From 569d01823ed846f51e2669840055ccc56a725eb1 Mon Sep 17 00:00:00 2001
From: merry <git@mary.rs>
Date: Tue, 8 Feb 2022 19:00:47 +0000
Subject: [PATCH] ARMeilleure: Add debuggable CPU loop

# Conflicts:
#	src/ARMeilleure/Optimizations.cs
#	src/ARMeilleure/Translation/ArmEmitterContext.cs
---
 src/ARMeilleure/Optimizations.cs          |  1 +
 src/ARMeilleure/Translation/Translator.cs | 35 +++++++++++++++++++----
 2 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/src/ARMeilleure/Optimizations.cs b/src/ARMeilleure/Optimizations.cs
index 8fe478e47..3cc8acc8d 100644
--- a/src/ARMeilleure/Optimizations.cs
+++ b/src/ARMeilleure/Optimizations.cs
@@ -9,6 +9,7 @@ namespace ARMeilleure
 
         public static bool AllowLcqInFunctionTable { get; set; } = true;
         public static bool UseUnmanagedDispatchLoop { get; set; } = true;
+        public static bool EnableDebugging          { get; set; } = false;
 
         public static bool UseAdvSimdIfAvailable { get; set; } = true;
         public static bool UseArm64AesIfAvailable { get; set; } = true;
diff --git a/src/ARMeilleure/Translation/Translator.cs b/src/ARMeilleure/Translation/Translator.cs
index 014b12035..410444c78 100644
--- a/src/ARMeilleure/Translation/Translator.cs
+++ b/src/ARMeilleure/Translation/Translator.cs
@@ -140,7 +140,33 @@ namespace ARMeilleure.Translation
 
             NativeInterface.RegisterThread(context, Memory, this);
 
-            if (Optimizations.UseUnmanagedDispatchLoop)
+            if (Optimizations.EnableDebugging)
+            {
+                context.DebugPc = address;
+                do
+                {
+                    context.DebugPc = ExecuteSingle(context, context.DebugPc);
+
+                    while (context._debugState != (int)DebugState.Running)
+                    {
+                        Interlocked.CompareExchange(ref context._debugState, (int)DebugState.Stopped, (int)DebugState.Stopping);
+                        context._debugHalt.WaitOne();
+                        if (Interlocked.CompareExchange(ref context._shouldStep, 0, 1) == 1)
+                        {
+                            context.DebugPc = Step(context, context.DebugPc);
+
+                            context._stepBarrier.SignalAndWait();
+                            context._stepBarrier.SignalAndWait();
+                        }
+                        else
+                        {
+                            Interlocked.CompareExchange(ref context._debugState, (int)DebugState.Running, (int)DebugState.Stopped);
+                        }
+                    }
+                }
+                while (context.Running && context.DebugPc != 0);
+            }
+            else if (Optimizations.UseUnmanagedDispatchLoop)
             {
                 Stubs.DispatchLoop(context.NativeContextPtr, address);
             }
@@ -249,7 +275,7 @@ namespace ARMeilleure.Translation
                 Stubs,
                 address,
                 highCq,
-                _ptc.State != PtcState.Disabled,
+                _ptc.State != PtcState.Disabled && !Optimizations.EnableDebugging,
                 mode: Aarch32Mode.User);
 
             Logger.StartPass(PassName.Decoding);
@@ -382,9 +408,8 @@ namespace ARMeilleure.Translation
 
                 if (block.Exit)
                 {
-                    // Left option here as it may be useful if we need to return to managed rather than tail call in
-                    // future. (eg. for debug)
-                    bool useReturns = false;
+                    // Return to managed rather than tail call.
+                    bool useReturns = Optimizations.EnableDebugging;
 
                     InstEmitFlowHelper.EmitVirtualJump(context, Const(block.Address), isReturn: useReturns);
                 }