apt-pkg/contrib/macros.h

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 /* ######################################################################
   4
   5    Macros Header - Various useful macro definitions
   6
   7    This source is placed in the Public Domain, do with it what you will
   8    It was originally written by Brian C. White.
   9
  10    ##################################################################### */
  11                                                                         /*}}}*/
  12 // Private header
  13 #ifndef MACROS_H
  14 #define MACROS_H
  15
  16 // MIN_VAL(SINT16) will return -0x8000 and MAX_VAL(SINT16) = 0x7FFF
  17 #define MIN_VAL(t)      (((t)(-1) > 0) ? (t)( 0) : (t)(((1L<<(sizeof(t)*8-1))  )))
  18 #define MAX_VAL(t)      (((t)(-1) > 0) ? (t)(-1) : (t)(((1L<<(sizeof(t)*8-1))-1)))
  19
  20 // Min/Max functions
  21 #if !defined(MIN)
  22 #if defined(__HIGHC__)
  23 #define MIN(x,y) _min(x,y)
  24 #define MAX(x,y) _max(x,y)
  25 #endif
  26
  27 // GNU C++ has a min/max operator <coolio>
  28 #if defined(__GNUG__)
  29 #define MIN(A,B) ((A) <? (B))
  30 #define MAX(A,B) ((A) >? (B))
  31 #endif
  32
  33 /* Templates tend to mess up existing code that uses min/max because of the
  34    strict matching requirements */
  35 #if !defined(MIN)
  36 #define MIN(A,B) ((A) < (B)?(A):(B))
  37 #define MAX(A,B) ((A) > (B)?(A):(B))
  38 #endif
  39 #endif
  40
  41 /* Bound functions, bound will return the value b within the limits a-c
  42    bounv will change b so that it is within the limits of a-c. */
  43 #define _bound(a,b,c) MIN(c,MAX(b,a))
  44 #define _boundv(a,b,c) b = _bound(a,b,c)
  45 #define ABS(a) (((a) < (0)) ?-(a) : (a))
  46
  47 /* Usefull count macro, use on an array of things and it will return the
  48    number of items in the array */
  49 #define _count(a) (sizeof(a)/sizeof(a[0]))
  50
  51 // Flag Macros
  52 #define FLAG(f)                 (1L << (f))
  53 #define SETFLAG(v,f)    ((v) |= FLAG(f))
  54 #define CLRFLAG(v,f)    ((v) &=~FLAG(f))
  55 #define CHKFLAG(v,f)    ((v) &  FLAG(f) ? true : false)
  56
  57 // some nice optional GNUC features
  58 #if __GNUC__ >= 3
  59         #define __must_check    __attribute__ ((warn_unused_result))
  60 #ifndef __deprecated
  61         #define __deprecated    __attribute__ ((deprecated))
  62 #endif
  63         /* likely() and unlikely() can be used to mark boolean expressions
  64            as (not) likely true which will help the compiler to optimise */
  65         #define likely(x)       __builtin_expect (!!(x), 1)
  66         #define unlikely(x)     __builtin_expect (!!(x), 0)
  67 #else
  68         #define __must_check    /* no warn_unused_result */
  69         #define __deprecated    /* no deprecated */
  70         #define likely(x)       (x)
  71         #define unlikely(x)     (x)
  72 #endif
  73
  74 // cold functions are unlikely() to be called
  75 #if (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) || __GNUC__ > 4
  76         #define __cold  __attribute__ ((__cold__))
  77 #else
  78         #define __cold  /* no cold marker */
  79 #endif
  80
  81 #ifdef __GNUG__
  82 // Methods have a hidden this parameter that is visible to this attribute
  83         #define __like_printf_1 __attribute__ ((format (printf, 2, 3)))
  84         #define __like_printf_2 __attribute__ ((format (printf, 3, 4)))
  85 #else
  86         #define __like_printf_1
  87         #define __like_printf_2
  88 #endif
  89
  90 #endif