Re: Generic warning

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Tue, 17 Jun 2008 18:33:42 +0000, S�bastien Morand wrote:

>> Maybe it is just a compiler bug. But you should post a complete compilable
>> code.

No, it is not. The compiler is correct.

> Here is a complete code with the same warning:
> 
> procedure Main is
> 
>    generic
>       --  Element to be stored in the btree
>       type Element (<>) is private;
>       Order: Positive;
>    package TestGen is
>       type ElementPtr is access all Element;
>       Buffer: array(1 .. Order*2) of ElementPtr;
>       procedure Store(E: in Element; index: in Positive);
>    end TestGen;
> 
>    package body TestGen is
>       procedure Store(E: in Element; index: in Positive) is
>       begin
>          --  In my real procedure, index is calculated and there is some
>          --  check. Index can't be > Order*2
>          for i in Positive range Order+2 .. index-1 loop
                                         
The problem is here. You instantiate TestGen with Order = 1. So the upper
bound of Buffer is 2. Therefore the range is 1+2..Index, which should cause
Constraint_Error in Buffer(I).

Bravo GNAT! (Though the warning message could be better)

>             Buffer(i) := new Element'(E);
>          end loop;
>       end Store;
>    end TestGen;
>    package IntTestGen is new TestGen(
>       Element => Integer,
>       Order => 1
>    );
>    use IntTestGen;
> begin
>    Store(1, 4);
> end Main;

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de