Fix jump-to-definition to methods in swift interfaces that are in synthesized extensions

For example when trying to go-to-definition to `filter` on `Array`, we get a USR `s:s14_ArrayProtocolPsE6filterySay7ElementQzGSbAEKXEKF::SYNTHESIZED::s:Sa`. We were trying to look it up in the index, which failed because synthesized extension methods are not indexed.

Instead, consult the `module` and `groupName` that `sourcekitd` returns in the cursor info request to decide which module to jump to.

rdar://126240558

Author: ahoppen

Sources/LanguageServerProtocol/Requests/OpenInterfaceRequest.swift

@@ -23,27 +23,24 @@ public struct OpenInterfaceRequest: TextDocumentRequest, Hashable {
   public var moduleName: String
 
   /// The module group name.
-  public var groupNames: [String]
+  public var groupName: String?
 
   /// The symbol USR to search for in the generated module interface.
   public var symbolUSR: String?
 
-  public init(textDocument: TextDocumentIdentifier, name: String, symbolUSR: String?) {
+  public init(textDocument: TextDocumentIdentifier, name: String, groupName: String?, symbolUSR: String?) {
     self.textDocument = textDocument
     self.symbolUSR = symbolUSR
-    // Stdlib Swift modules are all in the "Swift" module, but their symbols return a module name `Swift.***`.
-    let splitName = name.split(separator: ".")
-    self.moduleName = String(splitName[0])
-    self.groupNames = [String.SubSequence](splitName.dropFirst()).map(String.init)
+    self.moduleName = name
+    self.groupName = groupName
   }
 
   /// Name of interface module name with group names appended
   public var name: String {
-    if groupNames.count > 0 {
-      return "\(self.moduleName).\(self.groupNames.joined(separator: "."))"
-    } else {
-      return self.moduleName
+    if let groupName {
+      return "\(self.moduleName).\(groupName.replacing("/", with: "."))"
     }
+    return self.moduleName
   }
 }
 

Sources/LanguageServerProtocol/Requests/SymbolInfoRequest.swift

@@ -48,6 +48,18 @@ public struct SymbolInfoRequest: TextDocumentRequest, Hashable {
 /// Detailed information about a symbol, such as the response to a `SymbolInfoRequest`
 /// **(LSP Extension)**.
 public struct SymbolDetails: ResponseType, Hashable {
+  public struct ModuleInfo: Codable, Hashable, Sendable {
+    /// The name of the module in which the symbol is defined.
+    public let moduleName: String
+
+    /// If the symbol is defined within a subgroup of a module, the name of the group. Otherwise `nil`.
+    public let groupName: String?
+
+    public init(moduleName: String, groupName: String? = nil) {
+      self.moduleName = moduleName
+      self.groupName = groupName
+    }
+  }
 
   /// The name of the symbol, if any.
   public var name: String?
@@ -87,6 +99,11 @@ public struct SymbolDetails: ResponseType, Hashable {
   /// Optional because `clangd` does not return whether a symbol is dynamic.
   public var isDynamic: Bool?
 
+  /// Whether this symbol is defined in the SDK or standard library.
+  ///
+  /// This property only applies to Swift symbols.
+  public var isSystem: Bool?
+
   /// If the symbol is dynamic, the USRs of the types that might be called.
   ///
   /// This is relevant in the following cases
@@ -112,21 +129,31 @@ public struct SymbolDetails: ResponseType, Hashable {
   /// `B` may be called dynamically.
   public var receiverUsrs: [String]?
 
