Maintain a Swift type name -> imported type mapping in jextract-swift

Switch the representation of the imported types from a flat list over to
a dictionary mapping from the Swift name to the imported type. We need
this so that we can find information about the Swift type when it is
referenced elsewhere in the syntax tree, such as extensions or uses of
that type in other function signatures.

While here, stop recording intermediate results within the visitor
itself. Instead, keep a reference to the full translator and record
results there incrementally. This will become more important when we
start handling extensions.

Author: DougGregor

Sources/JExtractSwift/ImportedDecls.swift

@@ -25,17 +25,28 @@ public struct ImportedProtocol: ImportedDecl {
   public var identifier: String
 }
 
-public struct ImportedClass: ImportedDecl {
+/// Describes a Swift nominal type (e.g., a class, struct, enum) that has been
+/// imported and is being translated into Java.
+public struct ImportedNominalType: ImportedDecl {
   public var name: ImportedTypeName
+  public var kind: NominalTypeKind
 
   public var initializers: [ImportedFunc] = []
   public var methods: [ImportedFunc] = []
 
-  public init(name: ImportedTypeName) {
+  public init(name: ImportedTypeName, kind: NominalTypeKind) {
     self.name = name
+    self.kind = kind
   }
 }
 
+public enum NominalTypeKind {
+  case `actor`
+  case `class`
+  case `enum`
+  case `struct`
+}
+
 public struct ImportedParam: Hashable {
   let param: FunctionParameterSyntax
 
@@ -97,9 +108,10 @@ public struct ImportedTypeName: Hashable {
     javaType.className
   }
 
-  public init(swiftTypeName: String, javaType: JavaType) {
+  public init(swiftTypeName: String, javaType: JavaType, swiftMangledName: String? = nil) {
     self.swiftTypeName = swiftTypeName
     self.javaType = javaType
+    self.swiftMangledName = swiftMangledName ?? ""
   }
 }
 

Sources/JExtractSwift/Swift2JavaTranslator+Printing.swift

@@ -27,7 +27,7 @@ extension Swift2JavaTranslator {
   public func writeImportedTypesTo(outputDirectory: String) throws {
     var printer = CodePrinter()
 
-    for ty in importedTypes {
+    for (_, ty) in importedTypes.sorted(by: { (lhs, rhs) in lhs.key < rhs.key }) {
       let filename = "\(ty.name.javaClassName!).java"
       log.info("Printing contents: \(filename)")
       printImportedClass(&printer, ty)
@@ -106,7 +106,7 @@ extension Swift2JavaTranslator {
     }
   }
 
-  public func printImportedClass(_ printer: inout CodePrinter, _ decl: ImportedClass) {
+  public func printImportedClass(_ printer: inout CodePrinter, _ decl: ImportedNominalType) {
     printHeader(&printer)
     printPackage(&printer)
     printImports(&printer)  // TODO print any imports the file may need, it we talk to other Swift modules
@@ -164,7 +164,7 @@ extension Swift2JavaTranslator {
     printer.print("")
   }
 
-  public func printClass(_ printer: inout CodePrinter, _ decl: ImportedClass, body: (inout CodePrinter) -> Void) {
+  public func printClass(_ printer: inout CodePrinter, _ decl: ImportedNominalType, body: (inout CodePrinter) -> Void) {
     printer.printTypeDecl("public final class \(decl.name.javaClassName!)") { printer in
       // ==== Storage of the class
       // FIXME: implement the self storage for the memory address and accessors
@@ -270,7 +270,7 @@ extension Swift2JavaTranslator {
     )
   }
 
-  private func printClassMemorySegmentConstructor(_ printer: inout CodePrinter, _ decl: ImportedClass) {
+  private func printClassMemorySegmentConstructor(_ printer: inout CodePrinter, _ decl: ImportedNominalType) {
     printer.print(
       """
       /** Instances are created using static {@code init} methods rather than through the constructor directly. */
@@ -282,7 +282,7 @@ extension Swift2JavaTranslator {
   }
 
   /// Print a property where we can store the "self" pointer of a class.
-  private func printClassSelfProperty(_ printer: inout CodePrinter, _ decl: ImportedClass) {
+  private func printClassSelfProperty(_ printer: inout CodePrinter, _ decl: ImportedNominalType) {
     printer.print(
       """
       // Pointer to the referred to class instance's "self".
@@ -295,7 +295,7 @@ extension Swift2JavaTranslator {
     )
   }
 
-  private func printClassMemoryLayout(_ printer: inout CodePrinter, _ decl: ImportedClass) {
+  private func printClassMemoryLayout(_ printer: inout CodePrinter, _ decl: ImportedNominalType) {
     printer.print(
       """
       private static final GroupLayout $LAYOUT = MemoryLayout.structLayout(

Sources/JExtractSwift/Swift2JavaTranslator.swift

@@ -37,7 +37,9 @@ public final class Swift2JavaTranslator {
   // TODO: consider how/if we need to store those etc
   public var importedGlobalFuncs: [ImportedFunc] = []
 
