Wrap function by an object if returning value of native method is

a JSFunctor interface.

See #280

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

@@ -405,4 +405,8 @@ final class JS {
     @GeneratedBy(JSNativeGenerator.class)
     @PluggableDependency(JSNativeGenerator.class)
     public static native JSObject function(JSObject instance, JSObject property);
+
+    @GeneratedBy(JSNativeGenerator.class)
+    @PluggableDependency(JSNativeGenerator.class)
+    public static native JSObject functionAsObject(JSObject instance, JSObject property);
 }

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

@@ -66,7 +66,6 @@ import org.teavm.model.instructions.AssignInstruction;
 import org.teavm.model.instructions.ExitInstruction;
 import org.teavm.model.instructions.InvocationType;
 import org.teavm.model.instructions.InvokeInstruction;
-import org.teavm.model.instructions.StringConstantInstruction;
 import org.teavm.model.util.InstructionVariableMapper;
 import org.teavm.model.util.ModelUtils;
 import org.teavm.model.util.ProgramUtils;
@@ -114,7 +113,7 @@ class JSClassProcessor {
 
     private void getFunctorMethods(String className, Map<MethodDescriptor, MethodReference> methods) {
         classSource.getAncestors(className).forEach(cls -> {
-            if (cls.getAnnotations().get(JSFunctor.class.getName()) != null && isProperFunctor(cls)) {
+            if (cls.getAnnotations().get(JSFunctor.class.getName()) != null && marshaller.isProperFunctor(cls)) {
                 MethodReference method = cls.getMethods().iterator().next().getReference();
                 if (!methods.containsKey(method.getDescriptor())) {
                     methods.put(method.getDescriptor(), method);
@@ -241,7 +240,7 @@ class JSClassProcessor {
 
     private void setCurrentProgram(Program program) {
         this.program = program;
-        marshaller = new JSValueMarshaller(diagnostics, typeHelper, program, replacement);
+        marshaller = new JSValueMarshaller(diagnostics, typeHelper, classSource, program, replacement);
     }
 
     void processProgram(MethodHolder methodToProcess) {
@@ -333,18 +332,18 @@ class JSClassProcessor {
         newInvoke.setReceiver(result);
         newInvoke.setLocation(invoke.getLocation());
         if (invoke.getInstance() != null) {
-            Variable arg = wrapArgument(callLocation, invoke.getInstance(),
+            Variable arg = marshaller.wrapArgument(callLocation, invoke.getInstance(),
                     ValueType.object(method.getOwnerName()), false);
             newInvoke.getArguments().add(arg);
         }
         for (int i = 0; i < invoke.getArguments().size(); ++i) {
-            Variable arg = wrapArgument(callLocation, invoke.getArguments().get(i),
+            Variable arg = marshaller.wrapArgument(callLocation, invoke.getArguments().get(i),
                     method.parameterType(i), byRefParams[i]);
             newInvoke.getArguments().add(arg);
         }
         replacement.add(newInvoke);
         if (result != null) {
-            result = marshaller.unwrap(callLocation, result, method.getResultType());
+            result = marshaller.unwrapReturnValue(callLocation, result, method.getResultType());
             copyVar(result, invoke.getReceiver(), invoke.getLocation());
         }
 
