#! perl

my %const_iv;

sub gl() {
   $_ = <>;

   defined $_ or last file;

   1 while s/\/\*.*?\*\///;
   s/\/\*.*$//; # we don't handle multiline-/* comments, so hack around
   s/\/\/.*$//;
   s/^\s+//;
   s/\s+$//;

   $_
}

file:
while () {
   gl;
   if (/^#define\s+([A-Z_0-9]+)\s+(0x[0-9a-fA-F]+|[0-9\.]+)$/) {
      undef $const_iv{$1};
   } elsif (/^enum\b/) {
      while () {
         gl;
         if (/^([a-zA-Z_0-9]+)\s*(?:,|=|$)/) {
            undef $const_iv{$1};
         } elsif (/^\}/) {
            last;
         }
      }
   }
}

for (sort keys %const_iv) {
   print "const_iv($_)\n";
}