# Copyright 2013-2023 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)
"""Parser for spec literals
Here is the EBNF grammar for a spec::
spec = [name] [node_options] { ^ node } |
[name] [node_options] hash |
filename
node = name [node_options] |
[name] [node_options] hash |
filename
node_options = [@(version_list|version_pair)] [%compiler] { variant }
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 enum
import pathlib
import re
import sys
from typing import Iterator, List, Match, Optional
from llnl.util.tty import color
import spack.error
import spack.spec
import spack.variant
import spack.version
IS_WINDOWS = sys.platform == "win32"
#: 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_VERSION = rf"((git\.({DOTTED_IDENTIFIER}|{IDENTIFIER}))|({GIT_HASH}))"
NAME = r"[a-zA-Z_0-9][a-zA-Z_0-9\-.]*"
HASH = r"[a-zA-Z_0-9]+"
#: 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)"
if not IS_WINDOWS:
FILENAME = UNIX_FILENAME
else:
FILENAME = WINDOWS_FILENAME
VALUE = r"([a-zA-Z_0-9\-+\*.,:=\~\/\\]+)"
QUOTED_VALUE = r"[\"']+([a-zA-Z_0-9\-+\*.,:=\~\/\\\s]+)[\"']+"
VERSION = r"=?([a-zA-Z0-9_][a-zA-Z_0-9\-\.]*\b)"
VERSION_RANGE = rf"({VERSION}\s*:\s*{VERSION}(?!\s*=)|:\s*{VERSION}(?!\s*=)|{VERSION}\s*:|:)"
VERSION_LIST = rf"({VERSION_RANGE}|{VERSION})(\s*[,]\s*({VERSION_RANGE}|{VERSION}))*"
[docs]class TokenBase(enum.Enum):
"""Base class for an enum type with a regex value"""
def __new__(cls, *args, **kwargs):
# See
value = len(cls.__members__) + 1
obj = object.__new__(cls)
obj._value_ = value
return obj
def __init__(self, regex):
self.regex = regex
def __str__(self):
return f"{self._name_}"
[docs]class TokenType(TokenBase):
"""Enumeration of the different token kinds 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
DEPENDENCY = r"(\^)"
# Version
VERSION_HASH_PAIR = rf"(@({GIT_VERSION})=({VERSION}))"
VERSION = rf"(@\s*({VERSION_LIST}))"
# Variants
PROPAGATED_BOOL_VARIANT = rf"((\+\+|~~|--)\s*{NAME})"
BOOL_VARIANT = rf"([~+-]\s*{NAME})"
PROPAGATED_KEY_VALUE_PAIR = rf"({NAME}\s*==\s*({VALUE}|{QUOTED_VALUE}))"
KEY_VALUE_PAIR = rf"({NAME}\s*=\s*({VALUE}|{QUOTED_VALUE}))"
# Compilers
COMPILER_AND_VERSION = rf"(%\s*({NAME})([\s]*)@\s*({VERSION_LIST}))"
COMPILER = rf"(%\s*({NAME}))"
# FILENAME
FILENAME = rf"({FILENAME})"
# Package name
FULLY_QUALIFIED_PACKAGE_NAME = rf"({DOTTED_IDENTIFIER})"
UNQUALIFIED_PACKAGE_NAME = rf"({IDENTIFIER})"
# DAG hash
DAG_HASH = rf"(/({HASH}))"
# White spaces
WS = r"(\s+)"
[docs]class ErrorTokenType(TokenBase):
"""Enum with regexes for error analysis"""
# Unexpected character
UNEXPECTED = r"(.[\s]*)"
[docs]class Token:
"""Represents tokens; generated from input by lexer and fed to parse()."""
__slots__ = "kind", "value", "start", "end"
def __init__(
self, kind: TokenType, value: str, start: Optional[int] = None, end: Optional[int] = None
):
self.kind = kind
self.value = value
self.start = start
self.end = end
def __repr__(self):
return str(self)
def __str__(self):
return f"({self.kind}, {self.value})"
def __eq__(self, other):
return (self.kind == other.kind) and (self.value == other.value)
#: List of all the regexes used to match spec parts, in order of precedence
TOKEN_REGEXES = [rf"(?P<{token}>{token.regex})" for token in TokenType]
#: List of all valid regexes followed by error analysis regexes
ERROR_HANDLING_REGEXES = TOKEN_REGEXES + [
rf"(?P<{token}>{token.regex})" for token in ErrorTokenType
]
#: Regex to scan a valid text
ALL_TOKENS = re.compile("|".join(TOKEN_REGEXES))
#: Regex to analyze an invalid text
ANALYSIS_REGEX = re.compile("|".join(ERROR_HANDLING_REGEXES))
[docs]def tokenize(text: str) -> Iterator[Token]:
"""Return a token generator from the text passed as input.
