Fix bug for methods returning MethodHandle

README.md

@@ -88,7 +88,7 @@ Import as a Gradle dependency:
 
 ```groovy
 dependencies {
-    implementation("io.github.over-run:marshal:0.1.0-alpha.30-jdk23")
+    implementation("io.github.over-run:marshal:0.1.0-alpha.31-jdk23")
 }
 ```
 

gradle.properties

@@ -12,7 +12,7 @@ projGroupId=io.github.over-run
 projArtifactId=marshal
 # The project name should only contain lowercase letters, numbers and hyphen.
 projName=marshal
-projVersion=0.1.0-alpha.30-jdk23
+projVersion=0.1.0-alpha.31-jdk23
 projDesc=Marshaler of native libraries
 # Uncomment them if you want to publish to maven repository.
 projUrl=https://github.com/Over-Run/marshal

src/main/java/overrun/marshal/Downcall.java

@@ -635,12 +635,16 @@ private static DowncallData generateData(
 
             // function descriptor
             final FunctionDescriptor get = descriptorMap.get(entrypoint);
-            final FunctionDescriptor descriptor = get != null ?
-                get :
-                DescriptorTransformer.getInstance().process(new DescriptorTransformer.Context(method,
-                    methodData.descriptorSkipFirstParameter(),
-                    methodData.parameters()));
-
+            final FunctionDescriptor descriptor;
+            if (method.getReturnType() == MethodHandle.class) {
+                descriptor = get;
+            } else {
+                descriptor = get != null ?
+                    get :
+                    DescriptorTransformer.getInstance().process(new DescriptorTransformer.Context(method,
+                        methodData.descriptorSkipFirstParameter(),
+                        methodData.parameters()));
+            }
             descriptorMap1.put(entrypoint, descriptor);
 
             final Optional<MemorySegment> optional = lookup.find(entrypoint);
@@ -664,7 +668,9 @@ private static DowncallData generateData(
                     throw new NoSuchElementException("Symbol not found: " + entrypoint + " (" + descriptor + "): " + methodData.signatureString());
                 }
             }
-            map.putIfAbsent(entrypoint, handle);
+            if (!map.containsKey(entrypoint) || map.get(entrypoint) == null) {
+                map.put(entrypoint, handle);
+            }
         }
         return new DowncallData(Collections.unmodifiableMap(descriptorMap1),
             Collections.unmodifiableMap(map),

src/test/java/overrun/marshal/test/downcall/IDowncall.java

@@ -38,14 +38,20 @@
  * @since 0.1.0
  */
 public interface IDowncall {
-    Map<String, FunctionDescriptor> MAP = Map.of("testDefault", FunctionDescriptor.of(ValueLayout.JAVA_INT));
+    Map<String, FunctionDescriptor> MAP = Map.of(
+        "testDefault", FunctionDescriptor.of(ValueLayout.JAVA_INT),
+        "testReturnInt", FunctionDescriptor.of(ValueLayout.JAVA_INT)
+    );
 
     static IDowncall getInstance(boolean testDefaultNull) {
         ProcessorTypes.registerStruct(Vector3.class, Vector3.OF);
         ProcessorTypes.registerUpcall(SimpleUpcall.class, stub -> i -> SimpleUpcall.invoke(stub, i));
         return Downcall.load(MethodHandles.lookup(), DowncallProvider.lookup(testDefaultNull), DowncallOption.descriptors(MAP));
     }
 
+    @Entrypoint("testReturnInt")
+    MethodHandle mh_testReturnInt();
+
     void test();
 
     @Entrypoint("test")