gp_common.h File Reference

Common macros. More...

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <stddef.h>
#include <core/gp_compiler.h>

Go to the source code of this file.

Macros
#define	GP_MIN(a, b)
	Returns a minimum of the two numbers.
#define	GP_MIN3(a, b, c)
	Returns a minimum of the three numbers.
#define	GP_MAX(a, b)
	Returns a maximum of the two numbers.
#define	GP_MAX3(a, b, c)
	Returns a maximum of the three numbers.
#define	GP_CONCAT2(a, b)   a##b
	A macro to concatenate two strings.
#define	GP_UNIQUE_ID(prefix)   GP_UNIQUE_ID__(prefix, __COUNTER__)
	Generates an unique C identifier with a given prefix.
#define	GP_ABS(a)
	Returns an absolute value.
#define	GP_ABS_DIFF(a, b)
	Computes an absolute value of a difference.
#define	GP_ALIGN2(a)
	Aligns a value to be even.
#define	GP_SWAP(a, b)
	Swaps a and b.
#define	GP_ARRAY_SIZE(array)   (sizeof(array) / sizeof(*array))
	Computes number of elements of a statically defined array size.
#define	GP_CONTAINER_OF(ptr, structure, member)    ((structure *)((char *)(ptr) - offsetof(structure, member)))
	Converts from a pointer to a struct field to a pointer to the struct itself.

Detailed Description

Common macros.

Definition in file gp_common.h.

Macro Definition Documentation

GP_ABS

#define GP_ABS

(

a

)

Value:

        ({ \
        typeof(a) gp_a__ = a; \
        gp_a__ > 0 ? gp_a__ : - gp_a__; \
})

Returns an absolute value.

Parameters

a

A number.

Returns

An absolute value of a.

Definition at line 110 of file gp_common.h.

GP_ABS_DIFF

#define GP_ABS_DIFF	(		a,
			b
	)

Value:

        ({ \
        typeof(a) gp_a__ = a; \
        typeof(b) gp_b__ = b; \
        gp_a__ > gp_b__ ? gp_a__ - gp_b__ : gp_b__ - gp_a__; \
})

Computes an absolute value of a difference.

Parameters

a	A number.
b	A number.

Returns

An absolute value of a difference between a and b.

Definition at line 123 of file gp_common.h.

GP_ALIGN2

#define GP_ALIGN2

(

a

)

Value:

        ({ \
        typeof(a) gp_a__ = a; \
        gp_a__ + (gp_a__%2); \
})

Aligns a value to be even.

Parameters

a	An integer number.

Returns

A value aligned to be divisible by two.

Definition at line 135 of file gp_common.h.

GP_ARRAY_SIZE

#define GP_ARRAY_SIZE

(

array

)

(sizeof(array) / sizeof(*array))

Computes number of elements of a statically defined array size.

Parameters

array

An array.

Returns

A number of array elements.

Definition at line 168 of file gp_common.h.

GP_CONCAT2

#define GP_CONCAT2	(		a,
			b
	)		a##b

A macro to concatenate two strings.

Parameters

a	A string constant.
b	A string constant.

Returns

A concatenated string.

Definition at line 88 of file gp_common.h.

GP_CONTAINER_OF

#define GP_CONTAINER_OF	(		ptr,
			structure,
			member
	)		((structure *)((char *)(ptr) - offsetof(structure, member)))

Converts from a pointer to a struct field to a pointer to the struct itself.

The inverse functions is part of the C language and is called offsetof().

Parameters

ptr	A pointer to a structure member.
structure	A structure C type e.g. struct foo.
member	A structure member name.

Definition at line 180 of file gp_common.h.

GP_MAX

#define GP_MAX	(		a,
			b
	)

Value:

        ({ \
        typeof(a) gp_a__ = (a); \
        typeof(b) gp_b__ = (b); \
        gp_a__ > gp_b__ ? gp_a__ : gp_b__; \
})

Returns a maximum of the two numbers.

Parameters

a	A number.
b	A number.

Returns

A maximum of a and b.

Definition at line 59 of file gp_common.h.

GP_MAX3

#define GP_MAX3	(		a,
			b,
			c
	)

Value:

        ({ \
        typeof(a) gp_a__ = (a); \
        typeof(b) gp_b__ = (b); \
        typeof(c) gp_c__ = (c); \
        gp_a__ > gp_b__ ? (gp_a__ > gp_c__ ? gp_a__ : gp_c__) : (gp_b__ > gp_c__ ? gp_b__ : gp_c__); \
})

Returns a maximum of the three numbers.

Parameters

a	A number.
b	A number.
c	A number.

Returns

A maximum of a, b and c.

Definition at line 73 of file gp_common.h.

GP_MIN

#define GP_MIN	(		a,
			b
	)

Value:

        ({ \
        typeof(a) gp_a__ = (a); \
        typeof(b) gp_b__ = (b); \
        gp_a__ < gp_b__ ? gp_a__ : gp_b__; \
})

Returns a minimum of the two numbers.

Parameters

a	A number.
b	A number.

Returns

A minimum of a and b.

Definition at line 31 of file gp_common.h.

GP_MIN3

#define GP_MIN3	(		a,
			b,
			c
	)

Value:

        ({ \
        typeof(a) gp_a__ = (a); \
        typeof(b) gp_b__ = (b); \
        typeof(c) gp_c__ = (c); \
        gp_a__ < gp_b__ ? (gp_a__ < gp_c__ ? gp_a__ : gp_c__) : (gp_b__ < gp_c__ ? gp_b__ : gp_c__); \
})

Returns a minimum of the three numbers.

Parameters

a	A number.
b	A number.
c	A number.

Returns

A minimum of a, b and c.

Definition at line 45 of file gp_common.h.

GP_SWAP

#define GP_SWAP	(		a,
			b
	)

Value:

        do { \
        typeof(b) gp_b__ = b; \
        b = a; \
        a = gp_b__; \
} while (0)

Swaps a and b.

Attention

Modifies the variables passed as parameters.

Parameters

a	A value to be swapped.
b	A value to be swapped.

Definition at line 148 of file gp_common.h.

GP_UNIQUE_ID

#define GP_UNIQUE_ID

(

prefix

)

GP_UNIQUE_ID__(prefix, __COUNTER__)

Generates an unique C identifier with a given prefix.

This is intended to be used to generate an unique indentifier for functions or structures generated by macros.

Parameters

prefix

A prefix for the unique ID.

Returns

An unique C identifier with a given prefix.

Definition at line 102 of file gp_common.h.