Ignores @available(tvOS, unavailable) and #if os

[Ernest0-Production]

Describe the bug

When analyzing the code, it is not taken into account that the target may be cross-platform.
Some functions may not be available or used in one of the platforms.

Reproduction
I tried two options

1. Active compilation flags

#if os(iOS)
import OtherDeps // ⚠️ import is unused

class OnlyiOSClass { 
}
#endif

For some reason, the index-store continues to receive information about imports wrapped under an inactive compilation flag...

2. @available keywords

@availalbe(tvOS, unavailable)
class OnlyiOSClass { 
  
   @availalbe(tvOS, unavailable) // ⚠️ init is unused
   init() {}
}

Periphery still sees init in the tvOS index-store. (with clean build)

Workaround

import OtherDeps // ✅ used by OnlyiOSClass

@availalbe(tvOS, unavailable) // ✅ ignored by platform
class OnlyiOSClass {
     
     #if os(iOS) // ✅ ignored by compliation flag
     init() {}
     #endif
}

But this doesn't work if there are uninitialized properties in the class. (compile error)

Environment

periphery version 3.1.0

swift version 6.0

Xcode 16.2
Build version 16C5032a

[Ernest0-Production]

It seems one of the problems with the second option is that Periphery only takes @available(*, unavailable) constructs into account.

[Ernest0-Production]

Another case:

#if !targetEnvironment(simulator)
import FairPlayModule // ⚠️ import unused
#endif  


protocol PlayerProtocol { 
   var someProperty: Int { get } 

   #if !targetEnvironment(simulator)
   var contentLoader: FairPlayModule.ContentLoader
   #endif  
}

[Ernest0-Production]

@ileitch is this a compiler bug or a Periphery bug?

[kimdv]

I also get this warning warning: Initializer 'init(coder:)' is unused for this

    @available(*, unavailable)
    required init?(coder _: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

periphery version 3.2.0

swift-driver version: 1.120.5 Apple Swift version 6.1.2 (swiftlang-6.1.2.1.2 clang-1700.0.13.5)
Target: arm64-apple-macosx15.0

Xcode 16.4
Build version 16F6

[pylapp]

@ileitch I have also a similar issue.

Annotated lighted source code below:

#if canImport(UIKit)
import OUDSComponents // Seen as unused, false positive
import OUDSFoundations // Seen as unused, false positive
import SwiftUI
import UIKit

extension OUDSUIKitBrige {

    @MainActor public static func createButton(icon: Image,
                                               text: String,
                                               appearance: OUDSButton.Appearance = .default,
                                               style: OUDSButton.Style = .default,
                                               action: @escaping () -> Void) -> UIViewController
    {
        OL.warning("Avoid UIKit wrapper and prefer SwiftUI component instead OUDSButton(icon:text:appearance:style:action)")
        let swiftUIButton = OUDSButton(icon: icon,
                                       text: text,
                                       appearance: appearance,
                                       style: style,
                                       action: action)
        return wrap(component: swiftUIButton)
    }
}
#endif

Screenshot of errors

Not the imports are imports of librairies defined in the same Swift Package.

The source code is here.

Envrionment:

periphery version
3.2.0

swift -version
swift-driver version: 1.127.14.1 Apple Swift version 6.2 (swiftlang-6.2.0.19.9 clang-1700.3.19.1)
Target: arm64-apple-macosx15.0

xcodebuild -version
Xcode 26.0.1
Build version 17A400

[pylapp]

@ileitch Another case

   var body: some View {
        #if os(iOS)
        NavigationView {
            listBody
                .navigationBarTitleDisplayMode(.inline)
        }
        .navigationViewStyle(.stack)
        #else
        NavigationView {
            listBody
        }
        .navigationViewStyle(.automatic)
        #endif
    }

    private var listBody: some View { //  warning: Property 'listBody' is unused
        List {
            legalView
            buildView
            linksView
        }
        .oudsNavigationTitle("app_bottomBar_about_label")
    }

 #if os(iOS)
    @ViewBuilder
    private var legalView: some View {
        NavigationLink {
            WebView(from: privacyPolicyUrl)
                .navigationTitle("app_about_privacyPolicy_label")
        } label: {
            Text("app_about_privacyPolicy_label")
        }

        NavigationLink {
            WebView(from: legalInformationUrl)
                .navigationTitle("app_about_legalInformation_label")
        } label: {
            Text("app_about_legalInformation_label")
        }

        NavigationLink {
            AccessibilityStatementPage()
                .navigationTitle("app_about_accessibilityStatement_label")
        } label: {
            Text("app_about_accessibilityStatement_label")
        }
    }

    #elseif os(macOS)
    @ViewBuilder
    private var legalView: some View {  // warning: Property 'legalView' is unused
        NavigationLink {
            WebView(from: privacyPolicyUrl)
        } label: {
            Text("app_about_privacyPolicy_label")
        }

        NavigationLink {
            WebView(from: legalInformationUrl)
        } label: {
            Text("app_about_legalInformation_label")
        }
    }
    #else
    @ViewBuilder
    private var legalView: some View {
        EmptyView()
    }
    #endif