Source code for spack.variant

# 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)

"""The variant module contains data structures that are needed to manage
variants both in packages and in specs.

import functools
import inspect
import itertools
import re

import six
from six import StringIO

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

import spack.directives
import spack.error as error
from spack.util.string import comma_or

special_variant_values = [None, 'none', '*']

[docs]class Variant(object): """Represents a variant in a package, as declared in the variant directive. """ def __init__( self, name, default, description, values=(True, False), multi=False, validator=None, sticky=False ): """Initialize a package variant. Args: name (str): name of the variant default (str): default value for the variant in case nothing has been specified description (str): purpose of the variant values (sequence): sequence of allowed values or a callable accepting a single value as argument and returning True if the value is good, False otherwise multi (bool): whether multiple CSV are allowed validator (callable): optional callable used to enforce additional logic on the set of values being validated sticky (bool): if true the variant is set to the default value at concretization time """ = name self.default = default self.description = str(description) self.values = None if values == '*': # wildcard is a special case to make it easy to say any value is ok self.single_value_validator = lambda x: True elif isinstance(values, type): # supplying a type means any value *of that type* def isa_type(v): try: values(v) return True except ValueError: return False self.single_value_validator = isa_type if callable(values): # If 'values' is a callable, assume it is a single value # validator and reset the values to be explicit during debug self.single_value_validator = values else: # Otherwise, assume values is the set of allowed explicit values self.values = _flatten(values) self.single_value_validator = lambda x: x in tuple(self.values) self.multi = multi self.group_validator = validator self.sticky = sticky
[docs] def validate_or_raise(self, vspec, pkg=None): """Validate a variant spec against this package variant. Raises an exception if any error is found. Args: vspec (Variant): instance to be validated pkg (spack.package.Package): the package that required the validation, if available Raises: InconsistentValidationError: if `` !=`` MultipleValuesInExclusiveVariantError: if ``vspec`` has multiple values but ``self.multi == False`` InvalidVariantValueError: if ``vspec.value`` contains invalid values """ # Check the name of the variant if != raise InconsistentValidationError(vspec, self) # Check the values of the variant spec value = vspec.value if isinstance(vspec.value, (bool, str)): value = (vspec.value,) # If the value is exclusive there must be at most one if not self.multi and len(value) != 1: raise MultipleValuesInExclusiveVariantError(vspec, pkg) # Check and record the values that are not allowed not_allowed_values = [ x for x in value if x != '*' and self.single_value_validator(x) is False ] if not_allowed_values: raise InvalidVariantValueError(self, not_allowed_values, pkg) # Validate the group of values if needed if self.group_validator is not None and value != ('*',): self.group_validator(,, value)
@property def allowed_values(self): """Returns a string representation of the allowed values for printing purposes Returns: str: representation of the allowed values """ # Join an explicit set of allowed values if self.values is not None: v = tuple(str(x) for x in self.values) return ', '.join(v) # In case we were given a single-value validator # print the docstring docstring = inspect.getdoc(self.single_value_validator) v = docstring if docstring else '' return v
[docs] def make_default(self): """Factory that creates a variant holding the default value. Returns: MultiValuedVariant or SingleValuedVariant or BoolValuedVariant: instance of the proper variant """ return self.make_variant(self.default)
[docs] def make_variant(self, value): """Factory that creates a variant holding the value passed as a parameter. Args: value: value that will be hold by the variant Returns: MultiValuedVariant or SingleValuedVariant or BoolValuedVariant: instance of the proper variant """ return self.variant_cls(, value)
@property def variant_cls(self): """Proper variant class to be used for this configuration.""" if self.multi: return MultiValuedVariant elif self.values == (True, False): return BoolValuedVariant return SingleValuedVariant def __eq__(self, other): return ( == and self.default == other.default and self.values == other.values and self.multi == other.multi and self.single_value_validator == other.single_value_validator and self.group_validator == other.group_validator) def __ne__(self, other): return not self == other
