3 # QEMU qapidoc QAPI file parsing extension
5 # Copyright (c) 2020 Linaro
7 # This work is licensed under the terms of the GNU GPLv2 or later.
8 # See the COPYING file in the top-level directory.
11 qapidoc is a Sphinx extension that implements the qapi-doc directive
13 The purpose of this extension is to read the documentation comments
14 in QAPI schema files, and insert them all into the current document.
16 It implements one new rST directive, "qapi-doc::".
17 Each qapi-doc:: directive takes one argument, which is the
18 pathname of the schema file to process, relative to the source tree.
20 The docs/conf.py file must set the qapidoc_srctree config value to
21 the root of the QEMU source tree.
23 The Sphinx documentation on writing extensions is at:
24 https://www.sphinx-doc.org/en/master/development/index.html
30 from docutils
import nodes
31 from docutils
.statemachine
import ViewList
32 from docutils
.parsers
.rst
import directives
, Directive
33 from sphinx
.errors
import ExtensionError
34 from sphinx
.util
.nodes
import nested_parse_with_titles
36 from qapi
.gen
import QAPISchemaVisitor
37 from qapi
.error
import QAPIError
, QAPISemError
38 from qapi
.schema
import QAPISchema
41 # Sphinx up to 1.6 uses AutodocReporter; 1.7 and later
42 # use switch_source_input. Check borrowed from kerneldoc.py.
43 Use_SSI
= sphinx
.__version
__[:3] >= '1.7'
45 from sphinx
.util
.docutils
import switch_source_input
47 from sphinx
.ext
.autodoc
import AutodocReporter
53 # Function borrowed from pydash, which is under the MIT license
54 def intersperse(iterable
, separator
):
55 """Yield the members of *iterable* interspersed with *separator*."""
56 iterable
= iter(iterable
)
63 class QAPISchemaGenRSTVisitor(QAPISchemaVisitor
):
64 """A QAPI schema visitor which generates docutils/Sphinx nodes
66 This class builds up a tree of docutils/Sphinx nodes corresponding
67 to documentation for the various QAPI objects. To use it, first
68 create a QAPISchemaGenRSTVisitor object, and call its
69 visit_begin() method. Then you can call one of the two methods
70 'freeform' (to add documentation for a freeform documentation
71 chunk) or 'symbol' (to add documentation for a QAPI symbol). These
72 will cause the visitor to build up the tree of document
73 nodes. Once you've added all the documentation via 'freeform' and
74 'symbol' method calls, you can call 'get_document_nodes' to get
75 the final list of document nodes (in a form suitable for returning
76 from a Sphinx directive's 'run' method).
78 def __init__(self
, sphinx_directive
):
80 self
._sphinx
_directive
= sphinx_directive
81 self
._top
_node
= nodes
.section()
82 self
._active
_headings
= [self
._top
_node
]
84 def _make_dlitem(self
, term
, defn
):
85 """Return a dlitem node with the specified term and definition.
87 term should be a list of Text and literal nodes.
88 defn should be one of:
89 - a string, which will be handed to _parse_text_into_node
90 - a list of Text and literal nodes, which will be put into
93 dlitem
= nodes
.definition_list_item()
94 dlterm
= nodes
.term('', '', *term
)
97 dldef
= nodes
.definition()
98 if isinstance(defn
, list):
99 dldef
+= nodes
.paragraph('', '', *defn
)
101 self
._parse
_text
_into
_node
(defn
, dldef
)
105 def _make_section(self
, title
):
106 """Return a section node with optional title"""
107 section
= nodes
.section(ids
=[self
._sphinx
_directive
.new_serialno()])
109 section
+= nodes
.title(title
, title
)
112 def _nodes_for_ifcond(self
, ifcond
, with_if
=True):
113 """Return list of Text, literal nodes for the ifcond
115 Return a list which gives text like ' (If: condition)'.
116 If with_if is False, we don't return the "(If: " and ")".
119 doc
= ifcond
.docgen()
122 doc
= nodes
.literal('', doc
)
126 nodelist
= [nodes
.Text(' ('), nodes
.strong('', 'If: ')]
128 nodelist
.append(nodes
.Text(')'))
131 def _nodes_for_one_member(self
, member
):
132 """Return list of Text, literal nodes for this member
134 Return a list of doctree nodes which give text like
135 'name: type (optional) (If: ...)' suitable for use as the
136 'term' part of a definition list item.
