[lldb-dev] Increasing support for other gdbservers

[Greg Clayton]

> On Mar 31, 2015, at 3:35 AM, Aidan Dodds <aidan at codeplay.com> wrote:
> 
> On 30/03/2015 18:38, Greg Clayton wrote:
> >
> > I know about the register numbering stuff and I would love to see support for the "$qXfer:features:" added to LLDB. The one thing this data doesn't contain is the register numbers for the ABI (DWARF register numbers (for debug info), compiler register numbers (for like .eh_frame)), but that info could be inferred from an ABI plugin that we could infer from the "osabi" of "GNU/Linux" in the target.xml:
> 
> >
> > So please do submit patches that implement this and we will be happy to approve them.
> 
> I am currently prototyping $qXfer:features support in LLDB with an aim to upstream it. It will require an XML parser, so I wanted to have a discussion about adding one to LLDB.

Most unix variants have libxml2 that is available. I am not sure on windows though. I have CC'ed Zachary to get some input on windows XML (in case LLVM doesn't already have some support for this).

> I have been using TinyXML2 in my prototype, which is open sourced under the ZLib license. Is there any policy in LLDB for handling external library dependencies?
> Would there be objections to TinyXML2 making its way into the LLDB code base as an external? Writing a new XML parser from scratch in LLDB isn't ideal.

It would be great to stick with stuff that everyone has installed and hopefully that is libxml2. Windows is the biggest question. I am also not sure if llvm or clang has any XML support, but we should first look to see if llvm has XML support and if not, then look for alternatives. We definitely do not want to write our own.
> 
> I would still like to have a discussion about adding a plugin architecture to gdb-remote making it easier to handle packets outwith the LLDB based servers. The code in gdb-remote that sends and handles packets is scattered over one or two huge classes, it would be beneficial to start looking at breaking this up and modularizing it. At least for the packets which are not supported by lldb's own RSP producers.

I say just build all and any support it into GDBRemoteCommunicationClient and GDBRemoteCommunicationServer. I don't see the need to break it up.

Greg Clayton