my $parser= qr{
        \G                  # Don't skip anything
        (?:
          [^'"/]+           # Stuff we don't care about
        | '(?:[^\\']+|\\.)' # '"', '\'', '\\', 'param'
        | /\* .*? \*/       # A C comment
        | //[^\n]+          # A C++ comment
        | /                 # /, not a comment, division
        | "((?:[^\\"]+|\\.)*)"  # A quoted string ($1)
        | (.)               # An error ($2)
        )
    }xs;

    my $code= do { local($/); <CCODE> };
    my @strings;
    while(  $code =~ m/$parser/g  ) {
        if(  defined $1  ) {
            push @strings, $1;
        } elsif(  defined $2  ) {
            my $char= $2;
            my $pos= pos($code)-5;
            $pos= 0   if  $pos < 0;
            my $context= substr( $code, $pos, 10 );
            warn "Ignoring unexpected character ($char) in ($context)";
        }
    }