gen/assumes.h

   1 #ifndef __OSX_ASSUMES_H__
   2 #define __OSX_ASSUMES_H__
   3
   4 #include <sys/cdefs.h>
   5
   6 __BEGIN_DECLS
   7
   8 #include <Availability.h>
   9 #include <stdlib.h>
  10 #include <stdint.h>
  11 #include <stdarg.h>
  12 #include <stdbool.h>
  13 #include <asl.h>
  14
  15 #if __GNUC__
  16 #define osx_fastpath(x) ((typeof(x))__builtin_expect((long)(x), ~0l))
  17 #define osx_slowpath(x) ((typeof(x))__builtin_expect((long)(x), 0l))
  18 #define osx_constant(x) __builtin_constant_p((x))
  19
  20 #define __OSX_COMPILETIME_ASSERT__(e) ({ \
  21         char __compile_time_assert__[(e) ? 1 : -1];     \
  22         (void)__compile_time_assert__; \
  23 })
  24 #else
  25 #define osx_fastpath(x) (x)
  26 #define osx_slowpath(x) (x)
  27 #define osx_constant(x) ((long)0)
  28
  29 #define __OSX_COMPILETIME_ASSERT__(e) (e)
  30 #endif /* __GNUC__ */
  31
  32 #define osx_assumes(e) ({ \
  33         typeof(e) _e = osx_fastpath(e); /* Force evaluation of 'e' */ \
  34         if (!_e) { \
  35                 if (osx_constant(e)) { \
  36                         __OSX_COMPILETIME_ASSERT__(e); \
  37                 } \
  38                 _osx_assumes_log((uintptr_t)_e); \
  39         } \
  40         _e; \
  41 })
  42
  43 #define osx_assumes_zero(e) ({ \
  44         typeof(e) _e = osx_slowpath(e); /* Force evaluation of 'e' */ \
  45         if (_e) { \
  46                 if (osx_constant(e)) { \
  47                         __OSX_COMPILETIME_ASSERT__(!e); \
  48                 } \
  49                 _osx_assumes_log((uintptr_t)_e); \
  50         } \
  51         _e; \
  52 })
  53
  54 __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_4_3)
  55 extern void
  56 _osx_assumes_log(uint64_t code);
  57
  58 __END_DECLS
  59
  60 #endif /* __OSX_ASSUMES_H__ */