Improve handling of Span back-deployment library bundling

A couple of related fixes:
* Use 26.0 as the fallback version number when SDKSettings doesn't include SwiftSpanMinimumDeploymentTarget
* Update tests to expect `--back-deploy-swift-span` and check when it shouldn't be there

Author: DougGregor

Sources/SWBCore/PlatformRegistry.swift

@@ -76,7 +76,7 @@ public final class Platform: Sendable {
     /// Minimum OS version for Swift concurrency (Swift 5.5). If this is `nil`, the platform does not support Swift concurrency at all.
     fileprivate(set) var minimumOSForSwiftConcurrency: Version? = nil
 
-    /// Minimum OS version for Span in the standard library (Swift 6.2). If this is `nil`, the platform does not support Swift concurrency at all.
+    /// Minimum OS version for Span in the standard library (Swift 6.2). If this is `nil`, Span, MutableSpan, and related types are not available.
     fileprivate(set) var minimumOSForSwiftSpan: Version? = nil
 
     /// The canonical name of the public SDK for this platform.
@@ -296,7 +296,7 @@ extension Platform {
         return version >= minimumSwiftConcurrencyVersion
     }
 
-    /// Determines if the platform natively supports Swift 6.2's Span type. If `false`, then the Swift Span back-compat concurrency libs needs to be copied into the app/framework's bundle.
+    /// Determines if the platform natively supports Swift 6.2's Span type. If `false`, then the Swift Span back-compat lib needs to be copied into the app/framework's bundle.
     public func supportsSwiftSpanNatively(_ scope: MacroEvaluationScope, forceNextMajorVersion: Bool = false, considerTargetDeviceOSVersion: Bool = true) -> Bool? {
         guard let deploymentTarget = self.deploymentTargetMacro else { return false }
 

Sources/SWBCore/SDKRegistry.swift

@@ -452,9 +452,9 @@ public final class SDKVariant: PlatformInfoProvider, Sendable {
     private static func fallbackSwiftVersions(variantName name: String) -> (os: String?, concurrency: String?, span: String?) {
         switch name {
         case "macos", "macosx":
-            return ("10.14.4", "12.0", nil)
+            return ("10.14.4", "12.0", "26.0")
         default:
-            return (nil, nil, nil)
+            return (nil, nil, "26.0")
         }
     }
 

Tests/SWBTaskConstructionTests/SwiftTaskConstructionTests.swift

@@ -71,35 +71,40 @@ fileprivate struct SwiftTaskConstructionTests: CoreBasedTests {
 
     @Test(.requireSDKs(.macOS))
     func swiftAppBasics_preSwiftOS() async throws {
-        try await _testSwiftAppBasics(deploymentTargetVersion: "10.14.0", shouldEmitSwiftRPath: true, shouldFilterSwiftLibs: false, shouldBackDeploySwiftConcurrency: true)
+        try await _testSwiftAppBasics(deploymentTargetVersion: "10.14.0", shouldEmitSwiftRPath: true, shouldFilterSwiftLibs: false, shouldBackDeploySwiftConcurrency: true, shouldBackDeploySwiftSpan: true)
     }
 
     @Test(.requireSDKs(.macOS))
     func swiftAppBasics_postSwiftOS() async throws {
-        try await _testSwiftAppBasics(deploymentTargetVersion: "12.0", shouldEmitSwiftRPath: false, shouldFilterSwiftLibs: true, shouldBackDeploySwiftConcurrency: false)
+        try await _testSwiftAppBasics(deploymentTargetVersion: "12.0", shouldEmitSwiftRPath: false, shouldFilterSwiftLibs: true, shouldBackDeploySwiftConcurrency: false, shouldBackDeploySwiftSpan: true)
+    }
+
+    @Test(.requireSDKs(.macOS))
+    func swiftAppBasics_postSwiftSpan() async throws {
+        try await _testSwiftAppBasics(deploymentTargetVersion: "26.0", shouldEmitSwiftRPath: false, shouldFilterSwiftLibs: true, shouldBackDeploySwiftConcurrency: false, shouldBackDeploySwiftSpan: false)
     }
 
