Al,
4) gcc is kinda-sorta tolerant to mixing pointers to signed and unsigned, unless you explicitly ask to be strict. However, it's nowhere near as lenient as sparse.
Values wrapping because of signed/unsigned is a common cause of faults. In those contexts where the pointer is eventually dereferenced to obtain a pointer I think sparse should continue to complain. Differences of sign in pointer subtraction may or may not be regarded as harmless. I appreciate that gcc is currently an important compiler. But I know of several compiler groups who would like to be able to build an executable kernel using their compiler. Having sparse complain about constructs that gcc is rather lax about means that those involved in kernel development might fix the underlying problem in their code. Such fixes are good in that they increase the probability that a different compiler will successfully compile the kernel. I think a bit of competition in the kernel compiler market would help keep the gcc people on their toes. -- Derek M. Jones tel: +44 (0) 1252 520 667 Knowledge Software Ltd mailto:derek@xxxxxxxxxxxx Applications Standards Conformance Testing http://www.knosof.co.uk - 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