-  public var importedTypes: [ImportedClass] = []
+  /// A mapping from Swift type names (e.g., A.B) over to the imported nominal
+  /// type representation.
+  public var importedTypes: [String: ImportedNominalType] = [:]
 
   public init(
     javaPackage: String,
@@ -83,13 +85,10 @@ extension Swift2JavaTranslator {
     let visitor = Swift2JavaVisitor(
       moduleName: self.swiftModuleName,
       targetJavaPackage: self.javaPackage,
-      log: log
+      translator: self
     )
     visitor.walk(sourceFileSyntax)
 
-    self.importedGlobalFuncs.append(contentsOf: visitor.javaMethodDecls)
-    self.importedTypes.append(contentsOf: visitor.javaTypeDecls)
-
     try await self.postProcessImportedDecls()
   }
 
@@ -119,7 +118,7 @@ extension Swift2JavaTranslator {
       return funcDecl
     }
 
-    importedTypes = try await importedTypes._mapAsync { tyDecl in
+    importedTypes = Dictionary(uniqueKeysWithValues: try await importedTypes._mapAsync { (tyName, tyDecl) in
       var tyDecl = tyDecl
       log.info("Mapping type: \(tyDecl.name)")
 
@@ -140,8 +139,8 @@ extension Swift2JavaTranslator {
         return funcDecl
       }
 
-      return tyDecl
-    }
+      return (tyName, tyDecl)
+    })
   }
 }
 

Sources/JExtractSwift/Swift2JavaVisitor.swift

@@ -16,23 +16,23 @@ import SwiftParser
 import SwiftSyntax
 
 final class Swift2JavaVisitor: SyntaxVisitor {
-  let log: Logger
+  let translator: Swift2JavaTranslator
 
   /// The Swift module we're visiting declarations in
   let moduleName: String
+
   /// The target java package we are going to generate types into eventually,
   /// store this along with type names as we import them.
   let targetJavaPackage: String
 
-  var javaMethodDecls: [ImportedFunc] = []
-  var javaTypeDecls: [ImportedClass] = []
+  var currentTypeName: String? = nil
 
-  var currentTypeDecl: ImportedClass? = nil
+  var log: Logger { translator.log }
 
-  init(moduleName: String, targetJavaPackage: String, log: Logger) {
+  init(moduleName: String, targetJavaPackage: String, translator: Swift2JavaTranslator) {
     self.moduleName = moduleName
     self.targetJavaPackage = targetJavaPackage
-    self.log = log
+    self.translator = translator
 
     super.init(viewMode: .all)
   }
@@ -43,30 +43,28 @@ final class Swift2JavaVisitor: SyntaxVisitor {
     }
 
     log.info("Import: \(node.kind) \(node.name)")
-    currentTypeDecl = ImportedClass(
+    let typeName = node.name.text
+    currentTypeName = typeName
+    translator.importedTypes[typeName] = ImportedNominalType(
       // TODO: support nested classes (parent name here)
       name: ImportedTypeName(
-        swiftTypeName: node.name.text,
+        swiftTypeName: typeName,
         javaType: .class(
           package: targetJavaPackage,
-          name: node.name.text
-        )
-      )
+          name: typeName
+        ),
+        swiftMangledName: node.mangledNameFromComment
+      ),
+      kind: .class
     )
 
-    // Retrieve the mangled name, if available.
-    if let mangledName = node.mangledNameFromComment {
-      currentTypeDecl!.name.swiftMangledName = mangledName
-    }
-
     return .visitChildren
   }
 
   override func visitPost(_ node: ClassDeclSyntax) {
-    if let currentTypeDecl {
+    if currentTypeName != nil {
       log.info("Completed import: \(node.kind) \(node.name)")
-      self.javaTypeDecls.append(currentTypeDecl)
-      self.currentTypeDecl = nil
+      currentTypeName = nil
     }
   }
 
@@ -113,7 +111,7 @@ final class Swift2JavaVisitor: SyntaxVisitor {
     let fullName = "\(node.name.text)(\(argumentLabelsStr))"
 
     var funcDecl = ImportedFunc(
-      parentName: currentTypeDecl?.name,
+      parentName: currentTypeName.map { translator.importedTypes[$0] }??.name,
       identifier: fullName,
       returnType: javaResultType,
       parameters: params
@@ -125,26 +123,26 @@ final class Swift2JavaVisitor: SyntaxVisitor {
       funcDecl.swiftMangledName = mangledName
     }
 
