git.sur5r.net Git - cc65/blob - src/cc65/hexval.c

   1 /*****************************************************************************/
   2 /*                                                                           */
   3 /*                                   hexval.c                                */
   4 /*                                                                           */
   5 /*                     Convert hex digits to numeric values                  */
   6 /*                                                                           */
   7 /*                                                                           */
   8 /*                                                                           */
   9 /* (C) 2002      Ullrich von Bassewitz                                       */
  10 /*               Wacholderweg 14                                             */
  11 /*               D-70597 Stuttgart                                           */
  12 /* EMail:        uz@cc65.org                                                 */
  13 /*                                                                           */
  14 /*                                                                           */
  15 /* This software is provided 'as-is', without any expressed or implied       */
  16 /* warranty.  In no event will the authors be held liable for any damages    */
  17 /* arising from the use of this software.                                    */
  18 /*                                                                           */
  19 /* Permission is granted to anyone to use this software for any purpose,     */
  20 /* including commercial applications, and to alter it and redistribute it    */
  21 /* freely, subject to the following restrictions:                            */
  22 /*                                                                           */
  23 /* 1. The origin of this software must not be misrepresented; you must not   */
  24 /*    claim that you wrote the original software. If you use this software   */
  25 /*    in a product, an acknowledgment in the product documentation would be  */
  26 /*    appreciated but is not required.                                       */
  27 /* 2. Altered source versions must be plainly marked as such, and must not   */
  28 /*    be misrepresented as being the original software.                      */
  29 /* 3. This notice may not be removed or altered from any source              */
  30 /*    distribution.                                                          */
  31 /*                                                                           */
  32 /*****************************************************************************/
  33
  34
  35
  36 /* common */
  37 #include "chartype.h"
  38
  39 /* cc65 */
  40 #include "error.h"
  41 #include "hexval.h"
  42
  43
  44
  45 /*****************************************************************************/
  46 /*                                   Code                                    */
  47 /*****************************************************************************/
  48
  49
  50
  51 unsigned HexVal (int C)
  52 /* Convert a hex digit into a value. The function will emit an error for
  53  * invalid hex digits.
  54  */
  55 {
  56     if (!IsXDigit (C)) {
  57         Error ("Invalid hexadecimal digit: `%c'", C);
  58     }
  59     if (IsDigit (C)) {
  60         return C - '0';
  61     } else {
  62         return toupper (C) - 'A' + 10;
  63     }
  64 }
  65
  66
  67