[PATCH v3 54/63] docs/qapidoc: implement transmogrify() method

[John Snow <jsnow@redhat.com>]

This is the true top-level processor for the new transmogrifier;
responsible both for generating the intermediate rST and then running
the nested parse on that generated document to produce the final
docutils tree that is then - very finally - postprocessed by sphinx for
final rendering to HTML &c.

Signed-off-by: John Snow <jsnow@redhat.com>
---
 docs/sphinx/qapidoc.py | 49 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 47 insertions(+), 2 deletions(-)

diff --git a/docs/sphinx/qapidoc.py b/docs/sphinx/qapidoc.py
index aaf5b6e22bc..32baf66a390 100644
--- a/docs/sphinx/qapidoc.py
+++ b/docs/sphinx/qapidoc.py
@@ -2,6 +2,7 @@
 #
 # QEMU qapidoc QAPI file parsing extension
 #
+# Copyright (c) 2024-2025 Red Hat
 # Copyright (c) 2020 Linaro
 #
 # This work is licensed under the terms of the GNU GPLv2 or later.
@@ -56,6 +57,7 @@
 from sphinx import addnodes
 from sphinx.directives.code import CodeBlock
 from sphinx.errors import ExtensionError
+from sphinx.util import logging
 from sphinx.util.docutils import switch_source_input
 from sphinx.util.nodes import nested_parse_with_titles
 
@@ -74,7 +76,9 @@
     from sphinx.util.typing import ExtensionMetadata
 
 
-__version__ = "1.0"
+__version__ = "2.0"
+
+logger = logging.getLogger(__name__)
 
 
 class Transmogrifier:
@@ -95,6 +99,10 @@ def __init__(self) -> None:
         self._result = StringList()
         self.indent = 0
 
+    @property
+    def result(self) -> StringList:
+        return self._result
+
     @property
     def entity(self) -> QAPISchemaDefinition:
         assert self._curr_ent is not None
@@ -438,7 +446,43 @@ def new_serialno(self) -> str:
         return "qapidoc-%d" % env.new_serialno("qapidoc")
 
     def transmogrify(self, schema: QAPISchema) -> nodes.Element:
-        raise NotImplementedError
+        logger.info("Transmogrifying QAPI to rST ...")
+        vis = Transmogrifier()
+        modules = set()
+
+        for doc in schema.docs:
+            module_source = doc.info.fname
+            if module_source not in modules:
+                vis.visit_module(module_source)
+                modules.add(module_source)
+
+            if doc.symbol:
+                ent = schema.lookup_entity(doc.symbol)
+                assert isinstance(ent, QAPISchemaDefinition)
+                vis.visit_entity(ent)
+            else:
+                vis.visit_freeform(doc)
+
+        logger.info("Transmogrification complete.")
+
+        contentnode = nodes.section()
+        content = vis.result
+        titles_allowed = True
+
+        logger.info("Transmogrifier running nested parse ...")
+        with switch_source_input(self.state, content):
+            if titles_allowed:
+                node: nodes.Element = nodes.section()
+                node.document = self.state.document
+                nested_parse_with_titles(self.state, content, contentnode)
+            else:
+                node = nodes.paragraph()
+                node.document = self.state.document
+                self.state.nested_parse(content, 0, contentnode)
+        logger.info("Transmogrifier's nested parse completed.")
+        sys.stdout.flush()
+
+        return contentnode
 
     def legacy(self, schema: QAPISchema) -> nodes.Element:
         vis = QAPISchemaGenRSTVisitor(self)
@@ -572,6 +616,7 @@ def run(self) -> List[nodes.Node]:
 
 def setup(app: Sphinx) -> ExtensionMetadata:
     """Register qapi-doc directive with Sphinx"""
+    app.setup_extension("qapi_domain")
     app.add_config_value("qapidoc_srctree", None, "env")
     app.add_directive("qapi-doc", QAPIDocDirective)
     app.add_directive("qmp-example", QMPExample)
-- 
2.48.1