Add LSP support for showing Macro Expansions

Sources/LanguageServerProtocol/CMakeLists.txt

@@ -73,6 +73,7 @@ add_library(LanguageServerProtocol STATIC
   Requests/RegisterCapabilityRequest.swift
   Requests/RenameRequest.swift
   Requests/SelectionRangeRequest.swift
+  Requests/ShowDocumentRequest.swift
   Requests/ShowMessageRequest.swift
   Requests/ShutdownRequest.swift
   Requests/SignatureHelpRequest.swift

Sources/LanguageServerProtocol/Messages.swift

@@ -65,6 +65,7 @@ public let builtinRequests: [_RequestType.Type] = [
   RegisterCapabilityRequest.self,
   RenameRequest.self,
   SelectionRangeRequest.self,
+  ShowDocumentRequest.self,
   ShowMessageRequest.self,
   ShutdownRequest.self,
   SignatureHelpRequest.self,

Sources/LanguageServerProtocol/Requests/ShowDocumentRequest.swift

@@ -0,0 +1,52 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+/// Request from the server to the client to show a document on the client
+/// side.
+public struct ShowDocumentRequest: RequestType {
+  public static let method: String = "window/showDocument"
+  public typealias Response = ShowDocumentResponse
+
+  /// The uri to show.
+  public var uri: DocumentURI
+
+  /// An optional boolean indicates to show the resource in an external
+  /// program. To show, for example, `https://www.swift.org/ in the default WEB
+  /// browser set `external` to `true`.
+  public var external: Bool?
+
+  /// An optional boolean to indicate whether the editor showing the document
+  /// should take focus or not. Clients might ignore this property if an
+  /// external program is started.
+  public var takeFocus: Bool?
+
+  /// An optional selection range if the document is a text document. Clients
+  /// might ignore the property if an external program is started or the file
+  /// is not a text file.
+  public var selection: Range<Position>?
+
+  public init(uri: DocumentURI, external: Bool? = nil, takeFocus: Bool? = nil, selection: Range<Position>? = nil) {
+    self.uri = uri
+    self.external = external
+    self.takeFocus = takeFocus
+    self.selection = selection
+  }
+}
+
+public struct ShowDocumentResponse: Codable, Hashable, ResponseType {
+  /// A boolean indicating if the show was successful.
+  public var success: Bool
+
+  public init(success: Bool) {
+    self.success = success
+  }
+}

Sources/SKCore/ExperimentalFeatures.swift

@@ -18,4 +18,7 @@ public enum ExperimentalFeature: String, Codable, Sendable, CaseIterable {
 
   /// Add `--experimental-prepare-for-indexing` to the `swift build` command run to prepare a target for indexing.
   case swiftpmPrepareForIndexing = "swiftpm-prepare-for-indexing"
+
+  /// Enable showing macro expansions via `ShowDocumentRequest`
+  case showMacroExpansions = "show-macro-expansions"
 }

Sources/SKSupport/FileSystem.swift

@@ -31,7 +31,8 @@ extension AbsolutePath {
   }
 }
 
-/// The directory to write generated module interfaces
-public var defaultDirectoryForGeneratedInterfaces: AbsolutePath {
-  try! AbsolutePath(validating: NSTemporaryDirectory()).appending(component: "GeneratedInterfaces")
+/// The default directory to write generated files
+/// `<TEMPORARY_DIRECTORY>/sourcekit-lsp/`
+public var defaultDirectoryForGeneratedFiles: AbsolutePath {
+  try! AbsolutePath(validating: NSTemporaryDirectory()).appending(component: "sourcekit-lsp")
 }

Sources/SourceKitLSP/CMakeLists.txt

@@ -40,8 +40,13 @@ target_sources(SourceKitLSP PRIVATE
   Swift/DiagnosticReportManager.swift
   Swift/DocumentFormatting.swift
   Swift/DocumentSymbols.swift
+  Swift/ExpandMacroCommand.swift
   Swift/FoldingRange.swift
+  Swift/MacroExpansion.swift
   Swift/OpenInterface.swift
+  Swift/Refactoring.swift
+  Swift/RefactoringEdit.swift
+  Swift/RefactorCommand.swift
   Swift/RelatedIdentifiers.swift
   Swift/RewriteSourceKitPlaceholders.swift
   Swift/SemanticRefactorCommand.swift

Sources/SourceKitLSP/SourceKitLSPServer+Options.swift

@@ -38,8 +38,20 @@ extension SourceKitLSPServer {
     /// Options for code-completion.
     public var completionOptions: SKCompletionOptions
 
