JS: Support JSByRef annotation on method return types

jso/core/src/main/java/org/teavm/jso/JSByRef.java

@@ -26,6 +26,6 @@ import java.lang.annotation.Target;
  * to: byte[], short[], char[], int[], float[], double[] or T[], where T is JSObject.</p>
  */
 @Retention(RetentionPolicy.RUNTIME)
-@Target(ElementType.PARAMETER)
+@Target({ ElementType.PARAMETER, ElementType.METHOD })
 public @interface JSByRef {
 }

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

@@ -35,6 +35,34 @@ final class JS {
     @InjectedBy(JSNativeGenerator.class)
     public static native JSObject arrayData(Object array);
 
+    @InjectedBy(JSNativeGenerator.class)
+    @PluggableDependency(JSNativeGenerator.class)
+    public static native byte[] dataToByteArray(JSObject obj);
+
+    @InjectedBy(JSNativeGenerator.class)
+    @PluggableDependency(JSNativeGenerator.class)
+    public static native char[] dataToCharArray(JSObject obj);
+
+    @InjectedBy(JSNativeGenerator.class)
+    @PluggableDependency(JSNativeGenerator.class)
+    public static native short[] dataToShortArray(JSObject obj);
+
+    @InjectedBy(JSNativeGenerator.class)
+    @PluggableDependency(JSNativeGenerator.class)
+    public static native int[] dataToIntArray(JSObject obj);
+
+    @InjectedBy(JSNativeGenerator.class)
+    @PluggableDependency(JSNativeGenerator.class)
+    public static native float[] dataToFloatArray(JSObject obj);
+
+    @InjectedBy(JSNativeGenerator.class)
+    @PluggableDependency(JSNativeGenerator.class)
+    public static native double[] dataToDoubleArray(JSObject obj);
+
+    @InjectedBy(JSNativeGenerator.class)
+    @PluggableDependency(JSNativeGenerator.class)
+    public static native JSObject[] dataToArray(JSObject obj);
+
     @InjectedBy(JSNativeGenerator.class)
     public static native JSObject wrap(byte value);
 

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

@@ -361,6 +361,13 @@ class JSClassProcessor {
             }
         }
 
+        boolean returnByRef = method.getAnnotations().get(JSByRef.class.getName()) != null;
+        if (returnByRef && !typeHelper.isSupportedByRefType(method.getResultType())) {
+            diagnostics.error(callLocation, "Method {{m0}} is marked with @JSByRef, but does not return valid "
+                    + "array type");
+            return false;
+        }
+
         requireJSBody(diagnostics, method);
         MethodReference delegate = repository.methodMap.get(method.getReference());
         if (delegate == null) {
@@ -387,7 +394,7 @@ class JSClassProcessor {
         newInvoke.setArguments(newArgs.toArray(new Variable[0]));
         replacement.add(newInvoke);
         if (result != null) {
-            result = marshaller.unwrapReturnValue(callLocation, result, method.getResultType());
+            result = marshaller.unwrapReturnValue(callLocation, result, method.getResultType(), returnByRef);
             copyVar(result, invoke.getReceiver(), invoke.getLocation());
         }
 
@@ -406,7 +413,7 @@ class JSClassProcessor {
             Variable result = invoke.getReceiver() != null ? program.createVariable() : null;
             addPropertyGet(propertyName, invoke.getInstance(), result, invoke.getLocation());
             if (result != null) {
-                result = marshaller.unwrapReturnValue(callLocation, result, method.getResultType());
+                result = marshaller.unwrapReturnValue(callLocation, result, method.getResultType(), false);
                 copyVar(result, invoke.getReceiver(), invoke.getLocation());
             }
             return true;
@@ -438,7 +445,7 @@ class JSClassProcessor {
             addIndexerGet(invoke.getInstance(), marshaller.wrapArgument(callLocation, invoke.getArguments().get(0),
                     method.parameterType(0), false), result, invoke.getLocation());
             if (result != null) {
-                result = marshaller.unwrapReturnValue(callLocation, result, method.getResultType());
+                result = marshaller.unwrapReturnValue(callLocation, result, method.getResultType(), false);
                 copyVar(result, invoke.getReceiver(), invoke.getLocation());
             }
             return true;
@@ -520,7 +527,7 @@ class JSClassProcessor {
         newInvoke.setArguments(newArguments.toArray(new Variable[0]));
         replacement.add(newInvoke);
         if (result != null) {
-            result = marshaller.unwrapReturnValue(callLocation, result, method.getResultType());
+            result = marshaller.unwrapReturnValue(callLocation, result, method.getResultType(), false);
             copyVar(result, invoke.getReceiver(), invoke.getLocation());
         }
 
