def new_jclass(self, class_file):
Heap.new_jclass(self)
self.access_flag = common_utils.get_int_from_bytes(
class_file.access_flag)
self.constant_pool = ConstantPool.new_constant_pool(class_file)
self.fields = Field.new_fields(class_file.fields,
self.constant_pool.constants)
self.methods = Method.new_methods(self, class_file.methods,
self.constant_pool.constants)
super_class = self.constant_pool.constants[
common_utils.get_int_from_bytes(class_file.super_class)]
if super_class is not None:
self.super_class_name = super_class.class_name # 从方法区取
self.interfaces = None
self.static_fields = {}
for sf in self.__get_static_fields():
desc = sf.descriptor
slot = Slot()
if desc == 'B' or desc == 'I' or desc == 'J' or desc == 'S' or desc == 'Z':
slot.num = 0
elif desc == 'C':
slot.num = '0'
elif desc == 'F':
slot.num = 0.0
elif desc == 'D':
slot.num = 0.0
self.static_fields[sf.name] = slot
def new_methods(jclass, cf_methods, constant_pool):
methods = []
for m in cf_methods:
nm = Method()
nm.jclass = jclass
nm.access_flag = common_utils.get_int_from_bytes(m.access_flags)
nm.name = constant_pool[common_utils.get_int_from_bytes(
m.name_index)]
nm.descriptor = constant_pool[common_utils.get_int_from_bytes(
m.descriptor_index)]
attr = get_attribute(m.attributes, constant_pool, 'Code')
nm.max_stack = common_utils.get_int_from_bytes(attr.max_stack)
nm.max_locals = common_utils.get_int_from_bytes(attr.max_locals)
nm.code = attr.code
nm.exceptions = []
for ex in attr.exception_table:
jex = JException()
jex.start_pc = common_utils.get_int_from_bytes(ex.start_pc)
jex.end_pc = common_utils.get_int_from_bytes(ex.end_pc)
jex.handler_pc = common_utils.get_int_from_bytes(ex.handler_pc)
jex.catch_type = common_utils.get_int_from_bytes(ex.catch_type)
nm.exceptions.append(jex)
nm.arg_desc = Method.get_arg_desc(nm.descriptor)
methods.append(nm)
return methods
def read_fields(self):
tmp_class_file = self.class_file
fields = []
for i in range(
common_utils.get_int_from_bytes(tmp_class_file.fields_count)):
field = FieldInfo()
field.access_flags = self.reader.read_b2()
field.name_index = self.reader.read_b2()
field.descriptor_index = self.reader.read_b2()
field.attributes_count = self.reader.read_b2()
field.attributes = self.read_attributes_(
common_utils.get_int_from_bytes(field.attributes_count))
fields.append(field)
tmp_class_file.fields = fields
def read_methods(self):
tmp_class = self.class_file
methods = []
for i in range(
common_utils.get_int_from_bytes(
self.class_file.methods_count)):
method = MethodInfo()
method.access_flags = self.reader.read_b2()
method.name_index = self.reader.read_b2()
method.descriptor_index = self.reader.read_b2()
method.attributes_count = self.reader.read_b2()
method.attributes = self.read_attributes_(
common_utils.get_int_from_bytes(method.attributes_count))
methods.append(method)
tmp_class.methods = methods
def new_fields(cf_fields, constant_pool):
fields = []
for f in cf_fields:
nf = Field()
nf.access_flag = common_utils.get_int_from_bytes(f.access_flags)
nf.name = constant_pool[common_utils.get_int_from_bytes(
f.name_index)]
nf.descriptor_index = common_utils.get_int_from_bytes(
f.descriptor_index)
nf.descriptor = constant_pool[nf.descriptor_index]
attr = get_attribute(f.attributes, constant_pool, 'ConstantValue')
if attr is not None:
nf.constant_value_index = common_utils.get_int_from_bytes(
attr.constant_value_index)
fields.append(nf)
return fields
def new_constant_pool(class_file):
r_cp = class_file.constant_pool
constants = []
for cp in r_cp:
if isinstance(cp, ClassInfo):
constants.append(ClassRef.new_class_ref(r_cp, cp))
elif isinstance(cp, FieldRefInfo):
constants.append(FieldRef.new_field_ref(r_cp, cp))
elif isinstance(cp, MethodRefInfo):
constants.append(MethodRef.new_method_ref(r_cp, cp))
elif isinstance(cp, InterfaceMethodRefInfo):
constants.append(None)
elif isinstance(cp, StringInfo):
st = r_cp[common_utils.get_int_from_bytes(cp.string_index)]
st = common_utils.get_string_from_bytes(st.bytes)
jstring = JString()
jstring.data = st
