Bug 558664 - Cquery integration should be extracted from LSP Core

Part 3:
Convert ContributedLanguageServers to OSGi component and switch usages
to its interface.
Convert LanguageServerConfiguration implementations to OSGi components.

Change-Id: Ic22fa26a7abfd40a959ae0189a63b9a04d1ac4e0
Signed-off-by: Alexander Fedorov <alexander.fedorov@arsysop.ru>

lsp/org.eclipse.cdt.lsp.core/.project

@@ -20,6 +20,11 @@
 			<arguments>
 			</arguments>
 		</buildCommand>
+		<buildCommand>
+			<name>org.eclipse.pde.ds.core.builder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
 	</buildSpec>
 	<natures>
 		<nature>org.eclipse.pde.PluginNature</nature>

lsp/org.eclipse.cdt.lsp.core/.settings/org.eclipse.pde.ds.annotations.prefs

@@ -0,0 +1,8 @@
+classpath=true
+dsVersion=V1_3
+eclipse.preferences.version=1
+enabled=true
+generateBundleActivationPolicyLazy=true
+path=OSGI-INF
+validationErrorLevel=error
+validationErrorLevel.missingImplicitUnbindMethod=error

lsp/org.eclipse.cdt.lsp.core/META-INF/MANIFEST.MF

@@ -18,6 +18,7 @@ Require-Bundle: com.google.gson;bundle-version="2.8.2",
  org.eclipse.lsp4j,
  org.eclipse.lsp4e,
  org.eclipse.lsp4j.jsonrpc,
+ org.eclipse.osgi.services;bundle-version="3.9.0";resolution:=optional,
  org.eclipse.cdt.core,
  org.eclipse.cdt.ui
 Import-Package: org.eclipse.ui.editors.text,
@@ -31,3 +32,6 @@ Export-Package: org.eclipse.cdt.cquery;x-friends:="org.eclipse.cdt.lsp.ui",
  org.eclipse.cdt.lsp.internal.text;x-friends:="org.eclipse.cdt.lsp.ui"
 Bundle-Activator: org.eclipse.cdt.lsp.core.Activator
 Bundle-ActivationPolicy: lazy
+Service-Component: OSGI-INF/org.eclipse.cdt.lsp.internal.core.ContributedLanguageServers.xml,
+ OSGI-INF/org.eclipse.cdt.internal.clangd.ClangdLanguageServer.xml,
+ OSGI-INF/org.eclipse.cdt.internal.cquery.CqueryLanguageServer.xml

lsp/org.eclipse.cdt.lsp.core/OSGI-INF/org.eclipse.cdt.internal.clangd.ClangdLanguageServer.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" name="org.eclipse.cdt.internal.clangd.ClangdLanguageServer">
+   <service>
+      <provide interface="org.eclipse.cdt.lsp.LanguageServerConfiguration"/>
+   </service>
+   <implementation class="org.eclipse.cdt.internal.clangd.ClangdLanguageServer"/>
+</scr:component>

lsp/org.eclipse.cdt.lsp.core/OSGI-INF/org.eclipse.cdt.internal.cquery.CqueryLanguageServer.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" name="org.eclipse.cdt.internal.cquery.CqueryLanguageServer">
+   <service>
+      <provide interface="org.eclipse.cdt.lsp.LanguageServerConfiguration"/>
+   </service>
+   <implementation class="org.eclipse.cdt.internal.cquery.CqueryLanguageServer"/>
+</scr:component>

lsp/org.eclipse.cdt.lsp.core/OSGI-INF/org.eclipse.cdt.lsp.internal.core.ContributedLanguageServers.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" name="org.eclipse.cdt.lsp.internal.core.ContributedLanguageServers">
+   <service>
+      <provide interface="org.eclipse.cdt.lsp.SupportedLanguageServers"/>
+   </service>
+   <reference bind="register" cardinality="0..n" interface="org.eclipse.cdt.lsp.LanguageServerConfiguration" name="register" unbind="unregister"/>
+   <implementation class="org.eclipse.cdt.lsp.internal.core.ContributedLanguageServers"/>
+</scr:component>

lsp/org.eclipse.cdt.lsp.core/src/org/eclipse/cdt/internal/clangd/ClangdLanguageServer.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2018 Manish Khurana , Nathan Ridge and others.
+ * Copyright (c) 2018, 2020 Manish Khurana , Nathan Ridge and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -14,9 +14,12 @@ package org.eclipse.cdt.internal.clangd;
 import java.net.URI;
 
 import org.eclipse.cdt.lsp.LanguageServerConfiguration;
+import org.osgi.service.component.annotations.Component;
 
