wasm gc: support exporting Java classes to JavaScript

core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java

@@ -77,6 +77,7 @@ public class Renderer implements RenderingManager {
 
     private final SourceWriter writer;
     private final ListableClassReaderSource classSource;
+    private final ClassReaderSource originalClassSource;
     private final ClassLoader classLoader;
     private final Properties properties = new Properties();
     private final ServiceRepository services;
@@ -103,6 +104,7 @@ public class Renderer implements RenderingManager {
             List<ExportedDeclaration> exports, String entryPoint) {
         this.writer = writer;
         this.classSource = context.getClassSource();
+        this.originalClassSource = context.getInitialClassSource();
         this.classLoader = context.getClassLoader();
         this.services = context.getServices();
         this.asyncMethods = new HashSet<>(asyncMethods);
@@ -152,6 +154,11 @@ public class Renderer implements RenderingManager {
         return classSource;
     }
 
+    @Override
+    public ClassReaderSource getOriginalClassSource() {
+        return originalClassSource;
+    }
+
     @Override
     public ClassLoader getClassLoader() {
         return classLoader;

core/src/main/java/org/teavm/backend/javascript/rendering/RenderingManager.java

@@ -18,6 +18,7 @@ package org.teavm.backend.javascript.rendering;
 import java.util.Properties;
 import org.teavm.backend.javascript.codegen.SourceWriter;
 import org.teavm.common.ServiceRepository;
+import org.teavm.model.ClassReaderSource;
 import org.teavm.model.ListableClassReaderSource;
 import org.teavm.model.MethodReference;
 
@@ -32,6 +33,8 @@ public interface RenderingManager extends ServiceRepository {
 
     ListableClassReaderSource getClassSource();
 
+    ClassReaderSource getOriginalClassSource();
+
     ClassLoader getClassLoader();
 
     Properties getProperties();

core/src/main/java/org/teavm/backend/wasm/WasmGCTarget.java

@@ -175,6 +175,7 @@ public class WasmGCTarget implements TeaVMTarget, TeaVMWasmGCHost {
         var declarationsGenerator = new WasmGCDeclarationsGenerator(
                 module,
                 classes,
+                controller.getUnprocessedClassSource(),
                 controller.getClassLoader(),
                 controller.getClassInitializerInfo(),
                 controller.getDependencyInfo(),

core/src/main/java/org/teavm/backend/wasm/generate/gc/WasmGCDeclarationsGenerator.java

@@ -34,6 +34,7 @@ import org.teavm.backend.wasm.model.WasmModule;
 import org.teavm.dependency.DependencyInfo;
 import org.teavm.diagnostics.Diagnostics;
 import org.teavm.model.ClassHierarchy;
+import org.teavm.model.ClassReaderSource;
 import org.teavm.model.ListableClassHolderSource;
 import org.teavm.model.MethodReference;
 import org.teavm.model.analysis.ClassInitializerInfo;
@@ -52,6 +53,7 @@ public class WasmGCDeclarationsGenerator {
     public WasmGCDeclarationsGenerator(
             WasmModule module,
             ListableClassHolderSource classes,
+            ClassReaderSource originalClasses,
             ClassLoader classLoader,
             ClassInitializerInfo classInitializerInfo,
             DependencyInfo dependencyInfo,
@@ -87,6 +89,7 @@ public class WasmGCDeclarationsGenerator {
         classGenerator = new WasmGCClassGenerator(
                 module,
                 classes,
+                originalClasses,
                 hierarchy,
                 dependencyInfo,
                 functionTypes,

core/src/main/java/org/teavm/backend/wasm/generate/gc/classes/WasmGCClassGenerator.java

@@ -102,6 +102,7 @@ public class WasmGCClassGenerator implements WasmGCClassInfoProvider, WasmGCInit
 
     private final WasmModule module;
     private ClassReaderSource classSource;
+    private ClassReaderSource originalClassSource;
     private ClassHierarchy hierarchy;
     private WasmFunctionTypes functionTypes;
     private TagRegistry tagRegistry;
@@ -158,7 +159,7 @@ public class WasmGCClassGenerator implements WasmGCClassInfoProvider, WasmGCInit
     private boolean hasLoadServices;
 
     public WasmGCClassGenerator(WasmModule module, ClassReaderSource classSource,
-            ClassHierarchy hierarchy, DependencyInfo dependencyInfo,
+            ClassReaderSource originalClassSource, ClassHierarchy hierarchy, DependencyInfo dependencyInfo,
             WasmFunctionTypes functionTypes, TagRegistry tagRegistry,
             ClassMetadataRequirements metadataRequirements, WasmGCVirtualTableProvider virtualTables,
             BaseWasmFunctionRepository functionProvider, WasmGCNameProvider names,
@@ -166,6 +167,7 @@ public class WasmGCClassGenerator implements WasmGCClassInfoProvider, WasmGCInit
             List<WasmGCCustomTypeMapperFactory> customTypeMapperFactories) {
         this.module = module;
         this.classSource = classSource;
+        this.originalClassSource = originalClassSource;
         this.hierarchy = hierarchy;
         this.functionTypes = functionTypes;
         this.tagRegistry = tagRegistry;
@@ -195,6 +197,11 @@ public class WasmGCClassGenerator implements WasmGCClassInfoProvider, WasmGCInit
 
     private WasmGCCustomTypeMapperFactoryContext customTypeMapperFactoryContext() {
         return new WasmGCCustomTypeMapperFactoryContext() {
+            @Override
+            public ClassReaderSource originalClasses() {
+                return originalClassSource;
+            }
+
             @Override
             public ClassReaderSource classes() {
                 return classSource;

core/src/main/java/org/teavm/backend/wasm/generate/gc/classes/WasmGCCustomTypeMapperFactoryContext.java

@@ -22,6 +22,8 @@ import org.teavm.model.ClassReaderSource;
 public interface WasmGCCustomTypeMapperFactoryContext {
     ClassReaderSource classes();
 
+    ClassReaderSource originalClasses();
+
     WasmModule module();
 
     WasmGCClassInfoProvider classInfoProvider();

core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCMethodGenerator.java

@@ -433,5 +433,10 @@ public class WasmGCMethodGenerator implements BaseWasmFunctionRepository {
         public WasmGCStringProvider strings() {
             return context.strings();
         }
+
+        @Override
+        public void addToInitializer(Consumer<WasmFunction> initializerContributor) {
+            context.addToInitializer(initializerContributor);
+        }
     };
 }

core/src/main/java/org/teavm/backend/wasm/generators/gc/WasmGCCustomGeneratorContext.java

@@ -15,12 +15,14 @@
  */
 package org.teavm.backend.wasm.generators.gc;
 
+import java.util.function.Consumer;
 import org.teavm.backend.wasm.BaseWasmFunctionRepository;
 import org.teavm.backend.wasm.WasmFunctionTypes;
 import org.teavm.backend.wasm.generate.gc.WasmGCNameProvider;
 import org.teavm.backend.wasm.generate.gc.classes.WasmGCClassInfoProvider;
 import org.teavm.backend.wasm.generate.gc.classes.WasmGCTypeMapper;
 import org.teavm.backend.wasm.generate.gc.strings.WasmGCStringProvider;
+import org.teavm.backend.wasm.model.WasmFunction;
 import org.teavm.backend.wasm.model.WasmModule;
 import org.teavm.backend.wasm.model.WasmTag;
 import org.teavm.diagnostics.Diagnostics;
@@ -48,4 +50,6 @@ public interface WasmGCCustomGeneratorContext {
     Diagnostics diagnostics();
 
     WasmGCStringProvider strings();
+
+    void addToInitializer(Consumer<WasmFunction> initializerContributor);
 }

core/src/main/java/org/teavm/backend/wasm/generators/gc/WasmGCCustomGenerators.java

@@ -108,6 +108,9 @@ public class WasmGCCustomGenerators implements WasmGCCustomGeneratorProvider {
             WasmGCCustomGenerator generator = null;
             for (var factory : factories) {
                 generator = factory.createGenerator(method, factoryContext);
+                if (generator != null) {
+                    break;
+                }
             }
             result = new Container(generator);
             generators.put(method, result);

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmExternConversion.java

@@ -0,0 +1,19 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.wasm.model.expression;
+
+public class WasmExternConversion {
+}

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmExternConversionType.java

@@ -0,0 +1,21 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.wasm.model.expression;
+
+public enum WasmExternConversionType {
+    EXTERN_TO_OBJECT,
+    OBJECT_TO_EXTERN
+}

core/src/main/java/org/teavm/dependency/DependencyAnalyzer.java

@@ -42,7 +42,6 @@ import org.teavm.common.ServiceRepository;
 import org.teavm.diagnostics.Diagnostics;
 import org.teavm.interop.PlatformMarker;
 import org.teavm.model.AnnotationReader;
-import org.teavm.model.BasicBlock;
 import org.teavm.model.CallLocation;
 import org.teavm.model.ClassHierarchy;
 import org.teavm.model.ClassHolder;
@@ -52,8 +51,6 @@ import org.teavm.model.ClassReaderSource;
 import org.teavm.model.ElementModifier;
 import org.teavm.model.FieldReader;
 import org.teavm.model.FieldReference;
-import org.teavm.model.Instruction;
-import org.teavm.model.InvokeDynamicInstruction;
 import org.teavm.model.MethodDescriptor;
 import org.teavm.model.MethodHolder;
 import org.teavm.model.MethodReader;
@@ -61,12 +58,7 @@ import org.teavm.model.MethodReference;
 import org.teavm.model.Program;
 import org.teavm.model.ReferenceCache;
 import org.teavm.model.ValueType;
-import org.teavm.model.emit.ProgramEmitter;
-import org.teavm.model.emit.ValueEmitter;
-import org.teavm.model.instructions.AssignInstruction;
-import org.teavm.model.instructions.NullConstantInstruction;
 import org.teavm.model.optimization.UnreachableBasicBlockEliminator;
-import org.teavm.model.util.BasicBlockSplitter;
 import org.teavm.model.util.ModelUtils;
 import org.teavm.model.util.ProgramUtils;
 import org.teavm.parsing.Parser;
@@ -102,7 +94,6 @@ public abstract class DependencyAnalyzer implements DependencyInfo {
     private Diagnostics diagnostics;
     DefaultCallGraph callGraph = new DefaultCallGraph();
     private DependencyAgent agent;
-    Map<MethodReference, BootstrapMethodSubstitutor> bootstrapMethodSubstitutors = new HashMap<>();
     Map<MethodReference, DependencyPlugin> dependencyPlugins = new HashMap<>();
     private boolean completing;
     private Map<String, DependencyTypeFilter> superClassFilters = new HashMap<>();
@@ -119,7 +110,8 @@ public abstract class DependencyAnalyzer implements DependencyInfo {
         this.unprocessedClassSource = classSource;
         this.diagnostics = diagnostics;
         this.referenceCache = referenceCache;
-        this.classSource = new DependencyClassSource(classSource, diagnostics, incrementalCache, platformTags);
+        agent = new DependencyAgent(this);
+        this.classSource = new DependencyClassSource(agent, classSource, diagnostics, incrementalCache, platformTags);
         agentClassSource = this.classSource;
         classHierarchy = new ClassHierarchy(this.classSource);
         this.classLoader = classLoader;
@@ -138,7 +130,6 @@ public abstract class DependencyAnalyzer implements DependencyInfo {
 
         classCache = new CachedFunction<>(this::createClassDependency);
 
-        agent = new DependencyAgent(this);
         classType = getType("java.lang.Class");
     }
 
@@ -274,7 +265,6 @@ public abstract class DependencyAnalyzer implements DependencyInfo {
             dep.used = false;
             lock(dep, false);
             deferredTasks.add(() -> {
-                processInvokeDynamic(dep);
                 classSource.getReferenceResolver().use(dep.method.getReference(), diagnostics);
                 processMethod(dep);
                 dep.used = true;
@@ -489,7 +479,6 @@ public abstract class DependencyAnalyzer implements DependencyInfo {
     void scheduleMethodAnalysis(MethodDependency dep) {
         classSource.getReferenceResolver().use(dep.getReference(), diagnostics);
         deferredTasks.add(() -> {
-            processInvokeDynamic(dep);
             classSource.getReferenceResolver().use(dep.getReference(), diagnostics);
             processMethod(dep);
         });
@@ -755,6 +744,7 @@ public abstract class DependencyAnalyzer implements DependencyInfo {
         agent.cleanup();
         listeners.clear();
 
+        classSource.dispose();
         agentClassSource = classSourcePacker.pack(classSource,
                 ClassClosureAnalyzer.build(classSource, new ArrayList<>(classSource.cache.keySet())));
         if (classSource != agentClassSource) {
@@ -762,7 +752,7 @@ public abstract class DependencyAnalyzer implements DependencyInfo {
             generatedClassNames.addAll(classSource.getGeneratedClassNames());
         }
         classSource.innerHierarchy = null;
-        classSource.dispose();
+
         classSource = null;
         methodReaderCache = null;
     }
@@ -827,7 +817,7 @@ public abstract class DependencyAnalyzer implements DependencyInfo {
     }
 
     public void addBootstrapMethodSubstitutor(MethodReference method, BootstrapMethodSubstitutor substitutor) {
-        bootstrapMethodSubstitutors.put(method, substitutor);
+        classSource.bootstrapMethodSubstitutors.put(method, substitutor);
     }
 
     public void addDependencyPlugin(MethodReference method, DependencyPlugin dependencyPlugin) {
@@ -863,70 +853,6 @@ public abstract class DependencyAnalyzer implements DependencyInfo {
         return result;
     }
 
