From e9caaa773cbdfeab9a4612fe819b5745e4984e84 Mon Sep 17 00:00:00 2001
From: Sven Boemer <sbomer@gmail.com>
Date: Wed, 17 Feb 2021 10:58:31 -0800
Subject: [PATCH 1/2] Annotate framework assemblies as trimmable

This will opt them into trimming with the behavior described at https://github.com/mono/linker/blob/main/docs/design/trimmed-assemblies.md#assemblymetadataistrimmable-true.
---
 eng/versioning.targets                                         | 3 +++
 .../System.Private.CoreLib/src/Internal/AssemblyAttributes.cs  | 1 +
 2 files changed, 4 insertions(+)

diff --git a/eng/versioning.targets b/eng/versioning.targets
index 468f236c5f482..cb293a96eb03c 100644
--- a/eng/versioning.targets
+++ b/eng/versioning.targets
@@ -20,6 +20,9 @@
     <AssemblyMetadata Include="PreferInbox">
       <Value>True</Value>
     </AssemblyMetadata>
+    <AssemblyMetadata Include="IsTrimmable">
+      <Value>True</Value>
+    </AssemblyMetadata>
   </ItemGroup>
 
   <!-- Adds SupportedOSPlatform attribute for Windows Specific libraries -->
diff --git a/src/libraries/System.Private.CoreLib/src/Internal/AssemblyAttributes.cs b/src/libraries/System.Private.CoreLib/src/Internal/AssemblyAttributes.cs
index 0052cefef04f1..3c0b9479941ce 100644
--- a/src/libraries/System.Private.CoreLib/src/Internal/AssemblyAttributes.cs
+++ b/src/libraries/System.Private.CoreLib/src/Internal/AssemblyAttributes.cs
@@ -22,5 +22,6 @@
 
 [assembly: AssemblyMetadata("Serviceable", "True")]
 [assembly: AssemblyMetadata(".NETFrameworkAssembly", "")]
+[assembly: AssemblyMetadata("IsTrimmable", "True")]
 
 [assembly: NeutralResourcesLanguage("en-US")]

From d03327e62ddb7035442c9b803c699d1f8776e1bd Mon Sep 17 00:00:00 2001
From: Sven Boemer <sbomer@gmail.com>
Date: Thu, 18 Feb 2021 15:11:25 -0800
Subject: [PATCH 2/2] Add a condition to let projects opt out

A project just needs to set <SetIsTrimmable>false</SetIsTrimmable>, and
it won't get the trimmable metadata.

I also got rid of the SkipFrameworkAssemblyMetadata check since I don't
think the IsTrimmable metadata should be tied to whether we are building
a framework assembly, and this property was unused as far as I could tell.
---
 eng/versioning.targets | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/eng/versioning.targets b/eng/versioning.targets
index cb293a96eb03c..e6a3e7d1f0ad7 100644
--- a/eng/versioning.targets
+++ b/eng/versioning.targets
@@ -20,7 +20,7 @@
     <AssemblyMetadata Include="PreferInbox">
       <Value>True</Value>
     </AssemblyMetadata>
-    <AssemblyMetadata Include="IsTrimmable">
+    <AssemblyMetadata Include="IsTrimmable" Condition="'$(SetIsTrimmable)' != 'false'">
       <Value>True</Value>
     </AssemblyMetadata>
   </ItemGroup>
@@ -86,7 +86,7 @@
       </AssemblyAttribute>
 
       <AssemblyAttribute Include="System.Reflection.AssemblyMetadata"
-                         Condition="'$(SkipFrameworkAssemblyMetadata)' != 'true' and '@(AssemblyMetadata)' != ''">
+                         Condition="'@(AssemblyMetadata)' != ''">
         <_Parameter1>%(AssemblyMetadata.Identity)</_Parameter1>
         <_Parameter2>%(AssemblyMetadata.Value)</_Parameter2>
       </AssemblyAttribute>