Log the options with which SourceKit-LSP is launched

Sources/SKLogging/CustomLogStringConvertible.swift

@@ -85,3 +85,55 @@ extension Optional where Wrapped: CustomLogStringConvertible {
     return CustomLogStringConvertibleWrapper(OptionalWrapper(optional: self))
   }
 }
+
+/// A JSON-like description of the object.
+public func recursiveDescription(of subject: Any) -> String {
+  return "{"
+    + Mirror(reflecting: subject).children.map { (key, value) in
+      "\(key ?? "<nil>"): \(String(describing: value))"
+    }.joined(separator: ", ")
+    + "}"
+}
+
+fileprivate protocol OptionalProtocol {
+  associatedtype Wrapped
+  var asOptional: Wrapped? { get }
+}
+extension Optional: OptionalProtocol {
+  var asOptional: Wrapped? { self }
+}
+
+/// A JSON-like description of the object that shows trivial values but redacts values that might contain sensitive
+/// information.
+public func recursiveRedactedDescription(of value: Any) -> String {
+  switch value {
+  case let value as Bool:
+    return value.description
+  case let value as Int:
+    return value.description
+  case let value as Double:
+    return value.description
+  case let value as String:
+    return value.hashForLogging
+  case let value as any CustomLogStringConvertible:
+    return value.redactedDescription
+  case let value as any OptionalProtocol:
+    if let value = value.asOptional {
+      return recursiveRedactedDescription(of: value)
+    } else {
+      return "nil"
+    }
+  default:
+    break
+  }
+
+  let children = Mirror(reflecting: value).children.sorted { $0.label ?? "" < $1.label ?? "" }
+  if !children.isEmpty {
+    return "{"
+      + children.map { (label, value) -> String in
+        "\(label ?? "<nil>"): \(recursiveRedactedDescription(of: value))"
+      }.joined(separator: ", ")
+      + "}"
+  }
+  return "<private>"
+}

Sources/SKOptions/SourceKitLSPOptions.swift

@@ -20,8 +20,8 @@ import struct TSCBasic.AbsolutePath
 /// Options that can be used to modify SourceKit-LSP's behavior.
 ///
 /// See `ConfigurationFile.md` for a description of the configuration file's behavior.
-public struct SourceKitLSPOptions: Sendable, Codable {
-  public struct SwiftPMOptions: Sendable, Codable {
+public struct SourceKitLSPOptions: Sendable, Codable, CustomLogStringConvertible {
+  public struct SwiftPMOptions: Sendable, Codable, CustomLogStringConvertible {
     /// Build configuration (debug|release).
     ///
     /// Equivalent to SwiftPM's `--configuration` option.
@@ -88,9 +88,17 @@ public struct SourceKitLSPOptions: Sendable, Codable {
         linkerFlags: override?.linkerFlags ?? base.linkerFlags
       )
     }
+
+    public var description: String {
+      recursiveDescription(of: self)
+    }
+
+    public var redactedDescription: String {
+      recursiveRedactedDescription(of: self)
+    }
   }
 
-  public struct CompilationDatabaseOptions: Sendable, Codable {
+  public struct CompilationDatabaseOptions: Sendable, Codable, CustomLogStringConvertible {
     /// Additional paths to search for a compilation database, relative to a workspace root.
     public var searchPaths: [String]?
 
@@ -104,9 +112,17 @@ public struct SourceKitLSPOptions: Sendable, Codable {
     ) -> CompilationDatabaseOptions {
       return CompilationDatabaseOptions(searchPaths: override?.searchPaths ?? base.searchPaths)
     }
+
+    public var description: String {
+      recursiveDescription(of: self)
+    }
+
+    public var redactedDescription: String {
+      recursiveRedactedDescription(of: self)
+    }
   }
 
-  public struct FallbackBuildSystemOptions: Sendable, Codable {
+  public struct FallbackBuildSystemOptions: Sendable, Codable, CustomLogStringConvertible {
     public var cCompilerFlags: [String]?
     public var cxxCompilerFlags: [String]?
     public var swiftCompilerFlags: [String]?
@@ -131,9 +147,17 @@ public struct SourceKitLSPOptions: Sendable, Codable {
         swiftCompilerFlags: override?.swiftCompilerFlags ?? base.swiftCompilerFlags
       )
     }
+
+    public var description: String {
+      recursiveDescription(of: self)
+    }
+
+    public var redactedDescription: String {
+      recursiveRedactedDescription(of: self)
+    }
   }
 
-  public struct IndexOptions: Sendable, Codable {
+  public struct IndexOptions: Sendable, Codable, CustomLogStringConvertible {
     public var indexStorePath: String?
     public var indexDatabasePath: String?
     public var indexPrefixMap: [String: String]?
@@ -176,6 +200,14 @@ public struct SourceKitLSPOptions: Sendable, Codable {
         updateIndexStoreTimeout: override?.updateIndexStoreTimeout ?? base.updateIndexStoreTimeout
       )
     }
+
+    public var description: String {
+      recursiveDescription(of: self)
+    }
+
+    public var redactedDescription: String {
+      recursiveRedactedDescription(of: self)
+    }
   }
 
   public enum BackgroundPreparationMode: String {
@@ -392,4 +424,12 @@ public struct SourceKitLSPOptions: Sendable, Codable {
       forKey: CodingKeys.workDoneProgressDebounceDuration
     )
   }
+
+  public var description: String {
+    recursiveDescription(of: self)
+  }
+
+  public var redactedDescription: String {
+    recursiveRedactedDescription(of: self)
+  }
 }

Sources/SourceKitLSP/SourceKitLSPServer.swift

@@ -897,6 +897,7 @@ extension SourceKitLSPServer {
           .appendingPathComponent("config.json")
       )
     )
+    logger.log("Creating workspace at \(workspaceFolder.uri.forLogging) with options: \(options.forLogging)")
     let buildSystem = await createBuildSystem(
       rootUri: workspaceFolder.uri,
       options: options,
@@ -998,6 +999,8 @@ extension SourceKitLSPServer {
       override: orLog("Parsing SourceKitLSPOptions", { try SourceKitLSPOptions(fromLSPAny: req.initializationOptions) })
     )
 
+    logger.log("Initialized SourceKit-LSP with options: \(self.options.forLogging)")
+
     await workspaceQueue.async { [testHooks] in
       if let workspaceFolders = req.workspaceFolders {
         self.workspacesAndIsImplicit += await workspaceFolders.asyncCompactMap {

Tests/SKLoggingTests/LoggingTests.swift

@@ -212,4 +212,30 @@ final class LoggingTests: XCTestCase {
       $0.log("got \(LogStringConvertible().forLogging)")
     }
   }
+
+  func testRecursiveRedactedDescription() {
+    struct Outer {
+      struct Inner {
+        var publicValue: Int
+        var redactedValue: String
+      }
+      var inner: Inner
+    }
+
+    XCTAssertEqual(
+      recursiveRedactedDescription(of: Outer(inner: Outer.Inner(publicValue: 42, redactedValue: "password"))),
+      """
+      {inner: {publicValue: 42, redactedValue: MD5 digest: 5f4dcc3b5aa765d61d8327deb882cf99}}
+      """
+    )
+
+    XCTAssertEqual(recursiveRedactedDescription(of: (nil as Int?) as Any), "nil")
+
+    XCTAssertEqual(recursiveRedactedDescription(of: (42 as Int?) as Any), "42")
+
+    XCTAssertEqual(
+      recursiveRedactedDescription(of: ("abc" as String?) as Any),
+      "MD5 digest: 900150983cd24fb0d6963f7d28e17f72"
+    )
+  }
 }