/** Print info about this round. */
 private void printRoundInfo(boolean lastRound) {
   if (printRounds || verbose) {
     List<ClassSymbol> tlc = lastRound ? List.<ClassSymbol>nil() : topLevelClasses;
     Set<TypeElement> ap = lastRound ? Collections.<TypeElement>emptySet() : annotationsPresent;
     log.printNoteLines("x.print.rounds", number, "{" + tlc.toString(", ") + "}", ap, lastRound);
   }
 }
    /** Run a processing round. */
    void run(boolean lastRound, boolean errorStatus) {
      printRoundInfo(lastRound);

      TaskListener taskListener = context.get(TaskListener.class);
      if (taskListener != null)
        taskListener.started(new TaskEvent(TaskEvent.Kind.ANNOTATION_PROCESSING_ROUND));

      try {
        if (lastRound) {
          filer.setLastRound(true);
          Set<Element> emptyRootElements = Collections.emptySet(); // immutable
          RoundEnvironment renv =
              new JavacRoundEnvironment(
                  true, errorStatus, emptyRootElements, JavacProcessingEnvironment.this);
          discoveredProcs.iterator().runContributingProcs(renv);
        } else {
          discoverAndRunProcs(context, annotationsPresent, topLevelClasses, packageInfoFiles);
        }
      } finally {
        if (taskListener != null)
          taskListener.finished(new TaskEvent(TaskEvent.Kind.ANNOTATION_PROCESSING_ROUND));
      }

      nMessagerErrors = messager.errorCount();
    }
 /**
  * Run all remaining processors on the procStateList that have not already run this round with
  * an empty set of annotations.
  */
 public void runContributingProcs(RoundEnvironment re) {
   if (!onProcInterator) {
     Set<TypeElement> emptyTypeElements = Collections.emptySet();
     while (innerIter.hasNext()) {
       ProcessorState ps = innerIter.next();
       if (ps.contributed) callProcessor(ps.processor, emptyTypeElements, re);
     }
   }
 }
/**
 * Objects of this class hold and manage the state needed to support annotation processing.
 *
 * <p><b>This is NOT part of any supported API. If you write code that depends on this, you do so at
 * your own risk. This code and its internal interfaces are subject to change or deletion without
 * notice.</b>
 */
public class JavacProcessingEnvironment implements ProcessingEnvironment, Closeable {
  Options options;

  private final boolean printProcessorInfo;
  private final boolean printRounds;
  private final boolean verbose;
  private final boolean lint;
  private final boolean procOnly;
  private final boolean fatalErrors;
  private final boolean werror;
  private final boolean showResolveErrors;
  private boolean foundTypeProcessors;

  private final JavacFiler filer;
  private final JavacMessager messager;
  private final JavacElements elementUtils;
  private final JavacTypes typeUtils;

  /** Holds relevant state history of which processors have been used. */
  private DiscoveredProcessors discoveredProcs;

  /** Map of processor-specific options. */
  private final Map<String, String> processorOptions;

  /** */
  private final Set<String> unmatchedProcessorOptions;

  /** Annotations implicitly processed and claimed by javac. */
  private final Set<String> platformAnnotations;

  /** Set of packages given on command line. */
  private Set<PackageSymbol> specifiedPackages = Collections.emptySet();

  /** The log to be used for error reporting. */
  Log log;

  /** Diagnostic factory. */
  JCDiagnostic.Factory diags;

  /** Source level of the compile. */
  Source source;

  private ClassLoader processorClassLoader;

  /** JavacMessages object used for localization */
  private JavacMessages messages;

  private Context context;

  public JavacProcessingEnvironment(Context context, Iterable<? extends Processor> processors) {
    this.context = context;
    log = Log.instance(context);
    source = Source.instance(context);
    diags = JCDiagnostic.Factory.instance(context);
    options = Options.instance(context);
    printProcessorInfo = options.isSet(XPRINTPROCESSORINFO);
    printRounds = options.isSet(XPRINTROUNDS);
    verbose = options.isSet(VERBOSE);
    lint = Lint.instance(context).isEnabled(PROCESSING);
    procOnly = options.isSet(PROC, "only") || options.isSet(XPRINT);
    fatalErrors = options.isSet("fatalEnterError");
    showResolveErrors = options.isSet("showResolveErrors");
    werror = options.isSet(WERROR);
    platformAnnotations = initPlatformAnnotations();
    foundTypeProcessors = false;

    // Initialize services before any processors are initialized
    // in case processors use them.
    filer = new JavacFiler(context);
    messager = new JavacMessager(context, this);
    elementUtils = JavacElements.instance(context);
    typeUtils = JavacTypes.instance(context);
    processorOptions = initProcessorOptions(context);
    unmatchedProcessorOptions = initUnmatchedProcessorOptions();
    messages = JavacMessages.instance(context);
    initProcessorIterator(context, processors);
  }

  private Set<String> initPlatformAnnotations() {
    Set<String> platformAnnotations = new HashSet<String>();
    platformAnnotations.add("java.lang.Deprecated");
    platformAnnotations.add("java.lang.Override");
    platformAnnotations.add("java.lang.SuppressWarnings");
    platformAnnotations.add("java.lang.annotation.Documented");
    platformAnnotations.add("java.lang.annotation.Inherited");
    platformAnnotations.add("java.lang.annotation.Retention");
    platformAnnotations.add("java.lang.annotation.Target");
    return Collections.unmodifiableSet(platformAnnotations);
  }

  private void initProcessorIterator(Context context, Iterable<? extends Processor> processors) {
    Log log = Log.instance(context);
    Iterator<? extends Processor> processorIterator;

    if (options.isSet(XPRINT)) {
      try {
        Processor processor = PrintingProcessor.class.newInstance();
        processorIterator = List.of(processor).iterator();
      } catch (Throwable t) {
        AssertionError assertError = new AssertionError("Problem instantiating PrintingProcessor.");
        assertError.initCause(t);
        throw assertError;
      }
    } else if (processors != null) {
      processorIterator = processors.iterator();
    } else {
      String processorNames = options.get(PROCESSOR);
      JavaFileManager fileManager = context.get(JavaFileManager.class);
      try {
        // If processorpath is not explicitly set, use the classpath.
        processorClassLoader =
            fileManager.hasLocation(ANNOTATION_PROCESSOR_PATH)
                ? fileManager.getClassLoader(ANNOTATION_PROCESSOR_PATH)
                : fileManager.getClassLoader(CLASS_PATH);

