# Session save — 2026-09-23 (m2compiler-V3, step 8.3)

## Where we are

HEAD `bb94cad`. Tags `v3-step8.2`, `v3-step8.2-summary`, `v3-step8.3`.
Suite **105/105**, build warning-free, tree clean, no remote
(`git.txt` untracked).

**Both hand-written compiler modules compile clean under V3:**
`SymTab` (step 8.2) and `QbeGen` (this step).

## What this session did

- **8.2 — self-compile gaps** (`docs/summary_step8.2.md`):
  named-CONST folding, forward type refs in a `TYPE` block, trailing
  `;` in records, qualified type names (`Module.Type`), table
  capacities (256→4096 types), compact `z`-filled array data.
- **8.3 — this step** (`docs/summary_step8.3.md`):
  1. Within-module forward procedure calls in `QbeGen.mod`: gm2's
     `FORWARD` is unusable (whole-program pass errors
     `too many errors in pass 3`; reproduced minimally) and reorder
     cascades. Fix = declare the 10 internal helpers in
     `QbeGen.def` (already the "everything the parser calls" surface).
  2. Single-char string literals to `ARRAY OF CHAR`:
     `QbeGen.DeclCharStr` + `ActParam` coercion; cleared the last
     85 QbeGen errors.
  3. Empty statements `StatSeq = Statement { ";" [ Statement ] }`
     (Coco/R emits `;;`); new test `t_emptystat` (42).

## Measured state of self-compilation

| Source | Under V3 |
|---|---|
| `SymTab.def/.mod` | clean |
| `QbeGen.def/.mod` | clean |
| `M2S.def/.mod` (Coco/R scanner) | 30 errors |
| `M2P.def/.mod` (Coco/R parser) | errors (mostly cascade) |
| `M2.mod` (driver) | needs `stdlib/strings` in the session |

## Remaining gaps (precisely identified)

1. **Procedure types** — unsupported. `GetCH = PROCEDURE (INT32):
   CHAR;`, procedure variables (`CurrentCh: GetCH;`), and the
   `Error: PROCEDURE (...)` callback in `M2S.def`. The main `M2S`
   blocker (`invalid Type` then cascade). **Step-9-sized**: function
   pointers + indirect calls in QBE.
2. **`INT32` alias resolution** in `M2S.mod` var/param types seen as
   "not a type name" — recheck once procedure types parse.
3. **Host `FileIO` open-file cap** `MaxFiles = BitSetSize` (16)
   blocks compiling all ~16 modules in one session (`Too many
   files`). Raise it, or use the self-hosted `FileIO`.

Then: cross-stage `FileIO` selection and `bootstrap/fixpoint.sh`
(Stage1 gm2 → Stage2 V3 → Stage3 V3, byte-identical `.ssa`).

## Resume commands

```sh
cd /home/eric/Projets/Projets-Modula2/MyWork/m2compiler-V3/compiler
./build.sh && ./run_tests.sh          # expect 105/105, no gm2 warnings

# SymTab/QbeGen gap check (needs a stub program, /tmp/gap.mod):
printf 'MODULE Gap;\nIMPORT SymTab;\nVAR ExitCode : INTEGER;\nBEGIN ExitCode := 0 END Gap.\n' > /tmp/gap.mod
./M2 ../stdlib/storage.def ../stdlib/storage.mod \
     ../runtime/syslib/SysShim.def ../runtime/syslib/SysShim.mod \
     ../runtime/syslib/FileIO.def ../runtime/syslib/FileIO.mod \
     src/SymTab.def src/SymTab.mod src/QbeGen.def src/QbeGen.mod \
     /tmp/gap.mod

# M2S (keep the session small — host FileIO caps at 16 open files):
./M2 ../stdlib/storage.def ../stdlib/storage.mod \
     ../runtime/syslib/SysShim.def ../runtime/syslib/SysShim.mod \
     ../runtime/syslib/FileIO.def ../runtime/syslib/FileIO.mod \
     src/M2S.def src/M2S.mod /tmp/gap.mod
```