[WIP] Implement IXCLRDataExceptionState state comparison

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataExceptionState.cs

@@ -14,6 +14,7 @@ public sealed unsafe partial class ClrDataExceptionState : IXCLRDataExceptionSta
     private readonly Target _target;
     private readonly TargetPointer _threadAddress;
     private readonly uint _flags;
+    private readonly TargetPointer _exceptionInfoAddress;
     private readonly TargetPointer _thrownObjectHandle;
     private readonly TargetPointer _previousExInfoAddress;
     private readonly IXCLRDataExceptionState? _legacyImpl;
@@ -22,13 +23,15 @@ public ClrDataExceptionState(
         Target target,
         TargetPointer threadAddress,
         uint flags,
+        TargetPointer exceptionInfoAddress,
         TargetPointer thrownObjectHandle,
         TargetPointer previousExInfoAddress,
         IXCLRDataExceptionState? legacyImpl)
     {
         _target = target;
         _threadAddress = threadAddress;
         _flags = flags;
+        _exceptionInfoAddress = exceptionInfoAddress;
         _thrownObjectHandle = thrownObjectHandle;
         _previousExInfoAddress = previousExInfoAddress;
         _legacyImpl = legacyImpl;
@@ -91,6 +94,7 @@ int IXCLRDataExceptionState.GetPrevious(DacComNullableByRef<IXCLRDataExceptionSt
                     _target,
                     _threadAddress,
                     (uint)CLRDataExceptionStateFlag.CLRDATA_EXCEPTION_DEFAULT,
+                    _previousExInfoAddress,
                     prevExThrownObjectHandle,
                     nextNestedException,
                     legacyPrevious
@@ -213,9 +217,81 @@ int IXCLRDataExceptionState.Request(uint reqCode, uint inBufferSize, byte* inBuf
     }
 
     int IXCLRDataExceptionState.IsSameState(EXCEPTION_RECORD64* exRecord, uint contextSize, byte* cxRecord)
-        => LegacyFallbackHelper.CanFallback() && _legacyImpl is not null ? _legacyImpl.IsSameState(exRecord, contextSize, cxRecord) : HResults.E_NOTIMPL;
+    {
+        int hr = IsSameState2((uint)CLRDataExceptionSameFlag.CLRDATA_EXSAME_SECOND_CHANCE, exRecord);
+#if DEBUG
+        if (_legacyImpl is not null)
+        {
+            int hrLocal = _legacyImpl.IsSameState(exRecord, contextSize, cxRecord);
+            Debug.ValidateHResult(hr, hrLocal);
+        }
+#endif
+        return hr;
+    }
+
     int IXCLRDataExceptionState.IsSameState2(uint flags, EXCEPTION_RECORD64* exRecord, uint contextSize, byte* cxRecord)
-        => LegacyFallbackHelper.CanFallback() && _legacyImpl is not null ? _legacyImpl.IsSameState2(flags, exRecord, contextSize, cxRecord) : HResults.E_NOTIMPL;
+    {
+        int hr = IsSameState2(flags, exRecord);
+#if DEBUG
+        if (_legacyImpl is not null)
+        {
+            int hrLocal = _legacyImpl.IsSameState2(flags, exRecord, contextSize, cxRecord);
+            Debug.ValidateHResult(hr, hrLocal);
+        }
+#endif
+        return hr;
+    }
+
+    private int IsSameState2(uint flags, EXCEPTION_RECORD64* exRecord)
+    {
+        int hr = HResults.S_FALSE;
+        try
+        {
+            if ((flags & ~(uint)(CLRDataExceptionSameFlag.CLRDATA_EXSAME_SECOND_CHANCE | CLRDataExceptionSameFlag.CLRDATA_EXSAME_FIRST_CHANCE)) != 0)
+                throw new ArgumentException();
+
+            if ((_flags & (uint)CLRDataExceptionStateFlag.CLRDATA_EXCEPTION_PARTIAL) != 0)
+            {
+                if ((flags & (uint)CLRDataExceptionSameFlag.CLRDATA_EXSAME_FIRST_CHANCE) != 0)
+                    hr = HResults.S_OK;
+            }
+            else
+            {
+                if (exRecord is null)
+                    throw new NullReferenceException();
+
+                TargetPointer exceptionRecord;
+                if (_exceptionInfoAddress != TargetPointer.Null)
+                {
+                    Target.TypeInfo exceptionInfoType = _target.GetTypeInfo(DataType.ExceptionInfo);
+                    exceptionRecord = _target.ReadPointer(
+                        _exceptionInfoAddress + (ulong)exceptionInfoType.Fields["ExceptionRecord"].Offset);
+                }
+                else
+                {
+                    ThreadData threadData = _target.Contracts.Thread.GetThreadData(_threadAddress);
+                    exceptionRecord = threadData.OSExceptionRecord;
+                }
+
+                TargetPointer exceptionAddress = _target.ReadPointer(
+                    exceptionRecord + (ulong)(sizeof(uint) * 2 + _target.PointerSize));
+                TargetPointer requestedAddress = new(
+                    _target.PointerSize == sizeof(ulong)
+                        ? exRecord->ExceptionAddress
+                        : (uint)exRecord->ExceptionAddress);
+
+                if (exceptionAddress == requestedAddress)
+                    hr = HResults.S_OK;
+            }
+        }
+        catch (System.Exception ex)
+        {
+            hr = ex.HResult;
+        }
+
+        return hr;
+    }
+
     int IXCLRDataExceptionState.GetTask(DacComNullableByRef<IXCLRDataTask> task)
     {
         int hr = HResults.S_OK, hrLocal = HResults.S_OK;

