Remove **kwargs from function signatures in llnl.util.filesystem (#34804)

Since we dropped support for Python 2.7, we can embrace using keyword only arguments 
for many functions in Spack that use **kwargs in the function signature. Here this is done 
for the llnl.util.filesystem module.

There were a couple of bugs lurking in the code related to typo-like errors when retrieving
from kwargs. Those have been fixed as well.

lib/spack/llnl/util/filesystem.py

@@ -17,6 +17,7 @@
 import tempfile
 from contextlib import contextmanager
 from sys import platform as _platform
+from typing import Callable, List, Match, Optional, Tuple, Union
 
 from llnl.util import tty
 from llnl.util.lang import dedupe, memoized
@@ -214,7 +215,16 @@ def same_path(path1, path2):
     return norm1 == norm2
 
 
-def filter_file(regex, repl, *filenames, **kwargs):
+def filter_file(
+    regex: str,
+    repl: Union[str, Callable[[Match], str]],
+    *filenames: str,
+    string: bool = False,
+    backup: bool = False,
+    ignore_absent: bool = False,
+    start_at: Optional[str] = None,
+    stop_at: Optional[str] = None,
+) -> None:
     r"""Like sed, but uses python regular expressions.
 
     Filters every line of each file through regex and replaces the file
@@ -226,12 +236,10 @@ def filter_file(regex, repl, *filenames, **kwargs):
     can contain ``\1``, ``\2``, etc. to represent back-substitution
     as sed would allow.
 
-    Parameters:
+    Args:
         regex (str): The regular expression to search for
         repl (str): The string to replace matches with
         *filenames: One or more files to search and replace
-
-    Keyword Arguments:
         string (bool): Treat regex as a plain string. Default it False
         backup (bool): Make backup file(s) suffixed with ``~``. Default is False
         ignore_absent (bool): Ignore any files that don't exist.
@@ -246,17 +254,11 @@ def filter_file(regex, repl, *filenames, **kwargs):
             file is copied verbatim. Default is to filter until the end of the
             file.
     """
-    string = kwargs.get("string", False)
-    backup = kwargs.get("backup", False)
-    ignore_absent = kwargs.get("ignore_absent", False)
-    start_at = kwargs.get("start_at", None)
-    stop_at = kwargs.get("stop_at", None)
-
     # Allow strings to use \1, \2, etc. for replacement, like sed
     if not callable(repl):
         unescaped = repl.replace(r"\\", "\\")
 
-        def replace_groups_with_groupid(m):
+        def replace_groups_with_groupid(m: Match) -> str:
             def groupid_to_group(x):
                 return m.group(int(x.group(1)))
 
@@ -290,15 +292,14 @@ def groupid_to_group(x):
         shutil.copy(filename, tmp_filename)
 
         try:
-            # To avoid translating line endings (\n to \r\n and vis versa)
+            # Open as a text file and filter until the end of the file is
+            # reached, or we found a marker in the line if it was specified
+            #
+            # To avoid translating line endings (\n to \r\n and vice-versa)
             # we force os.open to ignore translations and use the line endings
             # the file comes with
-            extra_kwargs = {"errors": "surrogateescape", "newline": ""}
+            with open(tmp_filename, mode="r", errors="surrogateescape", newline="") as input_file:
-
+                with open(filename, mode="w", errors="surrogateescape", newline="") as output_file:
-            # Open as a text file and filter until the end of the file is
-            # reached or we found a marker in the line if it was specified
-            with open(tmp_filename, mode="r", **extra_kwargs) as input_file:
-                with open(filename, mode="w", **extra_kwargs) as output_file:
                     do_filtering = start_at is None
                     # Using iter and readline is a workaround needed not to
                     # disable input_file.tell(), which will happen if we call
@@ -321,10 +322,10 @@ def groupid_to_group(x):
             # If we stopped filtering at some point, reopen the file in
             # binary mode and copy verbatim the remaining part
             if current_position and stop_at:
-                with open(tmp_filename, mode="rb") as input_file:
+                with open(tmp_filename, mode="rb") as input_binary_buffer:
-                    input_file.seek(current_position)
+                    input_binary_buffer.seek(current_position)
-                    with open(filename, mode="ab") as output_file:
+                    with open(filename, mode="ab") as output_binary_buffer:
-                        output_file.writelines(input_file.readlines())
+                        output_binary_buffer.writelines(input_binary_buffer.readlines())
 
         except BaseException:
             # clean up the original file on failure.
@@ -343,8 +344,26 @@ class FileFilter(object):
     def __init__(self, *filenames):
         self.filenames = filenames
 
