Use generic interface type on MOS 6052X for talking to the emulator core (#1189)

* Use generic interface type on MOS 6052X for talking to the emulator core
* Change CpuLink constructors to not use expression-bodies, to get the AppVeyor build to pass.
* Add comment explaining why IMOS6502XLink exists.

BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj

@@ -1301,6 +1301,7 @@
     <Compile Include="CPUs\LR35902\Registers.cs" />
     <Compile Include="CPUs\LR35902\Tables_Direct.cs" />
     <Compile Include="CPUs\LR35902\Tables_Indirect.cs" />
+    <Compile Include="CPUs\MOS 6502X\IMOS6502XLink.cs" />
     <Compile Include="CPUs\W65816\Disassembler.cs" />
     <Compile Include="CPUs\68000\Diassembler.cs" />
     <Compile Include="CPUs\68000\Instructions\BitArithemetic.cs" />
@@ -1441,6 +1442,7 @@
     <None Include="Consoles\Nintendo\NES\Docs\BoardTable.xlsx" />
     <None Include="Consoles\Nintendo\NES\Docs\MapperCompatibilityList.url" />
     <None Include="Consoles\Nintendo\NES\Docs\nesasm.pdf" />
+    <Compile Include="Consoles\Nintendo\NES\NES.CpuLink.cs" />
     <None Include="Resources\128.ROM.gz" />
     <None Include="Resources\48.ROM.gz" />
     <None Include="Resources\cgb_boot.bin.gz" />

BizHawk.Emulation.Cores/CPUs/MOS 6502X/Disassembler.cs

@@ -4,7 +4,7 @@ using System.Collections.Generic;
 
 namespace BizHawk.Emulation.Cores.Components.M6502
 {
-	public partial class MOS6502X : IDisassemblable
+	public partial class MOS6502X<TLink> : IDisassemblable
 	{
 		private static ushort peeker_word(ushort address, Func<ushort, byte> peeker)
 		{
@@ -15,7 +15,43 @@ namespace BizHawk.Emulation.Cores.Components.M6502
 
 		public string Disassemble(ushort pc, out int bytesToAdvance)
 		{
-			return Disassemble(pc, out bytesToAdvance, PeekMemory);
+			return MOS6502X.Disassemble(pc, out bytesToAdvance, _link.PeekMemory);
+		}
+
+		public string Cpu
+		{
+			get
+			{
+				return "6502";
+			}
+			set
+			{
+			}
+		}
+
+		public string PCRegisterName
+		{
+			get { return "PC"; }
+		}
+
+		public IEnumerable<string> AvailableCpus
+		{
+			get { yield return "6502"; }
+		}
+
+		public string Disassemble(MemoryDomain m, uint addr, out int length)
+		{
+			return MOS6502X.Disassemble((ushort)addr, out length, a => m.PeekByte((int)a));
+		}
+	}
+
+	public static class MOS6502X
+	{
+		private static ushort peeker_word(ushort address, Func<ushort, byte> peeker)
+		{
+			byte l = peeker(address);
+			byte h = peeker(++address);
+			return (ushort)((h << 8) | l);
 		}
 
 		/// <summary>
@@ -208,31 +244,5 @@ namespace BizHawk.Emulation.Cores.Components.M6502
 			bytesToAdvance = 1;
 			return "???";
 		}
-
-		public string Cpu
-		{
-			get
-			{
-				return "6502";
-			}
-			set
-			{
-			}
-		}
-
-		public string PCRegisterName
-		{
-			get { return "PC"; }
-		}
-
-		public IEnumerable<string> AvailableCpus
-		{
-			get { yield return "6502"; }
-		}
-
-		public string Disassemble(MemoryDomain m, uint addr, out int length)
-		{
-			return Disassemble((ushort)addr, out length, a => m.PeekByte((int)a));
-		}
 	}
 }

BizHawk.Emulation.Cores/CPUs/MOS 6502X/IMOS6502XLink.cs

@@ -0,0 +1,18 @@
+namespace BizHawk.Emulation.Cores.Components.M6502
+{
+	// Interface that has all the methods required by the MOS 6502X to talk to
+	// the emulator core.
+	// Should only be used as a generic type argument for the MOS 6502X, and
+	// implementations should be structs where possible. This combination allows
+	// the JITer to generate much faster code than calling a Func<> or Action<>.
+	public interface IMOS6502XLink
+	{
+		byte ReadMemory(ushort address);
+		byte DummyReadMemory(ushort address);
+		byte PeekMemory(ushort address);
+		void WriteMemory(ushort address, byte value);
+
+		// This only calls when the first byte of an instruction is fetched.
+		void OnExecFetch(ushort address);
+	}
+}