138 term
= [nodes
.literal('', member
.name
)]
139 if member
.type.doc_type():
140 term
.append(nodes
.Text(': '))
141 term
.append(nodes
.literal('', member
.type.doc_type()))
143 term
.append(nodes
.Text(' (optional)'))
144 if member
.ifcond
.is_present():
145 term
.extend(self
._nodes
_for
_ifcond
(member
.ifcond
))
148 def _nodes_for_variant_when(self
, variants
, variant
):
149 """Return list of Text, literal nodes for variant 'when' clause
151 Return a list of doctree nodes which give text like
152 'when tagname is variant (If: ...)' suitable for use in
153 the 'variants' part of a definition list.
155 term
= [nodes
.Text(' when '),
156 nodes
.literal('', variants
.tag_member
.name
),
158 nodes
.literal('', '"%s"' % variant
.name
)]
159 if variant
.ifcond
.is_present():
160 term
.extend(self
._nodes
_for
_ifcond
(variant
.ifcond
))
163 def _nodes_for_members(self
, doc
, what
, base
=None, variants
=None):
164 """Return list of doctree nodes for the table of members"""
165 dlnode
= nodes
.definition_list()
166 for section
in doc
.args
.values():
167 term
= self
._nodes
_for
_one
_member
(section
.member
)
168 # TODO drop fallbacks when undocumented members are outlawed
172 defn
= [nodes
.Text('Not documented')]
174 dlnode
+= self
._make
_dlitem
(term
, defn
)
177 dlnode
+= self
._make
_dlitem
([nodes
.Text('The members of '),
178 nodes
.literal('', base
.doc_type())],
182 for v
in variants
.variants
:
183 if v
.type.is_implicit():
184 assert not v
.type.base
and not v
.type.variants
185 for m
in v
.type.local_members
:
186 term
= self
._nodes
_for
_one
_member
(m
)
187 term
.extend(self
._nodes
_for
_variant
_when
(variants
, v
))
188 dlnode
+= self
._make
_dlitem
(term
, None)
190 term
= [nodes
.Text('The members of '),
191 nodes
.literal('', v
.type.doc_type())]
192 term
.extend(self
._nodes
_for
_variant
_when
(variants
, v
))
193 dlnode
+= self
._make
_dlitem
(term
, None)
195 if not dlnode
.children
:
198 section
= self
._make
_section
(what
)
202 def _nodes_for_enum_values(self
, doc
):
203 """Return list of doctree nodes for the table of enum values"""
205 dlnode
= nodes
.definition_list()
206 for section
in doc
.args
.values():
207 termtext
= [nodes
.literal('', section
.member
.name
)]
208 if section
.member
.ifcond
.is_present():
209 termtext
.extend(self
._nodes
_for
_ifcond
(section
.member
.ifcond
))
210 # TODO drop fallbacks when undocumented members are outlawed
214 defn
= [nodes
.Text('Not documented')]
216 dlnode
+= self
._make
_dlitem
(termtext
, defn
)
222 section
= self
._make
_section
('Values')
226 def _nodes_for_arguments(self
, doc
, boxed_arg_type
):
227 """Return list of doctree nodes for the arguments section"""
230 section
= self
._make
_section
('Arguments')
231 dlnode
= nodes
.definition_list()
232 dlnode
+= self
._make
_dlitem
(
233 [nodes
.Text('The members of '),
234 nodes
.literal('', boxed_arg_type
.name
)],
239 return self
._nodes
_for
_members
(doc
, 'Arguments')
241 def _nodes_for_features(self
, doc
):
242 """Return list of doctree nodes for the table of features"""
244 dlnode
= nodes
.definition_list()
245 for section
in doc
.features
.values():
246 dlnode
+= self
._make
_dlitem
([nodes
.literal('', section
.name
)],
253 section
= self
._make
_section
('Features')
257 def _nodes_for_example(self
, exampletext
):
258 """Return list of doctree nodes for a code example snippet"""
259 return [nodes
.literal_block(exampletext
, exampletext
)]
