jso: trying to improve optimization of JSWrapper

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

@@ -553,13 +553,15 @@ class JSClassProcessor {
         newInvoke.setLocation(invoke.getLocation());
         List<Variable> newArgs = new ArrayList<>();
         if (invoke.getInstance() != null) {
-            Variable arg = marshaller.wrapArgument(callLocation, invoke.getInstance(),
+            var arg = invoke.getInstance();
-                    ValueType.object(method.getOwnerName()), false);
+            arg = marshaller.wrapArgument(callLocation, arg,
+                    ValueType.object(method.getOwnerName()), types.typeOf(arg), false);
             newArgs.add(arg);
         }
         for (int i = 0; i < invoke.getArguments().size(); ++i) {
-            Variable arg = marshaller.wrapArgument(callLocation, invoke.getArguments().get(i),
+            var arg = invoke.getArguments().get(i);
-                    method.parameterType(i), byRefParams[i]);
+            arg = marshaller.wrapArgument(callLocation, invoke.getArguments().get(i),
+                    method.parameterType(i), types.typeOf(arg), byRefParams[i]);
             newArgs.add(arg);
         }
         newInvoke.setArguments(newArgs.toArray(new Variable[0]));
@@ -597,9 +599,10 @@ class JSClassProcessor {
             if (propertyName == null) {
                 propertyName = cutPrefix(method.getName(), 3);
             }
-            Variable wrapped = marshaller.wrapArgument(callLocation, invoke.getArguments().get(0),
+            var value = invoke.getArguments().get(0);
-                    method.parameterType(0), false);
+            value = marshaller.wrapArgument(callLocation, value,
-            addPropertySet(propertyName, invoke.getInstance(), wrapped, invoke.getLocation(), pure);
+                    method.parameterType(0), types.typeOf(value), false);
+            addPropertySet(propertyName, invoke.getInstance(), value, invoke.getLocation(), pure);
             return true;
         }
         diagnostics.error(callLocation, "Method {{m0}} is not a proper native JavaScript property "
@@ -616,8 +619,9 @@ class JSClassProcessor {
     private boolean processIndexer(MethodReader method, CallLocation callLocation, InvokeInstruction invoke) {
         if (isProperGetIndexer(method.getDescriptor())) {
             Variable result = invoke.getReceiver() != null ? program.createVariable() : null;
-            addIndexerGet(invoke.getInstance(), marshaller.wrapArgument(callLocation, invoke.getArguments().get(0),
+            var index = invoke.getArguments().get(0);
-                    method.parameterType(0), false), result, invoke.getLocation());
+            addIndexerGet(invoke.getInstance(), marshaller.wrapArgument(callLocation, index,
+                    method.parameterType(0), types.typeOf(index), false), result, invoke.getLocation());
             if (result != null) {
                 result = marshaller.unwrapReturnValue(callLocation, result, method.getResultType(), false,
                         canBeOnlyJava(invoke.getReceiver()));
@@ -626,10 +630,11 @@ class JSClassProcessor {
             return true;
         }
         if (isProperSetIndexer(method.getDescriptor())) {
-            Variable index = marshaller.wrapArgument(callLocation, invoke.getArguments().get(0),
+            var index = invoke.getArguments().get(0);
-                    method.parameterType(0), false);
+            marshaller.wrapArgument(callLocation, index, method.parameterType(0), types.typeOf(index), false);
-            Variable value = marshaller.wrapArgument(callLocation, invoke.getArguments().get(1),
+            var value = invoke.getArguments().get(1);
-                    method.parameterType(1), false);
+            value = marshaller.wrapArgument(callLocation, value, method.parameterType(1),
+                    types.typeOf(value), false);
             addIndexerSet(invoke.getInstance(), index, value, invoke.getLocation());
             return true;
         }
@@ -700,8 +705,9 @@ class JSClassProcessor {
                 invoke.getLocation()));
         newInvoke.setLocation(invoke.getLocation());
         for (int i = 0; i < invoke.getArguments().size(); ++i) {
-            Variable arg = marshaller.wrapArgument(callLocation, invoke.getArguments().get(i),
+            var arg = invoke.getArguments().get(i);
-                    method.parameterType(i), byRefParams[i]);
+            arg = marshaller.wrapArgument(callLocation, arg,
+                    method.parameterType(i), types.typeOf(arg), byRefParams[i]);
             newArguments.add(arg);
         }
         newInvoke.setArguments(newArguments.toArray(new Variable[0]));
@@ -906,7 +912,8 @@ class JSClassProcessor {
         ExitInstruction exit = new ExitInstruction();
         if (insn.getReceiver() != null) {
             replacement.clear();
-            exit.setValueToReturn(marshaller.wrap(insn.getReceiver(), callee.getResultType(), null, false));
+            exit.setValueToReturn(marshaller.wrap(insn.getReceiver(), callee.getResultType(), JSType.MIXED,
+                    null, false));
             block.addAll(replacement);
         }
         block.add(exit);

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

@@ -147,7 +147,7 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
             if (method.getResultType() != ValueType.VOID) {
                 invocation.setReceiver(program.createVariable());
                 exit.setValueToReturn(marshaller.wrapArgument(callLocation, invocation.getReceiver(),
-                        method.getResultType(), false));
+                        method.getResultType(), JSType.MIXED, false));
                 basicBlock.addAll(marshallInstructions);
                 marshallInstructions.clear();
             }

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

@@ -58,7 +58,7 @@ class JSValueMarshaller {
         this.replacement = replacement;
     }
 
