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/*
* Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2018 SAP SE. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/**
* @test
* @summary Check that the verbose message of the AME is printed correctly.
* @requires !(os.arch=="arm") & vm.flavor == "server" & !vm.emulatedClient & vm.compMode=="Xmixed" & (!vm.graal.enabled | vm.opt.TieredCompilation == true) & (vm.opt.TieredStopAtLevel == null | vm.opt.TieredStopAtLevel==4)
* @library /test/lib /
* @build sun.hotspot.WhiteBox
* @run driver ClassFileInstaller sun.hotspot.WhiteBox sun.hotspot.WhiteBox$WhiteBoxPermission
* @compile AbstractMethodErrorTest.java
* @compile AME1_E.jasm AME2_C.jasm AME3_C.jasm AME4_E.jasm AME5_B.jasm AME6_B.jasm
* @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
* -XX:CompileThreshold=1000 -XX:-BackgroundCompilation -XX:-Inline
* -XX:CompileCommand=exclude,AbstractMethodErrorTest::test_ame1
* AbstractMethodErrorTest
*/
import sun.hotspot.WhiteBox;
import compiler.whitebox.CompilerWhiteBoxTest;
import java.lang.reflect.Method;
// This test assembles an errorneous installation of classes.
// First, compile the test by @compile. This results in a legal set
// of classes.
// Then, with jasm, generate incompatible classes that overwrite
// the class files in the build directory.
// Last, call the real test throwing an AbstractMethodError and
// check the message generated.
public class AbstractMethodErrorTest {
private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
private static boolean enableChecks = true;
private static boolean compile(Class<?> clazz, String name) {
try {
Method method = clazz.getMethod(name);
boolean enqueued = WHITE_BOX.enqueueMethodForCompilation(method, CompilerWhiteBoxTest.COMP_LEVEL_FULL_OPTIMIZATION);
if (!enqueued) {
System.out.println("Warning: Blocking compilation failed for " + clazz.getName() + "." + name + " (timeout?)");
return false;
} else if (!WHITE_BOX.isMethodCompiled(method)) {
throw new RuntimeException(clazz.getName() + "." + name + " is not compiled");
}
} catch (NoSuchMethodException e) {
throw new RuntimeException(clazz.getName() + "." + name + " not found", e);
}
return true;
}
public static boolean setup_test() {
// Assure all exceptions are loaded.
new AbstractMethodError();
new IncompatibleClassChangeError();
enableChecks = false;
// Warmup
System.out.println("warmup:");
test_ame5_compiled_vtable_stub();
test_ame6_compiled_itable_stub();
enableChecks = true;
// Compile
if (!compile(AbstractMethodErrorTest.class, "test_ame5_compiled_vtable_stub") ||
!compile(AbstractMethodErrorTest.class, "test_ame6_compiled_itable_stub") ||
!compile(AME5_C.class, "mc") ||
!compile(AME5_D.class, "mc") ||
!compile(AME5_E.class, "mc") ||
!compile(AME6_C.class, "mc") ||
!compile(AME6_D.class, "mc") ||
!compile(AME6_E.class, "mc")) {
return false;
}
System.out.println("warmup done.");
return true;
}
private static String expectedErrorMessageAME1_1 =
"Missing implementation of resolved method 'abstract " +
"java.lang.String anAbstractMethod()' of abstract class AME1_B.";
private static String expectedErrorMessageAME1_2 =
"Receiver class AME1_E does not define or inherit an implementation of the " +
"resolved method 'abstract java.lang.String aFunctionOfMyInterface()' of " +
"interface AME1_C.";
public static void test_ame1() {
AME1_B objectAbstract = new AME1_D();
AME1_C objectInterface = new AME1_D();
objectInterface.secondFunctionOfMyInterface();
objectAbstract.anAbstractMethod();
objectInterface.aFunctionOfMyInterface();
try {
objectAbstract = new AME1_E();
// AbstractMethodError gets thrown in the interpreter at:
// InterpreterGenerator::generate_abstract_entry
objectAbstract.anAbstractMethod();
throw new RuntimeException("Expected AbstractRuntimeError was not thrown.");
} catch (AbstractMethodError e) {
String errorMsg = e.getMessage();
if (errorMsg == null) {
throw new RuntimeException("Caught AbstractMethodError with empty message.");
} else if (!errorMsg.equals(expectedErrorMessageAME1_1)) {
System.out.println("Expected: " + expectedErrorMessageAME1_1 + "\n" +
"but got: " + errorMsg);
throw new RuntimeException("Wrong error message of AbstractMethodError.");
}
} catch (RuntimeException e) {
throw e;
} catch (Throwable e) {
throw new RuntimeException("Caught unexpected exception: " + e);
}
try {
objectInterface = new AME1_E();
// AbstractMethodError gets thrown in:
// TemplateTable::invokeinterface or C-Interpreter loop
objectInterface.aFunctionOfMyInterface();
throw new RuntimeException("Expected AbstractRuntimeError was not thrown.");
} catch (AbstractMethodError e) {
String errorMsg = e.getMessage();
if (errorMsg == null) {
throw new RuntimeException("Caught AbstractMethodError with empty message.");
} else if (!errorMsg.equals(expectedErrorMessageAME1_2)) {
// Thrown via InterpreterRuntime::throw_AbstractMethodErrorVerbose().
