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Normative: Remove [[VarNames]] from the global
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The upshot of this change is that global var bindings introduced by
sloppy direct eval becomes redeclarable by lexical bindings.
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@syg
syg committed Jan 8, 2025
1 parent fe206cd commit e43f65f
Showing 1 changed file with 4 additions and 51 deletions.
55 changes: 4 additions & 51 deletions spec.html
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Original file line number Diff line number Diff line change
Expand Up @@ -10869,17 +10869,6 @@ <h1>Global Environment Records</h1>
<emu-not-ref>Contains</emu-not-ref> bindings for all declarations in global code for the associated realm code except for |FunctionDeclaration|, |GeneratorDeclaration|, |AsyncFunctionDeclaration|, |AsyncGeneratorDeclaration|, and |VariableDeclaration| bindings.
</td>
</tr>
<tr>
<td>
[[VarNames]]
</td>
<td>
a List of Strings
</td>
<td>
The string names bound by |FunctionDeclaration|, |GeneratorDeclaration|, |AsyncFunctionDeclaration|, |AsyncGeneratorDeclaration|, and |VariableDeclaration| declarations in global code for the associated realm.
</td>
</tr>
</table>
</emu-table>
<emu-table id="table-additional-methods-of-global-environment-records" caption="Additional Methods of Global Environment Records" oldids="table-19">
Expand All @@ -10902,14 +10891,6 @@ <h1>Global Environment Records</h1>
Return the value of this Environment Record's `this` binding.
</td>
</tr>
<tr>
<td>
HasVarDeclaration (N)
</td>
<td>
Determines if the argument identifier has a binding in this Environment Record that was created using a |VariableDeclaration|, |FunctionDeclaration|, |GeneratorDeclaration|, |AsyncFunctionDeclaration|, or |AsyncGeneratorDeclaration|.
</td>
</tr>
<tr>
<td>
HasLexicalDeclaration (N)
Expand Down Expand Up @@ -11117,10 +11098,7 @@ <h1>
1. Let _globalObject_ be _ObjRec_.[[BindingObject]].
1. Let _existingProp_ be ? HasOwnProperty(_globalObject_, _N_).
1. If _existingProp_ is *true*, then
1. Let _status_ be ? <emu-meta effects="user-code">_ObjRec_.DeleteBinding</emu-meta>(_N_).
1. If _status_ is *true* and _envRec_.[[VarNames]] contains _N_, then
1. Remove _N_ from _envRec_.[[VarNames]].
1. Return _status_.
1. Return ? <emu-meta effects="user-code">_ObjRec_.DeleteBinding</emu-meta>(_N_).
1. Return *true*.
</emu-alg>
</emu-clause>
Expand Down Expand Up @@ -11175,26 +11153,6 @@ <h1>GetThisBinding ( ): a normal completion containing an Object</h1>
</emu-alg>
</emu-clause>

<emu-clause id="sec-hasvardeclaration" type="concrete method">
<h1>
HasVarDeclaration (
_N_: a String,
): a Boolean
</h1>
<dl class="header">
<dt>for</dt>
<dd>a Global Environment Record _envRec_</dd>

<dt>description</dt>
<dd>It determines if the argument identifier has a binding in this record that was created using a |VariableStatement| or a |FunctionDeclaration|.</dd>
</dl>
<emu-alg>
1. Let _varDeclaredNames_ be _envRec_.[[VarNames]].
1. If _varDeclaredNames_ contains _N_, return *true*.
1. Return *false*.
</emu-alg>
</emu-clause>

<emu-clause id="sec-haslexicaldeclaration" type="concrete method">
<h1>
HasLexicalDeclaration (
Expand Down Expand Up @@ -11298,7 +11256,7 @@ <h1>
<dd>a Global Environment Record _envRec_</dd>

<dt>description</dt>
<dd>It creates and initializes a mutable binding in the associated Object Environment Record and records the bound name in the associated [[VarNames]] List. If a binding already exists, it is reused and assumed to be initialized.</dd>
<dd>It creates and initializes a mutable binding in the associated Object Environment Record. If a binding already exists, it is reused and assumed to be initialized.</dd>
</dl>
<emu-alg>
1. Let _ObjRec_ be _envRec_.[[ObjectRecord]].
Expand All @@ -11308,8 +11266,6 @@ <h1>
1. If _hasProperty_ is *false* and _extensible_ is *true*, then
1. Perform ? <emu-meta effects="user-code">_ObjRec_.CreateMutableBinding</emu-meta>(_N_, _D_).
1. Perform ? <emu-meta effects="user-code">_ObjRec_.InitializeBinding</emu-meta>(_N_, *undefined*).
1. If _envRec_.[[VarNames]] does not contain _N_, then
1. Append _N_ to _envRec_.[[VarNames]].
1. Return ~unused~.
</emu-alg>
</emu-clause>
Expand All @@ -11327,7 +11283,7 @@ <h1>
<dd>a Global Environment Record _envRec_</dd>

<dt>description</dt>
<dd>It creates and initializes a mutable binding in the associated Object Environment Record and records the bound name in the associated [[VarNames]] List. If a binding already exists, it is replaced.</dd>
<dd>It creates and initializes a mutable binding in the associated Object Environment Record. If a binding already exists, it is replaced.</dd>
</dl>
<emu-alg>
1. Let _ObjRec_ be _envRec_.[[ObjectRecord]].
Expand All @@ -11339,8 +11295,6 @@ <h1>
1. Let _desc_ be the PropertyDescriptor { [[Value]]: _V_ }.
1. Perform ? DefinePropertyOrThrow(_globalObject_, _N_, _desc_).
1. [id="step-createglobalfunctionbinding-set"] Perform ? Set(_globalObject_, _N_, _V_, *false*).
1. If _envRec_.[[VarNames]] does not contain _N_, then
1. Append _N_ to _envRec_.[[VarNames]].
1. Return ~unused~.
</emu-alg>
<emu-note>
Expand Down Expand Up @@ -11569,7 +11523,6 @@ <h1>
1. Set _env_.[[ObjectRecord]] to _objRec_.
1. Set _env_.[[GlobalThisValue]] to _thisValue_.
1. Set _env_.[[DeclarativeRecord]] to _dclRec_.
1. Set _env_.[[VarNames]] to a new empty List.
1. Set _env_.[[OuterEnv]] to *null*.
1. Return _env_.
</emu-alg>
Expand Down Expand Up @@ -26156,9 +26109,9 @@ <h1>
1. Let _lexNames_ be the LexicallyDeclaredNames of _script_.
1. Let _varNames_ be the VarDeclaredNames of _script_.
1. For each element _name_ of _lexNames_, do
1. If _env_.HasVarDeclaration(_name_) is *true*, throw a *SyntaxError* exception.
1. If _env_.HasLexicalDeclaration(_name_) is *true*, throw a *SyntaxError* exception.
1. Let _hasRestrictedGlobal_ be ? _env_.HasRestrictedGlobalProperty(_name_).
1. NOTE: Global `var` and `function` bindings (except those that are introduced by non-strict direct eval) are non-configurable and are therefore restricted global properties.
1. If _hasRestrictedGlobal_ is *true*, throw a *SyntaxError* exception.
1. For each element _name_ of _varNames_, do
1. If _env_.HasLexicalDeclaration(_name_) is *true*, throw a *SyntaxError* exception.
Expand Down

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