"""Disassembler of Python byte code into mnemonics."""
import sys
import string
import types
def dis(x=None):
"""Disassemble classes, methods, functions, or code.
With no argument, disassemble the last traceback.
"""
if not x:
distb()
return
if type(x) is types.InstanceType:
x = x.__class__
if hasattr(x, '__dict__'):
items = x.__dict__.items()
items.sort()
for name, x1 in items:
if type(x1) in (types.MethodType,
types.FunctionType,
types.CodeType):
print "Disassembly of %s:" % name
try:
dis(x1)
except TypeError, msg:
print "Sorry:", msg
print
else:
if hasattr(x, 'im_func'):
x = x.im_func
if hasattr(x, 'func_code'):
x = x.func_code
if hasattr(x, 'co_code'):
disassemble(x)
else:
raise TypeError, \
"don't know how to disassemble %s objects" % \
type(x).__name__
def distb(tb=None):
"""Disassemble a traceback (default: last traceback)."""
if not tb:
try:
tb = sys.last_traceback
except AttributeError:
raise RuntimeError, "no last traceback to disassemble"
while tb.tb_next: tb = tb.tb_next
disassemble(tb.tb_frame.f_code, tb.tb_lasti)
def disassemble(co, lasti=-1):
"""Disassemble a code object."""
code = co.co_code
labels = findlabels(code)
n = len(code)
i = 0
while i < n:
c = code[i]
op = ord(c)
if op == SET_LINENO and i > 0: print # Extra blank line
if i == lasti: print '-->',
else: print ' ',
if i in labels: print '>>',
else: print ' ',
print string.rjust(`i`, 4),
print string.ljust(opname[op], 15),
i = i+1
if op >= HAVE_ARGUMENT:
oparg = ord(code[i]) + ord(code[i+1])*256
i = i+2
print string.rjust(`oparg`, 5),
if op in hasconst:
print '(' + `co.co_consts[oparg]` + ')',
elif op in hasname:
print '(' + co.co_names[oparg] + ')',
elif op in hasjrel:
print '(to ' + `i + oparg` + ')',
elif op in haslocal:
print '(' + co.co_varnames[oparg] + ')',
elif op in hascompare:
print '(' + cmp_op[oparg] + ')',
print
disco = disassemble # XXX For backwards compatibility
def findlabels(code):
"""Detect all offsets in a byte code which are jump targets.
Return the list of offsets.
"""
labels = []
n = len(code)
i = 0
while i < n:
c = code[i]
op = ord(c)
i = i+1
if op >= HAVE_ARGUMENT:
oparg = ord(code[i]) + ord(code[i+1])*256
i = i+2
label = -1
if op in hasjrel:
label = i+oparg
elif op in hasjabs:
label = oparg
if label >= 0:
if label not in labels:
labels.append(label)
return labels
cmp_op = ('<', '<=', '==', '!=', '>', '>=', 'in', 'not in', 'is',
'is not', 'exception match', 'BAD')
hasconst = []
hasname = []
hasjrel = []
hasjabs = []
haslocal = []
hascompare = []
opname = [''] * 256
for op in range(256): opname[op] = '<' + `op` + '>'
def def_op(name, op):
opname[op] = name
def name_op(name, op):
opname[op] = name
hasname.append(op)
def jrel_op(name, op):
opname[op] = name
hasjrel.append(op)
def jabs_op(name, op):
opname[op] = name
hasjabs.append(op)
# Instruction opcodes for compiled code
def_op('STOP_CODE', 0)
def_op('POP_TOP', 1)
def_op('ROT_TWO', 2)
def_op('ROT_THREE', 3)
def_op('DUP_TOP', 4)
def_op('UNARY_POSITIVE', 10)
def_op('UNARY_NEGATIVE', 11)
def_op('UNARY_NOT', 12)
def_op('UNARY_CONVERT', 13)
def_op('UNARY_INVERT', 15)
