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python-uncompyle6/uncompyle6/semantics/pysource.py
rocky 8cdf741b62 Bugs in long-literal handlin 
Move n_dict to n_actions and special case n_const_list.
Generalize build_collection out of 3.7+ and into all Pythons
2022-04-24 17:38:35 -04:00

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# Copyright (c) 2015-2022 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
#
# 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
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""Creates Python source code from an uncompyle6 parse tree.
The terminal symbols are CPython bytecode instructions. (See the
python documentation under module "dis" for a list of instructions
and what they mean).
Upper levels of the grammar is a more-or-less conventional grammar for
Python.
"""
# The below is a bit long, but still it is somewhat abbreviated.
# See https://github.com/rocky/python-uncompyle6/wiki/Table-driven-semantic-actions.
# for a more complete explanation, nicely marked up and with examples.
#
#
# Semantic action rules for nonterminal symbols can be specified here by
# creating a method prefaced with "n_" for that nonterminal. For
# example, "n_exec_stmt" handles the semantic actions for the
# "exec_stmt" nonterminal symbol. Similarly if a method with the name
# of the nonterminal is suffixed with "_exit" it will be called after
# all of its children are called.
#
# After a while writing methods this way, you'll find many routines which do similar
# sorts of things, and soon you'll find you want a short notation to
# describe rules and not have to create methods at all.
#
# So another other way to specify a semantic rule for a nonterminal is via
# either tables MAP_R, or MAP_DIRECT where the key is the
# nonterminal name.
#
# These dictionaries use a printf-like syntax to direct substitution
# from attributes of the nonterminal and its children..
#
# The rest of the below describes how table-driven semantic actions work
# and gives a list of the format specifiers. The default() and
# template_engine() methods implement most of the below.
#
# We allow for a couple of ways to interact with a node in a tree. So
# step 1 after not seeing a custom method for a nonterminal is to
# determine from what point of view tree-wise the rule is applied.
# In the diagram below, N is a nonterminal name, and K also a nonterminal
# name but the one used as a key in the table.
# we show where those are with respect to each other in the
# parse tree for N.
#
#
# N&K N
# / | ... \ / | ... \
# O O O O O K
#
#
# TABLE_DIRECT TABLE_R
#
# The default table is TABLE_DIRECT mapping By far, most rules used work this way.
#
# The key K is then extracted from the subtree and used to find one
# of the tables, T listed above. The result after applying T[K] is
# a format string and arguments (a la printf()) for the formatting
# engine.
#
# Escapes in the format string are:
#
# %c evaluate/traverse the node recursively. Its argument is a single
# integer or tuple representing a node index.
# If a tuple is given, the first item is the node index while
# the second item is a string giving the node/noterminal name.
# This name will be checked at runtime against the node type.
#
# %p like %c but sets the operator precedence.
# Its argument then is a tuple indicating the node
# index and the precedence value, an integer. If 3 items are given,
# the second item is the nonterminal name and the precedence is given last.
#
# %C evaluate/travers children recursively, with sibling children separated by the
# given string. It needs a 3-tuple: a starting node, the maximimum
# value of an end node, and a string to be inserted between sibling children
#
# %, Append ',' if last %C only printed one item. This is mostly for tuples
# on the LHS of an assignment statement since BUILD_TUPLE_n pretty-prints
# other tuples. The specifier takes no arguments
#
# %P same as %C but sets operator precedence. Its argument is a 4-tuple:
# the node low and high indices, the separator, a string the precidence
# value, an integer.
#
# %D Same as `%C` this is for left-recursive lists like kwargs where goes
# to epsilon at the beginning. It needs a 3-tuple: a starting node, the
# maximimum value of an end node, and a string to be inserted between
# sibling children. If we were to use `%C` an extra separator with an
# epsilon would appear at the beginning.
#
# %| Insert spaces to the current indentation level. Takes no arguments.
