altos/lisp: Deal with memory compation in the middle of operations

Handle memory compaction in places where we've got pointers into the
heap across an allocation operation. Either re-compute the values from
managed global references or add new roots across the allocation.

Signed-off-by: Keith Packard <keithp@keithp.com>

7 files changed, 137 insertions, 135 deletions

diff --git a/src/lisp/ao_lisp.h b/src/lisp/ao_lisp.h
index 6122a2ed..60a97f2c 100644
--- a/src/lisp/ao_lisp.h
+++ b/src/lisp/ao_lisp.h
@@ -510,8 +510,8 @@ ao_lisp_frame_ref(struct ao_lisp_frame *frame, ao_poly atom);
 struct ao_lisp_frame *
 ao_lisp_frame_new(int num);
 
-struct ao_lisp_frame *
-ao_lisp_frame_add(struct ao_lisp_frame *frame, ao_poly atom, ao_poly val);
+int
+ao_lisp_frame_add(struct ao_lisp_frame **frame, ao_poly atom, ao_poly val);
 
 void
 ao_lisp_frame_print(ao_poly p);
@@ -538,8 +538,7 @@ ao_poly
 ao_lisp_macro(struct ao_lisp_cons *cons);
 
 ao_poly
-ao_lisp_lambda_eval(struct ao_lisp_lambda *lambda,
-		    struct ao_lisp_cons *cons);
+ao_lisp_lambda_eval(void);
 
 /* error */
 
diff --git a/src/lisp/ao_lisp_atom.c b/src/lisp/ao_lisp_atom.c
index 5c6d5a67..efa4f621 100644
--- a/src/lisp/ao_lisp_atom.c
+++ b/src/lisp/ao_lisp_atom.c
@@ -147,7 +147,7 @@ ao_lisp_atom_set(ao_poly atom, ao_poly val)
 	if (ref)
 		*ref = val;
 	else
-		ao_lisp_frame_global = ao_lisp_frame_add(ao_lisp_frame_global, atom, val);
+		ao_lisp_frame_add(&ao_lisp_frame_global, atom, val);
 	return val;
 }
 
diff --git a/src/lisp/ao_lisp_cons.c b/src/lisp/ao_lisp_cons.c
index 855079b8..cd8a8d1d 100644
--- a/src/lisp/ao_lisp_cons.c
+++ b/src/lisp/ao_lisp_cons.c
@@ -67,7 +67,13 @@ const struct ao_lisp_type ao_lisp_cons_type = {
 struct ao_lisp_cons *
 ao_lisp_cons_cons(ao_poly car, struct ao_lisp_cons *cdr)
 {
-	struct ao_lisp_cons	*cons = ao_lisp_alloc(sizeof (struct ao_lisp_cons));
+	struct ao_lisp_cons	*cons;
+
+	ao_lisp_root_add(&ao_lisp_cons_type, &cdr);
+	ao_lisp_root_poly_add(&car);
+	cons = ao_lisp_alloc(sizeof (struct ao_lisp_cons));
+	ao_lisp_root_clear(&car);
+	ao_lisp_root_clear(&cdr);
 	if (!cons)
 		return NULL;
 	cons->car = car;
diff --git a/src/lisp/ao_lisp_eval.c b/src/lisp/ao_lisp_eval.c
index c5addcb0..ae2436b8 100644
--- a/src/lisp/ao_lisp_eval.c
+++ b/src/lisp/ao_lisp_eval.c
@@ -12,7 +12,7 @@
  * General Public License for more details.
  */
 
-#define DBG_EVAL 1
+#define DBG_EVAL 0
 #include "ao_lisp.h"
 #include <assert.h>
 
