Re: [PATCH] CRED: fix compilation warning in function 'get_cred'

From: Hannes Eder
Date: Fri Nov 21 2008 - 09:54:22 EST


On Thu, Nov 20, 2008 at 11:19 PM, David Howells <dhowells@xxxxxxxxxx> wrote:
> Hannes Eder <hannes@xxxxxxxxxxxxxx> wrote:
>
>> Fix to following warning by introducing a temporary variable:
>>
>> include/linux/cred.h: In function 'get_cred':
>> include/linux/cred.h:187: warning: passing argument 1 of
>> 'get_new_cred' discards qualifiers from pointer target type
>
> Interesting. I believe that's a compiler bug. Explicitly casting away the
> const should avoid this warning.

Strange. I think you are right, looks like a compiler bug. I am using
gcc (GCC) 4.2.4 (Ubuntu 4.2.4-1ubuntu3). Compiling the following code
snippet does not yield a spurious warning:

struct foo {
int a;
};

static inline struct foo *bar(struct foo *foo)
{
foo->a++;
return foo;
}

static inline const struct foo *bar2(const struct foo *foo)
{
return bar((struct foo*)foo);
}

What do you suggest, report this as a gcc bug?

-Hannes
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