#
# %+ increase current indentation level. Takes no arguments.
#
# %- decrease current indentation level. Takes no arguments.
#
# %{EXPR} Python eval(EXPR) in context of node. Takes no arguments
#
# %[N]{EXPR} Python eval(EXPR) in context of node[N]. Takes no arguments
#
# %[N]{%X} evaluate/recurse on child node[N], using specifier %X.
# %X can be one of the above, e.g. %c, %p, etc. Takes the arguemnts
# that the specifier uses.
#
# %% literal '%'. Takes no arguments.
#
#
# The '%' may optionally be followed by a number (C) in square
# brackets, which makes the template_engine walk down to N[C] before
# evaluating the escape code.
import sys
IS_PYPY = "__pypy__" in sys.builtin_module_names
from xdis import iscode, COMPILER_FLAG_BIT
from xdis.version_info import PYTHON_VERSION_TRIPLE
from uncompyle6.parser import get_python_parser
from uncompyle6.parsers.treenode import SyntaxTree
from spark_parser import GenericASTTraversal
from uncompyle6.scanner import Code, get_scanner
import uncompyle6.parser as python_parser
from uncompyle6.semantics.check_ast import checker
from uncompyle6.semantics.make_function2 import make_function2
from uncompyle6.semantics.make_function3 import make_function3
from uncompyle6.semantics.make_function36 import make_function36
from uncompyle6.semantics.parser_error import ParserError
from uncompyle6.semantics.customize import customize_for_version
from uncompyle6.semantics.gencomp import ComprehensionMixin
from uncompyle6.semantics.helper import (
print_docstring,
find_code_node,
find_globals_and_nonlocals,
flatten_list,
)
from uncompyle6.scanners.tok import Token
from uncompyle6.semantics.n_actions import NonterminalActions
from uncompyle6.semantics.transform import is_docstring, TreeTransform
from uncompyle6.semantics.consts import (
ASSIGN_DOC_STRING,
ASSIGN_TUPLE_PARAM,
INDENT_PER_LEVEL,
LINE_LENGTH,
MAP,
MAP_DIRECT,
NAME_MODULE,
NONE,
PASS,
PRECEDENCE,
RETURN_LOCALS,
RETURN_NONE,
TAB,
TABLE_R,
escape,
minint,
)
from uncompyle6.show import maybe_show_tree
from uncompyle6.util import better_repr
DEFAULT_DEBUG_OPTS = {"asm": False, "tree": False, "grammar": False}
def unicode(x): return x
from io import StringIO
PARSER_DEFAULT_DEBUG = {
"rules": False,
"transition": False,
"reduce": False,
"errorstack": "full",
"context": True,
"dups": False,
}
TREE_DEFAULT_DEBUG = {"before": False, "after": False}
DEFAULT_DEBUG_OPTS = {
"asm": False,
"tree": TREE_DEFAULT_DEBUG,
"grammar": dict(PARSER_DEFAULT_DEBUG),
}
class SourceWalkerError(Exception):
def __init__(self, errmsg):
self.errmsg = errmsg
def __str__(self):
return self.errmsg
class SourceWalker(GenericASTTraversal, NonterminalActions, ComprehensionMixin):
stacked_params = ("f", "indent", "is_lambda", "_globals")
def __init__(
self,
version,
out,
scanner,
showast=TREE_DEFAULT_DEBUG,
debug_parser=PARSER_DEFAULT_DEBUG,
compile_mode="exec",
is_pypy=IS_PYPY,
linestarts={},
tolerate_errors=False,
):
"""`version' is the Python version (a float) of the Python dialect
of both the syntax tree and language we should produce.
`out' is IO-like file pointer to where the output should go. It
whould have a getvalue() method.
`scanner' is a method to call when we need to scan tokens. Sometimes
in producing output we will run across further tokens that need
to be scaned.
If `showast' is True, we print the syntax tree.
`compile_mode' is is either 'exec' or 'single'. It is the compile
mode that was used to create the Syntax Tree and specifies a
gramar variant within a Python version to use.
`is_pypy` should be True if the Syntax Tree was generated for PyPy.
`linestarts` is a dictionary of line number to bytecode offset. This
can sometimes assist in determinte which kind of source-code construct
to use when there is ambiguity.
"""
GenericASTTraversal.__init__(self, ast=None)
self.scanner = scanner
params = {"f": out, "indent": ""}
self.version = version
self.p = get_python_parser(
version,
debug_parser=dict(debug_parser),
compile_mode=compile_mode,
is_pypy=is_pypy,
)
# Initialize p_lambda on demand
self.p_lambda = None
self.treeTransform = TreeTransform(version=self.version, show_ast=showast)
self.debug_parser = dict(debug_parser)
self.showast = showast
self.params = params
self.param_stack = []
self.ERROR = None
self.prec = 100
self.return_none = False
self.mod_globs = set()
self.currentclass = None
self.classes = []
self.pending_newlines = 0
self.linestarts = linestarts
self.line_number = 1
self.ast_errors = []
