Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/astroid/manager.py: 31%
229 statements
« prev ^ index » next coverage.py v7.2.7, created at 2023-06-07 06:53 +0000
1# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
2# For details: https://github.com/pylint-dev/astroid/blob/main/LICENSE
3# Copyright (c) https://github.com/pylint-dev/astroid/blob/main/CONTRIBUTORS.txt
5"""astroid manager: avoid multiple astroid build of a same module when
6possible by providing a class responsible to get astroid representation
7from various source and using a cache of built modules)
8"""
10from __future__ import annotations
12import collections
13import os
14import types
15import zipimport
16from collections.abc import Callable, Iterator, Sequence
17from importlib.util import find_spec, module_from_spec
18from typing import Any, ClassVar
20from astroid import nodes
21from astroid.const import BRAIN_MODULES_DIRECTORY
22from astroid.context import InferenceContext, _invalidate_cache
23from astroid.exceptions import AstroidBuildingError, AstroidImportError
24from astroid.interpreter._import import spec, util
25from astroid.modutils import (
26 NoSourceFile,
27 _cache_normalize_path_,
28 file_info_from_modpath,
29 get_source_file,
30 is_module_name_part_of_extension_package_whitelist,
31 is_python_source,
32 is_stdlib_module,
33 load_module_from_name,
34 modpath_from_file,
35)
36from astroid.transforms import TransformVisitor
37from astroid.typing import AstroidManagerBrain, InferenceResult
39ZIP_IMPORT_EXTS = (".zip", ".egg", ".whl", ".pyz", ".pyzw")
42def safe_repr(obj: Any) -> str:
43 try:
44 return repr(obj)
45 except Exception: # pylint: disable=broad-except
46 return "???"
49class AstroidManager:
50 """Responsible to build astroid from files or modules.
52 Use the Borg (singleton) pattern.
53 """
55 name = "astroid loader"
56 brain: AstroidManagerBrain = {
57 "astroid_cache": {},
58 "_mod_file_cache": {},
59 "_failed_import_hooks": [],
60 "always_load_extensions": False,
61 "optimize_ast": False,
62 "extension_package_whitelist": set(),
63 "_transform": TransformVisitor(),
64 }
65 max_inferable_values: ClassVar[int] = 100
67 def __init__(self) -> None:
68 # NOTE: cache entries are added by the [re]builder
69 self.astroid_cache = AstroidManager.brain["astroid_cache"]
70 self._mod_file_cache = AstroidManager.brain["_mod_file_cache"]
71 self._failed_import_hooks = AstroidManager.brain["_failed_import_hooks"]
72 self.always_load_extensions = AstroidManager.brain["always_load_extensions"]
73 self.optimize_ast = AstroidManager.brain["optimize_ast"]
74 self.extension_package_whitelist = AstroidManager.brain[
75 "extension_package_whitelist"
76 ]
77 self._transform = AstroidManager.brain["_transform"]
79 @property
80 def register_transform(self):
81 # This and unregister_transform below are exported for convenience
82 return self._transform.register_transform
84 @property
85 def unregister_transform(self):
86 return self._transform.unregister_transform
88 @property
89 def builtins_module(self) -> nodes.Module:
90 return self.astroid_cache["builtins"]
92 def visit_transforms(self, node: nodes.NodeNG) -> InferenceResult:
93 """Visit the transforms and apply them to the given *node*."""
94 return self._transform.visit(node)
96 def ast_from_file(
97 self,
98 filepath: str,
99 modname: str | None = None,
100 fallback: bool = True,
101 source: bool = False,
102 ) -> nodes.Module:
103 """Given a module name, return the astroid object."""
104 if modname is None:
105 try:
106 modname = ".".join(modpath_from_file(filepath))
107 except ImportError:
108 modname = filepath
109 if (
110 modname in self.astroid_cache
111 and self.astroid_cache[modname].file == filepath
112 ):
113 return self.astroid_cache[modname]
114 # Call get_source_file() only after a cache miss,
115 # since it calls os.path.exists().
