.github/workflows/licensecheck.yml

@@ -18,4 +18,6 @@ jobs:
     with:
       projectId: tools.cdt
     secrets:
-      gitlabAPIToken: ${{ secrets.GITLAB_API_TOKEN }}
+      gitlabAPIToken: ${{ secrets.GITLAB_API_TOKEN }}
+    permissions:
+      pull-requests: write

CHANGELOG.md

@@ -5,3 +5,11 @@
 - First release of CDT LSP
 
 Fixed issues: <https://github.com/eclipse-cdt/cdt-lsp/milestone/1?closed=1>
+
+### v1.1.0 (Feb 2024)
+
+- Added basic spelling support
+- Added .clangd configuration file syntax checker
+- Added basic clangd LSP extension support for textDocument/ast and textDocument/symbolInfo
+
+Fixed issues: <https://github.com/eclipse-cdt/cdt-lsp/milestone/2?closed=1>

README.md

@@ -1,6 +1,6 @@
 # Eclipse CDT LSP - LSP based C/C++ Editor
 
-**Target audience** are Eclipse plugin developers who want to use/develop a LSP based C/C++ Editor.
+**Target audience** CDT users who want to use a language server based C/C++ Editor which supports newer C/C++ standards and Eclipse plugin developers who want to use/develop a LSP based C/C++ Editor. The editor in this Eclipse feature is backed by the [LLVM clangd C/C++ language server](https://clangd.llvm.org/).
 
 This plugin is based on the [LSP4E](https://github.com/eclipse/lsp4e) and [TM4E](https://github.com/eclipse/tm4e) Eclipse projects. The editor is based on the [`ExtensionBasedTextEditor`](https://github.com/eclipse-platform/eclipse.platform.ui/blob/master/bundles/org.eclipse.ui.genericeditor/src/org/eclipse/ui/internal/genericeditor/ExtensionBasedTextEditor.java#L55-L56) in Eclipse.
 
@@ -52,7 +52,7 @@ int main() {
 -->
 
 The Editors features depends on the support on client ([LSP4E](https://github.com/eclipse/lsp4e)) and server ([clangd](https://clangd.llvm.org/)) side.
-Currently these feature are supported (clangd 15 and 16) and current LSP4E:
+Currently these feature are supported (clangd 17) and current LSP4E:
 
 - Auto completion
 - Hovering
@@ -70,8 +70,11 @@ Not supported (yet):
 
 ### Activating LSP based C/C++ Editor
 
-The `org.eclipse.cdt.lsp.clangd` plugin provides an activation UI for the LSP based C/C++ Editor on project and workspace level. 
-The clangd language server path and the arguments can be changed in the workspace preferences as well:
+The `org.eclipse.cdt.lsp` plugin provides an activation UI for the LSP based C/C++ Editor on project and workspace level.
+
+![image](images/editor.png "editor.png")
+
+The clangd path and the arguments can be changed in the workspace preferences as well:
 
 ![image](images/preferences.png "preferences.png")
 
@@ -108,7 +111,17 @@ The following tools are needed on the `PATH` to operate the demo.
 
 ### Import an existing project
 
-You can import an existing project that contains a `compile_commands.json` file, or follow these instructions to create a simple starting project.
+You can import an existing project that contains a `compile_commands.json` file, or follow these instructions to create a simple starting project. 
+The language server (clangd) searches for a `compile_commands.json` file in the source file folder and its parents. Users can define a `.clangd` file in the project root to configure clangd (e.g. add include paths).
+A [.clangd](https://clangd.llvm.org/config#files) is a text file with YAML syntax. A `compile_commands.json` file can be generated by CMake.
+
+> [!TIP] 
+> This configuration entry in the `.clangd` file would tell clangd to use the `compile_commands.json` file in the build/default folder:
+
+```yaml
+CompileFlags:
+  CompilationDatabase: build/default
+```
 
 ### Create an example CMake project
 
@@ -126,14 +139,13 @@ This file may be hidden by default, therefore to see the file uncheck the *.\* r
 ### Open a file
 
 By default C/C++ will be opened with the standard CEditor.
-The default can be changed per project or per workspace with the *C/C++ General* -> *Editor (LSP)* -> *Prefer C/C++ Editor (LSP)* checkbox in the project setting or preferences.
-
-- Note: The workspace setting will be used for projects that have not checked the *Enable project specific settings* checkbox in the project properties -> *C/C++ General* -> *Editor (LSP)* page.
-
-Alternatively, you can choose which editor to open the file by using *Open With*:
+The default can be changed per project or per workspace with the *C/C++ General* -> *Editor (LSP)* -> *Set C/C++ Editor (LSP) as default* checkbox in the project properties or workspace preference page.
 
-![open-with.png](images/open-with.png "open-with.png")
+> [!TIP]
+> The workspace setting will be used for projects that have not checked the *Enable project specific settings* checkbox in the project properties -> *C/C++ General* -> *Editor (LSP)* page.
 
+> [!IMPORTANT]
+> Opening a C/C++ file using *Open With* in the context menu of a file won't work for the LSP based editor, because the language server won't be started if *Set C/C++ Editor (LSP) as default* is not enabled!
 
 With the *C/C++ Editor (LSP)* open, the presentation of the C++ file will follow the LSP4E conventions augmented by the information returned from clangd.
 
@@ -148,6 +160,7 @@ For plug-in dependencies the MANIFEST.MF's dependency information will provide t
 | CDT LSP Version | clangd | cmake* | Eclipse IDE Release |
 |:-:|:-:|:-:|:-:|
 | 1.0.x | 15.0.x | 3.x | 2023-09 |
+| 1.1.x | 17.0.x | 3.x | 2023-12 |
 
 \* cmake is required to run through the demo flow, but any tool that can create compile_commands.json or otherwise feed settings to clangd is suitable.
 

bundles/org.eclipse.cdt.lsp.clangd/META-INF/MANIFEST.MF

@@ -24,14 +24,17 @@ Require-Bundle: org.eclipse.cdt.lsp;bundle-version="0.0.0",
  org.eclipse.core.runtime;bundle-version="0.0.0",
  org.eclipse.jface;bundle-version="0.0.0",
  org.eclipse.jface.text;bundle-version="0.0.0",
- org.eclipse.lsp4e;bundle-version="0.16.1",
+ org.eclipse.lsp4e;bundle-version="0.18.0",
  org.eclipse.lsp4j;bundle-version="0.0.0",
  org.eclipse.ui.editors;bundle-version="0.0.0",
  org.eclipse.ui.ide;bundle-version="0.0.0",
  org.eclipse.ui.workbench;bundle-version="0.0.0",
- org.eclipse.ui.workbench.texteditor;bundle-version="0.0.0"
-Bundle-Activator: org.eclipse.cdt.lsp.internal.clangd.editor.ClangdPlugin
+ org.eclipse.ui.workbench.texteditor;bundle-version="0.0.0",
+ org.eclipse.core.variables;bundle-version="0.0.0",
+ org.yaml.snakeyaml;bundle-version="0.0.0"
 Service-Component: OSGI-INF/org.eclipse.cdt.lsp.clangd.BuiltinClangdOptionsDefaults.xml,
+ OSGI-INF/org.eclipse.cdt.lsp.clangd.ClangdConfigurationFileManager.xml,
  OSGI-INF/org.eclipse.cdt.lsp.internal.clangd.ClangdConfigurationAccess.xml,
  OSGI-INF/org.eclipse.cdt.lsp.internal.clangd.ClangdFallbackManager.xml,
  OSGI-INF/org.eclipse.cdt.lsp.internal.clangd.ClangdMetadataDefaults.xml
+Bundle-Activator: org.eclipse.cdt.lsp.internal.clangd.editor.ClangdPlugin

bundles/org.eclipse.cdt.lsp.clangd/OSGI-INF/org.eclipse.cdt.lsp.clangd.ClangdConfigurationFileManager.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.3.0" name="org.eclipse.cdt.lsp.clangd.ClangdConfigurationFileManager">
+   <property name="service.ranking" type="Integer" value="0"/>
+   <service>
+      <provide interface="org.eclipse.cdt.lsp.clangd.ClangdCProjectDescriptionListener"/>
+   </service>
+   <reference cardinality="1..1" field="build" interface="org.eclipse.cdt.core.build.ICBuildConfigurationManager" name="build"/>
+   <implementation class="org.eclipse.cdt.lsp.clangd.ClangdConfigurationFileManager"/>
+</scr:component>

bundles/org.eclipse.cdt.lsp.clangd/plugin.xml

@@ -110,5 +110,16 @@
          </command>
       </menuContribution>
    </extension>
+   <extension
+         id="org.eclipse.cdt.lsp.clangd.config.marker"
+         name=".clangd yaml Problem"
+         point="org.eclipse.core.resources.markers">
+      <super
+            type="org.eclipse.core.resources.problemmarker">
+      </super>
+      <persistent
+            value="true">
+      </persistent>
+   </extension>   
 
 </plugin>

bundles/org.eclipse.cdt.lsp.clangd/src/org/eclipse/cdt/lsp/clangd/ClangdCProjectDescriptionListener.java

@@ -0,0 +1,32 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Bachmann electronic GmbH and others.
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Gesa Hentschke (Bachmann electronic GmbH) - initial implementation
+ *******************************************************************************/
+
+package org.eclipse.cdt.lsp.clangd;
+
+import org.eclipse.cdt.core.settings.model.CProjectDescriptionEvent;
+
+/**
+ * Vendors may implement this interface as OSGi service
+ * with a service.ranking property > 0 to implement custom behavior
+ * and to replace the {@link ClangdConfigurationFileManager}
+ */
+public interface ClangdCProjectDescriptionListener {
+
+	/**
+	 * Called when the configuration of a CDT C/C++ project changes.
+	 * @param event
+	 * @param macroResolver helper class to resolve macros in builder CWD
+	 */
+	void handleEvent(CProjectDescriptionEvent event, MacroResolver macroResolver);
+
+}

bundles/org.eclipse.cdt.lsp.clangd/src/org/eclipse/cdt/lsp/clangd/ClangdConfigurationFileManager.java

