2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								/*
  
						 
					
						
							
								
									
										
										
										
											2021-06-22 13:30:48 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								 *  Copyright  ( c )  2020 - 2021 ,  Andreas  Kling  < kling @ serenityos . org > 
							 
						 
					
						
							
								
									
										
										
										
											2021-04-22 22:51:19 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								 *  Copyright  ( c )  2020 - 2021 ,  Linus  Groh  < linusg @ serenityos . org > 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-03 14:16:10 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								 *  Copyright  ( c )  2021 ,  David  Tuin  < davidot @ serenityos . org > 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								 * 
							 
						 
					
						
							
								
									
										
										
										
											2021-04-22 01:24:48 -07:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								 *  SPDX - License - Identifier :  BSD - 2 - Clause 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								 */ 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Add initial support for Promises
Almost a year after first working on this, it's finally done: an
implementation of Promises for LibJS! :^)
The core functionality is working and closely following the spec [1].
I mostly took the pseudo code and transformed it into C++ - if you read
and understand it, you will know how the spec implements Promises; and
if you read the spec first, the code will look very familiar.
Implemented functions are:
- Promise() constructor
- Promise.prototype.then()
- Promise.prototype.catch()
- Promise.prototype.finally()
- Promise.resolve()
- Promise.reject()
For the tests I added a new function to test-js's global object,
runQueuedPromiseJobs(), which calls vm.run_queued_promise_jobs().
By design, queued jobs normally only run after the script was fully
executed, making it improssible to test handlers in individual test()
calls by default [2].
Subsequent commits include integrations into LibWeb and js(1) -
pretty-printing, running queued promise jobs when necessary.
This has an unusual amount of dbgln() statements, all hidden behind the
PROMISE_DEBUG flag - I'm leaving them in for now as they've been very
useful while debugging this, things can get quite complex with so many
asynchronously executed functions.
I've not extensively explored use of these APIs for promise-based
functionality in LibWeb (fetch(), Notification.requestPermission()
etc.), but we'll get there in due time.
[1]: https://tc39.es/ecma262/#sec-promise-objects
[2]: https://tc39.es/ecma262/#sec-jobs-and-job-queues
											 
										 
										
											2021-04-01 22:13:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <AK/Debug.h> 
  
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <AK/ScopeGuard.h> 
  
						 
					
						
							
								
									
										
										
										
											2020-09-27 17:24:14 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <AK/StringBuilder.h> 
  
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								# include  <LibJS/Interpreter.h> 
  
						 
					
						
							
								
									
										
										
										
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								# include  <LibJS/Runtime/AbstractOperations.h> 
  
						 
					
						
							
								
									
										
										
										
											2020-12-05 16:38:29 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/Array.h> 
  
						 
					
						
							
								
									
										
										
										
											2021-08-09 15:21:15 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/BoundFunction.h> 
  
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Implement [[Call]] and [[Construct]] internal slots properly
This patch implements:
- Spec compliant [[Call]] and [[Construct]] internal slots, as virtual
  FunctionObject::internal_{call,construct}(). These effectively replace
  the old virtual FunctionObject::{call,construct}(), but with several
  advantages:
  - Clear and consistent naming, following the object internal methods
  - Use of completions
  - internal_construct() returns an Object, and not Value! This has been
    a source of confusion for a long time, since in the spec there's
    always an Object returned but the Value return type in LibJS meant
    that this could not be fully trusted and something could screw you
    over.
  - Arguments are passed explicitly in form of a MarkedValueList,
    allowing manipulation (BoundFunction). We still put them on the
    execution context as a lot of code depends on it (VM::arguments()),
    but not from the Call() / Construct() AOs anymore, which now allows
    for bypassing them and invoking [[Call]] / [[Construct]] directly.
    Nothing but Call() / Construct() themselves do that at the moment,
    but future additions to ECMA262 or already existing web specs might.
- Spec compliant, standalone Call() and Construct() AOs: currently the
  closest we have is VM::{call,construct}(), but those try to cater to
  all the different function object subclasses at once, resulting in a
  horrible mess and calling AOs with functions they should never be
  called with; most prominently PrepareForOrdinaryCall and
  OrdinaryCallBindThis, which are only for ECMAScriptFunctionObject.
As a result this also contains an implicit optimization: we no longer
need to create a new function environment for NativeFunctions - which,
worth mentioning, is what started this whole crusade in the first place
:^)
											 
										 
										
											2021-10-08 20:37:21 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/Completion.h> 
  
						 
					
						
							
								
									
										
										
										
											2021-09-24 22:40:38 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/ECMAScriptFunctionObject.h> 
  
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/Error.h> 
  
						 
					
						
							
								
									
										
										
										
											2021-06-15 22:16:17 +03:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/FinalizationRegistry.h> 
  
						 
					
						
							
								
									
										
										
										
											2021-07-01 12:24:46 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/FunctionEnvironment.h> 
  
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/GlobalObject.h> 
  
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/IteratorOperations.h> 
  
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Add initial support for Promises
Almost a year after first working on this, it's finally done: an
implementation of Promises for LibJS! :^)
The core functionality is working and closely following the spec [1].
I mostly took the pseudo code and transformed it into C++ - if you read
and understand it, you will know how the spec implements Promises; and
if you read the spec first, the code will look very familiar.
Implemented functions are:
- Promise() constructor
- Promise.prototype.then()
- Promise.prototype.catch()
- Promise.prototype.finally()
- Promise.resolve()
- Promise.reject()
For the tests I added a new function to test-js's global object,
runQueuedPromiseJobs(), which calls vm.run_queued_promise_jobs().
By design, queued jobs normally only run after the script was fully
executed, making it improssible to test handlers in individual test()
calls by default [2].
Subsequent commits include integrations into LibWeb and js(1) -
pretty-printing, running queued promise jobs when necessary.
This has an unusual amount of dbgln() statements, all hidden behind the
PROMISE_DEBUG flag - I'm leaving them in for now as they've been very
useful while debugging this, things can get quite complex with so many
asynchronously executed functions.
I've not extensively explored use of these APIs for promise-based
functionality in LibWeb (fetch(), Notification.requestPermission()
etc.), but we'll get there in due time.
[1]: https://tc39.es/ecma262/#sec-promise-objects
[2]: https://tc39.es/ecma262/#sec-jobs-and-job-queues
											 
										 
										
											2021-04-01 22:13:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/NativeFunction.h> 
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/PromiseReaction.h> 
  
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/Reference.h> 
  
						 
					
						
							
								
									
										
										
										
											2020-09-22 16:18:51 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/Symbol.h> 
  
						 
					
						
							
								
									
										
										
										
											2021-04-24 17:56:16 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/TemporaryClearException.h> 
  
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								# include  <LibJS/Runtime/VM.h> 
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								namespace  JS  {  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-08 22:58:36 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								NonnullRefPtr < VM >  VM : : create ( OwnPtr < CustomData >  custom_data )  
						 
					
						
							
								
									
										
										
										
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								{  
						 
					
						
							
								
									
										
										
										
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								    return  adopt_ref ( * new  VM ( move ( custom_data ) ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-08 22:58:36 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								VM : : VM ( OwnPtr < CustomData >  custom_data )  
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								    :  m_heap ( * this ) 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-08 22:58:36 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    ,  m_custom_data ( move ( custom_data ) ) 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2020-09-22 16:36:33 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    m_empty_string  =  m_heap . allocate_without_global_object < PrimitiveString > ( String : : empty ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-10-22 17:43:48 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    for  ( size_t  i  =  0 ;  i  <  128 ;  + + i )  { 
							 
