blob: cd42c4942dad4ee63a3a2be857cccdbbca29f78f [file] [log] [blame]
/*
* Copyright (c) 2020 Endian Technologies AB
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_INCLUDE_NET_LWM2M_PATH_H_
#define ZEPHYR_INCLUDE_NET_LWM2M_PATH_H_
/**
* @brief LwM2M path helper macros
* @defgroup lwm2m_path_helpers LwM2M path helper macros
* @ingroup lwm2m_api
* @{
*/
/**
* @brief Generate LwM2M string paths using numeric components.
*
* Accepts at least one and up to four arguments. Each argument will be
* stringified by the pre-processor, so calling this with non-literals will
* likely not do what you want.
*
* For example:
*
* @code{c}
* #define MY_OBJ_ID 3
* LWM2M_PATH(MY_OBJ_ID, 0, 1)
* @endcode
*
* would evaluate to "3/0/1", while
*
* @code{c}
* int x = 3;
* LWM2M_PATH(x, 0, 1)
* @endcode
*
* evaluates to "x/0/1".
*/
#define LWM2M_PATH(...) \
LWM2M_PATH_MACRO(__VA_ARGS__, LWM2M_PATH4, LWM2M_PATH3, \
LWM2M_PATH2, LWM2M_PATH1)(__VA_ARGS__)
/** @cond INTERNAL_HIDDEN */
/* Internal helper macros for the LWM2M_PATH macro */
#define LWM2M_PATH_VA_NUM_ARGS(...) \
LWM2M_PATH_VA_NUM_ARGS_IMPL(__VA_ARGS__, 5, 4, 3, 2, 1)
#define LWM2M_PATH_VA_NUM_ARGS_IMPL(_1, _2, _3, _4, N, ...) N
#define LWM2M_PATH1(_x) #_x
#define LWM2M_PATH2(_x, _y) #_x "/" #_y
#define LWM2M_PATH3(_x, _y, _z) #_x "/" #_y "/" #_z
#define LWM2M_PATH4(_a, _x, _y, _z) #_a "/" #_x "/" #_y "/" #_z
#define LWM2M_PATH_MACRO(_1, _2, _3, _4, NAME, ...) NAME
/** @endcond */
/**
* @brief Initialize LwM2M object structure
*
* Accepts at least one and up to four arguments. Fill up @ref lwm2m_obj_path structure
* and sets the level.
*
* For example:
*
* @code{c}
* struct lwm2m_obj_path p = LWM2M_OBJ(MY_OBJ, 0, RESOURCE);
* @endcode
*
* Can also be used in place of function argument to return the structure allocated from stack
*
* @code{c}
* lwm2m_notify_observer_path(&LWM2M_OBJ(MY_OBJ, inst_id, RESOURCE));
* @endcode
*
*/
#define LWM2M_OBJ(...) \
GET_OBJ_MACRO(__VA_ARGS__, LWM2M_OBJ4, LWM2M_OBJ3, LWM2M_OBJ2, LWM2M_OBJ1)(__VA_ARGS__)
/** @cond INTERNAL_HIDDEN */
/* Internal helper macros for the LWM2M_OBJ macro */
#define GET_OBJ_MACRO(_1, _2, _3, _4, NAME, ...) NAME
#define LWM2M_OBJ1(oi) (struct lwm2m_obj_path) {.obj_id = oi, .level = 1}
#define LWM2M_OBJ2(oi, oii) (struct lwm2m_obj_path) {.obj_id = oi, .obj_inst_id = oii, .level = 2}
#define LWM2M_OBJ3(oi, oii, ri) (struct lwm2m_obj_path) \
{.obj_id = oi, .obj_inst_id = oii, .res_id = ri, .level = 3}
#define LWM2M_OBJ4(oi, oii, ri, rii) (struct lwm2m_obj_path) \
{.obj_id = oi, .obj_inst_id = oii, .res_id = ri, .res_inst_id = rii, .level = 4}
/** @endcond */
/** @} */
#endif /* ZEPHYR_INCLUDE_NET_LWM2M_PATH_H_ */