Bug 206174

Summary: Calculate new PropertyList features during parsing
Product: WebKit Reporter: Caitlin Potter (:caitp) <caitp>
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Minor Keywords: GoodFirstBug
Priority: P2    
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on: 174212    
Bug Blocks:    

Description Caitlin Potter (:caitp) 2020-01-13 06:28:18 PST 
Minor optimization requested in https://bugs.webkit.org/attachment.cgi?id=387361&action=review#line1046

It might be worthwhile to pre-calculate the result of 'shouldCreateLexicalSCopeForClass' and 'hasInstanceFields' during parsing, or otherwise cache the value after the first calculation.

Reasons for not doing this: it makes things like AST rewriting a bit more awkward and error prone (but, AST rewriting is not as common in JSC as in v8), and the hit from walking property list to determine these features might not be significant as they are not believed to be invoked frequently.

It warrants some investigation.
Comment 1 Caitlin Potter (:caitp) 2020-01-13 06:30:21 PST 
If this gets taken on, I think it qualifies as a good first bug.