ack/lang/cem/libcc.ansi/sys/malloc/realloc.c
2018-06-23 18:08:03 +02:00

46 lines
693 B
C

#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
#include "malloc.h"
#if ACKCONF_WANT_MALLOC
void* realloc(void* ptr, size_t size)
{
block_t* h;
size_t nblocks;
void* newptr;
if (size == 0)
{
free(ptr);
return NULL;
}
if (!ptr)
return malloc(size);
h = BLOCKOF(ptr);
nblocks = BLOCKCOUNT(size);
/* Overflow check. */
if (nblocks < size)
return NULL;
/* Shrinking the block? Don't bother doing anything (it's never worth it). */
if (nblocks <= h->size)
return ptr;
/* Allocate and copy. */
newptr = malloc(size);
if (!newptr)
return NULL;
memcpy(newptr, ptr, h->size * sizeof(block_t));
free(ptr);
return newptr;
}
#endif