# 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 Iterator, List, Optional
from llnl.util.tty import color
import spack.deptypes
import spack.error
import spack.spec
import spack.version
from spack.tokenize import Token, TokenBase, Tokenizer
#: 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}))"
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}))*"
#: Regex with groups to use for splitting (optionally propagated) key-value pairs
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 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
START_EDGE_PROPERTIES = r"(?:\^\[)"
END_EDGE_PROPERTIES = r"(?:\])"
DEPENDENCY = r"(?:\^)"
# 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}))"
# 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+)"
# 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]
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: 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 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]
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 != SpecTokens.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 != 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:
root_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
initial_spec = initial_spec or spack.spec.Spec()
root_spec = SpecNodeParser(self.ctx, self.literal_str).parse(initial_spec)
while True:
if self.ctx.accept(SpecTokens.START_EDGE_PROPERTIES):
edge_properties = EdgeAttributeParser(self.ctx, self.literal_str).parse()
edge_properties.setdefault("depflag", 0)
edge_properties.setdefault("virtuals", ())
dependency = self._parse_node(root_spec)
add_dependency(dependency, **edge_properties)
elif self.ctx.accept(SpecTokens.DEPENDENCY):
dependency = self._parse_node(root_spec)
add_dependency(dependency, depflag=0, virtuals=())
else:
break
return root_spec
def _parse_node(self, root_spec):
dependency = SpecNodeParser(self.ctx, self.literal_str).parse()
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.spec.RedundantSpecError(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_compiler", "has_version", "literal_str"
def __init__(self, ctx, literal_str):
self.ctx = ctx
self.literal_str = literal_str
self.has_compiler = False
self.has_version = 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(SpecTokens.DEPENDENCY):
return initial_spec
if initial_spec is None:
initial_spec = 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(SpecTokens.UNQUALIFIED_PACKAGE_NAME):
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: str, propagate: bool):
"""Wrapper around ``Spec._add_flag()`` that adds parser context to errors raised."""
try:
initial_spec._add_flag(name, value, propagate)
except Exception as e:
raise_parsing_error(str(e), e)
while True:
if self.ctx.accept(SpecTokens.COMPILER):
if self.has_compiler:
raise_parsing_error("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(SpecTokens.COMPILER_AND_VERSION):
if self.has_compiler:
raise_parsing_error("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(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):
variant_value = self.ctx.current_token.value[0] == "+"
add_flag(self.ctx.current_token.value[1:].strip(), variant_value, propagate=False)
elif self.ctx.accept(SpecTokens.PROPAGATED_BOOL_VARIANT):
variant_value = self.ctx.current_token.value[0:2] == "++"
add_flag(self.ctx.current_token.value[2:].strip(), variant_value, propagate=True)
elif self.ctx.accept(SpecTokens.KEY_VALUE_PAIR):
match = SPLIT_KVP.match(self.ctx.current_token.value)
assert match, "SPLIT_KVP and KEY_VALUE_PAIR do not agree."
name, _, value = match.groups()
add_flag(name, strip_quotes_and_unescape(value), propagate=False)
elif self.ctx.accept(SpecTokens.PROPAGATED_KEY_VALUE_PAIR):
match = SPLIT_KVP.match(self.ctx.current_token.value)
assert match, "SPLIT_KVP and PROPAGATED_KEY_VALUE_PAIR do not agree."
name, _, value = match.groups()
add_flag(name, strip_quotes_and_unescape(value), propagate=True)
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.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]
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)
name = name.strip("'\" ")
value = value.strip("'\" ").split(",")
attributes[name] = value
if name not in ("deptypes", "virtuals"):
msg = (
"the only edge attributes that are currently accepted "
'are "deptypes" and "virtuals"'
)
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):
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)
return attributes
[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 SpecParsingError(spack.error.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)
[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 ``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}'"