""" Functions evaluating the syntax tree. """ import copy from parso.python import tree from jedi._compatibility import force_unicode, unicode from jedi import debug from jedi import parser_utils from jedi.evaluate.base_context import ContextSet, NO_CONTEXTS, ContextualizedNode, \ ContextualizedName, iterator_to_context_set, iterate_contexts from jedi.evaluate.lazy_context import LazyTreeContext from jedi.evaluate import compiled from jedi.evaluate import recursion from jedi.evaluate import helpers from jedi.evaluate import analysis from jedi.evaluate import imports from jedi.evaluate import arguments from jedi.evaluate.context import ClassContext, FunctionContext from jedi.evaluate.context import iterable from jedi.evaluate.context import TreeInstance from jedi.evaluate.finder import NameFinder from jedi.evaluate.helpers import is_string, is_literal, is_number from jedi.evaluate.compiled.access import COMPARISON_OPERATORS from jedi.evaluate.cache import evaluator_method_cache from jedi.evaluate.gradual.stub_context import VersionInfo from jedi.evaluate.gradual import annotation from jedi.evaluate.context.decorator import Decoratee from jedi.plugins import plugin_manager def _limit_context_infers(func): """ This is for now the way how we limit type inference going wild. There are other ways to ensure recursion limits as well. This is mostly necessary because of instance (self) access that can be quite tricky to limit. I'm still not sure this is the way to go, but it looks okay for now and we can still go anther way in the future. Tests are there. ~ dave """ def wrapper(context, *args, **kwargs): n = context.tree_node evaluator = context.evaluator try: evaluator.inferred_element_counts[n] += 1 if evaluator.inferred_element_counts[n] > 300: debug.warning('In context %s there were too many inferences.', n) return NO_CONTEXTS except KeyError: evaluator.inferred_element_counts[n] = 1 return func(context, *args, **kwargs) return wrapper def _py__stop_iteration_returns(generators): results = NO_CONTEXTS for generator in generators: try: method = generator.py__stop_iteration_returns except AttributeError: debug.warning('%s is not actually a generator', generator) else: results |= method() return results @debug.increase_indent @_limit_context_infers def eval_node(context, element): debug.dbg('eval_node %s@%s in %s', element, element.start_pos, context) evaluator = context.evaluator typ = element.type if typ in ('name', 'number', 'string', 'atom', 'strings', 'keyword', 'fstring'): return eval_atom(context, element) elif typ == 'lambdef': return ContextSet([FunctionContext.from_context(context, element)]) elif typ == 'expr_stmt': return eval_expr_stmt(context, element) elif typ in ('power', 'atom_expr'): first_child = element.children[0] children = element.children[1:] had_await = False if first_child.type == 'keyword' and first_child.value == 'await': had_await = True first_child = children.pop(0) context_set = context.eval_node(first_child) for (i, trailer) in enumerate(children): if trailer == '**': # has a power operation. right = context.eval_node(children[i + 1]) context_set = _eval_comparison( evaluator, context, context_set, trailer, right ) break context_set = eval_trailer(context, context_set, trailer) if had_await: return context_set.py__await__().py__stop_iteration_returns() return context_set elif typ in ('testlist_star_expr', 'testlist',): # The implicit tuple in statements. return ContextSet([iterable.SequenceLiteralContext(evaluator, context, element)]) elif typ in ('not_test', 'factor'): context_set = context.eval_node(element.children[-1]) for operator in element.children[:-1]: context_set = eval_factor(context_set, operator) return context_set elif typ == 'test': # `x if foo else y` case. return (context.eval_node(element.children[0]) | context.eval_node(element.children[-1])) elif typ == 'operator': # Must be an ellipsis, other operators are not evaluated. # In Python 2 ellipsis is coded as three single dot tokens, not # as one token 3 dot token. if element.value not in ('.', '...'): origin = element.parent raise AssertionError("unhandled operator %s in %s " % (repr(element.value), origin)) return ContextSet([compiled.builtin_from_name(evaluator, u'Ellipsis')]) elif typ == 'dotted_name': context_set = eval_atom(context, element.children[0]) for next_name in element.children[2::2]: # TODO add search_global=True? context_set = context_set.py__getattribute__(next_name, name_context=context) return context_set elif typ == 'eval_input': return eval_node(context, element.children[0]) elif typ == 'annassign': return annotation.eval_annotation(context, element.children[1]) \ .execute_annotation() elif typ == 'yield_expr': if len(element.children) and