Question Support Roslyn analyzers in Unity projects

About the fix, which Unity version will it be available in?

 

Additionally, can you update us on when the Temp folder error will be solved, and which versions? Currently, as far as I know, this is blocking anyone using Roslyn Analyzers in a large project.

 

Sorry for being completely noob here. But I have a really hard time following this documentation: https://docs.unity3d.com/2020.2/Documentation/Manual/roslyn-analyzers.html

How do I install NuGet packages in Unity? I had to do so through Rider, and then copy the DLLs manually. But in doing do, all the DLLs dependencies are missing. I ended up having to import https://github.com/mwahnish/Unity-Roslyn to get all the dependencies. Is this what you guys have been doing?

Also, I cannot get Rider to use the analyzers. It says that its unable to load the requested types.


Can somebody create a step-by-step guide in how to get Roslyn Analyzers working?

 

I will try to do explain each step really quickly, because I agree the documentation may be improved.

For the dependency error that you got, see the end of this message.

Adding a Roslyn Analyzer

Step 1 : Get the

.dll

file(s) for the analyzer you want to add to your Unity project.

1.1. Open your project in your IDE
1.2. Install the NuGet package of your analyzer in your project
1.3. At the root of your project, open the folder "Packages". The NuGet package must be installed in it.
1.4. Search for the

.dll

files for your analyzer in the hierarchy. Some analyzers may use multiple files, so be careful to really select all the useful ones.

Step 2 : Import the

.dll

files to Unity

2.1. Copy your analyzer's

.dll

files into your Assets folder (or any subfolder)
2.2. Select them in the Project windows in Unity and open them in the inspector
2.3. Under "Select platforms for plugin", disable everything like this :



2.4. Set the label for all the files to "RoslynAnalyzer" (at the bottom of the inspector, the little blue icon). You way need to create a new label (just type it and enter). Be careful to make no mistake in the name of the label!



Step 3 : Reimport your scripts

The code analysis may not run right away. In order to trigger it, you may want to reimport your scripts.

To do this, right-click on your folder that stores all the scripts in your game, and click on "Reimport".

You can also "Reimport all" if you don't have one specific folder for your scripts.

Troubleshoots

I got an error that say that a folder is missing in the "Temp" folder

For the moment, you can simply create the missing folder by hand, and the error will disappear. I'm not sure if it's really a permanent fix, but at the moment it seems to work for me.

There are errors in the console that say that some dependencies are missing in my dlls

Not sure about this one, but I had this error when I had a typo in the label name "RoslynAnalyzer". You way need to double-check it.

 

AlphaDreams thank you very much!

I encountered an issue when installing the suggested analyzer from the documentation, where no dependencies were pulled in. This meant that I only ended up with the 3 DLLs mentioned in the documentation, which did not work.

However, if I manually installed the Microsoft.CodeAnalysis.CSharp NuGet package as well, it compiled just fine. That does however result in 40 DLLs imported into Unity. Is that really correct?

 

I'll be honest, I did not test it with the analyzers specified in the documentation.
But even with another analyzer - StyleCop in my case - when I added the dll files in my project there were errors in the console that told me that some dependencies were missing, especially

Microsoft.CodeAnalysis

and two or three other packages.

Like I said in my previous answer, Unity told me that these dependencies were missing only because I had a typo in the label name "RoslynAnalyzer". I fixed it, and now everything runs smoothly, and I didn't had to add any other dlls in the project other than the two first.

I'm clearly not sure about this, but it's possible that Unity resolve these dependencies automatically when you give your dll files the correct label?

Also, don't forget that if you try something and nothing change, you can :

- Reimport you script folder (Right clic in the project window on your folder, then "Reimport")
- Reimport all (Right clic anywhere in the project window, then "Reimport all", but it will take time, especially if you're working on a large project)
- Regenerate the project files ("Edit" > "Preferences" > "External Tools" > "Regenerate Project Files")

It may trigger something that will resolve your problem.

And if someone with more insight about this than me can answer how all this works, it can be great!

 

It's the issue most of the first page of this thread is talking about. It doesn't seem like it was ever addressed or resolved.

