1109 lines
41 KiB
Python
1109 lines
41 KiB
Python
# -*- coding: utf-8 -*-
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import codecs
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import warnings
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import re
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from contextlib import contextmanager
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from parso.normalizer import Normalizer, NormalizerConfig, Issue, Rule
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from parso.python.tree import search_ancestor
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_BLOCK_STMTS = ('if_stmt', 'while_stmt', 'for_stmt', 'try_stmt', 'with_stmt')
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_STAR_EXPR_PARENTS = ('testlist_star_expr', 'testlist_comp', 'exprlist')
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# This is the maximal block size given by python.
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_MAX_BLOCK_SIZE = 20
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_MAX_INDENT_COUNT = 100
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ALLOWED_FUTURES = (
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'all_feature_names', 'nested_scopes', 'generators', 'division',
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'absolute_import', 'with_statement', 'print_function', 'unicode_literals',
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)
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_COMP_FOR_TYPES = ('comp_for', 'sync_comp_for')
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def _iter_stmts(scope):
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"""
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Iterates over all statements and splits up simple_stmt.
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"""
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for child in scope.children:
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if child.type == 'simple_stmt':
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for child2 in child.children:
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if child2.type == 'newline' or child2 == ';':
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continue
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yield child2
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else:
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yield child
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def _get_comprehension_type(atom):
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first, second = atom.children[:2]
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if second.type == 'testlist_comp' and second.children[1].type in _COMP_FOR_TYPES:
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if first == '[':
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return 'list comprehension'
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else:
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return 'generator expression'
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elif second.type == 'dictorsetmaker' and second.children[-1].type in _COMP_FOR_TYPES:
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if second.children[1] == ':':
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return 'dict comprehension'
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else:
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return 'set comprehension'
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return None
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def _is_future_import(import_from):
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# It looks like a __future__ import that is relative is still a future
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# import. That feels kind of odd, but whatever.
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# if import_from.level != 0:
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# return False
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from_names = import_from.get_from_names()
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return [n.value for n in from_names] == ['__future__']
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def _remove_parens(atom):
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"""
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Returns the inner part of an expression like `(foo)`. Also removes nested
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parens.
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"""
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try:
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children = atom.children
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except AttributeError:
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pass
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else:
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if len(children) == 3 and children[0] == '(':
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return _remove_parens(atom.children[1])
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return atom
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def _iter_params(parent_node):
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return (n for n in parent_node.children if n.type == 'param')
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def _is_future_import_first(import_from):
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"""
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Checks if the import is the first statement of a file.
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"""
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found_docstring = False
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for stmt in _iter_stmts(import_from.get_root_node()):
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if stmt.type == 'string' and not found_docstring:
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continue
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found_docstring = True
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if stmt == import_from:
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return True
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if stmt.type == 'import_from' and _is_future_import(stmt):
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continue
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return False
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def _iter_definition_exprs_from_lists(exprlist):
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def check_expr(child):
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if child.type == 'atom':
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if child.children[0] == '(':
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testlist_comp = child.children[1]
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if testlist_comp.type == 'testlist_comp':
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for expr in _iter_definition_exprs_from_lists(testlist_comp):
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yield expr
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return
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else:
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# It's a paren that doesn't do anything, like 1 + (1)
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for c in check_expr(testlist_comp):
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yield c
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return
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elif child.children[0] == '[':
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yield testlist_comp
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return
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yield child
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if exprlist.type in _STAR_EXPR_PARENTS:
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for child in exprlist.children[::2]:
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for c in check_expr(child): # Python 2 sucks
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yield c
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else:
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for c in check_expr(exprlist): # Python 2 sucks
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yield c
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def _get_expr_stmt_definition_exprs(expr_stmt):
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exprs = []
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for list_ in expr_stmt.children[:-2:2]:
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if list_.type in ('testlist_star_expr', 'testlist'):
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exprs += _iter_definition_exprs_from_lists(list_)
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else:
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exprs.append(list_)
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return exprs
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def _get_for_stmt_definition_exprs(for_stmt):
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exprlist = for_stmt.children[1]
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return list(_iter_definition_exprs_from_lists(exprlist))
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class _Context(object):
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def __init__(self, node, add_syntax_error, parent_context=None):
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self.node = node
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self.blocks = []
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self.parent_context = parent_context
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self._used_name_dict = {}
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self._global_names = []
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self._nonlocal_names = []
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self._nonlocal_names_in_subscopes = []
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self._add_syntax_error = add_syntax_error
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def is_async_funcdef(self):
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# Stupidly enough async funcdefs can have two different forms,
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# depending if a decorator is used or not.
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return self.is_function() \
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and self.node.parent.type in ('async_funcdef', 'async_stmt')
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def is_function(self):
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return self.node.type == 'funcdef'
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def add_name(self, name):
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parent_type = name.parent.type
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if parent_type == 'trailer':
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# We are only interested in first level names.
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return
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if parent_type == 'global_stmt':
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self._global_names.append(name)
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elif parent_type == 'nonlocal_stmt':
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self._nonlocal_names.append(name)
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else:
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self._used_name_dict.setdefault(name.value, []).append(name)
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def finalize(self):
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"""
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Returns a list of nonlocal names that need to be part of that scope.
