Source/JavaScriptCore/builtins/PromiseOperations.js - external/github.com/WebKit/webkit - Git at Google

 /*
  * Copyright (C) 2015 Yusuke Suzuki <utatane.tea@gmail.com>.
  * Copyright (C) 2016-2019 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 // @internal

 @linkTimeConstant
 function pushNewPromiseReaction(thenable, existingReactions, promiseOrCapability, onFulfilled, onRejected, context)
 {
     "use strict";

     if (!existingReactions) {
         existingReactions = {
             @promiseOrCapability: promiseOrCapability,
             @onFulfilled: onFulfilled,
             @onRejected: onRejected,
             @context: context,
             // This is 4x the number of out of line reactions (promise, fulfill callback, reject callback, context).
             @outOfLineReactionCounts: 0,
         };
         @putPromiseInternalField(thenable, @promiseFieldReactionsOrResult, existingReactions);
     } else {
         var outOfLineReactionCounts = existingReactions.@outOfLineReactionCounts;
         @putByValDirect(existingReactions, outOfLineReactionCounts++, promiseOrCapability);
         @putByValDirect(existingReactions, outOfLineReactionCounts++, onFulfilled);
         @putByValDirect(existingReactions, outOfLineReactionCounts++, onRejected);
         @putByValDirect(existingReactions, outOfLineReactionCounts++, context);
         existingReactions.@outOfLineReactionCounts = outOfLineReactionCounts;
     }
 }

 @linkTimeConstant
 function newPromiseCapabilitySlow(constructor)
 {
     "use strict";

     var promiseCapability = {
         resolve: @undefined,
         reject: @undefined,
         promise: @undefined,
     };

     var promise = new constructor((resolve, reject) => {
         if (promiseCapability.resolve !== @undefined)
             @throwTypeError("resolve function is already set");
         if (promiseCapability.reject !== @undefined)
             @throwTypeError("reject function is already set");

         promiseCapability.resolve = resolve;
         promiseCapability.reject = reject;
     });

     if (!@isCallable(promiseCapability.resolve))
         @throwTypeError("executor did not take a resolve function");

     if (!@isCallable(promiseCapability.reject))
         @throwTypeError("executor did not take a reject function");

     promiseCapability.promise = promise;

     return promiseCapability;
 }

 @linkTimeConstant
 function newPromiseCapability(constructor)
 {
     "use strict";

     if (constructor === @Promise) {
         var promise = @newPromise();
         var capturedPromise = promise;
         function @resolve(resolution) {
             return @resolvePromiseWithFirstResolvingFunctionCallCheck(capturedPromise, resolution);
         }
         function @reject(reason) {
             return @rejectPromiseWithFirstResolvingFunctionCallCheck(capturedPromise, reason);
         }
         return { resolve: @resolve, reject: @reject, promise };
     }

     return @newPromiseCapabilitySlow(constructor);
 }

 @linkTimeConstant
 function promiseResolve(constructor, value)
 {
     "use strict";

     if (@isPromise(value) && value.constructor === constructor)
         return value;

     if (constructor === @Promise) {
         var promise = @newPromise();
         @resolvePromiseWithFirstResolvingFunctionCallCheck(promise, value);
         return promise;
     }

     return @promiseResolveSlow(constructor, value);
 }

 @linkTimeConstant
 function promiseResolveSlow(constructor, value)
 {
     "use strict";

     @assert(constructor !== @Promise);
     var promiseCapability = @newPromiseCapabilitySlow(constructor);
     promiseCapability.resolve.@call(@undefined, value);
     return promiseCapability.promise;
 }

 @linkTimeConstant
 function promiseRejectSlow(constructor, reason)
 {
     "use strict";

     @assert(constructor !== @Promise);
     var promiseCapability = @newPromiseCapabilitySlow(constructor);
     promiseCapability.reject.@call(@undefined, reason);
     return promiseCapability.promise;
 }

 @linkTimeConstant
 function newHandledRejectedPromise(error)
 {
     "use strict";
     var promise = @newPromise();
     @rejectPromiseWithFirstResolvingFunctionCallCheck(promise, error);
     @putPromiseInternalField(promise, @promiseFieldFlags, @getPromiseInternalField(promise, @promiseFieldFlags) | @promiseFlagsIsHandled);
     return promise;
 }

 @linkTimeConstant
 function triggerPromiseReactions(state, reactions, argument)
 {
     "use strict";

     if (!reactions)
         return;

     var isResolved = state === @promiseStateFulfilled;
     var handler = isResolved ? reactions.@onFulfilled : reactions.@onRejected;

     @enqueueJob(@promiseReactionJob, reactions.@promiseOrCapability, handler, argument, handler ? reactions.@context : state);

     for (var i = 0, count = reactions.@outOfLineReactionCounts; i < count; i += 4) {
         var promise = reactions[i];
         var handler = isResolved ? reactions[i + 1] : reactions[i + 2];
         var context = reactions[i + 3];
         @enqueueJob(@promiseReactionJob, promise, handler, argument, handler ? context : state);
     }
     @assert(i === count);
 }