        /*
         * If the "-processor" option is used, search the appropriate
         * path for the named class.  Otherwise, use a service
         * provider mechanism to create the processor iterator.
         */
        if (processorNames != null) {
          processorIterator = new NameProcessIterator(processorNames, processorClassLoader, log);
        } else {
          processorIterator = new ServiceIterator(processorClassLoader, log);
        }
      } catch (SecurityException e) {
        /*
         * A security exception will occur if we can't create a classloader.
         * Ignore the exception if, with hindsight, we didn't need it anyway
         * (i.e. no processor was specified either explicitly, or implicitly,
         * in service configuration file.) Otherwise, we cannot continue.
         */
        processorIterator = handleServiceLoaderUnavailability("proc.cant.create.loader", e);
      }
    }
    discoveredProcs = new DiscoveredProcessors(processorIterator);
  }

  /**
   * Returns an empty processor iterator if no processors are on the relevant path, otherwise if
   * processors are present, logs an error. Called when a service loader is unavailable for some
   * reason, either because a service loader class cannot be found or because a security policy
   * prevents class loaders from being created.
   *
   * @param key The resource key to use to log an error message
   * @param e If non-null, pass this exception to Abort
   */
  private Iterator<Processor> handleServiceLoaderUnavailability(String key, Exception e) {
    JavaFileManager fileManager = context.get(JavaFileManager.class);

    if (fileManager instanceof JavacFileManager) {
      StandardJavaFileManager standardFileManager = (JavacFileManager) fileManager;
      Iterable<? extends File> workingPath =
          fileManager.hasLocation(ANNOTATION_PROCESSOR_PATH)
              ? standardFileManager.getLocation(ANNOTATION_PROCESSOR_PATH)
              : standardFileManager.getLocation(CLASS_PATH);

      if (needClassLoader(options.get(PROCESSOR), workingPath)) handleException(key, e);

    } else {
      handleException(key, e);
    }

    java.util.List<Processor> pl = Collections.emptyList();
    return pl.iterator();
  }

  /** Handle a security exception thrown during initializing the Processor iterator. */
  private void handleException(String key, Exception e) {
    if (e != null) {
      log.error(key, e.getLocalizedMessage());
      throw new Abort(e);
    } else {
      log.error(key);
      throw new Abort();
    }
  }

  /**
   * Use a service loader appropriate for the platform to provide an iterator over annotations
   * processors. If java.util.ServiceLoader is present use it, otherwise, use sun.misc.Service,
   * otherwise fail if a loader is needed.
   */
  private class ServiceIterator implements Iterator<Processor> {
    // The to-be-wrapped iterator.
    private Iterator<?> iterator;
    private Log log;
    private Class<?> loaderClass;
    private boolean jusl;
    private Object loader;

    ServiceIterator(ClassLoader classLoader, Log log) {
      String loadMethodName;

      this.log = log;
      try {
        try {
          loaderClass = Class.forName("java.util.ServiceLoader");
          loadMethodName = "load";
          jusl = true;
        } catch (ClassNotFoundException cnfe) {
          try {
            loaderClass = Class.forName("sun.misc.Service");
            loadMethodName = "providers";
            jusl = false;
          } catch (ClassNotFoundException cnfe2) {
            // Fail softly if a loader is not actually needed.
            this.iterator = handleServiceLoaderUnavailability("proc.no.service", null);
            return;
          }
        }

        // java.util.ServiceLoader.load or sun.misc.Service.providers
        Method loadMethod = loaderClass.getMethod(loadMethodName, Class.class, ClassLoader.class);

        Object result = loadMethod.invoke(null, Processor.class, classLoader);

        // For java.util.ServiceLoader, we have to call another
        // method to get the iterator.
        if (jusl) {
          loader = result; // Store ServiceLoader to call reload later
          Method m = loaderClass.getMethod("iterator");
          result = m.invoke(result); // serviceLoader.iterator();
        }

        // The result should now be an iterator.
        this.iterator = (Iterator<?>) result;
      } catch (Throwable t) {
        log.error("proc.service.problem");
        throw new Abort(t);
      }
    }

    public boolean hasNext() {
      try {
        return iterator.hasNext();
      } catch (Throwable t) {
        if ("ServiceConfigurationError".equals(t.getClass().getSimpleName())) {
          log.error("proc.bad.config.file", t.getLocalizedMessage());
        }
        throw new Abort(t);
      }
    }

    public Processor next() {
      try {
        return (Processor) (iterator.next());
      } catch (Throwable t) {
        if ("ServiceConfigurationError".equals(t.getClass().getSimpleName())) {
          log.error("proc.bad.config.file", t.getLocalizedMessage());
        } else {
          log.error("proc.processor.constructor.error", t.getLocalizedMessage());
        }
        throw new Abort(t);
      }
    }

    public void remove() {
      throw new UnsupportedOperationException();
    }

    public void close() {
      if (jusl) {
        try {
          // Call java.util.ServiceLoader.reload
          Method reloadMethod = loaderClass.getMethod("reload");
          reloadMethod.invoke(loader);
        } catch (Exception e) {; // Ignore problems during a call to reload.
        }
      }
    }
  }

  private static class NameProcessIterator implements Iterator<Processor> {
    Processor nextProc = null;
    Iterator<String> names;
    ClassLoader processorCL;
    Log log;

