[MSBuild Host] Remove dependency on System.CommandLine

src/Workspaces/MSBuild/BuildHost/Microsoft.CodeAnalysis.Workspaces.MSBuild.BuildHost.csproj

@@ -43,7 +43,6 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.Build.Locator" PrivateAssets="All" />
-    <PackageReference Include="System.CommandLine" />
     <PackageReference Include="System.Collections.Immutable" />
     <PackageReference Include="Newtonsoft.Json" />
     <PackageReference Include="Microsoft.IO.Redist" Condition="'$(TargetFrameworkIdentifier)' != '.NETCoreApp'" />

src/Workspaces/MSBuild/BuildHost/Program.cs

@@ -3,8 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Collections.Immutable;
-using System.CommandLine;
 using System.Globalization;
 using System.IO.Pipes;
 using System.Threading.Tasks;
@@ -13,28 +11,27 @@ namespace Microsoft.CodeAnalysis.MSBuild;
 
 internal static class Program
 {
-    internal static async Task Main(string[] args)
+    internal static async Task<int> Main(string[] args)
     {
         // Note: we should limit the data passed through via command line strings, and pass information through IBuildHost.ConfigureGlobalState whenever possible.
         // This is because otherwise we might run into escaping issues, or command line length limits.
 
-        var pipeOption = new Option<string>("--pipe") { Required = true };
-        var localeOption = new Option<string>("--locale") { Required = true };
-        var command = new RootCommand { pipeOption, localeOption };
-        var parsedArguments = command.Parse(args);
-        var pipeName = parsedArguments.GetValue(pipeOption)!;
-        var locale = parsedArguments.GetValue(localeOption)!;
-
         var logger = new BuildHostLogger(Console.Error);
 
+        if (args is not [var pipeName, var cultureName])
+        {
+            logger.LogCritical($"Expected arguments: <pipe name> <culture>");
+            return -1;
+        }
+
         try
         {
-            CultureInfo.CurrentUICulture = CultureInfo.GetCultureInfo(locale);
+            CultureInfo.CurrentUICulture = CultureInfo.GetCultureInfo(cultureName);
         }
         catch (CultureNotFoundException)
         {
             // We couldn't find the culture, log a warning and fallback to the OS configured value.
-            logger.LogWarning($"Culture {locale} was not found, falling back to OS culture");
+            logger.LogWarning($"Culture '{cultureName}' was not found, falling back to OS culture");
         }
 
         logger.LogInformation($"BuildHost Runtime Version: {System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription}");
@@ -50,5 +47,7 @@ internal static async Task Main(string[] args)
         await server.RunAsync().ConfigureAwait(false);
 
         logger.LogInformation("RPC channel closed; process exiting.");
+
+        return 0;
     }
 }

src/Workspaces/MSBuild/Core/MSBuild/BuildHostProcessManager.cs

@@ -316,10 +316,7 @@ private static string GetBuildHostPath(string contentFolderName, string assembly
 
     private static void AppendBuildHostCommandLineArgumentsAndConfigureProcess(ProcessStartInfo processStartInfo, string pipeName)
     {
-        AddArgument(processStartInfo, "--pipe");
         AddArgument(processStartInfo, pipeName);
-
-        AddArgument(processStartInfo, "--locale");
         AddArgument(processStartInfo, System.Globalization.CultureInfo.CurrentUICulture.Name);
 
         // MSBUILD_EXE_PATH is read by MSBuild to find related tasks and targets. We don't want this to be inherited by our build process, or otherwise

src/Workspaces/MSBuild/Test/BuildHostProcessManagerTests.cs

@@ -4,6 +4,7 @@
 
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Linq;
 using Moq;
 using Roslyn.Test.Utilities;
 using Xunit;
@@ -63,14 +64,15 @@ internal void ProcessStartInfo_PassesPipeName(BuildHostProcessKind buildHostKind
         const string PipeName = "TestPipe";
 
         var processStartInfo = BuildHostProcessManager.CreateBuildHostStartInfo(buildHostKind, PipeName, dotnetPath: null);
-
 #if NET
-        var binlogIndex = processStartInfo.ArgumentList.IndexOf("--pipe");
-        Assert.True(binlogIndex >= 0);
-        Assert.Equal(PipeName, processStartInfo.ArgumentList[binlogIndex + 1]);
+        var args = processStartInfo.ArgumentList;
 #else
-        Assert.Contains($"--pipe {PipeName}", processStartInfo.Arguments);
+        var args = processStartInfo.Arguments.Split(' ');
 #endif
+        Assert.True(args.Count() >= 2, $"Expected at least 2 args: '{string.Join(",", args)}'");
+
+        Assert.Equal(PipeName, args[^2]);
+        Assert.Equal(System.Globalization.CultureInfo.CurrentUICulture.Name, args[^1]);
     }
 
     [Theory]
@@ -80,16 +82,17 @@ internal void ProcessStartInfo_PassesPipeName(BuildHostProcessKind buildHostKind
     [UseCulture("de-DE", "de-DE")]
     internal void ProcessStartInfo_PassesLocale(BuildHostProcessKind buildHostKind)
     {
-        const string Locale = "de-DE";
-
-        var processStartInfo = BuildHostProcessManager.CreateBuildHostStartInfo(buildHostKind, pipeName: "", dotnetPath: null);
+        const string PipeName = "TestPipe";
 
+        var processStartInfo = BuildHostProcessManager.CreateBuildHostStartInfo(buildHostKind, PipeName, dotnetPath: null);
 #if NET
-        var localeIndex = processStartInfo.ArgumentList.IndexOf("--locale");
-        Assert.True(localeIndex >= 0);
-        Assert.Equal(Locale, processStartInfo.ArgumentList[localeIndex + 1]);
+        var args = processStartInfo.ArgumentList;
 #else
-        Assert.Contains($"--locale {Locale}", processStartInfo.Arguments);
+        var args = processStartInfo.Arguments.Split(' ');
 #endif
+        Assert.True(args.Count() >= 2, $"Expected at least 2 args: '{string.Join(",", args)}'");
+
+        Assert.Equal(PipeName, args[^2]);
+        Assert.Equal("de-DE", args[^1]);
     }
 }