Adopt upcoming Swift language feature MemberImportVisibility (#803)

tshortli · web-flow · commit 4f680a7e9c70 · 2025-09-08T11:05:36.000-07:00
* Adopt upcoming Swift language feature MemberImportVisibility.

Enable the language feature flag for SE-0444. This instructs the compiler to
be stricter about requiring import declarations in order to access member
declarations.

* Replace `#if swift(&gt;=6.0)` guards with `#if compiler(&gt;=6.0)`.

All uses of `internal import` were previously guarded with `#if swift(&gt;=6.0)`,
presumably to handle differences in compiler support for `internal import`.
However, `#if swift(&gt;=)` is not the correct directive to use for this purpose,
as it primarily tests the language mode that is enabled. These existing
conditionals never evaluated true when building this package since it is not
configured to build with Swift 6 enabled. Instead, use `#if compiler(&gt;=6.0)`
which correctly predicates the imports on only the compiler version.
diff --git a/Package@swift-5.8.swift b/Package@swift-5.8.swift
@@ -138,3 +138,17 @@ package.targets.append(contentsOf: [
     path: "Tools/changelog-authors"),
 ])
 #endif
+
+for target in package.targets {
+  switch target.type {
+  case .regular, .test, .executable:
+    var settings = target.swiftSettings ?? []
+    // https://github.com/swiftlang/swift-evolution/blob/main/proposals/0444-member-import-visibility.md
+    settings.append(.enableUpcomingFeature("MemberImportVisibility"))
+    target.swiftSettings = settings
+  case .macro, .plugin, .system, .binary:
+    break  // not applicable
+  @unknown default:
+    break  // we don't know what to do here, do nothing
+  }
+}
diff --git a/Sources/ArgumentParser/Completions/BashCompletionsGenerator.swift b/Sources/ArgumentParser/Completions/BashCompletionsGenerator.swift
@@ -9,7 +9,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if swift(>=6.0)
+#if compiler(>=6.0)
 internal import ArgumentParserToolInfo
 #else
 import ArgumentParserToolInfo
diff --git a/Sources/ArgumentParser/Completions/CompletionsGenerator.swift b/Sources/ArgumentParser/Completions/CompletionsGenerator.swift
@@ -9,10 +9,12 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if swift(>=6.0)
+#if compiler(>=6.0)
 internal import ArgumentParserToolInfo
+internal import Foundation
 #else
 import ArgumentParserToolInfo
+import Foundation
 #endif
 
 /// A shell for which the parser can generate a completion script.
diff --git a/Sources/ArgumentParser/Completions/FishCompletionsGenerator.swift b/Sources/ArgumentParser/Completions/FishCompletionsGenerator.swift
@@ -9,10 +9,12 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if swift(>=6.0)
+#if compiler(>=6.0)
 internal import ArgumentParserToolInfo
+internal import Foundation
 #else
 import ArgumentParserToolInfo
+import Foundation
 #endif
 
 extension ToolInfoV0 {
diff --git a/Sources/ArgumentParser/Completions/ZshCompletionsGenerator.swift b/Sources/ArgumentParser/Completions/ZshCompletionsGenerator.swift
@@ -9,10 +9,12 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if swift(>=6.0)
+#if compiler(>=6.0)
 internal import ArgumentParserToolInfo
+internal import Foundation
 #else
 import ArgumentParserToolInfo
+import Foundation
 #endif
 
 extension ToolInfoV0 {
diff --git a/Sources/ArgumentParser/Parsable Types/ParsableArguments.swift b/Sources/ArgumentParser/Parsable Types/ParsableArguments.swift
@@ -9,6 +9,12 @@
 //
 //===----------------------------------------------------------------------===//
 
+#if compiler(>=6.0)
+internal import Foundation
+#else
+import Foundation
+#endif
+
 /// A type that can be parsed from a program's command-line arguments.
 ///
 /// When you implement a `ParsableArguments` type, all properties must be declared with
diff --git a/Sources/ArgumentParser/Parsing/CommandParser.swift b/Sources/ArgumentParser/Parsing/CommandParser.swift
@@ -9,7 +9,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if swift(>=6.0)
+#if compiler(>=6.0)
 #if canImport(Dispatch)
 @preconcurrency private import class Dispatch.DispatchSemaphore
 #endif
diff --git a/Sources/ArgumentParser/Usage/DumpHelpGenerator.swift b/Sources/ArgumentParser/Usage/DumpHelpGenerator.swift
@@ -9,7 +9,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if swift(>=6.0)
+#if compiler(>=6.0)
 internal import ArgumentParserToolInfo
 internal import class Foundation.JSONEncoder
 #else
diff --git a/Sources/ArgumentParser/Usage/MessageInfo.swift b/Sources/ArgumentParser/Usage/MessageInfo.swift
@@ -9,7 +9,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if swift(>=6.0)
+#if compiler(>=6.0)
 internal import protocol Foundation.LocalizedError
 internal import class Foundation.NSError
 #else
diff --git a/Sources/ArgumentParser/Usage/UsageGenerator.swift b/Sources/ArgumentParser/Usage/UsageGenerator.swift
@@ -9,7 +9,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if swift(>=6.0)
+#if compiler(>=6.0)
 internal import protocol Foundation.LocalizedError
 #else
 import protocol Foundation.LocalizedError
diff --git a/Sources/ArgumentParser/Utilities/Mutex.swift b/Sources/ArgumentParser/Utilities/Mutex.swift
@@ -9,7 +9,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if swift(>=6.0)
+#if compiler(>=6.0)
 internal import Foundation
 #else
 import Foundation
diff --git a/Sources/ArgumentParserTestHelpers/StringHelpers.swift b/Sources/ArgumentParserTestHelpers/StringHelpers.swift
@@ -9,6 +9,12 @@
 //
 //===----------------------------------------------------------------------===//
 
+#if compiler(>=6.0)
+internal import Foundation
+#else
+import Foundation
+#endif
+
 extension Substring {
   func trimmed() -> Substring {
     guard let i = lastIndex(where: { $0 != " " }) else {
diff --git a/Tests/ArgumentParserExampleTests/MathExampleTests.swift b/Tests/ArgumentParserExampleTests/MathExampleTests.swift
@@ -9,15 +9,10 @@
 //
 //===----------------------------------------------------------------------===//
 
-import ArgumentParser
 import ArgumentParserTestHelpers
 import XCTest
 
-#if swift(>=6.0)
-@testable internal import struct ArgumentParser.CompletionShell
-#else
-@testable import struct ArgumentParser.CompletionShell
-#endif
+@testable import ArgumentParser
 
 final class MathExampleTests: XCTestCase {
   override func setUp() {
diff --git a/Tests/ArgumentParserExampleTests/RepeatExampleTests.swift b/Tests/ArgumentParserExampleTests/RepeatExampleTests.swift
@@ -9,6 +9,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+import ArgumentParser
 import ArgumentParserTestHelpers
 import XCTest
 
diff --git a/Tests/ArgumentParserExampleTests/RollDiceExampleTests.swift b/Tests/ArgumentParserExampleTests/RollDiceExampleTests.swift
@@ -9,6 +9,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+import ArgumentParser
 import ArgumentParserTestHelpers
 import XCTest
 
