/*

 * Copyright (c) 2010, 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.

 *

 * 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.

 */

import com.sun.source.util.TaskEvent;

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.Dimension;

import java.awt.EventQueue;

import java.awt.Font;

import java.awt.GridBagConstraints;

import java.awt.GridBagLayout;

import java.awt.Rectangle;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import javax.swing.DefaultComboBoxModel;

import javax.swing.JComboBox;

import javax.swing.JComponent;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JPanel;

import javax.swing.JScrollPane;

import javax.swing.JTextArea;

import javax.swing.JTextField;

import javax.swing.SwingUtilities;

import javax.swing.event.CaretEvent;

import javax.swing.event.CaretListener;

import javax.swing.text.BadLocationException;

import javax.swing.text.DefaultHighlighter;

import javax.swing.text.Highlighter;

import java.io.File;

import java.io.IOException;

import java.io.PrintStream;

import java.io.PrintWriter;

import java.io.StringWriter;

import java.lang.reflect.Field;

import java.lang.reflect.Modifier;

import java.nio.charset.Charset;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import javax.tools.Diagnostic;

import javax.tools.DiagnosticListener;

import javax.tools.JavaFileObject;

import javax.tools.StandardJavaFileManager;

import com.sun.source.tree.CompilationUnitTree;

import com.sun.source.util.JavacTask;

import com.sun.source.util.TaskListener;

import com.sun.tools.javac.api.JavacTool;

import com.sun.tools.javac.code.Symbol;

import com.sun.tools.javac.code.Type;

import com.sun.tools.javac.tree.JCTree;

import com.sun.tools.javac.tree.JCTree.JCClassDecl;

import com.sun.tools.javac.tree.JCTree.JCCompilationUnit;

import com.sun.tools.javac.tree.JCTree.JCImport;

import com.sun.tools.javac.tree.TreeInfo;

import com.sun.tools.javac.tree.TreeScanner;

import com.sun.tools.javac.util.Pair;

import java.util.Arrays;

import java.util.HashSet;

import java.util.Set;

import javax.lang.model.element.Element;

/**

 * Utility and test program to check validity of tree positions for tree nodes.

 * The program can be run standalone, or as a jtreg test.  In standalone mode,

 * errors can be displayed in a gui viewer. For info on command line args,

 * run program with no args.

 *

 * <p>

 * jtreg: Note that by using the -r switch in the test description below, this test

 * will process all java files in the langtools/test directory, thus implicitly

 * covering any new language features that may be tested in this test suite.

 */

/*

 * @test

 * @bug 6970584

 * @summary assorted position errors in compiler syntax trees

 * @run main CheckAttributedTree -q -r -et ERRONEOUS .

 */

public class CheckAttributedTree {

    /**

     * Main entry point.

     * If test.src is set, program runs in jtreg mode, and will throw an Error

     * if any errors arise, otherwise System.exit will be used, unless the gui

     * viewer is being used. In jtreg mode, the default base directory for file

     * args is the value of ${test.src}. In jtreg mode, the -r option can be

     * given to change the default base directory to the root test directory.

     */

    public static void main(String... args) {

        String testSrc = System.getProperty("test.src");

        File baseDir = (testSrc == null) ? null : new File(testSrc);

        boolean ok = new CheckAttributedTree().run(baseDir, args);

        if (!ok) {

            if (testSrc != null)  // jtreg mode

                throw new Error("failed");

            else

                System.exit(1);

        }

    }

    /**

     * Run the program. A base directory can be provided for file arguments.

     * In jtreg mode, the -r option can be given to change the default base

     * directory to the test root directory. For other options, see usage().

     * @param baseDir base directory for any file arguments.