@@ -365,7 +364,7 @@ class JSClassProcessor {
             Variable result = invoke.getReceiver() != null ? program.createVariable() : null;
             addPropertyGet(propertyName, invoke.getInstance(), result, invoke.getLocation());
             if (result != null) {
-                result = marshaller.unwrap(callLocation, result, method.getResultType());
+                result = marshaller.unwrapReturnValue(callLocation, result, method.getResultType());
                 copyVar(result, invoke.getReceiver(), invoke.getLocation());
             }
             return true;
@@ -375,7 +374,7 @@ class JSClassProcessor {
             if (propertyName == null) {
                 propertyName = cutPrefix(method.getName(), 3);
             }
-            Variable wrapped = wrapArgument(callLocation, invoke.getArguments().get(0),
+            Variable wrapped = marshaller.wrapArgument(callLocation, invoke.getArguments().get(0),
                     method.parameterType(0), false);
             addPropertySet(propertyName, invoke.getInstance(), wrapped, invoke.getLocation());
             return true;
@@ -394,19 +393,19 @@ 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.wrap(invoke.getArguments().get(0),
+            addIndexerGet(invoke.getInstance(), marshaller.wrapArgument(callLocation, invoke.getArguments().get(0),
-                    method.parameterType(0), invoke.getLocation(), false), result, invoke.getLocation());
+                    method.parameterType(0), false), result, invoke.getLocation());
             if (result != null) {
-                result = marshaller.unwrap(callLocation, result, method.getResultType());
+                result = marshaller.unwrapReturnValue(callLocation, result, method.getResultType());
                 copyVar(result, invoke.getReceiver(), invoke.getLocation());
             }
             return true;
         }
         if (isProperSetIndexer(method.getDescriptor())) {
-            Variable index = marshaller.wrap(invoke.getArguments().get(0), method.parameterType(0),
+            Variable index = marshaller.wrapArgument(callLocation, invoke.getArguments().get(0),
-                    invoke.getLocation(), false);
+                    method.parameterType(0), false);
-            Variable value = marshaller.wrap(invoke.getArguments().get(1), method.parameterType(1),
+            Variable value = marshaller.wrapArgument(callLocation, invoke.getArguments().get(1),
-                    invoke.getLocation(), false);
+                    method.parameterType(1), false);
             addIndexerSet(invoke.getInstance(), index, value, invoke.getLocation());
             return true;
         }
@@ -469,17 +468,17 @@ class JSClassProcessor {
         newInvoke.setType(InvocationType.SPECIAL);
         newInvoke.setReceiver(result);
         newInvoke.getArguments().add(invoke.getInstance());
-        newInvoke.getArguments().add(addStringWrap(addString(name, invoke.getLocation()),
+        newInvoke.getArguments().add(marshaller.addStringWrap(marshaller.addString(name, invoke.getLocation()),
                 invoke.getLocation()));
         newInvoke.setLocation(invoke.getLocation());
         for (int i = 0; i < invoke.getArguments().size(); ++i) {
-            Variable arg = wrapArgument(callLocation, invoke.getArguments().get(i),
+            Variable arg = marshaller.wrapArgument(callLocation, invoke.getArguments().get(i),
                     method.parameterType(i), byRefParams[i]);
             newInvoke.getArguments().add(arg);
         }
         replacement.add(newInvoke);
         if (result != null) {
-            result = marshaller.unwrap(callLocation, result, method.getResultType());
+            result = marshaller.unwrapReturnValue(callLocation, result, method.getResultType());
             copyVar(result, invoke.getReceiver(), invoke.getLocation());
         }
 
@@ -627,11 +626,11 @@ class JSClassProcessor {
         insn.setMethod(calleeRef);
         replacement.clear();
         if (!callee.hasModifier(ElementModifier.STATIC)) {
-            insn.setInstance(marshaller.unwrap(location, program.variableAt(paramIndex++),
+            insn.setInstance(marshaller.unwrapReturnValue(location, program.variableAt(paramIndex++),
                     ValueType.object(calleeRef.getClassName())));
         }
         for (int i = 0; i < callee.parameterCount(); ++i) {
-            insn.getArguments().add(marshaller.unwrap(location, program.variableAt(paramIndex++),
+            insn.getArguments().add(marshaller.unwrapReturnValue(location, program.variableAt(paramIndex++),
                     callee.parameterType(i)));
         }
         if (callee.getResultType() != ValueType.VOID) {
@@ -655,7 +654,7 @@ class JSClassProcessor {
 
