1 files changed, 293 insertions, 0 deletions
diff --git a/src/lisp/ao_lisp_frame.c b/src/lisp/ao_lisp_frame.c
new file mode 100644
index 00000000..05f6d253
--- /dev/null
+++ b/src/lisp/ao_lisp_frame.c
@@ -0,0 +1,293 @@
+/*
+ * Copyright © 2016 Keith Packard <keithp@keithp.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.
+ */
+
+#include "ao_lisp.h"
+
+static inline int
+frame_num_size(int num)
+{
+	return sizeof (struct ao_lisp_frame) + num * sizeof (struct ao_lisp_val);
+}
+
+static int
+frame_size(void *addr)
+{
+	struct ao_lisp_frame	*frame = addr;
+	return frame_num_size(frame->num);
+}
+
+static void
+frame_mark(void *addr)
+{
+	struct ao_lisp_frame	*frame = addr;
+	int			f;
+
+	for (;;) {
+		MDBG_MOVE("frame mark %d\n", MDBG_OFFSET(frame));
+		if (!AO_LISP_IS_POOL(frame))
+			break;
+		for (f = 0; f < frame->num; f++) {
+			struct ao_lisp_val	*v = &frame->vals[f];
+
+			ao_lisp_poly_mark(v->val, 0);
+			MDBG_MOVE("frame mark atom %s %d val %d at %d\n",
+				  ao_lisp_poly_atom(v->atom)->name,
+				  MDBG_OFFSET(ao_lisp_ref(v->atom)),
+				  MDBG_OFFSET(ao_lisp_ref(v->val)), f);
+		}
+		frame = ao_lisp_poly_frame(frame->prev);
+		MDBG_MOVE("frame next %d\n", MDBG_OFFSET(frame));
+		if (!frame)
+			break;
+		if (ao_lisp_mark_memory(&ao_lisp_frame_type, frame))
+			break;
+	}
+}
+
+static void
+frame_move(void *addr)
+{
+	struct ao_lisp_frame	*frame = addr;
+	int			f;
+
+	for (;;) {
+		struct ao_lisp_frame	*prev;
+		int			ret;
+
+		MDBG_MOVE("frame move %d\n", MDBG_OFFSET(frame));
+		if (!AO_LISP_IS_POOL(frame))
+			break;
+		for (f = 0; f < frame->num; f++) {
+			struct ao_lisp_val	*v = &frame->vals[f];
+
+			ao_lisp_poly_move(&v->atom, 0);
+			ao_lisp_poly_move(&v->val, 0);
+			MDBG_MOVE("frame move atom %s %d val %d at %d\n",
+				  ao_lisp_poly_atom(v->atom)->name,
+				  MDBG_OFFSET(ao_lisp_ref(v->atom)),
+				  MDBG_OFFSET(ao_lisp_ref(v->val)), f);
+		}
+		prev = ao_lisp_poly_frame(frame->prev);
+		if (!prev)
+			break;
+		ret = ao_lisp_move_memory(&ao_lisp_frame_type, (void **) &prev);
+		if (prev != ao_lisp_poly_frame(frame->prev)) {
+			MDBG_MOVE("frame prev moved from %d to %d\n",
+				  MDBG_OFFSET(ao_lisp_poly_frame(frame->prev)),
+				  MDBG_OFFSET(prev));
+			frame->prev = ao_lisp_frame_poly(prev);
+		}
+		if (ret)
+			break;
+		frame = prev;
+	}
+}
+
+const struct ao_lisp_type ao_lisp_frame_type = {
+	.mark = frame_mark,
+	.size = frame_size,
+	.move = frame_move,
+	.name = "frame",
+};
+
+void
+ao_lisp_frame_print(ao_poly p)
+{
+	struct ao_lisp_frame	*frame = ao_lisp_poly_frame(p);
+	int			f;
+
+	printf ("{");
+	if (frame) {
+		if (frame->type & AO_LISP_FRAME_PRINT)
+			printf("recurse...");
+		else {
+			frame->type |= AO_LISP_FRAME_PRINT;
+			for (f = 0; f < frame->num; f++) {
+				if (f != 0)
+					printf(", ");
+				ao_lisp_poly_print(frame->vals[f].atom);
+				printf(" = ");
+				ao_lisp_poly_print(frame->vals[f].val);
+			}
+			if (frame->prev)
+				ao_lisp_poly_print(frame->prev);
+			frame->type &= ~AO_LISP_FRAME_PRINT;
+		}
+	}
+	printf("}");
+}
+
+static int
