Add support for launching Eclipse Process in a system terminal session

Currently processes are launched as a forked process without a terminal
session attached to them. Some features of processes require a terminal
session (e.g. autocompletion) and currently not work when running from
within eclipse (e.g. the gogo-shell).

This is an attempt to bring terminal session support to Eclipse to
support real terminal application similar to what is supported by
IntelliJ.

Author: laeubi

debug/org.eclipse.debug.core/META-INF/MANIFEST.MF

@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.debug.core; singleton:=true
-Bundle-Version: 3.22.100.qualifier
+Bundle-Version: 3.23.0.qualifier
 Bundle-Activator: org.eclipse.debug.core.DebugPlugin
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin

debug/org.eclipse.debug.core/core/org/eclipse/debug/core/DebugPlugin.java

@@ -22,9 +22,12 @@
 import java.nio.charset.StandardCharsets;
 import java.text.MessageFormat;
 import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.FactoryConfigurationError;
@@ -170,6 +173,14 @@ public class DebugPlugin extends Plugin {
 	 */
 	public static final String EXTENSION_POINT_PROCESS_FACTORIES = "processFactories"; //$NON-NLS-1$
 
+	/**
+	 * Simple identifier constant (value <code>"execFactories"</code>) for the
+	 * exec factories extension point.
+	 *
+	 * @since 3.23
+	 */
+	public static final String EXTENSION_POINT_EXEC_FACTORIES = "execFactories"; //$NON-NLS-1$
+
 	/**
 	 * Simple identifier constant (value <code>"logicalStructureTypes"</code>) for the
 	 * logical structure types extension point.
@@ -438,6 +449,11 @@ public class DebugPlugin extends Plugin {
 	 */
 	private HashMap<String, IConfigurationElement> fProcessFactories = null;
 
+	/**
+	 * List of exec factories.
+	 */
+	private List<ExecFactoryFacade> execFactories;
+
 	/**
 	 * Service tracker for the workspace service
 	 */
@@ -841,10 +857,13 @@ public static IProcess newProcess(ILaunch launch, Process process, String label)
 	 */
 	public static IProcess newProcess(ILaunch launch, Process process, String label, Map<String, String> attributes) {
 		ILaunchConfiguration config= launch.getLaunchConfiguration();
-		String processFactoryID= null;
+		String processFactoryID = null;
+		// FIXME hack for demo purpose we need an UI for the user to decide if a
+		// terminal
+		// is wanted
 		if (config != null) {
 			try {
-				processFactoryID= config.getAttribute(ATTR_PROCESS_FACTORY_ID, (String)null);
+				processFactoryID = config.getAttribute(ATTR_PROCESS_FACTORY_ID, "org.eclipse.debug.terminal.processFactory.cdt"); //$NON-NLS-1$
 			} catch (CoreException e) {
 			}
 		}
@@ -981,34 +1000,45 @@ public static Process exec(String[] cmdLine, File workingDirectory, String[] env
 	 * @since 3.14
 	 */
 	public static Process exec(String[] cmdLine, File workingDirectory, String[] envp, boolean mergeOutput) throws CoreException {
-		Process p = null;
+		List<ExecFactoryFacade> factories = DebugPlugin.getDefault().getExecFactories();
+		Optional<File> directory = shortenWindowsPath(workingDirectory);
+		Optional<Map<String, String>> envMap = Optional.ofNullable(envp).map(array -> {
+			Map<String, String> map = new LinkedHashMap<>();
+			for (String e : array) {
+				int index = e.indexOf('=');
+				if (index != -1) {
+					map.put(e.substring(0, index), e.substring(index + 1));
+				}
+			}
+			return Map.copyOf(map);
+		});
+		for (ExecFactoryFacade holder : factories) {
+			Optional<Process> exec = holder.exec(cmdLine.clone(), directory, envMap, mergeOutput);
+			if (exec.isPresent()) {
+				return exec.get();
+			}
+		}
 		try {
 			// starting with and without merged output could be done with the
 			// same process builder approach but since the handling of
 			// environment variables is slightly different between
 			// ProcessBuilder and Runtime.exec only the new option uses process
 			// builder to not break existing caller of this method
+
 			if (mergeOutput) {
 				ProcessBuilder pb = new ProcessBuilder(cmdLine);
-				if (workingDirectory != null) {
-					pb.directory(shortenWindowsPath(workingDirectory));
-				}
+				directory.ifPresent(pb::directory);
 				pb.redirectErrorStream(mergeOutput);
-				if (envp != null) {
+				if (envMap.isPresent()) {
 					Map<String, String> env = pb.environment();
 					env.clear();
-					for (String e : envp) {
-						int index = e.indexOf('=');
-						if (index != -1) {
-							env.put(e.substring(0, index), e.substring(index + 1));
-						}
-					}
+					env.putAll(envMap.get());
 				}
-				p = pb.start();
-			} else if (workingDirectory == null) {
-				p = Runtime.getRuntime().exec(cmdLine, envp);
+				return pb.start();
+			} else if (directory.isEmpty()) {
+				return Runtime.getRuntime().exec(cmdLine, envp);
 			} else {
-				p = Runtime.getRuntime().exec(cmdLine, envp, shortenWindowsPath(workingDirectory));
+				return Runtime.getRuntime().exec(cmdLine, envp, directory.get());
 			}
 		} catch (IOException e) {
 			Status status = new Status(IStatus.ERROR, getUniqueIdentifier(), ERROR, DebugCoreMessages.DebugPlugin_0, e);
@@ -1021,18 +1051,18 @@ public static Process exec(String[] cmdLine, File workingDirectory, String[] env
 			if (handler != null) {
 				Object result = handler.handleStatus(status, null);
 				if (result instanceof Boolean resultValue && resultValue) {
-					p = exec(cmdLine, null);
+					return exec(cmdLine, null);
 				}
 			}
 		}
-		return p;
+		return null;
 	}
 