261 def _nodes_for_sections(self
, doc
):
262 """Return list of doctree nodes for additional sections"""
264 for section
in doc
.sections
:
265 if section
.name
and section
.name
== 'TODO':
266 # Hide TODO: sections
268 snode
= self
._make
_section
(section
.name
)
269 if section
.name
and section
.name
.startswith('Example'):
270 snode
+= self
._nodes
_for
_example
(section
.text
)
272 self
._parse
_text
_into
_node
(section
.text
, snode
)
273 nodelist
.append(snode
)
276 def _nodes_for_if_section(self
, ifcond
):
277 """Return list of doctree nodes for the "If" section"""
279 if ifcond
.is_present():
280 snode
= self
._make
_section
('If')
281 snode
+= nodes
.paragraph(
282 '', '', *self
._nodes
_for
_ifcond
(ifcond
, with_if
=False)
284 nodelist
.append(snode
)
287 def _add_doc(self
, typ
, sections
):
288 """Add documentation for a command/object/enum...
290 We assume we're documenting the thing defined in self._cur_doc.
291 typ is the type of thing being added ("Command", "Object", etc)
293 sections is a list of nodes for sections to add to the definition.
297 snode
= nodes
.section(ids
=[self
._sphinx
_directive
.new_serialno()])
298 snode
+= nodes
.title('', '', *[nodes
.literal(doc
.symbol
, doc
.symbol
),
299 nodes
.Text(' (' + typ
+ ')')])
300 self
._parse
_text
_into
_node
(doc
.body
.text
, snode
)
304 self
._add
_node
_to
_current
_heading
(snode
)
306 def visit_enum_type(self
, name
, info
, ifcond
, features
, members
, prefix
):
308 self
._add
_doc
('Enum',
309 self
._nodes
_for
_enum
_values
(doc
)
310 + self
._nodes
_for
_features
(doc
)
311 + self
._nodes
_for
_sections
(doc
)
312 + self
._nodes
_for
_if
_section
(ifcond
))
314 def visit_object_type(self
, name
, info
, ifcond
, features
,
315 base
, members
, variants
):
317 if base
and base
.is_implicit():
319 self
._add
_doc
('Object',
320 self
._nodes
_for
_members
(doc
, 'Members', base
, variants
)
321 + self
._nodes
_for
_features
(doc
)
322 + self
._nodes
_for
_sections
(doc
)
323 + self
._nodes
_for
_if
_section
(ifcond
))
325 def visit_alternate_type(self
, name
, info
, ifcond
, features
, variants
):
327 self
._add
_doc
('Alternate',
328 self
._nodes
_for
_members
(doc
, 'Members')
329 + self
._nodes
_for
_features
(doc
)
330 + self
._nodes
_for
_sections
(doc
)
331 + self
._nodes
_for
_if
_section
(ifcond
))
333 def visit_command(self
, name
, info
, ifcond
, features
, arg_type
,
334 ret_type
, gen
, success_response
, boxed
, allow_oob
,
335 allow_preconfig
, coroutine
):
337 self
._add
_doc
('Command',
338 self
._nodes
_for
_arguments
(doc
,
339 arg_type
if boxed
else None)
340 + self
._nodes
_for
_features
(doc
)
341 + self
._nodes
_for
_sections
(doc
)
342 + self
._nodes
_for
_if
_section
(ifcond
))
344 def visit_event(self
, name
, info
, ifcond
, features
, arg_type
, boxed
):
346 self
._add
_doc
('Event',
347 self
._nodes
_for
_arguments
(doc
,
348 arg_type
if boxed
else None)
349 + self
._nodes
_for
_features
(doc
)
350 + self
._nodes
_for
_sections
(doc
)
351 + self
._nodes
_for
_if
_section
(ifcond
))
353 def symbol(self
, doc
, entity
):
354 """Add documentation for one symbol to the document tree
356 This is the main entry point which causes us to add documentation
357 nodes for a symbol (which could be a 'command', 'object', 'event',
358 etc). We do this by calling 'visit' on the schema entity, which
359 will then call back into one of our visit_* methods, depending
360 on what kind of thing this symbol is.
