Microsoft.DotNet.Build.Tasks.TargetFramework.targets

<!-- Licensed to the .NET Foundation under one or more agreements. The .NET Foundation licenses this file to you under the MIT license. -->
<Project>
  <UsingTask TaskName="ChooseBestTargetFrameworksTask" AssemblyFile="$(DotNetBuildTasksTargetFrameworkAssembly)" />

  <!-- We filter _InnerBuildProjects items during DispatchToInnerBuilds and Clean to only run for best target frameworks. -->
  <Target Name="RunOnlyBestTargetFrameworks"
          Condition="'$(BuildTargetFramework)' != ''" 
          BeforeTargets="DispatchToInnerBuilds;Clean"
          DependsOnTargets="GetProjectWithBestTargetFrameworks">
    <ItemGroup>
      <_OriginalInnerBuildProjects Include="@(_InnerBuildProjects)" />
      <_InnerBuildProjects Remove="@(_InnerBuildProjects)" />
      <_InnerBuildProjects Include="@(InnerBuildProjectsWithBestTargetFramework)" />
    </ItemGroup>
  </Target>
  
  <!-- As _InnerBuildProjects items are used in the GetTargetFrameworks path as well (>= .NET 5), we restore the item state. -->
  <Target Name="RestoreInnerBuildProjects"
          BeforeTargets="GetTargetFrameworksWithPlatformFromInnerBuilds"
          AfterTargets="DispatchToInnerBuilds;Clean"
          Condition="'@(_OriginalInnerBuildProjects)' != ''">
    <ItemGroup>
      <_InnerBuildProjects Remove="@(_InnerBuildProjects)" />
      <_InnerBuildProjects Include="@(_OriginalInnerBuildProjects)" />
    </ItemGroup>
  </Target>
  
  <Target Name="GetProjectWithBestTargetFrameworks">
    <ItemGroup Condition="'$(BuildTargetFramework)' != ''">
      <_BuildTargetFrameworkWithTargetOS Include="$(BuildTargetFramework)-$(TargetOS)" />
    </ItemGroup>
    <ItemGroup Condition="'$(BuildTargetFramework)' == ''">
      <_BuildTargetFrameworkWithoutOS Include="$([MSBuild]::Unescape($([System.Text.RegularExpressions.Regex]::Replace('$(TargetFrameworks)', '(-[^;]+)', ''))))" />
      <!-- TODO: Find a better way to filter out non applicable TargetOS values for .NET Framework. -->
      <_BuildTargetFrameworkWithTargetOS Include="@(_BuildTargetFrameworkWithoutOS->Distinct()->'%(Identity)-$(TargetOS)')"
                                         Condition="'$(TargetOS)' == 'windows' or !$([System.String]::Copy('%(Identity)').StartsWith('net4'))" />
    </ItemGroup>
    
    <ChooseBestTargetFrameworksTask BuildTargetFrameworks="@(_BuildTargetFrameworkWithTargetOS);$(AdditionalBuildTargetFrameworks)"
                                    SupportedTargetFrameworks="$(TargetFrameworks)"
                                    RuntimeGraph="$(RuntimeGraph)"
                                    Distinct="true">
      <Output TaskParameter="BestTargetFrameworks" ItemName="_BestTargetFramework" />
    </ChooseBestTargetFrameworksTask>

    <!-- Create inner build project nodes with the TargetFramework supplied via AdditionalProperties. -->
    <ItemGroup>
      <_BestTargetFramework Project="$(MSBuildProjectFile)" />
      <InnerBuildProjectsWithBestTargetFramework Include="%(_BestTargetFramework.Project)"
                                                 AdditionalProperties="TargetFramework=%(Identity)" />
    </ItemGroup>
  </Target>
</Project>