jinx/python-uncompyle6
1
Fork 0
mirror of https://github.com/rocky/python-uncompyle6.git synced 2025-08-03 00:45:53 +08:00
Code Issues Packages Projects Releases Wiki Activity
Files
bdd7df60407bcefd3b0d358bb6ba3c804764a30a
python-uncompyle6/uncompyle6/scanners/scanner3.py
rocky bdd7df6040 Python 2 loop scanner detection in Python 3 
scanner*.py: Make scanner27 and scanner3 more aligned
Makefile: we can run py.test on Python 3.5
HISTORY.md: grammar changes
2016-05-16 13:40:55 -04:00

916 lines
38 KiB
Python
Raw Blame History

# Copyright (c) 2015, 2016 by Rocky Bernstein
# Copyright (c) 2005 by Dan Pascu <dan@windowmaker.org>
# Copyright (c) 2000-2002 by hartmut Goebel <h.goebel@crazy-compilers.com>
# Copyright (c) 1999 John Aycock
"""
Python 3 Generic bytecode scanner/deparser
This overlaps various Python3's dis module, but it can be run from
Python versions other than the version running this code. Notably,
run from Python version 2.
Also we *modify* the instruction sequence to assist deparsing code.
For example:
- we add "COME_FROM" instructions to help in figuring out
conditional branching and looping.
- LOAD_CONSTs are classified further into the type of thing
they load:
lambda's, genexpr's, {dict,set,list} comprehension's,
- PARAMETER counts appended {CALL,MAKE}_FUNCTION, BUILD_{TUPLE,SET,SLICE}
Finally we save token information.
"""
from __future__ import print_function
import dis
import uncompyle6.scanners.dis3 as dis3
from collections import namedtuple
from array import array
from uncompyle6.code import iscode
from uncompyle6.scanner import Token
from uncompyle6 import PYTHON3
# Get all the opcodes into globals
import uncompyle6.opcodes.opcode_33 as op3
globals().update(op3.opmap)
import uncompyle6.scanner as scan
class Scanner3(scan.Scanner):
## FIXME opnames should be passed in here
def __init__(self, version):
self.version = version
self.opnames = {} # will eventually get passed in
scan.Scanner.__init__(self, version)
## FIXME opnames should be moved to init
def disassemble3(self, co, opnames, classname=None, code_objects={}):
"""
Disassemble a Python 3 ode object, returning a list of 'Token'.
Various tranformations are made to assist the deparsing grammar.
For example:
- various types of LOAD_CONST's are categorized in terms of what they load
- COME_FROM instructions are added to assist parsing control structures
- MAKE_FUNCTION and FUNCTION_CALLS append the number of positional aruments
The main part of this procedure is modelled after
dis.disassemble().
"""
self.opnames = opnames # will eventually disasppear
# import dis; dis.disassemble(co) # DEBUG
# Container for tokens
tokens = []
self.code = array('B', co.co_code)
self.build_lines_data(co)
self.build_prev_op()
bytecode = dis3.Bytecode(co, opnames)
# Scan for assertions. Later we will
# turn 'LOAD_GLOBAL' to 'LOAD_ASSERT' for those
# assertions
self.load_asserts = set()
bs = list(bytecode)
n = len(bs)
for i in range(n):
inst = bs[i]
if inst.opname == 'POP_JUMP_IF_TRUE' and i+1 < n:
next_inst = bs[i+1]
if (next_inst.opname == 'LOAD_GLOBAL' and
next_inst.argval == 'AssertionError'):
