Miscellaneous

Small generic macros. More...

Macros
#define	container_of(ptr, type, member)   ((type *)((char *)(ptr) - (size_t)&(((type *)0)->member)))
	Get the structure that contains a member.
#define	PBL_SWAP(a, b)
	Swap the values of two lvalues of the same type.
#define	PBL_FOURCC(a, b, c, d)
	Pack four characters into a uint32_t, the first one in the most significant byte.

Detailed Description

Small generic macros.

Macro Definition Documentation

container_of

#define container_of	(		ptr,
			type,
			member
	)		((type *)((char *)(ptr) - (size_t)&(((type *)0)->member)))

Get the structure that contains a member.

Parameters

ptr	Pointer to the member.
type	Type of the containing structure.
member	Name of the member within type.

Returns

Pointer to the containing structure.

PBL_FOURCC

#define PBL_FOURCC	(		a,
			b,
			c,
			d
	)

Value:

  ((uint32_t)(((uint32_t)(uint8_t)(a) << 24) | ((uint32_t)(uint8_t)(b) << 16) | \
              ((uint32_t)(uint8_t)(c) << 8) | (uint32_t)(uint8_t)(d)))

Pack four characters into a uint32_t, the first one in the most significant byte.

Parameters

a	First character.
b	Second character.
c	Third character.
d	Fourth character.

PBL_SWAP

#define PBL_SWAP	(		a,
			b
	)

Value:

  do {                                 \
    __typeof__(a) _pbl_swap_tmp = (a); \
    (a) = (b);                         \
    (b) = _pbl_swap_tmp;               \
  } while (0)

Swap the values of two lvalues of the same type.

Parameters

a	First lvalue, evaluated more than once.
b	Second lvalue, evaluated more than once.