"""Disassembler of Python byte code into mnemonics."""

import sys

import types

import collections

import io

from opcode import *

from opcode import (

__all__ as _opcodes_all,

_cache_format,

_inline_cache_entries,

_nb_ops,

_common_constants,

_intrinsic_1_descs,

_intrinsic_2_descs,

_special_method_names,

_specializations,

_specialized_opmap,

)

from _opcode import get_executor

__all__ = ["code_info", "dis", "disassemble", "distb", "disco",

"findlinestarts", "findlabels", "show_code",

"get_instructions", "Instruction", "Bytecode"] + _opcodes_all

del _opcodes_all

_have_code = (types.MethodType, types.FunctionType, types.CodeType,

classmethod, staticmethod, type)

CONVERT_VALUE = opmap['CONVERT_VALUE']

SET_FUNCTION_ATTRIBUTE = opmap['SET_FUNCTION_ATTRIBUTE']

FUNCTION_ATTR_FLAGS = ('defaults', 'kwdefaults', 'annotations', 'closure', 'annotate')

ENTER_EXECUTOR = opmap['ENTER_EXECUTOR']

LOAD_GLOBAL = opmap['LOAD_GLOBAL']

LOAD_SMALL_INT = opmap['LOAD_SMALL_INT']

BINARY_OP = opmap['BINARY_OP']

JUMP_BACKWARD = opmap['JUMP_BACKWARD']

FOR_ITER = opmap['FOR_ITER']

SEND = opmap['SEND']

LOAD_ATTR = opmap['LOAD_ATTR']

LOAD_SUPER_ATTR = opmap['LOAD_SUPER_ATTR']

CALL_INTRINSIC_1 = opmap['CALL_INTRINSIC_1']

CALL_INTRINSIC_2 = opmap['CALL_INTRINSIC_2']

LOAD_COMMON_CONSTANT = opmap['LOAD_COMMON_CONSTANT']

LOAD_SPECIAL = opmap['LOAD_SPECIAL']

LOAD_FAST_LOAD_FAST = opmap['LOAD_FAST_LOAD_FAST']

STORE_FAST_LOAD_FAST = opmap['STORE_FAST_LOAD_FAST']

STORE_FAST_STORE_FAST = opmap['STORE_FAST_STORE_FAST']

IS_OP = opmap['IS_OP']

CONTAINS_OP = opmap['CONTAINS_OP']

CACHE = opmap["CACHE"]

_all_opname = list(opname)

_all_opmap = dict(opmap)

for name, op in _specialized_opmap.items():

# fill opname and opmap

assert op < len(_all_opname)

_all_opname[op] = name

_all_opmap[name] = op

deoptmap = {

specialized: base for base, family in _specializations.items() for specialized in family

}

def _try_compile(source, name):

"""Attempts to compile the given source, first as an expression and

then as a statement if the first approach fails.

Utility function to accept strings in functions that otherwise

expect code objects

"""

try:

return compile(source, name, 'eval')

except SyntaxError:

pass

return compile(source, name, 'exec')

def dis(x=None, *, file=None, depth=None, show_caches=False, adaptive=False,

show_offsets=False, show_positions=False):

"""Disassemble classes, methods, functions, and other compiled objects.

With no argument, disassemble the last traceback.

Compiled objects currently include generator objects, async generator

objects, and coroutine objects, all of which store their code object

in a special attribute.

"""

if x is None:

distb(file=file, show_caches=show_caches, adaptive=adaptive,

show_offsets=show_offsets, show_positions=show_positions)

return

# Extract functions from methods.

if hasattr(x, '__func__'):

x = x.__func__

# Extract compiled code objects from...

if hasattr(x, '__code__'): # ...a function, or

x = x.__code__

elif hasattr(x, 'gi_code'): #...a generator object, or

x = x.gi_code

elif hasattr(x, 'ag_code'): #...an asynchronous generator object, or

x = x.ag_code

elif hasattr(x, 'cr_code'): #...a coroutine.