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"""
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self._analyze_names(self._global_names, 'global')
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self._analyze_names(self._nonlocal_names, 'nonlocal')
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global_name_strs = {n.value: n for n in self._global_names}
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for nonlocal_name in self._nonlocal_names:
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try:
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global_name = global_name_strs[nonlocal_name.value]
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except KeyError:
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continue
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message = "name '%s' is nonlocal and global" % global_name.value
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if global_name.start_pos < nonlocal_name.start_pos:
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error_name = global_name
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else:
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error_name = nonlocal_name
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self._add_syntax_error(error_name, message)
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nonlocals_not_handled = []
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for nonlocal_name in self._nonlocal_names_in_subscopes:
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search = nonlocal_name.value
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if search in global_name_strs or self.parent_context is None:
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message = "no binding for nonlocal '%s' found" % nonlocal_name.value
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self._add_syntax_error(nonlocal_name, message)
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elif not self.is_function() or \
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nonlocal_name.value not in self._used_name_dict:
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nonlocals_not_handled.append(nonlocal_name)
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return self._nonlocal_names + nonlocals_not_handled
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def _analyze_names(self, globals_or_nonlocals, type_):
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def raise_(message):
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self._add_syntax_error(base_name, message % (base_name.value, type_))
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params = []
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if self.node.type == 'funcdef':
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params = self.node.get_params()
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for base_name in globals_or_nonlocals:
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found_global_or_nonlocal = False
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# Somehow Python does it the reversed way.
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for name in reversed(self._used_name_dict.get(base_name.value, [])):
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if name.start_pos > base_name.start_pos:
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# All following names don't have to be checked.
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found_global_or_nonlocal = True
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parent = name.parent
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if parent.type == 'param' and parent.name == name:
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# Skip those here, these definitions belong to the next
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# scope.
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continue
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if name.is_definition():
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if parent.type == 'expr_stmt' \
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and parent.children[1].type == 'annassign':
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if found_global_or_nonlocal:
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# If it's after the global the error seems to be
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# placed there.
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base_name = name
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raise_("annotated name '%s' can't be %s")
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break
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else:
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message = "name '%s' is assigned to before %s declaration"
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else:
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message = "name '%s' is used prior to %s declaration"
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if not found_global_or_nonlocal:
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raise_(message)
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# Only add an error for the first occurence.
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break
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for param in params:
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if param.name.value == base_name.value:
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raise_("name '%s' is parameter and %s"),
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@contextmanager
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def add_block(self, node):
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self.blocks.append(node)
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yield
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self.blocks.pop()
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def add_context(self, node):
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return _Context(node, self._add_syntax_error, parent_context=self)
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def close_child_context(self, child_context):
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self._nonlocal_names_in_subscopes += child_context.finalize()
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class ErrorFinder(Normalizer):
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"""
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Searches for errors in the syntax tree.
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"""
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def __init__(self, *args, **kwargs):
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super(ErrorFinder, self).__init__(*args, **kwargs)
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self._error_dict = {}
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self.version = self.grammar.version_info
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def initialize(self, node):
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def create_context(node):
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if node is None:
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return None
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parent_context = create_context(node.parent)
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if node.type in ('classdef', 'funcdef', 'file_input'):
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return _Context(node, self._add_syntax_error, parent_context)
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return parent_context
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self.context = create_context(node) or _Context(node, self._add_syntax_error)
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self._indentation_count = 0
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def visit(self, node):
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if node.type == 'error_node':
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with self.visit_node(node):
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# Don't need to investigate the inners of an error node. We
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# might find errors in there that should be ignored, because
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# the error node itself already shows that there's an issue.
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return ''
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return super(ErrorFinder, self).visit(node)
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@contextmanager
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def visit_node(self, node):
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self._check_type_rules(node)
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if node.type in _BLOCK_STMTS:
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with self.context.add_block(node):
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if len(self.context.blocks) == _MAX_BLOCK_SIZE:
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self._add_syntax_error(node, "too many statically nested blocks")
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yield
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return
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elif node.type == 'suite':
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self._indentation_count += 1
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if self._indentation_count == _MAX_INDENT_COUNT:
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self._add_indentation_error(node.children[1], "too many levels of indentation")
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yield
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if node.type == 'suite':
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self._indentation_count -= 1
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elif node.type in ('classdef', 'funcdef'):
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context = self.context
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self.context = context.parent_context
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self.context.close_child_context(context)
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def visit_leaf(self, leaf):
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if leaf.type == 'error_leaf':
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if leaf.token_type in ('INDENT', 'ERROR_DEDENT'):
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# Indents/Dedents itself never have a prefix. They are just
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# "pseudo" tokens that get removed by the syntax tree later.
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# Therefore in case of an error we also have to check for this.
