langtools/src/jdk.javadoc/share/classes/jdk/javadoc/internal/tool/Start.java - platform/libcore - Gitiles

 /*
  * Copyright (c) 1997, 2016, 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 jdk.javadoc.internal.tool;

 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.lang.reflect.Method;
 import java.nio.file.Path;
 import java.text.BreakIterator;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
 import java.util.Objects;
 import java.util.Set;

 import static javax.tools.DocumentationTool.Location.*;

 import javax.tools.JavaFileManager;
 import javax.tools.JavaFileObject;
 import javax.tools.StandardJavaFileManager;
 import javax.tools.StandardLocation;

 import com.sun.tools.javac.api.JavacTrees;
 import com.sun.tools.javac.file.BaseFileManager;
 import com.sun.tools.javac.file.JavacFileManager;
 import com.sun.tools.javac.main.CommandLine;
 import com.sun.tools.javac.platform.PlatformDescription;
 import com.sun.tools.javac.platform.PlatformUtils;
 import com.sun.tools.javac.util.ClientCodeException;
 import com.sun.tools.javac.util.Context;
 import com.sun.tools.javac.util.Log;
 import com.sun.tools.javac.util.Options;

 import jdk.javadoc.doclet.Doclet;
 import jdk.javadoc.doclet.Doclet.Option;
 import jdk.javadoc.doclet.DocletEnvironment;

 import static com.sun.tools.javac.main.Option.*;
 /**
  * Main program of Javadoc.
  * Previously named "Main".
  *
  *  <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>
  *
  * @author Robert Field
  * @author Neal Gafter (rewrite)
  */
 public class Start extends ToolOption.Helper {
     /** Context for this invocation. */
     private final Context context;

     private static final String ProgramName = "javadoc";

     // meaning we allow all visibility of PROTECTED and PUBLIC
     private static final String defaultModifier = "protected";

     private Messager messager;

     private final String docletName;

     private final ClassLoader classLoader;

     private Class<?> docletClass;

     private Doclet doclet;

     // used to determine the locale for the messager
     private Locale locale;


     /**
      * In API mode, exceptions thrown while calling the doclet are
      * propagated using ClientCodeException.
      */
     private boolean apiMode;

     private JavaFileManager fileManager;

     Start() {
         this(null, null, null, null, null);
     }

     Start(PrintWriter writer) {
         this(null, null, writer, null, null);
     }

     Start(Context context, String programName, PrintWriter writer,
             String docletName, ClassLoader classLoader) {
         this.context = context == null ? new Context() : context;
         String pname = programName == null ? ProgramName : programName;
         this.messager = writer == null
                 ? new Messager(this.context, pname)
                 : new Messager(this.context, pname, writer, writer);
         this.docletName = docletName;
         this.classLoader = classLoader;
         this.docletClass = null;
         this.locale = Locale.getDefault();
     }

     public Start(Context context) {
         this.docletClass = null;
         this.context = Objects.requireNonNull(context);
         this.apiMode = true;
         this.docletName = null;
         this.classLoader = null;
         this.locale = Locale.getDefault();
     }

     void initMessager() {
         if (!apiMode)
             return;
         if (messager == null) {
             Log log = context.get(Log.logKey);
             if (log instanceof Messager) {
                 messager = (Messager) log;
             } else {
                 PrintWriter out = context.get(Log.outKey);
                 messager = (out == null)
                         ? new Messager(context, ProgramName)
                         : new Messager(context, ProgramName, out, out);
             }
         }
     }

     /**
      * Usage
      */
     @Override
     void usage() {
         usage(true);
     }

     void usage(boolean exit) {
         usage("main.usage", "-help", null, exit);
     }

     @Override
     void Xusage() {
         Xusage(true);
     }

     void Xusage(boolean exit) {
         usage("main.Xusage", "-X", "main.Xusage.foot", exit);
     }

     private void usage(String main, String option, String foot, boolean exit) {
         messager.notice(main);
         // let doclet print usage information (does nothing on error)
         if (docletClass != null) {
             String name = doclet.getName();
             Set<Option> supportedOptions = doclet.getSupportedOptions();
             messager.notice("main.doclet.usage.header", name);
             Option.Kind myKind = option.equals("-X")
                     ? Option.Kind.EXTENDED
                     : Option.Kind.STANDARD;
             supportedOptions.stream()
                     .filter(opt -> opt.getKind() == myKind)
                     .forEach(opt -> messager.printNotice(opt.toString()));
         }
         if (foot != null)
             messager.notice(foot);

         if (exit) exit();
     }

     /**
      * Exit
      */
     private void exit() {
         messager.exit();
     }

     /**
      * Main program - external wrapper
      */
     int begin(String... argv) {
         // Preprocess @file arguments
         try {
             argv = CommandLine.parse(argv);
         } catch (FileNotFoundException e) {
             messager.error("main.cant.read", e.getMessage());
             exit();
         } catch (IOException e) {
             e.printStackTrace(System.err);
             exit();
         }