self.load_asserts.add(next_inst.offset)
# Get jump targets
# Format: {target offset: [jump offsets]}
jump_targets = self.find_jump_targets()
for inst in bytecode:
if inst.offset in jump_targets:
jump_idx = 0
for jump_offset in jump_targets[inst.offset]:
tokens.append(Token('COME_FROM', None, repr(jump_offset),
offset='%s_%s' % (inst.offset, jump_idx)))
jump_idx += 1
pass
pass
pattr = inst.argrepr
opname = inst.opname
if opname in ['LOAD_CONST']:
const = inst.argval
if iscode(const):
if const.co_name == '<lambda>':
opname = 'LOAD_LAMBDA'
elif const.co_name == '<genexpr>':
opname = 'LOAD_GENEXPR'
elif const.co_name == '<dictcomp>':
opname = 'LOAD_DICTCOMP'
elif const.co_name == '<setcomp>':
opname = 'LOAD_SETCOMP'
elif const.co_name == '<listcomp>':
opname = 'LOAD_LISTCOMP'
# verify() uses 'pattr' for comparison, since 'attr'
# now holds Code(const) and thus can not be used
# for comparison (todo: think about changing this)
# pattr = 'code_object @ 0x%x %s->%s' %\
# (id(const), const.co_filename, const.co_name)
pattr = '<code_object ' + const.co_name + '>'
else:
pattr = const
pass
elif opname == 'MAKE_FUNCTION':
argc = inst.argval
attr = ((argc & 0xFF), (argc >> 8) & 0xFF, (argc >> 16) & 0x7FFF)
pos_args, name_pair_args, annotate_args = attr
if name_pair_args > 0:
opname = 'MAKE_FUNCTION_N%d' % name_pair_args
pass
if annotate_args > 0:
opname = '%s_A_%d' % [opname, annotate_args]
pass
opname = '%s_%d' % (opname, pos_args)
pattr = ("%d positional, %d keyword pair, %d annotated" %
(pos_args, name_pair_args, annotate_args))
tokens.append(
Token(
type_ = opname,
attr = (pos_args, name_pair_args, annotate_args),
pattr = pattr,
offset = inst.offset,
linestart = inst.starts_line)
)
continue
elif opname in ('BUILD_LIST', 'BUILD_TUPLE', 'BUILD_SET', 'BUILD_SLICE',
'BUILD_MAP', 'UNPACK_SEQUENCE', 'MAKE_CLOSURE',
'RAISE_VARARGS'
):
pos_args = inst.argval
opname = '%s_%d' % (opname, pos_args)
elif opname == 'JUMP_ABSOLUTE':
pattr = inst.argval
target = self.get_target(inst.offset)
if target < inst.offset:
next_opname = opnames[self.code[inst.offset+3]]
if (inst.offset in self.stmts and
next_opname not in ('END_FINALLY', 'POP_BLOCK')
and inst.offset not in self.not_continue):
opname = 'CONTINUE'
else:
opname = 'JUMP_BACK'
elif inst.offset in self.load_asserts:
opname = 'LOAD_ASSERT'
tokens.append(
Token(
type_ = opname,
attr = inst.argval,
pattr = pattr,
offset = inst.offset,
linestart = inst.starts_line,
)
)
pass
return tokens, {}
def disassemble3_native(self, co, opnames, classname=None, code_objects={}):
"""
Like disassemble3 but doesn't try to adjust any opcodes.
"""
# Container for tokens
tokens = []
self.code = array('B', co.co_code)
bytecode = dis3.Bytecode(co, opnames)
for inst in bytecode:
pattr = inst.argrepr
opname = inst.opname
tokens.append(
Token(
type_ = opname,
attr = inst.argval,
pattr = pattr,
offset = inst.offset,
linestart = inst.starts_line,
)
)
pass
return tokens, {}
def disassemble_generic(self, co, classname=None, code_objects={}):
"""
Convert code object <co> into a sequence of tokens.
The below is based on (an older version?) of Python dis.disassemble_bytes().
