changeset 47709:bc112140e089

8186092: Unnecessary loader constraints produced when there are multiple defaults Summary: Do not check loader constraints for overpass methods Reviewed-by: dholmes, acorn
author hseigel
date Thu, 28 Sep 2017 13:01:24 -0400
parents 8a3599d60996
children 9dfb5791d130
files src/hotspot/share/classfile/defaultMethods.cpp src/hotspot/share/oops/klassVtable.cpp test/hotspot/jtreg/runtime/LoaderConstraints/common/C.jasm test/hotspot/jtreg/runtime/LoaderConstraints/common/Foo.java test/hotspot/jtreg/runtime/LoaderConstraints/common/J.java test/hotspot/jtreg/runtime/LoaderConstraints/common/PreemptingClassLoader.java test/hotspot/jtreg/runtime/LoaderConstraints/itableICCE/I.java test/hotspot/jtreg/runtime/LoaderConstraints/itableICCE/Task.java test/hotspot/jtreg/runtime/LoaderConstraints/itableICCE/Test.java test/hotspot/jtreg/runtime/LoaderConstraints/itableLdrConstraint/I.java test/hotspot/jtreg/runtime/LoaderConstraints/itableLdrConstraint/Task.java test/hotspot/jtreg/runtime/LoaderConstraints/itableLdrConstraint/Test.java test/hotspot/jtreg/runtime/LoaderConstraints/vtableAME/I.java test/hotspot/jtreg/runtime/LoaderConstraints/vtableAME/Task.java test/hotspot/jtreg/runtime/LoaderConstraints/vtableAME/Test.java test/hotspot/jtreg/runtime/LoaderConstraints/vtableLdrConstraint/I.java test/hotspot/jtreg/runtime/LoaderConstraints/vtableLdrConstraint/Task.java test/hotspot/jtreg/runtime/LoaderConstraints/vtableLdrConstraint/Test.java
diffstat 18 files changed, 666 insertions(+), 43 deletions(-) [+]
line wrap: on
line diff
--- a/src/hotspot/share/classfile/defaultMethods.cpp	Tue Sep 26 14:05:27 2017 +0200
+++ b/src/hotspot/share/classfile/defaultMethods.cpp	Thu Sep 28 13:01:24 2017 -0400
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 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
@@ -767,15 +767,14 @@
 // This is the guts of the default methods implementation.  This is called just
 // after the classfile has been parsed if some ancestor has default methods.
 //
-// First if finds any name/signature slots that need any implementation (either
+// First it finds any name/signature slots that need any implementation (either
 // because they are miranda or a superclass's implementation is an overpass
 // itself).  For each slot, iterate over the hierarchy, to see if they contain a
 // signature that matches the slot we are looking at.
 //
-// For each slot filled, we generate an overpass method that either calls the
-// unique default method candidate using invokespecial, or throws an exception
-// (in the case of no default method candidates, or more than one valid
-// candidate).  These methods are then added to the class's method list.
+// For each slot filled, we either record the default method candidate in the
+// klass default_methods list or, only to handle exception cases, we create an
+// overpass method that throws an exception and add it to the klass methods list.
 // The JVM does not create bridges nor handle generic signatures here.
 void DefaultMethods::generate_default_methods(
     InstanceKlass* klass, const GrowableArray<Method*>* mirandas, TRAPS) {
@@ -901,6 +900,11 @@
 // This allows virtual methods to override the overpass, but ensures
 // that a local method search will find the exception rather than an abstract
 // or default method that is not a valid candidate.
+//
+// Note that if overpass method are ever created that are not exception
+// throwing methods then the loader constraint checking logic for vtable and
+// itable creation needs to be changed to check loader constraints for the
+// overpass methods that do not throw exceptions.
 static void create_defaults_and_exceptions(
     GrowableArray<EmptyVtableSlot*>* slots,
     InstanceKlass* klass, TRAPS) {
--- a/src/hotspot/share/oops/klassVtable.cpp	Tue Sep 26 14:05:27 2017 +0200
+++ b/src/hotspot/share/oops/klassVtable.cpp	Thu Sep 28 13:01:24 2017 -0400
@@ -479,13 +479,15 @@
           allocate_new = false;
         }
 
-        if (checkconstraints) {
-        // Override vtable entry if passes loader constraint check
-        // if loader constraint checking requested
-        // No need to visit his super, since he and his super
-        // have already made any needed loader constraints.
