From d9c1aa38c71743f4b9a897a72167d02513ec509f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20Strehovsk=C3=BD?= <michals@microsoft.com>
Date: Tue, 26 Feb 2019 14:50:28 +0100
Subject: [PATCH] Use partial crossgen for select assemblies on Linux

Measurements show that doing partial crossgen on these assemblies captures about two thirds of the size savings we could achieve by partially crossgenning everything.

Only doing this for Linux, since Linux containers are more size-conscious.
---
 .../src/Microsoft.NETCore.App.depproj              | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/pkg/projects/Microsoft.NETCore.App/src/Microsoft.NETCore.App.depproj b/src/pkg/projects/Microsoft.NETCore.App/src/Microsoft.NETCore.App.depproj
index fb1f3ce972..80b88e2b4a 100644
--- a/src/pkg/projects/Microsoft.NETCore.App/src/Microsoft.NETCore.App.depproj
+++ b/src/pkg/projects/Microsoft.NETCore.App/src/Microsoft.NETCore.App.depproj
@@ -276,11 +276,23 @@
       <_crossGenArgs Include="-JITPath $(_jitPath)" />
     </ItemGroup>
 
+    <PropertyGroup>
+      <_partialCrossgenFlag>0</_partialCrossgenFlag>
+    </PropertyGroup>
+
+    <!-- Measurements show that doing partial crossgen on these assemblies captures a lot of the potential size saving. -->
+    <PropertyGroup Condition="'$(OSGroup)' == 'Linux'">
+      <_partialCrossgenFlag Condition="'%(_filesToCrossGen.FileName)' == 'System.ComponentModel.TypeConverter'">1</_partialCrossgenFlag>
+      <_partialCrossgenFlag Condition="'%(_filesToCrossGen.FileName)' == 'System.Linq.Expressions'">1</_partialCrossgenFlag>
+      <_partialCrossgenFlag Condition="'%(_filesToCrossGen.FileName)' == 'System.Private.DataContractSerialization'">1</_partialCrossgenFlag>
+      <_partialCrossgenFlag Condition="'%(_filesToCrossGen.FileName)' == 'System.Private.Xml'">1</_partialCrossgenFlag>
+    </PropertyGroup>
+
     <MakeDir Directories="$(_crossGenIntermediatePath)" />
     <MakeDir Directories="$([System.IO.Path]::GetDirectoryName('%(_filesToCrossGen.CrossGenedPath)'))" />
     <WriteLinesToFile File="$(_crossGenResponseFile)" Lines="@(_crossGenArgs)" Overwrite="true" />
 
-    <Exec Command="$(_crossGenPath) @$(_crossGenResponseFile)" WorkingDirectory="$(_clrDirectory)" EnvironmentVariables="COMPlus_PartialNGen=0" />
+    <Exec Command="$(_crossGenPath) @$(_crossGenResponseFile)" WorkingDirectory="$(_clrDirectory)" EnvironmentVariables="COMPlus_PartialNGen=$(_partialCrossgenFlag)" />
   </Target>
 
   <Target Name="CreateCrossGenSymbols"