[gnome-builder/wip/beniofel/vala-langserv: 138/138] Add vala language server (wip)

[Ben Iofel <beniofel src gnome org>]

commit dada78cbfd53ef6ac1b62c388e0a1d1b11c35b80
Author: Ben Iofel <iofelben gmail com>
Date:   Wed Aug 2 15:43:41 2017 +0100

    Add vala language server (wip)

 meson_options.txt                             |    1 +
 plugins/meson.build                           |    2 +
 plugins/vala-langserv/meson.build             |   13 ++
 plugins/vala-langserv/vala-langserv.plugin    |   14 ++
 plugins/vala-langserv/vala_langserv_plugin.py |  172 +++++++++++++++++++++++++
 5 files changed, 202 insertions(+), 0 deletions(-)
---
diff --git a/meson_options.txt b/meson_options.txt
index 38ac26c..421c269 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -71,5 +71,6 @@ option('with_sysprof', type: 'boolean')
 option('with_terminal', type: 'boolean')
 option('with_todo', type: 'boolean')
 option('with_vala_pack', type: 'boolean')
+option('with_vala_langserv', type: 'boolean')
 option('with_valgrind', type: 'boolean')
 option('with_xml_pack', type: 'boolean')
diff --git a/plugins/meson.build b/plugins/meson.build
index c16c521..2494be4 100644
--- a/plugins/meson.build
+++ b/plugins/meson.build
@@ -60,6 +60,7 @@ subdir('sysprof')
 subdir('terminal')
 subdir('todo')
 subdir('vala-pack')
+subdir('vala-langserv')
 subdir('valgrind')
 subdir('xml-pack')
 