-        // Since loader constraints are transitive, it is enough
-        // to link to the first super, and we get all the others.
+        // Do not check loader constraints for overpass methods because overpass
+        // methods are created by the jvm to throw exceptions.
+        if (checkconstraints && !target_method()->is_overpass()) {
+          // Override vtable entry if passes loader constraint check
+          // if loader constraint checking requested
+          // No need to visit his super, since he and his super
+          // have already made any needed loader constraints.
+          // Since loader constraints are transitive, it is enough
+          // to link to the first super, and we get all the others.
           Handle super_loader(THREAD, super_klass->class_loader());
 
           if (target_loader() != super_loader()) {
@@ -495,21 +497,23 @@
                                                         super_loader, true,
                                                         CHECK_(false));
             if (failed_type_symbol != NULL) {
-              const char* msg = "loader constraint violation: when resolving "
-                "overridden method \"%s\" the class loader (instance"
-                " of %s) of the current class, %s, and its superclass loader "
-                "(instance of %s), have different Class objects for the type "
-                "%s used in the signature";
+              const char* msg = "loader constraint violation for class %s: when selecting "
+                "overriding method \"%s\" the class loader (instance of %s) of the "
+                "selected method's type %s, and the class loader (instance of %s) for its super "
+                "type %s have different Class objects for the type %s used in the signature";
+              char* curr_class = klass->name()->as_C_string();
               char* sig = target_method()->name_and_sig_as_C_string();
               const char* loader1 = SystemDictionary::loader_name(target_loader());
-              char* current = target_klass->name()->as_C_string();
+              char* sel_class = target_klass->name()->as_C_string();
               const char* loader2 = SystemDictionary::loader_name(super_loader());
+              char* super_class = super_klass->name()->as_C_string();
               char* failed_type_name = failed_type_symbol->as_C_string();
-              size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) +
-                strlen(current) + strlen(loader2) + strlen(failed_type_name);
+              size_t buflen = strlen(msg) + strlen(curr_class) + strlen(sig) +
+                strlen(loader1) + strlen(sel_class) + strlen(loader2) +
+                strlen(super_class) + strlen(failed_type_name);
               char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
-              jio_snprintf(buf, buflen, msg, sig, loader1, current, loader2,
-                           failed_type_name);
+              jio_snprintf(buf, buflen, msg, curr_class, sig, loader1, sel_class, loader2,
+                           super_class, failed_type_name);
               THROW_MSG_(vmSymbols::java_lang_LinkageError(), buf, false);
             }
           }
@@ -1193,13 +1197,15 @@
       // to correctly enforce loader constraints for interface method inheritance
       target = LinkResolver::lookup_instance_method_in_klasses(_klass, m->name(), m->signature(), CHECK);
     }
-    if (target == NULL || !target->is_public() || target->is_abstract()) {
-      // Entry does not resolve. Leave it empty for AbstractMethodError.
-        if (!(target == NULL) && !target->is_public()) {
-          // Stuff an IllegalAccessError throwing method in there instead.
-          itableOffsetEntry::method_entry(_klass, method_table_offset)[m->itable_index()].
-              initialize(Universe::throw_illegal_access_error());
-        }
+    if (target == NULL || !target->is_public() || target->is_abstract() || target->is_overpass()) {
+      assert(target == NULL || !target->is_overpass() || target->is_public(),
+             "Non-public overpass method!");
+      // Entry does not resolve. Leave it empty for AbstractMethodError or other error.
+      if (!(target == NULL) && !target->is_public()) {
+        // Stuff an IllegalAccessError throwing method in there instead.
+        itableOffsetEntry::method_entry(_klass, method_table_offset)[m->itable_index()].
