linking XPCOM on OS X

I had a difficult time linking my first XPCOM object on OS X. After searching around and reading various posts I wound up with the following setup for the linker:

 g++ -dynamiclib -o mylibrary.dylib whatever.o -L$(GECKO_SDK)/lib \
 -L$(XULRUNNER) -Wl,-executable_path,$(XULRUNNER) \
 -lxpcomglue_s -lxpcom -lnspr4 -lplc4