@@ -46,19 +46,20 @@ stack_move(void *addr)
 	struct ao_lisp_stack	*stack = addr;
 
 	while (stack) {
-		void	*prev;
+		struct ao_lisp_stack	*prev;
 		int	ret;
 		(void) ao_lisp_poly_move(&stack->sexprs, 0);
 		(void) ao_lisp_poly_move(&stack->values, 0);
 		(void) ao_lisp_poly_move(&stack->values_tail, 0);
 		(void) ao_lisp_poly_move(&stack->frame, 0);
 		prev = ao_lisp_poly_stack(stack->prev);
-		ret = ao_lisp_move(&ao_lisp_stack_type, &prev);
+		ret = ao_lisp_move_memory((void **) &prev,
+					  sizeof (struct ao_lisp_stack));
 		if (prev != ao_lisp_poly_stack(stack->prev))
 			stack->prev = ao_lisp_stack_poly(prev);
 		if (ret)
 			break;
-		stack = ao_lisp_poly_stack(stack->prev);
+		stack = prev;
 	}
 }
 
@@ -101,8 +102,8 @@ ao_lisp_stack_push(void)
 	ao_lisp_stack = stack;
 	ao_lisp_stack_reset(stack);
 	DBGI("stack push\n");
-	DBG_IN();
 	DBG_FRAMES();
+	DBG_IN();
 	return 1;
 }
 
@@ -236,37 +237,11 @@ static int
 ao_lisp_eval_val(void)
 {
 	DBGI("val: "); DBG_POLY(ao_lisp_v); DBG("\n");
-#if 0
-	if (ao_lisp_stack->macro) {
-		DBGI(".. end macro %d\n", ao_lisp_stack->macro);
-		DBGI(".. sexprs       "); DBG_POLY(ao_lisp_stack->sexprs); DBG("\n");
-		DBGI(".. values       "); DBG_POLY(ao_lisp_stack->values); DBG("\n");
-		ao_lisp_frames_dump();
-
-		ao_lisp_stack_pop();
-#if 0
-		/*
-		 * Re-use the current stack to evaluate
-		 * the value from the macro
-		 */
-		ao_lisp_stack->state = eval_sexpr;
-		ao_lisp_frame_current = ao_lisp_poly_frame(ao_lisp_stack->macro_frame);
-		ao_lisp_stack->frame = ao_lisp_stack->macro_frame;
-		ao_lisp_stack->macro = 0;
-		ao_lisp_stack->macro_frame = AO_LISP_NIL;
-		ao_lisp_stack->sexprs = AO_LISP_NIL;
-		ao_lisp_stack->values = AO_LISP_NIL;
-		ao_lisp_stack->values_tail = AO_LISP_NIL;
-#endif
-	} else
-#endif
-	{
-		/*
-		 * Value computed, pop the stack
-		 * to figure out what to do with the value
-		 */
-		ao_lisp_stack_pop();
-	}
+	/*
+	 * Value computed, pop the stack
+	 * to figure out what to do with the value
+	 */
+	ao_lisp_stack_pop();
 	DBGI("..state %d\n", ao_lisp_stack ? ao_lisp_stack->state : -1);
 	return 1;
 }
@@ -305,7 +280,6 @@ ao_lisp_eval_formal(void)
 			break;
 		case AO_LISP_FUNC_MACRO:
 			/* Evaluate the result once more */
-			prev = ao_lisp_stack;
 			ao_lisp_stack->state = eval_sexpr;
 			if (!ao_lisp_stack_push())
 				return 0;
@@ -313,6 +287,7 @@ ao_lisp_eval_formal(void)
 			/* After the function returns, take that
 			 * value and re-evaluate it
 			 */
+			prev = ao_lisp_poly_stack(ao_lisp_stack->prev);
 			ao_lisp_stack->state = eval_sexpr;
 			ao_lisp_stack->sexprs = prev->sexprs;
 			prev->sexprs = AO_LISP_NIL;
@@ -400,8 +375,7 @@ ao_lisp_eval_exec(void)
 	case AO_LISP_LAMBDA:
 		ao_lisp_stack->state = eval_sexpr;
 		DBGI(".. frame "); DBG_POLY(ao_lisp_frame_poly(ao_lisp_frame_current)); DBG("\n");
-		ao_lisp_v = ao_lisp_lambda_eval(ao_lisp_poly_lambda(ao_lisp_v),
-						ao_lisp_poly_cons(ao_lisp_stack->values));
+		ao_lisp_v = ao_lisp_lambda_eval();
 		DBGI(".. sexpr "); DBG_POLY(ao_lisp_v); DBG("\n");
 		DBGI(".. frame "); DBG_POLY(ao_lisp_frame_poly(ao_lisp_frame_current)); DBG("\n");
 		break;
@@ -464,12 +438,11 @@ ao_lisp_eval_cond_test(void)
 		struct ao_lisp_cons *car = ao_lisp_poly_cons(ao_lisp_poly_cons(ao_lisp_stack->sexprs)->car);
 		struct ao_lisp_cons *c = ao_lisp_poly_cons(car->cdr);
 
