org.codehaus.groovy.classgen.asm.ExpressionAsVariableSlot Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of groovy-all Show documentation
Show all versions of groovy-all Show documentation
Groovy: A powerful, dynamic language for the JVM
/**
* 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
* @author Jochen "blackdrag" Theodorou
*/
public class ExpressionAsVariableSlot extends BytecodeExpression {
private int index = -1;
private Expression exp;
private WriterController controller;
private 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();
}
}