Index: docs/code-signing.txt
===================================================================
--- docs/code-signing.txt
+++ docs/code-signing.txt
@@ -1,6 +1,11 @@
-On MacOSX lldb needs to be code signed. The Debug, DebugClang and Release 
-builds  are set to code sign using a code signing certificate named 
-"lldb_codesign". 
+To use the in-tree debug server on macOS, lldb needs to be code signed. The
+Debug, DebugClang and Release builds are set to code sign using a code signing
+certificate named "lldb_codesign". This document explains how to set up the
+signing certificate.
+
+Note that it is possible build and use lldb on macOS without setting up code
+signing by using the system's debug server. To configure lldb in this way with
+cmake, specify -DLLDB_CODESIGN_IDENTITY=''.
 
 If you have re-installed a new OS, please delete all old lldb_codesign items
 from your keychain. There will be a code signing certification and a public
Index: test/CMakeLists.txt
===================================================================
--- test/CMakeLists.txt
+++ test/CMakeLists.txt
@@ -25,7 +25,9 @@
 endif()
   
 if(TARGET debugserver)
-  list(APPEND LLDB_TEST_DEPS debugserver)
+  if(NOT CMAKE_HOST_APPLE OR LLDB_CODESIGN_IDENTITY)
+    list(APPEND LLDB_TEST_DEPS debugserver)
+  endif()
 endif()
 
 if(TARGET lldb-mi)
@@ -95,7 +97,17 @@
 endif()
 
 if(CMAKE_HOST_APPLE)
-  list(APPEND LLDB_TEST_COMMON_ARGS --server $<TARGET_FILE:debugserver>)
+  if(LLDB_CODESIGN_IDENTITY)
+    list(APPEND LLDB_TEST_COMMON_ARGS --server $<TARGET_FILE:debugserver>)
+  else()
+    execute_process(
+      COMMAND xcode-select -p
+      OUTPUT_VARIABLE XCODE_DEV_DIR)
+    string(STRIP ${XCODE_DEV_DIR} XCODE_DEV_DIR)
+    set(SYSTEM_DEBUGSERVER
+      "${XCODE_DEV_DIR}/../SharedFrameworks/LLDB.framework/Resources/debugserver")
+    list(APPEND LLDB_TEST_COMMON_ARGS --server ${SYSTEM_DEBUGSERVER})
+  endif()
 endif()
 
 set(LLDB_DOTEST_ARGS ${LLDB_TEST_COMMON_ARGS};${LLDB_TEST_USER_ARGS})