     private void addPropertyGet(String propertyName, Variable instance, Variable receiver,
             TextLocation location) {
-        Variable nameVar = addStringWrap(addString(propertyName, location), location);
+        Variable nameVar = marshaller.addStringWrap(marshaller.addString(propertyName, location), location);
         InvokeInstruction insn = new InvokeInstruction();
         insn.setType(InvocationType.SPECIAL);
         insn.setMethod(new MethodReference(JS.class, "get", JSObject.class, JSObject.class, JSObject.class));
@@ -667,7 +666,7 @@ class JSClassProcessor {
     }
 
     private void addPropertySet(String propertyName, Variable instance, Variable value, TextLocation location) {
-        Variable nameVar = addStringWrap(addString(propertyName, location), location);
+        Variable nameVar = marshaller.addStringWrap(marshaller.addString(propertyName, location), location);
         InvokeInstruction insn = new InvokeInstruction();
         insn.setType(InvocationType.SPECIAL);
         insn.setMethod(new MethodReference(JS.class, "set", JSObject.class, JSObject.class,
@@ -710,61 +709,6 @@ class JSClassProcessor {
         replacement.add(insn);
     }
 
-    private Variable addStringWrap(Variable var, TextLocation location) {
-        return marshaller.wrap(var, ValueType.object("java.lang.String"), location, false);
-    }
-
-    private Variable addString(String str, TextLocation location) {
-        Variable var = program.createVariable();
-        StringConstantInstruction nameInsn = new StringConstantInstruction();
-        nameInsn.setReceiver(var);
-        nameInsn.setConstant(str);
-        nameInsn.setLocation(location);
-        replacement.add(nameInsn);
-        return var;
-    }
-
-    private Variable wrapArgument(CallLocation location, Variable var, ValueType type, boolean byRef) {
-        if (type instanceof ValueType.Object) {
-            String className = ((ValueType.Object) type).getClassName();
-            ClassReader cls = classSource.get(className);
-            if (cls.getAnnotations().get(JSFunctor.class.getName()) != null) {
-                return wrapFunctor(location, var, cls);
-            }
-        }
-        return marshaller.wrap(var, type, location.getSourceLocation(), byRef);
-    }
-
-    private boolean isProperFunctor(ClassReader type) {
-        if (!type.hasModifier(ElementModifier.INTERFACE)) {
-            return false;
-        }
-        return type.getMethods().stream()
-                .filter(method -> method.hasModifier(ElementModifier.ABSTRACT))
-                .count() == 1;
-    }
-
-    private Variable wrapFunctor(CallLocation location, Variable var, ClassReader type) {
-        if (!isProperFunctor(type)) {
-            diagnostics.error(location, "Wrong functor: {{c0}}", type.getName());
-            return var;
-        }
-        String name = type.getMethods().stream()
-                .filter(method -> method.hasModifier(ElementModifier.ABSTRACT))
-                .findFirst().get().getName();
-        Variable functor = program.createVariable();
-        Variable nameVar = addStringWrap(addString(name, location.getSourceLocation()), location.getSourceLocation());
-        InvokeInstruction insn = new InvokeInstruction();
-        insn.setType(InvocationType.SPECIAL);
-        insn.setMethod(new MethodReference(JS.class, "function", JSObject.class, JSObject.class, JSObject.class));
-        insn.setReceiver(functor);
-        insn.getArguments().add(var);
-        insn.getArguments().add(nameVar);
-        insn.setLocation(location.getSourceLocation());
-        replacement.add(insn);
-        return functor;
-    }
-
     private MethodReader getMethod(MethodReference ref) {
         ClassReader cls = classSource.get(ref.getClassName());
         if (cls == null) {

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

@@ -44,6 +44,9 @@ public class JSNativeGenerator implements Injector, DependencyPlugin, Generator
             case "function":
                 writeFunction(context, writer);
                 break;
+            case "functionAsObject":
+                writeFunctionAsObject(context, writer);
+                break;
         }
     }
 
@@ -69,6 +72,16 @@ public class JSNativeGenerator implements Injector, DependencyPlugin, Generator
         writer.append("return ").append(thisName).append("[name]();").softNewLine();
     }
 
