I've been working lately on getting Moq to work on Xamarin.Android, which means getting Castle.Core to work on Xamarin.Android as well. My goal is to get my changes accepted upstream for both Castle and Moq, so I'd looking for guidance and feedback on how to organize my changes to make them acceptable.
TL;DR - Would it be acceptable to put Castle.Core's source files in a new Shared Code project (.shproj), and then reference that project in both Castle.Core and a new Castle.Core.Android project?
So far, I have Castle and Moq both building for Xamarin.Android, and Moq passes all but 2 of its unit tests now. To get to that point, however, I had to hack up Castle.Core's solution and project files to the point that they only build for Xamarin.Android.
I would use $(Configuration) or $(Platform) Condition checks to make a single .csproj work with both .NET and Xamarin.Android profiles, if that were possible. Unfortunately, the Xamarin.Android .csproj must be separate, or else Xamarin gets confused about what kind of project it is.
Since Castle.Core is not a candidate to become a PCL, my usual approach to fix this would be to create a Shared Project. It would contain all of the source files currently in Castle.Core, and then Castle.Core.csproj and Castle.Core.Android.csproj would reference that project. Adding a source file to the Shared Project would then automatically be included in both projects. A similar approach would be used for Castle.Core.Tests. This approach is easy to understand and maintain. It's only downside is that it requires at least Visual Studio 2013 Update 2 or Xamarin Studio 5.0 or later.
The alternative is ugly and unpleasant to maintain. In Castle.Core.Android.csproj, make a <Link> to every source file from Castle.Core that should be compiled in Castle.Core.Android as well. This is painful because every time a file is added/removed from Castle.Core, the link must also be added/removed in Castle.Core.Android.
Is there an alternative that I've missed?
Also, is there anything I need to account for in Settings.proj, buildscripts/Build.proj, or buildscripts/Castle.Common.Targets?