001    package railo.transformer.bytecode.visitor;
002    
003    import org.objectweb.asm.Label;
004    import org.objectweb.asm.Opcodes;
005    import org.objectweb.asm.commons.GeneratorAdapter;
006    
007    import railo.transformer.bytecode.BytecodeContext;
008    import railo.transformer.bytecode.Position;
009    import railo.transformer.bytecode.util.ExpressionUtil;
010    import railo.transformer.bytecode.util.Types;
011    
012    public final class ForIntVisitor implements Opcodes, LoopVisitor {
013    
014            private Label beforeInit=new Label();
015            private Label beforeExpr=new Label(),afterExpr=new Label();
016            private Label beforeBody=new Label(),afterBody=new Label();
017            private Label beforeUpdate=new Label(),afterUpdate=new Label();
018            private int i;
019            
020            public int visitBeforeExpression(GeneratorAdapter adapter, int start, int step, boolean isLocal) {
021                    // init
022                    adapter.visitLabel(beforeInit);
023                    forInit(adapter, start, isLocal);
024                    adapter.goTo(beforeExpr);
025                    
026                    // update
027                    adapter.visitLabel(beforeUpdate);
028                    forUpdate(adapter, step, isLocal);
029                    
030                    // expression
031                    adapter.visitLabel(beforeExpr);
032                    return i;
033            }
034    
035            public void visitAfterExpressionBeginBody(GeneratorAdapter adapter) {
036                    adapter.ifZCmp(Opcodes.IFEQ, afterBody);
037            }
038            
039            public void visitEndBody(BytecodeContext bc,Position line) {
040                    bc.getAdapter().goTo(beforeUpdate);
041                    ExpressionUtil.visitLine(bc, line);
042                    bc.getAdapter().visitLabel(afterBody);
043                    //adapter.visitLocalVariable("i", "I", null, beforeInit, afterBody, i);
044            }
045    
046            
047            private void forInit(GeneratorAdapter adapter, int start, boolean isLocal) {
048                    i=adapter.newLocal(Types.INT_VALUE); 
049                    if(isLocal)adapter.loadLocal(start,Types.INT_VALUE);
050                    else adapter.push(start);
051                    adapter.visitVarInsn(ISTORE, i);
052            }
053            
054            private void forUpdate(GeneratorAdapter adapter, int step, boolean isLocal) {
055                    if(isLocal) {
056                            adapter.visitVarInsn(ILOAD, i);
057                            adapter.loadLocal(step);
058                            adapter.visitInsn(IADD);
059                            adapter.visitVarInsn(ISTORE, i);
060                    }
061                    else adapter.visitIincInsn(i, step);
062            }
063    
064            /**
065             *
066             * @see railo.transformer.bytecode.visitor.LoopVisitor#visitContinue(org.objectweb.asm.commons.GeneratorAdapter)
067             */
068            public void visitContinue(BytecodeContext bc) {
069                    bc.getAdapter().visitJumpInsn(Opcodes.GOTO, beforeUpdate);
070            }
071            
072            /**
073             *
074             * @see railo.transformer.bytecode.visitor.LoopVisitor#visitBreak(org.objectweb.asm.commons.GeneratorAdapter)
075             */
076            public void visitBreak(BytecodeContext bc) {
077                    bc.getAdapter().visitJumpInsn(Opcodes.GOTO, afterBody);
078            }
079    
080            /**
081             *
082             * @see railo.transformer.bytecode.visitor.LoopVisitor#getContinueLabel()
083             */
084            public Label getContinueLabel() {
085                    return beforeUpdate;
086            }
087    
088            /**
089             *
090             * @see railo.transformer.bytecode.visitor.LoopVisitor#getBreakLabel()
091             */
092            public Label getBreakLabel() {
093                    return afterBody;
094            }
095            
096    }