						 
					
						
							
								
									
										
										
										
											2020-12-06 16:55:19 +00:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        m_single_ascii_character_strings [ i ]  =  m_heap . allocate_without_global_object < PrimitiveString > ( String : : formatted ( " {:c} " ,  i ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-10-22 17:43:48 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-09-22 16:18:51 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# define __JS_ENUMERATE(SymbolName, snake_name) \ 
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    m_well_known_symbol_ # # snake_name  =  js_symbol ( * this ,  " Symbol. "  # SymbolName ,  false ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    JS_ENUMERATE_WELL_KNOWN_SYMBOLS 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								# undef __JS_ENUMERATE 
  
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								VM : : ~ VM ( )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								Interpreter &  VM : : interpreter ( )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-02-23 20:42:32 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    VERIFY ( ! m_interpreters . is_empty ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								    return  * m_interpreters . last ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								Interpreter *  VM : : interpreter_if_exists ( )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    if  ( m_interpreters . is_empty ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        return  nullptr ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    return  m_interpreters . last ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								void  VM : : push_interpreter ( Interpreter &  interpreter )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    m_interpreters . append ( & interpreter ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								void  VM : : pop_interpreter ( Interpreter &  interpreter )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-02-23 20:42:32 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    VERIFY ( ! m_interpreters . is_empty ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								    auto *  popped_interpreter  =  m_interpreters . take_last ( ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-02-23 20:42:32 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    VERIFY ( popped_interpreter  = =  & interpreter ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-09-21 13:36:32 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								VM : : InterpreterExecutionScope : : InterpreterExecutionScope ( Interpreter &  interpreter )  
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								    :  m_interpreter ( interpreter ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    m_interpreter . vm ( ) . push_interpreter ( m_interpreter ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-09-21 13:36:32 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								VM : : InterpreterExecutionScope : : ~ InterpreterExecutionScope ( )  
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    m_interpreter . vm ( ) . pop_interpreter ( m_interpreter ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-09-21 13:47:33 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								void  VM : : gather_roots ( HashTable < Cell * > &  roots )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2020-09-22 16:36:33 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    roots . set ( m_empty_string ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-10-22 17:43:48 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    for  ( auto *  string  :  m_single_ascii_character_strings ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        roots . set ( string ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-12-08 16:06:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    roots . set ( m_exception ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    if  ( m_last_value . is_cell ( ) ) 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-25 18:48:11 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        roots . set ( & m_last_value . as_cell ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-10-03 14:52:53 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    auto  gather_roots_from_execution_context_stack  =  [ & roots ] ( Vector < ExecutionContext * >  const &  stack )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        for  ( auto &  execution_context  :  stack )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            if  ( execution_context - > this_value . is_cell ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                roots . set ( & execution_context - > this_value . as_cell ( ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            for  ( auto &  argument  :  execution_context - > arguments )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                if  ( argument . is_cell ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                    roots . set ( & argument . as_cell ( ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            roots . set ( execution_context - > lexical_environment ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            roots . set ( execution_context - > variable_environment ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        } 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-03 14:52:53 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    } ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    gather_roots_from_execution_context_stack ( m_execution_context_stack ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    for  ( auto &  saved_stack  :  m_saved_execution_context_stacks ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        gather_roots_from_execution_context_stack ( saved_stack ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-22 16:18:51 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								# define __JS_ENUMERATE(SymbolName, snake_name) \ 
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    roots . set ( well_known_symbol_ # # snake_name ( ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    JS_ENUMERATE_WELL_KNOWN_SYMBOLS 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								# undef __JS_ENUMERATE 
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    for  ( auto &  symbol  :  m_global_symbol_map ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        roots . set ( symbol . value ) ; 
							 
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Add initial support for Promises
Almost a year after first working on this, it's finally done: an
implementation of Promises for LibJS! :^)
The core functionality is working and closely following the spec [1].
I mostly took the pseudo code and transformed it into C++ - if you read
and understand it, you will know how the spec implements Promises; and
if you read the spec first, the code will look very familiar.
Implemented functions are:
- Promise() constructor
- Promise.prototype.then()
- Promise.prototype.catch()
- Promise.prototype.finally()
- Promise.resolve()
- Promise.reject()
For the tests I added a new function to test-js's global object,
runQueuedPromiseJobs(), which calls vm.run_queued_promise_jobs().
By design, queued jobs normally only run after the script was fully
executed, making it improssible to test handlers in individual test()
calls by default [2].
Subsequent commits include integrations into LibWeb and js(1) -
pretty-printing, running queued promise jobs when necessary.
This has an unusual amount of dbgln() statements, all hidden behind the
PROMISE_DEBUG flag - I'm leaving them in for now as they've been very
useful while debugging this, things can get quite complex with so many
asynchronously executed functions.
I've not extensively explored use of these APIs for promise-based
functionality in LibWeb (fetch(), Notification.requestPermission()
etc.), but we'll get there in due time.
[1]: https://tc39.es/ecma262/#sec-promise-objects
[2]: https://tc39.es/ecma262/#sec-jobs-and-job-queues
											 
										 
										
