[Lldb-commits] [lldb] [lldb-mcp] Auto connect to the first running lldb mcp instance. (PR #157503)
John Harrison via lldb-commits
lldb-commits at lists.llvm.org
Tue Sep 9 09:47:39 PDT 2025
https://github.com/ashgti updated https://github.com/llvm/llvm-project/pull/157503
>From ec45d323014b15ce7a960fc519ef3782820a44d2 Mon Sep 17 00:00:00 2001
From: John Harrison <harjohn at google.com>
Date: Mon, 8 Sep 2025 09:05:15 -0700
Subject: [PATCH 1/2] [lldb-mcp] Auto connect to the first running lldb mcp
instance.
This improves the flow by automatically connecting to an exisitng lldb instance, if one is found.
Future improvements include:
* Launching a binary if an instance isn't detected.
* Multiplexing if multiple instances are detected.
---
lldb/include/lldb/Protocol/MCP/Server.h | 5 +
lldb/source/Protocol/MCP/Server.cpp | 78 +++++++++++++--
lldb/tools/lldb-mcp/CMakeLists.txt | 1 +
lldb/tools/lldb-mcp/lldb-mcp.cpp | 125 ++++++++++++++++++++----
4 files changed, 184 insertions(+), 25 deletions(-)
diff --git a/lldb/include/lldb/Protocol/MCP/Server.h b/lldb/include/lldb/Protocol/MCP/Server.h
index 254b7d9680cd8..a65c310828daf 100644
--- a/lldb/include/lldb/Protocol/MCP/Server.h
+++ b/lldb/include/lldb/Protocol/MCP/Server.h
@@ -30,6 +30,11 @@ namespace lldb_protocol::mcp {
struct ServerInfo {
std::string connection_uri;
lldb::pid_t pid;
+
+ /// Writes the server info into a unique file in `~/.lldb`.
+ static llvm::Error Write(const ServerInfo &);
+ /// Loads any server info saved in `~/.lldb`.
+ static llvm::Expected<std::vector<ServerInfo>> Load();
};
llvm::json::Value toJSON(const ServerInfo &);
bool fromJSON(const llvm::json::Value &, ServerInfo &, llvm::json::Path);
diff --git a/lldb/source/Protocol/MCP/Server.cpp b/lldb/source/Protocol/MCP/Server.cpp
index 0381b7f745e98..3c2c246218774 100644
--- a/lldb/source/Protocol/MCP/Server.cpp
+++ b/lldb/source/Protocol/MCP/Server.cpp
@@ -7,25 +7,89 @@
//===----------------------------------------------------------------------===//
#include "lldb/Protocol/MCP/Server.h"
+#include "lldb/Host/File.h"
+#include "lldb/Host/FileSystem.h"
+#include "lldb/Host/HostInfo.h"
+#include "lldb/Host/JSONTransport.h"
#include "lldb/Protocol/MCP/MCPError.h"
#include "lldb/Protocol/MCP/Protocol.h"
#include "llvm/Support/JSON.h"
-using namespace lldb_protocol::mcp;
using namespace llvm;
+using namespace lldb_private;
+using namespace lldb_protocol::mcp;
-llvm::json::Value lldb_protocol::mcp::toJSON(const ServerInfo &SM) {
- return llvm::json::Object{{"connection_uri", SM.connection_uri},
- {"pid", SM.pid}};
+json::Value lldb_protocol::mcp::toJSON(const ServerInfo &SM) {
+ return json::Object{{"connection_uri", SM.connection_uri}, {"pid", SM.pid}};
}
-bool lldb_protocol::mcp::fromJSON(const llvm::json::Value &V, ServerInfo &SM,
- llvm::json::Path P) {
- llvm::json::ObjectMapper O(V, P);
+bool lldb_protocol::mcp::fromJSON(const json::Value &V, ServerInfo &SM,
+ json::Path P) {
+ json::ObjectMapper O(V, P);
return O && O.map("connection_uri", SM.connection_uri) &&