 

Thank you all for the information shared so far. Getting the analyser to work in VS2019 was the last piece of the puzzle for me.

For those that are having trouble copying DLLs over from NuGet or want an easier way to maintain their NuGet packages there is NuGetForUnity (https://github.com/GlitchEnzo/NuGetForUnity). I've pulled in both ErrorProne .NET analyzers using NuGetForUnity and it works well.

Just make sure to commit the DLLs to your version control, otherwise you'll have to manually repeat the DLL import on each new checkout.

 

Nice, another half assed non functioning feature that only exists to aggravate the user base.

 

At least in Unity 2020.3.12f1, the analyzer placed under Packages seems to be working.
However, I cannot find any mention of it in the release notes.

What is Unity's position on the analyzer under Packages folder?

I would also like to see support for .editorconfig file for severity settings.

 

I'm posting a PR for Roslyn analyzer support but it's not merged.
Please use it if you are interested.
https://github.com/GlitchEnzo/NuGetForUnity/pull/393

 

@HaraldNielsen I'd like to write custom analyzers/generators in my Unity project. It's a large project that would benefit massively from code generation. What's the best way to go about that? I'd like the generator code to have access to the sources of other selected assemblies, so that project-wide refactorings don't break the source generators.

I could obviously maintain a completely separate project, build it, include the dll in the unity project, label it as RoslynAnalyzer, etc. But that's a massive overhead for small changes.

I could also not use Roslyn Generators, and instead write an editor script that triggers on compilation and writes a source file before triggering another compilation. But that would require two compilations each time, which would be a constant annoying overhead in a large project.

Are there any better ways to get code generation for source files in Unity? Can I just write my analyzer/generator in a folder with an `.asmdef` and maybe include the dll as `-analyzer:` as compiler arg or something?

 

Did you ever find a way to ignore specific assemblies?

 

Hey @HaraldNielsen, I just started to look into Roslyn Analyzers and after adding some DLLs and making them work correctly, I'm now wondering if there is any way to write my analyzers in the same source project of my game?

I would make use of AssemblyDefinitions to encapsulate and organize everything and maybe also create a Package out of it.

 

Thanks for sharing that info @HaraldNielsen
I'm looking forward to using it like that.

 

Our company has just run into this problem recently when we were trying to nail down a good enough process of building Unity packages for internal use. Supporting analyzers and source generators inside a Unity project will ease our work greatly as we don't have much manpower to maintain and develop different kinds of projects. Atm we have to resort to some tricks to make codegen developable inside a Unity package (even though we have to tolerate harmless errors constantly logged in the Console view).

 

@HaraldNielsen I am sorry to bother you again, but source generators do not work for me.

We have upgraded to Unity 2021.2.2f1. I have started a new analyzer/generator project as a separate project, compiled it, moved the DLL into the assets folder and given it the `RoslynAnalyzer` asset tag.

The default analyzer works fine (in Rider), but the generator does not seem to be triggered. No logs are forwarded, no diagnostics displayed. The IDE picks up the generated code, but Unity neither sees it nor compiles it. The generator itself has unit tests that work, and the emitted output looks fine.

Could you please provide a tutorial or maybe even an example of how to get a custom Source Generator to work properly within Unity? This is a blocking issue for some features, as alternatives to code generation are a lot less elegant.

 

@HaraldNielsen

Is there any way to package a Roslyn Generator in a unity package (UPM package not *.unitypackage file)?

My generator works when it is in the Assets folder but when I try to create a package with the dlls that are needed for it to work, and put them in the packages folder or import them using package manager the generator doesn't work.

Is there something extra that needs to be done in order for generators to work when distributed through UPM packages?

If it helps here's the generator repository. It's a small open source ECS generator library.
I am trying to distribute it as a package (on top of the *.unitypackage file) as it's a feature that has been requested by some of my library users.

It would make their repositories cleaner and updating the library easier.

I am attaching a zip of the package folder along with it's meta files to make it easier to identify if I am doing something wrong.

 

You are right it does work when I did it in a clean project.
I must have had some library folder garbage or something else must have been happening for it not to work.
Thank you so much for pinging me to do the bare minimum test.

