr/Lirs2Policy.java	Removes root local @Nullable on a mutable local assigned from data.get.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/irr/IndicatorFrdPolicy.java	Removes root local @Nullable on a mutable local assigned from data.get.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/irr/HillClimberFrdPolicy.java	Removes root local @Nullable on a mutable local assigned from data.get.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/irr/FrdPolicy.java	Removes root local @Nullable on a mutable local assigned from data.get.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/irr/DClockPolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/irr/ClockProSimplePolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/irr/ClockProPolicy.java	Removes root local @Nullable on locals inferred nullable via assignments/null checks.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/irr/ClockProPlusPolicy.java	Removes root local @Nullable on locals inferred nullable via assignments/null checks.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/greedy_dual/GDWheelPolicy.java	Removes root local @Nullable on a mutable local assigned from data.get.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/greedy_dual/GdsfPolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/greedy_dual/CampPolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/adaptive/CacheusPolicy.java	Removes root local @Nullable and drops the now-unused @Nullable import.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/policy/adaptive/ArcPolicy.java	Removes root local @Nullable on a data.get result.
simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/BasicSettings.java	Removes root local @Nullable on a parsed value that is explicitly null-checked.
jcache/src/main/java/com/github/benmanes/caffeine/jcache/LoadingCacheProxy.java	Removes root local @Nullable on a local assigned from @Nullable getOrLoad.
jcache/src/main/java/com/github/benmanes/caffeine/jcache/CacheProxy.java	Removes root local @Nullable on locals inferred nullable through assignments/branches.
caffeine/src/main/java/com/github/benmanes/caffeine/cache/MpscGrowableArrayQueue.java	Removes root local @Nullable on locals guarded by null checks / requireNonNull.
caffeine/src/main/java/com/github/benmanes/caffeine/cache/LocalLoadingCache.java	Removes root local @Nullable on a local assigned from compute(...).
caffeine/src/main/java/com/github/benmanes/caffeine/cache/Interner.java	Removes root local @Nullable on putIfAbsent result checked for null.
caffeine/src/main/java/com/github/benmanes/caffeine/cache/BoundedLocalCache.java	Removes root local @Nullable on locals inferred nullable via assignments and explicit null checks.
.claude/rules/errorprone.md	Updates NullAway guidance: avoid var here and avoid root local @Nullable under JSpecify.

Review details

• Files reviewed: 39/39 changed files
• Comments generated: 0
• Review effort level: Lite

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[Copilot]

🟢 Approval recommended

The changes are mechanical, preserve existing null checks/logic, and are aligned with the stated goal of preventing upcoming NullAway JSpecify-local warnings from breaking builds.

Review details

• Files reviewed: 39/39 changed files
• Comments generated: 0 new
• Review effort level: Lite