System.out.println("Expected: " + expectedErrorMessageAME1_2 + "\n" +
"but got: " + errorMsg);
throw new RuntimeException("Wrong error message of AbstractMethodError.");
} else {
System.out.println("Passed with message: " + errorMsg);
}
} catch (Throwable e) {
throw new RuntimeException("Caught unexpected exception: " + e);
}
}
private static String expectedErrorMessageAME2_Interpreted =
"Missing implementation of resolved method 'abstract " +
"void aFunctionOfMyInterface()' of interface AME2_A.";
private static String expectedErrorMessageAME2_Compiled =
"Receiver class AME2_C does not define or inherit an implementation of the resolved method " +
"'abstract void aFunctionOfMyInterface()' of interface AME2_A.";
public AbstractMethodErrorTest() throws InstantiationException, IllegalAccessException {
try {
AME2_B myAbstract = new ImplementsAllFunctions();
myAbstract.fun2();
myAbstract.aFunctionOfMyInterface();
// AME2_C does not implement the method
// aFunctionOfMyInterface(). Expected runtime behavior is
// throwing an AbstractMethodError.
// The error will be thrown via throw_AbstractMethodErrorWithMethod()
// if the template interpreter calls an abstract method by
// entering the abstract method entry.
myAbstract = new AME2_C();
myAbstract.fun2();
myAbstract.aFunctionOfMyInterface();
} catch (SecurityException e) {
e.printStackTrace();
}
}
// Loop so that method gets eventually compiled/osred.
public static void test_ame2() throws Exception {
boolean seenInterpreted = false;
boolean seenCompiled = false;
// Loop to test both, the interpreted and the compiled case.
for (int i = 0; i < 10000 && !(seenInterpreted && seenCompiled); ++i) {
try {
// Supposed to throw AME with verbose message.
new AbstractMethodErrorTest();
throw new RuntimeException("Expected AbstractMethodError was not thrown.");
} catch (AbstractMethodError e) {
String errorMsg = e.getMessage();
// Check the message obtained.
if (errorMsg == null) {
throw new RuntimeException("Caught AbstractMethodError with empty message.");
} else if (errorMsg.equals(expectedErrorMessageAME2_Interpreted)) {
seenInterpreted = true;
} else if (errorMsg.equals(expectedErrorMessageAME2_Compiled)) {
// Sparc and the other platforms behave differently here:
// Sparc throws the exception via SharedRuntime::handle_wrong_method_abstract(),
// x86, ppc and s390 via LinkResolver::runtime_resolve_virtual_method(). Thus,
// sparc misses the test case for LinkResolver::runtime_resolve_virtual_method().
seenCompiled = true;
} else {
System.out.println("Expected: " + expectedErrorMessageAME2_Interpreted + "\n" +
"or: " + expectedErrorMessageAME2_Compiled + "\n" +
"but got: " + errorMsg);
throw new RuntimeException("Wrong error message of AbstractMethodError.");
}
}
}
if (!(seenInterpreted && seenCompiled)) {
if (seenInterpreted) { System.out.println("Saw interpreted message."); }
if (seenCompiled) { System.out.println("Saw compiled message."); }
throw new RuntimeException("Test did not produce wrong error messages for AbstractMethodError, " +
"but it did not test both cases (interpreted and compiled).");
}
}
private static String expectedErrorMessageAME3_1 =
"Receiver class AME3_C does not define or inherit an implementation of the resolved method " +
"'void ma()' of class AME3_A. Selected method is 'abstract void AME3_B.ma()'.";
// Testing abstract class that extends a class that has an implementation.