@@ -0,0 +1,232 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Bachmann electronic GmbH and others.
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Gesa Hentschke (Bachmann electronic GmbH) - initial implementation
+ *******************************************************************************/
+
+package org.eclipse.cdt.lsp.clangd;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.Map;
+import java.util.Optional;
+
+import org.eclipse.cdt.core.build.CBuildConfiguration;
+import org.eclipse.cdt.core.build.ICBuildConfiguration;
+import org.eclipse.cdt.core.build.ICBuildConfigurationManager;
+import org.eclipse.cdt.core.cdtvariables.CdtVariableException;
+import org.eclipse.cdt.core.settings.model.CProjectDescriptionEvent;
+import org.eclipse.cdt.core.settings.model.ICConfigurationDescription;
+import org.eclipse.cdt.core.settings.model.ICProjectDescription;
+import org.eclipse.cdt.lsp.LspPlugin;
+import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.core.runtime.Platform;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Reference;
+import org.yaml.snakeyaml.Yaml;
+import org.yaml.snakeyaml.scanner.ScannerException;
+
+/**
+ * Default implementation of the {@link ClangdCProjectDescriptionListener}.
+ * Can be extended by vendors if needed. This implementation sets the path to
+ * the compile_commands.json in the .clangd file in the projects root directory.
+ * This is needed by CDT projects since the compile_commands.json is generated in the build folder.
+ * When the active build configuration changes in managed build projects, this manager updates the path to the database in
+ * the .clangd file to ensure that clangd uses the compile_commads.json of the active build configuration.
+ *
+ * This class can be extended by vendors.
+ */
+@Component(property = { "service.ranking:Integer=0" })
+public class ClangdConfigurationFileManager implements ClangdCProjectDescriptionListener {
+	public static final String CLANGD_CONFIG_FILE_NAME = ".clangd"; //$NON-NLS-1$
+	private static final String COMPILE_FLAGS = "CompileFlags"; //$NON-NLS-1$
+	private static final String COMPILATTION_DATABASE = "CompilationDatabase"; //$NON-NLS-1$
+	private static final String SET_COMPILATION_DB = COMPILE_FLAGS + ": {" + COMPILATTION_DATABASE + ": %s}"; //$NON-NLS-1$ //$NON-NLS-2$
+	private static final String EMPTY = ""; //$NON-NLS-1$
+
+	@Reference
+	private ICBuildConfigurationManager build;
+
+	@Override
+	public void handleEvent(CProjectDescriptionEvent event, MacroResolver macroResolver) {
+		setCompilationDatabasePath(event.getProject(), event.getNewCProjectDescription(), macroResolver);
+	}
+
+	/**
+	 * Set the <code>CompilationDatabase</code> entry in the <code>.clangd</code> file which is located in the <code>project</code> root,
+	 * if the yaml file syntax can be parsed.
+	 * The <code>.clangd</code> file will be created, if it's not existing.
+	 * The <code>CompilationDatabase</code> points to the build folder of the active build configuration
+	 * (in case <code>project</code> is a managed C/C++ project).
+	 *
+	 * In the following example clangd uses the compile_commands.json file in the Debug folder:
+	 * <pre>CompileFlags: {CompilationDatabase: Debug}</pre>
+	 *
+	 * @param project C/C++ project
+	 * @param newCProjectDescription new CProject description
+	 * @param macroResolver helper to resolve macros in the CWD path of the builder
+	 */
+	protected void setCompilationDatabasePath(IProject project, ICProjectDescription newCProjectDescription,
+			MacroResolver macroResolver) {
+		if (project != null && newCProjectDescription != null) {
+			if (enableSetCompilationDatabasePath(project)) {
+				var relativeDatabasePath = getRelativeDatabasePath(project, newCProjectDescription, macroResolver);
+				if (!relativeDatabasePath.isEmpty()) {
+					setCompilationDatabase(project, relativeDatabasePath);
+				} else {
+					Platform.getLog(getClass()).error("Cannot determine path to compile_commands.json"); //$NON-NLS-1$
+				}
+			}
+		}
+	}
+
+	/**
+	 * Enabler for {@link setCompilationDatabasePath}. Can be overriden for customization.
+	 * @param project
+	 * @return true if the database path should be written to .clangd file in the project root.
+	 */
+	protected boolean enableSetCompilationDatabasePath(IProject project) {
+		return Optional.ofNullable(LspPlugin.getDefault()).map(LspPlugin::getCLanguageServerProvider)
+				.map(provider -> provider.isEnabledFor(project)).orElse(Boolean.FALSE);
+	}
+
+	/**
+	 * Get project relative path to compile_commands.json file.
+	 * By de
+	 * @param project
+	 * @param newCProjectDescription
+	 * @param macroResolver
+	 * @return project relative path to active build folder or empty String
+	 */
+	private String getRelativeDatabasePath(IProject project, ICProjectDescription newCProjectDescription,
+			MacroResolver macroResolver) {
+		if (project != null && newCProjectDescription != null) {
+			ICConfigurationDescription config = newCProjectDescription.getDefaultSettingConfiguration();
+			var cwdBuilder = config.getBuildSetting().getBuilderCWD();
+			var projectLocation = project.getLocation().addTrailingSeparator().toOSString();
+			if (cwdBuilder != null) {
+				try {
+					var cwdString = macroResolver.resolveValue(cwdBuilder.toOSString(), EMPTY, null, config);
+					return cwdString.replace(projectLocation, EMPTY);
+				} catch (CdtVariableException e) {
+					Platform.getLog(getClass()).log(e.getStatus());
+				}
+			} else {
+				//it is probably a cmake project:
+				return buildConfiguration(project)//
+						.filter(CBuildConfiguration.class::isInstance)//
+						.map(bc -> {
+							try {
+								return ((CBuildConfiguration) bc).getBuildContainer();
+							} catch (CoreException e) {
+								Platform.getLog(getClass()).log(e.getStatus());
+							}
+							return null;
+						})//
+						.map(c -> c.getLocation())//
+						.map(l -> l.toOSString().replace(projectLocation, EMPTY)).orElse(EMPTY);
+			}
+		}
+		return EMPTY;
+	}
+
+	private Optional<ICBuildConfiguration> buildConfiguration(IResource initial) {
+		try {
+			var active = initial.getProject().getActiveBuildConfig();
+			if (active != null && build != null) {
+				return Optional.ofNullable(build.getBuildConfiguration(active));
+			}
+		} catch (CoreException e) {
+			Platform.getLog(getClass()).error(e.getMessage(), e);
+		}
+		return Optional.empty();
+	}
+
+	/**
+	 * Set the <code>CompilationDatabase</code> entry in the .clangd file in the given project root.
+	 * The file will be created, if it's not existing.
+	 * A ScannerException will be thrown if the configuration file contains invalid yaml syntax.
+	 *
+	 * @param project to write the .clangd file
+	 * @param databasePath project relative path to .clangd file
+	 * @throws IOException
+	 * @throws ScannerException
+	 * @throws CoreException
+	 */
+	@SuppressWarnings("unchecked")
+	public void setCompilationDatabase(IProject project, String databasePath) {
+		var configFile = project.getFile(CLANGD_CONFIG_FILE_NAME);
+		try {
+			if (createClangdConfigFile(configFile, project.getDefaultCharset(), databasePath, false)) {
+				return;
+			}
+			Map<String, Object> data = null;
+			Yaml yaml = new Yaml();
+			try (var inputStream = configFile.getContents()) {
+				//throws ScannerException and ParserException:
+				try {
+					data = yaml.load(inputStream);
+				} catch (Exception e) {
+					Platform.getLog(getClass()).error(e.getMessage(), e);
+					// return, since the file syntax is corrupted. The user has to fix it first:
+					return;
+				}
+			}
+			if (data == null) {
+				//empty file: (re)create .clangd file:
+				createClangdConfigFile(configFile, project.getDefaultCharset(), databasePath, true);
+				return;
+			}
+			Map<String, Object> map = (Map<String, Object>) data.get(COMPILE_FLAGS);
+			if (map != null) {
+				var cdb = map.get(COMPILATTION_DATABASE);
+				if (cdb != null && cdb instanceof String) {
+					if (cdb.equals(databasePath)) {
+						return;
+					}
+				}
+				map.put(COMPILATTION_DATABASE, databasePath);
+				data.put(COMPILE_FLAGS, map);
+				try (var yamlWriter = new PrintWriter(configFile.getLocation().toFile())) {
+					yaml.dump(data, yamlWriter);
+				}
+			}
+		} catch (CoreException e) {
+			Platform.getLog(getClass()).log(e.getStatus());
+		} catch (IOException e) {
+			Platform.getLog(getClass()).error(e.getMessage(), e);
+		}
+	}
+
+	private boolean createClangdConfigFile(IFile configFile, String charset, String databasePath,
+			boolean overwriteContent) {
+		if (!configFile.exists() || overwriteContent) {
+			try (final var data = new ByteArrayInputStream(
+					String.format(SET_COMPILATION_DB, databasePath).getBytes(charset))) {
+				if (overwriteContent) {
+					configFile.setContents(data, IResource.KEEP_HISTORY, new NullProgressMonitor());
+				} else {
+					configFile.create(data, false, new NullProgressMonitor());
+				}
+				return true;
+			} catch (CoreException e) {
+				Platform.getLog(getClass()).log(e.getStatus());
+			} catch (IOException e) {
+				Platform.getLog(getClass()).error(e.getMessage(), e);
+			}
+		}
+		return false;
+	}
+}

bundles/org.eclipse.cdt.lsp.clangd/src/org/eclipse/cdt/lsp/clangd/MacroResolver.java

@@ -0,0 +1,31 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Bachmann electronic GmbH and others.
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Gesa Hentschke (Bachmann electronic GmbH) - initial implementation
+ *******************************************************************************/
+
+package org.eclipse.cdt.lsp.clangd;
+
+import org.eclipse.cdt.core.CCorePlugin;
+import org.eclipse.cdt.core.cdtvariables.CdtVariableException;
+import org.eclipse.cdt.core.settings.model.ICConfigurationDescription;
+
+/**
+ * Helper class to resolve macros in builder CWD
+ */
+public class MacroResolver {
+
+	public String resolveValue(String value, String nonexistentMacrosValue, String listDelimiter,
+			ICConfigurationDescription cfg) throws CdtVariableException {
+		return CCorePlugin.getDefault().getCdtVariableManager().resolveValue(value, nonexistentMacrosValue,
+				listDelimiter, cfg);
+	}
+
+}

bundles/org.eclipse.cdt.lsp.clangd/src/org/eclipse/cdt/lsp/internal/clangd/CProjectChangeMonitor.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2023 Bachmann electronic GmbH and others.
+ * Copyright (c) 2024 Bachmann electronic GmbH and others.
  *
  * This program and the accompanying materials are made
  * available under the terms of the Eclipse Public License 2.0
@@ -9,69 +9,31 @@
  *
  * Contributors:
  * Gesa Hentschke (Bachmann electronic GmbH) - initial implementation
- * Alexander Fedorov (ArSysOp) - use Platform for logging
  *******************************************************************************/
 
 package org.eclipse.cdt.lsp.internal.clangd;
 
-import java.io.IOException;
-import java.util.Optional;
-
 import org.eclipse.cdt.core.CCorePlugin;
 import org.eclipse.cdt.core.settings.model.CProjectDescriptionEvent;
-import org.eclipse.cdt.core.settings.model.ICConfigurationDescription;
-import org.eclipse.cdt.core.settings.model.ICProjectDescription;
 import org.eclipse.cdt.core.settings.model.ICProjectDescriptionListener;
-import org.eclipse.cdt.lsp.LspPlugin;
-import org.eclipse.cdt.lsp.LspUtils;
-import org.eclipse.cdt.lsp.internal.clangd.editor.LspEditorUiMessages;
-import org.eclipse.cdt.lsp.internal.clangd.editor.ClangdPlugin;
-import org.eclipse.core.resources.IProject;
-import org.eclipse.core.runtime.CoreException;
-import org.eclipse.core.runtime.IStatus;
-import org.eclipse.core.runtime.Platform;
-import org.eclipse.core.runtime.Status;
-import org.yaml.snakeyaml.scanner.ScannerException;
+import org.eclipse.cdt.lsp.clangd.ClangdCProjectDescriptionListener;
+import org.eclipse.cdt.lsp.clangd.MacroResolver;
+import org.eclipse.core.runtime.ServiceCaller;
 
+/**
+ * This monitor listens to C project description changes.
+ */
 public class CProjectChangeMonitor {
+	MacroResolver macroResolver = new MacroResolver();
+
+	private final ServiceCaller<ClangdCProjectDescriptionListener> clangdListener = new ServiceCaller<>(getClass(),
+			ClangdCProjectDescriptionListener.class);
 
 	private final ICProjectDescriptionListener listener = new ICProjectDescriptionListener() {
 
 		@Override
 		public void handleEvent(CProjectDescriptionEvent event) {
-			ICProjectDescription newCProjectDecription = event.getNewCProjectDescription();
-			if (newCProjectDecription != null) {
-				IProject project = event.getProject();
-				boolean isEnabled = Optional.ofNullable(LspPlugin.getDefault())
-						.map(LspPlugin::getCLanguageServerProvider).map(provider -> provider.isEnabledFor(project))
-						.orElse(Boolean.FALSE);
-				if (project != null && isEnabled) {
-					ICConfigurationDescription newConfig = newCProjectDecription.getDefaultSettingConfiguration();
-					var cwdBuilder = newConfig.getBuildSetting().getBuilderCWD();
-					if (cwdBuilder != null) {
-						try {
-							var cwdString = CCorePlugin.getDefault().getCdtVariableManager()
-									.resolveValue(cwdBuilder.toOSString(), "", null, newConfig);
-							var projectLocation = project.getLocation().addTrailingSeparator().toOSString();
-							var databasePath = cwdString.replace(projectLocation, "");
-							try {
-								ClangdConfigurationManager.setCompilationDatabase(project, databasePath);
-							} catch (ScannerException e) {
-								var status = new Status(IStatus.ERROR, ClangdPlugin.PLUGIN_ID, e.getMessage());
-								var configFile = ClangdConfigurationManager.CLANGD_CONFIG_FILE_NAME;
-								LspUtils.showErrorMessage(LspEditorUiMessages.CProjectChangeMonitor_yaml_scanner_error,
-										LspEditorUiMessages.CProjectChangeMonitor_yaml_scanner_error_message
-												+ projectLocation + configFile,
-										status);
-							}
-						} catch (CoreException e) {
-							Platform.getLog(getClass()).log(e.getStatus());
-						} catch (IOException e) {
-							Platform.getLog(getClass()).error(e.getMessage(), e);
-						}
-					}
-				}
-			}
+			clangdListener.call(c -> c.handleEvent(event, macroResolver));
 		}
 
 	};

bundles/org.eclipse.cdt.lsp.clangd/src/org/eclipse/cdt/lsp/internal/clangd/ClangdConfigFileChecker.java

