* Jonathan Wakely:
> On Tue, 20 May 2025 at 10:59, Alexander Monakov via Gcc-help
> <gcc-help@xxxxxxxxxxx> wrote:
>>
>>
>> On Tue, 20 May 2025, Florian Weimer via Gcc-help wrote:
>>
>> > Is there a concise way to convert X to a value Y of type int, so that
>> >
>> > X == (unsigned int) Y
>> >
>> > (assuming that X is of type unsigned int to start with)? GCC supports
>> > this as an extension, using Y = (int) X, but this extension is
>> > apparently unavailable if UBSAN is active.
>>
>> Can you give a specific compilable example? Neither GCC nor Clang instruments
>>
>> int f(unsigned x)
>> {
>> return x;
>> }
>>
>> under -fsanitize=undefined.
>
> Clang has -fsanitize=integer though:
>
> int.cc:3:10: runtime error: implicit conversion from type 'unsigned
> int' of value 2147483648 (32-bit, unsigned) to type 'int
> ' changed the value to -2147483648 (32-bit, signed)
> SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior int.cc:3:10
>
> GCC does not (and will not) implement that.
Ahh, so it's not UBSAN but integer sanitizer. I think this could be
clarified in the manual (that this is an extension supported by UBSAN as
well).
Thanks,
Florian
