[Bug c/117981] New: -Wc11-c23-compat does not warn for bool, false and true

[vincent-gcc at vinc17 dot net via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117981

            Bug ID: 117981
           Summary: -Wc11-c23-compat does not warn for bool, false and
                    true
           Product: gcc
           Version: 14.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vincent-gcc at vinc17 dot net
  Target Milestone: ---

Consider

int f (void)
{
  int bool = 3;
  int false = 4;
  int true = 5;
  return bool + false + true;
}

Compiling with "-Wc11-c23-compat -c" does not emit any warning.

This can be reproduced with

gcc-14 (Debian 14.2.0-8) 14.2.0

and

gcc (Debian 20241123-1) 15.0.0 20241123 (experimental) [master
r15-5606-g4aa4162e365]

but for the latter, one needs "-std=c11 -Wc11-c23-compat -c" to test the
-Wc11-c23-compat feature. Otherwise, one gets an error, whether
-Wc11-c23-compat is used or not, because this version compiles in C23 mode by
default.