path: root/js/src/builtin/Utilities.js

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "SelfHostingDefines.h"

// Assertions and debug printing, defined here instead of in the header above
// to make `assert` invisible to C++.
#ifdef DEBUG
#define assert(b, info) \
    do { \
        if (!(b)) \
            AssertionFailed(__FILE__ + ":" + __LINE__ + ": " + info) \
    } while (false)
#define dbg(msg) \
    do { \
        DumpMessage(callFunction(std_Array_pop, \
                                 StringSplitString(__FILE__, '/')) + \
                    '#' + __LINE__ + ': ' + msg) \
    } while (false)
#else
#define assert(b, info) ; // Elided assertion.
#define dbg(msg) ; // Elided debugging output.
#endif

// All C++-implemented standard builtins library functions used in self-hosted
// code are installed via the std_functions JSFunctionSpec[] in
// SelfHosting.cpp.
//
// Do not create an alias to a self-hosted builtin, otherwise it will be cloned
// twice.
//
// Symbol is a bare constructor without properties or methods.
var std_Symbol = Symbol;


/********** List specification type **********/

/* Spec: ECMAScript Language Specification, 5.1 edition, 8.8 */
function List() {
    this.length = 0;
}
MakeConstructible(List, {__proto__: null});


/********** Record specification type **********/


/* Spec: ECMAScript Internationalization API Specification, draft, 5 */
function Record() {
    return std_Object_create(null);
}
MakeConstructible(Record, {});


/********** Abstract operations defined in ECMAScript Language Specification **********/


/* Spec: ECMAScript Language Specification, 5.1 edition, 9.2 and 11.4.9 */
function ToBoolean(v) {
    return !!v;
}


/* Spec: ECMAScript Language Specification, 5.1 edition, 9.3 and 11.4.6 */
function ToNumber(v) {
    return +v;
}

// ES2017 draft rev aebf014403a3e641fb1622aec47c40f051943527
// 7.2.10 SameValueZero ( x, y )
function SameValueZero(x, y) {
    return x === y || (x !== x && y !== y);
}

// ES 2017 draft (April 6, 2016) 7.3.9
function GetMethod(V, P) {
    // Step 1.
    assert(IsPropertyKey(P), "Invalid property key");

    // Step 2.
    var func = V[P];

    // Step 3.
    if (func === undefined || func === null)
        return undefined;

    // Step 4.
    if (!IsCallable(func))
        ThrowTypeError(JSMSG_NOT_FUNCTION, typeof func);

    // Step 5.
    return func;
}

/* Spec: ECMAScript Draft, 6th edition Dec 24, 2014, 7.2.7 */
function IsPropertyKey(argument) {
    var type = typeof argument;
    return type === "string" || type === "symbol";
}

#define TO_PROPERTY_KEY(name) \
(typeof name !== "string" && typeof name !== "number" && typeof name !== "symbol" ? ToPropertyKey(name) : name)

// ES 2016 draft Mar 25, 2016 7.3.20.
function SpeciesConstructor(obj, defaultConstructor) {
    // Step 1.
    assert(IsObject(obj), "not passed an object");

    // Step 2.
    var ctor = obj.constructor;

    // Step 3.
    if (ctor === undefined)
        return defaultConstructor;

    // Step 4.
    if (!IsObject(ctor))
        ThrowTypeError(JSMSG_OBJECT_REQUIRED, "object's 'constructor' property");

    // Steps 5.
    var s = ctor[std_species];

    // Step 6.
    if (s === undefined || s === null)
        return defaultConstructor;

    // Step 7.
    if (IsConstructor(s))
        return s;

    // Step 8.
    ThrowTypeError(JSMSG_NOT_CONSTRUCTOR, "@@species property of object's constructor");
}

function GetTypeError(msg) {
    try {
        FUN_APPLY(ThrowTypeError, undefined, arguments);
    } catch (e) {
        return e;
    }
    assert(false, "the catch block should've returned from this function.");
}

function GetAggregateError(msg) {
    try {
        FUN_APPLY(ThrowAggregateError, undefined, arguments);
    } catch (e) {
        return e;
    }
    assert(false, "the catch block should've returned from this function.");
}

function GetInternalError(msg) {
    try {
        FUN_APPLY(ThrowInternalError, undefined, arguments);
    } catch (e) {
        return e;
    }
    assert(false, "the catch block should've returned from this function.");
}

// To be used when a function is required but calling it shouldn't do anything.
function NullFunction() {}

// ES2019 draft rev 4c2df13f4194057f09b920ee88712e5a70b1a556
// 7.3.23 CopyDataProperties (target, source, excludedItems)
function CopyDataProperties(target, source, excludedItems) {
    // Step 1.
    assert(IsObject(target), "target is an object");

    // Step 2.
    assert(IsObject(excludedItems), "excludedItems is an object");

    // Steps 3 and 7.
    if (source === undefined || source === null)
        return;

    // Step 4.
    var from = ToObject(source);

    // Step 5.
    var keys = CopyDataPropertiesOrGetOwnKeys(target, from, excludedItems);

    // Return if we copied all properties in native code.
    if (keys === null)
        return;

    // Step 6.
    for (var index = 0; index < keys.length; index++) {
        var key = keys[index];

        // We abbreviate this by calling propertyIsEnumerable which is faster
        // and returns false for not defined properties.
        if (!hasOwn(key, excludedItems) &&
            callFunction(std_Object_propertyIsEnumerable, from, key))
        {
            _DefineDataProperty(target, key, from[key]);
        }
    }

    // Step 7 (Return).
}

// ES2019 draft rev 4c2df13f4194057f09b920ee88712e5a70b1a556
// 7.3.23 CopyDataProperties (target, source, excludedItems)
function CopyDataPropertiesUnfiltered(target, source) {
    // Step 1.
    assert(IsObject(target), "target is an object");

    // Step 2 (Not applicable).

    // Steps 3 and 7.
    if (source === undefined || source === null)
        return;

    // Step 4.
    var from = ToObject(source);

    // Step 5.
    var keys = CopyDataPropertiesOrGetOwnKeys(target, from, null);

    // Return if we copied all properties in native code.
    if (keys === null)
        return;

    // Step 6.
    for (var index = 0; index < keys.length; index++) {
        var key = keys[index];

        // We abbreviate this by calling propertyIsEnumerable which is faster
        // and returns false for not defined properties.
        if (callFunction(std_Object_propertyIsEnumerable, from, key))
            _DefineDataProperty(target, key, from[key]);
    }

    // Step 7 (Return).
}

/*************************************** Testing functions ***************************************/
function outer() {
    return function inner() {
        return "foo";
    };
}