											2021-04-01 22:13:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    for  ( auto *  job  :  m_promise_jobs ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        roots . set ( job ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-08-15 00:04:00 +03:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    for  ( auto *  finalization_registry  :  m_finalization_registry_cleanup_jobs ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        roots . set ( finalization_registry ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-22 16:18:51 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								Symbol *  VM : : get_global_symbol ( const  String &  description )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    auto  result  =  m_global_symbol_map . get ( description ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    if  ( result . has_value ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        return  result . value ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    auto  new_global_symbol  =  js_symbol ( * this ,  description ,  true ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    m_global_symbol_map . set ( description ,  new_global_symbol ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    return  new_global_symbol ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-21 13:47:33 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								ThrowCompletionOr < Value >  VM : : named_evaluation_if_anonymous_function ( GlobalObject &  global_object ,  ASTNode  const &  expression ,  FlyString  const &  name )  
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    // 8.3.3 Static Semantics: IsAnonymousFunctionDefinition ( expr ), https://tc39.es/ecma262/#sec-isanonymousfunctiondefinition
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    // And 8.3.5 Runtime Semantics: NamedEvaluation, https://tc39.es/ecma262/#sec-runtime-semantics-namedevaluation
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    if  ( is < FunctionExpression > ( expression ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        auto &  function  =  static_cast < FunctionExpression  const & > ( expression ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        if  ( ! function . has_name ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            return  function . instantiate_ordinary_function_expression ( interpreter ( ) ,  global_object ,  name ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        } 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    }  else  if  ( is < ClassExpression > ( expression ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        auto &  class_expression  =  static_cast < ClassExpression  const & > ( expression ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        if  ( ! class_expression . has_name ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            return  TRY ( class_expression . class_definition_evaluation ( interpreter ( ) ,  global_object ,  { } ,  name ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    auto  value  =  expression . execute ( interpreter ( ) ,  global_object ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    if  ( auto *  thrown_exception  =  exception ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        return  JS : : throw_completion ( thrown_exception - > value ( ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    return  value ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								// 13.15.5.2 Runtime Semantics: DestructuringAssignmentEvaluation, https://tc39.es/ecma262/#sec-runtime-semantics-destructuringassignmentevaluation
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								ThrowCompletionOr < void >  VM : : destructuring_assignment_evaluation ( NonnullRefPtr < BindingPattern >  const &  target ,  Value  value ,  GlobalObject &  global_object )  
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    // Note: DestructuringAssignmentEvaluation is just like BindingInitialization without an environment
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    //       And it allows member expressions. We thus trust the parser to disallow member expressions
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    //       in any non assignment binding and just call BindingInitialization with a nullptr environment
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    return  binding_initialization ( target ,  value ,  nullptr ,  global_object ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								// 8.5.2 Runtime Semantics: BindingInitialization, https://tc39.es/ecma262/#sec-runtime-semantics-bindinginitialization
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								ThrowCompletionOr < void >  VM : : binding_initialization ( FlyString  const &  target ,  Value  value ,  Environment *  environment ,  GlobalObject &  global_object )  
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    if  ( environment )  { 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-09 19:16:24 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        MUST ( environment - > initialize_binding ( global_object ,  target ,  value ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        return  { } ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    auto  reference  =  resolve_binding ( target ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-11-02 19:20:21 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    return  reference . put_value ( global_object ,  value ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								// 8.5.2 Runtime Semantics: BindingInitialization, https://tc39.es/ecma262/#sec-runtime-semantics-bindinginitialization
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								ThrowCompletionOr < void >  VM : : binding_initialization ( NonnullRefPtr < BindingPattern >  const &  target ,  Value  value ,  Environment *  environment ,  GlobalObject &  global_object )  
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    if  ( target - > kind  = =  BindingPattern : : Kind : : Object )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        TRY ( require_object_coercible ( global_object ,  value ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        TRY ( property_binding_initialization ( * target ,  value ,  environment ,  global_object ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        return  { } ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    }  else  { 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-20 08:24:54 -04:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        auto *  iterator  =  TRY ( get_iterator ( global_object ,  value ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        auto  iterator_done  =  false ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        auto  result  =  iterator_binding_initialization ( * target ,  iterator ,  iterator_done ,  environment ,  global_object ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        if  ( ! iterator_done )  { 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-20 13:36:14 -04:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            // iterator_close() always returns a Completion, which ThrowCompletionOr will interpret as a throw
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            // completion. So only return the result of iterator_close() if it is indeed a throw completion.
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            auto  completion  =  result . is_throw_completion ( )  ?  result . release_error ( )  :  normal_completion ( { } ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            if  ( completion  =  iterator_close ( * iterator ,  move ( completion ) ) ;  completion . is_error ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                return  completion . release_error ( ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        } 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-20 13:36:14 -04:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        return  result ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								// 13.15.5.3 Runtime Semantics: PropertyDestructuringAssignmentEvaluation, https://tc39.es/ecma262/#sec-runtime-semantics-propertydestructuringassignmentevaluation
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								// 14.3.3.1 Runtime Semantics: PropertyBindingInitialization, https://tc39.es/ecma262/#sec-destructuring-binding-patterns-runtime-semantics-propertybindinginitialization
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								ThrowCompletionOr < void >  VM : : property_binding_initialization ( BindingPattern  const &  binding ,  Value  value ,  Environment *  environment ,  GlobalObject &  global_object )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-10-12 19:24:57 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    auto *  object  =  TRY ( value . to_object ( global_object ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-10-24 16:19:28 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    HashTable < PropertyKey >  seen_names ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    for  ( auto &  property  :  binding . entries )  { 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-18 01:11:32 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        VERIFY ( ! property . is_elision ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-18 01:11:32 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        if  ( property . is_rest )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            Reference  assignment_target ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            if  ( auto  identifier_ptr  =  property . name . get_pointer < NonnullRefPtr < Identifier > > ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                assignment_target  =  resolve_binding ( ( * identifier_ptr ) - > string ( ) ,  environment ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            }  else  if  ( auto  member_ptr  =  property . alias . get_pointer < NonnullRefPtr < MemberExpression > > ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                assignment_target  =  ( * member_ptr ) - > to_reference ( interpreter ( ) ,  global_object ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            }  else  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                VERIFY_NOT_REACHED ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            } 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            if  ( auto *  thrown_exception  =  exception ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                return  JS : : throw_completion ( thrown_exception - > value ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            auto *  rest_object  =  Object : : create ( global_object ,  global_object . object_prototype ( ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            VERIFY ( rest_object ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            TRY ( rest_object - > copy_data_properties ( object ,  seen_names ,  global_object ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            if  ( ! environment ) 
							 
						 
					
						
							
								
									
										
										
										
											2021-11-02 19:27:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                return  assignment_target . put_value ( global_object ,  rest_object ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            else 
							 
						 
					
						
							
								
									
										
										
										
											2021-11-02 19:27:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                return  assignment_target . initialize_referenced_binding ( global_object ,  rest_object ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        } 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-10-24 16:01:24 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        PropertyKey  name ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        property . name . visit ( 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            [ & ] ( Empty )  {  VERIFY_NOT_REACHED ( ) ;  } , 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            [ & ] ( NonnullRefPtr < Identifier >  const &  identifier )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                name  =  identifier - > string ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            } , 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            [ & ] ( NonnullRefPtr < Expression >  const &  expression )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                auto  result  =  expression - > execute ( interpreter ( ) ,  global_object ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                if  ( exception ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                    return ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-16 22:20:23 +03:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                auto  name_or_error  =  result . to_property_key ( global_object ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                if  ( name_or_error . is_error ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                    return ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                name  =  name_or_error . release_value ( ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            } ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        if  ( auto *  thrown_exception  =  exception ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            return  JS : : throw_completion ( thrown_exception - > value ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        seen_names . set ( name ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        if  ( property . name . has < NonnullRefPtr < Identifier > > ( )  & &  property . alias . has < Empty > ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            // FIXME: this branch and not taking this have a lot in common we might want to unify it more (like it was before).
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            auto &  identifier  =  * property . name . get < NonnullRefPtr < Identifier > > ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            auto  reference  =  resolve_binding ( identifier . string ( ) ,  environment ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            if  ( auto *  thrown_exception  =  exception ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                return  JS : : throw_completion ( thrown_exception - > value ( ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-10-02 23:52:27 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            auto  value_to_assign  =  TRY ( object - > get ( name ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            if  ( property . initializer  & &  value_to_assign . is_undefined ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                value_to_assign  =  TRY ( named_evaluation_if_anonymous_function ( global_object ,  * property . initializer ,  identifier . string ( ) ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            if  ( ! environment ) 
							 
						 
					
						
							
								
									
										
										
										
											2021-11-02 19:20:21 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                TRY ( reference . put_value ( global_object ,  value_to_assign ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            else 
							 
						 
					
						
							
								
									
										
										
										
											2021-11-02 19:27:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                TRY ( reference . initialize_referenced_binding ( global_object ,  value_to_assign ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            continue ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        } 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        Optional < Reference >  reference_to_assign_to ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        property . alias . visit ( 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            [ & ] ( Empty )  { } , 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            [ & ] ( NonnullRefPtr < Identifier >  const &  identifier )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                reference_to_assign_to  =  resolve_binding ( identifier - > string ( ) ,  environment ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            } , 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            [ & ] ( NonnullRefPtr < BindingPattern >  const & )  { } , 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            [ & ] ( NonnullRefPtr < MemberExpression >  const &  member_expression )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                reference_to_assign_to  =  member_expression - > to_reference ( interpreter ( ) ,  global_object ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            } ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        if  ( auto *  thrown_exception  =  exception ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            return  JS : : throw_completion ( thrown_exception - > value ( ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-10-02 23:52:27 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        auto  value_to_assign  =  TRY ( object - > get ( name ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        if  ( property . initializer  & &  value_to_assign . is_undefined ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            if  ( auto *  identifier_ptr  =  property . alias . get_pointer < NonnullRefPtr < Identifier > > ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                value_to_assign  =  TRY ( named_evaluation_if_anonymous_function ( global_object ,  * property . initializer ,  ( * identifier_ptr ) - > string ( ) ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            else 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                value_to_assign  =  property . initializer - > execute ( interpreter ( ) ,  global_object ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-18 01:11:32 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            if  ( auto *  thrown_exception  =  exception ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                return  JS : : throw_completion ( thrown_exception - > value ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        } 
							 
