Am 05.06.2017 um 20:49 schrieb Jonas Maebe: > On 05/06/17 20:37, Denis Kozlov wrote: >> >> >> On 05/06/2017 18:59, Jonas Maebe wrote: >>> That is why I said "If range checking is off there or disabled via an >>> explicit type cast, then >>> the result is undefined by definition." You use an explicit typecast above. >> >> I just wanted to highlight that these cases as legal and I presume not >> uncommon, particularly if values are deserialized and typecasted. > > Then this de-serialisation code must perform range checking. Again: if you > assign an invalid value > to a variable by typecasting, disabling range checking, inline assembly, > passing a pointer to C code > and overwriting the value there, or in any other way, Pascal code that works > with the resulting > value has undefined behaviour. The program could crash, silently fail, raise > a random exception at > some point, or do anything else. >
For the record: this can already happen. If a jump table for a case statement is generated, the compiler does not check the boundaries if the jump table covers the whole declared (!) range of the case variable. _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
