VM catch frames + expression-form try/catch in the compiler. Uncaught traps
keep byte-for-byte today's surface. log-watcher parse errors 18 -> 7;
corpus 71/0, woc runtest 565/0, wovm unit gates green (both dispatch flavors).
- wob.h: WOP_TRY (A sBx: push catch frame, handler at pc+sBx) / WOP_ENDTRY;
WO_B_ERR_FILL builtin (fills the catch record: 0 code, 1 line, 2 method,
3 msg — the field-order contract with the compiler)
- vm.h/vm.c: catch stack (depth, handler pc, error reg) + the caught error;
vm_unwind takes a stop depth, so a caught trap kills every frame above the
catching one exactly as an uncaught trap would, then releases only what the
try region owned in the catching frame (drop-entry diff against the handler
pc) and resumes at the handler; RET/RET0 drop the catch frames of the frame
they leave; TRAPF resumes instead of returning when the trap was caught
- builtin.c: err_fill allocates the method/msg Texts into the record the
compiler owns, so the pending error never has to outlive the landing
- loader.c: TRY's handler target validated like a jump, error register like
any register operand; err_fill arity
- lexer/token/ast/parser: `try`/`catch` keywords; `try expr catch (e) expr`
and `catch (e) { block }`, newline allowed before `catch`; try binds looser
than every operator, so `try a / b catch (e) 0` catches the division
- types.ml: predeclared `Error` record (merged table only), catch binding,
arm-type agreement reported only when both arms are confidently typed
- owner.ml: analyze_try — the catch arm is an alternate flow join off the
entry state, the error record is an owned handler-scope local
- emit.ml: TRY/body/ENDTRY/JMP + handler prologue (NEW Error, err_fill),
join drops on both arms, `Error` class entry only for programs that catch
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
- Modules: `use`/`pub`, directory-as-module, per-module symbol resolution (a
flat first-wins merge silently ran the wrong `pub fn` body), six reserved
stdlib namespaces typed UNKNOWN-BUT-RESERVED.
- Surface: `and`/`or` (own precedence tier, short-circuit, Bool-only), `${}`
interpolation desugared at parse time, `const`, break/continue with
drop-correct exits, do-while, inline-fn rejection.
- switch expr/stmt: required `default` over scalars/Text, arm unification,
EQ/EQS+JZ lowering, per-arm drop scopes with N-way JOIN-DROP; `default`
sorted last by a shared lowering order (textual order made arms dead).
- typedef records: structural, same shape = one class entry; `?name: T`
nullable-by-shape; emit_ctor fills omitted defaults; `type` as field name.
- Enum variants: all-bare unions = int ordinals; any-payload = one class
entry per variant, tag IS the header class_id (no header field, no format
bump); exhaustive switch without `default`; arity checked both directions.
- Payload escape modeled as move-out (pointer-kind fields only — a scalar
escape is a copy); caller reaps owned heap temps passed by borrow: two
unbounded LSan-blind leaks, 10.5 MB -> 1.5 MB flat over 300k iterations.
- Fixed en route, each with a RED repro: dead E209 builtin-arg check and
`int_to_text` missing from both types.ml builtin tables (both segfaulted
wovm), multi-file phantom double-report, emit_ctor's field temp clobbering
dst in tail position (pre-existing), warnings swallowed without an error.
- Two fenced VM builtins: `int_to_text` (13), `variant_tag` (14).
- 14+565 unit (was 14+401), corpus 71 (was 32) plain and under wovm_asan,
wovm-test + cli_smoke green. Log-watcher 307 -> 93 diagnostics (85 E101 /
4 E207 / 1 E208 / 3 W202); the 5 non-E101 residuals await Task 7 grammar.
- `woc` now emits `.wob` that `wovm` runs: emit.ml lowers the typed,
owner-annotated AST (scope-stack registers with a >64 WO-E401 diagnostic,
Lua-style call windows, ICALL by slot, dedup const pool, drop maps, line
tables, implicit terminators); disasm.ml backs `--dump-bc` goldens.
- Ownership lowering consumes the four owner tables verbatim; RESIDUAL is the
only source of borrow ops, coalesced per operand. Review caught the emitter
consuming only 2 of owner.ml's 4 residual producers — an assignment-anchored
aliasing violation ran to exit 0 instead of trapping; fixed, plus a backstop
raising WO-E404 for any residual region left unconsumed.
- Conformance harness `scripts/oop-e2e.sh` (`just oop-e2e`): four fixture
kinds with exact outcomes — byte-exact stdout, one WO-E### anchored on
`error CODE:`, numeric trap code, gc trace. 25 fixtures incl. pricing-demo
logic, the ownership suite, and DB_STUB's parse-but-trap. `tests/` un-ignored
so the corpus is actually tracked.
- `woc build` produces a self-contained binary: wovm copy + appended image +
20-byte trailer, self-exec via /proc/self/exe. Verified relocated outside
the repo, argless, and against adversarial trailer corruption.
- Milestone 1's five spec criteria all MET (`just oop-accept`). Criterion 3
closed by WO-E405 — the entry must return `Int`, since program mode already
says its return value is the exit code — which deletes the leak class
without adding return-type metadata to the format. `gc/held-cycle` retired:
an externally-held cycle is not expressible in a post-exit pump.
- New spec: inferred GC + incremental per-shard tri-color mark-sweep, retiring
`@gc` and reference counting. Story gains iterations 7b (that work) and 9b
(`@table`, relations, compiler-checked query); `.dev/reference` gains a
sparse System.Linq checkout. Priority: 5→6→7 (log-watcher) then 7b, 8, 9, 9b.
- 16 tasks complete: arena, object model, borrow word, containers,
RC + budgeted cycle collector, wob_build, validating loader,
interpreter core (dual dispatch), object opcodes, drop-map unwinding,
builtins + DB_STUB + TRAP, ICALL, wovm CLI + just recipes
- 13 test suites × 2 dispatch flavors (ASan+UBSan) + CLI smoke, all green
- .wob v1 format pinned in src/wob.h + docs/plan/oop-vm/00-wob-format.md
- wo-rt.c reference event-loop preserved for sub-project 2
This is Iteration 2 of the OOP milestone; compiler front (Iteration 3)
is in progress on this branch. They meet at Iteration 4 (emitter+e2e).
