/***
*realloc.c - Win32 realloc heap routine
*
*	Copyright (c) 1991-1995, Microsoft Corporation.	All rights reserved.
*
*Purpose:
*
*Revision History:
*	01-10-92  JCR	Module created.
*	02-04-92  GJF	Replaced windows.h with oscalls.h.
*	05-06-92  DJM	POSIX support.
*	09-09-92  SRW	Fixed _POSIX_ to allow movement when growing.
*	09-23-92  SRW	Change winheap code to call NT directly always
*	10-28-92  SRW	Change winheap code to call Heap????Ex calls
*	11-05-92  SKS	Change name of variable "CrtHeap" to "_crtheap"
*	11-07-92  SRW   _NTIDW340 replaced by linkopts\betacmp.c
*	11-16-92  SRW	Heap???Ex functions renamed to Heap???
*	10-21-93  GJF	Replace _CALLTYPE1 with _cdecl. Cleaned format up.
*	09-21-94  GJF	Put in support for user-specified new handler.
*	04-06-95  GJF	Added support for debug heap.
*
*******************************************************************************/

#include <cruntime.h>
#include <malloc.h>
#include <winheap.h>
#include <windows.h>
#include <internal.h>
#include <dbgint.h>

#ifndef _POSIX_

#include <new.h>

#ifndef DLL_FOR_WIN32S

extern _PNH _pnhHeap;	/* pointer to new() handler */

#endif	/* DLL_FOR_WIN32S */

#endif

/***
*void *realloc(void *pblock, size_t newsize) - reallocate a block of memory in
*	the heap
*
*Purpose:
*	Re-allocates a block in the heap to newsize bytes. newsize may be
*	either greater or less than the original size of the block. The
*	re-allocation may result in moving the block as well as changing
*	the size. If the block is moved, the contents of the original block
*	are copied over.
*
*	Special ANSI Requirements:
*
*	(1) realloc(NULL, newsize) is equivalent to malloc(newsize)
*
*	(2) realloc(pblock, 0) is equivalent to free(pblock) (except that
*	    NULL is returned)
*
*	(3) if the realloc() fails, the object pointed to by pblock is left
*	    unchanged
*
*Entry:
*	void *pblock	- pointer to block in the heap previously allocated
*			  by a call to malloc(), realloc() or _expand().
*
*	size_t newsize	- requested size for the re-allocated block
*
*Exit:
*	Success:  Pointer to the re-allocated memory block
*	Failure:  NULL
*
*Uses:
*
*Exceptions:
*	If pblock does not point to a valid allocation block in the heap,
*	realloc() will behave unpredictably and probably corrupt the heap.
*
*******************************************************************************/

void * __cdecl _realloc_base(
	void * pblock,
	size_t n
	)
{
	void *retp;

	/* if ptr is NULL, call malloc */
	if ( pblock == (void *) NULL )
		return( _malloc_base( n ) );

	/* if ptr is !NULL and size is 0, call free and return NULL */
	if ( n == 0 ) {
		_free_base( pblock );
		return( (void *)NULL );
	}

#ifndef _POSIX_
	for (;;) {
#endif	/* _POSIX_ */

		retp = HeapReAlloc( _crtheap,
				    0,
				    pblock,
				    n
				  );
#ifndef _POSIX_
		if ( (retp != NULL) || (_newmode == 0) || (_pnhHeap == NULL)
		     || ((*_pnhHeap)(n) == 0) )
#endif  /* ndef _POSIX_ */
			return( (void *)retp );
#ifndef _POSIX_
        }
#endif	/* ndef _POSIX_ */

}