[docs]def implicit_variant_conversion(method): """Converts other to type(self) and calls method(self, other) Args: method: any predicate method that takes another variant as an argument Returns: decorated method """ @functools.wraps(method) def convert(self, other): # We don't care if types are different as long as I can convert # other to type(self) try: other = type(self)(, other._original_value) except (error.SpecError, ValueError): return False return method(self, other) return convert
def _flatten(values): """Flatten instances of _ConditionalVariantValues for internal representation""" if isinstance(values, DisjointSetsOfValues): return values flattened = [] for item in values: if isinstance(item, _ConditionalVariantValues): flattened.extend(item) else: flattened.append(item) # There are parts of the variant checking mechanism that expect to find tuples # here, so it is important to convert the type once we flattened the values. return tuple(flattened)
[docs]@lang.lazy_lexicographic_ordering class AbstractVariant(object): """A variant that has not yet decided who it wants to be. It behaves like a multi valued variant which **could** do things. This kind of variant is generated during parsing of expressions like ``foo=bar`` and differs from multi valued variants because it will satisfy any other variant with the same name. This is because it **could** do it if it grows up to be a multi valued variant with the right set of values. """ def __init__(self, name, value): = name # Stores 'value' after a bit of massaging # done by the property setter self._value = None self._original_value = None # Invokes property setter self.value = value
[docs] @staticmethod def from_node_dict(name, value): """Reconstruct a variant from a node dict.""" if isinstance(value, list): # read multi-value variants in and be faithful to the YAML mvar = MultiValuedVariant(name, ()) mvar._value = tuple(value) mvar._original_value = mvar._value return mvar elif str(value).upper() == 'TRUE' or str(value).upper() == 'FALSE': return BoolValuedVariant(name, value) return SingleValuedVariant(name, value)
[docs] def yaml_entry(self): """Returns a key, value tuple suitable to be an entry in a yaml dict. Returns: tuple: (name, value_representation) """ return, list(self.value)
@property def value(self): """Returns a tuple of strings containing the values stored in the variant. Returns: tuple: values stored in the variant """ return self._value @value.setter def value(self, value): self._value_setter(value) def _value_setter(self, value): # Store the original value self._original_value = value if not isinstance(value, (tuple, list)): # Store a tuple of CSV string representations # Tuple is necessary here instead of list because the # values need to be hashed value = re.split(r'\s*,\s*', str(value)) for val in special_variant_values: if val in value and len(value) > 1: msg = "'%s' cannot be combined with other variant" % val msg += " values." raise InvalidVariantValueCombinationError(msg) # With multi-value variants it is necessary # to remove duplicates and give an order # to a set self._value = tuple(sorted(set(value))) def _cmp_iter(self): yield value = self._value if not isinstance(value, tuple): value = (value,) value = tuple(str(x) for x in value) yield value
[docs] def copy(self): """Returns an instance of a variant equivalent to self Returns: AbstractVariant: a copy of self >>> a = MultiValuedVariant('foo', True) >>> b = a.copy() >>> assert a == b >>> assert a is not b """ return type(self)(, self._original_value)
[docs] @implicit_variant_conversion def satisfies(self, other): """Returns true if `` ==``, because any value that other holds and is not in self yet **could** be added. Args: other: constraint to be met for the method to return True Returns: bool: True or False """ # If names are different then `self` does not satisfy `other` # (`foo=bar` will never satisfy `baz=bar`) return ==
[docs] @implicit_variant_conversion def compatible(self, other): """Returns True if self and other are compatible, False otherwise. As there is no semantic check, two VariantSpec are compatible if either they contain the same value or they are both multi-valued. Args: other: instance against which we test compatibility Returns: bool: True or False """ # If names are different then `self` is not compatible with `other` # (`foo=bar` is incompatible with `baz=bar`) return ==
[docs] @implicit_variant_conversion def constrain(self, other): """Modify self to match all the constraints for other if both instances are multi-valued. Returns True if self changed, False otherwise. Args: other: instance against which we constrain self Returns: bool: True or False """ if != raise ValueError('variants must have the same name') old_value = self.value values = list(sorted(set(self.value + other.value))) # If we constraint wildcard by another value, just take value if '*' in values and len(values) > 1: values.remove('*') self.value = ','.join(values) return old_value != self.value
def __contains__(self, item): return item in self._value def __repr__(self): cls = type(self) return '{0.__name__}({1}, {2})'.format( cls, repr(, repr(self._original_value) ) def __str__(self): return '{0}={1}'.format(, ','.join(str(x) for x in self.value) )
[docs]class MultiValuedVariant(AbstractVariant): """A variant that can hold multiple values at once."""