+ao_lisp_frame_find(struct ao_lisp_frame *frame, int top, ao_poly atom)
+{
+	int l = 0;
+	int r = top - 1;
+	while (l <= r) {
+		int m = (l + r) >> 1;
+		if (frame->vals[m].atom < atom)
+			l = m + 1;
+		else
+			r = m - 1;
+	}
+	return l;
+}
+
+ao_poly *
+ao_lisp_frame_ref(struct ao_lisp_frame *frame, ao_poly atom)
+{
+	int l = ao_lisp_frame_find(frame, frame->num, atom);
+
+	if (l >= frame->num)
+		return NULL;
+
+	if (frame->vals[l].atom != atom)
+		return NULL;
+	return &frame->vals[l].val;
+}
+
+int
+ao_lisp_frame_set(struct ao_lisp_frame *frame, ao_poly atom, ao_poly val)
+{
+	while (frame) {
+		if (!AO_LISP_IS_CONST(frame)) {
+			ao_poly *ref = ao_lisp_frame_ref(frame, atom);
+			if (ref) {
+				*ref = val;
+				return 1;
+			}
+		}
+		frame = ao_lisp_poly_frame(frame->prev);
+	}
+	return 0;
+}
+
+ao_poly
+ao_lisp_frame_get(struct ao_lisp_frame *frame, ao_poly atom)
+{
+	while (frame) {
+		ao_poly *ref = ao_lisp_frame_ref(frame, atom);
+		if (ref)
+			return *ref;
+		frame = ao_lisp_poly_frame(frame->prev);
+	}
+	return AO_LISP_NIL;
+}
+
+struct ao_lisp_frame	*ao_lisp_frame_free_list[AO_LISP_FRAME_FREE];
+
+struct ao_lisp_frame *
+ao_lisp_frame_new(int num)
+{
+	struct ao_lisp_frame	*frame;
+
+	if (num < AO_LISP_FRAME_FREE && (frame = ao_lisp_frame_free_list[num]))
+		ao_lisp_frame_free_list[num] = ao_lisp_poly_frame(frame->prev);
+	else {
+		frame = ao_lisp_alloc(frame_num_size(num));
+		if (!frame)
+			return NULL;
+	}
+	frame->type = AO_LISP_FRAME;
+	frame->num = num;
+	frame->prev = AO_LISP_NIL;
+	memset(frame->vals, '\0', num * sizeof (struct ao_lisp_val));
+	return frame;
+}
+
+ao_poly
+ao_lisp_frame_mark(struct ao_lisp_frame *frame)
+{
+	if (!frame)
+		return AO_LISP_NIL;
+	frame->type |= AO_LISP_FRAME_MARK;
+	return ao_lisp_frame_poly(frame);
+}
+
+void
+ao_lisp_frame_free(struct ao_lisp_frame *frame)
+{
+	if (!ao_lisp_frame_marked(frame)) {
+		int	num = frame->num;
+		if (num < AO_LISP_FRAME_FREE) {
+			frame->prev = ao_lisp_frame_poly(ao_lisp_frame_free_list[num]);
+			ao_lisp_frame_free_list[num] = frame;
+		}
+	}
+}
+
+static struct ao_lisp_frame *
+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;
+
+	if (new_num == frame->num)
+		return frame;
+	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));
+	new->prev = frame->prev;
+	ao_lisp_frame_free(frame);
+	return new;
+}
+
+void
+ao_lisp_frame_bind(struct ao_lisp_frame *frame, int num, ao_poly atom, ao_poly val)
+{
+	int l = ao_lisp_frame_find(frame, num, atom);
+
+	memmove(&frame->vals[l+1],
+		&frame->vals[l],
+		(num - l) * sizeof (struct ao_lisp_val));
+	frame->vals[l].atom = atom;
+	frame->vals[l].val = 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_poly_stash(0, atom);
+		ao_lisp_poly_stash(1, val);
+		if (frame) {
+			f = frame->num;
+			frame = ao_lisp_frame_realloc(frame_ref, f + 1);
+		} else {
+			f = 0;
+			frame = ao_lisp_frame_new(1);
+		}
+		if (!frame)
+			return 0;
+		*frame_ref = frame;
+		atom = ao_lisp_poly_fetch(0);
+		val = ao_lisp_poly_fetch(1);
+		ao_lisp_frame_bind(frame, frame->num - 1, atom, val);
+	} else
+		*ref = val;
+	return 1;
+}