// Loop so that method gets eventually compiled/osred.
public static void test_ame3_1() throws Exception {
AME3_A c = new AME3_C();
try {
// Supposed to throw AME with verbose message.
c.ma();
throw new RuntimeException("Expected AbstractMethodError was not thrown.");
} catch (AbstractMethodError e) {
String errorMsg = e.getMessage();
// Check the message obtained.
if (errorMsg == null) {
throw new RuntimeException("Caught AbstractMethodError with empty message.");
} else if (errorMsg.equals(expectedErrorMessageAME3_1)) {
// Expected test case thrown via LinkResolver::runtime_resolve_virtual_method().
System.out.println("Passed with message: " + errorMsg);
} else {
System.out.println("Expected: " + expectedErrorMessageAME3_1 + "\n" +
"but got: " + errorMsg);
throw new RuntimeException("Wrong error message of AbstractMethodError.");
}
}
}
private static String expectedErrorMessageAME3_2 =
"Receiver class AME3_C does not define or inherit an implementation of " +
"the resolved method 'abstract void ma()' of abstract class AME3_B.";
// Testing abstract class that extends a class that has an implementation.
// Loop so that method gets eventually compiled/osred.
public static void test_ame3_2() throws Exception {
AME3_C c = new AME3_C();
try {
// Supposed to throw AME with verbose message.
c.ma();
throw new RuntimeException("Expected AbstractMethodError was not thrown.");
} catch (AbstractMethodError e) {
String errorMsg = e.getMessage();
// Check the message obtained.
if (errorMsg == null) {
throw new RuntimeException("Caught AbstractMethodError with empty message.");
} else if (errorMsg.equals(expectedErrorMessageAME3_2)) {
// Expected test case thrown via LinkResolver::runtime_resolve_virtual_method().
System.out.println("Passed with message: " + errorMsg);
} else {
System.out.println("Expected: " + expectedErrorMessageAME3_2 + "\n" +
"but got: " + errorMsg);
throw new RuntimeException("Wrong error message of AbstractMethodError.");
}
}
}
private static String expectedErrorMessageAME4 =
"Missing implementation of resolved method 'abstract void ma()' of " +
"abstract class AME4_B.";
// Testing abstract class that extends a class that has an implementation.
public static void test_ame4() throws Exception {
AME4_C c = new AME4_C();
AME4_D d = new AME4_D();
AME4_E e = new AME4_E(); // Errorneous.
AME4_A a;
try {
// Test: calls errorneous e.ma() in the last iteration.
final int iterations = 10;
for (int i = 0; i < iterations; i++) {
a = e;
if (i % 2 == 0 && i < iterations - 1) {
a = c;
}
if (i % 2 == 1 && i < iterations - 1) {
a = d;
}
// AbstractMethodError gets thrown in the interpreter at:
// InterpreterGenerator::generate_abstract_entry
a.ma();
}
throw new RuntimeException("Expected AbstractMethodError was not thrown.");
} catch (AbstractMethodError exc) {
System.out.println();
String errorMsg = exc.getMessage();
// Check the message obtained.
if (enableChecks && errorMsg == null) {
throw new RuntimeException("Caught AbstractMethodError with empty message.");
} else if (errorMsg.equals(expectedErrorMessageAME4)) {
// Expected test case.
System.out.println("Passed with message: " + errorMsg);
} else if (enableChecks) {
System.out.println("Expected: " + expectedErrorMessageAME4 + "\n" +
"but got: " + errorMsg);
throw new RuntimeException("Wrong error message of AbstractMethodError.");
}
}
}
private static String expectedErrorMessageAME5_VtableStub =
"Receiver class AME5_B does not define or inherit an implementation of the resolved method 'abstract void mc()' " +
"of abstract class AME5_A.";
// AbstractMethodErrors detected in vtable stubs.