+  /// If the symbol is defined in a module that doesn't have source information associated with it, the name and group
+  /// and group name that defines this symbol.
+  ///
+  /// This property only applies to Swift symbols.
+  public var systemModule: ModuleInfo?
+
   public init(
     name: String?,
     containerName: String?,
     usr: String?,
     bestLocalDeclaration: Location?,
     kind: SymbolKind?,
     isDynamic: Bool?,
-    receiverUsrs: [String]?
+    isSystem: Bool?,
+    receiverUsrs: [String]?,
+    systemModule: ModuleInfo?
   ) {
     self.name = name
     self.containerName = containerName
     self.usr = usr
     self.bestLocalDeclaration = bestLocalDeclaration
     self.kind = kind
     self.isDynamic = isDynamic
+    self.isSystem = isSystem
     self.receiverUsrs = receiverUsrs
+    self.systemModule = systemModule
   }
 }

Sources/SourceKitLSP/SourceKitLSPServer.swift

@@ -1842,13 +1842,25 @@ extension SourceKitLSPServer {
     if symbol.kind == .module, let name = symbol.name {
       let interfaceLocation = try await self.definitionInInterface(
         moduleName: name,
+        groupName: nil,
         symbolUSR: nil,
         originatorUri: uri,
         languageService: languageService
       )
       return [interfaceLocation]
     }
 
+    if symbol.isSystem ?? false, let systemModule = symbol.systemModule {
+      let location = try await self.definitionInInterface(
+        moduleName: systemModule.moduleName,
+        groupName: systemModule.groupName,
+        symbolUSR: symbol.usr,
+        originatorUri: uri,
+        languageService: languageService
+      )
+      return [location]
+    }
+
     guard let index = await self.workspaceForDocument(uri: uri)?.index else {
       if let bestLocalDeclaration = symbol.bestLocalDeclaration {
         return [bestLocalDeclaration]
@@ -1891,19 +1903,7 @@ extension SourceKitLSPServer {
       return [bestLocalDeclaration]
     }
 
-    return try await occurrences.asyncCompactMap { occurrence in
-      if URL(fileURLWithPath: occurrence.location.path).pathExtension == "swiftinterface" {
-        // If the location is in `.swiftinterface` file, use moduleName to return textual interface.
-        return try await self.definitionInInterface(
-          moduleName: occurrence.location.moduleName,
-          symbolUSR: occurrence.symbol.usr,
-          originatorUri: uri,
-          languageService: languageService
-        )
-      }
-      return indexToLSPLocation(occurrence.location)
-    }
-    .sorted()
+    return occurrences.compactMap { indexToLSPLocation($0.location) }.sorted()
   }
 
   /// Returns the result of a `DefinitionRequest` by running a `SymbolInfoRequest`, inspecting
@@ -1968,13 +1968,15 @@ extension SourceKitLSPServer {
   /// compiler arguments to generate the generated interface.
   func definitionInInterface(
     moduleName: String,
+    groupName: String?,
     symbolUSR: String?,
     originatorUri: DocumentURI,
     languageService: LanguageService
   ) async throws -> Location {
     let openInterface = OpenInterfaceRequest(
       textDocument: TextDocumentIdentifier(originatorUri),
       name: moduleName,
+      groupName: groupName,
       symbolUSR: symbolUSR
     )
     guard let interfaceDetails = try await languageService.openInterface(openInterface) else {

Sources/SourceKitLSP/Swift/CursorInfo.swift

@@ -65,7 +65,7 @@ struct CursorInfo {
       return nil
     }
 
-    var location: Location? = nil
+    let location: Location?
     if let filepath: String = dict[keys.filePath],
       let line: Int = dict[keys.line],
       let column: Int = dict[keys.column]
@@ -76,6 +76,16 @@ struct CursorInfo {
         utf16index: column - 1
       )
       location = Location(uri: DocumentURI(URL(fileURLWithPath: filepath)), range: Range(position))
+    } else {
+      location = nil
+    }
+
+    let module: SymbolDetails.ModuleInfo?
+    if let moduleName: String = dict[keys.moduleName] {
+      let groupName: String? = dict[keys.groupName]
+      module = SymbolDetails.ModuleInfo(moduleName: moduleName, groupName: groupName)
+    } else {
+      module = nil
     }
 
     self.init(
@@ -86,7 +96,9 @@ struct CursorInfo {
         bestLocalDeclaration: location,
         kind: kind.asSymbolKind(sourcekitd.values),
         isDynamic: dict[keys.isDynamic] ?? false,
-        receiverUsrs: dict[keys.receivers]?.compactMap { $0[keys.usr] as String? } ?? []
+        isSystem: dict[keys.isSystem] ?? false,
+        receiverUsrs: dict[keys.receivers]?.compactMap { $0[keys.usr] as String? } ?? [],
+        systemModule: module
       ),
       annotatedDeclaration: dict[keys.annotatedDecl],
       documentationXML: dict[keys.docFullAsXML],

