C++ DUK_DD函数代码示例

DUK_LOCAL void duk__mark_finalizable(duk_heap *heap) {
	duk_hthread *thr;
	duk_heaphdr *hdr;
	duk_size_t count_finalizable = 0;

	DUK_DD(DUK_DDPRINT("duk__mark_finalizable: %p", (void *) heap));

	thr = duk__get_temp_hthread(heap);
	DUK_ASSERT(thr != NULL);

	hdr = heap->heap_allocated;
	while (hdr) {
		/* A finalizer is looked up from the object and up its prototype chain
		 * (which allows inherited finalizers).  A prototype loop must not cause
		 * an error to be thrown here; duk_hobject_hasprop_raw() will ignore a
		 * prototype loop silently and indicate that the property doesn't exist.
		 */

		if (!DUK_HEAPHDR_HAS_REACHABLE(hdr) &&
		    DUK_HEAPHDR_GET_TYPE(hdr) == DUK_HTYPE_OBJECT &&
		    !DUK_HEAPHDR_HAS_FINALIZED(hdr) &&
		    duk_hobject_hasprop_raw(thr, (duk_hobject *) hdr, DUK_HTHREAD_STRING_INT_FINALIZER(thr))) {

			/* heaphdr:
			 *  - is not reachable
			 *  - is an object
			 *  - is not a finalized object
			 *  - has a finalizer
			 */

			DUK_DD(DUK_DDPRINT("unreachable heap object will be "
			                   "finalized -> mark as finalizable "
			                   "and treat as a reachability root: %p",
			                   (void *) hdr));
			DUK_ASSERT(!DUK_HEAPHDR_HAS_READONLY(hdr));
			DUK_HEAPHDR_SET_FINALIZABLE(hdr);
			count_finalizable ++;
		}

		hdr = DUK_HEAPHDR_GET_NEXT(heap, hdr);
	}

	if (count_finalizable == 0) {
		return;
	}

	DUK_DD(DUK_DDPRINT("marked %ld heap objects as finalizable, now mark them reachable",
	                   (long) count_finalizable));

	hdr = heap->heap_allocated;
	while (hdr) {
		if (DUK_HEAPHDR_HAS_FINALIZABLE(hdr)) {
			duk__mark_heaphdr(heap, hdr);
		}

		hdr = DUK_HEAPHDR_GET_NEXT(heap, hdr);
	}

	/* Caller will finish the marking process if we hit a recursion limit. */
}

DUK_INTERNAL void duk_heap_switch_thread(duk_heap *heap, duk_hthread *new_thr) {
	duk_hthread *curr_thr;

	DUK_ASSERT(heap != NULL);

	if (new_thr != NULL) {
		curr_thr = heap->curr_thread;
		if (curr_thr == NULL) {
			/* For initial entry use default value; zero forces an
			 * interrupt before executing the first insturction.
			 */
			DUK_DD(DUK_DDPRINT("switch thread, initial entry, init default interrupt counter"));
			new_thr->interrupt_counter = 0;
			new_thr->interrupt_init = 0;
		} else {
			/* Copy interrupt counter/init value state to new thread (if any).
			 * It's OK for new_thr to be the same as curr_thr.
			 */
#if defined(DUK_USE_DEBUG)
			if (new_thr != curr_thr) {
				DUK_DD(DUK_DDPRINT("switch thread, not initial entry, copy interrupt counter"));
			}
#endif
			new_thr->interrupt_counter = curr_thr->interrupt_counter;
			new_thr->interrupt_init = curr_thr->interrupt_init;
		}
	} else {
		DUK_DD(DUK_DDPRINT("switch thread, new thread is NULL, no interrupt counter changes"));
	}

	heap->curr_thread = new_thr;  /* may be NULL */
}

static void duk__mark_finalizable(duk_heap *heap) {
	duk_hthread *thr;
	duk_heaphdr *hdr;
	int count_finalizable = 0;

	DUK_DD(DUK_DDPRINT("duk__mark_finalizable: %p", (void *) heap));

	thr = duk__get_temp_hthread(heap);
	DUK_ASSERT(thr != NULL);

	hdr = heap->heap_allocated;
	while (hdr) {
		/* A finalizer is looked up from the object and up its prototype chain
		 * (which allows inherited finalizers).
		 */
		if (!DUK_HEAPHDR_HAS_REACHABLE(hdr) &&
		    DUK_HEAPHDR_GET_TYPE(hdr) == DUK_HTYPE_OBJECT &&
		    !DUK_HEAPHDR_HAS_FINALIZED(hdr) &&
		    duk_hobject_hasprop_raw(thr, (duk_hobject *) hdr, DUK_HTHREAD_STRING_INT_FINALIZER(thr))) {

