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Move DisposeResources to Evaluation of FunctionStatementList (#178)
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@rbuckton
rbuckton committed Mar 20, 2024
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Expand Up @@ -3097,25 +3097,6 @@ contributors: Ron Buckton, Ecma International
<emu-clause id="sec-function-definitions">
<h1>Function Definitions</h1>

<emu-clause id="sec-runtime-semantics-evaluatefunctionbody" oldids="sec-function-definitions-runtime-semantics-evaluatebody" type="sdo">
<h1>
Runtime Semantics: EvaluateFunctionBody (
_functionObject_: unknown,
_argumentsList_: a List,
): either a normal completion containing an ECMAScript language value or an abrupt completion
</h1>
<dl class="header">
</dl>
<emu-grammar>FunctionBody : FunctionStatementList</emu-grammar>
<emu-alg>
1. Perform ? FunctionDeclarationInstantiation(_functionObject_, _argumentsList_).
1. <del>Return ? Evaluation of |FunctionStatementList|.</del>
1. <ins>Let _result_ be Completion(Evaluation of |FunctionStatementList|).</ins>
1. <ins>Let _env_ be the running execution context's LexicalEnvironment.</ins>
1. <ins>Return ? DisposeResources(_env_.[[DisposeCapability]], _result_).</ins>
</emu-alg>
</emu-clause>

<emu-clause id="sec-runtime-semantics-instantiateordinaryfunctionexpression" type="sdo">
<h1>
Runtime Semantics: InstantiateOrdinaryFunctionExpression (
Expand Down Expand Up @@ -3154,6 +3135,43 @@ contributors: Ron Buckton, Ecma International
<p>The |BindingIdentifier| in a |FunctionExpression| can be referenced from inside the |FunctionExpression|'s |FunctionBody| to allow the function to call itself recursively. However, unlike in a |FunctionDeclaration|, the |BindingIdentifier| in a |FunctionExpression| cannot be referenced from and does not affect the scope enclosing the |FunctionExpression|.</p>
</emu-note>
</emu-clause>

<emu-clause id="sec-function-definitions-runtime-semantics-evaluation" type="sdo">
<h1>Runtime Semantics: Evaluation</h1>
<emu-grammar>FunctionDeclaration : `function` BindingIdentifier `(` FormalParameters `)` `{` FunctionBody `}`</emu-grammar>
<emu-alg>
1. Return ~empty~.
</emu-alg>
<emu-note>
<p>An alternative semantics is provided in <emu-xref href="#sec-block-level-function-declarations-web-legacy-compatibility-semantics"></emu-xref>.</p>
</emu-note>
<emu-grammar>FunctionDeclaration : `function` `(` FormalParameters `)` `{` FunctionBody `}`</emu-grammar>
<emu-alg>
1. Return ~empty~.
</emu-alg>
<emu-grammar>
FunctionExpression : `function` BindingIdentifier? `(` FormalParameters `)` `{` FunctionBody `}`
</emu-grammar>
<emu-alg>
1. Return InstantiateOrdinaryFunctionExpression of |FunctionExpression|.
</emu-alg>
<emu-note>
<p>A *"prototype"* property is automatically created for every function defined using a |FunctionDeclaration| or |FunctionExpression|, to allow for the possibility that the function will be used as a constructor.</p>
</emu-note>
<emu-grammar>FunctionStatementList : [empty]</emu-grammar>
<emu-alg>
1. Return *undefined*.
</emu-alg>
<ins class="block">
<emu-grammar>FunctionStatementList : StatementList</emu-grammar>
<emu-alg>
1. Let _result_ be Completion(Evaluation of |StatementList|).
1. Let _env_ be the running execution context's LexicalEnvironment.
1. Assert: _env_ is a Declarative Environment Record.
1. Return ? DisposeResources(_env_.[[DisposeCapability]], _result_).
</emu-alg>
</ins>
</emu-clause>
</emu-clause>

