jextract: hide memory location wrapping constructor, give it proper name

Sources/JExtractSwiftLib/FFM/ConversionStep.swift

@@ -123,7 +123,7 @@ enum ConversionStep: Equatable {
       // of splatting out text.
       let renderedArgumentList = renderedArguments.joined(separator: ", ")
       return "\(raw: type.description)(\(raw: renderedArgumentList))"
-
+    
     case .tuplify(let elements):
       let renderedElements: [String] = elements.enumerated().map { (index, element) in
         element.asExprSyntax(placeholder: "\(placeholder)_\(index)", bodyItems: &bodyItems)!.description

Sources/JExtractSwiftLib/FFM/FFMSwift2JavaGenerator+JavaBindingsPrinting.swift

@@ -407,6 +407,7 @@ extension FFMSwift2JavaGenerator {
         "arena$"
       }
 
+      // FIXME: use trailing$ convention
       let varName = outParameter.name.isEmpty ? "_result" : "_result_" + outParameter.name
 
       printer.print(
@@ -463,7 +464,7 @@ extension FFMSwift2JavaGenerator.JavaConversionStep {
     switch self {
     case .placeholder, .explodedName, .constant, .readMemorySegment:
       return false
-    case .constructSwiftValue:
+    case .constructSwiftValue, .wrapMemoryAddressUnsafe:
       return true
 
     case .call(let inner, _, _), .cast(let inner, _), .construct(let inner, _),
@@ -482,7 +483,11 @@ extension FFMSwift2JavaGenerator.JavaConversionStep {
       return false
     case .readMemorySegment:
       return true
-    case .cast(let inner, _), .construct(let inner, _), .constructSwiftValue(let inner, _), .swiftValueSelfSegment(let inner):
+    case .cast(let inner, _), 
+         .construct(let inner, _), 
+         .constructSwiftValue(let inner, _), 
+         .swiftValueSelfSegment(let inner),
+         .wrapMemoryAddressUnsafe(let inner, _):
       return inner.requiresSwiftArena
     case .call(let inner, _, let withArena):
       return withArena || inner.requiresTemporaryArena
@@ -522,6 +527,10 @@ extension FFMSwift2JavaGenerator.JavaConversionStep {
       let inner = inner.render(&printer, placeholder)
       return "new \(javaType.className!)(\(inner), swiftArena$)"
 
+    case .wrapMemoryAddressUnsafe(let inner, let javaType):
+      let inner = inner.render(&printer, placeholder)
+      return "\(javaType.className!).wrapMemoryAddressUnsafe(\(inner), swiftArena$)"
+
     case .construct(let inner, let javaType):
       let inner = inner.render(&printer, placeholder)
       return "new \(javaType)(\(inner))"

Sources/JExtractSwiftLib/FFM/FFMSwift2JavaGenerator+JavaTranslation.swift

@@ -684,7 +684,7 @@ extension FFMSwift2JavaGenerator {
           outParameters: [
             JavaParameter(name: "", type: javaType)
           ],
-          conversion: .constructSwiftValue(.placeholder, javaType)
+          conversion: .wrapMemoryAddressUnsafe(.placeholder, javaType)
         )
 
       case .tuple:
@@ -732,6 +732,9 @@ extension FFMSwift2JavaGenerator {
     // Call 'new \(Type)(\(placeholder), swiftArena$)'.
     indirect case constructSwiftValue(JavaConversionStep, JavaType)
 
+    /// Call the `MyType.wrapMemoryAddressUnsafe` in order to wrap a memory address using the Java binding type
+    indirect case wrapMemoryAddressUnsafe(JavaConversionStep, JavaType)
+
     // Construct the type using the placeholder as arguments.
     indirect case construct(JavaConversionStep, JavaType)
 

