Add Equatable Instances to Many Incremental Data Structures

The hashable bound on both key and value for many of the maps implies a derivable Equatable instance that we can pick up.

Author: CodaFi

Sources/SwiftDriver/IncrementalCompilation/BidirectionalMap.swift

@@ -11,7 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 /// Like a two-way dictionary, only works for accessing present members
-public struct BidirectionalMap<T1: Hashable, T2: Hashable> {
+public struct BidirectionalMap<T1: Hashable, T2: Hashable>: Equatable {
   private var map1: [T1: T2] = [:]
   private var map2: [T2: T1] = [:]
 

Sources/SwiftDriver/IncrementalCompilation/DictionaryOfDictionaries.swift

@@ -135,3 +135,7 @@ extension DictionaryOfDictionaries {
     return old
   }
 }
+
+// MARK: - identity
+
+ extension DictionaryOfDictionaries: Equatable where Value: Equatable {}

Sources/SwiftDriver/IncrementalCompilation/ModuleDependencyGraphParts/Integrator.swift

@@ -193,8 +193,7 @@ extension ModuleDependencyGraph.Integrator {
     _ sourceFileUseNode: SourceFileDependencyGraph.Node,
     _ moduleUseNode: Graph.Node
   ) {
-    source.forEachDefDependedUpon(by: sourceFileUseNode) {
-      def in
+    source.forEachDefDependedUpon(by: sourceFileUseNode) { def in
       let isNewUse = destination.nodeFinder.record(def: def.key,
                                                    use: moduleUseNode)
       if let externalDependency = def.key.designator.externalDependency,

Sources/SwiftDriver/IncrementalCompilation/ModuleDependencyGraphParts/Node.swift

@@ -68,7 +68,7 @@ extension ModuleDependencyGraph {
 }
 // MARK: - comparing, hashing
 extension ModuleDependencyGraph.Node: Equatable, Hashable {
-  public static func == (lhs: Graph.Node, rhs: Graph.Node ) -> Bool {
+  public static func == (lhs: Graph.Node, rhs: Graph.Node) -> Bool {
     lhs.dependencyKey == rhs.dependencyKey && lhs.fingerprint == rhs.fingerprint
       && lhs.swiftDeps == rhs.swiftDeps
   }

Sources/SwiftDriver/IncrementalCompilation/Multidictionary.swift

@@ -11,7 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 /// Like a Dictionary, but can have >1 value per key (i.e., a multimap)
-struct Multidictionary<Key: Hashable, Value: Hashable>: Collection {
+struct Multidictionary<Key: Hashable, Value: Hashable>: Collection, Equatable {
   public typealias OuterDict = [Key: Set<Value>]
   public typealias InnerSet = Set<Value>
   private var outerDict = OuterDict()

Sources/SwiftDriver/IncrementalCompilation/TwoDMap.swift

@@ -12,7 +12,7 @@
 
 
 /// A map with 2 keys that can iterate in a number of ways
-public struct TwoDMap<Key1: Hashable, Key2: Hashable, Value: Equatable>: MutableCollection {
+public struct TwoDMap<Key1: Hashable, Key2: Hashable, Value: Equatable>: MutableCollection, Equatable {
 
   private var map1 = DictionaryOfDictionaries<Key1, Key2, Value>()
   private var map2 = DictionaryOfDictionaries<Key2, Key1, Value>()