src/built_in.h

   1 /*
   2  * transsip - the telephony toolkit
   3  * By Daniel Borkmann <daniel@transsip.org>
   4  * Copyright 2011, 2012 Daniel Borkmann <dborkma@tik.ee.ethz.ch>
   5  * Subject to the GPL, version 2.
   6  */
   7
   8 #ifndef BUILT_IN_H
   9 #define BUILT_IN_H
  10
  11 #include <stdint.h>
  12 #include <assert.h>
  13
  14 typedef uint64_t        u64;
  15 typedef uint32_t        u32;
  16 typedef uint16_t        u16;
  17 typedef uint8_t         u8;
  18
  19 #ifndef __aligned_16
  20 # define __aligned_16           __attribute__((aligned(16)))
  21 #endif
  22
  23 #ifndef likely
  24 # define likely(x)              __builtin_expect(!!(x), 1)
  25 #endif
  26
  27 #ifndef unlikely
  28 # define unlikely(x)            __builtin_expect(!!(x), 0)
  29 #endif
  30
  31 #ifndef __extension__
  32 # define __extension__
  33 #endif
  34
  35 #ifndef __deprecated
  36 # define __deprecated           /* unimplemented */
  37 #endif
  38
  39 #ifndef __read_mostly
  40 # define __read_mostly          __attribute__((__section__(".data.read_mostly")))
  41 #endif
  42
  43 #ifndef __always_inline
  44 # define __always_inline        inline
  45 #endif
  46
  47 #ifndef __hidden
  48 # define __hidden               __attribute__((visibility("hidden")))
  49 #endif
  50
  51 /* From Linux */
  52 #ifndef array_size
  53 # define array_size(x)          (sizeof(x) / sizeof((x)[0]) + __must_be_array(x))
  54 #endif
  55
  56 #ifndef __must_be_array
  57 # define __must_be_array(x)             \
  58         build_bug_on_zero(__builtin_types_compatible_p(typeof(x), typeof(&x[0])))
  59 #endif
  60
  61 #ifndef max
  62 # define max(a, b)                      \
  63         ({                              \
  64                 typeof (a) _a = (a);    \
  65                 typeof (b) _b = (b);    \
  66                 _a > _b ? _a : _b;      \
  67         })
  68 #endif
  69
  70 #ifndef min
  71 # define min(a, b)                      \
  72         ({                              \
  73                 typeof (a) _a = (a);    \
  74                 typeof (b) _b = (b);    \
  75                 _a < _b ? _a : _b;      \
  76         })
  77 #endif
  78
  79 #define anon(return_type, body_and_args)                \
  80         ({                                              \
  81                 return_type __fn__ body_and_args        \
  82                 __fn__;                                 \
  83         })
  84
  85 /*
  86  * Example usage:
  87  *
  88  * qsort(&argv[1], argc - 1, sizeof(argv[1]),
  89  *       anon(int, (const void * a, const void * b) {
  90  *               return strcmp(*(char * const *) a, *(char * const *) b);
  91  *       }));
  92  */
  93
  94 #ifndef bug
  95 # define bug()                  assert(0)
  96 #endif
  97
  98 #ifndef bug_on
  99 # define bug_on(cond)           assert(!(cond))
 100 #endif
 101
 102 #ifndef build_bug_on_zero
 103 # define build_bug_on_zero(e)   (sizeof(char[1 - 2 * !!(e)]) - 1)
 104 #endif
 105
 106 #endif /* BUILT_IN_H */