366 def _start_new_heading(self
, heading
, level
):
367 """Start a new heading at the specified heading level
369 Create a new section whose title is 'heading' and which is placed
370 in the docutils node tree as a child of the most recent level-1
371 heading. Subsequent document sections (commands, freeform doc chunks,
372 etc) will be placed as children of this new heading section.
374 if len(self
._active
_headings
) < level
:
375 raise QAPISemError(self
._cur
_doc
.info
,
376 'Level %d subheading found outside a '
378 % (level
, level
- 1))
379 snode
= self
._make
_section
(heading
)
380 self
._active
_headings
[level
- 1] += snode
381 self
._active
_headings
= self
._active
_headings
[:level
]
382 self
._active
_headings
.append(snode
)
384 def _add_node_to_current_heading(self
, node
):
385 """Add the node to whatever the current active heading is"""
386 self
._active
_headings
[-1] += node
388 def freeform(self
, doc
):
389 """Add a piece of 'freeform' documentation to the document tree
391 A 'freeform' document chunk doesn't relate to any particular
392 symbol (for instance, it could be an introduction).
394 If the freeform document starts with a line of the form
395 '= Heading text', this is a section or subsection heading, with
396 the heading level indicated by the number of '=' signs.
399 # QAPIDoc documentation says free-form documentation blocks
400 # must have only a body section, nothing else.
401 assert not doc
.sections
403 assert not doc
.features
407 if re
.match(r
'=+ ', text
):
408 # Section/subsection heading (if present, will always be
409 # the first line of the block)
410 (heading
, _
, text
) = text
.partition('\n')
411 (leader
, _
, heading
) = heading
.partition(' ')
412 self
._start
_new
_heading
(heading
, len(leader
))
416 node
= self
._make
_section
(None)
417 self
._parse
_text
_into
_node
(text
, node
)
418 self
._add
_node
_to
_current
_heading
(node
)
421 def _parse_text_into_node(self
, doctext
, node
):
422 """Parse a chunk of QAPI-doc-format text into the node
424 The doc comment can contain most inline rST markup, including
425 bulleted and enumerated lists.
426 As an extra permitted piece of markup, @var will be turned
430 # Handle the "@var means ``var`` case
431 doctext
= re
.sub(r
'@([\w-]+)', r
'``\1``', doctext
)
434 for line
in doctext
.splitlines():
435 # The reported line number will always be that of the start line
436 # of the doc comment, rather than the actual location of the error.
437 # Being more precise would require overhaul of the QAPIDoc class
438 # to track lines more exactly within all the sub-parts of the doc
439 # comment, as well as counting lines here.
440 rstlist
.append(line
, self
._cur
_doc
.info
.fname
,
441 self
._cur
_doc
.info
.line
)
442 # Append a blank line -- in some cases rST syntax errors get
443 # attributed to the line after one with actual text, and if there
444 # isn't anything in the ViewList corresponding to that then Sphinx
445 # 1.6's AutodocReporter will then misidentify the source/line location
446 # in the error message (usually attributing it to the top-level
447 # .rst file rather than the offending .json file). The extra blank
448 # line won't affect the rendered output.