-		ao_lisp_stack->state = eval_val;
 		if (c) {
+			ao_lisp_stack->state = eval_sexpr;
 			ao_lisp_v = c->car;
-			if (!ao_lisp_stack_push())
-				return 0;
-		}
+		} else
+			ao_lisp_stack->state = eval_val;
 	} else {
 		ao_lisp_stack->sexprs = ao_lisp_poly_cons(ao_lisp_stack->sexprs)->cdr;
 		DBGI("next cond: "); DBG_POLY(ao_lisp_stack->sexprs); DBG("\n");
diff --git a/src/lisp/ao_lisp_frame.c b/src/lisp/ao_lisp_frame.c
index 7978f20a..90344719 100644
--- a/src/lisp/ao_lisp_frame.c
+++ b/src/lisp/ao_lisp_frame.c
@@ -174,8 +174,9 @@ ao_lisp_frame_new(int num)
 }
 
 static struct ao_lisp_frame *
-ao_lisp_frame_realloc(struct ao_lisp_frame *frame, int new_num)
+ao_lisp_frame_realloc(struct ao_lisp_frame **frame_ref, int new_num)
 {
+	struct ao_lisp_frame	*frame = *frame_ref;
 	struct ao_lisp_frame	*new;
 	int			copy;
 
@@ -184,34 +185,45 @@ ao_lisp_frame_realloc(struct ao_lisp_frame *frame, int new_num)
 	new = ao_lisp_frame_new(new_num);
 	if (!new)
 		return NULL;
+	/*
+	 * Re-fetch the frame as it may have moved
+	 * during the allocation
+	 */
+	frame = *frame_ref;
 	copy = new_num;
 	if (copy > frame->num)
 		copy = frame->num;
 	memcpy(new->vals, frame->vals, copy * sizeof (struct ao_lisp_val));
-	if (frame)
-		new->next = frame->next;
+	new->next = frame->next;
 	return new;
 }
 
-struct ao_lisp_frame *
-ao_lisp_frame_add(struct ao_lisp_frame *frame, ao_poly atom, ao_poly val)
+int
+ao_lisp_frame_add(struct ao_lisp_frame **frame_ref, ao_poly atom, ao_poly val)
 {
+	struct ao_lisp_frame *frame = *frame_ref;
 	ao_poly *ref = frame ? ao_lisp_frame_ref(frame, atom) : NULL;
+
 	if (!ref) {
 		int f;
+		ao_lisp_root_poly_add(&atom);
+		ao_lisp_root_poly_add(&val);
 		if (frame) {
 			f = frame->num;
-			frame = ao_lisp_frame_realloc(frame, f + 1);
+			frame = ao_lisp_frame_realloc(frame_ref, f + 1);
 		} else {
 			f = 0;
 			frame = ao_lisp_frame_new(1);
 		}
+		ao_lisp_root_clear(&atom);
+		ao_lisp_root_clear(&val);
 		if (!frame)
-			return NULL;
+			return 0;
+		*frame_ref = frame;
 		DBG ("add atom %s %d, val %d at %d\n", ao_lisp_poly_atom(atom)->name, OFFSET(atom), OFFSET(val), f);
 		frame->vals[f].atom = atom;
 		ref = &frame->vals[f].val;
 	}
 	*ref = val;
-	return frame;
+	return 1;
 }
diff --git a/src/lisp/ao_lisp_lambda.c b/src/lisp/ao_lisp_lambda.c
index cc5af4bc..8eafb187 100644
--- a/src/lisp/ao_lisp_lambda.c
+++ b/src/lisp/ao_lisp_lambda.c
@@ -133,18 +133,17 @@ ao_lisp_macro(struct ao_lisp_cons *cons)
 }
 
