From c280248c338da6465c1bc69abd8dfff7a8bc3c88 Mon Sep 17 00:00:00 2001
From: Jeff Handley <jeff.handley@microsoft.com>
Date: Sat, 22 Aug 2020 01:02:04 -0700
Subject: [PATCH 1/6] Use SupportedOSPlatforms property to generate assembly
 attributes; do not allow supported and unsupported combinations

---
 eng/targetframeworksuffix.props                | 12 ++++++++++++
 eng/versioning.targets                         | 18 ++++++++----------
 src/libraries/Directory.Build.targets          |  2 +-
 ...icrosoft.Extensions.Logging.EventLog.csproj |  1 +
 .../Directory.Build.props                      |  2 +-
 .../Directory.Build.props                      |  2 +-
 .../Directory.Build.props                      |  2 +-
 .../System.Data.OleDb/Directory.Build.props    |  2 +-
 .../Directory.Build.props                      |  2 +-
 .../Directory.Build.props                      |  2 +-
 .../Directory.Build.props                      |  2 +-
 .../Directory.Build.props                      |  2 +-
 .../Directory.Build.props                      |  2 +-
 .../Directory.Build.props                      |  2 +-
 .../System.Management/Directory.Build.props    |  2 +-
 .../Directory.Build.props                      |  2 +-
 .../System.Net.Sockets/Directory.Build.props   |  4 ++--
 .../Directory.Build.props                      |  2 +-
 .../Directory.Build.props                      |  2 +-
 .../Directory.Build.props                      |  4 ++--
 .../Directory.Build.props                      |  2 +-
 .../Directory.Build.props                      |  2 +-
 .../Directory.Build.props                      |  2 +-
 .../Directory.Build.props                      |  2 +-
 .../Directory.Build.props                      |  2 +-
 25 files changed, 45 insertions(+), 34 deletions(-)

diff --git a/eng/targetframeworksuffix.props b/eng/targetframeworksuffix.props
index 96cd8db859c378..4842a3f9401d91 100644
--- a/eng/targetframeworksuffix.props
+++ b/eng/targetframeworksuffix.props
@@ -4,12 +4,14 @@
       <PropertyGroup>
         <TargetsWindows>true</TargetsWindows>
         <PackageTargetRuntime>win</PackageTargetRuntime>
+        <SupportedOSPlatforms>windows</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'Unix'">
       <PropertyGroup>
         <TargetsUnix>true</TargetsUnix>
         <PackageTargetRuntime>unix</PackageTargetRuntime>
+        <SupportedOSPlatforms>unix</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'Linux'">
@@ -17,6 +19,7 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsLinux>true</TargetsLinux>
         <PackageTargetRuntime>linux</PackageTargetRuntime>
+        <SupportedOSPlatforms>unix;linux</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'Android'">
@@ -25,6 +28,7 @@
         <TargetsLinux>true</TargetsLinux>
         <TargetsAndroid>true</TargetsAndroid>
         <PackageTargetRuntime>android</PackageTargetRuntime>
+        <SupportedOSPlatforms>unix;linux;android</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'OSX'">
@@ -32,6 +36,7 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsOSX>true</TargetsOSX>
         <PackageTargetRuntime>osx</PackageTargetRuntime>
+        <SupportedOSPlatforms>unix;macos</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'tvOS'">
@@ -39,6 +44,7 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetstvOS>true</TargetstvOS>
         <PackageTargetRuntime>tvos</PackageTargetRuntime>
+        <SupportedOSPlatforms>unix;tvos</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'iOS'">
@@ -46,6 +52,7 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsiOS>true</TargetsiOS>
         <PackageTargetRuntime>ios</PackageTargetRuntime>
+        <SupportedOSPlatforms>unix;ios</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'FreeBSD'">
@@ -53,6 +60,7 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsFreeBSD>true</TargetsFreeBSD>
         <PackageTargetRuntime>freebsd</PackageTargetRuntime>
+        <SupportedOSPlatforms>unix;freebsd</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'NetBSD'">
@@ -60,6 +68,7 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsNetBSD>true</TargetsNetBSD>
         <PackageTargetRuntime>netbsd</PackageTargetRuntime>
+        <SupportedOSPlatforms>unix</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'illumos'">
@@ -67,6 +76,7 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsIllumos>true</TargetsIllumos>
         <PackageTargetRuntime>illumos</PackageTargetRuntime>
+        <SupportedOSPlatforms>unix</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'Solaris'">
@@ -74,12 +84,14 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsSolaris>true</TargetsSolaris>
         <PackageTargetRuntime>solaris</PackageTargetRuntime>
+        <SupportedOSPlatforms>unix</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'Browser'">
       <PropertyGroup>
         <TargetsBrowser>true</TargetsBrowser>
         <PackageTargetRuntime>browser</PackageTargetRuntime>
+        <SupportedOSPlatforms>browser</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == ''">
diff --git a/eng/versioning.targets b/eng/versioning.targets
index efb7af48b76cb5..a55f19c34a0356 100644
--- a/eng/versioning.targets
+++ b/eng/versioning.targets
@@ -22,20 +22,18 @@
     </AssemblyMetadata>
   </ItemGroup>
 
-  <!-- Adds SupportedOSPlatform attribute for Windows Specific libraries -->
-  <ItemGroup Condition="'$(IsWindowsSpecific)' == 'true' and '$(IsTestProject)' != 'true'">
-    <AssemblyAttribute Include="System.Runtime.Versioning.SupportedOSPlatform">
-        <_Parameter1>windows</_Parameter1>
-    </AssemblyAttribute>
-  </ItemGroup>
-
-  <ItemGroup>
+  <!-- Adds SupportedOSPlatform or UnsupportedOSPlatform attributes -->
+  <ItemGroup Condition="'$(IsTestProject)' != 'true'">
+    <_supportedOSPlatforms Include="$(SupportedOSPlatforms)" />
     <_unsupportedOSPlatforms Include="$(UnsupportedOSPlatforms)" />
   </ItemGroup>
 
