def calc_static_field_slot_ids(clazz: Class):
slot_id = 0
for field in clazz.fields:
if field.is_static():
field.slot_id = slot_id
slot_id += 1
clazz.static_slot_count = slot_id
def parse_class(data):
from classfile.ClassFile import ClassFile
class_file = ClassFile()
cf, err = class_file.parse(data)
if err:
raise RuntimeError("java.lang.ClassFormatError!")
else:
return Class.new_class(cf)
def load_array_class(self, name):
clazz = Class()
clazz.access_flags = AccessFlags.ACC_PUBLIC
clazz.name = name
clazz.loader = self
# 数组类不需要初始化，把init_started字段设置成True
clazz.init_started = True
# 数组类的超类是java.lang.Object
clazz.super_class = self.load_class("java/lang/Object")
# 并实现了java.lang.Cloneable和java.io.Serializable接口
clazz.interfaces = [self.load_class("java/lang/Cloneable"), self.load_class("java/io/Serializable")]
self.class_map[name] = clazz
return clazz
def calc_instantce_field_slot_ids(clazz: Class):
slot_id = 0
if clazz.super_class is not None:
slot_id = clazz.super_class.instance_slot_count
for field in clazz.fields:
if not field.is_static():
field.slot_id = slot_id
slot_id += 1
# 不需要判断long和double，每一个slot可设置为一个对象
clazz.instance_slot_count = slot_id
def load_primitive_class(self, class_name):
"""
有3点说明：1. void和基本类型的类名就是void、int、float等。
2. 基本类型的类没有超类，也没有实现任何接口。
3. 非基本类型的类对象是通过ldc指令加载到操作数栈中的。
而基本类型的类对象，虽然在Java代码中看起来是通过字面量获取的，但是编译之后的指令并不是ldc，而是getstatic。
:param class_name:
:return:
"""
clazz = Class()
clazz.access_flags = AccessFlags.ACC_PUBLIC
clazz.name = class_name
clazz.loader = self
clazz.init_started = True
clazz.j_class = self.class_map.get('java/lang/Class').new_object()
clazz.j_class.extra = clazz
self.class_map[class_name] = clazz
def resolve_super_class(clazz: Class):
if clazz.name != "java/lang/object" and clazz.super_class_name:
clazz.super_class = clazz.loader.load_class(clazz.super_class_name)
def alloc_and_init_static_vars(clazz: Class):
clazz.static_vars = Slots(clazz.static_slot_count)
for field in clazz.fields:
if field.is_static() and field.is_final():
ClassLoader.init_static_final_var(clazz, field)
def is_instance_of(self, clazz: Class) -> bool:
return clazz.is_assignable_from(self._class)
def init_super_class(thread: Thread, clazz: Class):
if not clazz.is_interface():
super_class = clazz.super_class
if super_class is not None and not super_class.init_started:
init_class(thread, super_class)
def schedule_clinit(thread: Thread, clazz: Class):
clinit = clazz.get_clinit_method()
if clinit is not None:
new_frame = thread.new_frame(clinit)
thread.push_frame(new_frame)
def init_class(thread: Thread, clazz: Class):
# 把类的init_started状态设置成true
clazz.start_init()
schedule_clinit(thread, clazz)
init_super_class(thread, clazz)
