/*
 * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.tools.javac.main;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.Collections;
import java.util.EnumSet;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
import java.util.function.Predicate;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Stream;

import javax.lang.model.SourceVersion;
import javax.tools.JavaFileManager;
import javax.tools.JavaFileManager.Location;
import javax.tools.JavaFileObject;
import javax.tools.JavaFileObject.Kind;
import javax.tools.StandardJavaFileManager;
import javax.tools.StandardLocation;

import com.sun.tools.doclint.DocLint;
import com.sun.tools.javac.code.Lint.LintCategory;
import com.sun.tools.javac.code.Source;
import com.sun.tools.javac.file.BaseFileManager;
import com.sun.tools.javac.file.JavacFileManager;
import com.sun.tools.javac.jvm.Profile;
import com.sun.tools.javac.jvm.Target;
import com.sun.tools.javac.main.OptionHelper.GrumpyHelper;
import com.sun.tools.javac.platform.PlatformDescription;
import com.sun.tools.javac.platform.PlatformUtils;
import com.sun.tools.javac.resources.CompilerProperties.Errors;
import com.sun.tools.javac.resources.CompilerProperties.Warnings;
import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.JCDiagnostic;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticInfo;
import com.sun.tools.javac.util.List;
import com.sun.tools.javac.util.ListBuffer;
import com.sun.tools.javac.util.Log;
import com.sun.tools.javac.util.Log.PrefixKind;
import com.sun.tools.javac.util.Log.WriterKind;
import com.sun.tools.javac.util.Options;
import com.sun.tools.javac.util.PropagatedException;

Shared option and argument handling for command line and API usage of javac.
/**
 * Shared option and argument handling for command line and API usage of javac.
 */
public class Arguments {

    
The context key for the arguments.
/**
     * The context key for the arguments.
     */
    public static final Context.Key<Arguments> argsKey = new Context.Key<>();

    private String ownName;
    private Set<String> classNames;
    private Set<Path> files;
    private Map<Option, String> deferredFileManagerOptions;
    private Set<JavaFileObject> fileObjects;
    private boolean emptyAllowed;
    private final Options options;

    private JavaFileManager fileManager;
    private final Log log;
    private final Context context;

    private enum ErrorMode { ILLEGAL_ARGUMENT, ILLEGAL_STATE, LOG };
    private ErrorMode errorMode;
    private boolean errors;

    
Gets the Arguments instance for this context.
Params:
context – the content
Returns:
the Arguments instance for this context./**
     * Gets the Arguments instance for this context.
     *
     * @param context the content
     * @return the Arguments instance for this context.
     */
    public static Arguments instance(Context context) {
        Arguments instance = context.get(argsKey);
        if (instance == null) {
            instance = new Arguments(context);
        }
        return instance;
    }

    protected Arguments(Context context) {
        context.put(argsKey, this);
        options = Options.instance(context);
        log = Log.instance(context);
        this.context = context;

        // Ideally, we could init this here and update/configure it as
        // needed, but right now, initializing a file manager triggers
        // initialization of other items in the context, such as Lint
        // and FSInfo, which should not be initialized until after
        // processArgs
        //        fileManager = context.get(JavaFileManager.class);
    }

    private final OptionHelper cmdLineHelper = new OptionHelper() {
        @Override
        public String get(Option option) {
            return options.get(option);
        }

        @Override
        public void put(String name, String value) {
            options.put(name, value);
        }

        @Override
        public void remove(String name) {
            options.remove(name);
        }

        @Override
        public boolean handleFileManagerOption(Option option, String value) {
            options.put(option, value);
            deferredFileManagerOptions.put(option, value);
            return true;
        }

        @Override
        public Log getLog() {
            return log;
        }

        @Override
        public String getOwnName() {
            return ownName;
        }

        @Override
        public void addFile(Path p) {
            files.add(p);
        }

        @Override
        public void addClassName(String s) {
            classNames.add(s);
        }

    };

