docs: kernel_include.py: remove Include class inheritance

While the original code came from the Sphinx Include class,
such class is monolithic: it has only one function that does
everything, and 3 variables that are used:

	- required_arguments
	- optional_arguments
	- option_spec

So, basically those are the only members that remain from
the original class, but hey! Those are the same vars that every
other Sphinx directive extension has to define!

In summary, keeping inheritance here doesn't make much sense.

Worse than that, kernel-include doesn't support the current set
of options that the original Include class has, but it also
has its own set of options.

So, let's fill in the argument vars with what it does
support, dropping the rest.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/a9f2eebf11c6b0c3a2e3bf42e71392cdfd2835d1.1755872208.git.mchehab+huawei@kernel.org

Documentation/sphinx/kernel_include.py

@@ -62,9 +62,8 @@ import sys
 from docutils import io, nodes, statemachine
 from docutils.statemachine import ViewList
 from docutils.utils.error_reporting import SafeString, ErrorString
-from docutils.parsers.rst import directives
+from docutils.parsers.rst import Directive, directives
 from docutils.parsers.rst.directives.body import CodeBlock, NumberLines
-from docutils.parsers.rst.directives.misc import Include
 
 from sphinx.util import logging
 
@@ -81,18 +80,43 @@ RE_SIMPLE_REF = re.compile(r'`([^`]+)`')
 
 
 # ==============================================================================
-class KernelInclude(Include):
-    """KernelInclude (``kernel-include``) directive"""
+class KernelInclude(Directive):
+    """
+    KernelInclude (``kernel-include``) directive
 
-    # Add extra options
-    option_spec = Include.option_spec.copy()
+    Most of the stuff here came from Include directive defined at:
+        docutils/parsers/rst/directives/misc.py
 
-    option_spec.update({
+    Yet, overriding the class don't has any benefits: the original class
+    only have run() and argument list. Not all of them are implemented,
+    when checked against latest Sphinx version, as with time more arguments
+    were added.
+
+    So, keep its own list of supported arguments
+    """
+
+    required_arguments = 1
+    optional_arguments = 0
+    final_argument_whitespace = True
+    option_spec = {
+        'literal': directives.flag,
+        'code': directives.unchanged,
+        'encoding': directives.encoding,
+        'tab-width': int,
+        'start-line': int,
+        'end-line': int,
+        'start-after': directives.unchanged_required,
+        'end-before': directives.unchanged_required,
+        # ignored except for 'literal' or 'code':
+        'number-lines': directives.unchanged,  # integer or None
+        'class': directives.class_option,
+
+        # Arguments that aren't from Sphinx Include directive
         'generate-cross-refs': directives.flag,
         'warn-broken': directives.flag,
         'toc': directives.flag,
         'exception-file': directives.unchanged,
-    })
+    }
 
     def read_rawtext(self, path, encoding):
             """Read and process file content with error handling"""