Bug 231237

Summary:	Pass experimental feature flags (from WTF) to JSC
Product:	WebKit	Reporter:	Sam Sneddon [:gsnedders] <gsnedders>
Component:	JavaScriptCore	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	fpizlo, lwarlow, sam, simon.fraser, webkit-bug-importer, ysuzuki
Priority:	P2	Keywords:	InRadar
Version:	WebKit Local Build
Hardware:	Unspecified
OS:	Unspecified

Description Sam Sneddon [:gsnedders] 2021-10-05 09:58:49 PDT

Eric Meyer asked on Slack:

> The TP133 notes say one can enable Temporal using the flag --useTemporal=1.  How exactly does one flip that flag so as to test Temporal?

The answer as many of us here know:

> When launching Safari from CLI, passing __XPC_JSC_useTemporal=1 environment variable.

It's somewhat surprising that we don't expose this through the experimental features menu (and it means that you can't toggle such features on iOS), and we should fix things so that we can pass the flags through (per Yusuke, "WebCore’s experimental feature mechanism is not piped to JSC").

Comment 1 Radar WebKit Bug Importer 2021-10-05 09:59:00 PDT

<rdar://problem/83891333>