Forbid modules who extend from non-Object class types.

Closes #188.

compiler/src/it/module-type-validation/invoker.properties

@@ -0,0 +1 @@
+invoker.buildResult=failure

compiler/src/it/module-type-validation/pom.xml

@@ -0,0 +1,53 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Copyright (C) 2013 Square, 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.
+-->
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>com.example.dagger.tests</groupId>
+  <artifactId>module-type-validation</artifactId>
+  <version>HEAD-SNAPSHOT</version>
+  <dependencies>
+    <dependency>
+      <groupId>@dagger.groupId@</groupId>
+      <artifactId>dagger</artifactId>
+      <version>@dagger.version@</version>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.0</version>
+        <configuration>
+          <source>1.5</source>
+          <target>1.5</target>
+          <!-- workaround for http://jira.codehaus.org/browse/MCOMPILER-202 -->
+          <forceJavacCompilerUse>true</forceJavacCompilerUse>
+        </configuration>
+        <dependencies>
+          <dependency>
+            <groupId>@dagger.groupId@</groupId>
+            <artifactId>dagger-compiler</artifactId>
+            <version>@dagger.version@</version>
+          </dependency>
+        </dependencies>
+      </plugin>
+    </plugins>
+  </build>
+</project>

compiler/src/it/module-type-validation/src/main/java/test/TestModule.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2013 Square, 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 test;
+
+import dagger.Module;
+
+@Module
+class ThreadModule extends Thread {
+}
+
+@Module
+enum EnumModule {
+}
+
+@Module
+interface InterfaceModule {
+}

compiler/src/it/module-type-validation/verify.bsh

@@ -0,0 +1,10 @@
+import dagger.testing.it.BuildLogValidator;
+import java.io.File;
+
+File buildLog = new File(basedir, "build.log");
+new BuildLogValidator().assertHasText(buildLog, new String[]{
+    "Modules must not extend from other classes: test.ThreadModule"});
+new BuildLogValidator().assertHasText(buildLog, new String[]{
+    "Modules must be classes: test.EnumModule"});
+new BuildLogValidator().assertHasText(buildLog, new String[]{
+    "Modules must be classes: test.InterfaceModule"});

compiler/src/main/java/dagger/internal/codegen/ProvidesProcessor.java

@@ -45,6 +45,7 @@
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.element.VariableElement;
 import javax.lang.model.type.TypeMirror;
+import javax.lang.model.util.Elements;
 import javax.tools.Diagnostic;
 import javax.tools.JavaFileObject;
 
@@ -71,7 +72,6 @@ public final class ProvidesProcessor extends AbstractProcessor {
     return SourceVersion.latestSupported();
   }
 
-  // TODO: include @Provides methods from the superclass
   @Override public boolean process(Set<? extends TypeElement> types, RoundEnvironment env) {
     remainingTypes.putAll(providerMethodsByClass(env));
     for (Iterator<String> i = remainingTypes.keySet().iterator(); i.hasNext();) {
@@ -148,14 +148,27 @@ private Map<String, List<ExecutableElement>> providerMethodsByClass(RoundEnviron
       methods.add(providerMethodAsExecutable);
     }
 
+    Elements elementUtils = processingEnv.getElementUtils();
+    TypeMirror objectType = elementUtils.getTypeElement("java.lang.Object").asType();
+
     // Catch any stray modules without @Provides since their entry points
     // should still be registered and a ModuleAdapter should still be written.
-    for (Element type : env.getElementsAnnotatedWith(Module.class)) {
-      if (type.getKind().equals(ElementKind.CLASS)) {
-        String moduleType = ((TypeElement) type).getQualifiedName().toString();
-        if (result.containsKey(moduleType)) continue;
-        result.put(moduleType, new ArrayList<ExecutableElement>());
+    for (Element module : env.getElementsAnnotatedWith(Module.class)) {
+      if (!module.getKind().equals(ElementKind.CLASS)) {
+        error("Modules must be classes: " + module, module);
+        continue;
+      }
+
+      TypeElement moduleType = (TypeElement) module;
+
+      // Verify that all modules do not extend from non-Object types.
+      if (!moduleType.getSuperclass().equals(objectType)) {
+        error("Modules must not extend from other classes: " + module, module);
       }
+
+      String moduleName = moduleType.getQualifiedName().toString();
+      if (result.containsKey(moduleName)) continue;
+      result.put(moduleName, new ArrayList<ExecutableElement>());
     }
     return result;
   }

core/src/main/java/dagger/internal/plugins/reflect/ReflectivePlugin.java

@@ -52,6 +52,10 @@ public final class ReflectivePlugin implements Plugin {
     if (annotation == null) {
       throw new IllegalArgumentException("No @Module on " + moduleClass.getName());
     }
+    if (moduleClass.getSuperclass() != Object.class) {
+      throw new IllegalArgumentException(
+          "Modules must not extend from other classes: " + moduleClass.getName());
+    }
     return (ModuleAdapter<T>) new ReflectiveModuleAdapter(moduleClass, annotation);
   }
 

core/src/test/java/dagger/ModuleIncludesTest.java → core/src/test/java/dagger/ModuleTest.java

@@ -24,7 +24,7 @@
 import static org.junit.Assert.fail;
 
 @RunWith(JUnit4.class)
-public final class ModuleIncludesTest {
+public final class ModuleTest {
   static class TestEntryPoint {
     @Inject String s;
   }
@@ -181,4 +181,16 @@ static class ChildModuleMissingModuleAnnotation {}
   public void childModuleMissingModuleAnnotation() {
     ObjectGraph.create(new ChildModuleMissingModuleAnnotation());
   }
+
+  @Module
+  static class ThreadModule extends Thread {}
+
+  @Test public void moduleExtendingClassThrowsException() {
+    try {
+      ObjectGraph.create(new ThreadModule());
+      fail();
+    } catch (IllegalArgumentException e) {
+      assertThat(e.getMessage()).startsWith("Modules must not extend from other classes: ");
+    }
+  }
 }