Excess code generated for lambdas

[Craig]

I have the following line of code in my C# application:

ArgumentHelpers.ThrowIfNullOrWhitespace(() => args[0]);

JustDecompile shows the following decompilation:

ArgumentHelpers.ThrowIfNullOrWhitespace(new Expression<Func<string>>[] { Expression.Lambda<Func<string>>(Expression.ArrayIndex(Expression.Field(Expression.Constant(variable, typeof(Program.<>c__DisplayClass0_0)), FieldInfo.GetFieldFromHandle(typeof(Program.<>c__DisplayClass0_0).GetField("args").FieldHandle)), Expression.Constant(0, typeof(int))), new ParameterExpression[0]) });

ILSpy shows the following decompilation:

ArgumentHelpers.ThrowIfNullOrWhitespace(new Expression<Func<string>>[]<br>{<br>    () => args[0]<br>});

It would be nice if JustDecompile generated the more concise syntax.

[Alexander]

Hi,

Thank you for letting us know about this problem.

Would it be possible that you provide us with some more details about your code, such as the signature of the ThrowIfNullOrWhitespace method and the type of the args variable? By doing that you will enable us to reproduce exactly the problem you have.

Thank you in advance.

Regards,
Alexander
Telerik

[Craig]

I've been trying to get a copy of the assembly to Tsviatko Yovtchev. I think we may have finally succeeded using ftp. Here's the actual code, boiled down to a very simple p.o.c.

using System;
using System.Linq.Expressions;

namespace ConsoleApplication5
{
    public static class ArgumentHelpers
    {
        private static TObject GetReferenceValue<TObject>(Expression<Func<TObject>> reference)
        { return reference.Compile().Invoke(); }

        public static void ThrowIfNullOrWhitespace(params Expression<Func<string>>[] argumentSelector)
        {
            foreach (var selector in argumentSelector)
            {
                if (String.IsNullOrWhiteSpace(GetReferenceValue(selector)))
                { throw new ArgumentException("value cannot be null or whitespace", nameof(selector)); }
            }
        }
    }
}

namespace ConsoleApplication5
{
    class Program
    {
        static void Main(string[] args)
        {
            ArgumentHelpers.ThrowIfNullOrWhitespace(() => args[0]);
        }
    }
}

[Alexander]

Hi,

Thank you for sending us the code. The bug is now reproduced and added to our backlog.

Regards,
Alexander
Telerik