/**
  * Closes the given print stream, or closes it if is the standard output.
  *
  * @param printStream
  */
 private void closePrintStream(PrintStream printStream) {
   if (printStream == System.out) {
     printStream.flush();
   } else {
     printStream.close();
   }
 }
  /** Performs obfuscation of the given program class pool. */
  public void execute(ClassPool programClassPool, ClassPool libraryClassPool) throws IOException {
    // Check if we have at least some keep commands.
    if (configuration.keep == null
        && configuration.applyMapping == null
        && configuration.printMapping == null) {
      throw new IOException("You have to specify '-keep' options for the obfuscation step.");
    }

    // Clean up any old visitor info.
    programClassPool.classesAccept(new ClassCleaner());
    libraryClassPool.classesAccept(new ClassCleaner());

    // If the class member names have to correspond globally,
    // link all class members in all classes, otherwise
    // link all non-private methods in all class hierarchies.
    ClassVisitor memberInfoLinker =
        configuration.useUniqueClassMemberNames
            ? (ClassVisitor) new AllMemberVisitor(new MethodLinker())
            : (ClassVisitor) new BottomClassFilter(new MethodLinker());

    programClassPool.classesAccept(memberInfoLinker);
    libraryClassPool.classesAccept(memberInfoLinker);

    // Create a visitor for marking the seeds.
    NameMarker nameMarker = new NameMarker();
    ClassPoolVisitor classPoolvisitor =
        ClassSpecificationVisitorFactory.createClassPoolVisitor(
            configuration.keep, nameMarker, nameMarker, false, false, true);
    // Mark the seeds.
    programClassPool.accept(classPoolvisitor);
    libraryClassPool.accept(classPoolvisitor);

    // All library classes and library class members keep their names.
    libraryClassPool.classesAccept(nameMarker);
    libraryClassPool.classesAccept(new AllMemberVisitor(nameMarker));

    // Mark attributes that have to be kept.
    AttributeUsageMarker requiredAttributeUsageMarker = new AttributeUsageMarker();

    AttributeVisitor optionalAttributeUsageMarker =
        configuration.keepAttributes == null
            ? null
            : new AttributeNameFilter(
                new ListParser(new NameParser()).parse(configuration.keepAttributes),
                requiredAttributeUsageMarker);

    programClassPool.classesAccept(
        new AllAttributeVisitor(
            true,
            new RequiredAttributeFilter(
                requiredAttributeUsageMarker, optionalAttributeUsageMarker)));

    // Remove the attributes that can be discarded. Note that the attributes
    // may only be discarded after the seeds have been marked, since the
    // configuration may rely on annotations.
    programClassPool.classesAccept(new AttributeShrinker());

    // Apply the mapping, if one has been specified. The mapping can
    // override the names of library classes and of library class members.
    if (configuration.applyMapping != null) {
      WarningPrinter warningPrinter = new WarningPrinter(System.err, configuration.warn);

      MappingReader reader = new MappingReader(configuration.applyMapping);

      MappingProcessor keeper =
          new MultiMappingProcessor(
              new MappingProcessor[] {
                new MappingKeeper(programClassPool, warningPrinter),
                new MappingKeeper(libraryClassPool, null),
              });

      reader.pump(keeper);

      // Print out a summary of the warnings if necessary.
      int mappingWarningCount = warningPrinter.getWarningCount();
      if (mappingWarningCount > 0) {
        System.err.println(
            "Warning: there were "
                + mappingWarningCount
                + " kept classes and class members that were remapped anyway.");
        System.err.println(
            "         You should adapt your configuration or edit the mapping file.");

        if (!configuration.ignoreWarnings) {
          System.err.println("         If you are sure this remapping won't hurt,");
          System.err.println(
              "         you could try your luck using the '-ignorewarnings' option.");
          throw new IOException("Please correct the above warnings first.");
        }
      }
    }

    // Come up with new names for all classes.
    DictionaryNameFactory classNameFactory =
        configuration.classObfuscationDictionary != null
            ? new DictionaryNameFactory(configuration.classObfuscationDictionary, null)
            : null;

    DictionaryNameFactory packageNameFactory =
        configuration.packageObfuscationDictionary != null
            ? new DictionaryNameFactory(configuration.packageObfuscationDictionary, null)
            : null;

    programClassPool.classesAccept(
        new ClassObfuscator(
            programClassPool,
            classNameFactory,
            packageNameFactory,
            configuration.useMixedCaseClassNames,
            configuration.keepPackageNames,
            configuration.flattenPackageHierarchy,
            configuration.repackageClasses,
            configuration.allowAccessModification));

