Proven by paranoid runs over lorep (17 classes, fully green),
LoVisual (4081 classes) and oc2r (1278 classes) with per-class
java -Xverify:all, each fix first reproduced as a red test:
- merge: Top absorbs instead of Top-wins (javac declares Top for
slots unwritten on some inflow; precise types reject those edges).
Regression: loop_head_keeps_top_for_loop_local.
- emit: collapse [Long|Double, Top] pairs on operand stacks
(javac writes one entry; the pair is rejected). Regression:
wide_stack_join_emits_single_entries.
- xfer ArrayLoad: push the wide pair, fixing lcmp underflow.
Regression: array_load_wide_pushes_pair.
- xfer <init>: convert only the receiver's own allocation site
instead of every Uninitialized (nested construction clobbered
the outer object). Regression: nested_construction_keeps_outer.
- xfer ANewArray: array operands gain one dimension ([B] -> [[B)
instead of an illegal L-wrap ([L[B;). Covered by the same test.
- jar load: duplicate class names (multi-release module-info
twins) keep the first occurrence instead of crashing save.
Test: duplicate_class_names_keep_first.
- strings/constants: skip methods past MAX_METHOD_INSNS (8000)
so giants cannot overflow the 64KB writer ceiling. Tests:
oversized_methods_are_skipped in both passes.
- merge errors now name both types being merged.
Also: em-dash removed repo-wide (724 spots, rule added to
todo.md), allow-lints only in tests (scratch example deleted),
code comments migrated to English in every file this change
touches.
FlowPass rebuilds one method per scheme picked from FlowConfig:
state-spread (dense tableswitch dispatcher), computed-switch
(sparse lookupswitch over a counter local), butterfly (branch
inversion), exception-goto (dispatcher under try with a dead
catch-all), plus opaque goto-splices inside every method and
StackMapTable recomputation afterwards. Now in standard_pipeline
(between constants and noise); --no-flow is an honest off-flag.
Acceptance is real JVM, not shapes: per-scheme verify, rotation
spread, calc-prints-45 execution, paranoid smoke on lorep-1.1.0
(131 methods rebuilt, no new failures over standard).
Two verifier rules learned the hard way are now construction
invariants: no inserted mark shares a bytecode offset with a
foreign one (nop pads), and no frameless gap follows a terminal
(dead blocks are opaque-entered and throw).
Also fixes a latent frame-emitter bug the pass exposed: wide
stack values were written as slot pairs ([Double, Top]) while
javac writes one entry ([Double]); HotSpot rejects the pair.
Stacks now collapse like locals (emit::stack_vars), with a
regression test in classfile/tests/frames.rs.
