"""
Python compiled source code parser.
Informations:
- Python 2.4.2 source code:
files Python/marshal.c and Python/import.c
Author: Victor Stinner
Creation: 25 march 2005
"""
DISASSEMBLE = False
from hachoir_parser import Parser
from hachoir_core.field import (FieldSet,
UInt16, Int32, UInt32, Int64, ParserError, Float64, Enum,
Character, Bytes, RawBytes, PascalString8, TimestampUnix32)
from hachoir_core.endian import LITTLE_ENDIAN
from hachoir_core.bits import long2raw
from hachoir_core.text_handler import textHandler, hexadecimal
from hachoir_core.i18n import ngettext
if DISASSEMBLE:
from dis import dis
def disassembleBytecode(field):
bytecode = field.value
dis(bytecode)
# --- String and string reference ---
def parseString(parent):
yield UInt32(parent, "length", "Length")
length = parent["length"].value
if 0 < length:
yield RawBytes(parent, "text", length, "Content")
if DISASSEMBLE and parent.name == "compiled_code":
disassembleBytecode(parent["text"])
def parseStringRef(parent):
yield textHandler(UInt32(parent, "ref"), hexadecimal)
def createStringRefDesc(parent):
return "String ref: %s" % parent["ref"].display
# --- Integers ---
def parseInt32(parent):
yield Int32(parent, "value")
def parseInt64(parent):
yield Int64(parent, "value")
def parseLong(parent):
yield Int32(parent, "digit_count")
for index in xrange( abs(parent["digit_count"].value) ):
yield UInt16(parent, "digit[]")
# --- Float and complex ---
def parseFloat(parent):
yield PascalString8(parent, "value")
def parseBinaryFloat(parent):
yield Float64(parent, "value")
def parseComplex(parent):
yield PascalString8(parent, "real")
yield PascalString8(parent, "complex")
def parseBinaryComplex(parent):
yield Float64(parent, "real")
yield Float64(parent, "complex")
# --- Tuple and list ---
def parseTuple(parent):
yield Int32(parent, "count", "Item count")
count = parent["count"].value
if count < 0:
raise ParserError("Invalid tuple/list count")
for index in xrange(count):
yield Object(parent, "item[]")
def createTupleDesc(parent):
count = parent["count"].value
items = ngettext("%s item", "%s items", count) % count
return "%s: %s" % (parent.code_info[2], items)
# --- Dict ---
def parseDict(parent):
"""
Format is: (key1, value1, key2, value2, ..., keyn, valuen, NULL)
where each keyi and valuei is an object.
"""
parent.count = 0
while True:
key = Object(parent, "key[]")
yield key
if key["bytecode"].value == "0":
break
yield Object(parent, "value[]")
parent.count += 1
def createDictDesc(parent):
return "Dict: %s" % (ngettext("%s key", "%s keys", parent.count) % parent.count)
# --- Code ---
def parseCode(parent):
if 0x2030000 <= parent.root.getVersion():
yield UInt32(parent, "arg_count", "Argument count")
yield UInt32(parent, "nb_locals", "Number of local variables")
yield UInt32(parent, "stack_size", "Stack size")
yield UInt32(parent, "flags")
else:
yield UInt16(parent, "arg_count", "Argument count")
yield UInt16(parent, "nb_locals", "Number of local variables")
yield UInt16(parent, "stack_size", "Stack size")
yield UInt16(parent, "flags")
yield Object(parent, "compiled_code")
yield Object(parent, "consts")
yield Object(parent, "names")
yield Object(parent, "varnames")
if 0x2000000 <= parent.root.getVersion():
yield Object(parent, "freevars")
yield Object(parent, "cellvars")
yield Object(parent, "filename")
yield Object(parent, "name")
if 0x2030000 <= parent.root.getVersion():
yield UInt32(parent, "firstlineno", "First line number")
else:
yield UInt16(parent, "firstlineno", "First line number")
yield Object(parent, "lnotab")
class Object(FieldSet):
bytecode_info = {
# Don't contains any data
'0': ("null", None, "NULL", None),
'N': ("none", None, "None", None),
'F': ("false", None, "False", None),
'T': ("true", None, "True", None),
'S': ("stop_iter", None, "StopIter", None),
'.': ("ellipsis", None, "ELLIPSIS", None),
'?': ("unknown", None, "Unknown", None),
'i': ("int32", parseInt32, "Int32", None),
'I': ("int64", parseInt64, "Int64", None),
'f': ("float", parseFloat, "Float", None),
'g': ("bin_float", parseBinaryFloat, "Binary float", None),
'x': ("complex", parseComplex, "Complex", None),
