tor-browser

Utilities.js (5377B)

---

/* 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.

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

// 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 (IsNullOrUndefined(func)) {
   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[GetBuiltinSymbol("species")];

 // Step 6.
 if (IsNullOrUndefined(s)) {
   return defaultConstructor;
 }

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

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

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

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

function GetInternalError(...args) {
 try {
   FUN_APPLY(ThrowInternalError, undefined, args);
 } 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 (IsNullOrUndefined(source)) {
   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 (IsNullOrUndefined(source)) {
   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";
 };
}