Sources/JExtractSwiftLib/FFM/FFMSwift2JavaGenerator.swift

@@ -216,9 +216,22 @@ extension FFMSwift2JavaGenerator {
 
       printer.print(
         """
-        public \(decl.swiftNominal.name)(MemorySegment segment, AllocatingSwiftArena arena) {
+        private \(decl.swiftNominal.name)(MemorySegment segment, AllocatingSwiftArena arena) {
           super(segment, arena);
         }
+
+        /** 
+         * Assume that the passed {@code MemorySegment} represents a memory address of a {@link \(decl.swiftNominal.name)}.
+         * <p/>
+         * Warnings:
+         * <ul>
+         *   <li>No checks are performed about the compatibility of the pointed at memory and the actual \(decl.swiftNominal.name) types.</li>
+         *   <li>This operation does not copy, or retain, the pointed at pointer, so its lifetime must be ensured manually to be valid when wrapping.</li>
+         * </ul>
+         */
+        public static \(decl.swiftNominal.name) wrapMemoryAddressUnsafe(MemorySegment selfPointer, AllocatingSwiftArena swiftArena) {
+          return new \(decl.swiftNominal.name)(selfPointer, swiftArena);
+        }
         """
       )
 

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+JavaBindingsPrinting.swift

@@ -117,9 +117,22 @@ extension JNISwift2JavaGenerator {
 
       printer.print(
         """
-        public \(decl.swiftNominal.name)(long selfPointer, SwiftArena swiftArena) {
+        private \(decl.swiftNominal.name)(long selfPointer, SwiftArena swiftArena) {
           super(selfPointer, swiftArena);
         }
+
+        /** 
+         * Assume that the passed {@code long} represents a memory address of a {@link \(decl.swiftNominal.name)}.
+         * <p/>
+         * Warnings:
+         * <ul>
+         *   <li>No checks are performed about the compatibility of the pointed at memory and the actual \(decl.swiftNominal.name) types.</li>
+         *   <li>This operation does not copy, or retain, the pointed at pointer, so its lifetime must be ensured manually to be valid when wrapping.</li>
+         * </ul>
+         */
+        public static \(decl.swiftNominal.name) wrapMemoryAddressUnsafe(long selfPointer, SwiftArena swiftArena) {
+          return new \(decl.swiftNominal.name)(selfPointer, swiftArena);
+        }
         """
       )
 

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+JavaTranslation.swift

@@ -383,7 +383,7 @@ extension JNISwift2JavaGenerator {
           javaType: javaType,
           annotations: resultAnnotations,
           outParameters: [],
-          conversion: .constructSwiftValue(.placeholder, javaType)
+          conversion: .wrapMemoryAddressUnsafe(.placeholder, javaType)
         )
 
       case .tuple([]):
@@ -465,7 +465,7 @@ extension JNISwift2JavaGenerator {
             discriminatorName: "result_discriminator$",
             optionalClass: "Optional",
             javaType: .long,
-            toValue: .constructSwiftValue(.placeholder, .class(package: nil, name: nominalTypeName))
+            toValue: .wrapMemoryAddressUnsafe(.placeholder, .class(package: nil, name: nominalTypeName))
           )
         )
 
@@ -582,6 +582,9 @@ extension JNISwift2JavaGenerator {
     /// Call `new \(Type)(\(placeholder), swiftArena$)`
     indirect case constructSwiftValue(JavaNativeConversionStep, JavaType)
 
+    /// Call the `MyType.wrapMemoryAddressUnsafe` in order to wrap a memory address using the Java binding type
+    indirect case wrapMemoryAddressUnsafe(JavaNativeConversionStep, JavaType)
+
     indirect case call(JavaNativeConversionStep, function: String)
 
     indirect case method(JavaNativeConversionStep, function: String, arguments: [JavaNativeConversionStep] = [])
@@ -641,6 +644,10 @@ extension JNISwift2JavaGenerator {
       case .constructSwiftValue(let inner, let javaType):
         let inner = inner.render(&printer, placeholder)
         return "new \(javaType.className!)(\(inner), swiftArena$)"
+
+      case .wrapMemoryAddressUnsafe(let inner, let javaType):
+        let inner = inner.render(&printer, placeholder)
+        return "\(javaType.className!).wrapMemoryAddressUnsafe(\(inner), swiftArena$)"
 
       case .call(let inner, let function):
         let inner = inner.render(&printer, placeholder)
@@ -705,7 +712,7 @@ extension JNISwift2JavaGenerator {
       case .placeholder, .constant, .isOptionalPresent:
         return false
 
