# v3-corpus

Runs the **V3 compiler** (`compiler/M2`) over a corpus of standard
Modula-2 sources and reports compile coverage — unlike
`tools/topspeed-grammar`, which runs the *sidecar* grammar.

```sh
./corpus.sh [corpus-dir ...]
# default: gm2 testsuite pim/pass + iso/run/pass
```

Each source is copied into a scratch tree (so its `.LST` listing never
touches the corpus) and compiled on its own.  A file with **0 errors**
is a pass.  Failures are split into:

- **CRASH** — `M2` died (rc ≥ 128): a real compiler bug;
- **LIB** — the file imports a module outside V3's known stdlib set
  (gm2's `StrIO`/`NumberIO`/`STextIO`/…), so the `undeclared
  identifier`s are expected, not a language gap;
- **LANG** — otherwise: a genuine parse/semantic gap in V3.

A "pass" is syntactic+semantic cleanup, not a linkable image (many
testsuite files are DEFINITION/IMPLEMENTATION modules with no program;
V3 reports those as `Incorrect source` but with 0 errors).

An IMPLEMENTATION file is compiled together with its sibling
DEFINITION (same basename, `.def`/`.DEF`) when present, so a `.mod`
does not fail on its own interface.

Corpora used:
- gm2 testsuite `pim/pass` + `iso/run/pass`;
- the gm2 standard libraries, e.g.
  `$HOME/bin/Modula2/Gm2/lib/gcc/x86_64-pc-linux-gnu/16.0.1/m2/{m2pim,m2iso,m2log,m2cor,m2min}`.

Current baseline: `docs/summary_v3-corpus.md`.