/*
 * 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.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 CommaExpression extends BinaryExpression {
    /**
     * constructor
     */
    public CommaExpression(long where, Expression left, Expression right) {
        super(COMMA, where, (right != null) ? right.type : Type.tVoid, left, right);
    }

    /**
     * Check void expression
     */
    public Vset check(Environment env, Context ctx, Vset vset, Hashtable exp) {
        vset = left.check(env, ctx, vset, exp);
        vset = right.check(env, ctx, vset, exp);
        return vset;
    }

    /**
     * Select the type
     */
    void selectType(Environment env, Context ctx, int tm) {
        type = right.type;
    }

    /**
     * Simplify
     */
    Expression simplify() {
        if (left == null) {
            return right;
        }
        if (right == null) {
            return left;
        }
        return this;
    }

    /**
     * Inline
     */
    public Expression inline(Environment env, Context ctx) {
        if (left != null) {
            left = left.inline(env, ctx);
        }
        if (right != null) {
            right = right.inline(env, ctx);
        }
        return simplify();
    }
    public Expression inlineValue(Environment env, Context ctx) {
        if (left != null) {
            left = left.inline(env, ctx);
        }
        if (right != null) {
            right = right.inlineValue(env, ctx);
        }
        return simplify();
    }

    /**
     * Code
     */
    int codeLValue(Environment env, Context ctx, Assembler asm) {
        if (right == null) {
            // throw an appropriate error
            return super.codeLValue(env, ctx, asm);
        } else {
            // Fully code the left-hand side.  Do the LValue part of the
            // right-hand side now.  The remainder will be done by codeLoad or
            // codeStore
            if (left != null) {
                left.code(env, ctx, asm);
            }
            return right.codeLValue(env, ctx, asm);
        }
    }

    void codeLoad(Environment env, Context ctx, Assembler asm) {
        // The left-hand part has already been handled by codeLValue.

        if (right == null) {
            // throw an appropriate error
            super.codeLoad(env, ctx, asm);
        } else {
            right.codeLoad(env, ctx, asm);
        }
    }

    void codeStore(Environment env, Context ctx, Assembler asm) {
        // The left-hand part has already been handled by codeLValue.
        if (right == null) {
            // throw an appropriate error
            super.codeStore(env, ctx, asm);
        } else {
            right.codeStore(env, ctx, asm);
        }
    }

    public void codeValue(Environment env, Context ctx, Assembler asm) {
        if (left != null) {
            left.code(env, ctx, asm);
        }
        right.codeValue(env, ctx, asm);
    }
    public void code(Environment env, Context ctx, Assembler asm) {
        if (left != null) {
            left.code(env, ctx, asm);
        }
        if (right != null) {
            right.code(env, ctx, asm);
        }
    }
}