Look up WasmKit in the host toolchain directory

Sources/PackageModel/SwiftSDKs/SwiftSDK.swift

@@ -934,9 +934,7 @@ extension SwiftSDK {
                     [:]
                 }
                 let pathStrings = properties.toolsetPaths ?? []
-                let toolset = try pathStrings.reduce(
-                    into: Toolset(knownTools: defaultTools, rootPaths: [hostToolchainBinDir])
-                ) {
+                let toolset = try pathStrings.reduce(into: Toolset(knownTools: defaultTools, rootPaths: [])) {
                     try $0.merge(
                         with: Toolset(
                             from: .init(validating: $1, relativeTo: swiftSDKDirectory),

Sources/SwiftSDKCommand/Configuration/ConfigurationSubcommand.swift

@@ -45,13 +45,15 @@ protocol ConfigurationSubcommand: SwiftSDKSubcommand {
 extension ConfigurationSubcommand {
     func run(
         hostTriple: Triple,
+        hostToolchain: UserToolchain,
         _ swiftSDKsDirectory: AbsolutePath,
         _ observabilityScope: ObservabilityScope
     ) throws {
         fputs("warning: `swift sdk configuration` command is deprecated and will be removed in a future version of SwiftPM. Use `swift sdk configure` instead.\n", stderr)
 
         let bundleStore = SwiftSDKBundleStore(
             swiftSDKsDirectory: swiftSDKsDirectory,
+            hostToolchainBinDir: hostToolchain.swiftCompilerPath.parentDirectory,
             fileSystem: self.fileSystem,
             observabilityScope: observabilityScope,
             outputHandler: { print($0) }

Sources/SwiftSDKCommand/ConfigureSwiftSDK.swift

@@ -123,6 +123,7 @@ struct ConfigureSwiftSDK: AsyncParsableCommand {
         do {
             let bundleStore = SwiftSDKBundleStore(
                 swiftSDKsDirectory: swiftSDKsDirectory,
+                hostToolchainBinDir: hostToolchain.swiftCompilerPath.parentDirectory,
                 fileSystem: self.fileSystem,
                 observabilityScope: observabilityScope,
                 outputHandler: { print($0) }

Sources/SwiftSDKCommand/InstallSwiftSDK.swift

@@ -50,6 +50,7 @@ struct InstallSwiftSDK: SwiftSDKSubcommand {
 
     func run(
         hostTriple: Triple,
+        hostToolchain: UserToolchain,
         _ swiftSDKsDirectory: AbsolutePath,
         _ observabilityScope: ObservabilityScope
     ) async throws {
@@ -58,6 +59,7 @@ struct InstallSwiftSDK: SwiftSDKSubcommand {
 
         let store = SwiftSDKBundleStore(
             swiftSDKsDirectory: swiftSDKsDirectory,
+            hostToolchainBinDir: hostToolchain.swiftCompilerPath.parentDirectory,
             fileSystem: self.fileSystem,
             observabilityScope: observabilityScope,
             outputHandler: { print($0.description) },

Sources/SwiftSDKCommand/ListSwiftSDKs.swift

@@ -32,11 +32,13 @@ package struct ListSwiftSDKs: SwiftSDKSubcommand {
 
     func run(
         hostTriple: Triple,
+        hostToolchain: UserToolchain,
         _ swiftSDKsDirectory: AbsolutePath,
         _ observabilityScope: ObservabilityScope
     ) throws {
         let store = SwiftSDKBundleStore(
             swiftSDKsDirectory: swiftSDKsDirectory,
+            hostToolchainBinDir: hostToolchain.swiftCompilerPath.parentDirectory,
             fileSystem: fileSystem,
             observabilityScope: observabilityScope,
             outputHandler: { print($0.description) }

Sources/SwiftSDKCommand/RemoveSwiftSDK.swift

@@ -34,6 +34,7 @@ package struct RemoveSwiftSDK: SwiftSDKSubcommand {
 
     func run(
         hostTriple: Triple,
+        hostToolchain: UserToolchain,
         _ swiftSDKsDirectory: Basics.AbsolutePath,
         _ observabilityScope: ObservabilityScope
     ) async throws {
@@ -47,6 +48,7 @@ package struct RemoveSwiftSDK: SwiftSDKSubcommand {
         } else {
             let bundleStore = SwiftSDKBundleStore(
                 swiftSDKsDirectory: swiftSDKsDirectory,
+                hostToolchainBinDir: hostToolchain.swiftCompilerPath.parentDirectory,
                 fileSystem: self.fileSystem,
                 observabilityScope: observabilityScope,
                 outputHandler: { print($0) }

