CPP Languager Server support (clang)

.gitignore

@@ -403,7 +403,8 @@ src/multilspy/language_servers/omnisharp/static/
 src/multilspy/language_servers/rust_analyzer/static/
 src/multilspy/language_servers/typescript_language_server/static/
 src/multilspy/language_servers/dart_language_server/static/
+src/multilspy/language_servers/clangd_language_server/static/
 
 # Virtual Environment
 .venv/
-venv/
+venv/

src/multilspy/language_server.py

@@ -118,6 +118,10 @@ def create(cls, config: MultilspyConfig, logger: MultilspyLogger, repository_roo
             from multilspy.language_servers.dart_language_server.dart_language_server import DartLanguageServer
 
             return DartLanguageServer(config, logger, repository_root_path)
+        elif config.code_language == Language.CPP:
+            from multilspy.language_servers.clangd_language_server.clangd_language_server import ClangdLanguageServer
+
+            return ClangdLanguageServer(config, logger, repository_root_path)
         else:
             logger.log(f"Language {config.code_language} is not supported", logging.ERROR)
             raise MultilspyException(f"Language {config.code_language} is not supported")

src/multilspy/language_servers/clangd_language_server/clangd_language_server.py

@@ -0,0 +1,180 @@
+"""
+Provides C/C++ specific instantiation of the LanguageServer class. Contains various configurations and settings specific to C/C++.
+"""
+
+import asyncio
+import json
+import logging
+import os
+import stat
+import pathlib
+from contextlib import asynccontextmanager
+from typing import AsyncIterator
+
+from multilspy.multilspy_logger import MultilspyLogger
+from multilspy.language_server import LanguageServer
+from multilspy.lsp_protocol_handler.server import ProcessLaunchInfo
+from multilspy.lsp_protocol_handler.lsp_types import InitializeParams
+from multilspy.multilspy_config import MultilspyConfig
+from multilspy.multilspy_utils import FileUtils
+from multilspy.multilspy_utils import PlatformUtils
+
+
+class ClangdLanguageServer(LanguageServer):
+    """
+    Provides C/C++ specific instantiation of the LanguageServer class. Contains various configurations and settings specific to C/C++.
+    As the project gets bigger in size, building index will take time. Try running clangd multiple times to ensure index is built properly.
+    Also make sure compile_commands.json is created at root of the source directory. Check clangd test case for example.
+    """
+
+    def __init__(self, config: MultilspyConfig, logger: MultilspyLogger, repository_root_path: str):
+        """
+        Creates a ClangdLanguageServer instance. This class is not meant to be instantiated directly. Use LanguageServer.create() instead.
+        """
+        clangd_executable_path = self.setup_runtime_dependencies(logger, config)
+        super().__init__(
+            config,
+            logger,
+            repository_root_path,
+            ProcessLaunchInfo(cmd=clangd_executable_path, cwd=repository_root_path),
+            "cpp",
+        )
+        self.server_ready = asyncio.Event()
+
+    def setup_runtime_dependencies(self, logger: MultilspyLogger, config: MultilspyConfig) -> str:
+        """
+        Setup runtime dependencies for ClangdLanguageServer.
+        """
+        platform_id = PlatformUtils.get_platform_id()
+
+        with open(os.path.join(os.path.dirname(__file__), "runtime_dependencies.json"), "r") as f:
+            d = json.load(f)
+            del d["_description"]
+
+        assert platform_id.value in [
+            "linux-x64"
+        ], "Only linux-x64 is supported for in multilspy at the moment"
+
+        runtime_dependencies = d["runtimeDependencies"]
+        runtime_dependencies = [
+            dependency for dependency in runtime_dependencies if dependency["platformId"] == platform_id.value
+        ]
+        assert len(runtime_dependencies) == 1
+        dependency = runtime_dependencies[0]
+
+        clangd_ls_dir = os.path.join(os.path.dirname(__file__), "static/clangd")
+        clangd_executable_path = os.path.join(clangd_ls_dir, "clangd_19.1.2", "bin", dependency["binaryName"])
+        if not os.path.exists(clangd_ls_dir):
+            os.makedirs(clangd_ls_dir)
+            if dependency["archiveType"] == "zip":
+                FileUtils.download_and_extract_archive(
+                    logger, dependency["url"], clangd_ls_dir, dependency["archiveType"]
+                )
+        assert os.path.exists(clangd_executable_path)
+        os.chmod(clangd_executable_path, stat.S_IEXEC)
+
+        return clangd_executable_path
+
+    def _get_initialize_params(self, repository_absolute_path: str) -> InitializeParams:
+        """
