From ab84a8cfaf41327705e35d63e77ba8e34ffdc4c1 Mon Sep 17 00:00:00 2001
From: Jeff Handley <jeffhandley@users.noreply.github.com>
Date: Tue, 27 Apr 2021 01:20:54 -0700
Subject: [PATCH] Simplify condition checking for downlevel from net5.0
 (#51888)

* Simplify condition checking for downlevel from net5.0

* Use IsTargetFrameworkCompatible to check the version
---
 src/libraries/Directory.Build.targets | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/libraries/Directory.Build.targets b/src/libraries/Directory.Build.targets
index 4c660f5d459ff..8fadefdc75ac5 100644
--- a/src/libraries/Directory.Build.targets
+++ b/src/libraries/Directory.Build.targets
@@ -238,13 +238,13 @@
     <IncludePlatformAttributes Condition="'$(IncludePlatformAttributes)' == '' and ('$(SupportedOSPlatforms)' != '' or '$(UnsupportedOSPlatforms)' != '')">true</IncludePlatformAttributes>
   </PropertyGroup>
 
-  <ItemGroup Condition="'$(IncludePlatformAttributes)' == 'true' and ('$(TargetFrameworkIdentifier)' != '.NETCoreApp' or $([MSBuild]::VersionLessThan($(TargetFrameworkVersion), '5.0')))">
+  <ItemGroup Condition="'$(IncludePlatformAttributes)' == 'true' and !$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net5.0'))">
     <Compile Include="$(CoreLibSharedDir)System\Runtime\Versioning\PlatformAttributes.cs" Link="System\Runtime\Versioning\PlatformAttributes.cs" />
   </ItemGroup>
 
   <!-- Adds ObsoleteAttribute to projects that need to apply downlevel Obsoletions with DiagnosticId and UrlFormat -->
   <Choose>
-    <When Condition="'$(IncludeInternalObsoleteAttribute)' == 'true' and ($(TargetFramework.StartsWith('netstandard')) or $(TargetFramework.StartsWith('netcoreapp')) or '$(TargetFrameworkIdentifier)' == '.NETFramework')">
+    <When Condition="'$(IncludeInternalObsoleteAttribute)' == 'true' and !$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net5.0'))">
       <ItemGroup>
         <Compile Include="$(CoreLibSharedDir)System\ObsoleteAttribute.cs" Link="System\ObsoleteAttribute.cs" />
       </ItemGroup>