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.name
== 'q_empty':
185 assert not v
.type.is_implicit()
186 term
= [nodes
.Text('The members of '),
187 nodes
.literal('', v
.type.doc_type())]
188 term
.extend(self
._nodes
_for
_variant
_when
(variants
, v
))
189 dlnode
+= self
._make
_dlitem
(term
, None)
191 if not dlnode
.children
:
194 section
= self
._make
_section
(what
)
198 def _nodes_for_enum_values(self
, doc
):
199 """Return list of doctree nodes for the table of enum values"""
201 dlnode
= nodes
.definition_list()
202 for section
in doc
.args
.values():
203 termtext
= [nodes
.literal('', section
.member
.name
)]
204 if section
.member
.ifcond
.is_present():
205 termtext
.extend(self
._nodes
_for
_ifcond
(section
.member
.ifcond
))
206 # TODO drop fallbacks when undocumented members are outlawed
210 defn
= [nodes
.Text('Not documented')]
212 dlnode
+= self
._make
_dlitem
(termtext
, defn
)
218 section
= self
._make
_section
('Values')
222 def _nodes_for_arguments(self
, doc
, boxed_arg_type
):
223 """Return list of doctree nodes for the arguments section"""
226 section
= self
._make
_section
('Arguments')
227 dlnode
= nodes
.definition_list()
228 dlnode
+= self
._make
_dlitem
(
229 [nodes
.Text('The members of '),
230 nodes
.literal('', boxed_arg_type
.name
)],
235 return self
._nodes
_for
_members
(doc
, 'Arguments')
237 def _nodes_for_features(self
, doc
):
238 """Return list of doctree nodes for the table of features"""
240 dlnode
= nodes
.definition_list()
241 for section
in doc
.features
.values():
242 dlnode
+= self
._make
_dlitem
(
243 [nodes
.literal('', section
.member
.name
)], section
.text
)
249 section
= self
._make
_section
('Features')
253 def _nodes_for_example(self
, exampletext
):
254 """Return list of doctree nodes for a code example snippet"""
255 return [nodes
.literal_block(exampletext
, exampletext
)]
257 def _nodes_for_sections(self
, doc
):
258 """Return list of doctree nodes for additional sections"""
260 for section
in doc
.sections
:
261 if section
.tag
and section
.tag
== 'TODO':
262 # Hide TODO: sections
264 snode
= self
._make
_section
(section
.tag
)
265 if section
.tag
and section
.tag
.startswith('Example'):
266 snode
+= self
._nodes
_for
_example
(section
.text
)
268 self
._parse
_text
_into
_node
(section
.text
, snode
)
269 nodelist
.append(snode
)
272 def _nodes_for_if_section(self
, ifcond
):
273 """Return list of doctree nodes for the "If" section"""
275 if ifcond
.is_present():
276 snode
= self
._make
_section
('If')
277 snode
+= nodes
.paragraph(
278 '', '', *self
._nodes
_for
_ifcond
(ifcond
, with_if
=False)
280 nodelist
.append(snode
)
283 def _add_doc(self
, typ
, sections
):
284 """Add documentation for a command/object/enum...
286 We assume we're documenting the thing defined in self._cur_doc.
287 typ is the type of thing being added ("Command", "Object", etc)
289 sections is a list of nodes for sections to add to the definition.