"""
# dis.disassemble(co) # DEBUG
# Container for tokens
tokens = []
customize = {}
self.code = code = array('B', co.co_code)
codelen = len(code)
self.build_lines_data(co)
self.build_prev_op()
self.code_objects = code_objects
# self.lines contains (block,addrLastInstr)
if classname:
classname = '_' + classname.lstrip('_') + '__'
def unmangle(name):
if name.startswith(classname) and name[-2:] != '__':
return name[len(classname) - 2:]
return name
free = [ unmangle(name) for name in (co.co_cellvars + co.co_freevars) ]
names = [ unmangle(name) for name in co.co_names ]
varnames = [ unmangle(name) for name in co.co_varnames ]
else:
free = co.co_cellvars + co.co_freevars
names = co.co_names
varnames = co.co_varnames
pass
# Scan for assertions. Later we will
# turn 'LOAD_GLOBAL' to 'LOAD_ASSERT' for those
# assertions
self.load_asserts = set()
for i in self.op_range(0, codelen):
if (self.code[i] == POP_JUMP_IF_TRUE and
self.code[i+3] == LOAD_GLOBAL):
if names[self.get_argument(i+3)] == 'AssertionError':
self.load_asserts.add(i+3)
# Get jump targets
# Format: {target offset: [jump offsets]}
jump_targets = self.find_jump_targets()
# contains (code, [addrRefToCode])
last_stmt = self.next_stmt[0]
i = self.next_stmt[last_stmt]
replace = {}
imports = self.all_instr(0, codelen, (IMPORT_NAME, IMPORT_FROM, IMPORT_STAR))
if len(imports) > 1:
last_import = imports[0]
for i in imports[1:]:
if self.lines[last_import].next > i:
if self.code[last_import] == IMPORT_NAME == self.code[i]:
replace[i] = 'IMPORT_NAME_CONT'
last_import = i
# Initialize extended arg at 0. When extended arg op is encountered,
# variable preserved for next cycle and added as arg for next op
extended_arg = 0
for offset in self.op_range(0, codelen):
# Add jump target tokens
if offset in jump_targets:
jump_idx = 0
for jump_offset in jump_targets[offset]:
tokens.append(Token('COME_FROM', None, repr(jump_offset),
offset='%s_%s' % (offset, jump_idx)))
jump_idx += 1
pass
pass
op = code[offset]
op_name = op3.opname[op]
oparg = None; pattr = None
if op >= op3.HAVE_ARGUMENT:
oparg = self.get_argument(offset) + extended_arg
extended_arg = 0
if op == op3.EXTENDED_ARG:
extended_arg = oparg * scan.L65536
continue
if op in op3.hasconst:
const = co.co_consts[oparg]
if not PYTHON3 and isinstance(const, str):
if const in code_objects:
const = code_objects[const]
if iscode(const):
oparg = const
if const.co_name == '<lambda>':
assert op_name == 'LOAD_CONST'
op_name = 'LOAD_LAMBDA'
elif const.co_name == '<genexpr>':
op_name = 'LOAD_GENEXPR'
elif const.co_name == '<dictcomp>':
op_name = 'LOAD_DICTCOMP'
elif const.co_name == '<setcomp>':
op_name = 'LOAD_SETCOMP'
elif const.co_name == '<listcomp>':
op_name = 'LOAD_LISTCOMP'
# verify() uses 'pattr' for comparison, since 'attr'
# now holds Code(const) and thus can not be used
# for comparison (todo: think about changing this)
# pattr = 'code_object @ 0x%x %s->%s' %\
# (id(const), const.co_filename, const.co_name)
pattr = '<code_object ' + const.co_name + '>'
else:
pattr = const
elif op in op3.hasname:
pattr = names[oparg]
elif op in op3.hasjrel:
pattr = repr(offset + 3 + oparg)
elif op in op3.hasjabs:
pattr = repr(oparg)
elif op in op3.haslocal:
pattr = varnames[oparg]
elif op in op3.hascompare:
pattr = op3.cmp_op[oparg]
elif op in op3.hasfree:
pattr = free[oparg]
if op_name == 'MAKE_FUNCTION':
argc = oparg
attr = ((argc & 0xFF), (argc >> 8) & 0xFF, (argc >> 16) & 0x7FFF)
pos_args, name_pair_args, annotate_args = attr
if name_pair_args > 0:
op_name = 'MAKE_FUNCTION_N%d' % name_pair_args
pass
if annotate_args > 0:
op_name = '%s_A_%d' % [op_name, annotate_args]
pass
op_name = '%s_%d' % (op_name, pos_args)