element.children[1].type == 'yield_arg': # Implies that it's a yield from. element = element.children[1].children[1] generators = context.eval_node(element) \ .py__getattribute__('__iter__').execute_evaluated() return generators.py__stop_iteration_returns() # Generator.send() is not implemented. return NO_CONTEXTS elif typ == 'namedexpr_test': return eval_node(context, element.children[2]) else: return eval_or_test(context, element) def eval_trailer(context, atom_contexts, trailer): trailer_op, node = trailer.children[:2] if node == ')': # `arglist` is optional. node = None if trailer_op == '[': trailer_op, node, _ = trailer.children return atom_contexts.get_item( eval_subscript_list(context.evaluator, context, node), ContextualizedNode(context, trailer) ) else: debug.dbg('eval_trailer: %s in %s', trailer, atom_contexts) if trailer_op == '.': return atom_contexts.py__getattribute__( name_context=context, name_or_str=node ) else: assert trailer_op == '(', 'trailer_op is actually %s' % trailer_op args = arguments.TreeArguments(context.evaluator, context, node, trailer) return atom_contexts.execute(args) def eval_atom(context, atom): """ Basically to process ``atom`` nodes. The parser sometimes doesn't generate the node (because it has just one child). In that case an atom might be a name or a literal as well. """ if atom.type == 'name': if atom.value in ('True', 'False', 'None'): # Python 2... return ContextSet([compiled.builtin_from_name(context.evaluator, atom.value)]) # This is the first global lookup. stmt = tree.search_ancestor( atom, 'expr_stmt', 'lambdef' ) or atom if stmt.type == 'lambdef': stmt = atom position = stmt.start_pos if _is_annotation_name(atom): # Since Python 3.7 (with from __future__ import annotations), # annotations are essentially strings and can reference objects # that are defined further down in code. Therefore just set the # position to None, so the finder will not try to stop at a certain # position in the module. position = None return context.py__getattribute__( name_or_str=atom, position=position, search_global=True ) elif atom.type == 'keyword': # For False/True/None if atom.value in ('False', 'True', 'None'): return ContextSet([compiled.builtin_from_name(context.evaluator, atom.value)]) elif atom.value == 'print': # print e.g. could be evaluated like this in Python 2.7 return NO_CONTEXTS elif atom.value == 'yield': # Contrary to yield from, yield can just appear alone to return a # value when used with `.send()`. return NO_CONTEXTS assert False, 'Cannot evaluate the keyword %s' % atom elif isinstance(atom, tree.Literal): string = context.evaluator.compiled_subprocess.safe_literal_eval(atom.value) return ContextSet([compiled.create_simple_object(context.evaluator, string)]) elif atom.type == 'strings': # Will be multiple string. context_set = eval_atom(context, atom.children[0]) for string in atom.children[1:]: right = eval_atom(context, string) context_set = _eval_comparison(context.evaluator, context, context_set, u'+', right) return context_set elif atom.type == 'fstring': return compiled.get_string_context_set(context.evaluator) else: c = atom.children # Parentheses without commas are not tuples. if c[0] == '(' and not len(c) == 2 \ and not(c[1].type == 'testlist_comp' and len(c[1].children) > 1): return context.eval_node(c[1]) try: comp_for = c[1].children[1] except (IndexError, AttributeError): pass else: if comp_for == ':': # Dict comprehensions have a colon at the 3rd index. try: comp_for = c[1].children[3] except IndexError: pass if comp_for.type in ('comp_for', 'sync_comp_for'): return ContextSet([iterable.comprehension_from_atom( context.evaluator, context, atom )]) # It's a dict/list/tuple literal. array_node = c[1] try: array_node_c = array_node.children except AttributeError: array_node_c = [] if c[0] == '{' and (array_node == '}' or ':' in array_node_c or '**' in array_node_c): context = iterable.DictLiteralContext(context.evaluator, context, atom) else: context = iterable.SequenceLiteralContext(context.evaluator, context, atom) return ContextSet([context]) @_limit_context_infers def eval_expr_stmt(context, stmt, seek_name=None): with recursion.execution_allowed(context.evaluator, stmt) as allowed: # Here we allow list/set to recurse under certain conditions. To make # it possible to resolve stuff like list(set(list(x))), this is # necessary. if not allowed and context.get_root_context() == context.evaluator.builtins_module: try: instance = context.var_args.instance except AttributeError: pass else: if instance.name.string_name in ('list', 'set'): c = instance.get_first_non_keyword_argument_contexts() if instance not in c: allowed = True if allowed: return _eval_expr_stmt(context, stmt, seek_name) return