<emu-clause id="sec-generator-function-definitions">
Expand Down Expand Up @@ -4813,138 +4831,6 @@ contributors: Ron Buckton, Ecma International
</emu-clause>
</emu-clause>
</ins>

<emu-clause id="sec-generator-objects">
<h1>Generator Objects</h1>

<emu-clause id="sec-generator-abstract-operations">
<h1>Generator Abstract Operations</h1>

<emu-clause id="sec-generatorstart" type="abstract operation">
<h1>
GeneratorStart (
_generator_: unknown,
_generatorBody_: a |FunctionBody| Parse Node or an Abstract Closure with no parameters,
): ~unused~
</h1>
<dl class="header">
</dl>
<emu-alg>
1. Assert: The value of _generator_.[[GeneratorState]] is *undefined*.
1. Let _genContext_ be the running execution context.
1. Set the Generator component of _genContext_ to _generator_.
1. [fence-effects="user-code"] Set the code evaluation state of _genContext_ such that when evaluation is resumed for that execution context the following steps will be performed:
1. If _generatorBody_ is a Parse Node, then
1. Let _result_ be the result of evaluating _generatorBody_.
1. Else,
1. Assert: _generatorBody_ is an Abstract Closure with no parameters.
1. Let _result_ be _generatorBody_().
1. Assert: If we return here, the generator either threw an exception or performed either an implicit or explicit return.
1. Remove _genContext_ from the execution context stack and restore the execution context that is at the top of the execution context stack as the running execution context.
1. Set _generator_.[[GeneratorState]] to ~completed~.
1. Once a generator enters the ~completed~ state it never leaves it and its associated execution context is never resumed. Any execution state associated with _generator_ can be discarded at this point.
1. <ins>Let _env_ be _genContext_'s LexicalEnvironment.</ins>
1. <ins>Set _result_ to DisposeResources(_env_.[[DisposeCapability]], _result_).</ins>
1. If _result_.[[Type]] is ~normal~, let _resultValue_ be *undefined*.
1. Else if _result_.[[Type]] is ~return~, let _resultValue_ be _result_.[[Value]].
1. Else,
1. Assert: _result_.[[Type]] is ~throw~.
1. Return ? _result_.
1. Return CreateIterResultObject(_resultValue_, *true*).
1. Set _generator_.[[GeneratorContext]] to _genContext_.
1. Set _generator_.[[GeneratorState]] to ~suspendedStart~.
1. Return ~unused~.
</emu-alg>
</emu-clause>
</emu-clause>
</emu-clause>

<emu-clause id="sec-asyncgenerator-objects">
<h1>AsyncGenerator Objects</h1>

<emu-clause id="sec-asyncgenerator-abstract-operations">
<h1>AsyncGenerator Abstract Operations</h1>

