Remove code that supports < Swift 6.0

IntegrationTests/Tests/IntegrationTests/BasicTests.swift

@@ -19,7 +19,6 @@ final class BasicTests: XCTestCase {
 
     func testExamplePackageDealer() throws {
         try XCTSkipIf(isSelfHosted, "These packages don't use the latest runtime library, which doesn't work with self-hosted builds.")
-        try skipUnlessAtLeastSwift6()
 
         try withTemporaryDirectory { tempDir in
             let packagePath = tempDir.appending(component: "dealer")
@@ -94,8 +93,6 @@ final class BasicTests: XCTestCase {
     }
 
     func testSwiftPackageInitExec() throws {
-        try skipUnlessAtLeastSwift6()
-
         try withTemporaryDirectory { tempDir in
             // Create a new package with an executable target.
             let packagePath = tempDir.appending(component: "Project")
@@ -121,8 +118,6 @@ final class BasicTests: XCTestCase {
     }
 
     func testSwiftPackageInitExecTests() throws {
-        try skipUnlessAtLeastSwift6()
-
         try XCTSkip("FIXME: swift-test invocations are timing out in Xcode and self-hosted CI")
 
         try withTemporaryDirectory { tempDir in
@@ -146,8 +141,6 @@ final class BasicTests: XCTestCase {
     }
 
     func testSwiftPackageInitLib() throws {
-        try skipUnlessAtLeastSwift6()
-
         try withTemporaryDirectory { tempDir in
             // Create a new package with an executable target.
             let packagePath = tempDir.appending(component: "Project")
@@ -166,8 +159,6 @@ final class BasicTests: XCTestCase {
     }
 
     func testSwiftPackageLibsTests() throws {
-        try skipUnlessAtLeastSwift6()
-
         try XCTSkip("FIXME: swift-test invocations are timing out in Xcode and self-hosted CI")
 
         try withTemporaryDirectory { tempDir in
@@ -226,8 +217,6 @@ final class BasicTests: XCTestCase {
     }
 
     func testSwiftRun() throws {
-        try skipUnlessAtLeastSwift6()
-
         try withTemporaryDirectory { tempDir in
             let packagePath = tempDir.appending(component: "secho")
             try localFileSystem.createDirectory(packagePath)
@@ -255,8 +244,6 @@ final class BasicTests: XCTestCase {
     }
 
     func testSwiftTest() throws {
-        try skipUnlessAtLeastSwift6()
-
         try XCTSkip("FIXME: swift-test invocations are timing out in Xcode and self-hosted CI")
 
         try withTemporaryDirectory { tempDir in
@@ -378,9 +365,3 @@ private extension Character {
         }
     }
 }
-
-private func skipUnlessAtLeastSwift6() throws {
-    #if compiler(<6.0)
-    try XCTSkipIf(true, "Skipping because test requires at least Swift 6.0")
-    #endif
-}

Sources/Basics/OSSignpost.swift

@@ -11,11 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 #if canImport(os)
-#if compiler(>=6.0)
 import os
-#else
-@preconcurrency import os
-#endif
 
 extension os.OSLog {
     @usableFromInline

Sources/Build/LLBuildCommands.swift

@@ -240,11 +240,6 @@ final class TestEntryPointCommand: CustomLLBuildCommand, TestBuildCommand {
         if buildParameters.triple.isLinux() {
             // FIXME: work around crash on Amazon Linux 2 when main function is async (rdar://128303921)
             needsAsyncMainWorkaround = true
-        } else if buildParameters.triple.isDarwin() {
-#if compiler(<5.10)
-            // FIXME: work around duplicate async_Main symbols (SEE https://github.com/swiftlang/swift/pull/69113)
-            needsAsyncMainWorkaround = true
-#endif
         }
 
         stream.send(

Sources/Commands/PackageCommands/Init.swift

@@ -85,8 +85,4 @@ extension SwiftPackageCommand {
     }
 }
 
-#if compiler(<6.0)
-extension InitPackage.PackageType: ExpressibleByArgument {}
-#else
 extension InitPackage.PackageType: @retroactive ExpressibleByArgument {}
-#endif

