Source code for spack.directives

# Copyright 2013-2022 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)

"""This package contains directives that can be used within a package.

Directives are functions that can be called inside a package
definition to modify the package, for example:

    class OpenMpi(Package):

``provides`` and ``depends_on`` are spack directives.

The available directives are:

  * ``conflicts``
  * ``depends_on``
  * ``extends``
  * ``patch``
  * ``provides``
  * ``resource``
  * ``variant``
  * ``version``

import functools
import os.path
import re
from typing import List, Set  # novm

import six

import llnl.util.lang
import llnl.util.tty.color
from llnl.util.compat import Sequence

import spack.error
import spack.patch
import spack.spec
import spack.url
import spack.variant
from spack.dependency import Dependency, canonical_deptype, default_deptype
from spack.fetch_strategy import from_kwargs
from spack.resource import Resource
from spack.version import Version, VersionChecksumError

__all__ = ['DirectiveError', 'DirectiveMeta', 'version', 'conflicts', 'depends_on',
           'extends', 'provides', 'patch', 'variant', 'resource']

#: These are variant names used by Spack internally; packages can't use them
reserved_names = ['patches', 'dev_path']

#: Names of possible directives. This list is populated elsewhere in the file.
directive_names = []

_patch_order_index = 0

def make_when_spec(value):
    """Create a ``Spec`` that indicates when a directive should be applied.

    Directives with ``when`` specs, e.g.:

        patch('foo.patch', when='@4.5.1:')
        depends_on('mpi', when='+mpi')
        depends_on('readline', when=sys.platform() != 'darwin')

    are applied conditionally depending on the value of the ``when``
    keyword argument.  Specifically:

      1. If the ``when`` argument is ``True``, the directive is always applied
      2. If it is ``False``, the directive is never applied
      3. If it is a ``Spec`` string, it is applied when the package's
         concrete spec satisfies the ``when`` spec.

    The first two conditions are useful for the third example case above.
    It allows package authors to include directives that are conditional
    at package definition time, in additional to ones that are evaluated
    as part of concretization.

        value (spack.spec.Spec or bool): a conditional Spec or a constant ``bool``
           value indicating when a directive should be applied.

    if isinstance(value, spack.spec.Spec):
        return value

    # Unsatisfiable conditions are discarded by the caller, and never
    # added to the package class
    if value is False:
        return False

    # If there is no constraint, the directive should always apply;
    # represent this by returning the unconstrained `Spec()`, which is
    # always satisfied.
    if value is None or value is True:
        return spack.spec.Spec()