			/* heaphdr:
			 *  - is not reachable
			 *  - is an object
			 *  - is not a finalized object
			 *  - has a finalizer
			 */

			DUK_DD(DUK_DDPRINT("unreachable heap object will be finalized -> mark as finalizable and treat as a reachability root: %p", hdr));
			DUK_HEAPHDR_SET_FINALIZABLE(hdr);
			count_finalizable ++;
		}

		hdr = DUK_HEAPHDR_GET_NEXT(hdr);
	}

	if (count_finalizable == 0) {
		return;
	}

	DUK_DD(DUK_DDPRINT("marked %d heap objects as finalizable, now mark them reachable", count_finalizable));

	hdr = heap->heap_allocated;
	while (hdr) {
		if (DUK_HEAPHDR_HAS_FINALIZABLE(hdr)) {
			duk__mark_heaphdr(heap, hdr);
		}

		hdr = DUK_HEAPHDR_GET_NEXT(hdr);
	}

	/* Caller will finish the marking process if we hit a recursion limit. */
}

DUK_LOCAL void duk__generate_ranges(void *userdata, duk_codepoint_t r1, duk_codepoint_t r2, duk_bool_t direct) {
    duk_re_compiler_ctx *re_ctx = (duk_re_compiler_ctx *) userdata;

    DUK_DD(DUK_DDPRINT("duk__generate_ranges(): re_ctx=%p, range=[%ld,%ld] direct=%ld",
                       (void *) re_ctx, (long) r1, (long) r2, (long) direct));

    if (!direct && (re_ctx->re_flags & DUK_RE_FLAG_IGNORE_CASE)) {
        /*
         *  Canonicalize a range, generating result ranges as necessary.
         *  Needs to exhaustively scan the entire range (at most 65536
         *  code points).  If 'direct' is set, caller (lexer) has ensured
         *  that the range is already canonicalization compatible (this
         *  is used to avoid unnecessary canonicalization of built-in
         *  ranges like \W, which are not affected by canonicalization).
         *
         *  NOTE: here is one place where we don't want to support chars
         *  outside the BMP, because the exhaustive search would be
         *  massively larger.
         */

        duk_codepoint_t i;
        duk_codepoint_t t;
        duk_codepoint_t r_start, r_end;

        r_start = duk_unicode_re_canonicalize_char(re_ctx->thr, r1);
        r_end = r_start;
        for (i = r1 + 1; i <= r2; i++) {
            t = duk_unicode_re_canonicalize_char(re_ctx->thr, i);
            if (t == r_end + 1) {
                r_end = t;
            } else {
                DUK_DD(DUK_DDPRINT("canonicalized, emit range: [%ld,%ld]", (long) r_start, (long) r_end));
                duk__append_u32(re_ctx, (duk_uint32_t) r_start);
                duk__append_u32(re_ctx, (duk_uint32_t) r_end);
                re_ctx->nranges++;
                r_start = t;
                r_end = t;
            }
        }
        DUK_DD(DUK_DDPRINT("canonicalized, emit range: [%ld,%ld]", (long) r_start, (long) r_end));
        duk__append_u32(re_ctx, (duk_uint32_t) r_start);
        duk__append_u32(re_ctx, (duk_uint32_t) r_end);
        re_ctx->nranges++;
    } else {
        DUK_DD(DUK_DDPRINT("direct, emit range: [%ld,%ld]", (long) r1, (long) r2));
        duk__append_u32(re_ctx, (duk_uint32_t) r1);
        duk__append_u32(re_ctx, (duk_uint32_t) r2);
        re_ctx->nranges++;
    }
}

DUK_LOCAL void duk__finalize_refcounts(duk_heap *heap) {
	duk_hthread *thr;
	duk_heaphdr *hdr;

	thr = duk__get_temp_hthread(heap);
	DUK_ASSERT(thr != NULL);