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spacing = list(leaf.get_next_leaf()._split_prefix())[-1]
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if leaf.token_type == 'INDENT':
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message = 'unexpected indent'
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else:
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message = 'unindent does not match any outer indentation level'
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self._add_indentation_error(spacing, message)
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else:
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if leaf.value.startswith('\\'):
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message = 'unexpected character after line continuation character'
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else:
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match = re.match('\\w{,2}("{1,3}|\'{1,3})', leaf.value)
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if match is None:
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message = 'invalid syntax'
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else:
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if len(match.group(1)) == 1:
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message = 'EOL while scanning string literal'
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else:
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message = 'EOF while scanning triple-quoted string literal'
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self._add_syntax_error(leaf, message)
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return ''
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elif leaf.value == ':':
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parent = leaf.parent
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if parent.type in ('classdef', 'funcdef'):
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self.context = self.context.add_context(parent)
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# The rest is rule based.
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return super(ErrorFinder, self).visit_leaf(leaf)
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def _add_indentation_error(self, spacing, message):
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self.add_issue(spacing, 903, "IndentationError: " + message)
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def _add_syntax_error(self, node, message):
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self.add_issue(node, 901, "SyntaxError: " + message)
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def add_issue(self, node, code, message):
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# Overwrite the default behavior.
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# Check if the issues are on the same line.
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line = node.start_pos[0]
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args = (code, message, node)
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self._error_dict.setdefault(line, args)
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def finalize(self):
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self.context.finalize()
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for code, message, node in self._error_dict.values():
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self.issues.append(Issue(node, code, message))
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class IndentationRule(Rule):
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code = 903
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def _get_message(self, message):
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message = super(IndentationRule, self)._get_message(message)
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return "IndentationError: " + message
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@ErrorFinder.register_rule(type='error_node')
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class _ExpectIndentedBlock(IndentationRule):
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message = 'expected an indented block'
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def get_node(self, node):
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leaf = node.get_next_leaf()
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return list(leaf._split_prefix())[-1]
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def is_issue(self, node):
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# This is the beginning of a suite that is not indented.
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return node.children[-1].type == 'newline'
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class ErrorFinderConfig(NormalizerConfig):
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normalizer_class = ErrorFinder
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class SyntaxRule(Rule):
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code = 901
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def _get_message(self, message):
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message = super(SyntaxRule, self)._get_message(message)
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return "SyntaxError: " + message
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@ErrorFinder.register_rule(type='error_node')
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class _InvalidSyntaxRule(SyntaxRule):
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message = "invalid syntax"
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def get_node(self, node):
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return node.get_next_leaf()
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def is_issue(self, node):
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# Error leafs will be added later as an error.
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return node.get_next_leaf().type != 'error_leaf'
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@ErrorFinder.register_rule(value='await')
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class _AwaitOutsideAsync(SyntaxRule):
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message = "'await' outside async function"
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def is_issue(self, leaf):
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return not self._normalizer.context.is_async_funcdef()
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def get_error_node(self, node):
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# Return the whole await statement.
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return node.parent
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@ErrorFinder.register_rule(value='break')
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class _BreakOutsideLoop(SyntaxRule):
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message = "'break' outside loop"
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def is_issue(self, leaf):
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in_loop = False
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for block in self._normalizer.context.blocks:
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if block.type in ('for_stmt', 'while_stmt'):
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in_loop = True
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return not in_loop
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|
|
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@ErrorFinder.register_rule(value='continue')
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class _ContinueChecks(SyntaxRule):
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message = "'continue' not properly in loop"
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message_in_finally = "'continue' not supported inside 'finally' clause"
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def is_issue(self, leaf):
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in_loop = False
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for block in self._normalizer.context.blocks:
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if block.type in ('for_stmt', 'while_stmt'):
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in_loop = True
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if block.type == 'try_stmt':
|
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last_block = block.children[-3]
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if last_block == 'finally' and leaf.start_pos > last_block.start_pos:
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self.add_issue(leaf, message=self.message_in_finally)
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return False # Error already added
|
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if not in_loop:
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return True
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|
|
|
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@ErrorFinder.register_rule(value='from')
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class _YieldFromCheck(SyntaxRule):
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message = "'yield from' inside async function"
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def get_node(self, leaf):
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return leaf.parent.parent # This is the actual yield statement.
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def is_issue(self, leaf):
|
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return leaf.parent.type == 'yield_arg' \
|
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and self._normalizer.context.is_async_funcdef()
|
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|
|
|
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@ErrorFinder.register_rule(type='name')
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class _NameChecks(SyntaxRule):
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message = 'cannot assign to __debug__'
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message_none = 'cannot assign to None'
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def is_issue(self, leaf):
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self._normalizer.context.add_name(leaf)
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if leaf.value == '__debug__' and leaf.is_definition():
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return True
|
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if leaf.value == 'None' and self._normalizer.version < (3, 0) \
|
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and leaf.is_definition():
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self.add_issue(leaf, message=self.message_none)
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@ErrorFinder.register_rule(type='string')
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class _StringChecks(SyntaxRule):
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message = "bytes can only contain ASCII literal characters."
