[all-commits] [llvm/llvm-project] 701030: In InitializeZerothFrame check for a CFA/AFA or er...

[Jason Molenda via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 701030c3ecba0621ce5d325667fb75b73cf1532b
      https://github.com/llvm/llvm-project/commit/701030c3ecba0621ce5d325667fb75b73cf1532b
  Author: Jason Molenda <jason at molenda.com>
  Date:   2023-02-06 (Mon, 06 Feb 2023)

  Changed paths:
    M lldb/source/Target/RegisterContextUnwind.cpp

  Log Message:
  -----------
  In InitializeZerothFrame check for a CFA/AFA or error out

There is a failure where we somehow get an invalid register
number being used to calculate the canonical frame address,
and this ends up with lldb crashing with a null deref because it
assumes that it is always able to find information about that
register.

This patch adds a check for a failure to get a register, and
declares the frame invalid in that case, with some additional
logging or an assert for debug builds.

Differential Revision: https://reviews.llvm.org/D143232
rdar://104428038