From 7178c57c16a13bb796980d59b40dceb26972c319 Mon Sep 17 00:00:00 2001
From: Saleem Abdulrasool <compnerd@compnerd.org>
Date: Thu, 29 Mar 2018 14:08:42 -0700
Subject: [PATCH] build: support lld as the linker

For cross-compiling to Windows, lld is a requirement.  It also can be
used for ELF targets.  Add an option to have lld be used as the linker
to mirror the gold option.
---
 CMakeLists.txt     | 2 ++
 src/CMakeLists.txt | 6 ++++++
 2 files changed, 8 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b0adcb598..71e55b173 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -99,6 +99,8 @@ else()
 endif()
 option(USE_GOLD_LINKER "use the gold linker" ${USE_GOLD_LINKER_DEFAULT})
 
+option(USE_LLD_LINKER "use the lld linker" OFF)
+
 option(ENABLE_THREAD_LOCAL_STORAGE "enable usage of thread local storage via __thread" ON)
 set(DISPATCH_USE_THREAD_LOCAL_STORAGE ${ENABLE_THREAD_LOCAL_STORAGE})
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a7cd89bbd..0286d4fc1 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -211,6 +211,12 @@ if(USE_GOLD_LINKER)
                PROPERTY LINK_FLAGS
                  -fuse-ld=gold)
 endif()
+if(USE_LLD_LINKER)
+  set_property(TARGET dispatch
+               APPEND_STRING
+               PROPERTY LINK_FLAGS
+                 -fuse-ld=lld)
+endif()
 
 # Temporary staging; the various swift projects that depend on libdispatch
 # all expect libdispatch.so to be in src/.libs/libdispatch.so