Method dispatch axis: map id -> body via Runner::run switch

Recovers how a script method id maps to its implementation, the foundation for
body-level normalisation. Each CMC_*_Runner::run is a switch(id) (vtable slot 17);
every case is the method body — inline (MSVC6) or a tail-call to a separate
show()/load() (MSVC8). The extractor parses the jump table at the disassembly
level (Ghidra's decompiler jump-table recovery silently dropped the big runners),
fingerprints each case by its ordered CALL anchors (Class::method / vtbl+0xNN),
and expands thin wrappers one level so MSVC8 lines up with MSVC6.

Validated on the golden pair: Animo SHOW..RESUME (id 1-4) yield identical leaves
(getAnimo + vtbl+0xa0/0xa4/0x4c/0x50) across both compilers. Coverage 30/32
runners; Piklib 475 / BlooMoo 619 dispatch rows.

- extract_engine_surface.py: extract_method_dispatch (schema_version -> 4)
- snapshots regenerated with the method_dispatch axis
- ams: Snapshot.method_dispatch; diff axis keyed (owner,id) on [impl,calls] with
  method-name join; render METHOD BODIES section; cli --only dispatch; owner filter
- UI: "Ciała metod" diff axis + browse tab
- tests: body-change unit + cross-compiler vtbl assertion -> 29/29

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

README.md

@@ -35,6 +35,7 @@ działa na MSVC6 (Piklib) i MSVC8 (BlooMoo) mimo różnego kodu wynikowego.
 | Eventy | `CMC_*::getBehavioursList`: lista literałów `CXString` | ✅ (lista per klasa, bez dziedziczenia) |
 | Pola (skryptowe) | ctory `CMC_*`: literały czytane przez `CMElement::getProperty<T>Value` → nazwa + typ pola (FPS, PRELOAD, VISIBLE…) | ✅ (+ `field_inheritance`) |
 | Layout C++ (bonus) | ctory `CMC_*`: store'y `this+offset` przez P-code (rozmyte, `is_vtable`) | ✅ pod `struct_layout` |
+| Ciała metod | `CMC_*_Runner::run`: `switch(id)` (vtable slot 17) → per case kotwice CALL (`Klasa::metoda` / `vtbl+0xNN`), rozwinięcie wrapperów | ✅ pod `method_dispatch` (id→`impl_addr`+`calls`) |
 
 ## Uruchomienie ekstraktora
 
@@ -101,10 +102,13 @@ czysty Python. Snapshot dostaje doklejony blok `binary.acquisition` (źródło,
 
 ```bash
 python -m ams OLD.snapshot.json NEW.snapshot.json [--owner CMC_Animo] \
-    [--only types,methods,events,fields,layout] [--json]
+    [--only types,methods,events,fields,layout,dispatch] [--json]
 ```
-Porównuje dwa snapshoty po 4 osiach (added/removed/changed) + wykrywa metody przeniesione
-w hierarchii. Oś `struct_layout` jest sensowna tylko między wersjami tego samego kompilatora.
+Porównuje dwa snapshoty po osiach (added/removed/changed) + wykrywa metody przeniesione
+w hierarchii. Oś `dispatch` (ciała metod, klucz `owner`+`id`) diffuje fingerprint wywołań
+każdej metody — wykrywa **zmiany ciała** między wersjami; jak `struct_layout`, najczystsza
+między wersjami tego samego kompilatora (cross-compiler proste metody i tak się zgadzają,
+np. Animo `SHOW`→`vtbl+0xa0` na MSVC6 i MSVC8).
 
 ## Backend (FastAPI + katalog)
 

ams/api/static/app.js

@@ -1,6 +1,6 @@
 "use strict";
 
-const state = { games: [], snaps: [], byId: {}, a: null, b: null, jobStatus: {}, axes: { types: true, methods: true, events: true, fields: true, layout: false } };
+const state = { games: [], snaps: [], byId: {}, a: null, b: null, jobStatus: {}, axes: { types: true, methods: true, events: true, fields: true, layout: false, dispatch: false } };
 
