<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<!DOCTYPE bugzilla SYSTEM "https://bugs.webkit.org/page.cgi?id=bugzilla.dtd">

<bugzilla version="5.0.4.1"
          urlbase="https://bugs.webkit.org/"
          
          maintainer="admin@webkit.org"
>

    <bug>
          <bug_id>206174</bug_id>
          
          <creation_ts>2020-01-13 06:28:18 -0800</creation_ts>
          <short_desc>Calculate new PropertyList features during parsing</short_desc>
          <delta_ts>2020-01-13 06:30:21 -0800</delta_ts>
          <reporter_accessible>1</reporter_accessible>
          <cclist_accessible>1</cclist_accessible>
          <classification_id>1</classification_id>
          <classification>Unclassified</classification>
          <product>WebKit</product>
          <component>JavaScriptCore</component>
          <version>WebKit Nightly Build</version>
          <rep_platform>Unspecified</rep_platform>
          <op_sys>Unspecified</op_sys>
          <bug_status>NEW</bug_status>
          <resolution></resolution>
          
          
          <bug_file_loc></bug_file_loc>
          <status_whiteboard></status_whiteboard>
          <keywords>GoodFirstBug</keywords>
          <priority>P2</priority>
          <bug_severity>Minor</bug_severity>
          <target_milestone>---</target_milestone>
          <dependson>174212</dependson>
          
          <everconfirmed>1</everconfirmed>
          <reporter name="Caitlin Potter (:caitp)">caitp</reporter>
          <assigned_to name="Nobody">webkit-unassigned</assigned_to>
          
          

      

      

      

          <comment_sort_order>oldest_to_newest</comment_sort_order>  
          <long_desc isprivate="0" >
    <commentid>1605821</commentid>
    <comment_count>0</comment_count>
    <who name="Caitlin Potter (:caitp)">caitp</who>
    <bug_when>2020-01-13 06:28:18 -0800</bug_when>
    <thetext>Minor optimization requested in https://bugs.webkit.org/attachment.cgi?id=387361&amp;action=review#line1046

It might be worthwhile to pre-calculate the result of &apos;shouldCreateLexicalSCopeForClass&apos; and &apos;hasInstanceFields&apos; 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.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>1605822</commentid>
    <comment_count>1</comment_count>
    <who name="Caitlin Potter (:caitp)">caitp</who>
    <bug_when>2020-01-13 06:30:21 -0800</bug_when>
    <thetext>If this gets taken on, I think it qualifies as a good first bug.</thetext>
  </long_desc>
      
      

    </bug>

</bugzilla>