x = x.cr_code

# Perform the disassembly.

if hasattr(x, '__dict__'): # Class or module

items = sorted(x.__dict__.items())

for name, x1 in items:

if isinstance(x1, _have_code):

print("Disassembly of %s:" % name, file=file)

try:

dis(x1, file=file, depth=depth, show_caches=show_caches, adaptive=adaptive, show_offsets=show_offsets, show_positions=show_positions)

except TypeError as msg:

print("Sorry:", msg, file=file)

print(file=file)

elif hasattr(x, 'co_code'): # Code object

_disassemble_recursive(x, file=file, depth=depth, show_caches=show_caches, adaptive=adaptive, show_offsets=show_offsets, show_positions=show_positions)

elif isinstance(x, (bytes, bytearray)): # Raw bytecode

labels_map = _make_labels_map(x)

label_width = 4 + len(str(len(labels_map)))

formatter = Formatter(file=file,

offset_width=len(str(max(len(x) - 2, 9999))) if show_offsets else 0,

label_width=label_width,

show_caches=show_caches)

arg_resolver = ArgResolver(labels_map=labels_map)

_disassemble_bytes(x, arg_resolver=arg_resolver, formatter=formatter)

elif isinstance(x, str): # Source code

_disassemble_str(x, file=file, depth=depth, show_caches=show_caches, adaptive=adaptive, show_offsets=show_offsets, show_positions=show_positions)

else:

raise TypeError("don't know how to disassemble %s objects" %

type(x).__name__)

def distb(tb=None, *, file=None, show_caches=False, adaptive=False, show_offsets=False, show_positions=False):

"""Disassemble a traceback (default: last traceback)."""

if tb is None:

try:

if hasattr(sys, 'last_exc'):

tb = sys.last_exc.__traceback__

else:

tb = sys.last_traceback

except AttributeError:

raise RuntimeError("no last traceback to disassemble") from None

while tb.tb_next: tb = tb.tb_next

disassemble(tb.tb_frame.f_code, tb.tb_lasti, file=file, show_caches=show_caches, adaptive=adaptive, show_offsets=show_offsets, show_positions=show_positions)

# The inspect module interrogates this dictionary to build its

# list of CO_* constants. It is also used by pretty_flags to

# turn the co_flags field into a human readable list.

COMPILER_FLAG_NAMES = {

1: "OPTIMIZED",

2: "NEWLOCALS",

4: "VARARGS",

8: "VARKEYWORDS",

16: "NESTED",

32: "GENERATOR",

64: "NOFREE",

128: "COROUTINE",

256: "ITERABLE_COROUTINE",

512: "ASYNC_GENERATOR",

0x4000000: "HAS_DOCSTRING",

}

def pretty_flags(flags):

"""Return pretty representation of code flags."""

names = []

for i in range(32):

flag = 1<<i

if flags & flag:

names.append(COMPILER_FLAG_NAMES.get(flag, hex(flag)))

flags ^= flag

if not flags:

break

else:

names.append(hex(flags))

return ", ".join(names)

class _Unknown:

def __repr__(self):

return "<unknown>"

# Sentinel to represent values that cannot be calculated

UNKNOWN = _Unknown()

def _get_code_object(x):

"""Helper to handle methods, compiled or raw code objects, and strings."""

# Extract functions from methods.

if hasattr(x, '__func__'):

x = x.__func__

# Extract compiled code objects from...

if hasattr(x, '__code__'): # ...a function, or

x = x.__code__

elif hasattr(x, 'gi_code'): #...a generator object, or

x = x.gi_code

elif hasattr(x, 'ag_code'): #...an asynchronous generator object, or

x = x.ag_code

elif hasattr(x, 'cr_code'): #...a coroutine.

x = x.cr_code

# Handle source code.

if isinstance(x, str):

x = _try_compile(x, "<disassembly>")

# By now, if we don't have a code object, we can't disassemble x.

if hasattr(x, 'co_code'):

return x

raise TypeError("don't know how to disassemble %s objects" %

type(x).__name__)

def _deoptop(op):

name = _all_opname[op]

return _all_opmap[deoptmap[name]] if name in deoptmap else op

def _get_code_array(co, adaptive):

if adaptive:

code = co._co_code_adaptive

res = []

found = False

for i in range(0, len(code), 2):

op, arg = code[i], code[i+1]

if op == ENTER_EXECUTOR:

try:

ex = get_executor(co, i)

except (ValueError, RuntimeError):

ex = None

if ex:

op, arg = ex.get_opcode(), ex.get_oparg()

found = True

res.append(op.to_bytes())

res.append(arg.to_bytes())

return code if not found else b''.join(res)

else:

return co.co_code

def code_info(x):

