objects/layouts.json is a memory-layout projection: build() sorts fields by
off_abs (89 of 386 classes have offset order != write order) and merges
duplicate offsets into alt_tags, which is exactly the JewelsOfTheCrown
double-tag trap. Both losses are the substance of the on-disk format.
tools/streams.py is a second projection of the same recovery that keeps the
program order Lab.layout() already computes and the repeated tags, and drops
every memory fact — no off, size, sizeof, gaps or strides. The engine must read
and write the format, not inherit the original's ABI.
tools/gen_stream_schema.py emits sots-engine's include/generated/sots_stream_schema.h
under the same discipline as gen_addresses.py: generated, provenance header,
never hand-edited.
386 classes, 2042 wire items.
Every serializable class carries an enumeration of its own fields -- its
Write(Stream&), walking the members in order with a 4-char tag. This decodes
that idiom mechanically for the whole binary in 0.35 s.
Validation first (tools/serializers.py validate), against answers the campaign
already had before the tool existed:
A 305/307 field offsets+kinds exact across 17 classes, 0 WRONG, vs
struct-recovery.md 1-4 and observedtech-append.md
B sizeof from the container-stride divides: ObservedTech 0x2c, MoraleEvent
0x50, PlayerReport 0x30, DiplomacyStats 0x24 -- all matching
C 22 of save_reader.py's shapes, tag order identical (Sys 78 tags,
Player 104, CreateParams 25, Ship 22): 22 agree, 0 disagree
D Read/Write cross-check on every class: 437/437 field offsets agree
At scale: 386 classes with a Write, 1,682 member fields.
verified 87 (542 fields) | clean 77 (328) | unnamed 176 (471)
partial 31 (341) | empty 15
58 classes with a sizeof corroborated by a second line of evidence
(45 container stride, 13 enumeration meeting the embedding bound); the rest
report a lower bound and say so.
Four things each worth 10-170 classes: the RTTI class hierarchy descriptor as
the only honest "is this an IStreamable" test (a 3-slot vftable also matches
TacAISquadRule_* and the row parsers); mod=0 memory operands, which x86disp.py
cannot index and which hide every field at offset 0; the member->id pointer
idiom behind every handle field; and sub-writers, both base-class and private
(StrategyServer's six id lists live in FUN_00794cd0).
Failure classes are enumerated in the finding -- 176 anonymous-tag classes are
a hard limit on names but not on layout, and the other 64 are bounded
mechanical fixes. Two fields lost to a value assembled across a branch were
left unrecovered rather than patched with an unverifiable heuristic.
Write-back: 288 structures + 328 labels into Ghidra (0 failures), +201
addresses.json entries, header regenerated with tools/gen_addresses.py.
Note: ghidra/addresses.json also carries lane V's already-written live
confirmation text on ObservedTech_sizeof and ServerPlayer_off_ObservedTechs --
their edit, swept in only because we share the file.