     @Test(.requireSDKs(.macOS))
     func swiftAppBasics_preSwiftOSDeploymentTarget_postSwiftOSTargetDevice() async throws {
-        try await _testSwiftAppBasics(deploymentTargetVersion: "10.14.0", targetDeviceOSVersion: "11.0", targetDevicePlatformName: "macosx", shouldEmitSwiftRPath: true, shouldFilterSwiftLibs: true, shouldBackDeploySwiftConcurrency: true)
+        try await _testSwiftAppBasics(deploymentTargetVersion: "10.14.0", targetDeviceOSVersion: "11.0", targetDevicePlatformName: "macosx", shouldEmitSwiftRPath: true, shouldFilterSwiftLibs: true, shouldBackDeploySwiftConcurrency: true, shouldBackDeploySwiftSpan: true)
     }
 
     @Test(.requireSDKs(.macOS))
     func swiftAppBasics_preSwiftOSDeploymentTarget_postSwiftOSTargetDevice_mixedPlatform() async throws {
-        try await _testSwiftAppBasics(deploymentTargetVersion: "10.14.0", targetDeviceOSVersion: "14.0", targetDevicePlatformName: "iphoneos", shouldEmitSwiftRPath: true, shouldFilterSwiftLibs: false, shouldBackDeploySwiftConcurrency: true)
+        try await _testSwiftAppBasics(deploymentTargetVersion: "10.14.0", targetDeviceOSVersion: "14.0", targetDevicePlatformName: "iphoneos", shouldEmitSwiftRPath: true, shouldFilterSwiftLibs: false, shouldBackDeploySwiftConcurrency: true, shouldBackDeploySwiftSpan: true)
     }
 
     @Test(.requireSDKs(.macOS))
     func swiftAppBasics_postSwiftOSDeploymentTarget_preSwiftConcurrencySupportedNatively() async throws {
-        try await _testSwiftAppBasics(deploymentTargetVersion: "11.0", shouldEmitSwiftRPath: true, shouldFilterSwiftLibs: true, shouldBackDeploySwiftConcurrency: true)
+        try await _testSwiftAppBasics(deploymentTargetVersion: "11.0", shouldEmitSwiftRPath: true, shouldFilterSwiftLibs: true, shouldBackDeploySwiftConcurrency: true, shouldBackDeploySwiftSpan: true)
     }
 
     @Test(.requireSDKs(.macOS), .userDefaults(["AllowRuntimeSearchPathAdditionForSwiftConcurrency": "0"]))
     func swiftAppBasics_postSwiftOSDeploymentTarget_preSwiftConcurrencySupportedNatively_DisallowRpathInjection() async throws {
-        try await _testSwiftAppBasics(deploymentTargetVersion: "11.0", shouldEmitSwiftRPath:false, shouldFilterSwiftLibs: true, shouldBackDeploySwiftConcurrency: true)
+        try await _testSwiftAppBasics(deploymentTargetVersion: "11.0", shouldEmitSwiftRPath:false, shouldFilterSwiftLibs: true, shouldBackDeploySwiftConcurrency: true, shouldBackDeploySwiftSpan: true)
     }
 
