gh-117587: Add C implementation of os.path.abspath

Include/internal/pycore_fileutils.h

@@ -279,7 +279,8 @@ extern size_t _Py_find_basename(const wchar_t *filename);
 // Export for '_testinternalcapi' shared extension
 PyAPI_FUNC(wchar_t*) _Py_normpath(wchar_t *path, Py_ssize_t size);
 
-extern wchar_t *_Py_normpath_and_size(wchar_t *path, Py_ssize_t size, Py_ssize_t *length);
+extern wchar_t *_Py_normpath_and_size(wchar_t *path, Py_ssize_t size, Py_ssize_t start,
+ Py_ssize_t *length, int explicit_curdir);
 
 // The Windows Games API family does not provide these functions
 // so provide our own implementations. Remove them in case they get added

Lib/ctypes/__init__.py

@@ -380,7 +380,7 @@ def __init__(self, name, mode=DEFAULT_MODE, handle=None,
  import nt
  mode = nt._LOAD_LIBRARY_SEARCH_DEFAULT_DIRS
  if '/' in name or '\\' in name:
- self._name = nt._getfullpathname(self._name)
+ self._name = nt._path_abspath(self._name)
  mode |= nt._LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR
 
  class _FuncPtr(_CFuncPtr):

Lib/ntpath.py

@@ -554,36 +554,47 @@ def normpath(path):
  return prefix + sep.join(comps)
 
 
-def _abspath_fallback(path):
- """Return the absolute version of a path as a fallback function in case
- `nt._getfullpathname` is not available or raises OSError. See bpo-31047 for
- more.
-
- """
-
- path = os.fspath(path)
- if not isabs(path):
- if isinstance(path, bytes):
- cwd = os.getcwdb()
- else:
- cwd = os.getcwd()
- path = join(cwd, path)
- return normpath(path)
-
 # Return an absolute path.
 try:
- from nt import _getfullpathname
+ from nt import _path_abspath
 
 except ImportError: # not running on Windows - mock up something sensible
- abspath = _abspath_fallback
+ def abspath(path):
+ """Return the absolute version of a path."""
+ path = os.fspath(path)
+ if not isabs(path):
+ if isinstance(path, bytes):
+ path = join(os.getcwdb(), path)
+ else:
+ path = join(os.getcwd(), path)
+ return normpath(path)
 
 else: # use native Windows method on Windows
  def abspath(path):
  """Return the absolute version of a path."""
  try:
- return _getfullpathname(normpath(path))
+ return _path_abspath(path)
  except (OSError, ValueError):
- return _abspath_fallback(path)
+ # See gh-75230, handle outside for cleaner traceback
+ pass
+ path = os.fspath(path)
+ if not isabs(path):
+ if isinstance(path, bytes):
+ sep = b'/'
+ cwd = os.getcwdb()
+ else:
+ sep = '/'
+ cwd = os.getcwd()
+ drive, root, path = splitroot(path)
+ if drive and drive != splitroot(cwd)[0]:
+ try:
+ path = join(_path_abspath(drive), path)
+ except (OSError, ValueError):
+ # Invalid drive \x00: on Windows; assume root directory
+ path = drive + sep + path
+ else:
+ path = join(cwd, root + path)
+ return normpath(path)
 
 try:
  from nt import _findfirstfile, _getfinalpathname, readlink as _nt_readlink

Lib/posixpath.py

@@ -372,16 +372,19 @@ def normpath(path):
  return path or dot
 
 
-def abspath(path):
- """Return an absolute path."""
- path = os.fspath(path)
- if isinstance(path, bytes):
- if not path.startswith(b'/'):
- path = join(os.getcwdb(), path)
- else:
- if not path.startswith('/'):
- path = join(os.getcwd(), path)
- return normpath(path)
+try:
+ from posix import _path_abspath as abspath
+except ImportError:
+ def abspath(path):
+ """Return an absolute path."""
+ path = os.fspath(path)
+ if isinstance(path, bytes):
+ if not path.startswith(b'/'):
+ path = join(os.getcwdb(), path)
+ else:
+ if not path.startswith('/'):
+ path = join(os.getcwd(), path)
+ return normpath(path)
 
 
 # Return a canonical path (i.e. the absolute location of a file on the

Lib/test/test_ctypes/test_loading.py

@@ -185,11 +185,11 @@ def should_fail(command):
  should_pass("windll.kernel32.SetDllDirectoryW(None); WinDLL('_sqlite3.dll', winmode=0)")
 
