bin-table-diff

Binary Record Table Diff

Find the fixed-stride record tables compiled into a binary, extract them, and diff two builds record by record.

When to use

Software of a certain era compiles its content straight into the executable: song lists, level and difficulty tables, item stats, string catalogues. A function-level diff is blind to all of it — an added track or a rebalanced difficulty changes no code at all. If you are documenting what changed between two builds and only diffing code, you are missing whatever lives in these tables.

Pair it with diaphora-diff or bindiff: those tell you which functions changed, this tells you which content did.

Usage

rekit run bin-table-diff find    ./game-1.0                        # locate tables
rekit run bin-table-diff extract ./game-1.0 ./out                  # JSON + CSV
rekit run bin-table-diff diff    ./game-1.0 ./game-1.1 ./out       # record-level diff

How detection works, and what it can't know

A table is found by a signal that is hard to counterfeit: a run of records at a fixed stride where the same position in every record holds a pointer into the binary's own string data. Nothing about the layout is assumed — stride, extent, and column types all come from the bytes, so it works across eras and games whose structs differ.

Virtual addresses are translated through the binary's PT_LOAD headers rather than an assumed load base, so it is not tied to any one platform convention.

Offsets are anchor-relative. Where the pointer block sits inside the struct cannot be recovered from pointer validity alone — every candidate alignment describes the same bytes, so testing them proves nothing. The pointer block is therefore treated as column 0 and every column labelled relative to it. Extraction stays self-consistent and two builds diff correctly, because both are detected identically. Columns are named by their offset from that anchor (f00, f04, …), not by any inferred meaning. Pass --offset/--stride/--records when you know the true struct start and want struct-relative columns.