[docs] @implicit_variant_conversion def satisfies(self, other): """Returns true if `` ==`` and ``other.value`` is a strict subset of self. Does not try to validate. Args: other: constraint to be met for the method to return True Returns: bool: True or False """ super_sat = super(MultiValuedVariant, self).satisfies(other) if not super_sat: return False if '*' in other or '*' in self: return True # allow prefix find on patches if == 'patches': return all(any(w.startswith(v) for w in self.value) for v in other.value) # Otherwise we want all the values in `other` to be also in `self` return all(v in self.value for v in other.value)
[docs] def append(self, value): """Add another value to this multi-valued variant.""" self._value = tuple(sorted((value,) + self._value)) self._original_value = ",".join(self._value)
def __str__(self): # Special-case patches to not print the full 64 character hashes if == 'patches': values_str = ','.join(x[:7] for x in self.value) else: values_str = ','.join(str(x) for x in self.value) return '{0}={1}'.format(, values_str)
[docs]class SingleValuedVariant(AbstractVariant): """A variant that can hold multiple values, but one at a time.""" def _value_setter(self, value): # Treat the value as a multi-valued variant super(SingleValuedVariant, self)._value_setter(value) # Then check if there's only a single value if len(self._value) != 1: raise MultipleValuesInExclusiveVariantError(self, None) self._value = str(self._value[0]) def __str__(self): return '{0}={1}'.format(, self.value)
[docs] @implicit_variant_conversion def satisfies(self, other): abstract_sat = super(SingleValuedVariant, self).satisfies(other) return abstract_sat and (self.value == other.value or other.value == '*' or self.value == '*')
[docs] def compatible(self, other): return self.satisfies(other)
[docs] @implicit_variant_conversion def constrain(self, other): if != raise ValueError('variants must have the same name') if other.value == '*': return False if self.value == '*': self.value = other.value return True if self.value != other.value: raise UnsatisfiableVariantSpecError(other.value, self.value) return False
def __contains__(self, item): return item == self.value
[docs] def yaml_entry(self): return, self.value
[docs]class BoolValuedVariant(SingleValuedVariant): """A variant that can hold either True or False. BoolValuedVariant can also hold the value '*', for coerced comparisons between ``foo=*`` and ``+foo`` or ``~foo``.""" def _value_setter(self, value): # Check the string representation of the value and turn # it to a boolean if str(value).upper() == 'TRUE': self._original_value = value self._value = True elif str(value).upper() == 'FALSE': self._original_value = value self._value = False elif str(value) == '*': self._original_value = value self._value = '*' else: msg = 'cannot construct a BoolValuedVariant for "{0}" from ' msg += 'a value that does not represent a bool' raise ValueError(msg.format( def __contains__(self, item): return item is self.value def __str__(self): return '{0}{1}'.format('+' if self.value else '~',
[docs]class VariantMap(lang.HashableMap): """Map containing variant instances. New values can be added only if the key is not already present. """ def __init__(self, spec): super(VariantMap, self).__init__() self.spec = spec def __setitem__(self, name, vspec): # Raise a TypeError if vspec is not of the right type if not isinstance(vspec, AbstractVariant): msg = 'VariantMap accepts only values of variant types' msg += ' [got {0} instead]'.format(type(vspec).__name__) raise TypeError(msg) # Raise an error if the variant was already in this map if name in self.dict: msg = 'Cannot specify variant "{0}" twice'.format(name) raise DuplicateVariantError(msg) # Raise an error if name and don't match if name != msg = 'Inconsistent key "{0}", must be "{1}" to match VariantSpec' raise KeyError(msg.format(name, # Set the item super(VariantMap, self).__setitem__(name, vspec)
