Remove dependencies

[adamsitnik]

At the cost of requiring the users to provide explicit custom parser for Uri, IPAddress and IPEndPoint and a removal of non-generic collections support I was able to remove following dependencies:

- System.Private.Uri.dll
- System.Net.Primitives.dll
- System.Collections.dll
- System.Collections.Concurrent.dll
- System.Runtime.Serialization.Formatters.dll

The most tricky part was removing dependency to System.Collections.dll, which was caused by the fact that we were using Stack<T> (it's generic, but not defined in System.Collections.Generic.dll or CoreLib...)

The only dependency that an app that uses S.CL has and a Hello World app does not, is System.Linq (and S.CL of course).

For following app:

using System;
using System.CommandLine;

public class Program
{
    static void Run(bool boolean, string text)
    {
        Console.WriteLine($"Bool option: {text}");
        Console.WriteLine($"String option: {boolean}");
    }

    private static int Main(string[] args)
    {
        Option<bool> boolOption = new Option<bool>("--bool", "-b") { Description = "Bool option" };
        Option<string> stringOption = new Option<string>("--string", "-s") { Description = "String option" };

        RootCommand command = new ()
        {
            boolOption,
            stringOption,
        };

        command.SetAction(ctx => Run(ctx.GetValue(boolOption), ctx.GetValue(stringOption)));

        return new CommandLineConfiguration(command).Invoke(args);
    }
}

And

dotnet publish -c Release -r win-x64 /p:PublishTrimmed=true

The number of files dropped from 34 to 29, size from 17.5 MB to 17.3.
For NativeAOT app the size dropped from 4.65 MB to 4.5 MB.

fixes #1794

Useful link for repeating the process in the future: dotnet/runtime#78671 (comment)

[adamsitnik]

Updated perf numbers for startup scenario benchmarks (https://github.com/adamsitnik/commandline-perf/tree/update):

Default settings

BenchmarkDotNet=v0.13.4, OS=Windows 11 (10.0.22621.1413)
AMD Ryzen Threadripper PRO 3945WX 12-Cores, 1 CPU, 24 logical and 12 physical cores
.NET SDK=8.0.100-alpha.1.22558.1
[Host] : .NET 7.0.4 (7.0.423.11508), X64 RyuJIT AVX2
Job-LDBVHT : .NET 7.0.4 (7.0.423.11508), X64 RyuJIT AVX2

EvaluateOverhead=False OutlierMode=DontRemove InvocationCount=1
IterationCount=100 UnrollFactor=1 WarmupCount=3

Method	Args	Mean	Error	StdDev	Median	Ratio	RatioSD
Empty		70.30 ms	1.166 ms	3.437 ms	70.32 ms	0.83	0.05
EmptyAOT		14.95 ms	0.436 ms	1.286 ms	14.67 ms	0.18	0.02
Corefxlab		86.82 ms	1.185 ms	3.493 ms	85.91 ms	1.03	0.04
SystemCommandLine2021		117.35 ms	1.117 ms	3.293 ms	116.69 ms	1.39	0.05
SystemCommandLine2022		97.13 ms	1.120 ms	3.301 ms	96.44 ms	1.15	0.04
SystemCommandLineNow		84.32 ms	0.755 ms	2.227 ms	83.83 ms	1.00	0.00
SystemCommandLineNowR2R		79.25 ms	0.830 ms	2.448 ms	78.71 ms	0.94	0.04
SystemCommandLineNowAOT		15.04 ms	0.242 ms	0.714 ms	14.86 ms	0.18	0.01
Empty	--bool -s test	66.51 ms	0.563 ms	1.661 ms	66.47 ms	0.75	0.03
EmptyAOT	--bool -s test	13.49 ms	0.221 ms	0.653 ms	13.39 ms	0.15	0.01
Corefxlab	--bool -s test	86.60 ms	0.934 ms	2.753 ms	85.86 ms	0.97	0.04
SystemCommandLine2021	--bool -s test	119.95 ms	0.913 ms	2.691 ms	119.66 ms	1.34	0.05
SystemCommandLine2022	--bool -s test	100.62 ms	0.561 ms	1.654 ms	100.22 ms	1.13	0.04
SystemCommandLineNow	--bool -s test	89.25 ms	0.869 ms	2.563 ms	88.66 ms	1.00	0.00
SystemCommandLineNowR2R	--bool -s test	82.15 ms	0.921 ms	2.717 ms	81.67 ms	0.92	0.04
SystemCommandLineNowAOT	--bool -s test	15.03 ms	0.253 ms	0.747 ms	14.93 ms	0.17	0.01

[eerhardt]

I don't understand why the referenced issue is justification for suppressing these warnings. It might be better if we wrote it out here.

I believe you could fix IL2091 by annotating the T with [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)]. See https://learn.microsoft.com/en-us/dotnet/core/deploying/trimming/fixing-warnings#dynamicallyaccessedmembers

[eerhardt]

We should be able to use dotnet/runtime#76478 once it is implemented in .NET 8. That will allow us to do this without a warning.

[eerhardt]

This isn't guaranteed to work in a NativeAOT app. Just because the app uses a IList<double>, it doesn't mean that double[]'s code is going to get preserved/generated.