[SR-9092] Could Not Resolve Type during swift Foundation debugging

[swift-ci]

Previous ID	SR-9092
Radar	rdar://problem/45595134
Original Reporter	levivic (JIRA User)
Type	Bug
Status	Resolved
Resolution	Cannot Reproduce

Attachment: Download

Environment

Linux

Additional Detail from JIRA

Votes	0
Component/s	Foundation, LLDB for Swift
Labels	Bug
Assignee	@adrian-prantl
Priority	Medium

md5: d7450fcc100c91a81b47f645eb0f3fe4

Issue Description:

Hi guys, i am trying to debug swift-corelibs-foundatin with lldb in Linux. However, it keeps giving me "<could not resolve type>" when I try to access a variable. Here is my testing example:

 import Foundation
 let c1 = NSDateComponents()
 let c2 = NSDateComponents()
 c2.calendar = c1.calendar
 let c1a = c1.calendar as Any
 print(c1a)
 let c2a = c2.calendar as Any
 print(c2a)

I have set breakpoint at `c2.calendar = c1.calendar`. When i step in, at some point it reaches `NSCalendar.swift` under Foundation as follows:

 (lldb) s
 Process 9448 stopped
 * thread #​1, name = 'simCalendarCopy', stop reason = step in
 frame #&#8203;0: 0x000003fffd6eff9e libFoundation.so`NSDateComponents.calendar.setter(newValue=<unavailable>, self=<unavailable>) at NSCalendar.swift:1428
 1425 return _calendar
 1426 }
 1427 set {
 -> 1428 if let val = newValue \{ 
1429 _calendar = val 
1430 } else {
 1431 _calendar = nil
 Target 0: (simCalendarCopy) stopped.

Then when i tried to use `fr v` to access variables, the debugger would show me `could not resolve type`. It looks like lldb won't print any variables when it gets into the Foundation code. Any ideas how to fix this?

[dcci]

@swift-ci create

[gottesmm]

Whatever the resolution of this, this seems pretty basic. Could we get an integration test for this?

[dcci]

Sure.

[swift-ci]

Comment by Jim Ingham (JIRA)

It isn't a matter of ADDING tests. We have lots of regression tests that create a swift module which imports Foundation, and then examines Foundation derived objects. It's just that all those tests are Darwin only at present. What Michael is really asking for - though he didn't know it 😉 - was for us to go sort out which of our Foundation tests run on Linux, and turn those tests on...

[dcci]

I'll try to take a look at this as soon as I can, but levivic (JIRA User) if you feel really adventurous, you might consider trying to fix this yourself, and I can probably give you some guidance (if you're up to it).

[swift-ci]

Comment by Leo Z (JIRA)

@dcci I don't mind looking into it. But at this moment i have no clue at all on how to fix this, please advise. thx

[dcci]

The first thing we might consider looking at is the type logs in ldlb.
when running lldb type at the console

log enable lldb types -f ~/lldb-log.txt

and then attach ~/lldb-log.txt to this SR, so we can have at least a clue of what's failing, and go from there.

[dcci]

(type that, then execute the commands that are failing, that is).

[swift-ci]

Comment by Leo Z (JIRA)

lldb-log.txt see the log file attached.

[dcci]

The log contains the culprit.

lldb             ((SwiftASTContext*)0x3ff6e5c6370)->GetTypeFromMangledTypename('$S10Foundation16NSDateComponentsCD')
lldb             ((SwiftASTContext*)0x3ff6e5c6370)->GetTypeFromMangledTypename('$S10Foundation16NSDateComponentsCD') -- not cached, searching
lldb             ((SwiftASTContext*)0x3ff6e5c6370)->GetTypeFromMangledTypename('$S10Foundation16NSDateComponentsCD') -- error: type for symbolname '' was not found

[dcci]

What I would start from is setting a breakpoint in

[swift-ci]

Comment by Leo Z (JIRA)

@dcci I have used gdb to debug swift compiler before. But these errors are from lldb. Suppose I have the problematic code example.swift as

 import Foundation
 let c1 = NSDateComponents()
 let c2 = NSDateComponents()
 c2.calendar = c1.calendar
 let c1a = c1.calendar as Any
 print(c1a)
 let c2a = c2.calendar as Any
 print(c2a)

And compile it to executable example. Then i try to debug lldb using gdb by gdb lldb, followed by r example and then r. However, it never hits the breakpoint SwiftASTContext::GetTypeFromMangledTypename.

Another question, as you mentioned debug `swiftc`, how can i debug `lldb` and `swiftc` at the same time?

[dcci]

You don't need to debug lldb and swiftc at the same time. Just attach to lldb.

[dcci]

If you're not able to hit that breakpoint, still, let me know and I'll take a look. Please note that you need a debug build both of the compiler and the debugger to be effective (i.e. you need to run ./build-script -d -lldb).

[swift-ci]

Comment by Leo Z (JIRA)

Following the step provided above, i still don't hit the breakpoint. Both the compiler and debugger are built in debug mode.