         List<String> argList = Arrays.asList(argv);
         boolean ok = begin(argList, Collections.<JavaFileObject> emptySet());
         return ok ? 0 : 1;
     }

     // Called by 199 API.
     public boolean begin(Class<?> docletClass,
             Iterable<String> options,
             Iterable<? extends JavaFileObject> fileObjects) {
         this.docletClass = docletClass;
         List<String> opts = new ArrayList<>();
         for (String opt: options)
             opts.add(opt);
         return begin(opts, fileObjects);
     }

     private boolean begin(List<String> options, Iterable<? extends JavaFileObject> fileObjects) {

         fileManager = context.get(JavaFileManager.class);
         if (fileManager == null) {
             JavacFileManager.preRegister(context);
             fileManager = context.get(JavaFileManager.class);
             if (fileManager instanceof BaseFileManager) {
                 ((BaseFileManager) fileManager).autoClose = true;
             }
         }
         // locale and doclet needs to be determined first
         docletClass = preProcess(fileManager, options);

         if (jdk.javadoc.doclet.Doclet.class.isAssignableFrom(docletClass)) {
             // no need to dispatch to old, safe to init now
             initMessager();
             messager.setLocale(locale);
             try {
                 doclet = (Doclet) docletClass.newInstance();
             } catch (InstantiationException | IllegalAccessException exc) {
                 exc.printStackTrace();
                 if (!apiMode) {
                     error("main.could_not_instantiate_class", docletClass);
                     messager.exit();
                 }
                 throw new ClientCodeException(exc);
             }
         } else {
             if (this.apiMode) {
                 com.sun.tools.javadoc.Start ostart
                         = new com.sun.tools.javadoc.Start(context);
                 return ostart.begin(docletClass, options, fileObjects);
             }
             String[] array = options.toArray(new String[options.size()]);
             return com.sun.tools.javadoc.Main.execute(array) == 0;
         }

         boolean failed = false;
         try {
             failed = !parseAndExecute(options, fileObjects);
         } catch (Messager.ExitJavadoc exc) {
             // ignore, we just exit this way
         } catch (OutOfMemoryError ee) {
             messager.error("main.out.of.memory");
             failed = true;
         } catch (ClientCodeException e) {
             // simply rethrow these exceptions, to be caught and handled by JavadocTaskImpl
             throw e;
         } catch (Error ee) {
             ee.printStackTrace(System.err);
             messager.error("main.fatal.error");
             failed = true;
         } catch (Exception ee) {
             ee.printStackTrace(System.err);
             messager.error("main.fatal.exception");
             failed = true;
         } finally {
             if (fileManager != null
                     && fileManager instanceof BaseFileManager
                     && ((BaseFileManager) fileManager).autoClose) {
                 try {
                     fileManager.close();
                 } catch (IOException ignore) {}
             }
             boolean haveErrorWarnings = messager.nerrors() > 0 ||
                     (rejectWarnings && messager.nwarnings() > 0);
             if (failed && !haveErrorWarnings) {
                 // the doclet failed, but nothing reported, flag it!.
                 messager.error("main.unknown.error");
             }
             failed |= haveErrorWarnings;
             messager.exitNotice();
             messager.flush();
         }
         return !failed;
     }

     /**
      * Ensures that the module of the given class is readable to this
      * module.
      * @param targetClass class in module to be made readable
      */
     private void ensureReadable(Class<?> targetClass) {
         try {
             Method getModuleMethod = Class.class.getMethod("getModule");
             Object thisModule = getModuleMethod.invoke(this.getClass());
             Object targetModule = getModuleMethod.invoke(targetClass);

             Class<?> moduleClass = getModuleMethod.getReturnType();
             Method addReadsMethod = moduleClass.getMethod("addReads", moduleClass);
             addReadsMethod.invoke(thisModule, targetModule);
         } catch (NoSuchMethodException e) {
             // ignore
         } catch (Exception e) {
             throw new InternalError(e);
         }
     }

     /**
      * Main program - internal
      */
     private boolean parseAndExecute(List<String> argList,
             Iterable<? extends JavaFileObject> fileObjects) throws IOException {
         long tm = System.currentTimeMillis();

         List<String> javaNames = new ArrayList<>();

         compOpts = Options.instance(context);

         // Make sure no obsolete source/target messages are reported
         compOpts.put("-Xlint:-options", "-Xlint:-options");

         doclet.init(locale, messager);
         parseArgs(argList, javaNames);

         if (fileManager instanceof BaseFileManager) {
             ((BaseFileManager) fileManager).handleOptions(fileManagerOpts);
         }

         String platformString = compOpts.get("-release");

         if (platformString != null) {
             if (compOpts.isSet("-source")) {
                 usageError("main.release.bootclasspath.conflict", "-source");
             }
             if (fileManagerOpts.containsKey(BOOTCLASSPATH)) {
                 usageError("main.release.bootclasspath.conflict", BOOTCLASSPATH.getText());
             }

