Re: mini-os: C programming

[PUCCETTI Armand <armand.puccetti@cea.fr>]

Keir Fraser a écrit :
> On 15/3/07 13:39, "PUCCETTI Armand" <armand.puccetti@cea.fr> wrote:
>
>   
>> extern char *stack;
>>     
>
> Yes, this one is bogus.
>
>   
>> 2. In file xen-3.0.3/extras/mini-os/gnttab.c:140: the const variable
>> gnttabop_error_msgs
>> is declared as
>>
>> static const char *gnttabop_error_msgs[] = GNTTABOP_error_msgs;
>>
>> shouldn't that instead be declared:
>>
>> static const char * const gnttabop_error_msgs[] = GNTTABOP_error_msgs;
>>     
>
> It doesn't really matter, does it? Personally I hate scattering 'const' all
> over the place.
>
>  -- Keir
>
>
>   
It doesn't cause any crash probably, but according to the semantics that you
wish gnttabop_error_msgs to have, all pointers of this array _should_ be 
constant
(I guess you're not going to change the error messages dynamically)
and not only the strings refered by these pointers. The type of both 
declarations
is given by cdecl:

$ cdecl
char * const gnttabop_error_msgs[] ;
declare gnttabop_error_msgs as array of const pointer to char;

const char * gnttabop_error_msgs[];
declare gnttabop_error_msgs as array of pointer to const char;