Wish: more checks and

[Olivier L'Heureux]

Hello!

While Splint is certainly a great tool, I was wondering
if it could catch more errors.

As shown by the following program, Splint doesn't seem
to catch a negative index in an array. (On line 11)
It generates however a spurious warning on line 12,
where it could perhaps infer that "n" is not negative.

|>  1   #include <assert.h>
|>  2   #include <stdio.h>
|>  3   
|>  4   int main( void )
|>  5   {
|>  6     unsigned int a[3] = { 17, 19, 23 };
|>  7     const int n = 2;
|>  8   
|>  9     if( n>=0 ) {
|> 10       assert( n>=0 );
|> 11       printf( "a[-2]  = %u\n", a[-2] );
|> 12       printf( "result = %d\n", 19 >> n );
|> 13     }
|> 14   
|> 15     return 0;
|> 16   }

#> [olheureu@WKS13 gnss 339] $ splint +boundswrite +boundsread ../tst5.c
#> Splint 3.0.1.6 --- 27 Mar 2002
#>
#> tst5.c: (in function main)
#> tst5.c:12:36: Right operand of >> may be negative (int): 19 >> n
#>   The right operand to a shift operator may be negative (behavior undefined).
#>   (Use -shiftnegative to inhibit warning)
#>
#> Finished checking --- 1 code warning

Do somebody has a clue to let Splint report the first
warning, and not the second?

                                Regards,

                                Olivier L'Heureux
--
Olivier L'Heureux
Septentrio NV, Belgium