# Copyright (c) 2015-2017 Rocky Bernstein # Copyright (c) 2000-2002 by hartmut Goebel # # 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 . """ Base grammar for Python 2.x. However instead of terminal symbols being the usual ASCII text, e.g. 5, myvariable, "for", etc. they are CPython Bytecode tokens, e.g. "LOAD_CONST 5", "STORE NAME myvariable", "SETUP_LOOP", etc. If we succeed in creating a parse tree, then we have a Python program that a later phase can turn into a sequence of ASCII text. """ from __future__ import print_function from uncompyle6.parser import PythonParser, PythonParserSingle, nop_func from uncompyle6.parsers.astnode import AST from spark_parser import DEFAULT_DEBUG as PARSER_DEFAULT_DEBUG class Python2Parser(PythonParser): def __init__(self, debug_parser=PARSER_DEFAULT_DEBUG): super(Python2Parser, self).__init__(AST, 'stmts', debug=debug_parser) self.new_rules = set() def p_print2(self, args): """ stmt ::= print_items_stmt stmt ::= print_nl stmt ::= print_items_nl_stmt print_items_stmt ::= expr PRINT_ITEM print_items_opt print_items_nl_stmt ::= expr PRINT_ITEM print_items_opt PRINT_NEWLINE_CONT print_items_opt ::= print_items? print_items ::= print_item+ print_item ::= expr PRINT_ITEM_CONT print_nl ::= PRINT_NEWLINE """ def p_print_to(self, args): ''' stmt ::= print_to stmt ::= print_to_nl stmt ::= print_nl_to print_to ::= expr print_to_items POP_TOP print_to_nl ::= expr print_to_items PRINT_NEWLINE_TO print_nl_to ::= expr PRINT_NEWLINE_TO print_to_items ::= print_to_items print_to_item print_to_items ::= print_to_item print_to_item ::= DUP_TOP expr ROT_TWO PRINT_ITEM_TO ''' def p_grammar(self, args): ''' sstmt ::= stmt sstmt ::= return RETURN_LAST return_if_stmts ::= return_if_stmt return_if_stmts ::= _stmts return_if_stmt return_if_stmt ::= ret_expr RETURN_END_IF return_stmt_lambda ::= ret_expr RETURN_VALUE_LAMBDA stmt ::= break break ::= BREAK_LOOP stmt ::= continue continue ::= CONTINUE continues ::= _stmts lastl_stmt continue continues ::= lastl_stmt continue continues ::= continue stmt ::= assert2 stmt ::= raise_stmt0 stmt ::= raise_stmt1 stmt ::= raise_stmt2 stmt ::= raise_stmt3 raise_stmt0 ::= RAISE_VARARGS_0 raise_stmt1 ::= expr RAISE_VARARGS_1 raise_stmt2 ::= expr expr RAISE_VARARGS_2 raise_stmt3 ::= expr expr expr RAISE_VARARGS_3 for ::= SETUP_LOOP expr for_iter store for_block POP_BLOCK _come_froms del_stmt ::= expr DELETE_SLICE+0 del_stmt ::= expr expr DELETE_SLICE+1 del_stmt ::= expr expr DELETE_SLICE+2 del_stmt ::= expr expr expr DELETE_SLICE+3 del_stmt ::= delete_subscr delete_subscr ::= expr expr DELETE_SUBSCR del_stmt ::= expr DELETE_ATTR _mklambda ::= load_closure mklambda kwarg ::= LOAD_CONST expr kvlist ::= kvlist kv3 kv3 ::= expr expr STORE_MAP dict ::= BUILD_MAP kvlist classdef ::= buildclass store buildclass ::= LOAD_CONST expr mkfunc CALL_FUNCTION_0 BUILD_CLASS # Class decorators starting in 2.6 stmt ::= classdefdeco classdefdeco ::= classdefdeco1 store classdefdeco1 ::= expr classdefdeco1 CALL_FUNCTION_1 classdefdeco1 ::= expr classdefdeco2 CALL_FUNCTION_1 classdefdeco2 ::= LOAD_CONST expr mkfunc CALL_FUNCTION_0 BUILD_CLASS assert_expr ::= expr assert_expr ::= assert_expr_or assert_expr ::= assert_expr_and assert_expr_or ::= assert_expr jmp_true expr assert_expr_and ::= assert_expr jmp_false expr ifstmt ::= testexpr _ifstmts_jump testexpr ::= testfalse testexpr ::= testtrue testfalse ::= expr jmp_false testtrue ::= expr jmp_true _ifstmts_jump ::= return_if_stmts iflaststmt ::= testexpr c_stmts_opt JUMP_ABSOLUTE iflaststmtl ::= testexpr c_stmts_opt JUMP_BACK # this is nested inside a try_except tryfinallystmt ::= SETUP_FINALLY suite_stmts_opt POP_BLOCK LOAD_CONST COME_FROM suite_stmts_opt END_FINALLY lastc_stmt ::= tryelsestmtc # Move to 2.7? 2.6 may use come_froms tryelsestmtc ::= SETUP_EXCEPT suite_stmts_opt POP_BLOCK except_handler else_suitec COME_FROM tryelsestmtl ::= SETUP_EXCEPT suite_stmts_opt POP_BLOCK except_handler else_suitel COME_FROM try_except ::= SETUP_EXCEPT suite_stmts_opt POP_BLOCK except_handler COME_FROM except_handler ::= JUMP_FORWARD COME_FROM except_stmts END_FINALLY COME_FROM except_handler ::= jmp_abs COME_FROM except_stmts END_FINALLY except_stmts ::= except_stmt+ except_stmt ::= except_cond1 except_suite except_stmt ::= except except_suite ::= c_stmts_opt JUMP_FORWARD except_suite ::= c_stmts_opt jmp_abs except_suite ::= returns except ::= POP_TOP POP_TOP POP_TOP c_stmts_opt _jump except ::= POP_TOP POP_TOP POP_TOP returns jmp_abs ::= JUMP_ABSOLUTE jmp_abs ::= JUMP_BACK jmp_abs ::= CONTINUE ''' def p_generator_exp2(self, args): ''' generator_exp ::= LOAD_GENEXPR MAKE_FUNCTION_0 expr GET_ITER CALL_FUNCTION_1 ''' def p_expr2(self, args): """ expr ::= LOAD_LOCALS expr ::= LOAD_ASSERT expr ::= slice0 expr ::= slice1 expr ::= slice2 expr ::= slice3 expr ::= unary_convert and ::= expr jmp_false expr come_from_opt or ::= expr jmp_true expr come_from_opt unary_convert ::= expr UNARY_CONVERT # In Python 3, DUP_TOPX_2 is DUP_TOP_TWO subscript2 ::= expr expr DUP_TOPX_2 BINARY_SUBSCR """ def p_slice2(self, args): """ store ::= expr STORE_SLICE+0 store ::= expr expr STORE_SLICE+1 store ::= expr expr STORE_SLICE+2 store ::= expr expr expr STORE_SLICE+3 aug_assign1 ::= expr expr inplace_op ROT_FOUR STORE_SLICE+3 aug_assign1 ::= expr expr inplace_op ROT_THREE STORE_SLICE+1 aug_assign1 ::= expr expr inplace_op ROT_THREE STORE_SLICE+2 aug_assign1 ::= expr expr inplace_op ROT_TWO STORE_SLICE+0 slice0 ::= expr SLICE+0 slice0 ::= expr DUP_TOP SLICE+0 slice1 ::= expr expr SLICE+1 slice1 ::= expr expr DUP_TOPX_2 SLICE+1 slice2 ::= expr expr SLICE+2 slice2 ::= expr expr DUP_TOPX_2 SLICE+2 slice3 ::= expr expr expr SLICE+3 slice3 ::= expr expr expr DUP_TOPX_3 SLICE+3 """ def p_op2(self, args): """ inplace_op ::= INPLACE_DIVIDE binary_op ::= BINARY_DIVIDE """ def customize_grammar_rules(self, tokens, customize): """The base grammar we start out for a Python version even with the subclassing is, well, is pretty base. And we want it that way: lean and mean so that parsing will go faster. Here, we add additional grammar rules based on specific instructions that are in the instruction/token