Implement IBuildProvider so that the BuildXL Integration VS extension can intercept SDK-style csproj builds

The BuildXL Integration VS extension intercepts non-SDK-style csproj builds. However, that mechanism does not work for SDK-style csproj builds. Per SharePoint Online's request, the Visual Studio team has designed a new interface IBuildProvider. See the email for more details - [SharePoint, BuildXL and SDK Style projects.pdf](https://dev.azure.com/mseng/9ed2c125-1cd5-4a17-886b-9d267f3a5fab/_apis/git/repositories/50d331c7-ea65-45eb-833f-0303c6c2387e/pullRequests/658304/attachments/SharePoint%2C%20BuildXL%20and%20SDK%20Style%20projects.pdf).

Private/InternalSdk/Microsoft.VisualStudio.ProjectSystem/Microsoft.VisualStudio.ProjectSystem.dsc

@@ -0,0 +1,26 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+import {Transformer} from "Sdk.Transformers";
+import * as Managed from "Sdk.Managed";
+
+// This is an empty facade for a Microsoft internal package.
+
+namespace Contents {
+    export declare const qualifier: {
+    };
+
+    @@public
+    export const all: StaticDirectory = Transformer.sealPartialDirectory(d`.`, []);
+}
+
+@@public
+export const pkg: Managed.ManagedNugetPackage =
+    Managed.Factory.createNugetPackage(
+        "Microsoft.VisualStudio.ProjectSystem",
+        "0.0.0",
+        Contents.all,
+        [],
+        [],
+        []
+    );

Private/InternalSdk/Microsoft.VisualStudio.ProjectSystem/module.config.dsc

@@ -0,0 +1,6 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+module({
+    name: "Microsoft.VisualStudio.ProjectSystem"
+});

Public/Src/IDE/VsIntegration/BuildXLVsPackage/extension.vsixmanifest

@@ -1,6 +1,6 @@
 <PackageManifest Version="2.0.0" xmlns="http://schemas.microsoft.com/developer/vsx-schema/2011">
   <Metadata>
-    <Identity Id="76439c3a-9faf-4f38-9f54-f127e9be9171" Version="3.2" Language="en-US" Publisher="Microsoft" />
+    <Identity Id="76439c3a-9faf-4f38-9f54-f127e9be9171" Version="3.3" Language="en-US" Publisher="Microsoft" />
     <DisplayName>BuildXL Integration</DisplayName>
     <Description>Enables using BuildXL as the build engine for Visual Studio.</Description>
     <MoreInfo>https://github.com/Microsoft/BuildXL</MoreInfo>

Public/Src/IDE/VsIntegration/BuildXLVsPackageShared/Constants.cs

@@ -49,6 +49,7 @@ namespace BuildXL.VsPackage
         internal const string DominoPackageDir = "DominoPackageDir";
 
         internal const string DominoBuildFilterProp = "DominoBuildFilter";
+        internal const string CombinedDominoBuildFilterProp = "CombinedDominoBuildFilter";
         internal const string DominoSpecFileProp = "DominoSpecFile";
 
         internal const string DominoSolutionSettingsFileExtension = ".sln.dvs.props";

