A lightweight utility library to create a Roslyn AdhocWorkspace from an existing solution/csproj, by capturing the CSharp compiler emited command while rebuilding the project. This can be used primarily for syntax tree inspection/code generation.

This library requires a dotnet SDK to be installed

// Rebuild the specified project in Release and capture
var result = CSharpCompilationCapture.Build(@"C:\Path\To\A\Sln\Or\project.csproj", "Release");
var workspace = result.Workspace;
var project = workspace.CurrentSolution.Projects.FirstOrDefault();
var compilation = await project.GetCompilationAsync();
// ...

If you have been using MSBuildWorkdspace to get an access to CSharp projects, you will find sometimes that it is actually impossible to work with if you are expecting your Roslyn application to run on a different runtime than the one currently installed through the dotnet SDK.

This is a known issue Use more permissive load context for MSBuildWorkspace by default and I hope that it will be fix in the future.

To workaround this problem and allow to load a CSharp Project with Roslyn no matter which SDK is installed, Broslyn is working like this:

• It runs a dotnet msbuild /t:rebuild on the project or solution passed to it with an output to a binlog file.
• By running the re-build, we are able to capture the exact csc command issued by the build system and we can extract them with by reading compiler invocations using the fantastic MSBuildStruturedLog library.
• We then extract the csc arguments and transform them back to CSharpCompilationArguments.
• From this we can create for each csc invocation and equivalent Roslyn Project that will guarantee the exact same compilation settings.

This was a nice suggestion from Kirill Osenkov (the author of MSBuildStruturedLog) and it turns out that it was very easy to implement.

This software is released under the BSD-Clause 2 license.

• Buildalizer: A more featured library if you are looking for a better introspection on project references and dependencies
  • In Broslyn, a Project will only contain assembly references in order to compile to CSharp but will not provide full introspection on the original project references.

Alexandre Mutel aka xoofx.