-    private void processInvokeDynamic(MethodDependency methodDep) {
-        if (methodDep.method == null) {
-            return;
-        }
-
-        Program program = methodDep.method.getProgram();
-        if (program == null) {
-            return;
-        }
-
-        ProgramEmitter pe = ProgramEmitter.create(program, classHierarchy);
-        BasicBlockSplitter splitter = new BasicBlockSplitter(program);
-        for (int i = 0; i < program.basicBlockCount(); ++i) {
-            BasicBlock block = program.basicBlockAt(i);
-            for (Instruction insn : block) {
-                if (!(insn instanceof InvokeDynamicInstruction)) {
-                    continue;
-                }
-                block = insn.getBasicBlock();
-
-                InvokeDynamicInstruction indy = (InvokeDynamicInstruction) insn;
-                MethodReference bootstrapMethod = new MethodReference(indy.getBootstrapMethod().getClassName(),
-                        indy.getBootstrapMethod().getName(), indy.getBootstrapMethod().signature());
-                BootstrapMethodSubstitutor substitutor = bootstrapMethodSubstitutors.get(bootstrapMethod);
-                if (substitutor == null) {
-                    NullConstantInstruction nullInsn = new NullConstantInstruction();
-                    nullInsn.setReceiver(indy.getReceiver());
-                    nullInsn.setLocation(indy.getLocation());
-                    insn.replace(nullInsn);
-                    CallLocation location = new CallLocation(methodDep.getReference(), insn.getLocation());
-                    diagnostics.error(location, "Substitutor for bootstrap method {{m0}} was not found",
-                            bootstrapMethod);
-                    continue;
-                }
-
-                BasicBlock splitBlock = splitter.split(block, insn);
-
-                pe.enter(block);
-                pe.setCurrentLocation(indy.getLocation());
-                insn.delete();
-
-                List<ValueEmitter> arguments = new ArrayList<>();
-                for (int k = 0; k < indy.getArguments().size(); ++k) {
-                    arguments.add(pe.var(indy.getArguments().get(k), indy.getMethod().parameterType(k)));
-                }
-                DynamicCallSite callSite = new DynamicCallSite(
-                        methodDep.getReference(), indy.getMethod(),
-                        indy.getInstance() != null ? pe.var(indy.getInstance(),
-                                ValueType.object(methodDep.getMethod().getOwnerName())) : null,
-                        arguments, indy.getBootstrapMethod(), indy.getBootstrapArguments(),
-                        agent);
-                ValueEmitter result = substitutor.substitute(callSite, pe);
-                if (result.getVariable() != null && result.getVariable() != indy.getReceiver()
-                        && indy.getReceiver() != null) {
-                    AssignInstruction assign = new AssignInstruction();
-                    assign.setAssignee(result.getVariable());
-                    assign.setReceiver(indy.getReceiver());
-                    pe.addInstruction(assign);
-                }
-                pe.jump(splitBlock);
-            }
-        }
-        splitter.fixProgram();
-    }
 
     static class IncrementalCache implements IncrementalDependencyProvider, IncrementalDependencyRegistration {
         private final String[] emptyArray = new String[0];

core/src/main/java/org/teavm/dependency/DependencyClassSource.java

@@ -17,12 +17,15 @@ package org.teavm.dependency;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import org.teavm.cache.IncrementalDependencyRegistration;
 import org.teavm.diagnostics.Diagnostics;
+import org.teavm.model.BasicBlock;
+import org.teavm.model.CallLocation;
 import org.teavm.model.ClassHierarchy;
 import org.teavm.model.ClassHolder;
 import org.teavm.model.ClassHolderSource;
@@ -30,12 +33,23 @@ import org.teavm.model.ClassHolderTransformer;
 import org.teavm.model.ClassHolderTransformerContext;
 import org.teavm.model.ClassReader;
 import org.teavm.model.ClassReaderSource;
+import org.teavm.model.Instruction;
+import org.teavm.model.InvokeDynamicInstruction;
 import org.teavm.model.MethodHolder;
+import org.teavm.model.MethodReference;
+import org.teavm.model.Program;
+import org.teavm.model.ValueType;
+import org.teavm.model.emit.ProgramEmitter;
+import org.teavm.model.emit.ValueEmitter;
+import org.teavm.model.instructions.AssignInstruction;
+import org.teavm.model.instructions.NullConstantInstruction;
 import org.teavm.model.optimization.UnreachableBasicBlockEliminator;
 import org.teavm.model.transformation.ClassInitInsertion;
+import org.teavm.model.util.BasicBlockSplitter;
 import org.teavm.model.util.ModelUtils;
 
 class DependencyClassSource implements ClassHolderSource {
+    private DependencyAgent agent;
     private ClassReaderSource innerSource;
     ClassHierarchy innerHierarchy;
     private Diagnostics diagnostics;
@@ -48,9 +62,12 @@ class DependencyClassSource implements ClassHolderSource {
     private ReferenceResolver referenceResolver;
     private ClassInitInsertion classInitInsertion;
     private String entryPoint;
+    Map<MethodReference, BootstrapMethodSubstitutor> bootstrapMethodSubstitutors = new HashMap<>();
+    private boolean disposed;
 
-    DependencyClassSource(ClassReaderSource innerSource, Diagnostics diagnostics,
+    DependencyClassSource(DependencyAgent agent, ClassReaderSource innerSource, Diagnostics diagnostics,
             IncrementalDependencyRegistration dependencyRegistration, String[] platformTags) {
+        this.agent = agent;
         this.innerSource = innerSource;
         this.diagnostics = diagnostics;
         innerHierarchy = new ClassHierarchy(innerSource);
@@ -65,7 +82,16 @@ class DependencyClassSource implements ClassHolderSource {
 
     @Override
     public ClassHolder get(String name) {
-        return cache.computeIfAbsent(name, n -> Optional.ofNullable(findAndTransformClass(n))).orElse(null);
+        var result = cache.get(name);
+        if (result == null) {
+            var cls = findClass(name);
+            result = Optional.ofNullable(cls);
+            cache.put(name, result);
+            if (cls != null) {
+                transformClass(cls);
+            }
+        }
+        return result.orElse(null);
     }
 
     public void submit(ClassHolder cls) {
@@ -84,26 +110,27 @@ class DependencyClassSource implements ClassHolderSource {
         cache.remove(cls.getName());
     }
 
-    private ClassHolder findAndTransformClass(String name) {
+    private void transformClass(ClassHolder cls) {
-        var cls = findClass(name);
+        if (!disposed) {
-        if (cls != null) {
-            if (!transformers.isEmpty()) {
-                for (var transformer : transformers) {
-                    transformer.transformClass(cls, transformContext);
-                }
-            }
             for (var method : cls.getMethods()) {
-                if (method.getProgram() != null) {
+                processInvokeDynamic(method);
-                    var program = method.getProgram();
+            }
-                    method.setProgramSupplier(m -> {
+        }
-                        referenceResolver.resolve(m, program);
+        if (!transformers.isEmpty()) {
-                        classInitInsertion.apply(m, program);
+            for (var transformer : transformers) {
-                        return program;
+                transformer.transformClass(cls, transformContext);
-                    });
+            }
-                }
+        }
+        for (var method : cls.getMethods()) {
+            if (method.getProgram() != null) {
+                var program = method.getProgram();
+                method.setProgramSupplier(m -> {
+                    referenceResolver.resolve(m, program);
+                    classInitInsertion.apply(m, program);
+                    return program;
+                });
             }
         }
-        return cls;
     }
 
     private ClassHolder findClass(String name) {
@@ -132,6 +159,69 @@ class DependencyClassSource implements ClassHolderSource {
 
     public void dispose() {
         transformers.clear();
+        bootstrapMethodSubstitutors.clear();
+        disposed = true;
+    }
+
+    private void processInvokeDynamic(MethodHolder method) {
+        Program program = method.getProgram();
+        if (program == null) {
+            return;
+        }
+
+        ProgramEmitter pe = ProgramEmitter.create(program, innerHierarchy);
+        BasicBlockSplitter splitter = new BasicBlockSplitter(program);
+        for (int i = 0; i < program.basicBlockCount(); ++i) {
+            BasicBlock block = program.basicBlockAt(i);
+            for (Instruction insn : block) {
+                if (!(insn instanceof InvokeDynamicInstruction)) {
+                    continue;
+                }
+                block = insn.getBasicBlock();
+
+                InvokeDynamicInstruction indy = (InvokeDynamicInstruction) insn;
+                MethodReference bootstrapMethod = new MethodReference(indy.getBootstrapMethod().getClassName(),
+                        indy.getBootstrapMethod().getName(), indy.getBootstrapMethod().signature());
+                BootstrapMethodSubstitutor substitutor = bootstrapMethodSubstitutors.get(bootstrapMethod);
+                if (substitutor == null) {
+                    NullConstantInstruction nullInsn = new NullConstantInstruction();
+                    nullInsn.setReceiver(indy.getReceiver());
+                    nullInsn.setLocation(indy.getLocation());
+                    insn.replace(nullInsn);
+                    CallLocation location = new CallLocation(method.getReference(), insn.getLocation());
+                    diagnostics.error(location, "Substitutor for bootstrap method {{m0}} was not found",
+                            bootstrapMethod);
+                    continue;
+                }
+
+                BasicBlock splitBlock = splitter.split(block, insn);
+
+                pe.enter(block);
+                pe.setCurrentLocation(indy.getLocation());
+                insn.delete();
+
+                List<ValueEmitter> arguments = new ArrayList<>();
+                for (int k = 0; k < indy.getArguments().size(); ++k) {
+                    arguments.add(pe.var(indy.getArguments().get(k), indy.getMethod().parameterType(k)));
+                }
+                DynamicCallSite callSite = new DynamicCallSite(
+                        method.getReference(), indy.getMethod(),
+                        indy.getInstance() != null ? pe.var(indy.getInstance(),
+                                ValueType.object(method.getOwnerName())) : null,
+                        arguments, indy.getBootstrapMethod(), indy.getBootstrapArguments(),
+                        agent);
+                ValueEmitter result = substitutor.substitute(callSite, pe);
+                if (result.getVariable() != null && result.getVariable() != indy.getReceiver()
+                        && indy.getReceiver() != null) {
+                    AssignInstruction assign = new AssignInstruction();
+                    assign.setAssignee(result.getVariable());
+                    assign.setReceiver(indy.getReceiver());
+                    pe.addInstruction(assign);
+                }
+                pe.jump(splitBlock);
+            }
+        }
+        splitter.fixProgram();
     }
 
     final ClassHolderTransformerContext transformContext = new ClassHolderTransformerContext() {

core/src/main/resources/org/teavm/backend/javascript/runtime.js

@@ -119,3 +119,7 @@ let $rt_apply = (instance, method, args) => instance[method].apply(instance, arg
 let $rt_apply_topLevel = (method, args) => method.apply(null, args);
 
 let $rt_skip = (array, count) => count === 0 ? array : Array.prototype.slice.call(array, count);
+
+let $rt_callWithReceiver = f => function() {
+    return f.apply(null, [this].concat(Array.prototype.slice.call(arguments)));
+}