             PlatformDescription platformDescription =
                     PlatformUtils.lookupPlatformDescription(platformString);

             if (platformDescription == null) {
                 usageError("main.unsupported.release.version", platformString);
             }

             compOpts.put(SOURCE, platformDescription.getSourceVersion());

             context.put(PlatformDescription.class, platformDescription);

             Collection<Path> platformCP = platformDescription.getPlatformPath();

             if (platformCP != null) {
                 if (fileManager instanceof StandardJavaFileManager) {
                     StandardJavaFileManager sfm = (StandardJavaFileManager) fileManager;

                     sfm.setLocationFromPaths(StandardLocation.PLATFORM_CLASS_PATH, platformCP);
                 } else {
                     usageError("main.release.not.standard.file.manager", platformString);
                 }
             }
         }

         compOpts.notifyListeners();

         if (javaNames.isEmpty() && subPackages.isEmpty() && isEmpty(fileObjects)) {
             usageError("main.No_packages_or_classes_specified");
         }

         JavadocTool comp = JavadocTool.make0(context);
         if (comp == null) return false;

         if (showAccess == null) {
             setFilter(defaultModifier);
         }

         DocletEnvironment root = comp.getEnvironment(
                 encoding,
                 showAccess,
                 overviewpath,
                 javaNames,
                 fileObjects,
                 subPackages,
                 excludedPackages,
                 docClasses,
                 quiet);

         // release resources
         comp = null;

         if (breakiterator || !locale.getLanguage().equals(Locale.ENGLISH.getLanguage())) {
             JavacTrees trees = JavacTrees.instance(context);
             trees.setBreakIterator(BreakIterator.getSentenceInstance(locale));
         }
         // pass off control to the doclet
         boolean ok = root != null;
         if (ok) ok = doclet.run(root);

         // We're done.
         if (compOpts.get("-verbose") != null) {
             tm = System.currentTimeMillis() - tm;
             messager.notice("main.done_in", Long.toString(tm));
         }

         return ok;
     }

     Set<Doclet.Option> docletOptions = null;
     int handleDocletOptions(int idx, List<String> args, boolean isToolOption) {
         if (docletOptions == null) {
             docletOptions = doclet.getSupportedOptions();
         }
         String arg = args.get(idx);

         for (Doclet.Option opt : docletOptions) {
             if (opt.matches(arg)) {
                 if (args.size() - idx < opt.getArgumentCount()) {
                     usageError("main.requires_argument", arg);
                 }
                 opt.process(arg, args.listIterator(idx + 1));
                 idx += opt.getArgumentCount();
                 return idx;
             }
         }
         // check if arg is accepted by the tool before emitting error
         if (!isToolOption)
             usageError("main.invalid_flag", arg);
         return idx;
     }

     private Class<?> preProcess(JavaFileManager jfm, List<String> argv) {
         // doclet specifying arguments
         String userDocletPath = null;
         String userDocletName = null;

         // Step 1: loop through the args, set locale early on, if found.
         for (int i = 0 ; i < argv.size() ; i++) {
             String arg = argv.get(i);
             if (arg.equals(ToolOption.LOCALE.opt)) {
                 oneArg(argv, i++);
                 String lname = argv.get(i);
                 locale = getLocale(lname);
             } else if (arg.equals(ToolOption.DOCLET.opt)) {
                 oneArg(argv, i++);
                 if (userDocletName != null) {
                     usageError("main.more_than_one_doclet_specified_0_and_1",
                                userDocletName, argv.get(i));
                 }
                 if (docletName != null) {
                     usageError("main.more_than_one_doclet_specified_0_and_1",
                             docletName, argv.get(i));
                 }
                 userDocletName = argv.get(i);
             } else if (arg.equals(ToolOption.DOCLETPATH.opt)) {
                 oneArg(argv, i++);
                 if (userDocletPath == null) {
                     userDocletPath = argv.get(i);
                 } else {
                     userDocletPath += File.pathSeparator + argv.get(i);
                 }
             }
         }
         // Step 2: a doclet has already been provided,
         // nothing more to do.
         if (docletClass != null) {
             return docletClass;
         }
         // Step 3: doclet name specified ? if so find a ClassLoader,
         // and load it.
         if (userDocletName != null) {
             ClassLoader cl = classLoader;
             if (cl == null) {
                 if (!fileManager.hasLocation(DOCLET_PATH)) {
                     List<File> paths = new ArrayList<>();
                     if (userDocletPath != null) {
                         for (String pathname : userDocletPath.split(File.pathSeparator)) {
                             paths.add(new File(pathname));
                         }
                     }
                     try {
                         ((StandardJavaFileManager)fileManager).setLocation(DOCLET_PATH, paths);
                     } catch (IOException ioe) {
                         panic("main.doclet_no_classloader_found", ioe);
                         return null; // keep compiler happy
                     }
                 }
                 cl = fileManager.getClassLoader(DOCLET_PATH);
                 if (cl == null) {
                     // despite doclet specified on cmdline no classloader found!
                     panic("main.doclet_no_classloader_found", userDocletName);
                     return null; // keep compiler happy
                 }
                 try {
                     Class<?> klass = cl.loadClass(userDocletName);
                     ensureReadable(klass);
                     return klass;
                 } catch (ClassNotFoundException cnfe) {
                     panic("main.doclet_class_not_found", userDocletName);
                     return null; // keep compiler happy
                 }
             }
         }
         // Step 4: we have a doclet, try loading it, otherwise
         // return back the standard doclet
         if (docletName != null) {
             try {
                 return Class.forName(docletName, true, getClass().getClassLoader());
             } catch (ClassNotFoundException cnfe) {
                 panic("main.doclet_class_not_found", userDocletName);
                 return null; // happy compiler, should not happen
             }
         } else {
             return jdk.javadoc.internal.doclets.standard.Standard.class;
         }
     }