stream. In classes that inherit from from here and other versions, grammar rules may also be removed. For example if we see a pretty rare JUMP_IF_NOT_DEBUG instruction we'll add the grammar for that. More importantly, here we add grammar rules for instructions that may access a variable number of stack items. CALL_FUNCTION, BUILD_LIST and so on are like this. Without custom rules, there can be an super-exponential number of derivations. See the deparsing paper for an elaboration of this. """ if 'PyPy' in customize: # PyPy-specific customizations self.addRule(""" stmt ::= assign3_pypy stmt ::= assign2_pypy assign3_pypy ::= expr expr expr store store store assign2_pypy ::= expr expr store store list_comp ::= expr BUILD_LIST_FROM_ARG for_iter store list_iter JUMP_BACK """, nop_func) # For a rough break out on the first word. This may # include instructions that don't need customization, # but we'll do a finer check after the rough breakout. customize_instruction_basenames = frozenset( ('BUILD', 'CALL', 'CONTINUE', 'DELETE', 'DUP', 'EXEC', 'GET', 'JUMP', 'LOAD', 'LOOKUP', 'MAKE', 'SETUP', 'RAISE', 'UNPACK')) # Opcode names in the custom_ops_seen set have rules that get added # unconditionally and the rules are constant. So they need to be done # only once and if we see the opcode a second we don't have to consider # adding more rules. # custom_ops_seen = set() for i, token in enumerate(tokens): opname = token.kind # Do a quick breakout before testing potentially # each of the dozen or so instruction in if elif. if (opname[:opname.find('_')] not in customize_instruction_basenames or opname in custom_ops_seen): continue opname_base = opname[:opname.rfind('_')] # The order of opname listed is roughly sorted below if opname_base in ('BUILD_LIST', 'BUILD_SET', 'BUILD_TUPLE'): v = token.attr thousands = (v//1024) thirty32s = ((v//32) % 32) if thirty32s > 0: rule = "expr32 ::=%s" % (' expr' * 32) self.add_unique_rule(rule, opname_base, v, customize) self.seen32 = True if thousands > 0: self.add_unique_rule("expr1024 ::=%s" % (' expr32' * 32), opname_base, v, customize) self.seen1024 = True collection = opname_base[opname_base.find('_')+1:].lower() rule = (('%s ::= ' % collection) + 'expr1024 '*thousands + 'expr32 '*thirty32s + 'expr '*(v % 32) + opname) self.add_unique_rules([ "expr ::= %s" % collection, rule], customize) continue elif opname_base == 'BUILD_MAP': if opname == 'BUILD_MAP_n': # PyPy sometimes has no count. Sigh. self.add_unique_rules([ 'kvlist_n ::= kvlist_n kv3', 'kvlist_n ::=', 'dict ::= BUILD_MAP_n kvlist_n', ], customize) if self.version >= 2.7: self.add_unique_rule( 'dict_comp_func ::= BUILD_MAP_n LOAD_FAST FOR_ITER store ' 'comp_iter JUMP_BACK RETURN_VALUE RETURN_LAST', 'dict_comp_func', 0, customize) else: kvlist_n = "kvlist_%s" % token.attr self.add_unique_rules([ (kvlist_n + " ::=" + ' kv3' * token.attr), "dict ::= %s %s" % (opname, kvlist_n) ], customize) continue elif opname_base == 'BUILD_SLICE': slice_num = token.attr if slice_num == 2: self.add_unique_rules([ 'expr ::= build_slice2', 'build_slice2 ::= expr