# Copyright Spack Project Developers. See COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)
"""Parser for spec literals
Here is the EBNF grammar for a spec::
spec = [name] [node_options] { ^[edge_properties] node } |
[name] [node_options] hash |
filename
node = name [node_options] |
[name] [node_options] hash |
filename
node_options = [@(version_list|version_pair)] [%compiler] { variant }
edge_properties = [ { bool_variant | key_value } ]
hash = / id
filename = (.|/|[a-zA-Z0-9-_]*/)([a-zA-Z0-9-_./]*)(.json|.yaml)
name = id | namespace id
namespace = { id . }
variant = bool_variant | key_value | propagated_bv | propagated_kv
bool_variant = +id | ~id | -id
propagated_bv = ++id | ~~id | --id
key_value = id=id | id=quoted_id
propagated_kv = id==id | id==quoted_id
compiler = id [@version_list]
version_pair = git_version=vid
version_list = (version|version_range) [ { , (version|version_range)} ]
version_range = vid:vid | vid: | :vid | :
version = vid
git_version = git.(vid) | git_hash
git_hash = [A-Fa-f0-9]{40}
quoted_id = " id_with_ws " | ' id_with_ws '
id_with_ws = [a-zA-Z0-9_][a-zA-Z_0-9-.\\s]*
vid = [a-zA-Z0-9_][a-zA-Z_0-9-.]*
id = [a-zA-Z0-9_][a-zA-Z_0-9-]*
Identifiers using the ``<name>=<value>`` command, such as architectures and
compiler flags, require a space before the name.
There is one context-sensitive part: ids in versions may contain ``.``, while
other ids may not.
There is one ambiguity: since ``-`` is allowed in an id, you need to put
whitespace space before ``-variant`` for it to be tokenized properly. You can
either use whitespace, or you can just use ``~variant`` since it means the same
thing. Spack uses ``~variant`` in directory names and in the canonical form of
specs to avoid ambiguity. Both are provided because ``~`` can cause shell
expansion when it is the first character in an id typed on the command line.
"""
import json
import pathlib
import re
import sys
from typing import TYPE_CHECKING, Dict, Iterator, List, Optional, Tuple, Union
import spack.deptypes
import spack.error
import spack.version
from spack.aliases import LEGACY_COMPILER_TO_BUILTIN
from spack.enums import PropagationPolicy
from spack.llnl.util.tty import color
from spack.tokenize import Token, TokenBase, Tokenizer
if TYPE_CHECKING:
import spack.spec
#: Valid name for specs and variants. Here we are not using
#: the previous ``w[\w.-]*`` since that would match most
#: characters that can be part of a word in any language
IDENTIFIER = r"(?:[a-zA-Z_0-9][a-zA-Z_0-9\-]*)"
DOTTED_IDENTIFIER = rf"(?:{IDENTIFIER}(?:\.{IDENTIFIER})+)"
GIT_HASH = r"(?:[A-Fa-f0-9]{40})"
#: Git refs include branch names, and can contain ``.`` and ``/``
GIT_REF = r"(?:[a-zA-Z_0-9][a-zA-Z_0-9./\-]*)"
GIT_VERSION_PATTERN = rf"(?:(?:git\.(?:{GIT_REF}))|(?:{GIT_HASH}))"
#: Substitute a package for a virtual, e.g., c,cxx=gcc.
#: NOTE: Overlaps w/KVP; this should be first if matched in sequence.
VIRTUAL_ASSIGNMENT = (
r"(?:"
rf"(?P<virtuals>{IDENTIFIER}(?:,{IDENTIFIER})*)" # comma-separated virtuals
rf"=(?P<substitute>{DOTTED_IDENTIFIER}|{IDENTIFIER})" # package to substitute
r")"
)
STAR = r"\*"
NAME = r"[a-zA-Z_0-9][a-zA-Z_0-9\-.]*"
HASH = r"[a-zA-Z_0-9]+"
#: These are legal values that *can* be parsed bare, without quotes on the command line.
VALUE = r"(?:[a-zA-Z_0-9\-+\*.,:=%^\~\/\\]+)"
#: Quoted values can be *anything* in between quotes, including escaped quotes.
