Add workspace/symbols support

https://bugs.swift.org/browse/SR-10806

Author: literalpie

Sources/LanguageServerProtocol/Messages.swift

@@ -23,6 +23,7 @@ public let builtinRequests: [_RequestType.Type] = [
   WorkspaceFoldersRequest.self,
   CompletionRequest.self,
   HoverRequest.self,
+  WorkspaceSymbolsRequest.self,
   DefinitionRequest.self,
   ReferencesRequest.self,
   DocumentHighlightRequest.self,

Sources/LanguageServerProtocol/ServerCapabilities.swift

@@ -51,6 +51,9 @@ public struct ServerCapabilities: Codable, Hashable {
   /// Whether the server provides "textDocument/codeAction".
   public var codeActionProvider: CodeActionServerCapabilities?
 
+  /// The server provides workspace symbol support.
+  public var workspaceSymbolProvider: Bool?
+
   // TODO: fill-in the rest.
 
   public init(
@@ -66,7 +69,8 @@ public struct ServerCapabilities: Codable, Hashable {
     foldingRangeProvider: Bool? = nil,
     documentSymbolProvider: Bool? = nil,
     colorProvider: Bool? = nil,
-    codeActionProvider: CodeActionServerCapabilities? = nil
+    codeActionProvider: CodeActionServerCapabilities? = nil,
+    workspaceSymbolProvider: Bool? = nil
     )
   {
     self.textDocumentSync = textDocumentSync
@@ -82,6 +86,7 @@ public struct ServerCapabilities: Codable, Hashable {
     self.documentSymbolProvider = documentSymbolProvider
     self.colorProvider = colorProvider
     self.codeActionProvider = codeActionProvider
+    self.workspaceSymbolProvider = workspaceSymbolProvider
   }
 
   public init(from decoder: Decoder) throws {
@@ -93,6 +98,7 @@ public struct ServerCapabilities: Codable, Hashable {
     self.documentSymbolProvider = try container.decodeIfPresent(Bool.self, forKey: .documentSymbolProvider)
     self.colorProvider = try container.decodeIfPresent(Bool.self, forKey: .colorProvider)
     self.codeActionProvider = try container.decodeIfPresent(CodeActionServerCapabilities.self, forKey: .codeActionProvider)
+    self.workspaceSymbolProvider = try container.decodeIfPresent(Bool.self, forKey: .workspaceSymbolProvider)
 
     if let textDocumentSync = try? container.decode(TextDocumentSyncOptions.self, forKey: .textDocumentSync) {
       self.textDocumentSync = textDocumentSync

Sources/LanguageServerProtocol/WorkspaceSymbols.swift

@@ -0,0 +1,55 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2018 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 for all symbols that match a certain query string.
+///
+/// This request looks up the canonical occurence of each symbol which has a name that contains the query string.
+/// The list of symbol information is returned
+///
+/// Servers that provide workspace symbol queries should set the `workspaceSymbolProvider` server capability.
+///
+/// - Parameters:
+///   - query: The string that should be looked for in symbols of the workspace.
+///
+/// - Returns: Information about each symbol with a name that contains the query string
+public struct WorkspaceSymbolsRequest: RequestType, Hashable {
+
+  public static let method: String = "workspace/symbol"
+  public typealias Response = [SymbolInformation]?
+
+  /// The document in which to lookup the symbol location.
+  public var query: String
+
+  public init(query: String) {
+    self.query = query
+  }
+}
+
+public struct SymbolInformation: Hashable, ResponseType {
+  public var name: String
+
+  public var kind: SymbolKind
+
+  public var deprecated: Bool
+
+  public var location: Location
+
+  public var containerName: String?
+
+  public init(name: String, kind: SymbolKind, deprecated: Bool, location: Location, containerName: String?) {
+    self.name = name
+    self.kind = kind
+    self.deprecated = deprecated
+    self.location = location
+    self.containerName = containerName
+  }
+}

Sources/SourceKit/SourceKitServer.swift

@@ -71,6 +71,7 @@ public final class SourceKitServer: LanguageServer {
     registerWorkspaceNotfication(SourceKitServer.didSaveDocument)
     registerWorkspaceRequest(SourceKitServer.completion)
     registerWorkspaceRequest(SourceKitServer.hover)
+    registerWorkspaceRequest(SourceKitServer.workspaceSymbols)
     registerWorkspaceRequest(SourceKitServer.definition)
     registerWorkspaceRequest(SourceKitServer.references)
     registerWorkspaceRequest(SourceKitServer.documentSymbolHighlight)
@@ -269,7 +270,8 @@ extension SourceKitServer {
         clientCapabilities: req.params.capabilities.textDocument?.codeAction,
         codeActionOptions: CodeActionOptions(codeActionKinds: nil),
         supportsCodeActions: false // TODO: Turn it on after a provider is implemented.
-      )
+      ),
+      workspaceSymbolProvider: true
     )))
   }
 
