001/**
002 *
003 * Copyright (c) 2014, the Railo Company Ltd. All rights reserved.
004 *
005 * This library is free software; you can redistribute it and/or
006 * modify it under the terms of the GNU Lesser General Public
007 * License as published by the Free Software Foundation; either 
008 * version 2.1 of the License, or (at your option) any later version.
009 * 
010 * This library is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013 * Lesser General Public License for more details.
014 * 
015 * You should have received a copy of the GNU Lesser General Public 
016 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
017 * 
018 **/
019package lucee.transformer.bytecode.visitor;
020
021import lucee.transformer.bytecode.BytecodeContext;
022import lucee.transformer.bytecode.Position;
023import lucee.transformer.bytecode.util.ExpressionUtil;
024
025import org.objectweb.asm.Label;
026import org.objectweb.asm.Opcodes;
027
028public final class WhileVisitor implements LoopVisitor {
029
030        private Label begin;
031        private Label end;
032
033        public void visitBeforeExpression(BytecodeContext bc) {
034                begin = new Label();
035                end = new Label();              
036                bc.getAdapter().visitLabel(begin);
037        }
038
039        public void visitAfterExpressionBeforeBody(BytecodeContext bc) {
040                bc.getAdapter().ifZCmp(Opcodes.IFEQ, end);
041        }
042
043        public void visitAfterBody(BytecodeContext bc,Position endline) {
044                bc.getAdapter().visitJumpInsn(Opcodes.GOTO, begin);
045                bc.getAdapter().visitLabel(end);
046                ExpressionUtil.visitLine(bc, endline);
047        }
048
049        /**
050         *
051         * @see lucee.transformer.bytecode.visitor.LoopVisitor#visitContinue(org.objectweb.asm.commons.GeneratorAdapter)
052         */
053        public void visitContinue(BytecodeContext bc) {
054                bc.getAdapter().visitJumpInsn(Opcodes.GOTO, begin);
055        }
056        
057        /**
058         *
059         * @see lucee.transformer.bytecode.visitor.LoopVisitor#visitBreak(org.objectweb.asm.commons.GeneratorAdapter)
060         */
061        public void visitBreak(BytecodeContext bc) {
062                bc.getAdapter().visitJumpInsn(Opcodes.GOTO, end);
063        }
064
065        /**
066         *
067         * @see lucee.transformer.bytecode.visitor.LoopVisitor#getContinueLabel()
068         */
069        public Label getContinueLabel() {
070                return begin;
071        }
072
073        /**
074         *
075         * @see lucee.transformer.bytecode.visitor.LoopVisitor#getBreakLabel()
076         */
077        public Label getBreakLabel() {
078                return end;
079        }
080
081}