Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/parso/python/errors.py: 74%
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« prev ^ index » next coverage.py v7.2.2, created at 2023-03-26 07:36 +0000
1# -*- coding: utf-8 -*-
2import codecs
3import sys
4import warnings
5import re
6from contextlib import contextmanager
8from parso.normalizer import Normalizer, NormalizerConfig, Issue, Rule
9from parso.python.tokenize import _get_token_collection
11_BLOCK_STMTS = ('if_stmt', 'while_stmt', 'for_stmt', 'try_stmt', 'with_stmt')
12_STAR_EXPR_PARENTS = ('testlist_star_expr', 'testlist_comp', 'exprlist')
13# This is the maximal block size given by python.
14_MAX_BLOCK_SIZE = 20
15_MAX_INDENT_COUNT = 100
16ALLOWED_FUTURES = (
17 'nested_scopes', 'generators', 'division', 'absolute_import',
18 'with_statement', 'print_function', 'unicode_literals', 'generator_stop',
19)
20_COMP_FOR_TYPES = ('comp_for', 'sync_comp_for')
23def _get_rhs_name(node, version):
24 type_ = node.type
25 if type_ == "lambdef":
26 return "lambda"
27 elif type_ == "atom":
28 comprehension = _get_comprehension_type(node)
29 first, second = node.children[:2]
30 if comprehension is not None:
31 return comprehension
32 elif second.type == "dictorsetmaker":
33 if version < (3, 8):
34 return "literal"
35 else:
36 if second.children[1] == ":" or second.children[0] == "**":
37 if version < (3, 10):
38 return "dict display"
39 else:
40 return "dict literal"
41 else:
42 return "set display"
43 elif (
44 first == "("
45 and (second == ")"
46 or (len(node.children) == 3 and node.children[1].type == "testlist_comp"))
47 ):
48 return "tuple"
49 elif first == "(":
50 return _get_rhs_name(_remove_parens(node), version=version)
51 elif first == "[":
52 return "list"
53 elif first == "{" and second == "}":
54 if version < (3, 10):
55 return "dict display"
56 else:
57 return "dict literal"
58 elif first == "{" and len(node.children) > 2:
59 return "set display"
60 elif type_ == "keyword":
61 if "yield" in node.value:
62 return "yield expression"
63 if version < (3, 8):
64 return "keyword"
65 else:
66 return str(node.value)
67 elif type_ == "operator" and node.value == "...":
68 if version < (3, 10):
69 return "Ellipsis"
70 else:
71 return "ellipsis"
72 elif type_ == "comparison":
73 return "comparison"
74 elif type_ in ("string", "number", "strings"):
75 return "literal"
76 elif type_ == "yield_expr":
77 return "yield expression"
78 elif type_ == "test":
79 return "conditional expression"
80 elif type_ in ("atom_expr", "power"):
81 if node.children[0] == "await":
82 return "await expression"
83 elif node.children[-1].type == "trailer":
84 trailer = node.children[-1]
85 if trailer.children[0] == "(":
86 return "function call"
87 elif trailer.children[0] == "[":
88 return "subscript"
89 elif trailer.children[0] == ".":
90 return "attribute"
91 elif (
92 ("expr" in type_ and "star_expr" not in type_) # is a substring
93 or "_test" in type_
94 or type_ in ("term", "factor")
95 ):
96 if version < (3, 10):
97 return "operator"
98 else:
99 return "expression"
100 elif type_ == "star_expr":
101 return "starred"
102 elif type_ == "testlist_star_expr":
103 return "tuple"
104 elif type_ == "fstring":
105 return "f-string expression"
106 return type_ # shouldn't reach here
109def _iter_stmts(scope):
110 """
111 Iterates over all statements and splits up simple_stmt.
112 """
113 for child in scope.children:
114 if child.type == 'simple_stmt':
115 for child2 in child.children:
116 if child2.type == 'newline' or child2 == ';':
117 continue
118 yield child2
119 else:
120 yield child
123def _get_comprehension_type(atom):
124 first, second = atom.children[:2]
125 if second.type == 'testlist_comp' and second.children[1].type in _COMP_FOR_TYPES:
126 if first == '[':
127 return 'list comprehension'
128 else:
129 return 'generator expression'
130 elif second.type == 'dictorsetmaker' and second.children[-1].type in _COMP_FOR_TYPES:
131 if second.children[1] == ':':
132 return 'dict comprehension'
133 else:
134 return 'set comprehension'
135 return None
138def _is_future_import(import_from):
139 # It looks like a __future__ import that is relative is still a future
140 # import. That feels kind of odd, but whatever.
141 # if import_from.level != 0:
142 # return False
143 from_names = import_from.get_from_names()
144 return [n.value for n in from_names] == ['__future__']
147def _remove_parens(atom):
148 """
149 Returns the inner part of an expression like `(foo)`. Also removes nested
150 parens.
151 """
152 try:
153 children = atom.children
154 except AttributeError:
155 pass
156 else:
157 if len(children) == 3 and children[0] == '(':
158 return _remove_parens(atom.children[1])
159 return atom
162def _skip_parens_bottom_up(node):
163 """
164 Returns an ancestor node of an expression, skipping all levels of parens
165 bottom-up.