    NameProcessIterator(String names, ClassLoader processorCL, Log log) {
      this.names = Arrays.asList(names.split(",")).iterator();
      this.processorCL = processorCL;
      this.log = log;
    }

    public boolean hasNext() {
      if (nextProc != null) return true;
      else {
        if (!names.hasNext()) return false;
        else {
          String processorName = names.next();

          Processor processor;
          try {
            try {
              processor = (Processor) (processorCL.loadClass(processorName).newInstance());
            } catch (ClassNotFoundException cnfe) {
              log.error("proc.processor.not.found", processorName);
              return false;
            } catch (ClassCastException cce) {
              log.error("proc.processor.wrong.type", processorName);
              return false;
            } catch (Exception e) {
              log.error("proc.processor.cant.instantiate", processorName);
              return false;
            }
          } catch (ClientCodeException e) {
            throw e;
          } catch (Throwable t) {
            throw new AnnotationProcessingError(t);
          }
          nextProc = processor;
          return true;
        }
      }
    }

    public Processor next() {
      if (hasNext()) {
        Processor p = nextProc;
        nextProc = null;
        return p;
      } else throw new NoSuchElementException();
    }

    public void remove() {
      throw new UnsupportedOperationException();
    }
  }

  public boolean atLeastOneProcessor() {
    return discoveredProcs.iterator().hasNext();
  }

  private Map<String, String> initProcessorOptions(Context context) {
    Options options = Options.instance(context);
    Set<String> keySet = options.keySet();
    Map<String, String> tempOptions = new LinkedHashMap<String, String>();

    for (String key : keySet) {
      if (key.startsWith("-A") && key.length() > 2) {
        int sepIndex = key.indexOf('=');
        String candidateKey = null;
        String candidateValue = null;

        if (sepIndex == -1) candidateKey = key.substring(2);
        else if (sepIndex >= 3) {
          candidateKey = key.substring(2, sepIndex);
          candidateValue = (sepIndex < key.length() - 1) ? key.substring(sepIndex + 1) : null;
        }
        tempOptions.put(candidateKey, candidateValue);
      }
    }

    return Collections.unmodifiableMap(tempOptions);
  }

  private Set<String> initUnmatchedProcessorOptions() {
    Set<String> unmatchedProcessorOptions = new HashSet<String>();
    unmatchedProcessorOptions.addAll(processorOptions.keySet());
    return unmatchedProcessorOptions;
  }

  /**
   * State about how a processor has been used by the tool. If a processor has been used on a prior
   * round, its process method is called on all subsequent rounds, perhaps with an empty set of
   * annotations to process. The {@code annotatedSupported} method caches the supported annotation
   * information from the first (and only) getSupportedAnnotationTypes call to the processor.
   */
  static class ProcessorState {
    public Processor processor;
    public boolean contributed;
    private ArrayList<Pattern> supportedAnnotationPatterns;
    private ArrayList<String> supportedOptionNames;

    ProcessorState(Processor p, Log log, Source source, ProcessingEnvironment env) {
      processor = p;
      contributed = false;

      try {
        processor.init(env);

        checkSourceVersionCompatibility(source, log);

        supportedAnnotationPatterns = new ArrayList<Pattern>();
        for (String importString : processor.getSupportedAnnotationTypes()) {
          supportedAnnotationPatterns.add(importStringToPattern(importString, processor, log));
        }

        supportedOptionNames = new ArrayList<String>();
        for (String optionName : processor.getSupportedOptions()) {
          if (checkOptionName(optionName, log)) supportedOptionNames.add(optionName);
        }

      } catch (ClientCodeException e) {
        throw e;
      } catch (Throwable t) {
        throw new AnnotationProcessingError(t);
      }
    }

    /**
     * Checks whether or not a processor's source version is compatible with the compilation source
     * version. The processor's source version needs to be greater than or equal to the source
     * version of the compile.
     */
    private void checkSourceVersionCompatibility(Source source, Log log) {
      SourceVersion procSourceVersion = processor.getSupportedSourceVersion();

      if (procSourceVersion.compareTo(Source.toSourceVersion(source)) < 0) {
        log.warning(
            "proc.processor.incompatible.source.version",
            procSourceVersion,
            processor.getClass().getName(),
            source.name);
      }
    }

    private boolean checkOptionName(String optionName, Log log) {
      boolean valid = isValidOptionName(optionName);
      if (!valid)
        log.error("proc.processor.bad.option.name", optionName, processor.getClass().getName());
      return valid;
    }

    public boolean annotationSupported(String annotationName) {
      for (Pattern p : supportedAnnotationPatterns) {
        if (p.matcher(annotationName).matches()) return true;
      }
      return false;
    }

    /** Remove options that are matched by this processor. */
    public void removeSupportedOptions(Set<String> unmatchedProcessorOptions) {
      unmatchedProcessorOptions.removeAll(supportedOptionNames);
    }
  }

  // TODO: These two classes can probably be rewritten better...
  /**
   * This class holds information about the processors that have been discoverd so far as well as
   * the means to discover more, if necessary. A single iterator should be used per round of
   * annotation processing. The iterator first visits already discovered processors then fails over
   * to the service provider mechanism if additional queries are made.
   */
  class DiscoveredProcessors implements Iterable<ProcessorState> {

    class ProcessorStateIterator implements Iterator<ProcessorState> {
      DiscoveredProcessors psi;
      Iterator<ProcessorState> innerIter;
      boolean onProcInterator;

