------- Comment #7 from howarth at nitro dot med dot uc dot edu 2010-02-13 05:09 ------- The weak_import attribute is described fairly well in this technote....
http://developer.apple.com/mac/library/technotes/tn2002/tn2064.html#SECTION2 -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42854