Remove MSBuild dependencies from BuidlHost deps.json

eng/targets/PackageDownloadAndReference.targets

@@ -0,0 +1,31 @@
+<Project>
+
+  <!--
+  Based on https://github.com/dotnet/runtime/blob/9893d145ebb61ae592afa1a64baa2f6f094b1f6b/eng/PackageDownloadAndReference.targets
+
+  These file supports using PackageDownloadAndReference items.
+  The PackageDownloadAndReference item is used to download a package and reference it in the project, without restoring the package's dependency closure.
+  When using PackageDownloadAndReference you are responsible for selecting the correct assets from the package and ensuring that the package and it's
+  dependencies are available at runtime.
+  The PackageDownloadAndReference item has the following metadata:
+    - Folder: The folder in the package where the assembly is located.
+    - AssemblyName: The name of the assembly to reference.
+    - Private: Whether the reference should be private (copied to the output directory) or not. Default is false.
+  A common use case for PackageDownloadAndReference is to reference assemblies provided by MSBuild or the .NET SDK.
+  -->
+
+  <ItemDefinitionGroup>
+    <PackageDownloadAndReference>
+      <Folder>lib/$(TargetFramework)</Folder>
+      <Private>false</Private>
+    </PackageDownloadAndReference>
+  </ItemDefinitionGroup>
+
+  <ItemGroup>
+    <PackageDownload Include="@(PackageDownloadAndReference)" />
+    <PackageDownload Update="@(PackageDownloadAndReference)" Version="[%(Version)]"/>
+    <PackageDownloadAndReference Update="@(PackageDownloadAndReference)" PackageFolder="$([System.String]::new(%(Identity)).ToLowerInvariant())" AssemblyName="%(Identity)" />
+    <Reference Include="@(PackageDownloadAndReference->'$(NuGetPackageRoot)%(PackageFolder)/%(Version)/%(Folder)/%(AssemblyName).dll')" />
+  </ItemGroup>
+
+</Project>

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

@@ -5,26 +5,43 @@
     <OutputType>Exe</OutputType>
     <RootNamespace>Microsoft.CodeAnalysis</RootNamespace>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(SourceBuildTargetFrameworks);net472</TargetFrameworks>
+    <TargetFrameworks>$(SourceBuildToolsetTargetFramework);net472</TargetFrameworks>
     <!-- We'll always be running our build host with the same host that is used to launch the language server process directly, so we don't need to create another one -->
     <UseAppHost>false</UseAppHost>
     <!-- Set to false since it's also set in Microsoft.CodeAnalysis.LanguageServer -->
     <SelfContained>false</SelfContained>
+
+    <!--
+      We specifically reference Microsoft.Build 17.3.4, since it's the oldest version still compatible $(NetRoslynBuildHostNetCoreVersion).
+      The version targeted is only used for build time, since we use MSBuildLocator to discover the proper version at runtime.
+    -->
+    <_MsbuildVersion>17.3.4</_MsbuildVersion>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="..\..\..\Compilers\Shared\GlobalAssemblyCacheHelpers\GlobalAssemblyCacheLocation.cs">
       <Link>InternalUtilities\GlobalAssemblyCache.cs</Link>
     </Compile>
   </ItemGroup>
+  <ItemGroup Condition="'$(DotNetBuildSourceOnly)' == 'true'">
+    <PackageReference Include="Microsoft.Build" VersionOverride="$(_MsbuildVersion)" ExcludeAssets="Runtime" PrivateAssets="All" />
+    <PackageReference Include="Microsoft.Build.Framework" VersionOverride="$(_MsbuildVersion)" ExcludeAssets="Runtime" />
+    <PackageReference Include="Microsoft.Build.Tasks.Core" VersionOverride="$(_MsbuildVersion)" ExcludeAssets="Runtime" PrivateAssets="All" />
+    <PackageReference Include="Microsoft.Build.Utilities.Core" VersionOverride="$(_MsbuildVersion)" ExcludeAssets="Runtime" PrivateAssets="All" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(DotNetBuildSourceOnly)' != 'true'">
+    <!-- Reference MSBuild directly to avoid redistributing its package closure and including the dependencies in deps.json file. -->
+    <PackageDownloadAndReference Include="Microsoft.Build" Version="$(_MsbuildVersion)" Folder="ref/$(TargetFramework)" />
+    <PackageDownloadAndReference Include="Microsoft.Build.Framework" Version="$(_MsbuildVersion)" Folder="ref/$(TargetFramework)" />
+    <PackageDownloadAndReference Include="Microsoft.Build.Tasks.Core" Version="$(_MsbuildVersion)" Folder="ref/$(TargetFramework)" />
+    <PackageDownloadAndReference Include="Microsoft.Build.Utilities.Core" Version="$(_MsbuildVersion)" Folder="ref/$(TargetFramework)" />
+  </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.Build" Version="$(RefOnlyMicrosoftBuildVersion)" ExcludeAssets="Runtime" PrivateAssets="All" />
-    <PackageReference Include="Microsoft.Build.Framework" Version="$(RefOnlyMicrosoftBuildFrameworkVersion)" ExcludeAssets="Runtime" />
-    <PackageReference Include="Microsoft.Build.Tasks.Core" Version="$(RefOnlyMicrosoftBuildTasksCoreVersion)" ExcludeAssets="Runtime" PrivateAssets="All" />
     <PackageReference Include="Microsoft.Build.Locator" Version="$(MicrosoftBuildLocatorVersion)" PrivateAssets="All" />
-    <PackageReference Include="System.Text.Json" Version="$(SystemTextJsonFixedVersion)" PrivateAssets="All" Condition="'$(DotnetBuildFromSource)' != 'true'"/>
+    <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="$(MicrosoftExtensionsLoggingConsoleVersion)" />
     <PackageReference Include="StreamJsonRpc" Version="$(StreamJsonRpcVersion)" Condition="'$(DotNetBuildFromSource)' != 'true'" />
     <PackageReference Include="System.CommandLine" Version="$(SystemCommandLineVersion)" />
-    <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="$(MicrosoftExtensionsLoggingConsoleVersion)" />
+    <PackageReference Include="System.Text.Json" Version="$(SystemTextJsonFixedVersion)" PrivateAssets="All" Condition="'$(DotnetBuildFromSource)' != 'true'"/>
+    <PackageReference Include="System.Threading.Tasks.Dataflow" Version="$(SystemThreadingTasksDataflowVersion)" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\..\Compilers\Core\Portable\Microsoft.CodeAnalysis.csproj" />
@@ -45,4 +62,5 @@
     <InternalsVisibleTo Include="Microsoft.CodeAnalysis.EditorFeatures2.UnitTests" />
     <InternalsVisibleTo Include="DynamicProxyGenAssembly2" Key="$(MoqPublicKey)" LoadsWithinVisualStudio="false" />
   </ItemGroup>
-</Project>
+  <Import Project="$(RepositoryEngineeringDir)targets\PackageDownloadAndReference.targets"/>
+</Project>