@@ -0,0 +1,127 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Bachmann electronic GmbH and others.
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Gesa Hentschke (Bachmann electronic GmbH) - initial implementation
+ *******************************************************************************/
+
+package org.eclipse.cdt.lsp.internal.clangd;
+
+import java.io.IOException;
+
+import org.eclipse.cdt.lsp.internal.clangd.editor.ClangdPlugin;
+import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IMarker;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.Platform;
+import org.yaml.snakeyaml.Yaml;
+import org.yaml.snakeyaml.error.MarkedYAMLException;
+
+/**
+ * Checks the <code>.clangd</code> file for syntax errors and notifies the user via error markers in the file and Problems view.
+ */
+public class ClangdConfigFileChecker {
+	public static final String CLANGD_MARKER = ClangdPlugin.PLUGIN_ID + ".config.marker"; //$NON-NLS-1$
+
+	/**
+	 * Checks if the .clangd file contains valid yaml syntax. Adds error marker to the file if not.
+	 * @param configFile
+	 */
+	public void checkConfigFile(IFile configFile) {
+		if (!configFile.exists()) {
+			return;
+		}
+		Yaml yaml = new Yaml();
+		try (var inputStream = configFile.getContents()) {
+			try {
+				removeMarkerFromClangdConfig(configFile);
+				//throws ScannerException and ParserException:
+				yaml.load(inputStream);
+			} catch (MarkedYAMLException yamlException) {
+				// re-read the file, because the buffer which comes along with MarkedYAMLException is limited to ~800 bytes.
+				try (var reReadStream = configFile.getContents()) {
+					addMarkerToClangdConfig(configFile, yamlException, reReadStream.readAllBytes());
+				}
+			} catch (Exception exception) {
+				//log unexpected exception:
+				Platform.getLog(getClass()).error("Expected MarkedYAMLException, but was: " + exception.getMessage(), //$NON-NLS-1$
+						exception);
+			}
+		} catch (IOException | CoreException e) {
+			Platform.getLog(getClass()).error(e.getMessage(), e);
+		}
+	}
+
+	private void addMarkerToClangdConfig(IFile configFile, MarkedYAMLException yamlException, byte[] buffer) {
+		try {
+			var configMarker = parseYamlException(yamlException, buffer);
+			var marker = configFile.createMarker(CLANGD_MARKER);
+			marker.setAttribute(IMarker.MESSAGE, configMarker.message);
+			marker.setAttribute(IMarker.SEVERITY, IMarker.SEVERITY_ERROR);
+			marker.setAttribute(IMarker.LINE_NUMBER, configMarker.line);
+			marker.setAttribute(IMarker.CHAR_START, configMarker.charStart);
+			marker.setAttribute(IMarker.CHAR_END, configMarker.charEnd);
+		} catch (CoreException core) {
+			Platform.getLog(getClass()).log(core.getStatus());
+		}
+	}
+
+	private void removeMarkerFromClangdConfig(IFile configFile) {
+		try {
+			configFile.deleteMarkers(CLANGD_MARKER, false, IResource.DEPTH_ZERO);
+		} catch (CoreException e) {
+			Platform.getLog(getClass()).log(e.getStatus());
+		}
+	}
+
+	private class ClangdConfigMarker {
+		public String message;
+		public int line = 1;
+		public int charStart = -1;
+		public int charEnd = -1;
+	}
+
+	/**
+	 * Fetch line and char position information from exception to create a marker for the .clangd file.
+	 * @param exception
+	 * @param file
+	 * @return
+	 */
+	private ClangdConfigMarker parseYamlException(MarkedYAMLException exception, byte[] buffer) {
+		var marker = new ClangdConfigMarker();
+		var context = exception.getContext();
+		marker.message = context != null ? context + " " + exception.getProblem() : exception.getProblem(); //$NON-NLS-1$
+		var problemMark = exception.getProblemMark();
+		if (problemMark == null) {
+			return marker;
+		}
+		marker.line = problemMark.getLine() + 1; //getLine() is zero based, IMarker wants 1-based
+		int index = problemMark.getIndex();
+		if (index == buffer.length) {
+			// When index == buffer.length() the marker index points to the non visible
+			// \r or \n character and the marker is not displayed in the editor.
+			// Or, even worse, there is no next line and index + 1 would be > buffer.length
+			// Therefore we have to find the last visible char:
+			index = getIndexOfLastVisibleChar(buffer);
+		}
+		marker.charStart = index;
+		marker.charEnd = index + 1;
+		return marker;
+	}
+
+	private int getIndexOfLastVisibleChar(byte[] buffer) {
+		for (int i = buffer.length - 1; i >= 0; i--) {
+			if ('\r' != ((char) buffer[i]) && '\n' != ((char) buffer[i])) {
+				return i;
+			}
+		}
+		return Math.max(0, buffer.length - 2);
+	}
+}

bundles/org.eclipse.cdt.lsp.clangd/src/org/eclipse/cdt/lsp/internal/clangd/ClangdConfigFileMonitor.java

@@ -0,0 +1,87 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Bachmann electronic GmbH and others.
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Gesa Hentschke (Bachmann electronic GmbH) - initial implementation
+ *******************************************************************************/
+
+package org.eclipse.cdt.lsp.internal.clangd;
+
+import java.util.concurrent.ConcurrentLinkedQueue;
+
+import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IResourceChangeEvent;
+import org.eclipse.core.resources.IResourceChangeListener;
+import org.eclipse.core.resources.IResourceDelta;
+import org.eclipse.core.resources.IWorkspace;
+import org.eclipse.core.resources.WorkspaceJob;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Platform;
+import org.eclipse.core.runtime.Status;
+
+/**
+ * Monitor changes in <code>.clangd</code> files in the workspace and triggers a yaml checker
+ * to add error markers to the <code>.clangd</code> file when the edits causes yaml loader failures.
+ */
+public class ClangdConfigFileMonitor {
+	private static final String CLANGD_CONFIG_FILE = ".clangd"; //$NON-NLS-1$
+	private final ConcurrentLinkedQueue<IFile> pendingFiles = new ConcurrentLinkedQueue<>();
+	private final IWorkspace workspace;
+	private final ClangdConfigFileChecker checker = new ClangdConfigFileChecker();
+
+	private final IResourceChangeListener listener = new IResourceChangeListener() {
+		@Override
+		public void resourceChanged(IResourceChangeEvent event) {
+			if (event.getDelta() != null && event.getType() == IResourceChangeEvent.POST_CHANGE) {
+				try {
+					event.getDelta().accept(delta -> {
+						if ((delta.getKind() == IResourceDelta.ADDED
+								|| (delta.getFlags() & IResourceDelta.CONTENT) != 0)
+								&& CLANGD_CONFIG_FILE.equals(delta.getResource().getName())) {
+							if (delta.getResource() instanceof IFile file) {
+								pendingFiles.add(file);
+								checkJob.schedule(100);
+							}
+						}
+						return true;
+					});
+				} catch (CoreException e) {
+					Platform.getLog(getClass()).log(e.getStatus());
+				}
+			}
+		}
+	};
+
+	public ClangdConfigFileMonitor(IWorkspace workspace) {
+		this.workspace = workspace;
+	}
+
+	private final WorkspaceJob checkJob = new WorkspaceJob("Check .clangd file") { //$NON-NLS-1$
+
+		@Override
+		public IStatus runInWorkspace(IProgressMonitor monitor) throws CoreException {
+			while (pendingFiles.peek() != null) {
+				checker.checkConfigFile(pendingFiles.poll());
+			}
+			return Status.OK_STATUS;
+		}
+
+	};
+
+	public ClangdConfigFileMonitor start() {
+		workspace.addResourceChangeListener(listener);
+		return this;
+	}
+
+	public void stop() {
+		workspace.removeResourceChangeListener(listener);
+	}
+}

bundles/org.eclipse.cdt.lsp.clangd/src/org/eclipse/cdt/lsp/internal/clangd/ClangdLanguageServerProvider.java

@@ -19,14 +19,17 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 import org.eclipse.cdt.lsp.clangd.ClangdConfiguration;
 import org.eclipse.cdt.lsp.clangd.ClangdFallbackFlags;
 import org.eclipse.cdt.lsp.editor.Configuration;
 import org.eclipse.cdt.lsp.editor.LanguageServerEnable;
 import org.eclipse.cdt.lsp.server.ICLanguageServerProvider;
 import org.eclipse.core.resources.IProject;
+import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.ServiceCaller;
+import org.eclipse.core.variables.VariablesPlugin;
 
 public final class ClangdLanguageServerProvider implements ICLanguageServerProvider {
 
@@ -47,10 +50,19 @@ public Object getInitializationOptions(URI rootUri) {
 	@Override
 	public List<String> getCommands(URI rootUri) {
 		List<String> result = new ArrayList<>();
-		configuration.call(c -> result.addAll(c.commands(rootUri)));
+		configuration.call(c -> result.addAll(c.commands(rootUri).stream()
+				.map(ClangdLanguageServerProvider::resolveVariables).collect(Collectors.toList())));
 		return result;
 	}
 
+	private static String resolveVariables(String cmd) {
+		try {
+			return VariablesPlugin.getDefault().getStringVariableManager().performStringSubstitution(cmd);
+		} catch (CoreException e) {
+			return cmd;
+		}
+	}
+
 	@Override
 	public boolean isEnabledFor(IProject project) {
 		boolean[] enabled = new boolean[1];

bundles/org.eclipse.cdt.lsp.clangd/src/org/eclipse/cdt/lsp/internal/clangd/editor/ClangdConfigurationPage.java

@@ -14,6 +14,8 @@
 
 package org.eclipse.cdt.lsp.internal.clangd.editor;
 
+import java.io.IOException;
+
 import org.eclipse.cdt.lsp.LspUtils;
 import org.eclipse.cdt.lsp.clangd.ClangdConfiguration;
 import org.eclipse.cdt.lsp.clangd.ClangdMetadata;
@@ -22,11 +24,13 @@
 import org.eclipse.cdt.lsp.editor.ConfigurationArea;
 import org.eclipse.cdt.lsp.editor.EditorConfigurationPage;
 import org.eclipse.core.resources.IWorkspace;
+import org.eclipse.core.runtime.Status;
 import org.eclipse.jface.dialogs.IDialogConstants;
 import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.ui.IWorkbench;
 import org.eclipse.ui.PlatformUI;
+import org.eclipse.ui.statushandlers.StatusManager;
 
 public final class ClangdConfigurationPage extends EditorConfigurationPage {
 
@@ -93,7 +97,13 @@ private void openRestartDialog() {
 				new String[] { IDialogConstants.NO_LABEL, LspEditorUiMessages.LspEditorPreferencePage_restart_button },
 				1);
 		if (dialog.open() == 1) {
-			LspUtils.getLanguageServers().forEach(w -> w.stop());
+			LspUtils.getLanguageServers().forEach(w -> {
+				try {
+					w.restart();
+				} catch (IOException e) {
+					StatusManager.getManager().handle(Status.error("Could not restart language servers", e)); //$NON-NLS-1$
+				}
+			});
 		}
 	}
 

bundles/org.eclipse.cdt.lsp.clangd/src/org/eclipse/cdt/lsp/internal/clangd/editor/ClangdPlugin.java

@@ -15,6 +15,7 @@
 package org.eclipse.cdt.lsp.internal.clangd.editor;
 
 import org.eclipse.cdt.lsp.internal.clangd.CProjectChangeMonitor;
+import org.eclipse.cdt.lsp.internal.clangd.ClangdConfigFileMonitor;
 import org.eclipse.core.resources.IWorkspace;
 import org.eclipse.ui.plugin.AbstractUIPlugin;
 import org.osgi.framework.BundleContext;
@@ -27,6 +28,7 @@ public class ClangdPlugin extends AbstractUIPlugin {
 	private IWorkspace workspace;
 	private CompileCommandsMonitor compileCommandsMonitor;
 	private CProjectChangeMonitor cProjectChangeMonitor;
+	private ClangdConfigFileMonitor configFileMonitor;
 
 	// The plug-in ID
 	public static final String PLUGIN_ID = "org.eclipse.cdt.lsp.clangd"; //$NON-NLS-1$
@@ -49,13 +51,15 @@ public void start(BundleContext context) throws Exception {
 		workspace = workspaceTracker.getService();
 		compileCommandsMonitor = new CompileCommandsMonitor(workspace).start();
 		cProjectChangeMonitor = new CProjectChangeMonitor().start();
+		configFileMonitor = new ClangdConfigFileMonitor(workspace).start();
 	}
 
 	@Override
 	public void stop(BundleContext context) throws Exception {
 		plugin = null;
 		compileCommandsMonitor.stop();
 		cProjectChangeMonitor.stop();
+		configFileMonitor.stop();
 		super.stop(context);
 	}
 

bundles/org.eclipse.cdt.lsp.clangd/src/org/eclipse/cdt/lsp/internal/clangd/editor/CompileCommandsMonitor.java

@@ -13,9 +13,14 @@
 
 package org.eclipse.cdt.lsp.internal.clangd.editor;
 
+import java.io.IOException;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Set;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
 import java.util.stream.Stream;
 
 import org.eclipse.cdt.lsp.LspUtils;
@@ -28,45 +33,83 @@
 import org.eclipse.core.resources.IWorkspace;
 import org.eclipse.core.runtime.Adapters;
 import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Platform;
-import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.core.runtime.Status;
 import org.eclipse.ui.IEditorPart;
-import org.eclipse.ui.IReusableEditor;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.IWorkbenchWindow;
 import org.eclipse.ui.PlatformUI;
-import org.eclipse.ui.progress.UIJob;
 import org.eclipse.ui.statushandlers.StatusManager;
 
 /**
  * Detects changes (add/delete/content) of JSON Compilation Database Format
  * Specification files ({@value #CDBF_SPECIFICATION_JSON_FILE}) in the
- * {@link IWorkspace workspace} and
- * {@link CompileCommandsMonitor#refreshEditor(IEditorPart) refreshes} open
- * editors if their {@link IEditorPart#getEditorInput()} is affected.
+ * {@link IWorkspace workspace} and {@link #restartLanguageServers() restarts
+ * the language servers} if any cpp file from the affected projects is  open
+ * in an editor.
  */
 public class CompileCommandsMonitor {
-	private static final String CDBF_SPECIFICATION_JSON_FILE = "compile_commands.json";
+	private static final String CDBF_SPECIFICATION_JSON_FILE = "compile_commands.json"; //$NON-NLS-1$
+
+	private static final long DEBOUNCE_DELAY = 2000; // ms
+
+	private final IWorkspace workspace;
+
+	/**
+	 * Utility class for postponing the execution of a {@link Runnable} to avoid
+	 * unnecessary or frequent invocation.
+	 */
+	private static final class Debouncer {
+		private long debounceDelay;
+		private ScheduledExecutorService scheduler;
+		private ScheduledFuture<?> debounceTimer;
+
+		public Debouncer(long debounceDelay) {
+			this.debounceDelay = debounceDelay;
+		}
+
+		public void run(Runnable runnable) {
+			if (debounceTimer != null && !debounceTimer.isDone()) {
+				debounceTimer.cancel(true);
+			}
+
+			debounceTimer = scheduler.schedule(runnable, debounceDelay, TimeUnit.MILLISECONDS);
+		}
+
+		public void start() {
+			scheduler = Executors.newScheduledThreadPool(1);
+		}
+
+		public void stop() {
+			scheduler.shutdown();
+		}
+	}
+
+	private final Debouncer debouncer;
 
 	private final IResourceChangeListener listener = new IResourceChangeListener() {
 		@Override
 		public void resourceChanged(IResourceChangeEvent event) {
-			Set<IProject> projects = collectAffectedProjects(event);
-
-			if (!projects.isEmpty()) {
-				// collect all open editors which have cpp files as input and refresh them
-				Arrays.stream(PlatformUI.getWorkbench().getWorkbenchWindows()).map(IWorkbenchWindow::getPages)
-						.flatMap(Arrays::stream).map(IWorkbenchPage::getEditorReferences).flatMap(Arrays::stream)
-						.flatMap(ref -> Stream.ofNullable(ref.getEditor(false))).forEach(editor -> {
-							IFile file = Adapters.adapt(editor.getEditorInput(), IFile.class);
-
-							if (isCppFile(file) && projects.contains(file.getProject())) {
-								refreshEditor(editor, file);
-							}
-						});
+			Set<IProject> affectedProjects = collectAffectedProjects(event);
+
+			if (!affectedProjects.isEmpty()) {
+				if (getEditors().map(editor -> Adapters.adapt(editor.getEditorInput(), IFile.class))
+						.anyMatch(file -> isCppFile(file) && affectedProjects.contains(file.getProject()))) {
+					debouncer.run(() -> restartLanguageServers());
+				}
 			}
 		}
 
