How can I compare a ClassDeclarationSyntax object against an IdentifierNameSyntax object?

Question

I'm writing a source generator in C#, and I've got 2 objects that I need to compare to see if they relate to the same class, but I can't find a way to do it.

My first object is an instance of ClassDeclarationSyntax. This is coming from my custom ISyntaxContextReceiver to find classes that match specific conditions.

Elsewhere in my generator I have an IdentifierNameSyntax object, which is coming from looking at the types within a TypeOfExpressionSyntax that I find within a different class's list of attributes.

I need to compare the two objects here to see if they are talking about the same thing.

With the IdentifierNameSyntax I can get the type information by using the semantic model:

ITypeSymbol semanticType = semanticModel.GetTypeInfo(targetType).Type;

But I don't know how to compare this ITypeSymbol against ClassDeclarationSyntax either.

Is there a way to do this, or is there a way to get the semantic model type information for a ClassDeclarationSyntax object?

I think you're looking for `semanticModel.GetDeclaredSymbol(classDeclaration)`, no? — Kirk Woll, May 17 '22 at 22:01
Yep, that's exactly it. Thank you @KirkWoll - if you want to pop this as an answer, I'll mark it as accepted. — Jamie Burns, May 23 '22 at 09:06
Cool, glad that helped. I've provided an answer so you can close the loop on this question. — Kirk Woll, May 23 '22 at 15:14

score 1 · Accepted Answer · answered May 23 '22 at 15:13

The method you are looking for is GetDeclaredSymbol on semanticModel. As you can see from the documentation, there are huge number of overloads which will allow you to get the associated symbol information for not only classes, but also fields, methods, properties, events, parameters, and so forth. Definitely a method you'll want to keep in your back pocket!

How can I compare a ClassDeclarationSyntax object against an IdentifierNameSyntax object?

1 Answers1