Add CompoundAssignment mode to BinaryNumericInstruction

ICSharpCode.Decompiler/IL/Instructions.cs

@@ -394,7 +394,7 @@ namespace ICSharpCode.Decompiler.IL
 	/// <summary>Adds two numbers.</summary>
 	public sealed partial class Add : BinaryNumericInstruction
 	{
-		public Add(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign) : base(OpCode.Add, left, right, checkForOverflow, sign)
+		public Add(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign, CompoundAssignmentType compoundAssignmentType = CompoundAssignmentType.None) : base(OpCode.Add, left, right, checkForOverflow, sign, compoundAssignmentType)
 		{
 		}
 
@@ -407,7 +407,7 @@ namespace ICSharpCode.Decompiler.IL
 	/// <summary>Subtracts two numbers</summary>
 	public sealed partial class Sub : BinaryNumericInstruction
 	{
-		public Sub(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign) : base(OpCode.Sub, left, right, checkForOverflow, sign)
+		public Sub(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign, CompoundAssignmentType compoundAssignmentType = CompoundAssignmentType.None) : base(OpCode.Sub, left, right, checkForOverflow, sign, compoundAssignmentType)
 		{
 		}
 
@@ -420,7 +420,7 @@ namespace ICSharpCode.Decompiler.IL
 	/// <summary>Multiplies two numbers</summary>
 	public sealed partial class Mul : BinaryNumericInstruction
 	{
-		public Mul(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign) : base(OpCode.Mul, left, right, checkForOverflow, sign)
+		public Mul(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign, CompoundAssignmentType compoundAssignmentType = CompoundAssignmentType.None) : base(OpCode.Mul, left, right, checkForOverflow, sign, compoundAssignmentType)
 		{
 		}
 
@@ -433,7 +433,7 @@ namespace ICSharpCode.Decompiler.IL
 	/// <summary>Divides two numbers</summary>
 	public sealed partial class Div : BinaryNumericInstruction
 	{
-		public Div(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign) : base(OpCode.Div, left, right, checkForOverflow, sign)
+		public Div(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign, CompoundAssignmentType compoundAssignmentType = CompoundAssignmentType.None) : base(OpCode.Div, left, right, checkForOverflow, sign, compoundAssignmentType)
 		{
 		}
 
@@ -450,7 +450,7 @@ namespace ICSharpCode.Decompiler.IL
 	/// <summary>Division remainder</summary>
 	public sealed partial class Rem : BinaryNumericInstruction
 	{
-		public Rem(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign) : base(OpCode.Rem, left, right, checkForOverflow, sign)
+		public Rem(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign, CompoundAssignmentType compoundAssignmentType = CompoundAssignmentType.None) : base(OpCode.Rem, left, right, checkForOverflow, sign, compoundAssignmentType)
 		{
 		}
 
@@ -467,7 +467,7 @@ namespace ICSharpCode.Decompiler.IL
 	/// <summary>Bitwise AND</summary>
 	public sealed partial class BitAnd : BinaryNumericInstruction
 	{
-		public BitAnd(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign) : base(OpCode.BitAnd, left, right, checkForOverflow, sign)
+		public BitAnd(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign, CompoundAssignmentType compoundAssignmentType = CompoundAssignmentType.None) : base(OpCode.BitAnd, left, right, checkForOverflow, sign, compoundAssignmentType)
 		{
 		}
 
@@ -480,7 +480,7 @@ namespace ICSharpCode.Decompiler.IL
 	/// <summary>Bitwise OR</summary>
 	public sealed partial class BitOr : BinaryNumericInstruction
 	{
-		public BitOr(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign) : base(OpCode.BitOr, left, right, checkForOverflow, sign)
+		public BitOr(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign, CompoundAssignmentType compoundAssignmentType = CompoundAssignmentType.None) : base(OpCode.BitOr, left, right, checkForOverflow, sign, compoundAssignmentType)
 		{
 		}
 
@@ -493,7 +493,7 @@ namespace ICSharpCode.Decompiler.IL
 	/// <summary>Bitwise XOR</summary>
 	public sealed partial class BitXor : BinaryNumericInstruction
 	{
-		public BitXor(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign) : base(OpCode.BitXor, left, right, checkForOverflow, sign)
+		public BitXor(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign, CompoundAssignmentType compoundAssignmentType = CompoundAssignmentType.None) : base(OpCode.BitXor, left, right, checkForOverflow, sign, compoundAssignmentType)
 		{
 		}
 
@@ -1127,7 +1127,7 @@ namespace ICSharpCode.Decompiler.IL
 	/// <summary>Shift left</summary>
 	public sealed partial class Shl : BinaryNumericInstruction
 	{
-		public Shl(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign) : base(OpCode.Shl, left, right, checkForOverflow, sign)
+		public Shl(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign, CompoundAssignmentType compoundAssignmentType = CompoundAssignmentType.None) : base(OpCode.Shl, left, right, checkForOverflow, sign, compoundAssignmentType)
 		{
 		}
 