-    Variable wrapArgument(CallLocation location, Variable var, ValueType type, boolean byRef) {
+    Variable wrapArgument(CallLocation location, Variable var, ValueType type, JSType jsType, boolean byRef) {
         if (type instanceof ValueType.Object) {
             String className = ((ValueType.Object) type).getClassName();
             ClassReader cls = classSource.get(className);
@@ -66,7 +66,7 @@ class JSValueMarshaller {
                 return wrapFunctor(location, var, cls);
             }
         }
-        return wrap(var, type, location.getSourceLocation(), byRef);
+        return wrap(var, type, jsType, location.getSourceLocation(), byRef);
     }
 
     boolean isProperFunctor(ClassReader type) {
@@ -98,7 +98,7 @@ class JSValueMarshaller {
         return functor;
     }
 
-    Variable wrap(Variable var, ValueType type, TextLocation location, boolean byRef) {
+    Variable wrap(Variable var, ValueType type, JSType jsType, TextLocation location, boolean byRef) {
         if (byRef) {
             InvokeInstruction insn = new InvokeInstruction();
             insn.setMethod(JSMethods.ARRAY_DATA);
@@ -112,14 +112,19 @@ class JSValueMarshaller {
         if (type instanceof ValueType.Object) {
             String className = ((ValueType.Object) type).getClassName();
             if (className.equals("java.lang.Object")) {
+                if (jsType != JSType.NULL && jsType != JSType.JS) {
                     var unwrapNative = new InvokeInstruction();
                     unwrapNative.setLocation(location);
                     unwrapNative.setType(InvocationType.SPECIAL);
-                unwrapNative.setMethod(new MethodReference(JSWrapper.class, "javaToJs", Object.class, JSObject.class));
+                    unwrapNative.setMethod(new MethodReference(JSWrapper.class,
+                            "javaToJs", Object.class, JSObject.class));
                     unwrapNative.setArguments(var);
                     unwrapNative.setReceiver(program.createVariable());
                     replacement.add(unwrapNative);
                     return unwrapNative.getReceiver();
+                } else {
+                    return var;
+                }
             }
             if (!className.equals("java.lang.String")) {
                 return var;
@@ -516,7 +521,7 @@ class JSValueMarshaller {
     }
 
     Variable addStringWrap(Variable var, TextLocation location) {
-        return wrap(var, stringType, location, false);
+        return wrap(var, stringType, JSType.MIXED, location, false);
     }
 
     Variable addString(String str, TextLocation location) {

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

@@ -244,6 +244,6 @@ public final class JSWrapper {
 
     @Override
     public String toString() {
-        return JSObjects.toString(js);
+        return JSObjects.isUndefined(js) ? "undefined" : JSObjects.toString(js);
     }
 }

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

@@ -244,6 +244,53 @@ public class JSWrapperTest {
         a = processObject(JSNumber.valueOf(23));
         assertTrue(a instanceof JSString);
         assertEquals("number", ((JSString) a).stringValue());
+
+        a = processObject(processObject(new A(24)));
+        assertEquals("A(24)", a.toString());
+        assertTrue(a instanceof A);
+        assertEquals(24, ((A) a).getX());
+
+        a = processObject(identity(processObject(new A(25))));
+        assertEquals("A(25)", a.toString());
+        assertTrue(a instanceof A);
+        assertEquals(25, ((A) a).getX());
+
+        a = processObject(identity(processObject(JSString.valueOf("asd"))));
+        assertEquals("asd", a.toString());
+        assertTrue(a instanceof JSString);
+        assertEquals("asd", ((JSString) a).stringValue());
+
+        a = processObject(processObject(identity(JSString.valueOf("zxc"))));
+        assertEquals("zxc", a.toString());
+        assertTrue(a instanceof JSString);
+        assertEquals("zxc", ((JSString) a).stringValue());
+    }
+
+    @Test
+    public void exportedObject() {
+        var r = new ReturningObject() {
+            @Override
+            public Object get() {
+                var o = createEmpty();
+                setProperty(o, "foo", JSNumber.valueOf(23));
+                return o;
+            }
+        };
+        var o = extract(r);
+        var foo = getProperty(o, "foo");
+        assertTrue(foo instanceof JSNumber);
+        assertEquals(JSNumber.valueOf(23), foo);
+    }
+
+    @Test
+    public void setProperty() {
+        var o = createEmpty();
+        callSetProperty(o, JSNumber.valueOf(23));
+        assertEquals(JSNumber.valueOf(23), getProperty(o, "foo"));
+    }
+
+    private void callSetProperty(Object instance, Object o) {
+        setProperty(instance, "foo", o);
     }
 
     @JSBody(script = "return null;")
@@ -255,6 +302,22 @@ public class JSWrapperTest {
     @JSBody(params = "o", script = "return typeof o === 'number' ? 'number' : o;")
     private static native Object processObject(Object o);
 
+    private Object identity(Object o) {
+        return o;
+    }
+
+    @JSBody(params = { "o", "name" }, script = "return o[name];")
+    private static native Object getProperty(Object o, String name);
+
+    @JSBody(params = { "o", "name", "value" }, script = "o[name] = value;")
+    private static native void setProperty(Object o, String name, Object value);
+
+    @JSBody(script = "return {};")
+    private static native Object createEmpty();
+
+    @JSBody(params = "o", script = "return o.get();")
+    private static native Object extract(ReturningObject o);
+
     static class A {
         private int x;
 
@@ -271,4 +334,8 @@ public class JSWrapperTest {
             return "A(" + x + ")";
         }
     }
+
+    interface ReturningObject extends JSObject {
+        Object get();
+    }
 }