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: cond1, cond2, cond3)', where
116 the conditions are in literal-text and the commas are not.
117 If with_if is False, we don't return the "(If: " and ")".
119 condlist
= intersperse([nodes
.literal('', c
) for c
in ifcond
],
124 nodelist
= [nodes
.Text(' ('), nodes
.strong('', 'If: ')]
125 nodelist
.extend(condlist
)
126 nodelist
.append(nodes
.Text(')'))
129 def _nodes_for_one_member(self
, member
):
130 """Return list of Text, literal nodes for this member
132 Return a list of doctree nodes which give text like
133 'name: type (optional) (If: ...)' suitable for use as the
134 'term' part of a definition list item.
136 term
= [nodes
.literal('', member
.name
)]
137 if member
.type.doc_type():
138 term
.append(nodes
.Text(': '))
139 term
.append(nodes
.literal('', member
.type.doc_type()))
141 term
.append(nodes
.Text(' (optional)'))
143 term
.extend(self
._nodes
_for
_ifcond
(member
.ifcond
))
146 def _nodes_for_variant_when(self
, variants
, variant
):
147 """Return list of Text, literal nodes for variant 'when' clause
149 Return a list of doctree nodes which give text like
150 'when tagname is variant (If: ...)' suitable for use in
151 the 'variants' part of a definition list.
153 term
= [nodes
.Text(' when '),
154 nodes
.literal('', variants
.tag_member
.name
),
156 nodes
.literal('', '"%s"' % variant
.name
)]
158 term
.extend(self
._nodes
_for
_ifcond
(variant
.ifcond
))
161 def _nodes_for_members(self
, doc
, what
, base
=None, variants
=None):
162 """Return list of doctree nodes for the table of members"""
163 dlnode
= nodes
.definition_list()
164 for section
in doc
.args
.values():
165 term
= self
._nodes
_for
_one
_member
(section
.member
)
166 # TODO drop fallbacks when undocumented members are outlawed
169 elif (variants
and variants
.tag_member
== section
.member
170 and not section
.member
.type.doc_type()):
171 values
= section
.member
.type.member_names()
172 defn
= [nodes
.Text('One of ')]
173 defn
.extend(intersperse([nodes
.literal('', v
) for v
in values
],
176 defn
= [nodes
.Text('Not documented')]
178 dlnode
+= self
._make
_dlitem
(term
, defn
)
181 dlnode
+= self
._make
_dlitem
([nodes
.Text('The members of '),
182 nodes
.literal('', base
.doc_type())],
186 for v
in variants
.variants
:
187 if v
.type.is_implicit():
188 assert not v
.type.base
and not v
.type.variants
189 for m
in v
.type.local_members
:
190 term
= self
._nodes
_for
_one
_member
(m
)
191 term
.extend(self
._nodes
_for
_variant
_when
(variants
, v
))
192 dlnode
+= self
._make
_dlitem
(term
, None)
194 term
= [nodes
.Text('The members of '),
195 nodes
.literal('', v
.type.doc_type())]
196 term
.extend(self
._nodes
_for
_variant
_when
(variants
, v
))
197 dlnode
+= self
._make
_dlitem
(term
, None)
199 if not dlnode
.children
:
202 section
= self
._make
_section
(what
)
206 def _nodes_for_enum_values(self
, doc
):
207 """Return list of doctree nodes for the table of enum values"""
209 dlnode
= nodes
.definition_list()
210 for section
in doc
.args
.values():
211 termtext
= [nodes
.literal('', section
.member
.name
)]
212 if section
.member
.ifcond
:
213 termtext
.extend(self
._nodes
_for
_ifcond
(section
.member
.ifcond
))
214 # TODO drop fallbacks when undocumented members are outlawed
218 defn
= [nodes
.Text('Not documented')]
220 dlnode
+= self
._make
_dlitem
(termtext
, defn
)
226 section
= self
._make
_section
('Values')
230 def _nodes_for_arguments(self
, doc
, boxed_arg_type
):
231 """Return list of doctree nodes for the arguments section"""
234 section
= self
._make
_section
('Arguments')
235 dlnode
= nodes
.definition_list()
236 dlnode
+= self
._make
_dlitem
(
237 [nodes
.Text('The members of '),
238 nodes
.literal('', boxed_arg_type
.name
)],
243 return self
._nodes
_for
_members
(doc
, 'Arguments')