166 """
167 while node.parent is not None:
168 node = node.parent
169 if node.type != 'atom' or node.children[0] != '(':
170 return node
171 return None
174def _iter_params(parent_node):
175 return (n for n in parent_node.children if n.type == 'param' or n.type == 'operator')
178def _is_future_import_first(import_from):
179 """
180 Checks if the import is the first statement of a file.
181 """
182 found_docstring = False
183 for stmt in _iter_stmts(import_from.get_root_node()):
184 if stmt.type == 'string' and not found_docstring:
185 continue
186 found_docstring = True
188 if stmt == import_from:
189 return True
190 if stmt.type == 'import_from' and _is_future_import(stmt):
191 continue
192 return False
195def _iter_definition_exprs_from_lists(exprlist):
196 def check_expr(child):
197 if child.type == 'atom':
198 if child.children[0] == '(':
199 testlist_comp = child.children[1]
200 if testlist_comp.type == 'testlist_comp':
201 yield from _iter_definition_exprs_from_lists(testlist_comp)
202 return
203 else:
204 # It's a paren that doesn't do anything, like 1 + (1)
205 yield from check_expr(testlist_comp)
206 return
207 elif child.children[0] == '[':
208 yield testlist_comp
209 return
210 yield child
212 if exprlist.type in _STAR_EXPR_PARENTS:
213 for child in exprlist.children[::2]:
214 yield from check_expr(child)
215 else:
216 yield from check_expr(exprlist)
219def _get_expr_stmt_definition_exprs(expr_stmt):
220 exprs = []
221 for list_ in expr_stmt.children[:-2:2]:
222 if list_.type in ('testlist_star_expr', 'testlist'):
223 exprs += _iter_definition_exprs_from_lists(list_)
224 else:
225 exprs.append(list_)
226 return exprs
229def _get_for_stmt_definition_exprs(for_stmt):
230 exprlist = for_stmt.children[1]
231 return list(_iter_definition_exprs_from_lists(exprlist))
234def _is_argument_comprehension(argument):
235 return argument.children[1].type in _COMP_FOR_TYPES
238def _any_fstring_error(version, node):
239 if version < (3, 9) or node is None:
240 return False
241 if node.type == "error_node":
242 return any(child.type == "fstring_start" for child in node.children)
243 elif node.type == "fstring":
244 return True
245 else:
246 return node.search_ancestor("fstring")
249class _Context:
250 def __init__(self, node, add_syntax_error, parent_context=None):
251 self.node = node
252 self.blocks = []
253 self.parent_context = parent_context
254 self._used_name_dict = {}
255 self._global_names = []
256 self._local_params_names = []
257 self._nonlocal_names = []
258 self._nonlocal_names_in_subscopes = []
259 self._add_syntax_error = add_syntax_error
261 def is_async_funcdef(self):
262 # Stupidly enough async funcdefs can have two different forms,
263 # depending if a decorator is used or not.
264 return self.is_function() \
265 and self.node.parent.type in ('async_funcdef', 'async_stmt')
267 def is_function(self):
268 return self.node.type == 'funcdef'
270 def add_name(self, name):
271 parent_type = name.parent.type
272 if parent_type == 'trailer':
273 # We are only interested in first level names.
274 return
276 if parent_type == 'global_stmt':
277 self._global_names.append(name)
278 elif parent_type == 'nonlocal_stmt':
279 self._nonlocal_names.append(name)
280 elif parent_type == 'funcdef':
281 self._local_params_names.extend(
282 [param.name.value for param in name.parent.get_params()]
283 )
284 else:
285 self._used_name_dict.setdefault(name.value, []).append(name)
287 def finalize(self):
288 """
289 Returns a list of nonlocal names that need to be part of that scope.
290 """
291 self._analyze_names(self._global_names, 'global')
292 self._analyze_names(self._nonlocal_names, 'nonlocal')
294 global_name_strs = {n.value: n for n in self._global_names}
295 for nonlocal_name in self._nonlocal_names:
296 try:
297 global_name = global_name_strs[nonlocal_name.value]
298 except KeyError:
299 continue
301 message = "name '%s' is nonlocal and global" % global_name.value
302 if global_name.start_pos < nonlocal_name.start_pos:
303 error_name = global_name
304 else:
305 error_name = nonlocal_name
306 self._add_syntax_error(error_name, message)
308 nonlocals_not_handled = []
309 for nonlocal_name in self._nonlocal_names_in_subscopes:
310 search = nonlocal_name.value
311 if search in self._local_params_names:
312 continue
313 if search in global_name_strs or self.parent_context is None:
314 message = "no binding for nonlocal '%s' found" % nonlocal_name.value
315 self._add_syntax_error(nonlocal_name, message)
316 elif not self.is_function() or \
317 nonlocal_name.value not in self._used_name_dict:
318 nonlocals_not_handled.append(nonlocal_name)
319 return self._nonlocal_names + nonlocals_not_handled
321 def _analyze_names(self, globals_or_nonlocals, type_):
322 def raise_(message):
323 self._add_syntax_error(base_name, message % (base_name.value, type_))
325 params = []
326 if self.node.type == 'funcdef':
327 params = self.node.get_params()
329 for base_name in globals_or_nonlocals:
330 found_global_or_nonlocal = False
331 # Somehow Python does it the reversed way.
332 for name in reversed(self._used_name_dict.get(base_name.value, [])):
333 if name.start_pos > base_name.start_pos:
334 # All following names don't have to be checked.
335 found_global_or_nonlocal = True
337 parent = name.parent
338 if parent.type == 'param' and parent.name == name:
339 # Skip those here, these definitions belong to the next
340 # scope.
341 continue
343 if name.is_definition():
344 if parent.type == 'expr_stmt' \
345 and parent.children[1].type == 'annassign':
346 if found_global_or_nonlocal:
347 # If it's after the global the error seems to be
348 # placed there.