+    private void writeFunctionAsObject(GeneratorContext context, SourceWriter writer) throws IOException {
+        String thisName = context.getParameterName(1);
+        String methodName = context.getParameterName(2);
+
+        writer.append("var result").ws().append("=").ws().append("{};").softNewLine();
+        writer.append("result[").append(methodName).append("]").ws().append("=").ws().append(thisName)
+                .append(";").softNewLine();
+        writer.append("return result;").softNewLine();
+    }
+
     @Override
     public void generate(InjectorContext context, MethodReference methodRef) throws IOException {
         SourceWriter writer = context.getWriter();
@@ -143,9 +156,6 @@ public class JSNativeGenerator implements Injector, DependencyPlugin, Generator
                     context.writeExpr(context.getArgument(0), context.getPrecedence());
                 }
                 break;
-            case "function":
-                generateFunction(context);
-                break;
             case "unwrapString":
                 writer.append("$rt_str(");
                 context.writeExpr(context.getArgument(0), Precedence.min());
@@ -200,17 +210,6 @@ public class JSNativeGenerator implements Injector, DependencyPlugin, Generator
         }
     }
 
-    private void generateFunction(InjectorContext context) throws IOException {
-        SourceWriter writer = context.getWriter();
-        writer.append("(function($instance,").ws().append("$property)").ws().append("{").ws()
-                .append("return function()").ws().append("{").indent().softNewLine();
-        writer.append("return $instance[$property].apply($instance,").ws().append("arguments);").softNewLine();
-        writer.outdent().append("};})(");
-        context.writeExpr(context.getArgument(0));
-        writer.append(",").ws();
-        context.writeExpr(context.getArgument(1));
-        writer.append(")");
-    }
 
     private void renderProperty(Expr property, InjectorContext context) throws IOException {
         SourceWriter writer = context.getWriter();

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

@@ -120,7 +120,7 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
 
             BasicBlock basicBlock = program.createBasicBlock();
             List<Instruction> marshallInstructions = new ArrayList<>();
-            JSValueMarshaller marshaller = new JSValueMarshaller(diagnostics, typeHelper, program,
+            JSValueMarshaller marshaller = new JSValueMarshaller(diagnostics, typeHelper, innerSource, program,
                     marshallInstructions);
 
             List<Variable> variablesToPass = new ArrayList<>();
@@ -129,7 +129,8 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
             }
 
             for (int i = 0; i < method.parameterCount(); ++i) {
-                Variable var = marshaller.unwrap(callLocation, variablesToPass.get(i), method.parameterType(i));
+                Variable var = marshaller.unwrapReturnValue(callLocation, variablesToPass.get(i),
+                        method.parameterType(i));
                 variablesToPass.set(i, var);
             }
 
@@ -146,8 +147,8 @@ class JSObjectClassTransformer implements ClassHolderTransformer {
             ExitInstruction exit = new ExitInstruction();
             if (method.getResultType() != ValueType.VOID) {
                 invocation.setReceiver(program.createVariable());
-                exit.setValueToReturn(marshaller.wrap(invocation.getReceiver(), method.getResultType(),
+                exit.setValueToReturn(marshaller.wrapArgument(callLocation, invocation.getReceiver(),
-                        null, false));
+                        method.getResultType(), false));
                 basicBlock.addAll(marshallInstructions);
                 marshallInstructions.clear();
             }

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

@@ -18,10 +18,14 @@ package org.teavm.jso.impl;
 import java.util.List;
 import java.util.function.Function;
 import org.teavm.diagnostics.Diagnostics;
+import org.teavm.jso.JSFunctor;
 import org.teavm.jso.JSObject;
 import org.teavm.jso.core.JSArray;
 import org.teavm.jso.core.JSArrayReader;
 import org.teavm.model.CallLocation;
+import org.teavm.model.ClassReader;
+import org.teavm.model.ClassReaderSource;
+import org.teavm.model.ElementModifier;
 import org.teavm.model.Instruction;
 import org.teavm.model.MethodReference;
 import org.teavm.model.Program;
@@ -32,22 +36,66 @@ import org.teavm.model.instructions.CastInstruction;
 import org.teavm.model.instructions.ClassConstantInstruction;
 import org.teavm.model.instructions.InvocationType;
 import org.teavm.model.instructions.InvokeInstruction;
+import org.teavm.model.instructions.StringConstantInstruction;
 
 class JSValueMarshaller {
     private Diagnostics diagnostics;
     private JSTypeHelper typeHelper;
+    private ClassReaderSource classSource;
     private Program program;
     private List<Instruction> replacement;
 