      ProcessorStateIterator(DiscoveredProcessors psi) {
        this.psi = psi;
        this.innerIter = psi.procStateList.iterator();
        this.onProcInterator = false;
      }

      public ProcessorState next() {
        if (!onProcInterator) {
          if (innerIter.hasNext()) return innerIter.next();
          else onProcInterator = true;
        }

        if (psi.processorIterator.hasNext()) {
          ProcessorState ps =
              new ProcessorState(
                  psi.processorIterator.next(), log, source, JavacProcessingEnvironment.this);
          psi.procStateList.add(ps);
          return ps;
        } else throw new NoSuchElementException();
      }

      public boolean hasNext() {
        if (onProcInterator) return psi.processorIterator.hasNext();
        else return innerIter.hasNext() || psi.processorIterator.hasNext();
      }

      public void remove() {
        throw new UnsupportedOperationException();
      }

      /**
       * Run all remaining processors on the procStateList that have not already run this round with
       * an empty set of annotations.
       */
      public void runContributingProcs(RoundEnvironment re) {
        if (!onProcInterator) {
          Set<TypeElement> emptyTypeElements = Collections.emptySet();
          while (innerIter.hasNext()) {
            ProcessorState ps = innerIter.next();
            if (ps.contributed) callProcessor(ps.processor, emptyTypeElements, re);
          }
        }
      }
    }

    Iterator<? extends Processor> processorIterator;
    ArrayList<ProcessorState> procStateList;

    public ProcessorStateIterator iterator() {
      return new ProcessorStateIterator(this);
    }

    DiscoveredProcessors(Iterator<? extends Processor> processorIterator) {
      this.processorIterator = processorIterator;
      this.procStateList = new ArrayList<ProcessorState>();
    }

    /** Free jar files, etc. if using a service loader. */
    public void close() {
      if (processorIterator != null && processorIterator instanceof ServiceIterator) {
        ((ServiceIterator) processorIterator).close();
      }
    }
  }

  private void discoverAndRunProcs(
      Context context,
      Set<TypeElement> annotationsPresent,
      List<ClassSymbol> topLevelClasses,
      List<PackageSymbol> packageInfoFiles) {
    Map<String, TypeElement> unmatchedAnnotations =
        new HashMap<String, TypeElement>(annotationsPresent.size());

    for (TypeElement a : annotationsPresent) {
      unmatchedAnnotations.put(a.getQualifiedName().toString(), a);
    }

    // Give "*" processors a chance to match
    if (unmatchedAnnotations.size() == 0) unmatchedAnnotations.put("", null);

    DiscoveredProcessors.ProcessorStateIterator psi = discoveredProcs.iterator();
    // TODO: Create proper argument values; need past round
    // information to fill in this constructor.  Note that the 1
    // st round of processing could be the last round if there
    // were parse errors on the initial source files; however, we
    // are not doing processing in that case.

    Set<Element> rootElements = new LinkedHashSet<Element>();
    rootElements.addAll(topLevelClasses);
    rootElements.addAll(packageInfoFiles);
    rootElements = Collections.unmodifiableSet(rootElements);

    RoundEnvironment renv =
        new JavacRoundEnvironment(false, false, rootElements, JavacProcessingEnvironment.this);

    while (unmatchedAnnotations.size() > 0 && psi.hasNext()) {
      ProcessorState ps = psi.next();
      Set<String> matchedNames = new HashSet<String>();
      Set<TypeElement> typeElements = new LinkedHashSet<TypeElement>();

      for (Map.Entry<String, TypeElement> entry : unmatchedAnnotations.entrySet()) {
        String unmatchedAnnotationName = entry.getKey();
        if (ps.annotationSupported(unmatchedAnnotationName)) {
          matchedNames.add(unmatchedAnnotationName);
          TypeElement te = entry.getValue();
          if (te != null) typeElements.add(te);
        }
      }

      if (matchedNames.size() > 0 || ps.contributed) {
        boolean processingResult = callProcessor(ps.processor, typeElements, renv);
        ps.contributed = true;
        ps.removeSupportedOptions(unmatchedProcessorOptions);

        if (printProcessorInfo || verbose) {
          log.printNoteLines(
              "x.print.processor.info",
              ps.processor.getClass().getName(),
              matchedNames.toString(),
              processingResult);
        }

        if (processingResult) {
          unmatchedAnnotations.keySet().removeAll(matchedNames);
        }
      }
    }
    unmatchedAnnotations.remove("");

    if (lint && unmatchedAnnotations.size() > 0) {
      // Remove annotations processed by javac
      unmatchedAnnotations.keySet().removeAll(platformAnnotations);
      if (unmatchedAnnotations.size() > 0) {
        log = Log.instance(context);
        log.warning("proc.annotations.without.processors", unmatchedAnnotations.keySet());
      }
    }

    // Run contributing processors that haven't run yet
    psi.runContributingProcs(renv);

    // Debugging
    if (options.isSet("displayFilerState")) filer.displayState();
  }

  /**
   * Computes the set of annotations on the symbol in question. Leave class public for external
   * testing purposes.
   */
  public static class ComputeAnnotationSet
      extends ElementScanner7<Set<TypeElement>, Set<TypeElement>> {
    final Elements elements;

    public ComputeAnnotationSet(Elements elements) {
      super();
      this.elements = elements;
    }

    @Override
    public Set<TypeElement> visitPackage(PackageElement e, Set<TypeElement> p) {
      // Don't scan enclosed elements of a package
      return p;
    }