349 base_name = name
350 raise_("annotated name '%s' can't be %s")
351 break
352 else:
353 message = "name '%s' is assigned to before %s declaration"
354 else:
355 message = "name '%s' is used prior to %s declaration"
357 if not found_global_or_nonlocal:
358 raise_(message)
359 # Only add an error for the first occurence.
360 break
362 for param in params:
363 if param.name.value == base_name.value:
364 raise_("name '%s' is parameter and %s"),
366 @contextmanager
367 def add_block(self, node):
368 self.blocks.append(node)
369 yield
370 self.blocks.pop()
372 def add_context(self, node):
373 return _Context(node, self._add_syntax_error, parent_context=self)
375 def close_child_context(self, child_context):
376 self._nonlocal_names_in_subscopes += child_context.finalize()
379class ErrorFinder(Normalizer):
380 """
381 Searches for errors in the syntax tree.
382 """
383 def __init__(self, *args, **kwargs):
384 super().__init__(*args, **kwargs)
385 self._error_dict = {}
386 self.version = self.grammar.version_info
388 def initialize(self, node):
389 def create_context(node):
390 if node is None:
391 return None
393 parent_context = create_context(node.parent)
394 if node.type in ('classdef', 'funcdef', 'file_input'):
395 return _Context(node, self._add_syntax_error, parent_context)
396 return parent_context
398 self.context = create_context(node) or _Context(node, self._add_syntax_error)
399 self._indentation_count = 0
401 def visit(self, node):
402 if node.type == 'error_node':
403 with self.visit_node(node):
404 # Don't need to investigate the inners of an error node. We
405 # might find errors in there that should be ignored, because
406 # the error node itself already shows that there's an issue.
407 return ''
408 return super().visit(node)
410 @contextmanager
411 def visit_node(self, node):
412 self._check_type_rules(node)
414 if node.type in _BLOCK_STMTS:
415 with self.context.add_block(node):
416 if len(self.context.blocks) == _MAX_BLOCK_SIZE:
417 self._add_syntax_error(node, "too many statically nested blocks")
418 yield
419 return
420 elif node.type == 'suite':
421 self._indentation_count += 1
422 if self._indentation_count == _MAX_INDENT_COUNT:
423 self._add_indentation_error(node.children[1], "too many levels of indentation")
425 yield
427 if node.type == 'suite':
428 self._indentation_count -= 1
429 elif node.type in ('classdef', 'funcdef'):
430 context = self.context
431 self.context = context.parent_context
432 self.context.close_child_context(context)
434 def visit_leaf(self, leaf):
435 if leaf.type == 'error_leaf':
436 if leaf.token_type in ('INDENT', 'ERROR_DEDENT'):
437 # Indents/Dedents itself never have a prefix. They are just
438 # "pseudo" tokens that get removed by the syntax tree later.
439 # Therefore in case of an error we also have to check for this.
440 spacing = list(leaf.get_next_leaf()._split_prefix())[-1]
441 if leaf.token_type == 'INDENT':
442 message = 'unexpected indent'
443 else:
444 message = 'unindent does not match any outer indentation level'
445 self._add_indentation_error(spacing, message)
446 else:
447 if leaf.value.startswith('\\'):
448 message = 'unexpected character after line continuation character'
449 else:
450 match = re.match('\\w{,2}("{1,3}|\'{1,3})', leaf.value)
451 if match is None:
452 message = 'invalid syntax'
453 if (
454 self.version >= (3, 9)
455 and leaf.value in _get_token_collection(
456 self.version
457 ).always_break_tokens
458 ):
459 message = "f-string: " + message
460 else:
461 if len(match.group(1)) == 1:
462 message = 'EOL while scanning string literal'
463 else:
464 message = 'EOF while scanning triple-quoted string literal'
465 self._add_syntax_error(leaf, message)
466 return ''
467 elif leaf.value == ':':
468 parent = leaf.parent
469 if parent.type in ('classdef', 'funcdef'):
470 self.context = self.context.add_context(parent)
472 # The rest is rule based.
473 return super().visit_leaf(leaf)
475 def _add_indentation_error(self, spacing, message):
476 self.add_issue(spacing, 903, "IndentationError: " + message)
478 def _add_syntax_error(self, node, message):
479 self.add_issue(node, 901, "SyntaxError: " + message)
481 def add_issue(self, node, code, message):
482 # Overwrite the default behavior.
483 # Check if the issues are on the same line.
484 line = node.start_pos[0]
485 args = (code, message, node)
486 self._error_dict.setdefault(line, args)
488 def finalize(self):
489 self.context.finalize()
491 for code, message, node in self._error_dict.values():
492 self.issues.append(Issue(node, code, message))
495class IndentationRule(Rule):
496 code = 903
498 def _get_message(self, message, node):
499 message = super()._get_message(message, node)
500 return "IndentationError: " + message
503@ErrorFinder.register_rule(type='error_node')
504class _ExpectIndentedBlock(IndentationRule):
505 message = 'expected an indented block'
507 def get_node(self, node):
508 leaf = node.get_next_leaf()
509 return list(leaf._split_prefix())[-1]
511 def is_issue(self, node):
512 # This is the beginning of a suite that is not indented.
