xenia-rs/crates/xenia-analysis/SCHEMA.md

# `xenia-analysis` schema reference

Authoritative documentation for the DuckDB tables and SQL views produced by
`xenia-rs dis --db sylpheed.db`. Track schema changes here alongside any
update to the `db_schema_golden` test fixture.

The base + disasm tables (`metadata`, `sections`, `imports`, `functions`,
`labels`, `instructions`, `xrefs`, opt-in `exec_trace` / `import_calls` /
`branch_trace`) are documented inline in `src/db.rs` doc comment. This file
collects layered analysis additions and forward-work notes.

---

## Layer M1 — `.pdata` boundary correction (landed)

### Schema additions
- `functions.pdata_validated BOOLEAN NOT NULL` — `true` when the row's
  `address` matches a `RUNTIME_FUNCTION.BeginAddress` from `.pdata`. Linker
  ground truth.
- `functions.pdata_length BIGINT NULL` — `function_length` (bytes) from the
  matching pdata entry; `NULL` when the row is prologue-only.
- New table `pdata_entries(begin_address BIGINT PRIMARY KEY, end_address
  BIGINT, function_length BIGINT, prolog_length BIGINT, flags BIGINT)` — every
  parsed `.pdata` `RUNTIME_FUNCTION` entry (raw, before any merge with
  prologue analysis).
- Index `idx_functions_pdata_validated` on `functions(pdata_validated)`.

### What this layer does
- Parses `.pdata` 8-byte `RUNTIME_FUNCTION` entries (PowerPC PE32 layout):
  word 0 `BeginAddress` (absolute VA), word 1 packed
  `{prolog_length:8, function_length:22, flags:2}`, both big-endian.
- Unions pdata `BeginAddress` values into the function-candidate set fed to
  the prologue walker, so functions our prologue heuristic missed still get
  rows.
- When pdata supplies a longer `function_length` than the prologue walk
  found, extends `end_address` to the pdata-implied end (catches mis-split
  where the walker stopped at an early `blr`).
- After the walker, performs a forward pass that trims `function.end` to the
  next start when they overlap (catches mis-merge where one row spanned two
  prologues — the audit-031 `sub_824D23B0` / `sub_824D29F0` case).

### What this layer does NOT do
- Does not adjust prolog-derived `frame_size` / `saved_gprs` from `.pdata`'s
  `prolog_length` field — those remain prologue-only inferences.
- Does not classify functions further than the existing `is_leaf` /
  `is_saverestore` columns. Class membership is M3.
- Does not detect functions whose entries are missing from BOTH `.pdata`
  and the bl-target scan (extremely rare; would require executable-byte
  linear sweep).

### Reference docs
- Microsoft PE32+ exception data spec for PowerPC RUNTIME_FUNCTION.
- xenia-canary `src/xenia/cpu/xex_module.cc:1570-1587` — canary's reference
  parser (extracts `BeginAddress` only; we additionally decode word 1).

### Validation queries
```sql
-- All pdata entries found
SELECT COUNT(*) FROM pdata_entries;            -- ~23073 for Sylpheed
-- Functions cross-validated against pdata
SELECT COUNT(*) FROM functions WHERE pdata_validated;
-- Functions detected ONLY by prologue (orphans of pdata)
SELECT COUNT(*) FROM functions WHERE NOT pdata_validated;
-- Pdata orphans NOT yet in functions (should be 0 after this layer)
SELECT COUNT(*) FROM pdata_entries p
LEFT JOIN functions f ON f.address = p.begin_address
WHERE f.address IS NULL;
-- Audit-031 mis-merge resolved: 0x824D29F0 should have its own row
SELECT name FROM functions WHERE address = 2186674160;  -- 0x824D29F0
```

---

## Layer M2 — MSVC C++ name demangler (landed)

### Schema additions
- New table `demangled_names(address BIGINT NULL, mangled VARCHAR NOT NULL,
  raw_demangled VARCHAR NOT NULL, namespace_path VARCHAR NULL,
  class_name VARCHAR NULL, method_name VARCHAR NULL,
  params_signature VARCHAR NULL)`.
- Indices on `address`, `class_name`, `method_name`.