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

@@ -20,6 +20,9 @@ TeaVM.wasm = function() {
     let getGlobalName = function(name) {
         return eval(name);
     }
+    let javaObjectSymbol = Symbol("javaObject");
+    let functionsSymbol = Symbol("functions");
+    let javaWrappers = new WeakMap();
     function defaults(imports) {
         let stderr = "";
         let stdout = "";
@@ -32,42 +35,28 @@ TeaVM.wasm = function() {
             exports.reportGarbageCollectedString(heldValue);
         });
         imports.teavmDate = {
-            currentTimeMillis() {
+            currentTimeMillis: () => new Date().getTime(),
-                return new Date().getTime();
+            dateToString: timestamp => stringToJava(new Date(timestamp).toString()),
-            },
+            getYear: timestamp =>new Date(timestamp).getFullYear(),
-            dateToString(timestamp) {
-                return stringToJava(new Date(timestamp).toString());
-            },
-            getYear(timestamp) {
-                return new Date(timestamp).getFullYear();
-            },
             setYear(timestamp, year) {
                 let date = new Date(timestamp);
                 date.setFullYear(year);
                 return date.getTime();
             },
-            getMonth(timestamp) {
+            getMonth: timestamp =>new Date(timestamp).getMonth(),
-                return new Date(timestamp).getMonth();
-            },
             setMonth(timestamp, month) {
                 let date = new Date(timestamp);
                 date.setMonth(month);
                 return date.getTime();
             },
-            getDate(timestamp) {
+            getDate: timestamp =>new Date(timestamp).getDate(),
-                return new Date(timestamp).getDate();
-            },
             setDate(timestamp, value) {
                 let date = new Date(timestamp);
                 date.setDate(value);
                 return date.getTime();
             },
-            create(year, month, date, hrs, min, sec) {
+            create: (year, month, date, hrs, min, sec) => new Date(year, month, date, hrs, min, sec).getTime(),
-                return new Date(year, month, date, hrs, min, sec).getTime();
+            createFromUTC: (year, month, date, hrs, min, sec) => Date.UTC(year, month, date, hrs, min, sec)
-            },
-            createFromUTC(year, month, date, hrs, min, sec) {
-                return Date.UTC(year, month, date, hrs, min, sec);
-            }
         };
         imports.teavmConsole = {
             putcharStderr(c) {
@@ -106,6 +95,22 @@ TeaVM.wasm = function() {
         function identity(value) {
             return value;
         }
+        function sanitizeName(str) {
+            let result = "";
+            let firstChar = str.charAt(0);
+            result += isIdentifierStart(firstChar) ? firstChar : '_';
+            for (let i = 1; i < str.length; ++i) {
+                let c = str.charAt(i)
+                result += isIdentifierPart(c) ? c : '_';
+            }
+            return result;
+        }
+        function isIdentifierStart(s) {
+            return s >= 'A' && s <= 'Z' || s >= 'a' && s <= 'z' || s === '_' || s === '$';
+        }
+        function isIdentifierPart(s) {
+            return isIdentifierStart(s) || s >= '0' && s <= '9';
+        }
         imports.teavmJso = {
             emptyString: () => "",
             stringFromCharCode: code => String.fromCharCode(code),
@@ -120,25 +125,76 @@ TeaVM.wasm = function() {
             getPropertyPure: (obj, prop) => obj[prop],
             setProperty: (obj, prop, value) => obj[prop] = value,
             setPropertyPure: (obj, prop) => obj[prop] = value,
-            global: getGlobalName
+            global: getGlobalName,
+            createClass(name) {
+                let fn = new Function(
+                    "javaObjectSymbol",
+                    "functionsSymbol",
+                    `return function JavaClass_${sanitizeName(name)}(javaObject) {
+                        this[javaObjectSymbol] = javaObject;
+                        this[functionsSymbol] = null;
+                    };`
+                );
+                return fn(javaObjectSymbol, functionsSymbol);
+            },
+            defineMethod(cls, name, fn) {
+                cls.prototype[name] = function(...args) {
+                    return fn(this, ...args);
+                }
+            },
+            defineProperty(cls, name, getFn, setFn) {
+                let descriptor = {
+                    get() {
+                        return getFn(this);
+                    }
+                };
+                if (setFn !== null) {
+                    descriptor.set = function(value) {
+                        setFn(this, value);
+                    }
+                }
+                Object.defineProperty(cls.prototype, name, descriptor);
+            },
+            javaObjectToJS(instance, cls) {
+                let existing = javaWrappers.get(instance);
+                if (typeof existing != "undefined") {
+                    let result = existing.deref();
+                    if (typeof result !== "undefined") {
+                        return result;
+                    }
+                }
+                let obj = new cls(instance);
+                javaWrappers.set(instance, new WeakRef(obj));
+                return obj;
+            },
+            unwrapJavaObject(instance) {
+                return instance[javaObjectSymbol];
+            },
+            asFunction(instance, propertyName) {
+                let functions = instance[functionsSymbol];
+                if (functions === null) {
+                    functions = Object.create(null);
+                    instance[functionsSymbol] = functions;
+                }
+                let result = functions[propertyName];
+                if (typeof result !== 'function') {
+                    result = function() {
+                        return instance[propertyName].apply(instance, arguments);
+                    }
+                    functions[propertyName] = result;
+                }
+                return result;
+            }
         };
         for (let name of ["wrapByte", "wrapShort", "wrapChar", "wrapInt", "wrapFloat", "wrapDouble", "unwrapByte",
                 "unwrapShort", "unwrapChar", "unwrapInt", "unwrapFloat", "unwrapDouble"]) {
             imports.teavmJso[name] = identity;
         }
         for (let i = 0; i < 32; ++i) {
-            imports.teavmJso["createFunction" + i] = function() {
+            imports.teavmJso["createFunction" + i] = (...args) => new Function(...args);
-                return new Function(...arguments);
+            imports.teavmJso["callFunction" + i] = (fn, ...args) => fn(...args);
-            };
+            imports.teavmJso["callMethod" + i] = (instance, method, ...args) => instance[method](...args);
-            imports.teavmJso["callFunction" + i] = function(fn, ...args) {
+            imports.teavmJso["construct" + i] = (constructor, ...args) => new constructor(...args);
-                return fn(...args);
-            };
-            imports.teavmJso["callMethod" + i] = function(instance, method, ...args) {
-                return instance[method](...args);
-            };
-            imports.teavmJso["construct" + i] = function(constructor, ...args) {
-                return new constructor(...args);
-            };
         }
         imports.teavmMath = Math;
     }

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

@@ -0,0 +1,129 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.jso.impl;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Predicate;
+import org.teavm.model.ClassReader;
+import org.teavm.model.MethodReader;
+import org.teavm.model.MethodReference;
+
+public class AliasCollector {
+    private AliasCollector() {
+    }
+
+    public static boolean isStaticMember(MethodReader method) {
+        return !isInstanceMember(method);
+    }
+
+    public static boolean isInstanceMember(MethodReader method) {
+        return method.getAnnotations().get(JSInstanceExpose.class.getName()) != null;
+    }
+
+    public static Members collectMembers(ClassReader classReader, Predicate<MethodReader> filter) {
+        var methods = new HashMap<String, MethodReference>();
+        var properties = new HashMap<String, PropertyInfo>();
+        MethodReference constructor = null;
+        for (var method : classReader.getMethods()) {
+            if (!filter.test(method)) {
+                continue;
+            }
+            var methodAlias = getPublicAlias(method);
+            if (methodAlias != null) {
+                switch (methodAlias.kind) {
+                    case METHOD:
+                        methods.put(methodAlias.name, method.getReference());
+                        break;
+                    case GETTER: {
+                        var propInfo = properties.computeIfAbsent(methodAlias.name, k -> new PropertyInfo());
+                        propInfo.getter = method.getReference();
+                        break;
+                    }
+                    case SETTER: {
+                        var propInfo = properties.computeIfAbsent(methodAlias.name, k -> new PropertyInfo());
+                        propInfo.setter = method.getReference();
+                        break;
+                    }
+                    case CONSTRUCTOR:
+                        constructor = method.getReference();
+                        break;
+                }
+            }
+        }
+        return new Members(methods, properties, constructor);
+    }
+
+    public static Alias getPublicAlias(MethodReader method) {
+        var annot = method.getAnnotations().get(JSMethodToExpose.class.getName());
+        if (annot != null) {
+            return new Alias(annot.getValue("name").getString(), AliasKind.METHOD);
+        }
+
+        annot = method.getAnnotations().get(JSGetterToExpose.class.getName());
+        if (annot != null) {
+            return new Alias(annot.getValue("name").getString(), AliasKind.GETTER);
+        }
+
+        annot = method.getAnnotations().get(JSSetterToExpose.class.getName());
+        if (annot != null) {
+            return new Alias(annot.getValue("name").getString(), AliasKind.SETTER);
+        }
+
+        annot = method.getAnnotations().get(JSConstructorToExpose.class.getName());
+        if (annot != null) {
+            return new Alias(null, AliasKind.CONSTRUCTOR);
+        }
+
+        return null;
+    }
+
+    public static class Members {
+        public final Map<String, MethodReference> methods;
+        public final Map<String, PropertyInfo> properties;
+        public final MethodReference constructor;
+
+        Members(Map<String, MethodReference> methods, Map<String, PropertyInfo> properties,
+                MethodReference constructor) {
+            this.methods = methods;
+            this.properties = properties;
+            this.constructor = constructor;
+        }
+    }
+
+
+    public static class PropertyInfo {
+        public MethodReference getter;
+        public MethodReference setter;
+    }
+
+    public static class Alias {
+        public final String name;
+        public final AliasKind kind;
+
+        Alias(String name, AliasKind kind) {
+            this.name = name;
+            this.kind = kind;
+        }
+    }
+
+    public enum AliasKind {
+        METHOD,
+        GETTER,
+        SETTER,
+        CONSTRUCTOR
+    }
+}

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

@@ -738,6 +738,7 @@ public final class JS {
 
     @GeneratedBy(JSNativeGenerator.class)
     @PluggableDependency(JSNativeInjector.class)
+    @Import(name = "asFunction", module = "teavmJso")
     public static native JSObject function(JSObject instance, JSObject property);
 
     @GeneratedBy(JSNativeGenerator.class)

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

@@ -15,9 +15,9 @@
  */
 package org.teavm.jso.impl;
 
+import static org.teavm.jso.impl.AliasCollector.collectMembers;
+import static org.teavm.jso.impl.AliasCollector.getPublicAlias;
 import java.util.HashMap;
-import java.util.Map;
-import java.util.function.Predicate;
 import org.teavm.backend.javascript.codegen.SourceWriter;
 import org.teavm.backend.javascript.rendering.RenderingManager;
 import org.teavm.backend.javascript.spi.MethodContributor;
@@ -47,7 +47,7 @@ class JSAliasRenderer implements RendererListener, MethodContributor {
     public void begin(RenderingManager context, BuildTarget buildTarget) {
         writer = context.getWriter();
         classSource = context.getClassSource();
-        typeHelper = new JSTypeHelper(context.getClassSource());
+        typeHelper = new JSTypeHelper(context.getOriginalClassSource());
         this.context = context;
     }
 
@@ -91,7 +91,7 @@ class JSAliasRenderer implements RendererListener, MethodContributor {
     }
 
     private boolean exportClassInstanceMembers(ClassReader classReader) {
-        var members = collectMembers(classReader, method -> !method.hasModifier(ElementModifier.STATIC));
+        var members = collectMembers(classReader, AliasCollector::isInstanceMember);
 
         var isJsClassImpl = typeHelper.isJavaScriptImplementation(classReader.getName());
         if (members.methods.isEmpty() && members.properties.isEmpty() && !isJsClassImpl) {
@@ -106,23 +106,25 @@ class JSAliasRenderer implements RendererListener, MethodContributor {
         }
 
         for (var aliasEntry : members.methods.entrySet()) {
-            if (classReader.getMethod(aliasEntry.getValue()) == null) {
+            if (classReader.getMethod(aliasEntry.getValue().getDescriptor()) == null) {
                 continue;
             }
             appendMethodAlias(aliasEntry.getKey());
-            writer.ws().append("=").ws().append("c.").appendVirtualMethod(aliasEntry.getValue())
+            writer.ws().append("=").ws().appendFunction("$rt_callWithReceiver").append("(")
-                    .append(";").softNewLine();
+                    .appendMethod(aliasEntry.getValue()).append(");").softNewLine();
         }
         for (var aliasEntry : members.properties.entrySet()) {
             var propInfo = aliasEntry.getValue();
-            if (propInfo.getter == null || classReader.getMethod(propInfo.getter) == null) {
+            if (propInfo.getter == null || classReader.getMethod(propInfo.getter.getDescriptor()) == null) {
                 continue;
             }
             appendPropertyAlias(aliasEntry.getKey());
-            writer.append("get:").ws().append("c.").appendVirtualMethod(propInfo.getter);
+            writer.append("get:").ws().appendFunction("$rt_callWithReceiver").append("(")
-            if (propInfo.setter != null && classReader.getMethod(propInfo.setter) != null) {
+                    .appendMethod(propInfo.getter).append(")");
+            if (propInfo.setter != null && classReader.getMethod(propInfo.setter.getDescriptor()) != null) {
                 writer.append(",").softNewLine();
-                writer.append("set:").ws().append("c.").appendVirtualMethod(propInfo.setter);
+                writer.append("set:").ws().appendFunction("$rt_callWithReceiver").append("(")
+                        .appendMethod(propInfo.setter).append(")");
             }
             writer.softNewLine().outdent().append("});").softNewLine();
         }
@@ -136,7 +138,7 @@ class JSAliasRenderer implements RendererListener, MethodContributor {
     }
 
     private boolean exportClassStaticMembers(ClassReader classReader, String name) {
-        var members = collectMembers(classReader, c -> c.hasModifier(ElementModifier.STATIC));
+        var members = collectMembers(classReader, AliasCollector::isStaticMember);
 
         if (members.methods.isEmpty() && members.properties.isEmpty()) {
             return false;
@@ -146,7 +148,7 @@ class JSAliasRenderer implements RendererListener, MethodContributor {
 
         for (var aliasEntry : members.methods.entrySet()) {
             appendMethodAlias(aliasEntry.getKey());
-            var fullRef = new MethodReference(classReader.getName(), aliasEntry.getValue());
+            var fullRef = aliasEntry.getValue();
             writer.ws().append("=").ws().appendMethod(fullRef).append(";").softNewLine();
         }
         for (var aliasEntry : members.properties.entrySet()) {
@@ -155,11 +157,11 @@ class JSAliasRenderer implements RendererListener, MethodContributor {
                 continue;
             }
             appendPropertyAlias(aliasEntry.getKey());
-            var fullGetter = new MethodReference(classReader.getName(), propInfo.getter);
+            var fullGetter = propInfo.getter;
             writer.append("get:").ws().appendMethod(fullGetter);
             if (propInfo.setter != null) {
                 writer.append(",").softNewLine();
-                var fullSetter = new MethodReference(classReader.getName(), propInfo.setter);
+                var fullSetter = propInfo.setter;
                 writer.append("set:").ws().appendMethod(fullSetter);
             }
             writer.softNewLine().outdent().append("});").softNewLine();
@@ -182,39 +184,6 @@ class JSAliasRenderer implements RendererListener, MethodContributor {
                 .ws().append("{").indent().softNewLine();
     }
 
