# 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)
import os
import re
import subprocess
import sys
from pathlib import Path, PurePath
import llnl.util.tty as tty
import spack.error
__all__ = ["Executable", "which", "ProcessError"]
[docs]
class Executable:
"""Class representing a program that can be run on the command line."""
def __init__(self, name):
file_path = str(Path(name))
if sys.platform != "win32" and name.startswith("."):
# pathlib strips the ./ from relative paths so it must be added back
file_path = os.path.join(".", file_path)
self.exe = [file_path]
self.default_env = {}
from spack.util.environment import EnvironmentModifications # no cycle
self.default_envmod = EnvironmentModifications()
self.returncode = None
if not self.exe:
raise ProcessError("Cannot construct executable for '%s'" % name)
[docs]
def add_default_arg(self, *args):
"""Add default argument(s) to the command."""
self.exe.extend(args)
[docs]
def add_default_env(self, key, value):
"""Set an environment variable when the command is run.
Parameters:
key: The environment variable to set
value: The value to set it to
"""
self.default_env[key] = value
[docs]
def add_default_envmod(self, envmod):
"""Set an EnvironmentModifications to use when the command is run."""
self.default_envmod.extend(envmod)
@property
def command(self):
"""The command-line string.
Returns:
str: The executable and default arguments
"""
return " ".join(self.exe)
@property
def name(self):
"""The executable name.
Returns:
str: The basename of the executable
"""
return PurePath(self.path).name
@property
def path(self):
"""The path to the executable.
Returns:
str: The path to the executable
"""
return str(PurePath(self.exe[0]))
def __call__(self, *args, **kwargs):
"""Run this executable in a subprocess.
Parameters:
*args (str): Command-line arguments to the executable to run
Keyword Arguments:
_dump_env (dict): Dict to be set to the environment actually
used (envisaged for testing purposes only)
env (dict or EnvironmentModifications): The environment with which
to run the executable
extra_env (dict or EnvironmentModifications): Extra items to add to
the environment (neither requires nor precludes env)
fail_on_error (bool): Raise an exception if the subprocess returns
an error. Default is True. The return code is available as
``exe.returncode``
ignore_errors (int or list): A list of error codes to ignore.
If these codes are returned, this process will not raise
an exception even if ``fail_on_error`` is set to ``True``
ignore_quotes (bool): If False, warn users that quotes are not needed
as Spack does not use a shell. Defaults to False.
timeout (int or float): The number of seconds to wait before killing
the child process
input: Where to read stdin from
output: Where to send stdout
error: Where to send stderr
Accepted values for input, output, and error:
* python streams, e.g. open Python file objects, or ``os.devnull``
* filenames, which will be automatically opened for writing
* ``str``, as in the Python string type. If you set these to ``str``,
output and error will be written to pipes and returned as a string.
If both ``output`` and ``error`` are set to ``str``, then one string
is returned containing output concatenated with error. Not valid
for ``input``
* ``str.split``, as in the ``split`` method of the Python string type.
Behaves the same as ``str``, except that value is also written to
``stdout`` or ``stderr``.
By default, the subprocess inherits the parent's file descriptors.
"""
def process_cmd_output(out, err):
result = None
if output in (str, str.split) or error in (str, str.split):
result = ""
if output in (str, str.split):
if sys.platform == "win32":
outstr = str(out.decode("ISO-8859-1"))
else:
outstr = str(out.decode("utf-8"))
result += outstr
if output is str.split:
sys.stdout.write(outstr)
if error in (str, str.split):
if sys.platform == "win32":
errstr = str(err.decode("ISO-8859-1"))
else:
errstr = str(err.decode("utf-8"))
result += errstr
if error is str.split:
sys.stderr.write(errstr)
return result
# Environment
env_arg = kwargs.get("env", None)
# Setup default environment
env = os.environ.copy() if env_arg is None else {}
self.default_envmod.apply_modifications(env)
env.update(self.default_env)
from spack.util.environment import EnvironmentModifications # no cycle
# Apply env argument
if isinstance(env_arg, EnvironmentModifications):
env_arg.apply_modifications(env)
elif env_arg:
env.update(env_arg)
# Apply extra env
extra_env = kwargs.get("extra_env", {})
if isinstance(extra_env, EnvironmentModifications):
extra_env.apply_modifications(env)
else:
env.update(extra_env)
if "_dump_env" in kwargs:
kwargs["_dump_env"].clear()
kwargs["_dump_env"].update(env)
fail_on_error = kwargs.pop("fail_on_error", True)
ignore_errors = kwargs.pop("ignore_errors", ())
ignore_quotes = kwargs.pop("ignore_quotes", False)
timeout = kwargs.pop("timeout", None)
# If they just want to ignore one error code, make it a tuple.
if isinstance(ignore_errors, int):
ignore_errors = (ignore_errors,)
input = kwargs.pop("input", None)
output = kwargs.pop("output", None)
error = kwargs.pop("error", None)
if input is str:
raise ValueError("Cannot use `str` as input stream.")
