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Author SHA1 Message Date
lane-w
2308b6edb9 lane W: SvSctOb variant factories; fix the four save_reader.py defects openly
Part 1 (notes side): findings/objects/svsctob-variants.md records the two maps
that are nowhere on the wire and were read out of the game -- EncID -> class
from a 23-entry dword jump table at 0x0052bf60 indexed by EncID-1 (0x0052bf00),
and xscn -> class from an exhaustive four-way _stricmp chain at 0x005a7050.
Twelve live EncIDs, four scenario names, and "indsys" =
Game::SVSOIndependentSystems whose Read and Write are both the shared `ret 4`
stub at 0x005f8ac0, so its empty frame is correct output rather than a
truncation. Also: SVSOSots::Read accepts NPCPlr and hastraps, which Write never
emits -- read-only backward compatibility, not a hole in the recovery. And a
correction to the recovery itself: SVSOCrowDefenders writes `dsys` INSIDE the
ndsys loop; layouts.json calls it a plain member and no save can settle it
because both counts are 0 everywhere. 13 addresses in ghidra/addresses.d/
lane-w.json; gen_addresses.py merges to 640 with no duplicate name.

Part 2: lane G found four defects in both readers and deliberately did not
patch the oracle mid-campaign. Fixed now, with tests, and byte-neutral.
  1. Game::SystemParams field 1 is a string, not an int (empty string == four
     zero bytes == int 0, so it round-tripped by luck).
  2. ObservedTech/ObservedWeapon odet is a bool, not an int (byte-safe only
     because a 4-char tag makes both items 12 bytes; 3 chars would not).
  3. SpeciesRatios nv is a count, not a field.
  4. ShipRecords srbd is a count, not a field -- and this one is behaviourally
     confirmed, not inferred: srbd takes 0, 1, 3 and 4 across the players and
     every non-zero count is followed by exactly srbd x 5 scalars.
Note that 3 and 4 were an ABSENCE in save_reader.py, not an error: ShipRecs and
civr were both A(..., "any"), so the fix had to add the shapes rather than
retype a field.

Byte-neutrality: every item's inflated offset is unchanged on all four saves
(38,933 / 39,843 / 40,300 / 35,771 offsets, sequences identical), so no item
boundary moved. state_checksum.py still reports coverage: PROVED on all four
with the same rebuilt byte counts. The /CreateParams and /Sim/players digests do
change, because they hash typed VALUES and two fixes change what a value is --
and the value-byte deltas balance exactly: odet items x 3 plus p1 items x 4.
--strict exit 0 on all four saves; tests 36 -> 48.

findings/objects/wire-schema-closeout.md carries the whole account, including
the proof that CD/TurnCommands_v5 cannot be typed without a save that has
issued orders.
2026-09-08 07:05:09 -04:00
alex
f965c8c769 lane S: std::string is 0x1c binary-wide; ObservedTech element fully mapped
Settles the 0x18-vs-0x1c contradiction lane X raised. 0x1c is right, everywhere,
and there is exactly one std::string instantiation in this binary:
_Bx@0, _Mysize@0x10, _Myres@0x14, _Alval@0x18.

ObservedTech+0x24 is that string's trailing empty-allocator word, not the
unaccounted data field it was read as. Three complete enumerations of the element
each skip it: ObservedTech::Write 0x00817cf0, the ctor 0x008562a0, and the copy
ctor inlined at 0x0079a184. Generalised with a new scanner, tools/strfootprint.py,
which recovers every (base, disp, tag) handed to the Mars::Stream string helpers:
65 std::string members off a non-stack base across every serializer in the exe,
ZERO with a sibling member inside the 0x1c span, and 51 of the 52 measurable
inter-member gaps exactly 0x1c. Corroborated by the vector<string> walk stride
(add esi,0x1c @0x00699c29), PostEvent's by-value strings at [ebp+8]/[ebp+0x24]
with RET 0x4c, and MoraleEvent 0x50 = name@0x34 + 0x1c.

Blast radius: zero recovered struct tables were wrong. Every string-bearing layout
already used 0x1c spans and 0x1c gaps -- ServerPlayer::pswd @0x2dc..0x2f7, the row
flagged for re-checking, included. Only prose carried the 0x18 number: the
loader-prototypes conventions line, the GlobalConst_ParseString prototype, and the
ObservedTech element table. struct-recovery S0 additionally had _Mysize/_Myres
transposed (size@0x14, res@0x18) while every table in the same file used the
correct offsets; fixed.

ObservedTech's four on-disk fields are now mapped rather than guessed, by reading
the serializer as lane X suggested: +0x04 uint16 otnF, +0x06 uint16 otnL, +0x08
bool odet (ONE BYTE, WriteBool), +0x0c std::string otch (0x1c), +0x28 int owith
= 0x2c exactly. That matches save_reader.py's on-disk order already. Game::
ObservedWeapon (0x00817bc0/0x00817b10) is the same element with tag owep.

Oracles unaffected and re-run: save_reader 36/36 and --strict exit 0 on all three
real saves; state_checksum 38 tests OK, coverage PROVED byte-for-byte on turn1 and
turn3. sots-engine wip/strings 32d3e36 syncs the header and corrects two stale
"unpinned" comments: clean_room_check OK, host ctest 33/33.

Standing rule this produced: never size a struct member from the offsets the code
touches. This build's STL puts the empty allocator LAST in both string (0x1c) and
vector (0x10), and an empty allocator is never loaded or stored, so a touch-scan
undercounts by exactly 4 every time. Size from an enumeration instead.
2026-09-08 05:09:33 -04:00
alex
436a51fa04 save-reader: real tag names (byte-confirmed), 36 tests, strict 3/3 2026-09-07 17:56:59 -04:00
alex
426df0232a verified: save_reader strict-clean on 3 real saves; all core layouts confirmed; SAVE_FORMAT confirmed 2026-09-07 16:39:41 -04:00
alex
2ea16f0036 ignore pycache 2026-09-07 15:55:37 -04:00
alex
15ecd22aa6 verify: Streamable save reader + writer stub + tests + SAVE_FORMAT 2026-09-07 15:55:27 -04:00