    # This is conditional on the spec
    return spack.spec.Spec(value)

[docs]class DirectiveMeta(type): """Flushes the directives that were temporarily stored in the staging area into the package. """ # Set of all known directives _directive_dict_names = set() # type: Set[str] _directives_to_be_executed = [] # type: List[str] _when_constraints_from_context = [] # type: List[str] def __new__(cls, name, bases, attr_dict): # Initialize the attribute containing the list of directives # to be executed. Here we go reversed because we want to execute # commands: # 1. in the order they were defined # 2. following the MRO attr_dict['_directives_to_be_executed'] = [] for base in reversed(bases): try: directive_from_base = base._directives_to_be_executed attr_dict['_directives_to_be_executed'].extend( directive_from_base) except AttributeError: # The base class didn't have the required attribute. # Continue searching pass # De-duplicates directives from base classes attr_dict['_directives_to_be_executed'] = [ x for x in llnl.util.lang.dedupe( attr_dict['_directives_to_be_executed'])] # Move things to be executed from module scope (where they # are collected first) to class scope if DirectiveMeta._directives_to_be_executed: attr_dict['_directives_to_be_executed'].extend( DirectiveMeta._directives_to_be_executed) DirectiveMeta._directives_to_be_executed = [] return super(DirectiveMeta, cls).__new__( cls, name, bases, attr_dict) def __init__(cls, name, bases, attr_dict): # The instance is being initialized: if it is a package we must ensure # that the directives are called to set it up. if 'spack.pkg' in cls.__module__: # Ensure the presence of the dictionaries associated # with the directives for d in DirectiveMeta._directive_dict_names: setattr(cls, d, {}) # Lazily execute directives for directive in cls._directives_to_be_executed: directive(cls) # Ignore any directives executed *within* top-level # directives by clearing out the queue they're appended to DirectiveMeta._directives_to_be_executed = [] super(DirectiveMeta, cls).__init__(name, bases, attr_dict)
[docs] @staticmethod def push_to_context(when_spec): """Add a spec to the context constraints.""" DirectiveMeta._when_constraints_from_context.append(when_spec)
[docs] @staticmethod def pop_from_context(): """Pop the last constraint from the context""" return DirectiveMeta._when_constraints_from_context.pop()
[docs] @staticmethod def directive(dicts=None): """Decorator for Spack directives. Spack directives allow you to modify a package while it is being defined, e.g. to add version or dependency information. Directives are one of the key pieces of Spack's package "language", which is embedded in python. Here's an example directive: .. code-block:: python @directive(dicts='versions') version(pkg, ...): ... This directive allows you write: .. code-block:: python class Foo(Package): version(...) The ``@directive`` decorator handles a couple things for you: 1. Adds the class scope (pkg) as an initial parameter when called, like a class method would. This allows you to modify a package from within a directive, while the package is still being defined. 2. It automatically adds a dictionary called "versions" to the package so that you can refer to pkg.versions. The ``(dicts='versions')`` part ensures that ALL packages in Spack will have a ``versions`` attribute after they're constructed, and that if no directive actually modified it, it will just be an empty dict. This is just a modular way to add storage attributes to the Package class, and it's how Spack gets information from the packages to the core. """ global directive_names if isinstance(dicts, six.string_types): dicts = (dicts, ) if not isinstance(dicts, Sequence): message = "dicts arg must be list, tuple, or string. Found {0}" raise TypeError(message.format(type(dicts))) # Add the dictionary names if not already there DirectiveMeta._directive_dict_names |= set(dicts) # This decorator just returns the directive functions def _decorator(decorated_function): directive_names.append(decorated_function.__name__) @functools.wraps(decorated_function) def _wrapper(*args, **kwargs): # Inject when arguments from the context if DirectiveMeta._when_constraints_from_context: # Check that directives not yet supporting the when= argument # are not used inside the context manager if decorated_function.__name__ == 'version': msg = ('directive "{0}" cannot be used within a "when"' ' context since it does not support a "when=" ' 'argument') msg = msg.format(decorated_function.