[Lldb-commits] [lldb] [lldb] Add Model Context Protocol (MCP) support to LLDB (PR #143628)
Jonas Devlieghere via lldb-commits
lldb-commits at lists.llvm.org
Thu Jun 19 19:26:12 PDT 2025
https://github.com/JDevlieghere updated https://github.com/llvm/llvm-project/pull/143628
>From d0421ef2751a827a09d1ea5e9eb4457afea7c59d Mon Sep 17 00:00:00 2001
From: Jonas Devlieghere <jonas at devlieghere.com>
Date: Thu, 12 Jun 2025 16:33:55 -0700
Subject: [PATCH] [lldb] Add MCP support to LLDB
https://discourse.llvm.org/t/rfc-adding-mcp-support-to-lldb/86798
---
lldb/cmake/modules/LLDBConfig.cmake | 1 +
lldb/include/lldb/Core/Debugger.h | 6 +
lldb/include/lldb/Core/PluginManager.h | 11 +
lldb/include/lldb/Core/ProtocolServer.h | 39 +++
.../Interpreter/CommandOptionArgumentTable.h | 1 +
lldb/include/lldb/lldb-enumerations.h | 1 +
lldb/include/lldb/lldb-forward.h | 3 +-
lldb/include/lldb/lldb-private-interfaces.h | 2 +
lldb/source/Commands/CMakeLists.txt | 1 +
.../Commands/CommandObjectProtocolServer.cpp | 176 ++++++++++
.../Commands/CommandObjectProtocolServer.h | 25 ++
lldb/source/Core/CMakeLists.txt | 1 +
lldb/source/Core/Debugger.cpp | 24 ++
lldb/source/Core/PluginManager.cpp | 32 ++
lldb/source/Core/ProtocolServer.cpp | 21 ++
.../source/Interpreter/CommandInterpreter.cpp | 2 +
lldb/source/Plugins/CMakeLists.txt | 4 +
lldb/source/Plugins/Protocol/CMakeLists.txt | 1 +
.../Plugins/Protocol/MCP/CMakeLists.txt | 13 +
lldb/source/Plugins/Protocol/MCP/MCPError.cpp | 34 ++
lldb/source/Plugins/Protocol/MCP/MCPError.h | 33 ++
lldb/source/Plugins/Protocol/MCP/Protocol.cpp | 214 ++++++++++++
lldb/source/Plugins/Protocol/MCP/Protocol.h | 128 +++++++
.../Protocol/MCP/ProtocolServerMCP.cpp | 327 ++++++++++++++++++
.../Plugins/Protocol/MCP/ProtocolServerMCP.h | 100 ++++++
lldb/source/Plugins/Protocol/MCP/Tool.cpp | 81 +++++
lldb/source/Plugins/Protocol/MCP/Tool.h | 56 +++
lldb/unittests/CMakeLists.txt | 4 +
lldb/unittests/DAP/ProtocolTypesTest.cpp | 38 +-
lldb/unittests/Protocol/CMakeLists.txt | 12 +
.../Protocol/ProtocolMCPServerTest.cpp | 291 ++++++++++++++++
lldb/unittests/Protocol/ProtocolMCPTest.cpp | 135 ++++++++
lldb/unittests/TestingSupport/TestUtilities.h | 9 +
33 files changed, 1803 insertions(+), 23 deletions(-)
create mode 100644 lldb/include/lldb/Core/ProtocolServer.h
create mode 100644 lldb/source/Commands/CommandObjectProtocolServer.cpp
create mode 100644 lldb/source/Commands/CommandObjectProtocolServer.h
create mode 100644 lldb/source/Core/ProtocolServer.cpp
create mode 100644 lldb/source/Plugins/Protocol/CMakeLists.txt
create mode 100644 lldb/source/Plugins/Protocol/MCP/CMakeLists.txt
create mode 100644 lldb/source/Plugins/Protocol/MCP/MCPError.cpp
create mode 100644 lldb/source/Plugins/Protocol/MCP/MCPError.h
create mode 100644 lldb/source/Plugins/Protocol/MCP/Protocol.cpp
create mode 100644 lldb/source/Plugins/Protocol/MCP/Protocol.h
create mode 100644 lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.cpp
create mode 100644 lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.h
create mode 100644 lldb/source/Plugins/Protocol/MCP/Tool.cpp
create mode 100644 lldb/source/Plugins/Protocol/MCP/Tool.h
create mode 100644 lldb/unittests/Protocol/CMakeLists.txt
create mode 100644 lldb/unittests/Protocol/ProtocolMCPServerTest.cpp
create mode 100644 lldb/unittests/Protocol/ProtocolMCPTest.cpp
diff --git a/lldb/cmake/modules/LLDBConfig.cmake b/lldb/cmake/modules/LLDBConfig.cmake
index 37b823feb584b..8c30b6e09d2c7 100644
--- a/lldb/cmake/modules/LLDBConfig.cmake
+++ b/lldb/cmake/modules/LLDBConfig.cmake
@@ -67,6 +67,7 @@ add_optional_dependency(LLDB_ENABLE_FBSDVMCORE "Enable libfbsdvmcore support in
option(LLDB_USE_ENTITLEMENTS "When codesigning, use entitlements if available" ON)
option(LLDB_BUILD_FRAMEWORK "Build LLDB.framework (Darwin only)" OFF)
+option(LLDB_ENABLE_PROTOCOL_SERVERS "Enable protocol servers (e.g. MCP) in LLDB" ON)
option(LLDB_NO_INSTALL_DEFAULT_RPATH "Disable default RPATH settings in binaries" OFF)
option(LLDB_USE_SYSTEM_DEBUGSERVER "Use the system's debugserver for testing (Darwin only)." OFF)
option(LLDB_SKIP_STRIP "Whether to skip stripping of binaries when installing lldb." OFF)
diff --git a/lldb/include/lldb/Core/Debugger.h b/lldb/include/lldb/Core/Debugger.h
index 2087ef2a11562..9f82466a83417 100644
--- a/lldb/include/lldb/Core/Debugger.h
+++ b/lldb/include/lldb/Core/Debugger.h
@@ -602,6 +602,10 @@ class Debugger : public std::enable_shared_from_this<Debugger>,
void FlushProcessOutput(Process &process, bool flush_stdout,
bool flush_stderr);
+ void AddProtocolServer(lldb::ProtocolServerSP protocol_server_sp);
+ void RemoveProtocolServer(lldb::ProtocolServerSP protocol_server_sp);
+ lldb::ProtocolServerSP GetProtocolServer(llvm::StringRef protocol) const;
+
SourceManager::SourceFileCache &GetSourceFileCache() {
return m_source_file_cache;
}
@@ -772,6 +776,8 @@ class Debugger : public std::enable_shared_from_this<Debugger>,
mutable std::mutex m_progress_reports_mutex;
/// @}
+ llvm::SmallVector<lldb::ProtocolServerSP> m_protocol_servers;
+
std::mutex m_destroy_callback_mutex;
lldb::callback_token_t m_destroy_callback_next_token = 0;
struct DestroyCallbackInfo {
diff --git a/lldb/include/lldb/Core/PluginManager.h b/lldb/include/lldb/Core/PluginManager.h
index 1d7c976f3c382..d1af25988e50f 100644
--- a/lldb/include/lldb/Core/PluginManager.h
+++ b/lldb/include/lldb/Core/PluginManager.h
@@ -321,6 +321,17 @@ class PluginManager {
static void AutoCompleteProcessName(llvm::StringRef partial_name,
CompletionRequest &request);
+ // Protocol
+ static bool RegisterPlugin(llvm::StringRef name, llvm::StringRef description,
+ ProtocolServerCreateInstance create_callback);
+
+ static bool UnregisterPlugin(ProtocolServerCreateInstance create_callback);
+
+ static llvm::StringRef GetProtocolServerPluginNameAtIndex(uint32_t idx);
+
+ static ProtocolServerCreateInstance
+ GetProtocolCreateCallbackForPluginName(llvm::StringRef name);
+
// Register Type Provider
static bool RegisterPlugin(llvm::StringRef name, llvm::StringRef description,
RegisterTypeBuilderCreateInstance create_callback);
diff --git a/lldb/include/lldb/Core/ProtocolServer.h b/lldb/include/lldb/Core/ProtocolServer.h
new file mode 100644
index 0000000000000..fafe460904323
--- /dev/null
+++ b/lldb/include/lldb/Core/ProtocolServer.h
@@ -0,0 +1,39 @@
+//===-- ProtocolServer.h --------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_CORE_PROTOCOLSERVER_H
+#define LLDB_CORE_PROTOCOLSERVER_H
+
+#include "lldb/Core/PluginInterface.h"
+#include "lldb/Host/Socket.h"
+#include "lldb/lldb-private-interfaces.h"
+
+namespace lldb_private {
+
+class ProtocolServer : public PluginInterface {
+public:
+ ProtocolServer() = default;
+ virtual ~ProtocolServer() = default;
+
+ static lldb::ProtocolServerSP Create(llvm::StringRef name,
+ Debugger &debugger);
+
+ struct Connection {
+ Socket::SocketProtocol protocol;
+ std::string name;
+ };
+
+ virtual llvm::Error Start(Connection connection) = 0;
+ virtual llvm::Error Stop() = 0;
+
+ virtual Socket *GetSocket() const = 0;
+};
+
+} // namespace lldb_private
+
+#endif
diff --git a/lldb/include/lldb/Interpreter/CommandOptionArgumentTable.h b/lldb/include/lldb/Interpreter/CommandOptionArgumentTable.h
index 8535dfcf46da5..4face717531b1 100644
--- a/lldb/include/lldb/Interpreter/CommandOptionArgumentTable.h
+++ b/lldb/include/lldb/Interpreter/CommandOptionArgumentTable.h
@@ -315,6 +315,7 @@ static constexpr CommandObject::ArgumentTableEntry g_argument_table[] = {
{ lldb::eArgTypeCPUName, "cpu-name", lldb::CompletionType::eNoCompletion, {}, { nullptr, false }, "The name of a CPU." },
{ lldb::eArgTypeCPUFeatures, "cpu-features", lldb::CompletionType::eNoCompletion, {}, { nullptr, false }, "The CPU feature string." },
{ lldb::eArgTypeManagedPlugin, "managed-plugin", lldb::CompletionType::eNoCompletion, {}, { nullptr, false }, "Plugins managed by the PluginManager" },
+ { lldb::eArgTypeProtocol, "protocol", lldb::CompletionType::eNoCompletion, {}, { nullptr, false }, "The name of the protocol." },
// clang-format on
};
diff --git a/lldb/include/lldb/lldb-enumerations.h b/lldb/include/lldb/lldb-enumerations.h
index eeb7299a354e1..69e8671b6e21b 100644
--- a/lldb/include/lldb/lldb-enumerations.h
+++ b/lldb/include/lldb/lldb-enumerations.h
@@ -664,6 +664,7 @@ enum CommandArgumentType {
eArgTypeCPUName,
eArgTypeCPUFeatures,
eArgTypeManagedPlugin,
+ eArgTypeProtocol,
eArgTypeLastArg // Always keep this entry as the last entry in this
// enumeration!!
