On Dec 7 2006 21:17, Josef Sipek wrote:
>> >> > >+void __unionfs_mknod(void *data)
>> >> > >+{
>> >> > >+ struct sioq_args *args = data;
>> >> > >+ struct mknod_args *m = &args->mknod;
...
||||| vfs_mknod(m->parent, m->dentry, m->mode, m->dev);
>> >If I make the *args = data line const, then gcc (4.1) yells about modifying
>> >a const variable 3 lines down..
>> >
>> >args->err = vfs_mknod(m->parent, m->dentry, m->mode, m->dev);
>> >
>> >Sure, I could cast, but that seems like adding cruft for no good reason.
>>
>> No I despise casts more than missing consts. Why would gcc throw a warning?
>> Let's take this super simple program
>
>No, this program doesn't tickle the problem.. Try to compile this one:
The members of m (i.e. m->*) are not modified as for as __unionfs_mknod goes.
vfs_mknod may only modify the members of m->parent (i.e. m->parent->*)
>
><<<
>struct mknod_args {
> int mode;
> int dev;
>};
>
>void __mknod(const void *data)
>{
> const struct mknod_args *args = data;
> args->mode = 0;
>}
>
>int main(void) {
> const struct mknod_args *m;
> __mknod(m);
> return 0;
>}
>>>>
>
>$ gcc -Wall -c test.c
>test.c: In function âmknodâtest.c:10: error: assignment of read-only location
>
>
>Josef "Jeff" Sipek.
>
>--
>Reality is merely an illusion, albeit a very persistent one.
> - Albert Einstein
>
-`J'
--
