From 17face3633686e374aa0859271ccf462a48e60aa Mon Sep 17 00:00:00 2001
From: Rose Hogenson <rosehogenson@posteo.net>
Date: Sun, 4 Feb 2024 16:46:20 -0800
Subject: Rewrite the bytecode interpreter in Rust.

---
 bytecode/heap.c | 125 --------------------------------------------------------
 1 file changed, 125 deletions(-)
 delete mode 100644 bytecode/heap.c

(limited to 'bytecode/heap.c')

diff --git a/bytecode/heap.c b/bytecode/heap.c
deleted file mode 100644
index 1ba5faf..0000000
--- a/bytecode/heap.c
+++ /dev/null
@@ -1,125 +0,0 @@
-#include <stdint.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include "encoding.h"
-#include "heap.h"
-#include "panic.h"
-#include "value.h"
-#include "value_slice.h"
-
-struct heap new_heap(value_slice gc_roots)
-{
-	return (struct heap) {
-		.buf = NULL,
-		.active = { .size = 0 },
-		.standby = { .size = 0 },
-		.free_ptr = 0,
-		.last_free = 0,
-		.gc_roots = gc_roots,
-	};
-}
-
-static bool forwarded(struct heap *h, value *p)
-{
-	if (!is_pointer(*p)) {
-		return false;
-	}
-	value *q = to_pointer(*p);
-	return h->active.buf <= q && q <= h->active.buf + h->active.size;
-}
-
-static size_t alloc_size(value *p)
-{
-	return p[-1] >> 1;
-}
-
-static value *simple_alloc(struct heap *h, int64_t size)
-{
-	h->active.buf[h->free_ptr] = size << 1;
-	value *p = h->active.buf + h->free_ptr + 1;
-	h->free_ptr += size;
-	return p;
-}
-
-static value process_gc_value(struct heap *h, value val)
-{
-	if (!is_pointer(val)) {
-		return val;
-	}
-	value *p = to_pointer(val);
-	if (forwarded(h, p)) {
-		return *p;
-	}
-
-	size_t size = alloc_size(p);
-
-	// Allocate space in the new buffer.
-	value *q = simple_alloc(h, size);
-
-	// Write forwarding pointer.
-	value first_value = p[0];
-	p[0] = from_pointer(q);
-
-	// Copy values, recursively modifying pointers.
-	q[0] = process_gc_value(h, first_value);
-	for (size_t i = 1; i < size; i++) {
-		q[i] = process_gc_value(h, p[i]);
-	}
-
-	return from_pointer(q);
-}
-
-static void collect_garbage(struct heap *h)
-{
-	if (h->free_ptr < 2 * h->last_free) {
-		return;
-	}
-
-	// Swap the heaps.
-	value_slice temp = h->active;
-	h->active = h->standby;
-	h->standby = temp;
-
-	h->free_ptr = 0;
-
-	for (size_t i = 0; i < h->gc_roots.size; i++ ) {
-		h->gc_roots.buf[i] = process_gc_value(h, h->gc_roots.buf[i]);
-	}
-}
-
-static value_slice xcalloc(size_t size)
-{
-	value *p = calloc(size, sizeof(value));
-	if (!p) {
-		panicf("Out of memory!\n");
-	}
-	return (value_slice) { .size = size, .buf = p };
-}
-
-static void more_space(struct heap *h, int64_t size_hint)
-{
-	size_t new_size = h->active.size * 2 + size_hint;
-	value_slice new_buf = xcalloc(2 * new_size);
-	memcpy(new_buf.buf, h->active.buf, h->active.size * sizeof(value));
-
-	free(h->buf);
-	h->buf = new_buf.buf;
-	h->active = value_slice2(new_buf, 0, new_size);
-	h->standby = value_slice1(new_buf, new_size);
-}
-
-value *alloc(struct heap *h, int64_t size)
-{
-	if (size <= 0) {
-		panicf("Alloc of zero size!\n");
-	}
-	collect_garbage(h);
-
-	if (h->free_ptr + size >= h->active.size) {
-		more_space(h, size);
-	}
-	value *p = simple_alloc(h, size);
-	memset(p, 0, size * sizeof(value));
-	return p;
-}
-- 
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