Sources/SwiftSDKCommand/SwiftSDKSubcommand.swift

@@ -30,6 +30,7 @@ protocol SwiftSDKSubcommand: AsyncParsableCommand {
     ///   - observabilityScope: observability scope used for logging.
     func run(
         hostTriple: Triple,
+        hostToolchain: UserToolchain,
         _ swiftSDKsDirectory: AbsolutePath,
         _ observabilityScope: ObservabilityScope
     ) async throws
@@ -71,7 +72,7 @@ extension SwiftSDKSubcommand {
 
         var commandError: Error? = nil
         do {
-            try await self.run(hostTriple: triple, swiftSDKsDirectory, observabilityScope)
+            try await self.run(hostTriple: triple, hostToolchain: hostToolchain, swiftSDKsDirectory, observabilityScope)
             if observabilityScope.errorsReported {
                 throw ExitCode.failure
             }

Tests/PackageModelTests/SwiftSDKBundleTests.swift

@@ -167,6 +167,7 @@ final class SwiftSDKBundleTests: XCTestCase {
                 var output = [SwiftSDKBundleStore.Output]()
                 let store = SwiftSDKBundleStore(
                     swiftSDKsDirectory: tmpDir,
+                    hostToolchainBinDir: tmpDir,
                     fileSystem: localFileSystem,
                     observabilityScope: observabilityScope,
                     outputHandler: {
@@ -208,6 +209,7 @@ final class SwiftSDKBundleTests: XCTestCase {
         var output = [SwiftSDKBundleStore.Output]()
         let store = SwiftSDKBundleStore(
             swiftSDKsDirectory: swiftSDKsDirectory,
+            hostToolchainBinDir: "/tmp",
             fileSystem: fileSystem,
             observabilityScope: system.topScope,
             outputHandler: {
@@ -300,6 +302,7 @@ final class SwiftSDKBundleTests: XCTestCase {
         var output = [SwiftSDKBundleStore.Output]()
         let store = SwiftSDKBundleStore(
             swiftSDKsDirectory: swiftSDKsDirectory,
+            hostToolchainBinDir: "/tmp",
             fileSystem: fileSystem,
             observabilityScope: system.topScope,
             outputHandler: {
@@ -340,6 +343,7 @@ final class SwiftSDKBundleTests: XCTestCase {
         var output = [SwiftSDKBundleStore.Output]()
         let store = SwiftSDKBundleStore(
             swiftSDKsDirectory: swiftSDKsDirectory,
+            hostToolchainBinDir: "/tmp",
             fileSystem: fileSystem,
             observabilityScope: system.topScope,
             outputHandler: {
@@ -381,9 +385,11 @@ final class SwiftSDKBundleTests: XCTestCase {
         let system = ObservabilitySystem.makeForTesting()
         let hostSwiftSDK = try SwiftSDK.hostSwiftSDK(environment: [:])
         let hostTriple = try! Triple("arm64-apple-macosx14.0")
+        let hostToolchainBinDir = AbsolutePath("/tmp")
         let archiver = MockArchiver()
         let store = SwiftSDKBundleStore(
             swiftSDKsDirectory: swiftSDKsDirectory,
+            hostToolchainBinDir: hostToolchainBinDir,
             fileSystem: fileSystem,
             observabilityScope: system.topScope,
             outputHandler: { _ in }
@@ -434,7 +440,7 @@ final class SwiftSDKBundleTests: XCTestCase {
             // With a target SDK selector, SDK should be chosen from the store.
             XCTAssertEqual(targetSwiftSDK.targetTriple, targetTriple)
             // No toolset in the SDK, so it should be the same as the host SDK.
-            XCTAssertEqual(targetSwiftSDK.toolset.rootPaths, hostSwiftSDK.toolset.rootPaths)
+            XCTAssertEqual(targetSwiftSDK.toolset.rootPaths, [hostToolchainBinDir] + hostSwiftSDK.toolset.rootPaths)
         }
 
