Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: c823243598c5b0ada8561918280e9a1d0649000d
https://github.com/WebKit/WebKit/commit/c823243598c5b0ada8561918280e9a1d0649000d
Author: Sosuke Suzuki <[email protected]>
Date: 2026-08-19 (Wed, 19 Aug 2026)
Changed paths:
M Source/JavaScriptCore/API/tests/testapi.mm
M Source/JavaScriptCore/runtime/CodeCache.cpp
Log Message:
-----------
[JSC] Bytecode cache should generate `CodeForConstruct` for class constructors
https://bugs.webkit.org/show_bug.cgi?id=193823
Reviewed by Yusuke Suzuki.
generateUnlinkedCodeBlockForFunctions only generates the CodeForCall variant of
every function.
For a class constructor that variant is just the "Cannot call a class
constructor" throw, emitted
before the body, so the cache holds neither the construct code nor the
functions nested in the
constructor body. Every `new C()` from a bytecode-cached program misses the
cache and reparses
the constructor from source; the implicit default constructor is reparsed from
the builtin source too.
Generate CodeForConstruct instead when the executable is a class constructor.
Calling a class
constructor throws, so nothing is lost. The async-function early return becomes
unreachable and is
removed. Ordinary functions still get CodeForCall only, since whether they are
constructed is not
known at cache time.
Constructing 182 three.js classes from a cached program: 253 -> 4 parses, 14.5
ms -> 10.3 ms.
babylon.js ES6 startup: 133 -> 9 parses, 30.7 ms -> 27.8 ms. Cache size grows
by the previously
missing constructor bodies (three.js +10.8%, a 50 MB application bundle +0.5%).
Test: Source/JavaScriptCore/API/tests/testapi.mm
* Source/JavaScriptCore/API/tests/testapi.mm:
(testBytecodeCachedClassConstructorsDontReparse):
(testObjectiveCAPI):
* Source/JavaScriptCore/runtime/CodeCache.cpp:
(JSC::generateUnlinkedCodeBlockForFunctions):
Canonical link: https://commits.webkit.org/319439@main
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