 // tiny DOM helper
 function el(tag, props, ...kids) {
@@ -39,6 +39,9 @@ const AXES = [
   { key: "struct_layout", uikey: "layout", title: "Layout C++ (bonus)",
     fmt: (x) => `${x.owner} @${hex(x.offset)} size ${x.size}${x.is_vtable ? " vtable" : ""}`,
     name: (x) => `${x.owner}@${x.offset}` },
+  { key: "method_dispatch", uikey: "dispatch", title: "Ciała metod",
+    fmt: (m) => `${m.owner} · ${m.name || ("id " + m.id)}${m.impl ? " → " + m.impl : ""}  [${(m.calls || []).length} calls]`,
+    name: (m) => `${m.owner}.${m.name || m.id}` },
 ];
 const hex = (n) => "0x" + Number(n).toString(16);
 
@@ -238,7 +241,10 @@ function axisCard(ax, block) {
   for (const it of sortByName(block.added)) body.append(el("div", { class: "row r-add" }, ax.fmt(it)));
   for (const it of sortByName(block.removed)) body.append(el("div", { class: "row r-del" }, ax.fmt(it)));
   for (const ch of block.changed.slice().sort((x, y) => ax.name(x.item).localeCompare(ax.name(y.item)))) {
-    const deltas = Object.entries(ch.changes).map(([f, v]) => `${f}: ${v[0]} → ${v[1]}`).join(", ");
+    const deltas = Object.entries(ch.changes).map(([f, v]) =>
+      (Array.isArray(v[0]) || Array.isArray(v[1]))
+        ? `${f}: ${(v[0] || []).length} → ${(v[1] || []).length}`
+        : `${f}: ${v[0]} → ${v[1]}`).join(", ");
     body.append(el("div", { class: "row r-chg" }, ax.name(ch.item), "  ", el("span", { class: "delta" }, deltas)));
   }
   return el("details", { class: "axis", open: true },
@@ -270,6 +276,7 @@ async function browse(id) {
     ["Metody", (d.methods || []).map((m) => `${m.owner} · ${m.name} (id ${m.id})`)],
     ["Eventy", (d.events || []).map((e) => `${e.owner} · ${e.name}`)],
     ["Pola", (d.fields || []).map((f) => `${f.owner} · ${f.name} : ${f.type}`)],
+    ["Ciała", (d.method_dispatch || []).map((m) => `${m.owner} · id ${m.id}${m.impl ? " → " + m.impl : ""}  [${(m.calls || []).join("  ")}]`)],
   ];
   out.innerHTML = "";
   out.append(el("div", { class: "diff-head" }, "Przegląd: ", el("b", {}, `${snap.binary_name} [${snap.engine}/${snap.compiler}]`)));

ams/cli.py

@@ -13,7 +13,7 @@ from .diff import compute_diff, filter_by_owner
 from .render import render_text
 from .snapshot import Snapshot
 
-_AXES = ["types", "methods", "events", "fields", "layout"]
+_AXES = ["types", "methods", "events", "fields", "layout", "dispatch"]
 
 
 def main(argv: list[str] | None = None) -> int:

ams/diff.py

@@ -69,6 +69,22 @@ def _detect_method_moves(old_m: list[Item], new_m: list[Item]) -> list[Item]:
     return moves
 
 
+def _dispatch_key(x: Item) -> Hashable:
+    return (x["owner"], x["id"])
+
+
+def _dispatch_with_names(snap: Snapshot) -> list[Item]:
+    """Attach the method name (from the methods axis, joined on owner+id) to each dispatch row,
+    so a body-level diff reads as 'SHOW body changed' rather than 'CMC_Animo id 1 changed'."""
+    name_by = {(m["owner"], m.get("id")): m["name"] for m in snap.methods}
+    out = []
+    for r in snap.method_dispatch:
+        rr = dict(r)
+        rr["name"] = name_by.get((r["owner"], r["id"]))
+        out.append(rr)
+    return out
+
+
 def compute_diff(old: Snapshot, new: Snapshot) -> dict[str, Any]:
     return {
         "binary": {"from": old.binary, "to": new.binary},
@@ -78,6 +94,8 @@ def compute_diff(old: Snapshot, new: Snapshot) -> dict[str, Any]:
         "fields": keyed_diff(old.fields, new.fields, _owner_name_key, ["type"]),
         "struct_layout": keyed_diff(old.struct_layout, new.struct_layout, _layout_key,
                                     ["size", "is_vtable"]),
+        "method_dispatch": keyed_diff(_dispatch_with_names(old), _dispatch_with_names(new),
+                                      _dispatch_key, ["impl", "calls"]),
         "method_inheritance": keyed_diff(old.method_inheritance, new.method_inheritance,
                                          lambda x: x["runner"], ["base_runner"]),
         "field_inheritance": keyed_diff(old.field_inheritance, new.field_inheritance,
@@ -90,7 +108,7 @@ def compute_diff(old: Snapshot, new: Snapshot) -> dict[str, Any]:
 def _item_owner(axis: str, item: Item) -> str | None:
     if axis == "types":
         return item.get("cpp_class")
-    if axis in ("methods", "events", "fields", "struct_layout"):
+    if axis in ("methods", "events", "fields", "struct_layout", "method_dispatch"):
         return item.get("owner")
     if axis == "method_inheritance":
         return item.get("runner")