245 def _nodes_for_features(self
, doc
):
246 """Return list of doctree nodes for the table of features"""
248 dlnode
= nodes
.definition_list()
249 for section
in doc
.features
.values():
250 dlnode
+= self
._make
_dlitem
([nodes
.literal('', section
.name
)],
257 section
= self
._make
_section
('Features')
261 def _nodes_for_example(self
, exampletext
):
262 """Return list of doctree nodes for a code example snippet"""
263 return [nodes
.literal_block(exampletext
, exampletext
)]
265 def _nodes_for_sections(self
, doc
):
266 """Return list of doctree nodes for additional sections"""
268 for section
in doc
.sections
:
269 snode
= self
._make
_section
(section
.name
)
270 if section
.name
and section
.name
.startswith('Example'):
271 snode
+= self
._nodes
_for
_example
(section
.text
)
273 self
._parse
_text
_into
_node
(section
.text
, snode
)
274 nodelist
.append(snode
)
277 def _nodes_for_if_section(self
, ifcond
):
278 """Return list of doctree nodes for the "If" section"""
281 snode
= self
._make
_section
('If')
282 snode
+= nodes
.paragraph(
283 '', '', *self
._nodes
_for
_ifcond
(ifcond
, with_if
=False)
285 nodelist
.append(snode
)
288 def _add_doc(self
, typ
, sections
):
289 """Add documentation for a command/object/enum...
291 We assume we're documenting the thing defined in self._cur_doc.
292 typ is the type of thing being added ("Command", "Object", etc)
294 sections is a list of nodes for sections to add to the definition.
298 snode
= nodes
.section(ids
=[self
._sphinx
_directive
.new_serialno()])
299 snode
+= nodes
.title('', '', *[nodes
.literal(doc
.symbol
, doc
.symbol
),
300 nodes
.Text(' (' + typ
+ ')')])
301 self
._parse
_text
_into
_node
(doc
.body
.text
, snode
)
305 self
._add
_node
_to
_current
_heading
(snode
)
307 def visit_enum_type(self
, name
, info
, ifcond
, features
, members
, prefix
):
309 self
._add
_doc
('Enum',
310 self
._nodes
_for
_enum
_values
(doc
)
311 + self
._nodes
_for
_features
(doc
)
312 + self
._nodes
_for
_sections
(doc
)
313 + self
._nodes
_for
_if
_section
(ifcond
))
315 def visit_object_type(self
, name
, info
, ifcond
, features
,
316 base
, members
, variants
):
318 if base
and base
.is_implicit():
320 self
._add
_doc
('Object',
321 self
._nodes
_for
_members
(doc
, 'Members', base
, variants
)
322 + self
._nodes
_for
_features
(doc
)
323 + self
._nodes
_for
_sections
(doc
)
324 + self
._nodes
_for
_if
_section
(ifcond
))
326 def visit_alternate_type(self
, name
, info
, ifcond
, features
, variants
):
328 self
._add
_doc
('Alternate',
329 self
._nodes
_for
_members
(doc
, 'Members')
330 + self
._nodes
_for
_features
(doc
)
331 + self
._nodes
_for
_sections
(doc
)
332 + self
._nodes
_for
_if
_section
(ifcond
))
334 def visit_command(self
, name
, info
, ifcond
, features
, arg_type
,
335 ret_type
, gen
, success_response
, boxed
, allow_oob
,
336 allow_preconfig
, coroutine
):
338 self
._add
_doc
('Command',
339 self
._nodes
_for
_arguments
(doc
,
340 arg_type
if boxed
else None)
341 + self
._nodes
_for
_features
(doc
)
342 + self
._nodes
_for
_sections
(doc
)
343 + self
._nodes
_for
_if
_section
(ifcond
))
345 def visit_event(self
, name
, info
, ifcond
, features
, arg_type
, boxed
):
347 self
._add
_doc
('Event',
348 self
._nodes
_for
_arguments
(doc
,
349 arg_type
if boxed
else None)
350 + self
._nodes
_for
_features
(doc
)
351 + self
._nodes
_for
_sections
(doc
)
352 + self
._nodes
_for
_if
_section
(ifcond
))
354 def symbol(self
, doc
, entity
):
355 """Add documentation for one symbol to the document tree
357 This is the main entry point which causes us to add documentation
358 nodes for a symbol (which could be a 'command', 'object', 'event',
359 etc). We do this by calling 'visit' on the schema entity, which
360 will then call back into one of our visit_* methods, depending
361 on what kind of thing this symbol is.
