Re: [PATCH v2 00/12] Thrash up the parser/output interface

[Mauro Carvalho Chehab <mchehab+huawei@kernel.org>]

Em Fri, 11 Jul 2025 13:29:00 +0900
Akira Yokosawa <akiyks@gmail.com> escreveu:

> On Thu, 10 Jul 2025 17:31:30 -0600, Jonathan Corbet wrote:
> [...]
> 
> > Changes since v1:
> > - Coding-style tweaks requested by Mauro
> > - Drop the reworking of output-text accumulation for now
> > - Add a warning for prehistoric Python versions  
> 
> Serious review of python code is beyond my background, but I did a test
> on this against opensuse/leap:15.6's python3-Sphinx_4_2_0, which comes with
> python 3.6.15.
> 
> Running "./scripts/kernel-doc.py -none include/linux/rcupdate.h" emits this:
> 
> ------------------------------------------------------------------------
> Traceback (most recent call last):
>   File "./scripts/kernel-doc.py", line 315, in <module>
>     main()
>   File "./scripts/kernel-doc.py", line 286, in main
>     kfiles.parse(args.files, export_file=args.export_file)
>   File "/linux/scripts/lib/kdoc/kdoc_files.py", line 222, in parse
>     self.parse_file(fname)
>   File "/linux/scripts/lib/kdoc/kdoc_files.py", line 119, in parse_file
>     doc = KernelDoc(self.config, fname)
>   File "/linux/scripts/lib/kdoc/kdoc_parser.py", line 247, in __init__
>     self.emit_message(0,
> AttributeError: 'KernelDoc' object has no attribute 'emit_message'
> ------------------------------------------------------------------------
> 
> This error appeared in 12/12.  No errors with python3 >=3.9.

This is actually a bug. See:

	+        #
	+        # We need Python 3.7 for its "dicts remember the insertion
	+        # order" guarantee
	+        #
	+        if sys.version_info.major == 3 and sys.version_info.minor < 7:
	+            self.emit_message(0,
	+                              'Python 3.7 or later is required for correct results')
	+
	     def emit_msg(self, ln, msg, warning=True):
	         """Emit a message"""

The answer is just below the modified code: the function name is actually:
	self.emit_msg()

> I'm not sure but asking compatibility with python <3.9 increases
> maintainers/testers' burden.  Obsoleting <3.9 all together would
> make everyone's life easier, wouldn't it?

I'd say that the best is to have:

scripts/sphinx-pre-install:

- be compatible with Python 3.6, as it is needed to detect and
  request Python upgrades where needed.

- For the doc build, based on my tests with the pre-install tool,
  all distros on my testlist have at least Python >= 3.9 as optional
  packages.

Now, kernel-doc is a special case, as it is called during Kernel
builds, with "-none". In the specific case of this patchset, running
Python 3.6 would randomize the order of struct and function arguments.
Not a problem when "-none" is used. So, compilation should not
break.

Shifting kernel-doc minimal version to Python >= 3.9, will
require an extra logic at kerneldoc to abort early if "-none"
is used with too old Python, as otherwise it will break kernel
builds for RHEL8, OpenSUSE Leap, OpenMandriva Lx 4.3 and to 
other distros (those three comes with 3.6).

Jon,

I sent a two-patches series addressing such issues with kernel-doc
exec file.

I would keep patch 12/12, fixing it from:

	 self.emit_message -> self.emit_msg

as the warning is emitted when using kdoc classes, which is now the
default.

-

Btw, if you use Fedora, you can easily install python 3.6 there via 
dnf:

	$ dnf search python 3.6
	Updating and loading repositories:
	Repositories loaded.
	Matched fields: name, summary
	 python3.6.i686: Version 3.6 of the Python interpreter
	 python3.6.x86_64: Version 3.6 of the Python interpreter

	(Fedora 42 also have all python versions from 3.9 to 3.14 beta also
	 via dnf)

Regards,
Mauro