lldb has two RegisterLocation classes that do slightly different things. UnwindPlan::Row::RegisterLocation (new: AbstractRegisterLocation) has a description of how to find a register's value or location, not specific to a particular stopping point. It may say that at a given offset into a function, the caller's register has been spilled to stack memory at CFA minus an offset. Or it may say that the caller's register is at a DWARF exprssion. UnwindLLDB::RegisterLocation (new: ConcreteRegisterLocation) is a specific address where the register is currently stored, or the register it has been copied into, or its value at this point in the current function execution. When lldb stops in a function, it interprets the AbstractRegisterLocation's instructions using the register context and stack memory, to create the ConcreteRegisterLocation at this point in time for this stack frame. I'm not thrilled with AbstractRegisterLocation and ConcreteRegisterLocation, but it's better than the same name and it will be easier to update them if someone suggests a better pair.
19 KiB
19 KiB