367 def _start_new_heading(self
, heading
, level
):
368 """Start a new heading at the specified heading level
370 Create a new section whose title is 'heading' and which is placed
371 in the docutils node tree as a child of the most recent level-1
372 heading. Subsequent document sections (commands, freeform doc chunks,
373 etc) will be placed as children of this new heading section.
375 if len(self
._active
_headings
) < level
:
376 raise QAPISemError(self
._cur
_doc
.info
,
377 'Level %d subheading found outside a '
379 % (level
, level
- 1))
380 snode
= self
._make
_section
(heading
)
381 self
._active
_headings
[level
- 1] += snode
382 self
._active
_headings
= self
._active
_headings
[:level
]
383 self
._active
_headings
.append(snode
)
385 def _add_node_to_current_heading(self
, node
):
386 """Add the node to whatever the current active heading is"""
387 self
._active
_headings
[-1] += node
389 def freeform(self
, doc
):
390 """Add a piece of 'freeform' documentation to the document tree
392 A 'freeform' document chunk doesn't relate to any particular
393 symbol (for instance, it could be an introduction).
395 If the freeform document starts with a line of the form
396 '= Heading text', this is a section or subsection heading, with
397 the heading level indicated by the number of '=' signs.
400 # QAPIDoc documentation says free-form documentation blocks
401 # must have only a body section, nothing else.
402 assert not doc
.sections
404 assert not doc
.features
408 if re
.match(r
'=+ ', text
):
409 # Section/subsection heading (if present, will always be
410 # the first line of the block)
411 (heading
, _
, text
) = text
.partition('\n')
412 (leader
, _
, heading
) = heading
.partition(' ')
413 self
._start
_new
_heading
(heading
, len(leader
))
417 node
= self
._make
_section
(None)
418 self
._parse
_text
_into
_node
(text
, node
)
419 self
._add
_node
_to
_current
_heading
(node
)
422 def _parse_text_into_node(self
, doctext
, node
):
423 """Parse a chunk of QAPI-doc-format text into the node
425 The doc comment can contain most inline rST markup, including
426 bulleted and enumerated lists.
427 As an extra permitted piece of markup, @var will be turned
431 # Handle the "@var means ``var`` case
432 doctext
= re
.sub(r
'@([\w-]+)', r
'``\1``', doctext
)
435 for line
in doctext
.splitlines():
436 # The reported line number will always be that of the start line
437 # of the doc comment, rather than the actual location of the error.
438 # Being more precise would require overhaul of the QAPIDoc class
439 # to track lines more exactly within all the sub-parts of the doc
440 # comment, as well as counting lines here.
441 rstlist
.append(line
, self
._cur
_doc
.info
.fname
,
442 self
._cur
_doc
.info
.line
)
443 # Append a blank line -- in some cases rST syntax errors get
444 # attributed to the line after one with actual text, and if there
445 # isn't anything in the ViewList corresponding to that then Sphinx
446 # 1.6's AutodocReporter will then misidentify the source/line location
447 # in the error message (usually attributing it to the top-level
448 # .rst file rather than the offending .json file). The extra blank
449 # line won't affect the rendered output.