-  <Target Name="AddUnsupportedOSPlatformAttribute" BeforeTargets="GenerateAssemblyInfo" AfterTargets="PrepareForBuild">
+  <Target Name="AddAssemblyOSPlatformAttributes" BeforeTargets="GenerateAssemblyInfo" AfterTargets="PrepareForBuild">
     <ItemGroup>
-      <AssemblyAttribute Include="System.Runtime.Versioning.UnsupportedOSPlatform" Condition="'@(_unsupportedOSPlatforms)' != ''">
+      <AssemblyAttribute Include="System.Runtime.Versioning.SupportedOSPlatform" Condition="'@(_supportedOSPlatforms)' != ''">
+        <_Parameter1>%(_supportedOSPlatforms.Identity)</_Parameter1>
+      </AssemblyAttribute>
+      <AssemblyAttribute Include="System.Runtime.Versioning.UnsupportedOSPlatform" Condition="'@(_supportedOSPlatforms)' == '' and '@(_unsupportedOSPlatforms)' != ''">
         <_Parameter1>%(_unsupportedOSPlatforms.Identity)</_Parameter1>
       </AssemblyAttribute>
     </ItemGroup>
diff --git a/src/libraries/Directory.Build.targets b/src/libraries/Directory.Build.targets
index 81ddf6ad6293be..aa5552fdca300d 100644
--- a/src/libraries/Directory.Build.targets
+++ b/src/libraries/Directory.Build.targets
@@ -243,7 +243,7 @@
 
   <!-- Adds System.Runtime.Versioning*Platform* annotation attributes to < .NET 5 builds -->
   <Choose>
-    <When Condition="('$(IncludePlatformAttributes)' == 'true' or '$(IsWindowsSpecific)' == 'true') and ('$(TargetFrameworkIdentifier)' != '.NETCoreApp' or $([MSBuild]::VersionLessThan($(TargetFrameworkVersion), '5.0')))">
+    <When Condition="('$(IncludePlatformAttributes)' == 'true' or '$(SupportedOSPlatforms)' != '' or '$(UnsupportedOSPlatforms)' != '') and ('$(TargetFrameworkIdentifier)' != '.NETCoreApp' or $([MSBuild]::VersionLessThan($(TargetFrameworkVersion), '5.0')))">
       <ItemGroup>
         <Compile Include="$(CoreLibSharedDir)System\Runtime\Versioning\PlatformAttributes.cs" Link="System\Runtime\Versioning\PlatformAttributes.cs" />
       </ItemGroup>
diff --git a/src/libraries/Microsoft.Extensions.Logging.EventLog/src/Microsoft.Extensions.Logging.EventLog.csproj b/src/libraries/Microsoft.Extensions.Logging.EventLog/src/Microsoft.Extensions.Logging.EventLog.csproj
index 9ae5802d972d1a..66afaf579451d4 100644
--- a/src/libraries/Microsoft.Extensions.Logging.EventLog/src/Microsoft.Extensions.Logging.EventLog.csproj
+++ b/src/libraries/Microsoft.Extensions.Logging.EventLog/src/Microsoft.Extensions.Logging.EventLog.csproj
@@ -3,6 +3,7 @@
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;net461</TargetFrameworks>
     <EnableDefaultItems>true</EnableDefaultItems>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/libraries/Microsoft.Win32.Registry.AccessControl/Directory.Build.props b/src/libraries/Microsoft.Win32.Registry.AccessControl/Directory.Build.props
index 33e65b7cb46516..709a22a7537088 100644
--- a/src/libraries/Microsoft.Win32.Registry.AccessControl/Directory.Build.props
+++ b/src/libraries/Microsoft.Win32.Registry.AccessControl/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/Microsoft.Win32.Registry/Directory.Build.props b/src/libraries/Microsoft.Win32.Registry/Directory.Build.props
index 33e65b7cb46516..709a22a7537088 100644
--- a/src/libraries/Microsoft.Win32.Registry/Directory.Build.props
+++ b/src/libraries/Microsoft.Win32.Registry/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/Microsoft.Win32.SystemEvents/Directory.Build.props b/src/libraries/Microsoft.Win32.SystemEvents/Directory.Build.props
index 2f8a8940e012a3..e7e8cb9ac081be 100644
--- a/src/libraries/Microsoft.Win32.SystemEvents/Directory.Build.props
+++ b/src/libraries/Microsoft.Win32.SystemEvents/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Data.OleDb/Directory.Build.props b/src/libraries/System.Data.OleDb/Directory.Build.props
index cef5ef637b168b..6c6a6c1b425414 100644
--- a/src/libraries/System.Data.OleDb/Directory.Build.props
+++ b/src/libraries/System.Data.OleDb/Directory.Build.props
@@ -1,6 +1,6 @@
 <Project>
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Diagnostics.EventLog/Directory.Build.props b/src/libraries/System.Diagnostics.EventLog/Directory.Build.props
index 2f8a8940e012a3..e7e8cb9ac081be 100644
--- a/src/libraries/System.Diagnostics.EventLog/Directory.Build.props
+++ b/src/libraries/System.Diagnostics.EventLog/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Diagnostics.PerformanceCounter/Directory.Build.props b/src/libraries/System.Diagnostics.PerformanceCounter/Directory.Build.props
index 2f8a8940e012a3..e7e8cb9ac081be 100644
--- a/src/libraries/System.Diagnostics.PerformanceCounter/Directory.Build.props
+++ b/src/libraries/System.Diagnostics.PerformanceCounter/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.DirectoryServices.AccountManagement/Directory.Build.props b/src/libraries/System.DirectoryServices.AccountManagement/Directory.Build.props
index e6b3574d56878a..4cf151da3064fc 100644
--- a/src/libraries/System.DirectoryServices.AccountManagement/Directory.Build.props
+++ b/src/libraries/System.DirectoryServices.AccountManagement/Directory.Build.props
@@ -6,6 +6,6 @@
          to a different assembly. -->
     <AssemblyVersion>4.0.0.0</AssemblyVersion>
     <StrongNameKeyId>ECMA</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.DirectoryServices/Directory.Build.props b/src/libraries/System.DirectoryServices/Directory.Build.props
index d5f3585d0abb0b..bfa544ca6f649e 100644
--- a/src/libraries/System.DirectoryServices/Directory.Build.props
+++ b/src/libraries/System.DirectoryServices/Directory.Build.props
@@ -6,6 +6,6 @@
          to a different assembly. -->
     <AssemblyVersion>4.0.0.0</AssemblyVersion>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.IO.FileSystem.AccessControl/Directory.Build.props b/src/libraries/System.IO.FileSystem.AccessControl/Directory.Build.props
index 33e65b7cb46516..709a22a7537088 100644
--- a/src/libraries/System.IO.FileSystem.AccessControl/Directory.Build.props
+++ b/src/libraries/System.IO.FileSystem.AccessControl/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.IO.Pipes.AccessControl/Directory.Build.props b/src/libraries/System.IO.Pipes.AccessControl/Directory.Build.props
index 33e65b7cb46516..709a22a7537088 100644
--- a/src/libraries/System.IO.Pipes.AccessControl/Directory.Build.props
+++ b/src/libraries/System.IO.Pipes.AccessControl/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Management/Directory.Build.props b/src/libraries/System.Management/Directory.Build.props
index d5f3585d0abb0b..bfa544ca6f649e 100644
--- a/src/libraries/System.Management/Directory.Build.props
+++ b/src/libraries/System.Management/Directory.Build.props
@@ -6,6 +6,6 @@
          to a different assembly. -->
     <AssemblyVersion>4.0.0.0</AssemblyVersion>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Net.Http.WinHttpHandler/Directory.Build.props b/src/libraries/System.Net.Http.WinHttpHandler/Directory.Build.props
index 33e65b7cb46516..709a22a7537088 100644
--- a/src/libraries/System.Net.Http.WinHttpHandler/Directory.Build.props
+++ b/src/libraries/System.Net.Http.WinHttpHandler/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Net.Sockets/Directory.Build.props b/src/libraries/System.Net.Sockets/Directory.Build.props
index ce244cbea56199..51f6852d7ef7b3 100644
--- a/src/libraries/System.Net.Sockets/Directory.Build.props
+++ b/src/libraries/System.Net.Sockets/Directory.Build.props
@@ -3,6 +3,6 @@
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
     <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <UnsupportedOSPlatforms Condition="'$(TargetsWindows)' != 'true'">browser</UnsupportedOSPlatforms>
   </PropertyGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/libraries/System.Security.AccessControl/Directory.Build.props b/src/libraries/System.Security.AccessControl/Directory.Build.props
index 33e65b7cb46516..709a22a7537088 100644
--- a/src/libraries/System.Security.AccessControl/Directory.Build.props
+++ b/src/libraries/System.Security.AccessControl/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Security.Cryptography.Cng/Directory.Build.props b/src/libraries/System.Security.Cryptography.Cng/Directory.Build.props
index 33e65b7cb46516..709a22a7537088 100644
--- a/src/libraries/System.Security.Cryptography.Cng/Directory.Build.props
+++ b/src/libraries/System.Security.Cryptography.Cng/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Security.Cryptography.ProtectedData/Directory.Build.props b/src/libraries/System.Security.Cryptography.ProtectedData/Directory.Build.props
index 33e65b7cb46516..37ee66d7748582 100644
--- a/src/libraries/System.Security.Cryptography.ProtectedData/Directory.Build.props
+++ b/src/libraries/System.Security.Cryptography.ProtectedData/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/libraries/System.Security.Principal.Windows/Directory.Build.props b/src/libraries/System.Security.Principal.Windows/Directory.Build.props
index 33e65b7cb46516..709a22a7537088 100644
--- a/src/libraries/System.Security.Principal.Windows/Directory.Build.props
+++ b/src/libraries/System.Security.Principal.Windows/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.ServiceProcess.ServiceController/Directory.Build.props b/src/libraries/System.ServiceProcess.ServiceController/Directory.Build.props
index 33e65b7cb46516..709a22a7537088 100644
--- a/src/libraries/System.ServiceProcess.ServiceController/Directory.Build.props
+++ b/src/libraries/System.ServiceProcess.ServiceController/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Threading.AccessControl/Directory.Build.props b/src/libraries/System.Threading.AccessControl/Directory.Build.props
index 33e65b7cb46516..709a22a7537088 100644
--- a/src/libraries/System.Threading.AccessControl/Directory.Build.props
+++ b/src/libraries/System.Threading.AccessControl/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Threading.Overlapped/Directory.Build.props b/src/libraries/System.Threading.Overlapped/Directory.Build.props
index 33e65b7cb46516..709a22a7537088 100644
--- a/src/libraries/System.Threading.Overlapped/Directory.Build.props
+++ b/src/libraries/System.Threading.Overlapped/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Windows.Extensions/Directory.Build.props b/src/libraries/System.Windows.Extensions/Directory.Build.props
index 2f8a8940e012a3..e7e8cb9ac081be 100644
--- a/src/libraries/System.Windows.Extensions/Directory.Build.props
+++ b/src/libraries/System.Windows.Extensions/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <IsWindowsSpecific>true</IsWindowsSpecific>
+    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 </Project>
\ No newline at end of file