# FIXME: have p.insts update in a better way
# modularity is broken here
self.insts = scanner.insts
self.offset2inst_index = scanner.offset2inst_index
# This is in Python 2.6 on. It changes the way
# strings get interpreted. See n_LOAD_CONST
self.FUTURE_UNICODE_LITERALS = False
# Sometimes we may want to continue decompiling when there are errors
# and sometimes not
self.tolerate_errors = tolerate_errors
# If we are in a 3.6+ format string, we may need an
# extra level of parens when seeing a lambda. We also use
# this to understand whether or not to add the "f" prefix.
# When not "None" it is a string of the last nonterminal
# that started the format string
self.in_format_string = None
# hide_internal suppresses displaying the additional instructions that sometimes
# exist in code but but were not written in the source code.
# An example is:
# __module__ = __name__
self.hide_internal = True
self.compile_mode = compile_mode
self.name = None
self.version = version
self.is_pypy = is_pypy
customize_for_version(self, is_pypy, version)
return
def maybe_show_tree(self, ast, phase):
if self.showast.get("before", False):
self.println(
"""
---- end before transform
"""
)
if self.showast.get("after", False):
self.println(
"""
---- begin after transform
"""
+ " "
)
if self.showast.get(phase, False):
maybe_show_tree(self, ast)
def str_with_template(self, ast) -> str:
stream = sys.stdout
stream.write(self.str_with_template1(ast, "", None))
stream.write("\n")
def str_with_template1(self, ast, indent, sibNum=None) -> str:
rv = str(ast.kind)
if sibNum is not None:
rv = "%2d. %s" % (sibNum, rv)
enumerate_children = False
if len(ast) > 1:
rv += f" ({len(ast)})"
enumerate_children = True
if ast in PRECEDENCE:
rv += f", precedence {PRECEDENCE[ast]}"
mapping = self._get_mapping(ast)
table = mapping[0]
key = ast
for i in mapping[1:]:
key = key[i]
pass
if ast.transformed_by is not None:
if ast.transformed_by is True:
rv += " transformed"
else:
rv += " transformed by %s" % ast.transformed_by
pass
pass
if key.kind in table:
rv += ": %s" % str(table[key.kind])
rv = indent + rv
indent += " "
i = 0
for node in ast:
if hasattr(node, "__repr1__"):
if enumerate_children:
child = self.str_with_template1(node, indent, i)
else:
child = self.str_with_template1(node, indent, None)
else:
inst = node.format(line_prefix="L.")
if inst.startswith("\n"):
# Nuke leading \n
inst = inst[1:]
if enumerate_children:
child = indent + "%2d. %s" % (i, inst)
else:
child = indent + inst
pass
rv += "\n" + child
i += 1
return rv
def indent_if_source_nl(self, line_number, indent):
if line_number != self.line_number:
self.write("\n" + self.indent + INDENT_PER_LEVEL[:-1])
return self.line_number
f = property(
lambda s: s.params["f"],
lambda s, x: s.params.__setitem__("f", x),
lambda s: s.params.__delitem__("f"),
None,
)
indent = property(
lambda s: s.params["indent"],
lambda s, x: s.params.__setitem__("indent", x),
lambda s: s.params.__delitem__("indent"),
None,
)
is_lambda = property(
lambda s: s.params["is_lambda"],
lambda s, x: s.params.__setitem__("is_lambda", x),
lambda s: s.params.__delitem__("is_lambda"),
None,
)
_globals = property(
lambda s: s.params["_globals"],
lambda s, x: s.params.__setitem__("_globals", x),
lambda s: s.params.__delitem__("_globals"),
None,
)
def set_pos_info(self, node):
if hasattr(node, "linestart") and node.linestart:
self.line_number = node.linestart
def preorder(self, node=None):
super(SourceWalker, self).preorder(node)
self.set_pos_info(node)
def indent_more(self, indent=TAB):
self.indent += indent
def indent_less(self, indent=TAB):
self.indent = self.indent[: -len(indent)]
def traverse(self, node, indent=None, is_lambda=False):
self.param_stack.append(self.params)
if indent is None:
indent = self.indent
p = self.pending_newlines
self.pending_newlines = 0
self.params = {
"_globals": {},
"_nonlocals": {}, # Python 3 has nonlocal
"f": StringIO(),
"indent": indent,
"is_lambda": is_lambda,
}
self.preorder(node)
self.f.write("\n" * self.pending_newlines)
result = self.f.getvalue()
self.params = self.param_stack.pop()
self.pending_newlines = p
return result
def write(self, *data):
if (len(data) == 0) or (len(data) == 1 and data[0] == ""):
return
out = "".join((str(j) for j in data))
n = 0
for i in out:
if i == "\n":
n += 1
if n == len(out):
self.pending_newlines = max(self.pending_newlines, n)
return
elif n:
self.pending_newlines = max(self.pending_newlines, n)
out = out[n:]
break
else:
break
if self.pending_newlines > 0:
self.f.write("\n" * self.pending_newlines)
self.pending_newlines = 0
for i in out[::-1]:
if i == "\n":
self.pending_newlines += 1
else:
break
if self.pending_newlines:
out = out[: -self.pending_newlines]
self.f.write(out)
def println(self, *data):
if data and not (len(data) == 1 and data[0] == ""):
self.write(*data)
self.pending_newlines = max(self.pending_newlines, 1)
def is_return_none(self, node):
# Is there a better way?
ret = (
node[0] == "return_expr"
and node[0][0] == "expr"
and node[0][0][0] == "LOAD_CONST"
and node[0][0][0].pattr is None
)
if self.version <= (2, 6):
return ret
else:
# FIXME: should the SyntaxTree expression be folded into
# the global RETURN_NONE constant?
return ret or node == SyntaxTree(
"return", [SyntaxTree("return_expr", [NONE]), Token("RETURN_VALUE")]
)
def pp_tuple(self, tup):
"""Pretty print a tuple"""
last_line = self.f.getvalue().split("\n")[-1]
l = len(last_line) + 1
indent = " " * l
self.write("(")
sep = ""
for item in tup:
self.write(sep)
l += len(sep)
s = better_repr(item, self.version)
l += len(s)
self.write(s)
sep = ","
if l > LINE_LENGTH:
l = 0
sep += "\n" + indent
else:
sep += " "
pass
pass
if len(tup) == 1:
self.write(", ")
self.write(")")