 @linkTimeConstant
 function resolvePromise(promise, resolution)
 {
     "use strict";

     @assert(@isPromise(promise));

     if (resolution === promise)
         return @rejectPromise(promise, @makeTypeError("Cannot resolve a promise with itself"));

     if (!@isObject(resolution))
         return @fulfillPromise(promise, resolution);

     var then;
     try {
         then = resolution.then;
     } catch (error) {
         return @rejectPromise(promise, error);
     }

     if (@isPromise(resolution) && then === @defaultPromiseThen) {
         @enqueueJob(@promiseResolveThenableJobFast, resolution, promise);
         return;
     }

     if (!@isCallable(then))
         return @fulfillPromise(promise, resolution);

     @enqueueJob(@promiseResolveThenableJob, resolution, then, @createResolvingFunctions(promise));
 }

 // Keep in sync with JSPromise::rejectedPromise.
 @linkTimeConstant
 function rejectPromise(promise, reason)
 {
     "use strict";

     @assert(@isPromise(promise));
     @assert((@getPromiseInternalField(promise, @promiseFieldFlags) & @promiseStateMask) == @promiseStatePending);

     var flags = @getPromiseInternalField(promise, @promiseFieldFlags);
     var reactions = @getPromiseInternalField(promise, @promiseFieldReactionsOrResult);
     @putPromiseInternalField(promise, @promiseFieldReactionsOrResult, reason);
     @putPromiseInternalField(promise, @promiseFieldFlags, flags | @promiseStateRejected);

     if (!(flags & @promiseFlagsIsHandled))
         @hostPromiseRejectionTracker(promise, @promiseRejectionReject);

     @triggerPromiseReactions(@promiseStateRejected, reactions, reason);
 }

 @linkTimeConstant
 function fulfillPromise(promise, value)
 {
     "use strict";

     @assert(@isPromise(promise));
     @assert((@getPromiseInternalField(promise, @promiseFieldFlags) & @promiseStateMask) == @promiseStatePending);

     var flags = @getPromiseInternalField(promise, @promiseFieldFlags);
     var reactions = @getPromiseInternalField(promise, @promiseFieldReactionsOrResult);
     @putPromiseInternalField(promise, @promiseFieldReactionsOrResult, value);
     @putPromiseInternalField(promise, @promiseFieldFlags, flags | @promiseStateFulfilled);

     @triggerPromiseReactions(@promiseStateFulfilled, reactions, value);
 }

 @linkTimeConstant
 function resolvePromiseWithFirstResolvingFunctionCallCheck(promise, value)
 {
     "use strict";

     @assert(@isPromise(promise));
     var flags = @getPromiseInternalField(promise, @promiseFieldFlags);
     if (flags & @promiseFlagsIsFirstResolvingFunctionCalled)
         return;
     @putPromiseInternalField(promise, @promiseFieldFlags, flags | @promiseFlagsIsFirstResolvingFunctionCalled);
     return @resolvePromise(promise, value);
 }

 @linkTimeConstant
 function fulfillPromiseWithFirstResolvingFunctionCallCheck(promise, value)
 {
     "use strict";

     @assert(@isPromise(promise));
     var flags = @getPromiseInternalField(promise, @promiseFieldFlags);
     if (flags & @promiseFlagsIsFirstResolvingFunctionCalled)
         return;
     @putPromiseInternalField(promise, @promiseFieldFlags, flags | @promiseFlagsIsFirstResolvingFunctionCalled);
     return @fulfillPromise(promise, value);
 }

 @linkTimeConstant
 function rejectPromiseWithFirstResolvingFunctionCallCheck(promise, reason)
 {
     "use strict";

     @assert(@isPromise(promise));
     var flags = @getPromiseInternalField(promise, @promiseFieldFlags);
     if (flags & @promiseFlagsIsFirstResolvingFunctionCalled)
         return;
     @putPromiseInternalField(promise, @promiseFieldFlags, flags | @promiseFlagsIsFirstResolvingFunctionCalled);
     return @rejectPromise(promise, reason);
 }

 @linkTimeConstant
 function createResolvingFunctions(promise)
 {
     "use strict";
     @assert(@isPromise(promise));

     var alreadyResolved = false;

     var resolve = (0, /* prevent function name inference */ (resolution) => {
         if (alreadyResolved)
             return @undefined;
         alreadyResolved = true;

         return @resolvePromise(promise, resolution);
     });

     var reject = (0, /* prevent function name inference */ (reason) => {
         if (alreadyResolved)
             return @undefined;
         alreadyResolved = true;

         return @rejectPromise(promise, reason);
     });

     return { resolve, reject };
 }

 @linkTimeConstant
 function promiseReactionJobWithoutPromise(handler, argument, context)
 {
     "use strict";

     try {
         if (context)
             handler(argument, context);
         else
             handler(argument);
     } catch {
         // This is user-uncatchable promise. We just ignore the error here.
     }
 }