pattr = ("%d positional, %d keyword pair, %d annotated" %
(pos_args, name_pair_args, annotate_args))
tokens.append(
Token(
type_ = op_name,
attr = (pos_args, name_pair_args, annotate_args),
pattr = pattr,
offset = offset,
linestart = linestart)
)
continue
elif op_name in ('BUILD_LIST', 'BUILD_TUPLE', 'BUILD_SET', 'BUILD_SLICE',
'UNPACK_SEQUENCE',
'MAKE_FUNCTION', 'CALL_FUNCTION', 'MAKE_CLOSURE',
'CALL_FUNCTION_VAR', 'CALL_FUNCTION_KW',
'CALL_FUNCTION_VAR_KW', 'RAISE_VARARGS'
):
# CALL_FUNCTION OP renaming is done as a custom rule in parse3
if op_name not in ('CALL_FUNCTION', 'CALL_FUNCTION_VAR',
'CALL_FUNCTION_VAR_KW', 'CALL_FUNCTION_KW',
):
op_name = '%s_%d' % (op_name, oparg)
if op_name != 'BUILD_SLICE':
customize[op_name] = oparg
elif op_name == 'JUMP_ABSOLUTE':
target = self.get_target(offset)
if target < offset:
if (offset in self.stmts
and self.code[offset+3] not in (END_FINALLY, POP_BLOCK)
and offset not in self.not_continue):
op_name = 'CONTINUE'
else:
op_name = 'JUMP_BACK'
pass
pass
pass
elif op_name == 'JUMP_FORWARD':
# Python 3.5 will optimize out a JUMP_FORWARD to the
# next instruction while Python 3.2 won't. Smplify
# grammar rules working with both 3.2 and 3.5,
# by optimizing the way Python 3.5 does it.
#
# We may however want to consider whether we do
# this in 3.5 or not.
if oparg == 0 and self.version >= 3.5:
tokens.append(Token('NOP', oparg, pattr, offset, linestart))
continue
elif op_name == 'LOAD_GLOBAL':
if offset in self.load_asserts:
op_name = 'LOAD_ASSERT'
if offset in self.linestarts:
linestart = self.linestarts[offset]
else:
linestart = None
if offset not in replace:
tokens.append(Token(op_name, oparg, pattr, offset, linestart))
else:
tokens.append(Token(replace[offset], oparg, pattr, offset, linestart))
pass
# debug:
# for t in tokens:
# print(t)
return tokens, customize
def build_lines_data(self, code_obj):
"""
Generate various line-related helper data.
"""
# Offset: lineno pairs, only for offsets which start line.
# Locally we use list for more convenient iteration using indices
linestarts = list(dis.findlinestarts(code_obj))
self.linestarts = dict(linestarts)
# Plain set with offsets of first ops on line
self.linestart_offsets = set(a for (a, _) in linestarts)
# 'List-map' which shows line number of current op and offset of
# first op on following line, given offset of op as index
self.lines = lines = []
LineTuple = namedtuple('LineTuple', ['l_no', 'next'])
# Iterate through available linestarts, and fill
# the data for all code offsets encountered until
# last linestart offset
_, prev_line_no = linestarts[0]
offset = 0
for start_offset, line_no in linestarts[1:]:
while offset < start_offset:
lines.append(LineTuple(prev_line_no, start_offset))
offset += 1
prev_line_no = line_no
# Fill remaining offsets with reference to last line number
# and code length as start offset of following non-existing line
codelen = len(self.code)
while offset < codelen:
lines.append(LineTuple(prev_line_no, codelen))
offset += 1
def build_prev_op(self):
"""
Compose 'list-map' which allows to jump to previous
op, given offset of current op as index.
"""
code = self.code
codelen = len(code)
self.prev_op = [0]
for offset in self.op_range(0, codelen):
op = code[offset]
for _ in range(self.op_size(op)):
self.prev_op.append(offset)
def op_size(self, op):
"""
Return size of operator with its arguments
for given opcode <op>.
"""
if op < dis.HAVE_ARGUMENT:
return 1
else:
return 3
def find_jump_targets(self):
"""
Detect all offsets in a byte code which are jump targets.
Return the list of offsets.
This procedure is modelled after dis.findlabels(), but here
for each target the number of jumps is counted.
