NEW256941
Function.prototype.caller gives different values 
https://bugs.webkit.org/show_bug.cgi?id=256941
Summary Function.prototype.caller gives different values
GuY
Reported 2023-05-17 19:24:26 PDT
Created attachment 466392 [details] poc run with: ./WebKitBuild/Debug/bin/jsc --useConcurrentJIT=0 --jitPolicyScale=0.001 poc.js output: ``` true false false // for loop i = 0 false true false // for loop i = 1 false false true // main ``` the opt function was called 3 times. It was called from `a.valueOf` two times, and the 1st time JSC says caller is null, while the 2nd time JSC says caller is `opt`.
Attachments
poc (238 bytes, text/plain)
2023-05-17 19:24 PDT, GuY 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Radar WebKit Bug Importer
Comment 1 2023-05-24 19:25:16 PDT
<rdar://problem/109808960>
GuY
Comment 2 2024-08-20 02:06:43 PDT
This issue still exists, and here is a more detailed explanation of this issue. The `opt` function is called twice in the same way by the for loop, but the problem is `opt.caller` in these two times is different. The first time is `null`, and the second time is the `opt` function. This behavior could be confusing, even though `Function.prototype.caller` is not in the standard.
Note You need to log in before you can comment on or make changes to this bug.