-    JSValueMarshaller(Diagnostics diagnostics, JSTypeHelper typeHelper, Program program,
+    JSValueMarshaller(Diagnostics diagnostics, JSTypeHelper typeHelper, ClassReaderSource classSource,
-            List<Instruction> replacement) {
+            Program program, List<Instruction> replacement) {
         this.diagnostics = diagnostics;
         this.typeHelper = typeHelper;
+        this.classSource = classSource;
         this.program = program;
         this.replacement = replacement;
     }
 
-    public Variable wrap(Variable var, ValueType type, TextLocation location, boolean byRef) {
+    Variable wrapArgument(CallLocation location, Variable var, ValueType type, boolean byRef) {
+        if (type instanceof ValueType.Object) {
+            String className = ((ValueType.Object) type).getClassName();
+            ClassReader cls = classSource.get(className);
+            if (cls.getAnnotations().get(JSFunctor.class.getName()) != null) {
+                return wrapFunctor(location, var, cls);
+            }
+        }
+        return wrap(var, type, location.getSourceLocation(), byRef);
+    }
+
+    boolean isProperFunctor(ClassReader type) {
+        if (!type.hasModifier(ElementModifier.INTERFACE)) {
+            return false;
+        }
+        return type.getMethods().stream()
+                .filter(method -> method.hasModifier(ElementModifier.ABSTRACT))
+                .count() == 1;
+    }
+
+    private Variable wrapFunctor(CallLocation location, Variable var, ClassReader type) {
+        if (!isProperFunctor(type)) {
+            diagnostics.error(location, "Wrong functor: {{c0}}", type.getName());
+            return var;
+        }
+        String name = type.getMethods().stream()
+                .filter(method -> method.hasModifier(ElementModifier.ABSTRACT))
+                .findFirst().get().getName();
+        Variable functor = program.createVariable();
+        Variable nameVar = addStringWrap(addString(name, location.getSourceLocation()), location.getSourceLocation());
+        InvokeInstruction insn = new InvokeInstruction();
+        insn.setType(InvocationType.SPECIAL);
+        insn.setMethod(new MethodReference(JS.class, "function", JSObject.class, JSObject.class, JSObject.class));
+        insn.setReceiver(functor);
+        insn.getArguments().add(var);
+        insn.getArguments().add(nameVar);
+        insn.setLocation(location.getSourceLocation());
+        replacement.add(insn);
+        return functor;
+    }
+
+    Variable wrap(Variable var, ValueType type, TextLocation location, boolean byRef) {
         if (byRef) {
             InvokeInstruction insn = new InvokeInstruction();
             insn.setMethod(new MethodReference(JS.class, "arrayData", Object.class, JSObject.class));
@@ -169,6 +217,17 @@ class JSValueMarshaller {
         return new MethodReference(JS.class, "arrayWrapper", Function.class);
     }
 
