[cDAC] Add DacDbi APIs to fill DebuggerIPCE_ExpandedTypeData#128001
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[cDAC] Add DacDbi APIs to fill DebuggerIPCE_ExpandedTypeData#128001
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add fill expanded type data apis
rcj1
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Tagging subscribers to this area: @steveisok, @tommcdon, @dotnet/dotnet-diag |
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Pull request overview
This PR extends the cDAC DacDbi surface to produce DebuggerIPCE_ExpandedTypeData for a type handle or object address, and adds a RuntimeTypeSystem contract helper for recognizing the System.Object method table (so ELEMENT_TYPE_OBJECT can be reported distinctly from ELEMENT_TYPE_CLASS).
Changes:
- Add
IRuntimeTypeSystem.IsObject(TypeHandle)and plumb a newObjectMethodTableglobal through the contract + test mocks. - Implement
TypeHandleToExpandedTypeInfoandGetObjectExpandedTypeInfoin the managedDacDbiImpl, including little-endian writes matching nativePortable<T>. - Update native DBI interface/IDL and call sites to route “type id -> type info” through
TypeHandleToExpandedTypeInfo, and removeGetObjectExpandedTypeInfoFromID.
Show a summary per file
| File | Description |
|---|---|
| src/native/managed/cdac/tests/MockDescriptors/MockDescriptors.RuntimeTypeSystem.cs | Adds a mock global for the Object method table and patches it to System.Object’s MT in the mock target. |
| src/native/managed/cdac/tests/MethodTableTests.cs | Extends contract globals and asserts IsObject behavior for FreeObject MT vs System.Object MT. |
| src/native/managed/cdac/tests/DumpTests/RuntimeTypeSystemDumpTests.cs | Adds dump-based assertions for IsObject across object/free/string MTs. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/Dbi/IDacDbiInterface.cs | Introduces managed projections of AreValueTypesBoxed and DebuggerIPCE_*TypeData and updates method signatures to typed pointers. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/Dbi/DacDbiImpl.cs | Implements TypeHandleToExpandedTypeInfo / GetObjectExpandedTypeInfo and shared filling helpers with Portable-compatible endianness. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/RuntimeTypeSystem_1.cs | Reads the ObjectMethodTable global and implements IsObject. |
| src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/Contracts/IRuntimeTypeSystem.cs | Adds the new IsObject(TypeHandle) API to the public contract interface. |
| src/coreclr/inc/dacdbi.idl | Changes TypeHandleToExpandedTypeInfo to take a raw UINT64 and drops GetObjectExpandedTypeInfoFromID. |
| src/coreclr/debug/inc/dacdbistructures.h | Gives AreValueTypesBoxed explicit values (0/1/2). |
| src/coreclr/debug/inc/dacdbiinterface.h | Updates the COM interface signature and removes GetObjectExpandedTypeInfoFromID. |
| src/coreclr/debug/di/rstype.cpp | Updates RS to call the new TypeHandleToExpandedTypeInfo signature (but currently extracts the handle unsafely). |
| src/coreclr/debug/di/process.cpp | Routes GetTypeForTypeID through TypeHandleToExpandedTypeInfo using COR_TYPEID.token1. |
| src/coreclr/debug/daccess/dacdbiimpl.h | Updates DAC interface declaration to match the new signature. |
| src/coreclr/debug/daccess/dacdbiimpl.cpp | Removes the old FromID method and updates implementation/callers for the new signature + zero-inits output structs. |
| docs/design/datacontracts/RuntimeTypeSystem.md | Documents IsObject and the ObjectMethodTable global (but the globals table still has an incorrect FreeObject global name). |
Copilot's findings
- Files reviewed: 15/15 changed files
- Comments generated: 5
Comment on lines
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| UINT64 id; | ||
| memcpy(&id, &data->vmTypeHandle, sizeof(UINT64)); |
Comment on lines
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| public int TypeHandleToExpandedTypeInfo(int boxed, ulong vmTypeHandle, DebuggerIPCE_ExpandedTypeData* pTypeInfo) | ||
| { | ||
| *pTypeInfo = default; | ||
| int hr = HResults.S_OK; | ||
| try | ||
| { | ||
| IRuntimeTypeSystem rts = _target.Contracts.RuntimeTypeSystem; | ||
| TypeHandle th = rts.GetTypeHandle(new TargetPointer(vmTypeHandle)); | ||
| TypeHandleToExpandedTypeInfoImpl(rts, (AreValueTypesBoxed)boxed, th, pTypeInfo); | ||
| } | ||
| catch (System.Exception ex) | ||
| { | ||
| hr = ex.HResult; | ||
| } | ||
| #if DEBUG | ||
| if (_legacy is not null) | ||
| { | ||
| DebuggerIPCE_ExpandedTypeData dataLocal; | ||
| int hrLocal = _legacy.TypeHandleToExpandedTypeInfo(boxed, vmTypeHandle, &dataLocal); | ||
| Debug.ValidateHResult(hr, hrLocal); | ||
| if (hr == HResults.S_OK) | ||
| { | ||
| ValidateExpandedTypeData(pTypeInfo, &dataLocal); | ||
| } | ||
| } | ||
| #endif | ||
| return hr; | ||
| } | ||
|
|
||
| public int GetObjectExpandedTypeInfo(int boxed, ulong addr, nint pTypeInfo) | ||
| => LegacyFallbackHelper.CanFallback() && _legacy is not null ? _legacy.GetObjectExpandedTypeInfo(boxed, addr, pTypeInfo) : HResults.E_NOTIMPL; | ||
| public int GetObjectExpandedTypeInfo(int boxed, ulong addr, DebuggerIPCE_ExpandedTypeData* pTypeInfo) | ||
| { | ||
| *pTypeInfo = default; | ||
| int hr = HResults.S_OK; | ||
| try | ||
| { | ||
| IRuntimeTypeSystem rts = _target.Contracts.RuntimeTypeSystem; | ||
| TargetPointer mtAddr = _target.Contracts.Object.GetMethodTableAddress(new TargetPointer(addr)); | ||
| TypeHandle th = rts.GetTypeHandle(mtAddr); | ||
| TypeHandleToExpandedTypeInfoImpl(rts, (AreValueTypesBoxed)boxed, th, pTypeInfo); | ||
| } |
| @@ -440,6 +442,7 @@ The contract depends on the following globals | |||
| | --- | --- | | |||
| | `ContinuationMethodTable` | A pointer to the address of the base `Continuation` `MethodTable`, or null if no continuations have been created | |||
| | `FreeObjectMethodTablePointer` | A pointer to the address of a `MethodTable` used by the GC to indicate reclaimed memory | |||
This was referenced May 10, 2026
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Implement DacDbi APIs
TypeHandleToExpandedTypeInfoandGetObjectExpandedTypeInfoin cDACAdd RuntimeTypeSystem cDAC API
public virtual bool IsObject(TypeHandle typeHandle);Tested on internal diagnostics tests