__name__) raise DirectiveError(msg) when_constraints = [ spack.spec.Spec(x) for x in DirectiveMeta._when_constraints_from_context ] if kwargs.get('when'): when_constraints.append(spack.spec.Spec(kwargs['when'])) when_spec = spack.spec.merge_abstract_anonymous_specs( *when_constraints ) kwargs['when'] = when_spec # If any of the arguments are executors returned by a # directive passed as an argument, don't execute them # lazily. Instead, let the called directive handle them. # This allows nested directive calls in packages. The # caller can return the directive if it should be queued. def remove_directives(arg): directives = DirectiveMeta._directives_to_be_executed if isinstance(arg, (list, tuple)): # Descend into args that are lists or tuples for a in arg: remove_directives(a) else: # Remove directives args from the exec queue remove = next( (d for d in directives if d is arg), None) if remove is not None: directives.remove(remove) # Nasty, but it's the best way I can think of to avoid # side effects if directive results are passed as args remove_directives(args) remove_directives(list(kwargs.values())) # A directive returns either something that is callable on a # package or a sequence of them result = decorated_function(*args, **kwargs) # if it is not a sequence make it so values = result if not isinstance(values, Sequence): values = (values, ) DirectiveMeta._directives_to_be_executed.extend(values) # wrapped function returns same result as original so # that we can nest directives return result return _wrapper return _decorator
directive = DirectiveMeta.directive
[docs]@directive('versions') def version(ver, checksum=None, **kwargs): """Adds a version and, if appropriate, metadata for fetching its code. The ``version`` directives are aggregated into a ``versions`` dictionary attribute with ``Version`` keys and metadata values, where the metadata is stored as a dictionary of ``kwargs``. The ``dict`` of arguments is turned into a valid fetch strategy for code packages later. See ``spack.fetch_strategy.for_package_version()``. Keyword Arguments: deprecated (bool): whether or not this version is deprecated """ def _execute_version(pkg): if checksum is not None: if hasattr(pkg, 'has_code') and not pkg.has_code: raise VersionChecksumError( "{0}: Checksums not allowed in no-code packages" "(see '{1}' version).".format(, ver)) kwargs['checksum'] = checksum # Store kwargs for the package to later with a fetch_strategy. pkg.versions[Version(ver)] = kwargs return _execute_version
def _depends_on(pkg, spec, when=None, type=default_deptype, patches=None): when_spec = make_when_spec(when) if not when_spec: return dep_spec = spack.spec.Spec(spec) if == raise CircularReferenceError( "Package '%s' cannot depend on itself." % type = canonical_deptype(type) conditions = pkg.dependencies.setdefault(, {}) # call this patches here for clarity -- we want patch to be a list, # but the caller doesn't have to make it one. # Note: we cannot check whether a package is virtual in a directive # because directives are run as part of class instantiation, and specs # instantiate the package class as part of the `virtual` check. # To be technical, specs only instantiate the package class as part of the # virtual check if the provider index hasn't been created yet. # TODO: There could be a cache warming strategy that would allow us to # ensure `Spec.virtual` is a valid thing to call in a directive. # For now, we comment out the following check to allow for virtual packages # with package files. # if patches and dep_spec.virtual: # raise DependencyPatchError("Cannot patch a virtual dependency.") # ensure patches is a list if patches is None: patches = [] elif not isinstance(patches, (list, tuple)): patches = [patches] # auto-call patch() directive on any strings in patch list patches = [patch(p) if isinstance(p, six.string_types) else p for p in patches] assert all(callable(p) for p in patches) # this is where we actually add the dependency to this package if when_spec not in conditions: dependency = Dependency(pkg, dep_spec, type=type) conditions[when_spec] = dependency else: dependency = conditions[when_spec] dependency.spec.constrain(dep_spec, deps=False) dependency.type |= set(type) # apply patches to the dependency for execute_patch in patches: execute_patch(dependency)
[docs]@directive('conflicts') def conflicts(conflict_spec, when=None, msg=None): """Allows a package to define a conflict. Currently, a "conflict" is a concretized configuration that is known to be non-valid. For example, a package that is known not to be buildable with intel compilers can declare:: conflicts('%intel') To express the same constraint only when the 'foo' variant is activated:: conflicts('%intel', when='+foo') Args: conflict_spec (spack.spec.Spec): constraint defining the known conflict when (spack.spec.Spec): optional constraint that triggers the conflict msg (str): optional user defined message """ def _execute_conflicts(pkg): # If when is not specified the conflict always holds when_spec = make_when_spec(when) if not when_spec: return # Save in a list the conflicts and the associated custom messages when_spec_list = pkg.conflicts.setdefault(conflict_spec, []) when_spec_list.append((when_spec, msg)) return _execute_conflicts
