http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56311
--- Comment #3 from Andreas Schwab <sch...@linux-m68k.org> 2013-02-14 11:05:32 UTC --- See fixincludes/inclhack.def, it looks like this is from hackname = hpux10_stdio_declarations, and select = "^#[ \t]*define _iob[ \t]*__iob" needs to be made more strict so that it doesn't match "#define _iob __iob_func()".