implement reverse execution for gdb

src/MICore/CommandFactories/MICommandFactory.cs

@@ -4,12 +4,10 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Globalization;
 using System.Threading.Tasks;
-using System.IO;
 using System.Text;
-using System.Collections.ObjectModel;
 using System.Linq;
-using System.Globalization;
 using Microsoft.VisualStudio.Debugger.Interop;
 
 namespace MICore
@@ -212,33 +210,43 @@ public async Task<ValueListValue> StackListVariables(PrintValue printValues, int
 
         #region Program Execution
 
-        public async Task ExecStep(int threadId, ResultClass resultClass = ResultClass.running)
+        public async Task ExecStep(int threadId, bool forward = true, ResultClass resultClass = ResultClass.running)
         {
             string command = "-exec-step";
+            if (!forward)
+                command += " --reverse";
             await ThreadFrameCmdAsync(command, resultClass, threadId, 0);
         }
 
-        public async Task ExecNext(int threadId, ResultClass resultClass = ResultClass.running)
+        public async Task ExecNext(int threadId, bool forward = true, ResultClass resultClass = ResultClass.running)
         {
             string command = "-exec-next";
+            if (!forward)
+                command += " --reverse";
             await ThreadFrameCmdAsync(command, resultClass, threadId, 0);
         }
 
-        public async Task ExecFinish(int threadId, ResultClass resultClass = ResultClass.running)
+        public async Task ExecFinish(int threadId, bool forward = true, ResultClass resultClass = ResultClass.running)
         {
             string command = "-exec-finish";
+            if (!forward)
+                command += " --reverse";
             await ThreadFrameCmdAsync(command, resultClass, threadId, 0);
         }
 
-        public async Task ExecStepInstruction(int threadId, ResultClass resultClass = ResultClass.running)
+        public async Task ExecStepInstruction(int threadId, bool forward = true, ResultClass resultClass = ResultClass.running)
         {
             string command = "-exec-step-instruction";
+            if (!forward)
+                command += " --reverse";
             await ThreadFrameCmdAsync(command, resultClass, threadId, 0);
         }
 
-        public async Task ExecNextInstruction(int threadId, ResultClass resultClass = ResultClass.running)
+        public async Task ExecNextInstruction(int threadId, bool forward = true, ResultClass resultClass = ResultClass.running)
         {
             string command = "-exec-next-instruction";
+            if (!forward)
+                command += " --reverse";
             await ThreadFrameCmdAsync(command, resultClass, threadId, 0);
         }
 
@@ -254,9 +262,11 @@ public virtual async Task ExecRun()
         /// <summary>
         /// Continues running the target process
         /// </summary>
-        public async Task ExecContinue()
+        public async Task ExecContinue(bool forward = true)
         {
             string command = "-exec-continue";
+            if (!forward)
+                command += " --reverse";
             await _debugger.CmdAsync(command, ResultClass.running);
         }
 
@@ -686,6 +696,8 @@ public virtual bool CanDetach()
             return true;
         }
 
+        abstract public Task<string[]> GetTargetFeatures();
+
         abstract public Task<List<ulong>> StartAddressesForLine(string file, uint line);
 
         /// <summary>

src/MICore/CommandFactories/gdb.cs

@@ -1,19 +1,15 @@
-// Copyright (c) Microsoft. All rights reserved.
+// Copyright (c) Microsoft. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Threading.Tasks;
 using System.IO;
-using System.Text;
-using System.Collections.ObjectModel;
-using System.Linq;
 using System.Globalization;
 
 namespace MICore
 {
-    internal class GdbMICommandFactory : MICommandFactory
+    internal sealed class GdbMICommandFactory : MICommandFactory
     {
         private int _currentThreadId = 0;
         private uint _currentFrameLevel = 0;
@@ -183,6 +179,12 @@ public override async Task<List<ulong>> StartAddressesForLine(string file, uint
             return addresses;
         }
 
+        public override async Task<string[]> GetTargetFeatures()
+        {
+            Results results = await _debugger.CmdAsync("-list-target-features", ResultClass.done);
+            return results.Find<ValueListValue>("features").AsStrings;
+        }
+
         public override async Task EnableTargetAsyncOption()
         {
             // Linux attach TODO: GDB will fail this command when attaching. This is worked around

src/MICore/CommandFactories/lldb.cs

@@ -3,18 +3,15 @@
 
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Threading.Tasks;
 using System.IO;
 using System.Text;
-using System.Collections.ObjectModel;
-using System.Linq;
 using System.Globalization;
 using Microsoft.VisualStudio.Debugger.Interop;
 
 namespace MICore
 {
-    internal class LlldbMICommandFactory : MICommandFactory
+    internal sealed class LlldbMICommandFactory : MICommandFactory
     {
         public override string Name
         {
@@ -119,6 +116,11 @@ public override Task EnableTargetAsyncOption()
             return Task.FromResult((object)null);
         }
 
