Example #1
0
void duk_hobject_enumerator_create(duk_context *ctx, duk_small_uint_t enum_flags) {
	duk_hthread *thr = (duk_hthread *) ctx;
	duk_hobject *enum_target;
	duk_hobject *curr;
	duk_hobject *res;
#if defined(DUK_USE_ES6_PROXY)
	duk_hobject *h_proxy_target;
	duk_hobject *h_proxy_handler;
	duk_hobject *h_trap_result;
#endif
	duk_uint_fast32_t i, len;  /* used for array, stack, and entry indices */

	DUK_ASSERT(ctx != NULL);

	DUK_DDD(DUK_DDDPRINT("create enumerator, stack top: %ld", (long) duk_get_top(ctx)));

	enum_target = duk_require_hobject(ctx, -1);
	DUK_ASSERT(enum_target != NULL);

	duk_push_object_internal(ctx);
	res = duk_require_hobject(ctx, -1);

	DUK_DDD(DUK_DDDPRINT("created internal object"));

	/* [enum_target res] */

	/* Target must be stored so that we can recheck whether or not
	 * keys still exist when we enumerate.  This is not done if the
	 * enumeration result comes from a proxy trap as there is no
	 * real object to check against.
	 */
	duk_push_hobject(ctx, enum_target);
	duk_put_prop_stridx(ctx, -2, DUK_STRIDX_INT_TARGET);

	/* Initialize index so that we skip internal control keys. */
	duk_push_int(ctx, DUK__ENUM_START_INDEX);
	duk_put_prop_stridx(ctx, -2, DUK_STRIDX_INT_NEXT);

	/*
	 *  Proxy object handling
	 */

#if defined(DUK_USE_ES6_PROXY)
	if (DUK_LIKELY((enum_flags & DUK_ENUM_NO_PROXY_BEHAVIOR) != 0)) {
		goto skip_proxy;
	}
	if (DUK_LIKELY(!duk_hobject_proxy_check(thr,
	                                        enum_target,
	                                        &h_proxy_target,
	                                        &h_proxy_handler))) {
		goto skip_proxy;
	}

	DUK_DDD(DUK_DDDPRINT("proxy enumeration"));
	duk_push_hobject(ctx, h_proxy_handler);
	if (!duk_get_prop_stridx(ctx, -1, DUK_STRIDX_ENUMERATE)) {
		/* No need to replace the 'enum_target' value in stack, only the
		 * enum_target reference.  This also ensures that the original
		 * enum target is reachable, which keeps the proxy and the proxy
		 * target reachable.  We do need to replace the internal _target.
		 */
		DUK_DDD(DUK_DDDPRINT("no enumerate trap, enumerate proxy target instead"));
		DUK_DDD(DUK_DDDPRINT("h_proxy_target=%!O", (duk_heaphdr *) h_proxy_target));
		enum_target = h_proxy_target;

		duk_push_hobject(ctx, enum_target);  /* -> [ ... enum_target res handler undefined target ] */
		duk_put_prop_stridx(ctx, -4, DUK_STRIDX_INT_TARGET);

		duk_pop_2(ctx);  /* -> [ ... enum_target res ] */
		goto skip_proxy;
	}

	/* [ ... enum_target res handler trap ] */
	duk_insert(ctx, -2);
	duk_push_hobject(ctx, h_proxy_target);    /* -> [ ... enum_target res trap handler target ] */
	duk_call_method(ctx, 1 /*nargs*/);        /* -> [ ... enum_target res trap_result ] */
	h_trap_result = duk_require_hobject(ctx, -1);
	DUK_UNREF(h_trap_result);

	/* Copy trap result keys into the enumerator object. */
	len = (duk_uint_fast32_t) duk_get_length(ctx, -1);
	for (i = 0; i < len; i++) {
		/* XXX: not sure what the correct semantic details are here,
		 * e.g. handling of missing values (gaps), handling of non-array
		 * trap results, etc.
		 *
		 * For keys, we simply skip non-string keys which seems to be
		 * consistent with how e.g. Object.keys() will process proxy trap
		 * results (ES6 draft, Section 19.1.2.14).
		 */
		if (duk_get_prop_index(ctx, -1, i) && duk_is_string(ctx, -1)) {
			/* [ ... enum_target res trap_result val ] */
			duk_push_true(ctx);
			/* [ ... enum_target res trap_result val true ] */
			duk_put_prop(ctx, -4);
		} else {
			duk_pop(ctx);
		}
	}
	/* [ ... enum_target res trap_result ] */
	duk_pop(ctx);
	duk_remove(ctx, -2);

