From 614fa985259efe5bbf9323a495e98969b1ee2ef9 Mon Sep 17 00:00:00 2001
From: Omair Majid <omajid@redhat.com>
Date: Mon, 2 Apr 2018 12:36:48 -0400
Subject: [PATCH] Introduce a UseSystemLibraries option to use system libunwind

UseSystemLibraries lets users control if they want to use the system
versions of libraries or bundled libraries. The only use case where this
applies currently is coreclr's libunwind.
---
 dir.props          | 1 +
 repos/coreclr.proj | 1 +
 2 files changed, 2 insertions(+)

diff --git a/dir.props b/dir.props
index bf2c6b9379..edca00cb37 100644
--- a/dir.props
+++ b/dir.props
@@ -8,6 +8,7 @@
     <_IsBootstrapping Condition="'$(BootstrapBuildToolsDir)' != ''">true</_IsBootstrapping>
 
     <PortableBuild Condition="'$(PortableBuild)' == ''">false</PortableBuild>
+    <UseSystemLibraries Condition="'$(UseSystemLibraries)' == ''">true</UseSystemLibraries>
   </PropertyGroup>
 
   <PropertyGroup>
diff --git a/repos/coreclr.proj b/repos/coreclr.proj
index 936f7d8de7..9dad550ff3 100644
--- a/repos/coreclr.proj
+++ b/repos/coreclr.proj
@@ -4,6 +4,7 @@
   <PropertyGroup>
     <BuildArguments>$(Platform) $(Configuration) skiptests -PortableBuild=$(PortableBuild)</BuildArguments>
     <BuildArguments Condition="'$(OS)' != 'Windows_NT'">$(BuildArguments) msbuildonunsupportedplatform</BuildArguments>
+    <BuildArguments Condition="'$(UseSystemLibraries)' == 'true'">$(BuildArguments) cmakeargs -DCLR_CMAKE_USE_SYSTEM_LIBUNWIND=TRUE</BuildArguments>
     <BuildArguments Condition="$(Platform.Contains('arm'))">$(BuildArguments) skipnuget cross -skiprestore cmakeargs -DFEATURE_GDBJIT=TRUE</BuildArguments>
     <BuildCommand>$(ProjectDirectory)/build$(ShellExtension) $(BuildArguments) --</BuildCommand>
     <BuildCommand Condition="$(Platform.Contains('arm'))">$(ArmEnvironmentVariables) $(BuildCommand)</BuildCommand>