513 return node.children[-1].type == 'newline'
516class ErrorFinderConfig(NormalizerConfig):
517 normalizer_class = ErrorFinder
520class SyntaxRule(Rule):
521 code = 901
523 def _get_message(self, message, node):
524 message = super()._get_message(message, node)
525 if (
526 "f-string" not in message
527 and _any_fstring_error(self._normalizer.version, node)
528 ):
529 message = "f-string: " + message
530 return "SyntaxError: " + message
533@ErrorFinder.register_rule(type='error_node')
534class _InvalidSyntaxRule(SyntaxRule):
535 message = "invalid syntax"
536 fstring_message = "f-string: invalid syntax"
538 def get_node(self, node):
539 return node.get_next_leaf()
541 def is_issue(self, node):
542 error = node.get_next_leaf().type != 'error_leaf'
543 if (
544 error
545 and _any_fstring_error(self._normalizer.version, node)
546 ):
547 self.add_issue(node, message=self.fstring_message)
548 else:
549 # Error leafs will be added later as an error.
550 return error
553@ErrorFinder.register_rule(value='await')
554class _AwaitOutsideAsync(SyntaxRule):
555 message = "'await' outside async function"
557 def is_issue(self, leaf):
558 return not self._normalizer.context.is_async_funcdef()
560 def get_error_node(self, node):
561 # Return the whole await statement.
562 return node.parent
565@ErrorFinder.register_rule(value='break')
566class _BreakOutsideLoop(SyntaxRule):
567 message = "'break' outside loop"
569 def is_issue(self, leaf):
570 in_loop = False
571 for block in self._normalizer.context.blocks:
572 if block.type in ('for_stmt', 'while_stmt'):
573 in_loop = True
574 return not in_loop
577@ErrorFinder.register_rule(value='continue')
578class _ContinueChecks(SyntaxRule):
579 message = "'continue' not properly in loop"
580 message_in_finally = "'continue' not supported inside 'finally' clause"
582 def is_issue(self, leaf):
583 in_loop = False
584 for block in self._normalizer.context.blocks:
585 if block.type in ('for_stmt', 'while_stmt'):
586 in_loop = True
587 if block.type == 'try_stmt':
588 last_block = block.children[-3]
589 if (
590 last_block == "finally"
591 and leaf.start_pos > last_block.start_pos
592 and self._normalizer.version < (3, 8)
593 ):
594 self.add_issue(leaf, message=self.message_in_finally)
595 return False # Error already added
596 if not in_loop:
597 return True
600@ErrorFinder.register_rule(value='from')
601class _YieldFromCheck(SyntaxRule):
602 message = "'yield from' inside async function"
604 def get_node(self, leaf):
605 return leaf.parent.parent # This is the actual yield statement.
607 def is_issue(self, leaf):
608 return leaf.parent.type == 'yield_arg' \
609 and self._normalizer.context.is_async_funcdef()
612@ErrorFinder.register_rule(type='name')
613class _NameChecks(SyntaxRule):
614 message = 'cannot assign to __debug__'
615 message_none = 'cannot assign to None'
617 def is_issue(self, leaf):
618 self._normalizer.context.add_name(leaf)
620 if leaf.value == '__debug__' and leaf.is_definition():
621 return True
624@ErrorFinder.register_rule(type='string')
625class _StringChecks(SyntaxRule):
626 if sys.version_info < (3, 10):
627 message = "bytes can only contain ASCII literal characters."
628 else:
629 message = "bytes can only contain ASCII literal characters"
631 def is_issue(self, leaf):
632 string_prefix = leaf.string_prefix.lower()
633 if 'b' in string_prefix \
634 and any(c for c in leaf.value if ord(c) > 127):
635 # b'ä'
636 return True
638 if 'r' not in string_prefix:
639 # Raw strings don't need to be checked if they have proper
640 # escaping.
642 payload = leaf._get_payload()
643 if 'b' in string_prefix:
644 payload = payload.encode('utf-8')
645 func = codecs.escape_decode
646 else:
647 func = codecs.unicode_escape_decode
649 try:
650 with warnings.catch_warnings():
651 # The warnings from parsing strings are not relevant.
652 warnings.filterwarnings('ignore')
653 func(payload)
654 except UnicodeDecodeError as e:
655 self.add_issue(leaf, message='(unicode error) ' + str(e))
656 except ValueError as e:
657 self.add_issue(leaf, message='(value error) ' + str(e))
660@ErrorFinder.register_rule(value='*')
661class _StarCheck(SyntaxRule):
662 message = "named arguments must follow bare *"
664 def is_issue(self, leaf):
665 params = leaf.parent
666 if params.type == 'parameters' and params:
667 after = params.children[params.children.index(leaf) + 1:]
668 after = [child for child in after
669 if child not in (',', ')') and not child.star_count]
670 return len(after) == 0
673@ErrorFinder.register_rule(value='**')
674class _StarStarCheck(SyntaxRule):
675 # e.g. {**{} for a in [1]}
676 # TODO this should probably get a better end_pos including
677 # the next sibling of leaf.