ams/render.py

@@ -78,6 +78,40 @@ def _section_owned(out: list[str], title: str, block: dict, fmt: Callable[[dict]
                 name_of(it), _fmt_changes(change_by_id[id(it)]["changes"])))
 
 
+def _dispatch_name(r: dict) -> str:
+    return r.get("name") or "id {0}".format(r.get("id"))
+
+
+def _section_dispatch(out: list[str], block: dict) -> None:
+    """Method-body fingerprints (per owner+id). `calls` deltas are summarised by length so the
+    line stays readable; the full anchor lists live in the JSON."""
+    out.append("")
+    out.append("{0:<16} {1}".format("METHOD BODIES", _counts(block)))
+    owner_of = lambda r: r["owner"]
+    added = _group_by(block["added"], owner_of)
+    removed = _group_by(block["removed"], owner_of)
+    changed = _group_by([c["item"] for c in block["changed"]], owner_of)
+    change_by_id = {id(c["item"]): c for c in block["changed"]}
+    for owner in sorted(set(added) | set(removed) | set(changed)):
+        out.append("  {0}".format(owner))
+        for it in sorted(added.get(owner, []), key=_dispatch_name):
+            out.append("    + {0}".format(_dispatch_name(it)))
+        for it in sorted(removed.get(owner, []), key=_dispatch_name):
+            out.append("    - {0}".format(_dispatch_name(it)))
+        for it in sorted(changed.get(owner, []), key=_dispatch_name):
+            ch = change_by_id[id(it)]["changes"]
+            bits = []
+            if "impl" in ch:
+                bits.append("impl {0} -> {1}".format(ch["impl"][0], ch["impl"][1]))
+            if "calls" in ch:
+                a, b = ch["calls"]
+                bits.append("calls {0} -> {1}".format(len(a or []), len(b or [])))
+            out.append("    ~ {0:<22} {1}".format(_dispatch_name(it), "; ".join(bits)))
+
+
+_EMPTY = {"added": [], "removed": [], "changed": []}
+
+
 def _is_empty(block: dict) -> bool:
     return not (block["added"] or block["removed"] or block["changed"])
 
@@ -107,6 +141,8 @@ def render_text(diff: dict[str, Any], only: set[str] | None = None) -> str:
     if want("layout") and not _is_empty(diff["struct_layout"]):
         _section_owned(out, "STRUCT LAYOUT", diff["struct_layout"], _fmt_layout,
                        lambda x: x["owner"], lambda x: "@{0:#x}".format(x["offset"]))
+    if want("dispatch") and not _is_empty(diff.get("method_dispatch", _EMPTY)):
+        _section_dispatch(out, diff["method_dispatch"])
     if want("methods") and diff["moved_methods"]:
         out.append("")
         out.append("MOVED METHODS    {0}".format(len(diff["moved_methods"])))
@@ -114,7 +150,8 @@ def render_text(diff: dict[str, Any], only: set[str] | None = None) -> str:
             out.append("  {0}: {1} -> {2}".format(
                 m["name"], ",".join(m["from_owners"]), ",".join(m["to_owners"])))
 
-    if all(_is_empty(diff[a]) for a in ("types", "methods", "events", "fields", "struct_layout")):
+    if all(_is_empty(diff.get(a, _EMPTY))
+           for a in ("types", "methods", "events", "fields", "struct_layout", "method_dispatch")):
         out.append("")
         out.append("(no differences)")
     return "\n".join(out)

ams/snapshot.py

@@ -43,6 +43,10 @@ class Snapshot:
     def struct_layout(self) -> list[dict]:
         return self.raw.get("struct_layout", [])
 
+    @property
+    def method_dispatch(self) -> list[dict]:
+        return self.raw.get("method_dispatch", [])
+
     @property
     def method_inheritance(self) -> list[dict]:
         return self.raw.get("method_inheritance", [])

ghidra_scripts/extract_engine_surface.py

@@ -314,6 +314,222 @@ def extract_methods(program):
     return methods, inheritance
 