-      case .constructSwiftValue:
+      case .constructSwiftValue, .wrapMemoryAddressUnsafe:
         return true
 
       case .valueMemoryAddress(let inner):

Tests/JExtractSwiftTests/DataImportTests.swift

@@ -86,7 +86,7 @@ final class DataImportTests {
       ]
     )
   }
-
+  
   @Test("Import Data: JavaBindings")
   func data_javaBindings() throws {
 
@@ -167,7 +167,7 @@ final class DataImportTests {
         public static Data returnData(AllocatingSwiftArena swiftArena$) {
           MemorySegment _result = swiftArena$.allocate(Data.$LAYOUT);
           swiftjava_SwiftModule_returnData.call(_result);
-          return new Data(_result, swiftArena$);
+          return Data.wrapMemoryAddressUnsafe(_result, swiftArena$);
         }
         """,
 
@@ -210,7 +210,7 @@ final class DataImportTests {
         public static Data init(java.lang.foreign.MemorySegment bytes, long count, AllocatingSwiftArena swiftArena$) {
           MemorySegment _result = swiftArena$.allocate(Data.$LAYOUT);
           swiftjava_SwiftModule_Data_init_bytes_count.call(bytes, count, _result);
-          return new Data(_result, swiftArena$);
+          return Data.wrapMemoryAddressUnsafe(_result, swiftArena$);
         }
         """,
 
@@ -408,4 +408,5 @@ final class DataImportTests {
       ]
     )
   }
+
 }

Tests/JExtractSwiftTests/JNI/JNIClassTests.swift

@@ -66,11 +66,17 @@ struct JNIClassTests {
             System.loadLibrary(LIB_NAME);
             return true;
           }
-
-          public MyClass(long selfPointer, SwiftArena swiftArena) {
+        """,
+        """
+          private MyClass(long selfPointer, SwiftArena swiftArena) {
             super(selfPointer, swiftArena);
           }
         """,
+        """
+        public static MyClass wrapMemoryAddressUnsafe(long selfPointer, SwiftArena swiftArena) {
+          return new MyClass(selfPointer, swiftArena);
+        }
+        """
       ])
     try assertOutput(
       input: source,
@@ -164,7 +170,7 @@ struct JNIClassTests {
           * }
           */
         public static MyClass init(long x, long y, SwiftArena swiftArena$) {
-          return new MyClass(MyClass.$init(x, y), swiftArena$);
+          return MyClass.wrapMemoryAddressUnsafe(MyClass.$init(x, y), swiftArena$);
         }
         """,
         """
@@ -175,7 +181,7 @@ struct JNIClassTests {
           * }
           */
         public static MyClass init(SwiftArena swiftArena$) {
-          return new MyClass(MyClass.$init(), swiftArena$);
+          return MyClass.wrapMemoryAddressUnsafe(MyClass.$init(), swiftArena$);
         }
         """,
         """
@@ -309,7 +315,7 @@ struct JNIClassTests {
           * }
           */
         public MyClass copy(SwiftArena swiftArena$) {
-          return new MyClass(MyClass.$copy(this.$memoryAddress()), swiftArena$);
+          return MyClass.wrapMemoryAddressUnsafe(MyClass.$copy(this.$memoryAddress()), swiftArena$);
         }
         """,
         """

