[autodoc] Fix uncatched exception in get type hints

[yanyongyu]

Subject: Fix uncatched exception in get type hints

Feature or Bugfix

• Bugfix

Purpose

• get_type_hints by autodoc from not runtime checkable ForwardRef may cause AttributeError instead of NameError

Detail

Some modules like loguru provide a stub file include types defined not at runtime. As mentioned in mypy stub file guide, these types may cause errors if used in runtime.

Error occured because of the following code in autodoc:

sphinx/sphinx/ext/autodoc/__init__.py

Lines 1981 to 2005 in f590268

	def add_directive_header(self, sig: str) -> None:
	super().add_directive_header(sig)
	sourcename = self.get_sourcename()
	if self.options.annotation is SUPPRESS or self.should_suppress_directive_header():
	pass
	elif self.options.annotation:
	self.add_line(' :annotation: %s' % self.options.annotation,
	sourcename)
	else:
	if self.config.autodoc_typehints != 'none':
	# obtain annotation for this data
	annotations = get_type_hints(self.parent, None,
	self.config.autodoc_type_aliases)
	if self.objpath[-1] in annotations:
	objrepr = stringify_typehint(annotations.get(self.objpath[-1]))
	self.add_line(' :type: ' + objrepr, sourcename)
	try:
	if self.options.no_value or self.should_suppress_value_header():
	pass
	else:
	objrepr = object_description(self.object)
	self.add_line(' :value: ' + objrepr, sourcename)
	except ValueError:
	pass

Following Code will raise AttributeError when building:

import loguru

# loguru.Logger not exists at runtime actually
my_logger: "loguru.Logger" = loguru.logger

Following Code will be processed successfully (NameError has been caught):

from typing import TYPE_CHECKING

import loguru

if TYPE_CHECKING:
	from loguru import Logger

my_logger: "Logger" = loguru.logger

If AttributeError is catched in get_type_hints, these ForwardRef will be treated as raw string and building will be successful. But, i dont know if this change may cause some unexpected building success.

Full Example

Repo: https://github.com/yanyongyu/loguru-issue480

Build Log: https://github.com/yanyongyu/loguru-issue480/runs/3177938743

Relates

• Something error in loguru stub file Delgan/loguru#480

[tk0miya]

Could merge the HEAD of 4.x branch, please? Then, CI will become passed.

[yanyongyu]

Could merge the HEAD of 4.x branch, please? Then, CI will become passed.

Merged now.

[tk0miya]

Merged. Thank you for your work!