org.jboss.weld.util.bytecode.BytecodeUtils Maven / Gradle / Ivy
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* JBoss, Home of Professional Open Source
* Copyright 2008, Red Hat, Inc., and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* Licensed 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.jboss.weld.util.bytecode;
import org.jboss.classfilewriter.code.CodeAttribute;
/**
* utility class for common bytecode operations
*
* @author Stuart Douglas
*/
public class BytecodeUtils {
public static final String VOID_CLASS_DESCRIPTOR = "V";
public static final String BYTE_CLASS_DESCRIPTOR = "B";
public static final String CHAR_CLASS_DESCRIPTOR = "C";
public static final String DOUBLE_CLASS_DESCRIPTOR = "D";
public static final String FLOAT_CLASS_DESCRIPTOR = "F";
public static final String INT_CLASS_DESCRIPTOR = "I";
public static final String LONG_CLASS_DESCRIPTOR = "J";
public static final String SHORT_CLASS_DESCRIPTOR = "S";
public static final String BOOLEAN_CLASS_DESCRIPTOR = "Z";
private static final String TYPE = "TYPE";
private static final String LJAVA_LANG_CLASS = "Ljava/lang/Class;";
public static final int ENUM = 0x00004000;
public static final int ANNOTATION = 0x00002000;
private BytecodeUtils() {
}
/**
* Adds the correct load instruction based on the type descriptor
*
* @param code the bytecode to add the instruction to
* @param type the type of the variable
* @param variable the variable number
*/
public static void addLoadInstruction(CodeAttribute code, String type, int variable) {
char tp = type.charAt(0);
if (tp != 'L' && tp != '[') {
// we have a primitive type
switch (tp) {
case 'J':
code.lload(variable);
break;
case 'D':
code.dload(variable);
break;
case 'F':
code.fload(variable);
break;
default:
code.iload(variable);
}
} else {
code.aload(variable);
}
}
/**
* Pushes a class type onto the stack from the string representation This can
* also handle primitives
*
* @param b the bytecode
* @param classType the type descriptor for the class or primitive to push.
* This will accept both the java.lang.Object form and the
* Ljava/lang/Object; form
*/
public static void pushClassType(CodeAttribute b, String classType) {
if (classType.length() != 1) {
if (classType.startsWith("L") && classType.endsWith(";")) {
classType = classType.substring(1, classType.length() - 1);
}
b.loadClass(classType);
} else {
char type = classType.charAt(0);
switch (type) {
case 'I':
b.getstatic(Integer.class.getName(), TYPE, LJAVA_LANG_CLASS);
break;
case 'J':
b.getstatic(Long.class.getName(), TYPE, LJAVA_LANG_CLASS);
break;
case 'S':
b.getstatic(Short.class.getName(), TYPE, LJAVA_LANG_CLASS);
break;
case 'F':
b.getstatic(Float.class.getName(), TYPE, LJAVA_LANG_CLASS);
break;
case 'D':
b.getstatic(Double.class.getName(), TYPE, LJAVA_LANG_CLASS);
break;
case 'B':
b.getstatic(Byte.class.getName(), TYPE, LJAVA_LANG_CLASS);
break;
case 'C':
b.getstatic(Character.class.getName(), TYPE, LJAVA_LANG_CLASS);
break;
case 'Z':
b.getstatic(Boolean.class.getName(), TYPE, LJAVA_LANG_CLASS);
break;
default:
throw new RuntimeException("Cannot handle primitive type: " + type);
}
}
}
public static String getName(String descriptor) {
if (!descriptor.startsWith("[")) {
return descriptor.substring(1).substring(0, descriptor.length() - 2);
}
return descriptor;
}
}