NO_CONTEXTS @debug.increase_indent def _eval_expr_stmt(context, stmt, seek_name=None): """ The starting point of the completion. A statement always owns a call list, which are the calls, that a statement does. In case multiple names are defined in the statement, `seek_name` returns the result for this name. :param stmt: A `tree.ExprStmt`. """ debug.dbg('eval_expr_stmt %s (%s)', stmt, seek_name) rhs = stmt.get_rhs() context_set = context.eval_node(rhs) if seek_name: c_node = ContextualizedName(context, seek_name) context_set = check_tuple_assignments(context.evaluator, c_node, context_set) first_operator = next(stmt.yield_operators(), None) if first_operator not in ('=', None) and first_operator.type == 'operator': # `=` is always the last character in aug assignments -> -1 operator = copy.copy(first_operator) operator.value = operator.value[:-1] name = stmt.get_defined_names()[0].value left = context.py__getattribute__( name, position=stmt.start_pos, search_global=True) for_stmt = tree.search_ancestor(stmt, 'for_stmt') if for_stmt is not None and for_stmt.type == 'for_stmt' and context_set \ and parser_utils.for_stmt_defines_one_name(for_stmt): # Iterate through result and add the values, that's possible # only in for loops without clutter, because they are # predictable. Also only do it, if the variable is not a tuple. node = for_stmt.get_testlist() cn = ContextualizedNode(context, node) ordered = list(cn.infer().iterate(cn)) for lazy_context in ordered: dct = {for_stmt.children[1].value: lazy_context.infer()} with helpers.predefine_names(context, for_stmt, dct): t = context.eval_node(rhs) left = _eval_comparison(context.evaluator, context, left, operator, t) context_set = left else: context_set = _eval_comparison(context.evaluator, context, left, operator, context_set) debug.dbg('eval_expr_stmt result %s', context_set) return context_set def eval_or_test(context, or_test): iterator = iter(or_test.children) types = context.eval_node(next(iterator)) for operator in iterator: right = next(iterator) if operator.type == 'comp_op': # not in / is not operator = ' '.join(c.value for c in operator.children) # handle lazy evaluation of and/or here. if operator in ('and', 'or'): left_bools = set(left.py__bool__() for left in types) if left_bools == {True}: if operator == 'and': types = context.eval_node(right) elif left_bools == {False}: if operator != 'and': types = context.eval_node(right) # Otherwise continue, because of uncertainty. else: types = _eval_comparison(context.evaluator, context, types, operator, context.eval_node(right)) debug.dbg('eval_or_test types %s', types) return types @iterator_to_context_set def eval_factor(context_set, operator): """ Calculates `+`, `-`, `~` and `not` prefixes. """ for context in context_set: if operator == '-': if is_number(context): yield context.negate() elif operator == 'not': value = context.py__bool__() if value is None: # Uncertainty. return yield compiled.create_simple_object(context.evaluator, not value) else: yield context def _literals_to_types(evaluator, result): # Changes literals ('a', 1, 1.0, etc) to its type instances (str(), # int(), float(), etc). new_result = NO_CONTEXTS for typ in result: if is_literal(typ): # Literals are only valid as long as the operations are # correct. Otherwise add a value-free instance. cls = compiled.builtin_from_name(evaluator, typ.name.string_name) new_result |= cls.execute_evaluated() else: new_result |= ContextSet([typ]) return new_result def _eval_comparison(evaluator, context, left_contexts, operator, right_contexts): if not left_contexts or not right_contexts: # illegal slices e.g. cause left/right_result to be None result = (left_contexts or NO_CONTEXTS) | (right_contexts or NO_CONTEXTS) return _literals_to_types(evaluator, result) else: # I don't think there's a reasonable chance that a string # operation is still correct, once we pass something like six # objects. if len(left_contexts) * len(right_contexts) > 6: return _literals_to_types(evaluator, left_contexts | right_contexts) else: return ContextSet.from_sets( _eval_comparison_part(evaluator, context, left, operator, right) for left in left_contexts for right in right_contexts ) def _is_annotation_name(name): ancestor = tree.search_ancestor(name, 'param', 'funcdef', 'expr_stmt') if ancestor is None: return False if ancestor.type in ('param', 'funcdef'): ann = ancestor.annotation if ann is not None: return ann.start_pos <= name.start_pos < ann.end_pos elif ancestor.type == 'expr_stmt': c = ancestor.children if len(c) > 1 and c[1].type == 'annassign': return c[1].start_pos <= name.start_pos < c[1].end_pos return False def _is_tuple(context): return isinstance(context, iterable.Sequence) and