						 
					
						
							
								
									
										
										
										
											2021-06-12 18:04:28 -07:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        if  ( auto *  binding_ptr  =  property . alias . get_pointer < NonnullRefPtr < BindingPattern > > ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            TRY ( binding_initialization ( * binding_ptr ,  value_to_assign ,  environment ,  global_object ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        }  else  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            VERIFY ( reference_to_assign_to . has_value ( ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            if  ( ! environment ) 
							 
						 
					
						
							
								
									
										
										
										
											2021-11-02 19:20:21 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                TRY ( reference_to_assign_to - > put_value ( global_object ,  value_to_assign ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            else 
							 
						 
					
						
							
								
									
										
										
										
											2021-11-02 19:27:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                TRY ( reference_to_assign_to - > initialize_referenced_binding ( global_object ,  value_to_assign ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        } 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    } 
							 
						 
					
						
							
								
									
										
										
										
											2021-06-12 18:04:28 -07:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    return  { } ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								// 13.15.5.5 Runtime Semantics: IteratorDestructuringAssignmentEvaluation, https://tc39.es/ecma262/#sec-runtime-semantics-iteratordestructuringassignmentevaluation
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								// 8.5.3 Runtime Semantics: IteratorBindingInitialization, https://tc39.es/ecma262/#sec-runtime-semantics-iteratorbindinginitialization
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								ThrowCompletionOr < void >  VM : : iterator_binding_initialization ( BindingPattern  const &  binding ,  Object *  iterator ,  bool &  iterator_done ,  Environment *  environment ,  GlobalObject &  global_object )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    // FIXME: this method is nearly identical to destructuring assignment!
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    for  ( size_t  i  =  0 ;  i  <  binding . entries . size ( ) ;  i + + )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        auto &  entry  =  binding . entries [ i ] ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        Value  value ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-06-12 18:04:28 -07:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        Optional < Reference >  assignment_target ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        entry . alias . visit ( 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            [ & ] ( Empty )  { } , 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            [ & ] ( NonnullRefPtr < Identifier >  const &  identifier )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                assignment_target  =  resolve_binding ( identifier - > string ( ) ,  environment ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            } , 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            [ & ] ( NonnullRefPtr < BindingPattern >  const & )  { } , 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            [ & ] ( NonnullRefPtr < MemberExpression >  const &  member_expression )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                assignment_target  =  member_expression - > to_reference ( interpreter ( ) ,  global_object ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            } ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        if  ( auto *  thrown_exception  =  exception ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            return  JS : : throw_completion ( thrown_exception - > value ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        if  ( entry . is_rest )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            VERIFY ( i  = =  binding . entries . size ( )  -  1 ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-10-22 01:34:06 +03:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            auto *  array  =  MUST ( Array : : create ( global_object ,  0 ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            while  ( ! iterator_done )  { 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-20 08:44:30 -04:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                auto  next_object_or_error  =  iterator_next ( * iterator ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                if  ( next_object_or_error . is_throw_completion ( ) )  { 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                    iterator_done  =  true ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-20 08:44:30 -04:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                    return  JS : : throw_completion ( next_object_or_error . release_error ( ) . value ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                } 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-20 08:44:30 -04:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                auto *  next_object  =  next_object_or_error . release_value ( ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-05-29 16:03:19 +04:30 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-10-02 23:52:27 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                auto  done_property  =  TRY ( next_object - > get ( names . done ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                if  ( done_property . to_boolean ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                    iterator_done  =  true ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                    break ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                } 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-18 01:11:32 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-10-02 23:52:27 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                auto  next_value  =  TRY ( next_object - > get ( names . value ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                array - > indexed_properties ( ) . append ( next_value ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            value  =  array ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        }  else  if  ( ! iterator_done )  { 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-20 08:44:30 -04:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            auto  next_object_or_error  =  iterator_next ( * iterator ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            if  ( next_object_or_error . is_throw_completion ( ) )  { 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                iterator_done  =  true ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-20 08:44:30 -04:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                return  JS : : throw_completion ( next_object_or_error . release_error ( ) . value ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            } 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-20 08:44:30 -04:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            auto *  next_object  =  next_object_or_error . release_value ( ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-10-02 23:52:27 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            auto  done_property  =  TRY ( next_object - > get ( names . done ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            if  ( done_property . to_boolean ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                iterator_done  =  true ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                value  =  js_undefined ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            }  else  { 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-02 23:52:27 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                auto  value_or_error  =  next_object - > get ( names . value ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                if  ( value_or_error . is_throw_completion ( ) )  { 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                    iterator_done  =  true ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-02 23:52:27 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                    return  JS : : throw_completion ( value_or_error . release_error ( ) . value ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-12-05 16:38:29 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                } 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-02 23:52:27 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                value  =  value_or_error . release_value ( ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-12-05 16:38:29 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            } 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        }  else  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            value  =  js_undefined ( ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-12-05 16:38:29 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        if  ( value . is_undefined ( )  & &  entry . initializer )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            VERIFY ( ! entry . is_rest ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            if  ( auto *  identifier_ptr  =  entry . alias . get_pointer < NonnullRefPtr < Identifier > > ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                value  =  TRY ( named_evaluation_if_anonymous_function ( global_object ,  * entry . initializer ,  ( * identifier_ptr ) - > string ( ) ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            else 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                value  =  entry . initializer - > execute ( interpreter ( ) ,  global_object ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            if  ( auto *  thrown_exception  =  exception ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								                return  JS : : throw_completion ( thrown_exception - > value ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        } 
							 
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Rewrite most of Object for spec compliance :^)
This is a huge patch, I know. In hindsight this perhaps could've been
done slightly more incremental, but I started and then fixed everything
until it worked, and here we are. I tried splitting of some completely
unrelated changes into separate commits, however. Anyway.
This is a rewrite of most of Object, and by extension large parts of
Array, Proxy, Reflect, String, TypedArray, and some other things.
What we already had worked fine for about 90% of things, but getting the
last 10% right proved to be increasingly difficult with the current code
that sort of grew organically and is only very loosely based on the
spec - this became especially obvious when we started fixing a large
number of test262 failures.
Key changes include:
- 1:1 matching function names and parameters of all object-related
  functions, to avoid ambiguity. Previously we had things like put(),
  which the spec doesn't have - as a result it wasn't always clear which
  need to be used.
- Better separation between object abstract operations and internal
  methods - the former are always the same, the latter can be overridden
  (and are therefore virtual). The internal methods (i.e. [[Foo]] in the
  spec) are now prefixed with 'internal_' for clarity - again, it was
  previously not always clear which AO a certain method represents,
  get() could've been both Get and [[Get]] (I don't know which one it
  was closer to right now).
  Note that some of the old names have been kept until all code relying
  on them is updated, but they are now simple wrappers around the
  closest matching standard abstract operation.
- Simplifications of the storage layer: functions that write values to
  storage are now prefixed with 'storage_' to make their purpose clear,
  and as they are not part of the spec they should not contain any steps
  specified by it. Much functionality is now covered by the layers above
  it and was removed (e.g. handling of accessors, attribute checks).
- PropertyAttributes has been greatly simplified, and is being replaced
  by PropertyDescriptor - a concept similar to the current
  implementation, but more aligned with the actual spec. See the commit
  message of the previous commit where it was introduced for details.
- As a bonus, and since I had to look at the spec a whole lot anyway, I
  introduced more inline comments with the exact steps from the spec -
  this makes it super easy to verify correctness.
- East-const all the things.
As a result of all of this, things are much more correct but a bit
slower now. Retaining speed wasn't a consideration at all, I have done
no profiling of the new code - there might be low hanging fruits, which
we can then harvest separately.
Special thanks to Idan for helping me with this by tracking down bugs,
updating everything outside of LibJS to work with these changes (LibWeb,
Spreadsheet, HackStudio), as well as providing countless patches to fix
regressions I introduced - there still are very few (we got it down to
5), but we also get many new passing test262 tests in return. :^)
Co-authored-by: Idan Horowitz <idan.horowitz@gmail.com>
											 