 
+_VTBL_OFF = re.compile(r"\[\w+ \+ (0x[0-9a-fA-F]+)\]")
+_MEM_OFF = re.compile(r"\[\w+ \+ (0x[0-9a-fA-F]+)\]")
+
+
+def _is_generic_name(name):
+    """A compiler-assigned placeholder, not a real symbol."""
+    return (not name) or name.startswith("FUN_") or name.startswith("thunk_") or name.startswith("LAB_")
+
+
+def _qualified(f):
+    if f is None:
+        return None
+    ns = f.getParentNamespace()
+    nm = f.getName()
+    return (ns.getName() + "::" + nm) if (ns is not None and ns.getName() != "Global") else nm
+
+
+def _call_anchor(program, instr):
+    """A normalisable, compiler-tolerant fingerprint of one CALL inside a switch case.
+
+    Direct call -> "Namespace::name". On MSVC8 the symbol sits on the ILT *stub* while the body
+    is an unnamed FUN_, so we keep the stub's name and only fall back to the thunk-resolved body
+    when the direct name is itself a placeholder. Indirect virtual call -> "vtbl+0xNN" from the
+    displacement, which abstracts away the register holding `this`."""
+    cf = call_target(program, instr)
+    if cf is not None:
+        if not _is_generic_name(cf.getName()):
+            return _qualified(cf)
+        resolved = resolve_thunk(cf)
+        if resolved is not None and not _is_generic_name(resolved.getName()):
+            return _qualified(resolved)
+        return _qualified(cf)
+    m = _VTBL_OFF.search(instr.toString())
+    if m is not None:
+        return "vtbl+" + m.group(1)
+    return None
+
+
+def _walk_calls(program, start_addr, stops, limit=80):
+    """Walk a straight-line block from `start_addr`, returning (anchors, funcs):
+
+    * `anchors` - ordered CALL fingerprints (see `_call_anchor`), additionally recovering the
+      `MOV reg,[base+0xNN]` / `CALL reg` virtual-call idiom (MSVC8) as `vtbl+0xNN`, so it matches
+      the `CALL [reg+0xNN]` form (MSVC6).
+    * `funcs` - the (anchor, entry) of each *direct* call to a real function, used to detect a
+      thin wrapper case that just forwards to a named/unnamed submethod.
+
+    Stops at a RET, an unconditional jump, a `stops` address, or after `limit` instructions."""
+    listing = program.getListing()
+    instr = listing.getInstructionAt(start_addr)
+    anchors = []
+    funcs = []
+    regoff = {}  # register -> vtable offset most recently loaded into it
+    n = 0
+    while instr is not None and n < limit:
+        if n > 0 and instr.getAddress() in stops:
+            break
+        n += 1
+        mn = instr.getMnemonicString()
+        if mn == "MOV" and instr.getNumOperands() >= 2:
+            dst = instr.getDefaultOperandRepresentation(0)
+            m = _MEM_OFF.search(instr.toString())
+            if m is not None:
+                regoff[dst] = m.group(1)
+            else:
+                regoff.pop(dst, None)
+        elif mn == "CALL":
+            a = _call_anchor(program, instr)
+            if a is None:  # CALL reg -> use the offset last loaded into that register
+                op0 = instr.getDefaultOperandRepresentation(0)
+                if op0 in regoff:
+                    a = "vtbl+" + regoff[op0]
+            if a is not None:
+                anchors.append(a)
+                cf = call_target(program, instr)
+                if cf is not None:
+                    body = resolve_thunk(cf)
+                    if body is not None:
+                        funcs.append((a, body.getEntryPoint()))
+        ft = instr.getFlowType()
+        if ft.isTerminal() or (ft.isJump() and not ft.isConditional()):
+            break
+        instr = instr.getNext()
+    return anchors, funcs
+
+
+_SWITCH_JMP = re.compile(r"\[(\w+)\*0x4 \+ (0x[0-9a-fA-F]+)\]")
+_LEA_DISP = re.compile(r"\[\w+ \+ (-?0x[0-9a-fA-F]+)\]")
+
+
+def _lea_disp(instr):
+    """Signed displacement of a `LEA reg,[base + disp]`, parsed from text when getScalar misses."""
+    m = _LEA_DISP.search(instr.toString())
+    return int(m.group(1), 16) if m is not None else None
+
+
+def _parse_switch(program, func):
+    """Recover the dense jump-table switch of a `run` function at the disassembly level
+    (decompiler-independent, so it survives the big inline-heavy runners). Both MSVC6 and
+    MSVC8 emit the same shape:
+
+        LEA idx,[reg - base] ; CMP idx, range ; JA default ; JMP [idx*4 + TABLE]
+
+    Returns {table, base, count} or None. `id = table_index + base`; `count = range + 1`."""
+    listing = program.getListing()
+    instrs = []
+    it = listing.getInstructions(func.getBody(), True)
+    while it.hasNext():
