/***
 * ASM tests
 * 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;

import java.io.PrintWriter;
import java.lang.instrument.ClassFileTransformer;
import java.lang.instrument.IllegalClassFormatException;
import java.lang.instrument.Instrumentation;
import java.security.ProtectionDomain;
import java.util.Random;

import org.objectweb.asm.util.TraceClassVisitor;

import junit.framework.TestSuite;

/**
 * ClassWriter tests.
 *
 * @author Eric Bruneton
 */
public class ClassWriterComputeFramesDeadCodeTest extends AbstractTest {

    public static void premain(
        final String agentArgs,
        final Instrumentation inst)
    {
        inst.addTransformer(new ClassFileTransformer() {
            public byte[] transform(
                final ClassLoader loader,
                final String className,
                final Class<?> classBeingRedefined,
                final ProtectionDomain domain,
                final byte[] classFileBuffer)
                    throws IllegalClassFormatException
            {
                String n = className.replace('/', '.');
                if (n.indexOf("javax") == -1) {
                    return null;
                }
                if (agentArgs.length() == 0 || n.indexOf(agentArgs) != -1) {
                    return transformClass(n, classFileBuffer);
                } else {
                    return null;
                }
            }
        });
    }

    static byte[] transformClass(final String n, final byte[] clazz) {
        ClassReader cr = new ClassReader(clazz);
        ClassWriter cw = new ComputeClassWriter(ClassWriter.COMPUTE_FRAMES);
        cr.accept(new ClassVisitor(Opcodes.ASM4, cw) {

            private String className;

            @Override
            public void visit(
                final int version,
                final int access,
                final String name,
                final String signature,
                final String superName,
                final String[] interfaces)
            {
                className = name;
                super.visit((version & 0xFFFF) < Opcodes.V1_6 ? Opcodes.V1_6 : version,
                        access,
                        name,
                        signature,
                        superName,
                        interfaces);
            }

            @Override
            public MethodVisitor visitMethod(
                int access,
                String name,
                String desc,
                String signature,
                String[] exceptions)
            {
                int seed = (className + "." + name + desc).hashCode();
                return new MethodDeadCodeInserter(seed, super.visitMethod(access,
                        name,
                        desc,
                        signature,
                        exceptions));
            }

        }, ClassReader.SKIP_FRAMES | ClassReader.SKIP_DEBUG);
        byte[] b = cw.toByteArray();
        if (n.equals("javax.imageio.ImageIO")) new ClassReader(b).accept(new TraceClassVisitor(new PrintWriter(System.err)), 0);

        return b;
    }

    public static TestSuite suite() throws Exception {
        return new ClassWriterComputeFramesDeadCodeTest().getSuite();
    }

    @Override
    public void test() throws Exception {
        try {
            Class.forName(n, true, getClass().getClassLoader());
        } catch (NoClassDefFoundError ncdfe) {
            // ignored
        } catch (UnsatisfiedLinkError ule) {
            // ignored
        } catch (ClassFormatError cfe) {
            fail(cfe.getMessage());
        } catch (VerifyError ve) {
            /*String s = n.replace('.', '/') + ".class";
            InputStream is = getClass().getClassLoader().getResourceAsStream(s);
            ClassReader cr = new ClassReader(is);
            byte[] b = transformClass("", cr.b);
            StringWriter sw1 = new StringWriter();
            StringWriter sw2 = new StringWriter();
            sw2.write(ve.toString() + "\n");
            ClassVisitor cv1 = new TraceClassVisitor(new PrintWriter(sw1));
            ClassVisitor cv2 = new TraceClassVisitor(new PrintWriter(sw2));
            cr.accept(cv1, 0);
            new ClassReader(b).accept(cv2, 0);
            String s1 = sw1.toString();
            String s2 = sw2.toString();
            assertEquals("different data", s1, s2);*/
            fail(ve.getMessage());
        }
    }
}

class MethodDeadCodeInserter extends MethodVisitor implements Opcodes {

    private Random r;

    public MethodDeadCodeInserter(int seed, final MethodVisitor mv) {
        super(ASM4, mv);
        r = new Random(seed);
    }

    @Override
    public void visitInsn(int opcode) {
        super.visitInsn(opcode);
        insertDeadcode();
    }

    @Override
    public void visitIntInsn(int opcode, int operand) {
        super.visitIntInsn(opcode, operand);
        insertDeadcode();
    }

    @Override
    public void visitVarInsn(int opcode, int var) {
        super.visitVarInsn(opcode, var);
        insertDeadcode();
    }

    @Override
    public void visitTypeInsn(int opcode, String type) {
        super.visitTypeInsn(opcode, type);
        insertDeadcode();
    }

    @Override
    public void visitFieldInsn(
        int opcode,
        String owner,
        String name,
        String desc)
    {
        super.visitFieldInsn(opcode, owner, name, desc);
        insertDeadcode();
    }

    @Override
    public void visitMethodInsn(
        int opcode,
        String owner,
        String name,
        String desc)
    {
        super.visitMethodInsn(opcode, owner, name, desc);
        insertDeadcode();
    }

    @Override
    public void visitInvokeDynamicInsn(
        String name,
        String desc,
        Handle bsm,
        Object... bsmArgs)
    {
        super.visitInvokeDynamicInsn(name, desc, bsm, bsmArgs);
        insertDeadcode();
    }

    @Override
    public void visitJumpInsn(int opcode, Label label) {
        super.visitJumpInsn(opcode, label);
        insertDeadcode();
    }

    @Override
    public void visitLdcInsn(Object cst) {
        super.visitLdcInsn(cst);
        insertDeadcode();
    }

    @Override
    public void visitIincInsn(int var, int increment) {
        super.visitIincInsn(var, increment);
        insertDeadcode();
    }

    @Override
    public void visitTableSwitchInsn(
        int min,
        int max,
        Label dflt,
        Label... labels)
    {
        super.visitTableSwitchInsn(min, max, dflt, labels);
        insertDeadcode();
    }

    @Override
    public void visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels) {
        super.visitLookupSwitchInsn(dflt, keys, labels);
        insertDeadcode();
    }

    @Override
    public void visitMultiANewArrayInsn(String desc, int dims) {
        super.visitMultiANewArrayInsn(desc, dims);
        insertDeadcode();
    }

    private void insertDeadcode() {
        // inserts dead code once every 50 instructions in average
        if (r.nextFloat() < 1.0 / 50.0) {
            Label end = new Label();
            mv.visitJumpInsn(Opcodes.GOTO, end);
            mv.visitLdcInsn("DEAD CODE");
            mv.visitLabel(end);
        }
    }
}
