Use new Swift Build run destination API for SDK's (#9527)

cmcgee1024 · web-flow · commit 5123bf07a879 · 2026-01-21T12:27:18.000-05:00
When using an SDK with the `--swift-sdk` build parameter this
information is provided to Swift Build as part of the build request so
that it can use it instead of the host SDK.
diff --git a/.swift-version b/.swift-version
@@ -1 +1 @@
-6.2.0
+6.2.3
diff --git a/Sources/PackageModel/SwiftSDKs/SwiftSDK.swift b/Sources/PackageModel/SwiftSDKs/SwiftSDK.swift
@@ -265,6 +265,8 @@ public struct SwiftSDK: Equatable {
     /// deserialization.
     public private(set) var toolset: Toolset
 
+    public private(set) var swiftSDKManifest: Basics.AbsolutePath?
+
     /// The paths associated with a Swift SDK. The Path type can be a `String`
     /// to encapsulate the arguments for the `SwiftSDKConfigurationStore.configure`
     /// function, or can be a fully-realized `AbsolutePath` when deserialized from a configuration.
@@ -499,12 +501,14 @@ public struct SwiftSDK: Equatable {
         hostTriple: Triple? = nil,
         targetTriple: Triple? = nil,
         toolset: Toolset,
+        swiftSDKManifest: Basics.AbsolutePath? = nil,
         pathsConfiguration: PathsConfiguration<Basics.AbsolutePath>,
         xctestSupport: XCTestSupport = .supported
     ) {
         self.hostTriple = hostTriple
         self.targetTriple = targetTriple
         self.toolset = toolset
+        self.swiftSDKManifest = swiftSDKManifest
         self.pathsConfiguration = pathsConfiguration
         self.xctestSupport = xctestSupport
     }
@@ -942,7 +946,8 @@ extension SwiftSDK {
                     targetTriple: triple,
                     properties: properties,
                     toolset: toolset,
-                    swiftSDKDirectory: swiftSDKDirectory
+                    swiftSDKDirectory: swiftSDKDirectory,
+                    swiftSDKManifest: path,
                 )
             }
 
@@ -973,7 +978,8 @@ extension SwiftSDK {
                     targetTriple: triple,
                     properties: properties,
                     toolset: toolset,
-                    swiftSDKDirectory: swiftSDKDirectory
+                    swiftSDKDirectory: swiftSDKDirectory,
+                    swiftSDKManifest: path,
                 )
             }
         default:
@@ -991,11 +997,13 @@ extension SwiftSDK {
         targetTriple: Triple,
         properties: SwiftSDKMetadataV4.TripleProperties,
         toolset: Toolset = .init(),
-        swiftSDKDirectory: Basics.AbsolutePath? = nil
+        swiftSDKDirectory: Basics.AbsolutePath? = nil,
+        swiftSDKManifest: Basics.AbsolutePath? = nil,
     ) throws {
         self.init(
             targetTriple: targetTriple,
             toolset: toolset,
+            swiftSDKManifest: swiftSDKManifest,
             pathsConfiguration: try .init(properties, swiftSDKDirectory: swiftSDKDirectory)
         )
     }
@@ -1010,11 +1018,13 @@ extension SwiftSDK {
         targetTriple: Triple,
         properties: SerializedDestinationV3.TripleProperties,
         toolset: Toolset = .init(),
-        swiftSDKDirectory: Basics.AbsolutePath? = nil
+        swiftSDKDirectory: Basics.AbsolutePath? = nil,
+        swiftSDKManifest: Basics.AbsolutePath? = nil,
     ) throws {
         self.init(
             targetTriple: targetTriple,
             toolset: toolset,
+            swiftSDKManifest: swiftSDKManifest,
             pathsConfiguration: try .init(properties, swiftSDKDirectory: swiftSDKDirectory)
         )
     }
diff --git a/Sources/PackageModel/Toolchain.swift b/Sources/PackageModel/Toolchain.swift
@@ -75,6 +75,8 @@ public protocol Toolchain {
     /// Additional flags to be passed to the C++ compiler.
     @available(*, deprecated, message: "use extraFlags.cxxCompilerFlags instead")
     var extraCPPFlags: [String] { get }
+
+    var swiftSDK: SwiftSDK { get }
 }
 
 extension Toolchain {
diff --git a/Sources/SwiftBuildSupport/SwiftBuildSystem.swift b/Sources/SwiftBuildSupport/SwiftBuildSystem.swift
@@ -703,36 +703,45 @@ public final class SwiftBuildSystem: SPMBuildCore.BuildSystem {
     }
 