# Python changes make function this much that we need at least 3 different routines,
# and probably more in the future.
def make_function(self, node, is_lambda, nested=1, code_node=None, annotate=None):
if self.version <= (2, 7):
make_function2(self, node, is_lambda, nested, code_node)
elif (3, 0) <= self.version <= (3, 5):
make_function3(self, node, is_lambda, nested, code_node)
elif self.version >= (3, 6):
make_function36(self, node, is_lambda, nested, code_node)
def print_super_classes(self, node):
if not (node == "tuple"):
return
n_subclasses = len(node[:-1])
if n_subclasses > 0 or self.version > (2, 4):
# Not an old-style pre-2.2 class
self.write("(")
line_separator = ", "
sep = ""
for elem in node[:-1]:
value = self.traverse(elem)
self.write(sep, value)
sep = line_separator
if n_subclasses > 0 or self.version > (2, 4):
# Not an old-style pre-2.2 class
self.write(")")
def print_super_classes3(self, node):
n = len(node) - 1
if node.kind != "expr":
if node == "kwarg":
self.template_engine(("(%[0]{attr}=%c)", 1), node)
return
kwargs = None
assert node[n].kind.startswith("CALL_FUNCTION")
if node[n].kind.startswith("CALL_FUNCTION_KW"):
if self.is_pypy:
# FIXME: this doesn't handle positional and keyword args
# properly. Need to do something more like that below
# in the non-PYPY 3.6 case.
self.template_engine(("(%[0]{attr}=%c)", 1), node[n - 1])
return
else:
kwargs = node[n - 1].attr
assert isinstance(kwargs, tuple)
i = n - (len(kwargs) + 1)
j = 1 + n - node[n].attr
else:
i = start = n - 2
for i in range(start, 0, -1):
if not node[i].kind in ["expr", "call", "LOAD_CLASSNAME"]:
break
pass
if i == start:
return
i += 2
line_separator = ", "
sep = ""
self.write("(")
if kwargs:
# Last arg is tuple of keyword values: omit
l = n - 1
else:
l = n
if kwargs:
# 3.6+ does this
while j < i:
self.write(sep)
value = self.traverse(node[j])
self.write("%s" % value)
sep = line_separator
j += 1
j = 0
while i < l:
self.write(sep)
value = self.traverse(node[i])
self.write("%s=%s" % (kwargs[j], value))
sep = line_separator
j += 1
i += 1
else:
while i < l:
value = self.traverse(node[i])
i += 1
self.write(sep, value)
sep = line_separator
pass
pass
else:
if node[0] == "LOAD_STR":
return
value = self.traverse(node[0])
self.write("(")
self.write(value)
pass
self.write(")")
def kv_map(self, kv_node, sep, line_number, indent):
first_time = True
for kv in kv_node:
assert kv in ("kv", "kv2", "kv3")
# kv ::= DUP_TOP expr ROT_TWO expr STORE_SUBSCR
# kv2 ::= DUP_TOP expr expr ROT_THREE STORE_SUBSCR
# kv3 ::= expr expr STORE_MAP
# FIXME: DRY this and the above
if kv == "kv":
self.write(sep)
name = self.traverse(kv[-2], indent="")
if first_time:
line_number = self.indent_if_source_nl(line_number, indent)
first_time = False
pass
line_number = self.line_number
self.write(name, ": ")
value = self.traverse(kv[1], indent=self.indent + (len(name) + 2) * " ")
elif kv == "kv2":
self.write(sep)
name = self.traverse(kv[1], indent="")
if first_time:
line_number = self.indent_if_source_nl(line_number, indent)
first_time = False
pass
line_number = self.line_number
self.write(name, ": ")
value = self.traverse(
kv[-3], indent=self.indent + (len(name) + 2) * " "
)
elif kv == "kv3":
self.write(sep)
name = self.traverse(kv[-2], indent="")
if first_time:
line_number = self.indent_if_source_nl(line_number, indent)
first_time = False
pass
line_number = self.line_number
self.write(name, ": ")
line_number = self.line_number
value = self.traverse(kv[0], indent=self.indent + (len(name) + 2) * " ")
pass
self.write(value)
sep = ", "
if line_number != self.line_number:
sep += "\n" + self.indent + " "
line_number = self.line_number
pass
pass
def template_engine(self, entry, startnode):
"""The format template interpetation engine. See the comment at the
beginning of this module for the how we interpret format
specifications such as %c, %C, and so on.
