On Mon, 11 Jan 2010, Xavi wrote:
Hi,
> IMHO the next changes in the functions hb_parptrGC and hb_itemGetPtrGC .-
> void * hb_itemGetPtrGC( PHB_ITEM pItem, const HB_GC_FUNCS * pFuncs )
> {
> HB_TRACE(HB_TR_DEBUG, ("hb_itemGetPtrGC(%p,%p)", pItem, pFuncs));
> if( pItem && HB_IS_POINTER( pItem ) && pItem->item.asPointer.collect )
> {
> if( pFuncs )
> return (hb_gcFuncs( pItem->item.asPointer.value ) == pFuncs ?
> pItem->item.asPointer.value : NULL);
> else
> return pItem->item.asPointer.value;
> }
> else
> return NULL;
> }
>
> Allows return generic GCs calling functions with pFuncs parameter to NULL.
The ides of hb_itemGetPtrGC() is to _NOT_ make such things and return
_ONLY_ pointers which are exactly the requested type.
You can use hb_itemGetPtr() to return pointer without any validation.
If you need such function in your own code then you can simply create
it locally, i.e.:
void * hb_itemGetPointer( PHB_ITEM pItem, const HB_GC_FUNCS * pFuncs )
{
if( pFuncs == NULL )
return hb_itemGetPtr( pItem );
else
return hb_itemGetPtrGC( pItem, pFuncs );
}
or you can even create macro:
#define hb_itemGetPointer( itm, fncs ) \
( (fncs) ? hb_itemGetPtrGC( itm, fncs ) : hb_itemGetPtr( itm ) )
> As they are functions of our public API, IMO this facilitates
> development of libraries because may happen that the address of
> function is unknown or static but we are interested in having the GC
> pointer.
Use hb_itemGetPtr(). Please only remember that such code does not
validate pointer item type so should not be committed to SVN as if
it tries to cast return pointer to some other structures.
> For example .-
> One possible implementation in wapi_par_HANDLE because the HANDLE
> can be pointer plane, GC or GC external (address of function is
> unknown, static), could be .-
> HANDLE wapi_par_HANDLE( int iParam )
> {
> void ** ph = ( void ** ) hb_parptrGC( NULL, iParam );
> return (ph ? ( HANDLE ) *ph : ( HANDLE ) hb_parptr( iParam ));
> }
> What do you think about this?. Comments.
You do not have to change anything in core code to create such function.
Using current API you can reach such effect effect by simple:
HANDLE wapi_par_HANDLE( int iParam )
{
void ** ph = ( void ** ) hb_parptr( iParam );
return ( HANDLE ) ( ph ? *ph : NULL );
}
As you can see this code is much simpler.
The only one problem with above is that it does not validate type
of given item so passing wrong pointer item to function using
wapi_par_HANDLE() will probably cause GPF or other bad side effects.
best regards,
Przemek
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