};
diff --git a/lldb/include/lldb/lldb-forward.h b/lldb/include/lldb/lldb-forward.h
index c664d1398f74d..558818e8e2309 100644
--- a/lldb/include/lldb/lldb-forward.h
+++ b/lldb/include/lldb/lldb-forward.h
@@ -164,13 +164,13 @@ class PersistentExpressionState;
class Platform;
class Process;
class ProcessAttachInfo;
-class ProcessLaunchInfo;
class ProcessInfo;
class ProcessInstanceInfo;
class ProcessInstanceInfoMatch;
class ProcessLaunchInfo;
class ProcessModID;
class Property;
+class ProtocolServer;
class Queue;
class QueueImpl;
class QueueItem;
@@ -391,6 +391,7 @@ typedef std::shared_ptr<lldb_private::Platform> PlatformSP;
typedef std::shared_ptr<lldb_private::Process> ProcessSP;
typedef std::shared_ptr<lldb_private::ProcessAttachInfo> ProcessAttachInfoSP;
typedef std::shared_ptr<lldb_private::ProcessLaunchInfo> ProcessLaunchInfoSP;
+typedef std::shared_ptr<lldb_private::ProtocolServer> ProtocolServerSP;
typedef std::weak_ptr<lldb_private::Process> ProcessWP;
typedef std::shared_ptr<lldb_private::RegisterCheckpoint> RegisterCheckpointSP;
typedef std::shared_ptr<lldb_private::RegisterContext> RegisterContextSP;
diff --git a/lldb/include/lldb/lldb-private-interfaces.h b/lldb/include/lldb/lldb-private-interfaces.h
index d366dbd1d7832..34eaaa8e581e9 100644
--- a/lldb/include/lldb/lldb-private-interfaces.h
+++ b/lldb/include/lldb/lldb-private-interfaces.h
@@ -81,6 +81,8 @@ typedef lldb::PlatformSP (*PlatformCreateInstance)(bool force,
typedef lldb::ProcessSP (*ProcessCreateInstance)(
lldb::TargetSP target_sp, lldb::ListenerSP listener_sp,
const FileSpec *crash_file_path, bool can_connect);
+typedef lldb::ProtocolServerSP (*ProtocolServerCreateInstance)(
+ Debugger &debugger);
typedef lldb::RegisterTypeBuilderSP (*RegisterTypeBuilderCreateInstance)(
Target &target);
typedef lldb::ScriptInterpreterSP (*ScriptInterpreterCreateInstance)(
diff --git a/lldb/source/Commands/CMakeLists.txt b/lldb/source/Commands/CMakeLists.txt
index 1ea51acec5f15..69e4c45f0b8e5 100644
--- a/lldb/source/Commands/CMakeLists.txt
+++ b/lldb/source/Commands/CMakeLists.txt
@@ -23,6 +23,7 @@ add_lldb_library(lldbCommands NO_PLUGIN_DEPENDENCIES
CommandObjectPlatform.cpp
CommandObjectPlugin.cpp
CommandObjectProcess.cpp
+ CommandObjectProtocolServer.cpp
CommandObjectQuit.cpp
CommandObjectRegexCommand.cpp
CommandObjectRegister.cpp
diff --git a/lldb/source/Commands/CommandObjectProtocolServer.cpp b/lldb/source/Commands/CommandObjectProtocolServer.cpp
new file mode 100644
index 0000000000000..420fc5fdddadb
--- /dev/null
+++ b/lldb/source/Commands/CommandObjectProtocolServer.cpp
@@ -0,0 +1,176 @@
+//===-- CommandObjectProtocolServer.cpp
+//----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "CommandObjectProtocolServer.h"
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Core/ProtocolServer.h"
+#include "lldb/Host/Socket.h"
+#include "lldb/Interpreter/CommandInterpreter.h"
+#include "lldb/Interpreter/CommandReturnObject.h"
+#include "lldb/Utility/UriParser.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/FormatAdapters.h"
+
+using namespace llvm;
+using namespace lldb;
+using namespace lldb_private;
+
+#define LLDB_OPTIONS_mcp
+#include "CommandOptions.inc"
+
+static std::vector<llvm::StringRef> GetSupportedProtocols() {
+ std::vector<llvm::StringRef> supported_protocols;
+ size_t i = 0;
+
+ for (llvm::StringRef protocol_name =
+ PluginManager::GetProtocolServerPluginNameAtIndex(i++);
+ !protocol_name.empty();
+ protocol_name = PluginManager::GetProtocolServerPluginNameAtIndex(i++)) {
+ supported_protocols.push_back(protocol_name);
+ }
+
+ return supported_protocols;
+}
+
+class CommandObjectProtocolServerStart : public CommandObjectParsed {
+public:
+ CommandObjectProtocolServerStart(CommandInterpreter &interpreter)
+ : CommandObjectParsed(interpreter, "protocol-server start",
+ "start protocol server",
+ "protocol-server start <protocol> <connection>") {
+ AddSimpleArgumentList(lldb::eArgTypeProtocol, eArgRepeatPlain);
+ AddSimpleArgumentList(lldb::eArgTypeConnectURL, eArgRepeatPlain);
+ }
+
+ ~CommandObjectProtocolServerStart() override = default;
+
+protected:
+ void DoExecute(Args &args, CommandReturnObject &result) override {
+ if (args.GetArgumentCount() < 1) {
+ result.AppendError("no protocol specified");
+ return;
+ }
+
+ llvm::StringRef protocol = args.GetArgumentAtIndex(0);
+ std::vector<llvm::StringRef> supported_protocols = GetSupportedProtocols();
+ if (llvm::find(supported_protocols, protocol) ==
+ supported_protocols.end()) {
+ result.AppendErrorWithFormatv(
+ "unsupported protocol: {0}. Supported protocols are: {1}", protocol,
+ llvm::join(GetSupportedProtocols(), ", "));
+ return;
+ }
+
+ if (args.GetArgumentCount() < 2) {
+ result.AppendError("no connection specified");
+ return;
+ }
+ llvm::StringRef connection_uri = args.GetArgumentAtIndex(1);
+
+ ProtocolServerSP server_sp = GetDebugger().GetProtocolServer(protocol);
+ if (!server_sp)
+ server_sp = ProtocolServer::Create(protocol, GetDebugger());
+
+ const char *connection_error =
+ "unsupported connection specifier, expected 'accept:///path' or "
+ "'listen://[host]:port', got '{0}'.";
+ auto uri = lldb_private::URI::Parse(connection_uri);
+ if (!uri) {
+ result.AppendErrorWithFormatv(connection_error, connection_uri);
+ return;
+ }
+
+ std::optional<Socket::ProtocolModePair> protocol_and_mode =
+ Socket::GetProtocolAndMode(uri->scheme);
+ if (!protocol_and_mode || protocol_and_mode->second != Socket::ModeAccept) {
+ result.AppendErrorWithFormatv(connection_error, connection_uri);
+ return;
+ }
+
+ ProtocolServer::Connection connection;
+ connection.protocol = protocol_and_mode->first;
+ connection.name =
+ formatv("[{0}]:{1}", uri->hostname.empty() ? "0.0.0.0" : uri->hostname,
+ uri->port.value_or(0));
+
+ if (llvm::Error error = server_sp->Start(connection)) {
+ result.AppendErrorWithFormatv("{0}", llvm::fmt_consume(std::move(error)));
+ return;
+ }
+
+ GetDebugger().AddProtocolServer(server_sp);
+
+ if (Socket *socket = server_sp->GetSocket()) {
+ std::string address =
+ llvm::join(socket->GetListeningConnectionURI(), ", ");
+ result.AppendMessageWithFormatv(
+ "{0} server started with connection listeners: {1}", protocol,
+ address);
+ }
+ }
+};
+
+class CommandObjectProtocolServerStop : public CommandObjectParsed {
+public:
+ CommandObjectProtocolServerStop(CommandInterpreter &interpreter)
+ : CommandObjectParsed(interpreter, "protocol-server stop",
+ "stop protocol server",
+ "protocol-server stop <protocol>") {
+ AddSimpleArgumentList(lldb::eArgTypeProtocol, eArgRepeatPlain);
+ }
+
+ ~CommandObjectProtocolServerStop() override = default;
+
+protected:
+ void DoExecute(Args &args, CommandReturnObject &result) override {
+ if (args.GetArgumentCount() < 1) {
+ result.AppendError("no protocol specified");
+ return;
+ }
+
+ llvm::StringRef protocol = args.GetArgumentAtIndex(0);
+ std::vector<llvm::StringRef> supported_protocols = GetSupportedProtocols();
+ if (llvm::find(supported_protocols, protocol) ==
+ supported_protocols.end()) {
+ result.AppendErrorWithFormatv(
+ "unsupported protocol: {0}. Supported protocols are: {1}", protocol,
+ llvm::join(GetSupportedProtocols(), ", "));
+ return;
+ }
+
+ Debugger &debugger = GetDebugger();
+
+ ProtocolServerSP server_sp = debugger.GetProtocolServer(protocol);
+ if (!server_sp) {
+ result.AppendError(
+ llvm::formatv("no {0} protocol server running", protocol).str());
+ return;
+ }
+
+ if (llvm::Error error = server_sp->Stop()) {
+ result.AppendErrorWithFormatv("{0}", llvm::fmt_consume(std::move(error)));
+ return;
+ }
+
+ debugger.RemoveProtocolServer(server_sp);
+ }
+};
+
+CommandObjectProtocolServer::CommandObjectProtocolServer(
+ CommandInterpreter &interpreter)
+ : CommandObjectMultiword(interpreter, "protocol-server",
+ "Start and stop a protocol server.",
+ "protocol-server") {
+ LoadSubCommand("start", CommandObjectSP(new CommandObjectProtocolServerStart(
+ interpreter)));
+ LoadSubCommand("stop", CommandObjectSP(
+ new CommandObjectProtocolServerStop(interpreter)));
+}
+
+CommandObjectProtocolServer::~CommandObjectProtocolServer() = default;
diff --git a/lldb/source/Commands/CommandObjectProtocolServer.h b/lldb/source/Commands/CommandObjectProtocolServer.h
new file mode 100644
index 0000000000000..3591216b014cb
--- /dev/null
+++ b/lldb/source/Commands/CommandObjectProtocolServer.h
@@ -0,0 +1,25 @@
+//===-- CommandObjectProtocolServer.h
+//------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_SOURCE_COMMANDS_COMMANDOBJECTPROTOCOLSERVER_H
+#define LLDB_SOURCE_COMMANDS_COMMANDOBJECTPROTOCOLSERVER_H
+
+#include "lldb/Interpreter/CommandObjectMultiword.h"
+
+namespace lldb_private {
+
+class CommandObjectProtocolServer : public CommandObjectMultiword {