     private void parseArgs(List<String> args, List<String> javaNames) {
         for (int i = 0 ; i < args.size() ; i++) {
             String arg = args.get(i);
             ToolOption o = ToolOption.get(arg);
             if (o != null) {
                 // handle a doclet argument that may be needed however
                 // don't increment the index, and allow the tool to consume args
                 handleDocletOptions(i, args, true);

                 if (o.hasArg) {
                     oneArg(args, i++);
                     o.process(this, args.get(i));
                 } else {
                     setOption(arg);
                     o.process(this);
                 }
             } else if (arg.startsWith("-XD")) {
                 // hidden javac options
                 String s = arg.substring("-XD".length());
                 int eq = s.indexOf('=');
                 String key = (eq < 0) ? s : s.substring(0, eq);
                 String value = (eq < 0) ? s : s.substring(eq+1);
                 compOpts.put(key, value);
             } else if (arg.startsWith("-")) {
                 i = handleDocletOptions(i, args, false);
             } else {
                 javaNames.add(arg);
             }
         }
     }

     private <T> boolean isEmpty(Iterable<T> iter) {
         return !iter.iterator().hasNext();
     }

     /**
      * Set one arg option.
      * Error and exit if one argument is not provided.
      */
     private void oneArg(List<String> args, int index) {
         if ((index + 1) < args.size()) {
             setOption(args.get(index), args.get(index+1));
         } else {
             usageError("main.requires_argument", args.get(index));
         }
     }

     @Override
     void usageError(String key, Object... args) {
         error(key, args);
         usage(true);
     }

     // a terminal call, will not return
     void panic(String key, Object... args) {
         error(key, args);
         messager.exit();
     }

     void error(String key, Object... args) {
         messager.error(key, args);
     }

     /**
      * indicate an option with no arguments was given.
      */
     private void setOption(String opt) {
         String[] option = { opt };
         options.add(Arrays.asList(option));
     }

     /**
      * indicate an option with one argument was given.
      */
     private void setOption(String opt, String argument) {
         String[] option = { opt, argument };
         options.add(Arrays.asList(option));
     }

     /**
      * indicate an option with the specified list of arguments was given.
      */
     private void setOption(String opt, List<String> arguments) {
         List<String> args = new ArrayList<>(arguments.size() + 1);
         args.add(opt);
         args.addAll(arguments);
         options.add(args);
     }

     /**
      * Get the locale if specified on the command line
      * else return null and if locale option is not used
      * then return default locale.
      */
     private Locale getLocale(String localeName) {
         Locale userlocale = null;
         if (localeName == null || localeName.isEmpty()) {
             return Locale.getDefault();
         }
         int firstuscore = localeName.indexOf('_');
         int seconduscore = -1;
         String language = null;
         String country = null;
         String variant = null;
         if (firstuscore == 2) {
             language = localeName.substring(0, firstuscore);
             seconduscore = localeName.indexOf('_', firstuscore + 1);
             if (seconduscore > 0) {
                 if (seconduscore != firstuscore + 3
                         || localeName.length() <= seconduscore + 1) {
                     usageError("main.malformed_locale_name", localeName);
                     return null;
                 }
                 country = localeName.substring(firstuscore + 1,
                         seconduscore);
                 variant = localeName.substring(seconduscore + 1);
             } else if (localeName.length() == firstuscore + 3) {
                 country = localeName.substring(firstuscore + 1);
             } else {
                 usageError("main.malformed_locale_name", localeName);
                 return null;
             }
         } else if (firstuscore == -1 && localeName.length() == 2) {
             language = localeName;
         } else {
             usageError("main.malformed_locale_name", localeName);
             return null;
         }
         userlocale = searchLocale(language, country, variant);
         if (userlocale == null) {
             usageError("main.illegal_locale_name", localeName);
             return null;
         } else {
             return userlocale;
         }
     }

