How can I access symbols of inaccessible members in referenced assemblies from a source generator?

[eiriktsarpalis]

I recently hit this issue while working on one of my source generators. The only way I'm able to work around the issue is by specifying a MetadataImportOptions.All when creating the compilation, however source generators generally do not create or own the compilations they are consuming. Is there a best practice when it comes to dealing with this problem in source generators?

cc @jcouv

[jcouv]

Tagging @333fred @RikkiGibson @chsienki for brainstorming.
Maybe we could expose some control of MetadataImportOptions via csproj and command-line.

[333fred]

I don't know of a way to make this work. IMO, it's not particularly good practice to have a private field/property that must be read by a downstream project; that generally feels like an encapsulation break. If it needs to be accessed, it should be visible.

[eiriktsarpalis]

I wouldn't disagree with that. That being said STJ has shipped the JsonInclude attribute that lets users explicitly include individual non-public properties into the serialization contract. It works well in reflection but not so much with the source generator. It's been popular enough that we've been considering extending it there via use of unsafe accessors.