/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.commons.weaver.privilizer;
import java.util.Map;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.commons.Method;
import org.objectweb.asm.tree.ClassNode;
/**
* For any privileged method called from another privileged method (actually the internal implementation method copied
* from the original method body) the call is replaced by a call to the target's internal implementation method, thus
* avoiding nested privileged invocations when possible. Persists everything to a tree model until the parent is
* complete; allowing us to use a tree model while yet building the high-level view as a stack of visitors.
*/
class InlineNestedPrivilegedCalls extends ClassNode {
private final Privilizer privilizer;
private final ClassVisitor next;
/**
* Map of original method to name of internal implementation method.
*/
private final Map<Method, String> privilegedMethods;
/**
* Create a new {@link InlineNestedPrivilegedCalls} object.
* @param privilizer owner
* @param privilegedMethods map of original method to name of internal implementation method
* @param next visitor
*/
InlineNestedPrivilegedCalls(final Privilizer privilizer, final Map<Method, String> privilegedMethods,
final ClassVisitor next) {
super(Opcodes.ASM4);
this.privilizer = privilizer;
this.privilegedMethods = privilegedMethods;
this.next = next;
}
@Override
public void visitEnd() {
super.visitEnd();
accept(new ClassVisitor(Opcodes.ASM4, next) {
@Override
public MethodVisitor visitMethod(final int access, final String name, final String desc,
final String signature, final String[] exceptions) {
final Method outer = new Method(name, desc);
final MethodVisitor orig = super.visitMethod(access, name, desc, signature, exceptions);
if (!privilegedMethods.containsValue(name)) {
return orig;
}
return new MethodVisitor(Opcodes.ASM4, orig) {
@Override
public void visitMethodInsn(final int opcode, final String owner, final String name,
final String desc) {
String useName = name;
if (owner.equals(InlineNestedPrivilegedCalls.this.name)) {
final Method methd = new Method(name, desc);
if (privilegedMethods.containsKey(methd)) {
useName = privilegedMethods.get(methd);
privilizer.env.debug("Inlining call from %s to %s as %s", outer, methd,
useName);
}
}
super.visitMethodInsn(opcode, owner, useName, desc);
}
};
}
});
}
}