[SR-15128] LLDB Crash

[swift-ci]

Previous ID	SR-15128
Radar	rdar://problem/82543261
Original Reporter	dalk (JIRA User)
Type	Bug

Environment

xcode 12.5.0

Additional Detail from JIRA

| | | |------------------|-----------------| |Votes | 0 | |Component/s | Compiler, LLDB for Swift | |Labels | Bug | |Assignee | @adrian-prantl | |Priority | Medium | md5: 1411048b52a88fb0a49aecc05e14bcc1

Issue Description:

100 % reproducible crash when compiling this piece of code. Please note that if MyClass is a struct, it doesnt crash. Same if we change "if let entry = entry" to "if let anything = entry"

class MyClass {

**let** value: Int

**init**(value: Int)

{ self.value = value }

}

func test() {

**let** cachedImages: ThreadSafeMap\<String, MyClass\> = ThreadSafeMap\<String, MyClass\>(label: "")

**let** entry = cachedImages.get(key: "toto")

**guard** **let** entry = entry **else**

{ return }

}

public class ThreadSafeMap\<T: Hashable, U: AnyObject> {

**private** **var** map: \[T: U\] = \[:\]

**private** **let** cacheAccessQueue: DispatchQueue

**public** **init**(label: String)

{ self.cacheAccessQueue = DispatchQueue(label: label, qos: .userInitiated, attributes: .concurrent) }

**public** **func** get(key: T) -\> U? {

    cacheAccessQueue.sync

{ return map[key] }

}

}

[typesanitizer]

@swift-ci create

[typesanitizer]

Could you clarify what exactly is crashing? You said "reproducible crash when compiling this piece of code" – but the title says "LLDB crash". Can you attach a stack trace?

[adrian-prantl]

Yeah, this compiles fine. Can you attach a crash log and/or more instructions?