678 message = "dict unpacking cannot be used in dict comprehension"
680 def is_issue(self, leaf):
681 if leaf.parent.type == 'dictorsetmaker':
682 comp_for = leaf.get_next_sibling().get_next_sibling()
683 return comp_for is not None and comp_for.type in _COMP_FOR_TYPES
686@ErrorFinder.register_rule(value='yield')
687@ErrorFinder.register_rule(value='return')
688class _ReturnAndYieldChecks(SyntaxRule):
689 message = "'return' with value in async generator"
690 message_async_yield = "'yield' inside async function"
692 def get_node(self, leaf):
693 return leaf.parent
695 def is_issue(self, leaf):
696 if self._normalizer.context.node.type != 'funcdef':
697 self.add_issue(self.get_node(leaf), message="'%s' outside function" % leaf.value)
698 elif self._normalizer.context.is_async_funcdef() \
699 and any(self._normalizer.context.node.iter_yield_exprs()):
700 if leaf.value == 'return' and leaf.parent.type == 'return_stmt':
701 return True
704@ErrorFinder.register_rule(type='strings')
705class _BytesAndStringMix(SyntaxRule):
706 # e.g. 's' b''
707 message = "cannot mix bytes and nonbytes literals"
709 def _is_bytes_literal(self, string):
710 if string.type == 'fstring':
711 return False
712 return 'b' in string.string_prefix.lower()
714 def is_issue(self, node):
715 first = node.children[0]
716 first_is_bytes = self._is_bytes_literal(first)
717 for string in node.children[1:]:
718 if first_is_bytes != self._is_bytes_literal(string):
719 return True
722@ErrorFinder.register_rule(type='import_as_names')
723class _TrailingImportComma(SyntaxRule):
724 # e.g. from foo import a,
725 message = "trailing comma not allowed without surrounding parentheses"
727 def is_issue(self, node):
728 if node.children[-1] == ',' and node.parent.children[-1] != ')':
729 return True
732@ErrorFinder.register_rule(type='import_from')
733class _ImportStarInFunction(SyntaxRule):
734 message = "import * only allowed at module level"
736 def is_issue(self, node):
737 return node.is_star_import() and self._normalizer.context.parent_context is not None
740@ErrorFinder.register_rule(type='import_from')
741class _FutureImportRule(SyntaxRule):
742 message = "from __future__ imports must occur at the beginning of the file"
744 def is_issue(self, node):
745 if _is_future_import(node):
746 if not _is_future_import_first(node):
747 return True
749 for from_name, future_name in node.get_paths():
750 name = future_name.value
751 allowed_futures = list(ALLOWED_FUTURES)
752 if self._normalizer.version >= (3, 7):
753 allowed_futures.append('annotations')
754 if name == 'braces':
755 self.add_issue(node, message="not a chance")
756 elif name == 'barry_as_FLUFL':
757 m = "Seriously I'm not implementing this :) ~ Dave"
758 self.add_issue(node, message=m)
759 elif name not in allowed_futures:
760 message = "future feature %s is not defined" % name
761 self.add_issue(node, message=message)
764@ErrorFinder.register_rule(type='star_expr')
765class _StarExprRule(SyntaxRule):
766 message_iterable_unpacking = "iterable unpacking cannot be used in comprehension"
768 def is_issue(self, node):
769 def check_delete_starred(node):
770 while node.parent is not None:
771 node = node.parent
772 if node.type == 'del_stmt':
773 return True
774 if node.type not in (*_STAR_EXPR_PARENTS, 'atom'):
775 return False
776 return False
778 if self._normalizer.version >= (3, 9):
779 ancestor = node.parent
780 else:
781 ancestor = _skip_parens_bottom_up(node)
782 # starred expression not in tuple/list/set
783 if ancestor.type not in (*_STAR_EXPR_PARENTS, 'dictorsetmaker') \
784 and not (ancestor.type == 'atom' and ancestor.children[0] != '('):
785 self.add_issue(node, message="can't use starred expression here")
786 return
788 if check_delete_starred(node):
789 if self._normalizer.version >= (3, 9):
790 self.add_issue(node, message="cannot delete starred")
791 else:
792 self.add_issue(node, message="can't use starred expression here")
793 return
795 if node.parent.type == 'testlist_comp':
796 # [*[] for a in [1]]
797 if node.parent.children[1].type in _COMP_FOR_TYPES:
798 self.add_issue(node, message=self.message_iterable_unpacking)
801@ErrorFinder.register_rule(types=_STAR_EXPR_PARENTS)
802class _StarExprParentRule(SyntaxRule):
803 def is_issue(self, node):
804 def is_definition(node, ancestor):
805 if ancestor is None:
806 return False
808 type_ = ancestor.type
809 if type_ == 'trailer':
810 return False
812 if type_ == 'expr_stmt':
813 return node.start_pos < ancestor.children[-1].start_pos
815 return is_definition(node, ancestor.parent)
817 if is_definition(node, node.parent):
818 args = [c for c in node.children if c != ',']
819 starred = [c for c in args if c.type == 'star_expr']
820 if len(starred) > 1:
821 if self._normalizer.version < (3, 9):
822 message = "two starred expressions in assignment"
823 else:
824 message = "multiple starred expressions in assignment"
825 self.add_issue(starred[1], message=message)
826 elif starred:
827 count = args.index(starred[0])
828 if count >= 256:
829 message = "too many expressions in star-unpacking assignment"
830 self.add_issue(starred[0], message=message)
833@ErrorFinder.register_rule(type='annassign')
834class _AnnotatorRule(SyntaxRule):
835 # True: int
836 # {}: float
837 message = "illegal target for annotation"
839 def get_node(self, node):
840 return node.parent
842 def is_issue(self, node):
843 type_ = None
844 lhs = node.parent.children[0]
845 lhs = _remove_parens(lhs)
846 try:
847 children = lhs.children
848 except AttributeError:
849 pass
850 else:
851 if ',' in children or lhs.type == 'atom' and children[0] == '(':
852 type_ = 'tuple'
853 elif lhs.type == 'atom' and children[0] == '[':
854 type_ = 'list'
855 trailer = children[-1]
857 if type_ is None:
858 if not (lhs.type == 'name'
859 # subscript/attributes are allowed
860 or lhs.type in ('atom_expr', 'power')
861 and trailer.type == 'trailer'
862 and trailer.children[0] != '('):
863 return True
864 else:
865 # x, y: str
866 message = "only single target (not %s) can be annotated"
867 self.add_issue(lhs.parent, message=message % type_)
870@ErrorFinder.register_rule(type='argument')
871class _ArgumentRule(SyntaxRule):
872 def is_issue(self, node):
873 first = node.children[0]
874 if self._normalizer.version < (3, 8):
875 # a((b)=c) is valid in <3.8
876 first = _remove_parens(first)
877 if node.children[1] == '=' and first.type != 'name':
878 if first.type == 'lambdef':
879 # f(lambda: 1=1)
880 if self._normalizer.version < (3, 8):
881 message = "lambda cannot contain assignment"
882 else:
883 message = 'expression cannot contain assignment, perhaps you meant "=="?'