O.map("pid", SM.pid);
}
+llvm::Error ServerInfo::Write(const ServerInfo &info) {
+ std::string buf = formatv("{0}", toJSON(info)).str();
+ size_t num_bytes = buf.size();
+
+ FileSpec user_lldb_dir = HostInfo::GetUserLLDBDir();
+
+ Status error(llvm::sys::fs::create_directory(user_lldb_dir.GetPath()));
+ if (error.Fail())
+ return error.takeError();
+
+ FileSpec mcp_registry_entry_path = user_lldb_dir.CopyByAppendingPathComponent(
+ formatv("lldb-mcp-{0}.json", getpid()).str());
+
+ const File::OpenOptions flags = File::eOpenOptionWriteOnly |
+ File::eOpenOptionCanCreate |
+ File::eOpenOptionTruncate;
+ llvm::Expected<lldb::FileUP> file = FileSystem::Instance().Open(
+ mcp_registry_entry_path, flags, lldb::eFilePermissionsFileDefault, false);
+ if (!file)
+ return file.takeError();
+ if (llvm::Error error = (*file)->Write(buf.data(), num_bytes).takeError())
+ return error;
+ return llvm::Error::success();
+}
+
+llvm::Expected<std::vector<ServerInfo>> ServerInfo::Load() {
+ FileSpec user_lldb_dir = HostInfo::GetUserLLDBDir();
+ namespace path = llvm::sys::path;
+ FileSystem &fs = FileSystem::Instance();
+ std::error_code EC;
+ llvm::vfs::directory_iterator it = fs.DirBegin(user_lldb_dir, EC);
+ llvm::vfs::directory_iterator end;
+ std::vector<ServerInfo> infos;
+ for (; it != end && !EC; it.increment(EC)) {
+ auto &entry = *it;
+ auto name = path::filename(entry.path());
+ if (!name.starts_with("lldb-mcp-") || !name.ends_with(".json")) {
+ continue;
+ }
+
+ llvm::Expected<std::unique_ptr<File>> file =
+ fs.Open(FileSpec(entry.path()), File::eOpenOptionReadOnly);
+ if (!file)
+ return file.takeError();
+
+ char buf[1024] = {0};
+ size_t bytes_read = sizeof(buf);
+ if (llvm::Error error = (*file)->Read(buf, bytes_read).takeError())
+ return std::move(error);
+
+ auto info = json::parse<ServerInfo>(StringRef(buf, bytes_read));
+ if (!info)
+ return info.takeError();
+
+ infos.emplace_back(std::move(*info));
+ }
+
+ return infos;
+}
+
Server::Server(std::string name, std::string version,
std::unique_ptr<MCPTransport> transport_up,
lldb_private::MainLoop &loop)
diff --git a/lldb/tools/lldb-mcp/CMakeLists.txt b/lldb/tools/lldb-mcp/CMakeLists.txt
index 7fe3301ab3081..5f61a1993cea3 100644
--- a/lldb/tools/lldb-mcp/CMakeLists.txt
+++ b/lldb/tools/lldb-mcp/CMakeLists.txt
@@ -6,6 +6,7 @@ add_lldb_tool(lldb-mcp
Support
LINK_LIBS
liblldb
+ lldbInitialization
lldbHost
lldbProtocolMCP
)
diff --git a/lldb/tools/lldb-mcp/lldb-mcp.cpp b/lldb/tools/lldb-mcp/lldb-mcp.cpp
index 6c4ebbaa5f230..498eaaaa8f383 100644
--- a/lldb/tools/lldb-mcp/lldb-mcp.cpp
+++ b/lldb/tools/lldb-mcp/lldb-mcp.cpp
@@ -10,17 +10,28 @@
#include "lldb/Host/File.h"
#include "lldb/Host/MainLoop.h"
#include "lldb/Host/MainLoopBase.h"
-#include "lldb/Protocol/MCP/Protocol.h"
+#include "lldb/Host/Socket.h"
+#include "lldb/Initialization/SystemInitializerCommon.h"
+#include "lldb/Initialization/SystemLifetimeManager.h"
#include "lldb/Protocol/MCP/Server.h"
+#include "lldb/Utility/Status.h"
+#include "lldb/Utility/UriParser.h"
+#include "lldb/lldb-forward.h"