+		/**
+		 * Returns the editors in workbench without restoring them
+		 */
+		private Stream<IEditorPart> getEditors() {
+			return Arrays.stream(PlatformUI.getWorkbench().getWorkbenchWindows()).map(IWorkbenchWindow::getPages)
+					.flatMap(Arrays::stream).map(IWorkbenchPage::getEditorReferences).flatMap(Arrays::stream)
+					.flatMap(ref -> Stream.ofNullable(ref.getEditor(false)));
+		}
+
 		private boolean isCppFile(IResource resource) {
 			if (resource instanceof IFile) {
 				var contentTypes = Platform.getContentTypeManager().findContentTypesFor(((IFile) resource).getName());
@@ -103,41 +146,31 @@ private Set<IProject> collectAffectedProjects(IResourceChangeEvent event) {
 		}
 	};
 
-	private final IWorkspace workspace;
-
 	public CompileCommandsMonitor(IWorkspace workspace) {
 		this.workspace = workspace;
+		this.debouncer = new Debouncer(DEBOUNCE_DELAY);
+	}
+
+	protected void restartLanguageServers() {
+		LspUtils.getLanguageServers().forEach(w -> {
+			try {
+				w.restart();
+			} catch (IOException e) {
+				StatusManager.getManager().handle(
+						new Status(IStatus.ERROR, ClangdPlugin.PLUGIN_ID, "Could not restart language servers"),
+						StatusManager.LOG);
+			}
+		});
 	}
 
 	public CompileCommandsMonitor start() {
 		workspace.addResourceChangeListener(listener);
+		debouncer.start();
 		return this;
 	}
 
 	public void stop() {
 		workspace.removeResourceChangeListener(listener);
-	}
-
-	private static void refreshEditor(IEditorPart editor, IFile file) {
-		ITextViewer textViewer = Adapters.adapt(editor, ITextViewer.class);
-
-		// Notify clangd about the file change --> doesn't seem to work
-		//		org.eclipse.lsp4e.LanguageServers.forDocument(textViewer.getDocument()).computeFirst(server -> {
-		//			server.getWorkspaceService()
-		//					.didChangeWatchedFiles(new DidChangeWatchedFilesParams(Arrays.asList(new FileEvent(
-		//							file.getProject().getFile(CDBF_SPECIFICATION_JSON_FILE).getLocationURI().toASCIIString(),
-		//							FileChangeType.Changed))));
-		//			return new CompletableFuture<>();
-		//		});
-
-		// Refresh the editors after 5 seconds -> see https://reviews.llvm.org/D92663
-		UIJob.create("Refresh Editors", monitor -> {
-			if (textViewer.getDocument() == null)
-				return;
-			int rangeOffset = textViewer.getTopIndexStartOffset();
-			int rangeLength = textViewer.getBottomIndexEndOffset() - rangeOffset;
-			editor.getSite().getPage().reuseEditor((IReusableEditor) editor, editor.getEditorInput());
-			textViewer.revealRange(rangeOffset, rangeLength);
-		}).schedule(5000);
+		debouncer.stop();
 	}
 }

bundles/org.eclipse.cdt.lsp.clangd/src/org/eclipse/cdt/lsp/internal/clangd/editor/LspEditorUiMessages.java

@@ -46,7 +46,4 @@ public class LspEditorUiMessages extends NLS {
 	public static String LspEditorPreferencePage_completion_default;
 	public static String LspEditorPreferencePage_select_clangd_executable;
 
-	public static String CProjectChangeMonitor_yaml_scanner_error;
-	public static String CProjectChangeMonitor_yaml_scanner_error_message;
-
 }

bundles/org.eclipse.cdt.lsp.clangd/src/org/eclipse/cdt/lsp/internal/clangd/editor/LspEditorUiMessages.properties

@@ -33,6 +33,3 @@ LspEditorPreferencePage_completion_detailed=Detailed
 LspEditorPreferencePage_completion_bundled=Bundled
 LspEditorPreferencePage_completion_default=Default
 LspEditorPreferencePage_select_clangd_executable=Select clangd executable
-
-CProjectChangeMonitor_yaml_scanner_error=Yaml Scanner Error
-CProjectChangeMonitor_yaml_scanner_error_message=Error while reading:

bundles/org.eclipse.cdt.lsp.test/src/org/eclipse/cdt/lsp/test/LspUtilsTest.java

@@ -26,11 +26,6 @@ void testIsCContentType_EmptyId() {
 		assertTrue(!LspUtils.isCContentType(""));
 	}
 
-	@Test
-	void testIsCContentType_CppContentTypeFromTM4E() {
-		assertTrue(LspUtils.isCContentType("lng.cpp"));
-	}
-
 	@Test
 	void testIsCContentType_CONTENT_TYPE_CSOURCE() {
 		assertTrue(LspUtils.isCContentType(CCorePlugin.CONTENT_TYPE_CSOURCE));

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

@@ -7,12 +7,14 @@ Export-Package: org.eclipse.cdt.lsp,
  org.eclipse.cdt.lsp.editor,
  org.eclipse.cdt.lsp.server,
  org.eclipse.cdt.lsp.server.enable,
- org.eclipse.cdt.lsp.services
+ org.eclipse.cdt.lsp.services,
+ org.eclipse.cdt.lsp.services.ast,
+ org.eclipse.cdt.lsp.services.symbolinfo
 Bundle-Activator: org.eclipse.cdt.lsp.LspPlugin
 Bundle-Vendor: %Bundle-Vendor
 Require-Bundle: org.eclipse.ui,
  org.eclipse.core.runtime,
- org.eclipse.lsp4e;bundle-version="0.17.1",
+ org.eclipse.lsp4e;bundle-version="0.17.3",
  org.eclipse.tm4e.ui,
  org.eclipse.tm4e.languageconfiguration,
  org.eclipse.ui.genericeditor,
@@ -29,12 +31,14 @@ Require-Bundle: org.eclipse.ui,
  org.eclipse.lsp4j,
  org.eclipse.lsp4j.jsonrpc,
  org.eclipse.cdt.codan.core,
- org.eclipse.cdt.debug.ui
+ org.eclipse.cdt.debug.ui,
+ org.eclipse.ui.workbench.texteditor
 Bundle-RequiredExecutionEnvironment: JavaSE-17
 Automatic-Module-Name: org.eclipse.cdt.lsp
 Bundle-ActivationPolicy: lazy
 Service-Component: OSGI-INF/org.eclipse.cdt.lsp.editor.BuiltinEditorOptionsDefault.xml,
  OSGI-INF/org.eclipse.cdt.lsp.editor.DefaultConfigurationVisibility.xml,
  OSGI-INF/org.eclipse.cdt.lsp.editor.EditorConfigurationAccess.xml,
  OSGI-INF/org.eclipse.cdt.lsp.editor.EditorMetadataDefaults.xml,
+ OSGI-INF/org.eclipse.cdt.lsp.editor.format.FormatOnSave.xml,
  OSGI-INF/org.eclipse.cdt.lsp.internal.InitialFileManager.xml

bundles/org.eclipse.cdt.lsp/OSGI-INF/l10n/bundle.properties

@@ -23,6 +23,7 @@ which is available at https://www.eclipse.org/legal/epl-2.0/\n\
 \n\
 SPDX-License-Identifier: EPL-2.0\n\
 
+SaveActionsPreferencePage.name=Save Actions
 EditorPreferencePage.name=Editor (LSP)
 CEditor.name=C/C++ Editor (LSP)
 Server.name=C/C++ Language Server

bundles/org.eclipse.cdt.lsp/OSGI-INF/org.eclipse.cdt.lsp.editor.format.FormatOnSave.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.3.0" name="org.eclipse.cdt.lsp.editor.format.FormatOnSave">
+   <property name="serverDefinitionId" type="String" value="org.eclipse.cdt.lsp.server"/>
+   <service>
+      <provide interface="org.eclipse.lsp4e.format.IFormatRegionsProvider"/>
+   </service>
+   <reference cardinality="1..1" field="configuration" interface="org.eclipse.cdt.lsp.editor.Configuration" name="configuration"/>
+   <implementation class="org.eclipse.cdt.lsp.editor.format.FormatOnSave"/>
+</scr:component>

bundles/org.eclipse.cdt.lsp/plugin.xml

@@ -33,16 +33,7 @@
          <contentTypeBinding
                contentTypeId="org.eclipse.cdt.core.cxxSource">
          </contentTypeBinding>
-         <contentTypeBinding
-               contentTypeId="lng.cpp"> <!-- // TODO: The content type definition from TM4E "lng.cpp" can be omitted here if either https://github.com/eclipse-cdt/cdt/pull/310 or 
-		// https://github.com/eclipse/tm4e/pull/500 has been merged. --> 
-         </contentTypeBinding>       
       </editor>
-      <editorContentTypeBinding
-            contentTypeId="lng.cpp"
-            editorId="org.eclipse.cdt.ui.editor.CEditor"> <!-- // TODO: The content type definition from TM4E "lng.cpp" can be omitted here if either https://github.com/eclipse-cdt/cdt/pull/310 or 
-		// https://github.com/eclipse/tm4e/pull/500 has been merged. --> 
-      </editorContentTypeBinding>
    </extension>
    <extension
          point="org.eclipse.lsp4e.languageServer">
@@ -224,6 +215,13 @@
             properties="hasLanguageServer"
             type="java.lang.Object">
       </propertyTester>
+      <propertyTester
+            class="org.eclipse.cdt.lsp.internal.editor.SpellingEnabled"
+            id="org.eclipse.cdt.lsp.editor.spelling.EnabledTester"
+            namespace="org.eclipse.cdt.lsp.editor.spelling"
+            properties="enabled"
+            type="java.lang.Object">
+      </propertyTester>
    </extension>
    <extension
          point="org.eclipse.core.expressions.definitions">
@@ -277,6 +275,14 @@
             id="org.eclipse.cdt.lsp.editor.preferencePage"
             name="%EditorPreferencePage.name">
       </page>
+      <page
+	        name="%SaveActionsPreferencePage.name"
+	        category="org.eclipse.cdt.lsp.editor.preferencePage"
+	        class="org.eclipse.cdt.lsp.editor.SaveActionsConfigurationPage"
+	        id="org.eclipse.cdt.lsp.editor.SaveActionsPreferencePage">
+	      <keywordReference id="org.eclipse.cdt.ui.saveactions"/>
+	      <keywordReference id="org.eclipse.cdt.ui.common"/>
+      </page>      
    </extension>
    <extension
          point="org.eclipse.ui.propertyPages">
@@ -295,6 +301,26 @@
             </adapt>
          </enabledWhen>
       </page>
+      <page
+            category="org.eclipse.cdt.lsp.editor.propertyPage"
+            class="org.eclipse.cdt.lsp.editor.SaveActionsConfigurationPage"
+            id="org.eclipse.cdt.lsp.editor.SaveActionsPropertyPage"
+            name="%SaveActionsPreferencePage.name">
+          <keywordReference id="org.eclipse.cdt.ui.saveactions"/>
+	      <keywordReference id="org.eclipse.cdt.ui.common"/>
+      </page>      
    </extension>
+   <extension
+         point="org.eclipse.ui.genericeditor.reconcilers">
+      <reconciler
+            class="org.eclipse.cdt.lsp.internal.editor.CSpellingReconciler"
+            contentType="org.eclipse.core.runtime.text">
+         <enabledWhen>
+            <test
+                  property="org.eclipse.cdt.lsp.editor.spelling.enabled">
+            </test>
+         </enabledWhen>
+      </reconciler>
+   </extension>  
 </plugin>
 

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/LspUtils.java

@@ -21,22 +21,16 @@
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IWorkspace;
-import org.eclipse.core.runtime.IProgressMonitor;
-import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.ServiceCaller;
-import org.eclipse.core.runtime.Status;
-import org.eclipse.jface.dialogs.ErrorDialog;
 import org.eclipse.lsp4e.LanguageServerWrapper;
 import org.eclipse.lsp4e.LanguageServiceAccessor;
-import org.eclipse.swt.widgets.Shell;
 import org.eclipse.ui.IEditorInput;
 import org.eclipse.ui.IEditorReference;
 import org.eclipse.ui.IURIEditorInput;
 import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.part.FileEditorInput;
-import org.eclipse.ui.progress.UIJob;
 
 public class LspUtils {
 
@@ -47,35 +41,7 @@ public class LspUtils {
 	 * @return {@code true} if C/C++ content type
 	 */
 	public static boolean isCContentType(String id) {
-		// TODO: The content type definition from TM4E "lng.cpp" can be omitted if either https://github.com/eclipse-cdt/cdt/pull/310 or
-		// https://github.com/eclipse/tm4e/pull/500 has been merged.
-		return (id.startsWith("org.eclipse.cdt.core.c") && (id.endsWith("Source") || id.endsWith("Header"))) //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
-				|| "lng.cpp".equals(id); //$NON-NLS-1$
-	}
-
-	/**
-	 * Show error dialog to user
-	 * @param title
-	 * @param errorText
-	 * @param status
-	 */
-	public static void showErrorMessage(final String title, final String errorText, final Status status) {
-		UIJob job = new UIJob("LSP Utils") //$NON-NLS-1$
-		{
-			@Override
-			public IStatus runInUIThread(IProgressMonitor monitor) {
-				ErrorDialog.openError(getActiveShell(), title, errorText, status);
-				return Status.OK_STATUS;
-			}
-		};
-		job.setSystem(true);
-		job.schedule();
-	}
-
-	private static Shell getActiveShell() {
-		if (PlatformUI.getWorkbench() != null && PlatformUI.getWorkbench().getActiveWorkbenchWindow() != null)
-			return PlatformUI.getWorkbench().getActiveWorkbenchWindow().getShell();
-		return null;
+		return (id.startsWith("org.eclipse.cdt.core.c") && (id.endsWith("Source") || id.endsWith("Header"))); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 	}
 
 	public static boolean isFileOpenedInLspEditor(URI uri) {

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/editor/BuiltinEditorOptionsDefault.java

