binutils-gdb/mmalloc/mmtrace.c

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1992-06-30 01:38:26 +02:00
/* More debugging hooks for `mmalloc'.
Copyright 1991, 1992 Free Software Foundation
Written April 2, 1991 by John Gilmore of Cygnus Support
Based on mcheck.c by Mike Haertel.
Modified Mar 1992 by Fred Fish. (fnf@cygnus.com)
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include <stdio.h>
#include "mmalloc.h"
#ifndef __GNU_LIBRARY__
extern char *getenv ();
#endif
static FILE *mallstream;
#if 0 /* FIXME: Disabled for now. */
static char mallenv[] = "MALLOC_TRACE";
static char mallbuf[BUFSIZ]; /* Buffer for the output. */
#endif
/* Address to breakpoint on accesses to... */
static PTR mallwatch;
/* Old hook values. */
static void (*old_mfree_hook) PARAMS ((PTR, PTR));
static PTR (*old_mmalloc_hook) PARAMS ((PTR, size_t));
static PTR (*old_mrealloc_hook) PARAMS ((PTR, PTR, size_t));
/* This function is called when the block being alloc'd, realloc'd, or
freed has an address matching the variable "mallwatch". In a debugger,
set "mallwatch" to the address of interest, then put a breakpoint on
tr_break. */
static void
tr_break ()
{
}
static void
tr_freehook (md, ptr)
PTR md;
PTR ptr;
{
struct mdesc *mdp;
mdp = MD_TO_MDP (md);
/* Be sure to print it first. */
(void) fprintf (mallstream, "- %08x\n", (unsigned int) ptr);
if (ptr == mallwatch)
tr_break ();
mdp -> mfree_hook = old_mfree_hook;
mfree (md, ptr);
mdp -> mfree_hook = tr_freehook;
}
static PTR
tr_mallochook (md, size)
PTR md;
size_t size;
{
PTR hdr;
struct mdesc *mdp;
mdp = MD_TO_MDP (md);
mdp -> mmalloc_hook = old_mmalloc_hook;
hdr = (PTR) mmalloc (md, size);
mdp -> mmalloc_hook = tr_mallochook;
/* We could be printing a NULL here; that's OK. */
(void) fprintf (mallstream, "+ %08x %x\n", (unsigned int) hdr, size);
if (hdr == mallwatch)
tr_break ();
return (hdr);
}
static PTR
tr_reallochook (md, ptr, size)
PTR md;
PTR ptr;
size_t size;
{
PTR hdr;
struct mdesc *mdp;
mdp = MD_TO_MDP (md);
if (ptr == mallwatch)
tr_break ();
mdp -> mfree_hook = old_mfree_hook;
mdp -> mmalloc_hook = old_mmalloc_hook;
mdp -> mrealloc_hook = old_mrealloc_hook;
hdr = (PTR) mrealloc (md, ptr, size);
mdp -> mfree_hook = tr_freehook;
mdp -> mmalloc_hook = tr_mallochook;
mdp -> mrealloc_hook = tr_reallochook;
if (hdr == NULL)
/* Failed realloc. */
(void) fprintf (mallstream, "! %08x %x\n", (unsigned int) ptr, size);
else
(void) fprintf (mallstream, "< %08x\n> %08x %x\n", (unsigned int) ptr,
(unsigned int) hdr, size);
if (hdr == mallwatch)
tr_break ();
return hdr;
}
/* We enable tracing if either the environment variable MALLOC_TRACE
is set, or if the variable mallwatch has been patched to an address
that the debugging user wants us to stop on. When patching mallwatch,
don't forget to set a breakpoint on tr_break! */
int
mmtrace ()
{
#if 0 /* FIXME! This is disabled for now until we figure out how to
maintain a stack of hooks per heap, since we might have other
hooks (such as set by mmcheck) active also. */
char *mallfile;
mallfile = getenv (mallenv);
if (mallfile != NULL || mallwatch != NULL)
{
mallstream = fopen (mallfile != NULL ? mallfile : "/dev/null", "w");
if (mallstream != NULL)
{
/* Be sure it doesn't mmalloc its buffer! */
setbuf (mallstream, mallbuf);
(void) fprintf (mallstream, "= Start\n");
old_mfree_hook = mdp -> mfree_hook;
mdp -> mfree_hook = tr_freehook;
old_mmalloc_hook = mdp -> mmalloc_hook;
mdp -> mmalloc_hook = tr_mallochook;
old_mrealloc_hook = mdp -> mrealloc_hook;
mdp -> mrealloc_hook = tr_reallochook;
}
}
#endif /* 0 */
return (1);
}