"""Formatted details of methods, functions, or code."""

return _format_code_info(_get_code_object(x))

def _format_code_info(co):

lines = []

lines.append("Name: %s" % co.co_name)

lines.append("Filename: %s" % co.co_filename)

lines.append("Argument count: %s" % co.co_argcount)

lines.append("Positional-only arguments: %s" % co.co_posonlyargcount)

lines.append("Kw-only arguments: %s" % co.co_kwonlyargcount)

lines.append("Number of locals: %s" % co.co_nlocals)

lines.append("Stack size: %s" % co.co_stacksize)

lines.append("Flags: %s" % pretty_flags(co.co_flags))

if co.co_consts:

lines.append("Constants:")

for i_c in enumerate(co.co_consts):

lines.append("%4d: %r" % i_c)

if co.co_names:

lines.append("Names:")

for i_n in enumerate(co.co_names):

lines.append("%4d: %s" % i_n)

if co.co_varnames:

lines.append("Variable names:")

for i_n in enumerate(co.co_varnames):

lines.append("%4d: %s" % i_n)

if co.co_freevars:

lines.append("Free variables:")

for i_n in enumerate(co.co_freevars):

lines.append("%4d: %s" % i_n)

if co.co_cellvars:

lines.append("Cell variables:")

for i_n in enumerate(co.co_cellvars):

lines.append("%4d: %s" % i_n)

return "\n".join(lines)

def show_code(co, *, file=None):

"""Print details of methods, functions, or code to *file*.

If *file* is not provided, the output is printed on stdout.

"""

print(code_info(co), file=file)

Positions = collections.namedtuple(

'Positions',

[

'lineno',

'end_lineno',

'col_offset',

'end_col_offset',

],

defaults=[None] * 4

)

_Instruction = collections.namedtuple(

"_Instruction",

[

'opname',

'opcode',

'arg',

'argval',

'argrepr',

'offset',

'start_offset',

'starts_line',

'line_number',

'label',

'positions',

'cache_info',

],

defaults=[None, None, None]

)

_Instruction.opname.__doc__ = "Human readable name for operation"

_Instruction.opcode.__doc__ = "Numeric code for operation"

_Instruction.arg.__doc__ = "Numeric argument to operation (if any), otherwise None"

_Instruction.argval.__doc__ = "Resolved arg value (if known), otherwise same as arg"

_Instruction.argrepr.__doc__ = "Human readable description of operation argument"

_Instruction.offset.__doc__ = "Start index of operation within bytecode sequence"

_Instruction.start_offset.__doc__ = (

"Start index of operation within bytecode sequence, including extended args if present; "

"otherwise equal to Instruction.offset"

)

_Instruction.starts_line.__doc__ = "True if this opcode starts a source line, otherwise False"

_Instruction.line_number.__doc__ = "source line number associated with this opcode (if any), otherwise None"

_Instruction.label.__doc__ = "A label (int > 0) if this instruction is a jump target, otherwise None"

_Instruction.positions.__doc__ = "dis.Positions object holding the span of source code covered by this instruction"

_Instruction.cache_info.__doc__ = "list of (name, size, data), one for each cache entry of the instruction"

_ExceptionTableEntryBase = collections.namedtuple("_ExceptionTableEntryBase",

"start end target depth lasti")

class _ExceptionTableEntry(_ExceptionTableEntryBase):

pass

_OPNAME_WIDTH = 20

_OPARG_WIDTH = 5

def _get_cache_size(opname):

return _inline_cache_entries.get(opname, 0)

def _get_jump_target(op, arg, offset):

"""Gets the bytecode offset of the jump target if this is a jump instruction.

Otherwise return None.

"""

deop = _deoptop(op)

caches = _get_cache_size(_all_opname[deop])

if deop in hasjrel:

if _is_backward_jump(deop):

arg = -arg

target = offset + 2 + arg*2

target += 2 * caches

elif deop in hasjabs:

target = arg*2

else:

target = None

return target

class Instruction(_Instruction):

"""Details for a bytecode operation.

