1 files changed, 246 insertions, 0 deletions
diff --git a/python/mozbuild/mozpack/path.py b/python/mozbuild/mozpack/path.py
new file mode 100644
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+++ b/python/mozbuild/mozpack/path.py
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+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+"""
+Like :py:mod:`os.path`, with a reduced set of functions, and with normalized path
+separators (always use forward slashes).
+Also contains a few additional utilities not found in :py:mod:`os.path`.
+"""
+
+import ctypes
+import os
+import posixpath
+import re
+import sys
+
+
+def normsep(path):
+    """
+    Normalize path separators, by using forward slashes instead of whatever
+    :py:const:`os.sep` is.
+    """
+    if os.sep != "/":
+        # Python 2 is happy to do things like byte_string.replace(u'foo',
+        # u'bar'), but not Python 3.
+        if isinstance(path, bytes):
+            path = path.replace(os.sep.encode("ascii"), b"/")
+        else:
+            path = path.replace(os.sep, "/")
+    if os.altsep and os.altsep != "/":
+        if isinstance(path, bytes):
+            path = path.replace(os.altsep.encode("ascii"), b"/")
+        else:
+            path = path.replace(os.altsep, "/")
+    return path
+
+
+def cargo_workaround(path):
+    unc = "//?/"
+    if path.startswith(unc):
+        return path[len(unc) :]
+    return path
+
+
+def relpath(path, start):
+    path = normsep(path)
+    start = normsep(start)
+    if sys.platform == "win32":
+        # os.path.relpath can't handle relative paths between UNC and non-UNC
+        # paths, so strip a //?/ prefix if present (bug 1581248)
+        path = cargo_workaround(path)
+        start = cargo_workaround(start)
+    try:
+        rel = os.path.relpath(path, start)
+    except ValueError:
+        # On Windows this can throw a ValueError if the two paths are on
+        # different drives. In that case, just return the path.
+        return abspath(path)
+    rel = normsep(rel)
+    return "" if rel == "." else rel
+
+
+def realpath(path):
+    return normsep(os.path.realpath(path))
+
+
+def abspath(path):
+    return normsep(os.path.abspath(path))
+
+
+def join(*paths):
+    return normsep(os.path.join(*paths))
+
+
+def normpath(path):
+    return posixpath.normpath(normsep(path))
+
+
+def dirname(path):
+    return posixpath.dirname(normsep(path))
+
+
+def commonprefix(paths):
+    return posixpath.commonprefix([normsep(path) for path in paths])
+
+
+def basename(path):
+    return os.path.basename(path)
+
+
+def splitext(path):
+    return posixpath.splitext(normsep(path))
+
+
+def split(path):
+    """
+    Return the normalized path as a list of its components.
+
+        ``split('foo/bar/baz')`` returns ``['foo', 'bar', 'baz']``
+    """
+    return normsep(path).split("/")
+
+
+def basedir(path, bases):
+    """
+    Given a list of directories (`bases`), return which one contains the given
+    path. If several matches are found, the deepest base directory is returned.
+
+        ``basedir('foo/bar/baz', ['foo', 'baz', 'foo/bar'])`` returns ``'foo/bar'``
+        (`'foo'` and `'foo/bar'` both match, but `'foo/bar'` is the deepest match)
+    """
+    path = normsep(path)
+    bases = [normsep(b) for b in bases]
+    if path in bases:
+        return path
+    for b in sorted(bases, reverse=True):
+        if b == "" or path.startswith(b + "/"):
+            return b
+
+
+re_cache = {}
+# Python versions < 3.7 return r'\/' for re.escape('/').
+if re.escape("/") == "/":
+    MATCH_STAR_STAR_RE = re.compile(r"(^|/)\\\*\\\*/")
+    MATCH_STAR_STAR_END_RE = re.compile(r"(^|/)\\\*\\\*$")
+else:
+    MATCH_STAR_STAR_RE = re.compile(r"(^|\\\/)\\\*\\\*\\\/")
+    MATCH_STAR_STAR_END_RE = re.compile(r"(^|\\\/)\\\*\\\*$")
+
+
+def match(path, pattern):
+    """
+    Return whether the given path matches the given pattern.
