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+# Session summary — 2026-10-16 (b): two-phase thread complete, `Check` removed
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+
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+Branch **`resolve-check`**, HEAD `a89a1c0`, tree clean. Suite
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+**201/201**; fixpoint **OK (3,555,791 bytes)**.
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+
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+Tags added this session: `v3-two-phase-m2a`, `m2b`, `m2c`,
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+`m2-summary`, `v3-two-phase-flip`, `v3-forward-machinery-deleted`,
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+`v3-two-phase-m2d-summary`, `v3-check-removed`.
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+
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+## What this session did
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+
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+1. **Landed milestone 2c** — real deferral + re-parse (behind
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+ `-twophase` then flipped on by default). Two bugs found and fixed:
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+ the re-parse loop clobbered the unit's `astDecl`/`astStmt`, and
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+ `PopPos` restored `errors`, wiping every diagnostic from repassed
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+ bodies. Details in `docs/summary_two-phase-m2-2026-10-16.md`.
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+2. **Pinned + fixed the spurious `ident expected`** (a `DeferSkip`
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+ snapshot leak: `PushPos` without `PopPos` on the success path, fixed
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+ with `scanner.DropPos`) and **flipped deferral on by default**
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+ (`-notwophase` restores the old inline parse).
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+3. **Deleted the forward-reference machinery** — the thread's original
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+ goal: `SymTab.FwdVarRef`/`FwdVarName`/`FwdVarResolve` (+ tables),
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+ `Check.NoteForward`/`FlushForward`, the `Design` forward branch, the
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+ dead `Check.SelType`/`LeafName`. New semantics: a module-level body
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+ may call a procedure declared later (no `FORWARD`); a nested-local
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+ forward is a plain `201` instead of a broken image. (Nested
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+ deferral was tried and reverted — it regressed nested-proc codegen.)
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+4. **Removed `Check` entirely** after proving it vestigial: gutting
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+ `Resolve` left the `.ssa` byte-identical across all 141 suite files
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+ and emitted no diagnostics. Deleted `Check.def`/`Check.mod`, its
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+ driver calls, the `-noresolve` option, and the atg import; dropped
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+ `build.sh`'s `Check`. Also removed the unused `procNest` and the
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+ always-true L7 flag `twoPhase`.
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+
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+## Architecture now
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+
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+```
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+per unit:
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+ Parse -> AST + declarations (procedure bodies are skipped and
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+ re-parsed at unit end, so forward references bind normally)
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+ Lower -> walk the AST, emit QBE (unchanged)
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+ Emit -> buffered image, EndModule
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+```
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+
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+No separate resolve/check pass: binding is late by construction.
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+`compiler/src` is `M2.atg` (grammar+scanner+parser+driver frames),
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+`FileIO`, `AST`, `SymTab`, `QbeGen`, `Lower`.
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+
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+## Verification
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+
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+- Suite **201/201** (`t_fwdproc -> 7`, `t_bad_nestfwd` `201`);
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+ `twophase_same` gate compares the default (deferral) against
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+ `-notwophase` for forward-free files; forward tests run to 42.
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+- **Fixpoint OK with deferral on** — the self-hosted compiler
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+ self-compiles byte-identically under the deferral.
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+- Corpus (612 gm2 testsuite files): **365 OK vs 358** with
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+ `-notwophase` — **+7 files, 0 regressions, 0 crashes**.
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+- `.ssa` byte-identical to pre-cleanup on spot-checks and the 141-file
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+ set.
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+
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+## Next
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+
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+1. **Generics: multi-formal instantiation link bug** (top — a real
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+ in-scope defect): `GENERIC … M(T,U)` + `X = M(INTEGER,CHAR)`
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+ compiles but fails to link (`undefined First_4`; the `.ssa` has the
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+ call but no body). Repro in `docs/summary_generics-2026-10-15.md`.
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+2. Generics increment 3 (const/proc params, constraints), `GENERIC
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+ CLASS`, instance dedup.
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+3. stdlib gaps; robustness (`M2` exit codes, weak recovery); the
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+ latent size-sensitive V3 miscompile.
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+
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+## Resume
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+
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+```sh
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+cd .../m2compiler-V3
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+git checkout resolve-check # HEAD a89a1c0
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+cd compiler && ./build.sh && ./run_tests.sh # 201/201
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+cd .. && ./bootstrap/fixpoint.sh # FIXPOINT OK
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+./M2 -notwophase tests/foo.mod # legacy inline parse (debug)
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+```
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