jextract: Move Foundation support into a common package

Samples/SwiftJavaExtractFFMSampleApp/src/jmh/java/org/swift/swiftkit/ffm/FFMDataBenchmark.java

@@ -14,10 +14,10 @@
 
 package org.swift.swiftkit.ffm;
 
-import com.example.swift.Data;
 import com.example.swift.MySwiftLibrary;
 import org.openjdk.jmh.annotations.*;
 import org.openjdk.jmh.infra.Blackhole;
+import org.swift.swiftkit.ffm.foundation.Data;
 
 import java.lang.foreign.MemorySegment;
 import java.lang.foreign.ValueLayout;
@@ -79,7 +79,7 @@ public ByteBuffer ffm_data_withUnsafeBytes_asByteBuffer() {
       });
       return buf.value;
     }
-    
+
     @Benchmark
     public byte[] ffm_data_withUnsafeBytes_toArray() {
       Holder<byte[]> buf = new Holder<>();

Samples/SwiftJavaExtractFFMSampleApp/src/main/java/com/example/swift/HelloJava2Swift.java

@@ -22,6 +22,7 @@
 import org.swift.swiftkit.core.SwiftLibraries;
 import org.swift.swiftkit.ffm.AllocatingSwiftArena;
 import org.swift.swiftkit.ffm.SwiftRuntime;
+import org.swift.swiftkit.ffm.foundation.Data;
 
 import java.util.Optional;
 import java.util.OptionalLong;
@@ -85,7 +86,7 @@ static void examples() {
             var origBytes = arena.allocateFrom("foobar");
             var origDat = Data.init(origBytes, origBytes.byteSize(), arena);
             CallTraces.trace("origDat.count = " + origDat.getCount());
-            
+
             var retDat = MySwiftLibrary.globalReceiveReturnData(origDat, arena);
             retDat.withUnsafeBytes((retBytes) -> {
                 var str = retBytes.getString(0);

Samples/SwiftJavaExtractFFMSampleApp/src/test/java/com/example/swift/DataImportTest.java

@@ -16,6 +16,7 @@
 
 import org.junit.jupiter.api.Test;
 import org.swift.swiftkit.ffm.AllocatingSwiftArena;
+import org.swift.swiftkit.ffm.foundation.Data;
 
 import java.lang.foreign.ValueLayout;
 
@@ -134,7 +135,7 @@ void test_Data_toByteBuffer_emptyData() {
             byte[] original = new byte[0];
             var data = Data.fromByteArray(original, arena);
             var buffer = data.toByteBuffer(arena);
-            
+
             assertEquals(0, buffer.capacity());
         }
     }

Samples/SwiftJavaExtractFFMSampleApp/src/test/java/com/example/swift/OptionalImportTest.java

@@ -16,6 +16,7 @@
 
 import org.junit.jupiter.api.Test;
 import org.swift.swiftkit.ffm.AllocatingSwiftArena;
+import org.swift.swiftkit.ffm.foundation.Data;
 
 import java.util.Optional;
 import java.util.OptionalLong;

Samples/SwiftJavaExtractJNISampleApp/src/jmh/java/com/example/swift/JNIDataBenchmark.java

@@ -18,6 +18,7 @@
 import org.openjdk.jmh.infra.Blackhole;
 import org.swift.swiftkit.core.ClosableSwiftArena;
 import org.swift.swiftkit.core.SwiftArena;
+import org.swift.swiftkit.core.foundation.Data;
 
 import java.util.concurrent.TimeUnit;
 

Samples/SwiftJavaExtractJNISampleApp/src/test/java/com/example/swift/DataTest.java

@@ -16,6 +16,7 @@
 
 import org.junit.jupiter.api.Test;
 import org.swift.swiftkit.core.SwiftArena;
+import org.swift.swiftkit.core.foundation.Data;
 
 import static org.junit.jupiter.api.Assertions.*;
 

Samples/SwiftJavaExtractJNISampleApp/src/test/java/com/example/swift/DateTest.java

@@ -16,6 +16,7 @@
 
 import org.junit.jupiter.api.Test;
 import org.swift.swiftkit.core.SwiftArena;
+import org.swift.swiftkit.core.foundation.Date;
 
 import java.time.Instant;
 import java.time.temporal.ChronoUnit;
@@ -59,4 +60,4 @@ void date_timeIntervalSince1970() {
             assertEquals(1000, date.getTimeIntervalSince1970());
         }
     }
-}
+}

Samples/SwiftJavaExtractJNISampleApp/src/test/java/com/example/swift/OptionalsTest.java

@@ -14,9 +14,10 @@
 
 package com.example.swift;
 
-import com.example.swift.MySwiftLibrary;
 import org.junit.jupiter.api.Test;
 import org.swift.swiftkit.core.SwiftArena;
+import org.swift.swiftkit.core.foundation.Data;
+import org.swift.swiftkit.core.foundation.Date;
 
 import java.time.Instant;
 import java.util.Optional;
@@ -143,4 +144,4 @@ void optionalThrows() {
             assertEquals("swiftError", exception.getMessage());
         }
     }
-}
+}

