bpo-35936: Updates to modulefinder (GH-11787)

* Properly handle SyntaxErrors in Python source files.

SyntaxErrors in the target module will rise normally, while SyntaxErrors in dependencies will be added to badmodules. This includes a new regression test.

* Fix name collision bug.

This fixes an issue where a "fromlist" import with the same name as a previously failed import would be incorrectly added to badmodules. This includes a new regression test.

* Replace mutable default values.

Bound empty lists have been replaced with the "if param is None" idiom.

* Replace deprecated imp usage.

Constants imported from imp have been moved to private module-level constants, and ModuleFinder.find_module has been refactored to use importlib. Other than an improvement on how frozen builtin imports are reported (as the frozen imports they are, rather than the stdlib modules they *may* have originated from), these changes maintain complete compatibility with past versions... including odd behavior for returning relative (below current directory, but not a C extension) vs. absolute (above current directory, or a C extension) paths.

Patch by Brandt Bucher.
This commit is contained in:
Brandt Bucher 2019-04-07 01:00:41 -07:00 committed by Nick Coghlan
parent 2dad96013c
commit 9d7b2c0909
6 changed files with 116 additions and 16 deletions

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@ -8,9 +8,7 @@ import os
import sys
import types
import warnings
with warnings.catch_warnings():
warnings.simplefilter('ignore', DeprecationWarning)
import imp
LOAD_CONST = dis.opmap['LOAD_CONST']
IMPORT_NAME = dis.opmap['IMPORT_NAME']
@ -19,6 +17,16 @@ STORE_GLOBAL = dis.opmap['STORE_GLOBAL']
STORE_OPS = STORE_NAME, STORE_GLOBAL
EXTENDED_ARG = dis.EXTENDED_ARG
# Old imp constants:
_SEARCH_ERROR = 0
_PY_SOURCE = 1
_PY_COMPILED = 2
_C_EXTENSION = 3
_PKG_DIRECTORY = 5
_C_BUILTIN = 6
_PY_FROZEN = 7
# Modulefinder does a good job at simulating Python's, but it can not
# handle __path__ modifications packages make at runtime. Therefore there
# is a mechanism whereby you can register extra paths in this map for a
@ -43,6 +51,54 @@ def ReplacePackage(oldname, newname):
replacePackageMap[oldname] = newname
def _find_module(name, path=None):
"""An importlib reimplementation of imp.find_module (for our purposes)."""
# It's necessary to clear the caches for our Finder first, in case any
# modules are being added/deleted/modified at runtime. In particular,
# test_modulefinder.py changes file tree contents in a cache-breaking way:
importlib.machinery.PathFinder.invalidate_caches()
spec = importlib.machinery.PathFinder.find_spec(name, path)
if spec is None:
raise ImportError("No module named {name!r}".format(name=name), name=name)
# Some special cases:
if spec.loader is importlib.machinery.BuiltinImporter:
return None, None, ("", "", _C_BUILTIN)
if spec.loader is importlib.machinery.FrozenImporter:
return None, None, ("", "", _PY_FROZEN)
file_path = spec.origin
if spec.loader.is_package(name):
return None, os.path.dirname(file_path), ("", "", _PKG_DIRECTORY)
if isinstance(spec.loader, importlib.machinery.SourceFileLoader):
kind = _PY_SOURCE
mode = "r"
elif isinstance(spec.loader, importlib.machinery.ExtensionFileLoader):
kind = _C_EXTENSION
mode = "rb"
elif isinstance(spec.loader, importlib.machinery.SourcelessFileLoader):
kind = _PY_COMPILED
mode = "rb"
else: # Should never happen.
return None, None, ("", "", _SEARCH_ERROR)
file = open(file_path, mode)
suffix = os.path.splitext(file_path)[-1]
return file, file_path, (suffix, mode, kind)
class Module:
def __init__(self, name, file=None, path=None):
@ -69,7 +125,7 @@ class Module:
class ModuleFinder:
def __init__(self, path=None, debug=0, excludes=[], replace_paths=[]):
def __init__(self, path=None, debug=0, excludes=None, replace_paths=None):
if path is None:
path = sys.path
self.path = path
@ -77,8 +133,8 @@ class ModuleFinder:
self.badmodules = {}
self.debug = debug
self.indent = 0
self.excludes = excludes
self.replace_paths = replace_paths
self.excludes = excludes if excludes is not None else []
self.replace_paths = replace_paths if replace_paths is not None else []
self.processed_paths = [] # Used in debugging only
def msg(self, level, str, *args):
@ -105,14 +161,14 @@ class ModuleFinder:
def run_script(self, pathname):
self.msg(2, "run_script", pathname)
with open(pathname) as fp:
stuff = ("", "r", imp.PY_SOURCE)
stuff = ("", "r", _PY_SOURCE)
self.load_module('__main__', fp, pathname, stuff)
def load_file(self, pathname):
dir, name = os.path.split(pathname)
name, ext = os.path.splitext(name)
with open(pathname) as fp:
stuff = (ext, "r", imp.PY_SOURCE)
stuff = (ext, "r", _PY_SOURCE)
self.load_module(name, fp, pathname, stuff)
def import_hook(self, name, caller=None, fromlist=None, level=-1):
@ -279,13 +335,13 @@ class ModuleFinder:
def load_module(self, fqname, fp, pathname, file_info):
suffix, mode, type = file_info
self.msgin(2, "load_module", fqname, fp and "fp", pathname)
if type == imp.PKG_DIRECTORY:
if type == _PKG_DIRECTORY:
m = self.load_package(fqname, pathname)
self.msgout(2, "load_module ->", m)
return m
if type == imp.PY_SOURCE:
if type == _PY_SOURCE:
co = compile(fp.read()+'\n', pathname, 'exec')
elif type == imp.PY_COMPILED:
elif type == _PY_COMPILED:
try:
data = fp.read()
importlib._bootstrap_external._classify_pyc(data, fqname, {})
@ -323,17 +379,20 @@ class ModuleFinder:
except ImportError as msg:
self.msg(2, "ImportError:", str(msg))
self._add_badmodule(name, caller)
except SyntaxError as msg:
self.msg(2, "SyntaxError:", str(msg))
self._add_badmodule(name, caller)
else:
if fromlist:
for sub in fromlist:
if sub in self.badmodules:
self._add_badmodule(sub, caller)
fullname = name + "." + sub
if fullname in self.badmodules:
self._add_badmodule(fullname, caller)
continue
try:
self.import_hook(name, caller, [sub], level=level)
except ImportError as msg:
self.msg(2, "ImportError:", str(msg))
fullname = name + "." + sub
self._add_badmodule(fullname, caller)
def scan_opcodes(self, co):
@ -445,10 +504,11 @@ class ModuleFinder:
if path is None:
if name in sys.builtin_module_names:
return (None, None, ("", "", imp.C_BUILTIN))
return (None, None, ("", "", _C_BUILTIN))
path = self.path
return imp.find_module(name, path)
return _find_module(name, path)
def report(self):
"""Print a report to stdout, listing the found modules with their

