Pass through the toolchain to use for manifest loading

Sources/PackageLoading/ManifestLoader.swift

@@ -289,7 +289,6 @@ public final class ManifestLoader: ManifestLoaderProtocol {
     public var delegate: Delegate?
 
     private let databaseCacheDir: AbsolutePath?
-    private let sdkRootCache = ThreadSafeBox<AbsolutePath>()
 
     private let useInMemoryCache: Bool
     private let memoryCache = ThreadSafeKeyValueStore<CacheKey, ManifestJSONParser.Result>()
@@ -1114,35 +1113,12 @@ public final class ManifestLoader: ManifestLoaderProtocol {
         }
     }
 
-    /// Returns path to the sdk, if possible.
-    private func sdkRoot() -> AbsolutePath? {
-        if let sdkRoot = self.sdkRootCache.get() {
-            return sdkRoot
-        }
-
-        var sdkRootPath: AbsolutePath? = nil
-        // Find SDKROOT on macOS using xcrun.
-        #if os(macOS)
-        let foundPath = try? AsyncProcess.checkNonZeroExit(
-            args: "/usr/bin/xcrun", "--sdk", "macosx", "--show-sdk-path")
-        guard let sdkRoot = foundPath?.spm_chomp(), !sdkRoot.isEmpty else {
-            return nil
-        }
-        if let path = try? AbsolutePath(validating: sdkRoot) {
-            sdkRootPath = path
-            self.sdkRootCache.put(path)
-        }
-        #endif
-
-        return sdkRootPath
-    }
-
-    /// Returns the interpreter flags for a manifest.
-    public func interpreterFlags(
-        for toolsVersion: ToolsVersion
+    package static func interpreterFlags(
+        for toolsVersion: ToolsVersion,
+        toolchain: some Toolchain
     ) -> [String] {
         var cmd = [String]()
-        let modulesPath = self.toolchain.swiftPMLibrariesLocation.manifestModulesPath
+        let modulesPath = toolchain.swiftPMLibrariesLocation.manifestModulesPath
         cmd += ["-swift-version", toolsVersion.swiftLanguageVersion.rawValue]
         // if runtimePath is set to "PackageFrameworks" that means we could be developing SwiftPM in Xcode
         // which produces a framework for dynamic package products.
@@ -1152,14 +1128,21 @@ public final class ManifestLoader: ManifestLoaderProtocol {
             cmd += ["-I", modulesPath.pathString]
         }
       #if os(macOS)
-        if let sdkRoot = self.toolchain.sdkRootPath ?? self.sdkRoot() {
+        if let sdkRoot = toolchain.sdkRootPath {
             cmd += ["-sdk", sdkRoot.pathString]
         }
       #endif
         cmd += ["-package-description-version", toolsVersion.description]
         return cmd
     }
 
+    /// Returns the interpreter flags for a manifest.
+    public func interpreterFlags(
+        for toolsVersion: ToolsVersion
+    ) -> [String] {
+        return Self.interpreterFlags(for: toolsVersion, toolchain: toolchain)
+    }
+
     /// Returns path to the manifest database inside the given cache directory.
     private static func manifestCacheDBPath(_ cacheDir: AbsolutePath) -> AbsolutePath {
         return cacheDir.appending("manifest.db")

Sources/PackageModel/Toolchain.swift

@@ -43,6 +43,9 @@ public protocol Toolchain {
     /// The root path to the Swift SDK used by this toolchain.
     var sdkRootPath: AbsolutePath? { get }
 
+    /// The manifest and library locations used by this toolchain.
+    var swiftPMLibrariesLocation: ToolchainConfiguration.SwiftPMLibrariesLocation { get }
+
     /// Path of the `clang` compiler.
     func getClangCompiler() throws -> AbsolutePath
 

Sources/SourceKitLSPAPI/BuildDescription.swift

@@ -24,6 +24,7 @@ import class Build.SwiftModuleBuildDescription
 import struct PackageGraph.ResolvedModule
 import struct PackageGraph.ModulesGraph
 import enum PackageGraph.BuildTriple
+internal import class PackageModel.UserToolchain
 
 public typealias BuildTriple = PackageGraph.BuildTriple
 
@@ -133,6 +134,7 @@ public struct BuildDescription {
                 return PluginTargetBuildDescription(
                     target: target,
                     toolsVersion: package.manifest.toolsVersion,
+                    toolchain: buildPlan.toolsBuildParameters.toolchain,
                     isPartOfRootPackage: modulesGraph.rootPackages.map(\.id).contains(package.id)
                 )
             }