116 try:
117 filepath = get_source_file(filepath, include_no_ext=True)
118 source = True
119 except NoSourceFile:
120 pass
121 # Second attempt on the cache after get_source_file().
122 if (
123 modname in self.astroid_cache
124 and self.astroid_cache[modname].file == filepath
125 ):
126 return self.astroid_cache[modname]
127 if source:
128 # pylint: disable=import-outside-toplevel; circular import
129 from astroid.builder import AstroidBuilder
131 return AstroidBuilder(self).file_build(filepath, modname)
132 if fallback and modname:
133 return self.ast_from_module_name(modname)
134 raise AstroidBuildingError("Unable to build an AST for {path}.", path=filepath)
136 def ast_from_string(
137 self, data: str, modname: str = "", filepath: str | None = None
138 ) -> nodes.Module:
139 """Given some source code as a string, return its corresponding astroid
140 object.
141 """
142 # pylint: disable=import-outside-toplevel; circular import
143 from astroid.builder import AstroidBuilder
145 return AstroidBuilder(self).string_build(data, modname, filepath)
147 def _build_stub_module(self, modname: str) -> nodes.Module:
148 # pylint: disable=import-outside-toplevel; circular import
149 from astroid.builder import AstroidBuilder
151 return AstroidBuilder(self).string_build("", modname)
153 def _build_namespace_module(
154 self, modname: str, path: Sequence[str]
155 ) -> nodes.Module:
156 # pylint: disable=import-outside-toplevel; circular import
157 from astroid.builder import build_namespace_package_module
159 return build_namespace_package_module(modname, path)
161 def _can_load_extension(self, modname: str) -> bool:
162 if self.always_load_extensions:
163 return True
164 if is_stdlib_module(modname):
165 return True
166 return is_module_name_part_of_extension_package_whitelist(
167 modname, self.extension_package_whitelist
168 )
170 def ast_from_module_name( # noqa: C901
171 self,
172 modname: str | None,
173 context_file: str | None = None,
174 use_cache: bool = True,
175 ) -> nodes.Module:
176 """Given a module name, return the astroid object."""
177 if modname is None:
178 raise AstroidBuildingError("No module name given.")
179 # Sometimes we don't want to use the cache. For example, when we're
180 # importing a module with the same name as the file that is importing
181 # we want to fallback on the import system to make sure we get the correct
182 # module.
183 if modname in self.astroid_cache and use_cache:
184 return self.astroid_cache[modname]
185 if modname == "__main__":
186 return self._build_stub_module(modname)
187 if context_file:
188 old_cwd = os.getcwd()
189 os.chdir(os.path.dirname(context_file))
190 try:
191 found_spec = self.file_from_module_name(modname, context_file)
192 if found_spec.type == spec.ModuleType.PY_ZIPMODULE:
193 module = self.zip_import_data(found_spec.location)
194 if module is not None:
195 return module
197 elif found_spec.type in (
198 spec.ModuleType.C_BUILTIN,
199 spec.ModuleType.C_EXTENSION,
200 ):
201 if (
202 found_spec.type == spec.ModuleType.C_EXTENSION
203 and not self._can_load_extension(modname)
204 ):
205 return self._build_stub_module(modname)
206 try:
207 named_module = load_module_from_name(modname)
208 except Exception as e:
209 raise AstroidImportError(
210 "Loading {modname} failed with:\n{error}",
211 modname=modname,
212 path=found_spec.location,
213 ) from e
214 return self.ast_from_module(named_module, modname)
216 elif found_spec.type == spec.ModuleType.PY_COMPILED:
217 raise AstroidImportError(
218 "Unable to load compiled module {modname}.",
219 modname=modname,
220 path=found_spec.location,
221 )
223 elif found_spec.type == spec.ModuleType.PY_NAMESPACE:
224 return self._build_namespace_module(
225 modname, found_spec.submodule_search_locations or []
226 )
227 elif found_spec.type == spec.ModuleType.PY_FROZEN:
228 if found_spec.location is None:
