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       1            0 : /*
       2              :  * Copyright (c) 2020 Endian Technologies AB
       3              :  *
       4              :  * SPDX-License-Identifier: Apache-2.0
       5              :  */
       6              : 
       7              : #ifndef ZEPHYR_INCLUDE_NET_LWM2M_PATH_H_
       8              : #define ZEPHYR_INCLUDE_NET_LWM2M_PATH_H_
       9              : 
      10              : /**
      11              :  * @file lwm2m.h
      12              :  *
      13              :  * @brief LwM2M path helper macros
      14              :  *
      15              :  * @defgroup lwm2m_path_helpers LwM2M path helper macros
      16              :  * @since 2.5
      17              :  * @version 0.8.0
      18              :  * @ingroup lwm2m_api
      19              :  * @{
      20              :  */
      21              : 
      22              : /**
      23              :  * @brief Generate LwM2M string paths using numeric components.
      24              :  *
      25              :  * Accepts at least one and up to four arguments. Each argument will be
      26              :  * stringified by the pre-processor, so calling this with non-literals will
      27              :  * likely not do what you want.
      28              :  *
      29              :  * For example:
      30              :  *
      31              :  * @code{c}
      32              :  * #define MY_OBJ_ID 3
      33              :  * LWM2M_PATH(MY_OBJ_ID, 0, 1)
      34              :  * @endcode
      35              :  *
      36              :  * would evaluate to "3/0/1", while
      37              :  *
      38              :  * @code{c}
      39              :  * int x = 3;
      40              :  * LWM2M_PATH(x, 0, 1)
      41              :  * @endcode
      42              :  *
      43              :  * evaluates to "x/0/1".
      44              :  */
      45            1 : #define LWM2M_PATH(...) \
      46              :         LWM2M_PATH_MACRO(__VA_ARGS__, LWM2M_PATH4, LWM2M_PATH3, \
      47              :                          LWM2M_PATH2, LWM2M_PATH1)(__VA_ARGS__)
      48              : 
      49              : 
      50              : /** @cond INTERNAL_HIDDEN */
      51              : /* Internal helper macros for the LWM2M_PATH macro */
      52              : #define LWM2M_PATH_VA_NUM_ARGS(...) \
      53              :         LWM2M_PATH_VA_NUM_ARGS_IMPL(__VA_ARGS__, 5, 4, 3, 2, 1)
      54              : #define LWM2M_PATH_VA_NUM_ARGS_IMPL(_1, _2, _3, _4, N, ...) N
      55              : 
      56              : #define LWM2M_PATH1(_x) #_x
      57              : #define LWM2M_PATH2(_x, _y) #_x "/" #_y
      58              : #define LWM2M_PATH3(_x, _y, _z) #_x "/" #_y "/" #_z
      59              : #define LWM2M_PATH4(_a, _x, _y, _z) #_a "/" #_x "/" #_y "/" #_z
      60              : 
      61              : #define LWM2M_PATH_MACRO(_1, _2, _3, _4, NAME, ...) NAME
      62              : /** @endcond */
      63              : 
      64              : /**
      65              :  * @brief Initialize LwM2M object structure
      66              :  *
      67              :  * Accepts at least one and up to four arguments. Fill up @ref lwm2m_obj_path structure
      68              :  * and sets the level.
      69              :  *
      70              :  * For example:
      71              :  *
      72              :  * @code{c}
      73              :  * struct lwm2m_obj_path p = LWM2M_OBJ(MY_OBJ, 0, RESOURCE);
      74              :  * @endcode
      75              :  *
      76              :  * Can also be used in place of function argument to return the structure allocated from stack
      77              :  *
      78              :  * @code{c}
      79              :  * lwm2m_notify_observer_path(&LWM2M_OBJ(MY_OBJ, inst_id, RESOURCE));
      80              :  * @endcode
      81              :  *
      82              :  */
      83            1 : #define LWM2M_OBJ(...) \
      84              :         GET_OBJ_MACRO(__VA_ARGS__, LWM2M_OBJ4, LWM2M_OBJ3, LWM2M_OBJ2, LWM2M_OBJ1)(__VA_ARGS__)
      85              : 
      86              : /** @cond INTERNAL_HIDDEN */
      87              : /* Internal helper macros for the LWM2M_OBJ macro */
      88              : #define GET_OBJ_MACRO(_1, _2, _3, _4, NAME, ...) NAME
      89              : #define LWM2M_OBJ1(oi) (struct lwm2m_obj_path) {.obj_id = oi, .level = 1}
      90              : #define LWM2M_OBJ2(oi, oii) (struct lwm2m_obj_path) {.obj_id = oi, .obj_inst_id = oii, .level = 2}
      91              : #define LWM2M_OBJ3(oi, oii, ri) (struct lwm2m_obj_path) \
      92              :         {.obj_id = oi, .obj_inst_id = oii, .res_id = ri, .level = 3}
      93              : #define LWM2M_OBJ4(oi, oii, ri, rii) (struct lwm2m_obj_path) \
      94              :         {.obj_id = oi, .obj_inst_id = oii, .res_id = ri, .res_inst_id = rii, .level = 4}
      95              : /** @endcond */
      96              : 
      97              : /** @} */
      98              : 
      99              : #endif /* ZEPHYR_INCLUDE_NET_LWM2M_PATH_H_ */