* configure (extra_debugging): New variable. EXTRA_DEBUGGING

conditionally generated in config.h.

* gc.c (break_obj): New static variable.
(mark_obj): Debugging feature: if the object is the one stored in
break_obj and not yet reached, then call breakpt.
(deheap): New debugging function for viewing regions of the heaps.

* lib.c (breakpt): New function.

* lib.h (breakpt): Declared.

1 files changed, 15 insertions, 0 deletions

diff --git a/configure b/configure
index 2b012c43..6255fc9a 100755
--- a/configure
+++ b/configure
@@ -135,6 +135,7 @@ lex_dbg_flags=${lex_dbg_flags-}
 txr_dbg_opts=${txr_dbg_opts---gc-debug}
 valgrind=${valgrind-}
 lit_align=${lit_align-}
+extra_debugging=${extra_debugging-}
 
 #
 # If --help was given (or --help=<nonempty> or help=<nonempty>) then
@@ -334,6 +335,11 @@ valgrind [$valgrind]
   Valgrind integration means that when the program is running under valgrind,
   it advises valgrind about stack memory locations accessed by the garbage
   collector, to suppress diagnostics about uninitialized accesses.
+
+extra_debugging [$extra_debugging]
+
+  Use --extra_debugging to configure some additional debugging features,
+  which incur a run-time penalty.
 !
   exit 1
 fi
@@ -922,6 +928,15 @@ else
 fi
 
 #
+# Extra debugging.
+#
+
+if [ -n "$extra_debugging" ] ; then
+  printf "Configuring extra debugging, as requested ...\n"
+  printf "#define EXTRA_DEBUGGING 1\n" >> config.h
+fi
+
+#
 # Clean up
 #