QUOTED_VALUE = r"(?:'(?:[^']|(?<=\\)')*'|\"(?:[^\"]|(?<=\\)\")*\")"
VERSION = r"=?(?:[a-zA-Z0-9_][a-zA-Z_0-9\-\.]*\b)"
VERSION_RANGE = rf"(?:(?:{VERSION})?:(?:{VERSION}(?!\s*=))?)"
VERSION_LIST = rf"(?:{VERSION_RANGE}|{VERSION})(?:\s*,\s*(?:{VERSION_RANGE}|{VERSION}))*"
SPLIT_KVP = re.compile(rf"^({NAME})(:?==?)(.*)$")
#: A filename starts either with a ``.`` or a ``/`` or a ``{name}/``, or on Windows, a drive letter
#: followed by a colon and ``\`` or ``.`` or ``{name}\``
WINDOWS_FILENAME = r"(?:\.|[a-zA-Z0-9-_]*\\|[a-zA-Z]:\\)(?:[a-zA-Z0-9-_\.\\]*)(?:\.json|\.yaml)"
UNIX_FILENAME = r"(?:\.|\/|[a-zA-Z0-9-_]*\/)(?:[a-zA-Z0-9-_\.\/]*)(?:\.json|\.yaml)"
FILENAME = WINDOWS_FILENAME if sys.platform == "win32" else UNIX_FILENAME
#: Regex to strip quotes. Group 2 will be the unquoted string.
STRIP_QUOTES = re.compile(r"^(['\"])(.*)\1$")
#: Values that match this (e.g., variants, flags) can be left unquoted in Spack output
NO_QUOTES_NEEDED = re.compile(r"^[a-zA-Z0-9,/_.\-\[\]]+$")
[docs]
class SpecTokens(TokenBase):
"""Enumeration of the different token kinds of tokens in the spec grammar.
Order of declaration is extremely important, since text containing specs is parsed with a
single regex obtained by ``"|".join(...)`` of all the regex in the order of declaration.
"""
# Dependency, with optional virtual assignment specifier
START_EDGE_PROPERTIES = r"(?:(?:\^|\%\%|\%)\[)"
END_EDGE_PROPERTIES = rf"(?:\](?:\s*{VIRTUAL_ASSIGNMENT})?)"
DEPENDENCY = rf"(?:(?:\^|\%\%|\%)(?:\s*{VIRTUAL_ASSIGNMENT})?)"
# Version
VERSION_HASH_PAIR = rf"(?:@(?:{GIT_VERSION_PATTERN})=(?:{VERSION}))"
GIT_VERSION = rf"@(?:{GIT_VERSION_PATTERN})"
VERSION = rf"(?:@\s*(?:{VERSION_LIST}))"
# Variants
PROPAGATED_BOOL_VARIANT = rf"(?:(?:\+\+|~~|--)\s*{NAME})"
BOOL_VARIANT = rf"(?:[~+-]\s*{NAME})"
PROPAGATED_KEY_VALUE_PAIR = rf"(?:{NAME}:?==(?:{VALUE}|{QUOTED_VALUE}))"
KEY_VALUE_PAIR = rf"(?:{NAME}:?=(?:{VALUE}|{QUOTED_VALUE}))"
# FILENAME
FILENAME = rf"(?:{FILENAME})"
# Package name
FULLY_QUALIFIED_PACKAGE_NAME = rf"(?:{DOTTED_IDENTIFIER})"
UNQUALIFIED_PACKAGE_NAME = rf"(?:{IDENTIFIER}|{STAR})"
# DAG hash
DAG_HASH = rf"(?:/(?:{HASH}))"
# White spaces
WS = r"(?:\s+)"
# Unexpected character(s)
UNEXPECTED = r"(?:.[\s]*)"
#: Tokenizer that includes all the regexes in the SpecTokens enum
SPEC_TOKENIZER = Tokenizer(SpecTokens)
[docs]
def tokenize(text: str) -> Iterator[Token]:
"""Return a token generator from the text passed as input.
