Generated File Missing Logging Method – Need Help

[MiKorH]

UPD: code snippet was updated

Hello! Thank you for your very useful library!

I tried to use it, but unfortunately it doesn’t seem to work as expected.

Here’s a minimal example with just two files: a .csproj and a .cs file with a benchmark.
It generates the InterceptsAttribute.g.cs file, but it only contains the InterceptsLocationAttribute class — the logging method is not generated.

Could you please advise what might be wrong or missing?

csproj declaration:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net8.0</TargetFramework>
    <Nullable>enable</Nullable>
    <LangVersion>12</LangVersion>
  </PropertyGroup>

  <PropertyGroup>
    <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
    <CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)\Generated</CompilerGeneratedFilesOutputPath>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="BenchmarkDotNet" Version="0.14.0" />
    <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="8.0.1" />
    <PackageReference Include="stbychkov.AutoLoggerMessage" Version="1.0.10">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
  </ItemGroup>

</Project>

using System;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;
using Microsoft.Extensions.Logging;

BenchmarkRunner.Run<AutoLoggingBenchmark>();

[MemoryDiagnoser]
[WarmupCount(50)]
[IterationCount(50)]
[InvocationCount(100)]
public class AutoLoggingBenchmark
{
    private readonly ILogger _logger;

    public AutoLoggingBenchmark()
    {
        var loggerFactory = LoggerFactory.Create(builder =>
            builder.AddSimpleConsole().SetMinimumLevel(LogLevel.Trace)
        );
        _logger = loggerFactory.CreateLogger<Program>();
    }

    [Benchmark(Baseline = true)]
    public void BuiltInLogging()
    {
        for (int t = 0; t < 100; t++)
            LoggerExtensions.LogDebug(_logger, "Test log started at {time} with {Id}", DateTime.Now, t);
    }

    [Benchmark]
    public void DefinedLoggerLogging()
    {
        for (int t = 0; t < 100; t++)
            DefinedMessagesLogger.DefinedDebug(_logger, DateTime.Now, t);
    }

    [Benchmark]
    public void AutoLoggerMessageLogging()
    {
        for (int t = 0; t < 100; t++)
            LoggerExtensions.LogDebug(_logger, "Test log started at {time} with {Id}", DateTime.Now, t);
    }
}

public static partial class DefinedMessagesLogger
{
    [LoggerMessage(Level = LogLevel.Debug, Message = "Test log started at {time} with {Id}")]
    public static partial void DefinedDebug(ILogger logger, DateTime time, int id);
}

Generated file InterceptorAttribute.g.cs:

// <auto-generated/>
#nullable enable

using System;

namespace System.Runtime.CompilerServices
{
    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("AutoLoggerMessageGenerator", "1.0.10.0")]
    [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Never)]
    [AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
    internal sealed class InterceptsLocationAttribute : Attribute
    {
        public InterceptsLocationAttribute(int version, string data) {}
    }
}

Results:

InvocationCount=100  IterationCount=50  UnrollFactor=1  
WarmupCount=50  

Method	Mean	Error	StdDev	Ratio	RatioSD	Allocated	Alloc Ratio
BuiltInLogging	65.94 ms	1.634 ms	3.300 ms	1.00	0.07	36.72 KB	1.00
DefinedLoggerLogging	65.31 ms	1.471 ms	2.972 ms	0.99	0.07	30.4 KB	0.83
AutoLoggerMessageLogging	63.88 ms	1.453 ms	2.935 ms	0.97	0.06	36.72 KB	1.00

Project files are attached. Thank you in advance!

[stbychkov]

Hey, @MiKorH!

Thanks for asking the question. There are a couple of things going on here:

1. Project setup

You’ve manually specified what to include from the library:

<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

That’s almost right, but you're missing compile, which is important here. The *.BuildOutput.dll library contains the GenericLoggerExtensions class, and it needs to be available at compile time.

So you should update it to:

<IncludeAssets>compile; runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

Alternatively, if you don’t need fine-grained control, you can skip the IncludeAssets altogether - it works out of the box too 😉

<PackageReference Include="stbychkov.AutoLoggerMessage" Version="1.0.10" />

2. Benchmark method

You're currently calling the extension method directly:

LoggerExtensions.LogDebug(_logger, "Test log started at {time} with {Id}", DateTime.Now, t);

But the library is designed to detect usage of the standard ILogger.Log* methods instead. That’s actually intentional as direct calls to the extension method serve as a fallback if generation fails or if you want to use the default behavior manually (I mentioned it here).

So to trigger source generation correctly, your benchmark for AutoLoggerMessage should look like this:

_logger.LogDebug("Test log started at {time} with {Id}", DateTime.Now, t);

3. Benchmark isolation

It’s a good idea to isolate your benchmark from external dependencies like SimpleLogger in your case, because:

• There might be extra allocations during the formatting of parameters (DateTime in your case)
• String construction for logs adds even more overhead
• Any I/O (like console or file writes) can distort the actual performance measurements

You can check out this example benchmark for the reference.

Hope that helps!

[MiKorH]

@stbychkov thank you for the detailed answer!
The problem was missing compile inclusion (it wasn’t intentional, Rider automatically added it when including the NuGet package).
As for the double calling of LoggerExtensions — I got confused while trying different options to get the code working.

[MiKorH]

And one more thing: I still have an error in my work project (not in presented simple test):

4>Interceptors.g.cs(15,10): Error CS9137: The 'interceptors' experimental feature is not enabled in this namespace. Add '$(InterceptorsPreviewNamespaces);Microsoft.Extensions.Logging.AutoLoggerMessage' to your project.

The project built successfully after I added that to the config (but not needed for the simple test console project presented above):

<InterceptorsPreviewNamespaces>$(InterceptorsPreviewNamespaces);Microsoft.Extensions.Logging.AutoLoggerMessage</InterceptorsPreviewNamespaces> 

[stbychkov]

Hi @MiKorH,

I tried reproducing the issue across several projects with the latest version, and based on my results, adding the attribute is not required as I already specified custom build targets (here).

If you're still encountering the issue, could you please create a new issue and provide a minimal reproducible example along with the installed SDK version and the version of the library you are using?

Thanks!

[MiKorH]

@stbychkov I noticed that the error is encountered only in Release and disappears when I add the InterceptorsPreviewNamespaces setting.
In Debug, it works correctly with or without InterceptorsPreviewNamespaces.

UPD: It relates to my work project. My simple console test (posted above) doesn't have the same problem.

UPD2: Now this error disappeared again... This is a strange sporadic problem, I encountered it a few times in the different situations... I think the more reliable way for library consumers is adding InterceptorsPreviewNamespaces