Java LocalVariableAttribute.tableLength方法代码示例

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
/**
 * Records local variables available at the specified program counter.
 * If the LocalVariableAttribute is not available, this method does not
 * record any local variable.  It only returns false.
 *
 * @param pc    program counter (>= 0)
 * @return false if the CodeAttribute does not include a
 *              LocalVariableAttribute.
 */
public boolean recordLocalVariables(CodeAttribute ca, int pc)
    throws CompileError
{
    LocalVariableAttribute va
        = (LocalVariableAttribute)
          ca.getAttribute(LocalVariableAttribute.tag);
    if (va == null)
        return false;

    int n = va.tableLength();
    for (int i = 0; i < n; ++i) {
        int start = va.startPc(i);
        int len = va.codeLength(i);
        if (start <= pc && pc < start + len)
            gen.recordVariable(va.descriptor(i), va.variableName(i),
                               va.index(i), stable);
    }

    return true;
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
/**
 * Records parameter names if the LocalVariableAttribute is available.
 * It returns false unless the LocalVariableAttribute is available.
 *
 * @param numOfLocalVars    the number of local variables used
 *                          for storing the parameters.
 * @return false if the CodeAttribute does not include a
 *              LocalVariableAttribute.
 */
public boolean recordParamNames(CodeAttribute ca, int numOfLocalVars)
    throws CompileError
{
    LocalVariableAttribute va
        = (LocalVariableAttribute)
          ca.getAttribute(LocalVariableAttribute.tag);
    if (va == null)
        return false;

    int n = va.tableLength();
    for (int i = 0; i < n; ++i) {
        int index = va.index(i);
        if (index < numOfLocalVars)
            gen.recordVariable(va.descriptor(i), va.variableName(i),
                               index, stable);
    }

    return true;
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
private Map<Integer, String> extractNameParameter(CtMethod m) throws NotFoundException {
    Map<Integer, String> hashNameParam = new HashMap<Integer, String>();
    CodeAttribute codeAttribute = (CodeAttribute) m.getMethodInfo().getAttribute("Code");
    if (codeAttribute != null) {
        LocalVariableAttribute localVariableAttribute = (LocalVariableAttribute) codeAttribute.getAttribute("LocalVariableTable");
        if (localVariableAttribute != null && localVariableAttribute.tableLength() >= m.getParameterTypes().length) {
            for (int i = 0; i < m.getParameterTypes().length + 2; i++) {
                String name = localVariableAttribute.getConstPool().getUtf8Info(localVariableAttribute.nameIndex(i));
                if (!name.equals("this")) {
                    hashNameParam.put(i, name);
                }
            }
        }
    }
    return hashNameParam;
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
private static void dump(LocalVariableAttribute lva) {
    if (logger.isDebugEnabled()) {
        StringBuilder buffer = new StringBuilder(1024);
        for (int i = 0; i < lva.tableLength(); i++) {
            buffer.append("\n");
            buffer.append(i);
            buffer.append("  start_pc:");
            buffer.append(lva.startPc(i));
            buffer.append("  index:");
            buffer.append(lva.index(i));
            buffer.append("  name:");
            buffer.append(lva.variableName(i));
            buffer.append("  nameIndex:");
            buffer.append(lva.nameIndex(i));
        }
        logger.debug(buffer.toString());
    }
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
@Override
public LocalVariableTable getLocalVariableTable(Signature methodSignature) 
throws MethodNotFoundException, MethodCodeNotFoundException  {
    final CodeAttribute ca = getMethodCodeAttribute(methodSignature);
    final LocalVariableAttribute lvtJA = (LocalVariableAttribute) ca.getAttribute("LocalVariableTable");

    if (lvtJA == null) {
        return this.defaultLocalVariableTable(methodSignature);
    }

    //builds the local variable table from the LocalVariableTable attribute 
    //information; this has always success
    final LocalVariableTable lvt = new LocalVariableTable(ca.getMaxLocals());
    for (int i = 0; i < lvtJA.tableLength(); ++i) {
        lvt.setEntry(lvtJA.index(i), lvtJA.descriptor(i), 
                     lvtJA.variableName(i), lvtJA.startPc(i),  lvtJA.codeLength(i));
    }
    return lvt;
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
@Override
public void scan(Object cls) {
    final MetadataAdapter md = getMetadataAdapter();