     private func makeRunDestination() -> SwiftBuild.SWBRunDestinationInfo {
-        let platformName: String
-        let sdkName: String
-        if self.buildParameters.triple.isAndroid() {
-            // Android triples are identified by the environment part of the triple
-            platformName = "android"
-            sdkName = platformName
-        } else if self.buildParameters.triple.isWasm {
-            // Swift Build uses webassembly instead of wasi as the platform name
-            platformName = "webassembly"
-            sdkName = platformName
+        if let sdkManifestPath = self.buildParameters.toolchain.swiftSDK.swiftSDKManifest {
+            return SwiftBuild.SWBRunDestinationInfo(
+                buildTarget: .swiftSDK(sdkManifestPath: sdkManifestPath.pathString, triple: self.buildParameters.triple.tripleString),
+                targetArchitecture: buildParameters.triple.archName,
+                supportedArchitectures: [],
+                disableOnlyActiveArch: (buildParameters.architectures?.count ?? 1) > 1,
+            )
         } else {
-            platformName = self.buildParameters.triple.darwinPlatform?.platformName ?? self.buildParameters.triple.osNameUnversioned
-            sdkName = platformName
-        }
+            let platformName: String
+            let sdkName: String
 
-        let sdkVariant: String?
-        if self.buildParameters.triple.environment == .macabi {
-            sdkVariant = "iosmac"
-        } else {
-            sdkVariant = nil
-        }
+            if self.buildParameters.triple.isAndroid() {
+                // Android triples are identified by the environment part of the triple
+                platformName = "android"
+                sdkName = platformName
+            } else {
+                platformName = self.buildParameters.triple.darwinPlatform?.platformName ?? self.buildParameters.triple.osNameUnversioned
+                sdkName = platformName
+            }
 
-        return SwiftBuild.SWBRunDestinationInfo(
-            platform: platformName,
-            sdk: sdkName,
-            sdkVariant: sdkVariant,
-            targetArchitecture: buildParameters.triple.archName,
-            supportedArchitectures: [],
-            disableOnlyActiveArch: (buildParameters.architectures?.count ?? 1) > 1
-        )
+            let sdkVariant: String?
+            if self.buildParameters.triple.environment == .macabi {
+                sdkVariant = "iosmac"
+            } else {
+                sdkVariant = nil
+            }
+
+            return SwiftBuild.SWBRunDestinationInfo(
+                buildTarget: .toolchainSDK(
+                    platform: platformName,
+                    sdk: sdkName,
+                    sdkVariant: sdkVariant
+                ),
+                targetArchitecture: buildParameters.triple.archName,
+                supportedArchitectures: [],
+                disableOnlyActiveArch: (buildParameters.architectures?.count ?? 1) > 1,
+                hostTargetedPlatform: nil
+            )
+        }
     }
 
     internal func makeBuildParameters(
@@ -867,12 +876,19 @@ public final class SwiftBuildSystem: SPMBuildCore.BuildSystem {
                 + buildParameters.flags.swiftCompilerFlags.map { $0.shellEscaped() }
         ).joined(separator: " ")
 
-        settings["OTHER_LDFLAGS"] = (
-            verboseFlag + // clang will be invoked to link so the verbose flag is valid for it
-                ["$(inherited)"]
-                + buildParameters.toolchain.extraFlags.linkerFlags.asSwiftcLinkerFlags().map { $0.shellEscaped() }
-                + buildParameters.flags.linkerFlags.asSwiftcLinkerFlags().map { $0.shellEscaped() }
-        ).joined(separator: " ")
+        let inherited = ["$(inherited)"]
+
+        let buildParametersLinkFlags =
+            buildParameters.toolchain.extraFlags.linkerFlags.asSwiftcLinkerFlags().map { $0.shellEscaped() }
+            + buildParameters.flags.linkerFlags.asSwiftcLinkerFlags().map { $0.shellEscaped() }
+
+        var otherLdFlags =
+                verboseFlag  // clang will be invoked to link so the verbose flag is valid for it
+                + inherited
+
+        otherLdFlags += buildParametersLinkFlags
+
+        settings["OTHER_LDFLAGS"] = otherLdFlags.joined(separator: " ")
 
