Add a BSP implementation for packages to be adopted by sourcekit-lsp

owenv · owenv · commit 05cf77ed6f86 · 2025-12-03T12:48:48.000-08:00
diff --git a/Fixtures/Miscellaneous/VersionSpecificManifest/Foo.swift b/Fixtures/Miscellaneous/VersionSpecificManifest/Foo.swift
@@ -0,0 +1,3 @@
+public func foo() {
+	{}()
+}
diff --git a/Fixtures/Miscellaneous/VersionSpecificManifest/Package.swift b/Fixtures/Miscellaneous/VersionSpecificManifest/Package.swift
@@ -0,0 +1,12 @@
+// swift-tools-version:6.0
+import PackageDescription
+
+let package = Package(
+    name: "Foo",
+    products: [
+        .library(name: "Foo", targets: ["Foo"]),
+    ],
+    targets: [
+        .target(name: "Foo", path: "./"),
+    ]
+)
diff --git a/Fixtures/Miscellaneous/VersionSpecificManifest/Package@swift-5.0.swift b/Fixtures/Miscellaneous/VersionSpecificManifest/Package@swift-5.0.swift
@@ -0,0 +1,12 @@
+// swift-tools-version:5.2
+import PackageDescription
+
+let package = Package(
+    name: "Foo",
+    products: [
+        .library(name: "Foo", targets: ["Foo"]),
+    ],
+    targets: [
+        .target(name: "Foo", path: "./"),
+    ]
+)
diff --git a/Package.swift b/Package.swift
@@ -105,12 +105,14 @@ let swiftDriverDeps: [Target.Dependency]
 let swiftTSCBasicsDeps: [Target.Dependency]
 let swiftToolsCoreSupportAutoDeps: [Target.Dependency]
 let swiftTSCTestSupportDeps: [Target.Dependency]
+let swiftToolsProtocolsDeps: [Target.Dependency]
 
 if shouldUseSwiftBuildFramework {
     swiftDriverDeps = []
     swiftTSCBasicsDeps = []
     swiftToolsCoreSupportAutoDeps = []
     swiftTSCTestSupportDeps = []
+    swiftToolsProtocolsDeps = []
 } else {
     swiftDriverDeps = [
         .product(name: "SwiftDriver", package: "swift-driver")
@@ -124,6 +126,11 @@ if shouldUseSwiftBuildFramework {
     swiftTSCTestSupportDeps = [
         .product(name: "TSCTestSupport", package: "swift-tools-support-core"),
     ]
+    swiftToolsProtocolsDeps = [
+        .product(name: "BuildServerProtocol", package: "swift-tools-protocols", condition: .when(platforms: [.macOS, .linux, .windows, .android, .openbsd, .custom("freebsd")])),
+        .product(name: "LanguageServerProtocol", package: "swift-tools-protocols", condition: .when(platforms: [.macOS, .linux, .windows, .android, .openbsd, .custom("freebsd")])),
+        .product(name: "LanguageServerProtocolTransport", package: "swift-tools-protocols", condition: .when(platforms: [.macOS, .linux, .windows, .android, .openbsd, .custom("freebsd")])),
+    ]
 }
 let package = Package(
     name: "SwiftPM",
@@ -547,6 +554,23 @@ let package = Package(
             ]
         ),
 
+        // MARK: BSP
+        .target(
+            name: "SwiftPMBuildServer",
+            dependencies: [
+                "Basics",
+                "Build",
+                "PackageGraph",
+                "PackageLoading",
+                "PackageModel",
+                "SPMBuildCore",
+                "SourceControl",
+                "SourceKitLSPAPI",
+                "SwiftBuildSupport",
+                "Workspace"
+            ] + swiftTSCBasicsDeps + swiftToolsProtocolsDeps
+        ),
+
         // MARK: Commands
 
         .target(
@@ -575,6 +599,7 @@ let package = Package(
             dependencies: [
                 .product(name: "ArgumentParser", package: "swift-argument-parser"),
                 .product(name: "OrderedCollections", package: "swift-collections"),
+                .product(name: "SystemPackage", package: "swift-system"),
                 "Basics",
                 "BinarySymbols",
                 "Build",
@@ -585,6 +610,7 @@ let package = Package(
                 "XCBuildSupport",
                 "SwiftBuildSupport",
                 "SwiftFixIt",
+                "SwiftPMBuildServer",
             ] + swiftSyntaxDependencies(["SwiftIDEUtils", "SwiftRefactor"]),
             exclude: ["CMakeLists.txt", "README.md"],
             swiftSettings: swift6CompatibleExperimentalFeatures + [
@@ -1055,6 +1081,13 @@ if ProcessInfo.processInfo.environment["SWIFTCI_DISABLE_SDK_DEPENDENT_TESTS"] ==
                 "dummy-swiftc",
             ]
         ),
+        .testTarget(
+            name: "SwiftPMBuildServerTests",
+            dependencies: [
+                "SwiftPMBuildServer",
+                "_InternalTestSupport",
+            ] + swiftToolsProtocolsDeps
+        ),
     ])
 }
 