Public/Src/IDE/VsIntegration/BuildXLVsPackageShared/VsProject/BuildProvider.cs

@@ -0,0 +1,156 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+#nullable enable
+
+using System.Collections.Immutable;
+using System.ComponentModel.Composition;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Build.Execution;
+using Microsoft.VisualStudio.ProjectSystem;
+using Microsoft.VisualStudio.ProjectSystem.Build;
+using Microsoft.VisualStudio.ProjectSystem.VS.Build;
+
+namespace BuildXL.VsPackage.VsProject
+{
+    /// <summary>
+    /// Proffers the BuildXL BuildProvider which intercepts the SDK-style project build requests
+    /// and routes them to the BuildXL build manager.
+    /// </summary>
+    // Visual Studio will be able to discover this IBuildProvider thanks to this attribute together with
+    // the Microsoft.VisualStudio.MefComponent asset type declared in the extension.vsixmanifest.
+    [Export(typeof(IBuildProvider))]
+    // This IBuildProvider only applies to the .csproj that has the <ProjectCapability Include="BuildXL" /> item.
+    [AppliesTo("BuildXL")]
+    // 0 is the order of the default build provider implemented by CPS.
+    // Using any number greater than 0 means overriding the default.
+    [Order(1000, SuppressLowerPriority = true)]
+    public sealed class BuildProvider : IBuildProvider
+    {
+        private static BuildManager? s_buildManager;
+
+        [Import]
+        private UnconfiguredProject UnconfiguredProject { get; set; } = null!;
+
+        [Import]
+        private ConfiguredProject ConfiguredProject { get; set; } = null!;
+
+        /// <summary>
+        /// Sets the BuildManager.
+        /// </summary>
+        public static void SetBuildManager(BuildManager buildManager)
+        {
+            s_buildManager = buildManager;
+        }
+
+        /// <summary>
+        /// Constructor.
+        /// </summary>
+        public BuildProvider()
+        {
+            // An instance is created for each of the SDK-style projects.
+        }
+
+        /// <summary>
+        /// Implements IBuildProvider.SupportsMultiThreadedBuild.
+        /// </summary>
+        public bool SupportsMultiThreadedBuild => false;
+
+        /// <summary>
+        /// Implements IBuildProvider.IsBuildActionSupportedAsync.
+        /// </summary>
+        public Task<bool> IsBuildActionSupportedAsync(BuildAction buildAction, bool duringQueryStartBuild, CancellationToken cancellationToken = default)
+        {
+            return Task.FromResult(true);
+        }
+
+        /// <summary>
+        /// Implements IBuildProvider.BuildAsync.
+        /// </summary>
+        public async Task<IBuildResult> BuildAsync(TextWriter outputWriter, BuildAction buildAction, IImmutableDictionary<string, string>? properties = null, CancellationToken cancellationToken = default)
+        {
+            bool succ = false;
+
+            if (s_buildManager != null)
+            {
+                string projectName = UnconfiguredProject.FullPath;
+
+                var projectPropertiesProvider = ConfiguredProject.Services.ProjectPropertiesProvider;
+                if (projectPropertiesProvider != null)
+                {
+                    string buildFilter = await projectPropertiesProvider.GetCommonProperties().GetEvaluatedPropertyValueAsync(Constants.CombinedDominoBuildFilterProp);
+
+                    if (buildFilter == null)
+                    {
+                        s_buildManager.WriteIncompatibleMessage(Path.GetFileName(projectName));
+                    }
+
+                    if (!string.IsNullOrEmpty(projectName) && !string.IsNullOrEmpty(buildFilter))
+                    {
+                        succ = await s_buildManager.BuildProjectAsync(projectName, buildFilter);
+                    }
+                }
+                else
+                {
+                    outputWriter.WriteLine("BuildProvider: projectPropertiesProvider is null.");
+                }
+            }
+            else
+            {
+                outputWriter.WriteLine("BuildProvider: s_buildManager is null.");
+            }
+
+            return new BuildXLBuildResult(succ);
+        }
+
+        private class BuildXLBuildResult : IBuildResult
+        {
+            private readonly bool m_succ;
+
+            public BuildResult MSBuildResult => null!;
+
+            public BuildResultCode OverallResult => (m_succ ? BuildResultCode.Success : BuildResultCode.Failure);
+
+            public int Warnings => 0;
+
+            public int Errors => (m_succ ? 0 : 1);
+
+            public BuildXLBuildResult(bool succ)
+            {
+                m_succ = succ;
+            }
+        }
+    }
+
+    /// <summary>
+    /// Implements IBuildUpToDateCheckProvider.
+    /// We do not use the default IBuildUpToDateCheckProvider provided by the Common Project System (CPS).
+    /// We always return false from IsUpToDateAsync to let BuildXL decide whether to rebuild.
+    /// </summary>
+    [Export(typeof(IBuildUpToDateCheckProvider))]
+    [AppliesTo("BuildXL")]
+    [Order(1000, SuppressLowerPriority = true)]
+    [ExportMetadata("BeforeDrainCriticalTasks", true)]
+    public sealed class BuildUpToDateCheckProvider : IBuildUpToDateCheckProvider
+    {
+        /// <summary>
+        /// Implements IBuildUpToDateCheckProvider.IsUpToDateAsync.
+        /// </summary>
+        public Task<bool> IsUpToDateAsync(BuildAction buildAction, TextWriter logger, CancellationToken cancellationToken = default)
+        {
+            return Task.FromResult(false);
+        }
+
+        /// <summary>
+        /// Implements IBuildUpToDateCheckProvider.IsUpToDateCheckEnabledAsync.
+        /// </summary>
+        public Task<bool> IsUpToDateCheckEnabledAsync(CancellationToken cancellationToken = default)
+        {
+            return Task.FromResult(true);
+        }
+    }
+}
+
+#nullable restore