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/ClrDataTask.cs

@@ -114,7 +114,7 @@ int IXCLRDataTask.GetCurrentExceptionState(DacComNullableByRef<IXCLRDataExceptio
             else
             {
                 Contracts.ThreadData threadData = _target.Contracts.Thread.GetThreadData(_address);
-                exception.Interface = new ClrDataExceptionState(_target, _address, (uint)CLRDataExceptionStateFlag.CLRDATA_EXCEPTION_DEFAULT, thrownObjectHandle, threadData.FirstNestedException, legacyExceptionState);
+                exception.Interface = new ClrDataExceptionState(_target, _address, (uint)CLRDataExceptionStateFlag.CLRDATA_EXCEPTION_DEFAULT, TargetPointer.Null, thrownObjectHandle, threadData.FirstNestedException, legacyExceptionState);
             }
         }
         catch (System.Exception ex)
@@ -155,7 +155,7 @@ int IXCLRDataTask.GetLastExceptionState(DacComNullableByRef<IXCLRDataExceptionSt
             }
             else
             {
-                exception.Interface = new ClrDataExceptionState(_target, _address, (uint)CLRDataExceptionStateFlag.CLRDATA_EXCEPTION_PARTIAL, thrownObjectHandle, TargetPointer.Null, legacyExceptionState);
+                exception.Interface = new ClrDataExceptionState(_target, _address, (uint)CLRDataExceptionStateFlag.CLRDATA_EXCEPTION_PARTIAL, TargetPointer.Null, thrownObjectHandle, TargetPointer.Null, legacyExceptionState);
             }
         }
         catch (System.Exception ex)

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/IXCLRData.cs

@@ -961,6 +961,13 @@ public enum CLRDataExceptionStateFlag : uint
     CLRDATA_EXCEPTION_PARTIAL = 0x2,
 }
 
+[Flags]
+public enum CLRDataExceptionSameFlag : uint
+{
+    CLRDATA_EXSAME_SECOND_CHANCE = 0,
+    CLRDATA_EXSAME_FIRST_CHANCE = 0x1,
+}
+
 [GeneratedComInterface]
 [Guid("75DA9E4C-BD33-43C8-8F5C-96E8A5241F57")]
 public unsafe partial interface IXCLRDataExceptionState

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/SOSDacImpl.IXCLRDataProcess.cs

@@ -681,6 +681,7 @@ int IXCLRDataProcess.TranslateExceptionRecordToNotification(EXCEPTION_RECORD64*
                             _target,
                             exception.ThreadAddress,
                             (uint)CLRDataExceptionStateFlag.CLRDATA_EXCEPTION_DEFAULT,
+                            TargetPointer.Null,
                             thrownObjectHandle,
                             threadData.FirstNestedException,
                             null));