Defined fields:

opname - human readable name for operation

opcode - numeric code for operation

arg - numeric argument to operation (if any), otherwise None

argval - resolved arg value (if known), otherwise same as arg

argrepr - human readable description of operation argument

offset - start index of operation within bytecode sequence

start_offset - start index of operation within bytecode sequence including extended args if present;

otherwise equal to Instruction.offset

starts_line - True if this opcode starts a source line, otherwise False

line_number - source line number associated with this opcode (if any), otherwise None

label - A label if this instruction is a jump target, otherwise None

positions - Optional dis.Positions object holding the span of source code

covered by this instruction

cache_info - information about the format and content of the instruction's cache

entries (if any)

"""

@property

def oparg(self):

"""Alias for Instruction.arg."""

return self.arg

@property

def baseopcode(self):

"""Numeric code for the base operation if operation is specialized.

Otherwise equal to Instruction.opcode.

"""

return _deoptop(self.opcode)

@property

def baseopname(self):

"""Human readable name for the base operation if operation is specialized.

Otherwise equal to Instruction.opname.

"""

return opname[self.baseopcode]

@property

def cache_offset(self):

"""Start index of the cache entries following the operation."""

return self.offset + 2

@property

def end_offset(self):

"""End index of the cache entries following the operation."""

return self.cache_offset + _get_cache_size(_all_opname[self.opcode])*2

@property

def jump_target(self):

"""Bytecode index of the jump target if this is a jump operation.

Otherwise return None.

"""

return _get_jump_target(self.opcode, self.arg, self.offset)

@property

def is_jump_target(self):

"""True if other code jumps to here, otherwise False"""

return self.label is not None

def __str__(self):

output = io.StringIO()

formatter = Formatter(file=output)

formatter.print_instruction(self, False)

return output.getvalue()

class Formatter:

def __init__(self, file=None, lineno_width=0, offset_width=0, label_width=0,

line_offset=0, show_caches=False, *, show_positions=False):

"""Create a Formatter

*file* where to write the output

*lineno_width* sets the width of the source location field (0 omits it).

Should be large enough for a line number or full positions (depending

on the value of *show_positions*).

*offset_width* sets the width of the instruction offset field

*label_width* sets the width of the label field

*show_caches* is a boolean indicating whether to display cache lines

*show_positions* is a boolean indicating whether full positions should

be reported instead of only the line numbers.

"""

self.file = file

self.lineno_width = lineno_width

self.offset_width = offset_width

self.label_width = label_width

self.show_caches = show_caches

self.show_positions = show_positions

def print_instruction(self, instr, mark_as_current=False):

self.print_instruction_line(instr, mark_as_current)

if self.show_caches and instr.cache_info:

offset = instr.offset

for name, size, data in instr.cache_info:

for i in range(size):

offset += 2

# Only show the fancy argrepr for a CACHE instruction when it's

# the first entry for a particular cache value:

if i == 0:

argrepr = f"{name}: {int.from_bytes(data, sys.byteorder)}"

else:

argrepr = ""

self.print_instruction_line(

Instruction("CACHE", CACHE, 0, None, argrepr, offset, offset,

False, None, None, instr.positions),

False)

def print_instruction_line(self, instr, mark_as_current):

"""Format instruction details for inclusion in disassembly output."""

lineno_width = self.lineno_width

offset_width = self.offset_width

label_width = self.label_width

new_source_line = (lineno_width > 0 and

instr.starts_line and

instr.offset > 0)

if new_source_line:

print(file=self.file)

fields = []

# Column: Source code locations information

if lineno_width:

if self.show_positions:

# reporting positions instead of just line numbers

if instr_positions := instr.positions:

if all(p is None for p in instr_positions):

positions_str = _NO_LINENO

else:

ps = tuple('?' if p is None else p for p in instr_positions)

positions_str = f"{ps[0]}:{ps[2]}-{ps[1]}:{ps[3]}"

fields.append(f'{positions_str:{lineno_width}}')

else:

fields.append(' ' * lineno_width)

else:

if instr.starts_line:

lineno_fmt = "%%%dd" if instr.line_number is not None else "%%%ds"

lineno_fmt = lineno_fmt % lineno_width

lineno = _NO_LINENO if instr.line_number is None else instr.line_number

fields.append(lineno_fmt % lineno)

else:

fields.append(' ' * lineno_width)

# Column: Label

if instr.label is not None:

lbl = f"L{instr.label}:"

fields.append(f"{lbl:>{label_width}}")

else:

fields.append(' ' * label_width)