     * @param args command line args

     * @return true if successful or in gui mode

     */

    boolean run(File baseDir, String... args) {

        if (args.length == 0) {

            usage(System.out);

            return true;

        }

        List<File> files = new ArrayList<File>();

        for (int i = 0; i < args.length; i++) {

            String arg = args[i];

            if (arg.equals("-encoding") && i + 1 < args.length)

                encoding = args[++i];

            else if (arg.equals("-gui"))

                gui = true;

            else if (arg.equals("-q"))

                quiet = true;

            else if (arg.equals("-v"))

                verbose = true;

            else if (arg.equals("-t") && i + 1 < args.length)

                tags.add(args[++i]);

            else if (arg.equals("-ef") && i + 1 < args.length)

                excludeFiles.add(new File(baseDir, args[++i]));

            else if (arg.equals("-et") && i + 1 < args.length)

                excludeTags.add(args[++i]);

            else if (arg.equals("-r")) {

                if (excludeFiles.size() > 0)

                    throw new Error("-r must be used before -ef");

                File d = baseDir;

                while (!new File(d, "TEST.ROOT").exists()) {

                    if (d == null)

                        throw new Error("cannot find TEST.ROOT");

                    d = d.getParentFile();

                }

                baseDir = d;

            }

            else if (arg.startsWith("-"))

                throw new Error("unknown option: " + arg);

            else {

                while (i < args.length)

                    files.add(new File(baseDir, args[i++]));

            }

        }

        for (File file: files) {

            if (file.exists())

                test(file);

            else

                error("File not found: " + file);

        }

        if (fileCount != 1)

            System.err.println(fileCount + " files read");

        if (errors > 0)

            System.err.println(errors + " errors");

        return (gui || errors == 0);

    }

    /**

     * Print command line help.

     * @param out output stream

     */

    void usage(PrintStream out) {

        out.println("Usage:");

        out.println("  java CheckAttributedTree options... files...");

        out.println("");

        out.println("where options include:");

        out.println("-q        Quiet: don't report on inapplicable files");

        out.println("-gui      Display returns in a GUI viewer");

        out.println("-v        Verbose: report on files as they are being read");

        out.println("-t tag    Limit checks to tree nodes with this tag");

        out.println("          Can be repeated if desired");

        out.println("-ef file  Exclude file or directory");

        out.println("-et tag   Exclude tree nodes with given tag name");

        out.println("");

        out.println("files may be directories or files");

        out.println("directories will be scanned recursively");

        out.println("non java files, or java files which cannot be parsed, will be ignored");

        out.println("");

    }

    /**

     * Test a file. If the file is a directory, it will be recursively scanned

     * for java files.

     * @param file the file or directory to test

     */

    void test(File file) {

        if (excludeFiles.contains(file)) {

            if (!quiet)

                error("File " + file + " excluded");

            return;

        }

        if (file.isDirectory()) {

            for (File f: file.listFiles()) {

                test(f);

            }

            return;

        }

        if (file.isFile() && file.getName().endsWith(".java")) {

            try {

                if (verbose)

                    System.err.println(file);

                fileCount++;

                NPETester p = new NPETester();

                p.test(read(file));

            } catch (AttributionException e) {

                if (!quiet) {

                    error("Error attributing " + file + "\n" + e.getMessage());

                }

            } catch (IOException e) {

                error("Error reading " + file + ": " + e);

            }

            return;

        }

        if (!quiet)

            error("File " + file + " ignored");

    }

    /**

     * Read a file.

     * @param file the file to be read

     * @return the tree for the content of the file

     * @throws IOException if any IO errors occur

     * @throws TreePosTest.ParseException if any errors occur while parsing the file

     */

    List<Pair<JCCompilationUnit, JCTree>> read(File file) throws IOException, AttributionException {

        StringWriter sw = new StringWriter();

        PrintWriter pw = new PrintWriter(sw);

        Reporter r = new Reporter(pw);

        JavacTool tool = JavacTool.create();

        Charset cs = (encoding == null ? null : Charset.forName(encoding));

        StandardJavaFileManager fm = tool.getStandardFileManager(r, null, null);