"""
code = self.code
n = len(code)
self.structs = [{'type': 'root',
'start': 0,
'end': n-1}]
# All loop entry points
self.loops = []
# Map fixed jumps to their real destination
self.fixed_jumps = {}
self.ignore_if = set()
self.build_statement_indices()
# Containers filled by detect_structure()
self.not_continue = set()
self.return_end_ifs = set()
targets = {}
for offset in self.op_range(0, n):
op = code[offset]
# Determine structures and fix jumps in Python versions
# since 2.3
self.detect_structure(offset)
if op >= op3.HAVE_ARGUMENT:
label = self.fixed_jumps.get(offset)
oparg = code[offset+1] + code[offset+2] * 256
if label is None:
if op in op3.hasjrel and op != FOR_ITER:
label = offset + self.op_size(op) + oparg
elif op in op3.hasjabs:
if op in (JUMP_IF_FALSE_OR_POP, JUMP_IF_TRUE_OR_POP):
if oparg > offset:
label = oparg
if label is not None and label != -1:
targets[label] = targets.get(label, []) + [offset]
elif op == END_FINALLY and offset in self.fixed_jumps:
label = self.fixed_jumps[offset]
targets[label] = targets.get(label, []) + [offset]
return targets
def build_statement_indices(self):
code = self.code
start = 0
end = codelen = len(code)
statement_opcodes = set([
SETUP_LOOP, BREAK_LOOP, CONTINUE_LOOP,
SETUP_FINALLY, END_FINALLY, SETUP_EXCEPT, SETUP_WITH,
POP_BLOCK, STORE_FAST, DELETE_FAST, STORE_DEREF,
STORE_GLOBAL, DELETE_GLOBAL, STORE_NAME, DELETE_NAME,
STORE_ATTR, DELETE_ATTR, STORE_SUBSCR, DELETE_SUBSCR,
RETURN_VALUE, RAISE_VARARGS, POP_TOP, PRINT_EXPR,
JUMP_ABSOLUTE
])
statement_opcode_sequences = [(POP_JUMP_IF_FALSE, JUMP_FORWARD), (POP_JUMP_IF_FALSE, JUMP_ABSOLUTE),
(POP_JUMP_IF_TRUE, JUMP_FORWARD), (POP_JUMP_IF_TRUE, JUMP_ABSOLUTE)]
designator_ops = set([
STORE_FAST, STORE_NAME, STORE_GLOBAL, STORE_DEREF, STORE_ATTR,
STORE_SUBSCR, UNPACK_SEQUENCE, JUMP_ABSOLUTE
])
# Compose preliminary list of indices with statements,
# using plain statement opcodes
prelim = self.all_instr(start, end, statement_opcodes)
# Initialize final container with statements with
# preliminnary data
stmts = self.stmts = set(prelim)
# Same for opcode sequences
pass_stmts = set()
for sequence in statement_opcode_sequences:
for i in self.op_range(start, end-(len(sequence)+1)):
match = True
for elem in sequence:
if elem != code[i]:
match = False
break
i += self.op_size(code[i])
if match is True:
i = self.prev_op[i]
stmts.add(i)
pass_stmts.add(i)
# Initialize statement list with the full data we've gathered so far
if pass_stmts:
stmt_offset_list = list(stmts)
stmt_offset_list.sort()
else:
stmt_offset_list = prelim
# 'List-map' which contains offset of start of
# next statement, when op offset is passed as index
self.next_stmt = slist = []
last_stmt_offset = -1
i = 0
# Go through all statement offsets
for stmt_offset in stmt_offset_list:
# Process absolute jumps, but do not remove 'pass' statements
# from the set
if code[stmt_offset] == JUMP_ABSOLUTE and stmt_offset not in pass_stmts:
# If absolute jump occurs in forward direction or it takes off from the
# same line as previous statement, this is not a statement
target = self.get_target(stmt_offset)
if target > stmt_offset or self.lines[last_stmt_offset].l_no == self.lines[stmt_offset].l_no:
stmts.remove(stmt_offset)
continue
# Rewing ops till we encounter non-JA one
j = self.prev_op[stmt_offset]
while code[j] == JUMP_ABSOLUTE:
j = self.prev_op[j]
# If we got here, then it's list comprehension which
# is not a statement too
if code[j] == LIST_APPEND:
stmts.remove(stmt_offset)
continue
# Exclude ROT_TWO + POP_TOP
elif code[stmt_offset] == POP_TOP and code[self.prev_op[stmt_offset]] == ROT_TWO:
stmts.remove(stmt_offset)
continue
# Exclude FOR_ITER + designators
elif code[stmt_offset] in designator_ops:
j = self.prev_op[stmt_offset]
while code[j] in designator_ops:
j = self.prev_op[j]
if code[j] == FOR_ITER:
stmts.remove(stmt_offset)
continue
# Add to list another list with offset of current statement,
# equal to length of previous statement
slist += [stmt_offset] * (stmt_offset-i)
last_stmt_offset = stmt_offset
i = stmt_offset
# Finish filling the list for last statement
slist += [codelen] * (codelen-len(slist))
def get_target(self, offset):
"""
Get target offset for op located at given <offset>.
