Java: add QL library for modeling Android components

Author: yh-semmle

java/ql/src/semmle/code/java/frameworks/android/Android.qll

@@ -0,0 +1,54 @@
+/**
+ * Provides classes and predicates for working with Android components.
+ */
+
+import java
+import semmle.code.xml.AndroidManifest
+
+/**
+ * An Android component. That is, either an activity, a service,
+ * a broadcast receiver, or a content provider.
+ */
+class AndroidComponent extends Class {
+  AndroidComponent() {
+    this.getASupertype*().hasQualifiedName("android.app", "Activity") or
+    this.getASupertype*().hasQualifiedName("android.app", "Service") or
+    this.getASupertype*().hasQualifiedName("android.content", "BroadcastReceiver") or
+    this.getASupertype*().hasQualifiedName("android.content", "ContentProvider")
+  }
+
+  /** The XML element corresponding to this Android component. */
+  AndroidComponentXmlElement getAndroidComponentXmlElement() {
+    result.getResolvedComponentName() = this.getQualifiedName()
+  }
+
+  /** Holds if this Android component is configured as `exported` in an `AndroidManifest.xml` file. */
+  predicate isExported() { getAndroidComponentXmlElement().isExported() }
+
+  /** Holds if this Android component has an intent filter configured in an `AndroidManifest.xml` file. */
+  predicate hasIntentFilter() { exists(getAndroidComponentXmlElement().getAnIntentFilterElement()) }
+}
+
+/** An Android activity. */
+class AndroidActivity extends AndroidComponent {
+  AndroidActivity() { this.getASupertype*().hasQualifiedName("android.app", "Activity") }
+}
+
+/** An Android service. */
+class AndroidService extends AndroidComponent {
+  AndroidService() { this.getASupertype*().hasQualifiedName("android.app", "Service") }
+}
+
+/** An Android broadcast receiver. */
+class AndroidBroadcastReceiver extends AndroidComponent {
+  AndroidBroadcastReceiver() {
+    this.getASupertype*().hasQualifiedName("android.content", "BroadcastReceiver")
+  }
+}
+
+/** An Android content provider. */
+class AndroidContentProvider extends AndroidComponent {
+  AndroidContentProvider() {
+    this.getASupertype*().hasQualifiedName("android.content", "ContentProvider")
+  }
+}