Bug 298508 – [JSC] Add `async` prefix for async function frame on stack trace

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Sosuke Suzuki]

When we have code like this:

       async function one() { await two(); }
       async function two() { await three(); }
       async function three() { await 3; throw new Error("error from three");  }

    V8 generates stack traces like the following. Note that async functions that
    were executing before being suspended have an "async" prefix in the stack trace:

       Error: error from three
           at three (./WebKitBuild/Debug/test.js:3:41)
           at async two (./WebKitBuild/Debug/test.js:2:24)
           at async one (./WebKitBuild/Debug/test.js:1:24)

    Currently, JSC's async stack traces do not add this prefix.

[Sosuke Suzuki]

Pull request: https://github.com/WebKit/WebKit/pull/50418

[EWS]

Committed 299668@main (5dd8842ba4a0): <https://commits.webkit.org/299668@main>

Reviewed commits have been landed. Closing PR #50418 and removing active labels.

[Radar WebKit Bug Importer]

<rdar://problem/160042989>