From a1bb7bf9e43558a1a85c676b23a5e8b358531f14 Mon Sep 17 00:00:00 2001
From: Jeff Handley <jeff.handley@microsoft.com>
Date: Sun, 23 Aug 2020 22:20:13 -0700
Subject: [PATCH 2/6] Undo SupportedOSPlatforms properties, but leave
 infrastructure in place

---
 eng/targetframeworksuffix.props                       | 11 -----------
 .../System.Net.Sockets/Directory.Build.props          |  2 +-
 2 files changed, 1 insertion(+), 12 deletions(-)

diff --git a/eng/targetframeworksuffix.props b/eng/targetframeworksuffix.props
index 4842a3f9401d91..af6dc3f2960ce3 100644
--- a/eng/targetframeworksuffix.props
+++ b/eng/targetframeworksuffix.props
@@ -4,14 +4,12 @@
       <PropertyGroup>
         <TargetsWindows>true</TargetsWindows>
         <PackageTargetRuntime>win</PackageTargetRuntime>
-        <SupportedOSPlatforms>windows</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'Unix'">
       <PropertyGroup>
         <TargetsUnix>true</TargetsUnix>
         <PackageTargetRuntime>unix</PackageTargetRuntime>
-        <SupportedOSPlatforms>unix</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'Linux'">
@@ -19,7 +17,6 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsLinux>true</TargetsLinux>
         <PackageTargetRuntime>linux</PackageTargetRuntime>
-        <SupportedOSPlatforms>unix;linux</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'Android'">
@@ -28,7 +25,6 @@
         <TargetsLinux>true</TargetsLinux>
         <TargetsAndroid>true</TargetsAndroid>
         <PackageTargetRuntime>android</PackageTargetRuntime>
-        <SupportedOSPlatforms>unix;linux;android</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'OSX'">
@@ -36,7 +32,6 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsOSX>true</TargetsOSX>
         <PackageTargetRuntime>osx</PackageTargetRuntime>
-        <SupportedOSPlatforms>unix;macos</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'tvOS'">
@@ -44,7 +39,6 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetstvOS>true</TargetstvOS>
         <PackageTargetRuntime>tvos</PackageTargetRuntime>
-        <SupportedOSPlatforms>unix;tvos</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'iOS'">
@@ -52,7 +46,6 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsiOS>true</TargetsiOS>
         <PackageTargetRuntime>ios</PackageTargetRuntime>
-        <SupportedOSPlatforms>unix;ios</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'FreeBSD'">
@@ -60,7 +53,6 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsFreeBSD>true</TargetsFreeBSD>
         <PackageTargetRuntime>freebsd</PackageTargetRuntime>
-        <SupportedOSPlatforms>unix;freebsd</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'NetBSD'">
@@ -68,7 +60,6 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsNetBSD>true</TargetsNetBSD>
         <PackageTargetRuntime>netbsd</PackageTargetRuntime>
-        <SupportedOSPlatforms>unix</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'illumos'">
@@ -76,7 +67,6 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsIllumos>true</TargetsIllumos>
         <PackageTargetRuntime>illumos</PackageTargetRuntime>
-        <SupportedOSPlatforms>unix</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'Solaris'">
@@ -84,7 +74,6 @@
         <TargetsUnix>true</TargetsUnix>
         <TargetsSolaris>true</TargetsSolaris>
         <PackageTargetRuntime>solaris</PackageTargetRuntime>
-        <SupportedOSPlatforms>unix</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == 'Browser'">
diff --git a/src/libraries/System.Net.Sockets/Directory.Build.props b/src/libraries/System.Net.Sockets/Directory.Build.props
index 51f6852d7ef7b3..1f799d605feb93 100644
--- a/src/libraries/System.Net.Sockets/Directory.Build.props
+++ b/src/libraries/System.Net.Sockets/Directory.Build.props
@@ -3,6 +3,6 @@
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
     <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms Condition="'$(TargetsWindows)' != 'true'">browser</UnsupportedOSPlatforms>
+    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
   </PropertyGroup>
 </Project>