449 rstlist
.append("", self
._cur
_doc
.info
.fname
, self
._cur
_doc
.info
.line
)
450 self
._sphinx
_directive
.do_parse(rstlist
, node
)
452 def get_document_nodes(self
):
453 """Return the list of docutils nodes which make up the document"""
454 return self
._top
_node
.children
457 class QAPISchemaGenDepVisitor(QAPISchemaVisitor
):
458 """A QAPI schema visitor which adds Sphinx dependencies each module
460 This class calls the Sphinx note_dependency() function to tell Sphinx
461 that the generated documentation output depends on the input
462 schema file associated with each module in the QAPI input.
464 def __init__(self
, env
, qapidir
):
466 self
._qapidir
= qapidir
468 def visit_module(self
, name
):
469 if name
!= "./builtin":
470 qapifile
= self
._qapidir
+ '/' + name
471 self
._env
.note_dependency(os
.path
.abspath(qapifile
))
472 super().visit_module(name
)
475 class QAPIDocDirective(Directive
):
476 """Extract documentation from the specified QAPI .json file"""
477 required_argument
= 1
478 optional_arguments
= 1
480 'qapifile': directives
.unchanged_required
484 def new_serialno(self
):
485 """Return a unique new ID string suitable for use as a node's ID"""
486 env
= self
.state
.document
.settings
.env
487 return 'qapidoc-%d' % env
.new_serialno('qapidoc')
490 env
= self
.state
.document
.settings
.env
491 qapifile
= env
.config
.qapidoc_srctree
+ '/' + self
.arguments
[0]
492 qapidir
= os
.path
.dirname(qapifile
)
495 schema
= QAPISchema(qapifile
)
497 # First tell Sphinx about all the schema files that the
498 # output documentation depends on (including 'qapifile' itself)
499 schema
.visit(QAPISchemaGenDepVisitor(env
, qapidir
))
501 vis
= QAPISchemaGenRSTVisitor(self
)
502 vis
.visit_begin(schema
)
503 for doc
in schema
.docs
:
505 vis
.symbol(doc
, schema
.lookup_entity(doc
.symbol
))
508 return vis
.get_document_nodes()
509 except QAPIError
as err
:
510 # Launder QAPI parse errors into Sphinx extension errors
511 # so they are displayed nicely to the user
512 raise ExtensionError(str(err
)) from err
514 def do_parse(self
, rstlist
, node
):
515 """Parse rST source lines and add them to the specified node
517 Take the list of rST source lines rstlist, parse them as
518 rST, and add the resulting docutils nodes as children of node.
519 The nodes are parsed in a way that allows them to include
520 subheadings (titles) without confusing the rendering of
523 # This is from kerneldoc.py -- it works around an API change in
524 # Sphinx between 1.6 and 1.7. Unlike kerneldoc.py, we use
525 # sphinx.util.nodes.nested_parse_with_titles() rather than the
526 # plain self.state.nested_parse(), and so we can drop the saving
527 # of title_styles and section_level that kerneldoc.py does,
528 # because nested_parse_with_titles() does that for us.
530 with
switch_source_input(self
.state
, rstlist
):
531 nested_parse_with_titles(self
.state
, rstlist
, node
)
533 save
= self
.state
.memo
.reporter
534 self
.state
.memo
.reporter
= AutodocReporter(
535 rstlist
, self
.state
.memo
.reporter
)
537 nested_parse_with_titles(self
.state
, rstlist
, node
)
539 self
.state
.memo
.reporter
= save
543 """ Register qapi-doc directive with Sphinx"""
544 app
.add_config_value('qapidoc_srctree', None, 'env')
545 app
.add_directive('qapi-doc', QAPIDocDirective
)
549 parallel_read_safe
=True,
550 parallel_write_safe
=True