Merge pull request #18947 from tamasvajk/tamasvajk/java_empty_method

Java: Add new quality query to detect empty methods

java/ql/test/query-tests/EmptyMethod/Class1.java

@@ -0,0 +1,54 @@
+import org.aspectj.lang.annotation.Pointcut;
+
+public class Class1 {
+
+  // COMPLIANT
+  public void f() {
+    int i = 0;
+  }
+
+  // COMPLIANT
+  public void f1() {
+    // intentionally empty
+  }
+
+  // NON_COMPLIANT
+  public void f2() { } // $ Alert
+
+  // COMPLIANT - exception
+  @Pointcut()
+  public void f4() {
+  }
+
+  /**
+   * COMPLIANT - empty method with javadoc
+   */
+  public void f5() {
+  }
+
+  public abstract class TestInner {
+
+    public abstract void f(); // COMPLIANT - intentionally empty
+
+  }
+
+  public class Derived extends TestInner {
+
+    // COMPLIANT: with annotation
+    @Override
+    public void f() {
+    }
+
+    // COMPLIANT: native
+    public native int nativeMethod();
+  }
+
+  public interface TestInterface {
+
+    // NON_COMPLIANT
+    default void method() { } // $ Alert
+
+    void method2(); // COMPLIANT
+  }
+
+}

java/ql/test/query-tests/EmptyMethod/EmptyMethod.expected

@@ -0,0 +1,2 @@
+| Class1.java:16:15:16:16 | f2 | Empty method found. |
+| Class1.java:49:18:49:23 | method | Empty method found. |

java/ql/test/query-tests/EmptyMethod/EmptyMethod.qlref

@@ -0,0 +1,2 @@
+query: Language Abuse/EmptyMethod.ql
+postprocess: utils/test/InlineExpectationsTestQuery.ql

java/ql/test/query-tests/EmptyMethod/Test.java

@@ -0,0 +1,5 @@
+public class Test {
+  // COMPLIANT: allow empty method in test class
+  public void f() {
+  }
+}

java/ql/test/query-tests/EmptyMethod/options

@@ -0,0 +1 @@
+//semmle-extractor-options: --javac-args -cp ${testdir}/../../stubs/aspectj