 	// https://learn.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation
 	private static final int WINDOWS_MAX_PATH = 258;
 
-	private static File shortenWindowsPath(File path) {
-		if (path.getPath().length() > WINDOWS_MAX_PATH && Platform.OS.isWindows()) {
+	private static Optional<File> shortenWindowsPath(File path) {
+		if (path != null && path.getPath().length() > WINDOWS_MAX_PATH && Platform.OS.isWindows()) {
 			// When spawning new processes on Windows, there is no uniform way
 			// to use long working directory paths that exceed the default path
 			// length limit, like for example using the raw path prefix '\\?\'
@@ -1042,12 +1072,12 @@ private static File shortenWindowsPath(File path) {
 			@SuppressWarnings("restriction")
 			String shortPath = org.eclipse.core.internal.filesystem.local.Win32Handler.getShortPathName(path.toString());
 			if (shortPath != null) {
-				return new File(shortPath);
+				return Optional.of(new File(shortPath));
 			} else {
 				log(Status.warning("Working directory of process to create exceeds Window's MAX_PATH limit and shortening the path failed.")); //$NON-NLS-1$
 			}
 		}
-		return path;
+		return Optional.ofNullable(path);
 	}
 
 	/**
@@ -1189,6 +1219,39 @@ private void initializeProcessFactories() {
 		}
 	}
 
+	private synchronized List<ExecFactoryFacade> getExecFactories() {
+		if (execFactories == null) {
+			IExtensionPoint extensionPoint = Platform.getExtensionRegistry().getExtensionPoint(DebugPlugin.PI_DEBUG_CORE, EXTENSION_POINT_EXEC_FACTORIES);
+			IConfigurationElement[] infos = extensionPoint.getConfigurationElements();
+			List<ExecFactoryFacade> list = new ArrayList<>();
+			for (IConfigurationElement configurationElement : infos) {
+				String clz = configurationElement.getAttribute("class"); //$NON-NLS-1$
+				if (clz != null) {
+					int priority;
+					String attribute = configurationElement.getAttribute("priority"); //$NON-NLS-1$
+					if (attribute == null) {
+						priority = 0;
+					}
+					try {
+						priority = Integer.parseInt(attribute);
+					} catch (NumberFormatException e) {
+						log(new Status(IStatus.ERROR, DebugPlugin.PI_DEBUG_CORE, ERROR, MessageFormat.format(DebugCoreMessages.DebugPlugin_invalid_exec_factory, new Object[] {
+								configurationElement.getContributor().getName() }), null));
+						priority = 0;
+					}
+					list.add(new ExecFactoryFacade(configurationElement, priority));
+				} else {
+					String badDefiner = configurationElement.getContributor().getName();
+					log(new Status(IStatus.ERROR, DebugPlugin.PI_DEBUG_CORE, ERROR, MessageFormat.format(DebugCoreMessages.DebugPlugin_invalid_exec_factory, new Object[] {
+							badDefiner }), null));
+				}
+			}
+			list.sort(Comparator.comparingInt(ExecFactoryFacade::getPriority).reversed());
+			execFactories = List.copyOf(list);
+		}
+		return execFactories;
+	}
+
 	private void invalidStatusHandler(Exception e, String id) {
 		log(new Status(IStatus.ERROR, DebugPlugin.PI_DEBUG_CORE, ERROR, MessageFormat.format(DebugCoreMessages.DebugPlugin_5, new Object[] { id }), e));
 	}
@@ -1221,6 +1284,34 @@ public boolean equals(Object obj) {
 		}
 	}
 
