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Diffstat (limited to 'mmalloc/mmtrace.c')
| -rw-r--r-- | mmalloc/mmtrace.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/mmalloc/mmtrace.c b/mmalloc/mmtrace.c new file mode 100644 index 0000000..563c860 --- /dev/null +++ b/mmalloc/mmtrace.c @@ -0,0 +1,171 @@ +/* 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); +} + |