qapi: Disentangle QAPIDoc code

Documentation comments follow a certain structure: First, we have a text
with a general description (called QAPIDoc.body). After this,
descriptions of the arguments follow. Finally, we have a part that
contains various named sections.

The code doesn't show this structure, but just checks various attributes
that indicate indirectly which part is being processed, so it happens to
do the right set of things in the right phase. This is hard to follow,
and adding support for documentation of features would be even harder.

This patch restructures the code so that the three parts are clearly
separated. The code becomes a bit longer, but easier to follow. The
resulting output remains unchanged.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190606153803.5278-5-armbru@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This commit is contained in:
Kevin Wolf 2019-06-06 17:38:00 +02:00 committed by Markus Armbruster
parent a00af40425
commit 03bf06bdc1

View file

@ -120,6 +120,24 @@ class QAPIDoc(object):
def connect(self, member):
self.member = member
class DocPart:
"""
Describes which part of the documentation we're parsing right now.
Expression documentation blocks consist of
* a BODY part: first line naming the expression, plus an
optional overview
* an ARGS part: description of each argument (for commands and
events) or member (for structs, unions and alternates),
* a VARIOUS part: optional tagged sections.
Free-form documentation blocks consist only of a BODY part.
"""
# TODO Make it a subclass of Enum when Python 2 support is removed
BODY = 1
ARGS = 2
VARIOUS = 3
def __init__(self, parser, info):
# self._parser is used to report errors with QAPIParseError. The
# resulting error position depends on the state of the parser.
@ -135,6 +153,7 @@ class QAPIDoc(object):
self.sections = []
# the current section
self._section = self.body
self._part = QAPIDoc.DocPart.BODY
def has_section(self, name):
"""Return True if we have a section with this name."""
@ -144,7 +163,27 @@ class QAPIDoc(object):
return False
def append(self, line):
"""Parse a comment line and add it to the documentation."""
"""
Parse a comment line and add it to the documentation.
The way that the line is dealt with depends on which part of
the documentation we're parsing right now:
BODY means that we're ready to process free-form text into
self.body. A symbol name is only allowed if no other text was
parsed yet. It is interpreted as the symbol name that
describes the currently documented object. On getting the
second symbol name, we proceed to ARGS.
ARGS means that we're parsing the arguments section. Any
symbol name is interpreted as an argument and an ArgSection is
created for it.
VARIOUS is the final part where free-form sections may appear.
This includes named sections such as "Return:" as well as
unnamed paragraphs. Symbols are not allowed any more in this
part.
"""
line = line[1:]
if not line:
self._append_freeform(line)
@ -154,37 +193,85 @@ class QAPIDoc(object):
raise QAPIParseError(self._parser, "Missing space after #")
line = line[1:]
if self._part == QAPIDoc.DocPart.BODY:
self._append_body_line(line)
elif self._part == QAPIDoc.DocPart.ARGS:
self._append_args_line(line)
elif self._part == QAPIDoc.DocPart.VARIOUS:
self._append_various_line(line)
else:
assert False
def end_comment(self):
self._end_section()
@staticmethod
def _is_section_tag(name):
return name in ('Returns:', 'Since:',
# those are often singular or plural
'Note:', 'Notes:',
'Example:', 'Examples:',
'TODO:')
def _append_body_line(self, line):
name = line.split(' ', 1)[0]
# FIXME not nice: things like '# @foo:' and '# @foo: ' aren't
# recognized, and get silently treated as ordinary text
if self.symbol:
self._append_symbol_line(line)
elif not self.body.text and line.startswith('@'):
if not self.symbol and not self.body.text and line.startswith('@'):
if not line.endswith(':'):
raise QAPIParseError(self._parser, "Line should end with :")
self.symbol = line[1:-1]
# FIXME invalid names other than the empty string aren't flagged
if not self.symbol:
raise QAPIParseError(self._parser, "Invalid name")
elif self.symbol:
# We already know that we document some symbol
if name.startswith('@') and name.endswith(':'):
self._part = QAPIDoc.DocPart.ARGS
self._append_args_line(line)
elif self._is_section_tag(name):
self._part = QAPIDoc.DocPart.VARIOUS
self._append_various_line(line)
else:
self._append_freeform(line.strip())
else:
self._append_freeform(line)
# This is free-form documentation without a symbol
self._append_freeform(line.strip())
def end_comment(self):
self._end_section()
def _append_symbol_line(self, line):
def _append_args_line(self, line):
name = line.split(' ', 1)[0]
if name.startswith('@') and name.endswith(':'):
line = line[len(name)+1:]
self._start_args_section(name[1:-1])
elif name in ('Returns:', 'Since:',
# those are often singular or plural
'Note:', 'Notes:',
'Example:', 'Examples:',
'TODO:'):
elif self._is_section_tag(name):
self._part = QAPIDoc.DocPart.VARIOUS
self._append_various_line(line)
return
elif (self._section.text.endswith('\n\n')
and line and not line[0].isspace()):
self._start_section()
self._part = QAPIDoc.DocPart.VARIOUS
self._append_various_line(line)
return
self._append_freeform(line.strip())
def _append_various_line(self, line):
name = line.split(' ', 1)[0]
if name.startswith('@') and name.endswith(':'):
raise QAPIParseError(self._parser,
"'%s' can't follow '%s' section"
% (name, self.sections[0].name))
elif self._is_section_tag(name):
line = line[len(name)+1:]
self._start_section(name[:-1])
if (not self._section.name or
not self._section.name.startswith('Example')):
line = line.strip()
self._append_freeform(line)
def _start_args_section(self, name):
@ -194,10 +281,7 @@ class QAPIDoc(object):
if name in self.args:
raise QAPIParseError(self._parser,
"'%s' parameter name duplicated" % name)
if self.sections:
raise QAPIParseError(self._parser,
"'@%s:' can't follow '%s' section"
% (name, self.sections[0].name))
assert not self.sections
self._end_section()
self._section = QAPIDoc.ArgSection(name)
self.args[name] = self._section
@ -219,13 +303,6 @@ class QAPIDoc(object):
self._section = None
def _append_freeform(self, line):
in_arg = isinstance(self._section, QAPIDoc.ArgSection)
if (in_arg and self._section.text.endswith('\n\n')
and line and not line[0].isspace()):
self._start_section()
if (in_arg or not self._section.name
or not self._section.name.startswith('Example')):
line = line.strip()
match = re.match(r'(@\S+:)', line)
if match:
raise QAPIParseError(self._parser,