@@ -1151,7 +1184,7 @@ if ProcessInfo.processInfo.environment["ENABLE_APPLE_PRODUCT_TYPES"] == "1" {
 
 if !shouldUseSwiftBuildFramework {
 
-    let swiftbuildsupport: Target = package.targets.first(where: { $0.name == "SwiftBuildSupport" } )!
+    let swiftbuildsupport: Target = package.targets.first(where: { ["SwiftBuildSupport", "SwiftPMBuildServer", "SwiftPMBuildServerTests"].contains($0.name) } )!
     swiftbuildsupport.dependencies += [
         .product(name: "SwiftBuild", package: "swift-build"),
     ]
@@ -1164,10 +1197,12 @@ if !shouldUseSwiftBuildFramework {
     if ProcessInfo.processInfo.environment["SWIFTCI_USE_LOCAL_DEPS"] == nil {
         package.dependencies += [
             .package(url: "https://github.com/swiftlang/swift-build.git", branch: relatedDependenciesBranch),
+            .package(url: "https://github.com/swiftlang/swift-tools-protocols.git", .upToNextMinor(from: "0.0.9")),
         ]
     } else {
         package.dependencies += [
             .package(path: "../swift-build"),
+            .package(path: "../swift-tools-protocols"),
         ]
     }
 }
diff --git a/Sources/CMakeLists.txt b/Sources/CMakeLists.txt
@@ -40,6 +40,7 @@ add_subdirectory(swift-sdk)
 add_subdirectory(swift-package)
 add_subdirectory(swift-run)
 add_subdirectory(swift-test)
+add_subdirectory(SwiftPMBuildServer)
 add_subdirectory(SwiftSDKCommand)
 add_subdirectory(Workspace)
 add_subdirectory(XCBuildSupport)
diff --git a/Sources/Commands/CMakeLists.txt b/Sources/Commands/CMakeLists.txt
@@ -15,6 +15,7 @@ add_library(Commands
   PackageCommands/APIDiff.swift
   PackageCommands/ArchiveSource.swift
   PackageCommands/AuditBinaryArtifact.swift
+  PackageCommands/BuildServer.swift
   PackageCommands/CompletionCommand.swift
   PackageCommands/ComputeChecksum.swift
   PackageCommands/Config.swift
@@ -61,6 +62,7 @@ add_library(Commands
 target_link_libraries(Commands PUBLIC
   SwiftCollections::OrderedCollections
   SwiftSyntax::SwiftRefactor
+  SwiftSystem::SystemPackage
   ArgumentParser
   Basics
   BinarySymbols
@@ -70,6 +72,7 @@ target_link_libraries(Commands PUBLIC
   PackageGraph
   SourceControl
   SwiftFixIt
+  SwiftPMBuildServer
   TSCBasic
   TSCUtility
   Workspace
diff --git a/Sources/Commands/PackageCommands/BuildServer.swift b/Sources/Commands/PackageCommands/BuildServer.swift
@@ -0,0 +1,74 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+#if canImport(LanguageServerProtocolTransport)
+import ArgumentParser
+import TSCBasic
+import SwiftBuild
+import BuildServerProtocol
+import LanguageServerProtocol
+import LanguageServerProtocolTransport
+import CoreCommands
+import Foundation
+import PackageGraph
+import SwiftPMBuildServer
+import SPMBuildCore
+import SwiftBuildSupport
+import SystemPackage
+
+struct BuildServer: AsyncSwiftCommand {
+    static let configuration = CommandConfiguration(
+        commandName: "experimental-build-server",
+        abstract: "Launch a build server for Swift Packages",
+        shouldDisplay: false
+    )
+
+    @OptionGroup(visibility: .hidden)
+    var globalOptions: GlobalOptions
+
+    func run(_ swiftCommandState: SwiftCommandState) async throws {
+        // Dup stdout and redirect the fd to stderr so that a careless print()
+        // will not break our connection stream.
+        let realStdout = try FileDescriptor.standardOutput.duplicate()
+        _ = try FileDescriptor.standardError.duplicate(as: FileDescriptor.standardOutput)
+
+        let realStdoutHandle = FileHandle(fileDescriptor: realStdout.rawValue, closeOnDealloc: false)
+
+        let clientConnection = JSONRPCConnection(
+            name: "client",
+            protocol: MessageRegistry.bspProtocol,
+            inFD: FileHandle.standardInput,
+            outFD: realStdoutHandle,
+            inputMirrorFile: nil,
+            outputMirrorFile: nil
+        )
+
+        guard let buildSystem = try await swiftCommandState.createBuildSystem() as? SwiftBuildSystem else {
+            throw ArgumentParser.ValidationError("Build server requires --build-system swiftbuild")
+        }
+
+        guard let packagePath = try swiftCommandState.getWorkspaceRoot().packages.first else {
+            throw ArgumentParser.ValidationError("unknown package")
+        }
+
+        let server = try await SwiftPMBuildServer(
+            packageRoot: packagePath,
+            buildSystem: buildSystem,
+            workspace: swiftCommandState.getActiveWorkspace(),
+            connectionToClient: clientConnection,
+            exitHandler: {_ in clientConnection.close() }
+        )
+        await withCheckedContinuation {continuation in
+            clientConnection.start(receiveHandler: server, closeHandler: { continuation.resume() })
+        }
+    }
+}
+#endif
diff --git a/Sources/Commands/PackageCommands/SwiftPackageCommand.swift b/Sources/Commands/PackageCommands/SwiftPackageCommand.swift
@@ -26,13 +26,9 @@ import enum TSCUtility.Diagnostics
 
