Index: lib/Driver/DarwinLdOptions.td
===================================================================
--- lib/Driver/DarwinLdOptions.td
+++ lib/Driver/DarwinLdOptions.td
@@ -231,6 +231,10 @@
      MetaVarName<"<number>">,
      HelpText<"Maximum number of errors to emit before stopping (0 = no limit)">;
 
+// Ignored options
+def lto_library : Separate<["-"], "lto_library">,
+    MetaVarName<"<path>">,
+    HelpText<"Ignored for compatibility with other linkers">;
 
 // Obsolete options
 def grp_obsolete : OptionGroup<"obsolete">, HelpText<"OBSOLETE OPTIONS">;
Index: test/darwin/cmdline-lto_library.objtxt
===================================================================
--- test/darwin/cmdline-lto_library.objtxt
+++ test/darwin/cmdline-lto_library.objtxt
@@ -0,0 +1,11 @@
+# RUN: ld64.lld -arch x86_64 -lto_library %t -print-atoms -r %s 2>&1 | FileCheck %s
+#
+# Test that the -lto_library option does not result in an error.
+#
+
+# CHECK-NOT: -lto_library
+
+--- !native
+defined-atoms:
+    - name:              _foo
+...