src/built-in.h

   1 /*
   2  * transsip - the telephony network
   3  * By Daniel Borkmann <daniel@transsip.org>
   4  * Copyright 2011, 2012 Daniel Borkmann <dborkma@tik.ee.ethz.ch>,
   5  * Swiss federal institute of technology (ETH Zurich)
   6  * Subject to the GPL, version 2.
   7  */
   8
   9 #ifndef BUILT_IN_H
  10 #define BUILT_IN_H
  11
  12 #ifndef __aligned_16
  13 # define __aligned_16           __attribute__((aligned(16)))
  14 #endif
  15
  16 #ifndef likely
  17 # define likely(x)              __builtin_expect(!!(x), 1)
  18 #endif
  19
  20 #ifndef unlikely
  21 # define unlikely(x)            __builtin_expect(!!(x), 0)
  22 #endif
  23
  24 #ifndef __extension__
  25 # define __extension__
  26 #endif
  27
  28 #ifndef __deprecated
  29 # define __deprecated           /* unimplemented */
  30 #endif
  31
  32 #ifndef __read_mostly
  33 # define __read_mostly          __attribute__((__section__(".data.read_mostly")))
  34 #endif
  35
  36 #ifndef __always_inline
  37 # define __always_inline        inline
  38 #endif
  39
  40 #ifndef __hidden
  41 # define __hidden               __attribute__((visibility("hidden")))
  42 #endif
  43
  44 /* From Linux */
  45 #ifndef array_size
  46 # define array_size(x)          (sizeof(x) / sizeof((x)[0]) + __must_be_array(x))
  47 #endif
  48
  49 #ifndef __must_be_array
  50 # define __must_be_array(x)             \
  51         build_bug_on_zero(__builtin_types_compatible_p(typeof(x), typeof(&x[0])))
  52 #endif
  53
  54 #ifndef max
  55 # define max(a, b)                      \
  56         ({                              \
  57                 typeof (a) _a = (a);    \
  58                 typeof (b) _b = (b);    \
  59                 _a > _b ? _a : _b;      \
  60         })
  61 #endif
  62
  63 #ifndef min
  64 # define min(a, b)                      \
  65         ({                              \
  66                 typeof (a) _a = (a);    \
  67                 typeof (b) _b = (b);    \
  68                 _a < _b ? _a : _b;      \
  69         })
  70 #endif
  71
  72 #define anon(return_type, body_and_args)                \
  73         ({                                              \
  74                 return_type __fn__ body_and_args        \
  75                 __fn__;                                 \
  76         })
  77
  78 /*
  79  * Example usage:
  80  *
  81  * qsort(&argv[1], argc - 1, sizeof(argv[1]),
  82  *       anon(int, (const void * a, const void * b) {
  83  *               return strcmp(*(char * const *) a, *(char * const *) b);
  84  *       }));
  85  */
  86
  87 #ifndef bug
  88 # define bug()                  __builtin_trap()
  89 #endif
  90
  91 #ifndef build_bug_on_zero
  92 # define build_bug_on_zero(e)   (sizeof(char[1 - 2 * !!(e)]) - 1)
  93 #endif
  94
  95 #endif /* BUILT_IN_H */