HackStudio: Send an open file to language servers

Language servers will now receive an open file instead of just its path. This
means the language servers no longer need to access the filesystem to open the
file themselves.

The C++ language server now has no filesystem access whatsoever (although we
might need to relax this in the future if it learns to complete #include paths),
while the Shell language server can read /etc/passwd (it wants that in order to
get the user's home directory) and browse (but not read!) the whole file system
tree for completing paths.

DevTools/HackStudio/Editor.cpp

@@ -48,6 +48,7 @@
 #include <LibWeb/DOM/Text.h>
 #include <LibWeb/HTML/HTMLHeadElement.h>
 #include <LibWeb/OutOfProcessWebView.h>
+#include <fcntl.h>
 
 // #define EDITOR_DEBUG
 
@@ -480,8 +481,17 @@ void Editor::set_document(GUI::TextDocument& doc)
         set_syntax_highlighter(nullptr);
     }
 
-    if (m_language_client)
-        m_language_client->open_file(code_document.file_path().string());
+    if (m_language_client) {
+        auto full_file_path = String::formatted("{}/{}", project().root_directory(), code_document.file_path());
+        dbg() << "Opening " << full_file_path;
+        int fd = open(full_file_path.characters(), O_RDONLY | O_NOCTTY);
+        if (fd < 0) {
+            perror("open");
+            return;
+        }
+        m_language_client->open_file(code_document.file_path().string(), fd);
+        close(fd);
+    }
 }
 
 Optional<Editor::AutoCompleteRequestData> Editor::get_autocomplete_request_data()

DevTools/HackStudio/LanguageClient.cpp

@@ -36,9 +36,9 @@ void ServerConnection::handle(const Messages::LanguageClient::AutoCompleteSugges
         m_language_client->provide_autocomplete_suggestions(message.suggestions());
 }
 
-void LanguageClient::open_file(const String& path)
+void LanguageClient::open_file(const String& path, int fd)
 {
-    m_connection.post_message(Messages::LanguageServer::FileOpened(path));
+    m_connection.post_message(Messages::LanguageServer::FileOpened(path, fd));
 }
 
 void LanguageClient::set_file_content(const String& path, const String& content)

DevTools/HackStudio/LanguageClient.h

@@ -43,9 +43,8 @@ class ServerConnection
     : public IPC::ServerConnection<LanguageClientEndpoint, LanguageServerEndpoint>
     , public LanguageClientEndpoint {
 public:
-    ServerConnection(const StringView& socket, const StringView& project_path)
+    ServerConnection(const StringView& socket)
         : IPC::ServerConnection<LanguageClientEndpoint, LanguageServerEndpoint>(*this, socket)
-        , m_project_path(project_path)
     {
     }
 
@@ -61,7 +60,7 @@ public:
 
     virtual void handshake() override
     {
-        auto response = send_sync<Messages::LanguageServer::Greet>(m_project_path.string());
+        auto response = send_sync<Messages::LanguageServer::Greet>();
         set_my_client_id(response->client_id());
     }
 
@@ -73,7 +72,7 @@ public:
         if (auto instance = s_instances_for_projects.get(key); instance.has_value())
             return *instance.value();
 
-        auto connection = ConcreteType::construct(project_path);
+        auto connection = ConcreteType::construct();
         connection->handshake();
         s_instances_for_projects.set(key, *connection);
         return *connection;
@@ -83,7 +82,6 @@ protected:
     virtual void handle(const Messages::LanguageClient::AutoCompleteSuggestions&) override;
 
     LanguageClient* m_language_client { nullptr };
-    LexicalPath m_project_path;
 };
 
 class LanguageClient {
@@ -100,7 +98,7 @@ public:
         m_connection.detach();
     }
 
-    virtual void open_file(const String& path);
+    virtual void open_file(const String& path, int fd);
     virtual void set_file_content(const String& path, const String& content);
     virtual void insert_text(const String& path, const String& text, size_t line, size_t column);
     virtual void remove_text(const String& path, size_t from_line, size_t from_column, size_t to_line, size_t to_column);

DevTools/HackStudio/LanguageClients/ServerConnections.h

@@ -32,16 +32,16 @@
 #include <DevTools/HackStudio/LanguageServers/LanguageServerEndpoint.h>
 #include <LibIPC/ServerConnection.h>
 