From 7e95fd618c6f69bd08960fe9c283a5ab8c178d5c Mon Sep 17 00:00:00 2001
From: Jeff Handley <jeff.handley@microsoft.com>
Date: Sun, 23 Aug 2020 22:40:50 -0700
Subject: [PATCH 3/6] Undo remaining platform properties that had been added

---
 eng/targetframeworksuffix.props                                  | 1 -
 .../src/Microsoft.Extensions.Logging.EventLog.csproj             | 1 -
 2 files changed, 2 deletions(-)

diff --git a/eng/targetframeworksuffix.props b/eng/targetframeworksuffix.props
index af6dc3f2960ce3..96cd8db859c378 100644
--- a/eng/targetframeworksuffix.props
+++ b/eng/targetframeworksuffix.props
@@ -80,7 +80,6 @@
       <PropertyGroup>
         <TargetsBrowser>true</TargetsBrowser>
         <PackageTargetRuntime>browser</PackageTargetRuntime>
-        <SupportedOSPlatforms>browser</SupportedOSPlatforms>
       </PropertyGroup>
     </When>
     <When Condition="'$(TargetFrameworkSuffix)' == ''">
diff --git a/src/libraries/Microsoft.Extensions.Logging.EventLog/src/Microsoft.Extensions.Logging.EventLog.csproj b/src/libraries/Microsoft.Extensions.Logging.EventLog/src/Microsoft.Extensions.Logging.EventLog.csproj
index 66afaf579451d4..9ae5802d972d1a 100644
--- a/src/libraries/Microsoft.Extensions.Logging.EventLog/src/Microsoft.Extensions.Logging.EventLog.csproj
+++ b/src/libraries/Microsoft.Extensions.Logging.EventLog/src/Microsoft.Extensions.Logging.EventLog.csproj
@@ -3,7 +3,6 @@
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;net461</TargetFrameworks>
     <EnableDefaultItems>true</EnableDefaultItems>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
   </PropertyGroup>
 
   <ItemGroup>

From 2feacc8f4576120b2f7d18b6af665d09b9e66369 Mon Sep 17 00:00:00 2001
From: Jeff Handley <jeff.handley@microsoft.com>
Date: Tue, 25 Aug 2020 00:38:03 -0700
Subject: [PATCH 4/6] Rename MSBuild properties for clarity; add a warning for
 conflicting attributes

---
 eng/versioning.targets                                    | 8 ++++++--
 src/libraries/Directory.Build.targets                     | 2 +-
 .../Directory.Build.props                                 | 2 +-
 .../Microsoft.Win32.Registry/Directory.Build.props        | 2 +-
 .../Microsoft.Win32.SystemEvents/Directory.Build.props    | 2 +-
 src/libraries/System.Data.Odbc/Directory.Build.props      | 3 +--
 src/libraries/System.Data.OleDb/Directory.Build.props     | 2 +-
 .../System.Diagnostics.EventLog/Directory.Build.props     | 2 +-
 .../Directory.Build.props                                 | 2 +-
 .../Directory.Build.props                                 | 2 +-
 .../Directory.Build.props                                 | 3 +--
 .../System.DirectoryServices/Directory.Build.props        | 2 +-
 src/libraries/System.Drawing.Common/Directory.Build.props | 3 +--
 .../Directory.Build.props                                 | 2 +-
 .../System.IO.Pipes.AccessControl/Directory.Build.props   | 2 +-
 src/libraries/System.IO.Ports/Directory.Build.props       | 3 +--
 src/libraries/System.Management/Directory.Build.props     | 2 +-
 .../System.Net.Http.WinHttpHandler/Directory.Build.props  | 2 +-
 src/libraries/System.Net.Mail/Directory.Build.props       | 3 +--
 .../System.Net.NetworkInformation/Directory.Build.props   | 3 +--
 src/libraries/System.Net.Ping/Directory.Build.props       | 3 +--
 src/libraries/System.Net.Requests/Directory.Build.props   | 3 +--
 src/libraries/System.Net.Security/Directory.Build.props   | 3 +--
 src/libraries/System.Net.Sockets/Directory.Build.props    | 3 +--
 src/libraries/System.Net.WebClient/Directory.Build.props  | 3 +--
 .../System.Security.AccessControl/Directory.Build.props   | 2 +-
 .../Directory.Build.props                                 | 2 +-
 .../Directory.Build.props                                 | 3 +--
 .../Directory.Build.props                                 | 3 +--
 .../Directory.Build.props                                 | 2 +-
 .../Directory.Build.props                                 | 3 +--
 .../Directory.Build.props                                 | 3 +--
 .../Directory.Build.props                                 | 2 +-
 .../Directory.Build.props                                 | 3 +--
 .../Directory.Build.props                                 | 3 +--
 .../Directory.Build.props                                 | 2 +-
 .../Directory.Build.props                                 | 2 +-
 .../System.Threading.AccessControl/Directory.Build.props  | 2 +-
 .../System.Threading.Overlapped/Directory.Build.props     | 2 +-
 .../System.Windows.Extensions/Directory.Build.props       | 2 +-
 40 files changed, 45 insertions(+), 58 deletions(-)

diff --git a/eng/versioning.targets b/eng/versioning.targets
index a55f19c34a0356..969db338595fe7 100644
--- a/eng/versioning.targets
+++ b/eng/versioning.targets
@@ -24,19 +24,23 @@
 