+public:
+ CommandObjectProtocolServer(CommandInterpreter &interpreter);
+ ~CommandObjectProtocolServer() override;
+};
+
+} // namespace lldb_private
+
+#endif // LLDB_SOURCE_COMMANDS_COMMANDOBJECTMCP_H
diff --git a/lldb/source/Core/CMakeLists.txt b/lldb/source/Core/CMakeLists.txt
index d6b75bca7f2d6..df35bd5c025f3 100644
--- a/lldb/source/Core/CMakeLists.txt
+++ b/lldb/source/Core/CMakeLists.txt
@@ -46,6 +46,7 @@ add_lldb_library(lldbCore NO_PLUGIN_DEPENDENCIES
Opcode.cpp
PluginManager.cpp
Progress.cpp
+ ProtocolServer.cpp
Statusline.cpp
RichManglingContext.cpp
SearchFilter.cpp
diff --git a/lldb/source/Core/Debugger.cpp b/lldb/source/Core/Debugger.cpp
index c9935f2d745fa..33d1053fd8a65 100644
--- a/lldb/source/Core/Debugger.cpp
+++ b/lldb/source/Core/Debugger.cpp
@@ -16,6 +16,7 @@
#include "lldb/Core/ModuleSpec.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/Progress.h"
+#include "lldb/Core/ProtocolServer.h"
#include "lldb/Core/StreamAsynchronousIO.h"
#include "lldb/Core/Telemetry.h"
#include "lldb/DataFormatters/DataVisualization.h"
@@ -2375,3 +2376,26 @@ llvm::ThreadPoolInterface &Debugger::GetThreadPool() {
"Debugger::GetThreadPool called before Debugger::Initialize");
return *g_thread_pool;
}
+
+void Debugger::AddProtocolServer(lldb::ProtocolServerSP protocol_server_sp) {
+ assert(protocol_server_sp &&
+ GetProtocolServer(protocol_server_sp->GetPluginName()) == nullptr);
+ m_protocol_servers.push_back(protocol_server_sp);
+}
+
+void Debugger::RemoveProtocolServer(lldb::ProtocolServerSP protocol_server_sp) {
+ auto it = llvm::find(m_protocol_servers, protocol_server_sp);
+ if (it != m_protocol_servers.end())
+ m_protocol_servers.erase(it);
+}
+
+lldb::ProtocolServerSP
+Debugger::GetProtocolServer(llvm::StringRef protocol) const {
+ for (ProtocolServerSP protocol_server_sp : m_protocol_servers) {
+ if (!protocol_server_sp)
+ continue;
+ if (protocol_server_sp->GetPluginName() == protocol)
+ return protocol_server_sp;
+ }
+ return nullptr;
+}
diff --git a/lldb/source/Core/PluginManager.cpp b/lldb/source/Core/PluginManager.cpp
index dfa865929b64f..dc0731c04eef7 100644
--- a/lldb/source/Core/PluginManager.cpp
+++ b/lldb/source/Core/PluginManager.cpp
@@ -1152,6 +1152,38 @@ void PluginManager::AutoCompleteProcessName(llvm::StringRef name,
}
}
+#pragma mark ProtocolServer
+
+typedef PluginInstance<ProtocolServerCreateInstance> ProtocolServerInstance;
+typedef PluginInstances<ProtocolServerInstance> ProtocolServerInstances;
+
+static ProtocolServerInstances &GetProtocolServerInstances() {
+ static ProtocolServerInstances g_instances;
+ return g_instances;
+}
+
+bool PluginManager::RegisterPlugin(
+ llvm::StringRef name, llvm::StringRef description,
+ ProtocolServerCreateInstance create_callback) {
+ return GetProtocolServerInstances().RegisterPlugin(name, description,
+ create_callback);
+}
+
+bool PluginManager::UnregisterPlugin(
+ ProtocolServerCreateInstance create_callback) {
+ return GetProtocolServerInstances().UnregisterPlugin(create_callback);
+}
+
+llvm::StringRef
+PluginManager::GetProtocolServerPluginNameAtIndex(uint32_t idx) {
+ return GetProtocolServerInstances().GetNameAtIndex(idx);
+}
+
+ProtocolServerCreateInstance
+PluginManager::GetProtocolCreateCallbackForPluginName(llvm::StringRef name) {
+ return GetProtocolServerInstances().GetCallbackForName(name);
+}
+
#pragma mark RegisterTypeBuilder
struct RegisterTypeBuilderInstance
diff --git a/lldb/source/Core/ProtocolServer.cpp b/lldb/source/Core/ProtocolServer.cpp
new file mode 100644
index 0000000000000..d57a047afa7b2
--- /dev/null
+++ b/lldb/source/Core/ProtocolServer.cpp
@@ -0,0 +1,21 @@
+//===-- ProtocolServer.cpp ------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Core/ProtocolServer.h"
+#include "lldb/Core/PluginManager.h"
+
+using namespace lldb_private;
+using namespace lldb;
+
+ProtocolServerSP ProtocolServer::Create(llvm::StringRef name,
+ Debugger &debugger) {
+ if (ProtocolServerCreateInstance create_callback =
+ PluginManager::GetProtocolCreateCallbackForPluginName(name))
+ return create_callback(debugger);
+ return nullptr;
+}
diff --git a/lldb/source/Interpreter/CommandInterpreter.cpp b/lldb/source/Interpreter/CommandInterpreter.cpp
index 4f9ae104dedea..00c3472444d2e 100644
--- a/lldb/source/Interpreter/CommandInterpreter.cpp
+++ b/lldb/source/Interpreter/CommandInterpreter.cpp
@@ -30,6 +30,7 @@
#include "Commands/CommandObjectPlatform.h"
#include "Commands/CommandObjectPlugin.h"
#include "Commands/CommandObjectProcess.h"
+#include "Commands/CommandObjectProtocolServer.h"
#include "Commands/CommandObjectQuit.h"
#include "Commands/CommandObjectRegexCommand.h"
#include "Commands/CommandObjectRegister.h"
@@ -574,6 +575,7 @@ void CommandInterpreter::LoadCommandDictionary() {
REGISTER_COMMAND_OBJECT("platform", CommandObjectPlatform);
REGISTER_COMMAND_OBJECT("plugin", CommandObjectPlugin);
REGISTER_COMMAND_OBJECT("process", CommandObjectMultiwordProcess);
+ REGISTER_COMMAND_OBJECT("protocol-server", CommandObjectProtocolServer);
REGISTER_COMMAND_OBJECT("quit", CommandObjectQuit);
REGISTER_COMMAND_OBJECT("register", CommandObjectRegister);
REGISTER_COMMAND_OBJECT("scripting", CommandObjectMultiwordScripting);
diff --git a/lldb/source/Plugins/CMakeLists.txt b/lldb/source/Plugins/CMakeLists.txt
index 854f589f45ae0..08f444e7b15e8 100644
--- a/lldb/source/Plugins/CMakeLists.txt
+++ b/lldb/source/Plugins/CMakeLists.txt
@@ -27,6 +27,10 @@ add_subdirectory(TraceExporter)
add_subdirectory(TypeSystem)
add_subdirectory(UnwindAssembly)
+if(LLDB_ENABLE_PROTOCOL_SERVERS)
+ add_subdirectory(Protocol)
+endif()
+
set(LLDB_STRIPPED_PLUGINS)
get_property(LLDB_ALL_PLUGINS GLOBAL PROPERTY LLDB_PLUGINS)
diff --git a/lldb/source/Plugins/Protocol/CMakeLists.txt b/lldb/source/Plugins/Protocol/CMakeLists.txt
new file mode 100644
index 0000000000000..93b347d4cc9d8
--- /dev/null
+++ b/lldb/source/Plugins/Protocol/CMakeLists.txt
@@ -0,0 +1 @@
+add_subdirectory(MCP)
diff --git a/lldb/source/Plugins/Protocol/MCP/CMakeLists.txt b/lldb/source/Plugins/Protocol/MCP/CMakeLists.txt
new file mode 100644
index 0000000000000..db31a7a69cb33
--- /dev/null
+++ b/lldb/source/Plugins/Protocol/MCP/CMakeLists.txt
@@ -0,0 +1,13 @@
+add_lldb_library(lldbPluginProtocolServerMCP PLUGIN
+ MCPError.cpp
+ Protocol.cpp
+ ProtocolServerMCP.cpp
+ Tool.cpp
+
+ LINK_COMPONENTS
+ Support
+
+ LINK_LIBS
+ lldbHost
+ lldbUtility
+)
diff --git a/lldb/source/Plugins/Protocol/MCP/MCPError.cpp b/lldb/source/Plugins/Protocol/MCP/MCPError.cpp
new file mode 100644
index 0000000000000..5ed850066b659
--- /dev/null
+++ b/lldb/source/Plugins/Protocol/MCP/MCPError.cpp
@@ -0,0 +1,34 @@
+//===-- MCPError.cpp ------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "MCPError.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/raw_ostream.h"
+#include <system_error>
+
+namespace lldb_private::mcp {
+
+char MCPError::ID;
+
+MCPError::MCPError(std::string message, int64_t error_code)
+ : m_message(message), m_error_code(error_code) {}
+
+void MCPError::log(llvm::raw_ostream &OS) const { OS << m_message; }
+
+std::error_code MCPError::convertToErrorCode() const {
+ return llvm::inconvertibleErrorCode();
+}
+
+protocol::Error MCPError::toProtcolError() const {
+ protocol::Error error;
+ error.error.code = m_error_code;
+ error.error.message = m_message;
+ return error;
+}
+
+} // namespace lldb_private::mcp
diff --git a/lldb/source/Plugins/Protocol/MCP/MCPError.h b/lldb/source/Plugins/Protocol/MCP/MCPError.h
new file mode 100644
index 0000000000000..2a76a7b087e20
--- /dev/null
+++ b/lldb/source/Plugins/Protocol/MCP/MCPError.h
@@ -0,0 +1,33 @@
+//===-- MCPError.h --------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Protocol.h"
+#include "llvm/Support/Error.h"
+#include <string>
+
+namespace lldb_private::mcp {
+
+class MCPError : public llvm::ErrorInfo<MCPError> {
+public:
+ static char ID;
+
+ MCPError(std::string message, int64_t error_code);
+
+ void log(llvm::raw_ostream &OS) const override;
+ std::error_code convertToErrorCode() const override;
+
+ const std::string &getMessage() const { return m_message; }
+
+ protocol::Error toProtcolError() const;
+
+private:
+ std::string m_message;
+ int64_t m_error_code;
+};
+
+} // namespace lldb_private::mcp
diff --git a/lldb/source/Plugins/Protocol/MCP/Protocol.cpp b/lldb/source/Plugins/Protocol/MCP/Protocol.cpp
new file mode 100644
index 0000000000000..d66c931a0b284
--- /dev/null
+++ b/lldb/source/Plugins/Protocol/MCP/Protocol.cpp
@@ -0,0 +1,214 @@
+//===- Protocol.cpp -------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Protocol.h"
+#include "llvm/Support/JSON.h"
+
+using namespace llvm;
+
+namespace lldb_private::mcp::protocol {
+
+static bool mapRaw(const json::Value &Params, StringLiteral Prop,
