Bring CoreRT and CoreCLR's CoreLibs into sync

[danmoseley]

We want to do this to (1) get code formatting from CoreRT (2) get bug fixes and new API to CoreRT so they reach UWP.

• Rename coreclr\src\mscorlib\corefx to coreclr\src\mscorlib\shared
• Renames in CoreCLR to bring directories and files to match CoreRT eg
  rename coreclr\src\mscorlib to coreclr\src\System.Private.CoreLib
• Update CoreCLR corelib's resource generation: change from .txt to .resx and autogenerate the SR.cs
• A lot of places in CoreCLR CoreLib use "ThrowHelper" class. ThrowHelper does not work well with ProjectN toolchain because of its use of reflection. Find a way to how to unify these. The ideal solution would be IL-to-IL optimizer that does the ThrowHelper optimization everywhere (see Proposal: IL optimization step roslyn#15929 (comment)).
• Take chunks of CoreRT, merge with CoreCLR and commit to CoreCLR then turn around and commit same to CoreRT.
• As part of the merging process or separately, segregate the files into folders like private and shared where private are those that call into the runtime or are closely connected and shared are those the former merely depend on. Other runtimes will likely only care about shared. This will need some exploration.
• Add automatic mirror of the shared part between CoreCLR and CoreRT. The idea is to use similar setup to what we have been using to mirror between TFS and github

Some of this was already done --

dotnet/coreclr#9259
dotnet/coreclr#9251

Edit: changed folder name from core to private

[weshaggard]

Do we plan to try and share the source via submoduling or some other technique?

[jkotas]

coreclr\src\System.Private.CoreLib\corert

This may rather be coreclr\src\System.Private.CoreLib\shared as we have discussed

[danmoseley]

Added a checkbox for that segregation.

[jkotas]

folders like core and

Yet another core ... we are ~42 core project :-) Maybe call it unshared or exclusive?

[alexperovich]

I have the shared portions of coreclr and corert synchronized and my synching tool is now running to keep those directories in sync.

[karelz]

Is it rather 2.1 issue than 2.0?

[danmoseley]

Work continues on this and much progress was made; however it is not aligned with 2.1 per se.

[danmoseley]

@jkotas

A lot of places in CoreCLR CoreLib use "ThrowHelper" class. ThrowHelper does not work well with ProjectN toolchain because of its use of reflection.

I am looking in C:\git\coreclr\src\mscorlib\src\System\ThrowHelper.cs and I do not see reflection. Where am I missing?

[danmoseley]

@jkotas do you still think it is worth renaming coreclr\src\mscorlib to coreclr\src\System.Private.CoreLib ? That seems like the only remaining rename.

[jkotas]

I do not see reflection

Enum.ToString is reflection call.

[danmoseley]

Hmm, there is certainly plenty more reconciliation (merge and move to shared) that can be done between
C:\git\corert\src\system.private.corelib\src C:\git\coreclr\src\mscorlib\src
although most of it is no longer trivial and would be best attempted with domain knowledge there is some more cosmetic/easier merging that could be done.

[jkotas]

There is certainly plenty more reconciliation

Yes, about ~100 files.

Here is the list I got from @marek-safar that the Mono team would love to see reconciled to make their sharing with Mono easier:

src/System/Array.cs
src/System/Collections/Generic/ArraySortHelper.cs
src/System/Globalization/GlobalizationMode.cs
src/System/Runtime/CompilerServices/TaskAwaiter.cs
src/System/Threading/Tasks/TaskFactory.cs
src/System/Threading/Tasks/FutureFactory.cs
src/System/Threading/Tasks/TaskScheduler.cs
src/System/Threading/Tasks/Task.cs
src/System/Threading/Tasks/Future.cs
src/System/Threading/Tasks/TaskContinuation.cs
src/System/Threading/Tasks/ThreadPoolTaskScheduler.cs

[jkotas]

you still think it is worth renaming coreclr\src\mscorlib to coreclr\src\System.Private.CoreLib

I think it would make sense. The mscorlib name is confusing.