+    Variable unwrapReturnValue(CallLocation location, Variable var, ValueType type) {
+        if (type instanceof ValueType.Object) {
+            String className = ((ValueType.Object) type).getClassName();
+            ClassReader cls = classSource.get(className);
+            if (cls.getAnnotations().get(JSFunctor.class.getName()) != null) {
+                return unwrapFunctor(location, var, cls);
+            }
+        }
+        return unwrap(location, var, type);
+    }
+
     Variable unwrap(CallLocation location, Variable var, ValueType type) {
         if (type instanceof ValueType.Primitive) {
             switch (((ValueType.Primitive) type).getKind()) {
@@ -402,4 +461,40 @@ class JSValueMarshaller {
         replacement.add(insn);
         return result;
     }
+
+    private Variable unwrapFunctor(CallLocation location, Variable var, ClassReader type) {
+        if (!isProperFunctor(type)) {
+            diagnostics.error(location, "Wrong functor: {{c0}}", type.getName());
+            return var;
+        }
+        String name = type.getMethods().stream()
+                .filter(method -> method.hasModifier(ElementModifier.ABSTRACT))
+                .findFirst().get().getName();
+        Variable functor = program.createVariable();
+        Variable nameVar = addStringWrap(addString(name, location.getSourceLocation()), location.getSourceLocation());
+        InvokeInstruction insn = new InvokeInstruction();
+        insn.setType(InvocationType.SPECIAL);
+        insn.setMethod(new MethodReference(JS.class, "functionAsObject", JSObject.class, JSObject.class,
+                JSObject.class));
+        insn.setReceiver(functor);
+        insn.getArguments().add(var);
+        insn.getArguments().add(nameVar);
+        insn.setLocation(location.getSourceLocation());
+        replacement.add(insn);
+        return functor;
+    }
+
+    Variable addStringWrap(Variable var, TextLocation location) {
+        return wrap(var, ValueType.object("java.lang.String"), location, false);
+    }
+
+    Variable addString(String str, TextLocation location) {
+        Variable var = program.createVariable();
+        StringConstantInstruction nameInsn = new StringConstantInstruction();
+        nameInsn.setReceiver(var);
+        nameInsn.setConstant(str);
+        nameInsn.setLocation(location);
+        replacement.add(nameInsn);
+        return var;
+    }
 }

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

@@ -15,7 +15,8 @@
  */
 package org.teavm.jso.test;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertSame;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.teavm.jso.JSBody;
@@ -33,6 +34,11 @@ public class FunctorTest {
         assertEquals("(5)", testMethod((a, b) -> a + b, 2, 3));
     }
 
+    @Test
+    public void functorParamsMarshaled() {
+        assertEquals("(q,w)", testMethod((a, b) -> a + "," + b, "q", "w"));
+    }
+
     @Test
     public void functorIdentityPreserved() {
         JSBiFunction javaFunction = (a, b) -> a + b;
@@ -65,9 +71,36 @@ public class FunctorTest {
         assertEquals("baz_ok", wp.propbaz());
     }
 
+    @Test
+    public void functorPassedBack() {
+        JSBiFunction function = getBiFunction();
+        assertEquals(23042, function.foo(23, 42));
+    }
+
+    @Test
+    public void functorParamsMarshaledBack() {
+        JSStringBiFunction function = getStringBiFunction();
+        assertEquals("q,w", function.foo("q", "w"));
+    }
+
     @JSBody(params = { "f", "a", "b" }, script = "return '(' + f(a, b) + ')';")
     private static native String testMethod(JSBiFunction f, int a, int b);
 
+    @JSBody(params = { "f", "a", "b" }, script = "return '(' + f(a, b) + ')';")
+    private static native String testMethod(JSStringBiFunction f, String a, String b);
+
+    @JSBody(script = ""
+            + "return function(a, b) {"
+                + "return a * 1000 + b;"
+            + "};")
+    private static native JSBiFunction getBiFunction();
+
+    @JSBody(script = ""
+            + "return function(a, b) {"
+            + "return a + ',' + b;"
+            + "};")
+    private static native JSStringBiFunction getStringBiFunction();
+
     @JSBody(params = "f", script = "return f;")
     private static native JSObject getFunction(JSBiFunction f);
 
@@ -79,6 +112,11 @@ public class FunctorTest {
         int foo(int a, int b);
     }
 
+    @JSFunctor
+    interface JSStringBiFunction extends JSObject {
+        String foo(String a, String b);
+    }
+
     @JSFunctor
     interface JSFunctionWithDefaultMethod extends JSObject {
         int foo(int a);