asm/rdstrnum.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 1996-2016 The NASM Authors - All Rights Reserved
   4  *   See the file AUTHORS included with the NASM distribution for
   5  *   the specific copyright holders.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following
   9  *   conditions are met:
  10  *
  11  *   * Redistributions of source code must retain the above copyright
  12  *     notice, this list of conditions and the following disclaimer.
  13  *   * Redistributions in binary form must reproduce the above
  14  *     copyright notice, this list of conditions and the following
  15  *     disclaimer in the documentation and/or other materials provided
  16  *     with the distribution.
  17  *
  18  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  19  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  20  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  21  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  22  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  23  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  25  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  26  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  29  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  30  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  * ----------------------------------------------------------------------- */
  33
  34 /*
  35  * rdstrnum.c
  36  *
  37  * This converts a NASM string to an integer, used when a string
  38  * is used in an integer constant context.  This is a binary conversion,
  39  * not a conversion from a numeric constant in text form.
  40  */
  41
  42 #include "compiler.h"
  43 #include "nasmlib.h"
  44 #include "nasm.h"
  45
  46 int64_t readstrnum(char *str, int length, bool *warn)
  47 {
  48     int64_t charconst = 0;
  49     int i;
  50
  51     *warn = false;
  52
  53     str += length;
  54     if (globalbits == 64) {
  55         for (i = 0; i < length; i++) {
  56             if (charconst & UINT64_C(0xFF00000000000000))
  57                 *warn = true;
  58             charconst = (charconst << 8) + (uint8_t)*--str;
  59         }
  60     } else {
  61         for (i = 0; i < length; i++) {
  62             if (charconst & 0xFF000000UL)
  63                 *warn = true;
  64             charconst = (charconst << 8) + (uint8_t)*--str;
  65         }
  66     }
  67     return charconst;
  68 }