On Mon, Dec 29, 2008 at 09:00:36AM -0000, John Emmas wrote: >On Mon, Dec 24, 2008 at 19:47 Ralph Hempel wrote: >>John, if I understand you correctly, you are running up against a >>classic problem in embedded systems programming. Namely that you >>cannot assume anything about structure packing, byte ordering, or >>alignment when doing RPC or transmitting data across platforms. > >Yesterday I spent some time looking into this but didn't come to any >hard & fast conclusions. Variables themselves seem to correlate very >well between MSVC and Cygwin (even 'long' which I thought was >different). But when calculating structure alignment (manually) >sometimes Cygwin gave closer results to what I expected and sometime >MSVC was closer. > >Before I try Ralph's suggestion I'd like (if possible) to try building >both versions with struct packing disabled. This is fairly simple to >do with Microsoft's compiler (I just set the member alignment to '1 >byte') but can it be done for my Cygwin compiler - e.g. with a >compiler option or a #pragma or whatever?
All of the pragmas should be discussed in the "info gcc" documentation. Just go to the "Pragmas" node or search for "Pragmas Accepted by GCC". -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
