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 * 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,

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 *

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 */

/*

 * @test

 * @bug 8003967

 * @summary detect and remove all mutable implicit static enum fields in langtools

 * @run main DetectMutableStaticFields

 */

import java.io.File;

import java.io.IOException;

import java.net.URI;

import java.net.URISyntaxException;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.EnumSet;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import javax.tools.JavaCompiler;

import javax.tools.JavaFileManager;

import javax.tools.JavaFileObject;

import javax.tools.StandardJavaFileManager;

import javax.tools.StandardLocation;

import javax.tools.ToolProvider;

import com.sun.tools.classfile.ClassFile;

import com.sun.tools.classfile.ConstantPoolException;

import com.sun.tools.classfile.Descriptor;

import com.sun.tools.classfile.Descriptor.InvalidDescriptor;

import com.sun.tools.classfile.Field;

import static javax.tools.JavaFileObject.Kind.CLASS;

import static com.sun.tools.classfile.AccessFlags.ACC_ENUM;

import static com.sun.tools.classfile.AccessFlags.ACC_FINAL;

import static com.sun.tools.classfile.AccessFlags.ACC_STATIC;

public class DetectMutableStaticFields {

    private static final String keyResource =

            "com/sun/tools/javac/tree/JCTree.class";

    private String[] packagesToSeekFor = new String[] {

        "javax.tools",

        "javax.lang.model",

        "com.sun.javadoc",

        "com.sun.source",

        "com.sun.tools.classfile",

        "com.sun.tools.doclets",

        "com.sun.tools.javac",

        "com.sun.tools.javadoc",

        "com.sun.tools.javah",

        "com.sun.tools.javap",

    };

    private static final Map<String, List<String>> classFieldsToIgnoreMap = new HashMap<>();

    static {

        classFieldsToIgnoreMap.

                put("javax/tools/ToolProvider",

                    Arrays.asList("instance"));

        classFieldsToIgnoreMap.

                put("com/sun/tools/javah/JavahTask",

                    Arrays.asList("versionRB"));

        classFieldsToIgnoreMap.

                put("com/sun/tools/classfile/Dependencies$DefaultFilter",

                    Arrays.asList("instance"));

        classFieldsToIgnoreMap.

                put("com/sun/tools/javap/JavapTask",

                    Arrays.asList("versionRB"));

        classFieldsToIgnoreMap.

                put("com/sun/tools/doclets/formats/html/HtmlDoclet",

                    Arrays.asList("docletToStart"));

        classFieldsToIgnoreMap.

                put("com/sun/tools/javac/util/JCDiagnostic",

                    Arrays.asList("fragmentFormatter"));

        classFieldsToIgnoreMap.

                put("com/sun/tools/javac/util/JavacMessages",

                    Arrays.asList("defaultBundle", "defaultMessages"));

        classFieldsToIgnoreMap.

                put("com/sun/tools/javac/file/ZipFileIndexCache",

                    Arrays.asList("sharedInstance"));

        classFieldsToIgnoreMap.

                put("com/sun/tools/javac/file/JRTIndex",

                    Arrays.asList("sharedInstance"));

        classFieldsToIgnoreMap.

                put("com/sun/tools/javac/main/JavaCompiler",

                    Arrays.asList("versionRB"));

        classFieldsToIgnoreMap.

                put("com/sun/tools/javac/code/Type",

                    Arrays.asList("moreInfo"));

        classFieldsToIgnoreMap.

                put("com/sun/tools/javac/util/SharedNameTable",

                    Arrays.asList("freelist"));

        classFieldsToIgnoreMap.

                put("com/sun/tools/javac/util/Log",

                    Arrays.asList("useRawMessages"));

    }

    private List<String> errors = new ArrayList<>();

    public static void main(String[] args) {

        try {

            new DetectMutableStaticFields().run();

        } catch (Exception ex) {

            throw new AssertionError(

                    "Exception during test execution with cause ",

                    ex.getCause());

        }

    }

    private void run()

        throws

            IOException,

            ConstantPoolException,

            InvalidDescriptor,

            URISyntaxException {

        URI resource = findResource(keyResource);

        if (resource == null) {

            throw new AssertionError("Resource " + keyResource +

                "not found in the class path");

        }

        analyzeResource(resource);

        if (errors.size() > 0) {

            for (String error: errors) {

                System.err.println(error);

            }

            throw new AssertionError("There are mutable fields, "

                + "please check output");

        }

    }

    URI findResource(String className) throws URISyntaxException {

        URI uri = getClass().getClassLoader().getResource(className).toURI();

        if (uri.getScheme().equals("jar")) {

            String ssp = uri.getRawSchemeSpecificPart();

            int sep = ssp.lastIndexOf("!");

            uri = new URI(ssp.substring(0, sep));

        } else if (uri.getScheme().equals("file")) {

            uri = new URI(uri.getPath().substring(0,

                    uri.getPath().length() - keyResource.length()));

        }

        return uri;

    }

    boolean shouldAnalyzePackage(String packageName) {

        for (String aPackage: packagesToSeekFor) {

            if (packageName.contains(aPackage)) {

                return true;

            }

        }

        return false;

    }

    void analyzeResource(URI resource)

        throws

            IOException,

            ConstantPoolException,

            InvalidDescriptor {

        JavaCompiler tool = ToolProvider.getSystemJavaCompiler();

        try (StandardJavaFileManager fm = tool.getStandardFileManager(null, null, null)) {

            JavaFileManager.Location location =

                    StandardLocation.locationFor(resource.getPath());

            fm.setLocation(location, com.sun.tools.javac.util.List.of(

                    new File(resource.getPath())));

            for (JavaFileObject file : fm.list(location, "", EnumSet.of(CLASS), true)) {

                String className = fm.inferBinaryName(location, file);

                int index = className.lastIndexOf('.');

                String pckName = index == -1 ? "" : className.substring(0, index);

                if (shouldAnalyzePackage(pckName)) {

                    analyzeClassFile(ClassFile.read(file.openInputStream()));

                }

            }

        }

    }

    List<String> currentFieldsToIgnore;

    boolean ignoreField(String field) {

        if (currentFieldsToIgnore != null) {

            for (String fieldToIgnore : currentFieldsToIgnore) {

                if (field.equals(fieldToIgnore)) {

                    return true;

                }

            }

        }

        return false;

    }

    void analyzeClassFile(ClassFile classFileToCheck)

        throws

            IOException,

            ConstantPoolException,

            Descriptor.InvalidDescriptor {

        boolean enumClass =

                (classFileToCheck.access_flags.flags & ACC_ENUM) != 0;

        boolean nonFinalStaticEnumField;

        boolean nonFinalStaticField;

        currentFieldsToIgnore =

                classFieldsToIgnoreMap.get(classFileToCheck.getName());

        for (Field field : classFileToCheck.fields) {

            if (ignoreField(field.getName(classFileToCheck.constant_pool))) {

                continue;

            }

            nonFinalStaticEnumField =

                    (field.access_flags.flags & (ACC_ENUM | ACC_FINAL)) == 0;

            nonFinalStaticField =

                    (field.access_flags.flags & ACC_STATIC) != 0 &&

                    (field.access_flags.flags & ACC_FINAL) == 0;

            if (enumClass ? nonFinalStaticEnumField : nonFinalStaticField) {

                errors.add("There is a mutable field named " +

                        field.getName(classFileToCheck.constant_pool) +

                        ", at class " +

                        classFileToCheck.getName());

            }

        }

    }

}