"""
# print("-----")
# print(startnode)
# print(entry[0])
# print('======')
fmt = entry[0]
arg = 1
i = 0
m = escape.search(fmt)
while m:
i = m.end()
self.write(m.group("prefix"))
typ = m.group("type") or "{"
node = startnode
if m.group("child"):
node = node[int(m.group("child"))]
if typ == "%":
self.write("%")
elif typ == "+":
self.line_number += 1
self.indent_more()
elif typ == "-":
self.line_number += 1
self.indent_less()
elif typ == "|":
self.line_number += 1
self.write(self.indent)
# Used mostly on the LHS of an assignment
# BUILD_TUPLE_n is pretty printed and may take care of other uses.
elif typ == ",":
if node.kind in ("unpack", "unpack_w_parens") and node[0].attr == 1:
self.write(",")
elif typ == "c":
index = entry[arg]
if isinstance(index, tuple):
if isinstance(index[1], str):
# if node[index[0]] != index[1]:
# from trepan.api import debug; debug()
assert node[index[0]] == index[1], (
"at %s[%d], expected '%s' node; got '%s'"
% (node.kind, arg, index[1], node[index[0]].kind,)
)
else:
assert node[index[0]] in index[1], (
"at %s[%d], expected to be in '%s' node; got '%s'"
% (node.kind, arg, index[1], node[index[0]].kind,)
)
index = index[0]
assert isinstance(index, int), (
"at %s[%d], %s should be int or tuple"
% (node.kind, arg, type(index),)
)
try:
node[index]
except IndexError:
raise RuntimeError(
f"""
Expanding '{node.kind}' in template '{entry}[{arg}]':
{index} is invalid; has only {len(node)} entries
"""
)
self.preorder(node[index])
arg += 1
elif typ == "p":
p = self.prec
# entry[arg]
tup = entry[arg]
assert isinstance(tup, tuple)
if len(tup) == 3:
(index, nonterm_name, self.prec) = tup
if isinstance(tup[1], str):
assert node[index] == nonterm_name, (
"at %s[%d], expected '%s' node; got '%s'"
% (node.kind, arg, nonterm_name, node[index].kind,)
)
else:
assert node[tup[0]] in tup[1], (
"at %s[%d], expected to be in '%s' node; got '%s'"
% (node.kind, arg, index[1], node[index[0]].kind,)
)
else:
assert len(tup) == 2
(index, self.prec) = entry[arg]
self.preorder(node[index])
self.prec = p
arg += 1
elif typ == "C":
low, high, sep = entry[arg]
remaining = len(node[low:high])
for subnode in node[low:high]:
self.preorder(subnode)
remaining -= 1
if remaining > 0:
self.write(sep)
pass
pass
arg += 1
elif typ == "D":
low, high, sep = entry[arg]
remaining = len(node[low:high])
for subnode in node[low:high]:
remaining -= 1
if len(subnode) > 0:
self.preorder(subnode)
if remaining > 0:
self.write(sep)
pass
pass
pass
arg += 1
elif typ == "x":
# This code is only used in fragments
assert isinstance(entry[arg], tuple)
arg += 1
elif typ == "P":
p = self.prec
low, high, sep, self.prec = entry[arg]
remaining = len(node[low:high])
# remaining = len(node[low:high])
for subnode in node[low:high]:
self.preorder(subnode)
remaining -= 1
if remaining > 0:
self.write(sep)
self.prec = p
arg += 1
elif typ == "{":
expr = m.group("expr")
# Line mapping stuff
if (
hasattr(node, "linestart")
and node.linestart
and hasattr(node, "current_line_number")
):
self.source_linemap[self.current_line_number] = node.linestart
if expr[0] == "%":
index = entry[arg]
self.template_engine((expr, index), node)
arg += 1
else:
d = node.__dict__
try:
self.write(eval(expr, d, d))
except:
raise
m = escape.search(fmt, i)
self.write(fmt[i:])
def default(self, node):
mapping = self._get_mapping(node)
table = mapping[0]
key = node
for i in mapping[1:]:
key = key[i]
pass
if key.kind in table:
self.template_engine(table[key.kind], node)
self.prune()
def customize(self, customize):
"""
Special handling for opcodes, such as those that take a variable number
of arguments -- we add a new entry for each in TABLE_R.
"""
for k, v in list(customize.items()):
if k in TABLE_R:
continue
op = k[: k.rfind("_")]
if k.startswith("CALL_METHOD"):
# This happens in PyPy and Python 3.7+
TABLE_R[k] = ("%c(%P)", (0, "expr"), (1, -1, ", ", 100))
elif self.version >= (3, 6) and k.startswith("CALL_FUNCTION_KW"):
TABLE_R[k] = ("%c(%P)", (0, "expr"), (1, -1, ", ", 100))
elif op == "CALL_FUNCTION":
TABLE_R[k] = (
"%c(%P)",
(0, "expr"),
(1, -1, ", ", PRECEDENCE["yield"] - 1),
)
elif op in (
"CALL_FUNCTION_VAR",
"CALL_FUNCTION_VAR_KW",
"CALL_FUNCTION_KW",
):
# FIXME: handle everything in customize.
# Right now, some of this is here, and some in that.
if v == 0:
str = "%c(%C" # '%C' is a dummy here ...