    
Initializes this Args instance with a set of command line args.
The args will be processed in conjunction with the full set of
command line options, including -help, -version etc.
The args may also contain class names and filenames.
Any errors during this call, and later during validate, will be reported
to the log.
Params:
ownName – the name of this tool; used to prefix messages
args – the args to be processed/**
     * Initializes this Args instance with a set of command line args.
     * The args will be processed in conjunction with the full set of
     * command line options, including -help, -version etc.
     * The args may also contain class names and filenames.
     * Any errors during this call, and later during validate, will be reported
     * to the log.
     * @param ownName the name of this tool; used to prefix messages
     * @param args the args to be processed
     */
    public void init(String ownName, Iterable<String> args) {
        this.ownName = ownName;
        errorMode = ErrorMode.LOG;
        files = new LinkedHashSet<>();
        deferredFileManagerOptions = new LinkedHashMap<>();
        fileObjects = null;
        classNames = new LinkedHashSet<>();
        processArgs(args, Option.getJavaCompilerOptions(), cmdLineHelper, true, false);
        if (errors) {
            log.printLines(PrefixKind.JAVAC, "msg.usage", ownName);
        }
    }

    private final OptionHelper apiHelper = new GrumpyHelper(null) {
        @Override
        public String get(Option option) {
            return options.get(option);
        }

        @Override
        public void put(String name, String value) {
            options.put(name, value);
        }

        @Override
        public void remove(String name) {
            options.remove(name);
        }

        @Override
        public Log getLog() {
            return Arguments.this.log;
        }
    };

    
Initializes this Args instance with the parameters for a JavacTask.
The options will be processed in conjunction with the restricted set
of tool options, which does not include -help, -version, etc,
nor does it include classes and filenames, which should be specified
separately.
File manager options are handled directly by the file manager.
Any errors found while processing individual args will be reported
via IllegalArgumentException.
Any subsequent errors during validate will be reported via IllegalStateException.
Params:
ownName – the name of this tool; used to prefix messages
options – the options to be processed
classNames – the classes to be subject to annotation processing
files – the files to be compiled/**
     * Initializes this Args instance with the parameters for a JavacTask.
     * The options will be processed in conjunction with the restricted set
     * of tool options, which does not include -help, -version, etc,
     * nor does it include classes and filenames, which should be specified
     * separately.
     * File manager options are handled directly by the file manager.
     * Any errors found while processing individual args will be reported
     * via IllegalArgumentException.
     * Any subsequent errors during validate will be reported via IllegalStateException.
     * @param ownName the name of this tool; used to prefix messages
     * @param options the options to be processed
     * @param classNames the classes to be subject to annotation processing
     * @param files the files to be compiled
     */
    public void init(String ownName,
            Iterable<String> options,
            Iterable<String> classNames,
            Iterable<? extends JavaFileObject> files) {
        this.ownName = ownName;
        this.classNames = toSet(classNames);
        this.fileObjects = toSet(files);
        this.files = null;
        errorMode = ErrorMode.ILLEGAL_ARGUMENT;
        if (options != null) {
            processArgs(toList(options), Option.getJavacToolOptions(), apiHelper, false, true);
        }
        errorMode = ErrorMode.ILLEGAL_STATE;
    }

    
Minimal initialization for tools, like javadoc,
to be able to process javac options for themselves,
and then call validate.
Params:
ownName –  the name of this tool; used to prefix messages/**
     * Minimal initialization for tools, like javadoc,
     * to be able to process javac options for themselves,
     * and then call validate.
     * @param ownName  the name of this tool; used to prefix messages
     */
    public void init(String ownName) {
        this.ownName = ownName;
        errorMode = ErrorMode.LOG;
    }

    
Gets the files to be compiled.
Returns:
the files to be compiled/**
     * Gets the files to be compiled.
     * @return the files to be compiled
     */
    public Set<JavaFileObject> getFileObjects() {
        if (fileObjects == null) {
            fileObjects = new LinkedHashSet<>();
        }
        if (files != null) {
            JavacFileManager jfm = (JavacFileManager) getFileManager();
            for (JavaFileObject fo: jfm.getJavaFileObjectsFromPaths(files))
                fileObjects.add(fo);
        }
        return fileObjects;
    }

    
Gets the classes to be subject to annotation processing.
Returns:
the classes to be subject to annotation processing/**
     * Gets the classes to be subject to annotation processing.
     * @return the classes to be subject to annotation processing
     */
    public Set<String> getClassNames() {
        return classNames;
    }

