/*

 * Copyright (c) 1998, 2017, 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.  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,

 * 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

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 */

package com.sun.tools.jdi;

import com.sun.jdi.AbsentInformationException;

import com.sun.jdi.ClassNotLoadedException;

import com.sun.jdi.InternalException;

import com.sun.jdi.LocalVariable;

import com.sun.jdi.Location;

import com.sun.jdi.Method;

import com.sun.jdi.StackFrame;

import com.sun.jdi.Type;

import com.sun.jdi.VirtualMachine;

public class LocalVariableImpl extends MirrorImpl

                               implements LocalVariable, ValueContainer

{

    private final Method method;

    private final int slot;

    private final Location scopeStart;

    private final Location scopeEnd;

    private final String name;

    private final String signature;

    private String genericSignature = null;

    LocalVariableImpl(VirtualMachine vm, Method method,

                      int slot, Location scopeStart, Location scopeEnd,

                      String name, String signature,

                      String genericSignature) {

        super(vm);

        this.method = method;

        this.slot = slot;

        this.scopeStart = scopeStart;

        this.scopeEnd = scopeEnd;

        this.name = name;

        this.signature = signature;

        if (genericSignature != null && genericSignature.length() > 0) {

            this.genericSignature = genericSignature;

        } else {

            // The Spec says to return null for non-generic types

            this.genericSignature = null;

        }

    }

    public boolean equals(Object obj) {

        if ((obj != null) && (obj instanceof LocalVariableImpl)) {

            LocalVariableImpl other = (LocalVariableImpl)obj;

            return ((slot() == other.slot()) &&

                    (scopeStart != null) &&

                    (scopeStart.equals(other.scopeStart)) &&

                    (super.equals(obj)));

        } else {

            return false;

        }

    }

    public int hashCode() {

        /*

         * TO DO: Better hash code

         */

        return ((scopeStart.hashCode() << 4) + slot());

    }

    public int compareTo(LocalVariable object) {

        LocalVariableImpl other = (LocalVariableImpl)object;

        int rc = scopeStart.compareTo(other.scopeStart);

        if (rc == 0) {

            rc = slot() - other.slot();

        }

        return rc;

    }

    public String name() {

        return name;

    }

    /**

     * @return a text representation of the declared type

     * of this variable.

     */

    public String typeName() {

        JNITypeParser parser = new JNITypeParser(signature);

        return parser.typeName();

    }

    public Type type() throws ClassNotLoadedException {

        return findType(signature());

    }

    public Type findType(String signature) throws ClassNotLoadedException {

        ReferenceTypeImpl enclosing = (ReferenceTypeImpl)method.declaringType();

        return enclosing.findType(signature);

    }

    public String signature() {

        return signature;

    }

    public String genericSignature() {

        return genericSignature;

    }

    public boolean isVisible(StackFrame frame) {

        validateMirror(frame);

        Method frameMethod = frame.location().method();

        if (!frameMethod.equals(method)) {

            throw new IllegalArgumentException(

                       "frame method different than variable's method");

        }

        // this is here to cover the possibility that we will

        // allow LocalVariables for native methods.  If we do

        // so we will have to re-examinine this.

        if (frameMethod.isNative()) {

            return false;

        }

        return ((scopeStart.compareTo(frame.location()) <= 0)

             && (scopeEnd.compareTo(frame.location()) >= 0));

    }

    public boolean isArgument() {

        try {

            MethodImpl method = (MethodImpl)scopeStart.method();

            return (slot < method.argSlotCount());

        } catch (AbsentInformationException e) {

            // If this variable object exists, there shouldn't be absent info

            throw new InternalException();

        }

    }

    int slot() {

        return slot;

    }

    /*

     * Compilers/VMs can have byte code ranges for variables of the

     * same names that overlap. This is because the byte code ranges

     * aren't necessarily scopes; they may have more to do with the

     * lifetime of the variable's slot, depending on implementation.

     *

     * This method determines whether this variable hides an

     * identically named variable; ie, their byte code ranges overlap

     * this one starts after the given one. If it returns true this

     * variable should be preferred when looking for a single variable

     * with its name when both variables are visible.

     */

    boolean hides(LocalVariable other) {

        LocalVariableImpl otherImpl = (LocalVariableImpl)other;

        if (!method.equals(otherImpl.method) ||

            !name.equals(otherImpl.name)) {

            return false;

        } else {

            return (scopeStart.compareTo(otherImpl.scopeStart) > 0);

        }

    }

    public String toString() {

       return name() + " in " + method.toString() +

              "@" + scopeStart.toString();

    }

}