p2 = (0, 0, None) # .. because of the None in this
else:
str = "%c(%C, "
p2 = (1, -2, ", ")
if op == "CALL_FUNCTION_VAR":
# Python 3.5 only puts optional args (the VAR part)
# lowest down the stack
if self.version == (3, 5):
if str == "%c(%C, ":
entry = ("%c(*%C, %c)", 0, p2, -2)
elif str == "%c(%C":
entry = ("%c(*%C)", 0, (1, 100, ""))
elif self.version == (3, 4):
# CALL_FUNCTION_VAR's top element of the stack contains
# the variable argument list
if v == 0:
str = "%c(*%c)"
entry = (str, 0, -2)
else:
str = "%c(%C, *%c)"
entry = (str, 0, p2, -2)
else:
str += "*%c)"
entry = (str, 0, p2, -2)
elif op == "CALL_FUNCTION_KW":
str += "**%c)"
entry = (str, 0, p2, -2)
elif op == "CALL_FUNCTION_VAR_KW":
str += "*%c, **%c)"
# Python 3.5 only puts optional args (the VAR part)
# lowest down the stack
na = v & 0xFF # positional parameters
if self.version == (3, 5) and na == 0:
if p2[2]:
p2 = (2, -2, ", ")
entry = (str, 0, p2, 1, -2)
else:
if p2[2]:
p2 = (1, -3, ", ")
entry = (str, 0, p2, -3, -2)
pass
else:
assert False, "Unhandled CALL_FUNCTION %s" % op
TABLE_R[k] = entry
pass
# handled by n_dict:
# if op == 'BUILD_SLICE': TABLE_R[k] = ('%C' , (0,-1,':'))
# handled by n_list:
# if op == 'BUILD_LIST': TABLE_R[k] = ('[%C]' , (0,-1,', '))
# elif op == 'BUILD_TUPLE': TABLE_R[k] = ('(%C%,)', (0,-1,', '))
pass
return
# This code is only for Python 1.x - 2.1 ish!
def get_tuple_parameter(self, ast, name):
"""
If the name of the formal parameter starts with dot,
it's a tuple parameter, like this:
# def MyFunc(xx, (a,b,c), yy):
# print a, b*2, c*42
In byte-code, the whole tuple is assigned to parameter '.1' and
then the tuple gets unpacked to 'a', 'b' and 'c'.
Since identifiers starting with a dot are illegal in Python,
we can search for the byte-code equivalent to '(a,b,c) = .1'
"""
assert ast == "stmts"
for i in range(len(ast)):
# search for an assign-statement
if ast[i] == "sstmt":
node = ast[i][0]
else:
node = ast[i]
if node == "assign" and node[0] == ASSIGN_TUPLE_PARAM(name):
# okay, this assigns '.n' to something
del ast[i]
# walk lhs; this
# returns a tuple of identifiers as used
# within the function definition
assert node[1] == "store"
# if lhs is not a UNPACK_TUPLE (or equiv.),
# add parenteses to make this a tuple
# if node[1][0] not in ('unpack', 'unpack_list'):
result = self.traverse(node[1])
if not (result.startswith("(") and result.endswith(")")):
result = "(%s)" % result
return result
# return self.traverse(node[1])
raise Exception("Can't find tuple parameter " + name)
def build_class(self, code):
"""Dump class definition, doc string and class body."""
assert iscode(code)
self.classes.append(self.currentclass)
code = Code(code, self.scanner, self.currentclass)
indent = self.indent
# self.println(indent, '#flags:\t', int(code.co_flags))
ast = self.build_ast(code._tokens, code._customize, code)
# save memory by deleting no-longer-used structures
code._tokens = None
if ast[0] == "sstmt":
ast[0] = ast[0][0]
first_stmt = ast[0]
if ast[0] == "docstring":
self.println(self.traverse(ast[0]))
del ast[0]
first_stmt = ast[0]
if (3, 0) <= self.version <= (3, 3):
try:
if first_stmt == "store_locals":
if self.hide_internal:
del ast[0]
if ast[0] == "sstmt":
ast[0] = ast[0][0]
first_stmt = ast[0]
except:
pass
try:
if first_stmt == NAME_MODULE:
if self.hide_internal:
del ast[0]
first_stmt = ast[0]
pass
except:
pass
have_qualname = False
if len(ast):
if ast[0] == "sstmt":
ast[0] = ast[0][0]
first_stmt = ast[0]
if self.version < (3, 0):
# Should we ditch this in favor of the "else" case?
qualname = ".".join(self.classes)
QUAL_NAME = SyntaxTree(
"assign",
[
SyntaxTree("expr", [Token("LOAD_CONST", pattr=qualname)]),
SyntaxTree(
"store", [Token("STORE_NAME", pattr="__qualname__")]
),
],
)
# FIXME: is this right now that we've redone the grammar?
have_qualname = ast[0] == QUAL_NAME
else:
# Python 3.4+ has constants like 'cmp_to_key.<locals>.K'
# which are not simple classes like the < 3 case.
try:
if (
first_stmt == "assign"
and first_stmt[0][0] == "LOAD_STR"
and first_stmt[1] == "store"
and first_stmt[1][0] == Token("STORE_NAME", pattr="__qualname__")
):
have_qualname = True
except:
pass
if have_qualname:
if self.hide_internal:
del ast[0]
pass
# if docstring exists, dump it
if code.co_consts and code.co_consts[0] is not None and len(ast) > 0:
do_doc = False
if is_docstring(ast[0], self.version, code.co_consts):
i = 0
do_doc = True
elif len(ast) > 1 and is_docstring(ast[1], self.version, code.co_consts):
i = 1
do_doc = True
if do_doc and self.hide_internal:
try:
# FIXME: Is there an extra [0]?
docstring = ast[i][0][0][0][0].pattr
except:
docstring = code.co_consts[0]
if print_docstring(self, indent, docstring):
self.println()
del ast[i]
