Change logging to use OSLog

CMakeLists.txt

@@ -22,6 +22,7 @@ find_package(ArgumentParser CONFIG REQUIRED)
 find_package(SwiftCollections QUIET)
 find_package(SwiftSystem CONFIG REQUIRED)
 find_package(SwiftSyntax CONFIG REQUIRED) 
+find_package(SwiftCrypto CONFIG REQUIRED)
 
 include(SwiftSupport)
 

Package.swift

@@ -166,14 +166,17 @@ let package = Package(
     // Logging support used in LSP modules.
     .target(
       name: "LSPLogging",
-      dependencies: [],
+      dependencies: [
+        .product(name: "Crypto", package: "swift-crypto")
+      ],
       exclude: ["CMakeLists.txt"]
     ),
 
     .testTarget(
       name: "LSPLoggingTests",
       dependencies: [
-        "LSPLogging"
+        "LSPLogging",
+        "SKTestSupport",
       ]
     ),
 
@@ -207,7 +210,8 @@ let package = Package(
     .target(
       name: "LanguageServerProtocol",
       dependencies: [
-        .product(name: "SwiftToolsSupport-auto", package: "swift-tools-support-core")
+        "LSPLogging",
+        .product(name: "SwiftToolsSupport-auto", package: "swift-tools-support-core"),
       ],
       exclude: ["CMakeLists.txt"]
     ),
@@ -266,6 +270,7 @@ if ProcessInfo.processInfo.environment["SWIFTCI_USE_LOCAL_DEPS"] == nil {
     .package(url: "https://github.com/apple/swift-tools-support-core.git", branch: relatedDependenciesBranch),
     .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.2.2"),
     .package(url: "https://github.com/apple/swift-syntax.git", branch: relatedDependenciesBranch),
+    .package(url: "https://github.com/apple/swift-crypto.git", from: "2.5.0"),
   ]
 } else {
   package.dependencies += [
@@ -274,5 +279,6 @@ if ProcessInfo.processInfo.environment["SWIFTCI_USE_LOCAL_DEPS"] == nil {
     .package(path: "../swift-tools-support-core"),
     .package(path: "../swift-argument-parser"),
     .package(path: "../swift-syntax"),
+    .package(path: "../swift-crypto"),
   ]
 }

Sources/LSPLogging/CMakeLists.txt

@@ -1,7 +1,17 @@
 add_library(LSPLogging STATIC
-  LogLevel.swift
-  Logging.swift)
+  CustomLogStringConvertible.swift
+  Error+ForLogging.swift
+  Logging.swift
+  LoggingScope.swift
+  NonDarwinLogging.swift
+  OrLog.swift
+)
 set_target_properties(LSPLogging PROPERTIES
   INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_Swift_MODULE_DIRECTORY})
 target_link_libraries(LSPLogging PRIVATE
-  $<$<NOT:$<PLATFORM_ID:Darwin>>:Foundation>)
+  $<$<NOT:$<PLATFORM_ID:Darwin>>:Foundation>
+)
+
+target_link_libraries(LSPLogging PUBLIC
+  Crypto
+)

Sources/LSPLogging/CustomLogStringConvertible.swift

@@ -0,0 +1,64 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2023 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 Crypto
+import Foundation
+
+/// An object that can printed for logging and also offers a redacted description
+/// when logging in contexts in which private information shouldn't be captured.
+public protocol CustomLogStringConvertible: CustomStringConvertible {
+  /// A full description of the object.
+  var description: String { get }
+
+  /// A description of the object that doesn't contain any private information.
+  var redactedDescription: String { get }
+}
+
+/// When an NSObject is logged with OSLog in private mode and the object
+/// implements `redactedDescription`, OSLog will log that information instead of
+/// just logging `<private>`.
+///
+/// There currently is no way to get equivalent functionality in pure Swift. We
+/// thus pass this object to OSLog, which just forwards to `description` or
+/// `redactedDescription` of an object that implements `CustomLogStringConvertible`.
+public class CustomLogStringConvertibleWrapper: NSObject {
+  private let underlyingObject: any CustomLogStringConvertible
+
+  fileprivate init(_ underlyingObject: any CustomLogStringConvertible) {
+    self.underlyingObject = underlyingObject
+  }
+
+  public override var description: String {
+    return underlyingObject.description
+  }
+
+  public var redactedDescription: String {
+    underlyingObject.redactedDescription
+  }
+}
+
+extension CustomLogStringConvertible {
+  /// Returns an object that can be passed to OSLog, which will print the
+  /// `redactedDescription` if logging of private information is disabled and
+  /// will log `description` otherwise.
+  public var forLogging: CustomLogStringConvertibleWrapper {
+    return CustomLogStringConvertibleWrapper(self)
+  }
+}
+
+extension String {
+  /// A hash value that can be logged in a redacted description without
+  /// disclosing any private information about the string.
+  public var hashForLogging: String {
+    return Insecure.MD5.hash(data: Data(self.utf8)).description
+  }
+}

Sources/LSPLogging/Error+ForLogging.swift

@@ -0,0 +1,43 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2023 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
+
+/// A wrapper around `Error` that conforms to `CustomLogStringConvertible`.
+private struct MaskedError: CustomLogStringConvertible {
+  let underlyingError: any Error
+
+  init(_ underlyingError: any Error) {
+    self.underlyingError = underlyingError
+  }
+
+  var description: String {
+    return "\(underlyingError)"
+  }
+
+  var redactedDescription: String {
+    let error = underlyingError as NSError
+    return "\(error.code): \(error.description.hashForLogging)"
+  }
+}
+
+extension Error {
+  /// A version of the error that can be used for logging and will only log the
+  /// error code and a hash of the description in privacy-sensitive contexts.
+  public var forLogging: CustomLogStringConvertibleWrapper {
+    if let error = self as? CustomLogStringConvertible {
+      return error.forLogging
+    } else {
+      return MaskedError(self).forLogging
+    }
+  }
+}