@@ -338,6 +340,51 @@ extension SourceKitServer {
     toolchainTextDocumentRequest(req, workspace: workspace, fallback: nil)
   }
 
+  /// Find all symbols in the workspace that include a string in their name.
+  /// - returns: An array of SymbolOccurrences that match the string.
+  func findWorkspaceSymbols(matching: String) -> [SymbolOccurrence] {
+    var symbolOccurenceResults: [SymbolOccurrence] = []
+    workspace?.index?.forEachCanonicalSymbolOccurrence(
+      containing: matching,
+      anchorStart: false,
+      anchorEnd: false,
+      subsequence: true,
+      ignoreCase: true
+    ) {symbol in
+      if !symbol.location.isSystem && !symbol.roles.contains(.accessorOf) {
+        symbolOccurenceResults.append(symbol)
+      }
+      return true
+    }
+    return symbolOccurenceResults
+  }
+
+  /// Handle a workspace/symbols request, returning the SymbolInformation.
+  /// - returns: An array with SymbolInformation for each matching symbol in the workspace.
+  func workspaceSymbols(_ req: Request<WorkspaceSymbolsRequest>, workspace: Workspace) {
+    let symbols = findWorkspaceSymbols(
+      matching: req.params.query
+    ).map({symbolOccurrence -> SymbolInformation in
+      let symbolPosition = Position(
+        line: symbolOccurrence.location.line - 1, // 1-based -> 0-based
+        // FIXME: we need to convert the utf8/utf16 column, which may require reading the file!
+        utf16index: symbolOccurrence.location.utf8Column - 1)
+
+      let symbolLocation = Location(
+        url: URL(fileURLWithPath: symbolOccurrence.location.path),
+        range: Range(symbolPosition))
+
+      return SymbolInformation(
+        name: symbolOccurrence.symbol.name,
+        kind: symbolOccurrence.symbol.kind.toLspSymbolKind(),
+        deprecated: false,
+        location: symbolLocation,
+        containerName: symbolOccurrence.getContainerName()
+      )
+    })
+    req.reply(symbols)
+  }
+
   /// Forwards a SymbolInfoRequest to the appropriate toolchain service for this document.
   func symbolInfo(_ req: Request<SymbolInfoRequest>, workspace: Workspace) {
     toolchainTextDocumentRequest(req, workspace: workspace, fallback: [])
@@ -523,3 +570,54 @@ public func languageService(
 
 public typealias Notification = LanguageServerProtocol.Notification
 public typealias Diagnostic = LanguageServerProtocol.Diagnostic
+
+extension IndexSymbolKind {
+  func toLspSymbolKind() -> SymbolKind {
+    switch self {
+    case Self.class:
+      return .class
+    case Self.classMethod,
+      Self.instanceMethod,
+      Self.staticMethod:
+      return .method
+    case Self.instanceProperty,
+      Self.staticProperty,
+      Self.classProperty:
+      return .property
+    case Self.enum:
+      return .enum
+    case Self.enumConstant: // Unsure about this one
+      return .enumMember
+    case Self.protocol:
+      return .interface
+    case Self.function,
+      Self.conversionFunction: // assuming conversion function is function
+      return .function
+    case Self.variable:
+      return .variable
+    case Self.struct:
+      return .struct
+    case Self.parameter:
+      return .typeParameter
+    case Self.parameter:
+      return .typeParameter
+
+    default:
+      return .null
+    }
+  }
+}
+
+extension SymbolOccurrence {
+  /// Get the name of the symbol that is a parent of this symbol, if one exists
+  func getContainerName() -> String? {
+    var foundChildRelation: SymbolRelation?
+    self.forEachRelation { relation in
+      if relation.roles.contains(.childOf) {
+        foundChildRelation = relation
+      }
+      return false
+    }
+    return foundChildRelation?.symbol.name
+  }
+}

Tests/LanguageServerProtocolJSONRPCTests/CodingTests.swift

@@ -85,7 +85,8 @@ final class CodingTests: XCTestCase {
       referencesProvider: nil,
       documentHighlightProvider: nil,
       foldingRangeProvider: nil,
-      codeActionProvider: nil)), id: .number(2), json: """
+      codeActionProvider: nil,
+      workspaceSymbolProvider: nil)), id: .number(2), json: """
     {
       "id" : 2,
       "jsonrpc" : "2.0",