  # Full path load without DLL_LOAD_DIR shouldn't find dependency
- should_fail("WinDLL(nt._getfullpathname('_sqlite3.dll'), " +
+ should_fail("WinDLL(nt._path_abspath('_sqlite3.dll'), " +
  "winmode=nt._LOAD_LIBRARY_SEARCH_SYSTEM32)")
 
  # Full path load with DLL_LOAD_DIR should succeed
- should_pass("WinDLL(nt._getfullpathname('_sqlite3.dll'), " +
+ should_pass("WinDLL(nt._path_abspath('_sqlite3.dll'), " +
  "winmode=nt._LOAD_LIBRARY_SEARCH_SYSTEM32|" +
  "nt._LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR)")
 

Lib/test/test_ntpath.py

@@ -347,13 +347,15 @@ def test_normpath(self):
 
  tester("ntpath.normpath('..')", r'..')
  tester("ntpath.normpath('.')", r'.')
+ tester("ntpath.normpath('c:.')", 'c:')
  tester("ntpath.normpath('')", r'.')
  tester("ntpath.normpath('/')", '\\')
  tester("ntpath.normpath('c:/')", 'c:\\')
  tester("ntpath.normpath('/../.././..')", '\\')
  tester("ntpath.normpath('c:/../../..')", 'c:\\')
  tester("ntpath.normpath('../.././..')", r'..\..\..')
  tester("ntpath.normpath('K:../.././..')", r'K:..\..\..')
+ tester("ntpath.normpath('./a/b')", r'a\b')
  tester("ntpath.normpath('C:////a/b')", r'C:\a\b')
  tester("ntpath.normpath('//machine/share//a/b')", r'\\machine\share\a\b')
 
@@ -806,6 +808,9 @@ def test_abspath(self):
  tester('ntpath.abspath("C:\\spam. . .")', "C:\\spam")
  tester('ntpath.abspath("C:/nul")', "\\\\.\\nul")
  tester('ntpath.abspath("C:\\nul")', "\\\\.\\nul")
+ self.assertTrue(ntpath.isabs(ntpath.abspath("C:spam")))
+ self.assertTrue(ntpath.isabs(ntpath.abspath("C:\x00")))
+ self.assertTrue(ntpath.isabs(ntpath.abspath("\x00:spam")))
  tester('ntpath.abspath("//..")', "\\\\")
  tester('ntpath.abspath("//../")', "\\\\..\\")
  tester('ntpath.abspath("//../..")', "\\\\..\\")
@@ -836,6 +841,20 @@ def test_abspath(self):
  tester('ntpath.abspath("")', cwd_dir)
  tester('ntpath.abspath(" ")', cwd_dir + "\\ ")
  tester('ntpath.abspath("?")', cwd_dir + "\\?")
+ tester('ntpath.abspath("con")', r"\\.\con")
+ # bpo-45354: Windows 11 changed MS-DOS device name handling
+ if sys.getwindowsversion()[:3] < (10, 0, 22000):
+ tester('ntpath.abspath("./con")', r"\\.\con")
+ tester('ntpath.abspath("foo/../con")', r"\\.\con")
+ tester('ntpath.abspath("con/foo/..")', r"\\.\con")
+ tester('ntpath.abspath("con/.")', r"\\.\con")
+ else:
+ tester('ntpath.abspath("./con")', cwd_dir + r"\con")
+ tester('ntpath.abspath("foo/../con")', cwd_dir + r"\con")
+ tester('ntpath.abspath("con/foo/..")', cwd_dir + r"\con")
+ tester('ntpath.abspath("con/.")', cwd_dir + r"\con")
+ tester('ntpath.abspath("./Z:spam")', cwd_dir + r"\Z:spam")
+ tester('ntpath.abspath("spam/../Z:eggs")', cwd_dir + r"\Z:eggs")
  drive, _ = ntpath.splitdrive(cwd_dir)
  tester('ntpath.abspath("/abc/")', drive + "\\abc")
 

Lib/test/test_posixpath.py

@@ -293,6 +293,8 @@ def test_fast_paths_in_use(self):
  self.assertFalse(inspect.isfunction(os.path.splitroot))
  self.assertTrue(os.path.normpath is posix._path_normpath)
  self.assertFalse(inspect.isfunction(os.path.normpath))
+ self.assertTrue(os.path.abspath is posix._path_abspath)
+ self.assertFalse(inspect.isfunction(os.path.abspath))
 
  def test_expanduser(self):
  self.assertEqual(posixpath.expanduser("foo"), "foo")
@@ -382,6 +384,7 @@ def test_expanduser_pwd2(self):
  ("///..//./foo/.//bar", "/foo/bar"),
  (".", "."),
  (".//.", "."),
+ ("./foo/bar", "foo/bar"),
  ("..", ".."),
  ("../", ".."),
  ("../foo", "../foo"),
@@ -689,19 +692,21 @@ def test_realpath_unreadable_symlink(self):
  os.chmod(ABSTFN, 0o755, follow_symlinks=False)
  os.unlink(ABSTFN)
 