def streamify(arg, mode):
if isinstance(arg, str):
return open(arg, mode), True
elif arg in (str, str.split):
return subprocess.PIPE, False
else:
return arg, False
ostream, close_ostream = streamify(output, "w")
estream, close_estream = streamify(error, "w")
istream, close_istream = streamify(input, "r")
if not ignore_quotes:
quoted_args = [arg for arg in args if re.search(r'^".*"$|^\'.*\'$', arg)]
if quoted_args:
tty.warn(
"Quotes in command arguments can confuse scripts like" " configure.",
"The following arguments may cause problems when executed:",
str("\n".join([" " + arg for arg in quoted_args])),
"Quotes aren't needed because spack doesn't use a shell. "
"Consider removing them.",
"If multiple levels of quotation are required, use " "`ignore_quotes=True`.",
)
cmd = self.exe + list(args)
escaped_cmd = ["'%s'" % arg.replace("'", "'\"'\"'") for arg in cmd]
cmd_line_string = " ".join(escaped_cmd)
tty.debug(cmd_line_string)
try:
proc = subprocess.Popen(
cmd, stdin=istream, stderr=estream, stdout=ostream, env=env, close_fds=False
)
out, err = proc.communicate(timeout=timeout)
result = process_cmd_output(out, err)
rc = self.returncode = proc.returncode
if fail_on_error and rc != 0 and (rc not in ignore_errors):
long_msg = cmd_line_string
if result:
# If the output is not captured in the result, it will have
# been stored either in the specified files (e.g. if
# 'output' specifies a file) or written to the parent's
# stdout/stderr (e.g. if 'output' is not specified)
long_msg += "\n" + result
raise ProcessError("Command exited with status %d:" % proc.returncode, long_msg)
return result
except OSError as e:
message = "Command: " + cmd_line_string
if " " in self.exe[0]:
message += "\nDid you mean to add a space to the command?"
raise ProcessError("%s: %s" % (self.exe[0], e.strerror), message)
except subprocess.CalledProcessError as e:
if fail_on_error:
raise ProcessError(
str(e),
"\nExit status %d when invoking command: %s"
% (proc.returncode, cmd_line_string),
)
except subprocess.TimeoutExpired as te:
proc.kill()
out, err = proc.communicate()
result = process_cmd_output(out, err)
long_msg = cmd_line_string + f"\n{result}"
if fail_on_error:
raise ProcessTimeoutError(
f"\nProcess timed out after {timeout}s"
f"We expected the following command to run quickly but\
it did not, please report this as an issue: {long_msg}",
long_message=long_msg,
) from te
finally:
if close_ostream:
ostream.close()
if close_estream:
estream.close()
if close_istream:
istream.close()
def __eq__(self, other):
return hasattr(other, "exe") and self.exe == other.exe
def __neq__(self, other):
return not (self == other)
def __hash__(self):
return hash((type(self),) + tuple(self.exe))
def __repr__(self):
return "<exe: %s>" % self.exe
def __str__(self):
return " ".join(self.exe)
def which_string(*args, **kwargs):
"""Like ``which()``, but return a string instead of an ``Executable``."""
path = kwargs.get("path", os.environ.get("PATH", ""))
required = kwargs.get("required", False)
if isinstance(path, list):
paths = [Path(str(x)) for x in path]
if isinstance(path, str):
paths = [Path(x) for x in path.split(os.pathsep)]
def get_candidate_items(search_item):
if sys.platform == "win32" and not search_item.suffix:
return [search_item.parent / (search_item.name + ext) for ext in [".exe", ".bat"]]
return [Path(search_item)]
def add_extra_search_paths(paths):
with_parents = []
with_parents.extend(paths)
if sys.platform == "win32":
for p in paths:
if p.name == "bin":
with_parents.append(p.parent)
return with_parents
for search_item in args:
search_paths = []
search_paths.extend(paths)
if search_item.startswith("."):
# we do this because pathlib will strip any leading ./
search_paths.insert(0, Path.cwd())
search_paths = add_extra_search_paths(search_paths)
search_item = Path(search_item)
candidate_items = get_candidate_items(Path(search_item))
for candidate_item in candidate_items:
for directory in search_paths:
exe = directory / candidate_item
try:
if exe.is_file() and os.access(str(exe), os.X_OK):
return str(exe)
except OSError:
pass
if required:
raise CommandNotFoundError("spack requires '%s'. Make sure it is in your path." % args[0])
return None
[docs]
def which(*args, **kwargs):
"""Finds an executable in the path like command-line which.
If given multiple executables, returns the first one that is found.
If no executables are found, returns None.
Parameters:
*args (str): One or more executables to search for
Keyword Arguments:
path (list or str): The path to search. Defaults to ``PATH``
required (bool): If set to True, raise an error if executable not found
Returns:
Executable: The first executable that is found in the path
"""
exe = which_string(*args, **kwargs)
return Executable(exe) if exe else None
[docs]
class ProcessError(spack.error.SpackError):
"""ProcessErrors are raised when Executables exit with an error code."""
class ProcessTimeoutError(ProcessError):
"""ProcessTimeoutErrors are raised when Executable calls with a
specified timeout exceed that time"""
class CommandNotFoundError(spack.error.SpackError):
"""Raised when ``which()`` can't find a required executable."""