    
Handles the --release option. 
Params:
additionalOptions – a predicate to handle additional options implied by the --release option. The predicate should return true if all the additional options were processed successfully.
Returns:
true if successful, false otherwise/**
     * Handles the {@code --release} option.
     *
     * @param additionalOptions a predicate to handle additional options implied by the
     * {@code --release} option. The predicate should return true if all the additional
     * options were processed successfully.
     * @return true if successful, false otherwise
     */
    public boolean handleReleaseOptions(Predicate<Iterable<String>> additionalOptions) {
        String platformString = options.get(Option.RELEASE);

        checkOptionAllowed(platformString == null,
                option -> reportDiag(Errors.ReleaseBootclasspathConflict(option)),
                Option.BOOT_CLASS_PATH, Option.XBOOTCLASSPATH, Option.XBOOTCLASSPATH_APPEND,
                Option.XBOOTCLASSPATH_PREPEND,
                Option.ENDORSEDDIRS, Option.DJAVA_ENDORSED_DIRS,
                Option.EXTDIRS, Option.DJAVA_EXT_DIRS,
                Option.SOURCE, Option.TARGET,
                Option.SYSTEM, Option.UPGRADE_MODULE_PATH);

        if (platformString != null) {
            PlatformDescription platformDescription =
                    PlatformUtils.lookupPlatformDescription(platformString);

            if (platformDescription == null) {
                reportDiag(Errors.UnsupportedReleaseVersion(platformString));
                return false;
            }

            options.put(Option.SOURCE, platformDescription.getSourceVersion());
            options.put(Option.TARGET, platformDescription.getTargetVersion());

            context.put(PlatformDescription.class, platformDescription);

            if (!additionalOptions.test(platformDescription.getAdditionalOptions()))
                return false;

            JavaFileManager platformFM = platformDescription.getFileManager();
            DelegatingJavaFileManager.installReleaseFileManager(context,
                                                                platformFM,
                                                                getFileManager());
        }

        return true;
    }

    
Processes strings containing options and operands.
Params:
args – the strings to be processed
allowableOpts – the set of option declarations that are applicable
helper – a help for use by Option.process
allowOperands – whether or not to check for files and classes
checkFileManager – whether or not to check if the file manager can handle
     options which are not recognized by any of allowableOpts
Throws:
IllegalArgumentException – if a problem occurs and errorMode is set to
     ILLEGAL_ARGUMENT
Returns:
true if all the strings were successfully processed; false otherwise/**
     * Processes strings containing options and operands.
     * @param args the strings to be processed
     * @param allowableOpts the set of option declarations that are applicable
     * @param helper a help for use by Option.process
     * @param allowOperands whether or not to check for files and classes
     * @param checkFileManager whether or not to check if the file manager can handle
     *      options which are not recognized by any of allowableOpts
     * @return true if all the strings were successfully processed; false otherwise
     * @throws IllegalArgumentException if a problem occurs and errorMode is set to
     *      ILLEGAL_ARGUMENT
     */
    private boolean processArgs(Iterable<String> args,
            Set<Option> allowableOpts, OptionHelper helper,
            boolean allowOperands, boolean checkFileManager) {
        if (!doProcessArgs(args, allowableOpts, helper, allowOperands, checkFileManager))
            return false;

        if (!handleReleaseOptions(extra -> doProcessArgs(extra, allowableOpts, helper, allowOperands, checkFileManager)))
            return false;

        options.notifyListeners();

        return true;
    }

    private boolean doProcessArgs(Iterable<String> args,
            Set<Option> allowableOpts, OptionHelper helper,
            boolean allowOperands, boolean checkFileManager) {
        JavaFileManager fm = checkFileManager ? getFileManager() : null;
        Iterator<String> argIter = args.iterator();
        while (argIter.hasNext()) {
            String arg = argIter.next();
            if (arg.isEmpty()) {
                reportDiag(Errors.InvalidFlag(arg));
                return false;
            }

            Option option = null;

            // first, check the provided set of javac options
            if (arg.startsWith("-")) {
                option = Option.lookup(arg, allowableOpts);
            } else if (allowOperands && Option.SOURCEFILE.matches(arg)) {
                option = Option.SOURCEFILE;
            }

            if (option != null) {
                try {
                    option.handleOption(helper, arg, argIter);
                } catch (Option.InvalidValueException e) {
                    error(e);
                    return false;
                }
                continue;
            }

            // check file manager option
            if (fm != null && fm.handleOption(arg, argIter)) {
                continue;
            }