-    func _testSwiftAppBasics(deploymentTargetVersion: String, targetDeviceOSVersion: String? = nil, targetDevicePlatformName: String? = nil, toolchain toolchainIdentifier: String = "default", shouldEmitSwiftRPath: Bool, shouldFilterSwiftLibs: Bool, shouldBackDeploySwiftConcurrency: Bool) async throws {
+    func _testSwiftAppBasics(deploymentTargetVersion: String, targetDeviceOSVersion: String? = nil, targetDevicePlatformName: String? = nil, toolchain toolchainIdentifier: String = "default", shouldEmitSwiftRPath: Bool, shouldFilterSwiftLibs: Bool, shouldBackDeploySwiftConcurrency: Bool, shouldBackDeploySwiftSpan: Bool) async throws {
         let swiftCompilerPath = try await self.swiftCompilerPath
         let swiftVersion = try await self.swiftVersion
         let swiftFeatures = try await self.swiftFeatures
@@ -412,7 +417,7 @@ fileprivate struct SwiftTaskConstructionTests: CoreBasedTests {
                 // There should be a 'CopySwiftLibs' task.
                 results.checkTask(.matchTarget(target), .matchRuleType("CopySwiftLibs")) { task -> Void in
                     task.checkRuleInfo(["CopySwiftLibs", "\(SRCROOT)/build/Debug/AppTarget.app"])
-                    task.checkCommandLine(([["builtin-swiftStdLibTool", "--copy", "--verbose", "--scan-executable", "\(SRCROOT)/build/Debug/AppTarget.app/Contents/MacOS/AppTarget", "--scan-folder", "\(SRCROOT)/build/Debug/AppTarget.app/Contents/Frameworks", "--scan-folder", "\(SRCROOT)/build/Debug/AppTarget.app/Contents/PlugIns", "--scan-folder", "\(SRCROOT)/build/Debug/AppTarget.app/Contents/Library/SystemExtensions", "--scan-folder", "\(SRCROOT)/build/Debug/AppTarget.app/Contents/Extensions", "--scan-folder", "\(SRCROOT)/build/Debug/FwkTarget.framework", "--platform", "macosx", "--toolchain", effectiveToolchain.path.str], (toolchainIdentifier == "default" ? [] : ["--toolchain", defaultToolchain.path.str]), ["--destination", "\(SRCROOT)/build/Debug/AppTarget.app/Contents/Frameworks", "--strip-bitcode", "--strip-bitcode-tool", "\(effectiveToolchain.path.str)/usr/bin/bitcode_strip", "--emit-dependency-info", "\(SRCROOT)/build/aProject.build/Debug/AppTarget.build/SwiftStdLibToolInputDependencies.dep"], shouldFilterSwiftLibs ? ["--filter-for-swift-os"] : [], shouldBackDeploySwiftConcurrency ? ["--back-deploy-swift-concurrency"] : []] as [[String]]).reduce([], +))
+                    task.checkCommandLine(([["builtin-swiftStdLibTool", "--copy", "--verbose", "--scan-executable", "\(SRCROOT)/build/Debug/AppTarget.app/Contents/MacOS/AppTarget", "--scan-folder", "\(SRCROOT)/build/Debug/AppTarget.app/Contents/Frameworks", "--scan-folder", "\(SRCROOT)/build/Debug/AppTarget.app/Contents/PlugIns", "--scan-folder", "\(SRCROOT)/build/Debug/AppTarget.app/Contents/Library/SystemExtensions", "--scan-folder", "\(SRCROOT)/build/Debug/AppTarget.app/Contents/Extensions", "--scan-folder", "\(SRCROOT)/build/Debug/FwkTarget.framework", "--platform", "macosx", "--toolchain", effectiveToolchain.path.str], (toolchainIdentifier == "default" ? [] : ["--toolchain", defaultToolchain.path.str]), ["--destination", "\(SRCROOT)/build/Debug/AppTarget.app/Contents/Frameworks", "--strip-bitcode", "--strip-bitcode-tool", "\(effectiveToolchain.path.str)/usr/bin/bitcode_strip", "--emit-dependency-info", "\(SRCROOT)/build/aProject.build/Debug/AppTarget.build/SwiftStdLibToolInputDependencies.dep"], shouldFilterSwiftLibs ? ["--filter-for-swift-os"] : [], shouldBackDeploySwiftConcurrency ? ["--back-deploy-swift-concurrency"] : [], shouldBackDeploySwiftSpan ? ["--back-deploy-swift-span"] : []] as [[String]]).reduce([], +))
 
                     task.checkInputs([
                         .path("\(SRCROOT)/build/Debug/AppTarget.app/Contents/MacOS/AppTarget"),