884 else:
885 # f(+x=1)
886 if self._normalizer.version < (3, 8):
887 message = "keyword can't be an expression"
888 else:
889 message = 'expression cannot contain assignment, perhaps you meant "=="?'
890 self.add_issue(first, message=message)
892 if _is_argument_comprehension(node) and node.parent.type == 'classdef':
893 self.add_issue(node, message='invalid syntax')
896@ErrorFinder.register_rule(type='nonlocal_stmt')
897class _NonlocalModuleLevelRule(SyntaxRule):
898 message = "nonlocal declaration not allowed at module level"
900 def is_issue(self, node):
901 return self._normalizer.context.parent_context is None
904@ErrorFinder.register_rule(type='arglist')
905class _ArglistRule(SyntaxRule):
906 @property
907 def message(self):
908 if self._normalizer.version < (3, 7):
909 return "Generator expression must be parenthesized if not sole argument"
910 else:
911 return "Generator expression must be parenthesized"
913 def is_issue(self, node):
914 arg_set = set()
915 kw_only = False
916 kw_unpacking_only = False
917 for argument in node.children:
918 if argument == ',':
919 continue
921 if argument.type == 'argument':
922 first = argument.children[0]
923 if _is_argument_comprehension(argument) and len(node.children) >= 2:
924 # a(a, b for b in c)
925 return True
927 if first in ('*', '**'):
928 if first == '*':
929 if kw_unpacking_only:
930 # foo(**kwargs, *args)
931 message = "iterable argument unpacking " \
932 "follows keyword argument unpacking"
933 self.add_issue(argument, message=message)
934 else:
935 kw_unpacking_only = True
936 else: # Is a keyword argument.
937 kw_only = True
938 if first.type == 'name':
939 if first.value in arg_set:
940 # f(x=1, x=2)
941 message = "keyword argument repeated"
942 if self._normalizer.version >= (3, 9):
943 message += ": {}".format(first.value)
944 self.add_issue(first, message=message)
945 else:
946 arg_set.add(first.value)
947 else:
948 if kw_unpacking_only:
949 # f(**x, y)
950 message = "positional argument follows keyword argument unpacking"
951 self.add_issue(argument, message=message)
952 elif kw_only:
953 # f(x=2, y)
954 message = "positional argument follows keyword argument"
955 self.add_issue(argument, message=message)
958@ErrorFinder.register_rule(type='parameters')
959@ErrorFinder.register_rule(type='lambdef')
960class _ParameterRule(SyntaxRule):
961 # def f(x=3, y): pass
962 message = "non-default argument follows default argument"
964 def is_issue(self, node):
965 param_names = set()
966 default_only = False
967 star_seen = False
968 for p in _iter_params(node):
969 if p.type == 'operator':
970 if p.value == '*':
971 star_seen = True
972 default_only = False
973 continue
975 if p.name.value in param_names:
976 message = "duplicate argument '%s' in function definition"
977 self.add_issue(p.name, message=message % p.name.value)
978 param_names.add(p.name.value)
980 if not star_seen:
981 if p.default is None and not p.star_count:
982 if default_only:
983 return True
984 elif p.star_count:
985 star_seen = True
986 default_only = False
987 else:
988 default_only = True
991@ErrorFinder.register_rule(type='try_stmt')
992class _TryStmtRule(SyntaxRule):
993 message = "default 'except:' must be last"
995 def is_issue(self, try_stmt):
996 default_except = None
997 for except_clause in try_stmt.children[3::3]:
998 if except_clause in ('else', 'finally'):
999 break
1000 if except_clause == 'except':
1001 default_except = except_clause
1002 elif default_except is not None:
1003 self.add_issue(default_except, message=self.message)
1006@ErrorFinder.register_rule(type='fstring')
1007class _FStringRule(SyntaxRule):
1008 _fstring_grammar = None
1009 message_expr = "f-string expression part cannot include a backslash"
1010 message_nested = "f-string: expressions nested too deeply"
1011 message_conversion = "f-string: invalid conversion character: expected 's', 'r', or 'a'"
1013 def _check_format_spec(self, format_spec, depth):
1014 self._check_fstring_contents(format_spec.children[1:], depth)
1016 def _check_fstring_expr(self, fstring_expr, depth):
1017 if depth >= 2:
1018 self.add_issue(fstring_expr, message=self.message_nested)
1020 expr = fstring_expr.children[1]
1021 if '\\' in expr.get_code():
1022 self.add_issue(expr, message=self.message_expr)
1024 children_2 = fstring_expr.children[2]
1025 if children_2.type == 'operator' and children_2.value == '=':
1026 conversion = fstring_expr.children[3]
1027 else:
1028 conversion = children_2
1029 if conversion.type == 'fstring_conversion':
1030 name = conversion.children[1]
1031 if name.value not in ('s', 'r', 'a'):
1032 self.add_issue(name, message=self.message_conversion)
1034 format_spec = fstring_expr.children[-2]
1035 if format_spec.type == 'fstring_format_spec':
1036 self._check_format_spec(format_spec, depth + 1)
1038 def is_issue(self, fstring):
1039 self._check_fstring_contents(fstring.children[1:-1])
1041 def _check_fstring_contents(self, children, depth=0):
1042 for fstring_content in children:
1043 if fstring_content.type == 'fstring_expr':
1044 self._check_fstring_expr(fstring_content, depth)
1047class _CheckAssignmentRule(SyntaxRule):
1048 def _check_assignment(self, node, is_deletion=False, is_namedexpr=False, is_aug_assign=False):
1049 error = None
1050 type_ = node.type
1051 if type_ == 'lambdef':
1052 error = 'lambda'
1053 elif type_ == 'atom':
1054 first, second = node.children[:2]
1055 error = _get_comprehension_type(node)
1056 if error is None:
1057 if second.type == 'dictorsetmaker':
1058 if self._normalizer.version < (3, 8):
1059 error = 'literal'
1060 else:
1061 if second.children[1] == ':':
1062 if self._normalizer.version < (3, 10):
1063 error = 'dict display'
1064 else:
1065 error = 'dict literal'
1066 else:
1067 error = 'set display'
1068 elif first == "{" and second == "}":
1069 if self._normalizer.version < (3, 8):
1070 error = 'literal'
1071 else:
1072 if self._normalizer.version < (3, 10):
1073 error = "dict display"
1074 else:
1075 error = "dict literal"
1076 elif first == "{" and len(node.children) > 2:
1077 if self._normalizer.version < (3, 8):
1078 error = 'literal'
1079 else:
1080 error = "set display"
1081 elif first in ('(', '['):
1082 if second.type == 'yield_expr':
1083 error = 'yield expression'
1084 elif second.type == 'testlist_comp':
1085 # ([a, b] := [1, 2])
1086 # ((a, b) := [1, 2])
1087 if is_namedexpr:
1088 if first == '(':
1089 error = 'tuple'
1090 elif first == '[':
1091 error = 'list'
1093 # This is not a comprehension, they were handled
1094 # further above.
1095 for child in second.children[::2]:
1096 self._check_assignment(child, is_deletion, is_namedexpr, is_aug_assign)
1097 else: # Everything handled, must be useless brackets.
1098 self._check_assignment(second, is_deletion, is_namedexpr, is_aug_assign)
1099 elif type_ == 'keyword':
1100 if node.value == "yield":
1101 error = "yield expression"
1102 elif self._normalizer.version < (3, 8):
1103 error = 'keyword'
1104 else:
1105 error = str(node.value)
1106 elif type_ == 'operator':
1107 if node.value == '...':
1108 if self._normalizer.version < (3, 10):
1109 error = 'Ellipsis'
1110 else:
1111 error = 'ellipsis'
1112 elif type_ == 'comparison':
1113 error = 'comparison'
1114 elif type_ in ('string', 'number', 'strings'):
1115 error = 'literal'
1116 elif type_ == 'yield_expr':
1117 # This one seems to be a slightly different warning in Python.
1118 message = 'assignment to yield expression not possible'
1119 self.add_issue(node, message=message)
1120 elif type_ == 'test':
1121 error = 'conditional expression'
1122 elif type_ in ('atom_expr', 'power'):
1123 if node.children[0] == 'await':
1124 error = 'await expression'
1125 elif node.children[-2] == '**':
1126 if self._normalizer.version < (3, 10):
1127 error = 'operator'
1128 else:
1129 error = 'expression'
1130 else:
1131 # Has a trailer
1132 trailer = node.children[-1]
1133 assert trailer.type == 'trailer'
1134 if trailer.children[0] == '(':
1135 error = 'function call'
1136 elif is_namedexpr and trailer.children[0] == '[':
1137 error = 'subscript'
1138 elif is_namedexpr and trailer.children[0] == '.':
1139 error = 'attribute'
1140 elif type_ == "fstring":
1141 if self._normalizer.version < (3, 8):
1142 error = 'literal'
1143 else:
1144 error = "f-string expression"
1145 elif type_ in ('testlist_star_expr', 'exprlist', 'testlist'):
1146 for child in node.children[::2]:
1147 self._check_assignment(child, is_deletion, is_namedexpr, is_aug_assign)
1148 elif ('expr' in type_ and type_ != 'star_expr' # is a substring
1149 or '_test' in type_
1150 or type_ in ('term', 'factor')):
1151 if self._normalizer.version < (3, 10):
1152 error = 'operator'
1153 else:
1154 error = 'expression'
1155 elif type_ == "star_expr":
1156 if is_deletion:
1157 if self._normalizer.version >= (3, 9):
1158 error = "starred"
1159 else:
1160 self.add_issue(node, message="can't use starred expression here")
1161 else:
1162 if self._normalizer.version >= (3, 9):
1163 ancestor = node.parent
1164 else:
1165 ancestor = _skip_parens_bottom_up(node)
1166 if ancestor.type not in _STAR_EXPR_PARENTS and not is_aug_assign \
1167 and not (ancestor.type == 'atom' and ancestor.children[0] == '['):
1168 message = "starred assignment target must be in a list or tuple"
1169 self.add_issue(node, message=message)
1171 self._check_assignment(node.children[1])
1173 if error is not None:
1174 if is_namedexpr:
1175 message = 'cannot use assignment expressions with %s' % error
1176 else:
1177 cannot = "can't" if self._normalizer.version < (3, 8) else "cannot"
1178 message = ' '.join([cannot, "delete" if is_deletion else "assign to", error])
1179 self.add_issue(node, message=message)
1182@ErrorFinder.register_rule(type='sync_comp_for')
1183class _CompForRule(_CheckAssignmentRule):
1184 message = "asynchronous comprehension outside of an asynchronous function"
1186 def is_issue(self, node):
1187 expr_list = node.children[1]
1188 if expr_list.type != 'expr_list': # Already handled.
