/* * 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 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. */publicclass 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(";");        }    }}