On 03/11/2013 06:07 PM, David Chisnall wrote:
As I recall, on OS X the isa pointer for bridged types contains the
typeid. The Objective-C runtime has some extra logic that checks if
the isa pointer is <= 0xffff and, if so, looks up the class from a
table. The open source CFLite stuff doesn't have this.
David
They actually use this:
#pragma pack(1)
struct apple_cfstring
{
void* isa;
uint8_t flags;
uint8_t typeID;
uint8_t unused[2];
#ifdef __x86_64__
uint32_t extraFlags;
#endif
void* data;
unsigned long length;
};
#pragma pack()
So isa is kept separately from typeID.
--
Luboš Doležel
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