 // This function has strong guarantee that each handler function (onFulfilled and onRejected) will be called at most once.
 @linkTimeConstant
 function resolveWithoutPromise(resolution, onFulfilled, onRejected, context)
 {
     "use strict";

     if (!@isObject(resolution)) {
         @fulfillWithoutPromise(resolution, onFulfilled, onRejected, context);
         return;
     }

     var then;
     try {
         then = resolution.then;
     } catch (error) {
         @rejectWithoutPromise(error, onFulfilled, onRejected, context);
         return;
     }

     if (@isPromise(resolution) && then === @defaultPromiseThen) {
         @enqueueJob(@promiseResolveThenableJobWithoutPromiseFast, resolution, onFulfilled, onRejected, context);
         return;
     }

     if (!@isCallable(then)) {
         @fulfillWithoutPromise(resolution, onFulfilled, onRejected, context);
         return;
     }

     // Wrap onFulfilled and onRejected with @createResolvingFunctionsWithoutPromise to ensure that each function will be called at most once.
     @enqueueJob(@promiseResolveThenableJob, resolution, then, @createResolvingFunctionsWithoutPromise(onFulfilled, onRejected, context));
 }

 // This function has strong guarantee that each handler function (onFulfilled and onRejected) will be called at most once.
 @linkTimeConstant
 function rejectWithoutPromise(reason, onFulfilled, onRejected, context)
 {
     "use strict";

     @enqueueJob(@promiseReactionJobWithoutPromise, onRejected, reason, context);
 }

 // This function has strong guarantee that each handler function (onFulfilled and onRejected) will be called at most once.
 @linkTimeConstant
 function fulfillWithoutPromise(value, onFulfilled, onRejected, context)
 {
     "use strict";

     @enqueueJob(@promiseReactionJobWithoutPromise, onFulfilled, value, context);
 }

 // This function has strong guarantee that each handler function (onFulfilled and onRejected) will be called at most once.
 // This is special version of resolveWithoutPromise which skips resolution's then handling.
 // https://github.com/tc39/ecma262/pull/1250
 @linkTimeConstant
 function resolveWithoutPromiseForAsyncAwait(resolution, onFulfilled, onRejected, context)
 {
     "use strict";

     if (@isPromise(resolution)) {
         var constructor = resolution.constructor;
         if (constructor === @Promise || constructor === @InternalPromise)
             return @performPromiseThen(resolution, onFulfilled, onRejected, @undefined, context);
     }

     return @resolveWithoutPromise(resolution, onFulfilled, onRejected, context);
 }

 @linkTimeConstant
 function createResolvingFunctionsWithoutPromise(onFulfilled, onRejected, context)
 {
     "use strict";

     var alreadyResolved = false;

     var resolve = (0, /* prevent function name inference */ (resolution) => {
         if (alreadyResolved)
             return @undefined;
         alreadyResolved = true;

         @resolveWithoutPromise(resolution, onFulfilled, onRejected, context);
     });

     var reject = (0, /* prevent function name inference */ (reason) => {
         if (alreadyResolved)
             return @undefined;
         alreadyResolved = true;

         @rejectWithoutPromise(reason, onFulfilled, onRejected, context);
     });

     return { resolve, reject };
 }

 @linkTimeConstant
 function promiseReactionJob(promiseOrCapability, handler, argument, contextOrState)
 {
     // Promise Reaction has four types.
     // 1. @promiseOrCapability is PromiseCapability, and having handlers.
     //     The most generic one.
     // 2. @promiseOrCapability is Promise, and having handlers.
     //     We just have promise.
     // 3. @promiseOrCapability is Promise, and not having handlers.
     //     It only has promise. Just resolving it with the value. contextOrState is undefined, so it delivers state instead.
     // 4. Only having @onFulfilled and @onRejected
     //     It does not have promise capability. Just handlers are passed.
     "use strict";

     // Case (3).
     if (@isUndefinedOrNull(handler)) {
         try {
             @assert(@isPromise(promiseOrCapability));
             if (contextOrState === @promiseStateFulfilled)
                 @resolvePromise(promiseOrCapability, argument);
             else
                 @rejectPromise(promiseOrCapability, argument);
         } catch {
             // This is user-uncatchable promise. We just ignore the error here.
         }
         return;
     }

     // Case (4).
     if (!promiseOrCapability) {
         @promiseReactionJobWithoutPromise(handler, argument, contextOrState);
         return;
     }

     // Case (1), or (2).
     try {
         var result = (contextOrState) ? handler(argument, contextOrState) : handler(argument);
     } catch (error) {
         if (@isPromise(promiseOrCapability)) {
             @rejectPromise(promiseOrCapability, error);
             return;
         }
         promiseOrCapability.reject.@call(@undefined, error);
         return;
     }

     if (@isPromise(promiseOrCapability)) {
         @resolvePromise(promiseOrCapability, result);
         return;
     }
     promiseOrCapability.resolve.@call(@undefined, result);
 }

 @linkTimeConstant
 function promiseResolveThenableJobFast(thenable, promiseToResolve)
 {
     "use strict";

     @assert(@isPromise(thenable));
     @assert(@isPromise(promiseToResolve));

