http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58270
--- Comment #7 from Mikael Pettersson <mikpe at it dot uu.se> --- Your examples are invalid C. In one module you present the compiler with a specific declaration, and complain when it utilizes constraints derived from that declaration. Then in another module you have an _incompatible_ declaration for the same object. You can't expect to get away with that, even if it seemed to work with an older compiler. You should use a C99 "flexible array member", or a pointer (to an array of unknown size).