### What this layer does
- Wraps `msvc_demangler::demangle` (a Rust port of LLVM's
  `MicrosoftDemangle.cpp`) and splits the formatted output into structured
  fields via a heuristic top-level parser (handles templates and nested parens
  correctly).
- Populates `demangled_names` from any label whose name starts with `?` plus
  any import name that happens to be mangled (defensive — typical kernel
  imports use C names).

### What this layer does NOT do
- Does not parse the AST returned by `msvc_demangler::parse` — uses the formatted
  string and a heuristic split. Adequate for typical class member functions
  and RTTI strings; exotic template / lambda forms still get `raw_demangled`
  populated but may have NULL structured fields.
- Does not yet ingest RTTI strings discovered in `.rdata` — that's M3's job;
  M3 will append rows to this table at the addresses where it finds RTTI
  TypeDescriptors.

### Reference docs
- `msvc-demangler` crate (`https://docs.rs/msvc-demangler/0.11`).
- LLVM `MicrosoftDemangle.cpp` (the parser this crate ports).

## Layer M3 — Vtable + RTTI detection (landed)

### Schema additions
- `vtables(address PK, length, col_address NULL, class_name, rtti_present,
  base_classes_json NULL)` — every detected static vtable.
- `methods(vtable_address, slot, function_address, mangled_name NULL,
  demangled_name NULL, PRIMARY KEY (vtable_address, slot))` — one row per
  method slot.
- `classes(name PK, vtable_address, rtti_present, base_classes_json NULL)` —
  deduped by class name (first-detected vtable wins).
- Indices: `methods.function_address`, `classes.rtti_present`.

### What this layer does
- Walks `.rdata` and `.data` looking for runs of ≥3 consecutive 4-byte BE
  values where each value is a known function start (from M1's corrected
  `functions` table). Single-2-method vtables are intentionally rejected to
  control false-positive rate.
- Attempts the MSVC RTTI walk `vtable[-1] → CompleteObjectLocator → TypeDescriptor`
  for each candidate. When successful, the demangled `class ClassName`
  string fills `class_name` and a best-effort
  `RTTIClassHierarchyDescriptor` walk fills `base_classes_json` (JSON array
  of base class names).
- Falls back to `ANON_Class_<8-hex>` keyed by FNV-1a hash of the sorted
  method-PC tuple when RTTI is absent (typical for shipped game binaries).
  Identical vtables across the binary (multiple instances) collapse to the
  same anonymous name.

### What this layer does NOT do
- Vtables built at runtime in heap-allocated memory (e.g. by ctors copying
  static templates) are out of scope — only static `.rdata`/`.data` content.
- Multiple-inheritance "extra" vftables (one per base subobject) are detected
  as independent vtables with no link between them.
- Inheritance-tree walking beyond `RTTIClassHierarchyDescriptor`'s direct
  base list is not attempted.

### Reference docs
- openrce.org "Reversing Microsoft Visual C++" — RTTI layout articles
  (CompleteObjectLocator at vtable[-1]; TypeDescriptor at COL+0xC; mangled
  name at TD+0x8).

## Layer M4 — Class-aware probe targeting (landed)

CLI extension only — no schema changes. The probe-token grammar adds three
symbolic forms on top of the existing `0xADDR` literal:

- `Class::method` — joins `classes` × `methods` × `demangled_names` to find
  every PC whose vtable belongs to that class and whose demangled
  `method_name` matches.
- `Class::*` — joins `classes` × `methods` to find every method PC of that
  class.
- `function_name` — falls back to `functions.name` lookup for free functions
  / saverestore stubs / labels.

