forked from VimPlug/jedi
588 lines
21 KiB
Python
588 lines
21 KiB
Python
"""
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To understand Python on a deeper level, |jedi| needs to understand some of the
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dynamic features of Python, however this probably the most complicated part:
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- Array modifications (e.g. ``list.append``)
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- Parameter completion in functions
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- Flow checks (e.g. ``if isinstance(a, str)`` -> a is a str)
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Array modifications
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*******************
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If the content of an array (``set``/``list``) is wanted somewhere, the current
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module will be checked for appearances of ``arr.append``, ``arr.insert``, etc.
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If the ``arr`` name points to an actual array, the content will be added
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This can be really cpu intensive, as you can imagine. Because |jedi| has to
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follow **every** ``append``. However this works pretty good, because in *slow*
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cases, the recursion detector and other settings will stop this process.
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It is important to note that:
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1. Array modfications work only in the current module
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2. Only Array additions are being checked, ``list.pop``, etc. is being ignored.
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Parameter completion
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********************
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One of the really important features of |jedi| is to have an option to
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understand code like this::
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def foo(bar):
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bar. # completion here
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foo(1)
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There's no doubt wheter bar is an ``int`` or not, but if there's also a call
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like ``foo('str')``, what would happen? Well, we'll just show both. Because
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that's what a human would expect.
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It works as follows:
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- A param is being encountered
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- search for function calls named ``foo``
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- execute these calls and check the injected params. This work with a
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``ParamListener``.
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Flow checks
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***********
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Flow checks are not really mature. There's only a check for ``isinstance``. It
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would check whether a flow has the form of ``if isinstance(a, type_or_tuple)``.
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Unfortunately every other thing is being ignored (e.g. a == '' would be easy to
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check for -> a is a string). There's big potential in these checks.
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"""
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from __future__ import with_statement
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import os
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from jedi import cache
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from jedi.parser import representation as pr
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from jedi import modules
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from jedi import settings
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from jedi import common
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from jedi import debug
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from jedi.parser import fast as fast_parser
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from jedi.evaluate import imports
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from jedi.evaluate.cache import memoize_default
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# This is something like the sys.path, but only for searching params. It means
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# that this is the order in which Jedi searches params.
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search_param_modules = ['.']
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search_param_cache = {}
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def get_directory_modules_for_name(mods, name):
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"""
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Search a name in the directories of modules.
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"""
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def check_python_file(path):
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try:
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return cache.parser_cache[path].parser.module
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except KeyError:
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try:
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return check_fs(path)
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except IOError:
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return None
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def check_fs(path):
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with open(path) as f:
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source = modules.source_to_unicode(f.read())
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if name in source:
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return modules.Module(path, source).parser.module
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# skip non python modules
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mods = set(m for m in mods if m.path is None or m.path.endswith('.py'))
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mod_paths = set()
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for m in mods:
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mod_paths.add(m.path)
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yield m
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if settings.dynamic_params_for_other_modules:
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paths = set(settings.additional_dynamic_modules)
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for p in mod_paths:
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if p is not None:
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d = os.path.dirname(p)
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for entry in os.listdir(d):
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if entry not in mod_paths:
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if entry.endswith('.py'):
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paths.add(d + os.path.sep + entry)
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for p in sorted(paths):
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# make testing easier, sort it - same results on every interpreter
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c = check_python_file(p)
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if c is not None and c not in mods:
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yield c
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def search_param_memoize(func):
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"""
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Is only good for search params memoize, respectively the closure,
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because it just caches the input, not the func, like normal memoize does.
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"""
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def wrapper(*args, **kwargs):
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key = (args, frozenset(kwargs.items()))
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if key in search_param_cache:
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return search_param_cache[key]
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else:
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rv = func(*args, **kwargs)
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search_param_cache[key] = rv
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return rv
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return wrapper
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class ParamListener(object):
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"""
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This listener is used to get the params for a function.
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"""
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def __init__(self):
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self.param_possibilities = []
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def execute(self, params):
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self.param_possibilities.append(params)
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@memoize_default([])
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def search_params(param):
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"""
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This is a dynamic search for params. If you try to complete a type:
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>>> def func(foo):
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... foo
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>>> func(1)
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>>> func("")
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It is not known what the type is, because it cannot be guessed with
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recursive madness. Therefore one has to analyse the statements that are
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calling the function, as well as analyzing the incoming params.