+ std::optional<json::Value> &V, json::Path P) {
+ const auto *O = Params.getAsObject();
+ if (!O) {
+ P.report("expected object");
+ return false;
+ }
+ const json::Value *E = O->get(Prop);
+ if (E)
+ V = std::move(*E);
+ return true;
+}
+
+llvm::json::Value toJSON(const Request &R) {
+ json::Object Result{{"jsonrpc", "2.0"}, {"id", R.id}, {"method", R.method}};
+ if (R.params)
+ Result.insert({"params", R.params});
+ return Result;
+}
+
+bool fromJSON(const llvm::json::Value &V, Request &R, llvm::json::Path P) {
+ llvm::json::ObjectMapper O(V, P);
+ if (!O || !O.map("id", R.id) || !O.map("method", R.method))
+ return false;
+ return mapRaw(V, "params", R.params, P);
+}
+
+llvm::json::Value toJSON(const ErrorInfo &EI) {
+ llvm::json::Object Result{{"code", EI.code}, {"message", EI.message}};
+ if (EI.data)
+ Result.insert({"data", EI.data});
+ return Result;
+}
+
+bool fromJSON(const llvm::json::Value &V, ErrorInfo &EI, llvm::json::Path P) {
+ llvm::json::ObjectMapper O(V, P);
+ return O && O.map("code", EI.code) && O.map("message", EI.message) &&
+ O.mapOptional("data", EI.data);
+}
+
+llvm::json::Value toJSON(const Error &E) {
+ return json::Object{{"jsonrpc", "2.0"}, {"id", E.id}, {"error", E.error}};
+}
+
+bool fromJSON(const llvm::json::Value &V, Error &E, llvm::json::Path P) {
+ llvm::json::ObjectMapper O(V, P);
+ return O && O.map("id", E.id) && O.map("error", E.error);
+}
+
+llvm::json::Value toJSON(const Response &R) {
+ llvm::json::Object Result{{"jsonrpc", "2.0"}, {"id", R.id}};
+ if (R.result)
+ Result.insert({"result", R.result});
+ if (R.error)
+ Result.insert({"error", R.error});
+ return Result;
+}
+
+bool fromJSON(const llvm::json::Value &V, Response &R, llvm::json::Path P) {
+ llvm::json::ObjectMapper O(V, P);
+ if (!O || !O.map("id", R.id) || !O.map("error", R.error))
+ return false;
+ return mapRaw(V, "result", R.result, P);
+}
+
+llvm::json::Value toJSON(const Notification &N) {
+ llvm::json::Object Result{{"jsonrpc", "2.0"}, {"method", N.method}};
+ if (N.params)
+ Result.insert({"params", N.params});
+ return Result;
+}
+
+bool fromJSON(const llvm::json::Value &V, Notification &N, llvm::json::Path P) {
+ llvm::json::ObjectMapper O(V, P);
+ if (!O || !O.map("method", N.method))
+ return false;
+ auto *Obj = V.getAsObject();
+ if (!Obj)
+ return false;
+ if (auto *Params = Obj->get("params"))
+ N.params = *Params;
+ return true;
+}
+
+llvm::json::Value toJSON(const ToolCapability &TC) {
+ return llvm::json::Object{{"listChanged", TC.listChanged}};
+}
+
+bool fromJSON(const llvm::json::Value &V, ToolCapability &TC,
+ llvm::json::Path P) {
+ llvm::json::ObjectMapper O(V, P);
+ return O && O.map("listChanged", TC.listChanged);
+}
+
+llvm::json::Value toJSON(const Capabilities &C) {
+ return llvm::json::Object{{"tools", C.tools}};
+}
+
+bool fromJSON(const llvm::json::Value &V, Capabilities &C, llvm::json::Path P) {
+ llvm::json::ObjectMapper O(V, P);
+ return O && O.map("tools", C.tools);
+}
+
+llvm::json::Value toJSON(const TextContent &TC) {
+ return llvm::json::Object{{"type", "text"}, {"text", TC.text}};
+}
+
+bool fromJSON(const llvm::json::Value &V, TextContent &TC, llvm::json::Path P) {
+ llvm::json::ObjectMapper O(V, P);
+ return O && O.map("text", TC.text);
+}
+
+llvm::json::Value toJSON(const TextResult &TR) {
+ return llvm::json::Object{{"content", TR.content}, {"isError", TR.isError}};
+}
+
+bool fromJSON(const llvm::json::Value &V, TextResult &TR, llvm::json::Path P) {
+ llvm::json::ObjectMapper O(V, P);
+ return O && O.map("content", TR.content) && O.map("isError", TR.isError);
+}
+
+llvm::json::Value toJSON(const ToolDefinition &TD) {
+ llvm::json::Object Result{{"name", TD.name}};
+ if (TD.description)
+ Result.insert({"description", TD.description});
+ if (TD.inputSchema)
+ Result.insert({"inputSchema", TD.inputSchema});
+ return Result;
+}
+
+bool fromJSON(const llvm::json::Value &V, ToolDefinition &TD,
+ llvm::json::Path P) {
+
+ llvm::json::ObjectMapper O(V, P);
+ if (!O || !O.map("name", TD.name) ||
+ !O.mapOptional("description", TD.description))
+ return false;
+ return mapRaw(V, "inputSchema", TD.inputSchema, P);
+}
+
+llvm::json::Value toJSON(const Message &M) {
+ return std::visit([](auto &M) { return toJSON(M); }, M);
+}
+
+bool fromJSON(const llvm::json::Value &V, Message &M, llvm::json::Path P) {
+ const auto *O = V.getAsObject();
+ if (!O) {
+ P.report("expected object");
+ return false;
+ }
+
+ if (const json::Value *V = O->get("jsonrpc")) {
+ if (V->getAsString().value_or("") != "2.0") {
+ P.report("unsupported JSON RPC version");
+ return false;
+ }
+ } else {
+ P.report("not a valid JSON RPC message");
+ return false;
+ }
+
+ // A message without an ID is a Notification.
+ if (!O->get("id")) {
+ protocol::Notification N;
+ if (!fromJSON(V, N, P))
+ return false;
+ M = std::move(N);
+ return true;
+ }
+
+ if (O->get("error")) {
+ protocol::Error E;
+ if (!fromJSON(V, E, P))
+ return false;
+ M = std::move(E);
+ return true;
+ }
+
+ if (O->get("result")) {
+ protocol::Response R;
+ if (!fromJSON(V, R, P))
+ return false;
+ M = std::move(R);
+ return true;
+ }
+
+ if (O->get("method")) {
+ protocol::Request R;
+ if (!fromJSON(V, R, P))
+ return false;
+ M = std::move(R);
+ return true;
+ }
+
+ P.report("unrecognized message type");
+ return false;
+}
+
+} // namespace lldb_private::mcp::protocol
diff --git a/lldb/source/Plugins/Protocol/MCP/Protocol.h b/lldb/source/Plugins/Protocol/MCP/Protocol.h
new file mode 100644
index 0000000000000..e315899406573
--- /dev/null
+++ b/lldb/source/Plugins/Protocol/MCP/Protocol.h
@@ -0,0 +1,128 @@
+//===- Protocol.h ---------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains POD structs based on the MCP specification at
+// https://github.com/modelcontextprotocol/modelcontextprotocol/blob/main/schema/2024-11-05/schema.json
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_PLUGINS_PROTOCOL_MCP_PROTOCOL_H
+#define LLDB_PLUGINS_PROTOCOL_MCP_PROTOCOL_H
+
+#include "llvm/Support/JSON.h"
+#include <optional>
+#include <string>
+#include <variant>
+
+namespace lldb_private::mcp::protocol {
+
+static llvm::StringLiteral kVersion = "2024-11-05";
+
+/// A request that expects a response.
+struct Request {
+ uint64_t id = 0;
+ std::string method;
+ std::optional<llvm::json::Value> params;
+};
+
+llvm::json::Value toJSON(const Request &);
+bool fromJSON(const llvm::json::Value &, Request &, llvm::json::Path);
+
+struct ErrorInfo {
+ int64_t code = 0;
+ std::string message;
+ std::optional<std::string> data;
+};
+
+llvm::json::Value toJSON(const ErrorInfo &);
+bool fromJSON(const llvm::json::Value &, ErrorInfo &, llvm::json::Path);
+
+struct Error {
+ uint64_t id = 0;
+ ErrorInfo error;
+};
+
+llvm::json::Value toJSON(const Error &);
+bool fromJSON(const llvm::json::Value &, Error &, llvm::json::Path);
+
+struct Response {
+ uint64_t id = 0;
+ std::optional<llvm::json::Value> result;
+ std::optional<ErrorInfo> error;
+};
+
+llvm::json::Value toJSON(const Response &);
+bool fromJSON(const llvm::json::Value &, Response &, llvm::json::Path);
+
+/// A notification which does not expect a response.
+struct Notification {
+ std::string method;
+ std::optional<llvm::json::Value> params;
+};
+
+llvm::json::Value toJSON(const Notification &);
+bool fromJSON(const llvm::json::Value &, Notification &, llvm::json::Path);
+
+struct ToolCapability {
+ /// Whether this server supports notifications for changes to the tool list.
+ bool listChanged = false;
+};
+
+llvm::json::Value toJSON(const ToolCapability &);
+bool fromJSON(const llvm::json::Value &, ToolCapability &, llvm::json::Path);
+
+/// Capabilities that a server may support. Known capabilities are defined here,
+/// in this schema, but this is not a closed set: any server can define its own,
+/// additional capabilities.
+struct Capabilities {
+ /// Present if the server offers any tools to call.
+ ToolCapability tools;
+};
+
+llvm::json::Value toJSON(const Capabilities &);
+bool fromJSON(const llvm::json::Value &, Capabilities &, llvm::json::Path);
+
+/// Text provided to or from an LLM.
+struct TextContent {
+ /// The text content of the message.
+ std::string text;
+};
+
+llvm::json::Value toJSON(const TextContent &);
+bool fromJSON(const llvm::json::Value &, TextContent &, llvm::json::Path);
+
+struct TextResult {
+ std::vector<TextContent> content;
+ bool isError = false;
+};
+
+llvm::json::Value toJSON(const TextResult &);
+bool fromJSON(const llvm::json::Value &, TextResult &, llvm::json::Path);
+
+struct ToolDefinition {
+ /// Unique identifier for the tool.
+ std::string name;
+
+ /// Human-readable description.
+ std::optional<std::string> description;
+
+ // JSON Schema for the tool's parameters.