            // none of the above
            reportDiag(Errors.InvalidFlag(arg));
            return false;
        }

        return true;
    }

    
Validates the overall consistency of the options and operands
processed by processOptions.
Throws:
IllegalStateException – if a problem is found and errorMode is set to
     ILLEGAL_STATE
Returns:
true if all args are successfully validated; false otherwise./**
     * Validates the overall consistency of the options and operands
     * processed by processOptions.
     * @return true if all args are successfully validated; false otherwise.
     * @throws IllegalStateException if a problem is found and errorMode is set to
     *      ILLEGAL_STATE
     */
    public boolean validate() {
        JavaFileManager fm = getFileManager();
        if (options.isSet(Option.MODULE)) {
            if (!fm.hasLocation(StandardLocation.CLASS_OUTPUT)) {
                log.error(Errors.OutputDirMustBeSpecifiedWithDashMOption);
            } else if (!fm.hasLocation(StandardLocation.MODULE_SOURCE_PATH)) {
                log.error(Errors.ModulesourcepathMustBeSpecifiedWithDashMOption);
            } else {
                java.util.List<String> modules = Arrays.asList(options.get(Option.MODULE).split(","));
                try {
                    for (String module : modules) {
                        Location sourceLoc = fm.getLocationForModule(StandardLocation.MODULE_SOURCE_PATH, module);
                        if (sourceLoc == null) {
                            log.error(Errors.ModuleNotFoundInModuleSourcePath(module));
                        } else {
                            Location classLoc = fm.getLocationForModule(StandardLocation.CLASS_OUTPUT, module);

                            for (JavaFileObject file : fm.list(sourceLoc, "", EnumSet.of(JavaFileObject.Kind.SOURCE), true)) {
                                String className = fm.inferBinaryName(sourceLoc, file);
                                JavaFileObject classFile = fm.getJavaFileForInput(classLoc, className, Kind.CLASS);

                                if (classFile == null || classFile.getLastModified() < file.getLastModified()) {
                                    if (fileObjects == null)
                                        fileObjects = new HashSet<>();
                                    fileObjects.add(file);
                                }
                            }
                        }
                    }
                } catch (IOException ex) {
                    log.printLines(PrefixKind.JAVAC, "msg.io");
                    ex.printStackTrace(log.getWriter(WriterKind.NOTICE));
                    return false;
                }
            }
        }

        if (isEmpty()) {
            // It is allowed to compile nothing if just asking for help or version info.
            // But also note that none of these options are supported in API mode.
            if (options.isSet(Option.HELP)
                    || options.isSet(Option.X)
                    || options.isSet(Option.VERSION)
                    || options.isSet(Option.FULLVERSION)
                    || options.isSet(Option.MODULE)) {
                return true;
            }

            if (!emptyAllowed) {
                if (!errors) {
                    if (JavaCompiler.explicitAnnotationProcessingRequested(options)) {
                        reportDiag(Errors.NoSourceFilesClasses);
                    } else {
                        reportDiag(Errors.NoSourceFiles);
                    }
                }
                return false;
            }
        }

        if (!checkDirectory(Option.D)) {
            return false;
        }
        if (!checkDirectory(Option.S)) {
            return false;
        }
        if (!checkDirectory(Option.H)) {
            return false;
        }

        // The following checks are to help avoid accidental confusion between
        // directories of modules and exploded module directories.
        if (fm instanceof StandardJavaFileManager) {
            StandardJavaFileManager sfm = (StandardJavaFileManager) fileManager;
            if (sfm.hasLocation(StandardLocation.CLASS_OUTPUT)) {
                Path outDir = sfm.getLocationAsPaths(StandardLocation.CLASS_OUTPUT).iterator().next();
                if (sfm.hasLocation(StandardLocation.MODULE_SOURCE_PATH)) {
                    // multi-module mode
                    if (Files.exists(outDir.resolve("module-info.class"))) {
                        log.error(Errors.MultiModuleOutdirCannotBeExplodedModule(outDir));
                    }
                } else {
                    // single-module or legacy mode
                    boolean lintPaths = options.isUnset(Option.XLINT_CUSTOM,
                            "-" + LintCategory.PATH.option);
                    if (lintPaths) {
                        Path outDirParent = outDir.getParent();
                        if (outDirParent != null && Files.exists(outDirParent.resolve("module-info.class"))) {
                            log.warning(LintCategory.PATH, Warnings.OutdirIsInExplodedModule(outDir));
                        }
                    }
                }
            }
        }


