jolt/host/chez/seed
Dmitri Sotnikov e6e3612332
Devirt: fall back to dispatch when the static tag has no direct impl (#229)
The devirtualized protocol call emitted find-protocol-method on the inferred
record tag, but a record can satisfy a protocol via an Object/host-tag default
rather than a direct impl — find-protocol-method on its own tag misses that,
while protocol-resolve walks to the default. So a record relying on
(extend-protocol P Object ...) resolved under ordinary dispatch but applied #f
under devirt and crashed. Closed-world opt builds only; the gate previously
covered just direct inline/extend-type impls so it shipped green.

Emit devirt-resolve, which tries the static tag and falls back to
protocol-resolve on a miss — same fast path, correct regardless of how the
record satisfies the protocol. Mirrors jrec-field-at falling back to jolt-get.
The receiver binds to one temp so it feeds the resolve and the application
without double-evaluating a side-effecting arg 0.

Also widen the whole-program fixpoint to :any on hitting the iteration cap: a
non-converged pre-fixpoint is more specific than the least fixpoint, so seeding
it would be unsound. Not reached in practice (~2 passes); a defensive floor.

run-devirt.ss gains an Object-default case. make test / shakesmoke green,
selfhost holds, 0 new divergences.

Co-authored-by: Yogthos <yogthos@gmail.com>
2026-06-26 13:58:23 +00:00
..
image.ss Devirt: fall back to dispatch when the static tag has no direct impl (#229) 2026-06-26 13:58:23 +00:00
prelude.ss See through or/and in truthy-elision (#224) 2026-06-26 06:11:35 +00:00
README.md Docs: Chez-only, drop the Janet-era references and obsolete migration notes 2026-06-22 09:05:35 -04:00

Chez bootstrap seed

These two files are the bootstrap compiler for jolt — the seed that makes the build self-hosting:

  • prelude.ss — the clojure.core prelude (all tiers + clojure.string/walk/ template/edn/set/pprint) as Scheme def-var! forms.
  • image.ss — the compiler image (jolt.ir + jolt.analyzer + jolt.backend-scheme) as Scheme def-var! forms.

Both are generated, not hand-written. They are checked in because a fresh checkout must be able to build jolt-on-Chez using only Chez: host/chez/bootstrap.ss loads this seed, then rebuilds the prelude + image from the .clj/.ss sources via the on-Chez compiler (read → analyze → emit, all on Chez). The seed is a joint byte-fixpoint: rebuilding from an up-to-date seed reproduces it exactly. make selfhost (host/chez/selfcheck.sh) runs host/chez/bootstrap.ss and diffs the rebuilt artifacts against the checked-in seed.

Re-minting

When the seed sources change (the core tiers, the compiler namespaces, the host contract, the reader, emit-image.ss), the seed drifts and make selfhost fails. Re-mint it by running host/chez/bootstrap.ss and writing the freshly rebuilt prelude/image back to host/chez/seed/prelude.ss / host/chez/seed/image.ss, then commit the refreshed files.