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Re: New gcc 4.0.0 warnings seem spurious
Vincent Lefevre writes:
> On 2005-04-26 13:15:43 -0700, Zack Weinberg wrote:
> > The initializer thus tries to give a variable with type unsigned:8
> > a value that it cannot hold. The diagnostic is correct.
> However it is correct to store any integer to an unsigned variable,
> even if the original value cannot be represented.
It's legal. That's why we compile it and don't issue an error.
> Therefore the diagnostic isn't necessary,
Warnings are to help the programmer see where there is some code that,
although not necessarily an error, may require some attention. This
is a classic case of such a warning. This warning really does
indicate to the programmer that there might be a real problem.
> and IMHO, there should be a way to disable it (possibly locally to
> some part of the program).
Why not just fix the code?
> > Bruce Lilly <firstname.lastname@example.org> writes:
> > > static const unsigned char AAA = 0x1U;
> > > static const unsigned char BBB = 0x2U;
> > Again, C does not work the way you think. These are not constants.
> But if they are never modified, they evaluate to constants, right?
> The fact that they are not considered as constant expressions,
> is it due to the fact that the environment is allowed to modify
It's due to what the C standard says. A const variable in C isn't a
constant, it's just a read-only variable.