[cDAC] Implement ISOSDacInterface::GetMethodDescPtrFromIp (#110755)

Contributes to #108553

Tested using `!sos ip2md <ip>`.

---------

Co-authored-by: Max Charlamb <[email protected]>
Co-authored-by: Elinor Fung <[email protected]>

Author: 3 people

src/native/managed/cdacreader/src/Legacy/SOSDacImpl.cs

@@ -569,7 +569,62 @@ int ISOSDacInterface.GetMethodDescName(ulong methodDesc, uint count, char* name,
     int ISOSDacInterface.GetMethodDescPtrFromFrame(ulong frameAddr, ulong* ppMD)
         => _legacyImpl is not null ? _legacyImpl.GetMethodDescPtrFromFrame(frameAddr, ppMD) : HResults.E_NOTIMPL;
     int ISOSDacInterface.GetMethodDescPtrFromIP(ulong ip, ulong* ppMD)
-        => _legacyImpl is not null ? _legacyImpl.GetMethodDescPtrFromIP(ip, ppMD) : HResults.E_NOTIMPL;
+    {
+        if (ip == 0 || ppMD == null)
+            return HResults.E_INVALIDARG;
+
+        int hr = HResults.E_NOTIMPL;
+
+        try
+        {
+            IExecutionManager executionManager = _target.Contracts.ExecutionManager;
+            IRuntimeTypeSystem rts = _target.Contracts.RuntimeTypeSystem;
+
+            CodeBlockHandle? handle = executionManager.GetCodeBlockHandle(new TargetCodePointer(ip));
+            if (handle is CodeBlockHandle codeHandle)
+            {
+                TargetPointer methodDescAddr = executionManager.GetMethodDesc(codeHandle);
+
+                try
+                {
+                    // Runs validation of MethodDesc
+                    // if validation fails, should return E_INVALIDARG
+                    rts.GetMethodDescHandle(methodDescAddr);
+
+                    *ppMD = methodDescAddr.Value;
+                    hr = HResults.S_OK;
+                }
+                catch (System.Exception)
+                {
+                    hr = HResults.E_INVALIDARG;
+                }
+            }
+            else
+            {
+                hr = HResults.E_FAIL;
+            }
+        }
+        catch (System.Exception ex)
+        {
+            hr = ex.HResult;
+        }
+
+#if DEBUG
+        if (_legacyImpl is not null)
+        {
+            ulong ppMDLocal;
+            int hrLocal = _legacyImpl.GetMethodDescPtrFromIP(ip, &ppMDLocal);
+
+            Debug.Assert(hrLocal == hr);
+            if (hr == HResults.S_OK)
+            {
+                Debug.Assert(*ppMD == ppMDLocal);
+            }
+        }
+#endif
+        return hr;
+    }
+
     int ISOSDacInterface.GetMethodDescTransparencyData(ulong methodDesc, void* data)
         => _legacyImpl is not null ? _legacyImpl.GetMethodDescTransparencyData(methodDesc, data) : HResults.E_NOTIMPL;
     int ISOSDacInterface.GetMethodTableData(ulong mt, DacpMethodTableData* data)