dotnet · ccastanedaucf · Dec 16, 2024
diff --git a/MSBuild.sln b/MSBuild.sln
@@ -84,6 +84,10 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.Build.BuildCheck.
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.Build.Templates", "template_feed\Microsoft.Build.Templates.csproj", "{A86EE74A-AEF0-42ED-A5A7-7A54BC0773D8}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{4D013D5D-E085-4F4F-B36B-9484F7E51657}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "RarTest", "src\RarTest\RarTest.csproj", "{20D438A5-B93B-4972-BFAD-373954BD6117}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -916,6 +920,30 @@ Global
 		{A86EE74A-AEF0-42ED-A5A7-7A54BC0773D8}.Release|x64.Build.0 = Release|Any CPU
 		{A86EE74A-AEF0-42ED-A5A7-7A54BC0773D8}.Release|x86.ActiveCfg = Release|Any CPU
 		{A86EE74A-AEF0-42ED-A5A7-7A54BC0773D8}.Release|x86.Build.0 = Release|Any CPU
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Debug|ARM64.ActiveCfg = Debug|arm64
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Debug|ARM64.Build.0 = Debug|arm64
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Debug|x64.ActiveCfg = Debug|x64
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Debug|x64.Build.0 = Debug|x64
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Debug|x86.Build.0 = Debug|Any CPU
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.MachineIndependent|Any CPU.ActiveCfg = MachineIndependent|Any CPU
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.MachineIndependent|Any CPU.Build.0 = MachineIndependent|Any CPU
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.MachineIndependent|ARM64.ActiveCfg = MachineIndependent|arm64
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.MachineIndependent|ARM64.Build.0 = MachineIndependent|arm64
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.MachineIndependent|x64.ActiveCfg = MachineIndependent|x64
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.MachineIndependent|x64.Build.0 = MachineIndependent|x64
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.MachineIndependent|x86.ActiveCfg = MachineIndependent|Any CPU
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.MachineIndependent|x86.Build.0 = MachineIndependent|Any CPU
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Release|Any CPU.Build.0 = Release|Any CPU
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Release|ARM64.ActiveCfg = Release|arm64
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Release|ARM64.Build.0 = Release|arm64
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Release|x64.ActiveCfg = Release|x64
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Release|x64.Build.0 = Release|x64
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Release|x86.ActiveCfg = Release|Any CPU
+		{20D438A5-B93B-4972-BFAD-373954BD6117}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -934,6 +962,7 @@ Global
 		{B60173F0-F9F0-4688-9DF8-9ADDD57BD45F} = {9BAD9352-DEFB-45E5-B8A4-4816B9B22A33}
 		{F47E1A0A-7D81-40CF-B8B3-A0F4B5ADE943} = {760FF85D-8BEB-4992-8095-A9678F88FD47}
 		{71E59632-D644-491B-AF93-22BC93167C56} = {9BAD9352-DEFB-45E5-B8A4-4816B9B22A33}
+		{20D438A5-B93B-4972-BFAD-373954BD6117} = {4D013D5D-E085-4F4F-B36B-9484F7E51657}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {F948D667-14E3-4F98-BA50-3F3C948BF4C2}

@@ -20,6 +20,7 @@
     <PackageVersion Include="System.Collections.Immutable" Version="$(SystemCollectionsImmutableVersion)" />
     <PackageVersion Include="System.Configuration.ConfigurationManager" Version="$(SystemConfigurationConfigurationManagerVersion)" />
     <PackageVersion Include="System.Formats.Asn1" Version="$(SystemFormatsAsn1Version)" />
+    <PackageVersion Include="System.IO.Hashing" Version="$(SystemIOHashingVersion)" />
     <PackageVersion Include="System.Memory" Version="$(SystemMemoryVersion)" />
     <PackageVersion Include="System.Net.Http" Version="$(SystemNetHttpVersion)" />
     <PackageVersion Include="System.Reflection.Metadata" Version="$(SystemReflectionMetadataVersion)" />

@@ -32,6 +32,7 @@
         When updating the version of System.Memory file a breaking change here: https://github.com/dotnet/docs/issues/new?assignees=gewarren&labels=breaking-change%2CPri1%2Cdoc-idea&template=breaking-change.yml&title=%5BBreaking+change%5D%3A+
         and follow the guidelines written here (internal-link): https://dev.azure.com/devdiv/DevDiv/_wiki/wikis/DevDiv.wiki/1796/How-to-add-a-Known-Issue
     -->
+    <SystemIOHashingVersion>8.0.0</SystemIOHashingVersion>
     <SystemMemoryVersion>4.5.5</SystemMemoryVersion>
     <SystemNetHttpVersion>4.3.4</SystemNetHttpVersion>
     <SystemReflectionMetadataLoadContextVersion>8.0.0</SystemReflectionMetadataLoadContextVersion>