										 
										
											2021-07-04 18:14:16 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        if  ( auto *  binding_ptr  =  entry . alias . get_pointer < NonnullRefPtr < BindingPattern > > ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            TRY ( binding_initialization ( * binding_ptr ,  value ,  environment ,  global_object ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        }  else  if  ( ! entry . alias . has < Empty > ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            VERIFY ( assignment_target . has_value ( ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            if  ( ! environment ) 
							 
						 
					
						
							
								
									
										
										
										
											2021-11-02 19:20:21 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                TRY ( assignment_target - > put_value ( global_object ,  value ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								            else 
							 
						 
					
						
							
								
									
										
										
										
											2021-11-02 19:27:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								                TRY ( assignment_target - > initialize_referenced_binding ( global_object ,  value ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        } 
							 
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Rewrite most of Object for spec compliance :^)
This is a huge patch, I know. In hindsight this perhaps could've been
done slightly more incremental, but I started and then fixed everything
until it worked, and here we are. I tried splitting of some completely
unrelated changes into separate commits, however. Anyway.
This is a rewrite of most of Object, and by extension large parts of
Array, Proxy, Reflect, String, TypedArray, and some other things.
What we already had worked fine for about 90% of things, but getting the
last 10% right proved to be increasingly difficult with the current code
that sort of grew organically and is only very loosely based on the
spec - this became especially obvious when we started fixing a large
number of test262 failures.
Key changes include:
- 1:1 matching function names and parameters of all object-related
  functions, to avoid ambiguity. Previously we had things like put(),
  which the spec doesn't have - as a result it wasn't always clear which
  need to be used.
- Better separation between object abstract operations and internal
  methods - the former are always the same, the latter can be overridden
  (and are therefore virtual). The internal methods (i.e. [[Foo]] in the
  spec) are now prefixed with 'internal_' for clarity - again, it was
  previously not always clear which AO a certain method represents,
  get() could've been both Get and [[Get]] (I don't know which one it
  was closer to right now).
  Note that some of the old names have been kept until all code relying
  on them is updated, but they are now simple wrappers around the
  closest matching standard abstract operation.
- Simplifications of the storage layer: functions that write values to
  storage are now prefixed with 'storage_' to make their purpose clear,
  and as they are not part of the spec they should not contain any steps
  specified by it. Much functionality is now covered by the layers above
  it and was removed (e.g. handling of accessors, attribute checks).
- PropertyAttributes has been greatly simplified, and is being replaced
  by PropertyDescriptor - a concept similar to the current
  implementation, but more aligned with the actual spec. See the commit
  message of the previous commit where it was introduced for details.
- As a bonus, and since I had to look at the spec a whole lot anyway, I
  introduced more inline comments with the exact steps from the spec -
  this makes it super easy to verify correctness.
- East-const all the things.
As a result of all of this, things are much more correct but a bit
slower now. Retaining speed wasn't a consideration at all, I have done
no profiling of the new code - there might be low hanging fruits, which
we can then harvest separately.
Special thanks to Idan for helping me with this by tracking down bugs,
updating everything outside of LibJS to work with these changes (LibWeb,
Spreadsheet, HackStudio), as well as providing countless patches to fix
regressions I introduced - there still are very few (we got it down to
5), but we also get many new passing test262 tests in return. :^)
Co-authored-by: Idan Horowitz <idan.horowitz@gmail.com>
											 
										 
										
											2021-07-04 18:14:16 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    } 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    return  { } ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-07-02 21:54:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								// 9.1.2.1 GetIdentifierReference ( env, name, strict ), https://tc39.es/ecma262/#sec-getidentifierreference
  
						 
					
						
							
								
									
										
										
										
											2021-10-07 01:06:21 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								Reference  VM : : get_identifier_reference ( Environment *  environment ,  FlyString  name ,  bool  strict ,  size_t  hops )  
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-07-02 21:54:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    // 1. If env is the value null, then
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    if  ( ! environment )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        // a. Return the Reference Record { [[Base]]: unresolvable, [[ReferencedName]]: name, [[Strict]]: strict, [[ThisValue]]: empty }.
 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-11 19:03:38 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        return  Reference  {  Reference : : BaseType : : Unresolvable ,  move ( name ) ,  strict  } ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-07-02 21:54:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    } 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-07 00:16:37 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    Optional < size_t >  index ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-09 17:07:32 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    auto  exists  =  TRY_OR_DISCARD ( environment - > has_binding ( name ,  & index ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-07-02 21:54:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-10-07 01:06:21 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    Optional < EnvironmentCoordinate >  environment_coordinate ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    if  ( index . has_value ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        environment_coordinate  =  EnvironmentCoordinate  {  . hops  =  hops ,  . index  =  index . value ( )  } ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    if  ( exists ) 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-07 01:06:21 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        return  Reference  {  * environment ,  move ( name ) ,  strict ,  environment_coordinate  } ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-09-22 12:44:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    else 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-07 01:06:21 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        return  get_identifier_reference ( environment - > outer_environment ( ) ,  move ( name ) ,  strict ,  hops  +  1 ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-07-02 21:54:56 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								// 9.4.2 ResolveBinding ( name [ , env ] ), https://tc39.es/ecma262/#sec-resolvebinding
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								Reference  VM : : resolve_binding ( FlyString  const &  name ,  Environment *  environment )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    // 1. If env is not present or if env is undefined, then
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    if  ( ! environment )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        // a. Set env to the running execution context's LexicalEnvironment.
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        environment  =  running_execution_context ( ) . lexical_environment ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    // 2. Assert: env is an Environment Record.
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    VERIFY ( environment ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    // 3. If the code matching the syntactic production that is being evaluated is contained in strict mode code, let strict be true; else let strict be false.
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    bool  strict  =  in_strict_mode ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    // 4. Return ? GetIdentifierReference(env, name, strict).
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    return  get_identifier_reference ( environment ,  name ,  strict ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-08-28 17:11:05 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								// 7.3.32 InitializeInstanceElements ( O, constructor ), https://tc39.es/ecma262/#sec-initializeinstanceelements
  
