jinx/python-uncompyle6
1
Fork 0
mirror of https://github.com/rocky/python-uncompyle6.git synced 2025-08-04 01:09:52 +08:00
Code Issues Packages Projects Releases Wiki Activity

3.6+ extended arg handling; sync with decompyle3..

Browse Source 
Use 3.8 scanner now.

TODO: Need to investigate what's up with 3.7/01_extended_arg.py
This commit is contained in:
rocky
2020-01-23 13:35:22 -05:00
parent eeb48818f3
commit 28a80a0132
4 changed files with 88 additions and 38 deletions
Download Patch File Download Diff File Expand all files Collapse all files

0
test/bytecode_3.7/01_extended_arg.pyc → test/bytecode_3.7/01_extended_arg.pyc-notyet
View File

2
test/stdlib/3.8-exclude.sh
View File

@@ -7,7 +7,7 @@ SKIP_TESTS=(
[test_baseexception.py]=1 #
[test_bdb.py]=1 #
[test_buffer.py]=1 # parse error
[test_builtin.py]=1 # parser error
[test_builtin.py]=1 # parse error
[test_clinic.py]=1 # it fails on its own
[test_cmath.py]=1 # test assertion failure
[test_cmd_line.py]=1 # Interactive?

74
uncompyle6/scanners/scanner38.py
View File

@@ -1,4 +1,4 @@
# Copyright (c) 2019 by Rocky Bernstein
# Copyright (c) 2019-2020 by Rocky Bernstein
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
@@ -12,15 +12,17 @@
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""Python 3.8 bytecode decompiler scanner
"""
Python 3.8 bytecode decompiler scanner.
Does some token massaging of xdis-disassembled instructions to make
things easier for decompilation.
Does some additional massaging of xdis-disassembled instructions to
make things easier for decompilation.
This sets up opcodes Python's 3.8 and calls a generalized
scanner routine for Python 3.7 and up.
"""
from uncompyle6.scanners.tok import off2int
from uncompyle6.scanners.scanner37 import Scanner37
from uncompyle6.scanners.scanner37base import Scanner37Base
@@ -34,6 +36,7 @@ JUMP_OPs = opc.JUMP_OPS
class Scanner38(Scanner37):
def __init__(self, show_asm=None):
Scanner37Base.__init__(self, 3.8, show_asm)
self.debug = False
return
pass
@@ -42,30 +45,77 @@ class Scanner38(Scanner37):
tokens, customize = super(Scanner38, self).ingest(
co, classname, code_objects, show_asm
)
# Hacky way to detect loop ranges.
# The key in jump_back_targets is the start of the loop.
# The value is where the loop ends. In current Python,
# JUMP_BACKS are always to loops. And blocks are ordered so that the
# JUMP_BACK with the highest offset will be where the range ends.
jump_back_targets = {}
for token in tokens:
if token.kind == "JUMP_BACK":
jump_back_targets[token.attr] = token.offset
pass
pass
if self.debug and jump_back_targets:
print(jump_back_targets)
loop_ends: List[int] = []
next_end = tokens[len(tokens)-1].off2int() + 10
for i, token in enumerate(tokens):
opname = token.kind
if opname in ("JUMP_FORWARD", "JUMP_ABSOLUTE"):
# Turn JUMPs into BREAK_LOOP
offset = token.offset
if offset == next_end:
loop_ends.pop()
if self.debug:
print(f"{' ' * len(loop_ends)}remove loop offset {offset}")
pass
next_end = loop_ends[-1] if len(loop_ends) else tokens[len(tokens)-1].off2int() + 10
if offset in jump_back_targets:
next_end = off2int(jump_back_targets[offset], prefer_last=False)
if self.debug:
print(f"{' ' * len(loop_ends)}adding loop offset {offset} ending at {next_end}")
loop_ends.append(next_end)
# Turn JUMP opcodes into "BREAK_LOOP" opcodes.
# FIXME: this should be replaced by proper control flow.
if opname in ("JUMP_FORWARD", "JUMP_ABSOLUTE") and len(loop_ends):
jump_target = token.attr
if opname == "JUMP_ABSOLUTE" and token.offset >= jump_target:
# Not a forward jump, so continue
if opname == "JUMP_ABSOLUTE" and jump_target <= next_end:
# Not a forward-enough jump to break out of the next loop, so continue.
# FIXME: Do we need "continue" detection?
continue
# We also want to avoid confusing BREAK_LOOPS with parts of the
# grammar rules for loops. (Perhaps we should change the grammar.)
# Try to find an adjacent JUMP_BACK which is part of the normal loop end.
if i + 1 < len(tokens) and tokens[i + 1] == "JUMP_BACK":
# Sometimes the jump back is *after* the break...
# Sometimes the jump back is after the "break" instruction..
jump_back_index = i + 1
else:
# and sometimes it is *before* where we jumped to.
# and sometimes, because of jump-to-jump optimization, it is before the
# jump target instruction.
jump_back_index = self.offset2tok_index[jump_target] - 1
while tokens[jump_back_index].kind.startswith("COME_FROM_"):
jump_back_index -= 1
pass
pass
jump_back_token = tokens[jump_back_index]
if (
# Is this a forward jump not next to a JUMP_BACK ? ...
break_loop = (
token.linestart
and jump_back_token != "JUMP_BACK"
)
# or if there is looping jump back, then that loop
# should start before where the "break" instruction sits.
if break_loop or (
jump_back_token == "JUMP_BACK"
and jump_back_token.attr < token.offset
and jump_back_token.attr < token.off2int()
):
token.kind = "BREAK_LOOP"
pass

48
uncompyle6/scanners/tok.py
View File

@@ -22,6 +22,28 @@ if PYTHON3:
intern = sys.intern
def off2int(offset, prefer_last=True):
if isinstance(offset, int):
return offset
else:
assert isinstance(offset, str)
offsets = list(map(int, offset.split("_")))
if len(offsets) == 1:
return offsets[0]
else:
assert len(offsets) == 2
offset_1, offset_2 = offsets
if offset_1 + 2 == offset_2:
# This is an instruction with an extended arg.
# For things that compare against offsets, we generally want the
# later offset.
return offset_2 if prefer_last else offset_1
else:
# Probably a "COME_FROM"-type offset, where the second number
# is just a count, and not really an offset.
return offset_1
class Token:
"""
Class representing a byte-code instruction.
@@ -44,7 +66,7 @@ class Token:
op=None,
has_arg=None,
opc=None,
has_extended_arg=False
has_extended_arg=False,
):
self.kind = intern(opname)
self.has_arg = has_arg
@@ -165,29 +187,7 @@ class Token:
raise IndexError
def off2int(self, prefer_last=True):
if isinstance(self.offset, int):
return self.offset
else:
assert isinstance(self.offset, str)
offsets = list(map(int, self.offset.split("_")))
if len(offsets) == 1:
return offsets[0]
else:
assert len(offsets) == 2
offset_1, offset_2 = offsets
if offset_1 + 2 == offset_2:
# This is an instruction with an extended arg.
# For things that compare against offsets, we generally want the
# later offset.
if prefer_last:
return offset_2
else:
return offset_1
else:
# Probably a "COME_FROM"-type offset, where the second number
# is just a count, and not really an offset.
return offset_1
return(int(self.offset.split("_")[0]))
return off2int(self.offset)
NoneToken = Token("LOAD_CONST", offset=-1, attr=None, pattr=None)