1189 self._check_assignment(expr_list)
1191 return node.parent.children[0] == 'async' \
1192 and not self._normalizer.context.is_async_funcdef()
1195@ErrorFinder.register_rule(type='expr_stmt')
1196class _ExprStmtRule(_CheckAssignmentRule):
1197 message = "illegal expression for augmented assignment"
1198 extended_message = "'{target}' is an " + message
1200 def is_issue(self, node):
1201 augassign = node.children[1]
1202 is_aug_assign = augassign != '=' and augassign.type != 'annassign'
1204 if self._normalizer.version <= (3, 8) or not is_aug_assign:
1205 for before_equal in node.children[:-2:2]:
1206 self._check_assignment(before_equal, is_aug_assign=is_aug_assign)
1208 if is_aug_assign:
1209 target = _remove_parens(node.children[0])
1210 # a, a[b], a.b
1212 if target.type == "name" or (
1213 target.type in ("atom_expr", "power")
1214 and target.children[1].type == "trailer"
1215 and target.children[-1].children[0] != "("
1216 ):
1217 return False
1219 if self._normalizer.version <= (3, 8):
1220 return True
1221 else:
1222 self.add_issue(
1223 node,
1224 message=self.extended_message.format(
1225 target=_get_rhs_name(node.children[0], self._normalizer.version)
1226 ),
1227 )
1230@ErrorFinder.register_rule(type='with_item')
1231class _WithItemRule(_CheckAssignmentRule):
1232 def is_issue(self, with_item):
1233 self._check_assignment(with_item.children[2])
1236@ErrorFinder.register_rule(type='del_stmt')
1237class _DelStmtRule(_CheckAssignmentRule):
1238 def is_issue(self, del_stmt):
1239 child = del_stmt.children[1]
1241 if child.type != 'expr_list': # Already handled.
1242 self._check_assignment(child, is_deletion=True)
1245@ErrorFinder.register_rule(type='expr_list')
1246class _ExprListRule(_CheckAssignmentRule):
1247 def is_issue(self, expr_list):
1248 for expr in expr_list.children[::2]:
1249 self._check_assignment(expr)
1252@ErrorFinder.register_rule(type='for_stmt')
1253class _ForStmtRule(_CheckAssignmentRule):
1254 def is_issue(self, for_stmt):
1255 # Some of the nodes here are already used, so no else if
1256 expr_list = for_stmt.children[1]
1257 if expr_list.type != 'expr_list': # Already handled.
1258 self._check_assignment(expr_list)
1261@ErrorFinder.register_rule(type='namedexpr_test')
1262class _NamedExprRule(_CheckAssignmentRule):
1263 # namedexpr_test: test [':=' test]
1265 def is_issue(self, namedexpr_test):
1266 # assigned name
1267 first = namedexpr_test.children[0]
1269 def search_namedexpr_in_comp_for(node):
1270 while True:
1271 parent = node.parent
1272 if parent is None:
1273 return parent
1274 if parent.type == 'sync_comp_for' and parent.children[3] == node:
1275 return parent
1276 node = parent
1278 if search_namedexpr_in_comp_for(namedexpr_test):
1279 # [i+1 for i in (i := range(5))]
1280 # [i+1 for i in (j := range(5))]
1281 # [i+1 for i in (lambda: (j := range(5)))()]
1282 message = 'assignment expression cannot be used in a comprehension iterable expression'
1283 self.add_issue(namedexpr_test, message=message)
1285 # defined names
1286 exprlist = list()
1288 def process_comp_for(comp_for):
1289 if comp_for.type == 'sync_comp_for':
1290 comp = comp_for
1291 elif comp_for.type == 'comp_for':
1292 comp = comp_for.children[1]
1293 exprlist.extend(_get_for_stmt_definition_exprs(comp))
1295 def search_all_comp_ancestors(node):
1296 has_ancestors = False
1297 while True:
1298 node = node.search_ancestor('testlist_comp', 'dictorsetmaker')
1299 if node is None:
1300 break
1301 for child in node.children:
1302 if child.type in _COMP_FOR_TYPES:
1303 process_comp_for(child)
1304 has_ancestors = True
1305 break
1306 return has_ancestors
1308 # check assignment expressions in comprehensions
1309 search_all = search_all_comp_ancestors(namedexpr_test)
1310 if search_all:
1311 if self._normalizer.context.node.type == 'classdef':
1312 message = 'assignment expression within a comprehension ' \
1313 'cannot be used in a class body'
1314 self.add_issue(namedexpr_test, message=message)
1316 namelist = [expr.value for expr in exprlist if expr.type == 'name']
1317 if first.type == 'name' and first.value in namelist:
1318 # [i := 0 for i, j in range(5)]
1319 # [[(i := i) for j in range(5)] for i in range(5)]
1320 # [i for i, j in range(5) if True or (i := 1)]
1321 # [False and (i := 0) for i, j in range(5)]
1322 message = 'assignment expression cannot rebind ' \
1323 'comprehension iteration variable %r' % first.value
1324 self.add_issue(namedexpr_test, message=message)
1326 self._check_assignment(first, is_namedexpr=True)