# Column: Instruction offset from start of code sequence

if offset_width > 0:

fields.append(f"{repr(instr.offset):>{offset_width}} ")

# Column: Current instruction indicator

if mark_as_current:

fields.append('-->')

else:

fields.append(' ')

# Column: Opcode name

fields.append(instr.opname.ljust(_OPNAME_WIDTH))

# Column: Opcode argument

if instr.arg is not None:

arg = repr(instr.arg)

# If opname is longer than _OPNAME_WIDTH, we allow it to overflow into

# the space reserved for oparg. This results in fewer misaligned opargs

# in the disassembly output.

opname_excess = max(0, len(instr.opname) - _OPNAME_WIDTH)

fields.append(repr(instr.arg).rjust(_OPARG_WIDTH - opname_excess))

# Column: Opcode argument details

if instr.argrepr:

fields.append('(' + instr.argrepr + ')')

print(' '.join(fields).rstrip(), file=self.file)

def print_exception_table(self, exception_entries):

file = self.file

if exception_entries:

print("ExceptionTable:", file=file)

for entry in exception_entries:

lasti = " lasti" if entry.lasti else ""

start = entry.start_label

end = entry.end_label

target = entry.target_label

print(f" L{start} to L{end} -> L{target} [{entry.depth}]{lasti}", file=file)

class ArgResolver:

def __init__(self, co_consts=None, names=None, varname_from_oparg=None, labels_map=None):

self.co_consts = co_consts

self.names = names

self.varname_from_oparg = varname_from_oparg

self.labels_map = labels_map or {}

def offset_from_jump_arg(self, op, arg, offset):

deop = _deoptop(op)

if deop in hasjabs:

return arg * 2

elif deop in hasjrel:

signed_arg = -arg if _is_backward_jump(deop) else arg

argval = offset + 2 + signed_arg*2

caches = _get_cache_size(_all_opname[deop])

argval += 2 * caches

return argval

return None

def get_label_for_offset(self, offset):

return self.labels_map.get(offset, None)

def get_argval_argrepr(self, op, arg, offset):

get_name = None if self.names is None else self.names.__getitem__

argval = None

argrepr = ''

deop = _deoptop(op)

if arg is not None:

# Set argval to the dereferenced value of the argument when

# available, and argrepr to the string representation of argval.

# _disassemble_bytes needs the string repr of the

# raw name index for LOAD_GLOBAL, LOAD_CONST, etc.

argval = arg

if deop in hasconst:

argval, argrepr = _get_const_info(deop, arg, self.co_consts)

elif deop in hasname:

if deop == LOAD_GLOBAL:

argval, argrepr = _get_name_info(arg//2, get_name)

if (arg & 1) and argrepr:

argrepr = f"{argrepr} + NULL"

elif deop == LOAD_ATTR:

argval, argrepr = _get_name_info(arg//2, get_name)

if (arg & 1) and argrepr:

argrepr = f"{argrepr} + NULL|self"

elif deop == LOAD_SUPER_ATTR:

argval, argrepr = _get_name_info(arg//4, get_name)

if (arg & 1) and argrepr:

argrepr = f"{argrepr} + NULL|self"

else:

argval, argrepr = _get_name_info(arg, get_name)

elif deop in hasjump or deop in hasexc:

argval = self.offset_from_jump_arg(op, arg, offset)

lbl = self.get_label_for_offset(argval)

assert lbl is not None

argrepr = f"to L{lbl}"

elif deop in (LOAD_FAST_LOAD_FAST, STORE_FAST_LOAD_FAST, STORE_FAST_STORE_FAST):

arg1 = arg >> 4

arg2 = arg & 15

val1, argrepr1 = _get_name_info(arg1, self.varname_from_oparg)

val2, argrepr2 = _get_name_info(arg2, self.varname_from_oparg)

argrepr = argrepr1 + ", " + argrepr2

argval = val1, val2

elif deop in haslocal or deop in hasfree:

argval, argrepr = _get_name_info(arg, self.varname_from_oparg)

elif deop in hascompare:

argval = cmp_op[arg >> 5]

argrepr = argval

if arg & 16:

argrepr = f"bool({argrepr})"

elif deop == CONVERT_VALUE:

argval = (None, str, repr, ascii)[arg]

argrepr = ('', 'str', 'repr', 'ascii')[arg]

elif deop == SET_FUNCTION_ATTRIBUTE:

argrepr = ', '.join(s for i, s in enumerate(FUNCTION_ATTR_FLAGS)

if arg & (1<<i))

elif deop == BINARY_OP:

_, argrepr = _nb_ops[arg]

elif deop == CALL_INTRINSIC_1:

argrepr = _intrinsic_1_descs[arg]

elif deop == CALL_INTRINSIC_2:

argrepr = _intrinsic_2_descs[arg]

elif deop == LOAD_COMMON_CONSTANT:

obj = _common_constants[arg]

if isinstance(obj, type):

argrepr = obj.__name__

else:

argrepr = repr(obj)

elif deop == LOAD_SPECIAL:

argrepr = _special_method_names[arg]

elif deop == IS_OP:

argrepr = 'is not' if argval else 'is'

elif deop == CONTAINS_OP:

argrepr = 'not in' if argval else 'in'

return argval, argrepr

def get_instructions(x, *, first_line=None, show_caches=None, adaptive=False):

"""Iterator for the opcodes in methods, functions or code

Generates a series of Instruction named tuples giving the details of

each operations in the supplied code.

If *first_line* is not None, it indicates the line number that should

be reported for the first source line in the disassembled code.

Otherwise, the source line information (if any) is taken directly from

the disassembled code object.

"""

co = _get_code_object(x)

linestarts = dict(findlinestarts(co))

if first_line is not None:

line_offset = first_line - co.co_firstlineno

else:

line_offset = 0

original_code = co.co_code

arg_resolver = ArgResolver(co_consts=co.co_consts,

names=co.co_names,

varname_from_oparg=co._varname_from_oparg,

labels_map=_make_labels_map(original_code))

return _get_instructions_bytes(_get_code_array(co, adaptive),

linestarts=linestarts,

line_offset=line_offset,

co_positions=co.co_positions(),

original_code=original_code,

arg_resolver=arg_resolver)

def _get_const_value(op, arg, co_consts):

"""Helper to get the value of the const in a hasconst op.

Returns the dereferenced constant if this is possible.

Otherwise (if it is a LOAD_CONST and co_consts is not

provided) returns the dis.UNKNOWN sentinel.

"""

assert op in hasconst or op == LOAD_SMALL_INT

if op == LOAD_SMALL_INT:

return arg

argval = UNKNOWN

if co_consts is not None:

argval = co_consts[arg]

return argval

def _get_const_info(op, arg, co_consts):

"""Helper to get optional details about const references

Returns the dereferenced constant and its repr if the value

can be calculated.

Otherwise returns the sentinel value dis.UNKNOWN for the value

and an empty string for its repr.

"""

argval = _get_const_value(op, arg, co_consts)

argrepr = repr(argval) if argval is not UNKNOWN else ''

return argval, argrepr

def _get_name_info(name_index, get_name, **extrainfo):

"""Helper to get optional details about named references

Returns the dereferenced name as both value and repr if the name

list is defined.

Otherwise returns the sentinel value dis.UNKNOWN for the value

and an empty string for its repr.

"""

if get_name is not None:

argval = get_name(name_index, **extrainfo)

return argval, argval

else:

return UNKNOWN, ''

def _parse_varint(iterator):

b = next(iterator)

val = b & 63

while b&64:

val <<= 6

b = next(iterator)

val |= b&63

return val

def _parse_exception_table(code):

iterator = iter(code.co_exceptiontable)

entries = []

try:

while True:

start = _parse_varint(iterator)*2

length = _parse_varint(iterator)*2

end = start + length

target = _parse_varint(iterator)*2

dl = _parse_varint(iterator)

depth = dl >> 1

lasti = bool(dl&1)

entries.append(_ExceptionTableEntry(start, end, target, depth, lasti))

except StopIteration:

return entries

def _is_backward_jump(op):

return opname[op] in ('JUMP_BACKWARD',

'JUMP_BACKWARD_NO_INTERRUPT')

def _get_instructions_bytes(code, linestarts=None, line_offset=0, co_positions=None,

original_code=None, arg_resolver=None):

"""Iterate over the instructions in a bytecode string.

Generates a sequence of Instruction namedtuples giving the details of each

opcode.