229 return self._build_stub_module(modname)
230 # For stdlib frozen modules we can determine the location and
231 # can therefore create a module from the source file
232 return self.ast_from_file(found_spec.location, modname, fallback=False)
234 if found_spec.location is None:
235 raise AstroidImportError(
236 "Can't find a file for module {modname}.", modname=modname
237 )
239 return self.ast_from_file(found_spec.location, modname, fallback=False)
240 except AstroidBuildingError as e:
241 for hook in self._failed_import_hooks:
242 try:
243 return hook(modname)
244 except AstroidBuildingError:
245 pass
246 raise e
247 finally:
248 if context_file:
249 os.chdir(old_cwd)
251 def zip_import_data(self, filepath: str) -> nodes.Module | None:
252 if zipimport is None:
253 return None
255 # pylint: disable=import-outside-toplevel; circular import
256 from astroid.builder import AstroidBuilder
258 builder = AstroidBuilder(self)
259 for ext in ZIP_IMPORT_EXTS:
260 try:
261 eggpath, resource = filepath.rsplit(ext + os.path.sep, 1)
262 except ValueError:
263 continue
264 try:
265 importer = zipimport.zipimporter(eggpath + ext)
266 zmodname = resource.replace(os.path.sep, ".")
267 if importer.is_package(resource):
268 zmodname = zmodname + ".__init__"
269 module = builder.string_build(
270 importer.get_source(resource), zmodname, filepath
271 )
272 return module
273 except Exception: # pylint: disable=broad-except
274 continue
275 return None
277 def file_from_module_name(
278 self, modname: str, contextfile: str | None
279 ) -> spec.ModuleSpec:
280 try:
281 value = self._mod_file_cache[(modname, contextfile)]
282 except KeyError:
283 try:
284 value = file_info_from_modpath(
285 modname.split("."), context_file=contextfile
286 )
287 except ImportError as e:
288 # pylint: disable-next=redefined-variable-type
289 value = AstroidImportError(
290 "Failed to import module {modname} with error:\n{error}.",
291 modname=modname,
292 # we remove the traceback here to save on memory usage (since these exceptions are cached)
293 error=e.with_traceback(None),
294 )
295 self._mod_file_cache[(modname, contextfile)] = value
296 if isinstance(value, AstroidBuildingError):
297 # we remove the traceback here to save on memory usage (since these exceptions are cached)
298 raise value.with_traceback(None) # pylint: disable=no-member
299 return value
301 def ast_from_module(
302 self, module: types.ModuleType, modname: str | None = None
303 ) -> nodes.Module:
304 """Given an imported module, return the astroid object."""
305 modname = modname or module.__name__
306 if modname in self.astroid_cache:
307 return self.astroid_cache[modname]
308 try:
309 # some builtin modules don't have __file__ attribute
310 filepath = module.__file__
311 if is_python_source(filepath):
312 # Type is checked in is_python_source
313 return self.ast_from_file(filepath, modname) # type: ignore[arg-type]
314 except AttributeError:
315 pass
317 # pylint: disable=import-outside-toplevel; circular import
318 from astroid.builder import AstroidBuilder
320 return AstroidBuilder(self).module_build(module, modname)
322 def ast_from_class(self, klass: type, modname: str | None = None) -> nodes.ClassDef:
323 """Get astroid for the given class."""
324 if modname is None:
325 try:
326 modname = klass.__module__
327 except AttributeError as exc:
328 raise AstroidBuildingError(
329 "Unable to get module for class {class_name}.",
330 cls=klass,
331 class_repr=safe_repr(klass),
332 modname=modname,
333 ) from exc
334 modastroid = self.ast_from_module_name(modname)
335 ret = modastroid.getattr(klass.__name__)[0]
336 assert isinstance(ret, nodes.ClassDef)
337 return ret
339 def infer_ast_from_something(
340 self, obj: object, context: InferenceContext | None = None
341 ) -> Iterator[InferenceResult]:
342 """Infer astroid for the given class."""