    // Come up with new names for all class members.
    NameFactory nameFactory = new SimpleNameFactory();

    if (configuration.obfuscationDictionary != null) {
      nameFactory = new DictionaryNameFactory(configuration.obfuscationDictionary, nameFactory);
    }

    WarningPrinter warningPrinter = new WarningPrinter(System.err, configuration.warn);

    // Maintain a map of names to avoid [descriptor - new name - old name].
    Map descriptorMap = new HashMap();

    // Do the class member names have to be globally unique?
    if (configuration.useUniqueClassMemberNames) {
      // Collect all member names in all classes.
      programClassPool.classesAccept(
          new AllMemberVisitor(
              new MemberNameCollector(configuration.overloadAggressively, descriptorMap)));

      // Assign new names to all members in all classes.
      programClassPool.classesAccept(
          new AllMemberVisitor(
              new MemberObfuscator(
                  configuration.overloadAggressively, nameFactory, descriptorMap)));
    } else {
      // Come up with new names for all non-private class members.
      programClassPool.classesAccept(
          new MultiClassVisitor(
              new ClassVisitor[] {
                // Collect all private member names in this class and down
                // the hierarchy.
                new ClassHierarchyTraveler(
                    true,
                    false,
                    false,
                    true,
                    new AllMemberVisitor(
                        new MemberAccessFilter(
                            ClassConstants.INTERNAL_ACC_PRIVATE,
                            0,
                            new MemberNameCollector(
                                configuration.overloadAggressively, descriptorMap)))),

                // Collect all non-private member names anywhere in the hierarchy.
                new ClassHierarchyTraveler(
                    true,
                    true,
                    true,
                    true,
                    new AllMemberVisitor(
                        new MemberAccessFilter(
                            0,
                            ClassConstants.INTERNAL_ACC_PRIVATE,
                            new MemberNameCollector(
                                configuration.overloadAggressively, descriptorMap)))),

                // Assign new names to all non-private members in this class.
                new AllMemberVisitor(
                    new MemberAccessFilter(
                        0,
                        ClassConstants.INTERNAL_ACC_PRIVATE,
                        new MemberObfuscator(
                            configuration.overloadAggressively, nameFactory, descriptorMap))),

                // Clear the collected names.
                new MapCleaner(descriptorMap)
              }));

      // Come up with new names for all private class members.
      programClassPool.classesAccept(
          new MultiClassVisitor(
              new ClassVisitor[] {
                // Collect all member names in this class.
                new AllMemberVisitor(
                    new MemberNameCollector(configuration.overloadAggressively, descriptorMap)),

                // Collect all non-private member names higher up the hierarchy.
                new ClassHierarchyTraveler(
                    false,
                    true,
                    true,
                    false,
                    new AllMemberVisitor(
                        new MemberAccessFilter(
                            0,
                            ClassConstants.INTERNAL_ACC_PRIVATE,
                            new MemberNameCollector(
                                configuration.overloadAggressively, descriptorMap)))),

                // Assign new names to all private members in this class.
                new AllMemberVisitor(
                    new MemberAccessFilter(
                        ClassConstants.INTERNAL_ACC_PRIVATE,
                        0,
                        new MemberObfuscator(
                            configuration.overloadAggressively, nameFactory, descriptorMap))),

                // Clear the collected names.
                new MapCleaner(descriptorMap)
              }));
    }

    // Some class members may have ended up with conflicting names.
    // Come up with new, globally unique names for them.
    NameFactory specialNameFactory = new SpecialNameFactory(new SimpleNameFactory());

    // Collect a map of special names to avoid
    // [descriptor - new name - old name].
    Map specialDescriptorMap = new HashMap();

    programClassPool.classesAccept(
        new AllMemberVisitor(
            new MemberSpecialNameFilter(
                new MemberNameCollector(
                    configuration.overloadAggressively, specialDescriptorMap))));

    libraryClassPool.classesAccept(
        new AllMemberVisitor(
            new MemberSpecialNameFilter(
                new MemberNameCollector(
                    configuration.overloadAggressively, specialDescriptorMap))));

    // Replace conflicting non-private member names with special names.
    programClassPool.classesAccept(
        new MultiClassVisitor(
            new ClassVisitor[] {
              // Collect all private member names in this class and down
              // the hierarchy.
              new ClassHierarchyTraveler(
                  true,
                  false,
                  false,
                  true,
                  new AllMemberVisitor(
                      new MemberAccessFilter(
                          ClassConstants.INTERNAL_ACC_PRIVATE,
                          0,
                          new MemberNameCollector(
                              configuration.overloadAggressively, descriptorMap)))),