        Iterable<? extends JavaFileObject> files = fm.getJavaFileObjects(file);

        String[] opts = { "-XDshouldStopPolicy=ATTR", "-XDverboseCompilePolicy" };

        JavacTask task = tool.getTask(pw, fm, r, Arrays.asList(opts), null, files);

        final List<Element> analyzedElems = new ArrayList<>();

        task.setTaskListener(new TaskListener() {

            public void started(TaskEvent e) {

                if (e.getKind() == TaskEvent.Kind.ANALYZE)

                        analyzedElems.add(e.getTypeElement());

            }

            public void finished(TaskEvent e) { }

        });

        try {

            Iterable<? extends CompilationUnitTree> trees = task.parse();

            task.analyze();

            List<Pair<JCCompilationUnit, JCTree>> res = new ArrayList<>();

            for (CompilationUnitTree t : trees) {

               JCCompilationUnit cu = (JCCompilationUnit)t;

               for (JCTree def : cu.defs) {

                   if (def.getTag() == JCTree.CLASSDEF &&

                           analyzedElems.contains(((JCTree.JCClassDecl)def).sym)) {

                       res.add(new Pair<>(cu, def));

                   }

               }

            }

            return res;

        }

        catch (Throwable t) {

            throw new AttributionException("Exception while attributing file: " + file);

        }

    }

    /**

     * Report an error. When the program is complete, the program will either

     * exit or throw an Error if any errors have been reported.

     * @param msg the error message

     */

    void error(String msg) {

        System.err.println(msg);

        errors++;

    }

    /** Number of files that have been analyzed. */

    int fileCount;

    /** Number of errors reported. */

    int errors;

    /** Flag: don't report irrelevant files. */

    boolean quiet;

    /** Flag: show errors in GUI viewer. */

    boolean gui;

    /** The GUI viewer for errors. */

    Viewer viewer;

    /** Flag: report files as they are processed. */

    boolean verbose;

    /** Option: encoding for test files. */

    String encoding;

    /** The set of tags for tree nodes to be analyzed; if empty, all tree nodes

     * are analyzed. */

    Set<String> tags = new HashSet<String>();

    /** Set of files and directories to be excluded from analysis. */

    Set<File> excludeFiles = new HashSet<File>();

    /** Set of tag names to be excluded from analysis. */

    Set<String> excludeTags = new HashSet<String>();

    /** Utility class for trees */

    TreeUtil treeUtil = new TreeUtil();

    /**

     * Main class for testing assertions concerning types/symbol

     * left uninitialized after attribution

     */

    private class NPETester extends TreeScanner {

        void test(List<Pair<JCCompilationUnit, JCTree>> trees) {

            for (Pair<JCCompilationUnit, JCTree> p : trees) {

                sourcefile = p.fst.sourcefile;

                endPosTable = p.fst.endPositions;

                encl = new Info(p.snd, endPosTable);

                p.snd.accept(this);

            }

        }

        @Override

        public void scan(JCTree tree) {

            if (tree == null ||

                    excludeTags.contains(treeUtil.nameFromTag(tree.getTag()))) {

                return;

            }

            Info self = new Info(tree, endPosTable);

            check(!mandatoryType(tree) ||

                    (tree.type != null &&

                    checkFields(tree)),

                    "'null' found in tree ",

                    self);

            Info prevEncl = encl;

            encl = self;

            tree.accept(this);

            encl = prevEncl;

        }

        private boolean mandatoryType(JCTree that) {

            return that instanceof JCTree.JCExpression ||

                    that.getTag() == JCTree.VARDEF ||

                    that.getTag() == JCTree.METHODDEF ||

                    that.getTag() == JCTree.CLASSDEF;

        }

        private final List<String> excludedFields = Arrays.asList("varargsElement");

        void check(boolean ok, String label, Info self) {

            if (!ok) {

                if (gui) {

                    if (viewer == null)

