Re: Clang UndefinedBehaviorSanitize (Postgres14) Detected undefined-behavior - Mailing list pgsql-hackers

On 2020-Aug-31, Ranier Vilela wrote:

> More troubles with undefined-behavior.
> 
> This type of code can leaves overflow:
> var = (cast) (expression);
> diff = (int32) (id1 - id2);
> 
> See:
>     diff64 =  ((long int) d1 - (long int) d2);
>     diff64=-4294901760

Did you compile this with gcc -fwrapv?

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services