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Implement [[Call]] and [[Construct]] internal slots properly
This patch implements:
- Spec compliant [[Call]] and [[Construct]] internal slots, as virtual
  FunctionObject::internal_{call,construct}(). These effectively replace
  the old virtual FunctionObject::{call,construct}(), but with several
  advantages:
  - Clear and consistent naming, following the object internal methods
  - Use of completions
  - internal_construct() returns an Object, and not Value! This has been
    a source of confusion for a long time, since in the spec there's
    always an Object returned but the Value return type in LibJS meant
    that this could not be fully trusted and something could screw you
    over.
  - Arguments are passed explicitly in form of a MarkedValueList,
    allowing manipulation (BoundFunction). We still put them on the
    execution context as a lot of code depends on it (VM::arguments()),
    but not from the Call() / Construct() AOs anymore, which now allows
    for bypassing them and invoking [[Call]] / [[Construct]] directly.
    Nothing but Call() / Construct() themselves do that at the moment,
    but future additions to ECMA262 or already existing web specs might.
- Spec compliant, standalone Call() and Construct() AOs: currently the
  closest we have is VM::{call,construct}(), but those try to cater to
  all the different function object subclasses at once, resulting in a
  horrible mess and calling AOs with functions they should never be
  called with; most prominently PrepareForOrdinaryCall and
  OrdinaryCallBindThis, which are only for ECMAScriptFunctionObject.
As a result this also contains an implicit optimization: we no longer
need to create a new function environment for NativeFunctions - which,
worth mentioning, is what started this whole crusade in the first place
:^)
											 
										 
										
											2021-10-08 20:37:21 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								ThrowCompletionOr < void >  VM : : initialize_instance_elements ( Object &  object ,  ECMAScriptFunctionObject &  constructor )  
						 
					
						
							
								
									
										
										
										
											2021-08-28 17:11:05 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-10-12 22:45:52 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    for  ( auto &  method  :  constructor . private_methods ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        TRY ( object . private_method_or_accessor_add ( method ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    for  ( auto &  field  :  constructor . fields ( ) ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        TRY ( object . define_field ( field . name ,  field . initializer ) ) ; 
							 
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Implement [[Call]] and [[Construct]] internal slots properly
This patch implements:
- Spec compliant [[Call]] and [[Construct]] internal slots, as virtual
  FunctionObject::internal_{call,construct}(). These effectively replace
  the old virtual FunctionObject::{call,construct}(), but with several
  advantages:
  - Clear and consistent naming, following the object internal methods
  - Use of completions
  - internal_construct() returns an Object, and not Value! This has been
    a source of confusion for a long time, since in the spec there's
    always an Object returned but the Value return type in LibJS meant
    that this could not be fully trusted and something could screw you
    over.
  - Arguments are passed explicitly in form of a MarkedValueList,
    allowing manipulation (BoundFunction). We still put them on the
    execution context as a lot of code depends on it (VM::arguments()),
    but not from the Call() / Construct() AOs anymore, which now allows
    for bypassing them and invoking [[Call]] / [[Construct]] directly.
    Nothing but Call() / Construct() themselves do that at the moment,
    but future additions to ECMA262 or already existing web specs might.
- Spec compliant, standalone Call() and Construct() AOs: currently the
  closest we have is VM::{call,construct}(), but those try to cater to
  all the different function object subclasses at once, resulting in a
  horrible mess and calling AOs with functions they should never be
  called with; most prominently PrepareForOrdinaryCall and
  OrdinaryCallBindThis, which are only for ECMAScriptFunctionObject.
As a result this also contains an implicit optimization: we no longer
need to create a new function environment for NativeFunctions - which,
worth mentioning, is what started this whole crusade in the first place
:^)
											 
										 
										
											2021-10-08 20:37:21 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    return  { } ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-08-28 17:11:05 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-04-13 01:02:38 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								void  VM : : throw_exception ( Exception &  exception )  
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-04-13 01:02:38 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    set_exception ( exception ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    unwind ( ScopeType : : Try ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-06-25 11:40:03 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								// 9.4.4 ResolveThisBinding ( ), https://tc39.es/ecma262/#sec-resolvethisbinding
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								Value  VM : : resolve_this_binding ( GlobalObject &  global_object )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    auto &  environment  =  get_this_environment ( * this ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-09 16:52:34 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    return  TRY_OR_DISCARD ( environment . get_this_binding ( global_object ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-06-25 11:40:03 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-04-18 17:08:14 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								String  VM : : join_arguments ( size_t  start_index )  const  
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    StringBuilder  joined_arguments ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-04-18 17:08:14 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    for  ( size_t  i  =  start_index ;  i  <  argument_count ( ) ;  + + i )  { 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        joined_arguments . append ( argument ( i ) . to_string_without_side_effects ( ) . characters ( ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        if  ( i  ! =  argument_count ( )  -  1 ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            joined_arguments . append ( '   ' ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    return  joined_arguments . build ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-06-22 13:30:48 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								Value  VM : : get_new_target ( )  
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-06-22 13:30:48 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    auto &  env  =  get_this_environment ( * this ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-07-01 12:24:46 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    return  verify_cast < FunctionEnvironment > ( env ) . new_target ( ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 15:18:55 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Implement [[Call]] and [[Construct]] internal slots properly
This patch implements:
- Spec compliant [[Call]] and [[Construct]] internal slots, as virtual
  FunctionObject::internal_{call,construct}(). These effectively replace
  the old virtual FunctionObject::{call,construct}(), but with several
  advantages:
  - Clear and consistent naming, following the object internal methods
  - Use of completions
  - internal_construct() returns an Object, and not Value! This has been
    a source of confusion for a long time, since in the spec there's
    always an Object returned but the Value return type in LibJS meant
    that this could not be fully trusted and something could screw you
    over.
  - Arguments are passed explicitly in form of a MarkedValueList,
    allowing manipulation (BoundFunction). We still put them on the
    execution context as a lot of code depends on it (VM::arguments()),
    but not from the Call() / Construct() AOs anymore, which now allows
    for bypassing them and invoking [[Call]] / [[Construct]] directly.
    Nothing but Call() / Construct() themselves do that at the moment,
    but future additions to ECMA262 or already existing web specs might.
- Spec compliant, standalone Call() and Construct() AOs: currently the
  closest we have is VM::{call,construct}(), but those try to cater to
  all the different function object subclasses at once, resulting in a
  horrible mess and calling AOs with functions they should never be
  called with; most prominently PrepareForOrdinaryCall and
  OrdinaryCallBindThis, which are only for ECMAScriptFunctionObject.
As a result this also contains an implicit optimization: we no longer
need to create a new function environment for NativeFunctions - which,
worth mentioning, is what started this whole crusade in the first place
:^)
											 
										 
										
											2021-10-08 20:37:21 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								// NOTE: This is only here because there's a million invocations of vm.call() - it used to be tied to the VM in weird ways.
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								// We should update all of those and then remove this, along with the call() template functions in VM.h, and use the standalone call() AO.
  