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"""
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if not settings.dynamic_params:
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return []
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def get_params_for_module(module):
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"""
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Returns the values of a param, or an empty array.
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"""
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@search_param_memoize
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def get_posibilities(module, func_name):
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try:
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possible_stmts = module.used_names[func_name]
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except KeyError:
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return []
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for stmt in possible_stmts:
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if isinstance(stmt, pr.Import):
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continue
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calls = _scan_statement(stmt, func_name)
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for c in calls:
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# no execution means that params cannot be set
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call_path = list(c.generate_call_path())
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pos = c.start_pos
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scope = stmt.parent
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# this whole stuff is just to not execute certain parts
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# (speed improvement), basically we could just call
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# ``follow_call_path`` on the call_path and it would
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# also work.
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def listRightIndex(lst, value):
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return len(lst) - lst[-1::-1].index(value) - 1
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# Need to take right index, because there could be a
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# func usage before.
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i = listRightIndex(call_path, func_name)
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first, last = call_path[:i], call_path[i + 1:]
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if not last and not call_path.index(func_name) != i:
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continue
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scopes = [scope]
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if first:
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scopes = evaluate.follow_call_path(iter(first), scope, pos)
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pos = None
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for scope in scopes:
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s = evaluate.find_name(scope, func_name, position=pos,
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search_global=not first,
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resolve_decorator=False)
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c = [getattr(escope, 'base_func', None) or escope.base
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for escope in s
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if escope.isinstance(er.Function, er.Class)]
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if compare in c:
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# only if we have the correct function we execute
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# it, otherwise just ignore it.
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evaluate.follow_paths(iter(last), s, scope)
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return listener.param_possibilities
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result = []
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for params in get_posibilities(module, func_name):
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for p in params:
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if str(p) == param_name:
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result += evaluate.follow_statement(p.parent)
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return result
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func = param.get_parent_until(pr.Function)
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current_module = param.get_parent_until()
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func_name = str(func.name)
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compare = func
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if func_name == '__init__' and isinstance(func.parent, pr.Class):
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func_name = str(func.parent.name)
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compare = func.parent
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# get the param name
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if param.assignment_details:
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# first assignment details, others would be a syntax error
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commands, op = param.assignment_details[0]
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else:
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commands = param.get_commands()
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offset = 1 if commands[0] in ['*', '**'] else 0
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param_name = str(commands[offset].name)
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# add the listener
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listener = ParamListener()
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func.listeners.add(listener)
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result = []
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# This is like backtracking: Get the first possible result.
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for mod in get_directory_modules_for_name([current_module], func_name):
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result = get_params_for_module(mod)
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if result:
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break
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# cleanup: remove the listener; important: should not stick.
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func.listeners.remove(listener)
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return result
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def check_array_additions(array):
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""" Just a mapper function for the internal _check_array_additions """
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if not pr.Array.is_type(array._array, pr.Array.LIST, pr.Array.SET):
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# TODO also check for dict updates
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return []
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is_list = array._array.type == 'list'
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current_module = array._array.get_parent_until()
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res = _check_array_additions(array, current_module, is_list)
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return res
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def _scan_statement(stmt, search_name, assignment_details=False):
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""" Returns the function Call that match search_name in an Array. """
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def scan_array(arr, search_name):
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result = []
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if arr.type == pr.Array.DICT:
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for key_stmt, value_stmt in arr.items():
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result += _scan_statement(key_stmt, search_name)
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result += _scan_statement(value_stmt, search_name)
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else:
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for stmt in arr:
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result += _scan_statement(stmt, search_name)
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return result
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check = list(stmt.get_commands())
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if assignment_details:
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for commands, op in stmt.assignment_details:
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check += commands
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result = []
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for c in check:
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if isinstance(c, pr.Array):
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result += scan_array(c, search_name)
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elif isinstance(c, pr.Call):
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s_new = c
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while s_new is not None:
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n = s_new.name
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if isinstance(n, pr.Name) and search_name in n.names:
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result.append(c)
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if s_new.execution is not None:
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result += scan_array(s_new.execution, search_name)
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s_new = s_new.next
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return result
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@memoize_default([])
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def _check_array_additions(compare_array, module, is_list):
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"""
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Checks if a `pr.Array` has "add" statements:
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>>> a = [""]
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>>> a.append(1)
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"""
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if not settings.dynamic_array_additions or module.is_builtin():
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return []
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def check_calls(calls, add_name):
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"""
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Calls are processed here. The part before the call is searched and
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compared with the original Array.