         do {
@@ -447,7 +453,10 @@ final class SwiftSDKBundleTests: XCTestCase {
                 fileSystem: fileSystem
             )
             // With toolset in the target SDK, it should contain the host toolset roots at the end.
-            XCTAssertEqual(targetSwiftSDK.toolset.rootPaths, [toolsetRootPath] + hostSwiftSDK.toolset.rootPaths)
+            XCTAssertEqual(
+                targetSwiftSDK.toolset.rootPaths,
+                [toolsetRootPath, hostToolchainBinDir] + hostSwiftSDK.toolset.rootPaths
+            )
         }
 
         do {

Tests/PackageModelTests/SwiftSDKTests.swift

@@ -25,6 +25,7 @@ private let hostTriple = try! Triple("arm64-apple-darwin22.1.0")
 private let olderHostTriple = try! Triple("arm64-apple-darwin20.1.0")
 private let linuxGNUTargetTriple = try! Triple("x86_64-unknown-linux-gnu")
 private let linuxMuslTargetTriple = try! Triple("x86_64-unknown-linux-musl")
+private let wasiTargetTriple = try! Triple("wasm32-unknown-wasi")
 private let extraFlags = BuildFlags(
     cCompilerFlags: ["-fintegrated-as"],
     cxxCompilerFlags: ["-fno-exceptions"],
@@ -139,6 +140,22 @@ private let invalidToolsetDestinationV3 = (
     """# as SerializedJSON
 )
 
+
+private let wasiWithoutToolsetsSwiftSDKv4 = (
+    path: bundleRootPath.appending(component: "wasiSwiftSDKv4.json"),
+    json: #"""
+    {
+        "targetTriples": {
+            "\#(wasiTargetTriple.tripleString)": {
+                "sdkRootPath": "\#(sdkRootDir)",
+                "toolsetPaths": []
+            }
+        },
+        "schemaVersion": "4.0"
+    }
+    """# as SerializedJSON
+)
+
 private let toolsetNoRootSwiftSDKv4 = (
     path: bundleRootPath.appending(component: "toolsetNoRootSwiftSDKv4.json"),
     json: #"""
@@ -347,12 +364,13 @@ private let testFiles: [(path: AbsolutePath, json: SerializedJSON)] = [
     missingToolsetSwiftSDKv4,
     invalidVersionSwiftSDKv4,
     invalidToolsetSwiftSDKv4,
+    wasiWithoutToolsetsSwiftSDKv4,
     otherToolsNoRoot,
     someToolsWithRoot,
     invalidToolset,
 ]
 
-final class DestinationTests: XCTestCase {
+final class SwiftSDKTests: XCTestCase {
     func testDestinationCodable() throws {
         let fs = InMemoryFileSystem()
         try fs.createDirectory(AbsolutePath(validating: "/tools"))
@@ -367,6 +385,7 @@ final class DestinationTests: XCTestCase {
 
         let destinationV1Decoded = try SwiftSDK.decode(
             fromFile: destinationV1.path,
+            hostToolchainBinDir: bundleRootPath.appending(toolchainBinDir),
             fileSystem: fs,
             observabilityScope: observability
         )
@@ -389,6 +408,7 @@ final class DestinationTests: XCTestCase {
 
         let destinationV2Decoded = try SwiftSDK.decode(
             fromFile: destinationV2.path,
+            hostToolchainBinDir: toolchainBinAbsolutePath,
             fileSystem: fs,
             observabilityScope: observability
         )
@@ -397,6 +417,7 @@ final class DestinationTests: XCTestCase {
 
         let toolsetNoRootDestinationV3Decoded = try SwiftSDK.decode(
             fromFile: toolsetNoRootDestinationV3.path,
+            hostToolchainBinDir: toolchainBinAbsolutePath,
             fileSystem: fs,
             observabilityScope: observability
         )
@@ -405,6 +426,7 @@ final class DestinationTests: XCTestCase {
 
         let toolsetRootDestinationV3Decoded = try SwiftSDK.decode(
             fromFile: toolsetRootDestinationV3.path,
+            hostToolchainBinDir: toolchainBinAbsolutePath,
             fileSystem: fs,
             observabilityScope: observability
         )
@@ -413,6 +435,7 @@ final class DestinationTests: XCTestCase {
 
