MacOS.cmake: add linker flags to remove unneeded symbols/objects and dynamically-linked libraries

cmake/BornAgain/MacOS.cmake

@@ -24,13 +24,16 @@ execute_process(COMMAND /usr/sbin/sysctl machdep.cpu.extfeatures OUTPUT_VARIABLE
 if(NOT ${SYSCTL_OUTPUT} MATCHES 64)
     message(FATAL "Found a 32bit system - no longer supported")
 endif()
+# On OS X, the `-dead_strip` flag removes unneeded symbols/object files, and
+# `-dead_strip_dylibs` flag removes unneeded libraries [see `man ld` on OSX]
+set(DEADSTRIP_LFLAGS "-dead_strip -dead_strip_dylibs")
 set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS}")
-string(APPEND CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS " -m64")
-string(APPEND CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS " -m64")
+string(APPEND CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS " -m64 ${DEADSTRIP_LFLAGS}")
+string(APPEND CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS " -m64 ${DEADSTRIP_LFLAGS}")
 string(APPEND CMAKE_CXX_FLAGS " -m64 -I${CMAKE_SOURCE_DIR}/Wrap")
 string(APPEND CMAKE_C_FLAGS " -m64")
-string(APPEND CMAKE_C_LINK_FLAGS " -bind_at_load -m64")
-string(APPEND CMAKE_CXX_LINK_FLAGS " -bind_at_load -m64")
+# string(APPEND CMAKE_C_LINK_FLAGS " -bind_at_load -m64")
+# string(APPEND CMAKE_CXX_LINK_FLAGS " -bind_at_load -m64")
 
 
 if(CMAKE_COMPILER_IS_GNUCXX)