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"""
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result = []
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for c in calls:
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call_path = list(c.generate_call_path())
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separate_index = call_path.index(add_name)
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if add_name == call_path[-1] or separate_index == 0:
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# this means that there is no execution -> [].append
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# or the keyword is at the start -> append()
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continue
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backtrack_path = iter(call_path[:separate_index])
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position = c.start_pos
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scope = c.get_parent_until(pr.IsScope)
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found = evaluate.follow_call_path(backtrack_path, scope, position)
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if not compare_array in found:
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continue
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params = call_path[separate_index + 1]
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if not params.values:
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continue # no params: just ignore it
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if add_name in ['append', 'add']:
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for param in params:
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result += evaluate.follow_statement(param)
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elif add_name in ['insert']:
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try:
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second_param = params[1]
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except IndexError:
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continue
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else:
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result += evaluate.follow_statement(second_param)
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elif add_name in ['extend', 'update']:
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for param in params:
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iterators = evaluate.follow_statement(param)
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result += evaluate.get_iterator_types(iterators)
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return result
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def get_execution_parent(element, *stop_classes):
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""" Used to get an Instance/Execution parent """
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if isinstance(element, er.Array):
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stmt = element._array.parent
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else:
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# is an Instance with an ArrayInstance inside
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stmt = element.var_args[0].var_args.parent
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if isinstance(stmt, er.InstanceElement):
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stop_classes = list(stop_classes) + [er.Function]
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return stmt.get_parent_until(stop_classes)
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temp_param_add = settings.dynamic_params_for_other_modules
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settings.dynamic_params_for_other_modules = False
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search_names = ['append', 'extend', 'insert'] if is_list else \
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['add', 'update']
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comp_arr_parent = get_execution_parent(compare_array, er.Execution)
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possible_stmts = []
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res = []
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for n in search_names:
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try:
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possible_stmts += module.used_names[n]
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except KeyError:
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continue
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for stmt in possible_stmts:
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# Check if the original scope is an execution. If it is, one
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# can search for the same statement, that is in the module
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# dict. Executions are somewhat special in jedi, since they
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# literally copy the contents of a function.
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if isinstance(comp_arr_parent, er.Execution):
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stmt = comp_arr_parent. \
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get_statement_for_position(stmt.start_pos)
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if stmt is None:
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continue
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# InstanceElements are special, because they don't get copied,
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# but have this wrapper around them.
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if isinstance(comp_arr_parent, er.InstanceElement):
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stmt = er.InstanceElement(comp_arr_parent.instance, stmt)
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if evaluate.follow_statement.push_stmt(stmt):
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# check recursion
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continue
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res += check_calls(_scan_statement(stmt, n), n)
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evaluate.follow_statement.pop_stmt()
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# reset settings
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settings.dynamic_params_for_other_modules = temp_param_add
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return res
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def check_array_instances(instance):
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"""Used for set() and list() instances."""
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if not settings.dynamic_arrays_instances:
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return instance.var_args
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ai = ArrayInstance(instance)
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return [ai]
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class ArrayInstance(pr.Base):
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"""
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Used for the usage of set() and list().
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This is definitely a hack, but a good one :-)
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It makes it possible to use set/list conversions.
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"""
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def __init__(self, instance):
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self.instance = instance
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self.var_args = instance.var_args
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def iter_content(self):
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"""
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The index is here just ignored, because of all the appends, etc.
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lists/sets are too complicated too handle that.
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"""
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items = []
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for stmt in self.var_args:
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for typ in evaluate.follow_statement(stmt):
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if isinstance(typ, er.Instance) and len(typ.var_args):
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array = typ.var_args[0]
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if isinstance(array, ArrayInstance):
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# prevent recursions
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# TODO compare Modules
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if self.var_args.start_pos != array.var_args.start_pos:
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items += array.iter_content()
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else:
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debug.warning(
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'ArrayInstance recursion',
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self.var_args)
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continue
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items += evaluate.get_iterator_types([typ])
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# TODO check if exclusion of tuple is a problem here.
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if isinstance(self.var_args, tuple) or self.var_args.parent is None:
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return [] # generated var_args should not be checked for arrays
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module = self.var_args.get_parent_until()
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is_list = str(self.instance.name) == 'list'
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items += _check_array_additions(self.instance, module, is_list)
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return items
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def usages(definitions, search_name, mods):
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def compare_array(definitions):
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""" `definitions` are being compared by module/start_pos, because
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sometimes the id's of the objects change (e.g. executions).