@@ -681,12 +688,12 @@ class JSClassProcessor {
         replacement.clear();
         if (!callee.hasModifier(ElementModifier.STATIC)) {
             insn.setInstance(marshaller.unwrapReturnValue(location, program.variableAt(paramIndex++),
-                    ValueType.object(calleeRef.getClassName())));
+                    ValueType.object(calleeRef.getClassName()), false));
         }
         Variable[] args = new Variable[callee.parameterCount()];
         for (int i = 0; i < callee.parameterCount(); ++i) {
             args[i] = marshaller.unwrapReturnValue(location, program.variableAt(paramIndex++),
-                    callee.parameterType(i));
+                    callee.parameterType(i), false);
         }
         insn.setArguments(args);
         if (callee.getResultType() != ValueType.VOID) {

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

@@ -23,7 +23,7 @@ import org.teavm.jso.core.JSArrayReader;
 import org.teavm.model.MethodReference;
 import org.teavm.model.ValueType;
 
-public final class JSMethods {
+final class JSMethods {
     public static final MethodReference GET = new MethodReference(JS.class, "get", JSObject.class,
             JSObject.class, JSObject.class);
     public static final MethodReference SET = new MethodReference(JS.class, "set", JSObject.class, JSObject.class,
@@ -93,6 +93,21 @@ public final class JSMethods {
     public static final MethodReference ARRAY_UNWRAPPER = new MethodReference(JS.class,
             "arrayUnwrapper", Class.class, Function.class);
 
+    public static final MethodReference DATA_TO_BYTE_ARRAY = new MethodReference(JS.class,
+            "dataToByteArray", JSObject.class, byte[].class);
+    public static final MethodReference DATA_TO_SHORT_ARRAY = new MethodReference(JS.class,
+            "dataToShortArray", JSObject.class, short[].class);
+    public static final MethodReference DATA_TO_CHAR_ARRAY = new MethodReference(JS.class,
+            "dataToCharArray", JSObject.class, char[].class);
+    public static final MethodReference DATA_TO_INT_ARRAY = new MethodReference(JS.class,
+            "dataToIntArray", JSObject.class, int[].class);
+    public static final MethodReference DATA_TO_FLOAT_ARRAY = new MethodReference(JS.class,
+            "dataToFloatArray", JSObject.class, float[].class);
+    public static final MethodReference DATA_TO_DOUBLE_ARRAY = new MethodReference(JS.class,
+            "dataToDoubleArray", JSObject.class, double[].class);
+    public static final MethodReference DATA_TO_ARRAY = new MethodReference(JS.class,
+            "dataToArray", JSObject.class, JSObject[].class);
+
     public static final MethodReference FUNCTION_AS_OBJECT = new MethodReference(JS.class, "functionAsObject",
             JSObject.class, JSObject.class, JSObject.class);
 

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

@@ -178,6 +178,43 @@ public class JSNativeGenerator implements Injector, DependencyPlugin, Generator
                     writer.append(")");
                 }
                 break;
+
+            case "dataToByteArray":
+                writer.append("$rt_wrapArray($rt_bytecls(),").ws();
+                context.writeExpr(context.getArgument(0), Precedence.min());
+                writer.append(")");
+                break;
+            case "dataToShortArray":
+                writer.append("$rt_wrapArray($rt_shortcls(),").ws();
+                context.writeExpr(context.getArgument(0), Precedence.min());
+                writer.append(")");
+                break;
+            case "dataToCharArray":
+                writer.append("$rt_wrapArray($rt_charcls(),").ws();
+                context.writeExpr(context.getArgument(0), Precedence.min());
+                writer.append(")");
+                break;
+            case "dataToIntArray":
+                writer.append("$rt_wrapArray($rt_intcls(),").ws();
+                context.writeExpr(context.getArgument(0), Precedence.min());
+                writer.append(")");
+                break;
+            case "dataToFloatArray":
+                writer.append("$rt_wrapArray($rt_floatcls(),").ws();
+                context.writeExpr(context.getArgument(0), Precedence.min());
+                writer.append(")");
+                break;
+            case "dataToDoubleArray":
+                writer.append("$rt_wrapArray($rt_doublecls(),").ws();
+                context.writeExpr(context.getArgument(0), Precedence.min());
+                writer.append(")");
+                break;
+            case "dataToArray":
+                writer.append("$rt_wrapArray($rt_objcls(),").ws();
+                context.writeExpr(context.getArgument(0), Precedence.min());
+                writer.append(")");
+                break;
+
             default:
                 if (methodRef.getName().startsWith("unwrap")) {
                     context.writeExpr(context.getArgument(0), context.getPrecedence());
@@ -209,6 +246,28 @@ public class JSNativeGenerator implements Injector, DependencyPlugin, Generator
             case "unwrapString":
                 method.getResult().propagate(agent.getType("java.lang.String"));
                 break;
+
+            case "dataToByteArray":
+                method.getResult().propagate(agent.getType("[B"));
+                break;
+            case "dataToShortArray":
+                method.getResult().propagate(agent.getType("[S"));
+                break;
+            case "dataToCharArray":
+                method.getResult().propagate(agent.getType("[C"));
+                break;
+            case "dataToIntArray":
+                method.getResult().propagate(agent.getType("[I"));
+                break;
+            case "dataToFloatArray":
+                method.getResult().propagate(agent.getType("[F"));
+                break;
+            case "dataToDoubleArray":
+                method.getResult().propagate(agent.getType("[D"));
+                break;
+            case "dataToArray":
+                method.getResult().propagate(agent.getType("[Ljava/lang/Object;"));
+                break;
         }
     }
 