+	private class ExecFactoryFacade implements ExecFactory {
+
+		private IConfigurationElement element;
+		private int priority;
+
+		ExecFactoryFacade(IConfigurationElement element, int priority) {
+			this.element = element;
+			this.priority = priority;
+		}
+
+		public int getPriority() {
+			return priority;
+		}
+
+		@Override
+		public Optional<Process> exec(String[] cmdLine, Optional<File> workingDirectory, Optional<Map<String, String>> environment, boolean mergeOutput) throws CoreException {
+			ExecFactory extension;
+			try {
+				extension = (ExecFactory) element.createExecutableExtension(IConfigurationElementConstants.CLASS);
+			} catch (CoreException e) {
+				log(e);
+				return Optional.empty();
+			}
+			return extension.exec(cmdLine, workingDirectory, environment, mergeOutput);
+		}
+
+	}
+
 	/**
 	 * Executes runnables after event dispatch is complete.
 	 *

debug/org.eclipse.debug.core/core/org/eclipse/debug/core/ExecFactory.java

@@ -0,0 +1,50 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Christoph Läubrich and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Christoph Läubrich - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.debug.core;
+
+import java.io.File;
+import java.util.Map;
+import java.util.Optional;
+
+import org.eclipse.core.runtime.CoreException;
+
+/**
+ * A {@link ExecFactory} can be used to control how Eclipse forks a new
+ * {@link Process}.
+ *
+ * @since 3.23
+ */
+public interface ExecFactory {
+
+	/**
+	 * Executes the given command with the provided working directory and
+	 * environment
+	 *
+	 * @param cmdLine the commandline to execute
+	 * @param workingDirectory an optional working directory to be used
+	 *            otherwise the process factory must use its default
+	 * @param environment the environment to use, if empty the process factory
+	 *            must use its defaults
+	 * @param mergeOutput <code>true</code> if standard error and standard out
+	 *            should be merged
+	 * @return an {@link Optional} describing the new process created, if an
+	 *         empty {@link Optional} is returned it is assumed that this
+	 *         factory is not capable of executing the provided command with the
+	 *         requested settings
+	 * @throws CoreException if the factory is capable of execution but the
+	 *             creation of a process itself has failed
+	 */
+	Optional<Process> exec(String[] cmdLine, Optional<File> workingDirectory, Optional<Map<String, String>> environment, boolean mergeOutput) throws CoreException;
+
+}

debug/org.eclipse.debug.core/core/org/eclipse/debug/internal/core/DebugCoreMessages.java

@@ -31,6 +31,8 @@ public class DebugCoreMessages extends NLS {
 	public static String DebugPlugin_2;
 	public static String DebugPlugin_3;
 	public static String DebugPlugin_4;
+	public static String DebugPlugin_invalid_exec_factory;
+	public static String DebugPlugin_invalid_exec_factory_priority;
 	public static String DebugPlugin_5;
 	public static String DebugPlugin_6;
 	public static String DebugPlugin_7;

debug/org.eclipse.debug.core/core/org/eclipse/debug/internal/core/DebugCoreMessages.properties

@@ -26,6 +26,8 @@ DebugPlugin_0=Exception occurred executing command line.
 DebugPlugin_2=Internal message logged from Debug Core: {0}
 DebugPlugin_3=Error logged from Debug Core: 
 DebugPlugin_4=Invalid process factory extension contributed by {0}; id: {1}
+DebugPlugin_invalid_exec_factory=Invalid exec factory extension contributed by {0}, required class attribute is missing
+DebugPlugin_invalid_exec_factory_priority=Invalid exec factory extension contributed by {0}, optional priority attribute is not a number
 DebugPlugin_5=Invalid status handler extension: {0}
 DebugPlugin_6=An exception occurred in asynchronous runnable.
 DebugPlugin_7=An exception occurred while filtering debug events.

debug/org.eclipse.debug.core/plugin.properties

@@ -26,6 +26,7 @@ launchDelegatesExtensionPointName=Launch Delegates
 breakpointImportParticipantsExtensionPoint.name = Breakpoint Import Participant
 watchExpressionDelegatesName= Watch Expression Delegates
 processFactoriesExtensionPointName=Process Factories
+execFactoriesExtensionPointName=Exec Factories
 logicalStructureTypesExtensionPointName=Logical Structure Types
 logicalStructureProvidersExtensionPointName=Logical Structure Providers
 stepFiltersExtensionPointName=Step Filters

debug/org.eclipse.debug.core/plugin.xml

@@ -28,6 +28,7 @@
    <extension-point id="statusHandlers" name="%statusHandlerExtensionPointName" schema="schema/statusHandlers.exsd"/>
    <extension-point id="watchExpressionDelegates" name="%watchExpressionDelegatesName" schema="schema/watchExpressionDelegates.exsd"/>
    <extension-point id="processFactories" name="%processFactoriesExtensionPointName" schema="schema/processFactories.exsd"/>
+   <extension-point id="execFactories" name="%execFactoriesExtensionPointName" schema="schema/execFactories.exsd"/>
    <extension-point id="logicalStructureTypes" name="%logicalStructureTypesExtensionPointName" schema="schema/logicalStructureTypes.exsd"/>
    <extension-point id="sourceContainerTypes" name="%sourceContainerTypesName" schema="schema/sourceContainerTypes.exsd"/>
    <extension-point id="sourcePathComputers" name="%sourcePathComputersName" schema="schema/sourcePathComputers.exsd"/>