xref: /linux/Documentation/sphinx/parser_yaml.py (revision d2b007374551ac09db16badde575cdd698f6fc92) 
1# SPDX-License-Identifier: GPL-2.0
2# Copyright 2025 Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
3
4"""
5Sphinx extension for processing YAML files
6"""
7
8import os
9import re
10import sys
11
12from pprint import pformat
13
14from docutils import statemachine
15from docutils.parsers.rst import Parser as RSTParser
16from docutils.parsers.rst import states
17from docutils.statemachine import ViewList
18
19from sphinx.util import logging
20from sphinx.parsers import Parser
21
22srctree = os.path.abspath(os.environ["srctree"])
23sys.path.insert(0, os.path.join(srctree, "tools/net/ynl/pyynl/lib"))
24
25from doc_generator import YnlDocGenerator        # pylint: disable=C0413
26
27logger = logging.getLogger(__name__)
28
29class YamlParser(Parser):
30    """
31    Kernel parser for YAML files.
32
33    This is a simple sphinx.Parser to handle yaml files inside the
34    Kernel tree that will be part of the built documentation.
35
36    The actual parser function is not contained here: the code was
37    written in a way that parsing yaml for different subsystems
38    can be done from a single dispatcher.
39
40    All it takes to have parse YAML patches is to have an import line:
41
42            from some_parser_code import NewYamlGenerator
43
44    To this module. Then add an instance of the parser with:
45
46            new_parser = NewYamlGenerator()
47
48    and add a logic inside parse() to handle it based on the path,
49    like this:
50
51            if "/foo" in fname:
52                msg = self.new_parser.parse_yaml_file(fname)
53    """
54
55    supported = ('yaml', )
56
57    netlink_parser = YnlDocGenerator()
58
59    re_lineno = re.compile(r"\.\. LINENO ([0-9]+)$")
60
61    tab_width = 8
62
63    def rst_parse(self, inputstring, document, msg):
64        """
65        Receives a ReST content that was previously converted by the
66        YAML parser, adding it to the document tree.
67        """
68
69        self.setup_parse(inputstring, document)
70
71        result = ViewList()
72
73        self.statemachine = states.RSTStateMachine(state_classes=states.state_classes,
74                                                   initial_state='Body',
75                                                   debug=document.reporter.debug_flag)
76
77        try:
78            # Parse message with RSTParser
79            lineoffset = 0;
80
81            lines = statemachine.string2lines(msg, self.tab_width,
82                                              convert_whitespace=True)
83
84            for line in lines:
85                match = self.re_lineno.match(line)
86                if match:
87                    lineoffset = int(match.group(1))
88                    continue
89
90                result.append(line, document.current_source, lineoffset)
91
92            self.statemachine.run(result, document)
93
94        except Exception as e:
95            document.reporter.error("YAML parsing error: %s" % pformat(e))
96
97        self.finish_parse()
98
99    # Overrides docutils.parsers.Parser. See sphinx.parsers.RSTParser
100    def parse(self, inputstring, document):
101        """Check if a YAML is meant to be parsed."""
102
103        fname = document.current_source
104
105        # Handle netlink yaml specs
106        if "/netlink/specs/" in fname:
107            msg = self.netlink_parser.parse_yaml_file(fname)
108            self.rst_parse(inputstring, document, msg)
109
110        # All other yaml files are ignored
111
112def setup(app):
113    """Setup function for the Sphinx extension."""
114
115    # Add YAML parser
116    app.add_source_parser(YamlParser)
117    app.add_source_suffix('.yaml', 'yaml')
118
119    return {
120        'version': '1.0',
121        'parallel_read_safe': True,
122        'parallel_write_safe': True,
123    }
124