On Freitag, 22. März 2019 11:02:39 CET Andrew Haley wrote: > On 3/21/19 10:19 PM, Allan Sandfeld Jensen wrote: > > From having fixed UBSAN warnings, I have seen many cases where undefined > > behavior was performed, but where the code was aware of it and the final > > result of the expression was well defined nonetheless. > > Is this belief about undefined behaviour commonplace among C programmers? > There's nothing in the standard to justify it: any expression which contains > UB is undefined.
Yes, even GCC uses undefined behavior when it is considered defined for specific architecture, whether it be the result of unaligned access, negative shifts, etc. There is a lot of the warnings that UBSAN warns about that you will find both in GCC itself, the Linux kernel and many other places. 'Allan
