inc/types.h

   1 #ifndef JOS_INC_TYPES_H
   2 #define JOS_INC_TYPES_H
   3
   4 #ifndef NULL
   5 #define NULL ((void*) 0)
   6 #endif
   7
   8 // Represents true-or-false values
   9 typedef int bool;
  10
  11 // Explicitly-sized versions of integer types
  12 typedef __signed char int8_t;
  13 typedef unsigned char uint8_t;
  14 typedef short int16_t;
  15 typedef unsigned short uint16_t;
  16 typedef int int32_t;
  17 typedef unsigned int uint32_t;
  18 typedef long long int64_t;
  19 typedef unsigned long long uint64_t;
  20
  21 // Pointers and addresses are 32 bits long.
  22 // We use pointer types to represent virtual addresses,
  23 // uintptr_t to represent the numerical values of virtual addresses,
  24 // and physaddr_t to represent physical addresses.
  25 typedef int32_t intptr_t;
  26 typedef uint32_t uintptr_t;
  27 typedef uint32_t physaddr_t;
  28
  29 // Page numbers are 32 bits long.
  30 typedef uint32_t ppn_t;
  31
  32 // size_t is used for memory object sizes.
  33 typedef uint32_t size_t;
  34 // ssize_t is a signed version of ssize_t, used in case there might be an
  35 // error return.
  36 typedef int32_t ssize_t;
  37
  38 // off_t is used for file offsets and lengths.
  39 typedef int32_t off_t;
  40
  41 // Efficient min and max operations
  42 #define MIN(_a, _b)                                             \
  43 ({                                                              \
  44         typeof(_a) __a = (_a);                                  \
  45         typeof(_b) __b = (_b);                                  \
  46         __a <= __b ? __a : __b;                                 \
  47 })
  48 #define MAX(_a, _b)                                             \
  49 ({                                                              \
  50         typeof(_a) __a = (_a);                                  \
  51         typeof(_b) __b = (_b);                                  \
  52         __a >= __b ? __a : __b;                                 \
  53 })
  54
  55 // Rounding operations (efficient when n is a power of 2)
  56 // Round down to the nearest multiple of n
  57 #define ROUNDDOWN(a, n)                                         \
  58 ({                                                              \
  59         uint32_t __a = (uint32_t) (a);                          \
  60         (typeof(a)) (__a - __a % (n));                          \
  61 })
  62 // Round up to the nearest multiple of n
  63 #define ROUNDUP(a, n)                                           \
  64 ({                                                              \
  65         uint32_t __n = (uint32_t) (n);                          \
  66         (typeof(a)) (ROUNDDOWN((uint32_t) (a) + __n - 1, __n)); \
  67 })
  68
  69 // Return the offset of 'member' relative to the beginning of a struct type
  70 #define offsetof(type, member)  ((size_t) (&((type*)0)->member))
  71
  72 #endif /* !JOS_INC_TYPES_H */