def __init__(self, source: IO = None):
# Default to J2SE_7
self._version = ClassVersion(0x32, 0)
self._constants = ConstantPool()
self.access_flags = Flags(
'>H', {
'acc_public': 0x0001,
'acc_final': 0x0010,
'acc_super': 0x0020,
'acc_interface': 0x0200,
'acc_abstract': 0x0400,
'acc_synthetic': 0x1000,
'acc_annotation': 0x2000,
'acc_enum': 0x4000
})
self._this = 0
self._super = 0
self._interfaces = []
self.fields = FieldTable(self)
self.methods = MethodTable(self)
self.attributes = AttributeTable(self)
#: The ClassLoader bound to this ClassFile, if any.
self.classloader = None
if source:
self._from_io(source)
def test_ldc():
value = 5.0
constants = ConstantPool()
constant = constants.create_double(value)
assert_incrementing_instruction(
instruction=constant_instruction('ldc', constant),
constants=constants,
expected=[Push(Double.create_instance(value))])
def search_constant_pool(self, *, path: str, **options):
"""Partially load the class at `path`, yield all matching constants
from the ConstantPool.
This is an optimization method that does not load a complete ClassFile,
nor does it add the results to the ClassLoader cache.
:param path: Fully-qualified path to a ClassFile.
:param options: A list of options to pass into `ConstantPool.find()`
"""
with self.open(f'{path}.class') as source:
# Skip over the magic, minor, and major version.
source.read(8)
pool = ConstantPool()
pool.unpack(source)
yield from pool.find(**options)
def __init__(self, source: IO=None):
# Default to J2SE_7
self._version = ClassVersion(0x32, 0)
self._constants = ConstantPool()
self.access_flags = Flags('>H', {
'acc_public': 0x0001,
'acc_final': 0x0010,
'acc_super': 0x0020,
'acc_interface': 0x0200,
'acc_abstract': 0x0400,
'acc_synthetic': 0x1000,
'acc_annotation': 0x2000,
'acc_enum': 0x4000
})
self._this = 0
self._super = 0
self._interfaces = []
self.fields = FieldTable(self)
self.methods = MethodTable(self)
self.attributes = AttributeTable(self)
#: The ClassLoader bound to this ClassFile, if any.
self.classloader = None
if source:
self._from_io(source)
def test_invoke_v():
method_name = 'method_name'
class_name = 'class_name'
consts = ConstantPool()
descriptor = '(II)V'
key = MethodKey(method_name, descriptor)
no_op = Instruction.create('nop')
method = BytecodeMethod(
name='method_name',
descriptor='(II)V',
max_locals=5,
max_stack=5,
instructions=[no_op, no_op],
args=[Integer, Integer],
)
jvm_class = JvmClass(
class_name,
RootObjectType.refers_to,
consts,
methods={
key: method
}
)
method_ref = consts.create_method_ref(class_name, method_name, descriptor)
instruction = constant_instruction('invokevirtual', method_ref)
loader = FixedClassLoader({
class_name: jvm_class
})
instance = loader.default_instance(class_name)
arg_value = SOME_INT
arguments = [instance, arg_value, arg_value]
reversed_arguments = list(reversed(arguments))
assert_instruction(
constants=consts,
loader=loader,
instruction=instruction,
op_stack=reversed_arguments,
expected=[
Pop(3),
Invoke(class_name, key, arguments)
]
)
def test_string_constant():
text = 'some_text'
consts = ConstantPool()
const = consts.create_string(text)
chars = [ord(c) for c in text]
char_array = ArrayReferenceType(Integer).create_instance(chars)
hash_value = hash(text) % (2**32)
hash_ = Integer.create_instance(hash_value)
reference_type = ObjectReferenceType('java/lang/String')
jvm_object = JvmObject({'hash': hash_, 'value': char_array})
assert_incrementing_instruction(
instruction=constant_instruction('ldc', const),
constants=consts,
expected=[Push(reference_type.create_instance(jvm_object))])
def complex_machine():
machine = Machine(FixedClassLoader({
COMPLEX_CLASS_NAME: COMPLEX_CLASS,
EXCEPTION_NAME: JvmClass(
name=EXCEPTION_NAME,
name_of_base=RootObjectType.refers_to,
constants=ConstantPool()
),
RootObjectType.refers_to: JvmClass(
name=RootObjectType.refers_to,
name_of_base=None,
constants=ConstantPool()
)
}))
for _ in range(2):
frame = Frame.from_class_and_method(COMPLEX_CLASS, METHOD)
machine.frames.push(frame)
return machine
def __init__(self, fio=None):
# Default to J2SE_7
self._version = ClassVersion(0x32, 0)
self._constants = ConstantPool()
self._access_flags = Flags('>H', {
'acc_public': 0x0001,
'acc_final': 0x0010,
'acc_super': 0x0020,
'acc_interface': 0x0200,
'acc_abstract': 0x0400,
'acc_synthetic': 0x1000,
'acc_annotation': 0x2000,
'acc_enum': 0x4000
})
self._this = 0
self._super = 0
self._interfaces = []
self._fields = FieldTable(self)
self._methods = MethodTable(self)
self._attributes = AttributeTable(self)
if fio:
self._from_io(fio)
def test_printable_constants():
