libiberty/hex.c

   1 /* Hex character manipulation support.
   2    Copyright (C) 1995-2023 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., 51 Franklin Street - Fifth Floor,
  18 Boston, MA 02110-1301, USA.  */
  19
  20 #include <stdio.h>  /* for EOF */
  21 #ifdef HAVE_CONFIG_H
  22 #include "config.h"
  23 #endif
  24 #include "libiberty.h"
  25 #include "safe-ctype.h" /* for HOST_CHARSET_ASCII */
  26
  27 #if EOF != -1
  28  #error "hex.c requires EOF == -1"
  29 #endif
  30
  31 /*
  32
  33 @deftypefn Extension void hex_init (void)
  34
  35 Initializes the array mapping the current character set to
  36 corresponding hex values.  This function must be called before any
  37 call to @code{hex_p} or @code{hex_value}.  If you fail to call it, a
  38 default ASCII-based table will normally be used on ASCII systems.
  39
  40 @end deftypefn
  41
  42 @deftypefn Extension int hex_p (int @var{c})
  43
  44 Evaluates to non-zero if the given character is a valid hex character,
  45 or zero if it is not.  Note that the value you pass will be cast to
  46 @code{unsigned char} within the macro.
  47
  48 @end deftypefn
  49
  50 @deftypefn Extension {unsigned int} hex_value (int @var{c})
  51
  52 Returns the numeric equivalent of the given character when interpreted
  53 as a hexadecimal digit.  The result is undefined if you pass an
  54 invalid hex digit.  Note that the value you pass will be cast to
  55 @code{unsigned char} within the macro.
  56
  57 The @code{hex_value} macro returns @code{unsigned int}, rather than
  58 signed @code{int}, to make it easier to use in parsing addresses from
  59 hex dump files: a signed @code{int} would be sign-extended when
  60 converted to a wider unsigned type --- like @code{bfd_vma}, on some
  61 systems.
  62
  63 @end deftypefn
  64
  65 @undocumented _hex_array_size
  66 @undocumented _hex_bad
  67 @undocumented _hex_value
  68
  69 */
  70
  71
  72 /* Are we ASCII? */
  73 #if HOST_CHARSET == HOST_CHARSET_ASCII
  74
  75 const unsigned char _hex_value[_hex_array_size] =
  76 {
  77   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* NUL SOH STX ETX */
  78   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* EOT ENQ ACK BEL */
  79   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* BS  HT  LF  VT  */
  80   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* FF  CR  SO  SI  */
  81   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* DLE DC1 DC2 DC3 */
  82   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* DC4 NAK SYN ETB */
  83   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* CAN EM  SUB ESC */
  84   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* FS  GS  RS  US  */
  85
  86   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* SP  !   "   #   */
  87   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* $   %   &   '   */
  88   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* (   )   *   +   */
  89   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* ,   -   .   /   */
  90   0,        1,        2,        3,          /* 0   1   2   3   */
  91   4,        5,        6,        7,          /* 4   5   6   7   */
  92   8,        9,        _hex_bad, _hex_bad,   /* 8   9   :   ;   */
  93   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* <   =   >   ?   */
  94
  95   _hex_bad, 10,       11,       12,         /* @   A   B   C   */
  96   13,       14,       15,       _hex_bad,   /* D   E   F   G   */
  97   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* H   I   J   K   */
  98   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* L   M   N   O   */
  99   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* P   Q   R   S   */
 100   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* T   U   V   W   */
 101   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* X   Y   Z   [   */
 102   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* \   ]   ^   _   */
 103
 104   _hex_bad, 10,       11,       12,         /* `   a   b   c   */
 105   13,       14,       15,       _hex_bad,   /* d   e   f   g   */
 106   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* h   i   j   k   */
 107   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* l   m   n   o   */
 108   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* p   q   r   s   */
 109   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* t   u   v   w   */
 110   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* x   y   z   {   */
 111   _hex_bad, _hex_bad, _hex_bad, _hex_bad,   /* |   }   ~   DEL */
 112
 113   /* The high half of unsigned char, all values are _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   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 120   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 121   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 122
 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   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 129   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 130   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 131
 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   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 138   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 139   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 140
 141   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 142   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 143   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 144   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 145   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 146   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 147   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 148   _hex_bad, _hex_bad, _hex_bad, _hex_bad,
 149 };
 150 #define HEX_TABLE_INITIALIZED
 151
 152 #else
 153
 154 unsigned char _hex_value[_hex_array_size];
 155
 156 #endif /* not ASCII */
 157
 158 void
 159 hex_init (void)
 160 {
 161 #ifndef HEX_TABLE_INITIALIZED
 162   int i;
 163
 164   for (i=0; i<_hex_array_size; i++)
 165     {
 166       switch (i)
 167         {
 168         case '0': _hex_value[i] = 0; break;
 169         case '1': _hex_value[i] = 1; break;
 170         case '2': _hex_value[i] = 2; break;
 171         case '3': _hex_value[i] = 3; break;
 172         case '4': _hex_value[i] = 4; break;
 173         case '5': _hex_value[i] = 5; break;
 174         case '6': _hex_value[i] = 6; break;
 175         case '7': _hex_value[i] = 7; break;
 176         case '8': _hex_value[i] = 8; break;
 177         case '9': _hex_value[i] = 9; break;
 178
 179         case 'a': case 'A': _hex_value[i] = 10; break;
 180         case 'b': case 'B': _hex_value[i] = 11; break;
 181         case 'c': case 'C': _hex_value[i] = 12; break;
 182         case 'd': case 'D': _hex_value[i] = 13; break;
 183         case 'e': case 'E': _hex_value[i] = 14; break;
 184         case 'f': case 'F': _hex_value[i] = 15; break;
 185
 186         default:
 187           _hex_value[i] = _hex_bad;
 188           break;
 189         }
 190     }
 191 #endif
 192 }