Fix #1853: Detect pinning of multi-dimensional array

ICSharpCode.Decompiler.Tests/TestCases/Pretty/UnsafeCode.cs

@@ -364,15 +364,22 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
 			return ptr->ToString();
 		}
 
+		public unsafe void FixedMultiDimArray(int[,] arr)
+		{
+			fixed (int* ptr = arr) {
+				UsePointer(ptr);
+			}
+		}
+
 #if CS73
-		public unsafe void PinSpan(Span<int> span)
+		public unsafe void FixedSpan(Span<int> span)
 		{
 			fixed (int* ptr = span) {
 				UsePointer(ptr);
 			}
 		}
 
-		//public unsafe void CustomPinReferenceType(CustomPinnable mem)
+		//public unsafe void FixedCustomReferenceType(CustomPinnable mem)
 		//{
 		//	fixed (int* ptr = mem) {
 		//		UsePointer(ptr);

ICSharpCode.Decompiler/IL/ControlFlow/DetectPinnedRegions.cs

@@ -209,8 +209,19 @@ namespace ICSharpCode.Decompiler.IL.ControlFlow
 				return false;
 			if (!block.Instructions[0].MatchIfInstruction(out ILInstruction condition, out ILInstruction trueInst))
 				return false;
-			if (!condition.UnwrapConv(ConversionKind.Truncate).MatchLdLen(StackType.I, out ILInstruction array))
+			condition = condition.UnwrapConv(ConversionKind.Truncate);
+			if (condition.MatchLdLen(StackType.I, out ILInstruction array)) {
+				// OK
+			} else if (condition is CallInstruction call && call.Method.Name == "get_Length") {
+				// Used instead of ldlen for multi-dimensional arrays
+				if (!call.Method.DeclaringType.IsKnownType(KnownTypeCode.Array))
+					return false;
+				if (call.Arguments.Count != 1)
+					return false;
+				array = call.Arguments[0];
+			} else {
 				return false;
+			}
 			if (!array.MatchLdLoc(v))
 				return false;
 			if (!trueInst.MatchBranch(out Block notNullAndNotEmptyBlock))