constants.append(jstring)
elif isinstance(cp, IntegerInfo):
jint = JInteger()
jint.data = common_utils.get_int_from_bytes(cp.bytes)
constants.append(jint)
elif isinstance(cp, FloatInfo):
jfloat = JFloat()
jfloat.data = common_utils.get_float_from_bytes(cp.bytes)
constants.append(jfloat)
elif isinstance(cp, LongInfo):
jlong = JLong()
jlong.data = common_utils.get_long_from_bytes(
cp.high_bytes, cp.low_bytes)
constants.append(jlong)
elif isinstance(cp, DoubleInfo):
jdouble = JDouble()
jdouble.data = common_utils.get_double_from_bytes(
cp.high_bytes, cp.low_bytes)
constants.append(jdouble)
elif isinstance(cp, NameAndTypeInfo):
constants.append(None)
elif isinstance(cp, Utf8Info):
constants.append(common_utils.get_string_from_bytes(cp.bytes))
elif isinstance(cp, MethodHandleInfo):
constants.append(None)
else:
constants.append(None)
constants_pool = ConstantPool()
constants_pool.constants = constants
return constants_pool
def get_attribute(attributes, constant_pool, name):
for attr in attributes:
index = common_utils.get_int_from_bytes(attr.attribute_name_index)
aname = constant_pool[index]
if aname == name:
return attr
return None
def read_interfaces(self):
tmp_class_file = self.class_file
interfaces = []
for i in range(
common_utils.get_int_from_bytes(
tmp_class_file.interface_count)):
interfaces.append(self.reader.read_b2())
tmp_class_file.interfaces = interfaces
def new_method_ref(cp, method_ref_info):
mr = MethodRef()
cl = cp[common_utils.get_int_from_bytes(method_ref_info.class_index)]
mr.class_name = MemberRef.get_string(cp, cl.name_index)
mr.cp = cp
name_and_type = MemberRef.get_obj(cp,
method_ref_info.name_and_type_index)
mr.name = MemberRef.get_string(cp, name_and_type.name_index)
mr.descriptor = MemberRef.get_string(cp,
name_and_type.descriptor_index)
return mr
def new_field_ref(cp, field_ref_info):
fr = FieldRef()
cl = cp[common_utils.get_int_from_bytes(field_ref_info.class_index)]
fr.class_name = MemberRef.get_string(cp, cl.name_index)
fr.cp = cp
name_and_type = MemberRef.get_obj(cp,
field_ref_info.name_and_type_index)
fr.name = MemberRef.get_string(cp, name_and_type.name_index)
fr.descriptor = MemberRef.get_string(cp,
name_and_type.descriptor_index)
return fr
def read_attributes_(self, attributes_count):
tmp_class = self.class_file
attributes = []
for i in range(attributes_count):
attribute_name_index = self.reader.read_b2()
attribute_length = self.reader.read_b4()
attr_name = tmp_class.constant_pool[
common_utils.get_int_from_bytes(attribute_name_index)]
attr_name = common_utils.get_string_from_bytes(attr_name.bytes)
# TODO: 重构一下这个地方，有点乱看着
if attr_name == BaseAttribute.ATTR_CONSTANT_VALUE:
attr = ConstantValueAttribute()
attr.attribute_name_index = attribute_name_index
attr.attribute_length = attribute_length
attr.constant_value_index = self.reader.read_b2()
attributes.append(attr)
elif attr_name == BaseAttribute.ATTR_CODE:
attr = CodeAttribute()
attr.attribute_name_index = attribute_name_index
attr.attribute_length = attribute_length
attr.max_stack = self.reader.read_b2()
attr.max_locals = self.reader.read_b2()
attr.code_length = self.reader.read_b4()
attr.code = self.reader.read_bn(
common_utils.get_int_from_bytes(attr.code_length))
attr.exception_table_length = self.reader.read_b2()
attr.exception_table = self.read_exception_table(
common_utils.get_int_from_bytes(
attr.exception_table_length))
attr.attributes_count = self.reader.read_b2()
attr.attributes = self.read_attributes_(
common_utils.get_int_from_bytes(attr.attributes_count))
attributes.append(attr)
elif attr_name == BaseAttribute.ATTR_SOURCE_FILE:
attr = SourceFileAttribute()
attr.attribute_name_index = attribute_name_index
attr.attribute_length = attribute_length
attr.sourcefile_index = self.reader.read_b2()
attributes.append(attr)
elif attr_name == BaseAttribute.ATTR_SIGNATURE:
attr = SignatureAttribute()
attr.attribute_name_index = attribute_name_index
attr.attribute_length = attribute_length
attr.signature_index = self.reader.read_b2()
attributes.append(attr)