293 snode
= nodes
.section(ids
=[self
._sphinx
_directive
.new_serialno()])
294 snode
+= nodes
.title('', '', *[nodes
.literal(doc
.symbol
, doc
.symbol
),
295 nodes
.Text(' (' + typ
+ ')')])
296 self
._parse
_text
_into
_node
(doc
.body
.text
, snode
)
300 self
._add
_node
_to
_current
_heading
(snode
)
302 def visit_enum_type(self
, name
, info
, ifcond
, features
, members
, prefix
):
304 self
._add
_doc
('Enum',
305 self
._nodes
_for
_enum
_values
(doc
)
306 + self
._nodes
_for
_features
(doc
)
307 + self
._nodes
_for
_sections
(doc
)
308 + self
._nodes
_for
_if
_section
(ifcond
))
310 def visit_object_type(self
, name
, info
, ifcond
, features
,
311 base
, members
, variants
):
313 if base
and base
.is_implicit():
315 self
._add
_doc
('Object',
316 self
._nodes
_for
_members
(doc
, 'Members', base
, variants
)
317 + self
._nodes
_for
_features
(doc
)
318 + self
._nodes
_for
_sections
(doc
)
319 + self
._nodes
_for
_if
_section
(ifcond
))
321 def visit_alternate_type(self
, name
, info
, ifcond
, features
, variants
):
323 self
._add
_doc
('Alternate',
324 self
._nodes
_for
_members
(doc
, 'Members')
325 + self
._nodes
_for
_features
(doc
)
326 + self
._nodes
_for
_sections
(doc
)
327 + self
._nodes
_for
_if
_section
(ifcond
))
329 def visit_command(self
, name
, info
, ifcond
, features
, arg_type
,
330 ret_type
, gen
, success_response
, boxed
, allow_oob
,
331 allow_preconfig
, coroutine
):
333 self
._add
_doc
('Command',
334 self
._nodes
_for
_arguments
(doc
,
335 arg_type
if boxed
else None)
336 + self
._nodes
_for
_features
(doc
)
337 + self
._nodes
_for
_sections
(doc
)
338 + self
._nodes
_for
_if
_section
(ifcond
))
340 def visit_event(self
, name
, info
, ifcond
, features
, arg_type
, boxed
):
342 self
._add
_doc
('Event',
343 self
._nodes
_for
_arguments
(doc
,
344 arg_type
if boxed
else None)
345 + self
._nodes
_for
_features
(doc
)
346 + self
._nodes
_for
_sections
(doc
)
347 + self
._nodes
_for
_if
_section
(ifcond
))
349 def symbol(self
, doc
, entity
):
350 """Add documentation for one symbol to the document tree
352 This is the main entry point which causes us to add documentation
353 nodes for a symbol (which could be a 'command', 'object', 'event',
354 etc). We do this by calling 'visit' on the schema entity, which
355 will then call back into one of our visit_* methods, depending
356 on what kind of thing this symbol is.
362 def _start_new_heading(self
, heading
, level
):
363 """Start a new heading at the specified heading level
365 Create a new section whose title is 'heading' and which is placed
366 in the docutils node tree as a child of the most recent level-1
367 heading. Subsequent document sections (commands, freeform doc chunks,
368 etc) will be placed as children of this new heading section.
370 if len(self
._active
_headings
) < level
:
371 raise QAPISemError(self
._cur
_doc
.info
,
372 'Level %d subheading found outside a '
374 % (level
, level
- 1))
375 snode
= self
._make
_section
(heading
)
376 self
._active
_headings
[level
- 1] += snode
377 self
._active
_headings
= self
._active
_headings
[:level
]
378 self
._active
_headings
.append(snode
)
380 def _add_node_to_current_heading(self
, node
):
381 """Add the node to whatever the current active heading is"""
382 self
._active
_headings
[-1] += node
384 def freeform(self
, doc
):
385 """Add a piece of 'freeform' documentation to the document tree
387 A 'freeform' document chunk doesn't relate to any particular
388 symbol (for instance, it could be an introduction).
390 If the freeform document starts with a line of the form
391 '= Heading text', this is a section or subsection heading, with
392 the heading level indicated by the number of '=' signs.
395 # QAPIDoc documentation says free-form documentation blocks
396 # must have only a body section, nothing else.
397 assert not doc
.sections
399 assert not doc
.features
403 if re
.match(r
'=+ ', text
):
404 # Section/subsection heading (if present, will always be
405 # the first line of the block)
406 (heading
, _
, text
) = text
.partition('\n')
407 (leader
, _
, heading
) = heading
.partition(' ')
408 self
._start
_new
_heading
(heading
, len(leader
))
412 node
= self
._make
_section
(None)
413 self
._parse
_text
_into
_node
(text
, node
)
414 self
._add
_node
_to
_current
_heading
(node
)
417 def _parse_text_into_node(self
, doctext
, node
):
418 """Parse a chunk of QAPI-doc-format text into the node
420 The doc comment can contain most inline rST markup, including
421 bulleted and enumerated lists.
422 As an extra permitted piece of markup, @var will be turned
426 # Handle the "@var means ``var`` case
427 doctext
= re
.sub(r
'@([\w-]+)', r
'``\1``', doctext
)
430 for line
in doctext
.splitlines():
431 # The reported line number will always be that of the start line
432 # of the doc comment, rather than the actual location of the error.
