Shutdown toolset compilers (#43135)

Author: jjonescz

src/Cli/dotnet/BuildServer/VBCSCompilerServer.cs

@@ -3,12 +3,18 @@
 
 using System.Reflection;
 using Microsoft.DotNet.Cli;
+using Microsoft.DotNet.Cli.Utils;
 using Microsoft.DotNet.CommandFactory;
+using NuGet.Configuration;
 
 namespace Microsoft.DotNet.BuildServer
 {
     internal class VBCSCompilerServer : IBuildServer
     {
+        private static readonly string s_toolsetPackageName = "microsoft.net.sdk.compilers.toolset";
+        private static readonly string s_vbcsCompilerExeFileName = "VBCSCompiler.exe";
+        private static readonly string s_shutdownArg = "-shutdown";
+
         internal static readonly string VBCSCompilerPath = Path.Combine(
                 Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location),
                 "Roslyn",
@@ -28,18 +34,46 @@ public VBCSCompilerServer(ICommandFactory commandFactory = null)
 
         public void Shutdown()
         {
-            var command = _commandFactory
-                .Create("exec", new[] { VBCSCompilerPath, "-shutdown" })
-                .CaptureStdOut()
-                .CaptureStdErr();
+            List<string> errors = null;
+
+            // Shutdown the compiler from the SDK.
+            execute(_commandFactory.Create("exec", [VBCSCompilerPath, s_shutdownArg]), ref errors);
+
+            // Shutdown toolset compilers.
+            var nuGetPackageRoot = SettingsUtility.GetGlobalPackagesFolder(Settings.LoadDefaultSettings(root: null));
+            var toolsetPackageDirectory = Path.Join(nuGetPackageRoot, s_toolsetPackageName);
+            if (Directory.Exists(toolsetPackageDirectory))
+            {
+                foreach (var versionDirectory in Directory.EnumerateDirectories(toolsetPackageDirectory))
+                {
+                    var vbcsCompilerPath = Path.Join(versionDirectory, s_vbcsCompilerExeFileName);
+                    if (File.Exists(vbcsCompilerPath))
+                    {
+                        execute(CommandFactoryUsingResolver.Create(vbcsCompilerPath, [s_shutdownArg]), ref errors);
+                    }
+                }
+            }
 
-            var result = command.Execute();
-            if (result.ExitCode != 0)
+            if (errors?.Count > 0)
             {
                 throw new BuildServerException(
                     string.Format(
                         LocalizableStrings.ShutdownCommandFailed,
-                        result.StdErr));
+                        string.Join(Environment.NewLine, errors)));
+            }
+
+            static void execute(ICommand command, ref List<string> errors)
+            {
+                command = command
+                    .CaptureStdOut()
+                    .CaptureStdErr();
+
+                var result = command.Execute();
+                if (result.ExitCode != 0)
+                {
+                    errors ??= new List<string>();
+                    errors.Add(result.StdErr);
+                }
             }
         }
     }