 ao_poly
-ao_lisp_lambda_eval(struct ao_lisp_lambda *lambda,
-		    struct ao_lisp_cons *cons)
+ao_lisp_lambda_eval(void)
 {
-	struct ao_lisp_cons	*code;
-	struct ao_lisp_cons	*args;
+	struct ao_lisp_lambda	*lambda = ao_lisp_poly_lambda(ao_lisp_v);
+	struct ao_lisp_cons	*cons = ao_lisp_poly_cons(ao_lisp_stack->values);
+	struct ao_lisp_cons	*code = ao_lisp_poly_cons(lambda->code);
+	struct ao_lisp_cons	*args = ao_lisp_poly_cons(ao_lisp_arg(code, 0));
 	struct ao_lisp_frame	*next_frame;
 	int			args_wanted;
 	int			args_provided;
 
-	code = ao_lisp_poly_cons(lambda->code);
 	DBGI("lambda "); DBG_POLY(ao_lisp_lambda_poly(lambda)); DBG("\n");
-	args = ao_lisp_poly_cons(ao_lisp_arg(code, 0));
 
 	args_wanted = ao_lisp_cons_length(args);
 
@@ -156,7 +155,15 @@ ao_lisp_lambda_eval(struct ao_lisp_lambda *lambda,
 		args_provided = 1;
 	if (args_wanted != args_provided)
 		return ao_lisp_error(AO_LISP_INVALID, "need %d args, not %d", args_wanted, args_provided);
+
 	next_frame = ao_lisp_frame_new(args_wanted);
+
+	/* Re-fetch all of the values in case something moved */
+	lambda = ao_lisp_poly_lambda(ao_lisp_v);
+	cons = ao_lisp_poly_cons(ao_lisp_stack->values);
+	code = ao_lisp_poly_cons(lambda->code);
+	args = ao_lisp_poly_cons(ao_lisp_arg(code, 0));
+
 	switch (lambda->args) {
 	case AO_LISP_FUNC_LAMBDA: {
 		int			f;
diff --git a/src/lisp/ao_lisp_mem.c b/src/lisp/ao_lisp_mem.c
index 66e09db0..b763d78b 100644
--- a/src/lisp/ao_lisp_mem.c
+++ b/src/lisp/ao_lisp_mem.c
@@ -28,32 +28,33 @@ uint8_t	ao_lisp_pool[AO_LISP_POOL] __attribute__((aligned(4)));
 #endif
 
