/*

 * 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.asm.Assembler;

import java.io.PrintStream;

import java.util.Hashtable;

/**

 * 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 ThisExpression extends Expression {

    LocalMember field;

    Expression implementation;

    Expression outerArg;

    /**

     * Constructor

     */

    public ThisExpression(long where) {

        super(THIS, where, Type.tObject);

    }

    protected ThisExpression(int op, long where) {

        super(op, where, Type.tObject);

    }

    public ThisExpression(long where, LocalMember field) {

        super(THIS, where, Type.tObject);

        this.field = field;

        field.readcount++;

    }

    public ThisExpression(long where, Context ctx) {

        super(THIS, where, Type.tObject);

        field = ctx.getLocalField(idThis);

        field.readcount++;

    }

    /**

     * Constructor for "x.this()"

     */

    public ThisExpression(long where, Expression outerArg) {

        this(where);

        this.outerArg = outerArg;

    }

    public Expression getImplementation() {

        if (implementation != null)

            return implementation;

        return this;

    }

    /**

     * From the 'this' in an expression of the form outer.this(...),

     * or the 'super' in an expression of the form outer.super(...),

     * return the "outer" expression, or null if there is none.

     */

    public Expression getOuterArg() {

        return outerArg;

    }

    /**

     * Check expression

     */

    public Vset checkValue(Environment env, Context ctx, Vset vset, Hashtable<Object, Object> exp) {

        if (ctx.field.isStatic()) {

            env.error(where, "undef.var", opNames[op]);

            type = Type.tError;

            return vset;

        }

        if (field == null) {

            field = ctx.getLocalField(idThis);

            field.readcount++;

        }

        if (field.scopeNumber < ctx.frameNumber) {

            // get a "this$C" copy via the current object

            implementation = ctx.makeReference(env, field);

        }

        if (!vset.testVar(field.number)) {

            env.error(where, "access.inst.before.super", opNames[op]);

        }

        if (field == null) {

            type = ctx.field.getClassDeclaration().getType();

        } else {

            type = field.getType();

        }

        return vset;

    }

    public boolean isNonNull() {

        return true;

    }

    // A 'ThisExpression' node can never appear on the LHS of an assignment in a correct

    // program, but handle this case anyhow to provide a safe error recovery.

    public FieldUpdater getAssigner(Environment env, Context ctx) {

        return null;

    }

    public FieldUpdater getUpdater(Environment env, Context ctx) {

        return null;

    }

    /**

     * Inline

     */

    public Expression inlineValue(Environment env, Context ctx) {

        if (implementation != null)

            return implementation.inlineValue(env, ctx);

        if (field != null && field.isInlineable(env, false)) {

            Expression e = (Expression)field.getValue(env);

            //System.out.println("INLINE = "+ e + ", THIS");

            if (e != null) {

                e = e.copyInline(ctx);

                e.type = type;  // in case op==SUPER

                return e;

            }

        }

        return this;

    }

    /**

     * Create a copy of the expression for method inlining

     */

    public Expression copyInline(Context ctx) {

        if (implementation != null)

            return implementation.copyInline(ctx);

        ThisExpression e = (ThisExpression)clone();

        if (field == null) {

            // The expression is copied into the context of a method

            e.field = ctx.getLocalField(idThis);

            e.field.readcount++;

        } else {

            e.field = field.getCurrentInlineCopy(ctx);

        }

        if (outerArg != null) {

            e.outerArg = outerArg.copyInline(ctx);

        }

        return e;

    }

    /**

     * Code

     */

    public void codeValue(Environment env, Context ctx, Assembler asm) {

        asm.add(where, opc_aload, field.number);

    }

    /**

     * Print

     */

    public void print(PrintStream out) {

        if (outerArg != null) {

            out.print("(outer=");

            outerArg.print(out);

            out.print(" ");

        }

        String pfx = (field == null) ? ""

            : field.getClassDefinition().getName().getFlatName().getName()+".";

        pfx += opNames[op];

        out.print(pfx + "#" + ((field != null) ? field.hashCode() : 0));

        if (outerArg != null)

            out.print(")");

    }

}