   <!-- Adds SupportedOSPlatform or UnsupportedOSPlatform attributes -->
   <ItemGroup Condition="'$(IsTestProject)' != 'true'">
-    <_supportedOSPlatforms Include="$(SupportedOSPlatforms)" />
-    <_unsupportedOSPlatforms Include="$(UnsupportedOSPlatforms)" />
+    <_supportedOSPlatforms Include="$(AssemblySupportedOSPlatformAttributes)" />
+    <_unsupportedOSPlatforms Include="$(AssemblyUnsupportedOSPlatformAttributes)" />
   </ItemGroup>
 
   <Target Name="AddAssemblyOSPlatformAttributes" BeforeTargets="GenerateAssemblyInfo" AfterTargets="PrepareForBuild">
     <ItemGroup>
+      <!-- When there are Supported OSPlatforms, transform each of those into an attribute -->
       <AssemblyAttribute Include="System.Runtime.Versioning.SupportedOSPlatform" Condition="'@(_supportedOSPlatforms)' != ''">
         <_Parameter1>%(_supportedOSPlatforms.Identity)</_Parameter1>
       </AssemblyAttribute>
+      <!-- When there are not any Supported OSPlatforms, but there are Unsupported OSPlatforms, transform each of those into an attribute -->
       <AssemblyAttribute Include="System.Runtime.Versioning.UnsupportedOSPlatform" Condition="'@(_supportedOSPlatforms)' == '' and '@(_unsupportedOSPlatforms)' != ''">
         <_Parameter1>%(_unsupportedOSPlatforms.Identity)</_Parameter1>
       </AssemblyAttribute>
     </ItemGroup>
+    <Warning Condition="'@(_supportedOSPlatforms)' != '' and '@(_unsupportedOSPlatforms)' != ''"
+             Text="The 'AssemblySupportedOSPlatformAttributes' and 'AssemblyUnsupportedOSPlatformAttributes' properties cannot both be defined; only the AssemblySupportedOSPlatformAttributes was used." />
   </Target>
 
   <Target Name="DecideIfWeNeedToIncludeDllSafeSearchPathAttribute"
diff --git a/src/libraries/Directory.Build.targets b/src/libraries/Directory.Build.targets
index aa5552fdca300d..f2e2373b8a9968 100644
--- a/src/libraries/Directory.Build.targets
+++ b/src/libraries/Directory.Build.targets
@@ -243,7 +243,7 @@
 