#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Error.h"
#include "llvm/Support/InitLLVM.h"
+#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/WithColor.h"
+#include <cstdlib>
+#include <memory>
#if defined(_WIN32)
#include <fcntl.h>
#endif
+using namespace llvm;
+using namespace lldb;
using namespace lldb_protocol::mcp;
using lldb_private::File;
@@ -28,8 +39,78 @@ using lldb_private::MainLoop;
using lldb_private::MainLoopBase;
using lldb_private::NativeFile;
-static constexpr llvm::StringLiteral kName = "lldb-mcp";
-static constexpr llvm::StringLiteral kVersion = "0.1.0";
+namespace {
+
+inline void error(llvm::Error Err, StringRef Prefix = "") {
+ handleAllErrors(std::move(Err), [&](ErrorInfoBase &Info) {
+ WithColor::error(errs(), Prefix) << Info.message() << '\n';
+ });
+ std::exit(EXIT_FAILURE);
+}
+
+constexpr size_t kForwardIOBufferSize = 1024;
+
+void forwardIO(lldb_private::MainLoopBase &loop, lldb::IOObjectSP &from,
+ lldb::IOObjectSP &to) {
+ char buf[kForwardIOBufferSize];
+ size_t num_bytes = sizeof(buf);
+
+ if (llvm::Error err = from->Read(buf, num_bytes).takeError())
+ error(std::move(err));
+
+ // EOF reached.
+ if (num_bytes == 0)
+ return loop.RequestTermination();
+
+ if (llvm::Error err = to->Write(buf, num_bytes).takeError())
+ error(std::move(err));
+}
+
+void connectAndForwardIO(lldb_private::MainLoop &loop, ServerInfo &info,
+ IOObjectSP &input_sp, IOObjectSP &output_sp) {
+ auto uri = lldb_private::URI::Parse(info.connection_uri);
+ if (!uri)
+ error(createStringError("invalid connection_uri"));
+
+ std::optional<lldb_private::Socket::ProtocolModePair> protocol_and_mode =
+ lldb_private::Socket::GetProtocolAndMode(uri->scheme);
+
+ lldb_private::Status status;
+ std::unique_ptr<lldb_private::Socket> sock =
+ lldb_private::Socket::Create(protocol_and_mode->first, status);
+
+ if (status.Fail())
+ error(status.takeError());
+
+ if (uri->port && !uri->hostname.empty())
+ status = sock->Connect(
+ llvm::formatv("[{0}]:{1}", uri->hostname, *uri->port).str());
+ else
+ status = sock->Connect(uri->path);
+ if (status.Fail())
+ error(status.takeError());
+
+ IOObjectSP sock_sp = std::move(sock);
+ auto input_handle = loop.RegisterReadObject(
+ input_sp, std::bind(forwardIO, std::placeholders::_1, input_sp, sock_sp),
+ status);
+ if (status.Fail())
+ error(status.takeError());
+
+ auto socket_handle = loop.RegisterReadObject(
+ sock_sp, std::bind(forwardIO, std::placeholders::_1, sock_sp, output_sp),
+ status);
+ if (status.Fail())
+ error(status.takeError());
+
+ status = loop.Run();
+ if (status.Fail())
+ error(status.takeError());
+}
+
+llvm::ManagedStatic<lldb_private::SystemLifetimeManager> g_debugger_lifetime;
+
+} // namespace
int main(int argc, char *argv[]) {
llvm::InitLLVM IL(argc, argv, /*InstallPipeSignalExitHandler=*/false);
@@ -53,33 +134,41 @@ int main(int argc, char *argv[]) {
assert(result);
#endif
- lldb::IOObjectSP input = std::make_shared<NativeFile>(
+ if (auto e = g_debugger_lifetime->Initialize(
