[release/7.0] Fix Equals in hot reload scenario (#78258)

* Fix Equals in hot reload scenario

* Update src/libraries/System.Runtime/tests/System/Reflection/ReflectionCacheTests.cs

Co-authored-by: Steve Harter <[email protected]>

Co-authored-by: Buyaa Namnan <[email protected]>
Co-authored-by: Buyaa Namnan <[email protected]>
Co-authored-by: Steve Harter <[email protected]>

Author: 3 people

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

@@ -46,7 +46,11 @@ o is MdFieldInfo m &&
 
         public override bool Equals(object? obj) =>
             ReferenceEquals(this, obj) ||
-            (MetadataUpdater.IsSupported && CacheEquals(obj));
+            (MetadataUpdater.IsSupported &&
+                obj is MdFieldInfo fi &&
+                fi.m_tkField == m_tkField &&
+                ReferenceEquals(fi.m_declaringType, m_declaringType) &&
+                ReferenceEquals(fi.m_reflectedTypeCache.GetRuntimeType(), m_reflectedTypeCache.GetRuntimeType()));
 
         public override int GetHashCode() =>
             HashCode.Combine(m_tkField.GetHashCode(), m_declaringType.GetUnderlyingNativeHandle().GetHashCode());

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

@@ -118,7 +118,10 @@ internal override RuntimeModule GetRuntimeModule()
 
         public override bool Equals(object? obj) =>
             ReferenceEquals(this, obj) ||
-            (MetadataUpdater.IsSupported && CacheEquals(obj));
+            (MetadataUpdater.IsSupported &&
+                obj is RtFieldInfo fi &&
+                fi.m_fieldHandle == m_fieldHandle &&
+                ReferenceEquals(fi.m_reflectedTypeCache.GetRuntimeType(), m_reflectedTypeCache.GetRuntimeType()));
 
         public override int GetHashCode() =>
             HashCode.Combine(m_fieldHandle.GetHashCode(), m_declaringType.GetUnderlyingNativeHandle().GetHashCode());

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

@@ -71,7 +71,11 @@ public override string ToString()
 
         public override bool Equals(object? obj) =>
             ReferenceEquals(this, obj) ||
-            (MetadataUpdater.IsSupported && CacheEquals(obj));
+            (MetadataUpdater.IsSupported &&
+                obj is RuntimeEventInfo ei &&
+                ei.m_token == m_token &&
+                ReferenceEquals(ei.m_declaringType, m_declaringType) &&
+                ReferenceEquals(ei.m_reflectedTypeCache.GetRuntimeType(), m_reflectedTypeCache.GetRuntimeType()));
 
         public override int GetHashCode() =>
             HashCode.Combine(m_token.GetHashCode(), m_declaringType.GetUnderlyingNativeHandle().GetHashCode());

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

@@ -182,7 +182,10 @@ public override IList<CustomAttributeData> GetCustomAttributesData()
 
         public override bool Equals(object? obj) =>
             ReferenceEquals(this, obj) ||
-            (MetadataUpdater.IsSupported && CacheEquals(obj));
+            (MetadataUpdater.IsSupported && obj is RuntimePropertyInfo rpi &&
+                rpi.m_token == m_token &&
+                ReferenceEquals(rpi.m_declaringType, m_declaringType) &&
+                ReferenceEquals(rpi.m_reflectedTypeCache.GetRuntimeType(), m_reflectedTypeCache.GetRuntimeType()));
 
         public override int GetHashCode() =>
             HashCode.Combine(m_token.GetHashCode(), m_declaringType.GetUnderlyingNativeHandle().GetHashCode());

src/libraries/System.Runtime/tests/System/Reflection/ReflectionCacheTests.cs

@@ -7,8 +7,18 @@
 
 namespace System.Reflection.Tests
 {
+    public class A
+    {
+        public string P { get; set; }
+        public int F;
+#pragma warning disable CS0067
+        public event EventHandler E;
+#pragma warning restore CS0067
+        public void M() { }
+    }
+
     [Collection(nameof(DisableParallelization))]
-    public class ReflectionCacheTests
+    public class ReflectionCacheTests : A
     {
         private static bool IsMetadataUpdateAndRemoteExecutorSupported => PlatformDetection.IsMetadataUpdateSupported && RemoteExecutor.IsSupported;
 
@@ -47,6 +57,12 @@ public void GetMembers_MultipleCalls_SameObjects()
             AssertSameEqualAndHashCodeEqual(fi1, fi2);
             AssertSameEqualAndHashCodeEqual(ei1, ei2);
             AssertSameEqualAndHashCodeEqual(ci1, ci2);
+
+            PropertyInfo parentProperty = typeof(A).GetProperty("P");
+            PropertyInfo childProperty = s_type.GetProperty("P");
+            Assert.NotNull(parentProperty);
+            Assert.NotNull(childProperty);
+            Assert.NotEqual(parentProperty, childProperty);
         }
 
         void AssertSameEqualAndHashCodeEqual(object o1, object o2)
@@ -87,6 +103,20 @@ public void GetMembers_MultipleCalls_ClearCache_ReflectionCacheTestsType()
                 EventInfo ei1 = s_type.GetEvent(nameof(Event1));
                 ConstructorInfo ci1 = s_type.GetConstructor(Type.EmptyTypes);
 
+                PropertyInfo parentProperty = typeof(A).GetProperty("P");
+                PropertyInfo childProperty = s_type.GetProperty("P");
+                FieldInfo parentField = typeof(A).GetField("F");
+                FieldInfo childField = s_type.GetField("F");
+                MethodInfo parentMethod = typeof(A).GetMethod("M");
+                MethodInfo childMethod = s_type.GetMethod("M");
+                EventInfo parentEvent = typeof(A).GetEvent("E");
+                EventInfo childEvent = s_type.GetEvent("E");
+
+                Assert.NotEqual(parentProperty, childProperty);
+                Assert.NotEqual(parentField, childField);
+                Assert.NotEqual(parentMethod, childMethod);
+                Assert.NotEqual(parentEvent, childEvent);
+
                 clearCache(new[] { typeof(ReflectionCacheTests) });
 
                 MethodInfo mi2 = s_type.GetMethod(nameof(Method));
@@ -95,6 +125,11 @@ public void GetMembers_MultipleCalls_ClearCache_ReflectionCacheTestsType()
                 EventInfo ei2 = s_type.GetEvent(nameof(Event1));
                 ConstructorInfo ci2 = s_type.GetConstructor(Type.EmptyTypes);
 
+                Assert.NotEqual(parentProperty, childProperty);
+                Assert.NotEqual(parentField, childField);
+                Assert.NotEqual(parentMethod, childMethod);
+                Assert.NotEqual(parentEvent, childEvent);
+
                 AssertNotSameSameButEqualAndHashCodeEqual(mi1, mi2);
                 AssertNotSameSameButEqualAndHashCodeEqual(pi1, pi2);
                 AssertNotSameSameButEqualAndHashCodeEqual(fi1, fi2);