[lldb-dev] Refactoring in LLDB Windows Plugin

[Greg Clayton via lldb-dev]

> On Nov 29, 2016, at 10:16 PM, Zachary Turner <zturner at google.com> wrote:
> 
> What would it take to make it so that local and remote process plugins use the same exact interface?  I mean in theory they're doing the same thing, just on a different machine.  If they shared an identical interface then you could hook the lldb-server up to it and it would work either locally or remotely.
> 
> What was the original motivation for having the api design of remote and local process plugins diverge?

The plan was always do remote so we are always using one thing. We started off thinking we wanted to have a native plug-in and a remote GDB server, but when we found we didn't have serious performance issues we went the lldb-server/debugserver route for everything on our end. lldb-server uses NativeProcess and NativeThread as base classes that must be subclassed and we would make a ProcessNative plug-in that used the native compiled version of these (like lldb-server does), but then we have two code paths to test: native and remote. So we either have to run twice the number of tests, one local and one remote, so we can make sure native and remote work correctly, or we just go one route. What would tend to happen is we would 99.9% of people would do local debugging only and all bugs submitted would mostly be bugs with the native implementation and remote would suffer and become neglected. GDB had two different code paths for these so remote really did suffer and we evolved to use remote only on all our systems. Another nice reason for this is you can save the GDB remote packet log traffic when you do encounter a bug and see exactly what happened when a bug happened. 

So due to history, we started thinking we would need both native and remote plug-ins, but we migrated over time to just one solution for simpler testing, ensuring remote debugging is rock solid since it is always used for local debugging, and for the convenience of being able to completely lop all traffic to/from the process with the GDB remote logs.

Greg