Documentation/sphinx: add Sphinx kernel-doc directive extension

# coding=utf-8

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# Copyright © 2016 Intel Corporation

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# Authors:

#    Jani Nikula <jani.nikula@intel.com>

import os

import subprocess

import sys

from docutils import nodes, statemachine

from docutils.parsers.rst import directives

from sphinx.util.compat import Directive

class KernelDocDirective(Directive):

    """Extract kernel-doc comments from the specified file"""

    required_argument = 1

    optional_arguments = 4

    option_spec = {

        'doc': directives.unchanged_required,

        'functions': directives.unchanged_required,

        'export': directives.flag,

        'internal': directives.flag,

    }

    has_content = False

    def run(self):

        env = self.state.document.settings.env

        cmd = [env.config.kerneldoc_bin, '-rst']

        filename = env.config.kerneldoc_srctree + '/' + self.arguments[0]

        # Tell sphinx of the dependency

        env.note_dependency(os.path.abspath(filename))

        tab_width = self.options.get('tab-width', self.state.document.settings.tab_width)

        source = self.state_machine.input_lines.source(self.lineno - self.state_machine.input_offset - 1)

        # FIXME: make this nicer and more robust against errors

        if 'export' in self.options:

            cmd += ['-export']

        elif 'internal' in self.options:

            cmd += ['-internal']

        elif 'doc' in self.options:

            cmd += ['-function', str(self.options.get('doc'))]

        elif 'functions' in self.options:

            for f in str(self.options.get('functions')).split(' '):

                cmd += ['-function', f]

        cmd += [filename]

        try:

            env.app.verbose('calling kernel-doc \'%s\'' % (" ".join(cmd)))

            p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)

            out, err = p.communicate()

            # assume the kernel sources are utf-8

            out, err = unicode(out, 'utf-8'), unicode(err, 'utf-8')

            if p.returncode != 0:

                sys.stderr.write(err)

                env.app.warn('kernel-doc \'%s\' failed with return code %d' % (" ".join(cmd), p.returncode))

                return [nodes.error(None, nodes.paragraph(text = "kernel-doc missing"))]

            elif env.config.kerneldoc_verbosity > 0:

                sys.stderr.write(err)

            lines = statemachine.string2lines(out, tab_width, convert_whitespace=True)

            self.state_machine.insert_input(lines, source)

            return []

        except Exception as e:

            env.app.warn('kernel-doc \'%s\' processing failed with: %s' %

                         (" ".join(cmd), str(e)))

            return [nodes.error(None, nodes.paragraph(text = "kernel-doc missing"))]

def setup(app):

    app.add_config_value('kerneldoc_bin', None, 'env')

    app.add_config_value('kerneldoc_srctree', None, 'env')

    app.add_config_value('kerneldoc_verbosity', 1, 'env')

    app.add_directive('kernel-doc', KernelDocDirective)