-#define LANGUAGE_CLIENT(namespace_, socket_name)                                               \
-    namespace namespace_ {                                                                     \
-    class ServerConnection : public HackStudio::ServerConnection {                             \
-        C_OBJECT(ServerConnection)                                                             \
-    private:                                                                                   \
-        ServerConnection(const String& project_path)                                           \
-            : HackStudio::ServerConnection("/tmp/portal/language/" #socket_name, project_path) \
-        {                                                                                      \
-        }                                                                                      \
-    };                                                                                         \
+#define LANGUAGE_CLIENT(namespace_, socket_name)                                 \
+    namespace namespace_ {                                                       \
+    class ServerConnection : public HackStudio::ServerConnection {               \
+        C_OBJECT(ServerConnection)                                               \
+    private:                                                                     \
+        ServerConnection()                                                       \
+            : HackStudio::ServerConnection("/tmp/portal/language/" #socket_name) \
+        {                                                                        \
+        }                                                                        \
+    };                                                                           \
     }
 
 namespace LanguageClients {

DevTools/HackStudio/LanguageServers/Cpp/ClientConnection.cpp

@@ -53,12 +53,8 @@ void ClientConnection::die()
     exit(0);
 }
 
-OwnPtr<Messages::LanguageServer::GreetResponse> ClientConnection::handle(const Messages::LanguageServer::Greet& message)
+OwnPtr<Messages::LanguageServer::GreetResponse> ClientConnection::handle(const Messages::LanguageServer::Greet&)
 {
-    m_project_root = LexicalPath(message.project_root());
-#ifdef DEBUG_CPP_LANGUAGE_SERVER
-    dbgln("project_root: {}", m_project_root);
-#endif
     return make<Messages::LanguageServer::GreetResponse>(client_id());
 }
 
@@ -81,16 +77,11 @@ static DefaultDocumentClient s_default_document_client;
 
 void ClientConnection::handle(const Messages::LanguageServer::FileOpened& message)
 {
-    LexicalPath file_path(String::formatted("{}/{}", m_project_root, message.file_name()));
-#ifdef DEBUG_CPP_LANGUAGE_SERVER
-    dbgln("FileOpened: {}", file_path);
-#endif
-
-    auto file = Core::File::construct(file_path.string());
-    if (!file->open(Core::IODevice::ReadOnly)) {
+    auto file = Core::File::construct(this);
+    if (!file->open(message.file().fd(), Core::IODevice::ReadOnly, Core::File::ShouldCloseFileDescriptor::Yes)) {
         errno = file->error();
         perror("open");
-        dbgln("Failed to open project file: {}", file_path);
+        dbgln("Failed to open project file");
         return;
     }
     auto content = file->read_all();

DevTools/HackStudio/LanguageServers/Cpp/ClientConnection.h

@@ -58,7 +58,6 @@ private:
 
     RefPtr<GUI::TextDocument> document_for(const String& file_name);
 
-    LexicalPath m_project_root;
     HashMap<String, NonnullRefPtr<GUI::TextDocument>> m_open_files;
 };
 

DevTools/HackStudio/LanguageServers/Cpp/main.cpp

@@ -36,16 +36,20 @@
 int main(int, char**)
 {
     Core::EventLoop event_loop;
-    if (pledge("stdio unix rpath", nullptr) < 0) {
+    if (pledge("stdio unix recvfd", nullptr) < 0) {
         perror("pledge");
         return 1;
     }
 
     auto socket = Core::LocalSocket::take_over_accepted_socket_from_system_server();
     IPC::new_client_connection<LanguageServers::Cpp::ClientConnection>(socket.release_nonnull(), 1);
-    if (pledge("stdio rpath", nullptr) < 0) {
+    if (pledge("stdio recvfd", nullptr) < 0) {
         perror("pledge");
         return 1;
     }
+    if (unveil(nullptr, nullptr) < 0) {
+        perror("unveil");
+        return 1;
+    }
     return event_loop.exec();
 }

DevTools/HackStudio/LanguageServers/LanguageServer.ipc

@@ -1,8 +1,8 @@
 endpoint LanguageServer = 8001
 {
-    Greet(String project_root) => (i32 client_id)
+    Greet() => (i32 client_id)
 
