[Feature] Add new IndexStore indexer variant (#67)

Author: kateinoigakukun

Package.resolved

@@ -17,6 +17,7 @@ let package = Package(
         .package(url: "https://github.com/kylef/PathKit", from: "1.0.0"),
         .package(name: "SwiftSyntax", url: "https://github.com/apple/swift-syntax", .exact("0.50200.0")),
         .package(url: "https://github.com/apple/swift-argument-parser", .upToNextMinor(from: "0.0.4")),
+        .package(url: "https://github.com/apple/swift-tools-support-core.git", .branch("master")),
     ],
     targets: [
         .target(
@@ -32,6 +33,7 @@ let package = Package(
                 .product(name: "PathKit", package: "PathKit"),
                 .product(name: "SwiftSyntax", package: "SwiftSyntax"),
                 .product(name: "ArgumentParser", package: "swift-argument-parser"),
+                .product(name: "SwiftToolsSupport-auto", package: "swift-tools-support-core"),
             ]
         ),
         .testTarget(

Package.swift

@@ -16,6 +16,23 @@ final class UnreadSimplePropertyReferenceEliminator: SourceGraphVisitor {
         self.configuration = configuration
     }
 
+    func transformToGetterUsr(fromMangledSetterUsr usr: String) -> String {
+        var usr = usr
+        assert(usr.last == "s")
+        usr.removeLast()
+        usr.append("g")
+        return usr
+    }
+
+    func transformToPropertyUsr(fromMangledSetterUsr usr: String) -> String {
+        var usr = usr
+        assert(usr.last == "s")
+        usr.removeLast()
+        usr.append("p")
+        return usr
+    }
+
+
     func visit() {
         guard configuration.aggressive else { return }
 
@@ -25,16 +42,32 @@ final class UnreadSimplePropertyReferenceEliminator: SourceGraphVisitor {
             let references = graph.references(to: setter)
 
             for reference in references {
-                // Parent should be a reference to a simple property.
-                guard let propertyReference = reference.parent as? Reference,
-                    let property = graph.declaration(withUsr: propertyReference.usr),
-                    !property.isComplexProperty else { continue }
-
-                // If the property reference has no other descendent references we can remove it.
-                if propertyReference.references == [reference] {
-                    graph.remove(propertyReference)
-                    property.analyzerHints.append(.unreadProperty)
-                    property.analyzerHints.append(.aggressive)
+                if configuration.useIndexStore {
+                    guard let caller = reference.parent else { continue }
+                    let getterUsr = transformToGetterUsr(fromMangledSetterUsr: reference.usr)
+                    let propertyUsr = transformToPropertyUsr(fromMangledSetterUsr: reference.usr)
+
+                    guard let property = graph.declaration(withUsr: propertyUsr),
+                        let propertyReference = caller.references.first(where: { $0.usr == propertyUsr }),
+                        !property.isComplexProperty else { continue }
+
+                    let hasGetterReference = caller.references.contains(where: { $0.kind == .functionAccessorGetter && $0.usr == getterUsr })
+                    if !hasGetterReference {
+                        graph.remove(propertyReference)
+                        property.analyzerHints.append(.unreadProperty)
+                        property.analyzerHints.append(.aggressive)
+                    }
+                } else {
+                    // Parent should be a reference to a simple property.
+                    guard let propertyReference = reference.parent as? Reference,
+                        let property = graph.declaration(withUsr: propertyReference.usr),
+                        !property.isComplexProperty else { continue }
+                    // If the property reference has no other descendent references we can remove it.
+                    if propertyReference.references == [reference] {
+                        graph.remove(propertyReference)
+                        property.analyzerHints.append(.unreadProperty)
+                        property.analyzerHints.append(.aggressive)
+                    }
                 }
             }
         }

Sources/PeripheryKit/Analyzer/Visitors/UnreadSimplePropertyReferenceEliminator.swift

@@ -0,0 +1,16 @@
+import Foundation
+
+class Cache<Key: Hashable, T> {
+    private var values = [Key: T]()
+    private let lock = NSLock()
+
+    private let factory: (Key) throws -> T
+    init(_ factory: @escaping (Key) throws -> T) {
+        self.factory = factory
+    }
+
+    func get(_ input: Key) throws -> T {
+        lock.lock(); defer { lock.unlock() }
+        return try values[input] ?? factory(input)
+    }
+}

Sources/PeripheryKit/Cache.swift

@@ -30,6 +30,8 @@ public final class Configuration: Singleton {
     var diagnosisConsole: Bool = false
     var strict: Bool = false
     var xcargs: String? = nil
+    var useIndexStore: Bool = false
+    var indexStorePath: String?
 
     // Non user facing.
     var guidedSetup: Bool = false
@@ -57,7 +59,9 @@ public final class Configuration: Singleton {
             "disable_update_check": !updateCheck,
             "diagnose": diagnosisConsole,
             "strict": strict,
-            "xcargs": xcargs
+            "xcargs": xcargs,
+            "use_index_store": useIndexStore,
+            "index_store_path": indexStorePath
         ]
 
         return try Yams.dump(object: config)
@@ -144,6 +148,14 @@ public final class Configuration: Singleton {
         if let value = yaml["xcargs"] as? String {
             self.xcargs = value
         }
+
+        if let value = yaml["use_index_store"] as? Bool {
+            self.useIndexStore = value
+        }
+
+        if let value = yaml["index_store_path"] as? String {
+            self.indexStorePath = value
+        }
     }
 
     // MARK: - Helpers

Sources/PeripheryKit/Configuration.swift

@@ -1,5 +1,6 @@
 import Foundation
 import ArgumentParser
+import TSCBasic
 
 public struct ScanCommand: ParsableCommand {
 
@@ -68,6 +69,12 @@ public struct ScanCommand: ParsableCommand {
     @Option(help: "Pass additional arguments to xcodebuild for the build phase")
     var xcargs: String?
 
+    @Flag(inversion: .prefixedNo, help: "Enable new indexing system using IndexStore")
+    var useIndexStore: Bool?
+
+    @Option(help: "Path to index that should be loaded. e.g. DerivedData/PROJECT/Index/DataStore")
+    var indexStorePath: String?
+
     public init() {}
 
     public func run() throws {
@@ -149,6 +156,23 @@ public struct ScanCommand: ParsableCommand {
             configuration.xcargs = xcargs
         }
 
+        if let useIndexStore = useIndexStore {
+            configuration.useIndexStore = useIndexStore
+        }
+
+        if let indexStorePath = indexStorePath {
+            configuration.indexStorePath = indexStorePath
+        }
+
+        if configuration.indexStorePath == nil && configuration.useIndexStore,
+            let buildRootEnv = ProcessInfo.processInfo.environment["BUILD_ROOT"] {
+            let buildRootPath = AbsolutePath(buildRootEnv)
+            configuration.indexStorePath = buildRootPath
+                .parentDirectory.parentDirectory
+                .appending(components: "Index", "DataStore")
+                .pathString
+        }
+
         if let formatName = format {
             configuration.outputFormat = try OutputFormat.make(named: formatName)
         }

Sources/PeripheryKit/Frontend/Commands/ScanCommand.swift

@@ -5,4 +5,5 @@ protocol Entity: CustomStringConvertible, AnyObject {
     var declarations: Set<Declaration> { get set }
     var references: Set<Reference> { get set }
     var parent: Entity? { get set }
+    var usr: String { get }
 }