python-uncompyle6/uncompyle6/parsers/parse24.py
2018-08-12 02:24:13 -04:00

109 lines
4.2 KiB
Python

# Copyright (c) 2016-2018 Rocky Bernstein
"""
spark grammar differences over Python2.5 for Python 2.4.
"""
from uncompyle6.parser import PythonParserSingle
from spark_parser import DEFAULT_DEBUG as PARSER_DEFAULT_DEBUG
from uncompyle6.parsers.parse25 import Python25Parser
class Python24Parser(Python25Parser):
def __init__(self, debug_parser=PARSER_DEFAULT_DEBUG):
super(Python24Parser, self).__init__(debug_parser)
self.customized = {}
def p_misc24(self, args):
'''
# Python 2.4 only adds something like the below for if 1:
# However we will just treat it as a noop (which of course messes up
# simple verify of bytecode.
# See also below in reduce_is_invalid where we check that the JUMP_FORWARD
# target matches the COME_FROM target
stmt ::= nop_stmt
nop_stmt ::= JUMP_FORWARD POP_TOP COME_FROM
# 2.5+ has two LOAD_CONSTs, one for the number '.'s in a relative import
# keep positions similar to simplify semantic actions
import ::= filler LOAD_CONST alias
import_from ::= filler LOAD_CONST IMPORT_NAME importlist POP_TOP
import_from_star ::= filler LOAD_CONST IMPORT_NAME IMPORT_STAR
importmultiple ::= filler LOAD_CONST alias imports_cont
import_cont ::= filler LOAD_CONST alias
# Handle "if true else: ..." in Python 2.4
stmt ::= iftrue_stmt24
iftrue_stmt24 ::= _ifstmts_jump24 suite_stmts COME_FROM
_ifstmts_jump24 ::= c_stmts_opt JUMP_FORWARD POP_TOP
# Python 2.5+ omits POP_TOP POP_BLOCK
while1stmt ::= SETUP_LOOP l_stmts_opt JUMP_BACK POP_TOP POP_BLOCK COME_FROM
while1stmt ::= SETUP_LOOP l_stmts_opt JUMP_BACK POP_TOP POP_BLOCK
# Python 2.5+:
# call_stmt ::= expr POP_TOP
# expr ::= yield
call_stmt ::= yield
# Python 2.5+ adds POP_TOP at the end
gen_comp_body ::= expr YIELD_VALUE
# Python 2.4
# Python 2.6, 2.7 and 3.3+ use kv3
# Python 2.3- use kv
kvlist ::= kvlist kv2
kv2 ::= DUP_TOP expr expr ROT_THREE STORE_SUBSCR
'''
def customize_grammar_rules(self, tokens, customize):
self.remove_rules("""
gen_comp_body ::= expr YIELD_VALUE POP_TOP
kvlist ::= kvlist kv3
while1stmt ::= SETUP_LOOP l_stmts JUMP_BACK COME_FROM
while1stmt ::= SETUP_LOOP l_stmts_opt JUMP_BACK COME_FROM
while1stmt ::= SETUP_LOOP returns COME_FROM
whilestmt ::= SETUP_LOOP testexpr returns POP_BLOCK COME_FROM
with_cleanup ::= LOAD_FAST DELETE_FAST WITH_CLEANUP END_FINALLY
with_cleanup ::= LOAD_NAME DELETE_NAME WITH_CLEANUP END_FINALLY
withasstmt ::= expr setupwithas store suite_stmts_opt POP_BLOCK LOAD_CONST COME_FROM with_cleanup
withstmt ::= expr setupwith SETUP_FINALLY suite_stmts_opt POP_BLOCK LOAD_CONST COME_FROM with_cleanup
stmt ::= withstmt
stmt ::= withasstmt
""")
super(Python24Parser, self).customize_grammar_rules(tokens, customize)
if self.version == 2.4:
self.check_reduce['nop_stmt'] = 'tokens'
def reduce_is_invalid(self, rule, ast, tokens, first, last):
invalid = super(Python24Parser,
self).reduce_is_invalid(rule, ast,
tokens, first, last)
if invalid or tokens is None:
return invalid
lhs = rule[0]
if lhs == 'nop_stmt':
l = len(tokens)
if 0 <= l < len(tokens):
return not int(tokens[first].pattr) == tokens[last].offset
elif lhs == 'try_except':
if last == len(tokens):
last -= 1
if tokens[last] != 'COME_FROM' and tokens[last-1] == 'COME_FROM':
last -= 1
return (tokens[last] == 'COME_FROM'
and tokens[last-1] == 'END_FINALLY'
and tokens[last-2] == 'POP_TOP'
and tokens[last-3].kind != 'JUMP_FORWARD')
return False
class Python24ParserSingle(Python24Parser, PythonParserSingle):
pass
if __name__ == '__main__':
# Check grammar
p = Python24Parser()
p.check_grammar()