Source code for spack.util.path

# Copyright 2013-2024 Lawrence Livermore National Security, LLC and other
# Spack Project Developers. See the top-level COPYRIGHT file for details.
# SPDX-License-Identifier: (Apache-2.0 OR MIT)

"""Utilities for managing paths in Spack.

TODO: this is really part of spack.config. Consolidate it.
import contextlib
import getpass
import os
import re
import subprocess
import sys
import tempfile
from datetime import date

import llnl.util.tty as tty
from llnl.util.lang import memoized

import spack.util.spack_yaml as syaml

__all__ = ["substitute_config_variables", "substitute_path_variables", "canonicalize_path"]

def architecture():
    # break circular import
    import spack.platforms
    import spack.spec

    host_platform =
    host_os = host_platform.operating_system("default_os")
    host_target ="default_target")

    return spack.spec.ArchSpec((str(host_platform), str(host_os), str(host_target)))

def get_user():
    # User pwd where available because it accounts for effective uids when using ksu and similar
        # user pwd for unix systems
        import pwd

        return pwd.getpwuid(os.geteuid()).pw_name
    except ImportError:
        # fallback on getpass
        return getpass.getuser()

# return value for replacements with no match
NOMATCH = object()

# Substitutions to perform
def replacements():
    # break circular imports
    import spack.environment as ev
    import spack.paths

    arch = architecture()

    return {
        "spack": lambda: spack.paths.prefix,
        "user": lambda: get_user(),
        "tempdir": lambda: tempfile.gettempdir(),
        "user_cache_path": lambda: spack.paths.user_cache_path,
        "architecture": lambda: arch,
        "arch": lambda: arch,
        "platform": lambda: arch.platform,
        "operating_system": lambda: arch.os,
        "os": lambda: arch.os,
        "target": lambda:,
        "target_family": lambda:,
        "date": lambda:"%Y-%m-%d"),
        "env": lambda: ev.active_environment().path if ev.active_environment() else NOMATCH,

# This is intended to be longer than the part of the install path
# spack generates from the root path we give it.  Included in the
# estimate:
#   os-arch      ->   30
#   compiler     ->   30
#   package name ->   50   (longest is currently 47 characters)
#   version      ->   20
#   hash         ->   32
#   buffer       ->  138
#  ---------------------
#   total        ->  300

#: Padded paths comprise directories with this name (or some prefix of it). :
#: It starts with two underscores to make it unlikely that prefix matches would
#: include some other component of the intallation path.
SPACK_PATH_PADDING_CHARS = "__spack_path_placeholder__"

def win_exe_ext():
    return r"(?:\.bat|\.exe)"

def sanitize_filename(filename: str) -> str:
    Replaces unsupported characters (for the host) in a filename with underscores.

    Criteria for legal files based on

        filename: string containing filename to be created on the host filesystem

        filename that can be created on the host filesystem
    if sys.platform != "win32":
        # Only disallow null bytes and directory separators.
        return re.sub("[\0/]", "_", filename)

    # On Windows, things are more involved.
    # NOTE: this is incomplete, missing reserved names
    return re.sub(r'[\x00-\x1F\x7F"*/:<>?\\|]', "_", filename)

def get_system_path_max():
    # Choose a conservative default
    sys_max_path_length = 256
    if sys.platform == "win32":
        sys_max_path_length = 260
            path_max_proc = subprocess.Popen(
                ["getconf", "PATH_MAX", "/"], stdout=subprocess.PIPE, stderr=subprocess.STDOUT
            proc_output = str(path_max_proc.communicate()[0].decode())
            sys_max_path_length = int(proc_output)
        except (ValueError, subprocess.CalledProcessError, OSError):
                "Unable to find system max path length, using: {0}".format(sys_max_path_length)

