8267555: Fix class file version during redefinition after 8238048

Reviewed-by: coleenp, sspitsyn

src/hotspot/share/oops/constantPool.cpp

@@ -73,7 +73,6 @@ void ConstantPool::copy_fields(const ConstantPool* orig) {
     set_has_dynamic_constant();
   }
 
-  // Copy class version
   set_major_version(orig->major_version());
   set_minor_version(orig->minor_version());
 

src/hotspot/share/prims/jvmtiRedefineClasses.cpp

@@ -1852,9 +1852,12 @@ jvmtiError VM_RedefineClasses::merge_cp_and_rewrite(
     return JVMTI_ERROR_INTERNAL;
   }
 
-  // Save fields from the old_cp.
-  merge_cp->copy_fields(old_cp());
-  scratch_cp->copy_fields(old_cp());
+  // Set dynamic constants attribute from the original CP.
+  if (old_cp->has_dynamic_constant()) {
+    scratch_cp->set_has_dynamic_constant();
+  }
+  // Copy attributes from scratch_cp to merge_cp
+  merge_cp->copy_fields(scratch_cp());
 
   log_info(redefine, class, constantpool)("merge_cp_len=%d, index_map_len=%d", merge_cp_length, _index_map_count);
 
@@ -4396,6 +4399,16 @@ void VM_RedefineClasses::redefine_single_class(Thread* current, jclass the_jclas
 
   swap_annotations(the_class, scratch_class);
 
+  // Replace minor version number of class file
+  u2 old_minor_version = the_class->constants()->minor_version();
+  the_class->constants()->set_minor_version(scratch_class->constants()->minor_version());
+  scratch_class->constants()->set_minor_version(old_minor_version);
+
+  // Replace major version number of class file
+  u2 old_major_version = the_class->constants()->major_version();
+  the_class->constants()->set_major_version(scratch_class->constants()->major_version());
+  scratch_class->constants()->set_major_version(old_major_version);
+
   // Replace CP indexes for class and name+type of enclosing method
   u2 old_class_idx  = the_class->enclosing_method_class_index();
   u2 old_method_idx = the_class->enclosing_method_method_index();

test/hotspot/jtreg/serviceability/jvmti/RedefineClasses/ClassVersionAfterRedefine.java

@@ -0,0 +1,102 @@
+/*
+ * Copyright Amazon.com Inc. 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 8267555
+ * @requires vm.jvmti
+ * @summary Class redefinition with a different class file version
+ * @library /test/lib
+ * @compile TestClassOld.jasm TestClassNew.jasm
+ * @run main RedefineClassHelper
+ * @run main/othervm -javaagent:redefineagent.jar ClassVersionAfterRedefine
+ */
+
+import java.io.InputStream;
+import java.lang.reflect.Method;
+
+import static jdk.test.lib.Asserts.assertTrue;
+
+public class ClassVersionAfterRedefine extends ClassLoader {
+
+    private static String myName = ClassVersionAfterRedefine.class.getName();
+
+    private static byte[] getBytecodes(String name) throws Exception {
+        InputStream is = ClassVersionAfterRedefine.class.getResourceAsStream(name + ".class");
+        byte[] buf = is.readAllBytes();
+        System.out.println("sizeof(" + name + ".class) == " + buf.length);
+        return buf;
+    }
+
+    private static int getStringIndex(String needle, byte[] buf) {
+        return getStringIndex(needle, buf, 0);
+    }
+
+    private static int getStringIndex(String needle, byte[] buf, int offset) {
+        outer:
+        for (int i = offset; i < buf.length - offset - needle.length(); i++) {
+            for (int j = 0; j < needle.length(); j++) {
+                if (buf[i + j] != (byte)needle.charAt(j)) continue outer;
+            }
+            return i;
+        }
+        return 0;
+    }
+
+    private static void replaceString(byte[] buf, String name, int index) {
+        for (int i = index; i < index + name.length(); i++) {
+            buf[i] = (byte)name.charAt(i - index);
+        }
+    }
+
+    private static void replaceAllStrings(byte[] buf, String oldString, String newString) throws Exception {
+        assertTrue(oldString.length() == newString.length(), "must have same length");
+        int index = -1;
+        while ((index = getStringIndex(oldString, buf, index + 1)) != 0) {
+            replaceString(buf, newString, index);
+        }
+    }
+
+    public static void main(String[] s) throws Exception {
+
+        byte[] buf = getBytecodes("TestClassOld");
+        // Poor man's renaming of class "TestClassOld" to "TestClassXXX"
+        replaceAllStrings(buf, "TestClassOld", "TestClassXXX");
+        ClassVersionAfterRedefine cvar = new ClassVersionAfterRedefine();
+        Class<?> old = cvar.defineClass(null, buf, 0, buf.length);
+        Method foo = old.getMethod("foo");
+        Object result = foo.invoke(null);
+        assertTrue("java-lang-String".equals(result));
+        System.out.println(old.getSimpleName() + ".foo() = " + result);
+
+        buf = getBytecodes("TestClassNew");
+        // Rename class "TestClassNew" to "TestClassXXX" so we can use it for
+        // redefining the original version of "TestClassXXX" (i.e. "TestClassOld").
+        replaceAllStrings(buf, "TestClassNew", "TestClassXXX");
+        // Now redine the original version of "TestClassXXX" (i.e. "TestClassOld").
+        RedefineClassHelper.redefineClass(old, buf);
+        result = foo.invoke(null);
+        assertTrue("java.lang.String".equals(result));
+        System.out.println(old.getSimpleName() + ".foo() = " + result);
+    }
+}

test/hotspot/jtreg/serviceability/jvmti/RedefineClasses/TestClassNew.jasm

@@ -0,0 +1,45 @@
+/*
+ * Copyright Amazon.com Inc. 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.
+ */
+
+super public final class TestClassNew version 49:0 {
+
+    public Method "<init>":"()V" stack 1 locals 1 {
+        aload_0;
+        invokespecial    Method java/lang/Object."<init>":"()V";
+        return;
+    }
+
+    public static Method foo:"()Ljava/lang/String;" stack 1 locals 1 {
+        ldc            class  java/lang/String;
+        invokevirtual  Method java/lang/Class.getName:"()Ljava/lang/String;";
+        areturn;
+    }
+
+    public static Method main:"([Ljava/lang/String;)V" stack 2 locals 2 {
+        getstatic      Field  java/lang/System.out:"Ljava/io/PrintStream;";
+        invokestatic   Method TestClassNew.foo:"()Ljava/lang/String;";
+        invokevirtual  Method java/io/PrintStream.println:"(Ljava/lang/String;)V";
+        return;
+    }
+
+}

test/hotspot/jtreg/serviceability/jvmti/RedefineClasses/TestClassOld.jasm

@@ -0,0 +1,44 @@
+/*
+ * Copyright Amazon.com Inc. 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.
+ */
+
+super public final class TestClassOld version 48:0 {
+
+    public Method "<init>":"()V" stack 1 locals 1 {
+        aload_0;
+        invokespecial    Method java/lang/Object."<init>":"()V";
+        return;
+    }
+
+    public static Method foo:"()Ljava/lang/String;" stack 1 locals 1 {
+        ldc            String "java-lang-String";
+        areturn;
+    }
+
+    public static Method main:"([Ljava/lang/String;)V" stack 2 locals 2 {
+        getstatic      Field java/lang/System.out:"Ljava/io/PrintStream;";
+        invokestatic   Method TestClassOld.foo:"()Ljava/lang/String;";
+        invokevirtual  Method java/io/PrintStream.println:"(Ljava/lang/String;)V";
+        return;
+    }
+
+}