Rename "CC Destination" to "Swift SDK" (#6424)

"Cross-compilation destination" is a very verbose name. "Swift SDK" (note that this is distinct from just plain "SDK" used in other contexts) is a nicer alternative. Not all of the types and functions were renamed yet, especially `Destination`, which has been present in the codebase for long time. Renaming that type will be potentially source-breaking for libSwiftPM clients. This change is focused on updating user-visible strings and renaming types and functions that were  added only recently. CLI subcommands were renamed accordingly.

Author: MaxDesiatov

Package.swift

@@ -409,8 +409,8 @@ let package = Package(
         ),
 
         .target(
-            /** Interacts with cross-compilation destinations */
-            name: "CrossCompilationDestinationsTool",
+            /** Interacts with Swift SDKs used for cross-compilation */
+            name: "SwiftSDKTool",
             dependencies: [
                 .product(name: "ArgumentParser", package: "swift-argument-parser"),
                 "Basics",
@@ -480,9 +480,9 @@ let package = Package(
             exclude: ["CMakeLists.txt"]
         ),
         .executableTarget(
-            /** Interacts with cross-compilation destinations */
-            name: "swift-experimental-destination",
-            dependencies: ["Commands", "CrossCompilationDestinationsTool"],
+            /** Interacts with Swift SDKs used for cross-compilation */
+            name: "swift-experimental-sdk",
+            dependencies: ["Commands", "SwiftSDKTool"],
             exclude: ["CMakeLists.txt"]
         ),
         .executableTarget(
@@ -508,7 +508,7 @@ let package = Package(
             dependencies: [
                 "Basics",
                 "Commands",
-                "CrossCompilationDestinationsTool",
+                "SwiftSDKTool",
                 "PackageCollectionsTool",
                 "PackageRegistryTool"
             ],

Sources/Basics/FileSystem/FileSystem+Extensions.swift

@@ -224,65 +224,63 @@ extension FileSystem {
     }
 }
 
-// MARK: - cross-compilation destinations
+// MARK: - Swift SDKs
 
-private let crossCompilationDestinationsDirectoryName = "destinations"
+private let swiftSDKsDirectoryName = "swift-sdks"
 
 extension FileSystem {
-    /// SwiftPM cross-compilation destinations directory (if exists)
-    public var swiftPMCrossCompilationDestinationsDirectory: AbsolutePath {
+    /// Path to Swift SDKs directory (if exists)
+    public var swiftSDKsDirectory: AbsolutePath {
         get throws {
             if let path = try idiomaticSwiftPMDirectory {
-                return path.appending(component: crossCompilationDestinationsDirectoryName)
+                return path.appending(component: swiftSDKsDirectoryName)
             } else {
-                return try dotSwiftPMCrossCompilationDestinationsDirectory
+                return try dotSwiftPMSwiftSDKsDirectory
             }
         }
     }
 
-    fileprivate var dotSwiftPMCrossCompilationDestinationsDirectory: AbsolutePath {
+    fileprivate var dotSwiftPMSwiftSDKsDirectory: AbsolutePath {
         get throws {
-            return try dotSwiftPM.appending(component: crossCompilationDestinationsDirectoryName)
+            return try dotSwiftPM.appending(component: swiftSDKsDirectoryName)
         }
     }
 
-    public func getSharedCrossCompilationDestinationsDirectory(
-        explicitDirectory: AbsolutePath?
-    ) throws -> AbsolutePath? {
-        if let explicitDestinationsDirectory = explicitDirectory {
+    public func getSharedSwiftSDKsDirectory(explicitDirectory: AbsolutePath?) throws -> AbsolutePath? {
+        if let explicitDirectory {
             // Create the explicit SDKs path if necessary
-            if !exists(explicitDestinationsDirectory) {
-                try createDirectory(explicitDestinationsDirectory, recursive: true)
+            if !exists(explicitDirectory) {
+                try createDirectory(explicitDirectory, recursive: true)
             }
-            return explicitDestinationsDirectory
+            return explicitDirectory
         } else {
-            return try swiftPMCrossCompilationDestinationsDirectory
+            return try swiftSDKsDirectory
         }
     }
 
-    public func getOrCreateSwiftPMCrossCompilationDestinationsDirectory() throws -> AbsolutePath {
-        let idiomaticDestinationsDirectory = try swiftPMCrossCompilationDestinationsDirectory
+    public func getOrCreateSwiftPMSwiftSDKsDirectory() throws -> AbsolutePath {
+        let idiomaticSwiftSDKDirectory = try swiftSDKsDirectory
 
