Default Interface Method support

[yizhang82]

C# Language Spec Link Runtime Spec Link (TBD)

List of work items:

• [x] Fix up ILDAsm to support default interface methods (non-abstract virtual methods) on interfaces
• [x] Fix up ILDAsm to allow non-virtual instance methods on interface
• [x] Allow type loader to ignore not implemented interface methods on classes
• [x] Allow non-virtual interface instance methods in type loader
• [x] Support calling protected interface non-virtual instance method from derived class (TBD)
• [x] Hook up VSD interface dispatch
• [x] Throw in the case of diamond inheritance case
• [x] Support Shared generics and variance
• [x] Support looking up method impls
• [ ] Static constructors with initializers only (no static constructor by itself - needs more investigation)
• [ ] Support constrained interface call on value types
• [x] Handle interface precodes properly
• [x] Correct interface lookup algorithm (and validation) once design is finalized
• [x] Proper typeloader/ILDAsm error checking/validation for interface methods once design is finalized (private/protected/internal, virtual vs non-virtual)
• [ ] Reflection to tell the difference between default interface method and a regular
• [ ] NGEN support
• [x] R2R support
• [ ] Interaction with COM interop

[gkhanna79]

@yizhang82 Is this for .NET Core 2.0?

[yizhang82]

No. It's not part of .NET Core 2.0 work. I don't think we have a shipping date yet. Right now we are in early design/prototype phase.

[yizhang82]

We also need engineering work to support producing packages for Roslyn CI. Tracked here: https://github.com/dotnet/core-eng/issues/833

[mattwarren]

Tracked here: dotnet/core-eng#833

Just one thing, that 'core-eng' repo doesn't appear to be publicly accessible.

I'm not saying it should be, but I just wanted to let you know that anyone who isn't a M/S employee can't see that link you posted.

[MichalStrehovsky]

Broken out the remaining tasks into individual issues and now tracking within the Default interfaces project.