	/* [ ... res ] */

	/* The internal _target property is kept pointing to the original
	 * enumeration target (the proxy object), so that the enumerator
	 * 'next' operation can read property values if so requested.  The
	 * fact that the _target is a proxy disables key existence check
	 * during enumeration.
	 */
	DUK_DDD(DUK_DDDPRINT("proxy enumeration, final res: %!O", (duk_heaphdr *) res));
	goto compact_and_return;

 skip_proxy:
#endif  /* DUK_USE_ES6_PROXY */

	curr = enum_target;
	while (curr) {
		/*
		 *  Virtual properties.
		 *
		 *  String and buffer indices are virtual and always enumerable,
		 *  'length' is virtual and non-enumerable.  Array and arguments
		 *  object props have special behavior but are concrete.
		 */

		if (DUK_HOBJECT_HAS_EXOTIC_STRINGOBJ(curr) ||
		    DUK_HOBJECT_HAS_EXOTIC_BUFFEROBJ(curr)) {
			/* String and buffer enumeration behavior is identical now,
			 * so use shared handler.
			 */
			if (DUK_HOBJECT_HAS_EXOTIC_STRINGOBJ(curr)) {
				duk_hstring *h_val;
				h_val = duk_hobject_get_internal_value_string(thr->heap, curr);
				DUK_ASSERT(h_val != NULL);  /* string objects must not created without internal value */
				len = (duk_uint_fast32_t) DUK_HSTRING_GET_CHARLEN(h_val);
			} else {
				duk_hbuffer *h_val;
				DUK_ASSERT(DUK_HOBJECT_HAS_EXOTIC_BUFFEROBJ(curr));
				h_val = duk_hobject_get_internal_value_buffer(thr->heap, curr);
				DUK_ASSERT(h_val != NULL);  /* buffer objects must not created without internal value */
				len = (duk_uint_fast32_t) DUK_HBUFFER_GET_SIZE(h_val);
			}

			for (i = 0; i < len; i++) {
				duk_hstring *k;

				k = duk_heap_string_intern_u32_checked(thr, i);
				DUK_ASSERT(k);
				duk_push_hstring(ctx, k);
				duk_push_true(ctx);

				/* [enum_target res key true] */
				duk_put_prop(ctx, -3);

				/* [enum_target res] */
			}

			/* 'length' property is not enumerable, but is included if
			 * non-enumerable properties are requested.
			 */

			if (enum_flags & DUK_ENUM_INCLUDE_NONENUMERABLE) {
				duk_push_hstring_stridx(ctx, DUK_STRIDX_LENGTH);
				duk_push_true(ctx);
				duk_put_prop(ctx, -3);
			}
		} else if (DUK_HOBJECT_HAS_EXOTIC_DUKFUNC(curr)) {
			if (enum_flags & DUK_ENUM_INCLUDE_NONENUMERABLE) {
				duk_push_hstring_stridx(ctx, DUK_STRIDX_LENGTH);
				duk_push_true(ctx);
				duk_put_prop(ctx, -3);
			}
		}

		/*
		 *  Array part
		 *
		 *  Note: ordering between array and entry part must match 'abandon array'
		 *  behavior in duk_hobject_props.c: key order after an array is abandoned
		 *  must be the same.
		 */

		for (i = 0; i < (duk_uint_fast32_t) curr->a_size; i++) {
			duk_hstring *k;
			duk_tval *tv;

			tv = DUK_HOBJECT_A_GET_VALUE_PTR(curr, i);
			if (DUK_TVAL_IS_UNDEFINED_UNUSED(tv)) {
				continue;
			}
			k = duk_heap_string_intern_u32_checked(thr, i);
			DUK_ASSERT(k);

			duk_push_hstring(ctx, k);
			duk_push_true(ctx);

			/* [enum_target res key true] */
			duk_put_prop(ctx, -3);

