Compilation fails due to suspicious modulus value

[treiher]

package Test is

     type A is mod 32;

end Test;

rflx-test.ads:7:18: warning: 2 ** 32 may have been intended here [-gnatw.m]

   compilation of rflx-test.ads failed

  7    type A is mod 32;

-gnatw.m
Activate warnings on suspicious modulus values.

This switch activates warnings for modulus values that seem suspicious. The cases caught are where the size is the same as the modulus (e.g. a modulus of 7 with a size of 7 bits), and modulus values of 32 or 64 with no size clause. The guess in both cases is that 2**x was intended rather than x. In addition expressions of the form 2*x for small x generate a warning (the almost certainly accurate guess being that 2**x was intended). The default is that these warnings are given.

I would suggest to disable that switch. @senier @jklmnn What is your opinion?

[senier]

I would suggest to disable that switch. @senier @jklmnn What is your opinion?

If I interpret the help message correctly, we could also consider to always add a size clause to modular types. OTOH, this heuristics does not seem to be too helpful. I have no strong opinion.

[jklmnn]

We already had this case once in regular code where we decided to use 2 ** 5 instead.

[treiher]

we could also consider to always add a size clause to modular types

Let's try that. This has the advantage that the user does not get this warning for generated code (-gnatw.m is activated by default).