1998177 - Normative: Don't call well-known Symbol methods for RegExp on primitive values

Status: RESOLVED FIXED

(Core :: JavaScript: Standard Library, enhancement, P3)

Description

[Dan Minor [:dminor]]

This normative change was approved at the February 2025 TC39 plenary. See https://github.com/tc39/ecma262/pull/3009.

Comment 1

[Dan Minor [:dminor]]

Note that there's an initial implementation at https://phabricator.services.mozilla.com/D241314. Based upon comments there, we should probably remove the #ifdef and telemetry code and just make the changes.

We should coordinate landing this with V8 and JSC, it looks like they've already implemented the changes:

• V8 (https://issues.chromium.org/issues/451217461)
• JSC (https://github.com/WebKit/WebKit/pull/43240)

Comment 3

[Dan Minor [:dminor]]

Attachment: Bug 1998177 - Re-run mach gen-use-counter-metrics; r=jandem!

Comment 4

[Dan Minor [:dminor]]

Attachment: Bug 1998177 - Don't call well-known Symbol methods for regexp on primitives; r=jandem!

Depends on D273153

Comment 5

[Dan Minor [:dminor]]

Attachment: Bug 1998177 - Remove JS_regexp_symbol_protocol_on_primitive use counter; r=jandem!

Depends on D273154

Comment 6

[Dan Minor [:dminor]]

Attachment: Bug 1998177 - Remove now unused CanOptimizeStringProtoSymbolLookup and OptimizeStringPrototypeSymbolsFuse; r=jandem!

Depends on D273155

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/a6cac184cf43
https://hg.mozilla.org/integration/autoland/rev/f862da9656fa
Don't call well-known Symbol methods for regexp on primitives; r=jandem
https://github.com/mozilla-firefox/firefox/commit/308fa93df32b
https://hg.mozilla.org/integration/autoland/rev/34acf2c4e0ff
Remove JS_regexp_symbol_protocol_on_primitive use counter; r=jandem
https://github.com/mozilla-firefox/firefox/commit/663cd21c73e1
https://hg.mozilla.org/integration/autoland/rev/2d082de0848c
Remove now unused CanOptimizeStringProtoSymbolLookup and OptimizeStringPrototypeSymbolsFuse; r=jandem

Comment 8

[amarc]

https://hg.mozilla.org/mozilla-central/rev/f862da9656fa
https://hg.mozilla.org/mozilla-central/rev/34acf2c4e0ff
https://hg.mozilla.org/mozilla-central/rev/2d082de0848c