-    def filter(self, regex, repl, **kwargs):
+    def filter(
-        return filter_file(regex, repl, *self.filenames, **kwargs)
+        self,
+        regex: str,
+        repl: Union[str, Callable[[Match], str]],
+        string: bool = False,
+        backup: bool = False,
+        ignore_absent: bool = False,
+        start_at: Optional[str] = None,
+        stop_at: Optional[str] = None,
+    ) -> None:
+        return filter_file(
+            regex,
+            repl,
+            *self.filenames,
+            string=string,
+            backup=backup,
+            ignore_absent=ignore_absent,
+            start_at=start_at,
+            stop_at=stop_at,
+        )
 
 
 def change_sed_delimiter(old_delim, new_delim, *filenames):
@@ -652,7 +671,13 @@ def resolve_link_target_relative_to_the_link(link):
 
 
 @system_path_filter
-def copy_tree(src, dest, symlinks=True, ignore=None, _permissions=False):
+def copy_tree(
+    src: str,
+    dest: str,
+    symlinks: bool = True,
+    ignore: Optional[Callable[[str], bool]] = None,
+    _permissions: bool = False,
+):
     """Recursively copy an entire directory tree rooted at *src*.
 
     If the destination directory *dest* does not already exist, it will
@@ -710,7 +735,7 @@ def copy_tree(src, dest, symlinks=True, ignore=None, _permissions=False):
             abs_src,
             abs_dest,
             order="pre",
-            follow_symlinks=not symlinks,
+            follow_links=not symlinks,
             ignore=ignore,
             follow_nonexisting=True,
         ):
@@ -812,45 +837,32 @@ def chgrp_if_not_world_writable(path, group):
         chgrp(path, group)
 
 
-def mkdirp(*paths, **kwargs):
+def mkdirp(
+    *paths: str,
+    mode: Optional[int] = None,
+    group: Optional[Union[str, int]] = None,
+    default_perms: Optional[str] = None,
+):
     """Creates a directory, as well as parent directories if needed.
 
     Arguments:
-        paths (str): paths to create with mkdirp
+        paths: paths to create with mkdirp
-
+        mode: optional permissions to set on the created directory -- use OS default
-    Keyword Aguments:
+            if not provided
-        mode (permission bits or None): optional permissions to set
+        group: optional group for permissions of final created directory -- use OS
-            on the created directory -- use OS default if not provided
+            default if not provided. Only used if world write permissions are not set
-        group (group name or None): optional group for permissions of
+        default_perms: one of 'parents' or 'args'. The default permissions that are set for
-            final created directory -- use OS default if not provided. Only
+            directories that are not themselves an argument for mkdirp. 'parents' means
-            used if world write permissions are not set
+            intermediate directories get the permissions of their direct parent directory,
-        default_perms (str or None): one of 'parents' or 'args'. The default permissions
+            'args' means intermediate get the same permissions specified in the arguments to
-            that are set for directories that are not themselves an argument
-            for mkdirp. 'parents' means intermediate directories get the
-            permissions of their direct parent directory, 'args' means
-            intermediate get the same permissions specified in the arguments to
             mkdirp -- default value is 'args'
     """
-    mode = kwargs.get("mode", None)
+    default_perms = default_perms or "args"
-    group = kwargs.get("group", None)
-    default_perms = kwargs.get("default_perms", "args")
     paths = path_to_os_path(*paths)
     for path in paths:
         if not os.path.exists(path):
             try:
-                # detect missing intermediate folders
+                last_parent, intermediate_folders = longest_existing_parent(path)
-                intermediate_folders = []
-                last_parent = ""
-
-                intermediate_path = os.path.dirname(path)
-
-                while intermediate_path:
-                    if os.path.exists(intermediate_path):
-                        last_parent = intermediate_path
-                        break
-
-                    intermediate_folders.append(intermediate_path)
-                    intermediate_path = os.path.dirname(intermediate_path)
 