			/* [enum_target res] */
		}

		/*
		 *  Entries part
		 */

		for (i = 0; i < (duk_uint_fast32_t) curr->e_next; i++) {
			duk_hstring *k;

			k = DUK_HOBJECT_E_GET_KEY(curr, i);
			if (!k) {
				continue;
			}
			if (!DUK_HOBJECT_E_SLOT_IS_ENUMERABLE(curr, i) &&
			    !(enum_flags & DUK_ENUM_INCLUDE_NONENUMERABLE)) {
				continue;
			}
			if (DUK_HSTRING_HAS_INTERNAL(k) &&
			    !(enum_flags & DUK_ENUM_INCLUDE_INTERNAL)) {
				continue;
			}
			if ((enum_flags & DUK_ENUM_ARRAY_INDICES_ONLY) &&
			    (DUK_HSTRING_GET_ARRIDX_SLOW(k) == DUK_HSTRING_NO_ARRAY_INDEX)) {
				continue;
			}

			DUK_ASSERT(DUK_HOBJECT_E_SLOT_IS_ACCESSOR(curr, i) ||
			           !DUK_TVAL_IS_UNDEFINED_UNUSED(&DUK_HOBJECT_E_GET_VALUE_PTR(curr, i)->v));

			duk_push_hstring(ctx, k);
			duk_push_true(ctx);

			/* [enum_target res key true] */
			duk_put_prop(ctx, -3);

			/* [enum_target res] */
		}

		if (enum_flags & DUK_ENUM_OWN_PROPERTIES_ONLY) {
			break;
		}

		curr = curr->prototype;
	}

	/* [enum_target res] */

	duk_remove(ctx, -2);

	/* [res] */

	if ((enum_flags & (DUK_ENUM_ARRAY_INDICES_ONLY | DUK_ENUM_SORT_ARRAY_INDICES)) ==
	                  (DUK_ENUM_ARRAY_INDICES_ONLY | DUK_ENUM_SORT_ARRAY_INDICES)) {
		/*
		 *  Some E5/E5.1 algorithms require that array indices are iterated
		 *  in a strictly ascending order.  This is the case for e.g.
		 *  Array.prototype.forEach() and JSON.stringify() PropertyList
		 *  handling.
		 *
		 *  To ensure this property for arrays with an array part (and
		 *  arbitrary objects too, since e.g. forEach() can be applied
		 *  to an array), the caller can request that we sort the keys
		 *  here.
		 */

		/* XXX: avoid this at least when enum_target is an Array, it has an
		 * array part, and no ancestor properties were included?  Not worth
		 * it for JSON, but maybe worth it for forEach().
		 */

		/* XXX: may need a 'length' filter for forEach()
		 */
		DUK_DDD(DUK_DDDPRINT("sort array indices by caller request"));
		duk__sort_array_indices(res);
	}

#if defined(DUK_USE_ES6_PROXY)
 compact_and_return:
#endif
	/* compact; no need to seal because object is internal */
	duk_hobject_compact_props(thr, res);

	DUK_DDD(DUK_DDDPRINT("created enumerator object: %!iT", (duk_tval *) duk_get_tval(ctx, -1)));
}
void duk_hobject_enumerator_create(duk_context *ctx, int enum_flags) {
	duk_hthread *thr = (duk_hthread *) ctx;
	duk_hobject *target;
	duk_hobject *curr;
	duk_hobject *res;

	DUK_ASSERT(ctx != NULL);

	DUK_DDDPRINT("create enumerator, stack top: %d", duk_get_top(ctx));

	target = duk_require_hobject(ctx, -1);
	DUK_ASSERT(target != NULL);

	duk_push_object_internal(ctx);

	DUK_DDDPRINT("created internal object");

	/* [target res] */

	duk_push_hstring_stridx(ctx, DUK_STRIDX_INT_TARGET);
	duk_push_hobject(ctx, target);
	duk_put_prop(ctx, -3);

	/* initialize index so that we skip internal control keys */
	duk_push_hstring_stridx(ctx, DUK_STRIDX_INT_NEXT);
	duk_push_int(ctx, ENUM_START_INDEX);
	duk_put_prop(ctx, -3);

	curr = target;
	while (curr) {
		duk_uint32_t i;

		/*
		 *  Virtual properties.
		 *
		 *  String indices are virtual and always enumerable.  String 'length'
		 *  is virtual and non-enumerable.  Array and arguments object props
		 *  have special behavior but are concrete.
		 */

		if (DUK_HOBJECT_HAS_SPECIAL_STRINGOBJ(curr)) {
			duk_hstring *h_val;

			h_val = duk_hobject_get_internal_value_string(thr->heap, curr);
			DUK_ASSERT(h_val != NULL);  /* string objects must not created without internal value */