    @Override
    public Set<TypeElement> scan(Element e, Set<TypeElement> p) {
      for (AnnotationMirror annotationMirror : elements.getAllAnnotationMirrors(e)) {
        Element e2 = annotationMirror.getAnnotationType().asElement();
        p.add((TypeElement) e2);
      }
      return super.scan(e, p);
    }
  }

  private boolean callProcessor(
      Processor proc, Set<? extends TypeElement> tes, RoundEnvironment renv) {
    try {
      return proc.process(tes, renv);
    } catch (BadClassFile ex) {
      log.error("proc.cant.access.1", ex.sym, ex.getDetailValue());
      return false;
    } catch (CompletionFailure ex) {
      StringWriter out = new StringWriter();
      ex.printStackTrace(new PrintWriter(out));
      log.error("proc.cant.access", ex.sym, ex.getDetailValue(), out.toString());
      return false;
    } catch (ClientCodeException e) {
      throw e;
    } catch (Throwable t) {
      throw new AnnotationProcessingError(t);
    }
  }

  /** Helper object for a single round of annotation processing. */
  class Round {
    /** The round number. */
    final int number;
    /** The context for the round. */
    final Context context;
    /** The compiler for the round. */
    final JavaCompiler compiler;
    /** The log for the round. */
    final Log log;

    /** The ASTs to be compiled. */
    List<JCCompilationUnit> roots;
    /** The classes to be compiler that have were generated. */
    Map<String, JavaFileObject> genClassFiles;

    /** The set of annotations to be processed this round. */
    Set<TypeElement> annotationsPresent;
    /** The set of top level classes to be processed this round. */
    List<ClassSymbol> topLevelClasses;
    /** The set of package-info files to be processed this round. */
    List<PackageSymbol> packageInfoFiles;

    /** The number of Messager errors generated in this round. */
    int nMessagerErrors;

    /** Create a round (common code). */
    private Round(Context context, int number, int priorErrors, int priorWarnings) {
      this.context = context;
      this.number = number;

      compiler = JavaCompiler.instance(context);
      log = Log.instance(context);
      log.nerrors = priorErrors;
      log.nwarnings += priorWarnings;
      log.deferDiagnostics = true;

      // the following is for the benefit of JavacProcessingEnvironment.getContext()
      JavacProcessingEnvironment.this.context = context;

      // the following will be populated as needed
      topLevelClasses = List.nil();
      packageInfoFiles = List.nil();
    }

    /** Create the first round. */
    Round(Context context, List<JCCompilationUnit> roots, List<ClassSymbol> classSymbols) {
      this(context, 1, 0, 0);
      this.roots = roots;
      genClassFiles = new HashMap<String, JavaFileObject>();

      compiler.todo.clear(); // free the compiler's resources

      // The reverse() in the following line is to maintain behavioural
      // compatibility with the previous revision of the code. Strictly speaking,
      // it should not be necessary, but a javah golden file test fails without it.
      topLevelClasses = getTopLevelClasses(roots).prependList(classSymbols.reverse());

      packageInfoFiles = getPackageInfoFiles(roots);

      findAnnotationsPresent();
    }

    /** Create a new round. */
    private Round(
        Round prev, Set<JavaFileObject> newSourceFiles, Map<String, JavaFileObject> newClassFiles) {
      this(prev.nextContext(), prev.number + 1, prev.nMessagerErrors, prev.compiler.log.nwarnings);
      this.genClassFiles = prev.genClassFiles;

      List<JCCompilationUnit> parsedFiles = compiler.parseFiles(newSourceFiles);
      roots = cleanTrees(prev.roots).appendList(parsedFiles);

      // Check for errors after parsing
      if (unrecoverableError()) return;

      enterClassFiles(genClassFiles);
      List<ClassSymbol> newClasses = enterClassFiles(newClassFiles);
      genClassFiles.putAll(newClassFiles);
      enterTrees(roots);

      if (unrecoverableError()) return;

      topLevelClasses =
          join(getTopLevelClasses(parsedFiles), getTopLevelClassesFromClasses(newClasses));

      packageInfoFiles =
          join(getPackageInfoFiles(parsedFiles), getPackageInfoFilesFromClasses(newClasses));

      findAnnotationsPresent();
    }

    /** Create the next round to be used. */
    Round next(Set<JavaFileObject> newSourceFiles, Map<String, JavaFileObject> newClassFiles) {
      try {
        return new Round(this, newSourceFiles, newClassFiles);
      } finally {
        compiler.close(false);
      }
    }

    /** Create the compiler to be used for the final compilation. */
    JavaCompiler finalCompiler(boolean errorStatus) {
      try {
        JavaCompiler c = JavaCompiler.instance(nextContext());
        c.log.nwarnings += compiler.log.nwarnings;
        if (errorStatus) {
          c.log.nerrors += compiler.log.nerrors;
        }
        return c;
      } finally {
        compiler.close(false);
      }
    }

    /**
     * Return the number of errors found so far in this round. This may include uncoverable errors,
     * such as parse errors, and transient errors, such as missing symbols.
     */
    int errorCount() {
      return compiler.errorCount();
    }

    /** Return the number of warnings found so far in this round. */
    int warningCount() {
      return compiler.warningCount();
    }

    /** Return whether or not an unrecoverable error has occurred. */
    boolean unrecoverableError() {
      if (messager.errorRaised()) return true;

      for (JCDiagnostic d : log.deferredDiagnostics) {
        switch (d.getKind()) {
          case WARNING:
            if (werror) return true;
            break;

          case ERROR:
            if (fatalErrors || !d.isFlagSet(RECOVERABLE)) return true;
            break;
        }
      }

      return false;
    }

    /**
     * Find the set of annotations present in the set of top level classes and package info files to
     * be processed this round.
     */
    void findAnnotationsPresent() {
      ComputeAnnotationSet annotationComputer = new ComputeAnnotationSet(elementUtils);
      // Use annotation processing to compute the set of annotations present
      annotationsPresent = new LinkedHashSet<TypeElement>();
      for (ClassSymbol classSym : topLevelClasses)
        annotationComputer.scan(classSym, annotationsPresent);
      for (PackageSymbol pkgSym : packageInfoFiles)
        annotationComputer.scan(pkgSym, annotationsPresent);
    }