"""
op = self.code[offset]
target = self.code[offset+1] + self.code[offset+2] * 256
if op in op3.hasjrel:
target += offset + 3
return target
def detect_structure(self, offset):
"""
Detect structures and their boundaries to fix optimized jumps
in python2.3+
"""
# TODO: check the struct boundaries more precisely -Dan
code = self.code
op = code[offset]
# Detect parent structure
parent = self.structs[0]
start = parent['start']
end = parent['end']
# Pick inner-most parent for our offset
for struct in self.structs:
curent_start = struct['start']
curent_end = struct['end']
if (curent_start <= offset < curent_end) and (curent_start >= start and curent_end <= end):
start = curent_start
end = curent_end
parent = struct
if op == SETUP_LOOP:
start = offset+3
target = self.get_target(offset)
end = self.restrict_to_parent(target, parent)
if target != end:
self.fixed_jumps[offset] = end
(line_no, next_line_byte) = self.lines[offset]
jump_back = self.last_instr(start, end, JUMP_ABSOLUTE,
next_line_byte, False)
if jump_back and jump_back != self.prev_op[end] and code[jump_back+3] in (JUMP_ABSOLUTE, JUMP_FORWARD):
if code[self.prev_op[end]] == RETURN_VALUE or \
(code[self.prev_op[end]] == POP_BLOCK and code[self.prev_op[self.prev_op[end]]] == RETURN_VALUE):
jump_back = None
if not jump_back: # loop suite ends in return. wtf right?
jump_back = self.last_instr(start, end, RETURN_VALUE) + 1
if not jump_back:
return
if code[self.prev_op[next_line_byte]] not in (PJIF, PJIT):
loop_type = 'for'
else:
loop_type = 'while'
self.ignore_if.add(self.prev_op[next_line_byte])
target = next_line_byte
end = jump_back + 3
else:
if self.get_target(jump_back) >= next_line_byte:
jump_back = self.last_instr(start, end, JUMP_ABSOLUTE, start, False)
if end > jump_back+4 and code[end] in (JUMP_FORWARD, JUMP_ABSOLUTE):
if code[jump_back+4] in (JUMP_ABSOLUTE, JUMP_FORWARD):
if self.get_target(jump_back+4) == self.get_target(end):
self.fixed_jumps[offset] = jump_back+4
end = jump_back+4
elif target < offset:
self.fixed_jumps[offset] = jump_back+4
end = jump_back+4
target = self.get_target(jump_back)
if code[target] in (FOR_ITER, GET_ITER):
loop_type = 'for'
else:
loop_type = 'while'
test = self.prev_op[next_line_byte]
if test == offset:
loop_type = 'while 1'
elif self.code[test] in op3.hasjabs+op3.hasjrel:
self.ignore_if.add(test)
test_target = self.get_target(test)
if test_target > (jump_back+3):
jump_back = test_target
self.not_continue.add(jump_back)
self.loops.append(target)
self.structs.append({'type': loop_type + '-loop',
'start': target,
'end': jump_back})
if jump_back+3 != end:
self.structs.append({'type': loop_type + '-else',
'start': jump_back+3,
'end': end})
elif op in (POP_JUMP_IF_FALSE, POP_JUMP_IF_TRUE):
start = offset + self.op_size(op)
target = self.get_target(offset)
rtarget = self.restrict_to_parent(target, parent)
prev_op = self.prev_op
# Do not let jump to go out of parent struct bounds
if target != rtarget and parent['type'] == 'and/or':