Numeric tokens never touch the DB (preserves zero-IO fast path; lockstep
digest unaffected). Symbolic tokens require the DuckDB at `--probe-db PATH`
or `XENIA_PROBE_DB`; default is `sylpheed.db` next to the .iso when present.

Resolution happens BEFORE guest exec begins, so it cannot affect the
lockstep digest.

See `crates/xenia-analysis/src/lookup.rs`.

---

## Layer M5 — Indirect-dispatch reachability (landed)

### Schema additions
- New value `'ind_call'` in the `xrefs.kind` set.
- New SQL view `v_indirect_reachability_from_entry` — strict superset of
  `v_reachability_from_entry`, taking `ind_call` edges in the BFS.

### What this layer does
- Walks each `FuncAnalysis.functions` entry with a per-basic-block register
  tracker. Recognises the canonical static-vtable pattern:
  `lis+addi → lwz off(rA) → mtctr → bcctrl`, where `rA` ends up holding a
  known vtable's start address from M3.
- Honours the PowerPC ABI: `bl`-style calls (op 18 / 16 with LK=1) clobber
  volatile r0..r12 + ctr but preserve non-volatile r13..r31, so a vtable
  pointer parked in r30/r31 before a call survives.
- Treats every M3 `loc_*` label as a basic-block boundary (kills register
  state) so jump-IN paths cannot induce false positives.

### What this layer does NOT do (and observed impact)
- Vtable pointer loaded from a `this`-pointer field
  (`lwz r_vt, off(rA)` where `rA = this`) — by far the dominant pattern in
  real C++ — is unresolvable without alias / points-to analysis.
- On Sylpheed: the layer detects 0 edges. The binary's 1,001 lis+addi
  references into vtables are mostly constructor-side **vptr writes**
  (`stw rVtable, vptr_offset(this)`), not direct dispatches. The renderer
  hunt's audit-009 cluster therefore needs a future M5.5 with `this`-flow
  tracking before this layer surfaces it.

### Reference docs
- IBM PowerPC ABI: register-save convention (volatile r0..r12 + ctr,
  non-volatile r13..r31).

## Layer M7 — String / constant-pool detection (landed)

### Schema additions
- New table `strings(address PK, encoding, length, content)`.
- Index `idx_strings_encoding`.

### What this layer does
- Scans `.rdata` for runs of length ≥ 6 of printable ASCII bytes followed by
  a NUL terminator.
- Scans `.rdata` for UTF-16LE runs of length ≥ 6 code units (printable-ASCII
  basic plane only) followed by a u16 NUL terminator.
- Cross-reference is implicit: existing `xrefs.kind='ref'` rows whose
  `target` falls in `strings.address`'s exact match set name the referencing
  PCs. SQL: `SELECT s.content, x.source FROM xrefs x JOIN strings s
  ON s.address = x.target WHERE x.kind='ref'`.

### What this layer does NOT do
- No UTF-8 multibyte / non-ASCII basic plane in either encoding.
- No `.data` scan (read-only-section bias).
- No multi-byte CJK encodings — Japanese text in localised builds may be
  represented in shift_jis / utf-8 with non-printable bytes that this
  scanner skips.

### Sylpheed yield
- 6,311 ASCII strings (including full embedded HLSL shader source).
- 0 UTF-16LE strings (binary uses ASCII / native CJK encoding).
- 9,132 lis+addi sites cross-reference into the detected strings — names
  the source PCs that reference each string.

## Forward work (M6, M8–M12, not yet landed)

- **M6** — extended `xrefs.kind='write'` for indexed/byte-reverse/multiword/VMX/DCBZ/atomic stores with `addr_mode` column.
- **M8** — dispatch-table heuristics beyond vtables (e.g. function-pointer arrays in `.data`).
- **M9** — `__CxxFrameHandler` exception scope-table parsing.
- **M10** — `.tls` section / TLS slot tracking.
- **M11** — `__xc_a` / `__xc_z` static-initializer driver detection.
- **M12** — comparative-PC-trace mode for canary diff (runtime side, not analyzer).