DUK_INTERNAL duk_ret_t duk_bi_string_prototype_to_string(duk_context *ctx) {
duk_tval *tv;
duk_push_this(ctx);
tv = duk_require_tval(ctx, -1);
DUK_ASSERT(tv != NULL);
if (DUK_TVAL_IS_STRING(tv)) {
/* return as is */
return 1;
} else if (DUK_TVAL_IS_OBJECT(tv)) {
duk_hobject *h = DUK_TVAL_GET_OBJECT(tv);
DUK_ASSERT(h != NULL);
/* Must be a "string object", i.e. class "String" */
if (DUK_HOBJECT_GET_CLASS_NUMBER(h) != DUK_HOBJECT_CLASS_STRING) {
goto type_error;
}
duk_get_prop_stridx(ctx, -1, DUK_STRIDX_INT_VALUE);
DUK_ASSERT(duk_is_string(ctx, -1));
return 1;
} else {
goto type_error;
}
/* never here, but fall through */
type_error:
DUK_DCERROR_TYPE_INVALID_ARGS((duk_hthread *) ctx);
}
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 */
}
/* Shared helper to implement Object.getPrototypeOf,
* Object.prototype.__proto__ getter, and Reflect.getPrototypeOf.
*
* http://www.ecma-international.org/ecma-262/6.0/index.html#sec-get-object.prototype.__proto__
*/
DUK_INTERNAL duk_ret_t duk_bi_object_getprototype_shared(duk_context *ctx) {
/*
* magic = 0: __proto__ getter
* magic = 1: Object.getPrototypeOf()
* magic = 2: Reflect.getPrototypeOf()
*/
duk_hthread *thr = (duk_hthread *) ctx;
duk_hobject *h;
duk_hobject *proto;
duk_tval *tv;
duk_int_t magic;
magic = duk_get_current_magic(ctx);
if (magic == 0) {
DUK_ASSERT_TOP(ctx, 0);
duk_push_this_coercible_to_object(ctx);
}
DUK_ASSERT(duk_get_top(ctx) >= 1);
if (magic < 2) {
/* ES2015 Section 19.1.2.9, step 1 */
duk_to_object(ctx, 0);
}
tv = DUK_GET_TVAL_POSIDX(ctx, 0);
switch (DUK_TVAL_GET_TAG(tv)) {
case DUK_TAG_BUFFER:
proto = thr->builtins[DUK_BIDX_UINT8ARRAY_PROTOTYPE];
break;
case DUK_TAG_LIGHTFUNC:
proto = thr->builtins[DUK_BIDX_FUNCTION_PROTOTYPE];
break;
case DUK_TAG_OBJECT:
h = DUK_TVAL_GET_OBJECT(tv);
proto = DUK_HOBJECT_GET_PROTOTYPE(thr->heap, h);
break;
default:
/* This implicitly handles CheckObjectCoercible() caused
* TypeError.
*/
DUK_DCERROR_TYPE_INVALID_ARGS(thr);
}
if (proto != NULL) {
duk_push_hobject(ctx, proto);
} else {
duk_push_null(ctx);
}
return 1;
}
/* Shared helper for providing .source, .global, .multiline, etc getters. */
DUK_INTERNAL duk_ret_t duk_bi_regexp_prototype_shared_getter(duk_hthread *thr) {
duk_hstring *h_bc;
duk_small_uint_t re_flags;
duk_hobject *h;
duk_int_t magic;
DUK_ASSERT_TOP(thr, 0);
duk_push_this(thr);
h = duk_require_hobject(thr, -1);
magic = duk_get_current_magic(thr);
if (DUK_HOBJECT_GET_CLASS_NUMBER(h) == DUK_HOBJECT_CLASS_REGEXP) {
duk_get_prop_stridx_short(thr, 0, DUK_STRIDX_INT_SOURCE);
duk_get_prop_stridx_short(thr, 0, DUK_STRIDX_INT_BYTECODE);
h_bc = duk_require_hstring(thr, -1);
re_flags = (duk_small_uint_t) DUK_HSTRING_GET_DATA(h_bc)[0]; /* Safe even if h_bc length is 0 (= NUL) */
duk_pop(thr);
} else if (h == thr->builtins[DUK_BIDX_REGEXP_PROTOTYPE]) {
/* In ES2015 and ES2016 a TypeError would be thrown here.
* However, this had real world issues so ES2017 draft
* allows RegExp.prototype specifically, returning '(?:)'
* for .source and undefined for all flags.