-    private Members collectMembers(ClassReader classReader, Predicate<MethodReader> filter) {
-        var methods = new HashMap<String, MethodDescriptor>();
-        var properties = new HashMap<String, PropertyInfo>();
-        MethodDescriptor constructor = null;
-        for (var method : classReader.getMethods()) {
-            if (!filter.test(method)) {
-                continue;
-            }
-            var methodAlias = getPublicAlias(method);
-            if (methodAlias != null) {
-                switch (methodAlias.kind) {
-                    case METHOD:
-                        methods.put(methodAlias.name, method.getDescriptor());
-                        break;
-                    case GETTER: {
-                        var propInfo = properties.computeIfAbsent(methodAlias.name, k -> new PropertyInfo());
-                        propInfo.getter = method.getDescriptor();
-                        break;
-                    }
-                    case SETTER: {
-                        var propInfo = properties.computeIfAbsent(methodAlias.name, k -> new PropertyInfo());
-                        propInfo.setter = method.getDescriptor();
-                        break;
-                    }
-                    case CONSTRUCTOR:
-                        constructor = method.getDescriptor();
-                        break;
-                }
-            }
-        }
-        return new Members(methods, properties, constructor);
-    }
-
     private void exportModule() {
         var cls = classSource.get(context.getEntryPoint());
         for (var method : cls.getMethods()) {
@@ -222,7 +191,7 @@ class JSAliasRenderer implements RendererListener, MethodContributor {
                 continue;
             }
             var methodAlias = getPublicAlias(method);
-            if (methodAlias != null && methodAlias.kind == AliasKind.METHOD) {
+            if (methodAlias != null && methodAlias.kind == AliasCollector.AliasKind.METHOD) {
                 context.exportMethod(method.getReference(), methodAlias.name);
             }
         }
@@ -230,7 +199,7 @@ class JSAliasRenderer implements RendererListener, MethodContributor {
 
     private void exportClassFromModule(ClassReader cls, String functionName) {
         var name = getClassAliasName(cls);
-        var constructors = collectMembers(cls, method -> !method.hasModifier(ElementModifier.STATIC));
+        var constructors = collectMembers(cls, AliasCollector::isInstanceMember);
 
         var method = constructors.constructor;
         writer.append("function ").appendFunction(functionName).append("(");
@@ -245,7 +214,7 @@ class JSAliasRenderer implements RendererListener, MethodContributor {
         writer.append(")").ws().appendBlockStart();
         if (method != null) {
             writer.appendClass(cls.getName()).append(".call(this);").softNewLine();
-            writer.appendMethod(new MethodReference(cls.getName(), method)).append("(this");
+            writer.appendMethod(method).append("(this");
             for (var i = 0; i < method.parameterCount(); ++i) {
                 writer.append(",").ws().append("p" + i);
             }
@@ -293,31 +262,6 @@ class JSAliasRenderer implements RendererListener, MethodContributor {
         }
         return false;
     }
-
-    private Alias getPublicAlias(MethodReader method) {
-        var annot = method.getAnnotations().get(JSMethodToExpose.class.getName());
-        if (annot != null) {
-            return new Alias(annot.getValue("name").getString(), AliasKind.METHOD);
-        }
-
-        annot = method.getAnnotations().get(JSGetterToExpose.class.getName());
-        if (annot != null) {
-            return new Alias(annot.getValue("name").getString(), AliasKind.GETTER);
-        }
-
-        annot = method.getAnnotations().get(JSSetterToExpose.class.getName());
-        if (annot != null) {
-            return new Alias(annot.getValue("name").getString(), AliasKind.SETTER);
-        }
-
-        annot = method.getAnnotations().get(JSConstructorToExpose.class.getName());
-        if (annot != null) {
-            return new Alias(null, AliasKind.CONSTRUCTOR);
-        }
-
-        return null;
-    }
-
     private FieldReader getFunctorField(ClassReader cls) {
         return cls.getField("$$jso_functor$$");
     }
@@ -403,38 +347,5 @@ class JSAliasRenderer implements RendererListener, MethodContributor {
         return methodReader != null && getPublicAlias(methodReader) != null;
     }
 
-    private static class Members {
-        final Map<String, MethodDescriptor> methods;
-        final Map<String, PropertyInfo> properties;
-        final MethodDescriptor constructor;
 
-        Members(Map<String, MethodDescriptor> methods, Map<String, PropertyInfo> properties,
-                MethodDescriptor constructor) {
-            this.methods = methods;
-            this.properties = properties;
-            this.constructor = constructor;
-        }
-    }
-
-    private static class PropertyInfo {
-        MethodDescriptor getter;
-        MethodDescriptor setter;
-    }
-
-    private static class Alias {
-        final String name;
-        final AliasKind kind;
-
-        Alias(String name, AliasKind kind) {
-            this.name = name;
-            this.kind = kind;
-        }
-    }
-
-    private enum AliasKind {
-        METHOD,
-        GETTER,
-        SETTER,
-        CONSTRUCTOR
-    }
 }

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

@@ -0,0 +1,19 @@
+/*
+ *  Copyright 2024 konsoletyper.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.jso.impl;
+
+@interface JSBodyDelegate {
+}

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

@@ -80,20 +80,6 @@ import org.teavm.model.util.ProgramUtils;
 
 class JSClassProcessor {
     private static final String NO_SIDE_EFFECTS = NoSideEffects.class.getName();
-    private static final MethodReference WRAP = new MethodReference(JSWrapper.class, "wrap", Object.class,
-            Object.class);
-    private static final MethodReference MAYBE_WRAP = new MethodReference(JSWrapper.class, "maybeWrap", Object.class,
-            Object.class);
-    private static final MethodReference UNWRAP = new MethodReference(JSWrapper.class, "unwrap", Object.class,
-            JSObject.class);
-    private static final MethodReference MAYBE_UNWRAP = new MethodReference(JSWrapper.class, "maybeUnwrap",
-            Object.class, JSObject.class);
-    private static final MethodReference IS_JS = new MethodReference(JSWrapper.class, "isJs",
-            Object.class, boolean.class);
-    private static final MethodReference IS_PRIMITIVE = new MethodReference(JSWrapper.class, "isPrimitive",
-            Object.class, JSObject.class, boolean.class);
-    private static final MethodReference INSTANCE_OF = new MethodReference(JSWrapper.class, "instanceOf",
-            Object.class, JSObject.class, boolean.class);
     private final ClassReaderSource classSource;
     private final JSBodyRepository repository;
     private final JavaInvocationProcessor javaInvocationProcessor;
@@ -111,6 +97,7 @@ class JSClassProcessor {
     private JSImportAnnotationCache annotationCache;
     private ClassReader objectClass;
     private Predicate<String> classFilter = n -> true;
+    private boolean wasmGC;
 
     JSClassProcessor(ClassReaderSource classSource, JSTypeHelper typeHelper, JSBodyRepository repository,
             Diagnostics diagnostics, IncrementalDependencyRegistration incrementalCache, boolean strict) {
@@ -125,7 +112,11 @@ class JSClassProcessor {
         annotationCache = new JSImportAnnotationCache(classSource, diagnostics);
     }
 
-    public void setClassFilter(Predicate<String> classFilter) {
+    void setWasmGC(boolean wasmGC) {
+        this.wasmGC = wasmGC;
+    }
+
+    void setClassFilter(Predicate<String> classFilter) {
         this.classFilter = classFilter;
     }
 
@@ -286,8 +277,11 @@ class JSClassProcessor {
 
     void processProgram(MethodHolder methodToProcess) {
         setCurrentProgram(methodToProcess.getProgram());
-        types = new JSTypeInference(typeHelper, classSource, program, methodToProcess.getReference());
+        types = new JSTypeInference(typeHelper, classSource, program, methodToProcess.getReference(), wasmGC);
         types.ensure();
+        if (wasmGC) {
+            wrapJsPhis(methodToProcess.getReference());
+        }
         for (int i = 0; i < program.basicBlockCount(); ++i) {
             var block = program.basicBlockAt(i);
             for (var insn : block) {
@@ -355,6 +349,32 @@ class JSClassProcessor {
         }
     }
 
+    private void wrapJsPhis(MethodReference methodReference) {
+        var changed = false;
+        for (var block : program.getBasicBlocks()) {
+            for (var phi : block.getPhis()) {
+                if (types.typeOf(phi.getReceiver()) == JSType.MIXED) {
+                    for (var incoming : phi.getIncomings()) {
+                        if (types.typeOf(incoming.getValue()) == JSType.JS) {
+                            changed = true;
+                            var wrap = new InvokeInstruction();
+                            wrap.setType(InvocationType.SPECIAL);
+                            wrap.setMethod(new MethodReference(JSWrapper.class, "wrap", JSObject.class, Object.class));
+                            wrap.setArguments(incoming.getValue());
+                            wrap.setReceiver(program.createVariable());
+                            incoming.getSource().getLastInstruction().insertPrevious(wrap);
+                            incoming.setValue(wrap.getReceiver());
+                        }
+                    }
+                }
+            }
+        }
+        if (changed) {
+            types = new JSTypeInference(typeHelper, classSource, program, methodReference, wasmGC);
+            types.ensure();
+        }
+    }
+
     private void processInvokeArgs(InvokeInstruction invoke, MethodReader methodToInvoke) {
         if (methodToInvoke != null && methodToInvoke.getAnnotations().get(JSBody.class.getName()) != null) {
             return;
@@ -402,7 +422,7 @@ class JSClassProcessor {
         if (type == JSType.JS || type == JSType.MIXED) {
             var unwrap = new InvokeInstruction();
             unwrap.setType(InvocationType.SPECIAL);
-            unwrap.setMethod(type == JSType.MIXED ? MAYBE_UNWRAP : UNWRAP);
+            unwrap.setMethod(type == JSType.MIXED ? JSMethods.MAYBE_UNWRAP : JSMethods.UNWRAP);
             unwrap.setArguments(program.createVariable());
             unwrap.setReceiver(insn.getReceiver());
             unwrap.setLocation(insn.getLocation());
@@ -420,7 +440,7 @@ class JSClassProcessor {
         if (type == JSType.JS || type == JSType.MIXED) {
             var wrap = new InvokeInstruction();
             wrap.setType(InvocationType.SPECIAL);
-            wrap.setMethod(type == JSType.MIXED ? MAYBE_WRAP : WRAP);
+            wrap.setMethod(type == JSType.MIXED ? JSMethods.MAYBE_WRAP : JSMethods.WRAP);
             wrap.setArguments(insn.getValue());
             wrap.setReceiver(program.createVariable());
             wrap.setLocation(insn.getLocation());
@@ -563,7 +583,7 @@ class JSClassProcessor {
             if (isTransparent(targetClassName)) {
                 var invoke = new InvokeInstruction();
                 invoke.setType(InvocationType.SPECIAL);
-                invoke.setMethod(IS_JS);
+                invoke.setMethod(JSMethods.IS_JS);
                 invoke.setArguments(value);
                 invoke.setReceiver(receiver);
                 invoke.setLocation(location);
@@ -572,7 +592,9 @@ class JSClassProcessor {
                 var primitiveType = getPrimitiveType(targetClassName);
                 var invoke = new InvokeInstruction();
                 invoke.setType(InvocationType.SPECIAL);
-                invoke.setMethod(primitiveType != null ? IS_PRIMITIVE : INSTANCE_OF);
+                invoke.setMethod(primitiveType != null
+                        ? JSMethods.WRAPPER_IS_PRIMITIVE
+                        : JSMethods.WRAPPER_INSTANCE_OF);
                 var secondArg = primitiveType != null
                         ? marshaller.addJsString(primitiveType, location)
                         : marshaller.classRef(targetClassName, location);
@@ -648,7 +670,7 @@ class JSClassProcessor {
         }
         var wrap = new InvokeInstruction();
         wrap.setType(InvocationType.SPECIAL);
-        wrap.setMethod(varType == JSType.JS ? WRAP : MAYBE_WRAP);
+        wrap.setMethod(varType == JSType.JS ? JSMethods.WRAP : JSMethods.MAYBE_WRAP);
         wrap.setArguments(var);
         wrap.setReceiver(program.createVariable());
         wrap.setLocation(instruction.getLocation());
@@ -663,7 +685,7 @@ class JSClassProcessor {
         }
         var unwrap = new InvokeInstruction();
         unwrap.setType(InvocationType.SPECIAL);
-        unwrap.setMethod(varType == JSType.JAVA ? UNWRAP : MAYBE_UNWRAP);
+        unwrap.setMethod(varType == JSType.JAVA ? JSMethods.UNWRAP : JSMethods.MAYBE_UNWRAP);
         unwrap.setArguments(var);
         unwrap.setReceiver(program.createVariable());
         unwrap.setLocation(instruction.getLocation());
@@ -1187,6 +1209,7 @@ class JSClassProcessor {
             if (method.getAnnotations().get(NoSideEffects.class.getName()) != null) {
                 proxyMethod.getAnnotations().add(new AnnotationHolder(NoSideEffects.class.getName()));
             }
+            proxyMethod.getAnnotations().add(new AnnotationHolder(JSBodyDelegate.class.getName()));
             boolean inline = repository.inlineMethods.contains(methodRef);
             AnnotationHolder generatorAnnot = new AnnotationHolder(inline
                     ? DynamicInjector.class.getName() : DynamicGenerator.class.getName());

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

@@ -0,0 +1,19 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.jso.impl;
+
+@interface JSClassToExpose {
+}