expr BUILD_SLICE_2' ], customize) else: assert slice_num == 3, ("BUILD_SLICE value must be 2 or 3; is %s" % slice_num) self.add_unique_rules([ 'expr ::= build_slice3', 'build_slice3 ::= expr expr expr BUILD_SLICE_3', ], customize) continue elif opname_base in ('CALL_FUNCTION', 'CALL_FUNCTION_VAR', 'CALL_FUNCTION_VAR_KW', 'CALL_FUNCTION_KW'): args_pos, args_kw = self.get_pos_kw(token) # number of apply equiv arguments: nak = ( len(opname_base)-len('CALL_FUNCTION') ) // 3 rule = 'call ::= expr ' + 'expr '*args_pos + 'kwarg '*args_kw \ + 'expr ' * nak + opname elif opname_base == 'CALL_METHOD': # PyPy only - DRY with parse3 args_pos, args_kw = self.get_pos_kw(token) # number of apply equiv arguments: nak = ( len(opname_base)-len('CALL_METHOD') ) // 3 rule = 'call ::= expr ' + 'expr '*args_pos + 'kwarg '*args_kw \ + 'expr ' * nak + opname elif opname == 'CONTINUE_LOOP': self.addRule('continue ::= CONTINUE_LOOP', nop_func) custom_ops_seen.add(opname) continue elif opname == 'DELETE_ATTR': self.addRule('del_stmt ::= expr DELETE_ATTR', nop_func) custom_ops_seen.add(opname) continue elif opname == 'DELETE_DEREF': self.addRule(""" stmt ::= del_deref_stmt del_deref_stmt ::= DELETE_DEREF """, nop_func) custom_ops_seen.add(opname) continue elif opname == 'DELETE_SUBSCR': self.addRule(""" del_stmt ::= delete_subscr delete_subscr ::= expr expr DELETE_SUBSCR """, nop_func) custom_ops_seen.add(opname) continue elif opname == 'GET_ITER': self.addRule(""" expr ::= get_iter attribute ::= expr GET_ITER """, nop_func) custom_ops_seen.add(opname) continue elif opname_base in ('DUP_TOPX', 'RAISE_VARARGS'): # FIXME: remove these conditions if they are not needed. # no longer need to add a rule continue elif opname == 'EXEC_STMT': self.addRule(""" stmt ::= exec_stmt exec_stmt ::= expr exprlist DUP_TOP EXEC_STMT exec_stmt ::= expr exprlist EXEC_STMT exprlist ::= expr+ """, nop_func) continue elif opname == 'JUMP_IF_NOT_DEBUG': v = token.attr self.addRule(""" jmp_true_false ::= POP_JUMP_IF_TRUE jmp_true_false ::= POP_JUMP_IF_FALSE stmt ::= assert_pypy stmt ::= assert2_pypy assert_pypy ::= JUMP_IF_NOT_DEBUG assert_expr jmp_true_false LOAD_ASSERT RAISE_VARARGS_1 COME_FROM assert2_pypy ::= JUMP_IF_NOT_DEBUG assert_expr jmp_true_false LOAD_ASSERT expr CALL_FUNCTION_1 RAISE_VARARGS_1 COME_FROM """, nop_func) continue elif opname == 'LOAD_ATTR': self.addRule(""" expr ::= attribute attribute ::= expr LOAD_ATTR """, nop_func) custom_ops_seen.add(opname) continue elif opname == 'LOAD_LISTCOMP': self.addRule("expr ::= listcomp", nop_func) custom_ops_seen.add(opname) continue elif opname == 'LOAD_SETCOMP': self.add_unique_rules([ "expr ::= set_comp", "set_comp ::= LOAD_SETCOMP MAKE_FUNCTION_0 expr GET_ITER CALL_FUNCTION_1" ], customize) custom_ops_seen.add(opname) continue elif opname == 'LOOKUP_METHOD': # A PyPy speciality - DRY with parse3 self.addRule(""" expr ::= attribute attribute ::= expr LOOKUP_METHOD """, nop_func) custom_ops_seen.add(opname) continue elif opname_base == 'MAKE_FUNCTION': if i > 0 and tokens[i-1] == 'LOAD_LAMBDA': self.addRule('mklambda ::= %s LOAD_LAMBDA %s' % ('pos_arg ' * token.attr, opname), nop_func) rule = 'mkfunc ::= %s LOAD_CONST %s' % ('expr ' * token.attr, opname) elif opname_base == 'MAKE_CLOSURE': # FIXME: use add_unique_rules to tidy this up. if i > 0 and tokens[i-1] == 'LOAD_LAMBDA': self.addRule('mklambda ::= %s load_closure LOAD_LAMBDA %s' % ('expr ' * token.attr, opname), nop_func) if i > 0: prev_tok = tokens[i-1] if prev_tok == 'LOAD_GENEXPR': self.add_unique_rules([ ('generator_exp ::= %s load_closure LOAD_GENEXPR %s expr' ' GET_ITER CALL_FUNCTION_1' % ('expr ' * token.attr, opname))], customize) pass self.add_unique_rules([ ('mkfunc ::= %s load_closure LOAD_CONST %s' % ('expr '* token.attr, opname))], customize) if self.version >= 2.7: if i > 0: prev_tok = tokens[i-1] if prev_tok == 'LOAD_DICTCOMP': self.add_unique_rules([ ('dict_comp ::= %s load_closure LOAD_DICTCOMP %s expr' ' GET_ITER CALL_FUNCTION_1' % ('expr ' * token.attr, opname))], customize) elif prev_tok == 'LOAD_SETCOMP': self.add_unique_rules([ "expr ::= set_comp", ('set_comp ::= %s load_closure LOAD_SETCOMP %s expr' ' GET_ITER CALL_FUNCTION_1' % ('expr ' * token.attr, opname)) ], customize) pass pass continue elif opname == 'SETUP_EXCEPT': if 'PyPy' in customize: self.add_unique_rules([ "stmt ::= try_except_pypy", "try_except_pypy ::= SETUP_EXCEPT suite_stmts_opt except_handler_pypy", "except_handler_pypy ::= COME_FROM except_stmts END_FINALLY COME_FROM" ], customize) custom_ops_seen.add(opname) continue elif opname == 'SETUP_FINALLY': if 'PyPy' in customize: self.addRule(""" stmt ::= tryfinallystmt_pypy tryfinallystmt_pypy ::= SETUP_FINALLY suite_stmts_opt COME_FROM_FINALLY suite_stmts_opt END_FINALLY""", nop_func) custom_ops_seen.add(opname) continue elif opname_base in ('UNPACK_TUPLE', 'UNPACK_SEQUENCE'): custom_ops_seen.add(opname) rule = 'unpack ::= ' + opname + ' store' * token.attr elif opname_base == 'UNPACK_LIST': custom_ops_seen.add(opname) rule = 'unpack_list ::= ' + opname + ' store' * token.attr else: continue self.addRule(rule, nop_func) pass self.check_reduce['raise_stmt1'] = 'tokens' self.check_reduce['aug_assign2'] = 'AST' self.check_reduce['or'] = 'AST' # self.check_reduce['_stmts'] = 'AST' # Dead code testing... # self.check_reduce['while1elsestmt'] = 'tokens' return def reduce_is_invalid(self, rule, ast, tokens, first, last): if tokens is None: return False lhs = rule[0] # Dead code testing... # if lhs == 'while1elsestmt': # from trepan.api import debug; debug() if lhs in ('aug_assign1', 'aug_assign2') and ast[0] and ast[0][0] in ('and', 'or'): return True elif lhs in ('raise_stmt1',): # We will assme 'LOAD_ASSERT' will be handled by an assert grammar rule return (tokens[first] == 'LOAD_ASSERT' and (last >= len(tokens) or tokens[last] != 'JUMP_FORWARD')) elif rule == ('or', ('expr', 'jmp_true', 'expr', '\\e_come_from_opt')): expr2 = ast[2] return expr2 == 'expr' and expr2[0] == 'LOAD_ASSERT' return False class Python2ParserSingle(Python2Parser, PythonParserSingle): pass if __name__ == '__main__': # Check grammar p = Python2Parser() p.check_grammar()