Sources/Commands/Utilities/APIDigester.swift

@@ -331,8 +331,4 @@ extension SerializedDiagnostics.SourceLocation {
     }
 }
 
-#if compiler(<6.0)
-extension SerializedDiagnostics.SourceLocation: DiagnosticLocation {}
-#else
 extension SerializedDiagnostics.SourceLocation: @retroactive DiagnosticLocation {}
-#endif

Sources/CoreCommands/Options.swift

@@ -774,16 +774,6 @@ extension URL {
     }
 }
 
-#if compiler(<6.0)
-extension BuildConfiguration: ExpressibleByArgument, CaseIterable {}
-extension AbsolutePath: ExpressibleByArgument {}
-extension WorkspaceConfiguration.CheckingMode: ExpressibleByArgument {}
-extension Sanitizer: ExpressibleByArgument {}
-extension BuildSystemProvider.Kind: ExpressibleByArgument, CaseIterable {}
-extension Version: ExpressibleByArgument {}
-extension PackageIdentity: ExpressibleByArgument {}
-extension URL: ExpressibleByArgument {}
-#else
 extension BuildConfiguration: @retroactive ExpressibleByArgument, CaseIterable {}
 extension AbsolutePath: @retroactive ExpressibleByArgument {}
 extension WorkspaceConfiguration.CheckingMode: @retroactive ExpressibleByArgument {}
@@ -792,4 +782,3 @@ extension BuildSystemProvider.Kind: @retroactive ExpressibleByArgument, CaseIter
 extension Version: @retroactive ExpressibleByArgument {}
 extension PackageIdentity: @retroactive ExpressibleByArgument {}
 extension URL: @retroactive ExpressibleByArgument {}
-#endif

Sources/PackageRegistryCommand/PackageRegistryCommand+Publish.swift

@@ -247,11 +247,7 @@ extension SignatureFormat {
     }
 }
 
-#if compiler(<6.0)
-extension SignatureFormat: ExpressibleByArgument {}
-#else
 extension SignatureFormat: @retroactive ExpressibleByArgument {}
-#endif
 
 enum MetadataLocation {
     case sourceTree(AbsolutePath)

Sources/Workspace/Diagnostics.swift

@@ -255,8 +255,4 @@ extension FileSystemError {
     }
 }
 
-#if compiler(<6.0)
-extension FileSystemError: CustomStringConvertible {}
-#else
 extension FileSystemError: @retroactive CustomStringConvertible {}
-#endif

Sources/Workspace/Workspace.swift

@@ -1519,11 +1519,7 @@ private func warnToStderr(_ message: String) {
 }
 
 // used for manifest validation
-#if compiler(<6.0)
-extension RepositoryManager: ManifestSourceControlValidator {}
-#else
 extension RepositoryManager: @retroactive ManifestSourceControlValidator {}
-#endif
 
 extension ContainerUpdateStrategy {
     var repositoryUpdateStrategy: RepositoryUpdateStrategy {

Sources/_InternalTestSupport/misc.swift

@@ -515,16 +515,6 @@ extension InitPackage {
     }
 }
 
-#if compiler(<6.0)
-extension RelativePath: ExpressibleByStringLiteral {}
-extension RelativePath: ExpressibleByStringInterpolation {}
-extension URL: ExpressibleByStringLiteral {}
-extension URL: ExpressibleByStringInterpolation {}
-extension PackageIdentity: ExpressibleByStringLiteral {}
-extension PackageIdentity: ExpressibleByStringInterpolation {}
-extension AbsolutePath: ExpressibleByStringLiteral {}
-extension AbsolutePath: ExpressibleByStringInterpolation {}
-#else
 extension RelativePath: @retroactive ExpressibleByStringLiteral {}
 extension RelativePath: @retroactive ExpressibleByStringInterpolation {}
 extension URL: @retroactive ExpressibleByStringLiteral {}
@@ -533,7 +523,6 @@ extension PackageIdentity: @retroactive ExpressibleByStringLiteral {}
 extension PackageIdentity: @retroactive ExpressibleByStringInterpolation {}
 extension AbsolutePath: @retroactive ExpressibleByStringLiteral {}
 extension AbsolutePath: @retroactive ExpressibleByStringInterpolation {}
-#endif
 
 public func getNumberOfMatches(of match: String, in value: String) -> Int {
     guard match.count != 0 else { return 0 }

