acdream/tools/pdb-extract/README.md
Erik 69d884a3d6 tools(pdb-extract): #8 PDB -> symbols.json + types.json sidecar
Pure-Python MSF 7.00 PDB extractor (no deps, stdlib only). Reads
refs/acclient.pdb directly:
  - DBI stream (3) -> symbol record stream index + section header
    stream index
  - Section headers stream (9) -> per-segment image VA bases
  - Symbol record stream (8) -> S_PUB32 records with image VAs
  - TPI stream (2) -> LF_CLASS / LF_STRUCTURE named records (not
    forward-declared), with size leaf + name

Includes a best-effort MSVC C++ demangler so symbols.json is
grep-friendly:
  ?EnchantAttribute@CEnchantmentRegistry@@QBEHKAAK@Z
  -> CEnchantmentRegistry::EnchantAttribute

Both demangled `name` + raw `mangled` emitted per entry so callers
can choose. Operator overloads, vtables, and other special forms
where a partial demangle would be misleading are kept mangled.

Outputs committed to docs/research/named-retail/:
  - symbols.json (2.9 MB) — 18,366 named public function symbols
  - types.json (506 KB) — 5,371 unique named class/struct records

Spot check (matches discovery agent's earlier finding):
  CEnchantmentRegistry::EnchantAttribute -> 0x00594570 ✓

Updated docs/research/acclient_function_map.md header preamble to
direct readers at the new symbols.json as the authoritative name
source; the hand-curated table stays as the cross-port (ACE/ACME)
index. Several addresses there are wrong vs the PDB and will be
swept in the issue #9 close (Phase E).

Closes #8 (filed in Phase D's commit). Foundation for the address
sweep + name-driven workflows from here on.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-25 17:31:52 +02:00

117 lines
4.1 KiB
Markdown

# pdb-extract — pure-Python MSF 7.00 PDB extractor
Reads `refs/acclient.pdb` (Sept 2013 EoR build, 28 MB) and writes two
grep-friendly JSON sidecars to `docs/research/named-retail/`:
- **`symbols.json`** — 18,366 named public function symbols from the
PDB's S_PUB32 records. Each entry has `address` (image VA), `name`
(MSVC-demangled `Class::Method` form), and `mangled` (raw C++ ABI
symbol for callers that need exact mangling).
- **`types.json`** — 5,371 unique named struct/class type records from
the TPI stream (LF_CLASS / LF_STRUCTURE). Each entry has `name`,
`size` (bytes), and `kind` (`class` or `struct`).
## Usage
```powershell
py tools\pdb-extract\pdb_extract.py refs\acclient.pdb
```
Runs in <1 second. No external dependencies uses Python stdlib only.
## Schema
`symbols.json`:
```json
[
{
"address": "0x00594570",
"name": "CEnchantmentRegistry::EnchantAttribute",
"mangled": "?EnchantAttribute@CEnchantmentRegistry@@QBEHKAAK@Z"
},
...
]
```
`types.json`:
```json
[
{
"name": "CEnchantmentRegistry",
"size": 32,
"kind": "class"
},
...
]
```
## Workflow integration
The committed JSON sidecars are the named-retail counterpart to the
`acclient_2013_pseudo_c.txt` text dump. Pseudo-C is for reading
function bodies; `symbols.json` is for programmatic lookups. Use
`jq` to query:
```bash
# Find a function by exact name
cat docs/research/named-retail/symbols.json | jq '.[] | select(.name == "CEnchantmentRegistry::EnchantAttribute")'
# Find all functions on a class
cat docs/research/named-retail/symbols.json | jq '.[] | select(.name | startswith("CACQualities::"))'
# Reverse lookup by address (e.g. mid-body fix-up)
cat docs/research/named-retail/symbols.json | jq '.[] | select(.address == "0x00594570")'
# Find a type by name
cat docs/research/named-retail/types.json | jq '.[] | select(.name == "Enchantment")'
```
## Address mapping caveat
The PDB is from the Sept 2013 EoR build. Addresses generally match the
binary used to produce our `docs/research/decompiled/` Ghidra chunks
within ~0xC00 bytes (different build runs of the same source revision).
**When using `symbols.json` to correct entries in
`acclient_function_map.md`, match by name, not by raw address.**
## Implementation notes
The script is a self-contained MSF 7.00 reader. References used:
- LLVM PDB documentation (https://llvm.org/docs/PDB/) file format spec
- Microsoft `pdbparse` (community) implementation cross-check
Streams consumed:
- **3 (DBI)** parses the header to extract the symbol-record stream
index + the optional debug-header sub-stream's section-headers index.
- **9 (section headers)** parses `IMAGE_SECTION_HEADER` entries to
build a section-base table for VA computation.
- **8 (sym record stream)** iterates records, picks `S_PUB32` with
the `PUBSYM_FLAG_CODE` bit set, computes `VA = section_base + offset`.
- **2 (TPI)** iterates type records, picks `LF_CLASS` / `LF_STRUCTURE`
that aren't forward-declared, parses size leaf + name.
The MSVC name demangler (`_demangle`) is best-effort: handles the
common `?Method@Class@Outer@@<sig>` patterns, constructors (`??0`),
and destructors (`??1`). Returns the mangled string unchanged for
operator overloads (`??2`, `??3`), vtables (`??_`), and other forms
where a partial demangle would be misleading. Both `name` (demangled)
and `mangled` (raw) are emitted in `symbols.json` so consumers can
choose.
## When to regenerate
- Whenever `refs/acclient.pdb` is updated (rare).
- Whenever `pdb_extract.py` is changed (e.g. better demangler, more
type info recovery).
The output JSONs are committed because they're stable + small (~3 MB
combined) and grep-faster than re-parsing the PDB on every session.
## Future work (out of scope here)
The current `types.json` only carries name + size. A more ambitious
version would walk LF_FIELDLIST records to recover field names +
offsets + types giving us a JSON-encoded `acclient.h`. Not done yet
because `acclient.h` already exists committed at
`docs/research/named-retail/acclient.h`. Consider this if a future
panel needs offsetof() at runtime.