+ std::optional<llvm::json::Value> inputSchema;
+};
+
+llvm::json::Value toJSON(const ToolDefinition &);
+bool fromJSON(const llvm::json::Value &, ToolDefinition &, llvm::json::Path);
+
+using Message = std::variant<Request, Response, Notification, Error>;
+
+bool fromJSON(const llvm::json::Value &, Message &, llvm::json::Path);
+llvm::json::Value toJSON(const Message &);
+
+} // namespace lldb_private::mcp::protocol
+
+#endif
diff --git a/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.cpp b/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.cpp
new file mode 100644
index 0000000000000..029d4a887b0cc
--- /dev/null
+++ b/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.cpp
@@ -0,0 +1,327 @@
+//===- ProtocolServerMCP.cpp ----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "ProtocolServerMCP.h"
+#include "MCPError.h"
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Utility/LLDBLog.h"
+#include "lldb/Utility/Log.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/Threading.h"
+#include <thread>
+#include <variant>
+
+using namespace lldb_private;
+using namespace lldb_private::mcp;
+using namespace llvm;
+
+LLDB_PLUGIN_DEFINE(ProtocolServerMCP)
+
+static constexpr size_t kChunkSize = 1024;
+
+ProtocolServerMCP::ProtocolServerMCP(Debugger &debugger)
+ : ProtocolServer(), m_debugger(debugger) {
+ AddRequestHandler("initialize",
+ std::bind(&ProtocolServerMCP::InitializeHandler, this,
+ std::placeholders::_1));
+ AddRequestHandler("tools/list",
+ std::bind(&ProtocolServerMCP::ToolsListHandler, this,
+ std::placeholders::_1));
+ AddRequestHandler("tools/call",
+ std::bind(&ProtocolServerMCP::ToolsCallHandler, this,
+ std::placeholders::_1));
+ AddNotificationHandler(
+ "notifications/initialized", [](const protocol::Notification &) {
+ LLDB_LOG(GetLog(LLDBLog::Host), "MCP initialization complete");
+ });
+ AddTool(std::make_unique<LLDBCommandTool>(
+ "lldb_command", "Run an lldb command.", m_debugger));
+}
+
+ProtocolServerMCP::~ProtocolServerMCP() { llvm::consumeError(Stop()); }
+
+void ProtocolServerMCP::Initialize() {
+ PluginManager::RegisterPlugin(GetPluginNameStatic(),
+ GetPluginDescriptionStatic(), CreateInstance);
+}
+
+void ProtocolServerMCP::Terminate() {
+ PluginManager::UnregisterPlugin(CreateInstance);
+}
+
+lldb::ProtocolServerSP ProtocolServerMCP::CreateInstance(Debugger &debugger) {
+ return std::make_shared<ProtocolServerMCP>(debugger);
+}
+
+llvm::StringRef ProtocolServerMCP::GetPluginDescriptionStatic() {
+ return "MCP Server.";
+}
+
+llvm::Expected<protocol::Response>
+ProtocolServerMCP::Handle(protocol::Request request) {
+ auto it = m_request_handlers.find(request.method);
+ if (it != m_request_handlers.end()) {
+ llvm::Expected<protocol::Response> response = it->second(request);
+ if (!response)
+ return response;
+ response->id = request.id;
+ return *response;
+ }
+
+ return make_error<MCPError>(
+ llvm::formatv("no handler for request: {0}", request.method).str(), 1);
+}
+
+void ProtocolServerMCP::Handle(protocol::Notification notification) {
+ auto it = m_notification_handlers.find(notification.method);
+ if (it != m_notification_handlers.end()) {
+ it->second(notification);
+ return;
+ }
+
+ LLDB_LOG(GetLog(LLDBLog::Host), "MPC notification: {0} ({1})",
+ notification.method, notification.params);
+}
+
+void ProtocolServerMCP::AcceptCallback(std::unique_ptr<Socket> socket) {
+ LLDB_LOG(GetLog(LLDBLog::Host), "New MCP client ({0}) connected",
+ m_clients.size() + 1);
+
+ lldb::IOObjectSP io_sp = std::move(socket);
+ auto client_up = std::make_unique<Client>();
+ client_up->io_sp = io_sp;
+ Client *client = client_up.get();
+
+ Status status;
+ auto read_handle_up = m_loop.RegisterReadObject(
+ io_sp,
+ [this, client](MainLoopBase &loop) {
+ if (Error error = ReadCallback(*client)) {
+ LLDB_LOG_ERROR(GetLog(LLDBLog::Host), std::move(error), "{0}");
+ client->read_handle_up.reset();
+ }
+ },
+ status);
+ if (status.Fail())
+ return;
+
+ client_up->read_handle_up = std::move(read_handle_up);
+ m_clients.emplace_back(std::move(client_up));
+}
+
+llvm::Error ProtocolServerMCP::ReadCallback(Client &client) {
+ char chunk[kChunkSize];
+ size_t bytes_read = sizeof(chunk);
+ if (Status status = client.io_sp->Read(chunk, bytes_read); status.Fail())
+ return status.takeError();
+ client.buffer.append(chunk, bytes_read);
+
+ for (std::string::size_type pos;
+ (pos = client.buffer.find('\n')) != std::string::npos;) {
+ llvm::Expected<std::optional<protocol::Message>> message =
+ HandleData(StringRef(client.buffer.data(), pos));
+ client.buffer = client.buffer.erase(0, pos + 1);
+ if (!message)
+ return message.takeError();
+
+ if (*message) {
+ std::string Output;
+ llvm::raw_string_ostream OS(Output);
+ OS << llvm::formatv("{0}", toJSON(**message)) << '\n';
+ size_t num_bytes = Output.size();
+ return client.io_sp->Write(Output.data(), num_bytes).takeError();
+ }
+ }
+
+ return llvm::Error::success();
+}
+
+llvm::Error ProtocolServerMCP::Start(ProtocolServer::Connection connection) {
+ std::lock_guard<std::mutex> guard(m_server_mutex);
+
+ if (m_running)
+ return llvm::createStringError("server already running");
+
+ Status status;
+ m_listener = Socket::Create(connection.protocol, status);
+ if (status.Fail())
+ return status.takeError();
+
+ status = m_listener->Listen(connection.name, /*backlog=*/5);
+ if (status.Fail())
+ return status.takeError();
+
+ std::string address =
+ llvm::join(m_listener->GetListeningConnectionURI(), ", ");
+ auto handles =
+ m_listener->Accept(m_loop, std::bind(&ProtocolServerMCP::AcceptCallback,
+ this, std::placeholders::_1));
+ if (llvm::Error error = handles.takeError())
+ return error;
+
+ m_listen_handlers = std::move(*handles);
+ m_loop_thread = std::thread([=] {
+ llvm::set_thread_name(
+ llvm::formatv("debugger-{0}.mcp.runloop", m_debugger.GetID()));
+ m_loop.Run();
+ });
+
+ return llvm::Error::success();
+}
+
+llvm::Error ProtocolServerMCP::Stop() {
+ {
+ std::lock_guard<std::mutex> guard(m_server_mutex);
+ m_running = false;
+ }
+
+ // Stop the main loop.
+ m_loop.AddPendingCallback(
+ [](MainLoopBase &loop) { loop.RequestTermination(); });
+
+ // Wait for the main loop to exit.
+ if (m_loop_thread.joinable())
+ m_loop_thread.join();
+
+ {
+ std::lock_guard<std::mutex> guard(m_server_mutex);
+ m_listener.reset();
+ m_listen_handlers.clear();
+ m_clients.clear();
+ }
+
+ return llvm::Error::success();
+}
+
+llvm::Expected<std::optional<protocol::Message>>
+ProtocolServerMCP::HandleData(llvm::StringRef data) {
+ auto message = llvm::json::parse<protocol::Message>(/*JSON=*/data);
+ if (!message)
+ return message.takeError();
+
+ if (const protocol::Request *request =
+ std::get_if<protocol::Request>(&(*message))) {
+ llvm::Expected<protocol::Response> response = Handle(*request);
+
+ // Handle failures by converting them into an Error message.
+ if (!response) {
+ protocol::Error protocol_error;
+ llvm::handleAllErrors(
+ response.takeError(),
+ [&](const MCPError &err) { protocol_error = err.toProtcolError(); },
+ [&](const llvm::ErrorInfoBase &err) {
+ protocol_error.error.code = -1;
+ protocol_error.error.message = err.message();
+ });
+ protocol_error.id = request->id;
+ return protocol_error;
+ }
+
+ return *response;
+ }
+
+ if (const protocol::Notification *notification =
+ std::get_if<protocol::Notification>(&(*message))) {
+ Handle(*notification);
+ return std::nullopt;
+ }
+
+ if (std::get_if<protocol::Error>(&(*message)))
+ return llvm::createStringError("unexpected MCP message: error");
+
+ if (std::get_if<protocol::Response>(&(*message)))
+ return llvm::createStringError("unexpected MCP message: response");
+
+ llvm_unreachable("all message types handled");
+}
+
+protocol::Capabilities ProtocolServerMCP::GetCapabilities() {
+ protocol::Capabilities capabilities;
+ capabilities.tools.listChanged = true;
+ return capabilities;
+}
+
+void ProtocolServerMCP::AddTool(std::unique_ptr<Tool> tool) {
+ std::lock_guard<std::mutex> guard(m_server_mutex);
+
+ if (!tool)
+ return;
+ m_tools[tool->GetName()] = std::move(tool);
+}
+
+void ProtocolServerMCP::AddRequestHandler(llvm::StringRef method,
+ RequestHandler handler) {
+ std::lock_guard<std::mutex> guard(m_server_mutex);
+ m_request_handlers[method] = std::move(handler);
+}
+
+void ProtocolServerMCP::AddNotificationHandler(llvm::StringRef method,
+ NotificationHandler handler) {
+ std::lock_guard<std::mutex> guard(m_server_mutex);
+ m_notification_handlers[method] = std::move(handler);
+}
+
+llvm::Expected<protocol::Response>
+ProtocolServerMCP::InitializeHandler(const protocol::Request &request) {
+ protocol::Response response;
+ response.result.emplace(llvm::json::Object{
+ {"protocolVersion", protocol::kVersion},
+ {"capabilities", GetCapabilities()},
+ {"serverInfo",
+ llvm::json::Object{{"name", kName}, {"version", kVersion}}}});
+ return response;
+}
+
+llvm::Expected<protocol::Response>
+ProtocolServerMCP::ToolsListHandler(const protocol::Request &request) {
+ protocol::Response response;
+
+ llvm::json::Array tools;
+ for (const auto &tool : m_tools)
+ tools.emplace_back(toJSON(tool.second->GetDefinition()));
+
+ response.result.emplace(llvm::json::Object{{"tools", std::move(tools)}});
+
+ return response;
+}
+
+llvm::Expected<protocol::Response>
+ProtocolServerMCP::ToolsCallHandler(const protocol::Request &request) {
+ protocol::Response response;
+
+ if (!request.params)
+ return llvm::createStringError("no tool parameters");
+
+ const json::Object *param_obj = request.params->getAsObject();
+ if (!param_obj)
+ return llvm::createStringError("no tool parameters");
+
+ const json::Value *name = param_obj->get("name");
+ if (!name)
+ return llvm::createStringError("no tool name");
+
+ llvm::StringRef tool_name = name->getAsString().value_or("");
+ if (tool_name.empty())
+ return llvm::createStringError("no tool name");
+
+ auto it = m_tools.find(tool_name);
+ if (it == m_tools.end())
+ return llvm::createStringError(llvm::formatv("no tool \"{0}\"", tool_name));
+
+ const json::Value *args = param_obj->get("arguments");
+ if (!args)
+ return llvm::createStringError("no tool arguments");
+
+ llvm::Expected<protocol::TextResult> text_result = it->second->Call(*args);
+ if (!text_result)
+ return text_result.takeError();
+
+ response.result.emplace(toJSON(*text_result));
+
+ return response;
+}
diff --git a/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.h b/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.h
new file mode 100644
index 0000000000000..52bb92a04a802
--- /dev/null
+++ b/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.h
@@ -0,0 +1,100 @@
+//===- ProtocolServerMCP.h ------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_PLUGINS_PROTOCOL_MCP_PROTOCOLSERVERMCP_H
+#define LLDB_PLUGINS_PROTOCOL_MCP_PROTOCOLSERVERMCP_H
+
+#include "Protocol.h"
+#include "Tool.h"
+#include "lldb/Core/ProtocolServer.h"
+#include "lldb/Host/MainLoop.h"
+#include "lldb/Host/Socket.h"
+#include "llvm/ADT/StringMap.h"
+#include <thread>
+
+namespace lldb_private::mcp {
+
+class ProtocolServerMCP : public ProtocolServer {
+public:
+ ProtocolServerMCP(Debugger &debugger);
+ virtual ~ProtocolServerMCP() override;
+