@@ -22,4 +22,19 @@ public boolean preferLspEditor() {
 		return false;
 	}
 
+	@Override
+	public boolean formatOnSave() {
+		return false;
+	}
+
+	@Override
+	public boolean formatAllLines() {
+		return true;
+	}
+
+	@Override
+	public boolean formatEditedLines() {
+		return false;
+	}
+
 }

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/editor/EditorConfigurationPage.java

@@ -162,10 +162,25 @@ private Control createPreferenceContent(Composite parent, boolean isProjectScope
 		Composite composite = new Composite(parent, SWT.NONE);
 		composite.setLayout(GridLayoutFactory.fillDefaults().create());
 		composite.setFont(parent.getFont());
+		if (!isProjectScope) {
+			createSpellingPreferencesLink(composite);
+			Label line = new Label(composite, SWT.SEPARATOR | SWT.HORIZONTAL);
+			line.setLayoutData(new GridData(GridData.FILL, GridData.FILL, true, false, 2, 1));
+		}
 		area = getConfigurationArea(composite, isProjectScope);
 		return composite;
 	}
 
+	private Control createSpellingPreferencesLink(Composite parent) {
+		Link link = new Link(parent, SWT.NONE);
+		link.setText(LspUiMessages.LspEditorConfigurationPage_spelling_link);
+		link.addListener(SWT.Selection,
+				event -> PreferencesUtil.createPreferenceDialogOn(getShell(), event.text, null, null));
+		link.setToolTipText(LspUiMessages.LspEditorConfigurationPage_spelling_link_tooltip);
+		link.setLayoutData(new GridData(SWT.FILL, SWT.BEGINNING, true, false));
+		return link;
+	}
+
 	protected void refreshWidgets(Object options) {
 		setErrorMessage(null);
 		area.load(options, useProjectSettings() || !projectScope().isPresent());

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/editor/EditorMetadata.java

@@ -25,4 +25,30 @@ public interface EditorMetadata {
 	 */
 	PreferenceMetadata<Boolean> preferLspEditor();
 
+	/**
+	 * Returns the metadata for the "Format source code" option, must not return <code>null</code>.
+	 *
+	 * @return the metadata for the "Format source code" option
+	 *
+	 * @see EditorOptions#formatOnSave()
+	 */
+	PreferenceMetadata<Boolean> formatOnSave();
+
+	/**
+	 * Returns the metadata for the "Format all lines" option, must not return <code>null</code>.
+	 *
+	 * @return the metadata for the "Format all lines" option
+	 *
+	 * @see EditorOptions#formatAllLines()
+	 */
+	PreferenceMetadata<Boolean> formatAllLines();
+
+	/**
+	 * Returns the metadata for the "Format edited lines" option, must not return <code>null</code>.
+	 *
+	 * @return the metadata for the "Format edited lines" option
+	 *
+	 * @see EditorOptions#formatEditedLines()
+	 */
+	PreferenceMetadata<Boolean> formatEditedLines();
 }

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/editor/EditorMetadataDefaults.java

@@ -32,4 +32,31 @@ public PreferenceMetadata<Boolean> preferLspEditor() {
 				LspUiMessages.LspEditorConfigurationPage_preferLspEditor_description);
 	}
 
+	@Override
+	public PreferenceMetadata<Boolean> formatOnSave() {
+		return new PreferenceMetadata<>(Boolean.class, //
+				"format_source", //$NON-NLS-1$
+				defaults.formatOnSave(), //
+				LspUiMessages.SaveActionsConfigurationPage_FormatSourceCode,
+				LspUiMessages.SaveActionsConfigurationPage_FormatSourceCode_description);
+	}
+
+	@Override
+	public PreferenceMetadata<Boolean> formatAllLines() {
+		return new PreferenceMetadata<>(Boolean.class, //
+				"format_all_lines", //$NON-NLS-1$
+				defaults.formatAllLines(), //
+				LspUiMessages.SaveActionsConfigurationPage_FormatAllLines,
+				LspUiMessages.SaveActionsConfigurationPage_FormatAllLines_description);
+	}
+
+	@Override
+	public PreferenceMetadata<Boolean> formatEditedLines() {
+		return new PreferenceMetadata<>(Boolean.class, //
+				"format_edited_lines", //$NON-NLS-1$
+				defaults.formatEditedLines(), //
+				LspUiMessages.SaveActionsConfigurationPage_FormatEditedLines,
+				LspUiMessages.SaveActionsConfigurationPage_FormatEditedLines_description);
+	}
+
 }

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/editor/EditorOptions.java

@@ -21,4 +21,25 @@ public interface EditorOptions {
 	 */
 	boolean preferLspEditor();
 
+	/**
+	 * Format source code on file save action
+	 *
+	 * @return if source code should be formatted on file save action
+	 */
+	boolean formatOnSave();
+
+	/**
+	 * Format all lines in source file
+	 *
+	 * @return if all lines should be formatted
+	 */
+	boolean formatAllLines();
+
+	/**
+	 * Format edited lines only
+	 *
+	 * @return if only edited lines should be formatted
+	 */
+	boolean formatEditedLines();
+
 }

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/editor/EditorPreferenceInitializer.java

@@ -28,6 +28,9 @@ private void initializeDefaults(Configuration configuration) {
 		EditorMetadata metadata = (EditorMetadata) configuration.metadata();
 		String qualifier = configuration.qualifier();
 		initializeBoolean(metadata.preferLspEditor(), qualifier);
+		initializeBoolean(metadata.formatOnSave(), qualifier);
+		initializeBoolean(metadata.formatAllLines(), qualifier);
+		initializeBoolean(metadata.formatEditedLines(), qualifier);
 	}
 
 	private void initializeBoolean(PreferenceMetadata<Boolean> preference, String qualifier) {

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/editor/EditorPreferredOptions.java

@@ -34,6 +34,21 @@ public boolean preferLspEditor() {
 		return booleanValue(metadata.preferLspEditor());
 	}
 
+	@Override
+	public boolean formatOnSave() {
+		return booleanValue(metadata.formatOnSave());
+	}
+
+	@Override
+	public boolean formatAllLines() {
+		return booleanValue(metadata.formatAllLines());
+	}
+
+	@Override
+	public boolean formatEditedLines() {
+		return booleanValue(metadata.formatEditedLines());
+	}
+
 	@Override
 	public boolean isEnabledFor(IProject project) {
 		if (enable != null) {

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/editor/SaveActionsConfigurationArea.java

@@ -0,0 +1,58 @@
+package org.eclipse.cdt.lsp.editor;
+
+import org.eclipse.core.runtime.preferences.IEclipsePreferences;
+import org.eclipse.core.runtime.preferences.OsgiPreferenceMetadataStore;
+import org.eclipse.jface.layout.GridLayoutFactory;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.events.SelectionAdapter;
+import org.eclipse.swt.events.SelectionEvent;
+import org.eclipse.swt.layout.GridData;
+import org.eclipse.swt.widgets.Button;
+import org.eclipse.swt.widgets.Composite;
+
+public class SaveActionsConfigurationArea extends ConfigurationArea {
+
+	private final Button format;
+	private final Button formatAll;
+	private final Button formatEdited;
+
+	public SaveActionsConfigurationArea(Composite parent, EditorMetadata metadata, boolean isProjectScope) {
+		super(1);
+		Composite composite = new Composite(parent, SWT.NONE);
+		composite.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
+		composite.setLayout(GridLayoutFactory.fillDefaults().numColumns(columns).create());
+
+		this.format = createButton(metadata.formatOnSave(), composite, SWT.CHECK, 0);
+		this.formatAll = createButton(metadata.formatAllLines(), composite, SWT.RADIO, 15);
+		this.formatEdited = createButton(metadata.formatEditedLines(), composite, SWT.RADIO, 15);
+
+		final SelectionAdapter formatListener = new SelectionAdapter() {
+			@Override
+			public void widgetSelected(SelectionEvent e) {
+				var selection = format.getSelection();
+				formatAll.setEnabled(selection);
+				formatEdited.setEnabled(selection);
+			}
+		};
+		this.format.addSelectionListener(formatListener);
+	}
+
+	@Override
+	public void load(Object options, boolean enable) {
+		if (options instanceof EditorOptions editorOptions) {
+			format.setSelection(editorOptions.formatOnSave());
+			formatAll.setSelection(editorOptions.formatAllLines());
+			formatEdited.setSelection(editorOptions.formatEditedLines());
+			format.setEnabled(enable);
+			formatAll.setEnabled(enable && format.getSelection());
+			formatEdited.setEnabled(enable && format.getSelection());
+		}
+	}
+
+	@Override
+	public void store(IEclipsePreferences prefs) {
+		OsgiPreferenceMetadataStore store = new OsgiPreferenceMetadataStore(prefs);
+		buttons.entrySet().forEach(e -> store.save(e.getValue().getSelection(), e.getKey()));
+	}
+
+}

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/editor/SaveActionsConfigurationPage.java

@@ -0,0 +1,26 @@
+package org.eclipse.cdt.lsp.editor;
+
+import org.eclipse.swt.widgets.Composite;
+
+public class SaveActionsConfigurationPage extends EditorConfigurationPage {
+	private final String id = "org.eclipse.cdt.lsp.editor.SaveActionsPreferencePage"; //$NON-NLS-1$
+
+	@Override
+	protected ConfigurationArea getConfigurationArea(Composite composite, boolean isProjectScope) {
+		return new SaveActionsConfigurationArea(composite, (EditorMetadata) configuration.metadata(), isProjectScope);
+	}
+
+	@Override
+	protected String getPreferenceId() {
+		return id;
+	}
+
+	@Override
+	protected boolean hasProjectSpecificOptions() {
+		return projectScope()//
+				.map(p -> p.getNode(configuration.qualifier()))//
+				.map(n -> n.get(((EditorMetadata) configuration.metadata()).formatAllLines().identifer(), null))//
+				.isPresent();
+	}
+
+}

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/editor/format/FormatOnSave.java

@@ -0,0 +1,48 @@
+/*******************************************************************************
+ * Copyright (c) 2023 Contributors to the Eclipse Foundation.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *   See git history
+ *******************************************************************************/
+
+package org.eclipse.cdt.lsp.editor.format;
+
+import org.eclipse.cdt.lsp.editor.Configuration;
+import org.eclipse.cdt.lsp.editor.EditorOptions;
+import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.IRegion;
+import org.eclipse.lsp4e.LSPEclipseUtils;
+import org.eclipse.lsp4e.format.IFormatRegionsProvider;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Reference;
+
+@Component(property = { "serverDefinitionId:String=org.eclipse.cdt.lsp.server" })
+public class FormatOnSave implements IFormatRegionsProvider {
+
+	@Reference
+	private Configuration configuration;
+
+	@Override
+	public IRegion[] getFormattingRegions(IDocument document) {
+		var file = LSPEclipseUtils.getFile(document);
+		if (file != null) {
+			var editorOptions = (EditorOptions) configuration.options(file);
+			if (editorOptions != null && editorOptions.formatOnSave()) {
+				if (editorOptions.formatAllLines()) {
+					return IFormatRegionsProvider.allLines(document);
+				}
+				if (editorOptions.formatEditedLines()) {
+					return IFormatRegionsProvider.calculateEditedLineRegions(document, new NullProgressMonitor());
+				}
+			}
+		}
+		return null;
+	}
+
+}

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/internal/editor/CSpellingReconcileStrategy.java

@@ -0,0 +1,25 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Bachmann electronic GmbH and others.
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Gesa Hentschke (Bachmann electronic GmbH) - initial implementation
+ *******************************************************************************/
+
+package org.eclipse.cdt.lsp.internal.editor;
+
+import org.eclipse.cdt.internal.ui.text.spelling.CSpellingService;
+import org.eclipse.jface.text.source.ISourceViewer;
+import org.eclipse.ui.texteditor.spelling.SpellingReconcileStrategy;
+
+public final class CSpellingReconcileStrategy extends SpellingReconcileStrategy {
+
+	public CSpellingReconcileStrategy(ISourceViewer viewer) {
+		super(viewer, CSpellingService.getInstance());
+	}
+}

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/internal/editor/CSpellingReconciler.java

