Add code to check if class objects are equal (#2836)

Author: josesimoes

src/CLR/Core/CLR_RT_HeapBlock.cpp

@@ -1364,6 +1364,52 @@ bool CLR_RT_HeapBlock::ObjectsEqual(
             }
             break;
 
+        case DATATYPE_CLASS:
+        {
+            const CLR_RT_HeapBlock *objLeft = &pArgLeft;
+            const CLR_RT_HeapBlock *objRight = &pArgRight;
+
+            CLR_RT_TypeDef_Instance classLeftObj;
+            classLeftObj.InitializeFromIndex(objLeft->ObjectCls());
+            CLR_RT_TypeDef_Instance classRightObj;
+            classRightObj.InitializeFromIndex(objRight->ObjectCls());
+
+            if (classLeftObj.m_data == classRightObj.m_data)
+            {
+                // this has been already checked above, still adding it here for completeness
+                if (&pArgLeft == &pArgRight)
+                {
+                    return true;
+                }
+
+                // check if the objects have the same number of fields
+                int leftClassTotFields = classLeftObj.CrossReference().m_totalFields;
+                int rightClassTotFields = classRightObj.CrossReference().m_totalFields;
+
+                if (leftClassTotFields > 0 && rightClassTotFields > 0 && leftClassTotFields == rightClassTotFields)
+                {
+                    int equalFieldsCount = 0;
+
+                    // loop through the fields and compare them
+                    do
+                    {
+                        if (ObjectsEqual(
+                                objLeft[leftClassTotFields + CLR_RT_HeapBlock::HB_Object_Fields_Offset],
+                                objRight[rightClassTotFields + CLR_RT_HeapBlock::HB_Object_Fields_Offset],
+                                false))
+                        {
+                            // fields are equal
+                            equalFieldsCount++;
+                        }
+                    } while (--leftClassTotFields > 0);
+
+                    // check if all fields are equal
+                    return equalFieldsCount == leftClassTotFields;
+                }
+            }
+        }
+        break;
+
         default:
 
             if ((leftDataType == rightDataType) && fSameReference == false)