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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_ */