@@ -0,0 +1,32 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Bachmann electronic GmbH and others.
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Gesa Hentschke (Bachmann electronic GmbH) - initial implementation
+ *******************************************************************************/
+
+package org.eclipse.cdt.lsp.internal.editor;
+
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.jface.text.reconciler.Reconciler;
+import org.eclipse.jface.text.source.ISourceViewer;
+
+public final class CSpellingReconciler extends Reconciler {
+
+	@Override
+	public void install(ITextViewer textViewer) {
+		if (textViewer instanceof ISourceViewer sourceViewer) {
+			this.setReconcilingStrategy(new CSpellingReconcileStrategy(sourceViewer), IDocument.DEFAULT_CONTENT_TYPE);
+		}
+		// call super.install AFTER the CSpellingReconcileStrategy has been added to the super class via setReconcilingStrategy call,
+		// otherwise reconcilerDocumentChanged (which is called during super.install) would not be performed on our CSpellingReconcileStrategy
+		super.install(textViewer);
+	}
+}

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/internal/editor/SpellingEnabled.java

@@ -0,0 +1,58 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Bachmann electronic GmbH and others.
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Gesa Hentschke (Bachmann electronic GmbH) - initial implementation
+ *******************************************************************************/
+
+package org.eclipse.cdt.lsp.internal.editor;
+
+import java.util.Optional;
+
+import org.eclipse.cdt.lsp.LspUtils;
+import org.eclipse.core.expressions.PropertyTester;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.ui.IEditorInput;
+import org.eclipse.ui.IFileEditorInput;
+import org.eclipse.ui.editors.text.EditorsUI;
+import org.eclipse.ui.editors.text.TextEditor;
+import org.eclipse.ui.texteditor.spelling.SpellingService;
+
+public final class SpellingEnabled extends PropertyTester {
+	private static final String EMPTY = ""; //$NON-NLS-1$
+
+	@Override
+	public boolean test(Object receiver, String property, Object[] args, Object expectedValue) {
+		return isSpellingEnabled() && isCContentType(receiver);
+	}
+
+	private static boolean isSpellingEnabled() {
+		return EditorsUI.getPreferenceStore().getBoolean(SpellingService.PREFERENCE_SPELLING_ENABLED);
+	}
+
+	private static boolean isCContentType(Object receiver) {
+		if (receiver instanceof TextEditor editor) {
+			return LspUtils.isCContentType(getContentType(editor.getEditorInput()));
+		}
+		return false;
+	}
+
+	private static String getContentType(IEditorInput editorInput) {
+		if (editorInput instanceof IFileEditorInput fileEditorInput) {
+			try {
+				return Optional.ofNullable(fileEditorInput.getFile().getContentDescription())
+						.map(cd -> cd.getContentType()).map(ct -> ct.getId()).orElse(EMPTY);
+			} catch (CoreException e) {
+				// do nothing
+			}
+		}
+		return EMPTY;
+	}
+
+}

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/internal/messages/LspUiMessages.java

@@ -24,9 +24,20 @@ public class LspUiMessages extends NLS {
 	}
 
 	public static String NavigatorView_ErrorOnLoad;
+
+	public static String LspEditorConfigurationPage_spelling_link;
+	public static String LspEditorConfigurationPage_spelling_link_tooltip;
+
 	public static String LspEditorConfigurationPage_enable_project_specific;
 	public static String LspEditorConfigurationPage_configure_ws_specific;
 	public static String LspEditorConfigurationPage_preferLspEditor;
 	public static String LspEditorConfigurationPage_preferLspEditor_description;
 
+	public static String SaveActionsConfigurationPage_FormatSourceCode;
+	public static String SaveActionsConfigurationPage_FormatSourceCode_description;
+	public static String SaveActionsConfigurationPage_FormatAllLines;
+	public static String SaveActionsConfigurationPage_FormatAllLines_description;
+	public static String SaveActionsConfigurationPage_FormatEditedLines;
+	public static String SaveActionsConfigurationPage_FormatEditedLines_description;
+
 }

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/internal/messages/LspUiMessages.properties

@@ -13,8 +13,18 @@
 
 NavigatorView_ErrorOnLoad = Loading the symbols encountered an error; see the Error Log for more information
 
+LspEditorConfigurationPage_spelling_link=Spelling preferences are set via <a href="org.eclipse.ui.editors.preferencePages.Spelling">Text Editors Spelling</a>.
+LspEditorConfigurationPage_spelling_link_tooltip=Show the shared text editor spelling preferences
+
 LspEditorConfigurationPage_enable_project_specific=Enable project-specific settings
 LspEditorConfigurationPage_configure_ws_specific=Configure Workspace Settings...
-LspEditorConfigurationPage_preferLspEditor=Prefer C/C++ Editor (LSP)
-LspEditorConfigurationPage_preferLspEditor_description=Prefer to use language server based C/C++ Editor instead of classic C/C++ Editor
+LspEditorConfigurationPage_preferLspEditor=Set C/C++ Editor (LSP) as default
+LspEditorConfigurationPage_preferLspEditor_description=The language server based C/C++ Editor will be used to open C/C++ source files.
+
+SaveActionsConfigurationPage_FormatSourceCode=Format source code
+SaveActionsConfigurationPage_FormatSourceCode_description=Formats source code when file is saved
+SaveActionsConfigurationPage_FormatAllLines=Format all lines
+SaveActionsConfigurationPage_FormatAllLines_description=Formats all source code lines
+SaveActionsConfigurationPage_FormatEditedLines=Format edited lines
+SaveActionsConfigurationPage_FormatEditedLines_description=Formats edited source code lines only
 

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/services/ClangdLanguageServer.java

@@ -9,24 +9,32 @@
  *
  * Contributors:
  * Dominic Scharfe (COSEDA Technologies GmbH) - initial implementation
+ * Dietrich Travkin (Solunar GmbH) - extensions for AST and symbol info
  *******************************************************************************/
 package org.eclipse.cdt.lsp.services;
 
 import java.util.concurrent.CompletableFuture;
 
+import org.eclipse.cdt.lsp.services.ast.AstNode;
+import org.eclipse.cdt.lsp.services.ast.AstParams;
+import org.eclipse.cdt.lsp.services.symbolinfo.SymbolDetails;
 import org.eclipse.lsp4j.TextDocumentIdentifier;
+import org.eclipse.lsp4j.TextDocumentPositionParams;
 import org.eclipse.lsp4j.jsonrpc.services.JsonRequest;
 import org.eclipse.lsp4j.services.LanguageServer;
 
 /**
  * Interface extending the {@link LanguageServer} with clangd extensions.
+ * More details about LSP usage and extension see the
+ * <a href="https://github.com/eclipse-lsp4j/lsp4j/blob/main/documentation/jsonrpc.md">
+ * org.eclipse.lsp4j project's documentation</a>.
  *
  * @see https://clangd.llvm.org/extensions
  */
 public interface ClangdLanguageServer extends LanguageServer {
 
 	/**
-	 * The switchSourceHeader request is sent from the client to the server to
+	 * The <em>textDocument/switchSourceHeader</em> request is sent from the client to the server to
 	 * <ul>
 	 * <li>get the corresponding header if a source file was provided</li>
 	 * <li>get the source file if a header was provided</li>
@@ -39,4 +47,31 @@ public interface ClangdLanguageServer extends LanguageServer {
 	 */
 	@JsonRequest(value = "textDocument/switchSourceHeader")
 	CompletableFuture<String> switchSourceHeader(TextDocumentIdentifier textDocument);
+
+	/**
+	 * The <em>textDocument/ast</em> request is sent from the client to the server in order to get
+	 * details about the program structure (so called abstract syntax tree or AST) in a C++ file.
+	 * The structure can be requested for the whole file or for a certain range.
+	 *
+	 * @param astParameters request parameters containing the document identifier and requested documented range
+	 * @return the abstract syntax tree root node (with child hierarchy) for the requested document and range
+	 *
+	 * @see https://clangd.llvm.org/extensions#ast
+	 */
+	@JsonRequest(value = "textDocument/ast")
+	CompletableFuture<AstNode> getAst(AstParams astParameters);
+
+	/**
+	 * The <em>textDocument/symbolInfo</em> request is sent from the client to the server in order to access
+	 * details about the element under the cursor. The response provides details like the element's name,
+	 * its parent container's name, and some clangd-specific element IDs (e.g. the "unified symbol resolution"
+	 * identifier).
+	 *
+	 * @param positionParameters request parameters containing the document identifier and the current cursor position
+	 * @return the details about the symbol on the given position
+	 *
+	 * @see https://clangd.llvm.org/extensions#symbol-info-request
+	 */
+	@JsonRequest(value = "textDocument/symbolInfo")
+	CompletableFuture<SymbolDetails[]> getSymbolInfo(TextDocumentPositionParams positionParameters);
 }

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/services/ast/AstNode.java

@@ -0,0 +1,167 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Advantest Europe GmbH and others.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Dietrich Travkin (Solunar GmbH) - Initial implementation
+ *******************************************************************************/
+package org.eclipse.cdt.lsp.services.ast;
+
+import java.util.Arrays;
+
+import org.eclipse.cdt.lsp.services.ClangdLanguageServer;
+import org.eclipse.lsp4j.Range;
+import org.eclipse.lsp4j.jsonrpc.validation.NonNull;
+import org.eclipse.lsp4j.util.Preconditions;
+import org.eclipse.lsp4j.util.ToStringBuilder;
+
+/**
+ * Return type for the <em>textDocument/ast</em> request.
+ * This class was generated by the <em>org.eclipse.lsp4j.generator</em> bundle
+ * using xtend (see {@link org.eclipse.lsp4j.generator.JsonRpcData JsonRpcData} and
+ * the <a href="https://github.com/eclipse-lsp4j/lsp4j/blob/main/documentation/jsonrpc.md">documentation</a>).
+ *
+ * @see {@link ClangdLanguageServer#getAst(AstParams)}
+ */
+public class AstNode {
+
+	@NonNull
+	private String role;
+
+	@NonNull
+	private String kind;
+
+	private String detail;
+
+	private String arcana;
+
+	@NonNull
+	private Range range;
+
+	private AstNode[] children;
+
+	public AstNode() {
+
+	}
+
+	@NonNull
+	public String getRole() {
+		return role;
+	}
+
+	public void setRole(@NonNull final String role) {
+		this.role = Preconditions.<String>checkNotNull(role, "role"); //$NON-NLS-1$
+	}
+
+	@NonNull
+	public String getKind() {
+		return this.kind;
+	}
+
+	public void setKind(@NonNull final String kind) {
+		this.kind = Preconditions.<String>checkNotNull(kind, "kind"); //$NON-NLS-1$
+	}
+
+	public String getDetail() {
+		return detail;
+	}
+
+	public void setDetail(final String detail) {
+		this.detail = detail;
+	}
+
+	public String getArcana() {
+		return arcana;
+	}
+
+	public void setArcana(final String arcana) {
+		this.arcana = arcana;
+	}
+
+	@NonNull
+	public Range getRange() {
+		return range;
+	}
+
+	public void setRange(@NonNull final Range range) {
+		this.range = Preconditions.<Range>checkNotNull(range, "range"); //$NON-NLS-1$
+	}
+
+	public AstNode[] getChildren() {
+		return children;
+	}
+
+	public void setChildren(final AstNode[] children) {
+		this.children = children;
+	}
+
+	@Override
+	public String toString() {
+		ToStringBuilder b = new ToStringBuilder(this);
+		b.add("role", this.role); //$NON-NLS-1$
+		b.add("kind", this.kind); //$NON-NLS-1$
+		b.add("detail", this.detail); //$NON-NLS-1$
+		b.add("arcana", this.arcana); //$NON-NLS-1$
+		b.add("range", this.range); //$NON-NLS-1$
+		b.add("children", this.children); //$NON-NLS-1$
+		return b.toString();
+	}
+
+	@Override
+	public boolean equals(final Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		AstNode other = (AstNode) obj;
+		if (this.role == null) {
+			if (other.role != null)
+				return false;
+		} else if (!this.role.equals(other.role))
+			return false;
+		if (this.kind == null) {
+			if (other.kind != null)
+				return false;
+		} else if (!this.kind.equals(other.kind))
+			return false;
+		if (this.detail == null) {
+			if (other.detail != null)
+				return false;
+		} else if (!this.detail.equals(other.detail))
+			return false;
+		if (this.arcana == null) {
+			if (other.arcana != null)
+				return false;
+		} else if (!this.arcana.equals(other.arcana))
+			return false;
+		if (this.range == null) {
+			if (other.range != null)
+				return false;
+		} else if (!this.range.equals(other.range))
+			return false;
+		if (this.children == null) {
+			if (other.children != null)
+				return false;
+		} else if (!Arrays.deepEquals(this.children, other.children))
+			return false;
+		return true;
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + ((this.role == null) ? 0 : this.role.hashCode());
+		result = prime * result + ((this.kind == null) ? 0 : this.kind.hashCode());
+		result = prime * result + ((this.detail == null) ? 0 : this.detail.hashCode());
+		result = prime * result + ((this.arcana == null) ? 0 : this.arcana.hashCode());
+		result = prime * result + ((this.range == null) ? 0 : this.range.hashCode());
+		return prime * result + ((this.children == null) ? 0 : Arrays.deepHashCode(this.children));
+	}
+}

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/services/ast/AstParams.java