-    if var currentTypeDecl = self.currentTypeDecl {
-      log.info("Record method in \(currentTypeDecl.name.javaType.description)")
-      currentTypeDecl.methods.append(funcDecl)
-      self.currentTypeDecl = currentTypeDecl
+    if let currentTypeName {
+      log.info("Record method in \(currentTypeName)")
+      translator.importedTypes[currentTypeName]?.methods.append(funcDecl)
     } else {
-      javaMethodDecls.append(funcDecl)
+      translator.importedGlobalFuncs.append(funcDecl)
     }
 
     return .skipChildren
   }
 
   override func visit(_ node: InitializerDeclSyntax) -> SyntaxVisitorContinueKind {
-    guard var currentTypeDecl = self.currentTypeDecl else {
+    guard let currentTypeName,
+            let currentType = translator.importedTypes[currentTypeName] else {
       fatalError("Initializer must be within a current type, was: \(node)")
     }
     guard node.shouldImport(log: log) else {
       return .skipChildren
     }
 
-    self.log.info("Import initializer: \(node.kind) \(currentTypeDecl.name.javaType.description)")
+    self.log.info("Import initializer: \(node.kind) \(currentType.name.javaType.description)")
     let params: [ImportedParam]
     do {
       params = try node.signature.parameterClause.parameters.map { param in
@@ -164,9 +162,9 @@ final class Swift2JavaVisitor: SyntaxVisitor {
       "init(\(params.compactMap { $0.effectiveName ?? "_" }.joined(separator: ":")))"
 
     var funcDecl = ImportedFunc(
-      parentName: currentTypeDecl.name,
+      parentName: currentType.name,
       identifier: initIdentifier,
-      returnType: currentTypeDecl.name,
+      returnType: currentType.name,
       parameters: params
     )
     funcDecl.isInit = true
@@ -177,9 +175,8 @@ final class Swift2JavaVisitor: SyntaxVisitor {
       funcDecl.swiftMangledName = mangledName
     }
 
-    log.info("Record initializer method in \(currentTypeDecl.name.javaType.description): \(funcDecl.identifier)")
-    currentTypeDecl.initializers.append(funcDecl)
-    self.currentTypeDecl = currentTypeDecl
+    log.info("Record initializer method in \(currentType.name.javaType.description): \(funcDecl.identifier)")
+    translator.importedTypes[currentTypeName]!.initializers.append(funcDecl)
 
     return .skipChildren
   }

Sources/JExtractSwift/SwiftDylib.swift

@@ -31,7 +31,7 @@ package struct SwiftDylib {  // FIXME: remove this entire utility; replace with
     self.log = Logger(label: "SwiftDylib(\(path))", logLevel: .trace)  // TODO: take from env
   }
 
-  package func fillInTypeMangledName(_ decl: ImportedClass) async throws -> ImportedClass {
+  package func fillInTypeMangledName(_ decl: ImportedNominalType) async throws -> ImportedNominalType {
     // TODO: this is hacky, not precise at all and will be removed entirely
     guard decl.name.swiftMangledName.isEmpty else {
       // it was already processed

Tests/JExtractSwiftTests/FuncImportTests.swift

@@ -181,9 +181,7 @@ final class MethodImportTests: XCTestCase {
 
     try await st.analyze(swiftInterfacePath: "/fake/__FakeModule/SwiftFile.swiftinterface", text: class_interfaceFile)
 
-    let funcDecl: ImportedFunc = st.importedTypes.first {
-      $0.name.javaClassName == "MySwiftClass"
-    }!.methods.first {
+    let funcDecl: ImportedFunc = st.importedTypes["MySwiftClass"]!.methods.first {
       $0.baseIdentifier == "helloMemberFunction"
     }!
 
@@ -224,9 +222,7 @@ final class MethodImportTests: XCTestCase {
 
     try await st.analyze(swiftInterfacePath: "/fake/__FakeModule/SwiftFile.swiftinterface", text: class_interfaceFile)
 
-    let funcDecl: ImportedFunc = st.importedTypes.first {
-      $0.name.javaClassName == "MySwiftClass"
-    }!.methods.first {
+    let funcDecl: ImportedFunc = st.importedTypes["MySwiftClass"]!.methods.first {
       $0.baseIdentifier == "helloMemberFunction"
     }!
 
@@ -267,9 +263,7 @@ final class MethodImportTests: XCTestCase {
 
     try await st.analyze(swiftInterfacePath: "/fake/__FakeModule/SwiftFile.swiftinterface", text: class_interfaceFile)
 
-    let funcDecl: ImportedFunc = st.importedTypes.first {
-      $0.name.javaClassName == "MySwiftClass"
-    }!.methods.first {
+    let funcDecl: ImportedFunc = st.importedTypes["MySwiftClass"]!.methods.first {
       $0.baseIdentifier == "helloMemberFunction"
     }!
 
@@ -302,9 +296,7 @@ final class MethodImportTests: XCTestCase {
 
     try await st.analyze(swiftInterfacePath: "/fake/__FakeModule/SwiftFile.swiftinterface", text: class_interfaceFile)
 
-    let funcDecl: ImportedFunc = st.importedTypes.first {
-      $0.name.javaClassName == "MySwiftClass"
-    }!.methods.first {
+    let funcDecl: ImportedFunc = st.importedTypes["MySwiftClass"]!.methods.first {
       $0.baseIdentifier == "makeInt"
     }!