Structural inference (2a) covers cyclic classes; this adds the DEMAND half for
the acyclic-but-aliased case, so @gc is now redundant everywhere.
- owner.ml: a `promote` sink on ctx. In collect mode, a class value that would
raise WO-E304 (escape) records its class instead of erroring — because a
class that MUST escape cannot be owned (second-class borrows can't be stored
or returned), so it must be traced. `class_of_ty` extracts the class from the
escaping local's type. analyze/analyze_fn take ?promote.
- main.ml typecheck_all: after structural injection, a fixpoint runs ownership
in collect mode over every file, unioning promotions into syms.traced (and
every module table), before owner/emit see it. Terminates (promotions only
grow, bounded by class count).
- gcinfer.render_final: --dump-gc now reads the authoritative is_gc_class
(structural + demand + the remaining @gc bridge), with the reason.
Effect: a class that escapes is inferred `gc` with no annotation — e.g. `Cache`
(rc.wo sans @gc) shows `gc (alias escape (demand))`; `Box` returned out of
`leak` is promoted and the program is valid. No false positives: employee's
Department/Employee stay owned; the 566 goldens + 14 test_diag unchanged.
Corpus: compile-fail/borrow-escape-return reclassified to run/ (prints 1) —
returning a borrowed class is now legal under demand promotion; the fixture
encoded pre-7b behavior.
Verified: woc-test 566/0 + test_diag 14/0; oop-e2e 79/0; employee 8/0;
log-watcher 7/0.
NOT in this slice: removing the `@gc` KEYWORD (parser rejection + rewriting the
RC/@gc golden + test_diag assertions + moving the inference injection into the
library so unit tests see it) — coupled to Phase 3, which deletes the RC
machinery those tests cover. The ring still needs Phase 3 to RUN (nullable
`?Node` gcref path).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
shoney.arickathil
6d589824e7