         // Create idiomatic if necessary
-        if !exists(idiomaticDestinationsDirectory) {
-            try createDirectory(idiomaticDestinationsDirectory, recursive: true)
+        if !exists(idiomaticSwiftSDKDirectory) {
+            try createDirectory(idiomaticSwiftSDKDirectory, recursive: true)
         }
         // Create ~/.swiftpm if necessary
         if !exists(try dotSwiftPM) {
             try createDirectory(dotSwiftPM, recursive: true)
         }
-        // Create ~/.swiftpm/destinations symlink if necessary
+        // Create ~/.swiftpm/swift-sdks symlink if necessary
         // locking ~/.swiftpm to protect from concurrent access
         try withLock(on: dotSwiftPM, type: .exclusive) {
-            if !exists(try dotSwiftPMCrossCompilationDestinationsDirectory, followSymlink: false) {
+            if !exists(try dotSwiftPMSwiftSDKsDirectory, followSymlink: false) {
                 try createSymbolicLink(
-                    dotSwiftPMCrossCompilationDestinationsDirectory,
-                    pointingAt: idiomaticDestinationsDirectory,
+                    dotSwiftPMSwiftSDKsDirectory,
+                    pointingAt: idiomaticSwiftSDKDirectory,
                     relative: false
                 )
             }
         }
-        return idiomaticDestinationsDirectory
+        return idiomaticSwiftSDKDirectory
     }
 }
 

Sources/CMakeLists.txt

@@ -12,7 +12,7 @@ add_subdirectory(Build)
 add_subdirectory(Commands)
 add_subdirectory(CompilerPluginSupport)
 add_subdirectory(CoreCommands)
-add_subdirectory(CrossCompilationDestinationsTool)
+add_subdirectory(SwiftSDKTool)
 add_subdirectory(DriverSupport)
 add_subdirectory(LLBuildManifest)
 add_subdirectory(PackageDescription)
@@ -28,7 +28,7 @@ add_subdirectory(SPMLLBuild)
 add_subdirectory(SourceControl)
 add_subdirectory(swift-bootstrap)
 add_subdirectory(swift-build)
-add_subdirectory(swift-experimental-destination)
+add_subdirectory(swift-experimental-sdk)
 add_subdirectory(swift-package)
 add_subdirectory(swift-run)
 add_subdirectory(swift-test)

Sources/CoreCommands/Options.swift

@@ -107,8 +107,9 @@ public struct LocationOptions: ParsableArguments {
     @Option(name: .customLong("destination"), help: .hidden, completion: .directory)
     public var customCompileDestination: AbsolutePath?
 
-    @Option(name: .customLong("experimental-destinations-path"), help: .hidden, completion: .directory)
-    public var crossCompilationDestinationsDirectory: AbsolutePath?
+    /// Path to the directory containing installed Swift SDKs.
+    @Option(name: .customLong("experimental-swift-sdks-path"), help: .hidden, completion: .directory)
+    public var swiftSDKsDirectory: AbsolutePath?
 
     @Option(
         name: .customLong("pkg-config-path"),
@@ -398,9 +399,9 @@ public struct BuildOptions: ParsableArguments {
     )
     public var architectures: [String] = []
 
-    /// Path to the compilation destination describing JSON file.
-    @Option(name: .customLong("experimental-destination-selector"), help: .hidden)
-    public var crossCompilationDestinationSelector: String?
+    /// Filter for selecting a specific Swift SDK to build with.
+    @Option(name: .customLong("experimental-swift-sdk"), help: .hidden)
+    public var swiftSDKSelector: String?
 
     /// Which compile-time sanitizers should be enabled.
     @Option(

Sources/CoreCommands/SwiftTool.swift

@@ -209,7 +209,7 @@ public final class SwiftTool {
     public let sharedConfigurationDirectory: AbsolutePath?
 
     /// Path to the cross-compilation destinations directory.
-    public let sharedCrossCompilationDestinationsDirectory: AbsolutePath?
+    public let sharedSwiftSDKsDirectory: AbsolutePath?
 
     /// Cancellator to handle cancellation of outstanding work when handling SIGINT
     public let cancellator: Cancellator
@@ -336,10 +336,9 @@ public final class SwiftTool {
             fileSystem: fileSystem
         )
         self.sharedCacheDirectory = try getSharedCacheDirectory(options: options, fileSystem: fileSystem)
-        self.sharedCrossCompilationDestinationsDirectory = try fileSystem
-            .getSharedCrossCompilationDestinationsDirectory(
-                explicitDirectory: options.locations.crossCompilationDestinationsDirectory
-            )
+        self.sharedSwiftSDKsDirectory = try fileSystem.getSharedSwiftSDKsDirectory(
+            explicitDirectory: options.locations.swiftSDKsDirectory
+        )
 