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

@@ -17,23 +17,29 @@ package org.teavm.jso.impl;
 
 import org.teavm.dependency.AbstractDependencyListener;
 import org.teavm.dependency.DependencyAgent;
+import org.teavm.dependency.DependencyNode;
 import org.teavm.dependency.MethodDependency;
 import org.teavm.jso.JSExportClasses;
 import org.teavm.model.AnnotationReader;
 import org.teavm.model.CallLocation;
 import org.teavm.model.ClassReader;
-import org.teavm.model.ElementModifier;
 import org.teavm.model.MethodReader;
 import org.teavm.model.MethodReference;
 import org.teavm.model.ValueType;
 
 class JSDependencyListener extends AbstractDependencyListener {
     private JSBodyRepository repository;
+    private DependencyNode exceptions;
 
     JSDependencyListener(JSBodyRepository repository) {
         this.repository = repository;
     }
 
+    @Override
+    public void started(DependencyAgent agent) {
+        exceptions = agent.createNode();
+    }
+
     @Override
     public void methodReached(DependencyAgent agent, MethodDependency method) {
         MethodReference ref = method.getReference();
@@ -43,6 +49,22 @@ class JSDependencyListener extends AbstractDependencyListener {
                 agent.linkMethod(callbackMethod).addLocation(new CallLocation(ref)).use();
             }
         }
+        if (method.getMethod().getAnnotations().get(JSBodyDelegate.class.getName()) != null) {
+            exceptions.connect(method.getThrown());
+        }
+        if (method.getMethod().getOwnerName().equals(JS.class.getName())) {
+            switch (method.getMethod().getName()) {
+                case "invoke":
+                case "construct":
+                case "apply":
+                case "get":
+                case "getPure":
+                case "set":
+                case "setPure":
+                    exceptions.connect(method.getThrown());
+                    break;
+            }
+        }
     }
 
     @Override
@@ -62,10 +84,8 @@ class JSDependencyListener extends AbstractDependencyListener {
             if (exposeAnnot != null) {
                 MethodDependency methodDep = agent.linkMethod(method.getReference());
                 if (methodDep.getMethod() != null) {
-                    if (!methodDep.getMethod().hasModifier(ElementModifier.STATIC)) {
-                        methodDep.getVariable(0).propagate(agent.getType(className));
-                    }
                     methodDep.use();
+                    methodDep.getThrown().connect(exceptions);
                 }
             }
         }

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

@@ -0,0 +1,19 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.jso.impl;
+
+@interface JSInstanceExpose {
+}

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

@@ -0,0 +1,22 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.jso.impl;
+
+import org.teavm.jso.JSObject;
+
+public interface JSMarshallable {
+    JSObject marshallToJs();
+}

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

@@ -19,10 +19,11 @@ import java.util.Arrays;
 import org.teavm.jso.JSObject;
 import org.teavm.jso.core.JSArray;
 import org.teavm.jso.core.JSArrayReader;
+import org.teavm.model.MethodDescriptor;
 import org.teavm.model.MethodReference;
 import org.teavm.model.ValueType;
 
-final class JSMethods {
+public final class JSMethods {
     public static final MethodReference GET = new MethodReference(JS.class, "get", JSObject.class,
             JSObject.class, JSObject.class);
     public static final MethodReference GET_PURE = new MethodReference(JS.class, "getPure", JSObject.class,
@@ -143,6 +144,25 @@ final class JSMethods {
     private static final MethodReference[] CONSTRUCT_METHODS = new MethodReference[13];
     private static final MethodReference[] ARRAY_OF_METHODS = new MethodReference[13];
 
+    public static final MethodReference WRAP = new MethodReference(JSWrapper.class, "wrap", JSObject.class,
+            Object.class);
+    public static final MethodReference MAYBE_WRAP = new MethodReference(JSWrapper.class, "maybeWrap", Object.class,
+            Object.class);
+    public static final MethodReference UNWRAP = new MethodReference(JSWrapper.class, "unwrap", Object.class,
+            JSObject.class);
+    public static final MethodReference MAYBE_UNWRAP = new MethodReference(JSWrapper.class, "maybeUnwrap",
+            Object.class, JSObject.class);
+    public static final MethodReference IS_JS = new MethodReference(JSWrapper.class, "isJs",
+            Object.class, boolean.class);
+    public static final MethodReference WRAPPER_IS_PRIMITIVE = new MethodReference(JSWrapper.class, "isPrimitive",
+            Object.class, JSObject.class, boolean.class);
+    public static final MethodReference WRAPPER_INSTANCE_OF = new MethodReference(JSWrapper.class, "instanceOf",
+            Object.class, JSObject.class, boolean.class);
+
+    public static final String JS_MARSHALLABLE = JSMarshallable.class.getName();
+    public static final MethodDescriptor MARSHALL_TO_JS = new MethodDescriptor("marshallToJs", JS_OBJECT);
+    public static final MethodReference MARSHALL_TO_JS_REF = new MethodReference(JS_MARSHALLABLE, MARSHALL_TO_JS);
+
     static {
         for (int i = 0; i < INVOKE_METHODS.length; ++i) {
             var signature = new ValueType[i + 3];

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

@@ -46,12 +46,7 @@ public class JSOPlugin implements TeaVMPlugin {
         host.add(new JSExceptionsDependencyListener());
 
         var wrapperDependency = new JSWrapperDependency();
-        host.add(new MethodReference(JSWrapper.class, "jsToWrapper", JSObject.class, JSWrapper.class),
+        host.add(wrapperDependency);
-                wrapperDependency);
-        host.add(new MethodReference(JSWrapper.class, "dependencyJavaToJs", Object.class, JSObject.class),
-                wrapperDependency);
-        host.add(new MethodReference(JSWrapper.class, "dependencyJsToJava", JSObject.class, Object.class),
-                wrapperDependency);
 
         TeaVMPluginUtil.handleNatives(host, JS.class);
 
@@ -61,6 +56,7 @@ public class JSOPlugin implements TeaVMPlugin {
 
         if (wasmGCHost != null) {
             classTransformer.setClassFilter(n -> !n.startsWith("java."));
+            classTransformer.forWasmGC();
             WasmGCJso.install(host, wasmGCHost, repository);
         }
     }
@@ -90,6 +86,10 @@ public class JSOPlugin implements TeaVMPlugin {
                 wrapperGenerator);
         jsHost.add(new MethodReference(JSWrapper.class, "dependencyJsToJava", JSObject.class, Object.class),
                 wrapperGenerator);
+        jsHost.add(new MethodReference(JSWrapper.class, "marshallJavaToJs", Object.class, JSObject.class),
+                wrapperGenerator);
+        jsHost.add(new MethodReference(JSWrapper.class, "unmarshallJavaFromJs", JSObject.class, Object.class),
+                wrapperGenerator);
         jsHost.add(new MethodReference(JSWrapper.class, "isJava", Object.class, boolean.class),
                 wrapperGenerator);
         jsHost.add(new MethodReference(JSWrapper.class, "isJava", JSObject.class, boolean.class),

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

@@ -49,6 +49,7 @@ import org.teavm.model.MethodReference;
 import org.teavm.model.Program;
 import org.teavm.model.ValueType;
 import org.teavm.model.Variable;
+import org.teavm.model.instructions.CastInstruction;
 import org.teavm.model.instructions.ExitInstruction;
 import org.teavm.model.instructions.IntegerConstantInstruction;
 import org.teavm.model.instructions.InvocationType;
@@ -61,6 +62,7 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
     private ClassHierarchy hierarchy;
     private Map<String, ExposedClass> exposedClasses = new HashMap<>();
     private Predicate<String> classFilter = n -> true;
+    private boolean wasmGC;
 
     JSObjectClassTransformer(JSBodyRepository repository) {
         this.repository = repository;
@@ -70,6 +72,10 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
         this.classFilter = classFilter;
     }
 
+    void forWasmGC() {
+        wasmGC = true;
+    }
+
     @Override
     public void transformClass(ClassHolder cls, ClassHolderTransformerContext context) {
         this.hierarchy = context.getHierarchy();
@@ -77,6 +83,7 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
             typeHelper = new JSTypeHelper(hierarchy.getClassSource());
             processor = new JSClassProcessor(hierarchy.getClassSource(), typeHelper, repository,
                     context.getDiagnostics(), context.getIncrementalCache(), context.isStrict());
+            processor.setWasmGC(wasmGC);
             processor.setClassFilter(classFilter);
         }
         processor.processClass(cls);
@@ -114,6 +121,21 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
 
         exposeMethods(cls, exposedClass, context.getDiagnostics(), functorMethod);
         exportStaticMethods(cls, context.getDiagnostics());
+
+        if (typeHelper.isJavaScriptImplementation(cls.getName()) || !exposedClass.methods.isEmpty()) {
+            cls.getAnnotations().add(new AnnotationHolder(JSClassToExpose.class.getName()));
+        }
+
+        if (wasmGC && (!exposedClass.methods.isEmpty() || typeHelper.isJavaScriptClass(cls.getName()))) {
+            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())) {
+                cls.getInterfaces().add(JSMethods.JS_MARSHALLABLE);
+            }
+        }
     }
 
     private void exposeMethods(ClassHolder classHolder, ExposedClass classToExpose, Diagnostics diagnostics,
@@ -129,14 +151,20 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
             if (export.vararg) {
                 --paramCount;
             }
-            var exportedMethodSignature = new ValueType[paramCount + 1];
+            var exportedMethodSignature = new ValueType[paramCount + 2];
             Arrays.fill(exportedMethodSignature, JSMethods.JS_OBJECT);
+            if (methodRef.getReturnType() == ValueType.VOID) {
+                exportedMethodSignature[exportedMethodSignature.length - 1] = ValueType.VOID;
+            }
             MethodDescriptor exportedMethodDesc = new MethodDescriptor(method.getName() + "$exported$" + index++,
                     exportedMethodSignature);
             MethodHolder exportedMethod = new MethodHolder(exportedMethodDesc);
+            exportedMethod.getModifiers().add(ElementModifier.STATIC);
+            exportedMethod.getAnnotations().add(new AnnotationHolder(JSInstanceExpose.class.getName()));
             Program program = new Program();
             exportedMethod.setProgram(program);
             program.createVariable();
+            program.createVariable();
 
             BasicBlock basicBlock = program.createBasicBlock();
             List<Instruction> marshallInstructions = new ArrayList<>();
@@ -161,9 +189,24 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
             basicBlock.addAll(marshallInstructions);
             marshallInstructions.clear();
 
+            var unmarshalledInstance = new InvokeInstruction();
+            unmarshalledInstance.setType(InvocationType.SPECIAL);
+            unmarshalledInstance.setReceiver(program.createVariable());
+            unmarshalledInstance.setArguments(program.variableAt(1));
+            unmarshalledInstance.setMethod(new MethodReference(JSWrapper.class,
+                    "unmarshallJavaFromJs", JSObject.class, Object.class));
+            basicBlock.add(unmarshalledInstance);
+
+            var castInstance = new CastInstruction();
+            castInstance.setValue(unmarshalledInstance.getReceiver());
+            castInstance.setReceiver(program.createVariable());
+            castInstance.setWeak(true);
+            castInstance.setTargetType(ValueType.object(classHolder.getName()));
+            basicBlock.add(castInstance);
+
             InvokeInstruction invocation = new InvokeInstruction();
-            invocation.setType(InvocationType.VIRTUAL);
+            invocation.setType(method.getName().equals("<init>") ? InvocationType.SPECIAL : InvocationType.VIRTUAL);
-            invocation.setInstance(program.variableAt(0));
+            invocation.setInstance(castInstance.getReceiver());
             invocation.setMethod(methodRef);
             invocation.setArguments(variablesToPass);
             basicBlock.add(invocation);

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

@@ -24,12 +24,12 @@ import org.teavm.model.ClassReaderSource;
 import org.teavm.model.ElementModifier;
 import org.teavm.model.ValueType;
 
-class JSTypeHelper {
+public class JSTypeHelper {
     private ClassReaderSource classSource;
     private Map<String, Boolean> knownJavaScriptClasses = new HashMap<>();
     private Map<String, Boolean> knownJavaScriptImplementations = new HashMap<>();
 
-    JSTypeHelper(ClassReaderSource classSource) {
+    public JSTypeHelper(ClassReaderSource classSource) {
         this.classSource = classSource;
         knownJavaScriptClasses.put(JSObject.class.getName(), true);
     }

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

@@ -26,11 +26,14 @@ import org.teavm.model.instructions.InvocationType;
 class JSTypeInference extends BaseTypeInference<JSType> {
     private JSTypeHelper typeHelper;
     private ClassReaderSource classes;
+    private boolean wasmGC;
 
-    JSTypeInference(JSTypeHelper typeHelper, ClassReaderSource classes, Program program, MethodReference reference) {
+    JSTypeInference(JSTypeHelper typeHelper, ClassReaderSource classes, Program program, MethodReference reference,
+            boolean wasmGC) {
         super(program, reference);
         this.typeHelper = typeHelper;
         this.classes = classes;
+        this.wasmGC = wasmGC;
     }
 
