On Wed, Aug 19, 2009 at 9:36 AM, Cedric BAIL<cedric.b...@free.fr> wrote:
> On Wed, Aug 19, 2009 at 12:23 PM, Vincent Torri<vto...@univ-evry.fr> wrote:
>> On Wed, 19 Aug 2009, Cedric BAIL wrote:
>>> On Wed, Aug 19, 2009 at 12:04 PM, Vincent Torri<vto...@univ-evry.fr>
>>> wrote:
>>>> On Wed, 19 Aug 2009, Cedric BAIL wrote:
>>>>> On Wed, Aug 19, 2009 at 10:40 AM, Vincent Torri<vto...@univ-evry.fr>
>>>>> wrote:
>>>>>> On Wed, 19 Aug 2009, Vincent Torri wrote:
>>>>>>>
>>>>>>> Hey,
>>>>>>>
>>>>>>> in eina_fixed_bitmap.c, lines 68, 88 and 160, offsets are computed and
>>>>>>> stored in an int. But, if I'm not mistaken, on 64 bits arch, offsets
>>>>>>> are
>>>>>>> 64 bits long.
>>>>>>>
>>>>>>> Shouldn't we store them in long instead of int ?
>>>>>>
>>>>>> and technically speaking, we should cast to char * (it seems that, for
>>>>>> gcc, sizeof(void) == 1)
>>>>>
>>>>> And sizeof(void*) ? :-)
>>>>
>>>> if you have :
>>>>
>>>> type *a = ...
>>>> type *b = ...
>>>>
>>>> a - b is equal to (the address of a - the address of b) / sizeof (type)
>>>>
>>>> and not
>>>>
>>>> (the address of a - the address of b) / sizeof (type *)
>>>
>>> Does your compile handle void* arithmetic or not ? I guess your are
>>> porting to some kind of strange compiler that don't support pointer
>>> arithmetic with void* ? I am right ?
>>
>> it supports of course pointer arithmetic, but i think that you don't
>> understand the problem, or you didn't read carefully what i just wrote
>> above.
>>
>> You MUST know the size of 'type'. gcc is stating that void is a type of size
>> 1, it's a gcc feature that is specific to it. suncc does not state that
>> (size of void is undefined in the standard).
>
> It's not gcc specific other decent compiler support this feature. But
> apparently not suncc, so you can patch if needed.
if i understand correctly, suncc does handle void* arithmetic, as one
unit ("byte") and, similar to cast to char* and as I far as I tested
it's the same thing in GCC as well, try the following code:
#include <stdio.h>
int main(void) {
struct x { char a[4], b[4]; } x = {"abc", "123"};
struct y { int a[4], b[4]; } y = {{1, 2, 3, 4}, {10, 20, 30, 40}};
printf("x: char b - a: %2ld ( 4)\n", (char *)x.b - (char *)x.a);
printf("x: void b - a: %2ld ( ?)\n", (void *)x.b - (void *)x.a);
printf("y: char b - a: %2ld (16)\n", (char *)y.b - (char *)y.a);
printf("y: void b - a: %2ld ( ?)\n", (void *)y.b - (void *)y.a);
printf("y: int b - a: %2ld ( 4)\n", y.b - y.a);
return 0;
}
here all char and void report the same, first "?" is 4, second is 16.
--
Gustavo Sverzut Barbieri
http://profusion.mobi embedded systems
--------------------------------------
MSN: barbi...@gmail.com
Skype: gsbarbieri
Mobile: +55 (19) 9225-2202
------------------------------------------------------------------------------
Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day
trial. Simplify your report design, integration and deployment - and focus on
what you do best, core application coding. Discover what's new with
Crystal Reports now. http://p.sf.net/sfu/bobj-july
_______________________________________________
enlightenment-devel mailing list
enlightenment-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/enlightenment-devel
