2 Commits

Author SHA1 Message Date
Brummel 76b21c00eb feat(lang): eliminate the Implicit ownership default — totality + the drop-soundness it demasks (#55)
Deletes `ParamMode::Implicit`. `ParamMode` is now `{Own, Borrow}`:
every fn-type slot on every signature carries an explicit `own` or
`borrow`, no defaulted position survives anywhere (model 0008 §2,
spec 0062). The parser rejects a bare fn-type slot; `borrow-return`
and `borrow-over-value` reject at the signature; the corpus is
migrated to minimal-ownership modes (consumed ⇒ own, read-only-heap
⇒ borrow, value ⇒ trivial-own). The documented `Implicit`-ret-mode
leak is fixed: an owned heap return now drops exactly once (live=0,
acceptance criterion 5).

This was the easy half. Removing the default ACTIVATED a family of
drop paths that `Implicit` had silently skipped — the pre-cutover
language was leaking (and in places mis-dropping) here rather than
crashing, because an Implicit scrutinee turned the drop off. Making
the modes explicit (Own) turned those paths on and exposed two
latent-bug clusters, all fixed RED-first as part of this cutover:

Drop-soundness family (four legs):
  A. lit-sub-pattern double-free — the desugar re-matched the same
     owned scrutinee in the lit fall-through; fixed by grouping
     consecutive same-ctor arms into one match (bind fields once),
     in ailang-core desugar.
  B. Cons-husk leak on non-tail arm bodies — the lit-sub-pattern
     desugar rebound the owned scrutinee via `Let $mp = xs`, which
     bumped consume_count and suppressed the existing fn-return
     partial_drop. Fixed by not rebinding a bare-Var scrutinee
     (one husk-freeing mechanism, not two).
  C. polymorphic `drop_<T>` rc_dec'd monomorphised value fields —
     the per-ADT drop fn was emitted once from the polymorphic
     TypeDef, defaulting type-var fields to ptr and rc_dec'ing
     inline Ints (segfault). Fixed with per-monomorph drop
     functions (new ailang-codegen::dropmono): the drop set is
     collected from the lowered MIR, value-type fields are skipped,
     heap fields still freed once; monomorphic-concrete ADTs keep
     their byte-identical un-suffixed drop symbol.
  D. static Str literal passed to an `(own Str)` param — the
     literal lowers to a header-less rodata constant; the callee's
     now-active rc_dec read its length field as a refcount and
     freed a static address (segfault). Fixed with the missing
     fourth StrRep::Static→Heap promotion in lower_to_mir's App arm,
     gated on Own mode (borrow args stay static, no regression).

over-strict-mode lint over-fired: it suggested `(borrow V)` for
value-typed params (which `borrow-over-value` rejects — own is the
only legal mode there) and fired on `(intrinsic)` bodies (whose
consumption the linearity walk cannot observe). Tightened to skip
both; contract 0008 updated to the narrowed firing scope.

Irreversible step — canonical-form hash reset (model 0008 §6,
acceptance criterion 6). Every signature now carries explicit modes,
so the hashable canonical JSON changed for every module. RATIFY:
the corpus-wide hash-pin reset (hash_pin, prelude_module_hash_pin,
mono_hash_stability, eq_ord_e2e, embed_export_hash_stable, the
ct4/iter*/loop_recur schema-extension pins) and the list ir_snapshot
golden were regenerated once, deliberately, as the intended one-time
consequence of removing the mode elision from the canonical form —
not a regression. Each regenerated hash verified deterministic across
two runs.

Also fixes a pre-existing latent failure surfaced by the verification
gate, unrelated to this cutover: the `every_contract_names_a_resolvable_
ratifying_test` resolver (design_index_pin) could not resolve the
" + " dual-link ratifying-test form (`uniqueness.rs + linearity.rs`)
that the #57 audit-close (dfdc65f) introduced — it shipped red on that
commit. Resolver taught the dual-link form, mirroring its sibling.

Verification: cargo test --workspace = 731 passed, 0 failed (twice,
stable); e2e 102 passed, no binary exits non-zero (corpus crash-free);
grep-clean for Implicit/fn_implicit/mode_eq across crates; every drop
fix confirmed via emitted IR + AILANG_RC_STATS balance on the head==K,
head!=K, and Nil paths. Three BLOCKEDs en route (the unsound first
husk-dec attempt, the over-strict derivation premise, the leg-B fix
direction) were each treated as a real design/spec gap and rediagnosed,
not patched over.