 #if 0
-#define DBG_COLLECT_ALWAYS
+#define MDBG_COLLECT_ALWAYS
 #endif
 
 #if 0
-#define DBG_POOL
+#define MDBG_POOL
 #endif
 
 #if 0
-#define DBG_INCLUDE
-#define DBG_DUMP	0
-#define DBG_OFFSET(a)	((int) ((uint8_t *) (a) - ao_lisp_pool))
-#define DBG(...) printf(__VA_ARGS__)
-#define DBG_DO(a)	a
-static int move_dump = 1;
+#define MDBG_INCLUDE
+#define MDBG_DUMP	1
+#define MDBG_MOVE	0
+#define MDBG_OFFSET(a)	((int) ((uint8_t *) (a) - ao_lisp_pool))
+#define MDBG(...) printf(__VA_ARGS__)
+#define MDBG_DO(a)	a
+static int move_dump = MDBG_MOVE;
 static int move_depth;
-#define DBG_RESET() (move_depth = 0)
-#define DBG_MOVE(...) do { if(move_dump) { int d; for (d = 0; d < move_depth; d++) printf ("  "); printf(__VA_ARGS__); } } while (0)
-#define DBG_MOVE_IN()	(move_depth++)
-#define DBG_MOVE_OUT()	(move_depth--)
+#define MDBG_RESET() (move_depth = 0)
+#define MDBG_MOVE(...) do { if(move_dump) { int d; for (d = 0; d < move_depth; d++) printf ("  "); printf(__VA_ARGS__); } } while (0)
+#define MDBG_MOVE_IN()	(move_depth++)
+#define MDBG_MOVE_OUT()	(move_depth--)
 #else
-#define DBG(...)
-#define DBG_DO(a)
-#define DBG_RESET()
-#define DBG_MOVE(...)
-#define DBG_MOVE_IN()
-#define DBG_MOVE_OUT()
+#define MDBG(...)
+#define MDBG_DO(a)
+#define MDBG_RESET()
+#define MDBG_MOVE(...)
+#define MDBG_MOVE_IN()
+#define MDBG_MOVE_OUT()
 #endif
 
 uint8_t	ao_lisp_exception;
@@ -69,7 +70,7 @@ static struct ao_lisp_root	ao_lisp_root[AO_LISP_ROOT];
 
 static uint8_t	ao_lisp_busy[AO_LISP_POOL / 32];
 static uint8_t	ao_lisp_moving[AO_LISP_POOL / 32];
-static uint8_t	ao_lisp_cons[AO_LISP_POOL / 32];
+static uint8_t	ao_lisp_cons_note[AO_LISP_POOL / 32];
 static uint8_t	ao_lisp_cons_last[AO_LISP_POOL / 32];
 static uint8_t	ao_lisp_cons_noted;
 
@@ -78,6 +79,7 @@ uint16_t	ao_lisp_top;
 static inline void mark(uint8_t *tag, int offset) {
 	int	byte = offset >> 5;
 	int	bit = (offset >> 2) & 7;
+
 	tag[byte] |= (1 << bit);
 }
 
@@ -166,10 +168,11 @@ busy_object(uint8_t *tag, void *addr) {
 static void
 note_cons(void *addr)
 {
-	DBG_MOVE("note cons %d\n", DBG_OFFSET(addr));
+	MDBG_MOVE("note cons %d\n", MDBG_OFFSET(addr));
 	if (AO_LISP_IS_POOL(addr)) {
+		int	offset = (uint8_t *) addr - ao_lisp_pool;
 		ao_lisp_cons_noted = 1;
-		mark(ao_lisp_cons, (uint8_t *) addr - ao_lisp_pool);
+		mark(ao_lisp_cons_note, offset);
 	}
 }
 
@@ -182,11 +185,11 @@ move_object(void)
 {
 	int	i;
 