BizHawk.Emulation.Cores/CPUs/MOS 6502X/MOS6502X.cs

@@ -6,10 +6,13 @@ using BizHawk.Emulation.Common;
 
 namespace BizHawk.Emulation.Cores.Components.M6502
 {
-	public sealed partial class MOS6502X
+	public sealed partial class MOS6502X<TLink> where TLink : IMOS6502XLink
 	{
-		public MOS6502X()
+		private readonly TLink _link;
+
+		public MOS6502X(TLink link)
 		{
+			_link = link;
 			InitOpcodeHandlers();
 			Reset();
 		}
@@ -62,7 +65,7 @@ namespace BizHawk.Emulation.Cores.Components.M6502
 
 			for (int i = 0; i < length; i++)
 			{
-				rawbytes += string.Format(" {0:X2}", PeekMemory((ushort)(PC + i)));
+				rawbytes += string.Format(" {0:X2}", _link.PeekMemory((ushort)(PC + i)));
 			}
 
 			return new TraceInfo
@@ -206,39 +209,17 @@ namespace BizHawk.Emulation.Cores.Components.M6502
 
 		public long TotalExecutedCycles;
 
-		public Func<ushort, byte> ReadMemory;
-		public Func<ushort, byte> DummyReadMemory;
-		public Func<ushort, byte> PeekMemory;
-		public Action<ushort, byte> WriteMemory;
-
-		//this only calls when the first byte of an instruction is fetched.
-		public Action<ushort> OnExecFetch;
-
-		public void SetCallbacks
-		(
-			Func<ushort, byte> ReadMemory,
-			Func<ushort, byte> DummyReadMemory,
-			Func<ushort, byte> PeekMemory,
-			Action<ushort, byte> WriteMemory
-		)
-		{
-			this.ReadMemory = ReadMemory;
-			this.DummyReadMemory = DummyReadMemory;
-			this.PeekMemory = PeekMemory;
-			this.WriteMemory = WriteMemory;
-		}
-
 		public ushort ReadWord(ushort address)
 		{
-			byte l = ReadMemory(address);
+			byte l = _link.ReadMemory(address);
-			byte h = ReadMemory(++address);
+			byte h = _link.ReadMemory(++address);
 			return (ushort)((h << 8) | l);
 		}
 
 		public ushort PeekWord(ushort address)
 		{
-			byte l = PeekMemory(address);
+			byte l = _link.PeekMemory(address);
-			byte h = PeekMemory(++address);
+			byte h = _link.PeekMemory(++address);
 			return (ushort)((h << 8) | l);
 		}
 
@@ -246,14 +227,14 @@ namespace BizHawk.Emulation.Cores.Components.M6502
 		{
 			byte l = (byte)(value & 0xFF);
 			byte h = (byte)(value >> 8);
-			WriteMemory(address, l);
+			_link.WriteMemory(address, l);
-			WriteMemory(++address, h);
+			_link.WriteMemory(++address, h);
 		}
 
 		private ushort ReadWordPageWrap(ushort address)
 		{
 			ushort highAddress = (ushort)((address & 0xFF00) + ((address + 1) & 0xFF));
-			return (ushort)(ReadMemory(address) | (ReadMemory(highAddress) << 8));
+			return (ushort)(_link.ReadMemory(address) | (_link.ReadMemory(highAddress) << 8));
 		}
 
 		// SO pin

BizHawk.Emulation.Cores/Computers/Commodore64/MOS/Chip6510.cs

@@ -10,11 +10,31 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
 	public sealed partial class Chip6510
 	{
 		// ------------------------------------
-		private readonly MOS6502X _cpu;
+		private readonly MOS6502X<CpuLink> _cpu;
 		private bool _pinNmiLast;
 		private LatchedPort _port;
 		private bool _thisNmi;
 
+		private struct CpuLink : IMOS6502XLink
+		{
+			private readonly Chip6510 _chip;
+
+			public CpuLink(Chip6510 chip)
+			{
+				_chip = chip;
+			}
+
+			public byte DummyReadMemory(ushort address) => unchecked((byte)_chip.Read(address));
+
+			public void OnExecFetch(ushort address) { }
+
+			public byte PeekMemory(ushort address) => unchecked((byte)_chip.Peek(address));
+
+			public byte ReadMemory(ushort address) => unchecked((byte)_chip.Read(address));
+
+			public void WriteMemory(ushort address, byte value) => _chip.Write(address, value);
+		}
+
 		public Func<int, int> PeekMemory;
 		public Action<int, int> PokeMemory;
 		public Func<bool> ReadAec;
@@ -33,13 +53,7 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
 		public Chip6510()
 		{
 			// configure cpu r/w
-			_cpu = new MOS6502X
+			_cpu = new MOS6502X<CpuLink>(new CpuLink(this));
-			{
-				DummyReadMemory = CpuRead,
-				ReadMemory = CpuRead,
-				WriteMemory = CpuWrite,
-				PeekMemory = CpuPeek
-			};
 
