[Bug c/77490] New: bit-not (~) on boolean should be warned about

[bernd.edlinger at hotmail dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77490

            Bug ID: 77490
           Summary: bit-not (~) on boolean should be warned about
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: bernd.edlinger at hotmail dot de
  Target Milestone: ---

see: https://gcc.gnu.org/ml/gcc-patches/2016-09/msg00202.html

The problem is that ~ on bool maps [0:1] to [-1:-2]
and thus the result is no longer boolean.  But probably the assignment
normalizes the result again: b = ~b; has the effect of setting b = 1.

this affects c and c++.