[SR-9771] Playgrounds not Trapping during Bad Access

[swift-ci]

Previous ID	SR-9771
Radar	rdar://33820622
Original Reporter	SafelySwift (JIRA User)
Type	Bug

Attachment: Download

Environment


Additional Detail from JIRA

Votes	0
Component/s	Xcode Playground Support
Labels	Bug
Assignee	None
Priority	Medium

md5: 795ff7ff2b7dd30d73ddefbcd99f8fd5

Issue Description:

As per this Swift Forums topic, the following code should trap due to overlapping read/write access.

var stepSize = 1

func increment(_ number: inout Int) {
    number += stepSize
}

increment(&stepSize)

As specified on the docs,

> The read and write accesses refer to the same memory and they overlap, producing a conflict.

However, I put the code in a playground like such:


And nothing happens

[belkadan]

cc cwakamo (JIRA User), @atrick

[atrick]

This is indeed a known bug in Xcode playgrounds.