If anyone would still be interested here is the repo with 2 ways of using the generator one from internal asset folder and another one with the package approach.

 

I just had time to get back to this. I can't find the `Microsoft.CodeAnalysis.Analyzers` dll in neither 2021.2 nor 2022.1:



Path to 2022.1: `C:\Program Files\Unity\2022.1.0b4\Editor\Data\DotNetSdkRoslyn` <- this seems to correspond to what you wrote.

I assume that referencing works like in a managed plugin (https://docs.unity3d.com/Manual/UsingDLL.html)?

Alternatively, can I just include the right versions of those plugins in NuGet? And if yes, could you please tell me the version for the `Microsoft.CodeAnalysis.Analyzers` dependency? The others are on 3.9.0. Thanks!

@HaraldNielsen

 

Because the edit post feature does not work: A small example project for a Source Generator that runs with Unity 2021.1.2.2f1 would be immensely appreciated and would solve my problems for the foreseeable future.

 

Alright, I got it I think:

1. Create a netstandard2.0 class library project
2. Explicitly add Microsoft.CodeAnalysis.CSharp version 3.9.0 (the same Unity uses) from NuGet
3. Don't have any other fancy dependencies in there like I had with the original analyzer template that I tried to use
4. Follow Unity's import steps (RoslynAnalyzer asset label, etc)
5. Restart Unity and the IDE twice or so until it works

 

Hi, I'm enjoying using analyzers in my project, and it's nice being able to set some warnings as errors. However, I was wanting to fail a test or build if there were specific errors thrown by the analyzers (for CI purposes). Is there a way to do that?

 

Hi! Can anybody explain please, if it is correct that I can't import Microsoft.CodeAnalysis and then write a SourceGenerator with attribute [Generator] in Unity, but instead of this I must have a precompiled dll with all my SourceGenerators there? I see that generators with attribute work when they are inside dll, and they do not work in classes outside it. Is that correct? The example in documentation has a SourceGenerator inside DLL too.

 

If you add SourceGenerator label to the analyzer DLL, it will also emit the warnings and errors in the Unity console, thus failing a build if there is any error.

However, rulesets / editorconfig seems to be ignored by Unity in this case, so you will need to change the default severity in the analyzer code to make Unity pick it correctly.

 

Only as DLL for now.

 

Hi, I would like to take a look at that repo but it's gone. Do you still have it?

 

Hi Tooster unfortunately it has been removed some time ago. Are you having problems some problems with setting up Roslyn Generators in your project ?
I don't have the old project as it evolved into a bit bigger library.
If you want you can go here and pull the package from the repo or use the UPM approach described in the readme to see how it is set up. It should work in both approaches and if it doesn't you can ping me on the discord channel that's linked in there as well and I can try and help after work.

 

Yeah, I want to write my own source generator inside my (embedded?) package (in the root Packages directory, meant to be exported later as an official package), but nothing I try seems to work. Unfortunately the official docs were greatly unhelpful in setting it up. I am not even sure on which stage I make some mistakes - on the source generator project level, on the unity asset level, the custom package level, maybe on an assembly level or maybe something completely else. Thanks for reply, I'll try to contact you soon.

 

I'm currently using Unity 2022.3 and it does support SG in UPM packages. My setup is based on Unity.Entities package.

 

Ok, I made it work, here are the steps:
1. First of all, ensure that the package has correct structure
2. create another project for source generator. Make sure it targets netstandard2.0. Add Microsoft.CodeAnalysis.CSharp in ver 3.9.0 (it is compatible with unity, contrary with docs)
3. Make sure that your source generator outputs code WITH CORRECT NAMESPACE
4. put the dll in any folder of the package. I put it in the folder with another, sub assembly definition file. Source generator
5. Apply RoslynAnalyzer and SourceGenerator tags to dll. disable any platform and others, like the official guide says.

It is important to understand 2 things:
- source generator applies to all assemblies in subdirectories it is put in
- generated sources must have correct namespaces

When the time comes I'll link my project somewhere here

 

I tried setting up analyzers in Unity but couldn't get around errors of this kind:

These are the analyzers I was trying to set up: