GP-1076: Adding diagnostic messages, esp., "new session" to GDB connector.

Ghidra/Debug/Debugger-agent-gdb/src/main/java/agent/gdb/GdbInJvmDebuggerModelFactory.java

@@ -48,7 +48,7 @@ public class GdbInJvmDebuggerModelFactory implements DebuggerModelFactory {
 	public CompletableFuture<? extends DebuggerObjectModel> build() {
 		// TODO: Choose Linux or Windows pty based on host OS
 		GdbModelImpl model = new GdbModelImpl(new LinuxPtyFactory());
-		return model.startGDB(gdbCmd, new String[] {}).thenApply(__ -> model);
+		return model.startGDB(existing ? null : gdbCmd, new String[] {}).thenApply(__ -> model);
 	}
 
 	@Override

Ghidra/Debug/Debugger-agent-gdb/src/main/java/agent/gdb/GdbOverSshDebuggerModelFactory.java

@@ -22,7 +22,6 @@ import agent.gdb.pty.ssh.GhidraSshPtyFactory;
 import ghidra.dbg.DebuggerModelFactory;
 import ghidra.dbg.DebuggerObjectModel;
 import ghidra.dbg.util.ConfigurableFactory.FactoryDescription;
-import ghidra.dbg.util.ConfigurableFactory.FactoryOption;
 
 @FactoryDescription(
 	brief = "GNU gdb via SSH",
@@ -69,7 +68,7 @@ public class GdbOverSshDebuggerModelFactory implements DebuggerModelFactory {
 			factory.setUsername(username);
 			return new GdbModelImpl(factory);
 		}).thenCompose(model -> {
-			return model.startGDB(gdbCmd, new String[] {}).thenApply(__ -> model);
+			return model.startGDB(existing ? null : gdbCmd, new String[] {}).thenApply(__ -> model);
 		});
 	}
 

Ghidra/Debug/Debugger-agent-gdb/src/main/java/agent/gdb/manager/impl/GdbManagerImpl.java

@@ -15,13 +15,15 @@
  */
 package agent.gdb.manager.impl;
 
-import static ghidra.async.AsyncUtils.*;
+import static ghidra.async.AsyncUtils.loop;
 
 import java.io.*;
 import java.util.*;
 import java.util.concurrent.*;
 import java.util.concurrent.atomic.*;
 
+import javax.swing.JOptionPane;
+
 import org.apache.commons.lang3.exception.ExceptionUtils;
 import org.python.core.PyDictionary;
 import org.python.util.InteractiveConsole;
@@ -612,12 +614,20 @@ public class GdbManagerImpl implements GdbManager {
 		}
 		else {
 			Pty mi2Pty = ptyFactory.openpty();
-			Msg.info(this, "Agent is waiting for GDB/MI v2 interpreter at " +
+			String mi2PtyName = mi2Pty.getChild().nullSession();
-				mi2Pty.getChild().nullSession());
+			Msg.info(this, "Agent is waiting for GDB/MI v2 interpreter at " + mi2PtyName);
 			mi2Thread = new PtyThread(mi2Pty, Channel.STDOUT, Interpreter.MI2);
 			mi2Thread.setName("GDB Read MI2");
 
 			mi2Thread.start();
+
+			int choice = JOptionPane.showConfirmDialog(null,
+				"Please enter \"new-ui mi2 " + mi2PtyName + "\" in an existing gdb session. " +
+					"Alternatively, disable 'use existing session' to launch a new session.",
+				"Waiting for GDB/MI session", JOptionPane.OK_CANCEL_OPTION);
+			if (choice == JOptionPane.CANCEL_OPTION) {
+				terminate();
+			}
 		}
 	}
 

Ghidra/Debug/Debugger-agent-gdb/src/main/java/agent/gdb/pty/linux/LinuxPtyChild.java