    for (Object method : md.getMethods(cls)) {
        String key = md.getMethodFullKey(cls, method);
        if (acceptResult(key)) {
            LocalVariableAttribute table = (LocalVariableAttribute) ((MethodInfo) method).getCodeAttribute().getAttribute(LocalVariableAttribute.tag);
            int length = table.tableLength();
            int i = Modifier.isStatic(((MethodInfo) method).getAccessFlags()) ? 0 : 1; //skip this
            if (i < length) {
                List<String> names = new ArrayList<String>(length - i);
                while (i < length) names.add(((MethodInfo) method).getConstPool().getUtf8Info(table.nameIndex(i++)));
                getStore().put(key, Joiner.on(", ").join(names));
            }
        }
    }
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
/**
 * 
 * @param reifiedMethod a method that has some parameters 
 * @param parameterName the name of the parameters 
 * @return the index of the parameters in the list of parameters (first parameter has index 1)
 */
private static int parameterNameToIndex(CtMethod reifiedMethod, String parameterName) {
    CodeAttribute codeAttribute = (CodeAttribute) reifiedMethod.getMethodInfo().getAttribute(
            CodeAttribute.tag);
    LocalVariableAttribute localVariableAttribute = (LocalVariableAttribute) codeAttribute
            .getAttribute(LocalVariableAttribute.tag);
    for (int j = 0; j < localVariableAttribute.tableLength(); j++) {
        String name = localVariableAttribute.getConstPool().getUtf8Info(
                localVariableAttribute.nameIndex(j));
        if (!name.equals("this")) {
            if (name.equals(parameterName)) {
                return j;
            }
        }
    }
    throw new RuntimeException("parameter " + parameterName + "not found in method " +
        reifiedMethod.getLongName());
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
@SuppressWarnings("unused")
private void dumpTable(LocalVariableAttribute table) {
	for (int i=0; i<table.tableLength(); i++) {
		System.out.println(String.format("\t%d (%d): %s %s",
			i, table.index(i), table.variableName(i), table.descriptor(i)
		));
	}
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
private void renameLVT(BehaviorEntry behaviorEntry, ConstPool constants, LocalVariableAttribute table) {
	
	// skip empty tables
	if (table.tableLength() <= 0) {
		return;
	}
	
	// where do we start counting variables?
	int starti = 0;
	if (table.variableName(0).equals("this")) {
		// skip the "this" variable
		starti = 1;
	}
	
	// rename method arguments first
	int numArgs = 0;
	if (behaviorEntry.getSignature() != null) {
		numArgs = behaviorEntry.getSignature().getArgumentTypes().size();
		for (int i=starti; i<starti + numArgs && i<table.tableLength(); i++) {
			int argi = i - starti;
			String argName = m_translator.translate(new ArgumentEntry(behaviorEntry, argi, ""));
			if (argName == null) {
				argName = "a" + (argi + 1);
			}
			renameVariable(table, i, constants.addUtf8Info(argName));
		}
	}
	
	// then rename the rest of the args, if any
	for (int i=starti + numArgs; i<table.tableLength(); i++) {
		int firstIndex = table.index(starti + numArgs);
		renameVariable(table, i, constants.addUtf8Info("v" + (table.index(i) - firstIndex + 1)));
	}
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
private int getNameIndex(LocalVariableAttribute table, int index) {
	for (int i=0; i<table.tableLength(); i++) {
		if (table.index(i) == index) {
			return table.nameIndex(i);
		}
	}
	return 0;
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
/**
 * 获取方法的参数名称.
 * 
 * @param ctMethod
 * @return
 * @throws NotFoundException
 */
public static String[] getParameterNames(CtMethod ctMethod) throws NotFoundException {
	MethodInfo methodInfo = ctMethod.getMethodInfo();
	CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
	// logger.info("methodInfo.getConstPool().getSize():");
	LocalVariableAttribute attribute = (LocalVariableAttribute) codeAttribute.getAttribute(LocalVariableAttribute.tag);
	// String[] names = new String[attribute.tableLength() - 1];
	String[] paramNames = new String[ctMethod.getParameterTypes().length];

	int pos = 0;
	if (true) {
		int size = attribute.tableLength();
		if (size > 0) {
			String[] names = new String[size - 1];
			for (int i = 0; i < names.length; i++) {
				names[i] = attribute.variableName(i);
				if ("this".equals(names[i])) {
					pos = i + 1;
					break;
				}
			}
			// logger.info(methodInfo.getName() + " pos:" + pos + " allNames:" + StringUtils.join(names, ", "));
		}
	}

	// logger.info(methodInfo.getName() + " pos:" + pos);
	for (int i = 0; i < paramNames.length; i++) {
		// paramNames[i] = attribute.variableName(i + 1);
		try {
			paramNames[i] = attribute.variableName(i + pos);
			// logger.info("paramNames[" + i + "]:" + paramNames[i]);
		}
		catch (RuntimeException e) {
			throw e;
		}
	}
	// System.err.println("paramNames:" + StringUtils.join(paramNames));
	return paramNames;
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
private void renameLVT(BehaviorEntry behaviorEntry, ConstPool constants,
	LocalVariableAttribute table)
{
	
