Disallow @Objects-annotated classes to have fields or constructors

compiler/src/main/java/motif/compiler/Processor.kt

@@ -32,6 +32,7 @@ class Processor : AbstractProcessor() {
 
     // For testing only.
     var validationErrors: GraphValidationErrors? = null
+    var parsingError: ParsingError? = null
 
     private val hasErrors: Boolean
         get() = !(validationErrors?.isEmpty() ?: true)
@@ -56,6 +57,7 @@ class Processor : AbstractProcessor() {
         val sourceSet = try {
             SourceSetFactory(processingEnv).create(roundEnv)
         } catch (e: ParsingError) {
+            this.parsingError = e
             processingEnv.messager.printMessage(Diagnostic.Kind.ERROR, "\n${e.message}\n${e.element}\n", e.element)
             return
         }

compiler/src/main/java/motif/compiler/ir/ObjectsImplFactory.kt → compiler/src/main/java/motif/compiler/ir/ObjectsClassFactory.kt

@@ -36,10 +36,17 @@ import javax.lang.model.element.Element
 import javax.lang.model.element.Modifier
 import javax.lang.model.type.DeclaredType
 
-class ObjectsImplFactory(override val env: ProcessingEnvironment) : JavaxUtil {
+class ObjectsClassFactory(override val env: ProcessingEnvironment) : JavaxUtil {
 
     fun create(scopeType: DeclaredType): ObjectsClass? {
         val objectsType = scopeType.annotatedInnerType(Objects::class) ?: return null
+        if (objectsType.hasFieldsRecursive()) {
+            throw ParsingError(objectsType.asElement(), "@Objects-annotated class may not declare any fields.")
+        }
+        if (objectsType.hasNonDefaultConstructor()) {
+            throw ParsingError(objectsType.asElement(), "@Objects-annotated class may not declare any non-default constructors.")
+        }
+
         val methods = objectsType.methods()
                 .onEach {
                     if (it.isVoid) throw ParsingError(it.element, "Factory method must not return void")

compiler/src/main/java/motif/compiler/ir/ScopeClassFactory.kt

@@ -28,7 +28,7 @@ class ScopeClassFactory(override val env: ProcessingEnvironment) : JavaxUtil {
 
     private val childFactory = ChildDeclarationFactory(env)
     private val accessMethodFactory = AccessMethodFactory(env)
-    private val objectsClassFactory = ObjectsImplFactory(env)
+    private val objectsClassFactory = ObjectsClassFactory(env)
     private val explicitDependenciesFactory = ExplicitDependenciesFactory(env)
 
     fun create(scopeType: DeclaredType): ScopeClass {

compiler/src/main/java/motif/compiler/javax/JavaxUtil.kt

@@ -25,6 +25,7 @@ import javax.lang.model.element.ExecutableElement
 import javax.lang.model.element.TypeElement
 import javax.lang.model.type.DeclaredType
 import javax.lang.model.type.ExecutableType
+import javax.lang.model.type.TypeKind
 import javax.lang.model.type.TypeMirror
 import javax.lang.model.util.ElementFilter
 import kotlin.reflect.KClass
@@ -73,6 +74,31 @@ interface JavaxUtil {
         return ElementFilter.constructorsIn(asElement().enclosedElements)
     }
 
+    fun DeclaredType.hasFieldsRecursive(): Boolean {
+        val typeElement: TypeElement = asElement() as TypeElement
+        if (ElementFilter.fieldsIn(typeElement.enclosedElements).isNotEmpty()) {
+            return true
+        }
+
+        val superclass: TypeMirror = typeElement.superclass
+        if (superclass.kind == TypeKind.DECLARED) {
+            if ((superclass as DeclaredType).hasFieldsRecursive()) {
+                return true
+            }
+        } else if (superclass.kind != TypeKind.NONE) {
+            // TODO Is it possible for TypeElement.superclass to return a TypeMirror of TypeKind other than
+            // DECLARED or NONE? If so, then we should not throw an Exception here and instead handle the
+            // recursion properly.
+            throw IllegalStateException("Unknown superclass type.")
+        }
+
+        return false
+    }
+
+    fun DeclaredType.hasNonDefaultConstructor(): Boolean {
+        return constructors().find { !it.parameters.isEmpty() } != null
+    }
+
     fun DeclaredType.packageName(): String {
         return MoreElements.getPackage(asElement()).qualifiedName.toString()
     }

