[PATCH] Fix NULL unwinder dereference in StackFrameList

Subprojects LLDB
1

Hi all,

I’m attaching a proposed patch to fix an issue where lldb will seg fault if for some reason there is no unwinder when StackFrameList::GetFramesUpTo() is called.

The scenario where I’m hitting it is more fundamentally broken (the triple is unknown) - this small patch is just to stop lldb from crashing.

Thanks!

Sincerely,
Todd Fiala

null_unwinder.diff (1.86 KB)

2

Looks good.

% svn commit
Sending source/Target/StackFrameList.cpp
Transmitting file data .
Committed revision 195499.

3

For what it's worth, the unwinder is picked in Thread::GetStackFrameStatus() - we have a "last resort" unwinder for Apple triples that tries to walk the stack by following a frame chain for i386 or x86_64. Might be good to fall back to that even if the triple isn't -apple-.

(wouldn't have helped in this case where you didn't even have an architecture, let alone an OS, defined, but fwiw.)

4

Thanks, Jason! That’s good to know how it works in other cases.

My unknown target situation should be going away shortly here once we move over to something based on the lldb-debugserver feeding better info to lldb.