On 3/22/19 10:20 AM, Allan Sandfeld Jensen wrote: > 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,
If it's defined for a specific architecture it's not undefined. Any compiler is entitled to do anything with UB, and "anything" includes extending the language to make it well defined. -- Andrew Haley Java Platform Lead Engineer Red Hat UK Ltd. <https://www.redhat.com> EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671
