wasm gc: basic support for functors in JSO

core/src/main/resources/org/teavm/backend/wasm/wasm-gc-runtime.js

@@ -22,6 +22,7 @@ TeaVM.wasm = function() {
     }
     let javaObjectSymbol = Symbol("javaObject");
     let functionsSymbol = Symbol("functions");
+    let functionOriginSymbol = Symbol("functionOrigin");
     let javaWrappers = new WeakMap();
     function defaults(imports) {
         let stderr = "";
@@ -135,7 +136,7 @@ TeaVM.wasm = function() {
                         this[functionsSymbol] = null;
                     };`
                 );
-                return fn(javaObjectSymbol, functionsSymbol);
+                return fn(javaObjectSymbol, functionsSymbol, functionOriginSymbol);
             },
             defineMethod(cls, name, fn) {
                 cls.prototype[name] = function(...args) {
@@ -181,9 +182,20 @@ TeaVM.wasm = function() {
                     result = function() {
                         return instance[propertyName].apply(instance, arguments);
                     }
+                    result[functionOriginSymbol] = instance;
                     functions[propertyName] = result;
                 }
                 return result;
+            },
+            functionAsObject(fn, property) {
+                let origin = fn[functionOriginSymbol];
+                if (typeof origin !== 'undefined') {
+                    let functions = origin[functionsSymbol];
+                    if (functions !== void 0 && functions[property] === fn) {
+                        return origin;
+                    }
+                }
+                return { [property]: fn };
             }
         };
         for (let name of ["wrapByte", "wrapShort", "wrapChar", "wrapInt", "wrapFloat", "wrapDouble", "unwrapByte",

jso/impl/src/main/java/org/teavm/jso/impl/JS.java

@@ -743,6 +743,7 @@ public final class JS {
 
     @GeneratedBy(JSNativeGenerator.class)
     @PluggableDependency(JSNativeInjector.class)
+    @Import(name = "functionAsObject", module = "teavmJso")
     public static native JSObject functionAsObject(JSObject instance, JSObject property);
 
     @InjectedBy(JSNativeInjector.class)

jso/impl/src/main/java/org/teavm/jso/impl/JSObjectClassTransformer.java

@@ -87,7 +87,7 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
             processor.setClassFilter(classFilter);
         }
         processor.processClass(cls);
-        if (typeHelper.isJavaScriptClass(cls.getName())) {
+        if (isJavaScriptClass(cls)) {
             processor.processMemberMethods(cls);
         }
 
@@ -122,17 +122,17 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
         exposeMethods(cls, exposedClass, context.getDiagnostics(), functorMethod);
         exportStaticMethods(cls, context.getDiagnostics());
 
-        if (typeHelper.isJavaScriptImplementation(cls.getName()) || !exposedClass.methods.isEmpty()) {
+        if (isJavaScriptImplementation(cls) || !exposedClass.methods.isEmpty()) {
             cls.getAnnotations().add(new AnnotationHolder(JSClassToExpose.class.getName()));
         }
 
-        if (wasmGC && (!exposedClass.methods.isEmpty() || typeHelper.isJavaScriptClass(cls.getName()))) {
+        if (wasmGC && (!exposedClass.methods.isEmpty() || isJavaScriptClass(cls))) {
             var createWrapperMethod = new MethodHolder(JSMethods.MARSHALL_TO_JS);
             createWrapperMethod.setLevel(AccessLevel.PUBLIC);
             createWrapperMethod.getModifiers().add(ElementModifier.NATIVE);
             cls.addMethod(createWrapperMethod);
 
-            if (typeHelper.isJavaScriptImplementation(cls.getName())) {
+            if (isJavaScriptImplementation(cls)) {
                 cls.getInterfaces().add(JSMethods.JS_MARSHALLABLE);
             }
         }
@@ -387,6 +387,21 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
         return false;
     }
 
+    private boolean isJavaScriptImplementation(ClassReader cls) {
+        if (typeHelper.isJavaScriptImplementation(cls.getName())) {
+            return true;
+        }
+        if (cls.getAnnotations().get(JSClass.class.getName()) != null) {
+            return false;
+        }
+        if (cls.getParent() != null) {
+            if (typeHelper.isJavaScriptClass(cls.getParent())) {
+                return true;
+            }
+        }
+        return cls.getInterfaces().stream().anyMatch(typeHelper::isJavaScriptClass);
+    }
+
     private boolean addInterfaces(ExposedClass exposedCls, ClassReader cls) {
         boolean added = false;
         for (String ifaceName : cls.getInterfaces()) {

tests/src/test/java/org/teavm/jso/test/FunctorTest.java

@@ -26,12 +26,13 @@ import org.teavm.jso.JSProperty;
 import org.teavm.junit.EachTestCompiledSeparately;
 import org.teavm.junit.OnlyPlatform;
 import org.teavm.junit.SkipJVM;
+import org.teavm.junit.SkipPlatform;
 import org.teavm.junit.TeaVMTestRunner;
 import org.teavm.junit.TestPlatform;
 
 @RunWith(TeaVMTestRunner.class)
 @SkipJVM
-@OnlyPlatform(TestPlatform.JAVASCRIPT)
+@OnlyPlatform({TestPlatform.JAVASCRIPT, TestPlatform.WEBASSEMBLY_GC})
 @EachTestCompiledSeparately
 public class FunctorTest {
     @Test
@@ -45,6 +46,7 @@ public class FunctorTest {
     }
 
     @Test
+    @SkipPlatform(TestPlatform.WEBASSEMBLY_GC)
     public void functorIdentityPreserved() {
         JSBiFunction javaFunction = (a, b) -> a + b;
         JSObject firstRef = getFunction(javaFunction);
@@ -89,6 +91,7 @@ public class FunctorTest {
     }
 
     @Test
+    @SkipPlatform(TestPlatform.WEBASSEMBLY_GC)
     public void castToFunctor() {
         JSBiFunction f = getBiFunctionAsObject().cast();
         assertEquals(23042, f.foo(23, 42));