ref.proj

<Project Sdk="Microsoft.Build.Traversal">
  <Import Project="Sdk.props" Sdk="Microsoft.DotNet.SharedFramework.Sdk" />

  <PropertyGroup>
    <TraversalGlobalProperties>BuildAllProjects=true</TraversalGlobalProperties>
    <IsPackable>false</IsPackable>
  </PropertyGroup>

  <ItemGroup>
    <_allRef Include="$(MSBuildThisFileDirectory)*\ref\*.csproj"
             Exclude="@(ProjectExclusions)" />
    <NonNetCoreAppProject Include="@(_allRef)"
                          Exclude="@(NetCoreAppLibrary->'%(Identity)\ref\%(Identity).csproj')" />
    <NetCoreAppProject Include="@(_allRef)"
                       Exclude="@(NonNetCoreAppProject)" />
    <GeneratedShimProject Include="shims\generated\*.csproj"
                          Condition="'$(BuildTargetFramework)' == '$(NetCoreAppCurrent)' or '$(BuildTargetFramework)' == ''" />
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="@(NetCoreAppProject)" />

    <!-- Restore only and build later. -->
    <ProjectReference Include="@(NonNetCoreAppProject);
                               @(GeneratedShimProject)"
                      Condition="'$(MSBuildRestoreSessionId)' != ''" />
  </ItemGroup>

  <Target Name="BuildGeneratedShims"
          AfterTargets="Build"
          Condition="'@(GeneratedShimProject)' != ''">
    <MSBuild Targets="Build"
             Projects="@(GeneratedShimProject)"
             Properties="$(TraversalGlobalProperties)" />
  </Target>

  <Target Name="GetRefPackFiles">
    <ItemGroup>
      <RefPackLibFile Include="$(MicrosoftNetCoreAppRefPackRefDir)*.*">
        <TargetPath>ref/$(NetCoreAppCurrent)</TargetPath>
        <IsSymbolFile Condition="$([System.String]::Copy('%(Identity)').EndsWith('pdb'))">true</IsSymbolFile>
      </RefPackLibFile>
    </ItemGroup>
    <!-- We need to set this metadata in a separate ItemGroup than when the Items are initially populated in order to
    have access to the Extension metadata. -->
    <ItemGroup>
      <RefPackLibFile>
        <IsSymbolFile Condition="'%(Extension)' == '.pdb'">true</IsSymbolFile>
      </RefPackLibFile>
    </ItemGroup>
  </Target>

  <!-- Generate the ref pack's FrameworkList.xml -->
  <UsingTask TaskName="CreateFrameworkListFile" AssemblyFile="$(DotNetSharedFrameworkTaskFile)"/>
  <Target Name="GenerateFrameworkListFile"
          DependsOnTargets="GetRefPackFiles"
          AfterTargets="BuildGeneratedShims"
          Inputs="@(RefPackLibFile)"
          Outputs="$(MicrosoftNetCoreAppRefPackDataDir)FrameworkList.xml"
          Condition="'$(BuildTargetFramework)' == '$(NetCoreAppCurrent)' or '$(BuildTargetFramework)' == ''">
    <ItemGroup>
      <FrameworkListRootAttribute Include="Name" Value="$(NetCoreAppCurrentBrandName)" />
      <FrameworkListRootAttribute Include="TargetFrameworkIdentifier" Value="$(NetCoreAppCurrentIdentifier)" />
      <FrameworkListRootAttribute Include="TargetFrameworkVersion" Value="$(NetCoreAppCurrentVersion)" />
      <FrameworkListRootAttribute Include="FrameworkName" Value="$(MicrosoftNetCoreAppFrameworkName)" />
    </ItemGroup>

    <CreateFrameworkListFile Files="@(RefPackLibFile)"
                             TargetFile="$(MicrosoftNetCoreAppRefPackDataDir)FrameworkList.xml"
                             TargetFilePrefixes="ref/;runtimes/"
                             RootAttributes="@(FrameworkListRootAttribute)" />
  </Target>

  <Target Name="BuildNonNetCoreAppProjects"
          AfterTargets="GenerateFrameworkListFile">
    <MSBuild Targets="Build"
             BuildInParallel="true"
             Projects="@(NonNetCoreAppProject)"
             Properties="$(TraversalGlobalProperties)" />
  </Target>

  <!-- Build generated shims with the full reference closure, including OOB assemblies. -->
  <Target Name="RebuildGeneratedShims"
          AfterTargets="BuildNonNetCoreAppProjects"
          Condition="'@(GeneratedShimProject)' != ''">
    <MSBuild Targets="Build"
             Projects="@(GeneratedShimProject)"
             Properties="$(TraversalGlobalProperties);_Incremental=true" />
  </Target>

  <Import Project="Sdk.targets" Sdk="Microsoft.DotNet.SharedFramework.Sdk" />
</Project>