# Copyright (c) 2018 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
# 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 .
"""Isolate Python version-specific semantic actions here.
"""
from uncompyle6.semantics.consts import (
PRECEDENCE, INDENT_PER_LEVEL, TABLE_R, TABLE_DIRECT)
from uncompyle6.semantics.make_function import (
make_function3_annotate,
)
from xdis.util import COMPILER_FLAG_BIT
from xdis.code import iscode
from uncompyle6.parsers.astnode import AST
from uncompyle6.scanners.tok import Token
from uncompyle6.semantics.helper import flatten_list
from spark_parser.ast import GenericASTTraversalPruningException
def customize_for_version(self, is_pypy, version):
if is_pypy:
########################
# PyPy changes
#######################
TABLE_DIRECT.update({
'assert_pypy': ( '%|assert %c\n' , 1 ),
'assert2_pypy': ( '%|assert %c, %c\n' , 1, 4 ),
'try_except_pypy': ( '%|try:\n%+%c%-%c\n\n', 1, 2 ),
'tryfinallystmt_pypy': ( '%|try:\n%+%c%-%|finally:\n%+%c%-\n\n', 1, 3 ),
'assign3_pypy': ( '%|%c, %c, %c = %c, %c, %c\n', 5, 4, 3, 0, 1, 2 ),
'assign2_pypy': ( '%|%c, %c = %c, %c\n', 3, 2, 0, 1),
})
else:
########################
# Without PyPy
#######################
TABLE_DIRECT.update({
'assert': ( '%|assert %c\n' , 0 ),
'assert2': ( '%|assert %c, %c\n' , 0, 3 ),
'try_except': ( '%|try:\n%+%c%-%c\n\n', 1, 3 ),
'assign2': ( '%|%c, %c = %c, %c\n', 3, 4, 0, 1 ),
'assign3': ( '%|%c, %c, %c = %c, %c, %c\n', 5, 6, 7, 0, 1, 2 ),
})
if version < 3.0:
TABLE_R.update({
'STORE_SLICE+0': ( '%c[:]', 0 ),
'STORE_SLICE+1': ( '%c[%p:]', 0, (1, -1) ),
'STORE_SLICE+2': ( '%c[:%p]', 0, (1, -1) ),
'STORE_SLICE+3': ( '%c[%p:%p]', 0, (1, -1), (2, -1) ),
'DELETE_SLICE+0': ( '%|del %c[:]\n', 0 ),
'DELETE_SLICE+1': ( '%|del %c[%c:]\n', 0, 1 ),
'DELETE_SLICE+2': ( '%|del %c[:%c]\n', 0, 1 ),
'DELETE_SLICE+3': ( '%|del %c[%c:%c]\n', 0, 1, 2 ),
})
TABLE_DIRECT.update({
'raise_stmt2': ( '%|raise %c, %c\n', 0, 1),
})
# exec as a built-in statement is only in Python 2.x
def n_exec_stmt(self, node):
"""
exec_stmt ::= expr exprlist DUP_TOP EXEC_STMT
exec_stmt ::= expr exprlist EXEC_STMT
"""
self.write(self.indent, 'exec ')
self.preorder(node[0])
if not node[1][0].isNone():
sep = ' in '
for subnode in node[1]:
self.write(sep); sep = ", "
self.preorder(subnode)
self.println()
self.prune() # stop recursing
self.n_exec_smt = n_exec_stmt
else:
TABLE_DIRECT.update({
# Gotta love Python for its futzing around with syntax like this
'raise_stmt2': ( '%|raise %c from %c\n', 0, 1),
})
if version >= 3.2:
TABLE_DIRECT.update({
'del_deref_stmt': ( '%|del %c\n', 0),
'DELETE_DEREF': ( '%{pattr}', 0 ),
})
if version <= 2.4:
TABLE_DIRECT.update({
'importmultiple': ( '%|import %c%c\n', 2, 3),
'import_cont' : ( ', %c', 2),
'tryfinallystmt': ( '%|try:\n%+%c%-%|finally:\n%+%c%-',
(1, 'suite_stmts_opt') ,
(5, 'suite_stmts_opt') )
})
if version == 2.3:
TABLE_DIRECT.update({
'if1_stmt': ( '%|if 1\n%+%c%-', 5 )
})
global NAME_MODULE
NAME_MODULE = AST('stmt',
[ AST('assign',
[ AST('expr',
[Token('LOAD_GLOBAL', pattr='__name__',
offset=0, has_arg=True)]),
AST('store',
[ Token('STORE_NAME', pattr='__module__',
offset=3, has_arg=True)])
])])
pass
if version <= 2.3:
if version <= 2.1:
TABLE_DIRECT.update({
'importmultiple': ( '%c', 2 ),
# FIXME: not quite right. We have indiividual imports
# when there is in fact one: "import a, b, ..."
'imports_cont': ( '%C%,', (1, 100, '\n') ),
})
pass
pass
pass
elif version >= 2.5:
########################
# Import style for 2.5+
########################
TABLE_DIRECT.update({
'importmultiple': ( '%|import %c%c\n', 2, 3 ),
'import_cont' : ( ', %c', 2 ),
# With/as is allowed as "from future" thing in 2.5
# Note: It is safe to put the variables after "as" in parenthesis,
# and sometimes it is needed.
'withstmt': ( '%|with %c:\n%+%c%-', 0, 3),
'withasstmt': ( '%|with %c as (%c):\n%+%c%-', 0, 2, 3),
})
# In 2.5+ "except" handlers and the "finally" can appear in one
# "try" statement. So the below has the effect of combining the
# "tryfinally" with statement with the "try_except" statement
def tryfinallystmt(node):
if len(node[1][0]) == 1 and node[1][0][0] == 'stmt':
if node[1][0][0][0] == 'try_except':
node[1][0][0][0].kind = 'tf_try_except'
if node[1][0][0][0] == 'tryelsestmt':
node[1][0][0][0].kind = 'tf_tryelsestmt'
self.default(node)
self.n_tryfinallystmt = tryfinallystmt
########################################
# Python 2.6+
# except as
# vs. older:
# except ,
#
# For 2.6 we use the older syntax which
# matches how we parse this in bytecode
########################################
if version > 2.6:
TABLE_DIRECT.update({
'except_cond2': ( '%|except %c as %c:\n', 1, 5 ),
})
else:
TABLE_DIRECT.update({
'except_cond3': ( '%|except %c, %c:\n', 1, 6 ),
'testtrue_then': ( 'not %p', (0, 22) ),
})
if 2.4 <= version <= 2.6:
TABLE_DIRECT.update({
'comp_for': ( ' for %c in %c', 3, 1 ),
})
else:
TABLE_DIRECT.update({
'comp_for': ( ' for %c in %c%c', 2, 0, 3 ),
})
if version >= 3.0:
TABLE_DIRECT.update({
'function_def_annotate': ( '\n\n%|def %c%c\n', -1, 0),
'store_locals': ( '%|# inspect.currentframe().f_locals = __locals__\n', ),
})
def n_mkfunc_annotate(node):
if self.version >= 3.3 or node[-2] == 'kwargs':
# LOAD_CONST code object ..
# LOAD_CONST 'x0' if >= 3.3
# EXTENDED_ARG
# MAKE_FUNCTION ..
code = node[-4]
elif node[-3] == 'expr':
code = node[-3][0]
else:
# LOAD_CONST code object ..
# MAKE_FUNCTION ..
code = node[-3]
self.indent_more()
for annotate_last in range(len(node)-1, -1, -1):
if node[annotate_last] == 'annotate_tuple':
break
# FIXME: the real situation is that when derived from
# function_def_annotate we the name has been filled in.
# But when derived from funcdefdeco it hasn't Would like a better
# way to distinquish.
if self.f.getvalue()[-4:] == 'def ':
self.write(code.attr.co_name)
# FIXME: handle and pass full annotate args
make_function3_annotate(self, node, is_lambda=False,
codeNode=code, annotate_last=annotate_last)
if len(self.param_stack) > 1:
self.write('\n\n')
else:
self.write('\n\n\n')
self.indent_less()
self.prune() # stop recursing
self.n_mkfunc_annotate = n_mkfunc_annotate
if version >= 3.4:
########################
# Python 3.4+ Additions
#######################
TABLE_DIRECT.update({
'LOAD_CLASSDEREF': ( '%{pattr}', ),
})
if version == 3.4:
def n_call(node):
mapping = self._get_mapping(node)
key = node
for i in mapping[1:]:
key = key[i]
pass
if key.kind.startswith('CALL_FUNCTION_VAR_KW'):