+            initialize(Universe::throw_illegal_access_error());
+      }
     } else {
       // Entry did resolve, check loader constraints before initializing
       // if checkconstraints requested
@@ -1213,24 +1219,24 @@
                                                       interface_loader,
                                                       true, CHECK);
           if (failed_type_symbol != NULL) {
-            const char* msg = "loader constraint violation in interface "
-              "itable initialization: when resolving method \"%s\" the class"
-              " loader (instance of %s) of the current class, %s, "
-              "and the class loader (instance of %s) for interface "
-              "%s have different Class objects for the type %s "
-              "used in the signature";
-            char* sig = target()->name_and_sig_as_C_string();
-            const char* loader1 = SystemDictionary::loader_name(method_holder_loader());
+            const char* msg = "loader constraint violation in interface itable"
+              " initialization for class %s: when selecting method \"%s\" the"
+              " class loader (instance of %s) for super interface %s, and the class"
+              " loader (instance of %s) of the selected method's type, %s have"
+              " different Class objects for the type %s used in the signature";
             char* current = _klass->name()->as_C_string();
-            const char* loader2 = SystemDictionary::loader_name(interface_loader());
+            char* sig = m->name_and_sig_as_C_string();
+            const char* loader1 = SystemDictionary::loader_name(interface_loader());
             char* iface = InstanceKlass::cast(interf)->name()->as_C_string();
+            const char* loader2 = SystemDictionary::loader_name(method_holder_loader());
+            char* mclass = target()->method_holder()->name()->as_C_string();
             char* failed_type_name = failed_type_symbol->as_C_string();
-            size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) +
-              strlen(current) + strlen(loader2) + strlen(iface) +
+            size_t buflen = strlen(msg) + strlen(current) + strlen(sig) +
+              strlen(loader1) + strlen(iface) + strlen(loader2) + strlen(mclass) +
               strlen(failed_type_name);
             char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
-            jio_snprintf(buf, buflen, msg, sig, loader1, current, loader2,
-                         iface, failed_type_name);
+            jio_snprintf(buf, buflen, msg, current, sig, loader1, iface,
+                         loader2, mclass, failed_type_name);
             THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
           }
         }
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/common/C.jasm	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,37 @@
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+// If this file was written in java then some of the tests would fail during
+// compilation with errors such as:
+//   class C inherits unrelated defaults for m() from types I and J
+//   C is not abstract and does not override abstract method m() in I
+
+super public class C implements I, J version 52:0 {
+
+    public Method "<init>":"()V" stack 1 locals 1 {
+        aload_0;
+        invokespecial    Method java/lang/Object."<init>":"()V";
+        return;
+    }
+
+} // end Class C
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/common/Foo.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,24 @@
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+public class Foo {}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/common/J.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,26 @@
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+public interface J {
+    public default Foo m() { return null; }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/common/PreemptingClassLoader.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,59 @@
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+import java.util.*;
+import java.io.*;
+
+public class PreemptingClassLoader extends ClassLoader {
+
+    private final Set<String> names = new HashSet<>();
+
+    public PreemptingClassLoader(String... names) {
+        for (String n : names) this.names.add(n);
+    }
+
+    protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
+        if (!names.contains(name)) return super.loadClass(name, resolve);
+        Class<?> result = findLoadedClass(name);
+        if (result == null) {
+            String filename = name.replace('.', '/') + ".class";
+            try (InputStream data = getResourceAsStream(filename)) {
+                if (data == null) throw new ClassNotFoundException();
+                try (ByteArrayOutputStream buffer = new ByteArrayOutputStream()) {
+                    int b;
+                    do {
+                        b = data.read();
+                        if (b >= 0) buffer.write(b);
+                    } while (b >= 0);
+                    byte[] bytes = buffer.toByteArray();
+                    result = defineClass(name, bytes, 0, bytes.length);
+                }
+            } catch (IOException e) {
+                throw new ClassNotFoundException("Error reading class file", e);
+            }
+        }
+        if (resolve) resolveClass(result);
+        return result;
+    }
+
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/itableICCE/I.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,26 @@
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+public interface I {
+    public default Foo m() { return null; }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/itableICCE/Task.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,31 @@
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+public class Task implements Runnable {
+
+    public void run() {
+        Class<?> c = Foo.class; // forces PreemptingClassLoader to load Foo
+        C x = new C(); // should not trigger loader constraints exception
+        x.m();
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/itableICCE/Test.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,59 @@
+/*
+ * 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.
+ *
+ * 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
+ * @bug 8186092
+ * @compile ../common/Foo.java
+ *          I.java
+ *          ../common/J.java
+ *          ../common/C.jasm
+ *          Task.java
+ *          ../common/PreemptingClassLoader.java
+ * @run main/othervm Test
+ */
+
+public class Test {
+
+    // Test that LinkageError exceptions are not thrown during itable creation,
+    // for loader constraint errors, if the target method is an overpass method.
+    //
+    // In this test, during itable creation for class C, method "m()LFoo;" for
+    // C's super interface I has a different class Foo than the selected method's
+    // type J.  But, the selected method is an overpass method (that throws an
+    // ICCE). So, no LinkageError exception should be thrown because the loader
+    // constraint check that would cause the LinkageError should not be done.