+        Returns the initialize params for the clangd Language Server.
+        """
+        with open(os.path.join(os.path.dirname(__file__), "initialize_params.json"), "r") as f:
+            d = json.load(f)
+
+        del d["_description"]
+
+        d["processId"] = os.getpid()
+        assert d["rootPath"] == "$rootPath"
+        d["rootPath"] = repository_absolute_path
+
+        assert d["rootUri"] == "$rootUri"
+        d["rootUri"] = pathlib.Path(repository_absolute_path).as_uri()
+
+        assert d["workspaceFolders"][0]["uri"] == "$uri"
+        d["workspaceFolders"][0]["uri"] = pathlib.Path(repository_absolute_path).as_uri()
+
+        assert d["workspaceFolders"][0]["name"] == "$name"
+        d["workspaceFolders"][0]["name"] = os.path.basename(repository_absolute_path)
+
+        return d
+
+    @asynccontextmanager
+    async def start_server(self) -> AsyncIterator["ClangdLanguageServer"]:
+        """
+        Starts the Clangd Language Server, waits for the server to be ready and yields the LanguageServer instance.
+
+        Usage:
+        ```
+        async with lsp.start_server():
+            # LanguageServer has been initialized and ready to serve requests
+            await lsp.request_definition(...)
+            await lsp.request_references(...)
+            # Shutdown the LanguageServer on exit from scope
+        # LanguageServer has been shutdown
+        """
+        async def register_capability_handler(params):
+            assert "registrations" in params
+            for registration in params["registrations"]:
+                if registration["method"] == "workspace/executeCommand":
+                    self.initialize_searcher_command_available.set()
+                    self.resolve_main_method_available.set()
+            return
+
+        async def lang_status_handler(params):
+            # TODO: Should we wait for
+            # server -> client: {'jsonrpc': '2.0', 'method': 'language/status', 'params': {'type': 'ProjectStatus', 'message': 'OK'}}
+            # Before proceeding?
+            if params["type"] == "ServiceReady" and params["message"] == "ServiceReady":
+                self.service_ready_event.set()
+
+        async def execute_client_command_handler(params):
+            return []
+
+        async def do_nothing(params):
+            return
+
+        async def check_experimental_status(params):
+            if params["quiescent"] == True:
+                self.server_ready.set()
+
+        async def window_log_message(msg):
+            self.logger.log(f"LSP: window/logMessage: {msg}", logging.INFO)
+
+        self.server.on_request("client/registerCapability", register_capability_handler)
+        self.server.on_notification("language/status", lang_status_handler)
+        self.server.on_notification("window/logMessage", window_log_message)
+        self.server.on_request("workspace/executeClientCommand", execute_client_command_handler)
+        self.server.on_notification("$/progress", do_nothing)
+        self.server.on_notification("textDocument/publishDiagnostics", do_nothing)
+        self.server.on_notification("language/actionableNotification", do_nothing)
+        self.server.on_notification("experimental/serverStatus", check_experimental_status)
+
+        async with super().start_server():
+            self.logger.log("Starting Clangd server process", logging.INFO)
+            await self.server.start()
+            initialize_params = self._get_initialize_params(self.repository_root_path)
+
+            self.logger.log(
+                "Sending initialize request from LSP client to LSP server and awaiting response",
+                logging.INFO,
+            )
+            init_response = await self.server.send.initialize(initialize_params)
+            assert init_response["capabilities"]["textDocumentSync"]["change"] == 2
+            assert "completionProvider" in init_response["capabilities"]          
+            assert init_response["capabilities"]["completionProvider"] == {
+                "triggerCharacters": ['.', '<', '>', ':', '"', '/', '*'],
+                "resolveProvider": False,
+            }
+
+            self.server.notify.initialized({})
+
+            self.completions_available.set()
+            # set ready flag
+            self.server_ready.set()
+            await self.server_ready.wait()
+
+            yield self
+
+            await self.server.shutdown()
+            await self.server.stop()

src/multilspy/language_servers/clangd_language_server/initialize_params.json

@@ -0,0 +1,36 @@
+{
+    "_description": "The parameters sent by the client when initializing the language server with the \"initialize\" request. More details at https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initialize",
