State-of-the-art implementation via swift-build

Author: khlopko

Package.resolved

@@ -15,6 +15,7 @@ let package = Package(
         .package(url: "https://github.com/apple/swift-log", from: "1.6.0"),
         .package(url: "https://github.com/apple/swift-argument-parser", from: "1.3.0"),
         .package(url: "https://github.com/stephencelis/SQLite.swift.git", from: "0.15.4"),
+        .package(url: "https://github.com/khlopko/swift-build.git", branch: "xcode-bsp"),
     ],
     targets: [
         .executableTarget(
@@ -23,6 +24,8 @@ let package = Package(
                 .product(name: "Logging", package: "swift-log"),
                 .product(name: "ArgumentParser", package: "swift-argument-parser"),
                 .product(name: "SQLite", package: "SQLite.swift"),
+                .product(name: "SwiftBuild", package: "swift-build"),
+                .product(name: "SWBBuildService", package: "swift-build"),
             ]
         ),
         .testTarget(

Package.swift

@@ -49,6 +49,9 @@ struct XcodeBSPApp: ParsableCommand {
                 }
             }
 
+            let workspaceContainerPath = try resolveConfiguredWorkspaceContainerPath()
+            print("Using workspace container: \(workspaceContainerPath)")
+
             let executablePath = try resolveConfiguredExecutablePath()
             print("Using executable path: \(executablePath)")
 
@@ -76,16 +79,25 @@ struct XcodeBSPApp: ParsableCommand {
                 version: "0.2.0",
                 bspVersion: "2.0.0",
                 languages: ["swift", "objective-c", "objective-cpp"],
-                activeSchemes: activeSchemes
+                activeSchemes: activeSchemes,
+                buildBackend: .swiftBuild,
+                workspaceContainerPath: workspaceContainerPath
             )
             let encoder = JSONEncoder()
             encoder.outputFormatting = .withoutEscapingSlashes
             let data = try encoder.encode(config)
             FileManager.default.createFile(atPath: configPath, contents: data)
             print("Saved BSP config to \(configPath)")
         case .server:
-            let server = try XcodeBuildServer(cacheDir: cacheDir)
-            server.run()
+            let config = try FileConfigProvider().load(decoder: JSONDecoder())
+            switch config.buildBackend {
+            case .swiftBuild:
+                let server = try SwiftBuildServerBackend(cacheDir: cacheDir, config: config)
+                try server.run()
+            case .xcodeBuild:
+                let server = try XcodeBuildServer(cacheDir: cacheDir)
+                server.run()
+            }
         }
     }
 }
@@ -130,6 +142,63 @@ private extension XcodeBSPApp {
         return "/usr/local/bin/xcode-bsp"
     }
 
+    func resolveConfiguredWorkspaceContainerPath(fileManager: FileManager = .default) throws -> String {
+        let candidates = try workspaceContainerCandidates(fileManager: fileManager)
+        guard candidates.isEmpty == false else {
+            throw ValidationError(
+                "No .xcworkspace or .xcodeproj found in the current directory. " +
+                "Run `xcode-bsp config` from a project root."
+            )
+        }
+
+        if candidates.count == 1 {
+            return candidates[0]
+        }
+
+        print("Choose workspace container for SwiftBuild:")
+        for (index, candidate) in candidates.enumerated() {
+            print("[\(index + 1)] \(candidate)")
+        }
+
+        print("Selection [1]", terminator: " ")
+        let input = (readLine() ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
+        if input.isEmpty {
+            return candidates[0]
+        }
+
+        guard let selectedIndex = Int(input), candidates.indices.contains(selectedIndex - 1) else {
+            throw ValidationError("Invalid container selection: \(input)")
+        }
+
+        return candidates[selectedIndex - 1]
+    }
+
+    func workspaceContainerCandidates(fileManager: FileManager) throws -> [String] {
+        let cwd = URL(filePath: fileManager.currentDirectoryPath)
+        let contents = try fileManager.contentsOfDirectory(
+            at: cwd,
+            includingPropertiesForKeys: [.isDirectoryKey],
+            options: [.skipsHiddenFiles]
+        )
+
+        let candidates = contents.compactMap { url -> String? in
+            let pathExtension = url.pathExtension.lowercased()
+            guard pathExtension == "xcworkspace" || pathExtension == "xcodeproj" else {
+                return nil
+            }
+            return url.lastPathComponent
+        }
+
+        return candidates.sorted { lhs, rhs in
+            let lhsIsWorkspace = lhs.lowercased().hasSuffix(".xcworkspace")
+            let rhsIsWorkspace = rhs.lowercased().hasSuffix(".xcworkspace")
+            if lhsIsWorkspace != rhsIsWorkspace {
+                return lhsIsWorkspace
+            }
+            return lhs.localizedStandardCompare(rhs) == .orderedAscending
+        }
+    }
+
     func resolveExecutableCandidate(_ value: String, fileManager: FileManager) -> String? {
         guard value.contains("/") else {
             return nil

Sources/XcodeBSP/App.swift

@@ -58,6 +58,16 @@ extension TextDocumentSourceKitOptions: MethodHandler {
         let candidateTargets = cachedSnapshot.targetsByFilePath[filePath]
             ?? cachedSnapshot.targetsByFilePath[resolvedFilePath]
             ?? []
+        logger.debug(
+            """
+            sourceKitOptions args cache miss \
+            request id=\(request.id) \
+            target=\(targetURI) \
+            filePath=\(filePath) \
+            resolvedFilePath=\(resolvedFilePath) \
+            candidateTargets=\(candidateTargets.count)
+            """
+        )
         logger.trace(
             """
             sourceKitOptions request id=\(request.id) cache miss for target=\(targetURI), refreshing \

Sources/XcodeBSP/BuildServerProtocol/Handlers/TextDocumentSourceKitOptions.swift

@@ -1,12 +1,19 @@
 import Foundation
 
+enum BuildBackend: String, Codable, Sendable {
+    case swiftBuild = "swiftbuild"
+    case xcodeBuild = "xcodebuild"
+}
+
 struct Config {
     let name: String
     let argv: [String]
     let version: String
     let bspVersion: String
     let languages: [String]
     let activeSchemes: [String]
+    let buildBackend: BuildBackend
+    let workspaceContainerPath: String?
 }
 
 extension Config: Codable {
@@ -17,6 +24,8 @@ extension Config: Codable {
         case bspVersion
         case languages
         case activeSchemes
+        case buildBackend
+        case workspaceContainerPath
     }
 
     init(from decoder: any Decoder) throws {
@@ -27,6 +36,8 @@ extension Config: Codable {
         bspVersion = try container.decode(String.self, forKey: .bspVersion)
         languages = try container.decode([String].self, forKey: .languages)
         activeSchemes = try container.decodeIfPresent([String].self, forKey: .activeSchemes) ?? []
+        buildBackend = try container.decodeIfPresent(BuildBackend.self, forKey: .buildBackend) ?? .swiftBuild
+        workspaceContainerPath = try container.decodeIfPresent(String.self, forKey: .workspaceContainerPath)
     }
 }
 

Sources/XcodeBSP/Config.swift

@@ -52,7 +52,7 @@ func shell(_ command: String, output: URL? = nil) throws -> ShellOutput {
     task.launchPath = "/bin/sh"
     task.standardInput = nil
 
-    task.launch()
+    try task.run()
 
     task.waitUntilExit()