   <!-- Adds System.Runtime.Versioning*Platform* annotation attributes to < .NET 5 builds -->
   <Choose>
-    <When Condition="('$(IncludePlatformAttributes)' == 'true' or '$(SupportedOSPlatforms)' != '' or '$(UnsupportedOSPlatforms)' != '') and ('$(TargetFrameworkIdentifier)' != '.NETCoreApp' or $([MSBuild]::VersionLessThan($(TargetFrameworkVersion), '5.0')))">
+    <When Condition="('$(IncludePlatformAttributes)' == 'true' or '$(AssemblySupportedOSPlatformAttributes)' != '' or '$(AssemblyUnsupportedOSPlatformAttributes)' != '') and ('$(TargetFrameworkIdentifier)' != '.NETCoreApp' or $([MSBuild]::VersionLessThan($(TargetFrameworkVersion), '5.0')))">
       <ItemGroup>
         <Compile Include="$(CoreLibSharedDir)System\Runtime\Versioning\PlatformAttributes.cs" Link="System\Runtime\Versioning\PlatformAttributes.cs" />
       </ItemGroup>
diff --git a/src/libraries/Microsoft.Win32.Registry.AccessControl/Directory.Build.props b/src/libraries/Microsoft.Win32.Registry.AccessControl/Directory.Build.props
index 709a22a7537088..983c525000396f 100644
--- a/src/libraries/Microsoft.Win32.Registry.AccessControl/Directory.Build.props
+++ b/src/libraries/Microsoft.Win32.Registry.AccessControl/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/Microsoft.Win32.Registry/Directory.Build.props b/src/libraries/Microsoft.Win32.Registry/Directory.Build.props
index 709a22a7537088..983c525000396f 100644
--- a/src/libraries/Microsoft.Win32.Registry/Directory.Build.props
+++ b/src/libraries/Microsoft.Win32.Registry/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/Microsoft.Win32.SystemEvents/Directory.Build.props b/src/libraries/Microsoft.Win32.SystemEvents/Directory.Build.props
index e7e8cb9ac081be..9cda6897812c22 100644
--- a/src/libraries/Microsoft.Win32.SystemEvents/Directory.Build.props
+++ b/src/libraries/Microsoft.Win32.SystemEvents/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Data.Odbc/Directory.Build.props b/src/libraries/System.Data.Odbc/Directory.Build.props
index 4784967b7f86ac..374d373973ccd8 100644
--- a/src/libraries/System.Data.Odbc/Directory.Build.props
+++ b/src/libraries/System.Data.Odbc/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Data.OleDb/Directory.Build.props b/src/libraries/System.Data.OleDb/Directory.Build.props
index 6c6a6c1b425414..77e629a6c3b9b7 100644
--- a/src/libraries/System.Data.OleDb/Directory.Build.props
+++ b/src/libraries/System.Data.OleDb/Directory.Build.props
@@ -1,6 +1,6 @@
 <Project>
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Diagnostics.EventLog/Directory.Build.props b/src/libraries/System.Diagnostics.EventLog/Directory.Build.props
index e7e8cb9ac081be..9cda6897812c22 100644
--- a/src/libraries/System.Diagnostics.EventLog/Directory.Build.props
+++ b/src/libraries/System.Diagnostics.EventLog/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Diagnostics.PerformanceCounter/Directory.Build.props b/src/libraries/System.Diagnostics.PerformanceCounter/Directory.Build.props
index e7e8cb9ac081be..9cda6897812c22 100644
--- a/src/libraries/System.Diagnostics.PerformanceCounter/Directory.Build.props
+++ b/src/libraries/System.Diagnostics.PerformanceCounter/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.DirectoryServices.AccountManagement/Directory.Build.props b/src/libraries/System.DirectoryServices.AccountManagement/Directory.Build.props
index 4cf151da3064fc..5ae5653515c730 100644
--- a/src/libraries/System.DirectoryServices.AccountManagement/Directory.Build.props
+++ b/src/libraries/System.DirectoryServices.AccountManagement/Directory.Build.props
@@ -6,6 +6,6 @@
          to a different assembly. -->
     <AssemblyVersion>4.0.0.0</AssemblyVersion>
     <StrongNameKeyId>ECMA</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.DirectoryServices.Protocols/Directory.Build.props b/src/libraries/System.DirectoryServices.Protocols/Directory.Build.props
index cad73bcaafa103..a63a775e02f4de 100644
--- a/src/libraries/System.DirectoryServices.Protocols/Directory.Build.props
+++ b/src/libraries/System.DirectoryServices.Protocols/Directory.Build.props
@@ -6,7 +6,6 @@
          to a different assembly. -->
     <AssemblyVersion>4.0.0.0</AssemblyVersion>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.DirectoryServices/Directory.Build.props b/src/libraries/System.DirectoryServices/Directory.Build.props
index bfa544ca6f649e..7ef0bee9ab6420 100644
--- a/src/libraries/System.DirectoryServices/Directory.Build.props
+++ b/src/libraries/System.DirectoryServices/Directory.Build.props
@@ -6,6 +6,6 @@
          to a different assembly. -->
     <AssemblyVersion>4.0.0.0</AssemblyVersion>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Drawing.Common/Directory.Build.props b/src/libraries/System.Drawing.Common/Directory.Build.props
index 4784967b7f86ac..374d373973ccd8 100644
--- a/src/libraries/System.Drawing.Common/Directory.Build.props
+++ b/src/libraries/System.Drawing.Common/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.IO.FileSystem.AccessControl/Directory.Build.props b/src/libraries/System.IO.FileSystem.AccessControl/Directory.Build.props
index 709a22a7537088..983c525000396f 100644
--- a/src/libraries/System.IO.FileSystem.AccessControl/Directory.Build.props
+++ b/src/libraries/System.IO.FileSystem.AccessControl/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.IO.Pipes.AccessControl/Directory.Build.props b/src/libraries/System.IO.Pipes.AccessControl/Directory.Build.props
index 709a22a7537088..983c525000396f 100644
--- a/src/libraries/System.IO.Pipes.AccessControl/Directory.Build.props
+++ b/src/libraries/System.IO.Pipes.AccessControl/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.IO.Ports/Directory.Build.props b/src/libraries/System.IO.Ports/Directory.Build.props
index 4784967b7f86ac..374d373973ccd8 100644
--- a/src/libraries/System.IO.Ports/Directory.Build.props
+++ b/src/libraries/System.IO.Ports/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Management/Directory.Build.props b/src/libraries/System.Management/Directory.Build.props
index bfa544ca6f649e..7ef0bee9ab6420 100644
--- a/src/libraries/System.Management/Directory.Build.props
+++ b/src/libraries/System.Management/Directory.Build.props
@@ -6,6 +6,6 @@
          to a different assembly. -->
     <AssemblyVersion>4.0.0.0</AssemblyVersion>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Net.Http.WinHttpHandler/Directory.Build.props b/src/libraries/System.Net.Http.WinHttpHandler/Directory.Build.props
index 709a22a7537088..983c525000396f 100644
--- a/src/libraries/System.Net.Http.WinHttpHandler/Directory.Build.props
+++ b/src/libraries/System.Net.Http.WinHttpHandler/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Net.Mail/Directory.Build.props b/src/libraries/System.Net.Mail/Directory.Build.props
index 4784967b7f86ac..374d373973ccd8 100644
--- a/src/libraries/System.Net.Mail/Directory.Build.props
+++ b/src/libraries/System.Net.Mail/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Net.NetworkInformation/Directory.Build.props b/src/libraries/System.Net.NetworkInformation/Directory.Build.props
index ce244cbea56199..f499e8dc29a4b4 100644
--- a/src/libraries/System.Net.NetworkInformation/Directory.Build.props
+++ b/src/libraries/System.Net.NetworkInformation/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Net.Ping/Directory.Build.props b/src/libraries/System.Net.Ping/Directory.Build.props
index ce244cbea56199..f499e8dc29a4b4 100644
--- a/src/libraries/System.Net.Ping/Directory.Build.props