Sources/SourceKitLSP/Swift/OpenInterface.swift

@@ -73,7 +73,7 @@ extension SwiftLanguageService {
     let skreq = sourcekitd.dictionary([
       keys.request: requests.editorOpenInterface,
       keys.moduleName: name,
-      keys.groupName: request.groupNames.isEmpty ? nil : request.groupNames as [SKDRequestValue],
+      keys.groupName: request.groupName,
       keys.name: interfaceURI.pseudoPath,
       keys.synthesizedExtension: 1,
       keys.compilerArgs: await self.buildSettings(for: uri)?.compilerArgs as [SKDRequestValue]?,

Tests/SourceKitLSPTests/SwiftInterfaceTests.swift

@@ -44,8 +44,7 @@ final class SwiftInterfaceTests: XCTestCase {
       XCTFail("Unexpected response: \(resp)")
       return
     }
-    XCTAssertEqual(locations.count, 1)
-    let location = try XCTUnwrap(locations.first)
+    let location = try XCTUnwrap(locations.only)
     XCTAssertTrue(location.uri.pseudoPath.hasSuffix("/Foundation.swiftinterface"))
     let fileContents = try XCTUnwrap(location.uri.fileURL.flatMap({ try String(contentsOf: $0, encoding: .utf8) }))
     // Sanity-check that the generated Swift Interface contains Swift code
@@ -87,6 +86,7 @@ final class SwiftInterfaceTests: XCTestCase {
     let openInterface = OpenInterfaceRequest(
       textDocument: TextDocumentIdentifier(mainUri),
       name: "MyLibrary",
+      groupName: nil,
       symbolUSR: nil
     )
     let interfaceDetails = try unwrap(await project.testClient.send(openInterface))
@@ -108,38 +108,6 @@ final class SwiftInterfaceTests: XCTestCase {
     )
   }
 
-  /// Used by testDefinitionInSystemModuleInterface
-  private func testSystemSwiftInterface(
-    uri: DocumentURI,
-    position: Position,
-    testClient: TestSourceKitLSPClient,
-    swiftInterfaceFile: String,
-    linePrefix: String,
-    line: UInt = #line
-  ) async throws {
-    let definition = try await testClient.send(
-      DefinitionRequest(
-        textDocument: TextDocumentIdentifier(uri),
-        position: position
-      )
-    )
-    guard case .locations(let jump) = definition else {
-      XCTFail("Response is not locations", line: line)
-      return
-    }
-    let location = try XCTUnwrap(jump.first)
-    XCTAssertTrue(
-      location.uri.pseudoPath.hasSuffix(swiftInterfaceFile),
-      "Path was: '\(location.uri.pseudoPath)'",
-      line: line
-    )
-    // load contents of swiftinterface
-    let contents = try XCTUnwrap(location.uri.fileURL.flatMap({ try String(contentsOf: $0, encoding: .utf8) }))
-    let lineTable = LineTable(contents)
-    let destinationLine = lineTable[location.range.lowerBound.line]
-    XCTAssert(destinationLine.hasPrefix(linePrefix), "Full line was: '\(destinationLine)'", line: line)
-  }
-
   func testDefinitionInSystemModuleInterface() async throws {
     let project = try await IndexedSingleSwiftFileTestProject(
       """
@@ -158,23 +126,23 @@ final class SwiftInterfaceTests: XCTestCase {
     )
 
