org.ow2.asm/asm-util/5.2 : org/objectweb/asm/optimizer/ClassOptimizer.java

ClassOptimizer
http://asm.objectweb.org/asm-util/: A very small and fast Java bytecode manipulation framework (ObjectWeb)
Eric Bruneton
Eugene Kuleshov
Remi Forax
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.
/***
 * 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 ClassVisitor that renames fields and methods, and removes debug info. 
Author: Eric Bruneton, Eugene Kuleshov/**
 * 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<String> syntheticClassFields = new ArrayList<String>();

    public ClassOptimizer(final ClassVisitor cv, final Remapper remapper) {
        super(Opcodes.ASM5, 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("<clinit>") && !isInterface) {
            hasClinitMethod = true;
            MethodVisitor mv = super.visitMethod(access, name, desc, null,
                    exceptions);
            return new MethodVisitor(Opcodes.ASM5, 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", "<init>",
                    "(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, "<clinit>", "()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();
    }
}
/

org.ow2.asm/ asm-util/ 5.2/ org/objectweb/asm/optimizer/ClassOptimizer.java