# The function defining a class returns locals() in Python somewhere less than
# 3.7.
#
# We don't want this to show up in the source, so remove the node.
if len(ast):
if ast == "stmts" and ast[-1] == "sstmt":
return_locals_parent = ast[-1]
parent_index = 0
else:
return_locals_parent = ast
parent_index = -1
return_locals = return_locals_parent[parent_index]
if return_locals == RETURN_LOCALS:
if self.hide_internal:
del return_locals_parent[parent_index]
pass
pass
# else:
# print stmt[-1]
globals, nonlocals = find_globals_and_nonlocals(
ast, set(), set(), code, self.version
)
# Add "global" declaration statements at the top
# of the function
for g in sorted(globals):
self.println(indent, "global ", g)
for nl in sorted(nonlocals):
self.println(indent, "nonlocal ", nl)
old_name = self.name
self.gen_source(ast, code.co_name, code._customize)
self.name = old_name
# save memory by deleting no-longer-used structures
code._tokens = None
code._customize = None
self.classes.pop(-1)
def gen_source(
self,
ast,
name,
customize,
is_lambda=False,
returnNone=False,
debug_opts=DEFAULT_DEBUG_OPTS,
):
"""convert parse tree to Python source code"""
rn = self.return_none
self.return_none = returnNone
old_name = self.name
self.name = name
self.debug_opts = debug_opts
# if code would be empty, append 'pass'
if len(ast) == 0:
self.println(self.indent, "pass")
else:
self.customize(customize)
self.text = self.traverse(ast, is_lambda=is_lambda)
# In a formatted string using "lambda', we should not add "\n".
# For example in:
# f'{(lambda x:x)("8")!r}'
# Adding a "\n" after "lambda x: x" will give an error message:
# SyntaxError: f-string expression part cannot include a backslash
# So avoid that.
printfn = (
self.write if self.in_format_string and is_lambda else self.println
)
printfn(self.text)
self.name = old_name
self.return_none = rn
def build_ast(
self,
tokens,
customize,
code,
is_lambda=False,
noneInNames=False,
is_top_level_module=False,
):
# FIXME: DRY with fragments.py
# assert isinstance(tokens[0], Token)
if is_lambda:
for t in tokens:
if t.kind == "RETURN_END_IF":
t.kind = "RETURN_END_IF_LAMBDA"
elif t.kind == "RETURN_VALUE":
t.kind = "RETURN_VALUE_LAMBDA"
tokens.append(Token("LAMBDA_MARKER"))
try:
# FIXME: have p.insts update in a better way
# modularity is broken here
p_insts = self.p.insts
self.p.insts = self.scanner.insts
self.p.offset2inst_index = self.scanner.offset2inst_index
ast = python_parser.parse(self.p, tokens, customize, code)
self.customize(customize)
self.p.insts = p_insts
except (python_parser.ParserError, AssertionError) as e:
raise ParserError(e, tokens, self.p.debug["reduce"])
transform_tree = self.treeTransform.transform(ast, code)
self.maybe_show_tree(ast, phase="after")
del ast # Save memory
return transform_tree
# The bytecode for the end of the main routine has a
# "return None". However you can't issue a "return" statement in
# main. So as the old cigarette slogan goes: I'd rather switch (the token stream)
# than fight (with the grammar to not emit "return None").
if self.hide_internal:
if len(tokens) >= 2 and not noneInNames:
if tokens[-1].kind in ("RETURN_VALUE", "RETURN_VALUE_LAMBDA"):
# Python 3.4's classes can add a "return None" which is
# invalid syntax.
if tokens[-2].kind == "LOAD_CONST":
if is_top_level_module or tokens[-2].pattr is None:
del tokens[-2:]
else:
tokens.append(Token("RETURN_LAST"))
else:
tokens.append(Token("RETURN_LAST"))
if len(tokens) == 0:
return PASS
# Build a parse tree from a tokenized and massaged disassembly.
try:
# FIXME: have p.insts update in a better way
# modularity is broken here
p_insts = self.p.insts
self.p.insts = self.scanner.insts
self.p.offset2inst_index = self.scanner.offset2inst_index
self.p.opc = self.scanner.opc
ast = python_parser.parse(self.p, tokens, customize, code)
self.p.insts = p_insts
except (python_parser.ParserError, AssertionError) as e:
raise ParserError(e, tokens, self.p.debug["reduce"])
checker(ast, False, self.ast_errors)
self.customize(customize)
transform_tree = self.treeTransform.transform(ast, code)
self.maybe_show_tree(ast, phase="before")
del ast # Save memory
return transform_tree
@classmethod
def _get_mapping(cls, node):
return MAP.get(node, MAP_DIRECT)
def code_deparse(
co,
out=sys.stdout,
version=None,
debug_opts=DEFAULT_DEBUG_OPTS,
code_objects={},
compile_mode="exec",
is_pypy=IS_PYPY,
walker=SourceWalker,
):
"""
ingests and deparses a given code block 'co'. If version is None,
we will use the current Python interpreter version.