# Ensure we can successfully repr valid constants without crashing.
pool = ConstantPool()
repr(pool.create_utf8('HelloWorld'))
repr(pool.create_class('HelloWorld'))
repr(pool.create_double(1))
repr(pool.create_float(1))
repr(pool.create_integer(1))
repr(pool.create_long(1))
repr(pool.create_name_and_type('HelloWorld', 'I'))
repr(pool.create_field_ref('HelloWorld', 'test', 'I'))
repr(pool.create_method_ref('HelloWorld', 'test', 'I)V'))
repr(pool.create_interface_method_ref(
'HelloWorld',
'test',
'I)V'
))
repr(pool.create_string('HelloWorld'))
class ClassFile(object):
"""
Implements the JVM ClassFile (files typically ending in ``.class``).
To open an existing ClassFile::
>>> with open('HelloWorld.class', 'rb') as fin:
... cf = ClassFile(fin)
To save a newly created or modified ClassFile::
>>> cf = ClassFile.create('HelloWorld')
>>> with open('HelloWorld.class', 'wb') as out:
... cf.save(out)
:meth:`~ClassFile.create` sets up some reasonable defaults equivalent to:
.. code-block:: java
public class HelloWorld extends java.lang.Object{
}
:param source: any file-like object providing ``.read()``.
"""
#: The JVM ClassFile magic number.
MAGIC = 0xCAFEBABE
def __init__(self, source: IO = None):
# Default to J2SE_7
self._version = ClassVersion(0x32, 0)
self._constants = ConstantPool()
self.access_flags = Flags(
'>H', {
'acc_public': 0x0001,
'acc_final': 0x0010,
'acc_super': 0x0020,
'acc_interface': 0x0200,
'acc_abstract': 0x0400,
'acc_synthetic': 0x1000,
'acc_annotation': 0x2000,
'acc_enum': 0x4000
})
self._this = 0
self._super = 0
self._interfaces = []
self.fields = FieldTable(self)
self.methods = MethodTable(self)
self.attributes = AttributeTable(self)
#: The ClassLoader bound to this ClassFile, if any.
self.classloader = None
if source:
self._from_io(source)
@classmethod
def create(cls,
this: str,
super_: str = u'java/lang/Object') -> 'ClassFile':
"""
A utility which sets up reasonable defaults for a new public class.
:param this: The name of this class.
:param super_: The name of this class's superclass.
"""
cf = ClassFile()
cf.access_flags.acc_public = True
cf.access_flags.acc_super = True
cf.this = cf.constants.create_class(this)
cf.super_ = cf.constants.create_class(super_)
return cf
def save(self, source: IO):
"""
Saves the class to the file-like object `source`.
:param source: Any file-like object providing write().
"""
write = source.write
write(
pack('>IHH', ClassFile.MAGIC, self.version.minor,
self.version.major))
self._constants.pack(source)
write(self.access_flags.pack())
write(
pack(f'>HHH{len(self._interfaces)}H', self._this, self._super,
len(self._interfaces), *self._interfaces))
self.fields.pack(source)
self.methods.pack(source)
self.attributes.pack(source)
def _from_io(self, source: IO):
"""
Loads an existing JVM ClassFile from any file-like object.
