Detect EqualsUsingHashCode when hashCode results are stored in locals - #6019
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kalayciburak wants to merge 1 commit into
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Detect EqualsUsingHashCode when hashCode results are stored in locals#6019kalayciburak wants to merge 1 commit into
kalayciburak wants to merge 1 commit into
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EqualsUsingHashCode previously only recognized direct hashCode() comparisons in the return expression. Equivalent equals implementations that extract both hash codes into locals before comparing them were missed. Track locals initialized solely from hashCode() and flag when the terminal return condition compares only those values. Fixes google#5830
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Summary
EqualsUsingHashCodeonly recognized directhashCode()comparisons inside thereturnexpression. Runtime-equivalentequalsmethods that store both hash codes in locals and then compare those locals were missed (false negative).This change tracks locals initialized solely from
hashCode()(and not later reassigned) and reports when the terminal return condition is an equality comparison of only those hash-derived values. The existing terminal-condition behavior for&&guards is preserved (hash comparison must be the rightmost/&&terminal part).Fixes #5830
Test plan
mvn -pl core -am test -Dtest=EqualsUsingHashCodeTest -Dsurefire.failIfNoSpecifiedTests=false(JDK 21) — 6/6 GREENinstanceofguard positive