Trying to run a script in 32 bits mode on a 64 bits host.

[RomainTT]

Hello Oleg and thank you for your work.

I am struggling with this and I come to you in hope of getting a better understanding of the infrastructure. The whole C# ecosystem is new for me. I read your documentation carefully but I am missing something.

Environment

• Windows 11 (x64)
• .NET SDK 9.0.203 (x64)
• Visual Studio Code 1.99.3
• CS-Script plugin 2.3.0
• cs-script.cli 4.9.5 and cs-syntaxer 3.2.4 installed via command line.

Project

• A bunch of .cs files (a main one as entrypoint)
• Some homemade .dll files, next to the main script. Those DLL are compiled for 32 bits architectures. They are used by the main script.

Simplified example:

//css_host /platform:x86

//css_include ./other.cs

//css_nuget SomePackage

using MyDLL;

public static class Program
{
    static void Main()
    {
        // Those lines help me to know if the process is running in 32 or 64 mode
       if (IntPtr.Size == 4)
           Console.WriteLine("Running as 32 bits");
       else if (IntPtr.Size == 8)
           Console.WriteLine("Running as 64 bits");

        // Calling the DLL (it crashes)
        MyDLLMethod();
    }
}

Issue at runtime

Running the script gives:

> css '.\main.cs'
Running as 64 bits
Error: Specified file could not be executed.

An attempt was made to load a program with an incorrect format. (0x8007000B)

Trying to solve it

I thought that //css_host /platform:x86 was enough. But as it does not work I tried to compile with some compiler options:

> css -co:/platform:x86 '.\main.cs'

But it fails because the DLL is not found.

I tried to find a x86 binary version of css.exe on my system, but I didn’t.

Honestly, I’m lost in documentation (.NET, cs-script, stackoverflow…), and I don’t know what I am missing. Thank you for your help.

[oleg-shilo]

Hi @RomainTT,

Your thoughts about -co: /platform:86 are exactly what you need to do. However, for some reason, your host app is still x64. And this is the cause of your problem.

You will need to solve this problem first, and then the rest of the challenges will be easier.

Interestingly enough, I ran your test script (without mydll) and it works OK. Though I did a few tiny modifications:
forced the engine to be dotnet.exe as it is the only one compatible with x86 and moved -co:... in the script itself:

test.zip

I have attached the script.

Let me know if you still need assistance with loading that mydll.

[RomainTT]

Thank you very much for your reply. I can reproduce your result with your modified script.

Before trying to load my DLL, I need to add nuget packages. For x64 it seems to work, but not for x86. Here are some details:

I am adding log4net to this very simple example.

x64 version

//css_ng dotnet
//css_nuget log4net

public static class Program
{
    static void Main()
    {
       if (IntPtr.Size == 4)
           Console.WriteLine("Running as 32 bits");
       else if (IntPtr.Size == 8)
           Console.WriteLine("Running as 64 bits");

        log4net.Config.BasicConfigurator.Configure();
        log4net.LogManager.GetLogger("Program").Info("Hello!");
    }
}

Here is the result when running it with the command line css:

PS C:\Users\my.name\my\project> css '.\main.cs'
Restoring packages...
   log4net
Mapping packages to assemblies...
Running as 64 bits
32 [1] INFO Program (null) - Hello!

x86 version

//css_ng dotnet
//css_co /platform:x86
//css_nuget log4net

// …
// same code than before
// …

Here is the result when running it with the command line css:

PS C:\Users\my.name\my\project> css '.\main.cs'
Restoring packages...
   log4net
Mapping packages to assemblies...
Unhandled exception. System.IO.FileNotFoundException: Could not load file or assembly 'log4net, Version=3.0.4.0, Culture=neutral, PublicKeyToken=669e0ddf0bb1aa2a'.
File name: 'log4net, Version=3.0.4.0, Culture=neutral, PublicKeyToken=669e0ddf0bb1aa2a'
   at Program.Main()

Again, I can’t find what I am missing here. I suppose I must ensure that nuget packages are downloaded for x86 architecture.

[oleg-shilo]

OK, I know the answer.
The problem is caused by the assembly probing algorithm for the running script being designed around the execution from the script engine exe, which plays nicely with assembly probing. However, in the case of x86 the host app is a different exe, which has no idea about resolving assemblies required by the script. This is something that I need to revisit and address in the next release.

Let's unblock you first, and then I will proceed with the design update as a separate issue.

This is what you need to do. Since your script host does not have assembly resolving implemented, it's easier to preload the "unresolvable assembly" manually. In this case, it is log4net.dll.

This is how you can achieve it:

//css_ng dotnet
//css_co /platform:x86
//css_nuget log4net
using System.Reflection;

using System;

public static class Program
{
    static void Main()
    {
        Assembly.LoadFrom(Environment.ExpandEnvironmentVariables(
            @"%USERPROFILE%\.nuget\packages\log4net\3.0.4\lib\netstandard2.0\log4net.dll"));
        main();
    }

    static void main()
    {
        // Those lines help me to know if the process is running in 32 or 64 mode
        if (IntPtr.Size == 4)
            Console.WriteLine("Running as 32 bits");
        else if (IntPtr.Size == 8)
            Console.WriteLine("Running as 64 bits");

        Console.WriteLine(typeof(log4net.Config.BasicConfigurator).Assembly.Location);
    }
}

And the next release will have the proper fix for this so you will be able to remove this workaround.

[oleg-shilo]

Done, you can get the latest v4.9.6 release from nuget.org:

dotnet tool install --global cs-script.cli

It will execute the script below without the need for any workaround:

//css_ng dotnet
//css_co /platform:x86
//css_nuget log4net

using System;

public static class Program
{
    static void Main()
    {
        // Those lines help me to know if the process is running in 32 or 64 mode
        if (IntPtr.Size == 4)
            Console.WriteLine("Running as 32 bits");
        else if (IntPtr.Size == 8)
            Console.WriteLine("Running as 64 bits");

        Console.WriteLine(typeof(log4net.Config.BasicConfigurator).Assembly.Location);
    }
}

[RomainTT]

Excellent! It runs like a charm on my system too with v4.9.6.

Thank you very much for your help and your quick release.

[oleg-shilo]

Glad we sorted it out so quickly