"""
read = source.read
if unpack('>I', source.read(4))[0] != ClassFile.MAGIC:
raise ValueError('invalid magic number')
# The version is swapped on disk to (minor, major), so swap it back.
self.version = unpack('>HH', source.read(4))[::-1]
self._constants.unpack(source)
# ClassFile access_flags, see section #4.1 of the JVM specs.
self.access_flags.unpack(read(2))
# The CONSTANT_Class indexes for "this" class and its superclass.
# Interfaces are a simple list of CONSTANT_Class indexes.
self._this, self._super, interfaces_count = unpack('>HHH', read(6))
self._interfaces = unpack(f'>{interfaces_count}H',
read(2 * interfaces_count))
self.fields.unpack(source)
self.methods.unpack(source)
self.attributes.unpack(source)
@property
def version(self) -> ClassVersion:
"""
The :class:`~jawa.cf.ClassVersion` for this class.
Example::
>>> cf = ClassFile.create('HelloWorld')
>>> cf.version = 51, 0
>>> print(cf.version)
ClassVersion(major=51, minor=0)
>>> print(cf.version.major)
51
"""
return self._version
@version.setter
def version(self, major_minor: Union[ClassVersion, Sequence]):
self._version = ClassVersion(*major_minor)
@property
def constants(self) -> ConstantPool:
"""
The :class:`~jawa.cp.ConstantPool` for this class.
"""
return self._constants
@property
def this(self) -> ConstantClass:
"""
The :class:`~jawa.constants.ConstantClass` which represents this class.
"""
return self.constants.get(self._this)
@this.setter
def this(self, value):
self._this = value.index
@property
def super_(self) -> ConstantClass:
"""
The :class:`~jawa.constants.ConstantClass` which represents this
class's superclass.
"""
return self.constants.get(self._super)
@super_.setter
def super_(self, value: ConstantClass):
self._super = value.index
@property
def interfaces(self) -> Iterable[ConstantClass]:
"""
A list of direct superinterfaces of this class as indexes into
the constant pool, in left-to-right order.
"""
return [self._constants[idx] for idx in self._interfaces]
@property
def bootstrap_methods(self) -> BootstrapMethod:
"""
Returns the bootstrap methods table from the BootstrapMethods attribute,
if one exists. If it does not, one will be created.
:returns: Table of `BootstrapMethod` objects.
"""
bootstrap = self.attributes.find_one(name='BootstrapMethods')
if bootstrap is None:
bootstrap = self.attributes.create(
ATTRIBUTE_CLASSES['BootstrapMethods'])
return bootstrap.table
def __repr__(self):
return f'<ClassFile(this={self.this.name.value!r})>'
class ClassFile(object):
"""
Implements the JVM ClassFile (files typically ending in ``.class``).
To open an existing ClassFile::
from jawa import ClassFile
with open('HelloWorld.class') as fin:
cf = ClassFile(fin)
To save a newly created or modified ClassFile::
with open('HelloWorld.class', 'wb') as fout:
cf.save(fout)
To create a new ClassFile, use the helper :meth:`~ClassFile.create`::
from jawa import ClassFile
cf = ClassFile.create('HelloWorld')
with open('HelloWorld.class', 'wb') as fout:
cf.save(fout)
:meth:`~ClassFile.create` sets up some reasonable defaults equivelent to:
.. code-block:: java
public class HelloWorld extends java.lang.Object{
}
:param fio: any file-like object providing ``.read()``.
"""
#: The JVM ClassFile magic number.
MAGIC = 0xCAFEBABE
def __init__(self, fio=None):
# Default to J2SE_7
self._version = ClassVersion(0x32, 0)
self._constants = ConstantPool()
self._access_flags = Flags('>H', {
'acc_public': 0x0001,
'acc_final': 0x0010,
'acc_super': 0x0020,
'acc_interface': 0x0200,
'acc_abstract': 0x0400,
'acc_synthetic': 0x1000,
'acc_annotation': 0x2000,
'acc_enum': 0x4000
})
self._this = 0
self._super = 0
self._interfaces = []
self._fields = FieldTable(self)
self._methods = MethodTable(self)
self._attributes = AttributeTable(self)
if fio:
self._from_io(fio)
@classmethod
def create(cls, this, super_='java/lang/Object'):
"""
A utility method which sets up reasonable defaults for a new public
class.
:param this: The name of this class.
:param super_: The name of this class's superclass.