						 
					
						
							
								
									
										
										
										
											2021-09-23 20:56:28 +03:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								ThrowCompletionOr < Value >  VM : : call_internal ( FunctionObject &  function ,  Value  this_value ,  Optional < MarkedValueList >  arguments )  
						 
					
						
							
								
									
										
										
										
											2020-09-27 17:24:14 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-02-23 20:42:32 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    VERIFY ( ! exception ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-03-26 19:40:55 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    VERIFY ( ! this_value . is_empty ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 17:24:14 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Implement [[Call]] and [[Construct]] internal slots properly
This patch implements:
- Spec compliant [[Call]] and [[Construct]] internal slots, as virtual
  FunctionObject::internal_{call,construct}(). These effectively replace
  the old virtual FunctionObject::{call,construct}(), but with several
  advantages:
  - Clear and consistent naming, following the object internal methods
  - Use of completions
  - internal_construct() returns an Object, and not Value! This has been
    a source of confusion for a long time, since in the spec there's
    always an Object returned but the Value return type in LibJS meant
    that this could not be fully trusted and something could screw you
    over.
  - Arguments are passed explicitly in form of a MarkedValueList,
    allowing manipulation (BoundFunction). We still put them on the
    execution context as a lot of code depends on it (VM::arguments()),
    but not from the Call() / Construct() AOs anymore, which now allows
    for bypassing them and invoking [[Call]] / [[Construct]] directly.
    Nothing but Call() / Construct() themselves do that at the moment,
    but future additions to ECMA262 or already existing web specs might.
- Spec compliant, standalone Call() and Construct() AOs: currently the
  closest we have is VM::{call,construct}(), but those try to cater to
  all the different function object subclasses at once, resulting in a
  horrible mess and calling AOs with functions they should never be
  called with; most prominently PrepareForOrdinaryCall and
  OrdinaryCallBindThis, which are only for ECMAScriptFunctionObject.
As a result this also contains an implicit optimization: we no longer
need to create a new function environment for NativeFunctions - which,
worth mentioning, is what started this whole crusade in the first place
:^)
											 
										 
										
											2021-10-08 20:37:21 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    return  JS : : call_impl ( function . global_object ( ) ,  & function ,  this_value ,  move ( arguments ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-09-27 17:24:14 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-10-04 13:54:44 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								bool  VM : : in_strict_mode ( )  const  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-06-24 19:17:45 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    if  ( execution_context_stack ( ) . is_empty ( ) ) 
							 
						 
					
						
							
								
									
										
										
										
											2020-10-04 13:54:44 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        return  false ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-06-24 19:17:45 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    return  running_execution_context ( ) . is_strict_mode ; 
							 
						 
					
						
							
								
									
										
										
										
											2020-10-04 13:54:44 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Add initial support for Promises
Almost a year after first working on this, it's finally done: an
implementation of Promises for LibJS! :^)
The core functionality is working and closely following the spec [1].
I mostly took the pseudo code and transformed it into C++ - if you read
and understand it, you will know how the spec implements Promises; and
if you read the spec first, the code will look very familiar.
Implemented functions are:
- Promise() constructor
- Promise.prototype.then()
- Promise.prototype.catch()
- Promise.prototype.finally()
- Promise.resolve()
- Promise.reject()
For the tests I added a new function to test-js's global object,
runQueuedPromiseJobs(), which calls vm.run_queued_promise_jobs().
By design, queued jobs normally only run after the script was fully
executed, making it improssible to test handlers in individual test()
calls by default [2].
Subsequent commits include integrations into LibWeb and js(1) -
pretty-printing, running queued promise jobs when necessary.
This has an unusual amount of dbgln() statements, all hidden behind the
PROMISE_DEBUG flag - I'm leaving them in for now as they've been very
useful while debugging this, things can get quite complex with so many
asynchronously executed functions.
I've not extensively explored use of these APIs for promise-based
functionality in LibWeb (fetch(), Notification.requestPermission()
etc.), but we'll get there in due time.
[1]: https://tc39.es/ecma262/#sec-promise-objects
[2]: https://tc39.es/ecma262/#sec-jobs-and-job-queues
											 
										 
										
											2021-04-01 22:13:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								void  VM : : run_queued_promise_jobs ( )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    dbgln_if ( PROMISE_DEBUG ,  " Running queued promise jobs " ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    // Temporarily get rid of the exception, if any - job functions must be called
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    // either way, and that can't happen if we already have an exception stored.
 
							 
						 
					
						
							
								
									
										
										
										
											2021-04-24 17:56:16 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    TemporaryClearException  clear_exception ( * this ) ; 
							 
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Add initial support for Promises
Almost a year after first working on this, it's finally done: an
implementation of Promises for LibJS! :^)
The core functionality is working and closely following the spec [1].
I mostly took the pseudo code and transformed it into C++ - if you read
and understand it, you will know how the spec implements Promises; and
if you read the spec first, the code will look very familiar.
Implemented functions are:
- Promise() constructor
- Promise.prototype.then()
- Promise.prototype.catch()
- Promise.prototype.finally()
- Promise.resolve()
- Promise.reject()
For the tests I added a new function to test-js's global object,
runQueuedPromiseJobs(), which calls vm.run_queued_promise_jobs().
By design, queued jobs normally only run after the script was fully
executed, making it improssible to test handlers in individual test()
calls by default [2].
Subsequent commits include integrations into LibWeb and js(1) -
pretty-printing, running queued promise jobs when necessary.
This has an unusual amount of dbgln() statements, all hidden behind the
PROMISE_DEBUG flag - I'm leaving them in for now as they've been very
useful while debugging this, things can get quite complex with so many
asynchronously executed functions.
I've not extensively explored use of these APIs for promise-based
functionality in LibWeb (fetch(), Notification.requestPermission()
etc.), but we'll get there in due time.
[1]: https://tc39.es/ecma262/#sec-promise-objects
[2]: https://tc39.es/ecma262/#sec-jobs-and-job-queues
											 
										 
										
											2021-04-01 22:13:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    while  ( ! m_promise_jobs . is_empty ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        auto *  job  =  m_promise_jobs . take_first ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        dbgln_if ( PROMISE_DEBUG ,  " Calling promise job function @ {} " ,  job ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-11 22:19:46 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        // NOTE: If the execution context stack is empty, we make and push a temporary context.
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        ExecutionContext  execution_context ( heap ( ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        bool  pushed_execution_context  =  false ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        if  ( m_execution_context_stack . is_empty ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            static  FlyString  promise_execution_context_name  =  " (promise execution context) " ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            execution_context . function_name  =  promise_execution_context_name ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            push_execution_context ( execution_context ,  job - > global_object ( ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            pushed_execution_context  =  true ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Add initial support for Promises
Almost a year after first working on this, it's finally done: an
implementation of Promises for LibJS! :^)
The core functionality is working and closely following the spec [1].
I mostly took the pseudo code and transformed it into C++ - if you read
and understand it, you will know how the spec implements Promises; and
if you read the spec first, the code will look very familiar.
Implemented functions are:
- Promise() constructor
- Promise.prototype.then()
- Promise.prototype.catch()
- Promise.prototype.finally()
- Promise.resolve()
- Promise.reject()
For the tests I added a new function to test-js's global object,
runQueuedPromiseJobs(), which calls vm.run_queued_promise_jobs().
By design, queued jobs normally only run after the script was fully
executed, making it improssible to test handlers in individual test()
calls by default [2].
Subsequent commits include integrations into LibWeb and js(1) -
pretty-printing, running queued promise jobs when necessary.
This has an unusual amount of dbgln() statements, all hidden behind the
PROMISE_DEBUG flag - I'm leaving them in for now as they've been very
useful while debugging this, things can get quite complex with so many
asynchronously executed functions.
I've not extensively explored use of these APIs for promise-based
functionality in LibWeb (fetch(), Notification.requestPermission()
etc.), but we'll get there in due time.
[1]: https://tc39.es/ecma262/#sec-promise-objects
[2]: https://tc39.es/ecma262/#sec-jobs-and-job-queues
											 
										 
										
											2021-04-01 22:13:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								        [[maybe_unused]]  auto  result  =  call ( * job ,  js_undefined ( ) ) ; 
							 
						 
					
						
							
								
									
										
										
										
											2021-10-11 22:19:46 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        if  ( pushed_execution_context ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            pop_execution_context ( ) ; 
							 