	DUK_DD(DUK_DDPRINT("duk__finalize_refcounts: heap=%p, hthread=%p",
	                   (void *) heap, (void *) thr));

	hdr = heap->heap_allocated;
	while (hdr) {
		if (!DUK_HEAPHDR_HAS_REACHABLE(hdr)) {
			/*
			 *  Unreachable object about to be swept.  Finalize target refcounts
			 *  (objects which the unreachable object points to) without doing
			 *  refzero processing.  Recursive decrefs are also prevented when
			 *  refzero processing is disabled.
			 *
			 *  Value cannot be a finalizable object, as they have been made
			 *  temporarily reachable for this round.
			 */

			DUK_DDD(DUK_DDDPRINT("unreachable object, refcount finalize before sweeping: %p", (void *) hdr));
			duk_heaphdr_refcount_finalize(thr, hdr);
		}

		hdr = DUK_HEAPHDR_GET_NEXT(heap, hdr);
	}
}

DUK_LOCAL void duk__compact_objects(duk_heap *heap) {
	/* XXX: which lists should participate?  to be finalized? */
#if defined(DUK_USE_DEBUG)
	duk_size_t count_check = 0;
	duk_size_t count_compact = 0;
	duk_size_t count_bytes_saved = 0;
#endif
	duk_hthread *thr;

	DUK_DD(DUK_DDPRINT("duk__compact_objects: %p", (void *) heap));

	thr = duk__get_temp_hthread(heap);
	DUK_ASSERT(thr != NULL);

#if defined(DUK_USE_DEBUG)
	duk__compact_object_list(heap, thr, heap->heap_allocated, &count_check, &count_compact, &count_bytes_saved);
	duk__compact_object_list(heap, thr, heap->finalize_list, &count_check, &count_compact, &count_bytes_saved);
#if defined(DUK_USE_REFERENCE_COUNTING)
	duk__compact_object_list(heap, thr, heap->refzero_list, &count_check, &count_compact, &count_bytes_saved);
#endif
#else
	duk__compact_object_list(heap, thr, heap->heap_allocated);
	duk__compact_object_list(heap, thr, heap->finalize_list);
#if defined(DUK_USE_REFERENCE_COUNTING)
	duk__compact_object_list(heap, thr, heap->refzero_list);
#endif
#endif

#if defined(DUK_USE_DEBUG)
	DUK_D(DUK_DPRINT("mark-and-sweep compact objects: %ld checked, %ld compaction attempts, %ld bytes saved by compaction",
	                 (long) count_check, (long) count_compact, (long) count_bytes_saved));
#endif
}

static int duk__init_heap_thread(duk_heap *heap) {
	duk_hthread *thr;
	
	DUK_DD(DUK_DDPRINT("heap init: alloc heap thread"));
	thr = duk_hthread_alloc(heap,
	                        DUK_HOBJECT_FLAG_EXTENSIBLE |
	                        DUK_HOBJECT_FLAG_THREAD |
	                        DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_THREAD));
	if (!thr) {
		DUK_D(DUK_DPRINT("failed to alloc heap_thread"));
		return 0;
	}
	thr->state = DUK_HTHREAD_STATE_INACTIVE;
	thr->strs = heap->strs;

	heap->heap_thread = thr;
	DUK_HTHREAD_INCREF(thr, thr);  /* Note: first argument not really used */

	/* 'thr' is now reachable */

	if (!duk_hthread_init_stacks(heap, thr)) {
		return 0;
	}

	/* FIXME: this may now fail, and is not handled correctly */
	duk_hthread_create_builtin_objects(thr);

	/* default prototype (Note: 'thr' must be reachable) */
	DUK_HOBJECT_SET_PROTOTYPE_UPDREF(thr, (duk_hobject *) thr, thr->builtins[DUK_BIDX_THREAD_PROTOTYPE]);

	return 1;
}

void duk_hthread_callstack_shrink_check(duk_hthread *thr) {
	duk_size_t new_size;
	duk_activation *p;

	DUK_ASSERT(thr != NULL);
	DUK_ASSERT_DISABLE(thr->callstack_top >= 0);  /* avoid warning (unsigned) */
	DUK_ASSERT(thr->callstack_size >= thr->callstack_top);

	if (thr->callstack_size - thr->callstack_top < DUK_CALLSTACK_SHRINK_THRESHOLD) {
		return;
	}

	new_size = thr->callstack_top + DUK_CALLSTACK_SHRINK_SPARE;
	DUK_ASSERT(new_size >= thr->callstack_top);