Raises:
SpecTokenizationError: if we can't tokenize anymore, but didn't reach the
end of the input text.
"""
scanner = ALL_TOKENS.scanner(text) # type: ignore[attr-defined]
match: Optional[Match] = None
for match in iter(scanner.match, None):
yield Token(
TokenType.__members__[match.lastgroup], # type: ignore[attr-defined]
match.group(), # type: ignore[attr-defined]
match.start(), # type: ignore[attr-defined]
match.end(), # type: ignore[attr-defined]
)
if match is None and not text:
# We just got an empty string
return
if match is None or match.end() != len(text):
scanner = ANALYSIS_REGEX.scanner(text) # type: ignore[attr-defined]
matches = [m for m in iter(scanner.match, None)] # type: ignore[var-annotated]
raise SpecTokenizationError(matches, text)
[docs]class TokenContext:
"""Token context passed around by parsers"""
__slots__ = "token_stream", "current_token", "next_token"
def __init__(self, token_stream: Iterator[Token]):
self.token_stream = token_stream
self.current_token = None
self.next_token = None
self.advance()
[docs] def advance(self):
"""Advance one token"""
self.current_token, self.next_token = self.next_token, next(self.token_stream, None)
[docs] def accept(self, kind: TokenType):
"""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 expect(self, *kinds: TokenType):
return self.next_token and self.next_token.kind in kinds
[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(filter(lambda x: x.kind != TokenType.WS, tokenize(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 != TokenType.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
initial_spec = initial_spec or spack.spec.Spec()
root_spec = SpecNodeParser(self.ctx).parse(initial_spec)
while True:
if self.ctx.accept(TokenType.DEPENDENCY):
dependency = SpecNodeParser(self.ctx).parse()
if dependency is None:
msg = (
"this dependency sigil needs to 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.spec.RedundantSpecError(root_spec, "^" + str(dependency))
root_spec._add_dependency(dependency, deptypes=())
else:
break
return root_spec
[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_compiler", "has_version", "has_hash"
def __init__(self, ctx):
self.ctx = ctx
self.has_compiler = False
self.has_version = False
self.has_hash = False
[docs] def parse(self, initial_spec: Optional[spack.spec.Spec] = None) -> Optional[spack.spec.Spec]:
"""Parse a single spec node from a stream of tokens
Args:
initial_spec: object to be constructed
Return
The object passed as argument
"""
if not self.ctx.next_token or self.ctx.expect(TokenType.DEPENDENCY):
return initial_spec
initial_spec = initial_spec or spack.spec.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(TokenType.UNQUALIFIED_PACKAGE_NAME):
initial_spec.name = self.ctx.current_token.value
elif self.ctx.accept(TokenType.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(TokenType.FILENAME):
return FileParser(self.ctx).parse(initial_spec)
while True:
if self.ctx.accept(TokenType.COMPILER):
self.hash_not_parsed_or_raise(initial_spec, self.ctx.current_token.value)
if self.has_compiler:
raise spack.spec.DuplicateCompilerSpecError(
f"{initial_spec} cannot have multiple compilers"
)
compiler_name = self.ctx.current_token.value[1:]
initial_spec.compiler = spack.spec.CompilerSpec(compiler_name.strip(), ":")
self.has_compiler = True
elif self.ctx.accept(TokenType.COMPILER_AND_VERSION):
self.hash_not_parsed_or_raise(initial_spec, self.ctx.current_token.value)
if self.has_compiler:
raise spack.spec.DuplicateCompilerSpecError(
f"{initial_spec} cannot have multiple compilers"
)
compiler_name, compiler_version = self.ctx.current_token.value[1:].split("@")
initial_spec.compiler = spack.spec.CompilerSpec(
compiler_name.strip(), compiler_version
)
self.has_compiler = True
elif self.ctx.accept(TokenType.VERSION) or self.ctx.accept(
TokenType.VERSION_HASH_PAIR
):
self.hash_not_parsed_or_raise(initial_spec, self.ctx.current_token.value)