 			// perform hard reset
 			HardReset();

BizHawk.Emulation.Cores/Computers/Commodore64/Serial/Drive1541.cs

@@ -19,7 +19,7 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.Serial
 		private bool _motorEnabled;
 		private bool _ledEnabled;
 		private int _motorStep;
-		private readonly MOS6502X _cpu;
+		private readonly MOS6502X<CpuLink> _cpu;
 		private int[] _ram;
 		public readonly Via Via0;
 		public readonly Via Via1;
@@ -31,15 +31,31 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.Serial
 		public Action DebuggerStep;
 		public readonly Chip23128 DriveRom;
 
+		private struct CpuLink : IMOS6502XLink
+		{
+			private readonly Drive1541 _drive;
+
+			public CpuLink(Drive1541 drive)
+			{
+				_drive = drive;
+			}
+
+			public byte DummyReadMemory(ushort address) => unchecked((byte)_drive.Read(address));
+
+			public void OnExecFetch(ushort address) { }
+
+			public byte PeekMemory(ushort address) => unchecked((byte)_drive.Peek(address));
+
+			public byte ReadMemory(ushort address) => unchecked((byte)_drive.Read(address));
+
+			public void WriteMemory(ushort address, byte value) => _drive.Write(address, value);
+		}
+
 		public Drive1541(int clockNum, int clockDen)
 		{
 			DriveRom = new Chip23128();
-			_cpu = new MOS6502X
+			_cpu = new MOS6502X<CpuLink>(new CpuLink(this))
 			{
-				ReadMemory = CpuRead,
-				WriteMemory = CpuWrite,
-				DummyReadMemory = CpuRead,
-				PeekMemory = CpuPeek,
 				NMI = false
 			};
 

BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.Core.cs

@@ -28,11 +28,31 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 		private bool _leftDifficultySwitchHeld;
 		private bool _rightDifficultySwitchHeld;
 
-		internal MOS6502X Cpu { get; private set; }
+		internal MOS6502X<CpuLink> Cpu { get; private set; }
 		internal byte[] Ram => _ram;
 		internal byte[] Rom { get; }
 		internal int DistinctAccessCount { get; private set; }
 
+		internal struct CpuLink : IMOS6502XLink
+		{
+			private readonly Atari2600 _atari2600;
+
+			public CpuLink(Atari2600 atari2600)
+			{
+				_atari2600 = atari2600;
+			}
+
+			public byte DummyReadMemory(ushort address) => _atari2600.ReadMemory(address);
+
+			public void OnExecFetch(ushort address) => _atari2600.ExecFetch(address);
+
+			public byte PeekMemory(ushort address) => _atari2600.ReadMemory(address);
+
+			public byte ReadMemory(ushort address) => _atari2600.ReadMemory(address);
+
+			public void WriteMemory(ushort address, byte value) => _atari2600.WriteMemory(address, value);
+		}
+
 		// keeps track of tia cycles, 3 cycles per CPU cycle
 		private int cyc_counter;
 
@@ -292,14 +312,7 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 			_mapper.Core = this;
 
 			_lagcount = 0;
-			Cpu = new MOS6502X
+			Cpu = new MOS6502X<CpuLink>(new CpuLink(this));
-			{
-				ReadMemory = ReadMemory,
-				WriteMemory = WriteMemory,
-				PeekMemory = PeekMemory,
-				DummyReadMemory = ReadMemory,
-				OnExecFetch = ExecFetch
-			};
 
 			if (_game["PAL"])
 			{
@@ -334,14 +347,7 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 			_ram = new byte[128];
 			_mapper.HardReset();
 
-			Cpu = new MOS6502X
+			Cpu = new MOS6502X<CpuLink>(new CpuLink(this));
-			{
-				ReadMemory = ReadMemory,
-				WriteMemory = WriteMemory,
-				PeekMemory = PeekMemory,
-				DummyReadMemory = ReadMemory,
-				OnExecFetch = ExecFetch
-			};
 
 			_tia.Reset();
 			_m6532 = new M6532(this);

BizHawk.Emulation.Cores/Consoles/Atari/A7800Hawk/A7800Hawk.cs

@@ -44,13 +44,33 @@ namespace BizHawk.Emulation.Cores.Atari.A7800Hawk
 
 		private readonly ITraceable _tracer;
 