	DUK_DD(DUK_DDPRINT("shrinking callstack %d -> %d", thr->callstack_size, new_size));

	/*
	 *  Note: must use indirect variant of DUK_REALLOC() because underlying
	 *  pointer may be changed by mark-and-sweep.
	 */

	/* shrink failure is not fatal */
	p = (duk_activation *) DUK_REALLOC_INDIRECT(thr->heap, duk_hthread_get_callstack_ptr, (void *) thr, sizeof(duk_activation) * new_size);
	if (p) {
		thr->callstack = p;
		thr->callstack_size = new_size;
	} else {
		DUK_D(DUK_DPRINT("callstack shrink failed, ignoring"));
	}

	/* note: any entries above the callstack top are garbage and not zeroed */
}

void duk_hthread_catchstack_grow(duk_hthread *thr) {
	duk_size_t old_size;
	duk_size_t new_size;

	DUK_ASSERT(thr != NULL);
	DUK_ASSERT_DISABLE(thr->catchstack_top);  /* avoid warning (unsigned) */
	DUK_ASSERT(thr->catchstack_size >= thr->catchstack_top);

	if (thr->catchstack_top < thr->catchstack_size) {
		return;
	}

	old_size = thr->catchstack_size;
	new_size = old_size + DUK_CATCHSTACK_GROW_STEP;

	/* this is a bit approximate (errors out before max is reached); this is OK */
	if (new_size >= thr->catchstack_max) {
		DUK_ERROR(thr, DUK_ERR_RANGE_ERROR, "catchstack limit");
	}

	DUK_DD(DUK_DDPRINT("growing catchstack %d -> %d", old_size, new_size));

	/*
	 *  Note: must use indirect variant of DUK_REALLOC() because underlying
	 *  pointer may be changed by mark-and-sweep.
	 */

	thr->catchstack = (duk_catcher *) DUK_REALLOC_INDIRECT_CHECKED(thr, duk_hthread_get_catchstack_ptr, (void *) thr, sizeof(duk_catcher) * new_size);
	thr->catchstack_size = new_size;

	/* note: any entries above the catchstack top are garbage and not zeroed */
}

DUK_EXTERNAL void duk_dump_function(duk_context *ctx) {
	duk_hthread *thr;
	duk_hcompiledfunction *func;
	duk_bufwriter_ctx bw_ctx_alloc;
	duk_bufwriter_ctx *bw_ctx = &bw_ctx_alloc;
	duk_uint8_t *p;

	DUK_ASSERT(ctx != NULL);
	thr = (duk_hthread *) ctx;

	/* Bound functions don't have all properties so we'd either need to
	 * lookup the non-bound target function or reject bound functions.
	 * For now, bound functions are rejected.
	 */
	func = duk_require_hcompiledfunction(ctx, -1);
	DUK_ASSERT(func != NULL);
	DUK_ASSERT(!DUK_HOBJECT_HAS_BOUND(&func->obj));

	/* Estimating the result size beforehand would be costly, so
	 * start with a reasonable size and extend as needed.
	 */
	DUK_BW_INIT_PUSHBUF(thr, bw_ctx, DUK__BYTECODE_INITIAL_ALLOC);
	p = DUK_BW_GET_PTR(thr, bw_ctx);
	*p++ = DUK__SER_MARKER;
	*p++ = DUK__SER_VERSION;
	p = duk__dump_func(ctx, func, bw_ctx, p);
	DUK_BW_SET_PTR(thr, bw_ctx, p);
	DUK_BW_COMPACT(thr, bw_ctx);

	DUK_DD(DUK_DDPRINT("serialized result: %!T", duk_get_tval(ctx, -1)));

	duk_remove(ctx, -2);  /* [ ... func buf ] -> [ ... buf ] */
}

DUK_LOCAL duk_ret_t duk__error_setter_helper(duk_context *ctx, duk_small_uint_t stridx_key) {
	/* Attempt to write 'stack', 'fileName', 'lineNumber' works as if
	 * user code called Object.defineProperty() to create an overriding
	 * own property.  This allows user code to overwrite .fileName etc
	 * intuitively as e.g. "err.fileName = 'dummy'" as one might expect.
	 * See https://github.com/svaarala/duktape/issues/387.
	 */