    /** Enter a set of generated class files. */
    private List<ClassSymbol> enterClassFiles(Map<String, JavaFileObject> classFiles) {
      ClassReader reader = ClassReader.instance(context);
      Names names = Names.instance(context);
      List<ClassSymbol> list = List.nil();

      for (Map.Entry<String, JavaFileObject> entry : classFiles.entrySet()) {
        Name name = names.fromString(entry.getKey());
        JavaFileObject file = entry.getValue();
        if (file.getKind() != JavaFileObject.Kind.CLASS) throw new AssertionError(file);
        ClassSymbol cs;
        if (isPkgInfo(file, JavaFileObject.Kind.CLASS)) {
          Name packageName = Convert.packagePart(name);
          PackageSymbol p = reader.enterPackage(packageName);
          if (p.package_info == null)
            p.package_info = reader.enterClass(Convert.shortName(name), p);
          cs = p.package_info;
          if (cs.classfile == null) cs.classfile = file;
        } else cs = reader.enterClass(name, file);
        list = list.prepend(cs);
      }
      return list.reverse();
    }

    /** Enter a set of syntax trees. */
    private void enterTrees(List<JCCompilationUnit> roots) {
      compiler.enterTrees(roots);
    }

    /** Run a processing round. */
    void run(boolean lastRound, boolean errorStatus) {
      printRoundInfo(lastRound);

      TaskListener taskListener = context.get(TaskListener.class);
      if (taskListener != null)
        taskListener.started(new TaskEvent(TaskEvent.Kind.ANNOTATION_PROCESSING_ROUND));

      try {
        if (lastRound) {
          filer.setLastRound(true);
          Set<Element> emptyRootElements = Collections.emptySet(); // immutable
          RoundEnvironment renv =
              new JavacRoundEnvironment(
                  true, errorStatus, emptyRootElements, JavacProcessingEnvironment.this);
          discoveredProcs.iterator().runContributingProcs(renv);
        } else {
          discoverAndRunProcs(context, annotationsPresent, topLevelClasses, packageInfoFiles);
        }
      } finally {
        if (taskListener != null)
          taskListener.finished(new TaskEvent(TaskEvent.Kind.ANNOTATION_PROCESSING_ROUND));
      }

      nMessagerErrors = messager.errorCount();
    }

    void showDiagnostics(boolean showAll) {
      Set<JCDiagnostic.Kind> kinds = EnumSet.allOf(JCDiagnostic.Kind.class);
      if (!showAll) {
        // suppress errors, which are all presumed to be transient resolve errors
        kinds.remove(JCDiagnostic.Kind.ERROR);
      }
      log.reportDeferredDiagnostics(kinds);
    }

    /** Print info about this round. */
    private void printRoundInfo(boolean lastRound) {
      if (printRounds || verbose) {
        List<ClassSymbol> tlc = lastRound ? List.<ClassSymbol>nil() : topLevelClasses;
        Set<TypeElement> ap = lastRound ? Collections.<TypeElement>emptySet() : annotationsPresent;
        log.printNoteLines("x.print.rounds", number, "{" + tlc.toString(", ") + "}", ap, lastRound);
      }
    }

    /**
     * Get the context for the next round of processing. Important values are propogated from round
     * to round; other values are implicitly reset.
     */
    private Context nextContext() {
      Context next = new Context(context);

      Options options = Options.instance(context);
      Assert.checkNonNull(options);
      next.put(Options.optionsKey, options);

      PrintWriter out = context.get(Log.outKey);
      Assert.checkNonNull(out);
      next.put(Log.outKey, out);
      Locale locale = context.get(Locale.class);
      if (locale != null) next.put(Locale.class, locale);
      Assert.checkNonNull(messages);
      next.put(JavacMessages.messagesKey, messages);

      final boolean shareNames = true;
      if (shareNames) {
        Names names = Names.instance(context);
        Assert.checkNonNull(names);
        next.put(Names.namesKey, names);
      }

      DiagnosticListener<?> dl = context.get(DiagnosticListener.class);
      if (dl != null) next.put(DiagnosticListener.class, dl);

      TaskListener tl = context.get(TaskListener.class);
      if (tl != null) next.put(TaskListener.class, tl);

      FSInfo fsInfo = context.get(FSInfo.class);
      if (fsInfo != null) next.put(FSInfo.class, fsInfo);

      JavaFileManager jfm = context.get(JavaFileManager.class);
      Assert.checkNonNull(jfm);
      next.put(JavaFileManager.class, jfm);
      if (jfm instanceof JavacFileManager) {
        ((JavacFileManager) jfm).setContext(next);
      }

      Names names = Names.instance(context);
      Assert.checkNonNull(names);
      next.put(Names.namesKey, names);

      Keywords keywords = Keywords.instance(context);
      Assert.checkNonNull(keywords);
      next.put(Keywords.keywordsKey, keywords);

      JavaCompiler oldCompiler = JavaCompiler.instance(context);
      JavaCompiler nextCompiler = JavaCompiler.instance(next);
      nextCompiler.initRound(oldCompiler);

      filer.newRound(next);
      messager.newRound(next);
      elementUtils.setContext(next);
      typeUtils.setContext(next);

      JavacTaskImpl task = context.get(JavacTaskImpl.class);
      if (task != null) {
        next.put(JavacTaskImpl.class, task);
        task.updateContext(next);
      }