+        public override Task<string[]> GetTargetFeatures()
+        {
+            return Task.FromResult(new string[0]);
+        }
+
         public override string GetTargetArchitectureCommand()
         {
             return "platform status";

src/MICore/Debugger.cs

@@ -44,6 +44,8 @@ public class Debugger : ITransportCallback
         public event EventHandler ThreadCreatedEvent;
         public event EventHandler ThreadExitedEvent;
         public event EventHandler ThreadGroupExitedEvent;
+        public event EventHandler RecordStartedEvent;
+        public event EventHandler RecordStoppedEvent;
         public event EventHandler<ResultEventArgs> TelemetryEvent;
         private int _exiting;
         public ProcessState ProcessState { get; private set; }
@@ -1446,6 +1448,16 @@ private void OnNotificationOutput(string cmd)
                 results = _miResults.ParseResultList(cmd.Substring("thread-exited,".Length));
                 ThreadExitedEvent(this, new ResultEventArgs(results, 0));
             }
+            else if (cmd.StartsWith("record-started,", StringComparison.Ordinal))
+            {
+                results = _miResults.ParseResultList(cmd.Substring("record-started,".Length));
+                RecordStartedEvent(this, new ResultEventArgs(results, 0));
+            }
+            else if (cmd.StartsWith("record-stopped,", StringComparison.Ordinal))
+            {
+                results = _miResults.ParseResultList(cmd.Substring("record-stopped,".Length));
+                RecordStoppedEvent(this, new ResultEventArgs(results, 0));
+            }
             else if (cmd.StartsWith("telemetry,", StringComparison.Ordinal))
             {
                 results = _miResults.ParseResultList(cmd.Substring("telemetry,".Length));

src/MIDebugEngine/AD7.Impl/AD7Engine.cs

@@ -3,8 +3,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Text;
-using System.Runtime.ExceptionServices;
 using Microsoft.VisualStudio.Debugger.Interop;
 using Microsoft.VisualStudio.Debugger.Interop.UnixPortSupplier;
 using System.Diagnostics;
@@ -35,7 +33,7 @@ namespace Microsoft.MIDebugEngine
 
     [System.Runtime.InteropServices.ComVisible(true)]
     [System.Runtime.InteropServices.Guid("0fc2f352-2fc1-4f80-8736-51cd1ab28f16")]
-    sealed public class AD7Engine : IDebugEngine2, IDebugEngineLaunch2, IDebugEngine3, IDebugProgram3, IDebugEngineProgram2, IDebugMemoryBytes2, IDebugEngine110, IDebugProgramDAP, IDebugMemoryBytesDAP, IDisposable
+    sealed public class AD7Engine : IDebugEngine2, IDebugEngineLaunch2, IDebugEngine3, IDebugProgram3, IDebugEngineProgram2, IDebugReversibleEngineProgram160, IDebugMemoryBytes2, IDebugEngine110, IDebugProgramDAP, IDebugMemoryBytesDAP, IDisposable
     {
         // used to send events to the debugger. Some examples of these events are thread create, exception thrown, module load.
         private EngineCallback _engineCallback;
@@ -171,6 +169,7 @@ internal bool ProgramCreateEventSent
             get;
             private set;
         }
+        public ExecuteDirection ExecutionDirection { get; private set; }
 
         public string GetAddressDescription(ulong ip)
         {
@@ -778,11 +777,11 @@ public int Continue(IDebugThread2 pThread)
             {
                 if (_pollThread.IsPollThread())
                 {
-                    _debuggedProcess.Continue(thread?.GetDebuggedThread());
+                    _debuggedProcess.Continue(thread?.GetDebuggedThread(), ExecutionDirection);
                 }
                 else
                 {
-                    _pollThread.RunOperation(() => _debuggedProcess.Continue(thread?.GetDebuggedThread()));
+                    _pollThread.RunOperation(() => _debuggedProcess.Continue(thread?.GetDebuggedThread(), ExecutionDirection));
                 }
             }
             catch (InvalidCoreDumpOperationException)
@@ -973,7 +972,7 @@ public int Step(IDebugThread2 pThread, enum_STEPKIND kind, enum_STEPUNIT unit)
                     return Constants.E_FAIL;
                 }
 
-                _debuggedProcess.WorkerThread.RunOperation(() => _debuggedProcess.Step(thread.GetDebuggedThread().Id, kind, unit));
+                _debuggedProcess.WorkerThread.RunOperation(() => _debuggedProcess.Step(thread.GetDebuggedThread().Id, kind, unit, ExecutionDirection));
             }
             catch (InvalidCoreDumpOperationException)
             {
@@ -1061,6 +1060,19 @@ public int WatchForThreadStep(IDebugProgram2 pOriginatingProgram, uint dwTid, in
 
         #endregion
 
+        #region IDebugEngineProgram2 Members
+        int IDebugReversibleEngineProgram160.CanReverse()
+        {
+            return DebuggedProcess.TargetFeatures.Contains("reverse") ? Constants.S_OK : Constants.S_FALSE;
+        }
+
+        int IDebugReversibleEngineProgram160.SetExecuteDirection(ExecuteDirection ExecuteDirection)
+        {
+            ExecutionDirection = ExecuteDirection;
+            return Constants.S_OK;
+        }
+        #endregion
+
         #region IDebugMemoryBytes2 Members
 
         public int GetSize(out ulong pqwSize)