        String sourceString = options.get(Option.SOURCE);
        Source source = (sourceString != null)
                ? Source.lookup(sourceString)
                : Source.DEFAULT;
        String targetString = options.get(Option.TARGET);
        Target target = (targetString != null)
                ? Target.lookup(targetString)
                : Target.DEFAULT;

        // We don't check source/target consistency for CLDC, as J2ME
        // profiles are not aligned with J2SE targets; moreover, a
        // single CLDC target may have many profiles.  In addition,
        // this is needed for the continued functioning of the JSR14
        // prototype.
        if (Character.isDigit(target.name.charAt(0))) {
            if (target.compareTo(source.requiredTarget()) < 0) {
                if (targetString != null) {
                    if (sourceString == null) {
                        reportDiag(Warnings.TargetDefaultSourceConflict(targetString, source.requiredTarget()));
                    } else {
                        reportDiag(Warnings.SourceTargetConflict(sourceString, source.requiredTarget()));
                    }
                    return false;
                } else {
                    target = source.requiredTarget();
                    options.put("-target", target.name);
                }
            }
        }

        if (options.isSet(Option.PREVIEW)) {
            if (sourceString == null) {
                //enable-preview must be used with explicit -source or --release
                report(Errors.PreviewWithoutSourceOrRelease);
                return false;
            } else if (source != Source.DEFAULT) {
                //enable-preview must be used with latest source version
                report(Errors.PreviewNotLatest(sourceString, Source.DEFAULT));
                return false;
            }
        }

        String profileString = options.get(Option.PROFILE);
        if (profileString != null) {
            Profile profile = Profile.lookup(profileString);
            if (target.compareTo(Target.JDK1_8) <= 0 && !profile.isValid(target)) {
                // note: -profile not permitted for target >= 9, so error (below) not warning (here)
                reportDiag(Warnings.ProfileTargetConflict(profile, target));
            }

            // This check is only effective in command line mode,
            // where the file manager options are added to options
            if (options.get(Option.BOOT_CLASS_PATH) != null) {
                reportDiag(Errors.ProfileBootclasspathConflict);
            }
        }

        if (options.isSet(Option.SOURCE_PATH) && options.isSet(Option.MODULE_SOURCE_PATH)) {
            reportDiag(Errors.SourcepathModulesourcepathConflict);
        }

        boolean lintOptions = options.isUnset(Option.XLINT_CUSTOM, "-" + LintCategory.OPTIONS.option);
        if (lintOptions && source.compareTo(Source.DEFAULT) < 0 && !options.isSet(Option.RELEASE)) {
            if (fm instanceof BaseFileManager) {
                if (source.compareTo(Source.JDK8) <= 0) {
                    if (((BaseFileManager) fm).isDefaultBootClassPath())
                        log.warning(LintCategory.OPTIONS, Warnings.SourceNoBootclasspath(source.name));
                } else {
                    if (((BaseFileManager) fm).isDefaultSystemModulesPath())
                        log.warning(LintCategory.OPTIONS, Warnings.SourceNoSystemModulesPath(source.name));
                }
            }
        }

        boolean obsoleteOptionFound = false;

        if (source.compareTo(Source.MIN) < 0) {
            log.error(Errors.OptionRemovedSource(source.name, Source.MIN.name));
        } else if (source == Source.MIN && lintOptions) {
            log.warning(LintCategory.OPTIONS, Warnings.OptionObsoleteSource(source.name));
            obsoleteOptionFound = true;
        }

        if (target.compareTo(Target.MIN) < 0) {
            log.error(Errors.OptionRemovedTarget(target, Target.MIN));
        } else if (target == Target.MIN && lintOptions) {
            log.warning(LintCategory.OPTIONS, Warnings.OptionObsoleteTarget(target));
            obsoleteOptionFound = true;
        }

        final Target t = target;
        checkOptionAllowed(t.compareTo(Target.JDK1_8) <= 0,
                option -> reportDiag(Errors.OptionNotAllowedWithTarget(option, t)),
                Option.BOOT_CLASS_PATH,
                Option.XBOOTCLASSPATH_PREPEND, Option.XBOOTCLASSPATH, Option.XBOOTCLASSPATH_APPEND,
                Option.ENDORSEDDIRS, Option.DJAVA_ENDORSED_DIRS,
                Option.EXTDIRS, Option.DJAVA_EXT_DIRS,
                Option.PROFILE);