+    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", "C", "I");
+        Runnable r = (Runnable) l.loadClass("Task").newInstance();
+        try {
+            r.run(); // Cause an ICCE because both I and J define m()LFoo;
+            throw new RuntimeException("Expected ICCE exception not thrown");
+        } catch (IncompatibleClassChangeError e) {
+            if (!e.getMessage().contains("Conflicting default methods: I.m J.m")) {
+                throw new RuntimeException("Wrong ICCE exception thrown: " + e.getMessage());
+            }
+        }
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/itableLdrConstraint/I.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,26 @@
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+public interface I {
+    public Foo m();
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/itableLdrConstraint/Task.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,31 @@
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+public class Task implements Runnable {
+
+    public void run() {
+        Class<?> c = Foo.class; // forces PreemptingClassLoader to load Foo
+        C x = new C(); // triggers overloading constraints
+        x.m();
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/itableLdrConstraint/Test.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,60 @@
+/*
+ * 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.
+ *
+ * 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
+ * @bug 8186092
+ * @compile ../common/Foo.java
+ *          ../common/J.java
+ *          I.java
+ *          ../common/C.jasm
+ *          Task.java
+ *          ../common/PreemptingClassLoader.java
+ * @run main/othervm Test
+ */
+
+public class Test {
+
+    // Test that the error message is correct when a loader constraint error is
+    // detected during itable creation.
+    //
+    // In this test, during itable creation for class C, method "m()LFoo;" for
+    // C's super interface I has a different class Foo than the selected method's
+    // type super interface J.  The selected method is not an overpass method nor
+    // otherwise excluded from loader constraint checking.  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", "C", "I");
+        Runnable r = (Runnable) l.loadClass("Task").newInstance();
+        try {
+            r.run();
+            throw new RuntimeException("Expected LinkageError exception not thrown");
+        } catch (LinkageError e) {
+            if (!e.getMessage().contains(
+                "loader constraint violation in interface itable initialization for class C:")) {
+                throw new RuntimeException("Wrong LinkageError exception thrown: " + e.getMessage());
+            }
+        }
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/vtableAME/I.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,26 @@
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+public interface I extends J {
+    public Foo m();
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/vtableAME/Task.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,24 @@
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+public class Task extends C { }
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/vtableAME/Test.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,66 @@
+/*
+ * 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.
+ *
+ * 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
+ * @bug 8186092
+ * @compile ../common/Foo.java
+ *          ../common/J.java
+ *          I.java
+ *          ../common/C.jasm
+ *          Task.java
+ *          ../common/PreemptingClassLoader.java
+ * @run main/othervm Test
+ */
+
+import java.io.PrintStream;
+import java.lang.reflect.*;
+
+public class Test {
+
+    // Test that LinkageError exceptions are not thrown during vtable creation,
+    // for loader constraint errors, if the target method is an overpass method.
+    //
+    // In this test, during vtable creation for class Task, the target method
+    // "Task.m()LFoo;" is an overpass method (that throws an AME).  So, even
+    // though it is inheriting the method from its super class C, and Task has
+    // a different class Foo than C, no LinkageError exception should be thrown
+    // because the loader constraint check that would cause the LinkageError
+    // should not be done.
+    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", "J");
+        l.loadClass("Foo");
+        l.loadClass("Task").newInstance();
+        Task t = new Task();
+        try {
+            t.m(); // Should get AME
+            throw new RuntimeException("Missing AbstractMethodError exception");
+        } catch (AbstractMethodError e) {
+            if (!e.getMessage().contains("Method Task.m()LFoo; is abstract")) {
+                throw new RuntimeException("Wrong AME exception thrown: " + e.getMessage());
+            }
+        }
+    }
+
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/vtableLdrConstraint/I.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,25 @@
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+public interface I extends J {
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/vtableLdrConstraint/Task.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,30 @@
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+public class Task extends C {
+
+    public Foo m() {
+        return null;
+    }
+
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/runtime/LoaderConstraints/vtableLdrConstraint/Test.java	Thu Sep 28 13:01:24 2017 -0400
@@ -0,0 +1,63 @@
+/*
+ * 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.
+ *
+ * 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
+ * @bug 8186092
+ * @compile ../common/Foo.java
+ *          ../common/J.java
+ *          I.java
+ *          ../common/C.jasm
+ *          Task.java
+ *          ../common/PreemptingClassLoader.java
+ * @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());
+            }
+        }
+    }
+
+}
+