--- a/jdk/src/share/classes/sun/dyn/util/VerifyAccess.java Thu Mar 31 19:09:02 2011 -0700
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,213 +0,0 @@
-/*
- * Copyright (c) 2008, 2010, 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. Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * 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.
- */
-
-package sun.dyn.util;
-
-import java.lang.reflect.Modifier;
-import sun.dyn.MemberName;
-import sun.dyn.MethodHandleImpl;
-import sun.dyn.empty.Empty;
-import static java.lang.reflect.Modifier.*;
-
-/**
- * This class centralizes information about the JVM's linkage access control.
- * @author jrose
- */
-public class VerifyAccess {
-
- private VerifyAccess() { } // cannot instantiate
-
- private static final int PACKAGE_ONLY = 0;
- private static final int ALL_ACCESS_MODES = (PUBLIC|PRIVATE|PROTECTED|PACKAGE_ONLY);
- private static final boolean ALLOW_NESTMATE_ACCESS = false;
-
- /**
- * Evaluate the JVM linkage rules for access to the given method
- * on behalf of a caller class which proposes to perform the access.
- * Return true if the caller class has privileges to invoke a method
- * or access a field with the given properties.
- * This requires an accessibility check of the referencing class,
- * plus an accessibility check of the member within the class,
- * which depends on the member's modifier flags.
- * <p>
- * The relevant properties include the defining class ({@code defc})
- * of the member, and its modifier flags ({@code mods}).
- * Also relevant is the class used to make the initial symbolic reference
- * to the member ({@code refc}). If this latter class is not distinguished,
- * the defining class should be passed for both arguments ({@code defc == refc}).
- * <h3>JVM Specification, 5.4.4 "Access Control"</h3>
- * A field or method R is accessible to a class or interface D if
- * and only if any of the following conditions is true:<ul>
- * <li>R is public.
- * <li>R is protected and is declared in a class C, and D is either
- * a subclass of C or C itself. Furthermore, if R is not
- * static, then the symbolic reference to R must contain a
- * symbolic reference to a class T, such that T is either a
- * subclass of D, a superclass of D or D itself.
- * <li>R is either protected or has default access (that is,
- * neither public nor protected nor private), and is declared
- * by a class in the same runtime package as D.
- * <li>R is private and is declared in D.
- * </ul>
- * This discussion of access control omits a related restriction
- * on the target of a protected field access or method invocation
- * (the target must be of class D or a subtype of D). That
- * requirement is checked as part of the verification process
- * (5.4.1); it is not part of link-time access control.
- * @param refc the class used in the symbolic reference to the proposed member
- * @param defc the class in which the proposed member is actually defined
- * @param mods modifier flags for the proposed member
- * @param lookupClass the class for which the access check is being made
- * @return true iff the the accessing class can access such a member
- */
- public static boolean isMemberAccessible(Class<?> refc, // symbolic ref class
- Class<?> defc, // actual def class
- int mods, // actual member mods
- Class<?> lookupClass) {
- // Usually refc and defc are the same, but if they differ, verify them both.
- if (refc != defc) {
- if (!isClassAccessible(refc, lookupClass)) {
- // Note that defc is verified in the switch below.
- return false;
- }
- if ((mods & (ALL_ACCESS_MODES|STATIC)) == (PROTECTED|STATIC)) {
- // Apply the special rules for refc here.
- if (!isRelatedClass(refc, lookupClass))
- return isSamePackage(defc, lookupClass);
- // If refc == defc, the call to isPublicSuperClass will do
- // the whole job, since in that case refc (as defc) will be
- // a superclass of the lookup class.
- }
- }
- if (defc == lookupClass)
- return true; // easy check; all self-access is OK
- switch (mods & ALL_ACCESS_MODES) {
- case PUBLIC:
- if (refc != defc) return true; // already checked above
- return isClassAccessible(refc, lookupClass);
- case PROTECTED:
- return isSamePackage(defc, lookupClass) || isPublicSuperClass(defc, lookupClass);
- case PACKAGE_ONLY:
- return isSamePackage(defc, lookupClass);
- case PRIVATE:
- // Loosened rules for privates follows access rules for inner classes.
- return (ALLOW_NESTMATE_ACCESS &&
- isSamePackageMember(defc, lookupClass));
- default:
- throw new IllegalArgumentException("bad modifiers: "+Modifier.toString(mods));
- }
- }
-
- static boolean isRelatedClass(Class<?> refc, Class<?> lookupClass) {
- return (refc == lookupClass ||
- refc.isAssignableFrom(lookupClass) ||
- lookupClass.isAssignableFrom(refc));
- }
-
- static boolean isPublicSuperClass(Class<?> defc, Class<?> lookupClass) {
- return isPublic(defc.getModifiers()) && defc.isAssignableFrom(lookupClass);
- }
-
- /**
- * Evaluate the JVM linkage rules for access to the given class on behalf of caller.
- * <h3>JVM Specification, 5.4.4 "Access Control"</h3>
- * A class or interface C is accessible to a class or interface D
- * if and only if either of the following conditions are true:<ul>
- * <li>C is public.
- * <li>C and D are members of the same runtime package.
- * </ul>
- * @param refc the symbolic reference class to which access is being checked (C)
- * @param lookupClass the class performing the lookup (D)
- */
- public static boolean isClassAccessible(Class<?> refc, Class<?> lookupClass) {
- int mods = refc.getModifiers();
- if (isPublic(mods))
- return true;
- if (isSamePackage(lookupClass, refc))
- return true;
- return false;
- }
-
- /**
- * Test if two classes have the same class loader and package qualifier.
- * @param class1
- * @param class2
- * @return whether they are in the same package
- */
- public static boolean isSamePackage(Class<?> class1, Class<?> class2) {
- if (class1 == class2)
- return true;
- if (!loadersAreRelated(class1.getClassLoader(), class2.getClassLoader()))
- return false;
- String name1 = class1.getName(), name2 = class2.getName();
- int dot = name1.lastIndexOf('.');
- if (dot != name2.lastIndexOf('.'))
- return false;
- for (int i = 0; i < dot; i++) {
- if (name1.charAt(i) != name2.charAt(i))
- return false;
- }
- return true;
- }
-
- /**
- * Test if two classes are defined as part of the same package member (top-level class).
- * If this is true, they can share private access with each other.
- * @param class1
- * @param class2
- * @return whether they are identical or nested together
- */
- public static boolean isSamePackageMember(Class<?> class1, Class<?> class2) {
- if (class1 == class2)
- return true;
- if (!isSamePackage(class1, class2))
- return false;
- if (getOutermostEnclosingClass(class1) != getOutermostEnclosingClass(class2))
- return false;
- return true;
- }
-
- private static Class<?> getOutermostEnclosingClass(Class<?> c) {
- Class<?> pkgmem = c;
- for (Class<?> enc = c; (enc = enc.getEnclosingClass()) != null; )
- pkgmem = enc;
- return pkgmem;
- }
-
- private static boolean loadersAreRelated(ClassLoader loader1, ClassLoader loader2) {
- if (loader1 == loader2 || loader1 == null || loader2 == null) {
- return true;
- }
- for (ClassLoader scan1 = loader1;
- scan1 != null; scan1 = scan1.getParent()) {
- if (scan1 == loader2) return true;
- }
- for (ClassLoader scan2 = loader2;
- scan2 != null; scan2 = scan2.getParent()) {
- if (scan2 == loader1) return true;
- }
- return false;
- }
-}