# TODO: 这个 Exception 和 code 里的 exception 有什么区别?
elif attr_name == BaseAttribute.ATTR_EXCEPTIONS:
# attr = ExceptionsAttribute()
# attr.attribute_name_index = attribute_name_index
# attr.attribute_length = attribute_length
# attr.number_of_exceptions = self.reader.read_b2()
# attributes.append(attr)
self.reader.read_bn(
common_utils.get_int_from_bytes(attribute_length))
attributes.append(None)
else: # 不认识的属性跳过
self.reader.read_bn(
common_utils.get_int_from_bytes(attribute_length))
attributes.append(None)
return attributes
self.read_attributes()
def __str__(self):
tmp_class = self.class_file
return "magic: %s, minor_version: %s" % (tmp_class.magic,
tmp_class.minor_version)
if __name__ == '__main__':
parser = ClassParser('../test/Hello.class')
parser.parse()
clf = parser.class_file
print('========= magic =========')
print(parser.class_file.magic)
print('========= minor =========')
print(common_utils.get_int_from_bytes(clf.minor_version))
print('========= major =========')
print(common_utils.get_int_from_bytes(clf.major_version))
print('========= constant_pool =========')
constant_pool_count = clf.constant_pool_count
pools = clf.constant_pool
for i in range(common_utils.get_int_from_bytes(constant_pool_count) - 1):
pool = pools[i]
print(pool)
print('========= class =========')
print(common_utils.get_int_from_bytes(clf.access_flag))
print(clf.this_class)
print(clf.super_class)
print('========= interface =========')
print(clf.interface_count)
for i in range(common_utils.get_int_from_bytes(clf.interface_count)):
def get_obj(cp, index_byte):
return cp[common_utils.get_int_from_bytes(index_byte)]
def get_string(cp, index_byte):
return common_utils.get_string_from_bytes(
cp[common_utils.get_int_from_bytes(index_byte)].bytes)
def new_class_ref(cp, class_info): # ConstantPool ConstantClassInfo
cr = ClassRef()
cr.cp = cp
tmp = cp[common_utils.get_int_from_bytes(class_info.name_index)]
cr.class_name = common_utils.get_string_from_bytes(tmp.bytes)
return cr
def read_attributes(self):
self.class_file.attributes = self.read_attributes_(
common_utils.get_int_from_bytes(self.class_file.attributes_count))
def read_constant_pool(self):
constant_pool = [None] # constant_pool 第 0 个元素无用
skip = False
for i in range(
common_utils.get_int_from_bytes(
self.class_file.constant_pool_count) - 1):
if skip: # long double 占两个槽
constant_pool.append(None)
skip = False
continue
info = None
tag = self.reader.read_b1()
if tag == ConstantPoolBaseInfo.CONSTANT_CLASS:
info = ClassInfo()
info.tag = tag
info.name_index = self.reader.read_b2()
elif tag == ConstantPoolBaseInfo.CONSTANT_FIELD_REF:
info = FieldRefInfo()
info.tag = tag
info.class_index = self.reader.read_b2()
info.name_and_type_index = self.reader.read_b2()
elif tag == ConstantPoolBaseInfo.CONSTANT_METHOD_REF:
info = MethodRefInfo()
info.tag = tag
info.class_index = self.reader.read_b2()
info.name_and_type_index = self.reader.read_b2()
elif tag == ConstantPoolBaseInfo.CONSTANT_INTERFACE_METHOD_REF:
info = InterfaceMethodRefInfo()
info.tag = tag
info.class_index = self.reader.read_b2()
info.name_and_type_index = self.reader.read_b2()
elif tag == ConstantPoolBaseInfo.CONSTANT_STRING:
info = StringInfo()
info.tag = tag
info.string_index = self.reader.read_b2()
elif tag == ConstantPoolBaseInfo.CONSTANT_INTEGER:
info = IntegerInfo()
info.tag = tag
info.bytes = self.reader.read_b4()
elif tag == ConstantPoolBaseInfo.CONSTANT_FLOAT:
info = FloatInfo()
info.tag = tag
info.bytes = self.reader.read_b4()
elif tag == ConstantPoolBaseInfo.CONSTANT_LONG:
info = LongInfo()
info.tag = tag
info.high_bytes = self.reader.read_b4()
info.low_bytes = self.reader.read_b4()
skip = True
elif tag == ConstantPoolBaseInfo.CONSTANT_DOUBLE:
info = DoubleInfo()
info.tag = tag
info.high_bytes = self.reader.read_b4()
info.low_bytes = self.reader.read_b4()
skip = True
elif tag == ConstantPoolBaseInfo.CONSTANT_NAME_AND_TYPE:
info = NameAndTypeInfo()
info.tag = tag
info.name_index = self.reader.read_b2()
info.descriptor_index = self.reader.read_b2()
elif tag == ConstantPoolBaseInfo.CONSTANT_UTF_8:
info = Utf8Info()
info.tag = tag
info.length = self.reader.read_b2()
info.bytes = self.reader.read_bn(
common_utils.get_int_from_bytes(info.length))
elif tag == ConstantPoolBaseInfo.CONSTANT_METHOD_HANDLE:
info = MethodHandleInfo()
info.tag = tag
info.reference_kind = self.reader.read_b1()
info.reference_index = self.reader.read_b2()
elif tag == ConstantPoolBaseInfo.CONSTANT_METHOD_TYPE:
info = MethodTypeInfo()
info.tag = tag
info.descriptor_index = self.reader.read_b2()
elif tag == ConstantPoolBaseInfo.CONSTANT_INVOKE_DYNAMIC:
info = InvokeDynamicInfo()
info.tag = tag
info.bootstrap_method_attr_index = self.reader.read_b2()
info.name_and_type_index = self.reader.read_b2()
if info is not None:
constant_pool.append(info)
self.class_file.constant_pool = constant_pool