# We may want to fill this in...
# But it is distinct from CALL_FUNCTION_VAR below
pass
elif key.kind.startswith('CALL_FUNCTION_VAR'):
# CALL_FUNCTION_VAR's top element of the stack contains
# the variable argument list, then comes
# annotation args, then keyword args.
# In the most least-top-most stack entry, but position 1
# in node order, the positional args.
argc = node[-1].attr
nargs = argc & 0xFF
kwargs = (argc >> 8) & 0xFF
# FIXME: handle annotation args
if kwargs != 0:
# kwargs == 0 is handled by the table entry
# Should probably handle it here though.
if nargs == 0:
template = ('%c(*%c, %C)',
0, -2, (1, kwargs+1, ', '))
else:
template = ('%c(%C, *%c, %C)',
0, (1, nargs+1, ', '),
-2, (-2-kwargs, -2, ', '))
self.template_engine(template, node)
self.prune()
self.default(node)
self.n_call = n_call
########################
# Python 3.5+ Additions
#######################
if version >= 3.5:
TABLE_DIRECT.update({
'await_expr': ( 'await %c', 0),
'await_stmt': ( '%|%c\n', 0),
'async_for_stmt': (
'%|async for %c in %c:\n%+%c%-\n\n', 9, 1, 25 ),
'async_forelse_stmt': (
'%|async for %c in %c:\n%+%c%-%|else:\n%+%c%-\n\n', 9, 1, 25, 28 ),
'async_with_stmt': (
'%|async with %c:\n%+%c%-', 0, 7),
'async_with_as_stmt': (
'%|async with %c as %c:\n%+%c%-', 0, 6, 7),
'unmap_dict': ( '{**%C}', (0, -1, ', **') ),
# 'unmapexpr': ( '{**%c}', 0), # done by n_unmapexpr
})
def async_call(node):
self.f.write('async ')
node.kind == 'call'
p = self.prec
self.prec = 80
self.template_engine(('%c(%P)', 0, (1, -4, ', ',
100)), node)
self.prec = p
node.kind == 'async_call'
self.prune()
self.n_async_call = async_call
self.n_build_list_unpack = self.n_list
if version == 3.5:
def n_call(node):
mapping = self._get_mapping(node)
table = mapping[0]
key = node
for i in mapping[1:]:
key = key[i]
pass
if key.kind.startswith('CALL_FUNCTION_VAR_KW'):
# Python 3.5 changes the stack position of
# *args: kwargs come after *args whereas
# in earlier Pythons, *args is at the end
# which simplifies things from our
# perspective. Python 3.6+ replaces
# CALL_FUNCTION_VAR_KW with
# CALL_FUNCTION_EX We will just swap the
# order to make it look like earlier
# Python 3.
entry = table[key.kind]
kwarg_pos = entry[2][1]
args_pos = kwarg_pos - 1
# Put last node[args_pos] after subsequent kwargs
while node[kwarg_pos] == 'kwarg' and kwarg_pos < len(node):
# swap node[args_pos] with node[kwargs_pos]
node[kwarg_pos], node[args_pos] = node[args_pos], node[kwarg_pos]
args_pos = kwarg_pos
kwarg_pos += 1
elif key.kind.startswith('CALL_FUNCTION_VAR'):