+        instrs.append(it.next())
+
+    idx_reg = table = jmp_addr = None
+    for instr in instrs:
+        if instr.getMnemonicString() == "JMP" and instr.getFlowType().isComputed():
+            m = _SWITCH_JMP.search(instr.toString())
+            if m is not None:
+                idx_reg = m.group(1)
+                space = program.getAddressFactory().getDefaultAddressSpace()
+                table = space.getAddress(int(m.group(2), 16))
+                jmp_addr = instr.getAddress()
+            break
+    if table is None:
+        return None
+
+    base = 0
+    count = None
+    for instr in instrs:
+        if instr.getAddress().equals(jmp_addr):
+            break
+        if instr.getNumOperands() == 0 or instr.getDefaultOperandRepresentation(0) != idx_reg:
+            continue
+        mn = instr.getMnemonicString()
+        s = instr.getScalar(1)
+        if mn == "CMP" and s is not None:
+            count = int(s.getValue()) + 1
+        elif mn == "LEA":                       # LEA idx,[reg - k] -> id = index + k
+            disp = int(s.getValue()) if s is not None else _lea_disp(instr)
+            if disp is not None:
+                base = -disp
+        elif mn == "SUB" and s is not None:
+            base = int(s.getValue())
+        elif mn == "ADD" and s is not None:
+            base = -int(s.getValue())
+        elif mn == "DEC":
+            base = 1
+    return {"table": table, "base": base, "count": count}
+
+
+def extract_method_dispatch(program):
+    """For each CMC_*_Runner::run, recover how method ids map to their implementation.
+
+    `run(int id, ...)` is a `switch(id)` (vtable slot 17, overridden per runner) whose every
+    `case id:` is the method body - either a tail-call to a named submethod (BlooMoo/MSVC8
+    keeps show()/load()/... as separate functions) or inline code whose leaves are virtual
+    calls on the wrapped object (Piklib/MSVC6). We fingerprint each case by its ordered CALL
+    anchors, so a later pass can diff method *bodies* by (owner, id). Join names via `methods`."""
+    fm = program.getFunctionManager()
+    out = []
+    it = fm.getFunctions(True)
+    while it.hasNext():
+        f = it.next()
+        if f.getName() != "run":
+            continue
+        ns = f.getParentNamespace()
+        runner = ns.getName() if ns is not None else "?"
+        if not runner.endswith("_Runner"):
+            continue
+        try:
+            out.extend(_dispatch_from_run(program, f, _owner_from_runner(runner), runner))
+        except Exception as e:  # one malformed runner shouldn't sink the whole axis
+            print("[!] method_dispatch %s: %s" % (runner, e))
+    return out
+
+
+def _dispatch_from_run(program, run_func, owner, runner):
+    run_func = resolve_thunk(run_func)
+    sw = _parse_switch(program, run_func)
+    if sw is None:
+        return []
+    count = sw["count"]
+    if count is None or count < 1 or count > 4096:
+        return []
+
+    mem = program.getMemory()
+    space = program.getAddressFactory().getDefaultAddressSpace()
+    targets = []
+    for i in range(count):
+        try:
+            val = mem.getInt(sw["table"].add(i * 4)) & 0xffffffff
+        except Exception:
+            break
+        targets.append(space.getAddress(val))
+
+    stops = set(targets)
+    rows = []
+    for i in range(len(targets)):
+        anchors, funcs = _walk_calls(program, targets[i], stops)
+        # A thin wrapper case forwards to one submethod: the real body (and its leaf anchors)
+        # live in that function. Expanding one level makes MSVC8 (separate show()/load()) line up
+        # with MSVC6 (inline), so `calls` is a compiler-tolerant body fingerprint.
+        if len(anchors) == 1 and len(funcs) == 1 and funcs[0][0] == anchors[0]:
+            impl = funcs[0][0]
+            impl_entry = funcs[0][1]
+            impl_addr = "0x%x" % impl_entry.getOffset()
+            calls, _ = _walk_calls(program, impl_entry, set())
+        else:
+            impl = None
+            impl_addr = "0x%x" % targets[i].getOffset()  # body is inline in the case block
+            calls = anchors
+        rows.append({
+            "owner": owner, "runner": runner, "id": i + sw["base"],
+            "case_addr": "0x%x" % targets[i].getOffset(),
+            "impl": impl, "impl_addr": impl_addr, "calls": calls,
+        })
+    return rows
+
+
 def extract_events(program):
     """Per CMC_*::getBehavioursList, collect the ordered event-name literals (ONINIT, ONDONE, ...).
 
