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##############################################################################
# Copyright (c) 2013-2016, Lawrence Livermore National Security, LLC.
# Produced at the Lawrence Livermore National Laboratory.
#
# This file is part of Spack.
# Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
# LLNL-CODE-647188
#
# For details, see https://github.com/llnl/spack
# Please also see the LICENSE file for our notice and the LGPL.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License (as
# published by the Free Software Foundation) version 2.1, February 1999.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
# conditions of the GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
##############################################################################
import collections
import inspect
import json
import os
import os.path
import subprocess
class NameModifier(object):
def __init__(self, name, **kwargs):
self.name = name
self.args = {'name': name}
self.args.update(kwargs)
def update_args(self, **kwargs):
self.__dict__.update(kwargs)
self.args.update(kwargs)
class NameValueModifier(object):
def __init__(self, name, value, **kwargs):
self.name = name
self.value = value
self.separator = kwargs.get('separator', ':')
self.args = {'name': name, 'value': value, 'separator': self.separator}
self.args.update(kwargs)
def update_args(self, **kwargs):
self.__dict__.update(kwargs)
self.args.update(kwargs)
class SetEnv(NameValueModifier):
def execute(self):
os.environ[self.name] = str(self.value)
class UnsetEnv(NameModifier):
def execute(self):
# Avoid throwing if the variable was not set
os.environ.pop(self.name, None)
class SetPath(NameValueModifier):
def execute(self):
string_path = concatenate_paths(self.value, separator=self.separator)
os.environ[self.name] = string_path
class AppendPath(NameValueModifier):
def execute(self):
environment_value = os.environ.get(self.name, '')
directories = environment_value.split(
self.separator) if environment_value else []
directories.append(os.path.normpath(self.value))
os.environ[self.name] = self.separator.join(directories)
class PrependPath(NameValueModifier):
def execute(self):
environment_value = os.environ.get(self.name, '')
directories = environment_value.split(
self.separator) if environment_value else []
directories = [os.path.normpath(self.value)] + directories
os.environ[self.name] = self.separator.join(directories)
class RemovePath(NameValueModifier):
def execute(self):
environment_value = os.environ.get(self.name, '')
directories = environment_value.split(
self.separator) if environment_value else []
directories = [os.path.normpath(x) for x in directories
if x != os.path.normpath(self.value)]
os.environ[self.name] = self.separator.join(directories)
class EnvironmentModifications(object):
"""
Keeps track of requests to modify the current environment.
Each call to a method to modify the environment stores the extra
information on the caller in the request:
- 'filename' : filename of the module where the caller is defined
- 'lineno': line number where the request occurred
- 'context' : line of code that issued the request that failed
"""
def __init__(self, other=None):
"""
Initializes a new instance, copying commands from other if not None
Args:
other: another instance of EnvironmentModifications (optional)
"""
self.env_modifications = []
if other is not None:
self.extend(other)
def __iter__(self):
return iter(self.env_modifications)
def __len__(self):
return len(self.env_modifications)
def extend(self, other):
self._check_other(other)
self.env_modifications.extend(other.env_modifications)
@staticmethod
def _check_other(other):
if not isinstance(other, EnvironmentModifications):
raise TypeError(
'other must be an instance of EnvironmentModifications')
def _get_outside_caller_attributes(self):
stack = inspect.stack()
try:
_, filename, lineno, _, context, index = stack[2]
context = context[index].strip()
except Exception:
filename = 'unknown file'
lineno = 'unknown line'
context = 'unknown context'
args = {'filename': filename, 'lineno': lineno, 'context': context}
return args
def set(self, name, value, **kwargs):
"""
Stores in the current object a request to set an environment variable
Args:
name: name of the environment variable to be set
value: value of the environment variable
"""
kwargs.update(self._get_outside_caller_attributes())
item = SetEnv(name, value, **kwargs)
self.env_modifications.append(item)
def unset(self, name, **kwargs):
"""
Stores in the current object a request to unset an environment variable
Args:
name: name of the environment variable to be set
"""
kwargs.update(self._get_outside_caller_attributes())
item = UnsetEnv(name, **kwargs)
self.env_modifications.append(item)
def set_path(self, name, elts, **kwargs):
"""
Stores a request to set a path generated from a list.
Args:
name: name o the environment variable to be set.
elts: elements of the path to set.