+    "processId": "os.getpid()",
+    "locale": "en",
+    "rootPath": "$rootPath",
+    "rootUri": "$rootUri",
+    "capabilities": {
+        "textDocument": {
+            "synchronization": {
+                "didSave": true,
+                "dynamicRegistration": true
+            },
+            "completion": {
+                "dynamicRegistration": true,
+                "completionItem": {
+                    "snippetSupport": true
+                }
+            },
+            "definition": {
+                "dynamicRegistration": true
+            }
+        },
+        "workspace": {
+            "workspaceFolders": true,
+            "didChangeConfiguration": {
+                "dynamicRegistration": true
+            }
+        }
+    },
+    "workspaceFolders": [
+        {
+            "uri": "$uri",
+            "name": "$name"
+        }
+    ]
+}

src/multilspy/language_servers/clangd_language_server/runtime_dependencies.json

@@ -0,0 +1,13 @@
+{
+    "_description": "Used to download the runtime dependencies for running Clangd.",
+    "runtimeDependencies": [
+        {
+            "id": "Clangd",
+            "description": "Clangd for Linux (x64)",
+            "url": "https://github.com/clangd/clangd/releases/download/19.1.2/clangd-linux-19.1.2.zip",
+            "platformId": "linux-x64",
+            "archiveType": "zip",
+            "binaryName": "clangd"
+        }
+    ]
+}

src/multilspy/multilspy_config.py

@@ -20,6 +20,7 @@ class Language(str, Enum):
     GO = "go"
     RUBY = "ruby"
     DART = "dart"
+    CPP = "cpp"
 
     def __str__(self) -> str:
         return self.value

tests/multilspy/test_multilspy_clangd.py

@@ -0,0 +1,70 @@
+"""
+This file contains tests for running the C/CPP Language Server: clangd
+"""
+
+import pytest
+import os
+
+from multilspy import LanguageServer
+from multilspy.multilspy_config import Language
+from tests.test_utils import create_test_context
+from pathlib import PurePath
+
+pytest_plugins = ("pytest_asyncio",)
+
+def create_compile_commands_file(source_directory_path):
+    """
+    clangd requires compile_commands.json file to resolve dependencies in project.
+    This file contains information such as how the source files are compiled.
+    This file can be generated using different tools. CMake is used here to generate
+    this file. For other options check: https://clangd.llvm.org/installation.html#project-setup
+    """
+    # get current working directory
+    cwd = os.getcwd()
+    # switch to repo directory
+    os.chdir(source_directory_path)
+    # set cmake to export compile commands
+    os.system('cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=1 -S . -B build')
+    # generate build
+    os.system('cmake --build build')
+    # create sym link to compile commands at the top level
+    os.system('ln -s build/compile_commands.json .')
+    # return back to prev working dir
+    os.chdir(cwd)
+
+@pytest.mark.asyncio
+async def test_multilspy_clang():
+    """
+    Test the working of multilspy with cpp repository - https://github.com/tomorrowCoder/yaml-cpp
+    """
+    code_language = Language.CPP
+    params = {
+        "code_language": code_language,
+        "repo_url": "https://github.com/jbeder/yaml-cpp/",
+        "repo_commit": "39f737443b05e4135e697cb91c2b7b18095acd53"
+    }
+    with create_test_context(params) as context:
+        # create compile commands file before starting language server
+        create_compile_commands_file(context.source_directory)
+        # create language server
+        lsp = LanguageServer.create(context.config, context.logger, context.source_directory)
+
+        async with lsp.start_server():
+            # get definition for create_node
+            result = await lsp.request_definition(str(PurePath("src/node_data.cpp")), 241, 26)
+            assert isinstance(result, list)
+            assert len(result) > 0
+            assert result[0]["relativePath"] == str(PurePath("include/yaml-cpp/node/detail/memory.h"))
+
+            # find references for WriteCodePoint
+            result = await lsp.request_references(str(PurePath("src/emitterutils.cpp")), 134, 6)
+            assert isinstance(result, list)
+            assert len(result) == 5
+
+            # get hover information for strFormat variable
+            result = await lsp.request_hover(str(PurePath("src/emitterutils.cpp")), 274, 11)
+            assert result is not None
+
+            # get document symbols for binary.cpp
+            result = await lsp.request_document_symbols(str(PurePath("src/binary.cpp")))
+            assert isinstance(result, tuple)