windows-nt/Source/XPSP1/NT/base/crts/crtw32/heap/findaddr.c

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2020-09-26 03:20:57 -05:00
/***
*findaddr.c - Find a heap entry
*
* Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Defines the _heap_findaddr routine
*
*Revision History:
* 07-06-89 JCR Module created.
* 07-18-89 JCR Return -1 if nothing in heap
* 11-13-89 GJF Fixed copyright
* 12-04-89 GJF Renamed header file (now heap.h). Also, some tuning.
* 12-18-89 GJF Added explicit _cdecl to function definition
* 03-09-90 GJF Replaced _cdecl with _CALLTYPE1, added #include
* <cruntime.h> and removed #include <register.h>.
* 09-27-90 GJF New-style function declarator.
* 04-06-93 SKS Replace _CRTAPI* with __cdecl
* 05-01-95 GJF Made conditional on WINHEAP.
*
*******************************************************************************/
#ifndef WINHEAP
#include <cruntime.h>
#include <heap.h>
#include <stddef.h>
#define TRUE 1
/***
*int _heap_findaddr() - Find a heap entry
*
*Purpose:
* Given an address, find the corresponding heap entry.
*
*Entry:
* void * address = address to look for
* PBLKDESC * ppdesc = pointer to pointer to heap descriptor to be
* filled in by this routine.
*
*Exit:
*
* _HEAPFIND_EXACT = 0 = exact fit, pdesc holds heap descriptor address
* _HEAPFIND_WITHIN = 1 = not exact fit, pdesc holds previous heap
* descriptor address
*
* _HEAPFIND_BEFORE = -1 = address is before the heap (pdesc NOT filled in)
* _HEAPFIND_AFTER = -2 = address is after the heap (pdesc NOT filled in)
* _HEAPFIND_EMPTY = -3 = no memory in heap (pdesc NOT filled in)
*
* [If return is negative, supplied pdesc is NOT filled in.]
*
*Uses:
*
*Exceptions:
*
*******************************************************************************/
int __cdecl _heap_findaddr (
void * address,
_PBLKDESC * ppdesc
)
{
REG1 _PBLKDESC pcurr;
/*
* See if heap there's anything in the heap
*/
if (_heap_desc.pfirstdesc == &_heap_desc.sentinel)
return(_HEAPFIND_EMPTY);
/*
* See if entry is in the heap or not
*/
if (_ADDRESS(_heap_desc.pfirstdesc) > address)
return(_HEAPFIND_BEFORE);
if (_ADDRESS(&_heap_desc.sentinel) <= address)
return(_HEAPFIND_AFTER);
/*
* Find the entry
*/
#ifdef DEBUG
for (pcurr = _heap_desc.pfirstdesc; pcurr != &_heap_desc.sentinel;
pcurr = pcurr->pnextdesc) {
#else
for (pcurr = _heap_desc.pfirstdesc; TRUE; pcurr = pcurr->pnextdesc) {
#endif
if ( _ADDRESS(pcurr->pnextdesc) > address ) {
/* Address is contained in this entry */
*ppdesc = pcurr;
/* Check for an exact fit */
if ( _ADDRESS(pcurr) == address)
return(_HEAPFIND_EXACT);
else
return(_HEAPFIND_WITHIN);
}
}
#ifdef DEBUG
/* Should never reach here! */
_heap_abort();
#endif
}
#endif /* WINHEAP */