Tests/SWBTaskConstructionTests/UnitTestTaskConstructionTests.swift

@@ -3138,7 +3138,7 @@ fileprivate struct UnitTestTaskConstructionTests: CoreBasedTests {
                 // There should be a 'CopySwiftLibs' task that includes a reference to the libXCTestSwiftSupport.dylib executable.
                 results.checkTask(.matchTarget(target), .matchRuleType("CopySwiftLibs")) { task in
                     task.checkRuleInfo(["CopySwiftLibs", "\(SRCROOT)/build/Debug-iphoneos/UITestTarget-Runner.app/PlugIns/UITestTarget.xctest"])
-                    task.checkCommandLine(["builtin-swiftStdLibTool", "--copy", "--verbose", "--sign", "105DE4E702E4", "--scan-executable", "\(SRCROOT)/build/Debug-iphoneos/UITestTarget-Runner.app/PlugIns/UITestTarget.xctest/UITestTarget", "--scan-folder", "\(SRCROOT)/build/Debug-iphoneos/UITestTarget-Runner.app/PlugIns/UITestTarget.xctest/Frameworks", "--scan-folder", "\(SRCROOT)/build/Debug-iphoneos/UITestTarget-Runner.app/PlugIns/UITestTarget.xctest/PlugIns", "--scan-folder", "\(SRCROOT)/build/Debug-iphoneos/UITestTarget-Runner.app/PlugIns/UITestTarget.xctest/SystemExtensions", "--scan-folder", "\(SRCROOT)/build/Debug-iphoneos/UITestTarget-Runner.app/PlugIns/UITestTarget.xctest/Extensions", "--platform", "iphoneos", "--toolchain", "\(core.developerPath.path.str)/Toolchains/XcodeDefault.xctoolchain", "--destination", "\(SRCROOT)/build/Debug-iphoneos/UITestTarget-Runner.app/PlugIns/UITestTarget.xctest/Frameworks", "--strip-bitcode", "--scan-executable", "\(core.developerPath.path.str)/Platforms/iPhoneOS.platform/Developer/usr/lib/libXCTestSwiftSupport.dylib", "--strip-bitcode-tool", "\(defaultToolchain.path.str)/usr/bin/bitcode_strip", "--emit-dependency-info", "\(SRCROOT)/build/aProject.build/Debug-iphoneos/UITestTarget.build/SwiftStdLibToolInputDependencies.dep", "--back-deploy-swift-concurrency"])
+                    task.checkCommandLine(["builtin-swiftStdLibTool", "--copy", "--verbose", "--sign", "105DE4E702E4", "--scan-executable", "\(SRCROOT)/build/Debug-iphoneos/UITestTarget-Runner.app/PlugIns/UITestTarget.xctest/UITestTarget", "--scan-folder", "\(SRCROOT)/build/Debug-iphoneos/UITestTarget-Runner.app/PlugIns/UITestTarget.xctest/Frameworks", "--scan-folder", "\(SRCROOT)/build/Debug-iphoneos/UITestTarget-Runner.app/PlugIns/UITestTarget.xctest/PlugIns", "--scan-folder", "\(SRCROOT)/build/Debug-iphoneos/UITestTarget-Runner.app/PlugIns/UITestTarget.xctest/SystemExtensions", "--scan-folder", "\(SRCROOT)/build/Debug-iphoneos/UITestTarget-Runner.app/PlugIns/UITestTarget.xctest/Extensions", "--platform", "iphoneos", "--toolchain", "\(core.developerPath.path.str)/Toolchains/XcodeDefault.xctoolchain", "--destination", "\(SRCROOT)/build/Debug-iphoneos/UITestTarget-Runner.app/PlugIns/UITestTarget.xctest/Frameworks", "--strip-bitcode", "--scan-executable", "\(core.developerPath.path.str)/Platforms/iPhoneOS.platform/Developer/usr/lib/libXCTestSwiftSupport.dylib", "--strip-bitcode-tool", "\(defaultToolchain.path.str)/usr/bin/bitcode_strip", "--emit-dependency-info", "\(SRCROOT)/build/aProject.build/Debug-iphoneos/UITestTarget.build/SwiftStdLibToolInputDependencies.dep", "--back-deploy-swift-concurrency", "--back-deploy-swift-span"])
                 }
             }