if self.has_version:
raise spack.spec.MultipleVersionError(
f"{initial_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(TokenType.BOOL_VARIANT):
self.hash_not_parsed_or_raise(initial_spec, self.ctx.current_token.value)
variant_value = self.ctx.current_token.value[0] == "+"
initial_spec._add_flag(
self.ctx.current_token.value[1:].strip(), variant_value, propagate=False
)
elif self.ctx.accept(TokenType.PROPAGATED_BOOL_VARIANT):
self.hash_not_parsed_or_raise(initial_spec, self.ctx.current_token.value)
variant_value = self.ctx.current_token.value[0:2] == "++"
initial_spec._add_flag(
self.ctx.current_token.value[2:].strip(), variant_value, propagate=True
)
elif self.ctx.accept(TokenType.KEY_VALUE_PAIR):
self.hash_not_parsed_or_raise(initial_spec, self.ctx.current_token.value)
name, value = self.ctx.current_token.value.split("=", maxsplit=1)
name = name.strip("'\" ")
value = value.strip("'\" ")
initial_spec._add_flag(name, value, propagate=False)
elif self.ctx.accept(TokenType.PROPAGATED_KEY_VALUE_PAIR):
self.hash_not_parsed_or_raise(initial_spec, self.ctx.current_token.value)
name, value = self.ctx.current_token.value.split("==", maxsplit=1)
name = name.strip("'\" ")
value = value.strip("'\" ")
initial_spec._add_flag(name, value, propagate=True)
elif self.ctx.expect(TokenType.DAG_HASH):
if initial_spec.abstract_hash:
break
self.ctx.accept(TokenType.DAG_HASH)
initial_spec.abstract_hash = self.ctx.current_token.value[1:]
else:
break
return initial_spec
[docs] def hash_not_parsed_or_raise(self, spec, addition):
if not self.has_hash:
return
raise spack.spec.RedundantSpecError(spec, addition)
[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.spec.NoSuchSpecFileError(f"No such spec file: '{file}'")
with file.open("r", encoding="utf-8") as stream:
if str(file).endswith(".json"):
spec_from_file = spack.spec.Spec.from_json(stream)
else:
spec_from_file = spack.spec.Spec.from_yaml(stream)
initial_spec._dup(spec_from_file)
return initial_spec
[docs]def parse(text: str) -> List[spack.spec.Spec]:
"""Parse text into a list of strings
Args:
text (str): text to be parsed
Return:
List of specs
"""
return SpecParser(text).all_specs()
[docs]def parse_one_or_raise(
text: str, initial_spec: Optional[spack.spec.Spec] = None
) -> spack.spec.Spec:
"""Parse exactly one spec from text and return it, or raise
Args:
text (str): text to be parsed
initial_spec: buffer where to parse the spec. If None a new one will be created.
"""
stripped_text = text.strip()
parser = SpecParser(stripped_text)
result = parser.next_spec(initial_spec)
last_token = parser.ctx.current_token
if last_token is not None and last_token.end != len(stripped_text):
message = "a single spec was requested, but parsed more than one:"
message += f"\n{text}"
if last_token is not None:
underline = f"\n{' ' * last_token.end}{'^' * (len(text) - last_token.end)}"
message += color.colorize(f"@*r{{{underline}}}")
raise ValueError(message)
if result is None:
message = "a single spec was requested, but none was parsed:"
message += f"\n{text}"
raise ValueError(message)
return result
[docs]class SpecSyntaxError(Exception):
"""Base class for Spec syntax errors"""
[docs]class SpecTokenizationError(SpecSyntaxError):
"""Syntax error in a spec string"""
def __init__(self, matches, text):
message = "unexpected tokens in the spec string\n"
message += f"{text}"
underline = "\n"
for match in matches:
if match.lastgroup == str(ErrorTokenType.UNEXPECTED):
underline += f"{'^' * (match.end() - match.start())}"
continue
underline += f"{' ' * (match.end() - match.start())}"
message += color.colorize(f"@*r{{{underline}}}")
super().__init__(message)
[docs]class SpecParsingError(SpecSyntaxError):
"""Error when parsing tokens"""
def __init__(self, message, token, text):
message += f"\n{text}"
underline = f"\n{' '*token.start}{'^'*(token.end - token.start)}"
message += color.colorize(f"@*r{{{underline}}}")
super().__init__(message)