https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109507
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |INVALID
Status|UNCONFIRMED |RESOLVED
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
-fsanitize=undefined, at runtime gives:
/app/example.cpp:4:7: runtime error: negation of -2147483648 cannot be
represented in type 'int'; cast to an unsigned type to negate this value to
itself
Note the message is slightly wrong but points you to the right reason.
There is an overflow. because ~0x80000000 is 2147483648 and then you add 1 to
it giving you an overflow which is undefined. Note ~a+1 is the same as -a as
both cases will overflow at the same time with 0x80000000 which is why GCC is
providing that error message rather then on dealing with +1 like clang does:
Note clang gives:
/app/example.cpp:4:15: runtime error: signed integer overflow: 2147483647 + 1
cannot be represented in type 'int'