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def is_issue(self, leaf):
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string_prefix = leaf.string_prefix.lower()
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if 'b' in string_prefix \
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and self._normalizer.version >= (3, 0) \
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and any(c for c in leaf.value if ord(c) > 127):
|
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# b'ä'
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return True
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|
|
if 'r' not in string_prefix:
|
|
# Raw strings don't need to be checked if they have proper
|
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# escaping.
|
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is_bytes = self._normalizer.version < (3, 0)
|
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if 'b' in string_prefix:
|
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is_bytes = True
|
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if 'u' in string_prefix:
|
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is_bytes = False
|
|
|
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payload = leaf._get_payload()
|
|
if is_bytes:
|
|
payload = payload.encode('utf-8')
|
|
func = codecs.escape_decode
|
|
else:
|
|
func = codecs.unicode_escape_decode
|
|
|
|
try:
|
|
with warnings.catch_warnings():
|
|
# The warnings from parsing strings are not relevant.
|
|
warnings.filterwarnings('ignore')
|
|
func(payload)
|
|
except UnicodeDecodeError as e:
|
|
self.add_issue(leaf, message='(unicode error) ' + str(e))
|
|
except ValueError as e:
|
|
self.add_issue(leaf, message='(value error) ' + str(e))
|
|
|
|
|
|
@ErrorFinder.register_rule(value='*')
|
|
class _StarCheck(SyntaxRule):
|
|
message = "named arguments must follow bare *"
|
|
|
|
def is_issue(self, leaf):
|
|
params = leaf.parent
|
|
if params.type == 'parameters' and params:
|
|
after = params.children[params.children.index(leaf) + 1:]
|
|
after = [child for child in after
|
|
if child not in (',', ')') and not child.star_count]
|
|
return len(after) == 0
|
|
|
|
|
|
@ErrorFinder.register_rule(value='**')
|
|
class _StarStarCheck(SyntaxRule):
|
|
# e.g. {**{} for a in [1]}
|
|
# TODO this should probably get a better end_pos including
|
|
# the next sibling of leaf.
|
|
message = "dict unpacking cannot be used in dict comprehension"
|
|
|
|
def is_issue(self, leaf):
|
|
if leaf.parent.type == 'dictorsetmaker':
|
|
comp_for = leaf.get_next_sibling().get_next_sibling()
|
|
return comp_for is not None and comp_for.type in _COMP_FOR_TYPES
|
|
|
|
|
|
@ErrorFinder.register_rule(value='yield')
|
|
@ErrorFinder.register_rule(value='return')
|
|
class _ReturnAndYieldChecks(SyntaxRule):
|
|
message = "'return' with value in async generator"
|
|
message_async_yield = "'yield' inside async function"
|
|
|
|
def get_node(self, leaf):
|
|
return leaf.parent
|
|
|
|
def is_issue(self, leaf):
|
|
if self._normalizer.context.node.type != 'funcdef':
|
|
self.add_issue(self.get_node(leaf), message="'%s' outside function" % leaf.value)
|
|
elif self._normalizer.context.is_async_funcdef() \
|
|
and any(self._normalizer.context.node.iter_yield_exprs()):
|
|
if leaf.value == 'return' and leaf.parent.type == 'return_stmt':
|
|
return True
|
|
elif leaf.value == 'yield' \
|
|
and leaf.get_next_leaf() != 'from' \
|
|
and self._normalizer.version == (3, 5):
|
|
self.add_issue(self.get_node(leaf), message=self.message_async_yield)
|
|
|
|
|
|
@ErrorFinder.register_rule(type='strings')
|
|
class _BytesAndStringMix(SyntaxRule):
|
|
# e.g. 's' b''
|
|
message = "cannot mix bytes and nonbytes literals"
|
|
|
|
def _is_bytes_literal(self, string):
|
|
if string.type == 'fstring':
|
|
return False
|
|
return 'b' in string.string_prefix.lower()
|
|
|
|
def is_issue(self, node):
|
|
first = node.children[0]
