/* More debugging hooks for `mmalloc'. Copyright 1991, 1992, 1994 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 file is part of the GNU C Library. The GNU C 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. The GNU C 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 the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include <stdio.h> #include "mmprivate.h" static void tr_break PARAMS ((void)); static void tr_freehook PARAMS ((PTR, PTR)); static PTR tr_mallochook PARAMS ((PTR, size_t)); static PTR tr_reallochook PARAMS ((PTR, PTR, size_t)); #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. */ fprintf (mallstream, "- %08lx\n", (unsigned long) 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. */ fprintf (mallstream, "+ %08lx %x\n", (unsigned long) 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. */ fprintf (mallstream, "! %08lx %x\n", (unsigned long) ptr, size); else fprintf (mallstream, "< %08lx\n> %08lx %x\n", (unsigned long) ptr, (unsigned long) 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/mmcheckf) 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); 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); }