include/side/macros.h

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  * Copyright 2022 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  */
   5
   6 #ifndef _SIDE_MACROS_H
   7 #define _SIDE_MACROS_H
   8
   9 #include <stddef.h>
  10
  11 /* Helper macros */
  12
  13 #define SIDE_ARRAY_SIZE(arr)    (sizeof(arr) / sizeof((arr)[0]))
  14
  15 /*
  16  * Compound literals with static storage are needed by SIDE
  17  * instrumentation.
  18  * Compound literals are part of the C99 and C11 standards, but not
  19  * part of the C++ standards. They are supported by most C++ compilers
  20  * though.
  21  *
  22  * Example use:
  23  * static struct mystruct *var = LTTNG_UST_COMPOUND_LITERAL(struct mystruct, { 1, 2, 3 });
  24  */
  25 #define SIDE_COMPOUND_LITERAL(type, ...)   (type[]) { __VA_ARGS__ }
  26
  27 #define side_likely(x)          __builtin_expect(!!(x), 1)
  28 #define side_unlikely(x)        __builtin_expect(!!(x), 0)
  29
  30 #define SIDE_PARAM(...) __VA_ARGS__
  31
  32 /*
  33  * side_container_of - Get the address of an object containing a field.
  34  *
  35  * @ptr: pointer to the field.
  36  * @type: type of the object.
  37  * @member: name of the field within the object.
  38  */
  39 #define side_container_of(ptr, type, member)                            \
  40         __extension__                                                   \
  41         ({                                                              \
  42                 const __typeof__(((type *) NULL)->member) * __ptr = (ptr); \
  43                 (type *)((char *)__ptr - offsetof(type, member));       \
  44         })
  45
  46 #if defined(__SIZEOF_LONG__)
  47 #define SIDE_BITS_PER_LONG      (__SIZEOF_LONG__ * 8)
  48 #elif defined(_LP64)
  49 #define SIDE_BITS_PER_LONG      64
  50 #else
  51 #define SIDE_BITS_PER_LONG      32
  52 #endif
  53
  54 #endif /* _SIDE_MACROS_H */