@@ -1140,7 +1140,7 @@ namespace ICSharpCode.Decompiler.IL
 	/// <summary>Shift right</summary>
 	public sealed partial class Shr : BinaryNumericInstruction
 	{
-		public Shr(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign) : base(OpCode.Shr, left, right, checkForOverflow, sign)
+		public Shr(ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign, CompoundAssignmentType compoundAssignmentType = CompoundAssignmentType.None) : base(OpCode.Shr, left, right, checkForOverflow, sign, compoundAssignmentType)
 		{
 		}
 
@@ -2277,29 +2277,29 @@ namespace ICSharpCode.Decompiler.IL
 	
 	partial class BinaryNumericInstruction
 	{
-		public static BinaryNumericInstruction Create(OpCode opCode, ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign)
+		public static BinaryNumericInstruction Create(OpCode opCode, ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign, CompoundAssignmentType compoundAssignmentType = CompoundAssignmentType.None)
 		{
 			switch (opCode) {
 				case OpCode.Add:
-					return new Add(left, right, checkForOverflow, sign);
+					return new Add(left, right, checkForOverflow, sign, compoundAssignmentType);
 				case OpCode.Sub:
-					return new Sub(left, right, checkForOverflow, sign);
+					return new Sub(left, right, checkForOverflow, sign, compoundAssignmentType);
 				case OpCode.Mul:
-					return new Mul(left, right, checkForOverflow, sign);
+					return new Mul(left, right, checkForOverflow, sign, compoundAssignmentType);
 				case OpCode.Div:
-					return new Div(left, right, checkForOverflow, sign);
+					return new Div(left, right, checkForOverflow, sign, compoundAssignmentType);
 				case OpCode.Rem:
-					return new Rem(left, right, checkForOverflow, sign);
+					return new Rem(left, right, checkForOverflow, sign, compoundAssignmentType);
 				case OpCode.BitAnd:
-					return new BitAnd(left, right, checkForOverflow, sign);
+					return new BitAnd(left, right, checkForOverflow, sign, compoundAssignmentType);
 				case OpCode.BitOr:
-					return new BitOr(left, right, checkForOverflow, sign);
+					return new BitOr(left, right, checkForOverflow, sign, compoundAssignmentType);
 				case OpCode.BitXor:
-					return new BitXor(left, right, checkForOverflow, sign);
+					return new BitXor(left, right, checkForOverflow, sign, compoundAssignmentType);
 				case OpCode.Shl:
-					return new Shl(left, right, checkForOverflow, sign);
+					return new Shl(left, right, checkForOverflow, sign, compoundAssignmentType);
 				case OpCode.Shr:
-					return new Shr(left, right, checkForOverflow, sign);
+					return new Shr(left, right, checkForOverflow, sign, compoundAssignmentType);
 				default:
 					throw new ArgumentException("opCode is not a binary numeric instruction");
 			}

ICSharpCode.Decompiler/IL/Instructions.tt

@@ -185,8 +185,6 @@
 		new OpCode("ldelema", "Load address of array element.",
 			CustomClassName("LdElema"), CustomArguments("array", "index"), HasTypeOperand,
 			MayThrow, ResultType("Ref"), SupportsReadonlyPrefix),
-		
-		
 	};
 #>
 using System;
@@ -254,12 +252,12 @@ namespace ICSharpCode.Decompiler.IL
 	
 	partial class BinaryNumericInstruction
 	{
-		public static BinaryNumericInstruction Create(OpCode opCode, ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign)
+		public static BinaryNumericInstruction Create(OpCode opCode, ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign, CompoundAssignmentType compoundAssignmentType = CompoundAssignmentType.None)
 		{
 			switch (opCode) {
 <#	foreach (OpCode opCode in opCodes.Where(c => c.BaseClass == "BinaryNumericInstruction")) { #>
 				case OpCode.<#=opCode.Name#>:
-					return new <#=opCode.Name#>(left, right, checkForOverflow, sign);
+					return new <#=opCode.Name#>(left, right, checkForOverflow, sign, compoundAssignmentType);
 <#	} #>
 				default:
 					throw new ArgumentException("opCode is not a binary numeric instruction");
@@ -485,10 +483,10 @@ namespace ICSharpCode.Decompiler.IL
 		opCode.BaseClass = "BinaryNumericInstruction";
 		opCode.ConstructorParameters.Add("bool checkForOverflow");
 		opCode.BaseConstructorArguments.Add("checkForOverflow");
-		opCode.WriteOpCodeSuffix.Add("if (checkForOverflow) output.Write(\".ovf\");");
 		opCode.ConstructorParameters.Add("Sign sign");
 		opCode.BaseConstructorArguments.Add("sign");
-		opCode.WriteOpCodeSuffix.Add("if (sign == Sign.Unsigned) output.Write(\".un\");");
+		opCode.ConstructorParameters.Add("CompoundAssignmentType compoundAssignmentType = CompoundAssignmentType.None");
+		opCode.BaseConstructorArguments.Add("compoundAssignmentType");
 	};
 	
 	// BinaryNumeric trait: the instruction is derived from BinaryComparisonInstruction. Implies Binary and I4Result.

