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#######################################################################################
#
# Adapted from:
# https://github.com/pypa/hatch/blob/5352e44/backend/src/hatchling/licenses/parse.py
#
# MIT License
#
# Copyright (c) 2017-present Ofek Lev <oss@ofek.dev>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy of this
# software and associated documentation files (the "Software"), to deal in the Software
# without restriction, including without limitation the rights to use, copy, modify,
# merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to the following
# conditions:
#
# The above copyright notice and this permission notice shall be included in all copies
# or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
# INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
# PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
# CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
# OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
#
# With additional allowance of arbitrary `LicenseRef-` identifiers, not just
# `LicenseRef-Public-Domain` and `LicenseRef-Proprietary`.
#
#######################################################################################
from __future__ import annotations
import re
from typing import NewType, cast
from pip._vendor.packaging.licenses._spdx import EXCEPTIONS, LICENSES
__all__ = [
"NormalizedLicenseExpression",
"InvalidLicenseExpression",
"canonicalize_license_expression",
]
license_ref_allowed = re.compile("^[A-Za-z0-9.-]*$")
NormalizedLicenseExpression = NewType("NormalizedLicenseExpression", str)
class InvalidLicenseExpression(ValueError):
"""Raised when a license-expression string is invalid
>>> canonicalize_license_expression("invalid")
Traceback (most recent call last):
...
packaging.licenses.InvalidLicenseExpression: Invalid license expression: 'invalid'
"""
def canonicalize_license_expression(
raw_license_expression: str,
) -> NormalizedLicenseExpression:
if not raw_license_expression:
message = f"Invalid license expression: {raw_license_expression!r}"
raise InvalidLicenseExpression(message)
# Pad any parentheses so tokenization can be achieved by merely splitting on
# whitespace.
license_expression = raw_license_expression.replace("(", " ( ").replace(")", " ) ")
licenseref_prefix = "LicenseRef-"
license_refs = {
ref.lower(): "LicenseRef-" + ref[len(licenseref_prefix) :]
for ref in license_expression.split()
if ref.lower().startswith(licenseref_prefix.lower())
}
# Normalize to lower case so we can look up licenses/exceptions
# and so boolean operators are Python-compatible.
license_expression = license_expression.lower()
tokens = license_expression.split()
# Rather than implementing boolean logic, we create an expression that Python can
# parse. Everything that is not involved with the grammar itself is treated as
# `False` and the expression should evaluate as such.
python_tokens = []
for token in tokens:
if token not in {"or", "and", "with", "(", ")"}:
python_tokens.append("False")
elif token == "with":
python_tokens.append("or")
elif token == "(" and python_tokens and python_tokens[-1] not in {"or", "and"}:
message = f"Invalid license expression: {raw_license_expression!r}"
raise InvalidLicenseExpression(message)
else:
python_tokens.append(token)
python_expression = " ".join(python_tokens)
try:
invalid = eval(python_expression, globals(), locals())
except Exception:
invalid = True
if invalid is not False:
message = f"Invalid license expression: {raw_license_expression!r}"
raise InvalidLicenseExpression(message) from None
# Take a final pass to check for unknown licenses/exceptions.
normalized_tokens = []
for token in tokens:
if token in {"or", "and", "with", "(", ")"}:
normalized_tokens.append(token.upper())
continue
if normalized_tokens and normalized_tokens[-1] == "WITH":
if token not in EXCEPTIONS:
message = f"Unknown license exception: {token!r}"
raise InvalidLicenseExpression(message)
normalized_tokens.append(EXCEPTIONS[token]["id"])
else:
if token.endswith("+"):
final_token = token[:-1]
suffix = "+"
else:
final_token = token
suffix = ""
if final_token.startswith("licenseref-"):
if not license_ref_allowed.match(final_token):
message = f"Invalid licenseref: {final_token!r}"
raise InvalidLicenseExpression(message)
normalized_tokens.append(license_refs[final_token] + suffix)
else:
if final_token not in LICENSES:
message = f"Unknown license: {final_token!r}"
raise InvalidLicenseExpression(message)
normalized_tokens.append(LICENSES[final_token]["id"] + suffix)
normalized_expression = " ".join(normalized_tokens)
return cast(
NormalizedLicenseExpression,
normalized_expression.replace("( ", "(").replace(" )", ")"),
)
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