libiberty/xmemdup.c

   1 /* xmemdup.c -- Duplicate a memory buffer, using xmalloc.
   2    This trivial function is in the public domain.
   3    Jeff Garzik, September 1999.  */
   4
   5 /*
   6
   7 @deftypefn Replacement void* xmemdup (void *@var{input}, @
   8   size_t @var{copy_size}, size_t @var{alloc_size})
   9
  10 Duplicates a region of memory without fail.  First, @var{alloc_size} bytes
  11 are allocated, then @var{copy_size} bytes from @var{input} are copied into
  12 it, and the new memory is returned.  If fewer bytes are copied than were
  13 allocated, the remaining memory is zeroed.
  14
  15 @end deftypefn
  16
  17 */
  18
  19 #ifdef HAVE_CONFIG_H
  20 #include "config.h"
  21 #endif
  22 #include "ansidecl.h"
  23 #include "libiberty.h"
  24
  25 #include <sys/types.h> /* For size_t. */
  26 #ifdef HAVE_STRING_H
  27 #include <string.h>
  28 #else
  29 # ifdef HAVE_STRINGS_H
  30 #  include <strings.h>
  31 # endif
  32 #endif
  33
  34 PTR
  35 xmemdup (const PTR input, size_t copy_size, size_t alloc_size)
  36 {
  37   PTR output = xmalloc (alloc_size);
  38   if (alloc_size > copy_size)
  39     memset ((char *) output + copy_size, 0, alloc_size - copy_size);
  40   return (PTR) memcpy (output, input, copy_size);
  41 }