Raises:
SpecTokenizationError: when unexpected characters are found in the text
"""
for token in SPEC_TOKENIZER.tokenize(text):
if token.kind == SpecTokens.UNEXPECTED:
raise SpecTokenizationError(list(SPEC_TOKENIZER.tokenize(text)), text)
yield token
[docs]
def parseable_tokens(text: str) -> Iterator[Token]:
"""Return non-whitespace tokens from the text passed as input
Raises:
SpecTokenizationError: when unexpected characters are found in the text
"""
return filter(lambda x: x.kind != SpecTokens.WS, tokenize(text))
[docs]
class TokenContext:
"""Token context passed around by parsers"""
__slots__ = "token_stream", "current_token", "next_token", "pushed_tokens"
def __init__(self, token_stream: Iterator[Token]):
self.token_stream = token_stream
self.current_token = None
self.next_token = None # the next token to be read
# if not empty, back of list is front of stream, and we pop from here instead.
self.pushed_tokens: List[Token] = []
self.advance()
[docs]
def advance(self):
"""Advance one token"""
self.current_token = self.next_token
if self.pushed_tokens:
self.next_token = self.pushed_tokens.pop()
else:
self.next_token = next(self.token_stream, None)
[docs]
def accept(self, kind: SpecTokens):
"""If the next token is of the specified kind, advance the stream and return True.
Otherwise return False.
"""
if self.next_token and self.next_token.kind == kind:
self.advance()
return True
return False
[docs]
def push_front(self, token=Token):
"""Push a token onto the front of the stream. Enables a bit of lookahead."""
self.pushed_tokens.append(self.next_token) # back of list is front of stream
self.next_token = token
[docs]
def expect(self, *kinds: SpecTokens):
return self.next_token and self.next_token.kind in kinds
[docs]
class SpecTokenizationError(spack.error.SpecSyntaxError):
"""Syntax error in a spec string"""
def __init__(self, tokens: List[Token], text: str):
message = f"unexpected characters in the spec string\n{text}\n"
underline = ""
for token in tokens:
is_error = token.kind == SpecTokens.UNEXPECTED
underline += ("^" if is_error else " ") * (token.end - token.start)
message += color.colorize(f"@*r{{{underline}}}")
super().__init__(message)
[docs]
def parse_virtual_assignment(context: TokenContext) -> Tuple[str]:
"""Look at subvalues and, if present, extract virtual and a push a substitute token.
This handles things like:
* ``^c=gcc``
* ``^c,cxx=gcc``
* ``%[when=+bar] c=gcc``
* ``%[when=+bar] c,cxx=gcc``
Virtual assignment can happen anywhere a dependency node can appear. It is
shorthand for ``%[virtuals=c,cxx] gcc``.
The ``virtuals=substitute`` key value pair appears in the subvalues of
:attr:`~spack.spec_parser.SpecTokens.DEPENDENCY` and
:attr:`~spack.spec_parser.SpecTokens.END_EDGE_PROPERTIES` tokens. We extract the virtuals and
create a token from the substitute, which is then pushed back on the parser stream so that the
head of the stream can be parsed like a regular node.
Returns:
the virtuals assigned, or None if there aren't any
"""
assert context.current_token is not None
subvalues = context.current_token.subvalues
if not subvalues:
return ()
# build a token for the substitute that we can put back on the stream
pkg = subvalues["substitute"]
token_type = SpecTokens.UNQUALIFIED_PACKAGE_NAME
if "." in pkg:
token_type = SpecTokens.FULLY_QUALIFIED_PACKAGE_NAME
start = context.current_token.value.index(pkg)
token = Token(token_type, pkg, start, start + len(pkg))
context.push_front(token)
return tuple(subvalues["virtuals"].split(","))
[docs]
class SpecParser:
"""Parse text into specs"""
__slots__ = "literal_str", "ctx"
def __init__(self, literal_str: str):
self.literal_str = literal_str
self.ctx = TokenContext(parseable_tokens(literal_str))
[docs]
def tokens(self) -> List[Token]:
"""Return the entire list of token from the initial text. White spaces are
filtered out.
"""
return list(filter(lambda x: x.kind != SpecTokens.WS, tokenize(self.literal_str)))
[docs]
def next_spec(
self, initial_spec: Optional["spack.spec.Spec"] = None
) -> Optional["spack.spec.Spec"]:
"""Return the next spec parsed from text.
Args:
initial_spec: object where to parse the spec. If None a new one
will be created.
