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

rev 49654 : 8199852: Print more information about class loaders in LinkageErrors.

@@ -33,31 +33,72 @@
  * @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 instance of PreemptingClassLoader " +
+        "(parent: \"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, " +
+        "parent: \"platform\" jdk.internal.loader.ClassLoaders$PlatformClassLoader) 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 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");
+    public static void test1() throws Exception {
+        Class<?> c = test.Foo.class; // forces standard class loader to load Foo
+        ClassLoader l = new PreemptingClassLoader("test.Task", "test.Foo", "test.I");
+        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(expectedErrorMessage1)) {
+                System.out.println("Expected: " + expectedErrorMessage1 + "\n" +
+                                   "but got:  " + errorMsg);
+                throw new RuntimeException("Wrong LinkageError exception thrown: " + errorMsg);
+            }
+            System.out.println("Passed with message: " + errorMsg);
+        }
+    }
+
+    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, " +
+        "parent: \"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$AppClassLoader, " +
+        "parent: \"platform\" jdk.internal.loader.ClassLoaders$PlatformClassLoader) for its super type test.J " +
+        "have different Class objects for the type test.Foo used in the signature";
+
+    // Same as test1, but ClassLoader has a name.
+    public static void test2() 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("VtableLdrCnstrnt_Test_Loader", classNames);
+        l.loadClass("test.Foo");
         try {
-            l.loadClass("Task").newInstance();
+            l.loadClass("test.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());
+            String errorMsg = e.getMessage();
+            if (!errorMsg.equals(expectedErrorMessage2)) {
+                System.out.println("Expected: " + expectedErrorMessage2 + "\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 {
+        test1();
+        test2();
+    }
 }