From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02847C433EF for ; Tue, 7 Sep 2021 10:46:46 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4E61760698 for ; Tue, 7 Sep 2021 10:46:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4E61760698 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:42232 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mNYcm-0008HZ-8F for qemu-devel@archiver.kernel.org; Tue, 07 Sep 2021 06:46:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47236) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mNYbG-000705-91 for qemu-devel@nongnu.org; Tue, 07 Sep 2021 06:45:13 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:58352) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mNYbC-0005Uz-0y for qemu-devel@nongnu.org; Tue, 07 Sep 2021 06:45:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631011504; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Zw66zTct1qzYq1oay75/NHyFTRFNO2YfUe/1e3jBuK8=; b=LTIZovNpdTXYTtyLWvTN7HeQlUfxmREzvRgxo/WxzHBAsojlxjWU6IwlQeNEqQzcIvNcen 51LQm3h1EuiJIfsMKlrHryLZ6xxKNQCNjfKPTbbHNrxNRZurhdUDw/PRNe/ORzL5iixs10 DXHKol9veEd+tJzlf/ngqGUV2ZEpX48= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-268-uzIoodEeNoK1w1q9lCM2nw-1; Tue, 07 Sep 2021 06:44:57 -0400 X-MC-Unique: uzIoodEeNoK1w1q9lCM2nw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C74201966329; Tue, 7 Sep 2021 10:44:56 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-112-13.ams2.redhat.com [10.36.112.13]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3A9246A255; Tue, 7 Sep 2021 10:44:56 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 9957E1138606; Tue, 7 Sep 2021 12:44:54 +0200 (CEST) From: Markus Armbruster To: John Snow Subject: Re: [PATCH v2 3/6] qapi/parser: add type hint annotations (QAPIDoc) References: <20210520225710.168356-1-jsnow@redhat.com> <20210520225710.168356-4-jsnow@redhat.com> Date: Tue, 07 Sep 2021 12:44:54 +0200 In-Reply-To: <20210520225710.168356-4-jsnow@redhat.com> (John Snow's message of "Thu, 20 May 2021 18:57:07 -0400") Message-ID: <87o8943brt.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -6 X-Spam_score: -0.7 X-Spam_bar: / X-Spam_report: (-0.7 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.391, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_DBL_SPAM=2.5 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Michael Roth , Cleber Rosa , qemu-devel@nongnu.org, Markus Armbruster , Eduardo Habkost Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" John Snow writes: > Annotations do not change runtime behavior. > > This commit adds mostly annotations, but uses a TYPE_CHECKING runtime > check to conditionally import dependencies, which only triggers during > runs of mypy. Please add a reference to https://mypy.readthedocs.io/en/latest/runtime_troubles.html#import-cycles > Signed-off-by: John Snow > > --- > > TopLevelExpr, an idea from previous drafts, makes a return here in order > to give a semantic meaning to check_expr(). The type is intended to be > used more in forthcoming commits (pt5c), but I opted to include it now > instead of creating yet-another Dict[str, object] type hint that I would > forget to change later. > > Signed-off-by: John Snow > --- > scripts/qapi/parser.py | 77 ++++++++++++++++++++++++++---------------- > 1 file changed, 48 insertions(+), 29 deletions(-) > > diff --git a/scripts/qapi/parser.py b/scripts/qapi/parser.py > index 3ddde318376..b1e2fa5c577 100644 > --- a/scripts/qapi/parser.py > +++ b/scripts/qapi/parser.py > @@ -18,6 +18,7 @@ > import os > import re > from typing import ( > + TYPE_CHECKING, > Dict, > List, > Optional, > @@ -30,6 +31,15 @@ > from .source import QAPISourceInfo > > > +if TYPE_CHECKING: > + # pylint: disable=cyclic-import > + # TODO: Remove cycle. [schema -> expr -> parser -> schema] > + from .schema import QAPISchemaFeature, QAPISchemaMember > + > + > +#: Represents a single Top Level QAPI schema expression. > +TopLevelExpr = Dict[str, object] Related: _ExprValue below, and _JSONObject in expr.py. The latter's comment gives the best rationale (except I don't get "the purpose of this module is to interrogate that type"). I think we'd like to have * A recursive type for JSON value (in our bastardized