433 # Being more precise would require overhaul of the QAPIDoc class
434 # to track lines more exactly within all the sub-parts of the doc
435 # comment, as well as counting lines here.
436 rstlist
.append(line
, self
._cur
_doc
.info
.fname
,
437 self
._cur
_doc
.info
.line
)
438 # Append a blank line -- in some cases rST syntax errors get
439 # attributed to the line after one with actual text, and if there
440 # isn't anything in the ViewList corresponding to that then Sphinx
441 # 1.6's AutodocReporter will then misidentify the source/line location
442 # in the error message (usually attributing it to the top-level
443 # .rst file rather than the offending .json file). The extra blank
444 # line won't affect the rendered output.
445 rstlist
.append("", self
._cur
_doc
.info
.fname
, self
._cur
_doc
.info
.line
)
446 self
._sphinx
_directive
.do_parse(rstlist
, node
)
448 def get_document_nodes(self
):
449 """Return the list of docutils nodes which make up the document"""
450 return self
._top
_node
.children
453 class QAPISchemaGenDepVisitor(QAPISchemaVisitor
):
454 """A QAPI schema visitor which adds Sphinx dependencies each module
456 This class calls the Sphinx note_dependency() function to tell Sphinx
457 that the generated documentation output depends on the input
458 schema file associated with each module in the QAPI input.
460 def __init__(self
, env
, qapidir
):
462 self
._qapidir
= qapidir
464 def visit_module(self
, name
):
465 if name
!= "./builtin":
466 qapifile
= self
._qapidir
+ '/' + name
467 self
._env
.note_dependency(os
.path
.abspath(qapifile
))
468 super().visit_module(name
)
471 class QAPIDocDirective(Directive
):
472 """Extract documentation from the specified QAPI .json file"""
473 required_argument
= 1
474 optional_arguments
= 1
476 'qapifile': directives
.unchanged_required
480 def new_serialno(self
):
481 """Return a unique new ID string suitable for use as a node's ID"""
482 env
= self
.state
.document
.settings
.env
483 return 'qapidoc-%d' % env
.new_serialno('qapidoc')
486 env
= self
.state
.document
.settings
.env
487 qapifile
= env
.config
.qapidoc_srctree
+ '/' + self
.arguments
[0]
488 qapidir
= os
.path
.dirname(qapifile
)
491 schema
= QAPISchema(qapifile
)
493 # First tell Sphinx about all the schema files that the
494 # output documentation depends on (including 'qapifile' itself)
495 schema
.visit(QAPISchemaGenDepVisitor(env
, qapidir
))
497 vis
= QAPISchemaGenRSTVisitor(self
)
498 vis
.visit_begin(schema
)
499 for doc
in schema
.docs
:
501 vis
.symbol(doc
, schema
.lookup_entity(doc
.symbol
))
504 return vis
.get_document_nodes()
505 except QAPIError
as err
:
506 # Launder QAPI parse errors into Sphinx extension errors
507 # so they are displayed nicely to the user
508 raise ExtensionError(str(err
)) from err
510 def do_parse(self
, rstlist
, node
):
511 """Parse rST source lines and add them to the specified node
513 Take the list of rST source lines rstlist, parse them as
514 rST, and add the resulting docutils nodes as children of node.
515 The nodes are parsed in a way that allows them to include
516 subheadings (titles) without confusing the rendering of
519 # This is from kerneldoc.py -- it works around an API change in
520 # Sphinx between 1.6 and 1.7. Unlike kerneldoc.py, we use
521 # sphinx.util.nodes.nested_parse_with_titles() rather than the
522 # plain self.state.nested_parse(), and so we can drop the saving
523 # of title_styles and section_level that kerneldoc.py does,
524 # because nested_parse_with_titles() does that for us.
526 with
switch_source_input(self
.state
, rstlist
):
527 nested_parse_with_titles(self
.state
, rstlist
, node
)
529 save
= self
.state
.memo
.reporter
530 self
.state
.memo
.reporter
= AutodocReporter(
531 rstlist
, self
.state
.memo
.reporter
)
533 nested_parse_with_titles(self
.state
, rstlist
, node
)
535 self
.state
.memo
.reporter
= save
539 """ Register qapi-doc directive with Sphinx"""
540 app
.add_config_value('qapidoc_srctree', None, 'env')
541 app
.add_directive('qapi-doc', QAPIDocDirective
)
545 parallel_read_safe
=True,
546 parallel_write_safe
=True