|
|
# In Python 2 it's allowed to mix bytes and unicode.
|
|
if self._normalizer.version >= (3, 0):
|
|
first_is_bytes = self._is_bytes_literal(first)
|
|
for string in node.children[1:]:
|
|
if first_is_bytes != self._is_bytes_literal(string):
|
|
return True
|
|
|
|
|
|
@ErrorFinder.register_rule(type='import_as_names')
|
|
class _TrailingImportComma(SyntaxRule):
|
|
# e.g. from foo import a,
|
|
message = "trailing comma not allowed without surrounding parentheses"
|
|
|
|
def is_issue(self, node):
|
|
if node.children[-1] == ',' and node.parent.children[-1] != ')':
|
|
return True
|
|
|
|
|
|
@ErrorFinder.register_rule(type='import_from')
|
|
class _ImportStarInFunction(SyntaxRule):
|
|
message = "import * only allowed at module level"
|
|
|
|
def is_issue(self, node):
|
|
return node.is_star_import() and self._normalizer.context.parent_context is not None
|
|
|
|
|
|
@ErrorFinder.register_rule(type='import_from')
|
|
class _FutureImportRule(SyntaxRule):
|
|
message = "from __future__ imports must occur at the beginning of the file"
|
|
|
|
def is_issue(self, node):
|
|
if _is_future_import(node):
|
|
if not _is_future_import_first(node):
|
|
return True
|
|
|
|
for from_name, future_name in node.get_paths():
|
|
name = future_name.value
|
|
allowed_futures = list(ALLOWED_FUTURES)
|
|
if self._normalizer.version >= (3, 5):
|
|
allowed_futures.append('generator_stop')
|
|
|
|
if name == 'braces':
|
|
self.add_issue(node, message="not a chance")
|
|
elif name == 'barry_as_FLUFL':
|
|
m = "Seriously I'm not implementing this :) ~ Dave"
|
|
self.add_issue(node, message=m)
|
|
elif name not in ALLOWED_FUTURES:
|
|
message = "future feature %s is not defined" % name
|
|
self.add_issue(node, message=message)
|
|
|
|
|
|
@ErrorFinder.register_rule(type='star_expr')
|
|
class _StarExprRule(SyntaxRule):
|
|
message = "starred assignment target must be in a list or tuple"
|
|
message_iterable_unpacking = "iterable unpacking cannot be used in comprehension"
|
|
message_assignment = "can use starred expression only as assignment target"
|
|
|
|
def is_issue(self, node):
|
|
if node.parent.type not in _STAR_EXPR_PARENTS:
|
|
return True
|
|
if node.parent.type == 'testlist_comp':
|
|
# [*[] for a in [1]]
|
|
if node.parent.children[1].type in _COMP_FOR_TYPES:
|
|
self.add_issue(node, message=self.message_iterable_unpacking)
|
|
if self._normalizer.version <= (3, 4):
|
|
n = search_ancestor(node, 'for_stmt', 'expr_stmt')
|
|
found_definition = False
|
|
if n is not None:
|
|
if n.type == 'expr_stmt':
|
|
exprs = _get_expr_stmt_definition_exprs(n)
|
|
else:
|
|
exprs = _get_for_stmt_definition_exprs(n)
|
|
if node in exprs:
|
|
found_definition = True
|
|
|
|
if not found_definition:
|
|
self.add_issue(node, message=self.message_assignment)
|
|
|
|
|
|
@ErrorFinder.register_rule(types=_STAR_EXPR_PARENTS)
|
|
class _StarExprParentRule(SyntaxRule):
|
|
def is_issue(self, node):
|
|
if node.parent.type == 'del_stmt':
|
|
self.add_issue(node.parent, message="can't use starred expression here")
|
|
else:
|
|
def is_definition(node, ancestor):
|
|
if ancestor is None:
|
|
return False
|
|
|
|
type_ = ancestor.type
|
|
if type_ == 'trailer':
|
|
return False
|
|
|
|
if type_ == 'expr_stmt':
|
|
return node.start_pos < ancestor.children[-1].start_pos
|
|
|
|
return is_definition(node, ancestor.parent)
|
|
|
|
if is_definition(node, node.parent):
|
|
args = [c for c in node.children if c != ',']
|
|
starred = [c for c in args if c.type == 'star_expr']
|
|
if len(starred) > 1:
|
|
message = "two starred expressions in assignment"
|
|
self.add_issue(starred[1], message=message)
|
|
elif starred:
|
|
count = args.index(starred[0])
|
|
if count >= 256:
|
|
message = "too many expressions in star-unpacking assignment"
|
|
self.add_issue(starred[0], message=message)
|
|
|
|
|
|
@ErrorFinder.register_rule(type='annassign')
|
|
class _AnnotatorRule(SyntaxRule):
|
|
# True: int
|
|
# {}: float
|
|
message = "illegal target for annotation"
|
|
|
|
def get_node(self, node):
|
|
return node.parent
|
|
|
|
def is_issue(self, node):
|
|
type_ = None
|
|
lhs = node.parent.children[0]
|
|
lhs = _remove_parens(lhs)
|
|
try:
|
|
children = lhs.children
|
|
except AttributeError:
|
|
pass
|
|
else:
|
|
if ',' in children or lhs.type == 'atom' and children[0] == '(':
|
|
type_ = 'tuple'
|
|
elif lhs.type == 'atom' and children[0] == '[':
|
|
type_ = 'list'
|
|
trailer = children[-1]
|
|
|
|
if type_ is None:
|
|
if not (lhs.type == 'name'
|
|
# subscript/attributes are allowed
|
|
or lhs.type in ('atom_expr', 'power')
|
|
and trailer.type == 'trailer'
|
|
and trailer.children[0] != '('):
|
|
return True
|
|
else:
|
|
# x, y: str
|
|
message = "only single target (not %s) can be annotated"
|
|
self.add_issue(lhs.parent, message=message % type_)
|
|
|
|
|
|
@ErrorFinder.register_rule(type='argument')
|
|
class _ArgumentRule(SyntaxRule):
|
|
def is_issue(self, node):
|
|
first = node.children[0]
|
|
if node.children[1] == '=' and first.type != 'name':
|
|
if first.type == 'lambdef':
|
|
# f(lambda: 1=1)
|
|
if self._normalizer.version < (3, 8):
|
|
message = "lambda cannot contain assignment"
|
|
else:
|
|
message = 'expression cannot contain assignment, perhaps you meant "=="?'