        checkOptionAllowed(t.compareTo(Target.JDK1_9) >= 0,
                option -> reportDiag(Errors.OptionNotAllowedWithTarget(option, t)),
                Option.MODULE_SOURCE_PATH, Option.UPGRADE_MODULE_PATH,
                Option.SYSTEM, Option.MODULE_PATH, Option.ADD_MODULES,
                Option.ADD_EXPORTS, Option.ADD_OPENS, Option.ADD_READS,
                Option.LIMIT_MODULES,
                Option.PATCH_MODULE);

        if (lintOptions && options.isSet(Option.PARAMETERS) && !target.hasMethodParameters()) {
            log.warning(Warnings.OptionParametersUnsupported(target, Target.JDK1_8));
        }

        if (fm.hasLocation(StandardLocation.MODULE_SOURCE_PATH)) {
            if (!options.isSet(Option.PROC, "only")
                    && !fm.hasLocation(StandardLocation.CLASS_OUTPUT)) {
                log.error(Errors.NoOutputDir);
            }
        }

        if (fm.hasLocation(StandardLocation.ANNOTATION_PROCESSOR_MODULE_PATH) &&
            fm.hasLocation(StandardLocation.ANNOTATION_PROCESSOR_PATH)) {
            log.error(Errors.ProcessorpathNoProcessormodulepath);
        }

        if (obsoleteOptionFound && lintOptions) {
            log.warning(LintCategory.OPTIONS, Warnings.OptionObsoleteSuppression);
        }

        SourceVersion sv = Source.toSourceVersion(source);
        validateAddExports(sv);
        validateAddModules(sv);
        validateAddReads(sv);
        validateLimitModules(sv);
        validateDefaultModuleForCreatedFiles(sv);

        if (lintOptions && options.isSet(Option.ADD_OPENS)) {
            log.warning(LintCategory.OPTIONS, Warnings.AddopensIgnored);
        }

        return !errors && (log.nerrors == 0);
    }

    private void validateAddExports(SourceVersion sv) {
        String addExports = options.get(Option.ADD_EXPORTS);
        if (addExports != null) {
            // Each entry must be of the form sourceModule/sourcePackage=target-list where
            // target-list is a comma separated list of module or ALL-UNNAMED.
            // Empty items in the target-list are ignored.
            // There must be at least one item in the list; this is handled in Option.ADD_EXPORTS.
            Pattern p = Option.ADD_EXPORTS.getPattern();
            for (String e : addExports.split("\0")) {
                Matcher m = p.matcher(e);
                if (m.matches()) {
                    String sourceModuleName = m.group(1);
                    if (!SourceVersion.isName(sourceModuleName, sv)) {
                        // syntactically invalid source name:  e.g. --add-exports m!/p1=m2
                        log.warning(Warnings.BadNameForOption(Option.ADD_EXPORTS, sourceModuleName));
                    }
                    String sourcePackageName = m.group(2);
                    if (!SourceVersion.isName(sourcePackageName, sv)) {
                        // syntactically invalid source name:  e.g. --add-exports m1/p!=m2
                        log.warning(Warnings.BadNameForOption(Option.ADD_EXPORTS, sourcePackageName));
                    }

                    String targetNames = m.group(3);
                    for (String targetName : targetNames.split(",")) {
                        switch (targetName) {
                            case "":
                            case "ALL-UNNAMED":
                                break;

                            default:
                                if (!SourceVersion.isName(targetName, sv)) {
                                    // syntactically invalid target name:  e.g. --add-exports m1/p1=m!
                                    log.warning(Warnings.BadNameForOption(Option.ADD_EXPORTS, targetName));
                                }
                                break;
                        }
                    }
                }
            }
        }
    }

    private void validateAddReads(SourceVersion sv) {
        String addReads = options.get(Option.ADD_READS);
        if (addReads != null) {
            // Each entry must be of the form source=target-list where target-list is a
            // comma-separated list of module or ALL-UNNAMED.
            // Empty items in the target list are ignored.
            // There must be at least one item in the list; this is handled in Option.ADD_READS.
            Pattern p = Option.ADD_READS.getPattern();
            for (String e : addReads.split("\0")) {
                Matcher m = p.matcher(e);
                if (m.matches()) {
                    String sourceName = m.group(1);
                    if (!SourceVersion.isName(sourceName, sv)) {
                        // syntactically invalid source name:  e.g. --add-reads m!=m2
                        log.warning(Warnings.BadNameForOption(Option.ADD_READS, sourceName));
                    }

