Refactor CPU interface to allow the implementation of other CPU emulators (#3362)

* Refactor CPU interface

* Use IExecutionContext interface on SVC handler, change how CPU interrupts invokes the handlers

* Make CpuEngine take a ITickSource rather than returning one

The previous implementation had the scenario where the CPU engine had to implement the tick source in mind, like for example, when we have a hypervisor and the game can read CNTPCT on the host directly. However given that we need to do conversion due to different frequencies anyway, it's not worth it. It's better to just let the user pass the tick source and redirect any reads to CNTPCT to the user tick source

* XML docs for the public interfaces

* PPTC invalidation due to NativeInterface function name changes

* Fix build of the CPU tests

* PR feedback

Ryujinx.HLE/HOS/Kernel/Process/HleProcessDebugger.cs

@@ -115,7 +115,7 @@ namespace Ryujinx.HLE.HOS.Kernel.Process
 
             string GetReg(int x)
             {
-                var v = x == 32 ? (ulong)thread.LastPc : context.GetX(x);
+                var v = x == 32 ? context.Pc : context.GetX(x);
                 if (!AnalyzePointer(out PointerInfo info, v, thread))
                 {
                     return $"0x{v:x16}";

Ryujinx.HLE/HOS/Kernel/Process/IProcessContext.cs

@@ -1,4 +1,4 @@
-using ARMeilleure.State;
+using Ryujinx.Cpu;
 using Ryujinx.Memory;
 using System;
 
@@ -8,7 +8,8 @@ namespace Ryujinx.HLE.HOS.Kernel.Process
     {
         IVirtualMemoryManager AddressSpace { get; }
 
-        void Execute(ExecutionContext context, ulong codeAddress);
+        IExecutionContext CreateExecutionContext(ExceptionCallbacks exceptionCallbacks);
+        void Execute(IExecutionContext context, ulong codeAddress);
         void InvalidateCacheRegion(ulong address, ulong size);
     }
 }

Ryujinx.HLE/HOS/Kernel/Process/KProcess.cs

@@ -1,4 +1,3 @@
-using ARMeilleure.State;
 using Ryujinx.Common;
 using Ryujinx.Common.Logging;
 using Ryujinx.Cpu;
@@ -744,14 +743,16 @@ namespace Ryujinx.HLE.HOS.Kernel.Process
             }
         }
 
-        public void SubscribeThreadEventHandlers(ARMeilleure.State.ExecutionContext context)
+        public IExecutionContext CreateExecutionContext()
         {
-            context.Interrupt += InterruptHandler;
-            context.SupervisorCall += KernelContext.SyscallHandler.SvcCall;
-            context.Undefined += UndefinedInstructionHandler;
+            return Context?.CreateExecutionContext(new ExceptionCallbacks(
+                InterruptHandler,
+                null,
+                KernelContext.SyscallHandler.SvcCall,
+                UndefinedInstructionHandler));
         }
 
-        private void InterruptHandler(object sender, EventArgs e)
+        private void InterruptHandler(IExecutionContext context)
         {
             KThread currentThread = KernelStatic.GetCurrentThread();
 
@@ -1093,12 +1094,12 @@ namespace Ryujinx.HLE.HOS.Kernel.Process
             return false;
         }
 
-        private void UndefinedInstructionHandler(object sender, InstUndefinedEventArgs e)
+        private void UndefinedInstructionHandler(IExecutionContext context, ulong address, int opCode)
         {
             KernelStatic.GetCurrentThread().PrintGuestStackTrace();
             KernelStatic.GetCurrentThread()?.PrintGuestRegisterPrintout();
 
-            throw new UndefinedInstructionException(e.Address, e.OpCode);
+            throw new UndefinedInstructionException(address, opCode);
         }
 
         protected override void Destroy() => Context.Dispose();

Ryujinx.HLE/HOS/Kernel/Process/ProcessContext.cs

@@ -1,4 +1,4 @@
-using ARMeilleure.State;
+using Ryujinx.Cpu;
 using Ryujinx.Memory;
 using System;
 
@@ -13,7 +13,12 @@ namespace Ryujinx.HLE.HOS.Kernel.Process
             AddressSpace = asManager;
         }
 
-        public void Execute(ExecutionContext context, ulong codeAddress)
+        public IExecutionContext CreateExecutionContext(ExceptionCallbacks exceptionCallbacks)
+        {
+            return new ProcessExecutionContext();
+        }
+
+        public void Execute(IExecutionContext context, ulong codeAddress)
         {
             throw new NotSupportedException();
         }

Ryujinx.HLE/HOS/Kernel/Process/ProcessExecutionContext.cs

@@ -0,0 +1,44 @@
+using ARMeilleure.State;
+using Ryujinx.Cpu;
+
+namespace Ryujinx.HLE.HOS.Kernel.Process
+{
+    class ProcessExecutionContext : IExecutionContext
+    {
+        public ulong Pc => 0UL;
+
+        public ulong CntfrqEl0 { get => 0; set { } }
+        public ulong CntpctEl0 => 0UL;
+
+        public long TpidrEl0 { get => 0; set { } }
+        public long TpidrroEl0 { get => 0; set { } }
+
+        public uint Pstate { get => 0; set { } }
+
+        public uint Fpcr { get => 0; set { } }
+        public uint Fpsr { get => 0; set { } }
+
+        public bool IsAarch32 { get => false; set { } }
+
+        public bool Running { get; private set; } = true;
+
+        public ulong GetX(int index) => 0UL;
+        public void SetX(int index, ulong value) { }
+
+        public V128 GetV(int index) => default;
+        public void SetV(int index, V128 value) { }
+
+        public void RequestInterrupt()
+        {
+        }
+
+        public void StopRunning()
+        {
+            Running = false;
+        }
+
+        public void Dispose()
+        {
+        }
+    }
+}