Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: d1ae3398fd0584ee719c6577a9b2840126563f1f
https://github.com/WebKit/WebKit/commit/d1ae3398fd0584ee719c6577a9b2840126563f1f
Author: Sosuke Suzuki <[email protected]>
Date: 2026-03-27 (Fri, 27 Mar 2026)
Changed paths:
M Source/JavaScriptCore/parser/ASTBuilder.h
M Source/JavaScriptCore/parser/Parser.cpp
M Source/JavaScriptCore/parser/SyntaxChecker.h
Log Message:
-----------
[JSC] Skip redundant RegExp syntax check when reparsing a function
https://bugs.webkit.org/show_bug.cgi?id=310785
Reviewed by Yusuke Suzuki.
ASTBuilder::createRegExp calls Yarr::checkSyntax on every regexp literal,
including during lazy compilation of a function body. But the enclosing
script's initial parse already validated these literals via SyntaxChecker
— as the existing comment in Parser::parse notes, we can never see a
syntax error when reparsing a function.
Pass isReparsingFunction() to createRegExp so it can skip the redundant
Yarr parse. This removes roughly 45% of the checkSyntax calls in
web-tooling-benchmark, where parser libraries like acorn and babylon
carry large Unicode identifier character classes.
This is inspired by a similar V8 change:
https://chromium-review.googlesource.com/c/v8/v8/+/7665887
* Source/JavaScriptCore/parser/ASTBuilder.h:
(JSC::ASTBuilder::createRegExp):
* Source/JavaScriptCore/parser/Parser.cpp:
(JSC::Parser<LexerType>::parsePrimaryExpression):
* Source/JavaScriptCore/parser/SyntaxChecker.h:
(JSC::SyntaxChecker::createRegExp):
Canonical link: https://commits.webkit.org/310139@main
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