1 files changed, 104 insertions, 0 deletions
diff --git a/third_party/python/setuptools/setuptools/warnings.py b/third_party/python/setuptools/setuptools/warnings.py
new file mode 100644
index 0000000000..4ea782e509
--- /dev/null
+++ b/third_party/python/setuptools/setuptools/warnings.py
@@ -0,0 +1,104 @@
+"""Provide basic warnings used by setuptools modules.
+
+Using custom classes (other than ``UserWarning``) allow users to set
+``PYTHONWARNINGS`` filters to run tests and prepare for upcoming changes in
+setuptools.
+"""
+
+import os
+import warnings
+from datetime import date
+from inspect import cleandoc
+from textwrap import indent
+from typing import Optional, Tuple
+
+_DueDate = Tuple[int, int, int]  # time tuple
+_INDENT = 8 * " "
+_TEMPLATE = f"""{80 * '*'}\n{{details}}\n{80 * '*'}"""
+
+
+class SetuptoolsWarning(UserWarning):
+    """Base class in ``setuptools`` warning hierarchy."""
+
+    @classmethod
+    def emit(
+        cls,
+        summary: Optional[str] = None,
+        details: Optional[str] = None,
+        due_date: Optional[_DueDate] = None,
+        see_docs: Optional[str] = None,
+        see_url: Optional[str] = None,
+        stacklevel: int = 2,
+        **kwargs
+    ):
+        """Private: reserved for ``setuptools`` internal use only"""
+        # Default values:
+        summary_ = summary or getattr(cls, "_SUMMARY", None) or ""
+        details_ = details or getattr(cls, "_DETAILS", None) or ""
+        due_date = due_date or getattr(cls, "_DUE_DATE", None)
+        docs_ref = see_docs or getattr(cls, "_SEE_DOCS", None)
+        docs_url = docs_ref and f"https://setuptools.pypa.io/en/latest/{docs_ref}"
+        see_url = see_url or getattr(cls, "_SEE_URL", None)
+        due = date(*due_date) if due_date else None
+
+        text = cls._format(summary_, details_, due, see_url or docs_url, kwargs)
+        if due and due < date.today() and _should_enforce():
+            raise cls(text)
+        warnings.warn(text, cls, stacklevel=stacklevel + 1)
+
+    @classmethod
+    def _format(
+        cls,
+        summary: str,
+        details: str,
+        due_date: Optional[date] = None,
+        see_url: Optional[str] = None,
+        format_args: Optional[dict] = None,
+    ):
+        """Private: reserved for ``setuptools`` internal use only"""
+        today = date.today()
+        summary = cleandoc(summary).format_map(format_args or {})
+        possible_parts = [
+            cleandoc(details).format_map(format_args or {}),
+            (
+                f"\nBy {due_date:%Y-%b-%d}, you need to update your project and remove "
+                "deprecated calls\nor your builds will no longer be supported."
+                if due_date and due_date > today else None
+            ),
+            (
+                "\nThis deprecation is overdue, please update your project and remove "
+                "deprecated\ncalls to avoid build errors in the future."
+                if due_date and due_date < today else None
+            ),
+            (f"\nSee {see_url} for details." if see_url else None)
+
+        ]
+        parts = [x for x in possible_parts if x]
+        if parts:
+            body = indent(_TEMPLATE.format(details="\n".join(parts)), _INDENT)
+            return "\n".join([summary, "!!\n", body, "\n!!"])
+        return summary
+
+
+class InformationOnly(SetuptoolsWarning):
+    """Currently there is no clear way of displaying messages to the users
+    that use the setuptools backend directly via ``pip``.
+    The only thing that might work is a warning, although it is not the
+    most appropriate tool for the job...
+
+    See pypa/packaging-problems#558.
+    """
+
+
+class SetuptoolsDeprecationWarning(SetuptoolsWarning):
+    """
+    Base class for warning deprecations in ``setuptools``
+
+    This class is not derived from ``DeprecationWarning``, and as such is
+    visible by default.
+    """
+
+
+def _should_enforce():
+    enforce = os.getenv("SETUPTOOLS_ENFORCE_DEPRECATION", "false").lower()
+    return enforce in ("true", "on", "ok", "1")