-    /// Override the default directory where generated interfaces will be stored
-    public var generatedInterfacesPath: AbsolutePath
+    /// Override the default directory where generated files will be stored
+    public var generatedFilesPath: AbsolutePath
+
+    /// Path to the generated interfaces
+    /// `<generatedFilesPath>/GeneratedInterfaces/`
+    public var generatedInterfacesPath: AbsolutePath {
+      generatedFilesPath.appending(component: "GeneratedInterfaces")
+    }
+
+    /// Path to the generated macro expansions
+    /// `<generatedFilesPath>`/GeneratedMacroExpansions/
+    public var generatedMacroExpansionsPath: AbsolutePath {
+      generatedFilesPath.appending(component: "GeneratedMacroExpansions")
+    }
 
     /// The time that `SwiftLanguageService` should wait after an edit before starting to compute diagnostics and
     /// sending a `PublishDiagnosticsNotification`.
@@ -64,7 +76,7 @@ extension SourceKitLSPServer {
       compilationDatabaseSearchPaths: [RelativePath] = [],
       indexOptions: IndexOptions = .init(),
       completionOptions: SKCompletionOptions = .init(),
-      generatedInterfacesPath: AbsolutePath = defaultDirectoryForGeneratedInterfaces,
+      generatedFilesPath: AbsolutePath = defaultDirectoryForGeneratedFiles,
       swiftPublishDiagnosticsDebounceDuration: TimeInterval = 2, /* 2s */
       workDoneProgressDebounceDuration: Duration = .seconds(0),
       experimentalFeatures: Set<ExperimentalFeature> = [],
@@ -75,7 +87,7 @@ extension SourceKitLSPServer {
       self.compilationDatabaseSearchPaths = compilationDatabaseSearchPaths
       self.indexOptions = indexOptions
       self.completionOptions = completionOptions
-      self.generatedInterfacesPath = generatedInterfacesPath
+      self.generatedFilesPath = generatedFilesPath
       self.swiftPublishDiagnosticsDebounceDuration = swiftPublishDiagnosticsDebounceDuration
       self.experimentalFeatures = experimentalFeatures
       self.workDoneProgressDebounceDuration = workDoneProgressDebounceDuration

Sources/SourceKitLSP/Swift/ExpandMacroCommand.swift

@@ -0,0 +1,80 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import LanguageServerProtocol
+import SourceKitD
+
+public struct ExpandMacroCommand: RefactorCommand {
+  typealias Response = MacroExpansion
+
+  public static let identifier: String = "expand.macro.command"
+
+  /// The name of this refactoring action.
+  public var title = "Expand Macro"
+
+  /// The sourcekitd identifier of the refactoring action.
+  public var actionString = "source.refactoring.kind.expand.macro"
+
+  /// The range to expand.
+  public var positionRange: Range<Position>
+
+  /// The text document related to the refactoring action.
+  public var textDocument: TextDocumentIdentifier
+
+  public init(positionRange: Range<Position>, textDocument: TextDocumentIdentifier) {
+    self.positionRange = positionRange
+    self.textDocument = textDocument
+  }
+
+  public init?(fromLSPDictionary dictionary: [String: LSPAny]) {
+    guard case .dictionary(let documentDict)? = dictionary[CodingKeys.textDocument.stringValue],
+      case .string(let title)? = dictionary[CodingKeys.title.stringValue],
+      case .string(let actionString)? = dictionary[CodingKeys.actionString.stringValue],
+      case .dictionary(let rangeDict)? = dictionary[CodingKeys.positionRange.stringValue]
+    else {
+      return nil
+    }
+    guard let positionRange = Range<Position>(fromLSPDictionary: rangeDict),
+      let textDocument = TextDocumentIdentifier(fromLSPDictionary: documentDict)
+    else {
+      return nil
+    }
+
+    self.init(
+      title: title,
+      actionString: actionString,
+      positionRange: positionRange,
+      textDocument: textDocument
+    )
+  }
+
+  public init(
+    title: String,
+    actionString: String,
+    positionRange: Range<Position>,
+    textDocument: TextDocumentIdentifier
+  ) {
+    self.title = title
+    self.actionString = actionString
+    self.positionRange = positionRange
+    self.textDocument = textDocument
+  }
+
+  public func encodeToLSPAny() -> LSPAny {
+    return .dictionary([
+      CodingKeys.title.stringValue: .string(title),
+      CodingKeys.actionString.stringValue: .string(actionString),
+      CodingKeys.positionRange.stringValue: positionRange.encodeToLSPAny(),
+      CodingKeys.textDocument.stringValue: textDocument.encodeToLSPAny(),
+    ])
+  }
+}