context.array_type == 'tuple' def _is_list(context): return isinstance(context, iterable.Sequence) and context.array_type == 'list' def _bool_to_context(evaluator, bool_): return compiled.builtin_from_name(evaluator, force_unicode(str(bool_))) def _get_tuple_ints(context): if not isinstance(context, iterable.SequenceLiteralContext): return None numbers = [] for lazy_context in context.py__iter__(): if not isinstance(lazy_context, LazyTreeContext): return None node = lazy_context.data if node.type != 'number': return None try: numbers.append(int(node.value)) except ValueError: return None return numbers def _eval_comparison_part(evaluator, context, left, operator, right): l_is_num = is_number(left) r_is_num = is_number(right) if isinstance(operator, unicode): str_operator = operator else: str_operator = force_unicode(str(operator.value)) if str_operator == '*': # for iterables, ignore * operations if isinstance(left, iterable.Sequence) or is_string(left): return ContextSet([left]) elif isinstance(right, iterable.Sequence) or is_string(right): return ContextSet([right]) elif str_operator == '+': if l_is_num and r_is_num or is_string(left) and is_string(right): return ContextSet([left.execute_operation(right, str_operator)]) elif _is_tuple(left) and _is_tuple(right) or _is_list(left) and _is_list(right): return ContextSet([iterable.MergedArray(evaluator, (left, right))]) elif str_operator == '-': if l_is_num and r_is_num: return ContextSet([left.execute_operation(right, str_operator)]) elif str_operator == '%': # With strings and numbers the left type typically remains. Except for # `int() % float()`. return ContextSet([left]) elif str_operator in COMPARISON_OPERATORS: if left.is_compiled() and right.is_compiled(): # Possible, because the return is not an option. Just compare. try: return ContextSet([left.execute_operation(right, str_operator)]) except TypeError: # Could be True or False. pass else: if str_operator in ('is', '!=', '==', 'is not'): operation = COMPARISON_OPERATORS[str_operator] bool_ = operation(left, right) return ContextSet([_bool_to_context(evaluator, bool_)]) if isinstance(left, VersionInfo): version_info = _get_tuple_ints(right) if version_info is not None: bool_result = compiled.access.COMPARISON_OPERATORS[operator]( evaluator.environment.version_info, tuple(version_info) ) return ContextSet([_bool_to_context(evaluator, bool_result)]) return ContextSet([_bool_to_context(evaluator, True), _bool_to_context(evaluator, False)]) elif str_operator == 'in': return NO_CONTEXTS def check(obj): """Checks if a Jedi object is either a float or an int.""" return isinstance(obj, TreeInstance) and \ obj.name.string_name in ('int', 'float') # Static analysis, one is a number, the other one is not. if str_operator in ('+', '-') and l_is_num != r_is_num \ and not (check(left) or check(right)): message = "TypeError: unsupported operand type(s) for +: %s and %s" analysis.add(context, 'type-error-operation', operator, message % (left, right)) result = ContextSet([left, right]) debug.dbg('Used operator %s resulting in %s', operator, result) return result def _remove_statements(evaluator, context, stmt, name): """ This is the part where statements are being stripped. Due to lazy evaluation, statements like a = func; b = a; b() have to be evaluated. """ pep0484_contexts = \ annotation.find_type_from_comment_hint_assign(context, stmt, name) if pep0484_contexts: return pep0484_contexts return eval_expr_stmt(context, stmt, seek_name=name) @plugin_manager.decorate() def tree_name_to_contexts(evaluator, context, tree_name): context_set = NO_CONTEXTS module_node = context.get_root_context().tree_node # First check for annotations, like: `foo: int = 3` if module_node is not None: names = module_node.get_used_names().get(tree_name.value, []) for name in names: expr_stmt = name.parent if expr_stmt.type == "expr_stmt" and expr_stmt.children[1].type == "annassign": correct_scope = parser_utils.get_parent_scope(name) == context.tree_node if correct_scope: context_set |= annotation.eval_annotation( context, expr_stmt.children[1].children[1] ).execute_annotation() if context_set: return context_set types = [] node = tree_name.get_definition(import_name_always=True) if node is None: node = tree_name.parent if node.type == 'global_stmt': context = evaluator.create_context(context, tree_name) finder = NameFinder(evaluator, context, context, tree_name.value) filters = finder.get_filters(search_global=True) # For global_stmt lookups, we only need the first possible scope, # which means the function itself. filters = [next(filters)] return finder.find(filters, attribute_lookup=False) elif node.type not in ('import_from', 'import_name'): context = evaluator.create_context(context, tree_name) return eval_atom(context, tree_name) typ = node.type if typ == 'for_stmt': types = annotation.find_type_from_comment_hint_for(context, node, tree_name) if types: return types if typ == 'with_stmt': types = annotation.find_type_from_comment_hint_with(context, node, tree_name) if types: return types if typ in ('for_stmt', 'comp_for', 'sync_comp_for'): try: types = context.predefined_names[node][tree_name.value] except KeyError: cn = ContextualizedNode(context, node.children[3]) for_types = iterate_contexts( cn.infer(), contextualized_node=cn, is_async=node.parent.type == 'async_stmt', ) c_node = ContextualizedName(context, tree_name) types = check_tuple_assignments(evaluator, c_node, for_types) elif typ == 'expr_stmt': types = _remove_statements(evaluator, context, node, tree_name) elif typ == 'with_stmt': context_managers = context.eval_node(node.get_test_node_from_name(tree_name)) enter_methods = context_managers.py__getattribute__(u'__enter__') return enter_methods.execute_evaluated() elif typ in ('import_from', 'import_name'): types = imports.infer_import(context, tree_name) elif typ in ('funcdef', 'classdef'): types = _apply_decorators(context, node) elif typ == 'try_stmt': # TODO an exception can also be a tuple. Check for those. # TODO check for types that are not classes and add it to # the static analysis report. exceptions = context.eval_node(tree_name.get_previous_sibling().get_previous_sibling()) types = exceptions.execute_evaluated() elif node.type == 'param': types = NO_CONTEXTS else: raise ValueError("Should not happen. type: %s" % typ) return types # We don't want to have functions/classes that are created by the same # tree_node. @evaluator_method_cache() def _apply_decorators(context, node): """ Returns the function, that should to be executed in the end. This is also the places where the decorators are processed. """ if node.type == 'classdef': decoratee_context = ClassContext( context.evaluator, parent_context=context, tree_node=node ) else: decoratee_context = FunctionContext.from_context(context, node) initial = values = ContextSet([decoratee_context]) for dec in reversed(node.get_decorators()): debug.dbg('decorator: %s %s', dec, values, color="MAGENTA") with debug.increase_indent_cm(): dec_values = context.eval_node(dec.children[1]) trailer_nodes = dec.children[2:-1] if trailer_nodes: # Create a trailer and evaluate it. trailer = tree.PythonNode('trailer', trailer_nodes) trailer.parent = dec dec_values = eval_trailer(context, dec_values, trailer) if not len(dec_values): code = dec.get_code(include_prefix=False) # For the short future, we don't want to hear about the runtime # decorator in typing that was intentionally omitted. This is not # "correct", but helps with debugging. if code != '@runtime\n': debug.warning('decorator not found: %s on %s', dec, node) return initial values = dec_values.execute(arguments.ValuesArguments([values])) if not len(values): debug.warning('not possible to resolve wrappers found %s', node) return initial debug.dbg('decorator end %s', values, color="MAGENTA") if values != initial: return ContextSet([Decoratee(c, decoratee_context) for c in values]) return values def check_tuple_assignments(evaluator, contextualized_name, context_set): """ Checks if tuples are assigned. """ lazy_context = None for index, node in contextualized_name.assignment_indexes(): cn = ContextualizedNode(contextualized_name.context, node) iterated = context_set.iterate(cn) if isinstance(index, slice): # For no star unpacking is not possible. return NO_CONTEXTS for _ in range(index + 1): try: lazy_context = next(iterated) except StopIteration: # We could do this with the default param in next. But this # would allow this loop to run for a very long time if the # index number is high. Therefore break if the loop is # finished. return NO_CONTEXTS context_set = lazy_context.infer() return context_set def eval_subscript_list(evaluator, context, index): """ Handles slices in subscript nodes. """ if index == ':': # Like array[:] return ContextSet([iterable.Slice(context, None, None, None)]) elif index.type == 'subscript' and not index.children[0] == '.': # subscript basically implies a slice operation, except for Python 2's # Ellipsis. # e.g. array[:3] result = [] for el in index.children: if el == ':': if not result: result.append(None) elif el.type == 'sliceop': if len(el.children) == 2: result.append(el.children[1]) else: result.append(el) result += [None] * (3 - len(result)) return ContextSet([iterable.Slice(context, *result)]) elif index.type == 'subscriptlist': return ContextSet([iterable.SequenceLiteralContext(evaluator, context, index)]) # No slices return context.eval_node(index)