Re: BUG #5416: int4inc() is wrong

Hi Tom,

> If you can show me rewrites of all the basic arithmetic operations that
> detect overflow in full compliance with the C standard, and are
> readable, portable, and efficient, I'm all ears.

These are the best ones that I know of:


https://www.securecoding.cert.org/confluence/display/seccode/INT32-C.+Ensure+that+operations+on+signed+integers+do+not+result+in+overflow

Even if you dislike these, please take a look at the safety checks for
shifts.  The current postgresql shift functions need to be strengthened,
and it is easy to do.

John Regehr