Recognize TrimMode=partial in ILCompiler targets (#71117)

This should root all non-trimmable assemblies, same as TrimmerDefaultAction=copy.

We still support consuming ILCompiler through NuGet when targeting .NET 6, so recognize the old thing too. We might want to cut the .NET 6 support close to RC and at that time TrimmerDefaultAction handling can go away.

Related: https://github.com/dotnet/linker/pull/2856.

diff --git a/src/coreclr/nativeaot/BuildIntegration/Microsoft.NETCore.Native.targets b/src/coreclr/nativeaot/BuildIntegration/Microsoft.NETCore.Native.targets
index 1c99b64..52ac04a 100644 (file)
--- a/src/coreclr/nativeaot/BuildIntegration/Microsoft.NETCore.Native.targets
+++ b/src/coreclr/nativeaot/BuildIntegration/Microsoft.NETCore.Native.targets
@@ -246,7 +246,7 @@ The .NET Foundation licenses this file to you under the MIT license.
       <IlcArg Include="@(_IlcConditionallyRootedAssemblies->'--conditionalroot:%(Identity)')" />
       <IlcArg Include="@(_IlcTrimmedAssemblies->'--trim:%(Identity)')" />
       <IlcArg Include="@(_IlcNoSingleWarnAssemblies->'--nosinglewarnassembly:%(Filename)')" />
-      <IlcArg Condition="'$(TrimmerDefaultAction)' == 'copyused' or '$(TrimmerDefaultAction)' == 'copy'" Include="--defaultrooting" />
+      <IlcArg Condition="'$(TrimmerDefaultAction)' == 'copyused' or '$(TrimmerDefaultAction)' == 'copy' or '$(TrimMode)' == 'partial'" Include="--defaultrooting" />
       <IlcArg Include="--resilient" />
 
       <IlcArg Condition="$(IlcDisableReflection) == 'true'" Include="--feature:System.Reflection.IsReflectionExecutionAvailable=false" />