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Re: Re[2]: Why "'X' used but never defined" is a warning and not error in gcc?
On Mon, 2012-10-08 at 14:32 +0400, Ilya Basin wrote:
> OE> On Mon, 2012-10-08 at 14:19 +0400, Ilya Basin wrote:
> >> test.c:
> >> static void foo();
> >>
> >> void bar() {
> >> foo();
> >> }
> >>
> >> $ gcc -c test.c
> >> test.c:1: warning: 'foo' used but never defined
> >>
> >> Why warning and not error? Another *.o can refer this static function?
> >>
>
> OE> No, another .o can't refer to this static function. Static functions
> OE> are visible only in the translation unit where they are defined.
>
> OE> The code above will generate a symbol reference to 'foo', i.e. a
> OE> function call to a non-static function. If it is defined in some
> OE> other .o and linked together, the 'foo' from the other .o will be used.
>
> OE> Cheers,
> OE> Oleg
>
>
> Is there a flag to turn this warning into an error?
Doesn't look so. You can turn all warnings into errors by -Werror, but
there's no option to control this particular warning individually.
> Is there a common
> way to find the warning flag from a message?
grep ;)
Cheers,
Oleg