     // Even if we are using @defaultPromiseThen, still thenable.constructor access is observable, and if it is not returning @Promise,
     // we need to call this constructor.
     var constructor = @speciesConstructor(thenable, @Promise);
     if (constructor !== @Promise && constructor !== @InternalPromise) {
         @promiseResolveThenableJobWithDerivedPromise(thenable, constructor, @createResolvingFunctions(promiseToResolve));
         return;
     }

     var flags = @getPromiseInternalField(thenable, @promiseFieldFlags);
     var state = flags & @promiseStateMask;
     var reactionsOrResult = @getPromiseInternalField(thenable, @promiseFieldReactionsOrResult);
     if (state === @promiseStatePending)
         @pushNewPromiseReaction(thenable, reactionsOrResult, promiseToResolve, @undefined, @undefined);
     else {
         if (state === @promiseStateRejected && !(flags & @promiseFlagsIsHandled))
             @hostPromiseRejectionTracker(thenable, @promiseRejectionHandle);
         @enqueueJob(@promiseReactionJob, promiseToResolve, @undefined, reactionsOrResult, state);
     }
     @putPromiseInternalField(thenable, @promiseFieldFlags, @getPromiseInternalField(thenable, @promiseFieldFlags) | @promiseFlagsIsHandled);
 }

 @linkTimeConstant
 function promiseResolveThenableJobWithoutPromiseFast(thenable, onFulfilled, onRejected, context)
 {
     "use strict";

     @assert(@isPromise(thenable));

     // Even if we are using @defaultPromiseThen, still thenable.constructor access is observable, and if it is not returning @Promise,
     // we need to call this constructor.
     var constructor = @speciesConstructor(thenable, @Promise);
     if (constructor !== @Promise && constructor !== @InternalPromise) {
         @promiseResolveThenableJobWithDerivedPromise(thenable, constructor, @createResolvingFunctionsWithoutPromise(onFulfilled, onRejected, context));
         return;
     }

     var flags = @getPromiseInternalField(thenable, @promiseFieldFlags);
     var state = flags & @promiseStateMask;
     var reactionsOrResult = @getPromiseInternalField(thenable, @promiseFieldReactionsOrResult);
     if (state === @promiseStatePending)
         @pushNewPromiseReaction(thenable, reactionsOrResult, @undefined, onFulfilled, onRejected, context);
     else {
         if (state === @promiseStateRejected) {
             if (!(flags & @promiseFlagsIsHandled))
                 @hostPromiseRejectionTracker(thenable, @promiseRejectionHandle);
             @rejectWithoutPromise(reactionsOrResult, onFulfilled, onRejected, context);
         } else
             @fulfillWithoutPromise(reactionsOrResult, onFulfilled, onRejected, context);
     }
     @putPromiseInternalField(thenable, @promiseFieldFlags, @getPromiseInternalField(thenable, @promiseFieldFlags) | @promiseFlagsIsHandled);
 }

 @linkTimeConstant
 function promiseResolveThenableJob(thenable, then, resolvingFunctions)
 {
     "use strict";

     try {
         return then.@call(thenable, resolvingFunctions.resolve, resolvingFunctions.reject);
     } catch (error) {
         return resolvingFunctions.reject.@call(@undefined, error);
     }
 }

 @linkTimeConstant
 function promiseResolveThenableJobWithDerivedPromise(thenable, constructor, resolvingFunctions)
 {
     "use strict";

     try {
         var promiseOrCapability = @newPromiseCapabilitySlow(constructor);
         @performPromiseThen(thenable, resolvingFunctions.resolve, resolvingFunctions.reject, promiseOrCapability, @undefined);
         return promiseOrCapability.promise;
     } catch (error) {
         return resolvingFunctions.reject.@call(@undefined, error);
     }
 }

 @linkTimeConstant
 function promiseEmptyOnFulfilled(argument)
 {
     "use strict";

     return argument;
 }

 @linkTimeConstant
 function promiseEmptyOnRejected(argument)
 {
     "use strict";

     throw argument;
 }

 @linkTimeConstant
 function performPromiseThen(promise, onFulfilled, onRejected, promiseOrCapability, context)
 {
     "use strict";

     if (!@isCallable(onFulfilled))
         onFulfilled = @promiseEmptyOnFulfilled;

     if (!@isCallable(onRejected))
         onRejected = @promiseEmptyOnRejected;

     var reactionsOrResult = @getPromiseInternalField(promise, @promiseFieldReactionsOrResult);
     var flags = @getPromiseInternalField(promise, @promiseFieldFlags);
     var state = flags & @promiseStateMask;
     if (state === @promiseStatePending)
         @pushNewPromiseReaction(promise, reactionsOrResult, promiseOrCapability, onFulfilled, onRejected, context);
     else {
         var handler;

         if (state === @promiseStateRejected) {
             handler = onRejected;
             if (!(flags & @promiseFlagsIsHandled))
                 @hostPromiseRejectionTracker(promise, @promiseRejectionHandle);
         } else
             handler = onFulfilled;
         @enqueueJob(@promiseReactionJob, promiseOrCapability, handler, reactionsOrResult, context);
     }
     @putPromiseInternalField(promise, @promiseFieldFlags, @getPromiseInternalField(promise, @promiseFieldFlags) | @promiseFlagsIsHandled);
 }
	/*
	* Copyright (C) 2015 Yusuke Suzuki <utatane.tea@gmail.com>.
	* Copyright (C) 2016-2019 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
	* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	// @internal