version of JSON) This is Union of bool, str, List[Self], Dict[str, Self]. It's what .get_expr() returns. Since mypy can't do recursive, we approximate with _ExprValue. * A recursive type for JSON object This is the Dict branch of the above. It's what check_keys() & friends take as argument. We approximate with _JSONObject. Same for the List branch would make sense if we had a use for the type. * A recursive type for TOP-LEVEL-EXPR Actually the same type as the previous one, to be used only for the schema's top-level expressions. It's the elements of QAPISchemaParser.exprs[], and what check_exprs() takes as argument. We approximate with TopLevelExpr, but so far use it only for check_exprs(). Doesn't really improve type checking, but may serve as documentation. Shouldn't these types be all defined in one place, namely right here? Bonus: we need to explain the mypy sadness just once then. Shouldn't their names be more systematic? _ExprValue, _JSONObject and TopLevelExpr hardly suggest any relation... > + > # Return value alias for get_expr(). > _ExprValue = Union[List[object], Dict[str, object], str, bool] > > @@ -447,7 +457,8 @@ class QAPIDoc: > """ > > class Section: > - def __init__(self, parser, name=None, indent=0): > + def __init__(self, parser: QAPISchemaParser, > + name: Optional[str] = None, indent: int = 0): > # parser, for error messages about indentation > self._parser = parser > # optional section name (argument/member or section name) > @@ -459,7 +470,7 @@ def __init__(self, parser, name=None, indent=0): > def __bool__(self) -> bool: > return bool(self.name or self.text) > > - def append(self, line): > + def append(self, line: str) -> None: > # Strip leading spaces corresponding to the expected indent level > # Blank lines are always OK. > if line: > @@ -474,39 +485,40 @@ def append(self, line): > self.text += line.rstrip() + '\n' > > class ArgSection(Section): > - def __init__(self, parser, name, indent=0): > + def __init__(self, parser: QAPISchemaParser, > + name: Optional[str] = None, indent: int = 0): Why not name: str? All callers pass a str argument... > super().__init__(parser, name, indent) > - self.member = None > + self.member: Optional['QAPISchemaMember'] = None I guess you need to quote 'QAPISchemaMember', because we actually import it only if TYPE_CHECKING. More of the same below. > > - def connect(self, member): > + def connect(self, member: 'QAPISchemaMember') -> None: > self.member = member > > - def __init__(self, parser, info): > + def __init__(self, parser: QAPISchemaParser, info: QAPISourceInfo): > # self._parser is used to report errors with QAPIParseError. The > # resulting error position depends on the state of the parser. > # It happens to be the beginning of the comment. More or less > # servicable, but action at a distance. > self._parser = parser > self.info = info > - self.symbol = None > + self.symbol: Optional[str] = None > self.body = QAPIDoc.Section(parser) > # dict mapping parameter name to ArgSection > - self.args = OrderedDict() > - self.features = OrderedDict() > + self.args: Dict[str, QAPIDoc.ArgSection] = OrderedDict() > + self.features: Dict[str, QAPIDoc.ArgSection] = OrderedDict() > # a list of Section > - self.sections = [] > + self.sections: List[QAPIDoc.Section] = [] > # the current section > self._section = self.body > self._append_line = self._append_body_line > > - def has_section(self, name): > + def has_section(self, name: str) -> bool: > """Return True if we have a section with this name.""" > for i in self.sections: > if i.name == name: > return True > return False > > - def append(self, line): > + def append(self, line: str) -> None: > """ > Parse a comment line and add it to the documentation. > > @@ -527,18 +539,18 @@ def append(self, line): > line = line[1:] > self._append_line(line) > > - def end_comment(self): > + def end_comment(self) -> None: > self._end_section() > > @staticmethod > - def _is_section_tag(name): > + def _is_section_tag(name: str) -> bool: > return name in ('Returns:', 'Since:', > # those are often singular or plural > 'Note:', 'Notes:', > 'Example:', 'Examples:', > 'TODO:') > > - def _append_body_line(self, line): > + def _append_body_line(self, line: str) -> None: > """ > Process a line of documentation text in the body section. > > @@ -578,7 +590,7 @@ def _append_body_line(self, line): > # This is a free-form documentation block > self._append_freeform(line) > > - def _append_args_line(self, line): > + def _append_args_line(self, line: str) -> None: > """ > Process a line of documentation text in an argument section. > > @@ -624,7 +636,7 @@ def _append_args_line(self, line): > > self._append_freeform(line) > > - def _append_features_line(self, line): > + def _append_features_line(self, line: str) -> None: > name = line.split(' ', 1)[0] > > if name.startswith('@') and name.endswith(':'): > @@ -656,7 +668,7 @@ def _append_features_line(self, line): > > self._append_freeform(line) > > - def _append_various_line(self, line): > + def _append_various_line(self, line: str) -> None: > """ > Process a line of documentation text in an additional section. > > @@ -692,7 +704,11 @@ def _append_various_line(self, line): > > self._append_freeform(line) > > - def _start_symbol_section(self, symbols_dict, name, indent): > + def _start_symbol_section( > + self, > + symbols_dict: Dict[str, 'QAPIDoc.ArgSection'], The need to quote this within the very class that defines it is annoying. > + name: str, > + indent: int) -> None: > # FIXME invalid names other than the empty string aren't flagged > if not name: > raise QAPIParseError(self._parser, "invalid parameter name") > @@ -704,13 +720,14 @@ def _start_symbol_section(self, symbols_dict, name, indent): > self._section = QAPIDoc.ArgSection(self._parser, name, indent) > symbols_dict[name] = self._section > > - def _start_args_section(self, name, indent): > + def _start_args_section(self, name: str, indent: int) -> None: > self._start_symbol_section(self.args, name, indent) > > - def _start_features_section(self, name, indent): > + def _start_features_section(self, name: str, indent: int) -> None: > self._start_symbol_section(self.features, name, indent) > > - def _start_section(self, name=None, indent=0): > + def _start_section(self, name: Optional[str] = None, > + indent: int = 0) -> None: > if name in ('Returns', 'Since') and self.has_section(name): > raise QAPIParseError(self._parser, > "duplicated '%s' section" % name) > @@ -718,7 +735,7 @@ def _start_section(self, name=None, indent=0): > self._section = QAPIDoc.Section(self._parser, name, indent) > self.sections.append(self._section) > > - def _end_section(self): > + def _end_section(self) -> None: > if self._section: > text = self._section.text = self._section.text.strip() > if self._section.name and (not text or text.isspace()): > @@ -727,7 +744,7 @@ def _end_section(self): > "empty doc section '%s'" % self._section.name) > self._section = QAPIDoc.Section(self._parser) > > - def _append_freeform(self, line): > + def _append_freeform(self, line: str) -> None: > match = re.match(r'(@\S+:)', line) > if match: > raise QAPIParseError(self._parser, > @@ -735,28 +752,30 @@ def _append_freeform(self, line): > % match.group(1)) > self._section.append(line) > > - def connect_member(self, member): > + def connect_member(self, member: 'QAPISchemaMember') -> None: > if member.name not in self.args: > # Undocumented TODO outlaw > self.args[member.name] = QAPIDoc.ArgSection(self._parser, > member.name) > self.args[member.name].connect(member) > > - def connect_feature(self, feature): > + def connect_feature(self, feature: 'QAPISchemaFeature') -> None: > if feature.name not in self.features: > raise QAPISemError(feature.info, > "feature '%s' lacks documentation" > % feature.name) > self.features[feature.name].connect(feature) > > - def check_expr(self, expr): > + def check_expr(self, expr: TopLevelExpr) -> None: > if self.has_section('Returns') and 'command' not in expr: > raise QAPISemError(self.info, > "'Returns:' is only valid for commands") > > - def check(self): > + def check(self) -> None: > > - def check_args_section(args, what): > + def check_args_section( > + args: Dict[str, QAPIDoc.ArgSection], what: str > + ) -> None: This is the fourth use of Dict[str, QAPIDoc.ArgSection]. Still fine, but if we acquire even more, we should consider giving it a name. > bogus = [name for name, section in args.items() > if not section.member] > if bogus: