GP-0 Improved process error handling for Decompiler and GNU Demangler.

Corrected minor GNU Demangler demangler command and script issues.

Ghidra/Features/Base/ghidra_scripts/DemangleSymbolScript.java

@@ -104,7 +104,12 @@ public class DemangleSymbolScript extends GhidraScript {
 			println("Successfully demangled\n" + name + '\n' + cmd.getResult());
 		}
 		else {
-			println("Failed to demangle\n" + name + '\n' + cmd.getStatusMsg());
+			String statusMsg = cmd.getStatusMsg();
+			String msg = "Failed to demangle\n" + name;
+			if (statusMsg != null) {
+				msg += "\n" + statusMsg;
+			}
+			println(msg);
 		}
 	}
 }

Ghidra/Features/Decompiler/src/main/java/ghidra/app/cmd/function/DecompilerParallelConventionAnalysisCmd.java

@@ -59,7 +59,12 @@ public class DecompilerParallelConventionAnalysisCmd extends BackgroundCommand<P
 		newInterface.setOptions(opts);
 
 		if (!newInterface.openProgram(program)) {
-			throw new IOException("Unable to create decompiler for program: " + program);
+			String msg = "Unable to create decompiler for program: " + program;
+			String lastMessage = newInterface.getLastMessage();
+			if (lastMessage != null) {
+				msg += "\n" + lastMessage;
+			}
+			throw new IOException(msg);
 		}
 
 		return newInterface;

Ghidra/Features/Decompiler/src/main/java/ghidra/app/decompiler/DecompileProcess.java

@@ -19,6 +19,7 @@ import static ghidra.program.model.pcode.AttributeId.*;
 import static ghidra.program.model.pcode.ElementId.*;
 
 import java.io.*;
+import java.util.concurrent.TimeUnit;
 
 import ghidra.program.model.address.Address;
 import ghidra.program.model.lang.InjectPayload;
@@ -47,6 +48,8 @@ import ghidra.util.timer.GTimerMonitor;
 
 public class DecompileProcess {
 	
+	private static boolean errorDisplayed = false; // launch failure previously displayed
+
 	//	public static DecompileProcess decompProcess = null;
 	private final static byte[] command_start = { 0, 0, 1, 2 };
 	private final static byte[] command_end = { 0, 0, 1, 3 };
@@ -104,6 +107,14 @@ public class DecompileProcess {
 		stringDecoder = new StringIngest();
 	}
 	
+	private static synchronized boolean getAndSetErrorDisplayed() {
+		boolean b = errorDisplayed;
+		if (!b) {
+			errorDisplayed = true;
+		}
+		return b;
+	}
+
 	public void dispose() {
 		if (disposestate != DisposeState.NOT_DISPOSED) {
 			return;
@@ -133,19 +144,46 @@ public class DecompileProcess {
 		if (exepath == null || exepath.length == 0 || exepath[0] == null) {
 			throw new IOException("Could not find decompiler executable");
 		}
+		IOException exc = null;
+		String err = "";
+		statusGood = false;
 		try {
 			nativeProcess = runtime.exec(exepath);
-
+			// Give process time to load and report possible error
+			nativeProcess.waitFor(200, TimeUnit.MILLISECONDS);
 			nativeIn = nativeProcess.getInputStream();
 			nativeOut = nativeProcess.getOutputStream();
-			statusGood = true;
+			statusGood = nativeProcess.isAlive();
+			if (!statusGood) {
+				err = new String(nativeProcess.getErrorStream().readAllBytes());
+				nativeProcess.destroy();          			
+				nativeProcess = null;
+			}
 		}
 		catch (IOException e) {
-			disposestate = DisposeState.DISPOSED_ON_STARTUP_FAILURE;
-			statusGood = false;
-			Msg.showError(this, null, "Problem launching decompiler",
-				"Please report this stack trace to the Ghidra Team", e);
-			throw e;
+			exc = e;
+		}
+		catch (InterruptedException e) {
+			// ignore
+		}
+		finally {
+			if (!statusGood) {
+				disposestate = DisposeState.DISPOSED_ON_STARTUP_FAILURE;
+				if (!getAndSetErrorDisplayed()) {
+					String errorDetail = err;
+					if (exc != null) {
+						errorDetail = exc.getMessage() + "\n" + errorDetail;
+					}
+					errorDetail = "Decompiler executable may not be compatible with your system and may need to be rebuilt.\n" +
+							"(see InstallationGuide.html, 'Building Native Components').\n\n" +
+							errorDetail;		
+					Msg.showError(this, null, "Failed to launch Decompiler process", errorDetail);
+				}
+				if (exc == null) {
+					throw new IOException("Decompiler process failed to launch (see log for details)");
+				}
+				throw exc;
+			}
 		}
 	}
 

Ghidra/Features/Decompiler/src/main/java/ghidra/app/decompiler/DecompileProcessFactory.java