"""
kwargs.update(self._get_outside_caller_attributes())
item = SetPath(name, elts, **kwargs)
self.env_modifications.append(item)
def append_path(self, name, path, **kwargs):
"""
Stores in the current object a request to append a path to a path list
Args:
name: name of the path list in the environment
path: path to be appended
"""
kwargs.update(self._get_outside_caller_attributes())
item = AppendPath(name, path, **kwargs)
self.env_modifications.append(item)
def prepend_path(self, name, path, **kwargs):
"""
Same as `append_path`, but the path is pre-pended
Args:
name: name of the path list in the environment
path: path to be pre-pended
"""
kwargs.update(self._get_outside_caller_attributes())
item = PrependPath(name, path, **kwargs)
self.env_modifications.append(item)
def remove_path(self, name, path, **kwargs):
"""
Stores in the current object a request to remove a path from a path
list
Args:
name: name of the path list in the environment
path: path to be removed
"""
kwargs.update(self._get_outside_caller_attributes())
item = RemovePath(name, path, **kwargs)
self.env_modifications.append(item)
def group_by_name(self):
"""
Returns a dict of the modifications grouped by variable name
Returns:
dict mapping the environment variable name to the modifications to
be done on it
"""
modifications = collections.defaultdict(list)
for item in self:
modifications[item.name].append(item)
return modifications
def clear(self):
"""
Clears the current list of modifications
"""
self.env_modifications.clear()
def apply_modifications(self):
"""
Applies the modifications and clears the list
"""
modifications = self.group_by_name()
# Apply modifications one variable at a time
for name, actions in sorted(modifications.items()):
for x in actions:
x.execute()
@staticmethod
def from_sourcing_files(*args, **kwargs):
"""
Creates an instance of EnvironmentModifications that, if executed,
has the same effect on the environment as sourcing the files passed as
parameters
Args:
*args: list of files to be sourced
Returns:
instance of EnvironmentModifications
"""
env = EnvironmentModifications()
# Check if the files are actually there
if not all(os.path.isfile(file) for file in args):
raise RuntimeError('trying to source non-existing files')
# Relevant kwd parameters and formats
info = dict(kwargs)
info.setdefault('shell', '/bin/bash')
info.setdefault('shell_options', '-c')
info.setdefault('source_command', 'source')
info.setdefault('suppress_output', '&> /dev/null')
info.setdefault('concatenate_on_success', '&&')
shell = '{shell}'.format(**info)
shell_options = '{shell_options}'.format(**info)
source_file = '{source_command} {file} {concatenate_on_success}'
dump_cmd = "import os, json; print json.dumps(dict(os.environ))"
dump_environment = 'python -c "%s"' % dump_cmd
# Construct the command that will be executed
command = [source_file.format(file=file, **info) for file in args]
command.append(dump_environment)
command = ' '.join(command)
command = [
shell,
shell_options,
command
]
# Try to source all the files,
proc = subprocess.Popen(
command, stdout=subprocess.PIPE, env=os.environ)
proc.wait()
if proc.returncode != 0:
raise RuntimeError('sourcing files returned a non-zero exit code')
output = ''.join([line for line in proc.stdout])
# Construct a dictionary with all the variables in the new environment
after_source_env = dict(json.loads(output))
this_environment = dict(os.environ)
# Filter variables that are not related to sourcing a file
to_be_filtered = 'SHLVL', '_', 'PWD', 'OLDPWD'
for d in after_source_env, this_environment:
for name in to_be_filtered:
d.pop(name, None)
# Fill the EnvironmentModifications instance
# New variables
new_variables = set(after_source_env) - set(this_environment)
for x in new_variables:
env.set(x, after_source_env[x])
# Variables that have been unset
unset_variables = set(this_environment) - set(after_source_env)
for x in unset_variables:
env.unset(x)
# Variables that have been modified
common_variables = set(
this_environment).intersection(set(after_source_env))
modified_variables = [x for x in common_variables
if this_environment[x] != after_source_env[x]]
def return_separator_if_any(first_value, second_value):
separators = ':', ';'
for separator in separators:
if separator in first_value and separator in second_value:
return separator
return None
for x in modified_variables:
current = this_environment[x]
modified = after_source_env[x]
sep = return_separator_if_any(current, modified)
if sep is None:
# We just need to set the variable to the new value
env.set(x, after_source_env[x])
else:
current_list = current.split(sep)
modified_list = modified.split(sep)
# Paths that have been removed
remove_list = [
ii for ii in current_list if ii not in modified_list]
# Check that nothing has been added in the middle of vurrent
# list
remaining_list = [
ii for ii in current_list if ii in modified_list]
start = modified_list.index(remaining_list[0])
end = modified_list.index(remaining_list[-1])
search = sep.join(modified_list[start:end + 1])
if search not in current:
# We just need to set the variable to the new value
env.set(x, after_source_env[x])
break
else:
try:
prepend_list = modified_list[:start]
except KeyError:
prepend_list = []
try:
append_list = modified_list[end + 1:]
except KeyError:
append_list = []
for item in remove_list:
env.remove_path(x, item)
for item in append_list:
env.append_path(x, item)
for item in prepend_list:
env.prepend_path(x, item)
return env
def concatenate_paths(paths, separator=':'):
"""
Concatenates an iterable of paths into a string of paths separated by
separator, defaulting to colon
Args:
paths: iterable of paths
separator: the separator to use, default ':'
Returns:
string
"""
return separator.join(str(item) for item in paths)
def set_or_unset_not_first(variable, changes, errstream):
"""
Check if we are going to set or unset something after other modifications
have already been requested
"""
indexes = [ii for ii, item in enumerate(changes)
if ii != 0 and type(item) in [SetEnv, UnsetEnv]]
if indexes:
good = '\t \t{context} at {filename}:{lineno}'
nogood = '\t--->\t{context} at {filename}:{lineno}'
message = "Suspicious requests to set or unset '{var}' found"
errstream(message.format(var=variable))
for ii, item in enumerate(changes):
print_format = nogood if ii in indexes else good
errstream(print_format.format(**item.args))
def validate(env, errstream):
"""
Validates the environment modifications to check for the presence of
suspicious patterns. Prompts a warning for everything that was found
Current checks:
- set or unset variables after other changes on the same variable
Args:
env: list of environment modifications
"""
modifications = env.group_by_name()
for variable, list_of_changes in sorted(modifications.items()):
set_or_unset_not_first(variable, list_of_changes, errstream)
def filter_environment_blacklist(env, variables):
"""
Generator that filters out any change to environment variables present in
the input list
Args:
env: list of environment modifications
variables: list of variable names to be filtered
Yields:
items in env if they are not in variables
"""
for item in env:
if item.name not in variables:
yield item
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