@@ -583,9 +799,10 @@ def run():
     events = extract_events(program)
     fields = extract_script_fields(program)
     struct_layout, field_inheritance = extract_struct_layout(program)
+    method_dispatch = extract_method_dispatch(program)
 
     snapshot = {
-        "schema_version": 3,
+        "schema_version": 4,
         "binary": {
             "name": program.getName(),
             "sha256": sha256_of(program),
@@ -600,6 +817,7 @@ def run():
         "fields": fields,
         "field_inheritance": field_inheritance,
         "struct_layout": struct_layout,
+        "method_dispatch": method_dispatch,
     }
 
     args = getScriptArgs()
@@ -610,9 +828,9 @@ def run():
     finally:
         fh.close()
 
-    print("[+] %s [%s/%s]: %d types, %d methods, %d events, %d fields (%d layout) -> %s" % (
+    print("[+] %s [%s/%s]: %d types, %d methods, %d events, %d fields (%d layout, %d dispatch) -> %s" % (
         program.getName(), engine, compiler, len(types), len(methods),
-        len(events), len(fields), len(struct_layout), out_path))
+        len(events), len(fields), len(struct_layout), len(method_dispatch), out_path))
 
 
 run()

tests/test_diff.py

@@ -72,6 +72,26 @@ def test_field_type_change_and_owner_filter():
     assert d["fields"]["added"] == [] and d["fields"]["removed"] == []
 
 
+def test_method_dispatch_body_change():
+    old = _snap(
+        methods=[{"owner": "CMC_Animo", "name": "SHOW", "id": 1}],
+        method_dispatch=[{"owner": "CMC_Animo", "id": 1, "impl": None,
+                          "impl_addr": "0x1", "calls": ["CMC_Animo::getAnimo", "vtbl+0xa0"]}],
+    )
+    new = _snap(
+        methods=[{"owner": "CMC_Animo", "name": "SHOW", "id": 1}],
+        method_dispatch=[{"owner": "CMC_Animo", "id": 1, "impl": None,
+                          "impl_addr": "0x1", "calls": ["CMC_Animo::getAnimo", "vtbl+0xa4"]}],
+    )
+    d = compute_diff(old, new)["method_dispatch"]
+    assert len(d["changed"]) == 1
+    ch = d["changed"][0]
+    assert ch["item"]["name"] == "SHOW"  # name joined from the methods axis on (owner, id)
+    assert ch["changes"]["calls"] == [["CMC_Animo::getAnimo", "vtbl+0xa0"],
+                                      ["CMC_Animo::getAnimo", "vtbl+0xa4"]]
+    assert "METHOD BODIES" in render_text(compute_diff(old, new))
+
+
 def test_render_no_diff():
     out = render_text(compute_diff(_snap(), _snap()))
     assert "(no differences)" in out
@@ -101,3 +121,10 @@ def test_golden_pair_piklib_to_bloomoo():
     # rendering must not raise and must mention the new types
     text = render_text(d)
     assert "GRBUFFER" in text and "MOUSE" in text
+
+    # method bodies recovered cross-compiler: Animo SHOW (id 1) maps to the same vtable leaf
+    # despite MSVC6 inlining it and MSVC8 keeping it as a separate show() function
+    disp_old = {(r["owner"], r["id"]): r for r in old.method_dispatch}
+    disp_new = {(r["owner"], r["id"]): r for r in new.method_dispatch}
+    assert disp_old[("CMC_Animo", 1)]["calls"][-1] == "vtbl+0xa0"
+    assert disp_new[("CMC_Animo", 1)]["calls"][-1] == "vtbl+0xa0"