scripts/kerneldoc: Switch to the Python kernel-doc script

Change the Sphinx config to run the new Python kernel-doc script
instead of the Perl one.  The only difference between the two is that
the new script does not handle the -sphinx-version option, instead
assuming that Sphinx is always at least version 3: so we must
delete the code that passes that option to avoid the Python
script complaining about an unknown option.

QEMU's minimum Sphinx version is already 3.4.3, so this doesn't
change the set of versions we can handle.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Message-id: 20250814171324.1614516-7-peter.maydell@linaro.org

docs/conf.py

@@ -341,7 +341,9 @@ man_make_section_directory = False
 # We use paths starting from qemu_docdir here so that you can run
 # sphinx-build from anywhere and the kerneldoc extension can still
 # find everything.
-kerneldoc_bin = ['perl', os.path.join(qemu_docdir, '../scripts/kernel-doc')]
+# Since kernel-doc is now a Python script, we should run it with whatever
+# Python this sphinx is using (rather than letting it find one via env)
+kerneldoc_bin = [sys.executable, os.path.join(qemu_docdir, '../scripts/kernel-doc.py')]
 kerneldoc_srctree = os.path.join(qemu_docdir, '..')
 hxtool_srctree = os.path.join(qemu_docdir, '..')
 qapidoc_srctree = os.path.join(qemu_docdir, '..')

docs/sphinx/kerneldoc.py

@@ -63,11 +63,6 @@ class KernelDocDirective(Directive):
         env = self.state.document.settings.env
         cmd = env.config.kerneldoc_bin + ['-rst', '-enable-lineno']
 
-        # Pass the version string to kernel-doc, as it needs to use a different
-        # dialect, depending what the C domain supports for each specific
-        # Sphinx versions
-        cmd += ['-sphinx-version', sphinx.__version__]
-
         # Pass through the warnings-as-errors flag
         if env.config.kerneldoc_werror:
             cmd += ['-Werror']