                    String targetNames = m.group(2);
                    for (String targetName : targetNames.split(",", -1)) {
                        switch (targetName) {
                            case "":
                            case "ALL-UNNAMED":
                                break;

                            default:
                                if (!SourceVersion.isName(targetName, sv)) {
                                    // syntactically invalid target name:  e.g. --add-reads m1=m!
                                    log.warning(Warnings.BadNameForOption(Option.ADD_READS, targetName));
                                }
                                break;
                        }
                    }
                }
            }
        }
    }

    private void validateAddModules(SourceVersion sv) {
        String addModules = options.get(Option.ADD_MODULES);
        if (addModules != null) {
            // Each entry must be of the form target-list where target-list is a
            // comma separated list of module names, or ALL-DEFAULT, ALL-SYSTEM,
            // or ALL-MODULE_PATH.
            // Empty items in the target list are ignored.
            // There must be at least one item in the list; this is handled in Option.ADD_MODULES.
            for (String moduleName : addModules.split(",")) {
                switch (moduleName) {
                    case "":
                    case "ALL-SYSTEM":
                    case "ALL-MODULE-PATH":
                        break;

                    default:
                        if (!SourceVersion.isName(moduleName, sv)) {
                            // syntactically invalid module name:  e.g. --add-modules m1,m!
                            log.error(Errors.BadNameForOption(Option.ADD_MODULES, moduleName));
                        }
                        break;
                }
            }
        }
    }

    private void validateLimitModules(SourceVersion sv) {
        String limitModules = options.get(Option.LIMIT_MODULES);
        if (limitModules != null) {
            // Each entry must be of the form target-list where target-list is a
            // comma separated list of module names, or ALL-DEFAULT, ALL-SYSTEM,
            // or ALL-MODULE_PATH.
            // Empty items in the target list are ignored.
            // There must be at least one item in the list; this is handled in Option.LIMIT_EXPORTS.
            for (String moduleName : limitModules.split(",")) {
                switch (moduleName) {
                    case "":
                        break;

                    default:
                        if (!SourceVersion.isName(moduleName, sv)) {
                            // syntactically invalid module name:  e.g. --limit-modules m1,m!
                            log.error(Errors.BadNameForOption(Option.LIMIT_MODULES, moduleName));
                        }
                        break;
                }
            }
        }
    }

    private void validateDefaultModuleForCreatedFiles(SourceVersion sv) {
        String moduleName = options.get(Option.DEFAULT_MODULE_FOR_CREATED_FILES);
        if (moduleName != null) {
            if (!SourceVersion.isName(moduleName, sv)) {
                // syntactically invalid module name:  e.g. --default-module-for-created-files m!
                log.error(Errors.BadNameForOption(Option.DEFAULT_MODULE_FOR_CREATED_FILES,
                                                  moduleName));
            }
        }
    }

    
Returns true if there are no files or classes specified for use.
Returns:
true if there are no files or classes specified for use/**
     * Returns true if there are no files or classes specified for use.
     * @return true if there are no files or classes specified for use
     */
    public boolean isEmpty() {
        return ((files == null) || files.isEmpty())
                && ((fileObjects == null) || fileObjects.isEmpty())
                && (classNames == null || classNames.isEmpty());
    }

    public void allowEmpty() {
        this.emptyAllowed = true;
    }

    
Gets the file manager options which may have been deferred
during processArgs.
Returns:
the deferred file manager options/**
     * Gets the file manager options which may have been deferred
     * during processArgs.
     * @return the deferred file manager options
     */
    public Map<Option, String> getDeferredFileManagerOptions() {
        return deferredFileManagerOptions;
    }

    
Gets any options specifying plugins to be run.
Returns:
options for plugins/**
     * Gets any options specifying plugins to be run.
     * @return options for plugins
     */
    public Set<List<String>> getPluginOpts() {
        String plugins = options.get(Option.PLUGIN);
        if (plugins == null)
            return Collections.emptySet();