                 # create folders
                 os.makedirs(path)
@@ -884,7 +896,10 @@ def mkdirp(*paths, **kwargs):
                         os.chmod(intermediate_path, intermediate_mode)
                     if intermediate_group is not None:
                         chgrp_if_not_world_writable(intermediate_path, intermediate_group)
-                        os.chmod(intermediate_path, intermediate_mode)  # reset sticky bit after
+                        if intermediate_mode is not None:
+                            os.chmod(
+                                intermediate_path, intermediate_mode
+                            )  # reset sticky bit after
 
             except OSError as e:
                 if e.errno != errno.EEXIST or not os.path.isdir(path):
@@ -893,6 +908,27 @@ def mkdirp(*paths, **kwargs):
             raise OSError(errno.EEXIST, "File already exists", path)
 
 
+def longest_existing_parent(path: str) -> Tuple[str, List[str]]:
+    """Return the last existing parent and a list of all intermediate directories
+    to be created for the directory passed as input.
+
+    Args:
+        path: directory to be created
+    """
+    # detect missing intermediate folders
+    intermediate_folders = []
+    last_parent = ""
+    intermediate_path = os.path.dirname(path)
+    while intermediate_path:
+        if os.path.lexists(intermediate_path):
+            last_parent = intermediate_path
+            break
+
+        intermediate_folders.append(intermediate_path)
+        intermediate_path = os.path.dirname(intermediate_path)
+    return last_parent, intermediate_folders
+
+
 @system_path_filter
 def force_remove(*paths):
     """Remove files without printing errors.  Like ``rm -f``, does NOT
@@ -906,8 +942,8 @@ def force_remove(*paths):
 
 @contextmanager
 @system_path_filter
-def working_dir(dirname, **kwargs):
+def working_dir(dirname: str, *, create: bool = False):
-    if kwargs.get("create", False):
+    if create:
         mkdirp(dirname)
 
     orig_dir = os.getcwd()
@@ -1118,7 +1154,16 @@ def can_access(file_name):
 
 
 @system_path_filter
-def traverse_tree(source_root, dest_root, rel_path="", **kwargs):
+def traverse_tree(
+    source_root: str,
+    dest_root: str,
+    rel_path: str = "",
+    *,
+    order: str = "pre",
+    ignore: Optional[Callable[[str], bool]] = None,
+    follow_nonexisting: bool = True,
+    follow_links: bool = False,
+):
     """Traverse two filesystem trees simultaneously.
 
     Walks the LinkTree directory in pre or post order.  Yields each
@@ -1150,16 +1195,11 @@ def traverse_tree(source_root, dest_root, rel_path="", **kwargs):
             ``src`` that do not exit in ``dest``. Default is True
         follow_links (bool): Whether to descend into symlinks in ``src``
     """
-    follow_nonexisting = kwargs.get("follow_nonexisting", True)
-    follow_links = kwargs.get("follow_link", False)
-
-    # Yield in pre or post order?
-    order = kwargs.get("order", "pre")
     if order not in ("pre", "post"):
         raise ValueError("Order must be 'pre' or 'post'.")
 
     # List of relative paths to ignore under the src root.
-    ignore = kwargs.get("ignore", None) or (lambda filename: False)
+    ignore = ignore or (lambda filename: False)
 
     # Don't descend into ignored directories
     if ignore(rel_path):
@@ -1186,7 +1226,15 @@ def traverse_tree(source_root, dest_root, rel_path="", **kwargs):
             # When follow_nonexisting isn't set, don't descend into dirs
             # in source that do not exist in dest
             if follow_nonexisting or os.path.exists(dest_child):
-                tuples = traverse_tree(source_root, dest_root, rel_child, **kwargs)
+                tuples = traverse_tree(
+                    source_root,
+                    dest_root,
+                    rel_child,
+                    order=order,
+                    ignore=ignore,
+                    follow_nonexisting=follow_nonexisting,
+                    follow_links=follow_links,
+                )
                 for t in tuples:
                     yield t
 
@@ -2573,13 +2621,15 @@ def keep_modification_time(*filenames):
 
 
 @contextmanager
-def temporary_dir(*args, **kwargs):
+def temporary_dir(
+    suffix: Optional[str] = None, prefix: Optional[str] = None, dir: Optional[str] = None
+):
     """Create a temporary directory and cd's into it. Delete the directory
     on exit.
 
     Takes the same arguments as tempfile.mkdtemp()
     """
-    tmp_dir = tempfile.mkdtemp(*args, **kwargs)
+    tmp_dir = tempfile.mkdtemp(suffix=suffix, prefix=prefix, dir=dir)
     try:
         with working_dir(tmp_dir):
             yield tmp_dir