|
|
else:
|
|
# f(+x=1)
|
|
if self._normalizer.version < (3, 8):
|
|
message = "keyword can't be an expression"
|
|
else:
|
|
message = 'expression cannot contain assignment, perhaps you meant "=="?'
|
|
self.add_issue(first, message=message)
|
|
|
|
|
|
@ErrorFinder.register_rule(type='nonlocal_stmt')
|
|
class _NonlocalModuleLevelRule(SyntaxRule):
|
|
message = "nonlocal declaration not allowed at module level"
|
|
|
|
def is_issue(self, node):
|
|
return self._normalizer.context.parent_context is None
|
|
|
|
|
|
@ErrorFinder.register_rule(type='arglist')
|
|
class _ArglistRule(SyntaxRule):
|
|
@property
|
|
def message(self):
|
|
if self._normalizer.version < (3, 7):
|
|
return "Generator expression must be parenthesized if not sole argument"
|
|
else:
|
|
return "Generator expression must be parenthesized"
|
|
|
|
def is_issue(self, node):
|
|
first_arg = node.children[0]
|
|
if first_arg.type == 'argument' \
|
|
and first_arg.children[1].type in _COMP_FOR_TYPES:
|
|
# e.g. foo(x for x in [], b)
|
|
return len(node.children) >= 2
|
|
else:
|
|
arg_set = set()
|
|
kw_only = False
|
|
kw_unpacking_only = False
|
|
is_old_starred = False
|
|
# In python 3 this would be a bit easier (stars are part of
|
|
# argument), but we have to understand both.
|
|
for argument in node.children:
|
|
if argument == ',':
|
|
continue
|
|
|
|
if argument in ('*', '**'):
|
|
# Python < 3.5 has the order engraved in the grammar
|
|
# file. No need to do anything here.
|
|
is_old_starred = True
|
|
continue
|
|
if is_old_starred:
|
|
is_old_starred = False
|
|
continue
|
|
|
|
if argument.type == 'argument':
|
|
first = argument.children[0]
|
|
if first in ('*', '**'):
|
|
if first == '*':
|
|
if kw_unpacking_only:
|
|
# foo(**kwargs, *args)
|
|
message = "iterable argument unpacking " \
|
|
"follows keyword argument unpacking"
|
|
self.add_issue(argument, message=message)
|
|
else:
|
|
kw_unpacking_only = True
|
|
else: # Is a keyword argument.
|
|
kw_only = True
|
|
if first.type == 'name':
|
|
if first.value in arg_set:
|
|
# f(x=1, x=2)
|
|
self.add_issue(first, message="keyword argument repeated")
|
|
else:
|
|
arg_set.add(first.value)
|
|
else:
|
|
if kw_unpacking_only:
|
|
# f(**x, y)
|
|
message = "positional argument follows keyword argument unpacking"
|
|
self.add_issue(argument, message=message)
|
|
elif kw_only:
|
|
# f(x=2, y)
|
|
message = "positional argument follows keyword argument"
|
|
self.add_issue(argument, message=message)
|
|
|
|
|
|
@ErrorFinder.register_rule(type='parameters')
|
|
@ErrorFinder.register_rule(type='lambdef')
|
|
class _ParameterRule(SyntaxRule):
|
|
# def f(x=3, y): pass
|
|
message = "non-default argument follows default argument"
|
|
|
|
def is_issue(self, node):
|
|
param_names = set()
|
|
default_only = False
|
|
for p in _iter_params(node):
|
|
if p.name.value in param_names:
|
|
message = "duplicate argument '%s' in function definition"
|
|
self.add_issue(p.name, message=message % p.name.value)
|
|
param_names.add(p.name.value)
|
|
|
|
if p.default is None and not p.star_count:
|
|
if default_only:
|
|
return True
|
|
else:
|
|
default_only = True
|
|
|
|
|
|
@ErrorFinder.register_rule(type='try_stmt')
|
|
class _TryStmtRule(SyntaxRule):
|
|
message = "default 'except:' must be last"
|
|
|
|
def is_issue(self, try_stmt):
|
|
default_except = None
|
|
for except_clause in try_stmt.children[3::3]:
|
|
if except_clause in ('else', 'finally'):
|
|
break
|
|
if except_clause == 'except':
|
|
default_except = except_clause
|
|
elif default_except is not None:
|
|
self.add_issue(default_except, message=self.message)
|
|
|
|
|
|
@ErrorFinder.register_rule(type='fstring')
|
|
class _FStringRule(SyntaxRule):
|
|
_fstring_grammar = None
|
|
message_expr = "f-string expression part cannot include a backslash"
|
|
message_nested = "f-string: expressions nested too deeply"
|
|
message_conversion = "f-string: invalid conversion character: expected 's', 'r', or 'a'"
|
|
|
|
def _check_format_spec(self, format_spec, depth):
|
|
self._check_fstring_contents(format_spec.children[1:], depth)
|
|
|
|
