Pass through the toolchain to use for manifest loading

Prefer the toolchain provided in the build plan rather than the default
host toolchain so that the returned arguments align with the toolchain
used to construct the build plan.

Author: bnbarham

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 {