Tests/JExtractSwiftTests/JNI/JNIOptionalTests.swift

@@ -158,7 +158,7 @@ struct JNIOptionalTests {
         public static Optional<MyClass> optionalClass(Optional<MyClass> arg, SwiftArena swiftArena$) {
           byte[] result_discriminator$ = new byte[1];
           long result$ = SwiftModule.$optionalClass(arg.map(MyClass::$memoryAddress).orElse(0L), result_discriminator$);
-          return (result_discriminator$[0] == 1) ? Optional.of(new MyClass(result$, swiftArena$)) : Optional.empty();
+          return (result_discriminator$[0] == 1) ? Optional.of(MyClass.wrapMemoryAddressUnsafe(result$, swiftArena$)) : Optional.empty();
         }
       """,
       """

Tests/JExtractSwiftTests/JNI/JNIStructTests.swift

@@ -56,10 +56,16 @@ struct JNIStructTests {
             System.loadLibrary(LIB_NAME);
             return true;
           }
-
-          public MyStruct(long selfPointer, SwiftArena swiftArena) {
+        """,
+        """
+          private MyStruct(long selfPointer, SwiftArena swiftArena) {
             super(selfPointer, swiftArena);
           }
+        """,
+        """
+        public static MyStruct wrapMemoryAddressUnsafe(long selfPointer, SwiftArena swiftArena) {
+          return new MyStruct(selfPointer, swiftArena);
+        }
         """
       ])
     try assertOutput(
@@ -110,7 +116,7 @@ struct JNIStructTests {
           * }
           */
         public static MyStruct init(long x, long y, SwiftArena swiftArena$) {
-          return new MyStruct(MyStruct.$init(x, y), swiftArena$);
+          return MyStruct.wrapMemoryAddressUnsafe(MyStruct.$init(x, y), swiftArena$);
         }
         """,
         """

Tests/JExtractSwiftTests/MemoryManagementModeTests.swift

@@ -43,7 +43,7 @@ struct MemoryManagementModeTests {
           * }
           */
           public static MyClass f(SwiftArena swiftArena$) {
-            return new MyClass(SwiftModule.$f(), swiftArena$);
+            return MyClass.wrapMemoryAddressUnsafe(SwiftModule.$f(), swiftArena$);
           }
         """,
       ]
@@ -68,7 +68,7 @@ struct MemoryManagementModeTests {
         """,
         """
         public static MyClass f(SwiftArena swiftArena$) {
-          return new MyClass(SwiftModule.$f(), swiftArena$);
+          return MyClass.wrapMemoryAddressUnsafe(SwiftModule.$f(), swiftArena$);
         }
         """,
       ]

Tests/JExtractSwiftTests/MethodImportTests.swift

@@ -227,7 +227,7 @@ final class MethodImportTests {
         public static MySwiftClass globalReturnClass(AllocatingSwiftArena swiftArena$) {
           MemorySegment _result = swiftArena$.allocate(MySwiftClass.$LAYOUT);
           swiftjava___FakeModule_globalReturnClass.call(_result);
-          return new MySwiftClass(_result, swiftArena$);
+          return MySwiftClass.wrapMemoryAddressUnsafe(_result, swiftArena$);
         }
         """
     )
@@ -404,7 +404,7 @@ final class MethodImportTests {
         public static MySwiftClass init(long len, long cap, AllocatingSwiftArena swiftArena$) {
             MemorySegment _result = swiftArena$.allocate(MySwiftClass.$LAYOUT);
             swiftjava___FakeModule_MySwiftClass_init_len_cap.call(len, cap, _result)
-            return new MySwiftClass(_result, swiftArena$);
+            return MySwiftClass.wrapMemoryAddressUnsafe(_result, swiftArena$);
         }
         """
     )
@@ -449,7 +449,7 @@ final class MethodImportTests {
         public static MySwiftStruct init(long len, long cap, AllocatingSwiftArena swiftArena$) {
             MemorySegment _result = swiftArena$.allocate(MySwiftStruct.$LAYOUT);
             swiftjava___FakeModule_MySwiftStruct_init_len_cap.call(len, cap, _result)
-            return new MySwiftStruct(_result, swiftArena$);
+            return MySwiftStruct.wrapMemoryAddressUnsafe(_result, swiftArena$);
         }
         """
     )