      JavacTrees trees = context.get(JavacTrees.class);
      if (trees != null) {
        next.put(JavacTrees.class, trees);
        trees.updateContext(next);
      }

      context.clear();
      return next;
    }
  }

  // TODO: internal catch clauses?; catch and rethrow an annotation
  // processing error
  public JavaCompiler doProcessing(
      Context context,
      List<JCCompilationUnit> roots,
      List<ClassSymbol> classSymbols,
      Iterable<? extends PackageSymbol> pckSymbols) {

    TaskListener taskListener = context.get(TaskListener.class);
    log = Log.instance(context);

    Set<PackageSymbol> specifiedPackages = new LinkedHashSet<PackageSymbol>();
    for (PackageSymbol psym : pckSymbols) specifiedPackages.add(psym);
    this.specifiedPackages = Collections.unmodifiableSet(specifiedPackages);

    Round round = new Round(context, roots, classSymbols);

    boolean errorStatus;
    boolean moreToDo;
    do {
      // Run processors for round n
      round.run(false, false);

      // Processors for round n have run to completion.
      // Check for errors and whether there is more work to do.
      errorStatus = round.unrecoverableError();
      moreToDo = moreToDo();

      round.showDiagnostics(errorStatus || showResolveErrors);

      // Set up next round.
      // Copy mutable collections returned from filer.
      round =
          round.next(
              new LinkedHashSet<JavaFileObject>(filer.getGeneratedSourceFileObjects()),
              new LinkedHashMap<String, JavaFileObject>(filer.getGeneratedClasses()));

      // Check for errors during setup.
      if (round.unrecoverableError()) errorStatus = true;

    } while (moreToDo && !errorStatus);

    // run last round
    round.run(true, errorStatus);
    round.showDiagnostics(true);

    filer.warnIfUnclosedFiles();
    warnIfUnmatchedOptions();

    /*
     * If an annotation processor raises an error in a round,
     * that round runs to completion and one last round occurs.
     * The last round may also occur because no more source or
     * class files have been generated.  Therefore, if an error
     * was raised on either of the last *two* rounds, the compile
     * should exit with a nonzero exit code.  The current value of
     * errorStatus holds whether or not an error was raised on the
     * second to last round; errorRaised() gives the error status
     * of the last round.
     */
    if (messager.errorRaised() || werror && round.warningCount() > 0 && round.errorCount() > 0)
      errorStatus = true;

    Set<JavaFileObject> newSourceFiles =
        new LinkedHashSet<JavaFileObject>(filer.getGeneratedSourceFileObjects());
    roots = cleanTrees(round.roots);

    JavaCompiler compiler = round.finalCompiler(errorStatus);

    if (newSourceFiles.size() > 0) roots = roots.appendList(compiler.parseFiles(newSourceFiles));

    errorStatus = errorStatus || (compiler.errorCount() > 0);

    // Free resources
    this.close();

    if (taskListener != null)
      taskListener.finished(new TaskEvent(TaskEvent.Kind.ANNOTATION_PROCESSING));

    if (errorStatus) {
      if (compiler.errorCount() == 0) compiler.log.nerrors++;
      return compiler;
    }

    if (procOnly && !foundTypeProcessors) {
      compiler.todo.clear();
    } else {
      if (procOnly && foundTypeProcessors) compiler.shouldStopPolicy = CompileState.FLOW;

      compiler.enterTrees(roots);
    }

    return compiler;
  }

  private void warnIfUnmatchedOptions() {
    if (!unmatchedProcessorOptions.isEmpty()) {
      log.warning("proc.unmatched.processor.options", unmatchedProcessorOptions.toString());
    }
  }

  /** Free resources related to annotation processing. */
  public void close() {
    filer.close();
    if (discoveredProcs != null) // Make calling close idempotent
    discoveredProcs.close();
    discoveredProcs = null;
    if (processorClassLoader != null && processorClassLoader instanceof Closeable) {
      try {
        ((Closeable) processorClassLoader).close();
      } catch (IOException e) {
        JCDiagnostic msg = diags.fragment("fatal.err.cant.close.loader");
        throw new FatalError(msg, e);
      }
    }
  }

  private List<ClassSymbol> getTopLevelClasses(List<? extends JCCompilationUnit> units) {
    List<ClassSymbol> classes = List.nil();
    for (JCCompilationUnit unit : units) {
      for (JCTree node : unit.defs) {
        if (node.getTag() == JCTree.CLASSDEF) {
          ClassSymbol sym = ((JCClassDecl) node).sym;
          Assert.checkNonNull(sym);
          classes = classes.prepend(sym);
        }
      }
    }
    return classes.reverse();
  }

  private List<ClassSymbol> getTopLevelClassesFromClasses(List<? extends ClassSymbol> syms) {
    List<ClassSymbol> classes = List.nil();
    for (ClassSymbol sym : syms) {
      if (!isPkgInfo(sym)) {
        classes = classes.prepend(sym);
      }
    }
    return classes.reverse();
  }

  private List<PackageSymbol> getPackageInfoFiles(List<? extends JCCompilationUnit> units) {
    List<PackageSymbol> packages = List.nil();
    for (JCCompilationUnit unit : units) {
      if (isPkgInfo(unit.sourcefile, JavaFileObject.Kind.SOURCE)) {
        packages = packages.prepend(unit.packge);
      }
    }
    return packages.reverse();
  }

  private List<PackageSymbol> getPackageInfoFilesFromClasses(List<? extends ClassSymbol> syms) {
    List<PackageSymbol> packages = List.nil();
    for (ClassSymbol sym : syms) {
      if (isPkgInfo(sym)) {
        packages = packages.prepend((PackageSymbol) sym.owner);
      }
    }
    return packages.reverse();
  }

