Remove SystemPackage as an explicit dependency

If the package is available (e.g. other dependant on parent project), we’ll use it, otherwise we’ll use a dummy Errno implementation to have things compile.

Author: Frizlab

Package.swift

@@ -12,46 +12,31 @@ let package = Package(
 		.macOS(.v11),
 		.tvOS(.v14),
 		.iOS(.v14),
-		.watchOS(.v7)
+		.watchOS(.v7),
 	],
 	products: [
 		.library(name: "SignalHandling", targets: ["SignalHandling"])
 	],
-	dependencies: {
-		var res = [Package.Dependency]()
-		res.append(.package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.0.0"))
-		res.append(.package(url: "https://github.com/apple/swift-log.git",             from: "1.4.2"))
-		res.append(.package(url: "https://github.com/xcode-actions/clt-logger.git",    from: "0.4.0"))
-#if !canImport(System)
-		res.append(.package(url: "https://github.com/apple/swift-system.git",          from: "1.0.0"))
-#endif
-		return res
-	}(),
+	dependencies: [
+		.package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.0.0"),
+		.package(url: "https://github.com/apple/swift-log.git",             from: "1.4.2"),
+		.package(url: "https://github.com/xcode-actions/clt-logger.git",    from: "0.4.0"),
+	],
 	targets: [
-		.target(name: "SignalHandling", dependencies: {
-			var res = [Target.Dependency]()
-			res.append(.product(name: "Logging", package: "swift-log"))
-#if !canImport(System)
-			res.append(.product(name: "SystemPackage", package: "swift-system"))
-#endif
-			return res
-		}(), swiftSettings: noSwiftSettings),
+		.target(name: "SignalHandling", dependencies: [
+			.product(name: "Logging", package: "swift-log"),
+		], swiftSettings: noSwiftSettings),
 
 		.target(name: "signal-handling-tests-helper", dependencies: [
 			.product(name: "ArgumentParser", package: "swift-argument-parser"),
 			.product(name: "CLTLogger",      package: "clt-logger"),
 			.product(name: "Logging",        package: "swift-log"),
-			.target(name: "SignalHandling")
+			.target(name: "SignalHandling"),
 		], swiftSettings: noSwiftSettings),
-		.testTarget(name: "SignalHandlingTests", dependencies: {
-			var res = [Target.Dependency]()
-			res.append(.target(name: "signal-handling-tests-helper"))
-			res.append(.product(name: "CLTLogger",     package: "clt-logger"))
-			res.append(.product(name: "Logging",       package: "swift-log"))
-#if !canImport(System)
-			res.append(.product(name: "SystemPackage", package: "swift-system"))
-#endif
-			return res
-		}(), swiftSettings: noSwiftSettings)
+		.testTarget(name: "SignalHandlingTests", dependencies: [
+			.target(name: "signal-handling-tests-helper"),
+			.product(name: "CLTLogger",     package: "clt-logger"),
+			.product(name: "Logging",       package: "swift-log"),
+		], swiftSettings: noSwiftSettings)
 	]
 )

Sources/SignalHandling/CStructsInSwift/Sigaction.swift

@@ -1,8 +1,8 @@
 import Foundation
-#if canImport(System)
-import System
-#else
+#if canImport(SystemPackage)
 import SystemPackage
+#elseif canImport(System)
+import System
 #endif
 
 

Sources/SignalHandling/DelayedSigaction/SigactionDelayer_Block.swift

@@ -1,8 +1,8 @@
 import Foundation
-#if canImport(System)
-import System
-#else
+#if canImport(SystemPackage)
 import SystemPackage
+#elseif canImport(System)
+import System
 #endif
 
 

Sources/SignalHandling/DelayedSigaction/SigactionDelayer_Unsig.swift

@@ -1,8 +1,8 @@
 import Foundation
-#if canImport(System)
-import System
-#else
+#if canImport(SystemPackage)
 import SystemPackage
+#elseif canImport(System)
+import System
 #endif
 
 import Logging

Sources/SignalHandling/ErrnoWithoutSystem.swift

@@ -0,0 +1,11 @@
+#if !canImport(SystemPackage) && !canImport(System)
+import Foundation
+
+public struct Errno : RawRepresentable, Error, Hashable, Codable {
+	public let rawValue: CInt
+	public init(rawValue: CInt) {
+		self.rawValue = rawValue
+	}
+}
+
+#endif

Sources/SignalHandling/SignalHandlingError.swift

@@ -1,8 +1,8 @@
 import Foundation
-#if canImport(System)
-import System
-#else
+#if canImport(SystemPackage)
 import SystemPackage
+#elseif canImport(System)
+import System
 #endif
 
 

Sources/signal-handling-tests-helper/DelaySignalBlock.swift

@@ -1,9 +1,4 @@
 import Foundation
-#if canImport(System)
-import System
-#else
-import SystemPackage
-#endif
 
 import ArgumentParser
 import CLTLogger
@@ -42,5 +37,5 @@ struct DelaySignalBlock : ParsableCommand {
 
 /* Using print does not work in Terminal probably due to buffering. */
 private func writeToStdout(_ str: String) {
-	try! FileDescriptor.standardOutput.writeAll(Data((str + "\n").utf8))
+	try! FileHandle.standardOutput.write(contentsOf: Data((str + "\n").utf8))
 }

Sources/signal-handling-tests-helper/DelaySignalUnsigaction.swift

@@ -1,9 +1,4 @@
 import Foundation
-#if canImport(System)
-import System
-#else
-import SystemPackage
-#endif
 
 import ArgumentParser
 import CLTLogger
@@ -40,5 +35,5 @@ struct DelaySignalUnsigaction : ParsableCommand {
 
 /* Using print does not work in Terminal probably due to buffering. */
 private func writeToStdout(_ str: String) {
-	try! FileDescriptor.standardOutput.writeAll(Data((str + "\n").utf8))
+	try! FileHandle.standardOutput.write(contentsOf: Data((str + "\n").utf8))
 }