GP-1474: Display emulator's decoded instruction in PcodeStepper

Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/gui/pcode/DebuggerPcodeStepperProvider.java

@@ -52,6 +52,7 @@ import ghidra.pcode.exec.PcodeExecutorState;
 import ghidra.pcode.exec.PcodeFrame;
 import ghidra.program.model.data.DataType;
 import ghidra.program.model.lang.Language;
+import ghidra.program.model.listing.Instruction;
 import ghidra.program.model.pcode.PcodeOp;
 import ghidra.program.model.pcode.Varnode;
 import ghidra.trace.model.Trace;
@@ -347,10 +348,11 @@ public class DebuggerPcodeStepperProvider extends ComponentProviderAdapter {
 
 	GhidraTable uniqueTable;
 	UniqueTableModel uniqueTableModel = new UniqueTableModel();
-	private GhidraTableFilterPanel<UniqueRow> uniqueFilterPanel;
+	GhidraTableFilterPanel<UniqueRow> uniqueFilterPanel;
 
 	GhidraTable pcodeTable;
 	PcodeTableModel pcodeTableModel = new PcodeTableModel();
+	JLabel instructionLabel;
 	// No filter panel on p-code
 
 	DockingAction actionStepBackward;
@@ -457,6 +459,8 @@ public class DebuggerPcodeStepperProvider extends ComponentProviderAdapter {
 		JPanel pcodePanel = new JPanel(new BorderLayout());
 		pcodeTable = new GhidraTable(pcodeTableModel);
 		pcodePanel.add(new JScrollPane(pcodeTable));
+		instructionLabel = new JLabel();
+		pcodePanel.add(instructionLabel, BorderLayout.NORTH);
 		mainPanel.setLeftComponent(pcodePanel);
 
 		JPanel uniquePanel = new JPanel(new BorderLayout());
@@ -620,6 +624,9 @@ public class DebuggerPcodeStepperProvider extends ComponentProviderAdapter {
 	}
 
 	protected void doLoadPcodeFrame() {
+		if (instructionLabel != null) {
+			instructionLabel.setText("(no instruction)");
+		}
 		if (emulationService == null) {
 			return;
 		}
@@ -660,6 +667,13 @@ public class DebuggerPcodeStepperProvider extends ComponentProviderAdapter {
 			populateSingleton(EnumPcodeRow.DECODE);
 			return;
 		}
+		Instruction instruction = thread.getInstruction();
+		if (instruction == null) {
+			instructionLabel.setText("(no instruction)");
+		}
+		else {
+			instructionLabel.setText(instruction.toString());
+		}
 		PcodeFrame frame = thread.getFrame();
 		if (frame == null) {
 			/**

Ghidra/Debug/Framework-TraceModeling/src/test/java/ghidra/trace/model/time/schedule/TraceScheduleTest.java

@@ -28,6 +28,7 @@ import ghidra.pcode.emu.*;
 import ghidra.pcode.exec.*;
 import ghidra.program.model.address.Address;
 import ghidra.program.model.lang.*;
+import ghidra.program.model.listing.Instruction;
 import ghidra.test.AbstractGhidraHeadlessIntegrationTest;
 import ghidra.test.ToyProgramBuilder;
 import ghidra.trace.database.ToyDBTraceBuilder;
@@ -333,6 +334,11 @@ public class TraceScheduleTest extends AbstractGhidraHeadlessIntegrationTest {
 		public PcodeFrame getFrame() {
 			return null;
 		}
+		
+		@Override
+		public Instruction getInstruction() {
+			return null;
+		}
 
 		@Override
 		public void executeInstruction() {

Ghidra/Debug/ProposedUtils/src/main/java/ghidra/pcode/emu/DefaultPcodeThread.java

@@ -284,6 +284,7 @@ public class DefaultPcodeThread<T> implements PcodeThread<T> {
 		}
 		postExecuteInstruction();
 		frame = null;
+		instruction = null;
 	}
 
 	@Override
@@ -291,6 +292,11 @@ public class DefaultPcodeThread<T> implements PcodeThread<T> {
 		return frame;
 	}
 
+	@Override
+	public Instruction getInstruction() {
+		return instruction;
+	}
+
 	protected void assertCompletedInstruction() {
 		if (frame != null) {
 			throw new IllegalStateException("The current instruction or inject has not finished.");

Ghidra/Debug/ProposedUtils/src/main/java/ghidra/pcode/emu/PcodeThread.java

@@ -22,6 +22,7 @@ import ghidra.pcode.emu.DefaultPcodeThread.SleighEmulationLibrary;
 import ghidra.pcode.exec.*;
 import ghidra.program.model.address.Address;
 import ghidra.program.model.lang.RegisterValue;
+import ghidra.program.model.listing.Instruction;
 
 /**
  * An emulated thread of execution
@@ -157,6 +158,13 @@ public interface PcodeThread<T> {
 	 */
 	PcodeFrame getFrame();
 
+	/**
+	 * Get the current decoded instruction, if applicable
+	 * 
+	 * @return the instruction
+	 */
+	Instruction getInstruction();
+
 	/**
 	 * Execute the next instruction, ignoring injects
 	 *