cpython/Tools/c-analyzer/c_common/fsutil.py

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import fnmatch
import glob
import os
import os.path
import shutil
import stat
from .iterutil import iter_many
USE_CWD = object()
C_SOURCE_SUFFIXES = ('.c', '.h')
def create_backup(old, backup=None):
if isinstance(old, str):
filename = old
else:
filename = getattr(old, 'name', None)
if not filename:
return None
if not backup or backup is True:
backup = f'{filename}.bak'
try:
shutil.copyfile(filename, backup)
except FileNotFoundError as exc:
if exc.filename != filename:
raise # re-raise
backup = None
return backup
##################################
# filenames
def fix_filename(filename, relroot=USE_CWD, *,
fixroot=True,
_badprefix=f'..{os.path.sep}',
):
"""Return a normalized, absolute-path copy of the given filename."""
if not relroot or relroot is USE_CWD:
return os.path.abspath(filename)
if fixroot:
relroot = os.path.abspath(relroot)
return _fix_filename(filename, relroot)
def _fix_filename(filename, relroot, *,
_badprefix=f'..{os.path.sep}',
):
orig = filename
# First we normalize.
filename = os.path.normpath(filename)
if filename.startswith(_badprefix):
raise ValueError(f'bad filename {orig!r} (resolves beyond relative root')
# Now make sure it is absolute (relative to relroot).
if not os.path.isabs(filename):
filename = os.path.join(relroot, filename)
else:
relpath = os.path.relpath(filename, relroot)
if os.path.join(relroot, relpath) != filename:
raise ValueError(f'expected {relroot!r} as lroot, got {orig!r}')
return filename
def fix_filenames(filenames, relroot=USE_CWD):
if not relroot or relroot is USE_CWD:
filenames = (os.path.abspath(v) for v in filenames)
else:
relroot = os.path.abspath(relroot)
filenames = (_fix_filename(v, relroot) for v in filenames)
return filenames, relroot
def format_filename(filename, relroot=USE_CWD, *,
fixroot=True,
normalize=True,
_badprefix=f'..{os.path.sep}',
):
"""Return a consistent relative-path representation of the filename."""
orig = filename
if normalize:
filename = os.path.normpath(filename)
if relroot is None:
# Otherwise leave it as-is.
return filename
elif relroot is USE_CWD:
# Make it relative to CWD.
filename = os.path.relpath(filename)
else:
# Make it relative to "relroot".
if fixroot:
relroot = os.path.abspath(relroot)
elif not relroot:
raise ValueError('missing relroot')
filename = os.path.relpath(filename, relroot)
if filename.startswith(_badprefix):
raise ValueError(f'bad filename {orig!r} (resolves beyond relative root')
return filename
##################################
# find files
def match_glob(filename, pattern):
if fnmatch.fnmatch(filename, pattern):
return True
# fnmatch doesn't handle ** quite right. It will not match the
# following:
#
# ('x/spam.py', 'x/**/*.py')
# ('spam.py', '**/*.py')
#
# though it *will* match the following:
#
# ('x/y/spam.py', 'x/**/*.py')
# ('x/spam.py', '**/*.py')
if '**/' not in pattern:
return False
# We only accommodate the single-"**" case.
return fnmatch.fnmatch(filename, pattern.replace('**/', '', 1))
def process_filenames(filenames, *,
start=None,
include=None,
exclude=None,
relroot=USE_CWD,
):
if relroot and relroot is not USE_CWD:
relroot = os.path.abspath(relroot)
if start:
start = fix_filename(start, relroot, fixroot=False)
if include:
include = set(fix_filename(v, relroot, fixroot=False)
for v in include)
if exclude:
exclude = set(fix_filename(v, relroot, fixroot=False)
for v in exclude)
onempty = Exception('no filenames provided')
for filename, solo in iter_many(filenames, onempty):
filename = fix_filename(filename, relroot, fixroot=False)
relfile = format_filename(filename, relroot, fixroot=False, normalize=False)
check, start = _get_check(filename, start, include, exclude)
yield filename, relfile, check, solo
def expand_filenames(filenames):
for filename in filenames:
# XXX Do we need to use glob.escape (a la commit 9355868458, GH-20994)?
if '**/' in filename:
yield from glob.glob(filename.replace('**/', ''))
yield from glob.glob(filename)
def _get_check(filename, start, include, exclude):
if start and filename != start:
return (lambda: '<skipped>'), start
else:
def check():
if _is_excluded(filename, exclude, include):
return '<excluded>'
return None
return check, None
def _is_excluded(filename, exclude, include):
if include:
for included in include:
if match_glob(filename, included):
return False
return True
elif exclude:
for excluded in exclude:
if match_glob(filename, excluded):
return True
return False
else:
return False
def _walk_tree(root, *,
_walk=os.walk,
):
# A wrapper around os.walk that resolves the filenames.
for parent, _, names in _walk(root):
for name in names:
yield os.path.join(parent, name)
def walk_tree(root, *,
suffix=None,
walk=_walk_tree,
):
"""Yield each file in the tree under the given directory name.
If "suffix" is provided then only files with that suffix will
be included.
"""
if suffix and not isinstance(suffix, str):
raise ValueError('suffix must be a string')
for filename in walk(root):
if suffix and not filename.endswith(suffix):
continue
yield filename
def glob_tree(root, *,
suffix=None,
_glob=glob.iglob,
):
"""Yield each file in the tree under the given directory name.
If "suffix" is provided then only files with that suffix will
be included.
