From 65bf3316cf384588453604be6b4f0ed3751a8b0f Mon Sep 17 00:00:00 2001 From: tromey Date: Tue, 9 Jan 2007 19:58:05 +0000 Subject: Merged gcj-eclipse branch to trunk. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@120621 138bc75d-0d04-0410-961f-82ee72b054a4 --- libjava/gnu/classpath/VMStackWalker.java | 138 +++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 libjava/gnu/classpath/VMStackWalker.java (limited to 'libjava/gnu/classpath/VMStackWalker.java') diff --git a/libjava/gnu/classpath/VMStackWalker.java b/libjava/gnu/classpath/VMStackWalker.java new file mode 100644 index 00000000000..0cf6ecdba6d --- /dev/null +++ b/libjava/gnu/classpath/VMStackWalker.java @@ -0,0 +1,138 @@ +/* VMStackWalker.java -- Reference implementation of VM hooks for stack access + Copyright (C) 2005, 2006 Free Software Foundation + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package gnu.classpath; + +import gnu.gcj.RawData; + +/** + * This class provides access to the classes on the Java stack + * for reflection and security purposes. + * + *

+ * This class is only available to privileged code (i.e., code loaded + * by the bootstrap loader). + * + * @author John Keiser + * @author Eric Blake + * @author Archie Cobbs + * @author Andrew Haley + * @author Gary Benson + */ +public final class VMStackWalker +{ + /** + * Get a list of all the classes currently executing methods on the + * Java stack. getClassContext()[0] is the class associated + * with the currently executing method, i.e., the method that called + * VMStackWalker.getClassContext() (possibly through + * reflection). So you may need to pop off these stack frames from + * the top of the stack: + *

+ * + * @return an array of the declaring classes of each stack frame + */ + public static native Class[] getClassContext(); + + /** + * Get the class associated with the method invoking the method + * invoking this method, or null if the stack is not + * that deep (e.g., invoked via JNI invocation API). This method + * is an optimization for the expression getClassContext()[1] + * and should return the same result. + * + *

+ * When compiling to native code gcj translates calls to this + * method into calls to getCallingClass(addr), with + * addr being the address of the method calling this + * method. getCallingClass(addr) does not unwind the + * stack, so is therefore more efficient. + */ + public static native Class getCallingClass(); + + /** + * Get the class associated with the method invoking the method + * invoking this method, or null if the stack is not + * that deep (e.g., invoked via JNI invocation API). + * + * @param addr The address of the method invoking this method. + */ + private static native Class getCallingClass(RawData addr); + + /** + * Get the class loader associated with the Class returned by + * getCallingClass(), or null if no such class + * exists or it is the boot loader. This method is an optimization for the + * expression VMStackWalker.getClassLoader(getClassContext()[1]) + * and should return the same result. + * + *

+ * When compiling to native code gcj translates calls to this + * method into calls to getCallingClassLoader(addr), + * with addr being the address of the method calling + * this method. getCallingClassLoader(addr) does not + * unwind the stack, so is therefore more efficient. + */ + public static native ClassLoader getCallingClassLoader(); + + /** + * Get the class loader associated with the Class returned by + * getCallingClass(), or null if no + * such class exists or it is the boot loader. + * + * @param addr The address of the method invoking this method. + */ + private static native ClassLoader getCallingClassLoader(RawData addr); + + /** + * Retrieve the class's ClassLoader, or null if loaded + * by the bootstrap loader. I.e., this should return the same thing + * as {@link java.lang.VMClass#getClassLoader}. This duplicate version + * is here to work around access permissions. + */ + public static native ClassLoader getClassLoader(Class cl); + + /** + * Walk up the stack and return the first non-null class loader. + * If there aren't any non-null class loaders on the stack, return null. + */ + public static native ClassLoader firstNonNullClassLoader(); +} + -- cgit v1.2.3