Implement IManagedHotReloadAgent2 and IManagedHotReloadAgent4 for ProjectHotReloadSession

Directory.Packages.props

@@ -5,6 +5,7 @@
 
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
+    <VSDebuggerVersion>17.12.3-dev</VSDebuggerVersion>
   </PropertyGroup>
 
   <!--
@@ -48,8 +49,8 @@
     <PackageVersion Include="Microsoft.VisualStudio.Data.Services"                                   Version="17.0.0-preview-2-31223-026" />
     <PackageVersion Include="Microsoft.VisualStudio.DataDesign.Common"                               Version="17.0.0-preview-2-31223-026" />
     <PackageVersion Include="Microsoft.VisualStudio.DataTools.Interop"                               Version="17.0.0-preview-2-31223-026" />
-    <PackageVersion Include="Microsoft.VisualStudio.Debugger.Contracts"                              Version="17.4.0-beta.22470.1" />
-    <PackageVersion Include="Microsoft.VisualStudio.Debugger.UI.Interfaces"                          Version="17.4.0-beta.22470.1" />
+    <PackageVersion Include="Microsoft.VisualStudio.Debugger.Contracts"                              Version="$(VSDebuggerVersion)" />
+    <PackageVersion Include="Microsoft.VisualStudio.Debugger.UI.Interfaces"                          Version="$(VSDebuggerVersion)" />
     <PackageVersion Include="Microsoft.VisualStudio.Designer.Interfaces"                             Version="17.11.38822-preview.1" />
     <PackageVersion Include="Microsoft.VisualStudio.ImageCatalog"                                    Version="17.11.38822-preview.1" />
     <PackageVersion Include="Microsoft.VisualStudio.Interop"                                         Version="17.11.38822-preview.1" />

nuget.config

@@ -3,6 +3,7 @@
 <configuration>
   <packageSources>
     <clear />
+    <add key="local" value="C:\Users\xiaoyuz\source\repos\VSDebugCore\artifacts\packages\Debug\Shipping\" />
     <add key="dotnet-project-system-public-packages" value="https://pkgs.dev.azure.com/azure-public/vside/_packaging/dotnet-project-system-public-packages/nuget/v3/index.json" />
   </packageSources>
 </configuration>

setup/ProjectSystemSetup/ProjectSystemSetup.csproj

@@ -15,6 +15,7 @@
     <!-- Note: No idea why ProjectSystem is the AssemblyName instead of using the MSBuildProjectName of ProjectSystemSetup. -->
     <AssemblyName>ProjectSystem</AssemblyName>
     <TargetFramework>net472</TargetFramework>
+    <VSSDKTargetPlatformRegRootSuffix>RoslynDev</VSSDKTargetPlatformRegRootSuffix>
 
     <!-- VSIX -->
     <ExtensionInstallationRoot>Extensions</ExtensionInstallationRoot>

src/Microsoft.VisualStudio.ProjectSystem.Managed.VS/ProjectSystem/VS/HotReload/ProjectHotReloadSession.cs

@@ -1,11 +1,13 @@
 // Licensed to the .NET Foundation under one or more agreements. The .NET Foundation licenses this file to you under the MIT license. See the LICENSE.md file in the project root for more information.
 
+using Microsoft.VisualStudio.Debugger.Contracts.EditAndContinue;
 using Microsoft.VisualStudio.Debugger.Contracts.HotReload;
 using Microsoft.VisualStudio.HotReload.Components.DeltaApplier;
+using static Microsoft.VisualStudio.ProjectSystem.VS.HotReload.ProjectHotReloadSessionManager;
 
 namespace Microsoft.VisualStudio.ProjectSystem.VS.HotReload
 {
-    internal class ProjectHotReloadSession : IManagedHotReloadAgent, IProjectHotReloadSession, IProjectHotReloadSessionInternal
+    internal class ProjectHotReloadSession : IManagedHotReloadAgent, IManagedHotReloadAgent2, IManagedHotReloadAgent4, IProjectHotReloadSession, IProjectHotReloadSessionInternal
     {
         private readonly string _variant;
         private readonly string _runtimeVersion;
@@ -288,5 +290,25 @@ private void EnsureDeltaApplierforSession()
                     ?? _deltaApplierCreator.Value.CreateManagedDeltaApplier(_runtimeVersion);
             }
         }
+
+        public ValueTask<int?> GetTargetLocalProcessIdAsync(CancellationToken cancellationToken)
+        {
+            if (_callback is HotReloadState hotReloadState)
+            {
+                return new ValueTask<int?>(hotReloadState.Process?.Id);
+            }
+
+            return new ValueTask<int?>();
+        }
+
+        public ValueTask<string?> GetProjectFullPathAsync(CancellationToken cancellationToken)
+        {
+            if (_callback is HotReloadState hrs)
+            {
+                return new ValueTask<string?>(hrs.Project?.FullPath);
+            }
+
+            return new ValueTask<string?>();
+        }
     }
 }

src/Microsoft.VisualStudio.ProjectSystem.Managed.VS/ProjectSystem/VS/HotReload/ProjectHotReloadSessionManager.cs

@@ -449,7 +449,7 @@ async Task ApplyHotReloadUpdateInternalAsync()
             }
         }
 
-        private class HotReloadState : IProjectHotReloadSessionCallback
+        internal class HotReloadState : IProjectHotReloadSessionCallback
         {
             private readonly ProjectHotReloadSessionManager _sessionManager;
 
@@ -459,9 +459,12 @@ private class HotReloadState : IProjectHotReloadSessionCallback
             // TODO: Support restarting the session.
             public bool SupportsRestart => false;
 
+            public UnconfiguredProject? Project { get; }
+
             public HotReloadState(ProjectHotReloadSessionManager sessionManager)
             {
                 _sessionManager = sessionManager;
+                Project = _sessionManager._project;
             }
 
             internal void OnProcessExited(object sender, EventArgs e)