def _check_fstring_expr(self, fstring_expr, depth):
|
|
if depth >= 2:
|
|
self.add_issue(fstring_expr, message=self.message_nested)
|
|
|
|
expr = fstring_expr.children[1]
|
|
if '\\' in expr.get_code():
|
|
self.add_issue(expr, message=self.message_expr)
|
|
|
|
conversion = fstring_expr.children[2]
|
|
if conversion.type == 'fstring_conversion':
|
|
name = conversion.children[1]
|
|
if name.value not in ('s', 'r', 'a'):
|
|
self.add_issue(name, message=self.message_conversion)
|
|
|
|
format_spec = fstring_expr.children[-2]
|
|
if format_spec.type == 'fstring_format_spec':
|
|
self._check_format_spec(format_spec, depth + 1)
|
|
|
|
def is_issue(self, fstring):
|
|
self._check_fstring_contents(fstring.children[1:-1])
|
|
|
|
def _check_fstring_contents(self, children, depth=0):
|
|
for fstring_content in children:
|
|
if fstring_content.type == 'fstring_expr':
|
|
self._check_fstring_expr(fstring_content, depth)
|
|
|
|
|
|
class _CheckAssignmentRule(SyntaxRule):
|
|
def _check_assignment(self, node, is_deletion=False, is_namedexpr=False):
|
|
error = None
|
|
type_ = node.type
|
|
if type_ == 'lambdef':
|
|
error = 'lambda'
|
|
elif type_ == 'atom':
|
|
first, second = node.children[:2]
|
|
error = _get_comprehension_type(node)
|
|
if error is None:
|
|
if second.type == 'dictorsetmaker':
|
|
if self._normalizer.version < (3, 8):
|
|
error = 'literal'
|
|
else:
|
|
if second.children[1] == ':':
|
|
error = 'dict display'
|
|
else:
|
|
error = 'set display'
|
|
elif first in ('(', '['):
|
|
if second.type == 'yield_expr':
|
|
error = 'yield expression'
|
|
elif second.type == 'testlist_comp':
|
|
# ([a, b] := [1, 2])
|
|
# ((a, b) := [1, 2])
|
|
if is_namedexpr:
|
|
if first == '(':
|
|
error = 'tuple'
|
|
elif first == '[':
|
|
error = 'list'
|
|
|
|
# This is not a comprehension, they were handled
|
|
# further above.
|
|
for child in second.children[::2]:
|
|
self._check_assignment(child, is_deletion, is_namedexpr)
|
|
else: # Everything handled, must be useless brackets.
|
|
self._check_assignment(second, is_deletion, is_namedexpr)
|
|
elif type_ == 'keyword':
|
|
if self._normalizer.version < (3, 8):
|
|
error = 'keyword'
|
|
else:
|
|
error = str(node.value)
|
|
elif type_ == 'operator':
|
|
if node.value == '...':
|
|
error = 'Ellipsis'
|
|
elif type_ == 'comparison':
|
|
error = 'comparison'
|
|
elif type_ in ('string', 'number', 'strings'):
|
|
error = 'literal'
|
|
elif type_ == 'yield_expr':
|
|
# This one seems to be a slightly different warning in Python.
|
|
message = 'assignment to yield expression not possible'
|
|
self.add_issue(node, message=message)
|
|
elif type_ == 'test':
|
|
error = 'conditional expression'
|
|
elif type_ in ('atom_expr', 'power'):
|
|
if node.children[0] == 'await':
|
|
error = 'await expression'
|
|
elif node.children[-2] == '**':
|
|
error = 'operator'
|
|
else:
|
|
# Has a trailer
|
|
trailer = node.children[-1]
|
|
assert trailer.type == 'trailer'
|
|
if trailer.children[0] == '(':
|
|
error = 'function call'
|
|
elif is_namedexpr and trailer.children[0] == '[':
|
|
error = 'subscript'
|
|
elif is_namedexpr and trailer.children[0] == '.':
|
|
error = 'attribute'
|
|
elif type_ in ('testlist_star_expr', 'exprlist', 'testlist'):
|
|
for child in node.children[::2]:
|
|
self._check_assignment(child, is_deletion, is_namedexpr)
|
|
elif ('expr' in type_ and type_ != 'star_expr' # is a substring
|
|
or '_test' in type_
|
|
or type_ in ('term', 'factor')):
|
|
error = 'operator'
|
|
|
|
if error is not None:
|
|
if is_namedexpr:
|
|
message = 'cannot use assignment expressions with %s' % error
|
|
else:
|
|
cannot = "can't" if self._normalizer.version < (3, 8) else "cannot"
|
|
message = ' '.join([cannot, "delete" if is_deletion else "assign to", error])
|
|
self.add_issue(node, message=message)
|
|
|
|
|
|
@ErrorFinder.register_rule(type='sync_comp_for')
|
|
class _CompForRule(_CheckAssignmentRule):
|
|
message = "asynchronous comprehension outside of an asynchronous function"
|
|
|
|
def is_issue(self, node):
|
|
expr_list = node.children[1]
|
|
if expr_list.type != 'expr_list': # Already handled.
