1592356 - Remove LazyScript::hasNonSyntacticScope

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task, P2)

Description

[Ted Campbell [:tcampbell]]

Currently the definition of hasNonSyntacticScope differs between LazyScript and JSScript. We have already moved the HasNonSyntacticScope flag to BaseScript so this is a bit of a foot-gun (see: Bug 1591921).

Instead, the frontend should properly compute the non-syntactic flag while creating the LazyScript and should use the HasNonSyntacticScope flag to hold result.

Once this is done, the js::CanReuseScriptForClone function should be updated to use baseScript().

Comment 1

[Ted Campbell [:tcampbell]]

Attachment: Bug 1592356 - Remove LazyScript::hasNonSyntacticScope. r?jandem

Update js::CanReuseScriptForClone to use baseScript() to determine if
non-syntactic. The HasNonSyntacticScope is not computed for lazy scripts so
fall back to checking the scope. Technically this is a fraction slower when
cloning a script with a syntactic global into a function with a non-syntactic
global, but in that case we are just about to clone the entire script
anyways. In practice this rarely comes up.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/709cb0205720
Remove LazyScript::hasNonSyntacticScope. r=jandem

Comment 3

[Cristina Coroiu [:ccoroiu]]

https://hg.mozilla.org/mozilla-central/rev/709cb0205720