https://github.com/JDevlieghere updated
https://github.com/llvm/llvm-project/pull/145935
>From 2b6a7e22481761b244e98dff00f905cf32a7d696 Mon Sep 17 00:00:00 2001
From: Jonas Devlieghere <jo...@devlieghere.com>
Date: Thu, 26 Jun 2025 10:31:09 -0700
Subject: [PATCH 1/2] [lldb] Document MCP support in LLDB
---
lldb/docs/index.rst | 1 +
lldb/docs/use/mcp.md | 68 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 69 insertions(+)
create mode 100644 lldb/docs/use/mcp.md
diff --git a/lldb/docs/index.rst b/lldb/docs/index.rst
index 1ffdb08a1ca2c..d49d0d8d5a733 100644
--- a/lldb/docs/index.rst
+++ b/lldb/docs/index.rst
@@ -135,6 +135,7 @@ interesting areas to contribute to lldb.
use/ondemand
use/aarch64-linux
use/symbolfilejson
+ use/mcp
use/troubleshooting
use/links
Man Page <man/lldb>
diff --git a/lldb/docs/use/mcp.md b/lldb/docs/use/mcp.md
new file mode 100644
index 0000000000000..a89740545e5f4
--- /dev/null
+++ b/lldb/docs/use/mcp.md
@@ -0,0 +1,68 @@
+# Model Context Protocol (MCP)
+
+LLDB supports for the [Model Context Protocol][1] (MCP). This structured,
+machine-friendly protocol allows AI models to access and interact with external
+tools, such as the debugger. Using MCP, an AI agent can execute LLDB commands
+to control the debugger: set breakpoints, inspect memory, step through code.
+This can range from helping you run a specific command you can't immediately
+remember to a fully agent-driven debugging experiences
+
+## MCP Server
+
+To start the MCP server in LLDB, use the `protocol-server start` command.
+Specify `MCP` as the protocol and provide a URI to listen on. For example, to
+start listening for local TCP connections on port `59999`, use the following
+command:
+
+```
+(lldb) protocol-server start MCP listen://localhost:59999
+MCP server started with connection listeners: connection://[::1]:59999,
connection://[127.0.0.1]:59999
+```
+
+The server will automatically stop when exiting LLDB, or it can be stopped
+explicitly with the `protocol-server stop` command.
+
+```
+(lldb) protocol-server stop MCP
+```
+
+## MCP Client
+
+MCP uses standard input/output (stdio) for communication between client and
+server. The exact configuration depends on the client, but most applications
+allow you to specify an MCP server as a binary and arguments. This means that
+you need to use something like `netcat` to connect to LLDB's MCP server and
+forward communication over stdio over the network connection.
+
+Configuration example for [Claude Code][2]:
+
+```
+{
+ "mcpServers": {
+ "tool": {
+ "command": "/usr/bin/nc",
+ "args": ["localhost", "59999"]
+ }
+ }
+}
+```
+
+Configuration example for [Visual Studio Code][3]:
+
+```
+{
+ "mcp": {
+ "servers": {
+ "lldb": {
+ "type": "stdio",
+ "command": "/usr/bin/nc",
+ "args": ["localhost", "59999"]
+ }
+ }
+ }
+}
+```
+
+[1]: https://modelcontextprotocol.io
+[2]: https://modelcontextprotocol.io/quickstart/user
+[3]: https://code.visualstudio.com/docs/copilot/chat/mcp-servers
>From 09a1ce5fdf1c96f89a8d412222e11d35b37c9da0 Mon Sep 17 00:00:00 2001
From: Jonas Devlieghere <jo...@devlieghere.com>
Date: Fri, 27 Jun 2025 09:49:15 -0700
Subject: [PATCH 2/2] Address David's feedback
---
lldb/docs/use/mcp.md | 39 ++++++++++++++++++++++++++++-----------
1 file changed, 28 insertions(+), 11 deletions(-)
diff --git a/lldb/docs/use/mcp.md b/lldb/docs/use/mcp.md
index a89740545e5f4..0a85f8ee9203e 100644
--- a/lldb/docs/use/mcp.md
+++ b/lldb/docs/use/mcp.md
@@ -1,11 +1,12 @@
# Model Context Protocol (MCP)
-LLDB supports for the [Model Context Protocol][1] (MCP). This structured,
-machine-friendly protocol allows AI models to access and interact with external
-tools, such as the debugger. Using MCP, an AI agent can execute LLDB commands
-to control the debugger: set breakpoints, inspect memory, step through code.
-This can range from helping you run a specific command you can't immediately
-remember to a fully agent-driven debugging experiences
+LLDB supports the [Model Context Protocol][https://modelcontextprotocol.io]
+(MCP). This structured, machine-friendly protocol allows AI models to access
+and interact with external tools, for example debuggers. Using MCP, an AI agent
+can execute LLDB commands to control the debugger: set breakpoints, inspect
+memory, step through code. This can range from helping you run a specific
+command you cannot immediately remember, to a fully agent-driven debugging
+experience.
## MCP Server
@@ -26,6 +27,9 @@ explicitly with the `protocol-server stop` command.
(lldb) protocol-server stop MCP
```
+The commands will fail if a server is already running or not running
+respectively.
+
## MCP Client
MCP uses standard input/output (stdio) for communication between client and
@@ -34,7 +38,15 @@ allow you to specify an MCP server as a binary and
arguments. This means that
you need to use something like `netcat` to connect to LLDB's MCP server and
forward communication over stdio over the network connection.
-Configuration example for [Claude Code][2]:
+```
+┌──────────┐ ┌──────────┐ ┌──────────┐
+│ │ │ │ │ │
+│ LLDB ├─────socket────┤ netcat ├─────stdio─────┤MCP Client│
+│ │ │ │ │ │
+└──────────┘ └──────────┘ └──────────┘
+```
+
+Configuration example for [Claude
Code][https://modelcontextprotocol.io/quickstart/user]:
```
{
@@ -47,7 +59,7 @@ Configuration example for [Claude Code][2]:
}
```
-Configuration example for [Visual Studio Code][3]:
+Configuration example for [Visual Studio
Code][https://code.visualstudio.com/docs/copilot/chat/mcp-servers]:
```
{
@@ -63,6 +75,11 @@ Configuration example for [Visual Studio Code][3]:
}
```
-[1]: https://modelcontextprotocol.io
-[2]: https://modelcontextprotocol.io/quickstart/user
-[3]: https://code.visualstudio.com/docs/copilot/chat/mcp-servers
+### Troubleshooting
+
+The MCP server uses the `Host` log channel. You can enable logging with the
+`log enable` command.
+
+```
+(lldb) log enable lldb host
+```
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