test/hotspot/jtreg/runtime/LoaderConstraints/vtableLdrConstraint/Test.java

rev 49800 : 8199852: Print more information about class loaders in LinkageErrors.
Reviewed-by: dholmes

*** 1,7 ****
  /*
!  * Copyright (c) 2017, Oracle and/or its affiliates. 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.
--- 1,7 ----
  /*
!  * Copyright (c) 2017, 2018, Oracle and/or its affiliates. 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.
*** 21,31 ****
   * questions.
   */
  
  /*
   * @test
!  * @bug 8186092
   * @compile ../common/Foo.java
   *          ../common/J.java
   *          I.java
   *          ../common/C.jasm
   *          Task.java
--- 21,31 ----
   * questions.
   */
  
  /*
   * @test
!  * @bug 8186092 8199852
   * @compile ../common/Foo.java
   *          ../common/J.java
   *          I.java
   *          ../common/C.jasm
   *          Task.java
*** 33,63 ****
   * @run main/othervm Test
   */
  
  public class Test {
  
      // Test that the error message is correct when a loader constraint error is
      // detected during vtable creation.
      //
      // In this test, during vtable creation for class Task, method "Task.m()LFoo;"
      // overrides "J.m()LFoo;".  But, Task's class Foo and super type J's class Foo
      // are different.  So, a LinkageError exception should be thrown because the
      // loader constraint check will fail.
!     public static void main(String args[]) throws Exception {
!         Class<?> c = Foo.class; // forces standard class loader to load Foo
!         ClassLoader l = new PreemptingClassLoader("Task", "Foo", "I");
!         l.loadClass("Foo");
          try {
!             l.loadClass("Task").newInstance();
              throw new RuntimeException("Expected LinkageError exception not thrown");
          } catch (LinkageError e) {
!             if (!e.getMessage().contains(
!                     "loader constraint violation for class Task: when selecting overriding method") ||
!                 !e.getMessage().contains(
!                     "for its super type J have different Class objects for the type Foo")) {
!                 throw new RuntimeException("Wrong LinkageError exception thrown: " + e.getMessage());
              }
          }
      }
  
  }
  
--- 33,89 ----
   * @run main/othervm Test
   */
  
  public class Test {
  
+     static String expectedErrorMessage1 =
+         "loader constraint violation for class test.Task: " +
+         "when selecting overriding method test.Task.m()Ltest/Foo; " +
+         "the class loader \"<unnamed>\" (instance of PreemptingClassLoader, " +
+         "child of \"app\" jdk.internal.loader.ClassLoaders$AppClassLoader) " +
+         "of the selected method's type test.Task, " +
+         "and the class loader \"app\" (instance of jdk.internal.loader.ClassLoaders$AppClassLoader) " +
+         "for its super type test.J " +
+         "have different Class objects for the type test.Foo used in the signature";
+ 
+     static String expectedErrorMessage2 =
+         "loader constraint violation for class test.Task: " +
+         "when selecting overriding method test.Task.m()Ltest/Foo; " +
+         "the class loader \"VtableLdrCnstrnt_Test_Loader\" (instance of PreemptingClassLoader, " +
+         "child of \"app\" jdk.internal.loader.ClassLoaders$AppClassLoader) " +
+         "of the selected method's type test.Task, " +
+         "and the class loader \"app\" (instance of jdk.internal.loader.ClassLoaders$AppClassLoader) " +
+         "for its super type test.J " +
+         "have different Class objects for the type test.Foo used in the signature";
+ 
      // Test that the error message is correct when a loader constraint error is
      // detected during vtable creation.
      //
      // In this test, during vtable creation for class Task, method "Task.m()LFoo;"
      // overrides "J.m()LFoo;".  But, Task's class Foo and super type J's class Foo
      // are different.  So, a LinkageError exception should be thrown because the
      // loader constraint check will fail.
!     public static void test(String loaderName, String expectedErrorMessage) throws Exception {
!         Class<?> c = test.Foo.class; // Forces standard class loader to load Foo.
!         String[] classNames = {"test.Task", "test.Foo", "test.I"};
!         ClassLoader l = new PreemptingClassLoader(loaderName, classNames);
!         l.loadClass("test.Foo");
          try {
!             l.loadClass("test.Task").newInstance();
              throw new RuntimeException("Expected LinkageError exception not thrown");
          } catch (LinkageError e) {
!             String errorMsg = e.getMessage();
!             if (!errorMsg.equals(expectedErrorMessage)) {
!                 System.out.println("Expected: " + expectedErrorMessage + "\n" +
!                                    "but got:  " + errorMsg);
!                 throw new RuntimeException("Wrong LinkageError exception thrown: " + errorMsg);
              }
+             System.out.println("Passed with message: " + errorMsg);
          }
      }
  
+     public static void main(String args[]) throws Exception {
+         test(null, expectedErrorMessage1);
+         test("VtableLdrCnstrnt_Test_Loader", expectedErrorMessage2);
+     }
  }