-	DBG_RESET();
-	DBG_MOVE("move %d -> %d\n", DBG_OFFSET(move_old), DBG_OFFSET(move_new));
-	DBG_MOVE_IN();
+	MDBG_RESET();
+	MDBG_MOVE("move %d -> %d\n", MDBG_OFFSET(move_old), MDBG_OFFSET(move_new));
+	MDBG_MOVE_IN();
 	memset(ao_lisp_moving, '\0', sizeof (ao_lisp_moving));
-	memset(ao_lisp_cons, '\0', sizeof (ao_lisp_cons));
+	memset(ao_lisp_cons_note, '\0', sizeof (ao_lisp_cons_note));
 	ao_lisp_cons_noted = 0;
 	for (i = 0; i < AO_LISP_ROOT; i++) {
 		if (!ao_lisp_root[i].addr)
@@ -195,10 +198,10 @@ move_object(void)
 			void *addr = *ao_lisp_root[i].addr;
 			if (!addr)
 				continue;
-			DBG_MOVE("root %d\n", DBG_OFFSET(addr));
+			MDBG_MOVE("root %d\n", MDBG_OFFSET(addr));
 			if (!ao_lisp_move(ao_lisp_root[i].type,
 					  ao_lisp_root[i].addr)) {
-				DBG_MOVE("root moves from %p to %p\n",
+				MDBG_MOVE("root moves from %p to %p\n",
 					 addr,
 					 *ao_lisp_root[i].addr);
 			}
@@ -207,31 +210,31 @@ move_object(void)
 			if (!p)
 				continue;
 			if (!ao_lisp_poly_move((ao_poly *) ao_lisp_root[i].addr, 0)) {
-				DBG_MOVE("root poly move from %04x to %04x\n",
+				MDBG_MOVE("root poly move from %04x to %04x\n",
 					 p, *(ao_poly *) ao_lisp_root[i].addr);
 			}
 		}
 	}
 	while (ao_lisp_cons_noted) {
-		memcpy(ao_lisp_cons_last, ao_lisp_cons, sizeof (ao_lisp_cons));
-		memset(ao_lisp_cons, '\0', sizeof (ao_lisp_cons));
+		memcpy(ao_lisp_cons_last, ao_lisp_cons_note, sizeof (ao_lisp_cons_note));
+		memset(ao_lisp_cons_note, '\0', sizeof (ao_lisp_cons_note));
 		ao_lisp_cons_noted = 0;
 		for (i = 0; i < AO_LISP_POOL; i += 4) {
 			if (busy(ao_lisp_cons_last, i)) {
 				void *addr = ao_lisp_pool + i;
-				DBG_MOVE("cons %d\n", DBG_OFFSET(addr));
+				MDBG_MOVE("cons %d\n", MDBG_OFFSET(addr));
 				if (!ao_lisp_move(&ao_lisp_cons_type, &addr)) {
-					DBG_MOVE("cons moves from %p to %p\n",
+					MDBG_MOVE("cons moves from %p to %p\n",
 						 ao_lisp_pool + i, addr);
 				}
 			}
 		}
 	}
-	DBG_MOVE_OUT();
-	DBG_MOVE("move done\n");
+	MDBG_MOVE_OUT();
+	MDBG_MOVE("move done\n");
 }
 
-#if DBG_DUMP
+#if MDBG_DUMP
 static void
 dump_busy(void)
 {
@@ -272,32 +275,32 @@ ao_lisp_mark_busy(void)
 	int i;
 
 	memset(ao_lisp_busy, '\0', sizeof (ao_lisp_busy));
-	memset(ao_lisp_cons, '\0', sizeof (ao_lisp_cons));
+	memset(ao_lisp_cons_note, '\0', sizeof (ao_lisp_cons_note));
 	ao_lisp_cons_noted = 0;
-	DBG("mark\n");
+	MDBG("mark\n");
 	for (i = 0; i < AO_LISP_ROOT; i++) {
 		if (ao_lisp_root[i].type) {
 			void **a = ao_lisp_root[i].addr, *v;
 			if (a && (v = *a)) {
-				DBG("root %d\n", DBG_OFFSET(v));
+				MDBG("root %d\n", MDBG_OFFSET(v));
 				ao_lisp_mark(ao_lisp_root[i].type, v);
 			}
 		} else {
 			ao_poly *a = (ao_poly *) ao_lisp_root[i].addr, p;
 			if (a && (p = *a)) {
-				DBG("root 0x%04x\n", p);
+				MDBG("root 0x%04x\n", p);
 				ao_lisp_poly_mark(p, 0);
 			}
 		}
 	}
 	while (ao_lisp_cons_noted) {
-		memcpy(ao_lisp_cons_last, ao_lisp_cons, sizeof (ao_lisp_cons));
-		memset(ao_lisp_cons, '\0', sizeof (ao_lisp_cons));
+		memcpy(ao_lisp_cons_last, ao_lisp_cons_note, sizeof (ao_lisp_cons_note));
+		memset(ao_lisp_cons_note, '\0', sizeof (ao_lisp_cons_note));
 		ao_lisp_cons_noted = 0;
 		for (i = 0; i < AO_LISP_POOL; i += 4) {
 			if (busy(ao_lisp_cons_last, i)) {
 				void *v = ao_lisp_pool + i;
-				DBG("cons %d\n", DBG_OFFSET(v));
+				MDBG("cons %d\n", MDBG_OFFSET(v));
 				ao_lisp_mark(&ao_lisp_cons_type, v);
 			}
 		}
@@ -310,13 +313,13 @@ ao_lisp_collect(void)
 	int	i;
 	int	top;
 