<emu-clause id="sec-asyncgeneratorstart" type="abstract operation">
<h1>
AsyncGeneratorStart (
_generator_: an AsyncGenerator,
_generatorBody_: a |FunctionBody| Parse Node or an Abstract Closure with no parameters,
): ~unused~
</h1>
<dl class="header">
</dl>
<emu-alg>
1. Assert: _generator_.[[AsyncGeneratorState]] is *undefined*.
1. Let _genContext_ be the running execution context.
1. Set the Generator component of _genContext_ to _generator_.
1. [fence-effects="user-code"] Set the code evaluation state of _genContext_ such that when evaluation is resumed for that execution context the following steps will be performed:
1. If _generatorBody_ is a Parse Node, then
1. Let _result_ be the result of evaluating _generatorBody_.
1. Else,
1. Assert: _generatorBody_ is an Abstract Closure with no parameters.
1. Let _result_ be Completion(_generatorBody_()).
1. Assert: If we return here, the async generator either threw an exception or performed either an implicit or explicit return.
1. Remove _genContext_ from the execution context stack and restore the execution context that is at the top of the execution context stack as the running execution context.
1. Set _generator_.[[AsyncGeneratorState]] to ~completed~.
1. <ins>Let _env_ be _genContext_'s LexicalEnvironment.</ins>
1. <ins>Set _result_ to DisposeResources(_env_.[[DisposeCapability]], _result_).</ins>
1. If _result_.[[Type]] is ~normal~, set _result_ to NormalCompletion(*undefined*).
1. If _result_.[[Type]] is ~return~, set _result_ to NormalCompletion(_result_.[[Value]]).
1. Perform AsyncGeneratorCompleteStep(_generator_, _result_, *true*).
1. Perform AsyncGeneratorDrainQueue(_generator_).
1. Return *undefined*.
1. Set _generator_.[[AsyncGeneratorContext]] to _genContext_.
1. Set _generator_.[[AsyncGeneratorState]] to ~suspendedStart~.
1. Set _generator_.[[AsyncGeneratorQueue]] to a new empty List.
1. Return ~unused~.
</emu-alg>
</emu-clause>
</emu-clause>
</emu-clause>

<emu-clause id="sec-async-function-objects">
<h1>AsyncFunction Objects</h1>

<emu-clause id="sec-async-functions-abstract-operations">
<h1>Async Functions Abstract Operations</h1>

<emu-clause id="sec-asyncblockstart" type="abstract operation">
<h1>
AsyncBlockStart (
_promiseCapability_: a PromiseCapability Record,
_asyncBody_: a Parse Node,
_asyncContext_: an execution context,
): ~unused~
</h1>
<dl class="header">
</dl>
<emu-alg>
1. Assert: _promiseCapability_ is a PromiseCapability Record.
1. Let _runningContext_ be the running execution context.
1. [fence-effects="user-code"] Set the code evaluation state of _asyncContext_ such that when evaluation is resumed for that execution context the following steps will be performed:
1. Let _result_ be the result of evaluating _asyncBody_.
1. Assert: If we return here, the async function either threw an exception or performed an implicit or explicit return; all awaiting is done.
1. Remove _asyncContext_ from the execution context stack and restore the execution context that is at the top of the execution context stack as the running execution context.
1. <ins>Let _env_ be _asyncContext_'s LexicalEnvironment.</ins>
1. <ins>Set _result_ to DisposeResources(_env_.[[DisposeCapability]], _result_).</ins>
1. If _result_.[[Type]] is ~normal~, then
1. Perform ! Call(_promiseCapability_.[[Resolve]], *undefined*, &laquo; *undefined* &raquo;).
1. Else if _result_.[[Type]] is ~return~, then
1. Perform ! Call(_promiseCapability_.[[Resolve]], *undefined*, &laquo; _result_.[[Value]] &raquo;).
1. Else,
1. Assert: _result_.[[Type]] is ~throw~.
1. Perform ! Call(_promiseCapability_.[[Reject]], *undefined*, &laquo; _result_.[[Value]] &raquo;).
1. [id="step-asyncblockstart-return-undefined"] Return ~unused~.
1. Push _asyncContext_ onto the execution context stack; _asyncContext_ is now the running execution context.
1. <emu-meta effects="user-code">Resume the suspended evaluation of _asyncContext_</emu-meta>. Let _result_ be the value returned by the resumed computation.
1. Assert: When we return here, _asyncContext_ has already been removed from the execution context stack and _runningContext_ is the currently running execution context.
1. Assert: _result_ is a normal completion with a value of ~unused~. The possible sources of this value are Await or, if the async function doesn't await anything, step <emu-xref href="#step-asyncblockstart-return-undefined"></emu-xref> above.
1. Return ~unused~.
</emu-alg>
</emu-clause>
</emu-clause>
</emu-clause>
</emu-clause>

<emu-annex id="sec-additional-ecmascript-features-for-web-browsers" namespace="annexB" normative>
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