[docs]@directive(('dependencies')) def depends_on(spec, when=None, type=default_deptype, patches=None): """Creates a dict of deps with specs defining when they apply. Args: spec (spack.spec.Spec or str): the package and constraints depended on when (spack.spec.Spec or str): when the dependent satisfies this, it has the dependency represented by ``spec`` type (str or tuple): str or tuple of legal Spack deptypes patches (typing.Callable or list): single result of ``patch()`` directive, a ``str`` to be passed to ``patch``, or a list of these This directive is to be used inside a Package definition to declare that the package requires other packages to be built first. @see The section "Dependency specs" in the Spack Packaging Guide. """ def _execute_depends_on(pkg): _depends_on(pkg, spec, when=when, type=type, patches=patches) return _execute_depends_on
[docs]@directive(('extendees', 'dependencies')) def extends(spec, type=('build', 'run'), **kwargs): """Same as depends_on, but allows symlinking into dependency's prefix tree. This is for Python and other language modules where the module needs to be installed into the prefix of the Python installation. Spack handles this by installing modules into their own prefix, but allowing ONE module version to be symlinked into a parent Python install at a time, using ``spack activate``. keyword arguments can be passed to extends() so that extension packages can pass parameters to the extendee's extension mechanism. """ def _execute_extends(pkg): when = kwargs.get('when') when_spec = make_when_spec(when) if not when_spec: return _depends_on(pkg, spec, when=when, type=type) spec_obj = spack.spec.Spec(spec) pkg.extendees[] = (spec_obj, kwargs) return _execute_extends
[docs]@directive('provided') def provides(*specs, **kwargs): """Allows packages to provide a virtual dependency. If a package provides 'mpi', other packages can declare that they depend on "mpi", and spack can use the providing package to satisfy the dependency. """ def _execute_provides(pkg): when = kwargs.get('when') when_spec = make_when_spec(when) if not when_spec: return # ``when`` specs for ``provides()`` need a name, as they are used # to build the ProviderIndex. = for string in specs: for provided_spec in spack.spec.parse(string): if == raise CircularReferenceError( "Package '%s' cannot provide itself.") if provided_spec not in pkg.provided: pkg.provided[provided_spec] = set() pkg.provided[provided_spec].add(when_spec) return _execute_provides
[docs]@directive('patches') def patch(url_or_filename, level=1, when=None, working_dir=".", **kwargs): """Packages can declare patches to apply to source. You can optionally provide a when spec to indicate that a particular patch should only be applied when the package's spec meets certain conditions (e.g. a particular version). Args: url_or_filename (str): url or relative filename of the patch level (int): patch level (as in the patch shell command) when (spack.spec.Spec): optional anonymous spec that specifies when to apply the patch working_dir (str): dir to change to before applying Keyword Args: sha256 (str): sha256 sum of the patch, used to verify the patch (only required for URL patches) archive_sha256 (str): sha256 sum of the *archive*, if the patch is compressed (only required for compressed URL patches) """ def _execute_patch(pkg_or_dep): pkg = pkg_or_dep if isinstance(pkg, Dependency): pkg = pkg.pkg if hasattr(pkg, 'has_code') and not pkg.has_code: raise UnsupportedPackageDirective( 'Patches are not allowed in {0}: package has no code.'. format( when_spec = make_when_spec(when) if not when_spec: return # If this spec is identical to some other, then append this # patch to the existing list. cur_patches = pkg_or_dep.patches.setdefault(when_spec, []) global _patch_order_index ordering_key = (, _patch_order_index) _patch_order_index += 1 if '://' in url_or_filename: patch = spack.patch.UrlPatch( pkg, url_or_filename, level, working_dir, ordering_key=ordering_key, **kwargs) else: patch = spack.patch.FilePatch( pkg, url_or_filename, level, working_dir, ordering_key=ordering_key) cur_patches.append(patch) return _execute_patch
[docs]@directive('variants') def variant( name, default=None, description='', values=None, multi=None, validator=None, when=None, sticky=False ): """Define a variant for the package. Packager can specify a default value as well as a text description. Args: name (str): name of the variant default (str or bool): default value for the variant, if not specified otherwise the default will be False for a boolean variant and 'nothing' for a multi-valued variant description (str): description of the purpose of the variant values (tuple or typing.Callable): either a tuple of strings containing the allowed values, or a callable accepting one value and returning True if it is valid multi (bool): if False only one value per spec is allowed for this variant validator (typing.Callable): optional group validator to enforce additional logic. It receives the package name, the variant name and a tuple of values and should raise an instance of SpackError if the group doesn't meet the additional constraints when (spack.spec.Spec, bool): optional condition on which the variant applies sticky (bool): the variant