         // set global process logging handler
         Process.loggingHandler = { self.observabilityScope.emit(debug: $0) }
@@ -744,11 +743,11 @@ public final class SwiftTool {
                       let targetDestination = Destination.defaultDestination(for: triple, host: hostDestination)
             {
                 destination = targetDestination
-            } else if let destinationSelector = options.build.crossCompilationDestinationSelector {
-                destination = try DestinationBundle.selectDestination(
-                    fromBundlesAt: sharedCrossCompilationDestinationsDirectory,
+            } else if let swiftSDKSelector = options.build.swiftSDKSelector {
+                destination = try SwiftSDKBundle.selectBundle(
+                    fromBundlesAt: sharedSwiftSDKsDirectory,
                     fileSystem: fileSystem,
-                    matching: destinationSelector,
+                    matching: swiftSDKSelector,
                     hostTriple: hostTriple,
                     observabilityScope: observabilityScope
                 )

Sources/PackageModel/ArtifactsArchiveMetadata.swift

@@ -38,11 +38,14 @@ public struct ArtifactsArchiveMetadata: Equatable {
     }
 
     // In the future we are likely to extend the ArtifactsArchive file format to carry other types of artifacts beyond
-    // executables and cross-compilation destinations. Additional fields may be required to support these new artifact
+    // executables and Swift SDKs. Additional fields may be required to support these new artifact
     // types e.g. headers path for libraries. This can also support resource-only artifacts as well. For example,
     // 3d models along with associated textures, or fonts, etc.
     public enum ArtifactType: String, RawRepresentable, Decodable {
         case executable
+        case swiftSDK
+
+        // Can't be marked as formally deprecated as we still need to use this value for warning users.
         case crossCompilationDestination
     }
 

Sources/PackageModel/CMakeLists.txt

@@ -13,8 +13,6 @@ add_library(PackageModel
   BuildFlags.swift
   BuildSettings.swift
   Destination.swift
-  DestinationConfigurationStore.swift
-  DestinationBundle.swift
   Diagnostics.swift
   IdentityResolver.swift
   Manifest/Manifest.swift
@@ -44,6 +42,8 @@ add_library(PackageModel
   Sources.swift
   SupportedLanguageExtension.swift
   SwiftLanguageVersion.swift
+  SwiftSDKConfigurationStore.swift
+  SwiftSDKBundle.swift
   Target.swift
   Toolchain.swift
   ToolchainConfiguration.swift

Sources/PackageModel/Destination.swift

@@ -63,33 +63,33 @@ extension DestinationError: CustomStringConvertible {
             return problem
         case .invalidBundleName(let name):
             return """
-            invalid bundle name `\(name)`, unpacked destination bundles are expected to have `.artifactbundle` extension
+            invalid bundle name `\(name)`, unpacked Swift SDK bundles are expected to have `.artifactbundle` extension
             """
         case .noDestinationsDecoded(let path):
-            return "no valid destinations were decoded from a destination file at path `\(path)`"
+            return "no valid Swift SDKs were decoded from a destination file at path `\(path)`"
         case .pathIsNotDirectory(let path):
             return "path expected to be a directory is not a directory or doesn't exist: `\(path)`"
         case .unserializableDestination:
             return """
-            destination couldn't be serialized with the latest serialization schema, potentially because it \
-            was deserialized from an earlier incompatible schema version or initialized manually with missing \
+            Swift SDK configuration couldn't be serialized with the latest serialization schema, potentially because \
+            it was deserialized from an earlier incompatible schema version or initialized manually with missing \
             properties required for initialization
             """
         case .destinationNotFound(let artifactID, let buildTimeTriple, let runTimeTriple):
             return """
-            destination with ID `\(artifactID)`, build-time triple \(buildTimeTriple), and run-time triple \
+            Swift SDK with ID `\(artifactID)`, build-time triple \(buildTimeTriple), and run-time triple \
             \(runTimeTriple) is not currently installed.
             """
         case .destinationBundleAlreadyInstalled(let bundleName):
             return """
-            destination artifact bundle with name `\(bundleName)` is already installed. Can't install a new bundle \
+            Swift SDK bundle with name `\(bundleName)` is already installed. Can't install a new bundle \
             with the same name.
             """
         case .destinationArtifactAlreadyInstalled(let installedBundleName, let newBundleName, let artifactID):
             return """
-            A destination with artifact ID `\(artifactID)` is already included in an installed bundle with name \
+            A Swift SDK with artifact ID `\(artifactID)` is already included in an installed bundle with name \
             `\(installedBundleName)`. Can't install a new bundle `\(newBundleName)` with this artifact, artifact IDs \
-            are expected to be unique across all installed bundles.
+            are expected to be unique across all installed Swift SDK bundles.
             """
         }
     }