	@linkTimeConstant
	function pushNewPromiseReaction(thenable, existingReactions, promiseOrCapability, onFulfilled, onRejected, context)
	{
	"use strict";

	if (!existingReactions) {
	existingReactions = {
	@promiseOrCapability: promiseOrCapability,
	@onFulfilled: onFulfilled,
	@onRejected: onRejected,
	@context: context,
	// This is 4x the number of out of line reactions (promise, fulfill callback, reject callback, context).
	@outOfLineReactionCounts: 0,
	};
	@putPromiseInternalField(thenable, @promiseFieldReactionsOrResult, existingReactions);
	} else {
	var outOfLineReactionCounts = existingReactions.@outOfLineReactionCounts;
	@putByValDirect(existingReactions, outOfLineReactionCounts++, promiseOrCapability);
	@putByValDirect(existingReactions, outOfLineReactionCounts++, onFulfilled);
	@putByValDirect(existingReactions, outOfLineReactionCounts++, onRejected);
	@putByValDirect(existingReactions, outOfLineReactionCounts++, context);
	existingReactions.@outOfLineReactionCounts = outOfLineReactionCounts;
	}
	}

	@linkTimeConstant
	function newPromiseCapabilitySlow(constructor)
	{
	"use strict";

	var promiseCapability = {
	resolve: @undefined,
	reject: @undefined,
	promise: @undefined,
	};

	var promise = new constructor((resolve, reject) => {
	if (promiseCapability.resolve !== @undefined)
	@throwTypeError("resolve function is already set");
	if (promiseCapability.reject !== @undefined)
	@throwTypeError("reject function is already set");

	promiseCapability.resolve = resolve;
	promiseCapability.reject = reject;
	});

	if (!@isCallable(promiseCapability.resolve))
	@throwTypeError("executor did not take a resolve function");

	if (!@isCallable(promiseCapability.reject))
	@throwTypeError("executor did not take a reject function");

	promiseCapability.promise = promise;

	return promiseCapability;
	}

	@linkTimeConstant
	function newPromiseCapability(constructor)
	{
	"use strict";

	if (constructor === @Promise) {
	var promise = @newPromise();
	var capturedPromise = promise;
	function @resolve(resolution) {
	return @resolvePromiseWithFirstResolvingFunctionCallCheck(capturedPromise, resolution);
	}
	function @reject(reason) {
	return @rejectPromiseWithFirstResolvingFunctionCallCheck(capturedPromise, reason);
	}
	return { resolve: @resolve, reject: @reject, promise };
	}

	return @newPromiseCapabilitySlow(constructor);
	}

	@linkTimeConstant
	function promiseResolve(constructor, value)
	{
	"use strict";

	if (@isPromise(value) && value.constructor === constructor)
	return value;

	if (constructor === @Promise) {
	var promise = @newPromise();
	@resolvePromiseWithFirstResolvingFunctionCallCheck(promise, value);
	return promise;
	}

	return @promiseResolveSlow(constructor, value);
	}

	@linkTimeConstant
	function promiseResolveSlow(constructor, value)
	{
	"use strict";

	@assert(constructor !== @Promise);
	var promiseCapability = @newPromiseCapabilitySlow(constructor);
	promiseCapability.resolve.@call(@undefined, value);
	return promiseCapability.promise;
	}

	@linkTimeConstant
	function promiseRejectSlow(constructor, reason)
	{
	"use strict";

	@assert(constructor !== @Promise);
	var promiseCapability = @newPromiseCapabilitySlow(constructor);
	promiseCapability.reject.@call(@undefined, reason);
	return promiseCapability.promise;
	}

	@linkTimeConstant
	function newHandledRejectedPromise(error)
	{
	"use strict";
	var promise = @newPromise();
	@rejectPromiseWithFirstResolvingFunctionCallCheck(promise, error);
	@putPromiseInternalField(promise, @promiseFieldFlags, @getPromiseInternalField(promise, @promiseFieldFlags) \| @promiseFlagsIsHandled);
	return promise;
	}

	@linkTimeConstant
	function triggerPromiseReactions(state, reactions, argument)
	{
	"use strict";

	if (!reactions)
	return;

	var isResolved = state === @promiseStateFulfilled;
	var handler = isResolved ? reactions.@onFulfilled : reactions.@onRejected;

	@enqueueJob(@promiseReactionJob, reactions.@promiseOrCapability, handler, argument, handler ? reactions.@context : state);

	for (var i = 0, count = reactions.@outOfLineReactionCounts; i < count; i += 4) {
	var promise = reactions[i];
	var handler = isResolved ? reactions[i + 1] : reactions[i + 2];
	var context = reactions[i + 3];
	@enqueueJob(@promiseReactionJob, promise, handler, argument, handler ? context : state);
	}
	@assert(i === count);
	}

	@linkTimeConstant
	function resolvePromise(promise, resolution)
	{
	"use strict";