ICSharpCode.Decompiler/IL/Instructions/BinaryNumericInstruction.cs

@@ -24,8 +24,20 @@ using System.Text;
 using System.Threading.Tasks;
 namespace ICSharpCode.Decompiler.IL
 {
+	public enum CompoundAssignmentType : byte
+	{
+		None,
+		EvaluatesToOldValue,
+		EvaluatesToNewValue
+	}
+	
 	public abstract partial class BinaryNumericInstruction : BinaryInstruction
 	{
+		/// <summary>
+		/// Gets whether this instruction is a compound assignment.
+		/// </summary>
+		public readonly CompoundAssignmentType CompoundAssignmentType;
+		
 		/// <summary>
 		/// Gets whether the instruction checks for overflow.
 		/// </summary>
@@ -40,12 +52,30 @@ namespace ICSharpCode.Decompiler.IL
 
 		readonly StackType resultType;
 
-		protected BinaryNumericInstruction(OpCode opCode, ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign)
+		protected BinaryNumericInstruction(OpCode opCode, ILInstruction left, ILInstruction right, bool checkForOverflow, Sign sign, CompoundAssignmentType compoundAssignmentType)
 			: base(opCode, left, right)
 		{
 			this.CheckForOverflow = checkForOverflow;
 			this.Sign = sign;
+			this.CompoundAssignmentType = compoundAssignmentType;
 			this.resultType = ComputeResultType(opCode, left.ResultType, right.ResultType);
+			Debug.Assert(CompoundAssignmentType == CompoundAssignmentType.None || IsValidCompoundAssignmentTarget(Left));
+		}
+		
+		internal static bool IsValidCompoundAssignmentTarget(ILInstruction inst)
+		{
+			switch (inst.OpCode) {
+				case OpCode.LdLoc:
+				case OpCode.LdFld:
+				case OpCode.LdsFld:
+				case OpCode.LdObj:
+					return true;
+				case OpCode.Call:
+				case OpCode.CallVirt:
+					return true; // TODO: check if corresponding setter exists
+				default:
+					return false;
+			}
 		}
 		
 		internal static StackType ComputeResultType(OpCode opCode, StackType left, StackType right)
@@ -78,16 +108,54 @@ namespace ICSharpCode.Decompiler.IL
 			}
 		}
 
+		internal override void CheckInvariant()
+		{
+			base.CheckInvariant();
+			Debug.Assert(CompoundAssignmentType == CompoundAssignmentType.None || IsValidCompoundAssignmentTarget(Left));
+		}
+
+		protected override void Connected()
+		{
+			base.Connected();
+			// Count the local variable store due to the compound assignment:
+			ILVariable v;
+			if (CompoundAssignmentType != CompoundAssignmentType.None && Left.MatchLdLoc(out v)) {
+				v.StoreCount++;
+			}
+		}
+		
+		protected override void Disconnected()
+		{
+			base.Disconnected();
+			// Count the local variable store due to the compound assignment:
+			ILVariable v;
+			if (CompoundAssignmentType != CompoundAssignmentType.None && Left.MatchLdLoc(out v)) {
+				v.StoreCount--;
+			}
+		}
+		
 		protected override InstructionFlags ComputeFlags()
 		{
 			var flags = base.ComputeFlags();
 			if (CheckForOverflow)
 				flags |= InstructionFlags.MayThrow;
+			// Set MayWriteLocals if this is a compound assignment to a local variable
+			if (CompoundAssignmentType != CompoundAssignmentType.None && Left.OpCode == OpCode.LdLoc)
+				flags |= InstructionFlags.MayWriteLocals;
 			return flags;
 		}
 
 		public override void WriteTo(ITextOutput output)
 		{
+			switch (CompoundAssignmentType) {
+				case CompoundAssignmentType.EvaluatesToNewValue:
+					output.Write("compound.assign");
+					break;
+				case CompoundAssignmentType.EvaluatesToOldValue:
+					output.Write("compound.assign.oldvalue");
+					break;
+			}
+			
 			output.Write(OpCode);
 			if (CheckForOverflow)
 				output.Write(".ovf");

ICSharpCode.Decompiler/IL/NRTypeExtensions.cs

@@ -148,7 +148,7 @@ namespace ICSharpCode.Decompiler.IL
 		}
 	}
 	
-	public enum Sign
+	public enum Sign : byte
 	{
 		None,
 		Signed,

ICSharpCode.Decompiler/IL/StackType.cs

@@ -27,7 +27,7 @@ namespace ICSharpCode.Decompiler.IL
 	/// <summary>
 	/// A type for the purpose of stack analysis.
 	/// </summary>
-	public enum StackType
+	public enum StackType : byte
 	{
 		Unknown,
 		/// <summary>32-bit integer</summary>