"""
suffix = suffix or ''
if not isinstance(suffix, str):
raise ValueError('suffix must be a string')
for filename in _glob(f'{root}/*{suffix}'):
yield filename
for filename in _glob(f'{root}/**/*{suffix}'):
yield filename
def iter_files(root, suffix=None, relparent=None, *,
get_files=os.walk,
_glob=glob_tree,
_walk=walk_tree,
):
"""Yield each file in the tree under the given directory name.
If "root" is a non-string iterable then do the same for each of
those trees.
If "suffix" is provided then only files with that suffix will
be included.
if "relparent" is provided then it is used to resolve each
filename as a relative path.
"""
if not isinstance(root, str):
roots = root
for root in roots:
yield from iter_files(root, suffix, relparent,
get_files=get_files,
_glob=_glob, _walk=_walk)
return
# Use the right "walk" function.
if get_files in (glob.glob, glob.iglob, glob_tree):
get_files = _glob
else:
_files = _walk_tree if get_files in (os.walk, walk_tree) else get_files
get_files = (lambda *a, **k: _walk(*a, walk=_files, **k))
# Handle a single suffix.
if suffix and not isinstance(suffix, str):
filenames = get_files(root)
suffix = tuple(suffix)
else:
filenames = get_files(root, suffix=suffix)
suffix = None
for filename in filenames:
if suffix and not isinstance(suffix, str): # multiple suffixes
if not filename.endswith(suffix):
continue
if relparent:
filename = os.path.relpath(filename, relparent)
yield filename
def iter_files_by_suffix(root, suffixes, relparent=None, *,
walk=walk_tree,
_iter_files=iter_files,
):
"""Yield each file in the tree that has the given suffixes.
Unlike iter_files(), the results are in the original suffix order.
"""
if isinstance(suffixes, str):
suffixes = [suffixes]
# XXX Ignore repeated suffixes?
for suffix in suffixes:
yield from _iter_files(root, suffix, relparent)
##################################
# file info
# XXX posix-only?
S_IRANY = stat.S_IRUSR | stat.S_IRGRP | stat.S_IROTH
S_IWANY = stat.S_IWUSR | stat.S_IWGRP | stat.S_IWOTH
S_IXANY = stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH
def is_readable(file, *, user=None, check=False):
filename, st, mode = _get_file_info(file)
if check:
try:
okay = _check_file(filename, S_IRANY)
except NotImplementedError:
okay = NotImplemented
if okay is not NotImplemented:
return okay
# Fall back to checking the mode.
return _check_mode(st, mode, S_IRANY, user)
def is_writable(file, *, user=None, check=False):
filename, st, mode = _get_file_info(file)
if check:
try:
okay = _check_file(filename, S_IWANY)
except NotImplementedError:
okay = NotImplemented
if okay is not NotImplemented:
return okay
# Fall back to checking the mode.
return _check_mode(st, mode, S_IWANY, user)
def is_executable(file, *, user=None, check=False):
filename, st, mode = _get_file_info(file)
if check:
try:
okay = _check_file(filename, S_IXANY)
except NotImplementedError:
okay = NotImplemented
if okay is not NotImplemented:
return okay
# Fall back to checking the mode.
return _check_mode(st, mode, S_IXANY, user)
def _get_file_info(file):
filename = st = mode = None
if isinstance(file, int):
mode = file
elif isinstance(file, os.stat_result):
st = file
else:
if isinstance(file, str):
filename = file
elif hasattr(file, 'name') and os.path.exists(file.name):
filename = file.name
else:
raise NotImplementedError(file)
st = os.stat(filename)
return filename, st, mode or st.st_mode
def _check_file(filename, check):
if not isinstance(filename, str):
raise Exception(f'filename required to check file, got {filename}')
if check & S_IRANY:
flags = os.O_RDONLY
elif check & S_IWANY:
flags = os.O_WRONLY
elif check & S_IXANY:
# We can worry about S_IXANY later
return NotImplemented
else:
raise NotImplementedError(check)
try:
fd = os.open(filename, flags)
except PermissionError:
return False
# We do not ignore other exceptions.
else:
os.close(fd)
return True
def _get_user_info(user):
import pwd
username = uid = gid = groups = None
if user is None:
uid = os.geteuid()
#username = os.getlogin()
username = pwd.getpwuid(uid)[0]
gid = os.getgid()
groups = os.getgroups()
else:
if isinstance(user, int):
uid = user
entry = pwd.getpwuid(uid)
username = entry.pw_name
elif isinstance(user, str):
username = user
entry = pwd.getpwnam(username)
uid = entry.pw_uid
else:
raise NotImplementedError(user)
gid = entry.pw_gid
os.getgrouplist(username, gid)
return username, uid, gid, groups
def _check_mode(st, mode, check, user):
orig = check
_, uid, gid, groups = _get_user_info(user)
if check & S_IRANY:
check -= S_IRANY
matched = False
if mode & stat.S_IRUSR:
if st.st_uid == uid:
matched = True
if mode & stat.S_IRGRP:
if st.st_uid == gid or st.st_uid in groups:
matched = True
if mode & stat.S_IROTH:
matched = True
if not matched:
return False
if check & S_IWANY:
check -= S_IWANY
matched = False
if mode & stat.S_IWUSR:
if st.st_uid == uid:
matched = True
if mode & stat.S_IWGRP:
if st.st_uid == gid or st.st_uid in groups:
matched = True
if mode & stat.S_IWOTH:
matched = True
if not matched:
return False
if check & S_IXANY:
check -= S_IXANY
matched = False
if mode & stat.S_IXUSR:
if st.st_uid == uid:
matched = True
if mode & stat.S_IXGRP:
if st.st_uid == gid or st.st_uid in groups:
matched = True
if mode & stat.S_IXOTH:
matched = True
if not matched:
return False
if check:
raise NotImplementedError((orig, check))
return True