Examples with MethodInfo javassist.bytecode.MethodInfo used on opensource projects

Example 26 with MethodInfo

use of javassist.bytecode.MethodInfo in project openj9 by eclipse.

the class DummyClassGenerator method modifyInvokerOperand.

/*
	 * This method is to workaround a limitation of ASM which prevents
	 * generating class file where invokeinterface and invoke[static|special]
	 * bytecodes share same constant pool entry.
	 * 
	 * To overcome this limitation, after the ASM has generated class data, the
	 * operand of invoke[static|special] bytecodes is modified to be same as the
	 * operand of invokeinterface bytecode. It uses javassist APIs to make this
	 * modification.
	 */
protected byte[] modifyInvokerOperand() throws Exception {
    int cpIndex = 0;
    ByteArrayInputStream bais = new ByteArrayInputStream(data);
    ClassFile classFile = new ClassFile(new DataInputStream(bais));
    String[] sharedInvokers = (String[]) characteristics.get(SHARED_INVOKERS);
    /* Record operand of invokeinterface in invokeInterface() */
    for (int i = 0; i < sharedInvokers.length; i++) {
        String methodName = sharedInvokers[i];
        if (methodName.equals(INVOKE_INTERFACE)) {
            MethodInfo methodInfo = classFile.getMethod(methodName);
            CodeIterator ci = methodInfo.getCodeAttribute().iterator();
            while (ci.hasNext()) {
                int bcIndex = ci.next();
                int bc = ci.byteAt(bcIndex);
                if (bc == Opcode.INVOKEINTERFACE) {
                    /* found invokeinterfce bytecode */
                    cpIndex = ci.s16bitAt(bcIndex + 1);
                    break;
                }
            }
        }
    }
    /*
		 * Modify operand of invokestatic/invokespecial to cpIndex recorded
		 * above
		 */
    for (int i = 0; i < sharedInvokers.length; i++) {
        String methodName = sharedInvokers[i];
        if (methodName.equals(INVOKE_SPECIAL) || (methodName.equals(INVOKE_STATIC))) {
            MethodInfo methodInfo = classFile.getMethod(methodName);
            CodeIterator ci = methodInfo.getCodeAttribute().iterator();
            while (ci.hasNext()) {
                int bcIndex = ci.next();
                int bc = ci.byteAt(bcIndex);
                if ((bc == Opcode.INVOKESPECIAL) || (bc == Opcode.INVOKESTATIC)) {
                    /*
						 * found invokespecial or invokestatic bytecode; update
						 * the operand constant pool index
						 */
                    ci.write16bit(cpIndex, bcIndex + 1);
                }
            }
        }
    }
    ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
    DataOutputStream dataStream = new DataOutputStream(byteStream);
    classFile.write(dataStream);
    return byteStream.toByteArray();
}

Example 27 with MethodInfo

use of javassist.bytecode.MethodInfo in project openj9 by eclipse.

the class SharedInvokersTestGenerator method modifyInvokerOperand.

/*
	 * This method is to workaround a limitation of ASM which prevents
	 * generating class file where invokeinterface and invoke[static|special]
	 * bytecodes share same constant pool entry.
	 * 
	 * To overcome this limitation, after the ASM has generated class data, the
	 * operand of invoke[static|special] bytecodes is modified to be same as the
	 * operand of invokeinterface bytecode. It uses javassist APIs to make this
	 * modification.
	 */
public static byte[] modifyInvokerOperand(byte[] data) throws Exception {
    int cpIndex = 0;
    ByteArrayInputStream bais = new ByteArrayInputStream(data);
    ClassFile classFile = new ClassFile(new DataInputStream(bais));
    /* Record operand of invokeinterface in sharedInvokers() */
    MethodInfo methodInfo = classFile.getMethod("sharedInvokers");
    CodeIterator ci = methodInfo.getCodeAttribute().iterator();
    while (ci.hasNext()) {
        int bcIndex = ci.next();
        int bc = ci.byteAt(bcIndex);
        if (bc == Opcode.INVOKEINTERFACE) {
            /* found invokeinterfce bytecode */
            cpIndex = ci.s16bitAt(bcIndex + 1);
            break;
        }
    }
    /*
		 * Modify operand of invokestatic/invokespecial to cpIndex recorded
		 * above
		 */
    ci = methodInfo.getCodeAttribute().iterator();
    while (ci.hasNext()) {
        int bcIndex = ci.next();
        int bc = ci.byteAt(bcIndex);
        if ((bc == Opcode.INVOKESPECIAL) || (bc == Opcode.INVOKESTATIC)) {
            /*
				 * found invokespecial or invokestatic bytecode; update the
				 * operand constant pool index
				 */
            ci.write16bit(cpIndex, bcIndex + 1);
        }
    }
    ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
    DataOutputStream dataStream = new DataOutputStream(byteStream);
    classFile.write(dataStream);
    return byteStream.toByteArray();
}