Sources/SourceKitLSPAPI/PluginTargetBuildDescription.swift

@@ -18,18 +18,20 @@ import struct PackageGraph.ResolvedModule
 
 private import class PackageLoading.ManifestLoader
 internal import struct PackageModel.ToolsVersion
-internal import class PackageModel.UserToolchain
+internal import protocol PackageModel.Toolchain
 import enum PackageGraph.BuildTriple
 
 struct PluginTargetBuildDescription: BuildTarget {
     private let target: ResolvedModule
     private let toolsVersion: ToolsVersion
+    private let toolchain: any Toolchain
     let isPartOfRootPackage: Bool
 
-    init(target: ResolvedModule, toolsVersion: ToolsVersion, isPartOfRootPackage: Bool) {
+    init(target: ResolvedModule, toolsVersion: ToolsVersion, toolchain: any Toolchain, isPartOfRootPackage: Bool) {
         assert(target.type == .plugin)
         self.target = target
         self.toolsVersion = toolsVersion
+        self.toolchain = toolchain
         self.isPartOfRootPackage = isPartOfRootPackage
     }
 
@@ -47,16 +49,7 @@ struct PluginTargetBuildDescription: BuildTarget {
 
     func compileArguments(for fileURL: URL) throws -> [String] {
         // FIXME: This is very odd and we should clean this up by merging `ManifestLoader` and `DefaultPluginScriptRunner` again.
-        let environment = Environment.current
-        let loader = ManifestLoader(
-            toolchain: try UserToolchain(
-                swiftSDK: .hostSwiftSDK(
-                    environment: environment
-                ),
-                environment: environment
-            )
-        )
-        var args = loader.interpreterFlags(for: self.toolsVersion)
+        var args = ManifestLoader.interpreterFlags(for: self.toolsVersion, toolchain: toolchain)
         // Note: we ignore the `fileURL` here as the expectation is that we get a commandline for the entire target in case of Swift. Plugins are always assumed to only consist of Swift files.
         args += sources.map { $0.path }
         return args

Sources/_InternalTestSupport/MockBuildTestHelper.swift

@@ -40,6 +40,9 @@ public struct MockToolchain: PackageModel.Toolchain {
     public let extraFlags = PackageModel.BuildFlags()
     public let installedSwiftPMConfiguration = InstalledSwiftPMConfiguration.default
     public let providedLibraries = [ProvidedLibrary]()
+    public let swiftPMLibrariesLocation = ToolchainConfiguration.SwiftPMLibrariesLocation(
+        manifestLibraryPath: AbsolutePath("/fake/manifestLib/path"), pluginLibraryPath: AbsolutePath("/fake/pluginLibrary/path")
+    )
 
     public func getClangCompiler() throws -> AbsolutePath {
         "/fake/path/to/clang"

Tests/SourceKitLSPAPITests/SourceKitLSPAPITests.swift

@@ -25,7 +25,8 @@ final class SourceKitLSPAPITests: XCTestCase {
     func testBasicSwiftPackage() throws {
         let fs = InMemoryFileSystem(emptyFiles:
             "/Pkg/Sources/exe/main.swift",
-            "/Pkg/Sources/lib/lib.swift"
+            "/Pkg/Sources/lib/lib.swift",
+            "/Pkg/Plugins/plugin/plugin.swift"
         )
 
         let observability = ObservabilitySystem.makeForTesting()
@@ -38,6 +39,7 @@ final class SourceKitLSPAPITests: XCTestCase {
                     targets: [
                         TargetDescription(name: "exe", dependencies: ["lib"]),
                         TargetDescription(name: "lib", dependencies: []),
+                        TargetDescription(name: "plugin", type: .plugin, pluginCapability: .buildTool)
                     ]),
             ],
             observabilityScope: observability.topScope
@@ -81,6 +83,15 @@ final class SourceKitLSPAPITests: XCTestCase {
             ],
             isPartOfRootPackage: true
         )
+        try description.checkArguments(
+            for: "plugin",
+            graph: graph,
+            partialArguments: [
+                "-I", "/fake/manifestLib/path"
+            ],
+            isPartOfRootPackage: true,
+            destination: .tools
+        )
     }
 }
 
@@ -89,9 +100,10 @@ extension SourceKitLSPAPI.BuildDescription {
         for targetName: String,
         graph: ModulesGraph,
         partialArguments: [String],
-        isPartOfRootPackage: Bool
+        isPartOfRootPackage: Bool,
+        destination: BuildTriple = .destination
     ) throws -> Bool {
-        let target = try XCTUnwrap(graph.module(for: targetName, destination: .destination))
+        let target = try XCTUnwrap(graph.module(for: targetName, destination: destination))
         let buildTarget = try XCTUnwrap(self.getBuildTarget(for: target, in: graph))
 
         guard let file = buildTarget.sources.first else {