// Note: How can we verify that we really stepped through the vtable stub?
// - Bimorphic inlining should not happen since we have no profiling data when
// we compile the method
// - As a result, an inline cache call should be generated
// - This inline cache call is patched into a real vtable call at the first
// re-resolve, which happens constantly during the first 10 iterations of the loop.
// => we should be fine! :-)
public static void test_ame5_compiled_vtable_stub() {
// Allocated the objects we need and call a valid method.
boolean caught_ame = false;
AME5_B b = new AME5_B();
AME5_C c = new AME5_C();
AME5_D d = new AME5_D();
AME5_E e = new AME5_E();
b.ma();
c.ma();
d.ma();
e.ma();
try {
final int iterations = 10;
// Test: calls b.c() in the last iteration.
for (int i = 0; i < iterations; i++) {
AME5_A a = b;
if (i % 3 == 0 && i < iterations - 1) {
a = c;
}
if (i % 3 == 1 && i < iterations - 1) {
a = d;
}
if (i % 3 == 2 && i < iterations - 1) {
a = e;
}
a.mc();
}
System.out.println();
} catch (AbstractMethodError exc) {
caught_ame = true;
System.out.println();
String errorMsg = exc.getMessage();
if (enableChecks && errorMsg == null) {
System.out.println(exc);
throw new RuntimeException("Empty error message of AbstractMethodError.");
}
if (enableChecks &&
!errorMsg.equals(expectedErrorMessageAME5_VtableStub)) {
// Thrown via SharedRuntime::handle_wrong_method_abstract().
System.out.println("Expected: " + expectedErrorMessageAME5_VtableStub + "\n" +
"but got: " + errorMsg);
System.out.println(exc);
throw new RuntimeException("Wrong error message of AbstractMethodError.");
}
if (enableChecks) {
System.out.println("Passed with message: " + errorMsg);
}
} catch (Throwable exc) {
throw exc;
}
// Check that we got the exception at some point.
if (enableChecks && !caught_ame) {
throw new RuntimeException("Expected AbstractMethodError was not thrown.");
}
}
private static String expectedErrorMessageAME6_ItableStub =
"Receiver class AME6_B does not define or inherit an implementation of the resolved" +
" method 'abstract void mc()' of interface AME6_A.";
// -------------------------------------------------------------------------
// AbstractMethodErrors detected in itable stubs.
// Note: How can we verify that we really stepped through the itable stub?
// - Bimorphic inlining should not happen since we have no profiling data when
// we compile the method
// - As a result, an inline cache call should be generated
// - This inline cache call is patched into a real vtable call at the first
// re-resolve, which happens constantly during the first 10 iterations of the loop.
// => we should be fine! :-)
public static void test_ame6_compiled_itable_stub() {
// Allocated the objects we need and call a valid method.
boolean caught_ame = false;
AME6_B b = new AME6_B();
AME6_C c = new AME6_C();
AME6_D d = new AME6_D();
AME6_E e = new AME6_E();
b.ma();
c.ma();
d.ma();
e.ma();
try {
final int iterations = 10;
// Test: calls b.c() in the last iteration.
for (int i = 0; i < iterations; i++) {
AME6_A a = b;
if (i % 3 == 0 && i < iterations - 1) {
a = c;
}
if (i % 3 == 1 && i < iterations - 1) {
a = d;
}
if (i % 3 == 2 && i < iterations - 1) {
a = e;
}
a.mc();
}
System.out.println();
} catch (AbstractMethodError exc) {
caught_ame = true;
System.out.println();
String errorMsg = exc.getMessage();
if (enableChecks && errorMsg == null) {
System.out.println(exc);
throw new RuntimeException("Empty error message of AbstractMethodError.");
}
if (enableChecks &&
!errorMsg.equals(expectedErrorMessageAME6_ItableStub)) {
// Thrown via LinkResolver::runtime_resolve_interface_method().