# CALL_FUNCTION_VAR's top element of the stack contains
# the variable argument list, then comes
# annotation args, then keyword args.
# In the most least-top-most stack entry, but position 1
# in node order, the positional args.
argc = node[-1].attr
nargs = argc & 0xFF
kwargs = (argc >> 8) & 0xFF
# FIXME: handle annotation args
if nargs > 0:
template = ('%c(%C, ', 0, (1, nargs+1, ', '))
else:
template = ('%c(', 0)
self.template_engine(template, node)
args_node = node[-2]
if args_node in ('pos_arg', 'expr'):
args_node = args_node[0]
if args_node == 'build_list_unpack':
template = ('*%P)', (0, len(args_node)-1, ', *', 100))
self.template_engine(template, args_node)
else:
if len(node) - nargs > 3:
template = ('*%c, %C)', 1, (nargs+kwargs+1, -1, ', '))
else:
template = ('*%c)', 1)
self.template_engine(template, node)
self.prune()
self.default(node)
self.n_call = n_call
def n_function_def(node):
if self.version == 3.6:
code_node = node[0][0]
else:
code_node = node[0][1]
is_code = hasattr(code_node, 'attr') and iscode(code_node.attr)
if (is_code and
(code_node.attr.co_flags & COMPILER_FLAG_BIT['COROUTINE'])):
self.template_engine(('\n\n%|async def %c\n',
-2), node)
else:
self.template_engine(('\n\n%|def %c\n', -2),
node)
self.prune()
self.n_function_def = n_function_def
def unmapexpr(node):
last_n = node[0][-1]
for n in node[0]:
self.preorder(n)
if n != last_n:
self.f.write(', **')
pass
pass
self.prune()
pass
self.n_unmapexpr = unmapexpr
if version >= 3.6:
########################
# Python 3.6+ Additions
#######################
# Value 100 is important; it is exactly
# module/function precidence.
PRECEDENCE['call_kw'] = 100
PRECEDENCE['call_kw36'] = 100
PRECEDENCE['call_ex'] = 100
TABLE_DIRECT.update({
'tryfinally36': ( '%|try:\n%+%c%-%|finally:\n%+%c%-\n\n',
(1, 'returns'), 3 ),
'fstring_expr': ( "{%c%{conversion}}", 0),
# FIXME: the below assumes the format strings
# don't have ''' in them. Fix this properly
'fstring_single': ( "f'''{%c%{conversion}}'''", 0),
'fstring_multi': ( "f'''%c'''", 0),
'func_args36': ( "%c(**", 0),
'try_except36': ( '%|try:\n%+%c%-%c\n\n', 1, 2 ),
'except_return': ( '%|except:\n%+%c%-', 3 ),
'unpack_list': ( '*%c', (0, 'list') ),
'call_ex' : (
'%c(%p)',
(0, 'expr'), (1, 100)),
'call_ex_kw' : (
'%c(%p)',
(0, 'expr'), (2, 100)),
})
TABLE_R.update({
'CALL_FUNCTION_EX': ('%c(*%P)', 0, (1, 2, ', ', 100)),
# Not quite right
'CALL_FUNCTION_EX_KW': ('%c(**%C)', 0, (2, 3, ',')),
})
def build_unpack_tuple_with_call(node):
if node[0] == 'expr':
tup = node[0][0]
else:
tup = node[0]
pass
assert tup == 'tuple'
self.call36_tuple(tup)
buwc = node[-1]
assert buwc.kind.startswith('BUILD_TUPLE_UNPACK_WITH_CALL')
for n in node[1:-1]:
self.f.write(', *')
self.preorder(n)
pass
self.prune()
return
self.n_build_tuple_unpack_with_call = build_unpack_tuple_with_call
def build_unpack_map_with_call(node):
n = node[0]
if n == 'expr':
n = n[0]
if n == 'dict':
self.call36_dict(n)
first = 1
sep = ', **'
else:
first = 0
sep = '**'
for n in node[first:-1]:
self.f.write(sep)
self.preorder(n)
sep = ', **'
pass
self.prune()
return
self.n_build_map_unpack_with_call = build_unpack_map_with_call
def call_ex_kw2(node):
"""Handle CALL_FUNCTION_EX 2 (have KW) but with
BUILD_{MAP,TUPLE}_UNPACK_WITH_CALL"""
