safe_mem.c

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#include "util.h"

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/*---------------------------------------------------------------------------*/
/* Static function prototypes                                                */
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/** \file safe_mem.c
 *
 \brief These are interface routines to be placed between a program and the
 system memory allocator.  

 It forces well-defined semantics for several 'borderline' cases:

 <ul>
 <li>   <code>malloc()</code> of a 0 size object is guaranteed to return something
        which is not 0, and can safely be freed (but not dereferenced)
 <li>   <code>free()</code> accepts (silently) an 0 pointer
 <li>   realloc of a 0 pointer is allowed, and is equiv. to <code>malloc()</code>
 </ul>

*/


/**
  * \brief Safe malloc
  */

char *
MMalloc (int size)
{
  char *p;

  if (size <= 0)
    {
      size = sizeof (int);
    }
  if ((p = (char *) malloc ((unsigned) size)) == NIL (char))
    {
      (void) fflush (stdout);
      (void) fprintf (stderr, "\nout of memory allocating %ld bytes\n", size);
      exit (1);
    }
  return p;
}


/**
  * \brief Safe realloc
  */

char *
MMrealloc (char *obj, int size)
{
  char *p;

  if (obj == NIL (char))
    {
      return MMalloc (size);
    }
  if (size <= 0)
    {
      size = sizeof (long);
    }
  if ((p = (char *) realloc (obj, (unsigned) size)) == NIL (char))
    {
      (void) fflush (stdout);
      (void) fprintf (stderr, "\nout of memory re-allocating %ld bytes\n",
              size);
      exit (1);
    }
  return p;
}


/**
  * \brief Safe free
  */

void
MMfree (char *obj)
{
  if (obj != 0)
    {
      free (obj);
    }
}