self.fixed_jumps[offset] = rtarget
return
# Does this jump to right after another cond jump that is
# not myself? If so, it's part of a larger conditional.
# rocky: if we have a conditional jump to the next instruction, then
# possibly I am "skipping over" a "pass" or null statement.
if ((code[prev_op[target]] in
(JUMP_IF_FALSE_OR_POP, JUMP_IF_TRUE_OR_POP,
POP_JUMP_IF_FALSE, POP_JUMP_IF_TRUE)) and
(target > offset) and prev_op[target] != offset):
self.fixed_jumps[offset] = prev_op[target]
self.structs.append({'type': 'and/or',
'start': start,
'end': prev_op[target]})
return
# Is it an and inside if block
if op == POP_JUMP_IF_FALSE:
# Search for other POP_JUMP_IF_FALSE targetting the same op,
# in current statement, starting from current offset, and filter
# everything inside inner 'or' jumps and midline ifs
match = self.rem_or(start, self.next_stmt[offset], POP_JUMP_IF_FALSE, target)
match = self.remove_mid_line_ifs(match)
# If we still have any offsets in set, start working on it
if match:
if (code[prev_op[rtarget]] in (JUMP_FORWARD, JUMP_ABSOLUTE) and prev_op[rtarget] not in self.stmts and
self.restrict_to_parent(self.get_target(prev_op[rtarget]), parent) == rtarget):
if (code[prev_op[prev_op[rtarget]]] == JUMP_ABSOLUTE and self.remove_mid_line_ifs([offset]) and
target == self.get_target(prev_op[prev_op[rtarget]]) and
(prev_op[prev_op[rtarget]] not in self.stmts or self.get_target(prev_op[prev_op[rtarget]]) > prev_op[prev_op[rtarget]]) and
1 == len(self.remove_mid_line_ifs(self.rem_or(start, prev_op[prev_op[rtarget]], (POP_JUMP_IF_FALSE, POP_JUMP_IF_TRUE), target)))):
pass
elif (code[prev_op[prev_op[rtarget]]] == RETURN_VALUE and self.remove_mid_line_ifs([offset]) and
1 == (len(set(self.remove_mid_line_ifs(self.rem_or(start, prev_op[prev_op[rtarget]],
(POP_JUMP_IF_FALSE, POP_JUMP_IF_TRUE), target))) |
set(self.remove_mid_line_ifs(self.rem_or(start, prev_op[prev_op[rtarget]],
(POP_JUMP_IF_FALSE, POP_JUMP_IF_TRUE, JUMP_ABSOLUTE),
prev_op[rtarget], True)))))):
pass
else:
fix = None
jump_ifs = self.all_instr(start, self.next_stmt[offset], POP_JUMP_IF_FALSE)
last_jump_good = True
for j in jump_ifs:
if target == self.get_target(j):
if self.lines[j].next == j + 3 and last_jump_good:
fix = j
break
else:
last_jump_good = False
self.fixed_jumps[offset] = fix or match[-1]
return
else:
self.fixed_jumps[offset] = match[-1]
return
# op == POP_JUMP_IF_TRUE
else:
next = self.next_stmt[offset]
if prev_op[next] == offset:
pass
elif code[next] in (JUMP_FORWARD, JUMP_ABSOLUTE) and target == self.get_target(next):
if code[prev_op[next]] == POP_JUMP_IF_FALSE:
if code[next] == JUMP_FORWARD or target != rtarget or code[prev_op[prev_op[rtarget]]] not in (JUMP_ABSOLUTE, RETURN_VALUE):
self.fixed_jumps[offset] = prev_op[next]
return
elif (code[next] == JUMP_ABSOLUTE and code[target] in (JUMP_ABSOLUTE, JUMP_FORWARD) and
self.get_target(target) == self.get_target(next)):
self.fixed_jumps[offset] = prev_op[next]
return
# Don't add a struct for a while test, it's already taken care of
if offset in self.ignore_if:
return
if (code[prev_op[rtarget]] == JUMP_ABSOLUTE and prev_op[rtarget] in self.stmts and
prev_op[rtarget] != offset and prev_op[prev_op[rtarget]] != offset and
not (code[rtarget] == JUMP_ABSOLUTE and code[rtarget+3] == POP_BLOCK and code[prev_op[prev_op[rtarget]]] != JUMP_ABSOLUTE)):
rtarget = prev_op[rtarget]
# Does the if jump just beyond a jump op, then this is probably an if statement
if code[prev_op[rtarget]] in (JUMP_ABSOLUTE, JUMP_FORWARD):
if_end = self.get_target(prev_op[rtarget])
