Description

The source generator for LoggerMessage does not work if the logger is injected from the primary constructor.

Reproduction Steps

Create the project.

• dotnet new classlib
• dotnet add package Microsoft.Extensions.Logging --version 8.0.0-preview.7.23375.6

Add the following c# file to the project.

using Microsoft.Extensions.Logging;

namespace Test;

public partial class LoggerFromPrimaryConstructor(ILogger<LoggerFromPrimaryConstructor> logger)
{
    [LoggerMessage(Level = LogLevel.Debug, Message = "This is a test")]
    public partial void LogTest();
}

Expected behavior

The source generator emits code with similar behaviour as if I had written the following.

public partial class LogWithExplicitProperty
{
    private readonly ILogger<LoggerFromPrimaryConstructor> logger;

    public LogWithExplicitProperty(ILogger<LoggerFromPrimaryConstructor> logger)
    {
        this.logger = logger;
    }

    [LoggerMessage(Level = LogLevel.Debug, Message = "This is a test")]
    public partial void LogTest();
}

Actual behavior

Compilation fails with error SYSLIB1019: Couldn't find a field of type Microsoft.Extensions.Logging.ILogger in class LoggerFromPrimaryConstructor.

I also got error CS1525: Invalid expression term '<' in another project where the source generator did find the logger for some reason, but generated incorrect code that referenced the logger by the symbol <logger>P. I assume this is the generated field name? I could not reproduce it however.

Regression?

This is not a regression, as primary constructors are not GA.

Known Workarounds

Use a regular constructor instead of a primary constructor.

Configuration

I am using .NET 8 preview 7 on Windows 10 Enterprise 22H2 x64.

Other information

No response