"""

# Use the basic, unadaptive code for finding labels and actually walking the

# bytecode, since replacements like ENTER_EXECUTOR and INSTRUMENTED_* can

# mess that logic up pretty badly:

original_code = original_code or code

co_positions = co_positions or iter(())

starts_line = False

local_line_number = None

line_number = None

for offset, start_offset, op, arg in _unpack_opargs(original_code):

if linestarts is not None:

starts_line = offset in linestarts

if starts_line:

local_line_number = linestarts[offset]

if local_line_number is not None:

line_number = local_line_number + line_offset

else:

line_number = None

positions = Positions(*next(co_positions, ()))

deop = _deoptop(op)

op = code[offset]

if arg_resolver:

argval, argrepr = arg_resolver.get_argval_argrepr(op, arg, offset)

else:

argval, argrepr = arg, repr(arg)

caches = _get_cache_size(_all_opname[deop])

# Advance the co_positions iterator:

for _ in range(caches):

next(co_positions, ())

if caches:

cache_info = []

cache_offset = offset

for name, size in _cache_format[opname[deop]].items():

data = code[cache_offset + 2: cache_offset + 2 + 2 * size]

cache_offset += size * 2

cache_info.append((name, size, data))

else:

cache_info = None

label = arg_resolver.get_label_for_offset(offset) if arg_resolver else None

yield Instruction(_all_opname[op], op, arg, argval, argrepr,

offset, start_offset, starts_line, line_number,

label, positions, cache_info)

def disassemble(co, lasti=-1, *, file=None, show_caches=False, adaptive=False,

show_offsets=False, show_positions=False):

"""Disassemble a code object."""

linestarts = dict(findlinestarts(co))

exception_entries = _parse_exception_table(co)

if show_positions:

lineno_width = _get_positions_width(co)

else:

lineno_width = _get_lineno_width(linestarts)

labels_map = _make_labels_map(co.co_code, exception_entries=exception_entries)

label_width = 4 + len(str(len(labels_map)))

formatter = Formatter(file=file,

lineno_width=lineno_width,

offset_width=len(str(max(len(co.co_code) - 2, 9999))) if show_offsets else 0,

label_width=label_width,

show_caches=show_caches,

show_positions=show_positions)

arg_resolver = ArgResolver(co_consts=co.co_consts,

names=co.co_names,

varname_from_oparg=co._varname_from_oparg,

labels_map=labels_map)

_disassemble_bytes(_get_code_array(co, adaptive), lasti, linestarts,

exception_entries=exception_entries, co_positions=co.co_positions(),

original_code=co.co_code, arg_resolver=arg_resolver, formatter=formatter)

def _disassemble_recursive(co, *, file=None, depth=None, show_caches=False, adaptive=False, show_offsets=False, show_positions=False):

disassemble(co, file=file, show_caches=show_caches, adaptive=adaptive, show_offsets=show_offsets, show_positions=show_positions)

if depth is None or depth > 0:

if depth is not None:

depth = depth - 1

for x in co.co_consts:

if hasattr(x, 'co_code'):

print(file=file)

print("Disassembly of %r:" % (x,), file=file)

_disassemble_recursive(

x, file=file, depth=depth, show_caches=show_caches,

adaptive=adaptive, show_offsets=show_offsets, show_positions=show_positions

)

def _make_labels_map(original_code, exception_entries=()):

jump_targets = set(findlabels(original_code))

labels = set(jump_targets)

for start, end, target, _, _ in exception_entries:

labels.add(start)

labels.add(end)

labels.add(target)

labels = sorted(labels)

labels_map = {offset: i+1 for (i, offset) in enumerate(sorted(labels))}

for e in exception_entries:

e.start_label = labels_map[e.start]

e.end_label = labels_map[e.end]

e.target_label = labels_map[e.target]

return labels_map

_NO_LINENO = ' --'

def _get_lineno_width(linestarts):

if linestarts is None:

return 0

maxlineno = max(filter(None, linestarts.values()), default=-1)

if maxlineno == -1:

# Omit the line number column entirely if we have no line number info

return 0

lineno_width = max(3, len(str(maxlineno)))

if lineno_width < len(_NO_LINENO) and None in linestarts.values():

lineno_width = len(_NO_LINENO)

return lineno_width

def _get_positions_width(code):

