Xcode debugger (lldb) get object description from

问题:

Little-known fact: It is now possible, in Xcode, while paused in the debugger, to introspect the notification center to learn what objects are registered to receive what notifications:

(lldb) po NotificationCenter.default

<NSNotificationCenter:0x6040000d40b0>
Name, Object, Observer, Options
com.apple.accessibility.reduce.motion.status, 0x10b126190, 0x7fc795700140, 1001
com.apple.accessibility.asst.scanner.status, 0x10b126190, 0x7fc795700140, 1001
// ... etc. ...

Very nice, but how do I get from the memory address 0x7fc795700140 to learning what object that is?

EDIT I'm leaving this question here, but I think the correct answer is the kind of thing shown at LLDB (Swift): Casting Raw Address into Usable Type

回答1:

po works for addresses (In Objective-C/Mac context, at least)

e.g.:

(lldb) po [NSNotificationCenter defaultCenter]

NSWindowDidResizeNotification, 0x7fff9a0e98e0, 0x6100001246a0, 1400

(lldb) po 0x6100001246a0

ExpandOneView: 0x6100001246a0

回答2:

The Swift equivalent of Phillip's answer is:

(lldb) expr -l objc -O -- 0x7fc795700140
<UIApplication: 0x7fc795700140>