Update LanguageServerHost to use NamedPipe

src/Features/LanguageServer/Microsoft.CodeAnalysis.LanguageServer/Program.cs

@@ -5,11 +5,11 @@
 using System.Collections.Immutable;
 using System.CommandLine;
 using System.Diagnostics;
+using System.IO.Pipes;
 using System.Runtime.InteropServices;
 using Microsoft.CodeAnalysis.Contracts.Telemetry;
 using Microsoft.CodeAnalysis.LanguageServer;
 using Microsoft.CodeAnalysis.LanguageServer.BrokeredServices;
-using Microsoft.CodeAnalysis.LanguageServer.BrokeredServices.Services.HelloWorld;
 using Microsoft.CodeAnalysis.LanguageServer.HostWorkspace;
 using Microsoft.CodeAnalysis.LanguageServer.LanguageServer;
 using Microsoft.CodeAnalysis.LanguageServer.Logging;
@@ -44,7 +44,7 @@ static async Task RunAsync(ServerConfiguration serverConfiguration, Cancellation
             LoggerFactory.Create(builder =>
             {
                 builder.SetMinimumLevel(serverConfiguration.MinimumLogLevel);
-                builder.AddConsole(options => options.LogToStandardErrorThreshold = LogLevel.Trace);
+                builder.AddConsole();
                 // The console logger outputs control characters on unix for colors which don't render correctly in VSCode.
                 builder.AddSimpleConsole(formatterOptions => formatterOptions.ColorBehavior = LoggerColorBehavior.Disabled);
             })
@@ -100,7 +100,11 @@ static async Task RunAsync(ServerConfiguration serverConfiguration, Cancellation
     // TODO: Remove, the path should match exactly. Workaround for https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1830914.
     Microsoft.CodeAnalysis.EditAndContinue.EditAndContinueMethodDebugInfoReader.IgnoreCaseWhenComparingDocumentNames = Path.DirectorySeparatorChar == '\\';
 
-    var server = new LanguageServerHost(Console.OpenStandardInput(), Console.OpenStandardOutput(), exportProvider, loggerFactory.CreateLogger(nameof(LanguageServerHost)));
+    // Named pipe server is actually created from the client, so here we create a client stream.
+    var pipeServer = new NamedPipeClientStream(serverName: ".", GetPlatformPipeConnectionString(serverConfiguration.PipeName), PipeDirection.InOut, PipeOptions.CurrentUserOnly);
+    await pipeServer.ConnectAsync(cancellationToken);
+
+    var server = new LanguageServerHost(pipeServer, pipeServer, exportProvider, loggerFactory.CreateLogger(nameof(LanguageServerHost)));
     server.Start();
 
     try
@@ -171,6 +175,12 @@ static CliRootCommand CreateCommandLineParser()
         Required = false
     };
 
+    var pipeNameOption = new CliOption<string>("--pipe")
+    {
+        Description = "The name of the pipe to use for RPC with the parent process.",
+        Required = true
+    };
+
     var rootCommand = new CliRootCommand()
     {
         debugOption,
@@ -181,7 +191,8 @@ static CliRootCommand CreateCommandLineParser()
         sessionIdOption,
         sharedDependenciesOption,
         extensionAssemblyPathsOption,
-        extensionLogDirectoryOption
+        extensionLogDirectoryOption,
+        pipeNameOption
     };
     rootCommand.SetAction((parseResult, cancellationToken) =>
     {
@@ -193,6 +204,7 @@ static CliRootCommand CreateCommandLineParser()
         var sharedDependenciesPath = parseResult.GetValue(sharedDependenciesOption);
         var extensionAssemblyPaths = parseResult.GetValue(extensionAssemblyPathsOption) ?? Array.Empty<string>();
         var extensionLogDirectory = parseResult.GetValue(extensionLogDirectoryOption)!;
+        var pipe = parseResult.GetValue(pipeNameOption)!;
 
         var serverConfiguration = new ServerConfiguration(
             LaunchDebugger: launchDebugger,
@@ -202,11 +214,28 @@ static CliRootCommand CreateCommandLineParser()
             SessionId: sessionId,
             SharedDependenciesPath: sharedDependenciesPath,
             ExtensionAssemblyPaths: extensionAssemblyPaths,
-            ExtensionLogDirectory: extensionLogDirectory);
+            ExtensionLogDirectory: extensionLogDirectory,
+            PipeName: pipe);
 
         return RunAsync(serverConfiguration, cancellationToken);
     });
 
     return rootCommand;
 }
 
+static string GetPlatformPipeConnectionString(string pipeName)
+{
+    var isWindows = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
+    if (isWindows)
+    {
+        return @"\\.\" + pipeName;
+    }
+    else
+    {
+        // For Linux-type systems, the "pipe" is actually a shared file.
+        // Point to the same file as on the client
+        var pipeFile = pipeName + ".sock";
+        return Path.Combine(Path.GetTempPath(), pipeFile);
+    }
+}
+

src/Features/LanguageServer/Microsoft.CodeAnalysis.LanguageServer/ServerConfigurationFactory.cs

@@ -49,4 +49,5 @@ internal record class ServerConfiguration(
     string? SessionId,
     string? SharedDependenciesPath,
     IEnumerable<string> ExtensionAssemblyPaths,
-    string ExtensionLogDirectory);
+    string ExtensionLogDirectory,
+    string PipeName);