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}
     *
     * 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;
        }