Equality check fails for AttributeSyntax and SyntaxIdentifier when expanding attached macro

[alimyuz]

Description
The equality check for AttributeSyntax and its id property (SyntaxIdentifier) works in assertMacroExpansion() tests, but fails when expanding in "real" source code.

Macro:

@attached(peer, names: arbitrary)
public macro myMacro() = #externalMacro(module: "MyMacroMacros", type: "MyMacro")

public struct MyMacro: PeerMacro {
    public static func expansion<Context, Declaration>(
        of node: AttributeSyntax,
        providingPeersOf declaration: Declaration,
        in context: Context
    ) throws -> [DeclSyntax] where Context : MacroExpansionContext, Declaration : DeclSyntaxProtocol {
        guard let funcDecl = declaration.as(FunctionDeclSyntax.self) else { return [] }
        
        let retrievedAttribute = funcDecl.attributes?.compactMap { attributeSyntax in
            switch attributeSyntax {
            case .attribute(let attribute):
                return attribute
            default:
                return nil
            }
        }.first
        
        if retrievedAttribute != node {
            context.addDiagnostics(from: "retrievedAttribute != node", node: node)
        }
        if retrievedAttribute!.id != node.id {
            context.addDiagnostics(from: "retrievedAttribute!.id != node.id", node: node)
        }
        return []
    }
}

Test passes without any diagnostics. You can see that they are equal in the debugger too.

let testMacros: [String: Macro.Type] = [
    "myMacro": MyMacro.self,
]

final class MyMacroTests: XCTestCase {
    func testMacro() {
        assertMacroExpansion(
            """
            class Example {
                @myMacro
                func foo() {
                }
            }
            """,
            expandedSource:
            """
            class Example {
                func foo() {
                }
            }
            """,
            macros: testMacros
        )
    }
}

The same declaration but in main.swift. Compilation fails with 2 errors.

class Example {
    @myMacro  // 2 errors: "RetrievedAttribute != node" and "RetrievedAttribute!.id != node.id"
    func foo() {}
}

Steps to reproduce

Project archive: MyMacro.zip
Or Github repo

Environment

• swift-driver version: 1.82.2 Apple Swift version 5.9 (swiftlang-5.9.0.114.6 clang-1500.0.27.1)
  Target: arm64-apple-macosx14.0
• Xcode 15.0
  Build version 15A5160n
• Deployment target: iOS 13

[AnthonyLatsis]

cc @ahoppen

[ahoppen]

Tracked in Apple’s issue tracker as rdar://110894406