Do not check object references for equality after hot reload

src/coreclr/System.Private.CoreLib/src/System/Reflection/MdFieldInfo.cs

@@ -3,6 +3,7 @@
 
 using System.Diagnostics;
 using System.Globalization;
+using System.Reflection.Metadata;
 using RuntimeTypeCache = System.RuntimeType.RuntimeTypeCache;
 
 namespace System.Reflection
@@ -33,8 +34,7 @@ internal override bool CacheEquals(object? o)
             return
                 o is MdFieldInfo m &&
                 m.m_tkField == m_tkField &&
-                m_declaringType.TypeHandle.GetModuleHandle().Equals(
-                    m.m_declaringType.TypeHandle.GetModuleHandle());
+                ReferenceEquals(m_declaringType, m.m_declaringType);
         }
         #endregion
 
@@ -43,6 +43,13 @@ o is MdFieldInfo m &&
 
         public override int MetadataToken => m_tkField;
         internal override RuntimeModule GetRuntimeModule() { return m_declaringType.GetRuntimeModule(); }
+
+        public override bool Equals(object? obj) =>
+            ReferenceEquals(this, obj) ||
+            (MetadataUpdater.IsSupported && CacheEquals(obj));
+
+        public override int GetHashCode() =>
+            HashCode.Combine(m_tkField.GetHashCode(), m_declaringType.GetUnderlyingNativeHandle().GetHashCode());
         #endregion
 
         #region FieldInfo Overrides

src/coreclr/System.Private.CoreLib/src/System/Reflection/RtFieldInfo.cs

@@ -3,6 +3,7 @@
 
 using System.Diagnostics;
 using System.Globalization;
+using System.Reflection.Metadata;
 using System.Runtime.CompilerServices;
 using RuntimeTypeCache = System.RuntimeType.RuntimeTypeCache;
 
@@ -183,6 +184,13 @@ internal override RuntimeModule GetRuntimeModule()
             return RuntimeTypeHandle.GetModule(RuntimeFieldHandle.GetApproxDeclaringType(this));
         }
 
+        public override bool Equals(object? obj) =>
+            ReferenceEquals(this, obj) ||
+            (MetadataUpdater.IsSupported && CacheEquals(obj));
+
+        public override int GetHashCode() =>
+            HashCode.Combine(m_fieldHandle.GetHashCode(), m_declaringType.GetUnderlyingNativeHandle().GetHashCode());
+
         #endregion
 
         #region FieldInfo Overrides

src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimeConstructorInfo.CoreCLR.cs

@@ -5,6 +5,7 @@
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
+using System.Reflection.Metadata;
 using System.Runtime.CompilerServices;
 using System.Text;
 using System.Threading;
@@ -72,7 +73,8 @@ internal RuntimeConstructorInfo(
         RuntimeMethodHandleInternal IRuntimeMethodInfo.Value => new RuntimeMethodHandleInternal(m_handle);
 
         internal override bool CacheEquals(object? o) =>
-            o is RuntimeConstructorInfo m && m.m_handle == m_handle;
+            o is RuntimeConstructorInfo m && m.m_handle == m_handle &&
+            ReferenceEquals(m_declaringType, m.m_declaringType);
 
         internal Signature Signature
         {
@@ -118,6 +120,13 @@ public override string ToString()
 
             return m_toString;
         }
+
+        public override bool Equals(object? obj) =>
+            ReferenceEquals(this, obj) ||
+            (MetadataUpdater.IsSupported && CacheEquals(obj));
+
+        public override int GetHashCode() =>
+            HashCode.Combine(m_handle.GetHashCode(), m_declaringType.GetUnderlyingNativeHandle().GetHashCode());
         #endregion
 
         #region ICustomAttributeProvider

src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimeEventInfo.cs

@@ -3,6 +3,7 @@
 
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Reflection.Metadata;
 using RuntimeTypeCache = System.RuntimeType.RuntimeTypeCache;
 
 namespace System.Reflection
@@ -53,8 +54,7 @@ internal override bool CacheEquals(object? o)
             return
                 o is RuntimeEventInfo m &&
                 m.m_token == m_token &&
-                RuntimeTypeHandle.GetModule(m_declaringType).Equals(
-                    RuntimeTypeHandle.GetModule(m.m_declaringType));
+                ReferenceEquals(m_declaringType, m.m_declaringType);
         }
 
         internal BindingFlags BindingFlags => m_bindingFlags;
@@ -68,6 +68,13 @@ public override string ToString()
 
             return m_addMethod.GetParametersNoCopy()[0].ParameterType.FormatTypeName() + " " + Name;
         }
+
+        public override bool Equals(object? obj) =>
+            ReferenceEquals(this, obj) ||
+            (MetadataUpdater.IsSupported && CacheEquals(obj));
+
+        public override int GetHashCode() =>
+            HashCode.Combine(m_token.GetHashCode(), m_declaringType.GetUnderlyingNativeHandle().GetHashCode());
         #endregion
 
         #region ICustomAttributeProvider

src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimeFieldInfo.cs

@@ -46,6 +46,7 @@ internal RuntimeType GetDeclaringTypeInternal()
 
         public override Module Module => GetRuntimeModule();
         public override bool IsCollectible => m_declaringType.IsCollectible;
+
         #endregion
 