	@assert(@isPromise(promise));

	if (resolution === promise)
	return @rejectPromise(promise, @makeTypeError("Cannot resolve a promise with itself"));

	if (!@isObject(resolution))
	return @fulfillPromise(promise, resolution);

	var then;
	try {
	then = resolution.then;
	} catch (error) {
	return @rejectPromise(promise, error);
	}

	if (@isPromise(resolution) && then === @defaultPromiseThen) {
	@enqueueJob(@promiseResolveThenableJobFast, resolution, promise);
	return;
	}

	if (!@isCallable(then))
	return @fulfillPromise(promise, resolution);

	@enqueueJob(@promiseResolveThenableJob, resolution, then, @createResolvingFunctions(promise));
	}

	// Keep in sync with JSPromise::rejectedPromise.
	@linkTimeConstant
	function rejectPromise(promise, reason)
	{
	"use strict";

	@assert(@isPromise(promise));
	@assert((@getPromiseInternalField(promise, @promiseFieldFlags) & @promiseStateMask) == @promiseStatePending);

	var flags = @getPromiseInternalField(promise, @promiseFieldFlags);
	var reactions = @getPromiseInternalField(promise, @promiseFieldReactionsOrResult);
	@putPromiseInternalField(promise, @promiseFieldReactionsOrResult, reason);
	@putPromiseInternalField(promise, @promiseFieldFlags, flags \| @promiseStateRejected);

	if (!(flags & @promiseFlagsIsHandled))
	@hostPromiseRejectionTracker(promise, @promiseRejectionReject);

	@triggerPromiseReactions(@promiseStateRejected, reactions, reason);
	}

	@linkTimeConstant
	function fulfillPromise(promise, value)
	{
	"use strict";

	@assert(@isPromise(promise));
	@assert((@getPromiseInternalField(promise, @promiseFieldFlags) & @promiseStateMask) == @promiseStatePending);

	var flags = @getPromiseInternalField(promise, @promiseFieldFlags);
	var reactions = @getPromiseInternalField(promise, @promiseFieldReactionsOrResult);
	@putPromiseInternalField(promise, @promiseFieldReactionsOrResult, value);
	@putPromiseInternalField(promise, @promiseFieldFlags, flags \| @promiseStateFulfilled);

	@triggerPromiseReactions(@promiseStateFulfilled, reactions, value);
	}

	@linkTimeConstant
	function resolvePromiseWithFirstResolvingFunctionCallCheck(promise, value)
	{
	"use strict";

	@assert(@isPromise(promise));
	var flags = @getPromiseInternalField(promise, @promiseFieldFlags);
	if (flags & @promiseFlagsIsFirstResolvingFunctionCalled)
	return;
	@putPromiseInternalField(promise, @promiseFieldFlags, flags \| @promiseFlagsIsFirstResolvingFunctionCalled);
	return @resolvePromise(promise, value);
	}

	@linkTimeConstant
	function fulfillPromiseWithFirstResolvingFunctionCallCheck(promise, value)
	{
	"use strict";

	@assert(@isPromise(promise));
	var flags = @getPromiseInternalField(promise, @promiseFieldFlags);
	if (flags & @promiseFlagsIsFirstResolvingFunctionCalled)
	return;
	@putPromiseInternalField(promise, @promiseFieldFlags, flags \| @promiseFlagsIsFirstResolvingFunctionCalled);
	return @fulfillPromise(promise, value);
	}

	@linkTimeConstant
	function rejectPromiseWithFirstResolvingFunctionCallCheck(promise, reason)
	{
	"use strict";

	@assert(@isPromise(promise));
	var flags = @getPromiseInternalField(promise, @promiseFieldFlags);
	if (flags & @promiseFlagsIsFirstResolvingFunctionCalled)
	return;
	@putPromiseInternalField(promise, @promiseFieldFlags, flags \| @promiseFlagsIsFirstResolvingFunctionCalled);
	return @rejectPromise(promise, reason);
	}

	@linkTimeConstant
	function createResolvingFunctions(promise)
	{
	"use strict";
	@assert(@isPromise(promise));

	var alreadyResolved = false;

	var resolve = (0, /* prevent function name inference */ (resolution) => {
	if (alreadyResolved)
	return @undefined;
	alreadyResolved = true;

	return @resolvePromise(promise, resolution);
	});

	var reject = (0, /* prevent function name inference */ (reason) => {
	if (alreadyResolved)
	return @undefined;
	alreadyResolved = true;

	return @rejectPromise(promise, reason);
	});

	return { resolve, reject };
	}

	@linkTimeConstant
	function promiseReactionJobWithoutPromise(handler, argument, context)
	{
	"use strict";

	try {
	if (context)
	handler(argument, context);
	else
	handler(argument);
	} catch {
	// This is user-uncatchable promise. We just ignore the error here.
	}
	}

