AppleClang UBSan has a different runtime name (#145)

Author: olupton

cpp/cmake/sanitizers.cmake

@@ -113,7 +113,12 @@ function(cpp_cc_enable_sanitizers)
     endforeach()
     string(JOIN " " compiler_flags_str ${compiler_flags})
     # Figure out where the runtime library lives
-    cpp_cc_find_sanitizer_runtime(NAME ubsan_standalone OUTPUT runtime_library)
+    if(CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
+      set(runtime_library_name ubsan)
+    else()
+      set(runtime_library_name ubsan_standalone)
+    endif()
+    cpp_cc_find_sanitizer_runtime(NAME ${runtime_library_name} OUTPUT runtime_library)
     if(EXISTS "${PROJECT_SOURCE_DIR}/.sanitizers/undefined.supp")
       set(ubsan_opts "suppressions=${PROJECT_SOURCE_DIR}/.sanitizers/undefined.supp:")
     endif()