        Set<List<String>> pluginOpts = new LinkedHashSet<>();
        for (String plugin: plugins.split("\\x00")) {
            pluginOpts.add(List.from(plugin.split("\\s+")));
        }
        return Collections.unmodifiableSet(pluginOpts);
    }

    
Gets any options specifying how doclint should be run.
An empty list is returned if no doclint options are specified
or if the only doclint option is -Xdoclint:none.
Returns:
options for doclint/**
     * Gets any options specifying how doclint should be run.
     * An empty list is returned if no doclint options are specified
     * or if the only doclint option is -Xdoclint:none.
     * @return options for doclint
     */
    public List<String> getDocLintOpts() {
        String xdoclint = options.get(Option.XDOCLINT);
        String xdoclintCustom = options.get(Option.XDOCLINT_CUSTOM);
        if (xdoclint == null && xdoclintCustom == null)
            return List.nil();

        Set<String> doclintOpts = new LinkedHashSet<>();
        if (xdoclint != null)
            doclintOpts.add(DocLint.XMSGS_OPTION);
        if (xdoclintCustom != null) {
            for (String s: xdoclintCustom.split("\\s+")) {
                if (s.isEmpty())
                    continue;
                doclintOpts.add(DocLint.XMSGS_CUSTOM_PREFIX + s);
            }
        }

        if (doclintOpts.equals(Collections.singleton(DocLint.XMSGS_CUSTOM_PREFIX + "none")))
            return List.nil();

        String checkPackages = options.get(Option.XDOCLINT_PACKAGE);
        if (checkPackages != null) {
            doclintOpts.add(DocLint.XCHECK_PACKAGE + checkPackages);
        }

        return List.from(doclintOpts.toArray(new String[doclintOpts.size()]));
    }

    private boolean checkDirectory(Option option) {
        String value = options.get(option);
        if (value == null) {
            return true;
        }
        Path file = Paths.get(value);
        if (Files.exists(file) && !Files.isDirectory(file)) {
            reportDiag(Errors.FileNotDirectory(value));
            return false;
        }
        return true;
    }

    private interface ErrorReporter {
        void report(Option o);
    }

    void checkOptionAllowed(boolean allowed, ErrorReporter r, Option... opts) {
        if (!allowed) {
            Stream.of(opts)
                  .filter(options :: isSet)
                  .forEach(r :: report);
        }
    }

    void reportDiag(DiagnosticInfo diag) {
        errors = true;
        switch (errorMode) {
            case ILLEGAL_ARGUMENT: {
                String msg = log.localize(diag);
                throw new PropagatedException(new IllegalArgumentException(msg));
            }
            case ILLEGAL_STATE: {
                String msg = log.localize(diag);
                throw new PropagatedException(new IllegalStateException(msg));
            }
            case LOG:
                report(diag);
        }
    }

    void error(Option.InvalidValueException f) {
        String msg = f.getMessage();
        errors = true;
        switch (errorMode) {
            case ILLEGAL_ARGUMENT: {
                throw new PropagatedException(new IllegalArgumentException(msg, f.getCause()));
            }
            case ILLEGAL_STATE: {
                throw new PropagatedException(new IllegalStateException(msg, f.getCause()));
            }
            case LOG:
                log.printRawLines(msg);
        }
    }

    private void report(DiagnosticInfo diag) {
        // Would be good to have support for -XDrawDiagnostics here
        if (diag instanceof JCDiagnostic.Error) {
            log.error((JCDiagnostic.Error)diag);
        } else if (diag instanceof JCDiagnostic.Warning){
            log.warning((JCDiagnostic.Warning)diag);
        }
    }

    private JavaFileManager getFileManager() {
        if (fileManager == null)
            fileManager = context.get(JavaFileManager.class);
        return fileManager;
    }

    <T> ListBuffer<T> toList(Iterable<? extends T> items) {
        ListBuffer<T> list = new ListBuffer<>();
        if (items != null) {
            for (T item : items) {
                list.add(item);
            }
        }
        return list;
    }

    <T> Set<T> toSet(Iterable<? extends T> items) {
        Set<T> set = new LinkedHashSet<>();
        if (items != null) {
            for (T item : items) {
                set.add(item);
            }
        }
        return set;
    }
}