1605835 - `({ 1n: 1 })` should not throw syntax error

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect, P1)

Description

[Toru Nagashima]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.88 Safari/537.36

Steps to reproduce:

Run a JavaScript code ({ 1n: 1 })

Actual results:

SyntaxError: expected property name, got bigint literal

Expected results:

It makes an object { 1: 1 }.

---

PropertyName contains BigInt literals. And I couldn't find any early errors for BigInt literals.

As the Evaluation section, if a property name is a numeric literal, the property name should be ToString of the numeric value.

Comment 1

[Seba S.]

Hi, Toru Nagashima!

Thanks for your contribution!

I don't have deep knowledge in JavaScript but I've checked according to the steps described with one of the devs here and we are receiving the same message on firefox and chrome. If this is not the intended or expected behavior, please respond to the thread here so we keep investigating.

Please let us know if this issue is reproduced in the latest Nightly edition. You can download it from here: https://nightly.mozilla.org/

Once you have all this information, please let us know so we can continue investigating.

Regards,

Comment 2

[Seba S.]

Attachment: chromejs.png

Comment 3

[Seba S.]

Attachment: ffjs.png

Comment 4

[André Bargull [:anba]]

Clearing NI because this is a valid bug, it just happens to be a bug present in both Firefox and Chrome.

Comment 5

[André Bargull [:anba]]

Attachment: Bug 1605835: Allow BigInts as property names. r=mgaudet!

BytecodeEmitter.cpp:

• ParseNode::getConstantValue directly calls BigIntLiteral::value() to match the
  existing use in that function. This is incompatible with deferred gc-things
  allocation, but doesn't matter in practice, because this all happens in dead code
  anyway.
• Drive-by change in emitObjLiteralValue(): Call MOZ_CRASH instead of returning
  false for unhandled parse nodes. And also assert the function is only called
  with valid parse nodes in the first place.

NameFunctions.cpp:

• BigInts aren't currently supported for guessed names, so just I've only updated
  the assertion condition.

Parser.cpp:

• Update spec reference from NumericLiteralBase to NonDecimalIntegerLiteral.
• The new bigIntAtom() function runs counter to the deferred gc-things work,
  but this inevitable as long as function names are computed in the parser.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/66693433b026
Allow BigInts as property names. r=mgaudet

Comment 7

[Cristian Brindusan [:cbrindusan]]

Backed out changeset 66693433b026 (bug 1605835) for jsreftest failures at property-name-guessed-name.js.
https://hg.mozilla.org/integration/autoland/rev/48e01247b97523ce4ba7b0f35381385030ccc16f

Push with failures:
https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=pending%2Crunning%2Csuccess%2Ctestfailed%2Cbusted%2Cexception&revision=66693433b026b40743573b60052561ee0a9a2616&selectedJob=284235525

Failure log:
https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=284235525&repo=autoland&lineNumber=2664

Comment 8

[André Bargull [:anba]]

It looks like the displayName testing function can't unwrap wrappers.

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/48303a40dd45
Allow BigInts as property names. r=mgaudet

Comment 10

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/48303a40dd45