Sources/swift-bootstrap/main.swift

@@ -495,15 +495,9 @@ extension BuildConfiguration {
     }
 }
 
-#if compiler(<6.0)
-extension AbsolutePath: ExpressibleByArgument {}
-extension BuildConfiguration: ExpressibleByArgument, CaseIterable {}
-extension BuildSystemProvider.Kind: ExpressibleByArgument, CaseIterable {}
-#else
 extension AbsolutePath: @retroactive ExpressibleByArgument {}
 extension BuildConfiguration: @retroactive ExpressibleByArgument, CaseIterable {}
 extension BuildSystemProvider.Kind: @retroactive ExpressibleByArgument, CaseIterable {}
-#endif
 
 public func topologicalSort<T: Hashable>(
     _ nodes: [T], successors: (T) async throws -> [T]

Sources/swiftpm-testing-helper/Entrypoint.swift

@@ -20,11 +20,7 @@ struct Entrypoint {
             let bundlePath = args[2]
             guard let image = dlopen(bundlePath, RTLD_LAZY | RTLD_FIRST) else {
                 let errorMessage: String = dlerror().flatMap {
-                    #if compiler(>=6)
                     String(validatingCString: $0)
-                    #else
-                    String(validatingUTF8: $0)
-                    #endif
                 } ?? "An unknown error occurred."
                 fatalError("Failed to open test bundle at path \(bundlePath): \(errorMessage)")
             }

Tests/BuildTests/BuildSystemDelegateTests.swift

@@ -18,7 +18,6 @@ import var TSCBasic.localFileSystem
 
 final class BuildSystemDelegateTests: XCTestCase {
     func testDoNotFilterLinkerDiagnostics() async throws {
-        try UserToolchain.default.skipUnlessAtLeastSwift6()
         try XCTSkipIf(!UserToolchain.default.supportsSDKDependentTests(), "skipping because test environment doesn't support this test")
         try await fixture(name: "Miscellaneous/DoNotFilterLinkerDiagnostics") { fixturePath in
             #if !os(macOS)

Tests/CommandsTests/APIDiffTests.swift

@@ -55,11 +55,6 @@ final class APIDiffTests: CommandsTestCase {
       guard (try? UserToolchain.default.getSwiftAPIDigester()) != nil else {
         throw XCTSkip("swift-api-digester unavailable")
       }
-      // The tests rely on swift-api-digester post-5.5 version and are certain
-      // to work with Swift compiler v6.0 and later.
-      #if compiler(<6.0)
-        throw XCTSkip("Skipping because test requires at least Swift compiler v6.0")
-      #endif
     }
 
     func testInvokeAPIDiffDigester() async throws {

Tests/CommandsTests/BuildCommandTests.swift

@@ -721,13 +721,7 @@ final class BuildCommandTests: CommandsTestCase {
     }
 
     func testFatalErrorDisplayedCorrectNumberOfTimesWhenSingleXCTestHasFatalErrorInBuildCompilation() async throws {
-        // Test for GitHub Issue #6605
-        // GIVEN we have a Swift Package that has a fatalError building the tests
-        #if compiler(>=6)
         let expected = 0
-        #else
-        let expected = 1
-        #endif
         try await fixture(name: "Miscellaneous/Errors/FatalErrorInSingleXCTest/TypeLibrary") { fixturePath in
             // WHEN swift-build --build-tests is executed"
             await XCTAssertAsyncThrowsError(try await self.execute(["--build-tests"], packagePath: fixturePath)) { error in

Tests/CommandsTests/TestCommandTests.swift

@@ -255,16 +255,12 @@ final class TestCommandTests: CommandsTestCase {
     }
 
     func testSwiftTestXMLOutputVerifySingleTestFailureMessageWithFlagEnabledSwiftTesting() async throws {
-        #if compiler(<6)
-        _ = XCTSkip("Swift Testing is not available by default in this Swift compiler version")
-        #else
         try await self._testSwiftTestXMLOutputFailureMessage(
             fixtureName: "Miscellaneous/TestSingleFailureSwiftTesting",
             testRunner: .SwiftTesting,
             enableExperimentalFlag: true,
             matchesPattern: [.contains("Purposely failing &amp; validating XML espace &quot;'&lt;&gt;")]
         )
-        #endif
     }
     func testSwiftTestXMLOutputVerifySingleTestFailureMessageWithFlagDisabledXCTest() async throws {
         try await self._testSwiftTestXMLOutputFailureMessage(
@@ -276,16 +272,12 @@ final class TestCommandTests: CommandsTestCase {
     }
 
     func testSwiftTestXMLOutputVerifySingleTestFailureMessageWithFlagDisabledSwiftTesting() async throws {
-        #if compiler(<6)
-        _ = XCTSkip("Swift Testing is not available by default in this Swift compiler version")
-        #else
         try await self._testSwiftTestXMLOutputFailureMessage(
             fixtureName: "Miscellaneous/TestSingleFailureSwiftTesting",
             testRunner: .SwiftTesting,
             enableExperimentalFlag: false,
             matchesPattern: [.contains("Purposely failing &amp; validating XML espace &quot;'&lt;&gt;")]
         )
-        #endif
     }
 
     func testSwiftTestXMLOutputVerifyMultipleTestFailureMessageWithFlagEnabledXCTest() async throws {
@@ -309,9 +301,6 @@ final class TestCommandTests: CommandsTestCase {
     }
 
     func testSwiftTestXMLOutputVerifyMultipleTestFailureMessageWithFlagEnabledSwiftTesting() async throws {
-        #if compiler(<6)
-        _ = XCTSkip("Swift Testing is not available by default in this Swift compiler version")
-        #else
         try await self._testSwiftTestXMLOutputFailureMessage(
             fixtureName: "Miscellaneous/TestMultipleFailureSwiftTesting",
             testRunner: .SwiftTesting,
@@ -329,7 +318,6 @@ final class TestCommandTests: CommandsTestCase {
                 .contains("ST Test failure 10")
             ]
         )
-        #endif
     }
 
     func testSwiftTestXMLOutputVerifyMultipleTestFailureMessageWithFlagDisabledXCTest() async throws {
@@ -353,9 +341,6 @@ final class TestCommandTests: CommandsTestCase {
     }
 
     func testSwiftTestXMLOutputVerifyMultipleTestFailureMessageWithFlagDisabledSwiftTesting() async throws {
-        #if compiler(<6)
-        _ = XCTSkip("Swift Testing is not available by default in this Swift compiler version")
-        #else
         try await self._testSwiftTestXMLOutputFailureMessage(
             fixtureName: "Miscellaneous/TestMultipleFailureSwiftTesting",
             testRunner: .SwiftTesting,
@@ -373,7 +358,6 @@ final class TestCommandTests: CommandsTestCase {
                 .contains("ST Test failure 10")
             ]
         )
-        #endif
     }
 
     func testSwiftTestFilter() async throws {
@@ -585,11 +569,7 @@ final class TestCommandTests: CommandsTestCase {
     func testFatalErrorDisplayedCorrectNumberOfTimesWhenSingleXCTestHasFatalErrorInBuildCompilation() async throws {
         // Test for GitHub Issue #6605
         // GIVEN we have a Swift Package that has a fatalError building the tests
-        #if compiler(>=6)
         let expected = 1
-        #else
-        let expected = 2
-        #endif
         try await fixture(name: "Miscellaneous/Errors/FatalErrorInSingleXCTest/TypeLibrary") { fixturePath in
             // WHEN swift-test is executed
             await XCTAssertAsyncThrowsError(try await self.execute([], packagePath: fixturePath)) { error in

Tests/FunctionalTests/MiscellaneousTests.swift

@@ -426,9 +426,6 @@ final class MiscellaneousTestCase: XCTestCase {
 
     @available(macOS 15, *)
     func testTestsCanLinkAgainstAsyncExecutable() async throws {
-        #if compiler(<5.10)
-        try XCTSkipIf(true, "skipping because host compiler doesn't have a fix for symbol conflicts yet")
-        #endif
         try await fixture(name: "Miscellaneous/TestableAsyncExe") { fixturePath in
             let (stdout, stderr) = try await executeSwiftTest(fixturePath)
             // in "swift test" build output goes to stderr