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

@@ -132,7 +132,7 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
 
             for (int i = 0; i < method.parameterCount(); ++i) {
                 variablesToPass[i] = marshaller.unwrapReturnValue(callLocation, variablesToPass[i],
-                        method.parameterType(i));
+                        method.parameterType(i), false);
             }
 
             basicBlock.addAll(marshallInstructions);

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

@@ -218,7 +218,11 @@ class JSValueMarshaller {
         return JSMethods.ARRAY_WRAPPER;
     }
 
-    Variable unwrapReturnValue(CallLocation location, Variable var, ValueType type) {
+    Variable unwrapReturnValue(CallLocation location, Variable var, ValueType type, boolean byRef) {
+        if (byRef) {
+            return unwrapByRef(location, var, type);
+        }
+
         if (type instanceof ValueType.Object) {
             String className = ((ValueType.Object) type).getClassName();
             ClassReader cls = classSource.get(className);
@@ -229,6 +233,29 @@ class JSValueMarshaller {
         return unwrap(location, var, type);
     }
 
+    private Variable unwrapByRef(CallLocation location, Variable var, ValueType type) {
+        type = ((ValueType.Array) type).getItemType();
+        if (type instanceof ValueType.Primitive) {
+            switch (((ValueType.Primitive) type).getKind()) {
+                case BYTE:
+                    return invokeMethod(location, JSMethods.DATA_TO_BYTE_ARRAY, var);
+                case SHORT:
+                    return invokeMethod(location, JSMethods.DATA_TO_SHORT_ARRAY, var);
+                case CHARACTER:
+                    return invokeMethod(location, JSMethods.DATA_TO_CHAR_ARRAY, var);
+                case INTEGER:
+                    return invokeMethod(location, JSMethods.DATA_TO_INT_ARRAY, var);
+                case FLOAT:
+                    return invokeMethod(location, JSMethods.DATA_TO_FLOAT_ARRAY, var);
+                case DOUBLE:
+                    return invokeMethod(location, JSMethods.DATA_TO_DOUBLE_ARRAY, var);
+                default:
+                    break;
+            }
+        }
+        return invokeMethod(location, JSMethods.DATA_TO_ARRAY, var);
+    }
+
     Variable unwrap(CallLocation location, Variable var, ValueType type) {
         if (type instanceof ValueType.Primitive) {
             switch (((ValueType.Primitive) type).getKind()) {
@@ -302,6 +329,18 @@ class JSValueMarshaller {
         return var;
     }
 
+    private Variable invokeMethod(CallLocation location, MethodReference method, Variable var) {
+        InvokeInstruction invoke = new InvokeInstruction();
+        invoke.setArguments(var);
+        invoke.setMethod(method);
+        invoke.setReceiver(program.createVariable());
+        invoke.setType(InvocationType.SPECIAL);
+        invoke.setLocation(location.getSourceLocation());
+        replacement.add(invoke);
+
+        return invoke.getReceiver();
+    }
+
     private Variable unwrapSingleDimensionArray(CallLocation location, Variable var, ValueType type) {
         Variable result = program.createVariable();
 

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

@@ -17,6 +17,7 @@ package org.teavm.jso.test;
 
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertTrue;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -158,6 +159,15 @@ public class ConversionTest {
         assertEquals(44, array[1]);
     }
 
+    @Test
+    public void returnsArrayByRef() {
+        int[] first = { 23, 42 };
+        int[] second = rewrap(first);
+        assertNotSame(first, second);
+        second[0] = 99;
+        assertEquals(99, first[0]);
+    }
+
     @JSBody(params = { "a", "b", "c", "d", "e", "f", "g", "h" }, script = ""
             + "return '' + a + ':' + b + ':' + c + ':' + d + ':' + e + ':' + f.toFixed(1) + ':'"
                     + "+ g.toFixed(1) + ':' + h;")
@@ -336,4 +346,8 @@ public class ConversionTest {
                 + "}"
             + "};")
     private static native ByRefMutator createByRefMutator();
+
+    @JSByRef
+    @JSBody(params = "array", script = "return array;")
+    private static native int[] rewrap(@JSByRef int[] array);
 }