Add support for custom attributes with constructors for methods and and classes (#102)

***PUBLISH_RELEASE***
***UPDATE_DEPENDENTS***

Author: josesimoes

source/nanoFramework.CoreLibrary/CoreLibrary.nfproj

@@ -129,6 +129,7 @@
     <Compile Include="System\Reflection\Binder.cs" />
     <Compile Include="System\Reflection\BindingFlags.cs" />
     <Compile Include="System\Reflection\ConstructorInfo.cs" />
+    <Compile Include="System\Reflection\CustomAttributesHelpers.cs" />
     <Compile Include="System\Reflection\DefaultMemberAttribute.cs" />
     <Compile Include="System\Reflection\FieldInfo.cs" />
     <Compile Include="System\Reflection\FieldReflectionAttributes.cs" />

source/nanoFramework.CoreLibrary/System/AssemblyInfo.cs

@@ -14,4 +14,4 @@
 [assembly: AssemblyProduct("nanoFramework mscorlib")]
 [assembly: AssemblyCopyright("Copyright © nanoFramework Contributors 2017")]
 
-[assembly: AssemblyNativeVersion("100.4.7.0")]
+[assembly: AssemblyNativeVersion("100.4.8.0")]

source/nanoFramework.CoreLibrary/System/Reflection/CustomAttributesHelpers.cs

@@ -0,0 +1,52 @@
+//
+// Copyright (c) 2020 The nanoFramework project contributors
+// See LICENSE file in the project root for full license information.
+//
+
+namespace System.Reflection
+{
+    internal class CustomAttributesHelpers
+    {
+        public static object[] GetCustomAttributesInternal(object[] rawAttributes)
+        {
+            // get the custom attributes data for the field
+            // these are returned "encoded" in an object array with 2 positions for each attribute
+            // 1st the attribute type
+            // 2nd the constructor parameter or null, if the attribute has no constructor
+            // 
+            // current limitations: 
+            // - works only for constructors with a single parameter
+            // - the parameter has to be a string or numeric type
+            //
+            // both limitations above can be relatively easily overcome by adding the appropriate code at the native handler
+
+            object[] attributes = new object[rawAttributes.Length / 2];
+
+            for (int i = 0; i < rawAttributes.Length; i += 2)
+            {
+                // peek next element to determine if it's null
+                if (rawAttributes[i + 1] == null)
+                {
+                    // attribute without default constructor, just copy it
+                    attributes[i / 2] = rawAttributes[i];
+                }
+                else
+                {
+                    // has default constructor, invoke it
+
+                    // get the types
+                    Type objectType = rawAttributes[i].GetType();
+                    Type paramType = rawAttributes[i + 1].GetType();
+
+                    // get constructor
+                    ConstructorInfo ctor = objectType.GetConstructor(new Type[] { paramType });
+
+                    // invoke constructor with the parameter
+                    attributes[i / 2] = ctor.Invoke(new object[] { rawAttributes[i + 1] });
+                }
+            }
+
+            return attributes;
+        }
+    }
+}

source/nanoFramework.CoreLibrary/System/Reflection/FieldInfo.cs

@@ -73,45 +73,7 @@ public abstract Type FieldType
         /// <remarks>This method ignores the inherit parameter for properties and events.</remarks>
         public override object[] GetCustomAttributes(bool inherit)
         {
-            // get the custom attributes data for the field
-            // these are returned "encoded" in an object array with 2 positions for each attribute
-            // 1st the attribute type
-            // 2nd the constructor parameter or null, if the attribute has no constructor
-            // 
-            // current limitations: 
-            // - works only for constructors with a single parameter
-            // - the parameter has to be a string or numeric type
-            //
-            // both limitations above can be relatively easily overcome by adding the appropriate code at the native handler
-            var ret = GetCustomAttributesNative(inherit);
-
-            object[] attributes = new object[ ret.Length/2 ];
-
-            for (int i = 0; i < ret.Length; i += 2)
-            {
-                // peek next element to determine if it's null
-                if(ret[ i+1 ] == null)
-                {
-                    // attribute without default constructor, just copy it
-                    attributes[ i/2 ] = ret[i];
-                }
-                else
-                {
-                    // has default constructor, invoke it
-
-                    // get the types
-                    Type objectType = ret[i].GetType();
-                    Type paramType = ret[ i+1 ].GetType();
-
-                    // get constructor
-                    ConstructorInfo ctor = objectType.GetConstructor(new Type[] { paramType });
-
-                    // invoke constructor with the parameter
-                    attributes[ i/2 ] = ctor.Invoke(new object[] { ret[ i+1 ] });
-                }
-            }
-
-            return attributes;
+            return CustomAttributesHelpers.GetCustomAttributesInternal(GetCustomAttributesNative(inherit));
         }
 
         [MethodImpl(MethodImplOptions.InternalCall)]

source/nanoFramework.CoreLibrary/System/Reflection/RuntimeMethodInfo.cs

@@ -19,9 +19,16 @@ public override extern Type ReturnType
             [MethodImpl(MethodImplOptions.InternalCall)]
             get;
         }
-        
+
+        public override object[] GetCustomAttributes(bool inherit)
+        {
+            return CustomAttributesHelpers.GetCustomAttributesInternal(GetCustomAttributesNative(inherit));
+        }
+
         [MethodImpl(MethodImplOptions.InternalCall)]
-        public override extern object[] GetCustomAttributes(bool inherit);
+#pragma warning disable S4200 // Native methods should be wrapped
+        private extern object[] GetCustomAttributesNative(bool inherit);
+#pragma warning restore S4200 // Native methods should be wrapped
     }
 }
 

source/nanoFramework.CoreLibrary/System/RuntimeType.cs

@@ -83,8 +83,15 @@ public override extern Type BaseType
         [MethodImpl(MethodImplOptions.InternalCall)]
         public override extern Type GetElementType();
 
+        public override object[] GetCustomAttributes(bool inherit)
+        {
+            return CustomAttributesHelpers.GetCustomAttributesInternal(GetCustomAttributesNative(inherit));
+        }
+
         [MethodImpl(MethodImplOptions.InternalCall)]
-        public override extern object[] GetCustomAttributes(bool inherit);
+#pragma warning disable S4200 // Native methods should be wrapped
+        private extern object[] GetCustomAttributesNative(bool inherit);
+#pragma warning restore S4200 // Native methods should be wrapped
     }
 }