[docs] def substitute(self, vspec): """Substitutes the entry under ```` with ``vspec``. Args: vspec: variant spec to be substituted """ if not in self: msg = 'cannot substitute a key that does not exist [{0}]' raise KeyError(msg.format( # Set the item super(VariantMap, self).__setitem__(, vspec)
[docs] def satisfies(self, other, strict=False): """Returns True if this VariantMap is more constrained than other, False otherwise. Args: other (VariantMap): VariantMap instance to satisfy strict (bool): if True return False if a key is in other and not in self, otherwise discard that key and proceed with evaluation Returns: bool: True or False """ to_be_checked = [k for k in other] strict_or_concrete = strict if self.spec is not None: strict_or_concrete |= self.spec._concrete if not strict_or_concrete: to_be_checked = filter(lambda x: x in self, to_be_checked) return all(k in self and self[k].satisfies(other[k]) for k in to_be_checked)
[docs] def constrain(self, other): """Add all variants in other that aren't in self to self. Also constrain all multi-valued variants that are already present. Return True if self changed, False otherwise Args: other (VariantMap): instance against which we constrain self Returns: bool: True or False """ if other.spec is not None and other.spec._concrete: for k in self: if k not in other: raise UnsatisfiableVariantSpecError(self[k], '<absent>') changed = False for k in other: if k in self: # If they are not compatible raise an error if not self[k].compatible(other[k]): raise UnsatisfiableVariantSpecError(self[k], other[k]) # If they are compatible merge them changed |= self[k].constrain(other[k]) else: # If it is not present copy it straight away self[k] = other[k].copy() changed = True return changed
@property def concrete(self): """Returns True if the spec is concrete in terms of variants. Returns: bool: True or False """ return self.spec._concrete or all( v in self for v in self.spec.package_class.variants )
[docs] def copy(self): """Return an instance of VariantMap equivalent to self. Returns: VariantMap: a copy of self """ clone = VariantMap(self.spec) for name, variant in self.items(): clone[name] = variant.copy() return clone
def __str__(self): # print keys in order sorted_keys = sorted(self.keys()) # Separate boolean variants from key-value pairs as they print # differently. All booleans go first to avoid ' ~foo' strings that # break spec reuse in zsh. bool_keys = [] kv_keys = [] for key in sorted_keys: bool_keys.append(key) if isinstance(self[key].value, bool) \ else kv_keys.append(key) # add spaces before and after key/value variants. string = StringIO() for key in bool_keys: string.write(str(self[key])) for key in kv_keys: string.write(' ') string.write(str(self[key])) return string.getvalue()
[docs]def substitute_abstract_variants(spec): """Uses the information in `spec.package` to turn any variant that needs it into a SingleValuedVariant. This method is best effort. All variants that can be substituted will be substituted before any error is raised. Args: spec: spec on which to operate the substitution """ # This method needs to be best effort so that it works in matrix exlusion # in $spack/lib/spack/spack/ failed = [] for name, v in spec.variants.items(): if name in spack.directives.reserved_names: if name == 'dev_path': new_variant = SingleValuedVariant(name, v._original_value) spec.variants.substitute(new_variant) continue if name not in spec.package_class.variants: failed.append(name) continue pkg_variant, _ = spec.package_class.variants[name] new_variant = pkg_variant.make_variant(v._original_value) pkg_variant.validate_or_raise(new_variant, spec.package_class) spec.variants.substitute(new_variant) # Raise all errors at once if failed: raise UnknownVariantError(spec, failed)
