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lib/JavaScript/Embedded/C/lib/duktape.c  view on Meta::CPAN

				                     (duk_tval *) duk_require_tval(thr, idx_value)));

				/* strict flag for putvar comes from our caller (currently: fixed) */
				duk_js_putvar_envrec(thr, varenv, varname, duk_require_tval(thr, idx_value), 1 /*throw_flag*/);
			}
			if (has_writable && !is_writable) {
				DUK_DDD(DUK_DDDPRINT("defineProperty successful, key mapped to arguments 'map', "
				                     "changed to non-writable, delete arguments binding"));

				(void) duk_hobject_delprop_raw(thr, map, key, 0); /* ignore result */
			}
		}

		/* 'varname' is in stack in this else branch, leaving an unbalanced stack below,
		 * but this doesn't matter now.
		 */
	}

success_no_exotics:
	/* Some code paths use NORZ macros for simplicity, ensure refzero
	 * handling is completed.
	 */
	DUK_REFZERO_CHECK_SLOW(thr);
	return 1;

fail_not_extensible:
	if (throw_flag) {
		DUK_ERROR_TYPE(thr, DUK_STR_NOT_EXTENSIBLE);
		DUK_WO_NORETURN(return 0;);
	}
	return 0;

fail_virtual: /* just use the same "not configurable" error message" */
fail_not_configurable:
	if (throw_flag) {
		DUK_ERROR_TYPE(thr, DUK_STR_NOT_CONFIGURABLE);
		DUK_WO_NORETURN(return 0;);
	}
	return 0;
}

/*
 *  Object.prototype.hasOwnProperty() and Object.prototype.propertyIsEnumerable().
 */

DUK_INTERNAL duk_bool_t duk_hobject_object_ownprop_helper(duk_hthread *thr, duk_small_uint_t required_desc_flags) {
	duk_hstring *h_v;
	duk_hobject *h_obj;
	duk_propdesc desc;
	duk_bool_t ret;

	/* coercion order matters */
	h_v = duk_to_hstring_acceptsymbol(thr, 0);
	DUK_ASSERT(h_v != NULL);

	h_obj = duk_push_this_coercible_to_object(thr);
	DUK_ASSERT(h_obj != NULL);

	ret = duk_hobject_get_own_propdesc(thr, h_obj, h_v, &desc, 0 /*flags*/); /* don't push value */

	duk_push_boolean(thr, ret && ((desc.flags & required_desc_flags) == required_desc_flags));
	return 1;
}

/*
 *  Object.seal() and Object.freeze()  (E5 Sections 15.2.3.8 and 15.2.3.9)
 *
 *  Since the algorithms are similar, a helper provides both functions.
 *  Freezing is essentially sealing + making plain properties non-writable.
 *
 *  Note: virtual (non-concrete) properties which are non-configurable but
 *  writable would pose some problems, but such properties do not currently
 *  exist (all virtual properties are non-configurable and non-writable).
 *  If they did exist, the non-configurability does NOT prevent them from
 *  becoming non-writable.  However, this change should be recorded somehow
 *  so that it would turn up (e.g. when getting the property descriptor),
 *  requiring some additional flags in the object.
 */

DUK_INTERNAL void duk_hobject_object_seal_freeze_helper(duk_hthread *thr, duk_hobject *obj, duk_bool_t is_freeze) {
	duk_uint_fast32_t i;

	DUK_ASSERT(thr != NULL);
	DUK_ASSERT(thr->heap != NULL);
	DUK_ASSERT(obj != NULL);

	DUK_ASSERT_VALSTACK_SPACE(thr, DUK__VALSTACK_SPACE);

#if defined(DUK_USE_ROM_OBJECTS)
	if (DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj)) {
		DUK_DD(DUK_DDPRINT("attempt to seal/freeze a readonly object, reject"));
		DUK_ERROR_TYPE(thr, DUK_STR_NOT_CONFIGURABLE);
		DUK_WO_NORETURN(return;);
	}
#endif

	/*
	 *  Abandon array part because all properties must become non-configurable.
	 *  Note that this is now done regardless of whether this is always the case
	 *  (skips check, but performance problem if caller would do this many times
	 *  for the same object; not likely).
	 */

	duk__abandon_array_part(thr, obj);
	DUK_ASSERT(DUK_HOBJECT_GET_ASIZE(obj) == 0);

	for (i = 0; i < DUK_HOBJECT_GET_ENEXT(obj); i++) {
		duk_uint8_t *fp;

		/* since duk__abandon_array_part() causes a resize, there should be no gaps in keys */
		DUK_ASSERT(DUK_HOBJECT_E_GET_KEY(thr->heap, obj, i) != NULL);

		/* avoid multiple computations of flags address; bypasses macros */
		fp = DUK_HOBJECT_E_GET_FLAGS_PTR(thr->heap, obj, i);
		if (is_freeze && !((*fp) & DUK_PROPDESC_FLAG_ACCESSOR)) {
			*fp &= ~(DUK_PROPDESC_FLAG_WRITABLE | DUK_PROPDESC_FLAG_CONFIGURABLE);
		} else {
			*fp &= ~DUK_PROPDESC_FLAG_CONFIGURABLE;
		}
	}