2022-02-20 IL hello world.md

mkdir il-hello && cd $_
dotnet new sln
dotnet new globaljson

Add

{
    "msbuild-sdks": 
    {
      "Microsoft.NET.Sdk.IL": "6.0.0"
    }
}

to global.json.

mkdir SampleIL
touch SampleIL/SampleIL.ilproj
touch SampleIL/hello.il

modify SampleIL.ilproj:

<Project Sdk="Microsoft.NET.Sdk.IL">
    <PropertyGroup>
        <TargetFramework>netstandard2.0</TargetFramework>
     </PropertyGroup>
</Project>

add

.assembly extern mscorlib
{
    .ver 4:0:0:0
    .publickeytoken = (B7 7A 5C 56 19 34 E0 89)
}

.assembly SampleIL
{
  .ver 1:0:0:0
}
 
.module SampleIL.dll

.class public auto ansi beforefieldinit Hello
  extends System.Object
{
  .method public hidebysig static string World() cil managed
  {
    ldstr      "Hello World!"
    ret
  }
}

to hello.il.

Now you have library that you could use for example from ordinary console project.

dotnet sln il-hello.sln add SampleIL/SampleIL.ilproj
dotnet new console --output ConsoleApp --framework net6.0
dotnet sln il-hello.sln add ConsoleApp/ConsoleApp.csproj
dotnet add ConsoleApp/ConsoleApp.csproj reference SampleIL/SampleIL.ilproj

replace Program.cs with

Console.WriteLine(Hello.World());

Build and run

dotnet build
dotnet run --project ConsoleApp/ConsoleApp.csproj 

TODO:

1. there is

hello.il(10): warning : Reference to undeclared extern assembly 'mscorlib'. Attempting autodetect

warning if remove extern mscorlib block form hello.il