# This is weird shit. Thanks Python!
self.preorder(node[0])
self.write('(')
assert node[1] == 'build_tuple_unpack_with_call'
btuwc = node[1]
tup = btuwc[0]
if tup == 'expr':
tup = tup[0]
assert tup == 'tuple'
self.call36_tuple(tup)
assert node[2] == 'build_map_unpack_with_call'
self.write(', ')
d = node[2][0]
if d == 'expr':
d = d[0]
assert d == 'dict'
self.call36_dict(d)
args = btuwc[1]
self.write(', *')
self.preorder(args)
self.write(', **')
star_star_args = node[2][1]
if star_star_args == 'expr':
star_star_args = star_star_args[0]
self.preorder(star_star_args)
self.write(')')
self.prune()
self.n_call_ex_kw2 = call_ex_kw2
def call_ex_kw3(node):
"""Handle CALL_FUNCTION_EX 1 (have KW) but without
BUILD_MAP_UNPACK_WITH_CALL"""
self.preorder(node[0])
self.write('(')
args = node[1][0]
if args == 'expr':
args = args[0]
if args == 'tuple':
if self.call36_tuple(args) > 0:
self.write(', ')
pass
pass
self.write('*')
self.preorder(node[1][1])
self.write(', ')
kwargs = node[2]
if kwargs == 'expr':
kwargs = kwargs[0]
if kwargs == 'dict':
self.call36_dict(kwargs)
else:
self.write('**')
self.preorder(kwargs)
self.write(')')
self.prune()
self.n_call_ex_kw3 = call_ex_kw3
def call_ex_kw4(node):
"""Handle CALL_FUNCTION_EX {1 or 2} but without
BUILD_{MAP,TUPLE}_UNPACK_WITH_CALL"""
self.preorder(node[0])
self.write('(')
args = node[1][0]
if args == 'tuple':
if self.call36_tuple(args) > 0:
self.write(', ')
pass
pass
else:
self.write('*')
self.preorder(args)
self.write(', ')
pass
kwargs = node[2]
if kwargs == 'expr':
kwargs = kwargs[0]
call_function_ex = node[-1]
assert call_function_ex == 'CALL_FUNCTION_EX_KW'
# FIXME: decide if the below test be on kwargs == 'dict'
if (call_function_ex.attr & 1 and
(not isinstance(kwargs, Token) and kwargs != 'attribute')):
self.call36_dict(kwargs)
else:
self.write('**')
self.preorder(kwargs)
self.write(')')
self.prune()
self.n_call_ex_kw4 = call_ex_kw4
def call36_tuple(node):
"""
A tuple used in a call, these are like normal tuples but they
don't have the enclosing parenthesis.
"""
assert node == 'tuple'
# Note: don't iterate over last element which is a
# BUILD_TUPLE...
flat_elems = flatten_list(node[:-1])
self.indent_more(INDENT_PER_LEVEL)
sep = ''
for elem in flat_elems:
if elem in ('ROT_THREE', 'EXTENDED_ARG'):
continue
assert elem == 'expr'
line_number = self.line_number
value = self.traverse(elem)
if line_number != self.line_number:
sep += '\n' + self.indent + INDENT_PER_LEVEL[:-1]
self.write(sep, value)
sep = ', '
self.indent_less(INDENT_PER_LEVEL)
return len(flat_elems)
self.call36_tuple = call36_tuple
def call36_dict(node):
"""
A dict used in a call_ex_kw2, which are a dictionary items expressed
in a call. This should format to:
a=1, b=2
In other words, no braces, no quotes around keys and ":" becomes
"=".
We will source-code use line breaks to guide us when to break.
"""
p = self.prec
self.prec = 100
self.indent_more(INDENT_PER_LEVEL)
sep = INDENT_PER_LEVEL[:-1]
line_number = self.line_number
if node[0].kind.startswith('kvlist'):
# Python 3.5+ style key/value list in dict
kv_node = node[0]
l = list(kv_node)
i = 0
length = len(l)