+ virtual llvm::Error Start(ProtocolServer::Connection connection) override;
+ virtual llvm::Error Stop() override;
+
+ static void Initialize();
+ static void Terminate();
+
+ static llvm::StringRef GetPluginNameStatic() { return "MCP"; }
+ static llvm::StringRef GetPluginDescriptionStatic();
+
+ static lldb::ProtocolServerSP CreateInstance(Debugger &debugger);
+
+ llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); }
+
+ Socket *GetSocket() const override { return m_listener.get(); }
+
+protected:
+ using RequestHandler = std::function<llvm::Expected<protocol::Response>(
+ const protocol::Request &)>;
+ using NotificationHandler =
+ std::function<void(const protocol::Notification &)>;
+
+ void AddTool(std::unique_ptr<Tool> tool);
+ void AddRequestHandler(llvm::StringRef method, RequestHandler handler);
+ void AddNotificationHandler(llvm::StringRef method,
+ NotificationHandler handler);
+
+private:
+ void AcceptCallback(std::unique_ptr<Socket> socket);
+
+ llvm::Expected<std::optional<protocol::Message>>
+ HandleData(llvm::StringRef data);
+
+ llvm::Expected<protocol::Response> Handle(protocol::Request request);
+ void Handle(protocol::Notification notification);
+
+ llvm::Expected<protocol::Response>
+ InitializeHandler(const protocol::Request &);
+ llvm::Expected<protocol::Response>
+ ToolsListHandler(const protocol::Request &);
+ llvm::Expected<protocol::Response>
+ ToolsCallHandler(const protocol::Request &);
+
+ protocol::Capabilities GetCapabilities();
+
+ llvm::StringLiteral kName = "lldb-mcp";
+ llvm::StringLiteral kVersion = "0.1.0";
+
+ Debugger &m_debugger;
+
+ bool m_running = false;
+
+ MainLoop m_loop;
+ std::thread m_loop_thread;
+
+ std::unique_ptr<Socket> m_listener;
+ std::vector<MainLoopBase::ReadHandleUP> m_listen_handlers;
+
+ struct Client {
+ lldb::IOObjectSP io_sp;
+ MainLoopBase::ReadHandleUP read_handle_up;
+ std::string buffer;
+ };
+ llvm::Error ReadCallback(Client &client);
+ std::vector<std::unique_ptr<Client>> m_clients;
+
+ std::mutex m_server_mutex;
+ llvm::StringMap<std::unique_ptr<Tool>> m_tools;
+
+ llvm::StringMap<RequestHandler> m_request_handlers;
+ llvm::StringMap<NotificationHandler> m_notification_handlers;
+};
+} // namespace lldb_private::mcp
+
+#endif
diff --git a/lldb/source/Plugins/Protocol/MCP/Tool.cpp b/lldb/source/Plugins/Protocol/MCP/Tool.cpp
new file mode 100644
index 0000000000000..de8fcc8f3cb4c
--- /dev/null
+++ b/lldb/source/Plugins/Protocol/MCP/Tool.cpp
@@ -0,0 +1,81 @@
+//===- Tool.cpp -----------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Tool.h"
+#include "lldb/Interpreter/CommandInterpreter.h"
+#include "lldb/Interpreter/CommandReturnObject.h"
+
+using namespace lldb_private::mcp;
+using namespace llvm;
+
+struct LLDBCommandToolArguments {
+ std::string arguments;
+};
+
+bool fromJSON(const llvm::json::Value &V, LLDBCommandToolArguments &A,
+ llvm::json::Path P) {
+ llvm::json::ObjectMapper O(V, P);
+ return O && O.map("arguments", A.arguments);
+}
+
+Tool::Tool(std::string name, std::string description)
+ : m_name(std::move(name)), m_description(std::move(description)) {}
+
+protocol::ToolDefinition Tool::GetDefinition() const {
+ protocol::ToolDefinition definition;
+ definition.name = m_name;
+ definition.description.emplace(m_description);
+
+ if (std::optional<llvm::json::Value> input_schema = GetSchema())
+ definition.inputSchema = *input_schema;
+
+ return definition;
+}
+
+LLDBCommandTool::LLDBCommandTool(std::string name, std::string description,
+ Debugger &debugger)
+ : Tool(std::move(name), std::move(description)), m_debugger(debugger) {}
+
+llvm::Expected<protocol::TextResult>
+LLDBCommandTool::Call(const llvm::json::Value &args) {
+ llvm::json::Path::Root root;
+
+ LLDBCommandToolArguments arguments;
+ if (!fromJSON(args, arguments, root))
+ return root.getError();
+
+ // FIXME: Disallow certain commands and their aliases.
+ CommandReturnObject result(/*colors=*/false);
+ m_debugger.GetCommandInterpreter().HandleCommand(arguments.arguments.c_str(),
+ eLazyBoolYes, result);
+
+ std::string output;
+ llvm::StringRef output_str = result.GetOutputString();
+ if (!output_str.empty())
+ output += output_str.str();
+
+ std::string err_str = result.GetErrorString();
+ if (!err_str.empty()) {
+ if (!output.empty())
+ output += '\n';
+ output += err_str;
+ }
+
+ mcp::protocol::TextResult text_result;
+ text_result.content.emplace_back(mcp::protocol::TextContent{{output}});
+ text_result.isError = !result.Succeeded();
+ return text_result;
+}
+
+std::optional<llvm::json::Value> LLDBCommandTool::GetSchema() const {
+ llvm::json::Object str_type{{"type", "string"}};
+ llvm::json::Object properties{{"arguments", std::move(str_type)}};
+ llvm::json::Object schema{{"type", "object"},
+ {"properties", std::move(properties)}};
+ return schema;
+}
diff --git a/lldb/source/Plugins/Protocol/MCP/Tool.h b/lldb/source/Plugins/Protocol/MCP/Tool.h
new file mode 100644
index 0000000000000..57a5125813b76
--- /dev/null
+++ b/lldb/source/Plugins/Protocol/MCP/Tool.h
@@ -0,0 +1,56 @@
+//===- Tool.h -------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_PLUGINS_PROTOCOL_MCP_TOOL_H
+#define LLDB_PLUGINS_PROTOCOL_MCP_TOOL_H
+
+#include "Protocol.h"
+#include "lldb/Core/Debugger.h"
+#include "llvm/Support/JSON.h"
+#include <string>
+
+namespace lldb_private::mcp {
+
+class Tool {
+public:
+ Tool(std::string name, std::string description);
+ virtual ~Tool() = default;
+
+ virtual llvm::Expected<protocol::TextResult>
+ Call(const llvm::json::Value &args) = 0;
+
+ virtual std::optional<llvm::json::Value> GetSchema() const {
+ return std::nullopt;
+ }
+
+ protocol::ToolDefinition GetDefinition() const;
+
+ const std::string &GetName() { return m_name; }
+
+private:
+ std::string m_name;
+ std::string m_description;
+};
+
+class LLDBCommandTool : public mcp::Tool {
+public:
+ LLDBCommandTool(std::string name, std::string description,
+ Debugger &debugger);
+ ~LLDBCommandTool() = default;
+
+ virtual llvm::Expected<protocol::TextResult>
+ Call(const llvm::json::Value &args) override;
+
+ virtual std::optional<llvm::json::Value> GetSchema() const override;
+
+private:
+ Debugger &m_debugger;
+};
+} // namespace lldb_private::mcp
+
+#endif
diff --git a/lldb/unittests/CMakeLists.txt b/lldb/unittests/CMakeLists.txt
index 6eaaa4f4c8c98..b48b9bafe3bc3 100644
--- a/lldb/unittests/CMakeLists.txt
+++ b/lldb/unittests/CMakeLists.txt
@@ -78,6 +78,10 @@ add_subdirectory(Utility)
add_subdirectory(Thread)
add_subdirectory(ValueObject)
+if(LLDB_ENABLE_PROTOCOL_SERVERS)
+ add_subdirectory(Protocol)
+endif()
+
if(LLDB_CAN_USE_DEBUGSERVER AND LLDB_TOOL_DEBUGSERVER_BUILD AND NOT LLDB_USE_SYSTEM_DEBUGSERVER)
add_subdirectory(debugserver)
endif()
diff --git a/lldb/unittests/DAP/ProtocolTypesTest.cpp b/lldb/unittests/DAP/ProtocolTypesTest.cpp
index 9c93eb8c94b05..085348ffc519d 100644
--- a/lldb/unittests/DAP/ProtocolTypesTest.cpp
+++ b/lldb/unittests/DAP/ProtocolTypesTest.cpp
@@ -9,6 +9,7 @@
#include "Protocol/ProtocolTypes.h"
#include "Protocol/ProtocolEvents.h"
#include "Protocol/ProtocolRequests.h"
+#include "TestingSupport/TestUtilities.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/JSON.h"
#include "llvm/Testing/Support/Error.h"
@@ -20,6 +21,7 @@ using namespace llvm;
using namespace lldb;
using namespace lldb_dap;
using namespace lldb_dap::protocol;
+using lldb_private::roundtripJSON;
using llvm::json::parse;
using llvm::json::Value;
@@ -28,15 +30,6 @@ static std::string pp(const json::Value &E) {
return formatv("{0:2}", E).str();
}
-template <typename T> static llvm::Expected<T> roundtrip(const T &input) {
- llvm::json::Value value = toJSON(input);
- llvm::json::Path::Root root;
- T output;
- if (!fromJSON(value, output, root))
- return root.getError();
- return output;
-}
-
TEST(ProtocolTypesTest, ExceptionBreakpointsFilter) {
ExceptionBreakpointsFilter filter;
filter.filter = "testFilter";
@@ -47,7 +40,7 @@ TEST(ProtocolTypesTest, ExceptionBreakpointsFilter) {
filter.conditionDescription = "Condition for test filter";
llvm::Expected<ExceptionBreakpointsFilter> deserialized_filter =
- roundtrip(filter);
+ roundtripJSON(filter);
ASSERT_THAT_EXPECTED(deserialized_filter, llvm::Succeeded());
EXPECT_EQ(filter.filter, deserialized_filter->filter);
@@ -66,7 +59,7 @@ TEST(ProtocolTypesTest, Source) {
source.sourceReference = 12345;
source.presentationHint = Source::eSourcePresentationHintEmphasize;
- llvm::Expected<Source> deserialized_source = roundtrip(source);
+ llvm::Expected<Source> deserialized_source = roundtripJSON(source);
ASSERT_THAT_EXPECTED(deserialized_source, llvm::Succeeded());
EXPECT_EQ(source.name, deserialized_source->name);
@@ -83,7 +76,7 @@ TEST(ProtocolTypesTest, ColumnDescriptor) {
column.type = eColumnTypeString;
column.width = 20;
- llvm::Expected<ColumnDescriptor> deserialized_column = roundtrip(column);
+ llvm::Expected<ColumnDescriptor> deserialized_column = roundtripJSON(column);
ASSERT_THAT_EXPECTED(deserialized_column, llvm::Succeeded());
EXPECT_EQ(column.attributeName, deserialized_column->attributeName);
@@ -101,7 +94,7 @@ TEST(ProtocolTypesTest, BreakpointMode) {
mode.appliesTo = {eBreakpointModeApplicabilitySource,
eBreakpointModeApplicabilityException};
- llvm::Expected<BreakpointMode> deserialized_mode = roundtrip(mode);
+ llvm::Expected<BreakpointMode> deserialized_mode = roundtripJSON(mode);
ASSERT_THAT_EXPECTED(deserialized_mode, llvm::Succeeded());
EXPECT_EQ(mode.mode, deserialized_mode->mode);
@@ -125,7 +118,8 @@ TEST(ProtocolTypesTest, Breakpoint) {
breakpoint.offset = 4;
breakpoint.reason = BreakpointReason::eBreakpointReasonPending;
- llvm::Expected<Breakpoint> deserialized_breakpoint = roundtrip(breakpoint);
+ llvm::Expected<Breakpoint> deserialized_breakpoint =
+ roundtripJSON(breakpoint);
ASSERT_THAT_EXPECTED(deserialized_breakpoint, llvm::Succeeded());
EXPECT_EQ(breakpoint.id, deserialized_breakpoint->id);
@@ -157,7 +151,7 @@ TEST(ProtocolTypesTest, SourceBreakpoint) {
source_breakpoint.mode = "hardware";
llvm::Expected<SourceBreakpoint> deserialized_source_breakpoint =
- roundtrip(source_breakpoint);
+ roundtripJSON(source_breakpoint);
ASSERT_THAT_EXPECTED(deserialized_source_breakpoint, llvm::Succeeded());
EXPECT_EQ(source_breakpoint.line, deserialized_source_breakpoint->line);
@@ -178,7 +172,7 @@ TEST(ProtocolTypesTest, FunctionBreakpoint) {
function_breakpoint.hitCondition = "3";
llvm::Expected<FunctionBreakpoint> deserialized_function_breakpoint =
- roundtrip(function_breakpoint);
+ roundtripJSON(function_breakpoint);
ASSERT_THAT_EXPECTED(deserialized_function_breakpoint, llvm::Succeeded());
EXPECT_EQ(function_breakpoint.name, deserialized_function_breakpoint->name);
@@ -196,7 +190,7 @@ TEST(ProtocolTypesTest, DataBreakpoint) {
data_breakpoint_info.hitCondition = "10";
llvm::Expected<DataBreakpoint> deserialized_data_breakpoint_info =
- roundtrip(data_breakpoint_info);
+ roundtripJSON(data_breakpoint_info);
ASSERT_THAT_EXPECTED(deserialized_data_breakpoint_info, llvm::Succeeded());
EXPECT_EQ(data_breakpoint_info.dataId,
@@ -233,9 +227,9 @@ TEST(ProtocolTypesTest, Capabilities) {
{eBreakpointModeApplicabilitySource}}};
capabilities.lldbExtVersion = "1.0.0";
- // Perform roundtrip serialization and deserialization.
