org.objectweb.asm.optimizer.ClassOptimizer Maven / Gradle / Ivy
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/***
* ASM: a very small and fast Java bytecode manipulation framework
* Copyright (c) 2000-2011 INRIA, France Telecom
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.objectweb.asm.optimizer;
import java.util.ArrayList;
import java.util.List;
import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.Attribute;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.TypePath;
import org.objectweb.asm.commons.Remapper;
import org.objectweb.asm.commons.ClassRemapper;
/**
* A {@link ClassVisitor} that renames fields and methods, and removes debug
* info.
*
* @author Eric Bruneton
* @author Eugene Kuleshov
*/
public class ClassOptimizer extends ClassRemapper {
private String pkgName;
String clsName;
boolean isInterface = false;
boolean hasClinitMethod = false;
List syntheticClassFields = new ArrayList();
public ClassOptimizer(final ClassVisitor cv, final Remapper remapper) {
super(Opcodes.ASM6, cv, remapper);
}
FieldVisitor syntheticFieldVisitor(final int access, final String name,
final String desc) {
return super.visitField(access, name, desc, null, null);
}
// ------------------------------------------------------------------------
// Overridden methods
// ------------------------------------------------------------------------
@Override
public void visit(final int version, final int access, final String name,
final String signature, final String superName,
final String[] interfaces) {
super.visit(Opcodes.V1_2, access, name, null, superName, interfaces);
int index = name.lastIndexOf('/');
if (index > 0) {
pkgName = name.substring(0, index);
} else {
pkgName = "";
}
clsName = name;
isInterface = (access & Opcodes.ACC_INTERFACE) != 0;
}
@Override
public void visitSource(final String source, final String debug) {
// remove debug info
}
@Override
public void visitOuterClass(final String owner, final String name,
final String desc) {
// remove debug info
}
@Override
public AnnotationVisitor visitAnnotation(final String desc,
final boolean visible) {
// remove annotations
return null;
}
@Override
public AnnotationVisitor visitTypeAnnotation(int typeRef,
TypePath typePath, String desc, boolean visible) {
// remove annotations
return null;
}
@Override
public void visitAttribute(final Attribute attr) {
// remove non standard attributes
}
@Override
public void visitInnerClass(final String name, final String outerName,
final String innerName, final int access) {
// remove debug info
}
@Override
public FieldVisitor visitField(final int access, final String name,
final String desc, final String signature, final Object value) {
String s = remapper.mapFieldName(className, name, desc);
if ("-".equals(s)) {
return null;
}
if ((access & (Opcodes.ACC_PUBLIC | Opcodes.ACC_PROTECTED)) == 0) {
if ((access & Opcodes.ACC_FINAL) != 0
&& (access & Opcodes.ACC_STATIC) != 0 && desc.length() == 1) {
return null;
}
if ("org/objectweb/asm".equals(pkgName) && s.equals(name)) {
System.out.println("INFO: " + clsName + "." + s
+ " could be renamed");
}
super.visitField(access, name, desc, null, value);
} else {
if (!s.equals(name)) {
throw new RuntimeException("The public or protected field "
+ className + '.' + name + " must not be renamed.");
}
super.visitField(access, name, desc, null, value);
}
return null; // remove debug info
}
@Override
public MethodVisitor visitMethod(final int access, final String name,
final String desc, final String signature, final String[] exceptions) {
String s = remapper.mapMethodName(className, name, desc);
if ("-".equals(s)) {
return null;
}
if (name.equals("") && !isInterface) {
hasClinitMethod = true;
MethodVisitor mv = super.visitMethod(access, name, desc, null,
exceptions);
return new MethodVisitor(Opcodes.ASM6, mv) {
@Override
public void visitCode() {
super.visitCode();
mv.visitMethodInsn(Opcodes.INVOKESTATIC, clsName,
"_clinit_", "()V", false);
}
};
}
if ((access & (Opcodes.ACC_PUBLIC | Opcodes.ACC_PROTECTED)) == 0) {
if ("org/objectweb/asm".equals(pkgName) && !name.startsWith("<")
&& s.equals(name)) {
System.out.println("INFO: " + clsName + "." + s
+ " could be renamed");
}
return super.visitMethod(access, name, desc, null, exceptions);
} else {
if (!s.equals(name)) {
throw new RuntimeException("The public or protected method "
+ className + '.' + name + desc
+ " must not be renamed.");
}
return super.visitMethod(access, name, desc, null, exceptions);
}
}
@Override
protected MethodVisitor createMethodRemapper(MethodVisitor mv) {
return new MethodOptimizer(this, mv, remapper);
}
@Override
public void visitEnd() {
if (syntheticClassFields.isEmpty()) {
if (hasClinitMethod) {
MethodVisitor mv = cv.visitMethod(Opcodes.ACC_STATIC
| Opcodes.ACC_SYNTHETIC, "_clinit_", "()V", null, null);
mv.visitCode();
mv.visitInsn(Opcodes.RETURN);
mv.visitMaxs(0, 0);
mv.visitEnd();
}
} else {
MethodVisitor mv = cv.visitMethod(Opcodes.ACC_STATIC
| Opcodes.ACC_SYNTHETIC, "class$",
"(Ljava/lang/String;)Ljava/lang/Class;", null, null);
mv.visitCode();
Label l0 = new Label();
Label l1 = new Label();
Label l2 = new Label();
mv.visitTryCatchBlock(l0, l1, l2,
"java/lang/ClassNotFoundException");
mv.visitLabel(l0);
mv.visitVarInsn(Opcodes.ALOAD, 0);
mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/Class",
"forName", "(Ljava/lang/String;)Ljava/lang/Class;", false);
mv.visitLabel(l1);
mv.visitInsn(Opcodes.ARETURN);
mv.visitLabel(l2);
mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL,
"java/lang/ClassNotFoundException", "getMessage",
"()Ljava/lang/String;", false);
mv.visitVarInsn(Opcodes.ASTORE, 1);
mv.visitTypeInsn(Opcodes.NEW, "java/lang/NoClassDefFoundError");
mv.visitInsn(Opcodes.DUP);
mv.visitVarInsn(Opcodes.ALOAD, 1);
mv.visitMethodInsn(Opcodes.INVOKESPECIAL,
"java/lang/NoClassDefFoundError", "",
"(Ljava/lang/String;)V", false);
mv.visitInsn(Opcodes.ATHROW);
mv.visitMaxs(3, 2);
mv.visitEnd();
if (hasClinitMethod) {
mv = cv.visitMethod(Opcodes.ACC_STATIC | Opcodes.ACC_PRIVATE,
"_clinit_", "()V", null, null);
} else {
mv = cv.visitMethod(Opcodes.ACC_STATIC, "", "()V",
null, null);
}
for (String ldcName : syntheticClassFields) {
String fieldName = "class$" + ldcName.replace('/', '$');
mv.visitLdcInsn(ldcName.replace('/', '.'));
mv.visitMethodInsn(Opcodes.INVOKESTATIC, clsName, "class$",
"(Ljava/lang/String;)Ljava/lang/Class;", false);
mv.visitFieldInsn(Opcodes.PUTSTATIC, clsName, fieldName,
"Ljava/lang/Class;");
}
mv.visitInsn(Opcodes.RETURN);
mv.visitMaxs(1, 0);
mv.visitEnd();
}
super.visitEnd();
}
}