# Positions are formatted as 'LINE:COL-ENDLINE:ENDCOL ' (note trailing space).

# A missing component appears as '?', and when all components are None, we

# render '_NO_LINENO'. thus the minimum width is 1 + len(_NO_LINENO).

#

# If all values are missing, positions are not printed (i.e. positions_width = 0).

has_value = False

values_width = 0

for positions in code.co_positions():

has_value |= any(isinstance(p, int) for p in positions)

width = sum(1 if p is None else len(str(p)) for p in positions)

values_width = max(width, values_width)

if has_value:

# 3 = number of separators in a normal format

return 1 + max(len(_NO_LINENO), 3 + values_width)

return 0

def _disassemble_bytes(code, lasti=-1, linestarts=None,

*, line_offset=0, exception_entries=(),

co_positions=None, original_code=None,

arg_resolver=None, formatter=None):

assert formatter is not None

assert arg_resolver is not None

instrs = _get_instructions_bytes(code, linestarts=linestarts,

line_offset=line_offset,

co_positions=co_positions,

original_code=original_code,

arg_resolver=arg_resolver)

print_instructions(instrs, exception_entries, formatter, lasti=lasti)

def print_instructions(instrs, exception_entries, formatter, lasti=-1):

for instr in instrs:

# Each CACHE takes 2 bytes

is_current_instr = instr.offset <= lasti \

<= instr.offset + 2 * _get_cache_size(_all_opname[_deoptop(instr.opcode)])

formatter.print_instruction(instr, is_current_instr)

formatter.print_exception_table(exception_entries)

def _disassemble_str(source, **kwargs):

"""Compile the source string, then disassemble the code object."""

_disassemble_recursive(_try_compile(source, '<dis>'), **kwargs)

disco = disassemble # XXX For backwards compatibility

# Rely on C `int` being 32 bits for oparg

_INT_BITS = 32

# Value for c int when it overflows

_INT_OVERFLOW = 2 ** (_INT_BITS - 1)

def _unpack_opargs(code):

extended_arg = 0

extended_args_offset = 0 # Number of EXTENDED_ARG instructions preceding the current instruction

caches = 0

for i in range(0, len(code), 2):

# Skip inline CACHE entries:

if caches:

caches -= 1

continue

op = code[i]

deop = _deoptop(op)

caches = _get_cache_size(_all_opname[deop])

if deop in hasarg:

arg = code[i+1] | extended_arg

extended_arg = (arg << 8) if deop == EXTENDED_ARG else 0

# The oparg is stored as a signed integer

# If the value exceeds its upper limit, it will overflow and wrap

# to a negative integer

if extended_arg >= _INT_OVERFLOW:

extended_arg -= 2 * _INT_OVERFLOW

else:

arg = None

extended_arg = 0

if deop == EXTENDED_ARG:

extended_args_offset += 1

yield (i, i, op, arg)

else:

start_offset = i - extended_args_offset*2

yield (i, start_offset, op, arg)

extended_args_offset = 0

def findlabels(code):

"""Detect all offsets in a byte code which are jump targets.

Return the list of offsets.

"""

labels = []

for offset, _, op, arg in _unpack_opargs(code):

if arg is not None:

label = _get_jump_target(op, arg, offset)

if label is None:

continue

if label not in labels:

labels.append(label)

return labels

def findlinestarts(code):

"""Find the offsets in a byte code which are start of lines in the source.

Generate pairs (offset, lineno)

lineno will be an integer or None the offset does not have a source line.

"""

lastline = False # None is a valid line number

for start, end, line in code.co_lines():

if line is not lastline:

lastline = line

yield start, line

return

def _find_imports(co):

"""Find import statements in the code

Generate triplets (name, level, fromlist) where

name is the imported module and level, fromlist are

the corresponding args to __import__.

"""

IMPORT_NAME = opmap['IMPORT_NAME']

consts = co.co_consts

names = co.co_names

opargs = [(op, arg) for _, _, op, arg in _unpack_opargs(co.co_code)

if op != EXTENDED_ARG]

for i, (op, oparg) in enumerate(opargs):

if op == IMPORT_NAME and i >= 2:

from_op = opargs[i-1]

level_op = opargs[i-2]

if (from_op[0] in hasconst and

(level_op[0] in hasconst or level_op[0] == LOAD_SMALL_INT)):