From 03bf06bdc13c066a4703ab16e767dd91214969e3 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 6 Jun 2019 17:38:00 +0200 Subject: 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 Message-Id: <20190606153803.5278-5-armbru@redhat.com> Reviewed-by: Markus Armbruster Signed-off-by: Markus Armbruster --- scripts/qapi/common.py | 127 +++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 102 insertions(+), 25 deletions(-) diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py index 9e4b6c00b5..f40a2cd4c5 100644 --- a/scripts/qapi/common.py +++ b/scripts/qapi/common.py @@ -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, -- cgit v1.2.3