Populate custom attributes on type parameters

PublicApiGenerator · Jun 30, 2019 · 4da56b1 · 4da56b1
1 parent a548b85
commit 4da56b1
Showing 1 changed file with 15 additions and 9 deletions.
diff --git a/src/PublicApiGenerator/ApiGenerator.cs b/src/PublicApiGenerator/ApiGenerator.cs
@@ -226,7 +226,7 @@ static CodeTypeDeclaration CreateTypeDeclaration(TypeDefinition publicType, stri
             if (declaration.IsInterface && publicType.BaseType != null)
                 throw new NotImplementedException("Base types for interfaces needs testing");
 
-            PopulateGenericParameters(publicType, declaration.TypeParameters);
+            PopulateGenericParameters(publicType, declaration.TypeParameters, excludeAttributes);
 
             if (publicType.BaseType != null && ShouldOutputBaseType(publicType))
             {
@@ -280,7 +280,7 @@ static CodeTypeDeclaration CreateDelegateDeclaration(TypeDefinition publicType,
 
             // CodeDOM. No support. Return type attributes.
             PopulateCustomAttributes(invokeMethod.MethodReturnType, declaration.CustomAttributes, type => ModifyCodeTypeReference(type, "return:"), excludeAttributes);
-            PopulateGenericParameters(publicType, declaration.TypeParameters);
+            PopulateGenericParameters(publicType, declaration.TypeParameters, excludeAttributes);
             PopulateMethodParameters(invokeMethod, declaration.Parameters, excludeAttributes);
 
             // Of course, CodeDOM doesn't support generic type parameters for delegates. Of course.
@@ -299,26 +299,32 @@ static bool ShouldOutputBaseType(TypeDefinition publicType)
             return publicType.BaseType.FullName != "System.Object" && publicType.BaseType.FullName != "System.ValueType";
         }
 
-        static void PopulateGenericParameters(IGenericParameterProvider publicType, CodeTypeParameterCollection parameters)
+        static void PopulateGenericParameters(IGenericParameterProvider publicType, CodeTypeParameterCollection parameters, HashSet<string> excludeAttributes)
         {
             foreach (var parameter in publicType.GenericParameters)
             {
-                if (parameter.HasCustomAttributes)
-                    throw new NotImplementedException("Attributes on type parameters is not supported. And weird");
-
                 // A little hacky. Means we get "in" and "out" prefixed on any constraints, but it's either that
-                // or add it as a custom attribute, which looks even weirder
+                // or add it as a custom attribute
                 var name = parameter.Name;
                 if (parameter.IsCovariant)
                     name = "out " + name;
                 if (parameter.IsContravariant)
                     name = "in " + name;
 
+                var attributeCollection = new CodeAttributeDeclarationCollection();
+                if (parameter.HasCustomAttributes)
+                {
+                    PopulateCustomAttributes(parameter, attributeCollection, excludeAttributes);
+                }
+
                 var typeParameter = new CodeTypeParameter(name)
                 {
                     HasConstructorConstraint =
                         parameter.HasDefaultConstructorConstraint && !parameter.HasNotNullableValueTypeConstraint
                 };
+
+                typeParameter.CustomAttributes.AddRange(attributeCollection.OfType<CodeAttributeDeclaration>().ToArray());
+
                 if (parameter.HasNotNullableValueTypeConstraint)
                     typeParameter.Constraints.Add(" struct"); // Extra space is a hack!
                 if (parameter.HasReferenceTypeConstraint)
@@ -428,7 +434,7 @@ static string ConvertAttributeToCode(Func<CodeTypeReference, CodeTypeReference>
         static bool ShouldIncludeAttribute(CustomAttribute attribute, HashSet<string> excludeAttributes)
         {
             var attributeTypeDefinition = attribute.AttributeType.Resolve();
-            return attributeTypeDefinition != null && !excludeAttributes.Contains(attribute.AttributeType.FullName) && attributeTypeDefinition.IsPublic;
+            return attributeTypeDefinition != null && !excludeAttributes.Contains(attribute.AttributeType.FullName) && (attributeTypeDefinition.IsPublic || attributeTypeDefinition.FullName == "System.Runtime.CompilerServices.NullableAttribute");
         }
 
         static CodeExpression CreateInitialiserExpression(CustomAttributeArgument attributeArgument)
@@ -558,7 +564,7 @@ static void AddMethodToTypeDeclaration(CodeTypeDeclaration typeDeclaration, Meth
                 ReturnType = returnType,
             };
             PopulateCustomAttributes(member.MethodReturnType, method.ReturnTypeCustomAttributes, excludeAttributes);
-            PopulateGenericParameters(member, method.TypeParameters);
+            PopulateGenericParameters(member, method.TypeParameters, excludeAttributes);
             PopulateMethodParameters(member, method.Parameters, excludeAttributes, IsExtensionMethod(member));
 
             typeDeclaration.Members.Add(method);