libiberty/hex.c

   1 /* Hex character manipulation support.
   2    Copyright (C) 1995, 2001 Free Software Foundation, Inc.
   3
   4 This file is part of the libiberty library.
   5 Libiberty is free software; you can redistribute it and/or
   6 modify it under the terms of the GNU Library General Public
   7 License as published by the Free Software Foundation; either
   8 version 2 of the License, or (at your option) any later version.
   9
  10 Libiberty is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 Library General Public License for more details.
  14
  15 You should have received a copy of the GNU Library General Public
  16 License along with libiberty; see the file COPYING.LIB.  If
  17 not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18 Boston, MA 02111-1307, USA.  */
  19
  20 #include <stdio.h>  /* for EOF */
  21 #include "libiberty.h"
  22
  23 /*
  24
  25 @deftypefn Extension void hex_init (void)
  26
  27 Initializes the array mapping the current character set to
  28 corresponding hex values.  This function must be called before any
  29 call to @code{hex_p} or @code{hex_value}.  If you fail to call it, a
  30 default ASCII-based table will normally be used on ASCII systems.
  31
  32 @end deftypefn
  33
  34 @deftypefn Extension int hex_p (int @var{c})
  35
  36 Evaluates to non-zero if the given character is a valid hex character,
  37 or zero if it is not.  Note that the value you pass will be cast to
  38 @code{unsigned char} within the macro.
  39
  40 @end deftypefn
  41
  42 @deftypefn Extension int hex_value (int @var{c})
  43
  44 Returns the numeric equivalent of the given character when interpreted
  45 as a hexidecimal digit.  The result is undefined if you pass an
  46 invalid hex digit.  Note that the value you pass will be cast to
  47 @code{unsigned char} within the macro.
  48
  49 @end deftypefn
  50
  51 @undocumented _hex_array_size
  52 @undocumented _hex_bad
  53 @undocumented _hex_value
  54
  55 */
  56
  57
  58 /* Are we ASCII? */
  59 #if '\n' == 0x0A && ' ' == 0x20 && '0' == 0x30 \
  60   && 'A' == 0x41 && 'a' == 0x61 && '!' == 0x21 \
  61   && EOF == -1
  62
  63 const char _hex_value[_hex_array_size] =
  64 {
  65   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* NUL SOH STX ETX */
  66   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* EOT ENQ ACK BEL */
  67   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* BS  HT  LF  VT  */
  68   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* FF  CR  SO  SI  */
  69   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* DLE DC1 DC2 DC3 */
  70   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* DC4 NAK SYN ETB */
  71   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* CAN EM  SUB ESC */
  72   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* FS  GS  RS  US  */
  73
  74   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* SP  !   "   #   */
  75   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* $   %   &   '   */
  76   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* (   )   *   +   */
  77   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* ,   -   .   /   */
  78   0,        1,        2,        3,          /* 0   1   2   3   */
  79   4,        5,        6,        7,          /* 4   5   6   7   */
  80   8,        9,        _hex_bad, _hex_bad,   /* 8   9   :   ;   */
  81   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* <   =   >   ?   */
  82
  83   _hex_bad, 10,       11,       12,         /* @   A   B   C   */
  84   13,       14,       15,       _hex_bad,   /* D   E   F   G   */
  85   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* H   I   J   K   */
  86   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* L   M   N   O   */
  87   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* P   Q   R   S   */
  88   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* T   U   V   W   */
  89   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* X   Y   Z   [   */
  90   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* \   ]   ^   _   */
  91
  92   _hex_bad, 10,       11,       12,         /* `   a   b   c   */
  93   13,       14,       15,       _hex_bad,   /* d   e   f   g   */
  94   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* h   i   j   k   */
  95   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* l   m   n   o   */
  96   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* p   q   r   s   */
  97   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* t   u   v   w   */
  98   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* x   y   z   {   */
  99   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* |   }   ~   DEL */
 100
 101   /* The high half of unsigned char, all values are _hex_bad.  */
 102   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 103   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 104   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 105   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 106   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 107   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 108   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 109   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 110
 111   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 112   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 113   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 114   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 115   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 116   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 117   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 118   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 119
 120   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 121   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 122   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 123   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 124   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 125   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 126   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 127   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 128
 129   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 130   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 131   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 132   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 133   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 134   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 135   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 136   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 137 };
 138 #define HEX_TABLE_INITIALIZED
 139
 140 #else
 141
 142 char _hex_value[_hex_array_size];
 143
 144 #endif /* not ASCII */
 145
 146 void
 147 hex_init ()
 148 {
 149 #ifndef HEX_TABLE_INITIALIZED
 150   int i;
 151
 152   for (i=0; i<_hex_array_size; i++)
 153     {
 154       switch (i)
 155         {
 156         case '0': _hex_value[i] = 0; break;
 157         case '1': _hex_value[i] = 1; break;
 158         case '2': _hex_value[i] = 2; break;
 159         case '3': _hex_value[i] = 3; break;
 160         case '4': _hex_value[i] = 4; break;
 161         case '5': _hex_value[i] = 5; break;
 162         case '6': _hex_value[i] = 6; break;
 163         case '7': _hex_value[i] = 7; break;
 164         case '8': _hex_value[i] = 8; break;
 165         case '9': _hex_value[i] = 9; break;
 166
 167         case 'a': case 'A': _hex_value[i] = 10; break;
 168         case 'b': case 'B': _hex_value[i] = 11; break;
 169         case 'c': case 'C': _hex_value[i] = 12; break;
 170         case 'd': case 'D': _hex_value[i] = 13; break;
 171         case 'e': case 'E': _hex_value[i] = 14; break;
 172         case 'f': case 'F': _hex_value[i] = 15; break;
 173
 174         default:
 175           _hex_value[i] = _hex_bad;
 176           break;
 177         }
 178     }
 179 #endif
 180 }