stackalloc for reference types with Roslyn and CoreCLR

This repository contains the prototype used in the post A new stackalloc operator for reference types with CoreCLR and Roslyn

Content

It contains:

• A fork of the CoreCLR project from the branch stackalloc_for_class
• A fork of Roslyn project from the branch stackalloc_for_class
• A project StackAllocForClass using the new keyword transient and stackalloc

How to Build?

Make sure that all submodules are correctly initialized when cloning this repository.

Building CoreCLR

The official instructions are here.

But using this simple steps should work:

• Install CMake for Windows.
• Add it to the PATH environment variable.
• Open a VS2015 command prompt, go to the folder coreclr and type: build skiptestbuild

Building Roslyn

The official build instructions are here

• Open a VS2015 command prompt, go to the folder roslyn
• Run: nuget.exe restore Roslyn.sln
• Open the solution Roslyn.sln
• Compile the full solution (in debug mode)

How to Test?

• Open a VS2015 command prompt
• Run: devenv.exe /rootSuffix Roslyn (Note that syntax analysis in VS doesn't use the new Roslyn, haven't dig enough why...)
• This will start a VS2015 with the C# compiler using the version compiled previously.
• Open the project StackAllocForClass.sln and build the project
• Back to the command prompt, go to the output bin folder StackAllocForClass\bin\Debug

If you run this command, it will use the version using stackalloc operator:

• ..\..\..\coreclr\bin\Product\Windows_NT.x64.Debug\CoreRun.exe StackAllocForClass.exe

You should get the following output:

Mode: StackAlloc . To switch to HeapAlloc, simply pass an argument to this exe
[before] GC gen0 collect: 0
[before] GC gen1 collect: 0
[before] GC gen2 collect: 0
Result: -729545010
[after] GC gen0 collect: 0
[after] GC gen1 collect: 0
[after] GC gen2 collect: 0
Elapsed: 418.9245ms

Passing a single parameter will switch to heap mode:

• ..\..\..\coreclr\bin\Product\Windows_NT.x64.Debug\CoreRun.exe StackAllocForClass.exe 1

In heap mode:

Mode: HeapAlloc
[before] GC gen0 collect: 0
[before] GC gen1 collect: 0
[before] GC gen2 collect: 0
Result: -729545010
[after] GC gen0 collect: 114
[after] GC gen1 collect: 0
[after] GC gen2 collect: 0
Elapsed: 4984.224ms

License

Same license as CoreCLR and Roslyn.

Author

Alexandre Mutel aka @xoofx