         // Optionally also set the list of architectures to build for.
         if let architectures = buildParameters.architectures, !architectures.isEmpty {
diff --git a/Sources/_InternalBuildTestSupport/MockBuildTestHelper.swift b/Sources/_InternalBuildTestSupport/MockBuildTestHelper.swift
@@ -28,7 +28,7 @@ import Testing
 public func mockBuildPlan(
     buildPath: AbsolutePath? = nil,
     environment: BuildEnvironment,
-    toolchain: PackageModel.Toolchain = MockToolchain(),
+    toolchain: PackageModel.Toolchain = try! MockToolchain(),
     graph: ModulesGraph,
     commonFlags: PackageModel.BuildFlags = .init(),
     indexStoreMode: BuildParameters.IndexStoreMode = .off,
@@ -61,7 +61,7 @@ public func mockBuildPlan(
     config: BuildConfiguration = .debug,
     triple: Basics.Triple? = nil,
     platform: PackageModel.Platform? = nil,
-    toolchain: PackageModel.Toolchain = MockToolchain(),
+    toolchain: PackageModel.Toolchain = try! MockToolchain(),
     graph: ModulesGraph,
     commonFlags: PackageModel.BuildFlags = .init(),
     indexStoreMode: BuildParameters.IndexStoreMode = .off,
diff --git a/Sources/_InternalTestSupport/MockBuildTestHelper.swift b/Sources/_InternalTestSupport/MockBuildTestHelper.swift
@@ -41,6 +41,7 @@ public struct MockToolchain: PackageModel.Toolchain {
     public let swiftPMLibrariesLocation = ToolchainConfiguration.SwiftPMLibrariesLocation(
         manifestLibraryPath: AbsolutePath("/fake/manifestLib/path"), pluginLibraryPath: AbsolutePath("/fake/pluginLibrary/path")
     )
+    public var swiftSDK: PackageModel.SwiftSDK
 
     public func getClangCompiler() throws -> AbsolutePath {
         "/fake/path/to/clang"
@@ -54,10 +55,11 @@ public struct MockToolchain: PackageModel.Toolchain {
         #endif
     }
 
-    public init(swiftResourcesPath: AbsolutePath? = nil) {
+    public init(swiftResourcesPath: AbsolutePath? = nil) throws {
         self.swiftResourcesPath = swiftResourcesPath
         self.metalToolchainPath = nil
         self.metalToolchainId = nil
+        self.swiftSDK = try .hostSwiftSDK()
     }
 }
 
@@ -84,7 +86,7 @@ public func mockBuildParameters(
     destination: BuildParameters.Destination,
     buildPath: AbsolutePath? = nil,
     config: BuildConfiguration = .debug,
-    toolchain: PackageModel.Toolchain = MockToolchain(),
+    toolchain: PackageModel.Toolchain = try! MockToolchain(),
     flags: PackageModel.BuildFlags = PackageModel.BuildFlags(),
     buildSystemKind: BuildSystemProvider.Kind = .native,
     shouldLinkStaticSwiftStdlib: Bool = false,
diff --git a/Tests/BuildTests/ClangTargetBuildDescriptionTests.swift b/Tests/BuildTests/ClangTargetBuildDescriptionTests.swift
@@ -26,7 +26,7 @@ final class ClangTargetBuildDescriptionTests: XCTestCase {
     }
 
     func testSwiftCorelibsFoundationIncludeWorkaround() throws {
-        let toolchain = MockToolchain(swiftResourcesPath: AbsolutePath("/fake/path/lib/swift"))
+        let toolchain = try MockToolchain(swiftResourcesPath: AbsolutePath("/fake/path/lib/swift"))
 
         let macosParameters = mockBuildParameters(destination: .target, toolchain: toolchain, triple: .macOS)
         let linuxParameters = mockBuildParameters(destination: .target, toolchain: toolchain, triple: .arm64Linux)
diff --git a/Tests/PackageModelTests/SwiftSDKTests.swift b/Tests/PackageModelTests/SwiftSDKTests.swift
@@ -341,6 +341,7 @@ private let parsedToolsetNoRootDestination = SwiftSDK(
         ],
         rootPaths: []
     ),
+    swiftSDKManifest: toolsetNoRootSwiftSDKv4.path,
     pathsConfiguration: .init(
         sdkRootPath: bundleRootPath.appending(sdkRootDir),
         toolsetPaths: ["/tools/otherToolsNoRoot.json"]
@@ -359,6 +360,7 @@ private let parsedToolsetRootDestination = SwiftSDK(
         ],
         rootPaths: [try! AbsolutePath(validating: "/custom")]
     ),
+    swiftSDKManifest: toolsetRootSwiftSDKv4.path,
     pathsConfiguration: .init(
         sdkRootPath: bundleRootPath.appending(sdkRootDir),
         toolsetPaths: ["/tools/someToolsWithRoot.json", "/tools/otherToolsNoRoot.json"]
@@ -376,6 +378,7 @@ private let parsedToolsetNoSDKRootPathDestination = SwiftSDK(
         ],
         rootPaths: []
     ),
+    swiftSDKManifest: androidWithoutSDKRootPathSwiftSDKv4.path,
     pathsConfiguration: .init(
         sdkRootPath: nil,
         toolsetPaths: ["/tools/otherToolsNoRoot.json"]
@@ -455,7 +458,24 @@ final class SwiftSDKTests: XCTestCase {
             observabilityScope: observability
         )
 