+++ b/src/libraries/System.Net.Ping/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Net.Requests/Directory.Build.props b/src/libraries/System.Net.Requests/Directory.Build.props
index ce244cbea56199..f499e8dc29a4b4 100644
--- a/src/libraries/System.Net.Requests/Directory.Build.props
+++ b/src/libraries/System.Net.Requests/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Net.Security/Directory.Build.props b/src/libraries/System.Net.Security/Directory.Build.props
index ce244cbea56199..f499e8dc29a4b4 100644
--- a/src/libraries/System.Net.Security/Directory.Build.props
+++ b/src/libraries/System.Net.Security/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Net.Sockets/Directory.Build.props b/src/libraries/System.Net.Sockets/Directory.Build.props
index 1f799d605feb93..7562009d73d4d0 100644
--- a/src/libraries/System.Net.Sockets/Directory.Build.props
+++ b/src/libraries/System.Net.Sockets/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
diff --git a/src/libraries/System.Net.WebClient/Directory.Build.props b/src/libraries/System.Net.WebClient/Directory.Build.props
index 4784967b7f86ac..374d373973ccd8 100644
--- a/src/libraries/System.Net.WebClient/Directory.Build.props
+++ b/src/libraries/System.Net.WebClient/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Security.AccessControl/Directory.Build.props b/src/libraries/System.Security.AccessControl/Directory.Build.props
index 709a22a7537088..983c525000396f 100644
--- a/src/libraries/System.Security.AccessControl/Directory.Build.props
+++ b/src/libraries/System.Security.AccessControl/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Security.Cryptography.Cng/Directory.Build.props b/src/libraries/System.Security.Cryptography.Cng/Directory.Build.props
index 709a22a7537088..983c525000396f 100644
--- a/src/libraries/System.Security.Cryptography.Cng/Directory.Build.props
+++ b/src/libraries/System.Security.Cryptography.Cng/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Security.Cryptography.Csp/Directory.Build.props b/src/libraries/System.Security.Cryptography.Csp/Directory.Build.props
index ce244cbea56199..f499e8dc29a4b4 100644
--- a/src/libraries/System.Security.Cryptography.Csp/Directory.Build.props
+++ b/src/libraries/System.Security.Cryptography.Csp/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Security.Cryptography.Encoding/Directory.Build.props b/src/libraries/System.Security.Cryptography.Encoding/Directory.Build.props
index ce244cbea56199..f499e8dc29a4b4 100644
--- a/src/libraries/System.Security.Cryptography.Encoding/Directory.Build.props
+++ b/src/libraries/System.Security.Cryptography.Encoding/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Security.Cryptography.OpenSsl/Directory.Build.props b/src/libraries/System.Security.Cryptography.OpenSsl/Directory.Build.props
index 05ae3c4dc8f2ca..a6f5cb84cc6a1f 100644
--- a/src/libraries/System.Security.Cryptography.OpenSsl/Directory.Build.props
+++ b/src/libraries/System.Security.Cryptography.OpenSsl/Directory.Build.props
@@ -3,6 +3,6 @@
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
     <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>windows;browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>windows;browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Security.Cryptography.Pkcs/Directory.Build.props b/src/libraries/System.Security.Cryptography.Pkcs/Directory.Build.props
index 1f799d605feb93..7562009d73d4d0 100644
--- a/src/libraries/System.Security.Cryptography.Pkcs/Directory.Build.props
+++ b/src/libraries/System.Security.Cryptography.Pkcs/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
diff --git a/src/libraries/System.Security.Cryptography.Primitives/Directory.Build.props b/src/libraries/System.Security.Cryptography.Primitives/Directory.Build.props
index ce244cbea56199..f499e8dc29a4b4 100644
--- a/src/libraries/System.Security.Cryptography.Primitives/Directory.Build.props
+++ b/src/libraries/System.Security.Cryptography.Primitives/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Security.Cryptography.ProtectedData/Directory.Build.props b/src/libraries/System.Security.Cryptography.ProtectedData/Directory.Build.props
index 37ee66d7748582..4531f991ab717f 100644
--- a/src/libraries/System.Security.Cryptography.ProtectedData/Directory.Build.props
+++ b/src/libraries/System.Security.Cryptography.ProtectedData/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
diff --git a/src/libraries/System.Security.Cryptography.X509Certificates/Directory.Build.props b/src/libraries/System.Security.Cryptography.X509Certificates/Directory.Build.props
index ce244cbea56199..f499e8dc29a4b4 100644
--- a/src/libraries/System.Security.Cryptography.X509Certificates/Directory.Build.props
+++ b/src/libraries/System.Security.Cryptography.X509Certificates/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Security.Cryptography.Xml/Directory.Build.props b/src/libraries/System.Security.Cryptography.Xml/Directory.Build.props
index 4784967b7f86ac..374d373973ccd8 100644
--- a/src/libraries/System.Security.Cryptography.Xml/Directory.Build.props
+++ b/src/libraries/System.Security.Cryptography.Xml/Directory.Build.props
@@ -2,7 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <IncludePlatformAttributes>true</IncludePlatformAttributes>
-    <UnsupportedOSPlatforms>browser</UnsupportedOSPlatforms>
+    <AssemblyUnsupportedOSPlatformAttributes>browser</AssemblyUnsupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Security.Principal.Windows/Directory.Build.props b/src/libraries/System.Security.Principal.Windows/Directory.Build.props
index 709a22a7537088..983c525000396f 100644
--- a/src/libraries/System.Security.Principal.Windows/Directory.Build.props
+++ b/src/libraries/System.Security.Principal.Windows/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.ServiceProcess.ServiceController/Directory.Build.props b/src/libraries/System.ServiceProcess.ServiceController/Directory.Build.props
index 709a22a7537088..983c525000396f 100644
--- a/src/libraries/System.ServiceProcess.ServiceController/Directory.Build.props
+++ b/src/libraries/System.ServiceProcess.ServiceController/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Threading.AccessControl/Directory.Build.props b/src/libraries/System.Threading.AccessControl/Directory.Build.props
index 709a22a7537088..983c525000396f 100644
--- a/src/libraries/System.Threading.AccessControl/Directory.Build.props
+++ b/src/libraries/System.Threading.AccessControl/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Threading.Overlapped/Directory.Build.props b/src/libraries/System.Threading.Overlapped/Directory.Build.props
index 709a22a7537088..983c525000396f 100644
--- a/src/libraries/System.Threading.Overlapped/Directory.Build.props
+++ b/src/libraries/System.Threading.Overlapped/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Microsoft</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file
diff --git a/src/libraries/System.Windows.Extensions/Directory.Build.props b/src/libraries/System.Windows.Extensions/Directory.Build.props
index e7e8cb9ac081be..9cda6897812c22 100644
--- a/src/libraries/System.Windows.Extensions/Directory.Build.props
+++ b/src/libraries/System.Windows.Extensions/Directory.Build.props
@@ -2,6 +2,6 @@
   <Import Project="..\Directory.Build.props" />
   <PropertyGroup>
     <StrongNameKeyId>Open</StrongNameKeyId>
-    <SupportedOSPlatforms>windows</SupportedOSPlatforms>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 </Project>
\ No newline at end of file

