Lemmings Paintball Decompilation

Work-in-progress reconstruction of 1996 Win32 LEMBALL.EXE, built with MSVC 4.20 and compared against original binary with reccmp.

Original executable reports LINK 3.00 and contains an incremental link table at 0x00401000 through 0x00403890; real code begins at 0x00406160. Current MSVC 4.20 build deliberately uses /INCREMENTAL:NO for function-level comparison. Whole-image parity remains separate work: resource section, CRT, and imports differ.

Decompilation workflow

Use one checkout and one editing agent at a time. Other agents may inspect Ghidra or suggest work, but do not edit or build concurrently.

Start with a shape-first batch:

1. Run candidate miner with --save-baseline to save current non-stub 100% address set and group unmatched real functions by normalized original instruction shape.
2. Prefer largest cluster with exact exemplar or simple compiler-owned C++ pattern.
3. Inspect every member in Ghidra, recover one parameterized C/C++ form, and implement all proven members.
4. Compare every member and run full JSON. Keep zero-loss exact gains, then continue next cluster.

This turns repeated constructors, destructors, scalar deletes, vtable restores, accessors, and small forwarding bodies into one compiler investigation plus many verified matches. Shape similarity is candidate generation, never proof: ABI, stack cleanup, offsets, constants, xrefs, and source ownership still need per-member confirmation.

.decomp-venv\Scripts\python.exe tools\find_decompilation_candidates.py `
  --save-baseline

After high-yield families are exhausted, use miner's singleton fallback. Ghidra inventory export validates all 2,077 ILT entries and excludes them.

Cron worker prompt

Copy this into next editing task:

Work autonomously on Lemmings Paintball decompilation project in
C:\Users\Simon\CLionProjects\lemball-decomp. Follow AGENTS.md.

Continue unfinished work. If none remains, refresh reccmp results when stale,
then run:
`.decomp-venv\Scripts\python.exe tools\find_decompilation_candidates.py --save-baseline`
Prioritize highest-yield proven shape cluster, inspect every member in Ghidra,
recover one minimal C/C++ template, and verify every member. After each full
reccmp run, run:
`.decomp-venv\Scripts\python.exe tools\find_decompilation_candidates.py --check-baseline`
Keep zero-loss gains.
Continue additional viable clusters; do not stop after one tiny function.
After batch candidates are exhausted, work first viable singleton fallback.

Run canonical checks, review all diffs, commit verified progress, push, and
leave clean worktree. Finish only after successful commit and push or
repository-wide blocker. Return one or two plain-English result sentences.

Setup

py -m venv .decomp-venv
.decomp-venv\Scripts\python.exe -m pip install -r requirements.txt

The canonical build installs a narrow reccmp 0.1.6 compatibility hook. For data comparison only, original pointers to verified E9 entries in the documented linker ILT are resolved to their real destinations.

Legal

Encrypted non-working original executable is included only for automated comparison. No game assets required for play are included. This unofficial preservation project is not affiliated with any rights holder.