On Fri, Nov 25, 2016 at 1:09 AM, Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx> wrote: > Information about storage is needed for objects but once > you take the address of an object, its storage should be > irrelevant for the resulting pointer. > > Trying to keep the storage into the pointer's modifiers > (while it will be available in the base type anyway) only > create corner cases later. Either way it is going to be very tricky. If you make the pointer does not inherent the object storage modifier, you need to change all the place that assume the pointer will inherent the object storage. Because C mostly deal with pointer, e.g. "a = b;", is actually "*(&a) = *(&b);". Pointer is all over the place. Right now sparse make the pointer inherent the storage is convenient but not precise. Changing the underlining assumption will touch a lot of code. The extremely tricky one is the context and address space store in "struct ctype". It is not a modifier but act like one. Address space should belong to the storage object. But right now address space is propagate to pointer as well. Most of the test is done on pointer level. > An example of the problem it can create is when the pointer > is dereferenced in an inlined function. > > Better to simply not put have the storage informations > for the pointer, which is what this patch does. I think there will be other code changes associate with the assumption change. One thing to verify is if sparse issues different set of warning on the Linux kernel check. Chris -- 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