Return:
The spec that was parsed
"""
if not self.ctx.next_token:
return initial_spec
def add_dependency(dep, **edge_properties):
"""wrapper around root_spec._add_dependency"""
try:
target_spec._add_dependency(dep, **edge_properties)
except spack.error.SpecError as e:
raise SpecParsingError(str(e), self.ctx.current_token, self.literal_str) from e
if not initial_spec:
from spack.spec import Spec
initial_spec = Spec()
root_spec = SpecNodeParser(self.ctx, self.literal_str).parse(initial_spec)
current_spec = root_spec
while True:
if self.ctx.accept(SpecTokens.START_EDGE_PROPERTIES):
has_edge_attrs = True
elif self.ctx.accept(SpecTokens.DEPENDENCY):
has_edge_attrs = False
else:
break
is_direct = self.ctx.current_token.value[0] == "%"
propagation = PropagationPolicy.NONE
if is_direct and self.ctx.current_token.value.startswith("%%"):
propagation = PropagationPolicy.PREFERENCE
if has_edge_attrs:
edge_properties = EdgeAttributeParser(self.ctx, self.literal_str).parse()
edge_properties.setdefault("virtuals", ())
edge_properties.setdefault("depflag", 0)
else:
virtuals = parse_virtual_assignment(self.ctx)
edge_properties = {"virtuals": virtuals, "depflag": 0}
edge_properties["direct"] = is_direct
edge_properties["propagation"] = propagation
dependency = self._parse_node(root_spec)
if is_direct:
target_spec = current_spec
if dependency.name in LEGACY_COMPILER_TO_BUILTIN:
dependency.name = LEGACY_COMPILER_TO_BUILTIN[dependency.name]
else:
current_spec = dependency
target_spec = root_spec
add_dependency(dependency, **edge_properties)
return root_spec
def _parse_node(self, root_spec: "spack.spec.Spec", root: bool = True):
dependency = SpecNodeParser(self.ctx, self.literal_str).parse(root=root)
if dependency is None:
msg = (
"the dependency sigil and any optional edge attributes must be followed by a "
"package name or a node attribute (version, variant, etc.)"
)
raise SpecParsingError(msg, self.ctx.current_token, self.literal_str)
if root_spec.concrete:
raise spack.error.SpecError(str(root_spec), "^" + str(dependency))
return dependency
[docs]
def all_specs(self) -> List["spack.spec.Spec"]:
"""Return all the specs that remain to be parsed"""
return list(iter(self.next_spec, None))
[docs]
class SpecNodeParser:
"""Parse a single spec node from a stream of tokens"""
__slots__ = "ctx", "has_version", "literal_str"
def __init__(self, ctx, literal_str):
self.ctx = ctx
self.literal_str = literal_str
self.has_version = False
[docs]
def parse(
self, initial_spec: Optional["spack.spec.Spec"] = None, root: bool = True
) -> "spack.spec.Spec":
"""Parse a single spec node from a stream of tokens
Args:
initial_spec: object to be constructed
root: True if we're parsing a root, False if dependency after ^ or %
Return:
The object passed as argument
"""
if initial_spec is None:
from spack.spec import Spec
initial_spec = Spec()
if not self.ctx.next_token or self.ctx.expect(SpecTokens.DEPENDENCY):
return initial_spec
# If we start with a package name we have a named spec, we cannot
# accept another package name afterwards in a node
if self.ctx.accept(SpecTokens.UNQUALIFIED_PACKAGE_NAME):
# if name is '*', this is an anonymous spec
if self.ctx.current_token.value != "*":
initial_spec.name = self.ctx.current_token.value
elif self.ctx.accept(SpecTokens.FULLY_QUALIFIED_PACKAGE_NAME):
parts = self.ctx.current_token.value.split(".")
name = parts[-1]
namespace = ".".join(parts[:-1])
initial_spec.name = name
initial_spec.namespace = namespace
elif self.ctx.accept(SpecTokens.FILENAME):
return FileParser(self.ctx).parse(initial_spec)
def raise_parsing_error(string: str, cause: Optional[Exception] = None):
"""Raise a spec parsing error with token context."""