+@Component
 public class ClangdLanguageServer implements LanguageServerConfiguration {
 
+	//FIXME: remove this constant, it is not needed outside the class
 	public static final String CLANGD_ID = "clangd"; //$NON-NLS-1$
 
 	@Override

lsp/org.eclipse.cdt.lsp.core/src/org/eclipse/cdt/internal/cquery/CqueryLanguageServer.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2018 Manish Khurana , Nathan Ridge and others.
+ * Copyright (c) 2018, 2020 Manish Khurana , Nathan Ridge and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -18,11 +18,14 @@ import org.eclipse.cdt.lsp.LanguageServerConfiguration;
 import org.eclipse.cdt.ui.CUIPlugin;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.Path;
+import org.osgi.service.component.annotations.Component;
 
 import com.google.gson.JsonObject;
 
+@Component
 public class CqueryLanguageServer implements LanguageServerConfiguration {
 
+	//FIXME: remove this constant, it is not needed outside the class
 	public static final String CQUERY_ID = "cquery"; //$NON-NLS-1$
 
 	@Override

lsp/org.eclipse.cdt.lsp.core/src/org/eclipse/cdt/lsp/SupportedLanguageServers.java

@@ -24,6 +24,6 @@ public interface SupportedLanguageServers {
 
 	Collection<LanguageServerConfiguration> all();
 
-	LanguageServerConfiguration preferred() throws IllegalStateException;
+	LanguageServerConfiguration preferred();
 
 }

lsp/org.eclipse.cdt.lsp.core/src/org/eclipse/cdt/lsp/core/CPPStreamConnectionProvider.java

@@ -25,13 +25,14 @@ import java.util.Arrays;
 import java.util.List;
 
 import org.eclipse.cdt.lsp.LanguageServerConfiguration;
-import org.eclipse.cdt.lsp.internal.core.ContributedLanguageServers;
+import org.eclipse.cdt.lsp.SupportedLanguageServers;
 import org.eclipse.cdt.utils.CommandLineUtil;
 import org.eclipse.core.resources.IContainer;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResourceChangeListener;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.Platform;
+import org.eclipse.core.runtime.ServiceCaller;
 import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.lsp4e.server.ProcessStreamConnectionProvider;
 
@@ -46,8 +47,7 @@ public class CPPStreamConnectionProvider extends ProcessStreamConnectionProvider
 	private final LanguageServerConfiguration configuration;
 
 	public CPPStreamConnectionProvider() throws UnsupportedOperationException {
-		//FIXME: should obtain an instance of interface
+		configuration = configuration();
-		configuration = new ContributedLanguageServers().preferred();
 		File defaultLSLocation = getDefaultLSLocation(configuration.identifier());
 		if (defaultLSLocation != null) {
 			store.setDefault(PreferenceConstants.P_SERVER_PATH, defaultLSLocation.getAbsolutePath());
@@ -67,6 +67,13 @@ public class CPPStreamConnectionProvider extends ProcessStreamConnectionProvider
 		setCommands(commands);
 	}
 
+	private LanguageServerConfiguration configuration() {
+		final LanguageServerConfiguration[] configs = new LanguageServerConfiguration[1];
+		ServiceCaller.callOnce(CPPStreamConnectionProvider.class, SupportedLanguageServers.class,
+				x -> configs[0] = x.preferred());
+		return configs[0];
+	}
+
 	@Override
 	public void stop() {
 		super.stop();

lsp/org.eclipse.cdt.lsp.core/src/org/eclipse/cdt/lsp/core/PreferenceInitializer.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2018 Manish Khurana , Nathan Ridge and others.
+ * Copyright (c) 2018, 2020 Manish Khurana , Nathan Ridge and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -12,7 +12,8 @@
 package org.eclipse.cdt.lsp.core;
 
 import org.eclipse.core.runtime.preferences.AbstractPreferenceInitializer;
-import org.eclipse.jface.preference.IPreferenceStore;
+import org.eclipse.core.runtime.preferences.DefaultScope;
+import org.eclipse.core.runtime.preferences.IEclipsePreferences;
 
 /**
  * Class used to initialize default preference values for C/C++ Preference Page.
@@ -21,9 +22,9 @@ public class PreferenceInitializer extends AbstractPreferenceInitializer {
 