			/* FIXME: type for 'i' to match string max len (duk_uint32_t) */
			for (i = 0; i < DUK_HSTRING_GET_CHARLEN(h_val); i++) {
				duk_hstring *k;

				k = duk_heap_string_intern_u32_checked(thr, i);
				DUK_ASSERT(k);
				duk_push_hstring(ctx, k);
				duk_push_true(ctx);

				/* [target res key true] */
				duk_put_prop(ctx, -3);

				/* [target res] */	
			}

			/* 'length' property is not enumerable, but is included if
			 * non-enumerable properties are requested.
			 */

			if (enum_flags & DUK_ENUM_INCLUDE_NONENUMERABLE) {
				duk_push_hstring_stridx(ctx, DUK_STRIDX_LENGTH);
				duk_push_true(ctx);
				duk_put_prop(ctx, -3);
			}
		}

		/*
		 *  Array part
		 *
		 *  Note: ordering between array and entry part must match 'abandon array'
		 *  behavior in duk_hobject_props.c: key order after an array is abandoned
		 *  must be the same.
		 */

		for (i = 0; i < curr->a_size; i++) {
			duk_hstring *k;
			duk_tval *tv;

			tv = DUK_HOBJECT_A_GET_VALUE_PTR(curr, i);
			if (DUK_TVAL_IS_UNDEFINED_UNUSED(tv)) {
				continue;
			}
			k = duk_heap_string_intern_u32_checked(thr, i);
			DUK_ASSERT(k);

			duk_push_hstring(ctx, k);
			duk_push_true(ctx);

			/* [target res key true] */
			duk_put_prop(ctx, -3);

			/* [target res] */
		}

		/*
		 *  Entries part
		 */

		for (i = 0; i < curr->e_used; i++) {
			duk_hstring *k;

			k = DUK_HOBJECT_E_GET_KEY(curr, i);
			if (!k) {
				continue;
			}
			if (!DUK_HOBJECT_E_SLOT_IS_ENUMERABLE(curr, i) &&
			    !(enum_flags & DUK_ENUM_INCLUDE_NONENUMERABLE)) {
				continue;
			}
			if (DUK_HSTRING_HAS_INTERNAL(k) &&
			    !(enum_flags & DUK_ENUM_INCLUDE_INTERNAL)) {
				continue;
			}
			if ((enum_flags & DUK_ENUM_ARRAY_INDICES_ONLY) &&
			    (DUK_HSTRING_GET_ARRIDX_SLOW(k) == DUK_HSTRING_NO_ARRAY_INDEX)) {
				continue;
			}

			DUK_ASSERT(DUK_HOBJECT_E_SLOT_IS_ACCESSOR(curr, i) ||
			           !DUK_TVAL_IS_UNDEFINED_UNUSED(&DUK_HOBJECT_E_GET_VALUE_PTR(curr, i)->v));

			duk_push_hstring(ctx, k);
			duk_push_true(ctx);

			/* [target res key true] */
			duk_put_prop(ctx, -3);

			/* [target res] */
		}

		if (enum_flags & DUK_ENUM_OWN_PROPERTIES_ONLY) {
			break;
		}

		curr = curr->prototype;
	}

	/* [target res] */

	duk_remove(ctx, -2);
	res = duk_require_hobject(ctx, -1);

	/* [res] */

	if ((enum_flags & (DUK_ENUM_ARRAY_INDICES_ONLY | DUK_ENUM_SORT_ARRAY_INDICES)) ==
	                  (DUK_ENUM_ARRAY_INDICES_ONLY | DUK_ENUM_SORT_ARRAY_INDICES)) {
		/*
		 *  Some E5/E5.1 algorithms require that array indices are iterated
		 *  in a strictly ascending order.  This is the case for e.g.
		 *  Array.prototype.forEach() and JSON.stringify() PropertyList
		 *  handling.
		 *
		 *  To ensure this property for arrays with an array part (and
		 *  arbitrary objects too, since e.g. forEach() can be applied
		 *  to an array), the caller can request that we sort the keys
		 *  here.
		 */

		/* FIXME: avoid this at least when target is an Array, it has an
		 * array part, and no ancestor properties were included?  Not worth
		 * it for JSON, but maybe worth it for forEach().
		 */

		/* FIXME: may need a 'length' filter for forEach()
		 */
		DUK_DDDPRINT("sort array indices by caller request");
		sort_array_indices(res);
	}

	/* compact; no need to seal because object is internal */
	duk_hobject_compact_props(thr, res);

	DUK_DDDPRINT("created enumerator object: %!iT", duk_get_tval(ctx, -1));
}