/*

 * Copyright (c) 2013, 2015, 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.

 */

/*

 * @test

 * @bug 8029800

 * @summary String.toLowerCase()/toUpperCase is generally dangerous, check it is not used in langtools

 * @modules jdk.jdeps/com.sun.tools.classfile

 */

import java.io.*;

import java.util.*;

import javax.tools.*;

import com.sun.tools.classfile.*;

import com.sun.tools.classfile.ConstantPool.CONSTANT_Methodref_info;

public class NoStringToLower {

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

        NoStringToLower c = new NoStringToLower();

        if (c.run(args))

            return;

        if (is_jtreg())

            throw new Exception(c.errors + " errors occurred");

        else

            System.exit(1);

    }

    static boolean is_jtreg() {

        return (System.getProperty("test.src") != null);

    }

    /**

     * Main entry point.

     */

    boolean run(String... args) throws Exception {

        JavaCompiler c = ToolProvider.getSystemJavaCompiler();

        try (JavaFileManager fm = c.getStandardFileManager(null, null, null)) {

            JavaFileManager.Location javacLoc = findJavacLocation(fm);

            String[] pkgs = {

                "javax.annotation.processing",

                "javax.lang.model",

                "javax.tools",

                "com.sun.source",

                "com.sun.tools.classfile",

                "com.sun.tools.doclet",

                "com.sun.tools.doclint",

                "com.sun.tools.javac",

                "com.sun.tools.javadoc",

                "com.sun.tools.javah",

                "com.sun.tools.javap",

                "com.sun.tools.jdeps",

                "com.sun.tools.sjavac"

            };

            for (String pkg: pkgs) {

                for (JavaFileObject fo: fm.list(javacLoc,

                        pkg, EnumSet.of(JavaFileObject.Kind.CLASS), true)) {

                    scan(fo);

                }

            }

            return (errors == 0);

        }

    }

    // depending on how the test is run, javac may be on bootclasspath or classpath

    JavaFileManager.Location findJavacLocation(JavaFileManager fm) {

        JavaFileManager.Location[] locns =

            { StandardLocation.PLATFORM_CLASS_PATH, StandardLocation.CLASS_PATH };

        try {

            for (JavaFileManager.Location l: locns) {

                JavaFileObject fo = fm.getJavaFileForInput(l,

                    "com.sun.tools.javac.Main", JavaFileObject.Kind.CLASS);

                if (fo != null)

                    return l;

            }

        } catch (IOException e) {

            throw new Error(e);

        }

        throw new IllegalStateException("Cannot find javac");

    }

    /**

     * Verify there are no references to String.toLowerCase() in a class file.

     */

    void scan(JavaFileObject fo) throws IOException {

        InputStream in = fo.openInputStream();

        try {

            ClassFile cf = ClassFile.read(in);

            for (ConstantPool.CPInfo cpinfo: cf.constant_pool.entries()) {

                if (cpinfo.getTag() == ConstantPool.CONSTANT_Methodref) {

                    CONSTANT_Methodref_info ref = (CONSTANT_Methodref_info) cpinfo;

                    String methodDesc = ref.getClassInfo().getName() + "." + ref.getNameAndTypeInfo().getName() + ":" + ref.getNameAndTypeInfo().getType();

                    if ("java/lang/String.toLowerCase:()Ljava/lang/String;".equals(methodDesc)) {

                        error("found reference to String.toLowerCase() in: " + fo.getName());

                    }

                    if ("java/lang/String.toUpperCase:()Ljava/lang/String;".equals(methodDesc)) {

                        error("found reference to String.toLowerCase() in: " + fo.getName());

                    }

                }

            }

        } catch (ConstantPoolException ignore) {

        } finally {

            in.close();

        }

    }

    /**

     * Report an error.

     */

    void error(String msg) {

        System.err.println("Error: " + msg);

        errors++;

    }

    int errors;

}