System.out.println("Expected: " + expectedErrorMessageAME6_ItableStub + "\n" +
"but got: " + errorMsg);
System.out.println(exc);
throw new RuntimeException("Wrong error message of AbstractMethodError.");
}
if (enableChecks) {
System.out.println("Passed with message: " + errorMsg);
}
} catch (Throwable exc) {
throw exc;
}
// Check that we got the exception at some point.
if (enableChecks && !caught_ame) {
throw new RuntimeException("Expected AbstractMethodError was not thrown.");
}
}
public static void main(String[] args) throws Exception {
if (!setup_test()) {
return;
}
test_ame1();
test_ame2();
test_ame3_1();
test_ame3_2();
test_ame4();
test_ame5_compiled_vtable_stub();
test_ame6_compiled_itable_stub();
}
}
// Helper classes to test abstract method error.
//
// Errorneous versions of these classes are implemented in java
// assembler.
// -------------------------------------------------------------------------
// This error should be detected interpreted.
//
// Class hierachy:
//
// C // interface, defines aFunctionOfMyInterface()
// |
// A | // interface
// | |
// B | // abstract class, defines anAbstractMethod()
// \ /
// E // errorneous class implementation lacks methods C::aFunctionOfMyInterface()
// B::anAbstractMethod()
interface AME1_A {
public String firstFunctionOfMyInterface0();
public String secondFunctionOfMyInterface0();
}
abstract class AME1_B implements AME1_A {
abstract public String firstAbstractMethod();
abstract public String secondAbstractMethod();
abstract public String anAbstractMethod();
}
interface AME1_C {
public String firstFunctionOfMyInterface();
public String secondFunctionOfMyInterface();
public String aFunctionOfMyInterface();
}
class AME1_D extends AME1_B implements AME1_C {
public AME1_D() {
}
public String firstAbstractMethod() {
return this.getClass().getName();
}
public String secondAbstractMethod() {
return this.getClass().getName();
}
public String anAbstractMethod() {
return this.getClass().getName();
}
public String firstFunctionOfMyInterface0() {
return this.getClass().getName();
}
public String secondFunctionOfMyInterface0() {
return this.getClass().getName();
}
public String firstFunctionOfMyInterface() {
return this.getClass().getName();
}
public String secondFunctionOfMyInterface() {
return this.getClass().getName();
}
public String aFunctionOfMyInterface() {
return this.getClass().getName();
}
}
class AME1_E extends AME1_B implements AME1_C {
public AME1_E() {
}
public String firstAbstractMethod() {
return this.getClass().getName();
}
public String secondAbstractMethod() {
return this.getClass().getName();
}
// This method is missing in the .jasm implementation.
public String anAbstractMethod() {
return this.getClass().getName();
}
public String firstFunctionOfMyInterface0() {
return this.getClass().getName();
}
public String secondFunctionOfMyInterface0() {
return this.getClass().getName();
}
public String firstFunctionOfMyInterface() {
return this.getClass().getName();
}
public String secondFunctionOfMyInterface() {
return this.getClass().getName();
}
// This method is missing in the .jasm implementation.
public String aFunctionOfMyInterface() {
return this.getClass().getName();
}
}
// -------------------------------------------------------------------------
// This error should be detected interpreted.
//
// Class hierachy:
//
// A // an interface declaring aFunctionOfMyInterface()
// |
// B // an abstract class
// |
// C // errorneous implementation lacks method A::aFunctionOfMyInterface()
//
interface AME2_A {
public void aFunctionOfMyInterface();
}
abstract class AME2_B implements AME2_A {
abstract public void fun2();
}
class ImplementsAllFunctions extends AME2_B {
public ImplementsAllFunctions() {}
public void fun2() {
//System.out.print("You called public void ImplementsAllFunctions::fun2().\n");
}
public void aFunctionOfMyInterface() {
//System.out.print("You called public void ImplementsAllFunctions::aFunctionOfMyInterface()\n");
}
}
class AME2_C extends AME2_B {
public AME2_C() {}
public void fun2() {
//System.out.print("You called public void AME2_C::fun2().\n");
}
// This method is missing in the .jasm implementation.
public void aFunctionOfMyInterface() {
//System.out.print("You called public void AME2_C::aFunctionOfMyInterface()\n");
}
}
// -----------------------------------------------------------------------
// Test AbstractMethod error shadowing existing implementation.