|
|
self._check_assignment(expr_list)
|
|
|
|
return node.parent.children[0] == 'async' \
|
|
and not self._normalizer.context.is_async_funcdef()
|
|
|
|
|
|
@ErrorFinder.register_rule(type='expr_stmt')
|
|
class _ExprStmtRule(_CheckAssignmentRule):
|
|
message = "illegal expression for augmented assignment"
|
|
|
|
def is_issue(self, node):
|
|
for before_equal in node.children[:-2:2]:
|
|
self._check_assignment(before_equal)
|
|
|
|
augassign = node.children[1]
|
|
if augassign != '=' and augassign.type != 'annassign': # Is augassign.
|
|
return node.children[0].type in ('testlist_star_expr', 'atom', 'testlist')
|
|
|
|
|
|
@ErrorFinder.register_rule(type='with_item')
|
|
class _WithItemRule(_CheckAssignmentRule):
|
|
def is_issue(self, with_item):
|
|
self._check_assignment(with_item.children[2])
|
|
|
|
|
|
@ErrorFinder.register_rule(type='del_stmt')
|
|
class _DelStmtRule(_CheckAssignmentRule):
|
|
def is_issue(self, del_stmt):
|
|
child = del_stmt.children[1]
|
|
|
|
if child.type != 'expr_list': # Already handled.
|
|
self._check_assignment(child, is_deletion=True)
|
|
|
|
|
|
@ErrorFinder.register_rule(type='expr_list')
|
|
class _ExprListRule(_CheckAssignmentRule):
|
|
def is_issue(self, expr_list):
|
|
for expr in expr_list.children[::2]:
|
|
self._check_assignment(expr)
|
|
|
|
|
|
@ErrorFinder.register_rule(type='for_stmt')
|
|
class _ForStmtRule(_CheckAssignmentRule):
|
|
def is_issue(self, for_stmt):
|
|
# Some of the nodes here are already used, so no else if
|
|
expr_list = for_stmt.children[1]
|
|
if expr_list.type != 'expr_list': # Already handled.
|
|
self._check_assignment(expr_list)
|
|
|
|
|
|
@ErrorFinder.register_rule(type='namedexpr_test')
|
|
class _NamedExprRule(_CheckAssignmentRule):
|
|
# namedexpr_test: test [':=' test]
|
|
|
|
def is_issue(self, namedexpr_test):
|
|
# assigned name
|
|
first = namedexpr_test.children[0]
|
|
|
|
def search_namedexpr_in_comp_for(node):
|
|
while True:
|
|
parent = node.parent
|
|
if parent is None:
|
|
return parent
|
|
if parent.type == 'sync_comp_for' and parent.children[3] == node:
|
|
return parent
|
|
node = parent
|
|
|
|
if search_namedexpr_in_comp_for(namedexpr_test):
|
|
# [i+1 for i in (i := range(5))]
|
|
# [i+1 for i in (j := range(5))]
|
|
# [i+1 for i in (lambda: (j := range(5)))()]
|
|
message = 'assignment expression cannot be used in a comprehension iterable expression'
|
|
self.add_issue(namedexpr_test, message=message)
|
|
|
|
# defined names
|
|
exprlist = list()
|
|
|
|
def process_comp_for(comp_for):
|
|
if comp_for.type == 'sync_comp_for':
|
|
comp = comp_for
|
|
elif comp_for.type == 'comp_for':
|
|
comp = comp_for.children[1]
|
|
exprlist.extend(_get_for_stmt_definition_exprs(comp))
|
|
|
|
def search_all_comp_ancestors(node):
|
|
has_ancestors = False
|
|
while True:
|
|
node = search_ancestor(node, 'testlist_comp', 'dictorsetmaker')
|
|
if node is None:
|
|
break
|
|
for child in node.children:
|
|
if child.type in _COMP_FOR_TYPES:
|
|
process_comp_for(child)
|
|
has_ancestors = True
|
|
break
|
|
return has_ancestors
|
|
|
|
# check assignment expressions in comprehensions
|
|
search_all = search_all_comp_ancestors(namedexpr_test)
|
|
if search_all:
|
|
if self._normalizer.context.node.type == 'classdef':
|
|
message = 'assignment expression within a comprehension ' \
|
|
'cannot be used in a class body'
|
|
self.add_issue(namedexpr_test, message=message)
|
|
|
|
namelist = [expr.value for expr in exprlist if expr.type == 'name']
|
|
if first.type == 'name' and first.value in namelist:
|
|
# [i := 0 for i, j in range(5)]
|
|
# [[(i := i) for j in range(5)] for i in range(5)]
|
|
# [i for i, j in range(5) if True or (i := 1)]
|
|
# [False and (i := 0) for i, j in range(5)]
|
|
message = 'assignment expression cannot rebind ' \
|
|
'comprehension iteration variable %r' % first.value
|
|
self.add_issue(namedexpr_test, message=message)
|
|
|
|
self._check_assignment(first, is_namedexpr=True)
|