 /// swift-package tool namespace
 public struct SwiftPackageCommand: AsyncParsableCommand {
-    public static var configuration = CommandConfiguration(
-        commandName: "package",
-        _superCommandName: "swift",
-        abstract: "Perform operations on Swift packages.",
-        discussion: "SEE ALSO: swift build, swift run, swift test \n(Run this command without --help to see possible dynamic plugin commands.)",
-        version: SwiftVersion.current.completeDisplayString,
-        subcommands: [
+
+    private static var subcommands: [any ParsableCommand.Type] = {
+        var subcommands: [any ParsableCommand.Type] = [
             AddDependency.self,
             AddProduct.self,
             AddTarget.self,
@@ -75,7 +71,22 @@ public struct SwiftPackageCommand: AsyncParsableCommand {
 
             DefaultCommand.self,
         ]
-            + (ProcessInfo.processInfo.environment["SWIFTPM_ENABLE_SNIPPETS"] == "1" ? [Learn.self] : []),
+        if ProcessInfo.processInfo.environment["SWIFTPM_ENABLE_SNIPPETS"] == "1" {
+            subcommands.append(Learn.self)
+        }
+        #if canImport(LanguageServerProtocol)
+        subcommands.append(BuildServer.self)
+        #endif
+        return subcommands
+    }()
+
+    public static var configuration = CommandConfiguration(
+        commandName: "package",
+        _superCommandName: "swift",
+        abstract: "Perform operations on Swift packages.",
+        discussion: "SEE ALSO: swift build, swift run, swift test \n(Run this command without --help to see possible dynamic plugin commands.)",
+        version: SwiftVersion.current.completeDisplayString,
+        subcommands: Self.subcommands,
         defaultSubcommand: DefaultCommand.self,
         helpNames: []
     )
diff --git a/Sources/SwiftBuildSupport/SwiftBuildSystem.swift b/Sources/SwiftBuildSupport/SwiftBuildSystem.swift
@@ -111,7 +111,9 @@ func withSession(
     }
 }
 
-private final class PlanningOperationDelegate: SWBPlanningOperationDelegate, Sendable {
+package final class SwiftBuildSystemPlanningOperationDelegate: SWBPlanningOperationDelegate, SWBIndexingDelegate, Sendable {
+    package init() {}
+    
     public func provisioningTaskInputs(
         targetGUID: String,
         provisioningSourceData: SWBProvisioningTaskInputsSourceData
@@ -175,7 +177,7 @@ private final class PlanningOperationDelegate: SWBPlanningOperationDelegate, Sen
 }
 
 public final class SwiftBuildSystem: SPMBuildCore.BuildSystem {
-    private let buildParameters: BuildParameters
+    package let buildParameters: BuildParameters
     private let packageGraphLoader: () async throws -> ModulesGraph
     private let packageManagerResourcesDirectory: Basics.AbsolutePath?
     private let logLevel: Basics.Diagnostic.Severity
@@ -341,7 +343,7 @@ public final class SwiftBuildSystem: SPMBuildCore.BuildSystem {
             return result
         }
 
