891775 - Differential Testing: Different error message involving try... catch

Status: RESOLVED INVALID

(Core :: JavaScript Engine, defect)

Description

[Gary Kwong [:gkw] [:nth10sd] (NOT official MoCo now)]

function f() {
    [][""][""]
}
for (a in [0, 0, 0]) {
    try {
        f()
    } catch (e) {
        print('' + e)
    }
}

shows the following on a 64-bit debug js shell on m-c rev d87b950c7a6f:

TypeError: [][''] is undefined
TypeError: [][''] is undefined
TypeError: [][''] is undefined

but shows the following with --ion-eager:

TypeError: [][''] is undefined
TypeError: [][''] is undefined
TypeError: [][''][''] is undefined


This seems to be an old bug. Setting needinfo for jandem as this may cloud other correctness bugs.

Comment 1

[Jan de Mooij [:jandem]]

Gary this works for me with a more-determinstic shell. With and without --ion-eager:

TypeError: undefined has no properties
TypeError: undefined has no properties
TypeError: undefined has no properties

Unfortunately, different error messages with "normal" shells is expected due to the way the decompiler and IonMonkey work.

Comment 2

[Gary Kwong [:gkw] [:nth10sd] (NOT official MoCo now)]

Argh, I must have found something but used the wrong shell to reduce. I'm pretty sure there still are differential testing errors though, will file new bugs for those.