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 #include <limits.h>
  11
  12 /* Helper macros */
  13
  14 #define SIDE_ARRAY_SIZE(arr)    (sizeof(arr) / sizeof((arr)[0]))
  15
  16 /*
  17  * Compound literals with static storage are needed by SIDE
  18  * instrumentation.
  19  * Compound literals are part of the C99 and C11 standards, but not
  20  * part of the C++ standards. They are supported by most C++ compilers
  21  * though.
  22  *
  23  * Example use:
  24  * static struct mystruct *var = LTTNG_UST_COMPOUND_LITERAL(struct mystruct, { 1, 2, 3 });
  25  */
  26 #define SIDE_COMPOUND_LITERAL(type, ...)   (type[]) { __VA_ARGS__ }
  27
  28 #define side_likely(x)          __builtin_expect(!!(x), 1)
  29 #define side_unlikely(x)        __builtin_expect(!!(x), 0)
  30
  31 #define SIDE_PARAM(...) __VA_ARGS__
  32
  33 /*
  34  * side_container_of - Get the address of an object containing a field.
  35  *
  36  * @ptr: pointer to the field.
  37  * @type: type of the object.
  38  * @member: name of the field within the object.
  39  */
  40 #define side_container_of(ptr, type, member)                            \
  41         __extension__                                                   \
  42         ({                                                              \
  43                 const __typeof__(((type *) NULL)->member) * __ptr = (ptr); \
  44                 (type *)((char *)__ptr - offsetof(type, member));       \
  45         })
  46
  47 #define side_struct_field_sizeof(_struct, _field) \
  48         sizeof(((_struct * )NULL)->_field)
  49
  50 #if defined(__SIZEOF_LONG__)
  51 #define SIDE_BITS_PER_LONG      (__SIZEOF_LONG__ * 8)
  52 #elif defined(_LP64)
  53 #define SIDE_BITS_PER_LONG      64
  54 #else
  55 #define SIDE_BITS_PER_LONG      32
  56 #endif
  57
  58 #define SIDE_PACKED     __attribute__((packed))
  59
  60 #endif /* _SIDE_MACROS_H */