mirror of
https://github.com/LadybirdBrowser/ladybird
synced 2026-04-30 11:37:16 +02:00
afae23e270
When a function has parameter expressions (default values), body var declarations that shadow a name referenced in a default parameter expression must not be optimized to local variables. The default expression needs to resolve the name from the outer scope via the environment chain, not read the uninitialized local. We now mark identifiers referenced during formal parameter parsing with an IsReferencedInFormalParameters flag, and skip local variable optimization for body vars that carry both this flag and IsVar (but not IsForbiddenLexical, which indicates parameter names themselves).
31 lines
1.4 KiB
Plaintext
31 lines
1.4 KiB
Plaintext
JS bytecode executable ""
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[ 0] 0: GetLexicalEnvironment dst:reg4
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[ 8] SetGlobal identifier:shadow, src:String("outer")
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[ 18] GetGlobal dst:reg6, identifier:shadow_in_default
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[ 28] Call dst:reg5, callee:reg6, this_value:Undefined, shadow_in_default
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[ 48] GetGlobal dst:reg7, identifier:no_conflict
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[ 58] Call dst:reg6, callee:reg7, this_value:Undefined, no_conflict
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[ 78] End value:reg6
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JS bytecode executable "shadow_in_default"
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[ 0] 0: GetLexicalEnvironment dst:reg4
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[ 8] JumpUndefined condition:arg0, true_target:@18, false_target:@40
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[ 18] 1: GetInitializedBinding dst:reg5, identifier:shadow
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[ 30] Mov dst:arg0, src:reg5
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[ 40] 2: CreateVariableEnvironment capacity:1
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[ 48] GetLexicalEnvironment dst:reg5
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[ 50] Mov dst:reg6, src:Undefined
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[ 60] CreateVariable identifier:shadow, is_immutable:false, is_global:false, is_strict:false
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[ 70] InitializeVariableBinding identifier:shadow, src:reg6
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[ 88] SetLexicalBinding identifier:shadow, src:String("inner")
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[ a0] Return value:arg0
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JS bytecode executable "no_conflict"
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[ 0] 0: GetLexicalEnvironment dst:reg4
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[ 8] JumpUndefined condition:arg0, true_target:@18, false_target:@28
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[ 18] 1: Mov dst:arg0, src:Int32(1)
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[ 28] 2: Mov dst:reg5, src:Undefined
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[ 38] Mov dst:y~0, src:reg5
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[ 48] Mov dst:y~0, src:Int32(2)
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[ 58] Return value:y~0
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