+ // Perform roundtripJSON serialization and deserialization.
llvm::Expected<Capabilities> deserialized_capabilities =
- roundtrip(capabilities);
+ roundtripJSON(capabilities);
ASSERT_THAT_EXPECTED(deserialized_capabilities, llvm::Succeeded());
// Verify supported features.
@@ -316,7 +310,7 @@ TEST(ProtocolTypesTest, Scope) {
source.presentationHint = Source::eSourcePresentationHintNormal;
scope.source = source;
- llvm::Expected<Scope> deserialized_scope = roundtrip(scope);
+ llvm::Expected<Scope> deserialized_scope = roundtripJSON(scope);
ASSERT_THAT_EXPECTED(deserialized_scope, llvm::Succeeded());
EXPECT_EQ(scope.name, deserialized_scope->name);
EXPECT_EQ(scope.presentationHint, deserialized_scope->presentationHint);
@@ -755,7 +749,7 @@ TEST(ProtocolTypesTest, StepInTarget) {
target.endLine = 32;
target.endColumn = 23;
- llvm::Expected<StepInTarget> deserialized_target = roundtrip(target);
+ llvm::Expected<StepInTarget> deserialized_target = roundtripJSON(target);
ASSERT_THAT_EXPECTED(deserialized_target, llvm::Succeeded());
EXPECT_EQ(target.id, deserialized_target->id);
@@ -797,4 +791,4 @@ TEST(ProtocolTypesTest, ReadMemoryResponseBody) {
R"({ "address": "0xdeadbeef", "data": "aGVsbG8gd29ybGQh", "unreadableBytes": 1})");
ASSERT_THAT_EXPECTED(expected, llvm::Succeeded());
EXPECT_EQ(pp(*expected), pp(response));
-}
\ No newline at end of file
+}
diff --git a/lldb/unittests/Protocol/CMakeLists.txt b/lldb/unittests/Protocol/CMakeLists.txt
new file mode 100644
index 0000000000000..801662b0544d8
--- /dev/null
+++ b/lldb/unittests/Protocol/CMakeLists.txt
@@ -0,0 +1,12 @@
+add_lldb_unittest(ProtocolTests
+ ProtocolMCPTest.cpp
+ ProtocolMCPServerTest.cpp
+
+ LINK_LIBS
+ lldbCore
+ lldbUtility
+ lldbHost
+ lldbPluginPlatformMacOSX
+ lldbPluginProtocolServerMCP
+ LLVMTestingSupport
+ )
diff --git a/lldb/unittests/Protocol/ProtocolMCPServerTest.cpp b/lldb/unittests/Protocol/ProtocolMCPServerTest.cpp
new file mode 100644
index 0000000000000..72b8c7b1fd825
--- /dev/null
+++ b/lldb/unittests/Protocol/ProtocolMCPServerTest.cpp
@@ -0,0 +1,291 @@
+//===-- ProtocolServerMCPTest.cpp -----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Plugins/Platform/MacOSX/PlatformRemoteMacOSX.h"
+#include "Plugins/Protocol/MCP/ProtocolServerMCP.h"
+#include "TestingSupport/Host/SocketTestUtilities.h"
+#include "TestingSupport/SubsystemRAII.h"
+#include "lldb/Core/ProtocolServer.h"
+#include "lldb/Host/FileSystem.h"
+#include "lldb/Host/HostInfo.h"
+#include "lldb/Host/JSONTransport.h"
+#include "lldb/Host/Socket.h"
+#include "llvm/Testing/Support/Error.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace lldb;
+using namespace lldb_private;
+using namespace lldb_private::mcp::protocol;
+
+namespace {
+class TestProtocolServerMCP : public lldb_private::mcp::ProtocolServerMCP {
+public:
+ using ProtocolServerMCP::AddNotificationHandler;
+ using ProtocolServerMCP::AddRequestHandler;
+ using ProtocolServerMCP::AddTool;
+ using ProtocolServerMCP::GetSocket;
+ using ProtocolServerMCP::ProtocolServerMCP;
+};
+
+class TestJSONTransport : public lldb_private::JSONRPCTransport {
+public:
+ using JSONRPCTransport::JSONRPCTransport;
+ using JSONRPCTransport::ReadImpl;
+ using JSONRPCTransport::WriteImpl;
+};
+
+/// Test tool that returns it argument as text.
+class TestTool : public mcp::Tool {
+public:
+ using mcp::Tool::Tool;
+
+ virtual llvm::Expected<mcp::protocol::TextResult>
+ Call(const llvm::json::Value &args) override {
+ std::string argument;
+ if (const json::Object *args_obj = args.getAsObject()) {
+ if (const json::Value *s = args_obj->get("arguments")) {
+ argument = s->getAsString().value_or("");
+ }
+ }
+
+ mcp::protocol::TextResult text_result;
+ text_result.content.emplace_back(mcp::protocol::TextContent{{argument}});
+ return text_result;
+ }
+};
+
+/// Test tool that returns an error.
+class ErrorTool : public mcp::Tool {
+public:
+ using mcp::Tool::Tool;
+
+ virtual llvm::Expected<mcp::protocol::TextResult>
+ Call(const llvm::json::Value &args) override {
+ return llvm::createStringError("error");
+ }
+};
+
+/// Test tool that fails but doesn't return an error.
+class FailTool : public mcp::Tool {
+public:
+ using mcp::Tool::Tool;
+
+ virtual llvm::Expected<mcp::protocol::TextResult>
+ Call(const llvm::json::Value &args) override {
+ mcp::protocol::TextResult text_result;
+ text_result.content.emplace_back(mcp::protocol::TextContent{{"failed"}});
+ text_result.isError = true;
+ return text_result;
+ }
+};
+
+class ProtocolServerMCPTest : public ::testing::Test {
+public:
+ SubsystemRAII<FileSystem, HostInfo, PlatformRemoteMacOSX, Socket> subsystems;
+ DebuggerSP m_debugger_sp;
+
+ lldb::IOObjectSP m_io_sp;
+ std::unique_ptr<TestJSONTransport> m_transport_up;
+ std::unique_ptr<TestProtocolServerMCP> m_server_up;
+
+ static constexpr llvm::StringLiteral k_localhost = "localhost";
+
+ llvm::Error Write(llvm::StringRef message) {
+ return m_transport_up->WriteImpl(llvm::formatv("{0}\n", message).str());
+ }
+
+ llvm::Expected<std::string> Read() {
+ return m_transport_up->ReadImpl(std::chrono::milliseconds(100));
+ }
+
+ void SetUp() {
+ // Create a debugger.
+ ArchSpec arch("arm64-apple-macosx-");
+ Platform::SetHostPlatform(
+ PlatformRemoteMacOSX::CreateInstance(true, &arch));
+ m_debugger_sp = Debugger::CreateInstance();
+
+ // Create & start the server.
+ ProtocolServer::Connection connection;
+ connection.protocol = Socket::SocketProtocol::ProtocolTcp;
+ connection.name = llvm::formatv("{0}:0", k_localhost).str();
+ m_server_up = std::make_unique<TestProtocolServerMCP>(*m_debugger_sp);
+ m_server_up->AddTool(std::make_unique<TestTool>("test", "test tool"));
+ ASSERT_THAT_ERROR(m_server_up->Start(connection), llvm::Succeeded());
+
+ // Connect to the server over a TCP socket.
+ auto connect_socket_up = std::make_unique<TCPSocket>(true);
+ ASSERT_THAT_ERROR(connect_socket_up
+ ->Connect(llvm::formatv("{0}:{1}", k_localhost,
+ static_cast<TCPSocket *>(
+ m_server_up->GetSocket())
+ ->GetLocalPortNumber())
+ .str())
+ .ToError(),
+ llvm::Succeeded());
+
+ // Set up JSON transport for the client.
+ m_io_sp = std::move(connect_socket_up);
+ m_transport_up = std::make_unique<TestJSONTransport>(m_io_sp, m_io_sp);
+ }
+
+ void TearDown() {
+ // Stop the server.
