/*
* The MIT License
*
* Copyright (c) 2010, InfraDNA, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package hudson.util;
import hudson.PluginManager.UberClassLoader;
import jenkins.model.Jenkins;
import org.kohsuke.asm3.ClassWriter;
import org.kohsuke.asm3.MethodVisitor;
import org.kohsuke.asm3.Type;
import java.lang.reflect.Constructor;
import static org.kohsuke.asm3.Opcodes.*;
/**
* Generates a new class that just defines constructors into the super types.
*
* @author Kohsuke Kawaguchi
*/
public class SubClassGenerator extends ClassLoader {
public SubClassGenerator(ClassLoader parent) {
super(parent);
}
public <T> Class<? extends T> generate(Class<T> base, String name) {
ClassWriter cw = new ClassWriter(0);//?
cw.visit(49, ACC_PUBLIC, name.replace('.', '/'), null,
Type.getInternalName(base),null);
for (Constructor c : base.getDeclaredConstructors()) {
Class[] et = c.getExceptionTypes();
String[] exceptions = new String[et.length];
for (int i = 0; i < et.length; i++)
exceptions[i] = Type.getInternalName(et[i]);
String methodDescriptor = getMethodDescriptor(c);
MethodVisitor m = cw.visitMethod(c.getModifiers(), "<init>", methodDescriptor, null, exceptions);
m.visitCode();
int index=1;
m.visitVarInsn(ALOAD,0);
for (Class param : c.getParameterTypes()) {
Type t = Type.getType(param);
m.visitVarInsn(t.getOpcode(ILOAD), index);
index += t.getSize();
}
m.visitMethodInsn(INVOKESPECIAL, Type.getInternalName(base), "<init>", methodDescriptor);
m.visitInsn(RETURN);
m.visitMaxs(index,index);
m.visitEnd();
}
cw.visitEnd();
byte[] image = cw.toByteArray();
Class<? extends T> c = defineClass(name, image, 0, image.length).asSubclass(base);
Jenkins h = Jenkins.getInstance();
if (h!=null) // null only during tests.
((UberClassLoader)h.pluginManager.uberClassLoader).addNamedClass(name,c); // can't change the field type as it breaks binary compatibility
return c;
}
private String getMethodDescriptor(Constructor c) {
StringBuilder buf = new StringBuilder();
buf.append('(');
for (Class p : c.getParameterTypes())
buf.append(Type.getDescriptor(p));
buf.append(")V");
return buf.toString();
}
}