/*

 * Copyright (c) 1994, 2003, 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

 * questions.

 */

package sun.tools.tree;

import sun.tools.java.*;

import sun.tools.tree.*;

import java.util.Vector;

/**

 * A local Field

 *

 * WARNING: The contents of this source file are not part of any

 * supported API.  Code that depends on them does so at its own risk:

 * they are subject to change or removal without notice.

 */

public

class LocalMember extends MemberDefinition {

    /**

     * The number of the variable

     */

    int number = -1;

    /**

     * Some statistics

     */

    int readcount;

    int writecount;

    /**

     * An indication of which block the variable comes from.

     * Helps identify uplevel references.

     */

    int scopeNumber;

    /**

     * Return current nesting level, i.e., the value of 'scopeNumber'.

     * Made public for the benefit of 'ClassDefinition.resolveName'.

     */

    public int getScopeNumber() {

        return scopeNumber;

    }

    /**

     * Used by copyInline to record the original of this copy.

     */

    LocalMember originalOfCopy;

    /**

     * The previous local variable, this list is used to build a nested

     * context of local variables.

     */

    LocalMember prev;

    /**

     * Constructor

     */

    public LocalMember(long where, ClassDefinition clazz, int modifiers, Type type,

                      Identifier name) {

        super(where, clazz, modifiers, type, name, null, null);

    }

    /**

     * Constructor for a block-inner class.

     */

    public LocalMember(ClassDefinition innerClass) {

        super(innerClass);

        // The class's "real" name is something like "foo$1$bar", but locally:

        name = innerClass.getLocalName();

    }

    /**

     * Constructor for a proxy to an instance or class variable.

     */

    LocalMember(MemberDefinition field) {

        this(0, null, 0, field.getType(), idClass);

        // use this random slot to store the info:

        accessPeer = field;

    }

    /**

     * Is this a proxy for the given field?

     */

    final MemberDefinition getMember() {

        return (name == idClass) ? accessPeer : null;

    }

    /**

     * Special checks

     */

    public boolean isLocal() {

        return true;

    }

    /**

     * Make a copy of this field, which is an argument to a method

     * or constructor.  Arrange so that when occurrences of the field

     * are encountered in an immediately following copyInline() operation,

     * the expression nodes will replace the original argument by the

     * fresh copy.

     */

    public LocalMember copyInline(Context ctx) {

        LocalMember copy = new LocalMember(where, clazz, modifiers, type, name);

        copy.readcount = this.readcount;

        copy.writecount = this.writecount;

        copy.originalOfCopy = this;

        // Make a temporary link from the original.

        // It only stays valid through the next call to copyInline().

        // (This means that recursive inlining won't work.)

        // To stay honest, we mark these inline copies:

        copy.addModifiers(M_LOCAL);

        if (this.accessPeer != null

            && (this.accessPeer.getModifiers() & M_LOCAL) == 0) {

            throw new CompilerError("local copyInline");

        }

        this.accessPeer = copy;

        return copy;

    }

    /**

     * Returns the previous result of copyInline(ctx).

     * Must be called in the course of an Expression.copyInline()

     * operation that immediately follows the LocalMember.copyInline().

     * Return "this" if there is no such copy.

     */

    public LocalMember getCurrentInlineCopy(Context ctx) {

        MemberDefinition accessPeer = this.accessPeer;

        if (accessPeer != null && (accessPeer.getModifiers() & M_LOCAL) != 0) {

            LocalMember copy = (LocalMember)accessPeer;

            return copy;

        }

        return this;

    }

    /**

     * May inline copies of all the arguments of the given method.

     */

    static public LocalMember[] copyArguments(Context ctx, MemberDefinition field) {

        Vector v = field.getArguments();

        LocalMember res[] = new LocalMember[v.size()];

        v.copyInto(res);

        for (int i = 0; i < res.length; i++) {

            res[i] = res[i].copyInline(ctx);

        }

        return res;

    }

    /**

     * Call this when finished with the result of a copyArguments() call.

     */

    static public void doneWithArguments(Context ctx, LocalMember res[]) {

        for (int i = 0; i < res.length; i++) {

            if (res[i].originalOfCopy.accessPeer == res[i]) {

                res[i].originalOfCopy.accessPeer = null;

            }

        }

    }

    /**

     * Is this local variable's value stable and simple enough to be directly

     * substituted for occurrences of the variable itself?

     * (This decision is made by VarDeclarationStatement.inline().)

     */

    public boolean isInlineable(Environment env, boolean fromFinal) {

        return (getModifiers() & M_INLINEABLE) != 0;

    }

    /**

     * Check if used

     */

    public boolean isUsed() {

        return (readcount != 0) || (writecount != 0);

    }

    // Used by class Context, only on members of MemberDefinition.available:

    LocalMember getAccessVar() {

        return (LocalMember)accessPeer;

    }

    void setAccessVar(LocalMember f) {

        accessPeer = f;

    }

    // Used by class Context, only on "AccessVar" constructor args

    MemberDefinition getAccessVarMember() {

        return accessPeer;

    }

    void setAccessVarMember(MemberDefinition f) {

        accessPeer = f;

    }

    /**

     * Return value

     */

    public Node getValue(Environment env) {

        return (Expression)getValue();

    }

    /**

     * Value number for vsets, or -1 if none.

     */

    public int getNumber(Context ctx) {

        return number;

    }

}