-        try await writePIF(buildParameters: buildParameters)
+        try await writePIF(buildParameters: self.buildParameters)
 
         return try await startSWBuildOperation(
             pifTargetName: subset.pifTargetName,
@@ -726,7 +728,7 @@ public final class SwiftBuildSystem: SPMBuildCore.BuildSystem {
 
                     let operation = try await session.createBuildOperation(
                         request: request,
-                        delegate: PlanningOperationDelegate(),
+                        delegate: SwiftBuildSystemPlanningOperationDelegate(),
                         retainBuildDescription: true
                     )
 
@@ -1171,18 +1173,43 @@ public final class SwiftBuildSystem: SPMBuildCore.BuildSystem {
     }
 
     public func generatePIF(preserveStructure: Bool) async throws -> String {
-        return try await getPIFBuilder().generatePIF(
+        pifBuilder = .init()
+        packageGraph = .init()
+        let pifBuilder = try await getPIFBuilder()
+        let pif = try await pifBuilder.generatePIF(
             preservePIFModelStructure: preserveStructure,
             printPIFManifestGraphviz: buildParameters.printPIFManifestGraphviz,
             buildParameters: buildParameters
         )
+        return pif
     }
 
     public func writePIF(buildParameters: BuildParameters) async throws {
         let pif = try await generatePIF(preserveStructure: false)
         try self.fileSystem.writeIfChanged(path: buildParameters.pifManifest, string: pif)
     }
 
+    package struct LongLivedBuildServiceSession {
+        package var session: SWBBuildServiceSession
+        package var diagnostics: [SwiftBuildMessage.DiagnosticInfo]
+        package var teardownHandler: () async throws -> Void
+    }
+
+    package func createLongLivedSession(name: String) async throws -> LongLivedBuildServiceSession {
+        let service = try await SWBBuildService(connectionMode: .inProcessStatic(swiftbuildServiceEntryPoint))
+        do {
+            let (session, diagnostics) = try await createSession(service: service, name: name, toolchainPath: buildParameters.toolchain.toolchainDir, packageManagerResourcesDirectory: packageManagerResourcesDirectory)
+            let teardownHandler = {
+                try await session.close()
+                await service.close()
+            }
+            return LongLivedBuildServiceSession(session: session, diagnostics: diagnostics, teardownHandler: teardownHandler)
+        } catch {
+            await service.close()
+            throw error
+        }
+    }
+
     public func cancel(deadline: DispatchTime) throws {}
 
     /// Returns the package graph using the graph loader closure.
diff --git a/Sources/SwiftPMBuildServer/CMakeLists.txt b/Sources/SwiftPMBuildServer/CMakeLists.txt
@@ -0,0 +1,35 @@
+# This source file is part of the Swift open source project
+#
+# Copyright (c) 2025 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See http://swift.org/LICENSE.txt for license information
+# See http://swift.org/CONTRIBUTORS.txt for Swift project authors
+
+add_library(SwiftPMBuildServer STATIC
+  DisableSigpipe.swift
+  SwiftPMBuildServer.swift)
+target_link_libraries(SwiftPMBuildServer PUBLIC
+  Basics
+  Build
+  PackageGraph
+  PackageLoading
+  PackageModel
+  SPMBuildCore
+  SourceControl
+  SourceKitLSPAPI
+  SwiftBuildSupport
+  Workspace
+
+  SwiftBuild::SwiftBuild
+
+  SwiftToolsProtocols::ToolsProtocolsSwiftExtensions
+  SwiftToolsProtocols::BuildServerProtocol
+  SwiftToolsProtocols::LanguageServerProtocol
+  SwiftToolsProtocols::LanguageServerProtocolTransport
+
+  TSCBasic)
+
+# NOTE(compnerd) workaround for CMake not setting up include flags yet
+set_target_properties(SwiftPMBuildServer PROPERTIES
+  INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_Swift_MODULE_DIRECTORY})
diff --git a/Sources/SwiftPMBuildServer/DisableSigpipe.swift b/Sources/SwiftPMBuildServer/DisableSigpipe.swift
diff --git a/Sources/SwiftPMBuildServer/SwiftPMBuildServer.swift b/Sources/SwiftPMBuildServer/SwiftPMBuildServer.swift
diff --git a/Tests/SwiftPMBuildServerTests/BuildServerTests.swift b/Tests/SwiftPMBuildServerTests/BuildServerTests.swift

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+public func foo() {`
	`2`	`+ {}()`
	`3`	`+}`