+ std::make_unique<lldb_private::SystemInitializerCommon>(nullptr)))
+ error(std::move(e));
+
+ IOObjectSP input_sp = std::make_shared<NativeFile>(
fileno(stdin), File::eOpenOptionReadOnly, NativeFile::Unowned);
- lldb::IOObjectSP output = std::make_shared<NativeFile>(
+ IOObjectSP output_sp = std::make_shared<NativeFile>(
fileno(stdout), File::eOpenOptionWriteOnly, NativeFile::Unowned);
- constexpr llvm::StringLiteral client_name = "stdio";
static MainLoop loop;
- llvm::sys::SetInterruptFunction([]() {
+ sys::SetInterruptFunction([]() {
loop.AddPendingCallback(
[](MainLoopBase &loop) { loop.RequestTermination(); });
});
- auto transport_up = std::make_unique<lldb_protocol::mcp::Transport>(
- input, output, [&](llvm::StringRef message) {
- llvm::errs() << formatv("{0}: {1}", client_name, message) << '\n';
- });
+ auto existing_servers = ServerInfo::Load();
+
+ if (!existing_servers)
+ error(existing_servers.takeError());
+
+ // FIXME: Launch `lldb -o 'protocol start MCP'`.
+ if (existing_servers->empty())
+ error(createStringError("No MCP servers running"));
+
+ // FIXME: Support selecting a specific server.
+ if (existing_servers->size() != 1)
+ error(createStringError("To many MCP servers running, picking a specific "
+ "one is not yet implemented."));
- auto instance_up = std::make_unique<lldb_protocol::mcp::Server>(
- std::string(kName), std::string(kVersion), std::move(transport_up), loop);
+ ServerInfo &info = existing_servers->front();
+ connectAndForwardIO(loop, info, input_sp, output_sp);
- if (llvm::Error error = instance_up->Run()) {
- llvm::logAllUnhandledErrors(std::move(error), llvm::WithColor::error(),
- "MCP error: ");
- return EXIT_FAILURE;
- }
+ g_debugger_lifetime->Terminate();
return EXIT_SUCCESS;
}
>From a2c1a72975b97fb113ce81ca4c1be3e7b6b56e77 Mon Sep 17 00:00:00 2001
From: John Harrison <harjohn at google.com>
Date: Tue, 9 Sep 2025 09:46:53 -0700
Subject: [PATCH 2/2] Creating a handle to the written server info to ensure we
cleanup the file correctly and applying reviewer feedback.
---
lldb/include/lldb/Protocol/MCP/Server.h | 53 ++++++++++----
.../Protocol/MCP/ProtocolServerMCP.cpp | 39 +++-------
.../Plugins/Protocol/MCP/ProtocolServerMCP.h | 2 +-
lldb/source/Protocol/MCP/Server.cpp | 73 ++++++++++++-------
lldb/tools/lldb-mcp/lldb-mcp.cpp | 36 ++++-----
5 files changed, 115 insertions(+), 88 deletions(-)
diff --git a/lldb/include/lldb/Protocol/MCP/Server.h b/lldb/include/lldb/Protocol/MCP/Server.h
index a65c310828daf..b674d58159550 100644
--- a/lldb/include/lldb/Protocol/MCP/Server.h
+++ b/lldb/include/lldb/Protocol/MCP/Server.h
@@ -15,9 +15,12 @@
#include "lldb/Protocol/MCP/Resource.h"
#include "lldb/Protocol/MCP/Tool.h"
#include "lldb/Protocol/MCP/Transport.h"
+#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/JSON.h"
+#include "llvm/Support/Signals.h"
#include <functional>
#include <memory>
#include <string>
@@ -25,20 +28,6 @@
namespace lldb_protocol::mcp {
-/// Information about this instance of lldb's MCP server for lldb-mcp to use to
-/// coordinate connecting an lldb-mcp client.
