On Tue, Oct 22, 2013 at 8:43 AM, ken han <j609444@xxxxxxxxx> wrote: > > I used macports to update gcc to version 4.8.1. I would like to use > that version to build libusbx 1.0.17. But when I './configure' and > then 'make' libusbx I get "error: too many #pragma options > align=reset" (see error bellow), and it fails to build. If I configure > libusbx with 'CC=clang ./configure' and then 'make' it works fine but > that is building with gcc 4.2, and that is not what I want. Is there > any way to build libusbx with gcc 4.8 on mac? > > Reading through gcc docs > (http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html) it seems that gcc > understands both "#pragma pack(1)" and "#pragma options align=reset," > so I am not sure why I am getting this error. It seems to be related > to this bug - http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50909, but I > am not sure since this is an old bug and gcc 4.2 that comes with mac > works. I am looking for a way to edit the header file, I do not want > to patch and rebuild gcc. Thanks for any suggestions. > > In USB.h file the pragma's are in this form. > > #pragma pack(1) > ... struct .... > #pragma options align=reset The current GCC implementation expects align=reset to follow some other options align=XXX. It sounds like USB.h expects options align=reset to undo a pack(1). I assume that the GCC implementation ought to be extended for this; consider opening a bug report. For GCC, to undo pack(1), you can just use pack(). So it sounds like you could compile your library by changing the "#pragma options align=reset" to "#pragma pack()". Ian
