[Lldb-commits] [PATCH] D124198: [LLDB][Unwind] Add stack scanning as fallback unwind plan if no symbol file is available.

[Jason Molenda via Phabricator via lldb-commits]

jasonmolenda added a comment.

I guess the other comment I would make is whether we should have a new ivar, instead of using the unused 0th bit of search_offset.

fwiw I wasn't real clear in my previous comment.  As you say in the title of this, you're trying to backtrace through a case where you have no symbol file, and I'm guessing the Windows ABI doesn't use a frame pointer register (rbp) that is is spilled to stack at the start of a stack frame by convention.  The ArchitecturalDefaultUnwindPlan's that we use on ABIs where you see saved-pc followed by saved-fp can do a stack walk following the chain of those two spilled registers pretty reliably, once they're off of the leaf frame.  This isn't the case on Windows right. You have nothing but a saved return address, and the stack pointer is not spilled unless there's some kind of variable length stack frame I'm guessing.


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  https://reviews.llvm.org/D124198/new/

https://reviews.llvm.org/D124198