[PATCH v7 07/17] docs: sphinx: add a parser for yaml files for Netlink specs

Add a simple sphinx.Parser to handle yaml files and add the
the code to handle Netlink specs. All other yaml files are
ignored.

The code was written in a way that parsing yaml for different
subsystems and even for different parts of Netlink are easy.

All it takes to have a different parser is to add an
import line similar to:

	from netlink_yml_parser import YnlDocGenerator

adding the corresponding parser somewhere at the extension:

	netlink_parser = YnlDocGenerator()

And then add a logic inside parse() to handle different
doc outputs, depending on the file location, similar to:

        if "/netlink/specs/" in fname:
            msg = self.netlink_parser.parse_yaml_file(fname)

Signed-off-by: Mauro Carvalho Chehab <[email protected]>
---
 Documentation/sphinx/parser_yaml.py | 76 +++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100755 Documentation/sphinx/parser_yaml.py

diff --git a/Documentation/sphinx/parser_yaml.py b/Documentation/sphinx/parser_yaml.py
new file mode 100755
index 000000000000..635945e1c5ba
--- /dev/null
+++ b/Documentation/sphinx/parser_yaml.py
@@ -0,0 +1,76 @@
+"""
+Sphinx extension for processing YAML files
+"""
+
+import os
+import re
+import sys
+
+from pprint import pformat
+
+from docutils.parsers.rst import Parser as RSTParser
+from docutils.statemachine import ViewList
+
+from sphinx.util import logging
+from sphinx.parsers import Parser
+
+srctree = os.path.abspath(os.environ["srctree"])
+sys.path.insert(0, os.path.join(srctree, "tools/net/ynl/pyynl"))
+
+from netlink_yml_parser import YnlDocGenerator        # pylint: disable=C0413
+
+logger = logging.getLogger(__name__)
+
+class YamlParser(Parser):
+    """Custom parser for YAML files."""
+
+    # Need at least two elements on this set
+    supported = ('yaml', 'yml')
+
+    netlink_parser = YnlDocGenerator()
+
+    def do_parse(self, inputstring, document, msg):
+        """Parse YAML and generate a document tree."""
+
+        self.setup_parse(inputstring, document)
+
+        result = ViewList()
+
+        try:
+            # Parse message with RSTParser
+            for i, line in enumerate(msg.split('\n')):
+                result.append(line, document.current_source, i)
+
+            rst_parser = RSTParser()
+            rst_parser.parse('\n'.join(result), document)
+
+        except Exception as e:
+            document.reporter.error("YAML parsing error: %s" % pformat(e))
+
+        self.finish_parse()
+
+    # Overrides docutils.parsers.Parser. See sphinx.parsers.RSTParser
+    def parse(self, inputstring, document):
+        """Check if a YAML is meant to be parsed."""
+
+        fname = document.current_source
+
+        # Handle netlink yaml specs
+        if "/netlink/specs/" in fname:
+            msg = self.netlink_parser.parse_yaml_file(fname)
+            self.do_parse(inputstring, document, msg)
+
+        # All other yaml files are ignored
+
+def setup(app):
+    """Setup function for the Sphinx extension."""
+
+    # Add YAML parser
+    app.add_source_parser(YamlParser)
+    app.add_source_suffix('.yaml', 'yaml')
+
+    return {
+        'version': '1.0',
+        'parallel_read_safe': True,
+        'parallel_write_safe': True,
+    }
-- 
2.49.0