Feature problem: Cyclic __proto__ value

[Yi2255]

Problem

Code generators that use setPrototype may result in a cyclic assignment of __proto__ value.

Example

const o10 = {     __proto__: 64, }; const o11 = {     __proto__: o10, }; o10.__proto__ = o11; //TypeError: Cyclic __proto__ value

The problem is more likely to be reproduced with the following generators weighting.

cyclic assignment.txt

[saelo]

Right, this can happen. I'm not sure how big of an issue this is, but what we could do is create a dedicated SetPrototype IL operation and always use guards for it so that we emit a try-catch in JavaScript.

[Yi2255]

I understand your point. Thank you for sharing this idea!