Hello Gabor,
Tuesday, April 13, 2004, 4:26:24 PM, you wrote:
GF> 2. Why is the "{ }" needed?
GF> #define __pgd(x) ((pgd_t) { (x) } )
It casts unsigned long/unsigned long long to pgd_t type which models pgdir entry. There is no such
thing in C89/90
standart. Normally a struct isnt casted to other types and vice versa. That is, It is an extension. Linux kernel
exploits gcc's nonstandart properties frequently.
#define __pte(x) ((pte_t) { (x) } )
First of all, a compound statement is used.(Extension) -> { } Then the return value is casted to
desired type. Still a cast from any types to struct types is not standard, which it is used here...
--
Bora Sahin
borasahin.port5.com
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