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@ -218,6 +218,33 @@ bytecode_test = [
""
]
syntax_error_test = [
"a.module",
["a", "a.module", "b"],
["b.module"], [],
"""\
a/__init__.py
a/module.py
import b.module
b/__init__.py
b/module.py
? # SyntaxError: invalid syntax
"""]
same_name_as_bad_test = [
"a.module",
["a", "a.module", "b", "b.c"],
["c"], [],
"""\
a/__init__.py
a/module.py
import c
from b import c
b/__init__.py
b/c.py
"""]
def open_file(path):
dirname = os.path.dirname(path)
@ -299,6 +326,12 @@ class ModuleFinderTest(unittest.TestCase):
def test_relative_imports_4(self):
self._do_test(relative_import_test_4)
def test_syntax_error(self):
self._do_test(syntax_error_test)
def test_same_name_as_bad(self):
self._do_test(same_name_as_bad_test)
def test_bytecode(self):
base_path = os.path.join(TEST_DIR, 'a')
source_path = base_path + importlib.machinery.SOURCE_SUFFIXES[0]

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@ -222,6 +222,7 @@ Ian Bruntlett
Floris Bruynooghe
Matt Bryant
Stan Bubrouski
Brandt Bucher
Colm Buckley
Erik de Bueger
Jan-Hein Bührman

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@ -0,0 +1,2 @@
:mod:`modulefinder` no longer crashes when encountering syntax errors in followed imports.
Patch by Brandt Bucher.

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@ -0,0 +1,2 @@
:mod:`modulefinder` correctly handles modules that have the same name as a bad package.
Patch by Brandt Bucher.

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@ -0,0 +1,2 @@
:mod:`modulefinder` no longer depends on the deprecated :mod:`imp` module, and the initializer for :class:`modulefinder.ModuleFinder` now has immutable default arguments.
Patch by Brandt Bucher.