compiler/src/test/java/motif/compiler/TestHarness.java

@@ -18,6 +18,7 @@
 import com.google.common.truth.Truth;
 import com.google.testing.compile.Compilation;
 import com.google.testing.compile.MotifTestCompiler;
+import motif.compiler.errors.parsing.ParsingError;
 import motif.ir.graph.errors.GraphValidationErrors;
 import motif.stubcompiler.StubProcessor;
 import org.junit.Ignore;
@@ -132,8 +133,16 @@ public void test() throws Throwable {
             GraphValidationErrors errors = processor.getValidationErrors();
             Truth.assertThat(errors).isNotNull();
             expectedException.set(null, errors);
-        } catch (NoSuchFieldException ignore) {
-            assertThat(compilation).succeeded();
+        } catch (NoSuchFieldException e) {
+            try {
+                Field expectedException = testClass.getField("parsingError");
+                assertThat(compilation).failed();
+                ParsingError error = processor.getParsingError();
+                Truth.assertThat(error).isNotNull();
+                expectedException.set(null, error);
+            } catch (NoSuchFieldException ee) {
+                assertThat(compilation).succeeded();
+            }
         }
 
         try {

it/src/main/java/testcases/E019_objects_fields/Scope.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2018 Uber Technologies, Inc.
+ *
+ * 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 testcases.E019_objects_fields;
+
+@motif.Scope
+public interface Scope {
+
+    @motif.Objects
+    class Objects {
+
+        private final String s = "s";
+    }
+}

it/src/main/java/testcases/E019_objects_fields/Test.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2018 Uber Technologies, Inc.
+ *
+ * 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 testcases.E019_objects_fields;
+
+import motif.compiler.errors.parsing.ParsingError;
+
+import static com.google.common.truth.Truth.assertThat;
+
+public class Test {
+
+    public static ParsingError parsingError;
+
+    public static void run() {
+        assertThat(parsingError).isNotNull();
+    }
+}

it/src/main/java/testcases/E020_objects_constructor/Scope.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2018 Uber Technologies, Inc.
+ *
+ * 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 testcases.E020_objects_constructor;
+
+@motif.Scope
+public interface Scope {
+
+    @motif.Objects
+    class Objects {
+
+        Objects(String s) {}
+    }
+}

it/src/main/java/testcases/E020_objects_constructor/Test.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2018 Uber Technologies, Inc.
+ *
+ * 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 testcases.E020_objects_constructor;
+
+import motif.compiler.errors.parsing.ParsingError;
+
+import static com.google.common.truth.Truth.assertThat;
+
+public class Test {
+
+    public static ParsingError parsingError;
+
+    public static void run() {
+        assertThat(parsingError).isNotNull();
+    }
+}

it/src/main/java/testcases/E021_nullable_factory_method_return/Scope.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2018 Uber Technologies, Inc.
+ *
+ * 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 testcases.E021_nullable_factory_method_return;
+
+import javax.annotation.Nullable;
+
+@motif.Scope
+public interface Scope {
+
+    @motif.Objects
+    class Objects {
+
+        @Nullable
+        String string() {
+            return "s";
+        }
+    }
+}

it/src/main/java/testcases/E021_nullable_factory_method_return/Test.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2018 Uber Technologies, Inc.
+ *
+ * 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 testcases.E021_nullable_factory_method_return;
+
+import motif.compiler.errors.parsing.ParsingError;
+
+import static com.google.common.truth.Truth.assertThat;
+
+public class Test {
+
+    public static ParsingError parsingError;
+
+    public static void run() {
+        assertThat(parsingError).isNotNull();
+    }
+}

it/src/main/java/testcases/E022_nullable_factory_method_param/Scope.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2018 Uber Technologies, Inc.
+ *
+ * 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 testcases.E022_nullable_factory_method_param;
+
+import javax.annotation.Nullable;
+
+@motif.Scope
+public interface Scope {
+
+    @motif.Objects
+    class Objects {
+
+        Integer string(@Nullable String s) {
+            return 1;
+        }
+    }
+}

it/src/main/java/testcases/E022_nullable_factory_method_param/Test.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2018 Uber Technologies, Inc.
+ *
+ * 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 testcases.E022_nullable_factory_method_param;
+
+import motif.compiler.errors.parsing.ParsingError;
+
+import static com.google.common.truth.Truth.assertThat;
+
+public class Test {
+
+    public static ParsingError parsingError;
+
+    public static void run() {
+        assertThat(parsingError).isNotNull();
+    }
+}

it/src/main/java/testcases/E023_objects_fields_inherited/ObjectsParent.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2018 Uber Technologies, Inc.
+ *
+ * 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 testcases.E023_objects_fields_inherited;
+
+public class ObjectsParent {
+
+    private final String s = "s";
+
+    public String s() {
+        return s;
+    }
+}

it/src/main/java/testcases/E023_objects_fields_inherited/Scope.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2018 Uber Technologies, Inc.
+ *
+ * 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 testcases.E023_objects_fields_inherited;
+
+@motif.Scope
+public interface Scope {
+
+    @motif.Objects
+    class Objects extends ObjectsParent {}
+}