* mmtrace.c: Lint.

1 files changed, 163 insertions, 0 deletions

diff --git a/mmalloc/mmtrace.c b/mmalloc/mmtrace.c
new file mode 100644
index 0000000..f3f47b4
--- /dev/null
+++ b/mmalloc/mmtrace.c
@@ -0,0 +1,163 @@
+/* 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);
+}
+