ICSharpCode.Decompiler/IL/Instructions.cs

@@ -3021,8 +3021,10 @@ namespace ICSharpCode.Decompiler.IL
 		{
 			WriteILRange(output, options);
 			output.Write(OpCode);
-			output.Write(' ');
-			method.WriteTo(output);
+			if (method != null) {
+				output.Write(' ');
+				method.WriteTo(output);
+			}
 		}
 		public override void AcceptVisitor(ILVisitor visitor)
 		{
@@ -3039,7 +3041,7 @@ namespace ICSharpCode.Decompiler.IL
 		protected internal override bool PerformMatch(ILInstruction other, ref Patterns.Match match)
 		{
 			var o = other as LdFtn;
-			return o != null && method.Equals(o.method);
+			return o != null && object.Equals(method, o.method);
 		}
 	}
 }
@@ -3069,8 +3071,10 @@ namespace ICSharpCode.Decompiler.IL
 		{
 			WriteILRange(output, options);
 			output.Write(OpCode);
-			output.Write(' ');
-			method.WriteTo(output);
+			if (method != null) {
+				output.Write(' ');
+				method.WriteTo(output);
+			}
 			output.Write('(');
 			Argument.WriteTo(output, options);
 			output.Write(')');
@@ -3090,7 +3094,7 @@ namespace ICSharpCode.Decompiler.IL
 		protected internal override bool PerformMatch(ILInstruction other, ref Patterns.Match match)
 		{
 			var o = other as LdVirtFtn;
-			return o != null && this.Argument.PerformMatch(o.Argument, ref match) && method.Equals(o.method);
+			return o != null && this.Argument.PerformMatch(o.Argument, ref match) && object.Equals(method, o.method);
 		}
 	}
 }
@@ -3129,8 +3133,10 @@ namespace ICSharpCode.Decompiler.IL
 			output.Write(OpCode);
 			output.Write(' ');
 			type.WriteTo(output);
-			output.Write(' ');
-			method.WriteTo(output);
+			if (method != null) {
+				output.Write(' ');
+				method.WriteTo(output);
+			}
 			output.Write('(');
 			Argument.WriteTo(output, options);
 			output.Write(')');
@@ -3150,7 +3156,7 @@ namespace ICSharpCode.Decompiler.IL
 		protected internal override bool PerformMatch(ILInstruction other, ref Patterns.Match match)
 		{
 			var o = other as LdVirtDelegate;
-			return o != null && this.Argument.PerformMatch(o.Argument, ref match) && type.Equals(o.type) && method.Equals(o.method);
+			return o != null && this.Argument.PerformMatch(o.Argument, ref match) && type.Equals(o.type) && object.Equals(method, o.method);
 		}
 	}
 }
@@ -4835,8 +4841,10 @@ namespace ICSharpCode.Decompiler.IL
 		{
 			WriteILRange(output, options);
 			output.Write(OpCode);
-			output.Write(' ');
-			method.WriteTo(output);
+			if (method != null) {
+				output.Write(' ');
+				method.WriteTo(output);
+			}
 			output.Write('(');
 			this.argument.WriteTo(output, options);
 			output.Write(')');
@@ -4856,7 +4864,7 @@ namespace ICSharpCode.Decompiler.IL
 		protected internal override bool PerformMatch(ILInstruction other, ref Patterns.Match match)
 		{
 			var o = other as GetPinnableReference;
-			return o != null && this.argument.PerformMatch(o.argument, ref match) && method.Equals(o.method);
+			return o != null && this.argument.PerformMatch(o.argument, ref match) && object.Equals(method, o.method);
 		}
 		internal override void CheckInvariant(ILPhase phase)
 		{
@@ -5074,8 +5082,10 @@ namespace ICSharpCode.Decompiler.IL
 		{
 			WriteILRange(output, options);
 			output.Write(OpCode);
-			output.Write(' ');
-			method.WriteTo(output);
+			if (method != null) {
+				output.Write(' ');
+				method.WriteTo(output);
+			}
 			output.Write('(');
 			this.left.WriteTo(output, options);
 			output.Write(", ");
@@ -5097,7 +5107,7 @@ namespace ICSharpCode.Decompiler.IL
 		protected internal override bool PerformMatch(ILInstruction other, ref Patterns.Match match)
 		{
 			var o = other as UserDefinedLogicOperator;
-			return o != null && method.Equals(o.method) && this.left.PerformMatch(o.left, ref match) && this.right.PerformMatch(o.right, ref match);
+			return o != null && object.Equals(method, o.method) && this.left.PerformMatch(o.left, ref match) && this.right.PerformMatch(o.right, ref match);
 		}
 	}
 }

ICSharpCode.Decompiler/IL/Instructions.tt

@@ -1081,12 +1081,14 @@ protected override void Disconnected()
 		opCode.Members.Add("readonly IMethod method;");
 		opCode.ConstructorBody.Add("this.method = method;");
 		opCode.MatchParameters.Add(new MatchParamInfo { TypeName = "IMethod", Name = "method", FieldName = "Method" });
-		opCode.PerformMatchConditions.Add("method.Equals(o.method)");
+		opCode.PerformMatchConditions.Add("object.Equals(method, o.method)");
 		opCode.Members.Add("/// <summary>Returns the method operand.</summary>" + Environment.NewLine
 						+ "public IMethod Method { get { return method; } }");
 		opCode.GenerateWriteTo = true;
-		opCode.WriteOperand.Add("output.Write(' ');");
-		opCode.WriteOperand.Add("method.WriteTo(output);");
+		opCode.WriteOperand.Add("if (method != null) {");
+		opCode.WriteOperand.Add("\toutput.Write(' ');");
+		opCode.WriteOperand.Add("\tmethod.WriteTo(output);");
+		opCode.WriteOperand.Add("}");
 		opCode.Interfaces.Add("IInstructionWithMethodOperand");
 	};