         #region Object Overrides

src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimeMethodInfo.CoreCLR.cs

@@ -157,56 +157,18 @@ public override string ToString()
             return m_toString;
         }
 
-        public override int GetHashCode()
-        {
-            // See RuntimeMethodInfo.Equals() below.
-            if (IsGenericMethod)
-                return RuntimeHelpers.GetHashCodeOfPtr(m_handle);
-            else
-                return base.GetHashCode();
-        }
-
-        public override bool Equals(object? obj)
-        {
-            if (!IsGenericMethod)
-                return obj == (object)this;
-
-            // We cannot do simple object identity comparisons for generic methods.
-            // Equals will be called in CerHashTable when RuntimeType+RuntimeTypeCache.GetGenericMethodInfo()
-            // retrieve items from and insert items into s_methodInstantiations which is a CerHashtable.
-
-            RuntimeMethodInfo? mi = obj as RuntimeMethodInfo;
-
-            if (mi == null || !mi.IsGenericMethod)
-                return false;
-
-            // now we know that both operands are generic methods
-
-            IRuntimeMethodInfo handle1 = RuntimeMethodHandle.StripMethodInstantiation(this);
-            IRuntimeMethodInfo handle2 = RuntimeMethodHandle.StripMethodInstantiation(mi);
-            if (handle1.Value.Value != handle2.Value.Value)
-                return false;
-
-            Type[] lhs = GetGenericArguments();
-            Type[] rhs = mi.GetGenericArguments();
+        // We cannot do simple object identity comparisons due to generic methods.
+        // Equals and GetHashCode will be called in CerHashTable when RuntimeType+RuntimeTypeCache.GetGenericMethodInfo()
+        // retrieve items from and insert items into s_methodInstantiations.
 
-            if (lhs.Length != rhs.Length)
-                return false;
+        public override int GetHashCode() =>
+            HashCode.Combine(m_handle.GetHashCode(), m_declaringType.GetUnderlyingNativeHandle().GetHashCode());
 
-            for (int i = 0; i < lhs.Length; i++)
-            {
-                if (lhs[i] != rhs[i])
-                    return false;
-            }
+        public override bool Equals(object? obj) =>
+            obj is RuntimeMethodInfo m && m_handle == m.m_handle &&
+            ReferenceEquals(m_declaringType, m.m_declaringType) &&
+            ReferenceEquals(m_reflectedTypeCache.GetRuntimeType(), m.m_reflectedTypeCache.GetRuntimeType());
 
-            if (DeclaringType != mi.DeclaringType)
-                return false;
-
-            if (ReflectedType != mi.ReflectedType)
-                return false;
-
-            return true;
-        }
         #endregion
 
         #region ICustomAttributeProvider

src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimePropertyInfo.cs

@@ -4,6 +4,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Globalization;
+using System.Reflection.Metadata;
 using System.Text;
 using RuntimeTypeCache = System.RuntimeType.RuntimeTypeCache;
 
@@ -55,8 +56,7 @@ internal override bool CacheEquals(object? o)
             return
                 o is RuntimePropertyInfo m &&
                 m.m_token == m_token &&
-                RuntimeTypeHandle.GetModule(m_declaringType).Equals(
-                    RuntimeTypeHandle.GetModule(m.m_declaringType));
+                ReferenceEquals(m_declaringType, m.m_declaringType);
         }
 
         internal Signature Signature
@@ -179,6 +179,13 @@ public override IList<CustomAttributeData> GetCustomAttributesData()
         public override Module Module => GetRuntimeModule();
         internal RuntimeModule GetRuntimeModule() { return m_declaringType.GetRuntimeModule(); }
         public override bool IsCollectible => m_declaringType.IsCollectible;
+
+        public override bool Equals(object? obj) =>
+            ReferenceEquals(this, obj) ||
+            (MetadataUpdater.IsSupported && CacheEquals(obj));
+
+        public override int GetHashCode() =>
+            HashCode.Combine(m_token.GetHashCode(), m_declaringType.GetUnderlyingNativeHandle().GetHashCode());
         #endregion
 
         #region PropertyInfo Overrides

src/libraries/System.Runtime/tests/System/DelegateTests.cs

@@ -458,7 +458,7 @@ public static void SameGenericMethodObtainedViaDelegateAndReflectionAreSameForCl
             var m1 = ((MethodCallExpression)((Expression<Action>)(() => new ClassG().M<string, object>())).Body).Method;
             var m2 = new Action(new ClassG().M<string, object>).Method;
             Assert.True(m1.Equals(m2));
-            Assert.True(m1.GetHashCode().Equals(m2.GetHashCode()));
+            Assert.Equal(m1.GetHashCode(), m2.GetHashCode());
             Assert.Equal(m1.MethodHandle.Value, m2.MethodHandle.Value);
         }
 
@@ -468,7 +468,7 @@ public static void SameGenericMethodObtainedViaDelegateAndReflectionAreSameForSt
             var m1 = ((MethodCallExpression)((Expression<Action>)(() => new StructG().M<string, object>())).Body).Method;
             var m2 = new Action(new StructG().M<string, object>).Method;
             Assert.True(m1.Equals(m2));
-            Assert.True(m1.GetHashCode().Equals(m2.GetHashCode()));
+            Assert.Equal(m1.GetHashCode(), m2.GetHashCode());
             Assert.Equal(m1.MethodHandle.Value, m2.MethodHandle.Value);
         }