-struct ServerInfo {
- std::string connection_uri;
- lldb::pid_t pid;
-
- /// Writes the server info into a unique file in `~/.lldb`.
- static llvm::Error Write(const ServerInfo &);
- /// Loads any server info saved in `~/.lldb`.
- static llvm::Expected<std::vector<ServerInfo>> Load();
-};
-llvm::json::Value toJSON(const ServerInfo &);
-bool fromJSON(const llvm::json::Value &, ServerInfo &, llvm::json::Path);
-
class Server : public MCPTransport::MessageHandler {
public:
Server(std::string name, std::string version,
@@ -100,6 +89,42 @@ class Server : public MCPTransport::MessageHandler {
llvm::StringMap<NotificationHandler> m_notification_handlers;
};
+class ServerInfoHandle;
+
+/// Information about this instance of lldb's MCP server for lldb-mcp to use to
+/// coordinate connecting an lldb-mcp client.
+struct ServerInfo {
+ std::string connection_uri;
+
+ /// Writes the server info into a unique file in `~/.lldb`.
+ static llvm::Expected<ServerInfoHandle> Write(const ServerInfo &);
+ /// Loads any server info saved in `~/.lldb`.
+ static llvm::Expected<std::vector<ServerInfo>> Load();
+};
+llvm::json::Value toJSON(const ServerInfo &);
+bool fromJSON(const llvm::json::Value &, ServerInfo &, llvm::json::Path);
+
+/// A handle that tracks the server info on disk and cleans up the disk record
+/// once it is no longer referenced.
+class ServerInfoHandle {
+public:
+ ServerInfoHandle();
+ explicit ServerInfoHandle(llvm::StringRef filename);
+ ~ServerInfoHandle();
+
+ ServerInfoHandle(ServerInfoHandle &&other);
+ ServerInfoHandle &operator=(ServerInfoHandle &&other) noexcept;
+
+ /// ServerIinfoHandle is not copyable.
+ /// @{
+ ServerInfoHandle(const ServerInfoHandle &) = delete;
+ ServerInfoHandle &operator=(const ServerInfoHandle &) = delete;
+ /// @}
+
+private:
+ llvm::SmallString<128> m_filename;
+};
+
} // namespace lldb_protocol::mcp
#endif
diff --git a/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.cpp b/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.cpp
index 2b004c19e88a6..dc18c8e06803a 100644
--- a/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.cpp
+++ b/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.cpp
@@ -113,34 +113,13 @@ llvm::Error ProtocolServerMCP::Start(ProtocolServer::Connection connection) {
std::string address =
llvm::join(m_listener->GetListeningConnectionURI(), ", ");
- FileSpec user_lldb_dir = HostInfo::GetUserLLDBDir();
-
- Status error(llvm::sys::fs::create_directory(user_lldb_dir.GetPath()));
- if (error.Fail())
- return error.takeError();
-
- m_mcp_registry_entry_path = user_lldb_dir.CopyByAppendingPathComponent(
- formatv("lldb-mcp-{0}.json", getpid()).str());
-
- ServerInfo info;
- info.connection_uri = listening_uris[0];
- info.pid = getpid();
-
- std::string buf = formatv("{0}", toJSON(info)).str();
- size_t num_bytes = buf.size();
-
- const File::OpenOptions flags = File::eOpenOptionWriteOnly |
- File::eOpenOptionCanCreate |
- File::eOpenOptionTruncate;
- llvm::Expected<lldb::FileUP> file =
- FileSystem::Instance().Open(m_mcp_registry_entry_path, flags,
- lldb::eFilePermissionsFileDefault, false);
- if (!file)
- return file.takeError();
- if (llvm::Error error = (*file)->Write(buf.data(), num_bytes).takeError())
- return error;
+ ServerInfo info{listening_uris[0]};
+ llvm::Expected<ServerInfoHandle> handle = ServerInfo::Write(info);
+ if (!handle)
+ return handle.takeError();
m_running = true;
+ m_server_info_handle = std::move(*handle);
m_listen_handlers = std::move(*handles);
m_loop_thread = std::thread([=] {
llvm::set_thread_name("protocol-server.mcp");
@@ -158,10 +137,6 @@ llvm::Error ProtocolServerMCP::Stop() {
m_running = false;
}
- if (!m_mcp_registry_entry_path.GetPath().empty())
- FileSystem::Instance().RemoveFile(m_mcp_registry_entry_path);
- m_mcp_registry_entry_path.Clear();
-
// Stop the main loop.