@@ -0,0 +1,100 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Advantest Europe GmbH and others.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Dietrich Travkin (Solunar GmbH) - Initial implementation
+ *******************************************************************************/
+package org.eclipse.cdt.lsp.services.ast;
+
+import org.eclipse.cdt.lsp.services.ClangdLanguageServer;
+import org.eclipse.lsp4j.Range;
+import org.eclipse.lsp4j.TextDocumentIdentifier;
+import org.eclipse.lsp4j.jsonrpc.validation.NonNull;
+import org.eclipse.lsp4j.util.Preconditions;
+import org.eclipse.lsp4j.util.ToStringBuilder;
+
+/**
+ * Parameter object type for the <em>textDocument/ast</em> request.
+ * This class was generated by the <em>org.eclipse.lsp4j.generator</em> bundle
+ * using xtend (see {@link org.eclipse.lsp4j.generator.JsonRpcData JsonRpcData} and
+ * the <a href="https://github.com/eclipse-lsp4j/lsp4j/blob/main/documentation/jsonrpc.md">documentation</a>).
+ *
+ * @see {@link ClangdLanguageServer#getAst(AstParams)}
+ */
+public class AstParams {
+
+	@NonNull
+	private TextDocumentIdentifier textDocument;
+
+	@NonNull
+	private Range range;
+
+	public AstParams() {
+	}
+
+	public AstParams(@NonNull final TextDocumentIdentifier textDocument, @NonNull final Range range) {
+		this.textDocument = Preconditions.<TextDocumentIdentifier>checkNotNull(textDocument, "textDocument"); //$NON-NLS-1$
+		this.range = Preconditions.<Range>checkNotNull(range, "range"); //$NON-NLS-1$
+	}
+
+	@NonNull
+	public TextDocumentIdentifier getTextDocument() {
+		return this.textDocument;
+	}
+
+	public void setTextDocument(@NonNull final TextDocumentIdentifier textDocument) {
+		this.textDocument = Preconditions.<TextDocumentIdentifier>checkNotNull(textDocument, "textDocument"); //$NON-NLS-1$
+	}
+
+	@NonNull
+	public Range getRange() {
+		return range;
+	}
+
+	public void setRange(@NonNull Range range) {
+		this.range = Preconditions.<Range>checkNotNull(range, "range"); //$NON-NLS-1$
+	}
+
+	@Override
+	public String toString() {
+		ToStringBuilder b = new ToStringBuilder(this);
+		b.add("textDocument", getTextDocument()); //$NON-NLS-1$
+		b.add("range", getRange()); //$NON-NLS-1$
+		return b.toString();
+	}
+
+	@Override
+	public boolean equals(final Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		AstParams other = (AstParams) obj;
+		if (this.getTextDocument() == null) {
+			if (other.getTextDocument() != null)
+				return false;
+		} else if (!this.getTextDocument().equals(other.getTextDocument()))
+			return false;
+		if (this.range == null) {
+			if (other.range != null)
+				return false;
+		} else if (!this.range.equals(other.range))
+			return false;
+		return true;
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + ((this.getTextDocument() == null) ? 0 : this.getTextDocument().hashCode());
+		return prime * result + ((this.range == null) ? 0 : this.range.hashCode());
+	}
+}

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/services/symbolinfo/RangeAndUri.java

@@ -0,0 +1,91 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Advantest Europe GmbH and others.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Dietrich Travkin (Solunar GmbH) - Initial implementation
+ *******************************************************************************/
+package org.eclipse.cdt.lsp.services.symbolinfo;
+
+import org.eclipse.cdt.lsp.services.ClangdLanguageServer;
+import org.eclipse.lsp4j.Range;
+import org.eclipse.lsp4j.jsonrpc.validation.NonNull;
+import org.eclipse.lsp4j.util.Preconditions;
+import org.eclipse.lsp4j.util.ToStringBuilder;
+
+/**
+ * Data type used in {@link SymbolDetails} for the <em>textDocument/symbolInfo</em> request.
+ * This class was generated by the <em>org.eclipse.lsp4j.generator</em> bundle
+ * using xtend (see {@link org.eclipse.lsp4j.generator.JsonRpcData JsonRpcData} and
+ * the <a href="https://github.com/eclipse-lsp4j/lsp4j/blob/main/documentation/jsonrpc.md">documentation</a>).
+ *
+ * @see {@link SymbolDetails}
+ * @see {@link ClangdLanguageServer#getSymbolInfo(org.eclipse.lsp4j.TextDocumentPositionParams)}
+ */
+public class RangeAndUri {
+	@NonNull
+	private Range range;
+
+	@NonNull
+	private String uri;
+
+	@NonNull
+	public Range getRange() {
+		return this.range;
+	}
+
+	public void setRange(@NonNull final Range range) {
+		this.range = Preconditions.<Range>checkNotNull(range, "range"); //$NON-NLS-1$
+	}
+
+	@NonNull
+	public String getUri() {
+		return this.uri;
+	}
+
+	public void setUri(@NonNull final String uri) {
+		this.uri = Preconditions.<String>checkNotNull(uri, "uri"); //$NON-NLS-1$
+	}
+
+	@Override
+	public String toString() {
+		ToStringBuilder b = new ToStringBuilder(this);
+		b.add("range", this.range); //$NON-NLS-1$
+		b.add("uri", this.uri); //$NON-NLS-1$
+		return b.toString();
+	}
+
+	@Override
+	public boolean equals(final Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		RangeAndUri other = (RangeAndUri) obj;
+		if (this.range == null) {
+			if (other.range != null)
+				return false;
+		} else if (!this.range.equals(other.range))
+			return false;
+		if (this.uri == null) {
+			if (other.uri != null)
+				return false;
+		} else if (!this.uri.equals(other.uri))
+			return false;
+		return true;
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + ((this.range == null) ? 0 : this.range.hashCode());
+		return prime * result + ((this.uri == null) ? 0 : this.uri.hashCode());
+	}
+}

bundles/org.eclipse.cdt.lsp/src/org/eclipse/cdt/lsp/services/symbolinfo/SymbolDetails.java

@@ -0,0 +1,160 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Advantest Europe GmbH and others.
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * Dietrich Travkin (Solunar GmbH) - Initial implementation
+ *******************************************************************************/
+package org.eclipse.cdt.lsp.services.symbolinfo;
+
+import org.eclipse.cdt.lsp.services.ClangdLanguageServer;
+import org.eclipse.lsp4j.jsonrpc.validation.NonNull;
+import org.eclipse.lsp4j.util.Preconditions;
+import org.eclipse.lsp4j.util.ToStringBuilder;
+
+/**
+ * Return type for the <em>textDocument/symbolInfo</em> request.
+ * This class was generated by the <em>org.eclipse.lsp4j.generator</em> bundle
+ * using xtend (see {@link org.eclipse.lsp4j.generator.JsonRpcData JsonRpcData} and
+ * the <a href="https://github.com/eclipse-lsp4j/lsp4j/blob/main/documentation/jsonrpc.md">documentation</a>).
+ *
+ * @see {@link ClangdLanguageServer#getSymbolInfo(org.eclipse.lsp4j.TextDocumentPositionParams)}
+ */
+public class SymbolDetails {
+
+	@NonNull
+	private String name;
+
+	@NonNull
+	private String containerName;
+
+	@NonNull
+	private String usr;
+
+	private String id;
+
+	private RangeAndUri declarationRange;
+
+	private RangeAndUri definitionRange;
+
+	@NonNull
+	public String getName() {
+		return this.name;
+	}
+
+	public void setName(@NonNull final String name) {
+		this.name = Preconditions.<String>checkNotNull(name, "name"); //$NON-NLS-1$
+	}
+
+	@NonNull
+	public String getContainerName() {
+		return this.containerName;
+	}
+
+	public void setContainerName(@NonNull final String containerName) {
+		this.containerName = Preconditions.<String>checkNotNull(containerName, "containerName"); //$NON-NLS-1$
+	}
+
+	@NonNull
+	public String getUsr() {
+		return this.usr;
+	}
+
+	public void setUsr(@NonNull final String usr) {
+		this.usr = Preconditions.<String>checkNotNull(usr, "usr"); //$NON-NLS-1$
+	}
+
+	public String getId() {
+		return this.id;
+	}
+
+	public void setId(final String id) {
+		this.id = id;
+	}
+
+	public RangeAndUri getDeclarationRange() {
+		return this.declarationRange;
+	}
+
+	public void setDeclarationRange(final RangeAndUri declarationRange) {
+		this.declarationRange = declarationRange;
+	}
+
+	public RangeAndUri getDefinitionRange() {
+		return this.definitionRange;
+	}
+
+	public void setDefinitionRange(final RangeAndUri definitionRange) {
+		this.definitionRange = definitionRange;
+	}
+
+	@Override
+	public String toString() {
+		ToStringBuilder b = new ToStringBuilder(this);
+		b.add("name", this.name); //$NON-NLS-1$
+		b.add("containerName", this.containerName); //$NON-NLS-1$
+		b.add("usr", this.usr); //$NON-NLS-1$
+		b.add("id", this.id); //$NON-NLS-1$
+		b.add("declarationRange", this.declarationRange); //$NON-NLS-1$
+		b.add("definitionRange", this.definitionRange); //$NON-NLS-1$
+		return b.toString();
+	}
+
+	@Override
+	public boolean equals(final Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		SymbolDetails other = (SymbolDetails) obj;
+		if (this.name == null) {
+			if (other.name != null)
+				return false;
+		} else if (!this.name.equals(other.name))
+			return false;
+		if (this.containerName == null) {
+			if (other.containerName != null)
+				return false;
+		} else if (!this.containerName.equals(other.containerName))
+			return false;
+		if (this.usr == null) {
+			if (other.usr != null)
+				return false;
+		} else if (!this.usr.equals(other.usr))
+			return false;
+		if (this.id == null) {
+			if (other.id != null)
+				return false;
+		} else if (!this.id.equals(other.id))
+			return false;
+		if (this.declarationRange == null) {
+			if (other.declarationRange != null)
+				return false;
+		} else if (!this.declarationRange.equals(other.declarationRange))
+			return false;
+		if (this.definitionRange == null) {
+			if (other.definitionRange != null)
+				return false;
+		} else if (!this.definitionRange.equals(other.definitionRange))
+			return false;
+		return true;
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + ((this.name == null) ? 0 : this.name.hashCode());
+		result = prime * result + ((this.containerName == null) ? 0 : this.containerName.hashCode());
+		result = prime * result + ((this.usr == null) ? 0 : this.usr.hashCode());
+		result = prime * result + ((this.id == null) ? 0 : this.id.hashCode());
+		result = prime * result + ((this.declarationRange == null) ? 0 : this.declarationRange.hashCode());
+		return prime * result + ((this.definitionRange == null) ? 0 : this.definitionRange.hashCode());
+	}
+}

features/org.eclipse.cdt.lsp.feature/feature.xml

@@ -12,7 +12,7 @@
 <feature
       id="org.eclipse.cdt.lsp.feature"
       label="%featureName"
-      version="1.0.0.qualifier"
+      version="1.1.0.qualifier"
       provider-name="%providerName"
       license-feature="org.eclipse.license"
       license-feature-version="0.0.0">

pom.xml

@@ -12,7 +12,7 @@
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.eclipse.cdt.lsp</groupId>
  <artifactId>org.eclipse.cdt.lsp.root</artifactId>
- <version>1.0.0-SNAPSHOT</version>
+ <version>1.1.0-SNAPSHOT</version>
  <packaging>pom</packaging>
 
  <properties>

releng/org.eclipse.cdt.lsp.repository/pom.xml

@@ -17,11 +17,11 @@
   <parent>
     <groupId>org.eclipse.cdt.lsp</groupId>
     <artifactId>org.eclipse.cdt.lsp.root</artifactId>
-    <version>1.0.0-SNAPSHOT</version>
+    <version>1.1.0-SNAPSHOT</version>
     <relativePath>../../pom.xml</relativePath>
   </parent>
 
-  <version>1.0.0-SNAPSHOT</version>
+  <version>1.1.0-SNAPSHOT</version>
   <artifactId>org.eclipse.cdt.lsp.repository</artifactId>
   <packaging>eclipse-repository</packaging>
 

releng/org.eclipse.cdt.lsp.target/org.eclipse.cdt.lsp.target.target

@@ -23,7 +23,7 @@
 			<unit id="org.eclipse.linuxtools.docker.feature.feature.group" version="0.0.0" />
 		</location>
 		<location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">
-			<repository location="https://download.eclipse.org/lsp4e/snapshots/" />
+			<repository location="https://download.eclipse.org/lsp4e/releases/latest/" />
 			<unit id="org.eclipse.lsp4e" version="0.0.0" />
 			<unit id="org.eclipse.lsp4e.debug" version="0.0.0" />
 		</location>
@@ -37,7 +37,7 @@
 			<unit id="org.eclipse.swtbot.feature.group" version="0.0.0" />
 		</location>
 		<location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">
-			<repository location="https://download.eclipse.org/tm4e/snapshots/" />
+			<repository location="https://download.eclipse.org/tm4e/releases/latest/" />
 			<unit id="org.eclipse.tm4e.feature.feature.group" version="0.0.0" />
 			<unit id="org.eclipse.tm4e.language_pack.feature.feature.group" version="0.0.0" />
 		</location>

tests/org.eclipse.cdt.lsp.clangd.tests/src/org/eclipse/cdt/lsp/clangd/tests/ClangdConfigurationFileManagerTest.java