Supersedes #54 (return-position-only leak patch). Precondition #57
(linearity hardening) was already met. Spec docs/specs/0062, plan
docs/plans/0121.

closes #55
2026-06-02 00:03:46 +02:00
Brummel aa49a56d5a fieldtest: kernel-extension-mechanics — 6 examples, 9 findings (3 bugs, 1 friction, 1 spec_gap, 4 working)
Post-audit fieldtest for the kernel-extension-mechanics milestone.
Fieldtester wrote 6 .ail consumer programs against the public
interface only (design ledger + spec + ail CLI; no source crate
reads), one per axis with two for the param-in pair (accept +
reject). All artefacts in examples/fieldtest/ + the spec.

**Working (4):** F5 NewTypeNotConstructible diagnostic is precise
(names the home module + missing def in one sentence). F6 Term::New
codegen-deferral diagnostic explicitly names the raw-buf milestone
where support lands. F7 param-in accept-path is end-to-end (check +
build + run prints 17). F8 ParamNotInRestrictedSet names type-arg
+ var + TypeDef.

**Bugs (3, action: debug):**

- F1 (axis 1) — Same-module type-scoped call `(app Type.member …)`
  rejected with phantom-qualified `expected <this>.T, got T`.
  Bare `(app member …)` from inside Type's home module works.
  Spec's "Canonical form decision" promises type-scoped works
  uniformly; the resolver appears to disagree with the workspace
  pre-pass on whether `<this-module>.T` equals bare `T`. Repro:
  examples/fieldtest/kem_2b_min_repro.ail.

- F3 (axis 3) — Kernel-tier auto-import scopes the name but does
  not register the module as a resolvable qualifier prefix. Per
  the pre-pass, a bare `StubT` in a type slot is qualified to
  `kernel_stub.StubT`; the resolver then rejects `kernel_stub`
  as unknown. Asymmetric: prelude's free fns work (per
  prelude_free_fns.rs), but the stub's TypeDef is effectively
  unreachable from any consumer. Repro:
  examples/fieldtest/kem_3_stub_consumer.ail.

- F4 (axis 3, spec/ship coherence) — The spec's prep.3 worked-
  consumer relies on `(new StubT 42)`, but the shipped STUB_AIL
  has only a TypeDef + ctor — the `(fn new ...)` the spec
  designed is missing from the implementation. The diagnostic
  the resolver does emit on the consumer (F5) is precise; the
  bug is the absent def itself. Resolution: re-add the `new` to
  STUB_AIL (the spec's design), refresh the drift pin.

**Friction (1, action: plan-or-defer):**

- F2 — Loader's sibling-only module resolution forces symlinks
  for any cross-module fixture sitting outside the canonical
  `examples/` directory. The kem_1 example required local
  symlinks for std_list.ail + std_maybe.ail. Secondary: the
  diagnostic message names only the .ail.json path even though
  .ail also resolves — actively misleading. Recommended: small
  tidy iter for loader workspace-search-path + diagnostic clarity.

**Spec-gap (1, action: ratify):**

- F9 — `design/models/0007-kernel-extensions.md:80` uses `unit`
  as a value literal of type Unit; the checker treats it as a
  Term::Var lookup and emits [unbound-var]. Either ratify `unit`
  as the canonical Unit-value literal in the language, or tighten
  the design model to use the existing idiom. The current model/
  surface disagreement is a small but real LLM-author trap.

**Symlinks committed** as evidence of the F2 workaround:
examples/fieldtest/std_list.ail and std_maybe.ail are symlinks
into ../. They are the fingerprint of the friction — removing
them silently would erase the evidence.

Per Iron Law, fieldtester did not work around bugs — they were
all surfaced and recorded. The kem_2b_min_repro.ail fixture
exists specifically because F1 surfaced mid-drafting and got
minimised; kem_3_stub_consumer.ail also stays as the F3 RED-side
fixture.

Triage (next-step routing for /boss):

  F4 → small inline fix (add (fn new ...) to STUB_AIL + drift refresh)
  F9 → small inline ratify (whitepaper edit)
  F2 → backlog issue, deferred (single tidy iter someday)
  F1, F3 → debug skill dispatches, then implement mini-mode
  F5-F8 → carry-on, recorded as wins
2026-05-28 19:19:00 +02:00