# FIXME: Parser-speed improved grammars will have BUILD_MAP
# at the end. So in the future when everything is
# complete, we can do an "assert" instead of "if".
if kv_node[-1].kind.startswith("BUILD_MAP"):
length -= 1
# Respect line breaks from source
while i < length:
self.write(sep)
name = self.traverse(l[i], indent='')
# Strip off beginning and trailing quotes in name
name = name[1:-1]
if i > 0:
line_number = self.indent_if_source_nl(line_number,
self.indent + INDENT_PER_LEVEL[:-1])
line_number = self.line_number
self.write(name, '=')
value = self.traverse(l[i+1], indent=self.indent+(len(name)+2)*' ')
self.write(value)
sep = ", "
if line_number != self.line_number:
sep += "\n" + self.indent + INDENT_PER_LEVEL[:-1]
line_number = self.line_number
i += 2
pass
elif node[-1].kind.startswith('BUILD_CONST_KEY_MAP'):
keys_node = node[-2]
keys = keys_node.attr
# from trepan.api import debug; debug()
assert keys_node == 'LOAD_CONST' and isinstance(keys, tuple)
for i in range(node[-1].attr):
self.write(sep)
self.write(keys[i], '=')
value = self.traverse(node[i], indent='')
self.write(value)
sep = ", "
if line_number != self.line_number:
sep += "\n" + self.indent + INDENT_PER_LEVEL[:-1]
line_number = self.line_number
pass
pass
else:
self.write("**")
try:
self.default(node)
except GenericASTTraversalPruningException:
pass
self.prec = p
self.indent_less(INDENT_PER_LEVEL)
return
self.call36_dict = call36_dict
FSTRING_CONVERSION_MAP = {1: '!s', 2: '!r', 3: '!a'}
def n_except_suite_finalize(node):
if node[1] == 'returns' and self.hide_internal:
# Process node[1] only.
# The code after "returns", e.g. node[3], is dead code.
# Adding it is wrong as it dedents and another
# exception handler "except_stmt" afterwards.
# Note it is also possible that the grammar is wrong here.
# and this should not be "except_stmt".
self.indent_more()
self.preorder(node[1])
self.indent_less()
else:
self.default(node)
self.prune()
self.n_except_suite_finalize = n_except_suite_finalize
def n_formatted_value(node):
if node[0] == 'LOAD_CONST':
self.write(node[0].attr)
self.prune()
else:
self.default(node)
self.n_formatted_value = n_formatted_value
def f_conversion(node):
node.conversion = FSTRING_CONVERSION_MAP.get(node.data[1].attr, '')
def fstring_expr(node):
f_conversion(node)
self.default(node)
self.n_fstring_expr = fstring_expr
def fstring_single(node):
f_conversion(node)
self.default(node)
self.n_fstring_single = fstring_single
# def kwargs_only_36(node):
# keys = node[-1].attr
# num_kwargs = len(keys)
# values = node[:num_kwargs]
# for i, (key, value) in enumerate(zip(keys, values)):
# self.write(key + '=')
# self.preorder(value)
# if i < num_kwargs:
# self.write(',')
# self.prune()
# return
# self.n_kwargs_only_36 = kwargs_only_36
def n_call_kw36(node):
self.template_engine(("%c(", 0), node)
keys = node[-2].attr
num_kwargs = len(keys)
num_posargs = len(node) - (num_kwargs + 2)
n = len(node)
assert n >= len(keys)+1, \
'not enough parameters keyword-tuple values'
sep = ''
line_number = self.line_number
for i in range(1, num_posargs):
self.write(sep)
self.preorder(node[i])
if line_number != self.line_number:
sep = ",\n" + self.indent + " "
else:
sep = ", "
line_number = self.line_number
i = num_posargs
j = 0
# FIXME: adjust output for line breaks?
while i < n-2:
self.write(sep)
self.write(keys[j] + '=')
self.preorder(node[i])
if line_number != self.line_number:
sep = ",\n" + self.indent + " "
else:
sep = ", "
i += 1
j += 1
self.write(')')
self.prune()
return
self.n_call_kw36 = n_call_kw36
def starred(node):
l = len(node)
assert l > 0
pos_args = node[0]
if pos_args == 'expr':
pos_args = pos_args[0]
if pos_args == 'tuple':
build_tuple = pos_args[0]
if build_tuple.kind.startswith('BUILD_TUPLE'):
tuple_len = 0
else:
tuple_len = len(node) - 1
star_start = 1
template = '%C', (0, -1, ', ')
self.template_engine(template, pos_args)
if tuple_len == 0:
self.write("*()")
# That's it
self.prune()
self.write(', ')
else:
star_start = 0
if l > 1:
template = ( '*%C', (star_start, -1, ', *') )
else:
template = ( '*%c', (star_start, 'expr') )
self.template_engine(template, node)
self.prune()
self.n_starred = starred
def return_closure(node):
# Nothing should be output here
self.prune()
return
self.n_return_closure = return_closure
pass # version >= 3.6
pass # version >= 3.4
pass # version >= 3.0
return