Example 28 with MethodInfo

use of javassist.bytecode.MethodInfo in project duangframework by tcrct.

the class AutoBuildServiceInterface method getLocalVariableAttributeName.

/**
 * 反射取出方法里的参数名
 * @param cc                类对象
 * @param method        方法名
 * @return      方法名集合
 * @throws Exception
 */
private static List<String> getLocalVariableAttributeName(CtClass cc, Method method) throws Exception {
    List<String> paramNames = null;
    try {
        CtMethod cm = cc.getDeclaredMethod(method.getName());
        MethodInfo methodInfo = cm.getMethodInfo();
        CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
        LocalVariableAttribute attr = (LocalVariableAttribute) codeAttribute.getAttribute(LocalVariableAttribute.tag);
        if (attr != null) {
            int size = cm.getParameterTypes().length;
            paramNames = new ArrayList<>(size);
            int pos = Modifier.isStatic(cm.getModifiers()) ? 0 : 1;
            for (int i = 0; i < size; i++) {
                paramNames.add(attr.variableName(i + pos));
            }
        }
    } catch (NotFoundException e) {
        throw new RpcException(e.getMessage(), e);
    }
    return paramNames;
}

Example 29 with MethodInfo

use of javassist.bytecode.MethodInfo in project fakereplace by fakereplace.

the class Transformer method addConstructorForInstrumentation.

private void addConstructorForInstrumentation(ClassFile file) {
    MethodInfo ret = new MethodInfo(file.getConstPool(), "<init>", Constants.ADDED_CONSTRUCTOR_DESCRIPTOR);
    Bytecode code = new Bytecode(file.getConstPool());
    // if the class does not have a constructor return
    if (!ManipulationUtils.addBogusConstructorCall(file, code)) {
        return;
    }
    CodeAttribute ca = code.toCodeAttribute();
    ca.setMaxLocals(4);
    ret.setCodeAttribute(ca);
    ret.setAccessFlags(AccessFlag.PUBLIC | AccessFlag.SYNTHETIC);
    try {
        ca.computeMaxStack();
        file.addMethod(ret);
    } catch (DuplicateMemberException e) {
    } catch (Exception e) {
        throw new RuntimeException(e);
    }
}

Example 30 with MethodInfo

use of javassist.bytecode.MethodInfo in project fakereplace by fakereplace.

the class Transformer method addAbstractMethodForInstrumentation.

/**
 * Adds a method to a class that re can redefine when the class is reloaded
 */
private void addAbstractMethodForInstrumentation(ClassFile file) {
    try {
        MethodInfo m = new MethodInfo(file.getConstPool(), Constants.ADDED_METHOD_NAME, Constants.ADDED_METHOD_DESCRIPTOR);
        m.setAccessFlags(AccessFlag.PUBLIC | AccessFlag.ABSTRACT | AccessFlag.SYNTHETIC);
        file.addMethod(m);
    } catch (DuplicateMemberException e) {
    // e.printStackTrace();
    }
}