/*

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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.

 *

 * 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

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 */

/*

 * @test

 * @summary The LVT is not generated correctly during some try/catch scenarios

 *          javac crash while creating LVT entry for a local variable defined in

 *          an inner block

 * @library /tools/javac/lib

 * @build JavacTestingAbstractProcessor LVTHarness

 * @run main LVTHarness

 */

import java.io.File;

import java.io.IOException;

import java.lang.annotation.Annotation;

import java.util.Set;

import java.util.Arrays;

import java.util.ArrayList;

import java.util.Collections;

import java.util.HashMap;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import javax.annotation.processing.RoundEnvironment;

import javax.lang.model.element.Element;

import javax.lang.model.element.TypeElement;

import javax.tools.JavaCompiler;

import javax.tools.JavaFileObject;

import javax.tools.StandardJavaFileManager;

import javax.tools.ToolProvider;

import com.sun.source.util.JavacTask;

import com.sun.tools.classfile.Attribute;

import com.sun.tools.classfile.ClassFile;

import com.sun.tools.classfile.ConstantPool;

import com.sun.tools.classfile.ConstantPoolException;

import com.sun.tools.classfile.Code_attribute;

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

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

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

import com.sun.tools.classfile.LocalVariableTable_attribute;

import com.sun.tools.classfile.Method;

import static javax.tools.StandardLocation.*;

import static com.sun.tools.classfile.LocalVariableTable_attribute.Entry;

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

public class LVTHarness {

    static int nerrors = 0;

    static final JavaCompiler comp = ToolProvider.getSystemJavaCompiler();

    static final StandardJavaFileManager fm = comp.getStandardFileManager(null, null, null);

    public static void main(String[] args) throws Exception {

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

        fm.setLocation(SOURCE_PATH, Arrays.asList(new File(testDir, "tests")));

        // Make sure classes are written to scratch dir.

        fm.setLocation(CLASS_OUTPUT, Arrays.asList(new File(".")));

        for (JavaFileObject jfo : fm.list(SOURCE_PATH, "", Collections.singleton(SOURCE), true)) {

            new LVTHarness(jfo).check();

        }

        if (nerrors > 0) {

            throw new AssertionError("Errors were found");

        }

    }

    JavaFileObject jfo;

    Map<ElementKey, AliveRanges> aliveRangeMap = new HashMap<>();

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

    List<ElementKey> seenAliveRanges = new ArrayList<>();

    protected LVTHarness(JavaFileObject jfo) {

        this.jfo = jfo;

    }

    protected void check() throws Exception {

        JavacTask ct = (JavacTask) comp.getTask(null, fm, null, Arrays.asList("-g"),

                                                null, Arrays.asList(jfo));

        System.err.println("compiling code " + jfo);

        ct.setProcessors(Collections.singleton(new AliveRangeFinder()));

        if (!ct.call()) {

            throw new AssertionError("Error during compilation");

        }

        File javaFile = new File(jfo.getName());

        File classFile = new File(javaFile.getName().replace(".java", ".class"));

        checkClassFile(classFile);

        //check all candidates have been used up

        for (Map.Entry<ElementKey, AliveRanges> entry : aliveRangeMap.entrySet()) {

            if (!seenAliveRanges.contains(entry.getKey())) {

                error("Redundant @AliveRanges annotation on method " +

                        entry.getKey().elem + " with key " + entry.getKey());

            }

        }

    }

    void checkClassFile(File file)

            throws IOException, ConstantPoolException, InvalidDescriptor {

        ClassFile classFile = ClassFile.read(file);

        ConstantPool constantPool = classFile.constant_pool;

        //lets get all the methods in the class file.

        for (Method method : classFile.methods) {

            for (ElementKey elementKey: aliveRangeMap.keySet()) {

                String methodDesc = method.getName(constantPool) +

                        method.descriptor.getParameterTypes(constantPool).replace(" ", "");

                if (methodDesc.equals(elementKey.elem.toString())) {

                    checkMethod(constantPool, method, aliveRangeMap.get(elementKey));

                    seenAliveRanges.add(elementKey);