                        viewer = new Viewer();

                    viewer.addEntry(sourcefile, label, encl, self);

                }

                error(label + self.toString() + " encl: " + encl.toString() + " in file: " + sourcefile + "  " + self.tree);

            }

        }

        boolean checkFields(JCTree t) {

            List<Field> fieldsToCheck = treeUtil.getFieldsOfType(t,

                    excludedFields,

                    Symbol.class,

                    Type.class);

            for (Field f : fieldsToCheck) {

                try {

                    if (f.get(t) == null) {

                        return false;

                    }

                }

                catch (IllegalAccessException e) {

                    System.err.println("Cannot read field: " + f);

                    //swallow it

                }

            }

            return true;

        }

        @Override

        public void visitImport(JCImport tree) { }

        @Override

        public void visitTopLevel(JCCompilationUnit tree) {

            scan(tree.defs);

        }

        JavaFileObject sourcefile;

        Map<JCTree, Integer> endPosTable;

        Info encl;

    }

    /**

     * Utility class providing easy access to position and other info for a tree node.

     */

    private class Info {

        Info() {

            tree = null;

            tag = JCTree.ERRONEOUS;

            start = 0;

            pos = 0;

            end = Integer.MAX_VALUE;

        }

        Info(JCTree tree, Map<JCTree, Integer> endPosTable) {

            this.tree = tree;

            tag = tree.getTag();

            start = TreeInfo.getStartPos(tree);

            pos = tree.pos;

            end = TreeInfo.getEndPos(tree, endPosTable);

        }

        @Override

        public String toString() {

            return treeUtil.nameFromTag(tree.getTag()) + "[start:" + start + ",pos:" + pos + ",end:" + end + "]";

        }

        final JCTree tree;

        final int tag;

        final int start;

        final int pos;

        final int end;

    }

    /**

     * Names for tree tags.

     * javac does not provide an API to convert tag values to strings, so this class uses

     * reflection to determine names of public static final int values in JCTree.

     */

    private static class TreeUtil {

        String nameFromTag(int tag) {

            if (names == null) {

                names = new HashMap<Integer, String>();

                Class c = JCTree.class;

                for (Field f : c.getDeclaredFields()) {

                    if (f.getType().equals(int.class)) {

                        int mods = f.getModifiers();

                        if (Modifier.isPublic(mods) && Modifier.isStatic(mods) && Modifier.isFinal(mods)) {

                            try {

                                names.put(f.getInt(null), f.getName());

                            } catch (IllegalAccessException e) {

                            }

                        }

                    }

                }

            }

            String name = names.get(tag);

            return (name == null) ? "??" : name;

        }

        List<Field> getFieldsOfType(JCTree t, List<String> excludeNames, Class<?>... types) {

            List<Field> buf = new ArrayList<Field>();

            for (Field f : t.getClass().getDeclaredFields()) {

                if (!excludeNames.contains(f.getName())) {

                    for (Class<?> type : types) {

                        if (type.isAssignableFrom(f.getType())) {

                            f.setAccessible(true);

                            buf.add(f);

                            break;

                        }

                    }

                }

            }

            return buf;

        }

        private Map<Integer, String> names;

    }

    /**

     * Thrown when errors are found parsing a java file.

     */

    private static class ParseException extends Exception {

        ParseException(String msg) {

            super(msg);

        }

    }

    private static class AttributionException extends Exception {

        AttributionException(String msg) {

            super(msg);

        }

    }

    /**

     * DiagnosticListener to report diagnostics and count any errors that occur.

     */

    private static class Reporter implements DiagnosticListener<JavaFileObject> {

        Reporter(PrintWriter out) {

            this.out = out;

        }

        public void report(Diagnostic<? extends JavaFileObject> diagnostic) {

            out.println(diagnostic);

            switch (diagnostic.getKind()) {

                case ERROR:

                    errors++;

            }