     /**
      * Search the locale for specified language, specified country and
      * specified variant.
      */
     private Locale searchLocale(String language, String country,
                                 String variant) {
         for (Locale loc : Locale.getAvailableLocales()) {
             if (loc.getLanguage().equals(language) &&
                 (country == null || loc.getCountry().equals(country)) &&
                 (variant == null || loc.getVariant().equals(variant))) {
                 return loc;
             }
         }
         return null;
     }
 }
	/*
	* Copyright (c) 1997, 2016, 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 jdk.javadoc.internal.tool;

	import java.io.File;
	import java.io.FileNotFoundException;
	import java.io.IOException;
	import java.io.PrintWriter;
	import java.lang.reflect.Method;
	import java.nio.file.Path;
	import java.text.BreakIterator;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.List;
	import java.util.Locale;
	import java.util.Objects;
	import java.util.Set;

	import static javax.tools.DocumentationTool.Location.*;

	import javax.tools.JavaFileManager;
	import javax.tools.JavaFileObject;
	import javax.tools.StandardJavaFileManager;
	import javax.tools.StandardLocation;

	import com.sun.tools.javac.api.JavacTrees;
	import com.sun.tools.javac.file.BaseFileManager;
	import com.sun.tools.javac.file.JavacFileManager;
	import com.sun.tools.javac.main.CommandLine;
	import com.sun.tools.javac.platform.PlatformDescription;
	import com.sun.tools.javac.platform.PlatformUtils;
	import com.sun.tools.javac.util.ClientCodeException;
	import com.sun.tools.javac.util.Context;
	import com.sun.tools.javac.util.Log;
	import com.sun.tools.javac.util.Options;

	import jdk.javadoc.doclet.Doclet;
	import jdk.javadoc.doclet.Doclet.Option;
	import jdk.javadoc.doclet.DocletEnvironment;

	import static com.sun.tools.javac.main.Option.*;
	/**
	* Main program of Javadoc.
	* Previously named "Main".
	*
	* <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>
	*
	* @author Robert Field
	* @author Neal Gafter (rewrite)
	*/
	public class Start extends ToolOption.Helper {
	/** Context for this invocation. */
	private final Context context;

	private static final String ProgramName = "javadoc";

	// meaning we allow all visibility of PROTECTED and PUBLIC
	private static final String defaultModifier = "protected";

	private Messager messager;

	private final String docletName;

	private final ClassLoader classLoader;

	private Class<?> docletClass;

	private Doclet doclet;

	// used to determine the locale for the messager
	private Locale locale;


	/**
	* In API mode, exceptions thrown while calling the doclet are
	* propagated using ClientCodeException.
	*/
	private boolean apiMode;

	private JavaFileManager fileManager;

	Start() {
	this(null, null, null, null, null);
	}

	Start(PrintWriter writer) {
	this(null, null, writer, null, null);
	}

	Start(Context context, String programName, PrintWriter writer,
	String docletName, ClassLoader classLoader) {
	this.context = context == null ? new Context() : context;
	String pname = programName == null ? ProgramName : programName;
	this.messager = writer == null
	? new Messager(this.context, pname)
	: new Messager(this.context, pname, writer, writer);
	this.docletName = docletName;
	this.classLoader = classLoader;
	this.docletClass = null;
	this.locale = Locale.getDefault();
	}

	public Start(Context context) {
	this.docletClass = null;
	this.context = Objects.requireNonNull(context);
	this.apiMode = true;
	this.docletName = null;
	this.classLoader = null;
	this.locale = Locale.getDefault();
	}

	void initMessager() {
	if (!apiMode)
	return;
	if (messager == null) {
	Log log = context.get(Log.logKey);
	if (log instanceof Messager) {
	messager = (Messager) log;
	} else {
	PrintWriter out = context.get(Log.outKey);
	messager = (out == null)
	? new Messager(context, ProgramName)
	: new Messager(context, ProgramName, out, out);
	}
	}
	}

	/**
	* Usage
	*/
	@Override
	void usage() {
	usage(true);
	}

	void usage(boolean exit) {
	usage("main.usage", "-help", null, exit);
	}

	@Override
	void Xusage() {
	Xusage(true);
	}

	void Xusage(boolean exit) {
	usage("main.Xusage", "-X", "main.Xusage.foot", exit);
	}

	private void usage(String main, String option, String foot, boolean exit) {
	messager.notice(main);
	// let doclet print usage information (does nothing on error)
	if (docletClass != null) {
	String name = doclet.getName();
	Set<Option> supportedOptions = doclet.getSupportedOptions();
	messager.notice("main.doclet.usage.header", name);
	Option.Kind myKind = option.equals("-X")
	? Option.Kind.EXTENDED
	: Option.Kind.STANDARD;
	supportedOptions.stream()
	.filter(opt -> opt.getKind() == myKind)
	.forEach(opt -> messager.printNotice(opt.toString()));
	}
	if (foot != null)
	messager.notice(foot);

	if (exit) exit();
	}

	/**
	* Exit
	*/
	private void exit() {
	messager.exit();
	}

	/**
	* Main program - external wrapper
	*/
	int begin(String... argv) {
	// Preprocess @file arguments
	try {
	argv = CommandLine.parse(argv);
	} catch (FileNotFoundException e) {
	messager.error("main.cant.read", e.getMessage());
	exit();
	} catch (IOException e) {
	e.printStackTrace(System.err);
	exit();
	}