"""
cf = ClassFile()
cf.access_flags.acc_public = True
cf.access_flags.acc_super = True
cf._this = cf.constants.create_class(this).index
cf._super = cf.constants.create_class(super_).index
return cf
def save(self, fout):
"""
Saves the class to the file-like object `fout`.
"""
write = fout.write
write(pack('>IHH',
ClassFile.MAGIC,
self.version.minor,
self.version.major
))
self._constants._to_io(fout)
write(self.access_flags.pack())
write(pack('>HHH{0}H'.format(len(self._interfaces)),
self._this,
self._super,
len(self._interfaces),
*self._interfaces
))
self._fields._to_io(fout)
self._methods._to_io(fout)
self._attributes._to_io(fout)
# ------------
# Internal
# ------------
def _from_io(self, fio):
"""
Loads an existing JVM ClassFile from any file-like object.
"""
read = fio.read
if unpack('>I', fio.read(4))[0] != ClassFile.MAGIC:
raise ValueError('invalid magic number')
# The version is swapped on disk to (minor, major), so swap it back.
self.version = unpack('>HH', fio.read(4))[::-1]
self._constants._from_io(fio)
# ClassFile access_flags, see section #4.1 of the JVM specs.
self.access_flags.unpack(read(2))
# The CONSTANT_Class indexes for "this" class and its superclass.
# Interfaces are a simple list of CONSTANT_Class indexes.
self._this, self._super, interfaces_count = unpack('>HHH', read(6))
self._interfaces = unpack(
'>{0}H'.format(interfaces_count),
read(2 * interfaces_count)
)
self._fields._from_io(fio)
self._methods._from_io(fio)
self._attributes._from_io(fio)
# -------------
# Properties
# -------------
@property
def version(self):
"""
The :class:`~jawa.cf.ClassVersion` for this class.
Example::
>>> cf.version = 51, 0
>>> print(cf.version)
ClassVersion(major=51, minor=0)
>>> print(cf.version.major)
51
"""
return self._version
@version.setter
def version(self, (major, minor)):
self._version = ClassVersion(major, minor)
METHOD = BytecodeMethod(
name='method_name',
descriptor='(II)V',
instructions=[
named_tuple_replace(Instruction.create('nop'), pos=i) for i in range(5)
],
max_locals=5,
max_stack=15,
args=[Integer, Integer],
exception_handlers=Handlers([HANDLER])
)
COMPLEX_CLASS = JvmClass(
name=COMPLEX_CLASS_NAME,
name_of_base=RootObjectType.refers_to,
constants=ConstantPool(),
fields={
FIELD_NAME: Integer
},
static_fields={
FIELD_NAME: Integer
},
methods={
METHOD_KEY: METHOD
}
)
def complex_machine():
machine = Machine(FixedClassLoader({
COMPLEX_CLASS_NAME: COMPLEX_CLASS,
def test_printable_constants():
# Ensure we can successfully repr valid constants without crashing.
pool = ConstantPool()
repr(pool.create_utf8('HelloWorld'))
repr(pool.create_class('HelloWorld'))
repr(pool.create_double(1))
repr(pool.create_float(1))
repr(pool.create_integer(1))
repr(pool.create_long(1))
repr(pool.create_name_and_type('HelloWorld', 'I'))
repr(pool.create_field_ref('HelloWorld', 'test', 'I'))
repr(pool.create_method_ref('HelloWorld', 'test', 'I)V'))
repr(pool.create_interface_method_ref('HelloWorld', 'test', 'I)V'))
repr(pool.create_string('HelloWorld'))
class ClassFile(object):
"""
Implements the JVM ClassFile (files typically ending in ``.class``).
To open an existing ClassFile::
>>> with open('HelloWorld.class', 'rb') as fin:
... cf = ClassFile(fin)
To save a newly created or modified ClassFile::
>>> cf = ClassFile.create('HelloWorld')
>>> with open('HelloWorld.class', 'wb') as out:
... cf.save(out)
:meth:`~ClassFile.create` sets up some reasonable defaults equivalent to:
.. code-block:: java
public class HelloWorld extends java.lang.Object{
}
:param source: any file-like object providing ``.read()``.
"""
#: The JVM ClassFile magic number.
