Add DelayExceptions flag to LdElema and LdFlda.

ICSharpCode.Decompiler/IL/ILReader.cs

@@ -953,7 +953,7 @@ namespace ICSharpCode.Decompiler.IL
 		
 		private ILInstruction LdElem(IType type)
 		{
-			return Push(new LdObj(new LdElema(indices: Pop(), array: Pop(), type: type), type));
+			return Push(new LdObj(new LdElema(indices: Pop(), array: Pop(), type: type) { DelayExceptions = true }, type));
 		}
 		
 		private ILInstruction StElem(IType type)
@@ -961,7 +961,7 @@ namespace ICSharpCode.Decompiler.IL
 			var value = Pop(type.GetStackType());
 			var index = Pop();
 			var array = Pop();
-			return new StObj(new LdElema(type, array, index), value, type);
+			return new StObj(new LdElema(type, array, index) { DelayExceptions = true }, value, type);
 		}
 
 		ILInstruction InitObj(ILInstruction target, IType type)

ICSharpCode.Decompiler/IL/Instructions.cs

@@ -2177,17 +2177,18 @@ namespace ICSharpCode.Decompiler.IL
 			clone.Target = this.target.Clone();
 			return clone;
 		}
+		public bool DelayExceptions;
 		readonly IField field;
 		/// <summary>Returns the field operand.</summary>
 		public IField Field { get { return field; } }
 		public override StackType ResultType { get { return StackType.Ref; } }
 		protected override InstructionFlags ComputeFlags()
 		{
-			return target.Flags | InstructionFlags.MayThrow;
+			return target.Flags | (DelayExceptions ? InstructionFlags.None : InstructionFlags.MayThrow);
 		}
 		public override InstructionFlags DirectFlags {
 			get {
-				return InstructionFlags.MayThrow;
+				return (DelayExceptions ? InstructionFlags.None : InstructionFlags.MayThrow);
 			}
 		}
 		public override void WriteTo(ITextOutput output)
@@ -3223,16 +3224,17 @@ namespace ICSharpCode.Decompiler.IL
 			clone.Indices.AddRange(this.Indices.Select(arg => arg.Clone()));
 			return clone;
 		}
+		public bool DelayExceptions;
 		public override StackType ResultType { get { return StackType.Ref; } }
 		/// <summary>Gets whether the 'readonly' prefix was applied to this instruction.</summary>
 		public bool IsReadOnly { get; set; }
 		protected override InstructionFlags ComputeFlags()
 		{
-			return array.Flags | Indices.Aggregate(InstructionFlags.None, (f, arg) => f | arg.Flags) | InstructionFlags.MayThrow;
+			return array.Flags | Indices.Aggregate(InstructionFlags.None, (f, arg) => f | arg.Flags) | (DelayExceptions ? InstructionFlags.None : InstructionFlags.MayThrow);
 		}
 		public override InstructionFlags DirectFlags {
 			get {
-				return InstructionFlags.MayThrow;
+				return (DelayExceptions ? InstructionFlags.None : InstructionFlags.MayThrow);
 			}
 		}
 		public override void WriteTo(ITextOutput output)

ICSharpCode.Decompiler/IL/Instructions.tt

@@ -150,7 +150,7 @@
 			CustomClassName("LdFld"), CustomArguments("target"), MemoryAccess, SupportsVolatilePrefix, SupportsUnalignedPrefix, MayThrow,
 			HasFieldOperand, ResultType("field.Type.GetStackType()")),
 		new OpCode("ldflda", "Load address of instance field",
-			CustomClassName("LdFlda"), CustomArguments("target"), MayThrow, HasFieldOperand, ResultType("Ref")),
+			CustomClassName("LdFlda"), CustomArguments("target"), MayThrowIfNotDelayed, HasFieldOperand, ResultType("Ref")),
 		new OpCode("stfld", "Store value to instance field",
 			CustomClassName("StFld"), CustomArguments("target", "value"),
 			MemoryAccess, SupportsVolatilePrefix, SupportsUnalignedPrefix, MayThrow, HasFieldOperand,
@@ -199,7 +199,7 @@
 			CustomClassName("LdLen"), CustomArguments("array"), CustomConstructor, CustomWriteTo, MayThrow),
 		new OpCode("ldelema", "Load address of array element.",
 			CustomClassName("LdElema"), HasTypeOperand, CustomChildren(new [] { new ArgumentInfo("array"), new ArgumentInfo("indices") { IsCollection = true } }, true),
-			MayThrow, ResultType("Ref"), SupportsReadonlyPrefix),
+			MayThrowIfNotDelayed, ResultType("Ref"), SupportsReadonlyPrefix),
 		new OpCode("array.to.pointer", "Converts an array pointer (O) to a reference to the first element, or to a null reference if the array is null or empty." + Environment.NewLine
 			+ "Also used to convert a string to a reference to the first character.",
 			CustomArguments("array"), ResultType("Ref")),
@@ -534,6 +534,10 @@ namespace ICSharpCode.Decompiler.IL
 	// Instructions without this trait must evaluate all arguments left-to-right before having any effect of their own.
 	static Action<OpCode> ControlFlow = HasFlag("InstructionFlags.ControlFlow");
 	
+	static Action<OpCode> MayThrowIfNotDelayed = HasFlag("(DelayExceptions ? InstructionFlags.None : InstructionFlags.MayThrow)") + (opCode => {
+		opCode.Members.Add("public bool DelayExceptions;");
+	});
+	
 	static Action<OpCode> BaseClass(string name)
 	{
 		return opCode => {