From 66a0773654c7b67136f3d88291623c91381739dc Mon Sep 17 00:00:00 2001
From: Jeff Handley <jeff.handley@microsoft.com>
Date: Tue, 25 Aug 2020 01:36:43 -0700
Subject: [PATCH 5/6] Fix some platform compat analyzer warnings

---
 eng/versioning.targets                                    | 8 +++++++-
 src/libraries/Microsoft.Extensions.Hosting/src/Host.cs    | 3 +++
 .../ref/Microsoft.Extensions.Logging.EventLog.csproj      | 1 +
 .../src/Microsoft.Extensions.Logging.EventLog.csproj      | 1 +
 .../src/System/Net/Sockets/TCPListener.cs                 | 3 ++-
 5 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/eng/versioning.targets b/eng/versioning.targets
index 969db338595fe7..4760b2d9954273 100644
--- a/eng/versioning.targets
+++ b/eng/versioning.targets
@@ -22,10 +22,16 @@
     </AssemblyMetadata>
   </ItemGroup>
 
+  <!-- Sets SupportedOSPlatform=windows when targeting windows and using PlatformAttributes or defining UnsupportedOSPlatforms -->
+  <PropertyGroup Condition="'$(IsTestProject)' != 'true' and '$(AssemblySupportedOSPlatformAttributes)' == '' and ('$(IncludePlatformAttributes)' == 'true' or '$(AssemblyUnsupportedOSPlatformAttributes)' != '')">
+    <AssemblySupportedOSPlatformAttributes Condition="'$(TargetsWindows)' == 'true'">windows</AssemblySupportedOSPlatformAttributes>
+    <_assemblySupportedOSPlatformAttributesOverride>true</_assemblySupportedOSPlatformAttributesOverride>
+  </PropertyGroup>
+
   <!-- Adds SupportedOSPlatform or UnsupportedOSPlatform attributes -->
   <ItemGroup Condition="'$(IsTestProject)' != 'true'">
     <_supportedOSPlatforms Include="$(AssemblySupportedOSPlatformAttributes)" />
-    <_unsupportedOSPlatforms Include="$(AssemblyUnsupportedOSPlatformAttributes)" />
+    <_unsupportedOSPlatforms Include="$(AssemblyUnsupportedOSPlatformAttributes)" Condition="'$(_assemblySupportedOSPlatformAttributesOverride)' != 'true'" />
   </ItemGroup>
 
   <Target Name="AddAssemblyOSPlatformAttributes" BeforeTargets="GenerateAssemblyInfo" AfterTargets="PrepareForBuild">
diff --git a/src/libraries/Microsoft.Extensions.Hosting/src/Host.cs b/src/libraries/Microsoft.Extensions.Hosting/src/Host.cs
index f1d095ab0c7e23..c26aee9153c659 100644
--- a/src/libraries/Microsoft.Extensions.Hosting/src/Host.cs
+++ b/src/libraries/Microsoft.Extensions.Hosting/src/Host.cs
@@ -111,8 +111,11 @@ public static IHostBuilder CreateDefaultBuilder(string[] args)
 
                 if (isWindows)
                 {
+#pragma warning disable CA1416 // Platform compat analyzer
                     // Add the EventLogLoggerProvider on windows machines
                     logging.AddEventLog();
+#pragma warning restore CA1416 // Platform compat analyzer
+
                 }
 
                 logging.Configure(options =>
diff --git a/src/libraries/Microsoft.Extensions.Logging.EventLog/ref/Microsoft.Extensions.Logging.EventLog.csproj b/src/libraries/Microsoft.Extensions.Logging.EventLog/ref/Microsoft.Extensions.Logging.EventLog.csproj
index 41ab6a29cfaf49..4308166c933318 100644
--- a/src/libraries/Microsoft.Extensions.Logging.EventLog/ref/Microsoft.Extensions.Logging.EventLog.csproj
+++ b/src/libraries/Microsoft.Extensions.Logging.EventLog/ref/Microsoft.Extensions.Logging.EventLog.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;net461</TargetFrameworks>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="Microsoft.Extensions.Logging.EventLog.cs" />
diff --git a/src/libraries/Microsoft.Extensions.Logging.EventLog/src/Microsoft.Extensions.Logging.EventLog.csproj b/src/libraries/Microsoft.Extensions.Logging.EventLog/src/Microsoft.Extensions.Logging.EventLog.csproj
index 9ae5802d972d1a..bdc142c15ca2be 100644
--- a/src/libraries/Microsoft.Extensions.Logging.EventLog/src/Microsoft.Extensions.Logging.EventLog.csproj
+++ b/src/libraries/Microsoft.Extensions.Logging.EventLog/src/Microsoft.Extensions.Logging.EventLog.csproj
@@ -3,6 +3,7 @@
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;net461</TargetFrameworks>
     <EnableDefaultItems>true</EnableDefaultItems>
+    <AssemblySupportedOSPlatformAttributes>windows</AssemblySupportedOSPlatformAttributes>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/libraries/System.Net.Sockets/src/System/Net/Sockets/TCPListener.cs b/src/libraries/System.Net.Sockets/src/System/Net/Sockets/TCPListener.cs
index 6c623fec1cfb99..68c550b09a6387 100644
--- a/src/libraries/System.Net.Sockets/src/System/Net/Sockets/TCPListener.cs
+++ b/src/libraries/System.Net.Sockets/src/System/Net/Sockets/TCPListener.cs
@@ -262,6 +262,7 @@ public static TcpListener Create(int port)
             return listener;
         }
 
+        [SupportedOSPlatform("windows")]
         private void SetIPProtectionLevel(bool allowed)
             => _serverSocket!.SetIPProtectionLevel(allowed ? IPProtectionLevel.Unrestricted : IPProtectionLevel.EdgeRestricted);
 
@@ -274,7 +275,7 @@ private void CreateNewSocketIfNeeded()
                 _serverSocket.ExclusiveAddressUse = true;
             }
 
-            if (_allowNatTraversal != null)
+            if (_allowNatTraversal != null && OperatingSystem.IsWindows())
             {
                 SetIPProtectionLevel(_allowNatTraversal.GetValueOrDefault());
                 _allowNatTraversal = null; // Reset value to avoid affecting more sockets

From f75b56c17fa06426bc10cb901f2e491834cdd528 Mon Sep 17 00:00:00 2001
From: Jeff Handley <jeff.handley@microsoft.com>
Date: Tue, 25 Aug 2020 01:50:34 -0700
Subject: [PATCH 6/6] Remove inferred SupportedOSPlatform attribute for windows
 builds

---
 eng/versioning.targets | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/eng/versioning.targets b/eng/versioning.targets
index 4760b2d9954273..3aec5952541daf 100644
--- a/eng/versioning.targets
+++ b/eng/versioning.targets
@@ -22,12 +22,6 @@
     </AssemblyMetadata>
   </ItemGroup>
 
-  <!-- Sets SupportedOSPlatform=windows when targeting windows and using PlatformAttributes or defining UnsupportedOSPlatforms -->
-  <PropertyGroup Condition="'$(IsTestProject)' != 'true' and '$(AssemblySupportedOSPlatformAttributes)' == '' and ('$(IncludePlatformAttributes)' == 'true' or '$(AssemblyUnsupportedOSPlatformAttributes)' != '')">
-    <AssemblySupportedOSPlatformAttributes Condition="'$(TargetsWindows)' == 'true'">windows</AssemblySupportedOSPlatformAttributes>
-    <_assemblySupportedOSPlatformAttributesOverride>true</_assemblySupportedOSPlatformAttributesOverride>
-  </PropertyGroup>
-
   <!-- Adds SupportedOSPlatform or UnsupportedOSPlatform attributes -->
   <ItemGroup Condition="'$(IsTestProject)' != 'true'">
     <_supportedOSPlatforms Include="$(AssemblySupportedOSPlatformAttributes)" />