| name | find-CEntitySystem_m_entityNames |
| description | Final-guarantee fallback for the find-CEntitySystem_m_entityNames preprocessor. Recovers
CEntitySystem::m_entityNames in CS2 server.dll / libserver.so by decompiling
CEntitySystem_AddEntityToNameMap and recognizing its ordered-map/RB-tree lookup whether the lookup helper is
emitted as a separate function or inlined into the predecessor. Use when
ida_preprocessor_scripts/find-CEntitySystem_m_entityNames.py cannot resolve the member because the
LLM_DECOMPILE reference shape moved across the inline boundary.
Trigger: CEntitySystem_m_entityNames
|
| disable-model-invocation | true |
Find CEntitySystem_m_entityNames (final-guarantee fallback)
Recover CEntitySystem::m_entityNames in CS2 server.dll / libserver.so using IDA Pro MCP tools. This is
the Agent fallback for find-CEntitySystem_m_entityNames; it runs only after the preprocessor fails. Produce
the missing struct-offset YAML even when the anonymous ordered-map lookup helper was inlined into
CEntitySystem_AddEntityToNameMap and the expected sub_*(this + off + 8, this + off, &key) call no longer
exists.
Realworld Function References
Read the platform-relevant YAML before searching in IDA. Treat every address and offset as a reference-build
value only and verify it against the current binary.
ida_preprocessor_scripts/references/server/CEntitySystem_AddEntityToNameMap.windows.yaml
ida_preprocessor_scripts/references/server/CEntitySystem_AddEntityToNameMap.linux.yaml
The Linux reference includes both the historical lookup helper pseudocode and the predecessor pseudocode. Its
a1 + 2800 annotation is an older-layout example; build 14168 moved the Linux member to 0xAF8. Never copy a
reference displacement without checking the current function.
Background and semantic fingerprint
CEntitySystem_AddEntityToNameMap(this, identity) reads the entity-name key from identity + 0x18, returns
when it is null, looks the key up in this->m_entityNames, and either appends the entity handle to an existing
CEntityNameList or allocates a new 32-byte list and inserts it into the ordered map.
Identify this map operation by the whole fingerprint, not by an anonymous helper name:
- the key comes from
identity + 0x18;
- RB-tree node indices use
0xFFFF as the null sentinel;
- nodes are 24 bytes and compare their key field against the entity-name key;
- the duplicate path calls
_UtlRBTree_FailedInsertDuplicate or references the assertion text
Found existing value when inserting into tree;
- the new-value path allocates 32 bytes for the
CEntityNameList and inserts the entity handle into it.
The first argument is the owning CEntitySystem *: rcx on Windows and rdi on Linux, commonly copied to a
callee-saved register such as rbx or r12. Confirm every candidate displacement is relative to that pointer.
Robustness principle: accept both compiler shapes
Do not search for the literal name sub_1E59BD0; anonymous names and function boundaries change per build.
- Decompile
CEntitySystem_AddEntityToNameMap and first look for a separate ordered-map/RB-tree lookup call.
Historical Linux builds pass values equivalent to this + off + 8, this + off, and &key. Windows may
materialize this + off, then pass this + off + 8 plus a small context object containing the base and key.
- If that call is absent, assume the helper was inlined. Locate the direct RB-tree traversal using the
semantic fingerprint above. The usual container field cluster is:
- node count at
this + off;
- allocation/capacity flags at
this + off + 2;
- node-storage pointer at
this + off + 8;
- root index at
this + off + 0x10;
- nearby free-list/tree bookkeeping at
this + off + 0x12 and this + off + 0x14.
- Infer one common
off from at least three of those accesses and verify it against the insertion path. Prefer
a direct lea reg, [this + off] that feeds tree insertion/bookkeeping. On Linux 14168, for example, the
inlined traversal accesses this + 0xB08, this + 0xAFA, and this + 0xB00, then materializes
this + 0xAF8; all four imply off = 0xAF8.
- If the predecessor calls a plausible lookup helper instead, decompile it and follow the arguments. Recover
off from the caller's this-relative expressions; helper-local offsets are offsets within the map, not
within CEntitySystem.
Reject candidates that do not participate in the entity-name-key lookup and subsequent existing/new
CEntityNameList branches.
Output inventory
Offsets are ground-truth reference values from build 14168 and must be re-derived for the current binary.
| Output symbol | Kind | Windows | Linux | Writer skill |
|---|
CEntitySystem_m_entityNames | struct member | 0xAF0 | 0xAF8 | /write-structoffset-as-yaml |
Platform gating: emit this output on both Windows and Linux. struct_name is CEntitySystem, member_name
is m_entityNames, and the recorded size is 8.
Step 0. Skip an existing output
Determine the current platform from the input binary. If CEntitySystem_m_entityNames.<platform>.yaml already
exists beside it and parses to a non-empty mapping, skip the target because the preprocessor or an earlier run
already produced it. List YAMLs with:
mcp__ida-pro-mcp__py_eval code="import idaapi, os; d=os.path.dirname(idaapi.get_input_file_path()); print('\n'.join(sorted(f for f in os.listdir(d) if f.endswith('.yaml'))))"
Step 1. Load and decompile the predecessor
ALWAYS Use SKILL /get-func-from-yaml with
func_name=CEntitySystem_AddEntityToNameMap to obtain func_va. If it errors, STOP and report the missing
prerequisite.
Then decompile and, when needed, disassemble the function:
mcp__ida-pro-mcp__decompile addr="<CEntitySystem_AddEntityToNameMap.func_va>"
mcp__ida-pro-mcp__disasm addr="<CEntitySystem_AddEntityToNameMap.func_va>"
Track the this register and apply the separate-helper/inlined-helper procedure above. Do not fail merely
because no three-argument lookup call appears.
Step 2. Generate the signature and write YAML
Prefer an instruction that directly contains off, such as lea reg, [this + off], in the verified map
lookup/insertion block.
- ALWAYS Use SKILL
/generate-signature-for-structoffset with the instruction address and the resolved
struct_offset=off. The target instruction must keep the full displacement fixed and
offset_sig_disp=0.
- ALWAYS Use SKILL
/write-structoffset-as-yaml with:
struct_name=CEntitySystem
member_name=m_entityNames
offset=<resolved off>
size=8
offset_sig=<generated struct_sig>
offset_sig_disp=0
If the current compiler never materializes this + off directly and only accesses off + 2, off + 8, or
off + 0x10, still write the verified base offset with size=8; set offset_sig=None and
offset_sig_disp=None rather than generating a signature for the wrong subfield displacement.
Failure handling
- Missing
CEntitySystem_AddEntityToNameMap.<platform>.yaml -> STOP and report the prerequisite.
- Fewer than three coherent container-field accesses and no trustworthy separate-helper call -> STOP and
report the unresolved member; do not guess from the 14168 reference value.
- A non-unique offset signature -> try another direct
this + off instruction, then write offset-only if the
member is otherwise proven.
- Never emit a Windows result while analyzing Linux or a Linux result while analyzing Windows.
Output YAML filename
Write beside the binary as CEntitySystem_m_entityNames.windows.yaml for server.dll or
CEntitySystem_m_entityNames.linux.yaml for libserver.so.