  // avoid unchecked warning from use of varargs
  private static <T> List<T> join(List<T> list1, List<T> list2) {
    return list1.appendList(list2);
  }

  private boolean isPkgInfo(JavaFileObject fo, JavaFileObject.Kind kind) {
    return fo.isNameCompatible("package-info", kind);
  }

  private boolean isPkgInfo(ClassSymbol sym) {
    return isPkgInfo(sym.classfile, JavaFileObject.Kind.CLASS)
        && (sym.packge().package_info == sym);
  }

  /*
   * Called retroactively to determine if a class loader was required,
   * after we have failed to create one.
   */
  private boolean needClassLoader(String procNames, Iterable<? extends File> workingpath) {
    if (procNames != null) return true;

    String procPath;
    URL[] urls = new URL[1];
    for (File pathElement : workingpath) {
      try {
        urls[0] = pathElement.toURI().toURL();
        if (ServiceProxy.hasService(Processor.class, urls)) return true;
      } catch (MalformedURLException ex) {
        throw new AssertionError(ex);
      } catch (ServiceProxy.ServiceConfigurationError e) {
        log.error("proc.bad.config.file", e.getLocalizedMessage());
        return true;
      }
    }

    return false;
  }

  private static <T extends JCTree> List<T> cleanTrees(List<T> nodes) {
    for (T node : nodes) treeCleaner.scan(node);
    return nodes;
  }

  private static TreeScanner treeCleaner =
      new TreeScanner() {
        public void scan(JCTree node) {
          super.scan(node);
          if (node != null) node.type = null;
        }

        public void visitTopLevel(JCCompilationUnit node) {
          node.packge = null;
          super.visitTopLevel(node);
        }

        public void visitClassDef(JCClassDecl node) {
          node.sym = null;
          super.visitClassDef(node);
        }

        public void visitMethodDef(JCMethodDecl node) {
          node.sym = null;
          super.visitMethodDef(node);
        }

        public void visitVarDef(JCVariableDecl node) {
          node.sym = null;
          super.visitVarDef(node);
        }

        public void visitNewClass(JCNewClass node) {
          node.constructor = null;
          super.visitNewClass(node);
        }

        public void visitAssignop(JCAssignOp node) {
          node.operator = null;
          super.visitAssignop(node);
        }

        public void visitUnary(JCUnary node) {
          node.operator = null;
          super.visitUnary(node);
        }

        public void visitBinary(JCBinary node) {
          node.operator = null;
          super.visitBinary(node);
        }

        public void visitSelect(JCFieldAccess node) {
          node.sym = null;
          super.visitSelect(node);
        }

        public void visitIdent(JCIdent node) {
          node.sym = null;
          super.visitIdent(node);
        }
      };

  private boolean moreToDo() {
    return filer.newFiles();
  }

  /**
   * {@inheritdoc}
   *
   * <p>Command line options suitable for presenting to annotation processors. "-Afoo=bar" should be
   * "-Afoo" => "bar".
   */
  public Map<String, String> getOptions() {
    return processorOptions;
  }

  public Messager getMessager() {
    return messager;
  }

  public Filer getFiler() {
    return filer;
  }

  public JavacElements getElementUtils() {
    return elementUtils;
  }

  public JavacTypes getTypeUtils() {
    return typeUtils;
  }

  public SourceVersion getSourceVersion() {
    return Source.toSourceVersion(source);
  }

  public Locale getLocale() {
    return messages.getCurrentLocale();
  }

  public Set<Symbol.PackageSymbol> getSpecifiedPackages() {
    return specifiedPackages;
  }

  private static final Pattern allMatches = Pattern.compile(".*");
  public static final Pattern noMatches = Pattern.compile("(\\P{all})+");

  /**
   * Convert import-style string for supported annotations into a regex matching that string. If the
   * string is a valid import-style string, return a regex that won't match anything.
   */
  private static Pattern importStringToPattern(String s, Processor p, Log log) {
    if (isValidImportString(s)) {
      return validImportStringToPattern(s);
    } else {
      log.warning("proc.malformed.supported.string", s, p.getClass().getName());
      return noMatches; // won't match any valid identifier
    }
  }

  /**
   * Return true if the argument string is a valid import-style string specifying claimed
   * annotations; return false otherwise.
   */
  public static boolean isValidImportString(String s) {
    if (s.equals("*")) return true;

    boolean valid = true;
    String t = s;
    int index = t.indexOf('*');

    if (index != -1) {
      // '*' must be last character...
      if (index == t.length() - 1) {
        // ... any and preceding character must be '.'
        if (index - 1 >= 0) {
          valid = t.charAt(index - 1) == '.';
          // Strip off ".*$" for identifier checks
          t = t.substring(0, t.length() - 2);
        }
      } else return false;
    }

    // Verify string is off the form (javaId \.)+ or javaId
    if (valid) {
      String[] javaIds = t.split("\\.", t.length() + 2);
      for (String javaId : javaIds) valid &= SourceVersion.isIdentifier(javaId);
    }
    return valid;
  }

  public static Pattern validImportStringToPattern(String s) {
    if (s.equals("*")) {
      return allMatches;
    } else {
      String s_prime = s.replace(".", "\\.");

      if (s_prime.endsWith("*")) {
        s_prime = s_prime.substring(0, s_prime.length() - 1) + ".+";
      }

      return Pattern.compile(s_prime);
    }
  }

  /** For internal use only. This method will be removed without warning. */
  public Context getContext() {
    return context;
  }

  public String toString() {
    return "javac ProcessingEnvironment";
  }

  public static boolean isValidOptionName(String optionName) {
    for (String s : optionName.split("\\.", -1)) {
      if (!SourceVersion.isIdentifier(s)) return false;
    }
    return true;
  }
}