343 if hasattr(obj, "__class__") and not isinstance(obj, type):
344 klass = obj.__class__
345 elif isinstance(obj, type):
346 klass = obj
347 else:
348 raise AstroidBuildingError( # pragma: no cover
349 "Unable to get type for {class_repr}.",
350 cls=None,
351 class_repr=safe_repr(obj),
352 )
353 try:
354 modname = klass.__module__
355 except AttributeError as exc:
356 raise AstroidBuildingError(
357 "Unable to get module for {class_repr}.",
358 cls=klass,
359 class_repr=safe_repr(klass),
360 ) from exc
361 except Exception as exc:
362 raise AstroidImportError(
363 "Unexpected error while retrieving module for {class_repr}:\n"
364 "{error}",
365 cls=klass,
366 class_repr=safe_repr(klass),
367 ) from exc
368 try:
369 name = klass.__name__
370 except AttributeError as exc:
371 raise AstroidBuildingError(
372 "Unable to get name for {class_repr}:\n",
373 cls=klass,
374 class_repr=safe_repr(klass),
375 ) from exc
376 except Exception as exc:
377 raise AstroidImportError(
378 "Unexpected error while retrieving name for {class_repr}:\n{error}",
379 cls=klass,
380 class_repr=safe_repr(klass),
381 ) from exc
382 # take care, on living object __module__ is regularly wrong :(
383 modastroid = self.ast_from_module_name(modname)
384 if klass is obj:
385 for inferred in modastroid.igetattr(name, context):
386 yield inferred
387 else:
388 for inferred in modastroid.igetattr(name, context):
389 yield inferred.instantiate_class()
391 def register_failed_import_hook(self, hook: Callable[[str], nodes.Module]) -> None:
392 """Registers a hook to resolve imports that cannot be found otherwise.
394 `hook` must be a function that accepts a single argument `modname` which
395 contains the name of the module or package that could not be imported.
396 If `hook` can resolve the import, must return a node of type `astroid.Module`,
397 otherwise, it must raise `AstroidBuildingError`.
398 """
399 self._failed_import_hooks.append(hook)
401 def cache_module(self, module: nodes.Module) -> None:
402 """Cache a module if no module with the same name is known yet."""
403 self.astroid_cache.setdefault(module.name, module)
405 def bootstrap(self) -> None:
406 """Bootstrap the required AST modules needed for the manager to work.
408 The bootstrap usually involves building the AST for the builtins
409 module, which is required by the rest of astroid to work correctly.
410 """
411 from astroid import raw_building # pylint: disable=import-outside-toplevel
413 raw_building._astroid_bootstrapping()
415 def clear_cache(self) -> None:
416 """Clear the underlying caches, bootstrap the builtins module and
417 re-register transforms.
418 """
419 # import here because of cyclic imports
420 # pylint: disable=import-outside-toplevel
421 from astroid.inference_tip import clear_inference_tip_cache
422 from astroid.interpreter.objectmodel import ObjectModel
423 from astroid.nodes.node_classes import LookupMixIn
424 from astroid.nodes.scoped_nodes import ClassDef
426 clear_inference_tip_cache()
427 _invalidate_cache() # inference context cache
429 self.astroid_cache.clear()
430 # NB: not a new TransformVisitor()
431 AstroidManager.brain["_transform"].transforms = collections.defaultdict(list)
433 for lru_cache in (
434 LookupMixIn.lookup,
435 _cache_normalize_path_,
436 util.is_namespace,
437 ObjectModel.attributes,
438 ClassDef._metaclass_lookup_attribute,
439 ):
440 lru_cache.cache_clear() # type: ignore[attr-defined]
442 self.bootstrap()
444 # Reload brain plugins. During initialisation this is done in astroid.__init__.py
445 for module in BRAIN_MODULES_DIRECTORY.iterdir():
446 if module.suffix == ".py":
447 module_spec = find_spec(f"astroid.brain.{module.stem}")
448 assert module_spec
449 module_object = module_from_spec(module_spec)
450 assert module_spec.loader
451 module_spec.loader.exec_module(module_object)