@@ -24,6 +24,7 @@ import java.util.*;
 import agent.gdb.pty.PtyChild;
 import agent.gdb.pty.PtySession;
 import agent.gdb.pty.local.LocalProcessPtySession;
+import ghidra.util.Msg;
 
 public class LinuxPtyChild extends LinuxPtyEndpoint implements PtyChild {
 	private final String name;
@@ -81,8 +82,14 @@ public class LinuxPtyChild extends LinuxPtyEndpoint implements PtyChild {
 		}
 		builder.inheritIO();
 
+		try {
 			return new LocalProcessPtySession(builder.start());
 		}
+		catch (Exception e) {
+			Msg.error(this, "Could not start process with args " + args, e);
+			throw e;
+		}
+	}
 
 	protected PtySession sessionUsingPythonLeader(String[] args, Map<String, String> env)
 			throws IOException {

Ghidra/Debug/Debugger-agent-gdb/src/main/java/agent/gdb/pty/linux/LinuxPtySessionLeader.java

@@ -18,6 +18,7 @@ package agent.gdb.pty.linux;
 import java.util.List;
 import java.util.concurrent.Callable;
 
+import ghidra.util.Msg;
 import jnr.posix.POSIX;
 import jnr.posix.POSIXFactory;
 
@@ -80,6 +81,7 @@ public class LinuxPtySessionLeader {
 			checkErr(() -> LIB_POSIX.execv(subArgs.get(0), subArgs.toArray(new String[0])));
 		}
 		catch (Throwable t) {
+			Msg.error(this, "Could not execv with args " + subArgs, t);
 			try {
 				checkErr(() -> LIB_POSIX.dup2(bk, 2));
 			}

Ghidra/Debug/Debugger-agent-gdb/src/main/java/agent/gdb/pty/ssh/GhidraSshPtyFactory.java

@@ -24,6 +24,7 @@ import ch.ethz.ssh2.Connection;
 import ch.ethz.ssh2.KnownHosts;
 import docking.DockingWindowManager;
 import docking.widgets.PasswordDialog;
+import ghidra.util.Msg;
 import ghidra.util.exception.CancelledException;
 
 public class GhidraSshPtyFactory implements PtyFactory {
@@ -97,7 +98,8 @@ public class GhidraSshPtyFactory implements PtyFactory {
 				// TODO: Find an API that uses char[] so I can clear it!
 				String password = new String(promptPassword(hostname, "Password for " + username));
 				if (!sshConn.authenticateWithPassword(username, password)) {
-					throw new IOException("Authentication failed");
+					Msg.error(this, "SSH password authentication failed");
+					throw new IOException("SSH password authentication failed");
 				}
 			}
 			else {
@@ -108,14 +110,16 @@ public class GhidraSshPtyFactory implements PtyFactory {
 				}
 				String password = new String(promptPassword(hostname, "Password for " + pemFile));
 				if (!sshConn.authenticateWithPublicKey(username, pemFile, password)) {
-					throw new IOException("Authentication failed");
+					Msg.error(this, "SSH pukey authentication failed");
+					throw new IOException("SSH pukey authentication failed");
 				}
 			}
 			success = true;
 			return sshConn;
 		}
 		catch (CancelledException e) {
-			throw new IOException("User cancelled", e);
+			Msg.error(this, "SSH connection/authentication cancelled by user");
+			throw new IOException("SSH connection/authentication cancelled by user", e);
 		}
 		finally {
 			if (!success) {

Ghidra/Debug/Debugger-agent-gdb/src/main/java/agent/gdb/pty/ssh/SshPtyChild.java

@@ -49,7 +49,13 @@ public class SshPtyChild extends SshPtyEndpoint implements PtyChild {
 						.collect(Collectors.joining(" ")) +
 					" ";
 		String cmdStr = Stream.of(args).collect(Collectors.joining(" "));
+		try {
 			session.execCommand(envStr + cmdStr);
+		}
+		catch (Throwable t) {
+			Msg.error(this, "Could not execute remote command: " + envStr + cmdStr, t);
+			throw t;
+		}
 		return new SshPtySession(session);
 	}