	DUK_ASSERT_TOP(ctx, 1);  /* fixed arg count: value */

	duk_push_this(ctx);
	duk_push_hstring_stridx(ctx, (duk_small_int_t) stridx_key);
	duk_dup_0(ctx);

	/* [ ... obj key value ] */

	DUK_DD(DUK_DDPRINT("error setter: %!T %!T %!T",
	                   duk_get_tval(ctx, -3), duk_get_tval(ctx, -2), duk_get_tval(ctx, -1)));

	duk_def_prop(ctx, -3, DUK_DEFPROP_HAVE_VALUE |
	                      DUK_DEFPROP_HAVE_WRITABLE | DUK_DEFPROP_WRITABLE |
	                      DUK_DEFPROP_HAVE_ENUMERABLE | /*not enumerable*/
	                      DUK_DEFPROP_HAVE_CONFIGURABLE | DUK_DEFPROP_CONFIGURABLE);
	return 0;
}

static void duk__sweep_stringtable(duk_heap *heap, duk_size_t *out_count_keep) {
	duk_hstring *h;
	duk_uint_fast32_t i;
#ifdef DUK_USE_DEBUG
	duk_size_t count_free = 0;
#endif
	duk_size_t count_keep = 0;

	DUK_DD(DUK_DDPRINT("duk__sweep_stringtable: %p", (void *) heap));

	for (i = 0; i < heap->st_size; i++) {
		h = heap->st[i];
		if (h == NULL || h == DUK_STRTAB_DELETED_MARKER(heap)) {
			continue;
		} else if (DUK_HEAPHDR_HAS_REACHABLE((duk_heaphdr *) h)) {
			DUK_HEAPHDR_CLEAR_REACHABLE((duk_heaphdr *) h);
			count_keep++;
			continue;
		}

#ifdef DUK_USE_DEBUG
		count_free++;
#endif

#if defined(DUK_USE_REFERENCE_COUNTING)
		/* Non-zero refcounts should not happen for unreachable strings,
		 * because we refcount finalize all unreachable objects which
		 * should have decreased unreachable string refcounts to zero
		 * (even for cycles).
		 */
		DUK_ASSERT(DUK_HEAPHDR_GET_REFCOUNT((duk_heaphdr *) h) == 0);
#endif

		DUK_DDD(DUK_DDDPRINT("sweep string, not reachable: %p", (void *) h));

		/* deal with weak references first */
		duk_heap_strcache_string_remove(heap, (duk_hstring *) h);

		/* remove the string (mark DELETED), could also call
		 * duk_heap_string_remove() but that would be slow and
		 * pointless because we already know the slot.
		 */
		heap->st[i] = DUK_STRTAB_DELETED_MARKER(heap);

		/* then free */
#if 1
		DUK_FREE(heap, (duk_heaphdr *) h);  /* no inner refs/allocs, just free directly */
#else
		duk_heap_free_heaphdr_raw(heap, (duk_heaphdr *) h);  /* this would be OK but unnecessary */
#endif
	}

#ifdef DUK_USE_DEBUG
	DUK_D(DUK_DPRINT("mark-and-sweep sweep stringtable: %d freed, %d kept",
	                 (int) count_free, (int) count_keep));
#endif
	*out_count_keep = count_keep;
}

DUK_LOCAL void duk__run_object_finalizers(duk_heap *heap, duk_small_uint_t flags) {
	duk_heaphdr *curr;
	duk_heaphdr *next;
#if defined(DUK_USE_DEBUG)
	duk_size_t count = 0;
#endif
	duk_hthread *thr;

	DUK_DD(DUK_DDPRINT("duk__run_object_finalizers: %p", (void *) heap));

	thr = duk__get_temp_hthread(heap);
	DUK_ASSERT(thr != NULL);

	curr = heap->finalize_list;
	while (curr) {
		DUK_DDD(DUK_DDDPRINT("mark-and-sweep finalize: %p", (void *) curr));