diff --git a/src/Build/BackEnd/Components/Communications/RarNodeLauncher.cs b/src/Build/BackEnd/Components/Communications/RarNodeLauncher.cs
@@ -0,0 +1,77 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.IO.Pipes;
+using System.Linq;
+using System.Security.Principal;
+using System.Threading;
+using Microsoft.Build.BackEnd;
+using Microsoft.Build.Framework;
+using Microsoft.Build.Framework.Telemetry;
+using Microsoft.Build.Internal;
+using Microsoft.Build.Shared;
+
+namespace Microsoft.Build.BackEnd.Client
+{
+    public sealed class RarNodeLauncher
+    {
+        public static void LaunchServer()
+        {
+            CommunicationsUtilities.Trace("Checking for RAR server...");
+            RarNodeHandshake handshake = new(HandshakeOptions.None);
+
+            if (IsPipeExists(handshake))
+            {
+                CommunicationsUtilities.Trace($"Existing RAR server found.");
+                return;
+            }
+
+            string serverLaunchMutexName = $@"Global\msbuild-rar-server-launch-{handshake.ComputeHash()}";
+
+            // Then, check if another MSBuild process has started the server launch.
+            // This accounts for any delay between the server starting and opening its mutex.
+            using Mutex serverLaunchMutex = new(
+                initiallyOwned: true,
+                name: serverLaunchMutexName,
+                createdNew: out bool createdNew);
+
+            if (!createdNew)
+            {
+                CommunicationsUtilities.Trace("Another process launching the RAR server.");
+                return;
+            }
+
+            CommunicationsUtilities.Trace("Starting Server...");
+
+            string msbuildLocation = BuildEnvironmentHelper.Instance.CurrentMSBuildExePath;
+            string commandLineArgs = string.Join(" ", ["/nologo", "/nodemode:3"]);
+
+            NodeLauncher nodeLauncher = new();
+            Process msbuildProcess = nodeLauncher.Start(msbuildLocation, commandLineArgs, nodeId: 0);
+
+            CommunicationsUtilities.Trace("RAR Server started with PID: {0}", msbuildProcess.Id);
+        }
+
+        private static bool IsPipeExists(RarNodeHandshake handshake)
+        {
+            string[] pipes = Directory.GetFiles(@"\\.\pipe\");
+
+            return pipes.Contains(Path.Combine(@"\\.\pipe\", $"msbuild-rar-{handshake.ComputeHash()}"));
+        }
+
+        private static bool IsServerRunning(ServerNodeHandshake handshake)
+        {
+            string serverRunningMutexName = $@"Global\msbuild-rar-server-running-{handshake.ComputeHash()}";
+
+            // First, check if the server has created the mutex.
+            // Use a mutex to avoid using a timeout or checking a max pipe instance exception.
+            bool isRunning = Mutex.TryOpenExisting(serverRunningMutexName, out Mutex? mutex);
+            mutex?.Dispose();
+
+            return isRunning;
+        }
+    }
+}
diff --git a/src/Build/Microsoft.Build.csproj b/src/Build/Microsoft.Build.csproj
@@ -147,6 +147,7 @@
     <Compile Include="BackEnd\Components\ProjectCache\*.cs" />
     <Compile Include="BackEnd\Components\Communications\CurrentHost.cs" />
     <Compile Include="BackEnd\Components\Communications\DetouredNodeLauncher.cs" />
+    <Compile Include="BackEnd\Components\Communications\RarNodeLauncher.cs" />
     <Compile Include="BackEnd\Components\Communications\SerializationContractInitializer.cs" />
     <Compile Include="BackEnd\Components\Communications\ServerNodeEndpointOutOfProc.cs" />
     <Compile Include="BackEnd\Components\FileAccesses\IFileAccessManager.cs" />

diff --git a/src/Framework/Traits.cs b/src/Framework/Traits.cs
@@ -127,6 +127,11 @@ public Traits()
         /// </summary>
         public const string UseMSBuildServerEnvVarName = "MSBUILDUSESERVER";
 
+        /// <summary>
+        /// Internally set if ResolveAssemblyReference tasks should forward requests to the out-of-proc node.
+        /// </summary>
+        public const string ExecuteRAROutOFProcessEnvVarName = "MSBUILDEXECUTERAROUTOFPROC";
+
         public readonly bool DebugEngine = !string.IsNullOrEmpty(Environment.GetEnvironmentVariable("MSBuildDebugEngine"));
         public readonly bool DebugScheduler;
         public readonly bool DebugNodeCommunication;

diff --git a/src/MSBuild.UnitTests/CommandLineSwitches_Tests.cs b/src/MSBuild.UnitTests/CommandLineSwitches_Tests.cs
@@ -1186,6 +1186,7 @@ public void InvalidToolsVersionErrors()
                                         lowPriority: false,
                                         question: false,
                                         isBuildCheckEnabled: false,
+                                        enableRarService: false,
                                         inputResultsCaches: null,
                                         outputResultsCache: null,
                                         saveProjectResult: false,

