bug578.cpp

1    #include <stdio.h>
2    #define Knots
3    const double standard_rating = 10.0 Knots;
4    double rating;
5    void rate_the_ship( double, double, int, double );
6    int main()
7        {
8        rate_the_ship( 64.0, 45.3, 3, standard_rating );
9        printf( "%g\n", rating );
10       return 0;
11       }
12   void rate_the_ship( double LWL, double sailarea,
13                       int nsails, double rating )
14       {
15       rating *= (3.2/LWL) * sailarea * .025 * nsails;
16       return;
17       }

For the big Labor Day (mixed boat) regatta, Mike, a better sailor than programmer, wanted to apply the latest yacht racing formulae for the competing ships. But something is going wrong with this test program. What is it?

bug578.cpp lint Output

--- Module:   bug578.cpp (C++)
    _
    {
bug578.cpp(14) : Warning 578: Declaration of symbol 'rating' hides symbol 'rating' (line 4)
    _
    }
bug578.cpp(17) : Warning 550: Symbol 'rating' (line 13) not accessed

Reference Manual Explanation

578    Declaration of symbol 'Symbol' hides symbol 'Symbol' (Location) -- A local symbol
       has the identical name as a global symbol (or possibly another local symbol).
       This could be dangerous.  Was this deliberate?  It is usually best to rename
       the local symbol.