Initial revision

[deliverable/binutils-gdb.git] / gdb / mtrace.c

/* More debugging hooks for `malloc'.
   Copyright 1991 Free Software Foundation
		  Written April 2, 1991 by John Gilmore of Cygnus Support
		  Based on mcheck.c by Mike Haertel.

   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 1, 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.

   The author may be reached (Email) at the address mike@ai.mit.edu,
   or (US mail) as Mike Haertel c/o Free Software Foundation. */

#include <stdio.h>
#include "ansidecl.h"
#include <stdlib.h>
#include "gmalloc.h"

extern char *getenv();

FILE *mallstream;
char mallenv[] = "MALLOC_TRACE";
static char mallbuf[BUFSIZ];		/* Buffer for the output */

/* Address to breakpoint on accesses to... */
PTR mallwatch;

/* Old hook values.  */
static void EXFUN((*old_free_hook), (PTR ptr));
static PTR EXFUN((*old_malloc_hook), (size_t size));
static PTR EXFUN((*old_realloc_hook), (PTR ptr, size_t size));

/* 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.  */

void
tr_break()
{
  ;
}

static void
DEFUN(tr_freehook, (ptr), PTR ptr)
{
  fprintf(mallstream, "- %08x\n", ptr);	/* Be sure to print it first */
  if (ptr == mallwatch)
    tr_break();
  __free_hook = old_free_hook;
  free(ptr);
  __free_hook = tr_freehook;
}

static PTR
DEFUN(tr_mallochook, (size), size_t size)
{
  PTR hdr;

  __malloc_hook = old_malloc_hook;
  hdr = malloc(size);
  __malloc_hook = tr_mallochook;

  /* We could be printing a NULL here; that's OK */
  fprintf (mallstream, "+ %08x %x\n", hdr, size);

  if (hdr == mallwatch)
    tr_break();

  return hdr;
}

static PTR
DEFUN(tr_reallochook, (ptr, size), PTR ptr AND size_t size)
{
  PTR hdr;

  if (ptr == mallwatch)
    tr_break();

  __free_hook = old_free_hook;
  __malloc_hook = old_malloc_hook;
  __realloc_hook = old_realloc_hook;
  hdr = realloc(ptr, size);
  __free_hook = tr_freehook;
  __malloc_hook = tr_mallochook;
  __realloc_hook = tr_reallochook;
  if (hdr == NULL) {
    fprintf (mallstream, "! %08x %x\n", ptr, size);	/* Failed realloc */
  } else {
    fprintf (mallstream, "< %08x\n> %08x %x\n", ptr, hdr, size);
  }

  if (hdr == mallwatch)
    tr_break();

  return hdr;
}

void
mtrace()
{
  char *mallfile;

  mallfile = getenv (mallenv);
  if (mallfile) {
    mallstream = fopen (mallfile, "w");
    if (mallstream) {
      /* Be sure it doesn't malloc its buffer! */
      setbuf (mallstream, mallbuf);
      fprintf (mallstream, "= Start\n");
      old_free_hook = __free_hook;
      __free_hook = tr_freehook;
      old_malloc_hook = __malloc_hook;
      __malloc_hook = tr_mallochook;
      old_realloc_hook = __realloc_hook;
      __realloc_hook = tr_reallochook;
    }
  }
}