'y': ("bin_complex", parseBinaryComplex, "Binary complex", None),
'l': ("long", parseLong, "Long", None),
's': ("string", parseString, "String", None),
't': ("interned", parseString, "Interned", None),
'u': ("unicode", parseString, "Unicode", None),
'R': ("string_ref", parseStringRef, "String ref", createStringRefDesc),
'(': ("tuple", parseTuple, "Tuple", createTupleDesc),
'[': ("list", parseTuple, "List", createTupleDesc),
'<': ("set", parseTuple, "Set", createTupleDesc),
'>': ("frozenset", parseTuple, "Frozen set", createTupleDesc),
'{': ("dict", parseDict, "Dict", createDictDesc),
'c': ("code", parseCode, "Code", None),
}
def __init__(self, parent, name, **kw):
FieldSet.__init__(self, parent, name, **kw)
code = self["bytecode"].value
if code not in self.bytecode_info:
raise ParserError('Unknown bytecode: "%s"' % code)
self.code_info = self.bytecode_info[code]
if not name:
self._name = self.code_info[0]
if code == "l":
self.createValue = self.createValueLong
elif code in ("i", "I", "f", "g"):
self.createValue = lambda: self["value"].value
elif code == "T":
self.createValue = lambda: True
elif code == "F":
self.createValue = lambda: False
elif code in ("x", "y"):
self.createValue = self.createValueComplex
elif code in ("s", "t", "u"):
self.createValue = self.createValueString
self.createDisplay = self.createDisplayString
def createValueString(self):
if "text" in self:
return self["text"].value
else:
return ""
def createDisplayString(self):
if "text" in self:
return self["text"].display
else:
return "(empty)"
def createValueLong(self):
is_negative = self["digit_count"].value < 0
count = abs(self["digit_count"].value)
total = 0
for index in xrange(count-1, -1, -1):
total <<= 15
total += self["digit[%u]" % index].value
if is_negative:
total = -total
return total
def createValueComplex(self):
return complex(
float(self["real"].value),
float(self["complex"].value))
def createFields(self):
yield Character(self, "bytecode", "Bytecode")
parser = self.code_info[1]
if parser:
for field in parser(self):
yield field
def createDescription(self):
create = self.code_info[3]
if create:
return create(self)
else:
return self.code_info[2]
class PythonCompiledFile(Parser):
PARSER_TAGS = {
"id": "python",
"category": "program",
"file_ext": ("pyc", "pyo"),
"min_size": 9*8,
"description": "Compiled Python script (.pyc/.pyo files)"
}
endian = LITTLE_ENDIAN
# Dictionnary which associate the pyc signature (32-bit integer)
# to a Python version string (eg. "m\xf2\r\n" => "Python 2.4b1").
# This list comes from CPython source code, see "MAGIC"
# and "pyc_magic" in file Python/import.c
MAGIC = {
20121: ("1.5", 0x1050000),
50823: ("2.0", 0x2000000),
60202: ("2.1", 0x2010000),
60717: ("2.2", 0x2020000),
62011: ("2.3a0", 0x2030000),
62021: ("2.3a0", 0x2030000),
62041: ("2.4a0", 0x2040000),
62051: ("2.4a3", 0x2040000),
62061: ("2.4b1", 0x2040000),
62071: ("2.5a0", 0x2050000),
62081: ("2.5a0 (ast-branch)", 0x2050000),
62091: ("2.5a0 (with)", 0x2050000),
62092: ("2.5a0 (WITH_CLEANUP opcode)", 0x2050000),
62101: ("2.5b3", 0x2050000),
62111: ("2.5b3", 0x2050000),
62121: ("2.5c1", 0x2050000),
62131: ("2.5c2", 0x2050000),
}
# Dictionnary which associate the pyc signature (4-byte long string)
# to a Python version string (eg. "m\xf2\r\n" => "2.4b1")
STR_MAGIC = dict( \
(long2raw(magic | (ord('\r')<<16) | (ord('\n')<<24), LITTLE_ENDIAN), value[0]) \
for magic, value in MAGIC.iteritems())
def validate(self):
signature = self.stream.readBits(0, 16, self.endian)
if signature not in self.MAGIC:
return "Unknown version"
if self.stream.readBytes(2*8, 2) != "\r\n":
return r"Wrong signature (\r\n)"
if self.stream.readBytes(8*8, 1) != 'c':
return "First object bytecode is not code"
return True
def getVersion(self):
if not hasattr(self, "version"):
signature = self.stream.readBits(0, 16, self.endian)
self.version = self.MAGIC[signature][1]
return self.version
def createFields(self):
yield Enum(Bytes(self, "signature", 4, "Python file signature and version"), self.STR_MAGIC)
yield TimestampUnix32(self, "timestamp", "Timestamp")
yield Object(self, "content")
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