-	DBG("collect\n");
+	MDBG("collect\n");
 	/* Mark */
 	ao_lisp_mark_busy();
 
 	DUMP_BUSY();
 	/* Compact */
-	DBG("find first busy\n");
+	MDBG("find first busy\n");
 	for (i = 0; i < ao_lisp_top; i += 4) {
 		if (!busy(ao_lisp_busy, i))
 			break;
@@ -324,23 +327,25 @@ ao_lisp_collect(void)
 	top = i;
 	while(i < ao_lisp_top) {
 		if (busy(ao_lisp_busy, i)) {
-			DBG("busy %d -> %d\n", i, top);
+			MDBG("busy %d -> %d\n", i, top);
 			move_old = &ao_lisp_pool[i];
 			move_new = &ao_lisp_pool[top];
 			move_size = 0;
 			move_object();
-			DBG("\tbusy size %d\n", move_size);
+			MDBG("\tbusy size %d\n", move_size);
 			if (move_size == 0)
 				ao_lisp_abort();
 			clear_object(ao_lisp_busy, move_old, move_size);
 			mark_object(ao_lisp_busy, move_new, move_size);
-			if (busy_object(ao_lisp_cons, move_old)) {
-				clear_object(ao_lisp_cons, move_old, move_size);
-				mark_object(ao_lisp_cons, move_new, move_size);
+			if (busy_object(ao_lisp_cons_note, move_old)) {
+				clear_object(ao_lisp_cons_note, move_old, move_size);
+				mark_object(ao_lisp_cons_note, move_new, move_size);
 			}
 			i += move_size;
 			top += move_size;
+#if MDBG_MOVE
 			DUMP_BUSY();
+#endif
 		} else {
 			i += 4;
 		}
@@ -404,9 +409,9 @@ static void *
 check_move(void *addr, int size)
 {
 	if (addr == move_old) {
-		DBG_MOVE("mapping %d -> %d\n", DBG_OFFSET(addr), DBG_OFFSET(move_new));
+		MDBG_MOVE("mapping %d -> %d\n", MDBG_OFFSET(addr), MDBG_OFFSET(move_new));
 		if (!busy_object(ao_lisp_moving, addr)) {
-			DBG_MOVE("  copy %d\n", size);
+			MDBG_MOVE("  copy %d\n", size);
 			memmove(move_new, move_old, size);
 			move_size = (size + 3) & ~3;
 		}
@@ -429,24 +434,24 @@ ao_lisp_move(const struct ao_lisp_type *type, void **ref)
 	if (AO_LISP_IS_CONST(addr))
 		return 1;
 #endif
-	DBG_MOVE("object %d\n", DBG_OFFSET(addr));
+	MDBG_MOVE("object %d\n", MDBG_OFFSET(addr));
 	if (!AO_LISP_IS_POOL(a))
 		ao_lisp_abort();
-	DBG_MOVE_IN();
+	MDBG_MOVE_IN();
 	addr = check_move(addr, size);
 	if (addr != *ref)
 		*ref = addr;
 	if (mark_object(ao_lisp_moving, addr, size)) {
-		DBG_MOVE("already moved\n");
-		DBG_MOVE_OUT();
+		MDBG_MOVE("already moved\n");
+		MDBG_MOVE_OUT();
 		return 1;
 	}
-	DBG_MOVE_OUT();
-	DBG_MOVE("recursing...\n");
-	DBG_MOVE_IN();
+	MDBG_MOVE_OUT();
+	MDBG_MOVE("recursing...\n");
+	MDBG_MOVE_IN();
 	type->move(addr);
-	DBG_MOVE_OUT();
-	DBG_MOVE("done %d\n", DBG_OFFSET(addr));
+	MDBG_MOVE_OUT();
+	MDBG_MOVE("done %d\n", MDBG_OFFSET(addr));
 	return 0;
 }
 