	// skip empty tables
	if(table.tableLength() <= 0)
		return;
	
	// where do we start counting variables?
	int starti = 0;
	if(table.variableName(0).equals("this"))
		// skip the "this" variable
		starti = 1;
	
	// rename method arguments first
	int numArgs = 0;
	if(behaviorEntry.getSignature() != null)
	{
		numArgs = behaviorEntry.getSignature().getArgumentTypes().size();
		for(int i = starti; i < starti + numArgs && i < table.tableLength(); i++)
		{
			int argi = i - starti;
			String argName =
				m_translator.translate(new ArgumentEntry(behaviorEntry,
					argi, ""));
			if(argName == null)
				argName = "a" + (argi + 1);
			renameVariable(table, i, constants.addUtf8Info(argName));
		}
	}
	
	// then rename the rest of the args, if any
	for(int i = starti + numArgs; i < table.tableLength(); i++)
	{
		int firstIndex = table.index(starti + numArgs);
		renameVariable(table, i,
			constants.addUtf8Info("v" + (table.index(i) - firstIndex + 1)));
	}
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
private int getNameIndex(LocalVariableAttribute table, int index)
{
	for(int i = 0; i < table.tableLength(); i++)
		if(table.index(i) == index)
			return table.nameIndex(i);
	return 0;
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
public static List<String> lookupParameterNames(Constructor constructor) {
    try {
        List<String> parameters = new ArrayList<String>();

        ClassPool classPool = newClassPool();
        CtClass ctClass = classPool.get(constructor.getDeclaringClass().getName());
        CtClass[] cc = new CtClass[constructor.getParameterTypes().length];
        for (int i = 0; i < constructor.getParameterTypes().length; i++) {
            cc[i] = classPool.get(constructor.getParameterTypes()[i].getName());
        }
        CtConstructor ctConstructor = ctClass.getDeclaredConstructor(cc);

        // Signatures names
        CodeAttribute codeAttribute = (CodeAttribute) ctConstructor.getMethodInfo().getAttribute("Code");
        if (codeAttribute != null) {
            LocalVariableAttribute localVariableAttribute = (LocalVariableAttribute) codeAttribute.getAttribute("LocalVariableTable");
            if (localVariableAttribute != null && localVariableAttribute.tableLength() >= ctConstructor.getParameterTypes().length) {
                for (int i = 0; i < ctConstructor.getParameterTypes().length + 1; i++) {
                    String name = localVariableAttribute.getConstPool().getUtf8Info(localVariableAttribute.nameIndex(i));
                    if (!name.equals("this")) {
                        parameters.add(name);
                    }
                }
            }
        }

        return parameters;
    } catch (Exception e) {
        throw new UnexpectedException("Cannot extract parameter names", e);
    }
}
 

import javassist.bytecode.LocalVariableAttribute; //导入方法依赖的package包/类
public static String[] getParameterVariableName(CtBehavior method, LocalVariableAttribute localVariableAttribute) {
    // Inspired by
    // http://www.jarvana.com/jarvana/view/org/jboss/weld/servlet/weld-servlet/1.0.1-Final/weld-servlet-1.0.1-Final-sources.jar!/org/slf4j/instrumentation/JavassistHelper.java?format=ok
    // http://grepcode.com/file/repo1.maven.org/maven2/jp.objectfanatics/assertion-weaver/0.0.30/jp/objectfanatics/commons/javassist/JavassistUtils.java
    if (localVariableAttribute == null) {
        // null means that the class is not compiled with debug option.
        return null;
    }

    dump(localVariableAttribute);
    String[] parameterTypes = JavaAssistUtils.parseParameterSignature(method.getSignature());
    if (parameterTypes.length == 0) {
        return EMPTY_STRING_ARRAY;
    }
    String[] parameterVariableNames = new String[parameterTypes.length];
    boolean thisExist = thisExist(method);

    int paramIndex = 0;
    for (int i = 0; i < localVariableAttribute.tableLength(); i++) {
        // if start pc is not 0, it's not a parameter.
        if (localVariableAttribute.startPc(i) != 0) {
            continue;
        }
        int index = localVariableAttribute.index(i);
        if (index == 0 && thisExist) {
            // variable this. skip.
            continue;
        }
        String variablename = localVariableAttribute.variableName(i);
        parameterVariableNames[paramIndex++] = variablename;
        
        if (paramIndex == parameterTypes.length) {
            break;
        }
    }
    return parameterVariableNames;
}