+ @skip_if_ABSTFN_contains_backslash
  def test_relpath(self):
- (real_getcwd, os.getcwd) = (os.getcwd, lambda: r"/home/user/bar")
  try:
-curdir = os.path.split(os.getcwd())[-1]
+ os.mkdir(ABSTFN)
  self.assertRaises(TypeError, posixpath.relpath, None)
  self.assertRaises(ValueError, posixpath.relpath, "")
  self.assertEqual(posixpath.relpath("a"), "a")
  self.assertEqual(posixpath.relpath(posixpath.abspath("a")), "a")
  self.assertEqual(posixpath.relpath("a/b"), "a/b")
  self.assertEqual(posixpath.relpath("../a/b"), "../a/b")
- self.assertEqual(posixpath.relpath("a", "../b"), "../"+curdir+"/a")
- self.assertEqual(posixpath.relpath("a/b", "../c"),
- "../"+curdir+"/a/b")
+ with os_helper.change_cwd(ABSTFN):
+ curdir = basename(ABSTFN)
+ self.assertEqual(posixpath.relpath("a", "../b"), "../"+curdir+"/a")
+ self.assertEqual(posixpath.relpath("a/b", "../c"),
+ "../"+curdir+"/a/b")
  self.assertEqual(posixpath.relpath("a", "b/c"), "../../a")
  self.assertEqual(posixpath.relpath("a", "a"), ".")
  self.assertEqual(posixpath.relpath("/foo/bar/bat", "/x/y/z"), '../../../foo/bar/bat')
@@ -714,21 +719,23 @@ def test_relpath(self):
  self.assertEqual(posixpath.relpath("/a", "/a"), '.')
  self.assertEqual(posixpath.relpath("/a/b", "/a/b"), '.')
  finally:
-os.getcwd = real_getcwd
+safe_rmdir(ABSTFN)
 
+ @skip_if_ABSTFN_contains_backslash
  def test_relpath_bytes(self):
- (real_getcwdb, os.getcwdb) = (os.getcwdb, lambda: br"/home/user/bar")
  try:
-curdir = os.path.split(os.getcwdb())[-1]
+ os.mkdir(ABSTFN)
  self.assertRaises(ValueError, posixpath.relpath, b"")
  self.assertEqual(posixpath.relpath(b"a"), b"a")
  self.assertEqual(posixpath.relpath(posixpath.abspath(b"a")), b"a")
  self.assertEqual(posixpath.relpath(b"a/b"), b"a/b")
  self.assertEqual(posixpath.relpath(b"../a/b"), b"../a/b")
- self.assertEqual(posixpath.relpath(b"a", b"../b"),
- b"../"+curdir+b"/a")
- self.assertEqual(posixpath.relpath(b"a/b", b"../c"),
- b"../"+curdir+b"/a/b")
+ with os_helper.change_cwd(ABSTFN):
+ curdir = os.fsencode(basename(ABSTFN))
+ self.assertEqual(posixpath.relpath(b"a", b"../b"),
+ b"../"+curdir+b"/a")
+ self.assertEqual(posixpath.relpath(b"a/b", b"../c"),
+ b"../"+curdir+b"/a/b")
  self.assertEqual(posixpath.relpath(b"a", b"b/c"), b"../../a")
  self.assertEqual(posixpath.relpath(b"a", b"a"), b".")
  self.assertEqual(posixpath.relpath(b"/foo/bar/bat", b"/x/y/z"), b'../../../foo/bar/bat')
@@ -744,7 +751,7 @@ def test_relpath_bytes(self):
  self.assertRaises(TypeError, posixpath.relpath, b"bytes", "str")
  self.assertRaises(TypeError, posixpath.relpath, "str", b"bytes")
  finally:
-os.getcwdb = real_getcwdb
+safe_rmdir(ABSTFN)
 
  def test_commonpath(self):
  def check(paths, expected):

Misc/NEWS.d/next/Core and Builtins/2024-04-13-18-00-18.gh-issue-117587.52AB27.rst

@@ -0,0 +1 @@
+Speedup :func:`os.path.abspath` with a native implementation.