              // Collect all non-private member names in this class and
              // higher up the hierarchy.
              new ClassHierarchyTraveler(
                  true,
                  true,
                  true,
                  false,
                  new AllMemberVisitor(
                      new MemberAccessFilter(
                          0,
                          ClassConstants.INTERNAL_ACC_PRIVATE,
                          new MemberNameCollector(
                              configuration.overloadAggressively, descriptorMap)))),

              // Assign new names to all conflicting non-private members
              // in this class and higher up the hierarchy.
              new ClassHierarchyTraveler(
                  true,
                  true,
                  true,
                  false,
                  new AllMemberVisitor(
                      new MemberAccessFilter(
                          0,
                          ClassConstants.INTERNAL_ACC_PRIVATE,
                          new MemberNameConflictFixer(
                              configuration.overloadAggressively,
                              descriptorMap,
                              warningPrinter,
                              new MemberObfuscator(
                                  configuration.overloadAggressively,
                                  specialNameFactory,
                                  specialDescriptorMap))))),

              // Clear the collected names.
              new MapCleaner(descriptorMap)
            }));

    // Replace conflicting private member names with special names.
    // This is only possible if those names were kept or mapped.
    programClassPool.classesAccept(
        new MultiClassVisitor(
            new ClassVisitor[] {
              // Collect all member names in this class.
              new AllMemberVisitor(
                  new MemberNameCollector(configuration.overloadAggressively, descriptorMap)),

              // Collect all non-private member names higher up the hierarchy.
              new ClassHierarchyTraveler(
                  false,
                  true,
                  true,
                  false,
                  new AllMemberVisitor(
                      new MemberAccessFilter(
                          0,
                          ClassConstants.INTERNAL_ACC_PRIVATE,
                          new MemberNameCollector(
                              configuration.overloadAggressively, descriptorMap)))),

              // Assign new names to all conflicting private members in this
              // class.
              new AllMemberVisitor(
                  new MemberAccessFilter(
                      ClassConstants.INTERNAL_ACC_PRIVATE,
                      0,
                      new MemberNameConflictFixer(
                          configuration.overloadAggressively,
                          descriptorMap,
                          warningPrinter,
                          new MemberObfuscator(
                              configuration.overloadAggressively,
                              specialNameFactory,
                              specialDescriptorMap)))),

              // Clear the collected names.
              new MapCleaner(descriptorMap)
            }));

    // Print out any warnings about member name conflicts.
    int warningCount = warningPrinter.getWarningCount();
    if (warningCount > 0) {
      System.err.println(
          "Warning: there were " + warningCount + " conflicting class member name mappings.");
      System.err.println("         Your configuration may be inconsistent.");

      if (!configuration.ignoreWarnings) {
        System.err.println("         If you are sure the conflicts are harmless,");
        System.err.println("         you could try your luck using the '-ignorewarnings' option.");
        throw new IOException("Please correct the above warnings first.");
      }
    }

    // Print out the mapping, if requested.
    if (configuration.printMapping != null) {
      PrintStream ps =
          isFile(configuration.printMapping)
              ? new PrintStream(
                  new BufferedOutputStream(new FileOutputStream(configuration.printMapping)))
              : System.out;

      // Print out items that will be removed.
      programClassPool.classesAcceptAlphabetically(new MappingPrinter(ps));

      if (ps != System.out) {
        ps.close();
      }
    }

    // Actually apply the new names.
    programClassPool.classesAccept(new ClassRenamer());
    libraryClassPool.classesAccept(new ClassRenamer());

    // Update all references to these new names.
    programClassPool.classesAccept(new ClassReferenceFixer(false));
    libraryClassPool.classesAccept(new ClassReferenceFixer(false));
    programClassPool.classesAccept(new MemberReferenceFixer());

    // Make package visible elements public or protected, if obfuscated
    // classes are being repackaged aggressively.
    if (configuration.repackageClasses != null && configuration.allowAccessModification) {
      programClassPool.classesAccept(new AllConstantVisitor(new AccessFixer()));
    }

    // Rename the source file attributes, if requested.
    if (configuration.newSourceFileAttribute != null) {
      programClassPool.classesAccept(new SourceFileRenamer(configuration.newSourceFileAttribute));
    }

    // Mark NameAndType constant pool entries that have to be kept
    // and remove the other ones.
    programClassPool.classesAccept(new NameAndTypeUsageMarker());
    programClassPool.classesAccept(new NameAndTypeShrinker());

    // Mark Utf8 constant pool entries that have to be kept
    // and remove the other ones.
    programClassPool.classesAccept(new Utf8UsageMarker());
    programClassPool.classesAccept(new Utf8Shrinker());
  }