		DUK_ASSERT(DUK_HEAPHDR_GET_TYPE(curr) == DUK_HTYPE_OBJECT);  /* only objects have finalizers */
		DUK_ASSERT(!DUK_HEAPHDR_HAS_REACHABLE(curr));                /* flags have been already cleared */
		DUK_ASSERT(!DUK_HEAPHDR_HAS_TEMPROOT(curr));
		DUK_ASSERT(!DUK_HEAPHDR_HAS_FINALIZABLE(curr));
		DUK_ASSERT(!DUK_HEAPHDR_HAS_FINALIZED(curr));
		DUK_ASSERT(!DUK_HEAPHDR_HAS_READONLY(curr));  /* No finalizers for ROM objects */

		if (DUK_LIKELY((flags & DUK_MS_FLAG_SKIP_FINALIZERS) == 0)) {
			/* Run the finalizer, duk_hobject_run_finalizer() sets FINALIZED.
			 * Next mark-and-sweep will collect the object unless it has
			 * become reachable (i.e. rescued).  FINALIZED prevents the
			 * finalizer from being executed again before that.
			 */
			duk_hobject_run_finalizer(thr, (duk_hobject *) curr);  /* must never longjmp */
			DUK_ASSERT(DUK_HEAPHDR_HAS_FINALIZED(curr));
		} else {
			/* Used during heap destruction: don't actually run finalizers
			 * because we're heading into forced finalization.  Instead,
			 * queue finalizable objects back to the heap_allocated list.
			 */
			DUK_D(DUK_DPRINT("skip finalizers flag set, queue object to heap_allocated without finalizing"));
			DUK_ASSERT(!DUK_HEAPHDR_HAS_FINALIZED(curr));
		}

		/* queue back to heap_allocated */
		next = DUK_HEAPHDR_GET_NEXT(heap, curr);
		DUK_HEAP_INSERT_INTO_HEAP_ALLOCATED(heap, curr);

		curr = next;
#if defined(DUK_USE_DEBUG)
		count++;
#endif
	}

	/* finalize_list will always be processed completely */
	heap->finalize_list = NULL;

#if defined(DUK_USE_DEBUG)
	DUK_D(DUK_DPRINT("mark-and-sweep finalize objects: %ld finalizers called", (long) count));
#endif
}

DUK_INTERNAL duk_ret_t duk_bi_object_constructor_seal_freeze_shared(duk_context *ctx) {
	duk_hthread *thr = (duk_hthread *) ctx;
	duk_hobject *h;
	duk_bool_t is_freeze;

	DUK_ASSERT_TOP(ctx, 1);

	is_freeze = (duk_bool_t) duk_get_current_magic(ctx);
	if (duk_is_buffer(ctx, 0)) {
		/* Plain buffer: already sealed, but not frozen (and can't be frozen
		 * because index properties can't be made non-writable.
		 */
		if (is_freeze) {
			goto fail_cannot_freeze;
		}
		return 1;
	} else if (duk_is_lightfunc(ctx, 0)) {
		/* Lightfunc: already sealed and frozen, success. */
		return 1;
	}
#if 0
	/* Seal/freeze are quite rare in practice so it'd be nice to get the
	 * correct behavior simply via automatic promotion (at the cost of some
	 * memory churn).  However, the promoted objects don't behave the same,
	 * e.g. promoted lightfuncs are extensible.
	 */
	h = duk_require_hobject_promote_mask(ctx, 0, DUK_TYPE_MASK_LIGHTFUNC | DUK_TYPE_MASK_BUFFER);
#endif

	h = duk_get_hobject(ctx, 0);
	if (h == NULL) {
		/* ES2015 Sections 19.1.2.5, 19.1.2.17 */
		return 1;
	}

	if (is_freeze && DUK_HOBJECT_IS_BUFOBJ(h)) {
		/* Buffer objects cannot be frozen because there's no internal
		 * support for making virtual array indices non-writable.
		 */
		DUK_DD(DUK_DDPRINT("cannot freeze a buffer object"));
		goto fail_cannot_freeze;
	}

	duk_hobject_object_seal_freeze_helper(thr, h, is_freeze);

	/* Sealed and frozen objects cannot gain any more properties,
	 * so this is a good time to compact them.
	 */
	duk_hobject_compact_props(thr, h);
	return 1;

 fail_cannot_freeze:
	DUK_DCERROR_TYPE_INVALID_ARGS(thr);  /* XXX: proper error message */
}

DUK_LOCAL void duk__mark_refzero_list(duk_heap *heap) {
	duk_heaphdr *hdr;

	DUK_DD(DUK_DDPRINT("duk__mark_refzero_list: %p", (void *) heap));

	hdr = heap->refzero_list;
	while (hdr) {
		duk__mark_heaphdr(heap, hdr);
		hdr = DUK_HEAPHDR_GET_NEXT(heap, hdr);
	}
}