Public/Src/IDE/VsIntegration/BuildXLVsPackageShared/VsProject/ProjectFlavorFactory.cs

@@ -68,6 +68,7 @@ namespace BuildXL.VsPackage.VsProject
             m_idleTaskScheduler = (TaskScheduler)taskSchedulerService.GetTaskScheduler((uint)VsTaskRunContext.UIThreadBackgroundPriority);
             m_buildManager = new BuildManager(this);
             buildManagerHolder.BuildManager = m_buildManager;
+            BuildProvider.SetBuildManager(m_buildManager);
 
             IVsOutputWindowPane dominoDebugPane;
             outputWindow.GetPane(ref guid, out dominoDebugPane);

cg/nuget/cgmanifest.json

@@ -2283,7 +2283,7 @@
         "Type": "NuGet",
         "NuGet": {
           "Name": "Microsoft.VisualStudio.ProjectSystem",
-          "Version": "17.0.667-pre"
+          "Version": "17.3.74-pre"
         }
       }
     },

config.microsoftInternal.dsc

@@ -91,6 +91,7 @@ export const pkgs = isMicrosoftInternal ? [
 
     // Part of VSSDK used by IDE/VsIntegration
     { id: "Microsoft.Internal.VisualStudio.Interop", version: "17.2.32405.191" },
+    { id: "Microsoft.VisualStudio.ProjectSystem", version: "17.3.74-pre" },
 ] : [
 
     // Artifact packages and dependencies in OSS
@@ -114,5 +115,6 @@ export const resolver = {
         f`Private/InternalSdk/BuildXL.Tracing.AriaTenantToken/module.config.dsc`,
         f`Private/InternalSdk/AnyBuild.SDK/module.config.dsc`,
         f`Private/InternalSdk/Microsoft.Internal.VisualStudio.Interop/module.config.dsc`,
+        f`Private/InternalSdk/Microsoft.VisualStudio.ProjectSystem/module.config.dsc`,
     ]
 };

config.nuget.vssdk.dsc

@@ -10,7 +10,6 @@ export const pkgs = [
     { id: "Microsoft.VisualStudio.Imaging", version: "15.8.28010", dependentPackageIdsToSkip: ["Microsoft.VisualStudio.Utilities"] }, // Have to cut this dependency because it is 46 only and this package is 45 compatible
     { id: "Microsoft.VisualStudio.LanguageServer.Protocol", version: "17.0.4103-g225b54d231" },
     { id: "Microsoft.VisualStudio.ProjectAggregator", version: "17.0.0-previews-3-31605-261" },
-    { id: "Microsoft.VisualStudio.ProjectSystem", version: "17.0.667-pre" },
     { id: "Microsoft.VisualStudio.SDK.EmbedInteropTypes", version: "15.0.26" },
     { id: "Microsoft.VisualStudio.SDK.VsixSuppression", version: "14.1.15" },
     { id: "Microsoft.VisualStudio.Shell.14.0", version: "14.3.25407", dependentPackageIdsToSkip: ["*"] }, // Have cut dependencies due to qualifier mismatches