msdos/tailor.c

   1 /* tailor.c -- target dependent functions
   2  * Copyright (C) 1992-1993 Jean-loup Gailly
   3  * This is free software; you can redistribute it and/or modify it under the
   4  * terms of the GNU General Public License, see the file COPYING.
   5  */
   6
   7 /* tailor.c is a bunch of non portable routines.
   8  * It should be kept to a minimum.
   9  */
  10
  11 #include "tailor.h"
  12 #include "gzip.h"
  13
  14 #ifndef lint
  15 static char rcsid[] = "$Id$";
  16 #endif
  17
  18 #ifdef __TURBOC__
  19
  20 /************************/
  21 /*  Function fcalloc()  */
  22 /************************/
  23
  24 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
  25  * and farmalloc(64K) returns a pointer with an offset of 8, so we
  26  * must fix the pointer. Warning: the pointer must be put back to its
  27  * original form in order to free it, use fcfree().
  28  * For MSC, use halloc instead of this function (see tailor.h).
  29  */
  30 static ush ptr_offset = 0;
  31
  32 void * fcalloc(items, size)
  33     unsigned items; /* number of items */
  34     unsigned size;  /* item size */
  35 {
  36     void * buf = farmalloc((ulg)items*size + 16L);
  37     if (buf == NULL) return NULL;
  38     /* Normalize the pointer to seg:0 */
  39     if (ptr_offset == 0) {
  40         ptr_offset = (ush)((uch*)buf-0);
  41     } else if (ptr_offset != (ush)((uch*)buf-0)) {
  42         error("inconsistent ptr_offset");
  43     }
  44     *((ush*)&buf+1) += (ptr_offset + 15) >> 4;
  45     *(ush*)&buf = 0;
  46     return buf;
  47 }
  48
  49 void fcfree(ptr)
  50     void *ptr; /* region allocated with fcalloc() */
  51 {
  52     /* Put the pointer back to its original form: */
  53     *((ush*)&ptr+1) -= (ptr_offset + 15) >> 4;
  54     *(ush*)&ptr = ptr_offset;
  55     farfree(ptr);
  56  }
  57
  58 #endif /* __TURBOC__ */