Sources/SourceKitLSP/Swift/MacroExpansion.swift

@@ -0,0 +1,132 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import Foundation
+import LSPLogging
+import LanguageServerProtocol
+import SourceKitD
+
+/// Detailed information about the result of a macro expansion operation.
+///
+/// Wraps the information returned by sourcekitd's `semantic_refactoring`
+/// request, such as the necessary macro expansion edits.
+struct MacroExpansion: RefactoringResponse {
+  /// The title of the refactoring action.
+  var title: String
+
+  /// The URI of the file where the macro is used
+  var uri: DocumentURI
+
+  /// The resulting array of `RefactoringEdit` of a semantic refactoring request
+  var edits: [RefactoringEdit]
+
+  init(title: String, uri: DocumentURI, refactoringEdits: [RefactoringEdit]) {
+    self.title = title
+    self.uri = uri
+    self.edits = refactoringEdits.compactMap { refactoringEdit in
+      if refactoringEdit.bufferName == nil && !refactoringEdit.newText.isEmpty {
+        logger.fault("Unable to retrieve some parts of the expansion")
+        return nil
+      }
+
+      return refactoringEdit
+    }
+  }
+}
+
+extension SwiftLanguageService {
+  /// Handles the `ExpandMacroCommand`.
+  ///
+  /// Makes a request to sourcekitd and wraps the result into a `MacroExpansion`
+  /// and then makes a `ShowDocumentRequest` to the client side for each
+  /// expansion to be displayed.
+  ///
+  /// - Parameters:
+  ///   - expandMacroCommand: The `ExpandMacroCommand` that triggered this request.
+  ///
+  /// - Returns: A `[RefactoringEdit]` with the necessary edits and buffer name as a `LSPAny`
+  func expandMacro(
+    _ expandMacroCommand: ExpandMacroCommand
+  ) async throws -> LSPAny {
+    guard let sourceKitLSPServer else {
+      // `SourceKitLSPServer` has been destructed. We are tearing down the
+      // language server. Nothing left to do.
+      throw ResponseError.unknown("Connection to the editor closed")
+    }
+
+    guard let sourceFileURL = expandMacroCommand.textDocument.uri.fileURL else {
+      throw ResponseError.unknown("Given URI is not a file URL")
+    }
+
+    let expansion = try await self.refactoring(expandMacroCommand)
+
+    for macroEdit in expansion.edits {
+      if let bufferName = macroEdit.bufferName {
+        // buffer name without ".swift"
+        let macroExpansionBufferDirectoryName =
+          bufferName.hasSuffix(".swift")
+          ? String(bufferName.dropLast(6))
+          : bufferName
+
+        let macroExpansionBufferDirectoryURL = self.generatedMacroExpansionsPath
+          .appendingPathComponent(macroExpansionBufferDirectoryName)
+        do {
+          try FileManager.default.createDirectory(
+            at: macroExpansionBufferDirectoryURL,
+            withIntermediateDirectories: true
+          )
+        } catch {
+          throw ResponseError.unknown(
+            "Failed to create directory for macro expansion buffer at path: \(macroExpansionBufferDirectoryURL.path)"
+          )
+        }
+
+        // name of the source file
+        let macroExpansionFileName = sourceFileURL.deletingPathExtension().lastPathComponent
+
+        // github permalink notation for position range
+        let macroExpansionPositionRangeIndicator =
+          "L\(macroEdit.range.lowerBound.line)C\(macroEdit.range.lowerBound.utf16index)-L\(macroEdit.range.upperBound.line)C\(macroEdit.range.upperBound.utf16index)"
+
+        let macroExpansionFilePath =
+          macroExpansionBufferDirectoryURL
+          .appendingPathComponent(
+            "\(macroExpansionFileName)_\(macroExpansionPositionRangeIndicator).\(sourceFileURL.pathExtension)"
+          )
+
+        do {
+          try macroEdit.newText.write(to: macroExpansionFilePath, atomically: true, encoding: .utf8)
+        } catch {
+          throw ResponseError.unknown(
+            "Unable to write macro expansion to file path: \"\(macroExpansionFilePath.path)\""
+          )
+        }
+
+        Task {
+          let req = ShowDocumentRequest(uri: DocumentURI(macroExpansionFilePath), selection: macroEdit.range)
+
+          let response = await orLog("Sending ShowDocumentRequest to Client") {
+            try await sourceKitLSPServer.sendRequestToClient(req)
+          }
+
+          if let response, !response.success {
+            logger.error("client refused to show document for \(expansion.title, privacy: .public)")
+          }
+        }
+      } else if !macroEdit.newText.isEmpty {
+        logger.fault("Unable to retrieve some parts of macro expansion")
+      }
+    }
+
+    return expansion.edits.encodeToLSPAny()
+  }
+}

Sources/SourceKitLSP/Swift/RefactorCommand.swift

@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import LanguageServerProtocol
+import SourceKitD
+
+/// A protocol to be utilised by all commands that are served by sourcekitd refactorings.
+protocol RefactorCommand: SwiftCommand {
+  /// The response type of the refactor command
+  associatedtype Response: RefactoringResponse
+
+  /// The sourcekitd identifier of the refactoring action.
+  var actionString: String { get set }
+
+  /// The range to refactor.
+  var positionRange: Range<Position> { get set }
+
+  /// The text document related to the refactoring action.
+  var textDocument: TextDocumentIdentifier { get set }
+
+  init(title: String, actionString: String, positionRange: Range<Position>, textDocument: TextDocumentIdentifier)
+}