On Thu, Feb 27, 2014 at 07:48:35AM -0800, H. Peter Anvin wrote: > > Do we have a fairly comprehensive list of what these extrastandard > > requirements / assumptions are? It might be a good idea to have one > > that we can point to, so that (a) people who are trying to define a > > new architecture knows what they need to handle, (b) and so we can > > give a list of things that static code analyzers like smatch and > > coverity and sparse should be able to suppress (perhaps in a Linux > > kernel-only mode). > > > > No, but I think we can certainly make a list... a lot of it right now > sits in various people's heads. > > Here are a couple: > > - Bytes are 8 bits > - Signed integers will be 2's complement > - sizeof char, short, int, long, and long long will be 1, 2, 4, 4, 8 or > 1, 2, 4, 8, 8 on 32- and 64-bit processors, respectively. > - sizeof(long) == sizeof(void *) > - NULL is represented by all zero > - Structures will not add padding as long as all the members are > naturally aligned. > That last assumption has to change for the Meta architecture. https://lwn.net/Articles/522188/ On meta, the structs and unions are padded to 4 bytes unless they are explicitly marked as __packed. regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