    return sys_max_path_length

[docs] def substitute_config_variables(path): """Substitute placeholders into paths. Spack allows paths in configs to have some placeholders, as follows: - $env The active Spack environment. - $spack The Spack instance's prefix - $tempdir Default temporary directory returned by tempfile.gettempdir() - $user The current user's username - $user_cache_path The user cache directory (~/.spack, unless overridden) - $architecture The spack architecture triple for the current system - $arch The spack architecture triple for the current system - $platform The spack platform for the current system - $os The OS of the current system - $operating_system The OS of the current system - $target The ISA target detected for the system - $target_family The family of the target detected for the system - $date The current date (YYYY-MM-DD) These are substituted case-insensitively into the path, and users can use either ``$var`` or ``${var}`` syntax for the variables. $env is only replaced if there is an active environment, and should only be used in environment yaml files. """ _replacements = replacements() # Look up replacements def repl(match): m = key = m.strip("${}").lower() repl = _replacements.get(key, lambda: m)() return m if repl is NOMATCH else str(repl) # Replace $var or ${var}. return re.sub(r"(\$\w+\b|\$\{\w+\})", repl, path)
[docs] def substitute_path_variables(path): """Substitute config vars, expand environment vars, expand user home.""" path = substitute_config_variables(path) path = os.path.expandvars(path) path = os.path.expanduser(path) return path
def _get_padding_string(length): spack_path_padding_size = len(SPACK_PATH_PADDING_CHARS) num_reps = int(length / (spack_path_padding_size + 1)) extra_chars = length % (spack_path_padding_size + 1) reps_list = [SPACK_PATH_PADDING_CHARS for i in range(num_reps)] reps_list.append(SPACK_PATH_PADDING_CHARS[:extra_chars]) return os.path.sep.join(reps_list) def add_padding(path, length): """Add padding subdirectories to path until total is length characters Returns the padded path. If path is length - 1 or more characters long, returns path. If path is length - 1 characters, warns that it is not padding to length Assumes path does not have a trailing path separator""" padding_length = length - len(path) if padding_length == 1: # The only 1 character addition we can make to a path is `/` # Spack internally runs normpath, so `foo/` will be reduced to `foo` # Even if we removed this behavior from Spack, the user could normalize # the path, removing the additional `/`. # Because we can't expect one character of padding to show up in the # resulting binaries, we warn the user and do not pad by a single char tty.warn("Cannot pad path by exactly one character.") if padding_length <= 0: return path # we subtract 1 from the padding_length to account for the path separator # coming from os.path.join below padding = _get_padding_string(padding_length - 1) return os.path.join(path, padding)
[docs] def canonicalize_path(path, default_wd=None): """Same as substitute_path_variables, but also take absolute path. If the string is a yaml object with file annotations, make absolute paths relative to that file's directory. Otherwise, use ``default_wd`` if specified, otherwise ``os.getcwd()`` Arguments: path (str): path being converted as needed Returns: (str): An absolute path with path variable substitution """ # Get file in which path was written in case we need to make it absolute # relative to that path. filename = None if isinstance(path, syaml.syaml_str): filename = os.path.dirname( assert == path = substitute_path_variables(path) if not os.path.isabs(path): if filename: path = os.path.join(filename, path) else: base = default_wd or os.getcwd() path = os.path.join(base, path) tty.debug("Using working directory %s as base for abspath" % base) return os.path.normpath(path)
def longest_prefix_re(string, capture=True): """Return a regular expression that matches a the longest possible prefix of string. i.e., if the input string is ``the_quick_brown_fox``, then:: m = re.compile(longest_prefix('the_quick_brown_fox')) m.match('the_').group(1) == 'the_' m.match('the_quick').group(1) == 'the_quick' m.match('the_quick_brown_fox').group(1) == 'the_quick_brown_fox' m.match('the_xquick_brown_fox').group(1) == 'the_' m.match('the_quickx_brown_fox').group(1) == 'the_quick' """ if len(string) < 2: return string return "(%s%s%s?)" % ( "" if capture else "?:", string[0], longest_prefix_re(string[1:], capture=False), ) #: regex cache for padding_filter function _filter_re = None def padding_filter(string): """Filter used to reduce output from path padding in log output. This turns paths like this: /foo/bar/__spack_path_placeholder__/__spack_path_placeholder__/... Into paths like this: /foo/bar/[padded-to-512-chars]/... Where ``padded-to-512-chars`` indicates that the prefix was padded with placeholders until it hit 512 characters. The actual value of this number depends on what the `install_tree``'s ``padded_length`` is configured to. For a path to match and be filtered, the placeholder must appear in its entirety at least one time. e.g., "/spack/" would not be filtered, but "/__spack_path_placeholder__/spack/" would be. Note that only the first padded path in the string is filtered. """ global _filter_re pad = SPACK_PATH_PADDING_CHARS if not _filter_re: longest_prefix = longest_prefix_re(pad) regex = ( r"((?:/[^/\s]*)*?)" # zero or more leading non-whitespace path components r"(/{pad})+" # the padding string repeated one or more times r"(/{longest_prefix})?(?=/)" # trailing prefix of padding as path component ) regex = regex.replace("/", re.escape(os.sep)) regex = regex.format(pad=pad, longest_prefix=longest_prefix) _filter_re = re.compile(regex) def replacer(match): return "%s%s[padded-to-%d-chars]" % (, os.sep, len( return _filter_re.sub(replacer, string) @contextlib.contextmanager def filter_padding(): """Context manager to safely disable path padding in all Spack output. This is needed because Spack's debug output gets extremely long when we use a long padded installation path. """ import spack.config padding = spack.config.get("config:install_tree:padded_length", None) if padding: # filter out all padding from the intsall command output with tty.output_filter(padding_filter): yield else: yield # no-op: don't filter unless padding is actually enabled def debug_padded_filter(string, level=1): """ Return string, path padding filtered if debug level and not windows Args: string (str): string containing path level (int): maximum debug level value for filtering (e.g., 1 means filter path padding if the current debug level is 0 or 1 but return the original string if it is 2 or more) Returns (str): filtered string if current debug level does not exceed level and not windows; otherwise, unfiltered string """ if sys.platform == "win32": return string return padding_filter(string) if tty.debug_level() <= level else string