         XCTAssertThrowsError(try SwiftSDK.decode(
             fromFile: missingToolsetDestinationV3.path,
+            hostToolchainBinDir: toolchainBinAbsolutePath,
             fileSystem: fs,
             observabilityScope: observability
         )) {
@@ -429,12 +452,14 @@ final class DestinationTests: XCTestCase {
         }
         XCTAssertThrowsError(try SwiftSDK.decode(
             fromFile: invalidVersionDestinationV3.path,
+            hostToolchainBinDir: bundleRootPath.appending(toolchainBinDir),
             fileSystem: fs,
             observabilityScope: observability
         ))
 
         XCTAssertThrowsError(try SwiftSDK.decode(
             fromFile: invalidToolsetDestinationV3.path,
+            hostToolchainBinDir: bundleRootPath.appending(toolchainBinDir),
             fileSystem: fs,
             observabilityScope: observability
         )) {
@@ -447,6 +472,7 @@ final class DestinationTests: XCTestCase {
 
         let toolsetNoRootSwiftSDKv4Decoded = try SwiftSDK.decode(
             fromFile: toolsetNoRootSwiftSDKv4.path,
+            hostToolchainBinDir: toolchainBinAbsolutePath,
             fileSystem: fs,
             observabilityScope: observability
         )
@@ -455,6 +481,7 @@ final class DestinationTests: XCTestCase {
 
         let toolsetRootSwiftSDKv4Decoded = try SwiftSDK.decode(
             fromFile: toolsetRootSwiftSDKv4.path,
+            hostToolchainBinDir: toolchainBinAbsolutePath,
             fileSystem: fs,
             observabilityScope: observability
         )
@@ -463,6 +490,7 @@ final class DestinationTests: XCTestCase {
 
         XCTAssertThrowsError(try SwiftSDK.decode(
             fromFile: missingToolsetSwiftSDKv4.path,
+            hostToolchainBinDir: toolchainBinAbsolutePath,
             fileSystem: fs,
             observabilityScope: observability
         )) {
@@ -479,12 +507,14 @@ final class DestinationTests: XCTestCase {
         }
         XCTAssertThrowsError(try SwiftSDK.decode(
             fromFile: invalidVersionSwiftSDKv4.path,
+            hostToolchainBinDir: toolchainBinAbsolutePath,
             fileSystem: fs,
             observabilityScope: observability
         ))
 
         XCTAssertThrowsError(try SwiftSDK.decode(
             fromFile: invalidToolsetSwiftSDKv4.path,
+            hostToolchainBinDir: toolchainBinAbsolutePath,
             fileSystem: fs,
             observabilityScope: observability
         )) {
@@ -494,6 +524,23 @@ final class DestinationTests: XCTestCase {
                     .hasPrefix("Couldn't parse toolset configuration at `\(toolsetDefinition)`: ") ?? false
             )
         }
+
+        let wasiWithoutToolsetsDecoded = try SwiftSDK.decode(
+            fromFile: wasiWithoutToolsetsSwiftSDKv4.path,
+            hostToolchainBinDir: toolchainBinAbsolutePath,
+            fileSystem: fs,
+            observabilityScope: observability
+        )
+
+        XCTAssertEqual(wasiWithoutToolsetsDecoded.count, 1)
+
+        let wasmKitProperties = Toolset.ToolProperties(
+            path: toolchainBinAbsolutePath.appending("wasmkit"),
+            extraCLIOptions: ["run"]
+        )
+        XCTAssertEqual(wasiWithoutToolsetsDecoded[0].toolset.knownTools[.debugger], wasmKitProperties)
+
+        XCTAssertEqual(wasiWithoutToolsetsDecoded[0].toolset.knownTools[.testRunner], wasmKitProperties)
     }
 
     func testSelectDestination() throws {

Tests/PackageModelTests/ToolsetTests.swift

@@ -222,6 +222,7 @@ final class ToolsetTests: XCTestCase {
 
         let store = SwiftSDKBundleStore(
             swiftSDKsDirectory: "/",
+            hostToolchainBinDir: usrBinTools[.swiftCompiler]!.parentDirectory,
             fileSystem: fileSystem,
             observabilityScope: observability.topScope,
             outputHandler: { _ in }