	// This function has strong guarantee that each handler function (onFulfilled and onRejected) will be called at most once.
	@linkTimeConstant
	function resolveWithoutPromise(resolution, onFulfilled, onRejected, context)
	{
	"use strict";

	if (!@isObject(resolution)) {
	@fulfillWithoutPromise(resolution, onFulfilled, onRejected, context);
	return;
	}

	var then;
	try {
	then = resolution.then;
	} catch (error) {
	@rejectWithoutPromise(error, onFulfilled, onRejected, context);
	return;
	}

	if (@isPromise(resolution) && then === @defaultPromiseThen) {
	@enqueueJob(@promiseResolveThenableJobWithoutPromiseFast, resolution, onFulfilled, onRejected, context);
	return;
	}

	if (!@isCallable(then)) {
	@fulfillWithoutPromise(resolution, onFulfilled, onRejected, context);
	return;
	}

	// Wrap onFulfilled and onRejected with @createResolvingFunctionsWithoutPromise to ensure that each function will be called at most once.
	@enqueueJob(@promiseResolveThenableJob, resolution, then, @createResolvingFunctionsWithoutPromise(onFulfilled, onRejected, context));
	}

	// This function has strong guarantee that each handler function (onFulfilled and onRejected) will be called at most once.
	@linkTimeConstant
	function rejectWithoutPromise(reason, onFulfilled, onRejected, context)
	{
	"use strict";

	@enqueueJob(@promiseReactionJobWithoutPromise, onRejected, reason, context);
	}

	// This function has strong guarantee that each handler function (onFulfilled and onRejected) will be called at most once.
	@linkTimeConstant
	function fulfillWithoutPromise(value, onFulfilled, onRejected, context)
	{
	"use strict";

	@enqueueJob(@promiseReactionJobWithoutPromise, onFulfilled, value, context);
	}

	// This function has strong guarantee that each handler function (onFulfilled and onRejected) will be called at most once.
	// This is special version of resolveWithoutPromise which skips resolution's then handling.
	// https://github.com/tc39/ecma262/pull/1250
	@linkTimeConstant
	function resolveWithoutPromiseForAsyncAwait(resolution, onFulfilled, onRejected, context)
	{
	"use strict";

	if (@isPromise(resolution)) {
	var constructor = resolution.constructor;
	if (constructor === @Promise \|\| constructor === @InternalPromise)
	return @performPromiseThen(resolution, onFulfilled, onRejected, @undefined, context);
	}

	return @resolveWithoutPromise(resolution, onFulfilled, onRejected, context);
	}

	@linkTimeConstant
	function createResolvingFunctionsWithoutPromise(onFulfilled, onRejected, context)
	{
	"use strict";

	var alreadyResolved = false;

	var resolve = (0, /* prevent function name inference */ (resolution) => {
	if (alreadyResolved)
	return @undefined;
	alreadyResolved = true;

	@resolveWithoutPromise(resolution, onFulfilled, onRejected, context);
	});

	var reject = (0, /* prevent function name inference */ (reason) => {
	if (alreadyResolved)
	return @undefined;
	alreadyResolved = true;

	@rejectWithoutPromise(reason, onFulfilled, onRejected, context);
	});

	return { resolve, reject };
	}

	@linkTimeConstant
	function promiseReactionJob(promiseOrCapability, handler, argument, contextOrState)
	{
	// Promise Reaction has four types.
	// 1. @promiseOrCapability is PromiseCapability, and having handlers.
	// The most generic one.
	// 2. @promiseOrCapability is Promise, and having handlers.
	// We just have promise.
	// 3. @promiseOrCapability is Promise, and not having handlers.
	// It only has promise. Just resolving it with the value. contextOrState is undefined, so it delivers state instead.
	// 4. Only having @onFulfilled and @onRejected
	// It does not have promise capability. Just handlers are passed.
	"use strict";

	// Case (3).
	if (@isUndefinedOrNull(handler)) {
	try {
	@assert(@isPromise(promiseOrCapability));
	if (contextOrState === @promiseStateFulfilled)
	@resolvePromise(promiseOrCapability, argument);
	else
	@rejectPromise(promiseOrCapability, argument);
	} catch {
	// This is user-uncatchable promise. We just ignore the error here.
	}
	return;
	}

	// Case (4).
	if (!promiseOrCapability) {
	@promiseReactionJobWithoutPromise(handler, argument, contextOrState);
	return;
	}

	// Case (1), or (2).
	try {
	var result = (contextOrState) ? handler(argument, contextOrState) : handler(argument);
	} catch (error) {
	if (@isPromise(promiseOrCapability)) {
	@rejectPromise(promiseOrCapability, error);
	return;
	}
	promiseOrCapability.reject.@call(@undefined, error);
	return;
	}

	if (@isPromise(promiseOrCapability)) {
	@resolvePromise(promiseOrCapability, result);
	return;
	}
	promiseOrCapability.resolve.@call(@undefined, result);
	}

	@linkTimeConstant
	function promiseResolveThenableJobFast(thenable, promiseToResolve)
	{
	"use strict";

	@assert(@isPromise(thenable));
	@assert(@isPromise(promiseToResolve));