raise SpecParsingError(string, self.ctx.current_token, self.literal_str) from cause
def add_flag(name: str, value: Union[str, bool], propagate: bool, concrete: bool):
"""Wrapper around ``Spec._add_flag()`` that adds parser context to errors raised."""
try:
initial_spec._add_flag(name, value, propagate, concrete)
except Exception as e:
raise_parsing_error(str(e), e)
while True:
if (
self.ctx.accept(SpecTokens.VERSION_HASH_PAIR)
or self.ctx.accept(SpecTokens.GIT_VERSION)
or self.ctx.accept(SpecTokens.VERSION)
):
if self.has_version:
raise_parsing_error("Spec cannot have multiple versions")
initial_spec.versions = spack.version.VersionList(
[spack.version.from_string(self.ctx.current_token.value[1:])]
)
initial_spec.attach_git_version_lookup()
self.has_version = True
elif self.ctx.accept(SpecTokens.BOOL_VARIANT):
name = self.ctx.current_token.value[1:].strip()
variant_value = self.ctx.current_token.value[0] == "+"
add_flag(name, variant_value, propagate=False, concrete=True)
elif self.ctx.accept(SpecTokens.PROPAGATED_BOOL_VARIANT):
name = self.ctx.current_token.value[2:].strip()
variant_value = self.ctx.current_token.value[0:2] == "++"
add_flag(name, variant_value, propagate=True, concrete=True)
elif self.ctx.accept(SpecTokens.KEY_VALUE_PAIR):
name, value = self.ctx.current_token.value.split("=", maxsplit=1)
concrete = name.endswith(":")
if concrete:
name = name[:-1]
add_flag(
name, strip_quotes_and_unescape(value), propagate=False, concrete=concrete
)
elif self.ctx.accept(SpecTokens.PROPAGATED_KEY_VALUE_PAIR):
name, value = self.ctx.current_token.value.split("==", maxsplit=1)
concrete = name.endswith(":")
if concrete:
name = name[:-1]
add_flag(name, strip_quotes_and_unescape(value), propagate=True, concrete=concrete)
elif self.ctx.expect(SpecTokens.DAG_HASH):
if initial_spec.abstract_hash:
break
self.ctx.accept(SpecTokens.DAG_HASH)
initial_spec.abstract_hash = self.ctx.current_token.value[1:]
else:
break
return initial_spec
[docs]
class FileParser:
"""Parse a single spec from a JSON or YAML file"""
__slots__ = ("ctx",)
def __init__(self, ctx):
self.ctx = ctx
[docs]
def parse(self, initial_spec: "spack.spec.Spec") -> "spack.spec.Spec":
"""Parse a spec tree from a specfile.
Args:
initial_spec: object where to parse the spec
Return:
The initial_spec passed as argument, once constructed
"""
file = pathlib.Path(self.ctx.current_token.value)
if not file.exists():
raise spack.error.NoSuchSpecFileError(f"No such spec file: '{file}'")
from spack.spec import Spec
with file.open("r", encoding="utf-8") as stream:
if str(file).endswith(".json"):
spec_from_file = Spec.from_json(stream)
else:
spec_from_file = Spec.from_yaml(stream)
initial_spec._dup(spec_from_file)
return initial_spec
[docs]
class EdgeAttributeParser:
__slots__ = "ctx", "literal_str"
def __init__(self, ctx, literal_str):
self.ctx = ctx
self.literal_str = literal_str
[docs]
def parse(self):
attributes = {}
while True:
if self.ctx.accept(SpecTokens.KEY_VALUE_PAIR):
name, value = self.ctx.current_token.value.split("=", maxsplit=1)
if name.endswith(":"):
name = name[:-1]
value = value.strip("'\" ").split(",")
attributes[name] = value
if name not in ("deptypes", "virtuals", "when"):
msg = (
"the only edge attributes that are currently accepted "
'are "deptypes", "virtuals", and "when"'
)
raise SpecParsingError(msg, self.ctx.current_token, self.literal_str)
# TODO: Add code to accept bool variants here as soon as use variants are implemented
elif self.ctx.accept(SpecTokens.END_EDGE_PROPERTIES):
virtuals = attributes.get("virtuals", ())
virtuals += parse_virtual_assignment(self.ctx)
attributes["virtuals"] = virtuals
break
else:
msg = "unexpected token in edge attributes"
raise SpecParsingError(msg, self.ctx.next_token, self.literal_str)
