jdk/test/langtools/tools/javac/AnonymousClass/AnonymousClassFlags.java

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/*
 * @test id=NoPreview
 * @bug 8161013
 * @summary Verify that anonymous class binaries have the correct flags set
 * @modules java.base/jdk.internal.misc
 * @comment Ensure that that this test is skipped if the test is run on a preview enabled
            VM as the compiled test class has not been forced into preview mode.
            Valhalla affects the outcome.
 * @requires !java.enablePreview
 * @run main AnonymousClassFlags
 */

/*
 * @test id=Preview
 * @bug 8161013
 * @summary Verify that anonymous class binaries have the correct flags set
 * @modules java.base/jdk.internal.misc
 * @enablePreview
 * @compile -XDforcePreview AnonymousClassFlags.java
 * @run main AnonymousClassFlags
 */

import java.util.*;
import java.nio.file.Path;
import java.nio.file.Paths;

import java.lang.classfile.*;
import java.lang.classfile.attribute.InnerClassInfo;
import java.lang.classfile.attribute.InnerClassesAttribute;

import jdk.internal.misc.PreviewFeatures;

public class AnonymousClassFlags {
    public static void main(String[] args) throws Exception {
        new AnonymousClassFlags().test(System.getProperty("test.classes", "."));
    }

    AnonymousClassFlags() {
        System.currentTimeMillis();
        super(); // Triggers force preview
    }

    // ACC_SUPER does not exist in InnerClasses before Value Objects
    private static final int EXPECTED_ACCESS_FLAGS = PreviewFeatures.isEnabled() ? ClassFile.ACC_IDENTITY : 0;

    /** Maps names of anonymous classes to their expected inner_class_access_flags */
    private static Map<String, Integer> anonClasses = new LinkedHashMap<>();

    // ******* TEST CASES ********

    static Object o1 = new Object() {
        { anonClasses.put(getClass().getName(), EXPECTED_ACCESS_FLAGS); }
    };

    static void staticMethod() {
        Object o2 = new Object() {
            { anonClasses.put(getClass().getName(), EXPECTED_ACCESS_FLAGS); }
        };
    }

    static {
        staticMethod();

        Object o3 = new Object() {
            { anonClasses.put(getClass().getName(), EXPECTED_ACCESS_FLAGS); }
        };
    }

    Object o4 = new Object() {
        { anonClasses.put(getClass().getName(), EXPECTED_ACCESS_FLAGS); }
    };

    void instanceMethod() {
        Object o5 = new Object() {
            { anonClasses.put(getClass().getName(), EXPECTED_ACCESS_FLAGS); }
        };
    }

    {
        instanceMethod();

        Object o6 = new Object() {
            { anonClasses.put(getClass().getName(), EXPECTED_ACCESS_FLAGS); }
        };
    }

    // ******* TEST IMPLEMENTATION ********

    void test(String classesDir) throws Exception {
        staticMethod();
        instanceMethod();

        Path outerFile = Paths.get(classesDir, getClass().getName() + ".class");
        ClassModel outerClass = ClassFile.of().parse(outerFile);
        for (Map.Entry<String,Integer> entry : anonClasses.entrySet()) {
            Path innerFile = Paths.get(classesDir, entry.getKey() + ".class");
            ClassModel innerClass = ClassFile.of().parse(innerFile);
            String name = entry.getKey();
            int expected = entry.getValue();
            assertInnerFlags(outerClass, name, expected);
            assertClassFlags(innerClass, name, expected);
            assertInnerFlags(innerClass, name, expected);
        }
    }

    static void assertClassFlags(ClassModel classFile, String name, int expected) {
        int mask = ClassFile.ACC_PUBLIC | ClassFile.ACC_FINAL | ClassFile.ACC_INTERFACE | ClassFile.ACC_ABSTRACT |
                   ClassFile.ACC_SYNTHETIC | ClassFile.ACC_ANNOTATION | ClassFile.ACC_ENUM | ClassFile.ACC_IDENTITY;
        int classExpected = (expected & mask) | ClassFile.ACC_SUPER;
        int classActual = classFile.flags().flagsMask();
        if (classActual != classExpected) {
            throw new AssertionError("Incorrect access_flags for class " + name +
                                     ": expected=" + classExpected + ", actual=" + classActual);
        }

    }

    static void assertInnerFlags(ClassModel classFile, String name, int expected) {
        int innerActual = lookupInnerFlags(classFile, name);
        if (innerActual != expected) {
            throw new AssertionError("Incorrect inner_class_access_flags for class " + name +
                                     " in class " + classFile.thisClass().asInternalName() +
                                     ": expected=" + expected + ", actual=" + innerActual);
        }
    }

    private static int lookupInnerFlags(ClassModel classFile, String innerName) {
        InnerClassesAttribute inners = classFile.findAttribute(Attributes.innerClasses()).orElse(null);
        if (inners == null) {
            throw new AssertionError("InnerClasses attribute missing in class " + classFile.thisClass().asInternalName());
        }
        for (InnerClassInfo info: inners.classes()) {
            String entryName = info.innerClass().asInternalName();
            if (innerName.equals(entryName)) {
                return info.flagsMask();
            }
        }
        throw new AssertionError("No InnerClasses entry in class " + classFile.thisClass().asInternalName() + " for class " + innerName);
    }

}