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"""
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result = []
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for d in definitions:
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module = d.get_parent_until()
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result.append((module, d.start_pos))
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return result
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def check_call(call):
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result = []
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follow = [] # There might be multiple search_name's in one call_path
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call_path = list(call.generate_call_path())
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for i, name in enumerate(call_path):
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# name is `pr.NamePart`.
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if name == search_name:
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follow.append(call_path[:i + 1])
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for f in follow:
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follow_res, search = evaluate.goto(call.parent, f)
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follow_res = usages_add_import_modules(follow_res, search)
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compare_follow_res = compare_array(follow_res)
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# compare to see if they match
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if any(r in compare_definitions for r in compare_follow_res):
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scope = call.parent
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result.append(api_classes.Usage(search, scope))
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return result
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if not definitions:
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return set()
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compare_definitions = compare_array(definitions)
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mods |= set([d.get_parent_until() for d in definitions])
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names = []
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for m in get_directory_modules_for_name(mods, search_name):
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try:
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stmts = m.used_names[search_name]
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except KeyError:
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continue
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for stmt in stmts:
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if isinstance(stmt, pr.Import):
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count = 0
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imps = []
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for i in stmt.get_all_import_names():
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for name_part in i.names:
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count += 1
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if name_part == search_name:
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imps.append((count, name_part))
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for used_count, name_part in imps:
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i = imports.ImportPath(_evaluator, stmt, kill_count=count - used_count,
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direct_resolve=True)
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f = i.follow(is_goto=True)
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if set(f) & set(definitions):
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names.append(api_classes.Usage(name_part, stmt))
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else:
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for call in _scan_statement(stmt, search_name,
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assignment_details=True):
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names += check_call(call)
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return names
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def usages_add_import_modules(definitions, search_name):
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""" Adds the modules of the imports """
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new = set()
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for d in definitions:
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if isinstance(d.parent, pr.Import):
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s = imports.ImportPath(_evaluator, d.parent, direct_resolve=True)
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with common.ignored(IndexError):
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new.add(s.follow(is_goto=True)[0])
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return set(definitions) | new
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|
def check_flow_information(flow, search_name, pos):
|
|
""" Try to find out the type of a variable just with the information that
|
|
is given by the flows: e.g. It is also responsible for assert checks.::
|
|
|
|
if isinstance(k, str):
|
|
k. # <- completion here
|
|
|
|
ensures that `k` is a string.
|
|
"""
|
|
if not settings.dynamic_flow_information:
|
|
return None
|
|
result = []
|
|
if isinstance(flow, (pr.Scope, fast_parser.Module)) and not result:
|
|
for ass in reversed(flow.asserts):
|
|
if pos is None or ass.start_pos > pos:
|
|
continue
|
|
result = _check_isinstance_type(ass, search_name)
|
|
if result:
|
|
break
|
|
|
|
if isinstance(flow, pr.Flow) and not result:
|
|
if flow.command in ['if', 'while'] and len(flow.inputs) == 1:
|
|
result = _check_isinstance_type(flow.inputs[0], search_name)
|
|
return result
|
|
|
|
|
|
def _check_isinstance_type(stmt, search_name):
|
|
try:
|
|
commands = stmt.get_commands()
|
|
# this might be removed if we analyze and, etc
|
|
assert len(commands) == 1
|
|
call = commands[0]
|
|
assert isinstance(call, pr.Call) and str(call.name) == 'isinstance'
|
|
assert bool(call.execution)
|
|
|
|
# isinstance check
|
|
isinst = call.execution.values
|
|
assert len(isinst) == 2 # has two params
|
|
obj, classes = [statement.get_commands() for statement in isinst]
|
|
assert len(obj) == 1
|
|
assert len(classes) == 1
|
|
assert isinstance(obj[0], pr.Call)
|
|
# names fit?
|
|
assert str(obj[0].name) == search_name
|
|
assert isinstance(classes[0], pr.StatementElement) # can be type or tuple
|
|
except AssertionError:
|
|
return []
|
|
|
|
result = []
|
|
for c in evaluate.follow_call(classes[0]):
|
|
if isinstance(c, er.Array):
|
|
result += c.get_index_types()
|
|
else:
|
|
result.append(c)
|
|
for i, c in enumerate(result):
|
|
result[i] = er.Instance(c)
|
|
return result
|