Bug 250511 – JSValueGetType() is incorrect for BigInt values

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Kasper Isager Dalsgarð]

JSValueGetType() currently has no path for values of type BigInt and therefore falls through to the object case, returning kJSTypeObject:

https://github.com/WebKit/WebKit/blob/8196614cb0623111b43d1041469eb3247e5623bb/Source/JavaScriptCore/API/JSValueRef.cpp#L51-L79

I imagine a kJSTypeBigInt value should be introduced and a path for jsValue.isBigInt() added.

[Radar WebKit Bug Importer]

<rdar://problem/104194532>

[Mark Lam]

Hmmm, JSBigInt directly extends JSCell, and therefore, not is not a JSObject.  We should fix this.

[Kasper Isager Dalsgarð]

On a related note, JSValueIsBigInt() would be great as well.

[Kasper Isager Dalsgarð]

The same goes for variants of JSValueMakeBigInt*() and JSValueToBigInt*(); those are sorely missed as well.

[Mark Lam]

Adding JSValueMakeBigInt*() and JSValueToBigInt*() is going to take a lot more time to make sure the API is correct.

[Kasper Isager Dalsgarð]

For converting BigInts to C primitives, there already seem to be private APIs available:

https://github.com/WebKit/WebKit/blob/4abc58df4642909ba616e53f76f7e69b18934b18/Source/JavaScriptCore/runtime/JSCJSValue.h#L312-L313

[Mark Lam]

(In reply to Kasper Isager Dalsgarð from comment #6)
> For converting BigInts to C primitives, there already seem to be private
> APIs available:
> 
> https://github.com/WebKit/WebKit/blob/
> 4abc58df4642909ba616e53f76f7e69b18934b18/Source/JavaScriptCore/runtime/
> JSCJSValue.h#L312-L313

The complication isn't with the primitives.  It's with getting the API correct e.g. for interactions with other API, for correctness, for security, for performance, etc.  Designing that and testing it will take time.

[Kasper Isager Dalsgarð]

Noted! It also wasn't directly relevant to the initial bug report, so I'll open separate tickets.

[Kasper Isager Dalsgarð]

Is there any news on this?

[Kasper Isager Dalsgarð]

Do let me know if there's anything I can do to help get this fixed. I'd be more than happy to provide a patch as well. Thanks!

[Yijia Huang]

Pull request: https://github.com/WebKit/WebKit/pull/19251

[Kasper Isager Dalsgarð]

That's fantastic, thanks so much! That also deals with most of https://bugs.webkit.org/show_bug.cgi?id=250719, with the exception of conversion back to numbers.

[Yijia Huang]

*** Bug 250719 has been marked as a duplicate of this bug. ***

[EWS]

Committed 278275@main (c97a08d9e56f): <https://commits.webkit.org/278275@main>

Reviewed commits have been landed. Closing PR #19251 and removing active labels.

[Yijia Huang]

Reopened Bugzilla.
Failed Xcode build, tracking revert in https://bugs.webkit.org/show_bug.cgi?id=273705.

[Yijia Huang]

Pull request: https://github.com/WebKit/WebKit/pull/28121

[EWS]

Committed 278588@main (e8e344010871): <https://commits.webkit.org/278588@main>

Reviewed commits have been landed. Closing PR #28121 and removing active labels.