450 rstlist
.append("", self
._cur
_doc
.info
.fname
, self
._cur
_doc
.info
.line
)
451 self
._sphinx
_directive
.do_parse(rstlist
, node
)
453 def get_document_nodes(self
):
454 """Return the list of docutils nodes which make up the document"""
455 return self
._top
_node
.children
458 class QAPISchemaGenDepVisitor(QAPISchemaVisitor
):
459 """A QAPI schema visitor which adds Sphinx dependencies each module
461 This class calls the Sphinx note_dependency() function to tell Sphinx
462 that the generated documentation output depends on the input
463 schema file associated with each module in the QAPI input.
465 def __init__(self
, env
, qapidir
):
467 self
._qapidir
= qapidir
469 def visit_module(self
, name
):
470 if name
!= "./builtin":
471 qapifile
= self
._qapidir
+ '/' + name
472 self
._env
.note_dependency(os
.path
.abspath(qapifile
))
473 super().visit_module(name
)
476 class QAPIDocDirective(Directive
):
477 """Extract documentation from the specified QAPI .json file"""
478 required_argument
= 1
479 optional_arguments
= 1
481 'qapifile': directives
.unchanged_required
485 def new_serialno(self
):
486 """Return a unique new ID string suitable for use as a node's ID"""
487 env
= self
.state
.document
.settings
.env
488 return 'qapidoc-%d' % env
.new_serialno('qapidoc')
491 env
= self
.state
.document
.settings
.env
492 qapifile
= env
.config
.qapidoc_srctree
+ '/' + self
.arguments
[0]
493 qapidir
= os
.path
.dirname(qapifile
)
496 schema
= QAPISchema(qapifile
)
498 # First tell Sphinx about all the schema files that the
499 # output documentation depends on (including 'qapifile' itself)
500 schema
.visit(QAPISchemaGenDepVisitor(env
, qapidir
))
502 vis
= QAPISchemaGenRSTVisitor(self
)
503 vis
.visit_begin(schema
)
504 for doc
in schema
.docs
:
506 vis
.symbol(doc
, schema
.lookup_entity(doc
.symbol
))
509 return vis
.get_document_nodes()
510 except QAPIError
as err
:
511 # Launder QAPI parse errors into Sphinx extension errors
512 # so they are displayed nicely to the user
513 raise ExtensionError(str(err
))
515 def do_parse(self
, rstlist
, node
):
516 """Parse rST source lines and add them to the specified node
518 Take the list of rST source lines rstlist, parse them as
519 rST, and add the resulting docutils nodes as children of node.
520 The nodes are parsed in a way that allows them to include
521 subheadings (titles) without confusing the rendering of
524 # This is from kerneldoc.py -- it works around an API change in
525 # Sphinx between 1.6 and 1.7. Unlike kerneldoc.py, we use
526 # sphinx.util.nodes.nested_parse_with_titles() rather than the
527 # plain self.state.nested_parse(), and so we can drop the saving
528 # of title_styles and section_level that kerneldoc.py does,
529 # because nested_parse_with_titles() does that for us.
531 with
switch_source_input(self
.state
, rstlist
):
532 nested_parse_with_titles(self
.state
, rstlist
, node
)
534 save
= self
.state
.memo
.reporter
535 self
.state
.memo
.reporter
= AutodocReporter(
536 rstlist
, self
.state
.memo
.reporter
)
538 nested_parse_with_titles(self
.state
, rstlist
, node
)
540 self
.state
.memo
.reporter
= save
544 """ Register qapi-doc directive with Sphinx"""
545 app
.add_config_value('qapidoc_srctree', None, 'env')
546 app
.add_directive('qapi-doc', QAPIDocDirective
)
550 parallel_read_safe
=True,
551 parallel_write_safe
=True