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Add initial support for Promises
Almost a year after first working on this, it's finally done: an
implementation of Promises for LibJS! :^)
The core functionality is working and closely following the spec [1].
I mostly took the pseudo code and transformed it into C++ - if you read
and understand it, you will know how the spec implements Promises; and
if you read the spec first, the code will look very familiar.
Implemented functions are:
- Promise() constructor
- Promise.prototype.then()
- Promise.prototype.catch()
- Promise.prototype.finally()
- Promise.resolve()
- Promise.reject()
For the tests I added a new function to test-js's global object,
runQueuedPromiseJobs(), which calls vm.run_queued_promise_jobs().
By design, queued jobs normally only run after the script was fully
executed, making it improssible to test handlers in individual test()
calls by default [2].
Subsequent commits include integrations into LibWeb and js(1) -
pretty-printing, running queued promise jobs when necessary.
This has an unusual amount of dbgln() statements, all hidden behind the
PROMISE_DEBUG flag - I'm leaving them in for now as they've been very
useful while debugging this, things can get quite complex with so many
asynchronously executed functions.
I've not extensively explored use of these APIs for promise-based
functionality in LibWeb (fetch(), Notification.requestPermission()
etc.), but we'll get there in due time.
[1]: https://tc39.es/ecma262/#sec-promise-objects
[2]: https://tc39.es/ecma262/#sec-jobs-and-job-queues
											 
										 
										
											2021-04-01 22:13:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    // Ensure no job has created a new exception, they must clean up after themselves.
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    VERIFY ( ! m_exception ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-06-13 00:22:35 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								// 9.5.4 HostEnqueuePromiseJob ( job, realm ), https://tc39.es/ecma262/#sec-hostenqueuepromisejob
  
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Add initial support for Promises
Almost a year after first working on this, it's finally done: an
implementation of Promises for LibJS! :^)
The core functionality is working and closely following the spec [1].
I mostly took the pseudo code and transformed it into C++ - if you read
and understand it, you will know how the spec implements Promises; and
if you read the spec first, the code will look very familiar.
Implemented functions are:
- Promise() constructor
- Promise.prototype.then()
- Promise.prototype.catch()
- Promise.prototype.finally()
- Promise.resolve()
- Promise.reject()
For the tests I added a new function to test-js's global object,
runQueuedPromiseJobs(), which calls vm.run_queued_promise_jobs().
By design, queued jobs normally only run after the script was fully
executed, making it improssible to test handlers in individual test()
calls by default [2].
Subsequent commits include integrations into LibWeb and js(1) -
pretty-printing, running queued promise jobs when necessary.
This has an unusual amount of dbgln() statements, all hidden behind the
PROMISE_DEBUG flag - I'm leaving them in for now as they've been very
useful while debugging this, things can get quite complex with so many
asynchronously executed functions.
I've not extensively explored use of these APIs for promise-based
functionality in LibWeb (fetch(), Notification.requestPermission()
etc.), but we'll get there in due time.
[1]: https://tc39.es/ecma262/#sec-promise-objects
[2]: https://tc39.es/ecma262/#sec-jobs-and-job-queues
											 
										 
										
											2021-04-01 22:13:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								void  VM : : enqueue_promise_job ( NativeFunction &  job )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    m_promise_jobs . append ( & job ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-06-15 22:16:17 +03:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								void  VM : : run_queued_finalization_registry_cleanup_jobs ( )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    while  ( ! m_finalization_registry_cleanup_jobs . is_empty ( ) )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        auto *  registry  =  m_finalization_registry_cleanup_jobs . take_first ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        registry - > cleanup ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								// 9.10.4.1 HostEnqueueFinalizationRegistryCleanupJob ( finalizationRegistry ), https://tc39.es/ecma262/#sec-host-cleanup-finalization-registry
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								void  VM : : enqueue_finalization_registry_cleanup_job ( FinalizationRegistry &  registry )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    m_finalization_registry_cleanup_jobs . append ( & registry ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-06-13 00:22:35 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								// 27.2.1.9 HostPromiseRejectionTracker ( promise, operation ), https://tc39.es/ecma262/#sec-host-promise-rejection-tracker
  
						 
					
						
							
								
									
										
											 
										
											
												LibJS: Add initial support for Promises
Almost a year after first working on this, it's finally done: an
implementation of Promises for LibJS! :^)
The core functionality is working and closely following the spec [1].
I mostly took the pseudo code and transformed it into C++ - if you read
and understand it, you will know how the spec implements Promises; and
if you read the spec first, the code will look very familiar.
Implemented functions are:
- Promise() constructor
- Promise.prototype.then()
- Promise.prototype.catch()
- Promise.prototype.finally()
- Promise.resolve()
- Promise.reject()
For the tests I added a new function to test-js's global object,
runQueuedPromiseJobs(), which calls vm.run_queued_promise_jobs().
By design, queued jobs normally only run after the script was fully
executed, making it improssible to test handlers in individual test()
calls by default [2].
Subsequent commits include integrations into LibWeb and js(1) -
pretty-printing, running queued promise jobs when necessary.
This has an unusual amount of dbgln() statements, all hidden behind the
PROMISE_DEBUG flag - I'm leaving them in for now as they've been very
useful while debugging this, things can get quite complex with so many
asynchronously executed functions.
I've not extensively explored use of these APIs for promise-based
functionality in LibWeb (fetch(), Notification.requestPermission()
etc.), but we'll get there in due time.
[1]: https://tc39.es/ecma262/#sec-promise-objects
[2]: https://tc39.es/ecma262/#sec-jobs-and-job-queues
											 
										 
										
											2021-04-01 22:13:29 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								void  VM : : promise_rejection_tracker ( const  Promise &  promise ,  Promise : : RejectionOperation  operation )  const  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    switch  ( operation )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    case  Promise : : RejectionOperation : : Reject : 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        // A promise was rejected without any handlers
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        if  ( on_promise_unhandled_rejection ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            on_promise_unhandled_rejection ( promise ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        break ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    case  Promise : : RejectionOperation : : Handle : 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        // A handler was added to an already rejected promise
 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        if  ( on_promise_rejection_handled ) 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            on_promise_rejection_handled ( promise ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        break ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    default : 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        VERIFY_NOT_REACHED ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-06-06 22:53:44 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								void  VM : : dump_backtrace ( )  const  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
									
										
										
										
											2021-09-11 17:01:19 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								    for  ( ssize_t  i  =  m_execution_context_stack . size ( )  -  1 ;  i  > =  0 ;  - - i )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        auto &  frame  =  m_execution_context_stack [ i ] ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        if  ( frame - > current_node )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            auto &  source_range  =  frame - > current_node - > source_range ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            dbgln ( " -> {} @ {}:{},{} " ,  frame - > function_name ,  source_range . filename ,  source_range . start . line ,  source_range . start . column ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        }  else  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								            dbgln ( " -> {} " ,  frame - > function_name ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								        } 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    } 
							 
						 
					
						
							
								
									
										
										
										
											2021-06-06 22:53:44 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-09-08 22:58:36 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								VM : : CustomData : : ~ CustomData ( )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-10-03 14:52:53 +02:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								void  VM : : save_execution_context_stack ( )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    m_saved_execution_context_stacks . append ( move ( m_execution_context_stack ) ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								void  VM : : restore_execution_context_stack ( )  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								{  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    m_execution_context_stack  =  m_saved_execution_context_stacks . take_last ( ) ; 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-09-20 19:24:44 +02:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								}