# Turn deptypes=... to depflag representation
if "deptypes" in attributes:
deptype_string = attributes.pop("deptypes")
attributes["depflag"] = spack.deptypes.canonicalize(deptype_string)
# Turn "when" into a spec
if "when" in attributes:
attributes["when"] = parse_one_or_raise(attributes["when"][0])
return attributes
[docs]
def parse(text: str, *, toolchains: Optional[Dict] = None) -> List["spack.spec.Spec"]:
"""Parse text into a list of specs
Args:
text: text to be parsed
toolchains: optional toolchain definitions to expand after parsing
Return:
List of specs
"""
specs = SpecParser(text).all_specs()
if toolchains:
cache: Dict[str, "spack.spec.Spec"] = {}
for spec in specs:
expand_toolchains(spec, toolchains, _cache=cache)
return specs
[docs]
def parse_one_or_raise(
text: str,
initial_spec: Optional["spack.spec.Spec"] = None,
*,
toolchains: Optional[Dict] = None,
) -> "spack.spec.Spec":
"""Parse exactly one spec from text and return it, or raise
Args:
text: text to be parsed
initial_spec: buffer where to parse the spec. If None a new one will be created.
toolchains: optional toolchain definitions to expand after parsing
"""
parser = SpecParser(text)
result = parser.next_spec(initial_spec)
next_token = parser.ctx.next_token
if next_token:
message = f"expected a single spec, but got more:\n{text}"
underline = f"\n{' ' * next_token.start}{'^' * len(next_token.value)}"
message += color.colorize(f"@*r{{{underline}}}")
raise ValueError(message)
if result is None:
raise ValueError("expected a single spec, but got none")
if toolchains:
expand_toolchains(result, toolchains)
return result
def _parse_toolchain_config(toolchain_config: Union[str, List[Dict]]) -> "spack.spec.Spec":
"""Parse a toolchain config entry (string or list) into a Spec."""
if isinstance(toolchain_config, str):
toolchain = parse_one_or_raise(toolchain_config)
_ensure_all_direct_edges(toolchain)
else:
from spack.spec import EMPTY_SPEC, Spec
toolchain = Spec()
for entry in toolchain_config:
toolchain_part = parse_one_or_raise(entry["spec"])
when = entry.get("when", "")
_ensure_all_direct_edges(toolchain_part)
if when:
when_spec = Spec(when)
for edge in toolchain_part.traverse_edges():
if edge.when is EMPTY_SPEC:
edge.when = when_spec.copy()
else:
edge.when.constrain(when_spec)
toolchain.constrain(toolchain_part)
return toolchain
def _ensure_all_direct_edges(constraint: "spack.spec.Spec") -> None:
"""Validate that a toolchain spec only has direct (%) edges."""
for edge in constraint.traverse_edges(root=False):
if not edge.direct:
raise spack.error.SpecError(
f"cannot use '^' in toolchain definitions, and the current "
f"toolchain contains '{edge.format()}'"
)
[docs]
class SpecParsingError(spack.error.SpecSyntaxError):
"""Error when parsing tokens"""
def __init__(self, message, token, text):
message += f"\n{text}"
if token:
underline = f"\n{' ' * token.start}{'^' * (token.end - token.start)}"
message += color.colorize(f"@*r{{{underline}}}")
super().__init__(message)
[docs]
def strip_quotes_and_unescape(string: str) -> str:
"""Remove surrounding single or double quotes from string, if present."""
match = STRIP_QUOTES.match(string)
if not match:
return string
# replace any escaped quotes with bare quotes
quote, result = match.groups()
return result.replace(rf"\{quote}", quote)
[docs]
def quote_if_needed(value: str) -> str:
"""Add quotes around the value if it requires quotes.
This will add quotes around the value unless it matches :data:`NO_QUOTES_NEEDED`.
This adds:
* single quotes by default
* double quotes around any value that contains single quotes
If double quotes are used, we json-escape the string. That is, we escape ``\\``,
``"``, and control codes.
"""
if NO_QUOTES_NEEDED.match(value):
return value
return json.dumps(value) if "'" in value else f"'{value}'"