# The class below inherit from Sequence to disguise as a tuple and comply # with the semantic expected by the 'values' argument of the variant directive
[docs]class DisjointSetsOfValues(Sequence): """Allows combinations from one of many mutually exclusive sets. The value ``('none',)`` is reserved to denote the empty set and therefore no other set can contain the item ``'none'``. Args: *sets (list): mutually exclusive sets of values """ _empty_set = set(('none',)) def __init__(self, *sets): self.sets = [set(_flatten(x)) for x in sets] # 'none' is a special value and can appear only in a set of # a single element if any('none' in s and s != set(('none',)) for s in self.sets): raise error.SpecError("The value 'none' represents the empty set," " and must appear alone in a set. Use the " "method 'allow_empty_set' to add it.") # Sets should not intersect with each other if any(s1 & s2 for s1, s2 in itertools.combinations(self.sets, 2)): raise error.SpecError('sets in input must be disjoint') #: Attribute used to track values which correspond to #: features which can be enabled or disabled as understood by the #: package's build system. self.feature_values = tuple(itertools.chain.from_iterable(self.sets)) self.default = None self.multi = True self.error_fmt = "this variant accepts combinations of values from " \ "exactly one of the following sets '{values}' " \ "@*r{{[{package}, variant '{variant}']}}"
[docs] def with_default(self, default): """Sets the default value and returns self.""" self.default = default return self
[docs] def with_error(self, error_fmt): """Sets the error message format and returns self.""" self.error_fmt = error_fmt return self
[docs] def with_non_feature_values(self, *values): """Marks a few values as not being tied to a feature.""" self.feature_values = tuple( x for x in self.feature_values if x not in values ) return self
[docs] def allow_empty_set(self): """Adds the empty set to the current list of disjoint sets.""" if self._empty_set in self.sets: return self # Create a new object to be returned object_with_empty_set = type(self)(('none',), *self.sets) object_with_empty_set.error_fmt = self.error_fmt object_with_empty_set.feature_values = self.feature_values + ('none', ) return object_with_empty_set
[docs] def prohibit_empty_set(self): """Removes the empty set from the current list of disjoint sets.""" if self._empty_set not in self.sets: return self # Create a new object to be returned sets = [s for s in self.sets if s != self._empty_set] object_without_empty_set = type(self)(*sets) object_without_empty_set.error_fmt = self.error_fmt object_without_empty_set.feature_values = tuple( x for x in self.feature_values if x != 'none' ) return object_without_empty_set
def __getitem__(self, idx): return tuple(itertools.chain.from_iterable(self.sets))[idx] def __len__(self): return len(itertools.chain.from_iterable(self.sets)) @property def validator(self): def _disjoint_set_validator(pkg_name, variant_name, values): # If for any of the sets, all the values are in it return True if any(all(x in s for x in values) for s in self.sets): return format_args = { 'variant': variant_name, 'package': pkg_name, 'values': values } msg = self.error_fmt + \ " @*r{{[{package}, variant '{variant}']}}" msg = llnl.util.tty.color.colorize(msg.format(**format_args)) raise error.SpecError(msg) return _disjoint_set_validator
def _a_single_value_or_a_combination(single_value, *values): error = "the value '" + single_value + \ "' is mutually exclusive with any of the other values" return DisjointSetsOfValues( (single_value,), values ).with_default(single_value).with_error(error).\ with_non_feature_values(single_value) # TODO: The factories below are used by package writers to set values of # TODO: multi-valued variants. It could be worthwhile to gather them in # TODO: a common namespace (like 'multi') in the future.