	List<String> argList = Arrays.asList(argv);
	boolean ok = begin(argList, Collections.<JavaFileObject> emptySet());
	return ok ? 0 : 1;
	}

	// Called by 199 API.
	public boolean begin(Class<?> docletClass,
	Iterable<String> options,
	Iterable<? extends JavaFileObject> fileObjects) {
	this.docletClass = docletClass;
	List<String> opts = new ArrayList<>();
	for (String opt: options)
	opts.add(opt);
	return begin(opts, fileObjects);
	}

	private boolean begin(List<String> options, Iterable<? extends JavaFileObject> fileObjects) {

	fileManager = context.get(JavaFileManager.class);
	if (fileManager == null) {
	JavacFileManager.preRegister(context);
	fileManager = context.get(JavaFileManager.class);
	if (fileManager instanceof BaseFileManager) {
	((BaseFileManager) fileManager).autoClose = true;
	}
	}
	// locale and doclet needs to be determined first
	docletClass = preProcess(fileManager, options);

	if (jdk.javadoc.doclet.Doclet.class.isAssignableFrom(docletClass)) {
	// no need to dispatch to old, safe to init now
	initMessager();
	messager.setLocale(locale);
	try {
	doclet = (Doclet) docletClass.newInstance();
	} catch (InstantiationException \| IllegalAccessException exc) {
	exc.printStackTrace();
	if (!apiMode) {
	error("main.could_not_instantiate_class", docletClass);
	messager.exit();
	}
	throw new ClientCodeException(exc);
	}
	} else {
	if (this.apiMode) {
	com.sun.tools.javadoc.Start ostart
	= new com.sun.tools.javadoc.Start(context);
	return ostart.begin(docletClass, options, fileObjects);
	}
	String[] array = options.toArray(new String[options.size()]);
	return com.sun.tools.javadoc.Main.execute(array) == 0;
	}

	boolean failed = false;
	try {
	failed = !parseAndExecute(options, fileObjects);
	} catch (Messager.ExitJavadoc exc) {
	// ignore, we just exit this way
	} catch (OutOfMemoryError ee) {
	messager.error("main.out.of.memory");
	failed = true;
	} catch (ClientCodeException e) {
	// simply rethrow these exceptions, to be caught and handled by JavadocTaskImpl
	throw e;
	} catch (Error ee) {
	ee.printStackTrace(System.err);
	messager.error("main.fatal.error");
	failed = true;
	} catch (Exception ee) {
	ee.printStackTrace(System.err);
	messager.error("main.fatal.exception");
	failed = true;
	} finally {
	if (fileManager != null
	&& fileManager instanceof BaseFileManager
	&& ((BaseFileManager) fileManager).autoClose) {
	try {
	fileManager.close();
	} catch (IOException ignore) {}
	}
	boolean haveErrorWarnings = messager.nerrors() > 0 \|\|
	(rejectWarnings && messager.nwarnings() > 0);
	if (failed && !haveErrorWarnings) {
	// the doclet failed, but nothing reported, flag it!.
	messager.error("main.unknown.error");
	}
	failed \|= haveErrorWarnings;
	messager.exitNotice();
	messager.flush();
	}
	return !failed;
	}

	/**
	* Ensures that the module of the given class is readable to this
	* module.
	* @param targetClass class in module to be made readable
	*/
	private void ensureReadable(Class<?> targetClass) {
	try {
	Method getModuleMethod = Class.class.getMethod("getModule");
	Object thisModule = getModuleMethod.invoke(this.getClass());
	Object targetModule = getModuleMethod.invoke(targetClass);

	Class<?> moduleClass = getModuleMethod.getReturnType();
	Method addReadsMethod = moduleClass.getMethod("addReads", moduleClass);
	addReadsMethod.invoke(thisModule, targetModule);
	} catch (NoSuchMethodException e) {
	// ignore
	} catch (Exception e) {
	throw new InternalError(e);
	}
	}

	/**
	* Main program - internal
	*/
	private boolean parseAndExecute(List<String> argList,
	Iterable<? extends JavaFileObject> fileObjects) throws IOException {
	long tm = System.currentTimeMillis();

	List<String> javaNames = new ArrayList<>();

	compOpts = Options.instance(context);

	// Make sure no obsolete source/target messages are reported
	compOpts.put("-Xlint:-options", "-Xlint:-options");

	doclet.init(locale, messager);
	parseArgs(argList, javaNames);

	if (fileManager instanceof BaseFileManager) {
	((BaseFileManager) fileManager).handleOptions(fileManagerOpts);
	}

	String platformString = compOpts.get("-release");

	if (platformString != null) {
	if (compOpts.isSet("-source")) {
	usageError("main.release.bootclasspath.conflict", "-source");
	}
	if (fileManagerOpts.containsKey(BOOTCLASSPATH)) {
	usageError("main.release.bootclasspath.conflict", BOOTCLASSPATH.getText());
	}

