In Quick Info, only ObsoleteAttribute is being displayed

[dsaf]

Demonstration:

1. copy-paste:

    public class SampleUsage : SampleBase
    {
        void SampleMethodUsage()
        {
            var sampleEnumUsage = SampleEnum.One;

            SampleMethod(sampleEnumUsage);
        }
    }

    [Obsolete("asdasd"), Serializable, SampleAttribute]
    public abstract class SampleBase
    {
        [Obsolete, Conditional("DEBUG")]
        protected void SampleMethod(SampleEnum sample) {}
    }

    [Obsolete, Serializable, CLSCompliant(true), Flags]
    public enum SampleEnum
    {
        [Obsolete]
        One,
        Two,
        Thee
    }

    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true, Inherited = true)]
    public class SampleAttributeAttribute : Attribute
    {
    }

2. in SampleUsage hover mouse over: SampleBase, SampleEnum, SampleMethod
3. observe that only ObsoleteAttribute is being displayed

Issues:

1. it makes a developer incorrectly assume that this is the only attribute applied or relevant
2. creates a disparity between core platform and third-party developers in terms of IDE API treatment

Resolutions:

1. quick fix: either hide or show all custom attributes (including inherited!)
2. proper fix: show complete attribute information including non-default attribute arguments

[dsaf]

Relevant: #780 , #711 , #534

[Pilchie]

This is our intended design. The Obsolete attribute is special because it affects compilation and causes errors.

[dsaf]

"The Obsolete attribute is special because it affects compilation and causes errors."

Same can be said about this one:

https://msdn.microsoft.com/en-us/library/system.diagnostics.conditionalattribute%28v=vs.110%29.aspx

"Indicates to compilers that a method call or attribute should be ignored unless a specified conditional compilation symbol is defined."

... and these:

http://research.microsoft.com/en-us/projects/contracts

I don't think Obsolete is really special, it was just chosen to be. Wouldn't it better to be consistent?