@@ -113,6 +114,7 @@ status += [
   'Terminal .............. : @0@'.format(get_option('with_terminal')),
   'Todo .................. : @0@'.format(get_option('with_todo')),
   'Vala Language Pack .... : @0@'.format(get_option('with_vala_pack')),
+  'Vala Language Sever ... : @0@'.format(get_option('with_vala_langserv')),
   'Valgrind .............. : @0@'.format(get_option('with_valgrind')),
   'XML Language Pack ..... : @0@'.format(get_option('with_xml_pack')),
   '', '',
diff --git a/plugins/vala-langserv/meson.build b/plugins/vala-langserv/meson.build
new file mode 100644
index 0000000..6002d6d
--- /dev/null
+++ b/plugins/vala-langserv/meson.build
@@ -0,0 +1,13 @@
+if get_option('with_vala_langserv')
+
+install_data('vala_langserv_plugin.py', install_dir: plugindir)
+
+configure_file(
+          input: 'vala-langserv.plugin',
+         output: 'vala-langserv.plugin',
+  configuration: configuration_data(),
+        install: true,
+    install_dir: plugindir,
+)
+
+endif
diff --git a/plugins/vala-langserv/vala-langserv.plugin b/plugins/vala-langserv/vala-langserv.plugin
new file mode 100644
index 0000000..a0e3152
--- /dev/null
+++ b/plugins/vala-langserv/vala-langserv.plugin
@@ -0,0 +1,14 @@
+[Plugin]
+Module=vala_langserv_plugin
+Loader=python3
+Name=Vala Language Server Integration
+Description=Provides auto-completion, diagnostics, and other IDE features
+Authors=Ben Iofel <iofelben gmail com>
+Copyright=Copyright © 2017 Ben Iofel
+Builtin=true
+X-Completion-Provider-Languages=vala
+X-Diagnostic-Provider-Languages=vala
+X-Formatter-Languages=vala
+X-Highlighter-Languages=vala
+X-Rename-Provider-Languages=vala
+X-Symbol-Resolver-Languages=vala
diff --git a/plugins/vala-langserv/vala_langserv_plugin.py b/plugins/vala-langserv/vala_langserv_plugin.py
new file mode 100644
index 0000000..18912a4
--- /dev/null
+++ b/plugins/vala-langserv/vala_langserv_plugin.py
@@ -0,0 +1,172 @@
+#!/usr/bin/env python
+
+# vala_langserv_plugin.py
+#
+# Copyright (C) 2016 Christian Hergert <chergert redhat com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+This plugin provides integration with the Vala Language Server.
+It builds off the generic language service components in libide
+by bridging them to our supervised Vala Language Server.
+"""
+
+import gi
+import os
+
+gi.require_version('Ide', '1.0')
+gi.require_version('GtkSource', '3.0')
+
+from gi.repository import GLib
+from gi.repository import Gio
+from gi.repository import GObject
+from gi.repository import GtkSource
+from gi.repository import Ide
+
+DEV_MODE = True
+
+class ValaService(Ide.Object, Ide.Service):
+    _client = None
+    _has_started = False
+    _supervisor = None
+
+    @GObject.Property(type=Ide.LangservClient)
+    def client(self):
+        return self._client
+
+    @client.setter
+    def client(self, value):
+        self._client = value
+        self.notify('client')
+
+    def do_stop(self):
+        """
+        Stops the Vala Language Server upon request to shutdown the
+        ValaService.
+        """
+        if self._supervisor:
+            supervisor, self._supervisor = self._supervisor, None
+            supervisor.stop()
+
+    def _ensure_started(self):
+        """
+        Start the vala service which provides communication with the
+        Vala Language Server. We supervise our own instance of the
+        language server and restart it as necessary using the
+        Ide.SubprocessSupervisor.
+
+        Various extension points (diagnostics, symbol providers, etc) use
+        the ValaService to access the vala components they need.
+        """
+        # To avoid starting the `rls` process unconditionally at startup,
+        # we lazily start it when the first provider tries to bind a client
+        # to its :client property.
+        if not self._has_started:
+            self._has_started = True
+
+            # Setup a launcher to spawn the vala language server
+            launcher = self._create_launcher()
+            launcher.set_clear_env(False)
+            if DEV_MODE:
+                launcher.setenv('JSONRPC_DEBUG', '1', True)
+
+            # Locate the directory of the project and run rls from there.
+            workdir = self.get_context().get_vcs().get_working_directory()
+            launcher.set_cwd(workdir.get_path())
+
+            path_to_vls = "/home/ben/dev/vala-language-server/build/vala-language-server"
+
+            # Setup our Argv. We want to communicate over STDIN/STDOUT,
+            # so it does not require any command line options.
+            launcher.push_argv(path_to_vls)
+
+            # Spawn our peer process and monitor it for
+            # crashes. We may need to restart it occasionally.
+            self._supervisor = Ide.SubprocessSupervisor()
+            self._supervisor.connect('spawned', self._vls_spawned)
+            self._supervisor.set_launcher(launcher)
+            self._supervisor.start()
+
+    def _vls_spawned(self, supervisor, subprocess):
+        """
+        This callback is executed when the `vls` process is spawned.
+        We can use the stdin/stdout to create a channel for our
+        LangservClient.
+        """
+        stdin = subprocess.get_stdin_pipe()
+        stdout = subprocess.get_stdout_pipe()
+        io_stream = Gio.SimpleIOStream.new(stdout, stdin)
+
+        if self._client:
+            self._client.stop()
+
+        self._client = Ide.LangservClient.new(self.get_context(), io_stream)
+        self._client.add_language('vala')
+        self._client.start()
+        self.notify('client')
+
+    def _create_launcher(self):
+        """
+        Creates a launcher to be used by the vala service. This needs
+        to be run on the host because we do not currently bundle vala
+        inside our flatpak.
+
+        In the future, we might be able to rely on the runtime for
+        the tooling. Maybe even the program if flatpak-builder has
+        prebuilt our dependencies.
+        """
+        flags = Gio.SubprocessFlags.STDIN_PIPE | Gio.SubprocessFlags.STDOUT_PIPE
+        if not DEV_MODE:
+            flags |= Gio.SubprocessFlags.STDERR_SILENCE
+        launcher = Ide.SubprocessLauncher()
+        launcher.set_flags(flags)
+        launcher.set_cwd(GLib.get_home_dir())
+        launcher.set_run_on_host(True)
+        return launcher
+
+    @classmethod
+    def bind_client(klass, provider):
+        """
+        This helper tracks changes to our client as it might happen when
+        our `rls` process has crashed.
+        """
+        context = provider.get_context()
+        self = context.get_service_typed(ValaService)
+        self._ensure_started()
+        self.bind_property('client', provider, 'client', GObject.BindingFlags.SYNC_CREATE)
+
+class ValaDiagnosticProvider(Ide.LangservDiagnosticProvider):
+    def do_load(self):
+        ValaService.bind_client(self)
+
+class ValaCompletionProvider(Ide.LangservCompletionProvider):
+    def do_load(self, context):
+        ValaService.bind_client(self)
+
+class ValaRenameProvider(Ide.LangservRenameProvider):
+    def do_load(self):
+        ValaService.bind_client(self)
+
+class ValaSymbolResolver(Ide.LangservSymbolResolver):
+    def do_load(self):
+        ValaService.bind_client(self)
+
+class ValaHighlighter(Ide.LangservHighlighter):
+    def do_load(self):
+        ValaService.bind_client(self)
+
+class ValaFormatter(Ide.LangservFormatter):
+    def do_load(self):
+        ValaService.bind_client(self)