                }

            }

        }

    }

    void checkMethod(ConstantPool constantPool, Method method, AliveRanges ranges)

            throws InvalidIndex, UnexpectedEntry {

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

        LocalVariableTable_attribute lvt =

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

        List<String> infoFromRanges = convertToStringList(ranges);

        List<String> infoFromLVT = convertToStringList(constantPool, lvt);

        // infoFromRanges most be contained in infoFromLVT

        int i = 0;

        int j = 0;

        while (i < infoFromRanges.size() && j < infoFromLVT.size()) {

            int comparison = infoFromRanges.get(i).compareTo(infoFromLVT.get(j));

            if (comparison == 0) {

                i++; j++;

            } else if (comparison > 0) {

                j++;

            } else {

                break;

            }

        }

        if (i < infoFromRanges.size()) {

            error(infoFromLVT, infoFromRanges);

        }

    }

    List<String> convertToStringList(AliveRanges ranges) {

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

        for (Annotation anno : ranges.value()) {

            AliveRange range = (AliveRange)anno;

            String str = formatLocalVariableData(range.varName(),

                    range.bytecodeStart(), range.bytecodeLength());

            result.add(str);

        }

        Collections.sort(result);

        return result;

    }

    List<String> convertToStringList(ConstantPool constantPool,

            LocalVariableTable_attribute lvt) throws InvalidIndex, UnexpectedEntry {

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

        for (Entry entry : lvt.local_variable_table) {

            String str = formatLocalVariableData(constantPool.getUTF8Value(entry.name_index),

                    entry.start_pc, entry.length);

            result.add(str);

        }

        Collections.sort(result);

        return result;

    }

    String formatLocalVariableData(String varName, int start, int length) {

        StringBuilder sb = new StringBuilder()

                    .append("var name: ").append(varName)

                    .append(" start: ").append(start)

                    .append(" length: ").append(length);

        return sb.toString();

    }

    protected void error(List<String> infoFromLVT, List<String> infoFromRanges) {

        nerrors++;

        System.err.printf("Error occurred while checking file: %s\n", jfo.getName());

        System.err.println("The range info from the annotations is");

        printStringListToErrOutput(infoFromRanges);

        System.err.println();

        System.err.println("And the range info from the class file is");

        printStringListToErrOutput(infoFromLVT);

        System.err.println();

    }

    void printStringListToErrOutput(List<String> list) {

        for (String s : list) {

            System.err.println("\t" + s);

        }

    }

    protected void error(String msg) {

        nerrors++;

        System.err.printf("Error occurred while checking file: %s\nreason: %s\n",

                jfo.getName(), msg);

    }

    class AliveRangeFinder extends JavacTestingAbstractProcessor {

        @Override

        public boolean process(Set<? extends TypeElement> annotations,

            RoundEnvironment roundEnv) {

            if (roundEnv.processingOver())

                return true;

            TypeElement aliveRangeAnno = elements.getTypeElement("AliveRanges");

            if (!annotations.contains(aliveRangeAnno)) {

                error("no @AliveRanges annotation found in test class");

            }

            for (Element elem: roundEnv.getElementsAnnotatedWith(aliveRangeAnno)) {

                Annotation annotation = elem.getAnnotation(AliveRanges.class);

                aliveRangeMap.put(new ElementKey(elem), (AliveRanges)annotation);

            }

            return true;

        }

    }

    class ElementKey {

        String key;

        Element elem;

        public ElementKey(Element elem) {

            this.elem = elem;

            this.key = computeKey(elem);

        }

        @Override

        public boolean equals(Object obj) {

            if (obj instanceof ElementKey) {

                ElementKey other = (ElementKey)obj;

                return other.key.equals(key);

            }

            return false;

        }

        @Override

        public int hashCode() {

            return key.hashCode();

        }

        String computeKey(Element e) {

            StringBuilder buf = new StringBuilder();

            while (e != null) {

                buf.append(e.toString());

                e = e.getEnclosingElement();

            }

            buf.append(jfo.getName());

            return buf.toString();

        }

        @Override

        public String toString() {

            return "Key{" + key + "}";

        }

    }

}