-    FileOpened(String file_name) =|
+    FileOpened(String file_name, IPC::File file) =|
     FileEditInsertText(String file_name, String text, i32 start_line, i32 start_column) =|
     FileEditRemoveText(String file_name, i32 start_line, i32 start_column, i32 end_line, i32 end_column) =|
     SetFileContent(String file_name, String content) =|

DevTools/HackStudio/LanguageServers/Shell/ClientConnection.cpp

@@ -53,12 +53,8 @@ void ClientConnection::die()
     exit(0);
 }
 
-OwnPtr<Messages::LanguageServer::GreetResponse> ClientConnection::handle(const Messages::LanguageServer::Greet& message)
+OwnPtr<Messages::LanguageServer::GreetResponse> ClientConnection::handle(const Messages::LanguageServer::Greet&)
 {
-    m_project_root = LexicalPath(message.project_root());
-#ifdef DEBUG_SH_LANGUAGE_SERVER
-    dbgln("project_root: {}", m_project_root);
-#endif
     return make<Messages::LanguageServer::GreetResponse>(client_id());
 }
 
@@ -81,16 +77,11 @@ static DefaultDocumentClient s_default_document_client;
 
 void ClientConnection::handle(const Messages::LanguageServer::FileOpened& message)
 {
-    LexicalPath file_path(String::formatted("{}/{}", m_project_root, message.file_name()));
-#ifdef DEBUG_SH_LANGUAGE_SERVER
-    dbgln("FileOpened: {}", file_path);
-#endif
-
-    auto file = Core::File::construct(file_path.string());
-    if (!file->open(Core::IODevice::ReadOnly)) {
+    auto file = Core::File::construct(this);
+    if (!file->open(message.file().fd(), Core::IODevice::ReadOnly, Core::File::ShouldCloseFileDescriptor::Yes)) {
         errno = file->error();
         perror("open");
-        dbgln("Failed to open project file: {}", file_path);
+        dbgln("Failed to open project file");
         return;
     }
     auto content = file->read_all();

DevTools/HackStudio/LanguageServers/Shell/ClientConnection.h

@@ -59,7 +59,6 @@ private:
 
     RefPtr<GUI::TextDocument> document_for(const String& file_name);
 
-    LexicalPath m_project_root;
     HashMap<String, NonnullRefPtr<GUI::TextDocument>> m_open_files;
 
     AutoComplete m_autocomplete;

DevTools/HackStudio/LanguageServers/Shell/main.cpp

@@ -36,16 +36,28 @@
 int main(int, char**)
 {
     Core::EventLoop event_loop;
-    if (pledge("stdio unix rpath", nullptr) < 0) {
+    if (pledge("stdio unix rpath recvfd", nullptr) < 0) {
         perror("pledge");
         return 1;
     }
 
     auto socket = Core::LocalSocket::take_over_accepted_socket_from_system_server();
     IPC::new_client_connection<LanguageServers::Shell::ClientConnection>(socket.release_nonnull(), 1);
-    if (pledge("stdio rpath", nullptr) < 0) {
+    if (pledge("stdio rpath recvfd", nullptr) < 0) {
         perror("pledge");
         return 1;
     }
+    if (unveil("/etc/passwd", "r") < 0) {
+        perror("unveil");
+        return 1;
+    }
+    if (unveil("/", "b") < 0) {
+        perror("unveil");
+        return 1;
+    }
+    if (unveil(nullptr, nullptr) < 0) {
+        perror("unveil");
+        return 1;
+    }
     return event_loop.exec();
 }

DevTools/HackStudio/main.cpp

@@ -59,14 +59,14 @@ static void open_default_project_file(const String& project_path);
 
 int main(int argc, char** argv)
 {
-    if (pledge("stdio tty accept rpath cpath wpath shared_buffer proc exec unix fattr thread unix", nullptr) < 0) {
+    if (pledge("stdio tty accept rpath cpath wpath shared_buffer proc exec unix fattr thread unix sendfd", nullptr) < 0) {
         perror("pledge");
         return 1;
     }
 
     auto app = GUI::Application::construct(argc, argv);
 
-    if (pledge("stdio tty accept rpath cpath wpath shared_buffer proc exec fattr thread unix", nullptr) < 0) {
+    if (pledge("stdio tty accept rpath cpath wpath shared_buffer proc exec fattr thread unix sendfd", nullptr) < 0) {
         perror("pledge");
         return 1;
     }