	PlatformDescription platformDescription =
	PlatformUtils.lookupPlatformDescription(platformString);

	if (platformDescription == null) {
	usageError("main.unsupported.release.version", platformString);
	}

	compOpts.put(SOURCE, platformDescription.getSourceVersion());

	context.put(PlatformDescription.class, platformDescription);

	Collection<Path> platformCP = platformDescription.getPlatformPath();

	if (platformCP != null) {
	if (fileManager instanceof StandardJavaFileManager) {
	StandardJavaFileManager sfm = (StandardJavaFileManager) fileManager;

	sfm.setLocationFromPaths(StandardLocation.PLATFORM_CLASS_PATH, platformCP);
	} else {
	usageError("main.release.not.standard.file.manager", platformString);
	}
	}
	}

	compOpts.notifyListeners();

	if (javaNames.isEmpty() && subPackages.isEmpty() && isEmpty(fileObjects)) {
	usageError("main.No_packages_or_classes_specified");
	}

	JavadocTool comp = JavadocTool.make0(context);
	if (comp == null) return false;

	if (showAccess == null) {
	setFilter(defaultModifier);
	}

	DocletEnvironment root = comp.getEnvironment(
	encoding,
	showAccess,
	overviewpath,
	javaNames,
	fileObjects,
	subPackages,
	excludedPackages,
	docClasses,
	quiet);

	// release resources
	comp = null;

	if (breakiterator \|\| !locale.getLanguage().equals(Locale.ENGLISH.getLanguage())) {
	JavacTrees trees = JavacTrees.instance(context);
	trees.setBreakIterator(BreakIterator.getSentenceInstance(locale));
	}
	// pass off control to the doclet
	boolean ok = root != null;
	if (ok) ok = doclet.run(root);

	// We're done.
	if (compOpts.get("-verbose") != null) {
	tm = System.currentTimeMillis() - tm;
	messager.notice("main.done_in", Long.toString(tm));
	}

	return ok;
	}

	Set<Doclet.Option> docletOptions = null;
	int handleDocletOptions(int idx, List<String> args, boolean isToolOption) {
	if (docletOptions == null) {
	docletOptions = doclet.getSupportedOptions();
	}
	String arg = args.get(idx);

	for (Doclet.Option opt : docletOptions) {
	if (opt.matches(arg)) {
	if (args.size() - idx < opt.getArgumentCount()) {
	usageError("main.requires_argument", arg);
	}
	opt.process(arg, args.listIterator(idx + 1));
	idx += opt.getArgumentCount();
	return idx;
	}
	}
	// check if arg is accepted by the tool before emitting error
	if (!isToolOption)
	usageError("main.invalid_flag", arg);
	return idx;
	}

	private Class<?> preProcess(JavaFileManager jfm, List<String> argv) {
	// doclet specifying arguments
	String userDocletPath = null;
	String userDocletName = null;

	// Step 1: loop through the args, set locale early on, if found.
	for (int i = 0 ; i < argv.size() ; i++) {
	String arg = argv.get(i);
	if (arg.equals(ToolOption.LOCALE.opt)) {
	oneArg(argv, i++);
	String lname = argv.get(i);
	locale = getLocale(lname);
	} else if (arg.equals(ToolOption.DOCLET.opt)) {
	oneArg(argv, i++);
	if (userDocletName != null) {
	usageError("main.more_than_one_doclet_specified_0_and_1",
	userDocletName, argv.get(i));
	}
	if (docletName != null) {
	usageError("main.more_than_one_doclet_specified_0_and_1",
	docletName, argv.get(i));
	}
	userDocletName = argv.get(i);
	} else if (arg.equals(ToolOption.DOCLETPATH.opt)) {
	oneArg(argv, i++);
	if (userDocletPath == null) {
	userDocletPath = argv.get(i);
	} else {
	userDocletPath += File.pathSeparator + argv.get(i);
	}
	}
	}
	// Step 2: a doclet has already been provided,
	// nothing more to do.
	if (docletClass != null) {
	return docletClass;
	}
	// Step 3: doclet name specified ? if so find a ClassLoader,
	// and load it.
	if (userDocletName != null) {
	ClassLoader cl = classLoader;
	if (cl == null) {
	if (!fileManager.hasLocation(DOCLET_PATH)) {
	List<File> paths = new ArrayList<>();
	if (userDocletPath != null) {
	for (String pathname : userDocletPath.split(File.pathSeparator)) {
	paths.add(new File(pathname));
	}
	}
	try {
	((StandardJavaFileManager)fileManager).setLocation(DOCLET_PATH, paths);
	} catch (IOException ioe) {
	panic("main.doclet_no_classloader_found", ioe);
	return null; // keep compiler happy
	}
	}
	cl = fileManager.getClassLoader(DOCLET_PATH);
	if (cl == null) {
	// despite doclet specified on cmdline no classloader found!
	panic("main.doclet_no_classloader_found", userDocletName);
	return null; // keep compiler happy
	}
	try {
	Class<?> klass = cl.loadClass(userDocletName);
	ensureReadable(klass);
	return klass;
	} catch (ClassNotFoundException cnfe) {
	panic("main.doclet_class_not_found", userDocletName);
	return null; // keep compiler happy
	}
	}
	}
	// Step 4: we have a doclet, try loading it, otherwise
	// return back the standard doclet
	if (docletName != null) {
	try {
	return Class.forName(docletName, true, getClass().getClassLoader());
	} catch (ClassNotFoundException cnfe) {
	panic("main.doclet_class_not_found", userDocletName);
	return null; // happy compiler, should not happen
	}
	} else {
	return jdk.javadoc.internal.doclets.standard.Standard.class;
	}
	}