-		public MOS6502X cpu;
+		public MOS6502X<CpuLink> cpu;
 		public Maria maria;
 		public bool _isPAL;
 		public M6532 m6532;
 		public TIA tia;
 		public Pokey pokey;
 
+		public struct CpuLink : IMOS6502XLink
+		{
+			private readonly A7800Hawk _a7800;
+
+			public CpuLink(A7800Hawk a7800)
+			{
+				_a7800 = a7800;
+			}
+
+			public byte DummyReadMemory(ushort address) => _a7800.ReadMemory(address);
+
+			public void OnExecFetch(ushort address) => _a7800.ExecFetch(address);
+
+			public byte PeekMemory(ushort address) => _a7800.ReadMemory(address);
+
+			public byte ReadMemory(ushort address) => _a7800.ReadMemory(address);
+
+			public void WriteMemory(ushort address, byte value) => _a7800.WriteMemory(address, value);
+		}
+
 		public A7800Hawk(CoreComm comm, GameInfo game, byte[] rom, string gameDbFn, object settings, object syncSettings)
 		{
 			var ser = new BasicServiceProvider(this);
@@ -60,14 +80,7 @@ namespace BizHawk.Emulation.Cores.Atari.A7800Hawk
 			m6532 = new M6532();
 			pokey = new Pokey();
 
-			cpu = new MOS6502X
+			cpu = new MOS6502X<CpuLink>(new CpuLink(this));
-			{
-				ReadMemory = ReadMemory,
-				WriteMemory = WriteMemory,
-				PeekMemory = ReadMemory,
-				DummyReadMemory = ReadMemory,
-				OnExecFetch = ExecFetch
-			};
 
 			maria = new Maria
 			{
@@ -255,7 +268,6 @@ namespace BizHawk.Emulation.Cores.Atari.A7800Hawk
 
 			tia.Reset();
 			cpu.Reset();
-			cpu.SetCallbacks(ReadMemory, ReadMemory, ReadMemory, WriteMemory);
 
 			maria.Reset();
 			m6532.Reset();

BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.Core.cs

@@ -12,7 +12,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 	public partial class NES : IEmulator, ICycleTiming
 	{
 		//hardware/state
-		public MOS6502X cpu;
+		public MOS6502X<CpuLink> cpu;
 		public PPU ppu;
 		public APU apu;
 		public byte[] ram;
@@ -159,11 +159,11 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 
 		public void HardReset()
 		{
-			cpu = new MOS6502X();
+			cpu = new MOS6502X<CpuLink>(new CpuLink(this))
-			cpu.SetCallbacks(ReadMemory, ReadMemory, PeekMemory, WriteMemory);
+			{
+				BCD_Enabled = false
+			};
 
-			cpu.BCD_Enabled = false;
-			cpu.OnExecFetch = ExecFetch;
 			ppu = new PPU(this);
 			ram = new byte[0x800];
 			CIRAM = new byte[0x800];

BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.CpuLink.cs

@@ -0,0 +1,27 @@
+using BizHawk.Emulation.Cores.Components.M6502;
+
+namespace BizHawk.Emulation.Cores.Nintendo.NES
+{
+    public partial class NES
+    {
+		public struct CpuLink : IMOS6502XLink
+		{
+			private readonly NES _nes;
+
+			public CpuLink(NES nes)
+			{
+				_nes = nes;
+			}
+
+			public byte DummyReadMemory(ushort address) => _nes.ReadMemory(address);
+
+			public void OnExecFetch(ushort address) => _nes.ExecFetch(address);
+
+			public byte PeekMemory(ushort address) => _nes.CDL == null ? _nes.PeekMemory(address) : _nes.FetchMemory_CDL(address);
+
+			public byte ReadMemory(ushort address) => _nes.CDL == null ? _nes.ReadMemory(address) : _nes.ReadMemory_CDL(address);
+
+			public void WriteMemory(ushort address, byte value) => _nes.WriteMemory(address, value);
+		}
+	}
+}

BizHawk.Emulation.Cores/Consoles/Nintendo/NES/NES.ICodeDataLogger.cs

@@ -9,18 +9,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 		public void SetCDL(ICodeDataLog cdl)
 		{
 			CDL = cdl;
-			if (cdl == null)
-			{
-				cpu.ReadMemory = ReadMemory;
-				cpu.WriteMemory = WriteMemory;
-				cpu.PeekMemory = PeekMemory;
-			}
-			else
-			{
-				cpu.ReadMemory = ReadMemory_CDL;
-				cpu.WriteMemory = WriteMemory;
-				cpu.PeekMemory = FetchMemory_CDL;
-			}
 		}
 
 		public void NewCDL(ICodeDataLog cdl)