+    An asterisk can be used to match any string, including the null string, in
+    one part of the path:
+
+        ``foo`` matches ``*``, ``f*`` or ``fo*o``
+
+    However, an asterisk matching a subdirectory may not match the null string:
+
+        ``foo/bar`` does *not* match ``foo/*/bar``
+
+    If the pattern matches one of the ancestor directories of the path, the
+    patch is considered matching:
+
+        ``foo/bar`` matches ``foo``
+
+    Two adjacent asterisks can be used to match files and zero or more
+    directories and subdirectories.
+
+        ``foo/bar`` matches ``foo/**/bar``, or ``**/bar``
+    """
+    if not pattern:
+        return True
+    if pattern not in re_cache:
+        p = re.escape(pattern)
+        p = MATCH_STAR_STAR_RE.sub(r"\1(?:.+/)?", p)
+        p = MATCH_STAR_STAR_END_RE.sub(r"(?:\1.+)?", p)
+        p = p.replace(r"\*", "[^/]*") + "(?:/.*)?$"
+        re_cache[pattern] = re.compile(p)
+    return re_cache[pattern].match(path) is not None
+
+
+def rebase(oldbase, base, relativepath):
+    """
+    Return `relativepath` relative to `base` instead of `oldbase`.
+    """
+    if base == oldbase:
+        return relativepath
+    if len(base) < len(oldbase):
+        assert basedir(oldbase, [base]) == base
+        relbase = relpath(oldbase, base)
+        result = join(relbase, relativepath)
+    else:
+        assert basedir(base, [oldbase]) == oldbase
+        relbase = relpath(base, oldbase)
+        result = relpath(relativepath, relbase)
+    result = normpath(result)
+    if relativepath.endswith("/") and not result.endswith("/"):
+        result += "/"
+    return result
+
+
+def readlink(path):
+    if hasattr(os, "readlink"):
+        return normsep(os.readlink(path))
+
+    # Unfortunately os.path.realpath doesn't support symlinks on Windows, and os.readlink
+    # is only available on Windows with Python 3.2+. We have to resort to ctypes...
+
+    assert sys.platform == "win32"
+
+    CreateFileW = ctypes.windll.kernel32.CreateFileW
+    CreateFileW.argtypes = [
+        ctypes.wintypes.LPCWSTR,
+        ctypes.wintypes.DWORD,
+        ctypes.wintypes.DWORD,
+        ctypes.wintypes.LPVOID,
+        ctypes.wintypes.DWORD,
+        ctypes.wintypes.DWORD,
+        ctypes.wintypes.HANDLE,
+    ]
+    CreateFileW.restype = ctypes.wintypes.HANDLE
+
+    GENERIC_READ = 0x80000000
+    FILE_SHARE_READ = 0x00000001
+    OPEN_EXISTING = 3
+    FILE_FLAG_BACKUP_SEMANTICS = 0x02000000
+
+    handle = CreateFileW(
+        path,
+        GENERIC_READ,
+        FILE_SHARE_READ,
+        0,
+        OPEN_EXISTING,
+        FILE_FLAG_BACKUP_SEMANTICS,
+        0,
+    )
+    assert handle != 1, "Failed getting a handle to: {}".format(path)
+
+    MAX_PATH = 260
+
+    buf = ctypes.create_unicode_buffer(MAX_PATH)
+    GetFinalPathNameByHandleW = ctypes.windll.kernel32.GetFinalPathNameByHandleW
+    GetFinalPathNameByHandleW.argtypes = [
+        ctypes.wintypes.HANDLE,
+        ctypes.wintypes.LPWSTR,
+        ctypes.wintypes.DWORD,
+        ctypes.wintypes.DWORD,
+    ]
+    GetFinalPathNameByHandleW.restype = ctypes.wintypes.DWORD
+
+    FILE_NAME_NORMALIZED = 0x0
+
+    rv = GetFinalPathNameByHandleW(handle, buf, MAX_PATH, FILE_NAME_NORMALIZED)
+    assert rv != 0 and rv <= MAX_PATH, "Failed getting final path for: {}".format(path)
+
+    CloseHandle = ctypes.windll.kernel32.CloseHandle
+    CloseHandle.argtypes = [ctypes.wintypes.HANDLE]
+    CloseHandle.restype = ctypes.wintypes.BOOL
+
+    rv = CloseHandle(handle)
+    assert rv != 0, "Failed closing handle"
+
+    # Remove leading '\\?\' from the result.
+    return normsep(buf.value[4:])