Date: Fri, 8 Jun 2001 09:01:29 -0400 (EDT) From: Thomas David Rivers <rivers@dignus.com> To: rivers@dignus.com, roam@orbitel.bg Cc: hackers@FreeBSD.ORG, jhb@FreeBSD.ORG Subject: Re: free() and const warnings Message-ID: <200106081301.JAA50018@lakes.dignus.com> In-Reply-To: <20010608155527.D7671@ringworld.oblivion.bg>
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>
> On Fri, Jun 08, 2001 at 08:51:54AM -0400, Thomas David Rivers wrote:
> > >
> > > GCC complains when I try to initialize the structure with something like:
> > >
> > > struct validation_fun val_init[] = {
> > > {"init", valfun_init, 0}
> > > };
> > >
> > > This can be avoided by:
> > >
> > > struct validation_fun val_init[] = {
> > > {(char *) (uintptr_t) "init", valfun_init, 0}
> > > };
> > >
> > > ..but as a matter of fact, static, pre-initialized valfun structs are
> > > the rule rather than the exception in this program, so having this
> > > syntax for all of them seems.. well.. ugly :)
> > >
> >
> > Ah.. I see..
> >
> > (I don't think you need (uintptr_t) - you can cast a (const char *)
> > to a (char *) without having to go "through" that - I believe.)
>
> Errrr.. this was the whole point of this thread. I *can't* cast
> a (const char *) to a (char *) when using the -Wcast-qual gcc flag -
> the -Wcast-qual flag produces exactly this type of warnings, to make
> sure you don't treat const * pointers as normal pointers, and pass them
> to functions that do stupid things like modify them or free them :)
Yes - I see now... sorry for being slow on the "uptake" :-)
>
> > Is this C, or C++.. there are some differences in the type of
> > a constant character string between the two...
> >
> > But - basically, what you are trying to describe is a field which
> > is sometimes 'const' and othertimes isn't... which doesn't make
> > sense in the context of the C standard... you'll need a cast
> > for the initialization, or some other approach besides static
> > initialization I believe... (or, just "live" with the warning...
> > which isn't pleasant at all.)
>
> Well, I can't live with the warning with -Werror ;) So I guess I'll
> live with casting in free() :)
It's not pretty either way... is it?
- Dave R. -
--
rivers@dignus.com Work: (919) 676-0847
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