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Jython is an implementation of the high-level, dynamic, object-oriented
language Python written in 100% Pure Java, and seamlessly integrated with
the Java platform. It thus allows you to run Python on any Java platform.
"""Disassembler of Python byte code into mnemonics."""
import sys
import types
from opcode import *
from opcode import __all__ as _opcodes_all
__all__ = ["dis", "disassemble", "distb", "disco",
"findlinestarts", "findlabels"] + _opcodes_all
del _opcodes_all
_have_code = (types.MethodType, types.FunctionType, types.CodeType,
types.ClassType, type)
def dis(x=None):
"""Disassemble classes, methods, functions, or code.
With no argument, disassemble the last traceback.
"""
if x is None:
distb()
return
if isinstance(x, types.InstanceType):
x = x.__class__
if hasattr(x, 'im_func'):
x = x.im_func
if hasattr(x, 'func_code'):
x = x.func_code
if hasattr(x, '__dict__'):
items = x.__dict__.items()
items.sort()
for name, x1 in items:
if isinstance(x1, _have_code):
print "Disassembly of %s:" % name
try:
dis(x1)
except TypeError, msg:
print "Sorry:", msg
print
elif hasattr(x, 'co_code'):
disassemble(x)
elif isinstance(x, str):
disassemble_string(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 tb is None:
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)
linestarts = dict(findlinestarts(co))
n = len(code)
i = 0
extended_arg = 0
free = None
while i < n:
c = code[i]
op = ord(c)
if i in linestarts:
if i > 0:
print
print "%3d" % linestarts[i],
else:
print ' ',
if i == lasti: print '-->',
else: print ' ',
if i in labels: print '>>',
else: print ' ',
print repr(i).rjust(4),
print opname[op].ljust(20),
i = i+1
if op >= HAVE_ARGUMENT:
oparg = ord(code[i]) + ord(code[i+1])*256 + extended_arg
extended_arg = 0
i = i+2
if op == EXTENDED_ARG:
extended_arg = oparg*65536L
print repr(oparg).rjust(5),
if op in hasconst:
print '(' + repr(co.co_consts[oparg]) + ')',
elif op in hasname:
print '(' + co.co_names[oparg] + ')',
elif op in hasjrel:
print '(to ' + repr(i + oparg) + ')',
elif op in haslocal:
print '(' + co.co_varnames[oparg] + ')',
elif op in hascompare:
print '(' + cmp_op[oparg] + ')',
elif op in hasfree:
if free is None:
free = co.co_cellvars + co.co_freevars
print '(' + free[oparg] + ')',
print
def disassemble_string(code, lasti=-1, varnames=None, names=None,
constants=None):
labels = findlabels(code)
n = len(code)
i = 0
while i < n:
c = code[i]
op = ord(c)
if i == lasti: print '-->',
else: print ' ',
if i in labels: print '>>',
else: print ' ',
print repr(i).rjust(4),
print opname[op].ljust(15),
i = i+1
if op >= HAVE_ARGUMENT:
oparg = ord(code[i]) + ord(code[i+1])*256
i = i+2
print repr(oparg).rjust(5),
if op in hasconst:
if constants:
print '(' + repr(constants[oparg]) + ')',
else:
print '(%d)'%oparg,
elif op in hasname:
if names is not None:
print '(' + names[oparg] + ')',
else:
print '(%d)'%oparg,
elif op in hasjrel:
print '(to ' + repr(i + oparg) + ')',
elif op in haslocal:
if varnames:
print '(' + varnames[oparg] + ')',
else:
print '(%d)' % 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
def findlinestarts(code):
"""Find the offsets in a byte code which are start of lines in the source.
Generate pairs (offset, lineno) as described in Python/compile.c.
"""
byte_increments = [ord(c) for c in code.co_lnotab[0::2]]
line_increments = [ord(c) for c in code.co_lnotab[1::2]]
lastlineno = None
lineno = code.co_firstlineno
addr = 0
for byte_incr, line_incr in zip(byte_increments, line_increments):
if byte_incr:
if lineno != lastlineno:
yield (addr, lineno)
lastlineno = lineno
addr += byte_incr
lineno += line_incr
if lineno != lastlineno:
yield (addr, lineno)
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 fn is None:
f = sys.stdin
else:
f = open(fn)
source = f.read()
if fn is not None:
f.close()
else:
fn = ""
code = compile(source, fn, "exec")
dis(code)
if __name__ == "__main__":
_test()