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/* Standard debugging hooks for `malloc'.
Copyright 1990, 1991, 1992 Free Software Foundation
Written May 1989 by Mike Haertel.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation. */
#ifndef _MALLOC_INTERNAL
#define _MALLOC_INTERNAL
#include <malloc.h>
#endif
/* Old hook values. */
static void (*old_free_hook) __P ((__ptr_t ptr));
static __ptr_t (*old_malloc_hook) __P ((size_t size));
static __ptr_t (*old_realloc_hook) __P ((__ptr_t ptr, size_t size));
/* Function to call when something awful happens. */
extern void abort __P ((void));
static void (*abortfunc) __P ((void)) = (void (*) __P ((void))) abort;
/* Arbitrary magical numbers. */
#define MAGICWORD 0xfedabeeb
#define MAGICBYTE ((char) 0xd7)
struct hdr
{
size_t size; /* Exact size requested by user. */
unsigned long int magic; /* Magic number to check header integrity. */
};
static void checkhdr __P ((__const struct hdr *));
static void
checkhdr (hdr)
__const struct hdr *hdr;
{
if (hdr->magic != MAGICWORD || ((char *) &hdr[1])[hdr->size] != MAGICBYTE)
(*abortfunc) ();
}
static void freehook __P ((__ptr_t));
static void
freehook (ptr)
__ptr_t ptr;
{
struct hdr *hdr = ((struct hdr *) ptr) - 1;
checkhdr (hdr);
hdr->magic = 0;
__free_hook = old_free_hook;
free (hdr);
__free_hook = freehook;
}
static __ptr_t mallochook __P ((size_t));
static __ptr_t
mallochook (size)
size_t size;
{
struct hdr *hdr;
__malloc_hook = old_malloc_hook;
hdr = (struct hdr *) __libc_malloc (sizeof (struct hdr) + size + 1);
__malloc_hook = mallochook;
if (hdr == NULL)
return NULL;
hdr->size = size;
hdr->magic = MAGICWORD;
((char *) &hdr[1])[size] = MAGICBYTE;
return (__ptr_t) (hdr + 1);
}
static __ptr_t reallochook __P ((__ptr_t, size_t));
static __ptr_t
reallochook (ptr, size)
__ptr_t ptr;
size_t size;
{
struct hdr *hdr = ((struct hdr *) ptr) - 1;
checkhdr (hdr);
__free_hook = old_free_hook;
__malloc_hook = old_malloc_hook;
__realloc_hook = old_realloc_hook;
hdr = (struct hdr *) __libc_realloc ((__ptr_t) hdr, sizeof (struct hdr) + size + 1);
__free_hook = freehook;
__malloc_hook = mallochook;
__realloc_hook = reallochook;
if (hdr == NULL)
return NULL;
hdr->size = size;
((char *) &hdr[1])[size] = MAGICBYTE;
return (__ptr_t) (hdr + 1);
}
void
mcheck (func)
void (*func) __P ((void));
{
static int mcheck_used = 0;
if (func != NULL)
abortfunc = func;
/* These hooks may not be safely inserted if malloc is already in use. */
if (!__malloc_initialized && !mcheck_used)
{
old_free_hook = __free_hook;
__free_hook = freehook;
old_malloc_hook = __malloc_hook;
__malloc_hook = mallochook;
old_realloc_hook = __realloc_hook;
__realloc_hook = reallochook;
mcheck_used = 1;
}
}
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