apt-pkg/contrib/system.h

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: system.h,v 1.3 1999/12/10 23:40:29 jgg Exp $
   4 /* ######################################################################
   5
   6    System Header - Usefull private definitions
   7
   8    This source is placed in the Public Domain, do with it what you will
   9    It was originally written by Brian C. White.
  10
  11    ##################################################################### */
  12                                                                         /*}}}*/
  13 // Private header
  14 #ifndef SYSTEM_H
  15 #define SYSTEM_H
  16
  17 // MIN_VAL(SINT16) will return -0x8000 and MAX_VAL(SINT16) = 0x7FFF
  18 #define MIN_VAL(t)      (((t)(-1) > 0) ? (t)( 0) : (t)(((1L<<(sizeof(t)*8-1))  )))
  19 #define MAX_VAL(t)      (((t)(-1) > 0) ? (t)(-1) : (t)(((1L<<(sizeof(t)*8-1))-1)))
  20
  21 // Min/Max functions
  22 #if !defined(MIN)
  23 #if defined(__HIGHC__)
  24 #define MIN(x,y) _min(x,y)
  25 #define MAX(x,y) _max(x,y)
  26 #endif
  27
  28 // GNU C++ has a min/max operator <coolio>
  29 #if defined(__GNUG__)
  30 #define MIN(A,B) ((A) <? (B))
  31 #define MAX(A,B) ((A) >? (B))
  32 #endif
  33
  34 /* Templates tend to mess up existing code that uses min/max because of the
  35    strict matching requirements */
  36 #if !defined(MIN)
  37 #define MIN(A,B) ((A) < (B)?(A):(B))
  38 #define MAX(A,B) ((A) > (B)?(A):(B))
  39 #endif
  40 #endif
  41
  42 /* Bound functions, bound will return the value b within the limits a-c
  43    bounv will change b so that it is within the limits of a-c. */
  44 #define _bound(a,b,c) MIN(c,MAX(b,a))
  45 #define _boundv(a,b,c) b = _bound(a,b,c)
  46 #define ABS(a) (((a) < (0)) ?-(a) : (a))
  47
  48 /* Usefull count macro, use on an array of things and it will return the
  49    number of items in the array */
  50 #define _count(a) (sizeof(a)/sizeof(a[0]))
  51
  52 // Flag Macros
  53 #define FLAG(f)                 (1L << (f))
  54 #define SETFLAG(v,f)    ((v) |= FLAG(f))
  55 #define CLRFLAG(v,f)    ((v) &=~FLAG(f))
  56 #define CHKFLAG(v,f)    ((v) &  FLAG(f) ? true : false)
  57
  58 // some nice optional GNUC features
  59 #if __GNUC__ >= 3
  60         #define __must_check    __attribute__ ((warn_unused_result))
  61         #define __deprecated    __attribute__ ((deprecated))
  62         /* likely() and unlikely() can be used to mark boolean expressions
  63            as (not) likely true which will help the compiler to optimise */
  64         #define likely(x)       __builtin_expect (!!(x), 1)
  65         #define unlikely(x)     __builtin_expect (!!(x), 0)
  66 #else
  67         #define __must_check    /* no warn_unused_result */
  68         #define __deprecated    /* no deprecated */
  69         #define likely(x)       (x)
  70         #define unlikely(x)     (x)
  71 #endif
  72
  73 // cold functions are unlikely() to be called
  74 #if (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) || __GNUC__ > 4
  75         #define __cold  __attribute__ ((__cold__))
  76 #else
  77         #define __cold  /* no cold marker */
  78 #endif
  79
  80 #ifdef __GNUG__
  81 // Methods have a hidden this parameter that is visible to this attribute
  82         #define __like_printf_1 __attribute__ ((format (printf, 2, 3)))
  83         #define __like_printf_2 __attribute__ ((format (printf, 3, 4)))
  84 #else
  85         #define __like_printf_1
  86         #define __like_printf_2
  87 #endif
  88
  89 #endif