[docs]def any_combination_of(*values): """Multi-valued variant that allows any combination of the specified values, and also allows the user to specify 'none' (as a string) to choose none of them. It is up to the package implementation to handle the value 'none' specially, if at all. Args: *values: allowed variant values Returns: a properly initialized instance of DisjointSetsOfValues """ return _a_single_value_or_a_combination('none', *values)
[docs]def auto_or_any_combination_of(*values): """Multi-valued variant that allows any combination of a set of values (but not the empty set) or 'auto'. Args: *values: allowed variant values Returns: a properly initialized instance of DisjointSetsOfValues """ return _a_single_value_or_a_combination('auto', *values)
#: Multi-valued variant that allows any combination picking #: from one of multiple disjoint sets
[docs]def disjoint_sets(*sets): """Multi-valued variant that allows any combination picking from one of multiple disjoint sets of values, and also allows the user to specify 'none' (as a string) to choose none of them. It is up to the package implementation to handle the value 'none' specially, if at all. Args: *sets: Returns: a properly initialized instance of DisjointSetsOfValues """ return DisjointSetsOfValues(*sets).allow_empty_set().with_default('none')
[docs]@functools.total_ordering class Value(object): """Conditional value that might be used in variants.""" def __init__(self, value, when): self.value = value self.when = when def __repr__(self): return 'Value({0.value}, when={0.when})'.format(self) def __str__(self): return str(self.value) def __hash__(self): # Needed to allow testing the presence of a variant in a set by its value return hash(self.value) def __eq__(self, other): if isinstance(other, six.string_types): return self.value == other return self.value == other.value def __lt__(self, other): if isinstance(other, six.string_types): return self.value < other return self.value < other.value
class _ConditionalVariantValues(lang.TypedMutableSequence): """A list, just with a different type"""
[docs]def conditional(*values, **kwargs): """Conditional values that can be used in variant declarations.""" if len(kwargs) != 1 and 'when' not in kwargs: raise ValueError('conditional statement expects a "when=" parameter only') when = kwargs['when'] return _ConditionalVariantValues([Value(x, when=when) for x in values])
[docs]class DuplicateVariantError(error.SpecError): """Raised when the same variant occurs in a spec twice."""
[docs]class UnknownVariantError(error.SpecError): """Raised when an unknown variant occurs in a spec.""" def __init__(self, spec, variants): self.unknown_variants = variants variant_str = 'variant' if len(variants) == 1 else 'variants' msg = ('trying to set {0} "{1}" in package "{2}", but the package' ' has no such {0} [happened during concretization of {3}]') msg = msg.format(variant_str, comma_or(variants),, spec.root) super(UnknownVariantError, self).__init__(msg)
[docs]class InconsistentValidationError(error.SpecError): """Raised if the wrong validator is used to validate a variant.""" def __init__(self, vspec, variant): msg = ('trying to validate variant "{}" ' 'with the validator of "{}"') super(InconsistentValidationError, self).__init__( msg.format(vspec, variant) )
[docs]class MultipleValuesInExclusiveVariantError(error.SpecError, ValueError): """Raised when multiple values are present in a variant that wants only one. """ def __init__(self, variant, pkg): msg = 'multiple values are not allowed for variant "{}"{1}' pkg_info = '' if pkg is not None: pkg_info = ' in package "{0}"'.format( super(MultipleValuesInExclusiveVariantError, self).__init__( msg.format(variant, pkg_info) )
[docs]class InvalidVariantValueCombinationError(error.SpecError): """Raised when a variant has values '*' or 'none' with other values."""
[docs]class InvalidVariantValueError(error.SpecError): """Raised when a valid variant has at least an invalid value.""" def __init__(self, variant, invalid_values, pkg): msg = 'invalid values for variant "{}"{2}: {1}\n' pkg_info = '' if pkg is not None: pkg_info = ' in package "{0}"'.format( super(InvalidVariantValueError, self).__init__( msg.format(variant, invalid_values, pkg_info) )
[docs]class InvalidVariantForSpecError(error.SpecError): """Raised when an invalid conditional variant is specified.""" def __init__(self, variant, when, spec): msg = "Invalid variant {0} for spec {1}.\n" msg += "{0} is only available for {} when satisfying one of {2}." super(InvalidVariantForSpecError, self).__init__( msg.format(variant, spec, when) )
[docs]class UnsatisfiableVariantSpecError(error.UnsatisfiableSpecError): """Raised when a spec variant conflicts with package constraints.""" def __init__(self, provided, required): super(UnsatisfiableVariantSpecError, self).__init__( provided, required, "variant")