MAGIC = 0xCAFEBABE
def __init__(self, source: IO=None):
# Default to J2SE_7
self._version = ClassVersion(0x32, 0)
self._constants = ConstantPool()
self.access_flags = Flags('>H', {
'acc_public': 0x0001,
'acc_final': 0x0010,
'acc_super': 0x0020,
'acc_interface': 0x0200,
'acc_abstract': 0x0400,
'acc_synthetic': 0x1000,
'acc_annotation': 0x2000,
'acc_enum': 0x4000
})
self._this = 0
self._super = 0
self._interfaces = []
self.fields = FieldTable(self)
self.methods = MethodTable(self)
self.attributes = AttributeTable(self)
#: The ClassLoader bound to this ClassFile, if any.
self.classloader = None
if source:
self._from_io(source)
@classmethod
def create(cls, this: str, super_: str=u'java/lang/Object') -> 'ClassFile':
"""
A utility which sets up reasonable defaults for a new public class.
:param this: The name of this class.
:param super_: The name of this class's superclass.
"""
cf = ClassFile()
cf.access_flags.acc_public = True
cf.access_flags.acc_super = True
cf.this = cf.constants.create_class(this)
cf.super_ = cf.constants.create_class(super_)
return cf
def save(self, source: IO):
"""
Saves the class to the file-like object `source`.
:param source: Any file-like object providing write().
"""
write = source.write
write(pack(
'>IHH',
ClassFile.MAGIC,
self.version.minor,
self.version.major
))
self._constants.pack(source)
write(self.access_flags.pack())
write(pack(
f'>HHH{len(self._interfaces)}H',
self._this,
self._super,
len(self._interfaces),
*self._interfaces
))
self.fields.pack(source)
self.methods.pack(source)
self.attributes.pack(source)
def _from_io(self, source: IO):
"""
Loads an existing JVM ClassFile from any file-like object.
"""
read = source.read
if unpack('>I', source.read(4))[0] != ClassFile.MAGIC:
raise ValueError('invalid magic number')
# The version is swapped on disk to (minor, major), so swap it back.
self.version = unpack('>HH', source.read(4))[::-1]
self._constants.unpack(source)
# ClassFile access_flags, see section #4.1 of the JVM specs.
self.access_flags.unpack(read(2))
# The CONSTANT_Class indexes for "this" class and its superclass.
# Interfaces are a simple list of CONSTANT_Class indexes.
self._this, self._super, interfaces_count = unpack('>HHH', read(6))
self._interfaces = unpack(
f'>{interfaces_count}H',
read(2 * interfaces_count)
)
self.fields.unpack(source)
self.methods.unpack(source)
self.attributes.unpack(source)
@property
def version(self) -> ClassVersion:
"""
The :class:`~jawa.cf.ClassVersion` for this class.
Example::
>>> cf = ClassFile.create('HelloWorld')
>>> cf.version = 51, 0
>>> print(cf.version)
ClassVersion(major=51, minor=0)
>>> print(cf.version.major)
51
"""
return self._version
@version.setter
def version(self, major_minor: Union[ClassVersion, Sequence]):
self._version = ClassVersion(*major_minor)
@property
def constants(self) -> ConstantPool:
"""
The :class:`~jawa.cp.ConstantPool` for this class.
"""
return self._constants
@property
def this(self) -> ConstantClass:
"""
The :class:`~jawa.constants.ConstantClass` which represents this class.
"""
return self.constants.get(self._this)
@this.setter
def this(self, value):
self._this = value.index
@property
def super_(self) -> ConstantClass:
"""
The :class:`~jawa.constants.ConstantClass` which represents this
class's superclass.
"""
return self.constants.get(self._super)
@super_.setter
def super_(self, value: ConstantClass):
self._super = value.index
@property
def interfaces(self) -> Iterable[ConstantClass]:
"""
A list of direct superinterfaces of this class as indexes into
the constant pool, in left-to-right order.
"""
return [self._constants[idx] for idx in self._interfaces]
@property
def bootstrap_methods(self) -> BootstrapMethod:
"""
Returns the bootstrap methods table from the BootstrapMethods attribute,
if one exists. If it does not, one will be created.
:returns: Table of `BootstrapMethod` objects.
"""
bootstrap = self.attributes.find_one(name='BootstrapMethods')
if bootstrap is None:
bootstrap = self.attributes.create(
ATTRIBUTE_CLASSES['BootstrapMethods']
)
return bootstrap.table
def __repr__(self):
return f'<ClassFile(this={self.this.name.value!r})>'
