# Session save — 2026-09-20 (m2compiler-V3, step 3 composites)

## Where we are

HEAD: `de18bdc` — `v3-step3.6`, suite **64/64** (30 run — incl.
3 trap-aborts — + 34 reject). Repo has no remote (push recipe in
untracked `git.txt`). Tree clean except `git.txt`.

## Tag lineage today (all green at every tag)

- `v3-step3.1` — arrays: bounded/open, strings as descriptors,
  whole-assign with count check + memcpy, index traps (42/42)
- `v3-step3.2` — showcase6 array tour → 34
- `v3-step3.3` — sets: multi-word masks, full expressions, all four
  ops + `IN`, word-wise `=` (51/51) + showcase7 → 219
- `0ed2862` (untagged docs) — strings/UTF-8 research notes
- `v3-step3.4` — records + `WITH`, deep copies, pointer-fields
  amendment (56/56); `v3-step3.5` — showcase8 everything-tour → 170
- `641a9b7` + `v3-blaise-sync` — Blaise phase map + plan refresh
- `v3-step3.6` — pointers: `FNil` upgrade, deref chains, `NEW`/
  `DISPOSE` via malloc/free (64/64)

Prior: v3-step1→1.11 substeps, v3-step2 (REALs), 1.12 TopSpeed
grammar sidecar (parallel track, `TopSpeed-V3-M2.atg`).

## Locked decisions (do not relitigate without cause)

- Arrays: LONGCARD-count headers, per-level nested objects,
  open formals as bare pointers, `blit` rejected (needs const
  length) → `memcpy`, string data flushed at EndModule.
- Sets: memory addresses, no header, literals `SET OF [0..255]`,
  lenient cross-base (masks decide), static 222s + runtime traps.
- Records: flat blobs, array fields as pointers (amended lock),
  declaration-order offsets+ranks, deep copy, `WITH` stacks.
- Pointers: `NIL` is a real type; `DISPOSE` nils (deviates Wirth)
  and is shallow; nil-deref raw; no-underscore/classic idents stay.
- Traps: `$abort`+`hlt` interim (rc=134), `runtime/syslib/Trap` later.
- QBE facts (probed, not guessed): extern calls need arg classes,
  immediates valid as stored values, `%tN` only (bare `%p`
  mislinks), `blit`/`alloc8` semantics, strict width checking.

## Open threads / next

1. **Hardening pass** (Blaise v0.12.0 lesson, recorded in
   `docs/blaise-phases-map.md`): thin-on-features, fuzz bounds/
   copies/traps/narrowing over the 64-suite before step 4.
2. **Step 4 calls**: call emission, C-ABI frames, value/VAR params,
   nested/display, DEFINITION/IMPLEMENTATION + opaque completion,
   `HIGH`/`LEN`, procedure-type vars. Biggest remaining phase.
3. Then: step 5 stdlib, 6 unicode/hardening, 7 syslib port
   (`grep` gate), 8 fixpoint (needs rolling-bootstrap design,
   not just 3-stage diff — see map).
4. Deferred everywhere: enum lowering/ordinals, CHAR arith policy,
   `LONGINT` quads, recursive `DISPOSE`, class lowering
   (vtable/`THIS`), `WITH`-field `VAR` actuals, LSP.

## Resume commands

```sh
cd /home/eric/Projets/Projets-Modula2/MyWork/m2compiler-V3/compiler
./build.sh && ./run_tests.sh   # expect 64/64
```
Then: hardening pass or step 4 design (ask which first).