@@ -457,17 +462,17 @@ ao_lisp_move_memory(void **ref, int size)
 	if (!addr)
 		return 1;
 
-	DBG_MOVE("memory %d\n", DBG_OFFSET(addr));
-	DBG_MOVE_IN();
+	MDBG_MOVE("memory %d\n", MDBG_OFFSET(addr));
+	MDBG_MOVE_IN();
 	addr = check_move(addr, size);
 	if (addr != *ref)
 		*ref = addr;
 	if (mark_object(ao_lisp_moving, addr, size)) {
-		DBG_MOVE("already moved\n");
-		DBG_MOVE_OUT();
+		MDBG_MOVE("already moved\n");
+		MDBG_MOVE_OUT();
 		return 1;
 	}
-	DBG_MOVE_OUT();
+	MDBG_MOVE_OUT();
 	return 0;
 }
 
@@ -505,14 +510,14 @@ ao_lisp_poly_move(ao_poly *ref, uint8_t do_note_cons)
 
 	if (addr != ao_lisp_ref(p)) {
 		ao_poly np = ao_lisp_poly(addr, p & AO_LISP_TYPE_MASK);
-		DBG("poly %d moved %04x -> %04x\n",
+		MDBG("poly %d moved %04x -> %04x\n",
 		    type, p, np);
 		*ref = np;
 	}
 	return ret;
 }
 
-#ifdef DBG_POOL
+#ifdef MDBG_POOL
 static int AO_LISP_POOL_CUR = AO_LISP_POOL / 8;
 
 static void
@@ -557,18 +562,18 @@ ao_lisp_alloc(int size)
 	void	*addr;
 
 	size = ao_lisp_mem_round(size);
-#ifdef DBG_COLLECT_ALWAYS
+#ifdef MDBG_COLLECT_ALWAYS
 	ao_lisp_collect();
 #endif
 	if (ao_lisp_top + size > AO_LISP_POOL_CUR) {
-#ifdef DBG_POOL
+#ifdef MDBG_POOL
 		if (AO_LISP_POOL_CUR < AO_LISP_POOL) {
 			AO_LISP_POOL_CUR += AO_LISP_POOL / 8;
 			ao_lisp_poison();
 		} else
 #endif
 		ao_lisp_collect();
-#ifdef DBG_POOL
+#ifdef MDBG_POOL
 		{
 			int	i;
 
@@ -580,7 +585,7 @@ ao_lisp_alloc(int size)
 #endif
 
 		if (ao_lisp_top + size > AO_LISP_POOL) {
-			ao_lisp_exception |= AO_LISP_OOM;
+			ao_lisp_error(AO_LISP_OOM, "out of memory");
 			return NULL;
 		}
 	}
@@ -593,7 +598,7 @@ int
 ao_lisp_root_add(const struct ao_lisp_type *type, void *addr)
 {
 	int	i;
-	DBG("add root type %p addr %p\n", type, addr);
+	MDBG("add root type %p addr %p\n", type, addr);
 	for (i = 0; i < AO_LISP_ROOT; i++) {
 		if (!ao_lisp_root[i].addr) {
 			ao_lisp_root[i].addr = addr;