Use TaskHostFactory to resolve file lock issues and simplify tasks build (#122525)

Fixes dotnet/dotnet#3875

---------

Co-authored-by: Copilot <[email protected]>

Author: ViktorHofer

Build.proj

@@ -1,21 +1,14 @@
 <Project Sdk="Microsoft.Build.Traversal">
 
   <ItemGroup>
-    <!-- Subsets are already imported by Directory.Build.props. -->
+    <ProjectReference Include="$(RepoTasksDir)tasks.proj" BuildInParallel="false" />
+    <!-- Subsets.props which defines @(ProjectToBuild) is already imported in Directory.Build.props. -->
     <ProjectReference Include="@(ProjectToBuild)" />
-    <!-- Only include tasks.proj during restore and build incrementally via a target. -->
-    <ProjectReference Include="$(RepoTasksDir)tasks.proj" Condition="'$(MSBuildRestoreSessionId)' != ''" />
   </ItemGroup>
 
   <Import Project="$(RepositoryEngineeringDir)SubsetValidation.targets" />
   <Import Project="$(RepositoryEngineeringDir)restore\optimizationData.targets" Condition="'$(DotNetBuildSourceOnly)' != 'true'" />
 
-  <Target Name="BuildLocalTasks"
-          BeforeTargets="Build">
-    <MSBuild Projects="$(RepoTasksDir)tasks.proj"
-             Targets="BuildIncrementally" />
-  </Target>
-
   <Target Name="SetupBootstrapLayout"
           AfterTargets="Build"
           Condition="'$(Subset)' == 'bootstrap'">
@@ -51,4 +44,5 @@
       SkipUnchangedFiles="true" />
     <Message Importance="high" Text="Bootstrap files copied to $(ArtifactsDir)bootstrap" />
   </Target>
+
 </Project>

Directory.Build.props

@@ -133,8 +133,7 @@
     <MonoAOTCompilerDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'MonoAOTCompiler', '$(TasksConfiguration)', '$(NetCoreAppToolCurrent)'))</MonoAOTCompilerDir>
     <MonoTargetsTasksDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'MonoTargetsTasks', '$(TasksConfiguration)', '$(NetCoreAppToolCurrent)'))</MonoTargetsTasksDir>
     <TestExclusionListTasksDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'TestExclusionListTasks', '$(TasksConfiguration)', '$(NetCoreAppToolCurrent)'))</TestExclusionListTasksDir>
-    <InstallerTasksAssemblyPath Condition="'$(MSBuildRuntimeType)' == 'Core'">$([MSBuild]::NormalizePath('$(ArtifactsBinDir)', 'installer.tasks', '$(TasksConfiguration)', '$(NetCoreAppToolCurrent)', 'installer.tasks.dll'))</InstallerTasksAssemblyPath>
-    <InstallerTasksAssemblyPath Condition="'$(MSBuildRuntimeType)' != 'Core'">$([MSBuild]::NormalizePath('$(ArtifactsBinDir)', 'installer.tasks', '$(TasksConfiguration)', '$(NetFrameworkToolCurrent)', 'installer.tasks.dll'))</InstallerTasksAssemblyPath>
+    <InstallerTasksAssemblyPath>$([MSBuild]::NormalizePath('$(ArtifactsBinDir)', 'installer.tasks', '$(TasksConfiguration)', '$(NetCoreAppToolCurrent)', 'installer.tasks.dll'))</InstallerTasksAssemblyPath>
     <Crossgen2SdkOverridePropsPath Condition="'$(MSBuildRuntimeType)' == 'Core'">$([MSBuild]::NormalizePath('$(ArtifactsBinDir)', 'Crossgen2Tasks', '$(TasksConfiguration)', '$(NetCoreAppToolCurrent)', 'Microsoft.NET.CrossGen.props'))</Crossgen2SdkOverridePropsPath>
     <Crossgen2SdkOverrideTargetsPath Condition="'$(MSBuildRuntimeType)' == 'Core'">$([MSBuild]::NormalizePath('$(ArtifactsBinDir)', 'Crossgen2Tasks', '$(TasksConfiguration)', '$(NetCoreAppToolCurrent)', 'Microsoft.NET.CrossGen.targets'))</Crossgen2SdkOverrideTargetsPath>
     <AppleAppBuilderTasksAssemblyPath>$([MSBuild]::NormalizePath('$(AppleAppBuilderDir)', 'AppleAppBuilder.dll'))</AppleAppBuilderTasksAssemblyPath>

Directory.Build.targets

@@ -31,6 +31,13 @@
   <Import Project="$(RepositoryEngineeringDir)packaging.targets" Condition="'$(IsPackable)' == 'true' and '$(MSBuildProjectExtension)' != '.pkgproj'" />
   <Import Project="$(RepositoryEngineeringDir)slngen.targets" Condition="'$(IsSlnGen)' == 'true'" />
 
+  <PropertyGroup>
+    <NetCoreAppCurrentBuildSettings>$(NetCoreAppCurrent)-$(TargetOS)-$(Configuration)-$(TargetArchitecture)</NetCoreAppCurrentBuildSettings>
+    <NativeBinDir>$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'native', '$(NetCoreAppCurrentBuildSettings)'))</NativeBinDir>
+    <NetCoreAppCurrentTestHostPath Condition="'$(UseDefaultTestHost)' != 'true'">$([MSBuild]::NormalizeDirectory('$(ArtifactsBinDir)', 'testhost', '$(NetCoreAppCurrentBuildSettings)'))</NetCoreAppCurrentTestHostPath>
+    <NetCoreAppCurrentTestHostSharedFrameworkPath Condition="'$(UseDefaultTestHost)' != 'true'">$([MSBuild]::NormalizeDirectory('$(NetCoreAppCurrentTestHostPath)', 'shared', '$(MicrosoftNetCoreAppFrameworkName)', '$(ProductVersion)'))</NetCoreAppCurrentTestHostSharedFrameworkPath>
+  </PropertyGroup>
+
   <!--
   When .NET gets built from source, make the SDK aware there are bootstrap packages
   for Microsoft.NETCore.App.Runtime.<rid> and Microsoft.NETCore.App.Crossgen2.<rid>.