[Bug c/82728] New: Incorrect -Wunused-but-set-variable warning with a const

[sylvestre at debian dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82728

            Bug ID: 82728
           Summary: Incorrect -Wunused-but-set-variable warning with a
                    const
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: sylvestre at debian dot org
  Target Milestone: ---

with:

void foo(void) {
  const int ID = 1;
  switch (0) {
  case ID:
    break;
  }
}

# gcc-7 -Wall -c foo.cpp 
# gcc-8 -Wall -c foo.cpp 
foo.cpp: In function 'void foo()':
foo.cpp:2:13: warning: variable 'ID' set but not used
[-Wunused-but-set-variable]
   const int ID = 1;
             ^~