Ignore inherit param for ParameterInfo.GetCustomAttributes (#57769)

It is documented that the inherit flag is ignored. Attribute.GetCustomAttributes is to be used to search inheritance chain. This change is only for the Mono classlib implementation. CoreCLR already has this behavior. Adding a test to verify behavior.
dotnet · Aug 20, 2021 · 1be8fd8 · 1be8fd8
1 parent 6cc686f
commit 1be8fd8
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Showing 2 changed files with 32 additions and 3 deletions.
diff --git a/src/libraries/System.Reflection/tests/ParameterInfoTests.cs b/src/libraries/System.Reflection/tests/ParameterInfoTests.cs
@@ -229,6 +229,22 @@ public void CustomAttributesTest(Type attrType)
             Assert.True(prov.IsDefined(attrType, true));
         }
 
+        [Theory]
+        [InlineData(0, true, 30)]
+        [InlineData(1, false, -1)]
+        [InlineData(2, true, 50)]
+        public void CustomAttributesInheritanceTest(int paramIndex, bool exists, int expectedMyAttributeValue)
+        {
+            ParameterInfo parameterInfo = GetParameterInfo(typeof(DerivedParameterInfoMetadata), "VirtualMethodWithCustomAttributes", paramIndex);
+            CustomAttributeData attribute = parameterInfo.CustomAttributes.SingleOrDefault(a => a.AttributeType.Equals(typeof(MyAttribute)));
+            Assert.Equal(exists, attribute != null);
+
+            ICustomAttributeProvider prov = parameterInfo as ICustomAttributeProvider;
+            MyAttribute myAttribute = prov.GetCustomAttributes(typeof(MyAttribute), true).SingleOrDefault() as MyAttribute;
+            Assert.Equal(exists, myAttribute != null);
+            Assert.Equal(expectedMyAttributeValue, exists ? myAttribute.Value : expectedMyAttributeValue);
+        }
+
         [Fact]
         public void VerifyGetCustomAttributesData()
         {
@@ -345,6 +361,7 @@ public void Foo2([CustomBindingFlags(Value = BindingFlags.IgnoreCase)] BindingFl
             public void Foo3([CustomBindingFlags(Value = BindingFlags.DeclaredOnly)] BindingFlags bf = BindingFlags.FlattenHierarchy ) { }
 
             public void MethodWithCustomAttribute([My(2)]string str, int iValue, long lValue) { }
+            public virtual void VirtualMethodWithCustomAttributes([My(3)]int val1, [My(4)]int val2, int val3) { }
 
             public void Method1(string str, int iValue, long lValue) { }
             public void Method2() { }
@@ -372,6 +389,11 @@ public void MethodWithNullableEnum(AttributeTargets? arg = AttributeTargets.All)
             public int MethodWithOptionalDefaultOutInMarshalParam([MarshalAs(UnmanagedType.LPWStr)][Out][In] string str = "") { return 1; }
         }
 
+        public class DerivedParameterInfoMetadata : ParameterInfoMetadata
+        {
+            override public void VirtualMethodWithCustomAttributes([My(30)]int val1, int val2, [My(50)]int val3) { }
+        }
+
         public class GenericClass<T>
         {
             public void GenericMethod(T t) { }
@@ -380,7 +402,8 @@ public void GenericMethod(T t) { }
 
         private class MyAttribute : Attribute
         {
-            internal MyAttribute(int i) { }
+            public int Value {get; private set;}
+            internal MyAttribute(int i) { Value = i;}
         }
 
         internal sealed class CustomBindingFlagsAttribute : UsableCustomConstantAttribute

diff --git a/src/mono/System.Private.CoreLib/src/System/Reflection/RuntimeParameterInfo.cs b/src/mono/System.Private.CoreLib/src/System/Reflection/RuntimeParameterInfo.cs
@@ -181,14 +181,20 @@ int MetadataToken
         override
         object[] GetCustomAttributes(bool inherit)
         {
-            return CustomAttribute.GetCustomAttributes(this, inherit);
+            // It is documented that the inherit flag is ignored.
+            // Attribute.GetCustomAttributes is to be used to search
+            // inheritance chain.
+            return CustomAttribute.GetCustomAttributes(this, false);
         }
 
         public
         override
         object[] GetCustomAttributes(Type attributeType, bool inherit)
         {
-            return CustomAttribute.GetCustomAttributes(this, attributeType, inherit);
+            // It is documented that the inherit flag is ignored.
+            // Attribute.GetCustomAttributes is to be used to search
+            // inheritance chain.
+            return CustomAttribute.GetCustomAttributes(this, attributeType, false);
         }
 
         internal static object? GetDefaultValueImpl(ParameterInfo pinfo)