Enabling the epoch serving-mode JIT globally regressed continuation-based guest
interpreters (the epoch mode is the shared command channel every loop's
conformance runner uses). Two-part fix:
1. SAFE DEFAULT GATE. register_jit_hook in the persistent server branch is now
opt-in via SX_SERVING_JIT=1 (default OFF). Default behaviour is unchanged
(no JIT in epoch serving) → zero regression for sibling loops. The
content/Smalltalk page server opts in.
2. GENERAL FIXES + per-guest interpret-only declarations:
- callable? (sx_server/run_tests/integration_tests/mcp_tree) now accepts
VmClosure. A JIT-compiled higher-order function returns its inner closure
as a VmClosure; callable? previously rejected it, so scheme-apply's
(callable? proc) guard failed with "not a procedure: <vm:anon>".
- jit-exclude! gains a trailing-"*" namespace-prefix form
(Sx_types.jit_excluded_prefixes), the robust way to mark a whole guest
interpreter interpret-only (a name-list misses functions in extra files —
it left erlang's vm/dispatcher JIT'd and 13 tests short).
- Per-guest exclusions in each guest's runtime.sx:
scheme "scheme-*" "scm-*" erlang "er-*" "erlang-*"
prolog "pl-*" common-lisp "cl-*" "clos-*"
js "js-*" haskell "hk-*"
Verified under opt-in JIT (== CEK, no hang): smalltalk 847/847, scheme/flow
166/166, erlang 530/530, prolog 590/590, apl 152/152, js 147/148. Residual
(documented, protected by the default gate): common-lisp 6 fails in advanced
suites (parser-recovery/debugger/CLOS/MOP). lua (0/16) and tcl (3/4) fail
identically on CEK — pre-existing, not JIT. run_tests --jit/no-jit unchanged.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
hk-bind-exceptions! in eval.sx registers throwIO, throw, evaluate, catch,
try, handle, displayException. SomeException constructor pre-registered
in runtime.sx (arity 1, type SomeException).
throwIO and the existing error primitive both raise via SX `raise` with a
uniform "hk-error: msg" string. catch/try/handle parse it back into a
SomeException via hk-exception-of, which strips nested
'Unhandled exception: "..."' host wraps (CEK's host_error formatter) and
the "hk-error: " prefix.
catch and handle evaluate the handler outside the guard scope (build an
"ok"/"exn" outcome tag inside guard, then dispatch outside) so that a
re-throw from the handler propagates past this catch — matching Haskell
semantics rather than infinite-looping in the same guard.
14 unit tests in tests/exceptions.sx (catch success, catch error, try
Right/Left, handle, throwIO + catch/try, evaluate, nested catch, do-bind
through catch, branch on try result, IORef-mutating handler).
Conformance: safediv.hs (8/8) and trycatch.hs (8/8). Scoreboard now
285/285 tests, 36/36 programs.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