//
// Class hierachy:
//
// A // a class implementing m()
// |
// B // an abstract class defining m() abstract
// |
// C // an errorneous class lacking an implementation of m()
//
class AME3_A {
public void ma() {
System.out.print("A.ma() ");
}
}
abstract class AME3_B extends AME3_A {
public abstract void ma();
}
class AME3_C extends AME3_B {
// This method is missing in the .jasm implementation.
public void ma() {
System.out.print("C.ma() ");
}
}
// -----------------------------------------------------------------------
// Test AbstractMethod error shadowing existing implementation. In
// this test there are several subclasses of the abstract class.
//
// Class hierachy:
//
// A // A: a class implementing ma()
// |
// B // B: an abstract class defining ma() abstract
// / | \
// C D E // E: an errorneous class lacking an implementation of ma()
//
class AME4_A {
public void ma() {
System.out.print("A.ma() ");
}
}
abstract class AME4_B extends AME4_A {
public abstract void ma();
}
class AME4_C extends AME4_B {
public void ma() {
System.out.print("C.ma() ");
}
}
class AME4_D extends AME4_B {
public void ma() {
System.out.print("D.ma() ");
}
}
class AME4_E extends AME4_B {
// This method is missing in the .jasm implementation.
public void ma() {
System.out.print("E.ma() ");
}
}
// -------------------------------------------------------------------------
// This error should be detected while processing the vtable stub.
//
// Class hierachy:
//
// A__ // abstract
// /|\ \
// C D E \
// B // Bad class, missing method implementation.
//
// Test:
// - Call D.mc() / E.mc() / F.mc() several times to force real vtable call constrution
// - Call errorneous B.mc() in the end to raise the AbstraceMethodError
abstract class AME5_A {
public abstract void ma();
public abstract void mb();
public abstract void mc();
}
class AME5_B extends AME5_A {
public void ma() {
System.out.print("B.ma() ");
}
public void mb() {
System.out.print("B.mb() ");
}
// This method is missing in the .jasm implementation.
public void mc() {
System.out.print("B.mc() ");
}
}
class AME5_C extends AME5_A {
public void ma() {
System.out.print("C.ma() ");
}
public void mb() {
System.out.print("C.mb() ");
}
public void mc() {
System.out.print("C.mc() ");
}
}
class AME5_D extends AME5_A {
public void ma() {
System.out.print("D.ma() ");
}
public void mb() {
System.out.print("D.mb() ");
}
public void mc() {
System.out.print("D.mc() ");
}
}
class AME5_E extends AME5_A {
public void ma() {
System.out.print("E.ma() ");
}
public void mb() {
System.out.print("E.mb() ");
}
public void mc() {
System.out.print("E.mc() ");
}
}
//-------------------------------------------------------------------------
// Test AbstractMethod error detected while processing
// the itable stub.
//
// Class hierachy:
//
// A__ (interface)
// /|\ \
// C D E \
// B (bad class, missing method)
//
// Test:
// - Call D.mc() / E.mc() / F.mc() several times to force real itable call constrution
// - Call errorneous B.mc() in the end to raise the AbstraceMethodError
interface AME6_A {
abstract void ma();
abstract void mb();
abstract void mc();
}
class AME6_B implements AME6_A {
public void ma() {
System.out.print("B.ma() ");
}
public void mb() {
System.out.print("B.mb() ");
}
// This method is missing in the .jasm implementation.
public void mc() {
System.out.print("B.mc() ");
}
}
class AME6_C implements AME6_A {
public void ma() {
System.out.print("C.ma() ");
}
public void mb() {
System.out.print("C.mb() ");
}
public void mc() {
System.out.print("C.mc() ");
}
}
class AME6_D implements AME6_A {
public void ma() {
System.out.print("D.ma() ");
}
public void mb() {
System.out.print("D.mb() ");
}
public void mc() {
System.out.print("D.mc() ");
}
}
class AME6_E implements AME6_A {
public void ma() {
System.out.print("E.ma() ");
}
public void mb() {
System.out.print("E.mb() ");
}
public void mc() {
System.out.print("E.mc() ");
}
}