	// Even if we are using @defaultPromiseThen, still thenable.constructor access is observable, and if it is not returning @Promise,
	// we need to call this constructor.
	var constructor = @speciesConstructor(thenable, @Promise);
	if (constructor !== @Promise && constructor !== @InternalPromise) {
	@promiseResolveThenableJobWithDerivedPromise(thenable, constructor, @createResolvingFunctions(promiseToResolve));
	return;
	}

	var flags = @getPromiseInternalField(thenable, @promiseFieldFlags);
	var state = flags & @promiseStateMask;
	var reactionsOrResult = @getPromiseInternalField(thenable, @promiseFieldReactionsOrResult);
	if (state === @promiseStatePending)
	@pushNewPromiseReaction(thenable, reactionsOrResult, promiseToResolve, @undefined, @undefined);
	else {
	if (state === @promiseStateRejected && !(flags & @promiseFlagsIsHandled))
	@hostPromiseRejectionTracker(thenable, @promiseRejectionHandle);
	@enqueueJob(@promiseReactionJob, promiseToResolve, @undefined, reactionsOrResult, state);
	}
	@putPromiseInternalField(thenable, @promiseFieldFlags, @getPromiseInternalField(thenable, @promiseFieldFlags) \| @promiseFlagsIsHandled);
	}

	@linkTimeConstant
	function promiseResolveThenableJobWithoutPromiseFast(thenable, onFulfilled, onRejected, context)
	{
	"use strict";

	@assert(@isPromise(thenable));

	// Even if we are using @defaultPromiseThen, still thenable.constructor access is observable, and if it is not returning @Promise,
	// we need to call this constructor.
	var constructor = @speciesConstructor(thenable, @Promise);
	if (constructor !== @Promise && constructor !== @InternalPromise) {
	@promiseResolveThenableJobWithDerivedPromise(thenable, constructor, @createResolvingFunctionsWithoutPromise(onFulfilled, onRejected, context));
	return;
	}

	var flags = @getPromiseInternalField(thenable, @promiseFieldFlags);
	var state = flags & @promiseStateMask;
	var reactionsOrResult = @getPromiseInternalField(thenable, @promiseFieldReactionsOrResult);
	if (state === @promiseStatePending)
	@pushNewPromiseReaction(thenable, reactionsOrResult, @undefined, onFulfilled, onRejected, context);
	else {
	if (state === @promiseStateRejected) {
	if (!(flags & @promiseFlagsIsHandled))
	@hostPromiseRejectionTracker(thenable, @promiseRejectionHandle);
	@rejectWithoutPromise(reactionsOrResult, onFulfilled, onRejected, context);
	} else
	@fulfillWithoutPromise(reactionsOrResult, onFulfilled, onRejected, context);
	}
	@putPromiseInternalField(thenable, @promiseFieldFlags, @getPromiseInternalField(thenable, @promiseFieldFlags) \| @promiseFlagsIsHandled);
	}

	@linkTimeConstant
	function promiseResolveThenableJob(thenable, then, resolvingFunctions)
	{
	"use strict";

	try {
	return then.@call(thenable, resolvingFunctions.resolve, resolvingFunctions.reject);
	} catch (error) {
	return resolvingFunctions.reject.@call(@undefined, error);
	}
	}

	@linkTimeConstant
	function promiseResolveThenableJobWithDerivedPromise(thenable, constructor, resolvingFunctions)
	{
	"use strict";

	try {
	var promiseOrCapability = @newPromiseCapabilitySlow(constructor);
	@performPromiseThen(thenable, resolvingFunctions.resolve, resolvingFunctions.reject, promiseOrCapability, @undefined);
	return promiseOrCapability.promise;
	} catch (error) {
	return resolvingFunctions.reject.@call(@undefined, error);
	}
	}

	@linkTimeConstant
	function promiseEmptyOnFulfilled(argument)
	{
	"use strict";

	return argument;
	}

	@linkTimeConstant
	function promiseEmptyOnRejected(argument)
	{
	"use strict";

	throw argument;
	}

	@linkTimeConstant
	function performPromiseThen(promise, onFulfilled, onRejected, promiseOrCapability, context)
	{
	"use strict";

	if (!@isCallable(onFulfilled))
	onFulfilled = @promiseEmptyOnFulfilled;

	if (!@isCallable(onRejected))
	onRejected = @promiseEmptyOnRejected;

	var reactionsOrResult = @getPromiseInternalField(promise, @promiseFieldReactionsOrResult);
	var flags = @getPromiseInternalField(promise, @promiseFieldFlags);
	var state = flags & @promiseStateMask;
	if (state === @promiseStatePending)
	@pushNewPromiseReaction(promise, reactionsOrResult, promiseOrCapability, onFulfilled, onRejected, context);
	else {
	var handler;

	if (state === @promiseStateRejected) {
	handler = onRejected;
	if (!(flags & @promiseFlagsIsHandled))
	@hostPromiseRejectionTracker(promise, @promiseRejectionHandle);
	} else
	handler = onFulfilled;
	@enqueueJob(@promiseReactionJob, promiseOrCapability, handler, reactionsOrResult, context);
	}
	@putPromiseInternalField(promise, @promiseFieldFlags, @getPromiseInternalField(promise, @promiseFieldFlags) \| @promiseFlagsIsHandled);
	}