     // Test stdlib with one submodule
-    try await testSystemSwiftInterface(
+    try await assertSystemSwiftInterface(
       uri: project.fileURI,
       position: project.positions["1️⃣"],
       testClient: project.testClient,
       swiftInterfaceFile: "/Swift.String.swiftinterface",
       linePrefix: "@frozen public struct String"
     )
     // Test stdlib with two submodules
-    try await testSystemSwiftInterface(
+    try await assertSystemSwiftInterface(
       uri: project.fileURI,
       position: project.positions["2️⃣"],
       testClient: project.testClient,
       swiftInterfaceFile: "/Swift.Math.Integers.swiftinterface",
       linePrefix: "@frozen public struct Int"
     )
     // Test concurrency
-    try await testSystemSwiftInterface(
+    try await assertSystemSwiftInterface(
       uri: project.fileURI,
       position: project.positions["3️⃣"],
       testClient: project.testClient,
@@ -224,8 +192,7 @@ final class SwiftInterfaceTests: XCTestCase {
       XCTFail("Unexpected response: \(resp)")
       return
     }
-    XCTAssertEqual(locations.count, 1)
-    let location = try XCTUnwrap(locations.first)
+    let location = try XCTUnwrap(locations.only)
     XCTAssertTrue(location.uri.pseudoPath.hasSuffix("/MyLibrary.swiftinterface"))
     let fileContents = try XCTUnwrap(location.uri.fileURL.flatMap({ try String(contentsOf: $0, encoding: .utf8) }))
     XCTAssertTrue(
@@ -242,4 +209,76 @@ final class SwiftInterfaceTests: XCTestCase {
       "Generated interface did not contain expected text.\n\(fileContents)"
     )
   }
+
+  func testJumpToSynthesizedExtensionMethodInSystemModuleWithoutIndex() async throws {
+    let testClient = try await TestSourceKitLSPClient()
+    let uri = DocumentURI.for(.swift)
+
+    let positions = testClient.openDocument(
+      """
+      func test(x: [String]) {
+        let rows = x.1️⃣filter { !$0.isEmpty }
+      }
+      """,
+      uri: uri
+    )
+
+    try await assertSystemSwiftInterface(
+      uri: uri,
+      position: positions["1️⃣"],
+      testClient: testClient,
+      swiftInterfaceFile: "/Swift.Collection.Array.swiftinterface",
+      linePrefix: "@inlinable public func filter(_ isIncluded: (Element) throws -> Bool) rethrows -> [Element]"
+    )
+  }
+
+  func testJumpToSynthesizedExtensionMethodInSystemModuleWithIndex() async throws {
+    let project = try await IndexedSingleSwiftFileTestProject(
+      """
+      func test(x: [String]) {
+        let rows = x.1️⃣filter { !$0.isEmpty }
+      }
+      """,
+      indexSystemModules: true
+    )
+
+    try await assertSystemSwiftInterface(
+      uri: project.fileURI,
+      position: project.positions["1️⃣"],
+      testClient: project.testClient,
+      swiftInterfaceFile: "/Swift.Collection.Array.swiftinterface",
+      linePrefix: "@inlinable public func filter(_ isIncluded: (Element) throws -> Bool) rethrows -> [Element]"
+    )
+  }
+}
+
+private func assertSystemSwiftInterface(
+  uri: DocumentURI,
+  position: Position,
+  testClient: TestSourceKitLSPClient,
+  swiftInterfaceFile: String,
+  linePrefix: String,
+  line: UInt = #line
+) async throws {
+  let definition = try await testClient.send(
+    DefinitionRequest(
+      textDocument: TextDocumentIdentifier(uri),
+      position: position
+    )
+  )
+  guard case .locations(let jump) = definition else {
+    XCTFail("Response is not locations", line: line)
+    return
+  }
+  let location = try XCTUnwrap(jump.only)
+  XCTAssertTrue(
+    location.uri.pseudoPath.hasSuffix(swiftInterfaceFile),
+    "Path was: '\(location.uri.pseudoPath)'",
+    line: line
+  )
+  // load contents of swiftinterface
+  let contents = try XCTUnwrap(location.uri.fileURL.flatMap({ try String(contentsOf: $0, encoding: .utf8) }))
+  let lineTable = LineTable(contents)
+  let destinationLine = lineTable[location.range.lowerBound.line].trimmingCharacters(in: .whitespaces)
+  XCTAssert(destinationLine.hasPrefix(linePrefix), "Full line was: '\(destinationLine)'", line: line)
 }