should not be changed by the concretizer to find a valid concrete spec. Raises: DirectiveError: if arguments passed to the directive are invalid """ def format_error(msg, pkg): msg += " @*r{{[{0}, variant '{1}']}}" return llnl.util.tty.color.colorize(msg.format(, name)) if name in reserved_names: def _raise_reserved_name(pkg): msg = "The name '%s' is reserved by Spack" % name raise DirectiveError(format_error(msg, pkg)) return _raise_reserved_name # Ensure we have a sequence of allowed variant values, or a # predicate for it. if values is None: if str(default).upper() in ('TRUE', 'FALSE'): values = (True, False) else: values = lambda x: True # The object defining variant values might supply its own defaults for # all the other arguments. Ensure we have no conflicting definitions # in place. for argument in ('default', 'multi', 'validator'): # TODO: we can consider treating 'default' differently from other # TODO: attributes and let a packager decide whether to use the fluent # TODO: interface or the directive argument if hasattr(values, argument) and locals()[argument] is not None: def _raise_argument_error(pkg): msg = "Remove specification of {0} argument: it is handled " \ "by an attribute of the 'values' argument" raise DirectiveError(format_error(msg.format(argument), pkg)) return _raise_argument_error # Allow for the object defining the allowed values to supply its own # default value and group validator, say if it supports multiple values. default = getattr(values, 'default', default) validator = getattr(values, 'validator', validator) multi = getattr(values, 'multi', bool(multi)) # Here we sanitize against a default value being either None # or the empty string, as the former indicates that a default # was not set while the latter will make the variant unparsable # from the command line if default is None or default == '': def _raise_default_not_set(pkg): if default is None: msg = "either a default was not explicitly set, " \ "or 'None' was used" elif default == '': msg = "the default cannot be an empty string" raise DirectiveError(format_error(msg, pkg)) return _raise_default_not_set description = str(description).strip() def _execute_variant(pkg): when_spec = make_when_spec(when) when_specs = [when_spec] if not re.match(spack.spec.identifier_re, name): directive = 'variant' msg = "Invalid variant name in {0}: '{1}'" raise DirectiveError(directive, msg.format(, name)) if name in pkg.variants: # We accumulate when specs, but replace the rest of the variant # with the newer values _, orig_when = pkg.variants[name] when_specs += orig_when pkg.variants[name] = (spack.variant.Variant( name, default, description, values, multi, validator, sticky ), when_specs) return _execute_variant
[docs]@directive('resources') def resource(**kwargs): """Define an external resource to be fetched and staged when building the package. Based on the keywords present in the dictionary the appropriate FetchStrategy will be used for the resource. Resources are fetched and staged in their own folder inside spack stage area, and then moved into the stage area of the package that needs them. List of recognized keywords: * 'when' : (optional) represents the condition upon which the resource is needed * 'destination' : (optional) path where to move the resource. This path must be relative to the main package stage area. * 'placement' : (optional) gives the possibility to fine tune how the resource is moved into the main package stage area. """ def _execute_resource(pkg): when = kwargs.get('when') when_spec = make_when_spec(when) if not when_spec: return destination = kwargs.get('destination', "") placement = kwargs.get('placement', None) # Check if the path is relative if os.path.isabs(destination): message = ('The destination keyword of a resource directive ' 'can\'t be an absolute path.\n') message += "\tdestination : '{dest}\n'".format(dest=destination) raise RuntimeError(message) # Check if the path falls within the main package stage area test_path = 'stage_folder_root' normalized_destination = os.path.normpath( os.path.join(test_path, destination) ) # Normalized absolute path if test_path not in normalized_destination: message = ("The destination folder of a resource must fall " "within the main package stage directory.\n") message += "\tdestination : '{dest}'\n".format(dest=destination) raise RuntimeError(message) resources = pkg.resources.setdefault(when_spec, []) name = kwargs.get('name') fetcher = from_kwargs(**kwargs) resources.append(Resource(name, fetcher, destination, placement)) return _execute_resource
[docs]class DirectiveError(spack.error.SpackError): """This is raised when something is wrong with a package directive."""
class CircularReferenceError(DirectiveError): """This is raised when something depends on itself.""" class DependencyPatchError(DirectiveError): """Raised for errors with patching dependencies.""" class UnsupportedPackageDirective(DirectiveError): """Raised when an invalid or unsupported package directive is specified."""