diff --git a/src/MSBuild/CommandLineSwitches.cs b/src/MSBuild/CommandLineSwitches.cs
@@ -120,6 +120,7 @@ internal enum ParameterizedSwitch
             GetTargetResult,
             GetResultOutputFile,
             FeatureAvailability,
+            EnableRarService,
             // This has to be kept as last enum value
             NumberOfParameterizedSwitches,
         }
@@ -296,6 +297,7 @@ internal ParameterizedSwitchInfo(
             new ParameterizedSwitchInfo(  ["getItem"],                           ParameterizedSwitch.GetItem,                    null,                           true,           "MissingGetItemError",                 true,   false,   "HelpMessage_44_GetItemSwitch"),
             new ParameterizedSwitchInfo(  ["getTargetResult"],                   ParameterizedSwitch.GetTargetResult,            null,                           true,           "MissingGetTargetResultError",         true,   false,   "HelpMessage_45_GetTargetResultSwitch"),
             new ParameterizedSwitchInfo(  ["getResultOutputFile"],               ParameterizedSwitch.GetResultOutputFile,        null,                           true,           "MissingGetResultFileError",           true,   false,   "HelpMessage_51_GetResultOutputFileSwitch"),
+            new ParameterizedSwitchInfo(  ["enableRarService"],                  ParameterizedSwitch.EnableRarService,           null,                           true,            null,                                 true,   false,   "HelpMessage_53_EnableRarServiceSwitch"),
             new ParameterizedSwitchInfo(  ["featureAvailability", "fa"],         ParameterizedSwitch.FeatureAvailability,        null,                           true,           "MissingFeatureAvailabilityError",     true,   false,   "HelpMessage_46_FeatureAvailabilitySwitch")
         };
 

diff --git a/src/MSBuild/MSBuild/Microsoft.Build.CommonTypes.xsd b/src/MSBuild/MSBuild/Microsoft.Build.CommonTypes.xsd
@@ -3322,6 +3322,7 @@ elementFormDefault="qualified">
                     <xs:attribute name="ProfileName" />
                     <xs:attribute name="PublicKeysRestrictedForGlobalLocation" />
                     <xs:attribute name="SearchPaths" use="required" />
+                    <xs:attribute name="ShouldExecuteInProcess" type="msb:boolean" />
                     <xs:attribute name="Silent" type="msb:boolean" />
                     <xs:attribute name="StateFile" />
                     <xs:attribute name="TargetedRuntimeVersion" />

diff --git a/src/MSBuild/Resources/Strings.resx b/src/MSBuild/Resources/Strings.resx
@@ -1052,6 +1052,18 @@
       LOCALIZATION: None of the lines should be longer than a standard width console window, eg 80 chars.
     </comment>
   </data>
+  <data name="HelpMessage_53_EnableRarServiceSwitch" xml:space="preserve">
+    <value>  -rarService[:True|False]
+                     Causes MSBuild to run a persistent service for the ResolveAssemblyReference task.
+
+                     This flag is experimental and may not work as intended.
+    </value>
+    <comment>
+      LOCALIZATION: "MSBuild" should not be localized.
+      LOCALIZATION: "-rarService" should not be localized.
+      LOCALIZATION: None of the lines should be longer than a standard width console window, eg 80 chars.
+    </comment>
+  </data>
   <data name="InvalidConfigurationFile" xml:space="preserve">
     <value>MSBUILD : Configuration error MSB1043: The application could not start. {0}</value>
     <comment>
@@ -1496,6 +1508,14 @@
       LOCALIZATION: The prefix "MSBUILD : error MSBxxxx:" should not be localized.
     </comment>
   </data>
+  <data name="InvalidRarServiceValue" xml:space="preserve">
+    <value>MSBUILD : error MSB1069: Enable RAR service value is not valid. {0}.</value>
+    <comment>{StrBegin="MSBUILD : error MSB1069: "}
+     UE: This message does not need in-line parameters because the exception takes care of displaying the invalid arg.
+     This error is shown when a user specifies a node reuse value that is not equivilant to Boolean.TrueString or Boolean.FalseString.
+     LOCALIZATION: The prefix "MSBUILD : error MSBxxxx:" should not be localized.
+  </comment>
+  </data>
   <data name="InvalidPreprocessPath" xml:space="preserve">
     <value>MSBUILD : error MSB1047: File to preprocess to is not valid. {0}</value>
     <comment>{StrBegin="MSBUILD : error MSB1047: "}</comment>
@@ -1812,7 +1832,7 @@
     <!--
         The command line message bucket is: MSB1001 - MSB1999
 
-        Next error code should be MSB1069.
+        Next error code should be MSB1070.
 
         Don't forget to update this comment after using the new code.
   -->

diff --git a/src/MSBuild/Resources/xlf/Strings.cs.xlf b/src/MSBuild/Resources/xlf/Strings.cs.xlf
diff --git a/src/MSBuild/Resources/xlf/Strings.de.xlf b/src/MSBuild/Resources/xlf/Strings.de.xlf