@@ -31,6 +31,14 @@ public class DecompileProcessFactory {
 
 	private static boolean errorDisplayed = false;
 	
+	private static synchronized boolean getAndSetErrorDisplayed() {
+		boolean b = errorDisplayed;
+		if (!b) {
+			errorDisplayed = true;
+		}
+		return b;
+	}
+
 	public synchronized static DecompileProcess get() {
 		getExePath();
 		DecompileProcess currentProcess = new DecompileProcess(exepath);
@@ -59,9 +67,8 @@ public class DecompileProcessFactory {
 			exepath = file.getAbsolutePath();
 		}
 		catch (OSFileNotFoundException e) {
-			if (!errorDisplayed) {
-				errorDisplayed = true;
-				Msg.showError(DecompileProcessFactory.class, null, "Decompiler missing",
+			if (!getAndSetErrorDisplayed()) {
+				Msg.showError(DecompileProcessFactory.class, null, "Decompiler Not Found",
 					e.getMessage());
 			}
 		}

Ghidra/Features/GnuDemangler/src/main/java/ghidra/app/util/demangler/gnu/GnuDemangler.java

@@ -196,6 +196,12 @@ public class GnuDemangler implements Demangler {
 
 		// This is the current list of known demangler start patterns.  Add to this list if we
 		// find any other known GNU start patterns.
+		if (mangled.startsWith(GLOBAL_PREFIX)) {
+			int index = mangled.indexOf("_Z");
+			if (index > 0) {
+				return false;
+			}
+		}
 		if (mangled.startsWith("_Z")) {
 			return false;
 		}

Ghidra/Features/GnuDemangler/src/main/java/ghidra/app/util/demangler/gnu/GnuDemanglerNativeProcess.java

@@ -18,6 +18,7 @@ package ghidra.app.util.demangler.gnu;
 import java.io.*;
 import java.nio.charset.Charset;
 import java.util.*;
+import java.util.concurrent.TimeUnit;
 
 import org.apache.commons.io.FilenameUtils;
 import org.apache.commons.io.IOUtils;
@@ -25,6 +26,7 @@ import org.apache.commons.lang3.ArrayUtils;
 import org.apache.commons.lang3.StringUtils;
 
 import ghidra.framework.*;
+import ghidra.util.Msg;
 
 /**
  * A class that allows for the reuse of native demangler executable processes.  This class will
@@ -38,6 +40,16 @@ public class GnuDemanglerNativeProcess {
 	private static final Map<String, GnuDemanglerNativeProcess> processesByName =
 		new HashMap<>();
 	
+	private static boolean errorDisplayed = false;
+	
+	private static synchronized boolean getAndSetErrorDisplayed() {
+		boolean b = errorDisplayed;
+		if (!b) {
+			errorDisplayed = true;
+		}
+		return b;
+	}
+
 	private String applicationName;
 	private String options;
 
@@ -153,16 +165,51 @@ public class GnuDemanglerNativeProcess {
 	private void createProcess() throws IOException {
 
 		String[] command = buildCommand();
-		process = Runtime.getRuntime().exec(command);
-
-		InputStream in = process.getInputStream();
-		OutputStream out = process.getOutputStream();
-		reader = new BufferedReader(new InputStreamReader(in));
-		writer = new PrintWriter(out);
+		IOException exc = null;
+		String err = "";
+		isDisposed = true;
+		try {
+			process = Runtime.getRuntime().exec(command);
+			// Give process time to load and report possible error
+			process.waitFor(200, TimeUnit.MILLISECONDS);
+			InputStream in = process.getInputStream();
+			OutputStream out = process.getOutputStream();
+			reader = new BufferedReader(new InputStreamReader(in));
+			writer = new PrintWriter(out);
+			isDisposed = !process.isAlive();
+			if (isDisposed) {
+				err = new String(process.getErrorStream().readAllBytes());
+				process.destroy();          			
+				process = null;
+			}
+		}
+		catch (IOException e) {
+			exc = e;
+		}
+		catch (InterruptedException e) {
+			// ignore
+		}
+		finally {
+			if (isDisposed) {
+				if (!getAndSetErrorDisplayed()) {
+					String errorDetail = err;
+					if (exc != null) {
+						errorDetail = exc.getMessage() + "\n" + errorDetail;
+					}
+					errorDetail = "GNU Demangler executable may not be compatible with your system and may need to be rebuilt.\n" +
+							"(see InstallationGuide.html, 'Building Native Components').\n\n" +
+							errorDetail;		
+					Msg.showError(this, null, "Failed to launch GNU Demangler process", errorDetail);
+				}
+				if (exc == null) {
+					throw new IOException("GNU Demangler process failed to launch (see log for details)");
+				}
+				throw exc;
+			}
+		}
 		
 		checkForError(command);
 
-		isDisposed = false;
 		String key = getKey(applicationName, options);
 		processesByName.put(key, this);
 	}