@@ -0,0 +1,298 @@
+/*******************************************************************************
+ * Copyright (c) 2023 Bachmann electronic GmbH and others.
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Gesa Hentschke (Bachmann electronic GmbH) - initial implementation
+ *     Alexander Fedorov (ArSysOp) - extract headless part
+ *******************************************************************************/
+
+package org.eclipse.cdt.lsp.clangd.tests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.io.ByteArrayInputStream;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.UnsupportedEncodingException;
+import java.nio.file.Files;
+import java.util.Arrays;
+
+import org.eclipse.cdt.core.settings.model.CProjectDescriptionEvent;
+import org.eclipse.cdt.core.settings.model.ICBuildSetting;
+import org.eclipse.cdt.core.settings.model.ICProjectDescription;
+import org.eclipse.cdt.internal.core.settings.model.CConfigurationDescriptionCache;
+import org.eclipse.cdt.lsp.clangd.ClangdCProjectDescriptionListener;
+import org.eclipse.cdt.lsp.clangd.ClangdConfigurationFileManager;
+import org.eclipse.cdt.lsp.clangd.MacroResolver;
+import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.core.runtime.Path;
+import org.eclipse.ui.PlatformUI;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.TestInfo;
+import org.junit.jupiter.api.io.TempDir;
+
+final class ClangdConfigurationFileManagerTest {
+
+	private static final String RELATIVE_DIR_PATH_BUILD_DEFAULT = "build" + File.separator + "default";
+	private static final String RELATIVE_DIR_PATH_BUILD_DEBUG = "build" + File.separator + "debug";
+	private static final String EXPANDED_CDB_SETTING = "CompileFlags: {Add: -ferror-limit=500, CompilationDatabase: %s, Compiler: g++}\nDiagnostics:\n  ClangTidy: {Add: modernize*, Remove: modernize-use-trailing-return-type}\n";
+	private static final String DEFAULT_CDB_SETTING = "CompileFlags: {CompilationDatabase: %s}";
+	private static final String MODIFIED_DEFAULT_CDB_SETTING = DEFAULT_CDB_SETTING + "\n";
+	private static final String INVALID_YAML_SYNTAX_CONTAINS_TAB = "CompileFlags:\n\tCompilationDatabase: %s";
+	private static final String INVALID_YAML_SYNTAX_MISSING_BRACE = "CompileFlags: {CompilationDatabase: Release\r\n";
+	private final ClangdCProjectDescriptionListener clangdConfigurationManager = PlatformUI.getWorkbench()
+			.getService(ClangdCProjectDescriptionListener.class);
+	private final MacroResolver macroResolver = new MockMacroResolver();
+	private IProject project;
+
+	private static CProjectDescriptionEvent event = mock(CProjectDescriptionEvent.class);
+	private static ICProjectDescription description = mock(ICProjectDescription.class);
+	private static CConfigurationDescriptionCache config = mock(CConfigurationDescriptionCache.class);
+	private static ICBuildSetting setting = mock(ICBuildSetting.class);
+	private Path cwdBuilder;
+
+	@TempDir
+	private static File TEMP_DIR;
+
+	@BeforeAll
+	public static void setUp() throws Exception {
+		when(event.getNewCProjectDescription()).thenReturn(description);
+		when(description.getDefaultSettingConfiguration()).thenReturn(config);
+		when(config.getBuildSetting()).thenReturn(setting);
+	}
+
+	@BeforeEach
+	public void setUp(TestInfo testInfo) throws CoreException {
+		var projectName = TestUtils.getName(testInfo);
+		project = TestUtils.createCProject(projectName);
+		TestUtils.setLspPreferred(project, true);
+		when(event.getProject()).thenReturn(project);
+	}
+
+	@AfterEach
+	public void cleanUp() throws CoreException {
+		TestUtils.deleteProject(project);
+	}
+
+	private static File createFile(File parent, String format, String cdbDirectoryPath) throws FileNotFoundException {
+		return createFile(parent, ClangdConfigurationFileManager.CLANGD_CONFIG_FILE_NAME, format, cdbDirectoryPath);
+	}
+
+	private static File createFile(File parent, String fileName, String format, String cdbDirectoryPath)
+			throws FileNotFoundException {
+		var file = new File(parent, fileName);
+		try (var writer = new PrintWriter(file)) {
+			writer.printf(format, cdbDirectoryPath);
+		}
+		return file;
+	}
+
+	/**
+	 * Creates a .clangd file in the current project
+	 * @param format
+	 * @param cdbDirectoryPath
+	 * @return
+	 * @throws UnsupportedEncodingException
+	 * @throws IOException
+	 * @throws CoreException
+	 */
+	private IFile createConfigFile(String format, String cdbDirectoryPath)
+			throws UnsupportedEncodingException, IOException, CoreException {
+		var file = project.getFile(ClangdConfigurationFileManager.CLANGD_CONFIG_FILE_NAME);
+		try (final var data = new ByteArrayInputStream(
+				String.format(format, cdbDirectoryPath).getBytes(project.getDefaultCharset()))) {
+			if (!file.exists()) {
+				file.create(data, false, new NullProgressMonitor());
+			} else {
+				file.setContents(data, IResource.KEEP_HISTORY, new NullProgressMonitor());
+			}
+		}
+		return file;
+	}
+
+	/**
+	 * Test whether a new .clangd file will be created in the given project directory with the given
+	 * configuration database (cdb) directory path (build/default) when the file does not exist.
+	 *
+	 * @throws IOException
+	 * @throws CoreException
+	 */
+	@Test
+	void testCreateClangdConfigFileInProject() throws IOException, CoreException {
+		var projectDir = project.getLocation().toPortableString();
+		var configFile = new File(projectDir, ClangdConfigurationFileManager.CLANGD_CONFIG_FILE_NAME);
+		var refFile = createFile(TEMP_DIR, DEFAULT_CDB_SETTING, RELATIVE_DIR_PATH_BUILD_DEFAULT);
+		// The current working directory of the builder in the project is set to RELATIVE_DIR_PATH_BUILD_DEFAULT:
+		cwdBuilder = new Path(project.getLocation().append(RELATIVE_DIR_PATH_BUILD_DEFAULT).toPortableString());
+		when(setting.getBuilderCWD()).thenReturn(cwdBuilder);
+
+		// GIVEN a project without .clangd project configuration file:
+		assertTrue(configFile.length() == 0);
+		// WHEN the ClangdConfigurationManager.handleEvent method gets called:
+		clangdConfigurationManager.handleEvent(event, macroResolver);
+		// THEN a new file has been created in the project:
+		assertTrue(configFile.length() > 0);
+		// AND the file content is as expected:
+		assertTrue(Arrays.equals(Files.readAllBytes(configFile.toPath()), Files.readAllBytes(refFile.toPath())));
+
+		//clean up:
+		refFile.delete();
+	}
+
+	/**
+	 * Test whether the new configuration database (cdb) directory path (build/debug) will be written to an existing but empty .clangd file
+	 *
+	 * @throws IOException
+	 * @throws CoreException
+	 */
+	@Test
+	void testEmptyClangdConfigFileInProject() throws IOException, CoreException {
+		var refFile = createFile(TEMP_DIR, DEFAULT_CDB_SETTING, RELATIVE_DIR_PATH_BUILD_DEFAULT);
+		// The current working directory of the builder in the project is set to RELATIVE_DIR_PATH_BUILD_DEFAULT:
+		cwdBuilder = new Path(project.getLocation().append(RELATIVE_DIR_PATH_BUILD_DEFAULT).toPortableString());
+		when(setting.getBuilderCWD()).thenReturn(cwdBuilder);
+
+		// GIVEN an existing but empty .clangd configuration file in the project:
+		var emptyConfigFile = createConfigFile("%s", "  ");
+		// WHEN the ClangdConfigurationManager.handleEvent method gets called with a new cdb path "build/debug":
+		clangdConfigurationManager.handleEvent(event, macroResolver);
+		// THEN the updated file matches the expected content with the given CompilationDatabase directory "build/debug":
+		assertTrue(Arrays.equals(Files.readAllBytes(emptyConfigFile.getLocation().toFile().toPath()),
+				Files.readAllBytes(refFile.toPath())));
+
+		//clean up:
+		refFile.delete();
+	}
+
+	/**
+	 * Test whether the new configuration database (cdb) directory path (build/debug) will be written to an existing .clangd file
+	 *
+	 * @throws IOException
+	 * @throws CoreException
+	 */
+	@Test
+	void testUpdateClangdConfigFileInProject() throws IOException, CoreException {
+		var projectDir = project.getLocation().toPortableString();
+		var configFile = new File(projectDir, ClangdConfigurationFileManager.CLANGD_CONFIG_FILE_NAME);
+		var refFileDefault = createFile(TEMP_DIR, ".clangdDefault", DEFAULT_CDB_SETTING,
+				RELATIVE_DIR_PATH_BUILD_DEFAULT);
+		// Use MODIFIED_DEFAULT_CDB_SETTING here, because the org.yaml.snakeyaml.Yaml.dump appends a '\n' at the last line:
+		var refFileDebug = createFile(TEMP_DIR, ".clangdDebug", MODIFIED_DEFAULT_CDB_SETTING,
+				RELATIVE_DIR_PATH_BUILD_DEBUG);
+		// The current working directory of the builder in the project is set to RELATIVE_DIR_PATH_BUILD_DEFAULT:
+		cwdBuilder = new Path(project.getLocation().append(RELATIVE_DIR_PATH_BUILD_DEFAULT).toPortableString());
+		when(setting.getBuilderCWD()).thenReturn(cwdBuilder);
+
+		// GIVEN a project without .clangd project configuration file:
+		assertTrue(configFile.length() == 0);
+		// AND the ClangdConfigurationManager.handleEvent method gets called:
+		clangdConfigurationManager.handleEvent(event, macroResolver);
+		// THEN a new file has been created in the project:
+		assertTrue(configFile.length() > 0);
+		// THEN the created file matches the expected content:
+		assertTrue(Arrays.equals(Files.readAllBytes(configFile.toPath()), Files.readAllBytes(refFileDefault.toPath())));
+
+		// WHEN the CWD in the build configuration changes to build/debug:
+		cwdBuilder = new Path(project.getLocation().append(RELATIVE_DIR_PATH_BUILD_DEBUG).toPortableString());
+		when(setting.getBuilderCWD()).thenReturn(cwdBuilder);
+		// AND the handleEvent gets called again:
+		clangdConfigurationManager.handleEvent(event, macroResolver);
+		// THEN the updated file matches the expected content:
+		assertTrue(Arrays.equals(Files.readAllBytes(configFile.toPath()), Files.readAllBytes(refFileDebug.toPath())));
+
+		//clean up:
+		refFileDefault.delete();
+		refFileDebug.delete();
+	}
+
+	/**
+	 * Test whether the new configuration database (cdb) directory path (build/debug) will be written to an existing expanded .clangd file
+	 *
+	 * @throws IOException
+	 * @throws CoreException
+	 */
+	@Test
+	void testUpdateExpandedClangdConfigFileInProject() throws IOException, CoreException {
+		var refFile = createFile(TEMP_DIR, EXPANDED_CDB_SETTING, RELATIVE_DIR_PATH_BUILD_DEBUG);
+
+		// GIVEN an existing expanded .clangd configuration file in the project pointing to "build/default":
+		var configFile = createConfigFile(EXPANDED_CDB_SETTING, RELATIVE_DIR_PATH_BUILD_DEFAULT);
+		// WHEN the ClangdConfigurationManager.handleEvent method gets called and the builder CWD points to "build/debug":
+		cwdBuilder = new Path(project.getLocation().append(RELATIVE_DIR_PATH_BUILD_DEBUG).toPortableString());
+		when(setting.getBuilderCWD()).thenReturn(cwdBuilder);
+		clangdConfigurationManager.handleEvent(event, macroResolver);
+		// THEN the updated file matches the expected content:
+		assertTrue(Arrays.equals(Files.readAllBytes(configFile.getLocation().toFile().toPath()),
+				Files.readAllBytes(refFile.toPath())));
+
+		//clean up:
+		refFile.delete();
+	}
+
+	/**
+	 * Test whether a ScannerException will be thrown if the file contains invalid yaml syntax (here: tab)
+	 *
+	 * @throws IOException
+	 * @throws CoreException
+	 */
+	@Test
+	void testInvalidYamlSyntax() throws IOException, CoreException {
+		// GIVEN an existing .clangd configuration file with invalid yaml syntax (contains tab):
+		var configFile = createConfigFile(INVALID_YAML_SYNTAX_CONTAINS_TAB, RELATIVE_DIR_PATH_BUILD_DEFAULT);
+		String beforeSet;
+		try (var inputStream = configFile.getContents()) {
+			beforeSet = new String(inputStream.readAllBytes());
+		}
+		// WHEN the ClangdConfigurationManager.setCompilationDatabasePath method gets called with a new cdb path "build/debug":
+		((ClangdConfigurationFileManager) clangdConfigurationManager).setCompilationDatabase(project,
+				RELATIVE_DIR_PATH_BUILD_DEBUG);
+		// THEN the file has not been changed, because the user shall fix the errors first:
+		try (var inputStream = configFile.getContents()) {
+			var afterSet = new String(inputStream.readAllBytes());
+			assertEquals(beforeSet, afterSet);
+		}
+	}
+
+	/**
+	 * Test whether a ParserException will be thrown if the file contains invalid yaml syntax (here: missing })
+	 *
+	 * @throws IOException
+	 * @throws CoreException
+	 */
+	@Test
+	void testInvalidYamlSyntax2() throws IOException, CoreException {
+		// GIVEN an existing .clangd configuration file with invalid yaml syntax (missing }):
+		var configFile = createConfigFile(INVALID_YAML_SYNTAX_MISSING_BRACE, RELATIVE_DIR_PATH_BUILD_DEFAULT);
+		String beforeSet;
+		try (var inputStream = configFile.getContents()) {
+			beforeSet = new String(inputStream.readAllBytes());
+		}
+		// WHEN the ClangdConfigurationManager.setCompilationDatabasePath method gets called with a new cdb path "build/debug":
+		((ClangdConfigurationFileManager) clangdConfigurationManager).setCompilationDatabase(project,
+				RELATIVE_DIR_PATH_BUILD_DEBUG);
+		// THEN the file has not been changed, because the user shall fix the errors first:
+		try (var inputStream = configFile.getContents()) {
+			var afterSet = new String(inputStream.readAllBytes());
+			assertEquals(beforeSet, afterSet);
+		}
+	}
+
+}