Sources/JExtractSwiftLib/FFM/FFMSwift2JavaGenerator+JavaBindingsPrinting.swift

@@ -456,6 +456,8 @@ extension FFMSwift2JavaGenerator {
       let arena =
         if let className = type.className,
           analysis.importedTypes[className] != nil
+            || type == .swiftkitFFMFoundationData
+            || type == .swiftkitFFMFoundationDataProtocol
         {
           // Use passed-in 'SwiftArena' for 'SwiftValue'.
           "swiftArena"
@@ -619,7 +621,9 @@ extension FFMSwift2JavaGenerator {
   func renderMemoryLayoutValue(for javaType: JavaType) -> String {
     if let layout = ForeignValueLayout(javaType: javaType) {
       return layout.description
-    } else if case .class(package: _, name: let customClass, _) = javaType {
+    } else if case .class(.some(let package), name: let customClass, _) = javaType {
+      return ForeignValueLayout(customType: "\(package).\(customClass)").description
+    } else if case .class(.none, name: let customClass, _) = javaType {
       return ForeignValueLayout(customType: customClass).description
     } else {
       fatalError("renderMemoryLayoutValue not supported for \(javaType)")
@@ -776,7 +780,7 @@ extension FFMSwift2JavaGenerator.JavaConversionStep {
 
     case .wrapMemoryAddressUnsafe(let inner, let javaType):
       let inner = inner.render(&printer, placeholder, placeholderForDowncall: placeholderForDowncall)
-      return "\(javaType.className!).wrapMemoryAddressUnsafe(\(inner), swiftArena)"
+      return "\(javaType).wrapMemoryAddressUnsafe(\(inner), swiftArena)"
 
     case .construct(let inner, let javaType):
       let inner = inner.render(&printer, placeholder, placeholderForDowncall: placeholderForDowncall)

Sources/JExtractSwiftLib/FFM/FFMSwift2JavaGenerator+JavaTranslation.swift

@@ -464,7 +464,15 @@ extension FFMSwift2JavaGenerator {
             )
 
           case .foundationData, .essentialsData:
-            break
+            return TranslatedParameter(
+              javaParameters: [
+                JavaParameter(
+                  name: parameterName,
+                  type: .swiftkitFFMFoundationData
+                )
+              ],
+              conversion: .swiftValueSelfSegment(.placeholder)
+            )
 
           case .swiftJavaError:
             // SwiftJavaError is a class — treat as arbitrary nominal type below
@@ -635,10 +643,26 @@ extension FFMSwift2JavaGenerator {
       case .nominal(let nominal):
         if let knownType = nominal.nominalTypeDecl.knownTypeKind {
           switch knownType {
-          case .foundationData, .foundationDataProtocol:
-            break
-          case .essentialsData, .essentialsDataProtocol:
-            break
+          case .foundationData, .essentialsData:
+            return TranslatedParameter(
+              javaParameters: [
+                JavaParameter(
+                  name: parameterName,
+                  type: .optional(.swiftkitFFMFoundationData)
+                )
+              ],
+              conversion: .call(.placeholder, function: "SwiftRuntime.toOptionalSegmentInstance", withArena: false)
+            )
+          case .foundationDataProtocol, .essentialsDataProtocol:
+            return TranslatedParameter(
+              javaParameters: [
+                JavaParameter(
+                  name: parameterName,
+                  type: .optional(.swiftkitFFMFoundationDataProtocol)
+                )
+              ],
+              conversion: .call(.placeholder, function: "SwiftRuntime.toOptionalSegmentInstance", withArena: false)
+            )
           default:
             throw JavaTranslationError.unhandledType(known: .optional(swiftType))
           }
@@ -647,7 +671,7 @@ extension FFMSwift2JavaGenerator {
         let translatedTy = try self.translate(swiftType: swiftType)
         return TranslatedParameter(
           javaParameters: [
-            JavaParameter(name: parameterName, type: JavaType(className: "Optional<\(translatedTy.description)>"))
+            JavaParameter(name: parameterName, type: .optional(translatedTy))
           ],
           conversion: .call(.placeholder, function: "SwiftRuntime.toOptionalSegmentInstance", withArena: false)
         )
@@ -750,7 +774,15 @@ extension FFMSwift2JavaGenerator {
             )
 
           case .foundationData, .essentialsData:
-            break // Implemented as wrapper
+            let javaType: JavaType = .swiftkitFFMFoundationData
+            return TranslatedResult(
+              javaResultType: javaType,
+              annotations: resultAnnotations,
+              outParameters: [
+                JavaParameter(name: "", type: javaType)
+              ],
+              conversion: .wrapMemoryAddressUnsafe(.placeholder, javaType)
+            )
 
           case .unsafePointer, .unsafeMutablePointer:
             // FIXME: Implement