[Bug c++/60664] New: bool / out of range int comparison warning failure

[dcb314 at hotmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60664

            Bug ID: 60664
           Summary: bool / out of range int comparison warning failure
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com

Consider the following code:

extern bool f(int n);

void
g(int a, int b)
{
    if (f(a) == 2)
        f(b);
}

gcc says nothing

$ g++ -c -O2 -Wall -Wextra -ansi -pedantic mar26b.cc

clang has more to say
$ clang++ -c !$
clang++ -c mar26b.cc
mar26b.cc:7:11: warning: comparison of constant 2 with expression of type
'bool'
      is always false [-Wtautological-constant-out-of-range-compare]
        if (f(a) == 2)
            ~~~~ ^  ~
1 warning generated.

I've just built gcc trunk with clang and it looks as if producing
a similar warning to clang will flush out five bugs in gcc trunk.