     @Override
@@ -93,7 +96,7 @@ class JSTypeInference extends BaseTypeInference<JSType> {
         if (!methodRef.getReturnType().isObject(Object.class)) {
             return mapType(methodRef.getReturnType());
         }
-        return isJsMethod(methodRef) ? JSType.MIXED : JSType.JAVA;
+        return !wasmGC && isJsMethod(methodRef) ? JSType.MIXED : JSType.JAVA;
     }
 
     private boolean isJsMethod(MethodReference methodRef) {

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

@@ -87,6 +87,16 @@ class JSValueMarshaller {
             diagnostics.error(location, "Wrong functor: {{c0}}", type.getName());
             return var;
         }
+
+        var unwrapNative = new InvokeInstruction();
+        unwrapNative.setLocation(location.getSourceLocation());
+        unwrapNative.setType(InvocationType.SPECIAL);
+        unwrapNative.setMethod(JSMethods.UNWRAP);
+        unwrapNative.setArguments(var);
+        unwrapNative.setReceiver(program.createVariable());
+        replacement.add(unwrapNative);
+        var = unwrapNative.getReceiver();
+
         String name = type.getMethods().stream()
                 .filter(method -> method.hasModifier(ElementModifier.ABSTRACT))
                 .findFirst().get().getName();
@@ -142,6 +152,16 @@ class JSValueMarshaller {
                     replacement.add(unwrapNative);
                     return unwrapNative.getReceiver();
                 }
+                if (typeHelper.isJavaScriptClass(className) && jsType == JSType.JAVA) {
+                    var unwrapNative = new InvokeInstruction();
+                    unwrapNative.setLocation(location);
+                    unwrapNative.setType(InvocationType.SPECIAL);
+                    unwrapNative.setMethod(JSMethods.UNWRAP);
+                    unwrapNative.setArguments(var);
+                    unwrapNative.setReceiver(program.createVariable());
+                    replacement.add(unwrapNative);
+                    return unwrapNative.getReceiver();
+                }
                 return var;
             }
         }

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

@@ -15,6 +15,7 @@
  */
 package org.teavm.jso.impl;
 
+import org.teavm.interop.Import;
 import org.teavm.interop.NoSideEffects;
 import org.teavm.jso.JSBody;
 import org.teavm.jso.JSClass;
@@ -30,60 +31,61 @@ import org.teavm.jso.core.JSWeakMap;
 import org.teavm.jso.core.JSWeakRef;
 
 public final class JSWrapper {
-    private static final JSWeakMap<JSObject, JSTransparentInt> hashCodes = new JSWeakMap<>();
+    private static class Helper {
-    private static final JSWeakMap<JSObject, JSWeakRef<JSObject>> wrappers = JSWeakRef.isSupported()
+        private static final JSWeakMap<JSObject, JSTransparentInt> hashCodes = new JSWeakMap<>();
-            ? new JSWeakMap<>() : null;
+        private static final JSWeakMap<JSObject, JSWeakRef<JSObject>> wrappers = JSWeakRef.isSupported()
-    private static final JSMap<JSString, JSWeakRef<JSObject>> stringWrappers = JSWeakRef.isSupported()
+                ? new JSWeakMap<>() : null;
-            ? new JSMap<>() : null;
+        private static final JSMap<JSString, JSWeakRef<JSObject>> stringWrappers = JSWeakRef.isSupported()
-    private static final JSMap<JSNumber, JSWeakRef<JSObject>> numberWrappers = JSWeakRef.isSupported()
+                ? new JSMap<>() : null;
-            ? new JSMap<>() : null;
+        private static final JSMap<JSNumber, JSWeakRef<JSObject>> numberWrappers = JSWeakRef.isSupported()
-    private static JSWeakRef<JSObject> undefinedWrapper;
+                ? new JSMap<>() : null;
-    private static final JSFinalizationRegistry stringFinalizationRegistry;
+        private static JSWeakRef<JSObject> undefinedWrapper;
-    private static final JSFinalizationRegistry numberFinalizationRegistry;
+        private static JSFinalizationRegistry stringFinalizationRegistry;
-    private static int hashCodeGen;
+        private static JSFinalizationRegistry numberFinalizationRegistry;
+        private static int hashCodeGen;
+
+        static {
+            stringFinalizationRegistry = stringWrappers != null
+                    ? new JSFinalizationRegistry(token -> stringWrappers.delete((JSString) token))
+                    : null;
+            numberFinalizationRegistry = numberWrappers != null
+                    ? new JSFinalizationRegistry(token -> numberWrappers.delete((JSNumber) token))
+                    : null;
+        }
+    }
 
     public final JSObject js;
 
-    static {
-        stringFinalizationRegistry = stringWrappers != null
-                ? new JSFinalizationRegistry(token -> stringWrappers.delete((JSString) token))
-                : null;
-        numberFinalizationRegistry = numberWrappers != null
-                ? new JSFinalizationRegistry(token -> numberWrappers.delete((JSNumber) token))
-                : null;
-    }
-
     private JSWrapper(JSObject js) {
         this.js = js;
     }
 
-    public static Object wrap(Object o) {
+    public static Object wrap(JSObject o) {
         if (o == null) {
             return null;
         }
-        var js = directJavaToJs(o);
+        var type = JSObjects.typeOf(o);
-        var type = JSObjects.typeOf(js);
         var isObject = type.equals("object") || type.equals("function");
-        if (isObject && isJSImplementation(o)) {
+        var wrappers = Helper.wrappers;
-            return o;
-        }
         if (wrappers != null) {
             if (isObject) {
-                var existingRef = get(wrappers, js);
+                var existingRef = get(wrappers, o);
                 var existing = !isUndefined(existingRef) ? deref(existingRef) : JSUndefined.instance();
                 if (isUndefined(existing)) {
-                    var wrapper = new JSWrapper(js);
+                    var wrapper = new JSWrapper(o);
-                    set(wrappers, js, createWeakRef(wrapperToJs(wrapper)));
+                    set(wrappers, o, createWeakRef(wrapperToJs(wrapper)));
                     return wrapper;
                 } else {
                     return jsToWrapper(existing);
                 }
             } else if (type.equals("string")) {
-                var jsString = (JSString) js;
+                var jsString = (JSString) o;
+                var stringWrappers = Helper.stringWrappers;
+                var stringFinalizationRegistry = Helper.stringFinalizationRegistry;
                 var existingRef = get(stringWrappers, jsString);
                 var existing = !isUndefined(existingRef) ? deref(existingRef) : JSUndefined.instance();
                 if (isUndefined(existing)) {
-                    var wrapper = new JSWrapper(js);
+                    var wrapper = new JSWrapper(o);
                     var wrapperAsJs = wrapperToJs(wrapper);
                     set(stringWrappers, jsString, createWeakRef(wrapperAsJs));
                     register(stringFinalizationRegistry, wrapperAsJs, jsString);
@@ -92,11 +94,13 @@ public final class JSWrapper {
                     return jsToWrapper(existing);
                 }
             } else if (type.equals("number")) {
-                var jsNumber = (JSNumber) js;
+                var jsNumber = (JSNumber) o;
+                var numberWrappers = Helper.numberWrappers;
+                var numberFinalizationRegistry = Helper.numberFinalizationRegistry;
                 var existingRef = get(numberWrappers, jsNumber);
                 var existing = !isUndefined(existingRef) ? deref(existingRef) : JSUndefined.instance();
                 if (isUndefined(existing)) {
-                    var wrapper = new JSWrapper(js);
+                    var wrapper = new JSWrapper(o);
                     var wrapperAsJs = wrapperToJs(wrapper);
                     set(numberWrappers, jsNumber, createWeakRef(wrapperAsJs));
                     register(numberFinalizationRegistry, wrapperAsJs, jsNumber);
@@ -105,19 +109,19 @@ public final class JSWrapper {
                     return jsToWrapper(existing);
                 }
             } else if (type.equals("undefined")) {
-                var existingRef = undefinedWrapper;
+                var existingRef = Helper.undefinedWrapper;
                 var existing = existingRef != null ? deref(existingRef) : JSUndefined.instance();
                 if (isUndefined(existing)) {
-                    var wrapper = new JSWrapper(js);
+                    var wrapper = new JSWrapper(o);
                     var wrapperAsJs = wrapperToJs(wrapper);
-                    undefinedWrapper = createWeakRef(wrapperAsJs);
+                    Helper.undefinedWrapper = createWeakRef(wrapperAsJs);
                     return wrapper;
                 } else {
                     return jsToWrapper(existing);
                 }
             }
         }
-        return new JSWrapper(js);
+        return new JSWrapper(o);
     }
 
     @JSBody(params = "target", script = "return new WeakRef(target);")
@@ -152,14 +156,18 @@ public final class JSWrapper {
 
     @NoSideEffects
     public static Object maybeWrap(Object o) {
-        return o == null || isJava(o) ? o : wrap(o);
+        return o == null || isJava(o) ? o : wrap(directJavaToJs(o));
     }
 
     @NoSideEffects
     public static native JSObject directJavaToJs(Object obj);
 
     @NoSideEffects
-    public static native Object directJsToJava(JSObject obj);
+    public static native JSObject marshallJavaToJs(Object obj);
+
+    @NoSideEffects
+    @Import(name = "unwrapJavaObject", module = "teavmJso")
+    public static native Object unmarshallJavaFromJs(JSObject obj);
 
     @NoSideEffects
     public static native JSObject dependencyJavaToJs(Object obj);
@@ -186,14 +194,14 @@ public final class JSWrapper {
         if (o == null) {
             return null;
         }
-        return isJSImplementation(o) ? directJavaToJs(o) : ((JSWrapper) o).js;
+        return isJSImplementation(o) ? marshallJavaToJs(o) : ((JSWrapper) o).js;
     }
 
     public static JSObject maybeUnwrap(Object o) {
         if (o == null) {
             return null;
         }
-        return isJava(o) ? unwrap(o) : directJavaToJs(o);
+        return isJava(o) ? unwrap(o) : marshallJavaToJs(o);
     }
 
     public static JSObject javaToJs(Object o) {
@@ -207,7 +215,7 @@ public final class JSWrapper {
         if (o == null) {
             return null;
         }
-        return !isJava(o) ? wrap(directJsToJava(o)) : dependencyJsToJava(o);
+        return !isJava(o) ? wrap(o) : dependencyJsToJava(o);
     }
 
     public static boolean isJs(Object o) {
@@ -229,10 +237,10 @@ public final class JSWrapper {
     public int hashCode() {
         var type = JSObjects.typeOf(js);
         if (type.equals("object") || type.equals("symbol") || type.equals("function")) {
-            var code = hashCodes.get(js);
+            var code = Helper.hashCodes.get(js);
             if (isUndefined(code)) {
-                code = JSTransparentInt.valueOf(++hashCodeGen);
+                code = JSTransparentInt.valueOf(++Helper.hashCodeGen);
-                hashCodes.set(js, code);
+                Helper.hashCodes.set(js, code);
             }
             return code.intValue();
         } else if (type.equals("number")) {

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

@@ -15,33 +15,43 @@
  */
 package org.teavm.jso.impl;
 
+import org.teavm.dependency.AbstractDependencyListener;
 import org.teavm.dependency.DependencyAgent;
 import org.teavm.dependency.DependencyNode;
-import org.teavm.dependency.DependencyPlugin;
 import org.teavm.dependency.MethodDependency;
 
-public class JSWrapperDependency implements DependencyPlugin {
+public class JSWrapperDependency extends AbstractDependencyListener {
     private DependencyNode externalClassesNode;
 
     @Override
-    public void methodReached(DependencyAgent agent, MethodDependency method) {
+    public void started(DependencyAgent agent) {
-        switch (method.getMethod().getName()) {
+        externalClassesNode = agent.createNode();
-            case "jsToWrapper":
+    }
-                method.getResult().propagate(agent.getType(JSWrapper.class.getName()));
+
-                break;
+    @Override
-            case "dependencyJavaToJs":
+    public void classReached(DependencyAgent agent, String className) {
-                method.getVariable(1).connect(getExternalClassesNode(agent));
+        var cls = agent.getClassSource().get(className);
-                break;
+        if (cls.getAnnotations().get(JSClassToExpose.class.getName()) != null) {
-            case "dependencyJsToJava":
+            externalClassesNode.propagate(agent.getType(className));
-                getExternalClassesNode(agent).connect(method.getResult());
-                break;
         }
     }
 
-    private DependencyNode getExternalClassesNode(DependencyAgent agent) {
+    @Override
-        if (externalClassesNode == null) {
+    public void methodReached(DependencyAgent agent, MethodDependency method) {
-            externalClassesNode = agent.createNode();
+        if (method.getMethod().getOwnerName().equals(JSWrapper.class.getName())) {
+            switch (method.getMethod().getName()) {
+                case "jsToWrapper":
+                    method.getResult().propagate(agent.getType(JSWrapper.class.getName()));
+                    break;
+                case "dependencyJavaToJs":
+                case "marshallJavaToJs":
+                    method.getVariable(1).connect(externalClassesNode);
+                    break;
+                case "dependencyJsToJava":
+                case "unmarshallJavaFromJs":
+                    externalClassesNode.connect(method.getResult());
+                    break;
+            }
         }
-        return externalClassesNode;
     }
 }

