/*

 * 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

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 */

package sun.tools.tree;

import sun.tools.java.*;

import sun.tools.asm.Assembler;

import sun.tools.asm.Label;

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 WhileStatement extends Statement {

    Expression cond;

    Statement body;

    /**

     * Constructor

     */

    public WhileStatement(long where, Expression cond, Statement body) {

        super(WHILE, where);

        this.cond = cond;

        this.body = body;

    }

    /**

     * Check a while statement

     */

    Vset check(Environment env, Context ctx, Vset vset, Hashtable exp) {

        checkLabel(env, ctx);

        CheckContext newctx = new CheckContext(ctx, this);

        // remember what was unassigned on entry

        Vset vsEntry = vset.copy();

        // check the condition.  Determine which variables have values if

        // it returns true or false.

        ConditionVars cvars =

              cond.checkCondition(env, newctx, reach(env, vset), exp);

        cond = convert(env, newctx, Type.tBoolean, cond);

        // check the body, given that the condition returned true.

        vset = body.check(env, newctx, cvars.vsTrue, exp);

        vset = vset.join(newctx.vsContinue);

        // make sure the back-branch fits the entry of the loop

        ctx.checkBackBranch(env, this, vsEntry, vset);

        // Exit the while loop by testing false or getting a break statement

        vset = newctx.vsBreak.join(cvars.vsFalse);

        return ctx.removeAdditionalVars(vset);

    }

    /**

     * Inline

     */

    public Statement inline(Environment env, Context ctx) {

        ctx = new Context(ctx, this);

        cond = cond.inlineValue(env, ctx);

        if (body != null) {

            body = body.inline(env, ctx);

        }

        return this;

    }

    /**

     * The cost of inlining this statement

     */

    public int costInline(int thresh, Environment env, Context ctx) {

        return 1 + cond.costInline(thresh, env, ctx)

                 + ((body != null) ? body.costInline(thresh, env, ctx) : 0);

    }

    /**

     * Create a copy of the statement for method inlining

     */

    public Statement copyInline(Context ctx, boolean valNeeded) {

        WhileStatement s = (WhileStatement)clone();

        s.cond = cond.copyInline(ctx);

        if (body != null) {

            s.body = body.copyInline(ctx, valNeeded);

        }

        return s;

    }

    /**

     * Code

     */

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

        CodeContext newctx = new CodeContext(ctx, this);

        asm.add(where, opc_goto, newctx.contLabel);

        Label l1 = new Label();

        asm.add(l1);

        if (body != null) {

            body.code(env, newctx, asm);

        }

        asm.add(newctx.contLabel);

        cond.codeBranch(env, newctx, asm, l1, true);

        asm.add(newctx.breakLabel);

    }

    /**

     * Print

     */

    public void print(PrintStream out, int indent) {

        super.print(out, indent);

        out.print("while ");

        cond.print(out);

        if (body != null) {

            out.print(" ");

            body.print(out, indent);

        } else {

            out.print(";");

        }

    }

}