This abstracts the base Transport handler to have a MessageHandler
component and allows us to generalize both JSON-RPC 2.0 for MCP (or an
LSP) and DAP format.
This should allow us to create clearly defined clients and servers for
protocols, both for testing and for RPC between the lldb instances and
an lldb-mcp multiplexer.
This basic model is inspiried by the clangd/Transport.h file and the
mlir/lsp-server-support/Transport.h that are both used for LSP servers
within the llvm project.
Additionally, this helps with testing by subclassing `Transport` to
allow us to simplify sending/receiving messages without needing to use a
toJSON/fromJSON and a pair of pipes, see `TestTransport` in
DAP/TestBase.h.
* This adjusts the `Request`/`Response` types to have an `id` that is
either a string or a number.
* Merges 'Error' into 'Response' to have a single response type that
represents both errors and results.
* Adjusts the `Error.data` field to by any JSON value.
* Adds `operator==` support to the base protocol types and simplifies
the tests.
This is a continuation of #152188, which started splitting up the MCP
implementation into a generic implementation in Protocol/MCP that will
be shared between LLDB and lldb-mcp.
For now I kept all the networking code in the MCP server plugin. Once
the changes to JSONTransport land, we might be able to move more of it
into the Protocol library.
This moves all the generic MCP code into the new ProtocolMCP library so
it can be shared between the MCP implementation in LLDB (built on the
private API) and lldb-mcp (built on the public API).
This PR doesn't include the actual MCP server. The reason is that the
transport mechanism will be different between the LLDB implementation
(using sockets) and the lldb-mcp implementation (using stdio). The goal
s to abstract away that difference by making the server use
JSONTransport (again) but I'm saving that for a separate PR.
This PR moves the MCP protocol code into its own library
(`lldbProtocolMCP`) so the code can be shared between the
`ProtocolServerMCP` plugin in LLDB as well as `lldb-mcp`. The goal is to
do the same thing for DAP (which, for now, would be used exclusively
from `lldb-dap`).
To make it clear that it's neither part of the `lldb` nor the
`lldb_private` namespace, I created a new `lldb_protocol` namespace.
Depending on how much code would be reused by lldb-dap, we may move more
code into the protocol library.