*/
if (magic != 16 /* .source */) {
return 0;
}
duk_push_literal(thr, "(?:)"); /* .source handled by switch-case */
re_flags = 0;
} else {
DUK_DCERROR_TYPE_INVALID_ARGS(thr);
}
/* [ regexp source ] */
switch (magic) {
case 0: { /* global */
duk_push_boolean(thr, (re_flags & DUK_RE_FLAG_GLOBAL));
break;
}
case 1: { /* ignoreCase */
duk_push_boolean(thr, (re_flags & DUK_RE_FLAG_IGNORE_CASE));
break;
}
case 2: { /* multiline */
duk_push_boolean(thr, (re_flags & DUK_RE_FLAG_MULTILINE));
break;
}
#if 0
/* Don't provide until implemented to avoid interfering with feature
* detection in user code.
*/
case 3: /* sticky */
case 4: { /* unicode */
duk_push_false(thr);
break;
}
#endif
default: { /* source */
/* leave 'source' on top */
break;
}
}
return 1;
}
/* Shared helper to implement ES2015 Object.setPrototypeOf,
* Object.prototype.__proto__ setter, and Reflect.setPrototypeOf.
*
* http://www.ecma-international.org/ecma-262/6.0/index.html#sec-get-object.prototype.__proto__
* http://www.ecma-international.org/ecma-262/6.0/index.html#sec-object.setprototypeof
*/
DUK_INTERNAL duk_ret_t duk_bi_object_setprototype_shared(duk_hthread *thr) {
/*
* magic = 0: __proto__ setter
* magic = 1: Object.setPrototypeOf()
* magic = 2: Reflect.setPrototypeOf()
*/
duk_hobject *h_obj;
duk_hobject *h_new_proto;
duk_hobject *h_curr;
duk_ret_t ret_success = 1; /* retval for success path */
duk_uint_t mask;
duk_int_t magic;
/* Preliminaries for __proto__ and setPrototypeOf (E6 19.1.2.18 steps 1-4). */
magic = duk_get_current_magic(thr);
if (magic == 0) {
duk_push_this_check_object_coercible(thr);
duk_insert(thr, 0);
if (!duk_check_type_mask(thr, 1, DUK_TYPE_MASK_NULL | DUK_TYPE_MASK_OBJECT)) {
return 0;
}
/* __proto__ setter returns 'undefined' on success unlike the
* setPrototypeOf() call which returns the target object.
*/
ret_success = 0;
} else {
if (magic == 1) {
duk_require_object_coercible(thr, 0);
} else {
duk_require_hobject_accept_mask(thr, 0,
DUK_TYPE_MASK_LIGHTFUNC |
DUK_TYPE_MASK_BUFFER);
}
duk_require_type_mask(thr, 1, DUK_TYPE_MASK_NULL | DUK_TYPE_MASK_OBJECT);
}
h_new_proto = duk_get_hobject(thr, 1);
/* h_new_proto may be NULL */
mask = duk_get_type_mask(thr, 0);
if (mask & (DUK_TYPE_MASK_LIGHTFUNC | DUK_TYPE_MASK_BUFFER)) {
duk_hobject *curr_proto;
curr_proto = thr->builtins[(mask & DUK_TYPE_MASK_LIGHTFUNC) ?
DUK_BIDX_FUNCTION_PROTOTYPE :
DUK_BIDX_UINT8ARRAY_PROTOTYPE];
if (h_new_proto == curr_proto) {
goto skip;
}
goto fail_nonextensible;
}
h_obj = duk_get_hobject(thr, 0);
if (h_obj == NULL) {
goto skip;
}
DUK_ASSERT(h_obj != NULL);
/* [[SetPrototypeOf]] standard behavior, E6 9.1.2. */
/* TODO: implement Proxy object support here */
if (h_new_proto == DUK_HOBJECT_GET_PROTOTYPE(thr->heap, h_obj)) {
goto skip;
}
if (!DUK_HOBJECT_HAS_EXTENSIBLE(h_obj)) {
goto fail_nonextensible;
}
for (h_curr = h_new_proto; h_curr != NULL; h_curr = DUK_HOBJECT_GET_PROTOTYPE(thr->heap, h_curr)) {
/* Loop prevention. */
if (h_curr == h_obj) {
goto fail_loop;
}
}
DUK_HOBJECT_SET_PROTOTYPE_UPDREF(thr, h_obj, h_new_proto);
/* fall thru */
skip:
duk_set_top(thr, 1);
if (magic == 2) {
duk_push_true(thr);
}
return ret_success;
fail_nonextensible:
fail_loop:
if (magic != 2) {
DUK_DCERROR_TYPE_INVALID_ARGS(thr);
} else {
duk_push_false(thr);
return 1;
}
}
