Don't pass -split-dwarf= to the backend unless we're on linux for
now.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175814 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index da23fd5..27d019b 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -2311,7 +2311,9 @@
 
   // -gsplit-dwarf should turn on -g and enable the backend dwarf
   // splitting and extraction.
-  if (Args.hasArg(options::OPT_gsplit_dwarf)) {
+  // FIXME: Currently only works on Linux.
+  if (getToolChain().getTriple().getOS() == llvm::Triple::Linux &&
+      Args.hasArg(options::OPT_gsplit_dwarf)) {
     CmdArgs.push_back("-g");
     CmdArgs.push_back("-backend-option");
     CmdArgs.push_back("-split-dwarf=Enable");
diff --git a/test/Driver/split-debug.c b/test/Driver/split-debug.c
index a3711e4..fb01953 100644
--- a/test/Driver/split-debug.c
+++ b/test/Driver/split-debug.c
@@ -8,3 +8,7 @@
 // CHECK-ACTIONS: objcopy{{.*}}--strip-dwo{{.*}}"split-debug.o"
 
 
+// RUN: %clang -target x86_64-macosx -gsplit-dwarf -c -### %s 2> %t
+// RUN: FileCheck -check-prefix=CHECK-NO-ACTIONS < %t %s
+//
+// CHECK-NO-ACTIONS-NOT: -split-dwarf