/*

 * 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 8025998 8026749 8054220 8058227

 * @summary Missing LV table in lambda bodies

 * @compile -g LocalVariableTable.java

 * @run main LocalVariableTable

 */

import java.io.*;

import java.lang.annotation.*;

import java.util.*;

import com.sun.tools.classfile.*;

/*

 * The test checks that a LocalVariableTable attribute is generated for the

 * method bodies representing lambda expressions, and checks that the expected

 * set of entries is found in the attribute.

 *

 * Since the bug was about missing entries in the LVT, not malformed entries,

 * the test is not intended to be a detailed test of the contents of each

 * LocalVariableTable entry: it is assumed that if a entry is present, it

 * will have the correct contents.

 *

 * The test looks for test cases represented by nested classes whose

 * name begins with "Lambda".  Each such class contains a lambda expression

 * that will mapped into a lambda method, and because the test is compiled

 * with -g, these methods should have a LocalVariableTable.  The set of

 * expected names in the LVT is provided in an annotation on the class for

 * the test case.

 */

public class LocalVariableTable {

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

        new LocalVariableTable().run();

    }

    void run() throws Exception {

        // the declared classes are returned in an unspecified order,

        // so for neatness, sort them by name before processing them

        Class<?>[] classes = getClass().getDeclaredClasses();

        Arrays.sort(classes, (c1, c2) -> c1.getName().compareTo(c2.getName()));

        for (Class<?> c : classes) {

            if (c.getSimpleName().startsWith("Lambda"))

                check(c);

        }

        if (errors > 0)

            throw new Exception(errors + " errors found");

    }

    /** Check an individual test case. */

    void check(Class<?> c) throws Exception {

        System.err.println("Checking " + c.getSimpleName());

        Expect expect = c.getAnnotation(Expect.class);

        if (expect == null) {

            error("@Expect not found for class " + c.getSimpleName());

            return;

        }

        ClassFile cf = ClassFile.read(getClass().getResource(c.getName() + ".class").openStream());

        Method m = getLambdaMethod(cf);

        if (m == null) {

            error("lambda method not found");

            return;

        }

        Code_attribute code = (Code_attribute) m.attributes.get(Attribute.Code);

        if (code == null) {

            error("Code attribute not found");

            return;

        }

        LocalVariableTable_attribute lvt =

                (LocalVariableTable_attribute) code.attributes.get(Attribute.LocalVariableTable);

        if (lvt == null) {

            error("LocalVariableTable attribute not found");

            return;

        }

        Set<String> foundNames = new LinkedHashSet<>();

        for (LocalVariableTable_attribute.Entry e: lvt.local_variable_table) {

            foundNames.add(cf.constant_pool.getUTF8Value(e.name_index));

        }

        Set<String> expectNames = new LinkedHashSet<>(Arrays.asList(expect.value()));

        if (!foundNames.equals(expectNames)) {

            Set<String> foundOnly = new LinkedHashSet<>(foundNames);

            foundOnly.removeAll(expectNames);

            for (String s: foundOnly)

                error("Unexpected name found: " + s);

            Set<String> expectOnly = new LinkedHashSet<>(expectNames);

            expectOnly.removeAll(foundNames);

            for (String s: expectOnly)

                error("Expected name not found: " + s);

        }

    }

    /** Get a method whose name begins "lambda$...". */

    Method getLambdaMethod(ClassFile cf) throws ConstantPoolException {

        for (Method m: cf.methods) {

            if (m.getName(cf.constant_pool).startsWith("lambda$"))

                return m;

        }

        return null;

    }

    /** Report an error. */

    void error(String msg) {

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

        errors++;

    }

    int errors;

    /**

     * Annotation used to provide the set of names expected in the LVT attribute.

     */

    @Retention(RetentionPolicy.RUNTIME)

    @interface Expect {

        String[] value();

    }

    /** Functional interface with nullary method. */

    interface Run0 {

        public void run();

    }

    /** Functional interface with 1-ary method. */

    interface Run1 {

        public void run(int a0);

    }

    /** Functional interface with 2-ary method. */

    interface Run2 {

        public void run(int a0, int a1);

    }

    /*

     * ---------- Test cases ---------------------------------------------------

     */

    @Expect({ "x" })

    static class Lambda_Args0_Local1 {

        Run0 r = () -> { int x = 0; };

    }

    @Expect({ "x", "this" })

    static class Lambda_Args0_Local1_this {

        int v;

        Run0 r = () -> { int x = v; };

    }

    @Expect({ "a" })

    static class Lambda_Args1_Local0 {

        Run1 r = (a) -> { };

    }

    @Expect({ "a", "x" })

    static class Lambda_Args1_Local1 {

        Run1 r = (a) -> { int x = a; };

    }

    @Expect({ "a", "x", "v" })

    static class Lambda_Args1_Local1_Captured1 {

        void m() {

            int v = 0;

            Run1 r = (a) -> { int x = a + v; };

        }

    }

    @Expect({ "a1", "a2", "x1", "x2", "this", "v1", "v2" })

    static class Lambda_Args2_Local2_Captured2_this {

        int v;

        void m() {

            int v1 = 0;

            int v2 = 0;

            Run2 r = (a1, a2) -> {

                int x1 = a1 + v1 + v;

                int x2 = a2 + v2 + v;

            };

        }

    }

    @Expect({ "e", "c" })

    static class Lambda_Try_Catch {

        private static Runnable asUncheckedRunnable(Closeable c) {

            return () -> {

                try {

                    c.close();

                } catch (IOException e) {

                   throw new UncheckedIOException(e);

                }

            };

        }

    }

}