+ ASSERT_THAT_ERROR(m_server_up->Stop(), llvm::Succeeded());
+ }
+};
+
+} // namespace
+
+TEST_F(ProtocolServerMCPTest, Intialization) {
+ llvm::StringLiteral request =
+ R"json({"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"claude-ai","version":"0.1.0"}},"jsonrpc":"2.0","id":0})json";
+ llvm::StringLiteral response =
+ R"json({"jsonrpc":"2.0","id":0,"result":{"capabilities":{"tools":{"listChanged":true}},"protocolVersion":"2024-11-05","serverInfo":{"name":"lldb-mcp","version":"0.1.0"}}})json";
+
+ ASSERT_THAT_ERROR(Write(request), llvm::Succeeded());
+
+ llvm::Expected<std::string> response_str = Read();
+ ASSERT_THAT_EXPECTED(response_str, llvm::Succeeded());
+
+ llvm::Expected<json::Value> response_json = json::parse(*response_str);
+ ASSERT_THAT_EXPECTED(response_json, llvm::Succeeded());
+
+ llvm::Expected<json::Value> expected_json = json::parse(response);
+ ASSERT_THAT_EXPECTED(expected_json, llvm::Succeeded());
+
+ EXPECT_EQ(*response_json, *expected_json);
+}
+
+TEST_F(ProtocolServerMCPTest, ToolsList) {
+ llvm::StringLiteral request =
+ R"json({"method":"tools/list","params":{},"jsonrpc":"2.0","id":1})json";
+ llvm::StringLiteral response =
+ R"json({"id":1,"jsonrpc":"2.0","result":{"tools":[{"description":"test tool","name":"test"},{"description":"Run an lldb command.","inputSchema":{"properties":{"arguments":{"type":"string"}},"type":"object"},"name":"lldb_command"}]}})json";
+
+ ASSERT_THAT_ERROR(Write(request), llvm::Succeeded());
+
+ llvm::Expected<std::string> response_str = Read();
+ ASSERT_THAT_EXPECTED(response_str, llvm::Succeeded());
+
+ llvm::Expected<json::Value> response_json = json::parse(*response_str);
+ ASSERT_THAT_EXPECTED(response_json, llvm::Succeeded());
+
+ llvm::Expected<json::Value> expected_json = json::parse(response);
+ ASSERT_THAT_EXPECTED(expected_json, llvm::Succeeded());
+
+ EXPECT_EQ(*response_json, *expected_json);
+}
+
+TEST_F(ProtocolServerMCPTest, ResourcesList) {
+ llvm::StringLiteral request =
+ R"json({"method":"resources/list","params":{},"jsonrpc":"2.0","id":2})json";
+ llvm::StringLiteral response =
+ R"json({"error":{"code":1,"message":"no handler for request: resources/list"},"id":2,"jsonrpc":"2.0"})json";
+
+ ASSERT_THAT_ERROR(Write(request), llvm::Succeeded());
+
+ llvm::Expected<std::string> response_str = Read();
+ ASSERT_THAT_EXPECTED(response_str, llvm::Succeeded());
+
+ llvm::Expected<json::Value> response_json = json::parse(*response_str);
+ ASSERT_THAT_EXPECTED(response_json, llvm::Succeeded());
+
+ llvm::Expected<json::Value> expected_json = json::parse(response);
+ ASSERT_THAT_EXPECTED(expected_json, llvm::Succeeded());
+
+ EXPECT_EQ(*response_json, *expected_json);
+}
+
+TEST_F(ProtocolServerMCPTest, ToolsCall) {
+ llvm::StringLiteral request =
+ R"json({"method":"tools/call","params":{"name":"test","arguments":{"arguments":"foo"}},"jsonrpc":"2.0","id":11})json";
+ llvm::StringLiteral response =
+ R"json({"id":11,"jsonrpc":"2.0","result":{"content":[{"text":"foo","type":"text"}],"isError":false}})json";
+
+ ASSERT_THAT_ERROR(Write(request), llvm::Succeeded());
+
+ llvm::Expected<std::string> response_str = Read();
+ ASSERT_THAT_EXPECTED(response_str, llvm::Succeeded());
+
+ llvm::Expected<json::Value> response_json = json::parse(*response_str);
+ ASSERT_THAT_EXPECTED(response_json, llvm::Succeeded());
+
+ llvm::Expected<json::Value> expected_json = json::parse(response);
+ ASSERT_THAT_EXPECTED(expected_json, llvm::Succeeded());
+
+ EXPECT_EQ(*response_json, *expected_json);
+}
+
+TEST_F(ProtocolServerMCPTest, ToolsCallError) {
+ m_server_up->AddTool(std::make_unique<ErrorTool>("error", "error tool"));
+
+ llvm::StringLiteral request =
+ R"json({"method":"tools/call","params":{"name":"error","arguments":{"arguments":"foo"}},"jsonrpc":"2.0","id":11})json";
+ llvm::StringLiteral response =
+ R"json({"error":{"code":-1,"message":"error"},"id":11,"jsonrpc":"2.0"})json";
+
+ ASSERT_THAT_ERROR(Write(request), llvm::Succeeded());
+
+ llvm::Expected<std::string> response_str = Read();
+ ASSERT_THAT_EXPECTED(response_str, llvm::Succeeded());
+
+ llvm::Expected<json::Value> response_json = json::parse(*response_str);
+ ASSERT_THAT_EXPECTED(response_json, llvm::Succeeded());
+
+ llvm::Expected<json::Value> expected_json = json::parse(response);
+ ASSERT_THAT_EXPECTED(expected_json, llvm::Succeeded());
+
+ EXPECT_EQ(*response_json, *expected_json);
+}
+
+TEST_F(ProtocolServerMCPTest, ToolsCallFail) {
+ m_server_up->AddTool(std::make_unique<FailTool>("fail", "fail tool"));
+
+ llvm::StringLiteral request =
+ R"json({"method":"tools/call","params":{"name":"fail","arguments":{"arguments":"foo"}},"jsonrpc":"2.0","id":11})json";
+ llvm::StringLiteral response =
+ R"json({"id":11,"jsonrpc":"2.0","result":{"content":[{"text":"failed","type":"text"}],"isError":true}})json";
+
+ ASSERT_THAT_ERROR(Write(request), llvm::Succeeded());
+
+ llvm::Expected<std::string> response_str = Read();
+ ASSERT_THAT_EXPECTED(response_str, llvm::Succeeded());
+
+ llvm::Expected<json::Value> response_json = json::parse(*response_str);
+ ASSERT_THAT_EXPECTED(response_json, llvm::Succeeded());
+
+ llvm::Expected<json::Value> expected_json = json::parse(response);
+ ASSERT_THAT_EXPECTED(expected_json, llvm::Succeeded());
+
+ EXPECT_EQ(*response_json, *expected_json);
+}
+
+TEST_F(ProtocolServerMCPTest, NotificationInitialized) {
+ bool handler_called = false;
+ std::condition_variable cv;
+ std::mutex mutex;
+
+ m_server_up->AddNotificationHandler(
+ "notifications/initialized",
+ [&](const mcp::protocol::Notification ¬ification) {
+ {
+ std::lock_guard<std::mutex> lock(mutex);
+ handler_called = true;
+ }
+ cv.notify_all();
+ });
+ llvm::StringLiteral request =
+ R"json({"method":"notifications/initialized","jsonrpc":"2.0"})json";
+
+ ASSERT_THAT_ERROR(Write(request), llvm::Succeeded());
+
+ std::unique_lock<std::mutex> lock(mutex);
+ cv.wait(lock, [&] { return handler_called; });
+}
diff --git a/lldb/unittests/Protocol/ProtocolMCPTest.cpp b/lldb/unittests/Protocol/ProtocolMCPTest.cpp
new file mode 100644
index 0000000000000..00959f3ce20be
--- /dev/null
+++ b/lldb/unittests/Protocol/ProtocolMCPTest.cpp
@@ -0,0 +1,135 @@
+//===-- ProtocolMCPTest.cpp -----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Plugins/Protocol/MCP/Protocol.h"
+#include "TestingSupport/TestUtilities.h"
+#include "llvm/Testing/Support/Error.h"
+#include "gtest/gtest.h"
+
+using namespace lldb;
+using namespace lldb_private;
+using namespace lldb_private::mcp::protocol;
+
+TEST(ProtocolMCPTest, Request) {
+ Request request;
+ request.id = 1;
+ request.method = "foo";
+ request.params = llvm::json::Object{{"key", "value"}};
+
+ llvm::Expected<Request> deserialized_request = roundtripJSON(request);
+ ASSERT_THAT_EXPECTED(deserialized_request, llvm::Succeeded());
+
+ EXPECT_EQ(request.id, deserialized_request->id);
+ EXPECT_EQ(request.method, deserialized_request->method);
+ EXPECT_EQ(request.params, deserialized_request->params);
+}
+
+TEST(ProtocolMCPTest, Response) {
+ Response response;
+ response.id = 1;
+ response.result = llvm::json::Object{{"key", "value"}};
+
+ llvm::Expected<Response> deserialized_response = roundtripJSON(response);
+ ASSERT_THAT_EXPECTED(deserialized_response, llvm::Succeeded());
+
+ EXPECT_EQ(response.id, deserialized_response->id);
+ EXPECT_EQ(response.result, deserialized_response->result);
+}
+
+TEST(ProtocolMCPTest, Notification) {
+ Notification notification;
+ notification.method = "notifyMethod";
+ notification.params = llvm::json::Object{{"key", "value"}};
+
+ llvm::Expected<Notification> deserialized_notification =
+ roundtripJSON(notification);
+ ASSERT_THAT_EXPECTED(deserialized_notification, llvm::Succeeded());
+
+ EXPECT_EQ(notification.method, deserialized_notification->method);
+ EXPECT_EQ(notification.params, deserialized_notification->params);
+}
+
+TEST(ProtocolMCPTest, ToolCapability) {
+ ToolCapability tool_capability;
+ tool_capability.listChanged = true;
+
+ llvm::Expected<ToolCapability> deserialized_tool_capability =
+ roundtripJSON(tool_capability);
+ ASSERT_THAT_EXPECTED(deserialized_tool_capability, llvm::Succeeded());
+
+ EXPECT_EQ(tool_capability.listChanged,
+ deserialized_tool_capability->listChanged);
+}
+
+TEST(ProtocolMCPTest, Capabilities) {
+ ToolCapability tool_capability;
+ tool_capability.listChanged = true;
+
+ Capabilities capabilities;
+ capabilities.tools = tool_capability;
+
+ llvm::Expected<Capabilities> deserialized_capabilities =
+ roundtripJSON(capabilities);
+ ASSERT_THAT_EXPECTED(deserialized_capabilities, llvm::Succeeded());
+
+ EXPECT_EQ(capabilities.tools.listChanged,
+ deserialized_capabilities->tools.listChanged);
+}
+
+TEST(ProtocolMCPTest, TextContent) {
+ TextContent text_content;
+ text_content.text = "Sample text";
+
+ llvm::Expected<TextContent> deserialized_text_content =
+ roundtripJSON(text_content);
+ ASSERT_THAT_EXPECTED(deserialized_text_content, llvm::Succeeded());
+
+ EXPECT_EQ(text_content.text, deserialized_text_content->text);
+}
+
+TEST(ProtocolMCPTest, TextResult) {
+ TextContent text_content1;
+ text_content1.text = "Text 1";
+
+ TextContent text_content2;
+ text_content2.text = "Text 2";
+
+ TextResult text_result;
+ text_result.content = {text_content1, text_content2};
+ text_result.isError = true;
+
+ llvm::Expected<TextResult> deserialized_text_result =
+ roundtripJSON(text_result);
+ ASSERT_THAT_EXPECTED(deserialized_text_result, llvm::Succeeded());
+
+ EXPECT_EQ(text_result.isError, deserialized_text_result->isError);
+ ASSERT_EQ(text_result.content.size(),
+ deserialized_text_result->content.size());
+ EXPECT_EQ(text_result.content[0].text,
+ deserialized_text_result->content[0].text);
+ EXPECT_EQ(text_result.content[1].text,
+ deserialized_text_result->content[1].text);
+}
+
+TEST(ProtocolMCPTest, ToolDefinition) {
+ ToolDefinition tool_definition;
+ tool_definition.name = "ToolName";
+ tool_definition.description = "Tool Description";
+ tool_definition.inputSchema =
+ llvm::json::Object{{"schemaKey", "schemaValue"}};
+
+ llvm::Expected<ToolDefinition> deserialized_tool_definition =
+ roundtripJSON(tool_definition);
+ ASSERT_THAT_EXPECTED(deserialized_tool_definition, llvm::Succeeded());
+
+ EXPECT_EQ(tool_definition.name, deserialized_tool_definition->name);
+ EXPECT_EQ(tool_definition.description,
+ deserialized_tool_definition->description);
+ EXPECT_EQ(tool_definition.inputSchema,
+ deserialized_tool_definition->inputSchema);
+}
diff --git a/lldb/unittests/TestingSupport/TestUtilities.h b/lldb/unittests/TestingSupport/TestUtilities.h
index 65994384059fb..db62881872fef 100644
--- a/lldb/unittests/TestingSupport/TestUtilities.h
+++ b/lldb/unittests/TestingSupport/TestUtilities.h
@@ -59,6 +59,15 @@ class TestFile {
std::string Buffer;
};
+
+template <typename T> static llvm::Expected<T> roundtripJSON(const T &input) {
+ llvm::json::Value value = toJSON(input);
+ llvm::json::Path::Root root;
+ T output;
+ if (!fromJSON(value, output, root))
+ return root.getError();
+ return output;
+}
} // namespace lldb_private
#endif
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