def_op('BINARY_POWER', 19)
def_op('BINARY_MULTIPLY', 20)
def_op('BINARY_DIVIDE', 21)
def_op('BINARY_MODULO', 22)
def_op('BINARY_ADD', 23)
def_op('BINARY_SUBTRACT', 24)
def_op('BINARY_SUBSCR', 25)
def_op('SLICE+0', 30)
def_op('SLICE+1', 31)
def_op('SLICE+2', 32)
def_op('SLICE+3', 33)
def_op('STORE_SLICE+0', 40)
def_op('STORE_SLICE+1', 41)
def_op('STORE_SLICE+2', 42)
def_op('STORE_SLICE+3', 43)
def_op('DELETE_SLICE+0', 50)
def_op('DELETE_SLICE+1', 51)
def_op('DELETE_SLICE+2', 52)
def_op('DELETE_SLICE+3', 53)
def_op('STORE_SUBSCR', 60)
def_op('DELETE_SUBSCR', 61)
def_op('BINARY_LSHIFT', 62)
def_op('BINARY_RSHIFT', 63)
def_op('BINARY_AND', 64)
def_op('BINARY_XOR', 65)
def_op('BINARY_OR', 66)
def_op('PRINT_EXPR', 70)
def_op('PRINT_ITEM', 71)
def_op('PRINT_NEWLINE', 72)
def_op('BREAK_LOOP', 80)
def_op('LOAD_LOCALS', 82)
def_op('RETURN_VALUE', 83)
def_op('EXEC_STMT', 85)
def_op('POP_BLOCK', 87)
def_op('END_FINALLY', 88)
def_op('BUILD_CLASS', 89)
HAVE_ARGUMENT = 90 # Opcodes from here have an argument:
name_op('STORE_NAME', 90) # Index in name list
name_op('DELETE_NAME', 91) # ""
def_op('UNPACK_TUPLE', 92) # Number of tuple items
def_op('UNPACK_LIST', 93) # Number of list items
name_op('STORE_ATTR', 95) # Index in name list
name_op('DELETE_ATTR', 96) # ""
name_op('STORE_GLOBAL', 97) # ""
name_op('DELETE_GLOBAL', 98) # ""
def_op('LOAD_CONST', 100) # Index in const list
hasconst.append(100)
name_op('LOAD_NAME', 101) # Index in name list
def_op('BUILD_TUPLE', 102) # Number of tuple items
def_op('BUILD_LIST', 103) # Number of list items
def_op('BUILD_MAP', 104) # Always zero for now
name_op('LOAD_ATTR', 105) # Index in name list
def_op('COMPARE_OP', 106) # Comparison operator
hascompare.append(106)
name_op('IMPORT_NAME', 107) # Index in name list
name_op('IMPORT_FROM', 108) # Index in name list
jrel_op('JUMP_FORWARD', 110) # Number of bytes to skip
jrel_op('JUMP_IF_FALSE', 111) # ""
jrel_op('JUMP_IF_TRUE', 112) # ""
jabs_op('JUMP_ABSOLUTE', 113) # Target byte offset from beginning of code
jrel_op('FOR_LOOP', 114) # Number of bytes to skip
name_op('LOAD_GLOBAL', 116) # Index in name list
jrel_op('SETUP_LOOP', 120) # Distance to target address
jrel_op('SETUP_EXCEPT', 121) # ""
jrel_op('SETUP_FINALLY', 122) # ""
def_op('LOAD_FAST', 124) # Local variable number
haslocal.append(124)
def_op('STORE_FAST', 125) # Local variable number
haslocal.append(125)
def_op('DELETE_FAST', 126) # Local variable number
haslocal.append(126)
def_op('SET_LINENO', 127) # Current line number
SET_LINENO = 127
def_op('RAISE_VARARGS', 130)
def_op('CALL_FUNCTION', 131)
def_op('MAKE_FUNCTION', 132)
def_op('BUILD_SLICE', 133)
def _test():
"""Simple test program to disassemble a file."""
if sys.argv[1:]:
if sys.argv[2:]:
sys.stderr.write("usage: python dis.py [-|file]\n")
sys.exit(2)
fn = sys.argv[1]
if not fn or fn == "-":
fn = None
else:
fn = None
if not fn:
f = sys.stdin
else:
f = open(fn)
source = f.read()
if fn:
f.close()
else:
fn = "<stdin>"
code = compile(source, fn, "exec")
dis(code)
if __name__ == "__main__":
_test()
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