sdcc/device/lib/calloc.c

   1 /*-------------------------------------------------------------------------
   2    calloc.c - allocate memory.
   3
   4    Copyright (C) 2015, Philipp Klaus Krause, pkk@spth.de
   5
   6    This library is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published by the
   8    Free Software Foundation; either version 2, or (at your option) any
   9    later version.
  10
  11    This library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this library; see the file COPYING. If not, write to the
  18    Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
  19    MA 02110-1301, USA.
  20
  21    As a special exception, if you link this library with other files,
  22    some of which are compiled with SDCC, to produce an executable,
  23    this library does not by itself cause the resulting executable to
  24    be covered by the GNU General Public License. This exception does
  25    not however invalidate any other reasons why the executable file
  26    might be covered by the GNU General Public License.
  27 -------------------------------------------------------------------------*/
  28
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <stdint.h>
  32
  33 #if defined(__SDCC_mcs51) || defined(__SDCC_ds390) || defined(__SDCC_ds400)
  34 #define HEAPSPACE __xdata
  35 #elif defined(__SDCC_pdk13) || defined(__SDCC_pdk14) || defined(__SDCC_pdk15)
  36 #define HEAPSPACE __near
  37 #else
  38 #define HEAPSPACE
  39 #endif
  40
  41 #if defined(__SDCC_mcs51) || defined(__SDCC_ds390) || defined(__SDCC_ds400)
  42 void HEAPSPACE *calloc (size_t nmemb, size_t size)
  43 #else
  44 void *calloc (size_t nmemb, size_t size)
  45 #endif
  46 {
  47         void HEAPSPACE *ptr;
  48
  49         unsigned long msize = (unsigned long)nmemb * (unsigned long)size;
  50
  51         _Static_assert(sizeof(unsigned long) >= sizeof(size_t) * 2,
  52                 "size_t too large wrt. unsigned long for overflow check");
  53
  54         if (msize > SIZE_MAX)
  55                 return(0);
  56
  57         if (ptr = malloc(msize))
  58                 memset(ptr, 0, msize);
  59
  60         return(ptr);
  61 }
  62