Support class file versions through Java 25 (major 69) - #2
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The decoder guarded on `majorVersion > 63`, rejecting Java 20-25 class files even though all of their structures (attributes, constant pool tags, opcodes, stack map frames) already decode correctly. The format has been stable since Java 17 (major 61); no new structures were added in 20-25. Add a `ClassFormatVersion.Latest` constant (= Java25) and compare the decoder guards against it so the cap tracks the newest defined version automatically instead of drifting behind a magic number. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Summary
The decoder guarded on
majorVersion > 63, rejecting Java 20–25 class files even though all of their structures already decode correctly. This raises the cap to Java 25 (major 69).Background
I audited the full class-file surface against the JVMS through Java 25:
Dynamic,InvokeDynamic,Module,Package)NestHost/NestMembers,Record,PermittedSubclasses); full decode↔encode round-tripjsr_w, 201)The class file format has been stable since Java 17 (major 61,
PermittedSubclasses). Java 20–25 bumped the version number for compatibility gating and preview-feature binding, not for new permanent structures. So no new structures needed implementing — only the stale guard was blocking these versions.Changes
ClassFormatVersion.Latest(=Java25).majorVersion > 63guards (inTryMeasureandTryRead) with a comparison againstClassFormatVersion.Latest.Major, so the cap tracks the newest defined version automatically instead of drifting behind a magic number.Notes
StackMapFrame.CopyToroutes frame types 64–65 toSameStackMapFrame(valid only 0–63). Not version-related; can be a follow-up.🤖 Generated with Claude Code
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