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

@@ -34,6 +34,8 @@ public class JSWrapperGenerator implements Injector, DependencyPlugin {
             case "directJsToJava":
             case "dependencyJavaToJs":
             case "dependencyJsToJava":
+            case "marshallJavaToJs":
+            case "unmarshallJavaFromJs":
             case "wrapperToJs":
             case "jsToWrapper":
                 context.writeExpr(context.getArgument(0), context.getPrecedence());

jso/impl/src/main/java/org/teavm/jso/impl/wasmgc/WasmGCBodyIntrinsic.java

@@ -20,35 +20,42 @@ import org.teavm.backend.wasm.intrinsics.gc.WasmGCIntrinsic;
 import org.teavm.backend.wasm.intrinsics.gc.WasmGCIntrinsicContext;
 import org.teavm.backend.wasm.model.WasmGlobal;
 import org.teavm.backend.wasm.model.expression.WasmCall;
+import org.teavm.backend.wasm.model.expression.WasmDrop;
 import org.teavm.backend.wasm.model.expression.WasmExpression;
 import org.teavm.backend.wasm.model.expression.WasmGetGlobal;
 import org.teavm.jso.impl.JSBodyEmitter;
+import org.teavm.model.ValueType;
 
 class WasmGCBodyIntrinsic implements WasmGCIntrinsic {
     private JSBodyEmitter emitter;
     private boolean inlined;
-    private WasmGCBodyGenerator bodyGenerator;
+    private WasmGCJsoCommonGenerator commonGen;
     private WasmGlobal global;
     private WasmGCJSFunctions jsFunctions;
 
-    WasmGCBodyIntrinsic(JSBodyEmitter emitter, boolean inlined, WasmGCBodyGenerator bodyGenerator,
+    WasmGCBodyIntrinsic(JSBodyEmitter emitter, boolean inlined, WasmGCJsoCommonGenerator commonGen,
             WasmGCJSFunctions jsFunctions) {
         this.emitter = emitter;
         this.inlined = inlined;
-        this.bodyGenerator = bodyGenerator;
+        this.commonGen = commonGen;
         this.jsFunctions = jsFunctions;
     }
 
     @Override
     public WasmExpression apply(InvocationExpr invocation, WasmGCIntrinsicContext context) {
+        var jsoContext = WasmGCJsoContext.wrap(context);
         if (global == null) {
-            global = bodyGenerator.addBody(context, emitter, inlined);
+            global = commonGen.addJSBody(jsoContext, emitter, inlined);
         }
-        var call = new WasmCall(jsFunctions.getFunctionCaller(context, invocation.getArguments().size()));
+        var call = new WasmCall(jsFunctions.getFunctionCaller(jsoContext, invocation.getArguments().size()));
         call.getArguments().add(new WasmGetGlobal(global));
         for (var arg : invocation.getArguments()) {
             call.getArguments().add(context.generate(arg));
         }
-        return call;
+        WasmExpression result = call;
+        if (invocation.getMethod().getReturnType() == ValueType.VOID) {
+            result = new WasmDrop(result);
+        }
+        return result;
     }
 }

jso/impl/src/main/java/org/teavm/jso/impl/wasmgc/WasmGCJSBodyRenderer.java

@@ -24,12 +24,13 @@ import org.teavm.model.MethodReference;
 class WasmGCJSBodyRenderer implements WasmGCIntrinsicFactory {
     private JSBodyRepository repository;
     private WasmGCJSFunctions jsFunctions;
-    private WasmGCBodyGenerator bodyGenerator;
+    private WasmGCJsoCommonGenerator commonGen;
 
-    WasmGCJSBodyRenderer(JSBodyRepository repository) {
+    WasmGCJSBodyRenderer(JSBodyRepository repository, WasmGCJSFunctions jsFunctions,
+            WasmGCJsoCommonGenerator commonGen) {
         this.repository = repository;
-        jsFunctions = new WasmGCJSFunctions();
+        this.jsFunctions = jsFunctions;
-        bodyGenerator = new WasmGCBodyGenerator(jsFunctions);
+        this.commonGen = commonGen;
     }
 
     @Override
@@ -39,6 +40,6 @@ class WasmGCJSBodyRenderer implements WasmGCIntrinsicFactory {
             return null;
         }
         var inlined = repository.inlineMethods.contains(emitter.method());
-        return new WasmGCBodyIntrinsic(emitter, inlined, bodyGenerator, jsFunctions);
+        return new WasmGCBodyIntrinsic(emitter, inlined, commonGen, jsFunctions);
     }
 }

jso/impl/src/main/java/org/teavm/jso/impl/wasmgc/WasmGCJSFunctions.java

@@ -16,7 +16,6 @@
 package org.teavm.jso.impl.wasmgc;
 
 import java.util.Arrays;
-import org.teavm.backend.wasm.intrinsics.gc.WasmGCIntrinsicContext;
 import org.teavm.backend.wasm.model.WasmFunction;
 import org.teavm.backend.wasm.model.WasmType;
 
@@ -24,7 +23,7 @@ class WasmGCJSFunctions {
     private WasmFunction[] constructors = new WasmFunction[32];
     private WasmFunction[] callers = new WasmFunction[32];
 
-    WasmFunction getFunctionConstructor(WasmGCIntrinsicContext context, int index) {
+    WasmFunction getFunctionConstructor(WasmGCJsoContext context, int index) {
         var function = constructors[index];
         if (function == null) {
             var extern = WasmType.SpecialReferenceKind.EXTERN.asNonNullType();
@@ -41,7 +40,7 @@ class WasmGCJSFunctions {
         return function;
     }
 
-    WasmFunction getFunctionCaller(WasmGCIntrinsicContext context, int index) {
+    WasmFunction getFunctionCaller(WasmGCJsoContext context, int index) {
         var function = callers[index];
         if (function == null) {
             var paramTypes = new WasmType[index + 1];

jso/impl/src/main/java/org/teavm/jso/impl/wasmgc/WasmGCJSTypeMapper.java

@@ -19,14 +19,14 @@ import org.teavm.backend.wasm.generate.gc.classes.WasmGCCustomTypeMapper;
 import org.teavm.backend.wasm.generate.gc.classes.WasmGCCustomTypeMapperFactory;
 import org.teavm.backend.wasm.generate.gc.classes.WasmGCCustomTypeMapperFactoryContext;
 import org.teavm.backend.wasm.model.WasmType;
-import org.teavm.jso.JSObject;
+import org.teavm.jso.impl.JSTypeHelper;
-import org.teavm.jso.core.JSArray;
 
 class WasmGCJSTypeMapper implements WasmGCCustomTypeMapper, WasmGCCustomTypeMapperFactory {
+    private JSTypeHelper typeHelper;
+
     @Override
     public WasmType map(String className) {
-        if (className.equals(JSObject.class.getName())
+        if (typeHelper.isJavaScriptClass(className)) {
-                || className.equals(JSArray.class.getName())) {
             return WasmType.Reference.EXTERN;
         }
         return null;
@@ -34,6 +34,7 @@ class WasmGCJSTypeMapper implements WasmGCCustomTypeMapper, WasmGCCustomTypeMapp
 
     @Override
     public WasmGCCustomTypeMapper createTypeMapper(WasmGCCustomTypeMapperFactoryContext context) {
+        this.typeHelper = new JSTypeHelper(context.originalClasses());
         return this;
     }
 }

jso/impl/src/main/java/org/teavm/jso/impl/wasmgc/WasmGCJSWrapperTransformer.java

@@ -0,0 +1,54 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.jso.impl.wasmgc;
+
+import org.teavm.jso.JSObject;
+import org.teavm.jso.impl.JSMarshallable;
+import org.teavm.jso.impl.JSWrapper;
+import org.teavm.model.ClassHolder;
+import org.teavm.model.ClassHolderTransformer;
+import org.teavm.model.ClassHolderTransformerContext;
+import org.teavm.model.ElementModifier;
+import org.teavm.model.MethodDescriptor;
+import org.teavm.model.MethodHolder;
+import org.teavm.model.ValueType;
+import org.teavm.model.emit.ProgramEmitter;
+
+class WasmGCJSWrapperTransformer implements ClassHolderTransformer {
+    @Override
+    public void transformClass(ClassHolder cls, ClassHolderTransformerContext context) {
+        if (cls.getName().equals(JSWrapper.class.getName())) {
+            transformMarshallMethod(cls.getMethod(new MethodDescriptor("marshallJavaToJs", Object.class,
+                    JSObject.class)), context);
+            transformIsJsImplementation(cls.getMethod(new MethodDescriptor("isJSImplementation",
+                    Object.class, boolean.class)), context);
+        }
+    }
+
+    private void transformMarshallMethod(MethodHolder method, ClassHolderTransformerContext context) {
+        method.getModifiers().remove(ElementModifier.NATIVE);
+        var pe = ProgramEmitter.create(method, context.getHierarchy());
+        var obj = pe.var(1, Object.class);
+        obj.cast(JSMarshallable.class).invokeVirtual("marshallToJs", JSObject.class).returnValue();
+    }
+
+    private void transformIsJsImplementation(MethodHolder method, ClassHolderTransformerContext context) {
+        method.getModifiers().remove(ElementModifier.NATIVE);
+        var pe = ProgramEmitter.create(method, context.getHierarchy());
+        var obj = pe.var(1, JSObject.class);
+        obj.instanceOf(ValueType.parse(JSMarshallable.class)).returnValue();
+    }
+}

jso/impl/src/main/java/org/teavm/jso/impl/wasmgc/WasmGCJso.java

@@ -28,8 +28,12 @@ public final class WasmGCJso {
 
     public static void install(TeaVMHost host, TeaVMWasmGCHost wasmGCHost, JSBodyRepository jsBodyRepository) {
         host.add(new WasmGCJSDependencies());
+        host.add(new WasmGCJSWrapperTransformer());
+        var jsFunctions = new WasmGCJSFunctions();
+        var commonGen = new WasmGCJsoCommonGenerator(jsFunctions);
         wasmGCHost.addCustomTypeMapperFactory(new WasmGCJSTypeMapper());
-        wasmGCHost.addIntrinsicFactory(new WasmGCJSBodyRenderer(jsBodyRepository));
+        wasmGCHost.addIntrinsicFactory(new WasmGCJSBodyRenderer(jsBodyRepository, jsFunctions, commonGen));
+        wasmGCHost.addGeneratorFactory(new WasmGCMarshallMethodGeneratorFactory(commonGen));
 
         var jsIntrinsic = new WasmGCJSIntrinsic();
         wasmGCHost.addIntrinsic(new MethodReference(JS.class, "wrap", String.class, JSObject.class), jsIntrinsic);

jso/impl/src/main/java/org/teavm/jso/impl/wasmgc/WasmGCJsoCommonGenerator.java

@@ -20,11 +20,11 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Consumer;
 import org.teavm.backend.javascript.rendering.AstWriter;
-import org.teavm.backend.wasm.intrinsics.gc.WasmGCIntrinsicContext;
 import org.teavm.backend.wasm.model.WasmFunction;
 import org.teavm.backend.wasm.model.WasmGlobal;
 import org.teavm.backend.wasm.model.WasmType;
 import org.teavm.backend.wasm.model.expression.WasmCall;
+import org.teavm.backend.wasm.model.expression.WasmExpression;
 import org.teavm.backend.wasm.model.expression.WasmGetGlobal;
 import org.teavm.backend.wasm.model.expression.WasmNullConstant;
 import org.teavm.backend.wasm.model.expression.WasmSetGlobal;
@@ -32,16 +32,16 @@ import org.teavm.jso.impl.JSBodyAstEmitter;
 import org.teavm.jso.impl.JSBodyBloatedEmitter;
 import org.teavm.jso.impl.JSBodyEmitter;
 
-class WasmGCBodyGenerator {
+class WasmGCJsoCommonGenerator {
     private WasmGCJSFunctions jsFunctions;
     private boolean initialized;
     private List<Consumer<WasmFunction>> initializerParts = new ArrayList<>();
 
-    WasmGCBodyGenerator(WasmGCJSFunctions jsFunctions) {
+    WasmGCJsoCommonGenerator(WasmGCJSFunctions jsFunctions) {
         this.jsFunctions = jsFunctions;
     }
 
-    private void initialize(WasmGCIntrinsicContext context) {
+    private void initialize(WasmGCJsoContext context) {
         if (initialized) {
             return;
         }
@@ -49,14 +49,17 @@ class WasmGCBodyGenerator {
         context.addToInitializer(this::writeToInitializer);
     }
 
-
     private void writeToInitializer(WasmFunction function) {
         for (var part : initializerParts) {
             part.accept(function);
         }
     }
 
-    WasmGlobal addBody(WasmGCIntrinsicContext context, JSBodyEmitter emitter, boolean inlined) {
+    void addInitializerPart(Consumer<WasmFunction> part) {
+        initializerParts.add(part);
+    }
+
+    WasmGlobal addJSBody(WasmGCJsoContext context, JSBodyEmitter emitter, boolean inlined) {
         initialize(context);
         var paramCount = emitter.method().parameterCount();
         if (!emitter.isStatic()) {
@@ -87,9 +90,7 @@ class WasmGCBodyGenerator {
             throw new IllegalArgumentException();
         }
 