	private void parseArgs(List<String> args, List<String> javaNames) {
	for (int i = 0 ; i < args.size() ; i++) {
	String arg = args.get(i);
	ToolOption o = ToolOption.get(arg);
	if (o != null) {
	// handle a doclet argument that may be needed however
	// don't increment the index, and allow the tool to consume args
	handleDocletOptions(i, args, true);

	if (o.hasArg) {
	oneArg(args, i++);
	o.process(this, args.get(i));
	} else {
	setOption(arg);
	o.process(this);
	}
	} else if (arg.startsWith("-XD")) {
	// hidden javac options
	String s = arg.substring("-XD".length());
	int eq = s.indexOf('=');
	String key = (eq < 0) ? s : s.substring(0, eq);
	String value = (eq < 0) ? s : s.substring(eq+1);
	compOpts.put(key, value);
	} else if (arg.startsWith("-")) {
	i = handleDocletOptions(i, args, false);
	} else {
	javaNames.add(arg);
	}
	}
	}

	private <T> boolean isEmpty(Iterable<T> iter) {
	return !iter.iterator().hasNext();
	}

	/**
	* Set one arg option.
	* Error and exit if one argument is not provided.
	*/
	private void oneArg(List<String> args, int index) {
	if ((index + 1) < args.size()) {
	setOption(args.get(index), args.get(index+1));
	} else {
	usageError("main.requires_argument", args.get(index));
	}
	}

	@Override
	void usageError(String key, Object... args) {
	error(key, args);
	usage(true);
	}

	// a terminal call, will not return
	void panic(String key, Object... args) {
	error(key, args);
	messager.exit();
	}

	void error(String key, Object... args) {
	messager.error(key, args);
	}

	/**
	* indicate an option with no arguments was given.
	*/
	private void setOption(String opt) {
	String[] option = { opt };
	options.add(Arrays.asList(option));
	}

	/**
	* indicate an option with one argument was given.
	*/
	private void setOption(String opt, String argument) {
	String[] option = { opt, argument };
	options.add(Arrays.asList(option));
	}

	/**
	* indicate an option with the specified list of arguments was given.
	*/
	private void setOption(String opt, List<String> arguments) {
	List<String> args = new ArrayList<>(arguments.size() + 1);
	args.add(opt);
	args.addAll(arguments);
	options.add(args);
	}

	/**
	* Get the locale if specified on the command line
	* else return null and if locale option is not used
	* then return default locale.
	*/
	private Locale getLocale(String localeName) {
	Locale userlocale = null;
	if (localeName == null \|\| localeName.isEmpty()) {
	return Locale.getDefault();
	}
	int firstuscore = localeName.indexOf('_');
	int seconduscore = -1;
	String language = null;
	String country = null;
	String variant = null;
	if (firstuscore == 2) {
	language = localeName.substring(0, firstuscore);
	seconduscore = localeName.indexOf('_', firstuscore + 1);
	if (seconduscore > 0) {
	if (seconduscore != firstuscore + 3
	\|\| localeName.length() <= seconduscore + 1) {
	usageError("main.malformed_locale_name", localeName);
	return null;
	}
	country = localeName.substring(firstuscore + 1,
	seconduscore);
	variant = localeName.substring(seconduscore + 1);
	} else if (localeName.length() == firstuscore + 3) {
	country = localeName.substring(firstuscore + 1);
	} else {
	usageError("main.malformed_locale_name", localeName);
	return null;
	}
	} else if (firstuscore == -1 && localeName.length() == 2) {
	language = localeName;
	} else {
	usageError("main.malformed_locale_name", localeName);
	return null;
	}
	userlocale = searchLocale(language, country, variant);
	if (userlocale == null) {
	usageError("main.illegal_locale_name", localeName);
	return null;
	} else {
	return userlocale;
	}
	}

	/**
	* Search the locale for specified language, specified country and
	* specified variant.
	*/
	private Locale searchLocale(String language, String country,
	String variant) {
	for (Locale loc : Locale.getAvailableLocales()) {
	if (loc.getLanguage().equals(language) &&
	(country == null \|\| loc.getCountry().equals(country)) &&
	(variant == null \|\| loc.getVariant().equals(variant))) {
	return loc;
	}
	}
	return null;
	}
	}