1246895 - Atomic operations do not throw RangeError for index -0

Status: RESOLVED INVALID

(Core :: JavaScript Engine, defect)

Description

[Lars T Hansen [:lth]]

Spec here:
https://tc39.github.io/ecmascript_sharedmem/shmem.html#Atomics.ValidateAtomicAccess

Step 6 says that if the index value is -0 then we should throw a RangeError, but we do not.  (This is in the interpreter, haven't checked the JIT yet.)

Test case here:
https://github.com/tc39/ecmascript_sharedmem/blob/master/test262/atomics-range.js

Comment 1

[Lars T Hansen [:lth]]

There is a bug in the shared memory spec here: ValidateAtomicAccess needs to more closely duplicate the logic of the ES6 spec with regard to how property names are interpreted.  For example, it is only when the property name is a string that -0 results in out-of-bounds like behavior in ES6, and when the property name is a number it is converted to a string by ToString(), which converts -0 to "0".

Ergo, using a string index "-0" should be an error, but using a number index that is -0 should not be an error.

Filed bug: https://github.com/tc39/ecmascript_sharedmem/issues/62.

Closing this bug until further notice.