-        var constructor = new WasmCall(jsFunctions.getFunctionConstructor(context,
+        var constructor = new WasmCall(jsFunctions.getFunctionConstructor(context, paramCount));
-                paramCount));
-        var stringToJs = context.functions().forStaticMethod(STRING_TO_JS);
         var paramNames = new ArrayList<String>();
         if (!emitter.isStatic()) {
             paramNames.add("__this__");
@@ -97,12 +98,20 @@ class WasmGCBodyGenerator {
         paramNames.addAll(List.of(emitter.parameterNames()));
         for (var parameter : paramNames) {
             var paramName = new WasmGetGlobal(context.strings().getStringConstant(parameter).global);
-            constructor.getArguments().add(new WasmCall(stringToJs, paramName));
+            constructor.getArguments().add(stringToJs(context, paramName));
         }
         var functionBody = new WasmGetGlobal(context.strings().getStringConstant(body).global);
-        constructor.getArguments().add(new WasmCall(stringToJs, functionBody));
+        constructor.getArguments().add(stringToJs(context, functionBody));
         initializerParts.add(initializer -> initializer.getBody().add(new WasmSetGlobal(global, constructor)));
 
         return global;
     }
+
+    private WasmFunction stringToJsFunction(WasmGCJsoContext context) {
+        return context.functions().forStaticMethod(STRING_TO_JS);
+    }
+
+    WasmExpression stringToJs(WasmGCJsoContext context, WasmExpression str) {
+        return new WasmCall(stringToJsFunction(context), str);
+    }
 }

jso/impl/src/main/java/org/teavm/jso/impl/wasmgc/WasmGCJsoContext.java

@@ -0,0 +1,108 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.jso.impl.wasmgc;
+
+import java.util.function.Consumer;
+import org.teavm.backend.wasm.BaseWasmFunctionRepository;
+import org.teavm.backend.wasm.WasmFunctionTypes;
+import org.teavm.backend.wasm.generate.gc.WasmGCNameProvider;
+import org.teavm.backend.wasm.generate.gc.strings.WasmGCStringProvider;
+import org.teavm.backend.wasm.generators.gc.WasmGCCustomGeneratorContext;
+import org.teavm.backend.wasm.intrinsics.gc.WasmGCIntrinsicContext;
+import org.teavm.backend.wasm.model.WasmFunction;
+import org.teavm.backend.wasm.model.WasmModule;
+
+interface WasmGCJsoContext {
+    WasmModule module();
+
+    WasmFunctionTypes functionTypes();
+
+    BaseWasmFunctionRepository functions();
+
+    WasmGCNameProvider names();
+
+    WasmGCStringProvider strings();
+
+    void addToInitializer(Consumer<WasmFunction> initializerContributor);
+
+    static WasmGCJsoContext wrap(WasmGCIntrinsicContext context) {
+        return new WasmGCJsoContext() {
+            @Override
+            public WasmModule module() {
+                return context.module();
+            }
+
+            @Override
+            public WasmFunctionTypes functionTypes() {
+                return context.functionTypes();
+            }
+
+            @Override
+            public BaseWasmFunctionRepository functions() {
+                return context.functions();
+            }
+
+            @Override
+            public WasmGCNameProvider names() {
+                return context.names();
+            }
+
+            @Override
+            public WasmGCStringProvider strings() {
+                return context.strings();
+            }
+
+            @Override
+            public void addToInitializer(Consumer<WasmFunction> initializerContributor) {
+                context.addToInitializer(initializerContributor);
+            }
+        };
+    }
+
+    static WasmGCJsoContext wrap(WasmGCCustomGeneratorContext context) {
+        return new WasmGCJsoContext() {
+            @Override
+            public WasmModule module() {
+                return context.module();
+            }
+
+            @Override
+            public WasmFunctionTypes functionTypes() {
+                return context.functionTypes();
+            }
+
+            @Override
+            public BaseWasmFunctionRepository functions() {
+                return context.functions();
+            }
+
+            @Override
+            public WasmGCNameProvider names() {
+                return context.names();
+            }
+
+            @Override
+            public WasmGCStringProvider strings() {
+                return context.strings();
+            }
+
+            @Override
+            public void addToInitializer(Consumer<WasmFunction> initializerContributor) {
+                context.addToInitializer(initializerContributor);
+            }
+        };
+    }
+}

jso/impl/src/main/java/org/teavm/jso/impl/wasmgc/WasmGCMarshallMethodGenerator.java

@@ -0,0 +1,161 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.jso.impl.wasmgc;
+
+import java.util.ArrayList;
+import org.teavm.backend.wasm.generators.gc.WasmGCCustomGenerator;
+import org.teavm.backend.wasm.generators.gc.WasmGCCustomGeneratorContext;
+import org.teavm.backend.wasm.model.WasmFunction;
+import org.teavm.backend.wasm.model.WasmGlobal;
+import org.teavm.backend.wasm.model.WasmLocal;
+import org.teavm.backend.wasm.model.WasmType;
+import org.teavm.backend.wasm.model.expression.WasmCall;
+import org.teavm.backend.wasm.model.expression.WasmExpression;
+import org.teavm.backend.wasm.model.expression.WasmFunctionReference;
+import org.teavm.backend.wasm.model.expression.WasmGetGlobal;
+import org.teavm.backend.wasm.model.expression.WasmGetLocal;
+import org.teavm.backend.wasm.model.expression.WasmNullConstant;
+import org.teavm.backend.wasm.model.expression.WasmSetGlobal;
+import org.teavm.jso.impl.AliasCollector;
+import org.teavm.model.ClassReader;
+import org.teavm.model.MethodReference;
+import org.teavm.model.ValueType;
+
+class WasmGCMarshallMethodGenerator implements WasmGCCustomGenerator {
+    private WasmGCJsoCommonGenerator commonGen;
+    private WasmFunction javaObjectToJSFunction;
+    private WasmFunction createClassFunction;
+    private WasmFunction defineMethodFunction;
+    private WasmFunction definePropertyFunction;
+
+    WasmGCMarshallMethodGenerator(WasmGCJsoCommonGenerator commonGen) {
+        this.commonGen = commonGen;
+    }
+
+    @Override
+    public void apply(MethodReference method, WasmFunction function, WasmGCCustomGeneratorContext context) {
+        var jsoContext = WasmGCJsoContext.wrap(context);
+
+        var thisLocal = new WasmLocal(context.typeMapper().mapType(ValueType.object(method.getClassName())), "this");
+        function.add(thisLocal);
+
+        var cls = context.classes().get(method.getClassName());
+        var jsClassGlobal = defineClass(jsoContext, cls);
+        var wrapperFunction = javaObjectToJSFunction(context);
+        function.getBody().add(new WasmCall(wrapperFunction, new WasmGetLocal(thisLocal),
+                new WasmGetGlobal(jsClassGlobal)));
+    }
+
+    private WasmFunction javaObjectToJSFunction(WasmGCCustomGeneratorContext context) {
+        if (javaObjectToJSFunction == null) {
+            javaObjectToJSFunction = new WasmFunction(context.functionTypes().of(WasmType.Reference.EXTERN,
+                    context.typeMapper().mapType(ValueType.parse(Object.class)), WasmType.Reference.EXTERN));
+            javaObjectToJSFunction.setName(context.names().topLevel("teavm.jso@javaObjectToJS"));
+            javaObjectToJSFunction.setImportName("javaObjectToJS");
+            javaObjectToJSFunction.setImportModule("teavmJso");
+            context.module().functions.add(javaObjectToJSFunction);
+        }
+        return javaObjectToJSFunction;
+    }
+
+    WasmGlobal defineClass(WasmGCJsoContext context, ClassReader cls) {
+        var name = context.names().topLevel(context.names().suggestForClass(cls.getName()));
+        var global = new WasmGlobal(name, WasmType.Reference.EXTERN, new WasmNullConstant(WasmType.Reference.EXTERN));
+        context.module().globals.add(global);
+
+        var expressions = new ArrayList<WasmExpression>();
+        var className = context.strings().getStringConstant(cls.getName());
+        var jsClassName = commonGen.stringToJs(context, new WasmGetGlobal(className.global));
+        var createClass = new WasmCall(createClassFunction(context), jsClassName);
+        expressions.add(new WasmSetGlobal(global, createClass));
+
+        var members = AliasCollector.collectMembers(cls, AliasCollector::isInstanceMember);
+        for (var aliasEntry : members.methods.entrySet()) {
+            if (!aliasEntry.getValue().getClassName().equals(cls.getName())) {
+                continue;
+            }
+            var fn = context.functions().forStaticMethod(aliasEntry.getValue());
+            fn.setReferenced(true);
+            var methodName = context.strings().getStringConstant(aliasEntry.getKey());
+            var jsMethodName = commonGen.stringToJs(context, new WasmGetGlobal(methodName.global));
+            var defineMethod = new WasmCall(defineMethodFunction(context), new WasmGetGlobal(global),
+                    jsMethodName, new WasmFunctionReference(fn));
+            expressions.add(defineMethod);
+        }
+
+        for (var aliasEntry : members.properties.entrySet()) {
+            var property = aliasEntry.getValue();
+            if (!property.getter.getClassName().equals(cls.getName())) {
+                continue;
+            }
+            var getter = context.functions().forStaticMethod(property.getter);
+            getter.setReferenced(true);
+            WasmFunction setter = null;
+            if (property.setter != null) {
+                setter = context.functions().forStaticMethod(property.setter);
+                setter.setReferenced(true);
+            }
+            var setterRef = setter != null
+                    ? new WasmFunctionReference(setter)
+                    : new WasmNullConstant(WasmType.Reference.FUNC);
+            var methodName = context.strings().getStringConstant(aliasEntry.getKey());
+            var jsMethodName = commonGen.stringToJs(context, new WasmGetGlobal(methodName.global));
+            var defineProperty = new WasmCall(definePropertyFunction(context), new WasmGetGlobal(global),
+                    jsMethodName, new WasmFunctionReference(getter), setterRef);
+            expressions.add(defineProperty);
+        }
+
+        context.addToInitializer(f -> f.getBody().addAll(expressions));
+        return global;
+    }
+
+    private WasmFunction createClassFunction(WasmGCJsoContext context) {
+        if (createClassFunction == null) {
+            createClassFunction = new WasmFunction(context.functionTypes().of(WasmType.Reference.EXTERN,
+                    WasmType.Reference.EXTERN));
+            createClassFunction.setName(context.names().suggestForClass("teavm.jso@createClass"));
+            createClassFunction.setImportName("createClass");
+            createClassFunction.setImportModule("teavmJso");
+            context.module().functions.add(createClassFunction);
+        }
+        return createClassFunction;
+    }
+
+    private WasmFunction defineMethodFunction(WasmGCJsoContext context) {
+        if (defineMethodFunction == null) {
+            defineMethodFunction = new WasmFunction(context.functionTypes().of(null,
+                    WasmType.Reference.EXTERN, WasmType.Reference.EXTERN, WasmType.Reference.FUNC));
+            defineMethodFunction.setName(context.names().suggestForClass("teavm.jso@defineMethod"));
+            defineMethodFunction.setImportName("defineMethod");
+            defineMethodFunction.setImportModule("teavmJso");
+            context.module().functions.add(defineMethodFunction);
+        }
+        return defineMethodFunction;
+    }
+
+    private WasmFunction definePropertyFunction(WasmGCJsoContext context) {
+        if (definePropertyFunction == null) {
+            definePropertyFunction = new WasmFunction(context.functionTypes().of(null,
+                    WasmType.Reference.EXTERN, WasmType.Reference.EXTERN, WasmType.Reference.FUNC,
+                    WasmType.Reference.FUNC));
+            definePropertyFunction.setName(context.names().suggestForClass("teavm.jso@defineProperty"));
+            definePropertyFunction.setImportName("defineProperty");
+            definePropertyFunction.setImportModule("teavmJso");
+            context.module().functions.add(definePropertyFunction);
+        }
+        return definePropertyFunction;
+    }
+}

jso/impl/src/main/java/org/teavm/jso/impl/wasmgc/WasmGCMarshallMethodGeneratorFactory.java

@@ -0,0 +1,42 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.jso.impl.wasmgc;
+
+import org.teavm.backend.wasm.generators.gc.WasmGCCustomGenerator;
+import org.teavm.backend.wasm.generators.gc.WasmGCCustomGeneratorFactory;
+import org.teavm.backend.wasm.generators.gc.WasmGCCustomGeneratorFactoryContext;
+import org.teavm.jso.impl.JSMethods;
+import org.teavm.model.MethodReference;
+
+class WasmGCMarshallMethodGeneratorFactory implements WasmGCCustomGeneratorFactory {
+    private WasmGCJsoCommonGenerator commonGen;
+
+    WasmGCMarshallMethodGeneratorFactory(WasmGCJsoCommonGenerator commonGen) {
+        this.commonGen = commonGen;
+    }
+
+    @Override
+    public WasmGCCustomGenerator createGenerator(MethodReference methodRef,
+            WasmGCCustomGeneratorFactoryContext context) {
+        if (!methodRef.getName().equals(JSMethods.MARSHALL_TO_JS.getName())) {
+            return null;
+        }
+        var cls = context.classes().get(methodRef.getClassName());
+        return cls != null && cls.getInterfaces().contains(JSMethods.JS_MARSHALLABLE)
+                ? new WasmGCMarshallMethodGenerator(commonGen)
+                : null;
+    }
+}

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

@@ -29,7 +29,7 @@ import org.teavm.junit.TestPlatform;
 
 @RunWith(TeaVMTestRunner.class)
 @SkipJVM
-@OnlyPlatform(TestPlatform.JAVASCRIPT)
+@OnlyPlatform({TestPlatform.JAVASCRIPT, TestPlatform.WEBASSEMBLY_GC})
 @EachTestCompiledSeparately
 public class ExportClassTest {
     @Test

tools/deobfuscator-js/build.gradle.kts

@@ -65,7 +65,7 @@ val generateLibJs by tasks.register<JavaExec>("generateLibJs") {
 }
 
 val zipWithJs by tasks.register<Jar>("zipWithJs") {
-    dependsOn(generateJs, generateLibJs)
+    //dependsOn(generateJs, generateLibJs)
     archiveClassifier = "js"
     from(layout.buildDirectory.dir("teavm"), layout.buildDirectory.dir("teavm-lib"))
     entryCompression = ZipEntryCompression.DEFLATED