# Is this a loop not an if?
if (if_end < prev_op[rtarget]) and (code[prev_op[if_end]] == SETUP_LOOP):
if(if_end > start):
return
end = self.restrict_to_parent(if_end, parent)
self.structs.append({'type': 'if-then',
'start': start,
'end': prev_op[rtarget]})
self.not_continue.add(prev_op[rtarget])
if rtarget < end:
self.structs.append({'type': 'if-else',
'start': rtarget,
'end': end})
elif code[prev_op[rtarget]] == RETURN_VALUE:
self.structs.append({'type': 'if-then',
'start': start,
'end': rtarget})
self.return_end_ifs.add(prev_op[rtarget])
elif op in (JUMP_IF_FALSE_OR_POP, JUMP_IF_TRUE_OR_POP):
target = self.get_target(offset)
if target > offset:
unop_target = self.last_instr(offset, target, JUMP_FORWARD, target)
if unop_target and code[unop_target+3] != ROT_TWO:
self.fixed_jumps[offset] = unop_target
else:
self.fixed_jumps[offset] = self.restrict_to_parent(target, parent)
def next_except_jump(self, start):
"""
Return the next jump that was generated by an except SomeException:
construct in a try...except...else clause or None if not found.
"""
if self.code[start] == DUP_TOP:
except_match = self.first_instr(start, len(self.code), POP_JUMP_IF_FALSE)
if except_match:
jmp = self.prev_op[self.get_target(except_match)]
self.ignore_if.add(except_match)
self.not_continue.add(jmp)
return jmp
count_END_FINALLY = 0
count_SETUP_ = 0
for i in self.op_range(start, len(self.code)):
op = self.code[i]
if op == END_FINALLY:
if count_END_FINALLY == count_SETUP_:
assert self.code[self.prev_op[i]] in (JUMP_ABSOLUTE, JUMP_FORWARD, RETURN_VALUE)
self.not_continue.add(self.prev_op[i])
return self.prev_op[i]
count_END_FINALLY += 1
elif op in (SETUP_EXCEPT, SETUP_WITH, SETUP_FINALLY):
count_SETUP_ += 1
def rem_or(self, start, end, instr, target=None, include_beyond_target=False):
"""
Find offsets of all requested <instr> between <start> and <end>,
optionally <target>ing specified offset, and return list found
<instr> offsets which are not within any POP_JUMP_IF_TRUE jumps.
"""
# Find all offsets of requested instructions
instr_offsets = self.all_instr(start, end, instr, target, include_beyond_target)
# Get all POP_JUMP_IF_TRUE (or) offsets
pjit_offsets = self.all_instr(start, end, POP_JUMP_IF_TRUE)
filtered = []
for pjit_offset in pjit_offsets:
pjit_tgt = self.get_target(pjit_offset) - 3
for instr_offset in instr_offsets:
if instr_offset <= pjit_offset or instr_offset >= pjit_tgt:
filtered.append(instr_offset)
instr_offsets = filtered
filtered = []
return instr_offsets
def remove_mid_line_ifs(self, ifs):
"""
Go through passed offsets, filtering ifs
located somewhere mid-line.
"""
filtered = []
for if_ in ifs:
# For each offset, if line number of current and next op
# is the same
if self.lines[if_].l_no == self.lines[if_+3].l_no:
# Check if last op on line is PJIT or PJIF, and if it is - skip it
if self.code[self.prev_op[self.lines[if_].next]] in (POP_JUMP_IF_TRUE, POP_JUMP_IF_FALSE):
continue
filtered.append(if_)
return filtered
if __name__ == "__main__":
import inspect
co = inspect.currentframe().f_code
from uncompyle6 import PYTHON_VERSION
from opcode import opname
tokens, customize = Scanner3(PYTHON_VERSION).disassemble3(co, opname)
for t in tokens:
print(t)
pass
Reference in New Issue View Git Blame Copy Permalink