m_loop.AddPendingCallback(
[](lldb_private::MainLoopBase &loop) { loop.RequestTermination(); });
@@ -170,5 +145,9 @@ llvm::Error ProtocolServerMCP::Stop() {
if (m_loop_thread.joinable())
m_loop_thread.join();
+ m_listen_handlers.clear();
+ m_server_info_handle = ServerInfoHandle();
+ m_instances.clear();
+
return llvm::Error::success();
}
diff --git a/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.h b/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.h
index 004fa3c2d05a8..0251664a2acc4 100644
--- a/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.h
+++ b/lldb/source/Plugins/Protocol/MCP/ProtocolServerMCP.h
@@ -48,7 +48,7 @@ class ProtocolServerMCP : public ProtocolServer {
bool m_running = false;
- FileSpec m_mcp_registry_entry_path;
+ lldb_protocol::mcp::ServerInfoHandle m_server_info_handle;
lldb_private::MainLoop m_loop;
std::thread m_loop_thread;
std::mutex m_mutex;
diff --git a/lldb/source/Protocol/MCP/Server.cpp b/lldb/source/Protocol/MCP/Server.cpp
index 3c2c246218774..f3489c620832f 100644
--- a/lldb/source/Protocol/MCP/Server.cpp
+++ b/lldb/source/Protocol/MCP/Server.cpp
@@ -13,30 +13,60 @@
#include "lldb/Host/JSONTransport.h"
#include "lldb/Protocol/MCP/MCPError.h"
#include "lldb/Protocol/MCP/Protocol.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/FileSystem.h"
#include "llvm/Support/JSON.h"
+#include "llvm/Support/Signals.h"
using namespace llvm;
using namespace lldb_private;
using namespace lldb_protocol::mcp;
+ServerInfoHandle::ServerInfoHandle() : ServerInfoHandle("") {}
+
+ServerInfoHandle::ServerInfoHandle(StringRef filename) : m_filename(filename) {
+ if (!m_filename.empty())
+ sys::RemoveFileOnSignal(m_filename);
+}
+
+ServerInfoHandle::~ServerInfoHandle() {
+ if (m_filename.empty())
+ return;
+
+ sys::fs::remove(m_filename);
+ sys::DontRemoveFileOnSignal(m_filename);
+ m_filename.clear();
+}
+
+ServerInfoHandle::ServerInfoHandle(ServerInfoHandle &&other)
+ : m_filename(other.m_filename) {
+ *this = std::move(other);
+}
+
+ServerInfoHandle &
+ServerInfoHandle::operator=(ServerInfoHandle &&other) noexcept {
+ m_filename = other.m_filename;
+ other.m_filename.clear();
+ return *this;
+}
+
json::Value lldb_protocol::mcp::toJSON(const ServerInfo &SM) {
- return json::Object{{"connection_uri", SM.connection_uri}, {"pid", SM.pid}};
+ return json::Object{{"connection_uri", SM.connection_uri}};
}
bool lldb_protocol::mcp::fromJSON(const json::Value &V, ServerInfo &SM,
json::Path P) {
json::ObjectMapper O(V, P);
- return O && O.map("connection_uri", SM.connection_uri) &&
- O.map("pid", SM.pid);
+ return O && O.map("connection_uri", SM.connection_uri);
}
-llvm::Error ServerInfo::Write(const ServerInfo &info) {
+Expected<ServerInfoHandle> ServerInfo::Write(const ServerInfo &info) {
std::string buf = formatv("{0}", toJSON(info)).str();
size_t num_bytes = buf.size();
FileSpec user_lldb_dir = HostInfo::GetUserLLDBDir();
- Status error(llvm::sys::fs::create_directory(user_lldb_dir.GetPath()));
+ Status error(sys::fs::create_directory(user_lldb_dir.GetPath()));
if (error.Fail())