"""
assert iscode(co)
if version is None:
version = PYTHON_VERSION_TRIPLE
# store final output stream for case of error
scanner = get_scanner(version, is_pypy=is_pypy, show_asm=debug_opts["asm"])
tokens, customize = scanner.ingest(
co, code_objects=code_objects, show_asm=debug_opts["asm"]
)
debug_parser = debug_opts.get("grammar", dict(PARSER_DEFAULT_DEBUG))
# Build Syntax Tree from disassembly.
linestarts = dict(scanner.opc.findlinestarts(co))
deparsed = walker(
version,
out,
scanner,
showast=debug_opts.get("tree", TREE_DEFAULT_DEBUG),
debug_parser=debug_parser,
compile_mode=compile_mode,
is_pypy=is_pypy,
linestarts=linestarts,
)
is_top_level_module = co.co_name == "<module>"
if compile_mode == "eval":
deparsed.hide_internal = False
deparsed.compile_mode = compile_mode
deparsed.ast = deparsed.build_ast(
tokens,
customize,
co,
is_lambda=(compile_mode == "lambda"),
is_top_level_module=is_top_level_module,
)
#### XXX workaround for profiling
if deparsed.ast is None:
return None
# FIXME use a lookup table here.
if compile_mode == "lambda":
expected_start = "lambda_start"
elif compile_mode == "eval":
expected_start = "expr_start"
elif compile_mode == "expr":
expected_start = "expr_start"
elif compile_mode == "exec":
expected_start = "stmts"
elif compile_mode == "single":
# expected_start = "single_start"
expected_start = None
else:
expected_start = None
if expected_start:
assert (
deparsed.ast == expected_start
), f"Should have parsed grammar start to '{expected_start}'; got: {deparsed.ast.kind}"
# save memory
del tokens
deparsed.mod_globs, nonlocals = find_globals_and_nonlocals(
deparsed.ast, set(), set(), co, version
)
assert not nonlocals
if version >= (3, 0):
load_op = "LOAD_STR"
else:
load_op = "LOAD_CONST"
# convert leading '__doc__ = "..." into doc string
try:
stmts = deparsed.ast
first_stmt = stmts[0][0]
if version >= 3.6:
if first_stmt[0] == "SETUP_ANNOTATIONS":
del stmts[0]
assert stmts[0] == "sstmt"
# Nuke sstmt
first_stmt = stmts[0][0]
pass
pass
if first_stmt == ASSIGN_DOC_STRING(co.co_consts[0], load_op):
print_docstring(deparsed, "", co.co_consts[0])
del stmts[0]
if stmts[-1] == RETURN_NONE:
stmts.pop() # remove last node
# todo: if empty, add 'pass'
except:
pass
deparsed.FUTURE_UNICODE_LITERALS = (
COMPILER_FLAG_BIT["FUTURE_UNICODE_LITERALS"] & co.co_flags != 0
)
# What we've been waiting for: Generate source from Syntax Tree!
deparsed.gen_source(
deparsed.ast,
name=co.co_name,
customize=customize,
is_lambda=compile_mode == "lambda",
debug_opts=debug_opts,
)
for g in sorted(deparsed.mod_globs):
deparsed.write("# global %s ## Warning: Unused global\n" % g)
if deparsed.ast_errors:
deparsed.write("# NOTE: have internal decompilation grammar errors.\n")
deparsed.write("# Use -T option to show full context.")
for err in deparsed.ast_errors:
deparsed.write(err)
raise SourceWalkerError("Deparsing hit an internal grammar-rule bug")
if deparsed.ERROR:
raise SourceWalkerError("Deparsing stopped due to parse error")
return deparsed
def deparse_code2str(
code,
out=sys.stdout,
version=None,
debug_opts=DEFAULT_DEBUG_OPTS,
code_objects={},
compile_mode="exec",
is_pypy=IS_PYPY,
walker=SourceWalker,
):
"""Return the deparsed text for a Python code object. `out` is where any intermediate
output for assembly or tree output will be sent.
"""
return code_deparse(
code,
out,
version,
debug_opts,
code_objects=code_objects,
compile_mode=compile_mode,
is_pypy=is_pypy,
walker=walker,
).text
if __name__ == "__main__":
def deparse_test(co):
"This is a docstring"
s = deparse_code2str(co)
# s = deparse_code2str(co, debug_opts={"asm": "after", "tree": {'before': False, 'after': False}})
print(s)
return
deparse_test(deparse_test.__code__)
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