 	@Override
 	public void initializeDefaultPreferences() {
-		IPreferenceStore store = Activator.getDefault().getPreferenceStore();
+		IEclipsePreferences node = DefaultScope.INSTANCE.getNode(Activator.PLUGIN_ID);
-		store.setDefault(PreferenceConstants.P_SERVER_CHOICE, "clangd"); //$NON-NLS-1$
+		node.put(PreferenceConstants.P_SERVER_CHOICE, "clangd"); //$NON-NLS-1$
-		store.setDefault(PreferenceConstants.P_SERVER_OPTIONS, ""); //$NON-NLS-1$
+		node.put(PreferenceConstants.P_SERVER_OPTIONS, ""); //$NON-NLS-1$
 	}
 
 }

lsp/org.eclipse.cdt.lsp.core/src/org/eclipse/cdt/lsp/internal/core/ContributedLanguageServers.java

@@ -16,26 +16,27 @@ package org.eclipse.cdt.lsp.internal.core;
 import java.util.Collection;
 import java.util.LinkedHashMap;
 import java.util.Map;
-import java.util.Optional;
 
-import org.eclipse.cdt.internal.clangd.ClangdLanguageServer;
-import org.eclipse.cdt.internal.cquery.CqueryLanguageServer;
 import org.eclipse.cdt.lsp.LanguageServerConfiguration;
 import org.eclipse.cdt.lsp.SupportedLanguageServers;
 import org.eclipse.cdt.lsp.core.PreferenceConstants;
-import org.eclipse.core.runtime.preferences.IEclipsePreferences;
+import org.eclipse.core.runtime.Platform;
+import org.eclipse.core.runtime.preferences.IScopeContext;
 import org.eclipse.core.runtime.preferences.InstanceScope;
 import org.osgi.framework.FrameworkUtil;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Reference;
+import org.osgi.service.component.annotations.ReferenceCardinality;
 
-//FIXME ok, not really contributed at the moment, but will be
+@Component
 public final class ContributedLanguageServers implements SupportedLanguageServers {
 
+	private final LanguageServerConfiguration undefined;
 	private final Map<String, LanguageServerConfiguration> configs;
 
 	public ContributedLanguageServers() {
 		configs = new LinkedHashMap<>();
-		register(new ClangdLanguageServer());
+		undefined = new UndefinedLanguageServer();
-		register(new CqueryLanguageServer());
 	}
 
 	@Override
@@ -43,6 +44,7 @@ public final class ContributedLanguageServers implements SupportedLanguageServer
 		return configs.values();
 	}
 
+	@Reference(cardinality = ReferenceCardinality.MULTIPLE)
 	public void register(LanguageServerConfiguration configuration) {
 		configs.put(configuration.identifier(), configuration);
 	}
@@ -52,13 +54,13 @@ public final class ContributedLanguageServers implements SupportedLanguageServer
 	}
 
 	@Override
-	public LanguageServerConfiguration preferred() throws IllegalStateException {
+	public LanguageServerConfiguration preferred() {
-		return Optional.ofNullable(InstanceScope.INSTANCE.getNode(nodeQualifier()))//
+		return configs.getOrDefault(preferredIdentifier(), undefined);
-				.filter(IEclipsePreferences.class::isInstance)//
+	}
-				.map(IEclipsePreferences.class::cast)//
+
-				.flatMap(x -> Optional.ofNullable(x.get(nodePath(), null)))//
+	private String preferredIdentifier() {
-				.map(configs::get)//
+		return Platform.getPreferencesService().getString(nodeQualifier(), nodePath(), undefined.identifier(),
-				.orElseThrow(() -> new IllegalStateException("No preferred server was found"));
+				new IScopeContext[] { InstanceScope.INSTANCE });
 	}
 
 	private String nodeQualifier() {

lsp/org.eclipse.cdt.lsp.core/src/org/eclipse/cdt/lsp/internal/core/UndefinedLanguageServer.java

@@ -0,0 +1,37 @@
+/*******************************************************************************
+ * Copyright (c) 2020 ArSysOp and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Alexander Fedorov (ArSysOp) - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.lsp.internal.core;
+
+import java.net.URI;
+
+import org.eclipse.cdt.lsp.LanguageServerConfiguration;
+
+final class UndefinedLanguageServer implements LanguageServerConfiguration {
+
+	@Override
+	public String identifier() {
+		return ""; //$NON-NLS-1$
+	}
+
+	@Override
+	public String label() {
+		return "<undefined>";
+	}
+
+	@Override
+	public Object options(Object defaults, URI uri) {
+		return defaults;
+	}
+
+}