return error.takeError();
@@ -46,41 +76,32 @@ llvm::Error ServerInfo::Write(const ServerInfo &info) {
const File::OpenOptions flags = File::eOpenOptionWriteOnly |
File::eOpenOptionCanCreate |
File::eOpenOptionTruncate;
- llvm::Expected<lldb::FileUP> file = FileSystem::Instance().Open(
- mcp_registry_entry_path, flags, lldb::eFilePermissionsFileDefault, false);
+ Expected<lldb::FileUP> file =
+ FileSystem::Instance().Open(mcp_registry_entry_path, flags);
if (!file)
return file.takeError();
if (llvm::Error error = (*file)->Write(buf.data(), num_bytes).takeError())
return error;
- return llvm::Error::success();
+ return ServerInfoHandle{mcp_registry_entry_path.GetPath()};
}
-llvm::Expected<std::vector<ServerInfo>> ServerInfo::Load() {
- FileSpec user_lldb_dir = HostInfo::GetUserLLDBDir();
+Expected<std::vector<ServerInfo>> ServerInfo::Load() {
namespace path = llvm::sys::path;
+ FileSpec user_lldb_dir = HostInfo::GetUserLLDBDir();
FileSystem &fs = FileSystem::Instance();
std::error_code EC;
- llvm::vfs::directory_iterator it = fs.DirBegin(user_lldb_dir, EC);
- llvm::vfs::directory_iterator end;
+ vfs::directory_iterator it = fs.DirBegin(user_lldb_dir, EC);
+ vfs::directory_iterator end;
std::vector<ServerInfo> infos;
for (; it != end && !EC; it.increment(EC)) {
auto &entry = *it;
- auto name = path::filename(entry.path());
- if (!name.starts_with("lldb-mcp-") || !name.ends_with(".json")) {
+ auto path = entry.path();
+ auto name = path::filename(path);
+ if (!name.starts_with("lldb-mcp-") || !name.ends_with(".json"))
continue;
- }
-
- llvm::Expected<std::unique_ptr<File>> file =
- fs.Open(FileSpec(entry.path()), File::eOpenOptionReadOnly);
- if (!file)
- return file.takeError();
-
- char buf[1024] = {0};
- size_t bytes_read = sizeof(buf);
- if (llvm::Error error = (*file)->Read(buf, bytes_read).takeError())
- return std::move(error);
- auto info = json::parse<ServerInfo>(StringRef(buf, bytes_read));
+ auto buffer = fs.CreateDataBuffer(path);
+ auto info = json::parse<ServerInfo>(toStringRef(buffer->GetData()));
if (!info)
return info.takeError();
diff --git a/lldb/tools/lldb-mcp/lldb-mcp.cpp b/lldb/tools/lldb-mcp/lldb-mcp.cpp
index 498eaaaa8f383..12545dcf3a3cc 100644
--- a/lldb/tools/lldb-mcp/lldb-mcp.cpp
+++ b/lldb/tools/lldb-mcp/lldb-mcp.cpp
@@ -17,6 +17,7 @@
#include "lldb/Utility/Status.h"
#include "lldb/Utility/UriParser.h"
#include "lldb/lldb-forward.h"
+#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/InitLLVM.h"
@@ -41,7 +42,7 @@ using lldb_private::NativeFile;
namespace {
-inline void error(llvm::Error Err, StringRef Prefix = "") {
+inline void exitWithError(llvm::Error Err, StringRef Prefix = "") {
handleAllErrors(std::move(Err), [&](ErrorInfoBase &Info) {
WithColor::error(errs(), Prefix) << Info.message() << '\n';
});
@@ -56,21 +57,21 @@ void forwardIO(lldb_private::MainLoopBase &loop, lldb::IOObjectSP &from,
size_t num_bytes = sizeof(buf);
if (llvm::Error err = from->Read(buf, num_bytes).takeError())
- error(std::move(err));
+ exitWithError(std::move(err));
// EOF reached.
