| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.codehaus.groovy.classgen.asm; |
| |
| import org.codehaus.groovy.GroovyBugError; |
| import org.codehaus.groovy.ast.expr.Expression; |
| import org.codehaus.groovy.classgen.BytecodeExpression; |
| import org.objectweb.asm.MethodVisitor; |
| |
| /** |
| * Helper class that takes an Expression and if visited will load it normally, |
| * storing the result in a helper variable, which then can be requested after |
| * the visit is completed. A copy of the variable will stay on the stack. |
| * Subsequent visits will load the stored value instead of visiting the |
| * expression again |
| */ |
| public class ExpressionAsVariableSlot extends BytecodeExpression { |
| private int index = -1; |
| private final Expression exp; |
| private final WriterController controller; |
| private final String name; |
| |
| public ExpressionAsVariableSlot(WriterController controller, Expression expression, String name) { |
| this.exp = expression; |
| this.controller = controller; |
| this.name = name; |
| } |
| |
| public ExpressionAsVariableSlot(WriterController controller, Expression expression) { |
| this(controller, expression, "ExpressionAsVariableSlot_TEMP"); |
| } |
| |
| @Override |
| public void visit(MethodVisitor mv) { |
| OperandStack os = controller.getOperandStack(); |
| if (index == -1) { // first visit |
| // visit expression |
| exp.visit(controller.getAcg()); |
| // make copy & set type |
| os.dup(); |
| this.setType(os.getTopOperand()); |
| // store copy in temporary variable |
| CompileStack compileStack = controller.getCompileStack(); |
| index = compileStack.defineTemporaryVariable(name, getType(), true); |
| } else { |
| os.load(getType(), index); |
| } |
| // since the calling code will push the type again, we better remove it here |
| os.remove(1); |
| } |
| |
| /** |
| * returns the index of the bytecode variable |
| */ |
| public int getIndex() { |
| if (index == -1) throw new GroovyBugError("index requested before visit!"); |
| return index; |
| } |
| |
| @Override |
| public String getText() { |
| return exp.getText(); |
| } |
| } |