-        XCTAssertEqual(toolsetNoRootDestinationV3Decoded, [parsedToolsetNoRootDestination])
+        let parsedToolsetNoRootDestinationV3 = SwiftSDK(
+            targetTriple: linuxGNUTargetTriple,
+            toolset: .init(
+                knownTools: [
+                    .librarian: .init(path: try! AbsolutePath(validating: "\(usrBinTools[.librarian]!)")),
+                    .linker: .init(path: try! AbsolutePath(validating: "\(usrBinTools[.linker]!)")),
+                    .debugger: .init(path: try! AbsolutePath(validating: "\(usrBinTools[.debugger]!)")),
+                ],
+                rootPaths: []
+            ),
+            swiftSDKManifest: toolsetNoRootDestinationV3.path,
+            pathsConfiguration: .init(
+                sdkRootPath: bundleRootPath.appending(sdkRootDir),
+                toolsetPaths: ["/tools/otherToolsNoRoot.json"]
+                    .map { try! AbsolutePath(validating: $0) }
+            )
+        )
+        XCTAssertEqual(toolsetNoRootDestinationV3Decoded, [parsedToolsetNoRootDestinationV3])
 
         let toolsetRootDestinationV3Decoded = try SwiftSDK.decode(
             fromFile: toolsetRootDestinationV3.path,
@@ -464,7 +484,26 @@ final class SwiftSDKTests: XCTestCase {
             observabilityScope: observability
         )
 
-        XCTAssertEqual(toolsetRootDestinationV3Decoded, [parsedToolsetRootDestination])
+        let parsedToolsetRootDestinationV3Decoded = SwiftSDK(
+            targetTriple: linuxGNUTargetTriple,
+            toolset: .init(
+                knownTools: [
+                    .cCompiler: .init(extraCLIOptions: cCompilerOptions),
+                    .librarian: .init(path: try! AbsolutePath(validating: "\(usrBinTools[.librarian]!)")),
+                    .linker: .init(path: try! AbsolutePath(validating: "\(usrBinTools[.linker]!)")),
+                    .debugger: .init(path: try! AbsolutePath(validating: "\(usrBinTools[.debugger]!)")),
+                ],
+                rootPaths: [try! AbsolutePath(validating: "/custom")]
+            ),
+            swiftSDKManifest: toolsetRootDestinationV3.path,
+            pathsConfiguration: .init(
+                sdkRootPath: bundleRootPath.appending(sdkRootDir),
+                toolsetPaths: ["/tools/someToolsWithRoot.json", "/tools/otherToolsNoRoot.json"]
+                    .map { try! AbsolutePath(validating: $0) }
+            )
+        )
+
+        XCTAssertEqual(toolsetRootDestinationV3Decoded, [parsedToolsetRootDestinationV3Decoded])
 
         XCTAssertThrowsError(try SwiftSDK.decode(
             fromFile: missingToolsetDestinationV3.path,

Original file line number	Diff line number	Diff line change
`@@ -75,6 +75,8 @@ public protocol Toolchain {`
`75`	`75`	`/// Additional flags to be passed to the C++ compiler.`
`76`	`76`	`@available(*, deprecated, message: "use extraFlags.cxxCompilerFlags instead")`
`77`	`77`	`var extraCPPFlags: [String] { get }`
	`78`	`+`
	`79`	`+ var swiftSDK: SwiftSDK { get }`
`78`	`80`	`}`
`79`	`81`
`80`	`82`	`extension Toolchain {`
Original file line number	Diff line number	Diff line change
`@@ -26,7 +26,7 @@ final class ClangTargetBuildDescriptionTests: XCTestCase {`
`26`	`26`	`}`
`27`	`27`
`28`	`28`	`func testSwiftCorelibsFoundationIncludeWorkaround() throws {`
`29`		`- let toolchain = MockToolchain(swiftResourcesPath: AbsolutePath("/fake/path/lib/swift"))`
	`29`	`+ let toolchain = try MockToolchain(swiftResourcesPath: AbsolutePath("/fake/path/lib/swift"))`
`30`	`30`
`31`	`31`	`let macosParameters = mockBuildParameters(destination: .target, toolchain: toolchain, triple: .macOS)`
`32`	`32`	`let linuxParameters = mockBuildParameters(destination: .target, toolchain: toolchain, triple: .arm64Linux)`