if (num_bytes == 0)
return loop.RequestTermination();
if (llvm::Error err = to->Write(buf, num_bytes).takeError())
- error(std::move(err));
+ exitWithError(std::move(err));
}
void connectAndForwardIO(lldb_private::MainLoop &loop, ServerInfo &info,
IOObjectSP &input_sp, IOObjectSP &output_sp) {
auto uri = lldb_private::URI::Parse(info.connection_uri);
if (!uri)
- error(createStringError("invalid connection_uri"));
+ exitWithError(createStringError("invalid connection_uri"));
std::optional<lldb_private::Socket::ProtocolModePair> protocol_and_mode =
lldb_private::Socket::GetProtocolAndMode(uri->scheme);
@@ -80,7 +81,7 @@ void connectAndForwardIO(lldb_private::MainLoop &loop, ServerInfo &info,
lldb_private::Socket::Create(protocol_and_mode->first, status);
if (status.Fail())
- error(status.takeError());
+ exitWithError(status.takeError());
if (uri->port && !uri->hostname.empty())
status = sock->Connect(
@@ -88,24 +89,24 @@ void connectAndForwardIO(lldb_private::MainLoop &loop, ServerInfo &info,
else
status = sock->Connect(uri->path);
if (status.Fail())
- error(status.takeError());
+ exitWithError(status.takeError());
IOObjectSP sock_sp = std::move(sock);
auto input_handle = loop.RegisterReadObject(
input_sp, std::bind(forwardIO, std::placeholders::_1, input_sp, sock_sp),
status);
if (status.Fail())
- error(status.takeError());
+ exitWithError(status.takeError());
auto socket_handle = loop.RegisterReadObject(
sock_sp, std::bind(forwardIO, std::placeholders::_1, sock_sp, output_sp),
status);
if (status.Fail())
- error(status.takeError());
+ exitWithError(status.takeError());
status = loop.Run();
if (status.Fail())
- error(status.takeError());
+ exitWithError(status.takeError());
}
llvm::ManagedStatic<lldb_private::SystemLifetimeManager> g_debugger_lifetime;
@@ -134,9 +135,11 @@ int main(int argc, char *argv[]) {
assert(result);
#endif
- if (auto e = g_debugger_lifetime->Initialize(
+ if (llvm::Error err = g_debugger_lifetime->Initialize(
std::make_unique<lldb_private::SystemInitializerCommon>(nullptr)))
- error(std::move(e));
+ exitWithError(std::move(err));
+
+ auto cleanup = make_scope_exit([] { g_debugger_lifetime->Terminate(); });
IOObjectSP input_sp = std::make_shared<NativeFile>(
fileno(stdin), File::eOpenOptionReadOnly, NativeFile::Unowned);
@@ -154,21 +157,20 @@ int main(int argc, char *argv[]) {
auto existing_servers = ServerInfo::Load();
if (!existing_servers)
- error(existing_servers.takeError());
+ exitWithError(existing_servers.takeError());
// FIXME: Launch `lldb -o 'protocol start MCP'`.
if (existing_servers->empty())
- error(createStringError("No MCP servers running"));
+ exitWithError(createStringError("No MCP servers running"));
// FIXME: Support selecting a specific server.
if (existing_servers->size() != 1)
- error(createStringError("To many MCP servers running, picking a specific "
- "one is not yet implemented."));
+ exitWithError(
+ createStringError("To many MCP servers running, picking a specific "
+ "one is not yet implemented."));
ServerInfo &info = existing_servers->front();
connectAndForwardIO(loop, info, input_sp, output_sp);
- g_debugger_lifetime->Terminate();
-
return EXIT_SUCCESS;
}
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